Big mitogen-activated protein kinase 1 protects cultured rat aortic smooth muscle cells from oxidative damage

J Pharmacol Sci. 2011;116(2):173-80. doi: 10.1254/jphs.11015fp. Epub 2011 May 19.

Abstract

Oxidative stress is considered a major mediator of arteriosclerosis. In vascular smooth muscle cells, oxidative stress-induced cell death (including apoptosis) is probably related to arterial calcification in arteriosclerosis. Big mitogen-activated protein kinase-1 / extracellular signal-regulated kinase 5 (BMK1/ERK5) is a newly identified member of the mitogen-activated protein kinases family. Like Src tyrosine kinase, BMK1/ERK5 is known to be sensitive to oxidative stress; however, its pathophysiological significance is poorly understood. In this study, we investigated the involvement of BMK1 and Src in H(2)O(2)-induced cell death using cultured rat aortic smooth muscle cells (RASMCs). Cell apoptosis was evaluated by using the TdT-mediated dUTP nick end labeling (TUNEL) method, and BMK1 and Src activities were determined by Western blotting. The main results are as follows: 1) BMK1 and Src were activated by H(2)O(2) in a time- and concentration-dependent manner in RASMCs; 2) BMK1 activation by H(2)O(2) was attenuated both in Src-knockdown RASMCs and in RASMCs pretreated with 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), a Src family kinases inhibitor; and 3) H(2)O(2)-induced cell death was increased in BMK1- and Src-knockdown RASMCs as well as in PP2-treated RASMCs. These findings suggested that Src and BMK1 may play defensive and resistive roles against oxidative stress-induced death in RASMCs.

MeSH terms

  • Animals
  • Aorta / drug effects
  • Aorta / enzymology
  • Aorta / metabolism*
  • Base Sequence
  • Blotting, Western
  • Cells, Cultured
  • DNA Primers
  • Enzyme Activation
  • Hydrogen Peroxide / pharmacology
  • Mitogen-Activated Protein Kinase 7 / genetics
  • Mitogen-Activated Protein Kinase 7 / metabolism*
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / enzymology
  • Muscle, Smooth, Vascular / metabolism*
  • Oxidative Stress*
  • RNA, Small Interfering
  • Rats
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / metabolism

Substances

  • DNA Primers
  • RNA, Small Interfering
  • Hydrogen Peroxide
  • src-Family Kinases
  • Mitogen-Activated Protein Kinase 7