平滑肌细胞凋亡与血管疾病

平滑肌细胞凋亡参与了多种疾病的发生、发展过程。已有许多实验证明平滑肌细胞凋亡与动脉粥样硬化、血管再狭窄、高血压血管壁重塑、动脉瘤以及冠脉旁路移植术后移植血管的病变均有密切关系。     

动脉粥样硬化斑块中平滑肌细胞凋亡及凋亡相关基因的表达

为了揭示动脉粥样硬化发生发展过程中血管平滑肌细胞增殖与凋亡的关系及其调节机制，采用末端脱氧核糖核酸转移酶介导的dUTP缺口末端标记（TUNEL）染色法对家兔动脉粥样硬化斑块组织中平滑肌细胞的凋亡情况进行原位检测，并对原癌基因bcl-2、c-myc和P53在斑块组织中的表达活性进行North－ernblot分析。结果发现，在动脉粥样硬化斑块组织中有许多TUNEL染色阳性的平滑肌细胞，提示斑块组织中有平滑肌细胞凋亡发生：其斑块组织的DNA电泳图谱呈梯形状．符合细胞凋亡的特征性改变。Northern印迹分析表明，在动脉粥样硬化斑块组织中，原癌基因bck-2和P53的表达较正常组织增强，C－myc表达减低。提示这些基因的表达对动脉粥样硬化斑块组织中的平滑肌细胞凋亡起着重要的调节作用。     

血管平滑肌细胞凋亡与动脉粥样硬化及其中药防治

细胞凋亡在动脉粥样硬化形成的发病和治疗中具有重要意义。随着对动脉粥样硬化研究的深入，发现血管平滑肌细胞增生是其中重要因素。本文着重论述血管平滑肌细胞凋亡在动脉粥样硬化疾病中的作用，以及目前应用中药单体及中药复方调节血管平滑肌细胞凋亡的研究进展，同时对中医药防治动脉粥样硬化的前景进行展望。     

血管平滑肌细胞凋亡与动脉粥样硬化

细胞凋亡是细胞死亡的一种特殊形式,其过程受遗传基因及其他多种因素调控,最近研究表明,在动脉粥样硬化斑块中发现血管平滑细胞凋现象,本文着重介绍血管平滑肌细胞凋亡的相关基因,诱导因素,在动脉粥样硬化发生中的病理意义及未来研究展望。     

血管平滑肌细胞移行及表型转换的分子机制

在动脉粥样硬化发生、发展的不同阶段,血管平滑肌细胞表型转换具有重要且可能是不同的病理生理学意义。文章复习了近年动脉粥样硬化病损内膜中血管平滑肌细胞来源、血管平滑肌细胞表型转换的分子机制及鉴别不同平滑肌细胞表型的标志性分子,以期为深入理解动脉粥样硬化的发病机制和相关研究提供有益认识。     

细胞调亡与动脉粥样硬化

平滑肌细胞、内皮细胞和巨噬细胞与动脉粥样硬化的发生发展密切相关。在动脉粥样硬化斑块中，巨噬细胞、平滑肌细胞与内皮细胞都经历着凋亡与坏死，凋亡占主导地位，参与了粥样硬化的形成过程。氧自由基基、某些生长因子、一氧化氮、内毒素以及氧化型低密度脂蛋白等可诱导细胞凋亡。细胞凋亡具有复杂的分子调探机制，多种基因参与了凋亡的发生。     

细胞钙离子转运蛋白在动脉粥样硬化易损斑块形成中的作用

<正>作为冠心病的重要始动因素,动脉粥样硬化是以血管内皮损伤为基础的多种危险因素综合作用的结果,主要涉及血管重塑及易损斑块形成。血管平滑肌细胞(vascular smooth muscle cell VSMC)增殖与凋亡是决定动脉粥样硬化斑块发生、发展的重要环节。已知细胞内Ca2+参与了细胞增殖和     

血管平滑肌细胞对动脉粥样硬化形成的作用研究

动脉粥样硬化的形成是复杂且缓慢的过程。血管平滑肌细胞可分为合成型和收缩型,参与动脉粥样硬化的发生和发展。该文介绍血管平滑肌细胞外泌体、表型转化、离子通道、自噬以及细胞外高血糖状态对动脉粥样硬化形成的影响。     

花刺参粘多糖对血小板源生长因子BB诱导的大鼠血管平滑肌细胞增殖和凋亡的影响

目的观察花刺参粘多糖对血小板源生长因子BB诱导的大鼠血管平滑肌细胞增殖和凋亡的影响,以探讨花刺参粘多糖抗动脉粥样硬化、预防经皮腔内冠状动脉成形术后再狭窄的可能机制。方法组织块贴片法体外原代培养大鼠血管平滑肌细胞,细胞增殖采用四甲基偶氮唑盐、流式细胞细胞周期分析;流式细胞术、TUNEL法观察细胞凋亡。结果血小板源生长因子BB刺激后可促进血管平滑肌细胞增殖,抑制其凋亡;花刺参粘多糖则呈浓度依赖性地逆转此作用,光密度值由0.406±0.003减少到0.187±0.017(P<0.01),G0/G1期细胞比例由77.4%±5.7%增加到88.1%±5.3%(P<0.05),细胞凋亡率由8.6%±2.3%增加到22.6%±2.3%(P<0.05),凋亡细胞比例由2.7%±0.4%增加到10.1%±0.9%(P<0.01)。结论花刺参粘多糖可抑制血小板源生长因子BB诱导的血管平滑肌细胞增殖,促进其凋亡,这可能对延缓动脉粥样硬化的发生发展、防止经皮腔内冠状动脉成形术后再狭窄的发生起到一定作用。     

长链非编码RNA与动脉粥样硬化

最新研究证明长链非编码RNA(lncRNA)可调节脂质及糖代谢,调控血管壁功能,参与血管内皮细胞和平滑肌细胞的增殖、迁移、老化、凋亡以及血管炎症及免疫应答,从而影响动脉粥样硬化的发生发展。本文就lncRNA与动脉粥样硬化关系研究的进展作一综述。     

The effect of phenotype on mechanical stretch-induced vascular smooth muscle cell apoptosis

The present study evaluated mechanical stretch-induced apoptosis in swine vascular smooth muscle cells (VSMC) of different phenotypes. We demonstrated that differentiated VSMC express a greater level of Bcl-2-associated death factor (BAD) and have a significant cell loss when exposed to mechanical stretch (10% elongation, 1 Hz) for 24 h. We further demonstrated that apoptosis was significantly increased only in differentiated VSMC exposed to mechanical stretch. To test the hypothesis that the intracellular level of BAD in VSMC determines its response to mechanical stretch-induced apoptosis, we examined whether BAD expression was upregulated by mechanical stretch-induced apoptosis and was associated with the increase in the apoptosis level of differentiated VSMC. When exposed to mechanical stretch, the expression of BAD in differentiated VSMC was elevated at 1 h and remained at higher levels during the application of stretch (24 h). In contrast, Bcl-2 expression was suppressed during the application of stretch. Moreover, the proapoptotic function of BAD was inhibited by overexpression of Bcl-2 through transient transfection of VSMC with pCEP4-Bcl-2 or incubation of VSMC with vascular epithelial growth factor. These results suggest that mechanical stretch-induced VSMC apoptosis is phenotype dependent. The higher levels of apoptosis of differentiated VSMC upon mechanical stretch were, at least in part, dependent on their intrinsic level of BAD.     

粘着斑激酶在一氧化氮诱导血管平滑肌细胞凋亡中的作用

为研究一氧化氮对血管平滑肌细胞凋亡的影响及粘着斑激酶在一氧化氮诱导血管平滑肌细胞凋亡中的作用 ,应用脂多糖诱导血管平滑肌细胞合成内源性一氧化氮或加入可释放外源性一氧化氮的硝普钠 ,进行流式细胞术、DNA凝胶电泳及Northernblot和Westernblot分析。结果发现 ,无论是血管平滑肌细胞合成和释放的内源性一氧化氮还是体外补充的外源性一氧化氮均可显著诱导血管平滑肌细胞凋亡 ,且其诱导血管平滑肌细胞凋亡的强度与培养基中的NO-2 含量呈正相关 ;证实在一氧化氮诱导血管平滑肌细胞凋亡的同时 ,伴随Bcl 2和粘着斑激酶基因表达活性的明显下降。提示粘着斑激酶可能参与一氧化氮诱导血管平滑肌细胞凋亡的信号转导过程 ,一氧化氮诱导血管平滑肌细胞凋亡可能与抑制Bcl 2和粘着斑激酶基因表达有关     

氧化型低密度脂蛋白诱导大鼠血管平滑肌细胞凋亡

为研究氧化型低密度脂蛋白引起血管平滑肌细胞凋亡及其凋亡的机制,采用细胞形态学ＤＮＡ末标记法,流式细胞仪,Ｗｅｓｔｅｎ ｂｌｔｔｉｎｇ观察氧化型低密度脂蛋白诱导培养的大鼠血管平滑肌细胞凋亡。结果发现,在氧化型低密度脂蛋白作用下,血管平滑肌细胞阻滞在分裂期的中期,并发生凋亡,ＤＮＡ末端标记法和流式细胞仪检测发现氧化型低密度脂蛋白引起细胞凋亡明显高于天然低密度脂蛋白（前者是后者的１０倍）。电镜下凋亡细胞     

乐卡地平对老年大鼠血管平滑肌细胞增殖和凋亡的影响

目的探讨大鼠血管平滑肌细胞(VSMCs)发生衰老过程中,乐卡地平对细胞增殖和凋亡的影响和作用机制。方法取原代培养的4月龄和24月龄Wistar大鼠VSMCs分别为青年组、老年组,青年和老年大鼠加乐卡地平10μmol/L处理24 h分为青年实验组和老年实验组。采用免疫荧光染色、Western blot法、流式细胞分析仪和Real-time共聚焦等技术检测各组细胞核内p21蛋白结构含量的变化、细胞的增殖及凋亡指数和凋亡率。结果与青年组比较,青年实验组大鼠VSMCs分裂指数明显下降,相差13倍(P<0.05)。与青年组大鼠比较,乐卡地平对老年组大鼠的细胞内钙的抑制作用更强。与老年组比较,老年实验组大鼠细胞分裂指数和凋亡指数降低,差异有统计学意义[(2.08±0.22)%vs(0.7±0.06)%,P<0.05],凋亡率明显下降,差异有统计学意义[(16.1±2.04)%vs(2.3±0.88)%,P<0.01]。与青年组和老年组比较,老年实验组大鼠细胞核内p21蛋白随乐卡地平剂量增加而增强,蛋白结构发生变化,增殖性核抗原表达减少。结论乐卡地平通过改变p21蛋白的结构和含量表达,从而抑制增殖性核抗原表达,抑制VSMCs的增殖,降低老年大鼠VSMCs凋亡,减缓衰老。     

Mitofusin 2 triggers vascular smooth muscle cell apoptosis via mitochondrial death pathway

Previous studies have shown that mitofusin 2 (Mfn-2) (or hyperplasia suppressor gene [HSG]) inhibits vascular smooth muscle cell (VSMC) proliferation. Here, we demonstrate that Mfn-2 is a primary determinant of VSMC apoptosis. First, oxidative stress with H2O2, inhibition of protein kinase C with staurosporine, activation of protein kinase A with forskolin, and serum deprivation concurrently elevate Mfn-2 expression and induce VSMC apoptosis. Second, overexpression of Mfn-2 also triggers apoptosis of VSMCs in culture and in balloon-injured rat carotid arteries, thus contributing to Mfn-2-mediated prevention of neointima formation after angioplasty. Third, Mfn-2 silencing protects VSMCs against H2O2 or Mfn-2 overexpression-induced apoptosis, indicating that upregulation of Mfn-2 is necessary and sufficient for oxidative stress-mediated VSMC apoptosis. The Mfn-2 proapoptotic effect is independent of its role in mitochondrial fusion but mainly mediated by inhibition of Akt signaling and the resultant activation of the mitochondrial apoptotic pathway, as manifested by decreased Akt phosphorylation, increased mitochondrial Bax/Bcl-2 ratio, cytochrome c release, and activation of caspases-9 and caspase-3. Furthermore, Mfn-2-induced apoptosis was blocked by overexpression of an active phosphoinositide 3-kinase mutant or Bcl-xL or inhibition of caspase-9 but not caspases-8. Thus, in addition to its antiproliferative effects, Mfn-2 constitutes a primary determinant of VSMC apoptosis.     

Chronic apoptosis of vascular smooth muscle cells accelerates atherosclerosis and promotes calcification and medial degeneration

Vascular smooth muscle cell (VSMC) accumulation is implicated in plaque development. In contrast, VSMC apoptosis is implicated in plaque rupture, coagulation, vessel remodeling, medial atrophy, aneurysm formation, and calcification. Although VSMC apoptosis accompanies multiple pathologies, there is little proof of direct causality, particularly with the low levels of VSMC apoptosis seen in vivo. Using a mouse model of inducible VSMC-specific apoptosis, we demonstrate that low-level VSMC apoptosis during either atherogenesis or within established plaques of apolipoprotein (Apo)E(-/-) mice accelerates plaque growth by two-fold, associated with features of plaque vulnerability including a thin fibrous cap and expanded necrotic core. Chronic VSMC apoptosis induced development of calcified plaques in younger animals and promoted calcification within established plaques. In addition, VSMC apoptosis induced medial expansion, associated with increased elastic lamina breaks, and abnormal matrix deposition reminiscent of cystic medial necrosis in humans. VSMC apoptosis prevented outward remodeling associated with atherosclerosis resulting in marked vessel stenosis. We conclude that VSMC apoptosis is sufficient to accelerate atherosclerosis, promote plaque calcification and medial degeneration, prevent expansive remodeling, and promote stenosis in atherosclerosis.     

Rho-GDP dissociation inhibitor alpha downregulated by low shear stress promotes vascular smooth muscle cell migration and apoptosis: a proteomic analysis

AIMS: Low shear stress (LSS) plays a significant role in vascular remodelling during atherogenesis, which involves migration, proliferation, and apoptosis of vascular smooth muscle cells (VSMCs). The aim of the present study is to elucidate the molecular mechanisms by which LSS induces vascular remodelling. METHODS AND RESULTS: Using proteomic techniques, two-dimensional electrophoresis, and mass spectrometry, the protein profiles of Sprague-Dawley rat aorta cultured under two levels of shear stress, 5 and 15 dyn/cm(2), were determined. The results showed a significantly lower expression of protein-Rho-GDP dissociation inhibitor alpha (Rho-GDIalpha) in the LSS vessels. Rho-GDIalpha signalling mechanisms and effects on VSMC migration and apoptosis were then studied to understand the role of Rho-GDIalpha in the LSS-induced vascular remodelling. A decrease in Rho-GDIalpha expression by using target small interfering RNA (siRNA) transfection caused increases in the phosphorylation of Rac1 and Akt and enhancements of VSMC migration and apoptosis. Treatment with the PI3K/Akt-specific inhibitor wortmannin significantly decreased Akt phosphorylation, but had no effect on Rho-GDIalpha expression and Rac1 phosphorylation. Wortmannin was able to reverse the Rho-GDIalpha siRNA-induced enhancement of VSMC migration, but not VSMC apoptosis. CONCLUSION: The results indicate that the LSS-induced VSMC migration and apoptosis are mediated by a downregulation of Rho-GDIalpha. The effect of Rho-GDIalpha on VSMC migration is mediated by the PI3K/Akt pathway, but its effect on VSMC apoptosis is not.     

血管平滑肌细胞凋亡机制的研究进展

血管平滑肌细胞凋亡与很多心血管疾病的发生、发展密切相关,目前已经成为心血管疾病防治研究的热点。现对血管平滑肌细胞凋亡机制的研究现状进行了较为深入的探讨,从其诱导因素以及基因调控机制等角度综述了近年来国内外在这方面的研究进展。     

重组腺病毒AdCat对血管平滑肌细胞

目的探讨腺病毒载体介导的过氧化氢酶基因转染对体外培养的人血管平滑肌细胞增殖与凋亡的影响.方法用含过氧化氢酶基因的重组腺病毒(AdCat)转染人血管平滑肌细胞,采用Western blot 方法检测血管平滑肌细胞过氧化氢酶的表达,应用细胞计数方法观察血管平滑肌细胞的增殖活性,应用流式细胞术和Hoechst 33258 染色等方法对血管平滑肌细胞的凋亡进行研究.结果Western blot显示AdCat转染后血管平滑肌细胞过氧化氢酶表达明显增多;细胞计数显示AdCat组明显抑制细胞增殖,与阴性对照组、空白对照组相比差异有统计学意义(P<0.01);流式细胞术显示AdCat组与阴性对照组、空白对照组比较凋亡率明显增加(P<0.01).经Hoechst 33258染色后,AdCat组凋亡细胞明显多于空白对照组.结论重组腺病毒AdCat转染导致血管平滑肌细胞过氧化氢酶过度表达,抑制血管平滑肌细胞的增殖,促进血管平滑肌细胞的凋亡.     

过氧化氢酶过度表达对血管平滑肌细胞凋亡的影响

目的 探讨腺病毒戢体介导的过氧化氢酶基因转染对体外培养的人血管平滑肌细胞凋亡的影响。方法 用含过氧化氢酶基因的重组腺病毒转染人血管平滑肌细胞，采用Western blot方法检测血管平滑肌细胞过氧化氢酶的表达。应用流式细胞术、TUNEL法等方法检测血管平滑肌细胞的凋亡。结果 含过氧化氢酶基因的重组腺病毒转染后血管平滑肌细胞过氧化氢酶表达明显增多；流式细胞术显示含过氧化氢酶基因的重组腺病毒组与对照组比较凋亡率明显增加（P〈0．01）。经TUNEL分析显示，含过氧化氢酶基因的重组腺病毒组凋亡细胞明显多于对照组。两者之间有显著性差异（P〈0．001）。结论 腺病毒载体介导的过氧化氢酶基因转染导致过氧化氢酶过度表达。促进人血管平滑肌细胞的凋亡，这可能是防治经皮腔内冠状动脉血管成形术后再狭窄的一种新方法。