Effects of endurance exercise on synaptic plasticity in cerebral cortex of aged rats and related regulatory mechanism / 中国应用生理学杂志

OBJECTIVE@#To understand and analyze the rules of endurance exercise on the cerebral cortex adaptive mechanism in aged rats.@*METHODS@#In this study, 3-month-old (n=20), 13-month-old (n=24) and 23-month-old (n=24) specific-pathogen free (SPF) male Sprague-Dawley Rat (SD) rats were divided into young (Y-SED), middle-aged (M-SED) and old-aged (O-SED) sedentary control group, and the corresponding Y-EX, M-EX and O-EX in the endurance exercise runner group. The 10-weeks of regular moderate-intensity aerobic exercise intervention were carried out in the endurance exercise runner group. The exercise mode is treadmill exercise (slope 0), and the exercise intensity gradually increases from 60%～65% of the maximum oxygen consumption (V·O) to 70%～75%, and the exercise time is 10 weeks. Hematoxylin and eosin (HE) staining was used to detect age-related morphological changes. The expressions of superoxide dismutase(SOD) and brain-derived neurotrophic factor (BDNF) and the expressions of synapsin 1 (SYN1) and Ca/calmodulin- dependent protein kinases IIα (CaMK IIα) / AMP-activated protein kinase α1(AMPKα1) / mammalian target of rapamycin (mTOR) pathway -related genes were detected.@*RESULTS@#The cerebral cortex structure of the rats in each group showed age-related aging changes, the expression of SOD in the cortex showed a gradual decline, the expression of BDNF showed an age-increasing trend, and the expression levels of SYN1 and CaMK IIα were increased with age. The changes in AMPKα1 and SirT2 and IP3R, AKT1 and mTOR mRNA levels were increased slightly in middle-aged rats and decreased in aged rats. Compared with the rats in each sedentary control group, the nucleus of the cerebral cortex was tightly arranged and the number of nuclei observed under the microscope was increased significantly in each exercise group. Exercise promoted the expressions of SOD, BDNF and synaptophysin SYN1 in the cortex of rats, and the expression levels of SOD and BDNF in aged rats were up-regulated significantly (P＜ 0.01). The expression level of SYN1 in rats was up-regulated significantly (P＜0.05) in the young and aged rats. The expression of CaMK IIα in the cortex of middle-aged and aged rats was up-regulated (P＜0.01), while the expression level of CaMK IIα in young rats was down-regulated (P＜0.01). Exercise could up-regulate the expression level of AMPKα1 in the cortex of young rats (P＜ 0.05), but not in middle-aged and old-age rats. Exercise could up-regulate the expression of SirT2 in the cortex of rats in all age groups (P＜0.05). Exercise up-regulated the expression of phosphoinositide 3-kinase (IP3R)/ protein kinase B 1(AKT1) /mTOR in the cortex of rats, among which young IP3R was significantly up-regulated (P＜0.01) in the young group, mTOR was significantly up-regulated in young and middle-aged group (P＜0.01), and mTOR was also significantly up-regulated in the aged group (P＜0.05).@*CONCLUSION@#Endurance exercise up-regulates BDNF expression, regulates CaMKIIα signaling, activates AMPK signaling pathway and IP3R / AKT1 / mTOR signaling pathway, and improves synaptic plasticity in the cortex.

Mental Health Status and Its Influencing Factors in the Floating Population in Chengdu / 中国医学科学院学报

To investigate the mental health status of the floating population in Chengdu and explore its influencing factors. A questionnaire-based survey was conducted on non-Chengdu household workers over 16 years old in four directions(east,south,west,and north)of Chengdu from June 2017 to June 2018 to collect their social demographic characteristics and mental health status information through respondent driven sampling method.The 12-item general health questionnaire(GHQ-12) was used to assess the mental health status of the respondents,and a multivariate logistic regression model was used to analyze the influencing factors of mental health. The average score of GHQ-12 was(1.09±1.61)and the detection rate of mental problems was 7.11%.The main mental problems were anxiety and nervousness.Multivariate unconditional logistic regression analysis showed that over 55 years old(=0.425,95%=0.213-0.847),junior middle school education(=0.541,95%=0.356-0.824),length of residence ≥5 years(5-9 years:=0.603,95%=0.394-0.923;≥10 years:=0.534,95%=0.346-0.823),annual income ≥18 000 yuan(18 000-35 999 yuan:=0.524,95%=0.328-0.836;36 000-59 999 yuan:=0.327,95%=0.190-0.565;≥60 000 yuan: =0.356,95%=0.192-0.662),and a good relationship with employers(=0.519,95%=0.363-0.742)were the protective factors for the mental health.Divorce/widowhood(=2.351,95%=1.341-4.124),plan to return hometown after 5 years(=1.805,95%=1.084-3.006)and not yet consideration of leaving Chengdu(=1.844,95%=1.269-2.681)were the risk factors. The mental health of the floating population in Chengdu is generally good.However,floating individuals with poor marital status and/or poor sense of belonging to Chengdu are at higher risk of mental problems.The local government should formulate and improve the policies and measures related to social welfare and public services for the floating population and try to enhance their urban integration and sense of belonging,thus improving their mental health.

In vitro induction of allo-T lymphocytes proliferation by myeloid dendritic cells in patients with severe aplastic anemia / 中华内科杂志

Objective To investigate the function of myeloid dendritic cells (mDCs) from severe aplastic anemia ( SAA ) patients in stimulating allogeneic T lymphocytes proliferation in vitro and then explore the immunopathogenesis of SAA. Methods Twenty-five SAA patients ( 15 untreated and 10 recovered after immunosuppressive therapy) and 12 normal controls were enrolled in this study. Their mature mDCs were induced from their bone marrow monocytes with recombined human interleukin-4 ( rhIL-4) , recombined human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and recombined human tumor necrosis factor (rhTNF) in vitro. Then mDCs were co-cultured with allogeneic lymphocytes (mixture lymphocyte reaction, MLR) at a ratio of 1: 100 or 1: 50. The growth rate of lymphocyte was measured with methyl thiazolyl tetrazolium ( MTT) colorimetry.The concentrations of interleukin( IL) -12 and inlerferon -y (IFNγ) in MLR supernatant were measured with EL1SA. The correlation between the growth rate and the concentration of IL-12 or IFNγ was analyzed. Results When mDCs and lymphocytes were co-cultured at the ratio of 1: 100, the growth rates of lymphocytes stimulated with mDCs from untreated, recovered SAA patients and controls were (219. 8 ±94. 0)% , (159. 1 ±66. 0)% and (160. 1 ±91. 9)% respectively. The concentrations of IL-12 in MLR supernatant were (8. 2 ± 3. 6) ng/L, (6. 5 ± 2. 8) ng/L and (6. 1 ± 2. 6) ng/L and the concentrations of IFNγ were (21. 8 ± 8. 7) ng/L, (25. 5 ± 9. 1) ng/L and (22. 6 ± 7. 8) ng/L respectively. All of them had no statistical differences among the three groups ( P > 0. 05 ). When mDCs and lymphocytes were co-cultured at the ratio of 1: 50, the growth rate of lymphocytes stimulated with mDCs from untreated patients was (322. 1 ± 171. 1)% , which was higher than that of recovered patients [ (180. 9 ±79. 1)% and controls (192. 3 ±91. 9)% ]. The concentrations of IL-12 in MLR supernatant in the three groups were (12.6 ±4.4) ng/L, (9.4 ±3.3) ng/L and (8.5 ±3.7) ng/L, and the concentrations of IFNγ were (32. 3 + 9. 2 ) ng/L, ( 27. 4 ± 6. 5) ng/L and (24. 4 ± 7. 4 ) ng/L Both of the values in untreated cases were higher than those of the recovered cases or controls (P < 0. 05 ) , but there were no statistical difference between the recovered and control groups ( P >0. 05 ). The concentration of IL-12 in MLR supernatant correlated positively with the growth rate of lymphocyte (r=0. 529,P <0. 01) and so did the concentration of IFNγ (r = 0. 381, P < 0. 05). Conclusion The function of mDCs to stimulate T lymphocytes proliferation in SAA was enhanced; it might play an important role in the immunopathogenesis of SAA.