Multiplexed analysis of matrix metalloproteinases in leg ulcer tissue of patients with chronic venous insufficiency before and after compression therapy

Elevated matrix metalloproteinases (MMP) levels have been implicated in the pathogenesis of chronic venous insufficiency ulcers. Quantitative measurements of a broad range of MMP proteins in human tissue treated with compression bandaging have not been reported. The goal of this study was to determine the expression of a wide range of proteases in untreated venous leg ulcer tissue and the changes in these levels after 4 weeks of high-strength compression therapy. Twenty-nine limbs with new or untreated chronic venous insufficiency and leg ulceration received therapy for 4 weeks with sustained high compression bandaging. Biopsies were obtained from healthy tissue and from ulcerated tissue before and after therapy. A novel multiplexed protein assay was used to measure multiple MMPs in a single sample. MMP protein activity, TIMP protein levels, and gene expression levels were also addressed. MMP1, 2, 3, 8, 9, 12, and 13 protein levels were elevated in ulcer tissue compared with healthy tissue. MMP8 and 9 were highly expressed in ulcer tissue. MMP3, 8, and 9 significantly decreased following treatment. Reduction in the levels of MMP1, 2, and 3 was associated with significantly higher rates of ulcer healing at 4 weeks. We conclude that compression therapy results in a reduction of the pro-inflammatory environment characterizing chronic venous ulcers, and ulcer healing is associated with resolution of specific elevated levels of protease expression.