Transforming growth factor‐beta 1, 2, 3 and receptor type I and II in diabetic foot ulcers

Abstract Aims To study the distribution of transforming growth factor‐beta (TGF‐β) 1, 2 and 3, and TGF‐β receptor types I and II in diabetic foot ulcers, diabetic skin and normal skin by immunohistochemistry, immunofluorescence and Western blotting. We also compared the TGF‐βs with those of chronic venous ulcers. Methods Skin biopsies were obtained from the leg or the foot of non‐diabetic and diabetic subjects, and from the edge of diabetic foot ulcers and chronic venous ulcers. Distribution (by immunofluorescence and immunocytochemistry) of TGF‐β 1, 2 and 3 and TGF‐β receptors (RI and RII) was done by staining 8‐µm skin sections using appropriate antibodies. Protein levels of TGF‐β were measured by Western blot analysis. Results TGF‐β3 expression was increased in the epithelium at the edge of diabetic foot ulcers, being more intense than diabetic and normal skin ( P = 0.03, 0.02, respectively), as was its expression in venous ulcers compared with normal skin. However, TGF‐β1 expression was not increased in diabetic foot ulcers and chronic venous ulcers, and was comparable to diabetic and normal skin. There was also no increase for the receptors in diabetic foot ulcers. Conclusion The lack of TGF‐β1 up‐regulation in both diabetic foot ulcers and venous ulcers may explain the impaired healing in these chronic wounds, and could represent a general pattern for chronicity.