Autologous platelet-derived wound healing factor promotes angiogenesis viaalpha(v)beta(3)-integrin expression in chronic wounds

Healing of venous leg ulcers depends on the adhesive interaction and format ion of new vascular cells. Angiogenesis on the surface of angiogenic blood vessels requires the vascular integrin alpha(v)beta(3) also known as the vi tronectin receptor. Autologous platelet-derived wound healing factor (autol ogous PDWHF) has been described to regulate the wound healing process by fo rming granulation tissue in the early healing phase. Here we analysed the i nfluence of autologous PDWHF; on the expression of the alpha(v)beta(3) inte grin in tissue specimen of venous leg ulcers in comparison with placebo tre ated controls by using reverse transcriptase-polymerase chain reaction and immunohistochemistry. Our investigations provide evidence that mRNA and pro tein expression of alpha(v)beta(3) were significantly increased in healing venous leg ulcers after 96 h treatment (p<0.05), whereas the total amount o f alpha(v)beta(3) mRNA and protein was not altered in placebo treated patie nts. In healing leg ulcers the alpha(v)beta(3) integrin was predominantly l ocalized around capillary vessels preferentially at sites of newly formed g ranulation tissue. Placebo controlled patients displayed no altered express ion of the alpha(v)beta(3) integrin in biopsy specimen. These findings sugg est that topical autologous platelet-derived wound healing factor influence s the process of angiogenesis/ revascularization via alpha(v)beta(3) integr in-expression hereby promoting granulation tissue formation in healing leg ulcers.