E-选择素表达与小鼠胎肝发育及造血功能*★

背景：E-选择素作为一种细胞黏附分子在细胞间选择性识别黏附、调节白细胞归巢及渗出和肿瘤细胞转移等方面的作用已有研究报道，但胚肝发育过程中E-选择素的定性定位研究、与胚肝造血功能的关系至今未见报道。 目的：观察小鼠肝脏发育过程中E-选择素的表达与肝细胞、肝血窦内皮形态分化及胎肝造血作用的关系。 方法：取胚胎11.5(E11.5)至出生后15.5 d(P15.5)的小鼠胚胎或胎肝，常规制作石蜡切片，行苏木精-伊红染色及免疫组织化学检测。光学显微镜下观察胎肝的组织结构变化及细胞形态；免疫组织化学方法检测发育各期肝组织内E-选择素表达。 结果与结论：E11.5肝始祖细胞形成团索样结构，其间有窦样间隙，内有散在的造血干细胞；E12.5 d肝始祖细胞开始增殖分化，其后，随着小鼠胎肝的不断发育，肝细胞数量及体积增大，核质比减小，至出生时形成肝小叶结构；窦样间隙由少到多，由宽变窄，窦壁内皮细胞从少量、不连续逐步增殖形成完整的内皮；造血细胞于E12.5开始造血，E13.5~E15.5达高峰，之后造血功能均逐步减弱。E-选择素表达于E11.5~E15.5胎肝的内皮细胞，定位于内皮细胞的胞膜，随内皮细胞发育及肝细胞分化成熟，E-选择素表达渐消失。提示E12.5~E15.5为小鼠胎肝各细胞发育分化的关键时期，E-选择素表达于此阶段的血窦内皮，与肝脏造血及肝细胞分化有密切关系。     

选择素与缺血性脑卒中

选择素属于细胞间黏附分子家族，包括P-选择素（CD62P）、E-选择素（CD62E）、L-选择素（CD62L）三个成员。选择素家族始动了白细胞血小板和内皮细胞间的相互作用，参与了血栓形成和炎症反应，在缺血性脑卒中的早期阶段发挥了重要作用。文章对选择素的结构、分布及在缺血性脑卒中中的作用和机制作了简要介绍。     

脑缺血-再灌注损伤白细胞渗出和L-选择素表达及人工合成E-选择素的干预作用

目的：研究人工合成E-选择素对脑缺血再灌注后白细胞渗出和L-选择素表达的影响。方法：应用线栓法建立局灶性脑缺血再灌注大鼠模型，采用流式细胞术检测脑缺血再灌注后白细胞渗出和L-选择素表达。结果：L-选择素在脑缺血再灌注2h后已经表达，再灌注6h达高峰；在再灌注12h后CD45表达逐渐增加。应用人工合成E-选择素后，L-选择素表达在各时间点均下降（P〈0．05）；在再灌注12.24%1148h时间点CD45的表达明显低于对照组（P〈0．05）。结论：人工合成E-选择素能够明显抑制L-选择素的表达，使白细胞的渗出明显减少，对大鼠脑缺血再灌注损伤起到保护作用。     

细胞黏附分子血浆E-选择素水平与下肢深静脉血栓形成

背景：研究表明，深静脉内白细胞参与的炎症反应在深静脉血栓形成中起了很重要的作用，而E-选择素的主要作用是介导炎症过程中白细胞与血管内皮细胞黏附的起始过程。 目的：拟观察细胞黏附分子E-选择素水平与下肢深静脉血栓形成的关系。 设计、时间及地点：配对设计，直线相关分析，于2007-09/12在重庆医科大学附属第一医院血管外科及重庆医科大学临床检验诊断学实验室完成。 对象：选择发病在3 d 内或病情加重的27例下肢深静脉血栓形成患者，男16例，女11例，平均年龄(57±15)岁。 方法：入院时采集第1次血液标本，经过溶栓，抗凝治疗72 h 后采集第2次血液标本。用ELISA法测定血浆中E-选择素的质量浓度，同时测定第1次采血样本的血小板计数及其凝血功能，包括部分激活凝血活酶时间、凝血酶原时间、血浆纤维蛋白原。 主要观察指标：治疗前后患者E-选择素的水平，治疗前凝血功能、血小板计数及与E-选择素相关性分析。 结果：27例下肢深静脉血栓形成患者在治疗期间均未发生急性肺栓塞，1例行Forgart导管取栓术，其余26例患者72 h 后，15例患者临床症状明显好转，11例临床症状未见好转。①下肢深静脉血栓形成患者经过溶栓、抗凝治疗临床缓解者血浆E-选择素水平明显下降(P=0.001)，而临床未缓解者血浆E-选择素水平则呈上升表现(P=0.003)。②下肢深静脉血栓形成患者治疗前E-选择素水平与血小板计数无相关性(r=-0.113，P=0.576)，与纤维蛋白原含量无相关性(r=-0.050，P=0.802)，与部分激活凝血活酶时间无相关性(r=-0.046，P=0.822)，与凝血酶原时间亦无相关性(r=-0.080，P=0.690)。 结论：血浆E-选择素水平与深静脉血栓形成症状严重程度呈正相关性。     

E-选择素基因多态性与缺血性卒中的关系的Meta分析

目的：探讨E-选择素基因S128R多态性与缺血性卒中的关系。 资料来源：计算机检索PubMed,Elseiver, Ovid和中国期刊全文数据库、万方数据库,检索时限为1998-01/2010-12。 资料选择：纳入E-选择素基因多态性与缺血性卒中关系的病例-对照研究,研究对象基因型分布符合Hardy-Weinberg遗传平衡。纳入文献由两名作者进行质量评价,经严格筛选后,采用RVEMAN 5.1统计软件对纳入文献进行Meta分析,并进一步进行异质性检验及偏倚评估。 结局评价指标：E-选择素基因S128R位点的基因型及等位基因分布。 结果：共纳入6篇病例-对照研究,各研究的基因型和等位基因频数之间无异质性,未见明显发表偏倚。Meta分析结果显示,与对照组比较,缺血性卒中组(AC+CC）/AA基因型的OR=1.93, 95%CI为1.55~2.41, Z=5.80, P<0.00001;等位基因频数C/A的OR=1.80, 95%CI为1.47~2.22, Z=5.59, P<0.00001。对研究中国人群的4项研究进行meta分析发现(AC+CC）/AA基因型的OR=2.36, 95%CI为1.68~3.31, Z=4.99, P<0.00001;等位基因频数C/A的OR=2.25, 95%CI为1.63~3.12, Z值=4.80, P<0.00001。 结论：E-选择素基因S128R多态性与缺血性卒中相关,AC、CC基因型和C等位基因是缺血性卒中的易感因素。     

人工合成E-选择素对大鼠脑缺血再灌注损伤保护作用的实验研究

目的：探讨人工合成E-选择素对大鼠脑缺血再灌注损伤的保护作用机制。方法：雄性SD大鼠90只，随机分为3组：①假手术组；②缺血再灌注组；③人工合成B选择素治疗组（E-选择素治疗组）。大鼠局灶性脑缺血再灌注模型中B选择素治疗组建立模型前5min从股静脉注入人工合成E-选择素10mg·kg^-1。在不同时间点（缺血再灌注后2、6、12、24、48和72h）用ELISA法测定血浆IL-1β、TNF-α含量。分别在光镜和电镜下观察大鼠脑缺血再灌注区的病理形态改变。结果：缺血再灌注组与假手术组相比，血浆IL-1β、TNF-α含量明显增加（P〈0．05），E-选择素治疗组血浆IL-1β、TNF-α水平均降低（P〈0．05）。光镜和电镜下观察见缺血再灌注组额顶叶皮质和基底节区神经细胞呈缺血性改变，应用人工合成E-选择素后上述区域缺血性改变可明显减轻。结论：应用人工合成E-选择素能减轻大鼠脑缺血再灌注损伤后炎症细胞因子IL-1β和TNF-α的表达，减轻神经细胞缺血性改变，对大鼠脑缺血再灌注损伤具有保护作用。     

脑梗死患者可溶性E-和P-选择素水平变化及意义

目的:探讨E-和P-选择素与脑梗死的关系。方法应用ELISA方法测定30例脑梗死患者,25例脑出血患者及28例正常人的sE-和sP-选择素血清水平。结果 急性期脑便死患者sE-和sP-选择素血清水平明显高于脑出血患者及正常人。急性期脑梗死患者sE-和sP-选择素水平分别与WBC、N％、IL-6水平呈正相关关系,sP-选择素水平还与TNF水平呈正相关关系。结论sE-和sP-选择素血清水平增高反映脑便死急性期E-和P-选择素可能在TNF和IL-6的刺激下,参与脑梗死损伤过程。     

大鼠脑缺血再灌注后MMP-9的表达及人工合成E-选择素的干预作用

目的：研究肿瘤坏死因子-α（TNF-α）和基质金属蛋白酶-9（MMP-9）参与大鼠脑缺血再灌注损伤的机制及人工合成E-选择素保护作用的机制。方法：健康SD大鼠,随机分为手术组、假手术组和治疗组。手术组建立大鼠局灶性脑缺血再灌注损伤模型;治疗组术前从股静脉注射人工合成E-选择素;假手术组仅将线栓插到颈外动脉、颈内动脉分叉处,其余步骤同手术组。免疫组化检测脑组织中TNF-α和MMP-9的表达,RT-PCR检测MMP-9mRNA的表达。结果：手术组TNF-α、MMP-9和MMP-9mRNA表达与假手术组比较均有明显升高（P〈0．05）;治疗组TNF-α、MMP-9和MMP-9mRNA表达水平比手术组明显下降（P〈0．05）。相关分析表明,MMP-9mRNA分别与TNF-α和MMP-9的表达呈正相关。结论：大鼠脑缺血再灌注后TNF-α能够在转录水平诱导MMP-9的表达。人工合成E-选择素降低大鼠脑缺血再灌注后缺血脑组织MMP-9表达的机制可能是抑制TNF-α对MMP-9mRNA合成的诱导,从而降低了MMP-9的表达。     

人工合成E-选择素对脑血管病作用的最新研究进展

脑血管疾病是一类严重威胁人类健康的常见疾病。多种炎症因子参与某些脑血管疾病的发生和发展。人工合成E-选择素具有抑制某些炎症因子表达的作用。本文就人工合成E-选择素对脑血管病作用的新进展做一综述。     

中国人群E-选择素基因S128R多态性与脑梗死关系的Meta分析

目的 探讨中国人群E-选择素基因S128R多态性与脑梗死的关系.方法 在PubMed,Elseiver,Ovid和CNKI、万方数据库检索以中国人群为研究对象的病例对照研究.采用RVEMAN 4.3统计软件对其结果进行分析.结果 共纳入4篇以中国人群为研究对象的病例对照研究.各研究的基因型和等位基因频数结果之间无异质性.未见明显发表偏倚.4个研究合并后,AA/(AC+CC)基因型的OR=0.41,95%,CI为0.28～0.58,Z=4.88,P＜0.00001;等位基因频数A/C的OR=0.43,95%,CI为0.30～0.60,Z=4.77,P＜0.00001.汉族人群3个研究合并后,AA/(AC+CC)基因型的OR=0.35,95%,CI为0.22～0.57,Z=4.28,P＜0.00001;等位基因频数A/C的OR=0.49,95%,CI为0.32～0.75,Z=3.29,P=0.001.中国汉族和壮族基因型和等位基因分布差异无统计学意义.结论 中国人群E-选择素基因S128R多态性与脑梗死相关,AA基因型和A等位基因是中国人群脑梗死的低危因素.     

Soluble E-selectin in cardiovascular disease and its risk factors. A review of the literature

The initial steps in the pathogenesis of atherosclerosis involve changes to the vascular endothelium, which produces numerous substances involved in the regulation and maintenance of vascular integrity and the homeostasis of the coagulation/fibrinolysis system. A further change in endothelial physiology is an increase in the surface expression of cell adhesion molecules, such as E-selectin, which regulate adhesive interactions between certain blood cells and endothelium. As E-selectin is only expressed on activated endothelium, it therefore provides an opportunity to study pathophysiological aspects of this cell in cardiovascular and other disease. However, a soluble form of E selectin (i.e. sE-selectin) can be found in the plasma. This review will focus on sE-selectin, and its potential role in the pathogenesis of cardiovascular disease as raised levels have been found in hypertension, diabetes and hyperlipidemia, although its association in established atherosclerosis disease and its value as a prognostic factor is more controversial.     

Mucosal tolerization to E-selectin protects against memory dysfunction and white matter damage in a vascular cognitive impairment model.

Vascular cognitive impairment (VCI) is the second most prevalent type of dementia in the world. The white matter damage that characterizes the common subcortical ischemic form of VCI can be modeled by ligating both common carotid arteries in the Wistar rat to induce protracted cerebral hypoperfusion. In this model, we find that repetitive intranasal administration of recombinant E-selectin to induce mucosal tolerance and to target immunomodulation to activating blood vessels potently suppresses both white matter (and possibly gray matter) damage and markers of vessel activation (tumor necrosis factor and E-selectin); it also preserves behavioral function in T-maze spontaneous alternation, T-maze spatial discrimination memory retention, and object recognition tests. Immunomodulation may be an effective novel strategy to prevent progression of VCI.     

The E-selectin S128R polymorphism is not a risk factor for coronary artery disease in patients with diabetes mellitus type 2

AIM/HYPOTHESIS: E-selectin is thought to play a key role in the early stages of vascular disease by facilitating the attachment of leukocytes to the endothelium. Recently, a polymorphism in the E-selectin gene (S128R) has been associated with higher E-selectin levels in patients with diabetes mellitus and with premature coronary artery disease. The impact of the S128R polymorphism on the development of diabetic coronary artery disease has not been investigated yet. PATIENTS AND METHODS: A total of 254 patients recruited from the Division of Cardiology, University of Vienna with diabetes mellitus type 2 was assessed for the E-selectin S128R polymorphism by a novel mutagenic separated PCR, allowing fast and reliable genotyping without restriction enzyme digest. Ninety-five patients had a history of myocardial infarction, 90 were admitted with stable coronary artery disease whereas in 69 the presence of CAD could be excluded. RESULTS: Of all 254 individuals tested, 197 (77.6%) exhibited wildtype E-selectin 128S genotype, 54 (21.3%) were heterozygous S128R and 3 (1.1%) were homozygous for the 128R allele. In all groups the genotype frequencies did not differ significantly. No associations were found between E-selectin genotype and coronary artery disease or myocardial infarction. CONCLUSION/INTERPRETATION: In subjects suffering from diabetes mellitus type 2 the E-selectin S128R polymorphism is not associated with coronary artery disease nor with an increased risk for myocardial infarction. Thus, screening for this polymorphism is not indicated for risk assessment of CAD in patients with diabetes mellitus.     

Adhesion molecule expression and regulation on cells of the central nervous system.

Cellular adhesion molecules were initially defined as cell surface structures mediating cell-cell and cell-extracellular matrix (ECM) interactions. Adhesion molecules involved in immune responses have been classified into three families according to their structure: selectins, immunoglobulin (Ig) superfamily, and integrins. It has been well documented that adhesion molecules of these family members (E-selectin, ICAM-1, and VCAM-1) are expressed on brain microvessel endothelial cells in active lesions of multiple sclerosis (MS) brain. In addition, accumulating data show that glial cells can express some of these adhesion molecules upon activation: astrocytes can express ICAM-1, VCAM-1, and E-selectin, and microglia express ICAM-1 and VCAM-1. In vitro studies show that these adhesion molecules are actively regulated by several cytokines which have relevance to MS or experimental autoimmune encephalomyelitis (EAE). In addition, soluble forms of adhesion molecules have been found in the serum and cerebrospinal fluid (CSF) of MS patients, and may be useful diagnostically. Experimental therapy of EAE using antibodies against several adhesion molecules clearly shows that adhesion molecules are critical for the pathogenesis of EAE. Thus far, the function of adhesion molecule expression on brain endothelial and glial cells has not been clearly elucidated. Studies on the possible role of adhesion molecules on brain endothelial and glial cells will be helpful in understanding their involvement in immune responses in the central nervous system (CNS).     

Circulating,soluble adhesion proteins in cerebrospinal fluid and serum of patients with multiple sclerosis: Correlation with clinical activity

Soluble adhesion protein intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule (E-selectin) were measured in serum and cerebrospinal fluid (CSF) of patients with relapsing-remitting multiple sclerosis (RRMS) in remission and in exacerbation, as well as patients with chronic progressive MS, stable MS, and in patients with other neurological and inflammatory diseases (ONDs). Serum ICAM-1 and E-selectin were significantly elevated in patients with MS over those with ONDs and controls. CSF VCAM-1 and E-selectin were found to be elevated over control and disease control samples. No increase in CSF ICAM-1 was observed. Results were analyzed longitudinally and by MS category. In paired CSF and serum samples from patients in exacerbation, elevated VCAM-1 correlated with increased serum VCAM-1 in 5 of 7 patients. Elevated CSF E-selectin did not correlate with elevations in serum E-selectin.     

A561C polymorphism of E-selectin is associated with ischemic cerebrovascular disease in the Japanese population without diabetes mellitus and hypercholesterolemia

E-selectin, which is a member of the selectin superfamily of adhesion molecules, contributes to the leukocyte-endothelial cell attachments and is involved in the pathogenesis of thrombovascular diseases as a consequence. We investigated the A561C mutation in the E-selectin gene in 235 Japanese patients with ischemic cerebrovascular disease (CVD) and 301 age- and sex-matched healthy controls. Excluding the subjects with diabetes mellitus and hypercholesterolemia, the AC genotype frequencies of patients with ischemic CVD were higher than those of controls: 12.7% vs. 5.8% (P=0.04). Our results show that E-selectin gene polymorphisms represent an increased risk for ischemic CVD in the Japanese population without diabetes mellitus and hypercholesterolemia.