ZBTB16 Overexpression Enhances White Adipogenesis and Induces Brown-Like Adipocyte Formation of Bovine White Intramuscular Preadipocytes.

Background/aims: Our study aims to characterize functions of ZBTB16 gene in the process of intramuscular fat (IMF) deposition and metabolism of bovine, thereby providing insights into mechanisms for the use of ZBTB16 in fat management.

Methods: Primary preadipocytes derived from bovine IMF tissue were isolated and used as the in vitro cell model. An adenovirus Ad-ZBTB16 was transfected into bovine preadipocytes to overexpress the ZBTB16 gene. By using real-time quantitative PCR (RT-qPCR), western blotting, Oil Red-O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity assay, and cell counting kit-8 (CCK-8) test, adipogenic and proliferative signals in adipocytes were monitored to investigate effects of ZBTB16 on adipogenesis of bovine preadipocytes.

Results: After transfection, mRNA and protein levels of ZBTB16 gene were significantly increased. Enhanced ZBTB16 significantly promoted preadipocyte differentiation, as evidenced by accelerated lipid accumulation, enhanced GPDH activity, consistently increased mRNA expressions of adipogenic key transcription factors PPARγ, C/EBPα, FABP4, and ADIPOQ, and markedly increased protein expressions of PPARγ and FABP4. No difference was observed concerning proliferation of preadipocytes after treatment with Ad-ZBTB16. Furthermore, relative mRNA levels of brown adipocyte selective genes (PRDM16, UCP1, Cidea, Cox8b, and PGC-1α) and beige adipocyte selective genes (CD137, TMEM26, and Tbx1) as well as UCP1 protein expression were significantly increased by Ad-ZBTB16. Meanwhile, Ad-ZBTB16 treatment remarkably induced mitochondrial biogenesis and increased relative mitochondrial DNA (mtDNA) copy number in bovine adipocytes.

Conclusion: These results suggest that ZBTB16 overexpression can promote white adipogenesis and induce brown-like adipocyte formation for bovine white intramuscular preadipocytes.