СADHERINS AND СATHEPSIN G IN THE REGULATION OF HOMEOSTASIS AND PROTECTIVE REACTIONS IN THE INTESTINAL EPITHELIUM
Aim of the study. Determination of the potential opportunity of immune protease cathepsin G (Cat G) to participate in the regulation of homeostasis and protective reactions in the intestinal epithelium by interacting with cell adhesion proteins (cadherins). Materials and methods. Biopsies of the human duodenal mucosa were examined by confocal immunofluorescence microscopy using specific antibodies to desmogleins 1-3 (DSGs 1-3), E-cadherin and Cat G of human. Results. The presence of DSG 2 in the contact area of the basolateral membrane of epitheliocytes of intestinal villi and intestinal glands (crypts) with the basal membrane was demonstrated. DSGs 1 and 3 were not detected in the test samples. E-cadherin is located in the zone of the basolateral membrane of enterocytes, goblet cells and Paneth cells. E-cadherin-specific fluorescence is also found between the secretory granules of Paneth cells, which indicates the synthesis of this protein by Paneth cells and/or E-cadherin role in intracellular signaling. In inflammation (duodenitis II-III degree) Cat G-containing granules are localized near the basal membrane of villi and intestinal glands. Conclusions. The catalytic properties of Cat G and its close proximity to the cell adhesion proteins (DSG 2 and E-cadherin) indicate the possibility of interaction of these proteins and their role in the regulation of tissue metabolism, modification and maintenance of the barrier properties of the epithelium during the development of protective and / or pathological processes.