NAD(P)H oxidase-dependent intracellular and extracellular O-2(center dot-) production in coronary arterial myocytes from CD38 knockout mice

作者：Xu Ming; Zhang Yang; Xia Min; Li Xiao Xue; Ritter Joseph K; Zhang Fan; Li Pin Lan^*

来源：Free Radical Biology and Medicine, 2012, 52(2): 357-365.

DOI：10.1016/j.freeradbiomed.2011.10.485

• ADP-ribose
• Ca2+
• Redox signaling
• Artery
• Vasoconstriction
• Coronary circulation
• Free radicals

Activation of NAD(P)H oxidase has been reported to produce superoxide (O-2(center dot-)) extracellularly as an autocrine/paracrine regulator or intracellularly as a signaling messenger in a variety of mammalian cells. However, it remains unknown how the activity of NAD(P)H oxidase is regulated in arterial myocytes. Recently, CD38-associated ADP-ribosylcyclase has been reported to use an NAD(P)H oxidase product, NAD(+) or NADP(+), to produce cyclic ADP-ribose (cADPR) or nicotinic acid adenine dinucleotide phosphate, which mediates intracellular Ca2+ signaling. This study was designed to test a hypothesis that the CD38/cADPR pathway as a downstream event exerts feedback regulatory action on the NAD(P)H oxidase activity in production of extra- or intracellular O-2(center dot-) in mouse coronary arterial myocytes (CAMs). By fluorescence microscopic imaging, we simultaneously monitored extra- and intracellular O-2(center dot-) production in wild-type (CD38(+/+)) and CD38 knockout (CD38(-/-)) CAMs in response to oxotremorine (OXO), a muscarinic type 1 receptor agonist. It was found that CD38 deficiency prevented OXO-induced intracellular but not extracellular O-2(center dot-) production in CAMs. Consistently, the OXO-induced intracellular O-2(center dot-) production was markedly inhibited by CD38 shRNA or the CD38 inhibitor nicotinamide in CD38(+/+) CAMs. Further, Nox4 siRNA inhibited OXO-induced intracellular but not extracellular O-2(center dot-) production, whereas Nox1 siRNA attenuated both intracellular and extracellular O-2(center dot-) production in CD38(+/+) CAMs. Direct delivery of exogenous cADPR into CAMs markedly elevated intracellular Ca2+ and O-2(center dot-) production in CD38(-/-) CAMs, Functionally, CD38 deficiency or Nox1 siRNA and Nox4 siRNA prevented OXO-induced contraction in isolated perfused coronary arteries in CD38 WT mice. These results provide direct evidence that the CD38/cADPR pathway is an important controller of Nox4-mediated intracellular O-2(center dot-) production and that CD38-dependent intracellular O-2(center dot-) production is augmented in an autocrine manner by CD38-independent Nox1-derived extracelkilar O-2(center dot-) production in CAMs.

• 出版日期2012-1-15