TIMP-3 suppresses the proliferation and migration of SMCs from the aortic neck of atherosclerotic AAA in rabbits, via decreased MMP-2 and MMP-9 activity, and reduced TNF-α expression

The present study investigated the role of tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) in regulating the proliferation, migration, apoptosis and activity of matrix metalloproteinase (MMP)-2 and −9, during the development of an atherosclerotic abdominal artery aneurysm (AAA). Experiments were conducted using rabbit AAA neck (NA) smooth muscle cells (SMCs), to investigate the potential for TIMP-3 to be used as a novel stent coating in preventing aortic dilation adjacent to the AAA. The atherosclerotic AAA model was induced in New Zealand white rabbits via a 6-week high-cholesterol diet, followed by incubation of the targeted aortic region with elastase. SMCs were isolated from the aorta adjacent to the aneurysm 30 days after AAA model induction, and stimulated with 3, 10, 30 or 100 ng/ml TIMP-3. Cell proliferation was investigated using Cell Counting Kit-8 reagent, migration was examined using a Boyden chamber assay and apoptotic rate was analyzed using the Annexin V-fluorescein isothiocyanate Apoptosis Detection kit. Gelatin zymography and ELISA were used to measure the activity of MMP-2 and MMP-9, and the expression of tumor necrosis factor-α (TNF-α), respectively. Analysis of cell proliferation indicated that 10, 30 and 100 ng/ml TIMP-3 reduced cell viability. Cell migration was decreased by 10, 30 and 100 ng/ml TIMP-3. MMP-2 activity was inhibited by 10, 30 and 100 ng/ml TIMP-3, and MMP-9 activity was suppressed by 30 and 100 ng/ml TIMP-3. The protein levels of secreted TNF-α were reduced by 10, 30 and 100 ng/ml TIMP-3. The present study demonstrated the ability of 30 and 100 ng/ml TIMP-3 to attenuate migration and proliferation, and to inhibit the activity of MMP-2, MMP-9 and TNF-α secretion of NA SMCs. In conclusion, TIMP-3 may be considered a potential therapeutic drug for use in a novel drug-eluting stent, to attenuate the progressive dilation of the aortic NA.