Mast cells effect on the condition of skin collagen fibers in microgravity conditions

This paper focuses on mast cells and their effect on skin collagen fibers in microgravity conditions. The aim of the study was to evaluate participation of mast cells (MCs) of the skin from the lateral thigh of C57BL/6J mice in the mechanisms of fibrillogenesis under microgravity condition. Using histochemical protocols, the authors studied the skin of mice that were on board the International Space Station for 21-24 days, as well as animals of vivarium, basal and ground controls. The role of mast cells in collagen fibrillogenesis was studied after the use of protocols for separate and combined histochemical staining with Giemsa’s solution and impregnation of silver. Microsections were analyzed on a hardware-software complex ZEISS Axio Imager. A2 (Carl Zeiss, Germany). It was shown that microgravity conditions resulted in a change in the activity of MC degranulation, localization of MC in the skin, a decrease in the content of large granules, a decrease in the interaction with fibroblasts, fibrocytes, a decrease in the activity of fiber formation, a decrease in co-localization with the reticular fibers of the skin dermis, as well as modification of MC interaction with each other. The paper discusses possible molecular-cellular causes of changes in the activity of fibrillogenesis and polymerization of tropocollagen molecules into collagen fibers of the skin dermis aboard the International Space Station. Thus, exposure to weightlessness caused an increase in the secretory activity of skin MC, modeling the processes of intercellular signaling and weakening the intensity of collagen fibrillogenesis.