γ- 分泌酶抑制剂对糖基化终产物作用下心肌微血管 内皮细胞的影响

目的:探讨Notch信号特异性阻断剂γ-分泌酶抑制剂(DAPT)对AGEs作用下的心肌微血管内皮细胞的增殖、迁移、管样结构的影响。方法:SD大鼠心肌微血管内皮细胞体外分离培养后,以不同浓度DAPT(0.25、0.5、1.0、5.0、10μmol/L)干预200mg/LAGEs作用下的CMECs24h,或者与DAPT(5μmol/L)孵育不同时间(24h、48h、72h、96h、120h),采用MTT比色法检测细胞的增值能力;用Transwell法检测细胞的迁移能力;用毛细血管管样结构形成实验检测DAPT对血管新生的影响。结果:DAPT显著抑制AGEs作用下的心肌微血管内皮细胞的存活,同时浓度越高、时间越长,其抑制效果越明显。结论:DAPT通过阻断Notch信号通路,能抑制AGEs作用下的心肌微血管内皮细胞的增殖及血管新生,促进细胞凋亡。     

血管衰老及心血管疾病

血管衰老是高血压、冠心病、主动脉夹层等心血管疾病的独立危险因素,而血管内皮细胞和平滑肌细胞的衰老则是血管衰老的细胞学基础.本文主要讨论了内皮细胞和平滑肌细胞衰老的形态学特征、分子标志物以及衰老的机制;阐述了单细胞测序、细胞衰老清理(senolytics)技术和遗传在血管细胞衰老及老年血管疾病诊断和治疗中的研究进展;最后...     

次声作用后血管内皮细胞超微结构的实验观察

目的: 观察8 Hz、130 dB次声不同时间暴露后大鼠血管内皮细胞的超微结构及血管内皮生长因子(VEGF)的表达.方法: 用8 Hz、130 dB的次声连续作用大鼠1 d、7 d、14 d,每天2 h,观察血管内皮细胞超微结构及VEGF表达的改变.结果: 在次声暴露期间,与对照组比较,7 d时内皮细胞出现线粒体肿胀和内质网扩张,14 d时出现内皮细胞脱落;VEGF表达随时间较对照组增强.结论: 次声可引血管内皮细胞超微结构与VEGF表达的变化,这些变化和次声暴露的时间有关.     

过表达bFGF促进大鼠急性缺血心肌的毛细血管生成

研究过表达人碱性成纤维细胞生长因子（basic fibroblast growth factor, bFGF）在大鼠急性心肌缺血模型中的表达及其对心肌血管 再生的影响. 将含人bFGF质粒pcDNA/b转染人脐带静脉内皮细胞（HUVEC） ,进行MTT检测. pcDNA/b转染人肾细胞293细胞系,进行G418稳定筛选, Western 印迹检测.建立大鼠急性心肌梗死模型,分别将生理盐水、空质粒 pcDNA3.1(+)和pcDNA/b分3点注射于梗死交界处心肌内4周后取材,做常规 HE 染色和Masson 染色,测量各组微血管数量和梗死面积. 经免疫组织化 学染色鉴定和电镜观察,过表达外源bFGF可以促进HUVEC（细胞）生长; pcDNA/b能在293细胞中高效表达外源bFGF基因. pcDNA/b注射组梗死交界处 可见大量新生血管,毛细血管总数明显大于对照组,梗死面积明显小于对 照组. pcDNA/b组在梗死交界区有bFGF阳性表达.电镜观察显示,在梗死交界 处心肌细胞间有毛细血管增生,分化成2个血管腔.本实验证明,过表达bFGF 具有促进大鼠急性缺血心肌的毛细血管生成的作用,为bFGF基因治疗缺血 性心肌病的研究提供实验基础.     

T16Ainh-A01对耳蜗血管纹毛细血管内皮细胞凋亡及衰老的影响*

目的: 原代培养豚鼠耳蜗血管纹毛细血管内皮细胞(ECs),探讨跨膜蛋白16A(TMEM16A)在耳蜗血管纹毛细血管ECs衰老过程中的变化及对耳蜗血管纹毛细血管ECs凋亡及衰老的影响。方法: 原代培养耳蜗血管纹毛细血管ECs,细胞传代构建衰老模型并根据CCK-8及β-半乳糖苷酶(SA-β-gal)染色评估细胞衰老程度,衰老细胞被随机分为衰老组(P12)、溶剂组(P12+DMSO)、T16Ainh-A01组(P12+T16Ainh-A01),免疫荧光及Western blot检测TMEM16A在ECs上的表达及分布,流式细胞术检测各组细胞凋亡率,Western blot检测各组Bax、Bcl-2、cleaved casepase-3蛋白表达水平。结果: 原代培养的耳蜗血管纹毛细血管ECs阳性率在95%以上,并确定第12代耳蜗血管纹毛细血管ECs为衰老组,与年轻组ECs相比,衰老组ECs上TMEM16A荧光及蛋白表达显著增强(P＜0.05),细胞凋亡率升高,衰老组给予T16Ainh-A01干预24 h后,Bax、cleaved casepase-3的蛋白表达下调(P＜0.01),Bcl-2的蛋白表达上调(P＜0.05),凋亡率下降且SA-β-gal阳性细胞率明显下降(P＜0.01)。结论: 衰老耳蜗血管纹毛细血管ECs凋亡增多且TMEM16A表达增加,TMEM16A特异性阻断剂T16Ainh-A01可以降低耳蜗血管纹毛细血管ECs的凋亡和衰老程度,提示TMEM16A可能参与耳蜗血管纹毛细血管ECs的凋亡和衰老过程。     

大鼠骨髓间充质干细胞分化的内皮样细胞促进血管新生及Rho激酶的作用

本文研究大鼠骨髓间充质干细胞分化生成的内皮样细胞(rat bone marrow mesenchymal stem cells-differentiated endothelial like cells,rBMSC-ECs)在血管新生中的作用及Rho激酶(Rho kinase,ROCK)活性抑制的影响。实验建立rBMSC-ECs与主动脉环体外共培养实验模型,设单纯血管环组、血管环与细胞共培养组和HA-1077低、中、高浓度组,HA-1077组在共培养的基础上分别在培养液中加不同浓度(10、30、60mmol/L)的ROCK特异抑制剂HA-1077。结果显示,培养第3天,血管环与细胞共培养组新生微血管数是单纯血管环组的1.3倍(P<0.05);HA-107710、30和60mmol/L组较共培养组分别减少57.70%、64.13%和48.23%(均P<0.01)。第6天,共培养组及HA-1077组rBMSC-ECs数量明显增加,并迁移至血管环周边,新生微血管生长缓慢;HA-1077组新生微血管数较共培养组明显减少。第9天,共培养组新生微血管部分增粗、增厚、延长,部分退化;一些rBMSC-ECs出芽,形成毛细血管...     

趋化因子在血管生成中的作用

趋化因子可影响血管生成,或通过对内皮细胞的趋化作用,引起血管内皮细胞增殖,毛细血管形成而促进血管生成;或通过抑制多种促血管生成因子活性而发挥抑制血管生成的作用。趋化因子和其他多种血管生成相关性因子组成网络,共同参与血管生成的调控。此外,CXC簇趋化因子SDF－1α也参与胃肠血管的发育过程。     

葡萄果实发育过程中果肉细胞超微结构的观察

用透射电镜观察了“巨峰”葡萄(Vitis vinifera×V.labrusca)果实3个发育时期中果肉细胞超微结构的变化。果实第一次快速生长期的果肉细胞超微结构表现出物质和能量代谢旺盛的特点。缓慢生长期的果实虽外部形态平静少变,但果肉细胞超微结构表现出深刻的变化:细胞核形状特化为裂瓣状是最显著的特点;线粒体数目丰富;粗面内质网槽库膨大形成的囊泡富集,出现向液泡汇融和向质膜靠近的现象;质膜内陷;液泡膜完整。另外,原生质也出现一些降解的现象。但总体结构特点表明果肉细胞在此期处于十分活跃的物质周转代谢和信息交换过程中。果实第二次快速生长期果肉细胞超微结构表现出衰老降解的特点,但线粒体结构依然完整,数量仍然丰富,原生质膜也保持了很好的完整性,这似乎与维持第二次快速生长或成熟有关。     

油酸所致急性肺水肿机制的研究

为了探讨呼吸窘迫综合征（Respiratory Distress Syndrome简称RDS）时急性肺水肿的机制,我们应用静脉注射油酸引起RDS模型研究的肺血管及血管内皮细胞的损伤变化。我们的实验发现肺损伤后系数明显升高,证实油酸引起肺损伤早期确实存在急性肺水肿;肺微血管面积密度增大定量反映肺组织中血管扩张,充血;血浆6-酮-PGF1α和TxB2含量变化以及Ｐ／Ｔ比值呈增加趋势提示该变化与血扩张有密切关系;血清ACE活性升高表明血管内皮细胞膜受到损伤;此外形态学观察也发现血内皮细胞有形态及功能改变,提示血管内皮细胞是 引起急性肺水肿更直接的原因。     

桂皮醛上调Nrf2改善衰老大鼠血管内皮功能障碍

目的:探讨桂皮醛对衰老大鼠模型血管内皮功能的影响及相关机制。方法:通过建立24月龄自然衰老的Sprague Dawley(SD)大鼠模型及第14代的衰老人脐静脉内皮细胞模型(HUVECs),以桂皮醛(10μM)进行体外干预,分别以DHE染色和DAF-2DA染色观察桂皮醛对颈动脉内膜和HUVEC中超氧阴离子、一氧化氮水平的影响。以微血管张力测定仪观察桂皮醛对乙酰胆碱诱导的颈动脉内皮依赖性舒张功能和硝酸甘油诱导的非内皮依赖性舒张功能的影响。Western blotting观察磷酸化eNOS水平及Nrf2表达。结果:桂皮醛孵育显著减少改善衰老大鼠颈动脉内膜和衰老HUVEC的ROS水平,促进HUVEC中eNOS的磷酸化,增加NO水平,改善乙酰胆碱诱导的血管内皮依赖性舒张功能,对硝酸甘油诱导的非内皮依赖性舒张功能无显著的影响;Nrf2的抑制剂鸦胆子苦醇可显著阻断桂皮醛的作用。结论:桂皮醛通过Nrf2通路减少衰老相关的ROS生成,增加NO水平从而改善衰老大鼠血管内皮依赖性舒张功能。     

Survivin expression in the stomach: implications for mucosal integrity and protection

Survivin, an apoptosis inhibitor, is highly expressed in a majority of human cancers and is required during embryonic development. Our present studies show that survivin is also expressed in normal gastric mucosa of adult humans and rats. In both human and rat gastric mucosa, survivin is expressed predominantly in the nuclei of mucosal surface epithelial cells. In rats, survivin is also detected in the nuclei of some neck cells, whereas in the humans, survivin is expressed in both nuclei and cytoplasm of chief and parietal cells. Furthermore, survivin is expressed at higher levels in the nuclei of cultured gastric mucosal epithelial cells than in gastric microvascular endothelial cells, which supports the expression pattern in intact tissues. Based on these expression studies, and the known role of survivin as an anti-apoptosis protein, survivin may play a role in maintaining gastric mucosal integrity and regulating cell renewal in the gastric mucosa.     

Role of histamine and acid back-diffusion in modulation of gastric microvascular permeability and hemorrhagic ulcers in Salmonella typhimurium-infected rats

Documentation concerning the pathogenesis of gastric hemorrhagic ulcer in Salmonella typhimurium (Salmonella typhi)-infective disease is lacking. This research first proposed that alterations of mast cell histamine release, gastric acid back-diffusion and mucosal microvascular permeability are important in modulating gastric ulcer and hemorrhage in Salmonella typhi-infected rats. Additionally, effects of several histamine-related drugs on this ulcer model were evaluated. Male Wistar rats were deprived food for 36 h. Live cultures of Salmonella typhi (OU 5045, 1 x 10(10) CFU in 1.0 mL of sterilized phosphate buffer saline) were challenged, intrajejunally to rats just before withdrawal of food. Control rats received the same volume of sterilized vehicle only. Rat stomachs were irrigated for 3 h with either normal saline or simulated gastric juice. Gastric acid back-diffusion, mucosal histamine concentration, microvascular permeability as well as luminal hemoglobin content and ulcer areas were determined. Severe gastric hemorrhage and mucosal ulcerations, particularly in acidic stomachs, were observed in Salmonella typhi-infected rats. A positive correlation of histamine to gastric hemorrhage and ulcer was found in those rats with Salmonella typhi-infection. This hemorrhagic ulcer in Salmonella typhi-infected rats was effectively ameliorated by intraperitoneal ketotifen, diphenhydramine and ranitidine but was worsen by exogenous histamine or diamine oxidase. In conclusion, enhancement of acid back-diffusion, mast cell histamine release and microvascular permeability is important in modulating gastric hemorrhage and ulcer in Salmonella typhi-infected rats.     

Angiogenic factors and alveolar vasculature: development and alterations by injury in very premature baboons

Proper formation of the pulmonary microvasculature is essential for normal lung development and gas exchange. Lung microvascular development may be disrupted by chronic injury of developing lungs in clinical diseases such as bronchopulmonary dysplasia. We examined microvascular development, angiogenic growth factors, and endothelial cell receptors in a fetal baboon model of chronic lung disease (CLD). In the last third of gestation, the endothelial cell marker platelet endothelial cell adhesion molecule (PECAM)-1 increased 7.5-fold, and capillaries immunostained for PECAM-1 changed from a central location in airspace septa to a subepithelial location. In premature animals delivered at 67% of term and supported with oxygen and ventilation for 14 days, PECAM-1 protein and capillary density did not increase, suggesting failure to expand the capillary network. The capillaries of the CLD animals were dysmorphic and not subepithelial. The angiogenic growth factor vascular endothelial growth factor (VEGF) and its receptor fms-like tyrosine kinase receptor (Flt-1) were significantly decreased in CLD. Angiopoietin-1, another angiogenic growth factor, and its receptor tyrosine kinase with immunoglobulin and epidermal growth factor homology domains were not significantly changed. These data suggest that CLD impairs lung microvascular development and that a possible mechanism is disruption of VEGF and Flt-1 expression.     

Endothelialized Microfluidics for Studying Microvascular Interactions in Hematologic Diseases

Advances in microfabrication techniques have enabled the production of inexpensive and reproducible microfluidic systems for conducting biological and biochemical experiments at the micro- and nanoscales ^1,2. In addition, microfluidics have also been specifically used to quantitatively analyze hematologic and microvascular processes, because of their ability to easily control the dynamic fluidic environment and biological conditions^3-6. As such, researchers have more recently used microfluidic systems to study blood cell deformability, blood cell aggregation, microvascular blood flow, and blood cell-endothelial cell interactions^6-13.However, these microfluidic systems either did not include cultured endothelial cells or were larger than the sizescale relevant to microvascular pathologic processes. A microfluidic platform with cultured endothelial cells that accurately recapitulates the cellular, physical, and hemodynamic environment of the microcirculation is needed to further our understanding of the underlying biophysical pathophysiology of hematologic diseases that involve the microvasculature.Here, we report a method to create an "endothelialized" in vitro model of the microvasculature, using a simple, single mask microfabrication process in conjunction with standard endothelial cell culture techniques, to study pathologic biophysical microvascular interactions that occur in hematologic disease. This "microvasculature-on-a-chip" provides the researcher with a robust assay that tightly controls biological as well as biophysical conditions and is operated using a standard syringe pump and brightfield/fluorescence microscopy. Parameters such as microcirculatory hemodynamic conditions, endothelial cell type, blood cell type(s) and concentration(s), drug/inhibitory concentration etc., can all be easily controlled. As such, our microsystem provides a method to quantitatively investigate disease processes in which microvascular flow is impaired due to alterations in cell adhesion, aggregation, and deformability, a capability unavailable with existing assays.     

Protective effect of verapamil on gastric hemorrhagic ulcers in severe atherosclerotic rats

Studies concerning with pathogenesis of gastric hemorrhage and mucosal ulceration produced in atherosclerotic rats are lacking. The aim of this study is to examine the role of gastric acid back-diffusion, mast cell histamine release, lipid peroxide (LPO) generation and mucosal microvascular permeability in modulating gastric hemorrhage and ulcer in rats with atherosclerosis induced by coadministration of vitamin D2 and cholesterol. Additionally, the protective effect of verapamil on this ulcer model was evaluated. Male Wistar rats were challenged intragastrically once daily for 9 days with 1.0 ml/kg of corn oil containing vitamin D2 and cholesterol to induce atherosclerosis. Control rats received corn oil only. After gastric surgery, rat stomachs were irrigated for 3 h with either simulated gastric juice or normal saline. Gastric acid back-diffusion, mucosal LPO generation, histamine concentration, microvascular permeability, luminal hemoglobin content and ulcer areas were determined. Elevated atherosclerotic parameters, such as serum calcium, total cholesterol and low-density lipoprotein concentration were obtained in atherosclerotic rats. Severe gastric ulcers accompanied with increased ulcerogenic factors, including gastric acid back-diffusion, histamine release, LPO generation and luminal hemoglobin content were also observed in these rats. Moreover, a positive correlation of histamine to gastric hemorrhage and to ulcer was found in those atherosclerotic rats. This hemorrhagic ulcer and various ulcerogenic parameters were dose-dependently ameliorated by daily intragastric verapamil. Atherosclerosis could produce gastric hemorrhagic ulcer via aggravation of gastric acid back-diffusion, LPO generation, histamine release and microvascular permeability that could be ameliorated by verapamil in rats.     

Distribution of endothelial vesicles in the microvasculature of skeletal muscle and brain cortex of the rat,as demonstrated by tannic acid tracer analysis

Summary Ultrathin serial sectioning and labeling with tannic acid have demonstrated that most plasmalemmal vesicles of rat vascular endothelial cells are not free, but rather are conjoined in three dimensions to form racemose invaginations from the cell surfaces. To elucidate the distribution of vesicles in these microvascular endothelial cells, we have examined terminal arterioles, capillaries and post-capillary venules of rat skeletal muscle and brain cortex, using tannic acid labeling and stereological methods, and have determined the proportions of free vesicles and the vesicles of luminal and abluminal invaginations, as well as the numerical density of vesicles. In the case of capillaries, regional differences in distribution have also been studied. The ratio of free vesicles is 6–7% and is constant throughout the muscle microvasculature. The distribution (proportions and numerical densities) of vesicles in the brain and muscle microvascular endothelial cells shows regionally distinctive patterns. In rapid-frozen, freeze-substituted endothelial cells, there are almost as many fused vesicles as seen in chemically fixed cells. Therefore, aldehydes do not seem to induce membrane fusion, and the distribution of vesicles seems to be preserved by chemical fixation. The structure and function of plasmalemmal vesicles are discussed.     

An in vitro three-dimensional coculture model of cerebral microvascular angiogenesis and differentiation

Summary The microvasculature of the developing brain is plastic and responds differently to the many insults associated with preterm birth. We developed three-dimensional in vitro culture models for the study of the responses of the developing cerebral micro-vasculature. Beagle brain microvascular endothelial cells (BBMEC) were isolated by differential centrifugation from newborn beagle pups on postnatal Day 1 and placed in three-dimensional culture dispersed in a collagen gel. Alternatively, BBMEC were placed in a three-dimensional coculture with neonatal rat forebrain astrocytes. Cultures were analyzed for extracellular matrix components at 1 and 6 d, and total RNA was extracted for Northern analyses. Urokinase plasminogen activator activity was assayed in both mono- and cocultures of the two cell types. Studies of three-dimensional BBMEC/astrocyte cocultures demonstrated progressive tube formation with only low levels of endothelial proliferation. By 6 d in three-dimensional coculture, the BBMEC formed capillarylike tubes with a wrapping of glial processes, and basement membrane protein synthesis was noted. Urokinase plasminogen zymography suggested intercellular signaling by the two cell types. These data suggest that the three-dimensional beagle brain germinal matrix microvascular endothelial cell/neonatal rat astrocyte coculture provides a good model for the investigation of microvascular responses in the developing brain.     

Isolation and characterisation of human pulmonary microvascular endothelial cells from patients with severe emphysema

Background

Loss of the pulmonary microvasculature in the pathogenesis of emphysema has been put forward as a credible alternative to the classical inflammatory cell driven proteolysis hypothesis. Mechanistic studies in this area have to date employed animal models, immortalised cell lines, primary endothelial cells isolated from large pulmonary arteries and non-pulmonary tissues and normal human pulmonary microvascular endothelial cells. Although these studies have increased our understanding of endothelial cell function, their relevance to mechanisms in emphysema is questionable. Here we report a successful technique to isolate and characterise primary cultures of pulmonary microvascular endothelial cells from individuals with severe emphysema.

Methods

A lobe of emphysematous lung tissue removed at the time of lung transplantation surgery was obtained from 14 patients with severe end-stage disease. The pleura, large airways and large blood vessels were excised and contaminating macrophages and neutrophils flushed from the peripheral lung tissue before digestion with collagenase. Endothelial cells were purified from the cell mixture via selection with CD31 and UEA-1 magnetic beads and characterised by confocal microscopy and flow cytometry.

Results

Successful isolation was achieved from 10 (71%) of 14 emphysematous lungs. Endothelial cells exhibited a classical cobblestone morphology with high expression of endothelial cell markers (CD31) and low expression of mesenchymal markers (CD90, αSMA and fibronectin). E-selectin (CD62E) was inducible in a proportion of the endothelial cells following stimulation with TNFα, confirming that these cells were of microvascular origin.

Conclusions

Emphysematous lungs removed at the time of transplantation can yield large numbers of pulmonary microvasculature endothelial cells of high purity. These cells provide a valuable research tool to investigate cellular mechanisms in the pulmonary microvasculature relevant to the pathogenesis of emphysema.     

Comparative mucosal microvasculature of the mammalian stomach

The comparative morphology of the gastric mucosal microvasculature was investigated using the corrosion casting technique. The vascular pattern consisted of a hexagonally arranged capillary plexus surrounding the gastric glands and terminating in venules running perpendicular to the mucosal axis. Vessels of the pyloric antrum demonstrated an acute angle between capillaries and venules, whereas vessels of the gastroduodenal junction changed from a honeycomb pattern to a leaf-like arrangement.     

Biochemical examination on the increased superoxide dismutase-like plasma substance observed in a state of acute gastric mucosal lesions

When experimental acute gastric mucosal lesions were produced in guinea pig by water-immersion and restraint stress, superoxide dismutase (SOD)-like substance in the plasma increased. On analysis by gel filtration, it was shown that the molecular weight of the increased SOD-like plasma substance was about 130,000, and even after treatment with trypsin, 84% of this substance remained. Since the molecular weight of intracellular SOD is about 40,000, it seems that this substance is similar to extracellular SOD, located on the endothelial cell-surface, as previously reported by Marklund et al. Our results suggest that in the presence of acute gastric mucosal lesions, SOD-like plasma substance is not identical to intracellular SOD, which derived from cell destruction by stress or free radical-induced microvascular damage or by hemolysis. Furthermore, this substance may itself work as a scavenger of free radicals generated under conditions, such as these described in the present experiment.