间充质干细胞治疗宫腔粘连的研究进展

宫腔粘连本质上是损伤或感染等因素导致子宫内膜受损并发生内膜纤维化.宫腔粘连的发病机制包括上皮-间质转化、过度的炎症反应、血管生成障碍、低雌激素状态及子宫内膜干细胞缺失.现有的临床治疗如宫腔镜下粘连分离术、激素治疗、物理屏障植入等,均不能有效改善中重度宫腔粘连患者情况及预防粘连复发.近年研究发现,间充质干细胞在修复组织及...     

干细胞治疗子宫内膜损伤的研究进展

感染因素或宫腔手术操作导致的子宫内膜损伤阻碍胚胎的着床和发育,严重影响妇女的身心健康与生育能力。但目前治疗手段有限且效果欠佳。干细胞具有自我更新和分化潜能,在病变损伤组织的修复过程中发挥重要作用。骨髓间充质干细胞、脐带间充质干细胞、子宫内膜干细胞、脂肪干细胞和人羊膜上皮细胞等多种干细胞治疗子宫内膜损伤已在动物模型和临床研究中开展,并展现出巨大的潜力。干细胞治疗可促进子宫内膜细胞再生,改善子宫内膜厚度和微血管密度,提高受孕率并改善生育结局。干细胞治疗从形态和功能上改善子宫内膜,促进月经和生殖功能的恢复,为治疗子宫内膜损伤提供一种新策略。     

干细胞治疗薄型子宫内膜的研究进展

在辅助生殖技术中,子宫内膜厚度可以反映内膜功能状态,薄型子宫内膜是指子宫内膜厚度不足以获得胚胎着床及临床妊娠。虽然临床对薄型子宫内膜治疗的方式较多,但总体治疗效果欠佳。干细胞因具有多向分化和自我更新的潜能而展现出广阔的发展前景,包括胚胎干细胞、成体干细胞和诱导多能干细胞,随着对干细胞研究的深入,目前有研究诱导干细胞向子宫内膜细胞定向分化并增生,以促进子宫内膜生长,进而用于治疗薄型子宫内膜。现主要就骨髓间质干细胞（BMSCs）、子宫内膜干细胞（EDSCs）、人胚胎干细胞（hESCs）及人脐带华通胶间充质干细胞（WJ-MSCs）在薄型子宫内膜治疗的研究进展以及这4种细胞用于临床治疗的优缺点进行综述。     

间充质干细胞分泌因子调节氧化应激的作用

衰老和疾病发生发展大多伴随氧化应激水平升高，包括多囊卵巢综合征、卵巢储备减少和卵巢早衰等生殖内分泌疾病。干细胞治疗已应用于多种疾病或其临床研究，而间充质干细胞（MSC）相对于胚胎干细胞和诱导多能干细胞具有明显的优势，如应用于子宫内膜粘连、多囊卵巢综合征和卵巢早衰临床治疗的研究。MSC分泌的众多细胞因子对组织细胞内氧化应激具有调节作用。研究发现，白细胞介素6（IL-6）和脑源性神经营养因子（BDNF）能激活核因子E2相关因子2（Nrf2）通路降低氧化应激水平。综述MSC分泌因子的抗氧化应激作用，阐述其可能的细胞内作用机制，为探讨MSC临床应用提供新思路。     

Embryonale Stammzellen der Maus Eigenschaften, Potenzial und Verwendung

During the last few years research on embryonic stem cells has received much public attention due to the fact that these cells are able to differentiate in vitro into many specialized cells and thus may serve as a source for a variety of tissues. The following article focuses on mouse embryonic stem cells (murine ES cells), because research on these cells has given insight into the potential of embryonic stem cells. Murine ES cells are permanent cell lines established from the inner cell mass (ICM) of early embryos (blastocysts). ES cells are undifferentiated pluripotent cells that are able to undergo an unlimited number of cell divisions without loosing the undifferentiated phenotype. The same is true for mouse primordial germ cell lines (murine EG cell lines), that where established from the fetal progenitor cells of primordial germ cells. Mouse embryonic stem cells are used for different purposes. In basic research they are used to study the consequences of mutations within genes that control embryonic development and/or the development of diseases. Because of their ability to differentiate into a variety of specialized cell types, murine ES cells also serve as model systems to establish specific differentiation protocols. In the last few years protocols were established for the in vitro development of undifferentiated embryonic stem cells into differentiated cardiac, skeletal muscle, neural, adipogenic, haematopoietic, endothelial, chondrogenic or vascular smooth muscle cells. Last but not least, studies on mouse ES cells have demonstrated that embryonic cells and their differentiated derivatives can be used to analyse the effects of toxic substances or of pharmaceutical drugs.     

Oxidative stress-induced biomarkers for stem cell-based chemical screening

Stem cells have been considered for their potential in pharmaceutical research, as well as for stem cell-based therapy for many diseases. Despite the potential for their use, the challenge remains to examine the safety and efficacy of stem cells for their use in therapies. Recently, oxidative stress has been strongly implicated in the functional regulation of cell behavior of stem cells. Therefore, development of rapid and sensitive biomarkers, related to oxidative stress is of growing importance in stem cell-based therapies for treating various diseases. Since stem cells have been implicated as targets for carcinogenesis and might be the origin of “cancer stem cells”, understanding of how oxidative stress-induced signaling, known to be involved in the carcinogenic process could lead to potential screening of cancer chemopreventive and chemotherapeutic agents. An evaluation of antioxidant states reducing equivalents like GSH and superoxide dismutase (SOD), as well as reactive oxygen species (ROS) and nitric oxide (NO) generation, can be effective markers in stem cell-based therapies. In addition, oxidative adducts, such as 4-hydroxynonenal, can be reliable markers to detect cellular changes during self-renewal and differentiation of stem cells. This review highlights the biomarker development to monitor oxidative stress response for stem cell-based chemical screening.     

Circulating stem cells and tissue repair

Stem cells are defined as cells that have clonogenic, self-renewing capacities and the capability to differentiate into multiple cell lineages. Whereas embryonic stem cells are derived from mammalian embryos in the blastocyst stage and can generate terminally differentiated cells of all 3 embryonic germ layers, adult human stem cells are capable of maintaining, generating, and replacing terminally differentiated cells within their own specific tissue as a consequence of physiologic cell turnover or tissue injury. The traditional idea of organ-restricted stem-cell differentiation is now being challenged by the suggestion that adult stem cells retain developmental plasticity. Preclinical and clinical studies described in this review provide evidence that within the blood circulate not only progenitor cells that differentiate into hematopoietic cells, but also stem/progenitor cells which can participate in the homeostasis, repair and replacement of solid organ tissues. In addition to the occurrence of cell fusion, there are 4 suggested mechanisms of adult stem cell differentiation into solid organ cells. Preclinical data support these models particularly that of transdifferentiation as the most likely model, allowing stem/progenitor cells to differentiate across lineage, tissue, and germ layer boundaries. There is increasing evidence that we can manipulate in vivo circulating adult stem cells to repair or regenerate solid organ tissue, which offers potential clinical benefit in the treatment of many hereditary and acquired diseases.     

The role of impairment of mesenchymal stem cell function in osteoporotic bone fracture healing

With demographic change and increasing life expectancy, osteoporotic fractures have become one of the most prevalent trauma conditions seen in daily clinical practice. A variety of factors are known to affect the rate of healing in osteoporotic conditions (e.g. both biochemical and biomechanical environment of callus cells). However, the influence of impairment of mesenchymal stem cell function in the osteoporotic condition on bone fracture healing has not been fully understood. In the present study, we develop a mathematical model that quantifies the change in biological processes within the fracture callus as a result of osteoporosis. The model includes special features of osteoporosis such as reduction in mesenchymal stem cell (MSC) number in osteoporotic bone, impaired response of osteoporotic MSCs to their biomechanical microenvironment and the effects of configuration of locking compression plate (LCP) system on healing in this context. The results presented here suggest that mechanically-mediated MSCs differentiation at early stages of healing are significantly affected under osteoporotic conditions, while it is predicted that the flexible fixation achieved by increasing bone-plate distance of LCP could alleviate the negative effects of osteoporosis on healing. The outcomes of this study could potentially lead to patient specific surgical solutions, and thus achieve optimal healing outcomes in osteoporotic conditions.     

间充质干细胞治疗肝病的机制

间充质干细胞(MSCs)的旁分泌机制是MSCs治疗肝病的重要机制.MSCs除了少量分化为肝细胞外,其分泌的一系列营养因子通过减轻炎症反应、抗肝细胞凋亡、抗纤维化、刺激内源性细胞分化增殖和新血管形成等发挥治疗肝病作用,但具体作用机制、有效治疗时间及潜在的副作用有待进一步阐明.此文对MSCs在减轻炎症反应、抗凋亡、抗纤维化等方面的进展进行了综述.     

Wnt信号通路在骨髓间充质干细胞增殖和神经分化中作用的研究进展

骨髓间充质干细胞由于其来源广泛,取材简单,便于外源基因导入,且具有高度扩增、多向分化及低免疫原性的特性,是近年来组织工程、基因治疗和细胞治疗研究中最具吸引力的种子细胞。但目前对其增殖及神经分化的分子机制及信号通路调控知之甚少,寻找调节BMSCs增殖和神经分化的分子信号途径成为新的研究热点。本文概述了BMSCs的生物学特性及Wnt信号通路的组成,探讨Wnt信号通路所形成的网络系统如何调控BMSCs的增殖和神经分化。这将有助于了解BMSCs的增殖和分化机制,从而拓宽BMSCs的应用领域。     

转基因技术及骨髓间充质干细胞在骨缺损修复中的应用与展望

骨髓间充质干细胞（bone mesenchymal stem cells,BMSCs）是一类存在骨髓内的非造血干细胞,具有较强的增殖功能及多向分化潜能.在一些细胞因子的诱导下可以向成骨系细胞、内皮细胞、成纤维系细胞、成软骨系细胞等方向分化,近年来已成为生物学和医学的研究热点.而转基因技术是一项目前较为热门的生物科技技术.本文简要介绍了不同基因如骨形态发生蛋白（bone morphogenetic protein,BMP）、血管内皮细胞生长因子（vascular endothelial growth factor,VEGF）、软骨源性形态发生蛋白1（cartilage-derived morphogenetic protein 1,CDMP-1）、碱性成纤维细胞生长因子（basic fibroblast growth factor,bFGF）、成骨生长肽（osteogenic growth peptide,OGP）等通过转染后对BMSCs增殖、分化的影响及其在骨缺损修复中的应用.     

干细胞向雌性生殖细胞分化的研究进展

干细胞是一类具有自我更新和多向分化潜能的细胞。根据其来源不同,干细胞可分为胚胎干细胞、成体干细胞以及诱导性多能干细胞。生殖细胞系负责跨代传递遗传和表观遗传信息,以确保新的正常个体产生。人类辅助生殖技术(ART)虽可解决部分难治性不孕不育患者的生育问题,但尚不能解决由于卵巢早衰生殖细胞缺乏导致的不孕,如果在体外可以将干细胞定向诱导分化为生殖细胞,则可能通过ART帮助卵巢早衰患者获得健康后代。雌性配子发育经历了多个严格、复杂的过程,包括原始生殖细胞(PGC)特化、增殖、迁移到生殖嵴并最终分化为成熟的卵母细胞。然而具体过程尚不明确。近年来学者已建立了干细胞向雌性生殖细胞分化的体外模型,并取得了长足进步。     

脐带间充质干细胞与脐血造血干细胞临床应用的研究进展

人胚胎干细胞(HESC)系及生殖细胞系的建立,被美国时代周刊(Times)列为20世纪世界十大科技成就之首。脐带间充质干细胞(UC-MSC)和脐血造血干细胞(UCB-HSC)的研究作为其中的一部分,具有广阔的临床应用前景。UC-MSC和UCB-HSC是具有自我更新、分化能力和产生多系或单系特异细胞功能的细胞,位于细胞发育谱系的顶端。笔者拟对UC-MSC和UCB-HSC的来源、生物学特点及其临床应用等方面的进展,综述如下。     

Stem cell strategies for Alzheimer's disease therapy

We have found much evidence that the brain is capable of regenerating neurons after maturation. In our previous study, human neural stem cells (HNSCs) transplanted into aged rat brains differentiated into neural cells and significantly improved the cognitive functions of the animals, indicating that HNSCs may be a promising candidate for cell-replacement therapies for neurodegenerative diseases including Alzheimer's disease (AD). However, ethical and practical issues associated with HNSCs compel us to explore alternative strategies. Here, we report novel technologies to differentiate adult human mesenchymal stem cells, a subset of stromal cells in the bone marrow, into neural cells by modifying DNA methylation or over expression of nanog, a homeobox gene expressed in embryonic stem cells. We also report peripheral administrations of a pyrimidine derivative that increases endogenous stem cell proliferation improves cognitive function of the aged animal. Although these results may promise a bright future for clinical applications used towards stem cell strategies in AD therapy, we must acknowledge the complexity of AD. We found that glial differentiation takes place in stem cells transplanted into amyloid-( precursor protein (APP) transgenic mice. We also found that over expression of APP gene or recombinant APP treatment causes glial differentiation of stem cells. Although further detailed mechanistic studies may be required, RNA interference of APP or reduction of APP levels in the brain can significantly reduced glial differentiation of stem cells and may be useful in promoting neurogenesis after stem cell transplantation.     

Stem cell perspectives in myocardial infarctions

Myocardial infarction is the leading cause of congestive heart failure and death in industrializated countries. The cellular cardiomyoplasty has emerged as an alternative treatment in the regeneration of infarted myocardial tissue. In animals' models, different cellular lines such as cardiomyocites, skeletal myoblasts, embryonic stem cells and adult mesenchymal stem cells have been used, resulting in an improvement in ventricular function and decrease in amount of infarcted tissue. The first three cells lines have disvantages as they are allogenics and are difficult to obtain. The adult mesenchymal stem cells are autologous and can be obtained throught the aspiration of bone marrow or from peripherical circulation, after stimulating with cytokines (G-CSF). The implantation in humans with recent and old myocardial infarction have shown improvements similar to those shown in animal models. These findings encourage the continued investigation in the mechanism of cellular differentiation and implantation methods in infarcted myocardial tissue.     

胶原-聚羟基乙酸与骨髓间质干细胞的细胞相容性研究

目的　研究胶原 -聚羟基乙酸与骨髓间质干细胞的细胞相容性 ,为构建组织工程化肌腱提供实验基础。方法　分离、培养并鉴定骨髓间质干细胞 ,将骨髓间质干细胞置入含胶原 -聚羟基乙酸的DMEM培基中培养 ,设为实验组 ;将骨髓间质干细胞置入纯DMEM培基中培养 ,设为对照组。比较两组细胞的活性和生长情况 ,并对实验组进行超微结构观察。结果　骨髓间质干细胞接种于胶原 -聚羟基乙酸中后可适应材料生长 ,混合培养后 2周生长良好 ,始终保持 89%以上的细胞活力 ,与对照组比较无显著差别 (P >0 0 5 ) ;在 2周的培养过程中实验组细胞数未发生明显改变 ,而对照组从第 4d开始即发生增殖。透射电镜示实验组细胞培养 14d后仍保持旺盛的分泌功能。结论　骨髓间质干细胞与胶原 -聚羟基乙酸的细胞相容性好。以骨髓间质干细胞为种子细胞 ,以胶原 -聚羟基乙酸为支架可在体外预构组织工程化肌腱。     

Application of adipocyte-derived stem cells in treatment of cutaneous radiation syndrome

Cutaneous radiation syndrome caused by local high dose irradiation is characterized by delayed outcome and incomplete healing. Recent therapeutic management of accidentally irradiated burn patients has suggested the benefit of local cellular therapy using mesenchymal stem cell grafting. According to the proposed strategy of early treatment, large amounts of stem cells would be necessary in the days following exposure and hospitalization, which would require allogeneic stem cells banking. In this context, the authors compared the benefit of local autologous and allogeneic adipocyte-derived stem cell injection in a large animal model. Minipigs were locally irradiated using a 60Co gamma source at a dose of 50 Gy and divided into three groups. Two groups were grafted with autologous (n = 5) or allogeneic (n = 5) adipocyte-derived stem cells four times after the radiation exposure, whereas the control group received the vehicle without cells (n = 8). A clinical score was elaborated to compare the efficiency of the three treatments. All controls exhibited local inflammatory injuries leading to a persistent painful necrosis, thus mimicking the clinical evolution in human victims. In the autologous adipocyte-derived stem cells group, skin healing without necrosis or uncontrollable pain was observed. In contrast, the clinical outcome was not significantly different in the adipocyte-derived stem cell allogeneic group when compared with controls. This study suggests that autologous adipocyte-derived stem cell grafting improves cutaneous radiation syndrome wound healing, whereas allogeneic adipocyte derived stem cells do not. Further studies will establish whether manipulation of allogeneic stem cells will improve their therapeutic potential.     

胚胎干细胞及诱导多能干细胞在胚胎毒性研究中的应用

药物对于生殖细胞或者早期胚胎的影响将会引起不孕或者种植前胚胎的发育异常,进而引起胚胎毒性或者是后代的畸形,因此药物的临床应用需要有可靠的实验数据证明其对胚胎的影响,而胚胎干细胞(embryonic stem cell,ESC)由于其无限增殖及多向分化的潜能而作为研究药物胚胎毒性的细胞模型得到广泛应用,以ESC为基础的胚胎干细胞实验(embryonic stem cell test,EST)是获得国际认可的胚胎毒性评价的体外替代方法,但是该实验方法的快速性和准确性存在一定的局限性,目前该细胞模型的研究主要集中于快速性和准确性的优化。新兴的诱导多能干细胞(induced pluripotent stem cells,i PSC),由于具有与ESC相似的增殖和分化特性,目前也被逐步应用于药物胚胎毒性的研究。     

骨髓间充质干细胞与子宫内膜再生

体外受精-胚胎移植的成功受很多因素的影响,其中过薄的子宫内膜会降低子宫内膜容受性,导致胚胎着床失败,结局不良。目前治疗薄型子宫内膜的手段多集中于增加雌激素水平、改善子宫内膜血流以及子宫内膜微创刺激等方面,但疗效并不理想。骨髓间充质干细胞具有自我更新和多向分化的潜能,是最好的成体间充质干细胞来源,可用于治疗多种损伤性疾病。近期研究表明其可向子宫内膜迁移,使子宫内膜厚度增加,并改善子宫内膜容受性,为治疗薄型子宫内膜提供新的思路。     

人脐带间充质干细胞的分离、鉴定及向肝细胞的定向诱导分化

目的 分离纯化人脐带间充质干细胞(UCMSCs),探讨UCMSCs是否能在体外条件下被诱导成为肝细胞样细胞.方法 无菌条件下采集健康新生儿脐带,采用胰酶、胶原酶顺序消化法分离单个细胞,通过贴壁培养方法分离纯化间充质干细胞(MSCs).从形态、表面抗原、成脂肪细胞和成骨细胞分化潜能三方面进行鉴定.随后通过细胞因子诱导的方法将间充质干细胞诱导为肝细胞样细胞.结果 从人脐带中成功分离纯化得到UCMSCs,细胞呈纤维状;表达CD44、CD105、CD73、CD90,不表达与造血细胞和内皮细胞相关的CD34、CD45、CD31等标志物,不表达与移植物抗宿主病相关的HLA-DR等分子;在不同细胞因子作用下,可以被诱导分化为脂肪细胞、成骨细胞和卵圆形肝细胞样细胞.结论 人脐带中含有较丰富的MSCs,在体外条件下可以被诱导为肝细胞样细胞.