Biology subjects

Boucherat, O.

Publications and source records attributed to Boucherat, O..

6 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

Exploring the Role of Hypusine Signaling in Vascular Smooth Muscle Cells for Mitigating Restenosis in Coronary Artery Disease.

BackgroundPost-surgical restenosis in patients with coronary artery disease (CAD) is a pathological vascular remodeling process characterized by neointimal hyperplasia, mainly driven by vascular smooth muscle cells (VSMCs) phenotypic switching toward synthetic and proliferative state. This study identifies novel signaling pathway promoting pro-proliferative phenotype of VSMC and contributing to the neointimal hyperplasia development. MethodsThe expression of hypusine signaling components was evaluated in human primary culture of coronary artery smooth muscle cells (CoASMCs) isolated from controls and patients with CAD, using comparative proteomic analysis and western blotting, as well as in three preclinical animal models of restenosis; rat carotid injury, mice carotid ligation and canine coronary artery bypass graft. CAD-CoASMCs proliferation was assessed by western blot and immunofluorescence with pharmacological (GC7) and molecular (shRNA) inhibitors of deoxyhypusine synthase (DHPS). The contribution of hypusine signaling to neointimal hyperplasia was investigated using both pharmacological and smooth muscle cell-specific knockout mice approaches. Additionally, human saphenous vein and human coronary artery tissue cultures were employed to explore the translational potential of targeting hypusine signaling to prevent neointimal hyperplasia. ResultsAll components of the hypusine pathway (eukaryote translational initiation factor 5A (eIF5A), deoxyhypusine hydroxylase (DOHH) and DHPS) were significantly overexpressed in CAD-CoASMCs and in preclinical animal models of restenosis. Pharmacological and molecular inhibition of DHPS reduced eIF5A hypusination, VSMC proliferation and expression of extracellular matrix proteins. Proteomic and KEGG analyses demonstrated disruption of cell cycle and DNA replication pathways, including a downregulation of threonine tyrosine kinase (TTK). Our findings suggest that TTK acts as a downstream effector of hypusine signaling, partly mediating to the proliferative effects observed in CAD-CoASMCs. In vivo, pharmacological and genetic inhibition of DHPS significantly reduced neointimal hyperplasia without adverse effects. Finally, ex vivo human tissue culture confirmed that GC7 mitigates growth factor-induced vascular remodeling. ConclusionsHypusine signaling is a critical regulator of VSMC proliferation for neointimal hyperplasia. Inhibiting DHPS reduces vascular remodeling, making it a promising target for preventing restenosis after coronary interventions. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIHypusine signaling is markedly upregulated in coronary artery smooth muscle cells (CoASMCs) from patients with coronary artery disease (CAD) and in multiple preclinical models of restenosis. C_LIO_LIProteomic profiling identifies DHPS, the rate-limiting enzyme for eIF5A hypusination, as a key driver of vascular smooth muscle cell (VSMC) pro-proliferative phenotype and extracellular matrix production. C_LIO_LIPharmacological (GC7) and genetic inhibition of DHPS effectively suppress eIF5A hypusination, attenuate the synthetic and proliferative CAD-CoASMCs phenotype, and significantly reduce neointimal hyperplasia in rodent models of vascular injury. C_LIO_LIEx vivo human tissue demonstrates that DHPS inhibition prevents neointimal hyperplasia, providing strong translational evidence. C_LI What Are the Clinical Implications?O_LIThese findings establish hypusine signaling as a previously unrecognized regulator of pathological VSMC activation in CAD and restenosis. C_LIO_LIDHPS inhibition emerges as a promising therapeutic strategy to prevent neointimal hyperplasia following coronary interventions such as angioplasty, stenting, or bypass grafting. C_LIO_LICollectively, our data support the clinical development of selective DHPS inhibitors as a novel class of therapeutics to improve long-term outcomes after coronary revascularization and potentially other occlusive vascular diseases. C_LI

pathology↗

bioRxiv2025

Levosimendan Ameliorates Adverse Pulmonary Vascular Remodeling in Group-2 Pulmonary Hypertension.

AimsPulmonary hypertension (PH) due to left heart disease (Group-2PH) is the most common form of PH and comprises two distinct subtypes: isolated post-capillary-PH (IpcPH) and combined post-and pre-capillary-PH (CpcPH). Despite its high prevalence and poor prognosis, no targeted therapies are currently approved, largely due to the absence of reliable preclinical models that recapitulate these human hemodynamic phenotypes. Levosimendan, a calcium sensitizer with inotropic and vasodilatory properties, has shown promise in early clinical trials for Group-2PH, but its mechanisms of action remain unclear. This study aimed to develop and validate experimental models of IpcPH and CpcPH and to assess the therapeutic effects of levosimendan on pulmonary vascular remodeling, inflammation, and cardiac function to support ongoing clinical translation. Methods and ResultsIn a multicentre preclinical study, we established two rodent models that faithfully replicate the human IpcPH and CpcPH hemodynamic profiles. CpcPH animals exhibited severe pulmonary vascular remodeling, inflammatory cell infiltration, and a distinct pro-proliferative transcriptomic signature, whereas IpcPH animals showed minimal pulmonary vascular involvement. Levosimendan (3 mg/kg/day, 3 weeks) improved biventricular function and pulmonary hemodynamics in both models. In CpcPH, levosimendan additionally reduced pulmonary vascular remodeling, attenuated inflammation, and partially reversed disease-associated transcriptomic reprogramming. Transcription factor enrichment analysis identified NF-{kappa}B as a key upstream regulator inhibited by treatment. In a translational extension, nine circulating inflammation-related-proteins differentiated CpcPH from IpcPH patients; among them, TNF, IL-12B, 4E-BP1, NT-3, NGF, FGF21, and FGF23 predicted poor survival. IL-18 and 4E-BP1 were elevated in CpcPH lungs and decreased following levosimendan treatment. ConclusionsInflammation is a major contributor to adverse pulmonary vascular remodeling in CpcPH. Levosimendan improves cardiac performance and mitigates pulmonary vascular inflammation and remodeling, supporting its potential as a dual-action therapeutic agent in Group-2PH. These findings validate novel preclinical models and provide mechanistic evidence reinforcing ongoing clinical evaluation of levosimendan in this condition. Translational perspectiveGroup-2 PH lacks targeted therapies, partly due to the absence of validated preclinical models. We validated models recapitulating human IpcPH and CpcPH and identified inflammation as a key driver of pulmonary vascular remodeling in CpcPH. Levosimendan improved biventricular function and reduced vascular remodeling and inflammation through NF-{kappa}B inhibition. Circulating IL-18 and 4E-BP1 reflected disease severity and treatment response. These findings establish robust translational models, reveal inflammatory mechanisms underlying CpcPH, and provide mechanistic evidence supporting ongoing clinical trials of levosimendan as a dual-action therapeutic strategy in Group-2 PH.

molecular biology↗

bioRxiv2024

Exploring Integrin α5β1 as a Potential Therapeutic Target for Pulmonary Arterial Hypertension: Insights from Comprehensive Multicenter Preclinical Studies

Pulmonary arterial hypertension (PAH) is characterized by obliterative vascular remodeling of the small pulmonary arteries (PA) and progressive increase in pulmonary vascular resistance (PVR) leading to right ventricular (RV) failure. Although several drugs are approved for the treatment of PAH, mortality remains high. Accumulating evidence supports a pathological function of integrins in vessel remodeling, which are gaining renewed interest as drug targets. However, their role in PAH remains largely unexplored. We found that the arginine-glycine-aspartate (RGD)-binding integrin 5{beta}1 is upregulated in PA endothelial cells (PAEC) and PA smooth muscle cells (PASMC) from PAH patients and remodeled PAs from animal models. Blockade of the integrin 5{beta}1 or depletion of the 5 subunit resulted in mitotic defects and inhibition of the pro-proliferative and apoptosis-resistant phenotype of PAH cells. Using a novel small molecule integrin inhibitor and neutralizing antibodies, we demonstrated that 5{beta}1 integrin blockade attenuates pulmonary vascular remodeling and improves hemodynamics and RV function in multiple preclinical models. Our results provide converging evidence to consider 5{beta}1 integrin inhibition as a promising therapy for pulmonary hypertension. One sentence summaryThe 5{beta}1 integrin plays a crucial role in pulmonary vascular remodeling.

pathology↗

bioRxiv2024

Endothelial fatty acid-binding proteins contribute to the pathogenesis of pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by obliterative vascular remodeling and persistent increase of vascular resistance, leading to right heart failure and premature death. Understanding the cellular and molecular mechanisms will help develop novel therapeutic approaches for PAH patients. Single-cell RNA sequencing (scRNAseq) analysis found that both FABP4 and FABP5 were highly induced in endothelial cells (ECs) of Egln1Tie2Cre (CKO) mice, which was also observed in pulmonary arterial ECs (PAECs) from idiopathic PAH (IPAH) patients, and in whole lungs of pulmonary hypertension (PH) rats. Plasma levels of FABP4/5 were upregulated in IPAH patients and directly correlated with severity of hemodynamics and biochemical parameters using plasma proteome analysis. Genetic deletion of both Fabp4 and 5 in CKO mice (Egln1Tie2Cre/Fabp4-5-/-, TKO) caused a reduction of right ventricular systolic pressure (RVSP) and RV hypertrophy, attenuated pulmonary vascular remodeling and prevented the right heart failure assessed by echocardiography, hemodynamic and histological analysis. Employing bulk RNA-seq and scRNA-seq, and spatial transcriptomic analysis, we showed that Fabp4/5 deletion also inhibited EC glycolysis and distal arterial programming, reduced ROS and HIF-2 expression in PH lungs. Thus, PH causes aberrant expression of FABP4/5 in pulmonary ECs which leads to enhanced ECs glycolysis and distal arterial programming, contributing to the accumulation of arterial ECs and vascular remodeling and exacerbating the disease.

molecular biology↗

bioRxiv2024

ATP Citrate Lyase Drives Vascular Remodeling Diseases Development Through Metabolic-Epigenetic Reprograming.

Our study explores the previously uncharted role of ATP-citrate lyase (ACLY) in vascular remodeling within the pulmonary and coronary arteries, providing novel insights into the pathogenesis of pulmonary hypertension and coronary artery diseases. ACLY, involved in de novo lipid synthesis and histone acetylation, has emerged as a key regulator in sustaining vascular smooth muscle cell (VSMC) proliferation and survival. Utilizing human coronary and pulmonary artery tissues, our findings reveal an upregulation of ACLY expression during vascular remodeling processes. Inhibition of ACLY, achieved through pharmacological and molecular interventions in humans primary cultured VSMCs, leads to decreased proliferation, migration, and resistance to apoptosis. Mechanistically, these effects are associated with diminished glycolysis, lipid synthesis, GCN5-dependent histone acetylation, and FOXM1 activation. In vivo experiments, combining pharmacological and VSMC-specific ACLY knockout mice, ACLY inhibition demonstrates its efficacy in mitigating coronary artery remodeling and reducing pulmonary hypertension. Notably, initiating ACLY inhibition post-disease onset reverses pathological conditions, positioning ACLY as a promising therapeutic target. Human ex vivo tissue culture further supports our findings, showing reduced vascular remodeling in cultured human coronary artery rings and a reversal of pulmonary artery remodeling in precision-cut lung slices upon ACLY inhibition. This study introduces a groundbreaking concept, linking disparate abnormalities in vascular diseases to a common pathogenetic denominator, ACLY. The identified "multiple hit" therapeutic approach presents potential targets for addressing complex vascular diseases, offering avenues for future clinical interventions. ONE SENTENCE SUMMARYOur study delineates the pivotal role of ATP-citrate lyase in orchestrating vascular remodeling, establishing it as a compelling translational target for therapeutic interventions in pulmonary hypertension and coronary artery disease.

physiology↗