Effects of Aging and Cyclosporin A on Collagen Turnover in Human Gingiva

BACKGROUND: WE AIMED AT CHARACTERIZING THE AGING GINGIVA ANALYZING: i) collagen content and turnover in human gingival tissues and fibroblasts obtained from healthy young and aging subjects. ii) the effect of cyclosporin A administration in human cultured gingival fibroblasts obtained from aging compared to young subjects. METHODS: Morphological analysis was performed on haematoxylin-eosin and Sirius red stained paraffin-embedded gingival biopsies from young and aging healthy subjects. The expression of the main genes and proteins involved in collagen turnover were determined by real time PCR, dot blot and SDS-zymography on cultured young and aging gingival fibroblasts, and after cyclosporin A administration. RESULTS: Our results suggest that in healthy aged people, gingival connective tissue is characterized by a similar collagen content and turnover. Collagen turnover pathways are similarly affected by cyclosporin A treatment in young and aging gingival fibroblasts. CONCLUSIONS: Cyclosporin A administration affects gingival collagen turnover pathways in young and aging fibroblasts at the same extent, suggesting that during aging cyclosporin A administration is not related to relevant collagen turnover modifications

Electron microscopy

Correlative light (LM) and transmission electron microscopic (TEM) analysis is useful, if ultrastructural details of cells need to be related to functional aspects which can only be examined at the LM level. The first protocol presented here introduces a relatively simple way of obtaining TEM images which, on the one hand, reveal ultrastructural details of individual cells and, on the other hand, are large enough to allow a correlation with light micrographs. The second protocol describes a technique for estimating mineral densities of hard tissues using backscattered electron images obtained with a scanning electron microscope. This technique can be used to analyze the mineralization processes which occur throughout tooth formation