Chao Huang, Zhi Luo, Christer Hogstrand, Feng Chen, Xi Shi, Qi-Liang Chen, Yu-Feng Song and Ya-Xiong Pan
The present study was conducted to determine the effect and mechanism of waterborne Zn exposure influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta. S. hasta were exposed to four waterborne Zn concentrations (0.005, 0.18, 0.36 and 0.55 mg l-l, respectively) for 60 days. Sampling occurred at days 20, 40 and 60, respectively. Zn exposure increased Zn content, declined hepatic lipid content, and reduced lipogenic enzyme activities, including 6PGD, G6PD, ME and FAS. At days 20 and 60, Zn exposure decreased hepatic mRNA levels of 6PGD, G6PD, ME, FAS, ACCα, ACCβ, hormone-sensitive lipase (HSL)a, HSLb, SREBP-1, PPARα and PPARγ. However, the mRNA levels of CPT 1 and adipose triglyceride lipase increased following Zn exposure. On day 40, Zn exposure reduced hepatic mRNA expression of 6PGD, G6PD, ME, FAS, ACCα,ACCβ, HSLa, HSLb, SREBP-1 and PPARγ but increased mRNA expression of CPT 1, adipose triglyceride lipase and PPARα. For the first time, the present study provided evidence that chronic Zn exposure differentially influenced mRNA expression and activities of genes and enzymes involved in lipogenic and lipolytic metabolism in a duration-dependent manner, and provided new insight into the relationship between metal elements and lipid metabolism.