Parallel metabolomic and transcriptomic profiling reveals the cytotoxic mechanism of protein-bound uremic toxin p-cresol sulfate via disruption of glutathione and glycerophospholipid metabolism in MC3T3-E1 osteoblasts

BACKGROUND: Chronic kidney disease-mineral bone disorder (CKD-MBD), a common complication of chronic kidney disease (CKD), leads to vascular calcification, osteoporosis, and electrolyte disturbances, impacting patient survival and quality of life. Conventional dialysis poorly removes protein-bound uremic toxins like p-cresyl sulfate (PCS), which are linked to CKD-MBD. This study combined metabolomics and transcriptomics to explore PCS's cytotoxic mechanisms in CKD-MBD for better clinical management. METHODS: Using MC3T3-E1 osteoblasts treated with or without PCS, metabolic changes were analyzed via ultra-high performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS), and transcriptomic changes through RNA sequencing (RNA-seq). RESULTS: UHPLC-QTOF/MS identified 74 significantly altered metabolites and 15 disrupted metabolic pathways in PCS-treated osteoblasts. RNA-seq revealed 3,679 differentially expressed genes, with pathway analysis indicating significant disruptions in glutathione and glycerophospholipid metabolism, and alterations in cell apoptosis, cell cycle, and DNA repair processes. CONCLUSIONS: Parallel metabolomics and transcriptomics profiling showed PCS-induced disruptions in glutathione and glycerophospholipid pathways are central to cellular metabolic dysfunction in CKD-MBD. These insights highlight the potential of multi-omics to elucidate uremic toxin pathophysiology, providing a foundation for improved CKD-MBD management.