Vestnik Moskovskogo universiteta. Seria 16. Biologia最新文献

{"title":"Cryo-electron microscopy at the Faculty of Biology of Lomonosov Moscow State University","authors":"A. V. Moiseenko, A.M. Egorov, K. V. Shaitan, O. S. Sokolova","doi":"10.55959/10.55959/msu0137-0952-16-78-3s-9","DOIUrl":"https://doi.org/10.55959/10.55959/msu0137-0952-16-78-3s-9","url":null,"abstract":"This paper demonstrates an example of a successful upgrade of a JEOL JEM-2100 analytical transmission electron microscope to a low-resolution cryo-electron microscope designed for routine tasks of sample preparation and quality evaluation. As a result of the upgrade, the instrument allows the subnanometer resolution of protein molecule reconstructions (within 8 Å). The influence of graphene and amorphous carbon support films to prevent the effect of preferred orientation of protein particles in the frozen sample is discussed.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"6 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139166752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How does a biopolymer (protein) fold into a unique 3D structure?","authors":"K. V. Shaitan","doi":"10.55959/10.55959/msu0137-0952-16-78-3s-2","DOIUrl":"https://doi.org/10.55959/10.55959/msu0137-0952-16-78-3s-2","url":null,"abstract":"The current state of the problem of folding proteins and other biopolymers is discussed. The\u0000concept of a multidimensional potential energy surface and a free energy surface for linear\u0000polymers is detailed, taking into account the topology of the configuration space and the\u0000presence of symmetry elements with respect to the permutation of identical monomer units. The\u0000presence of kinematic bonds for conformational movements in a viscous medium leads to a\u0000tendency to form helical structures of linear polymers. The dynamic effects of viscosity also lead\u0000to an almost uniform distribution of energy dissipation rates over the chain nodes. The\u0000combination of potential energy surface topography and viscosity effects provides a physical\u0000basis for the development of the theory of folding in the direction of interpreting various\u0000experimental observations and elucidating the principles for the formation of an amino acid\u0000code for 3D protein structures. The relationship between the denaturation temperature of the\u0000folded state of the biopolymer and the energy of non-valent interactions between monomers in\u0000the chain is analyzed.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"16 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138951199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryo-electron microscopy of enveloped viruses using upgraded transmission electron microscope: Influenza type A, B viruses and SARS-CoV-2","authors":"L. Kordyukova, A. V. Moiseenko, T.A. Timofeeva, I.T. Fedyakina","doi":"10.55959/10.55959/msu0137-0952-16-78-3s-4","DOIUrl":"https://doi.org/10.55959/10.55959/msu0137-0952-16-78-3s-4","url":null,"abstract":"Cryo-electron microscopy (cryo-EM) is indispensable for the structural studies of enveloped viruses – dangerous pathogens of humans and animals. Yet, it requires highly specialized equipment as well as careful sample preparation. In this work, the capabilities of transmission electron microscope JEOL JEM-2100 equipped with cryo-transfer holder are used, and preliminary cryo-EM data for influenza A and B virus strains and SARS-CoV-2 inactivated with beta-propiolactone are presented. Image analysis allows: (1) to distinguish “empty” viral particles from “full” ones (containing nucleocapsid); (2) to visualize the lipid bilayer of the viral envelope; (3) identify influenza virus surface antigens and the M1 protein layer combined with the inner lipid monolayer; (4) distinguish different morphology of S-spikes on the surface of inactivated SARS-CoV-2 virions. The developed approach provides good image quality for both fundamental and applied research.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"16 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139166332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheological behavior of polysaccharide hydrogels of alginate reinforced by small amount of halloysite nanotubes for extrusion 3D printing","authors":"V. Molchanov, S. A. Glukhova, O. Philippova","doi":"10.55959/doi.org/10.55959/msu0137-0952-16-78-3s-11","DOIUrl":"https://doi.org/10.55959/doi.org/10.55959/msu0137-0952-16-78-3s-11","url":null,"abstract":"The rheological properties of hydrogels of a natural polysaccharide sodium alginate and small amount of clay nanotubes of halloysite were investigated. Changes of rheological properties during the transition from a semi-dilute polymer solution to a hydrogel upon cross-linking by calcium ions were shown. In the gel state, the samples have a yield stress, and their viscosity decreases with the shear rate, but the properties are quickly recovered after the load removal. It was obtained that the addition of up to 0.3 vol.% nanotubes of natural clay halloysite leads to an increase by several times of a storage modulus and an yield stress of the hydrogels. At the same time, the practically important properties of shear thinning and the rapid recovery of properties after the load removing make the nanocomposite hydrogels of alginate and halloysite nanotubes promising for use as ink for extrusion 3D printing.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"11 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139167162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryoconveyor protocols in correlation light and electron microscopy: From multilevel imaging to modeling of biophysical effects and “cryotheranostics”","authors":"O. Gradov","doi":"10.55959/doi.org/10.55959/msu0137-0952-16-78-3s-10","DOIUrl":"https://doi.org/10.55959/doi.org/10.55959/msu0137-0952-16-78-3s-10","url":null,"abstract":"This paper is a technical and methodological note, the purpose of which is to introduce into the practice of biological research methods of cryomicroscopy in a conveyor mode, starting from small magnifications and ending with the limits of magnification/resolution of scanning electron cryomicroscopy. The protocol described can be applied to the samples with low sample preparation complexity without ultratomy or the sample processing typical for transmission electron microscopy methods. According to this protocol samples are analyzed in a single microcuvette (chip) indexed by laboratory information management system and sequentially moved from the non-destructive low-resolution optical microscopy instruments (such as lensless cryomicroscopes) and optical super-resolution methods (some microinterferometers and MIMs with cryotables) to the CryoSEM/CryoESEM level (in programmable environments and atmospheres). Methods of correlation lensless cryomicroscopy and scanning microscopy (including those with the subsequent transition to microanalysis) were introduced; CryoCUVEM and CryoCIREM methods in the ultraviolet and infrared range, respectively; microinterferometry methods using a multi-beam reflected light interferometer (based on the MII-11 platform with several changes); the development of CryoCDICEM systems based on the optical path of an inverted metallographic microscope with a DIC attachment and a LED emitter was also initiated. The advantages of cryoconveyor analysis protocols are ensuring the sample safety in a single cuvette-chip and the possibility of establishing spatial colocalization between the data of optical and electron microscopy (including in the CLEM/CryoCLEM mode), as well as providing a comprehensive non- destructive sample analysis in the sequential study of the microscopic systems with the possibility of varying the subsequent stages of high-resolution microscopy, depending on the results obtained at the previous stages of lower resolution microscopic studies.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"10 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139166352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryo-EM structure of bovine chaperonin TRiC/CCT in open conformation","authors":"T. Stanishneva-Konovalova, E.B. Pichkur, S. Kudryavtseva, I. Yaroshevich, A.N. Semenov, E.G. Maksimov, A. V. Moiseenko, O.I. Volokh, V.I. Muronetz","doi":"10.55959/10.55959/msu0137-0952-16-78-3s-7","DOIUrl":"https://doi.org/10.55959/10.55959/msu0137-0952-16-78-3s-7","url":null,"abstract":"In this work, conditions were selected for obtaining a sample of eukaryotic chaperonin TRiC suitable for studying by cryo-electron microscopy. Using the method of differential scanning (time-resolved) fluorimetry, the temperature stability of protein samples at different concentrations of salt and glycerol was compared, and then the selected conditions were used to prepare the sample for microscopy. As a result, the structure of bovine TRiC in an open conformation was obtained at 4.42 Å resolution.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"56 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139167967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of neurotransmitters on microalgae: conceptual and practical implications","authors":"A. Oleskin, Boyang Cao","doi":"10.55959/msu0137-0952-16-78-3-10","DOIUrl":"https://doi.org/10.55959/msu0137-0952-16-78-3-10","url":null,"abstract":"Apart from their functions in the nervous system of animals, neurotransmitters operate as regulatory agents and signals in diverse kingdoms of life. Many neurotransmitters at low concentrations exert specific effects on microalgae, predominantly functioning as algal growth stimulators. Neurotransmitters that promote microalgal biomass accumulation and enhance the synthesis of lipids, polysaccharides, and other valuable products are of much potential biotechnological interest in terms of projects aimed at producing “algal” drugs and food additives, as well as biodiesel and other kinds of biofuel. Some microalgal species synthesize their own neurotransmitters and/or facilitate their synthesis by the symbiotic microbiota in the gastro-intestinal tract and, therefore, are expected to promote human physical and mental health. Microalgae can exert neuroprotective effects; nevertheless, many microalgae produce toxins affecting the functioning of the nervous system.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139254085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the state of the blood-retinal barrier during the development of signs of age-related macular degeneration in OXYS rats","authors":"D. V. Telegina, D. Peunov, T.A. Kozlova, N. Kolosova, O. Kozhevnikova","doi":"10.55959/msu0137-0952-16-78-3-8","DOIUrl":"https://doi.org/10.55959/msu0137-0952-16-78-3-8","url":null,"abstract":"Age-related macular degeneration (AMD) is a multifactorial neurodegenerative disease that is becoming the leading cause of irreversible vision loss in people over 55 years of age. The development of the wet form of AMD is associated with impaired permeability of the blood- retinal barrier (BRB). It was believed that the BRB does not change in the dry form of the disease, but recently it was shown that dysfunction of the BRB may also contribute to its development; however, information about the state of the BRB at different stages of AMD, especially preclinical ones, is limited. The purpose of this study was to assess the possible contribution of changes in BRB permeability to the development of signs of AMD in OXYS rats, a model of the dry form of the disease. During the period when clinical signs of AMD in OXYS rats are absent (age 20 days), during their manifestation (~5 months) and progression (at 12 and 18 months), the permeability of the BRB for Evans blue dye and the retinal contents of the tight junction proteins occludin, claudin-5, and zonula occludens-1 (ZO-1) were assessed. Wistar rats of the same age served as controls. In OXYS rats, a decrease in the permeability of the BRB was detected, which may result in a violation of the trophic supply of the retina, as well as an increase in the level of occludin during the progression of signs of AMD. ZO-1 level decreased with age, but no interstrain differences were detected. Analysis of retinal transcriptomes (RNA-seq data) showed that in rats of both strains changes in the expression of genes included (according to KEGG) in the category of tight junctions are maximum in the period from 20 days to 3 months. In OXYS rats, the mRNA levels of the Dlg1, Cd1d1, Map3k5 and Arhgef2 genes at the age of 3 months and the Crb3, F11r, Cgn, Cd1d1 and Rap2c genes the age of 18 months are different compared to Wistar rats. Such changes in gene expression in the retina of OXYS rats as AMD signs develop indicate the activation of compensatory mechanisms.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139251156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why freshwater hydra does not get Alzheimer’s disease","authors":"A. N. Khokhlov","doi":"10.55959/msu0137-0952-16-78-3-3","DOIUrl":"https://doi.org/10.55959/msu0137-0952-16-78-3-3","url":null,"abstract":"The history of research into the basic mechanisms of the pathogenesis of Alzheimer’s disease (AD) is briefly considered. Concepts are analyzed in which a decisive role in the development of this disease was attributed to aluminum or free radicals. The lack of reliable data to date to support these concepts is emphasized. The point of view of the author is presented, according to which almost all the results indicating the feasibility of using antioxidants (as well as other potential drugs for AD) for the prevention and treatment of AD were obtained on model animals with certain pathologies (for example, with severe oxidative stress), which contribute to the formation of symptoms similar to those of AD in humans. In this regard, parallels are drawn with experimental gerontological research aimed at studying the effect of a calorie-restricted diet on aging and life span. It is noted that in these studies, animals were used that were either not completely normal or were in unfavorable conditions. According to the author, the lack of significant progress in the development of effective geroprotectors or drugs for the prevention/ treatment of AD is due to the fact that most specialists ignore the principles of classical gerontology, in particular, the definitions of aging and age-related diseases, as well as the correct approaches to the selection of control objects for their studies. It is emphasized that humans, unfortunately, cannot use the freshwater hydra method to combat aging and age-related diseases. Under certain conditions, it continuously renews all cells (including nerve ones) of its body and thereby ensures its “immortality.” In humans, the replacement of “old” neurons can lead to the loss of personality/individuality, and the “repair” of these cells today seems impossible. In this regard, the author considers it expedient to study the aging of postmitotic cells in experiments on stationary cell cultures, which can accelerate, in particular, the deciphering of the mechanisms of accumulation of beta-amyloid and senile pigments such as lipofuscin in neurons. The need for clinical studies of AD is noted as complementary to experimental work, although the first ones are much more expensive and time-consuming. Only confirmation in human studies of the effectiveness of drugs developed in experiments on model animals will allow them to be recommended for use in the clinical practice.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"71 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The sensitivity of multipotent mesenchymal stromal cells to short-term hypoxic stress in vitro depends on the efficiency of homotypic communication through gap junctions","authors":"M. Ezdakova, D. Matveeva, I. Andrianova, E.R. Andreeva","doi":"10.55959/msu0137-0952-16-78-3-7","DOIUrl":"https://doi.org/10.55959/msu0137-0952-16-78-3-7","url":null,"abstract":"Gap junctions (GJ) provide metabolic cooperation between cells through the direct exchange of cytoplasmic components. We analyzed the effect of short-term hypoxic stress on the efficiency of communication through the GJs in cultured multipotent mesenchymal stromal cells (MSCs) and characterized the sensitivity of MSCs to short-term hypoxic stress depending on the GJ function. Mitotically inactive MSCs were used in the experiments, in which the GJs were blocked with a specific inhibitor – carbenoxolone. The MSCs were continuously cultured at 20% O2. Further, MSCs with blocked and working GJs were subjected to hypoxic stress (0.1%, 24 hours). The efficiency of GJ communication was attenuated under hypoxic stress. The combined action of GJ inhibition and hypoxic stress was accompanied by an increase in ROS level as compared to the MSCs after hypoxic stress only. MSCs with blocked GJs were less sensitive to short-term hypoxic stress in comparison with MSCs integrated into the common network through working GJs. It was manifested in attenuation of hypoxia-induced angiogenic activity of MSCs. The angiogenic effects of conditioned medium from the MSCs with blocked GJs were almost twice less, which seems to be related to differences in the angiogenic mediators’ profiles: VEGF level decreased and FGF-2 level increased, while the monocyte chemoattractant protein 3 (MCP-3) level was unchanged. Thus, a decrease in the efficiency of direct MSCs- MSCs communication had a negative effect on mostly requested MSCs activity – the ability to induce angiogenesis. We conclude that blocking of GJ communication in MSCs is a negative event that impairs the coordination of MSCs’ response to the microenvironmental factors, in particular hypoxic stress, and reduces their functional plasticity.","PeriodicalId":334823,"journal":{"name":"Vestnik Moskovskogo universiteta. Seria 16. Biologia","volume":"48 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}