Untargeted lipidomics based on UPLC-QTOF-MS/MS and structural characterization reveals dramatic compositional changes in serum and renal lipids in mice with glyoxylate-induced nephrolithiasis

Nephrolithiasis is a systemic metabolic disease with a worldwide incidence that is increasing yearly, as well as a high recurrence rate; however, this disease's pathogenesis has not been thoroughly elucidated to date. Several epidemiological studies have shown that the risk for developing kidney stones increases in people with dyslipidemia. To explore the mechanism of lipid-induced kidney stones, we established a mouse model for renal urolithiasis based on intraperitoneal injections of glyoxylate (120 mg/kg/d). Lipidomics based on ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) was performed to determine the changes in lipid metabolism in serum and kidneys. We screened 179 and 196 different lipid metabolites in the kidneys and serum, respectively, including fatty acyls, glycerophospholipids, sphingolipids, glycerolipids and prenol lipids. We found that polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid, and docosahexoenoic acid, and ceramides and lysophosphocholines mediated inflammatory responses and that the oxidative stress induced by oleylethanolamine and glycerophosphoethanolamine plasmalogens is closely related to the development of kidney stones. These results provide strong evidence for the relationship between lipid metabolism and the development of kidney stones and suggest a clear direction for future research.