Effect of healing on the expression of transforming growth factor [beta]s and their receptors in chronic venous leg ulcers

Abstract

The transforming growth factor βs are of major importance in the wound repair process; however, no studies to date have investigated the role of the transforming growth factor β receptors in chronic venous leg ulcers or what effect healing has on these proteins. To determine whether the transforming growth factor β peptides and their receptors are expressed in chronic venous wounds, we used immunofluorescent analysis and quantitative competitive reverse transcription polymerase chain reaction to identify the protein and mRNA expression, respectively. Biopsy samples from wounds and normal skin were collected from 12 patients with chronic venous leg ulcers and three patients undergoing reconstructive surgery, respectively. Additionally four of the chronic venous leg ulcer patients were re-biopsied between 2 and 8 wk after the first biopsy when the wounds had entered the healing phase. The tissue excised from the ulcers included the surrounding intact skin, the ulcer edge, and the ulcer base. Immunofluorescent staining for transforming growth factors β1, β2, and β3 was observed within the epidermis of the skin surrounding the chronic venous ulcers and in fibroblasts and inflammatory cells of the dermis, although this staining was not as strong as that seen in normal unwounded skin. Very little staining could be seen within the ulcers for any of the ligands, however. In contrast the transforming growth factor β type I receptor was observed throughout the ulcers and the normal unwounded skin biopsies, particularly in the basal epidermal cells. No immunofluorescence for the type II transforming growth factor β receptor was observed in any of the ulcer biopsies investigated, although it was observed throughout the epidermis and in fibroblasts and inflammatory cells in the surrounding skin. Quantitative, competitive reverse transcription polymerase chain reaction was used to analyze mRNA expression for transforming growth factor.