间充质干细胞外泌体治疗肺部疾病的研究进展

肺部疾病作为一种呼吸系统常见病,与重工业快速发展、环境污染等密切相关,死亡率极高.近来研究发现间充质干细胞(mesenchymal stem cells,MSCs)能够自主归巢至疾病损伤部位、修复受损组织并参与调节全身炎症和免疫反应,在临床上有较好的应用前景.外泌体是一种细胞外膜囊泡,可能通过调节细胞间通讯参与生物系统...     

间充质干细胞来源的外泌体治疗心肌梗死的研究进展

外泌体是一种小的单层膜结构的细胞外小囊泡,可在细胞间传递蛋白质、脂质、mRNA和miRNA等物质。间充质干细胞来源的外泌体可以作为无细胞系统减少心肌梗死后梗死面积、促进心肌再生并改善心功能,其作用机制可能与激活抗炎和促存活通路、调控细胞自噬和促进血管新生等有关。通过表面修饰或改造来源细胞以提高外泌体的靶向性或改变其内含物质值得深入研究。     

改善间充质干细胞移植治疗心肌梗死疗效方法的研究进展

间充质干细胞(mesenchymal stem cell,MSC)来源广泛,具有易获得、易增殖、免疫原性低等独特优势,是治疗缺血性心脏病,如心肌梗死的可靠细胞来源.然而移植干细胞在梗死区缺血缺氧微环境下会出现存活率低、活性差以及细胞衰老等问题,使其临床应用受到限制.本文将近年来改善间充质干细胞移植治疗心肌梗死疗效的研究...     

间充质干细胞外泌体在阿尔兹海默症治疗中的研究进展

阿尔兹海默症（AD）是一种病理机制复杂,以进行性认知功能障碍为主的中枢神经系统疾病,目前仍缺乏有效的治疗方法。多项研究结果显示,间充质干细胞（MSCs）外泌体能够促进抗炎、调节免疫功能、加强Aβ降解、促进神经细胞轴突生长等,能很好地针对AD的核心病理机制发挥效果从而达到治疗效果。本文主要介绍MSCs外泌体在各项AD病理机制治疗中的研究进展。     

神经干细胞外泌体——神经疾病治疗的新途径

外泌体(exosomes)几乎由所有类型的细胞释放,不同细胞来源的外泌体携带不同的蛋白质、核酸和脂质,参与细胞间的信息交流.最近的研究表明,神经干细胞(neural stem cells,NSCs)分泌的外泌体可参与神经性疾病生理和病理的变化过程,并发挥其潜在的神经调节和修复功能.因此,NSCs分泌的外泌体可以起到治疗...     

水凝胶负载干细胞外泌体在组织再生领域的应用研究进展

近年来,间充质干细胞(mesenchymal stem cells,MSCs)衍生的外泌体在组织再生领域引发许多关注。MSCs衍生外泌体作为细胞间通讯的信号分子,具有天然靶向性强、免疫原性低等特点,其通过MSCs旁分泌途径被细胞吸收,参与调控发挥促进细胞或组织再生功能。水凝胶作为再生医学领域的支架材料,具有良好的生物相容性、降解性等特点。将二者制成复合物联合使用后不仅可以提高外泌体在病变位置的滞留时间,且可通过原位注射等方法提高外泌体到达病变位置的剂量,在病变区域治疗效果显著且持续性改善。文中总结了现阶段外泌体与水凝胶复合物材料共同作用促进组织修复、再生的研究结果,以期为未来组织再生领域中的相关研究工作提供借鉴。     

干细胞与晶状体再生

白内障摘除联合人工晶状体植入术是目前治疗白内障的唯一有效措施。然而,人工晶状体作为替代材料,仍然存在一些如屈光调节力差以及术后眩光等未能克服的缺陷。寻找更理想的晶状体替代物及低等两栖类动物（如蝾螈）强大的晶状体再生能力,为晶状体再生的研究提供了原动力和依据。近年来,人们已探索出将胚胎干细胞/诱导的多能干细胞在体外诱导分化为类晶状体样结构的培养方法,为白内障的治疗开辟了新的思路。晶状体再生的研究为探索晶状体正常发育机制及晶状体疾病的发生和防治提供了新的平台。晶状体再生的成功也将为白内障的防治带来里程碑性的突破。本文拟总结晶状体正常发育过程及其调控机制,回顾国内外对晶状体体内再生能力的研究成果,并对目前人们探索利用胚胎干细胞和诱导的多能干细胞再造晶状体的研究进展作一概述,希望对干细胞与晶状体再生的后续相关研究提供一定的借鉴。     

Progenitor cell therapy for heart disease

Many cell types are currently being studied as potential sources of cardiomyocytes for cell transplantation therapy to repair and regenerate damaged myocardium. The question remains as to which progenitor cell represents the best candidate. Bone marrow-derived cells and endothelial progenitor cells have been tested in clinical studies. These cells are safe, but their cardiogenic potential is controversial. The functional benefits observed are probably due to enhanced angiogenesis, reduced ventricular remodeling, or to cytokine-mediated effects that promote the survival of endogenous cells. Human embryonic stem cells represent an unlimited source of cardiomyocytes due to their great differentiation potential, but each step of differentiation must be tightly controlled due to the high risk of teratoma formation. These cells, however, confront ethical barriers and there is a risk of graft rejection. These last two problems can be avoided by using induced pluripotent stem cells (iPS), which can be autologously derived, but the high risk of teratoma formation remains. Cardiac progenitor cells have the advantage of being cardiac committed, but important questions remain unanswered, such as what is the best marker to identify and isolate these cells? To date the different markers used to identify adult cardiac progenitor cells also recognize progenitor cells that are outside the heart. Thus, it cannot be determined whether the cardiac progenitor cells identified in the adult heart represent resident cells present since fetal life or extracardiac cells that colonized the heart after cardiac injury. Developmental studies have identified markers of multipotent progenitors, but it is unknown whether these markers are specific for adult progenitors when expressed in the adult myocardium. Cardiac regeneration is dependent on the stability of the cells transplanted into the host myocardium and on the electromechanical coupling with the endogenous cells. Finally, the promotion of endogenous regenerative processes by mobilizing endogenous progenitors represents a complementary approach to cell transplantation therapy.     

Different roles of TGF-β in the multi-lineage differentiation of stem cells

Stem cells are a population of cells that has infinite or long-term self-renewal ability and can produce various kinds of descendent cells.Transforming growth factor β(TGF-β) family is a superfamily of growth factors,including TGF-β1,TGF-β2 and TGF-β3,bone morphogenetic proteins,activin/inhibin,and some other cytokines such as nodal,which plays very important roles in regulating a wide variety of biological processes,such as cell growth,differentiation,cell death.TGF-β,a pleiotropic cytokine,has been proved to be differentially involved in the regulation of multi-lineage differentiation of stem cells,through the Smad pathway,non-Smad pathways including mitogen-activated protein kinase pathways,phosphatidylinositol-3-kinase/AKT pathways and Rholike GTPase signaling pathways,and their cross-talks.For instance,it is generally known that TGF-β promotes the differentiation of stem cells into smooth muscle cells,immature cardiomyocytes,chondrocytes,neurocytes,hepatic stellate cells,Th17 cells,and dendritic cells.However,TGF-β inhibits the differentiation of stem cells into myotubes,adipocytes,endothelial cells,and natural killer cells.Additionally,TGF-β can provide competence for early stages of osteoblastic differentiation,but at late stages TGF-β acts as an inhibitor.The three mammalian isoforms(TGF-β1,2 and 3) have distinct but overlapping effects on hematopoiesis.Understanding the mechanisms underlying the regulatory effect of TGF-β in the stem cell multi-lineage differentiation is of importance in stem cell biology,and will facilitate both basic research and clinical applications of stem cells.In this article,we discuss the current status and progress in our understanding of different mechanisms by which TGF-β controls multi-lineage differentiation of stem cells.     

Plant cells — young at heart?

Dolly has become a synonym for one of the greatest breakthroughs in animal reproductive biology: the regeneration of a whole mammal from a somatic cell nucleus. The equivalent experiments in plants — the regeneration of whole plants from single differentiated cells — are comparatively easy. Does this apparent difference in the developmental potential of animal and plant somatic cells reflect mechanistic differences in the regulation and maintenance of their respective cell differentiation?