Biology subjects

Woulfe, K. C.

Publications and source records attributed to Woulfe, K. C..

5 recordsLinked to original sources

bioRxiv2026

Cardiomyocyte NLRP3 signaling in right heart failure is sexually dimorphic via estrogen receptor α

RationaleRV adaptation in pulmonary hypertension is sexually dimorphic and more preserved in women. NLRP3 inflammasome activation contributes to RV failure (RVF) development. However, regulators and downstream effects of NLRP3 activation in the RV remain unknown. ObjectivesWe investigated whether NLRP3 inflammasome activation in RVF is sexually dimorphic, whether NLRP3 is active in RV cardiomyocytes (RVCMs) and causes RVCM contractile dysfunction, and whether 17{beta}-estradiol (E2) and its receptor ER attenuate this process. MethodsWe studied RV tissues from PAH patients with RVF, RV tissues and RVCMs isolated from wild-type and ER loss-of-function mutant rats with RVF, isolated perfused rat hearts, and human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. NLRP3 activation was assessed via RNA-sequencing, proteomics, immunostaining, and downstream target quantification. RV contractility was assessed via pressure-volume loops, perfused heart studies, and contractility and calcium assessments in isolated RVCMs. Measurements and Main ResultsNLRP3 was upregulated in RVCMs during RVF and resulted in altered RVCM calcium handling and RVCM contractile dysfunction. In human RVs, hiPSC-cardiomyocytes and rat RVs, NLRP3 activation and NLRP3-induced RVCM contractile dysfunction were sexually dimorphic and male-biased. Ovariectomy and loss of ER in females eliminated this sex bias. E2, via ER, prevented RVCM NLRP3 activation and NLRP3-induced RVCM contractile dysfunction in males and ovariectomized females during both acute and chronic RV pressure overload. ER directly interacted with NLRP3. ConclusionsNLRP3-driven RVCM contractile dysfunction is male-biased. E2 inhibits NLRP3 through ER to preserve RVCM contractility. Targeting E2-ER-NLRP3 signaling may offer novel therapeutic strategies for RVF in low estrogen states. ImpactThis is the first study to define a novel estradiol-estrogen receptor -NLRP3 axis that modulates RV cardiomyocyte function and RV adaptation in pulmonary hypertension. We demonstrate for the first time that NLRP3 activation is therapeutically targetable in low estrogen states via NLRP3 inhibitors or 17{beta}-estradiol. These findings have direct implications for therapeutic strategies aimed at preserving or restoring RV contractile function in pulmonary hypertension, a current area of unmet clinical need.

molecular biology↗

bioRxiv2026

Multi-omics Insight into Cardiac Myofibril Remodeling in Post-Prandial Burmese Pythons

Burmese pythons exhibit rapid cardiac remodeling in response to a dramatic increase in metabolic rate during digestion. Here, we performed single-myofibril mechanics measurements and myosin heavy chain metabolic assays to evaluate the impact of feeding on the cardiomyocyte sarcomere - the fundamental molecular unit of muscle contraction - using two experimental paradigms: normal feeding (one meal per month) and frequent feeding (eight meals per month). Myofibril tension and rate of relaxation increased during digestion in both paradigms, while frequent feeding was further associated with slower myofibril activation kinetics and faster myosin heavy chain ATP turnover. To identify molecular changes at the sarcomere and gain potential mechanistic insight, we performed multi-omics analyses. RNA sequencing identified increased expression of some sarcomere genes during digestion; however, proteomics analysis suggested a delay in sarcomere protein synthesis at the peak of remodeling, as expression of many sarcomere proteins decreased. Analysis of post-translational modifications (ubiquitinomics, phospho-proteomics, acetylomics) identified hundreds of significantly regulated sites on sarcomere proteins during digestion, including many on the tension-regulating titin and myosin heavy chain proteins. Our results detail the molecular underpinnings of cardiac remodeling in digesting Burmese pythons and suggest that natures solution for rapidly increasing cardiac contractility is a post-translational sarcomere tuning program.

molecular biology↗

bioRxiv2025

Low Dose GLP-1 Therapy Attenuates Pathological Cardiac and Hepatic Remodelling in HFpEF Independent of Weight Loss

BACKGROUND AND AIMSHeart failure with preserved ejection fraction (HFpEF) remains a therapeutic challenge. GLP-1 receptor agonists (GLP-1RAs) show clinical promise, and the prevailing hypothesis is that their benefits are primarily driven by weight loss and the downstream benefits of improved functional status. We investigated the weight loss-independent effects of low-dose GLP-1RA therapy in a clinically relevant rodent model of severe cardiometabolic HFpEF. METHODSTen-week-old male ZSF1 obese rats with spontaneous HFpEF were treated with low-dose semaglutide (30 nmol/kg twice weekly, n=6) or vehicle for 16 weeks. Comprehensive assessments included body weight, 2-D echocardiography, invasive hemodynamics, exercise capacity as well as cardiac and hepatic fibrosis and lipid deposition. The study utilized advanced multi-omics approaches, including single-cell RNA sequencing of the heart and liver, as well as cardiac, hepatic and plasma proteomics, to explore underlying mechanisms. RESULTSIn ZSF1 obese rats, low-dose semaglutide in the absence of weight loss, significantly improved cardiac function, exercise tolerance, and attenuated fibrosis in the heart and liver. Interestingly, semaglutide therapy reduced cardiac and hepatic lipid content as well as lipid droplets in cardiac myocytes and hepatocytes. Mechanistically, multi-omics analyses of cardiac and hepatic tissues revealed that semaglutide exerted these benefits by improving cardiac metabolism, interfering with pro-fibrotic and pro-hypertrophic signals, and by reducing systemic inflammation. CONCLUSIONSLow-dose semaglutide provides significant cardioprotective, hepatoprotective, and metabolic benefits in HFpEF independent of weight loss. Our findings support the investigation of lower GLP-1RA dosing in HFpEF and other cardiovascular conditions, including in non-obese patients, to expand the clinical utility of these potent drugs. Translational PerspectiveWe demonstrate that low-dose semaglutide attenuates HFpEF-mediated pathological cardiac and hepatic remodelling in HFpEF independently of the weight loss effects of GLP-1 receptor activation. Primary mechanisms are attenuated cardiac and hepatic fibrosis and reverse lipid transport. These findings provide a mechanistic basis for the direct cardiovascular actions of GLP-1RAs, revealing their potential to modulate key disease drivers like fibrosis and lipotoxicity. These data support the use of lower, better-tolerated doses of GLP-1RAs to treat HFpEF, potentially benefiting a wider range of patients, including those who are not obese or who suffer from side effects with current GLP-1 regimens.

pharmacology and toxicology↗

bioRxiv2020

Maturation of human induced pluripotent stem cell-derived cardiomyocytes for modeling hypertrophic cardiomyopathy

RationaleHuman induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are a powerful platform for biomedical research. However, they are immature, which is a barrier to modeling adult-onset cardiovascular disease. ObjectiveWe sought to develop a simple method which could drive cultured hiPSC-CMs towards maturity across a number of phenotypes. Methods and resultsCells were cultured in fatty acid-based media and plated on micropatterned surfaces to promote alignment and elongation. These cells display many characteristics of adult human cardiomyocytes, including elongated cell morphology, enhanced maturity of sarcomeric structures, metabolic behavior, and increased myofibril contractile force. Most notably, hiPSC-CMs cultured under optimal maturity-inducing conditions recapitulate the pathological hypertrophy caused by either a pro-hypertrophic agent or genetic mutations. ConclusionsThe more mature hiPSC-CMs produced by the methods described here will serve as a useful in vitro platform for characterizing cardiovascular disease.

cell biology↗

bioRxiv2019

Novel model of distal myopathy caused by the myosin rod mutation R1500P disrupts acto-myosin binding

IntroductionMore than 400 mutations in {beta}-myosin, a slow myosin motor, can cause both cardiac and skeletal myopathy in humans. A small subset of these mutations, mostly located in the myosin rod, leads to a progressive skeletal muscle disease known as Laing distal myopathy (MPD1). While this disease has previously been studied using a variety of systems, it has never been studied in the mammalian muscle environment. Here, we describe a mouse model for the MPD1-causing mutation R1500P to elucidate disease pathogenesis and to act as a future platform for testing therapeutic interventions.\n\nMethodsBecause mice have very few slow skeletal muscles compared to humans, we generated mice expressing the {beta}-myosin R1500P mutation or WT {beta}-myosin in fast skeletal muscle fibers and determined the structural and functional consequences of the R1500P mutation.\n\nResultsThe mutant R1500P myosin affects both muscle histological structure and function and the mice exhibit a number of the histological hallmarks that are often identified in patients with MPD1. Furthermore, R1500P mice show decreased muscle strength and endurance, as well as ultrastructural abnormalities in the SR & t-tubules. Somewhat surprisingly because of its location in the rod, the R1500P mutation weakens acto-myosin binding by affecting cross-bridge detachment rate.\n\nConclusionsWhile each group of MPD1-causing mutations most likely operates through distinct mechanisms, our model provides new insight into how a mutation in the rod domain impacts muscle structure and function and leads to disease.

molecular biology↗