血管外膜在低氧性血管重塑中的作用

血管外膜作为调节血管功能关键因子的生成、储存和释放的重要部位,在某些条件下被认为可能是血管壁的损伤感受组织。外膜细胞通常首先响应血管应激或损伤,进而影响血管壁的结构和功能。越来越多的证据表明,在低氧及相关的肺动脉高压、动脉粥样硬化等疾病引起的血管重塑过程中外膜的改变是最早、最突出的。成纤维细胞在血管对局部微环境改变的适应调节方面发挥了重要的作用。本文重点就血管外膜在低氧诱导血管重塑中的作用及其可能的分子机制进行综述。     

骨桥蛋白增强自发性高血压大鼠血管外膜成纤维细胞的迁移活性

血管外膜成纤维细胞迁移参与形成新生内膜是一些血管疾病的共同发病过程。研究高血压动物模型的外膜成纤维细胞是否与对照组不同将有利于阐述高血压血管重塑的机制。本实验比较自发性高血压大鼠(spontaneously hy-pertensive rats,SHR)与正常对照大鼠(Wistar-Kyoto rats,WKY)的血管外膜成纤维细胞在体外培养条件下迁移能力的差别,并对其机制进行了探讨。采用大鼠胸主动脉的培养血管外膜成纤维细胞,用Transwell技术测定培养细胞的迁移能力。用实时定量PCR技术检测mRNA表达。结果表明,在血清和bFGF趋化作用下,SHR培养血管外膜成纤维细胞的迁移活性显著强于WKY(每个视野平均迁移细胞数目,血清:35.20±5.26 vs 22.2±3.27,P<0.05;bFGF:30.23±4.54vs 19.20±4.47,P<0.05)。进一步研究发现,SHR培养血管外膜成纤维细胞中的骨桥蛋白(osteopontin,OPN)mRNA水平显著高于WKY(1863.23±43.91 vs 326.24±68.29,P<0.01)。反义OPN(100 μmol/L)对血清诱导的SHR血管外膜成纤维细胞迁移有抑制作用(每个视野平均迁移细胞数目 38.60±5.98 vs 26.61±3.84,P<0.05)。而正义及错配义OPN组均无此效应。反义OPN对SHR细胞迁移的抑制作用呈浓度依赖性。上述结果证实SHR培养血管外膜成纤维细胞的迁移能力强于WKY,OPN在细胞迁移中     

血管损伤的新靶点：干扰素调节因子

内膜增生是血管损伤后动脉重塑过程中普遍存在的现象。血管平滑肌细胞（vascular smooth muscle cells,VSMCs）的增殖、迁移、表型转换是血管损伤性疾病高血压、动脉粥样硬化、血管成形术后再狭窄等的共同病理生理学过程。干扰素调节因子（interferon regulatory factors,IRFs）是一类能对干扰素基因表达起到免疫调节作用的转录因子。近来研究发现,其在血管损伤病理过程具有调节作用,其中IRF1与细胞生长、分化和损伤密切相关,IRF3与IRF7可以抑制新生内膜的形成,而IRF8和IRF9则促进VSMCs增殖、迁移及血管内膜增生。本文重点介绍了IRFs的结构特征、信号途径及在血管重塑过程中作为新型调控因子的功能。     

整联蛋白调控血管新生内膜增生的研究进展

血管新生内膜增生是支架植入术、动静脉瘘术等血管手术以及动脉粥样硬化、高血压等心血管疾病的生理特征。整联蛋白介导的细胞黏附在新生内膜增生过程中起着重要作用。该文概述了整联蛋白在此过程中对白细胞黏附、平滑肌细胞迁移增殖、再内皮化的调控及目前用于研究新生内膜的相关动物模型。了解整联蛋白调节血管新生内膜增生的分子机制,为临床上防治新生内膜增生、解决术后血管再狭窄等相关研究提供参考。     

新型金属蛋白酶ADAMTS-7促进体内和体外血管平滑肌细胞增殖

血管平滑肌细胞增殖和迁移对动脉粥样硬化和血管成型术后再狭窄的发生具有重要作用.本课题组之前的研究发现,含Ⅰ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶ADAMTS-7能够通过调节血管平滑肌细胞迁移直接促进新生内膜的形成.然而ADAMTS-7是否影响血管平滑肌细胞增殖尚不清楚.本研究发现,腔内给予腺病毒造成在体ADAMTS-7过表达能够明显促进大鼠血管损伤7天后新生内膜的形成.PCNA阳性细胞比例在过表达ADAMTS-7的血管内膜和中膜中明显增多.此外,利用血管外膜涂抹小干扰RNA的技术沉默ADAMTS-7体内表达.结果表明,与对照组相比,敲低ADAMTS-7能够明显抑制内膜增厚和内膜平滑肌细胞增殖,但是并不影响中膜细胞.3H掺入实验结果表明,过表达ADAMTS-7能够明显促进体外培养的原代血管平滑肌细胞增殖,基因沉默则抑制其增殖.综上所述,新型金属蛋白酶ADAMTS-7能够在体内和体外促进血管平滑肌细胞增殖.本研究结果提示,ADAMTS-7可能成为防治动脉粥样硬化和血管成型术后的再狭窄的新作用靶点.     

Myocardin在血管平滑肌细胞表型转化中的作用

近年来大量的实验研究表明,血管平滑肌细胞(VSMCs)的增殖和迁移是各种血管疾病,包括动脉粥样硬化斑块形成、高血压、血管成形术后再狭窄等的病理基础。而血管平滑肌细胞的表型转化在其增殖和迁移中发挥着重要的作用。心肌素(myocardin)是迄今为止发现的最关键的促血管平滑肌细胞分化的转录因子,能有效激活平滑肌细胞(SMCs)的分化程序。近年来,人们对心肌素在平滑肌细胞表型转化过程中的功能进行了深入研究。现对血管平滑肌细胞的表型转化以及心肌素在血管平滑肌转化中的作用作一综述。     

碱性成纤维细胞生长因子研究进展

碱性成纤维细胞生长因子是细胞生长和分化的重要调节因子,具有促血管生成、细胞增殖、细胞趋化、细胞迁移等活性,在细胞分化和机体发育过程中发挥重要作用。碱性成纤维细胞生长因子通过与细胞膜表面的特异性配体结合,进而引发细胞内的一系列级联反应,从而产生各种生物学效应。本文对碱性成纤维细胞生长因子的生物学基础、信号转导、生物学功能以及临床应用研究进展作一综述。     

对血小板认识的进展

本文简要地描述血小板的超微结构;阐述血小板的粘附、聚集;血小板对血管活性胺等物质的吸收、贮存和释放;血小板对颗粒性物质的吞噬作用等多种细胞反应及其生物学意义。着重介绍血小板参与止血功能和血栓形成,维持血管内皮完整性、创伤愈合、动脉粥样硬化、炎症以及移植排斥等重要的生理和病理过程,从而说明血小板是一种多功能细胞。     

微粒在动脉粥样硬化形成及凝血异常中的作用

微粒是血管内皮细胞、组织细胞或血细胞激活或凋亡时形成的亚微型囊泡。动脉粥样硬化时血浆及粥样斑块中富含多种细胞来源的微粒,不仅促进斑块的发生发展并且在动脉粥样硬化凝血异常中起重要作用,可增进血管内皮细胞和白细胞间的相互作用,使单核细胞粘附于内皮细胞,从而迁移到斑块内,吞噬清除内膜下沉积的脂质。巨噬细胞吞噬脂质后凋亡形成大量微粒,抑制内皮细胞合成释放一氧化氮,加重内皮细胞损伤,促进斑块扩大。微粒表面富含的磷脂酰丝氨酸和组织因子是微粒促凝活性的主要来源,病灶处及循环中存在的大量微粒促进了动脉粥样硬化时凝血异常的发生。本文将就微粒在动脉粥样硬化形成及凝血异常中的作用做一综述。     

肿瘤相关成纤维细胞的形成及其在肿瘤发生与发展中的作用

肿瘤相关成纤维细胞(cancer-associated fibroblasts,CAFs)是肿瘤微环境的重要细胞组分.CAFs有多种细胞来源,包括常驻成纤维细胞、骨髓间充质干细胞和上皮细胞等.它们在肿瘤发展的各个阶段都发挥关键作用,能够促进肿瘤的增殖和迁移、促进肿瘤血管生成、调节肿瘤免疫和提高肿瘤耐药性等.因此,是肿瘤...     

Exendin-4, a glucagon-like peptide-1 receptor agonist, reduces intimal thickening after vascular injury

Glucagon-like peptide-1 is a hormone secreted by L cells of the small intestine and stimulates glucose-dependent insulin response. Glucagon-like peptide-1 receptor agonists such as exendin-4 are currently used in type 2 diabetes, and considered to have beneficial effects on the cardiovascular system. To further elucidate the effect of glucagon-like peptide-1 receptor agonists on cardiovascular diseases, we investigated the effects of exendin-4 on intimal thickening after endothelial injury. Under continuous infusion of exendin-4 at 24 nmol/kg/day, C57BL/6 mice were subjected to endothelial denudation injury of the femoral artery. Treatment of mice with exendin-4 reduced neointimal formation at 4 weeks after arterial injury without altering body weight or various metabolic parameters. In addition, in vitro studies of isolated murine, rat and human aortic vascular smooth muscle cells showed the expression of GLP-1 receptor. The addition of 10 nM exendin-4 to cultured smooth muscle cells significantly reduced their proliferation induced by platelet-derived growth factor. Our results suggested that exendin-4 reduced intimal thickening after vascular injury at least in part by the suppression of platelet-derived growth factor-induced smooth muscle cells proliferation.     

Circulating endothelial cells, microparticles and progenitors: key players towards the definition of vascular competence

The balance between lesion and regeneration of the endothelium is critical for the maintenance of vessel integrity. Exposure to cardiovascular risk factors (CRF) alters the regulatory functions of the endothelium that progresses from a quiescent state to activation, apoptosis and death. In the last 10 years, identification of circulating endothelial cells (CEC) and endothelial-derived microparticles (EMP) in the circulation has raised considerable interest as non-invasive markers of vascular dysfunction. Indeed, these endothelial-derived biomarkers were associated with most of the CRFs, were indicative of a poor clinical outcome in atherothrombotic disorders and correlated with established parameters of endothelial dysfunction. CEC and EMP also behave as potential pathogenic vectors able to accelerate endothelial dysfunction and promote disease progression. The endothelial response to injury has been enlarged by the discovery of a powerful physiological repair process based on the recruitment of circulating endothelial progenitor cells (EPC) from the bone marrow. Recent studies indicate that reduction of EPC number and function by CRF plays a critical role in the progression of cardiovascular diseases. This EPC-mediated repair to injury response can be integrated into a clinical endothelial phenotype defining the 'vascular competence' of each individual. In the future, provided that standardization of available methodologies could be achieved, multimarker strategies combining CEC, EMP and EPC levels as integrative markers of 'vascular competence' may offer new perspectives to assess vascular risk and to monitor treatment efficacy.     

Endothelial dysfunction as a cellular mechanism for vascular failure

The regulation of vascular tone, vascular permeability, and thromboresistance is essential to maintain blood circulation and therefore tissue environments under physiological conditions. Atherogenic stimuli, including diabetes, dyslipidemia, and oxidative stress, induce vascular dysfunction, leading to atherosclerosis, which is a key pathological basis for cardiovascular diseases such as ischemic heart disease and stroke. We have proposed a novel concept termed "vascular failure" to comprehensively recognize the vascular dysfunction that contributes to the development of cardiovascular diseases. Vascular endothelial cells form the vascular endothelium as a monolayer that covers the vascular lumen and serves as an interface between circulating blood and immune cells. Endothelial cells regulate vascular function in collaboration with smooth muscle cells. Endothelial dysfunction under pathophysiological conditions contributes to the development of vascular dysfunction. Here, we address the barrier function and microtubule function of endothelial cells. Endothelial barrier function, mediated by cell-to-cell junctions between endothelial cells, is regulated by small GTPases and kinases. Microtubule function, regulated by the acetylation of tubulin, a component of the microtubules, is a target of atherogenic stimuli. The elucidation of the molecular mechanisms of endothelial dysfunction as a cellular mechanism for vascular failure could provide novel therapeutic targets of cardiovascular diseases.     

解偶联蛋白2在内皮损伤及血管重构中的作用研究进展

心脑血管疾病是全球最主要的致死性疾病。活性氧(Reactive oxygen species,ROS)产生增多诱发血管内皮细胞损伤、平滑肌细胞迁移、增殖,是导致血管功能障碍、血管重构发生的重要机制。因此,氧化应激被认为是心脑血管疾病发生、发展的关键环节。但通过补充外源性抗氧化剂防治心脑血管疾病一直存在较大争议。机体可通过自身防御体系拮抗氧化应激,维持氧化-还原状态,如通过调控线粒体解偶联蛋白2(Uncoupling protein 2,UCP2)调节ROS生成,改善血管功能障碍及血管重构。本文就UCP2在内皮损伤及血管重构中的作用及机制展开综述,为深入探索这一潜在的防治心脑血管疾病的靶点提供信息。     

Chronic administration of NMU into the paraventricular nucleus stimulates the HPA axis but does not influence food intake or body weight

C-reactive protein (CRP), a predictor of future cardiovascular diseases, has been reported to damage the vascular wall by inducing endothelial dysfunction and inflammation. This proatherogenic CRP was speculated to have a role in attenuating angiogenic functions of human endothelial progenitor cells (EPCs), possibly impairing vascular regeneration and increasing cardiovascular vulnerability to ischemic injury. Herein, we investigated the direct effect of CRP on angiogenic activity and gene expression in human EPCs. Incubation of EPCs with human recombinant CRP significantly inhibited EPC migration in response to vascular endothelial growth factor, possibly by decreasing the expression of endothelial nitric oxide synthase and subsequent nitric oxide production. In addition, CRP-treated EPCs showed the reduced adhesiveness onto an endothelial cell monolayer. When assayed for the gene expression of arteriogenic chemo-cytokines, CRP substantially decreased their expression levels in EPC, in part due to the upregulation of suppressors of cytokine signaling proteins. These results suggest that CRP directly attenuates the angiogenic and possibly arteriogenic functions of EPCs. This CRP-induced EPC dysfunction may impair the vascular regenerative capacity of EPCs, thereby leading to increased risk of cardiovascular diseases.     

内皮祖细胞在炎症损伤修复中的作用和机制

内皮祖细胞（endothelial progenitor cells,EPCs）是出生后,可以在机体内分化为成熟内皮细胞的一种前体细胞,主要来源于骨髓。多种伴有血管内皮细胞损伤的疾病都可引起外周血EPCs数量变化。有研究显示EPCs参与炎性损伤修复,并且外周血EPCs数量与血管内皮损伤程度和疾病预后存在一定的相关关系。EPCs。通过动员、迁移、归巢和分化等步骤修复内皮。炎症反应中受损组织释放的基质细胞衍生因子、血管内皮生长因子可与EPCs相应的受体结合,通过内皮型一氧化氮合酶、基质金属蛋白酶9等途径调节内皮修复过程,这是EPCs分化为内皮细胞过程的主要调控机制。此外,EPCs还可通过旁分泌机制促进相邻的内皮细胞增殖分化。目前,EPCs在炎症领域仅用于内皮炎性损伤和疾病预后评估,但是EPCs在心血管疾病和组织工程领域应用研究的成功,为EPCs在炎症反应的诊断和治疗提供了新的思路。     

Mechanisms of lead-induced hypertension and cardiovascular disease

Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic illnesses. Population studies have demonstrated a link between lead exposure and subsequent development of hypertension (HTN) and cardiovascular disease. In vivo and in vitro studies have shown that chronic lead exposure causes HTN and cardiovascular disease by promoting oxidative stress, limiting nitric oxide availability, impairing nitric oxide signaling, augmenting adrenergic activity, increasing endothelin production, altering the renin-angiotensin system, raising vasoconstrictor prostaglandins, lowering vasodilator prostaglandins, promoting inflammation, disturbing vascular smooth muscle Ca(2+) signaling, diminishing endothelium-dependent vasorelaxation, and modifying the vascular response to vasoactive agonists. Moreover, lead has been shown to cause endothelial injury, impede endothelial repair, inhibit angiogenesis, reduce endothelial cell growth, suppress proteoglycan production, stimulate vascular smooth muscle cell proliferation and phenotypic transformation, reduce tissue plasminogen activator, and raise plasminogen activator inhibitor-1 production. Via these and other actions, lead exposure causes HTN and promotes arteriosclerosis, atherosclerosis, thrombosis, and cardiovascular disease. In conclusion, studies performed in experimental animals, isolated tissues, and cultured cells have provided compelling evidence that chronic exposure to low levels of lead can cause HTN, endothelial injury/dysfunction, arteriosclerosis, and cardiovascular disease. More importantly, these studies have elucidated the cellular and molecular mechanisms of lead's action on cardiovascular/renal systems, a task that is impossible to accomplish using clinical and epidemiological investigations alone.     

Athero- and thrombogenic actions of lysophosphatidic acid and sphingosine-1-phosphate

Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are potent bioactive phospholipids with specific and multiple effects on blood cells and cells of the vessel wall. Released by activated platelets, LPA and S1P mediate physiological wound healing processes such as vascular repair. Evidence is accumulating that these lipid mediators can, however, under certain conditions become athero- and thrombogenic molecules that might aggravate cardiovascular disease. For example, LPA present in minimally modified LDL and within the intima of atherosclerotic lesions may play a role in the early phase of atherosclerosis by inducing barrier dysfunction and increased monocyte adhesion of the endothelium, as well as in the late phase by triggering platelet activation and intra-arterial thrombus formation upon rupture of the atherosclerotic plaque. Moreover, LPA and S1P, by stimulating the proliferation of fibroblasts and by enhancing the survival of inflammatory cells are likely to play a central role in the excessive fibroproliferative and inflammatory response to vascular injury that characterizes the progression of atherosclerosis. Furthermore, LPA can cause the phenotypic dedifferentiation of medial vascular smooth muscle cells, and S1P is able to stimulate the migration and proliferation of intimal vascular smooth muscle cells; both processes ultimately lead to the formation of the neointima. Most importantly, as LPA and S1P bind to and activate multiple G-protein receptors, it emerges that the beneficial or harmful action of LPA and S1P are critically dependent on the expression profile of their receptor subtypes and their coupling to different signal transduction pathways in the target cells. By targeting specific subtypes of LPA and S1P receptors in selective cells of the vascular wall and blood, new strategies for the prevention and therapy of cardiovascular diseases can be envisioned.     

Oxidative stress in patients with cardiovascular disease and chronic renal failure

Abstract

Oxidative response regulates many physiological response in human health, but if not properly regulated it could also lead to a number of deleterious effects. The importance of oxidative stress injury depends on the molecular target, the severity of the stress, and the mechanism by which the oxidative stress is imposed: it has been implicated in several diseases including cancer, neurodegenerative diseases, malaria, rheumatoid arthritis and cardiovascular and kidney disease. Most of the common diseases, such as hypertension, atherosclerosis, heart failure, and renal dysfunction, are associated with vascular functional and structural alterations including endothelial dysfunction, altered contractility, and vascular remodeling. Common to these processes is increased bioavailability of reactive oxygen species (ROS), decreased nitric oxide (NO) levels, and reduced antioxidant capacity. Oxidative processes are up-regulated also in patients with chronic renal failure (CRF) and seem to be a cause of elevated risk of morbidity and mortality in these patients.

In this review, we highlight the role of oxidative stress in cardiovascular and renal disease.