Regulation of triglyceride synthesis by estradiol in the livers of hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂)

Publication date: Available online 29 August 2019Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular BiologyAuthor(s): Xiaojin Zhang, Zhuojun Han, Huan Zhong, Qinglang Yin, Jun Xiao, Fenghua Wang, Yi Zhou, Yongju LuoAbstractEstradiol (E2) is a sex steroid hormone that modulates multiple physiological processes in teleosts. The aim of this study was to explore the role of E2 in the hepatic lipid metabolism of hybrid tilapia. The hybrid tilapias were injected with different concentrations of E2 (0 mg/kg, 10 mg/kg, 25 mg/kg and 50 mg/kg) and ICI 182,780 (ICI) (35 mg/kg) (an E2 receptor antagonist). Subsequently, the liver lipid depositions were analyzed by tissue sections with oil red O staining. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and nonesterified fatty acids (NEFAs) were assayed from the fish in different groups. Genes related to very low-density lipoprotein (VLDL) assembly, lipoprotein lipase and lipoprotein receptors, fatty acid uptake and triacylglycerol metabolism were determined by quantitative RT-PCR. The results showed that 50 mg/kg E2 injections enlarged the lipid droplets significantly. Simultaneously, the E2 injections tended to upregulate TC, TG, LDL, and HDL in the serum. The 50 mg/kg E2 group showed a significantly higher expression of the VLDL assembly genes but depressed levels of LDLR and LRP1. In addition, FABP3, FABP11a and DGAT2 were signi...
Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology - Category: Molecular Biology Source Type: research