Pigment Epithelium-Derived Factor Mediates Autophagy and Apoptosis in Myocardial Hypoxia/Reoxygenation Injury

PLoS One. 2016 May 24;11(5):e0156059. doi: 10.1371/journal.pone.0156059. eCollection 2016.

Abstract

Pigment epithelium-derived factor (PEDF) is a multifunctional protein that exhibits anti-angiogenic, antitumor, anti-inflammatory, antioxidative, anti-atherogenic, and cardioprotective properties. While it was recently shown that PEDF expression is inhibited under low oxygen conditions, the functional role of PEDF in response to hypoxia/reoxygenation (H/R) remains unclear. The goal of this study was to therefore investigate the influence of PEDF on myocardial H/R injury. For these analyses, PEDF-specific small interfering RNA-expressing and PEDF-expressing lentivirus (PEDF-LV) vectors were utilized to knockdown or stably overexpress PEDF, respectively, within human cardiomyocytes (HCM) in vitro. We noted that reactive oxygen species (ROS) play important roles in the induction of cell death pathways, including apoptosis and autophagy in ischemic hearts. Our findings demonstrate that overexpression of PEDF resulted in a significant reduction in ROS production and attenuation of mitochondrial membrane potential depletion under H/R conditions. Furthermore, PEDF inhibited the activation of a two-step apoptotic pathway in which caspase-dependent (caspase-9 and caspase-3) and caspase-independent (apoptosis inducing factor and endonuclease G), which in turn cleaves several crucial substrates including the DNA repair enzyme poly (ADP-ribose) polymerase. Meanwhile, overexpression of PEDF also promoted autophagy, a process that is typically activated in response to H/R. Therefore, these findings suggest that PEDF plays a critical role in preventing H/R injury by modulating anti-oxidant and anti-apoptotic factors and promoting autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Autophagy
  • Caspases / metabolism
  • Cell Hypoxia
  • Cell Survival
  • Cells, Cultured
  • Eye Proteins / genetics*
  • Eye Proteins / metabolism*
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • Humans
  • Membrane Potential, Mitochondrial
  • Mitochondria / physiology*
  • Models, Biological
  • Myocytes, Cardiac / cytology*
  • Myocytes, Cardiac / metabolism
  • Nerve Growth Factors / genetics*
  • Nerve Growth Factors / metabolism*
  • Reactive Oxygen Species / metabolism*
  • Serpins / genetics*
  • Serpins / metabolism*

Substances

  • Eye Proteins
  • Nerve Growth Factors
  • Reactive Oxygen Species
  • Serpins
  • pigment epithelium-derived factor
  • Caspases

Grants and funding

This study was supported in part by grants from the Kaohsiung Medical University (KMUH102-2M18 and KMUH104-4M32), Kaohsiung Municipal Ta-Tung Hospital (KMTTH-103-10), China Medical University (CMU104-S-37), Taiwan Ministry of Science and Technology (MOST 104-2314-B-037-081-MY2, MOST 104-2314-B-037-087, and MOST 104-2320-B-039-016-MY3), and Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW105-TDU-B-212-133019). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.