The main pathogenetic mechanisms of pneumosclerotic changes in the lungs of coal industry workers
Authors: Bondarev Oleg I. , Bugaeva Maria S. , Kazitskaya Anastasiya S. 
Published: May 2022

Introduction. Occupational dust pathology of respiratory organs in Kuzbass remains relevant due to its high prevalence among workers of the coal industry. Entering the body, the components of coal cause the development of pneumoconiotic fibrosis. Innovative ideas about the morphogenesis of fibrosis in recent years have shifted to the molecular level and appeal to the state of cellular receptors, the expression of some genes and the repression of others, a radical change in the cellular phenotype, which is the platform on which complex pathological processes occur. The study aims to research the mechanisms of fibroplastic changes in the lung tissue of miners from the position of epithelial-mesenchymal transformation. Materials and methods. The authors carried out histological and immunohistochemical studies of the respiratory system obtained during fifty autopsy operations of a group of Kuzbass miners working in underground. We studied the bronchial mucosa, respiratory lung tissue, arteries and veins of the small and large circulatory circles. The scientists perfomed immunohistochemical study using monoclonal antibodies (marker of proliferation Ki-67; oncogene of proapoptotic activity Bcl-2; endothelial function factors CD-31 and CD-34; marker of epithelial tissue cytokeratin; muscle tissue markers: actin, desmin, vimentin; connective tissue markers: type III collagen; muscle tissue collagenization marker: EMA; intercellular adhesion molecules E and N-cadherins; macrophage antigen (HAM5600)). Results. Epithelial cells of bronchi of coal industry workers partially lose the ability to express cytokeratins with the replacement of individual cell clusters with cells with non-core expression of maternal epithelial tissue of muscle antigens (vimentin, desmin, actin). When exposed to dust, the epithelial phenotype changes with changes in the quantity, shape and quality of the tissue structures of the lung tissue. Epithelial cells become elongated, fusiform, lose polarity and intercellular connections, acquire mobility and the ability to migrate beyond the tissue histione. Hyperactivation of cellular signaling pathways leads to disorganization and partial disintegration of the cytoskeleton with the appearance of functional mobility of cellular elements. A significant decrease in intercellular adhesive contacts under conditions of prolonged exposure to coal-rock dust leads to suppression of the expression of E-cadherin with partial substitution for N-cadherin contacts. Meanwhile, epithelial cells go through the process of epithelial-mesenchymal transformation, participate in the processes of fibrosis.Activated myofibroblasts are the main source of fibrosis in the lungs , their precursors can be both resident and bone marrow fibroblast-like cells. Dedifferentiated epithelial cells can act as decompensation of the regenerative capacity of lung tissue. Conclusion. The concepts of epithelial-mesenchymal transformation as a mechanism of the main pathological changes in pneumoconiosis should serve as a foundation for further in-depth study and understanding of the complex pathogenetic aspects of this problem in medicine. Ethics. The authors conducted all the studies of the dead miners with the help of a secondary examination of blocks and ready-made histological micro-preparations (glasses) of the material of the Bureau of Forensic Medical examination in Novokuznetsk, Osinniki, Prokopyevsk. The researchers carried out studies of pathomorphological material strictly on the basis of Federal Law No. 323-FZ of 21.11.2011 "On the basics of protecting the health of citizens in the Russian Federation", in particular Article 67 "Conducting pathoanatomic autopsies", Federal Law No. 8-FZ of 12.01.1996 "On Burial and Funeral Business" (Article 5, paragraph 1, 2), as well as in accordance with the Order of the Ministry of Health of April 29, 1994 No. 82 "On the procedure for conducting a pathoanatomical autopsy" (appendix to the order of the Ministry of Health and Medical Industry of 29.04.1994 No. 82), Order of the Ministry of Health of Russia of 24.03.2016 No. 179n "On the rules for conducting pathoanatomical studies".