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1.
心肌肥大是心肌细胞面对多种病理刺激时的共同反应,以心肌细胞体积增大和胚胎期基因的重新表达为标志.心肌发育调控基因肌肉LIM蛋白(muscle LIM protein,MLP)的表达异常与心肌肥大有关.为研究MLP参与心肌肥大发生的分子机制,采用去氧肾上腺素(phenylephrine, PE)刺激大鼠原代培养心肌细胞,建立心肌细胞肥大模型,采用RNAi技术敲减MLP的表达,分析MLP与肥大信号通路钙调神经磷酸酶(calcineurin)/活化T细胞核因子(nuclear factor of activated T-cells, NFAT)的关系.结果显示, 原代培养的心肌细胞经一定浓度的PE刺激后细胞表面积增加,肥大标志蛋白ANP、BNP表达增高,并伴有MLP表达上调. RNAi方法敲减MLP的表达则明显抑制PE诱导的心肌细胞表面积增加和BNP表达增高,并且直接 影响NFAT的转录激活活性,提示MLP与心肌肥大的发生密切相关,并且可能是通过calcineurin/NFAT信号通路而参与心肌肥大的发生.  相似文献   

2.
心肌肥厚过程中PKC的双刃剑作用   总被引:2,自引:0,他引:2  
Yu ZB  Wang YY  Zhang R 《生理科学进展》2007,38(4):339-342
在慢性压力超负荷致心肌肥厚过程中,蛋白激酶C(PKC)是促心肌细胞肥大信号转导通路上的关键分子。心肌中PKC存在多种异构体,其各自的功能与作用尚不清楚。借助于PKC的选择性激动剂与抑制剂、腺病毒转染或转基因模型的研究表明,不同种属心肌中共同拥有的PKC有四种,它们的作用分别为:PKCε、PKCβ与PKCδ均可独立介导心肌细胞肥大,相互间能发挥代偿作用;激活PKCα与PKCβ亦可导致心肌收缩性能降低,相反,激活PKCε可增强心肌收缩性能。PKC的这种既可促进心肌发生代偿性肥厚,又可降低心肌收缩性能而引起失代偿的双重作用,在肥厚心肌向心衰转化过程中值得关注。  相似文献   

3.
肌纤基因调节因子(myofibrillogenesis regulator1,MR1)是首次从人体骨骼肌cDNA文库中分离得到的基因.以前的研究证明MR1能够介导血管紧张素Ⅱ(AngⅡ)诱导的体内外心肌肥厚效应,但相关分子机制有待进一步阐明.利用腺病毒载体在小鼠中沉默MR1表达,利用基因芯片对比检查了小鼠心肌基因表达谱的变化.结果发现,在AngⅡ诱导心肌肥厚的小鼠,沉默MR1前后出现明显的信号通路方面的变化和基因表达差异,其中沉默MR1后表达降低90%以上的基因有39个,而表达升高10倍以上的基因有5个.在这些基因中,对与心肌肥厚密切相关的基因进行了定量RT-PCR检测,以进一步验证基因芯片的结果,发现沉默MR1后HSP72和硫氧还蛋白1(Trx1)均表达升高,而钙调神经磷酸酶β(CnAβ)和β肌球蛋白(β-myosin)的基因表达则受抑制.这些信号通路和基因均与AngⅡ诱导的心肌肥厚有一定的关系,为揭示MR1在AngⅡ所致心肌肥厚中的作用和分子机制提供了新的证据.  相似文献   

4.
病理性心肌肥厚是心肌细胞受到多种因素刺激后所产生的失代偿性反应,最终可演变为心力衰竭,甚至诱发猝死。鉴于其复杂的病理过程,具体发病机制至今尚未完全阐明,但既有研究已明确有丝分裂原活化蛋白激酶信号通路、Ca~(2+)介导的信号通路、蛋白激酶信号通路、Janus激酶/信号转导子和转录激活子信号通路和MicroRNAs信号通路在调控心肌肥厚的进程中起着至关重要的作用。现就相关信号通路在心肌肥厚发生、进展及预后中所起作用的最新研究进展予以综述。  相似文献   

5.
林瑶  牛勃  解军  颜真 《生命科学研究》2006,10(3):224-227
采用差速贴壁法体外原代培养大鼠心肌细胞;NPY刺激培养的心肌细胞增殖;RNA干涉特异性抑制CaN的活性,阻断NPY刺激的心肌细胞中Ca2 /CaM-CaN信号转导通路;观察对CaN活性、表达水平和心肌细胞蛋白合成速率的变化.实验结果显示NPY可增加心肌细胞的CaN活性和表达,加快细胞内蛋白合成速率.RNA干涉抑制CaN活性后,明显降低NPY刺激的蛋白合成速率.CaN参与了NPY刺激的心肌细胞增殖,RNA干涉通过抑制CaN的活性可阻断N PY诱导的心肌细胞肥大Ca2 /CaM-CaN通路.  相似文献   

6.
介导心肌肥大的一条新的信号通路--Calcineurin通路   总被引:4,自引:0,他引:4  
Fu MG  Liu NK  Tang CS 《生理科学进展》2000,31(2):147-149
心肌肥大是心肌细胞对外界刺激,如工作负荷、神经体液因子及内在心肌蛋白遗传突变一种基本应答。已知胞内Ca^2+浓度升高在各种刺激诱导心肌肥大的信号传递中起重要作用,但对Ca^2+信号下游的传递机制一直不甚清楚。新近研究证实,由Ca^2+活化的钙调神经磷酸酶(CaN)在心肌肥大的信号传递中起重要作用,基可能是Ca^2+信号致肥大基因活化的偶联环节。抑制CaN活性可阻滞各种因素诱导的心肌肥大发生与发展,  相似文献   

7.
适宜的运动负荷可刺激心肌生理性肥大和心肌细胞增殖,但这种内源性生理过程的分子机制知之甚少,因此有氧运动诱导心肌肥大和心肌细胞增殖的研究是目前发育生物学和细胞生物学领域的热点,其具体分子机制以及生理价值具有重要的生物学和医学研究及应用意义。该文综述了近年来有氧运动诱导心肌肥大和心肌细胞增殖的研究进展,旨在为相关领域的研究提供参考。  相似文献   

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10.
本工作在大体动物模型、细胞及分子水平上,对钙调神经磷酸酶(CaN)依赖的信号通路在大鼠豳肥大中的作用及其调节机制进行了研究。结果发现;(1)CaN信号通路参与血流动力学超负荷、心肌纤维化、旁/自分泌因子等诱导的心肌细胞肥大;(2)CaN信号通道参与血管紧张素Ⅱ(AngⅡ)及碱性成纤维细胞因子(bFGF)诱导的心肌细胞肥大和AngⅡ及bFGF刺激的心脏成纤维细胞增殖;(3)CaN通路与丝裂素活化蛋白激酶(MAPK)及蛋白激酶C(PKC)信号途径可能存在相互关系;(4)CaN的活化依赖胞内Ca^2 浓度的持续升高,CaN的活化还受蛋白激酶磷酸化的调节,AngⅡ刺激心肌细胞CaNmRNA的表达显著增加,CaNmRNA本身的表达受Ca^2 信号及MAPK级联反应的调控。结论:Ca^2 -CaN信号通路介导心肌肥大的发生。  相似文献   

11.
Recent in vitro studies suggest that adenosine monophosphate (AMP)-activated protein kinase (AMPK) exerts inhibitory effects on cardiac hypertrophy. However, it is unclear whether long-term activation of AMPK will affect cardiac hypertrophy in vivo. In these reports, we investigate the in vivo effects of long-term AMPK activation on cardiac hypertrophy and the related molecular mechanisms. To examine the effects of AMPK activation in the development of pressure overload-induced cardiac hypertrophy, we administered 5-aminoimidazole 1 carboxamide ribonucleoside (AICAR, 0.5 mg/g body wt), a specific activator of AMPK, to rats with transaortic constriction (TAC) for 7 weeks. We found that long-term AMPK activation attenuated cardiac hypertrophy, and improved cardiac function in rats subjected to TAC. Furthermore, long-term AMPK activation attenuated protein synthesis, diminished calcineurin-nuclear factor of activated T cells (NFAT) and nuclear factor kappaB (NF-kappaB) signaling in pressure overload-induced hypertrophic hearts. Our in vitro experiments further proved that activation of AMPK by infection of AdAMPK blocked cardiac hypertrophy and NFAT, NF-kappaB, and MAPK signal pathways. The present study demonstrates for the first time that pharmacological activation of AMPK inhibits cardiac hypertrophy in through blocking signaling transduction pathways that are involved in cardiac growth. It presents a potential therapy strategy to inhibit pathological cardiac hypertrophy by increasing the activity of AMPK.  相似文献   

12.
目的:探讨miRNAs(miR199a-5P、miR206、miR133a-3P、miR499-5P)在异丙肾上腺素(ISO)诱导大鼠心肌肥厚模型组中的表达变化;并运用生物信息学方法分析相关的主要信号通路及分子机制。方法:将16只SD雄性大鼠随机分为2组:对照组和ISO模型组,模型组给予ISO(1 mg/kg)诱导心肌肥厚模型,对照组给予等量生理盐水,均采用背部皮下多点注射。连续给药10 d后采用超声心动图测量舒张期室间隔厚度(IVSd)、舒张期左室后壁厚度(LVPWd)、左室舒张末期内径(LVDd)及心脏收缩功能(EF%);称量心脏重量(HW)、大鼠体重(BW),并计算心脏/体重比(HW/BW);心肌组织HE染色,Image J分析软件测量心肌细胞表面积;RT-qPCR检测大鼠心肌组织中4种miRNAs的表达情况。运用Targetscan、miRDB、miRwalk 数据库预测大鼠4种miRNAs可能的靶基因,FunRich软件分析预测靶基因相关的信号通路。结果:与正常组相比,模型组IVSd、LVPWd增厚,LV增大,EF%明显降低;HW、HW/BW增加;模型组心肌细胞体积明显增大,排列紊乱,细胞表面积增加;模型组miR199a-5P、miR206表达上调(P<0.05);miR133a-3P、miR499-5P表达下调(P<0.05)。应用生物信息学预测4种miRNAs的靶基因可能参与心肌肥厚相关的信号通路主要有:VEGF/VEGFR信号通路、ErbB受体信号通路等。结论:ISO诱导心肌肥厚导致miRNAs表达的改变,生物信息学预测4种miRNAs参与心肌肥厚相关的靶基因及其主要信号通路,这些研究为心肌肥厚的调控机制及其防治措施提供了新思路。  相似文献   

13.
Hong HM  Song EJ  Oh E  Kabir MH  Lee C  Yoo YS 《Proteomics》2011,11(2):283-297
It is well known that the two chemical compounds endothelin-1 (ET-1) and isoproterenol (ISO) can individually induce cardiac hypertrophy through G protein-coupled receptors in cardiomyocytes. However, the cardiac hypertrophy signaling pathway activated by ET-1 and ISO is not well defined. Therefore, we investigated the protein expression profile and signaling transduction in HL-l cardiomyocyte cells treated with ET-1 and ISO. Following separation of the cell lysates by using 2-DE and silver staining, we identified 16 protein spots that were differentially expressed as compared to the controls. Of these 16 spots, three changed only after treatment with ET-1, whereas four changed only after treatment with ISO, suggesting that these two stimuli could induce different signaling pathways. In order to reveal the differences between ET-1- and ISO-induced signaling, we studied the different events that occur at each step of the signaling pathways, when selected biocomponents were blocked by inhibitors. Our results indicated that ET-1 and ISO used different pathways for phosphorylation of glycogen synthase kinase-3β (GSK3β). ET-1 mainly used the mitogen-activated protein kinase and phosphatidylinositol-3-kinase/AKT pathways to activate GSK3β, whereas under ISO stimulation, only the phosphatidylinositol-3-kinase/AKT pathway was required to trigger the GSK3β pathway. Furthermore, the strength of the GSK3β signal in ISO-induced cardiac hypertrophy was stronger than that in ET-1-induced cardiac hypertrophy. We found that these two agonists brought about different changes in the protein expression of HL-1 cardiomyocytes through distinct signaling pathways even though the destination of the two signaling pathways was the same.  相似文献   

14.
Cardiac hypertrophy is a physiological adaptive response of the heart to diverse pathophysiological stimuli. Initially, it may be adaptive to normalize wall stress and to preserve contractile performance. This adaptive process may gradually progress to dilated cardiomyopathy, fibrotic diseases, arrhythmia, heart failure and even sudden death. Although various molecular pathways responsible for the coordinated control of the hypertrophic program, little is known about their underlying molecular mechanisms. Very recently, increasing evidence showed that miRNAs are key modulators of both cardiovascular development and function, which govern the process of cardiac hypertrophy and heart failure. MicroRNAs (miRNAs) act in a complex functional network in which each single miRNAs might control thousands of distinct target genes, and each single protein-coding gene can be regulated by many different miRNAs. Identifying the roles of miRNAs, their target genes and signaling pathways in cardiac hypertrophy by bioinformatic analysis will provide more insight into the molecular mechanisms underlying this disease process. Currently, bioinformatics resource such as GO and KEGG was applied to describe the miRNAs target genes function and identify the mRNA interaction networks that are responsible for various cellular processes. It provides a useful approach to observe the function of microRNA in physiological and pathological conditions. In this review, we will give a discussion on the dysregulation of specific miRNAs in cardiac hypertrophy and signaling pathways linking the hypertrophy-regulating miRNAs to the pathological process of cardiac hypertrophy. Finally, we place special emphasis on the essential role of bioinformatics analysis to predict the target genes and miRNAs gene networks.  相似文献   

15.
The heart responds to an increased demand arising due to physiological stimuli or pathological insults by hypertrophy of myocytes. Reactive oxygen species (ROS) have recently been identified as the molecular intermediates in the translation of mechanical stimuli to cellular response. Different signal transduction pathways have been implicated with cardiac hypertrophy, prominent among them being, mitogen-activated protein kinase (MAPK), protein kinase C (PKC) and calcineurin. It remains unclear whether the ROS induced hypertrophy is mediated through one or more of these pathways. This study was taken up with the objective to affirm the role of ROS in the induction of cardiomyocyte hypertrophy and examine the contribution of specific pathways in the mediation of the hypertrophic response. The cellular response to enzyme-generated reactive oxygen species was examined in cultured cells from newborn rat heart. Pathway specific inhibitors were used to identify the role of each pathway in the mediation of cellular hypertrophy. Cellular hypertrophy in response to hypoxanthine-xanthine oxidase was prevented by inhibition of any one of the pathways; leading to the inference that oxidative stress induced hypertrophy is mediated by coordinative regulation of the three major pathways.  相似文献   

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Cardiac hypertrophy is enlargement of the heart in response to physiological or pathological stimuli, chiefly involving growth of myocytes in size rather than in number. Previous studies have shown that the expression pattern of a group of genes in hypertrophied heart induced by pressure overload resembles that at the embryonic stage of heart development, a phenomenon known as activation of the "fetal gene program". Here, using a genome-wide approach we systematically defined genes and pathways regulated in short- and long-term cardiac hypertrophy conditions using mice with transverse aortic constriction (TAC), and compared them with those regulated at different stages of embryonic and postnatal development. In addition, exon-level analysis revealed widespread mRNA isoform changes during cardiac hypertrophy resulting from alternative usage of terminal or internal exons, some of which are also developmentally regulated and may be attributable to decreased expression of Fox-1 protein in cardiac hypertrophy. Genes with functions in certain pathways, such as cell adhesion and cell morphology, are more likely to be regulated by alternative splicing. Moreover, we found 3'UTRs of mRNAs were generally shortened through alternative cleavage and polyadenylation in hypertrophy, and microRNA target genes were generally de-repressed, suggesting coordinated mechanisms to increase mRNA stability and protein production during hypertrophy. Taken together, our results comprehensively delineated gene and mRNA isoform regulation events in cardiac hypertrophy and revealed their relations to those in development, and suggested that modulation of mRNA isoform expression plays an importance role in heart remodeling under pressure overload.  相似文献   

18.
Summary During heart development, cell hyperplasia and hypertrophy are the main mechanisms by which cardiac mass grows. Both these processes along with programmed cell death lead to complete growth and function. In addition, since the establishment of cardiac function depends on the relationship between oxygen supply and demand, we investigated some of the molecular mechanisms at the basis of rat myocardial cell response to hypoxic stress at different times of neonatal life. In particular, the role played by hypertrophic and survival factors like NF-kB and IAP-1 (Inhibiting Apoptosis Protein) and by death factors ASK-1 (Apoptosis Signal Regulating Kinase), JNK/SAPK (Jun-N-Terminal-Kinase/Stress-Activated Protein Kinase) pathways in regulating caspase-3 expression and activity has been evaluated by immunohistochemical and Western blotting analyses, respectively. Level of phosphorylation of IkB and IAP-1 expression were substantial in 8-day-old hypoxic hearts, suggesting the persistence of NF-kB driven hypertrophic signal along with a rescue attempt against hypoxic stress. In contrast, ASK-1 mediated JNK/SAPK activation, regulating Bcl2 levels, allows Bax homodimerization and caspase-3 activation in the same experimental conditions. Thus, a regulation carried out by NF-kB and JNK/SAPK pathways on caspase-3 activation at day 8 of neonatal life can be suggested as the main factor for the heart adaptive response to hypoxia.  相似文献   

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