脂肪组织来源干细胞提高游离脂肪移植存活率的研究

目的 探讨脂肪组织来源干细胞移植在体内促进游离移植脂肪组织的再血管化,提高移植脂肪组织存活率的可行性.方法 自人体吸脂术中脂质部分分离、培养AScs,行成脂、骨和软骨分化.将ASCs以DiI标记后与人体吸脂术获得的脂肪组织混合移植于18只裸鼠背部,裸鼠背部随机注入3组移植物:ASCs组(A组)、胰岛素组(B组)及培养基对照组(C组).术后6个月观察移植物情况,通过组织观察、HE染色和免疫组化进行分析.结果 抽脂术脂质部分能获取大量的ASCs,能分化成脂肪、成骨和软骨细胞.术后6个月3组移植脂肪的湿重分别为A组(165.97±5.51)mg,B组(93.42±5.12)mg,C组(67.64±5.09)lIIg.A组移植脂肪的存活率高于B、C组(P=0.000).纤维化程度的测定,"网格点计数"3组移植物的点个数分别为A组(152.2±9.8)个/10HF,B组(743.9±20.4)个/10HF,C组(892.2±16.5)个/10HF.A组移植脂肪的纤维化及坏死程度低于B、C组(P=0.000).免疫组化证实:ASCs散在分布于部分脂肪细胞及小叶间隔中,ASCs在体内能够部分转化为血管内皮细胞.结论 脂肪组织来源干细胞移植在体内可促进游离移植脂肪组织的再血管化,提高移植脂肪组织的存活率并改善了移植物的质地.AsCs辅助移植可能是一种较为理想的细胞疗法.

Experimental study of the effect of adipose tissue derived stem cells on the survival rate of free fat transplantation

Objective To investigate the feasibility of using adipose tissue derived stem cells(ASCs) to promote neovascularization and survival rate of free fat transplantation. Methods ASCs were isolated from aspirates from human liposuction and cultured in vitro. The cells were incubated in adipogenic, osteogenic, and chondrogenic medium for 2-4 weeks to induce adipogenesis, osteogenesis and chondrogenesis, respectively. ASCs were labelled by DiI. ASCs(A group), Iasulin(B group), Medium (C group) were respectively mixed with free fat graft from aspirates. The mixtures were injected subcutaneously at the three random points on the back of eighteen 4～6 week-old nude mice. Transplanted fat tissue was harvested after 6 months. The grafts were assessed by morphological observation, HE staining and immunohistochemistry. Results ASCs can be easily harvested from liposuction aspirates and differentiate into adipogenic, osteogenic, chondrogenic lineages. The wet weight of transplanted fat tissue in ASCs group was (165.97±5.51) mg, significantly higher than that in the insulin group (93.42±5.12) mg and control group(67.64 ±5.09) ±g (P = 0.000). The rate of fibrosis and steatonecrosis in ASCs group was(152.2±9.8)/10HF, significantly lower than that in the Insulin group (743.9 ±20.4)/10HF and control group (892.2±16.5)/10HF(P = 0.000). DiI labelled ASCs were found between adipocytes and in the connective tissue in free transplanted fat tissue, and some of these cells were immunopositive for untihuman CD31 and FITC, suggesting differentiation into vascular endothelial cells. Conclusions ASCs can differentiate into vascular endothelial ceils and contribute to angiogenesis in free transplanted fat tissue. ASCs can increase the survival rate and decrease the rate of fibrosis and steatonecrosis of free transplanted fat tissue. These findings suggest that ASCs-assisted transplantation may be an ideal cell therapy.