Comprehensive lipidomic profiling in serum and multiple tissues from a mouse model of diabetes

Introduction: Diabetes mellitus is a serious metabolic disorder causing multiple organ damage in human. However, the lipidomic profiles in different organs and their associations are rarely studied in either diabetic patients or animals. Objectives: To evaluate and compare the characteristics of lipid species in serum and multiple tissues in a diabetic mouse model. Methods: Semi-quantitative profiling analyses of intact and oxidized lipids were performed in serum and multiple tissues from a diabetic mouse model fed a high fat diet and treated with streptozotocin by using LC/HRMS and MS/MS. The total content of each lipid class, and the tissue-specific lipid species in all tissue samples were determined and compared by multivariate analyses. Results: The diabetic mouse model displayed characteristic differences in serum and multiple organs: the brain and heart showed the largest reduction in cardiolipin, while the kidney had more alterations in triacylglycerol. Interestingly, the lipidomic differences also existed between different regions of the same organ: cardiolipin species with highly polyunsaturated fatty acyls decreased only in atrium but not in ventricle, while renal cortex showed longer fatty acyl chains for both increased and decreased triacylglycerol species than renal medulla. Importantly, diabetes caused an accumulation of lipid hydroperoxides, suggesting that oxidative stress was induced in all organs except for the brain during the development of diabetes. Conclusions: These findings provided novel insight into the organ-specific relationship between diabetes and lipid metabolism, which might be useful for evaluating not only diabetic tissue injury but also the effectiveness of diabetic treatments.