Morphological and transcriptional heterogeneity of microglia in the normal adult mouse brain

Ziel dieser Doktorarbeit ist eine umfassende Untersuchung der Heterogenität von Mikroglia aus morphologischer, elektrophysiologischer und transkriptioneller Perspektive mit dem Schwerpunkt auf Unterschiede zwischen weißer und grauer Substanz. Im ersten Kapitel diskutiere ich die morphologische Heterogenität von Mikroglia mit dem Fokus auf Satelliten- und Parenchymale-Mikroglia. Wir führten eine eingehende Analyse mehrerer Hirnareale durch und quantifizierten die Anzahl der Satellitenmikroglia, die mit verschiedenen neuronalen Subtypen in Kontakt stehen. Wir fanden heraus, dass die Anzahl der Satellitenmikroglia stark mit der neuronalen Dichte eines bestimmten Bereichs korreliert. Im zweiten Kapitel dieser Arbeit untersuche ich die transkriptionelle Heterogenität von Mikroglia aus weißer und grauer Substanz, wobei ich die in Gliazellen neu etablierte Patch-seq-Methode anwende. Diese Methode ermöglicht es eine Kombination aus morphologischen, lektrophysiologischen und transkriptionellen Profilen einzelner Zellen zu erhalten, die es erlauben, zelluläre Unterschiede zu charakterisieren. Wir identifizieren einen zellulären Subtyp, wenn wir den Patch-seq-Datensatz mit FACS-basierter Einzelzell-RNA-seq-Datensätzen vergleichen. Dieser Subtyp gehört eindeutig zu dissoziierten Gewebeproben und ist durch die Expression von Stress-assoziierten Genen charakterisiert. Im dritten Kapitel wende ich mich der Frage zu, wie Transkripte mittels SLAM-seq nachverfolgt werden können, die während der Dissoziation des Gewebes entstehen. Das Verfahren ermöglicht es mRNA, die während der Dissoziation der Probe entsteht, metabolisch zu markieren, rechnerisch zu identifizieren und zu entfernen. Indem wir die markierten Transkripte aus dem Mikroglia “entfernen”, beobachten wir, dass ein „aktivierter Mikroglia“-Subtyp zur allgemeinen Mikroglia-Population gehört.The aim of this doctoral work is to provide a comprehensive study and overview on the topic of the heterogeneity of microglia in the normal adult mouse brain from the morphological, electrophysiological and transcriptional perspective with the focus on differences between white and grey matters. In the first Chapter, I discuss the morphological heterogeneity of microglia in the brain with the focus on two morphologically distinct classes: satellite and parenchymal microglia. We performed an in-depth analysis of multiple brain areas and quantified the number of satellite microglia which is in contact with different neuronal subtypes. We found that satellite microglia numbers are highly correlated with neuronal densities of a certain area, while showing no preferences for any of the neuronal types. In Chapter two of this work, I study transcriptional heterogeneity of microglia from white and grey matters. For this I am employing Patch-seq, which we newly established in glial cells. This method allows a combination of morphological, electrophysiological and transcriptional profiles of single cells to assess their differences. When comparing Patch-seq dataset to the previously published FACS isolated single cell RNA-seq microglia datasets, we find a subtype of cells which uniquely belongs to FACS sample and is characterized by expression of stress-associated genes. This finding points out to the fact of dissociation-related artifacts in the single cell RNA-seq data which are not present in situ. In the third chapter, I identified transcripts which are induced during the dissociation of the tissue by employing the SLAM-seq method. This procedure allows to metabolically label newly transcribed mRNA and computationally remove transcripts from the sample. By removing the labeled transcripts from the dataset of cells isolated from the hippocampus via enzymatic dissociation, we observe that an “activated microglia” subtype merges with the general microglia population

Novel of core-shell AlOOH/Cu nanostructures: Synthesis, characterization, antimicrobial activity and in vitro toxicity in Neuro-2a cells

Core-shell micro/nanostructures were fabricated by the reaction of Al/Cu bimetallic nanoparticles with water. Al/Cu nanoparticles have been obtained using the method of simultaneous electrical explosion of a pair of the corresponding metal wires in an argon atmosphere. The nanoparticles are chemically active and interact with water at 60°C to form core-shell micro/nanostructures. The obtained products were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering and the nitrogen adsorption method. The antibacterial activity of the synthesized structures was investigated against E. coli and St. aureus. The toxic effect of these nanostructures against the Neuro-2a neuroblastoma cell line was investigated. AlOOH/Cu nanostructures are shown to inhibit cell proliferation. The AlOOH/Cu nanostructures are good candidates for medical applications

Synthesis of low-size flower-like AlOOH structures

Al/Cu, Al/Zn, and Al/Fe bimetallic nanoparticles have been obtained using the method of simultaneous electrical explosion of metal pairs in an argon atmosphere. The nanoparticles are chemically active and interact with water at 60°C forming flower-like hierarchical porous structures with a high specific surface area. As the Al/Cu nanopowder is oxidized with water, flower-like pseudoboehmite composite structures are formed with the size of under 1.0 [mu]m; structurally heterogeneous electron-dense spherical inclusions of unreacted metal copper and intermetallides are identified inside them. Al/Fe product transformations are presented by the flower-like pseudoboehmite surrounded by lamellar structures enriched with ferric oxides. Al/Zn nanoparticles react with water, forming the flower-like pseudoboehmite and mainly hexagonal zinc oxide laminae. The composite particles obtained can be used as antibacterial agents in manufacturing medical supplies

SOCIO-PSYCHOLOGICAL SPACE OF KOMSOMOLSK-ON-AMUR AMONG YOUNG PEOPLE WITH DIFFERENT MIGRATION INTENTIONS

Тема, цель работы. Основной темой нашего исследования выступали особенности эмоционального отношения к людям, объектам и явлениям социально-психологического пространства города г. Комсомольска-на-Амуре у молодежи с разными миграционными намерениями.Метод и методологию проведения работы. В исследовании приняли участие 130 жителей города в возрасте 16–25 лет, разделенные на три группы: не собирающиеся менять место жительства, намеренные уехать из города при первой возможности и допускающие возможность переезда при определенных условиях. Для оценки эмоционального отношения к различным объектам социально-психологического пространства и изучения его структуры респондентам был предложен проективный модифицированный психогеометрический тест С. Деллингер. Исследование выстроено по типу репертуарной решетки, объектами оценки для респондентов выступали различные структурные компоненты социально-психологического пространства: коммуникативная сфера, возможности профессиональной и личностной самореализации, временные перспективы и территориальная идентичность испытуемых.Результаты и выводы. Анализ результатов показал, что молодежь с выраженными миграционными намерениями более негативно относится к Дальневосточному региону, его населению и своей настоящей жизни. Данная группа молодежи пространство города рассматривает как неэффективное для самореализации и саморазвития в настоящем и будущем и не идентифицирует себя с территорией проживания. Молодежь, которая хочет остаться в городе, рассматривает его как эффективное пространство для самореализации и саморазвития, имеет сформированную территориальную идентичность, позитивно относится к своей настоящей жизни, месту проживания и населению города.Область применения результатов. Результаты исследования могут быть применены в сфере проектирования социальной инфраструктуры, планирования молодежной и миграционной политики при реализации «Стратегии социально-экономического развития муниципального образования городского округа «Город Комсомольск-на-Амуре» до 2032 года».The article presents a research of the structure of the socio-psychological space of Komsomolsk-on-Amur among young people with different migration intentions. 130 16–25 year-old residents from Komsomolsk-on-Amur took part in this research. They were divided into three groups: those who were going to change their place of residence, those who intended to leave the city at the first opportunity and those who allowed for the possibility of moving under certain conditions.To assess attitude of young people toward different socio-psychological space and to study its structure, a projective modified psychological geometric test by S. Dellinger was used. The study is presented in the form of a repertory grid. The objects of assessment for the respondents were various aspects of the socio-psychological space, which characterized its communicative sphere, possibility of professional and personal self-realization, temporarily prospects and territorial identity of the subjects.The analysis of the results showed that young people with certain migration intentions had more negative attitude to the Far East region, its population and their own real life. This group of young people considers the space of the city as inefficient for self-realization and self-development in the present and future and does not identify itself with the territory of residence.Young people who want to stay in the city, consider it as an effective space for self-realization and self-development. They have a formed territorial identity, positive attitude to their real life, to the place of residence and the population of the city.The results of the research can be applied in the field of youth policy design

Formation and antibacterial activity of AlOOH/Ag composite coating on macroporous α-Al2O3 ceramics

In this study, the modification of macroporous α-Al2O3 ceramics with AlOOH nanostructures impregnated with silver particles is carried out using bicomponent Al/Ag nanoparticles obtained by the simultaneous electrical explosion of Al and Ag wires. Nanoparticle suspension impregnation of porous ceramics followed by oxidation with water is shown to lead to the formation of a continuous AlOOH nanosheet coating on the ceramic surface, with silver releasing on the surface of nanosheets in the form of individual particles sized 5–30 nm. Modified with AlOOH/Ag nanostructures, macroporous α-Al2O3 pellets with a diameter of 11 mm and a thickness of 5 mm show 100% efficiency for water purification from bacteria with a concentration of 105 CFU/mL for 7.5 min at a flow rate of 6.7 mL/min

Preparation of nano/micro bimodal aluminum powder by electrical explosion of wires

Electrical explosion of aluminum wires has been shown to be a versatile method for the preparation of bimodal nano/micro powders. The energy input into the wire has been found to determine the relative content of fine and coarse particles in bimodal aluminum powders. The use of aluminum bimodal powders has been shown to be promising for the development of high flowability feedstocks for metal injection molding and material extrusion additive manufacturing

In situ Patch-seq analysis of microglia reveals a lack of stress genes as found in FACS-isolated microglia

We applied the patch-seq technique to harvest transcripts from individual microglial cells from cortex, hippocampus and corpus callosum of acute brain slices from adult mice. After recording membrane currents with the patch-clamp technique, the cytoplasm was collected via the pipette and underwent adapted SMART-seq2 preparation with subsequent sequencing. On average, 4138 genes were detected in 113 cells from hippocampus, corpus callosum and cortex, including microglia markers such as Tmem119, P2ry12 and Siglec-H. Comparing our dataset to previously published single cell mRNA sequencing data from FACS-isolated microglia indicated that two clusters of cells were absent in our patch-seq dataset. Pathway analysis of marker genes in FACS-specific clusters revealed association with microglial activation and stress response. This indicates that under normal conditions microglia in situ lack transcripts associated with a stress-response, and that the microglia-isolation procedure by mechanical dissociation and FACS triggers the expression of genes related to activation and stress

Investigation of the peculiarities of oxidation of Ti/Al nanoparticles on heating to obtain TiO2/Al2O3 composite nanoparticles

The creation of new nanomaterials with improved characteristics, as well as the development of new approaches to obtain such materials is an urgent task in science and technology. One of the promising directions in obtaining improved nanomaterials is the use of precursors in the form of multicomponent metal nanoparticles. Thermal oxidation of bimetallic Ti/ Al nanoparticles obtained by electrical explosion of wires was investigated in this work. Ti/Al nanoparticles have been found to be completely oxidized with the formation of composite TiO2/ Al2O3 nanoparticles after calcination at 900 °C. The formation of TiO2 phase with a rutile structure on heating to 500 °C, and the formation of TiO2 phases with a rutile and anatase structure, as well as α-Al2O3 on heating to 700 °C have been established, in addition to the residue of unoxidized metals. Complete oxidation of Ti/Al nanoparticles occurs when heated to 900 °C. The photochemical activity of TiO2/ Al2O3 composite nanoparticles obtained at 900 °C was studied. The degradation of methyl orange dye reached 55% under UV irradiation for 120 min

Toxicity of the hybrid material based on low-dimensional structures of aluminum oxide

Aluminum oxides of various morphology and phase composition, including pseudoboehmite, have wide application in medicine. The novel hybrid material from polymer fibers and low-dimensional structures of pseudoboehmite fixed on them can be used as a wound dressing due to its highly absorbent and adsorbent properties. The in vivo investigation of acute and chronic toxicity of the novel hybrid material after a single dermal application in the acute experiment for 8 and 24 hours with outbred male and female rats reveals no irritation or other pathological changes. The chronic toxicity testing of the material after multiple dermal applications at two doses causes no death of animals and no pathological changes in their general condition, weight dynamics, and visceral morphology. The macro- and microscopy of internal organs shows no pathological changes as compared to control animals. The results obtained bear witness to the low potential risk of toxicity when using the hybrid material as a wound dressing

Antibacterial properties of PMMA functionalized with CuFe2O4/Cu2O/CuO nanoparticles

We have prepared a composite thin coating by incorporation of CuFe2O4/Cu2O/CuO nanoparticles in polymethyl methacrylate (PMMA) matrix by using the solution casting method. The electrical explosion of two twisted wires (EETW) was used to obtain multicomponent CuFe2O4/Cu2O/CuO nanoparticles with an average particle size of 20–70 nm. The microscopic studies showed that the nanoparticles in the composite coatings are evenly distributed. However, nanoparticles are strongly agglomerated as the powder concentration in the coating increases to 5 wt.% and 10 wt.%, as the size of particle agglomerates increases to 50 and 100 µm, respectively. Therefore, nanoparticles were pre-treated with ultrasound when introduced into the PMMA matrix. The thermal stability of the composite coating does not change with the introduction of CuFe2O4/Cu2O/CuO nanoparticles in the amount of 5 wt.%. The inclusion of nanoparticles in the PMMA matrix significantly enhances its antibacterial activity. The addition of 5 wt.% nanoparticles inhibited the growth of E. coli by 100% and the growth of MRSA by 99.94% compared to pure PMMA already after 3 h of exposure of bacteria on the surface of the composites. This research provides an easy-to-manufacture and cost-efficient method for producing a uFe2O4/Cu2O/CuO/PMMA composite coating with a broad application as an antibacterial material