Mesenchymal stem cells lose the senescent phenotype under 3D cultivation.

BACKGROUND: Three-dimensional (3D) cell culture is widely used in various fields of cell biology. In comparison to conventional two-dimensional (2D) cell culture, 3D cell culture facilitates a more accurate replication of the in vivo microenvironment, which is essential for obtaining more relevant results. The application of 3D cell culture techniques in regenerative medicine, particularly in mesenchymal stem cell (MSC)-based research, has been extensively studied. Many of these studies focus on the enhanced paracrine activity of MSCs cultured in 3D environments. However, few focus on the cellular processes that occur during 3D cultivation. METHODS: In this work, we studied the changes occurring within 3D-cultured MSCs (3D-MSCs). Specifically, we examined the expression of numerous senescent-associated markers, the actin cytoskeleton structure, the architecture of the Golgi apparatus and the localization of mTOR, one of the main positive regulators of replicative senescence. In addition, we assessed whether the selective elimination of senescent cells occurs upon 3D culturing by using cell sorting based on autofluorescence. RESULTS: Our findings indicate that 3D-MSCs were able to lose replicative senescence markers under 3D cell culture conditions. We observed changes in actin cytoskeleton structure, Golgi apparatus architecture and revealed that 3D cultivation leads to the nuclear localization of mTOR, resulting in a decrease in its active cytoplasmic form. Additionally, our findings provide evidence that 3D cell culture promotes the phenotypic reversion of senescent cell phenotype rather than their removal from the bulk population. CONCLUSION: These novel insights into the biology of 3D-MSCs can be applied to research in regenerative medicine to overcome replicative senescence and MSC heterogeneity as they often pose significant concerns regarding safety and effectiveness for therapeutic purposes.

Comparison of pcr diagnostic method and mass spectrometry of microbial markers method as applied to the evaluation of oral microbiota.

Rapid informative methods for assessing the species and quantitative composition of the microflora of the periodontal and oropharyngeal covering tissues are necessary for operative diagnostics, including those of the dentofacial system. The use of classical bacteriological methods, including seeding, incubation, counting and identification of microorganisms takes up to 5 days, resulting in a significant delay in obtaining the necessary information, which makes it difficult to carry out operative treatment measures. Therefore, the search for means and methods of operative microbiological control is urgent. The present work is devoted to substantiation of MSMM (mass spectrometry of microbial markers) technology application as a means of microbiological control of periodontal and other oropharyngeal biotopes.

[A novel approach to rapid induction of remission in primary membranous nephropathy].

AIM: То evaluate the effectiveness of a novel multi-targeted treatment approach including rituximab (RTX), cyclophosphamide (CPH) and steroids (S) to the induction of remission in patients with primary membranous nephropathy (PMN) compared to standard immunosuppression (IST). MATERIALS AND METHODS: An open-label prospective comparative study included 56 PMN patients (pts) with nephrotic syndrome (NS) and high serum level of antibodies to the phospholipase A2 receptor anti-PLA2R (mean age 5112 years, men 70%). We recorded demographic and clinical parameters at the time of kidney biopsy, data from light-optical and immunomorphological studies. All pts were on stable doses of the renin-angiotensin systems blockers. We compared the effectiveness of different treatments in the inductions of clinical and immunological remissions in pts who received experimental treatment with RTX, CPH and S (RTX+CPH+S group, n=14) and two control groups: high-dose RTX therapy (group RTX, n=12), cyclosporine and steroids (group CsA+S, n=30). RESULTS: In the RTX+CPH+S group, remission was achieved in 100% of cases (of which complete remissions CR in 21.4%). The median time-to-remission (2.5 [1.0; 3.5] months) was significantly lower compared to both control groups: RTX (8.7 [6.6; 14.0] months, p=0.005) and CsA+S (12.4 [6.5; 19.9] months, p0.001). The cumulative incidence of clinical and immunological remissions was also significantly higher in the RTX+CPH+S group than in the control groups. These results were confirmed in comparative analyzes in the same treatment groups after propensity score matching. The cumulative incidence of clinical and immunological remissions in the RTX+CPH+S group was higher than in the combined group of patients who received other therapies (p0.001). The incidence of serious adverse events was low and did not differ between groups. CONCLUSION: The use of multi-targeted therapy with rituximab, cyclophosphamide, and steroids seems to be an effective approach for the rapid induction of PMN remission and prevention of NS complications.

[Gut microbiota and systemic inflammation in patients with chronic heart failure].

Aim To study the interrelationship between intensity of chronic systemic inflammation (CSI) with severity of the condition and intestinal microbiocenosis parameters in patients with chronic heart failure (CHF).Material and methods 47 hospitalized patients with symptomatic CHF were evaluated. The following parameters were determined: clinical condition; N-terminal pro-B-type natriuretic peptide (NT-proBNP). C-reactive protein (CRP); serum interleukins (IL) 6 and 10; and intestinal microbiocenosis composition by mass-spectrometry of microbial markers in whole blood. Microbiocenosis indexes were compared in the main group and in 38 outpatient patients with arterial hypertension and ischemic heart disease without CHF.Results Direct, medium-power correlations were found between CRP and IL-6 concentrations and severity of clinical condition (NT-proBNP, ХСН stage, and edema severity) in patients with CHF. Most patients with CHF had lower numbers of bifido-, lacto-, propionic-, and eubacteria, and Clostridium (С.) ramosum and higher numbers of aspergillus. Among CHF patients, the highest indexes of endotoxemia, gram (-) bacteria, cocci, actinomycetes, and microfungi were observed in the group with NT-proBNP from 400 to 2000 pg/ml. Direct correlations were observed for amounts of C. hystolyticum, Pseudonocardia spp., and Aspergillus spp. with IL-6 and IL-10 and unidirectional inverse correlation were observed for these cytokines with Propionibacterium acnes and jensenii, Streptomyces spp., and Nocardia asteroides. In addition, IL-6 concentration was negatively correlated with contents of Staphylococcus aureus, C. difficile, C. ramosum, Eggerthella lenta, and Corynebacterium spp. and was positively correlated with C. propionicum, Moraxella spp. and Flavobacterium spp. Concentration of IL-6 directly correlated with the number of Eubacterium spp. and inversely correlated with numbers of Ruminicoccus spp. and Streptomyces farmamarensis. The amount of Streptomyces farmamarensis negatively correlated with CRP concentrations.Conclusion The study results evidence the significance of intestinal microbial-tissue complex in the pathogenesis of CSI in CHF and allow suggesting this complex as a promising target for therapy.

Effect of Prebiotic Complex on Gut Microbiota and Endotoxemia in Female Rats with Modeled Heart Failure.

We studied the levels endotoxin and microbial markers in the blood of female rats with experimental heart failure and the effects of preliminary treatment with a prebiotic complex based on fermented wheat bran and inactivated Saccharomyces cerevisiae culture on these parameters. The concentrations of endotoxin, markers of lactobacilli, and opportunistic microorganisms were found to increase in rats with experimental heart failure and significantly decreased against the background of treatment with prebiotic complex. The dynamics of markers of bifidobacteria, eubacteria, and propionibacteria were reciprocal. The observed effect of the prebiotic complex effect on gut microbiota in rats with experimental heart failure suggests that this complex can be used for the correction of intestinal dysbiosis and endotoxemia in this clinical condition.

[ULTRASTRUCTURAL CHANGES OF THE STEM CELLS IN THE CYCLE MONOLAYER--SPHERES--MONOLAYER].

Sphere formation can be used to prepare stem cells (SCs) prior to transplantation. Here SCs isolated from human subepicardial adipose tissue were analyzed at different stages of the monolayer-spheres-monolayer cycle by transmission electron microscopy. The results obtained with both adherent-induced and hanging-drop induced spheres were similar. At first 2-3 passages (stage 1), isolated SCs displayed embryonal cell-like ultrastructure. With increasing passage times (stage 2), SCs became bigger and more electron-dark with a multilobed nucleus, well-developed rough endoplasmic reticulum (RER), prominent Golgi apparatus and numerous vacuoles. After 2 h from the initiation of the formation of spheres (stage 3), SCs gathered into clusters and formed desmosome-like intercellular contacts. Their nucleus possessed a large loose fibrillo-granular nucleoli, the cytoplasm was densely packed with disintegrated cisternae of RER, Golgi apparatus was not detected. After 24 h from the initiation of spheres (stage 4), SCs in well-formed spheres exhibited large dense nucleoli and poorly developed Golgi apparatus and RER. One day after sphere dissociating (stage 5), SCs were embryonal cell-like and morphologically similar to the cells of the first stage except for the presence of a large nucleolus and numerous Golgi complexes. After 48 h from sphere dissociating (stage 6), SCs became electron-dark and resembled the SCs of the second stage by the presence of irregularly shaped nuclei and the cetoplasm filled with RER. We interpreted the results as senescence of the SCs with the number of passages after isolation from tissue and a day after dissociation of the spheres and as rejuvenation of the SCs just after sphere dissociation. Further research is needed to reveal the genetic, biochemical and physiological parameters of the SCs on established morphologically distinct stages in order to provide higher-quality cellular material for disease cell therapy.

[Case of restoration of reproductive function using the method of cryopreservation and autotransplantation of ovarian tissue in a Hodgkin's lymphoma patient].

Recent advances of cancer treatment resulted in the increase of patient survival rate. Treatment for Hodgkin's lymphoma (HL) may impair reproductive function, which leads to a decrease of the quality of life of cancer survival. Today different approaches have been developed for fertility preservation, one of which is the cryopreservation of ovarian tissue with subsequent orthotopic transplantation. We have described a recovery of reproductive function in patient of 28 years with acute ovarian failure, which was induced after cancer treatment. After the orthotopic transplantation cryopreserved ovarian tissue ongoing pregnancy was achieved in the natural cycle after IVF insemination. We have described the first live birth in Russia after the orthotopic transplantation cryopreserved ovarian tissue in cancer patient. This approach has resulted in the recovery of endocrine function without replacement hormonal therapy and possibility for a woman to have her own biological baby. It suggests that cryopreservation of ovarian tissue should be offered to all young women diagnosed with cancer.

Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

[Neuropeptides, Cytokines and Thymus Peptides as Effectors of Interactions Between Thymus and Neuroendocrine System].

The review presents data on mutual influence of nervous system and thymus, realized through the neuroendocrine-immune interactions. The pres- ence of adrenergic and peptidergic nerves in thymus creates conditions for implementation of the effect of neuropeptides secreted by them. These neuropeptides induce activation of thymus cells receptors and influence on the main processes in thymus, including T-lymphocyte maturation, cytokine and hormones production. In turn, thymuspeptides and/or cytokines, controlled by them, enter the brain and exert influence on neuro- nalfunction, which creates the basis for changes of behavior and homeostasis maintenance in response to infection. Ageing and some infectious, autoimmune, neurodegenerative and cancer diseases are accompanied by distortion of interactions between thymus and central nervous system. Mechanisms of signaling pathways, which determine these interactions, are not revealed yet, and their understanding will promote the development of effective therapeutic strategies.

[Comparative characteristics of the stem cells isolated from subcutaneous and subepicardial adipose tissue].

BACKGROUND: Stem cells (SCs) considerably vary in morphological, immunophenotypic, proliferative, and differentiation characteristics depending on their tissue source. The comparative analysis of their biological properties is essential for the optimal choice of SCs for regenerative therapies. METHODS: Using immunocytochemistry, flow cytometry, histochemistry and real-time RT-PCR, we have investigated SCs obtained from human subepicardial (SEC-AT) and subcutaneous (SC-AT) adipose tissue and cultured under similar culture conditions without any differentiation-promoting factors. RESULTS: The cultures were similar in the high proportion of proliferating cell nuclear antigen (PCNA)-positive cells. In both cultures, immunophenotyping has revealed high expression of mesenchymal stem cell surface markers CD29, CD44, CD73, and CD105, low expression of CD31, CD34 and CD45, and wide variability in CD117, CD146 and CD309 expression. The only distinction in CD marker profile was significantly lower expression of CD90 in SCs from SEC-AT. Histochemical analysis has shown the lack of Oil Red O-positive cells in both cultures and about ten-fold higher number of alkaline phosphatase-positive cells among SCs from SC-AT. In the both cultures, immunocytochemistry has detected similar low expression of slow myosin heavy chain marker MAB1628 and smooth muscle actin marker α-hSMA. Gap junctional protein Connexin-43 expression was markedly higher in SCs from SC-AT, and epithelial cell marker Cytokeratin-19 expression was detected only in these cells. By RT-PCR, GATA4 mRNA was found to be highly expressed only in SCs from SEC-AT. CONCLUSIONS: Our results suggest that SC-AT, as compared with SEC-AT, is richer in epithelial cell and osteogenic progenitors. In turn, SEC-AT possesses cardiomyogenic SCs, and can be considered as an alternative to SC-AT as a source of SCs for cell cardiotherapy.

[The impact of immunoactive drugs on passive avoidance response].

AIM: The objective of this project was to explore the influence of immunoactive drugs (tactivin, thymulin, and thymosin fraction 5) on the development of the passive avoidance conditioned reflex. MATERIALS AND METHODS: Two types of passive avoidance boxes were used--a regular two-chamber box and a modified three-chamber box, comprising a dark chamber in which rats were exposed to electrical shock, a safe dark chamber, and a light chamber in the center. RESULTS: The project has established that the memory trace persists longer under the influence of the immunoactive drugs in both models, which is consistent with the reference nootropic piracetam test results. Notably, the immunoactive drugs' mnemotropic effect was more pronounced in the modified three-chamber box than in the standard two-chamber box. Using the modified box helped to establish the influence of tactivin, thymulin, and thymosin fraction 5 on the spatial memory component. Immunotropic preparations from thymus caused the animals to select the safe chamber 24 hours later and in subsequent tests. CONCLUSION: The project's results indicate that the drugs tested do possess mnemotropic properties, so their range of clinical use can be broadened.

[The presence and localization of heat shock protein 70 in rat mast cells].

Heat shock protein 70 (Hsp70) is considered not only as a cytosolic stress protein, but also as an extracellular molecule with immunomodulatory and signaling functions that play a role in adaptation to stress on cellular and systemic levels. The active involvement of mast cells in adaptation to stress may be associated with the presence of Hsp70 in secretory granules. Using immunoelectron microscopy, we showed that Hsp70 localized in secretory granules of rat pericardial and peritoneal mast cells. Localization of Hsp70 in rat perinoneal mast cells isolated by centrifugation on Percoll was confirmed by immunoblotting. The proposed involvement of mast cells in production of extracellular Hsp70 and possible functions of Hsp70 inside the mast cells granules are discussed.

Functional characterization and biological significance of Yersinia pestis lipopolysaccharide biosynthesis genes.

In silico analysis of available bacterial genomes revealed the phylogenetic proximity levels of enzymes responsible for biosynthesis of lipopolysaccharide (LPS) of Yersinia pestis, the cause of plague, to homologous proteins of closely related Yersinia spp. and some other bacteria (Serratia proteamaculans, Erwinia carotovora, Burkholderia dolosa, Photorhabdus luminescens and others). Isogenic Y. pestis mutants with single or double mutations in 14 genes of LPS biosynthetic pathways were constructed by site-directed mutagenesis on the base of the virulent strain 231 and its attenuated derivative. Using high-resolution electrospray ionization mass spectrometry, the full LPS structures were elucidated in each mutant, and the sequence of monosaccharide transfers in the assembly of the LPS core was inferred. Truncation of the core decreased significantly the resistance of bacteria to normal human serum and polymyxin B, the latter probably as a result of a less efficient incorporation of 4-amino-4-deoxyarabinose into lipid A. Impairing of LPS biosynthesis resulted also in reduction of LPS-dependent enzymatic activities of plasminogen activator and elevation of LD(50) and average survival time in mice and guinea pigs infected with experimental plague. Unraveling correlations between biological properties of bacteria and particular LPS structures may help a better understanding of pathogenesis of plague and implication of appropriate genes as potential molecular targets for treatment of plague.

[A sharp increase in the density of pulmonary and pericardial mast cells under monocrotaline-induced pulmonary hypertension in rats].

Multifunctional granular mast cells (MCs) are involved in various pathological processes. The response of MC populations of myocardium, pericardium and lung to pulmonary hypertension (PH) has been studies 8 weeks after injection of monocrotaline. Five intact and five experimental rats were used. The density of MCs of different maturity was estimated on paraffin sections stained with Alcian blue and Safranin. Expressiveness of PH was estimated by functional parameters with the help of echocardiograms and by morphological markers. The MC density in myocardium of the intact and experimental rats was relatively low: 2 to 4 cells/mm2. MC density in the pericardium of intact rats was 14 times higher than in myocardium and increased 3 times for PH. The mature Safranin-positive cells predominated (70-80%) in myocardium and pericardium of intact and experimental rats. The MC density in the lungs of intact rats was about 30 cells/mm2; 98% of these cells were immature Alcian-positive cells. The mean density of MCs in the lungs of rats with PH increased 5.6 times. The mature Safranin-positive cells appeared in the lungs of rats with severe pathology. The greatest number of MCs in lungs was in the rats with the most pronounced disorders of myocardium function and marked histological damages (injuries) of myocardium and lungs. The finding show active response of MC population to monocrotaline-induced PH that stimulates migration of immature MCs into pericardium and lungs from the outside. Our data indicate the important role of MCs in the pathogenesis of PH.

Pleiotropic effects of the lpxM mutation in Yersinia pestis resulting in modification of the biosynthesis of major immunoreactive antigens.

Deletion mutants in the lpxM gene in two Yersinia pestis strains, the live Russian vaccine strain EV NIIEG and a fully virulent strain, 231, synthesise a less toxic penta-acylated lipopolysaccharide (LPS). Analysis of these mutants revealed they possessed marked reductions in expression and immunoreactivity of numerous major proteins and carbohydrate antigens, including F1, Pla, Ymt, V antigen, LPS, and ECA. Moreover, both mutants demonstrated altered epitope specificities of the antigens as determined in immunodot-ELISAs and immunoblotting analyses using a panel of monoclonal antibodies. The strains also differed in their susceptibility to the diagnostic plague bacteriophage L-413C. These findings indicate that the effects of the lpxM mutation on reduced virulence and enhanced immunity of the Y. pestis EV DeltalpxM is also associated with these pleiotropic changes and not just to changes in the lipid A acylation.

[Serum-blood serotonin level as a marker of panic attacks severity and effectiveness of their treatment].

Twenty-eight males with psychogenic (emotiogenic) autonomic dystonia with paroxysmal course (panic attacks) have been studied. Serum serotonin (S) concentration has been measured using ELISA. The deficit (147,36+/-69,80 ng/ml) of humoral S has been found compared to a control group (295,18+/-152,38 ng/ml). After the 8-weeks treatment with a SSRIs antidepressant rexetin in dosage 20 mg/day, a distinct clinical effect has been observed. There was a decrease of the number and severity of paroxysms as well as severity of symptoms of psychoautonomic syndrome (the reduction of depression, anxiety and optimization of autonomic regulation). Despite the therapeutic effectiveness of rexetin, serum S concentration has decreased still more to 59,92+/-23,06 ng/ml. The paradoxical phenomenon of growing deficit in the humoral pattern of serotonergic system during the short-term course of SSRIs antidepressant treatment is reviewed as a result of the transfer of neuromediator from the blood to the cerebral structures with the following activation of serotonergic system that provides the therapeutic effect.

[Localization of substance P- and FMRFamide-like immunoreactivity in the atrium of the snail Achatina fulica].

By immunohistochemical and immunocytochemical methods localization of Substanse P (SP) and FMRFamide in the atrium of the snail Achatina fulica was investigated. Nerve fibers innervating the snail atrium contact tightly with the granular cells (GC) situated between muscle and endocardial cells, forming neuroendocrine units. Both neuromediators were found in the cells of the neuroendocrine units. By immunohistochemistry SP- and FMRFamide-immunoreactive material was revealed in the granules of the atrial GC. Elecrtonmicroscopical immunocytochemistry has confirmed the presence of SP- and FMRFamide-immunoreactive material in the granules of the GC and shown their presence in the neurosecretory granules of the nerve endings contacting both the atrial GC and cardiomyocytes.

[Synthesis of nucleic acids and localization of atrial natriuretic peptide in the crayfish haemocytes].

Three types of cells circulate in haemolymph of the crayfish Astacus astacus: agranular haemocytes (HCs I), small-granule haemocytes (HCs II) and large-granule haemocytes (HCs III). Their proliferation, differentiation and function remain poorly understood. By means of light and electron microscopic autoradiography using [3H]-thymidine, we have revealed that only HCs I are capable of DNA synthesis and mitosis whereas HCs II and HCs III are replicatively inactive. To determine whether the HCs I are proliferating progenitor cells for the granular HCs, we have analyzed autographs of HC population in 1, 2, 7 and 21 days after a single [3H]-thymidine administration. Contrary to the expectation, we have failed to find labeled HCs II and HCs III. These findings raise doubts on the capacity of the HCs I to differentiate into two other types of HCs. By autoradiography using 3H-uridine, it has been detected that intensity of the RNA synthesis was the greatest in HCs I and less by a factor of two and four in HCs II and HCs III, respectively. Additionally, by EM immunocytochemistry, ANP-like immunoreactivity was revealed in the large granules of the HCs III. We assume that availability of ANP in secretory granules extends the possible functions of the crayfish HCs and suggests their participation in regulation of water-salt balance and immune responses.

Structural diversity and endotoxic activity of the lipopolysaccharide of Yersinia pestis.

The endotoxic activity of the lipopolysaccharides (LPS) with defined chemical structure from Yersinia pestis strains of various subspecies differing in their epidemic potential was studied. The LPS of two strains of Y. pestis ssp. caucasica and ssp. altaica, whose structures have not been studied earlier, were analyzed by high-resolution mass spectrometry. In addition to reported structural changes, an increase in the degree of LPS phosphorylation was observed when strain I-2377 (ssp. altaica) was cultivated at an elevated temperature. A high tumor necrosis factor alpha(TNF-alpha)-inducing activity observed for LPS samples from Y. pestis cultures grown at 25 degrees C correlated with an increased degree of lipid A acylation, particularly, with the presence of the hexaacyl form of lipid A, which was absent from the LPS when bacteria were cultivated at 37 degrees C. No correlation was found between the lethal toxicity of the LPS in vivo and its ability to induce TNF-alpha production in vitro.

A Yersinia pestis lpxM-mutant live vaccine induces enhanced immunity against bubonic plague in mice and guinea pigs.

The lpxM mutant of the live vaccine Yersinia pestis EV NIIEG strain synthesising a less toxic penta-acylated lipopolysaccharide was found to be avirulent in mice and guinea pigs, notably showing no measurable virulence in Balb/c mice which do retain some susceptibility to the parental strain itself. Twenty-one days after a single injection of the lpxM-mutant, 85-100% protection was achieved in outbred mice and guinea pigs, whereas a 43% protection rate was achieved in Balb/c mice given single low doses (10(3) to 2.5 x 10(4) CFU) of this vaccine. A subcutaneous challenge with 2000 median lethal doses (equal to 20,000 CFU) of fully virulent Y. pestis 231 strain, is a 6-10-fold higher dose than that which the EV NIIEG itself can protect against.