Involutional changes in collagen-elastic skin matrix, markers of cell renewal, and endotheliocyte activity in epidermis and dermis (a pathomorphological study)
Background. The study focused at searching for basic ways to combat involutionary processes. The aim of the study was to identify and evaluate age-related changes in the skin, assess the severity of atrophic changes and the state of markers for cell renewal in the epidermis and dermis of people at different ages. Materials and methods. The study material was skin fragments obtained during autopsy from young (18-35 years) and older (51-80 years) people within 4-12 hours of their death. A comprehensive analysis of pathomorphological material was performed, including a histological histochemical study to determine significant differences in histoarchitectonics of the collagen-elastic dermal matrix and a immunohistochemical study to determine expression of Ki67 and P53, CD31, and ICAM1-positive cells. Results. Age-related changes in skin connective tissue were evident as an increased content of elastic fibers, decreased content of collagen fibers, and decreased number of Ki67 keratinocytes associated with depression of proliferative processes in the epidermis and atrophy of the dermis. The number of P53-positive cells was increased in the epidermis of older adults while the level of ICAM1-positive endotheliocytes was steady. This indicated a high reparative potential and preservation of a part of metabolically active endotheliocytes in the papillary dermis in 50-80 year old people. During ageing, the papillary layer of dermis becomes thinner and the number of capillaries and CD31-positive cells decreases. However, despite the decreased volume of microvasculature, endotheliocytes of older people remain activated. Conclusion. Results of this study suggest a possibility for targeted initiation of neoangiogenetic processes and prevention of extracellular matrix degradation.