British Journal of Pharmacology最新文献

Background and purpose: Mavacamten (MAVA) is a novel small molecule inhibitor of cardiac myosin, mitigating cardiomyocyte hypercontractility in patients with hypertrophic obstructive cardiomyopathy (HOCM). Despite its recent approval for clinical use, the transcriptional and functional impacts of MAVA remain not well understood. In this study we investigate the effects of MAVA across diverse cardiac models, including healthy female porcine cardiomyocytes and myocardial slices, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), cardiac organoids and living myocardial slices (LMSs) derived from patients with HOCM.

Experimental approach: Long-term LMS culture facilitated continuous force measurements, while SarcTrack and MUSCLEMOTION analyses were used to evaluate contractility in cardiomyocytes and cardiac organoids. Transcriptome profiling of MAVA-treated HOCM hiPSC-CMs and HOCM LMSs allowed in-depth examination of gene expression signatures in response to MAVA treatment.

Key results: Across all models tested, MAVA demonstrated robust force inhibition. In primary disease models, MAVA showed little effect on time to peak or relaxation times and even reduced contraction and relaxation velocities. By contrast, in engineered human HOCM models, MAVA accelerated both contraction and relaxation, suggesting potential model-specific effects. Transcriptome analyses revealed that MAVA treatment not only influenced contraction regulation but also significantly altered cytoskeleton organization, muscle stretch response, and metabolic pathways. Notably, in LMSs derived from three HOCM patients, MAVA treatment up-regulated myosin binding protein H (MyBPH) expression, suggesting that MyBPH may also be involved in contraction regulation.

Conclusion and implications: These data suggest that MAVA not only inhibits force within the sarcomere but also influences transcriptional pathways in model-specific manner.

Background and purpose: Hydnocarpin D (HD) is a flavonolignan compound isolated from Hydnocarpus wightiana. This study was to investigate the effect of HD on ovarian cancer mediated by the regulation of SERPINE1.

Experimental approach: Cytotoxicity was assessed by the MTT assay. Cell migration and invasion were examined using wound healing and Boyden chamber assays. An orthotopic xenograft model was constructed to determine the inhibitory effect of HD on ovarian cancer in vivo. Differential gene expression was screened by RNA sequencing. A 3'-UTR luciferase assay was performed to confirm the regulatory effect of microRNA-145-5p on SERPINE1. Small interfering RNA and microRNA mimics/inhibitors were introduced to elucidate the mechanism.

Key results: HD inhibited the migration and invasion of SKOV3 and OVCAR4 cells without showing cytotoxic effects. HD inhibited the growth and metastasis of ovarian cancer in vivo. RNA-sequencing analysis suggested that HD suppressed metastasis by inhibiting SERPINE1 expression. Free uPA, which is not bound to PAI-1 (SERPINE1), was up-regulated, whereas vitronectin, integrin αV and phosphorylated FAK, the downstream metastasis-related signalling factors for PAI-1, were down-regulated after treatment with HD. SERPINE1 inhibition attenuated the effect of HD on reducing cell migration and rhPAI-1 enhanced the effect of HD. We identified microRNA-145-5p as the post-transcriptional repressor of SERPINE1. MicroRNA-145-5p was up-regulated by HD, and its overexpression enhanced the inhibition of PAI-1 expression and migration by HD, whereas its inhibition had the opposite effect.

Conclusion and implications: We showed that HD inhibits metastasis in ovarian cancer by up-regulating microRNA-145-5p, which targets SERPINE1, inhibiting vitronectin/integrin/FAK signalling.

Background and purpose: Cellular senescence, a stress-induced cell cycle arrest state, plays a dual role in cancer. Circular RNAs (circRNAs), endogenous noncoding RNAs, regulate physiological processes and are linked to diseases including cancer. This study investigates the role and mechanism of circPTK2 in non-small cell lung cancer (NSCLC).

Experimental approach: Lentivirus-mediated knockdown or overexpression of circPTK2 were used to assess effects on proliferation and senescence. circPTK2 expression in NSCLC tissues was examined using tissue microarrays and in situ hybridization. RNA-seq identified circPTK2-regulated signalling pathways and downstream targets. Transcriptional regulation of FOXM1 by NFYA was investigated using chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. Co-immunoprecipitation (Co-IP) was conducted to assess the interaction between NFYA and MDM2, as well as NFYA ubiquitination.

Key results: circPTK2 was highly expressed in NSCLC tissues and was associated with poor prognosis. Knockdown of circPTK2 significantly inhibited cancer cell growth and enhanced cellular senescence. RNA-seq analysis identified FOXM1 as a downstream target of circPTK2. Database predictions suggested that NFYA could transcriptionally regulate FOXM1. Knockdown of circPTK2 induced NFYA degradation. circPTK2 was found to bind to the E3 ubiquitin ligase MDM2 in the cytoplasm, thereby preventing MDM2 from interacting with the transcription factor NFYA. This interaction blocked MDM2-mediated ubiquitylation and degradation of NFYA. Additionally, NFYA bound to the FOXM1 gene promoter, ultimately leading to the up-regulation of FOXM1 and suppression of cellular senescence.

Conclusions and implications: Elevated circPTK2 expression correlates with poorer survival, representing a potential therapeutic target in NSCLC.

Despite tremendous advances in new drug development over recent decades, the medical needs of an ever increasing and ageing global population are still significantly unmet. Drug repurposing (DR)—finding new therapeutic uses for existing medicinal substances and products—offers a promising strategy by potentially reducing development time, costs and risk. However, currently, significant hurdles restrict broader application of DR. This study was conducted within the European Commission funded REMEDi4ALL consortium to systematically identify and analyse the key policy obstacles perceived to be hindering the success of DR. A systematic literature review was conducted using PubMed and Embase, supplemented by grey literature searches and expert interviews within the consortium. The extracted data underwent thematic analysis. A barrier tree was developed and validated through five workshops with 80 experts from seven stakeholder groups. From 4059 hits, 192 were included for data extraction, resulting in the identification of 33 key barriers grouped into nine main themes: perception of off-patent medicines, business case for on-patent DR, business case for off-patent DR, non-industry-funded DR, ecosystem for non-profit or small and medium-sized enterprise-driven repurposing, market authorisation, exclusivity rights, health technology assessment and pricing. This comprehensive analysis provides a foundation for prioritizing the main areas for future interventions. Surprisingly, there were considerable differences in how different stakeholders perceived the importance of a number of key barriers. Such multidimensional aspects of DR barriers will need to inform future development of actionable policy recommendations to enhance the DR ecosystem and facilitate broader access to repurposed medicines.

Background and purpose: ATP-dependent activation of P2X receptors has been implicated in chronic cough. The mechanisms of ATP release in cough and how P2X-receptor engagement produces cough hypersensitivity are not clear. It is also unclear whether P2X receptor blockade could compromise the essential defensive functions of cough regulated by the vagal Aδ-fibres terminating in the extrapulmonary airways.

Experimental approach: We measured ATP release from isolated human and guinea pig airways. P2X receptor-dependent regulation of vagal afferent nerve discharge in vitro and respiratory reflexes in anaesthetised guinea pigs also were studied using the P2X blockers AF-353 and AF-454.

Key results: ATP was released continually and metabolised by human and guinea-pig airways. ATP release was augmented by mild mechanical stimulation (blocked by carbenoxolone) and hypotonic challenges (blocked by ruthenium red), dwarfing the ATP release evoked by acid or by TRPV4 activation. Epithelium removal prevented ATP release evoked by either mechanical stimulation of the airways or by hypotonic challenges. AF-454 inhibited α, β-methylene ATP evoked action potential discharge in bronchopulmonary nodose C-fibres, but was without effect on extrapulmonary Aδ-fibre excitability and did not prevent acid or mechanically induced cough responses evoked in anaesthetised guinea pigs. AF-454 and AF-353 did, however, inhibit α, β-methylene ATP evoked increases in airway cholinergic tone and changes in respiratory patterns, respectively.

Conclusions and implications: These results predict a desirable safety profile for P2X receptor blockade and identify multiple potential biomarkers that may differentiate responders from non-responders in studies evaluating P2X blockers in chronic cough patients.

Background and purpose: Osteoarthritis (OA) is the most common form of arthritis worldwide. Here, we have sought to clarify the regulatory mechanisms by which the cellular retinoic acid-binding protein 2 (Crabp2) modulated OA occurrence and to elucidate the role of the insular cortex in regulating OA and anxiety.

Experimental approach: A model of OA was established following intra-articular injection of monosodium iodoacetate in mice, and a series of assessments and behavioural experiments were conducted to investigate the pathological features of OA and anxiety-related behaviours.

Key results: RNA-sequencing analysis revealed an increased Crabp2 expression in the articular cartilage of OA mice. Using the adeno-associated virus (AAV) strategy, Crabp2 overexpression in articular cartilage was shown to exacerbate progression of OA and anxiety-related behaviours. Neural linkages from the insular cortex to the knee joints were identified using a retrograde transneuronal viral tracing technique. Hyperexcitability of glutamatergic neurons in the insular cortex of OA mice was assessed by monitoring expression of FosB and Ca²⁺-sensitive fibre photometry recordings. Activation of glutamatergic neurons in the insular cortex promoted the development of OA and anxiety-related behaviours, whereas inhibiting these neurons attenuated the pathological features of OA and anxiety phenotypes.

Conclusion and implications: Our results emphasized the role of Crabp2 in the regulation of OA and related anxiety disorders by interacting with the insular cortex. This brain area may function as a pathogenetic gene and serve as a therapeutic target in the treatment of OA and its related anxiety disorders.

Background and purpose: Myocardial fibrosis (MF), a hallmark of structural cardiac remodelling, drives disease progression across most forms of heart failure and plays a central role in heart failure with preserved ejection fraction (HFpEF). Despite its clinical relevance, effective treatments remain scarce. In preclinical models, current methods for quantifying MF fail to capture its regional heterogeneity, limiting reliable assessment of novel anti-fibrotic compounds. This study aimed to develop a whole-heart imaging and deep learning (DL)-based quantification pipeline for MF, and to validate its utility by evaluating the efficacy of a glucagon-like peptide-1 receptor (GLP-1R) agonist in a mouse model of HFpEF.

Experimental approach: By utilising fluorescent collagen-labelling dye, tissue clearing and three-dimensional light sheet fluorescence microscopy (3D LSFM), we developed a high-throughput imaging platform for MF. We established a DL framework to quantify interstitial, perivascular and replacement fibrosis, as well as hypertrophy, in 17 left ventricular (LV) segments. The antifibrotic efficacy of the GLP-1R agonist semaglutide was evaluated in the db/db UNx-ReninAAV mouse model, which exhibits diabetes, kidney failure, obesity and hypertension.

Key results: Whole-heart 3D LSFM, combined with DL, enabled micrometre-resolution mapping of MF in rodents. Using this approach, we observed that interstitial collagen content increases proportionally with cardiac hypertrophy. Chronic treatment with semaglutide reduced LV hypertrophy and perivascular fibrosis but did not affect the extent of replacement fibrosis.

Conclusions and implications: The established 3D imaging and quantification approach provides a powerful tool for evaluating the therapeutic efficacy of antifibrotic compounds and studying the pathological mechanisms underlying cardiovascular diseases.

The illicit drug 3,4-methylenedioxymethamphetamine (MDMA) has recently shown promising efficacy as an adjunct to psychotherapy for posttraumatic stress disorder (PTSD), although the underlying mechanisms are poorly defined. In this review, we contextualize the emergence of MDMA-assisted psychotherapy (MDMA-AT) within 20th century psychiatry and trace its journey from assisting with military interrogation, through prohibition and to clinical use. We outline three core domains of MDMA's subjective effects-prosocial behaviour, reduced threat perception and euphoria-and explore how each may relate to its therapeutic efficacy and abuse liability. Drawing from clinical, behavioural, and pharmacological studies, we highlight the central role of 5-HT (serotonin) in mediating the effects of MDMA, while identifying key gaps in our understanding of its mechanism of action. We also assess how preclinical models capture therapeutic-relevant processes, discuss the limitations of existing data (including sex biases and an assumed role for therapeutic alliance) and suggest strategies to unravel the neurobiological basis of MDMA's therapeutic effects. Clarifying these mechanisms will be critical for optimizing future clinical protocols, mitigating risks and guiding the clinical development of safer, mechanistically informed MDMA-like therapeutic agents.

Background and purpose: Euphorbia pekinensis (EP) is known to cause significant intestinal toxicity, primarily manifesting as severe diarrhoea, yet the precise molecular mechanisms and the active components responsible have remained elusive. This study aimed to identify the diarrheal constituents of EP and elucidate the molecular pathway through which they induce gut toxicity.

Experimental approach: The laxative effects of EP components were assessed in vivo using mouse models and diarrhoea-related indicators, with histological analysis of intestinal tissue. Ex vivo rabbit intestinal tract assays were employed to study smooth muscle contraction. The underlying mechanism was investigated using intestinal organoid fluorescence co-localization and analysis of tryptophan metabolites in mice to determine the role of enterochromaffin (EC) cells and serotonin (5-HT).

Key results: We identified specific glycosphingolipids (GSLs), including a novel hexosylceramide (HexCer), as the primary toxic agents in EP. These GSLs act as direct agonists of the TRPA1 ion channel on intestinal EC cells. This activation triggers a TRPA1-mediated influx of Ca²⁺ into EC cells, leading to excessive 5-HT release. The resulting localized overstimulation of 5-HT receptors causes aberrant intestinal smooth muscle contraction and epithelial hypersecretion, culminating in severe diarrhoea.

Conclusion and implications: This research reveals that the gut toxicity of EP is driven by a previously unrecognized GSL-TRPA1-5-HT signalling pathway in the intestinal epithelium. These findings provide a clear mechanistic basis for EP-induced diarrhoea and highlight a potential new target for managing gut toxicity.