Characterization of the expression profiles of adipogenesis-related factors, ZNF423, KLFs and FGF10, during preadipocyte differentiation and abdominal adipose tissue development in chickens

Abstract

Adipogenesis is controlled by a complicated process involving certain transcriptional events. In chicken adipogenesis, peroxisome proliferator-activated receptor γ (PPARγ) is a key regulator of preadipocyte differentiation and abdominal fat accumulation. However, in a recent study in mammals, some novel factors related to regulation of adipogenesis, including preadipocyte differentiation, were identified in mammals. Therefore, in this study, we aimed to determine the expression profiles of these mammalian adipogenesis-related factors, such as zinc-finger protein 423 (ZNF423), Krüppel-like factor -2, -5, and -15 (KLF-2, -5, -15), and FGF10, in the chicken (Gallus gallus). Specifically, we analyzed their expression in primary preadipocyte differentiation in vitro and also analyzed their tissue distribution and their temporal expression in adipose tissue development in vivo. During chicken adipocyte differentiation, the gene expression of ZNF423, KLF-2, KLF-5 and FGF10 was found to rapidly decrease in the early stage of preadipocyte differentiation. Expression of ZNF423 then increased in the late stage of differentiation. KLF-15 expression increased in a time-dependent manner for 48 h. Protein expressions of these factors were reflected by Western blot analysis. High levels of aP2, PPARγ and FGF10 mRNA were found in adipose tissue. In addition, aP2, PPARγ and ZNF423 mRNA levels in the adipose tissue were elevated at days 10 and 20. These expression profiles of the adipogenesis-related factors in chicken are, in part, different from mammalian adipogenesis but this seems to reflect the differences in the regulation of adipogenesis and in adipose tissue functions between avians and mammals.