Role of Mast Cells in Formation of Tubulointerstitial Fibrosis Resulting from Chronic Kidney Injury: A Case Report

Kidney fibrosis is a complex polyethiological progressive disease consisting in intraorganic connective tissue proliferation accompanied by cicatricial changes. However, the pathogenetic mechanisms of renal fibrosis remain understudied. The article analyzes features of the protease phenotype and histotopography of mast cells (MC) of the kidney, as one of the key players in the remodeling of the extracellular matrix in nephrofibrosis, in a patient diagnosed with "nephrosclerosis with no function of the upper segment of the doubled right kidney in the outcome of refluxing megaureter of the upper segment of the doubled right kidney". The highest MC level was found in areas with fibrotic changes in the kidney. 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 background in the interstitium of the kidney was facilitated by the epigenetic effects of tryptase conditioning the epithelialmesenchymal transition of the nephron epithelium. A selective increase in the number and targeted secretory activity of MCs in limited loci of the kidney parenchyma without visible pathological changes indicates a trigger pathogenetic role of specific proteases in the formation of a local microenvironment with profibrogenic metabolic profile. Thus, MCs are actively involved in the mechanisms of fibrogenic niches formation and evolution of in the kidney, which can be used for developing new treatment strategies for tubulointerstitial fibrosis resulting from chronic kidney damage. Further investigation of mast cells molecular phenotype provides new fundamental mechanisms of fibrosis pathogenesis and serves an important tool for personalized therapy in nephrology. © 2023, Professionalnye Izdaniya. All rights reserved.