[Expression of WNK4 gene regulated by aldosterone]

To study the expression and mechanism of WNK4 gene regulated by aldosterone.

Wistar rats were treated with aldosterone and potassium water. Serum aldosterone and ion as well as urine ion were measured. The expression of WNK4 gene in kidney tissues was detected by real-time PCR. Kidney-derived HEK293 cells were cultured, transfected with pGL3-WNK4, and then stimulated by aldosterone. After 24 h of transfection, luciferase activities of the plasmid were detected.

Compared with those of the controls, serum aldosterone and urine K(+) of experimental rats were significantly elevated, whilst urine Na(+) was significantly decreased. And urine Cl(-) was significantly increased only in the group of high K(+). Serum K(+), Na(+) and Cl(-) showed no significant difference. Expression of WNK4 gene in kidney tissues was significantly decreased. The luciferase activity of pGL3-WNK4-484 plasmid has decreased after stimulated with aldosterone, while the activity of pGL3-WNK4-275 showed no change.

Aldosterone can down-regulate the expression of WNK4 through binding with regulatory element in the upstream of the gene.