DHI increases the proliferation and migration of Schwann cells through PI3K/AKT pathway and the expression of CXCL12 and GDNF to promote facial nerve function repair

Abstract

BackgroundDanhong injection (DHI) is a commonly used drug in the treatment of cardiovascular and cerebrovascular diseases, and its neuroprotective research has been fully confirmed. Schwann cells, as myelin forming cells of peripheral nerve, play an important role in the process of injury and repair. The purpose of this study was to explore the effect of DHI on Schwann cells and its role in facial nerve injury.MethodsRSC 96 Schwann cells were treated with different concentrations (0 –2%) of DHI for different time intervals (12 and 36 h). Effect of DHI on cell viability and migration were determined by CCK8 and Transwell assays. The levels of PI3K-Akt signaling related proteins were measured by western blotting analysis, and the effects of DHI on GDNF and CXCL12 using Western Blot, RT-qPCR, and ELISA assays at the cellular and animal levels, respectively. Then LY294002, an inhibitor of PI3K, was used to study the effect of DHI on cell migration and secretion of CXCL12 and GDNF in RSC96 cells by Transwell, Western Blot, RT-qPCR, and ELISA assays. Finally, facial nerve scoring and S-100 immunofluorescence staining were used to study the therapeutic effects of DHI on facial nerve injury.ResultsOur study found that DHI can promote the proliferation and migration of RSC96 cells, and this effect is related to the activation of PI3K/AKT pathway. LY294002 inhibits the proliferation and migration of RSC96 cells. Besides, DHI can also promote the expression of CXCL12 and GDNF at gene and protein levels, and CXCL12 is, while GDNF is not, PI3K/AKT pathway-dependent. Animal experiments confirmed that DHI could promote CXCL12 and GDNF expression, and promote facial nerve function recovery and myelin regeneration. Conclusion Our in vitro and in vivo experiments demonstrated that DHI could promote proliferation and migration of Schwann cells through the PI3K/AKT pathway, and increase the expression of CXCL12 and GDNF to promote facial nerve function repair.