The role of ERK1/2 in 15-HETE-inhibited apoptosis in pulmonary arterial smooth muscle cells

J Recept Signal Transduct Res. 2011 Feb;31(1):45-52. doi: 10.3109/10799893.2010.512013. Epub 2010 Sep 8.

Abstract

15-Hydroxyeicosatetrenoic acid (15-HETE) is an important product of arachidonic acid catalyzed by 15-lipoxygenase (15-LO) in the wall of pulmonary vessels, which plays a key role in pulmonary arterial hypertension. The previous studies showed that 15-HETE inhibits apoptosis. It is still unknown, however, whether 15-HETE acts on the apoptotic responses through the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. The aim of the study is to test the hypothesis that ERK1/2 pathway participates in the protective effects of 15-HETE on the cell survival. This hypothesis was validated by cell viability measurement, nuclear morphology determination, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, mitochondrial potentials assay and Western blot. We found that 15-HETE enhanced cell survival, suppressed the expression of phosphatase and tensin homologue deleted on chromosome ten, upregulated X-linked inhibitor of apoptosis protein and Bcl-2 and attenuated mitochondrial depolarization in pulmonary artery muscle smooth cells (PASMCs) under serum-deprived conditions. These effects were reversed by ERK1/2 inhibitor PD98059. Taken together, our data indicated that the ERK1/2 kinase is a regulator of PASMC apoptosis, and potential therapeutical strategy for pulmonary hypertension may be developed by targeting at intracellular signaling systems centered by the kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Cell Survival / drug effects
  • Enzyme Activation / drug effects
  • Hydroxyeicosatetraenoic Acids / pharmacology*
  • In Situ Nick-End Labeling
  • MAP Kinase Signaling System / drug effects
  • Male
  • Membrane Potential, Mitochondrial / drug effects
  • Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Myocytes, Smooth Muscle / cytology*
  • Myocytes, Smooth Muscle / drug effects
  • Myocytes, Smooth Muscle / enzymology*
  • PTEN Phosphohydrolase / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Pulmonary Artery / cytology*
  • Rats
  • Rats, Wistar
  • X-Linked Inhibitor of Apoptosis Protein / metabolism

Substances

  • Hydroxyeicosatetraenoic Acids
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins c-bcl-2
  • X-Linked Inhibitor of Apoptosis Protein
  • 15-hydroxy-5,8,11,13-eicosatetraenoic acid
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • PTEN Phosphohydrolase