THE EFFECTS OF AGING ON WOUND-HEALING - IMMUNOLOCALIZATION OF GROWTH-FACTORS AND THEIR RECEPTORS IN A MURINE INCISIONAL MODEL

A number of reports suggest that the process of ageing impairs wound r epair and that strategies to manipulate the age-related wound healing environment are necessary in order to stimulate repair. The process of cutaneous wound repair is controlled by growth factors in an autocrin e and paracrine fashion: it is therefore surprising that the localisat ion of specific growth factors and their receptors has not been docume nted in wound healing with respect to chronological age. In this study the temporal profile of growth factor and receptor immunostaining was assessed within acute incisional wounds in an ageing mouse colony. A delay in appearance of platelet derived growth factor (PDGF) A and B i soforms, and PDGF-alpha and -beta receptors was evident with increasin g animal age, paralleled by a similar finding for epidermal growth fac tor (EGF) and EGF receptor. Transforming growth factor (TGF)-beta 1 an d 2 isoforms were increased at all time points in the wounds of younge r animals, but the TGF-beta 3 isoform increased in intensity from d 7 postwounding in the old mice wounds, and basic fibroblast growth facto r (bFGF) from d 14. The quantity and distribution patterns of the vari ous growth factors and their receptors may explain the age-related dif ferences in wound healing speed and quality, and possibly suggest new therapeutic targets for manipulating wound healing in the aged.