SGK1 and Parkinson disease: Gastrointestinal disorders, as one of the early non-motor symptoms of Parkinson's disease, were found in the colon of a mouse model of MPTP-induced PD, where the decrease of SGK1 expression caused the increase of α-syn and Na-K-atpase α1, while increased Na-K-atpase α1 may reduce the demand for Na/K-pumping atpase β1, leading to a decrease in Na/K-pumping atpase β1, which further contributes to disturbances in the gastrointestinal water balance (Seo et al., 2023).