干细胞来源与组织来源小细胞外囊泡诱导脂肪新生的比较

Comparison of small extracellular vesicles derived from stem cells and tissue on de novo adipose regeneration

背景:再生医学近几十年的发展,使胞外囊泡诱导脂肪组织再生成为修复软组织缺损的可行方法。但由于实验模型不同以及胞外囊泡使用剂量不同,目前仍无法对不同来源胞外囊泡在脂肪再生中的应用效果进行定量比较。目的:比较干细胞来源小细胞外囊泡与组织来源小细胞外囊泡在体内诱导脂肪新生的效果。方法:采用超速离心法提取脂肪干细胞来源小细胞外囊泡和脂肪组织来源小细胞外囊泡,采用纳米颗粒跟踪分析、透射电镜和Western blot鉴定比较2种小细胞外囊泡的数量、粒径、形态和标志蛋白表达;使用定制硅胶管建立C57小鼠皮下脂肪新生定量评估模型,通过细胞计数和苏木精-伊红染色比较2种小细胞外囊泡体内促进脂肪组织新生的效果。结果与结论:①通过超速离心法提取2种小细胞外囊泡,粒径均位于50-200 nm之间,在透射电镜下均为典型的圆形,均表达小细胞外囊泡的特征性蛋白CD81、CD63、TSG101;②使用定制硅胶管,将等粒子数小细胞外囊泡与Matrigel凝胶混合于硅胶管中植入小鼠背部皮下,建立小鼠体内无细胞、可定量的脂肪新生模型;③植入后3,7 d,硅胶管内容物苏木精-伊红染色和细胞计数显示,加入了小细胞外囊泡的2组都比空白对照组募集到更多的宿主细胞,且脂肪组织来源小细胞外囊泡组优于脂肪干细胞来源小细胞外囊泡组;④体内植入4周的硅胶管内容物苏木精-伊红染色显示,小细胞外囊泡促进脂肪新生,且脂肪组织来源小细胞外囊泡组优于脂肪干细胞来源小细胞外囊泡组。以上结果表明,组织来源小细胞外囊泡促进脂肪新生的效果优于干细胞来源小细胞外囊泡。

BACKGROUND:De novo adipose regeneration induced by small extracellular vesicles has become a promising method for repairing soft tissue defects.However,due to different animal models and small extracellular vesicle application dosages,it is difficult to quantitatively compare the therapeutic effect of small extracellular vesicles from various sources on adipose regeneration.OBJECTIVE:To compare the regenerative effects of small extracellular vesicles derived from stem cells and small extracellular vesicles from tissue.METHODS:Small extracellular vesicles derived from adipose-derived stem cells and from adipose tissue were isolated by ultracentrifugation.The particle number,particle size,morphology,and protein expression of small extracellular vesicles were identified by nanoparticle tracking analysis,transmission electron microscopy and western blot assay.A quantitative and evaluative subcutaneous model for adipose regeneration in C57 mice was established using a customized silicone tube.The regenerative effects of induced de novo adipose were compared by cell counting and hematoxylin-eosin staining.RESULTS AND CONCLUSION:(1)Small extracellular vesicles derived from adipose-derived stem cells and from adipose tissue were isolated by ultracentrifugation.Both small extracellular vesicles were round-shape in transmission electron microscopy with particle size between 50-200 nm,and abundant with the small extracellular vesicles marker protein CD81,CD63 and TSG101.(2)An equal number of small extracellular vesicles were mixed with matrigel in customized silicone tubes,implanted subcutaneously in the back of mice to establish a cell-free and quantifiable adipose regeneration model.(3)On days 3 and 7 after implantation,the results of cell counting and hematoxylin-eosin staining showed that both small extracellular vesicle groups recruited more host cells than the blank group,and the small extracellular vesicles derived from adipose tissue group were superior to the small extracellular vesicles derived from adipose-derived stem cell group.(4)4 weeks after implantation,hematoxylin-eosin staining of the contents in silicone tubes showed that small extracellular vesicles induced de novo adipose regeneration in vivo,and the small extracellular vesicles derived from adipose tissue group were superior to the small extracellular vesicles derived from adipose-derived stem cell group.The above results indicated that small extracellular vesicles derived from tissues have a superior effect on inducing de novo adipose regeneration compared to small extracellular vesicles derived from stem cells.