Background: Irritable bowel syndrome (IBS) is a pathologic condition characterized by changes in gut microbiome composition, low-grade inflammation, and disruption of intestinal wall permeability. The interaction between the gut microbiome and the disease manifestation remains unclear. The changing of tight junction proteins and cytokines expression throughout the gastrointestinal tract in IBS patients has not been studied yet. Aim of the study: To assess the changes of gut microbiome composition, tight junction proteins, and cytokines expression of intestinal mucosa from the duodenum to the distal part of the colon in IBS patients and healthy volunteers. Methods: In 31 IBS patients (16 patients with IBS-D; 15 patients with IBS-C) and 10 healthy volunteers the expression of CLD-2, CLD-3, CLD-5, IL-2, IL-10, and TNF-α in mucosal biopsy specimens was determined by morphological and immune-histochemical methods. The qualitative and quantitative composition of the intestinal microbiota was assessed based on 16S rRNA gene sequencing in both groups of patients. Results: The expression of IL-2 and TNF-α was significantly increased in IBS patients compared with the controls (p<0.001), with a gradual increase from the duodenum to the sigmoid colon. The expression of IL-10, CLD-3, and CLD-5 in mucosal biopsy specimens of these patients was lower than in the control group (p<0.001). Increased ratios of Bacteroidetes and decreased ratios of Firmicutes were noted in IBS patients compared to healthy volunteers (p<0.05). Conclusion: IBS patients have impaired gut permeability and persisting low-grade inflammation throughout the gastrointestinal tract. Changes in the gut microbiota may support or exacerbate these changes.

The etiology of intervertebral disc degeneration (IVDD) is complex and multifactorial, and it is still not fully understood. A better understanding of the pathogenesis of IVDD will help to improve treatment regimens and avoid unnecessary surgical aggression. In order to summarize recent research data on IVDD pathogenesis, including genetic and immune factors, a literature review was conducted. The pathogenesis of IVDD is a complex multifactorial process without an evident starting point. There are extensive data on the role of the different genetic factors affecting the course of the disease, such as mutations in structural proteins and enzymes involved in the immune response. However, these factors alone are not sufficient for the development of the disease. Nevertheless, like mechanical damage, they can also be considered risk factors for IVDD. In conclusion, currently, there is no consensus on a single concept for the pathogenesis of IVDD. We consider the intervertebral disc autoimmune damage hypothesis to be the most promising hypothesis for clinicians, because it can be extrapolated to all populations and does not counteract other factors. The genetic factors currently known do not allow for building effective predictive models; however, they can be used to stratify the risks of individual populations.

Hemoglobin is the main protein of red blood cells that provides oxygen transport to all cells of the human body. The ability of hemoglobin to bind the main low-molecular-weight thiol of the cell glutathione, both covalently and noncovalently, is not only an important part of the antioxidant protection of red blood cells, but also affects its affinity for oxygen in both cases. In this study, the properties of oxyhemoglobin in complex with reduced glutathione (GSH) and properties of glutathionylated hemoglobin bound to glutathione via an SS bond were characterized. For this purpose, the methods of circular dichroism, Raman spectroscopy, infrared spectroscopy, tryptophan fluorescence, differential scanning fluorimetry, and molecular modeling were used. It was found that the glutathionylation of oxyhemoglobin caused changes in the secondary structure of the protein, reducing the alpha helicity, but did not affect the heme environment, tryptophan fluorescence, and the thermostability of the protein. In the noncovalent complex of oxyhemoglobin with reduced glutathione, the secondary structure of hemoglobin remained almost unchanged; however, changes in the heme environment and the microenvironment of tryptophans, as well as a decrease in the protein’s thermal stability, were observed. Thus, the formation of a noncovalent complex of hemoglobin with glutathione makes a more significant effect on the tertiary and quaternary structure of hemoglobin than glutathionylation, which mainly affects the secondary structure of the protein. The obtained data are important for understanding the functioning of glutathionylated hemoglobin, which is a marker of oxidative stress, and hemoglobin in complex with GSH, which appears to deposit GSH and release it during deoxygenation to increase the antioxidant protection of cells.

Background: Irritable bowel syndrome (IBS) affects 9,2% of the global population and places a considerable burden on healthcare systems. Most medications for treating IBS, including spasmolytics, laxatives, and antidiarrheals, have low efficacy. Effective and safe therapeutic treatments have yet to be developed for IBS.Purpose: This study assessed the efficacy and safety of a food supplement containing standardized menthol, limonene, and gingerol in human participants with IBS or IBS/functional dyspepsia (FD).Design: A double-blind, randomized, placebo-controlled trial.Methods: We randomly assigned 56 patients with IBS or IBS/FD to an intervention group (Group 1) or control group (Group 2) that were given supplement or placebo, respectively, in addition to the standard treatment regimen for 30 d. Three outpatient visits were conducted during the study. Symptom severity was measured at each visit using a 7×7 questionnaire. Qualitative and quantitative composition of the intestinal microbiota were assessed at visits 1 and 3 based on 16S rRNA gene sequencing.Results: At visit 1 (before treatment), the median total 7×7 questionnaire score was in the moderately ill range for both groups, with no difference between the groups (p= 0.1). At visit 2, the total 7×7 score decreased to mildly ill, with no difference between the groups (p= 0.4). At visit 3, the total score for group 1 indicated borderline illness and for group 2 remained indicated mild illness (p= 0.009). Even though we observed some variations in gut microbiota between the groups, we did not find any statistically significant changes.Conclusion: The food supplement with standardized menthol, limonene, and gingerol content increased the efficacy of standard therapy in IBS and FD patients. The use of the supplement did not cause any obvious side effects.Registration: ClinicalTrials.gov Identifier:NCT04484467

Cardiotonic steroids (CTSs) are specific inhibitors of Na,K-ATPase (NKA). They induce diverse physiological effects and were investigated as potential drugs in heart diseases, hypertension, neuroinflammation, antiviral and cancer therapy. Here, we compared the inhibition mode and binding of CTSs, such as ouabain, digoxin and marinobufagenin to NKA from pig and rat kidneys, containing CTSs-sensitive (α1S) and - r esistant (α1R) α1-subunit, respectively. Marinobufagenin in contrast to ouabain and digoxin interacted with α1S-NKA reversibly, and its binding constant was reduced due to the decrease in the deepening in the CTSs-binding site and a lower number of contacts between the site and the inhibitor. The formation of a hydrogen bond between Arg111 and Asp122 in α1R-NKA induced the reduction in CTSs’ steroid core deepening that led to the reversible inhibition of α1R-NKA by ouabain and digoxin and the absence of marinobufagenin’s effect on α1R-NKA activity. Our results elucidate that the difference in signaling, and cytotoxic effects of CTSs may be due to the distinction in the deepening of CTSs into the binding side that, in turn, is a result of a bent-in inhibitor steroid core (marinobufagenin in α1S-NKA) or the change of the width of CTSs-binding cavity (all CTSs in α1R-NKA).