Study On Differentially Expressed Heptic MiRNAs In A Rat Model Of Dexamethasone-induced Liver Injury

Objective:my study was aimed at investigating the differentially expressed miRNAs of the dexamethasone-induced rats liver injury. Methods:the rats were hypodermic administered with DEX. The rats were divided into two groups:blank control group (CON group, n=8),0.2 ml of saline was subcutaneous injected; dexamethasone group (DEX group, model group, n=8), dexamethasone sodium phosphate injection was subcutaneous injected 2.4 mg/kg of body weight. After 7 d’s dexamethasone -administration, rats were fasting for 24 h. Blood gained and serum isolated was used for determination of fasting ALT, AST, glucose and glycerin trilaurate concentrations. Determined the activity of superoxide dismutase (SOD), the contents of malondialdehyde (MDA) and the contents of GSH (GSH) in liver tissue were. Rat liver tissues were processed to slides using standard techniques. And slides were stained with hematoxylin and eosin. Results:(1) in DEX group, levels of serum ALT, AST and TG were increased significantly, GLU level decreased significantly; (2) the tissue sections showed that compared with the control group (CON) rats, most of the dexamethasone-injected rats liver cells were degenerated. (3) sequencing analysis showed that the expression of rno-mir-21-5p, rno-miR-215, rno-miR-29b-5p, rno-miR-499-5p, rno-miR-34a-5p, rno-miR-203b-5p, rno-miR-100-3p, rno-miR-676, rno-miR-378a-3p and an unconservative miRNA were increased, the expression of rno-miR-672-3p, rno-miR-146a-3p, rno-miR-122-5p, rno-miR-205, rno-let-7b-5p and rno-miR-146b-3p were decreased; q-PCR assay shows that the expression of rno-miR-205, rno-let-7b-5p, rno-miR-672-3p were reduced and the expression of rno-miR-29b-5p, rno-miR-34a-5p, rno-miR-676 were increased. (4) by targeting gene prediction and the functional annotation of differential expressed miRNA, we found biological functions of differentially expressed miRNAs. Conclusion:injection of dexamethasone caused liver damage in rats, miRNAs in rat livers were Differentially Expressed, and these differentially expressed miRNAs were correlated with different biological function.