Protective action of tetramethylpyrazine phosphate against dilated cardiomyopathy in cTnT(R141W) transgenic mice
ACTA PHARMACOLOGICA SINICA
Authors: Zhao, Hai-ping; Lue, Dan; Zhang, Wei; Zhang, Li; Wang, Shu-mei; Ma, Chun-mei; Qin, Chuan; Zhang, Lian-feng
Abstract
Aim: Dilated cardiomyopathy (DCM) is the most common cause of heart failure, and pharmacological intervention is not currently available. Here we investigate the effect of tetramethylpyrazine phosphate (TMPP) on the progression of DCM in the cTnT(R141W) transgenic mouse model. Methods: The cTnT(R141W) transgenic mice aged 2 months were divided into model group and TMPP group, whereas age-matched non-transgenic mice were used as wild-type control. TMPP 45 mg.kg(-1).d(-1) was administered for 7 months. Following assessment of cardiac function by echocardiography, cardiac tissues were prepared for histology and electron microscopy. Levels of molecular markers for cardiomyocyte hypertrophy and fibrosis were detected by RT-PCR. Expression of structural proteins of the sarcomere and intercalated disc was determined by Western blot. Results: TMPP significantly prevented cardiac dilatation and dysfunction with the development of DCM, and decreased mortality by 54%. TMPP decreased HW/BW ratios and expression of hypertrophic markers BNP and ACTA1, as well as reduced interstitial collagen deposition and expression of profibrotic markers Col1a1 and Col3a1. TMPP attenuated ultrastructural disruption caused by cTnT(R141W) expression and decreased expression of structural proteins myotilin and E-cadherin which were up-regulated in the cTnT(R141W) heart. Moreover, TMPP reduced the mRNA expression of Calm1 and Camk2b in the cTnT(R141W) heart. Conclusion: Our results suggest that TMPP could be a promising drug for prevention and treatment of DCM.
The significance of low plasma miR-335 level in patients with acute cerebral infarction may be associated with the loss of control of CALM1 expression
INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL MEDICINE
Authors: Yuan, Mei; Yuan, Haijun; Zhou, Chengfang; Liu, Feng; Lin, Chen; Tang, Yonghong
Abstract
Calcium overload, mediated by calmodulin (CaM), plays an important role in ischemia/reperfusion injury during acute ischemic brain damage. However, the regulation of CaM expression in cerebral ischemia is still not fully addressed. This study showed that the levels of plasma miR-335 were significantly down-regulated in 152 patients with acute cerebral infarction (0.60 +/- 0.31) compared to 136 age-matched healthy controls (1.16 +/- 0.30) (P < 0.01). Moreover, the levels negatively correlated with the National Institutes of Health Stroke Scale (NIHSS) scores in acute cerebral infarction patients (r = -0.680; P < 0.01). Transfection of miR-335 mimics and inhibitors inhibited CALM1 mRNA and CaM protein expressions in HUVECs. This study suggests that miR-335 is an important biomarker of acute cerebral infarction, and which functions are through regulating the expression of the CALM1 gene during acute ischemic brain injury. Our findings highlighted the potential of miR-335 as a target to develop agents to treat acute cerebral infarction.