title: Arginase I attenuates inflammatory cytokine secretion induced by lipopolysaccharide in vascular smooth muscle cells.
abstract: OBJECTIVE
  Inflammation plays an important role in atherosclerosis. Arginase I (Arg I) promotes the proliferation of vascular smooth muscle cells; however, the effect of Arg I on inflammation remains unknown. The present study investigated the role of Arg I in inflammation in vitro and in vivo.
  
  
  RESULTS
  Quantitative reverse transcription-polymerase chain reaction and Western blot analysis demonstrated that Arg I inhibited tumor necrosis factor-α production induced by lipopolysaccharide in human aortic smooth muscle cells. Inducible nitric oxide synthase substrate competition and nuclear factor-κB activation were main contributors to lipopolysaccharide-mediated inflammatory cytokine generation. However, Arg I could attenuate the function of inducible nitric oxide synthase and inhibit the subsequent nuclear factor-κB activation, leading to inhibition of tumor necrosis factor-α generation. Furthermore, upregulation of Arg I significantly decreased macrophage infiltration and inflammation in atherosclerotic plaque of rabbits, whereas downregulation of Arg I aggravated these adverse effects.
  
  
  CONCLUSIONS
  The results indicate the antiinflammatory effects of Arg I and suggest an unexpected beneficial role of Arg I in inflammatory disease.
authors: Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Shandong University, Qilu Hospital, Jinan, China.
authors: Xu-ping
authors: XP
authors: Wang
authors: Yu-guo
authors: YG
authors: Chen
authors: Wei-dong
authors: WD
authors: Qin
authors: Wei
authors: W
authors: Zhang
authors: Shu-jian
authors: SJ
authors: Wei
authors: Juan
authors: J
authors: Wang
authors: Fu Qiang
authors: FQ
authors: Liu
authors: Lei
authors: L
authors: Gong
authors: Feng Shuang
authors: FS
authors: An
authors: Yun
authors: Y
authors: Zhang
authors: Zhe-Yu
authors: ZY
authors: Chen
authors: Ming-Xiang
authors: MX
authors: Zhang