Effects of Aging on Mouse Tongue Epithelium Focusing on Cell Proliferation Rate and Morphological Aspects

Abstract

The aim of this study was to investigate cell proliferation rate and certain morphological features of mouse epithelium as aging progresses. Tongue biopsies were performed on female mice (Mus domesticus domesticus) at 2, 8, 14 and 20 months of age as indicative of adolescence, adulthood, early senescence and senescence, respectively. Histological sections of tongue were stained with hematoxylin-eosin and subjected to silver staining for active nucleolar organizer region counting. Cell proliferation rate and epithelial thickness analysis were carried out. Analysis of variance detected no differences between the groups in terms of numbers of silver-stained dots associated with nucleolar proteins. There was an increase in mean epithelial thickness in adult animals, followed by a gradual reduction until senescence. Mean keratin thickness presented an increase at 8 and 20 months of age. This difference is probably related to puberty, growth or dietary habits. Aging has no influence on oral epithelial proliferation rate in mice. A gradual reduction in epithelial thickness is a feature of aging in mammals. A conspicuous increase in the keratin layer was observed in senescence as an adaptative response to the reduction in epithelial thickness. These results suggest that aging affects the oral epithelium maturation process through a mechanism that is not related to cell proliferation.

Ultrastructural and histological descriptions of the oropharyngeal cavity of the rock pigeon Columba livia dakhlae with special refer to its adaptive dietary adaptations

“…On the other hand, PCNA reaction showed positive immunostaining in the pigeon's tongue. These observations were also recorded by Cameron (1972), Cleaton‐Jones (1976), Leith (1978), Whiteley and Horton (1963), but the absence of the proliferate immunoreactivity was observed by Carrard et al (2008), Çelenligil‐Nazliel, Ayhan, Uzun, and Ruacan (2000) and Hornstein and Schell (1975).…”

The aging mouth: differentiating normal aging from disease

“…Animal studies suggest that the epithelial thickness of the oral mucosa decreases with age, which is accompanied by an increase in the thickness of the keratin layer. The epithelial cell proliferation rate was not altered with age (11).…”

Effect of different presentations of resveratrol on cell proliferation and epitelial thickness of the oral mucosa of wistar rats

“…The results of these studies indicated that intermediate layer cells are responsible for increased cell proliferation, and no change was observed in basal layer cells in any group since these cells are constantly undergoing physiological division. Therefore, when there is a greater demand for cell replacement, intermediate layer cells, which normally do not proliferate very actively, show increased proliferative activity [19][20][21][22] .…”