人骨髓间充质干细胞移植在大鼠肝再生衰竭中的作用

骨髓间充质干细胞（MSCs）具有可塑性,包括可以向肝细胞分化的能力。目前诱导MSCs向肝细胞分化的体内外相关实验研究已经由动物向人MSCs过渡。基于人MSCs的人体内实验则较为少见,具体机制尚不明了。因此本实验将人MSCs移植入大鼠肝衰竭模型,对其体内变化机制进行观察。     

间充质干细胞向内皮细胞分化的研究进展

间充质干细胞（MSCs）是一种起源于中胚层的成体干细胞,主要存在于骨髓中;近年来,脐血、外周血、脂肪、皮肤等多种组织中亦相继分离出MSCs[1]。研究证实,MSCs在体内及体外均可诱导分化为其他组织细胞,如内皮细胞（VEC）、脂肪细胞、成骨细胞、神经细胞等,即具有可塑性。现将MSCs诱导分化为VEC的相关研究及临床应用作一综述。     

骨髓间充质干细胞分化为心肌细胞的研究进展

骨髓间充质干细胞（MSCs）在不同的诱导条件下可向心肌细胞（CM）分化,但目前对于MSCs心肌化过程中的信号分子、具体途径及基因调控等均不太明确。本文对MSCs向心肌细胞分化的实验条件及目前研究可能包含的分子机制作一综述。     

脂肪基质干细胞评价肝癌药敏谱的实验研究

肿瘤干细胞是肿瘤发生、扩散与转移的基础，根治肿瘤就要根除肿瘤干细胞。我们以往研究发现，肝癌是一种干细胞病，间充质干细胞（MSCs）可以间接反映肝癌干细胞药物敏感情况，有希望利用MSCs发展针对肝癌干细胞的药敏试验。脂肪基质干细胞（ASCs）与MSCs特性相似，取材更加简便，近来引起越来越多的重视。ASCs是否与MSCs一样可以反映肝癌干细胞药物敏感隋况，是我们感兴趣的问题。我们分离肝癌大鼠肝癌细胞、ASCs与MSCs，了解ASCs与MSCs反映肝癌干细胞药敏隋况差异，报道如下。     

左卡尼汀提高大鼠心肌梗死后移植骨髓间充质干细胞的存活和作用

目的探讨左卡尼汀（LC）是否能提高心肌梗死后移植骨髓间充质干细胞（MSCs）的存活率,从而提高其疗效。方法60只大鼠随机分为5组：假手术组、模型组、LC组、MSCs组和左卡尼汀联合骨髓间充质干细胞（LC＋MSCs）组。4周后检测心功能、MSCs存活情况和梗死区心肌纤维化水平。结果4周后,与MSCs组比较,LC＋MSCs组MSCs的存活、左室心功能、心肌纤维化均改善（P〈0．05）。结论LC联合MSCs使用可提高MSCs的存活率,更好地改善心肌梗死后的心功能和心肌纤维化。     

间充质干细胞治疗心血管疾病的研究进展

<正>间充质干细胞(mesenchymal stem cells,MSCs)是干细胞家族的重要成员,具有多向分化、造血支持、免疫调控等特点。近期大量研究关注MSCs的归巢能力、旁分泌机制及抗炎作用,其在心血管疾病治疗中作用的报道也较多,可以改善心脏功能、提高预后。本文结合近期相关研究,对其机制和问题做一综述。     

MicroRNAs与骨质疏松症研究

MicroRNAs（miRNAs or miRs）为一种新的基因调控机制,MicroRNAs是由22个核苷酸组成的内源性非编码小分子RNA,调节蛋白翻译和mRNA的稳定。间充质干细胞（mesenchymal stem cells,MSCs）分化异常与骨质疏松症的发生有着密切关系。最近研究发现miRNAs在MSCs分化过程中发挥着重要的调控作用,但具体调控机制尚未完全阐明。进一步深入研究miRNAs在MSCs中的作用,全面了解MSCs分化的机制,对骨质疏松症的预防和治疗有重要意义。     

间充质干细胞与糖尿病慢性并发症

间充质干细胞（MSCs）具有多向分化能力，由于MSCs的分化细胞类型与糖尿病慢性并发症损伤的细胞类型吻合，近年来越来越多的研究针对MSCs在糖尿病慢眭并发症发病机制中的作用。糖尿病时高血糖可能通过影响MSCs的细胞分化类型而导致糖尿病多种并发症的发生。从MSCs多向分化潜能的角度解释糖尿病慢性并发症的发病机制为其治疗提供了新的思路，具有重要的临床意义。     

心肌梗死后骨髓间充质干细胞移植对心室肌细胞复极活动的影响

目的调查心肌梗死后植入骨髓间充质干细胞（mesenchymal stem cells，MSCs）对心室肌细胞复极活动的影响。方法10只健康幼猪作为正常对照组，23只幼猪通过球囊导管堵闭左冠状动脉前降支法建立心肌梗死模型并分别移植MSCs悬液（干细胞组，n=13）或等量生理盐水（梗死组，n=10），6周后行心肌组织免疫组化双染色、左心室血流动力学及左心室肌细胞复极活动的检查。结果（1）心肌组织免疫组化双染色示，MSCs源性细胞集中分布于梗死区，胞浆中出现了肌钙蛋白T（troponinT）；（2）干细胞组左心室射血分数、左心室收缩压和舒张末压虽未恢复正常（与对照组相比，P均〈0．01），但较梗死组均改善（P均〈0．05）；（3）梗死组和干细胞组动作电位复极90％的时间（APD90）、复极时间（RT）、APD和RT离散度值较对照组均延长（P均〈0．01），但干细胞组较梗死组显著缩短（P〈0．05—0．01）；（4）对照组APD重建曲线斜率〈1（正常），而干细胞组和梗死组APD重建曲线斜率均〉1（异常），但前者斜率明显小于后者；（5）干细胞组诱发APD交替的阈值周长虽高于对照组（P〈0．01），却低于梗死组（P〈0．05）。结论MSCs移植可减轻梗死心室复极紊乱，其机制可能与MSCs参与心肌组织修复、改善血流动力学水平有关。     

骨髓间质干细胞对系统性红斑狼疮患者调节性T细胞的免疫调节作用

目的探讨自体与异体骨髓间质干细胞（MSCs）对系统性红斑狼疮（SLE）患者调节性T细胞的免疫调节作用。方法用Percoll密度梯度离心法从14例SLE患者和15例健康人骨髓中分离MSCs,同时用免疫磁珠（MACS）分离SLE患者外周血CD4^＋CD25^＋T细胞。将SLE患者外周血分离的淋巴细胞或CD4^＋CD25^＋T细胞与自体、异体MSCs共培养,观察MSCs对淋巴细胞及CD4^＋CD未T细胞增殖的影响,同时测CD4^＋CD25^＋T细胞分泌IL-10、转化生长因子（TGFβ）水平及细胞毒T淋巴细胞相关抗原4（CTLA-4）表达。结果自体与异体MSCs均抑制淋巴细胞增殖,其抑制率分别为56．32％、65．46％。MSCs以数量依赖性方式促进纯化CD4^＋CD25^＋T细胞增殖,分泌IL-10、TGFβ水平升高。结论MSCs可纠正SLE活动时CD4＋CD25^＋T细胞免疫缺陷,并抑制淋巴细胞过度活化,可能在自身免疫病的外周血造血干细胞和间质干细胞共移植或MSCs单独移植中发挥重要的免疫调节作用。     

结肠炎大鼠炎症黏膜提取液对骨髓间质干细胞增殖和表面分化抗原的影响

背景:动物实验和临床试验均表明间质干细胞(MSCs)对受损肠道组织有一定修复作用,然而目前尚不清楚肠道炎症微环境对MSCs移植治疗炎症性肠病(IBD)有何影响。目的:通过体外实验观察结肠炎大鼠模型肠道炎症黏膜提取液对骨髓MSCs增殖和表面分化抗原的影响。方法:以全骨髓贴壁法分离和原代培养大鼠MSCs并行传代扩增。取三硝基苯磺酸(TNBS)结肠炎大鼠模型肠道炎症黏膜提取液(0、1、2、3 ml)与MSCs共培养,倒置相差显微镜观察各组细胞贴壁和生长情况,绝对计数法绘制细胞生长曲线,流式细胞术检测细胞表面分化抗原表达。结果:全骨髓贴壁法可成功分离MSCs,所获细胞CD29、CD44表达阳性,CD105表达低度阳性,CD34、CD45表达阴性。3 ml炎症黏膜提取液处理组MSCs接种6 h后见细胞贴壁,36 h开始克隆性增生,此后细胞增殖速度较空白对照组明显加快,第6 d即达100%融合,但表面分化抗原表达与空白对照组相比无明显变化。结论:结肠炎大鼠炎症黏膜提取液可促进骨髓MSCs增殖,但对细胞表面分化抗原无明显影响。     

Role of bone marrow-derived mesenchymal stem cells in a rat model of severe acute pancreatitis

AIM: To investigate the role and potential mechanisms of bone marrow mesenchymal stem cells (MSCs) in severe acute peritonitis (SAP).METHODS: Pancreatic acinar cells from Sprague Dawley rats were randomly divided into three groups: non-sodium deoxycholate (SDOC) group (non-SODC group), SDOC group, and a MSCs intervention group (i.e., a co-culture system of MSCs and pancreatic acinar cells + SDOC). The cell survival rate, the concentration of malonaldehyde (MDA), the density of superoxide dismutase (SOD), serum amylase (AMS) secretion rate and lactate dehydrogenase (LDH) leakage rate were detected at various time points. In a separate study, Sprague Dawley rats were randomly divided into either an SAP group or an SAP + MSCs group. Serum AMS, MDA and SOD, interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α levels, intestinal mucosa injury scores and proliferating cells of small intestinal mucosa were measured at various time points after injecting either MSCs or saline into rats. In both studies, the protective effect of MSCs was evaluated.RESULTS: In vitro, The cell survival rate of pancreatic acinar cells and the density of SOD were significantly reduced, and the concentration of MDA, AMS secretion rate and LDH leakage rate were significantly increased in the SDOC group compared with the MSCs intervention group and the Non-SDOC group at each time point. In vivo, Serum AMS, IL-6, TNF-α and MAD level in the SAP + MSCs group were lower than the SAP group; however serum IL-10 level was higher than the SAP group. Serum SOD level was higher than the SAP group at each time point, whereas a significant between-group difference in SOD level was only noted after 24 h. Intestinal mucosa injury scores was significantly reduced and the proliferating cells of small intestinal mucosa became obvious after injecting MSCs.CONCLUSION: MSCs can effectively relieve injury to pancreatic acinar cells and small intestinal epithelium, promote the proliferation of enteric epithelium and repair of the mucosa, attenuate systemic inflammation in rats with SAP.     

Bone-marrow mesenchymal stem cells reduce rat intestinal ischemia-reperfusion injury,ZO-1 downregulation and tight junction disruption via a TNF-α-regulated mechanism

AIM: To investigate the effect of bone-marrow mesenchymal stem cells (BM MSCs) on the intestinal mucosa barrier in ischemia/reperfusion (I/R) injury. METHODS: BM MSCs were isolated from male Sprague-Dawley rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. I/R injury was induced by occlusion of the superior mesenteric artery for 30 min. Rats were treated with saline, BM MSCs (via intramucosal injection) or tumor necrosis factor (TNF)-α blocking antibodies (via the tail vein). I/R injury was assessed using transmission electron microscopy, hematoxylin and eosin (HE) staining, immunohistochemistry, western blotting and enzyme linked immunosorbent assay.RESULTS: Intestinal permeability increased, tight junctions (TJs) were disrupted, and zona occludens 1 (ZO-1) was downregulated after I/R injury. BM MSCs reduced intestinal mucosal barrier destruction, ZO-1 downregulation, and TJ disruption. The morphological abnormalities after intestinal I/R injury positively correlated with serum TNF-α levels. Administration of anti-TNF-α IgG or anti-TNF-α receptor 1 antibodies attenuated the intestinal ultrastructural changes, ZO-1 downregulation, and TJ disruption. CONCLUSION: Altered serum TNF-α levels play an important role in the ability of BM MSCs to protect against intestinal I/R injury.     

Hematopoietic stem cell origin of mesenchymal cells: opportunity for novel therapeutic approaches

There has been a general belief that there are two types of adult stem cells, i.e., hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), each with distinctly different functions. According to this dogma, HSCs produce blood cells, while MSCs are thought to generate a number of non-hematopoietic cells including fibroblasts, adipocytes, chondrocytes and bone cells. Recently, a number of studies, including those in our laboratory based on single HSC transplantation, blurred the clear distinction between HSCs and MSCs and strongly suggested an HSC origin of the adult mesenchymal tissues. This review summarizes the experimental evidence for this new paradigm and the literature pointing out the vagary in the stem cell nature of MSCs. The concept of the HSC origin of mesenchymal cells will have many immediate and long-term impacts on the therapies of diseases and injuries of the connective tissues.     

自体骨髓间充质干细胞联合造血干细胞共移植治疗恶性血液病五例疗效观察

目的 研究自体骨髓间充质干细胞(MSCs)与造血干细胞共移植治疗恶性血液病的安全性和可行性,及其对移植后造血重建的影响.方法 从无骨髓浸润的恶性血液病患者本人骨髓中分离、培养间充质干细胞,经放化疗等预处理后,与造血干细胞共移植治疗恶性血液病患者5例,其中恶性淋巴瘤4例,粒细胞肉瘤1例,并观察其对移植后造血重建的影响.结果 MSCs联合造血干细胞共移植治疗恶性血液病患者5例,MSCs输注过程顺利,未见明显不良反应.移植后造血恢复过程中,中性粒细胞≥0.5×109/L的中位时间为9.4(8～11)d、血小板≥20×109/L的中位时间为12.2(10～14)d.结论 MSCs联合造血干细胞共移植治疗恶性血液病安全性好,未见明显副作用.结果 提示输注MSCs可促进造血恢复,但其远期疗效仍有待于进一步观察.     

Mesenchymal stem cells and their potential as cardiac therapeutics

Mesenchymal stem cells (MSCs) represent a stem cell population present in adult tissues that can be isolated, expanded in culture, and characterized in vitro and in vivo. MSCs differentiate readily into chondrocytes, adipocytes, osteocytes, and they can support hematopoietic stem cells or embryonic stem cells in culture. Evidence suggests MSCs can also express phenotypic characteristics of endothelial, neural, smooth muscle, skeletal myoblasts, and cardiac myocyte cells. When introduced into the infarcted heart, MSCs prevent deleterious remodeling and improve recovery, although further understanding of MSC differentiation in the cardiac scar tissue is still needed. MSCs have been injected directly into the infarct, or they have been administered intravenously and seen to home to the site of injury. Examination of the interaction of allogeneic MSCs with cells of the immune system indicates little rejection by T cells. Persistence of allogeneic MSCs in vivo suggests their potential "off the shelf" therapeutic use for multiple recipients. Clinical use of cultured human MSCs (hMSCs) has begun for cancer patients, and recipients have received autologous or allogeneic MSCs. Research continues to support the desirable traits of MSCs for development of cellular therapeutics for many tissues, including the cardiovascular system. In summary, hMSCs isolated from adult bone marrow provide an excellent model for development of stem cell therapeutics, and their potential use in the cardiovascular system is currently under investigation in the laboratory and clinical settings.     

骨髓间质干细胞在缺血性心脏病中的应用

骨髓间质干细胞(MSCs)是一种多能造血于细胞,在一定诱导条件下,可分化为多种造血外组织细胞,如骨细胞、软骨细胞、 心肌细胞等,因此,在组织工程方面具有广泛的应用前景。近年来,MSCs在缺血性心脏病中的应用价值已得到证实和肯定,从而为 缺血性心脏病的治疗带来了新的契机。本文就骨髓间质干细胞在缺血性心脏病中的应用进行了回顾和展望。     

The surface adhesion molecule CXCR4 stimulates mesenchymal stem cell migration to stromal cell-derived factor-1 in vitro but does not decrease apoptosis under serum deprivation.

BACKGROUND: Bone marrow mesenchymal stem cells (MSCs) can be used for myocardial repair following myocardial infarction. Increased expression of stromal cell-derived factor-1 (SDF-1) by an ischemic myocardium attracts CXCR4+ stem cells toward it. CXCR4, the receptor for SDF-1, is important in the migration, homing, and survival of hematopoietic stem cells. Although low levels of CXCR4 expression were found in minor subpopulations of cultured MSCs, most MSCs do not express CXCR4. To optimize the migration and survival of human MSCs, we expressed the CXCR4 gene in these cells using retroviral transduction. MATERIALS AND METHODS: We isolated and cultured MSCs from healthy volunteers and transduced them with a retroviral vector containing either CXCR4 and green fluorescent protein (GFP; CXCR4/GFP vector) or GFP alone (control vector). Flow cytometry confirmed successful transduction and GFP and CXCR4 expression. We used a transwell migration system to study MSC migration to SDF-1. We used Annexin V and propidium iodide stains to assess cell survival before and after the survival challenge. RESULTS: Flow cytometry showed that, on average, 83.4+/-17.7% of transduced MSCs expressed CXCR4. Compared with control MSCs, MSCs transduced with CXCR4 showed significantly more migration toward SDF-1, threefold greater at 3 h and more than fivefold greater at 6 h. Mesenchymal stem cells transduced with CXCR4 showed no significant difference in survival under normal to serum-deprived growth conditions. CONCLUSION: Mesenchymal stem cells can be efficiently transduced to express CXCR4, and transduced MSCs migrate rapidly toward SDF-1. CXCR4 expression does not render survival advantage to MSCs under serum-deprived conditions.     

Hepatic differentiation capability of rat bone marrow-derived mesenchymal stem cells and hematopoietic stem cells

AIM: To investigate the different effects of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) on hepatic differentiation. METHODS: MSCs from rat bone marrow were isolated and cultured by standard methods. HSCs from rat bone marrow were isolated and purified by magnetic activated cell sorting. Both cell subsets were induced. Morphology, RT-PCR and immunocytochemistry were used to identify the hepatic differentiation grade. RESULTS: MSCs exhibited round in shape after differentiation, instead of fibroblast-like morphology before differentiation. Albumin mRNA and protein were expressed positively in MSCs, without detection of alpha-fetoprotein (AFP). HSCs were polygonal in shape after differentiation. The expression of albumin signal decreased and AFP signal increased. The expression of CK18 was continuous in MSCs and HSCs both before and after induction. CONCLUSION: Both MSCs and HSCs have hepatic differentiation capabilities. However, their capabilities are not the same. MSCs can differentiate into mature hepatocyte-like cells, never expressing early hepatic specific genes, while Thy-1.1(+) cells are inclined to differentiate into hepatic stem cell-like cells, with an increasing AFP expression and a decreasing albumin signal. CK18 mRNA is positive in Thy-1.1(+) cells and MSCs, negative in Thy-1.1(-) cells. It seems that CK18 has some relationship with Thy-1.1 antigen, and CK18 may be a predictive marker of hepatic differentiation capability.     

Mechanisms of Immunomodulation by Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have been identified in animals, especially in bone marrow. As stem cells, they have the ability to differentiate into multiple cell types. This potential raises exciting therapeutic possibilities. A recent report described the successful use of MSCs for the treatment of graft-versus-host disease; however, the scientific community has yet to define the molecular mechanisms of immunomodulation by MSCs. This review summarizes what is known and discusses the conflicting data with regard to the mechanisms of immunomodulation by MSCs.