Factors of Interleukin-6 Signaling in COVID-19 Patients with Lung Damage of Varying Degrees: A Pilot Study.

Specific features of IL-6 signal transduction were studied in 89 patients with lung damage of varying degrees during the first COVID-19 pandemic wave. The levels of IL-6 signaling components (IL-6, sIL-6R, and sgp130) and highly sensitive C-reactive protein (hsCRP) were examined in patients with intact lungs (CT-0), mild (CT-1), moderate (CT-2), moderate to severe (CT-3), and severe (CT-4) lung damage. Seventy patients were re-examined 3-7 months after discharge from the hospital. The IL-6 and hsCRP levels increased several times with severing lung damage severity. In patients with CT-3, sIL6-R increased statistically significantly and remained high in CT-4 patients. sgp130 levels were lower in CT-1 and CT-2 patients and higher in CT-3 and CT-4 patients compared to CT-0 patients. We revealed a positive correlation between IL-6 and hsCRP levels in CT-1, CT-2, and CT-3 patients. In CT-3 patients, sIL-6R levels positively correlated with IL-6 concentration. The studied parameters decreased considerably in all patients 3-7 months after discharge. It can be suggested that IL-6 classic-signaling is predominant in CT-1 and CT-2, while trans-signaling prevails in CT-3. Disorders in regulatory mechanisms of IL-6 signaling occur in CT-4, which prevents physiological elimination of IL-6 hyperactivity. The results obtained are preliminary and require a broader study.

Role of sirtuins in epigenetic regulation and aging control.

Advances in modern healthcare in developed countries make it possible to extend the human lifespan, which is why maintaining active longevity is becoming increasingly important. After the sirtuin (SIRT) protein family was discovered, it started to be considered as a significant regulator of the physiological processes associated with aging. SIRT has deacetylase, deacylase, and ADP-ribosyltransferase activity and modifies a variety of protein substrates, including chromatin components and regulatory proteins. This multifactorial regulatory system affects many processes: cellular metabolism, mitochondrial functions, epigenetic regulation, DNA repair and more. As is expected, the activity of sirtuin proteins affects the manifestation of classic signs of aging in the body, such as cellular senescence, metabolic disorders, mitochondrial dysfunction, genomic instability, and the disruption of epigenetic regulation. Changes in the SIRT activity in human cells can also be considered a marker of aging and are involved in the genesis of various age-dependent disorders. Additionally, experimental data obtained in animal models, as well as data from population genomic studies, suggest a SIRT effect on life expectancy. At the same time, the diversity of sirtuin functions and biochemical substrates makes it extremely complicated to identify cause-and-effect relationships and the direct role of SIRT in controlling the functional state of the body. However, the SIRT influence on the epigenetic regulation of gene expression during the aging process and the development of disorders is one of the most important aspects of maintaining the homeostasis of organs and tissues. The presented review centers on the diversity of SIRT in humans and model animals. In addition to a brief description of the main SIRT enzymatic and biological activity, the review discusses its role in the epigenetic regulation of chromatin structure, including the context of the development of genome instability associated with aging. Studies on the functional connection between SIRT and longevity, as well as its effect on pathological processes associated with aging, such as chronic inflammation, fibrosis, and neuroinflammation, have been critically analyzed.

Interleukin 6 Signalling in Heart Failure With Preserved and Reduced Ejection Fraction.

AIM: Identification of interleukin-6 (IL-6) signaling pathways in patients with chronic heart failure (CHF). MATERIAL AND METHODS: The diversity of IL-6 effects is due to the presence of classical signaling and trans-signaling pathways. The study included 164 patients with CHF hospitalized for acute decompensated heart failure (ADHF), of which 129 had reduced left ventricular ejection fraction (HFrEF), and 35 had preserved ejection fraction (HFpEF). Blood concentrations of IL-6, soluble IL-6 receptor (sIL-6R), soluble transducer protein gp130 (sgp130), and high-sensitivity C-reactive protein (hsCRP) were measured. RESULTS: Patients with HFpEF had lower concentrations of IL-6 (6.15 [2.78, 10.65] pg/ml) and hsCRP (11.27 [5.84, 24.40] mg/ml) than patients with HFrEF (9.20 [4.70; 15.62] pg/ml and 17.23 [8.70; 34.51 mg/ml], respectively). In contrast, concentrations of rIL-6R were higher in HFpEF (59.06 [40.00; 75.85] ng/ml) than in HFrEF (49.15 [38.20; 64.89] ng/ml). Concentrations of sgp130 were not significantly different. In patients with HFrEF, positive correlations were found between the concentrations of IL-6 and hsCRP, IL-6 and rIL-6R, and IL-6 and sgp130, while in patients with HFpEF, there was a correlation only between IL-6 and hsCRP, which appeared stronger than in patients with HFrEF (r=0.698; p<0.001 and r=0.297; p<0.05, respectively). CONCLUSION: Classical IL-6 signaling and trans-signaling are expressed to different degrees in patients with HFrEF and HFpEF in ADHF. The results of the study supplement the existing knowledge about the pathogenesis of inflammation in CHF and may contribute to the development of new methods and approaches to the treatment of the disease.

Ratios between the Levels of IL-18, Free IL-18, and IL-1ß-Binding Protein Depending on the Severity and Outcome of COVID-19.

In 89 patients with COVID-19, the ratios between IL-18, free IL-18, and IL-18-binding protein (IL-18BP) were analyzed depending on severity and outcome of the disease. At admission to the hospital, the levels of IL-18 and free IL-18 were significantly higher than 3 months after discharge from the hospital, the levels IL-18BP of being almost the same. In patients with more severe lung injury (computed tomography data), the levels of IL-18 and free IL-18 were higher and IL-18BP levels were lower than in patients with mild and moderate COVID-19. Three months after discharge from the hospital, no differences between these parameters were found. In 9 patients who died in the hospital, free IL-18 levels were significantly higher and IL-18BP levels were lower than in survivors. Thus, high levels of bioactive free IL-18 in combination with low levels of IL-18BP can be indicative of severe inflammatory phase of COVID-19 and the risk of worse clinical outcomes.

Dynamics of Soluble Forms of the Immune Checkpoint Components PD-1/PD-L1/B7-H3, CD314/ULBP1, and HLA-G in Peripheral Blood of Melanoma Patients Receiving Blockers of Programmed Cell Death Protein PD-1.

The content of the soluble forms of immune checkpoint components sPD-1, sPD-L1 in blood serum, and sB7-H3, sCD314, sULBP1, sHLA-G in blood plasma of 30 melanoma patients receiving immunotherapy with anti-PD-1 antibodies (nivolumab, pembrolisumab) was measured before and in 4 and 8 weeks after the start of immunotherapy. The control group comprised 70 practically healthy donors. Standard immunoassay kits were used. In melanoma patients, the levels of sPD-L1 and sB7-H3 were significantly higher than in the control group (p<0001), sPD-1 level did not differ from the control, while sCD314 and sHLA-G levels were insignificantly decreased. During therapy, opposite changes in the levels of markers in individual patients were observed, and frequently after the initial increase (or decrease) after the first 4 weeks normalization did occur in the further 4 weeks. No statistically significant associations between the initial levels of markers and direction of their changes during treatment were found, but some trends indicating to the potential benefits from assessment of soluble forms of immune checkpoint proteins for evaluation and monitoring of the efficiency of the therapy with immune checkpoint blockers were revealed: significant decrease of sB7-H3 and sPD-1 levels in the course of treatment, higher initial sPD-1 level in patients with future progression than in those with stabilization or partial effect, and lower progression frequency in patients with increasing sPD-1 and sPD-L1 levels than in those with decreasing markers levels.

Dynamics of the Levels of Interleukin 6, Its Soluble Receptor, and Soluble Glycoprotein 130 in Patients with Chronic Heart Failure and Preserved or Reduced Ejection Fraction.

The features of IL-6 trans-signaling were studied in patients with heart failure with reduced (n=74) and preserved (n=31) ejection fraction (EF) during acute decompensation of HF (ADHF) and after 1 year. Patients with ADHF with reduced EF demonstrated higher levels of IL-6 and soluble glycoprotein 130 in comparison with those in patients with preserved EF: 10.18 (7.07; 16.14) pg/ml vs 6.35 (3.52; 11.00) pg/ml and 543.46 (455.37; 634.43) ng/ml vs 498.50 (408.16; 632.23) ng/ml, respectively. The levels of soluble IL-6 receptor little differed in these groups: 57.82 (47.55; 79.85) ng/ml vs 61.30 (44.97; 78.08) ng/ml. After 1 year, the levels of IL-6 in HF patients with reduced EF significantly decreased (5.36 (3.35; 8.35) pg/ml), while in patients with preserved EF, the decrease in this parameter was less pronounced (5.86 (4.05; 7.32) pg/ml), and the difference between groups disappeared. The levels of soluble glycoprotein 130 increased in both groups: 448.06 (357.74; 550.67) ng/ml vs 385.35 (344.29; 523.72) ng/ml. It should be noted that after 1 year (in stable patients), the levels of soluble IL-6 receptor increased in both groups: 65.75 (54.84; 75.39) ng/ml vs 70.81 (57.51; 82.25) ng/ml. Thus, despite the high levels of IL-6 in HF patients with reduced EF, the potential limiting IL-6 trans-signaling in these patients is higher than in patients with preserved EF.

[Transcription Factors of Direct Neuronal Reprogramming in Ontogenesis and ex vivo].

Direct reprogramming technology allows several specific types of cells, including specialized neurons, to be obtained from readily available autologous somatic cells. It presents unique opportunities for the development of personalized medicine, from in vitro models of hereditary and degenerative neurological diseases to novel neuroregenerative technologies. Over the past decade, a plethora of protocols for primary reprogramming has been published, yet reproducible generation of homogeneous populations of neuronally reprogrammed cells still remains a challenge. All existing protocols, however, use transcription factors that are involved in embryonic neurogenesis. This is presumably be the key issue for obtaining highly efficient and reproducible protocols for ex vivo neurogenesis. Analysis of the functional features of transcription factors in embryonic and adult neurogenesis may not only lead to the improvement of reprogramming protocols, but also, via cell marker analysis, can exactly determine the stage of neurogenesis that a particular protocol will reach. The purpose of this review is to characterize the general factors that play key roles in neurogenesis for the embryonic and adult periods, as well as in cellular reprogramming, and to assess correspondence of cell forms obtained as a result of cellular reprogramming to the ontogenetic series of the nervous system, from pluripotent stem cells to specialized neurons.

[Infections and inflammation in the development of stroke]. / Infektsii i vospalenie v razvitii insul'ta.

The review systematizes data on the role of infectious diseases and systemic inflammation in the pathogenesis of stroke. Various risk factors for stroke associated with pro-inflammatory reactions and their contribution to the pathogenesis of cerebrovascular pathology are analyzed. The interaction of systemic inflammation with hemostasis disturbances and clots formation, activation of autoreactive clones of cytotoxic lymphocytes, the progression of endothelial damage, and other processes is shown. Along with infection, these factors increase the risk of stroke. The key mechanisms of the pathogenesis from the development of acute or chronic inflammation to the preconditions of stroke are presented. The mechanisms of the acting of the infectious process as a trigger factor and/or medium-term or long-term risk factors of stroke are described. A separate section is devoted to the mechanisms of developing cerebrovascular diseases after COVID-19. Identifying an increased risk of stroke due to infection can be of great preventive value. Understanding of this risk by specialists followed by correction of drug therapy and rehabilitation measures can reduce the incidence of cerebrovascular complications in infectious patients.

Reduced Expression of Extracellular Matrix Proteins in the Heart and Kidneys of Rats with Endotoxemia under the Effect of Actinonin.

We studied modulation of the expression of extracellular matrix proteins under conditions of meprin inhibition in rats with LPS-induced endotoxemia. Endotoxemia increased the expression of type I, III, IV collagens and fibronectin in the renal tissue and type III and IV collagens in the heart. Meprin inhibitor actinonin reduced expression of both meprins and genes of extracellular matrix proteins, but the intensity of this effect in the heart and kidney was different. Inhibition of meprins in endotoxemia can prevent pathological remodeling of the extracellular matrix in the heart and kidney.

[Pro-inflammatory cytokines in chronic cardiac failure: state of problem].

Systemic inflammation is characterized by the induction of pro-inflammatory cytokines, the increased level of which in the blood of patients with chronic heart failure (CHF) correlates with unfavorable clinical outcomes. However, it is unclear whether pro-inflammatory cytokines are the cause or the consequence of the disease progression. CHF with preserved ejection fraction and CHF with reduced ejection fraction demonstrate different inflammatory features, which suggests different degrees of pro-inflammatory pathway activation. The review deals with participation of pro-inflammatory cytokines in pathophysiological processes of CHF development, emphasizing the role of interleukin-6 activation and the effects of accompanying diseases on the course of systemic inflammation. The search for new approaches to prevention and therapy of CHF remains actual. The review presents the results of clinical trials of targeted anti-cytokine therapy which have revealed difficulties in controlling inflammation under the conditions of CHF. Identification of specific pro-inflammatory pathways in CHF pathogenesis will allow one to control inflammatory cascades, thus providing a prospective therapeutic strategy.

Chemical Reprogramming of Somatic Cells in Neural Direction: Myth or Reality?

In in vitro experiments on cultures of human multipotent stem cells from the human bonearrow and dental pulp, we studied direct reprogramming towards neuro-glial lineage cells using a cocktail of small molecules. Reprogramming by the previously published protocol (with a cocktail containing ß-mercaptoethanol, LIF, VPA, CHIR99021, and RepSox) and by the optimized protocol (VPA, RG108, А83-01, dorsomorphin, thiazovivin, CHIR99021, forskolin, and Isx9) allows obtaining cells with immunophenotypic and genetic signs of neural stem cells. However, neither the former, nor the optimized protocols allowed preparing neural progenitors capable of adequate terminal differentiation from both bone marrow-derived mesenchymal stem cells and nestin-positive neural crest-derived mesenchymal stem cells. Real-time PCR demonstrated the expression of some neurogenesis markers, but neural stem cell-specific expression pattern was not observed. The findings lead us to a conclusion that reprogramming with small molecules without additional factors modifying gene expression does not allow reproducible production of human neural stem cell-like progenitors that can be used as the source of neural tissue for the regenerative therapy.

Tissue Engineered Neural Constructs Composed of Neural Precursor Cells, Recombinant Spidroin and PRP for Neural Tissue Regeneration.

We have designed a novel two-component matrix (SPRPix) for the encapsulation of directly reprogrammed human neural precursor cells (drNPC). The matrix is comprised of 1) a solid anisotropic complex scaffold prepared by electrospinning a mixture of recombinant analogues of the spider dragline silk proteins - spidroin 1 (rS1/9) and spidroin 2 (rS2/12) - and polycaprolactone (PCL) (rSS-PCL), and 2) a "liquid matrix" based on platelet-rich plasma (PRP). The combination of PRP and spidroin promoted drNPC proliferation with the formation of neural tissue organoids and dramatically activated neurogenesis. Differentiation of drNPCs generated large numbers of ßIII-tubulin and MAP2 positive neurons as well as some GFAP-positive astrocytes, which likely had a neuronal supporting function. Interestingly the SPRPix microfibrils appeared to provide strong guidance cues as the differentiating neurons oriented their processes parallel to them. Implantation of the SPRPix matrix containing human drNPC into the brain and spinal cord of two healthy Rhesus macaque monkeys showed good biocompatibility: no astroglial and microglial reaction was present around the implanted construct. Importantly, the human drNPCs survived for the 3 month study period and differentiated into MAP2 positive neurons. Tissue engineered constructs based on SPRPix exhibits important attributes that warrant further examination in spinal cord injury treatment.

[Personality disorders and schizophrenic defect (problem of comorbidity)]. / Rasstroistva lichnosti i shizofrenicheskii defekt (problema komorbidnosti).

AIM: To test the main hypothesis that the deficit phenomena in schizophrenia act not in the 'pure' form, but in the form of aggravating personality characteristics, forming so-called 'common' syndromes with personality disorders (PD). MATERIAL AND METHODS: The results of the psychopathological study (with the use of psychometric methods) of deficit disorders in a sample of 170 patients with schizophrenia and schizophrenia spectrum disorders (63 men, 107 women) are presented in relation to the abnormal structure of premorbid personality (PD of clusters A, B, C). An analysis of negative symptoms according to the comparability of defect to the profile of premorbid personality made it possible to distinguish three groups of deficit states associated with PD - 'common syndromes': defensive schizoidy by the type of deficit schizoid and expansive schizoidy by the type of 'verschroben' (cluster A); pathological hysterical infantilism, malignant hysteria and defective erotomania (cluster B); pseudo-psychasthenia and pathological rationalism (cluster C). RESULTS: It has been found that the symptomatology of 'common syndromes' is subject to patterns reflecting the dichotomy of the basic defect. This pattern is valid not only for one single cluster of PD, but extends to all psychopathy-like disorders, regardless of their affiliation with a particular cluster. The pathocharacterological component of the 'common syndromes' coexisting with the deficit symptom complexes is subject to the basic deficit component of the defect and is separated into polar dimensions (defensive-expansive) within specific clusters of PD, and then unified in accordance with the dichotomy of schizophrenic defect in categories with the predominance of emotional or apathoabulic disorders. CONCLUSION: Psychopathy-like symptom complexes in the space of 'common syndromes' can be qualified as a psychopathological construct secondary to basic deficit disorders, and their isolation as an independent entity of negative disorders appears to be unjustified.

Adult Neural Stem Cells: Basic Research and Production Strategies for Neurorestorative Therapy.

Over many decades, constructing genetically and phenotypically stable lines of neural stem cells (NSC) for clinical purposes with the aim of restoring irreversibly lost functions of nervous tissue has been one of the major goals for multiple research groups. The unique ability of stem cells to maintain their own pluripotent state even in the adult body has made them into the choice object of study. With the development of the technology for induced pluripotent stem cells (iPSCs) and direct transdifferentiation of somatic cells into the desired cell type, the initial research approaches based on the use of allogeneic NSCs from embryonic or fetal nervous tissue are gradually becoming a thing of the past. This review deals with basic molecular mechanisms for maintaining the pluripotent state of embryonic/induced stem and reprogrammed somatic cells, as well as with currently existing reprogramming strategies. The focus is on performing direct reprogramming while bypassing the stage of iPSCs which is known for genetic instability and an increased risk of tumorigenesis. A detailed description of various protocols for obtaining reprogrammed neural cells used in the therapy of the nervous system pathology is also provided.

Compounds of IL-6 Receptor Complex during Acute Lung Injury.

Soluble receptor of IL-6 (sIL-6R) and antagonist of the receptor complex, soluble glycoprotein 130 (sgp130) mediate opposite effects during inflammation. We measured the levels of these cytokines and their ratio in rat blood on the model of acute lung injury. The injury was modeled by the intratracheal administration of LPS. The levels of sgp130 and sIL-6R increased during the inflammatory process in the injured lungs. The sgp130/sIL-6R ratio increased or decreased depending on the intensity of the inflammatory process. sgp130/sIL-6R ratio might reflect the intensity of inflammation during lung injury.

Interaction between Saccharomyces cerevisiae Mitochondrial DNA-Binding Protein Abf2p and Cce1p Resolvase.

Mitochondrial DNA is susceptible to the action of reactive oxygen species generated by the reactions of oxidative phosphorylation. Homologous recombination is one of the mechanisms providing integrity of the mitochondrial genome. Some proteins that take part in this process in budding yeast mitochondria have been identified. These include Abf2p, the major protein of the mt-nucleoid that specifically binds cruciform DNA, and Cce1p - Holliday junction resolvase. Here we show that Abf2p does not significantly affect either binding of Cce1p to branched DNA or rate and specificity of Holliday junction resolution. These data suggest the existence of an alternative homologous recombination pathway in yeast mitochondria.

Binding of DNA with Abf2p Increases Efficiency of DNA Uptake by Isolated Mitochondria.

Mutations in mitochondrial DNA often lead to severe hereditary diseases that are virtually resistant to symptomatic treatment. During the recent decades, many efforts were made to develop gene therapy approaches for treatment of such diseases using nucleic acid delivery into the organelles. The possibility of DNA import into mitochondria has been shown, but this process has low efficiency. In the present work, we demonstrate that the efficiency of DNA import can be significantly increased by preforming its complex with a mitochondria-targeted protein nonspecifically binding with DNA. As a model protein, we used the yeast protein Abf2p. In addition, we measured the length of the DNA site for binding this protein and the dissociation constant of the corresponding DNA-protein complex. Our data can serve as a basis for development of novel, highly efficient approaches for suppressing mutations in the mitochondrial genome.

Microbial Population of the Digestive Tract of Click Beetle Larvae (Elateridae, Coleoptera).

The composition and functional structure of the intestinal microflora of three wireworm species (Agriotes obscurus (L.), Selatosomus aeneus (L.), and Ampedus pomorum (Herbst)) with different dietary regimes were studied. The total abundance of the microorganisms was evaluated by fluorescent microscopy, the group composition was assessed by inoculation on a solid glucose-peptone-yeast medium, and the functional diversity was estimated by multisubstrate testing. It was noted that, in the intestine of the larvae, the total number of microorganisms was lower by 1-2 orders of magnitude than in the soil and decaying wood. It was found that the composition of the intestinal microbial communities of wireworms was radically different from that of the substrate: the Bray-Curtis coefficient did not exceed 0.25. It was found that native forms accounted for more than half of the total number of saprotrophic bacteria: in the larvae, gram-positive cocci, enterobacteria, Vibrionaceae, Acinetobacter, and some genera of coryneform bacteria, which were absent in the soil and wood, prevailed. The micromycetes were either absent (Agriotes) or were found in insignificant quantities (Selatosomus, Ampedus). In Selatosomus, apart from the intestinal forms, representatives of Mezorhizobium, No- cardioides, and Erwinia, occurring on plant substrates, were observed.

[Investigations into the relationship between respiratory disorders and excessive body weight in the adolescents presenting with bronchial asthma treated based at a specialized health resort facility].

A total of 71 patients with bronchial asthma (BA) were examined and treated based at a specialized health facility of whom 43 ones presented with mild asthma and 26 patients with moderately severe asthma in remission. The median age of the patients was 12,04 ± 2,08 years. Spirometry parameters: MOS50, MOS75, and PSV, proved to be of high informative value combined with high enough sensitivity and specificity. The significant difference between the groups as a whole (p < 0.05) were documented based on the serum leptin levels that were higher in the overweight patients and especially in the girls (p < 0.05). The leptin level was a similarly sensitive/specific (AUROC > 0.5) and informative (SCDFC > 0.5) parameter which confirms its diagnostic value given it is employed in combination with overweight for the evaluation of the status of the patients suffering from asthma. Negative linear and non-parametric correlation between the functional parameters and the serum leptin levels in the overweight patients with bronchial asthma suggests that the enhanced leptin concentration may serve as a marker of strong obstruction and severe inflammation at all levels of the respiratory tract in the patients presenting with a combination of the two conditions.