二甲双胍联合放射线照射对鼻咽癌细胞CNE-1增殖的影响

目的:探讨二甲双胍联合放射线照射对鼻咽癌细胞CNE-1增殖的影响。方法:分别给予鼻咽癌细胞CNE-1二甲双胍(5m M)、2Gy放射线照射、二甲双胍(5 m M)联合2Gy放射线照射处理后,采用MTT实验、克隆形成实验检测和比较其细胞增殖抑制率和克隆形成抑制率。结果:MTT实验结果显示:与二甲双胍组或2Gy放射线照射组相比,二甲双胍联合放射线照射组细胞增殖抑制率显著升高,差异具有统计学意义(P0.05);克隆形成实验结果显示,与二甲双胍组或2Gy放射线照射组相比,二甲双胍联合放射线照射组细胞克隆形成抑制率显著升高,差异具有统计学意义(P0.05)。结论:二甲双胍联合放射线照射能够有效的抑制鼻咽癌细胞CNE-1的增殖。     

二甲双胍联合卡铂对三阴性乳腺癌细胞增殖的影响

目的:探讨二甲双胍联合卡铂对三阴性乳腺癌细胞MDA-MB-231增殖的影响。方法:体外培养三阴性乳腺癌细胞MDA-MB-231,分别给予不同浓度(0、2.5、5、10 mmol/L)二甲双胍和20μmol/L卡铂处理后,采用MTT实验、平板克隆实验检测二甲双胍联合卡铂对MDA-MB-231细胞增殖的影响。结果:MTT实验结果显示:二甲双胍抑制MDA-MB-231细胞的增殖,5、10mM组细胞OD490值均显著低于对照组(P0.05),且10 mM组细胞OD490值明显低于其他各组(P0.05);与单药相比,二甲双胍和卡铂联用组细胞生长抑制率显著升高,差异具有统计学意义(P0.05)。平板克隆实验结果显示:与单药相比,二甲双胍和卡铂联用组细胞的克隆形成抑制率率显著升高,差异具有统计学意义(P0.05)。结论:二甲双胍联合卡铂能够有效的抑制三阴性乳腺癌细胞MDA-MB-231的增殖。     

二甲双胍对胶质母细胞瘤细胞的抑制作用研究

为了探究二甲双胍对不同胶质母细胞瘤U87细胞、GL261细胞及C6细胞增殖的影响,选取小鼠GBM细胞GL261细胞系、大鼠GBM细胞C6细胞系及人源GBM细胞U87MG细胞系,使用二甲双胍处理,通过CCK-8法检测细胞增殖活性;细胞实时荧光检测细胞凋亡水平;平板克隆实验检测GBM细胞克隆形成能力;CCK-L法检测胞内ATP水平;Western blot检测Akt及其磷酸化水平。结果显示,与对照组相比,随着作用浓度增加,二甲双胍显著抑制GBM细胞增殖活性,影响细胞形态;与对照组相比,同一作用浓度下,二甲双胍提高了GBM细胞凋亡水平,抑制了GBM细胞克隆形成能力,降低了GBM胞内ATP的产生;二甲双胍处理24 h后,GBM细胞内p-Akt表达显著下调,Akt无明显变化。结果表明,二甲双胍在体外可抑制多种GBM细胞的增殖、克隆,降低胞内ATP水平,其机制可能与Akt磷酸化水平相关,研究结果为进一步探索二甲双胍对胶质母细胞瘤的作用机制提供了体外研究理论基础。     

二甲双胍联合奥沙利铂抑制胃癌细胞SGC-7901的增殖和诱导凋亡

探讨体外培养的人胃癌细胞株SGC-7901经由二甲双胍与奥沙利铂联合处理后增殖和凋亡的响应及药物作用机制。采用CCK-8增殖检测法检测药物处理下对细胞的增殖影响并计算出两种药物的IC50值。采用RT-PCR、Western blotting以及流式细胞术检测药物作用下SGC-7901细胞周期相关和凋亡相关蛋白的mRNA水平、蛋白水平和凋亡水平。实验结果显示,二甲双胍和奥沙利铂单独作用都能够抑制SGC-7901细胞的增殖,联合用药组较单独用药组对细胞的抑制率更高。二甲双胍和奥沙利铂单独作用都能够抑制SGC-7901细胞cyclin D1的mRNA和蛋白水平,药物联用后,对细胞cyclin D1的抑制表达效果更明显。与对照组相比较,二甲双胍和奥沙利铂单独作用均能显著诱导SGC-7901细胞发生凋亡(p0.01),联合用药组亡率((50.13±10.75)%)明显高于单独用药的二甲双胍组((35.06±9.17)%)和奥沙利铂组((42.59±11.98)%)。二甲双胍和奥沙利铂单独都能够抑制SGC-7901细胞中抗凋亡蛋白Bcl-2的mRNA和蛋白表达水平,并增加促凋亡蛋白Bax以及凋亡执行caspase3的mRNA和蛋白表达水平,而联合用药组中这种调控效果更加显著。二甲双胍与奥沙利铂能够抑制胃癌细胞的增殖并诱导细胞发生凋亡,可能是通过促进Bax和caspase3的表达,抑制cyclin D1和Bcl-2表达来实现的。     

二甲双胍联合阿霉素应用对人乳腺癌细胞增殖和凋亡的影响

目的：观察二甲双胍联合阿霉素应用对人乳腺癌细胞MDA-MB-231增殖和凋亡的影响。方法：MTT法分别检测二甲双胍、阿霉素和二甲双胍联合阿霉素对MDA-MB-231细胞生长的抑制作用;平板克隆实验检测二甲双胍联合阿霉素对MDA-MB-231细胞克隆形成能力的影响;流式细胞仪检测二甲双胍联合阿霉素对MDA-MB-231细胞凋亡的影响。结果：二甲双胍和阿霉素分别对MDA-MB-231细胞生长有抑制作用,二甲双胍联合阿霉素应用对MDA-MB-231细胞生长的抑制作用更加显著,并且随着药物浓度的增加而增加;二甲双胍联合阿霉素应用与单药相比能够明显降低MDA-MB-231细胞克隆形成率,并且促进细胞凋亡。结论：二甲双胍联合阿霉素应用与单药相比能够显著抑制人乳腺癌细胞MDA-MB-231细胞的增值,促进其凋亡,可见两药联用对肿瘤细胞的杀伤具有协同性。     

二甲双胍增强胰腺癌放疗敏感性的体外及体内实验研究

目的:探讨二甲双胍对胰腺癌细胞和胰腺癌裸鼠移植瘤放疗敏感性的影响。方法:体外培养人胰腺癌Bx PC-3和As PC-1细胞,分为二甲双胍处理组和未处理组,处理组给予10 mmol/L二甲双胍作用48小时后分别给予0、1、2、4、6、8Gy射线对两种细胞进行照射,运用克隆形成实验,Giemsa染色后计算克隆形成率及SF2,并拟合细胞存活曲线。应用裸鼠皮下注射胰腺癌细胞,建立两种细胞的裸鼠移植瘤模型,裸鼠肿瘤体积达到100 mm~3时,作为0天,并开始分组,每种移植瘤使用24只裸鼠随机分为4组:生理盐水对照组、单纯二甲双胍治疗组、单纯照射组、二甲双胍+照射组,二甲双胍处理组每天给予250 mg/kg(50μL/每只)腹腔注射,对照组仅给予等量生理盐水注射(50μL/每只)。每4天用游标卡尺测量移植瘤的长径和宽径,并绘制生长曲线。当对照组体积达到200 mm~3时,照射组和联合组,给予一次性照射6Gy射线,当对照组体积达到1000 mm~3时,将裸鼠进行麻醉,剥出皮下移植瘤,进行称量和保存,并计算抑瘤率。结果:两细胞系经过二甲双胍处理后,经2、4、6、8Gy照射后存活分数明显低于未处理组(P0.01),随着照射剂量的增大,克隆形成数量明显减少,两个细胞系经二甲双胍处理后进行照射,其SF2、D0,N值均较未处理组明显减少(P0.01),表明经二甲双胍处理后,Bx PC-3细胞和As PC-1细胞的放射敏感性增强,增敏比分别为1.2368和1.1179。二甲双胍和放射联合处理组的体积、瘤重均明显小于对照组和单独处理组,Bx PC-3和As PC-1移植瘤的抑瘤率分别为62.14%、61.53%,均明显高于各自单独处理组(P0.01或P0.05)。结论:二甲双胍能够增强胰腺癌的放疗敏感性,在临床上具有潜在的应用价值。     

二甲双胍对低级别非侵袭性膀胱肿瘤细胞增殖的影响

目的:初步探讨降糖药物二甲双胍对膀胱肿瘤细胞253J的作用及其相关作用机制。方法:采用Cell Counting Kit-8(CCK-8)试剂盒分析二甲双胍对膀胱肿瘤细胞增殖的影响。应用流式细胞仪检测二甲双胍对细胞周期及凋亡的影响。并通过免疫印迹方法检测相关蛋白确定可能参与其中的信号分子。结果:在各时间点(24小时,48小时,72小时)二甲双胍处理组与对照组相比膀胱肿瘤细胞的增殖受到明显抑制(P0.01或P0.05);与对照组比较,二甲双胍处理组G0/G1期细胞比例上升,S期细胞比例下降(P0.01或P0.05);免疫蛋白印迹发现,二甲双胍处理组中的磷酸化AMP激活的蛋白激酶(AMP-activated protein kinase,AMPK)表达升高,同时细胞周期蛋白D1(cyclin D1)的表达下降(P0.01或P0.05)。结论:体外实验中二甲双胍能够明显抑制膀胱肿瘤细胞的增殖,通过下调cyclin D1的表达诱导细胞周期停滞于G0/G1期。这些结果表明二甲双胍可能成为治疗膀胱癌的潜在药物。     

二甲双胍抑制H1299细胞迁移及其机制研究

该文主要研究二甲双胍(metformin, Met)对肺腺癌H1299细胞增殖、迁移和凋亡的影响,并探讨其可能作用机制。利用显微镜观察二甲双胍处理后细胞形态,划痕实验检测二甲双胍对细胞迁移的影响; Annexin V/PI标记,流式检测二甲双胍对细胞凋亡的影响; 5-乙炔基-2’脱氧尿嘧啶(Edu)法检测二甲双胍对细胞增殖的影响。结果表明,二甲双胍能改变H1299细胞形态且能显著抑制细胞迁移;二甲双胍不能诱导H1299细胞凋亡;二甲双胍能抑制H1299细胞增殖。进一步研究发现,二甲双胍能下调p-ERK和p-MEK蛋白水平,同时增加E-Cadherin和减少FAK、vimentin蛋白表达,说明二甲双胍主要通过抑制ERK信号通路抑制H1299细胞增殖和迁移,并通过上调E-Cadherin、下调FAK、vimentin使H1299细胞迁移受到明显抑制,为二甲双胍应用于肺腺癌的预防及治疗提供了指导依据。     

二甲双胍(Metformin)在少突胶质前体细胞分化中的作用和机制*

目的：研究二甲双胍(metformin)在少突胶质前体细胞(oligodendrocyte precursor cell, OPC)分化过程中的作用,并对其分子机制进行初步探讨。方法：使用免疫吸附法直接分离纯化OPC后诱导培养,通过免疫荧光染色对细胞进行鉴定。在不同浓度二甲双胍处理OPC后,使用CCK8检测细胞活性;通过免疫荧光染色、流式细胞分析、实时荧光定量PCR和蛋白质印迹检测二甲双胍对OPC分化中细胞数量、mRNA和蛋白质水平的影响。结果：使用免疫吸附法可分离出高纯度OPC;CCK8检测结果显示在100 μmol/L浓度以内,二甲双胍对细胞无毒性;免疫荧光染色结果显示,二甲双胍处理OPC后,PDGFRα ⁺ OLIG2⁺阳性细胞数明显增加,且MBP⁺细胞数显著增加;流式细胞分析结果显示,PDGFRα⁺细胞数显著增加;实时荧光定量PCR结果显示,OPC分化相关基因Mag、Mbp等的mRNA水平显著增加;蛋白质印迹结果显示,分化相关蛋白OLIG2和MBP表达增加。机制上,少突胶质细胞系Oli-neu、OPC分别经二甲双胍处理5 min后,RAS、p-MEK、p-ERK蛋白量显著增加。结论：二甲双胍通过RAS-MEK-ERK信号通路促进少突胶质前体细胞的分化。     

二甲双胍联合塞来昔布对胰腺癌细胞增殖及Caspase-3活性的影响

目的:探讨二甲双胍和塞来昔布单独或联合应用对胰腺癌细胞增殖和Caspase-3活性的影响。方法:体外培养人胰腺癌BxPC-3和As PC-1细胞,用四甲基偶氮唑盐(MTT)法检测不同浓度二甲双胍和塞来细胞对胰腺癌细胞存活率的影响。联合实验分4组:对照组、二甲双胍组(MET,15 mmol/L)、塞来昔布组(CEL,100μmmol/L),二甲双胍和塞来昔布联合组(MET 15 mmol/L+CEL100μmmol/L),孵育48 h,用MTT检测细胞存活率,用Caspase-3比色测定试剂盒测定Caspase-3活性。结果:二甲双胍和塞来昔布单药均可以时间和剂量依赖性方式降低胰腺癌Bx PC-3和As PC-1细胞的生存率。两种细胞系的各加药组细胞存活率与对照组比较差异均存在统计学意义(P0.01),联合实验组的细胞存活率明显低于单独用药组(P0.01)。二甲双胍和塞来昔布单药处理的胰腺癌Bx PC-3和As PC-1细胞Caspase-3活性均显著高于对照组(P0.01),二甲双胍和塞来昔布联合实验组Caspase-3活性均明显高于单药处理组和对照组(P0.01),但二甲双胍组和塞来昔布组之间的Caspase-3活性比较差异无统计学意义(P0.05)。结论:二甲双胍和塞来昔布联合作用可协同抑制胰腺癌细胞的增殖,并通过激活Caspase-3活性促进胰腺癌细胞的凋亡,其联合应用可能成为胰腺癌药物治疗的有效策略。     

1950 MHz射频电磁场对人脐带间充质干细胞增殖和成骨分化的影响研究

目的:间充质干细胞(Mesenchymal stem cells,MSCs)具有广阔的临床应用前景,但由于其体外增殖和定向分化等问题,制约了其进一步应用。本研究拟探讨1950MHz射频电磁场(Radio-frequency electromagnetic fields,RF-EMF)对人脐带间充质干细胞(Human umbilical cord mesenchymal stem cells,hUC-MSCs)增殖和成骨方向分化的影响,以期为MSCs的体外增殖和定向分化提供一条新途径。方法:华通氏胶组织块法分离培养人脐带间充质干细胞,流式细胞仪检测间充质干细胞特异性标志物。选择鉴定后的第3至第6代(P3-P6)hUC-MSCs用于实验。将hUC-MSCs细胞暴露或假暴露于频率为1950 MHz,比吸收率(Specific absorption rate,SAR)分别为0.5,1.0和2.0 W/kg的RF-EMF中,每天暴露1 h(5 min开,10 min关),连续暴露7 d。暴露结束后,流式细胞仪检测细胞周期,免疫荧光检测增殖相关蛋白Ki67表达,连续6天用CCK-8方法检测细胞数。在成骨分化研究中,将P3代的hUC-MSCs随机分为假暴露(sham)组,射频辐射暴露(RF)组,成骨诱导培养基组(Induction medium,OM)和成骨诱导培养基联合射频辐射暴露(OM+RF)组,暴露SAR值为2.0 W/kg,其它参数不变。暴露结束后立即检测细胞的碱性磷酸酶(Alkaline phosphatase,ALP)活性。结果:原代培养的细胞具有MSC典型外观,且表达MSCs特异性表面抗原。与sham组相比,不同SAR值RF暴露后,hUC-MSCs的增殖能力无明显变化,S期细胞比例及Ki67蛋白水平也无显著改变。此外,hUC-MSCs经SAR值为2.0W/kg的RF暴露7 d,与sham组相比其ALP活性无显著变化。与OM组相比,OM+RF组的ALP活性亦无显著改变。结论:华通氏胶组织块法能够培养出纯度较高的间充质干细胞,本实验条件下的1950 MHz射频电磁场对hUC-MSCs的增殖和成骨分化均无显著影响。     

Differentiation-dependent secretion of proangiogenic factors by mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a promising cell population for cell-based bone repair due to their proliferative potential, ability to differentiate into bone-forming osteoblasts, and their secretion of potent trophic factors that stimulate angiogenesis and neovascularization. To promote bone healing, autogenous or allogeneic MSCs are transplanted into bone defects after differentiation to varying degrees down the osteogenic lineage. However, the contribution of the stage of osteogenic differentiation upon angiogenic factor secretion is unclear. We hypothesized that the proangiogenic potential of MSCs was dependent upon their stage of osteogenic differentiation. After 7 days of culture, we observed the greatest osteogenic differentiation of MSCs when cells were cultured with dexamethasone (OM+). Conversely, VEGF protein secretion and upregulation of angiogenic genes were greatest in MSCs cultured in growth media (GM). Using conditioned media from MSCs in each culture condition, GM-conditioned media maximized proliferation and enhanced chemotactic migration and tubule formation of endothelial colony forming cells (ECFCs). The addition of a neutralizing VEGF(165/121) antibody to conditioned media attenuated ECFC proliferation and chemotactic migration. ECFCs seeded on microcarrier beads and co-cultured with MSCs previously cultured in GM in a fibrin gel exhibited superior sprouting compared to MSCs previously cultured in OM+. These results confirm that MSCs induced farther down the osteogenic lineage possess reduced proangiogenic potential, thereby providing important findings for consideration when using MSCs for bone repair.     

Effects of 50 Hz pulsed electromagnetic fields on the growth and cell cycle arrest of mesenchymal stem cells: an in vitro study

Mesenchymal stem cells (MSCs) are capable of self-renew and multipotent differatiation which allows them to be sensitive to microenvironment is altered. Pulsed electromagnetic fields (PEMF) can affect cellular physiology of some types of cells. This study was undertaken to investigate the effects of PEMF on the growth and cell cycle arrest of MSCs expanded in vitro. To achieve this, cultured of normal rat MSCs, the treatment groups were respectively irradiated by 50 Hz PEMF at 10 mT of flux densities for 3 or 6 h. The effects of PEMF on cell proliferation, cell cycle arrest, and cell surface antigen phenotype were investigated. Our results showed that exposed MSCs had a significant proliferative capacity (P < 0.05) but the effect of PEMF for 3 and 6 h on cell growth was not different (P>0.05) at an earlier phase after PEMF treatment. Exposure to PEMF had a significant increase the percentage of MSCs in G1 phase compare with the control group, with a higher percentage of cells in G1 phase exposed for 6 h then that for 3 h. At the 16th hour after treatment, PEMF had no significant effect on cell proliferation and cell cycle (P>0.05). These results suggested that PEMF enhanced MSCs proliferation with time-independent and increased the percentage of cells at the G1 phase of the cell cycle in a time-dependent manner, and the effect of PEMF on the cell proliferation and cell cycle arrest of MSCs was temporal after PEMF treatment.     

In vitro Response of the Bone Marrow-Derived Mesenchymal Stem Cells Seeded in a Type-I Collagen-Glycosaminoglycan Scaffold for Skin Wound Repair Under the Mechanical Loading Condition

In order to achieve successful wound repair by regenerative tissue engineering using mesenchymal stem cells (MSCs), it is important to understand the response of stem cells in the scaffold matrix to mechanical stress.
To investigate the clinical effects of mechanical stress on the behavior of cells in scaffolds, bone marrow-derived mesenchymal stem cells (MSCs) were grown on a type-I collagen-glycosaminoglycan (GAG) scaffold matrix for one week under cyclic stretching loading conditions.
The porous collagen-GAG scaffold matrix for skin wound repair was prepared, the harvested canine MSCs were seeded on the scaffold, and cultured under three kinds of cyclic stretching loading conditions ( 0%: control, 5% strain, 15% strain ). After 7 days incubation, MSCs were evaluated histologically and immunohistochemically regarding the proliferation and differentiation.
Cultured MSCs in the high strain (15% strain) group showed activea-smooth muscle actin (α-SMA) expression and poor differentiation into type-I collagen-positive cells, whereas enhanced differentiation into type-I collagen positive cells and a lack ofa-SMA expression where shown in the lower stress (5% strain) group. These results suggest that mechanical stress may affect the proliferation and differentiation of stem cells, and subsequently the wound healing process, through attachment interactions between the stem cells and scaffold matrix. Our findings provide an additional consideration for clinical treatment of wound repair using regenerative tissue engineering.     

Exogenous type I collagen facilitates osteogenic differentiation and acts as a substrate for mineralization of rat marrow mesenchymal stem cells in vitro

We cultured rat mesenchymal stem cells (MSCs) in a medium containing beta-glycerophosphate, ascorbic acid, and dexamethasone to show in vitro osteogenic differentiation of the MSCs. The differentiation was enhanced by adding solubilized type I collagen to the medium as evidenced by higher alkaline phosphatase activity as well as more calcium deposition than that without collagen. The exogenous collagen integrated well with the mineralized bone matrix and maintained the native triple helical structure. These findings indicate that exogenously supplemented type I collagen acts as a component of the extracellular matrix of MSCs, and deposited type I collagen facilitates osteogenic differentiation followed by maturation of mineralized bone matrix.     

Effects of Bone Marrow Stromal Cell-conditioned Medium on Primary Cultures of Peripheral Nerve Tissues and Cells

Implantation of bone marrow stromal cells (MSCs) produces an improved functional outcome of peripheral nerve repair. In this study, rat dorsal root ganglion (DRG) explants, rat DRG neurons, and rat Schwann cells (SCs) were treated with monkey MSC-conditioned medium, respectively, and then subjected to MTT assay, Bromodeoxyuridine/Hoechst 33342 double staining, flow cytometry, immunohistochemistry, real-time quantitative PCR, and Western blot analysis, respectively. The results showed that MSC-conditioned medium enhanced axon growth and neurogenesis in cultured DRG explants, augmented cell survival of and expression of NF and GAP-43 by cultured DRG neurons, promoted cell survival and proliferation of cultured SCs, and increased the expression of NGF, BDNF, and bFGF in cultured SCs. We also found that mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (Erk) 1/2 pathway was involved in the enhanced cell proliferation of SCs evoked by MSC-conditioned medium. The data of this study might help the understanding of MSCs-based treatment for peripheral nerve repair.     

Purmorphamine enhances osteogenic activity of human osteoblasts derived from bone marrow mesenchymal cells

Purmorphamine is a novel small molecule with osteogenesis-inducing activity in multipotent mesenchymal progenitor cells, but there has been no evaluation of its effect on human cells to date. The aim of this study was to investigate the induction of osteogenic activity by purmorphamine in human osteoblasts differentiated from bone marrow mesenchymal cells. Cells were cultured in 24-well plates at a density of 2x10(4)/well in medium containing 1, 2 or 3 microM purmorphamine, or vehicle. At 7, 14 and 21 days, cell proliferation, viability, and alkaline phosphatase (ALP) activity were evaluated. Bone-like nodule formation was evaluated at 21 days. Purmorphamine did not affect cell proliferation or viability, but increased ALP activity and bone-like nodule formation. These results indicate that events related to osteoblast differentiation, including increased ALP activity and bone-like nodule formation, are enhanced by purmorphamine.     

Conditions to improve expansion of human mesenchymal stem cells based on rat samples

AIM: To improve the isolation and expansion of human marrow-derived mesenchymal stem cells (MSCs) based on rat samples. METHODS: Based on the fact that rat MSCs are relatively easy to obtain from a small aspirate, bone marrow-derived MSCs from rat were cultured and characterized to set up the different protocols used in this study. Then, accordingly, almost the same protocols were performed on human healthy bone marrow samples, after obtaining approval of the ethics committee and gaining informed consent. We used different protocols and culture conditions, including the type of basal media and the culture composition. The MSCs were characterized by immunophenotyping and differentiation. RESULTS: There was no difference in morphology and proliferation capacity between different culture media at the first passage. During the 5-7th passages, the cells gradually lost their morphology and proliferation potential on Dulbecco’s modified Eagle’s medium (DMEM) high glucose and α modified Eagle’s medium. Although the cells expanded rapidly for up to 10 passages on DMEM low glucose containing 10% to 15% fetal calf serum (FCS), their proliferation was arrested without change in morphology and differentiation capacity at the third passage on 5% FCS. Flow cytometric analysis and functional tests confirmed that more than 90% of marrow cells which were isolated and expanded by our selective protocols were MSCs. CONCLUSION: We improved the isolation and expansion of human bone marrow derived MSCs, based on rat sample experiments, for further experimental and clinical use.     

Spheroid formation and differentiation into hepatocyte-like cells of rat mesenchymal stem cell induced by co-culture with liver cells

Mesenchymal stem cells (MSCs) derived from bone marrow have been shown to differentiate into hepatocytes, which would be an ideal resource for transplantation or artificial liver devices. Here we investigated the efficiency of co-culture system consisting of rat MSCs and adult liver cells to induce differentiation of MSCs into hepatocyte-like cells. Marked MSCs were either co-cultured with freshly isolated liver cells or treated with hepatocyte growth factor (HGF) for 21 days. In co-culture systems, MSCs formed spheroids of round-shaped cells while keeping normal proliferation and viability, strongly expressed albumin, alpha-fetoprotein, and cytokeratin-18 in mRNA and protein level from day 3 to 21. As a control, MSCs treated with HGF showed weak gene expressions in day 14 and had a few cells of protein staining in day 21. These results indicate that the co-culture microenvironment plays a decisive role for the hepatic differentiation of MSCs, and it is more efficient than HGF treatment. Insights gained from this study will be helpful to design optimal culture systems for the hepatic differentiation of human MSCs and the hepatic function maintenance of hepatocytes in vitro.     

低氧对 MSCs 增殖和分化的影响

摘要： 间充质干细胞(mesenchymal stem cells, MSCs)是具有自我更新、 多向分化和强可塑性的细胞, 具有分化为血液、 骨、 软骨、 脂 肪、 肌肉、 表皮、 上皮、 神经等组织的潜能, 受到再生医学研究的关注。目前已有研究表明将 MSCs 移植到多种损伤组织中都能改 善损伤组织的功能。文章在简要回顾了低氧环境对 MSCs 增殖和分化的研究内容和有关理论争论基础上重点介绍了缺氧诱导因 子 （ HIF ）通路对 MSCs 增殖和分化的影响。文章阐述了低氧环境对 MSCs 向成骨,成软骨,成脂及成神经元方向分化的影响。 由于 人体组织内生理条件下的氧张力远远小于大气中的氧张力 （21% ）, 采用低氧培养 MSCs 的研究方法得出的结论将更加贴近实际 MSCs 在人体内的增殖、分化情况。因此研究 MSCs 在低氧张力环境中增殖、分化的能力将为 MSCs 能成功移植到体内并发挥作 用提供保障。