血管平滑肌细胞表型转换对动脉粥样硬化的作用研究进展

在动脉粥样硬化的进程中,血管中膜平滑肌细胞发生表型转换、迁移、增殖,进入血管内膜,参与动脉粥样硬化斑块纤维帽及新生血管的生成。本文就当前关于血管平滑肌细胞表型转换对动脉粥样硬化作用的研究进展作一综述。     

心肌素抑制血管平滑肌细胞表型转换改善动脉粥样硬化

动脉粥样硬化(As)是一种涉及多种细胞并由多种因素诱导的慢性疾病,血管平滑肌细胞(VSMC)的增殖、迁移对As的发生和发展有着不可忽视的影响,包括促进斑块的生成及诱发斑块的不稳定等。VSMC由收缩表型向合成表型转换是其增殖和迁移的基础,维持VSMC的收缩表型,抑制其合成表型的形成有助于抑制其异常增殖和As斑块的形成。心肌素作为VSMC收缩标志基因的关键转录因子,能与血清反应因子结合来激活VSMC收缩标志基因的表达。多种功能因子,如雌激素受体α、组蛋白修饰、DNA甲基化和microRNA等,都可以与心肌素联合作用调节血管的功能并抑制VSMC的表型转换;多种作用途径,例如转化生长因子β1、血小板衍生生长因子BB等信号通路,可增加心肌素表达,抑制VSMC的增殖和迁移。因此,心肌素在As发展过程中有着至关重要的保护作用。调控心肌素影响VSMC的表型转换可能成为未来治疗As乃至心血管疾病的新策略。     

The good smooth muscle cells in atherosclerosis

The formation of a fibrous cap made up of intimal smooth muscle cells and connective tissue is part of an attempt by the vessel wall to encapsulate the toxic products accumulating in the necrotic core of atherosclerotic lesions, and should be viewed as a beneficial healing response. In this review, we discuss the development of the intima and the potential origins of the intimal smooth muscle cell with a focus on the unique properties of these cells. We further discuss the role of intimal smooth muscle cells in plaque rupture and in wound healing, and the relationship of wound healing to the loss of lumen that occurs with development of advanced atherosclerotic lesions.     

Progerin induces a phenotypic switch in vascular smooth muscle cells and triggers replication stress and an aging-associated secretory signature

GeroScience - Hutchinson-Gilford progeria syndrome is a premature aging disease caused by LMNA gene mutation and the production of a truncated prelamin A protein “progerin” that elicits...     

血管平滑肌细胞表型转化与血管钙化

血管钙化是一种由细胞所介导、主动的生物矿化过程,可增加心血管疾病的患病率和死亡率,并严重危害人类的健康和生活。越来越多的研究证实血管平滑肌细胞(Vascular smooth muscle cell,VSMC)及表型转化（phenotypic switching）在血管钙化的发生发展中具有重要作用。本文将阐述VSMC的表型转化,向骨/软骨化表型转化不同时期的标志蛋白分子,并探讨其表型转化的调控因素,进而深入认识血管钙化的发病过程。     

Src在氧化型低密度脂蛋白诱导平滑肌细胞表型转化中的作用

目的:探究Src对氧化型低密度脂蛋白(oxLDL)诱导血管平滑肌细胞表型转化的调控作用。方法:体外培养小鼠原代平滑肌细胞,以不同浓度的oxLDL刺激血管原代平滑肌细胞,检测平滑肌细胞表型分子平滑肌细胞表型肌球蛋白重链11(MYH11)、巨噬细胞表型CD68的表达变化,以及Src的激活情况。通过小干扰RNA(siRNA)抑制Src蛋白表达,Src特异性抑制剂PP2抑制Src激活,观察Src对oxLDL诱导的平滑肌细胞表型转化的影响。结果:分别以0、12.5、25.0、50.0μg/mL oxLDL刺激血管平滑肌细胞后发现MYH11的mRNA及蛋白表达逐渐下降(P<0.05),CD68的mRNA及蛋白表达逐渐升高(P<0.05)。以不同浓度(12.5、25.0、50.0μg/mL)、不同时间(15、30、60 min)的oxLDL刺激平滑肌细胞后,发现Src活性逐渐升高(P<0.05)。敲减Src siRNA或以PP2抑制Src蛋白活性后,oxLDL诱导的平滑肌细胞向巨噬细胞转化的分子表型的表达水平受到抑制。结论:oxLDL可以通过提高Src活性,进而诱导平滑肌细胞表型改变。     

Aging, smooth muscle cells and vascular pathobiology: implications for atherosclerosis

Epidemiological and autopsy studies suggest a close link between aging and the clinical manifestation of atherosclerosis. Several experiments show increased arterial susceptibility to atherogenetic stimuli in aged subjects. All together, these findings support the concept that aging represents an independent atherogenetic risk factor, intimately associated to other parietal, microenvironmental and systemic noxae. Smooth muscle cells (SMCs) represent the major arterial cell population. As aging occurs, SMCs progressively migrate from the tunica media and accumulate into the tunica intima. Myointimal thickening may represent the site where low-grade atherogenic stimuli cause early development and more severe lesion progression. Intimal SMC accumulation is characterized from a switch, from a differentiated to a synthetic phenotype, with reduced myocytic cytoskeletal markers and the expression of new proteins. Aging also associates to changes of SMC proliferative and apoptotic behavior and response to growth factors, such as transforming growth factor-beta1. The alteration of SMC properties represents a crucial event in the pathobiology of arterial wall, since it contributes to the vascular remodeling and decline of function with aging and favors the progression of atherosclerosis. Increased knowledge of biomolecular mechanisms regulating these events helps to develop new strategies aimed at contrasting the adverse effect of vascular aging.     

Micromanaging vascular smooth muscle cell differentiation and phenotypic modulation

The phenotype of vascular smooth muscle cells (VSMCs) is dynamically regulated in response to various stimuli. In a cellular process known as phenotype switching, VSMCs alternate between a contractile and synthetic phenotype state. Deregulation of phenotype switching is associated with vascular disorders such as atherosclerosis, restenosis after angioplasty, and pulmonary hypertension. An important role for microRNAs (miRNAs) in VSMC development and phenotype switching has recently been uncovered. Individual miRNAs are involved in promoting both contractile and synthetic VSMC phenotype. In this review, we summarize recent advances in the understanding of miRNA function in the regulation of VSMC phenotype regulation.     

Influence of atherosclerosis on vascular responsiveness in isolated rabbit vascular smooth muscle

Summary Coronary arteries and aortic rings were isolated from rabbits fed either a control diet or a high cholesterol (1 to 2%) diet for 8 to 11 weeks and studied for their vasoactive properties to a variety of vasoconstrictor and vasodilator agents. Perfused coronary arteries without intact endothelium constrict markedly to a thromboxane A₂ agonist (i.e., carbocyclic thromboxane A₂, CTA₂) and dilate markedly to iloprost, a prostacyclin analog. No differences occurred between the coronary arteries isolated from control or atherosclerotic rabbits. Additional studies were conducted on rabbit aortic vascular smooth muscle rings containing functionally intact endothelium and in rings denuded of their endothelium. Acetylcholine (20 to 2000 ng/ml) neither constricted nor dilated control aortic rings without endothelium, and markedly dilated aortic rings with intact endothelium in a concentration dependent manner. In atherosclerotic aortic rings, acetylcholine constricted preparations without endothelium, and dilated rings with endothelium to a much lesser extent than that observed in control rings. Similar reductions in responsiveness occurred with adenosine diphosphate (ADP), another endothelium-dependent vasodilator, but not with iloprost, a nonendothelium-dependent dilator. No differences were observed in constrictor responses to norepinephrine. Aortae from atherosclerotic rabbits produced less prostacyclin in response to arachidonic acid than control aortae. These data point to an important role of the endothelium in modulating the vascular response to vasodilators in atherosclerotic rabbit arterial vessels.This study was supported in part by Research Grant No. HL-25575 from the National Heart Lung and Blood Institute of the NIH.John A. Osborne is a Predoctoral Fellow of the Foerderer Foundation. Jian-zhong Sun is a WHO Postdoctoral Fellow.     

Smoothelin in vascular smooth muscle cells

Smoothelin-A and -B have only been found in fully differentiated contractile smooth muscle cells. They are increasingly used to monitor the smooth muscle cell differentiation process to a contractile or synthetic phenotype. Vascular-specific smoothelin-B is the first smooth muscle cell marker that disappears when vascular tissues are compromised, for example, in atherosclerosis or restenosis. Recently obtained data show that smoothelin deficiency results in a considerable loss of contractile potential and hence in impaired smooth muscle function and suggest that smoothelins are part of the contractile apparatus.     

Vascular smooth muscle cells and calcification in atherosclerosis

Vascular calcification is a prominent feature of atherosclerosis but the mechanisms underlying vascular calcification are still obscure. Since bone-associated proteins such as osteonectin, osteocalcin, and matrix Gla protein have been detected in calcified vascular tissues, calcification has been considered to be an organized, regulated process similar to mineralization in bone tissue. Vascular smooth muscle cells (VSMCs) are currently considered to be responsible for the formation of vascular calcifications. Apoptosis of VSMCs appears to be a key factor in this process, while other factors including cell-cell interactions (macrophages and VSMCs), lipids, and plasma inorganic phosphate levels modulate the calcification process. The focus of this review is on the role of VSMCs in the development of calcifications in atherosclerotic plaques.     

Angiotensin II-induced C-reactive protein generation: inflammatory role of vascular smooth muscle cells in atherosclerosis

BACKGROUND: As the major target of Angiotensin II (Ang II) in the vessel wall, vascular smooth muscle cells (VSMCs) are a tentative source to produce C-reactive protein (CRP). However, it is largely unknown if Ang II is capable of inducing CRP production in VSMCs. METHODS AND RESULTS: Ang II induced a concentration-dependent release of CRP in cultured rat VSMCs as measured by sandwich ELISA. Real-time PCR revealed that Ang II significantly upregulated CRP mRNA level in vitro. Ang II-induced CRP generation in aortic VSMCs was also investigated using double-labeled fluorescent immunohistochemistry and in situ hybridization in subchronic Ang II administration in rats. Losartan but not PD123319 markedly blocked the Ang II-induced CRP production in cultured VSMCs, suggesting that such effect was mediated via Ang II type 1 receptor. Further, Western blotting analysis showed that mitogen-activated protein kinase (MAPK) activation was obligatory in Ang II-induced CRP production, since specific MAPK inhibitor PD098059 almost abolished the action. CONCLUSIONS: We identified that Ang II is capable of inducing CRP generation in VSMCs, in which Ang II type 1 receptor followed by MAPK signal pathway is involved. It strengthened the role of Ang II-induced CRP production by VSMCs in the inflammatory process in atherosclerosis.     

血管平滑肌细胞表型转化的影响因素及相关血管疾病

<正>在不同的外界因素影响下,血管平滑肌细胞(vascular smooth.muscle cell.VSMCs)具有不同的细胞表型,具有极强的可塑性。正常血管中膜中的VSMCs是一种高分化的细胞.主要起维持血管形态以及收缩血管的作用,具有低增殖、低迁移、低蛋白分泌的特征;当发生动脉粥样硬化(atherosclerosis,AS)等血管病变时,VSMCs可以去分化成为未分化的细胞,细胞收缩性能下降,表现出高增殖、高迁移、高蛋白分泌等特征~([1])。以往把VSMCs细胞表型单纯的分为"收缩型"和"分泌型"~([2]),现在大量研究已证实,VSMCs可从已经分化的"收缩"表型向"分泌"表型方向去分化。在不同的外界因素作用下,VSMCs去分化的程度不同,可表现出各     

Galectin 1 is involved in vascular smooth muscle cell proliferation

OBJECTIVE: Smooth muscle cell (SMC) migration and proliferation are the key steps in the development of atherosclerosis and restenosis. Matricellular proteins have been implicated in cell adhesion, migration and proliferation. Here we investigated the role of the matricellular protein galectin-1 (Gal-1), a beta-galactoside-binding lectin, in SMC proliferation in atheroma and DNA synthesis in cell culture. METHODS: Protein expression was visualised by tissue section immunostaining. RNA expression was analysed using Northern blot analysis. DNA synthesis of human vascular SMCs was determined by 3H-thymidine incorporation. Recombinant glutathione S-transferase-galectin-1 fusion protein (Gal FP) binding to extracellular matrix (ECM) proteins was measured by ELISA. Gal-1 binding to cells and ECM was estimated using 125I-labelled Gal FP. RESULTS: Prominent Gal-1 staining coincided with SMC proliferation in human coronary endarterectomy samples in organoid culture. In cell culture, Gal-1 mRNA was upregulated in growing SMCs. Gal FP increased serum-induced DNA synthesis of human SMCs on plastic or endogenous ECM, but not of a rat PAC1 SM cell line. Also, Gal FP slightly increased SMC adhesion to ECM. SMCs exhibited a complex pattern of receptor-ligand interactions with Gal FP. The Gal-1 binding to SMCs was much stronger than to ECM, produced by these SMCs. We identified new ECM proteins: thrombospondin, vitronectin and osteopontin, which bound to Gal FP in a dose- and beta-galactoside-dependent manner in ELISA. CONCLUSIONS: Gal-1 binding to SMCs was stronger than to ECM, although ECM of atherosclerotic blood vessels contained additional ECM proteins which bound to Gal-1. Gal-1 was upregulated during SMC growth and Gal FP enhanced serum-induced DNA synthesis in SMCs. Overall, Gal-1 upregulation is likely to provide a reinforcement of serum-induced events during vascular injury.     

激活瞬时受体电位香草醛亚家族1改善平滑肌源性泡沫细胞形成机制研究

目的探讨瞬时受体电位香草醛亚家族1(TRPV1)在血管平滑肌细胞(VSMC)泡沫化过程中的作用及可能的机制。方法将野生型C57BL/6J雄性小鼠来源主动脉VSMC不加任何试剂刺激作为对照组,另将野生型C57BL/6J雄性小鼠和Toll样受体(TLR4)基因敲除(TLR4-/-)雄性小鼠来源主动脉VSMC使用氧化型低密度脂蛋白(oxLDL)80μg/ml刺激72h,建立oxLDL细胞模型,依次作为oxLDL组、辣椒素组(造模前预先用辣椒素50μmol/ml刺激VSMC 12h)和TLR4-/-组,每组5例。采用油红O染色观察VSMC内脂质聚积情况;检测VSMC内胆固醇、TRPV1、TLR4蛋白及炎性因子白细胞介素6(IL-6)和TNF-α表达。结果与对照组比较,oxLDL组VSMC泡沫化程度、胆固醇水平明显升高,TLR4及其介导的IL-6[(44.03±3.76)ng/L vs (25.64±4.84)ng/L]、TNF-α表达[(155.64±13.32)ng/L vs (89.86±9.18)ng/L]明显升高,差异有统计学意义(P<0.05),而TLR4-/-组和辣椒素组VSMC泡沫化程度、胆固醇水平、TLR4及其介导的IL-6、TNF-α表达与对照组比较,差异无统计学意义(P>0.05);与oxLDL组比较,辣椒素组VSMC中TRPV1蛋白表达明显上调,同时伴随VSMC泡沫化程度、胆固醇水平、TLR4及其介导的IL-6、TNF-α表达明显下调,差异有统计学意义(P<0.05)。结论激活TRPV1可通过干扰TLR4介导的炎性反应抑制VSMC泡沫化。