过氧化物酶体增殖物激活受体δ在原代小鼠成肌细胞分化过程中对肌球蛋白重链亚型的影响

Effect of peroxisome proliferator-activated receptorδon myosin heavy chain subtypes during the differentiation of primary mouse myoblasts

目的探讨过氧化物酶体增殖物激活受体δ(PPARδ)在成肌细胞分化过程中对肌球蛋白重链(MHC)亚型的影响。方法分离5只新生小鼠原代成肌细胞,设立对照组、PPARδ激动剂组和PPARδ拮抗剂组;各组细胞在分化培养基中培养2、4、6 d收取细胞样品,MHC免疫荧光鉴定各组细胞分化情况;Real-time PCR及免疫荧光检测MHC各亚型表达水平;Western blotting检测各组细胞MHC蛋白表达水平。结果成肌细胞分化过程中PPARδ激动剂组形成的肌管和MHC蛋白表达量高于对照组和PPARδ拮抗剂组。通过比较PPARδ激动剂处理后MHC 4个亚型随时间变化规律发现,分化2 d MHCⅠ、MHCⅡa的上调作用显著;分化4 d MHCⅠ、MHCⅡa、MHCⅡx上调作用显著,其中MHCⅡa上调幅度最大;分化6 d MHCⅠ、MHCⅡa上调作用显著,其中MHCⅡa上调幅度最大。结论PPARδ可以促进小鼠原代成肌细胞分化,在分化过程中显著上调MHCⅡa表达。

Objective To study the effect of peroxisome proliferator-activated receptorδ(PPARδ)on myosin heavy chain(MHC)subtypes during myoblast differentiation.Methods Primary myoblasts from newborn mice were isolated,control group,PPAR delta agonist group and PPAR delta antagonist group were set up.Cell samples were collected at 2,4 and 6 days of cell differentiation in each group.Identification of cell differentiation in each group was made by MHC immunofluorescence;The expression levels of MHC subtypes were detected by Real-time PCR;Western blotting was used to detect the MHC protein expression levels in each group.Results The expression of myotube and MHC protein in PPARδagonist group were higher than that in control group and PPARδantagonist group.By comparing the four MHC subtypes treated with PPARδagonist,it was found that:after 2 days of differentiation,the up-regulation of MHCⅠand MHCⅡa was significant;After 4 days of differentiation,the up-regulation of MHCⅠ,MHCⅡa and MHCⅡx was significant,and the up-regulation of MHCⅡa was the largest;After 6 days of differentiation,the up-regulation of MHCⅠand MHCⅡa was significant,and the up-regulation of MHCⅡa was the largest.Conclusion PPARδpromotes mouse myoblast differentiation and significantly upregulates MHCⅡa expression during differentiation.