Biology subjects

Renault, M.-A.

Publications and source records attributed to Renault, M.-A..

7 recordsLinked to original sources

bioRxiv2026

Desert hedgehog enhances endothelial resilience and prevents atherosclerosis by mitigating PAI-1 signaling

BACKGROUNDAtherosclerotic cardiovascular disease remains the leading cause of death worldwide. Most current pharmacotherapies target conventional risk factors that promote atherosclerosis (e.g., hyperlipidemia) rather than intrinsic resilience factors that protect against atherosclerosis in the face of risk factors. Here, we investigated the role of desert hedgehog (DHH), a canonical ligand of the hedgehog signaling pathway, as a novel resilience factor that restrains endothelial mesenchymal transition (EndoMT) and protects against atherosclerosis. METHODSSingle-cell RNA sequencing (scRNA-seq) was performed on atheroprone and atheroprotective regions of the ApoE knockout mouse aorta to identify mechanoresponsive genes associated with atherosclerosis. Endothelial cell-specific Dhh knockout mice were subjected to partial carotid ligation and hypercholesterolemic conditions to investigate the role of endothelial Dhh in atherosclerosis progression. scRNA-seq, bulk RNA sequencing, endothelial lineage tracing, immunoprecipitation-coupled mass spectrometry, and surface plasmon resonance were used to in-vestigate the role and mechanism of DHH in EndoMT. Pharmacological interventions and recombinant DHH administration were performed in vivo to evaluate therapeutic potential of DHH targeting. DHH expression was also examined in human atherosclerotic arteries and serum samples from patients with coronary artery disease. RESULTSDHH protein expression was enriched in arterial endothelium from mice, porcine, and humans. However, DHH expression was significantly reduced in atherosclerotic arteries and serum from patients with coronary artery disease. scRNA-seq of atheroprone and atheroresistant region of mouse aorta identified Dhh as a novel mechanoresponsive gene enriched in aortic regions exposed to unidirectional laminar flow. Endothelial cell-specific Dhh knockout (DhhecKO) mice exhibited increased atherosclerotic lesion area, large necrotic cores, and reduced collagen content following partial carotid ligation. Similarly, under hypercholesterolemic conditions, both male and female DhhecKO mice showed aggravated atherosclerosis progression. scRNA-seq of DhhecKO mouse aortas revealed an increased proportion of endothelial cells undergoing mesenchymal transition, indicating enhanced EndoMT. These findings were corroborated by bulk RNA-sequencing of DHH depleted HUVECs and endothelial lineage tracing in inducible DhhecKO mice. Mechanistically, DHH directly interacted with plasminogen activator inhibitor type 1 (PAI-1) and suppressed PAI-1-induced EndoMT. PAI-1 promoted EndoMT in ECs through activation of canonical TGF-{beta} signaling (SMAD2/3) and noncanonical AKT/ERK1/2 signaling via interaction with low-density lipoprotein receptor-related protein (LRP1). Neutralization of PAI-1 or inhibition of LRP1, AKT/ERK1/2, or SMAD3 signaling abolished DHH deficiency-induced EndoMT. DHH competitively inhibited PAI-1 binding to LRP1, thereby attenuating downstream pro-EndoMT signaling. Intriguingly, treatment with PAI-1 inhibitor TM5275 mitigated endothelial Dhh deficiency induced EndoMT in vivo. Of translational relevance, recombinant mouse DHH protein administration reduced atherosclerosis progression, stabilized plaque, and decreased the expression of EndoMT markers in ApoE knockout mice. CONCLUSIONSDesert hedgehog (DHH) is an intrinsic endothelial cell-enriched resilience factor that protects against EndoMT and atherosclerosis by preventing PAI-1 signaling. The present study implicates endothelial DHH as a potential therapeutic target for atherosclerotic cardiovascular disease. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/729715v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@194c8a3org.highwire.dtl.DTLVardef@1004d52org.highwire.dtl.DTLVardef@d47c73org.highwire.dtl.DTLVardef@368866_HPS_FORMAT_FIGEXP M_FIG C_FIG Desert hedgehog (DHH) is an intrinsic endothelial cell-enriched resilience factor that protects against EndoMT and atherosclerosis by preventing PAI-1 binding to LRP1 and downstream AKT/ERK, as well as SMAD2/3 signaling. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIDHH was identified as a flow-responsive resilience gene that is downregulated by disturbed flow in endothelial cells. C_LIO_LIEndothelial-specific deletion of Dhh promoted endothelial-to-mesenchymal transition (En-doMT) and atherosclerosis. C_LIO_LIDHH directly interacts with PAI-1 and preclude PAI-1 mediated pro-EndoMT signaling. C_LI What Are the Clinical Implications?O_LIDHH maintains endothelial homeostasis during atherosclerosis. C_LIO_LITargeting endothelial DHH-PAI-1 axis may represent a potential therapeutic strategy to reduce EndoMT and limit plaque progression. C_LIO_LILower circulating DHH level may serve as a potential biomarker of endothelial dysfunction and plaque vulnerability in atherosclerotic disease. C_LI

biochemistry↗

bioRxiv2023

Increased endothelium activation and leakage do not promote diastolic dysfunction in mice fed with a high fat diet and treated with L-NAME

Coronary microvascular disease has been proposed to be responsible for heart failure with preserved ejection fraction (HFpEF) about 10 years ago. However, to date the role and phenotype of the coronary microvasculature has still been poorly considered and investigated in animal models of HFpEF. ObjectiveTo determine whether endothelial dysfunction participates in the development of diastolic dysfunction in mice fed with a high fat diet (HDF) and treated with L-NAME. Approach and ResultsAt first, we thoroughly phenotyped the coronary microvasculature in this model in male, female and ovariectomized (OVX) female considering the sexual dimorphism associated with this disease. We found that both OVX and non OVX females but not males display increased endothelial activation, leakage, and arteriole constriction upon the HFD + L-NAME regimen while both male and OVX females but not non OVX females develop diastolic dysfunction. With the aim to investigate the role of endothelial dysfunction in the pathophysiology of diastolic dysfunction in OVX female mice, we used Cdon deficient mice. Indeed, we previously demonstrated that endothelium integrity, upon inflammatory conditions, is preserved in these mice. Both OVX Cdh5-Cre/ERT2-CdonFlox/Flox (CdonECKO) and CdonFlox/Flox (Ctrl) female mice were fed with the HFD + L-NAME regimen to induced diastolic dysfunction. As expected, CdonECKO mice displayed improved endothelium integrity i.e. decreased endothelium permeability, decreased ICAM-1 expression and decreased infiltration of CD45+ leukocytes in comparison to control mice. However, CdonECKO mice displayed cardiac hypertrophy, cardiac fibrosis and increased end diastolic pressure just like control mice. Moreover, we found that cardiac inflammation does not participate in the pathophysiology of HFpEF either by treating OVX female mice with colchicine. ConclusionAltogether, the data presented in this paper demonstrate that neither endothelium permeability nor endothelial activation or inflammation do participate in the pathophysiology of diastolic dysfunction in mice exposed to HFD+L-NAME.

pathology↗

bioRxiv2022

Cardiac pericytes are necessary for coronary vasculature integrity and cardiomyocyte differentiation

Introduction: While the critical role of pericytes in maintaining vascular integrity has been extensively demonstrated in the brain and in the retina, very little is known about their role in the heart. Objective: We aim to investigate structural and functional consequences of partial pericyte depletion (about 60%) in the heart of adult mice. Methods: To deplete pericyte in adult mice, we used Pdgfrb-Cre/ERT2; Rosa-DTA mice and compared their phenotype to the one of control mice (Rosa-DTA) chosen among their littermates. Cardiac function was assessed via echocardiography and left ventricle (LV) catheterization one month after the first tamoxifen injection. Results: Mice depleted with pericytes displayed increased coronary endothelium leakage and activation which was associated with increased CD45 + cell infiltration in the heart. Pericyte depletion also modified the phenotype of cardiomyocytes with an increased expression of Myosin Heavy Chain 7, a decreased expression of ATPase Sarcoplasmic/Endoplasmic Reticulum Ca2+ Transporting 2, Connexin 43 and a decreased phosphorylation of Phospholamban suggesting cardiomyocyte dedifferentiation and impaired contractility. As a consequence, mice depleted with pericytes had a reduced LV ejection fraction and an increased end-diastolic pressure demonstrating both systolic and diastolic dysfunction. Accordingly, mice depleted with pericytes presented a decreased LV contractility and an increased LV relaxation time (dP/dtmin). Besides this study reveals that cardiac pericytes may undergo strong remodeling upon injury. Conclusion: Cardiac pericyte depletion induces both systolic and diastolic dysfunction suggesting that pericyte dysfunction may contribute to the occurrence of cardiac diseases.

physiology↗

bioRxiv2020

Mast cells participate in the development of diastolic dysfunction in diabetic obese mice

Rational Heart failure with preserved ejection fraction (HFpEF) is a growing epidemiologic issue. However, to date, its pathophysiology remains poorly understood.Objective Our goal was to investigate the role of microvessel disease in the pathophysiology of diastolic dysfunction.Findings To do so, we used Leptin receptor deficient (Leprdb/db) female mice as a model of diastolic dysfunction. In these mice, the increased end diastolic pressure (EDP) signing diastolic dysfunction is associated with vascular leakage, endothelial cell activation and leucocyte infiltration. Strikingly, a RNA sequencing analysis of the cardiac vascular fraction of both Leprdb/db and control female mice confirmed endothelial dysfunction and systemic inflammation but also revealed a strong increase in several mast cell markers (notably FceR1a, Tryptase and Chymase). We then histologically confirmed an accumulation of activated mast cells in the heart of Leprdb/db mice. Importantly, mast cell degranulation inhibition reduced EDP, vascular leakage and leucocyte infiltration in Leprdb/db mice.Conclusion Mast cells play a critical role in the development of cardiac microvessel disease and diastolic dysfunction.Competing Interest StatementThe authors have declared no competing interest.View Full Text

physiology↗

bioRxiv2020

Desert Hedgehog-driven endothelium integrity is enhanced by Gas1 but negatively regulated by Cdon

Evidences accumulated within the past decades, identified Hedgehog (Hh) signaling as a new regulator of micro-vessel integrity. More specifically, we recently identified Desert Hedgehog (Dhh) as a downstream effector of Klf2 in endothelial cells (ECs). ObjectiveThe purpose of this study is to investigate whether Hh co-receptors Gas1 and Cdon may be used as therapeutic targets to modulate Dhh signaling in ECs. Methods and resultsWe demonstrated that both Gas1 and Cdon are expressed in adult ECs and relied on either siRNAs or EC specific conditional KO mice to investigate their role. We found that Gas1 deficiency mainly photocopies Dhh deficiency especially by inducing VCAM-1 and ICAM-1 overexpression while Cdon deficiency has opposite effects by promoting endothelial junction integrity. At a molecular level, Cdon prevents Dhh binding to Ptch1 and thus acts a decoy receptor for Dhh, while Gas1 promotes Dhh binding to Smo and as a result potentiates Dhh effects. Since Cdon is overexpressed in ECs treated by inflammatory cytokines including TNF and Il1{beta}, we then tested whether Cdon inhibition would promote endothelium integrity in acute inflammatory conditions and found that both fibrinogen and IgG extravasation were decreased in association with an increased Cdh5 expression in the brain cortex of EC specific Cdon KO mice administered locally with Il1{beta}. ConclusionAltogether these results demonstrate that Gas1 is a positive regulator of Dhh in ECs while Cdon is a negative regulator. Interestingly Cdon blocking molecules may then be used to promote endothelium integrity at least in inflammatory conditions.

cell biology↗

bioRxiv2020

Genetic disruption of the Blood Brain Barrier leads to protective barrier formation at the Glia Limitans

Recent work demonstrated that Central Nervous System (CNS) inflammation induces endothelial Blood Brain Barrier (BBB) opening as well as the formation of a tight junction barrier between reactive astrocytes at the Glia Limitans. We hypothesized that these two barriers may be reciprocally regulated by each other state and further, that the CNS parenchyma may acquire protection from the reactive astrocytic Glia Limitans not only in neuro-inflammation but also when BBB integrity is compromised under resting condition, without pathology. Previous studies identified Sonic hedgehog (Shh) astrocytic secretion as implicated in stabilizing the BBB during neuropathology and we recently demonstrated that desert hedgehog (Dhh) is expressed at the BBB in adults. Here we unraveled the role of the morphogen Dhh in maintaining BBB tightness and, using endothelial Dhh knockdown as a model of permeable BBB, we demonstrated that a double barrier system comprising both the BBB and Glia Limitans, is implemented in the CNS and regulated by a crosstalk going from endothelial cell to astrocytes. First, we showed that, under neuro-inflammatory conditions, Dhh expression is severely down regulated at the BBB and that Dhh is necessary for endothelial intercellular junction integrity as Dhh knockdown leads to CNS vascular leakage. We then demonstrated that, in Dhh endothelial knockout (DhhECKO) mice which display an open BBB, astrocytes are reactive and express the tight junction Claudin 4 (Cldn4) and showed that astrocytes can respond to signals secreted by the permeable endothelial BBB by becoming reactive and expressing Cldn4. To examine the consequences of the above results on disease severity, we finally induced multiple sclerosis in DhhECKO mice versus control littermates and showed that the pathology is less severe in the knockout animals due to Glia Limitans tightening, in response to BBB leakage, which drives inflammatory infiltrate entrapment into the perivascular space. Altogether these results suggest that genetic disruption of the BBB generates endothelial signals capable of driving the implementation of a secondary barrier at the Glia Limitans to protect the parenchyma. The concept of a reciprocally regulated CNS double barrier system has implications for treatment strategies in both the acute and chronic phases of multiple sclerosis pathophysiology.

neuroscience↗

bioRxiv2020

Endothelial cell response to Hedgehog ligands depends on their processing

RationaleThe therapeutic potential of Hedgehog (Hh) signaling agonists for vascular diseases is of growing interest. However, molecular and cellular mechanisms underlying the role of the Hh signaling in vascular biology remain poorly understood. ObjectiveThe purpose of the present paper is to clarify some conflicting literature data. FindingsWith this goal we have demonstrated that, unexpectedly, ectopically administered N-terminal Sonic Hedgehog (N-Shh) and endogenous endothelial-derived Desert Hedgehog (Dhh) induce opposite effects in endothelial cells. (ECs). Notably, endothelial Dhh acts under its full-length soluble form (FL-Dhh) and activates Smoothened in ECs, while N-Shh inhibits it. At molecular level, N-Shh prevents FL-Dhh binding to Patched-1 demonstrating that N-Shh acts as competitive antagonist to FL-Dhh. Besides, we found that even though FL-Hh ligands and N-Hh ligands all bind Patched-1, they induce specific Patched-1 localization. Finally, we confirmed that in a pathophysiological setting i.e. brain inflammation, astrocyte-derived N-Shh act as a FL-Dhh antagonist. ConclusionThe present study highlights for the first time that FL-Dhh and N-Hh ligands have antagonistic properties especially in ECs, and demonstrates that Hh ligands or forms of Hh ligands cannot be used instead of another for therapeutic purposes.

physiology↗