| Objective: To study the effects of SIRT1 on Smad3 acetylation and myocardial fibrosis through TGF-β1/Smad3 pathway by using resvertrol in DCM.Methods:(Part 1) To establish rat model of EAM/DCM :30 male Lewis rats were randomly divided into two groups:(1) experimental group(15): the porcine cardiac myosin was emulsified with an equal volume of FA, then injected into both footpads of rats in 0d and 7da;(2) normal control group(15): rats were injected with PBS and FA in the same way. All divided into different subgroups in accordance with 21 days, 56 days and 90 days after the first immunization.After transthoracic echocardiograohy, to measure the heart and body weight after sacrificed. The myocardial tissues were stained with HE, MASSON, SR to observe the change of the histopathological characteristics. Real-time fluorescence quantitative PCR detection were used to qualitative analysis the expression of ColⅠ,Ⅲm RNA.(Part 2) RSV intervention:20 male Lewis rats were randomly divided into four groups:(1) normal control group,(2) DCM group,(3) RSV low-dose group(10mg/kg/d),(4) RSV high-dose group(50 mg/kg/d),each group consisted 5 rats. Established the model of DCM as above-mentioned and RSV gavages from 28 days after the first immunization.Transthoracic echocardiography, histopathological characteristics, Real-time fluorescence quantitative PCR, Co-Immunoprecipitation and western-blot were performed in four groups of rats on the 90 th day after the first immunization.Results:(Part 1) Compared with the same period of normal group1.Echocardiography:In experimental group, LVEDD and LVESD increased(P<0.01)in 21,56 and 90 days after the first immunization; LVEF and FS decreased significantly(P<0.01), systolic function decreased significantly in 56 and 90 days after the first immunization. 2. MASSON and SR staining: 56 days after the first immunization, collagen fiberssignificantly increased. 90 days after the first immunization, collagen fibers diffusely increased and showed a large grid shape change. 3.In experimental group, the expression of ColⅠenhanced(P<0.05)and ColⅢ had no statistical significance(P>0.05)in 21 days after the first immunization. The expression of ColⅠ,Ⅲ were significantly enhanced in 56 days and 90 days after the first immunization(P<0.01).(Part 2) RSV intervention:1.Echocardiography: Compared with DCM group, LVEDD and LVESD significantly decreased(P<0.01), LVEF and FS significantly increased(P<0.01)in RSV treated groups. 2. MASSON and SR staining: Compared with the normal group, DCM group showed collagen fibers increased significantly and showed a large grid shape change. Polarized light microscopy showed collagen fibers of ColⅠ,Ⅲ significantly increased in DCM group. In RSV high-dose group, ColⅠ,Ⅲ were less than DCM and low-dose group, and approaching normality. 3. In RSV low-dose group, ColⅠ,Ⅲ m RNA were lower than DCM group, but higher than normal group and high-dose group(P<0.01). SIRT1 m RNA was higher than DCM and normal group, but lower than high-dose group(P<0.01). 4. Co-Immunoprecipitation and western-blot: Compared with the normal group, expression of p-Smad3 was higher in DCM group and had no statistical significance compared with the RSV treated groups. The expression of SIRT1 was higher, and Ac-Smad3 was lower in DCM group than the normal group. In RSV low-dose group, SIRT1 was higher than DCM group but lower than high-dose group. Ac-Smad3 was lower than DCM group but higher than high-dose group.Conclusion:1. Rats model of EAM can be established by injecting the porcine cardiac myosin, and gradually develops into DCM. 2. With the development stage of EAM to DCM, necrotic area is replaced by reparative fibrosis. Collagen fibers of ColⅠ、Ⅲ significantly increase and ColⅠis sharpest rise in3.RSV can alleviate the degree of myocardial fibrosis, reduce ColⅠ,Ⅲ expression and ameliorate heart function in DCM rats. 4.SIRT1 reversed acetylation of Smad3 through inhibiting TGF-β1/Smad3 pathway by RSV. And the improvement of cardiac function degree is dose related. |
PDF Full Text Request