Effect of erythropoietin on the oriented chemotaxis of bone-marrow mesenchymal stem cells under acute kidney injury microenvironment

Objective To investigate the migration of bone-marrow mesenchymal stem cells (BMSCs) under acute kidney injury (AKI) microenvironment in vitro and the effect of erythropoietin (EPO) intervention, and to explore its underlying mechanism. Methods Renal tubular epithelial cells (RTECs) were cultured in hypoxia/ re-oxygenation (HR) condition for 12 h, respectively, in order to establish HR-RTEC. BMSCs and RTECs were co-cultured by Transwell system and were divided into 7 groups: control group (group①, only BMSC cultured), BMSC-RTEC co-culturing group (group②), BMSC-HR-RTEC co-culturing ＋EPO intervention groups (group③to group⑦, EPO concentration: 0, 1, 5, 10, 50 IU/ml). All the groups were cultured for 48 h and the number of migrating BMSCs was detected. Western blotting was applied for the detection of SDF-1 expression in RTECs and p-MAPK and MAPK levels in BMSCs. SDF-1 concentration in the RTECs culture supernatant was tested by ELISA. Results The number of BMSCs migrating to the low chamber where HR-RTECs were cultured was increased, and EPO intervention further enhanced this migration which reached the peak at the concentration of 10 IU/ml [Compared with group③, (46.67±7.37) cells vs (19.00±2.37) cells, P＜0.05]. Intracellular expression level and the secreated level of SDF-1 in HR-RTECs in group③ were higher than those in RTECs of group② [0.37±0.01 vs 0.19±0.01, P＜0.05; (61.64±4.88) μg/L vs (35.26±8.78) μg/L, P＜0.05]. EPO intervention increased above SDF-1 levels and reached the peak at the concentration of 10 IU/ml [group⑥ vs group③：(173.53±14.66) μg/L vs (61.64±4.88) μg/L, P＜0.05], accompanied with enhanced phosphorylation of MAPK in BMSCs. Conclusions AKI microenvironment has obvious chemotaxis effect on BMSCs, and EPO intervention can strengthen this effect. The increased SDF-1 level and enhanced phosphorylation of MAPK, the downstream signal protein of SDF-1/CXCR4 axis, are the possible mechanism for EPO performance.     

大鼠骨髓间充质细胞经SDF-1预处理后移植对急性心肌梗死的治疗效果

目的 探讨大鼠骨髓间充质细胞(BMSC)经基质细胞衍生因子-1(SDF-1)预处理后移植对急性心肌梗死(AMI)的治疗效果.方法 (1)全骨髓贴壁法培养大鼠BMSC;逆转录聚合酶链反应(RT-PCR)和免疫组织化学法检测BMSC趋化因子受体(CXCR4)基因的表达;将BMSC分别与10和100μg/L的SDF-1作用24 h后,在无氧、无血清条件下培养6 h,流式细胞仪和末端标记(TUNEL)法检测细胞凋亡率.(2)建立大鼠急性心肌梗死模型,将经100μg/L SDF-1预处理的BMSC和未经处理的BMSC植入大鼠梗死心肌周边,2周后采用超声心动图观察心脏功能的变化.结果 BMSC表达CXCR4基因;在无氧和无血清条件下,经SDF-1预处理的BMSC凋亡率与对照组比较明显降低(P<0.05),而经100 μg/L SDF-1预处理的BMSC凋亡率最低.成功建立大鼠急性心肌梗死模型;与未经处理的BMSC移植比较,经SDF-1预处理的BMSC移植后改善心肌梗死大鼠的心功能作用更为明显(P<0.05).结论 用SDF-1预处理大鼠BMSC能抑制其在无氧和无血清条件下的凋亡.用SDF-1预处理BMSC能增强其移植后治疗大鼠急性心肌梗死的效果.     

Transplantation of neurotrophin-3-expressing bone mesenchymal stem cells improves recovery in a rat model of spinal cord injury

Background

This study aimed to investigate the therapeutic effects of transplanting neutrophin-3 (NT-3)-expressing bone marrow-derived mesenchymal stem cells (BMSCs) in a rat model of spinal cord injury (SCI).

Methods

Forty-eight adult female Sprague–Dawley rats were randomly assigned to three groups: the control, BMSC, and NT-3-BMSC groups. BMSCs were infected with NT-3-DsRed or DsRed lentivirus and injected into the cerebrospinal fluid (CSF) via lumbar puncture (LP) 7 days after SCI in the NT-3-BMSC and BMSC groups, respectively. The hind-limb motor function of all rats was recorded using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale on days 1, 3, 7, 14, 21, 28, and 35 after transplantation. Haematoxylin-eosin (HE) staining, immunofluorescence labelling, and western blotting were performed at the final time point.

Results

Expressions of NT-3, brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) proteins increased significantly in the NT-3-BMSC group, and hind-limb locomotor functions improved significantly in the NT-3-BMSC group compared with the other two groups. The cystic cavity area was smallest in the NT-3-BMSC group. In the NT-3-BMSC group, neurofilament 200 (NF200) and glial fibrillary acidic protein (GFAP) expression levels around the lesions were significantly increased and decreased, respectively.

Conclusions

Our findings demonstrate that transplantation of NT-3 gene-modified BMSCs via LP can strengthen the therapeutic benefits of BMSC transplantation. We observed that these modified cells increased locomotor function recovery, promoted nerve regeneration, and improved the injured spinal cord microenvironment, suggesting that it could be a promising treatment for SCI.     

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.     

Protective effects of adipose-derived stem cells with phosphodiesterase 5 inhibition by lentivirus-mediated stable gene silencing on ischemia-reperfusion injury of renal tubular epithelial cells

Objective To explore the protective effects of adipose-derived stem cells (ADSCs) with phosphodiesterase 5 inhibition by lentivirus-mediated stable gene silencing on the proliferation and apoptosis of renal tubular epithelial cells induced by ischemia-reperfusion injury in vitro. Methods To isolate cultivate and indentify ADSCs from rats. Lentiviral expression vector of carrying PDE5 shRNA gene was transfected into ADSCs, and a negative control group was set up．Western blotting was used to detect PDE5 protein expression levels. ADSCs were co-cultured with NRK-52E in a transwell system, and NRK-52E cells were treated with ischemia/reoxygenation protocol. Edu assay was performed to evaluate the proliferation of NRK cells, flow cytometry to detect the apoptosis of NRK cells, and ELISA to quantify the protein expressions of fibroblast growth factor (FGF) and hepatocyte growth factor (HGF). The expression of E-cadherin and cytokeratin 18 (CK18) was quantified by real time PCR and flow cytometry. Results Western blotting for PDE5 protein indicated a significant reduction of PDE5 protein levels in PDE5 shRNA transduced population. After the treatment of ischemia/reoxygenation in vitro, the proliferative viability and apoptosis of NRK-52E cells co-cultured with ADSCs induced by PDE5 gene inhibition were significantly improved, compared to the normal group (all P＜0.05). And the release of HGF, FGF were markedly enhanced (all P＜0.05). Moreover, the NRK-52E cells survival, the expression of E-cadherin and CK18 on PDE5 inhibited ADSCs co-cultured with I/R injured NRK cells was significantly increased compared to that in the negative control group (all P＜0.05). Conclusion ADSCs preconditioned by inhibition of PDE5 can be a powerful novel approach to improve the survival of renal tubular cells following ischemia-reperfusion injury, and have an obvious tendency to transform epithelial cells.     

BMP-2对体外培养人牙囊细胞表达OPG和RANKL的影响

目的：研究BMP-2对体外培养人牙囊细胞表达OPG和RANKL的影响。方法：第5代人牙囊细胞免疫组化染色,检测人牙囊细胞中OPG和RANKL蛋白的表达;第5代人牙囊细胞与浓度为100ng/ml的BMP-2共同孵育0h、1h、3h、6h、12h、18h,RT-PCR法检测OPG和RANKL基因表达的变化。结果：人牙囊细胞OPG、RANKL免疫组化染色阳性;100ng/ml的BMP-2上调OPG蛋白的分泌,最佳效应时间为12～18h,下调RANKL基因的表达,最佳效应时间为6～12h。结论：人牙囊细胞存在OPG、RANKL蛋白的表达;100ng/ml的BMP-2可增强人牙囊细胞OPG蛋白分泌和基因表达,减弱RANKL基因的表达,降低RANKL/OPG的比值,抑制破骨细胞的形成。     

Origins of endothelial and osteogenic cells in the subcutaneous collagen gel implant

The interdependent relationship between vascular endothelial cells and osteoblasts during bone formation and fracture healing has been long appreciated. This paper reports a heterotopic implant model using FGF-2-expanded bone marrow stromal cells (BMSC) derived from Tie2eGFP (endothelial marker) and pOBCol3.6GFPcyan or topaz (early osteoblast marker) transgenic mice to appreciate the host/donor relationships of cells participating in the process of heterotopic bone formation. The study included various combinations of Tie2eGFP and pOBCol3.6GFPcyan and topaz transgenics as BMSC or whole bone marrow (WBM) donors and also as recipients. Rat tail collagen was used as a carrier of donor cells and implantation was done in lethally irradiated mice rescued with WBM injection. Development of ossicles in the implants was followed weekly during the 4- to 5-week long post-implantation period. By 4-5 weeks after total body irradiation (TBI) and implantation, a well-formed bone spicule had developed that was invested with bone marrow. Experiments showed absolute dominance of donor-derived cells in the formation of endothelial-lined vessels inside the implants as well as the marrow stromal-derived osteogenic cells. Host-derived fibroblasts and osteogenic cells were confined to the fibrous capsule surrounding the implant. In addition, cells lining the endosteal surface of newly formed marrow space carrying a pOBCol3.6GFP marker were observed that were contributed by WBM donor cells and the host. Thus, FGF-2-expanded BMSC appear to be a source of endothelial and osteogenic progenitor cells capable of eliciting heterotopic bone formation independent of cells from the host. This model should be useful for understanding the interactions between these two cell types that control osteogenic differentiation in vivo.     

骨髓间充质干细胞向成骨细胞分化中CXCR4蛋白表达的研究

目的 探究中医补肾阴、补肾阳、健脾、补肾健脾不同治法对骨髓间充质干细胞向成骨细胞分化过程中CXCR4蛋白表达的影响,从而为中药防治骨质疏松症提供依据。方法 体外分离培养大鼠BMSCs,将SPF雌性SD大鼠用随机数字表法随机分成6组,依次分别为：正常组、诱导液组、补肾阴组、补肾阳组、健脾组、补肾健脾组。对大鼠进行7 d灌胃,制备含药血清,各组成骨诱导18 d后,进行茜素红染色检测矿化情况,采用酶联免疫吸附法(ELISA)检测上述每组细胞上清液CXCR4、BMP2蛋白表达水平。结果 诱导18 d后,与正常组相比,补肾阳组与补肾健脾组BMP-2含量均显著升高(P<0.01),诱导组、补肾阴组BMP-2含量有所升高,但差异不具有统计学意义(P>0.05);与诱导组相比,补肾健脾组BMP-2含量均显著升高(P<0.01),补肾阴组与补肾阳组BMP-2含量有所升高,但差异无统计学意义(P>0.05),各含药组BMP-2蛋白浓度比较依次为：补肾健脾组>补肾阳组>补肾阴组>健脾组;与正常组相比,各组CXCR4含量均显著升高(P<0.01),且补肾健脾组上...     

慢病毒介导骨形态发生蛋白-7基因的干细胞用于组织工程骨构建的实验研究

目的 建立能够稳定表达骨形态发生蛋白-7(BMP-7)的骨髓基质干细胞(BMSCs),观察其成骨分化,并与纳米羟基磷灰石胶原(nHAC)材料复合培养体外构建组织工程骨的可行性.方法 实验分4组:BMP-7和eGFI基因转染组(A组)、eGFP基因转染组(B组)、常规成骨诱导组(C组)、未转染组(D组).用G418筛选获得阳性细胞后接种于nHAC支架体外复合培养.荧光显微镜下观察eGFP表达,判断转染效率;以逆转录-聚合酶链反应(RTPCR)、ELISA检测目的基因表达,四唑盐(MTT)实验检测细胞活力,碱性磷酸酶(ALP)活性和Gomori染色榆测成骨情况;扫描电镜观察细胞在支架材料中的黏附、生长状况.结果 慢病毒24 h对BMSCs的转染率约为90%.RTPCR检测到A组在1300 bp处出现特异性条带,其他组结果阴性;ELISA检测24 h BMP-7蛋白含量为(150.2±18.3)pg/mL,种植支架复合培养8周后BMP-7含量为(76.6±7.4)pg/mL;MTT实验显示细胞活性与未转染组比较差异无统计学意义(P>0.05);ALP活性以16 d最强;扫描电镜见细胞种植nHAC支架后黏附、生长良好.结论 BMP-7可在BMSCs内稳定表达,并诱导其向成骨分化;与nHAC复合培养可构建组织工程骨.     

骨形成蛋白-2和牙胚细胞联合作用诱导人牙周膜干细胞表达成牙骨质细胞的表型研究

目的:探讨大鼠牙胚细胞(Tooth germ cells,TGC)与骨形成蛋白-2(Bone morphogenetic proteins-2,BMP-2)联合作用对人牙周膜干细胞(Human periodontal ligament stem cells,hPDLSCs)向成牙骨质细胞表型分化的作用。方法:将免疫磁珠法分离的hPDLSCs与TGC共培养,并加入50ng/mL的BMP-2,通过RT-PCR,茜素红染色和碱性磷酸酶(Alkaline Phosphatase,ALP)活性检测等方法分析其相关成牙骨质基因及蛋白的表达变化。结果:诱导后hPDLSCs的ALP活性明显升高(P0.001),牙骨质细胞相关基因如牙骨质附着蛋白(Cementum attachment protein,CAP)、牙骨质蛋白(Cementum protein1,CEMP-1)、ALP,骨钙素(Osteocalcin,OCN)的转录水平表达量均有不同程度的增高(P0.001)。矿化诱导14d后,诱导组形成大量矿化结节,与对照组相比具有统计学意义(P0.001)。结论:TGC与BMP-2联合作用能够诱导hPDLSCs与向成牙骨质细胞的表型分化。     

骨髓间充质干细胞表达肿瘤坏死因子刺激蛋白-6对大鼠肝脏移植排斥反应的影响

目的 探讨骨髓间充质干细胞(BMSC)表达肿瘤坏死因子刺激蛋白-6(TSG-6)在大鼠原位肝移植排斥反应的作用.方法 Kupffer细胞(KCs)和BMSC分离培养,慢病毒载体(LV3-shTSG-6)感染下调TSG-6的表达,RT-PCR以及Western blot检测BMSC的TSG-6mRNA以及蛋白表达情况,KCs与BMSC共培养,检测上清液TNF-α、TSG-6含量;建立大鼠原位肝移植急性排斥反应模型,术后1d、3d、7d处死3只受体,检测血清AST、ALT、TBIL、γ-GGT、TNF-α、IL-6、IL-4含量,RT-PCR以及Western blot检测肝组织TSG-6mRNA以及蛋白表达情况,苏木精-伊红染色观察肝组织结构,各组剩余大鼠观察术后生存率.结果 BMSC慢病毒转染率＞70％;KCs和BMSC共培养,TSG-6-shRNA-BMSC+ KCs组各时间点分泌TSG-6明显低于BMSC+ KCs组和TSG-6-NC-BMSC+ KCs组(P＜0.05),BMSC+ KCs组和TSG-6-NC-BMSC+ KCs组分泌TNF-α于6h达高峰,12 h与6h比较明显降低(P＜0.05),但TSG-6-shRNA-BMSC+ KCs组12 h分泌TNF-α明显高于BMSC+ KCs组和TSG-6-NC-BMSC+ KCs组(P＜0.05);移植术后,TSG-6-shRNA-BMSC组ALT、AST、TBIL、γ-GGT、TNF-α、IL-6明显高于TSG-6-NC-BMSC组和BMSC组(P＜0.05),与PBS组比较差异无统计学意义;TSG-6-shRNA-BMSC组、TSG-6-NC-BMSC组和BMSC组IL-4明显高于PBS组(P＜0.05),而TSG-6-shRNA-BMSC组IL-4低于TSG-6-NC-BMSC组和BMSC组(P＜0.05);在肝脏病理中,TSG-6-shRNA-BMSC组与PBS组肝组织排斥反应程度明显较高,Banff评分Ⅱ～Ⅲ级;TSG-6-shRNA-BMSC组与PBS组大鼠肝移植术后存活时间分别为(16.6±4.6)d、(15.4±6.7)d,明显低于TSG-6-NC-BMSC组(69.6±28.1)d和BMSC组(69.2±28.2) d(P ＜0.05).结论 BMSC分泌表达TSG-6在一定程度上具有减轻肝移植急性排斥反应的作用.     

以海藻酸三维支架构建骨髓间充质干细胞源性生物人工肝组织的实验研究

目的 以骨髓间质干细胞(bone mesenchymal stem cell,BMSC)为种子细胞,以海藻酸三维支架为载体,研究两者的相容性及其构建生物人工肝组织的可能性.方法 将大鼠BMSC接种于海藻酸三维支架上,采用倒置相差显微镜、扫描电镜分别检测BMSC的黏附、生长与增殖情况,评价两者的相容性;同时以表皮生长因子(EGF)、肝细胞生长因子(HGF)、成纤维生长因子4(FGF-4)等细胞因子混合液诱导BMSC向肝细胞分化,检测培养液内尿素氮和白蛋白含量,RT-PCR检测培养细胞ALB和AFP基因的表达,糖原染色及免疫荧光法检测细胞糖原合成功能和CK-18的表达. 结果大鼠BMSC在海藻酸三维支架上能正常地黏附、生长和增殖;于海藻酸三维支架内加入诱导液作用于BMSC后,培养液内尿素和ALB的含量逐渐上升,RT-PCR检测到培养细胞有AFP和ALB基因的表达,同时被诱导的细胞具有糖原储存的功能并表达CK-18.结论 海藻酸三维支架与大鼠BMSC具有良好的相容性;以EGF、HGF、FGF-4等细胞因子混合液为诱导因子,能在海藻酸三维支架上成功诱导BMSC向肝细胞分化;海藻酸三维支架和BMSC可望成为肝脏组织工程理想的种子细胞和细胞载体.     

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。     

Role of hepatocyte growth factor in invasion of prostate cancer cell lines through tumor-stromal interaction

We examined how prostate stromal cell-derived hepatocyte growth factor (HGF) affects invasion of prostate cancer cells through tumor-stromal interaction. The effects of HGF, various growth factors [transforming growth factor (TGF)-alpha, TGF-beta 1, basic fibroblast growth factor, keratinocyte growth factor, and platelet-derived growth factor], and conditioned medium (CM) from prostate stromal cells (PrSC) on prostate cancer cells (LNCaP, PC-3 and DU145) were determined by collagen gel invesion assay. DU145 cells and PrSC were co-cultured for matrigel invasion chamber assay. LNCaP and PC-3 cells did not respond to any of the factors examined. Invasion of DU145 cells into the collagen gel matrix was induced by HGF and TGF-beta 1, but not by any of the other factors tested. When DU145 cells were cultured in CM from PrSC or co-cultured with PrSC, the cells acquired invasive potential, and this invasion was inhibited by an antibody against HGF, but not against TGF-beta 1. Induction activity of CM from cancer cells to stimulate HGF production by PrSC was studied by ELISA method and Western blotting. Native type HGF production in PrSC was enhanced by some unknown inducer(s) produced by cancer cells. In summary, PrSC-derived HGF enhanced invasive activity of the prostate cancer cell line DU145 through tumor-stromal interaction wherein DU145 cells secreted some HGF-inducer(s) for PrSC.     

促红细胞生成素预处理增强大鼠骨髓间充质干细胞定向归巢能力的初步研究

目的 探讨促红细胞生成素(EPO)对大鼠骨髓间充质干细胞(BMSC)增殖及迁移能力的影响.方法 将第5代BMSC分为5组,分别为对照组(不加EPO)及10、100、500、1000 IU/mL EPO组,培养24 h和48 h后检测各组BMSC的增殖率、迁移能力以及趋化因子受体(CXCR)4的表达情况.将第5代BMSC...     

Bone marrow mesenchymal stem cells undergo nemosis and induce keratinocyte wound healing utilizing the HGF/c-Met/PI3K pathway

We previously showed cell–cell contacts of human dermal fibroblasts to induce expression of the hepatocyte growth factor/scatter factor (HGF) in a process designated as nemosis. Now we report on nemosis initiation in bone marrow mesenchymal stem cells (BMSCs). Because BMSCs are being used increasingly in cell transplantation therapy we aimed to demonstrate a functional effect and benefit of BMSC nemosis for wound healing. Nemotic and monolayer cells were used to stimulate HaCaT keratinocyte migration in a scratch-wound healing assay. Both indicators of nemosis, HGF production and cyclooxygenase-2 expression, were induced in BMSC spheroids. When compared with a similar amount of cells as monolayer, nemotic cells induced keratinocyte in vitro scratch-wound healing in a concentration-dependent manner. The HGF receptor, c-Met, was rapidly phosphorylated in the nemosis-stimulated keratinocytes. Nemosis-induced in vitro scratch-wound healing was inhibited by an HGF-neutralizing antibody as well as the small molecule c-Met inhibitor, SU11274. HGF-induced in vitro scratch-wound healing was inhibited by PI3K inhibitors, wortmannin and LY294002, while LY303511, an inactive structural analogue of LY294002, had no effect. Inhibitors of the mitogen-activated protein kinases MEK/ERK1/2 (PD98059 and U0126), and p38 (SB203580) attenuated HGF-induced keratinocyte in vitro scratch-wound healing. We conclude that nemosis of BMSCs can induce keratinocyte in vitro scratch-wound healing, and that in this effect signaling via HGF/c-Met is involved.     

骨髓间质干细胞培养上清液调控肝细胞的体外研究

目的探讨骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSC)培养上清液对肝细胞增殖、凋亡的影响,初步探讨BMSC治疗肝纤维化的旁分泌机制。方法采用密度梯度离心及贴壁细胞分离相结合提取BMSC。培养48h的BMSC细胞培养上清液按BMSC不同处理(培养)时间和含量两种方法建组。不同处理时间建组:取培养48hBMSC上清液处理肝细胞(完全培养),分为处理24h、48h、72h组,对照组为1640培养基处理24h的肝细胞。不同含量BMSC建组:实验1组为完全BMSC培养上清液(含肝细胞的6孔板中每孔加入BMSC上清液2ml)处理肝细胞;实验2组为部分BMSC培养上清液(每孔加BMSC上清液1ml+1640培养基1ml)处理肝细胞;对照组为完全细胞培养基(每孔加1640培养基2ml)处理肝细胞。用酶联免疫吸附试验(ELISA)试剂盒检测BMSC旁分泌肝细胞生长因子(hepatocyte growth factor,HGF)情况及培养时间对其的影响;用流式细胞仪观察肝细胞细胞分期和检测凋亡细胞数;用蛋白免疫印迹法(Western-blot)检测样本上清液中白蛋白的表达。结果 BMSC分泌HGF,其含量变化具有时间依赖性。加入BMSC培养上清液后,与对照组相比,实验1组中的培养上清液可以明显促进肝细胞增殖、抑制其凋亡,并随着处理时间的延长而增加(处理72h>处理48h>处理24h,均为P<0.05);实验组(1组、2组)的白蛋白分泌较对照组上调,且随着处理时间的延长白蛋白含量增加。结论 BMSC有可能通过分泌HGF促进肝细胞增殖、抑制凋亡,促进白蛋白分泌,从而抑制肝脏纤维化。     

大鼠雪旺细胞对两种来源的成骨细胞增殖分化影响的研究

目的 研究应用雪旺细胞(SCs)对两种来源的成骨细胞(OB)的增殖与分化的影响,为构建神经化组织工程骨提供体外实验理论依据.方法 通过采用股骨、胫骨髓腔冲洗法获得SD大鼠骨髓基质干细胞(BMSCs),采用胰蛋白酶消化新生鼠颅骨获得OB及采用消化后组织块法获得SCs.将BMSCs在成骨诱导液作用3周,鉴定BMSCs向OB分化.采用96孔共培养板将第2代SCs种植于上室,颅骨来源OB种植下室,共培养为实验组,无SCs干预共培养为对照组.将诱导分化的OB种植于下室,第2代SCs种植于上室,共培养为实验组,无SCs干预共培养为对照组,分别于共培养后1、3、5、7、9d采用甲基噻唑基四唑(MTT)进行增殖比较.采用6孔共培养板,实验组上室种植SCs,下室分别种植颅骨来源及BMSCs来源的OB,不加SCs的两种来源的OB作为对照组,分别共培养后于3、7 d检测两种来源OB的碱性磷酸酶、骨钙素、骨桥蛋白、骨形态发生蛋白-2 mRNA表达.结果 SCs对颅骨来源的OB在共培养3、5、7、9 d 4个时间点均有明显促增殖作用,在碱性磷酸酶、骨桥蛋白、骨形态发生蛋白-2mRNA在各个时间段均起到抑制作用.SCs对大鼠BMSCs来源的OB在共培养1、3 d无明显促增殖作用,在5、7、9 d有明显促增殖作用,在成骨培养基的环境里,SCs可促进BMSCs诱导的OB分化.结论 选择BMSCs来源的OB 与 SCs共培养更适合用于构建神经化组织工程骨.     

局部植入辛伐他汀诱导自体骨髓间充质干细胞归巢修复大鼠颅骨缺损

目的探讨局部植入辛伐他汀修复大鼠颅骨极限骨缺损的机制,即诱导自体骨髓间充质干细胞（BMSC）归巢。方法辛伐他汀5mg加聚乳酸20mg或单纯聚乳酸20mg分别溶解于200μl丙酮,制备辛伐他汀聚乳酸复合材料或单纯聚乳酸材料。16只SD大鼠尾静脉注射绿色荧光蛋白（GFP）标记的BMSC（GFP-BMSC）作为示踪细胞,48h后制作大鼠颅骨极限缺损模型,并植入辛伐他汀-聚乳酸复合材料（n=8）和单纯聚乳酸材料（n=8）进行修复。2周后经小动物活体荧光成像系统检测缺损处绿色荧光信号,冰冻切片荧光显微镜下观察辛伐他汀组（n=4）和对照组（n=4）缺损处GFP-BMSC归巢。颅骨脱钙后经免疫组化染色检测辛伐他汀组（n=4）和对照组（n=4）缺损处骨形态发生蛋白-2（BMP-2）表达。结果小动物活体荧光成像系统检测显示,辛伐他汀组缺损处有较强的绿色荧光信号,对照组缺损处绿色荧光信号较弱;冰冻切片荧光显微镜下观察发现,辛伐他汀组缺损处较对照组缺损处GFP阳性细胞数量明显增加;免疫组化检测发现,辛伐他汀组BMP-2表达增加。结论局部植入辛伐他汀可诱导自体BMSC归巢至缺损部位并参与修复,其诱导归巢过程可能与BMP-2表达上调有关。