ABSTRACT
Objective To investigate the effect of microRNA-9-5p (miR-9-5p) regulating transient receptor potential melastatin 7 (TRPM7) on myocardial ischemia-reperfusion (MIR) in rats. Methods Thirty-two SD rats were divided into sham operation group, model group, miR-9-5p overexpression group and empty vector control group. The MIR model was established by ligation of left coronary artery. The sham operation group was not ligated. miR-9-5p agomir and agomir NC were injected into tail vein 24 hours before model establishment in miR-9-5p overexpression group and empty vector control group. The myocardial injury was observed by HE staining. The expression of miR-9-5p was detected by Real-time PCR. The serum levels of interleukin(IL)-6, tumor necrosis factor alpha(TNF-α), IL-1β, creatine kinase isoenzyme MB (CK-MB), cardiac troponin Ⅰ (cTnI), lactate dehydrogenase (LDH) and the contents of malondialdehyde (MDA) and superoxide dismutase (SOD) in myocardium were measured were measured by ELISA. Cardiomyocyte apoptosis was detected by TUNEL. Double luciferase assay verified the relationship between miR-9-5p and TRPM7. The protein expressions of TRPM7, Bcl-2, Bcl-2 associated X (Bax), phosphorylated nuclear factor kappa-B 65 (p-NF-κB p65) and toll like receptor 4 (TLR4) were detected by Western blotting. Results The expression of miR-9-5p was low in myocardial tissue of rats (P<0.05). Overexpression of miR-9-5p could reduce the expression levels of CK-MB, cTnI and LDH, and improve the degree of myocardial injury. Compared with the model group, the apoptosis rate, Bax protein expression, MDA, IL-6, TNF-α and IL-1β contents in myocardial cells of miR-9-5p overexpression group decreased, while Bcl-2 protein expression and SOD content increased (P<0.05). The result of dual luciferase assay showed that TRPM7 was the target gene of miR-9-5p, and the protein expressions of TRPM7, p-NF-κB p65 and TLR4 in miR-9-5p overexpression group were lower than those in model group (P<0.05). Conclusion MiR-9-5p can inhibit myocardial cell apoptosis, oxidative stress and inflammation induced by myocardial ischemia-reperfusion, and inhibit TLR4/NF-κB pathway by regulating TRPM7.
ABSTRACT
OBJECTIVE@#To explore the mechanism of acupuncture plus medication on treatment of Alzheimer's disease (AD).@*METHODS@#Sixty adult SD rats were randomly divided into a normal group, a sham operation group, a model group, an electroacupuncture (EA) group, a gastrodin group and an EA+gastrodin group, 10 rats in each one. The rat model of AD was established by intraperitoneal injection of D-galactose and bilateral hippocampal injection of Aβ1-40. Two weeks after modeling, the rats in the EA group and EA+gastrodin group were treated with EA at "Baihui" (GV 20) "Dazhui" (GV 14) and bilateral "Zusanli" (ST 36), 30 min per treatment, once a day for consecutive 4 weeks. The rats in the gastrodin group and EA+gastrodin group were treated with intraperitoneal injection of gastrodin, once a day for consecutive 4 weeks. The rats in the normal group, model group and sham operation group were not treated. The morphology of hippocampal neurons was observed by using HE staining. The expression of Bcl-2 and Bax in the hippocampal CA1 area was detected by using immunohistochemical method. The expression of Bcl-2 and Bax protein in hippocampus was detected by using Western blot.@*RESULTS@#The HE staining results showed the arrangement of neurons in the hippocampal CA1 area was regular in the normal group and the sham operation group, and the cytoplasm and nucleus were clearly visible. The neurons in the model group were severely damaged; the cell arrangement was not close, and the cell morphology was incomplete. Compared with the model group, the cell morphology of each intervention group was significantly improved. The immunohistochemistry results showed that, compared with the normal group and the sham operation group, the expression of Bcl-2 in the hippocampal CA1 region in the model group was decreased (<0.05), but the expression of Bax was enhanced (<0.05); compared with the model group, the expression of Bcl-2 was increased (all <0.05) and the expression of Bax was decreased (all <0.05) in all intervention group; compared with the EA group or the gastrodin group, the expression of Bcl-2 was enhanced (<0.05) and the expression of Bax was decreased (<0.05) in the EA+gastrodin group. The result of Western blot method was consistent with that of immunohistochemistry method.@*CONCLUSION@#EA and gastrodin could significantly inhibit the expression of Bax and up-regulate the expression of Bcl-2, and the combination of EA and gastrodin has the most significant effect. This indicates that EA combined with gastrodin has synergistic effect on inhibiting the apoptosis of neurons in hippocampus in AD rats, which may be one of the mechanisms of EA plus medication on AD lesions.