British Journal of Pharmacology最新文献

Background and purpose: Vascular inflammation and endothelial dysfunction cause the development of atherosclerotic cardiovascular diseases including coronary artery disease (CAD). While elevated fatty acid binding protein 3 (FABP3) may be associated with the presence of cardiovascular diseases, its mechanistic effects remain unclear. This study aimed to investigate the role of FABP3 in impaired angiogenesis and the development of atherosclerosis in CAD.

Experimental approach: In total, 1104 patients were enrolled in a clinical observational study and the correlation between serum FABP3 and cardiovascular events were analysed. Another group of CAD patients and non-CAD subjects were enrolled, and their plasma FABP3 concentrations were measured. Primary cultured mononuclear cells endothelial progenitor cells and human coronary artery endothelial cells were used in vitro. Matrigel plug neovascularisation assay and the aortic ring assay were used in wild-type and apolipoprotein E-knockout mice in vivo.

Key results: Circulating FABP3 was up-regulated in the cardiovascular event-positive group and in the CAD patients. Mononuclear cells from the CAD patients presented increased expression of FABP3. FABP3 enhanced the expression of adhesion molecules, including integrin β2, integrin α4 and PSGL1 in mononuclear cells. FABP3 caused endothelial cell dysfunction through the ERK/p38/STAT1/VEGF signalling pathway. Moreover, oxLDL or TNF-α stimulations impaired endothelial cell function through FABP3-dependent signalling pathways. FABP3 also impaired in vivo angiogenesis.

Conclusion and implications: This study elucidates the clinical and pathological impact of FABP3 on atherosclerotic CAD. Future research may be necessary to evaluate whether FABP3 could be a therapeutic target, especially with regard to stable CAD.

Background and purpose: Given the recent rise in Cannabis legalisation, accessibility to Cannabis and consumption have increased during pregnancy. Therefore, there could be unintended developmental consequences. The endocannabinoid system plays a key role in fetal development and later-life energy homeostasis. We explored the long-term effects of maternal voluntary Cannabis consumption on the metabolic outcomes of a high-fat diet (HFD) in adult offspring.

Experimental approach: Pregnant mice voluntarily consumed Cannabis extract equivalent to 5 mg kg^-1 day^-1 Δ9-tetrahydrocannabinol (THC) from gestational day 1.5 until postnatal day (PD) 10. Pregnancy and pup outcomes and active maternal behaviour were recorded. Male and female offspring (PD49) were placed on a 12-week HFD or control diet; their weight gain, adiposity, glucose tolerance, insulin sensitivity, circulating hormones and pancreatic structure were measured.

Key results: Perinatal Cannabis exposure (PCE) pup weight was initially reduced but restored by PD16. PCE did not influence weight gain or metabolic characteristics of male mice on a HFD. PCE female but not male offspring on a HFD had reduced accumulation of adipose tissue and lower insulin, leptin and resistin independent of body weight. PCE females on control diet also showed altered basal insulin sensitivity likely because of increased glucagon levels in parallel with reduced islets of Langerhans size and enhanced gene expression of cannabinoid 2 receptors in white adipose tissue.

Conclusion and implications: PCE adversely affected glycaemic control in female offspring on control diet while it mitigated HFD-induced metabolic dysfunction. This raises concerns about the long-term effects of PCE on the metabolic health of offspring.

Background and purpose: Shear-induced platelet activation and aggregation (SIPA) play crucial roles in arterial thrombosis. Piezo1 is a mechanosensitive calcium channel that promotes platelet hyperactivation under pathological high-shear conditions. This study explores the function of platelet Piezo1 in SIPA and arterial thrombosis, and the inhibitory effects and mechanisms of ginsenoside Rb1 on these processes.

Experimental approach: Transgenic mice with platelet-specific Piezo1 deficiency (Piezo1^ΔPlt) were used to elucidate the role of platelet Piezo1 in SIPA and arterial thrombosis. A microfluidic channel system was employed to assess platelet aggregation, calcium influx, calpain activity, talin cleavage, integrin αIIbβ3 activation and P-selectin expression under shear flow. Cellular thermal shift assay was used to determine binding between Rb1 and Piezo1. Folts-like model in mice was used to evaluate antithrombotic effects of Rb1.

Key results: Piezo1 deficiency in platelets reduced platelet activation and aggregation induced by a high shear rate of 4000 s^-1 and attenuated arterial thrombosis induced by Folts-like mouse model. Rb1 inhibited SIPA with an IC₅₀ of 10.8 μM. Rb1 inhibited shear-induced Ca²⁺-dependent platelet activation and aggregation, as well as thrombus formation in Folts-like model in Piezo1^fl/fl mice. Rb1 significantly improved thermal stability of Piezo1 in platelets by binding to Piezo1. Treatment of Piezo1^ΔPlt mice with Rb1 did not exhibit further inhibitory effects on SIPA and thrombosis.

Conclusion and implications: Platelet Piezo1 is essential for SIPA and arterial thrombosis induced by high shear. Rb1 exerted anti-platelet and anti-thrombotic effects at high shear rates via Piezo1 channels, providing a potential candidate as antiplatelet therapeutic agent.

Background and purpose: Sphingosine-1-phosphate (S1P) receptor modulator (SRM) drugs suppress immune system function by disrupting lymphocyte trafficking, but SRMs are broadly immunosuppressive with on-target liabilities. Another strategy to modulate the immune system is to block S1P transport. This study tests the hypothesis that blockers of S1P transport (STBs) mediated by Spinster homologue 2 (Spns2) approximate the efficacy of SRMs without their adverse events.

Experimental approach: We have discovered and optimized STBs to enable investigations of S1P biology and to determine whether S1P transport is a valid drug target. The STB SLF80821178 was administered to rodents to assess its efficacy in a multiple sclerosis model and to test for toxicities associated with SRMs or Spns2-deficient mice. Further, potential biomarkers of STBs, absolute lymphocyte counts (ALCs) in blood and S1P concentrations in plasma and lymph, were measured.

Key results: SLF80821178 resembles SRMs in that it is efficacious in a standard multiple sclerosis model but does not evoke bradycardia or lung leakage, common to the SRM drug class. Also, chronic SLF80821178 administration does not affect auditory responses in adult mice despite the neurosensorial hearing defect observed in Spns2-null mice. While both SRM and STB administration decrease ALCs, the maximal effect is less with an STB (45% vs. 90%). STBs have minimal effects on S1P concentration in plasma or thoracic duct lymph.

Conclusion and implications: We found nothing to invalidate Spns2-dependent S1P transport as a drug target. Indeed, STBs could be superior to SRMs as a therapy to modulate immune system function.

Background and purpose: Kidney disease (KD) is a leading cause of mortality worldwide, affecting 〉10% of the global population. Two of the most common causes of KD are diabetes and acute kidney injury (AKI), both of which induce mitochondrial dysfunction resulting in renal proximal tubular damage/necrosis. Thus, pharmacological induction of mitochondrial biogenesis (MB) may provide a therapeutic strategy to block the onset/progression of KD. Here, we evaluated the pharmacological and potential therapeutic effects of a novel MB-inducing oxindole agent, MC16.

Experimental approach: Primary cultures of rabbit renal proximal tubule cells (RPTCs) were used to evaluate the cellular signalling and MB-inducing effects of MC16. Mice were used to determine the MB-inducing effects of MC16 in vivo, and the metabolic effects of MC16 on the renal cortical metabolome. Mouse models of AKI and diabetic kidney disease (DKD) were used to demonstrate the therapeutic potential of MC16 to ameliorate acute and diabetic nephropathy.

Key results: MC16 activated the PI3K-AKT-eNOS-FOXO1 axis and induced MB in RPTCs. MC16 induced MB and altered the renal cortical metabolome of mice. MC16 accelerated renal recovery, reduced vascular permeability, and diminished mitochondrial dysfunction following AKI. MC16 decreased diabetes-induced renal swelling, improved renal and mitochondrial function, and diminished interstitial fibrosis in DKD mouse models.

Conclusion and implications: MC16 is a novel compound that induces MB and ameliorates acute and diabetic nephropathy in mice. This study underscores that targeting MB following the onset of renal/metabolic insults may provide a therapeutic strategy to mitigate the onset and/or progression of KD.

Background and purpose: Inflammatory bowel disease (IBD) is closely associated with immune dysfunction, where nutrient-mediated metabolic flux dictates immune cell fate and function. Thiamine is a central water-soluble vitamin involved in cellular energy metabolism, and its deficiency has been reported in IBD patients. However, whether thiamine deficiency is a cause or consequence of IBD pathogenesis remains unclear. The current study aimed to reveal the immunometabolic regulation of macrophages and underlying mechanism of thiamine deficiency in colitis development.

Experimental approach: Thiamine deficiency was induced in C57BL/6 mice and bone marrow-derived macrophages (BMDMs), by administering a thiamine-deficient diet/medium together with pyrithiamine hydrobromide. The frequency of macrophage phenotypes and their intracellular metabolism were detected using flow cytometry and non-targeted metabolomics, respectively.

Key results: Thiamine deficiency aggravated ulcerative colitis in mice and promoted the infiltration of proinflammatory M1 macrophages in colonic lamina propria. Our mechanistic study revealed that thiamine deficiency impaired pyruvate dehydrogenase (PDH) activity, thereby reprogramming cellular glucose metabolism to enhance glycolysis and lactic acid accumulation in M1 macrophages. Using a well-established PDH inhibitor (CPI-613) and lactic acid dehydrogenase inhibitor (galloflavin), we further demonstrated that PDH inhibition mimics, while lactate dehydrogenase inhibition partially rescues, thiamine deficiency-induced proinflammatory macrophage infiltration and experimental colitis in mice.

Conclusion and implications: Our study provides evidence linking thiamine deficiency with proinflammatory macrophage activation and colitis aggravation, suggesting that monitoring thiamine status and adjusting thiamine intake is necessary to protect against colitis.

Background and purpose: Exposure to chronic stress and high levels of glucocorticoid hormones in adulthood has been associated with cognitive deficits and increased risk of Alzheimer's disease (AD). Dazucorilant has recently emerged as a selective glucocorticoid receptor (NR3C1) modulator, exhibiting efficacy in counteracting amyloid-β toxicity in an acute model of AD. We aim to assess the therapeutic potential of dazucorilant in reversing amyloid and tau pathologies through the inhibition of glucocorticoid receptor pathological activity, and providing additional evidence for its consideration in AD treatment.

Experimental approach: The efficacy of dazucorilant was evaluated in two transgenic mouse models of amyloid pathology. The slowly progressing J20 and the aggressively pathological 5xFAD mice. Behavioural analysis was conducted to evaluate welfare, cognitive performances and anxiety levels. The activity of the glucocorticoid receptor system, neuroinflammation, amyloid burden and tau phosphorylation were examined in hippocampi.

Key results: In both AD models, chronic treatment with dazucorilant improved working and long-term spatial memories along with the inhibition of glucocorticoid receptor-dependent pathogenic processes and the normalization of plasma glucocorticoid levels. Dazucorilant treatment also resulted in a reduction in tau hyperphosphorylation and amyloid production and aggregation. Additionally, dazucorilant seemed to mediate a specific re-localization of activated glial cells onto amyloid plaques in J20 mice, suggesting a restoration of physiological neuroinflammatory processes.

Conclusion and implications: Dazucorilant exhibited sustained disease-modifying effects in two AD models. Given that this compound has demonstrated safety and tolerability in human subjects, our results provide pre-clinical support for conducting clinical trials to evaluate its potential in AD.

Background and purpose: Endoplasmic reticulum (ER) stress is a crucial pathogenic mechanism in alcoholic liver disease (ALD). B-cell receptor-associated protein 31 (BAP31) can regulate ER homeostasis and anti-apoptosis, but the function and regulation of BAP31 in ALD are unclear. The purpose of this study is to investigate whether BAP31 deacetylation by sirtuin 2 could attenuate ER stress and apoptosis during ALD and to explore whether carnosol could alleviate ALD through the sirtuin 2/BAP31 pathway.

Experimental approach: A mouse model of ALD was established by feeding mice with alcoholic liquid chow. In vitro, AML-12 cells were stimulated with alcohol. The therapeutic efficacy of carnosol in protecting mice from ALD pathogenesis was evaluated.

Key results: Treatment with carnosol protected mice against ALD and attenuated hepatocyte ER stress and apoptosis. Carnosol up-regulated sirtuin 2 expression, and sirtuin 2knockdown abolished the protective effect of carnosol during ALD. Moreover, sirtuin 2 knockdown reduced BAP31 expression. Carnosol-mediated BAP31 up-regulation was abolished upon knockdown of sirtuin 2. Mechanistically, sirtuin 2 selectively regulates the deacetylation of BAP31 at K158.

Conclusion and implications: Taken together, the present study shows for the first time that carnosol exerts its protective efficacy through facilitating sirtuin 2-mediated deacetylation of BAP31 at K158 to attenuate hepatocyte ER stress and apoptosis during ALD. These results provide new therapeutic targets and approaches for combating chronic ALD.

Background and purpose: Phentolamine is a non-selective α-adrenoreceptor antagonist used to reverse local anaesthesia, for example, during dental procedures when a vasoconstrictor is co-applied. Phentolamine-mediated vasodilation leads to faster clearance of injected drugs. Previous electrophysiological studies hypothesized that phentolamine acts as a modulator of voltage-gated sodium channels, which could conflict with its indication as local anaesthetic reversal agent.

Experimental approach: We performed manual and high throughput patch-clamp recordings on HEK and CHO cells expressing Na_V1.7 and Na_V1.5. We investigated the effects of phentolamine on sodium channel biophysics and the additive impact of phentolamine on cells preconditioned with the local anaesthetic mexiletine. We used site-directed mutagenesis, homology modelling and drug docking to identify phentolamine's binding site. We compared the effect on sodium channels with other clinically established α-adrenoreceptor antagonists.

Key results: Phentolamine inhibits Na_V1.7 in HEK and CHO cells with an IC₅₀ value of 72 and 57 μM and Na_V1.5 in CHO cells with an IC₅₀ of 27 μM. Phentolamine enhances the tonic block induced by the local anaesthetic mexiletine. Phentolamine binds to sodium channels at the local anaesthetic receptor site. The α-adrenoreceptor antagonists alfuzosin, urapidil and phenoxybenzamine show lower potency on Na_V1.5 and Na_V1.7 in patch-clamp recordings.

Conclusions and implications: Phentolamine blocks voltage-gated sodium channels via the local anaesthetic receptor site. This may conflict with its current indication as an antidote for local anaesthetics. We propose alternative α-adrenoreceptor antagonists as possible candidates for local anaesthetic reversal because these are less potent inhibitors of both cardiac and neuronal voltage-gated sodium channels.

Background and purpose: Genetic ablation or inhibition of the cation channel TRPC6 is protective against renal, cardiac and intestinal fibrosis. However, TRPC6 expression is decreased in patients with liver diseases. Here, we explored the role of TRPC6 in liver fibrosis and the underlying mechanism.

Experimental approach: Bile duct ligation and thioacetamide gavage were used to model liver fibrosis in C57BL/6J mice. Western blotting, immunolabelling and qPCR were employed for protein and mRNA expression. Liver injury/fibrosis were assessed using serum alanine transaminase and aspartate transaminase assays, haematoxylin-eosin, Masson and Sirius red staining. Adenoviruses were used to overexpress TRPC6 and CREB1^Y134F. ChIP and dual-luciferase reporter assays were performed to test the direct inhibition of Acta2 transcription by CREB.

Key results: TRPC6 protein levels were decreased in fibrotic liver tissues from both patients and mice, with the decrease being more robust in fibrotic areas. In hepatic stellate cells (HSCs), TRPC6 ablation aggravated liver injury and fibrosis, which was alleviated by overexpressing TRPC6. In primary cultured HSCs, deletion of TRPC6 exacerbated self-activation of HSCs, which was reversed by restoration of TRPC6 expression. Mechanistically, TRPC6 suppressed HSC activation through CaMK4-mediated CREB phosphorylation. CREB directly interacted with the promoter region of Acta2 to inhibit its transcription. Expression of a constitutively active form of CREB1 (CREB1^Y134F) in HSCs attenuated BDL-induced liver injury/fibrosis in TRPC6 knockout mice.

Conclusion and implications: Deficiency of TRPC6 aggravates liver injury/fibrosis through augmentation of HSC activation. Increasing TRPC6 expression/function would be therapeutically beneficial for fibrotic liver diseases.