B细胞性淋巴瘤因子-2及其BH4结构域参与的细胞凋亡与动脉粥样硬化疾病

正近年来,动脉粥样硬化疾病的发生率逐年升高,动脉粥样硬化易损斑块是引致急性冠状动脉综合征的主要原因。其发病涉及多种机制,包括炎症,氧化应激,脂质代谢紊乱等,其中血管内皮细胞、血管平滑肌细胞及血小板等多种细胞凋亡既是上述多种因素作用的结果,也是加速动脉粥样硬化易损斑块形成的主要原因,是动脉粥样硬化易损斑块的重     

易损血液与动脉粥样硬化症关系研究进展

研究表明动脉粥样硬化是在内皮损伤、脂质代谢异常、血流动力学损伤、遗传、感染、物理化学等损伤刺激下启动的,多种炎症因子、免疫机制及相关细胞因子网络交叉样作用于血管壁,动脉粥样硬化逐渐形成和发展同时伴随不稳定斑块的破裂、血栓形成,导致慢性和急性缺血或闭塞性临床事件。不论何种机制,血管壁动脉粥样硬化必须通过血液来介导和促进,易损血液包括血液的成分和状态异常,血液易损程度与动脉粥样硬化性临床事件正相关。     

单核细胞膜联蛋白A1表达水平与冠心病的研究进展

动脉粥样硬化（AS）是导致急性心脑血管事件的病理学基础之一。研究发现,导致冠心病急性心血管事件的主要原因是局部AS斑块破裂和血栓形成,后者取决于AS斑块的易损性,而易损斑块可出现斑块破裂和血栓形成,从而导致急性冠脉综合征（ACS）的发生。同时研究发现,炎症免疫机制、增殖凋亡机制、损伤应激机制以及生物力学机制参与了AS斑块的发生、发展过程。     

炎症与动脉粥样硬化关系研究进展

研究表明动脉粥样硬化是一种慢性炎症,在内皮损伤、脂质代谢异常、血流动力学损伤、遗传、感染、物理化学等损伤刺激下,多种炎症因子、免疫机制及相关细胞因子网络交叉样作用于血管壁,形成慢性炎症。炎症反应贯穿于动脉粥样硬化的启动、形成和发展以及不稳定斑块,众多的的炎症标志物为动脉粥样硬化的评估和临床预测提供一条重要途径。抗炎症治疗在动脉粥样硬化的防治中不断取得突破。     

骨保护素与动脉粥样硬化的研究进展

骨保护素是属于肿瘤坏死因子超家族成员之一的一种可溶性糖蛋白,近来研究表明骨保护素不仅参与骨代谢,同时与体内能量和糖脂代谢关系密切,且其与动脉粥样硬化及糖脂代谢异常相关的心血管病变、微血管病变联系紧密。骨保护素可能通过调节糖脂代谢和内皮功能、抑制血管钙化、抑制炎症、抑制凋亡等机制参与动脉粥样硬化发生发展过程。     

C反应蛋白与动脉粥样硬化的新进展

动脉粥样硬化是一种由于血管内皮功能紊乱或受损而引发的慢性炎症性疾病.目前认为,Ross[1]的"炎症假说"是动脉粥样硬化(atherosclerosis,AS)的主要发病机制,临床上可表现为脂质沉积、炎症细胞浸润、泡沫细胞形成、斑块的纤维化及钙化等[2].     

NLRP3炎症小体介导氧化三甲胺加速动脉粥样硬化的新进展

动脉粥样硬化是一种伴有脂质代谢紊乱的慢性炎症反应。NOD样受体蛋白3(NLRP3)炎症小体作为一种多蛋白组成的炎症复合物,与细胞活性、血管炎症、斑块进展密切相关。氧化三甲胺作为肠道菌群主要代谢产物,能启动NLRP3炎症小体的激活,参与粥样硬化斑块形成和斑块破裂的病理学过程。现就氧化三甲胺与NLRP3炎症小体在动脉粥样硬化中的作用进行综述,旨在为动脉粥样硬化的机制研究和临床防治提供新视角。     

有氧运动减轻动脉粥样硬化斑块形成的研究进展

有氧运动的抗炎、调整血脂代谢、平衡免疫等作用可以稳定和减轻动脉粥样硬化斑块,成为救治急性冠脉综合症(ACS)的重要措施。有氧运动可降低ACS的风险,防范ACS的发生,它的影响机制亟需探讨和研究。本研究综述了有氧运动减轻动脉粥样硬化斑块形成中的可能机制、作用及其进展。     

血管新生对动脉粥样硬化斑块稳定性影响的研究进展

斑块内血管新生由低氧和炎症等因素诱导形成,在动脉粥样硬化斑块的发生发展中发挥了重要作用。一方面通过加剧炎症反应和诱发斑块内出血,影响斑块的稳定性,从而诱发死亡率极高的急性冠状动脉综合征;另一方面可缓解斑块内低氧状态,减少细胞坏死,为斑块内有害物质的移出提供通道。抗血管生成治疗虽已投入临床应用,但在动脉粥样硬化方面进展甚小。本文就斑块内新生血管形成发生机制、血管新生对动脉粥样硬化斑块稳定性的影响及其相关临床应用进展作一综述。     

动脉粥样硬化钙化的研究进展

血管钙化是异位钙化一种,分为中膜钙化和内膜钙化,中膜钙化相关的疾病有肾病、糖尿病等,而内膜钙化主要与动脉粥样硬化有关。血管钙化亦是心血管疾病的一危险因素,是慢性炎症反应的重要指标,动脉粥样硬化钙化即内膜钙化则充分体现了该作用。它的程度直接与粥样硬化疾病的斑块负荷有关。因此受到研究者广泛的关注,现就动脉粥样硬化钙化发生机制、相关因素及实验模型等方面做一综述。     

Advanced glycation end product cross-linking: pathophysiologic role and therapeutic target in cardiovascular disease

Advanced glycation end products (AGEs) form by a nonenzymatic reaction between reducing sugars and biological proteins. These stable compounds accumulate slowly throughout the life span and contribute to structural and physiologic changes in the cardiovascular system such as increased vascular and myocardial stiffness, endothelial dysfunction, altered vascular injury responses, and atherosclerotic plaque formation. Mechanisms underlying these alterations include AGE cross-linking of collagen and AGE interactions with circulating proteins and AGE receptors. The clinical manifestations of AGE accrual-isolated systolic hypertension, endothelial and diastolic dysfunction, and atherosclerosis-underscore their role in increased cardiovascular risk associated with aging as well as diabetes and hypertension, conditions that enhance AGE formation. New pharmacologic agents that prevent AGE, break cross-links, or block AGE receptors reduce vascular and myocardial stiffness, inhibit atherosclerotic plaque formation, and improve endothelial function. These agents promise to reduce the risk of isolated systolic hypertension, diastolic dysfunction, and diabetes, and thus, heart failure.     

Diabetes and advanced glycation endproducts

Bio-reactive advanced glycation endproducts (AGE) alter the structure and function of molecules in biological systems and increase oxidative stress. These adverse effects of both exogenous and endogenously derived AGE have been implicated in the pathogenesis of diabetic complications and changes associated with ageing including atherosclerosis, renal, eye and neurological disease. Specific AGE receptors and nonreceptor mechanisms contribute to these processes but also assist in the removal and degradation of AGE. The final disposal of AGE depends on renal clearance. Promising pharmacologic strategies to prevent AGE formation, reduce AGE toxicity, and/or inactivate AGE are under investigation.     

斑块侵蚀发病机制的最新研究进展

斑块侵蚀是导致急性冠脉综合征的另一重要原因,目前针对斑块侵蚀病变的发生和发展过程尚不清楚。血流紊乱会激活内皮细胞Toll样受体2,介导内皮细胞凋亡、剥脱,作为斑块侵蚀病变发生的启动因素。透明质酸和多功能蛋白聚糖代谢障碍、细胞外基质发生重构,在斑块侵蚀病变进程中发挥核心作用。中性粒细胞形成胞外诱捕网,释放细胞活性成分,进一步损伤内皮细胞,促进血栓形成。现主要从以上三方面对斑块侵蚀病变形成的可能机制及假说进行综述。     

Substrates modified by advanced glycation end-products cause dysfunction and death in retinal pericytes by reducing survival signals mediated by platelet-derived growth factor

Aims/hypothesis Premature death of retinal pericytes is a pathophysiological hallmark of diabetic retinopathy. Among the mechanisms proposed for pericyte death is exposure to AGE, which accumulate during diabetes. The current study used an in vitro model, whereby retinal pericytes were exposed to AGE-modified substrate and the mechanisms underlying pericyte death explored.Methods Pericytes were isolated from bovine retinal capillaries and propagated on AGE-modified basement membrane (BM) extract or non-modified native BM. The extent of AGE modification was analysed. Proliferative responses of retinal pericytes propagated on AGE-modified BM were investigated using a 5-bromo-2-deoxy-uridine-based assay. The effect of extrinsically added platelet-derived growth factor (PDGF) isoforms on these proliferative responses was also analysed alongside mRNA expression of the PDGF receptors. Apoptotic death of retinal pericytes grown on AGE-modified BM was investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling labelling, mitochondrial membrane depolarisation and by morphological assessment. We also measured both the ability of PDGF to reverse Akt dephosphorylation that was mediated by AGE-modified BM, and increased pericyte apoptosis.Results Retinal pericytes exposed to AGE-modified BM showed reduced proliferative responses in comparison to controls (p<0.05–0.01), although this effect was reversed at low-AGE modifications. PDGF mRNA levels were differentially altered by exposure to low and high AGE levels, and AGE-modified BM caused significantly increased apoptosis in retinal pericytes. Pre-treatment of AGE-modified BM with PDGF-AA and -BB reversed the apoptosis (p<0.05–0.001) and restored Akt phosphorylation in retinal pericytes.Conclusions/interpretation Evidence suggests that substrate-derived AGE such as those that occur during diabetes could have a major influence on retinal pericyte survival. During diabetic retinopathy, AGE modification of vascular BM may reduce bioavailability of pro-survival factors for retinal pericytes.Conflict of interest: None of the authors have a conflict of interest.     

Aging: role and control of glycation

PURPOSE: Advanced glycation end-products (AGEs) accumulate in aging tissues and organs during rheumatoid arthritis and Alzheimer disease. These aging toxins are especially involved in cell alteration during diabetes mellitus (glycotoxin) and renal failure (uremic toxin). AGEs participate to the endothelial dysfunction leading to diabetic macro but also micro-angiopathy. AGEs binding to cell receptors are critical steps in the deleterious consequences of AGE excess. AGE-receptor activation altered cell and organ functions by a pro-inflammatory, pro-coagulant and pro-fibrosis factors cell response. CURRENT KNOWLEDGE AND KEY POINTS: Non-enzymatic glycation and glycoxidation with glucose auto-oxidation represent the two main pathways resulting in AGE formation. No exclusive AGE classification is actually available. Pathophysiological mechanisms are described to explain AGE toxicity. AGEs bind to cell receptors inducing deleterious consequences such as endothelial dysfunction after endothelial RAGE activation. AGEs can also have deleterious effects through glycated protein accumulation or in situ protein glycation. FUTURE PROSPECTS AND PROJECTS: Many in vitro or animal studies demonstrated that AGE deleterious effects can be prevented by glycation inhibitors, AGE cross-link breakers or AGE-RAGE interaction inhibition. New molecules are actually studied as new strategy to prevent or treat the deleterious effects of these aging toxins.     

AGEs,rather than hyperglycemia,are responsible for microvascular complications in diabetes: A “glycoxidation-centric” point of view

AimsAdvanced glycation end products (AGE) excess is one of the most important mechanisms involved in the pathophysiology of chronic diabetic complications. This review first summarizes the role of these compounds in microvascular pathogenesis, particularly in the light of recently proposed biochemical mechanisms for diabetic retinopathy, nephropathy and neuropathy. Then we focus on the relationship between AGE and metabolic memory, trying to clarify the former's role in the missing link between micro- and macrovascular complications.Data synthesisAn excessive AGE formation has been demonstrated in the newly disclosed biochemical pathways involved in the microvascular pathobiology of type 2 diabetes, confirming the central role of AGE in the progression of diabetic neuropathy, retinopathy and nephropathy. As shown by recent studies, AGE seem to be not "actors", but "directors" of processes conducting to these complications, for at least two main reasons: first, AGE have several intra- and extracellular targets, so they can be seen as a "bridge" between intracellular and extracellular damage; secondly, whatever the level of hyperglycemia, AGE-related intracellular glycation of the mitochondrial respiratory chain proteins has been found to produce more reactive oxygen species, triggering a vicious cycle that amplifies AGE formation. This may help to explain the clinical link between micro- and macrovascular disease in diabetes, contributing to clarify the mechanisms behind metabolic memory.ConclusionsThe pathophysiological cascades triggered by AGE have a dominant, hyperglycemia-independent role in the onset of the microvascular complications of diabetes. An effective approach to prevention and treatment must therefore focus not only on early glycemic control, but also on reducing factors related to oxidative stress, and the dietary intake of exogenous AGE in particular.     

肝细胞生长因子对糖基化终产物诱导内皮细胞凋亡的影响

目的探讨糖基化终产物对内皮细胞的凋亡作用,以及肝细胞生长因子对内皮细胞凋亡的影响。方法体外培养人脐静脉内皮细胞,予不同浓度糖基化终产物及肝细胞生长因子干预,分为实验对照组及100 mg/L、200mg/L4、00 mg/L糖基化终产物组和400 mg/L糖基化终产物 100μg/L肝细胞生长因子组,采用四甲基偶氮唑蓝比色法测定各组内皮细胞生长抑制率,通过吖啶橙荧光染色观察细胞形态学变化,流式细胞术测定Annexin V-FITC/PI双染标记的细胞凋亡率,检测肝细胞生长因子对糖基化终产物诱导内皮细胞凋亡的影响;蛋白免疫印迹法分析各组凋亡基因Bax、Bcl-2蛋白的表达及酶联反应法测定细胞凋亡蛋白酶3的活性。结果肝细胞生长因子能明显降低糖基化终产物对内皮细胞生长的抑制作用(P<0.01);糖基化终产物诱导培养的内皮细胞出现明显的凋亡形态学改变,在一定浓度范围内,内皮细胞凋亡率与糖基化终产物的浓度和作用时间呈依赖关系,肝细胞生长因子干预后可显著降低不同时间的内皮细胞凋亡率(P<0.05);肝细胞生长因子作用内皮细胞抗凋亡基因Bcl-2表达明显升高(P<0.01),而促凋亡基因Bax表达无明显变化(P>0.05);细胞凋亡蛋白酶3活性显著降低(P<0.05)。结论糖基化终产物诱导人内皮细胞凋亡,而肝细胞生长因子抑制糖基化终产物诱导的内皮细胞凋亡,其作用机制可能是上调抗凋亡基因Bcl-2水平、抑制细胞凋亡蛋白酶3的激活。     

Endogenous p53 protects vascular smooth muscle cells from apoptosis and reduces atherosclerosis in ApoE knockout mice

Recent studies have indicated that the tumor suppressor gene p53 limits atherosclerosis in animal models; p53 expression is also increased in advanced human plaques compared with normal vessels, where it may induce growth arrest and apoptosis. However, controversy exists as to the role of endogenous levels of p53 in different cell types that comprise plaques. We examined atherosclerotic plaque development and composition in brachiocephalic arteries and aortas of p53-/-/ApoE-/- mice versus wild type p53 controls. p53-/- mice demonstrated increased aortic plaque formation, with increased rates of cell proliferation and reduced rates of apoptosis in brachiocephalic arteries. Although most proliferating cells were monocyte/macrophages, apoptotic cells were both vascular smooth muscle cells (VSMCs) and macrophages. Transplant of p53 bone marrow to p53-/-/ApoE-/- mice reduced aortic plaque formation and cell proliferation in brachiocephalic plaques, but also markedly reduced apoptosis. To examine p53 regulation of these processes, we studied proliferation and apoptosis in macrophages, bone marrow stromal cells and VSMCs cultured from these mice. Although endogenous p53 promoted apoptosis in macrophages, it protected VSMCs and stromal cells from death, a hitherto unknown function in these cells, in part by inhibiting DNA damage response enzymes. p53 also inhibited stromal cell expression of VSMC markers. We conclude that endogenous levels of p53 protect VSMCs and stromal cells against apoptosis, while promoting apoptosis in macrophages, and protect against atherosclerosis development.     

阿托伐他汀对高同型半胱氨酸血症诱发动脉粥样硬化的干预作用

目的:观察阿托伐他汀对动脉粥样硬化斑块的影响, 并对其作用机制进行初步探讨。方法: 20 g/L L-蛋氨酸灌胃法建立ApoE基因敲除小鼠高同型半胱氨酸血症(hyperhomocysteinemia,HHcy)模型,按实验分组, 给予不同剂量阿托伐他汀治疗1个月后,用高效液相色谱荧光法测定血浆同型半胱氨酸(Hcy)水平,相差显微镜下观察小鼠主动脉根部病理学形态,免疫组织化学法检测主动脉血管平滑肌SM-α-actin的表达,TUNEL法检测小鼠主动脉斑块中的细胞凋亡指数,NBT及光泽精化学发光法检测血管局部活性氧(reactive oxygen species,ROS)水平, 光泽精化学发光法检测主动脉血管NADPH氧化酶(NADPH oxidase,Nox)活性,Western印迹法检测Nox4蛋白表达。结果: ApoE-/-小鼠蛋氨酸喂养3个月后,血浆Hcy水平升高,AS斑块形成。阿托伐他汀治疗1个月后,呈剂量依赖性地降低小鼠血浆Hcy水平,延缓AS病变的进程,减少斑块内凋亡细胞数量,降低了血管壁局部ROS水平,Nox活性及Nox4蛋白表达（均P<0.05）。结论: 阿托伐他汀治疗后,HHcy ApoE-/-小鼠AS病变进程延缓,其作用机制与其下调Nox4来源的ROS水平、抑制血管内皮细胞凋亡有关。     

Glycation and insulin resistance: novel mechanisms and unique targets?

Multiple biochemical, metabolic, and signal transduction pathways contribute to insulin resistance. In this review, we present evidence that the posttranslational process of protein glycation may play a role in insulin resistance. The posttranslational modifications, the advanced glycation end products (AGEs), are formed and accumulated by endogenous and exogenous mechanisms. AGEs may contribute to insulin resistance by a variety of mechanisms, including generation of tumor necrosis factor-α direct modification of the insulin molecule, thereby leading to its impaired action, generation of oxidative stress, and impairment of mitochondrial function, as examples. AGEs may stimulate signal transduction via engagement of cellular receptors, such as receptor for AGEs. AGE-receptor for AGE interaction perpetuates AGE formation and cellular stress via induction of inflammation, oxidative stress, and reduction in the expression and activity of the enzyme glyoxalase I that detoxifies the AGE precursor, methylglyoxal. Once set in motion, glycation-promoting mechanisms may stimulate ongoing AGE production and target tissue stresses that reduce insulin responsiveness. Strategies to limit AGE accumulation and action may contribute to the prevention of insulin resistance and its consequences.