[Human dental pulp stem cells conditioned medium protects genioglossus myoblast from cobalt chloride-induced hypoxia injury through AMPK/PGC-1α pathway].

PURPOSE To study the effect of hypoxia induced by cobalt chloride (CoCl2) on viability and oxidative stress of genioglossus myoblast, and to explore the mechanism of the protective effect of conditioned medium (CM) on human dental pulp stem cells (hDPSCs). METHODS The hDPSCs were isolated and cultured, and the conditioned medium was prepared by ultrafiltration concentration. Mouse genioglossus myoblasts were isolated and divided into control group, CM group, CoCl2 group and CoCl2+CM group. The cell viability of genioglossus myoblasts was detected by CCK-8. The intracellular and mitochondrial ROS levels were evaluated by DCFH-DA and MitoSOX, respectively. The expression level of mitochondria-related genes in NRF-1 and NRF-2 were analyzed by real-time PCR. The expression of PGC-1α, p-AMPK and total AMPK protein was detected by Western blot. Statistical analysis was performed using SPSS 22.0 software package. RESULTS The proliferation of genioglossus myoblasts was significantly decreased after 200 μmol/L CoCl2 treatment for 24 h (P<0.05), and the levels of reactive oxygen species (ROS) were significantly increased in intracellular and mitochondria (P<0.05). Compared with CoCl2 group, the proliferation ability of hDPSCs-CM was dramatically raised (P<0.05), and the intracellular and mitochondrial ROS content was remarkably decreased(P<0.05). hDPSCs-CM up-regulated the protein expression levels of pAMPK and PGC-1α in genioglossus myoblasts and mitochondrial downstream effectors of PGC-1α, including mRNA expression levels of NRF-1, NRF-2 (P<0.05). CONCLUSIONS Human dental pulp stem cells conditioned medium can alleviate hypoxia injury induced by CoCl2 in genioglossus myoblasts, and its mechanism may be related to AMPK/PGC-1α signaling pathway.