Biology subjects

Breuils-Bonnet, S.

Publications and source records attributed to Breuils-Bonnet, S..

9 recordsLinked to original sources

bioRxiv2026

Multi-Omic Profiling Defines the Renal Mechanisms of Cardiovascular-Kidney-Metabolic Syndrome in Pulmonary Arterial Hypertension

Background: Cardiovascular-kidney-metabolic (CKM) syndrome integrates cardiac, renal, and metabolic abnormalities that drive multi-organ injury. In pulmonary arterial hypertension (PAH), CKM manifests as systemic metabolic derangements, right ventricular dysfunction, and renal compromise. Renal dysfunction strongly predicts mortality in PAH, yet current therapies provide little renal benefit. Moreover, the mechanisms driving PAH nephropathy remain poorly understood, limiting our ability to effectively treat PAH-CKM. Methods: Single-nucleus RNA sequencing identified cell-type-specific transcriptional alterations in autopsy-derived kidneys from control (n=5) and PAH (n=4) patients. Mitochondrial, cytoplasmic, and phosphoproteomic analyses profiled proteomic alterations. AlphaFold 3/ChimeraX modeling defined the predicted structural consequences of altered protein phosphorylation. Histological analysis assessed renal fibrosis, glomerular structure, immune cell infiltration, and nephron segment density. Results: 3 of 4 PAH patients exhibited renal impairment, with a cohort mean estimated glomerular filtration rate of 61 plus or minus 36 mL/min/1.73m squared. snRNA-seq identified a distinct cellular architecture in PAH kidneys, marked by an increase in thick ascending limb, proximal tubule, and immune cell nuclei and depletion of collecting duct nuclei. Transcriptional profiling demonstrated proximal tubule and thick ascending limb cells both upregulated fatty acid oxidation, ferroptosis, and cuproptosis pathways. PAH lymphocytes displayed heightened T87 cell receptor signaling, natural killer cell-mediated cytotoxicity, and Th17 differentiation. Histological analyses demonstrated increased perivascular fibrosis, glomerular T-cell infiltration, and a reduction in glomerular basement membrane density in PAH kidneys. Mitochondrial and cytoplasmic proteomics revealed broad metabolic dysfunction characterized by impaired {beta}-oxidation, TCA cycle activity, amino acid metabolism, transsulfuration, and urea cycle pathways. Phosphoproteomics predicted increased GSK3{beta}, STK, and casein kinase activity in PAH kidneys. Finally, using the totality of our data, we nominated multiple druggable targets that could be evaluated to counteract PAH nephropathy. Conclusions: Integrated multi-omic profiling demonstrates PAH nephropathy is defined by glomerular structural remodeling, proximal nephron ferroptotic and cuproptotic signaling, amino acid metabolic dysregulation, and innate and adaptive leukocyte activation. Future studies intervening on these pathways could lead to the development of novel therapeutics to augment renal function in PAH.

molecular biology↗

bioRxiv2026

Pulmonary Arterial Hypertension Induces a Metabolic and Inflammatory Hepatopathy

Right ventricular failure (RVF) is a robust predictor of mortality in pulmonary arterial hypertension (PAH); however, the mechanisms linking RVF to end-organ dysfunction remain unclear. Hepatic impairments portend poor outcomes in PAH, but the cell-specific effects of PAH on the human liver are unknown. Here, we performed single nucleus RNA sequencing on autopsy-derived liver tissue from five PAH patients and four non-PAH controls and compared these findings to non-alcoholic steatohepatitis (NASH) and Fontan-associated liver disease (FALD). PAH hepatocytes were characterized by a pro-proliferative, Warburg-like metabolic phenotype. PAH endothelial cells (ECs) also adopted a Warburg-like profile. Although EC PI3K-Akt activation was present in PAH and FALD ECs, only PAH ECs demonstrated impaired adhesion/barrier signaling. In PAH hepatic stellate cells (HSCs), PI3K-Akt signaling was enriched, while NASH and FALD HSCs co-activated PI3K-Akt and TGF-{beta}. Activated HSC abundances were increased in PAH livers and associated with heightened central vein fibrosis. PAH and NASH macrophages showed elevated complement signaling but reduced JAK-STAT activity. PAH livers exhibited dysregulated vasoactive gene expression, increased interleukin-6 expression in HSCs, and suppressed hepatocyte ketone metabolism. Correlational analysis demonstrated that HSC HIF-1 activation was associated with PAH severity. In total, these findings define the metabolic and inflammatory hepatopathy of PAH.

biochemistry↗

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

17β-Estradiol Promotes Right Ventricle Angiogenesis via Estrogen Receptor α and Apelin Signaling

Right ventricular (RV) failure is the major cause of mortality in pulmonary hypertension (PH). Adaptive angiogenesis and RV endothelial cell (RVEC) function are major modifiers of RV adaptation in PH, but the underlying mechanisms and their regulators remain incompletely understood. RV adaptation in PH is sexually dimorphic, and 17{beta}-estradiol (E2) exerts protective effects on RV cardiomyocytes. Whether E2 modifies angiogenesis and RVEC function in RV failure remains unknown. We hypothesized that E2 and estrogen receptor (ER) promote RV angiogenesis and RVEC homeostasis in PH and aimed to identify underlying mechanisms. We assessed E2s angiogenic effects using cultured human cardiac microvascular endothelial cells (hCMVECs), RVECs from PH patients with RV failure, and RVECs from sugen/hypoxia (SuHx) and monocrotaline (MCT) rat models. In vivo, we evaluated RV capillary density in PH rats treated with E2 or ER-selective agonist. Apelin signaling was evaluated via apelin receptor blockade. E2 enhanced angiogenesis in male hCMVECs and RV capillary density in female SuHx-PH rats. E2 reversed angiogenic alterations in RVECs from SuHx-PH rats via apelin receptor signaling. In RVECs from PH patients with RV failure, E2 stimulated vascular network formation. In rat and human PH-RVECs, ER was necessary and sufficient to mediate E2-induced angiogenesis. Activation of ER with ER-specific agonist restored RV capillary density in vivo. ER-mediated angiogenesis required apelin signaling. These data indicate that E2 promotes RV angiogenesis via ER and apelin signaling and identify a novel ER-apelin axis in RVECs as a potential therapeutic target to restore RV vascular integrity in PH.

cell biology↗

bioRxiv2025

Impaired Lung BCAA Metabolism Promotes Ferroptosis and Resultant Pulmonary Arterial Hypertension-Associated Hepatopathy

BackgroundDysregulated branched chain amino acid (BCAA) homeostasis occurs in pulmonary arterial hypertension (PAH) as BCAA metabolites accumulate and cause metabolic alterations in pulmonary artery smooth muscle cells (PASMC). In other cells, altered BCAA metabolism promotes ferroptosis, a PAH-inducing metabolic pathway. However, the interplay between BCAAs, lung ferroptosis, and PAH is unexplored, as is the impact of PAH severity on liver molecular regulation, a key unknown as recent clinical data highlight the importance of the lung-right heart-liver axis in PAH outcomes. MethodsHuman metabolomic and transcriptomic studies examined BCAA metabolism and ferroptosis pathways. The relationship between BCAAs and ferroptotic-phenotypes in PASMCs was evaluated. Multi-omics and physiological analyses evaluated how modulation of BCAA catabolism impacted preclinical PAH multi-organ physiology. Confocal microscopy and proteomic analyses assessed hepatic alterations in human PAH. ResultsMetabolomic analyses identified alterations in BCAA metabolites across multiple physiological gradients in patients with pulmonary vascular disease. RNA sequencing demonstrated deficits in the BCAA catabolic and ferroptosis pathways in PAH lungs and smooth muscle cells. In vitro, excess BCAAs induced mitochondrial fragmentation, reactive oxygen species generation, and lipid peroxidation in PASMC. Moreover, BCAAs promoted PASMC death, which ferrostatin-1, a ferroptosis antagonist, rescued. BT2, a small-molecule inducer of BCAA catabolism, reduced PAH severity, improved RV function, and enhanced maximal exercise capacity in monocrotaline rats. BT2 blunted pro-ferroptotic changes in lung metabolites and proteins, and combatted peri-vascular complement deposition. In the liver, BT2 blocked mechanical shear stress phenotypes including hepatocyte nuclear expansion and restructured mitochondrial protein regulation and the metabolomic signature. Additionally, a low BCAA diet modestly combatted preclinical PAH severity. Finally, human PAH livers exhibited increased hepatocyte nuclear size and derangements in liver metabolic regulation. ConclusionsImpaired BCAA metabolism promotes PAH via ferroptosis. PAH severity is associated with hepatic pathological shear stress phenotypes and metabolic alterations, which are combatted by a BCAA-targeted therapy. Graphical Abstract/Summary Figure O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/672819v1_ufig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@1649980org.highwire.dtl.DTLVardef@199c40aorg.highwire.dtl.DTLVardef@1586fdorg.highwire.dtl.DTLVardef@15166c1_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

A critical contribution of cardiac myofibroblasts in right ventricular failure and the role of UCP2 SNPs in the predisposition to RV decompensation in pulmonary arterial hypertension

The mechanism of transition from compensated (cRV) to decompensated right ventricle (dRV) in pulmonary arterial hypertension (PAH) is unknown. We explored the role of RV cardiac myofibroblasts (cMFB) on this transition utilizing a rat model and 3 cohorts of 81 patients which included clinical data, RV tissues and blood. We hypothesized that the loss of UCP2, critical for mitochondrial calcium (mCa++) regulation and cardiac fibroblasts (cFB) differentiation, is associated with dRV in rats and humans; and that a loss-of-function UCP2 SNP (rs659366) may predict dRV in human PAH. We separated rat cRV from dRV based on catheterization and echocardiographic criteria and found a significant increase in cMFB in dRV. In isolated hearts, RV contractility was lower in dRV but not in isolated cardiomyocyte (CM), pointing to a non-CM cause. Mitochondrial respiration was lower in dRV cMFB than in control and cRV cFB. mCa++ was progressively decreased from normal to cRV to dRV c(M)FB, and the same was true for c(M)FB (but not CM) UCP2 levels. Human PAH, but not secondary pulmonary hypertension, dRVs had more cMFB and less UCP2 than control and cRVs. Decreased UCP2 (protein and mRNA) levels and the presence of heterozygous/homozygous UCP2 SNP were associated with worse RV performance (TAPSE, cardiac index), even among patients with similar mean pulmonary arterial pressure. Our data point to a change of cell identity (cFB to cMFB) in the RV as a driver of RV decompensation. UCP2 SNPs are promising biomarkers for early cRV transition to dRV in PAH.

molecular biology↗

bioRxiv2024

Pharmacological Inhibition of Epac1 Protects against Pulmonary Fibrosis by Blocking FoxO3a Neddylation

BackgroundIdiopathic Pulmonary fibrosis (IPF) is characterized by progressive scarring and fibrosis within the lungs. There is currently no cure for IPF; therefore, there is an urgent need to identify novel therapeutic targets that can prevent the progression of IPF. Compelling evidence indicates that the second messenger, cyclic adenosine monophosphate (cAMP), inhibits lung fibroblast proliferation and differentiation through the classical PKA pathway. However, the contribution of the exchange protein directly activated by cAMP 1 (Epac1) to IPF pathophysiological processes is yet to be investigated. ObjectiveTo determine the role of the cAMP-binding protein Epac1 in the progression of IPF. MethodsWe used lung samples from IPF patients or healthy controls, mouse lung samples, or lung fibroblast isolated from a preclinical mouse model of PF induced by bleomycin intratracheal injection. The effect of bleomycin (BLM) treatment was determined in Epac1 knock-out mice or wild-type littermates. Epac1 expression was modulated in vitro by using lentiviral vectors or adenoviruses. The therapeutic potential of the Epac1-selective pharmacological inhibitor, AM-001, was tested in vivo and in vitro, using a bleomycin mouse model of PF and an ex vivo precision-cut lung slices (PCLs) model of human lung fibrosis. ResultsEpac1 expression was increased in the lung tissue of IPF patients, in IPF-diseased fibroblasts and in BLM-challenged mice. Furthermore, Epac1 genetic or pharmacological inhibition with AM-001 decreased normal and IPF fibroblast proliferation and the expression of profibrotic markers, SMA, TGF-{beta}/SMAD2/3, and interleukin-6 (IL-6)/STAT3 signaling pathways. Consistently, blocking Epac1 protected against BLM-induced lung injury and fibrosis, suggesting a therapeutic effect of Epac1 inhibition on PF pathogenesis and progression. Global gene expression profiling revealed a decrease in the key components of the profibrotic gene signature and neddylation pathway in Epac1-deficient lung fibroblasts and IPF human-derived PLCs. Mechanistically, the protective effect of Epac1 inhibition against PF development involves the inhibition of FoxO3a neddylation and its subsequent degradation by NEDD8, and in part, by limiting the proliferative capacity of lung-infiltrating monocytes. ConclusionsWe demonstrated that Epac1 is an important regulator of the pathological state of fibroblasts in PF and that small molecules targeting Epac1 can serve as novel therapeutic drugs against PF.

physiology↗

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

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↗