Сравнительный анализ протеомного профиля кератиноцитов HaCaT с использованием 1DE-гель концентрирования

Using tandem mass spectrometry with electrospray ionization, a comparative analysis of HaCaT keratinocyte proteins was carried out before and after exposure of cells to sodium dodecyl sulfate (25 mg/ml) for 48 hours; proteins encoded by human chromosome 18 genes were chosen as the comparison proteins. A total of 2418 proteins were detected in the HaCaT immortalized human keratinocytes, 70% of these proteins were identified by two or more unique peptides. Panoramic mass spectrometry analysis identified 38 proteins encoded by chromosome 18 genes, 27 proteins were common to control HaCaT cells and HaCaT cells exposed to SDS. Using the Metascape database (https://metascape.org), an enrichment analysis of GO terms of the Biological Process category of chromosome 18 gene encoded proteins of HaCaT keratinocytes was performed before and after the SDS exposure. The SDS exposure resulted in a slight enrichment of the GO term "response to stimulus" (GO:0050896) and the related GO term "negative regulation of biological process" (GO:0048519). We found decreased expression levels of membrane proteins encoded by chromosome 18 genes related to cell-cell adhesion (GO:0098609), such as DSC1, DSC3, and DSG1. A decrease in the expression level of desmosomal cadherins is characteristic of malignant neoplasms developing from epithelial tissue cells of various internal organs, mucous membranes, and skin. The method of preparation of HaCaT keratinocyte samples used in this work increased the sensitivity of proteomic analysis of cell culture and made it possible to identify twice as many proteins in one gel strip as compared to the number of proteins (1284) in HaCaT samples subjected to osmotic shock and cleavage by trypsin in solution.Проведена оценка протокола пробоподготовки образцов клеточной культуры кератиноцитов, основанного на солюбилизации белков в присутствии 0.2% додецилсульфата натрия (SDS), процедуре 1DE-гель концентрирования (SDS-PAGE без фракционирования в разделяющем геле) и расщеплении трипсином в геле для углубленного протеомного анализа кератиноцитов НаСаТ в одной полосе белка. С помощью тандемной масс-спектрометрии с электроспрейной ионизацией (LC-MS/MS) проведен сравнительный анализ белков кератиноцитов НаСаТ до и после воздействия SDS в субтоксической дозе (25 мг/мл) в течение 48 ч. В качестве белков сравнения выбраны белки, кодируемые генами хромосомы 18 человека. Всего в иммортализованных кератиноцитах человека линии НаСаТ обнаружено 2418 белков, из них около 70% идентифицировано по двум и более уникальным пептидам. По результатам панорамного масс-спектрометрического анализа удалось идентифицировать 38 белков, кодируемых генами хромосомы 18; из них 27 белков были общими для контрольных клеток и клеток НаСаТ, подвергнутых воздействию SDS. С использованием базы данных Metascape был проведен анализ обогащения терминами онтологии генов (GO) категории биологические процессы (biological process) белков хромосомы 18 кератиноцитов НаСаТ до и после воздействия SDS. Обработка клеточной культуры SDS приводила к незначительному обогащению GO термина “ответ на стимул” (GO:0050896 - response to stimulus) и связанного с ним GO термина “негативная регуляция биологических процессов” (GO:0048519 - negative regulation of biological process). Было обнаружено снижение уровня экспрессии мембранных белков, кодируемых генами хромосомы 18, относящихся к межклеточной адгезии (GO:0098609 - cell-cell adhesion), таких как DSC1, DSC3 и DSG1. Снижение уровня экспрессии десмосомальных кадгеринов характерно для злокачественных новообразований, развивающихся из клеток эпителиальной ткани различных внутренних органов, слизистых оболочек, кожи. Примененный в работе способ подготовки образцов кератиноцитов НаСаТ позволил идентифицировать в одной полосе геля в два раза больше белков по сравнению с образцами НаСаТ, подвергнутыми осмотическому шоку и расщеплению трипсином в растворе

Comparative Study of Methanogenic Pathways in the Sediments of Thermokarst and Polygenetic Yamal Lakes

Comparative study of methanogen diversity and potential activity of different methanogenic pathways in the sediments of young thermokarst and mature polygenetic Yamal lakes was carried out. The hydrogenotrophic pathway of methanogenesis played an important role in methane formation in thermokarst lakes. The acetoclastic and methylotrophic pathways were also revealed there. In a polygenetic lake with a dissolved organic matter content closest to that of the thermokarst lakes, methanogenesis proceeded more intensively, and the relative abundance of methanogens, especially acetoclastic ones, was higher than in thermokarst lakes. The activity of methyl-reducing methanogens was also assumed there. Methanogens of the genera Methanothrix and Methanoregula, as well as representatives of the family Methanomassiliicoccaceae were identified in the sediments of all lakes. Methane-oxidizing bacteria (Methylobacter, Candidatus "Methylomirabilis") and archaea (Ca. "Methanoperedens") were also detected

On the Possibility of Aerobic Methane Production by Pelagic Microbial Communities of the Laptev Sea

The taxonomic diversity and metabolic activity of microbial communities in the Laptev Sea water column above and outside the methane seep field were studied. The concentrations of dissolved methane in the water column at both stations were comparable until the depth of the pycnocline (25 m). At this depth, local methane maxima were recorded, with the highest concentration (116 nM CH4) found at the station outside the methane seep field. Results of the 16S rRNA gene sequencing and measurements of the rates of hydrogenotrophic methanogenesis indicated the absence of methanogenesis caused by the methanogenic archaea in the pycnocline and in other horizons of the water column. The 16S rRNA-based analysis of microbial phylogenetic diversity, as well as radiotracer analysis of the rates of primary production (PP), dark CO2 assimilation (DCA), and methane oxidation (MO), indicated the functioning of a diverse community of pelagic microorganisms capable of transforming a wide range of organic compounds under oligotrophic conditions of the Arctic basin. Hydrochemical prerequisites and possible microbial agents of aerobic methane production via demethylation of methylphosphonate and decomposition of dimethylsulfoniopropionate using dissolved organic matter synthesized in the PP, DCA, and MO processes are discussed