Research on the Regulation of Potassium-Related Channels in Kidney by Testosterone through WNK1 Kinase

Abstract: In this paper， the mechanism of changes in blood pressure caused by testosterone through withno- lysine kinase 1 (WNK1) kinase regulation of potassium-related channels in kidney have been investigated. The experimental models are established on normal male mice， castrated male mice and castrated males injected with testosterone. The phenotype was measured. The protein and mRNA expressions of WNK1 kinase and renal potassium ion channels renal outer medullary potassium (ROMK)， large conductance Ca2+-activated K+ (BK) and Na- K-2Cl cotransporter (NKCC2) mediated by WNK1 were detected by western blot (WB) and real-time quantitative polymerase chain reaction detecting system (QPCR) technology. Meanwhile， immunofluorescence technique was used to verify the results. The phenotypic results showed that the blood potassium increase while the blood pressure decrease in castrated male mice. When the castrated male mice received testosterone， blood potassium decreased and blood pressure increased. WB and QPCR results showed that WNK1 increased in castrated male mice compared to normal male mice， and the normal expression of WNK1 was restored in castrated male mice with the testosterone injected. In the castrated male mice， the potassium channel ROMK decreased， while BK-α and NKCC2 increased. The expression of three potassium-related channels in castrated male mice are recovered after testosterone injection. Immunofluorescence results are consistent with the results of QPCR and WB. The WB results of phospho-WNK1 showed that phospho-WNK1， compared with normal male mice， elevated in ovariectomized male mice， and phospho-WNK1 decreased in castrated male mice after testosterone injection. The experimental results indicate that testosterone causes changes in WNK1， p-WNK1， ROMK， BK-α， and NKCC2. WNK1 inhibitor injection experiments showed that the expression of ROMK in the renal ion channel downstream of WNK1 increased， and the expression of BK decreased. Furthermore， the sodium-potassium chloride cotransporter 2 decreased， which indicates that WNK1 can regulate ROMK， BK and NKCC2. These findings indicate that testosterone can regulate blood potassium in renal potassium-related channels through WNK1.

CSTR: 32200.14.cjcb.2019.03.0019