感染柯萨奇病毒B3诱导人心肌纤维细胞因子的产生

目的 :CVB3感染可导致严重的心脏病 ,其机制尚不清楚 ,细胞因子可能有重要作用 ,但确切来源细胞尚不清楚 ,心肌纤维细胞是主要间质分子 ,感染CVB3后检测其细胞因子的产生。方法 :采用ELISA方法检测了感染CVB3心肌纤维细胞培养上清液IL 6、IL 8、IL 1α、IL 1β和TNF α的产生。 结果 :发现感染CVB32 4小时后IL 6和IL 8即明显升高 (P <0 0 1) ,96小时后IL 1α有所升高 (P <0 0 5 ) ,IL 1β和TNF α无明显变化。 结论 :IL 6、IL 8和IL 1α在CVB3心肌炎中可能有一定作用。

柯萨奇病毒B3诱导人心肌纤维细胞因子的产生

目的 探讨柯萨奇病毒与心肌炎的关系。方法 采用ELISA方法检测了感染CVB3心肌纤维细胞培养上清液IL - 6、IL - 8、IL - 1α、IL - 1β和TNF -α的产生。 结果 发现感染CVB32 4h后IL - 6和IL - 8明显升高 (P <0 .0 1) ,96h后IL - 1α有所升高 (P <0 .0 5 ) ,IL - 1β和TNF -α无明显变化。 结论 IL - 6、IL - 8和IL -

心肌纤维母细胞的自分泌/旁分泌作用

心肌纤维母细胞在调节正常心肌功能和干预异常心肌重塑中都起着极其重要的作用。除了合成和降解细胞外基质,心肌纤维母细胞还产生各种生物活性分子,包括细胞因子,血管活性肽和生长因子。这些生物活性分子经自分泌/旁分泌途径、信号转导途径和基因水平调控等调节机制,维持心脏正常的结构、机械、生物化学及电活动。

miR-21在恩度联合X线照射心肌纤维母细胞的作用

目的初步研究恩度联合X线照射对心肌纤维母细胞(CF)影响及miR-21的作用。方法使用大鼠CF进行实验,设空白对照组、10Gy X线照射组、恩度组、10Gy X线+恩度组、10Gy X线+恩度+NC mimics组(阴性对照组1)、10Gy X线+恩度+miR-21 mimics组、10Gy X线+恩度+NC抑制剂组(阴性对照组2)、10Gy X线+恩度+miR-21抑制剂组。MTT法检测CF增殖,蛋白印迹法检测胶原蛋白I(CollagenⅠ)的表达、q-PCR检测CollagenⅠ和miR-21 mRNA的表达。结果与空白对照组、10Gy X线+恩度组及阴性对照组1比较,10Gy X线+恩度+miR-21 mimics组CF增殖及CollagenⅠmRNA、miR-21 mRNA表达增加(均P<0.05)。与空白对照组、10Gy X线+恩度组及阴性对照组2比较,10Gy X线+恩度+miR-21抑制剂组的CF增殖及CollagenⅠmRNA表达降低(均P<0.05)。结论模拟miR-21基因表达CF增殖和CollagenⅠ表达增加,抑制该基因表达CF增殖和CollagenⅠ表达降低。

心肌纤维化与慢性充血性心力衰竭研究进展

心肌纤维化是由多种病理因素导致心脏疾病发展至一定阶段所具有的共同病理改变,是心室重构的主要原因。心肌纤维化与高血压性心脏病、缺血性心肌病、肥厚型心肌病、扩张性心肌病、病毒性心肌炎及糖尿病心肌病等多种心血管疾病密切相关。本文从肾素—血管紧张素—醛固酮系统、心肌纤维化相关调控细胞因子、炎症因子及血管内皮生长因子等方面就心肌纤维化与慢性充血性心力衰竭相关研究进展进行综述。

Expression of VEGF, b-FGF, and their receptors after injection of VEGF on ischemic heart muscle

Objective: To study the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) and their receptors after injection of external VEGF on ischemic heart muscle and to investigate the mechanism of therapeutic myocardial angiogenesis of VEGF. Methods: Standard experimental pigs underwent placement of a left circumflex artery ameroid occluder. Six weeks later, the animals in the experimental group were treated with VEGF (20 μg) by direct epicardial injection (n=8) and other animals in the control group did not receive any treatment (n=8). Four weeks after therapy, the animals were evaluated with regard to mRNA and protein expression of VEGF and b-FGF and their receptors by RT-PCR and Western blotting. Results: The mRNA expression of VEGF and b-FGF and their receptors by RT-PCR expressing as percentage of density ratio to the GAPDH control was increased in experimental group versus control group. The protein expression of VEGF and b-FGF and their receptors by Western blot expressing as percentage of density ratio to the Commassie Blue control was increased in experimental group versus control Group. Conclusion: Exogenous VEGF can induce the expression of endogenous VEGF, b-FGF, and their receptors; b-FGF may play a role in the angiogenesis of VEGF.

Mechanical stretch induces mitochondria-dependent apoptosis in neonatal rat cardiomyocytes and G_(2)/M accumulation in cardiac fibroblasts

Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study, a well-described in vitro sustained stretch model was employed to study mechanical stretch-induced responses in both neonatal cardiomyocytes and cardiac fibroblasts. Cardiomyocytes, but not cardiac fibroblasts, underwent mitochondria-dependent apoptosis as evidenced by cytochrome c (cyto c) and Smac/DIABLO release from mitochondria into cytosol accompanied by mitochondrial membrane potential (△ψ_m) reduction, indicative of mitochondrial permeability transition pore (PTP) opening. Cyclosporin A, an inhibitor of PTP, inhibited stretch-induced cyto c release, △ψ_m reduction and apoptosis, suggesting an important role of mitochondrial PTP in stretch-induced apoptosis. The stretch also resulted in increased expression of the pro-apoptotic Bcl-2 family proteins, including Bax and Bad, in cardiomyocytes, but not in fibroblasts. Bax was accumulated in mitochondria following stretch. Cell permeable Bid-BH3 peptide could induce and facilitate stretch-induced apoptosis and △ψ_m reduction in cardiomyocytes. These results suggest that Bcl-2 family proteins play an important role in coupling stretch signaling to mitochondrial death machinery, probably by targeting to PTP. Interestingly, the levels of p53 were increased at 12 h after stretch although we observed that Bax upregulation and apoptosis occurred as early as 1 h. Adenovirus delivered dominant negative p53 blocked Bax upregulation in cardiomyocytes but showed partial effect on preventing stretch-induced apoptosis, suggesting that p53 was only partially involved in mediating stretch-induced apoptosis. Furthermore, we showed that p21 was upregulated and cyclin B1 was downregulated only in cardiac fibroblasts, which may be associated with G_2/M accumulation in response to mechanical stretch.

Cardiac Tissue Engineering with the Aid of Polyhydroxybutyrate Membranes and Nanofibers

The PHB （polyhydroxybutyrate） films were reported recently as promising materials for tissue involving cultivation of dermoblasts, fibroblasts and connective tissue. In the present work, the authors studied PHB scaffolds for the cardiac tissue engineering, either in a form of thin membranes or electrospun fiber mats. The results show that cardiac cells of various origins can be successfully grown on PHB substrates, in the both forms： membrane and nanofiber matrix. Functioning of obtained tissue patches was tested by visual observation of contractions and with the aid of optical mapping, i.e., registration of excitation waves with fluorescent markers. The latter one allowed ensuring the fact that cultured cells represented electrophysiological syncytium, and the PHB scaffold showed its full compatibility with the excitability of cardiac cells.

Apoptosis,myocardial fibrosis and angiotensin Ⅱ in the left ventricle of hypertensive rats treated with fosinopril or losartan

Objective To investigate the different effects of an angiotensin Ⅱ type 1 (AT 1) receptor antagonist, losartan, and an angiotensin converting enzyme (ACE) inhibitor, fosinopril, on cardiomyocyte apoptosis, myocardial fibrosis, and angiotensin Ⅱ (AngⅡ) in the left ventricle of spontaneously hypertensive rats (SHRs) Methods SHRs of 16 week old were randomly divided into 3 groups: SHR L (treated with losartan, 30 mg·kg 1 ·d 1 ), SHR F (treated with fosinopril, 10 mg·kg 1 ·d 1 ), and SHR C (treated with placebo) Each group consisted of 10 rats Five rats, randomly selected from each group, were killed at the 8th and 16th week after treatment Cardiomyocyte apoptosis, collagen volume fraction (CVF), perivascular collagen area (PVCA) and AngⅡ concentrations of plasma and myocardium were examined Results Compared with the controls at the 8th and 16th week, systolic blood pressures were similarly decreased in both treatment groups Left ventricular weight and left ventricular mass indexes were significantly lower in both treatment groups However, the latter parameter at the 16th week was reduced to a less extent in the fosinopril group than that in the losartan group Compared with the controls, cardiomycyte apoptotic index was significantly reduced at the 8th week only in the fosinopril group, and at the 16th week in both treatment groups The index of the fosinopril group was lower than that of the losartan group at the latter endpoint examined Compared with the controls, the left ventricular collagen volume fraction and perivascular collagen area at the 8th and 16th weeks were significantly reduced in the SHRs treated with either fosinopril or losartan However, the collagen volume fraction at the latter endpoint in the fosinopril group was lower than that in the losartan group Compared with the controls at endpoints, plasma and myocardium Ang Ⅱ levels were significantly increased in the losartan group However, plasma Ang Ⅱ concentrations were not altered, and myocardium AngⅡ concentrations at the 8th and 16th weeks were significantly reduced in the fosinopril group Conclusions Both losartan and fosinopril could effectively inhibit cardiomyocyte apoptosis and myocardial fibrosis and reverse heart hypertrophy Fosinopril may be more effective in these cardioprotective effects, suggesting that the effects of both drugs are related to the inhibition of myocardium renin angiotension aldsterone system

Hydrogen sulfide suppresses transforming growth factor-β1-induced differentiation of human cardiac fibroblasts into myofibroblasts

In heart disease, transforming growth factor-β1 （TGF-β1） converts fibroblasts into myofibroblasts, which synthesize and se- crete fibrillar type I and III collagens. The purpose of the present study was to investigate how hydrogen sulfide （HzS） sup- presses TGF-~l-induced differentiation of human cardiac fibroblasts to myofibroblasts. Human cardiac fibroblasts were se- rum-starved in fibroblast medium for 16 h before exposure to TGF-β1 （10 ng mL-1） for 24 h with or without sodium hydrosul- fide （NariS, 100 μmol L-1, 30 min pretreatment） treatment. NariS, an exogenous HzS donor, potently inhibited the prolifera- tion and migration of TGF-β1-induced human cardiac fibroblasts and regulated their cell cycle progression. Furthermore, NariS treatment led to suppression of fibroblast differentiation into myofibroblasts, and reduced the levels of collagen, TGF-β1, and activated Smad3 in TGF-β1-induced human cardiac fibroblasts in vitro. We therefore conclude that H2S sup- presses TGF-β1-stimulated conversion of fibroblasts to myofibroblasts by inhibiting the TGF-β1/Smad3 signaling pathway, as well as by inhibiting the proliferation, migration, and cell cycle progression of human cardiac myofibroblasts. These effects of H2S may play significant roles in cardiac remodeling associated with heart failure.

miRNA-711-SP1-collagen-I pathway is involved in the anti-fibrotic effect of pioglitazone in myocardial infarction

Although microRNAs （miRNAs） have been intensively studied in cardiac fibrosis, their roles in drug-mediated anti-fibrotic therapy are still unknown. Previously, Pioglitazone attenuated cardiac fibrosis and increased miR-711 experimentally. We aimed to explore the role and mechanism of miR-711 in pioglitazone-treated myocardial infarction in rats. Our results showed that pioglitazone significantly reduced collagen-I levels and increased miR-711 expression in myocardial infarction heart. Pioglitazone increased the expression of miR-711 in cardiac fibroblasts, and overexpression of miR-711 suppressed collagen-I levels in angiotensin II （Ang II）-treated or untreated cells. Transfection with antagomir-711 correspondingly abolished the pioglitazone-induced reduction in collagen-I levels. Bioinformatics analysis identified SP1, which directly promotes collagen-I synthesis, as the putative target of miR-711. This was confirmed by luciferase assay and western blot analysis. Additionally, increased SP1 expression was attenuated by pioglitazone in myocardial infarction heart. Furthermore, transfection of antago- mir-711 attenuated pioglitazone-reduced SP1 expression in cardiac fibroblasts with or without Ang II stimulation. We conclude that pioglitazone up-regulated miR-711 to reduce collagen-I levels in rats with myocardial infarction. The miR-711-SPl-collagen-I pathway may be involved in the anti-fibrotic effects of pioglitazone. Our findings may provide new strategies for miRNA-based anti-fibrotic drug research.