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Consequence of Desmin gene mutation on development of chronic hypoxic pulmonary hypertension in mice
202 pulmonary edema without affecting right ventricular weight and fibrosis. Data obtained by cardiac MRI are currently being analysed. Conclusion These preliminary results demonstrate that sEH inhibition improves pulmonary endothelial function in rats with heart failure, which could contribute to the beneficial effects of this new pharmacological class in the context of left heart diseases. Acknowledgement This work was co-supported by European Union and Région Normandie. Europe gets involved in Normandie with European Regional Development Fund (ERDF) Disclosure of interest The authors declare that they have no competing interest https://doi.org/10.1016/j.acvdsp.2019.02.044 276
Short-term mechanisms activated by the nerve growth factor NGF to induce pulmonary arterial hyperreactivity G. Cardouat ∗ , M. Douard , P. Robillard , M. Dubois , R. Marthan , B. Muller , C. Guibert , V. Freund-Michel Centre de Recherche Cardio-Thoracique de Bordeaux, Inserm U1045 Université de Bordeaux, Pessac, France ∗ Corresponding author. E-mail address: [email protected] (G. Cardouat) Introduction We have previously shown that the nerve growth factor (NGF) induces pulmonary arterial (PA) hyperreactivity, but our preliminary experiments have shown that the mechanisms activated by NGF seem to differ depending on a short-term or a long-term PA treatment. Aim To characterize the mechanisms activated by NGF to induce PA hyperreactivity after a short-term treatment (1 h). Methods Contractions of control rat pulmonary arteries were induced ex vivo by phenylephrine (PHE, 10-10-10-5 M) or endothelin1 (ET-1, 10-12-10-6 M) in the absence or presence of NGF (100 ng/ml, 1 h), with or without K252a (TrkA kinase inhibitor, 300 nM) or Y27632 (ROCK inhibitor, 10 M). NGF-induced phosphorylation of myosin phosphatase target subunit 1 (MYPT1) was evaluated in vitro by Western blotting in primary human PA smooth muscle cells (hPASMC). Calcium intracellular concentrations were evaluated in vitro in primary rat PA smooth muscle cells (rPASMC) using calcium imaging (Indo-1, Fluo-4), in the absence or presence of NGF (100 ng/ml, 1 h), with or without PHE (10-6 M) or ET-1 (10-7 M). Results Ex vivo, short-term treatment with NGF increases rat PA reactivity to PHE and ET-1. This effect is totally abolished after treatment with K252a or Y-27632. In vitro, short-term treatment with NGF induces MYPT1 phosphorylation in hPASMC and increases basal intracellular calcium concentration in rPASMC. In addition, pre-treatment with NGF (1 h) increases calcium responses of these cells to PHE and ET-1. Conclusions These results show that NGF induces PA hyperreactivity in the short-term through activation of its TrkA receptor, modulation of calcium intracellular concentrations (either basal or agonist-stimulated) and sensitization mechanisms involving the ROCK pathway. These mechanisms differ from those activated by NGF to induce PA hyperreactivity in the long-term. Disclosure of interest The authors declare that they have no competing interest. https://doi.org/10.1016/j.acvdsp.2019.02.045
Topic 6 - Hypertension 310
Consequence of Desmin gene mutation on development of chronic hypoxic pulmonary hypertension in mice S. Abid 1 , A. Houssaini 1 , E. Born 1 , J. Ternacle 1 , Y. Hovhannisyan 2 , D. Beaulieu 1 , E. Marcos 1 , Z. Li 2 , R. Marthan 3 , O. Agbulut 2 , G. Derumeaux 1 , S. Adnot 1 , C. Guibert 3 , L. Lipskaia 1,∗ 1 Inserm U955 Equipe 8, Université Paris-Est Créteil (UPEC), Créteil 2 CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), 75005 Paris 3 Inserm U1045, F-33076, Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Bordeaux, France ∗ Corresponding author. E-mail address: [email protected] (L. Lipskaia) Introduction Desmin deficiency is responsible for various forms of skeletal and cardiac disorders. However, role of desmin in the normal and pathological pulmonary vasculature remains unknown. Objective To investigate whether desmin deficiency affects pulmonary circulation in normoxic and hypoxic conditions. Methods Desmin-deficient mice (Des-/-) and their littermate Des+/+ (controls) aged 2—4 months were exposed to chronic hypoxia (9% O2, 2 weeks) or normoxia. Cardiac function was assessed by closed-chest echocardiography and right ventricle (RV) hemodynamics combined with measurements of Fulton Index and muscularization of pulmonary arteries (PA). Contractile properties of intrapulmonary arteries were measured by using an arteriography. Heart and lung phenotype were determined by using standard techniques of histology, immunostaining, immunoblot and RT-qPCR analysis. Results Under normal conditions Des-/- mice developed cardiomyopathy with alteration of both left ventricle (LV) and RV functions. Left Heart Disease was characterized by ventricular dilatation, decreased Ejection Fraction and Strain Rate in agreement with extreme transmural fibrosis and cardiomyocytes hypertrophy. RV dysfunction was evidenced by an increase of RV systolic pressure (RVSP) and PA muscularization. After exposure to hypoxia, LV function was globally not modified in both Des/- and Des+/+ mice. RV was similarly affected in both strains, though the increase of RV weight, RVSP and PA muscularization were higher in Des-/- mice. Conversely, contractile capacities of PA were not modified in Des-/- mice in normoxia. Under hypoxia, we recorded modifications of several contractile, structural and Ca2 ± handling proteins in PA - smooth muscle cells (SMC). Conclusion Our results indicate that desmin can be replaced by vimentin in SMC without loss of function. However, clinical features of desminopathies can also include pulmonary hypertension with PA remodeling and higher RV dysfunction. Disclosure of interest The authors declare that they have no competing interest. https://doi.org/10.1016/j.acvdsp.2019.02.046
Short-term mechanisms activated by the nerve growth factor NGF to induce pulmonary arterial hyperreactivity G. Cardouat ∗ , M. Douard , P. Robillard , M. Dubois , R. Marthan , B. Muller , C. Guibert , V. Freund-Michel Centre de Recherche Cardio-Thoracique de Bordeaux, Inserm U1045 Université de Bordeaux, Pessac, France ∗ Corresponding author. E-mail address: [email protected] (G. Cardouat) Introduction We have previously shown that the nerve growth factor (NGF) induces pulmonary arterial (PA) hyperreactivity, but our preliminary experiments have shown that the mechanisms activated by NGF seem to differ depending on a short-term or a long-term PA treatment. Aim To characterize the mechanisms activated by NGF to induce PA hyperreactivity after a short-term treatment (1 h). Methods Contractions of control rat pulmonary arteries were induced ex vivo by phenylephrine (PHE, 10-10-10-5 M) or endothelin1 (ET-1, 10-12-10-6 M) in the absence or presence of NGF (100 ng/ml, 1 h), with or without K252a (TrkA kinase inhibitor, 300 nM) or Y27632 (ROCK inhibitor, 10 M). NGF-induced phosphorylation of myosin phosphatase target subunit 1 (MYPT1) was evaluated in vitro by Western blotting in primary human PA smooth muscle cells (hPASMC). Calcium intracellular concentrations were evaluated in vitro in primary rat PA smooth muscle cells (rPASMC) using calcium imaging (Indo-1, Fluo-4), in the absence or presence of NGF (100 ng/ml, 1 h), with or without PHE (10-6 M) or ET-1 (10-7 M). Results Ex vivo, short-term treatment with NGF increases rat PA reactivity to PHE and ET-1. This effect is totally abolished after treatment with K252a or Y-27632. In vitro, short-term treatment with NGF induces MYPT1 phosphorylation in hPASMC and increases basal intracellular calcium concentration in rPASMC. In addition, pre-treatment with NGF (1 h) increases calcium responses of these cells to PHE and ET-1. Conclusions These results show that NGF induces PA hyperreactivity in the short-term through activation of its TrkA receptor, modulation of calcium intracellular concentrations (either basal or agonist-stimulated) and sensitization mechanisms involving the ROCK pathway. These mechanisms differ from those activated by NGF to induce PA hyperreactivity in the long-term. Disclosure of interest The authors declare that they have no competing interest. https://doi.org/10.1016/j.acvdsp.2019.02.045
Topic 6 - Hypertension 310
Consequence of Desmin gene mutation on development of chronic hypoxic pulmonary hypertension in mice S. Abid 1 , A. Houssaini 1 , E. Born 1 , J. Ternacle 1 , Y. Hovhannisyan 2 , D. Beaulieu 1 , E. Marcos 1 , Z. Li 2 , R. Marthan 3 , O. Agbulut 2 , G. Derumeaux 1 , S. Adnot 1 , C. Guibert 3 , L. Lipskaia 1,∗ 1 Inserm U955 Equipe 8, Université Paris-Est Créteil (UPEC), Créteil 2 CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), 75005 Paris 3 Inserm U1045, F-33076, Université de Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux (CRCTB), Bordeaux, France ∗ Corresponding author. E-mail address: [email protected] (L. Lipskaia) Introduction Desmin deficiency is responsible for various forms of skeletal and cardiac disorders. However, role of desmin in the normal and pathological pulmonary vasculature remains unknown. Objective To investigate whether desmin deficiency affects pulmonary circulation in normoxic and hypoxic conditions. Methods Desmin-deficient mice (Des-/-) and their littermate Des+/+ (controls) aged 2—4 months were exposed to chronic hypoxia (9% O2, 2 weeks) or normoxia. Cardiac function was assessed by closed-chest echocardiography and right ventricle (RV) hemodynamics combined with measurements of Fulton Index and muscularization of pulmonary arteries (PA). Contractile properties of intrapulmonary arteries were measured by using an arteriography. Heart and lung phenotype were determined by using standard techniques of histology, immunostaining, immunoblot and RT-qPCR analysis. Results Under normal conditions Des-/- mice developed cardiomyopathy with alteration of both left ventricle (LV) and RV functions. Left Heart Disease was characterized by ventricular dilatation, decreased Ejection Fraction and Strain Rate in agreement with extreme transmural fibrosis and cardiomyocytes hypertrophy. RV dysfunction was evidenced by an increase of RV systolic pressure (RVSP) and PA muscularization. After exposure to hypoxia, LV function was globally not modified in both Des/- and Des+/+ mice. RV was similarly affected in both strains, though the increase of RV weight, RVSP and PA muscularization were higher in Des-/- mice. Conversely, contractile capacities of PA were not modified in Des-/- mice in normoxia. Under hypoxia, we recorded modifications of several contractile, structural and Ca2 ± handling proteins in PA - smooth muscle cells (SMC). Conclusion Our results indicate that desmin can be replaced by vimentin in SMC without loss of function. However, clinical features of desminopathies can also include pulmonary hypertension with PA remodeling and higher RV dysfunction. Disclosure of interest The authors declare that they have no competing interest. https://doi.org/10.1016/j.acvdsp.2019.02.046