Vincent SAUZEAU - Academia.edu (original) (raw)

Papers by Vincent SAUZEAU

Hypertension, 2016

Introduction: Renal ischemia/reperfusion (IR) is a major cause of acute kidney injury (AKI). The ... more Introduction: Renal ischemia/reperfusion (IR) is a major cause of acute kidney injury (AKI). The benefit of novel non-steroidal MR antagonists such as finerenone in the IR context has not been evaluated and the mechanisms underlying the benefit of MR antagonism remain unclear. Objectives: To test the efficacy of finerenone in ischemic AKI and to evaluate the specific contribution of the MR expressed in endothelial or smooth muscle cell (SMC) in renal IR injury. Methods: We included 18 male C57/B6 mice that were divided in: sham, renal ischemia for 20 min and IR plus treatment with finerenone (10 mg/kg) by gavage once a day at -48, -24 and -1 h before IR. Alternatively, MR inactivation in endothelial cells (MR endoKO mice /Vecadh-cre) or in smooth muscle cells (MR SMCKO mice/SMA-cre) was induced in 3-month-old mice. Sham surgery or bilateral renal IR for 20 min was performed and mice were studied 24 h after reperfusion. Primary rat SMC cultures were used to assess the signaling pathw...

Revue des Maladies Respiratoires, 2022

Asthma is a chronic airway condition defined by hyperresponsiveness, bronchial remodeling and chr... more Asthma is a chronic airway condition defined by hyperresponsiveness, bronchial remodeling and chronic inflammation. A significant proportion of severe asthmatic patients remain uncontrolled despite recent therapeutic breakthroughs (biotherapies). Better understanding of the signaling pathways involved in the pathophysiological mechanisms underlying severe asthma could successfully address this unmet need. Rac GTPase acts as a molecular switch and has already been convincingly associated with airway hyperresponsiveness and bronchial remodeling in asthma. Having been elucidated by acquired knowledge regarding other pathologies. Its role in the inflammation mechanisms characterizing asthma is currently under specific evaluation.

Thorax, 2021

BackgroundSevere asthma is a chronic lung disease characterised by inflammation, airway hyperresp... more BackgroundSevere asthma is a chronic lung disease characterised by inflammation, airway hyperresponsiveness (AHR) and airway remodelling. The molecular mechanisms underlying uncontrolled airway smooth muscle cell (aSMC) proliferation involved in pulmonary remodelling are still largely unknown. Small G proteins of the Rho family (RhoA, Rac1 and Cdc42) are key regulators of smooth muscle functions and we recently demonstrated that Rac1 is activated in aSMC from allergic mice. The objective of this study was to assess the role of Rac1 in severe asthma-associated airway remodelling.Methods and resultsImmunofluorescence analysis in human bronchial biopsies revealed an increased Rac1 activity in aSMC from patients with severe asthma compared with control subjects. Inhibition of Rac1 by EHT1864 showed that Rac1 signalling controlled human aSMC proliferation induced by mitogenic stimuli through the signal transducer and activator of transcription 3 (STAT3) signalling pathway. In vivo, speci...

Frontiers in Immunology, 2020

Asthma is a chronic airway disease often due to sensitization to aeroallergens, especially house ... more Asthma is a chronic airway disease often due to sensitization to aeroallergens, especially house dust mite allergens (HDMs). The Dermatophagoides pteronyssinus group 2 (Der p 2), is one of the most representative HDM allergens and is recognized by more than 90% of HDM-allergic patients. In mouse models, all asthma-related features can be prevented by prophylactic administration of Dermatophagoides pteronyssinus 2-derived peptide (Der p 2.1). However, it is unknown whether it is able to treat well-established asthma in mice and humans. We aimed here to evaluate the efficacy of Der p 2.1 immunotherapy in a mouse, humanized mouse, and asthmatic patients. Asthma related-features were analyzed through airway hyperresponsiveness (AHR), allergen-specific IgE, and lung histology in mice and humanized mice. Immune profile was analyzed using lung and blood from mice and severe asthmatic patients respectively. T cell and dendritic cell (DC) polarization was evaluated using co-culture of bone marrow derived cells (BMDCs) and naïve T cell from naïve mice. Mice and humanized mice both have a reduced AHR, lung tissue alteration, and HDM-specific IgE under Der p 2.1 treatment. Concerning the immune profile, T helper 2 cells (Th2) and T helper 17 cells (Th17) were significantly reduced in both mice and humanized mice lung and in peripheral blood mononuclear cells (PBMCs) from severe asthmatic patients after Der p 2.1 incubation. The downregulation of T cell polarization seems to be linked to an increase of IL-10-secreting DC under Der p 2.1 treatment in both mice and severe asthmatic patients. This study shows that allergenderived peptide immunotherapy abrogates asthma-related features in mice and humanized mice by reducing Th2 and Th17 cells polarization via IL-10-secreting DC. These results suggest that Der p 2.1 peptide immunotherapy could be a promising approach to treat both Th2 and Th17 immunity in asthma.

Revue Française d'Allergologie, 2018

Molecular Pathology and Funct. Genomics, 2018

Journal of Allergy and Clinical Immunology, 2018

PLCβ2 PIP 2 DAG Sarcoplasmic reticulum IP 3 IP 3 Rc Ca 2+ Ca 2+ PLC Rac1 GTP Ca 2+-CAM MLCK MLCP ... more PLCβ2 PIP 2 DAG Sarcoplasmic reticulum IP 3 IP 3 Rc Ca 2+ Ca 2+ PLC Rac1 GTP Ca 2+-CAM MLCK MLCP MLC 20 MLC 20-p Airway hyperresponsiveness Airway smooth muscle GPCR Allergic asthma NSC23766 Targeting of Rac1 prevents bronchoconstriction and airway hyperresponsiveness Background: The molecular mechanisms responsible for airway smooth muscle cells' (aSMCs) contraction and proliferation in airway hyperresponsiveness (AHR) associated with asthma are still largely unknown. The small GTPases of the Rho family (RhoA, Rac1, and Cdc42) play a central role in SMC functions including migration, proliferation, and contraction. Objective: The objective of this study was to identify the role of Rac1 in aSMC contraction and to investigate its involvement in AHR associated with allergic asthma. Methods: To define the role of Rac1 in aSMC, ex and in vitro analyses of bronchial reactivity were performed on bronchi from smooth muscle (SM)-specific Rac1 knockout mice and From a NSERM, CNRS, UNIV Nantes, l'institut du thorax and b CHU Nantes, Nantes.

American Journal of Physiology-Heart and Circulatory Physiology, 2000

In the cardiovascular system, activation of ionotropic (P2X receptors) and metabotropic (P2Y rece... more In the cardiovascular system, activation of ionotropic (P2X receptors) and metabotropic (P2Y receptors) P2 nucleotide receptors exerts potent and various responses including vasodilation, vasoconstriction, and vascular smooth muscle cell proliferation. Here we examined the involvement of the small GTPase RhoA in P2Y receptor-mediated effects in vascular myocytes. Stimulation of cultured aortic myocytes with P2Y receptor agonists induced an increase in the amount of membrane-bound RhoA and stimulated actin cytoskeleton organization. P2Y receptor agonist-induced actin stress fiber formation was inhibited by C3 exoenzyme and the Rho kinase inhibitor Y-27632. Stimulation of actin cytoskeleton organization by extracellular nucleotides was also abolished in aortic myocytes expressing a dominant negative form of RhoA. Extracellular nucleotides induced contraction and Y-27632-sensitive Ca2+sensitization in aortic rings. Transfection of Swiss 3T3 cells with P2Y receptors showed that Rho kina...

Archives of Cardiovascular Diseases Supplements, 2017

Arterial fibrosis and stiffness are characterized by vascular smooth muscle cells (SMC) prolifera... more Arterial fibrosis and stiffness are characterized by vascular smooth muscle cells (SMC) proliferation. These hyperplasic processes involved inflammation as well as disrupted flow contributing to vascular remodeling in hypertension and intimal hyperplasia after angioplasty. Our previous results have identified phosphoinositide 3-kinase gamma (PI3Kg), a GPCR activated PI3K, as an essential actor of inflammatory processes in arterial wall. In this work, we identified for the first time a key role of PI3Kg in SMC proliferation through a kinase independent mechanism. Indeed, using a flow induced arterial remodeling model we showed that absence of PI3Kg (PI3Kg KO) in mice leads to decreased medial hyperplasia whereas absence of PI3Kg activity (PI3Kg KD for kinase dead) did not. We then investigate molecular mechanism involved in primary aortic SMC. We showed that forskolin induced higher elevation of cAMP in PI3Kg-KO genotype compared to PI3Kg-KD and WT cells indicating that PI3Kg could modulate degradation of this nucleotide through a catalytic independent function. Analysis of phosphodiesterase activity in PI3Kg-KO, PI3Kg-KD and WT SMC cells showed that absence of PI3Kg was responsible for a decrease in phosphodiesterase (PDE) 4 isoforms activity. Moreover, loss of PI3Kg expression in SMC potentiated the regulation effect of forskolin on SMC proliferation. Finally, we develop a novel therapeutic strategy using a permeant peptide able to interact with PDE complex and blocks docking function of PI3Kg. This peptide prevented SMC proliferation in vitro in presence of forskolin as we observed in absence of PI3Kg. In vivo, local delivery of this peptide decreased flow induced medial SMC hyperplasia in WT mice confirming the importance of PI3Kg docking function in SMC proliferation. These data provide evidence for a novel role of PI3Kg in arterial remodeling through PDE 4 activation in smooth muscle cells and reveal novel strategies targeting non catalytic function of PI3Kg.

Stem Cells, 2016

Mesenchymal stem cell (MSC) immunosuppressive functions make them attractive candidates for anti-... more Mesenchymal stem cell (MSC) immunosuppressive functions make them attractive candidates for anti-inflammatory therapy in allergic asthma. However, the mechanisms by which they ensure therapeutic effects remain to be elucidated. In an acute mouse model of house dust mite (Der f)-induced asthma, one i.v. MSC injection was sufficient to normalize and stabilize lung function in Der f-sensitized mice as compared to control mice. MSC injection decreased in vivo airway responsiveness and decreased ex vivo carbachol-induced bronchial contraction, maintaining bronchial expression of the inhibitory type 2 muscarinic receptor. To evaluate in vivo MSC survival, MSCs were labeled with PKH26 fluorescent marker prior to i.v. injection, and 1 to 10 days later total lungs were digested to obtain single-cell suspensions. 91.5 ± 2.3% and 86.6 ± 6.3% of the recovered PKH26+ lung cells expressed specific macrophage markers in control and Der f mice, respectively, suggesting that macrophages had phagocyt...

Archives of Cardiovascular Diseases Supplements, 2014

The Journal of allergy and clinical immunology, Jan 30, 2015

Physiological Reviews, 2013

Small G proteins exist in eukaryotes from yeast to human and constitute the Ras superfamily compr... more Small G proteins exist in eukaryotes from yeast to human and constitute the Ras superfamily comprising more than 100 members. This superfamily is structurally classified into five families: the Ras, Rho, Rab, Arf, and Ran families that control a wide variety of cell and biological functions through highly coordinated regulation processes. Increasing evidence has accumulated to identify small G proteins and their regulators as key players of the cardiovascular physiology that control a large panel of cardiac (heart rhythm, contraction, hypertrophy) and vascular functions (angiogenesis, vascular permeability, vasoconstriction). Indeed, basal Ras protein activity is required for homeostatic functions in physiological conditions, but sustained overactivation of Ras proteins or spatiotemporal dysregulation of Ras signaling pathways has pathological consequences in the cardiovascular system. The primary object of this review is to provide a comprehensive overview of the current progress i...

Journal of Biological Chemistry, 2003

The small G protein RhoA is a convergence point for multiple signals that regulate smooth muscle ... more The small G protein RhoA is a convergence point for multiple signals that regulate smooth muscle cell functions. NO plays a major role in the structure and function of the normal adult vessel wall, mainly through modulation of gene transcription. This study was thus performed to analyze in vitro and in vivo the effect of NO signaling on RhoA expression in arterial smooth muscle cells. In rat or human artery smooth muscle cells, sodium nitroprusside or 8-(2-chlorophenylthio)-cGMP induced a rise in RhoA mRNA and protein expression, which was inhibited by the cGMP-dependent protein kinase (PKG) inhibitor (R p)-8-bromo-␤-phenyl-1,N 2-ethenoguanosine 3:5-phosphorothioate. The NO/PKG stimulation of RhoA expression involved both an increase in RhoA protein stability and stimulation of rhoA gene transcription. Cloning and functional analysis of the human rhoA promoter revealed that the effect of NO/ PKG involved phosphorylation of ATF-1 and subsequent binding to the cAMP-response element. Chronic inhibition of NO synthesis in N-nitro-L-arginine-treated rats induced a strong decrease in RhoA mRNA and protein expression in aorta and pulmonary artery associated with inhibition of RhoA-mediated Ca 2؉ sensitization. These effects were prevented by oral administration of the cGMP phosphodiesterase inhibitor sildenafil. These results show that NO/PKG signaling positively controls RhoA expression and suggest that the basal release of NO is necessary to maintain RhoA expression and RhoAdependent functions in vascular smooth muscle cells.

Gastroenterology, 2003

Background & Aims: Rho proteins are involved in the regulation of several cellular functions. Dat... more Background & Aims: Rho proteins are involved in the regulation of several cellular functions. Data from in vitro studies suggest that RhoA could be involved in the inflammatory response. We investigated the role of RhoA and its downstream effector Rho kinase in intestinal inflammation. Methods: Activation of RhoA was assessed by pull-down assays. A specific inhibitor of Rho kinase, Y-27632, was used to examine the role of Rho kinase in inflammatory response in vivo and in vitro by molecular biology and by immunological and biochemical approaches. Results: Increased activation of RhoA was found in inflamed intestinal mucosa of patients with Crohn's disease and of rats with 2,4,6-trinitrobenzene sulfonic acid-induced colitis. Oral administration of Y-27632 in rats significantly reduced the colonic inflammation. In vitro, activation of RhoA alone was sufficient to induce tumor necrosis factor production. Y-27632 inhibited production of tumor necrosis factor-␣ and interleukin-1␤ by lamina propria and peripheral blood mononuclear cells. Rho kinase inhibition prevented nuclear factor B activation and I-B phosphorylation and degradation. We showed that Rho kinase associates with and activates I-B kinase ␣ and that Y-27632 prevents I-B kinase activation. Conclusions: Our study provides the first evidence that Rho kinase activates I-B kinase and, thus, nuclear factor B, suggesting a key role of Rho kinase in inflammatory responses and intestinal inflammation. Specific inhibition of Rho kinase may be a promising approach for the treatment of patients with Crohn's disease.

Circulation Research, 2003

Exposure to chronic hypoxia (CH) induces a sustained pulmonary hypertension associated with struc... more Exposure to chronic hypoxia (CH) induces a sustained pulmonary hypertension associated with structural and functional changes in the pulmonary arterial bed, including alterations of contractile properties. The small G-protein RhoA and its effector Rho kinase play a major role in the sustained rise in tension induced by vasoconstrictors. The aim of this study was to analyze the effect of CH on the RhoA/Rho kinase signaling pathway in the rat pulmonary artery. Maximal contraction of pulmonary artery rings to endothelin-1, noradrenaline, and the thromboxane A2 analog U46619 was markedly decreased in rats exposed to CH (10% O 2 , 2 weeks). This CH-induced decrease response to agonists was attributable to the abolition of RhoA-mediated Ca 2+ sensitization of the contraction. Real-time reverse transcriptase–polymerase chain reaction and Western blot analysis revealed a decrease in RhoA mRNA (79.4±6.0%, n=4) and RhoA (81.1±8.0%, n=4) expression in the main pulmonary artery from CH rats, wh...

Circulation Research, 2005

cAMP and cyclic GMP-dependent kinases (PKA and PKG) phosphorylate the small G protein RhoA on Ser... more cAMP and cyclic GMP-dependent kinases (PKA and PKG) phosphorylate the small G protein RhoA on Ser188. We have previously demonstrated that phosphorylation of Ser188 inhibits RhoA-dependent functions and positively regulates RhoA expression, and that the nitric oxide (NO)/cGMP-dependent protein kinase pathway plays an essential role, both in vitro and in vivo, in the regulation of RhoA protein expression and functions in vascular smooth muscle cells. Here we analyze the consequences of Ser188 phosphorylation on RhoA protein degradation. By expressing Ser188 phosphomimetic wild-type (WT-RhoA-S188E) and active RhoA proteins (Q63L-RhoA-S188E), we show that phosphorylation of Ser188 of RhoA protects RhoA, particularly its active form, from ubiquitin-mediated proteasomal degradation. Coimmunoprecipitation experiments indicate that the resistance of the phosphorylated active form of RhoA to proteasome-mediated degradation is because of its cytoplasmic sequestration through enhanced RhoGDI ...

Archives of Cardiovascular Diseases Supplements, 2020

British Journal of Pharmacology, 2005

Inhibition of the type 5 phosphodiesterase and inhibition of Rho kinase are both effective in red... more Inhibition of the type 5 phosphodiesterase and inhibition of Rho kinase are both effective in reducing pulmonary hypertension (PH). Here we investigate whether Rho kinase inhibition is involved in the beneficial effect of the type 5 phosphodiesterase inhibitor sildenafil on PH. Chronic hypoxia-induced PH in rats is associated with an increase in RhoA activity in pulmonary artery that was maximal after 2 days (10.7+/-0.9-fold increase, n=6, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The activity of Rho kinase assessed by measuring the level of myosin phosphatase target subunit 1 (MYPT1) phosphorylation was also increased (5.7+/-0.8-fold over control, n=8). Chronic fasudil (30 mg kg(-1) day(-1); 14 days) and sildenafil (25 mg kg(-1) day(-1); 14 days) treatments reduced PH and pulmonary cardiovascular remodelling, and inhibited the MYPT1 phosphorylation in pulmonary artery from hypoxic rats by 82.3+/-3% (n=4) and by 76.6+/-2% (n=4), respectively. The inhibitory effect of sildenafil (10 microM) on MYPT1 phosphorylation was demonstrated by the loss of actin stress fibres in vascular smooth muscle cells. However, in vitro kinase assays indicated that sildenafil had no direct inhibitory action on Rho kinase activity. Sildenafil treatment induced increased RhoA phosphorylation and association to its cytosolic inhibitory protein, guanine dissociation inhibitor (GDI) in pulmonary artery.We propose that sildenafil inhibits RhoA/Rho kinase-dependent functions in pulmonary artery through enhanced RhoA phosphorylation and cytosolic sequestration by GDI. The inhibition of intracellular events downstream of RhoA thus participates in the beneficial effect of sildenafil on PH.