MicroRNA-135b-5p Downregulation Causes Antidepressant Effects by Regulating SIRT1 Expression.

Depression is a serious and potentially life-threatening mental illness. Recently, the role of sirtuin 1 (SIRT1) in chronic unpredictable mild stress (CUMS) management has been examined. The present study explored and clarified whether microRNA (miR)-135b-5p could play a role in depression by regulating the expression of SIRT1. SIRT1 was identified as the target gene of miR-135b-5p using TargetScan and the dual luciferase reporter assay. In addition, the expression levels of SIRT1 were significantly reduced in mouse peripheral blood and hippocampal tissue samples, while the expression of miR-135b-5p exhibited the opposite effects. Subsequently, the effects of miR-135b-5p inhibition were investigated in mice with depression. The results indicated that the miR-135b-5p inhibitor significantly increased the weight loss induced by CUMS compared with the model group, while reducing the expression levels of miR-135b-5p and further alleviating the depression-like behavior induced by CUMS. Concomitantly, the results indicated that the miR-135b-5p inhibitor inhibited CUMS-induced hippocampal cell apoptosis and significantly reduced the expression levels of cleaved caspase-3 and the ratio of cleaved caspase-3/caspase-3. Moreover, the miR-135b-5p inhibitor significantly reduced the CUMS-induced increase of the inflammatory factors IL-1ß, IL-6 and TNF-α in the hippocampal mouse samples, while significantly increasing the expression levels of SIRT1. Finally, the results demonstrated that all the effects of the miR-135b-5p inhibitor on CUMS-induced mice were significantly reversed by SIRT1 silencing. In conclusion, the present study indicated that the miR-135b-5p/SIRT1 pathway was a key mediator of antidepressant effects induced in depressed mice. Therefore, it could be considered a potential therapeutic target for the treatment of CUMS-induced depression.

[A prevalence study on mild cognitive impairment among elderly populations in Zhejiang province].

OBJECTIVE: To understand the prevalence of older people with mild cognitive impairment (MCI) in Zhejiang province and to provide the basis for elderly early detection and diagnosis of Alzheimer's disease (AD). METHODS: 1211 more than 60-year-old elderly populations were selected in Zhejiang province, and were given screening questionnaire by general information, the montreal cognitive assessment (MoCA) and mini-mental state examination (MMSE). RESULTS: MCI prevalence of elderly populations in Zhejiang was 20.7% and the AD prevalence was 4.5%. The patient's gender, age, education level, nature of work, sleep status, marital status, whether or not participating in physical exercise, having smoking and drinking habits, whether combined with hypertension and diabetes for MCI prevalence of the elderly were statistically significant (P < 0.05). CONCLUSION: We should pay attention to take appropriate measures in preventing the cognitive decline for populations as elderly, especially for women, senior, no spouse, engaged in manual labor, low education level, poor quality of sleep and no physical exercise, with smoking and drinking, combined with hypertension and diabetes.