大鼠骨髓间充质干细胞条件培养液对心脏成纤维细胞胶原合成的影响

目的体外模拟机体缺血环境,研究骨髓间充质干细胞(MSCs)旁分泌对心脏成纤维细胞胶原合成的影响,为MSCs移植机制提供实验依据。方法分离培养SD大鼠的MSCs,换以无血清培养液同时缺氧处理不同时间,然后收集MSCs的条件培养液,以此条件培养液作为刺激因子孵育 SD大鼠的心脏成纤维细胞,用MTT和3H-脯氨酸掺入观察心脏成纤维细胞的增殖及胶原合成。结果用MSCs条件培养液培养心脏成纤维细胞,3H-脯氨酸掺入明显高于对照组,缺氧6 h组的3H-脯氨酸掺入高于对照组约100％,提示MSCs条件培养液刺激心脏成纤维细胞胶原合成增加;MTT结果无显著差异,提示:MSCs条件培养液没有影响心脏成纤维细胞的增殖。结论大鼠骨髓间充质干细胞的缺氧和无血清条件培养液能够通过旁分泌刺激心脏成纤维细胞自身合成胶原能力的增强,提示移植到缺血心肌缺血区的骨髓间充质干细胞可能通过旁分泌作用影响心脏成纤维细胞的胶原合成,从而参与损伤心肌的修复。     

肾素-血管紧张素-醛固酮系统与心肌间质纤维化

心肌间质纤维化发生于多种心血管疾病,引起心脏舒张功能减退,导致泵功能衰竭。目前,肾素-血管紧张素一醛固酮系统（RAAS）与心肌纤维化的关系已得到深入研究,本文拟在这方面作简要阐述。1心肌组织的正常结构与心肌间质纤维化心肌组织由细胞和间质构成。心脏中心肌细胞数不足心脏细胞总数的1／3,大多数细胞是间质细胞,主要是成纤维细胞,它能够合成胶原,可以重新进入细胞周期,进行有丝分裂⑴。细胞外间质决定着心脏的结构和功能,其主要的结构蛋白为Ⅰ型和Ⅲ型胶原,由纤维连接素将它们锚定于心肌细胞和成纤维细胞膜上。Ⅰ型胶原构…     

中医药抗心肌纤维化研究趋势的分析与探讨

心肌纤维化是指胶原浓度显著升高或胶原容积分数显著高于正常值。其主要的特征为成纤维细胞数目增多和心肌细胞外间质胶原过度沉积。心肌纤维化在多种心血管疾病中均存在,与心律失常、心功能障碍及心脏猝死密切相关。预防和逆转心肌纤维化已成为众多心血管疾病的主要治疗目标。     

心肌成纤维细胞在血管紧张素II致心脏间质纤维化中的作用

在心脏纤维化过程中 ,心肌成纤维细胞扮演着重要角色。血管紧张素 可增加心肌成纤维细胞合成 ,分泌整合素、骨桥素等粘附分子 ,从而诱导细胞外基质蛋白合成 ,促进间质纤维化     

原发性高血压患者血清Ⅲ型前胶原氨基端肽的检测价值

心肌间质胶原主要为I、Ⅲ型胶原[1]。成纤维细胞生成的Ⅲ型前胶原分泌入细胞外间隙后会被特异性的肽酶分解,释出一个氨基末端肽(PⅢNP)。因而PⅢNP可作为Ⅲ型胶原合成的指标[1,2]。本文观察原发性高血压(EH)患者血清PⅢNP浓度,同时测血管紧张素Ⅱ(AngⅡ)含量,并与舒张功能作相关比较,以探讨PⅢNP作为心脏纤维化血清指标的临床价值。     

胶原在心血管疾病作用的研究进展

心脏细胞外基质 (ECM)中主要为 、 型胶原( 型占 85 %、 型占 11% )及纤连蛋白等 ,它构成心脏三维结构 ,决定了心脏组织的伸展性和弹性。几十年研究结果发现 ECM并不是一个惰性系统 ,而处于动态的合成、降解过程 ,心血管胶原网的作用逐渐被认识。本文就胶原和高血压、心肌梗死及血管成形术等心血管疾病关系作一综述。1　胶原性状及功能1.1　胶原性状 :成纤维细胞首先合成 、 型前胶原 ,较大的前体含有羧基端 (C端 )和氨基端 (N端 )前肽。C端前肽含有非胶原氨基酸 ,呈球形 ,N端前肽含有短胶原氨基酸顺序 ,呈三维螺旋结构 ,分泌入细胞外…     

心肌成纤维细胞在血管紧张素Ⅱ致心脏间质纤维化中的作用

在心脏纤维化过程中，心肌成纤维细胞扮演着重要角色。血管紧张素Ⅱ可增加心肌成纤维细胞合成，分泌整合素、骨桥素等粘附分子，从而诱导细胞外基质蛋白合成，促进间质纤维化。     

血管紧张素Ⅱ和醛固酮对心脏成纤维细胞Ⅲ型胶原mRNA表达的影响

目的　研究肾素 血管紧张素 醛固酮系统 (RAAS)的效应激素血管紧张素Ⅱ (ANGⅡ )和醛固酮 (ALD)对培养的心脏成纤维细胞Ⅲ型胶原mRNA表达的影响。方法　用RT PCR的方法检测原代培养心脏成纤维细胞Ⅲ型胶原mR NA表达。结果　ANGⅡ (10 - 8mol L)和ALD(10 - 8mol L)分别能促进心脏成纤维细胞Ⅲ型胶原mRNA表达 ,其各自的受体拮抗剂可分别拮抗它们的作用。结论　ANGⅡ和ALD可直接促进Ⅲ型胶原在心肌间质沉积 ,在心室重塑的病理生理过程中扮演重要角色。应用ANGⅡ和ALD的受体拮抗剂可抑制心肌纤维化 ,预防心室重塑的发生。     

心肌间质细胞在心肌纤维化中的作用

在心肌纤维化的形成过程中,往往有一些间质效应细胞发挥着关键作用。这些细胞虽然不一定能直接合成和分泌胶原,但他们的激活,已成为胶质生成细胞的重要来源。涉及心肌胶原代谢调控的间质细胞主要有成纤维细胞、肌成纤维细胞、平滑肌细胞、内皮细胞、周细胞等。     

心脏胶原纤维增生及其影响因素

心脏是由心肌细胞和非心肌细胞构成 ,非心肌细胞约占细胞总数的三分之二 ,其中 90 %以上是合成分泌胶原的成纤维细胞 (FBC)。婴儿出生后心肌细胞即丧失增殖能力 ,而非心肌细胞仍然保持增殖的能力。尤其当心脏遭受各种损伤时 ,FBC大量增殖 ,细胞外间质蛋白过度聚集 ,胶原类型改变而导致的心脏胶原网络重构是心室重构的一个特征性改变 ,在各种心脏病病程中有重要意义 ,深入研究其形成机制及影响因素以采取有效的干预措施 ,无疑对改善预后、提高疗效大有裨益。现将有关方面内容综述如下 :1　心脏胶原的合成及降解胶原的合成是在FBC的粗面内…     

Long-acting calcium channel blocker benidipine suppresses expression of angiogenic growth factors and prevents cardiac remodelling in a Type II diabetic rat model

Aims/hypothesis: Calcium channel blockers, widely used for the treatment of hypertension and angina, could prevent cardiovascular complications in patients with diabetes. They can improve cardiac remodelling in animal models of a variety of cardiovascular diseases. Here, we examined the therapeutic effect of benidipine, a long-acting calcium channel blocker, on cardiac remodelling in Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats, a Type II (non-insulin-dependent) diabetes mellitus model. Methods: The methods for morphometric analysis included double staining for coronary capillaries, dye-binding staining for collagen content and Masson's trichrome staining for perivascular fibrosis. Immunohistochemical and in situ hybridization techniques were used for detecting protein and mRNA expressions for vascular endothelial growth factors (VEGF), basic fibroblast growth factors (bFGF) and TGF-β ₁, endothelial nitric oxide synthase (eNOS), and anti- and pro-apoptotic markers. Results: OLETF rats showed an increased coronary capillary density, a reduced venular capillary proportion, an increased cardiac collagen content and prominent cardiac perivascular fibrosis. In OLETF rat hearts, significant increases in vascular expressions for VEGF, bFGF and TGF-β ₁ were found. Furthermore, the apoptosis signalling pathways, involving eNOS and apoptotic markers, were markedly altered, and coronary endothelial cell apoptosis was lower. These alterations with the exception of eNOS expression were significantly blocked by benidipine treatment. Conclusion/interpretation: The suppressive effect of benidipine on overproduction of angiogenic growth factors could prevent cardiac angiogenesis and fibrosis, resulting in an improvement of cardiac remodelling in diabetes. As VEGF and bFGF potently block endothelial cell apoptosis execution, physiological apoptosis revived by benidipine treatment could also contribute to coronary vessel regression. [Diabetologia (2002) 45: 402–415] Received: 16 July 2001 and in revised form: 5 November 2001     

Control of apoptosis of cardiovascular fibroblasts: A novel drug target

Adequate control of survival or programmed cell death (apoptosis) of cardiovascular cells appears as an important drug target. While prevention of apoptotic death of cardiomyocytes has been assessed in detail, selective induction of apoptosis of vascular smooth muscle cells or fibroblasts could also be of relevance. Thus, induction of apoptosis of vascular smooth muscle cells by p65 NF-kappa B and Bcl-xL antisense oligonucleotides or p53 overexpression could be useful for limiting vascular lesions associated with restenosis. Although fibroblasts represent the majority of cardiac cells, few attempts were made to induce fibroblast apoptosis in disorders associated with excessive collagen deposition and fibrosis. It is hypothesized that early interference with fibroblast proliferation after myocardial infarction or inflammatory heart disease limits fibrosis which further impairs cardiac performance. A candidate approach could involve growth factor analogues which are known to induce fibroblast apoptosis when an incomplete growth stimulus persists.     

Characterising the myocardial interstitial space: the clinical relevance of non-invasive imaging

The myocardial interstitial or extracellular space exists as a complex and dynamic environment, vital for normal cardiac structure and function. The physiological pathways for normal control of collagen turnover, and the pathological development of fibrosis are beginning to be understood, as are their relationships to cardiac remodelling and adverse outcomes. Emerging non-invasive imaging techniques (echocardiography, cardiovascular magnetic resonance, positron emission tomography) may allow a clearer understanding and measurement of these processes in vivo. Preliminary results are exciting, spanning valvular and congenital heart disease, cardiomyopathy and rarer diseases such as amyloid. In this review, such developments and research directions are explored, including the rapid developments in cardiovascular magnetic resonance T1 mapping and its use with contrast to derive extracellular volume. The authors present a state-of-the-art assessment of the strengths and weaknesses of each modality, and distil a framework to equip the reader with an understanding of the technical issues useful for the interpretation of emerging clinical studies.     

Notch3 Ameliorates Cardiac Fibrosis After Myocardial Infarction by Inhibiting the TGF-β1/Smad3 Pathway

Notch3 and TGF-β1 signaling play a key role in the pathogenesis and progression of chronic cardiovascular disease. However, whether Notch3 protects against myocardial infarction (MI) and the underlying mechanisms remains unknown. C57BL/6 mice were randomized to be treated with Notch3 siRNA (siNotch3) or lentivirus carrying Notch3 cDNA (Notch3) before coronary artery ligation. Four weeks after constructing MI model, cardiac function and fibrosis were compared between groups. The cardiac fibroblast cells (CFs) were isolated from newborn C57BL/6 mice (1–3 days old) and transfected with lentivirus carrying Notch3 cDNA. TGF-β1 (5 ng/ml), a well-known pro-fibrotic factor, was administered 72 h after Notch3 cDNA administration in CFs. The related proteins of fibrosis such as a-smooth muscle actin (a-SMA), Type I collagen, metalloprotease (MMP)-9 and the tissue inhibitor of metalloproteinases (TIMP)-2 were examined by western blot analysis. Notch3 cDNA treatment attenuated cardiac damage and inhibited fibrosis in mice with MI. Meanwhile, Notch3 siRNA administration aggravated cardiac function damage and markedly enhanced cardiac fibrosis in mice with MI. Overexpression of Notch3 inhibited TGF-β1-induced fibroblast–myofibroblast transition of mouse cardiac fibroblast cells, as evidenced by down-regulating a-SMA and Type I collagen expression. Notch3 cDNA treatment also increased MMP-9 expression and decreased TIMP-2 expression in the TGF-β1-stimulated cells. This study indicates that Notch3 is an important protective factor for cardiac fibrosis in a MI model, and the protective effect of Notch3 is attributable to its action on TGF-β1/Smad3 signaling.     

Myofibrillar remodeling in cardiac hypertrophy, heart failure and cardiomyopathies

BACKGROUND: A wide variety of pathological conditions have been shown to result in cardiac remodelling and myocardial dysfunction. However, the mechanisms of transition from adaptive to maladaptive alterations, as well as those for changes in cardiac performance leading to heart failure, are poorly understood. OBSERVATIONS: Extensive studies have revealed a broad spectrum of progressive changes in subcellular structures and function, as well as in signal transduction and metabolism in the heart, among different cardiovascular disorders. The present review is focused on identifying the alterations in molecular and biochemical structure of myofibrils (myofibrillar remodelling) in hypertrophied and failing myocardium in different types of heart diseases. Numerous changes at the level of gene expression for both contractile and regulatory proteins have already been reported in failing hearts and heart diseases; these changes are potential precursors for heart failure such as cardiac hypertrophy and cardiomyopathies. Myofibrillar remodelling, as a consequence of proteolysis, oxidation, and phosphorylation of some functional groups in both contractile and regulatory proteins in hearts failing due to different etiologies, has also been described. CONCLUSIONS: Although myofibrillar remodelling appears to be associated with cardiac dysfunction, alterations in both contractile and regulatory proteins are dependent on the type and stage of heart disease.     

Novel insights into the role of cardiotrophin-1 in cardiovascular diseases

Cardiotrophin-1 (CT-1), a member of interleukin (IL)-6 family, was originally isolated for its ability to induce a hypertrophic response in neonatal cardiac myocytes. This cytokine mediates a pleiotropic set of growth and differentiation activities through a unique receptor system, consisting of IL-6 receptor (IL-6R) and a common signal transducer, the glycoprotein 130 (gp130). Both in humans and in mice, CT-1 mRNA has been detected in several tissues, such as liver tissue, adipose tissue, and tissues in the respiratory and nervous systems; in each of these tissues it performs different functions. Predominant actions of CT-1 are on the heart, where it is synthesized and where it provides first myocardial protection by promoting cell survival and proliferation, it carries on its haemodynamic effects and endocrine properties, and finally, it predisposes the heart to pathological conditions. The aim of this review is to describe the pathophysiological mechanisms through which CT-1 carries out its activities, especially on the heart, and its potential contribution as a disease marker in clinical cardiology. Recent studies have confirmed its active role in promoting structural changes typical of most common cardiovascular disease, such as hypertension, valve diseases, congestive heart failure, and coronary artery disease. In fact, CT-1 induces myocyte hypertrophy and collagen synthesis, thereby participating in the progression of ventricular remodelling, which results in cardiac muscle failure at the latest stage. CT-1 plasma levels are elevated in patients with hypertension and coronary artery diseases, and they are also correlated with the severity of valve diseases and heart failure. Therefore, CT-1 may represent a diagnostic, staging, and prognostic biomarker of cardiovascular diseases.     

MicroRNA and vascular remodelling in acute vascular injury and pulmonary vascular remodelling

Vascular remodelling is an integral pathological process central to a number of cardiovascular diseases. The complex interplay between distinct cell populations in the vessel wall following vascular injury leads to inflammation, cellular dysfunction, pro-growth signals in the smooth muscle cell (SMC) compartment, and the acquisition of a synthetic phenotype. Although the signals for vascular remodelling are diverse in different pathological contexts, SMC proliferation and migration are consistently observed. It is therefore critical to elucidate key mechanisms central to these processes. MicroRNAs (miRNAs) are small non-coding sequences of RNA that have the capacity to regulate many genes, pathways, and complex biological networks within cells, acting either alone or in concert with one another. In diseases such as cancer and cardiac disease, the role of miRNA in disease pathogenesis has been documented in detail. In contrast, despite a great deal of interest in miRNA, relatively few studies have directly assessed the role of miRNA in vascular remodelling. The potential for modulation of miRNA to achieve therapeutic benefits in this setting is attractive. Here, we focus on the role of miRNA in vascular inflammation and remodelling associated with acute vascular injury (vein graft disease, angioplasty restenosis, and in-stent restenosis) as well as in vascular remodelling associated with the development of pulmonary arterial hypertension.     

血管紧张素 II通过增加miR-21表达促进心脏成纤维细胞胶原合成

目的 探讨血管紧张素II（AngII）促进心脏成纤维细胞胶原合成的分子机制,初步分析miR-21在其中发挥的作用。方法 使用SD大鼠心脏组织分离培养原代成纤维细胞;分别使用0、0.1、0.2和0.4 μmol/L的AngII刺激细胞36 h,qRT-PCR检测胶原（Col1a1和Col3a1）和miR-21的表达变化;使用miR-21抑制物（miR-21 inhibitor）转染细胞,AngII刺激后,qRT-PCR检测Col1a1和Col3a1的表达。结果 镜下观察和标志物分子检测表明心脏成纤维细胞培养成功。在AngII刺激下,Col1a1、Col3a1和miR-21均呈剂量依赖性表达增加(P<0.05)。使用miR-21抑制物能显著降低Ang II刺激下Col1a1和Col3a1的表达升高(P<0.05)。结论 AngII能增加心脏成纤维细胞的胶原合成,其相关机制可能部分通过miR-21相关信号来介导。