棕色化和白色化条件下脂肪组织KLF7的差异表达分析

Differential expression of KLF7 in adipose tissue under diverse conditions of browning and whitening

目的观察棕色化和白色化条件下C57BL/6小鼠棕色脂肪组织(BAT)、腹股沟白色脂肪组织(iWAT)和附睾白色脂肪组织(eWAT)中KLF7蛋白表达水平的变化,为探讨KLF7对脂肪组织功能的影响提供实验基础。方法健康雄性C57BL/6小鼠36只,分为普通饮食组(n=6)和高脂饮食组(n=30),喂养8周,成功诱导肥胖模型后,将高脂饮食组随机分为室温处理组(n=6)、生理盐水处理组(Saline)(n=6)、β3肾上腺素能受体激动剂处理组(n=6)、4℃冷刺激处理组(n=6)和32℃热中性处理组(n=6),连续干预7天。观察不同处理后各组小鼠体重、摄食量、血糖、脂肪组织重量及形态变化,蛋白质免疫印迹法检测小鼠棕色脂肪组织、腹股沟白色脂肪组织和附睾白色脂肪组织中UCP1、PGC-1α和KLF7蛋白表达水平。结果4℃冷刺激处理组小鼠体重显著降低(P<0.01),血糖显著升高(P<0.01)。蛋白质免疫印迹法结果显示:KLF7在小鼠的棕色脂肪组织表达水平最高。高脂饮食组小鼠的棕色脂肪组织和腹股沟白色脂肪组织中KLF7表达水平升高。在β3肾上腺素能受体激动剂和4℃冷刺激处理的棕色化条件下,小鼠的3种脂肪组织中KLF7表达水平升高,而在32℃热中性处理的白色化条件下,3种脂肪组织中KLF7表达水平降低。结论棕色化条件可以促进小鼠3种脂肪组织中KLF7的表达,而32℃热中性的白色化条件下可以抑制3种脂肪组织中KLF7的表达,提示棕色化和白色化条件下可以改变不同脂肪组织中KLF7的蛋白表达水平,进而可能影响脂肪组织的生物学功能。

Objective To observe the changes of KLF7 expression in brown adipose tissue,inguinal white adipose tissue and epididymal white adipose tissue of C57BL/6 mice under browning and whitening conditions,so as to provide an experimental basis for exploring the effect of KLF7 on adipose tissue function.Methods 36 healthy male C57BL/6 mice were divided into normal diet group(n=6)and high-fat diet group(n=30).After feeding for 8 weeks,the obesity model was successfully induced.The high-fat diet group,randomly divided into room temperature treatment group(n=6),normal saline treatment group(n=6),β3 Adrenergic receptor agonist treatment group(n=6),4℃cold stimulation treatment group(n=6)and 32℃thermoneutrality treatment group(n=6),were intervened for 7 days.The weight,food intake,blood glucose,adipose tissue weight and morphological changes of mice in each group were observed after the study.The protein contents of UCP1,PGC-1αand KLF7 in the three adipose tissues of mice were determined by Western blot.Results The body weight of mice treated with 4℃cold stimulation decreased significantly(P<0.01)and the blood glucose increased significantly(P<0.01).The results of western blot showed that the expression level of KLF7 in brown adipose tissue of mice was the highest.The expression of KLF7 in brown adipose tissue and inguinal white adipose tissue increased in high-fat diet group.Under the browning condition ofβ3 adrenergic receptor agonist and 4℃cold stimulation,the expression level of KLF7 in three kinds of adipose tissue of mice increased,while under the whitening condition of 32℃thermoneutrality,the expression level of KLF7 in the three kinds of adipose tissue decreased.Conclusion The browning condition can promote the expression of KLF7 in the three kinds of adipose tissue of mice,while the 32℃thermoneutrality whitening condition can inhibit the expression of KLF7 in the three kinds of adipose tissue,suggesting that conditions of browning and whitening can change the protein expression level of KLF7 in different adipose tissues,which may affect the biological function of adipose tissue.