Age-related changes in the temporal and spatial distributions of fibrillin and elastin mRNAs and proteins in acute cutaneous wounds of healthy humans.

Abstract

Elasticity and resilience of the skin are determined largely by the elastin framework, whose microfibrillar scaffold is composed of fibrillin. To date, the spatial and temporal patterns of expression of human elastin and fibrillin during would healing have not been described. Ninety healthy human subjects underwent 4 mm cutaneous punch biopsy wounds from the upper inner arm, which were re-excised from day 3 to 3 months post-wounding. There were marked changes in the patterns of distribution and the amounts of elastin and fibrillin in sun-protected skin with ageing. However, there were no major age-related differences in the mRNA levels for elastin, fibrillin-1 and fibrillin-2 using in situ hybridization. Elastin and fibrillin appeared in greatest amounts in the wounds of the elderly, particularly in females. A regenerative pattern of elastin and fibrillin arcades at the dermo-epidermal junction was observed in the wounds of aged subjects. mRNA expression of elastin was greatest in the wounds of the aged (from day 3 to day 14 post-wounding) with a similar spatial and temporal pattern to fibrillin-1 expression; this suggests that fibrillin-1 is the major contributor to dermal elastic fibre construction during wound repair. Fibrillin-2 was expressed only in the wounds of the aged and expression was confined to areas proximal to dermal blood vessels. The clear-cut differences in the localization of the two members of the fibrillin family suggest that these have well-defined roles in normal skin and wound tissue. In summary, these data indicate that ageing is associated with increased expression of fibrillin and elastin during acute wound healing and concomitant restoration of the papillary dermal architecture with an improved quality of scarring.