Functions of adipose-derived stem cells in remodeling of tissue and vasculature

在过去的十年中，脂肪干/祖细胞的许多特征，如生理功能和定位，已经被阐明。脂肪组织翻转非常缓慢，其血管周围的前体细胞分化为新的脂肪细胞，取代死亡的脂肪细胞。使用新鲜分离或培养的含有脂肪前体/干细胞的脂肪基质细胞(ASCs)进行的一些临床试验正在十多个国家进行。脂肪干细胞/前体细胞的治疗应用已被证明可以促进血管生成和脂肪组织再生。识别脂肪细胞在凋亡/坏死时的释放因子将是脂肪组织再生进入下一阶段的突破口。软骨膜和骨膜中前体的激活只需一次简单的注射就能显示出戏剧性的新生，是原位组织工程的理想范例。使用骨髓干细胞/祖细胞的激动剂和捕捉器(引导剂)来引导细胞正确地归巢到靶组织中的“击中并抓住”策略可能是我们未来促进干细胞操纵的方向。精心设计激活ASCs的微环境，避免ASCs的意外行为和诱导ASCs的最大潜能的细胞递送方案，以及靶向疾病的选择，将是临床应用成功的关键。

Many features of adipose stem/progenitor cells, such as physiological functions and localization, have been clarified in the past decade. Adipose tissue turns over very slowly and its perivascular progenitor cells differentiate into new adipocytes, replacing dead adipocytes. A number of clinical trials using freshly isolated or cultured adipose-derived stromal cells(ASCs) containing adipose progenitor/stem cells are ongoing in more than ten countries. Therapeutic use of adipose stem/progenitor cells has been shown to promote angiogenesis and adipose tissue regeneration. Identification of adipocyte releasing factors upon apoptosis/necrosis would be a break-through to step up to the next stage for adipose tissue regeneration. Activation of precursors in perichondrium and periosteum shows a dramatic neogenesis by only a simple injection and an ideal example of in situ tissue engineering. The "hit and catch" strategy using a mobilizer of bone-marrow stem/progenitor cells and a catcher(attractants) to lead the cells to proper homing into the target tissue may be our future direction of promote manipulation of stem cells. Careful design of microenvironment activating ASCs, cell delivery protocol to avoid unexpected behavior and induce maximal potential of ASCs, and selection of target diseases, will be critical to the success of clinical applications.