Formation of the urine proteome of healthy humans

Abstract

The review deals with modern ideas on the processes that determine the urine protein composition of healthy people. In the past decade, the development of highly sensitive mass-spectrometric methods of protein detection stimulated studies of the protein composition of various human body fluids, including urine. Nowadays, the methods of separating complex protein mixtures and identification of individual components of these mixtures provide an opportunity to detect a significant amount of proteins and peptides of different origins in human urine. Physiological variation of the urine protein composition determined by the methods of proteomics remains a poorly studied but very important problem. Under physiological conditions, there are many factors that influence the filtering of plasma proteins in the glomeruli and reabsorption in the proximal tubules of the nephron. These are hypoxia, oxidative stress, changes in the acid-base balance and blood pressure, the effects of the parathyroid hormone, angiotensin-II, and other substances that control water and electrolyte metabolism. It is demonstrated that, because of the close structural and functional relationships between reabsorption processes in the proximal tubules of the nephron, reabsorption and modulation of sodium, water, chloride, phosphate, and bicarbonate depend on changes in various parts of the process of protein reabsorption.