CD38 Mediates Angiotensin II-Induced Intracellular Ca super( 2+) Release in Rat Pulmonary Arterial Smooth Muscle Cells

• Published in: American journal of respiratory cell and molecular biology Vol. 52; no. 3; p. 332
• Main Authors: Lee, Suengwon, Paudel, Omkar, Jiang, Yongliang, Yang, Xiao-Ru, Sham, James S K
• Format: Journal Article
• Language: English
• Published: 01.03.2015
• ISSN: 1535-4989

CD38 is a multifunctional enzyme that catalyzes the formation of the endogenous Ca super( 2+)-mobilizing messengers cyclic ADP-ribose (cADPR) and nicotinic acid adenosine dinucleotide phosphate (NAADP) for the activation of ryanodine receptors (RyRs) of sarcoplasmic reticulum and NAADP-sensitive Ca super( 2+) release channels in endolysosomes, respectively. It plays important roles in systemic vascular functions, but there is little information on CD38 in pulmonary arterial smooth muscle cells (PASMC). This study sought to characterize its roles in angiotensin II (Ang II)-induced Ca super( 2+) release (AICR) in PASMCs. Examination of CD38 expression in various rat arteries found high levels of CD38 mRNA and protein in pulmonary arteries. The Ang II-elicited Ca super( 2+) response consisted of extracellular Ca super( 2+) influx and intracellular Ca super( 2+) release in PASMCs. AICR activated in the absence of extracellular Ca super( 21) was reduced by pharmacological or siRNA inhibition of CD38, by the cADPR antagonist 8-bromocADPR or ryanodine, and by the NAADP antagonist Ned-19 or disruption of endolysosomal Ca super( 2+) stores with the vacuolar H super( 1+) ATPase inhibitor bafilomycin A1.