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Фокичев Николай Сергеевич

Факультет биологии и биотехнологии

Профиль на hse.ru ↗ тел.: 15476
Публикаций
7
Языков
2
Наград
2
Конференций
0
Профиль Публикации (7) Курсы (8)

Профессиональные интересы

Тромботерапияпротеиназы микромицетовбиотехнологиябиоэкономикаохрана интеллектуальной собственности

Должности

  • Доцент — Факультет биологии и биотехнологии, Базовая кафедра Института биоорганической химии им. академиков М.М. Шемякина и Ю.А. Овчинникова РАН

Био

  • · Начал работать в НИУ ВШЭ в 2023 году.

Образование

  • 2023 · Кандидат биологических наук
  • 2015 · Специалитет: Московский государственный университет им. М.В. Ломоносова, специальность «Биохимия», квалификация «Биохимик»
  • — · Магистратура: Московский государственный университет им. М.В. Ломоносова 2017 "Биоинженерия, биотехнология и биоэкономика", магистр по направлению "Биология" Аспирантура: Московский государственный университет им. М.В. Ломоносова 2021 "Биотехнология", преподаватель-исследователь
  • — · Кандидат биологических наук, 2023, специальность "биотехнология"

Опыт работы

  • · 2015 - 2018: МГУ им. М.В. Ломоносова
  • · 2018 - 2022: ЗАО "Биокад"
  • · 2022 - 2023: ГК "Промомед"
  • · 2023 - н.в.: ООО "Биннофарм Групп"

Награды и поощрения

  • · Надбавка за публикацию в журнале из Списка А (и приравненном к нему научном издании) (2025–2026)
  • · Лучший преподаватель — 2024–2025

Идентификаторы исследователя

Публикации (7)

Microplastic effects on mouse colon in normal and colitis conditions: A literature review

2025 · ARTICLE · en

Background: Taking into account the global spread of microplastic (MP) pollution, the problem of the MP impact on human health is relevant. MP enters the organism predominantly with water and food, and is mostly detected in the large intestine. Therefore, the connection between MP pollution and the increase in colitis is an important question. In order to assess the toxic and pathogenetic effects of MP, experimental studies were actively conducted during recent years, mainly on laboratory mice. Objectives: The aim of our review was to summarize and systematize the data on the MP effect on mice colon under normal conditions and during colitis in order to assess the role of MP in the development of intestinal diseases. This manuscript could be relevant for ecologists, experimental biologists, and physicians dealing with problems related to anthropogenic environmental changes and inflammatory bowel diseases. Survey methodology: The search was conducted based on PubMed data about original experimental studies of the MP effects on the colon of healthy mice and mice with colitis. Results: In healthy mice colon, MP can cause oxidative stress, increased permeability, immune cell infiltration, production of proinflammatory factors, and decreased mucus production. MP affects proliferation, apoptosis, and differentiation of epithelial cells, expression of tight junction components and glycocalyx, membrane transport, signaling pathways, metabolome, and intestinal microflora composition. In mice with acute and chronic experimental colitis, MP consumption leads to a more pronounced pathological process course. Conclusions: MP may be one of the factors contributing to the development of colitis in humans. However, further research is needed.

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Morphofunctional changes in the immune system in colitis-associated colorectal cancer in tolerant and susceptible to hypoxia mice

2025 · ARTICLE · en

Background: One of the effective strategies for the treatment of tumor diseases, including colitis-associated colorectal cancer (CAC), is immunotherapy. During inflammation, NF-κB is activated, which is connected with the hypoxia-inducible factor-HIF, regulating the immune cells functioning and influences the CAC development. Organisms differ according to their hypoxia resistance and HIF expression. Therefore, the aim of the study was to characterize the thymus, spleen and mesenteric lymph nodes morphofunctional features, as well as changes in the subpopulation composition of peripheral blood cells and mesenteric lymph nodes in tolerant and susceptible to hypoxia C57Bl/6 mice in CAC. Methods: Hypoxia tolerance was assessed by gasping time measurement in hypobaric decompression chamber. Based on the outcome, the mice were assigned to three groups characterized as 'tolerant to hypoxia', 'normal', and 'susceptible to hypoxia'. A month after determining hypoxia resistance CAC was modeled by intraperitoneal azoxymethane (AOM) administration and three cycles of dextran sulfate sodium consumption. Mice were sacrificed on the 141st day after the AOM administration, a morphological, morphometric and immunohistochemical study of tumors, morphological and morphometric study of thymus and spleen, and subpopulation composition of peripheral blood cells and mesenteric lymph nodes assessment were carried out. Results: Tumors in tolerant and susceptible to hypoxia mice were represented by glandular intraepithelial neoplasia and adenocarcinomas, the area of which was larger in susceptible mice. Immunohistochemical study revealed a more pronounced Ki-67+ staining in tumors of susceptible mice. In CAC, only in tolerant mice, expansion of the thymic cortex was observed relative to the control group, while in susceptible ones, no changes were detected. Only in susceptible to hypoxia mice, spleen germinal centers of lymphoid follicles enlargement were observed. Only in susceptible mice during CAC, in comparison to the control group, the relative and absolute number of B-lymphocytes and relative-cytotoxic T-lymphocytes in blood increased. The relative cytotoxic T-lymphocytes and NK cells number in peripheral blood during CAC was higher in susceptible to hypoxia mice compared to tolerant ones. In susceptible to hypoxia mice, more pronounced changes in the mesenteric lymph nodes subpopulation composition of cells were revealed-only in them the absolute and relative number of B-lymphocytes and NK cells, the absolute number of cytotoxic T-lymphocytes increased, and the relative number of macrophages decreased. Conclusions: Morphofunctional differences in the thymus, spleen, mesenteric lymph nodes and blood immune cells reactions indicated the more pronounced immune response to the CAC development in susceptible to hypoxia mice, which should be taken into account in experimental studies.

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Influence of Microplastics on Manifestations of Experimental Chronic Colitis

2025 · ARTICLE · en

Environmental pollution with microplastics (MPs) can have a negative impact on human health. Certain findings point to the relationship between MP and the development of inflammatory bowel diseases (IBD). We investigated the effect of MP consumption on the severity of chronic colitis in male C57BL/6 mice. The MP effect was modeled by drinking water consumption with a suspension of 5 μm PS particles at a concentration of 10 mg/L replacement for 12 weeks. Chronic colitis was induced by three seven-day cycles of 1% DSS consumption (starting from the 8th, 29th and 50th days of the experiment). We investigated inflammatory infiltration, the goblet cell volume fraction and the highly sulfated and neutral mucins content in them, the endocrine cell number, the ulcerative-inflammatory process prevalence, changes in the gene’s expression encoding tight junction proteins, glycocalyx components proapoptotic factor Bax and proliferation marker Mki67 in the colon, and TNFα, IL-1β, IL-6 and IL-10 cytokines content in the serum. In healthy mice, MP did not cause pathological changes in the colon; however, indirect data indicate an increase in colon permeability. In chronic colitis, MP leads to higher prevalence of all pathological changes in general, and ulcers in particular, in a greater number of crypt abscesses and enteroendocrine cells. MP consumption leads to a more severe chronic colitis course.

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Physiological and molecular mechanisms of tolerance to hypoxia and oxygen deficiency resistance markers

2025 · ARTICLE · en

Humans and laboratory animals differ in their resistance to hypoxia, which affects the severity of inflammatory diseases and the rate of tumor progression. Therefore, it is necessary to search for methods for assessing the initial tolerance to oxygen deficiency and the risks of developing acute mountain sickness without direct hypoxia exposure on the organism. The literature describes assessments of oxygen deficiency tolerance assessing based on physiological and molecular parameters. The limitations of such methods include the need of expensive equipment use and highly qualified specialists involvement. In addition, in the studies presented in this review, the altitude, time and methods for achieving it, as well as the frequency of assessing the severity of acute mountain sickness varied significantly. It is necessary to continue research aimed at investigating biomarkers of tolerance to oxygen deficiency without direct hypoxia exposure using instrumental and laboratory diagnostics. This will allow developing new approaches for personalized prevention, diagnosis and treatment of inflammatory diseases and malignancies and, accordingly, improve the quality of life.

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Microplastics’ Impact on the Development of AOM/DSS-Induced Colitis-Associated Colorectal Cancer in Mice

2025 · ARTICLE · en

Recently, evidence indicating that microplastics (MPs) have a hazardous effect on human health is accumulating. The potential of MPs having a role in carcinogenesis was suggested. Therefore, the aim of this study was to evaluate MPs’ effect on colitis-associated colorectal cancer (CAC) development. The AOM/DSS-induced CAC model was reproduced in two groups of adult male C56BL/6 mice. One of these groups received MPs (5 µm polystyrene microbeads) with drinking water at a dose of 1.48 mg/kg/day throughout the experiment (12 weeks), and the other received water untreated with MPs. In the colons of mice that consumed MPs, there was a higher number of tumor nodules at the macroscopic level, a greater tumor prevalence on histological sections, more pronounced inflammatory infiltration, a higher goblet cell volume fraction, the content of highly sulfated mucins was AcademicEditor: Alessandro Mannucci Received: 21October2025 Revised: 21November2025 Accepted: 26November2025 Published: 27 November2025 Citation: Zolotova, N.;Kirillova, M.; Dzhalilova, D.; Tsvetkov, I.; Fokichev, N.; Makarova,O.Microplastics’ ImpactontheDevelopmentof AOM/DSS-Induced Colitis-Associated Colorectal CancerinMice. Int. J. Mol. Sci. 2025, 26, 11511. https://doi.org/ 10.3390/ijms262311511 Copyright: ©2025bytheauthors. Licensee MDPI,Basel,Switzerland. This article is an open access article distributed under the termsand conditions of the Creative Commons Attribution (CC BY)license (https://creativecommons.org/ licenses/by/4.0/). found in them, and there were more tumors with increased enteroendocrine cell content. Wedidnot findanyMPeffects on the claudins, mucins, proapoptotic factor Bax, or on the proliferation marker Mki67 gene expression in the medial colon, nor on the serum level of TNFα, IL-1β, IL-6, and IL-10 cytokines. Thus, MPs promote the CAC development in mice by exacerbating intestinal local inflammation and damaging the epithelial barrier, and MPs mayrepresent a potential environmental cofactor contributing to CAC risk.

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Changes in the Expression of Genes Regulating the Response to Hypoxia, Inflammation, Cell Cycle, Apoptosis, and Epithelial Barrier Functioning during Colitis-Associated Colorectal Cancer Depend on Individual Hypoxia Tolerance

2024 · ARTICLE · en

One of the factors contributing to colorectal cancer (CRC) development is inflammation, which is mostly hypoxia-associated. This study aimed to characterize the morphological and molecular biological features of colon tumors in mice that were tolerant and susceptible to hypoxia based on colitis-associated CRC (CAC). Hypoxia tolerance was assessed through a gasping time evaluation in a decompression chamber. One month later, the animals were experimentally modeled for colitis-associated CRC by intraperitoneal azoxymethane administration and three dextran sulfate sodium consumption cycles. The incidence of tumor development in the distal colon in the susceptible to hypoxia mice was two times higher and all tumors (100%) were represented by adenocarcinomas, while in the tolerant mice, only 14% were adenocarcinomas and 86% were glandular intraepithelial neoplasia. The tumor area assessed on serially stepped sections was statistically significantly higher in the susceptible animals. The number of macrophages, CD3-CD19+, CD3+CD4+, and NK cells in tumors did not differ between animals; however, the number of CD3+CD8+ and vimentin+ cells was higher in the susceptible mice. Changes in the expression of genes regulating the response to hypoxia, inflammation, cell cycle, apoptosis, and epithelial barrier functioning in tumors and the peritumoral area depended on the initial mouse's hypoxia tolerance, which should be taken into account for new CAC diagnostics and treatment approaches development.

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Murine models of colorectal cancer: the azoxymethane (AOM)/dextran sulfate sodium (DSS) model of colitis-associated cancer

2023 · ARTICLE · en

Background Colorectal cancer (CRC) is the third most common cancer. It is a heterogeneous disease, including both hereditary and sporadic types of tumors. CRC results from complex interactions between various genetic and environmental factors. Inflammatory bowel disease is an important risk factor for developing CRC. Despite growing understanding of the CRC biology, preclinical models are still needed to investigate the etiology and pathogenesis of the disease, as well as to find new methods of treatment and prevention. Objectives The purpose of this review is to describe existing murine models of CRC with a focus on the models of colitis-associated CRC. This manuscript could be relevant for experimental biologists and oncologists. Methodology We checked PubMed and Google from 01/2018 to 05/2023 for reviews of CRC models. In addition, we searched PubMed from 01/2022 to 01/2023 for articles using the azoxymethane (AOM)/dextran sulfate sodium (DSS) CRC model. Results Existing murine models of CRC include spontaneous, genetically engineered, transplantation, and chemically induced models. For the study of colitis-associated cancer (CAC), the AOM/DSS model is predominantly used. This model is very similar in histological and molecular characteristics to the human CAC, and is highly reproducible, inexpensive, and easy to use. Despite its popularity, the AOM/DSS model is not standardized, which makes it difficult to analyze and compare data from different studies. Conclusions Each model demonstrates particular advantages and disadvantages, and allows to reproduce different subtypes or aspects of the pathogenesis of CRC.

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Курсы (8)