Hepatocytic differentiation of mesenchymal stem cells in cocultures with fetal liver cells

AIM： To investigate the hepatocytic differentiation of mesenchymal stem cells （MSCs） in co-cultures with fetal liver cells （FLC） and the possibility to expand differentiated hepatocytic cells. METHODS： MSCs were marked with green fluorescent protein （GFP） by retroviral gene transduction. Clonal marked MSCs were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with stem cell factor （SCF）, hepatocyte growth factor （HGF）, epidermal growth factor （EGF）, and fibroblast growth factor 4 （FGF-4） alone, or in presence of freshly isolated FLC. Cells in co-cultures were harvested, and GFP＋ or GFP- cells were separated using fluorescence activated cell sorting. Reverse transcription-polymerase chain reaction （RT-PCR） for the liver specific markers cytokeratin-18 （CK-18）, albumin, and alpha-fetoprotein （AFP） was performed in different cell populations. RESULTS- Under the specified culture conditions, rat MSCs co-cultured with FLC expressed albumin, CK-18, and AFP-RNA over two weeks. At wk 3, MSCs lost hepatocytic gene expression, probably due to overgrowth of the cocultured FLC. FLC also showed a stable liver specific gene expression in the co-cultures and a very high growth potential. CONCLUSION： The rat MSCs from bone marrow can differentiate hepatocytic cells in the presence of FLC in vitro and the presence of MSCs in co-cultures also prorides a beneficial environment for expansion and differentiation of FLC.

A New Hematopoietic Stimulating Activity Produced by Fetal Liver Cells

Human fetal liver cells were cultured in vitro for 12h and the supernatant(Fetal liver cell conditioned medium,FLCM)was collected.The effects of FLCM ongranulopoiesis were studied.The results show that when combined with colonystimulating factor(CSF),FLCM could significantly stimulate the proliferation of normalmyctoid progenitor cells(CFU-e),and increase ~3H-TdR incorporation into bone mar-row cells.The data suggest that FLCM contains a CSF synergistic activity.

Human CD34loCD133lo fetal liver cells support the expansion of human CD34hiCD133hi hematopoietic stem cells

We have recently discovered a unique CD34loCD133lo cell population in the human fetal liver （FL） that gives rise to cells in the hepatic lineage. In this study, we further characterized the biological functions of FL CD341~CD133~~ cells. Our findings show that these CD341~CD133I~ cells express markers of both endodermal and mesodermal lineages and have the capability to differentiate into hepatocyte and mesenchymal lineage cells by ex vivo differentiation assays. Furthermore, we show that CD34~~CD 133I~ cel Is express growth factors that are important for human hematopoietic stem cell （HSC） expansion： stem cell factor （SCF）, insulin-like growth factor 2 （IGF2）, C-X-C motif chemokine 12 （CXCL12）, and factors in the angiopoietin-like protein family. Co-culture of autologous FL HSCs and allogenic HSCs derived from cord blood with CD34loCD133lo cells supports and expands both types of HSCs.These findings are not only essential for extending our understanding of the HSC niche during the development of embryonic and fetal hematopoiesis but will also potentially benefit adult stem cell transplantations in clinics because expanded HSCs demonstrate the same capacity as primary cells to reconstitute the human immune system and mediate long-term hematopoiesis in vivo. Together,CD34loCD133lo cells not only serve as stem/progenitor cells for liver development but are also an essential component of the HSC niche in the human FL.

EFFECT OF HEPATIC STIMULATOR SUBSTANCE (HSS) EXTRACTED FROM FETAL LIVER ON THE PROLIFERATION OF HUMAN ALEXENDER HEPATOMA CELLS

It's reported that hepatic stimulator substance (HSS) was extracte from the fetal liver of 4 - 6 months of fetus, and that the effect of HSS on the proliferation of human Alexender hepatoma cells was studied in this paper. The results showed that proliferation of Alexender cells varied with the amount of HSS in the culture medium, and the former was positively correlated with the latter significantly (P<0. 01). The study indicated that HSS from the fetal liver can stimulate the proliferation of human Alexender hepatoma cells.

Effects of restrictions on maternal feed intake on the immune indexes of umbilical cord blood and liver Toll-like receptor signaling pathways in fetal goats during pregnancy

Background: Liver has important immune function during fetal development and after birth.However,the effect of maternal malnutrition on immune function of the fetal liver is rarely reported.In this study,twelve pregnant goats(Xiangdong black goat,at d 45 of gestation) were assigned to the control group(fed 100% of nutritional requirements) and the restriction group(fed 60% of the intake of the control group) during gestation from d 55 to100.Fetal goats were harvested at d 100 of gestation and immune indexes and amino acid profiles of the umbilical cord blood and liver Toll-like receptors(TLRs) signaling pathways were measured.Results: Maternal body weight in the restriction group was lower than the control group(P < 0.05).Maternal feed intake restriction decreased(P < 0.05) heart weight,heart index,alkaline phosphatase and serum amyloid protein A in the umbilical cord blood(UCB).Moreover,only histidine was decreased in the restricted group(P = 0.084),and there were no differences in other amino acids contents in the UCB between the two groups(P > 0.05).The TLR2 and TLR4 mRNA expression in the fetal liver in the restriction group was greater(P < 0.05) than that in the control group.Furthermore,the mRNA expression levels of myeloid differentiation primary response 88(MyD88),TNF receptor associated factor 6,nuclear factor kappa B subunit 1,NFKB inhibitor alpha,IFN-β,TGF-β,TNF-α and IL-1β in the restricted group were upregulated(P < 0.05),and the expression of TLR3(P = 0.099) tended to be higher in the restricted group.However,protein levels of TLR2,TLR4,IκBα,phosphorylated IκBα,phosphorylated IκBα/total IκBα,TRIF and MyD88 were not affected(P > 0.05) by maternal intake restriction.Conclusions: These results revealed that the restriction of maternal feed intake influenced the development of heart and hepatic protein synthesis at the acute phase of fetal goats and upregulated the mRNA expression of genes involved in MyD88-dependent signaling pathways and of target cytokines.

TRAITEMENT DE L'HEPATITE VIRALE FULMINANTE PAR TRANSPLANTATION DES CELLULES HEPATIQUES FOETALES HUMAINES——ETUDE PRELIMINAIRE SUR 8 CAS

The authors achieved a clinical study on the treatment of fulminant viral hepatitis by the transplantation of human fetal liver cells. 47fetal livers were used for 8 patients with a survival of 6 cases. The side-effects of this new therapy were analysed and the mechanism of action of fetal liver cells discussed.

Blocking effects of siRNA on VEGF expression in human colorectal cancer cells

AIM:To investigate the expression of vascular endothelial cell growth factor (VEGF) and its receptors Fmslike tyrosine kinase 1 (FLT-1) and fetal liver kinase 1 (FLK-1) in colorectal carcinoma (CRC),and the blocking effects of small interfering RNAs (siRNAs) on VEGF expression in human colorectal cancer HCT116 cells.METHODS:Immunohistochemical staining for VEGF,FLT-1 and FLK-1 proteins was performed in 82 cases of CRC and 14 normal colorectal mucosae.A siRNA targeting VEGF was synthesized and transfected into HCT116 cells using lipofectamine 2000.Immunocytochemical staining and Western blotting analyses were performed to detect the expression of VEGF protein.The suppressive effect of the siRNA on cell proliferation was detected using the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltertrazolium bromide (MTT) assay.Cellular apoptosis was detected using flow cytometry (FCM).RESULTS:The expression of VEGF,FLT-1 and FLK-1 in tumor tissues was significantly higher than that in normal tissues (P=0.008,P=0.000,P=0.000).The expression of VEGF was positively correlated with both lymph node metastasis and clinical stage (P=0.009 and P=0.025,respectively).Immunocytochemistry showed that the expression of VEGF was weakly positive and Western blotting indicated a significant reduction in VEGF-siRNA cell protein levels.VEGF-siRNA cell growth inhibition was assessed by the MTT assay,and the tumor cell proliferation rate was significantly different at 24,48,and 72 h after transfection.FCM results showed that the VEGF-siRNA group had an apparent aneuploid peak.CONCLUSION:VEGF,FLT-1 and FLK-1 are associated with colorectal carcinogenesis.siRNA silencing of the VEGF gene suppresses proliferation,and induces apoptosis in HCT116 cells.The results suggest that VEGF may be a new gene therapy target for colorectal cancer.

Chimera formation of platelet GPⅡb Bak a/b by intrauterine transplantation of fetal liver stem cells

Abstract:Objective To investigate whether artificial heterozygous chimeras of platelets can be established by intrauterine transplantation of fetal liver stem cells and evaluate its potential use for the treatment of Glanzmann thrombasthenia.Methods Platelet glycoprotein (GP) Ⅱb Bak a/b (or GPⅡb Ⅰle843Ser) was used as a genetic marker. A homozygous 16-week-old Bak a/a fetus (as donor) and a homozygous 16.5-week-old Bak b/b fetus (as recipient) were screened from 42 pregnant women hospitalized for abortion. PCR with allele specific primers and FOK Ⅰ digestion based on PCR products were used. Aborted donor fetal liver cell suspensions were prepared and intrauterine transplantation was carried out by infusion of 4?ml fetal liver cells (22×105) into the recipient umbilical vein under ultrasonic visualization.Results At gestation termination (abortion), 21 days after transplantation, chimera GPⅡb Bak a/b of the recipient were detected by FOK 1 digestion based on PCR from DNA and RT-PCR from platelet RNA. Conclusion Intrauterine transplantation of fetal liver cell may provide an effective way for curing GT or other inherited diseases.

妊娠期肝内胆汁淤积症患者血清甘胆酸与肝生化指标、炎性细胞因子水平变化相关性分析

目的 分析妊娠期肝内胆汁淤积症患者血清甘胆酸与肝生化指标、炎性细胞因子水平变化相关性。方法 前瞻性选取2018年1月至2021年1月乐山市妇女儿童医院妇产科收治的104例妊娠期肝内胆汁淤积症(ICP)患者作为研究对象,根据ICP的分度标准分为轻度ICP组(n=79)和重度ICP组(n=25),选取同期80名健康产妇作为对照组。对3组产妇的肝生化指标[甘胆酸、丙氨酸转移酶(ALT)、天冬氨酸转移酶(AST)]、炎性细胞因子[淋巴细胞(LY)、中性粒细胞(NE)、血小板计数(PLT)、白细胞介素18(IL^(-1)8)、肿瘤坏死因子-α(TNF-α)]水平变化及胎儿结局进行记录,并进行相关性分析。结果 轻度ICP组及重度ICP组产妇的甘胆酸、ALT、AST均明显高于对照组,重度ICP组甘胆酸含量显著高于轻度ICP组,差异均有统计学意义(P<0.05)。轻度ICP组及重度ICP组产妇的血清LY、NE、IL^(-1)8及TNF-α水平均显著高于对照组,血清PLT水平显著低于对照组,差异均有统计学意义(P<0.05);重度ICP组血清IL^(-1)8、TNF-α均明显高于轻度ICP组,差异均有统计学意义(P<0.05),重度ICP组的血清LY、NE、PLT水平与轻度ICP组比较,差异均无统计学意义(P>0.05)。重度ICP组的新生儿出生体重最低,分娩孕周最少,新生儿Apgar评分最低,其次为轻度ICP组,对照组最高,差异有统计学意义(P<0.05)。重度ICP组羊水粪染率为52.00%,新生儿黄疸率为44.00%,均明显高于轻度ICP组(29.11%、25.32%)和对照组(5.00%、10.00%),差异均有统计学意义(P<0.05)。经Spearman相关性分析,ICP孕妇血清甘胆酸水平与脐动脉S/D比值呈正相关(r=0.851,P<0.05),与ALT水平呈正相关(r=0.946,P<0.05),与新生儿Apgar评分呈负相关(r=-0.885,P<0.05)。结论 随着ICP患者体内甘胆酸水平越高,ALT、AST、炎性细胞因子和脐动脉S/D比值越高,可能导致ICP患者的不良胎儿结局。肝生化指标及血清炎性细胞因子在ICP的发生、发展中发挥重要作用,但对于病情程度的分度作用不明显。

体外诱导成熟树突状细胞的研究

目的 :探讨在体外从干细胞中诱导出成熟DC的适宜环境。方法 :分别将人胎肝、骨髓和脾细胞以及小鼠骨髓和脾细胞在体外用GM CSF和TNF α诱导 ,观察了第 3、5、7天DC的收获情况。进一步用S P免疫细胞化学染色检测了mBmDC和fLDC有关分子表达。结果 :在体外通过GM CSF和TNF α的作用 ,小鼠骨髓、人胎肝、骨髓细胞呈典型的毛刺状胞浆突起 ,第5天的收获率分别为 :39 5 %、6 7 2 %、12 9% ,而基本不能从脾细胞中诱导出成熟DC ,获得的DC能与MAbCD80、MAbCD40呈强阳性反应。结论 :在GM CSF和TNF α的共同作用下 ,能在体外从人胎肝、骨髓和小鼠骨髓干细胞中获得成熟DC ,其DC能表达高水平的B7 1和CD40分子 ,这为大量获取DC提供了一种简便可行的手段 ,为研究DC的生物学特征及其抗原提呈功能提供了丰富的材料 。

干细胞样肝原始细胞的分离和鉴定

目的 :证实小鼠胎肝中肝干细胞的存在。方法 :小鼠胎肝细胞的分离培养和免疫细胞化学等。结果 :从小鼠胎肝组织中成功地分离得到了AFP、CD34及Albumin等特异性分子标记阳性、并呈集落样生长的细胞系。结论 :小鼠胎肝中存在具有干细胞特性的原始细胞 。

胎儿骨髓和肝脏间充质干细胞的表型和生物学性状研究

为研究胎儿骨髓和肝脏间充质干细胞的表型和生物学性状 ,取胎龄为 4 - 5个月水囊引产胎儿 ,将骨髓和肝脏细胞在SF(含 2 %FCS)培养基中培养 ,进行电镜观察 ,测定生长曲线 ,用流式细胞术对培养细胞进行表型测定 ,细胞周期分析 ,用SA方法测定Ⅰ ,Ⅲ型胶原和vWF因子表达。结果表明 :从胎儿骨髓和肝脏培养出的间充质干细胞 ,两者在形态学、生长特性、免疫表型上是相似的 ,肝脏间充质干细胞有更好的支持造血的功能。结论提示 ,从胎儿骨髓和肝脏可分离培养出间充质干细胞 ,在体外有效扩增且保持其低分化状态。

体外诱导小鼠胎肝间充质干细胞向胰岛B样细胞分化的研究

目的:体外分离和定向诱导小鼠胎肝间充质干细胞向胰岛B样细胞分化。方法:无菌条件下从正常C57BL／6J胎鼠肝中分离出间充质干细胞,体外培养传3代后用高浓度葡萄糖培养基以及碱性纤维生长因子(basic fihroblast growth factor,bFGF)和尼克酰胺诱导分化,观察胎肝间充质干细胞诱导前后形态变化;用RT-PCR检测细胞诱导前后胰十二指肠同源异型基因盒1(pancreatic duodenal homeobox-1,PDX-1)、胰岛素原1(proinsulin-1,INS-1)、葡萄糖转运子2(glucose transporter-2,GLUT-2)表达情况;胰岛素免疫细胞化学染色鉴定诱导后细胞胰岛素的表达;在形成胰岛样细胞簇后,用双硫腙做胰岛B细胞特异性染色。结果:RT-PCR显示诱导5 d后PDX-1、INS-1、GLUT-2均有表达,而诱导前的细胞则没有检测到表达;胰岛素免疫细胞化学表明细胞簇内的细胞胰岛素染色强阳性;细胞簇双硫腙染色阳性(每个T-25培养瓶有80-120个)。结论:从胎肝中分离出的间充质干细胞在体外可以定向诱导分化为胰岛B样细胞。

胎儿肝脏中一种抑制HL-60细胞生长的因子初步研究

胎儿肝脏中存在着两类抑制HL-60细胞生长的抑制物,一类是精氨酸酶,它是一类非特异性的细胞毒剂,在我们的实验条件下,不仅对HL-60细胞,而且对正常人骨髓CFU-GM也具有相似的抑制细胞生长的毒性作用。此外,还存在着一类较小分子的抑制物,它对HL-60细胞生长的抑制作用明显高于对人骨髓CFU-GM的作用,因此,在一定程度上,这是一类对HL-60细胞生长具有选择性作用的抑制物。

小鼠胎肝和骨髓细胞基因表达差异的比较研究

造血发育经历了从卵黄囊到胎肝、胎脾并最终定位于骨髓的复杂过程。虽然已有部分研究发现决定这一迁移过程的重要因素是造血微环境 ,但缺乏对不同造血器官微环境差别的系统性比较研究。为了探讨胎肝与成年骨髓造血微环境差别的分子基础 ,对小鼠胎肝和骨髓细胞RNA进行cDNA微阵列 (cDNAmicroarray)杂交 ,以生物信息学方法分析杂交结果 ,并以RT PCR和Northernblot对杂交结果进行进一步验证。结果表明 ,在 588种具有重要功能的已知基因中 ,二者相比 ,骨髓高表达的基因有 65种 ,胎肝高表达的基因有 13 1种。进一步分析发现骨髓高表达的基因中与造血相关的基因有 3 9种 ,胎肝高表达的基因中与造血相关的有 71种 ,分别占差异基因群的60 %和 54%。RT PCR和Northernblot验证的结果表明 ,CD18、CD44及PSGL 1基因在骨髓中高表达而在胎肝中低表达或不表达 ,此结果与微阵列杂交结果相符。同时还发现 ,CD18和CD44基因在胎肝中的表达水平随胎龄增加呈下调趋势。结论 :胎肝与骨髓细胞的基因表达谱显著不同 ,其中某些基因的表达随发育阶段不同而变化。这些基因的差异性表达 ,尤其是与造血细胞发育、迁移、植入等密切相关基因的差别性表达 ,可能是胎肝造血兴衰。

鼠胚胎肝细胞在体外L-聚乳酸支架上的长期培养及其成熟化诱导

目的 研究三维生物降解材料 L-聚乳酸 (PL L A)对胚胎肝细胞的支持作用及制瘤素 M(OSM)、尼克酰胺 (NA)和二甲亚砜 (DMSO)在胚胎肝细胞成熟化中的作用 ,探讨胚胎肝细胞在肝脏组织工程中应用的可行性。方法 将两步法分离获得的 E14 .5 - C5 7BL/6 Cr Slc小鼠胚胎肝细胞接种于具有三维立体多孔结构的 PL L A支架后 ,在含有及不含有 OSM、NA和 DMSO的 Williams'E条件培养基中进行原代长期培养 ,了解其增殖能力、形态及功能变化。 结果 与单层培养相比 ,三维立体 PL L A支架培养胚胎肝细胞其细胞数量与白蛋白的分泌量均明显增加 ;单层培养中 ,单独添加 OSM组白蛋白分泌仅有轻微增加 ,但 PL L A培养中 OSM组的胚胎肝细胞白蛋白分泌量明显增加 ;无论是单层培养或 PL L A培养 ,OSM/NA/DMSO组白蛋白分泌均明显增加。 结论 三维 PL L A支架是胚胎肝细胞培养的良好支持物 ;OSM、NA和 DMSO可明显促进肝脏实质细胞在体外的成熟。

促红细胞生成素基因修饰的胎肝基质细胞促进脐血CD34+细胞向红系分化

通过重组慢病毒系统感染人胎肝基质细胞(fetal liver stromal cells,FLSCs),建立了能够稳定高效表达促红细胞生成素(erythropoietin,EPO)的细胞株EPO/FLSCs.从胎儿肝脏克隆EPO基因,构建重组慢病毒EPO的表达载体,感染FLSCs,根据荧光表达强弱进行流式分选,获得能够继续稳定传代的高表达EPO基因的FLSCs,RT-PCR和ELISA结果证实,细胞株中的EPO基因稳定表达.RT-PCR结果显示,FLSCs的EPO在mRNA水平的表达分别是未转染FLSCs和转染空载体FLSCs的5.63倍和5.71倍.ELISA法检测了转染重组慢病毒EPO表达载体的FLSCs EPO蛋白表达水平,结果显示EPO蛋白的表达水平也明显升高.收集EPO/FLSCs的条件培养基,体外诱导脐血CD34+细胞向造血细胞分化,结果显示向红系定向分化的细胞比例明显居多,有可能为临床细胞治疗提供稳定、高质量的细胞来源.

人胎肝中肝细胞生长因子生物活性的研究

人胎肝细胞裂解液经膜超滤,在分子量10～30kD组分中可检测出人肝细胞生长因子(hHGF)活性。hHGF为一热稳定的蛋白质或多肽类物质。它可特异地刺激肝来源细胞~3H-TdR掺入的增加,并且存在量效依赖关系,而对非肝来源细胞的DNA合成无刺激作用。hHGF的生物活性及理化性质与某些已知因子,如胰岛素、胰高血糖素、血小板来源的生长因子、表皮生长因子及增殖刺激因子等有所不同。

人免疫重建SCID小鼠的研究

４２只不渗漏ＳＣＩＤ小鼠分别腹腔注射经冷冻、复苏的胎肝或胎肝加胎胸腺细胞，每鼠２×１０７活细胞，建立人胎肝细胞ＳＣＩＤ小鼠模型Ⅰ和Ⅱ，研究人免疫系统。用人肝癌细胞（ＨＨＣＣ）免疫，ＳＣＩＤ鼠出现初始免疫答应，血清人ＩｇＧ平均滴度分别达到５１３．０±８４．２ｎｇ／ｍｌ和７１９．７±２０１．６ｎｇ／ｍｌ，ＩｇＧ峰值分别出现在免疫重建后１０～１２和１０～１４周，特异性抗ＨＨＣＣ抗体滴度分别达到１∶７０．４±３５．０５和１∶２９４．４±１６８．５２，免疫重建后７～８周龄，ＡＢＣ法免疫组化染色，免疫鼠模型肝、脾中可检出标记人的ＣＤ３＋、ＣＤ２０＋Ｔ和Ｂ淋巴细胞克隆和细胞岛。流式细胞仪检测了抗原免疫组和模型组外周血、脾脏、肝脏的人ＣＤ３＋、ＣＤ４＋、ＣＤ８＋、ＣＤ１９＋、ＣＤ２０＋标记的淋巴细胞数，其中标记ＣＤ２０＋淋巴细胞平均值外周血３．１２±３．０３％、脾脏１．４±０．２０％、肝脏２．３２±１．４９％。而无抗原免疫的模型组在肝脏仅有微量或检测不到人标记淋巴细胞。

胎肝条件培养液体外诱导人骨髓间充质干细胞定向分化为造血细胞的研究

目的探讨人骨髓间充质干细胞(hMSCs)体外造血分化潜能。方法选用孕125-145d(125-145dpc)的昆明小鼠,分别制备小鼠胎肝基质细胞条件培养液(FLSC-CM)及胚胎成纤维细胞饲养层(FD),将体外扩增的CD34-CD45-hMSCs分别接种于含FLSC-CM、FD和IL-6及SCF组合的培养体系中,培养7d后,通过形态学、表型、粒-单/巨噬细胞系集落培养(CFU-GM)对分化细胞进行鉴定。结果hMSCs与FLSC-CM共培养组产生的非贴壁细胞明显增多,形态类似于单核或小淋巴细胞,部分细胞可表达人造血细胞特异性表面分子(CD34和CD45),在含人粒-单集落刺激因子(GM-CSF)的甲基纤维素培养体系中能够形成CFU-GM,而FD和IL-6+SCF诱导组无上述作用。结论FLSC-CM可诱导CD34-CD45-hMSCs分化为造血细胞,提示hMSCs具有体外造血分化潜能。