Increased Expression of A Disintegrin and Metalloproteinase Thrombospondin–1 in Thrombosed Hemodialysis Grafts

Abstract

To use proteomic analysis to identify upregulated and downregulated proteins in thrombosed hemodialysis graft specimens. One of these significantly upregulated proteins was a disintegrin and metalloproteinase thrombospondin-1 (ADAMTS-1), and its expression and activity were determined in thrombosed hemodialysis grafts. Hemodialysis vascular access samples (thrombosed veins, n = 8; control veins, n = 6) were obtained from patients who required surgical revision. Proteomic analysis was performed with isotope-coded affinity tag labeling with multidimensional liquid chromatography followed by tandem mass spectrometry on four thrombosed hemodialysis graft specimens with control veins. Expression of ADAMTS-1 was confirmed by performing immunoprecipitation followed by Western blot analysis. Finally, immunohistochemistry was used to localize expression in a separate group of patients with thrombosed grafts. Thirty-nine unique proteins were common to all four patients. ADAMTS-1 was one of the only significantly upregulated protein (>38 fold). ADAMTS-1 expression was confirmed by performing immunoprecipitation and Western blot analysis and was significantly increased. ADAMTS-1 expression was localized to adventitial macrophages and neutrophils of thrombosed grafts. ADAMTS-1 was significantly upregulated in thrombosed hemodialysis grafts by mass spectrometric analysis and Western blot analysis. Expression was localized to adventitial macrophages and leukocytes. It is hypothesized that ADAMTS-1 may be related to intimal hyperplasia in hemodialysis vascular access grafts. Future work is planned on inhibiting ADAMTS-1 expression and determining the effect on intimal hyperplasia in hemodialysis grafts.