Type 2 Diabetes Inhibited Human Mesenchymal Stem Cells Angiogenic Response by Over-Activity of the Autophagic Pathway.

The current study aimed to address the impact of serum from type 2 diabetes patients on the angiogenic properties of human bone marrow mesenchymal stem cells and its relationship to autophagy signaling. Human primary stem cells were enriched and incubated with serum from diabetic and normal subjects for 7 days. Compared to data from the control group, diabetic serum was found to induce a higher cellular death rate (P < 0.001) and apoptotic changes (P < 0.01). We also showed that diabetic condition significantly abolished angiogenesis tube formation on Matrigel substrate, decreased cell chemotaxis (P < 0.01) in response to SDF-1α, and inhibited endothelial differentiation rate (P < 0.0001). Western blotting showed autophagic status by high levels of P62 (P < 0.0001), beclin-1 (P < 0.0001), and increase in LC3II/I ratio (P < 0.001). In vivo Matrigel plug assay revealed that supernatant conditioned media prepared from cells exposed to diabetic serum caused a marked reduction in the recruitment of VE-cadherin- (P < 0.01) and α-SMA-positive (P < 0.0001) cells 7 days after subcutaneous injection. PCR expression array analysis confirmed the overexpression of autophagy and apoptosis genes in cultured cells in response to a diabetic condition (P < 0.05). Using bioinformatic analysis, we noted a crosstalk network between DM2, angiogenesis, and autophagy signaling. DM2 could potently modulate angiogenesis by the interaction of IL-1β with downstream insulin receptor and upstream androgen receptor. Corroborating to data, diabetic serum led to abnormal regulation of P62 during the angiogenic response. These data demonstrate that diabetic serum decreased human mesenchymal stem cell angiogenic properties directly on angiogenesis pathways or by the induction of autophagy signaling. J. Cell. Biochem. 118: 1518-1530, 2017.