20-Hydroxyeicosatetraenoic acid regulates the expression of Nedd4­2 in kidney and liver through a neddylation modification pathway.

ABSTRACT

The present study aimed to test whether 20-hydroxyeicosatetraenoic acid (20­HETE) affected neddylation modification of E3­ligase Nedd4­2 (neural precursor cell expressed, developmentally down­regulated 4­like, E3 ubiquitin protein ligase). A cytochrome P450 family 4 subfamily F member 2 (CYP4F2) transgenic mouse model that overproduces 20­HETE in the kidney and the liver was used in the present study. Transgenic mice with high salt intake exhibited increased activation of Nedd4­2­mediated ubiquitin­proteasome pathway. Nedd4­2 expression is increased in the kidney and decreased in the liver of transgenic mice compared with wild­type mice. Subsequently, co­immunoprecipitation analysis indicated that Nedd4­2 was modified by Nedd8, and the level of neddylation on Nedd4­2 was reduced in the kidney and increased in the liver of transgenic mice compared with controls. In addition, sentrin­specific protease 8 (Senp8), a deneddylation enzyme, is expressed higher in the kidney and lower in the liver of transgenic mice compared with wild­type controls. The function of 20­HETE on modulation of Nedd4­2 were also confirmed in mouse M1 kidney and mouse NCTC1469 liver cell lines, and the function was restored by neddylation inhibitor MLN4924 Data from the present study demonstrated that 20­HETE upregulated the expression of Nedd4­2 in the kidney and downregulated expression in the liver through the neddylation modification pathway, at least partly, depending on the effects on Senp8 deneddylation.