microRNA-31转基因小鼠脊髓损伤模型对胃肠动力障碍的修复作用

目的探讨microRNA-31对脊髓损伤后胃肠动力因素的作用。方法将36只microRNA-31转基因小鼠和36只FVB小鼠分别设为对照组和模型组,用Impactor M-Ⅲ脊髓撞击器建立小鼠脊髓损伤模型。用BBB运动功能评分评估小鼠下肢的恢复情况。HE染色观察脊髓组织的变化。用Real-time PCR法检测生长抑素受体(SSTR2)mRNA的表达,用免疫荧光法检测一氧化氮合酶(iNOS)蛋白和SSTR2蛋白的表达。结果造模后第3天、第7天和第14天,脊髓组织破坏、坏死、空泡形成,胶原纤维明显增加。造模后第14天,FVB模型组与对照组比较,SSTR2 m RNA的表达明显升高(P<0.05),iNOS蛋白和SSTR2蛋白的表达量明显升高;microRNA-31转基因小鼠模型组与对照组比较,SSTR2 mRNA的表达明显升高(P<0.05),iNOS蛋白和SSTR2蛋白的表达量明显升高;microRNA-31转基因小鼠模型组与FVB模型组比较,SSTR2 m RNA的表达明显降低(P<0.05),iNOS蛋白和SSTR2蛋白的表达量明显降低。结论脊髓损伤后胃肠动力障碍的发生可能与SSTR2 m RNA的表达上调、SSTR2蛋白和i NOS蛋白的表达增高有关。高表达的microRNA-31可能与脊髓损伤后胃肠动力障碍的恢复有关。

Tiaoxin Recipe, a Chinese herbal formula, inhibits microRNA-34a expression in the APPswe/PS1ΔE9 mouse model of Alzheimer’s disease

Objective: To investigate the effect and underlying mechanisms of Tiaoxin Recipe(a Chinese herbal formula) treatment on Alzheimer's disease(AD).Methods: Twelve-week-old APPswe/PS1 DE9(APP/PS1) double transgenic mice were used as a model of AD-afflicted mice. One group of mice was treated with Tiaoxin Recipe by gastrogavage for 12 weeks,while two other groups were given intraperitoneal injections of nicotinamide adenine dinucleotide or FK866 for 4 weeks. Morris water maze and thioflavin S staining tests were performed to evaluate cognitive impairment and amyloid plaque deposition, respectively. Serum amyloid-β1-42(Aβ1-42) content was detected using an enzyme-linked immunosorbent assay, and quantitative reverse transcriptionpolymerase chain reaction was performed to examine the expression levels of microRNA-34 a(miR-34 a) in cortex and hippocampus samples of the study mice.Results: Compared with the normal control group, the memory and learning abilities of the APP/PS1 model group were found to be impaired(P < 0.01), as shown by the increased levels of senile plaque deposition in cortex and hippocampus(P < 0.01), miR-34 a expression(P < 0.01) and serum Aβ1-42 content(P < 0.01). Treatment with Tiaoxin Recipe significantly reduced memory impairment(P < 0.01) by reducing amyloid plaque accumulation in cortex and hippocampus(P < 0.01), miR-34 a expression(P < 0.01) and serum Aβ1-42 content(P < 0.01) in APP/PS1 mice.Conclusion: Tiaoxin Recipe is a viable complementary or alternative therapeutic treatment that is capable of delaying the development of early-stage AD by inhibiting the expression of miR-34 a.