M-CSF诱导人骨髓间充质干细胞分化为肝样细胞的分子机制

本研究主要目的是明确M-CSF诱导骨髓间充质干细胞分化为肝样细胞的分子机制,为临床中的肝移植和治疗肝病提供新思路。对取自于本院骨科治疗的患者的股骨骨髓间充质干细胞进行提取、分离、传代培养及鉴定。流式细胞仪检测BMSCs的表面表型。为了诱导BMSCs的肝分化,本研究将BMSCs加入到培养基中。骨髓间充质干细胞诱导21 d后,BMSCs表达了肝细胞特异性标志物a-蛋白(AFP)和细胞角蛋白18(CK18),通过免疫荧光染色证实了分化与为分化的BMSCs表达的差异性。分化的BMSCs还显示了肝细胞的体外功能特征,包括白蛋白产生、尿素分泌和糖原储存。本研究结果表明,BMSCs在M-CSF诱导下可分化为功能性肝细胞样细胞,可作为肝病治疗的细胞来源。     

诱导骨髓间充质干细胞向心肌细胞分化研究进展

骨髓间充质干细胞(one marrow mesenchymal stem cells, BMSCs)是骨髓内的一类非造血干细胞,具有自我更新和多向分化的潜能。心肌细胞本身不能再生,受损伤的心肌细胞无法通过自身的增殖和分化完成修复。BMSCs在体内外不同的诱导条件下可分化为心肌细胞,应用于缺血性心脏病的治疗,是目前心肌再生治疗的理想种子细胞。本文主要从外界干预诱导、缺氧条件影响、基因转染、临床自体移植方面将近年诱导BMSCs向心肌细胞分化的研究进行综述,以期为今后临床应用BMSCs治疗心肌梗死等心脏疾病提供理论依据。     

干细胞对肝脏疾病的治疗现状及前景

一、国内外干细胞研究与应用现状干细胞生物学兴起为包括终末期肝病在内的多种难治性人类疾病治疗带来新的希望。干细胞具有高度的自我更新及多向分化潜能。自我更新特性使得干细胞可以成为一个源源不竭的细胞库,克服了肝细胞增殖能力有限的问题;多向分化潜能赋予干细胞一定的可塑性,分化为具有功能的肝细胞。在体外,将干细胞诱导分化为肝细胞,可以解决生物人工肝种子细胞来源困难的问题。在体内,将干细胞经肝动静脉回输入肝脏,从一定程度上提高终末     

肝干细胞分析研究进展

近年来干细胞研究成为生物医学领域研究的热点。肝干细胞是一种具有双向分化能力和自我更新能力的细胞,参与肝脏生长、发育与再生。肝干细胞分化的过程和机理较为复杂,利用肝干细胞进行细胞移植与生物人工肝治疗各种终末期肝病被认为是最有前途的方法之一。本文综述肝干细胞领域近年来研究进展。     

胚胎干细胞分化为肝细胞的研究进展

目前 ,细胞移植作为终末期肝病的辅助治疗方法 ,移植的细胞必须满足在受体肝脏中存活、增殖并可分化为成熟肝细胞两个重要条件 ,但目前应用的肝细胞来源有限 ,其功能随着培养时间的延长而逐渐下降等问题限制了这一治疗策略的广泛开展。作为具有发育全能性和无限增殖能力的细胞 ,胚胎干细胞向肝细胞的分化研究近年来引起了广泛的关注 ,并取得了较大的进展 ,寻找合适、高效的分化诱导方法是目前研究的热点之一。胚胎干细胞向肝细胞的分化研究既可以为临床细胞替代治疗提供合适的细胞来源 ,也可以在药物评估和肝脏发育分化基础研究方面起到重要的作用。通过概括肝脏和拟胚体分化发育的分子机制 ,对体外胚胎干细胞向肝细胞分化的几种诱导体系作了介绍 ,并对分化肝细胞的应用前景和存在的问题进行了讨论。     

干细胞在肝脏疾病治疗中的临床应用及分子机制

干细胞是指一群具有自我更新和多向分化潜能的细胞,是最有治疗潜力的细胞资源,已成为再生医学领域的研究热点。目前,已有多种干细胞用于肝脏疾病的治疗,能有效改善患者血清指标,减少并发症发生,并提高生活质量。这些干细胞在细胞来源、移植途径及治疗效果等多个方面各有特点,但其治疗肝脏疾病的机制尚不清楚。本文将对目前已用于肝病治疗的各种干细胞的临床应用以及可能的分子机制进展进行阐述。     

获得诱导性肝细胞样细胞的策略研究

原位肝移植是目前治疗终末期肝衰竭等疾病最有效的办法,但供体来源少、手术费用昂贵等问题使得每年能够接受肝移植的病人非常少.肝细胞移植弥补了整个肝脏移植的不足,成为治疗肝病的最佳方案,但实验证明不论是在二维还是三维培养体系下原代肝细胞均无法在体外大量扩增,这极大地限制了其在临床上的广泛应用.多能干细胞以及肝干细胞可以在体外...     

成体干细胞向肝细胞分化

成体干细胞跨越胚层限制分化为其他胚层来源的细胞,对揭示不同胚层细胞间相互分化的生物学意义和机制具有重要学术价值,并可以为临床细胞移植治疗开辟新的途径,从而成为当前研究的热点之一。综述了近年来肝源性卵圆细胞、成肝细胞、骨髓源干细胞和其他成体干细胞跨越分化为肝细胞的研究现状与进展,以及卵圆细胞、成肝细胞等的分离鉴定,表面标志、生物学特征和跨越分化机制,并对成体干细胞在肝脏疾病细胞治疗上的应用前景作了展望。     

动物模型在间充质干细胞治疗慢性肝病临床前研究的应用

慢性肝病进一步发展为肝纤维化并导致肝硬化,此时除了器官移植外没有更为有效的治疗方法。然而器官缺乏的问题迫使人们寻找更为有效的治疗策略。间充质干细胞(mesenchymal stem cells,MSCs)有着免疫调节、分化成肝细胞、促进原位肝细胞再生和抑制肝星状细胞的激活等能力,所以利用MSCs开展细胞移植治疗具有非常广阔的前景。本文通过综述各类人的肝病动物模型和运用这些动物模型开展MSCs细胞移植治疗肝病的临床前研究的进展和意义,将为今后在MSCs开展临床治疗的广泛应用中提供安全性和有效性评价的科学依据。     

间充质干细胞对肝纤维化进展的调控机制

肝纤维化是各种病因引起肝损伤后细胞外基质沉积或瘢痕形成的过程,可持续进展为肝硬化,甚至肝癌等终末期肝脏疾病,严重危害人类健康。间充质干细胞(mesenchymal stem cells, MSCs)是一类具有多向分化潜能的多能干细胞,近年来被广泛应用于多种疾病治疗。现今,MSCs移植已被运用于肝纤维化治疗研究,治疗结局众说纷纭,其作用机制莫衷一是。现就MSCs通过免疫、炎症、归巢等途径对肝纤维化进展的调控机制做一综述。     

Human bone marrow mesenchymal stem cells are resistant to HBV infection during differentiation into hepatocytes in vivo and in vitro

Hepatocyte-like cells induced from bone marrow mesenchymal stem cells (BMSCs) recover liver function in animal models with liver failure. Our initial findings revealed that human BMSCs improved liver function in hepatitis B patients with end stage liver disease. However, the susceptibility of BMSCs to HBV infection during induction toward hepatocytes remains unknown. We have assessed whether BMSCs-derived hepatocyte-like cells can function like liver cells and be infected by HBV. A new and efficient way to direct the differentiation of BMSCs into functional hepatocytes was developed. BMSCs obtained from hepatitis B patients were induced to differentiate into hepatocytes through exposure to HGF, FGF-4, and EGF. After 6 days of exposure, BMSCs-derived hepatocyte-like cells that expressed a subset of hepatic genes and showed hepatic functions were obtained. HBV was used to infect the differentiated cells, and subsequently these cells were assayed for the presence of HBeAg, HBsAg, and HBV DNA. BMSCs proved resistant to HBV infection, both in vitro and during differentiation into hepatocytes in vitro. This demonstrates that BMSCs are resistant to HBV infection. BMSCs are viable for transplantation and should facilitate further research exploring the in vivo HBV-resistance of the hepatocytes derived from BMSCs after transplantation, a characteristic that could form the basis for hepatocyte transplantation.     

The therapeutic potential of bone marrow-derived mesenchymal stem cells on hepatic cirrhosis

Hepatic cirrhosis is the end-stage of chronic liver diseases. The majority of patients with hepatic cirrhosis die from life-threatening complications occurring at their earlier ages. Liver transplantation has been the most effective treatment for these patients. Since liver transplantation is critically limited by the shortage of available donor livers, searching for an effective alternative therapy has attracted great interest in preclinical studies. The transplantation of autologous bone marrow-derived mesenchymal stem cells holds great potential for treating hepatic cirrhosis. Mesenchymal stem cells can differentiate to hepatocytes, stimulate the regeneration of endogenous parenchymal cells, and enhance fibrous matrix degradation. Experimental and clinical studies have shown promising beneficial effects. This review is intended to translate the bench study results to the patients' bedside. The potential interventions of mesenchymal stem cells on cirrhosis are illustrated in terms of the cellular and molecular mechanisms of hepatic fibrogenesis.     

Ameliorative Effect of Bone Marrow-Derived Stem Cells on Injured Liver of Mice Infected with Schistosoma mansoni

The technique of stem cells or hepatocytes transplantation has recently improved in order to bridge the time before whole-organ liver transplantation. In the present study, unfractionated bone marrow stem cells (BMSCs) were harvested from the tibial and femoral marrow compartments of male mice, which were cultured in Dulbecco''s modified Eagle''s medium (DMEM) with and without hepatocyte growth factor (HGF), and then transplanted into Schistosoma mansoni-infected female mice on their 8th week post-infection. Mice were sacrificed monthly until the third month of bone marrow transplantation, serum was collected, and albumin concentration, ALT, AST, and alkaline phosphatase (ALP) activities were assayed. On the other hand, immunohistopathological and immunohistochemical changes of granuloma size and number, collagen content, and cells expressing OV-6 were detected for identification of liver fibrosis. BMSCs were shown to differentiate into hepatocyte-like cells. Serum ALT, AST, and ALP were markedly reduced in the group of mice treated with BMSCs than in the untreated control group. Also, granuloma showed a marked decrease in size and number as compared to the BMSCs untreated group. Collagen content showed marked decrease after the third month of treatment with BMSCs. On the other hand, the expression of OV-6 increased detecting the presence of newly formed hepatocytes after BMSCs treatment. BMSCs with or without HGF infusion significantly enhanced hepatic regeneration in S. mansoni-induced fibrotic liver model and have pathologic and immunohistopathologic therapeutic effects. Also, this new therapeutic trend could generate new hepatocytes to improve the overall liver functions.     

Generation,characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells

Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end‐stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end‐stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra‐hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra‐hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. J. Cell. Physiol. 228: 298–305, 2013. © 2012 Wiley Periodicals, Inc.     

Hepatic progenitor cells

Liver diseases are associated with a marked reduction in the viable mass of hepatocytes. The most severe cases of liver disease (liver failure) are treated by orthotopic liver transplantation. One alternative to whole organ transplantation for patients with hepatic failure (and hereditary liver disease) is hepatocyte transplantation. However, there is a serious limitation to the treatment of liver diseases either by whole organ or hepatocyte transplantation, and that is the shortage of organ donors. Therefore, to overcome the problem of organ shortage, additional sources of hepatocytes must be found. Alternative sources of cells for transplantation have been proposed including embryonic stem cells, immortalised liver cells and differentiated cells. One other source of cells for transplantation found in the adult liver is the progeny of stem cells. These cells are termed hepatic progenitor cells (HPCs). The therapeutic potential of HPCs lies in their ability to proliferate and differentiate into hepatocytes and cholangiocytes. However, using HPCs as a cell therapy cannot be exploited fully until the mechanisms governing hepatocyte differentiation are elucidated. Here, we discuss the fundamental cellular and molecular elements required for HPC differentiation to hepatocytes.     

Hepatic differentiation of adult and fetal liver stromal cells in vitro

The liver has a marked capacity for regeneration. In most cases the liver regeneration is determined by hepatocytes. The regenerative capacity of hepatocytes is significantly reduced in acute or chronic damage. For example, in patients with alcoholic cirrhosis repair mechanisms are not activated and only organ transplantation or advanced methods of regenerative medicine can help such patients. Clinical trials including patients with various forms of liver disease have shown promising results of transplantation of autologous bone marrow stem cells. However, improvement of the effectiveness of such treatment requires optimization of sources of progenitor cells. In this study we have isolated stromal cells from the liver biopsies of three patients with alcoholic cirrhosis, performed their morphological and phenotypic analysis, and evaluated the hepatic potential of these cells in vitro. Stromal cells isolated from the fetal liver were used for comparative evaluation. During hepatic differentiation both types of cells expressed hepatic markers and secreted albumin. These results can serve as a basis for the development of a new method for the treatment of end-stage liver disease. The stromal cells isolated from the liver biopsies proliferate for a long time in a culture and this provides opportunity to produce them in large amounts for subsequent differentiation into hepatocyte-like cells and autologous transplantation.     

自体骨髓干细胞移植治疗失代偿期肝硬化的临床效果分析

目的:观察自体骨髓间充质干细胞(BMSC)移植治疗合并不同并发症的失代偿期肝硬化的临床效果。方法:回顾性分析我院自2008年12月至2013年12月收治的148例经自体BMSC移植治疗的肝硬化合并肝性脑病、肝肾综合征、肝源性糖尿病以及消化道出血患者治疗前后的肝、肾功能、血清蛋白、血常规等指标的变化情况。结果:治疗后,肝硬化合并肝性脑病患者的ALT、血氨水平改善明显,TBIL反复;合并肝肾综合征的患者HB、Crea水平改善明显,ALT、AST、DBIL反复;合并肝源性糖尿病患者的ALT、TBIL、DBIL、TB、ALB、血糖水平改善明显;合并消化道出血患者的ALT、TP、ALB改善明显,AST、TBIL、PLT反复。结论:自体BMSC移植治疗肝硬化合并肝源性糖尿病的效果较好,对合并肝性脑病、肝肾综合征以及消化道出血患者的效果欠佳。