rt Inhibitory Actions of Potentiating Neuroactive Steroids in the Human {alpha}1{beta}3{gamma}2L {gamma}-Aminobutyric Acid Type A Receptor [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 The -aminobutyric acid type A (GABAA) receptor is modulated by a number of neuroactive steroids. Sulfated steroids and 3β-hydroxy steroids inhibit, while 3α-hydroxy steroids typically potentiate the receptor. Here, we have investigated inhibition of the α1β32L GABAA receptor by the endogenous neurosteroid 3α-hydroxy-5β-pregnan-20-one (3α5βP) and the synthetic neuroactive steroid 3α-hydroxy-5α-androstane-17β-carbonitrile (ACN). The receptors were expressed in Xenopus oocytes. All experiments were done using two-electrode voltage-clamp electrophysiology. In the presence of low concentrations of GABA, 3α5βP and ACN potentiate the GABAA receptor. To reveal inhibition, we conducted the experiments on receptors activated by the combination of a saturating concentration of GABA and propofol to fully activate the receptors and mask potentiation, or on mutant receptors in which potentiation is ablated. Under these conditions, both steroids inhibited the receptor with IC50s of ~13 μM and maximal inhibitory effects of 70–90%. Receptor inhibition by 3α5βP was sensitive to substitution of the α1 transmembrane domain (TM) 2-2' residue, previously shown to ablate inhibition by pregnenolone sulfate. However, results of coapplication studies and the apparent lack of state dependence suggest that pregnenolone sulfate and 3α5βP inhibit the GABAA receptor independently and through distinct mechanisms. Mutations to the neurosteroid binding sites in the α1 and β3 subunits statistically significantly, albeit weakly and incompletely, reduced inhibition by 3α5βP and ACN. SIGNIFICANCE STATEMENT The heteromeric GABAA receptor is inhibited by sulfated steroids and 3β-hydroxy steroids, while 3α-hydroxy steroids are considered to potentiate the receptor. We show here that 3α-hydroxy steroids have inhibitory effects on the α1β32L receptor, which are observed in specific experimental settings and are expected to manifest under different physiological conditions. Full Article
rt Ghrelin Modulates Voltage-Gated Ca2+ Channels through Voltage-Dependent and Voltage-Independent Pathways in Rat Gastric Vagal Afferent Neurons [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 The orexigenic gut peptide ghrelin is an endogenous ligand for the growth hormone secretagogue receptor type 1a (GHSR1a). Systemic ghrelin administration has previously been shown to increase gastric motility and emptying. While these effects are known to be mediated by the vagus nerve, the cellular mechanism underlying these effects remains unclear. Therefore, the purpose of the present study was to investigate the signaling mechanism by which GHSR1a inhibits voltage-gated Ca2+ channels in isolated rat gastric vagal afferent neurons using whole-cell patch-clamp electrophysiology. The ghrelin pharmacological profile indicated that Ca2+ currents were inhibited with a log (Ic50) = –2.10 ± 0.44 and a maximal inhibition of 42.8 ± 5.0%. Exposure to the GHSR1a receptor antagonist (D-Lys3)-GHRP-6 reduced ghrelin-mediated Ca2+ channel inhibition (29.4 ± 16.7% vs. 1.9 ± 2.5%, n = 6, P = 0.0064). Interestingly, we observed that activation of GHSR1a inhibited Ca2+ currents through both voltage-dependent and voltage-independent pathways. We also treated the gastric neurons with either pertussis toxin (PTX) or YM-254890 to examine whether the Ca2+ current inhibition was mediated by the Gαi/o or Gαq/11 family of subunits. Treatment with both PTX (Ca2+ current inhibition = 15.7 ± 10.6%, n = 8, P = 0.0327) and YM-254890 (15.2 ± 11.9%, n = 8, P = 0.0269) blocked ghrelin’s effects on Ca2+ currents, as compared with control neurons (34.3 ± 18.9%, n = 8). These results indicate GHSR1a can couple to both Gαi/o and Gαq/11 in gastric vagal afferent neurons. Overall, our findings suggest GHSR1a-mediated inhibition of Ca2+ currents occurs through two distinct pathways, offering necessary insights into the cellular mechanisms underlying ghrelin’s regulation of gastric vagal afferents. SIGNIFICANCE STATEMENT This study demonstrated that in gastric vagal afferent neurons, activation of GHSR1a by ghrelin inhibits voltage-gated Ca2+ channels through both voltage-dependent and voltage-independent signaling pathways. These results provide necessary insights into the cellular mechanism underlying ghrelin regulation of gastric vagal afferent activity, which may benefit future studies investigating ghrelin mimetics to treat gastric motility disorders. Full Article
rt Ketamine and Major Ketamine Metabolites Function as Allosteric Modulators of Opioid Receptors [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 Ketamine is a glutamate receptor antagonist that was developed over 50 years ago as an anesthetic agent. At subanesthetic doses, ketamine and some metabolites are analgesics and fast-acting antidepressants, presumably through targets other than glutamate receptors. We tested ketamine and its metabolites for activity as allosteric modulators of opioid receptors expressed as recombinant receptors in heterologous systems and with native receptors in rodent brain; signaling was examined by measuring GTP binding, β-arrestin recruitment, MAPK activation, and neurotransmitter release. Although micromolar concentrations of ketamine alone had weak agonist activity at μ opioid receptors, the combination of submicromolar concentrations of ketamine with endogenous opioid peptides produced robust synergistic responses with statistically significant increases in efficacies. All three opioid receptors (μ, , and ) showed synergism with submicromolar concentrations of ketamine and either methionine-enkephalin (Met-enk), leucine-enkephalin (Leu-enk), and/or dynorphin A17 (Dyn A17), albeit the extent of synergy was variable between receptors and peptides. S-ketamine exhibited higher modulatory effects compared with R-ketamine or racemic ketamine, with ~100% increase in efficacy. Importantly, the ketamine metabolite 6-hydroxynorketamine showed robust allosteric modulatory activity at μ opioid receptors; this metabolite is known to have analgesic and antidepressant activity but does not bind to glutamate receptors. Ketamine enhanced potency and efficacy of Met-enkephalin signaling both in mouse midbrain membranes and in rat ventral tegmental area neurons as determined by electrophysiology recordings in brain slices. Taken together, these findings support the hypothesis that some of the therapeutic effects of ketamine and its metabolites are mediated by directly engaging the endogenous opioid system. SIGNIFICANCE STATEMENT This study found that ketamine and its major biologically active metabolites function as potent allosteric modulators of μ, , and opioid receptors, with submicromolar concentrations of these compounds synergizing with endogenous opioid peptides, such as enkephalin and dynorphin. This allosteric activity may contribute to ketamine’s therapeutic effectiveness for treating acute and chronic pain and as a fast-acting antidepressant drug. Full Article
rt Simplified Method for Kinetic and Thermodynamic Screening of Cardiotonic Steroids through the K+-Dependent Phosphatase Activity of Na+/K+-ATPase with Chromogenic pNPP Substrate [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 The antitumor effect of cardiotonic steroids (CTS) has stimulated the search for new methods to evaluate both kinetic and thermodynamic aspects of their binding to Na+/K+-ATPase (IUBMB Enzyme Nomenclature). We propose a real-time assay based on a chromogenic substrate for phosphatase activity (pNPPase activity), using only two concentrations with an inhibitory progression curve, to obtain the association rate (kon), dissociation rate (koff), and equilibrium (Ki) constants of CTS for the structure-kinetics relationship in drug screening. We show that changing conditions (from ATPase to pNPPase activity) resulted in an increase of Ki of the cardenolides digitoxigenin, essentially due to a reduction of kon. In contrast, the Ki of the structurally related bufadienolide bufalin increased much less due to the reduction of its koff partially compensating the decrease of its kon. When evaluating the kinetics of 15 natural and semisynthetic CTS, we observed that both kon and koff correlated with Ki (Spearman test), suggesting that differences in potency depend on variations of both kon and koff. A rhamnose in C3 of the steroidal nucleus enhanced the inhibitory potency by a reduction of koff rather than an increase of kon. Raising the temperature did not alter the koff of digitoxin, generating a H (koff) of –10.4 ± 4.3 kJ/mol, suggesting a complex dissociation mechanism. Based on a simple and inexpensive methodology, we determined the values of kon, koff, and Ki of the CTS and provided original kinetics and thermodynamics differences between CTS that could help the design of new compounds. SIGNIFICANCE STATEMENT This study describes a fast, simple, and cost-effective method for the measurement of phosphatase pNPPase activity enabling structure-kinetics relationships of Na+/K+-ATPase inhibitors, which are important compounds due to their antitumor effect and endogenous role. Using 15 compounds, some of them original, this study was able to delineate the kinetics and/or thermodynamics differences due to the type of sugar and lactone ring present in the steroid structure. Full Article
rt Arachidonic Acid Directly Activates the Human DP2 Receptor [Article] By molpharm.aspetjournals.org Published On :: 2024-10-17T05:12:59-07:00 Aberrant type 2 inflammatory responses are the underlying cause of the pathophysiology of allergic asthma, allergic rhinitis, and other atopic diseases, with an alarming prevalence in relevant parts of the Western world. A bulk of evidence points out the important role of the DP2 receptor in these inflammation processes. A screening of different polyunsaturated fatty acids at a fluorescence resonance energy transfer–based DP2 receptor conformation sensor expressed in human embryonic kidney (HEK) cells revealed an agonistic effect of the prostaglandin (PG)-D2 precursor arachidonic acid on DP2 receptor activity of about 80% of the effect induced by PGD2. In a combination of experiments at the conformation sensor and using a bioluminescence resonance energy transfer–based G protein activation sensor expressed together with DP2 receptor wild type in HEK cells, we found that arachidonic acid acts as a direct activator of the DP2 receptor, but not the DP1 receptor, in a concentration range considered physiologically relevant. Pharmacological inhibition of cyclooxygenases and lipoxygenases as well as cytochrome P450 did not lead to a diminished arachidonic acid response on the DP2 receptor, confirming a direct action of arachidonic acid on the receptor. SIGNIFICANCE STATEMENT This study identified the prostaglandin precursor arachidonic acid to directly activate the DP2 receptor, a G protein–coupled receptor that is known to play an important role in type 2 inflammation. Full Article
rt “Je suis desole, ȷe parle francais”: How English Hegemony Undermines Efforts to Shift Power in Global Health By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 Le texte complet de l’article est aussi disponible en français. Full Article
rt Establishment of the First Institution-Based Poison Information Center in Nepal Through a Multilateral International Partnership By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTToxicological emergencies present a significant health challenge in Nepal. Despite the high burden, the country has inadequate formal toxicology training, medical toxicology expertise, and adequate poison control infrastructure. In recognition of this need, the Nepal Poison Information Center (PIC) was established as a collaborative effort involving local and international partners. Through a comprehensive partnership framework, the Nepal PIC provides 24 hours a day, 7 days a week expert guidance to health care workers, conducts educational webinars, and engages in research. Initial data from the pilot phase indicate successful consultation delivery. Challenges include bureaucratic hurdles and the need for sustainable funding. Despite these challenges, the Nepal PIC demonstrates early feasibility and potential for expansion into a comprehensive toxicology center, contributing to the advancement of clinical toxicology in Nepal. Long-term sustainability relies on governmental support and continued advocacy efforts. Full Article
rt Early Lessons From Working With Local Partners to Expand Private-Sector Health Care Networks in Burundi and Mali By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTThe private health care sector is an important source of service delivery in low- and middle-income countries (LMICs). Yet, the private sector remains fragmented, making it difficult for health system actors to support and ensure the availability of quality health care services. In global health programs, social franchising is one model used to engage and organize the private health care sector. Two social franchise networks, ProFam in West Africa and Tunza in East and Central Africa, provide health care through branded networks of facilities. However, these social franchise networks include a limited number of private health care facilities, and in fragile contexts, like Burundi and Mali, they have faced challenges in integrating with national health systems. The MOMENTUM Private Healthcare Delivery (MPHD) project in Burundi and Mali sought to expand the number of health facilities it engaged beyond the existing ProFam and Tunza networks. The expansion aimed to help improve service quality in more private facilities while advancing localization and reducing fragmentation for improved stewardship by health system actors. MPHD achieved this expansion by removing barriers for private health facilities to join inclusive, nonbranded networks and engaging local partners to build and maintain these networks. We share lessons learned regarding the growing role of local organizations as actors within mixed health systems and provide insights on strengthening stewardship of the increasingly heterogeneous private health care delivery sector in LMICs, particularly in fragile settings. Full Article
rt Antenatal Care Interventions to Increase Contraceptive Use Following Birth in Low- and Middle-Income Countries: Systematic Review and Narrative Synthesis By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTIntroduction:Health risks associated with short interpregnancy intervals, coupled with women’s desires to avoid pregnancy following childbirth, underscore the need for effective postpartum family planning programs. The antenatal period provides an opportunity to intervene; however, evidence is limited on the effectiveness of interventions aimed at reaching women in the antenatal period to increase voluntary postpartum family planning in low- and middle-income countries (LMICs). This systematic review aimed to identify and describe interventions in LMICs that attempted to increase postpartum contraceptive use via contacts with pregnant women in the antenatal period.Methods:Studies published from January 2012 to July 2022 were considered if they were conducted in LMICs, evaluated an intervention delivered during the antenatal period, were designed to affect postpartum contraceptive use, were experimental or quasi-experimental, and were published in French or English. The main outcome of interest was postpartum contraceptive use within 1 year after birth, defined as the use of any method of contraception at the time of data collection. We searched EMBASE, Global Health, and Medline and manually searched the reference lists from studies included in the full-text screening.Results:We double-screened 771 records and included 34 reports on 31 unique interventions in the review. Twenty-three studies were published from 2018 on, with 21 studies conducted in sub-Saharan Africa. Approximately half of the study designs (n=16) were randomized controlled trials, and half (n=15) were quasi-experimental. Interventions were heterogeneous. Among the 24 studies that reported on the main outcome of interest, 18 reported a positive intervention effect, with intervention recipients having greater contraceptive use in the first year postpartum.Conclusion:While the studies in this systematic review were heterogeneous, the findings suggest that interventions that included a multifaceted package of initiatives appeared to be most likely to have a positive effect. Full Article
rt Improving Maternity Care Where Home Births Are Still the Norm: Establishing Local Birthing Centers in Guatemala That Incorporate Traditional Midwives By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTMore than half of births among Indigenous women in Guatemala are still being attended at home by providers with no formal training. We describe the incorporation of comadronas (traditional midwives) into casas maternas (birthing centers) in the rural highlands of western Guatemala. Although there was initial resistance to the casa, comadronas and clients have become increasingly enthusiastic about them. The casas provide the opportunity for comadronas to continue the cultural traditions of prayers, massages, and other practices that honor the vital spiritual dimension of childbirth close to home in a home-like environment with extended family support while at the same time providing a safer childbirth experience in which complications can be detected by trained personnel at the casa, managed locally, or promptly referred to a higher-level facility. Given the growing acceptance of this innovation in an environment in which geographical, financial, and cultural barriers to deliveries at higher-level facilities lead most women to deliver at home, casas maternas represent a feasible option for reducing the high level of maternal mortality in Guatemala.This article provides an update on the growing utilization of casas and provides new insights into the role of comadronas as birthing team members and enthusiastic promotors of casas maternas as a preferable alternative to home births. Through the end of 2023, these casas maternas had cared for 4,322 women giving birth. No maternal deaths occurred at a casa, but 4 died after referral.The Ministry of Health of Guatemala has recently adopted this approach and has begun to implement it in other rural areas where home births still predominate. This approach deserves consideration as a viable and feasible option for reducing maternal mortality throughout the world where home births are still common, while at the same time providing women with respectful and culturally appropriate care. Full Article
rt A Cosmopolitan Argument for Temporary “Diagonal” Short-Term Surgical Missions as a Component of Surgical Systems Strengthening By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 Full Article
rt Innovations in Providing HIV Index Testing Services: A Retrospective Evaluation of Partner Elicitation Models in Southern Nigeria By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTBackground: This analysis aimed to evaluate the effectiveness of eliciting sexual partners from HIV-positive clients using the elicitation box model (where an HIV-positive index can report sexual contacts on paper and insert in a box for a health care provider to contact at a later time) compared to the conventional model (in which a health care provider elicits sexual contacts directly from clients) in Akwa Ibom, Southern Nigeria.Methods: Between March 2021 and April 2022, data were collected from index testing registers at 4 health facilities with a high volume of HIV clients currently on treatment in 4 local government areas in Akwa Ibom State. Primary outcome analyzed was the elicitation ratio (number of partners elicited per HIV-index offered index testing services). Secondary outcomes were the index testing acceptance (index HIV-positive clients accepted index testing service), testing coverage (partners tested for HIV from a list of partners elicited from HIV-index accepted index testing services), testing yield (index partners identified HIV positive from index partners HIV-tested), and linkage rate (index partners identified HIV positive and linked to antiretroviral therapy).Results: Of the total 2,705 index clients offered index testing services, 91.9% accepted, with 2,043 and 439 indexes opting for conventional elicitation and elicitation box models, respectively. A total of 3,796 sexual contacts were elicited: 2,546 using the conventional model (elicitation ratio=1:1) and 1,250 using the elicitation box model (elicitation ratio=1:3). Testing coverage was significantly higher in the conventional compared to the elicitation box model (P<.001). However, there was no significant difference in the testing yield (P=.81) and linkage rate using the conventional compared to elicitation box models (P=.13).Conclusion: The implementation of the elicitation box model resulted in an increase in partner elicitation compared to the conventional model. Increasing the testing coverage by implementing the elicitation box model should be considered. Full Article
rt Development and Piloting of Implementation Strategies to Support Delivery of a Clinical Intervention for Postpartum Hemorrhage in Four sub-Saharan Africa Countries By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTIntroduction:Postpartum hemorrhage (PPH) remains the leading cause of maternal mortality. A new clinical intervention (E-MOTIVE) holds the potential to improve early PPH detection and management. We aimed to develop and pilot implementation strategies to support uptake of this intervention in Kenya, Nigeria, South Africa, and Tanzania.Methods:Implementation strategy development: We triangulated findings from qualitative interviews, surveys and a qualitative evidence synthesis to identify current PPH care practices and influences on future intervention implementation. We mapped influences using implementation science frameworks to identify candidate implementation strategies before presenting these at stakeholder consultation and design workshops to discuss feasibility, acceptability, and local adaptations. Piloting: The intervention and implementation strategies were piloted in 12 health facilities (3 per country) over 3 months. Interviews (n=58), case report forms (n=1,269), and direct observations (18 vaginal births, 7 PPHs) were used to assess feasibility, acceptability, and fidelity.Results:Implementation strategy development: Key influences included shortages of drugs, supplies, and staff, limited in-service training, and perceived benefits of the intervention (e.g., more accurate PPH detection and reduced PPH mortality). Proposed implementation strategies included a PPH trolley, on-site simulation-based training, champions, and audit and feedback. Country-specific adaptations included merging the E-MOTIVE intervention with national maternal health trainings, adapting local PPH protocols, and PPH trollies depending on staff needs. Piloting: Intervention and implementation strategy fidelity differed within and across countries. Calibrated drapes resulted in earlier and more accurate PPH detection but were not consistently used at the start. Implementation strategies were feasible to deliver; however, some instances of limited use were observed (e.g., PPH trolley and skills practice after training).Conclusion:Systematic intervention development, piloting, and process evaluation helped identify initial challenges related to intervention fidelity, which were addressed ahead of a larger-scale effectiveness evaluation. This has helped maximize the internal validity of the trial. Full Article
rt Twinning Partnership Network: A Learning and Experience-Sharing Network Among Health Professionals in Rwanda to Improve Health Services By ghspjournal.org Published On :: 2024-10-29T12:28:39-07:00 ABSTRACTWe describe the development, implementation, and evaluation of a novel twinning approach: the Twinning Partnership Network (TPN). Twinning is a well-known approach to peer learning that has been used in a variety of settings to build organizational capacity. Although twinning takes many forms, the heart of the approach is that institutions with shared characteristics collaborate via sharing information and experiences to achieve a specific goal. We adapted a twinning partnership strategy developed by the World Health Organization to create a network of like-minded health institutions. The key innovation of the TPN is the network, which ensures that an institution always has a high-performing peer with whom to partner on a specific topic area of interest. We identified 10 hospitals and 30 districts in Rwanda to participate in the TPN. These districts and hospitals participated in a kickoff workshop in which they identified capacity gaps, clarified goals, and selected twinning partners. After the workshop, districts and hospitals participated in exchange visits, coaching visits, and virtual and in-person learning events. We found that districts and hospitals that selected specific areas and worked on them throughout the duration of the TPN with their peers improved their performance significantly when compared with those that selected and worked on other areas. Accreditation scores improved by 5.6% more in hospitals selecting accreditation than those that did not. Districts that selected improving community-based health insurance coverage improved by 4.8% more than districts that did not select this topic area. We hypothesize that these results are due to senior management’s interest and motivation to improve in these specific areas, the motivation gained by learning from high-performing peers with similar resources, and context-specific knowledge sharing from peer hospitals and districts. Full Article
rt Factors Influencing the Central Nervous System (CNS) Distribution of the Ataxia Telangiectasia Mutated and Rad3-Related Inhibitor Elimusertib (BAY1895344): Implications for the Treatment of CNS Tumors [Metabolism, Transport, and Pharmacogenetics] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Glioblastoma (GBM) is a disease of the whole brain, with infiltrative tumor cells protected by an intact blood-brain barrier (BBB). GBM has a poor prognosis despite aggressive treatment, in part due to the lack of adequate drug permeability at the BBB. Standard of care GBM therapies include radiation and cytotoxic chemotherapy that lead to DNA damage. Subsequent activation of DNA damage response (DDR) pathways can induce resistance. Various DDR inhibitors, targeting the key regulators of these pathways such as ataxia telangiectasia mutated and Rad3-related (ATR), are being explored as radio- and chemosensitizers. Elimusertib, a novel ATR kinase inhibitor, can prevent repair of damaged DNA, increasing efficacy of DNA-damaging cytotoxic therapies. Robust synergy was observed in vitro when elimusertib was combined with the DNA-damaging agent temozolomide; however, we did not observe improvement with this combination in in vivo efficacy studies in GBM orthotopic tumor-bearing mice. This in vitro–in vivo disconnect was explored to understand factors influencing central nervous system (CNS) distribution of elimusertib and reasons for lack of efficacy. We observed that elimusertib is rapidly cleared from systemic circulation in mice and would not maintain adequate exposure in the CNS for efficacious combination therapy with temozolomide. CNS distribution of elimusertib is partially limited by P-glycoprotein efflux at the BBB, and high binding to CNS tissues leads to low levels of pharmacologically active (unbound) drug in the brain. Acknowledging the potential for interspecies differences in pharmacokinetics, these data suggest that clinical translation of elimusertib in combination with temozolomide for treatment of GBM may be limited. SIGNIFICANCE STATEMENT This study examined the disconnect between the in vitro synergy and in vivo efficacy of elimusertib/temozolomide combination therapy by exploring systemic and central nervous system (CNS) distributional pharmacokinetics. Results indicate that the lack of improvement in in vivo efficacy in glioblastoma (GBM) patient-derived xenograft (PDX) models could be attributed to inadequate exposure of pharmacologically active drug concentrations in the CNS. These observations can guide further exploration of elimusertib for the treatment of GBM or other CNS tumors. Full Article
rt Nonclinical Profile of PF-06952229 (MDV6058), a Novel TGF{beta}RI/Activin Like Kinase 5 Inhibitor Supports Clinical Evaluation in Cancer [Drug Discovery and Translational Medicine] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 The development of transforming growth factor βreceptor inhibitors (TGFβRi) as new medicines has been affected by cardiac valvulopathy and arteriopathy toxicity findings in nonclinical toxicology studies. PF-06952229 (MDV6058) selected using rational drug design is a potent and selective TGFβRI inhibitor with a relatively clean off-target selectivity profile and good pharmacokinetic properties across species. PF-06952229 inhibited clinically translatable phospho-SMAD2 biomarker (≥60%) in human and cynomolgus monkey peripheral blood mononuclear cells, as well as in mouse and rat splenocytes. Using an optimized, intermittent dosing schedule (7-day on/7-day off/cycle; 5 cycles), PF-06952229 demonstrated efficacy in a 63-day syngeneic MC38 colon carcinoma mouse model. In the pivotal repeat-dose toxicity studies (rat and cynomolgus monkey), PF-06952229 on an intermittent dosing schedule (5-day on/5-day off cycle; 5 cycles, 28 doses) showed no cardiac-related adverse findings. However, new toxicity findings related to PF-06952229 included reversible hepatocellular (hepatocyte necrosis with corresponding clinically monitorable transaminase increases) and lung (hemorrhage with mixed cell inflammation) findings at ≥ targeted projected clinical efficacious exposures. Furthermore, partially reversible cartilage hypertrophy (trachea and femur in rat; femur in monkey) and partially to fully reversible, clinically monitorable decreases in serum phosphorus and urinary phosphate at ≥ projected clinically efficacious exposures were observed. Given the integral role of TGFβ in endochondral bone formation, cartilage findings in toxicity studies have been observed with other TGFβRi classes of compounds. The favorable cumulative profile of PF-06952229 in biochemical, pharmacodynamic, pharmacokinetic, and nonclinical studies allowed for its evaluation in cancer patients using the intermittent dosing schedule (7-day on/7-day off) and careful protocol-defined monitoring. SIGNIFICANCE STATEMENT Only a few TGFβRi have progressed for clinical evaluation due to adverse cardiac findings in pivotal nonclinical toxicity studies. The potential translations of such findings in patients are of major concern. Using a carefully optimized intermittent dosing schedule, PF-06952229 has demonstrated impressive pharmacological efficacy in the syngeneic MC38 colon carcinoma mouse model. Additionally, a nonclinical toxicology package without cardiovascular liabilities and generally monitorable toxicity profile has been completed. The compound presents an acceptable International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use S9-compliant profile for the intended-to-treat cancer patients. Full Article
rt Effects of Dual Inhibition at Dopamine Transporter and {sigma} Receptors in the Discriminative-Stimulus Effects of Cocaine in Male Rats [Behavioral Pharmacology] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Previous studies demonstrated that sigma receptor (R) antagonists alone fail to alter cocaine self-administration despite blocking various other effects of cocaine. However, R antagonists when combined with dopamine transporter (DAT) inhibitors substantially decrease cocaine self-administration. To better understand the effects of this combination, the present study examined the effects of R antagonist and DAT inhibitor combinations in male rats discriminating cocaine (10 mg/kg, i.p.) from saline injections. The DAT inhibitors alone [(–)-2-β-carbomethoxy-3-β-(4-fluorophenyl)tropane 1,5-naphthalenedisulfonate monohydrate (WIN 35,428) and methylphenidate] at low (0.1-mg/kg) doses that were minimally active failed to shift the dose-effect function for discriminative-stimulus effects of cocaine to the left more than 2-fold. At 0.32 mg/kg the DAT inhibitors alone shifted the cocaine dose-effect function leftward 24- or 6.6-fold, respectively. The R antagonists (BD1008, BD1047, and BD1063) failed to fully substitute for cocaine, although BD1008 and BD1047 substituted partially. At 10 mg/kg, BD1008, BD1047, or BD1063 alone shifted the cocaine dose-effect function leftward less than 6.0-fold. In combination with 0.1 mg/kg WIN 35,428, the 10 mg/kg doses of R antagonists shifted the cocaine dose-effect function from 12.3- to 36.7-fold leftward, and with 0.32 mg/kg WIN 35,428 from 14.3- to 440-fold leftward. In combination with 0.1 mg/kg methylphenidate, those R antagonist doses shifted the cocaine dose-effect function from 5.5- to 55.0-fold leftward, and with 0.32 mg/kg methylphenidate from 10.5- to 48.1-fold leftward. The present results suggest that dual DAT/R inhibition produces agonist-like subjective effects that may promote decreases in self-administration obtained in previous studies. SIGNIFICANCE STATEMENT There is currently no approved medication for treating stimulant abuse, although dopamine uptake inhibitors in combination with sigma receptor (R) antagonists decrease cocaine self-administration in laboratory animals. The present study assessed how this combination alters the discriminative-stimulus effects of cocaine in male rats. Results suggest that concurrent dopamine uptake inhibition and R antagonism together may promote decreases in self-administration, possibly by mimicking the subjective effects extant when subjects cease continued cocaine self-administration. Full Article
rt The Minor Phytocannabinoid Delta-8-Tetrahydrocannabinol Attenuates Collagen-Induced Arthritic Inflammation and Pain-Depressed Behaviors [Special Section: Cannabinoid Signaling in Human Health and Disease] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Patients with arthritis report using cannabis for pain management, and the major cannabinoid delta-9-tetrahydrocannabinol (9-THC) has anti-inflammatory properties, yet the effects of minor cannabinoids on arthritis are largely unknown. The goal of the present study was to determine the antiarthritic potential of the minor cannabinoid delta-8-tetrahydrocannabinol (8-THC) using the collagen-induced arthritis (CIA) mouse model. Adult male DBA/1J mice were immunized and boosted 21 days later with an emulsion of collagen and complete Freund’s adjuvant. Beginning on the day of the booster, mice were administered twice-daily injections of 8-THC (3 or 30 mg/kg), the steroid dexamethasone (2 mg/kg), or vehicle for two weeks. Dorsal-ventral paw thickness and qualitative measures of arthritis were recorded daily, and latency to fall from an inverted grid was measured on alternating days, to determine arthritis severity and functional impairment. On the final day of testing, spontaneous wire-climbing behavior and temperature preference in a thermal gradient ring were measured to assess CIA-depressed behavior. The 8-THC treatment (30 mg/kg) reduced paw swelling and qualitative signs of arthritis. 8-THC also blocked CIA-depressed climbing and CIA-induced preference for a heated floor without producing locomotor effects but did not affect latency to fall from a wire grid. In alignment with the morphologic and behavioral assessments in vivo, histology revealed that 8-THC reduced synovial inflammation, proteoglycan loss and cartilage and bone erosion in the foot joints in a dose-dependent manner. Together, these findings suggest that 8-THC not only blocked morphologic changes but also prevented functional loss caused by collagen-induced arthritis. SIGNIFICANCE STATEMENT Despite increasing use of cannabis products, the potential effects of minor cannabinoids are largely unknown. Here, the minor cannabinoid delta-8-tetrahydrocannabinol blocked the development of experimentally induced arthritis by preventing both pathophysiological as well as functional effects of the disease model. These data support the development of novel cannabinoid treatments for inflammatory arthritis. Full Article
rt Analgesic Properties of Next-Generation Modulators of Endocannabinoid Signaling: Leveraging Modern Tools for the Development of Novel Therapeutics [Special Section: Cannabinoid Signaling in Human Health and Disease-Minireview] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Targeting the endocannabinoid (eCB) signaling system for pain relief is an important treatment option that is only now beginning to be mechanistically explored. In this review, we focus on two recently appreciated cannabinoid-based targeting strategies, treatments with cannabidiol (CBD) and α/β-hydrolase domain containing 6 (ABHD6) inhibitors, which have the exciting potential to produce pain relief through distinct mechanisms of action and without intoxication. We review evidence on plant-derived cannabinoids for pain, with an emphasis on CBD and its multiple molecular targets expressed in pain pathways. We also discuss the function of eCB signaling in regulating pain responses and the therapeutic promises of inhibitors targeting ABHD6, a 2-arachidonoylglycerol (2-AG)-hydrolyzing enzyme. Finally, we discuss how the novel cannabinoid biosensor GRABeCB2.0 may be leveraged to enable the discovery of targets modulated by cannabinoids at a circuit-specific level. SIGNIFICANCE STATEMENT Cannabis has been used by humans as an effective medicine for millennia, including for pain management. Recent evidence emphasizes the therapeutic potential of compounds that modulate endocannabinoid signaling. Specifically, cannabidiol and inhibitors of the enzyme ABHD6 represent promising strategies to achieve pain relief by modulating endocannabinoid signaling in pain pathways via distinct, nonintoxicating mechanisms of action. Full Article
rt Cannabis and Cannabinoid Signaling: Research Gaps and Opportunities [Special Section: Cannabinoid Signaling in Human Health and Disease-Commentary] By jpet.aspetjournals.org Published On :: 2024-10-18T07:04:15-07:00 Cannabis and its products have been used for centuries for both medicinal and recreational purposes. The recent widespread legalization of cannabis has vastly expanded its use in the United States across all demographics except for adolescents. Meanwhile, decades of research have advanced our knowledge of cannabis pharmacology and particularly of the endocannabinoid system with which the components of cannabis interact. This research has revealed multiple targets and approaches for manipulating the system for therapeutic use and to ameliorate cannabis toxicity or cannabis use disorder. Research has also led to new questions that underscore the potential risks of its widespread use, particularly the enduring consequences of exposure during critical windows of brain development or for consumption of large daily doses of cannabis with high content 9-tetrahydrocannabinol. This article highlights current neuroscience research on cannabis that has shed light on therapeutic opportunities and potential adverse consequences of misuse and points to gaps in knowledge that can guide future research. SIGNIFICANCE STATEMENT Cannabis use has escalated with its increased availability. Here, the authors highlight the challenges of cannabis research and the gaps in our knowledge of cannabis pharmacology and of the endocannabinoid system that it targets. Future research that addresses these gaps is needed so that the endocannabinoid system can be leveraged for safe and effective use. Full Article
rt Validation of an Artificial Intelligence-Based Prediction Model Using 5 External PET/CT Datasets of Diffuse Large B-Cell Lymphoma By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 The aim of this study was to validate a previously developed deep learning model in 5 independent clinical trials. The predictive performance of this model was compared with the international prognostic index (IPI) and 2 models incorporating radiomic PET/CT features (clinical PET and PET models). Methods: In total, 1,132 diffuse large B-cell lymphoma patients were included: 296 for training and 836 for external validation. The primary outcome was 2-y time to progression. The deep learning model was trained on maximum-intensity projections from PET/CT scans. The clinical PET model included metabolic tumor volume, maximum distance from the bulkiest lesion to another lesion, SUVpeak, age, and performance status. The PET model included metabolic tumor volume, maximum distance from the bulkiest lesion to another lesion, and SUVpeak. Model performance was assessed using the area under the curve (AUC) and Kaplan–Meier curves. Results: The IPI yielded an AUC of 0.60 on all external data. The deep learning model yielded a significantly higher AUC of 0.66 (P < 0.01). For each individual clinical trial, the model was consistently better than IPI. Radiomic model AUCs remained higher for all clinical trials. The deep learning and clinical PET models showed equivalent performance (AUC, 0.69; P > 0.05). The PET model yielded the highest AUC of all models (AUC, 0.71; P < 0.05). Conclusion: The deep learning model predicted outcome in all trials with a higher performance than IPI and better survival curve separation. This model can predict treatment outcome in diffuse large B-cell lymphoma without tumor delineation but at the cost of a lower prognostic performance than with radiomics. Full Article
rt Evaluation of Fibroblast Activation Protein Expression Using 68Ga-FAPI46 PET in Hypertension-Induced Tissue Changes By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 Chronic hypertension leads to injury and fibrosis in major organs. Fibroblast activation protein (FAP) is one of key molecules in tissue fibrosis, and 68Ga-labeled FAP inhibitor-46 (FAPI46) PET is a recently developed method for evaluating FAP. The aim of this study was to evaluate FAP expression and fibrosis in a hypertension model and to test the feasibility of 68Ga-FAPI46 PET in hypertension. Methods: Hypertension was induced in mice by angiotensin II infusion for 4 wk. 68Ga-FAPI46 biodistribution studies and PET scanning were conducted at 1, 2, and 4 wk after hypertension modeling, and uptake in the major organs was measured. The FAP expression and fibrosis formation of the heart and kidney tissues were analyzed and compared with 68Ga-FAPI46 uptake. Subgroups of the hypertension model underwent angiotensin receptor blocker administration and high-dose FAPI46 blocking, for comparison. As a preliminary human study, 68Ga-FAPI46 PET images of lung cancer patients were analyzed and compared between hypertension and control groups. Results: Uptake of 68Ga-FAPI46 in the heart and kidneys was significantly higher in the hypertension group than in the sham group as early as week 1 and decreased after week 2. The uptake was specifically blocked in the high-dose blocking study. Immunohistochemistry also revealed FAP expression in both heart and kidney tissues. However, overt fibrosis was observed in the heart, whereas it was absent from the kidneys. The angiotensin receptor blocker–treated group showed lower uptake in the heart and kidneys than did the hypertension group. In the pilot human study, renal uptake of 68Ga-FAPI46 significantly differed between the hypertension and control groups. Conclusion: In hypertension, FAP expression is increased in the heart and kidneys from the early phases and decreases over time. FAP expression appears to represent fibrosis activity preceding or underlying fibrotic tissue formation. 68Ga-FAPI46 PET has potential as an effective imaging method for evaluating FAP expression in progressive fibrosis by hypertension. Full Article
rt Intrapatient Intermetastatic Heterogeneity Determined by Triple-Tracer PET Imaging in mCRPC Patients and Correlation to Survival: The 3TMPO Cohort Study By jnm.snmjournals.org Published On :: 2024-11-01T04:25:31-07:00 Intrapatient intermetastatic heterogeneity (IIH) has been demonstrated in metastatic castration-resistant prostate cancer (mCRPC) patients and is of the utmost importance for radiopharmaceutical therapy (RPT) eligibility. This study was designed to determine the prevalence of IIH and RPT eligibility in mCRPC patients through a triple-tracer PET imaging strategy. Methods: This was a multisite prospective observational study in which mCRPC patients underwent both 18F-FDG and 68Ga-prostate-specific membrane antigen (PSMA)–617 PET/CT scans. A third scan with 68Ga-DOTATATE, a potential biomarker of neuroendocrine differentiation, was performed if an 18F-FDG–positive/68Ga-PSMA–negative lesion was found. Per-tracer lesion positivity was defined as having an uptake at least 50% above that of the liver. IIH prevalence was defined as the percentage of participants having at least 2 lesions with discordant features on multitracer PET. Results: IIH was observed in 81 patients (82.7%), and at least 1 18F-FDG–positive/68Ga-PSMA–negative lesion was found in 45 patients (45.9%). Of the 37 participants who also underwent 68Ga-DOTATATE PET/CT, 6 (16.2%) had at least 1 68Ga-DOTATATE–positive lesion. In total, 12 different combinations of lesion imaging phenotypes were observed. On the basis of our prespecified criteria, 52 (53.1%) participants were determined to be eligible for PSMA RPT, but none for DOTATATE RPT. Patients with IIH had a significantly shorter median overall survival than patients without IIH (9.5 mo vs. not reached; log-rank P = 0.03; hazard ratio, 2.7; 95% CI, 1.1–6.8). Conclusion: Most mCRPC patients showed IIH, which was associated with shorter overall survival. On the basis of a triple-tracer PET approach, multiple phenotypic combinations were found. Correlation of these imaging phenotypes with genomics and treatment response will be relevant for precision medicine. Full Article
rt Ironing Out the Mechanism of gp130 Signaling [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 gp130 functions as a shared signal-transducing subunit not only for interleukin (IL)-6 but also for eight other human cytokine receptor complexes. The IL-6 signaling pathway mediated through gp130 encompasses classical, trans, or cluster signaling, intricately regulated by a diverse array of modulators affecting IL-6, its receptor, and gp130. Currently, only a limited number of small molecule antagonists and agonists for gp130 are known. This review aims to comprehensively examine the current knowledge of these modulators and provide insights into their pharmacological properties, particularly in the context of cancer and other diseases. Notably, the prominent gp130 modulators SC144, bazedoxifene, and raloxifene are discussed in detail, with a specific focus on the discovery of SC144’s iron-chelating properties. This adds a new dimension to the understanding of its pharmacological effects and therapeutic potential in conditions where iron homeostasis is significant. Our bioinformatic analysis of gp130 and genes related to iron homeostasis reveals insightful correlations, implicating the role of iron in the gp130 signaling pathway. Overall, this review contributes to the evolving understanding of gp130 modulation and its potential therapeutic applications in various disease contexts. Significance Statement This perspective provides a timely and comprehensive analysis of advancements in gp130 signaling research, emphasizing the therapeutic implications of the currently available modulators. Bioinformatic analysis demonstrates potential interplay between gp130 and genes that regulate iron homeostasis, suggesting new therapeutic avenues. By combining original research findings with a broader discussion of gp130's therapeutic potential, this perspective significantly contributes to the field. Full Article
rt Intestinal Lymphatic Biology, Drug Delivery, and Therapeutics: Current Status and Future Directions [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Historically, the intestinal lymphatics were considered passive conduits for fluids, immune cells, dietary lipids, lipid soluble vitamins, and lipophilic drugs. Studies of intestinal lymphatic drug delivery in the late 20th century focused primarily on the drugs’ physicochemical properties, especially high lipophilicity, that resulted in intestinal lymphatic transport. More recent discoveries have changed our traditional view by demonstrating that the lymphatics are active, plastic, and tissue-specific players in a range of biological and pathological processes, including within the intestine. These findings have, in turn, inspired exploration of lymph-specific therapies for a range of diseases, as well as the development of more sophisticated strategies to actively deliver drugs or vaccines to the intestinal lymph, including a range of nanotechnologies, lipid prodrugs, and lipid-conjugated materials that "hitchhike" onto lymphatic transport pathways. With the increasing development of novel therapeutics such as biologics, there has been interest in whether these therapeutics are absorbed and transported through intestinal lymph after oral administration. Here we review the current state of understanding of the anatomy and physiology of the gastrointestinal lymphatic system in health and disease, with a focus on aspects relevant to drug delivery. We summarize the current state-of-the-art approaches to deliver drugs and quantify their uptake into the intestinal lymphatic system. Finally, and excitingly, we discuss recent examples of significant pharmacokinetic and therapeutic benefits achieved via intestinal lymphatic drug delivery. We also propose approaches to advance the development and clinical application of intestinal lymphatic delivery strategies in the future. Significance Statement This comprehensive review details the understanding of the anatomy and physiology of the intestinal lymphatic system in health and disease, with a focus on aspects relevant to drug delivery. It highlights current state-of-the-art approaches to deliver drugs to the intestinal lymphatics and the shift toward the use of these strategies to achieve pharmacokinetic and therapeutic benefits for patients. Full Article
rt Somatostatin: Linking Cognition and Alzheimer Disease to Therapeutic Targeting [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Over 4 decades of research support the link between Alzheimer disease (AD) and somatostatin [somatotropin-releasing inhibitory factor (SRIF)]. SRIF and SRIF-expressing neurons play an essential role in brain function, modulating hippocampal activity and memory formation. Loss of SRIF and SRIF-expressing neurons in the brain rests at the center of a series of interdependent pathological events driven by amyloid-β peptide (Aβ), culminating in cognitive decline and dementia. The connection between the SRIF and AD further extends to the neuropsychiatric symptoms, seizure activity, and inflammation, whereas preclinical AD investigations show SRIF or SRIF receptor agonist administration capable of enhancing cognition. SRIF receptor subtype-4 activation in particular presents unique attributes, with the potential to mitigate learning and memory decline, reduce comorbid symptoms, and enhance enzymatic degradation of Aβ in the brain. Here, we review the links between SRIF and AD along with the therapeutic implications. Significance Statement Somatostatin and somatostatin-expressing neurons in the brain are extensively involved in cognition. Loss of somatostatin and somatostatin-expressing neurons in Alzheimer disease rests at the center of a series of interdependent pathological events contributing to cognitive decline and dementia. Targeting somatostatin-mediated processes has significant therapeutic potential for the treatment of Alzheimer disease. Full Article
rt Posttranslational Modifications of {alpha}-Synuclein, Their Therapeutic Potential, and Crosstalk in Health and Neurodegenerative Diseases [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 α-Synuclein (α-Syn) aggregation in Lewy bodies and Lewy neurites has emerged as a key pathogenetic feature in Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Various factors, including posttranslational modifications (PTMs), can influence the propensity of α-Syn to misfold and aggregate. PTMs are biochemical modifications of a protein that occur during or after translation and are typically mediated by enzymes. PTMs modulate several characteristics of proteins including their structure, activity, localization, and stability. α-Syn undergoes various posttranslational modifications, including phosphorylation, ubiquitination, SUMOylation, acetylation, glycation, O-GlcNAcylation, nitration, oxidation, polyamination, arginylation, and truncation. Different PTMs of a protein can physically interact with one another or work together to influence a particular physiological or pathological feature in a process known as PTMs crosstalk. The development of detection techniques for the cooccurrence of PTMs in recent years has uncovered previously unappreciated mechanisms of their crosstalk. This has led to the emergence of evidence supporting an association between α-Syn PTMs crosstalk and synucleinopathies. In this review, we provide a comprehensive evaluation of α-Syn PTMs, their impact on misfolding and pathogenicity, the pharmacological means of targeting them, and their potential as biomarkers of disease. We also highlight the importance of the crosstalk between these PTMs in α-Syn function and aggregation. Insight into these PTMS and the complexities of their crosstalk can improve our understanding of the pathogenesis of synucleinopathies and identify novel targets of therapeutic potential. Significance Statement α-Synuclein is a key pathogenic protein in Parkinson’s disease and other synucleinopathies, making it a leading therapeutic target for disease modification. Multiple posttranslational modifications occur at various sites in α-Synuclein and alter its biophysical and pathological properties, some interacting with one another to add to the complexity of the pathogenicity of this protein. This review details these modifications, their implications in disease, and potential therapeutic opportunities. Full Article
rt Bile Acid Signaling in Metabolic and Inflammatory Diseases and Drug Development [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates biliary secretion of lipids, endogenous metabolites, and xenobiotics. In intestine, bile acids facilitate the digestion and absorption of dietary lipids and fat-soluble vitamins. Through activation of nuclear receptors and G protein-coupled receptors and interaction with gut microbiome, bile acids critically regulate host metabolism and innate and adaptive immunity and are involved in the pathogenesis of cholestasis, metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, type-2 diabetes, and inflammatory bowel diseases. Bile acids and their derivatives have been developed as potential therapeutic agents for treating chronic metabolic and inflammatory liver diseases and gastrointestinal disorders. Significance Statement Bile acids facilitate biliary cholesterol solubilization and dietary lipid absorption, regulate host metabolism and immunity, and modulate gut microbiome. Targeting bile acid metabolism and signaling holds promise for treating metabolic and inflammatory diseases. Full Article
rt Drug-Drug Interactions and Synergy: From Pharmacological Models to Clinical Application [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 This review explores the concept of synergy in pharmacology, emphasizing its importance in optimizing treatment outcomes through the combination of drugs with different mechanisms of action. Synergy, defined as an effect greater than the expected additive effect elicited by individual agents according to specific predictive models, offers a promising approach to enhance therapeutic efficacy while minimizing adverse events. The historical evolution of synergy research, from ancient civilizations to modern pharmacology, highlights the ongoing quest to understand and harness synergistic interactions. Key concepts, such as concentration-response curves, additive effects, and predictive models, are discussed in detail, emphasizing the need for accurate assessment methods throughout translational drug development. Although various mathematical models exist for synergy analysis, selecting the appropriate model and software tools remains a challenge, necessitating careful consideration of experimental design and data interpretation. Furthermore, this review addresses practical considerations in synergy assessment, including preclinical and clinical approaches, mechanism of action, and statistical analysis. Optimizing synergy requires attention to concentration/dose ratios, target site localization, and timing of drug administration, ensuring that the benefits of combination therapy detected bench-side are translatable into clinical practice. Overall, the review advocates for a systematic approach to synergy assessment, incorporating robust statistical analysis, effective and simplified predictive models, and collaborative efforts across pivotal sectors, such as academic institutions, pharmaceutical companies, and regulatory agencies. By overcoming critical challenges and maximizing therapeutic potential, effective synergy assessment in drug development holds promise for advancing patient care. Significance Statement Combining drugs with different mechanisms of action for synergistic interactions optimizes treatment efficacy and safety. Accurate interpretation of synergy requires the identification of the expected additive effect. Despite innovative models to predict the additive effect, consensus in drug-drug interactions research is lacking, hindering the bench-to-bedside development of combination therapies. Collaboration among science, industry, and regulation is crucial for advancing combination therapy development, ensuring rigorous application of predictive models in clinical settings. Full Article
rt Glatiramer Acetate for the Treatment of Multiple Sclerosis: From First-Generation Therapy to Elucidation of Immunomodulation and Repair [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), with a putative autoimmune origin and complex pathogenesis. Modification of the natural history of MS by reducing relapses and slowing disability accumulation was first attained in the 1990 s with the development of the first-generation disease-modifying therapies. Glatiramer acetate (GA), a copolymer of L-alanine, L-lysine, L-glutamic acid, and L-tyrosine, was discovered due to its ability to suppress the animal model of MS, experimental autoimmune encephalomyelitis. Extensive clinical trials and long-term assessments established the efficacy and the safety of GA. Furthermore, studies of the therapeutic processes induced by GA in animal models and in MS patients indicate that GA affects various levels of the innate and the adaptive immune response, generating deviation from proinflammatory to anti-inflammatory pathways. This includes competition for binding to antigen presenting cells; driving dendritic cells, monocytes, and B-cells toward anti-inflammatory responses; and stimulating T-helper 2 and T-regulatory cells. The immune cells stimulated by GA reach the CNS and secrete in situ anti-inflammatory cytokines alleviating the pathological processes. Furthermore, cumulative findings reveal that in addition to its immunomodulatory effect, GA promotes neuroprotective repair processes such as neurotrophic factors secretion, remyelination, and neurogenesis. This review aims to provide an overview of MS pathology diagnosis and treatment as well as the diverse mechanism of action of GA. Significance Statement Understanding the complex MS immune pathogenesis provided multiple targets for therapeutic intervention, resulting in a plethora of agents, with various mechanisms of action, efficacy, and safety profiles. However, promoting repair beyond the body’s limited spontaneous extent is still a major challenge. GA, one of the first approved disease-modifying therapies, induces diverse immunomodulatory effects. Furthermore, GA treatment results in elevated neurotrophic factors secretion, remyelination and neurogenesis, supporting the notion that immunomodulatory treatment can support in situ a growth-promoting and repair environment. Full Article
rt Roles of Individual Human Cytochrome P450 Enzymes in Drug Metabolism [Review Article] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Our knowledge of the roles of individual cytochrome P450 (P450) enzymes in drug metabolism has developed considerably in the past 30 years, and this base has been of considerable use in avoiding serious issues with drug interactions and issues due to variations. Some newer approaches are being considered for "phenotyping" metabolism reactions with new drug candidates. Endogenous biomarkers are being used for noninvasive estimation of levels of individual P450 enzymes. There is also the matter of some remaining "orphan" P450s, which have yet to be assigned reactions. Practical problems that continue in drug development include predicting drug-drug interactions, predicting the effects of polymorphic and other P450 variations, and evaluating interspecies differences in drug metabolism, particularly in the context of "metabolism in safety testing" regulatory issues ["disproportionate (human) metabolites"]. Significance Statement Cytochrome P450 enzymes are the major catalysts involved in drug metabolism. The characterization of their individual roles has major implications in drug development and clinical practice. Full Article
rt The 75-Year Anniversary of the Department of Physiology and Pharmacology at Karolinska Institutet--Examples of Recent Accomplishments and Future Perspectives [75th Anniversary Celebration Collection Special Section-Perspective] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Karolinska Institutet is a medical university encompassing 21 departments distributed across three departmental or campus groups. Pharmacological research has a long and successful tradition at the institute with a multitude of seminal findings in the areas of neuronal control of vasodilatation, cardiovascular pharmacology, neuropsychopharmacology, receptor pharmacology, and pharmacogenomics that resulted in, among many other recognitions, two Nobel prizes in Physiology and Medicine, one in 1970 to Ulf von Euler for his discovery of the processes involved in storage, release, and inactivation of neurotransmitters and the other in 1982 to Sune Bergström and Bengt Samuelsson for their work on prostaglandins and the discovery of leukotrienes. Pharmacology at Karolinska Institutet has over the last decade been ranked globally among the top 10 according to the QS World University Ranking. With the Department of Physiology and Pharmacology now celebrating its 75-year anniversary, we wanted to take this as an opportunity to showcase recent research achievements and how they paved the way for current activities at the department. We emphasize examples from preclinical and clinical research where the dpartment's integrative environment and robust infrastructure have successfully facilitated the translation of findings into clinical applications and patient benefits. The close collaboration between preclinical scientists and clinical researchers across various disciplines, along with a strong network of partnerships within the department and beyond, positions us to continue leading world-class pharmacological research at the Department of Physiology and Pharmacology for decades to come. Significance Statement Pharmacological research at Karolinska Institutet has a long and successful history. Given the 75-year anniversary of the Department of Physiology and Pharmacology, this perspective provides an overview of recent departmental achievements and future trajectories. For these developments, interdisciplinary and intersectoral collaborations and a clear focus on result translation are key elements to continue its legacy of world-leading pharmacological research. Full Article
rt Neuroactive Kynurenines as Pharmacological Targets: New Experimental Tools and Exciting Therapeutic Opportunities [75th Anniversary Celebration Collection Special Section] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Both preclinical and clinical studies implicate functional impairments of several neuroactive metabolites of the kynurenine pathway (KP), the major degradative cascade of the essential amino acid tryptophan in mammals, in the pathophysiology of neurologic and psychiatric diseases. A number of KP enzymes, such as tryptophan 2,3-dioxygenase (TDO2), indoleamine 2,3-dioxygenases (IDO1 and IDO2), kynurenine aminotransferases (KATs), kynurenine 3-monooxygenase (KMO), 3-hydroxyanthranilic acid oxygenase (3-HAO), and quinolinic acid phosphoribosyltransferase (QPRT), control brain KP metabolism in health and disease and are therefore increasingly considered to be promising targets for the treatment of disorders of the nervous system. Understanding the distribution, cellular expression, and regulation of KP enzymes and KP metabolites in the brain is therefore critical for the conceptualization and implementation of successful therapeutic strategies. Significance Statement Studies have implicated the kynurenine pathway of tryptophan in the pathophysiology of neurologic and psychiatric diseases. Key enzymes of the kynurenine pathway regulate brain metabolism in both health and disease, making them promising targets for treating these disorders. Therefore, understanding the distribution, cellular expression, and regulation of these enzymes and metabolites in the brain is critical for developing effective therapeutic strategies. This review endeavors to describe these processes in detail.: Full Article
rt Seventy-Five Years of Interactions: The Department of Physiology and Pharmacology at Karolinska Institutet and Pharmacological Reviews [75th Anniversary Celebration Collection Special Section-Editorial] By pharmrev.aspetjournals.org Published On :: 2024-10-16T07:40:25-07:00 Full Article
rt Low-Field (64 mT) Portable MRI for Rapid Point-of-Care Diagnosis of Dissemination in Space in Patients Presenting with Optic Neuritis [CLINICAL PRACTICE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Low-field 64 mT portable brain MRI has recently shown diagnostic promise for MS. This study aimed to evaluate the utility of portable MRI (pMRI) in assessing dissemination in space (DIS) in patients presenting with optic neuritis and determine whether deploying pMRI in the MS clinic can shorten the time from symptom onset to MRI. MATERIALS AND METHODS: Newly diagnosed patients with optic neuritis referred to a tertiary academic MS center from July 2022 to January 2024 underwent both point-of-care pMRI and subsequent 3T conventional MRI (cMRI). Images were evaluated for periventricular (PV), juxtacortical (JC), and infratentorial (IT) lesions. DIS was determined on brain MRI per 2017 McDonald criteria. Test characteristics were computed by using cMRI as the reference. Interrater and intermodality agreement between pMRI and cMRI were evaluated by using the Cohen . Time from symptom onset to pMRI and cMRI during the study period was compared with the preceding 1.5 years before pMRI implementation by using Kruskal-Wallis with post hoc Dunn tests. RESULTS: Twenty patients (median age: 32.5 years [interquartile range {IQR}, 28–40]; 80% women) were included, of whom 9 (45%) and 5 (25%) had DIS on cMRI and pMRI, respectively. Median time interval between pMRI and cMRI was 7 days (IQR, 3.5–12.5). Interrater agreement was very good for PV (95%, = 0.89), and good for JC and IT lesions (90%, = 0.69 for both). Intermodality agreement was good for PV (90%, = 0.80) and JC (85%, = 0.63), and moderate for IT lesions (75%, = 0.42) and DIS (80%, = 0.58). pMRI had a sensitivity of 56% and specificity of 100% for DIS. The median time from symptom onset to pMRI was significantly shorter (8.5 days [IQR 7–12]) compared with the interval to cMRI before pMRI deployment (21 days [IQR 8–49], n = 50) and after pMRI deployment (15 days [IQR 12–29], n = 30) (both P < .01). Time from symptom onset to cMRI in those periods was not significantly different (P = .29). CONCLUSIONS: In patients with optic neuritis, pMRI exhibited moderate concordance, moderate sensitivity, and high specificity for DIS compared with cMRI. Its integration into the MS clinic reduced the time from symptom onset to MRI. Further studies are warranted to evaluate the role of pMRI in expediting early MS diagnosis and as an imaging tool in resource-limited settings. Full Article
rt Enzyme Replacement Therapy for CLN2 Disease: MRI Volumetry Shows Significantly Slower Volume Loss Compared with a Natural History Cohort [CLINICAL PRACTICE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Neuronal ceroid lipofuscinoses are a group of neurodegenerative disorders. Recently, enzyme replacement therapy (ERT) was approved for neuronal ceroid lipofuscinosis type 2 (CLN2), a subtype of neuronal ceroid lipofuscinoses. The aim of this study was to quantify brain volume loss in CLN2 disease in patients on ERT in comparison with a natural history cohort using MRI. MATERIALS AND METHODS: Nineteen (14 female, 5 male) patients with CLN2 disease at 1 UK center were studied using serial 3D T1-weighted MRI (follow-up time, 1–9 years). Brain segmentation was performed using FreeSurfer. Volume measurements for supratentorial gray and white matter, deep gray matter (basal ganglia/thalami), the lateral ventricles, and cerebellar gray and white matter were recorded. The volume change with time was analyzed using a linear mixed-effects model excluding scans before treatment onset. Comparison was made with a published natural history cohort of 12 patients (8 female, 4 male), which was re-analyzed using the same method. RESULTS: Brain volume loss of all segmented brain regions was much slower in treated patients compared with the natural history cohort. For example, supratentorial gray matter volume in treated patients decreased by a mean of 3% (SD, 0.74%) (P < .001) annually compared with an annual volume loss of a mean of 16.8% (SD, 1.5%) (P < .001) in the natural history cohort. CONCLUSIONS: Our treatment cohort showed a significantly slower rate of brain parenchymal volume loss compared with a natural history cohort in several anatomic regions. Our results complement prior clinical data that found a positive response to ERT. We demonstrate that automated MRI volumetry is a sensitive tool to monitor treatment response in children with CLN2 disease. Full Article
rt Arterial Spin-Labeling Perfusion Lightbulb Sign: An Imaging Biomarker of Pediatric Posterior Fossa Hemangioblastoma [CLINICAL PRACTICE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Hemangioblastoma is a rare vascular tumor that occurs within the central nervous system in children. Differentiating hemangioblastoma from other posterior fossa tumors can be challenging on imaging, and preoperative diagnosis can change the neurosurgical approach. We hypothesize that a "lightbulb sign" on the arterial spin-labeling (ASL) sequence (diffuse homogeneous intense hyperperfusion within the solid component of the tumor) will provide additional imaging finding to differentiate hemangioblastoma from other posterior fossa tumors. MATERIALS AND METHODS: In this retrospective comparative observational study, we only included pathology-proved cases of hemangioblastoma, while the control group consisted of other randomly selected pathology-proved posterior fossa tumors from January 2022 to January 2024. Two blinded neuroradiologists analyzed all applicable MRI sequences, including ASL sequence if available. ASL was analyzed for the lightbulb sign. Disagreements between the radiologists were resolved by a third pediatric neuroradiologist. 2 and Fisher exact test were used to analyze the data. RESULTS: Ninety-five patients were enrolled in the study; 57 (60%) were boys. The median age at diagnosis was 8 years old (interquartile range: 3–14). Of the enrolled patients, 8 had hemangioblastoma, and 87 had other posterior fossa tumors, including medulloblastoma (n = 31), pilocytic astrocytoma (n = 23), posterior fossa ependymoma type A (n = 16), and other tumors (n = 17). The comparison of hemangioblastoma versus nonhemangioblastoma showed that peripheral edema (P = .02) and T2-flow void (P = .02) favor hemangioblastoma, whereas reduced diffusion (low ADC) (P = .002) and ventricular system extension (P = .001) favor nonhemangioblastoma tumors. Forty-two cases also had ASL perfusion sequences. While high perfusion favors hemangioblastoma (P = .03), the lightbulb sign shows a complete distinction because all the ASL series of hemangioblastoma cases (n = 4) showed the lightbulb sign, whereas none of the nonhemangioblastoma cases (n = 38) showed the sign (P < .001). CONCLUSIONS: Lightbulb-like intense and homogeneous hyperperfusion patterns on ASL are helpful in diagnosing posterior fossa hemangioblastoma in children. Full Article
rt Prognosis of Proximal and Distal Vertebrobasilar Artery Stent Placement [CLINICAL PRACTICE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Vertebrobasilar artery stent placement (VBS) is potentially effective in preventing recurrent posterior circulation strokes; however, the incidences of in-stent restenosis and stented-territory ischemic events based on the location of stent placement have rarely been investigated. We aimed to investigate the characteristics and prognosis of VBS between intracranial and extracranial. MATERIALS AND METHODS: This study was single-center retrospective cohort study, and we obtained medical records of patients who underwent VBS. We compared clinical and periprocedural factors between extracranial and intracranial VBS. The primary outcomes included the incidence of in-stent restenosis (>50% reduction in lumen diameter) and stented-territory ischemic events. We compared the incidence of in-stent restenosis and stented-territory ischemic events by using Kaplan-Meier curves. RESULTS: Of the 105 patients, 41 (39.0%) underwent extracranial VBS, and 64 (61.0%) underwent intracranial VBS. During the follow-up, the incidences of in-stent restenosis and stented-territory ischemic events were 15.2% and 22.9%, respectively. The procedure time was longer (47.7 ± 19.5 minutes versus 74.5 ± 35.2 minutes, P < .001), and the rate of residual stenosis (≥30%) just after VBS was higher (2 [4.9%] versus 24 [37.5%], P < .001) in intracranial VBS than in extracranial VBS. Also, the incidences of in-stent restenosis were significantly higher in intracranial VBS than in extracranial VBS (4.9% versus 21.9%, P = .037). On the other hand, the incidences of stented-territory ischemic events (7.3% versus 32.8%, P < .001) were significantly higher in intracranial VBS than in extracranial VBS. The main mechanisms of stroke were artery-to-artery embolism (2 [66.7%]) in extracranial VBS, and artery-to-artery embolism (9 [42.9%]) and branch atheromatous disease (8 [38.1%]) in intracranial VBS. The Kaplan-Meier curve demonstrated a higher incidence of in-stent restenosis and stented-territory ischemic events in intracranial VBS than in extracranial VBS (P = .008 and P = .002, respectively). CONCLUSIONS: During the follow-up, the incidence of in-stent restenosis and stented-territory ischemic events was higher in patients with intracranial VBS than in those with extracranial VBS. The higher rates of postprocedural residual stenosis might have contributed to the increased risk of in-stent restenosis. Furthermore, prolonged procedure time and additional stroke mechanism, including branch atheromatous disease, might be associated with a higher risk of stented-territory ischemic events in intracranial VBS. Full Article
rt Clinical and Pathophysiologic Correlates of Basilar Artery Measurements in Fabry Disease [CLINICAL PRACTICE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Alterations of the basilar artery (BA) anatomy have been suggested as a possible MRA feature of Fabry disease (FD). Nonetheless, no information about their clinical or pathophysiologic correlates is available, limiting our comprehension of the real impact of vessel remodeling in FD. MATERIALS AND METHODS: Brain MRIs of 53 subjects with FD (mean age, 40.7 [SD, 12.4] years; male/female ratio = 23:30) were collected in this single-center study. Mean BA diameter and its tortuosity index were calculated on MRA. Possible correlations between these metrics and clinical, laboratory, and advanced imaging variables of the posterior circulation were tested. In a subgroup of 20 subjects, a 2-year clinical and imaging follow-up was available, and possible longitudinal changes of these metrics and their ability to predict clinical scores were also probed. RESULTS: No significant association was found between MRA metrics and any clinical, laboratory, or advanced imaging variable (P values ranging from –0.006 to 0.32). At the follow-up examination, no changes were observed with time for the mean BA diameter (P = .84) and the tortuosity index (P = .70). Finally, baseline MRA variables failed to predict the clinical status of patients with FD at follow-up (P = .42 and 0.66, respectively). CONCLUSIONS: Alterations of the BA in FD lack of any meaningful association with clinical, laboratory, or advanced imaging findings collected in this study. Furthermore, this lack of correlation seems constant across time, suggesting stability over time. Taken together, these results suggest that the role of BA dolichoectasia in FD should be reconsidered. Full Article
rt Deep Learning-Based Reconstruction of 3D T1 SPACE Vessel Wall Imaging Provides Improved Image Quality with Reduced Scan Times: A Preliminary Study [ARTIFICIAL INTELLIGENCE] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Intracranial vessel wall imaging is technically challenging to implement, given the simultaneous requirements of high spatial resolution, excellent blood and CSF signal suppression, and clinically acceptable gradient times. Herein, we present our preliminary findings on the evaluation of a deep learning–optimized sequence using T1-weighted imaging. MATERIALS AND METHODS: Clinical and optimized deep learning–based image reconstruction T1 3D Sampling Perfection with Application optimized Contrast using different flip angle Evolution (SPACE) were evaluated, comparing noncontrast sequences in 10 healthy controls and postcontrast sequences in 5 consecutive patients. Images were reviewed on a Likert-like scale by 4 fellowship-trained neuroradiologists. Scores (range, 1–4) were separately assigned for 11 vessel segments in terms of vessel wall and lumen delineation. Additionally, images were evaluated in terms of overall background noise, image sharpness, and homogeneous CSF signal. Segment-wise scores were compared using paired samples t tests. RESULTS: The scan time for the clinical and deep learning–based image reconstruction sequences were 7:26 minutes and 5:23 minutes respectively. Deep learning–based image reconstruction images showed consistently higher wall signal and lumen visualization scores, with the differences being statistically significant in most vessel segments on both pre- and postcontrast images. Deep learning–based image reconstruction had lower background noise, higher image sharpness, and uniform CSF signal. Depiction of intracranial pathologies was better or similar on the deep learning–based image reconstruction. CONCLUSIONS: Our preliminary findings suggest that deep learning–based image reconstruction–optimized intracranial vessel wall imaging sequences may be helpful in achieving shorter gradient times with improved vessel wall visualization and overall image quality. These improvements may help with wider adoption of intracranial vessel wall imaging in clinical practice and should be further validated on a larger cohort. Full Article
rt Artificial Intelligence Efficacy as a Function of Trainee Interpreter Proficiency: Lessons from a Randomized Controlled Trial [RESEARCH] By www.ajnr.org Published On :: 2024-11-07T15:14:12-08:00 BACKGROUND AND PURPOSE: Recently, artificial intelligence tools have been deployed with increasing speed in educational and clinical settings. However, the use of artificial intelligence by trainees across different levels of experience has not been well-studied. This study investigates the impact of artificial intelligence assistance on the diagnostic accuracy for intracranial hemorrhage and large-vessel occlusion by medical students and resident trainees. MATERIALS AND METHODS: This prospective study was conducted between March 2023 and October 2023. Medical students and resident trainees were asked to identify intracranial hemorrhage and large-vessel occlusion in 100 noncontrast head CTs and 100 head CTAs, respectively. One group received diagnostic aid simulating artificial intelligence for intracranial hemorrhage only (n = 26); the other, for large-vessel occlusion only (n = 28). Primary outcomes included accuracy, sensitivity, and specificity for intracranial hemorrhage/large-vessel occlusion detection without and with aid. Study interpretation time was a secondary outcome. Individual responses were pooled and analyzed with the t test; differences in continuous variables were assessed with ANOVA. RESULTS: Forty-eight participants completed the study, generating 10,779 intracranial hemorrhage or large-vessel occlusion interpretations. With diagnostic aid, medical student accuracy improved 11.0 points (P < .001) and resident trainee accuracy showed no significant change. Intracranial hemorrhage interpretation time increased with diagnostic aid for both groups (P < .001), while large-vessel occlusion interpretation time decreased for medical students (P < .001). Despite worse performance in the detection of the smallest-versus-largest hemorrhages at baseline, medical students were not more likely to accept a true-positive artificial intelligence result for these more difficult tasks. Both groups were considerably less accurate when disagreeing with the artificial intelligence or when supplied with an incorrect artificial intelligence result. CONCLUSIONS: This study demonstrated greater improvement in diagnostic accuracy with artificial intelligence for medical students compared with resident trainees. However, medical students were less likely than resident trainees to overrule incorrect artificial intelligence interpretations and were less accurate, even with diagnostic aid, than the artificial intelligence was by itself. Full Article
rt The diagnostic odyssey of a patient with dihydropyrimidinase deficiency: a case report and review of the literature [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Dihydropyrimidinase (DHP) deficiency is an autosomal recessive metabolic disorder caused by biallelic pathogenic variants of DPYS. Patients with DHP deficiency exhibit a broad spectrum of phenotypes, ranging from severe neurological and gastrointestinal involvement to cases with no apparent symptoms. The biochemical diagnosis of DHP deficiency is based on the detection of a significant amount of dihydropyrimidines in urine, plasma, and cerebrospinal fluid samples. Molecular genetic testing, specifically the identification of biallelic pathogenic variants in DPYS, has proven instrumental in confirming the diagnosis and facilitating family studies. This case study documents the diagnostic journey of an 18-yr-old patient with DHP deficiency, highlighting features at the severe end of the clinical spectrum. Notably, our patient exhibited previously unreported skeletal features that positively responded to bisphosphonate treatment, contributing valuable insights to the clinical characterization of DHP deficiency. Additionally, a novel DPYS variant was identified and confirmed pathogenicity through metabolic testing, further expanding the variant spectrum of the gene. Our case emphasizes the importance of a comprehensive diagnostic approach using genetic sequencing and metabolic testing for accurate diagnosis. Full Article
rt PD-L1+ diffuse large B-cell lymphoma with extremely high mutational burden and microsatellite instability due to acquired PMS2 mutation [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 We present a unique case of a single patient presenting with two mutationally distinct, PD-L1+ diffuse large B-cell lymphomas (DLBCLs). One of these DLBCLs demonstrated exceptionally high mutational burden (eight disease-associated variants and 41 variants of undetermined significance) with microsatellite instability (MSI) and an acquired PMS2 mutation with loss of PMS2 protein expression, detected postchemotherapy. This report, while highlighting the extent of possible tumor heterogeneity across separate clonal expansions as well as possible syndromic B-cell neoplasia, supports the notion that, although rare, PD-L1 expression and associated states permissive of high mutational burden (such as mismatch repair gene loss of function/MSI) should be more routinely considered in DLBCLs. Appropriate testing may be predictive of outcome and inform the utility of targeted therapy in these genetically diverse and historically treatment-refractory malignancies. Full Article
rt Common clonal origin of three distinct hematopoietic neoplasms in a single patient: B-cell lymphoma, T-cell lymphoma, and polycythemia vera [RESEARCH ARTICLE] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 The potential for more than one distinct hematolymphoid neoplasm to arise from a common mutated stem or precursor cell has been proposed based on findings in primary human malignancies. Particularly, angioimmunoblastic T-cell lymphoma (AITL), which shares a somatic mutation profile in common with other hematopoietic malignancies, has been reported to occur alongside myeloid neoplasms or clonal B-cell proliferations, with identical mutations occurring in more than one cell lineage. Here we report such a case of an elderly woman who was diagnosed over a period of 8 years with diffuse large B-cell lymphoma, polycythemia vera, and AITL, each harboring identical somatic mutations in multiple genes. Overall, at least five identical nucleotide mutations were shared across multiple specimens, with two identical mutations co-occurring at variable variant allele frequencies in all three specimen types. These findings lend credence to the theory that a common mutated stem cell could give rise to multiple neoplasms through parallel hematopoietic differentiation pathways. Full Article
rt Deep molecular tracking over the 12-yr development of endometrial cancer from hyperplasia in a single patient [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Although the progressive histologic steps leading to endometrial cancer (EndoCA), the most common female reproductive tract malignancy, from endometrial hyperplasia are well-established, the molecular changes accompanying this malignant transformation in a single patient have never been described. We had the unique opportunity to investigate the paired histologic and molecular features associated with the 12-yr development of EndoCA in a postmenopausal female who could not undergo hysterectomy and instead underwent progesterone treatment. Using a specially designed 58-gene next-generation sequencing panel, we analyzed a total of 10 sequential biopsy samples collected over this time frame. A total of eight pathogenic/likely pathogenic mutations in seven genes, APC, ARID1A, CTNNB1, CDKN2A, KRAS, PTEN, and TP53, were identified. A PTEN nonsense mutation p.W111* was present in all samples analyzed except histologically normal endometrium. Apart from this PTEN mutation, the only other recurrent mutation was KRAS G12D, which was present in six biopsy samplings, including histologically normal tissue obtained at the patient's first visit but not detectable in the cancer. The PTEN p.W111* mutant allele fractions were lowest in benign, inactive endometrial glands (0.7%), highest in adenocarcinoma (36.9%), and, notably, were always markedly reduced following progesterone treatment. To our knowledge, this report provides the first molecular characterization of EndoCA development in a single patient. A single PTEN mutation was present throughout the 12 years of cancer development. Importantly, and with potential significance toward medical and nonsurgical management of EndoCA, progesterone treatments were consistently noted to markedly decrease PTEN mutant allele fractions to precancerous levels. Full Article
rt Pazopanib elicits remarkable response in metastatic porocarcinoma: a functional precision medicine approach [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Metastatic porocarcinomas (PCs) are vanishingly rare, highly aggressive skin adnexal tumors with mortality rates exceeding 70%. Their rarity has precluded the understanding of their disease pathogenesis, let alone the conduct of clinical trials to evaluate treatment strategies. There are no effective agents for unresectable PCs. Here, we successfully demonstrate how functional precision medicine was implemented in the clinic for a metastatic PC with no known systemic treatment options. Comprehensive genomic profiling of the tumor specimen did not yield any actionable genomic aberrations. However, ex vivo drug testing predicted pazopanib efficacy, and indeed, administration of pazopanib elicited remarkable clinicoradiological response. Pazopanib and its class of drugs should be evaluated for efficacy in other cases of PC, and the rationale for efficacy should be determined when PC tumor models become available. A functional precision medicine approach could be useful to derive effective treatment options for rare cancers. Full Article
rt ITPR1-associated spinocerebellar ataxia with craniofacial features--additional evidence for germline mosaicism [RESEARCH ARTICLE] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Inositol 1,4,5-triphosphate receptor type 1 (ITPR1) is an endoplasmic reticulum–bound intracellular inositol triphosphate receptor involved in the regulation of intracellular calcium. Pathogenic variants in ITPR1 are associated with spinocerebellar ataxia (SCA) types 15/16 and 29 and have recently been implicated in a facial microsomia syndrome. In this report, we present a family with three affected individuals found to have a heterozygous missense c.800C > T (predicted p.Thr267Met) who present clinically with a SCA29-like syndrome. All three individuals presented with varying degrees of ataxia, developmental delay, and apparent intellectual disability, as well as craniofacial involvement—an uncommon finding in patients with SCA29. The variant was identified using clinical exome sequencing and validated with Sanger sequencing. It is presumed to be inherited via parental germline mosaicism. We present our findings to provide additional evidence for germline mosaic inheritance of SCA29, as well as to expand the clinical phenotype of the syndrome. Full Article
rt Prostate cancer patient stratification by molecular signatures in the Veterans Precision Oncology Data Commons [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Veterans are at an increased risk for prostate cancer, a disease with extraordinary clinical and molecular heterogeneity, compared with the general population. However, little is known about the underlying molecular heterogeneity within the veteran population and its impact on patient management and treatment. Using clinical and targeted tumor sequencing data from the National Veterans Affairs health system, we conducted a retrospective cohort study on 45 patients with advanced prostate cancer in the Veterans Precision Oncology Data Commons (VPODC), most of whom were metastatic castration-resistant. We characterized the mutational burden in this cohort and conducted unsupervised clustering analysis to stratify patients by molecular alterations. Veterans with prostate cancer exhibited a mutational landscape broadly similar to prior studies, including KMT2A and NOTCH1 mutations associated with neuroendocrine prostate cancer phenotype, previously reported to be enriched in veterans. We also identified several potential novel mutations in PTEN, MSH6, VHL, SMO, and ABL1. Hierarchical clustering analysis revealed two subgroups containing therapeutically targetable molecular features with novel mutational signatures distinct from those reported in the Catalogue of Somatic Mutations in Cancer database. The clustering approach presented in this study can potentially be used to clinically stratify patients based on their distinct mutational profiles and identify actionable somatic mutations for precision oncology. Full Article
rt Novel pathogenic UQCRC2 variants in a female with normal neurodevelopment [RESEARCH REPORT] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 Electron transport chain (ETC) disorders are a group of rare, multisystem diseases caused by impaired oxidative phosphorylation and energy production. Deficiencies in complex III (CIII), also known as ubiquinol–cytochrome c reductase, are particularly rare in humans. Ubiquinol–cytochrome c reductase core protein 2 (UQCRC2) encodes a subunit of CIII that plays a crucial role in dimerization. Several pathogenic UQCRC2 variants have been identified in patients presenting with metabolic abnormalities that include lactic acidosis, hyperammonemia, hypoglycemia, and organic aciduria. Almost all previously reported UQCRC2-deficient patients exhibited neurodevelopmental involvement, including developmental delays and structural brain anomalies. Here, we describe a girl who presented at 3 yr of age with lactic acidosis, hyperammonemia, and hypoglycemia but has not shown any evidence of neurodevelopmental dysfunction by age 15. Whole-exome sequencing revealed compound heterozygosity for two novel variants in UQCRC2: c.1189G>A; p.Gly397Arg and c.437T>C; p.Phe146Ser. Here, we discuss the patient's clinical presentation and the likely pathogenicity of these two missense variants. Full Article
rt De novo TRPM3 missense variant associated with neurodevelopmental delay and manifestations of cerebral palsy [RESEARCH ARTICLE] By molecularcasestudies.cshlp.org Published On :: 2024-01-10T08:13:38-08:00 We identified a de novo heterozygous transient receptor potential cation channel subfamily M (melastatin) member 3 (TRPM3) missense variant, p.(Asn1126Asp), in a patient with developmental delay and manifestations of cerebral palsy (CP) using phenotype-driven prioritization analysis of whole-genome sequencing data with Exomiser. The variant is localized in the functionally important ion transport domain of the TRPM3 protein and predicted to impact the protein structure. Our report adds TRPM3 to the list of Mendelian disease–associated genes that can be associated with CP and provides further evidence for the pathogenicity of the variant p.(Asn1126Asp). Full Article