A role for MMP-3 genetic variation in atherosclerosis susceptibility?

Association of the matrix metalloproteinase-3 polymorphisms rs679620 and rs3025058 with ischemic stroke risk: a meta-analysis

PURPOSE

The relationship of the matrix metalloproteinase-3 (MMP-3) polymorphisms rs679620 and rs3025058 with ischemic stroke has received much attention. The aim of the present study was to perform a meta-analysis of published case-control studies to evaluate the cumulative evidence.

METHODS

We performed a search of ISI Web of Science, Embase, PubMed, and China National Knowledge Infrastructure databases. Pooled odds ratios (ORs) were appropriately derived from fixed-effects or random-effects models.

RESULTS

We identified seven eligible studies including 5,204 subjects. The pooled analysis showed that the MMP-3 rs679620 A allele carriers had increased risk of ischemic stroke compared with homozygotes for the G allele in Asians (AA + GA vs GG: OR =1.42, 95% CI: 1.05-1.91, P=0.022). Concerning the rs3025058 polymorphism, the results did not suggest an association between rs3025058 genotypes and ischemic stroke risk (5A5A + 6A5A vs 6A6A: OR =1.04, 95% CI: 0.73-1.47, P=0.844; 5A5A vs 6A5A + 6A6A: OR =1.14, 95% CI: 0.74-1.77, P=0.556; and 5A5A vs 6A6A: OR =1.11, 95% CI: 0.68-1.80, P=0.677). In subgroup analysis by ethnicity, no statistically significant associations were demonstrated for rs3025058 in Asians and Caucasians, respectively. There was no evidence for publication bias.

CONCLUSION

Our findings indicate that the rs679620 A allele carriers have increased risk of ischemic stroke in Asians, but there is no association between rs3025058 and ischemic stroke risk.

Evidence for the Involvement of Matrix-Degrading Metalloproteinases (MMPs) in Atherosclerosis

Atherosclerosis leads to blockage of arteries, culminating in myocardial infarction, and stroke. The involvement of matrix-degrading metalloproteinases (MMPs) in atherosclerosis is established and many studies have highlighted the importance of various MMPs in this process. MMPs were first implicated in atherosclerosis due to their ability to degrade extracellular matrix components, which can lead to increased plaque instability. However, more recent work has highlighted a multitude of roles for MMPs in addition to breakdown of extracellular matrix proteins. MMPs are now known to be involved in various stages of plaque progression: from initial macrophage infiltration to plaque rupture. This chapter summarizes the development and progression of atherosclerotic plaques and the contribution of MMPs. We provide data from human studies showing the effect of MMP polymorphisms and the expression of MMPs in both the atherosclerotic plaque and within plasma. We also discuss work in animal models of atherosclerosis that show the effect of gain or loss of function of MMPs. Together, the data provided from these studies illustrate that MMPs are ideal targets as both biomarkers and potential drug therapies for atherosclerosis.

Polymorphisms in LPL, CETP, and HL protect HIV-infected patients from atherogenic dyslipidemia in an allele-dose-dependent manner

HIV-infected patients treated with highly active antiretroviral therapy (HAART) may be predisposed to a lipid profile, associated with increased cardiovascular risk, derived from having high triglycerides (TG) and low high-density lipoprotein cholesterol (HDLc) levels. We propose that genetic variability leaves some HIV-infected patients more predisposed to this lipid profile than others. We performed a cross-sectional, observational study including 321 antiretroviral-treated HIV-infected patients classified as normolipidemic (n=173) or presenting with high TG (≥1.7 mmol/liter) and low HDLc [<1.02 (men) or 1.28 mmol/liter (women)] (n=148) to investigate the impact of 13 polymorphisms of 9 genes affecting lipid metabolism (APOA5, APOC3, LPL, CETP, HL, MTP, APOE, LRP5, and VLDLR genes). The polymorphism rs328 in LPL was 40% significantly more frequent in normolipidemics (p=0.018), and in the same group, polymorphisms rs708272 in CETP and rs1800588 in HL were 10% significantly more frequent (p=0.037 for both polymorphisms). Patients who presented a combination of one to six alleles from these polymorphisms had 10% increased HDLc levels [1.13 (0.40) vs. 1.24 (0.23) mmol/liter, p=0.002] and a trend toward lower triglycerides [2.23 (2.34) vs. 1.89 (1.24) mmol/liter] and lower remnant-like particle cholesterol (RLPc) [16.41 (11.42) vs. 12.99 (11.69) mmol/liter]. This effect was dependent on the number of protective alleles and independent of the regimen administered. Polymorphisms in LPL, CETP, and HL protect HIV-infected patients from developing the dyslipidemia derived from high TG and low HDLc levels in a dose-dependent manner.

Transcriptome-based identification of antioxidative gene expression after fish oil supplementation in normo- and dyslipidemic men

Background

The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs), especially in dyslipidemic subjects with a high risk of cardiovascular disease, are widely described in the literature. A lot of effects of n-3 PUFAs and their oxidized metabolites are triggered by regulating the expression of genes. Currently, it is uncertain if the administration of n-3 PUFAs results in different expression changes of genes related to antioxidative mechanisms in normo- and dyslipidemic subjects, which may partly explain their cardioprotective effects. The aim of this study was to investigate the effects of n-3 PUFA supplementation on expression changes of genes involved in oxidative processes.

Methods

Ten normo- and ten dyslipidemic men were supplemented for twelve weeks with fish oil capsules, providing 1.14 g docosahexaenoic acid and 1.56 g eicosapentaenoic acid. Gene expression levels were determined by whole genome microarray analysis and quantitative real-time polymerase chain reaction (qRT-PCR).

Results

Using microarrays, we discovered an increased expression of antioxidative enzymes and a decreased expression of pro-oxidative and tissue enzymes, such as cytochrome P450 enzymes and matrix metalloproteinases, in both normo- and dyslipidemic men. An up-regulation of catalase and heme oxigenase 2 in both normo- and dyslipidemic subjects and an up-regulation of cytochrome P450 enzyme 1A2 only in dyslipidemic subjects could be observed by qRT-PCR analysis.

Conclusions

Supplementation of normo- and dyslipidemic subjects with n-3 PUFAs changed the expression of genes related to oxidative processes, which may suggest antioxidative and potential cardioprotective effects of n-3 PUFAs. Further studies combining genetic and metabolic endpoints are needed to verify the regulative effects of n-3 PUFAs in antioxidative gene expression to better understand their beneficial effects in health and disease prevention.

Trial registration

ClinicalTrials.gov (ID: NCT01089231)

Human cytomegalovirus induces MMP-1 and MMP-3 expression in aortic smooth muscle cells

Human cytomegalovirus (HCMV) infection may be involved in the pathogenesis of atherosclerosis by modulating functions of smooth muscle cells (SMC). In this study, we performed an oligonucleotide microarray screening of 780 inflammation-associated genes in HCMV-infected aortic SMC (AoSMC). The expression of 31 genes was stimulated and 24 genes were down-regulated following infection with HCMV strain DC-134. Following infection with HCMV strain AD-169 infection, we found 24 genes to be stimulated and 32 genes to be down-regulated. Among these were primarily genes encoding for CC and CXC chemokines, adhesion molecules, and tumor necrosis factor (TNF) receptor superfamily members, apoptosis-related factors, signal transduction molecules and transcription regulators. The up-regulated genes included matrix metalloproteinase (MMP)-1 and MMP-3 in HCMV infected cells. Using RT-PCR and enzyme immunoassay we found stimulated expression of MMP-1 (3.2-fold expression) and MMP-3 (334-fold expression) in HCMV strain DC-134-infected AoSMC at 72 h following infection.The findings of our study suggest that HCMV infection of AoSMC cause an activation of atherosclerosis-relevant factors in SMC. The increased expression of MMPs which have been shown to be involved in atherosclerotic plaque rupture and myocardial infarction is in agreement with the hypothesis that this pathogen might contribute to plaque inflammation in atherosclerotic disease.