Khorraminejad-Shirazi Mohammadhossein, Dorvash Mohammadreza, Estedlal Alireza, Hoveidaei Amir Human, Mazloomrezaei Mohsen, Mosaddeghi Pouria
Student Research Committee, Shiraz University of Medical Sciences, Shiraz 7134845794, Iran.
World J Stem Cells. 2019 Oct 26;11(10):787-802. doi: 10.4252/wjsc.v11.i10.787.
Tissue engineering has yet to reach its ideal goal, . creating profitable off-the-shelf tissues and organs, designing scaffolds and three-dimensional tissue architectures that can maintain the blood supply, proper biomaterial selection, and identifying the most efficient cell source for use in cell therapy and tissue engineering. These are still the major challenges in this field. Regarding the identification of the most appropriate cell source, aging as a factor that affects both somatic and stem cells and limits their function and applications is a preventable and, at least to some extents, a reversible phenomenon. Here, we reviewed different stem cell types, namely embryonic stem cells, adult stem cells, induced pluripotent stem cells, and genetically modified stem cells, as well as their sources, . autologous, allogeneic, and xenogeneic sources. Afterward, we approached aging by discussing the functional decline of aged stem cells and different intrinsic and extrinsic factors that are involved in stem cell aging including replicative senescence and Hayflick limit, autophagy, epigenetic changes, miRNAs, mTOR and AMPK pathways, and the role of mitochondria in stem cell senescence. Finally, various interventions for rejuvenation and geroprotection of stem cells are discussed. These interventions can be applied in cell therapy and tissue engineering methods to conquer aging as a limiting factor, both in original cell source and in the proliferated cells.
组织工程尚未实现其理想目标，即制造出可盈利的现成组织和器官，设计出能够维持血液供应的支架和三维组织结构，进行恰当的生物材料选择，以及确定用于细胞治疗和组织工程的最有效细胞来源。这些仍是该领域的主要挑战。关于确定最合适的细胞来源，衰老作为影响体细胞和干细胞并限制其功能及应用的一个因素，是一种可预防的现象，并且至少在一定程度上是可逆的。在此，我们综述了不同类型的干细胞，即胚胎干细胞、成体干细胞、诱导多能干细胞和基因修饰干细胞，以及它们的来源，即自体、异体和异种来源。之后，我们通过讨论衰老干细胞的功能衰退以及参与干细胞衰老的不同内在和外在因素来探讨衰老，这些因素包括复制性衰老和海弗利克极限、自噬、表观遗传变化、微小RNA、雷帕霉素靶蛋白（mTOR）和腺苷酸活化蛋白激酶（AMPK）信号通路，以及线粒体在干细胞衰老中的作用。最后，讨论了针对干细胞年轻化和老年保护的各种干预措施。这些干预措施可应用于细胞治疗和组织工程方法，以克服衰老这一限制因素，无论是在原始细胞来源还是在增殖细胞中。
