Genipin inhibits TNF-α-induced vascular smooth muscle cell proliferation and migration via induction of HO-1

PLoS One. 2013 Aug 27;8(8):e74826. doi: 10.1371/journal.pone.0074826. eCollection 2013.

Abstract

Vascular smooth muscle cell (VSMC) proliferation and migration triggered by inflammatory stimuli contributes importantly to the pathogenesis of atherosclerosis and restenosis. On the other hand, genipin, an aglycon of geniposide, exhibits diverse pharmacological functions such as antitumor and anti-inflammatory effects. The protective effects of genipin on the cardiovascular system have also been reported. However, the molecular mechanism involved remains unknown. This study aimed to elucidate the precise function of genipin in VSMCs, focusing particularly on the role of heme oxygenase-1 (HO-1), a potent anti-inflammatory enzyme. We found that pretreatment of genipin induced HO-1 mRNA and protein levels, as well as its activity in VSMCs. Genipin inhibited TNF-α-induced VSMC proliferation and migration in a dose-dependent manner. At the molecular level, genipin prevented ERK/MAPK and Akt phosphorylation while left p38 MAPK and JNK unchanged. Genipin also blocked the increase of ROS generation induced by TNF-α. More importantly, the specific HO-1 siRNA partially abolished the beneficial effects of genipin on VSMCs. These results suggest that genipin may serve as a novel drug in the treatment of these pathologies by inducing HO-1 expression/activity and subsequently decreasing VSMC proliferation and migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects*
  • Cholagogues and Choleretics / pharmacology*
  • Enzyme Induction / drug effects
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Heme Oxygenase-1 / biosynthesis*
  • Iridoids / pharmacology*
  • Male
  • Muscle, Smooth, Vascular / metabolism*
  • Muscle, Smooth, Vascular / pathology
  • Myocytes, Smooth Muscle / metabolism*
  • Myocytes, Smooth Muscle / pathology
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Cholagogues and Choleretics
  • Iridoids
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • genipin
  • Heme Oxygenase-1
  • Proto-Oncogene Proteins c-akt
  • Extracellular Signal-Regulated MAP Kinases

Grants and funding

This work was supported by grants from the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and Qing-Lan Project of Jiangsu Province. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.