移植物转染血红素氧合酶-1基因抑制慢性移植物血管病

目的探讨移植物转染血红素氧合酶-1（HO-1）基因对慢性移植物血管病的影响。方法克隆HO-1基因，并构建含有HO-1基因的重组腺病毒载体（Ad-HO-1），实验分为4组：A组为同系移植对照组，供、受者均为Lewis大鼠，无特殊处理；B组为同种移植对照组，Lewis大鼠接受未经处理的BN大鼠胸主动脉移植；C组为同种移植空载体对照组，Lewis大鼠接受以空载体（不含HO-1基因）处理的BN大鼠的胸主动脉移植；D组为同种移植实验组，Lewis大鼠接受转染HO-1基因的BN大鼠的胸主动脉移植。于移植后60d取移植动脉，进行组织形态学观察，测量内膜厚度；免疫组化和逆转录聚合酶链反应检测HO-1在移植动脉中的表达。结果A组移植动脉形态正常；B组、C组移植动脉呈移植物血管病表现，血管内膜显著增厚，D组移植动脉呈内膜炎改变，内膜厚度与B组、C组相比，差异有统计学意义（P〈0．01）。免疫组化及RT-PCR检测显示，与A组、B组和C组相比，D组移植动脉可以检测到HO-1基因及其蛋白表达。结论在移植血管中预先转染HO-1基因，能明显缓解移植动脉的纤维化进程以及内膜的增生，对慢性排斥反应所致的移植物血管病具有抑制作用。     

染料木黄酮对大鼠移植动脉血管平滑肌细胞的影响

目的研究染料木黄酮(Gen)对大鼠移植动脉血管平滑肌细胞的影响。方法以BN大鼠为供者,Lewis大鼠为受者,建立腹主动脉移植模型,将受者随机分为3组。实验组(n=8):受者术后腹腔注射Gen 20 mg·kg~(-1)·d~(-1)×60 d;对照1组(n=8):受者术后腹腔注射溶剂二甲基亚砜0.5 ml×60 d;对照2组(n=6):受者术后不给予任何处理。腹主动脉移植后60 d取移植血管进行组织学观察,测量血管内膜厚度;免疫组织化学染色检测血管平滑肌细胞的增殖和迁移情况;酶联免疫(ELISA)法检测血清中血管内皮生长因子(VEGF)、γ-干扰素(INF-γ)的变化。结果实验组与两个对照组比较,内膜增厚不明显且巨噬细胞浸润减少;血管平滑肌细胞增殖和迁移减少(P均<0.01);两个对照组血清中VEGF、INF-γ表达显著高于实验组(P<0.01)。结论染料木黄酮在预防和治疗移植动脉硬化的过程中,对移植动脉血管平滑肌细胞的增殖和迁移有抑制作用,其机理可能与影响VEGF等的表达有关。     

沙利度胺对大鼠慢性移植物血管病的保护作用

目的探讨沙利度胺对大鼠慢性移植物血管病的保护作用。方法实验分为4组：同种移植对照组,供、受者均为Lewis大鼠,无特殊处理;异种移植对照组,Lewis大鼠接受Brown-Norway（BN）大鼠腹主动脉移植（BN-Lewis）;沙利度胺小剂量组（50mg·kg-1·d-1,BN-Lewis）;沙利度胺大剂量组（100mg·kg-1·d-1,BN-Lewis）。于移植后60d取移植动脉,分别进行组织病理学观察、测量内膜厚度,免疫组织化学法和蛋白质印迹法检测TNF-α及上皮细胞增殖细胞核抗原（PCNA）在移植动脉中的表达。结果同种移植对照组移植动脉形态正常;异种移植对照组移植动脉呈移植物血管病表现,血管内膜增厚;沙利度胺小剂量及大剂量组移植动脉呈内膜炎改变,内膜厚度比异种移植对照组减小（P〈0．05）。与异种移植对照组相比,沙利度胺小剂量组和大剂量组移植动脉TNF-α及PCNA蛋白表达量降低（均P〈0．05）。结论沙利度胺能降低移植动脉TNF-α及PCNA蛋白的表达,缓解移植动脉的纤维化进程以及内膜增生,对慢性排斥反应所致的移植物血管病具有抑制作用。     

受体细胞参与移植动脉内膜增生的研究

目的研究大鼠移植动脉新生内膜细胞Sty基因的表达，探讨受体细胞在移植动脉内膜增生中的作用。方法建立大鼠腹主动脉移植模型，分为4组：雌雄同系移植组、雌性异系移植组、雄性异系移植组、雌雄异系移植组。移植术后10周时，取移植动脉标本，进行病理组织学观察，测量其内膜厚度和中膜厚度，分析移植动脉内膜增生情况；采用显微切割技术收集新生内膜细胞，用PCR方法检测Sry基因的表达。分析新生内膜细胞与受体细胞的关系。结果异系移植组移植动脉内膜显著增生，动脉壁内膜厚度及内膜／中膜厚度比均显著高于同系移植组（P〈0．01）；而同性或异性异系移植组之间差异无统计学意义（P〉0．05）。PCR分析显示，雄性异系移植组和雌雄异系移植组在242bp处均有1条特异性扩增条带，而雌性异系移植组则无相应的核酸扩增条带。结论受体细胞作为移植物血管新生内膜细胞的来源，参与移植动脉内膜增生及移植物动脉硬化。     

应用吡格列酮抑制大鼠血管移植物慢性病变

目的 研究吡格列酮对血管移植物慢性病变的影响,并探讨其作用机理.方法 制备大鼠腹主动脉移植模型.实验组以Wistar大鼠为供者,SD大鼠为受者,进行腹主动脉移植,术后采用吡格列酮(0.04 g/kg)灌胃8周;同种移植对照组以Wistar大鼠为供者,SD大鼠为受者,进行腹主动脉移植.术后采用牛理盐水灌胃8周;同系移植对照组的供、受者均为SD大鼠,术后采用生理盐水灌胃8周.移植后第8周,取移植腹主动脉段,行HE染色,显微镜F观察组织形态学变化,测量内膜厚度与中膜厚度的比值;采用免疫组织化学法测定移植动脉绀织中细胞问粘附分子-1(ICAM-1)的表达;采用双抗体夹心酶联免疫吸附试验检测血清血小板衍生生长因子(PDGF)浓度.结果 移植后第8周,同系移植对照组的血管内膜无明显变化,同种移植对照组和实验组移植血管组织均呈现出典型的移植相关血管硬化,内膜呈弥漫性向心性显著增生,管腔狭窄,新生内膜见较多血管平滑肌细胞增生,大量成纤维细胞增生,内膜可见少量单核细胞浸润;中膜变薄,内弹力纤维有断裂;外膜见大量单个核细胞,同种移植对照组的病理改变较实验组更加明显.同种移植对照组内膜厚度/中膜厚度比值为1.4140±0.2232,实验组为0.4010±0.0910,二者比较,差异有统计学意义(P＜0.01).同种移植对照组ICAM-1阳性细胞数为(26.114±1.493)个,实验组为(8.943±1.061)个,二者比较,差异有统计学意义(P＜0.01).同种移植对照组的血清PDGF含量为(1023±27)pg/ml,实验组为(265±100)pg/ml,二者比较,差异有统计学意义(P＜0.01).结论 吡格列酮能够延缓移植动脉慢性血管病变的发展,这种作用可能与局部ICAM-1表达下调、血清PDGF浓度下降有关.     

反义细胞外信号调节激酶对移植物血管的保护作用

目的探讨反义细胞外信号调节激酶（ERK1／2）基因治疗对移植物血管的保护作用及可能的保护机制。方法建立BN至Lewis大鼠的腹主动脉移植模型。反义ERK1／2治疗组移植前取供者动脉血管段给予经脂质体包装的反义ERK1／2基因转染；腹主动脉移植术后1个月内受者每日从尾静脉或阴茎背静脉注入经脂质体包装的反义ERK1／2寡核苷酸100μl。对照组移植未经任何处理的血管段，移植后也无特殊处理。移植术后60d取移植段主动脉进行组织病理学观察内膜和胶原纤维变化；免疫组织化学法观察移植段血管ERK1／2基因的表达和CD4^＋、CD8^＋T淋巴细胞的浸润情况；ELISA法检测血清中细胞间粘附分子（ICAM-1）的变化。结果移植术后60d，对照组的移植动脉呈慢性移植物血管病表现，血管内膜显著增厚，移植血管中ERK1／2基因高表达，CD4^＋、CD8^＋T淋巴细胞大量浸润；反义ERK1／2基因治疗组移植动脉呈血管内膜炎改变，ERK1／2基因表达不明显，内膜有少量CD4^＋、CD8^＋T淋巴细胞；对照组ICAM-1表达显著高于反义ERK1／2治疗组（P〈0．05）。结论反义ERK1／2基因治疗对移植物血管具有保护作用，可以减缓慢性移植物血管病的发生，这种保护机制可能和减少ICAM-1的表达以及减少移植血管T淋巴细胞的浸润有关。     

分化生长因子-8对大鼠移植腹主动脉肌纤维化的作用及其机制

目的探讨分化生长因子(GDF)-8对移植大鼠腹主动脉肌纤维化的抑制作用。方法建立雄性Wistar大鼠至雄性SD大鼠腹主动脉原位移植模型,实验动物随机分为两组:延长冷缺血组(PCI)和对照组,测定术后7、14、21、28 d血管内膜厚度,逆转录-聚合酶链反应(RT-PCR)检测移植血管GDF-8的表达,免疫组织化学(IHC)检测Smad4的表达。结果 PCI组内膜14 d开始增厚,28 d至(381．952±44．334)μm,对照组为(56．898±17．543)μm,差异有统计学意义(P<0．05), 术后PCI组GDF-8 mRNA为对照组的3．6％-33.8％,Smad4蛋白表达高于对照组。结论 GDF-8 在移植动脉肌纤维化过程中发挥重要作用,延长冷缺血时间可下调GDF-8的表达而加速肌纤维化进程。     

冬虫夏草提取物抑制大鼠移植物血管病的实验研究

目的 探讨冬虫夏草提取物抑制大鼠移植动脉硬化的效果及其机制.方法 制备大鼠腹主动脉移植模型,分为4组进行实验:同系对照组供、受者均为Lewis大鼠,生理盐水灌胃60d;同种对照组,以Brown-Norway大鼠(BN大鼠)为供者,Lewis大鼠为受者,生理盐水灌胃60d;低剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(1.5 g·kg-1·d-1)灌胃60 d;高剂量实验组,以BN大鼠为供者,Lewis大鼠为受者,以冬虫夏草提取物(3.0g·kg-1·d-1)灌胃60d.于移植后60 d取移植动脉,HE染色,进行病理学观察;免疫组织化学和蛋白质印迹法检测血管内皮生长因子(VEGF)和血小板衍生生长因子BB(PDGF-BB)在移植动脉中的表达.酶联免疫吸附试验检测受鼠血清中VEGF和PDGF- BB含量.结果 同系对照组移植动脉形态正常;同种对照组移植动脉呈移植物血管病表现,血管内膜显著增厚;2个实验组移植动脉呈内膜炎症改变,内膜厚度与同种对照组相比,差异有统计学意义(P＜0.05).同种对照组移植动脉中VEGF和PDGF-BB的表达高于同系对照组(P＜0.05);2个实验组移植动脉中VEGF和PDGF-BB的表达低于同种对照组(P＜0.05).同系对照组受鼠血清中几乎无VEGF和PDGF-BB;同种对照组血清中VEGF和PDGF-BB浓度高于同系对照组(P＜0.05);和同种对照组相比较,2个实验组血清VEGF和PDGF-BB浓度较低(P＜0.05).结论 冬虫夏草提取物能明显抑制动脉内膜的增生,可缓解慢性排斥反应所致的移植动脉硬化,这种保护作用可能与下调VEGF和PDGF-BB表达有关.     

大鼠颈静脉分支-颈动脉间置模型新生内膜细胞来源研究

目的探讨大鼠颈静脉分支-颈动脉间置模型新生内膜细胞来源。方法建立SD大鼠颈静脉分支-颈动脉间置模型,分别于术后1、3、7、14和28d取静脉移植血管,定量分析新生内膜厚度,并进行α-SM—actin和CD34免疫组织化学分析。结果新生内膜增生在28d时最明显,血管吻合部位狭窄最严重,增生厚度近端（65．2±4．6）μm,远端（64．7±5．3）μm,中段（63．5±5．6）μm。新生内膜细胞主要来源于内皮细胞、相邻动脉血管平滑肌细胞或循环祖细胞,以新生内膜腔面为著。结论静脉移植血管新生内膜细胞主要来源于静脉移植血管本身内皮细胞、相邻动脉血管平滑肌细胞或循环祖细胞,提示可于血管吻合完成后进行局部干预或术后尽早全身用药,以防止移植血管狭窄。     

经外膜缓释雷帕霉素抑制兔同种异体移植血管内膜增生的研究

目的：探讨雷帕霉素抑制血管移植后再狭窄的作用机制.方法：健康雄性新西兰大耳白兔36只,随机选取其中18只切取腹主动脉,经20%甲醛浸泡48 h去除抗原活性.另18只动物随机分为3组,腹主动脉移植去抗原同种异体腹主动脉后给予不同处理.A组：血管移植后不予处理;B组：在移植血管外膜及吻合口周围涂抹20% pluronic F-127多聚凝胶0.5 ml;C组：在相同部位涂抹含0.5 mg雷帕霉素的20% pluronic F-127多聚凝胶0.5 ml.术后4周获取移植血管,HE染色观察移植血管内膜增生情况,计算机图像分析系统测量移植血管内膜厚度,免疫组化SP法检测移植血管α-actin、PCNA和p27kip1的表达.结果：术后4周,A、B组较C组内膜增生明显（P＜0.05）.增生的血管内膜均可见类似于血管平滑肌的α-actin阳性表达.各组移植血管增生的内膜均可见不同程度的PCNA、p27kip1阳性表达.C组α-actin和PCNA的表达较A、B组明显降低（P＜0.05）,而p27kip1的表达较A、B组明显增多（P＜0.05）.结论：对20% pluronic F-127多聚凝胶携带雷帕霉素涂抹移植血管外膜可有效抑制移植血管平滑肌细胞增殖.雷帕霉素抑制移植血管再狭窄的机制与其上调移植血管组织中p27kip1的表达而使细胞增殖周期受抑有关.     

SDF-1 plays a key role in the repairing and remodeling process on rat allo-orthotopic abdominal aorta grafts

BACKGROUND: Our previous study demonstrated that prolonged cold preservation promoted neointima formation and remodeling but delayed the subsequent arteriosclerosis of rat abdominal aorta grafts. The mechanisms of this phenomenon remain obscure. In this study, we investigated whether stromal cell derived factor-1 (SDF-1) could play a role in recruiting stem cells to repair and remodel the damaged intima of abdominal aorta grafts. METHODS: Male Spague-Dawley rats received abdominal aorta grafts from male Wistar rats. Hematoxylin and eosin staining was performed to assess the structure of graft aortas by measuring the neointimal thickness. Immunohistochemical staining detected SDF-1 expression. RT-PCR demonstrated the expression of CXCR4, the only known natural receptor of SDF-1 expression on stem cells. RESULTS: The neointimal thickness of the SDF-1 antibody-treated group was inconspicuous; a significant relationship existed between the expression of SDF-1 and the neointimal thickness of the grafts. Furthermore, no CXCR4 was detected in normal abdominal aortas, but it was observed in the grafted abdominal aorta. CONCLUSION: Prolonged cold ischemia may delay the graft's arteriosclerosis by selectively chemoattracting stem cells to the damaged intima through SDF-1, the presence of which may predict graft arteriosclerosis and the subsequent development of chronic graft dysfunction (CGD). The SDF-1 antibody slowed the endothelial chimerism by blocking this chemoattration. In addition to mycophenolate mofetil and FK 506, SDF-1 antibody might be a new potential effective strategy to decrease the frequency of CGD.     

SDF-1 plays a key role in chronic allograft nephropathy in rats

OBJECTIVES: Our previous study demonstrated that anti-stromal cell derived factor-1 (SDF-1) antibody delayed graft arteriosclerosis in rat abdominal aortic grafts. In this study, we investigated the mechanisms of SDF-1 on chronic allograft nephropathy (CAN), and whether SDF-1 antibody had protective effect on CAN. METHODS: Male Lewis rats that received left renal grafts from male Fisher 344 rats were randomly divided into three groups: group A only received cyclosporine (CsA; 10 mg x kg(-1) x d(-1)) every day; group B received anti-SDF-1 antibody (8 microg x kg(-1) x d(-1)) + CsA (10 mg x kg(-1) x d(-1)); and group C, an isograft control (Fisher 344 to Fisher 344). All recipient animals were unilaterally right nephrectomized. Group A and B grafts were preserved in 4 degrees C UW solution for 1 hour prolonged cold ischemia. Masson and hematoxylin and eosin staining were performed to evaluate glomerular sclerosis rate (GSR) and Banff score. Serum creatinine (Scr) and blood urea nitrogen (BUN) were determined as well as histologic examinations of the kidneys with immunohistochemistry for SDF-1 and CXCR4, the only known receptor of SDF-1. RESULTS: Compared with group C, ischemia and rejection produced a nine-fold increase in GSR and Banff score, as well as significant increases in Scr and BUN levels in group A. Anti-SDF-1 antibody retarded the increase by downregulating the expression of SDF-1 and CXCR4. Furthermore, there was a significant relationship between the expression of SDF-1 and the mean Banff score. CONCLUSION: Anti-SDF-1 antibody retarded the process of CAN.     

Hepatic Stellate Cells Promote Liver Metastasis of Colon Cancer Cells by the Action of SDF-1/CXCR4 Axis

Background  It has been determined that the chemokine receptor CXCR4 and its ligand stromal cell-derived factor-1 (SDF-1) regulate several key processes in a wide variety of cancers. However, the function and mechanism of the SDF-1/CXCR4 system in the metastasis of colorectal cancer remain controversial. Methods  Immunohistochemistry was performed to examine quantitatively the expression of CXCR4 in 40 human samples of colorectal cancer and liver metastasis. The functions of SDF-1 on HCT116 colon cancer cells were investigated in vitro. We subcutaneously inoculated HCT116 cells with hepatic stellate cells (HSCs) expressing SDF-1. The CXCR4 inhibitor AMD3100 was tested in vitro and in vivo. Results  By quantitatively counting the number of cells, it was shown that there are more CXCR4-positive cells at the metastatic site in the liver compared with the primary sites. We demonstrated the effect of SDF-1 on the invasion and antiapoptosis of HCT116 cells in vitro. In mouse experiment of liver metastasis, intraperitoneal administration of AMD3100 blocked the metastatic potential of HCT116 cells. Furthermore, we found that α-smooth muscle actin (α-SMA)-positive myofibroblasts derived from HSCs, surrounding the liver metastasis foci, secreted SDF-1. The subcutaneous inoculation of HCT116 cells with HSCs promoted the tumor initiation in nude mice, indicating the importance of the direct interaction between these cells in vivo. Conclusion  These results suggest that HSCs play important role in liver metastasis of colon cancer cells by the action of SDF-1/CXCR4 axis and provide preclinical evidence that blockade of the axis is a target for antimetastasis therapy.     

SDF-1-CXCR4/CXCR7信号对脂肪干细胞促血管新生能力的影响

目的 研究SDF-1对ADSCs体外促血管新生能力的影响,并探讨CXCR4、CXCR7在其中的作用。方法 体外培养ADSCs,检测其CXCR4、CXCR7的表达;SDF-1刺激ADSCs,并分别加入CXCR4、CXCR7封闭抗体,检测ADSCs-CM中VEGF、HGF、β-FGF含量,及其对h UVECs微血管形成的影响。结果 成功培养ADSCs;ADSCs体外培养传代过程中CXCR4、CXCR7表达持续下降;SDF-1刺激上调CXCR4、CXCR7表达,并提高ADSCs对血管活性因子的分泌,及促进h UVEC微血管的形成;封闭CXCR4、CXCR7均可显著抑制SDF-1的促进作用。结论 体外环境下,SDF-1可上调ADSCs中CXCR4、CXCR7表达,并通过SDF-1-CXCR4/CXCR7两条通路提高ADSCs的促血管新生能力。     

Skeletal localization and neutralization of the SDF-1(CXCL12)/CXCR4 axis blocks prostate cancer metastasis and growth in osseous sites in vivo.

To delineate the role of SDF-1 and CXCR4 in metastatic prostate cancer (CaP), positive correlations were established between SDF-1 levels and tumor metastasis. Neutralization of CXCR4 limited the number and the growth of intraosseous metastasis in vivo. Together, these in vivo metastasis data provide critical support that SDF-1/CXCR4 plays a role in skeletal metastasis. INTRODUCTION: Previously we determined that the stromal-derived factor-1 (SDF-1)/CXCR4 chemokine axis is activated in prostate cancer (CaP) metastasis to bone. To delineate the role of SDF-1/CXCR4 in CaP, we evaluated SDF-1 levels in a variety of tissues and whether neutralization of SDF-1 prevented metastasis and/or intraosseous growth of CaPs. MATERIALS AND METHODS: SDF-1 levels were established in various mouse tissues by ELISA, immunohistochemistry, and in situ hybridization. To assess the role of SDF-1/CXCR4 in metastasis, bone metastases were established by administering CaP cells into the left cardiac ventricle of nude animals in the presence or absence of neutralizing CXCR4 antibody. The effect of SDF-1 on intraosseous growth of CaP cells was determined using intratibial injections and anti-CXCR4 antibodies and peptides. RESULTS: There was a positive correlation between the levels of SDF-1 and tissues in which metastatic CaP lesions were observed. SDF-1 levels were highest in the pelvis, tibia, femur, liver, and adrenal/kidneys compared with the lungs, tongue, and eye, suggesting a selective effect. SDF-1 staining was generally low or undetectable in the center of the marrow and in the diaphysis. SDF-1 mRNA was localized to the metaphysis of the long bones nearest to the growth plate where intense expression was observed near the endosteal surfaces covered by osteoblastic and lining cells. Antibody to CXCR4 significantly reduced the total metastatic load compared with IgG control-treated animals. Direct intratibial injection of tumor cells followed by neutralizing CXCR4 antibody or a specific peptide that blocks CXCR4 also decreased the size of the tumors compared with controls. CONCLUSIONS: These data provide critical support for a role of SDF-1/CXCR4 in skeletal metastasis. Importantly, these data show that SDF-1/CXCR4 participate in localizing tumors to the bone marrow for prostate cancer.     

SDF-1/CXCR4生物轴对胆囊癌细胞增殖及迁移的影响

目的 研究胆囊腺癌中趋化因子SDF-1及其受体CXCR4的表达情况,探讨其与胆囊腺癌临床病理特点及淋巴转移的关系.方法 采用免疫组化SP法检测41例胆囊腺癌中SDF-1及其受体CXCR4蛋白阳性表达情况,并分析其与临床病理参数的关系.结果 SDF-1在胆囊癌、胆囊炎、胆囊结石组和正常对照组胆囊黏膜中的表达率分别为68.3%(28/41)、6.7%(6/90)和5.0%(1/20),CXCR4的表达率分别为51.2%(21/41)、5.6%(5/90)和5.0%(1/20),SDF-1和CXCR4在胆囊癌与慢性胆囊炎、胆囊结石组胆囊黏膜、正常对照组胆囊黏膜中的阳性率比较,差异均有统计学意义(SDF-1:χ2=64.33,P＜0.001;CXCR4:χ2=42.52,P＜0.001),胆囊癌不同病理组织学分级、Nevin不同分期、组织学不同分化程度、有无淋巴结或远处转移组间的SDF-1和CXCR4的阳性率表达差异均有统计学意义(P均＜0.05),而不同性别、年龄、有无伴发胆囊结石组、肿瘤大小间SDF-1和CXCR4的阳性率表达差异均无统计学意义(P均＞0.05),胆囊癌组织中SDF-1阳性表达率(68.3%)与CX-CR4阳性表达率(51.2%)之间存在显著正相关(r=0.68,P＜0.01).结论 本研究表明,SDF-1/CXCR4生物轴与胆囊癌关系密切,提示可以通过干预SDF-1/CXCR4生物轴来治疗胆囊癌.     

Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 in the formation of postburn hypertrophic scar (HTS)

Recent data support the involvement of stromal cell-derived factor 1 (SDF-1) in the homing of bone marrow-derived stem cells to wound sites during skeletal, myocardial, vascular, lung, and skin wound repair as well as some fibrotic disorders via its receptor CXCR4. In this study, the role of SDF-1/CXCR4 signaling in the formation of hypertrophic scar (HTS) following burn injury and after treatment with systemic interferon α2b (IFNα2b) is investigated. Studies show SDF-1/CXCR4 signaling was up-regulated in burn patients, including SDF-1 level in HTS tissue and serum as well as CD14+ CXCR4+ cells in the peripheral blood mononuclear cells. In vitro, dermal fibroblasts constitutively expressed SDF-1 and deep dermal fibroblasts expressed more SDF-1 than superficial fibroblasts. Lipopolysaccharide increased SDF-1 gene expression in fibroblasts. Also, recombinant SDF-1 and lipopolysaccharide stimulated fibroblast-conditioned medium up-regulated peripheral blood mononuclear cell mobility. In the burn patients with HTS who received subcutaneous IFNα2b treatment, increased SDF-1/CXCR4 signaling was found prior to treatment which was down-regulated after IFNα2b administration, coincident with enhanced remodeling of their HTS. Our results suggest that SDF-1/CXCR4 signaling is involved in the development of HTS by promoting migration of activated CD14+ CXCR4+ cells from the bloodstream to wound sites, where they may differentiate into fibrocyte and myofibroblasts and contribute to the development of HTS.     

Stromal cell-derived factor-1 (SDF-1) recruits osteoclast precursors by inducing chemotaxis, matrix metalloproteinase-9 (MMP-9) activity, and collagen transmigration.

Signals targeting OCs to bone and resorption sites are not well characterized. A chemoattractant receptor (CXCR4), highly expressed in murine OC precursors, mediated their chemokine (SDF-1)-induced chemoattraction, collagen transmigration, and MMP-9 expression. Thus, bone vascular and stromal SDF-1 may direct OC precursors into bone and marrow sites for development and bone resorption. INTRODUCTION: Although chemokines are essential for trafficking and homing of circulating hematopoietic cells under normal and pathological conditions, their potential roles in osteoclast (OC) recruitment or function are generally unknown. CXCR4 and its unique ligand, stromal cell-derived factor-1 (SDF-1), critically control the matrix metalloproteinase (MMP)-dependent targeting of hematopoietic cells into bone and within the marrow microenvironment. Therefore, SDF-1/CXCR4 may regulate OC precursor recruitment to sites for development and activation. METHODS: Chemokine receptor mRNA expression was analyzed during OC formation induced by RANKL in murine RAW 264.7 cells. SDF-1 versus RANKL effects on chemotaxis, transcollagen migration, MMP-9 expression and activity, OC development, and bone resorption were evaluated in RAW cells or RAW-OCs. RESULTS: CXCR4 was highly expressed in RAW cells and downregulated during their RANKL development into bone-resorptive RAW-OCs. SDF-1, but not RANKL, elicited RAW cell chemotaxis. Conversely, RANKL, but not SDF-1, promoted RAW-OC development, TRAP activity, cathepsin K expression, and bone pit resorption, and SDF-1 did not modify these RANKL responses. Both SDF-1 and RANKL increased MMP-9, a matrix-degrading enzyme essential for OC precursor migration into developing bone marrow cavities, and increased transcollagen migration of RAW cells in a MMP-dependent manner. SDF-1 also upregulated MMP-9 in various primary murine OC precursor cells. Because RANKL induced a higher, more sustained expression of MMP-9 in RAW cells than did SDF-1, MMP-9 may have an additional role in mature OCs. Consistent with this, MMP-9 upregulation during RANKL-induced RAW-OC development was necessary for initiation of bone pit resorption. CONCLUSIONS: SDF-1, a chemokine highly expressed by bone vascular endothelial and marrow stromal cells, may be a key signal for the selective attraction of circulating OC precursors into bone and their migration within marrow to appropriate perivascular stromal sites for RANKL differentiation into resorptive OCs. Thus, SDF-1 and RANKL likely serve complementary physiological functions, partly mediated through increases in MMP-9, to coordinate stages of OC precursor recruitment, development, and function.     

基质细胞衍生因子-1对神经干细胞的趋化作用

目的 观察基质细胞衍生因子-1(SDF-1)对神经干细胞(NSCs)迁移的影响.方法 由GFP转基因SD大鼠胚胎脑组织获取NSCs并进行传代培养,免疫细胞化学染色法检测SDF-1特异性受体CXCR4的表达,利用Blind-Well小室体外迁移体系观察不同浓度的SDF-1(0、1、10、50、100、500、1000μg/L)对NSCs定向迁移数量的影响,随后分别使用CXCR4激动剂和阻断剂处理NSCs,再次利用上述方法观察最适浓度SDF-1时NSCs的迁移.结果 成功分离培养得到能够稳定表达GFP的NSCs,且CXCR4在该种NSCs上有表达.体外趋化实验结果表明,SDF-1对NSCs有较强的趋化作用,随着SDF-1浓度的升高,发生迁移的细胞数量也随之增加,并于SDF-1浓度为500μg/L时达到最高峰;CXCR4特异性激动剂和阻断剂分别能够增强和减弱SDF-1对NSCs定向迁移的趋化作用.结论 SDF-1与其特异性受体CXCR4相互作用,能够对NSCs的定向迁移产生靶向性作用.