Research Institute of Experimental Biology and Medicine, Burdenko Voronezh State Medical University, 394036 Voronezh, Russia.
Research and Educational Resource Center for Immunophenotyping, Digital Spatial Profiling and Ultrastructural Analysis Innovative Technologies, Peoples' Friendship University of Russia, 117198 Moscow, Russia.
Int J Mol Sci. 2023 Jan 18;24(3):1939. doi: 10.3390/ijms24031939.
Mechanisms of adaptive rearrangements of the fibrous extracellular matrix of connective tissues under microgravity practically remain unexplored, despite the most essential functions of the stroma existing to ensure the physiological activity of internal organs. Here we analyzed the biomaterial (the skin dermis) of C57BL/6J mice from the Rodent Research-4 experiment after a long stay in space flight. The biomaterial was fixed onboard the International Space Station. It was found that weightlessness resulted in a relative increase in type III collagen-rich fibers compared to other fibrous collagens in the skin. The number of mast cells in the skin did not change, but their secretory activity increased. At the same time, co-localization of mast cells with fibroblasts, as well as impregnated fibers, was reduced. Potential molecular-cellular causes of changes in the activity of fibrillogenesis under zero-gravity conditions and the slowdown of the polymerization of tropocollagen molecules into supramolecular fibrous structures, as well as a relative decrease in the number of fibrous structures with a predominant content of type-I collagen, are discussed. The data obtained evidence of the different sensitivity levels of the fibrous and cellular components of a specific tissue microenvironment of the skin to zero-gravity conditions. The obtained data should be taken into account in the systematic planning of long-term space missions in order to improve the prevention of undesirable effects of weightlessness.
尽管基质存在的最基本功能是确保内部器官的生理活性，但在微重力下结缔组织纤维细胞外基质的适应性重排的机制实际上仍未得到探索。在这里，我们分析了在 Rodent Research-4 实验中长时间处于太空飞行后的 C57BL/6J 小鼠的生物材料（皮肤真皮）。生物材料固定在国际空间站上。结果发现，与皮肤中的其他纤维胶原相比，失重导致富含 III 型胶原的纤维相对增加。皮肤中的肥大细胞数量没有变化，但它们的分泌活性增加。同时，与成纤维细胞以及浸渍纤维的肥大细胞共定位减少。讨论了在零重力条件下纤丝形成活性以及原胶原蛋白分子聚合为超分子纤维结构的速度减慢的潜在分子-细胞原因，以及具有主要 I 型胶原含量的纤维结构数量相对减少的原因。获得的数据证明了皮肤特定组织微环境的纤维和细胞成分对零重力条件的不同敏感程度。在系统规划长期太空任务时应考虑到这些数据，以改善对失重不良影响的预防。
