Publications by authors named "Nikolaev M"

The intimate relationship between the epithelium and immune system is crucial for maintaining tissue homeostasis, with perturbations therein linked to autoimmune disease and cancer. Whereas stem cell-derived organoids are powerful models of epithelial function, they lack tissue-resident immune cells that are essential for capturing organ-level processes. We describe human intestinal immuno-organoids (IIOs), formed through self-organization of epithelial organoids and autologous tissue-resident memory T (T) cells, a portion of which integrate within the epithelium and continuously survey the barrier.

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Existing organoid models fall short of fully capturing the complexity of cancer because they lack sufficient multicellular diversity, tissue-level organization, biological durability and experimental flexibility. Thus, many multifactorial cancer processes, especially those involving the tumor microenvironment, are difficult to study ex vivo. To overcome these limitations, we herein implemented tissue-engineering and microfabrication technologies to develop topobiologically complex, patient-specific cancer avatars.

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Organoids and organs-on-a-chip have emerged as powerful tools for modeling human gut physiology and disease in vitro. Although physiologically relevant, these systems often lack the environmental milieu, spatial organization, cell type diversity, and maturity necessary for mimicking human intestinal mucosa. To instead generate models closely resembling in vivo tissue, we herein integrated organoid and organ-on-a-chip technology to develop an advanced human organoid model, called "mini-colons.

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Three-dimensional organoid culture technologies have revolutionized cancer research by allowing for more realistic and scalable reproductions of both tumour and microenvironmental structures. This has enabled better modelling of low-complexity cancer cell behaviours that occur over relatively short periods of time. However, available organoid systems do not capture the intricate evolutionary process of cancer development in terms of tissue architecture, cell diversity, homeostasis and lifespan.

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Article Synopsis
  • Recent studies suggest that there may be a connection between lysosomal storage disorders (LSDs) and symptoms of schizophrenia (SCZ), indicating that lysosomal dysfunction could play a role in SCZ development.
  • The research involved analyzing lysosomal enzyme activities and alpha-synuclein levels in blood samples from patients with late-onset SCZ and comparing them to patients with Parkinson's disease and healthy controls.
  • Significant differences were found, including decreased enzyme activity, higher concentrations of certain lysosphingolipids, and genetic variants linked to LSDs in early-onset SCZ patients, which may contribute to understanding the overlap between these conditions.
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Liver organoids have emerged as promising in vitro models for toxicology, drug discovery, and disease modeling. However, conventional 3D epithelial organoid culture systems suffer from significant drawbacks, including limited culture duration, a nonphysiological 3D cystic anatomy with an inaccessible apical surface, and lack of in vivo-like cellular organization. To address these limitations, herein a hydrogel-based organoid-on-a-chip model for the development functional tubular biliary organoids is reported.

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The action of tetraalkylammonium ions, from tetrametylammonium (TMA) to tetrapentylammonium (TPtA), on the recombinant and native acid-sensing ion channels (ASICs) was studied using the patch-clamp approach. The responses of ASIC1a, ASIC2a, and native heteromeric ASICs were inhibited by TPtA. The peak currents through ASIC3 were unaffected, whereas the steady-state currents were significantly potentiated.

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Glutamate ionotropic receptors mediate fast excitation processes in the central nervous system of vertebrates and play an important role in synaptic plasticity, learning, and memory. Here, we describe the action of two azobenene-containing compounds, AAQ (acrylamide-azobenzene-quaternary ammonium) and QAQ (quaternary ammonium-azobenzene-quaternary ammonium), which produced rapid and fully reversible light-dependent inhibition of glutamate ionotropic receptors. The compounds demonstrated voltage-dependent inhibition with only minor voltage-independent allosteric action.

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Embryo implantation into the uterus marks a key transition in mammalian development. In mice, implantation is mediated by the trophoblast and is accompanied by a morphological transition from the blastocyst to the egg cylinder. However, the roles of trophoblast-uterine interactions in embryo morphogenesis during implantation are poorly understood due to inaccessibility in utero and the remaining challenges to recapitulate it ex vivo from the blastocyst.

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F-type ATP synthases play a key role in oxidative and photophosphorylation processes generating adenosine triphosphate (ATP) for most biochemical reactions in living organisms. In contrast to the mitochondrial FF-ATP synthases, those of chloroplasts are known to be mostly monomers with approx. 15% fraction of oligomers interacting presumably non-specifically in a thylakoid membrane.

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Mutations in the gene, encoding the lysosomal enzyme glucocerebrosidase (GCase), cause Gaucher disease (GD) and are the most common genetic risk factor for Parkinson's disease (PD). Pharmacological chaperones (PCs) are being developed as an alternative treatment approach for GD and PD. To date, NCGC00241607 (NCGC607) is one of the most promising PCs.

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Transcriptomic analysis conducted by us previously revealed upregulation of genes involved in low-density lipoprotein particle receptor (LDLR) activity pathway in lethal COVID-19 caused by SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus 2). Last data suggested the possible role of extracellular vesicles in COVID-19 pathogenesis. The aim of the present study was to retrospectively evaluate parameters of cholesterol metabolism and newly identified EVs, exomeres, as possible predictors of fatal outcome of COVID-19 patients infected by the Alpha and the Delta variants of SARS-CoV-2 virus.

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The pharmacology of acid-sensitive ion channels (ASICs) is diverse, but potent and selective modulators, for instance for ASIC2a, are still lacking. In the present work we studied the effect of five 2-aminobenzimidazole derivatives on native ASICs in rat brain neurons and recombinant receptors expressed in CHO cells using the whole-cell patch clamp method. 2-aminobenzimidazole selectively potentiated ASIC3.

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Article Synopsis
  • - NMDA receptors are crucial for many functions in the central nervous system (CNS), which has led to the need for specialized compounds that can modulate their activity.
  • - Researchers discovered light-sensitive compounds derived from DENAQ that inhibit NMDA receptor activity, with structural variations significantly affecting their effectiveness and light sensitivity.
  • - Among these compounds, PyrAQ showed the strongest effects, allowing for rapid and reversible NMDA receptor inhibition, making it a valuable tool for studying receptor function through light-based methods.
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  • Parathyroid hormone (PTH) is crucial for calcium and phosphate metabolism, governing bone health and kidney function.
  • The study explores how PTH affects mesenchymal stromal cells (MSCs) at a single-cell level, revealing that PTH induces distinct calcium responses that influence MSC behavior.
  • Specifically, a smooth increase in calcium boosts bone formation, while calcium oscillations reduce the process of osteogenesis, highlighting the balance between different calcium signaling pathways in cell differentiation.
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Apamin is often cited as one of the few substances selectively acting on small-conductance Ca-activated potassium channels (K2). However, published pharmacological and structural data remain controversial. Here, we investigated the molecular pharmacology of apamin by two-electrode voltage-clamp in oocytes and patch-clamp in HEK293, COS7, and CHO cells expressing the studied ion channels, as well as in isolated rat brain neurons.

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Epithelial organoids are stem cell–derived tissues that approximate aspects of real organs, and thus they have potential as powerful tools in basic and translational research. By definition, they self-organize, but the structures formed are often heterogeneous and irreproducible, which limits their use in the lab and clinic. We describe methodologies for spatially and temporally controlling organoid formation, thereby rendering a stochastic process more deterministic.

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To assess the biology of the lethal endpoint in patients with SARS-CoV-2 infection, we compared the transcriptional response to the virus in patients who survived or died during severe COVID-19. We applied gene expression profiling to generate transcriptional signatures for peripheral blood mononuclear cells (PBMCs) from patients with SARS-CoV-2 infection at the time when they were placed in the Intensive Care Unit of the Pavlov First State Medical University of St. Petersburg (Russia).

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Mutations of the gene, encoding for lysosomal enzyme glucocerebrosidase (GCase), are the greatest genetic risk factor for Parkinson's disease (PD) with frequency between 5% and 20% across the world. N370S and L444P are the two most common mutations in the gene. PD carriers of severe mutation L444P in the gene is characterized by the earlier age at onset compared to N370S.

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Azobenzene-based quaternary ammonium compounds provide optical control of ion channels and are considered promising agents for regulation of neuronal excitability and for restoration of the photosensitivity of retinal cells. However, the selectivity of the action of these compounds remains insufficiently known. We studied the action of DENAQ (diethylamine-azobenzene-quaternary ammonium) and DMNAQ (dimethylamine-azobenzene-quaternary ammonium) on ionotropic glutamate receptors in rat brain neurons.

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Two-component systems (TCS) are widespread signaling systems present in all domains of life. TCS typically consist of a signal receptor/transducer and a response regulator. The receptors (histidine kinases, chemoreceptors and photoreceptors) are often embedded in the membrane and have a similar modular structure.

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Mutations in the glucocerebrosidase gene (GBA) encoding the lysosomal enzyme glucocerebrosidase (GCase) cause Gaucher disease (GD) and are the most commonly known genetic risk factor for Parkinson disease (PD). Ambroxol is one of the most effective pharmacological chaperones of GCase. Fourteen GD patients, six PD patients with mutations in the GBA gene (GBA-PD), and thirty controls were enrolled.

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N-methyl-d-aspartate glutamate receptors (NMDARs) are involved in numerous central nervous system (CNS) processes, including epileptiform activity. We used a picrotoxin-induced epileptiform activity model to compare the action of different types of NMDAR antagonists in rat brain slices. Paroxysmal depolarizing shifts (PDS) were evoked by external stimulation in the medial prefrontal cortex (mPFC) slices and recorded in pyramidal cells (PC) and in fast-spiking interneurons (FSI).

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