CXCR4在胶质瘤细胞中的表达及对迁移的影响

目的检测趋化因子受体CXCR4在胶质瘤细胞的表达。建立侵袭迁移模型,分析CXCR4在CXCL12作用下对U251细胞迁移的影响机制。方法间接免疫荧光法检测CXCR4在U251的表达。流式细胞术(flow cytometry,FCM)检测不同病理级别胶质瘤CXCR4的表达。建立琼脂糖下细胞迁移(Under-agarose cell migration assay)模型,研究U251在不同浓度CXCL12下的侵袭能力。设空白组与实验组,实验组以CXCL12浓度分5组。计算趋化系数(chemotaxis coefficient,cc)。结果 (1) CXCR4表达于U251细胞。(2)Ⅰ、Ⅱ、Ⅲ、Ⅳ级别胶质瘤CXCR4表达率分别为21. 36±2. 70%、26. 39±4. 27%、52. 59±2. 37%、56. 23±1. 24%。四个级别胶质瘤CXCR4的阳性率均有显著差异(P 0. 05)。(3)对照组细胞迁移距离为40. 85±5. 16μm,实验组细胞迁移距离分别为49±2. 26μm、105. 6±3. 82μm、165. 3±3. 89μm、245. 4±5. 94μm、161. 45±3. 18μm。因子浓度为200～500 ng/ml时与阴性组相比细胞发生明显迁移(P 0. 05)。结论 (1)胶质瘤细胞U251表达CXCR4。(2)胶质瘤的病理级别越高CXCR4的阳性率越大。(3)成功建立了胶质瘤细胞琼脂糖下侵袭模型,为研究肿瘤细胞迁移提供新的方法; CXCL12对胶质瘤有明显的趋化作用,肿瘤细胞顺因子浓度梯度定向迁移。     

趋化因子CXCL12和其受体CXCR4在神经系统肿瘤中的研究进展

趋化因子CXCLl2和其受体CXCR4广泛存在于正常组织中,存神经系统胚胎发育等方面发挥重要的生理作用.CXCLl2和CXCR4与神经系统肿瘤细胞的转移、增殖、信号系统激活密切相关.基于体外试验及动物模型的研究提示,特异性拮抗CXCLl2和CXCR4,有町能成为神经系统肿瘤靶向治疗的有效途径.     

脑胶质瘤趋化因子受体CXCR4表达的临床意义

目的探讨CXCR4表达与人脑胶质瘤分级、血管生成和预后的相关性。方法采用免疫组织化学SABC法检测48例胶质瘤组织中CXCR4、CD34的表达。结果32例CXCR4呈阳性表达，占66．7％；不同病理分级（WHO Ⅰ～Ⅳ级）各组CXCR4表达有显著性差异（χ^2=4．875，P〈0．05）；生存期3年以上组与3年以下组间有显著性差异（χ^2=7．356，P〈0．05）；CXCR4的表达与微血管密度（MVD）密切相关（r=0．674，P〈0．01）。结论CXCR4表达异常在胶质瘤发生中具有重要作用；CXCR4与肿瘤的病理分级、病人预后密切相关．并可能参与胶质瘤血管内皮细胞的生成．     

CXCR4在胶质瘤诱导血管生成中的作用

目的 研究CXCR4在人脑胶质瘤中的表达及其与肿瘤恶性程度、微血管密度(MVD)之间的关系,进一步探讨CXCR4在胶质瘤血管生成中的作用及CXCR4作为抗肿瘤靶点的可能性.方法 收集河南省人民医院神经外科自2009年9月至2011年9月手术切除的人脑胶质瘤标本41例,其中低度恶性胶质瘤(Ⅰ～Ⅱ级)18例,高度恶性胶质瘤(Ⅲ～IV级)23例.另外取行内减压术的脑外伤患者的新鲜脑组织10例作为对照.免疫组织化学染色检测标本CXCR4和CD34的表达,实时荧光定量PCR检测标本CXCR4mRNA的表达.结果 免疫组化染色结果显示对照组CXCR4表达阴性,脑胶质瘤组织CXCR4表达阳性28例(68.29％),脑胶质瘤组织MVD的表达高于对照组,且高度恶性胶质瘤组CXCR4表达阳性率、MVD的表达均高于低度恶性胶质瘤组,差异有统计学意义(P＜0.05);CXCR4表达阳性组MVD(42.51±6.99)明显高于CXCR4表达阴性组(25.98±4.99),差异有统计学意义(P＜0.05);高度恶性胶质瘤组CXCR4mRNA的表达量(5.19±1.43)高于低度恶性胶质瘤组(2.28±0.71),差异有统计学意义(P＜0.05).结论 CXCR4在胶质瘤血管生成中发挥重要的作用,有可能成为胶质瘤抗血管生成治疗的新靶点.     

CXCR4 signaling in central nervous system regeneration: friend or foe?

The knockout of the chemokine C-X-C motif chemokine receptor 4(CXCR4)in growthstimulated retinal ganglion cells(RGCs)has a multiplicative effect on optic nerve regeneration.C-X-C motif chemokine ligand 12(CXCL12),the exclusive ligand of CXCR4.     

CXCL12/CXCR4生物学轴对骨髓间充质干细胞修复脊髓损伤的影响☆

背景：研究发现不同途径移植骨髓间充质干细胞均能向脊髓损伤部位迁移,进而发挥治疗作用。 目的：探讨CXCL12/CXCR4生物学轴对骨髓间充质干细胞趋向脊髓损伤部位迁移的作用。 方法：采用改进的脊椎骨破坏法制备脊髓损伤模型。假手术组只打开皮肤,不损伤脊髓且不作任何干预;模型组于造模后第2天采用腰骶鞘内注射5 μL生理盐水;细胞移植组于造模后第2天采用腰骶鞘内移植5 μL骨髓间充质干细胞。 结果与结论：①荧光显微镜下可见,横切的脊髓损伤局部有大量的标记细胞聚集,而在损伤部位远端1 cm处,仅见少量的标记骨髓间充质干细胞。②骨髓间充质干细胞表达中等水平的趋化因子CXCL12,其特异性结合受体CXCR4也有低水平表达。③脊髓损伤7 d后,局部CXCL12表达增强,主要集中在脊髓损伤部位的皮质区域,而在损伤部位1 cm以外的脊髓组织未见大量表达的CXCL12。CXCR4蛋白表达没有明显的时间效应。④检测CXCL12 mRNA的转录水平发现细胞移植组的CXCR4转录水平明显高于假手术组和模型组,损伤后14 d脊髓损伤局部CXCL12的转录水平最强,21 d时降低,CXCL12的局部转录水平明显高于远端。⑤脊髓损伤部位也表达趋化因子CXCR4,但其表达水平没有时程差异。损伤局部的CXCR4转录水平略高于远端,但差异无显著性意义。说明CXCL12/CXCR4生物学轴参与骨髓间充质干细胞向脊髓损伤区域迁移。     

趋化因子受体4在人脑胶质瘤中的表达及临床意义

目的探索趋化因子受体4(CXCR4)在人脑胶质瘤中的表达,与临床特征间的关系及其在预后判断中的作用。方法对中国脑胶质瘤基因组图谱计划(CGGA)中305例mRNA芯片数据中进行CXCR4表达分析;在REMBRANDT mRNA芯片数据库、GSE16011 mRNA芯片数据库及TCGA RNA测序数据库中验证CXCR4在胶质瘤中的表达特征。Kaplan-Meier生存曲线及Cox分析评价CXCR4在胶质瘤患者预后判断中的作用,Gene ontology(GO)分析CXCR4正相关表达基因功能。结果 CXCR4表达量随胶质瘤级别增高而升高,CXCR4高表达患者的预后生存期短。CXCR4生物学功能可能与机体免疫、炎症、创伤应答,细胞激活及黏附有关。结论 CXCR4可作为胶质瘤患者预后判断的指标及潜在的治疗靶点。     

CXCR4表达上调对U251细胞增殖、侵袭、迁移的影响

目的 探讨CXC趋化因子-4受体（CXCR4）表达上调对U251细胞增殖、侵袭及迁移能力的影响及其作用机制。方法 构建携带CXCR4基因的质粒,采用电转染法将携带CXCR4基因的质粒整合到胶质瘤U251细胞的基因组中,然后将细胞分为空白对照组、阴性对照组和CXCR4上调组,分别从mRNA水平和蛋白水平检测CXCR4及其他相关基因的表达;MTT试验检测细胞增殖能力的改变;划痕试验检测细胞的迁移能力;Transwell侵袭试验检测细胞侵袭性的变化。结果 与空白对照组和阴性对照组相比,CXCR4上调组U251细胞CXCR4在mRNA和蛋白水平上表达都增强,细胞增殖、侵袭和迁移能力均显著增强;而空白对照组和阴性对照组之间并无明显变化。结论 CXCR4在胶质瘤的增殖、侵袭、迁移行为中发挥着重要的作用,可以被视为胶质瘤治疗的靶向基因。     

SDF-1/CXCR4生物学轴与颅内转移瘤相关性的研究进展

趋化因SDF-1（CXCL12）与其特异性受体CXCR4构成的CXCL12/CXCR4生物学轴在神经系统转移瘤细胞的生长、迁移中起到重要的作用,对这一特殊生物学轴的研究可以为肿瘤转移的防治提供新的思路。本文将对CXCL12/CXCR4生物学轴与脑转移瘤发生发展关系的研究现状,做一综述。     

A role for CXCR4 signaling in survival and migration of neural and oligodendrocyte precursors

Oligodendrocyte development is controlled by a number of survival and migratory factors. The present study shows that signaling of CXCR4 receptor by the chemokine CXCL12 regulates survival and migration of neural precursors (NP) as well as oligodendrocyte progenitors (OP). CXCR4 is expressed by E14 striatal NP and OP generated by neurospheres. In CXCR4-defective mice, the number of NP in neurosphere outgrowth was twofold less than in wild-type (WT) mice; NP radial cell migration was also decreased. In contrast, the addition of CXCL12 to WT NP increased radial migration from the sphere in a dose-dependent manner with a maximal response at 200 nM. When oligodendrocytes differentiated in neurosphere outgrowth, CXCR4 was downregulated. OP isolated from newborn brain coexpressed CXCR4 with platelet-derived growth factor receptor-alpha (PDGFR alpha) or chondroitin sulfate proteoglycan; receptor expression also decreased during differentiation in vitro. Neonatal OP showed a peak migratory response to 20 nM of CXCL12 in chemotactic chambers, a migration inhibited by a CXCR4 antagonist and anti-CXCL12 antibody. In the embryonic spinal cord, the number of OP-expressing PDGFR alpha was reduced more than twofold in CXCR4-defective mice compared with WT and the ratio of ventral to dorsal OP was significantly increased. This indicates a defect in OP survival and their dorsal migration from the ventral cord region, probably because CXCR4(-/-) OP are unable to respond to CXCL12 made by vascular endothelia and the pia mater. We propose that CXCR4 signaling regulate survival and outward chemotactic migration of OP during embryonic and postnatal CNS development.     

诺帝对CXCR4介导的人恶性胶质瘤细胞钙流和白细胞介素8分泌的抑制作用

目的 观测诺帝(Nordy)对人恶性胶质瘤细胞系U87细胞趋化因子受体CXCR4活化后钙流变化及白细胞介素8(IL-8)产生的影响.方法 采用Fluo-4/AM标记钙离子、激光共聚焦显微术观测CXCR4被其配体间质细胞衍生因子-1α(SDF-1α)活化后U87细胞钙流的变化,并通过酶联免疫吸附试验(ELISA)检测细胞培养上清中IL-8的含量;以CXCR4抑制剂AMD3100为对照,用自行合成的化合物诺帝顸处理U87细胞,再用SDF-1α刺激,观测二者对CXCR4活化后引起的钙流变化和IL-8分泌的影响.结果 25～100ng/ml SDF-1α可不同程度地引起U87细胞胞内钙流增加和IL-8分泌量增多,与对照组(无SDF-1α刺激)相比均有显著统计学意义(P<0.05);用1～10μmol/LAMD3100或25～100μmol/L诺帝预处理细胞,再用SDF-1α刺激,上述效应受到抑制.结论 诺帝可抑制CXCR4活化引起的钙流和IL-8产生,这可能是其抗胶质瘤血管生成机制之一.     

CXCR4 signaling mediates morphine-induced tactile hyperalgesia

Morphine and related compounds are the first line of therapy in the treatment of moderate to severe pain. Over time, individuals taking opioids can develop an increasing sensitivity to noxious stimuli, even evolving into a painful response to previously non-noxious stimuli (opioid-induced hyperalgesia; OIH). The mechanism underlying OIH is not well understood although complex intracellular neural mechanisms, including opioid receptor desensitization and down-regulation, are believed to be major mechanisms underlying OIH. However, OIH may also be associated with changes in gene expression. A growing body of evidence suggests that cellular exposure to mu agonists upregulate chemokines/receptors and recent work from our laboratory implicates chemokine upregulation in a variety of neuropathic pain behaviors. Here we characterized the degree to which chemokines/receptors signaling is increased in primary afferent neurons of the dorsal root ganglion (DRG) following chronic morphine sulfate treatment and correlated these changes with tactile hyperalgesic behavior in rodents. We demonstrate that mRNA expression of the chemokine, stromal-derived factor-1 (SDF1/CXCL12) is upregulated following morphine treatment in sensory neurons of the rat. The release of SDF1 was found to be constitutive when compared with the activity dependent release of the C-C chemokine, monocyte chemoattractant protein-1 (MCP1/CCL2) in a line of F11 neuroblastoma-sensory neuron hybrid cells. We further determined that there is pronounced CXCR4 expression in satellite glial cells and following morphine treatment, increased functional CXCR4 expression in sensory neurons of the DRG. Moreover, intraperitoneal administration of the specific CXCR4 antagonist, AMD3100, completely reversed OIH in the rat. Taken together; the data suggest that opioid-induced SDF1/CXCR4 signaling is central to the development of long lasting OIH and that receptor antagonists represent a promising novel approach to the management of the side effects associated with the use of opioids for chronic pain management.     

CXCR4活化促进人恶性胶质瘤细胞分泌血管生成因子

目的观测CXCR4活化对人恶性胶质瘤细胞系U87中血管内皮生长因子（VEGF）、白细胞介素-8（IL-8）基因表达及蛋白分泌的影响。方法采用间接免疫荧光标记观测CXCR4在U87细胞中的表达和定位；用间质细胞衍生因子-1α（SDF-1α）激活CXCR4，通过酶联免疫吸附试验（ELISA）检测U87细胞培养上清中VEGF、IL-8蛋白的含量，用逆转录聚合酶链反应（RT-PCR）检测二者mRNA的表达。结果CXCR4表达于U87细胞的胞膜和胞质，经活化后可增加VEGF、IL-8mRNA的表达和蛋白分泌量。结论人恶性胶质瘤细胞中CXCR4活化后能够促进血管生成因子VEGF和IL-8的产生。     

Chemokine receptor CXCR4 signaling modulates the growth factor-induced cell cycle of self-renewing and multipotent neural progenitor cells

CXC chemokine receptor CXCR4 is expressed in vitro in both human and rodent adult neural progenitor cells (NPCs). It has been suggested that the CXCL12-CXCR4 axis potentially enhances the proliferation of NPCs. However, whether CXCR4 is expressed in the neural stem cells (NSCs), a subset of self-renewing and multipotent NPCs, and whether CXCR4 signaling is directly required for their proliferation are not clear. In this study, we report that CXCR4 is expressed in a subpopulation of NPCs in the early embryonic ventricular zone. In studies of a CXCR4(eGFP) bacterial artificial chromosomal (BAC) transgenic mouse line, we further isolated NPCs from E12.5 transgenic telencephalon and GFP(+) cells demonstrated self-renewal and multipotency in neurosphere assays in vitro. Consistent with these observations, we enriched GFP(+)/CXCR4(+) cells by fluorescence activated cell sorting (FACS) with either CXCR4 antibody 12G5 or GFP. Furthermore, we observed that CXCL12 alone did not activate the self-renewal of NPCs or increase the proliferation of NPCs that are induced by bFGF/EGF. However, we found that blocking CXCR4 receptor with antagonist AMD3100 impaired the bFGF/EGF-induced expansion of GFP(+) NPCs through modulating their cell cycling. In addition, AMD3100 treatment of pregnant mice reduced the generation of neurospheres from E12.5 embryos. Our data suggest that CXCR4 is a potential cell surface marker for early embryonic NSCs and modulates growth-factor signaling.