Abstract
Acyl-coenzyme A oxidase 1 (ACOX1) is the first and rate-limiting enzyme in peroxisomal fatty acid β-oxidation of fatty acids. Previous studies have reported that ACOX1 was correlated with the meat quality of livestock, while the role of ACOX1 in intramuscular adipogenesis of beef cattle and its transcriptional and post-transcriptional regulatory mechanisms remain unclear. In the present study, gain-of-function and loss-of-function assays demonstrated that ACOX1 positively regulated the adipogenesis of bovine intramuscular preadipocytes. The C/EBPα-binding sites in the bovine ACOX1 promoter region at −1142 to −1129 bp, −831 to −826 bp, and −303 to −298 bp were identified by promoter deletion analysis and site-directed mutagenesis. Electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) further showed that these three regions are C/EBPα-binding sites, both in vitro and in vivo, indicating that C/EBPα directly interacts with the bovine ACOX1 promoter and inhibits its transcription. Furthermore, the results from bioinformatics analysis, dual luciferase assay, site-directed mutagenesis, qRT-PCR, and Western blotting demonstrated that miR-25-3p directly targeted the ACOX1 3’UTR (3’UTR). Taken together, our findings suggest that ACOX1, regulated by transcription factor C/EBPα and miR-25-3p, promotes adipogenesis of bovine intramuscular preadipocytes via regulating peroxisomal fatty acid β-oxidation.
Highlights
Acyl-coenzyme A oxidase (ACOX) and mitochondrial acyl-CoA dehydrogenase belong to the same flavoenzyme superfamily and have evolved from the same progenitor (Kunau et al 1995)
The results showed that over-expression of ACOX1 significant increased levels of triglyceride, whereas significant decreased levels of adenosine 5’-triphosphate (ATP) and reactive oxygen species (ROS) (Fig. 1C, D and E)
We aimed to investigate the association of ACOX1 gene with intramuscular adipogenesis in this study
Summary
Acyl-coenzyme A oxidase (ACOX) and mitochondrial acyl-CoA dehydrogenase belong to the same flavoenzyme superfamily and have evolved from the same progenitor (Kunau et al 1995). ACOX1 is the first and rate-limiting enzyme in peroxisomal fatty acid β-oxidation of fatty acids of all eukaryotes: acyl-CoAs longer than C8 were desaturated to 2-trans-enoyl-CoAs, donating electrons directly to molecular oxygen, generating H2O2 and energy, lost as heat (Li et al 2000, Morais et al 2007). Previous studies have reported that ACOX1 plays an important role in lipid metabolism. Inhibition of ACOX1 was a novel and effective approach for the treatment of high-fat diet or obesity induced metabolic diseases by improving mitochondrial lipid and reactive oxygen species (ROS) metabolism (Zeng et al 2017). The down-expression of PPARα and ACOX1 in liver of rats with alcoholic fatty liver disease suppressed fatty acid metabolism and leaded to triglyceride (TG) deposition in the liver (Tong et al 2016). The down-expression of PPARα and ACOX1 in liver of rats with alcoholic fatty liver disease suppressed fatty acid metabolism and leaded to triglyceride (TG) deposition in the liver (Tong et al 2016). siRNA knockdown of ACOX1 strongly increased the levels of very long chain fatty acids (VLCFA) and neutral lipids (Baarine et al 2012)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
