过表达鸡Klf2促进klf7转录抑制脂肪细胞分化

Overexpression of chicken Klf2 promotes klf7 transcription and inhibits adipocyte differentiation

摘要:

过表达Krüppel样因子2 (Krüppel like factor 2, Klf2)或Klf7可抑制脂肪细胞形成，但是在脂肪组织中Klf2是否调控klf7表达还不清楚。本研究采用油红O染色和蛋白质印迹法技术研究了过表达Klf2对鸡前脂肪细胞分化的影响，结果显示过表达Klf2抑制油酸诱导的前脂肪细胞分化和pparγ表达，同时促进klf7表达(P<0.05)。利用Spearman相关性分析研究人和鸡脂肪组织中klf2和klf7的表达数据之间的关系，发现klf2和klf7的表达数据存在明显的正相关(r>0.1)。荧光素酶报告基因分析显示，在鸡前脂肪细胞中过表达Klf2促进鸡klf7启动子(-241/-91、-521/-91、-1 845/-91、-2 286/-91和-1 215/-91)的活性(P<0.05)；此外，在鸡前脂肪细胞中，klf7启动子(-241/-91)报告基因活性与共转染的klf2过表达质粒的浓度正相关(T_au=0.917 66, P=1.074×10^-7)，过表达Klf2显著促进klf7的mRNA表达水平。综上所述，促进klf7表达可能是Klf2抑制鸡脂肪细胞形成的作用途径之一，鸡klf7翻译起始位点上游-241 bp/-91 bp序列可能介导转录因子Klf2对klf7表达的转录调控作用。

Abstract:

Overexpression of Krüppel like factor 2 (Klf2) or Klf7 inhibits adipocyte formation. However, it remains unclear whether Klf2 regulates klf7 expression in adipose tissue. In this study, oil red O staining and Western blotting were employed to study the effect of Klf2 overexpression on the differentiation of chicken preadipocytes. The results showed that Klf2 overexpression inhibited the differentiation of chicken preadipocytes induced by oleate and the expression of pparγ, while promoted klf7 expression in chicken preadipocytes. Spearman correlation analysis was used to study the correlation between the expression data of klf2 and klf7 in the adipose tissue of both human and chicken. The results showed that there was a significantly positive correlation between the expression of klf2 and klf7 in adipose tissues (r>0.1). Luciferase reporter assay showed that overexpression of Klf2 significantly promoted the activity of chicken klf7 promoter (-241/-91, -521/-91, -1 845/-91, -2 286/-91, -1 215/-91; P<0.05). In addition, the activity of klf7 promoter (-241/-91) reporter in chicken preadipocytes was significantly positively correlated with the amount of klf2 overexpression plasmid transfected (T_au=0.917 66, P=1.074×10^-7). Moreover, Klf2 overexpression significantly promoted the mRNA expression of klf7 in chicken preadipocytes (P<0.05). In conclusion, upregulation of klf7 expression might be one of the pathways that Klf2 inhibits chicken adipocyte differentiation, and the sequence from -241 bp to -91 bp upstream chicken klf7 translation start site might mediate the regulation of Klf2 on klf7 transcription.