Understanding kidney function by comparing serum and urine proteomes

Abstract

Human serum and urine proteomes which represent, respectively, the main protein compositions of input and output of the kidney, have been profiled in a number of studies. Comparing these two proteomes may help us understand the kidney functions in a way which was unavailable until the recent advances in proteomics methodology. In this study, we compared 3020 proteins in serum proteome and 1543 in urine identified with high confidence. There are 288 proteins common in both serum and urine; 2732 proteins were identified exclusively in serum; and 1255 proteins exclusively in urine. The proteins in each of the three groups were categorized based on their biochemical and cellular properties. The more detailed kidney functions were subsequently described. Since the data were generated by different groups of researchers with different methods, the results and conclusions here should be used with caution. More and better controlled comparative experiments are required for systematic study of kidney functions in the future. Because of its characteristic functions with distinct input and output flows, we believe kidney will be the first organ whose functions will be further elucidated by proteomic methods.