Yan Rui

ALTERATIONS OF THE CALRETICULIN-STAT3 PATHWAY ASSOCIATES WITH MITOCHONDRIA DAMAGE IN A RAT MODEL OF DILATED CARDIOMYOPATHY

Objectives To study the calreticulin-signal transducer and activator of transcription 3 (STAT3) signalling pathway and its effect on mitochondria damage in the progress of dilated cardiomyopathy (DCM). Methods Thirty-five male Sprague-Dawley rats were divided into three groups including the untreated group, a control group treated orally with 0.15% carboxy methylcellulose-Na solution and a model group treated with suspension of furazolidone (700 ppm) dissolved in 0.15% carboxy methylcellulose-Na for 30 weeks. The cardiac function and structure were measured using the echocardiographic and hemodynamic studies and paraffin-embedded sections staining respectively. The signal molecules involved in the calreticulin-STAT3 pathway were investigated by real-time quantitative polymerase chain reaction and western-blot. At last the cardiac mitochondria structure and function were detected. Results Compared with the control and untreated groups, the rats in the model group had enlarged left ventricular dimensions, and reduced systolic and diastolic function. Focal and diffuse areas of myocardial degeneration and interstitium fibrosis were present in the rat hearts of model group. Calreticulin mRNA expression was 3-fold higher in the model group than that in control group, and the protein level of calreticulin was also significantly higher than that in the control and untreated groups (p<0.05). The protein expression of STAT3 and p-STAT3 in the whole myocardium and cardiac mitochondria were both significantly down-regulated in the model group (p<0.05). The gene and protein levels of manganese superoxide dismutase (MnSOD), downstream to STAT3, were also significantly decreased in the model group (p<0.05). Under electron microscopic observation, the cardiac mitochondria in the model group were swelling with fractured or dissolved cristae. The mitochondrial membrane potential level of the isolated fresh cardiac mitochondria, and the enzyme activities of cytochrome c oxidase and succinate dehydrogenase in the model group were both significantly decreased as compared with control and untreated groups (p<0.05). Conclusions A rat model of DCM induced by furazolidone was successfully established. It might be that furazolidone-induced DCM is due to the alterations of calreticulin-STAT3 pathway. Down-regulated expression and activity of STAT3 can not only promote mitochondrial membrane permeability pore to open directly, but also induce mitochondrial damage indirectly through inhibiting the expression of MnSOD.

ASSA13-03-10 The Protein Expression of Mitochondrial Trx2 in Selenium Deficiency Rat Hearts and Its Effect on Mitochondria

Objectives To study the dynamic changes of thioredoxin 2 (Trx2) protein expression in the cardiac mitochondria of selenium deficiency rats and its effect on the cardiac mitochondria damage. Methods Forty-eight rats were randomised into normal control group (n = 24) and selenium deficiency model group (n = 24). When rats were fed for 10 weeks, 20 weeks, 30 weeks and 40 weeks respectively, the cardiac function was determined by carotid artery intubation. At the corresponding time points, the damage of cardiac mitochondria was observed under electron microscopy, and the mitochondrial stereological parameters including surface density (Sv), volume density (Vv) and specific surface (Rsv, surface-to-volume ratio) were further studied. The cardiac mitochondria were extracted from the rats at the corresponding time points for assessing the enzyme activities of succinate dehydrogenase (SDH) and cytochrome c oxidase, and studying the protein expression of Trx2 using western-blot. Results (1) Compared with the corresponding control group, the rats in the model group had notable decreased cardiac function, and the damage significantly aggravated with the time extension of low selenium (P, and remarkable increase in Vv in the selenium deficiency rat hearts compared with the corresponding control group (P mitochondrial stereological parameters and the enzyme activities in the model group were more notable with the time extension of low selenium (PPSv, Rsv, SDH and COX, and negative correlation with Vv (P < 0.01). Conclusions Selenium deficiency down-regulates the protein expression of mitochondrial Trx2 in the rat heart, which results in cardiac mitochondrial injury and the ultimate progress of heart failure.

GW24-e2985 Stem cell therapy: a meta-analysis of randomised Controlled trials in chronic heart failure

Objectives To evaluate whether stem cell therapy in chronic heart failure could improve cardiac function and clinical outcomes, then to realise the incidence of adverse events in the procedure. Methods A systematic literature search was conducted to identify randomised controlled trials of stem cell therapy for chronic heart failure in PubMed and Cochrane Library by independent two authors between 2001 and Dec. 2012. Reports of trials were sought that compared stem cell with optimal treatment for chronic heart failure in adults. Then according to the Cochrane Handbook for systematic reviews, we estimate the qulity of the randomised controlled trials and collect the useful information. At last, we choose the variable and process data with RevMan 5.0. Results 12 trials with data for 431 patients were identified by the literature search. The aetiology of chronic heart failure in patients were ischaemic cardiomyopathy or non-ischaemic dilated cardiomyopathy. Stem cell therapy could significantly improve the left ventricular ejection fraction compared with control treatment in chronic heart failure (weighted mean difference (WMD) 6.09, 95%CI from 3.03 to 8.78, P < 0.0001). At the same time, with stem cell therapy, the cardiac fuction (NYHA) was improved further (WMD -0.77, 95%CI from -1.28 to 0.25, P = 0.003). However, stem cell therapy could not significantly reduce the left ventricular end-diastolic volume (WMD -2.97, 95%CI from -17.88 to 11.93, P = 0.70) and end-systolic volume (WMD -2.97, 95%CI from -17.88 to 11.93, P = 0.33). Besides stem cell therapy did not show a significant protective effect for worsen heart failure (RR 0.49, 95%CI from 0.10 to 2.30, P = 0.37) and mortality (RR 0.77, 95%CI from 0.42 to 1.39, P = 0.38). Meanwhile, stem cell therapy was not associated with the significant increase of ventricular arrhythmia (RR 1.05, 95%CI from 0.56 to 1.97, P = 0.88). Conclusions Stem cell might be a more effective strategy for chronic heart failure treatment. It can bring some cardiac protection, but according to the existing data, stem cell therapy did not show the superiority for prognosis. More studies, especially larger long-term follow-up RCTs, are needed to clarify the effect and safety of stem cell in chronic heart failure.

GW24-e1158 Aliskiren/amlodipine versus aliskiren/hydrochlorothiazide in hypertension: Indirect-comparison meta-analysis of randomised controlled trials

Objectives Aliskiren, a direct renin inhibitor, is effective for reducing blood pressure (BP) in patients with hypertension when combined with a calcium channel blocker such as amlodipine or a diuretic such as hydrochlorothiazide (HCTZ). However, the efficacy and tolerability between the 2 combinations are unclear. We performed a systematic review of randomised controlled trials of aliskiren/amlodpine and aliskiren/HCTZ for hypertension. Methods The Cochrane Central Register of Controlled Trials, MEDLINE, Embase and the Novartis clinical trial database were searched through December 2012 for reports of RCTs of aliskiren/amlodpine and aliskiren/HCTZ versus monotherapy in patients with hypertension. The main outcome measures were reduction in systolic BP (SBP) and diastolic BP from baseline and rates of therapeutic response and BP control. Tolerance of aliskiren/amlodipine and aliskiren/HCTZ was also analysed. Outcomes were initially pooled by standard random-effects methods, producing a weighted mean difference (WMD) or risk ratio (RR) and 95% confidence intervals (95% CIs). The pooled estimates were then used for adjusted indirect comparisons. Results We selected 19 reports of trials involving 13,614 participants. Aliskiren/amlodpine and aliskiren/HCTZ were more effective than monotherapy in controlling BP. Aliskiren/amlodipine was significantly more effective than aliskiren/HCTZ in reducing SBP (WMD -3.36 mmHg, 95% CI -4.64–2.07 mmHg) and DBP (-3.49 mmHg, -4.34–2.63 mmHg). As compared with aliskiren/HCTZ, alikiren/amlodipine was associated with higher rate of therapeutic response (RR 1.23, 95% CI 1.14–1.33) and BP control (RR 1.24, 1.11–1.39). Number of adverse events and withdrawals due to adverse events were similar with aliskiren/amlodipine and aliskiren/HCTZ. Conclusions BP control is better with aliskiren combined with amlodipine or HCTZ than with monotherapy, aliskiren/amlodipien being more effective than aliskiren/HCTZ.

ASSA13-03-32 The Alterations of Heart Function and Cardiac Mitochondria in Selenium Deficiency Rats

Objective To study the dynamic changes of heart function and cardiac mitochondria in selenium deficiency rats. Methods Forty-eight rats were randomised into normal control group (n = 24) and selenium deficiency model group (n = 24). When rats were fed for 10 weeks, 20 weeks, 30 weeks and 40 weeks respectively, selenium levels in the rat blood were determined using fluorescence method, and heart function was measured by carotid artery intubation. At the corresponding time points, the alterations of cardiac mitochondria were observed under electron microscopy, and the mitochondrial stereological parameters including surface density (Sv), volume density (Vv) and specific surface (Rsv, surface-to-volume ratio) were further studied. The cardiac mitochondria were extracted from the rats at the corresponding time points for assessing the enzyme activities of succinate dehydrogenase (SDH) and cytochrome c oxidase (COX). Results (1) Compared with the corresponding control group, the blood selenium levels, left ventricular systolic pressure (LVSP) and maximum rate of left ventricular pressure rise (+dp/dtmax) in the model group were all decreased (Pas the time of selenium deficiency prolonged (P, and remarkable increase in Vv in the selenium deficiency rat hearts compared with the corresponding control group (Pmitochondrial stereological parameters and the enzyme activities in the model group were more notable with the time extension of low selenium (PSv, Rsv, SDH and COX, and negative correlation with Vv (P < 0.01). Conclusions Selenium deficiency leads to the damage of mitochondrial structure and function in rats, resulting in heart failure.

ASSA13-03-15 The Role of P66shc Adapter Protein in the Inhibitory Action of Curcumin on Cardiomyocyte Apoptosis Induced by AngII

Objective To explore the role of p66shc adapter protein in the cardiomyocyte apoptosis induced by AngII, and the effects of curcumin pretreatment. Methods Neonatal rat cardiomyocytes (NRCMs) were prepared from 1 to 2 days old Sprague-Dawley rats, and were randomly divided into five groups, including normal control group, 10–11M AngIIgroup, 10–9M AngIIgroup, 10–7M AngIIgroup, and 10–7M AngII+curcumin group. The cell viability was measured by MTT. The level of reactive oxygen species (ROS) in the whole cell and cell apoptosis rate were measured by the flow cytometry. Mitochondrial membrane potential (MMP) was detected using a fluorescence microplate reader, and the protein expression of phosphorylated and total p66shc was detected using western blot. Results With the increasing AngIIconcentration on NRCMs, cell viabilities and MMP levels were gradually decreased, and the levels of ROS in the cardiomyocytes and the cell apoptosis rates were both increased (P < 0.05). Moreover, the pretreatment of curcumin could significantly attenuate the cardiomyocyte injury induced by AngII (P < 0.05). The protein expression of phosphorylated p66shc in the whole cell lysates and total p66shc in the mitochondria were both increased in a dose-dependent manner when NRCMs were exposed to 10–11 to 10–7M AngII for 24h (P < 0.05). When NRCMs were exposed to 10–7M AngII, the pretreatment of curcumin could significantly down-regulate the protein expression of phosphorylated p66shc in the whole cell lysates and total p66shc in the mitochondria (P < 0.05). Conclusions p66shc plays an important role in the cardiomyocyte apoptosis induced by AngII, and curcumin could attenuate AngII induced cardiomyocyte injury through down-regulating the protein expression of p66shc.