title: Involvement of TRPV1 and TRPV4 channels in migration of rat pulmonary arterial smooth muscle cells.
abstract: Pulmonary hypertension, the main disease of the pulmonary circulation, is characterized by an increase in pulmonary vascular resistance, involving proliferation and migration of pulmonary arterial smooth muscle cells (PASMC). However, cellular and molecular mechanisms underlying these phenomena remain to be identified. In the present study, we thus investigated in rat intrapulmonary arteries (1) the expression and the functional activity of TRPV1 and TRPV4, (2) the PASMC migration triggered by these TRPV channels, and (3) the associated reorganization of the cytoskeleton. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated expression of TRPV1 and TRPV4 mRNA in rat intrapulmonary arteries. These results were confirmed at the protein level by western blot. Using microspectrofluorimetry (indo-1), we show that capsaicin and 4α-phorbol-12,13-didecanoate (4α-PDD), selective agonists of TRPV1 and TRPV4, respectively, increased the intracellular calcium concentration of PASMC. Furthermore, stimulation of TRPV1 and TRPV4 induced PASMC migratory responses, as assessed by two different methods (a modified Boyden chamber assay and a wound-healing migration assay). This response cannot seem to be attributed to a proliferative effect as assessed by BrdU and Wst-1 colorimetric methods. Capsaicin- and 4α-PDD-induced calcium and migratory responses were inhibited by the selective TRPV1 and TRPV4 blockers, capsazepine and HC067047, respectively. Finally, as assessed by immunostaining, these TRPV-induced migratory responses were associated with reorganization of the F-actin cytoskeleton and the tubulin and intermediate filament networks. In conclusion, these data point out, for the first time, the implication of TRPV1 and TRPV4 in rat PASMC migration, suggesting the implication of these TRPV channels in the physiopathology of pulmonary hypertension.
authors: Centre de Recherche Cardio-Thoracique de Bordeaux, Univ Bordeaux, 33076, Bordeaux, France.
authors: Elodie
authors: E
authors: Martin
authors: Diana
authors: D
authors: Dahan
authors: Guillaume
authors: G
authors: Cardouat
authors: Jennifer
authors: J
authors: Gillibert-Duplantier
authors: Roger
authors: R
authors: Marthan
authors: Jean-Pierre
authors: JP
authors: Savineau
authors: Thomas
authors: T
authors: Ducret
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000031:analogs & derivatives / Q000494:pharmacology; D002465:Cell Movement; D003599:Cytoskeleton / Q000502:physiology; D009025:Morpholines / Q000494:pharmacology; D032389:Myocytes, Smooth Muscle / Q000502:physiology*; D010703:Phorbol Esters / Q000494:pharmacology; D011651:Pulmonary Artery / Q000166:cytology / Q000502:physiology*; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D050916:TRPV Cation Channels / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: C573308:HC-067047; D009025:Morpholines; D010703:Phorbol Esters; D011758:Pyrroles; D012333:RNA, Messenger; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; C486577:Trpv4 protein, rat; C008876:phorbol-12,13-didecanoate; C071423:capsazepine; D002211:Capsaicin; D002118:Calcium