Intrarenal metabolomic investigation of chronic kidney disease and its TGF-β1 mechanism in induced-adenine rats using UPLC Q-TOF/HSMS/MS(E).

Chronic kidney disease (CKD) is becoming a worldwide public health problem. In this study, a kidney metabonomics method based on the ultra performance liquid chromatography/high-sensitivity mass spectrometry with MS(E) data collection technique was undertaken to explore the excretion pattern of low molecular mass metabolites in rat model of adenine-induced chronic renal failure (CRF). Coupled with blood biochemistry and kidney histopathology results, the significant difference in metabolic profiling between the adenine-induced CRF group and the control group by using pattern recognition analysis indicated that changes in global tissue metabolites were occurred. Some significantly changed metabolites like fatty acids, p-cresol sulfate, and indoxyl sulfate have been identified. The results showed that the most important CRF-related metabolites were polyunsaturated fatty acids, indoxyl sulfate, and p-cresyl sulfate. Indoxyl sulfate and p-cresyl sulfate (uremic toxins) were significantly increased in CRF rats. Indoxyl sulfate and p-cresyl sulfate stimulate progressive tubulointerstitial fibrosis by increasing the expression of transforming growth factor-β1 (TGF-β1). These biochemical changes in tissue metabolites are related to the perturbations of fatty acid metabolism and amino metabolism, which may be helpful to further understand the TGF-β1 mechanisms of tubulointerstitial fibrosis. This work shows that the metabonomics method is a valuable tool for studying the essence of CKD.