背景:低强度脉冲超声(LIPUS)联合穴位可促进糖尿病大鼠胃运动。胃平滑肌细胞(GSMC)表型的转变与糖尿病引起的胃功能障碍有关,但机制尚不清楚。本研究旨在探讨LIPUS刺激对糖尿病胃轻瘫大鼠的作用机制。
方法:在本研究中,SD-Dawley雄性大鼠分为三组:对照组(CON),糖尿病性胃轻瘫组(DGP),和LIPUS治疗组(LIPUS)。在ST36双侧进行LIPUS照射,每天20分钟,持续4周。通过超声检查测量胃排空率。通过肌肉条实验评估GSMC的收缩能力。相关蛋白或mRNA的表达,包括α-SMA,SM22α,MHC,RhoA,Rock2,p-MYPT1,MYPT1,p-MLC,MLC,MALAT1,miR-449a,DLL1通过蛋白质印迹等不同方法检测,RT-qPCR,免疫组织化学,免疫荧光染色,视情况而定。
结果:(a)ST36LIPUS刺激可改善糖尿病大鼠胃运动功能障碍。(b)LIPUS增加了RhoA,Rock2、p-MYPT1和p-MLC表达水平。(c)MALAT1和DLL1含量降低,但miR-449a水平在LIPUS组中升高。
结论:LIPUS可能通过RhoA/Rock和MALAT1/miR-449a/DLL1通路影响胃平滑肌收缩标志物的表达,从而改善DGP。
BACKGROUND: Low-intensity pulsed ultrasound (LIPUS) combined with acupoint can promote gastric motility of diabetic rats. The switch of gastric smooth muscle cell (GSMCs) phenotype was related to the diabetes-induced gastric dysfunction, but the mechanism is not clearly elucidated. This study was aimed at exploring the underlying mechanism of LIPUS stimulation application in diabetic gastroparesis rats.
METHODS: In this study, Sprague-Dawley male rats were divided into three groups: control group (CON), diabetic gastroparesis group (DGP), and LIPUS-treated group (LIPUS). LIPUS irradiation was performed bilaterally at ST36 for 20 min per day for 4 weeks. The gastric emptying rate was measured by ultrasound examination. Contraction ability of GSMCs was assessed by muscle strip experiment. The expression of related proteins or mRNAs including α-SMA, SM22α, MHC, RhoA, Rock2, p-MYPT1, MYPT1, p-MLC, MLC, MALAT1, miR-449a, and DLL1 was detected by different methods such as western blotting, RT-qPCR, immunohistochemistry, and immunofluorescence staining, as appropriate.
RESULTS: (a) LIPUS stimulation at ST36 could improve the gastric motility dysfunction of diabetic rats. (b) LIPUS increased RhoA, Rock2, p-MYPT1, and p-MLC expression level. (c) MALAT1 and DLL1 contents were decreased, but the level of miR-449a was increased in the LIPUS group.
CONCLUSIONS: LIPUS may affect the contractile marker expression of gastric smooth muscle through the RhoA/Rock and MALAT1/miR-449a/DLL1 pathway to ameliorate DGP.