RXRα Positively Regulates Expression of the Chicken PLIN1 Gene in a PPARγ-Independent Manner and Promotes Adipogenesis

Yuhang Sun; Guiying Zhai; Rui Li; Weinan Zhou; Yumao Li; Zhiping Cao; Ning Wang; Hui Li; Yuxiang Wang

doi:10.3389/fcell.2020.00349

RXRα Positively Regulates Expression of the Chicken PLIN1 Gene in a PPARγ-Independent Manner and Promotes Adipogenesis

Front Cell Dev Biol. 2020 May 14:8:349. doi: 10.3389/fcell.2020.00349. eCollection 2020.

Authors

Yuhang Sun^{1

2

3}, Guiying Zhai^{1

2

3}, Rui Li^{1

2

3}, Weinan Zhou^{1

2

3}, Yumao Li^{1

2

3}, Zhiping Cao^{1

2

3}, Ning Wang^{1

2

3}, Hui Li^{1

2

3}, Yuxiang Wang^{1

2

3}

Affiliations

¹ Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin, China.
² Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin, China.
³ College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.

Abstract

Perilipin1 (PLIN1), the most abundant lipid droplet (LD)-associated protein, plays a vital role in regulating lipid storage and breakdown in adipocytes. Recently, we found that the overexpression of PLIN1 promotes chicken preadipocyte lipid accumulation. However, the mechanisms by which transcription of the chicken PLIN1 gene is regulated remain unknown. In this study, we investigated the role of retinoid X receptor α (RXRα) in transcription of the chicken PLIN1 gene. Notably, reporter gene and expression assays showed that RXRα activates transcription of the chicken PLIN1 gene in a PPARγ-independent manner. Furthermore, promoter deletion and electrophoretic mobility shift assay (EMSA) analysis revealed that the chicken PLIN1 gene promoter region (-774/-785) contains an RXRα-binding site. Further study demonstrated that RXRα overexpression promotes differentiation of an immortalized chicken preadipocyte cell line (ICP1), causing a concomitant increase in PLIN1 transcripts. Taken together, our results show for the first time that RXRα activates transcription of the chicken PLIN1 gene in a PPARγ-independent manner, which might be at least in part responsible for RXRα-induced adipogenesis.

Keywords: PLIN1; adipogenesis; chicken; retinoid X receptor α; transcriptional regulation.