白藜芦醇通过Akt/mTOR通路上调自噬改善辐射诱导小肠损伤

目的探讨白藜芦醇是否能够通过调节Akt/mTOR通路改善辐射诱导小肠损伤并研究其机制。方法将24只C57BL/6小鼠随机分为对照组、照射组和照射给药组(每组8只)。照射组和照射给药组小鼠接受9.0 Gy剂量的6MV-X射线全身照射,照射给药组小鼠在照射前3 d至照射后3 d每日腹腔注射白藜芦醇(50 mg·kg~(-1)·d~(-1)),对照组、单纯照射组予等量生理盐水。照射后3.5 d获取小肠组织并制作石蜡块后切片,采用HE染色及免疫组织化学染色行组织学分析;行Western blot试验检测p-Akt/Akt、p-S6RP/S6RP、LC3-Ⅱ、Beclin-1表达。采用ANOVA方差分析进行3组间比较。结果照射给药组小鼠小肠绒毛长度、小肠横断面隐窝数、单个小肠隐窝细胞总数、隐窝细胞Ki67阳性率均高于照射组(均P0.05);照射给药组较照射组小肠组织p-Akt/Akt、p-S6RP/S6RP蛋白表达下降(均P0.001),LC3-Ⅱ、Beclin-1蛋白表达升高(均P0.001)。结论白藜芦醇可能通过抑制Akt/mTOR通路促进受辐射小鼠小肠隐窝细胞自噬从而改善辐射诱导小肠损伤。

Resveratrol ameliorates ionizing irradiation-induced intestinal injury by upregulating autophagy via Akt/mTOR signaling pathways

Objective To investigate whether resveratrol can ameliorate irradiation-induced intestinal injury by upregulating autophagy via Akt/mTOR signaling pathways and its mechanism. Methods Twenty-four C57BL/6 mice were randomly divided into control, irradiation, and treated plus irradiation groups (n=8 for each group). In irradiation and treated plus irradiation groups, the mice received total body irradiation with 6MV X-ray at s single fraction of 9.0 Gy. In treated plus irradiation group, resveratrol (50 mg·kg-1·d-1) was intraperitoneally administered to mice 3 days before irradiation and then 3 days after irradiation. Both control group and irradiation group were given the same amount of normal saline. The small intestine tissues were obtained 3.5 days after irradiation, and then prepared into paraffin section. HE staining and immunohistochemical staining were used for histological analysis and Western blot analysis was used to detect p-Akt/Akt, p-S6RP/S6RP, LC3-II, Beclin- 1 expression. Multiple comparisons between groups were performed by single factor analysis of variance (ANOVA). Result Compared with the irradiation group, the intestinal villous height, the number of total cells per crypt, the number of crypts in a single circumference, and the positive rate of Ki67 expression in crypt cells were improved in the treated and irradiation group (P<0.05). The expression of p-Akt/Akt and p-S6RP/S6RP in the treated and irradiation group were significantly downregulated (all P<0.001), and the expression levels of LC3-II and Beclin-1 protein in the small intestine were upregulated compared with irradiation group (all P<0.001). Conclusion Resveratrol can ameliorate irradiation-induced intestinal injury partly by upregulating autophagy via Akt/mTOR signaling pathways in mice.