Effect of Substance P on Bone Marrow Mesenchymal Stem Cells Differentiation in High Glucose Environment

Bone marrow mesenchymal stem cells (BMSCs) can be used to treat bone defects. The neuropeptide substance P (SP) plays an important role in a variety of life activities. However, the effect of SP on BMSCs differentiation in high glucose environment remains unclear. Rat BMSCs were isolated and divided into control group; high glucose group; and SP group. The secretion of SP was detected by ELISA; cell proliferation was detected by MTT assay; apoptosis activity was detected by Caspase3 activity kit. Real time PCR was performed to measure Bax and Bcl-2 expression. Alizarin red staining was to detect calcified nodule formation. Western blot was done to measure AMPK/mTOR signaling protein expression. In high glucose environment, SP secretion was significantly decreased, along with increased cell proliferation, Caspase3 activity and Bax expression. Meanwhile, Bcl-2 expression, ALP activity and calcified nodules formation was significantly decreased with reduced AMPK phosphorylation and increased mTOR expression (P < 0.05). SP addition in high glucose environment significantly promoted SP secretion and cell proliferation, decreased Caspase3 activity and Bax expression, increased Bcl-2 expression, ALP activity and calcification nodules formation with increased AMPK phosphorylation and decreased mTOR expression (P < 0.05). In high glucose environment, SP secretion is decreased in BMSCs. Up-regulation of SP in BMSCs cells in high glucose environment inhibit the apoptosis of BMSCs and promote cell proliferation and osteogenesis by regulating AMPK/mTOR signaling pathway.