LRIG2在小鼠胃肠道中的分布特点及其意义

Characteristics and significance of distribution of LRIG2 in gastrointestinal tract of mice

目的观察富含亮氨酸重复序列免疫球蛋白样蛋白2(LRIG2)在小鼠胃肠道中分布特点,并探讨LRIG2在胃肠动力调控以及胃肠道肿瘤发生中所起的作用。方法采用Western blotting检测LRIG2蛋白在成年小鼠胃、小肠、结肠中的表达水平,免疫荧光法检测LRIG2在胃肠道黏膜层、黏膜下层、肌层的分布特点,以及LRIG2在Cajal间质细(interstitial cells of Cajal)、PDGFRɑ阳性细胞或肠内胶质细胞的表达情况。结果 LRIG2蛋白在胃、小肠、结肠均有表达,而且表达水平三者差异有统计学意义(P<0.05);其中结肠最高,小肠次之,胃最低。肠道切片免疫荧光染色结果提示,LRIG2阳性细胞主要分布于胃、小肠、结肠肌间神经丛;LRIG2阳性细胞在小肠黏膜下层也有分布。肠道全层铺片免疫荧光染色结果提示,LRIG2阳性细胞广泛分布于肌间神经丛中,细胞呈卵圆形,并团簇状紧密排列。肠内胶质细胞并不表达LRIG2,但是包绕于LRIG2阳性细胞周围。LRIG2在Cajal间质细胞以及PDGFRα阳性细胞上也均不表达,但是LRIG2阳性细胞和二者紧密相邻。结论LRIG2在胃肠道中分布广泛,并且和胃肠动力以及胃肠道细胞增殖的调控密切相关。LRIG2可能是研究胃肠动力紊乱性疾病以及肠道肿瘤的发病机制的一个新靶点。

Objective To investigate the expression of leucine-rich repeat immunoglobulin-like protein 2（LRIG2） in the gastrointestinal tract of mice and explore the role of LRIG2 in gastrointestinal motility regulation and gastrointestinal tumorigenesis.Methods Western blotting was used to detect the expression level of LRIG2 protein in the stomach, small intestine and colon of adult mice. Immunofluorescence was used to detect the distribution of LRIG2 in the gastrointestinal mucosa, submucosa and muscularis, and the expression of LRIG2 in interstitial cells of Cajal, PDGFRɑ positive cells or enteric glia.Results LRIG2 protein was expressed in the stomach, small intestine, and colon, and the expression level was statistically different（ P 〈0.05）,the highest in the colon, followed by the small intestine and the stomach. Immunofluorescence staining of frozen section of gastrointestinal tract showed that LRIG2-positive cells were mainly distributed in the gastric, intestinal and colonic myenteric plexus, and LRIG2 positive cells were also distributed in the small intestinal submucosa. The results of immunofluorescence staining of gastrointestinal tract whole-mount preparations showed that LRIG2 positive cells were widely distributed in the myenteric plexus and the cells were ovoid and clustered closely. LRIG2 was not expressed in enteric glia, but LRIG2 positive cells were surrounded by enteric glia. Moreover, LRIG2 was not expressed in interstitial cells of Cajal and PDGFRα positive cells, but LRIG2 positive cells were closely adjacent to each other.Conclusion The results above suggest that LRIG2 is widely distributed in the gastrointestinal tract and closely related to the regulation of gastrointestinal motility and cell proliferation. Therefore, LRIG2 can be used as a new target for studying the pathogenesis of gastrointestinal motility disorders and gastrointestinal neoplasms.