Effect of adipose-derived mesenchymal stem cells on hepatocellular carcinoma: In vitro inhibition of carcinogenesis

AIM To investigate the effect of adipose-derived mesenchymal stem cells(ADMSCs)and their conditioned media(CM) on hepatocellular carcinoma(HCC) cell tumorigenesis.METHODS The proliferation rate of HepG2 and PLC-PRF-5 HCC cancer cells was measured using the trypan blue exclusion method and confirmed using the cell-counting kit8(commonly known as CCK-8) assay. Apoptosis was detected by flow cytometry using annexin V-FITC. Protein and mRNA expression was quantified by ELISA and real time PCR, respectively. Migration and invasion rates were performed by Transwell migration and invasion assays. Wound healing was examined to confirm the data obtained from the migration assays.RESULTS Our data demonstrated that when co-culturing HCC cell lines with ADMSCs or treating them with ADMSC CM, the HCC cell proliferation rate was significantly inhibited and the apoptosis rate increased. The decreased proliferation rate was accompanied by an upregulation of P53 and Retinoblastoma mRNA and a downregulation of c-Myc and hTERT mRNA levels. More notably, ADMSCs and their CM suppressed the expression of the two important markers of HCC carcinogenicity, alpha-fetoprotein and Des-gamma-carboxyprothrombin. In addition, the migration and invasion levels of HepG2 and PLC-PRF-5 cells significantly decreased, potentially through increased expression of the tissue inhibitor metalloproteinases TIMP-1, TIMP-2 and TIMP-3.CONCLUSION These findings shed new light on a protective and therapeutic role for ADMSCs and their CM in controlling HCC invasiveness and carcinogenesis.     

脂肪干细胞诱导成心肌细胞研究

目的:探讨体外培养的脂肪干细胞（ADSCs）转化为心肌细胞的可能性和最佳诱导时机。方法:取新西兰白兔ADSCs,体外培养扩增。将传代不同次数的ADSCs以不同的5-氮杂胞苷浓度诱导,探讨最佳诱导浓度和时机,观察诱导后细胞的形态变化以及传代对心肌管样细胞数量的影响。免疫细胞化学方法鉴定。结果:ADSCs接种后生长迅速,呈短梭形,细胞形态单一。5-氮杂胞苷浓度对细胞的生长有显著影响,随着5-氮杂胞苷浓度的增加,细胞数量显著减少。诱导剂有效浓度为69μmol/L,以终浓度为9μmol/L对第3代ADSCs诱导产生的心肌细胞数量最多。5-氮杂胞苷诱导后最早于第9天形成肌管样结构,以肌纤维蛋白、α-横纹肌肌动蛋白和心肌肌钙蛋白T单克隆抗体检测均为阳性。诱导后细胞传代导致心肌细胞数量显著减少。结论:ADSCs在体外可有效转化为心肌细胞,它可能是心肌细胞移植的良好细胞来源。     

人脂肪间充质干细胞体外分离、培养的方法研究

目的：探讨人脂肪间充质干细胞体外分离及培养方法。方法用消化离心的方法获得人脂肪间充质干细胞,以1×104/cm2接种于体积分数为0．1％胎牛血清的LG-DMEM培养基中,并进行细胞形态学观察,绘制细胞生长曲线,流式细胞仪检测细胞表面抗原,行成脂及成骨诱导检测其多向分化潜能。结果获取的脂肪间充质干细胞大小较为均匀,呈梭形的成纤维细胞样,细胞增殖良好;细胞生长曲线测定表明接种后第4天细胞进入指数增长期,第8天后生长进入平台期,体外能长期培养存活,并保持不分化状态;流式细胞仪检测表明细胞高表达 CD13、CD73,低表达 CD34、CD45及 HLA-DR;能诱导成脂及成骨细胞。结论利用消化离心法在体外能分离得到脂肪间充质干细胞,细胞生长良好,可作为组织工程的种子细胞。     

大鼠脂肪间充质干细胞在部分肝切除模型中向肝细胞分化的研究

目的探讨脂肪间充质干细胞（ADMSCs）在部分肝切除模型中向肝细胞的分化。方法从大鼠脂肪组织中分离出干细胞，并进行体外扩增、传代，取第2代ADMSCs用PKH26标记，制作部分肝切除模型，将标记细胞经门静脉自体植入体内。2周后切下肝脏制成冰冻切片，荧光显微镜下观察标记细胞在肝脏的定位，进行免疫荧光染色检测标记细胞白蛋白的表达。结果从脂肪组织中分离出的ADMSCs能在体外大量扩增，PKH26标记后细胞在荧光显微镜下发红色荧光，细胞标记率约95％；荧光显微镜下可见肝脏冰冻切片中散在分布红色标记细胞，免疫荧光染色显示大多数标记细胞白蛋白染色阳性。结论 大鼠脂肪间充质干细胞在肝再生环境中能向肝细胞分化，有可能在肝部分切除后参与肝再生。     

Expression of liver‐specific markers in naïve adipose‐derived mesenchymal stem cells

Background: Increasing evidence suggests that adipose tissue contains mesenchymal stem cells (MSC) that possess the ability to transdifferentiate into other cell types including hepatocytes, similar to bone marrow‐derived stem cells. The existence of precommitted cells in the MSC population may explain transdifferentiation. Aims: Our aim was to identify a population of putative hepatocyte‐like precursor cells in human adipose tissue. Methods: We analysed the ‘basal’ hepatic potential of undifferentiated, naïve human adipose‐derived mesenchymal stem cells (hADMSC). hADMSC were isolated from human adipose tissue and characterized for cell surface markers and for liver‐specific gene expression. Results: The isolated undifferentiated naïve hADMSCs expressed MSC surface markers. They also expressed α‐fetoprotein, CK18, CK19 and HNF4, which are known as early liver expressing genes. Interestingly, the undifferentiated naïve hADMSC were also positive for albumin, G‐6‐P and α‐1‐antitrypsin (AAT), which are all known to be predominantly expressed in adult liver cells. These cells acquired a hepatocyte‐specific phenotype and function upon treatment with a differentiation medium, resulting in the upregulation of albumin, G‐6‐P and AAT. Moreover, urea production, glycogen storage ability and cellular uptake of indocyanine green, which were absent in the basal state, were evident in the treated cells. Conclusions: Our findings suggest the presence of cells with hepatocyte‐like properties that are isolated from human adipose tissue and that can readily acquire hepatocyte‐like functions. Adipose tissue could thus be an exciting alternative means for repopulating the liver after various injuries, and might serve as a source for the transplantation of liver cells.     

体外诱导人羊膜间充质干细胞分化为胰岛素分泌细胞

目的 探讨体外诱导人羊膜间充质干细胞(hAD-MSCs)向胰岛素分泌细胞分化潜能.方法 采用胰蛋白酶-胶原酶消化法分离提取hAD-MSCs,流式细胞术分析和免疫细胞化学染色行表型鉴定.取第3代按2.5× 106个/ml或5×105个/ml细胞密度接种6孔培养板或预置盖玻片的24孔培养板,在含10mmol/L尼克酰胺和N2补充物的无血清HG-DMEM培养基培养,未诱导组为含10％胎牛血清的LG-DMEM基础培养基.分别于体外诱导第7、14、21天采用免疫细胞化学法检测胰岛素和β2微球蛋白的表达,采用放射免疫法检测上清液中胰岛素含量,采用RT-PCR检测胰岛素mRNA和胰十二指肠同源异型盒因子1(PDX-1)mRNA的表达.结果 (1)hAD-MSCs高表达间充质干细胞表面标志CD29、CD44、CD73、CD166及波形蛋白;(2) hAD-MSCs诱导第7、14、21天胰岛素阳性细胞百分率分别为74.67％±1.53％、75.00％±1.00％、74.33％±1.53％,培养物上清液中胰岛素含量分别为(331.62±1.76)、(330.50±1.22)和(331.65±0.48) μIU/ml,各时点间比较无显著性差异(均P＞0.05),而未诱导组仍未见胰岛素阳性细胞;培养上清也未检测到胰岛素;(3) hAD-MSCs诱导前后均有PDX-1 mRNA和蛋白表达,胰岛素基因mRNA表达仅见于诱导组;(4) hAD-MSCs诱导组和未诱导组各时点均有β2微球蛋白表达,其阳性细胞百分率组间差异无显著性(均P＞0.05).结论 hAD-MSCs具有向胰岛素分泌细胞分化的能力,可能成为1型糖尿病细胞移植治疗的新的细胞供源.     

体外诱导入骨髓间充质干细胞向肝系细胞分化过程中的基因表达谱变化

目的 应用微阵列分析骨髓间充质干细胞向肝系细胞分化的基因表达变化.方法 收集健康志愿者胸骨骨髓,分离间充质干细胞体外培养,应用HGF+ FGF4诱导分化并鉴定分化细胞;利用微阵列技术筛选骨髓间充质干细胞向肝系细胞分化的有关基因.结果 121条基因表达发生变化,其中89条上调,32条下调.结论 相关基因涉及信号转导、能量代谢、基因转录、蛋白质翻译与合成等.SGK、ApoB、LDLR和CETP等可能在其分化过程中有非常重要的意义.     

Role of stromal-derived factor-1 in the hematopoietic-supporting activity of human mesenchymal stem cells

Mesenchymal stem cells (MSC) have the ability to support and maintain hematopoiesis in vitro. However, mechanisms implicated in this support are not fully characterized. In the present study, the role of stromal-derived factor-1 (SDF-1)/CXCR4 axis in the interactions between MSC and hematopoietic stem/progenitor cells (HSPC) was studied. Human bone marrow MSC were plated as feeder layers in Dexter-type long-term cultures (LTC) with human cord blood CD34(+) HSPC. Cultures were supplemented weekly with neutralizing antibodies against CXCR4 or SDF-1 for 5 wk. LTC-initiating cell (IC) activity was strongly dependent on the SDF-1/CXCR4 axis, as both antibodies significantly decreased secondary colony-forming cell production. To assess the effect of SDF-1/CXCR4 axis on progenitor cell proliferation, LTC-IC killing assays were carried out: in LTC of CD34(+) cells in contact with MSC, treatment with anti-CXCR4 antibody significantly reduced the number of cycling progenitors. These results indicate that the SDF-1/CXCR4 axis promotes HSPC proliferation in contact with MSC. Interestingly, when HSPC were separated from MSC by a semipermeable membrane, LTC-IC activity became CXCR4 independent. Multiplex analysis of MSC-conditioned medium revealed that in addition to SDF-1, MSC produced stimulatory and inhibitory factors, such as interleukin (IL)-6, IL-11, granulocyte macrophage-colony stimulating factor as well as monocyte-chemoattractant protein-1. Altogether, human MSC support hematopoiesis in Dexter-type cultures through the activation of the SDF-1/CXCR4 axis. Our data further suggest that SDF-1 stimulates retention of HSPC in MSC niches which expose them to stimulatory and inhibitory factors in a paracrine manner.     

Macrophages and mesenchymal stromal cells support survival and proliferation of multiple myeloma cells

Multiple myeloma (MM) is characterized by almost exclusive tropism of malignant cells for the bone marrow (BM) milieu. The survival and proliferation of malignant plasma cells have been shown to rely on interactions with nonmalignant stromal cells, in particular mesenchymal stromal cells (MSCs), in the BM microenvironment. However, the BM microenvironment is composed of a diverse array of cell types. This study examined the role of macrophages, an abundant component of BM stroma, as a potential niche component that supports malignant plasma cells. We investigated the proliferation of MM tumour cell lines when cultured alone or together with MSCs, macrophages, or a combination of MSCs and macrophages, using the carboxyfluorescein succinimidyl ester assay. Consistently, we observed increased proliferation of MM cell lines in the presence of either MSCs or macrophages compared to cell line-only control. Furthermore, the combined co-culture of MSCs plus macrophages induced the greatest degree of proliferation of myeloma cells. In addition to increased proliferation, MSCs and macrophages decreased the rate of apoptosis of myeloma cells. Our in vitro studies provide evidence that highlights the role of macrophages as a key component of the BM microenvironment facilitating the growth of malignant plasma cells in MM.     

Insight into the development of obesity: functional alterations of adipose‐derived mesenchymal stem cells

Obesity is associated with a variety of disorders including cardiovascular diseases, diabetes mellitus and cancer. Obesity changes the composition and structure of adipose tissue, linked to pro‐inflammatory environment, endocrine/metabolic dysfunction, insulin resistance and oxidative stress. Adipose‐derived mesenchymal stem cells (ASCs) have multiple functions like cell renewal, spontaneous repair and homeostasis in adipose tissue. In this review article, we have summarized the recent data highlighting that ASCs in obesity are defective in various functionalities and properties including differentiation, angiogenesis, motility, multipotent state, metabolism and immunomodulation. Inflammatory milieu, hypoxia and abnormal metabolites in obese tissue are crucial for impairing the functions of ASCs. Further work is required to explore the precise molecular mechanisms underlying its alterations and impairments. Based on these data, we suggest that deregulated ASCs, possibly also other mesenchymal stem cells, are important in promoting the development of obesity. Restoration of ASCs/mesenchymal stem cells might be an additional strategy to combat obesity and its associated diseases.     

Estrogen deficiency does not decrease the in vitro osteogenic potential of rat adipose-derived mesenchymal stem cells

Osteoporosis due to estrogen deficiency is an increasing bone health issue worldwide: new strategies are being studied for regenerative medicine of bone pathologies in these patients. The most commonly used cells for tissue engineering therapy are the bone marrow mesenchymal stem cells (BMSCs), but they might be negatively affected by aging and estrogen deficiency. Besides the general advantages of adipose-derived mesenchymal stem cells (ADSCs) over BMSCs, ADSCs also seem to be less affected by aging than BMSCs, but in the literature, little is known about ADSCs in estrogen deficiency. The present study investigated the in vitro behavior of ADSCs, isolated from healthy (SHAM) and estrogen-deficient (OVX) rats. Phenotype, clonogenicity, viability, and osteogenic differentiation, at both cellular and molecular levels, were evaluated with or without osteogenic stimuli. Pro-inflammatory cytokines, growth factors, and adipogenic differentiation markers were also analyzed. There were no significant differences between OVX and SHAM ADSCs in some analyzed parameters. In addition, clonogenicity, osteopontin (Spp1) gene expression, alkaline phosphatase (ALP) activity at 2 weeks of culture, total collagen (COLL), osteocalcin (Bglap) gene expression and production, and matrix mineralization were significantly higher in OVX than in SHAM ADSCs. Besides the increase in some osteogenic markers, peroxisome proliferator-activated receptor gamma (Pparg) gene was also more expressed in OVX in osteogenic medium, with a concomitant estrogen receptor 1 (Esr1) gene expression decrease. These results underlined that ADSCs were not affected by estrogen deficiency in an osteogenic microenvironment.     

体外诱导间充质干细胞向心肌细胞方向分化的研究

目的证实来源于胎儿肝脏的间充质干细胞(FMSCs)具有向心肌细胞方向分化的潜能。方法取6~9代细胞,用不同浓度的诱导剂组合诱导细胞,分别置于不同的条件下进行培养,包括不同温度、不同氧浓度及不同培养液。结果在使用心肌分化培养液及常规培养条件下(37℃、20%O2),5-氮胞苷(50μmol/L)、维甲酸(10-3μmol/L)、二甲基亚砜(0.8%)的联合应用,诱导了FMSCs发生向心肌方向的分化。分化细胞呈小圆形细胞,具有相互聚集并形成球样细胞团结构的趋势,同时表达结蛋白及心肌肌钙蛋白Ⅰ。结论FMSCs具有向心肌细胞分化的潜能,FMSCs发生向心肌方向的分化所需条件与来源于其他动物种属的间充质干细胞的分化条件不同。     

体外诱导骨髓间充质干细胞向神经元样细胞分化的研究

目的观察人骨髓间充质干细胞（BM-MSCs）体外扩增和定向诱导分化为神经元样细胞的变化,为其临床应用奠定基础。方法采用密度梯度离心法分离BM-MSCs细胞,用MesencultTM培养基和贴壁培养法培养、纯化和扩增细胞,流式细胞术检测细胞表面CD29和CD90分子表达率。采用20 ng/ml重组碱性成纤维细胞生长因子（bFGF）、20 ng/ml新型人表皮生长因子（hEGF）和20 g/L二甲基亚砜（DMSO）、5 mmol/Lβ-巯基乙醇（BME）分别诱导BM-MSCs;采用免疫组化法检测细胞的神经元特异性烯醇化酶（NSE）、胶原纤维酸性蛋白（GFAP）、波形蛋白（VIM）表达情况。结果BM-MSCs细胞增殖迅速,3周可传代培养;BM-MSCs传十代扩增1－2×10^3倍。分离和扩增BM-MSCs CD29、CD90强表达率分别为95.02%、93.81%。药物诱导后的BM-MSCs发生轴突等神经元样细胞变化,阳性表达NSE、GFAP、VIM分子。结论人BM-MSCs能体外培养和扩增,并能定向诱导分化为神经元样细胞。     

体外诱导小鼠骨髓间充质干细胞分化为肝样细胞

目的:体外诱导小鼠骨髓间充质干细胞分化(BMSCs)为肝样细胞,提高分化效率.方法:将第一代BMSCs随机分为诱导组和对照组.诱导组加肝细胞生长因子、成纤维生长因子、表皮生长因子、抑瘤素M等进行诱导培养,观察细胞形态,检测甲胎蛋白(AFP)、白蛋白(A1b)、细胞角蛋白18(CK18)、酪氨酸氨基转移酶(TAT)和细胞色素P450 2b9(CYP2b9)的mRNA表达,A1b合成以及A1b和CK18蛋白标记细胞阳性率.结果:诱导组第3天出现多边形细胞,5—7d上皮样细胞呈岛状分布,14 d呈铺路石状.对照组细胞为长梭形.第7,14,21天,诱导组细胞AFP,A1b,CK18 mRNA和A1b蛋白检测阳性;第14,21天,细胞表达TAT和CYP2b9 mRNA.对照组除AFP mRNA呈弱阳性外,其余均为阴性.第7,14,21天,诱导组CK18阳性率分别为71.4%.75.9%,80.6%:A1b阳性率分别为75.0%,79.7%.81.1%.而对照组第7天CK18和A1b阳性率仅2.3%,1.7%,与诱导组相比有显著差异(P_(CK18)=1.97×10~(-5),P_(A11b)=3.08×10~(-6)).结论:BMSCs在体外可以被诱导分化为肝样细胞,诱导率最高可达80%以上.     

体外模拟心肌微环境下骨髓间充质干细胞向心肌样细胞分化的实验研究

目的 :探讨粒细胞集落刺激因子 （G CSF）和干细胞因子 （SCF）预处理对骨髓间充质干细胞 （MSCs）向心肌细胞分化的影响。方法 :MSCs均采用全骨髓法提取 ,通过换液传代逐渐纯化细胞 ,取传 4代的MSCs,在共培养前用DAPI标记 ,心肌细胞在培养的第 3d与MSCs共培养。对照组 :未施加任何干预的MSCs与心肌细胞共培养 ;实验组 :联合使用G CSF和SCF对大鼠在体动员 ,提取其MSCs与心肌细胞共培养。共培养前测定心肌细胞的活力 ,在共培养第 3、4、5d用免疫荧光标记肌钙蛋白T ,分析DAPI MSCs向心肌细胞分化的百分率。结果 :在共培养的第3、4、5d ,G CSF和SCF处理的DAPI MSCs的分化率分别为 （1.2 4± 0 .16 ） %、（3.4 6± 0 .2 1） %、（7.2 1± 0 .11） % ,均显著高于对照组的 0、（1.2 7± 0 .13） %、（1.32± 0 .2 5 ） %。结论 ::G CSF和SCF对MSCs具有促分化作用。     

BrdU作为脂肪干细胞标记示踪法的可行性

目的:研究BrdU标记猪脂肪干细胞(adipose-derived stem cells,ADSCs)的最佳剂量及时间,探讨其作为干细胞标记示踪方法的可行性.方法:自中华实验猪背部提取脂肪组织,采用贴壁法分离培养ADSCs,取第3代细胞以终浓度分别为10、15、20、25及30 μmol/L BrdU进行标记:另一孔不含BrdU作为对照组,分别培养12、24、48、72及96 h.免疫荧光法检测各组细胞BrdU标记率,找出BrdU的最佳标记方法,通过台盼蓝排斥试验、MTT及细胞凋亡检测,观察BrdU对ADSCs生长情况的影响.对第3代的ADSCs采用最佳标记方法后更换普通培养基继续培养,适时传代,连续检测第4、5、6、7、8代ADSCs的BrdU标记率.结果:原代培养的ADSCs的形态主要为长梭形,第3代ADSCs经BrdU标记后胞核呈红色荧光,随浓度的升高及时间的延长,BrdU阳性标记率逐渐升高,以终浓度20μmol/L BrdU标记48 h后阳性率达90%以上,且连续传5代标记率仍达40%.MTT、台盼蓝排斥试验及细胞凋亡检测发现BrdU对ADSCs生长增殖基本无影响.结论:BrdU标记ADSCs的最佳剂量和时间为20 μmol/L和48 h,该方法标记率高,对细胞影响小,可用于动态研究ADSCs在移植体内生长、分化.     

In vitro expansion of gamma delta T cells with anti-myeloma cell activity by Phosphostim and IL-2 in patients with multiple myeloma

T-cell-mediated immunotherapy is a promising therapeutic option for multiple myeloma (MM). Gamma-delta T cells (gammadelta T cells) recognize phosphoantigens and display strong anti-tumour cytotoxicity. The synthetic agonist Phosphostim (bromohydrin pyrophosphate, BrHPP) has been shown to selectively activate Vgamma9Vdelta2 T cells. This study aimed to evaluate the expansion capacity and anti-myeloma cell cytotoxicity of circulating gammadelta T cells from MM patients at different time points throughout the disease, using Phosphostim and interleukin 2 (IL-2). Circulating gammadelta T cell counts in patients with newly diagnosed MM or in relapse did not differ from those in healthy donors. A 14-d culture of peripheral blood mononuclear cells with Phosphostim and IL-2 triggered a 100-fold expansion of gammadelta T cells in 78% of newly diagnosed patients. Gammadelta T cells harvested at the time of haematopoietic progenitor collection or in relapsing patients expanded less efficiently. Expanded gammadelta T cells killed 13/14 myeloma cell lines as well as primary myeloma cells, but not normal CD34 cells. Their killing efficiency was not affected by 2-d IL-2 starvation. This study demonstrated the ability of Phosphostim and IL-2 to expand gammadelta T cells from MM patients, and the efficient and stable killing of human myeloma cells by gd T cells.