人脂肪间充质干细胞向表皮细胞表型转化的研究

目的:探索人脂肪间充质干细胞(adipose derived mesenchymal stem cells,ADSCs)向表皮细胞表型转化的方法。方法:以手术中剩余的人皮下脂肪组织为材料来源,利用胶原酶消化法分离ADSCs,流式细胞仪检测细胞表面标记CD29、CD90、CD105的表达,成脂诱导后油红O染色鉴定。实验组利用第四军医大学西京医院烧伤与皮肤外科实验室已成功构建的pc DNA3.1(+)/SP+EGF质粒经脂质体介导转染的Ha Cat细胞,与ADSCs在Transwell小室中共培养,对照组为ADSCs加入10%FBS培养基,14天后Realtime-PCR检测两组ADSCs中CK19、integrin-β的m RNA表达量。结果:实验组ADSCs中CK19、integrin-β的m RNA表达量较对照组明显升高,且差别有统计学意义。结论:转染EGF的Ha Cat细胞可诱导ADSCs向表皮细胞表型分化,从而为其成为组织工程理想的种子细胞提供了进一步的支持。     

Titanium particles suppress expression of osteoblastic phenotype in human mesenchymal stem cells.

Long-term stability of arthroplasty prosthesis depends on the integration between osseous tissue and the implant biomaterial. Integrity of the osseous tissue requires the contribution of mesenchymal stem cells and their continuous differentiation into an osteoblastic phenotype. This study aims to investigate the hypothesis that exposure to wear debris particles derived from orthopaedic biomaterials affects the osteoblastic differentiation of human mesenchymal stem cells (hMSC). Upon in vitro culture in the presence of osteogenic supplements (OS), we observe that cultures of hMSCs isolated from femoral head bone marrow are capable of osteogenic differentiation, expressing alkaline phosphatase, osteocalcin, and bone sialoprotein (BSP), in addition to producing collagen type I and BSP accompanied by extracellular matrix mineralization. Exposure of OS-treated hMSCs to submicron commercially pure titanium (cpTi) particles suppresses BSP gene expression, reduces collagen type I and BSP production, decreases cellular proliferation and viability, and inhibits matrix mineralization. In comparison, exposure to zirconium oxide (ZrO2) particles of similar size did not alter osteoblastic gene expression and resulted in only a moderate decrease in cellular proliferation and mineralization. Confocal imaging of cpTi-treated hMSC cultures revealed patchy groups of cells displaying disorganized cytoskeletal architecture and low levels of extracellular BSP. These in vitro findings suggest that chronic exposure of marrow cells to titanium wear debris in vivo may contribute to decreased bone formation at the bone/implant interface by reducing the population of viable hMSCs and compromising their differentiation into functional osteoblasts. Understanding the nature of hMSC bioreactivity to orthopaedic wear debris should provide additional insights into mechanisms underlying aseptic loosening.     

TGF-β1和bFGFs体外诱导成人骨髓间充质干细胞表达软骨细胞表型的实验研究

目的：从人骨髓中分离间充质干细胞(mesenchymal stem cells，MSCs)，应用流式细胞学技术分析不同细胞因子对细胞增殖分化的影响并观察细胞组织化学特点。结果：MSCs具有独特的表征，即CD29阳性，CD34阴性：TGF—β1(transforming growth faetorsβ1，TGF—β1)、bFGFs(base fibroblast growth faethors，bFGFs)及两者的联合应用可诱导MSCs表达软骨细胞表型向成软骨细胞方向分化：结论：MSCs是一群均一的细胞，具有独特表征，本实验所采用的细胞分离方法为筛选合适的细胞体外扩增及分化提供了有意义的线索。     

非接触共培养脊索细胞诱导骨髓间充质干细胞向类软骨细胞分化的实验研究

目的:分离兔髓核脊索细胞(notochordal cells,NC)及骨髓间充质干细胞(mesenchymal stem cell,MSC),通过非接触共培养探讨NC对MSC细胞表型的影响。方法:4～6周龄新西兰兔8只,取胸腰段脊柱的髓核,用密度梯度离心提取NC,同时取其股骨骨髓用FICOLL液分离MSC,将NC和MSC等比例(1∶1)通过transwell培养板进行非接触共培养作为实验组,单纯MSC细胞培养作为对照组,光镜下观察细胞的生长情况。对两组的MSC行免疫组化及RT-PCR、Western-blot检测MSC细胞表型的改变情况。结果:原代NC呈圆形或椭圆形,细胞体积大,细胞增殖不明显;MSC贴壁生长,呈三角形或梭形,漩涡状排列。甲苯胺蓝染色:对照组MSC细胞核淡染,胞体染色不明显,染色阴性;实验组MSC可见从第3天开始胞体及胞外基质出现紫红色,第5天染色更加明显。Ⅱ型胶原免疫组化对照组MSC淡染,细胞形态不清楚;实验组第3天出现MSC内出现棕黄色深染,随着时间推移细胞染色加深呈阳性表现。RT-PCR检测,经过5d非接触共培养后实验组蛋白聚糖的基因表达为对照组的2.35倍(P<0.05),Ⅱ型胶原的基因表达为对照组的1.61倍(P<0.05),对照组Ⅰ型胶原的基因表达为实验组的2.56倍(P<0.05)。Western-blot检测后发现:经过5d非接触共培养,实验组蛋白聚糖的含量为对照组的1.61倍(P<0.05),Ⅱ型胶原的表达为对照组的10.04倍(P<0.05)(P<0.05)。结论:在非接触共培养条件下脊索细胞可以诱导骨髓间充质干细胞表型发生变化,向类软骨细胞方向分化,这将为组织工程化髓核的种子细胞筛选提供新选择。     

体外诱导人骨髓间充质干细胞向血管平滑肌细胞分化的实验研究

目的应用血小板衍生生长因子BB（platelet-derived growthfactor BB,PDGF-BB）,体外诱导人骨髓间充质干细胞（human bone marrowmesenchymal stemcells,hBMSCs）向血管平滑肌细胞表型分化,探讨该方法的可行性及诱导细胞作为组织工程血管平滑肌种子细胞的可行性。方法抽取健康成人志愿者骨髓,经密度梯度离心分离得单个核细胞,PDGF-BB（20ng/ml）诱导hBMSCs向血管平滑肌样细胞（vascular smooth muscle cells,VSMCs）分化,观察细胞形态变化。免疫荧光检测细胞内血管平滑肌肌动蛋白α（vascular smooth muscleα-actin,SMα-actin）,血管平滑肌钙结合蛋白（vascular smoothmuscle calponin,SMcalponin）,血管平滑肌肌球蛋白重链（vascular smooth muscle myosin heavy chain,SMMHC）和细胞血管平滑肌钙结合相关蛋白（smooth muscle22α,SM22α）表达情况;反转录聚合酶链式反应（RT-PCR）检测诱导后血管平滑肌细胞SMα-actin,SMcalponin,SMMHC和SM22α的mRNA表达。Western印记检测SM22α的表达。流式细胞分析技术（fluorescence activated cell sorter,FACS）分析诱导后细胞内SMα-actin,SMcalponin,SMMHC的表达。结果PDGF-BB20ng/ml诱导后可见单层培养的细胞形态呈“成纤维细胞样”。免疫荧光检测示SMα-actin,SMcalponin,SMMHC,SM22α表达阳性;RT-PCR检测SMα-actin,SMcalponin,SMMHC,SM22α的mRNA阳性表达。Western印迹检测SM22α的表达为阳性。FACS分析表明诱导后,SMα-actin,SMcalponin,SMMHC表达均增高,与未诱导组比较差异有统计学意义（P〈0.05,n=3）。结论人骨髓间充质干细胞在PDGF-BB的诱导下可向血管平滑肌细胞表型分化,有望成为血管组织工程血管平滑肌种子细胞的来源。     

miR-363 induces transdifferentiation of human kidney tubular cells to mesenchymal phenotype

Background

microRNAs (miRNAs) are non-coding small RNAs that regulate embryonic development, cell differentiation and pathological processes via interaction with mRNA. Epithelial–mesenchymal transition (EMT) is pathological process that involves in a variety of diseases such as cancer or fibrosis.

Methods

In this study, we identified miR-363 as a potent inducer of EMT by microarray analysis in human kidney tubular cells, and analyzed the function and mechanisms of miR-363.

Results

Overexpression of miR-363 induced mesenchymal phenotypes with loss of epithelial phenotypes in human kidney tubular cells. In addition, in vitro scratch assay demonstrated that miR-363 promotes cell migration of primary culture of human kidney tubular cells. We identified TWIST/canonical WNT pathway as the downstream effecter of miR-363, and inhibition of canonical WNT by small molecule, IWR-1, attenuated EMT induced by miR-363.

Conclusion

miR-363 induces transdifferentiation of human kidney tubular cells via upregulation of TWIST/canonical WNT pathway.

     

与人汗腺细胞共培养的人骨髓间充质干细胞表型转化中细胞外信号调节激酶通路的作用

目的观察人骨髓间充质干细胞(MSC)与热休克的人汗腺细胞(SGC)间接共培养后,其表型转化情况及细胞外信号调节激酶(ERK)通路所起的作用。方法体外分离和培养人MSC、SGC,采用二步免疫细胞化学法鉴定其均为纯化的SGC、MSC。将原代培养的SGC于47℃下行热休克处理后收集上清液。将第3代MSC作为实验对象并分组。对照组:行常规培养;SGC上清液组:采用含体积分数30％SGC上清液、体积分数1％胎牛血清、1×105U／L青霉素和0．1 g／L硫酸链霉素的DMEM／F12培养基培养;SGC上清液+表皮生长因子(EGF)组、SGC上清液+PD98059组同SGC上清液组处理后,分别添加50μg／L EGF、10μmol／L PD98059继续培养。培养7 d时用流式细胞术检测各组细胞中细胞角蛋白(CK)7、癌胚抗原(CEA)的阳性表达率,以蛋白质印迹法检测ERK和磷酸化ERK(pERK)的表达水平。结果SGC上清液组CK7、CEA阳性表达率分别为(5.76±0．10)％、(2．01±0．09)％;SGC上清液+EGF组分别为(7．31±0.21)％、(7．27+0.12)％;SGC上清液+ PD98059组分别为(1．63±0．11)％、(1．54±0．07)％。与对照组比较,前两组两项指标均明显升高(P<0.01),后一组却与之相近。各组细胞均表达ERK;但pERK水平以SGC上清液+EGF组最高,其次为SGC上清液组,SGC上清液+PD98059组和对照组几乎无表达。结论人MSC、SGC间接共培养可诱导MSC表型转化,ERK通路参与该过程并起着积极作用。     

骨髓间充质干细胞向前列腺癌趋向转移的研究

目的探讨人骨髓间充质干细胞（hMSCs）在体内向前列腺癌微环境趋向转移的特性。方法应用人前列腺癌细胞株PC-3异种皮下种植建立前列腺癌严重联合免疫缺陷小鼠（SCID）模型，通过密度梯度离心和贴壁法分离、培养hMSCs，将体外4,6-联脒-2-苯基吲哚（DAPI）标记的4～6代hMSCs经尾静脉和肿瘤周围注射入荷瘤SCID鼠体内。分别在经尾静脉注射后17d和肿瘤周围注射后7、10、14d处死小鼠，收集肿瘤和肝、肺、脾、肾等脏器作冰冻切片和石蜡切片。在荧光显微镜下观察肿瘤及各脏器中hMSCs的分布情况。结果前列腺癌SCID鼠模型成瘤率83．3％，经尾静脉注射DAPI标记的hMSCs后17d和肿瘤周围注射DAPI标记的hMSCs后7、10、14d，荧光显微镜下显示，前列腺癌组织中可见DAPI标记的hMSCs的核呈蓝色荧光。而肝、肺、脾、肾等脏器中均未见hMSCs的存在。结论hMSCs在体内具有向前列腺癌微环境趋向转移的特性。     

自组装培养形成软骨组织的研究

目的 探讨通过"自组装"(Self-Assembly)培养技术,以生长分化因子-5(GDF-5)诱导人骨髓间充质干细胞(hMSCs),分化形成软骨组织的可能性及效果.方法 将第3代hMSCs用含GDF-5的软骨诱导液定向诱导培养.3周后重悬细胞,自组装培养.对自组装组织团块经行大体观察、逆转录-聚合酶链反应(RT-PCR)、免疫组织化学、软骨相关染色检测.结果 自组装组织团块有类似于软骨的外观,Ⅱ型胶原mRNA表达明显,组织学显示Ⅱ型胶原和蛋白多糖表达阳性.GDF-5诱导组Ⅱ型胶原免疫组织化学平均吸光度为(0.1678±0.0222),对照组平均吸光度为(0.0908±0.0145),差异有统计学意义(P＜0.05).结论 自组装法培养hMSCs能形成具有软骨分子生物学、组织学和生物力学特性的组织团块,而GDF-5能够增强此过程中细胞的软骨表达.     

脊索细胞促进骨髓间充质干细胞增殖及定向诱导分化的研究

目的 分离兔髓核脊索细胞及骨髓间充质干细胞(MSCs),通过共培养观察脊索细胞对MSCs增殖能力及细胞表型的影响.方法 4～6周龄新西兰兔4只,取胸腰段脊柱的髓核,用密度梯度离心法提取脊索细胞,同时取其股骨骨髓用Ficoll液分离得到MSCs,光镜观察脊索细胞和MSCs不同比例(1:2、1:1、2:1)共培养条件下细胞的生长,细胞计数试剂盒(CCK-8)法检测细胞增殖.脊索细胞和MSCs共培养(1:1)后行甲苯胺蓝染色及Ⅱ型胶原染色检测MSCs细胞表型的改变.对共培养后的MSCs进行相关基因表达的检测.结果 光镜下观察原代脊索细胞呈圆形或椭圆形,胞体大,细胞增殖不明显.MSCs呈梭形贴壁生长,旋涡状排列.CCK-8检测发现脊索细胞/MSCs1:1组细胞增殖明显高于其余各组.甲苯胺篮染色MSCs单独培养组呈阴性,共培养组呈阳性.Ⅱ型胶原染色MSCs单独培养组呈阴性,共培养组呈阳性.逆转录-聚合酶链反应(RT-PCR)检测发现共培养组蛋白聚糖及Ⅱ型胶原的表达分别为脊索细胞的2.00、1.35倍,而单独培养的MSCs则表达阴性.结论 在共培养条件下脊索细胞可以促进MSCs增殖,且细胞比例为1:1时更为显著;同时可以诱导其产生Ⅱ型胶原及聚集蛋白聚糖,表现出类软骨细胞表型.     

大鼠骨髓间充质干细胞的分离、培养及表型鉴定

目的 建立大鼠骨髓间充质干细胞分离及培养的方法,探讨体外培养骨髓间充质干细胞的生物学特性.方法 采用密度梯度离心法结合贴壁筛选法分离纯化大鼠骨髓间充质干细胞,传代扩增,测定生长曲线,镜下连续观察细胞的形态变化.流式细胞仪鉴定其表面抗原 CD29、CD34、CD44和CD45的表达情况.结果 原代骨髓间充质干细胞呈集落状生长,细胞呈梭形、纺锤形,呈放射状生长,传代后呈均一的成纤维细胞样.骨髓间充质干细胞生长性状相对稳定,1、3、5代细胞生长曲线基本一致.流式细胞仪鉴定表明,骨髓间充质干细胞CD44、CD29表达呈阳性,CD45、CD38表达呈阴性.结论 采用密度梯度离心法结合贴壁培养法能获得纯度较高的骨髓间充质干细胞,并且在体外培养条件下可大量增生,形成形态均一的细胞集落,可以作为组织工程中种子细胞的来源.     

Olfactory stem cells can be induced to express chondrogenic phenotype in a rat intervertebral disc injury model

BackgroundIn humans, lower back pain is one of the most common causes of morbidity. Many studies implicate degeneration of intervertebral discs as the cause. In the normal intervertebral disc, the nucleus pulposus exerts a hydrostatic pressure against the constraining annulus fibrosus, which allows the disc to maintain flexibility between adjacent vertebrae, while absorbing necessary compressive forces. The nucleus pulposus performs this role because of its hydrophilic gel-like structure. The extracellular matrix of the nucleus pulposus is up to 80% hydrated, as a result of large amounts of the aggregating proteoglycan, chondroitin sulfate proteoglycan (CSPG). This proteoglycan is enmeshed in a randomly orientated network of fine collagen Type II (CT2) fibers.Study design and purposeA useful adult tissue-derived stem cell is that from the olfactory mucosa, the organ of smell. These cells, accessible in humans from nasal biopsies, are multipotent and are able to make many cell types from all germ layers. They are easily grown in vitro and can be expanded to large numbers and stored frozen. These qualities indicate the potential for autologous transplantation for disc repair. In this article, using a rat model, we explore the hypothesis that olfactory stem cells can differentiate into a nucleus pulposus chondrocyte phenotype in vitro, as well as in vivo after transplantation into the injured intervertebral disc.Patient sampleFemale rats (14 weeks) were anesthetized with xylazine/ketamine. The abdominal wall was shaved and injected with local anesthetic (lidocaine) before incision. The ventral part of the lumbar spine, including two intervertebral discs, was exposed. Disc degeneration was then induced in the two exposed discs by needle aspiration of the nucleus pulposus. The prominent spina iliaca posterior superior was used as an anatomical landmark for identification of the first disc. Two weeks later, one injured intervertebral disc was exposed in a second, similar, surgery and 20,000 olfactory neurosphere-derived cells were transplanted with a 25-G needle.Outcome measuresIn vitro induction of nucleus pulposus chondrocyte phenotype is measured by the percentage of cells expressing CT2 and CSPG. In vivo, a successful outcome is evidence of engraftment of donor-derived cells and their expression of CT2 and CSPG.MethodsIn this article, we tested two hypotheses: the first that progenitor cells within olfactory neurospheres could be induced to express markers distinctive of the nucleus pulposus when placed in vitro in a coculture experiment. The second hypothesis tested the same induction in genetically labeled transplanted cells within damaged vertebral discs in vivo. The two markers measured are those held by current literature to engender the necessary cushioning characteristics of nucleus pulposus, CT2 and CSPG.ResultsOur experiments demonstrated virtually 100% induction of these two markers in vitro. Also, this induction was achieved in donor-derived cells after delivery to the nucleus pulposus region of animals whose discs had previously been lesioned 2 weeks before transplant.ConclusionsThese results provide a rationale for moving toward more extensive larger animal studies for assessment of regeneration before human trials where relief of symptoms can be more easily assessed.     

Inorganic polyphosphate differentiates human mesenchymal stem cells into osteoblastic cells

The existence of inorganic polyphosphates [poly(P)] in human cells has been demonstrated. In osteoblasts, it is suggested that the concentration of cellular poly(P) is relatively high. In this study, we examined whether poly(P) accelerates the differentiation of human mesenchymal stem cells (hMSCs) from patients with osteoarthritis (OA) and rheumatoid arthritis (RA) into osteoblastic cells. Alkaline phosphatase (ALP) activity was induced by poly(P) in hMSCs from both OA and RA. In Alizarin Red S and osteocalcin EIA, there was a significant difference between the control and poly(P) group. In real-time PCR, there was a significant difference in ALP, collagen type 1A, osteocalcin, and bone sialoprotein between the control and poly(P) group. Our findings suggest that poly(P) have the potent role of differentiating hMSCs into osteoblastic cells at the early and later stages of osteoblastic differentiation.     

体外人骨髓间充质干细胞向汗腺细胞表型转化的实验研究

目的:研究骨髓间充质干细胞(MSCs)向汗腺细胞分化的可行性.方法:体外分别分离培养、扩增并鉴定MSCs和汗腺细胞,将汗腺细胞置于47℃环境中1 h建立汗腺细胞体外休克模型,继续孵育3～5 d,收集上清液作为条件培养基对MSCs分化诱导,应用免疫组织化学和流式细胞仪法检测对比共培养10 d后MSCs细胞表型的改变.结果...     

Biological responses of human mesenchymal stem cells to titanium wear debris particles

Wear debris-induced osteolysis is a major cause of orthopedic implant aseptic loosening, and various cell types, including macrophages, monocytes, osteoblasts, and osteoclasts, are involved. We recently showed that mesenchymal stem/osteoprogenitor cells (MSCs) are another target, and that endocytosis of titanium (Ti) particles causes reduced MSC proliferation and osteogenic differentiation. Here we investigated the mechanistic aspects of the endocytosis-mediated responses of MSCs to Ti particulates. Dose-dependent effects were observed on cell viability, with doses >300 Ti particles/cell resulting in drastic cell death. To maintain cell viability and analyze particle-induced effects, doses <300 particles/cell were used. Increased production of interleukin-8 (IL-8), but not IL-6, was observed in treated MSCs, while levels of TGF-β, IL-1β, and TNF-α were undetectable in treated or control cells, suggesting MSCs as a likely major producer of IL-8 in the periprosthetic zone. Disruptions in cytoskeletal and adherens junction organization were also observed in Ti particles-treated MSCs. However, neither IL-8 and IL-6 treatment nor conditioned medium from Ti particle-treated MSCs failed to affect MSC osteogenic differentiation. Among other Ti particle-induced cytokines, only GM-CSF appeared to mimic the effects of reduced cell viability and osteogenesis. Taken together, these results strongly suggest that MSCs play both responder and initiator roles in mediating the osteolytic effects of the presence of wear debris particles in periprosthetic zones.     

周期性张力对骨髓间充质干细胞分化的血管平滑肌细胞的表型调节

目的 探讨周期性张力对大鼠骨髓间充质干细胞(BMSCs)诱导分化的血管平滑肌细胞(VSMCs)的表型的调节机制.方法 原代全骨髓法培养大鼠BMSCs,流式细胞术鉴定细胞.作成脂、成骨、成平滑肌细胞方向诱导,验证BMSCs的多向分化潜能.将细胞分为4组:A组用含10 μg/L转化生长因子-β1(TGF-β1)的完全培养基培养,B组用幅度10％、频率1 Hz周期性张力诱导,C组采用TGF-β1+周期性张力联合诱导,D组用含10％胎牛血清(FBS)的DMEM/F12培养基培养作对照.3d后观察诱导后的细胞形态,并行反转录-聚合酶链反应(RT-PCR)检测肌动蛋白(α-actin)、平滑肌肌球蛋白重链(SM-MHC)、钙调节蛋白1(calponin1)、钙调节蛋白3(calponin3)的mRNA表达水平,Western blot观察细胞内α-actin、SM-MHC、calponin1、calponin3蛋白表达水平.结果 经流式细胞术鉴定,所培养细胞为BMSCs.诱导3d后,A、B、C3组的VSMC标志物均较D组明显升高,以SM-MHC和calponin3增加为主.A组(0.919 2±0.028 1)较B组(0.823 6±0.024 6)的SM-MHC蛋白表达水平高,但低于C组(1.043 1±0.090 7),其差异均有统计学意义(P＜0.05).C组中calponin3 mRNA表达量比蛋白表达量变化更明显,而calponin1蛋白表达量和mRNA表达量同步增高.结论 周期性张力能够诱导BMSCs分化为VSMCs,对分化的VSMCs的表型调节还需要细胞因子的参与.     

Inhibition of osteogenic differentiation of human mesenchymal stem cells

Mesenchymal stem cells (hMSCs) have been shown to differentiate into osteoblasts that, in turn, are capable of forming tissues analogous to bone. The present study was designed to investigate the inhibition of osteogenesis by hMSCs. Bone marrow-derived hMSCs were treated with transforming growth factor beta-3 (TGFbeta3) at various doses during or after their differentiation into osteogenic cells. TGFbeta3 was encapsulated in poly(DL-lactic-co-glycolic acid) (PLGA) microspheres and released via controlled delivery in the osteogenic culture of hMSCs and hMSC-derived osteoblasts for up to 28 days. Controlled release of TGFbeta3 inhibited the osteogenic differentiation of hMSCs, as evidenced by significantly reduced alkaline phosphatase activity and staining, as well as decreased mineral deposition. After hMSCs had been differentiated into osteoblasts, controlled release of TGFbeta3 further inhibited not only alkaline phosphatase and mineral deposition but also osteocalcin expression. These findings demonstrate the potential for sustained modulation of the behavior of stem cells and/or stem cell-derived lineage-specific cells via controlled release of growth factor(s). The attenuation of osteogenic differentiation of MSCs may facilitate understanding not only the regulation and patterning of osteogenesis in development but also several pathological models such as osteopetrosis, craniosynostosis, and heart valve calcification.