Tollip Negatively Regulates Vascular Smooth Muscle Cell-Mediated Neointima Formation by Suppressing Akt-Dependent Signaling.

BACKGROUND: Tollip, a well-established endogenous modulator of Toll-like receptor signaling, is involved in cardiovascular diseases. The aim of this study was to investigate the role of Tollip in neointima formation and its associated mechanisms. METHODS AND RESULTS: In this study, transient increases in Tollip expression were observed in platelet-derived growth factor-BB-treated vascular smooth muscle cells and following vascular injury in mice. We then applied loss-of-function and gain-of-function approaches to elucidate the effects of Tollip on neointima formation. While exaggerated neointima formation was observed in Tollip-deficient murine neointima formation models, Tollip overexpression alleviated vascular injury-induced neointima formation by preventing vascular smooth muscle cell proliferation, dedifferentiation, and migration. Mechanistically, we demonstrated that Tollip overexpression may exert a protective role in the vasculature by suppressing Akt-dependent signaling, which was further confirmed in rescue experiments using the Akt-specific inhibitor (AKTI). CONCLUSIONS: Our findings indicate that Tollip protects against neointima formation by negatively regulating vascular smooth muscle cell proliferation, dedifferentiation, and migration in an Akt-dependent manner. Upregulation of Tollip may be a promising strategy for treating vascular remodeling-related diseases.

Polymorphism in miRNA-1 target site and circulating miRNA-1 phenotype are associated with the decreased risk and prognosis of coronary artery disease.

MiRNA molecules have been identified to play key roles in a broad range of physiologic and pathologic processes. Polymorphisms in microRNA target sites (PolymiRTSs) can disturb or obstruct miRNA binding and consequentially influence regulation of the target genes. A two-step study design was used in this study. A case-control study was designed to assess the relationship between miRNA-1 target site rs9548934C→T polymorphism in target gene (Component of Oligomeric Golgi Complex 6, COG6) and risk of coronary artery disease (CAD) in 1013 patients and 610 normal controls. This genetic variant was also evaluated for the association with major adverse cardiovascular events (MACE) of CAD in a follow-up study, including 785 (785/1013) patients followed up for 42 months. The phenotypes of circulating miRNA-1 levels in 34 cases were slightly lower than that of 40 controls but not significantly different (P = 0.090). The CT and CT/TT genotypes were associated with a 34% and 26% decreased risk of CAD, and the TT and CT/TT genotypes were associated with a 76% and 49% decreased risk of MACE of CAD. Cox regression analysis showed that rs9548937 C/T variant was associated with a decreased risk of MACE, while age, diabetes mellitus, higher levels of CRP (≥ 3.80 mg/L) and three pathological changes in the coronary artery were associated with an increased risk of MACE. Our findings implicate miRNA-1 target site rs9548934C→T genotypes, circulating miRNA-1 phenotype and CRP levels may modulate the occurrence and MACE of CAD.

[Association study on the microRNA-1 target gene polymorphism and the risk of premature coronary artery disease].

OBJECTIVE: To investigate the association between the genetic variant of miRNA-1 target gene COG6 rs9548934 C→T and the risk of premature coronary artery disease (pCAD). METHODS: This study included 226 pACD patients and 275 gender and age matched pCAD-free controls hospitalized in our hospital, diagnosis was made based on coronary angiography (CAG) results. The genotypes of miRNA-1 target gene COG6 rs9548934 C→T were detected by PCR-RFLP. RESULTS: Compared with the wide genotype CC, subjects with the variant genotypes CT of rs9548934 C→T was associated with a 45% lower risk of pACD (adjusted OR = 0.55, 95%CI = 0.36 - 0.82, P = 0.003), and the subjects with CT/TT genotypes were also associated with a significantly lower risk of pACD (adjusted OR = 0.64, 95%CI = 0.44 - 0.92, P = 0.015). Using the median serum TG level (1.20 mmol/L) in control group as the cutoff value, subjects with higher serum TG levels were associated with increased risk of pACD after adjustment for age, gender and BMI (adjusted OR = 2.32, 95%CI = 1.57 - 3.41, P < 0.001). In addition, subjects with higher HDL-C levels were associated with significantly lower risk of pACD (adjusted OR = 0.48, 95%CI = 0.31 - 0.75, P = 0.001). Stratified analyses showed that the risk reduction for pCAD in CT/TT genotypes carriers was more significant in the female subjects (adjusted OR = 0.54, 95%CI = 0.30 - 0.97, P = 0.040), and in subjects with lower TG, TC, HDL-C and LDL-C levels (adjusted OR = 0.62, 95%CI = 0.39 - 0.98, P = 0.040; adjusted OR = 0.55, 95%CI = 0.35 - 0.85, P = 0.008; adjusted OR = 0.43, 95%CI = 0.22 - 0.87, P = 0.018; adjusted OR = 0.49, 95%CI = 0.32 - 0.75, P = 0.001, respectively). CONCLUSION: The polymorphism of miRNA-1 target gene COG6 rs9548934C→T is associated with lower risk of pCAD, especially in female subjects and subjects with lower serum lipid levels.

Polymorphisms of miRNAs genes are associated with the risk and prognosis of coronary artery disease.

BACKGROUND: MicroRNAs (miRNAs) are small, single-stranded, non-protein-coding RNAs of about 22 nucleotides. miRNA molecules have been identified that plays key roles in a broad range of physiologic and pathologic processes. Polymorphisms in the corresponding sequence space are likely to make a significant contribution to phenotypic variation. METHODS AND RESULTS: To assess the variations of rs11614913 T â†’ C in hsa-mir-196a2 and rs3746444 A â†’ G in hsa-mir-499 in the complex etiology of coronary artery disease (CAD), 956 CAD patients diagnosed by coronary arterial angiography and 620 controls were enrolled. Among the patients, 785 (785/956) had complete follow-ups for 42 months. The variant genotypes CC/CT of hsa-mir-196a2 rs11614913 T â†’ C were not associated with a significantly increased risk of CAD (adjusted OR = 1.02, 95% CI = 0.76-1.38), compared with wide genotype TT, but CC and CC/CT genotypes were associated with 34 and 35% increased risks of serious prognosis of CAD (adjusted HR = 1.34, 95% CI = 1.02-1.75 for CC; adjusted HR = 1.35, 95% CI = 1.03-1.75 for CC/CT). In the variant of hsa-mir-499 rs3746444A â†’ G, GG was associated with the 223% increased risk of CAD (adjusted OR = 3.23, 95% CI = 1.56-6.67). Cox regression analysis showed that age, smoking status, numbers of pathological changes in coronary arteries, rs11614913 T â†’ C, and diabetes mellitus were associated with serious prognosis of CAD. CONCLUSION: Our findings strongly implicate the functional miRNAs polymorphisms of hsa-mir-196a2 and hsa-mir-499 genes may modulate the occurrence or prognosis in Chinese CAD.

Functional polymorphisms of matrix metallopeptidase-9 and risk of coronary artery disease in a Chinese population.

Matrix metallopeptidase-9 (MMP-9) plays a pivotal role in vascular remodeling and development of atherosclerotic lesion. The potentially functional MMP-9 polymorphisms may contribute to the susceptibility of coronary artery disease (CAD). A case-control study composed of 762 CAD cases and 555 CAD-free controls was conducted in a Chinese population to investigate the association between the MMP-9 -1562 C>T, R279Q, P574R and R668Q polymorphisms and CAD risk. It was found that the variant genotypes of R279Q, P574R and R668Q were associated with a non-significant decreased risk of CAD when compared with their wild-type genotypes, respectively, Furthermore, compared with those without any variant genotypes for these four nonsynonymouse loci, individuals carrying all four variant genotypes (-1562 CT/TT, 279 RQ/QQ, 574 PR/RR and 668 RQ/QQ) had a 51% decreased risk of CAD (adjusted OR = 0.49; 95% CI = 0.26-0.95, P = 0.033). Although no significant main effects were observed for MMP-9 -1562 C>T locus on CAD risk, variant genotypes of -1562 C>T were associated with a 2.53 increased risk of CAD in subjects with diabetes mellitus (DM) (95% CI = 1.18-5.45, P = 0.018). In CAD cases, variant genotypes of -1562 C>T were associated with a significantly increased risk of MI (adjusted OR, 1.48, 95% CI, 1.01-2.20, P = 0.048). These findings suggest that MMP-9 R279Q, P574R and R668Q may have combined effect in the occurrence of CAD and -1562 CT/TT genotypes may contribute to CAD in diabetics and MI in CAD patients.