Elevated level of miR-17 along with decreased levels of TIMP-1 and IL-6 in plasma associated with the risk of in-stent restenosis.

In-stent restenosis is highly related to the deposition of inflammatory extracellular matrix and the migration of endothelial and vascular smooth muscle cells. The miR-17/TIMP-1/interleukin pathway regulates vascular matrix remodeling and plays an important role in the inflammatory reaction. This study identified miR-17 and its related biomarkers in serum that potentially indicated susceptibility to in-stent restenosis (ISR) after coronary artery stenting. Subjects were 42 patients with single de novo coronary artery lesions who underwent regular coronary angiography one year after percutaneous coronary intervention. The clinical baseline information was recorded. Serum levels of biomarkers (including miR-17, TIMP-1, IL-6, IL-8, IL-2R, TNF-alpha, IL-10, and IL-1beta) were measured with real-time PCR or ELISA. Intergroup comparisons were used to compare patients with or without ISR. Compared to levels in the non-restenosis group, the serum miR-17 level was significantly higher (3.13 ± 0.22 vs. 1.06 ± 0.04, p < 0.01) and the serum TIMP-1 and IL-6 levels were significantly lower in the ISR group (TIMP-1: 0.33 ± 0.04 vs. 1.00 ± 0.05, p < 0.01; IL-6: 1.64 ± 0.18 vs. 3.52 ± 0.11, p < 0.01). Moreover, the levels of TIMP-1 and IL-6 decreased as the level of miR-17 increased. Spearman's correlation analysis indicated that the miR-17 level was inversely correlated with TIMP-1 and IL-6 levels. Findings suggest that an elevated level of miR-17 and decreased levels of TIMP-1 and IL-6 may be associated with the risk of ISR, which is in accordance with vascular matrix remodeling and an inflammatory reaction during the pathologic process of ISR. This study highlighted the potential for miR-17, TIMP-1, and IL-6 to serve as biomarkers for ISR.