Preliminary study of the urinary proteome in Li and Han ethnic individuals from Hainan.

Biomarkers indicate changes associated with disease. Blood is relatively stable due to the homeostatic mechanisms of the body; however, urine accumulates metabolites from changes in the body, making it a better source for early biomarker discovery. The Li ethnic group is a unique minority ethnic group that has only lived on Hainan Island for approximately 5,000 years. Studies have shown that various specific genetic variations are different between the Li and Han ethnic groups. However, whether the urinary proteome between these two ethnic groups is significantly different remains unknown. In this study, differential urinary proteins were identified in the Li and Han ethnic groups using liquid chromatography tandem mass spectrometry (LC-MS/MS). In total, 1,555 urinary proteins were identified. Twenty-five of the urinary proteins were statistically significantly different, 16 of which have been previously reported to be biomarkers of many diseases, and that these significantly different proteins were caused by ethnic differences rather than random differences. Ethnic group differences may be an influencing factor in urine proteome studies and should be considered when human urine samples are used for biomarker discovery.