骨桥蛋白在炎症性肠病患者结肠组织中的表达

Expression of Osteopontin in Colonic Tissue of Patients with Inflammatory Bowel Disease

背景:骨桥蛋白(OPN)是一种分泌型磷酸化糖蛋白,参与细胞信号转导,促进细胞黏附和迁移。近年研究发现炎症性肠病(IBD)患者血浆OPN水平升高,患者结肠黏膜中可检出OPN表达。目的:了解OPN在IBD患者结肠黏膜组织中的表达情况,探讨其在IBD发病机制中的作用。方法:以免疫组化半定量方法检测53例溃疡性结肠炎(UC)、62例克罗恩病(CD)和15例源自结肠腺瘤患者的正常结肠组织标本中OPN的表达。结果:OPN广泛表达于结肠黏膜上皮细胞和固有层渗出细胞。UC组和CD组结肠上皮细胞的OPN平均光密度值显著低于对照组(11.84+0.98和10.04+1.37对12.64+1.45,P<0.05),结肠黏膜固有层渗出细胞的OPN阳性细胞百分率则显著高于对照组(20.31%±4.50%和12.69%+3.06%对3.85%+0.66%,P<0.001)。UC和CD患者的病情严重程度与结肠上皮细胞和固有层渗出细胞中的OPN表达量均无相关性。结论:OPN在IBD患者结肠黏膜上皮和固有层中的表达不一致,结肠上皮细胞中OPN表达下调可能与肠黏膜屏障功能受损有关,而黏膜固有层渗出细胞中OPN表达上调可能与免疫反应有关。

Background： Osteopontin （OPN） is a secreted phosphorylated glycoprotein, which is involved in cell signaling and may promote cell adhesion and migration. Recent studies showed that plasma concentration of OPN was elevated in patients with inflammatory bowel disease （IBD） and it was also expressed in colonic tissue of IBD patients. Aims： To investigate the expression of OPN in colonic tissue of IBD patients and its possible role in the pathogenesis of IBD. Methods： Colonic samples were obtained from patients with ulcerative colitis （UC, n=53）, Crohn＇s disease （CD, n=62） and normal tissue from patients with colonic adenoma （n=15）. OPN expression was determined by semi-quantitative immunohistochemical staining. Results： OPN was found to be expressed by intestinal epithelial cells and lamina propria infiltrating cells of colonic tissue. The average optical density values of OPN in intestinal epithelial cells in UC group and CD group were significantly lower than that in control group （11.84±0.98 and 10.04±1.37 vs. 12.64±1.45, P〈0.05）, while the percentages of lamina propria infiltrating cells expressing OPN in UC group and CD group were significantly higher than that in control group （20.31%± 4.50% and 12.69%±3.06% vs. 3.85%±0.66%, P〈0.001）. No significant correlations were found between OPN expressions in intestinal epithelial cells and lamina propria infiltrating cells and the disease activities of UC and CD. Conclusions： There is a discrepancy of OPN expression between colonic epithelium mueosae and lamina propria in IBD patients. Downregulation of OPN in intestinal epithelial cells might be related to the disintegration of the intestinal mucosal barrier, while the elevated expression of OPN in lamina propria infiltrating cells might be related to the immune response.