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Aim To explore the effect of miRNA-143 ( miR-1 4 3 ) on homocysteine ( Hcy ) induced-vascular smooth muscle cells ( VSMCs ) proliferation and the mechanism .Methods VSMCs were cultured and in-cubated with Hcy by using primary cultured method . Then, cells were treated with different concentrations of Hcy and folate .VSMCs proliferation was determined with MTT assay , miR-143 was measured by qRT-PCR, and methylation of miR-143 was determined with meth-ylated PCR.Results After cells were treated with dif-ferent concentrations of Hcy , the proliferation of VSMCs was significantly increased , mRNA expression of miR-143 was decreased and methylation of miR-143 was increased .The proliferation of VSMCs was signifi-cantly decreased when transfected VSMCs with miR-143 precursor , and cell proliferation was increased by using miR-143 inhibitor transfection .Conclusion Hy-pomethylation of miR-143 may inhibit VSMCs prolifera-tion.
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Aim To investigate the role of miR-125 b and its DNA methylation in homocysteine ( Hcy )-in-duced vascular smooth muscle cells( VSMCs) prolifera-tion. Methods VSMCs were stimulated with 0,50, 100, 200, 500 μmol · L-1 Hcy respectively. Then qRT-PCR was used to detect the mRNA levels of miR-125b,and nested-touchdown methylation-specific PCR ( ntMS-PCR) was used to detect the methylation levels of miR-125b. VSMCs were transfected with miR-125b precursor or the inhibitor of miR-125b ,then 3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyl tetrazolium bromide ( MTT ) assay was used to reflect the proliferation of VSMCs. The distribution of CpG islands of miR-125b promoter region was analyzed by bioinformatics meth-ods. VSMCs were stimulated with 100 μmol·L-1 Hcy and transfected with or without DNA methylation inhib-itors 5-nitrogen impurity cytidine ( AZC) , then the ex-pression of miR-125b was detected by qRT-PCR. Re-sults The mRNA levels of miR-125 b were decreased in 100,200,500 μmol·L-1 Hcy group compared with 0 μmol·L-1 Hcy group. The precursor of miR-125b could inhibit the proliferation activity and the inhibitor of miR-125 b could increase the proliferation activity of VSMCs cells. Bioinformatics analysis indicated that MiR-125 b promoter region had a CpG island whose length was 792 bp ( 1881-2672 ) . The miR-125 b pro-moter region methylation levels increased after Hcy in-tervention ( P <0. 01 ) . The expression level of miR-125 b increased after AZC intervention ( P <0. 05 ) . Conclusions ① Hcy promotes vascular smooth mus-cle cell proliferation maybe by down-regulating the ex-pression of miR-125b. ② Hcy down-regulates the ex-pression of miR-125 maybe by up-regulating the methy-lation levels of miR-125b promoter region.
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Aim Observe the effects of IMD_ 1-53 on acute myocardial injury induced by isoproterenol (ISO). Methods Myocardial ischemia injury in rats was induced by subcutaneous injection with ISO(50 mg?kg -1?d -1, 2days ), and the therapeutic effect of IMD_ 1-53 was observed. Cardiac function was measured. Myocardial cAMP content was determined by radioimmunoassay (RIA). The gene expression of calcitonin receptor-like receptor (CL) and receptor-activity-modifying protein (RAMP1), RAMP2 and RAMP3 in ventricular was determined by semi-quantitative RT-PCR analysis. IMD receptors in cardiac sarcolemmal membrane fractions were assayed [ 125I]-IMD binding studies. Results ISO-treated rats showed lower maximal rate of increase and decrease of left-ventricle pressure development (?LVdp/dt_ max) and higher left-ventricle end-diastolic pressure (LVEDP; all P
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Aim To determine the protective effects of IMD on ischemia/reperfusion(I/R) injury and its possible mechanism.Method Isolated rat hearts were perfused by Langendorff mode,and after 45 min global ischemia and 30 min reperfusion ventricular function was measured on a Power Lab,and adequate amount of ventricular tissues and perfusate were collected for biochemical measurement.Results Treatment with IMD during the reperfusion period significantly attenuated the effects of I/R on cardiac function inhibition and tissue injury.Compared with I/R group,IMD induced increase in △LVP,LV(dp/dtmax,HR and CF,whereas induced decrease in LVDP.Reperfusion with IMD exerted decrease in LDH,total protein,Mb and MDA content compared with I/R group,but increased myocardial cAMP content.All these values were similar to the effects of ADM.Furthermore,I/R induced significant increase in Bmax and Kd value.Conclusion IMD exerted beneficial effects on cardiac injury induced by I/R which might be mediated by cAMP pathway.And the cardioprotective effects of IMD were equal to ADM,a potent cytoprotective factor.
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AIM: In this study, we aimed to explore the alteration and pathophysiological significance of the L-arginine (L-Arg)/NOS/NO pathway in the adventitia of rats with sepsis. METHODS: Sepsis was induced by cecal ligation and puncture (CLP). Rat cardiac function was determined. NO generation, NOS activity and L-Arg transport were measured. The iNOS mRNA levels was determined by using RT-PCR. RESULTS: Cecal ligation and puncture induced severe sepsis with severe low glucose, high lacticemia and cardiac function inhibition. The iNOS activity was increased by 2.8-fold compared with controls (P