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

近十年来，脂肪干/祖细胞的生理功能和定位等许多特性已被阐明。脂肪组织翻转非常缓慢，其血管周围祖细胞分化为新的脂肪细胞，取代死亡的脂肪细胞。在十多个国家，使用新鲜分离或培养的含有脂肪祖细胞/干细胞的脂肪源性基质细胞（ASCs）的临床试验正在进行。脂肪干细胞/祖细胞的治疗用途已被证明可以促进血管生成和脂肪组织再生。在细胞凋亡/坏死过程中脂肪细胞释放因子的鉴定将是迈向脂肪组织再生下一阶段的一个突破。软骨膜和骨膜前体的激活仅通过简单的注射就显示出戏剧性的新生，是原位组织工程的理想例子。利用骨髓干细胞/祖细胞的动员剂和捕集剂（引诱剂）引导细胞正确归巢到目标组织的“击中和捕获”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，避免意外行为并诱导ASCs最大潜能的细胞递送方案，以及选择靶向疾病，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.