Chinese Medicine Monomer Ctnt <sup> R141w </ Sup> Transgenic Dilated Cardiomyopathy Mouse Model Of Therapeutic Effect And Mechanism Study

The effects and mechanisms of ginsenoside-Rbl on DCM in the cTnTK141W transgenic mouseBackgroud The researches of inhibition of cardiac remodeling by drugs have been developed rapidly in recent years. It has been found that many effective components in Chinese herb could prevent the development of cardiac remodeling especially left ventricular hypertrophy, which occurred in hypertension, myocardial infarcion. But the study about the medicinal therapy for DCM was absent. Here, using the cTnTR141W transgenic mouse model of DCM, tetramethylpyrazine phosphate (TMPP) or ginsenoside-Rb1 were screening out from 11 kinds of compounds from Chinese herbs which showed beneficial effect on cardiovascular diseases, as the potential drugs for prevention of cardiac dysfunction and dilation in DCM. We further studied the effects and the possible underlying mechanisms of Rbl on cardiac remodeling of dilated cardiomyopathy in cTnTR141W transgenic mouse.Methods We performed M-mode echocardiography in aMHC-cTnTR141W transgenic mice at the ages of 2 months, which is considered the predilated stage of DCM. We determined the mean and the 95%confidence interval (CI) of the left ventricular internal diameter at end-systole (LVIDs) in the transgenic mice. We used the upper limit of the 95%CI as the evidence for cardiac dilation and excluded the cTnTR141W mice with no significantly phenotype of DCM. The remainder transgenic mice were randomized to model group or drug group (Rb1,70 mg/Kg/d). Age-matched nontransgenic mice drinking water were used as wild type control. The drug was administered for 7 months. We detected the cardiac function and geometry by echocardiography once 1 month. Histology and transmission electron microscopy were used to assess myocardial organization, myocardial interstitial fibrosis and ultrastructure. The expression of adhesion proteins was detected by RT-PCR. Immunofluorescence was performed to examine localization of Itga8. The expression of HB-EGF, pSTAT3 and STAT3 were detected by western blot.Results We found that long-term administration of ginsenoside-Rb1 significantly improved cardiac function and reduced mortality by 50%. The HW/BW ratio of Rbl-treated mice was significantly lower than that of placebo mice (11.3%, P< 0.05). Histological analysis showed that Rb1 attenuated the myocardial disarray, decreased the interstitial fibrosis, and ultrastructural abnormality in the cTnTR141W heart. RT-PCR revealed that the expression of Cx40, E-cad, itga8 and itgb 1 bp3 were turned over to nearly normal levels in the Rb1 group, while the decreased expression of Cx40 and the increased expression of E-cad, itga8 and itgb 1 bp3 were detected in the placebo group. Confocal immunofluorescence showed that Rb1 regulated the distribution of Itga8. Western blot analysis indicated that Rb1 treatment significantly downregulated HB-EGF and pSTAT3 expression, which were steadily overexpressed in the placebo mice.Conclusion We showed that Rb1 and TMPP could be the potential drugs for DCM therapy. These findings revealed that Rb1 could improve cardiac function and inhibit cardiac remodeling of DCM in cTnTR141W transgenic mice, partly through regulating adhesion proteins expression and downregulated the HB-EGF expression and STAT3 activation during development of dilated cardiomyopathy in the cTnTR141W transgenic mice. The effects and mechanisms of tetramethvlpvrazine phosphate on DCM in the cTnTR141w transgenic mouseBackground and purpose:Dilated cardiomyopathy (DCM) is the most common cause of heart failure. Familial DCM (FDCM) may account for 20-48%of DCM, and specific medicines for its treatment are not currently available. Tetramethylpyrazine (TMP) has been shown to provide a substantial cardioprotective effect. In the present study, we used the cTnTR141W transgenic mouse model to test the effect of tetramethylpyrazine phosphate (TMPP) on FDCM.Experimental approach:We evaluated the effect of TMPP on cardiac function and geometry by M-mode echocardiography once a month after randomization. The cardiac hypertrophic markers were analyzed, the microstructure and ultrastructure of heart were observed, and the expression and localization of structural proteins were detected in the mice aged 6 months. In addition, CaM/CaMK II signaling pathway was investigated as the possible intracellular mechanism.Key results:TMPP significantly improved cardiac function and decreased mortality of cTnTR141W mice by 54% after 7 months of treatment. The HW/BW ratio, and gene expression of hypertrophic markers (NPPB, ACTA1) in cTnTR141W mice was decreased remarkedly by TMPP treatment. Histologic analysis showed that TMPP reduced myocyte disarray, interstitial fibrosis and ultrastructural abnormality in cTnTR141W mice. Western blot and immunofluorescence analysis indicated that TMPP decreased the expression of sarcomeric protein myotilin while increasing the expression of MLC2 in cTnTR141w mice. RT-PCR revealed an inhibition effect of TMPP on CaM/CaMKâ…¡signaling pathway.Conclusions and implications:TMPP was shown to prevent heart failure and left ventricular remodeling in the cTnTR141W transgenic mouse of DCM, and it mechanism may be related to its inhibition of CaM/CaMK II signaling pathway.Abbreviations:DCM, dilated cardiomyopathy; FDCM, familial DCM; cTnT, cardiac troponin T; TMPP, Tetramethylpyrazine phosphate; HW/BW, heart weight/body weight; The establishment of heart specific NOL3 gene transgenic miceObjective To establish nucleolar protein 3 (NOL3) transgenic mice and investigate its effect on the development of cardiomyopathy.Methods The NOL3 expression in the different tissues and different ages of mice was detected with western blot. Transgenic mice were generated by the method of microinjection. The genotype of transgenic lines was identified by PCR. The cardiac function and geometry were detected by echocardiography.Results The western blot analysis showed that NOL3 was expressed in quite higher levels in the tissues of heart, muscle and brain than in other tissues. The NOL3 expression in the heart maintained a high level from newborn to adult. Three founders of hearts specific a-MHC-NOL3 transgenic mice were established and one high-level expression line was identified. The transgenic gene itself did not affect the cardiac function and geometry compared with the wild type mice.Conclusion The transgenic mice with cardiac-specific expression of the human NOL3 gene were established successfully and it can be used to cross with the DCM and HCM models to investigate the function of NOL3 gene on the development of cardiomyopathy.