基质细胞衍生因子-1及其受体CXCR4对结肠癌肝转移潜能的影响

目的 探讨趋化因子基质细胞衍生因子-1(SDF-1)及其受体CXCR4对结肠癌肝转移潜能的影响.方法 采用Western-blot法检测不同结肠癌细胞株中CXCR4蛋白及不同组织中SDF-1蛋白的表达,MTT法检测SDF-1及抗CXCR4单抗对结肠癌细胞HT-29增殖能力的影响,体外趋化实验检测HT-29细胞定向迁移能力的变化.建立裸鼠结肠癌肝转移瘤模型,观察CXCR4特异性拮抗剂AMD3100对裸鼠肝转移率和转移瘤数目的 影响.结果 HT-29细胞表达较高强度的CXCR4蛋白,而肝组织表达高强度的SDF-1蛋白.与对照组相比,SDF-1可以诱导HT-29细胞增殖(0.76±0.11 vs0.38±0.06,P<0.05),抗CXCR4单抗对SDF-1的诱导增殖具有显著的抑制作用(0.42±0.08 vs0.76±0.11,P<0.05);SDF-1可促进HT-29细胞的趋化迁移,抗CXCR4单抗可显著抑制SDF-1诱导下HT-29细胞的迁移能力(104.6±18.3 vs 148.8±26.2,P<0.05).AMD3100治疗组裸鼠结肠癌肝转移率显著低于对照组(40% vs 100%,P<0.05),平均瘤结节数目显著低于对照组(7.8±2.6 vs 22.4±8.6,P<0.05).结论 SDF-1/CXCR4生物轴参与了结肠癌肝转移过程,拮抗CXCR4功能可抑制裸鼠结肠癌肝转移,其机制与抑制CXCR4能够有效阻断结肠癌细胞在SDF-1诱导下的细胞增殖和定向迁移有关.     

SDF-1α G801A Polymorphism Predicts Lymph Node Metastasis in Stage T3 Colorectal Cancer

Background  The SDF-1/CXCR4 axis plays an important role in cancer metastasis. SDF1α genetic polymorphisms, including SDF1α-G801A, have been associated with increased cancer risk and may be predictive of distant metastasis. The present study compared the frequency of 6 SDF1α single-nucleotide polymorphisms (SNPs) in patients with colorectal cancer (CRC) with and without lymph node (LN) metastasis and determined whether fibroblasts with different SDF-1α genotypes influenced cancer cell proliferation and migration. Methods  The study enrolled 424 patients with primary T3 stage CRC, with and without lymph node metastasis, and a median follow-up of 48 months. The polymerase chain reaction-sequence specific primers (PCR-SSP) technique was used to identify polymorphisms. Fibroblasts were harvested from 14 patients with stage II CRC and fibroblast-mediated enhancement of cancer cell proliferation and migration was evaluated. Results  Only the SDF1α-G801A polymorphism was associated with LN metastasis. The frequency of GA/AA genotypes was significantly higher in patients with LN metastasis (54.8%) than in patients without LN metastasis (40.7%). In the latter group, disease-free survival was shorter in patients with the GA/AA genotype (74%) than in patients with the GG genotype (87.6%). In patients with LN metastasis, disease-free survival was similar regardless of genotype. Expression of SDF-1α mRNA in GA/AA fibroblasts was three times that in GG fibroblasts. GA/AA (but not GG) fibroblasts enhanced colon cancer cell (HCT116) proliferation and migration. These effects were blocked by an SDF-1α neutralizing antibody. Conclusions  The SDF1α-G801A polymorphism may increase expression of SDF-1α mRNA and be a predictive marker of lymph node metastasis in colorectal cancer.     

SDF-1/CXCR4信号轴调控骨髓间充质干细胞向哮喘小鼠肺组织的迁移

目的：探讨基质细胞衍生因子-1（SDF-1）/CXCR4轴在外源性骨髓间充质干细胞（MSC）向哮喘模型小鼠肺组织迁移的作用.方法：无菌条件下取GFP转基因小鼠骨髓MSC,体外扩增,鉴定.采用Transwell培养系统,观察0、50、100、150和200 ng/ml SDF-1和CXCR4阻断剂AMD3100对MSC体外定向迁移的影响.取60只雌性BALB/c小鼠,随机分为6组（n=10）：PBS非哮喘组、MSC非哮喘组、PBS哮喘组、MSC哮喘组、SDF-1处理哮喘组、AMD3100处理哮喘组.哮喘组采用哮喘致敏液0.2 ml（含100 μg卵白蛋白）致敏,并使用卵白蛋白雾化吸入激发哮喘.非哮喘组在致敏和激发时均予以PBS处理.MSC处理组于哮喘激发前移植外源性MSC.SDF-1处理哮喘组在MSC移植前气管内注入SDF-1,AMD3100处理哮喘组注入AMD3100预先孵育的MSC.PBS哮喘组注射等量的PBS液.采用Westernablot和RT-PCR方法检测肺组织中SDF-1的表达水平,通过荧光显微镜观察表达GFP的外源性MSC在哮喘小鼠肺组织中的分布情况,比较SDF-1和CXCR4阻断剂AMD3100干预对MSC向肺组织迁移的影响.结果：Transwell实验显示MSC的迁移水平与SDF-1（0~150军ng/ml）成浓度依赖性.与正常小鼠比较,哮喘小鼠肺组织SDF-1表达增强.与MSC非哮喘组比较,MSC哮喘组小鼠肺部有更多MSC聚集.在哮喘肺组织中增加外源性SDF-1能够促进MSC向肺组织迁移.通过AMD3100阻断MSC的CXCR4可以明显减少MSC向肺组织的迁移水平.结论：SDF-1/CXCR4轴参与了MSC迁移到哮喘小鼠肺组织的过程.     

AMD3100抑制胰腺癌细胞增殖和侵袭的体外实验

目的 探讨CXCR4 特异性受体阻滞剂AMD3100 对胰腺癌细胞增殖和侵袭能力的影响及其可能的作用机制.方法 用CCK-8 检测经不同浓度AMD3100 处理后人胰腺癌细胞株SW1990 的增殖.Matrigel 胶铺设的transwell 小室检测经AMD3100 处理后SW1990 的侵袭能力.RT-PCR 法检...     

乳腺癌间质成纤维细胞对MDA-MB-231种植肿瘤生长和转移的影响及其机理探讨

目的通过裸鼠接种方式进行体内实验,观察乳腺癌间质成纤维细胞（CAFs）对种植肿瘤生长和转移的影响,并探讨其作用机理。方法选择MDA．MB．231乳腺癌细胞系细胞（简称MDA）、乳腺癌患者的CAFs和癌旁正常乳腺组织的正常成纤维细胞（NFs）,结合不同的试剂,包括生理盐水（NS）、基质细胞衍生因子-1（SDF-1）配体拈抗剂1,4,8,11．四氮杂环十四烷（AMD3100,简称AMD）,组合成以下6种处理：MDA＋NS、NFs＋NS、MDA＋NFs＋NS、MDA＋NFs＋AMD、MDA＋CAFs＋AMD及MDA＋CAFs＋NS。将36只Bal b／c无胸腺裸小鼠按配伍随机方法分成6组,分别接受上述处理。将细胞悬液接种于裸鼠,接种后饲养46d处死,观察种植肿瘤的大小,有无淋巴结、肺及肝脏转移。采用ELISA法检测6组裸鼠的血浆SDF-1浓度,采用real-timePCR法检测6组裸鼠肿瘤组织中的SDF．1mRNA水平,采用Westernblot法检测6组裸鼠肿瘤组织中SDF-1蛋白的表达水平。结果除NFs＋NS组外,其余5组均有种植肿瘤形成。MDA＋CAFs＋NS组裸鼠的种植肿瘤体积[（9．092±2．662）cm3]、血浆SDF．1浓度[（75．25±16．23）ng／L]、肿瘤组织中SDF-1 mRNA（中位数为14．714）及其蛋白（中位数为0．673）的表达水平均最高,与其他5组比较差异均有统计学意义（P〈0．050）。6组裸鼠的肝和肺组织均未见转移灶。但MDA＋CAFs＋NS组有4只、MDA＋NS组有2只裸鼠存在腋窝淋巴结转移,其他组均未发现腋窝淋巴结转移。结论乳腺癌CAFs对乳腺癌的生长起促进作用,且可促进肿瘤淋巴结的转移;其作用可能是通过乳腺癌CAFs分泌SDF-1,与其特定的受体即趋化因子受体4（cxcR4）结合来实现的。     

AMD3100体外阻断基质细胞衍生因子1/趋化因子受体4信号通路对人关节软骨细胞分泌基质金属蛋白酶3、9、13水平的影响

目的探讨趋化因子受体4(chemokine receptor 4,CXCR4)特异性拮抗剂AMD3100体外阻断基质细胞衍生因子1(stromal cell derived factor 1,SDF-1)/CXCR4信号通路对人关节软骨细胞分泌基质金属蛋白酶(matrixmetalloproteinase,MMP)3、9、13水平的影响,明确AMD3100的作用机制。方法取12例骨关节炎(osteoarthritis,OA)患者144块软骨组织(OA软骨组)和12例创伤性截肢患者144块正常软骨组织(正常软骨组)(Mankin评分均为0或1),根据添加培养液不同,每组再分为A、B、C 3个亚组。A亚组含1 000 nmol/L AMD3100及100 ng/mL SDF-1的DMEM液,B亚组含1 000 nmol/L MAB310及100 ng/mL SDF-1的DMEM液,C亚组含100 ng/mL SDF-1的DMEM液。体外培养2、4 d后,ELISA法测定培养液内MMP-3、9、13含量,RT-PCR检测软骨组织中MMP-3、9、13 mRNA表达。结果 ELISA法及RT-PCR检测示:同组相同时间点A亚组MMP-3、9、13含量及mRNA表达均显著低于B、C亚组(P<0.05)。同一时间点相同亚组OA软骨组MMP-3、9、13含量及mRNA表达均显著高于正常软骨组(P<0.05)。结论 SDF-1通过SDF-1/CXCR4信号通路可诱导人关节软骨中MMP-3、9、13的表达和释放;AMD3100可阻断SDF-1/CXCR4信号通路,使软骨细胞MMP-3、9、13 mRNA表达水平及分泌量降低,但AMD3100不能使退变的OA软骨分泌MMP-3、9、13恢复至正常软骨水平。     

In vivo luminescent imaging of cyclosporin A-mediated cancer progression in rats

BACKGROUND: Immunosuppressed individuals undergoing organ transplantation are at increased risk of recurrences of initial cancers, although how immunosuppressive therapy increases early cancer metastasis remains unclear. METHODS: The metastatic fate of luciferase-expressing rat metastatic colon cancer cells (luc-RCN-H4) injected intravenously into the liver of syngeneic and allogeneic rats was examined in the presence of the immunosuppressant cyclosporin A (CsA) by in vivo luminescent technique. With respect to potential tumor-progressing factors, contribution of chemokine receptors and transforming growth factor (TGF)-beta1 to early metastasis was evaluated using their specific signaling inhibitors. RESULTS: F344 rats injected in the liver with luc-RCN-H4 cells did not always exhibit the formation of tumors and showed a dormant state as long as 60 days after inoculation without CsA. However, CsA released early luc-RCN-H4 cells from dormancy within 2 weeks at nearly 100% in liver and preferentially promoted metastasis to the lymph nodes (approximately 40%). A similar dissemination occurred even in minor histocompatibility complex-disparate hosts. As a tumor-progressing factor, RCN-H4 cells aberrantly expressed chemokine receptors CXCR4 and CCR7. The chemokine receptor (CXC) R4-specific antagonist AMD3100 decreased early metastasis of luc-RCN-H4 cells in rats with ischemic liver conditions (P<0.05), but CsA treatment did not enhance early adhesion. Use of CsA was able to facilitate TGF-beta1 expression and the subsequent TGF-beta-mediated random migration was blocked by the use of the specific signaling inhibitor SB431542 in vitro. CONCLUSIONS: Whereas the chemokine receptor expression by cancer cells is implicated with early organotropic dissemination even under CsA-mediated immune suppression, rather, CsA enhances the late-phase progression after tumor adhesion through TGF-beta1 expression.     

趋化因子CXCL12及其受体在前列腺癌细胞系PC3嗜神经过程中的作用

目的研究CXCL12及其受体CXCR4在前列腺癌嗜神经过程中的作用。方法体外培养前列腺癌PC3细胞，利用Transwell实验观察外源性CXCL12及其受体CXCR4拮抗剂AMD3100对PC3细胞侵袭性的影响。结果体外实验研究表明外源性CXCL12可促进PC3细胞的侵袭性（P〈0．05），而AMD3100明显抑制瘤细胞的侵袭能力（P〈0．05）。结论CXCL12／CXCR4在前列腺癌细胞嗜神经过程中具有重要作用。CXCR4拈抗剂可抑制肿瘤细胞的嗜神经倾向。     

肝卵圆细胞分化过程中SDF-1／CXCR4生物轴的作用研究

目的探讨肝卵圆细胞的激活、增殖和分化过程中基质细胞衍生因子（stromal cell—deftvedfactor-1，SDF-1）及其受体（CXCR4）生物轴的作用机制。方法在三个对照组（2／3肝部分切除组；2/3肝部分切除组及AMD3100预处理组、2/3部分肝切除与二乙酰氨基芴和AMD3100预处理组）的参照下。用光镜与透射电镜观察观察雄性Wistar大鼠经2／3部分肝切除十二乙酰氨基芴预处理后不同时间（术后3，5，7，10，14，21d）肝卵圆细胞的数量、形态和分布变化，采用sP免疫组化法检测卵圆细胞CK18、CK19、AFP、CXCR4和SDF-1的表达，用RT-PCR方法测定SDF-1和CXCR4 mRNA表达水平。结果2-AAF／PH组术后3～10d，CK18、CK19、AFP、ADF-1和CXCR4表达阳性的细胞数量逐渐增加，CXCR4和SDF-1阳性表达见于汇管区附近肝小叶内增生的终末小胆管上皮细胞，以及与增生的胆管／终末小胆管在位置上相延续且形态相类似的卵圆细胞；术后10～14d，CKl8、CK19、AFP、ADF-1和CXCR4阳性细胞数达到最高值；之后，开始下降，至21d则下降至最低水平。自术后3dR，SDF-1和CXCR4mRNA表达水平同步升高，10d升高至峰值，较术后3，5，7d差异均有统计学意义（P均〈0．01），之后开始下降，至21d则下降到最低水平。结论SDF-1／CXCR4生物轴可能有刺激肝干细胞的活化和促进肝卵圆细胞的增殖作用，趋化因子SDF-1及其受体CXCR4可能是肝卵圆细胞的重要标志物。     

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.     

CXCR3在结直肠癌组织中的表达及临床意义

目的 探讨CXCR3在结直肠癌组织中的表达及其临床意义.方法 应用SP免疫组织化学方法检测52例结直肠癌组织CXCR3的表达,Western印迹和体外迁移实验检测趋化因子受体CXCR3在大肠癌细胞株SW480、SW620、HT29细胞的表达及迁移能力.结果 CXCR3的阳性表达率为88%(46/52),CXCR3的高表达与结直肠癌患者的年龄、性别、结直肠癌组织类型、分化程度无关,而与临床转移(肝脏、淋巴结转移)有关(x2=12.1、21.5,P＜0.01).SW480、SW620及HT29的CXCR3表达均呈阳性,其中大肠癌细胞HT29和SW620 CXCR3高表达,大肠癌细胞SW480 CXCR3低表达.在体外迁移实验中,大肠癌细胞HT29和SW620发生体外迁移细胞明显增多(75±6比147±8、63±5比9l±6,P＜0.01),而大肠癌细胞SW480体外迁移无明显变化(47±4比45±3,P>0.05).结论 CXCR3上调表达与结直肠癌转移有关.     

人结直肠癌肿瘤干样细胞生物学特性及其与细胞自噬关系

目的:探讨人结直肠癌肿瘤干样细胞的生物特性及其与自噬发生的关系。方法:采用无血清培养法从人结直肠癌HCT116细胞中获取HCT116球细胞(结直肠癌肿瘤干样细胞);分别用克隆集落形成实验、成球实验、Transwell实验检测HCT116细胞与HCT116球细胞的增殖能力、自我更新能力及侵袭和迁移能力,用免疫荧光法检测两种细胞中自噬标志物LC3B的荧光表达,并用RT-PCR和Western blot分别检测两种细胞中LC3B及自噬相关基因ATG5、ATG7的mRNA与蛋白表达。结果:HCT116球细胞克隆形成能力、新成球能力以及侵袭与迁移能力均较HCT116细胞明显增强(均P0.05)。HCT116球细胞中LC3B的荧光表达强度较HCT116细胞明显增高(P0.05);HCT116球细胞中LC3B、ATG5、ATG7的mRNA和蛋白表达量较HCT116细胞均显明显升高(均P0.05)。结论:结直肠癌肿瘤干样细胞较结直肠癌细胞具有更强的自我更新和体外增殖能力,以及更强的侵袭和迁移能力,该生物学特性可能与其高自噬活性密切相关。     

法尼酯X受体的激活抑制结肠癌细胞生长

目的 探讨法尼酯X受体（FXR）的激活是否抑制结肠癌细胞的生长。方法 对人结肠癌HCT-116细胞进行体外培养,用四唑氮蓝还原法（MTT）和流式细胞仪测定FXR特异性激动剂GW4064对结肠癌HCT-116细胞生长的抑制作用,同时应用RT-PCR方法检测其FXR mRNA及VEGF mRNA的表达。结果 FXR特异性激动剂GW4064可上调结肠癌HCT-116细胞的FXR mRNA表达,下调VEGF mRNA的表达; 对结肠癌HCT-116细胞的生长具有明显的抑制作用,并促进结肠癌HCT116细胞的凋亡,且均呈剂量及时间依赖关系。结论 FXR特异性激动剂GW4064可以显著抑制结肠癌HCT116细胞的生长,激活FXR受体可能为结肠癌的治疗提供一种潜在的靶点。     

Expression of SDF-1/CXCR4 in injured human kidneys

The chemokine SDF-1α is involved in migration, survival, and development of multiple cells, most notably of hematopoietic stem cells (HSC) expressing its ligand CXCR4. Recently, we have shown engraftment of human HSC in the ischemically injured murine kidney, presumably mediated by SDF-1α. To further investigate a possible role of SDF-1α in the recruitment of CXCR4⁺ cells in human renal disease of varying etiologies, we immunostained human biopsies of immunoglobulin (Ig)A nephropathy, minimal-change nephrotic syndrome, focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis, chronic pyelonephritis, and acute tubular necrosis (ATN) for SDF-1α, CXCR4, and CD45, a pan-hematopoietic marker. Irrespective of the diagnosis, intense SDF-1α immunoreactivity was localized to distal tubules and collecting ducts, whereas CXCR4 showed intense staining in both distal and proximal tubules. In addition, whereas varying degrees of CD45⁺ cell infiltrates were observed in all biopsies, we found focal infiltrates of CXCR4⁺ cells mostly localized to the corticomedullary junction only in ischemic ATN. This correlated with more extensive staining for SDF-1α in these sites. In all investigated renopathologic conditions, CD45+ leukocyte recruitment to the kidney seems not to be driven by SDF-1α/CXCR4 interaction. A contribution of SDF-1α for influx of CXCR4⁺ cells in the vicinity of arcuate vessels is suggested only in human ATN.     

SDF-1/CXCR4轴在骨髓间充质干细胞移植促进胰岛再生中的作用

目的 观察同种异体骨髓间充质干细胞(MSCs)移植入受体后,基质细胞衍生因子(SDF)-1/CXCR4轴在促进残存胰岛及其周围新生血管增殖中的作用.方法 对大鼠MSCs进行体外培养、鉴定.链脲佐菌素(STZ)诱导的糖尿病大鼠随机分为A组(MSCs移植组)、B组(MSCs移植+SDF-I/CXCR4轴阻断剂AMD组)和C组(糖尿病对照组),另设D组(正常大鼠对照组).移植MSCs后第30天取出各组大鼠胰腺和血清,胰腺组织采用苏木素-伊红(HE)染色和免疫组织化学法观察CD31、增殖细胞核抗原(PCNA)、胰腺干细胞标志物(PDX)-1在胰腺组织的表达水平.血糖仪检测血糖水平、放免法检测胰岛素水平、酶联免疫吸附试验(ELISA)检测SDF-1水平.结果 (1)A组残存胰岛周围可见新生血管,CD31、PCNA、PDX-1染色阳性率分别为(71.2±5.3)%、(76.5±4.5)%、(69.8±6.7)%;B组残存胰岛周围基本未见新生血管,CD31、PCNA、PDX-1染色阳性率分别为(7.4±2.1)%、(5.5±3.7)%、(8.8±2.9)%,两组比较差异有统计学意义(P＜0.05).(2)移植后第25天,A组血糖浓度基本正常,低于B组和C组,而胰岛素水平明显高于B组和C组(P＜0.05).(3)A组与B组血清SDF-1水平差异无统计学意义(P＞0.05),但都明显高于C组(P＜0.05).结论 MSCs促进胰岛再生和新生血管形成,AMD3100能抑制MSCs的作用,进而提示SDF-1/CXCR4轴在胰岛再生和血管形成中具有重要作用.

Abstract：

Objective To investigate the role of stromal cell derived factor-1 (SDF-1)/CXCR4axis in recipients' remnant islets regeneration and neovascularization after the transplantation of allogeneic bone marrow mesenchymal stem cells (MSCs). Methods MSCs were isolated from SD rats, cultured in vitro and identified by testing the phenotypes with flow cytometry ( FCM ). The diabetic rats induced by streptozotozin were randomly divided into group A ( MSCs transplant group), group B ( MSCs transplant +AMD group) and group C ( DM control group). Group D serve as the normal control. The pancreata were removed and blood serum was retrieved from each group simultaneously at the 13th day after MSCs transplant. The expression of CD31, proliferating cell nuclear antigen (PCNA) and PDX-1 in each group of pancreas tissue was detected by using immunohistochemistry, and the morphological changes in the isletswere observed by Hematoxylin and Eosin (HE) staining. Serum glucose and insulin levels were determined by blood glucose monitor, radioimmunoscintigraphy, and SDF-1 in serum was by enzyme linked immunosorbent assay (ELISA). Results Neovascularization was observed in the remnant islets of the recipient pancreatic tissue and CD31 -positive cells (71.2 ± 5.3 ) %, PCNA-positive cells ( 76. 5 ± 4. 5 ) %, PDX-1-positive cells (69. 8 ±6. 7)% were highly expressed in group A. As compared with group A, seldom-positive cells[CD31 (7.4±2. 1)%, PCNA (5.5 ±3.7)% and PDX-1 (8.8 ±2.9)%]and rarely neovascularization were observed in group B (P ＜0. 05 ). Serum glucose level in group A was lower than that in group B and group C, but serum insulin level in group A was significantly higher than that in group B and group C (P ＜ 0. 05 ). There was no significant difference between group A and group B in serum SDF-1level ( P ＞ 0. 05 ), but that was higher in groups A and B than in group C ( P ＜ 0. 05 ). Conclusion Obviously, MSCs promote recipient neovascularization surrounding the islets, which enhances the proliferation and regeneration of remnant islets. AMD 3100 has the function of intervening SDF-1/CXCR4 axis,which inhibits the effect of MSCs on promoting islets regeneration. It is suggested that SDF-1/CXCR4 axis may play an important role in vascularization and islets regeneration.     

CXCR4 antagonist delivery on decellularized skin scaffold facilitates impaired wound healing in diabetic mice by increasing expression of SDF‐1 and enhancing migration of CXCR4‐positive cells

C‐X‐C chemokine receptor type 4 (CXCR4) is an alpha‐chemokine receptor specific for stromal cell‐derived factor 1 (SDF‐1 also called CXCL12). The antagonist of CXCR4 can mobilize CD34+ cells and hematopoietic stem cells from bone marrow within several hours, and it has an efficacy on diabetes ulcer through acting on the SDF‐1/CXCR4 axis. In this study, we investigated for the first time whether the antagonist of CXCR4 (Plerixafor/AMD3100) delivered on acellular dermal matrix (ADM) may accelerate diabetes‐impaired wound healing. ADM scaffolds were fabricated from nondiabetic mouse skin through decellularization processing and incorporated with AMD3100 to construct ADM‐AMD3100 scaffold. Full‐thickness cutaneous wound in streptozotocin (STZ)‐induced diabetic mice were treated with ADM, AMD3100, or ADM‐AMD3100. 21 days after treatment, wound closure in ADM‐AMD3100‐treated mice was more complete than ADM group and AMD3100 group, and it was accompanied by thicker collagen formation. Correspondingly, diabetic mice treated with ADM‐AMD3100 demonstrated prominent neovascularization (higher capillary density and vascular smooth muscle actin), which were accompanied by up‐regulated mRNA levels of SDF‐1 and enhanced migration of CXCR4 in the granulation tissue. Our results demonstrate that ADM scaffold provide perfect niche for loading AMD3100 and ADM‐AMD3100 is a promising method for diabetic wound healing mainly by increasing expression of SDF‐1 and enhancing migration of CXCR4‐positive cells.     

结直肠癌细胞株趋化因子受体的表达及其趋化实验

目的 观察结直肠癌细胞株趋化因子受体CXCR4的表达及其趋化实验,探讨CXCR4在结直肠癌转移中的作用.方法 培养结直肠癌细胞株HT-29、SW480,采用逆转录-聚合酶链反应(RT-PCR)、免疫组织化学染色、Western blot检测结直肠癌细胞株的趋化因子受体CXCR4表达.采用SDF-1诱导的趋化实验模型检测两种结直肠癌细胞株的趋化活动.结果 免疫组织化学检测每100个HT-29或SW480细胞表达CXCR4蛋白的阳性率分别为48.7%和52.6%,RT-PCR和Western blot检测显示CXCR4呈阳性表达;趋化实验表明区化因子SDF-1处理组的细胞移动计数(HT-29:27.6±3.9;SW480:25.3±4.4)显著高于空白对照组(HT-29:9.6±2.5;SW480:9.8±2.1)和抗体处理组(HT-29:9.1±3.1;SW480:9.3±2.0).结论 结直肠癌细胞株可表达CXCR4,趋化因子SDF-1可以趋化结直肠癌细胞.     

Tropism mechanism of stem cells targeting injured brain tissues by stromal cell-derived factor-1

Objective: To explore the role and function of stromal cell-derived factor- 1 (SDF- 1) in stem cells migrating into injured brain area.Methods: Rat-derived nerve stem cells (NSCs) were isolated and cultured routinely. Transwell system was used to observe the migration ability of NSCs into injured nerve cells. Immunocytochemistry was used to explore the expression of chemotactic factor receptor-4 (CXCR-4) in NSCs. In vivo, we applied immunofluorescence technique to observe the migration of NSCs into injured brain area. Immunofluorescence technique and Western blotting were used to test expression level of SDF- 1. After AMD3100 (a special chemical blocker) blocking CXCR-4, the migration ability of NSCs was tested in vivo and in vitro, respectively.Results: NSCs displayed specific tropism for injured nerve cells or traumatic brain area in vivo and in vitro. The expression level of SDF-1 in traumatic brain area increased remarkably and the expression level of CXCR-4 in the NSCs increased simultaneously. After AMD3100 blocking the expression of CXCR-4, the migration ability of NSCs decreased significantly both in vivo and in vitro.Conclusions: SDF-1 may play a key role in stem cells migrating into injured brain area through specially combining with CXCR-4.     

Tropism mechanism of stem cells targeting injured brain tissues by stromal cell-derived factor-1

Objective: To explore the role and function of stromal cell-derived factor- 1 (SDF- 1) in stem cells migrating into injured brain area.Methods: Rat-derived nerve stem cells (NSCs) were isolated and cultured routinely. Transwell system was used to observe the migration ability of NSCs into injured nerve cells. Immunocytochemistry was used to explore the expression of chemotactic factor receptor-4 (CXCR-4) in NSCs. In vivo, we applied immunofluorescence technique to observe the migration of NSCs into injured brain area. Immunofluorescence technique and Western blotting were used to test expression level of SDF- 1. After AMD3100 (a special chemical blocker) blocking CXCR-4, the migration ability of NSCs was tested in vivo and in vitro, respectively.Results: NSCs displayed specific tropism for injured nerve cells or traumatic brain area in vivo and in vitro. The expression level of SDF-1 in traumatic brain area increased remarkably and the expression level of CXCR-4 in the NSCs increased simultaneously. After AMD3100 blocking the expression of CXCR-4, the migration ability of NSCs decreased significantly both in vivo and in vitro.Conclusions: SDF-1 may play a key role in stem cells migrating into injured brain area through specially combining with CXCR-4.