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Objective:To investigate the effect of microRNA-27b-3p (miR-27b-3p)/nuclear factor-E2-related factor 2 (Nrf2) on metabolic memory impairment of human retinal pigment epithelial (RPE) cells and to explore its regulatory mechanism.Methods:ARPE-19 cells were divided into normal control group, metabolic memory group, miR-27b-3p control group, miR-27b-3p inhibitor group, and liraglutide group.Cells in normal control group were cultured in 5.5 mmol/L normal glucose medium for 6 days.Cells in metabolic memory group were cultured in 30 mmol/L glucose for 3 days and changed to 5.5 mmol/L for 3 days.Cells in miR-27b-3p inhibitor group were added with puromycin after lentiviral transfection to select the successfully transfected cells, and were cultured in 30 mmol/L glucose for 3 days then 5.5 mmol/L glucose for 3 days.Cells in liraglutide group were cultured in 30 mmol/L glucose with liraglutide for 3 days then 5.5 mmol/L glucose for 3 days.The regulatory relationship between miR-27b-3p and Nrf2 was verified by lentiviral transfection.Expressions of miR-27b-3p, Nrf2, NAD(P)H dehydrogenase[quinone]1 (NQO1), heme oxygenase-1 (HO-1) mRNA and protein levels were analyzed by real-time quantitative PCR.Total and nuclear Nrf2 protein expressions were detected by Western blot.The cell proliferation rates of various groups were determined by cell counting kit-8 (CCK-8).The reactive oxygen species (ROS) level was detected by the DHE kit.Results:The miR-27b-3p mRNA relative expression of normal control group, metabolic memory group, miR-27b-3p control group, miR-27b-3p inhibitor group was 1.000±0.000, 1.881±0.034, 1.683±0.088 and 0.111±0.008, respectively, with a statistically significant difference ( F=850.815, P<0.001).The miR-27b-3p mRNA relative expression level was lower in normal control group than in metabolic memory group, lower in miR-27b-3p inhibitor group than in normal control group, and the differences were statistically significant (both at P<0.01).The expression levels of Nrf2 mRNA, total protein, and nuclear protein were decreased in metabolic memory group in comparison with normal control group and were significantly increased in miR-27b-3p inhibitor group in comparison with miR-27b-3p control group, showing statistically significant differences (all at P<0.01).The NQO1 and HO-1 mRNA expressions were decreased in metabolic memory group in comparison with normal control group, and were significantly higher in miR-27b-3p inhibitor group compared with miR-27b-3p control group, showing statistically significant differences (all at P<0.01).The fluorescence intensity of Nrf2, NQO1, and HO-1 was lower in metabolic memory group than in normal control group, and was higher in miR-27b-3p inhibitor group than in miR-27b-3p control group, showing statistically significant differences (all at P<0.01).Compared with metabolic memory group, the relative expression of miR-27b-3p mRNA declined in liraglutide group, with a statistically significant difference ( P<0.05).The relative expression levels of Nrf2 mRNA, NQO1 mRNA, HO-1 mRNA, total and nuclear Nrf2 protein of liraglutide group were enhanced in comparison with metabolic memory group, with statistically significant differences (all at P<0.05).The fluorescence intensity of Nrf2, NQO1, and HO-1 was enhanced in liraglutide group in comparison with metabolic memory group, and the differences were statistically significant (all at P<0.05).Compared with normal control group and liraglutide group, the cell proliferation viability was decreased in metabolic memory group, and the differences were statistically significant (both at P<0.01).The relative content of ROS was higher in metabolic memory group than in normal control group and liraglutide group, and the difference was significant (all at P<0.01). Conclusions:Liraglutide reverses the inhibition of metabolic memory on Nrf2, NQO1, and HO-1 by downregulating miR-27b-3p.
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Objective:To investigate the correlation between peripheral blood microRNA (miR)-27b expression and left ventricular hypertrophy (LVH) in patients with hypertensive.Methods:The clinical data of 120 patients with hypertension from February 2019 to February 2021 in Zhuzhou Hospital Affiliated to Xiangya School of Medicine, Central South University were retrospectively analyzed. Among them, LVH occurred in 70 cases (LVH group), none in 50 cases (NLVH group). The ventricular septal thickness (VST), left ventricular posterior diastolic wall thickness (LVPWTd) and left ventricular end diastolic diameter (LVEDD) were measured by echocardiography, the left ventricular mass (LVM) and left ventricular mass index (LVMI) were calculated. The peripheral blood expression level of miR-27b was detected by real-time quantitative polymerase chain reaction. Correlation was analyzed by Pearson correlation analysis. Receiver operating characteristic (ROC) curve was drawn to evaluate the efficacy of peripheral blood miR-27b in diagnosing LVH in patients with hypertensive.Results:The peripheral blood expression level of miR-27b in LVH group was significantly higher than that in NLVH group (6.37 ± 0.23 vs. 3.42 ± 0.18), and there was statistical difference ( t = 9.58, P<0.01). Pearson correlation analysis result showed that the peripheral blood expression of miR-27b was positively correlated with LVMI, VST, LVEDD and LVPWTd in hypertensive LVH patients ( r = 0.71, 0.63, 0.75 and 0.68; P<0.01). After eliminating risk factors (duration of hypertension, systolic blood pressure, diastolic blood pressure, different medications, uric acid), multiple linear regression analysis result showed that the peripheral blood expression of miR-27b was positively correlated with LVMI, VST, LVEDD and LVPWTd in hypertensive LVH patients ( β = 0.07, 0.63, 0.42 and 0.48; P<0.01). ROC curve analysis result showed that the area under the curve of peripheral blood expression of miR-27b in predicted LVH in patients with hypertension was 0.905 (95% CI 0.854 to 0.957), the optimal cut-off value was 4.45, the sensitivity was 84.0%, and the specificity was 82.9%. Conclusions:The high peripheral blood expression of miR-27b in hypertension LVH patients is positively correlated with LVMI and other echocardiographic parameters, which has a good predictive value of LVH in patients with hypertension.
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SUMMARY: Cerebral ischemia has not only a high mortality rate, which is the second leading cause of death worldwide, but is also responsible for severe disabilities in working age individuals, generating enormous public expending for treatment and rehabilitation of the affected individuals. The role of microRNAs in the pathophysiology of cerebral ischemia has been highlighted in current investigations. In addition, recent studies have also highlighted physical exercise as a possible protective factor both in the prevention and in the effects of cerebral ischemia, placing it as an important study resource. Thus, we investigated the role of physical exercise in experimental cerebral ischemia associated with the expression of microRNA-27b. 16 animals were used, divided into four experimental groups: Control, Physical Exercise, Cerebral Ischemia and Cerebral Ischemia associated with Physical Exercise. The real-time PCR methodology was used to analyze the expression of microRNA-27b. Although there were no statistically significant differences in the expression of microRNA-27b between the groups studied, the increased expression of microRNA-27b in the Physical Exercise group indicates its neuroprotective role in the pathophysiology of cerebral ischemia.
RESUMEN: La isquemia cerebral no solo tiene una alta tasa de mortalidad y es la segunda causa principal de muerte en todo el mundo, sino también es la causa de enfermedades invalidantes en personas en edad laboral, lo que genera un gasto público enorme para el tratamiento y la rehabilitación de las personas afectadas. El papel de los microARN en la fisiopatología de la isquemia cerebral se ha destacado en las investigaciones actuales. Además, estudios recientes también han destacado el ejercicio físico como un posible factor protector tanto en la prevención como en los efectos de la isquemia cerebral, situándolo como un importante recurso de estudio. Por lo tanto, investigamos el papel del ejercicio físico en la isquemia cerebral experimental asociada con la expresión del microARN-27b. Se utilizaron 16 animales, divididos en cuatro grupos experimentales: Control, Ejercicio Físico, Isquemia Cerebral e Isquemia Cerebral asociada al Ejercicio Físico. Se utili- zó la metodología de PCR en tiempo real para analizar la expresión de microARN-27b. Aunque no se observaron diferencias estadísticamente significativas en la expresión de microARN-27b entre los grupos estudiados, la mayor expresión de microARN-27b en el grupo de Ejercicio Físico indica su papel neuroprotector en la fisiopatología de la isquemia cerebral.