Negative pressure wound therapy is associated with up-regulation of bFGF and ERK1/2 in human diabetic foot wounds

Abstract

Chronic foot wounds are a leading cause of morbidity and hospitalization for patients with diabetes. Negative pressure wound therapy (NPWT) is known to promote healing of diabetic foot wounds, but the underlying molecular mechanisms remain elusive. We propose to gain molecular insights into the wound healing promoting signals underlying the effects of NPWT on diabetic foot wounds in humans. We assessed 30 patients with diabetic foot ulcers. Of these cases, 15 were treated with NPWT, while 15 patients were treated with traditional gauze therapy. Granulated tissue was harvested before and after treatment in both patient groups and histologically analyzed with hematoxylin & eosin as well as Masson's trichrome staining methods. Immunohistochemistry and Western blot analysis was performed to evaluate expression of basic fibroblast growth factor (bFGF) and extracellular signal-regulated kinase (ERK)1/2, previously associated with promoting cellular growth and/or wound healing. Unlike controls, the wounds in the NPWT-treated diabetic patients developed characteristic features of granulated tissue with increased collagen deposition. Immunohistochemical analysis also revealed an increase in bFGF levels in NPWT-treated patients. Western blot analysis further showed a significant up-regulation of bFGF and phosphorylated ERK1/2 protein levels in the NPWT-treated diabetic patients vs. controls. Our studies reveal that NPWT is associated with an up-regulation of bFGF and ERK1/2 signaling, which may be involved in promoting the NPWT-mediated wound healing response.