Prospective isolation of a bipotential clonogenic liver progenitor cell in adult mice

The molecular identification of adult hepatic stem/progenitor cells has been hampered by the lack of truly specific markers. To isolate putative adult liver progenitor cells, we used cell surface-marking antibodies, including MIC1-1C3, to isolate subpopulations of liver cells from normal adult mice or those undergoing an oval cell response and tested their capacity to form bilineage colonies in vitro. Robust clonogenic activity was found to be restricted to a subset of biliary duct cells antigenically defined as CD45(-)/CD11b(-)/CD31(-)/MIC1-1C3(+)/CD133(+)/CD26(-), at a frequency of one of 34 or one of 25 in normal or oval cell injury livers, respectively. Gene expression analyses revealed that Sox9 was expressed exclusively in this subpopulation of normal liver cells and was highly enriched relative to other cell fractions in injured livers. In vivo lineage tracing using Sox9creER(T2)-R26R(YFP) mice revealed that the cells that proliferate during progenitor-driven liver regeneration are progeny of Sox9-expressing precursors. A comprehensive array-based comparison of gene expression in progenitor-enriched and progenitor-depleted cells from both normal and DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine or diethyl1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate)-treated livers revealed new potential regulators of liver progenitors.     

HIV-1 Nef protein expression in human CD34+ progenitors impairs the differentiation of an early T/NK cell precursor

HIV-1 impairs the production of T cells, through mechanisms that are still unknown. Here, we investigated the effect of the expression of HIV-1 Nef on the T-cell potential of human hematopoietic CD34(+) precursors. Those progenitors were transduced by using lentiviral vectors expressing Nef and cultured on OP9-DL1 cells allowing the differentiation of T cell from human hematopoietic precursors. We demonstrate that Nef impairs the generation of a CD3epsilon(+)CD5(+) CD1a(+) precursor stage that has initiated a D-J rearrangement of the TCRbeta locus. Onward stages of T-cell development were also affected with a quantitative reduction of CD4(+) intraCD3epsilon(+) Immature single positive cells (ISP), Double Positive (DP) CD4(+)CD8(+) TCRalphabeta T cells and CD56(+) NK cells. But B cell production was not affected. Limiting dilution analyses demonstrated a significant reduction in the frequency of T/NK progenitors among Nef-expressing CD34(+) cells. Altogether, these data demonstrate that Nef interferes with the differentiation of a primitive lymphoid human precursor with a T/NK potential.     

SOX6和SOX9基因转染对人原发性骨关节炎关节软骨间充质祖细胞增殖和成软骨分化的调控作用

目的观察SOX6和SOX9基因转染对原发性OA关节软骨MPCs的促增殖、分化作用,为通过调控关节软骨MPCs以防治原发性OA提供理论依据。方法分别以pAdTrack-CMV-SOX6、SOX9腺病毒穿梭质粒构建SOX6、SOX9基因,并感染原发性OA关节软骨MPCs,比较基因感染组和未感染组成软骨诱导分化后TB、Ⅱ型胶原以及Ⅱ型胶原mRNA表达的变化。结果SOX6和SOX9能够分别稳定感染OA关节软骨MPCs;经二者分别感染的关节软骨MPCs成软骨诱导分化后,其TB染色、Ⅱ型胶原染色呈强阳性表达,未基因感染细胞为弱阳性着色;SOX6基因感染原发性OA关节软骨MPCs的Ⅱ型胶原mRNA表达量为未基因感染细胞的3.8倍(P0.01),SOX9基因为未感染细胞的5.15倍(P0.01)。结论构建的SOX6、SOX9基因序列与基因库报道序列完全一致;SOX6和SOX9能稳定感染原发性OA关节软骨MPCs,并显著促进感染细胞成软骨分化;提示通过适宜浓度的bFGF、TGF-β1对原发性OA关节软骨MPCs的作用及SOX6和SOX9基因感染,可能具有促进原发性OA关节软骨损伤修复的作用。     

TLR agonists induce the differentiation of human bone marrow CD34+ progenitors into CD11c+ CD80/86+ DC capable of inducing a Th1-type response

We recently reported that human bone marrow hematopoietic CD34(+) progenitors express functional Toll-like receptors (TLR) and can differentiate into myeloid cells just by stimulation with resiquimod (R848), a specific agonist for TLR7/8. However, the mechanisms by which R848 induces cell differentiation, the effects of other TLR agonists and the functionality of the differentiated cells are not known. Comparable to R848, loxoribine (a TLR7 agonist) and Pam(3)CSK(4) (a TLR2 agonist) induced cytokine production and cell differentiation along the myeloid lineage. R848 and loxoribine were more effective than Pam(3)CSK(4) at inducing the lineage-negative (CD11c(+) CD14(-)) dendritic cells (DC), whereas Pam(3)CSK(4) was more effective at inducing CD11c(+) CD14(+) monocytes. Both cell subsets expressed CD80/CD86 and HLA-DR molecules; however, they showed differential expression of CD1a, CD1b, CD1c, CD11b, CD206 and CD207 markers when compared with each other. Cell differentiation into DC was significantly inhibited by an anti-TNF-alpha nonoclonal antibody. The CD11c(+) CD14(-) subset was isolated and shown to be more potent in stimulating an alloreaction than the CD11c(+) CD14(+) subset. Collectively, these data highlight the differential effects of TLR agonists on human bone marow CD34(+) progenitor cells and provide a new opportunity for generating functional DC that would be useful in cancer vaccination.     

干细胞扩增及肝向分化过程中相关指标及其检测方法

文题释义：干细胞肝向分化：是指来自于胚胎、胎儿或成体内具有在一定条件下无限制自我更新与增殖分化能力的一类细胞,通过形态、功能的特殊变化,建立起肝细胞特征的过程。这一过程与细胞分裂共同发生,并伴随干细胞多能性的减弱与肝功能表达的增强。 生物人工肝：是以培养肝(样)细胞为基础的生物或混合生物人工肝支持系统。它的基本要素包括高活性和功能的肝(样)细胞、适合的生物反应器与外部控制系统、有效的体外循环系统,可通过暂时或部分替代肝脏功能,实现对肝脏功能不全或相关疾病的治疗。  摘要背景：干细胞在组织工程学、再生医学、细胞治疗以及药物研究方面具有巨大的应用前景。近年来,以生物人工肝为例的应用研究需要大规模扩增出高质量的干细胞并最终定向分化为肝(样)细胞。如何通过此途径高效获得一致性、功能性完好并且标志物均匀表达的分化细胞,是需要解决的关键问题。目的：对干细胞扩增及肝向分化过程相关检测指标与检测方法进行综述,总结已应用于在线检测的指标与方法,讨论部分指标与方法应用于在线检测的局限性,并对未来有望应用于在线检测的指标和检测技术进行展望。 方法：由第一作者检索1990至2019年PubMed数据库、Web of Science核心合集、Elsevier数据库、中国知网等收录的与干细胞扩增及肝向分化过程相关的文献。英文检索词为“stem cells,expansion,hepatic differentiation,monitoring,real-time online”,中文检索词为“干细胞,扩增,肝向分化,监测,实时在线”,共计检索93篇文章,最终筛选了符合标准的53篇进行综述。结果与结论：干细胞扩增及肝向分化过程的相关检测指标与检测方法众多,其中扩增过程的检测指标主要涉及干细胞多能性的保持、代谢活性、存活率以及转癌趋势。肝向分化过程因细胞种类而异,其中多能干细胞和中胚层谱系成体多能干细胞要先向内胚层定向分化,再分化为成熟肝(样)细胞,而以肝干/祖细胞为主的内胚层谱系成体多能干细胞可直接分化为成熟肝(样)细胞。分化过程不同阶段细胞的特异性标志物、存活率以及代谢活性是检测的重点。目前,基于大型生化检测分析设备的检测方法虽然可靠性高,但面临实时性差、成本高、难以集成小型化等问题。未来,干细胞扩增及肝向分化过程中关键检测指标的筛选、检测标准的量化以及自动化在线检测的实现,需要重点研究。ORCID: 0000-0002-3881-5577(吴昌哲);0000-0002-6052-8400(杨嘉屹)中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Regulation of dendritic cell differentiation and function by Notch and Wnt pathways

Summary: The process of dendritic cell differentiation is governed by a tightly controlled signaling network regulated by cytokines and direct interaction between progenitor cells and bone marrow stroma. Notch signaling represents one of the major pathways activated during direct interaction between hematopoietic progenitor cells and bone marrow stroma. Wnt pathway is activated by soluble proteins produced by bone marrow stroma. Until recently, the role of Notch and Wnt signaling in the development of myeloid cells and dendritic cells in particular remained unclear. In this review, we discuss recent exciting findings that shed light on the critical role of Notch and Wnt pathways, their interaction in differentiation and function of dendritic cells, and their impact on immune responses.     

Relationship between hepatic progenitor cells and stellate cells in chronic hepatitis C genotype 4

Hepatitis C virus (HCV) infection represents a major health problem in many areas of the world, especially Egypt. Hepatic progenitor cells (HPCs) and hepatic stellate cells (HSCs) have been implicated in fibrosis progression in chronic HCV. The aim of this study was to investigate the role of HPCs and HSCs in chronic HCV infection and the relationship between both cell types. This retrospective study was conducted on 100 chronic HCV patients. Immunohistochemistry was performed on liver tissue sections for cytokeratin 19 (progenitor cell markers), smooth muscle actin (stellate cell markers), matrix metalloproteinase‐9 (MMP‐9), and transforming growth factor beta (TGF‐ß). The necroinflammatory activity was significantly related to the number of isolated HPCs and TGF‐ß expression (p = 0.003 and p = 0.001 respectively). Advanced stages of fibrosis showed significantly increase number of HPCs (p = 0.001), higher ratio of HSCs (p = 0.004), more expression of TGF‐ß (p = 0.001) and MMP‐9 (p = 0.001). There was a significant direct correlation between immunoexpression of HPCs and HSCs for isolated cells (r = 0.569, p = 0.001) and ductular reaction (r = 0.519, p = 0.001). Hepatic progenitor cells and stellate cells play a significant role in the development and progression of fibrosis in chronic HCV. More interestingly, the significant direct correlation between HPCs and HSCs suggests a synergistic interrelation.     

Anatomical and histological characteristics of the hepatobiliary system in adult Sox17 heterozygote mice

Biliary atresia (BA) is a rare neonatal disease characterized by inflammation and obstruction of the extrahepatic bile ducts (EHBDs). The Sox17-haploinsufficient (Sox17^+/−) mouse is an animal model of BA that encompasses bile duct injury and subsequent BA-like inflammation by the neonatal stage. Most Sox17^+/− neonates die soon after birth, but some Sox17^+/− pups reach adulthood and have a normal life span, unlike human BA. However, the phenotype and BA-derived scars in the hepatobiliary organs of surviving Sox17^+/− mice are unknown. Here, we examined the phenotypes of the hepatobiliary organs in post-weaning and young adult Sox17^+/− mice. The results confirmed the significant reduction in liver weight, together with peripheral calcinosis and aberrant vasculature in the hepatic lobule, in surviving Sox17^+/− mice as compared with their wild-type (WT) littermates. Such hepatic phenotypes may be sequelae of hepatobiliary damage at the fetal and neonatal stages, a notion supported by the slight, but significant, increases in the levels of serum markers of liver damage in adult Sox17^+/− mice. The surviving Sox17^+/− mice had a shorter gallbladder in which ectopic hepatic ducts were more frequent compared to WT mice. Also, the surviving Sox17^+/− mice showed neither obstruction of the EHBDs nor atrophy or inflammation of hepatocytes or the intrahepatic ducts. These data suggest that some Sox17^+/− pups with BA naturally escape lethality and recover from fetal hepatobiliary damages during the perinatal period, highlighting the usefulness of the in vivo model in understanding the hepatobiliary healing processes after surgical restoration of bile flow in human BA.     

犬骨髓内皮祖细胞生物学特性及诱导分化

目的:探讨犬骨髓内皮祖细胞(EPCs)随培养时间延长其生物学特性变化及向内皮细胞(ECs)分化能力。方法:免疫微珠分选方法纯化犬骨髓CD14 细胞,EGM-MV2条件培养基培养,于不同时间检测EPCs的生物学特性;将存活至8周的EPCs以分化培养基(M199 20%胎牛血清 VEGF)诱导培养,检测ECs表面标志的表达。结果:早期EPCs为分选后8代之前的EPC,体积略小,类圆形,60%融合时呈串珠样排列,表达CD133、CD14;晚期EPCs由表达VE-cadherin、KDR、CD14的早期EPCs分化而来,形态为多边形,分泌活动明显加强,表达CD133、VE-cadherin、CD14和KDR;诱导分化细胞呈鹅卵石样外观,表达Ⅷ因子、CD31。结论:犬骨髓EPCs随培养时间呈现不同生物学特性,早期EPCs不稳定,晚期EPCs显示出更稳定的生物学特性,能够分化为ECs,是血管组织工程学研究良好的种子细胞。