Medicine in Drug Discovery最新文献

{"title":"The distribution of Hypocretin/Orexin receptor mRNA in the mouse and human brain","authors":"Sanjida Mir ,&nbsp;Ryan J. Keenan ,&nbsp;Romke Bron ,&nbsp;Cameron J. Nowell ,&nbsp;Catriona McLean ,&nbsp;Leah C. Beauchamp ,&nbsp;Laura J. Vella ,&nbsp;Brian Dean ,&nbsp;Daniel Hoyer ,&nbsp;Laura H. Jacobson","doi":"10.1016/j.medidd.2024.100202","DOIUrl":"10.1016/j.medidd.2024.100202","url":null,"abstract":"<div><div>Hypocretin (<em>Hcrtr, HCRTR</em>) / orexin (OX) receptors modulate a range of neurobiological functions and are drug targets for several disorders. Mapping the distribution of receptors in the brain can inform their function and guide targeting of specific disorders. Although studied in rodents, orexin receptor distribution has remained relatively unexplored in humans, and thus there is also a paucity of comparative anatomy. The aim of this study was therefore to map the distribution of hypocretin/orexin receptor mRNA in selected regions of the mouse and human brain by non-radioactive in situ hybridization (ISH) using digoxigenin (DIG)-labelled cRNA anti-sense probes. Data revealed both distinct and overlapping patterns of distributions of <em>Hcrtr1/HCRTR1</em> and <em>Hcrtr2/HCRTR2</em> mRNA suggesting that the functions of the orexin system are mediated differently by each receptor. In the mouse brain, the highest expression of <em>Hcrtr1</em> mRNA was in the locus coeruleus (LC) whereas <em>Hcrtr2</em> mRNA was most abundant in the lateral hypothalamus (LH). The human caudate nuclei showed significant expression of both <em>HCRTR1</em> and <em>HCRTR2</em> mRNA, whereas the mouse predominantly expressed <em>Hcrtr2</em> mRNA. The noradrenergic neurons of the human LC showed high signals for both <em>HCRTR1</em> (71.7%) and <em>HCRTR2</em> (81.5%) mRNA. Expression of <em>HCRTR2</em> mRNA in non-noradrenergic human LC cells was also notable. The distribution pattern in mouse and human brains is consistent with the involvement of the orexin system in arousal and the sleep/wake cycle in both species, however, variations in receptor subtype expression profiles suggests that species differences in responses to orexin receptor ligands may be expected.</div></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100202"},"PeriodicalIF":0.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural features of arrestin-mediated GPCR signaling","authors":"Wenqin Xie ,&nbsp;Jinglin Lai ,&nbsp;Hongmin Cai ,&nbsp;H. Eric Xu ,&nbsp;Wanchao Yin","doi":"10.1016/j.medidd.2024.100201","DOIUrl":"10.1016/j.medidd.2024.100201","url":null,"abstract":"<div><div>G protein-coupled receptors (GPCRs) constitute a diverse and extensive array of cell surface receptors, rendering them essential targets for drugs aimed at various human diseases. Responding to a range of extracellular or intracellular cues, GPCRs regulate cellular signaling through downstream transducers such as heterotrimer G proteins, GPCR kinases (GRKs), and arrestins. The wealth of 3D structures available for GPCRs and their signaling complexes significantly enhances our understanding of GPCR biology and expedites the development of structure-based drug discovery methods aimed at GPCR signaling. While the structural exploration of GPCR-G protein complexes has advanced, recent years have seen substantial breakthroughs in unraveling the mechanism behind arrestin-mediated GPCR signaling. This review aims to explore emerging insights into arrestin activation and its interaction with GPCRs, shedding light on the various ways GPCRs engage with arrestins both conservatively and diversely. Additionally, we summarize recent endeavors focused on designing functionally selective (’biased’) ligands targeting GPCRs, with desired effects on/off arrestin signaling. Our goal with this review is to spotlight studies investigating the structural aspects of GPCR activation and arrestin-binding modes, with a specific emphasis on arrestin-mediated GPCR signaling.</div></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100201"},"PeriodicalIF":0.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting BCL-2 family proteins using BH3 mimetic drugs for cancer therapy: A systematic review of randomized clinical trials","authors":"Fatimah Alharbi,&nbsp;Eyad Almanifi,&nbsp;Md. Ashrafuzzaman","doi":"10.1016/j.medidd.2024.100199","DOIUrl":"10.1016/j.medidd.2024.100199","url":null,"abstract":"<div><div>Apoptosis plays a significant role in both carcinogenesis and cancer treatment. Apoptotic dysfunction may allow cancer cells to survive. Overexpression of anti-apoptotic B cell lymphoma-2 (BCL-2) family protein members is predicted to majorly contribute to apoptotic dysfunction. Therefore, targeting proteins in cancer has been of interest to scientists and drug developers. The most successful method to regulate apoptosis in cancer cells so far has been found in the development of BH3-mimetic drugs that may work towards downregulating anti-apoptotic BCL-2 protein functions. Clinical trials have dealt with a few molecules that mimic the function of BH3-only proteins and therefore inhibit their anti-apoptotic functions. Currently, this approach is one of the most promising and effective strategies for cancer treatment. Since the family has more than fifteen protein members, this review will focus on three members that have garnered interest as therapeutic targets: Bcl-2, Bcl-X_L, and myeloid cell leukaemia 1 (Mcl-1), all are anti-apoptosis proteins. In addition, it covers the major functions of Bcl-2, Bcl-X_L, and MCL-1, their implication in malignancy, as well as their pharmacologic inhibitors. The Food and Drug Administration has approved the first BH-3 mimetic, venetoclax, an oral Bcl-2 inhibitor shown to treat chronic lymphocytic leukemia. This systematic review of clinical trials investigates the efficacy and clinical relevance of BCL-2 family protein inhibitors in managing malignancies.</div></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100199"},"PeriodicalIF":0.0,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacological effects of dragon’s blood from Dranaena cochinchinensis (Lour.) S.C. Chen and its application in cardiovascular diseases","authors":"Hui-juan Zhang ,&nbsp;Kai-xuan Lin ,&nbsp;Li-dan Fu ,&nbsp;Francis Chanda ,&nbsp;Abdallah Iddy Chaurembo ,&nbsp;Jian-yuan Huang ,&nbsp;Yun-jing Xu ,&nbsp;Chi Shu ,&nbsp;Ke Yang ,&nbsp;Na Xing ,&nbsp;Wei-bo Dai ,&nbsp;Han-bin Lin","doi":"10.1016/j.medidd.2024.100200","DOIUrl":"10.1016/j.medidd.2024.100200","url":null,"abstract":"<div><div>Dragon’s blood (<em>Resina Draconis</em>) is the red resin of <em>Dracaena</em> spp, which has a variety of biological activities and pharmacological effects, including anti-thrombotic, anti-inflammatory, anti-bacterial, analgesic, anti-oxidant, anti-tumor, and immunosuppressive. In China, the main source of dragon’s blood is <em>Dranaena Cochinchinensis</em> (Lour.) S.C.Chen. A wide array of studies have speculated that the dragon’s blood derived from <em>Dranaena Cochinchinensis</em> (Lour.) S.C.Chen possesses cardiovascular protective effects. It has been reported that Chinese dragon’s blood can potentially alleviate and treat conditions such as coronary heart disease, myocardial infarction, and myocardial ischemia–reperfusion through its anti-inflammatory and antioxidant properties, which have not been systematically stated in previous reviews. Moreover, the precise underlying pharmacological mechanisms through which the Chinese dragon’s blood exhibits cardioprotective effects are not fully understood. Therefore, this article discusses the pharmacological action and biomolecular mechanism of dragon’s blood from <em>Dranaena Cochinchinensis</em> (Lour.) S.C.Chen and how it prevents and protects against cardiovascular diseases. The review article concludes with prospects for further application of dragon’s blood in respect to cardiovascular diseases.</div></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100200"},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coronavirus spike protein-based vaccines. Vaccine delivery systems","authors":"Akmal M. Asrorov ,&nbsp;Mirzakamol S. Ayubov ,&nbsp;Bin Tu ,&nbsp;Mingjie Shi ,&nbsp;Huiyuan Wang ,&nbsp;Sharafitdin Mirzaakhmedov ,&nbsp;Amit Kumar Nayak ,&nbsp;Ibrokhim Y. Abdurakhmonov ,&nbsp;Yongzhuo Huang","doi":"10.1016/j.medidd.2024.100198","DOIUrl":"10.1016/j.medidd.2024.100198","url":null,"abstract":"<div><p>Spike protein has been established as one of the molecules playing a pivotal role in coronavirus infection. On its bases, several vaccines have been developed, passed preclinical and clinical stages, and reached medical practice at the early stages of the pandemic. It was found efficient enough to induce various types of immunoglobulins. However, the missense mutations made it necessary to develop new sequences with adjuvants to enhance the efficacy against a broad spectrum of SARS-CoV-2 and newly emerging variants. Some attempts were carried out to improve the vaccine efficiency by loading it into a delivery system, which caused a prolongation effect. In this paper, we reviewed data around spike protein-based vaccines in terms of their efficacy, which was analyzed based on enhanced quantities/titers of immunoglobulins/neutralizing antibodies. Our search on the PubMed database using ‘spike protein-based coronavirus vaccines’ keywords showed over 150 publications that were further filtered based on their relevance. Further, we added other relevant papers to support the expressed ideas. We compared the effects of various vaccines of different origins in clinical studies and animal experiments where relevant. The efficacy of adjuvants has been reviewed as a separate section. In several cases, we explained the significance of the spike protein trimeric structure. We also explained the essential role of mutation while developing protein vaccines. The contributions of adjuvants in inducing immune responses have been separated into one section. The outcomes of clinical studies were highlighted to prove their efficacies.</p></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100198"},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S259009862400023X/pdfft?md5=1848354a80eb802b2c91988187479acd&pid=1-s2.0-S259009862400023X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking the therapeutic capabilities of GPCR in the treatment of ischemic stroke: A translational literature","authors":"Girish B S Pharm.D,&nbsp;Nikitha B S Pharm.D,&nbsp;Roopa K Pharm.D,&nbsp;Meghana C S Pharm.D,&nbsp;Srinivasan R M.Pharm, PhD","doi":"10.1016/j.medidd.2024.100197","DOIUrl":"10.1016/j.medidd.2024.100197","url":null,"abstract":"<div><p>GPCRs are a class of membrane proteins that are essential to signal transduction, and this is a vital process in many different physiologies. The significant mortality rate and widespread occurrence of stroke highlight the need to accelerate the research to develop viable treatment agents. A promising prospect for the development of new treatment approaches is the increasing comprehension of the pathophysiology of stroke and the crucial roles played by GPCRs. Because of the blood clot, the glial cells’ vascular supply is abruptly cut off, which sets off a series of events that include inflammation and neuronal damage and ultimately lead to cell death. Numerous therapeutic treatments, including thrombolytic agents like tissue plasminogen activator and urokinase, have been discovered as potential neuroprotective medicines; however, their use is restricted because of the modest therapeutic window. Accepting that GPCRs are the pertinent factors in ischemic stroke, we explore the potential medicinal promise of GPCR-targeted treatments and the shortcomings that ought to be resolved in order to translate these discoveries to clinical cases.</p></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"24 ","pages":"Article 100197"},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590098624000228/pdfft?md5=7ea1babb292d6f267fc89fefc770927a&pid=1-s2.0-S2590098624000228-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The psychological distress associated with type 2 diabetes mellitus represents an unmet need for drug discovery","authors":"S. Akshatha,&nbsp;Uday B. Nayak","doi":"10.1016/j.medidd.2024.100196","DOIUrl":"10.1016/j.medidd.2024.100196","url":null,"abstract":"<div><p>Non-adherence to antidiabetic medication remains the major factor contributing to poor clinical outcomes among patients with type 2 diabetes mellitus (T2DM). This study was designed to investigate the cross-sectional association between psychological distress and medication adherence in T2DM patients. Participants were 100 adults with T2DM from a teaching hospital in South India. Psychological distress was assessed using the 12-item General Health Questionnaire (GHQ-12) and the 8-item Morisky Medication Adherence Scale (MMAS-8) was used to assess medication adherence. This study demonstrated that a high proportion of patients (70 %) with T2DM experience psychological distress. Higher self-reported distress was the strongest independent predictor of medication non-adherence (β = −0.1145; P=0.0002). The study highlights that psychological distress in T2DM patients meets important drug discovery criteria such as unmet medical need, disease prevalence, and success probability. Understanding the biological mechanisms that underpin psychological distress would aid in the development of mechanism-based therapies. Better integration of medical and psychosocial treatments in general medical practice may be important to improve treatment adherence and reduce disparities in chronic disease care.</p></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"23 ","pages":"Article 100196"},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590098624000216/pdfft?md5=84ca60766df327a2a797407c7cac8d77&pid=1-s2.0-S2590098624000216-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent developments in receptor tyrosine kinase inhibitors: A promising mainstay in targeted cancer therapy","authors":"Rahul Kumar ,&nbsp;Harsh Goel ,&nbsp;Raghu Solanki ,&nbsp;Laxminarayan Rawat ,&nbsp;Saba Tabasum ,&nbsp;Pranay Tanwar ,&nbsp;Soumitro Pal ,&nbsp;Akash Sabarwal","doi":"10.1016/j.medidd.2024.100195","DOIUrl":"https://doi.org/10.1016/j.medidd.2024.100195","url":null,"abstract":"<div><p>During the past two decades, significant advances have been made in the discovery and development of targeted inhibitors aimed at improving the survival rates of cancer patients. Among the multitude of potential therapeutic targets identified thus far, Receptor Tyrosine Kinases (RTKs) are of particular importance. Dysregulation of RTKs has been implicated in numerous human diseases, particularly cancer, where aberrant signaling pathways contribute to disease progression. RTKs have a profound impact on intra and intercellular communication, and they also facilitate post-translational modifications, notably phosphorylation, which intricately regulates a multitude of cellular processes. Prolonged phosphorylation or the disruption of kinase regulation may lead to significant alterations in cell signaling. The emergence of small molecule kinase inhibitors has revolutionized cancer therapy by offering a targeted and strategic approach that surpasses the efficacy of traditional chemotherapeutic drugs. Over the last two decades, a plethora of targeted inhibitors have been identified or engineered and have undergone clinical evaluation to enhance the survival rates of cancer patients. In this review, we have compared the expression of different RTKs, including Met, KDR/VEGFR2, EGFR, BRAF, BCR, and ALK across different cancer types in TCGA samples. Additionally, we have summarized the recent development of small molecule inhibitors and their potential in treating various malignancies. Lastly, we have discussed the mechanisms of acquired therapeutic resistance with a focus on kinase inhibitors in EGFR mutant and ALK-rearranged non-small cell lung cancer and BCR-ABL positive chronic myeloid leukemia.</p></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"23 ","pages":"Article 100195"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590098624000204/pdfft?md5=90e864d311e6f6cbf02a7d7750d65e67&pid=1-s2.0-S2590098624000204-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repurposing nitrofurantoin as a stimulant of fibroblast extracellular matrix repair for the treatment of emphysema","authors":"Mathew N. Leslie ,&nbsp;Zara Sheikh ,&nbsp;Dikaia Xenaki ,&nbsp;Brian G. Oliver ,&nbsp;Paul M. Young ,&nbsp;Daniela Traini ,&nbsp;Hui Xin Ong","doi":"10.1016/j.medidd.2024.100194","DOIUrl":"https://doi.org/10.1016/j.medidd.2024.100194","url":null,"abstract":"<div><p>Emphysema is a respiratory disease that causes the progressive loss of lung extracellular matrix (ECM) organisation, subsequently undermining lung integrity and reducing lung function. Fibroblasts must constantly repair damage to the lungs to preserve lung health, however, fibroblast ECM repair is reduced during emphysema, causing ECM damage to outweigh fibroblast ECM maintenance. Current treatments for emphysema fail to address the root causes of emphysematous progression, highlighting the need for novel methods of treating emphysema. Nitrofurantoin is a broad-spectrum antibiotic indicated for the treatment of urinary tract infections that also displays potential as a novel avenue of emphysema treatment. Nitrofurantoin is known to potentially cause fibrotic effects that could be repurposed to increase fibroblast repair and outweigh the progressive ECM damage of the emphysematous lung. Therefore, this study examined the effects of nitrofurantoin treatment on primary human lung fibroblasts derived from emphysema patients to determine if the drug holds potential as a novel treatment for emphysema. Nitrofurantoin was shown to stimulate migration and alter fibroblast morphology by increasing cell area and reducing roundness, suggesting that it could induce an ECM-repair primed phenotype in fibroblasts. Interestingly, nitrofurantoin treatment did not alter collagen-IV, perlecan, periostin or tenascin-C deposition, though fibronectin deposition was significantly upregulated at a higher dosage (20 μg/mL). This study highlighted the nitrofurantoin induced changes to fibroblast motility and morphology that facilitate ECM repair. Thus, nitrofurantoin induced pulmonary fibrosis could be caused by a change in cell phenotype that subsequently upregulates ECM repair, indicating its potential as a treatment for emphysema.</p></div>","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"23 ","pages":"Article 100194"},"PeriodicalIF":0.0,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590098624000198/pdfft?md5=e01ff09770a2b573a87f8957214ffc30&pid=1-s2.0-S2590098624000198-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141478971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the kinetic features of orexin receptor antagonists at orexin receptors, transduction systems and receptor binding","authors":"Daniel Hoyer ,&nbsp;Laura H. Jacobson","doi":"10.1016/j.medidd.2024.100190","DOIUrl":"10.1016/j.medidd.2024.100190","url":null,"abstract":"<div><p>Orexin receptor antagonists are on the market or under development for the treatment of insomnia and a number of other neuropsychiatric disorders. Currently, suvorexant, lemborexant and daridorexant, three dual orexin receptor antagonists (DORAs) have received market approval by regulatory authorities in the USA, Australia, Europe and/or Japan for the treatment of insomnia. More DORAs and Selective Orexin Receptor Antagonists (SORAs) in addition to orexin receptor agonists are in various stages of preclinical and clinical development: for instance, 1SORAs (selective orexin 1 receptor antagonists) are being developed for the treatment of anxiety, panic, eating disorders, whereas 2SORAs (selective orexin 2 receptor antagonists) are in late clinical stage for the treatment of insomnia and insomnia-related depression. On the other hand, selective orexin 2 receptor agonists are in clinical trials for the treatment of narcolepsy with (NT1) or without cataplexy (NT2) and other aspects of extreme day time sleepiness.</p><p>Traditionally, the medium to high throughput screening procedures used to screen / characterize orexin receptor antagonists or agonists (and for that matter ligands acting on a variety of potential drug targets), frequently ignore two aspects of new drugs candidates: possible functional selectivity (biased agonism or antagonism) and intrinsic receptor-ligand kinetic properties (i.e. association and dissociation features at the target level), since most screening protocols are conducted under short incubation time conditions with usually a single functional readout. Here, we report on strategies to characterise orexin receptor ligands (agonists or antagonists) in radioligand binding and calcium mobilization assays (e.g. using the FLIPR ® /Fluorescent Imaging Plate Reader assay) and for a few select DORAs, on ERK activation. We studied clinically effective and/or tool orexin receptor antagonists (almorexant, suvorexant, filorexant, SB-649868, MK1064…), which have been or are being evaluated in clinical trials or are on the market, in these signalling pathways with an emphasis on kinetics. Thus, we investigated calcium mobilization and pERK elevation triggered by orexin A (OXA) in HEK293 cells stably transfected with human OX₁R or OX₂R. We confirmed that the ligands behave as antagonists in either assay. Most ligands do not show significant functional selectivity between the two pathways, except MK-1064, which inhibits calcium mobilization about 35 times more potently than ERK phosphorylation. We also estimated the kinetic properties of the antagonists in radioligand binding, calcium mobilization and pERK assays. The results of radioligand binding and calcium mobilization assays indicate consistently that several of the tested antagonists bind to/dissociate from either or the two orexin receptors very slowly, with equilibrium reached only after several hours. Thus, SB-649868 is a very slow binder at the OX<su","PeriodicalId":33528,"journal":{"name":"Medicine in Drug Discovery","volume":"22 ","pages":"Article 100190"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590098624000150/pdfft?md5=b1feee5aa6e995c5dbe01943f9c05654&pid=1-s2.0-S2590098624000150-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141136060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}