title: ATP stimulates PGE(2)/cyclin D1-dependent VSMCs proliferation via STAT3 activation: role of PKCs-dependent NADPH oxidase/ROS generation.
abstract: Vascular smooth muscle cells (VSMCs) that function as synthetic units play important roles in cardiovascular diseases. Extracellular nucleotides, such as ATP, have been shown to act via activation of P2 purinoceptors implicated in various inflammatory diseases, we hypothesized that extracellular nucleotides contribute to vascular diseases via up-regulation of inflammatory proteins, including cyclooxygenase-2 (COX-2) and cytosolic phospholipase A2 (cPLA2) in VSMCs. However, the mechanisms of ATP-induced cPLA2 and COX-2 expression and PGE2 synthesis remain largely unclear. We showed that pretreatment with the inhibitors of STAT3 (CBE), NADPH oxidase [diphenyleneiodonium chloride (DPI) or apocynin (APO)], ROS [N-acetyl-l-cysteine (NAC)], and PKC (Ro-318220, Gö6983, or Rottlerin) or transfection with siRNAs of STAT3 and p47(phox) markedly inhibited ATPγS-induced cPLA2 and COX-2 mRNA/protein expression and promoter activity and PGE2 secretion. ATPγS further stimulated PKC, p47(phox), and STAT3 translocation. Moreover, ATPγS-induced STAT3 phosphorylation and translocation was inhibited by pretreatment with the inhibitors of PKC, NADPH oxidase, and ROS. ATPγS enhanced NADPH oxidase activity and ROS generation in VSMCs, which were reduced by pretreatment with Ro-318220, Gö6983, or Rottlerin. Finally, we found that ATPγS significantly induced cyclin D1 expression and VSMCs proliferation, which were inhibited by pretreatment with NAC, APO, DPI, Ro-318220, Gö6983, Rottlerin, or CBE or transfection with siRNAs of COX-2 and cyclin D1. We also demonstrated that ATPγS induced cyclin D1 expression via a PGE2-dependent pathway. These results suggested that ATPγS-induced cPLA2/COX-2 expression and PGE2 secretion is mediated through a PKC/NADPH oxidase/ROS/STAT3-dependent pathway in VSMCs.
authors: Department of Anesthetics, Chang Gung Memorial Hospital at Linkuo and Chang Gung University, Kwei-San, Tao-Yuan, Taiwan.
authors: I-Ta
authors: IT
authors: Lee
authors: Chih-Chung
authors: CC
authors: Lin
authors: Chao-Hung
authors: CH
authors: Wang
authors: Wen-Jin
authors: WJ
authors: Cherng
authors: Jong-Shyan
authors: JS
authors: Wang
authors: Chuen-Mao
authors: CM
authors: Yang
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000502:physiology*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D008297:Male; D009097:Multienzyme Complexes / Q000096:biosynthesis*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis*; D054467:Phospholipases A2 / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D009097:Multienzyme Complexes; D017382:Reactive Oxygen Species; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D019938:Cyclin D1; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D011493:Protein Kinase C; D054467:Phospholipases A2