Urinary Trypsin Inhibitor Reduced Inflammation Response Induced by Hyperlipidemia.

INTRODUCTION AND OBJECTIVES: Atherosclerosis is recognized as a chronic inflammatory disease. The aim of this study was to examine the role of urinary trypsin inhibitor (UTI) in inflammation response induced by hyperlipidemia in rabbits.

METHODS: Thirty rabbits after injury of the right iliac artery endothelium were randomly divided into 3 groups: control group, model group, and UTI group. Iliac arteries were isolated and histology was performed on arterial regions that were injured by balloon after 8 weeks. Neointimal thickness (NT) and neointimal to media radio (N/M) were measured. Blood lipids, interleukin 6, and tumor necrosis factor-α were evaluated. Macrophages were evaluated by immunohistochemical analysis. MicroRNA-181b (miR-181b) was measured by reverse transcriptase-polymerase chain reaction.

RESULTS: Urinary trypsin inhibitor therapy decreased serum inflammatory factor levels without significant changes in blood lipids. Compared with model group, UTI reduced macrophage infiltration of iliac artery (13.91 ± 2.03% vs 24.21 ± 8.94%, P < .01). Hyperlipidemia reduced the expression of miR-181b and increased NT and N/M ratio. Systemic administration of UTI rescued miR-181b expression and inhibited neointimal formation.

CONCLUSIONS: Urinary trypsin inhibitor could reduce neointimal hyperplasia by inhibiting inflammatory response induced by hyperlipidemia and may become a potential antiatherosclerosis supplement.