Changes of protein profile of human urine after long-term orbital flights.

We analyzed protein profile of urine samples obtained from 7 Russian cosmonauts (age 35-51 years), participants of space flights on the International Space Station lasting for 169-199 days. Gradient chromatography with linear increase of eluent proportion was carried out in a system consisting of an Agilent 1100 chromatograph (Agilent Technologies Inc.) and a hybrid mass-spectrometer LTQ-FT Ultra (Thermo). The obtained results help to understand changes in the human body induced by space flight factors.

[Reconstruction of associative protein networks connected with processes of sodium exchange' regulation and sodium deposition in healthy volunteers by urine proteome analysis].

The study was conducted during the experiment with 105-day isolation in experimental complex. In the present investigation we collected urine samples from 6 healthy volunteers. The physical activity, diurnal rhythm, temperature parameters and level of oxygen and carbon dioxide were controlled during the experiment. According to the program, food intake (electrolytes, water, calories, fat, carbohydrates, protein, vitamins, etc.) on each stage of experiment was normalized. All samples were analyzed using mass spectrometer of an ionic cyclotron resonance with transformation of Fure LTQ FT MS (Thermo) on the basis of the AMT-tags (accurate mass and time tags) approach. Among more than 20 000 we found out 690 proteotypical proteins and we identified about 600 urine proteins. For physiological interpretation of the proteome data we used computer systems ANDCell and ANDVisio. Clustering of proteins and application of these systems revealed proteins that are most closely associated with the regime of sodium intake, as well as build the network of their interactions.

[Variability of urine proteome of healthy persons during 105-daily isolation].

Human proteome is very plastic, it changes under the influence of various biological factors. It is of big interest to find out how specific factors of an environment, including a long-term isolation affect on urine proteome. The study was conducted during the experiment with 105-day isolation. In the present investigation we collected urine samples from 6 healthy volunteers (26-41 years old). The physical activity, daily rhythms and diet were controlled. Urine samples were fractionated on magnetic beads MB-HIC C8 (MB - hydrophobic-interaction chromatography) with ClinProt robot (Bruker Daltonics) prior to MALDI-TOF mass spectrometer analysis with Autoflex III TOF/TOF (Bruker Daltonics), working in a positive linear mode. 117 peaks have been obtained in each spectrum of urine. We have shown that even during isolation and under controlled conditions of life a high variability of urine proteome of healthy personas (36 protein MC-peaks in the urine, on average) are revealed.

[Direct proteome profiling of human blood serum in the experiment with 5-day dry immersion].

Purpose of the investigation was to determine changes in blood plasma proteome in healthy human subjects (n = 14, 19 to 26 y.o.) in an experiment with dry immersion (DI). Plasma samples were drawn 7 and 2 days before the exposure, on DI days 2, 3 and 5, and on days 1, 3, 7 and 15 after the experiment. Previous to direct MALDI-TOF mass-spectrometric profiling, serum samples were pre-fractionated and enriched with magnetic particles MB WCX (WCX--a weak cation exchanger) on ClinProt (Bruker Daltonics). In each spectrum, 175 MS-peaks were detected on average within the mass range from 1000 to 17,000 Da with the signal/noise ratio = 5. Student's criterion (p < 0.05) was used to define reliable differences between DI and baseline samples from 48 peaks (27.4 % of all the proteome profile peaks). On DI days 2 and 3, growth of peak areas was observed in fragments of complement system proteins C3 and C4, high-molecular kininogen and fibrinogen that can be attributed to organism adaptation to conditions of the experiment. Significant increases of the peak area of apolipoprotein CI (reduced form with segregated threonine and proline) and C4 enzymes of the complement system, and fibrinogen on the first day after the experiment can be related to changes in motor activities of the subjects.

[Renal functioning and human body liquids during 5-day dry immersion].

Renal function and body composition, including liquids, were investigated in 14 essentially healthy male subjects during simulation of some spaceflight effects by 5-d dry immersion (DI). Noninvasive measurement of water spaces of organism was performed with the methods of bio-impedance analysis (BIA). Increase of renal excretion of liquids and appearance of negative water balance were observed. BIA revealed reductions of total body and extracellular liquids and a decrease of circulating plasma volume. This means, that DI induced hypohydration of organism. In the post-DI period, the hydration status regained its baseline level fairly soon. Lean body mass slightly decreased; adipose mass, on the contrary, exceeded baseline values. Moreover, the experiment evidenced technical impossibility to obtain valid impedansimetry data in DI.