Simulation of Microgravity and Coculturing with Hematopoietic Cells Oppositely Modulate Wnt Signaling in Mesenchymal Stromal Cells.

The osteogenic potential of mesenchymal stromal cells (MSCs) can determine bone homeostasis and the physical characteristics of bones. Microgravity reduces the ability of these cells to differentiate in osteogenic direction. It has been shown that the addition of hematopoietic stem and progenitor cells (HSPCs) to MSC culture in vitro can have the opposite effect. The aim of this study was to identify transcriptional changes in 84 genes associated with Wnt signaling in MSCs during microgravity simulation and interaction with HSPCs. The results indicate an increase in the non-canonical Wnt signaling activity during coculturing of MSCs and HSPCs, while simulated microgravity enhances the canonical component of this signaling pathway. These changes may underlie the modulation of osteogenic potential of MSCs in hematopoietic niche under microgravity.

Neuro-Immune Aspects of Schizophrenia with Severe Negative Symptoms: New Diagnostic Markers of Disease Phenotype.

The aim of the study was to analyze the immune-inflammatory profile of patients with paranoid schizophrenia and relate it to the severity of negative symptoms and the MRI data in order to identify biomarkers of schizophrenia severity, search for new approaches to therapy, and control its effectiveness. Materials and Methods: The main group included 51 patients with paranoid schizophrenia, the control group - 30 healthy subjects. Patients underwent MRI scans and immunological studies, which included an assessment of natural and adaptive immunity, the systemic level of key pro-inflammatory and anti-inflammatory cytokines, and other markers of inflammation. Results: Disorders of immunity and immunoinflammatory profile in patients with paranoid schizophrenia with severe negative symptoms were revealed for the first time: in the presence of severe negative symptoms (>15 points according to the NSA-4 scale), the levels of humoral immunity factors, cytokines IL-10 and IL-12p40 and neurotrophin NGF were increased as well as the markers of systemic inflammation. Morphometric changes in the brain, typical for patients with schizophrenia, and also specific for patients with severe negative symptoms, were determined. The data analysis revealed correlations between the immune changes with structural changes in some of the brain areas, including the frontal cortex and hippocampus. Associations were found between the levels of anti-inflammatory IL-10, IL-12p40 cytokines and morphometric parameters of the brain, specific only for schizophrenic patients with severe negative symptoms. Conclusion: The interdisciplinary approach, combining brain morphometry with in-depth immunological and clinical studies, made it possible to determine neurobiological, immune, and neurocognitive markers of paranoid schizophrenia with severe negative symptoms. The results are important for further deciphering the pathogenesis of schizophrenia and its subtypes, as well as for the search for new approaches to the treatment of severe forms of the disease.

Replicative Senescence and Expression of Autophagy Genes in Mesenchymal Stromal Cells.

Cell senescence leads to a number of changes in the properties of mesenchymal stromal cells (MSCs). In particular, the number of damaged structures is increased producing negative effect on intracellular processes. Elimination of the damaged molecules and organelles occurs via autophagy that can be important in the context of aging. Cultivation under low oxygen level can be used as an approach for enhancement of MSC therapeutic properties and "slowing down" cell senescence. The goal of this work was to study some morphological and functional characteristics and expression of autophagy-associated genes during replicative senescence of MSCs under different oxygen concentration. The study revealed changes in the regulation of autophagy at the transcriptional level. Upregulation of the expression of autophagosome membrane growth genes ATG9A and ULK1, of the autophagosome maturation genes CTSD, CLN3, GAA, and GABARAPL1, of the autophagy regulation genes TP53, TGFB1, BCL2L1, FADD, and HTT was shown. These changes were accompanied by downregulation of IGF1 and TGM2 expression. Increase of the lysosomal compartment volume was observed in the senescent MSCs that also indicated increase of their degradation activity. The number of lysosomes was decreased following prolonged cultivation under low oxygen concentration (5%). The replicative senescence of MSCs under conditions of different oxygen levels led to the similar modifications in the expression of the autophagy-associated genes.

Expression of senescence-associated genes in multipotent mesenchymal stromal cells during long-term cultivation at various hypoxic levels.

The expression of several genes which functions are associated with cellular senescence was analyzed in multipotent mesenchymal stromal cells during long-term cultivation at different oxygen levels (20, 5, and 1%) using the RT² Profiler™ PCR Array Human Cellular Senescence system (Qiagen, United States). It was established that replicative senescence processes develop most actively in the cells cultured under the standard conditions (20% O2). The most significant changes were observed in the expression of CCND1, ID1, IGF1, PIK3CA, and SERPINE1 genes.