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

• Published in: PloS one 2015-05, Vol.10 (5), p.e0126715-e0126715
• Main Authors: Liu, Jiejie, Hao, Haojie, Xia, Lei, Ti, Dongdong, Huang, Hong, Dong, Liang, Tong, Chuan, Hou, Qian, Zhao, Yali, Liu, Huiling, Fu, Xiaobing, Han, Weidong
• Format: Article
• Language: English
• Subjects: Angiogenesis; Angiogenesis Inducing Agents - metabolism; Angiography; Animals; Apoptosis; Bcl-2 protein; Bone marrow; Care and treatment; Cell proliferation; Cell Survival; Cells, Cultured; Complications and side effects; Cytokines; Diabetes; Diabetes mellitus; Diabetes Mellitus, Experimental; Diabetic retinopathy; Disease Models, Animal; Endothelial cells; Endothelial Cells - metabolism; Gelatinase B; Gene expression; Hospitals; Human Umbilical Vein Endothelial Cells; Humans; Hyperglycemia; Hypoxia; Hypoxia - metabolism; Immunofluorescence; Immunohistochemistry; Ischemia; Ischemia - etiology; Ischemia - metabolism; Life sciences; Lower Extremity - blood supply; Lower Extremity - diagnostic imaging; Male; Medicine; Mesenchymal Stem Cell Transplantation; Mesenchymal stem cells; Mesenchymal Stromal Cells - metabolism; Mesenchyme; Metabolism; Muscles; Neovascularization, Pathologic - metabolism; Oxygen; Physiology; Polymerase chain reaction; Polyvinyl alcohol; Proto-Oncogene Proteins c-akt - metabolism; Rats; Reconstruction; Risk factors; Rodents; Signal Transduction; Stem cell transplantation; Stem cells; Survival; Tracer experiments; Transplantation; Ultrasonography; Vascular endothelial growth factor; Vascular endothelial growth factor receptors; Vascular Endothelial Growth Factors - metabolism; Western blotting
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0126715

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.