Autologous platelet-derived wound healing factor promotes angiogenesis via alphavbeta3-integrin expression in chronic wounds

Abstract

Healing of venous leg ulcers depends on the adhesive interaction and formation of new vascular cells. Angiogenesis on the surface of angiogenic blood vessels requires the vascular integrin alphavbeta3 also known as the vitronectin receptor. Autologous platelet-derived wound healing factor (autologous PDWHF) has been described to regulate the wound healing process by forming granulation tissue in the early healing phase. Here we analysed the influence of autologous PDWHF on the expression of the alphavbeta3 integrin in tissue specimen of venous leg ulcers in comparison with placebo treated controls by using reverse transcriptase-polymerase chain reaction and immunohistochemistry. Our investigations provide evidence that mRNA and protein expression of alphavbeta3 were significantly increased in healing venous leg ulcers after 96 h treatment (p<0.05), whereas the total amount of alphavbeta3 mRNA and protein was not altered in placebo treated patients. In healing leg ulcers the alphavbeta3 integrin was predominantly localized around capillary vessels preferentially at sites of newly formed granulation tissue. Placebo controlled patients displayed no altered expression of the alphavbeta3 integrin in biopsy specimen. These findings suggest that topical autologous platelet-derived wound healing factor influences the process of angiogenesis/revascularization via alphavbeta3 integrin-expression hereby promoting granulation tissue formation in healing leg ulcers.