基于TFF/PAR介导的ERK信号转导途径研究艾灸促进胃黏膜损伤修复的作用机制

Gastric mucosal injury is a major pathophysiological link of gastric ulcer, and acupuncture and moxibustion have a better curative effect on it. A large number of clinical practice have confirmed that moxibustion therapy is of approving prevention and cure for diseases of gastric mucosal injury. It not only can improve clinical symptoms, but also has the anti-damage effects, and can promote the repair and healing of gastric mucosal injury. But the mechanism of moxibustion can promote the repair of gastric mucosa following injury needs further elucidation. According to the latest research, protease activated receptor (PAR) could be used as the cell-membrane receptor of trefoil factor (TFF) during the repair of gastric mucosa following injury. Based on our new finding, the project takes a further research surrounds activating TFF and the signal path of ERK on the protective effect of moxibustion in cell proliferation. In order to elucidate the mechanism of moxibustion promoting repair of gastric mucosal injury based on the signal transduction pathway of ERK mediated by TFF/PAR. We put forward a new hypothesis: moxibustion promoting TFF act on PAR →releasing TGF-α→phosphorylating EGFR →activating ERK1/2→transcription factor expression→ cell proliferation up-regulation→ repair of gastric mucosa.

胃黏膜损伤是导致胃溃疡的主要病理生理学环节，针灸对其有着较好的疗效，大量的临床实践证实，运用艾灸防治胃黏膜损伤相关的疾病，不仅可以改善临床症状，还具有抗损伤作用，可以促进溃疡修复和愈合。但是艾灸促进胃黏膜损伤修复的机制仍需要进一步阐明。本项目基于胃黏膜损伤修复机制最新研究进展――蛋白酶激活受体（PAR）可作为胃黏膜损伤修复三叶因子（TFF）的细胞膜受体，结合课题组新近研究结果，围绕启动黏膜修复动力原因子、激活ERK信号转导途径，进一步探讨艾灸启动胃黏膜细胞增殖、黏膜重建保护效应，从TFF/PAR介导的ERK信号转导途径初步揭示艾灸促进胃黏膜损伤修复的作用机制，提出了新的研究假说：艾灸促进动力原TFF作用于细胞膜受体PAR→引起TGF-α释放→EGFR激活和磷酸化→细胞外信号调节激酶ERK1/2的活化→核内转录因子表达→细胞增殖加强→胃黏膜损伤修复。

胃黏膜损伤是导致胃溃疡的主要病理生理学环节，针灸对其有着较好的疗效，大量的临床实践证实，运用艾灸防治胃黏膜损伤相关的疾病，不仅可以改善临床症状，还具有抗损伤作用，可以促进溃疡修复和愈合。本项目基于胃黏膜损伤修复机制最新研究进展――蛋白酶激活受体（PAR）可作为胃黏膜损伤修复三叶因子（TFF）的细胞膜受体，结合课题组新近研究结果，围绕启动黏膜修复动力原因子、激活ERK 信号转导途径，进一步探讨艾灸启动胃黏膜细胞增殖、黏膜重建保护效应。采用水浸束缚应激法、无水乙醇灌胃等方法制备大鼠胃黏膜损伤模型，以艾灸预处理足三里、中脘、脾俞、胃俞等穴位为被试因素，按Guth标准记录大鼠胃黏膜损伤指数，光镜下观察胃黏膜组织形态学变化；采用放免法检测血清中EGF、TGF-α的含量；酶免法检测胃黏膜组织中EGF、TGF-α、TFF1、MT、HSP70、PCNA等物质的含量；Western blot和免疫组化法检测EGFR、p-ERK1/2、AP-1蛋白表达，RT-PCR法检测胃黏膜、下丘脑、下颌下腺中ERK 1/2 mRNA的表达。研究结果结论：（1）艾灸预处理可明显改善胃黏膜损伤大鼠胃黏膜组织形态学，降低胃黏膜损伤指数，具有相对穴位特异性。（2）艾灸预处理可上调胃黏膜损伤大鼠血清、胃黏膜EGF、TGF-α的含量，促进细胞增殖，组织修复。（3）艾灸预处理通过上调胃黏膜损伤大鼠胃黏膜HSP70、MT表达，激发了机体内源性保护机制，提高机体免疫力，为艾灸预保护作用的发挥奠定了一定的物质基础。（4）艾灸预处理可上调胃黏膜损伤大鼠胃黏膜细胞增殖相关物质PAR、TFF、PCNA的表达，促进胃黏膜细胞增殖修复。（5）艾灸预处理通过对胃黏膜损伤大鼠胃黏膜ERK信号转导途径中关键因子EGFR、p-ERK1/2、AP-1的上调，实现促进胃黏膜细胞增殖的修复作用，PAR/TFF介导的ERK信号转导途径是艾灸促进胃黏膜损伤修复的作用机制之一。初步揭示艾灸促进胃黏膜损伤修复的作用机制：艾灸促进动力原TFF 作用于细胞膜受体PAR→引起TGF-α释放→EGFR 激活和磷酸化→细胞外信号调节激酶ERK1/2 的活化→核内转录因子表达→细胞增殖加强→胃黏膜损伤修复。