Barrett’s esophagus (BE) is a premalignant lesion for esophageal adenocarcinoma (EAC). Development of Barrett’s esophagus is caused by biliary reflux that provokes intensive mutagenesis in stem cells of epithelium in distal esophagus and gastro-esophageal junction. Other possible cell origins of Barrett’s esophagus include stem cells of mucosal esophageal glands and their ducts, of stomach, residual embryonic cells and circulating bone marrow stem cells. Classic conception of healing of caustic lesion was replaced by idea of cytokine storm that forms inflammatory microenvironment for phenotypic shift toward intestinal metaplasia of distal esophagus. The review summarizes contemporary concepts of BE and EAC pathogenesis.

Knowledge of the biological effects of molecular hydrogen (H2), hydrogen gas, is constantly expanding giving a reason for optimism for several healthcare practitioners regarding management of multiple diseases, including socially significant ones. However, mechanisms underlying the biological effects of H2 are still being actively argued. In this review, we focus on mast cells as a potential target for H2 at the level of a specific tissue microenvironment. H2 regulates processing of pro-inflammatory components of the mast cell secretome and their entry into the extracellular matrix; this can significantly affect the state of the integrated-buffer metabolic environment and the structure of the immune landscape of the local tissue microenvironment. The analysis performed highlights several potential mechanisms for developing the biological effects of H2 and offers great opportunities for translating the obtained findings into clinical practice.

Kidney fibrosis is a complex polyetiological progressive disease manifesting as an intraorgan proliferation of the connective tissue with the appearance of cicatricial changes. However, pathogenetic mechanisms of renal fibrosis remain poorly understood. The paper highlights features of the protease phenotype and histotopography of mast cells (MCs) found in the kidney, as the key players in extracellular matrix remodeling in nephrofibrosis, detected in a patient diagnosed with "nephrosclerosis with the non-functioning upper pole of the duplex right kidney in the junction of refluxing megaureter of the upper pole of the duplex right kidney". The highest content of MCs was found in the kidney areas with fibrotic changes. MCs were actively involved in the development of inflammatory and fibrotic changes in limited loci of the specific tissue microenvironment of the kidney through targeted secretion of tryptase, chymase, and carboxypeptidase A3 to the vascular endothelium, nephron epithelium, interstitium cells, and components of the intercellular substance. The formation of a profibrotic environment in the kidney interstitium was facilitated by epigenetic effects of tryptase promoting epithelial-mesenchymal transition (EMT) of the nephron epithelium. A selectively increased number and targeted secretory activity of MCs in limited loci of the kidney parenchyma without visible pathological changes evidence a trigger pathogenetic role of specific proteases in the formation of a local microenvironment with a profibrogenic metabolic profile. Thus, MCs are actively involved in the mechanisms of formation and evolution of fibrogenic niches in the kidney; this fact can be used to develop new strategies for therapeutic options of tubulointerstitial fibrosis resulted from chronic kidney injury. Further study of the molecular phenotype of mast cells reveals new fundamental mechanisms of fibrosis pathogenesis being a significant tool for personalized therapy in nephrology.

Development of new techniques of multimodal treatment, diagnostics of various neoplasms and improvement of these techniques can significantly increase the life expectancy of patients with carcinomas of the colon and abdominal cavity organs, since prevention of various side effects of radiation therapy is one of the main problems of oncological care. Electron irradiation is one of the most promising types of radiation therapy. There are no data on proliferation and apoptosis of the colon epithelium after irradiation with electrons, especially in different modes (single and summary). Aim of the study: Morphological evaluation of apoptosis and proliferation of colonic epithelium after local irradiation with electrons at doses 2 Gy and 25 Gy. Materials and methods. Colon fragments from sexually mature Wistar rats (n=50, body weight 200 ± 10 g) were divided into three groups: I - control (n = 10); II - experimental group (n = 20; local single electron irradiation at a dose of 2 Gy), III - experimental group (n=30), local fractional irradiation with electrons at a total dose of 25 Gy. They were studied by light microscopy using hematoxylin and eosin staining and immunohistochemical reactions with antibodies to Ki-67 and Cas3. Morphological disorders were accompanied by increased expression of pro-apoptotic molecules (caspase-3), and the period of regeneration by proliferative marker (Ki-67). Conclusions: Local fractional irradiation of the colon with electrons at a dose of 2 Gy and 25 Gy resulted in minor changes in the epithelium, a decrease in the number of goblet cells, but with preservation of regenerative potential, mild degenerative-dystrophic lesions. Intestinal crypts were damaged, leading to a decrease in Ki-67 and an increase in the number of caspase-3-positive epitheliocytes.

Abstract: Mast cell (MC) specific proteases are of particular interest for space biology and medicine due to their biological activity in regulating targets of a specific tissue microenvironment. MC tryptase and chymase obtain the ability to remodel connective tissue through direct and indirect mechanisms. Yet, MC specific protease expression under space flight conditions has not been adequately investigated. Using immunohistochemical stainings, we analyzed in this study the protease profile of the jejunal, gastric and hepatic MC populations in three groups of Mongolian gerbils - vivarium control, synchronous experiment, and 12-day orbital flight on the Foton-M3 spacecraft, - and in two groups - vivarium control and anti-orthostatic suspension - included in the experiment simulating effects of weightlessness in the ground-based conditions. After a space flight, there was a decreased number of MCs in the studied organs combined with an increased proportion of chymase-positive MCs and MCs with a simultaneous content of tryptase and chymase; the secretion of specific proteases into the extracellular matrix increased. These changes in the expression of proteases were observed both in the mucosal and connective tissue MC subpopulations of the stomach and jejunum. Notably, the relative content of tryptase-positive MCs in the studied organs of the digestive system decreased. Space flight conditions simulated in the synchronous experiment caused no similar significant changes in the protease profile of MC populations. The space flight conditions resulted in an increased chymase expression combined with a decreased total number of protease-positive MCs apparently due to participating in the processes of extracellular matrix remodeling and regulating the state of the cardiovascular system.

The digestive organs are highly sensitive to the influence of orbital flight factors and can limit the professional activities of crew members aboard the International Space Station. Connective tissue as a system-forming matrix of the integrative-buffer metabolic environment is of particular relevance in space biomedicine, ensuring the functioning of internal organs under an altered gravitational stimulus. However, the adaptive mechanisms of the fibrous extracellular matrix of the gastric and intestinal connective tissue have not been fully investigated under prolonged microgravity weightlessness. Using histochemical techniques, the authors experimentally studied the state of collagen fibers in the specific tissue microenvironment of the gastric and intestinal membranes in C57BL/6N mice after a 30-day space flight, subsequent 7-day ground readaptation, and in animals of the relevant control groups. The 30-day stay of laboratory animals aboard the Bion-M 1 biosatellite resulted in a reduction in the fibrous extracellular matrix of connective tissue in the studied digestive organs, excepting the gastric lamina propria. An increased fibrillogenesis was revealed in the gastrointestinal mucous membranes of animals in 7 days after the biosatellite landing, if compared with the parameters of animals of the space flight group. During the experiment with ground simulated orbital flight conditions, changes in collagen fibers were not significant compared to the vivarium control group. Thus, the results obtained evidence gravisensitivity of the fibrous extracellular matrix of the intraorgan connective tissue. This fact also highlights the necessity to further improve gastrointestinal tract-related preventive measures for astronauts during orbital flight.

This review systematically examines the multifaceted relationship between the tumor microenvironment, stromal interactions, and colorectal cancer (CRC) progression and metastasis. The analysis begins by assessing the gut microbiome's influence on CRC development, emphasizing its association with gut-associated lymphoid tissue (GALT). The role of the Wnt signaling pathway in CRC tumor stroma is scrutinized, elucidating its impact on disease progression. Tumor budding, its effect on tumor stroma, and implications for patient prognosis are investigated. The review also identifies conserved oncogenic signatures (COS) within CRC stroma and explores their potential as therapeutic targets. Lastly, the seed and soil hypothesis is employed to contextualize metastasis, accentuating the significance of both tumor cells and the surrounding stroma in metastatic propensity. In summary, this review highlights the intricate interdependence between CRC cells and their microenvironment, providing valuable insights into prospective therapeutic approaches targeting tumor-stroma interactions.