硒化低聚氨基多糖对免疫抑制小鼠免疫器官及肠紧密连接蛋白表达的影响

Effect of Low-Molecular-Mass Seleno-aminopolysaccharide on Histomorphology and Expression of Tight Junction Proteins in Immunocompromised Mice

本实验旨在研究硒化低聚氨基多糖(low-molecular-mass seleno-aminopolysaccharide,LSA)对免疫抑制小鼠组织形态、回肠闭合小环蛋白-1(zonula occludens-1,ZO-1)及闭锁蛋白(Occludin)表达的影响。通过腹腔注射环磷酰胺构建免疫抑制模型,测定脏器指数,采用苏木精-伊红染色观察脾脏与空肠组织病理形态,利用反转录实时荧光定量聚合酶链式反应分析ZO-1、Occludin mRNA的表达水平。结果表明:LSA处理显著缓解了环磷酰胺对小鼠免疫器官的抑制作用(P<0.05);与环磷酰胺模型组比较,0.6、0.9 mg/(kg mb·d) LSA组小鼠脾脏结构较清晰,红髓和白髓界限较明显,白髓面积增大,空肠绒毛形态与环磷酰胺模型组相比较为整齐;0.6 mg/(kg mb·d)LSA组的ZO-1、Occludin m RNA表达量显著升高(P<0.05)。综上,LSA具有一定的免疫调节功能及肠道保护作用。

The purpose of this study was to investigate the effect of low-molecular-mass seleno-aminopolysaccharide(LSA) on the histomorphology and the expression of the tight junction proteins zonula occludens-1(ZO-1) and occludin in the ileum of immunocompromised mice. The immunosuppressive mouse model was established by intraperitoneal injection of cyclophosphamide(CPA). The thymus index and spleen index were calculated. Pathological changes in the spleen and jejunum were observed by hematoxylin-eosin staining. The expression of tight junction proteins in the ileum were analyzed by real-time quantitative reverse transcription-polymerase chain reaction(RT-qPCR). The results showed that the spleen and thymus index were significantly increased in the LSA groups(P<0.05) when compared with the CPA group. The spleen structure was clear with an obvious boundary between the red and white pulps and the area of white pulp was increased in the 0.6 and 0.9 mg/(kg mb·d) LSA groups when compared with the CPA group. In addition, the morphology of jejunum villi was more ordered than that of the model group. The mRNA expression of ZO-1 and occludin was significantly increased in the 0.6 mg/(kg mb·d) LSA group(P<0.05). To sum up, LSA had immunomodulatory effects and could be beneficial for intestinal health.