The rapid lipopolysaccharide-induced release of matrix metalloproteinases 9 is suppressed by simvastatin

Matrix Metalloproteinases as Biomarkers of Atherosclerotic Plaque Instability

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases responsible for tissue remodeling and degradation of extracellular matrix (ECM) proteins. MMPs may modulate various cellular and signaling pathways in atherosclerosis responsible for progression and rupture of atherosclerotic plaques. The effect of MMPs polymorphisms and the expression of MMPs in both the atherosclerotic plaque and plasma was shown. They are independent predictors of atherosclerotic plaque instability in stable coronary heart disease (CHD) patients. Increased levels of MMPs in patients with advanced cardiovascular disease (CAD) and acute coronary syndrome (ACS) was associated with future risk of cardiovascular events. These data confirm that MMPs may be biomarkers in plaque instability as they target in potential drug therapies for atherosclerosis. They provide important prognostic information, independent of traditional risk factors, and may turn out to be useful in improving risk stratification.

The differential statin effect on cytokine production of monocytes or macrophages is mediated by differential geranylgeranylation-dependent Rac1 activation

Monocytes and macrophages contribute to pathogenesis of various inflammatory diseases, including auto-inflammatory diseases, cancer, sepsis, or atherosclerosis. They do so by production of cytokines, the central regulators of inflammation. Isoprenylation of small G-proteins is involved in regulation of production of some cytokines. Statins possibly affect isoprenylation-dependent cytokine production of monocytes and macrophages differentially. Thus, we compared statin-dependent cytokine production of lipopolysaccharide (LPS)-stimulated freshly isolated human monocytes and macrophages derived from monocytes by overnight differentiation. Stimulated monocytes readily produced tumor necrosis factor-α, interleukin-6, and interleukin-1β. Statins did not alter cytokine production of LPS-stimulated monocytes. In contrast, monocyte-derived macrophages prepared in the absence of statin lost the capacity to produce cytokines, whereas macrophages prepared in the presence of statin still produced cytokines. The cells expressed indistinguishable nuclear factor-kB activity, suggesting involvement of separate, statin-dependent regulation pathways. The presence of statin was necessary during the differentiation phase of the macrophages, indicating that retainment-of-function rather than costimulation was involved. Reconstitution with mevalonic acid, farnesyl pyrophosphate, or geranylgeranyl pyrophosphate blocked the retainment effect, whereas reconstitution of cholesterol synthesis by squalene did not. Inhibition of geranylgeranylation by GGTI-298, but not inhibition of farnesylation or cholesterol synthesis, mimicked the retainment effect of the statin. Inhibition of Rac1 activation by the Rac1/TIAM1-inhibitor NSC23766 or by Rac1-siRNA (small interfering RNA) blocked the retainment effect. Consistent with this finding, macrophages differentiated in the presence of statin expressed enhanced Rac1-GTP-levels. In line with the above hypothesis that monocytes and macrophages are differentially regulated by statins, the CD14/CD16-, merTK-, CX₃CR1-, or CD163-expression (M2-macrophage-related) correlated inversely to the cytokine production. Thus, monocytes and macrophages display differential Rac1-geranylgeranylation-dependent functional capacities, that is, statins sway monocytes and macrophages differentially.

Correlation between Sex and Prognosis of Acute Aortic Dissection in the Chinese Population

BACKGROUND

The prevalence, presentation, management, and prognosis of coronary heart disease differ according to sex. Greater understanding on the differences between men and women with acute aortic dissection (AAD) is needed. We aimed to investigate whether sex disparities are found in patients with AAD, and to study sex differences in complications, mortality in-hospital, and long-term.

METHODS

We included 884 patients enrolled in our institute between June 2002 and May 2016. Considering psychosocial factors, treatments, and the outcomes in men versus those in women with AAD, we explored the association of sex with psychosocial characteristics and mortality risk. For categorical variables, significant differences between groups were assessed with the Chi-square test or Fisher's exact test, and continuous parameters were assessed with Student's t-test. Univariate and stratified survival statistics were computed using Kaplan-Meier analysis.

RESULTS

A total of 884 patients (76.1% male, mean age 51.4 ± 11.8 years) were included in this study. There were fewer current smokers in female compared with male (17.5% vs. 67.2%, χ2 = 160.06, P < 0.05). The percentage of men who reported regular alcohol consumption was significantly higher than that in women (40.6% vs. 3.8%, χ2 = 100.18, P < 0.05). About 6.2% (55 of 884) of patients with AAD died before vascular or endovascular surgery was performed, 34.4% (304 of 884) of patients underwent surgical procedures, and 52.7% (466 of 884) and 12.8% (113 of 884) of patients received endovascular treatment and medication. Postoperative mortality similar (6.0% vs. 5.6%, respectively, χ2 = 0.03, P = 0.91) between men and women. Follow-up was completed in 653 of 829 patients (78.8%). Adjustment for age, history of coronary disease, hypertension, smoking and drinking, Type A and use of beta-blocker, angiotensin II receptor blockers, angiotensin converting enzyme (ACE) inhibitor, calcium-channel blockers and statins by multivariate logistic regression analysis suggested that age (odds ratios [OR s], 1.04; 95% confidence interval [CI], 1.01-1.07; P < 0.05), using of calcium-channel blockers (OR, 0.37; 95% CI, 0.18-0.74; P < 0.05), at discharge were independent predictors of late mortality, ACE inhibitors (OR, 1.91; 95% CI, 1.03-3.54; P = 0.04) was independent risk factor of late mortality.

CONCLUSIONS

In Chinese with AAD, sex is not independently associated with long-term clinical outcomes. Age, the intake of calcium-channel blockers at discharge might help to improve long-term outcomes.