Paracrine interleukin-8 affects mesenchymal stem cells through the Akt pathway and enhances human umbilical vein...

Interleukin-8 (IL-8) promotes cell homing and angiogenesis, but its effects on activating human bone marrow mesenchymal stem cells (BMSCs) and promoting angiogenesis are unclear. We used bioinformatics to predict these processes. In vitro, BMSCs were stimulated in a high-glucose (HG) environment with 50 or 100 μg/ml IL-8 was used as the IL-8 group. A total of 5 μmol/l Triciribine was added to the two IL-8 groups as the Akt inhibitor group. Cultured human umbilical vein endothelial cells (HUVECs) were cultured in BMSCs conditioned medium (CM). The changes in proliferation, apoptosis, migration ability and levels of VEGF and IL-6 in HUVECs were observed in each group. Seventy processes and 26 pathways were involved in vascular development, through which IL-8 affected BMSCs. Compared with the HG control group, HUVEC proliferation absorbance value (A value), Gap closure rate, and Transwell cell migration rate in the IL-8 50 and IL-8 100 CM groups were significantly increased (P<0.01, n=30). However, HUVEC apoptosis was significantly decreased (P<0.01, n=30). Akt and phospho-Akt (P-Akt) protein contents in lysates of BMSCs treated with IL-8, as well as VEGF and IL-6 protein contents in the supernatant of BMSCs treated with IL-8, were all highly expressed (P<0.01, n=15). These analyses confirmed that IL-8 promoted the expression of 41 core proteins in BMSCs through the PI3K Akt pathway, which could promote the proliferation and migration of vascular endothelial cells. Therefore, in an HG environment, IL-8 activated the Akt signaling pathway, promoted paracrine mechanisms of BMSCs, and improved the proliferation and migration of HUVECs.