Biochemical Markers in the Prediction of Pregnancy Outcome in Gestational Diabetes Mellitus.

Background and Objectives: Gestational diabetes mellitus (GDM) may impact both maternal and fetal/neonatal health. The identification of prognostic indicators for GDM may improve risk assessment and selection of patient for intensive monitoring. The aim of this study was to find potential predictors of adverse pregnancy outcome in GDM and normoglycemic patients by comparing the levels of different biochemical parameters and the values of blood cell count (BCC) between GDM and normoglycemic patients and between patients with adverse and good outcome. Materials and Methods: Prospective clinical study included 49 patients with GDM (study group) and 44 healthy pregnant women (control group) who underwent oral glucose tolerance test (OGTT) at gestational age of 24-28 weeks. At the time of OGTT peripheral blood was taken for the determination of glucose levels, insulin, glycated hemoglobin, lipid status, homeostatic model assessment, BCC, iron and zinc metabolism, liver function, kidney function and inflammatory status. Each group was divided into two subgroups-normal and poor pregnancy outcome. Results: Higher RBC, hemoglobin concentration, hematocrit value, fasting glucose, uric acid and fibrinogen were found in GDM patients compared to control group. In GDM patients with poor pregnancy outcome values of fibrinogen, ALT, sedimentation rate, granulocyte and total leukocyte counts were elevated, while the serum level of zinc was significantly lower. Higher level of fibrinogen was found in normoglycemic patients with adverse pregnancy outcomes. ROC curve was constructed in order to assess fibrinogen's biomarker potential. The established AUC value for diagnostic ROC was 0.816 (p < 0.001, 95% CI 0.691-0.941), while the AUC value for assessing fibrinogen's potential to predict poor pregnancy outcome in GDM was 0.751 (p = 0.0096, 95% CI 0.561-0.941). Conclusions: The results of our study demonstrated that the best prognostic potential in GDM showed inflammation related parameters, identifying fibrinogen as a parameter with both diagnostic and prognostic ability.

Diagnostic properties of miR-146a-5p from liquid biopsies in prostate cancer: A meta-analysis.

BACKGROUND: Several studies on biomarker properties of microRNAs from liquid biopsy in prostate cancer (PCa) identified miR-146a-5p as a potential novel diagnostic marker. However, other studies with the same or similar topic failed to confirm the supposed discriminatory ability of miR-146a-5p, for which reason we aimed at elucidating the potential biomarker role of circulatory/urinary miR-146a-5p in PCa by conducting a qualitative and quantitative data synthesis. METHODS: Eligible articles were identified by searching PubMed, Scopus and Web of Science databases. Open MetaAnalyst software was used for pooling data on sensitivity, specificity, likelihood ratio and diagnostic odds ratio (OR) of miR-146a-5p. RESULTS: A total of 15 articles were eligible for qualitative data synthesis, while the results from 13 studies with 2080 participants were included in the meta-analysis. The established between-study heterogeneity was high, while the expression of hsa-miR-146a was associated with a diagnostic OR of 3.544 (P < 0.001; 95 %CI 2.186-5.747). Pooled sensitivity was found to be lower than 70 % (0.655, 95 %CI 0.573-0.729, P < 0.001), while the obtained value for specificity was 65 % (95 %CI 0.583-0.709, P < 0.001). Segregating studies according to ethnicity, sample type or the type of controls did not result in significantly higher sensitivity and specificity in subgroups, compared to the overall pooled data. CONCLUSIONS: The resulting pooled sensitivity, specificity and diagnostic OR do not qualify miR-146a-5p for a reliable diagnostic biomarker of PCa.

Glycosylation and Characterization of Human Transferrin in an End-Stage Kidney Disease.

Chronic kidney disease (CKD) is a global health concern affecting approximately one billion individuals worldwide. End-stage kidney disease (ESKD), the most severe form of CKD, is often accompanied by anemia. Peritoneal dialysis (PD), a common treatment for ESKD, utilizes the peritoneum for solute transfer but is associated with complications including protein loss, including transferrin (Tf) a key protein involved in iron transport. This study investigated Tf characteristics in ESKD patients compared to healthy individuals using lectin microarray, spectroscopic techniques and immunocytochemical analysis to assess Tf interaction with transferrin receptors (TfRs). ESKD patients exhibited altered Tf glycosylation patterns, evidenced by significant changes in lectin reactivity compared to healthy controls. However, structural analyses revealed no significant differences in the Tf secondary or tertiary structures between the two groups. A functional analysis demonstrated comparable Tf-TfR interaction in both PD and healthy samples. Despite significant alterations in Tf glycosylation, structural integrity and Tf-TfR interaction remained preserved in PD patients. These findings suggest that while glycosylation changes may influence iron metabolism, they do not impair Tf function. The study highlights the importance of a glucose-free dialysis solutions in managing anemia exacerbation in PD patients with poorly controlled anemia, potentially offering a targeted therapeutic approach to improve patient outcomes.

Polyphenol-rich black currant and cornelian cherry juices ameliorate metabolic syndrome induced by a high-fat high-fructose diet in Wistar rats.

Diets high in fat and sugar lead to metabolic syndrome (MetS) and related chronic diseases. We investigated the effects of commercially available, cold-pressed polyphenol-rich black currant (BC) and cornelian cherry (CC) juices on the prevention of MetS in Wistar rats induced by a 10-weeks high-fat high-fructose (HFF) diet. Juice consumption, either BC or CC, with a HFF diet resulted in lower serum triglycerides compared to only the HFF consumption. Both juices also mitigated the effects of HFF on the liver, pancreas, and adipose tissue, by preserving liver and pancreas histomorphology and reducing visceral fat and adipocyte size. Furthermore, supplementation with both juices reduced glucagon and up-regulated insulin expression in the pancreas of the rats on the HFF diet, whereas the BC also showed improved glucose regulation. BC juice also reduced the expression of IL-6 and hepatic inflammation compared to the group only on HFF diet. Both juices, especially BC, could be a convenient solution for the prevention of MetS in humans.

The involvement of Akt, mTOR, and S6K in the in vivo effect of IGF-1 on the regulation of rat cardiac Na+/K+-ATPase.

BACKGROUND: We previously demonstrated that insulin-like growth factor-1 (IGF-1) regulates sodium/potassium adenosine triphosphatase (Na+/K+-ATPase) in vascular smooth muscle cells (VSMC) via phosphatidylinositol-3 kinase (PI3K). Taking into account that others' work show that IGF-1 activates the PI3K/protein kinase B (Akt) signaling pathway in many different cells, we here further questioned if the Akt/mammalian target of rapamycin (mTOR)/ribosomal protein p70 S6 kinase (S6K) pathway stimulates Na+/K+-ATPase, an essential protein for maintaining normal heart function. METHODS AND RESULTS: There were 14 adult male Wistar rats, half of whom received bolus injections of IGF-1 (50 µg/kg) for 24 h. We evaluated cardiac Na+/K+-ATPase expression, activity, and serum IGF-1 levels. Additionally, we examined the phosphorylated forms of the following proteins: insulin receptor substrate (IRS), phosphoinositide-dependent kinase-1 (PDK-1), Akt, mTOR, S6K, and α subunit of Na+/K+-ATPase. Additionally, the mRNA expression of the Na+/K+-ATPase α1 subunit was evaluated. Treatment with IGF-1 increases levels of serum IGF-1 and stimulates Na+/K+-ATPase activity, phosphorylation of α subunit of Na+/K+-ATPase on Ser23, and protein expression of α2 subunit. Furthermore, IGF-1 treatment increased phosphorylation of IRS-1 on Tyr1222, Akt on Ser473, PDK-1 on Ser241, mTOR on Ser2481 and Ser2448, and S6K on Thr421/Ser424. The concentration of IGF-1 in serum positively correlates with Na+/K+-ATPase activity and the phosphorylated form of mTOR (Ser2448), while Na+/K+-ATPase activity positively correlates with the phosphorylated form of IRS-1 (Tyr1222) and mTOR (Ser2448). CONCLUSION: These results indicate that the Akt/mTOR/S6K signalling pathway may be involved in the IGF-1 regulating cardiac Na+/K+-ATPase expression and activity.

Serum Glycome as a Diagnostic and Prognostic Factor in Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is a risk factor for both mother and fetus/neonate during and after the pregnancy. Inconsistent protocols and cumbersome screening procedures warrant the search for new and easily accessible biomarkers. We investigated a potential of serum N-glycome to differentiate between healthy pregnant women (n = 49) and women with GDM (n = 53) using a lectin-based microarray and studied the correlation between the obtained data and parameters of glucose and lipid metabolism. Four out of 15 lectins used were able to detect the differences between the control and GDM groups in fucosylation, terminal galactose/N-acetylglucosamine (Gal/GlcNAc), presence of Galα1,4Galß1,4Glc (Gb3 antigen), and terminal α2,3-sialylation with AUC values above 60%. An increase in the Gb3 antigen and α2,3-sialylation correlated positively with GDM, whereas the amount of fucosylated glycans correlated negatively with the content of terminal Gal/GlcNAc. The content of GlcNAc oligomers correlated with the highest number of blood analytes, indices, and demographic characteristics, but failed to discriminate between the groups. The presence of terminal Gal residues correlated positively with the glucose levels and negatively with the LDL levels in the non-GDM group only. The results suggest fucosylation, terminal galactosylation, and the presence of Gb3 antigen as prediction markers of GDM.

Association between nitric oxide synthase (NOS3) gene polymorphisms and diabetic nephropathy: An updated meta-analysis.

Polymorphisms located within NOS3 gene have been investigated as susceptibility variants for diabetic nephropathy (DN) in type 2 diabetes mellitus (T2DM) in a large number of studies. However, these previous articles yielded inconsistent results and we aimed at elucidating the impact of NOS3 variants on DN risk in T2DM by conducting an updated systematic data synthesis. A total of 36 studies (12,807 participants) were selected for qualitative data synthesis, while 33 records with 11,649 subjects were included in the meta-analysis. The pooled analysis demonstrated the association of minor alleles of rs2070744 and rs1799983 with an increased susceptibility to DN (P < 0.001 and P = 0.015 for allelic model, respectively). For both of these variants, a significant effect of subgrouping according to ethnicity was found. Rs869109213 displayed an association with DN susceptibility, with pooled effect measures indicating a predisposing effect of the minor allele a (Prec = 0.002, ORrec = 1.960, 95%CI 1.288-2.983; Paavs. bb = 0.001, ORaavs. bb = 2.014, 95%CI 1.316-3.083). These findings support the effects of NOS3 variants on the risk of developing DN in T2DM.

O-glycoprofiling of Serum Apolipoprotein C-III in Colorectal Cancer.

BACKGROUND: Aberrant glycosylation is a hallmark of cancer and thereby has an excellent potential for the discovery of novel biomarkers. Impairments in the glycan composition of lipoproteins impact their functional properties and can be associated with various diseases, including cancer. This research is still in its infancy; however, it can lead to the development of new diagnostic and disease stratification approaches as well as therapeutic strategies. Therefore, we aimed to evaluate anomalies in O-glycosylation of apolipoprotein C-III (apoC-III) in colorectal carcinoma (CRC) patients' sera, in comparison with sera from healthy individuals, and assess the disparities of O-glycoforms on apoC-III in CRC. METHODS: The choice of patients (n = 42) was based on the same tumor type (adenocarcinoma) and tumor size (T3), without or with inconsiderable lymph node infiltration. Patients with comorbidities were excluded from the study. The control healthy individuals (n = 40) were age- and sex-matched with patients. We used an approach based on the MALDI-TOF MS in linear positive ion mode, allowing simple analysis of O-glycosylation on intact apoC-III molecules in the serum samples directly, without the need for specific protein isolation. This approach enables relatively simple and high-throughput analysis. RESULTS: In CRC patients' sera samples, we observed significantly elevated apoC-III sialylation. Fully sialylated (disialylated) O-glycans had 1.26 times higher relative abundance in CRC samples compared to controls with a p-value of Mann-Whitney U test of 0.0021. CONCLUSIONS: We found altered O-glycosylation of apoC-III in the serum of CRC patients. However, it can be non-specific as it may be associated with another process such as ongoing inflammation. Therefore, to establish it as a potential novel non-invasive biomarker for CRC in suspected patients, further studies interrogating the changes in apoC-III O-glycosylation and the robustness of this biomarker need to be performed and evaluated.

Phycocyanobilin is a new binding partner of human alpha-2-macroglobulin that protects the protein against oxidative stress.

Under simulated physiological conditions, this study investigates the interaction between nutraceutical phycocyanobilin (PCB) and the universal anti-protease protein human alpha-2-macroglobulin (α2M). Extensive molecular docking analyses on multiple α2M conformations, spectroscopic techniques, and α2M activity assays were utilized to examine the complex formation. The results revealed that for every protein conformation, two high energy binding sites exist: the first, conformationally independent, at the interface region between two monomer chains and the second, conformationally dependent, in the pocket composed of amino acids from four distinct domains (TED, RBD, CUB, and MG2) of the single protein chain. Spectrofluorimetric measurements indicated a moderate affinity between α2M and PCB with a moderately high binding constant of 6.3 × 105 M-1 at 25 °C. The binding of PCB to α2M resulted in minor changes in the secondary structure content of α2M. Furthermore, PCB protected α2M from oxidation and preserved its anti-protease activity in the oxidative environment. These findings suggest that PCB binding could indirectly impact the body's response to oxidative stress by influencing α2M's role in controlling enzyme activity during the inflammatory process.Communicated by Ramaswamy H. Sarma.

Significance of 1,25-Dihydroxyvitamin D3 on Overall Mortality in Peritoneal Dialysis Patients with COVID-19.

In previous publications, we pointed out the importance of mannosylation of fibrinogen for the development of cardiovascular complications and fucosylation as a predictor of peritoneal membrane dysfunction in patients on peritoneal dialysis (PD). After a follow-up period of 30 months from the onset of the COVID-19 pandemic, we evaluated the significance of 1,25-dihydroxyvitamin D3 (calcitriol) therapy, primary disease, biochemical and hematologic analyzes, and previously performed glycan analysis by lectin-based microarray as predictors of mortality in this patient group. After univariate Cox regression analysis, diabetes mellitus (DM) and calcitriol therapy were found to be potential predictors of mortality. Additional multivariate Cox regression analysis confirmed that only DM was a predictor of mortality. Nevertheless, the use of calcitriol in therapy significantly reduced mortality in this patient group, as shown by the Kaplan-Meier survival curve. The presence of DM as a concomitant disease proved to be a strong predictor of fatal outcome in PD patients infected with SARS-CoV-2. This is the first study to indicate the importance and beneficial effect of calcitriol therapy on survival in PD patients with COVID-19 infection. In addition, this study points to the possibility that adverse thrombogenic events observed in PD patients during the pandemic may be caused by aberrant fibrinogen glycosylation.

Food Antioxidants and Their Interaction with Human Proteins.

Common to all biological systems and living organisms are molecular interactions, which may lead to specific physiological events. Most often, a cascade of events occurs, establishing an equilibrium between possibly competing and/or synergistic processes. Biochemical pathways that sustain life depend on multiple intrinsic and extrinsic factors contributing to aging and/or diseases. This article deals with food antioxidants and human proteins from the circulation, their interaction, their effect on the structure, properties, and function of antioxidant-bound proteins, and the possible impact of complex formation on antioxidants. An overview of studies examining interactions between individual antioxidant compounds and major blood proteins is presented with findings. Investigating antioxidant/protein interactions at the level of the human organism and determining antioxidant distribution between proteins and involvement in the particular physiological role is a very complex and challenging task. However, by knowing the role of a particular protein in certain pathology or aging, and the effect exerted by a particular antioxidant bound to it, it is possible to recommend specific food intake or resistance to it to improve the condition or slow down the process.

Prediction of Mortality in Patients on Peritoneal Dialysis Based on the Fibrinogen Mannosylation.

As we already reported, fibrinogen fucosylation emerged as a prognostic marker of peritoneal membrane function in end-stage renal disease (ESRD) patients on peritoneal dialysis. After a follow-up period of 18 months, we estimated the ability of employed lectins, as well as other biochemical parameters, to serve as mortality predictors in these patients. Following a univariate Cox regression analysis, ferritin, urea clearance, residual diuresis, hyperglycemia, and an increase in the signal intensity obtained with Galanthus nivalis lectin (GNL) emerged as potential mortality predictors, but additional multivariate Cox regression analysis pointed only to glucose concentration and GNL as mortality predictors. Higher signal intensity obtained with GNL in patients that died suggested the importance of paucimannosidic/highly mannosidic N-glycan structures on fibrinogen as factors that are related to unwanted cardiovascular events and all-cause mortality and can possibly be seen as a prediction tool. Altered glycan structures composed of mannose residues are expected to affect the reactivity of mannosylated glycoproteins with mannose-binding lectin and possibly the entire cascade of events linked to this lectin. Since patients with ESRD are prone to cardiovascular complications and the formation of atherosclerotic plaques, one can hypothesize that fibrinogen with increasingly exposed mannose residues may contribute to the unwanted events.

The association of human leucocyte antigen (HLA) alleles with COVID-19 severity: A systematic review and meta-analysis.

Due to their pivotal role in orchestrating the immune response, HLA loci were recognized as candidates for genetic association studies related to the severity of COVID-19. Since the findings on the effects of HLA alleles on the outcome of SARS-CoV-2 infection remain inconclusive, we aimed to elucidate the potential involvement of genetic variability within HLA loci in the molecular genetics of COVID-19 by classifying the articles according to different disease severity/outcomes and by conducting a systematic review with meta-analysis. Potentially eligible studies were identified by searching PubMed, Scopus and Web of Science literature databases. A total of 28 studies with 13,073 participants were included in qualitative synthesis, while the results of 19 studies with 10,551 SARS-CoV-2-positive participants were pooled in the meta-analysis. According to the results of quantitative data synthesis, association with COVID-19 severity or with the lethal outcome was determined for the following alleles and allele families: HLA-A*01, HLA-A*03, HLA-A*11, HLA-A*23, HLA-A*31, HLA-A*68, HLA-A*68:02, HLA-B*07:02, HLA-B*14, HLA-B*15, HLA-B*40:02, HLA-B*51:01, HLA-B*53, HLA-B*54, HLA-B*54:01, HLA-C*04, HLA-C*04:01, HLA-C*06, HLA-C*07:02, HLA-DRB1*11, HLA-DRB1*15, HLA-DQB1*03 and HLA-DQB1*06 (assuming either allelic or dominant genetic model). We conclude that alleles of HLA-A, -B, -C, -DRB1 and -DQB1 loci may represent potential biomarkers of COVID-19 severity and/or mortality, which needs to be confirmed in a larger set of studies.

Structural changes of proteins in liver cirrhosis and consequential changes in their function.

The liver is the site of synthesis of the majority of circulating proteins. Besides initial polypeptide synthesis, sophisticated machinery is involved in the further processing of proteins by removing parts of them and/or adding functional groups and small molecules tailoring the final molecule to suit its physiological purpose. Posttranslational modifications (PTMs) design a network of molecules with the common protein ancestor but with slightly or considerably varying activity/localization/purpose. PTMs can change under pathological conditions, giving rise to aberrant or overmodified proteins. Undesired changes in the structure of proteins most often accompany undesired changes in their function, such as reduced activity or the appearance of new effects. Proper protein processing is essential for the reactions in living beings and crucial for the overall quality control. Modifications that occur on proteins synthesized in the liver whose PTMs are cirrhosis-related are oxidation, nitration, glycosylation, acetylation, and ubiquitination. Some of them predominantly affect proteins that remain in liver cells, whereas others predominantly occur on proteins that leave the liver or originate from other tissues and perform their function in the circulation. Altered PTMs of certain proteins are potential candidates as biomarkers of liver-related diseases, including cirrhosis. This review will focus on PTMs on proteins whose structural changes in cirrhosis exert or are suspected to exert the most serious functional consequences.

The Insulin-like Growth Factor System and Colorectal Cancer.

Insulin-like growth factors (IGFs) are peptides which exert mitogenic, endocrine and cytokine activities. Together with their receptors, binding proteins and associated molecules, they participate in numerous pathophysiological processes, including cancer development. Colorectal cancer (CRC) is a disease with high incidence and mortality rates worldwide, whose etiology usually represents a combination of the environmental and genetic factors. IGFs are most often increased in CRC, enabling excessive autocrine/paracrine stimulation of the cell growth. Overexpression or increased activation/accessibility of IGF receptors is a coinciding step which transmits IGF-related signals. A number of molecules and biochemical mechanisms exert modulatory effects shaping the final outcome of the IGF-stimulated processes, frequently leading to neoplastic transformation in the case of irreparable disbalance. The IGF system and related molecules and pathways which participate in the development of CRC are the focus of this review.

The association of ACE1, ACE2, TMPRSS2, IFITM3 and VDR polymorphisms with COVID-19 severity: A systematic review and meta-analysis.

Genes involved in the regulation of viral recognition and its entry into a host cell have been identified as candidates for genetic association studies on COVID-19 severity. Published findings on the effects of polymorphisms within ACE1, ACE2, TMPRSS2, IFITM3 and VDR genes remained inconclusive, so we conducted a systematic review and meta-analysis in order to elucidate their potential involvement in the genetic basis underlying the severity of COVID-19 and/or an outcome of SARS-CoV-2 infection. Identification of potentially eligible studies was based on PubMed, Scopus and Web of Science database search. Relevant studies (n=29) with a total number of 8247 SARS-CoV-2-positive participants were included in qualitative synthesis, while results of 21 studies involving 5939 were pooled in meta-analysis. Minor allele I of rs1799752 located within ACE1 was identified as a protective variant against severe COVID-19, while its effect on mortality rate was opposite. Similarly, minor allele A of ACE2 polymorphism, rs2285666, was found to associate with a decreased risk of severe COVID-19 (P = 0.003, OR = 0.512, 95 % CI = 0.331-0.793). Statistical significance was also seen for the association between COVID-19 severity and rs12329760 located within TMPRSS2. Our results did not support the supposed association of rs12252 in IFITM3 and polymorphisms within VDR with disease severity. We conclude that genetic variants within ACE1, ACE2 and TMPRSS2 may be potential biomarkers of COVID-19 severity, which needs to be further confirmed in a larger set of studies.

Gestational Diabetes is Associated with an Increased Expression of miR-27a in Peripheral Blood Mononuclear Cells.

BACKGROUND: Dysregulation of microRNA-based mechanisms is associated with various human pathologies, including gestational diabetes mellitus (GDM), suggesting they may be  potential diagnostic and/or prognostic biomarkers of GDM. METHODS: The expression of miR-340-5p, miR-27a-3p and miR-222-3p in peripheral blood mononuclear cells (PBMCs) obtained from patients with GDM (n = 42) and healthy controls (n = 34) were evaluated, together with their correlation to the clinical parameters of participants and their newborns. Expression of the selected microRNAs was quantified by quantitative real-time polymerase chain reaction (qPCR), after reverse transcription with microRNA-specific stem-loop primers. RESULTS: The expression of miR-27a-3p was significantly higher in patients with GDM than in controls (p = 0.036), whereas no significant difference between groups was found for the other two tested microRNAs. The expression level of miR-27a-3p in GDM patients was found to negatively correlate with the number of erythrocytes, concentration of haemoglobin, haematocrit, and low- and high-density lipoprotein (LDL/HDL) ratio, and positively with the concentration of glycated haemoglobin (HbA1c). In the case of miR-222-3p, a negative correlation between its expression and the concentration of cholesterol, LDL and LDL/HDL ratio was found only in healthy pregnant women. The expression level of miR-340-5p negatively correlated with erythrocyte count, haemoglobin concentration and haematocrit in GDM patients, as well as with the concentration of cholesterol, LDL and LDL/HDL ratio in healthy women. CONCLUSIONS: The results obtained illustrate the potential of PBMC-derived microRNA miR-27a-3p to serve as a diagnostic biomarker of GDM. On the other hand, MiR-27a and miR-340 may help in assessing the metabolic status relevant for pregnancy.

Albumin at the intersection between antioxidant and pro-oxidant in patients on peritoneal dialysis.

Albumin (HSA) is a multifunctional protein and due to its free Cys34 thiol group, represents a main source of free thiols in the circulation. This property of HSA, combined with its ability to sequester redox active Cu(II) ions, makes HSA a dominant circulatory antioxidant. End stage kidney disease (ESRD) is a condition accompanied by elevated oxidative stress. The aim of the present study was to examine changes in the antioxidative capacity of HSA and Cu(II) binding affinity in patients on peritoneal dialysis (PD), and relate it to the Cys34 thiol group content and other structural changes of this molecule. HSA molecules are modified in ESRD patients subjected to PD, having significantly lower thiol group and bound Cu(II) content, reduced antioxidant capacity, an increased content of advanced glycation end-products and altered conformation. Also, Cu(II) binding capacity of HSA in these patients is impaired, since a significant portion of the high-affinity metal-binding site is unable to interact with Cu(II). Taking into account that the concentration of Cu(II) in the circulation of ESRD patients is much higher than in healthy persons and that Cu(II) binding capacity of HSA in these patients is significantly impaired, HSA may be considered as a novel circulatory pro-oxidant, thus exacerbating oxidative stress.

Major trace elements and their binding proteins in the early phase of Covid-19 infection.

Metal ions seem to play important roles in the pathogenesis of the novel coronavirus disease of 2019 (Covid-19) and are under investigation as potential prognostic markers and supplements in therapeutic procedures. The present study was aimed at assessing the relationship between the most abundant essential microelements (iron, zinc and copper) and their major binding proteins in the circulation in the early stage of infection. The concentration of zinc ions was measured to be higher in infected than in healthy persons, as well as ratios zinc/albumin and zinc/alpha-2-macroglobulin. Increased zinc levels could be attributed to cellular redistribution of zinc ions or to a use of zinc supplementation (zinc concentration was above the upper reference limit in one-third of infected individuals). Immunoblot analysis of protein molecular forms revealed that infected persons had greater amounts of proteinase-bound alpha-2-macroglobulin tetramer and albumin monomer than healthy individuals. The quantities of these forms were correlated with the concentration of zinc ions (r = 0.42 and 0.55, respectively) in healthy persons, but correlations were lost in infected individuals, most likely due to very high zinc concentrations in some participants which were not proportionally followed by changes in the distribution of protein species. Although we still have to wait for a firm confirmation of the involvement of zinc in beneficial defense mechanisms in patients with Covid-19, it seems that this ion may contribute to the existence of circulating protein forms which are the most optimal.

Lectin-Based Protein Microarray for the Glycan Analysis of Colorectal Cancer Biomarkers: The Insulin-Like Growth Factor System.

Lectin-based protein microarrays are used for glycoprofiling of various kinds of biological samples. Here we describe lectin-based microarray assay in the reverse-phase format where glycoprotein samples are spotted onto microarray slide and then are incubated with set of lectins. This configuration allows high-throughput screening of a large cohort of samples by a set of lectins without need of separation of glycans from glycoproteins. We applied the described method for glycan analysis of glycoprotein biomarkers of colorectal cancer associated with the insulin-like growth factor system.