肝窦内皮细胞的结构及其功能

肝窦内皮细胞是肝脏非实质细胞的主要细胞群，由肝窦内皮细胞构成的肝窦壁是全身毛细血管壁中唯一缺乏基膜的毛细血管窗孔，足肝窦内皮细胞最具特征性的结构。肝窦内皮细胞在调节肝窦血流与周围组织的物质交换中起有效的中枢性的作用，因此肝窦内皮细胞对于维持正常的肝功能起十分重要的作用。同时肝窦内皮细胞在肝脏的生理病理过程中发挥着诸多的重要功能。     

肝窦内皮细胞的研究进展

目的分析并总结肝窦内皮细胞的表型标志以及其在肝脏疾病发生、发展过程中的作用的研究进展情况。方法以＂肝窦内皮细胞＂、＂肝再生＂及＂肝脏疾病＂作为关键词,利用PubMed、万方、CNKI等数据库检索近年来关于肝窦内皮细胞与肝脏疾病研究的相关文献并进行综述。结果肝窦内皮细胞具有特殊的细胞结构及表型标志,在肝脏再生、肝脏免疫耐受、肝脏纤维化及肝脏损伤的过程中最先感受＂损伤信息＂,并且作为第一道屏障既起着保护肝脏的作用,同时也是肝脏损伤的最初改变,在肝脏疾病发生、发展的过程中起着重要的作用。结论肝窦内皮细胞功能复杂,其在肝脏疾病病变过程中具体如何发挥作用及发挥作用的机制尚不明确,有待进一步研究。     

冷保存供肝肝移植大鼠肝窦内皮细胞损伤机制的研究

目的 探寻肝移植大鼠肝窦内皮细胞(SEC)损伤的详细过程、方式及机制,为冷保存再灌注损伤的保护研究开辟新的途径.方法 雄性SD大鼠随机分为假手术组(n=6)、UW 1 h肝移植组(n:48)、Uw 12 h肝移植组(n=48).大鼠原位肝移植采用双袖套法,分别于术后不同时相点采取血液及组织标本,检测血清丙氨酸氨基转移酶(ALT)及透明质酸(HA)水平;HE染色观察肝脏病理学变化;TUNEL法检测凋亡,免疫组化法检测Bcl-2及Cleaved Caspase-3的表达状况.结果 UW 1 h、UW 12 h组肝移植后血清ALT、HA均较假手术组明显升高(P<0.05),UW 12 h组又明显高于Uw 1 h组(P<0.05).UW 12 h组ALT水平于术后6 h达高峰,而HA水平却在术后1 h、24 h呈双峰表现.Uw 12 h组首先出现SEC的凋亡继而出现肝细胞的坏死,且UW 12 h组细胞凋亡指数(apoptosis index,AI)明显高于UW 1 h组(P<0.01).两组大鼠SEC的AI均于术后6 h达高峰,与血中ALT的高峰时相点一致.肝移植术后Bcl-2表达明显减弱(P相似文献   

大鼠肝窦内皮细胞分离、培养及其生物学特性的初步研究

目的　建立大鼠肝窦内皮细胞 (SEC)的原代分离、培养方法 ,并研究其生物学特性。方法　胶原酶灌注结合Percoll密度梯度离心加选择性贴壁的方法分离SEC ;用光镜、扫描电镜观察培养SEC的形态学变化及超微结构 ;用Ⅷ因子和CD14免疫细胞化学染色及RECA 1单抗间接免疫荧光法观察SEC表面分子的表达。结果　分离培养的SEC得率为 (2 .0 6± 0 .35 )× 10 7/只大鼠 ,活力≥ 92 % ,纯度达 90 % ;光镜下细胞形态典型 ,SEM下可观察到特征性的窗孔结构 ;Ⅷ因子染色阴性而CD14染色阳性 ,RECA 1单抗间接免疫荧光染色阳性。结论　分离培养的SEC细胞得率、活力及纯度较高 ,形态典型且具有一般细胞所没有的窗孔结构及表面标志 ,为其功能和作用机制的深入研究奠定了基础。     

肝脏低温保存时肝窦内皮细胞损伤的研究

利用低温灌注技术，电镜技术和生化检测技术，对低温保存人肝脏肝窦内皮细胞的损伤进行了研究。结果显示：低温保存时不仅肝实质细胞受到损伤，而且肝窦内皮细胞发生更严重的损伤，随着保存时间延长，嘌呤核苷磷酸化酶（ＰＮＰ）逐渐升高。秀射电镜和扫描电镜显示：人肝脏低温保存后，肝窦内皮细胞可出现变性肿胀，肝窦内大泡形成，随着保存延长，肝窦内皮细胞出现变性坏死导致肝窦阻塞。肝窦内皮细胞损伤后可导致肝脏微循环系统连续     

肝细胞对肝窦内皮细胞生长的支持作用

目的 探讨肝细胞在大鼠肝窦内皮细胞(hepatic sinus endothelial cell,HSEC)生长过程中的作用,并建立一种新的HSEC原代培养方法.方法 Ⅳ型胶原酶分离肝细胞,运用Pereoll建立的梯度密度离心以及选择性贴壁纯化HSEC,舍肝细胞条件培养液(HC-CM)的RPMI-1640培养液培养HSEC.结果 平均每只大鼠可获取2.55×107个HSEC,平均活力98%,培养24 h后纯度约91%.HC-CM有效刺激HSEC生长,促进细胞内DNA合成.HSEC体外生长保持良好的形态,维持5～6 d,扫描电镜下可见典型的窗孔样结构.结论 本实验方法能提供高活力的HSEC,肝细胞条件培养液内舍有多种营养因子支持HSEC生长.     

丹参对肝脏保存再灌注中肝窦内皮细胞损伤的影响

我们采用离体大鼠肝脏保存再灌注模型 ,观察肝脏保存再灌注中肝窦内皮细胞结构和功能的改变 ,并探讨丹参的保护作用。一、材料与方法1.肝脏保存液及灌注液成分 :ＢｅｌｚｅｒＵＷ保存液购自美国Ｄｕｐｏｎｔ ｐｈａｒｍａ公司。自制ＫＨ平衡灌注液 :含氯化钠 118ｍｍｏｌ/Ｌ、氯化钾 4.74ｍｍｏｌ/Ｌ、氯化钙 1.2 4ｍｍｏｌ/Ｌ、硫酸镁1.18ｍｍｏｌ/Ｌ、硫酸钾 1.19ｍｍｏｌ/Ｌ、碳酸氢钠 2 4.9ｍｍｏｌ/Ｌ、葡萄糖 5ｍｍｏｌ/Ｌ ,加蒸馏水至 10 0 0ｍｌ,ｐＨ调为 7.4。2 .动物模型及分组 :健康Ｗｉｓｔａｒ雄性大鼠 5 4只 ,体重 2 0 0～ 2 …     

常温肝缺血再灌注肝血窦内皮细胞损伤

目的 探讨肝脏常温 因再灌注稆肝血窦内皮细胞的结构变化及其在再灌注损伤中的作用。方法 将４４只大鼠在常温下分别阻断人肝血流２０、４０、６０和９０ｍｉｎ,然后再开放血流２ｈ,制备成缺血再灌注模型,对肝血窦内皮细胞进行扫描和透射电镜观察,正常对照组大鼠５只。结果 肝血流阻断２０、４０ｍｉｎ时内皮细胞受损;血流开放后２ｈ内皮变化可恢复。肝血流肝断６０、９０ｍｉｎ后内皮细胞出现损伤,使部分内皮缺损,上直接     

Endothelial Cell Retention on a Viscoelastic Nanocomposite Vascular Conduit Is Improved by Exposure to Shear Stress Preconditioning Prior to Physiological Flow

In this study, endothelial cell (EC)‐seeded nanocomposite grafts were preconditioned with 1–2 dynes/cm² in vitro to establish whether low shear stress resulted in improved cell adherence prior to physiological shear stress (15 dynes/cm²). Alamar blue cell viability was assessed. Polymerase chain reaction was conducted for glyceraldehyde‐3‐phosphate dehydrogenase, transforming growth factor beta‐1 (TGFβ‐1), vascular endothelial growth factor receptor‐1 (VEGFR‐1), platelet EC adhesion molecule‐1, and vascular endothelial growth factor receptor‐2 (VEGFR‐2). The Alamar blue results demonstrated improved cellular retention following preconditioning (P < 0.001). VEGFR‐2 and TGFβ‐1 expression was up‐regulated, and VEGFR‐1 down‐regulated following preconditioning. This investigation confirms previous findings regarding the potential benefits of preconditioning, and demonstrates that these benefits can be applied to ECs seeded on the nanocomposite employed. It also demonstrates further the suitability and potential of nanocomposite for future use in tissue‐engineered cardiovascular devices.     

In Vitro and Computational Thrombosis on Artificial Surfaces With Shear Stress

Implantable devices in direct contact with flowing blood are associated with the risk of thromboembolic events. This study addresses the need to improve our understanding of the thrombosis mechanism and to identify areas on artificial surfaces susceptible to thrombus deposition. Thrombus deposits on artificial blood step transitions are quantified experimentally and compared with shear stress and shear rate distributions using computational fluid dynamics (CFD) models. Larger steps, and negative (expanding) steps result in larger thrombus deposits. Fitting CFD results to experimental deposit locations reveals a specific shear stress threshold of 0.41 Pa or a shear rate threshold of 54 s^?1 using a shear thinning blood viscosity model. Thrombosis will occur below this threshold, which is specific to solvent‐polished polycarbonate surfaces under in vitro coagulation conditions with activated clotting time levels of 200–220 s. The experimental and computational models are valuable tools for thrombosis prediction and assessment that may be used before proceeding to clinical trials and to better understand existing clinical problems with thrombosis.     

血管内皮细胞在动脉粥样硬化中的损伤机理

目的探讨血管内皮细胞在动脉粥样硬化形成过程中的损伤机理。方法复习相关文献。对有关进展进行总结分析。结果各种致病因素造成细胞因子生成增多，激活了控制细胞粘附分子表达的核因子-κB，进而使细胞粘附分子表达增强，促进单核细胞一血管内皮细胞为主的粘附形成增多，释放大量炎性介质(氧自由基及蛋白酶等)，不仅直接损伤血管内皮细胞，并可以通过免疫机理使大量单核细胞及中性粒细胞与血管内皮细胞粘附结合，进一步损伤血管内皮细胞。同时，受损的血管内皮细胞由于膜结构的改变引起抗动脉抗体的产生以致补体系统被激活而加重了血管内皮细胞的损伤，也促进了动脉粥样硬化的发生和发展。结论正确认识血管内皮细胞在动脉粥样硬化发生、发展过程中受损机理，对于动脉粥样硬化的防治具有重要意义。     

不同血清浓度对淋巴管内皮细胞培养的影响

目的探讨不同浓度的血清在人淋巴管内皮细胞培养中的作用,得出最优血清浓度,优化淋巴管内皮细胞(Lymphatic endothelial cells,LECs)的培养方案。方法通过免疫磁珠法获得人LECs,将不同浓度(0%、2.5%、5%、7.5%、10%)的胎牛血清加入EGM-2培养液中,培养LECs,并通过免疫荧光、RT-PCR、流式分析、成管试验、吞脂试验等方法,鉴定LECs特异性标记及功能。结果通过免疫磁珠法获得的人LECs表达特异性指征和功能。不同浓度的血清培养液对人LECs的吞脂功能无明显影响,无血清组丧失淋巴管成管能力,7.5%血清组成管能力和增殖能力最强。结论人LECs培养过程中,血清在细胞增殖和功能保持方面具有重要作用,最适宜的血清浓度是7.5%,此浓度血清培养的细胞其增殖能力以及功能都是最优的。     

Self‐reported Racial Discrimination and Endothelial Reactivity to Acute Stress in Women

This study investigated the effect of self‐reported racial discrimination on endothelial responses to acute laboratory mental stress among post‐menopausal women. One‐hundred thirteen women (n = 94 self‐identified as White and n = 19 self‐identified as racial/ethnic minority), 43% with type 2 diabetes, reported lifetime experiences of racial/ethnic discrimination. Repeated assessments of flow‐mediated dilation were performed at baseline, immediately after 5 min of mental arithmetic and at 20‐min recovery. Both White and racial/ethnic minority women reported lifetime discrimination, with rates significantly higher among minorities. Self‐reported lifetime discrimination was associated with attenuated flow‐mediated dilation at recovery. Confounding variables, including clinical characteristics, mood, personality traits, other life stressors and general distress, did not better account for the effect of racial discrimination. Neither race/ethnicity nor diabetes status moderated the effect. The perceived stressfulness of the mental arithmetic was not associated with the endothelial response. In conclusion, self‐reported lifetime discrimination is associated with attenuated endothelial recovery from acute mental stress. Elucidating the effects of discrimination and the biological mechanisms through which it affects the vasculature may suggest interventions to improve health. Copyright © 2012 John Wiley & Sons, Ltd.     

甘氨酸对鼠肝热缺血再灌注后肝窦内皮细胞损伤的保护作用

目的　探讨甘氨酸对大鼠肝脏热缺血再灌注后肝窦内皮细胞损伤的保护作用及其机理。方法　取健康雄性SD大鼠 72只 ,制备成鼠肝热缺血再灌注模型 ,而后随机分成正常对照组、缺血再灌注组、士的宁 +甘氨酸治疗组和甘氨酸治疗组 ,每组各 18只。分别于再灌注后 1、3、2 4h检测血浆中内皮素 (ET)、透明质酸 (HA)、肿瘤坏死因子 α (TNF α)、谷丙转氨酶 (ALT)及肝组织中超氧化物歧化酶 (SOD)含量的变化 ,并在光镜下观察肝窦内皮细胞的病理改变。结果　在再灌注后的不同时点 ,甘氨酸治疗组中ET、HA、TNF α及ALT含量较缺血再灌注组显著降低 (P<0 .0 1或P<0 .0 5 ) ,SOD值相应升高 ,同时光镜下肝窦内皮细胞的病理变化明显改善 ,士的宁可部分拮抗甘氨酸的作用。结论甘氨酸对鼠肝热缺血再灌注后肝窦内皮细胞的损伤具有保护作用。推测这种作用可能与肝窦内皮细胞及枯否细胞膜上的甘氨酸受体密切相关。     

The Effect of Shear Stress on the Size,Structure, and Function of Human von Willebrand Factor

Clinical outcomes from ventricular assist devices (VADs) have improved significantly during recent decades, but bleeding episodes remain a common complication of long‐term VAD usage. Greater understanding of the effect of the shear stress in the VAD on platelet aggregation, which is influenced by the functional activity of high molecular weight (HMW) von Willebrand factor (vWF), could provide insight into these bleeding complications. However, because VAD shear rates are difficult to assess, there is a need for a model that enables controlled shear rates to first establish the relationship between shear rates and vWF damage. Secondly, if such a dependency exists, then it is relevant to establish a rapid and quantitative assay that can be used routinely for the safety assessment of new VADs in development. Therefore, the purpose of this study was to exert vWF to controlled levels of shear using a rheometer, and flow cytometry was used to investigate the shear‐dependent effect on the functional activity of vWF. Human platelet‐poor plasma (PPP) was subjected to different shear rate levels ranging from 0 to 8000/s for a period of 6 h using a rheometer. A simple and rapid flow cytometric assay was used to determine platelet aggregation in the presence of ristocetin cofactor as a readout for vWF activity. Platelet aggregates were visualized by confocal microscopy. Multimers of vWF were detected using gel electrophoresis and immunoblotting. The longer PPP was exposed to high shear, the greater the loss of HMW vWF multimers, and the lower the functional activity of vWF for platelet aggregation. Confocal microscopy revealed for the first time that platelet aggregates were smaller and more dispersed in postsheared PPP compared with nonsheared PPP. The loss of HMW vWF in postsheared PPP was demonstrated by immunoblotting. Smaller vWF platelet aggregates formed in response to shear stress might be a cause of bleeding in patients implanted with VADs. The methodological approaches used herein could be useful in the design of safer VADs and other blood handling devices. In particular, we have demonstrated a correlation between the loss of HMW vWF, analyzed by immunoblotting, with platelet aggregation, assessed by flow cytometry. This suggests that flow cytometry could replace conventional immunoblotting as a simple and rapid routine test for HMW vWF loss during in vitro testing of devices.     

睾酮诱导人脐带静脉内皮细胞ERK1/2磷酸化的研究

目的:观察生理浓度睾酮(3×10-8mol/L)对人脐带静脉内皮细胞(HUVEC)细胞外信号调节激酶ERK1/2磷酸化水平的影响。方法:将体外培养的HUVEC分为5个时间段睾酮组(睾酮作用后0、5、15、30、60min)和雄激素受体拮抗剂氟他胺预处理组,Western印迹测定睾酮作用于HUVEC后ERK1/2的活化程度。结果:睾酮可激活HUVEC ERK1/2,30min后达到高峰,而雄激素受体拮抗剂氟他胺可抑制睾酮对ERK1/2的激活。结论:生理浓度睾酮可通过雄激素受体促进细胞外信号调节激酶ERK1/2磷酸化,且在作用30min后达到最大效应。