Zhenwu decoction modulates sphingolipid metabolism reprogramming in chronic kidney disease via the SphK1/S1P/S1PR2 pathway.

ETHNOPHARMACOLOGY RELEVANCE: Zhenwu decoction (ZWD), from the Treatise on Febrile Diseases, has been used in Chinese medicine for "kidney yang deficiency with water retention". Metabolic reprogramming has been recognized as a critical driver of renal inflammation and fibrosis in chronic kidney disease (CKD). However, whether ZWD exerts its renoprotective effects by reversing this metabolic disturbance remains unclear. PURPOSE: This study aims to explore the potential mechanisms by which ZWD influences renal inflammation and fibrosis through sphingolipid metabolic reprogramming in CKD. MATERIALS AND METHODS: The adenine-induced CKD model in mice was used to evaluate the effect of ZWD. Metabolomics analysis was conducted to elucidate the potential mechanisms of ZWD in CKD. Subsequently, the role of SphK1 in CKD was verified using SphK1 inhibitors and Sphk1 overexpression. Additionally, S1pr2 renal tubule conditional knockout mice were used in vivo, and S1PR2 antagonists were used in vitro to clarify the role of S1PR2 in CKD. Finally, the active components of ZWD binding to SphK1 were screened through molecular docking, molecular dynamics simulations and cellular experiments. RESULTS: ZWD markedly inhibited indices of renal function, inflammation, and fibrosis. Metabolomic analysis revealed significant alterations in sphingosine metabolism and various sphingolipids. RT-qPCR analysis demonstrated that ZWD suppressed SphK1 expression in CKD, while the downstream receptor S1PR2 was significantly upregulated. SphK1 inhibition ameliorated renal dysfunction, inflammation, and fibrosis in CKD models. Conversely, overexpression of SphK1 diminished the anti-inflammatory effects of ZWD in vitro, while administration of S1PR2 antagonists could partially salvage the effect. Furthermore, conditional deletion of S1pr2 in renal tubules attenuated inflammation and fibrosis in CKD. Molecular docking and molecular dynamics simulation indicated that 1,2,3,4,6-pentagalloylglucose may be the key compound in ZWD that modulates the SphK1/S1P/S1PR2 pathway. CONCLUSION: ZWD mitigated renal inflammation and fibrosis by modulating sphingolipid metabolism through the regulation of the SphK1/S1P/S1PR2 pathway. These findings suggested a novel approach to identifying potential targets for traditional Chinese medicine in the treatment of CKD.