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BACKGROUND. Primary focal segmental glomerulosclerosis (FSGS) and membranous nephropathy (MN) are diseases with primary podocyte damage with high proteinuria and nephrotic syndrome. While the mechanisms in primary MN are well understood, the pathogenesis of primary FSGS is still unknown, and therefore, the search for biomarkers that could expand ourunderstanding of its pathogenetic mechanisms. THE AIM: to determine the urine proteomic profile of patients with primary podocytopathies – FSGS in comparison with MN. PATIENTS AND METHODS. The study included 48 patients with a morphologically confirmed diagnosis of CGN occurring with nephrotic syndrome – 32 men and 16 women. In 18 patients, a decrease in glomerular filtration rate < 60 ml/min/1.73 m2 was observed. The histological diagnosis was confirmed by biopsy: 31 patients had FSGS, 17 patients with MN were included as a comparison group. The study of the urinary proteome was carried out by high performance liquid chromatography/mass spectrometry. RESULTS. In patients with FSGS, compared with the MN group, an increased content of 22 different proteins was noted, the most abundant were apolipoprotein A-I, hemopexin, vitronectin, pigment epithelial growth factor, components of the complement system (C3, C4b, factors B and H), retinol – and vitamin D-binding proteins, alpha-2-HS-glycoprotein, histidine-rich glycoprotein, plasma C1 protease inhibitor. In MN, increased urinary excretion of the complement component C2, fibrinogen alpha chain, osteopontin, and the SH3 domain-binding glutamic acid-rich-like protein 3, was detected. CONCLUSION. The proteomic profile of urine in FSGS, compared to MN, reflects the activation of variety of pathological processes – podocyte damage, involvement of parietal epithelial cells, tubulo-interstitial damage, accumulation of extracellular matrix, and complement activation process.

Metastasis is a serious and often life-threatening condition, representing the leading cause of death among women with breast cancer (BC). Although the current clinical classification of BC is well-established, the addition of minimally invasive laboratory tests based on peripheral blood biomarkers that reflect pathological changes in the body is of utmost importance. In the current study, the serum proteome and lipidome profiles for 50 BC patients with (25) and without (25) metastasis were studied. Targeted proteomic analysis for concertation measurements of 125 proteins in the serum was performed via liquid chromatography–multiple reaction monitoring mass spectrometry (LC–MRM MS) using the BAK 125 kit (MRM Proteomics Inc., Victoria, BC, Canada). Untargeted label-free lipidomic analysis was performed using liquid chromatography coupled to tandem mass-spectrometry (LC–MS/MS), in both positive and negative ion modes. Finally, 87 serum proteins and 295 lipids were quantified and showed a moderate correlation with tumor grade, histological and biological subtypes, and the number of lymph node metastases. Two highly accurate classifiers that enabled distinguishing between metastatic and non-metastatic BC were developed based on proteomic (accuracy 90%) and lipidomic (accuracy 80%) features. The best classifier (91% sensitivity, 89% specificity, AUC = 0.92) for BC metastasis diagnostics was based on logistic regression and the serum levels of 11 proteins: alpha-2-macroglobulin, coagulation factor XII, adiponectin, leucine-rich alpha-2-glycoprotein, alpha-2-HS-glycoprotein, Ig mu chain C region, apolipoprotein C-IV, carbonic anhydrase 1, apolipoprotein A-II, apolipoprotein C-II and alpha-1-acid glycoprotein 1.

Alzheimer's disease (AD) is the most common socially significant neurodegenerative pathology, which currently affects more than 30 million elderly people worldwide. Since the number of patients grows every year and may exceed 115 million by 2050, and due to the lack of effective therapies, early prediction of AD remains a global challenge, solution of which can contribute to the timely appointment of a preventive therapy in order to avoid irreversible changes in the brain. To date, clinical assays for the markers of amyloidosis in cerebrospinal fluid (CSF) have been developed, which, in conjunction with the brain MRI and PET studies, are used either to confirm the diagnosis based on obligate clinical criteria or to predict the risk of AD developing at the stage of mild cognitive impairment (MCI). However, the problem of predicting AD at the asymptomatic stage remains unresolved. In this regard, the search for new protein markers and studies of proteomic changes in CSF and blood plasma are of particular interest and may consequentially identify particular pathways involved in the pathogenesis of AD. Studies of specific proteomic changes in blood plasma deserve special attention and are of increasing interest due to the much less invasive method of sample collection as compared to CSF, which is important when choosing the object for large-scale screening. This review briefly summarizes the current knowledge on proteomic markers of AD and considers the prospects of developing reliable methods for early identification of AD risk factors based on the proteomic profile.

Bleomycin, which is widely used as an antitumor agent, possesses serious adverse effects such as pulmonary toxicity. Local nanoaerosol deposition for lung cancer treatment is a promising alternative to drug delivery to lung lesions. The aim of this work is to test the hypothesis that bleomycin nanoaerosol can be effectively used to treat multiple lung metastases. To obtain bleomycin nanoaerosol, an aerosol generator based on electrospray of a solution of a nonvolatile substance with gas-phase neutralization of charged aerosol particles was used. Lung metastases in murine Lewis lung carcinoma and B16 melanoma animal models were counted. The effect of inhaled bleomycin nanoparticles on the number and volume of metastases, as well as pulmonary side effects, was investigated. Using a mouse exposure chamber, the dose-dependent effect of inhaled bleomycin on tumor volume was evaluated in comparison with intraperitoneal administration. Bleomycin nanoaerosol reduced the volume of metastases and produced a higher antitumor effect at much lower doses. It has been established that long-term exposure to nanoaerosol with a low dose of bleomycin is capable of suppressing cancer cell growth. The treatment was well tolerated. In the lungs, minor changes were found in the form of focal-diffuse infiltration of the lung parenchyma.

The interest in the role of the gravitational factor during landing after long-term space flights (SF) leads to the search for various innovative approaches to assessing the compliance of external changes observed by clinicians. The results of special research methods such as Omics technologies that may reflect physiological responses to the conditions created during landing are of great interest. Our purpose is to compare the blood plasma proteome changes associated with the trauma and endothelial dysfunction processes prior to launch and on the day of landing, as well as the groups of cosmonauts with and without the secondary hemorrhagic purpura. In our study, the concentrations of 125 plasma proteins in 18 Russian cosmonauts, measured using targeted proteomic analysis based on liquid chromatography and tandem mass spectrometry were analyzed. The results reveal the trends of 12 proteins participating in the processes that trigger hemorrhagic purpura under the effect of re-entry g-forces. Exposure to intense g-forces and return to the gravity are the key factors for external manifestations of changes in the body systems induced by a long-term stay in space microgravity. Our results may be useful for further research to experts in gravitational physiology, aviation and space medicine.

The effect of the rapid redistribution of blood during head-up tilt tests in 21-day Dry Immersion suddenly became relevant in connection with the occurrence of mild hemorrhagic syndrome in the study participants. It became necessary to analyze the processes of occurrence of hemorrhagic syndrome as orthostatic and congestive purpura. The aim of this work was to study the features of the proteomic response of the human body to the rapid redistribution of blood during head-up tilt tests during 21-day immersion, which led to stagnant and orthostatic purpura. According to the results of examination of 10 healthy male volunteers aged 23–34 years after head-up tilt tests, pitting edema and local petechial hemorrhages in the soft tissues of the legs and feet were observed. Proteomic analysis of the samples was carried out by high performance liquid chromatography with tandem mass spectrometry. For bioinformatic analysis, the software packages Perseus, ANDSystem were used. From reliably different (p-value

Alzheimer’s disease (AD) is the leading cause of dementia among the elderly. Neuropathologically, AD is characterized by the deposition of a 39- to 42-amino acid long β-amyloid (Aβ) peptide in the form of senile plaques. Several post-translational modifications (PTMs) in the N-terminal domain have been shown to increase the aggregation and cytotoxicity of Aβ, and specific Aβ proteoforms (e.g., Aβ with isomerized D7 (isoD7-Aβ)) are abundant in the senile plaques of AD patients. Animal models are indispensable tools for the study of disease pathogenesis, as well as preclinical testing. In the presented work, the accumulation dynamics of Aβ proteoforms in the brain of one of the most widely used amyloid-based mouse models (the 5xFAD line) was monitored. Mass spectrometry (MS) approaches, based on ion mobility separation and the characteristic fragment ion formation, were applied. The results indicated a gradual increase in the Aβ fraction of isoD7-Aβ, starting from approximately 8% at 7 months to approximately 30% by 23 months of age. Other specific PTMs, in particular, pyroglutamylation, deamidation, and oxidation, as well as phosphorylation, were also monitored. The results for mice of different ages demonstrated that the accumulation of Aβ proteoforms correlate with the formation of Aβ deposits. Although the mouse model cannot be a complete analogue of the processes occurring in the human brain in AD, and several of the observed parameters differ significantly from human values supposedly due to the limited lifespan of the model animals, this dynamic study provides evidence on at least one of the possible mechanisms that can trigger amyloidosis in AD, i.e., the hypothesis on the relationship between the accumulation of isoD7-Aβ and the progression of AD-like pathology.

Fibrinogen (FG) is a protein that plays a key role in the hemostasis system and is most susceptible to oxidative modification compared to other plasma proteins. FG undergoes post-translational modifications that can potentially disrupt its structure and function.For the first time, using high resolution mass spectrometry (HPLC/MS/MS), the consequences of hypochlorite (HOCl)- induced FG oxidation were studied, and a list of FG amino acid residue oxidatively modifications. Samples of nonoxidized and treated with 50 μM HOCL fibrinogen were analyzed by mass spectrometry and it was found that many amino acid residues localized in all three polypeptide chains and the main structural elements of fibrinogen, with the exception of the E region, are involved in oxidation.Thus, the amino acid residues localized in the E region, which are involved in thrombin binding, were not subject to oxidative modification, which indicates the preservation of the thrombin-binding sites of the fibrinogen molecule during oxidation. The αС region contains the largest number of oxidizing sites, which confirms the hypothesis that this region can serve as a trap for reactive oxygen species (ROS) molecules.

Oxidative damage to main cell components (DNA, lipids, and proteins) in the human body during a spaceflight (SF) is more intense than in normal conditions because of the imbalance between production and elimination of free radicals and reactive oxygen species. Proteomics methods were used to estimate the frequency of oxidative posttranslational modifications (PTMs) in blood plasma proteins from Russian participants in semi-annual flights to the ISS. The influence of oxidative PTMs detectable after a SF on functional features was considered for the protein groups that are involved in metabolism of the extracellular matrix (ECM), lipid metabolism, immune functions, and control of inflammation according to a bioinformatics analysis. The protein components of apolipoproteins (APOA1, APOA2, APOA4, APOL1, and APOE) showed excessive oxidation in post-flight samples as compared with their pre-flight state, suggesting distortion of their vasculoprotective properties. A twofold or greater increase in the intensity of oxidative modification was observed for chains of both membrane and secretory immunoglobulins (Igs). The composition of oxidized fragments in chains (κ, γ1, γ2, γ4, and µ) of constant Ig domains indicated that the effector or signaling functions of Igs might be altered. Structural components of the ECM and ECM-associated compounds found in the extracellular fluid are a complex molecular hub that links immune functions, vascular competencies, inflammation control, protease–antiprotease balance, and hemostasis. The components of this system were considered in their close relationship.

Early recognition of the risk of Alzheimer’s disease (AD) onset is a global challenge that requires the development of reliable and affordable screening methods for wide-scale application. Proteomic studies of blood plasma are of particular relevance; however, the currently proposed differentiating markers are poorly consistent. The targeted quantitative multiple reaction monitoring (MRM) assay of the reported candidate biomarkers (CBs) can contribute to the creation of a consistent marker panel. An MRM-MS analysis of 149 nondepleted EDTA–plasma samples (MHRC, Russia) of patients with AD (n = 47), mild cognitive impairment (MCI, n = 36), vascular dementia (n = 8), frontotemporal dementia (n = 15), and an elderly control group (n = 43) was performed using the BAK 125 kit (MRM Proteomics Inc., Canada). Statistical analysis revealed a significant decrease in the levels of afamin, apolipoprotein E, biotinidase, and serum paraoxonase/arylesterase 1 associated with AD. Different training algorithms for machine learning were performed to identify the protein panels and build corresponding classifiers for the AD prognosis. Machine learning revealed 31 proteins that are important for AD differentiation and mostly include reported earlier CBs. The best-performing classifiers reached 80% accuracy, 79.4% sensitivity and 83.6% specificity and were able to assess the risk of developing AD over the next 3 years for patients with MCI. Overall, this study demonstrates the high potential of the MRM approach combined with machine learning to confirm the significance of previously identified CBs and to propose consistent protein marker panels.

Data normalization is an essential part of a large-scale untargeted mass spectrometry metabolomics analysis. Autoscaling, Pareto scaling, range scaling, and level scaling methods for liquid chromatography-mass spectrometry data processing were compared with the most common normalization methods, including quantile normalization, probabilistic quotient normalization, and variance stabilizing normalization. These methods were tested on eight datasets from various clinical studies. The efficiency of the data normalization was assessed by the distance between clusters corresponding to batches and the distance between clusters corresponding to clinical groups in the space of principal components, as well as by the number of features with a pairwise statistically significant difference between the batches and the number of features with a pairwise statistically significant difference between clinical groups. Autoscaling demonstrated the most effective reduction in interbatch variation and can be preferable to probabilistic quotient or quantile normalization in liquid chromatography-mass spectrometry data.

The kinetics of interaction between glutathione (GSH) and unsaturated phenol resveratrol (RVT) in deionized water in the presence of hydrogen peroxide (H2O2) is studied. At a physiological concentration (0.1–10 mM), GSH containing two carboxyl groups forms acidic solutions (pH of 3–4); the GSH molecules are associated into dimers. Under these conditions, GSH is quite slowly oxidized by atmospheric oxygen, and the reaction between GSH and H2O2 is accompanied by the formation of radicals. The thiyl radical initiation rate (Wi) is a few fractions of a percent of the GSH consumption rate; however, it is sufficient to initiate a thiol–ene chain reaction between GSH and RVT. Using the experimental data on the kinetics and the product composition and the published data on reactions of GSH with H2O2 and thiyl radicals, a kinetic model of the complex interaction between GSH and RVT in the presence of H2O2 in an aqueous medium at 37°C is proposed. The model includes 19 quasi-elementary reactions with respective rate constants, in particular, the formation of intermediate GSH–H2O2 and GSH–GSH complexes, the formation of radicals, and their subsequent transformations into final products in reactions with RVT and GSH. A computer simulation based on the developed model adequately describes the features of the process kinetics in a wide reactant concentration range.

Glomerulopathies with nephrotic syndrome that are resistant to therapy often progress to end-stage chronic kidney disease (CKD) and require timely and accurate diagnosis. Targeted quantitative urine proteome analysis by mass spectrometry (MS) with multiple-reaction monitoring (MRM) is a promising tool for early CKD diagnostics that could replace the invasive biopsy procedure. However, there are few studies regarding the development of highly multiplexed MRM assays for urine proteome analysis, and the two MRM assays for urine proteomics described so far demonstrate very low consistency. Thus, the further development of targeted urine proteome assays for CKD is actual task. Herein, a BAK270 MRM assay previously validated for blood plasma protein analysis was adapted for urine-targeted proteomics. Because proteinuria associated with renal impairment is usually associated with an increased diversity of plasma proteins being present in urine, the use of this panel was appropriate. Another advantage of the BAK270 MRM assay is that it includes 35 potential CKD markers described previously. Targeted LC-MRM MS analysis was performed for 69 urine samples from 46 CKD patients and 23 healthy controls, revealing 138 proteins that were found in ≥2/3 of the samples from at least one of the groups. The results obtained confirm 31 previously proposed CKD markers. Combination of MRM analysis with machine learning for data processing was performed. As a result, a highly accurate classifier was developed (AUC = 0.99) that enables distinguishing between mild and severe glomerulopathies based on the assessment of only three urine proteins (GPX3, PLMN, and A1AT or SHBG).

The proteome of human umbilical vein endothelial cells (HUVEC) cultured under static conditions and simulated microgravity (sμG) using Random Positioning Machine (RPM) for 24 h was studied by chromatography-mass spectrometry. It was revealed that the percentage of ribosomal proteins and proteins involved in intercellular adhesion, regulation of actin cytoskeleton, various pathways of cell signaling mediated by G-proteins, apoptosis and ubiquitin-dependent protein catabolism increased under sμG. At the same time the number of proteins associated with cell growth reduced. A significant increase in the peak intensities of proteins associated with maintaining the cytoskeleton and stress fibers (myristoylated alanine-rich C-kinase substrate, filamin-A, alpha-actinin-1 and myosin light polypeptide 6) and proteins involved in response to unfolded protein (serpin H1, 78 kDa glucose-regulated protein, transitional endoplasmic reticulum ATPase) was shown. At the same time, a significant decrease in the peak intensity of cofilin 1, which is capable of breaking actin filaments, was revealed. Thus, the most pronounced effect of microgravity is on the proteins associated with the actin cytoskeleton, as well as on adhesion proteins, whose properties also depend on the structure of the cytoskeleton. At the same time, the number of proteins which prevent improper protein folding increases, and the translation apparatus is rearranged under sμG.

This review covers the results of the application of mass spectrometric (MS) techniques to study the diversity of beta-amyloid (Aβ) peptides in human samples. Since Aβ is an important hallmark of Alzheimer's disease (AD), which is a socially significant neurodegenerative disorder of the elderly worldwide, analysis of its endogenous variations is of particular importance for elucidating the pathogenesis of AD, predicting increased risks of the disease onset, and developing effective therapy. MS approaches have no alternative for the study of complex samples, including a wide variety of Aβ proteoforms, differing in length and modifications. Approaches based on matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography with electrospray ionization tandem MS are most common in Aβ studies. However, Aβ forms with isomerized and/or racemized Asp and Ser residues require the use of special methods for separation and extra sensitive and selective methods for detection. Overall, this review summarizes current knowledge of Aβ species found in human brain, cerebrospinal fluid, and blood plasma; focuses on application of different MS approaches for Aβ studies; and considers the potential of MS techniques for further studies of Aβ-peptides.

The damage to blood coagulation factor XIII (FXIII) at different stages of its enzymatic activation under the action of various physiological amounts of hypochlorite ion was studied. The results obtained by HPLC-MS/MS, SDS-PAGE, and colorimetry showed that, during the conversion of FXIII to FXIIIa, the vulnerability of FXIII to hypochlorite-induced oxidation increased. FXIII oxidized with 150 μM hypochlorite completely retained its enzymatic activity inherent to the intact protein, whereas FXIIIa treated with 50 μM hypochlorite showed sharply reduced enzymatic activity. It was shown that a number of methionine and cysteine residues on the catalytic subunit can perform antioxidant function; additionally, the regulatory subunits of FXIII-B contribute to the antioxidant protection of the catalytic center of the FXIII-A subunit, which, together with the tight packing of the tetrameric structure of the FXIII proenzyme, are the three factors that provide high protein resistance to the oxidizing agent.

The balance of production and elimination of free radicals and reactive oxygen species is disturbed in the human body during a space flight. Oxidative stress is a common pathogenetic link in the violation of the functions and structure of various body tissues. The main cellular components, such as DNA, lipids, and proteins, undergo oxidative damage. In this study, proteomic methods were used to analyze the frequency of detection of oxidative post-translational modifications of blood plasma proteins obtained from Russian participants in International Space Station (ISS) flights. The effect of the oxidative modification detected after space flight on the functional features of protein groups that regulate the hemostasis and complement activation cascade is examined. According to published data, the increase in oxidative post-translational modifications of proteins in the hemostasis system affects not only the protein structure but also the fibrin formation, as well as its viscoelastic and biochemical properties. Oxygenation of proteins with oxidation-sensitive methionine residues, including apolipoprotein A-I, thrombomodulin, and von Willebrand factor, increases the risk of developing vascular diseases and thrombosis. Oxidized phospholipids are deposited in the vessel wall, potentiating atherosclerotic changes. It was shown that the oxidative modification of the key protein, clusterin, changed the regulation of the complement cascade, as well as the association of the immune system with the coagulation cascade.

The detection of viral RNA by polymerase chain reaction (PCR) is currently the main diagnostic tool for COVID-19 (Eurosurveillance2019, 25 ( (3), ), 1). The PCR-based test, however, shows limited sensitivity, especially in the early and late stages of disease development (Nature2020, 581, 465−46932235945; J. Formosan Med. Assoc.2020, 119 ( (6), ) 112332340768), and is relatively time-consuming. Fast and reliable complementary methods for detecting the viral infection would be of help in the current pandemic conditions. Mass spectrometry is one of such possibilities. We have developed a mass-spectrometry-based method for the detection of the SARS CoV-2 virus in nasopharynx epithelial swabs based on the detection of the viral nucleocapsid N protein. Our approach shows confident identification of the N protein in patient samples, even those with the lowest viral loads, and a much simpler preparation procedure. Our main protocol consists of virus inactivation by heating and the addition of isopropanol and tryptic digestion of the proteins sedimented from the swabs followed by MS analysis. A set of unique peptides, produced as a result of proteolysis of the nucleocapsid phosphoprotein of SARS-CoV-2, is detected. The obtained results can further be used to create fast parallel mass-spectrometric approaches for the detection of the virus in the nasopharyngeal mucosa, saliva, sputum and other physiological fluids.

Conducting a pilot study to assess the effect of thermal heliox on the state of the respiratory tract by studying of the exhaled breath condensate protein composition before the thermal heliox procedure, immediately after and after three hours of relaxation Materials and methods. A comparative study of the exhaled breath condensates (EBC) protein composition of five non-smoking healthy donors was carried out. The EBC was taken before the respiratory procedure, immediately after a 20-minute inhalation by mixture of He/O2 gases (70/30) heated to 70C and 3 hours later. The protein composition was determined by chromatography-mass spectrometric analysis after selective tryptic hydrolysis. The results were processed using the Mascot program and the UniProt database.After the heliox procedure, the volume of the collected condensate (11.5 ml) decreases by an average of 32% and is practically restored after three hours of relaxation. Most proteins were consistent for all samples, regardless of the thermal heliox procedure. These are keratins, several proteins of the immune system (immunoglobulins, compliment proteins), tubulin. In samples after thermal heliox, the appearance of small amounts of additional proteins is observed. These are proteins of muscle metabolism (actin and calmodulin), fibrinogen, traces of hemoglobin, apolipoprotein, type B creatine kinase. After three hours of relaxation, tubulin disappears in the EBC.Most exhaled proteins are the same before, after the procedure, and for three hours of relaxation. The results obtained demonstrate the relative safety of the use of high temperature heliox as a therapeutic agent.Цель. Проведение пилотного исследования по оценке влияния термического гелиокса на состояние респираторного тракта с помощью изучения белкового состава конденсата выдыхаемого воздуха до процедуры термического гелиокса, сразу после и спустя 3 ч релаксации. Материалы и методы. Проведено сравнительное исследование белкового состава конденсатов выдыхаемого воздуха (КВВ) 5 некурящих здоровых доноров. КВВ отбирали до дыхательной процедуры, сразу после 20-минутной ингаляции, нагретой до 70С смеси газов Не/О2 (70/30), и 3 ч спустя. Белковый состав определяли методом хромато-масс-спектрометрического анализа после селективного триптического гидролиза. Обработка результатов осуществлялась с использованием программы Mascot и базы данных UniProt. Результаты. После процедуры гелиокса объем собираемого конденсата (11,5 мл) падает в среднем на 32% и практически восстанавливается после 3-часовой релаксации. Основная часть белков постоянна для всех проб, независимо от процедуры термического гелиокса. Это кератины, несколько белков иммунной системы (иммуноглобулины, белки комплимента), тубулин. В пробах после термического гелиокса наблюдается появление в небольших количествах дополнительных белков. Это белки мышечного метаболизма (актины и кальмодулины), фибриноген, следы гемоглобина, аполипопротеина, креатинкиназы В типа. После 3-часовой релаксации в КВВ исчезает тубулин. Заключение. Большая часть выдыхаемых белков одинакова до, после процедуры и 3-часовой релаксации. Полученные результаты демонстрируют относительную безопасность применения высокотемпературного гелиокса как терапевтического средства.

Study of changes in the proteome of extracellular body fluids under conditions of simulated weightlessness of medium duration (21 days) remains relevant for clarifying the physiological mechanisms of homeostasis regulation and is important for gravitational physiology and medicine. Plasma samples of 8 healthy volunteers participating in head down bed rest (HDBR –6°) experiment were studied using semi-quantitative proteomics methods. Each volunteer participated both in the control session and in the session with physical training for negative changes prevention. By the end of HDBR, significant changes in the concentration of proteins involved in platelet degranulation, blood coagulation, fibrinolysis, proteolysis regulation, complement activation, and the immune response were detected in both sessions. The following changes in biochemical parameters of carbohydrate metabolism and regulation of circulating blood volume were shown: a significant increase in renin concentration and a tendency to an increase in aldosterone; an increase in fasting insulin concentration and a tendency to an increase in the insulin resistance index. Physical training did not have a significant effect on biochemical parameters, except for the representation of cholesterol fractions, un which a significant decrease in the concentration of high-density lipoprotein cholesterol observed in HDBR became statistically insignificant in session with physical training. However, the protein composition in blood plasma of volunteers in the prophylaxis session changed less compared to HDBR. Physical training resulted in increase in the concentration of proteins involved in the normalization of carbohydrate and lipid metabolism, such as a macrophage stimulating protein and phosphatidylinositol-glycan-specific phospholipase D, which indicates the effectiveness of preventive measures.

The plasma coagulation factor XIII (рFXIII) is a key protein of the blood coagulation systems, the main function of which consists of the enzymatic covalent stabilization of the polymeric structure of fibrin. The protein has a heterotetrameric structure consisting of two catalytic (FXIII-A2) and two regulatory (FXIII-В2) subunits. Using a high resolution mass spectrometry, hypochlorite-induced oxidation of рFXIII molecules and its enzymatic form (FXIIIa) is studied for the first time. It is demonstrated that sulfur and aromatic amino acid residues are the most vulnerable residues to oxidative attack. The mass spectrometry data indicate that oxidized amino acid residues are found in all structural elements of the FXIII-A catalytic subunit in the protein we are studying (except for the activation peptide), while a number of domains remain in native form in the FXIII-В regulatory subunit. When treated FXIIIa with hypochlorite, additional modification sites both in the FXIII- $${\text{A}}_{{\text{2}}}^{*}$$ and in the FXIII-В2 subunits are detected. The data obtained allowed us to postulate that in the process of converting the proenzyme into FXIIIa, new amino acid residues (previously inaccessible to oxidizers) migrate to the surface of the protein globule and become vulnerable targets for oxidizer molecules, while some of the initially surface-exposed amino acid residues move inside the protein, losing their ability to participate in the oxidative modifications. Electrophoresis of reduced samples of covalently cross-linked fibrin detected a decrease in transglutaminase activity of oxidized FXIIIa manifested in the inhibition of the reaction of the formation of γ–γ-dimers. The ability of the рFXIII molecule to resist the oxidative attack due to its antioxidant structural adaptation to the effect of reactive oxygen species is discussed.

Broad application of mass spectrometry in clinical practice was only possible with the development of the physicochemical fundamentals of the method. New ionization techniques and ion detection systems have not only enhance the variety of biomolecules in diagnostics, but also provided an opportunity to apply direct mass spectrometry methods to guide surgical interventions. Here we present a brief review of the latest achievements in mass spectrometry applications in oncological surgery and neurosurgery in particular. We describe our recent advance in this area and demonstrate that the combination of different mass spectrometric techniques improves the overall comprehensiveness of the analysis.

The purpose of this work was to reveal the intra- and inter-individual variability of the urine proteomic composition and of biochemical blood parameters in cosmonauts with different preflight autonomic status when they are back to Earth (on the 1st and 7th day after space flight). The objects of the study were 5-min samples of electrocardiogram (ECG) at rest and urine and venous blood samples, obtained in the same timeline from twelve male cosmonauts (age 46.5 ± 3.4 years), who performed space flights (SF) with duration 169–199 days onboard the Russian segment of the International Space Station (ISS). Two groups with different sympathetic-parasympathetic balance were identified (each consists of 6 cosmonauts) by the results of preflight heart rate variability (HRV) analysis. We have revealed in groups of cosmonauts with preflight predominance of sympathetic or parasympathetic tone the significant differences in the directionality of changes on days 1 and 7 after the SF as compared to the preflight values in three proteins (from total amount around 200): alpha-1 subunit of collagen type VI, Mucin 1, Cadherin-13. A set of biochemical parameters, unidirectionally changing with these proteins, was different in classified groups. Direct bilirubin, potassium and total calcium move unidirectionally with collagen, direct bilirubin, potassium – with mucin, and uric acid, ferrum, alpha-1, KFK, potassium - with cadherin in group with a sympathetic tone. Potassium, ferrum, alpha-1 move unidirectionally with collagen, amylase, KFK, AST, urea, inorganic phosphate, glucose, alkaline phosphatase, ionized calcium – with mucin, and total ferrum biding capacity, transferrin, glucose gamma globulin transferase - with cadherin in group with parasympathetic predominance. Probably, differences between groups in the concentration of these proteins and their different relationship with some biochemical parameters reflect different ways to achieve the same goal - adaptation to a complex of SF factors and re-adaptation after returning to Earth.

Urine chromatography–mass spectrometry and a heart rate variability (HRV) analysis were performed in 13 healthy males (age 28 ± 4 years, height 174 ± 1 cm, weight 67.9 ± 1.5 kg). Mathematical and bioinformatics analyses identified the proteins that are associated with the condition of the cardiovascular system and the autonomic regulation of the heart rate in the total protein aggregate. The set included serotransferrin, tyrosine-protein kinase receptor UFO, prostatic acid phosphatase, secreted and transmembrane protein 1, cell adhesion molecule 4, galectin-3-binding protein, immunoglobulin heavy constant alpha 1, matrix remodeling-associated protein 8, and biotinidase. Associations were for the first time studied for protein markers of the heart rate autonomic regulation. Proteomics data were used to describe the indicators of the heart rate physiological regulation in the urine proteome of healthy young males.

Changes in bacterial physiology caused by the combined action of the magnetic force and microgravity were studied in

The recent surge of COVID-19 hospitalizations severely challenges healthcare systems around the globe and demands for reliable tests predictive of disease severity and mortality. Using multiplexed targeted mass spectrometry assays on a robust triple quadrupole MS setup which is available in many clinical laboratories, we determined the precise concentrations of 100s of proteins and metabolites in plasma from hospitalized COVID-19 patients. We observed a clear distinction between COVID-19 patients and controls and, strikingly, a significant difference between survivors and non-survivors. With increasing length of hospitalization, the survivors’ samples showed a trend towards normal concentrations, indicating a potential sensitive readout of treatment success. Building a machine learning multi-omic model that considers the concentrations of ten proteins and five metabolites we could predict patient survival with 92% accuracy (AUC 0.97) at the day of hospitalization. Hence, our standardized assays represent a unique opportunity for the early stratification of hospitalized COVID-19 patients.

The study presents the results of evaluating the changes in the concentrations of blood plasma proteins associated with heart rate variability in cosmonauts who have completed space missions lasting about 6 months. The concentrations of 121 proteins were quantified in biological samples of the cosmonauts' blood plasma. The subgroups of proteins associated with the physiological processes of the heart rate variability autonomic regulation were identified using bioinformatic resources (Immunoglobulin heavy constant mu, Complement C1q subcomponent subunit C, Plasma serine protease inhibitor, Protein - 72 kDa type IV collagenase, Fibulin-1, Immunoglobulin lambda constant 3). The concentration of these proteins in the blood plasma before the flight, and the dynamics of concentration changes on the 1st and 7th days of the post-flight rehabilitation period differed in the groups of cosmonauts with a predominance of sympathetic or parasympathetic modulating autonomous influences. The dynamics of changes in the concentrations of the identified set of proteins reveal that in cosmonauts with a predominance of sympathetic modulating influences, the mechanisms of autonomic regulation are exposed to significant stress in the recovery period immediately after the completion of the space mission, compared with the cosmonauts with a predominance of parasympathetic modulating influences.

Chronic kidney disease (CKD) is a non-specific type of kidney disease that causes a gradual decline in kidney function (from months to years). CKD is a significant risk factor for death, cardiovascular disease, and end-stage renal disease. CKDs of different origins may have the same clinical and laboratory manifestations but different progression rates, which requires early diagnosis to determine. This review focuses on protein/peptide biomarkers of the leading causes of CKD: diabetic nephropathy, IgA nephropathy, lupus nephritis, focal segmental glomerulosclerosis, and membranous nephropathy. Mass spectrometry (MS) approaches provided the most information about urinary peptide and protein contents in different nephropathies. New analytical approaches allow urinary proteomic–peptide profiles to be used as early non-invasive diagnostic tools for specific morphological forms of kidney disease and may become a safe alternative to renal biopsy. MS studies of the key pathogenetic mechanisms of renal disease progression may also contribute to developing new approaches for targeted therapy.

A pathology diagnostic using molecular marker is a perspective direction of clinical medicine. Mass-spectrometry (MS) is a one of methods, which are used for obtaining information about molecular profiles. Selection of species, essential for classification “case/control is an important task for data processing. Pipeline of data processing has been proposed using MS data, obtained during analysis of tumor breast tissue samples and health breast tissue samples, with the aim of metastasis marker selection. As a result, selection of lipid markers that belong to classes, related to metastasis and proliferation processes, makes it possible to create high sensitivity diagnostic model, based on logistic regression. The proposed method is applicable for data processing, obtained by MS analysis of other “omics”: metabolome, proteome, glycome., Диагностика патологии по молекулярным маркерам является перспективным направлением клинической медицины, в котором масс-спектрометрия (МС) яслужит одним из методов, используемых для получения информации о молекулярных профилях. В контексте извлечения соединений, играющих ключевую роль для классификации патология/болезнь, важное значение имеет обработка полученных данных, часто включающих несколько сотен детектированных соединений. В данной работе предложен алгоритм обработки данных на примере данных МС, полученных при анализе опухолевой ткани и здоровой молочной железы, с целью выделения липидных маркеров метастазирования. В результате его реализации получен набор соединений, относящихся к классам липидов, связанных с процессами метастазирования и пролиферации, и позволяющих построить высокочувствительную диагностическую модель на основе логистической регрессии. Предложенный метод потенциально пригоден для обработки данных МС, полученных при анализе молекулярного профиля биоматериала другого базиса (метаболом, протеом, гликом).

Introduction Lung cancer remains the most prevalent cause of cancer mortality worldwide mainly due to insufficient availability of early screening methods for wide-scale application. Exhaled breath condensate (EBC) is currently considered as one of the promising targets for early screening and is particularly attractive due to its absolutely noninvasive collection and possibility for long-term frozen storage. EBC proteome analysis can provide valuable information about the (patho)physiological changes in the respiratory system and may help to identify in time a high risk of lung cancer. Mass spectrometry (MS) profiling of EBC proteome seems to have no alternative in obtaining the most extensive data and characteristic marker panels for screening. Areas covered This special report summarizes the data of several proteomic studies of EBC in normal and lung cancer (from 2012 to 2021, PubMed), focuses on the possible reasons for the significant discrepancy in the results, and discusses some aspects for special attention in further studies. Expert opinion The significant discrepancy in the results of various studies primarily highlights the need to create standardized protocols for the collection and preparation of EBC for proteomic analysis. The application of quantitative and targeted LC-MS/MS based approaches seems to be the most promising in further EBC proteomic studies.

The proteome of exhaled breath condensate was analyzed by mass spectrometry before, immediately after the thermoheliox procedure and after a 3 h relaxation. The major part of the proteome remained unchanged and there was no extensive cell destruction

Primary focal segmental glomerulosclerosis (FSGS), along with minimal change disease (MCD), are diseases with primary podocyte damage that are clinically manifested by the nephrotic syndrome. The pathogenesis of these podocytopathies is still unknown, and therefore, the search for biomarkers of these diseases is ongoing. Our aim was to determine of the proteomic profile of urine from patients with FSGS and MCD. Patients with a confirmed diagnosis of FSGS (n = 30) and MCD (n = 9) were recruited for the study. For a comprehensive assessment of the severity of FSGS a special index was introduced, which was calculated as follows: the first score was assigned depending on the level of eGFR, the second score—depending on the proteinuria level, the third score—resistance to steroid therapy. Patients with the sum of these scores of less than 3 were included in group 1, with 3 or more—in group 2. The urinary proteome was analyzed using liquid chromatography/mass spectrometry. The proteome profiles of patients with severe progressive FSGS from group 2, mild FSGS from group 1 and MCD were compared. Results of the label free analysis were validated using targeted LC-MS based on multiple reaction monitoring (MRM) with stable isotope labelled peptide standards (SIS) available for 47 of the 76 proteins identified as differentiating between at least one pair of groups. Quantitative MRM SIS validation measurements for these 47 proteins revealed 22 proteins with significant differences between at least one of the two group pairs and 14 proteins were validated for both comparisons. In addition, all of the 22 proteins validated by MRM SIS analysis showed the same direction of change as at the discovery stage with label-free LC-MS analysis, i.e., up or down regulation in MCD and FSGS1 against FSGS2. Patients from the FSGS group 2 showed a significantly different profile from both FSGS group 1 and MCD. Among the 47 significantly differentiating proteins, the most significant were apolipoprotein A-IV, hemopexin, vitronectin, gelsolin, components of the complement system (C4b, factors B and I), retinol- and vitamin D-binding proteins. Patients with mild form of FSGS and MCD showed lower levels of Cystatin C, gelsolin and complement factor I.