Hypoxia preconditioning promotes bone marrow mesenchymal stem cells survival by inducing HIF-1α in injured neuronal cells derived exosomes culture system

Cell Death Dis. 2019 Feb 12;10(2):134. doi: 10.1038/s41419-019-1410-y.

Abstract

Bone marrow derived stem cells (BMSCs) transplantation are viewed as a promising therapeutic candidate for spinal cord injury (SCI). However, the inflammatory microenvironment in the spinal cord following SCI limits the survival and efficacy of transplanted BMSCs. In this study, we investigate whether injured neuronal cells derived exosomes would influence the survival of transplanted BMSCs after SCI. In order to mimic the microenvironment in SCI that the neuronal cells or transplanted BMSCs suffer in vivo, PC12 cells conditioned medium and PC12 cell's exosomes collected from H2O2-treated PC12 cell's culture medium were cultured with BMSCs under oxidative stress in vitro. PC12 cells conditioned medium and PC12 cell's exosomes significantly accelerated the apoptosis of BMSCs induced by H2O2. Moreover, the cleaved caspase-3, cytochrome (Cyt) C, lactate dehydrogenase (LDH) releases, and apoptotic percentage were increased, and the ratio of Bcl-2/Bax and cell viability were decreased. Inhibition of exosome secretion via Rab27a small interfering RNA prevented BMSCs apoptosis in vitro. In addition, hypoxia-preconditioned promoted the survival of BMSCs under oxidative stress both in vivo after SCI and in vitro. Our results also indicate that HIF-1α plays a central role in the survival of BMSCs in hypoxia pretreatment under oxidative stress conditions. siRNA-HIF-1α increased apoptosis of BMSCs; in contrast, HIF-1α inducer FG-4592 attenuated apoptosis of BMSCs. Taken together, we found that the injured PC12 cells derived exosomes accelerate BMSCs apoptosis after SCI and in vitro, hypoxia pretreatment or activating expression of HIF-1α to be important in the survival of BMSCs after transplantation, which provides a foundation for application of BMSCs in therapeutic potential for SCI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Cell Hypoxia / drug effects*
  • Cell Survival / drug effects
  • Culture Media, Conditioned
  • Disease Models, Animal
  • Exosomes / metabolism*
  • Hydrogen Peroxide / pharmacology
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Male
  • Mesenchymal Stem Cell Transplantation*
  • Mesenchymal Stem Cells / metabolism*
  • Neurons / metabolism*
  • PC12 Cells
  • RNA, Small Interfering / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Spinal Cord Injuries / metabolism*
  • Spinal Cord Injuries / therapy
  • rab27 GTP-Binding Proteins / genetics

Substances

  • Culture Media, Conditioned
  • Hif1a protein, rat
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Small Interfering
  • rab27 GTP-Binding Proteins
  • Hydrogen Peroxide
  • Rab27a protein, rat