UC Davis

β-Diketone antibiotics (DKAs) are widely used in human and veterinary medicine to prevent and treat a large variety of infectious diseases. Long-term DKA exposure to zebrafish can result in lipid metabolism disorders and liver function abnormalities. Based on our previous miRNA-seq analyses, miR-144 and miR-125b were identified as target genes regulating lipid metabolism. DKA-exposure at 12.5 and 25 mg/L significantly increased the expressions of miR-144 and miR-125b. The expression levels for the two miRNAs exhibited an inverse relationship with their lipid-metabolism-related target genes (ppardb, bcl2a, pparaa and pparda). Over-expression and inhibition of miR-144 and miR-125b were observed by micro-injection of agomir-144, agomir-125b, antagomir-144 and antagomir-125b. The over-expression of miR-144 and miR-125b enhanced lipid accumulation and further induced lipid-metabolism-disorder syndrome in F1-zebrafish. The expression of ppardb and bcl2a in whole-mount in situ hybridization was in general agreement with results from qRT-PCR and was concentration-dependent. Oil red O and H&E staining, as well as related physiological and biochemical indexes, showed that chronic DKA exposure resulted in lipid-metabolism-disorder in F0-adults, and in F1-larvae fat accumulation, increased lipid content, abnormal liver function and obesity. The abnormal levels of triglyceride (TG) and total cholesterol (TCH) in DKA-exposed zebrafish increased the risk of hyperlipidemia, atherosclerosis and coronary heart disease. These observations improve our understanding of mechanisms leading to liver disease from exposure to environmental pollution, thereby having relevant practical significance in health prevention, early intervention, and gene therapy for drug-induced diseases.