Arginine vasopressin and angiotensin II coregulate Aquaporin 2 expression in M-1 cells

Objective: The aim of this study was to explore the impact of arginine vasopressin (AVP) and angiotensin II (Ang II) on Aquaporin 2 (AQP2) expression in M - 1 cells.

Methods: M - 1 cells were stimulated with desmopressin (dDAVP) and Ang II, followed by treatment with tolvaptan and losartan. The expression and protein levels of V2R, AT1R, AQP2, and p-S256AQP2 were measured via ELISA, western blotting, RT-qPCR, and immunofluorescence. Molecular docking was employed to assess the interaction affinities between Ang II, losartan, and V2R, as well as dDAVP, tolvaptan, and AT1R.

Results: dDAVP stimulation significantly upregulated the expression of V2R, AQP2, and p-S256AQP2 in M - 1 cells. Ang II stimulation also resulted in significant increases in AT1R, AQP2, p-S256AQP2 expression. Interestingly, we found that dDAVP could stimulate the expression of AT1R, and Ang II could stimulate the expression of V2R. Following tolvaptan treatment, the expression levels of V2R, AQP2, p-S256AQP2, and AT1R were significantly reduced. Similarly, losartan treatment led to a marked decrease in AT1R, AQP2, p-S256AQP2, and V2R expression. Molecular docking analysis confirmed the binding interactions between Ang II and losartan with V2R, as well as between dDAVP and tolvaptan with AT1R.

Conclusion: AVP and Ang II collaboratively regulate the expression of V2R and AT1R in M - 1 cells, influencing AQP2 expression.