Biology subjects

Petrache, I.

Publications and source records attributed to Petrache, I..

3 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↗

bioRxiv2025

Sexually dimorphic role of estrogen receptor α in preserving right ventricular endothelial integrity

Right ventricular (RV) function and adaptation to afterload increase determine survival in pulmonary hypertension (PH). RV adaptation in PH is sexually dimorphic and more preserved in females, mediated by protective estrogen receptor (ER) signaling in cardiomyocytes. However, the effects of ER on RV endothelial cells (RVECs), a critical mediator of RV homeostasis and adaptation, are unknown. We hypothesized that ER exerts sexually dimorphic pro-angiogenic effects on RVECs in vitro and promotes RV vascularization in vivo. Compared to cells isolated from wild-type animals, RVECs from male and female rats with an ER loss-of-function mutation (ERMut) showed reduced ability to form pseudo-vascular networks and migrate. RVECs from female ERMut rats demonstrated increased apoptosis. In a PH model induced by monocrotaline (MCT), female ERMut rats exhibited increased RV hypertrophy and reduced RV capillary density before (10 days) and at the time of established PH (28 days). Capillary rarefaction was associated with increased RVEC apoptosis, and, as identified by single-nucleus RNA-sequencing, by a net loss of the endocardial RVEC sub-population. Differentially expressed gene analysis and pathway analysis identified that capillary and endocardial RVECs from female MCT-PH ERMut rats demonstrated decreased expression of migration pathways and increased expression of apoptosis pathways. These findings reveal a sex-specific endothelial-intrinsic role of ER that is essential for angiogenesis in the RV under both homeostatic and pathological conditions. This effect appears to stem from the enhanced survival and migration capacity of capillary and endocardial RVEC. Collectively, our results identify ER as a potential target for developing sex-specific RV-directed therapies in PH. Translational perspectiveEffects of ER on vascular function in RV failure induced by PH are poorly understood. We unveiled a novel sexually dimorphic role of ER in regulating RV vascularization and RVEC function. Single nucleus RNA-Sequencing in female wild-type and ER loss-of-function rats with PH identified 5 unique RVEC sub-populations under transcriptional control of ER. Our findings provide insights into previously undescribed pro-angiogenic, pro-migratory and anti-apoptotic roles of ER in female RVs and RVECs. Promoting RVEC migration or inhibiting RVEC apoptosis to enhance RV angiogenesis may be viable pathways to maintain RV function in PH patients of either sex. These findings offer novel opportunities and potential therapeutic avenues for preventing or treating RV failure.

cell biology↗

bioRxiv2019

Cigarette Smoke Exposure Impairs β-Cell Function Through Activation of Oxidative Stress and Ceramide Accumulation

ObjectivesEpidemiological studies indicate that first- and second-hand cigarette smoke (CS) exposure are important risk factors for the development of type 2 diabetes (T2D). Additionally, elevated diabetes risk has been reported to occur within a short period of time after smoking cessation, and health risks associated with smoking are increased when combined with obesity. At present, the mechanisms underlying these associations remain incompletely understood. The objective of this study was to test the impact of CS exposure on pancreatic {beta}-cell function using rodent and in vitro models.\n\nMethodsBeginning at 8 weeks of age, C57BL/6J mice were concurrently fed high fat-diet (HFD) and exposed to CS for 11 weeks, followed by an additional 11 weeks of smoking cessation with continued HFD exposure. Glucose tolerance testing was performed during CS exposure and during the cessation period. Cultured {beta}-cells (INS-1) and primary islets were exposed ex vivo to CS extract (CSE), and {beta}-cell function and viability were tested. Since CS increases ceramide in lungs cells and these bioactive sphingolipids have been implicated in pancreatic {beta}-cell dysfunction in diabetes, islet and {beta}-cell sphingolipid levels were measured in islets from CS-exposed mice and in CSE-treated islets and INS-1 cells using liquid chromatography-tandem mass spectrometry.\n\nResultsCompared to HFD-fed ambient air-exposed mice, HFD-fed and CS- exposed mice had reduced weight gain and better glucose tolerance during the active smoking period. Following smoking cessation, CS-mice exhibited rapid weight gain and a significantly greater increase in glucose intolerance compared to non-smoking control mice. CS-exposed mice had higher serum proinsulin/insulin ratios, indicative of {beta}-cell dysfunction, significantly lower {beta}-cell mass (p=0.02), and reduced {beta}-cell proliferation (p=0.006), and increased islet ceramide accumulation. Ex vivo exposure of isolated islets to CSE was sufficient to increase islet ceramide accumulation, reduce insulin gene expression and glucose-stimulated insulin secretion, and increase {beta}-cell oxidative and ER stress. Treatment with the antioxidant N-acetylcysteine, markedly attenuated the effects of CSE on ceramide levels, restored {beta}-cell function and survival, and increased cyclin D2 expression, while also reducing activation of {beta}-cell ER and oxidative stress.\n\nConclusionsOur results indicate that CS exposure inhibits insulin production, processing, and secretion and reduced {beta}-cell viability and proliferation. These effects were linked to increased {beta}-cell oxidative and ER stress and ceramide accumulation. Mice fed HFD continued to experience detrimental effects of CS exposure even during smoking cessation. Elucidation of mechanisms by which CS exposure impairs {beta}-cell function in synergy with obesity will help design therapeutic and preventive interventions for both active and former smokers.

molecular biology↗