SDF-1／CXCR4的研究进展

基质细胞衍生因子-1(stromal cell—derived factorl,SDF-1)是α趋化因子家族的—个新成员,其受体CX—CR4广泛地表达在许多组织和器官上。SDF—1／CXCR4与造血干／祖细胞的动员和归巢密切相关,并且是白血病细胞迁移、播散的重要因子。近来研究发现,SDF—1／CXCR4参与调节造血干／祖细胞的增殖及其白血病细胞抗凋亡过程;能够通过免疫调节发挥抗感染、抗肿瘤作用。因此,对SDF—1／CXCR4的深入研究将有助于阐述造血机制和肿瘤细胞生长机制,为临床移植和抗肿瘤治疗提供新的途径。     

E-Selectin Mediated Adhesion and Migration of Endothelial Colony Forming Cells Is Enhanced by SDF-1α/CXCR4

Objective

Endothelial-colony forming cells (ECFCs) can be readily expanded from human umbilical cord blood and can facilitate repair of endothelial injury. E-selectin and SDF-1α are produced following endothelial injury and can regulate endothelial progenitor homing. Mechanisms of vascular repair specific to the mode of injury have not been well described in homogenous cell populations such as ECFCs and are needed for development of more effective vascular repair strategies.

Methods and Results

Lipopolysaccharide (LPS)-induced endotoxic injury to mature human umbilical vein endothelial cells (HUVEC) was compared with hypoxic and radiation injury. E-selectin expression in HUVEC cells is markedly increased (208-fold) following LPS-induced injury and facilitates increased ECFC adhesion and migration function in vitro. SDF-1α expression remains unchanged in LPS-treated HUVEC cells but increases more than 2 fold in fibroblasts undergoing similar endotoxic injury. SDF-1α induces expression of E-selectin ligands on ECFCs and facilitates greater E-selectin-mediated adhesion and migration of ECFCs in a CXCR4-dependent manner. Induction of E-selectin expression in HUVECs following hypoxic or radiation injury is negligible, however, while SDF-1α is increased markedly following hypoxia, highlighting injury-specific synergism between mediators of vascular repair.

Conclusion

E-selectin mediates adhesion and migration of ECFCs following endotoxic endothelial injury. SDF-1α augments E-selectin mediated ECFC adhesion and migration in a CXCR4-dependent manner.     

趋化因子SDF-1及受体CXCR4研究进展

趋化因子(chemokine)是一类一级结构相似,以对白细胞等多种细胞具有趋化定向运动作用为特征的小分子蛋白。功能研究表明,趋化因子在胚胎发育、血管生成、炎症、肿瘤、艾滋病等机体多种生理和病理过程中发挥重要作用,部分趋化因子的衍生物或抑制物具有潜在的临床应用前景。不久的将来,趋化因子及其受体可能成为疾病治疗的分子靶点。     

SDF-1/CXCR4轴在胃癌中的研究进展

尽管近年来胃癌的诊断与治疗取得了长足发展,但胃癌致死率仍高居全球各类肿瘤的第三位。炎性趋化因子家族包含约50位成员,参与增殖、分化、迁移等多项细胞功能的调节。炎性趋化因子受体CXCR4及其配体基质细胞衍生因子1(SDF-1)在多种肿瘤中表达。SDF-1在胃癌中高表达,SDF-1/CXCR4轴促进胃癌细胞增长、增殖与转移,在胃癌发生发展过程中发挥重要作用。本文着重论述SDF-1/CXCR4轴在胃癌发生发展中的研究进展。     

The SDF-1/CXCR4 axis induces epithelial–mesenchymal transition in hepatocellular carcinoma

Targeted immunotherapy has become a popular research topic in cancer. The development and metastasis of cervical carcinoma are closely related to epidermal growth factor (EGF) and EGF-1 receptor (EGFR). We successfully constructed a single-chain human anti-EGFR antibody (scFv) and truncated protamine (tP) fusion protein (scFV/tP) expression vector using overlap extension PCR. Enzyme-linked immunosorbent assay and gel shift assay showed that the fusion protein retained the DNA and antigen-binding activity of the original antibody. Using the non-viral scFv/tP vector as a delivery tool, small interfering RNA (siRNA) of the human wings apart-like gene (hWAPL) was effectively transfected into cervical cancer HeLa cells. The hWAPL mRNA expression levels were reduced by 97.23 % in contrast with control cells, and the proliferation capability declined by 66.71 %, indicating significant inhibition. The present results provide a novel strategy for targeted gene therapy and siRNA therapy of EGFR-positive cervical cancers.     

SDF-1和及其受体CXCR4的结构与功能

近年基质细胞衍生因子 1(SDF 1)及其受体CXCR4的构效关系与相互作用机制研究进展很快 .研究证实 ,SDF 1N末端 (Nt)氨基酸残基是与CXCR4相互作用的关键区域 .SDF 1的 β链与蛋白聚糖 (GAG)作用而调节SDF 1的功能 ,C端α螺旋有助于维持SDF 1的活性构象 ;CXCR4Nt、ECL2和 (或 )ECL3对于SDF 1和HIVgp12 0对CXCR4的识别和激活都很重要 ,但在识别序列上存在部分交叉重叠 .SDF 1 CXCR4与肿瘤转移密切相关 ,本文还就SDF 1与CXCR4在肿瘤治疗方面的应用进行了讨论 .     

SDF-1／CXCR4在造血干细胞动员相关研究新进展

造血干细胞移植（HSCT）已成为治疗血液系统疾病、实体瘤、代谢性和严重自身免疫性等疾病主要方法之一。GCSF介导的动员是一个复杂的、多步骤的过程,而基质细胞衍生因子（SDF-1）及其受体CXCR4在造血干细胞的的动员及归巢中发挥着重要的作用。近年来．以SDF01／CXCR4为动员靶点研制出的CXCR4拮抗剂——AMD3100,经临床实验证明它是一种安全有效的新的动员剂。     

SDF-1/CXCR4轴在缺氧缺血性脑损伤中的研究进展

干细胞在许多组织器官显示巨大的细胞分化潜能,其治疗缺血缺氧性疾病成为当前研究的热点。已知局部缺血可诱导干细胞的动员,并能感受组织损伤而定向迁移到损伤区并进行分化。具有趋化因子受体4（CXC chemokine receptor 4,CXCR4）的干细胞迁移到高表达间质细胞来源的因子-1（stromal cell-derived factor-1,SDF-1）的组织区域,这种细胞的迁移运动能被CXCR4拈抗剂所阻断或通过CXCR4的过表达增强迁移的运动。SDF-1-CXCR4轴是体内各种类型的干细胞迁移及细胞在骨髓的滞留和归巢中的重要调节物质。本文就缺氧缺血性脑损伤的骨髓间质干细胞（bone marrow stromal cell,BMSC）治疗,SDF- 1-CXCR4轴在MSCs动员和损伤、修复中的作用作一综述。     

SDF-1/CXCR4轴在骨再生修复中的研究进展

基质细胞衍生因子-1(stromal cell-derived factor-1,SDF-1)及其受体CXCR4构成SDF-1/CXCR4轴系统具有许多重要的生物学特性和功能。近年来随着该领域的研究不断深入,越来越多的发现表明,SDF-1/CXCR4轴系统在组织损伤及修复中起着重要作用,其在骨组织再生修复中的作用也日益受到关注。该文主要对SDF-1/CXCR4轴系统的生物学特性及其在骨再生修复中的作用进行综述。