Implications de la voie RhoA/Rho-kinases dans la physiopathologie des atteintes vasculaires et interstitielles pulmonaires des maladies respiratoires chroniques (études humaines et expérimentales chez la souris)

La voie RhoA/Rho-kinases (ROCK) joue un rôle important dans la physiopathologie de l hypertension pulmonaire (HTP) par son implication dans le dysfonctionnement endothélial, la constriction et le remodelage des vaisseaux pulmonaires. Selon les classifications internationales, la bronchopneumopathie chronique obstructive (BPCO) et la pneumopathie infiltrante diffuse (PID) sont deux causes fréquentes d HTP ayant en commun plusieurs mécanismes physiopathologiques dont le dysfonctionnement endothélial, le remodelage vasculaire et la fibrose parenchymateuse. Les objectifs de ce travail étaient d étudier le rôle de la voie RhoA/ROCK dans la physiopathologie de la BPCO et de la PID avec ou sans HTP et de préciser les anomalies moléculaires liées à la perturbation de la signalisation de cette voie dans chacune de ces situations.Le dysfonctionnement endothélial est un événement essentiel dans l initiation et la progression de la BPCO. L activation de la voie RhoA/ROCK dans le dysfonctionnement endothélial systémique et pulmonaire a été mise en évidence chez les tabagiques avec ou sans BPCO. Les résultats de notre première étude montrent l existence d une activation de la voie RhoA/ROCK au niveau des artères pulmonaires chez les patients BPCO ayant un dysfonctionnement endothélial, et une corrélation entre l activité de la RhoA et l expression génique et l activité de la NO synthase endothéliale (NOS-3).L HTP est une complication grave des PID. Nous avons montré dans notre deuxième étude l implication de la voie RhoA/ROCK dans la réponse inflammatoire et la fibrose pulmonaire (FP) dans un modèle murin de PID induite par injection intratrachéale de bléomycine (BLM). Nous avons ensuite testé l effet préventif du fasudil, un inhibiteur des ROCK, sur l apparition de la FP et l HTP expérimentales induites par la BLM. Les résultats de cette deuxième étude montrent que la FP et l HTP sont associées à une activation de la voie RhoA/ROCK dans ce modèle murin et que le fasudil inhibe la réponse inflammatoire, la FP et l HTP, via l inhibition de la phosphorylation de Smad2/3 de la voie de signalisation par le TGF-b1.La FP et l HTP représentent deux causes principales de mortalité liée à la sclérodermie systémique (ScS). Nous avons étudié le rôle de la voie RhoA/ROCK dans la physiopathologie de la fibrose cutanée et l atteinte pulmonaire dans un modèle murin de ScS induite par injection intradermique d acide hypochloreux (HOCl). Les résultats de cette troisième étude montrent l association entre la fibrose cutanée induite par l HOCl et l activation de la voie RhoA/ROCK au niveau de la peau, et l effet préventif du fasudil sur la fibrose cutanée et pulmonaire, en partie via l inhibition de la phosphorylation de Smad2/3 et de l activation des protéines ERK1/2. Ces résultats suggèrent l implication de la voie RhoA/ROCK dans la physiopathologie de la BPCO et de la PID avec ou sans HTP. La voie RhoA/ROCK pourrait de ce fait représenter une nouvelle cible thérapeutique dans la BPCO et la PID avec ou sans HTP.Mots-clés : RhoA, Rho-kinases, fasudil, BPCO, fibrose pulmonaire, hypertension pulmonaire.The RhoA/Rho-kinases (ROCK) pathway plays a pivotal role in the pathophysiology of pulmonary hypertension (PH) as its abnormal activation leads to endothelial dysfunction, sustained vasoconstriction and pulmonary vascular remodeling. According to the international classification of PH, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) represent two main causes of PH associated with chronic respiratory diseases. These two causes have in common major pathophysiological mechanisms such as endothelial dysfunction, vascular remodeling and interstitial fibrosis. The aims of the present study were to investigate the role of the RhoA/ROCK pathway in the pathophysiology of lung vascular and interstitial injuries in COPD and ILD with or without development of PH, and to study the molecular mechanisms associated with regulation of the RhoA/ROCK pathway in each of these situations.The pulmonary endothelial dysfunction is an essential event in the initiation and progression of COPD. Although the role of the RhoA/Rho-kinase pathway in pulmonary endothelial dysfunction has been demonstrated in smokers with normal lung function, little is known about its role in patients with COPD. The results of our first study demonstrated an increase in RhoA and ROCK activity in pulmonary arteries of patients with COPD, simultaneously with an altered pulmonary endothelial-dependent vasodilation. The increased RhoA activity in patients with COPD was correlated with an impairment of the gene expression and activity of endothelial NO synthase (eNOS).PH associated with pulmonary fibrosis (PF) considerably worsens prognosis of ILD. The results of our second study showed an activation of the RhoA/ROCK pathway in lung tissues of mice intoxicated by intratracheal instillation of bleomycin (BLM). BLM induced severe PF and PH in mice, associated with an increased RhoA and ROCK activity in the lung. We further demonstrated that long-term treatment with fasudil, a selective ROCK inhibitor, reduced BLM-induced lung inflammation, lung fibrosis and PH in mice, at least in part, via inhibition of Smad2/3 phosphorylation in TGF-b1 signaling.PF and PH represent two leading causes of death in patients with systemic sclerosis (SSc). In our third study, we investigated the role of the RhoA/ROCK pathway in the pathophysiology of skin fibrosis and lung injuries in a murine model of SSc induced by intradermal injection of hypochlorous acid (HOCl). We demonstrated that HOCl-induced skin fibrosis was associated with an activation of the RhoA/ROCK pathway in the fibrotic skin, and that long-term treatment with fasudil reduced both skin and lung fibrosis through inhibition of the phosphorylation of Smad2/3 and ERK1/2 in the fibrotic skin.These results suggest the implications of the RhoA/ROCK pathway in the pathophysiology of lung vascular and interstitial injuries in COPD and ILD with and without development of PH. The RhoA/ROCK pathway might be a promising therapeutic target for patients with COPD or ILD with and without PH.PARIS5-Bibliotheque electronique (751069902) / SudocSudocFranceF

Telocytes: New Connecting Devices in the Stromal Space of Organs

Telocytes (TCs) represent a new type of interstitial cells, and were discovered by Prof. Popescu and his collaborators from Bucharest in 2005, and described as Interstitial Cajal-Like Cells (ICLCs). In 2010, Prof. Popescu and Prof. Faussone-Pellegrini from Florence, based on their expertise in morphology, agreed that in fact ICLCs were a brand-new entity and they renamed them telocytes. TCs are characterized by specific veil- or ribbon-like extensions called telopodes. Telopodes aid TCs in forming homo- or hetero-cellular contacts; thus, assembling three-dimensional networks that organizes the stromal and the parenchymal components of the organs. TCs can transfer information to neighbor cells ensuring a short-distance communication, and remotely by the release a wide variety of extracellular vesicles: exosomes, ectosomes, and multivesicular bodies. Here, we reviewed the evolution of the interest regarding TCs in different organs, in normal and pathological conditions. The main focus was on the role of TCs in gastrointestinal tract, urinary bladder, reproductive tract, and heart. This chapter sums up information about the possibilities that TCs are capable to behave as sensors/mediators in nervous activity, to represent mesenchymal stem cell precursors in adulthood, and to control and determine the differentiation/maturation of other cell types either during development or in postnatal life

Crucial Role of miR-433 in Regulating Cardiac Fibrosis

Dysregulation of microRNAs has been implicated in many cardiovascular diseases including fibrosis. Here we report that miR-433 was consistently elevated in three models of heart disease with prominent cardiac fibrosis, and was enriched in fibroblasts compared to cardiomyocytes. Forced expression of miR-433 in neonatal rat cardiac fibroblasts increased proliferation and their differentiation into myofibroblasts as determined by EdU incorporation, α-SMA staining, and expression levels of fibrosis-associated genes. Conversely, inhibition of miR-433 exhibited opposite results. AZIN1 and JNK1 were identified as two target genes of miR-433. Decreased level of AZIN1 activated TGF-β1 while down-regulation of JNK1 resulted in activation of ERK and p38 kinase leading to Smad3 activation and ultimately cardiac fibrosis. Importantly, systemic neutralization of miR-433 or adeno-associated virus 9 (AAV9)-mediated cardiac transfer of a miR-433 sponge attenuated cardiac fibrosis and ventricular dysfunction following myocardial infarction. Thus, our work suggests that miR-433 is a potential target for amelioration of cardiac fibrosis

Crucial Role of miR-433 in Regulating Cardiac Fibrosis: Erratum

Corrected article: Theranostics 2016; 6(12): 2068-2083. doi: 10.7150/thno.1500

HIPK1 Inhibition Protects against Pathological Cardiac Hypertrophy by Inhibiting the CREB-C/EBPβ Axis

Inhibition of pathological cardiac hypertrophy is recognized as an important therapeutic strategy for heart failure, although effective targets are still lacking in clinical practice. Homeodomain interacting protein kinase 1 (HIPK1) is a conserved serine/threonine kinase that can respond to different stress signals, however, whether and how HIPK1 regulates myocardial function is not reported. Here, it is observed that HIPK1 is increased during pathological cardiac hypertrophy. Both genetic ablation and gene therapy targeting HIPK1 are protective against pathological hypertrophy and heart failure in vivo. Hypertrophic stress-induced HIPK1 is present in the nucleus of cardiomyocytes, while HIPK1 inhibition prevents phenylephrine-induced cardiomyocyte hypertrophy through inhibiting cAMP-response element binding protein (CREB) phosphorylation at Ser271 and inactivating CCAAT/enhancer-binding protein β (C/EBPβ)-mediated transcription of pathological response genes. Inhibition of HIPK1 and CREB forms a synergistic pathway in preventing pathological cardiac hypertrophy. In conclusion, HIPK1 inhibition may serve as a promising novel therapeutic strategy to attenuate pathological cardiac hypertrophy and heart failure

Implications of the RhoA/Rho-kinases pathway in the pathophysiology of lung vascular and interstitial injuries in chronic respiratory diseases : studies in human tissues and murine models

La voie RhoA/Rho-kinases (ROCK) joue un rôle important dans la physiopathologie de l’hypertension pulmonaire (HTP) par son implication dans le dysfonctionnement endothélial, la constriction et le remodelage des vaisseaux pulmonaires. Selon les classifications internationales, la bronchopneumopathie chronique obstructive (BPCO) et la pneumopathie infiltrante diffuse (PID) sont deux causes fréquentes d’HTP ayant en commun plusieurs mécanismes physiopathologiques dont le dysfonctionnement endothélial, le remodelage vasculaire et la fibrose parenchymateuse. Les objectifs de ce travail étaient d’étudier le rôle de la voie RhoA/ROCK dans la physiopathologie de la BPCO et de la PID avec ou sans HTP et de préciser les anomalies moléculaires liées à la perturbation de la signalisation de cette voie dans chacune de ces situations.Le dysfonctionnement endothélial est un événement essentiel dans l’initiation et la progression de la BPCO. L’activation de la voie RhoA/ROCK dans le dysfonctionnement endothélial systémique et pulmonaire a été mise en évidence chez les tabagiques avec ou sans BPCO. Les résultats de notre première étude montrent l’existence d’une activation de la voie RhoA/ROCK au niveau des artères pulmonaires chez les patients BPCO ayant un dysfonctionnement endothélial, et une corrélation entre l’activité de la RhoA et l’expression génique et l’activité de la NO synthase endothéliale (NOS-3).L’HTP est une complication grave des PID. Nous avons montré dans notre deuxième étude l’implication de la voie RhoA/ROCK dans la réponse inflammatoire et la fibrose pulmonaire (FP) dans un modèle murin de PID induite par injection intratrachéale de bléomycine (BLM). Nous avons ensuite testé l’effet préventif du fasudil, un inhibiteur des ROCK, sur l’apparition de la FP et l’HTP expérimentales induites par la BLM. Les résultats de cette deuxième étude montrent que la FP et l’HTP sont associées à une activation de la voie RhoA/ROCK dans ce modèle murin et que le fasudil inhibe la réponse inflammatoire, la FP et l’HTP, via l’inhibition de la phosphorylation de Smad2/3 de la voie de signalisation par le TGF-β1.La FP et l’HTP représentent deux causes principales de mortalité liée à la sclérodermie systémique (ScS). Nous avons étudié le rôle de la voie RhoA/ROCK dans la physiopathologie de la fibrose cutanée et l’atteinte pulmonaire dans un modèle murin de ScS induite par injection intradermique d’acide hypochloreux (HOCl). Les résultats de cette troisième étude montrent l’association entre la fibrose cutanée induite par l’HOCl et l’activation de la voie RhoA/ROCK au niveau de la peau, et l’effet préventif du fasudil sur la fibrose cutanée et pulmonaire, en partie via l’inhibition de la phosphorylation de Smad2/3 et de l’activation des protéines ERK1/2. Ces résultats suggèrent l’implication de la voie RhoA/ROCK dans la physiopathologie de la BPCO et de la PID avec ou sans HTP. La voie RhoA/ROCK pourrait de ce fait représenter une nouvelle cible thérapeutique dans la BPCO et la PID avec ou sans HTP.Mots-clés : RhoA, Rho-kinases, fasudil, BPCO, fibrose pulmonaire, hypertension pulmonaire.The RhoA/Rho-kinases (ROCK) pathway plays a pivotal role in the pathophysiology of pulmonary hypertension (PH) as its abnormal activation leads to endothelial dysfunction, sustained vasoconstriction and pulmonary vascular remodeling. According to the international classification of PH, chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) represent two main causes of PH associated with chronic respiratory diseases. These two causes have in common major pathophysiological mechanisms such as endothelial dysfunction, vascular remodeling and interstitial fibrosis. The aims of the present study were to investigate the role of the RhoA/ROCK pathway in the pathophysiology of lung vascular and interstitial injuries in COPD and ILD with or without development of PH, and to study the molecular mechanisms associated with regulation of the RhoA/ROCK pathway in each of these situations.The pulmonary endothelial dysfunction is an essential event in the initiation and progression of COPD. Although the role of the RhoA/Rho-kinase pathway in pulmonary endothelial dysfunction has been demonstrated in smokers with normal lung function, little is known about its role in patients with COPD. The results of our first study demonstrated an increase in RhoA and ROCK activity in pulmonary arteries of patients with COPD, simultaneously with an altered pulmonary endothelial-dependent vasodilation. The increased RhoA activity in patients with COPD was correlated with an impairment of the gene expression and activity of endothelial NO synthase (eNOS).PH associated with pulmonary fibrosis (PF) considerably worsens prognosis of ILD. The results of our second study showed an activation of the RhoA/ROCK pathway in lung tissues of mice intoxicated by intratracheal instillation of bleomycin (BLM). BLM induced severe PF and PH in mice, associated with an increased RhoA and ROCK activity in the lung. We further demonstrated that long-term treatment with fasudil, a selective ROCK inhibitor, reduced BLM-induced lung inflammation, lung fibrosis and PH in mice, at least in part, via inhibition of Smad2/3 phosphorylation in TGF-β1 signaling.PF and PH represent two leading causes of death in patients with systemic sclerosis (SSc). In our third study, we investigated the role of the RhoA/ROCK pathway in the pathophysiology of skin fibrosis and lung injuries in a murine model of SSc induced by intradermal injection of hypochlorous acid (HOCl). We demonstrated that HOCl-induced skin fibrosis was associated with an activation of the RhoA/ROCK pathway in the fibrotic skin, and that long-term treatment with fasudil reduced both skin and lung fibrosis through inhibition of the phosphorylation of Smad2/3 and ERK1/2 in the fibrotic skin.These results suggest the implications of the RhoA/ROCK pathway in the pathophysiology of lung vascular and interstitial injuries in COPD and ILD with and without development of PH. The RhoA/ROCK pathway might be a promising therapeutic target for patients with COPD or ILD with and without PH