Thy1-positive bone marrow stem cells express liver-specific genes in vitro and can mature into hepatocytes in vivo

The bone marrow contains stem cells that have the potential to differentiate into a variety of organ-specific mature cells, including the liver and the pancreas. Recently, the origin of hepatic progenitors and hepatocytes was identified to be the bone marrow. However, evidence that describes which cells, among all bone marrow cells, differentiate into hepatocytes, has not yet been presented. Based on recent reports, hematopoietic and hepatic stem cells share characteristic markers such as CD34, c-kit, and Thy1. In particular, both hematopoietic and hepatic stem cells express the Thy1 antigen. We investigated whether rat Thy1-positive bone marrow cells express liver-specific genes in vitro, and whether transplanted Thy1 BM cells differentiate into mature hepatocytes in vivo. For collection of Thy1 cells from bone marrow, FITC-conjugated anti-Thy1.1 monoclonal antibody was used with a Fluorescence-Activated Cell Sorter system. A coculture system of 2 separate layers was used for culture of Thy bone marrow cells. Cultured Thy1 cells expressed albumin protein, which was analyzed by immunofluorescent staining. Thy1 bone marrow cells obtained from wild-type dipeptidyl peptidase IV (DPPIV(+)) male rat were directly transplanted into the injured liver of DPPIV mutant (DPPIV(−)) Fisher 344 female rats and differentiated into mature hepatocytes in recipient liver on 60 days. Donor-derived hepatocytes were confirmed by DPPIV staining and Y-chromsome in situ hybridization. Our results suggest that Thy1-positive bone marrow cells have the potential to generate liver-specific genes in vitro and can differentiate into mature hepatocytes in adult liver in vivo. Thy1-positive bone marrow stem cells may represent preexisting hepatocyte-specific stem cells.     

胎肝来源间充质干细胞的分离、培养与多向分化

目的从胎肝中分离培养间充质下细胞，并研究其牛物学特性。方法用优化的方法从胎肝中分离获得间充质干细胞。利用流式细胞仪分析细胞表型和细胞周期分布，并体外诱导成骨、成脂肪和成肝组织细胞分化。并用染色方法鉴定成骨、成脂肪分化结合形态学方法和RT-PCR方法鉴定成肝组织分化结果。结果从胎肝中分离培养的细胞为成纤维样，贴壁生长．表型相对均一，表面标志为CD90，CD44，CD147，而CD34，CD45，HLA-DR，具有向肝组织分化的潜能，并可向成骨和成脂肪分化。结论从胎肝中可分离培养得到具有多向分化潜能的间充质干细胞。     

Isolation,biochemical characterization,and culture of lung type II cells of the rat

A method is described for the isolation of rat lung epithelial Type II cells using trypsin digestion of tissue to release cells for subsequent separation by Percoll gradient centrifugation. Both the concentration of trypsin and the age (body weight) of the rat affect the yield from primary digestion and the final number of Type II cells obtained. A lung weighing 1 g from a 200 g rat yields approximately 30 × 10⁶ washed Type II cells (approximately 25% of the total estimated lung population). These cells have a plating efficiency of 40–50% after 48 h of culture. The cells have a high alkaline to acid phosphatase ratio (usually >4.0) compared with that of alveolar macrophages (0.1) and accumulate putrescine by an active transport mechanism with an apparent K_M between 8 and 14 μM. Together with studies of [³H]thymidine uptake into DNA, which is maximal between 48 and 72 h of culture, these quantitative measurements form a good basis for investigating the interactions between a number of chemical agents and Type II cells in vitro.     

Isolation and characterization of rat fetal Sertoli cells

Sertoli cells were prepared from fetal rats, aged 15, 18, and 21 days. Cultures of these cells can be prepared at a purity of 85% by a method that is widely used to prepare the same cells from postnatal rats. The fetal cells are identical in appearance to postnatal Sertoli cells. Fetal Sertoli cells round up in response to (Bu)2cAMP, but not in response to FSH. Protein synthesis in the cells is not stimulated by (Bu)2cAMP or FSH. However, incorporation of [35S]methionine into secreted proteins appearing in the incubation medium is stimulated by the cyclic nucleotide, but not by FSH. Reproducible patterns for the incorporation of [35S]methionine into cellular and secreted proteins are presented as autoradiograms of one- and two-dimensional electrophoretograms. These autoradiograms show that the response of secreted proteins to (Bu)2cAMP is a general one; most or all proteins participate in the response. No clear differences were observed in the nature of the proteins synthesized when cells from fetal rats of 15, 18, and 21 days of age were compared. Fetal Sertoli cells produced approximately 2 nmol lactate/10(6) cells.h, which is approximately one fifth of the amount produced by postnatal cells. Lactate production was increased by the addition of FSH or (Bu)2cAMP to the medium. Fetal Sertoli cells also synthesize androgen-binding protein, and this activity is not increased by either FSH or (Bu)2cAMP.     

Isolation and characterization of epithelial progenitor cells from human fetal liver

Aim: Hepatic progenitor cells can serve as an alternative source of hepatocytes for the treatment of liver diseases. Methods: We isolated and expanded the epithelial progenitor cells (EPC) from the human fetal liver and investigated the differentiation of EPC into hepatic cells by fluorescence-activated cell sorter (FACS), real-time polymerase chain reaction (PCR), immunofluorescence assay, western blotting, and periodic acid-Schiff staining. Results: Isolated EPC possessed highly proliferative ability and subpassaged for more than 25 passages. Real-time PCR showed that EPC expressed liver epithelial markers (cytokeratin [CK]8 and CK18) and biliary-specific markers (CK7 and CK19). FACS analysis indicated that these cells were positive for CD117, CD147, CD90, CD44, human leucocyte antigen class I and CD71, but negative for CD34 and CD45. The EPCpossessed multipotential indicated by differentiating into osteoblasts and adipocytes; when subjected to the hepatic differentiation condition, EPC could be induced to hepatocyte-like cells, which expressed albumin, alpha-fetoprotein, and CK18 proteins. Two months after EPC transplantation, we observed that the grafted cells differentiated into hepatocyte-like cells and there was no observable tumor mass. Conclusion: We have isolated and characterized the human fetal liver-derived EPC and these cells may serve as an ideal cell source for cell-replacement therapy of diseased livers.     

大鼠肝卵圆细胞的分离培养及脾内移植研究

目的 观察肝卵圆细胞在同种异体大鼠脾内移植的演变结果,为肝干细胞移植治疗临床肝功能衰竭提供实验依据。方法 采用改进的梯度离心法分离肝卵圆细胞,体外培养鉴定后移植入2/3肝切除的同种异体大鼠脾脏内。结果 每只模型大鼠肝脏中可分离获得约1.69×10~5/ml肝卵圆细胞。体外培养的肝卵圆细胞呈现上皮细胞的生长特点,对OV6、细胞角蛋白19及甲胎蛋白染色呈阳性反应,对白细胞共同抗原染色呈阴性反应。肝卵圆细胞植入异体大鼠脾脏内可形成岛屿状肝组织结构,形成“肝化脾”。结论 大鼠肝卵圆细胞具有肝干细胞的生物学特征,在一定条件下可分化为肝细胞及胆管上皮细胞。     

人胎肝干细胞体外分离、培养及鉴定

研究人胎肝干细胞体外分离纯化方法，并对其进行初步鉴定及生物学特性分析。采用胶原酶消化、重力沉降及密度梯度离心方法分离人胎肝干细胞，通过免疫细胞化学方法对其进行初步鉴定，以及应用流式细胞仪等对其生长状况进行评估。所获得的原代细胞共传8代，细胞呈小梭形或三角形，体积较小，胞核较大，而胞浆较少；第4代细胞中进入生长期的细胞约占88．2％；免疫细胞化学染色显示细胞胞质中ALB、CK19染色阳性。人胎肝中存在具有肝干细胞特征的细胞，它们可能会成为细胞移植及肝移植良好的细胞资源。     

大鼠胰星状细胞的分离与培养

目的　建立大鼠胰星状细胞 (pancreatic stellate cells,PSCs)的分离培养方法。方法　大鼠胰腺组织经胶原酶和链霉蛋白酶 E消化后 ,用 Nycodenz不连续密度梯度离心法分离 PSC,在 32 8nm紫外光激发下观察细胞的自发荧光现象 ,并以免疫组化技术检测结蛋白 (desmin)、神经胶质原纤维酸性蛋白 (glial fibrillary acidic protein,GFAP)和α-平滑肌动蛋白 (α- sm ooth m uscle actin,α- SMA )的表达 ,同时观察培养细胞的形态和生长特性。结果　新鲜分离的大鼠 PSCs产率、活力和纯度分别约为 2 .5 ×10 6 /g胰腺、95 %和 90 %。培养的 PSCs可自发活化 ,表达 α- SMA,细胞由静止型转化为肌成纤维样细胞表型。原代培养 10天后细胞纯度 >95 % ,传代培养后细胞纯度可达 99%以上。结论　利用 Nycodenz密度梯度离心方法可成功分离大鼠 PSCs,其细胞产率、活力和纯度均可满足体外研究需要。     

Isolation and primary culture of rat Kupffer cells

The aim of this study was to describe a reproducible method for the isolation, purification and primary culture of rat Kupffer cells. Kupffer cells were isolated following sequential pronase/collagenase digestion of the liver and enrichment of a non-parenchymal cell fraction by a single-density gradient centrifugation step using 30% metrizamide. Kupffer cells were isolated and further purified from this cell fraction by centrifugal elutriation. Kupffer cells were isolated at 1017 g at 48–110 mL/min. All Kupffer cell fractions exhibited phagocytosis of 3 μm latex beads. Kupffer cell fractions isolated at 48 and 60 mL/min were predominantly ED2 negative while later fractions (80–110 mL/min) were ED2 positive. Kupffer cells were adherent in culture after 2 h. This method for Kupffer cell isolation resulted in a yield of 80–120 times 10⁶ Kupffer cells per liver.     

Promoted differentiation of cynomolgus monkey ES cells into hepatocyte-like cells by co-culture with mouse fetal liver-derived cells

INTRODUCTION Embryonic stem (ES) cells are self-renewing, pluripotent cells derived from the inner cell masses of preimplantation blastocysts[1,2]. They can be expanded without limit and retain a potential to differentiate into various somatic cell types …     

Transplantation of fetal liver of different ages in the rat

Summary This study investigates the effect of fetal liver transplantation in reconstituting hemopoiesis in supralethally irradiated rats. Different cell doses of fetuses at the embryonic age of 15 and 18 days were compared to equivalent cell doses of adult bone marrow cells. Although the frequency of engraftment ranged between 75 and 100% in all the groups of animals studied, the survival rate at 30 days after TBI did not show any significant difference between the fetal liver and the bone marrow treated recipients. The bone marrow transplants performed in littermate rats almost doubled the percentage of survivors at 30 days and showed a cell dose relationship suggesting that, in the closed colony of random-bred rats used, the mortality after bone marrow and fetal liver transplants was mainly due to graft-versus-host-disease. Antibiotic prophylaxis and treatment during the experiment did not modify the results in a separate group of fetal liver and bone marrow transplanted rats. In the rat model system used in this set of experiments fetal liver did not reveal any advantage over bone marrow transplantation.Supported by CNR N 80.00486 Rome, Italy, and Stiftung Volkswagenwerk Hannover, Federal Republic of Germany     

CD34+ cells derived from fetal liver contained a high proportion of immature megakaryocytic progenitor cells

Endoreplication and maturation of the megakaryocyte (MK) may be retarded or delayed during ontogenesis. In this study, CD34+ cells were isolated from both human fetal liver and adult bone marrow and incubated with thrombopoietin (TPO). The cell number, morphological characteristics, platelet-associated antigen phenotype, maturation stage and DNA ploidy of CD41+ cells were examined from day 0 to day 12 in culture. 1) TPO stimulated the proliferation of fetal liver (FL)-derived CD34+ cells with a mean 73.14-fold increase of CD41+ cells after 12 d in culture. Adult BM-derived CD34+ cells increased only slightly, with a mean 8.18-fold increase of CD41+ cells. 2) Although the membrane phenotype of both FL CD34+-derived MKs and BM CD34+ -derived MKs analyzed with CD41a, CD42a, CD61 and CD34 were similar, all FL CD34+-derived MKs were in maturation stage I and II and in low ploidy (<4N) class. By comparison, BM CD34+ MKs possessed 15% MKs in maturation stage III and IV and with 23% MKs in high ploidy class ( > 4N). 3) Most of cultured FL-derived CD34+ cells did not have a well developed demarcation system (DM) and numerous alpha-granules after 12 d incubation. von Willebrand factor (vWF) appeared earlier on the cultured BM-derived CD34+ cells than on FL-derived CD34+ cells. 4) The expression of both cyclin E and cyclin B1 progressively increased in FL CD34+ cells induced by TPO during 12 d in culture. 5) The expression of cyclin D1 gradually decreased in FL CD34+ cells induced by TPO over 12 d incubation. 6) Immunocytochemical analysis showed that cyclin D3 was detected only in cytoplasm of cultured FL-derived CD34+ cells, whereas in both cytoplasm and nuclei of cultured BM-derived CD34+ cells. These data suggest that FL-derived CD34+ cells contain a high proportion of immature megakaryocytic progenitor cells. It further suggests that TPO can push these progenitor cells into proliferation by upregulating the expression of cyclins B1 and E, and drive a high proportion of cells into megakaryocytic lineage.     

大鼠骨髓间充质干细胞的分离培养纯化与鉴定

目的:探讨骨髓间充质干细胞(BMSCs)体外获取及培养增殖的方法并鉴定。方法:用密度梯度离心法结合贴壁培养法分离、纯化培养大鼠BMSCs,测定生长曲线,流式细胞仪鉴定,免疫细胞化学检测。结果:密度梯度离心结合贴壁培养法能有效分离纯化大鼠BMSCs,P2、4、6代细胞生长曲线基本一致,增值能力强,呈均一成纤维样细胞,P3代以后细胞均一地表达细胞表面抗原CD44、CD90,不表达CD34,弱表达CD11b/c,细胞表达Connexin43。结论:本实验建立了一种体外稳定培养扩增大鼠BMSCs的方法,培养的细胞成分单一,适用于对BMSCs进一步的应用研究。     

Neonatal rat islets of Langerhans and fetal rat pancreas Isolation,immunohistochemical, functional,and autoradiographic evaluation

The aim of this study was to develop an optimal isolation technique for neonatal rat islets of Langerhans, to perform functional evaluation in vitro, to evaluate immunohistochemically isolated rat islets and fetal rat pancreata after a variable period of culture, and to study growth potentials by means of autoradiography. The islets were isolated using minor modifications of standard procedures including collagenase and DNase. Islets were separated on a discontinuous Percoll gradient. The maximum yield of islets amounted to 240 per pancreas. Fetal pancreata from rats were cultured under similar conditions as neonatal islets to compare their insulin secretory capacity after different periods of culture. The insulin secretion increased gradually, and isolated islets achieved a similar secretion potential to adult rat islets. The mitotic activity of both islets and fetal pancreata was confirmed using tritiated thymidine. The isolation procedure was found suitable for producing well-functioning islets, which could be kept in culture for a period of about 1 month without deterioration in their insulin secretory capacity. The gradual increase in insulin secretory capacity of islets and fetal pancreata was due, in part, to hyperplasia and not just hypertrophia. Autoradiographical evaluation revealed a high mitotic activity after culture, in particular of fetal pancreata. Fetal pancreata cultured for about 10 days showed a phenomenon of budding endocrine cells at the organ surface. A high mitotic activity was found in these buds.     

大鼠肝贮脂细胞及Kupffer细胞的分离培养和鉴定

目的 肝贮脂细胞是肝纤维化发生机制研究的细胞学热点,该细胞的分离、培养具有重要意义。 方法 参考Friedman等的不连续密度梯度离心法,首次采用高分子聚蔗糖、泛影葡胺作为不连续密度梯度分层液分离细胞。 结果 本法成功地分离得到肝贮脂细胞和Kupffer细胞。 结论 本法经济、简便、可靠,细胞纯度高。     

NDRG1在原发性肝细胞癌及胎肝中的表达及意义

目的:探讨NDRG1在原发性肝细胞癌(HCC)及胎肝组织中的表达及其意义.方法:收集2002-01/2008-12广州市第一人民医院手术切除的肝细胞癌标本81例. 所有患者术前未行放疗和化疗; 25例胎肝组织, 取自不同月份流产或引产的胎儿(4、5、6、7、8 mo胎儿各5例); 另选43例癌旁组织, 10例肝硬化组织, 9例正常肝组织(移植肝), 8例原发癌转移灶组织作为对照. 观察肝脏组织病理形态特征, 并用免疫组织化学EnVison法检测NDRG1的表达.结果:NDRG1在正常肝组织中呈强阳性表达, 平均吸光度值为0.206±0.056, 随着肿瘤的发生, 在癌旁组织中有减弱(0.176±0.083),在HCC中表达明显减弱(0.128±0.096), 在转移灶中表达最低(0.059±0.051), 而在胎肝组织中表达亦较低(0.059±0.074). 各组总体差异均有统计学意义(F = 33.669, P <0.05). HCC与患者年龄、性别、肝炎病史、肝硬化、肿瘤大小、AFP值、HbsAg、淋巴结转移及有无远处转移、肿瘤分型、Child-Pugh分级、TNM分期、CLIP分期均无关(P >0.05), 但与肿瘤的Edmondson分级有关(F = 2.881, P <0.05).结论:NDRG1在HCC中低表达, 并且随着肿瘤的发生发展, 表达量逐渐降低. NDRG1可能对HCC起着抑制作用, 提示该基因可望成为早期预测肝癌转移的分子生物学标志物之一.     

ABC转运蛋白在大鼠肝脏卵圆细胞中的表达

目的研究ABC转运蛋白基因家族的三个主要成员MDR1、MRP1和Bcrp1基因在大鼠肝脏卵圆细胞中的表达及意义。方法建立大鼠2-乙酰氨基芴／三分之二肝切除模型，两步胶原酶灌注结合Percoll密度梯度离心分离大鼠肝脏卯圆细胞和肝细胞，采用免疫组织化学染色检测大鼠肝脏组织中MDR1、MRP1、Bcrp1转运蛋白的表达；采用荧光定量PCR方法检测MDR1、MRP1和Bcrp1基因mRNA在卵圆细胞和肝细胞中的表达水平。结果免疫组织化学染色显示大鼠肝脏组织中MDR1表达位于门静脉区附近，呈放射状分布，Bcrp1表达定位在细胞膜上。大鼠肝脏卵圆细胞MDR1、MRP1和Bcrp1基因mRNA的表达水平分别是肝细胞的9倍、1．5倍和13．8倍。结论卵圆细胞表达高水平的ABC转运蛋白，后者参与卵圆细胞免受外源性化学物质损伤的自我保护机制。