Hypoxia pretreatment of bone marrow mesenchymal stem cells facilitates angiogenesis by improving the function of endothelial cells in diabetic rats with lower ischemia

PLoS One. 2015 May 21;10(5):e0126715. doi: 10.1371/journal.pone.0126715. eCollection 2015.

Abstract

Endothelial dysfunction induced by unordered metabolism results in vascular reconstruction challenges in diabetic lower limb ischemia (DLLI). Mesenchymal stem cells (MSCs) are multipotent secretory cells that are suitable for clinical DLLI treatment, but their use has been hampered by poor survival after injection. Hypoxia can significantly enhance the capacity of MSCs to secrete angiogenic factors. We investigated transient hypoxia pretreatment of MSCs to facilitate revascularization in DLLI. Rat bone marrow MSCs (BM-MSCs) were cultured at different oxygen concentrations for varying time periods. The results indicated that transient pretreatment (5% O2, 48 h) not only increased the expression of VEGF-1α, ANG, HIF-1α and MMP-9 in BM-MSCs as assessed by real-time RT-PCR, but also increased the expression of Bcl-2 as determined by western blotting. The transplantation of pretreated BM-MSCs into rats with DLLI demonstrated accelerated vascular reconstruction when assayed by angiography and immunohistochemistry. CM-Dil-labeled tracer experiments indicated that the survival of BM-MSCs was significantly improved, with approximately 5% of the injected cells remaining alive at 14 days. The expression levels of VEGF-1α, MMP-9 and VEGF-R were significantly increased, and the expression of pAKT was up-regulated in ischemic muscle. Double immunofluorescence studies confirmed that the pretreated BM-MSCs promoted the proliferation and inhibited the apoptosis of endothelial cells. In vitro, pretreated BM-MSCs increased the migratory and tube forming capacity of endothelial cells (ECs). Hypoxia pretreatment of BM-MSCs significantly improved angiogenesis in response to tissue ischemia by ameliorating endothelial cell dysfunction and is a promising therapeutic treatment for DLLI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inducing Agents / metabolism
  • Angiography
  • Animals
  • Apoptosis
  • Cell Survival
  • Cells, Cultured
  • Diabetes Mellitus, Experimental
  • Disease Models, Animal
  • Endothelial Cells / metabolism*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hypoxia / metabolism*
  • Ischemia / etiology
  • Ischemia / metabolism*
  • Lower Extremity / blood supply*
  • Lower Extremity / diagnostic imaging
  • Male
  • Mesenchymal Stem Cell Transplantation
  • Mesenchymal Stem Cells / metabolism*
  • Neovascularization, Pathologic / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Signal Transduction
  • Ultrasonography
  • Vascular Endothelial Growth Factors / metabolism

Substances

  • Angiogenesis Inducing Agents
  • Vascular Endothelial Growth Factors
  • Proto-Oncogene Proteins c-akt

Grants and funding

This research was supported in part by the National Basic Science and Development Program (2012CB518103, 2012CB518105), the 863 Projects of Ministry of Science and Technology of China (2013AA020105 and 2012AA020502), National Natural Science Foundation of China (81121004, and 81230041),key sciences and technology project in hainan province (ZDZX2013003).