Doxorubicin (DOX) is a highly effective anthracycline, whose clinical application for cancer is limited by cardiotoxicity. The mechanisms underlying doxorubicin-induced toxic cardiomyopathy (DICM) involve electrophysiological remodelling with intracellular Na+ overload because of increased late INa and hyperactivation of CaMKIIδ. Increased [Na+]i contributes to CaMKIIδ activation through Na-dependent Ca2+ overload, and CaMKIIδ can further amplify late INa. We tested whether pharmacological inhibition of the late INa by either ranolazine (RAN, 10 μmol·L-1) or empagliflozin (EMPA, 1 μmol·L-1) is sufficient to attenuate DOX-mediated hyperactivation of CaMKIIδ in isolated wildtype (WT) ventricular cardiomyocytes. The contribution of reciprocal CaMKII-dependent stimulation of late INa was tested in transgenic S571A cardiomyocytes lacking the CaMKII-specific phosphorylation site S571A on NaV1.5. Functional readouts were obtained using patch-clamp technique, as well as confocal and epifluorescence microscopy. DOX acutely increased late INa in WT cardiomyocytes by twofold, which was associated with redox- and phospho-dependent activation of CaMKIIδ. Hyperactivated CaMKIIδ led to acutely impaired Ca2+ handling because of diastolic Ca2+ loss from the sarcoplasmic reticulum (SR) mediated by phosphorylation of the RyR2 at the CaMKII-specific phosphorylation site serine-2814. Pharmacological inhibition of late INa by EMPA or RAN, and genetic deletion of the CaMKII-specific phosphorylation-site serine-571 at NaV1.5 prevented DOX-related stimulation of the late INa and subsequent CaMKIIδ hyperactivation, which functionally preserved intracellular Ca handling. Inhibition of late INa protects cardiomyocytes from pathologic CaMKIIδ hyperactivation and impaired Ca2+ handling in the setting of acute DOX cardiotoxicity.
The persistence of temporomandibular disorders (TMDs), particularly myogenous, in a person with migraine can lead to exacerbated clinical outcomes and limited response to treatment. The pro-nociceptive reactive nitroxidative species, peroxynitrite, is involved in migraine mechanisms, but little is known of its role in this comorbidity. Here, we validate a model of persistent TMD comorbid with migraine in rats and dissect the role of peroxynitrite in its underlying nociceptive mechanisms, and as a novel therapeutic target. A combination of masseteric muscle injection of CFA and delayed CGRP infusion were used to model persistent myogenic-TMD comorbid with migraine, respectively. Using electrophysiological and behavioural methods, we assessed migraine-like neuronal outcomes and periorbital withdrawal thresholds to validate this approach. We measured 3-nitrotyrosine expression, as a marker of nitroxidative species, including peroxynitrite, and used the peroxynitrite decomposition catalyst, FeTPPS, and to determine the role of peroxynitrite in these comorbid mechanisms. Persistent myogenic-TMD exacerbated migraine-relevant neuronal outcomes in response to delayed CGRP, causing more prevalent and hypersensitive trigeminovascular neuronal responses to innocuous/noxious probing of dural and cutaneous-periorbital regions, demonstrating many of the signatures of 'latent sensitization'. We also observed increased expression of 3-nitrotyrosine along the trigeminal pain pathway in TMD, migraine and comorbid models and confirm that targeting peroxynitrite breakdown prevents the development of this nociceptive neuronal phenotype. Our persistent comorbid myogenic-TMD/migraine model translates to the exacerbated clinical phenotype, validating it as an approach to study mechanisms. Production of peroxynitrite along the trigeminal pain pathway contributes to the mechanisms underlying this phenotype and is a potentially novel monotherapy or combination approach.
Our previous study has highlighted the anti-inflammatory properties of gabapentin (GBP) after myocardial infarction (MI) by suppressing M1 macrophage polarization. In this study, we further dissected the important molecules involved. Ligation of the left anterior descending coronary artery was used to construct the MI mouse model. Tyrosine-protein phosphatase non-receptor type 2 (PTPN2) expression in mouse myocardial tissue macrophages was evaluated using Western blot and dual-labelling immunofluorescence. An MI mouse model with macrophage-specific knockdown of PTPN2 was constructed and treated with GBP. M1 polarization was induced by lipopolysaccharide (LPS) and IFN-γ in mouse RAW264.7 cells and bone marrow-derived macrophages. Substrates of PTPN2 were predicted and verified using co-IP and amino acid mutations. GBP alleviated cardiac dysfunction and reduced myocardial injury and macrophage M1 polarization in mice. PTPN2 expression was increased in macrophages of mice induced with MI in response to the inflammatory response, and GBP further up-regulated PTPN2. Macrophage depletion impaired the efficacy of GBP. PTPN2 knockdown enhanced M1 polarization of macrophages and exacerbated cardiac dysfunction in mice. The binding of PTPN2 to 7-dehydrocholesterol reductase (DHCR7) inhibited Y378 phosphorylation of DHCR7 and reduced the cholesterol synthesis catalysed by DHCR7. DHCR7 knockdown in macrophages reversed macrophage pro-inflammatory activation induced by PTPN2 knockdown, alleviated myocardial injury in mice and restored the efficacy of GBP. GBP enhances PTPN2 expression to inhibit tyrosine phosphorylation of DHCR7 and blocks cholesterol metabolism to limit macrophage M1 polarization and alleviate MI-induced injury.
Differential scanning fluorimetry (DSF) is a common and straightforward method to evaluate the thermal stability of proteins and has been heavily used for ligand binding characterisation as well as for screening. One class of compounds that is less typically evaluated by DSF are covalent binders. Here, we assessed the contribution of the covalent bond to protein thermal stabilisation. We evaluated selective covalent binders, as well as non-selective reactive electrophiles, against five model protein targets. To assess DSF in the context of fragment-based electrophile screening, we compared DSF measurements to covalent labelling over a subset of electrophilic fragments. We show that, in the context of selective binders, the formation of the covalent bond increases thermal stabilisation. However, it is not the covalent bond itself that stabilises the protein, because non-selective irreversible binding was typically neutral or, more often, destabilised the protein. In the context of fragment screening, the magnitude of the thermal shift tended to increase with irreversible labelling, whereas the more reactive fragments tended to destabilise the protein. Taken together, we suggest DSF as a complementary approach to triage covalent fragment hits, in which fragments that show both labelling and protein stabilisation are predicted to display molecular recognition driven binding and serve as more productive starting points for covalent ligand development.
Sodium-glucose cotransporter 2 (SGLT2) selective inhibitors (flozins) are a class of antidiabetic drugs that improve glycaemic control and are associated with cardiovascular benefits, although the underlying mechanisms remain incompletely understood. This study aimed to explore potential mechanistic effects of dapagliflozin on erythrocyte nanomechanical properties in patients with type 1 diabetes. The subject of this exploratory study is the nanomechanical properties of red blood cells (RBCs) in a pilot group of type 1 diabetes patients undergoing a thirty-day dapagliflozin treatment. Measurements were conducted on RBCs obtained from a homogeneous group of 31 adult patients with type 1 diabetes and 34 healthy control volunteers. The elastic modulus of erythrocytes was measured immediately after sample collection using the nanoindentation method with an atomic force microscopy probe. Data obtained before therapy (BT) and after therapy (AT) were compared with those from a control group of healthy volunteers. A reduction in RBC stiffness after treatment was observed, which could be related to diabetes duration. Notably, the most significant improvement occurred in patients with diabetes duration exceeding 10 years, a group at elevated cardiovascular risk. Subgroup analyses were descriptive and not powered for inferential comparisons. The observed improvement in the elastic modulus of erythrocytes following dapagliflozin therapy in patients with type 1 diabetes suggests that SGLT2 inhibitors could provide additional benefits for this patient group The results provide preliminary mechanistic insights that are consistent with the reported vascular effects of SGLT2 inhibitors.
The lungs have for a long time been recognised as having pharmacological significance as a specific organ to modulate the pharmacokinetics of endogenous substances needed to maintain homeostasis. The lungs are therefore the site of action of certain drugs that act on these homeostatic processes, resulting in systemic effects on the cardiovascular system and blood. We now understand that the lungs are also a specialised site for haematopoiesis, with integration into the body's immune system. This may have significance given the exposure of the lungs to the environment and their resident microbiota. Within this new understanding, the lungs have also been reported as a significant site of thrombopoiesis, with a reservoir of megakaryocytic precursors that give rise to a megakaryocyte and platelet population with a distinct immunophenotype compared to circulating and bone marrow-derived cells. This article reflects on the potential importance of these discoveries and pharmacological opportunities that may result to control immune/inflammatory responses via selective control of platelet activation in the context of inflammation compared to haemostasis.
New psychoactive substances (NPSs) often emerge on the illicit drug market with limited pharmacological or toxicological data. Synthetic cathinones are the second largest NPS group, often mimicking the effects of classical stimulants such as cocaine and methylenedioxymethamphetamine (MDMA). Such stimulants primarily target dopamine (DAT), norepinephrine (NET) and serotonin (SERT) transporters, with DAT selectivity being linked to abuse potential. Owing to the lack of pharmacological profiling, this study aimed to determine the potencies and structure-activity relationships (SARs) of recently emerged stimulants. Employing in vitro human transporter inhibition assay and AequoScreen® 5-HT2A receptor activity assay, the potency, transporter selectivity, DAT/SERT, DAT/NET, and NET/SERT ratios, and group-wide SARs of 58 substances were investigated. Most synthetic cathinones inhibited DAT at nanomolar concentrations, with N-pyrrolidine cathinones in combination with methylenedioxy groups-4-methylenedioxy-α-pyrrolidino-isohexanophenone (MDPiHP), 3,4-methylenedioxy PV8 (MDPEP), and 3,4-methylenedioxy pyrovalerone (MDPV)-demonstrating the highest DAT potency among all the tested stimulants. In contrast, other N-pyrrolidine cathinones, 3F-α-PHP, 3F-α-PiHP and 4F-α-PiHP, exhibited the highest DAT selectivity (DAT/SERT ratio). Chloromethcathinone (CMC) and methylmethcathinone (MMC) compounds, such as 3-CMC, exhibited a distinct amphetamine-like pharmacological uptake inhibition profile showing a comparable potency between DAT and NET. Some cathinones at high concentrations and phenethylamines in micromolar concentrations additionally activated the 5-HT2A receptor, whereas 2C-like arylcyclohexylamines primarily targeted the receptor without transporter inhibition. These results show that cathinones displayed distinct group SARs. Based on the DAT/SERT selectivity, the majority of the investigated compounds, especially N-pyrrolidine cathinones, suggest a high abuse potential.
Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that the rabbit anti‑apoptosis‑associated speck‑like protein containing a C‑terminal caspase recruitment domain (ASC) western blot data shown in Fig. 4A on p. 275 were strikingly similar to data that had already been published two years previously in Fig. 6 of an article in British Journal of Pharmacology that featured the author Xufeng Tao in common. Upon investigating the figure in question, the authors have realized that the data in Fig. 4A in the above article had inadvertently been assembled incorrectly. A revised version of Fig. 4, now showing western blot data from an alternative experiment in Fig. 4A (where the results presented are very similar to those in the originally published article) is shown on the next page. In addition, the authors have realized that the immunohistochemical data shown in Fig. 3A, highlighting the effects of emodin on MPO‑immunopositive stained regions of the pancreas, were not representative of these experiments, and a revised version of Fig. 3, showing replacement data for Fig. 3A, is also shown on the next page. The authors regret the errors that were made during the compilation of the original figures, and are grateful to the editor of Oncology Reports for allowing them the opportunity to publish this Corrigendum. Note that the errors that were made in compiling this pair of figures did not have a significant impact on the conclusions reached in this study. All the authors agree with the publication of this corrigendum; furthermore, they apologize to the readership for any inconvenience caused. [Oncology Reports 41: 270‑278, 2019; DOI: 10.3892/or.2018.6844].
Cyclin-dependent kinase 5 (CDK5), a serine/threonine kinase, involved in neuronal development and neurodegenerative diseases, regulates pain. Whereas its contribution to pain processing within nociceptors is well established, but within dorsal horn neurons remains poorly understood. We used behaviour, electrophysiology, western blot and immunohistochemistry in the trigeminal ganglion (TG) and medullary dorsal horn (MDH) of male and female rats. In naïve animals, intracisternal roscovitine (seliciclib), a CDK5 inhibitor, suppresses selectively noxious-evoked responses of MDH wide dynamic range (WDR) neurons and leaves the windup phenomenon unchanged, suggesting that CDK5 signalling within TG, but not MDH, regulates nociceptive pain. Under inflammatory conditions, roscovitine prevents the facial spontaneous pain-like behaviour, and static and dynamic secondary mechanical hypersensitivities in both sexes and the sensitization of MDH WDR neurons. But it cannot reverse them. Conversely, roscovitine reduces the neuropathic mechanical hypersensitivities. Therefore, CDK5 signalling within MDH is differently involved in chronic pain, contributing to the maintenance of neuropathic pain but only the initiation of inflammatory pain, in both sexes. Interestingly, whereas p35, p25 and pERK1/2 MDH expressions increase under inflammatory and neuropathic conditions, CDK5 expression only enhances under neuropathic ones. Finally, p35 MDH expression strongly increases following inflammatory pain, occurring in ~70-80% of neurons and also in astrocytes and microglia. MDH CDK5-p35 specifically regulates, though differently, inflammatory and neuropathic pain, making it an attractive target for the development of long-lasting analgesics in both sexes. The therapeutic indication of CDK5 inhibitors needs to consider the nature of injury.
In contrast to neurons in the central nervous system, neurons in the peripheral nervous system can regenerate axons after injury via activation of a pro-regenerative transcriptional programme. Pathogenic mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson's disease, and several small-molecule LRRK2 kinase inhibitors have been developed, with some in clinical trials. However, the physiological role of endogenous, non-pathogenic LRRK2 remains largely unknown. LRRK2 expression was examined in murine dorsal root ganglia (DRGs) following sciatic nerve crush (SNC) injury. Regenerative axon growth was assessed using cultured adult DRG neurons after genetic or pharmacological inhibition of LRRK2. Axon regeneration after SNC injury was evaluated in vivo following oral administration of the LRRK2 inhibitors, MLi-2 or PF-06447475. Axonal trafficking experiments and phosphoproteomic analyses were performed to investigate mechanisms underlying axon growth promotion induced by LRRK2 inhibitors. SNC injury reduced LRRK2 expression in DRGs. Genetic and pharmacological inhibition of LRRK2 enhanced regenerative axon growth in culture. Oral administration of MLi-2 or PF-06447475 promoted axon regeneration in vivo after SNC injury. MLi-2 enhanced mitochondrial trafficking, and phosphoproteomic analyses identified cellular processes and kinase-substrate signalling networks associated with a pro-regenerative state triggered by LRRK2 inhibition. These findings identify endogenous, non-pathogenic LRRK2 as a suppressor of axon regeneration. They also support the potential repositioning of small-molecule LRRK2 inhibitors, including clinically advanced compounds and those in preclinical development, as therapeutic strategies to enhance peripheral nerve regeneration.
Ischaemic stroke is characterised by acute cerebrovascular occlusion, blood-brain barrier (BBB) breakdown and a narrow therapeutic window for recovery. Its treatment is a clinical challenge due to the risk of reperfusion injury and the limited efficacy of thrombolytic therapies; therefore, novel therapeutic approaches are needed. Histone deacetylase inhibitors (HDACi) have emerged as neuroprotective agents in stroke models, but their effect on preserving BBB integrity is unexplored. Our aim was to investigate the effects of the HDACi, suberoylanilide hydroxamic acid (SAHA), on BBB changes in a cell culture model of ischaemic stroke. The effects of SAHA were tested on a human BBB co-culture model following a 6-h oxygen-glucose deprivation (OGD) under normoxia and during a 24 h reoxygenation (OGD/R). SAHA treatment ameliorated the OGD/R-induced loss of BBB integrity, as shown by an increase in transendothelial electrical resistance and reduced BBB permeability. The expression of genes involved in cell proliferation decreased, whereas an increase was measured for basement membrane protein, glycocalyx-synthesis enzyme and Wnt signalling-related genes. SAHA treatment elevated the claudin-5 protein expression and a metabolic shift from glycolysis to aerobic respiration was observed. Our results suggest that SAHA could be a potential adjunctive therapeutic drug for the treatment of ischaemia-reperfusion injury via BBB protection. Because SAHA has already been approved for human use as the anticancer drug vorinostat, its repurposing to restore BBB functions and prevent poststroke damages may be greatly facilitated.
Binding kinetics are essentially based on rate constants. Yet, this view has been challenged by the idea that 'binding fluxes' are dynamic and therefore more relevant. Those fluxes refer to the rate at which a target/receptor changes from one state into another through ligand/drug binding or a conformational change. Besides acting as building blocks for many algebraic expressions, they also determine how the concentration of each individual target state evolves over time. Here we show that such fluxes offer additional opportunities for understanding and predicting ligand binding. Simulated binding data are obtained by solving the relevant set of flux-based differential equations for increasingly complex ligand binding models over very small time intervals by Euler's method. As input, they require only ligand concentration(s) and rate constants. Compared to often-complex algebraic expressions, binding fluxes allow more intuitive/inductive insight into different aspects of ligand binding such as the occurrence of transient binding overshoots and the effect of a closing lid over the ligand's binding pocket on ligand dissociation. These examples disclose fundamental principles that govern ligand binding and, above all, they highlight the essential role of rate constants in all the examined binding models. Binding fluxes and rate constants complement each other: They respectively indicate how and why binding processes evolve in a certain fashion. The presented flux-based approaches have the advantage to address pre-equilibrium as well as equilibrium conditions and can be applied to any ligand-binding model.
Aspergillus fumigatus (A. fumigatus) exposure causes of severe allergic asthma, characterized by airway inflammation and epithelial dysfunction. TMBIM6 (Bax inhibitor-1) has been implicated in airway epithelial stress responses and AKT signalling. This study aimed to elucidate the therapeutic potential of the drug called the Bax inhibitor-1 antagonist (BIA) and its structural analogues in a murine model of A. fumigatus-induced allergic asthma. 19 BIA analogues were synthesized and evaluated alongside the original drug BIA in a murine model of A. fumigatus-induced airway inflammation. Inflammatory phenotypes were assessed by analysing bronchoalveolar lavage fluid (BALF), lung histopathology, quantification of T-helper 2 (Th2) and Th17 cytokines. Mechanistic investigations evaluated the AKT/NLRP3 pathway and epithelial-derived cytokines, while TMBIM6-mediated ER Ca2+ flux was monitored using a TMBIM6-GCaMP3 reporter system. BIA and its analogues significantly attenuated inflammatory cell infiltration, goblet cell hyperplasia, airway remodelling and Th2-associated cytokine expression in the lungs of A. fumigatus-challenged mice. BIA and selected analogues also suppressed Th17-associated cytokine expression. Moreover, BIA analogues preferentially reduced epithelial-derived cytokine expression. Mechanistically, BIA and select analogues markedly suppressed AKT phosphorylation and NLRP3 expression in lungs and airway epithelial cells. Pharmacological inhibition and TMBIM6 knockdown supported the involvement of the TMBIM6/AKT/NLRP3 signalling axis, while BIA and select analogues inhibited TMBIM6-mediated ER calcium leakage. BIA and its analogues attenuate A. fumigatus-induced allergic lung inflammation by targeting the TMBIM6/calcium/AKT axis, suppressing NLRP3 signalling and epithelial-derived inflammatory cytokines. These findings highlight this axis as a promising therapeutic target for fungal-associated airway inflammation.
Lobeglitazone is a thiazolidinedione and PPARγ agonist that improves metabolic parameters and hepatic steatosis, but its mechanisms are not fully understood. This study investigated the effects of lobeglitazone on hepatic transcriptomic and metabolic profiles in a rat model of obesity and Type 2 diabetes mellitus. Male Otsuka Long-Evans Tokushima fatty rats were fed a high-fat, high-carbohydrate (HF/HC) diet for 15 weeks and treated with lobeglitazone or vehicle. Metabolic parameters, liver function and histology were assessed. RNA sequencing was conducted to identify changes in hepatic gene expression, and metabolomic profiling was performed on liver and plasma samples. Mechanistic validation was conducted in HepG2 cells using siRNA-mediated PPARγ knockdown. Lobeglitazone treatment improved glucose tolerance and decreased plasma triglyceride and total cholesterol levels. Histological analyses indicated reduced hepatic steatosis, ballooning and lobular inflammation, reflecting protection against hepatic steatosis. RNA sequencing revealed 334 DEGs between the HF/HC-lobeglitazone and HF/HC groups, with pathway enrichment analyses indicating modulation of pathways related to central carbon metabolism. Five pyruvate metabolism-associated genes were down-regulated by lobeglitazone. Quantitative PCR confirmed selected transcriptomic changes, although mitochondrial pyruvate carrier (MPC) 1 and 2 mRNA levels were not significantly altered. In contrast, MPC1 and MPC2 protein levels were markedly reduced. Metabolomics showed increased hepatic and plasma pyruvate, amino acids involved in pyruvate production and hydroxybutyrates, suggesting reduced mitochondrial pyruvate flux. Functional assays demonstrated decreased mitochondrial pyruvate levels following lobeglitazone treatment. PPARγ knockdown abolished lobeglitazone-induced down-regulation of MPC proteins. Lobeglitazone treatment was associated with improved hepatic steatosis and liver-associated metabolic parameters, accompanied by transcriptional and metabolomic changes related to mitochondrial pyruvate metabolism. These findings are correlative and provide new insights into the hepatic actions of lobeglitazone in metabolic disease.
Hyperuricaemia, a severe metabolic disorder linked to gout, is increasingly prevalent worldwide. Radix astragali, as a drug-food homologous material, has significantly expanded the market for novel functional foods. The solid-state fermentation products of R. astragali and Paecilomyces cicadae (RPF) promise to be candidates for lowering uric acid. Here, we have investigated the effects of RPF, using a model of hyperuricaemia in rats. Hyperuricaemia, and damage to liver and kidney, was induced in male Sprague-Dawley rats receiving a high purine diet. Gut microbiota and short-chain fatty acid metabolism were examined by multi-omics analysis of rat faeces. Faecal microbiota transplantation was used to assess the therapeutic potential of gut microbiota and RPF. Effects of Eubacterium siraeum on uric acid and short-chain fatty acid metabolism were examined, in vitro and in hyperuricaemic rats. RPF regulated dysbiosis of gut microbiota and restored the relative abundance of Ruminococcus and Eubacterium, which was associated with normalisation of serum levels of uric acid and short chain fatty acids. In vitro, the E. siraeum DSM15702 strain extensively degraded uric acid. In vivo data from probiotic-treated, hyperuricaemic rats, indicated a reduction of circulating uric acid levels. Our study suggests that the gut microbiota-short chain fatty acid axis may play a crucial role in maintaining intestinal homeostasis and in modulating the excretion of uric acid. E. siraeum may serve as a potential adjunct therapy for management of hyperuricaemia.
Apelin and Elabela are endogenous ligands of the apelin receptor (apelin receptor/APJ), a GPCR involved in cardiovascular regulation and body fluid homeostasis. The human receptor contains a conserved disulfide bridge linking the N-terminal domain to extracellular loop 3 (ECL3) via Cys19 and Cys281, forming a structural constraint analogous to a fourth extracellular loop ('ECL4'). In the chemokine receptor family, this motif plays a critical role in ligand engagement and receptor activation. The functional role of this disulfide bridge was investigated using site-directed mutagenesis (Cys19Ala and Cys281Ala), plasmon waveguide resonance binding assays and BRET-based biosensors to monitor Gαi activation and β-arrestin-2 recruitment. Disruption of the disulfide bridge did not affect receptor surface expression but markedly impaired binding of apelin fragments (pE13F and K17F), leading to reduced Gαi signalling and β-arrestin-2 recruitment. In contrast, binding of the Elabela fragment K22P and the subsequent apelin receptor signalling activation were largely preserved. Antagonist antibodies (JN241 and JN241-Fc) retained activity, whereas the agonist antibody JN241-9-Fc showed strongly reduced efficacy for the mutated receptors. The N-terminal/ECL3 disulfide bridge is a critical structural determinant for apelin binding and apelin receptor activation but is less critical for Elabela signalling, supporting distinct modes of ligand engagement. Antibody-mediated agonism is particularly sensitive to alterations of « ECL4 » without affecting its binding, suggesting that this structural constraint is required for optimal apelin receptor activation. The apelin receptor shares functional similarities with the chemokine receptors with respect to this.
Anthracyclines such as doxorubicin (DOXO) remain a cornerstone of cancer therapy but are associated with a high risk of cardiotoxicity and subsequent heart failure (HF). Impairment of NO/soluble guanylyl cyclase (sGC)/cGMP pathway has been reported in anthracycline-induced cardiomyopathy. This raises the hypothesis that increasing cGMP by sGC stimulation could preserve cardiac function even after HF has developed. This study aimed to evaluate the long-term effects of treatment with sGC stimulator BAY 41-8543 in a model of DOXO-induced HF with nephrotic syndrome in hypertensive rats. Male Ren-2 transgenic rats received five weekly intravenous injections of DOXO (cumulative dose 10 mg·kg-1) to induce cardiomyopathy. After two additional weeks, animals were treated with either BAY 41-8543 (10 mg·kg-1·day-1) or an ACE inhibitor (ACEi; trandolapril, 0.25 mg·kg-1·day-1). Echocardiography, blood and urine collection were performed at baseline (week -1) and 4 weeks after the treatment started to assess cardiac ventricular function, cardiac and renal biomarkers; survival at 20 weeks. Treatment with BAY 41-8543 improved long-term survival, preserved left and right ventricular systolic function and reduced myocardial expression of inflammation-related genes, particularly those linked to type I interferon signalling. ACEi provided stronger benefits in survival and structural remodelling. Kidney damage and function was not improved by any treatment compared to placebo. The sGC stimulator BAY 41-8543 exerted significant cardioprotective effects in DOXO-induced HF. Therefore, sGC stimulators may represent a promising therapeutic option for anthracycline-induced cardiomyopathy, although additional studies are required to fully investigate their therapeutic potential.
Artificial intelligence (AI) is evolving from a predictive tool into a foundational computational infrastructure for mechanism-driven pharmacology, fundamentally reshaping drug discovery. This review examines how this transformation addresses persistent challenges in target validation, including data biases and the need for model interpretability, by integrating network pharmacology with advanced deep learning architectures. Specifically, graph neural networks decipher the complex topology of biological systems and transformer models facilitate the fusion of multimodal data, from genomics to real-world clinical records. Coupled with physics-informed neural networks, this integrated framework operates as a predictive computational microscope. It enables comprehensive in silico simulations that span multiple biological scales, encompassing atomic-level molecular interactions and longitudinal patient trajectories. We demonstrate that this AI-driven paradigm is essential for advancing precision medicine, as it systematically translates vast and heterogeneous datasets into testable mechanistic hypotheses. Consequently, this approach accelerates the development of safer, more effective and patient-specific therapies, by de-risking target validation and elucidating novel therapeutic mechanisms. It directly addresses some of the most pressing inefficiencies in contemporary drug discovery and development, offering a pathway towards more rational and efficient therapeutic innovation.
Obesity is a chronic, relapsing, multisystem disease in which cardiometabolic risk arises from excess adiposity and progressive dysfunction of peripheral organs, ultimately disrupting endocrine and metabolic crosstalk among tissues. Within this network, sulphur-based biology, centred on hydrogen sulphide and related reactive sulphur species, has emerged as a key regulator of metabolic homeostasis, vascular tone, inflammatory response and mitochondrial function. Here, we review the chemical and mechanistic landscape of sulphaceutics (pharmacological sulphur-releasing agents) and sulphanutraceutics (diet-derived organosulphur compounds), focusing on their capacity to reprogramme peripheral dysfunctions in obesity. Evidence from experimental models, also supported by emerging human data, indicates that sulphur-based interventions can enhance skeletal muscle insulin signalling and performance, restore endothelial reactivity and reduce vascular inflammation, thereby modulating adipose expansion and inflammatory tone. These actions reflect the engagement of upstream redox-sensitive regulatory nodes rather than non-specific antioxidant effects, consistent with a system pharmacology mode of action.
TQC3721 is a novel inhaled dual phosphodiesterase (PDE3/4) inhibitor designed to provide bronchodilation and anti-inflammatory effects for chronic obstructive pulmonary disease (COPD). First-in-human randomised, double-blind, placebo-controlled phase I (SAD: 0.2 to 24 mg single dose; MAD: 12 mg once daily (QD) for 7 days in healthy subjects) and phase IIa studies (0.75 to 6 mg once or twice daily for 4 weeks in moderate-to-severe patients with COPD) were conducted. Primary outcomes included safety, pharmacokinetics (PKs) and pharmacodynamics (PDs), change from baseline of forced expiratory volume in the first second [FEV1], and FEV1 at 12 and 24 h post-dose on days 1 and 28. TQC3721 was rapidly absorbed (median Tmax of 0.25 to 0.5 h), mainly by pulmonary absorption rather than gastrointestinal absorption, along with low systemic exposure and lack of significant accumulation. TQC3721 demonstrated favourable safety profiles in healthy subjects and patients with COPD. In patients with COPD, TQC3721 produced rapid and outstanding bronchodilation effect sustained over 12 h post-administration, with FEV1 peaking at approximately 2 h post-dose and returning to baseline levels by 12 h, which supports a twice-daily dosing regimen for the future, and peak FEV₁ improvements ranging from 186 to 272 ml across dose groups after 4 weeks of treatment. Moreover, twice-daily 3 and 6 mg regimens were recommended for further clinical study. Pharmacokinetic features, significant bronchodilation effects and overall favourable safety characteristics support further clinical development of TQC3721 as a potential dual-mechanism therapy for COPD.