MicroRNA 33 Potentially Participates in the Development of Goose Fatty Liver via Its Target Gene CROT

Abstract Background Previous studies indicate that microRNA33 (miR-33) and its target gene, CROT, are implicated in hepatic lipid metabolism, but it is unclear whether miR-33 participates in the development of goose fatty liver via CROT. Methods The expression of miR-33 in goose fatty liver, muscle and fat tissues, as well as the mRNA and protein expression of CROT in goose fatty liver was determined by q-PCR or Western-blot. The targeting regulatory relationship between miR-33 and CROT in goose liver cells was validated by miR-33 overexpression and interference assays. The effects of miR-33 mimic and CROT overexpression on lipid deposition and the expression of downstream genes were determined in goose primary hepatocytes. The treatment of high concentrations of glucose and insulin was performed to determine their regulation on the expression of miR-33 and CROT in goose primary hepatocytes. Results Here, data showed that miR-33 expression was significantly increased in the liver, muscle and fat tissues of overfed geese. Consistently, miR-33 mimic promoted lipid deposition in goose primary hepatocytes. Moreover, the regulatory targeting relationship between miR-33 and CROT was validated in goose primary hepatocytes. Consistently, the mRNA and protein expression of CROT were significantly reduced in goose fatty liver. Interestingly, CROT overexpression could induce the expression of fatty acid oxidation associated genes including CRAT, PEX5, EHHADH, CAT and ACOT8 in goose primary hepatocytes, but only the expression of PEX5 was significantly inhibited in goose fatty liver. However, it seemed conflicting that CROT overexpression increased lipid deposition and reduced lipid peroxidation in goose primary hepatocytes. Additionally, high glucose inhibited miR-33 expression and induced CROT expression in goose primary hepatocytes. Conclusions These findings suggest that miR-33 potentially participates in the development of goose fatty liver via CROT, and that miR-33/CROT may partially mediate the effect of glucose in goose liver cells.