脂肪干细胞局部注射改善淋巴水肿的实验研究

目的 研究脂肪干细胞 (adipose derived stem cells, ADSCs)体内减轻炎性反应治疗淋巴水肿的可行性及作用机制,为淋巴水肿疾病的干细胞治疗探索新的思路。方法 提取小鼠皮下脂肪干细胞,体外培养、扩张至3~5代。建立淋巴水肿鼠尾模型,手术阻断鼠尾深、浅淋巴回流,造模当天,于皮下注射ADSCs或磷酸盐缓冲液(phosphate buffered solution,PBS),ADSCs组共20只小鼠,PBS对照组共30只小鼠。术后3周,分别用HE染色、Whole mount-BODIPY染色、Masson染色、免疫荧光染色检测鼠尾皮下组织/脂肪厚度、纤维化程度、淋巴管形态,干预后8周,FITC-Dextran检测淋巴回流。结果 ADSCs组淋巴水肿缓解,鼠尾体积在术后4周内较对照组减小;皮下脂肪厚度降低约40%;皮下组织的纤维化缓解,Masson染色结果显示胶原纤维所占面积比例下降约20%;高倍镜视野下的淋巴管数量未发生变化,但是横截面积减小约60%;FITC-Dextran检测淋巴回流发现,ADSCs组荧光染料通过手术切口明显多于PBS对照组。结论 ADSCs局部注射后,可缓解淋巴水肿。

Adipose derived stem cells ameliorate experimental lymphedema

Objective To explore the feasibility of locally injected adipose derived stem cells (ADSCs) in treating lymphedema via reduction of CD4⁺T cells. Methods ADSCs isolated from subcutaneous adipose tissue of C57BL/6J mice were cultured in vitro to passage 3 to 5. Tail lymphedema was created on C57BL/6J mice by disconnecting both superficial and deep lymphatic vessels. Mice in total of 50 that received surgery were randomly assigned to two groups immediately after surgery. Animals in group 1 were injected subcutaneously with 15μL of PBS as control. Mice in group 2 were injected with 5×10⁵ nADSCs suspended in 15 μL of PBS. At every week after ADSCs injection, tail volumes of mouse tails were calculated. Tails were harvested at 3 weeks after injection. Subcutaneous adipose thickness, degree of fibrosis, lymphatic morphology and lymphatic reflux, were detected by Whole mount-BODIPY staining, Masson trichrome staining, immunofluorescence, and FITC-Dextran respectively. Results Transfer of ADSCs demonstrated an amelioration of lymphedema, which corresponded to a decrease in tail volume and nearly 40% decrease in adipose tissue thickness, as compared with controls. Using Masson trichrome staining, we found a 20% reduced collagen deposition after ADSCs transfer. Furthermore, the dramatic expansive lymphatic vessels were reduced by about 60% in area, while the total numbers were not changed. Transport function of lymphatic vessels was improved as evidenced by an increase in the amount of dye passing through the surgical incision within a limited time. Conclusion Local application of ADSCs alleviates lymphedema.