壳聚糖抑制高糖诱导的脂质过氧化及血管内皮细胞与单核细胞黏附

目的研究壳聚糖(chitosan)对高糖诱导细胞产生脂质过氧化及血管内皮细胞与单核细胞黏附的抑制作用。方法建立人脐静脉血管内皮细胞(HUVEC)高糖培养模型,实验分空白对照组、高糖模型组、高糖+壳聚糖组,测定细胞产生羟自由基(OH.)及脂质过氧化产物丙二醛(MDA)量;同时取单核巨噬细胞系Raw264.7,以荧光染料Rhodamin123孵育后加入以上各组,荧光摄像及比色检测单核细胞黏附数量;RT-PCR法检测血管细胞黏附分子(VCAM-1)mRNA变化。结果与空白对照组比较,高糖引起HUVEC产生OH.及MDA含量增加,黏附于HUVEC的Raw264.7数量以及VCAM-1表达升高;壳聚糖可呈浓度依赖性地抑制上述现象,但对细胞存活无明显影响。结论壳聚糖可能通过减轻自由基与脂质过氧化损伤,下调血管内皮细胞VCAM-1的表达,从而抑制高糖诱导的单核细胞与内皮细胞黏附。     

Crosstalk between macrophages and smooth muscle cells in atherosclerotic vascular diseases

Macrophages and smooth muscle cells (SMCs) represent major players in the pathogenesis of atherosclerotic vascular diseases. SMCs often reside in close proximity to macrophage clusters. Activated macrophages may promote pro-atherogenic functions of SMCs. Addressing macrophage-dependent mechanisms of SMC activation may provide new insight into atherogenesis and new therapies for various vascular diseases. Direct evidence for such interplay between atherosclerosis-associated cell types, however, remains scant. While SMC-derived macrophage foam cells have long been reported, recent evidence has also identified SMC-like cells of monocyte origin, suggesting dynamic interchangeability of these cell types. Future efforts may help to understand the interplay between key cell types and offer new paradigms in vascular medicine and pharmacology.     

Autophagy in vascular endothelial cells

The importance of autophagy in cardiovascular physiology and cardiovascular disease is increasingly recognized; however, the precise biological effects and underlying mechanisms of autophagy in the cardiovascular system are still poorly understood. In the last few years, the effects of autophagy in endothelial cells have attracted great interests. This article provides a summary of our current knowledge on the regulatory factors, signalling mechanisms, and functional outcomes of autophagy in endothelial cells. It is suggested that in most situations, induction of an autophagic response has cytoprotective effects. The beneficial effects of autophagy in endothelial cells are likely to be context‐dependent, since autophagy may also contribute to cell death under certain circumstances. In addition to regulating endothelial cell survival or death, autophagy is also involved in modulating other important functions, such as nitric oxide production, angiogenesis and haemostasis/thrombosis. The mounting data will help us draw a clear picture of the roles of autophagy in endothelial cell biology and dysfunction. Given the pivotal role of endothelial dysfunction in the pathogenesis of vascular disease, disruptions of autophagy in endothelial cells are likely to have significant contributions. This is supported by some preliminary ex vivo data indicating that compromised autophagic functions may be important in the development of endothelial dysfunctions associated with diabetes and ageing.     

Relationship between prostaglandin E2 and vascular endothelial growth factor (VEGF) in angiogenesis in human vascular endothelial cells

To address the role of prostaglandin E2 (PGE2) in tube formation of endothelial cells and the relationships between the action of PGE2 and vascular endothelial growth factor (VEGF), cultured human umbilical vein endothelial cells (HUVECs) were used to evaluate tube formation on Matrigel and the expression of angiogenesis-related genes. PGE2 treatment stimulated the tube-like formation of HUVECs. Whereas VEGF-induced tube formation was significantly suppressed by ETYA, an inhibitor of arachidonic acid metabolism, or SU5614, an inhibitor of VEGF-receptor tyrosine kinase, the stimulatory effect of PGE2 was observed in the presence of ETYA or SU5614. Thus, PGE2 counteracted both ETYA- and SU5614-induced blockage of angiogenesis in the presence of VEGF. VEGF induced cyclooxygenase (COX) -2 mRNA expression in HUVECs and increased the PGE2 concentration in the medium. PGE2 treatment enhanced the expression of VEGF mRNA. These findings suggest that PGE2 directly stimulates angiogenesis, apart from VEGF signaling, and further induces VEGF expression in HUVECs. In addition, the effect of VEGF on angiogenesis may be mediated, in part, by PGE2 secretion.     

Interaction between monocytes and vascular smooth muscle cells enhances matrix metalloproteinase-1 production

Matrix metalloproteinase-1 (MMP-1) plays an important role in atherosclerotic plaque rupture. The purpose of this study was to investigate the expression of MMP-1 by cell-to-cell interactions between monocytes and vascular smooth muscle cells (VSMCs). Human VSMCs and THP-1 cells (human monocytoid cells) were cocultured. MMP-1 levels were measured by enzyme-linked immunosorbent assay. Collagenolytic activity was determined by fluorescent labeled-collagen digestion. Immunohistochemistry was performed to determine which types of cells produce MMP-1. Adding THP-1 cells to VSMCs markedly increased the MMP-1 levels and activity of the culture media. MMP-1 levels were maximal when the cellular ratio of THP-1 cells/VSMCs was 1.0. Immunohistochemistry revealed that both types of cells in the coculture produced MMP-1. Separated coculture experiments showed that both direct contact and a soluble factor(s) contributed to MMP-1 production. Neutralizing anti-interleukin (IL)-6 and tumor necrosis factor-alpha antibodies inhibited coculture conditioned medium-induced MMP-1 production by VSMCs and THP-1 cells. Protein kinase C inhibitors, tyrosine kinase inhibitors, and a mitogen-activated protein kinase inhibitor significantly inhibited MMP-1 production by cocultures. Direct cell-to-cell interaction between THP-1 cells and VSMCs enhanced MMP-1 synthesis in both types of cells. Increased local MMP-1 production and activity induced by monocyte-VSMC interaction play an important pathogenic role in atherosclerotic plaque rupture.     

血管内皮生长因子受体-3在血管内皮细胞和平滑肌细胞中的表达

目的探讨血管内皮细胞生长因子受体-3（VEGFR-3）在血管内皮细胞和平滑肌细胞中的表达。方法分离人脐带中的脐静脉和脐动脉,冰冻切片后以免疫荧光法检测VEGFR-3的表达。结果VEGFR-3荧光信号表达于脐静脉内皮细胞和平滑肌细胞,以及脐动脉内皮细胞、平滑肌细胞和外周细胞。结论血管内皮细胞和平滑肌细胞均表达VEGFR-3。     

The pleiotropic effects of ARB in vascular endothelial progenitor cells

Angiotensin II regulates blood pressure and contributes to endothelial dysfunction and the progression of atherosclerosis. Bone marrow-derived endothelial progenitor cells (EPCs) in peripheral blood contribute to postnatal vessel repair and neovascularization. Impaired EPC function in patients with hypertension and diabetes inhibits the endogenous repair of vascular lesions and leads to the progression of atherosclerosis. The number of EPCs in peripheral blood is inversely correlated with mortality and the occurrence of cardiovascular events. Angiotensin II-mediated signaling is implicated in oxidative stress, inflammation and insulin resistance, factors that cause EPC dysfunction. Blockade of the angiotensin II type 1 receptor may therefore present a new therapeutic target for enhancing EPC function.     

ATP release pathways in vascular endothelial cells

Vascular endothelial cells regulate vascular tonus, growth, and angiogenesis in response to mechanical stresses. ATP release is one of well-known mechanosensitive responses in endothelial cells. Released ATP induces Ca(2+) responses and nitric oxide production in neighboring cells in an auto/paracrine manner. Mechanosensitive and agonist-induced ATP releases are also observed in other cell types, but the cellular mechanisms and pathways of ATP release are largely unknown. Reported candidates for ATP release pathways are ABC proteins including P-glycoprotein and CFTR, exocytosis of ATP-containing vesicles, and ATP-permeable anion channels. In vascular endothelium, vesicular exocytosis, volume-regulated anion channels (VRAC), and connexin hemichannels have been reported as candidates for ATP release pathways. We found that VRAC inhibitors suppressed hypotonic stress-induced ATP release in bovine aortic endothelial cells. Furthermore, extracellular ATP suppressed VRAC current in a voltage dependent manner, which could be fitted to the permeation-blocker model with a Kd(0) of 1 mM and delta value of 0.41. However, it should be noted that VRAC is probably not the only pathway for ATP release in the endothelium, because basal ATP release was not inhibited by VRAC inhibitors. Further investigations are definitely warranted to clarify the details and therapeutic significance of mechanosensitive ATP release in the endothelium.     

雷公藤内酯抑制内皮细胞血管内皮生长因子表达与合成

目的:研究雷公藤内酯对血管内皮细胞生长因子(VEGF)mRNA表达及VEGF合成与分泌的影响,进一步探讨雷公藤内酯降低肾小球肾炎患者尿蛋白的作用机制。方法:以人内皮细胞系ECV-304为研究对象,利用半定量逆转录聚合酶链反应(RT-PCR),流式细胞仪,酶联免疫吸附法(ELISA)检测不同剂量雷公藤内酯对佛波脂(TPA)诱导的内皮细胞VEGFmRNA表达及VEGF合成与分泌的影响,用RT-PCR检测雷公藤内酯对内皮细胞c-fos/c-jun mRNA表达的影响。结果:TPA能够明显上调VEGF mRNA表达,蛋白合成与分泌。而雷公藤内酯可以抑制TPA诱导的内皮细胞VEGF mRNA表达及VEGF蛋白合成与分泌,该作用在10μg·L~(-1)时更为明显。同样,雷公藤内酯剂量依赖性地抑制TPA诱导的内皮细胞c-fos/c-jun mRNA的表达。结论:雷公藤内酯通过影响c-fos/c-jun基因转录而抑制内皮细胞VEGFmRNA表达及VEGF合成与分泌是雷公藤内酯降低肾小球肾炎患者尿蛋白的作用机制之一。     

Functional heterogeneity of vascular endothelial cells

This review has highlighted some of the well-described differences in endothelial cells derived from different sites of the vascular tree. In presenting a select group of endothelial properties, there was no intention to imply that these are the only properties of endothelial cells that exhibit heterogeneity. Nonetheless, having described endothelial heterogeneity in regard to a number of defined properties, we are left with persistent questions including: Are these divergent properties of endothelial cells fixed? Alternatively, can we alter the properties of endothelial cells by affecting the signals from the environment? A number of reports strongly suggest that endothelial cells are capable of acquiring new properties. Stewart and Wiley investigated the role of the neural tissue environment on the differentiation of brain capillary endothelial cells. These authors transplanted ectopic sites, i.e. vascular segments of brain from very young quail embryos to chick coeliac cavity, and a quail somites to chick brain ventricles. The distinctive morphology of quail cells provided a cell marker to differentiate host from graft. The results of this study demonstrated that mesenteric or somatic vessels growing into grafted brain developed functional, structural and histochemical features specific for neural capillaries. Conversely, capillaries in mesodermal tissue that had been grafted to the brain were devoid of the neural capillary characteristics, indicating that brain vessels do not form a barrier when they are made to vascularize non-neural tissue. Milici and Carley reported that bovine adrenal capillary cells cultured on plastic exhibited occasional diaphragmed fenestrations and no transendothelial channels. However, if these same cells were cultured on a basement membrane (matrix) laid down by MDCK cells (a canine nephron epithelial cell line), the cells responded by increasing the number of diaphragmed fenestrations and transendothelial channels. This cell culture study supported an earlier whole animal study in which the importance of the epithelium and/or epithelial basal lamina in the maintenance of endothelial ultrastructure was demonstrated in a developmental study of rat intestinal capillaries. In this earlier study, it was noted that epithelial development coincided with the formation of fenestrations by the endothelium. Enzymatic activities of endothelial cells can also be altered by environmental signals. For example, primary cerebral microvascular endothelial cells exhibit barrier features and are enriched in gamma-glutamyl transpeptidase activity, yet rapidly lose the activity when subcultured.(ABSTRACT TRUNCATED AT 400 WORDS)     

Levamisole induced apoptosis in cultured vascular endothelial cells

To better understand the anticancer activity of Levamisole (LMS), which serves as an adjuvant in colon cancer therapy in combination with 5-Fluorouracil, this study analyses LMS' ability to induce apoptosis and growth arrest in cultured human micro- and macrovascular endothelial cells (ECs) and fibroblasts. Cells exposed (24 h) to Levamisole (range: 0.5 - 2 mmol l(-1)) alone or in combination with antioxidants (10 mmol l(-1) glutathione or 5 mmol l(-1) N-Acetylcysteine or 0.1 mmol l(-1) Tocopherol) were evaluated for apoptosis ((3)H-thymidine assays, in situ staining), mRNA/protein expression (Northern/Western blot), and proliferation ((3)H-thymidine incorporation). Levamisole dose-dependently increased apoptosis in ECs to 230% (HUVECs-human umbilical vein ECs), 525% (adult human venous ECs) and 600% (human uterine microvascular ECs) but not in fibroblasts compared to control cells (set as 100%). Levamisole increased in ECs integrin-dependent matrix adhesion, inhibited proliferation (-70%), reduced expression of survival factors such as clusterin (-30%), endothelin-1 (-43%), bcl-2 (-34%), endothelial NO-synthase (-32%) and pRb (Retinoblastoma protein: -89%), and increased that of growth arrest/death signals such as p21 (+73%) and bak (+50%). LMS (2 mmol l(-1))-induced apoptosis was inhibited by glutathione (-50%) and N-Acetylcysteine (-36%), which also counteracted reduction by Levamisole of pRb expression, suggesting reactive oxygen species and pRb play a role in these processes. The ability of LMS to selectively induce apoptosis and growth arrest in endothelial cells potentially hints at vascular targeting to contribute to Levamisole's anticancer activity.     

Insights into cholesterol efflux in vascular endothelial cells

Vascular endothelial dysfunction is considered an initial step of atherogenesis, and the complicated cellular events of atherosclerosis begin with focal inflammation leading to foam cell formation and accumulation of cholesterol in the subendothelial space. Of the cells that make up atherosclerotic plaque, vascular endothelial cells (ECs) are the most resistant to cholesterol accumulation. However, ECs express receptors for modified lipoproteins and have the biochemical pathways for sterol synthesis and receptor-mediated endocytosis of lipoproteins. Cholesterol efflux continues even when cellular cholesterol mass is unchanged. Therefore, cholesterol efflux pathways may play an important role in endothelial cholesterol homeostasis. Recent study results suggest that apolipoprotein A-I and high density lipoproteins promote cellular cholesterol efflux through mechanisms depending on ATP-binding cassette transporter A1 in ECs. Caveolae and its structural protein caveolin-1 are abundant in ECs and could be contributors to cholesterol trafficking as well. However, the roles of each pathway in efflux and homeostasis of cellular cholesterol in ECs are still controversial. This article reviews recent progress in the understanding of cholesterol efflux and underlying mechanisms in ECs and proposes a model of efflux of cellular cholesterol. Such a cholesterol efflux pathway could provide insight into the efficient removal of excess cellular cholesterol in preventing atherogenesis.     

Role of mechanical stress in monocytes/macrophages: implications for atherosclerosis

Hypertension is a well-known risk factor for atherosclerosis, but the molecular mechanisms that link elevated blood pressure to atherosclerosis progression remain uncertain. The interactions of mechanical forces and cells of the vasculature are relevant to many cardiovascular diseases. Once a monocyte infiltrates a tissue, it establishes extracellular matrix contacts and is subjected to deformation through those contacts. Macrophages participate in atherogenesis and commonly localize at sites of coronary plaque rupture. Although macrophages may be subjected to excess mechanical stress in these conditions, how biomechanical forces affect macrophage function remains incompletely defined. Recent work demonstrates that human monocytes/macrophages respond to mechanical deformation with selective augmentation of matrix metalloproteinases and induction of immediate-early genes. In human monocytes/macrophages and THP-1 cells, biomechanical strain can induce expression of the class A scavenger receptor, an important lipoprotein receptor in atherogenesis. In addition, DNA microarray analysis reveals that cyclic mechanical strain induces only a few genes (>2.5-fold), including interleukin-8 and IEX-1 in THP-1 cells. Thus, biomechanical deformation of monocytes/macrophages contributes to degradation of extracellular matrix, monocyte differentiation, and promotion of atherosclerosis. These findings suggest that mechanical stress in vivo, such as hypertension, may play an important role in atherogenesis and instability of coronary-artery plaques through biomechanical effects on vascular macrophages.     

金钠多 艾司洛尔减轻缺氧刺激内皮细胞分泌内皮素的作用比较

目的观察缺氧对血管内皮细胞(VEC)分泌内皮素(ET)的影响及金钠多和艾司洛尔的保护作用。方法将培养的血管内皮细胞分为4组:空白对照组、单纯缺氧组、缺氧+金钠多组、缺氧+艾司洛尔组。除空白对照组外,其他各组置于低压舱内进行缺氧暴露。用放射免疫法测定各组缺氧前和缺氧后0.5、6和24hET含量。结果①缺氧可促进VEC分泌ET增加(P<0.01)。②同单纯缺氧组比较,在缺氧后0.5、6、24h时,金钠多组的ET含量明显降低(P<0.01)。③同单纯缺氧组比较,在缺氧后0.5h艾司洛尔组的ET含量明显降低(P<0.01),但在缺氧后6h和24h时,两组ET含量差异无统计学意义(P>0.05)。④金钠多组与艾司洛尔组比较,ET浓度降低在0.5h差异无统计学意义(P>0.05),但在6h和24h金钠多组ET含量较艾司洛尔组明显降低(P<0.01)。结论缺氧可使VEC释放ET显著增加;金钠多和艾司洛尔能抑制缺氧促VEC分泌ET的作用;金钠多的保护作用更强于艾司洛尔。     

血管内皮细胞体外损伤模型

目的 研究系统性红斑狼疮(SLE)患者血管内皮细胞(VEC)体外损伤模型的建立方法,为进一步治疗SLE血管病变的研究奠定基础.方法 收集5例活动期SLE患者血清,以此血清刺激人脐静脉内皮细胞株(ECV-304),酶联免疫吸附法(ELISA)检测培养上清液中血管假性血友病因子(vWF)、可溶性血栓调节蛋白(sTM)含量.结果 SLE患者血清致ECV-304培养上清液中vWF、sTM含量增加,与对照组比较(P<0.05).结论 活动期SLE患者血清体外可损伤血管内皮细胞.     

Nicorandil inhibits serum starvation-induced apoptosis in vascular endothelial cells

The Impact Of Nicorandil in Angina (IONA) randomized trial showed a significant reduction in coronary events, in patients with stable angina treated with a KATP channel opener, nicorandil. However, the impact of nicorandil on endothelial apoptosis remains to be examined. We tested the hypothesis that nicorandil has anti-apoptotic effects in endothelial cells (ECs). Apoptosis was induced by serum starvation in the culture media in human umbilical vein endothelial cells. We examined the effects of nicorandil on endothelial cell apoptosis. Cell viability after serum starvation was significantly higher in the nicorandil-treated group compared with the control group (81 +/- 8% vs. 63 +/- 3%, P < 0.01). Apoptosis, as detected by caspase 3 activation and Hoechst 33258 assay, induced by serum starvation was also effectively abrogated by the treatment of nicorandil (100 muM). The protective effects of nicorandil on endothelial survival were significantly inhibited by a specific mitochondrial KATP channel blocker, 5-Hydroxydecanoic acid. A mitochondrial permeability transition pore activator significantly abolished the anti-apoptotic effect of nicorandil in endothelial cells, indicating that the mechanism of protective effect of nicorandil is involved in the mitochondrial apoptotic pathway although it affects neither Bcl-2 nor Bax protein expression levels. In conclusion, nicorandil inhibits serum starvation-induced endothelial cell apoptosis possibly through mitochondrial KATP channels.     

动脉粥样硬化血管内皮分泌功能失调与平滑肌细胞增殖

血管内皮细胞和平滑肌细胞是血管壁两种主要细胞,两者在结构上和功能上有着密切的关系,动脉粥样硬化的发生源于循环因子和血管壁细胞间的相互作用,内皮细胞损伤等所导致的分泌功能失调和平滑肌细胞的异常增殖而引起的血管腔狭窄和痉挛是动脉粥样硬化等多种血管疾病发生发展的共同病理基础。本文从动脉粥样硬化病理状态下血管内皮分泌的生长因子、细胞因子、血管活性物质对平滑肌细胞增殖影响的最新研究进展做一综述。     

乳腺癌髓系来源抑制细胞与外周血单核细胞的相关性及对预后的影响

目的　探讨乳腺癌术后患者肿瘤浸润髓系来源抑制细胞（MDSCs）与外周血白细胞的相关性及对术后无复发生存时间（RFS）的影响。方法　收集32例接受根治性手术的乳腺癌患者的临床病理资料及肿瘤浸润MDSCs比例,分析不同临床病理特征患者MDSCs比例差异。Spearman相关分析MDSCs与外周血白细胞的关系。根据MDSCs中位数将患者分为高MDSCs组（≥4.4%,16例）和低MDSCs组（＜4.4%,16例）,分析2组患者RFS的差异。结果　不同临床病理特征患者中,仅Ⅲ期乳腺癌患者肿瘤浸润MDSCs比例高于Ⅰ~Ⅱ期患者（P＜0.05）。肿瘤浸润MDSCs比例与外周血单核细胞计数、单核细胞/淋巴细胞比值（MLR）呈正相关（rs分别为0.405、0.408,均P＜0.05）。总体分析结果显示,高、低MDSCs组RFS分别为（102.7±9.1）个月、（107.9±8.3）个月,差异无统计学意义（Log-rank χ2=1.166,P＞0.05）;分层分析结果显示,在17例无淋巴结转移患者中,高MDSCs组RFS明显较低MDSCs组缩短［平均RFS分别为（97.4±31.9）个月、（117.8±15.9）个月,Log-rank χ2=5.402,P＜0.05］。结论　乳腺癌肿瘤浸润MDSCs比例与外周血单核细胞计数、MLR呈正相关,无淋巴结转移患者高MDSCs组RFS更差。