title: BMP4 increases canonical transient receptor potential protein expression by activating p38 MAPK and ERK1/2 signaling pathways in pulmonary arterial smooth muscle cells.
abstract: Abnormal bone morphogenetic protein (BMP) signaling has been implicated in the pathogenesis of pulmonary hypertension. We previously found that BMP4 elevated basal intracellular Ca(2+) ([Ca(2+)]i) concentrations in distal pulmonary arterial smooth muscle cells (PASMCs), attributable in large part to enhanced store-operated Ca(2+) entry through store-operated Ca(2+) channels (SOCCs). Moreover, BMP4 up-regulated the expression of canonical transient receptor potential (TRPC) proteins thought to compose SOCCs. The present study investigated the signaling pathways through which BMP4 regulates TRPC expression and basal [Ca(2+)]i in distal PASMCs. Real-time quantitative PCR was used for the measurement of mRNA, Western blotting was used for the measurement of protein, and fluorescent microscopic for [Ca(2+)]i was used to determine the involvement of p38 and extracellular regulated kinase (ERK)-1/2 mitogen-activated protein kinase (MAPK) signaling in BMP4-induced TRPC expression and the elevation of [Ca(2+)]i in PASMCs. We found that the treatment of BMP4 led to the activation of both p38 MAPK and ERK1/2 in rat distal PASMCs. The induction of TRPC1, TRPC4, and TRPC6 expression, and the increases of [Ca(2+)]i caused by BMP4 in distal PASMCs, were inhibited by treatment with either SB203580 (10 μM), the selective inhibitor for p38 activation, or the specific p38 small interfering RNA (siRNA). Similarly, those responses induced by BMP4 were also abolished by treatment with PD98059 (5 μM), the selective inhibitor of ERK1/2, or by the knockdown of ERK1/2 using its specific siRNA. These results indicate that BMP4 participates in the regulation of Ca(2+) signaling in PASMCs by modulating TRPC channel expression via activating p38 and ERK1/2 MAPK pathways.
authors.affiliation: State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.forename: Wenju
authors.initials: W
authors.lastname: Lu
authors.forename: Xin
authors.initials: X
authors.lastname: Fu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.forename: Nanshan
authors.initials: N
authors.lastname: Zhong
authors.forename: Pixin
authors.initials: P
authors.lastname: Ran
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D055785:Gene Knockdown Techniques; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008297:Male; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009124:Muscle Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011651:Pulmonary Artery / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D050052:TRPC Cation Channels / Q000096:biosynthesis* / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: C525811:Bmp4 protein, rat; D055415:Bone Morphogenetic Protein 4; D005419:Flavonoids; D009124:Muscle Proteins; D047428:Protein Kinase Inhibitors; D050052:TRPC Cation Channels; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium