Tumor necrosis factor receptors-1 in fibroblasts of human dermis in the process of physiological aging

The aim of this work was to examine the content of TNF receptors-1 in fibroblasts of human dermis from the development until 85 years old, and defining of a role of this protein age-dependent changes in the number of fibroblasts in the dermis. The study was performed on skin samples from the lower part of the anterior surface of the neck obtained during autopsy of human fetuses who died from various causes antenatally at 20-40 weeks of pregnancy, and people who died from various causes at the age from birth to 85 years. A total of 121 skin fragments were used. TNF receptors-1, proliferating cells nuclear antigen (PCNA), marker of fibroblasts vimentin were detected with indirect immunohistochemical staining. Results showed that portion of fibroblasts with positive staining for TNF receptors-1 in the dermis is increased from 20 weeks of pregnancy to 20 years old followed by a little decrease to 40 years old. In age interval from 40 to 85 years old, the number of fibroblasts in dermis with TNF receptors-1 remain almost unchanged, but their level is lower than that observed from birth to 20 years old interval. General number and portion of PCNA positive fibroblasts in dermis are decreased with age with more expressed changes until 40 years old. Correlation analysis showed that age dependent decrease in the number of fibroblasts and their proliferative activity is significantly associated with changes in the number of dermal fibroblasts positively stained for TNF receptors-1. Results obtained allow to suggest that TNF receptors-1 plays a role in age dependent decrease in the number of fibroblasts and their proliferation in human dermis.