核纤层蛋白LaminA/C负性调控ASCs增殖促进应力诱导脂肪再生的实验研究

Mechanical stress promotes ASCs proliferation via negative regulation of Lamin A/C expression in expanded prefabricated adipose tissue

目的探索核纤层蛋白LaminA/C对脂肪来源间充质干细胞(Adipose-derived stromal cells,ASCs)机械敏感性的调控作用,及其在应力诱导脂肪再生中的作用机制。方法构建大鼠预扩张脂肪瓣(Expanded Prefabricated Adipose Tissue,EPAT)负压吸引模型,于术后1、4、8周取材制备标本,行组织免疫印迹及免疫化学检测核纤层蛋白(Lamins)表达量变化,用以分析核纤层蛋白表达与应力诱导脂肪再生的相关性;构建体外LaminA/C过表达慢病毒载体并转染ASCs,行体外静态拉伸ASCs处理并采用细胞免疫印迹及免疫荧光检测ASCs增殖程度,用以明确LaminA/C对ASCs增殖的调控作用。结果体内实验发现,负压作用早期,大鼠EPAT内ASCs增殖增多,与此同时,脂肪瓣内LaminA/C表达量明显下降,LaminB1、LaminB2的表达则无明显差异;体外实验发现,过表达LaminA/C可显著抑制体外静态机械应力对ASCs增殖的促进作用。结论新型力学感受器核纤层蛋白通过负性调ASCs增殖参与应力诱导脂肪组织再生过程。

Objective To explore the regulatory effect of Lamin A/C on the mechanical sensitivity of adipose-derived stromal cells(ASCs)proliferation and the mechanism of the stress induced fat regeneration.Methods A rat model of EPAT vacuum aspiration was established.Specimen were collected and prepared at 1,4,8 weeks after operation.And the expression of Lamins A/C were detected by Western blot and immunochemistry to analyze the correlation between the protein expression of Lamins A/C and the stress induced fat regeneration.The overexpression of Lamins A/C lentiviral vectors was constructed in vitro and transfected with ASCs.Static stretching of ASCs was performed in vitro,and the proliferation degree of ASCs was detected by Western blot and immunofluorescence to clarify the regulatory effect of Lamin A/C on the proliferation of ASCs.Results In vivo experiments showed that the proliferation of ASCs in EPAT of rats increased,meanwhile,the expression level of Lamin A/C in EPAT decreased significantly.There was no statistical difference in the expression of Lamin B1 and the expression of Lamin B2.In vitro experiments showed that overexpression of Lamin A/C could inhibit significantly the regulatory effect of static mechanical stress on the proliferation of ASCs in vitro.Conclusions Lamin A/C is involved in the process of stress induced fat regeneration via negatively regulating the proliferation of ASCs.