Innate immunity and atherogenesis

Proteomic profile of human aortic stenosis: insights into the degenerative process

Degenerative aortic stenosis is the most common worldwide cause of valve replacement. While it shares certain risk factors with coronary artery disease, it is not delayed or reversed by reducing exposure to risk factors (e.g., therapies that lower lipids). Therefore, it is necessary to better understand its pathophysiology for preventive measures to be taken. In this work, aortic valve samples were collected from 20 patients that underwent aortic valve replacement (55% males, mean age of 74 years) and 20 normal control valves were obtained from necropsies (40% males, mean age of 69 years). The proteome of the samples was analyzed by quantitative differential electrophoresis (2D-DIGE) and mass spectrometry, and 35 protein species were clearly increased in aortic valves, including apolipoprotein AI, alpha-1-antitrypsin, serum albumin, lumican, alfa-1-glycoprotein, vimentin, superoxide dismutase Cu-Zn, serum amyloid P-component, glutathione S-transferase-P, fatty acid-binding protein, transthyretin, and fibrinogen gamma. By contrast, 8 protein species were decreased (transgelin, haptoglobin, glutathione peroxidase 3, HSP27, and calreticulin). All of the proteins identified play a significant role in cardiovascular processes, such as fibrosis, homeostasis, and coagulation. The significant changes observed in the abundance of key cardiovascular proteins strongly suggest that they can be involved in the pathogenesis of degenerative aortic stenosis. Further studies are warranted to better understand this process before we can attempt to modulate it.

The Relationship Between Serum Pentraxin 3 and Central Obesity in ST-Segment Elevation Myocardial Infarction Patients

Background and Objectives

As shown in previous studies, pentraxin 3 (PTX3) can be a useful inflammatory marker for metabolic syndrome and central obesity. Serum PTX3 levels are also an independent factor associated with visceral fat area. The aim of this study was to assess the role of PTX3 as an inflammatory maker in patients with central obesity undergoing primary percutaneous coronary intervention (PCI) following an ST-segment elevation myocardial infarction (STEMI).

Subjects and Methods

From December 2007 to June 2008, 40 subjects (mean age: 61±11 years, M : F=34 : 6) with STEMI who underwent primary PCI were enrolled. We determined waist circumference, waist/hip ratio, body mass index (BMI), and visceral and total fat area via fat computed tomography (FAT-CT), and compared them with serum PTX3 concentrations.

Results

The serum PTX3 concentration was closely related to FAT-CT-estimated visceral fat area (r=0.41, p<0.01) and total fat area (r=0.38, p=0.01), respectively. The serum PTX3 concentration was not related to waist circumference (r=0.27, p=0.20), waist circumference/hip ratio (r=0.25, p=0.16), BMI (r=0.04, p=0.80) and lipid profiles, respectively. Among the parameters determining metabolic syndrome, an increasing visceral fat area had the strongest association with PTX3 concentrations.

Conclusion

In patients with STEMI, PTX3 is associated with central obesity and it is significantly and independently correlated with visceral fat area. FAT-CT-estimated visceral fat area is the most reliable factor associated with serum PTX3 levels in patients with STEMI and central obesity.

Porphyromonas gingivalis fimbriae-dependent interleukin-6 autocrine regulation by increase of gp130 in endothelial cells

BACKGROUND AND OBJECTIVE

Local persistent infection by Porphyromonas gingivalis leads to inflammatory systemic diseases, such as atherosclerosis. We have reported previously that avirulent P. gingivalis fimbriae-dependent invasion into endothelial cells might be involved in progression of atherosclerosis. Although interleukin-6 (IL-6) regulates progression of atherosclerosis, little is known about the relationship of P. gingivalis fimbriae-dependent invasion to IL-6 regulation in endothelial cells.

MATERIAL AND METHODS

We examined the secretion of IL-6 and the expression of the IL-6 signal transducer gp130 in human umbilical vein endothelial cells (HUVEC) infected with the wild-type FDC381 strain of P. gingivalisand a fimbriae-deficient mutant (fimA) by enzyme-linked immunosorbent assay, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry (fluorescence-activated cell sorting, FACS) analysis.

RESULTS

Coculture of HUVEC with P. gingivalis resulted in increase of IL-6 secretion at 24 h postinfection. Interestingly, the increase was inhibited significantly in HUVEC infected with the P. gingivalis fimA mutant. In addition, the increase of IL-6 secretion induced by P. gingivalis infection was significantly impaired by the meiosis specific kinase 1 inhibitor, PD98059, or the nuclear factor kappaB inhibitor, Bay11-7082. Furthermore, we demonstrated that gp130 expression increased with P. gingivalis infection. Importantly, gp130 expression was significantly impaired by P gingivalis fimA mutant infection compared with wild-type P. gingivalis infection, as assessed by both quantitative RT-PCR and FACS analysis.

CONCLUSION

Our findings indicate that P. gingivalis fimbriae are important factors in the autocrine regulation of IL-6, by increasing gp130 in endothelial cells.

Epstein-Barr virus-encoded dUTPase enhances proinflammatory cytokine production by macrophages in contact with endothelial cells: evidence for depression-induced atherosclerotic risk

Increased levels of proinflammatory cytokines, TNF-alpha and IL-6, predict mortality and morbidity. In cardiovascular disease patients, they are observed in atherosclerotic lesions and serum. Factors behind the increased levels of these cytokines are multifaceted and may include latent herpesviruses, such as Epstein-Barr virus (EBV) that can be reactivated by stress. Previously, we showed that the EBV-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase), a protein synthesized in the early phase of virus replication, can induce human monocytes/macrophages to produce TNF-alpha and IL-6. In this study, we modeled the interactions that take place between macrophages and endothelial cells in vivo using human umbilical vein endothelial cells (HUVEC). HUVEC were stimulated by soluble factors induced by EBV dUTPase-treated monocyte-derived macrophages (MDM) that resulted in the upregulation of VCAM-1 and ICAM-1. These changes were related to MDM production of TNF-alpha following the activation of NF-kappaB. In a previous study, chronically stressed dementia caregivers had elevations in plasma IL-6 levels, a risk for cardiovascular disease. We found a relationship between plasma IL-6 levels and neutralizing antibody titers to EBV dUTPase suggesting that one source of the plasma IL-6 observed in our previous study could be related to the effect of EBV-encoded dUTPase on macrophages. The results suggest that EBV-encoded dUTPase can enhance production of proinflammatory cytokines by monocytes/macrophages in contact with endothelial cells of blood vessels, and may play a role in cardiovascular pathology and chronic inflammation.

Cardiac manifestations in the antiphospholipid syndrome

Experimental evidence reveals that aPL are not only markers of APS, but also may play a causative role in the development of vascular thrombosis and pregnancy morbidity. The pathogenic mechanisms of aPL seem to be heterogeneous, including endothelial cell activation, the direct inhibition of the activated protein C pathway, abnormalities in platelet function, and in complement activation. aPLs induce proadhesive, proinflammatory, and procoagulant molecules that provide a persuasive explanation for induction of thrombosis in APS. Cardiac manifestations in APS include valve abnormalities (valve thickening and vegetations), occlusive arterial disease (atherosclerosis and myocardial infarction), intracardiac emboli, ventricular dysfunction, and pulmonary hypertension. aPL may be associated with accelerated atherosclerosis in APS patients. Valve disease is the most important and most common cardiac manifestation of APS. The precise mechanism by which valves become deformed is not yet fully known.