Effects of Banxia Xiexin Decoction on apoptosis of interstitial cells of Cajal via regulation of MiR-451-5p: An in vivo and in vitro study

Banxia Xiexin Decoction (BXD) is a traditional Chinese medical formula applied to gastrointestinal (GI) motility disorders. Previous studies showed that miR-451-5p was down-regulated in rats with GI motility disorders induced by gastric electrical dysrhythmia. Interstitial cells of Cajal (ICCs) are pacemakers for GI motility, while loss of ICCs is responsible for GI motility disturbance. Thus, the underlying interaction mechanisms for BXD regulating ICCs apoptosis via miR-451-5p remain to be explored.In this work, the main objectives were to examine the efficacy of BXD on ICCs via miR-451-5p both in GI motility disorders rats model and in vitro, as well as the potential contributions of SCF/c-kit signaling.Rats with gastric electrical dysrhythmia were established in male SD rats by using a single-day diet and a double fasting method (drinking diluted hydrochloric acid water during the period) for 4 weeks. The gastric slow wave (GSW) recording, RT-qPCR, and western blot were performed to examine the effects of BXD on ICCs apoptosis in rats with GED and miR-451-5p expression. In vitro assays included CCK-8, flow cytometry analysis, RT-qPCR, and western blot were applied to investigate the potential molecular mechanism of BXD on ICCs apoptosis via miR-451-5p.BXD promoted gastric motility, reduced ICCs apoptosis, and elevated miR-451-5p in GED rats. In addition, miR-451-5p was significantly up-regulated in ICCs after BXD treatment compared with that in ICCs with miR-451-5p inhibitor transfection. Meanwhile, high miR-451-5p expression with either BXD treatment or miRNA mimics enhanced ICCs proliferation and inhibit apoptosis. Moreover, overexpression of miR-451-5p can reverse G0/G1 arrest in ICCs by BXD treatment. Further, SCF and c-kit protein levels were detected to demonstrate that modulation of miR-451-5p by BXD treatment was involved in this signaling.Through this study, we demonstrated that BXD could promote ICCs proliferation and inhibit apoptosis via miR-451-5p and may involve the modulations of SCF/c-kit signaling, thus suggesting a new therapy basis for GI motility dysfunction from the perspective of modulation of ICCs apoptosis by targeting miR-451-5p.