Atherosclerosis and systemic lupus erythematosus

Cardiovascular Disease in Patients With Systemic Lupus Erythematosus: Potential for Improved Primary Prevention With Statins

Cardiovascular disease (CVD) is a significant cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). This is especially true in SLE patients with traditional CVD risk factors (eg, hypertension, hyperlipidemia, obesity) and disease-related risk factors (eg, increased SLE disease activity, elevated C-reactive protein levels, and antiphospholipid antibodies). The only guidelines in the primary prevention of CVD in SLE patients involve reducing traditional risk factors, but there are additional therapies that may be beneficial, including statin use. Current data on statin use for prevention of CVD in SLE patients are limited, but there have been some promising results. Statin use has been shown to be especially important in SLE patients for decreasing low-density lipoprotein levels and preventing CVD in hyperlipidemic patients. In addition, there is evidence suggesting that it may be beneficial to use statins in SLE patients with chronically elevated high-sensitivity C-reactive protein levels and antiphospholipid antibodies. It is important to continue to investigate the impact of statins on CVD in SLE patients, as they could significantly improve outcomes in patients with this disease.

High Burden of Premature Arteriosclerosis on Renal Biopsy Results in Incident Lupus Nephritis

OBJECTIVE

Cardiovascular disease (CVD) is accelerated in patients with systemic lupus erythematosus and lupus nephritis (LN). Despite the literature suggesting that renal arteriosclerosis predicts CVD in other glomerulonephritis diseases, arteriosclerosis grading and reporting might be particularly overlooked in LN biopsies. Our objective was to examine the burden of renal arteriosclerosis in LN and to assess whether arteriosclerosis is underreported in LN biopsies.

METHODS

We identified all patients with LN undergoing kidney biopsy between 1994 and 2017 at an academic center. We interpreted LN biopsy reports to classify the Banff categories of absent, mild, moderate, or severe renal arteriosclerosis. The prevalence of renal arteriosclerosis was compared with the prevalence published for age-matched healthy peers, and predictors of arteriosclerosis were examined. We overread biopsies for Banff renal arteriosclerosis grading and compared to pathology reports.

RESULTS

Among 189 incident patients with LN, renal arteriosclerosis prevalence was 2 decades earlier compared to their healthy peers, affecting 40% of patients ages 31-39 years with LN compared to 44% of healthy peers ages 50-59 years. A multivariable analysis showed a 3-fold higher odds of renal arteriosclerosis in patients ages ≥30 years with LN. LN chronicity on biopsy results predicted a 4-fold higher odds of renal arteriosclerosis. The overreads determined that 50% of standard LN biopsy reports missed reporting the presence or absence of renal arteriosclerosis.

CONCLUSION

Renal arteriosclerosis is accelerated by 2 decades in patients with LN compared to their healthy peers and is overlooked by pathologists in half of the routine biopsy reports. We propose incorporating Banff renal arteriosclerosis grading in all LN biopsy reports.

Systemic autoimmunity induced by the TLR7/8 agonist Resiquimod causes myocarditis and dilated cardiomyopathy in a new mouse model of autoimmune heart disease

Systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) show significant heart involvement and cardiovascular morbidity, which can be due to systemically increased levels of inflammation or direct autoreactivity targeting cardiac tissue. Despite high clinical relevance, cardiac damage secondary to systemic autoimmunity lacks inducible rodent models. Here, we characterise immune-mediated cardiac tissue damage in a new model of SLE induced by topical application of the Toll-like receptor 7/8 (TLR7/8) agonist Resiquimod. We observe a cardiac phenotype reminiscent of autoimmune-mediated dilated cardiomyopathy, and identify auto-antibodies as major contributors to cardiac tissue damage. Resiquimod-induced heart disease is a highly relevant mouse model for mechanistic and therapeutic studies aiming to protect the heart during autoimmunity.

Summary: A novel mouse model of autoimmune-mediated heart damage to study the underlying mechanisms and test therapeutic options for systemic autoimmunity.

Statins: immunomodulators for autoimmune rheumatic disease?

Inhibitors of 3-hydroxy-3-methylgluttaryl coenzyme A (HMG-CoA) reductase, or statins, are used extensively to reduced elevated lipid levels and reduce cardiovascular risk. However, accumulated evidence suggests that stains not only act by lowering cholesterol levels, but also exert pleiotropic effects on many essential cellular functions including cell proliferation, differentiation, and survival and participate in the regulation of cell shape and motility. Thus cardiovascular benefit is provided by lowering raised cholesterol levels and by modulation of the inflammatory component of this disease. Such an anti-inflammatory effect may also benefit patients with autoimmune rheumatic disease. This overview assesses the evidence for using statins in patients with rheumatoid arthritis and systemic lupus erythematosus (SLE).

Evaluation of early cardiac dysfunction in patients with systemic lupus erythematosus with or without anticardiolipin antibodies

The aim of this study was to use transthoracic Doppler echocardiographic (TTE) imaging methods to identify cardiac dysfunction, an indicator of subclinical atherosclerosis in asymptomatic systemic lupus erythematosus (SLE) patients in terms of cardiac effects. This study involved 80 patients: a study group ( n = 50) and control group ( n = 30). They were categorized into four subgroups: anticardiolipin antibodies (aCL) (+) ( n = 14) and aCL (−) ( n = 36); systemic lupus erythematosus disease activity index (SLEDAI) ≥ 6 ( n = 15) and SLEDAI < 6 ( n = 35); disease period ≥ 5 years ( n = 21) and disease period < 5 years ( n = 29); major organ involvement (+) ( n = 19), major organ involvement (−) ( n = 31). The ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity (E/E′) for the study group was found to be higher than the control ( p < 0.01). Systolic septal motion velocity (Ssm) was lower in the study group compared with the control ( p < 0.01). Left atrium (LA) dimension was greater in the study group than the control ( p < 0.01). Ssm was found to be lower in the aCL (+) patients compared with the control and aCL (−) groups ( p < 0.01, p < 0.05, respectively). LA dimension was greater in the aCL (+) and (−) groups compared with the control, ( p < 0.01, p < 0.05, respectively) and aCL groups compared with each other ( p < 0.05). The E/E′ ratio for the aCL (+) and (−) groups was found to be greater than the control ( p < 0.05). In the study, both the Ssm and the late diastolic septal velocity (sA′) was found to be lower in the SLEDAI ≥6 group compared with SLEDAI<6 group, ( p < 0.001, p < 0.05, respectively). LA dimension was statistically greater in the SLEDAI ≥6 group compared with the SLEDAI <6 group ( p < 0.001). E′ and early diastolic septal velocity (sE′) were statistically lower in the disease period >5 years group compared with the disease period <5 years group ( p < 0.01, p < 0.05, respectively). Carrying out regular scans with TTE image of SLE patients is important in order to identify early cardiac involvement during monitoring and treatment. Identifying early cardiac involvement in SLE may lead to a reduction in mortality and morbidity rates.

Longitudinal evolution of risk of coronary heart disease in systemic lupus erythematosus

OBJECTIVE

To produce evidence on the longitudinal evolution of risk factors for coronary heart disease (CHD) in patients with systemic lupus erythematosus (SLE).

METHODS

Based on data for 115 patients from the Montreal General Hospital Lupus Clinic (1971-2003) and for 4367 control subjects from the Framingham Offspring Study (1971-1994), we investigated the temporal evolution of total serum cholesterol, systolic blood pressure (SBP), body mass index (BMI), blood glucose, and estimated risk for CHD (reflecting the balance of changes in different risk factors). In analyses limited to patients with SLE, we assessed the effect of SLE duration on each risk factor, adjusting for age, calendar time, sex, baseline level of the risk factor, and medication use. Next, we assessed how the adjusted difference in the values of the risk factors between SLE and controls changes over time.

RESULTS

Among patients with SLE, longer disease duration was independently associated with higher SBP and blood glucose levels. Compared with controls, these patients appeared to have accelerated rates of increase in total cholesterol, blood glucose, and overall estimated CHD risk. The rate of increase in BMI was lower in patients with SLE than in controls.

CONCLUSION

Elevated CHD risk in patients with SLE appears to be at least partially mediated by accelerated increases in some CHD risk factors, longitudinal trajectories of which increasingly diverge over time from those of population controls.

Cardiovascular disease in systemic lupus erythematosus: the role of traditional and lupus related risk factors

Atherosclerosis is a chronic inflammatory disorder characterized by immune cell activation, inflammation driven plaque formation and subsequent destabilization. In other disorders of an inflammatory nature, the chronic inflammatory state per se has been linked to acceleration of the atherosclerotic process which is underlined by an increased incidence of cardiovascular disease (CVD) in disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and antiphopholipid (Hughes) syndrome (APS). SLE is an autoimmune disease that may affect any organ. Premature coronary heart disease has emerged as a major cause of morbidity and mortality in SLE. In addition to mortality, cardiovascular morbidity is also markedly increased in these patients, compared with the general population. The increased cardiovascular risk can be explained only partially by an increased prevalence of classical risk factors for cardiovascular disease; it also appears to be related to inflammation. Inflammation is increasingly being considered central to the pathogenesis of atherosclerosis and an important risk factor for vascular disease. Recent epidemiologic and pathogenesis studies have suggested a great deal in common between the pathogenesis of prototypic autoimmune disease such as SLE and that of atherosclerosis.

We will review traditional risk factors for CVD in SLE. We will also discuss the role of inflammation in atherosclerosis, as well as possible treatment strategies in these patients.

Comparative assessment of vascular function in autoimmune rheumatic diseases: considerations of prevention and treatment

Numerous autoimmune-inflammatory rheumatic diseases have been associated with accelerated atherosclerosis or other types of vasculopathy leading to increased cardio- and cerebrovascular disease risk. Traditional risk factors, as well as the role of systemic inflammation including cytokines, chemokines, proteases, autoantibodies, adhesion receptors and others have been implicated in the development of these vascular pathologies. The characteristics of vasculopathies may significantly differ depending on the underlying disease. While classical accelerated atherosclerosis has been associated with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) or spondyloarthropathies (SpA), obliterative vasculopathy may rather be characteristic for systemic sclerosis (SSc) or mixed connective tissue disease (MCTD). Antiphospholipid antibodies have been implicated in vasculopathies underlying SLE, antiphospholipid syndrome (APS), RA and MCTD. There is also heterogeneity with respect to inflammatory risk factors. Cytokines, such as tumor necrosis factor-α (TNF-α) or interleukin 6 (IL-6) and immune complexes are primarily involved in arthritides, such as RA, SpA, as well as in SLE. On the other hand, autoantibodies including anti-oxLDL anti-cardiolipin and anti-β2GPI are rather involved in SLE- and APS-associated vasculopathies. Regarding the non-invasive assessment of vascular function, endothelial dysfunction, overt atherosclerosis and vascular stiffness may be indicated by brachial artery flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT) and aortic pulse-wave velocity (PWV), respectively. These abnormalities have been described in most inflammatory rheumatic diseases. While ccIMT and stiffness are relatively stable, FMD may be influenced by many confounding factors. In addition to traditional vasculoprotection, immunosuppressive agents including corticosteroids, traditional and biologic DMARDs may have significant vascular and metabolic effects. The official EULAR recommendations on the assessment and management of cardiovascular disease in arthritides have just been published, and similar recommendations in connective tissue diseases are to be developed soon.

Influence of predialysis comorbidity and damage accrual on mortality in lupus patients treated with peritoneal dialysis

Objective: Although there have been many studies on systemic lupus erythematosus (SLE) patients, there are few data about survival analysis of lupus patients receiving dialysis. Therefore, the objective of this study is to analyze risk factors predicting mortality in lupus patients treated with peritoneal dialysis (PD). In addition, we also delineate the relationship between predialysis comorbid illnesses, damage accrual, and mortality in lupus patients undergoing PD. Methods: This longitudinal cohort study included 38 lupus patients undergoing PD between 1990 and 2008. The clinical parameters, disease activity (non-renal SLEDAI, nrSLEDAI), comorbid illnesses, and damage accrual were collected. We applied the Charlson Comorbidity Index (CCI), Khan Index, and Davies Index to elucidate the impact of predialysis comorbidity on mortality. Moreover, we examined prognostic value of predialysis SDI (Systemic Lupus International Collaborating Clinics Disease Damage Index) for lupus PD patients. Results: There were 33 women and five men included for analysis. The mean age at PD entry was 32.2 ± 10.4 years and mean duration of PD was 39.7 ± 22.4 months. The nrSLEDAI score during PD significantly decreased, compared to the predialysis one (2.13 ± 2.09 vs. 4.00 ± 3.08, p < 0.001). All comorbidity indices and SDI scores were significantly and positively correlated with each other (p < 0.001). Univariate Cox regression analysis showed that serum creatinine level, date at PD entry, and the CCI were predictors for mortality. The predialysis nrSLEDAI and SDI scores did not have roles in predicting mortality of lupus PD patients. Conclusions: The predialysis CCI, instead of SDI, determines an increased risk for mortality in lupus patients treated with PD. The prognosis of lupus patients treated with PD largely depends on the severity of predialysis comorbidity, especially cardiovascular diseases.

Myocardial Left Ventricular Dysfunction in Patients with Systemic Lupus Erythematosus: New Insights from Tissue Doppler and Strain Imaging

Objective.

Systemic lupus erythematosus (SLE) is associated with high cardiovascular morbidity and mortality. Cardiovascular involvement is frequently underestimated by routine imaging techniques. Our aim was to determine if new echocardiographic imaging modalities like tissue Doppler (TDI), strain rate (SRR), and strain (SRI) imaging detect abnormalities in left ventricular (LV) function in asymptomatic patients with SLE.

Methods.

Sixty-seven young patients with SLE (mean age 42 ± 10 yrs) without typical symptoms or signs of heart failure or angina, and a matched healthy control group (n = 40), underwent standard transthoracic echocardiography, TDI, SRR, and SRI imaging of the LV as well as assessment of disease characteristics.

Results.

Despite findings within the normal range on routine standard 2-dimensional echocardiography, SLE was associated with significantly impaired systolic and diastolic myocardial velocities of the LV measured by TDI [mean global TDI: systolic (s): 2.9 ± 0.9 vs 3.9 ± 0.7 cm/s, p < 0.05; early (e): 4.3 ± 1.5 vs 6.3 ± 1.3 cm/s, p < 0.05; late (a): 2.9 ± 0.8 vs 3.4 ± 0.8 cm/s, p < 0.05; values ± SD); SRR (s: −0.8 ± 0.1 vs −1.1 ± 0.1 s−1; e: 1.1 ± 0.2 vs 1.6 ± 0.3 s−1; a: 0.7 ± 0.1 vs 1.0 ± 0.2 s−1; all p < 0.05); and SR (−15.11 ± 2.2% vs −19.7 ± 1.9%; p < 0.05) compared to the control group. Further, elevated disease activity, measured with the ECLAM and the SLEDAI score, resulted in significantly lower values for LV longitudinal function measured by SRR and SR, but not by TDI.

Conclusion.

SLE is associated with a significant impairment of systolic and diastolic LV longitudinal function in patients without cardiac symptoms. New imaging modalities provide earlier insight into cardiovascular involvement in SLE and seem to be superior to standard echocardiography to detect subclinical myocardial disease.

The role of aspirin in cardiovascular prevention: implications of aspirin resistance

Aspirin is well recognized as an effective antiplatelet drug for secondary prevention in subjects at high risk of cardiovascular events. However, most patients receiving long-term aspirin therapy still remain at substantial risk of thrombotic events due to insufficient inhibition of platelets, specifically via the thromboxane A2 pathway. Although the exact prevalence is unknown, estimates suggest that between 5.5% and 60% of patients using this drug may exhibit a degree of "aspirin resistance," depending upon the definition used and parameters measured. To date, only a limited number of clinical studies have convincingly investigated the importance of aspirin resistance. Of these, few are of a sufficient scale, well designed, and prospective, with aspirin used at standard doses. Also, most studies do not sufficiently address the issue of noncompliance to aspirin as a frequent, yet easily preventable cause of resistance to this antiplatelet drug. This review article provides a comprehensive overview of aspirin resistance, discussing its definition, prevalence, diagnosis, and therapeutic approaches. Moreover, the clinical implications of aspirin resistance are explored in various cardiovascular disease states, including diabetes mellitus, hypertension, heart failure, and other similar disorders where platelet reactivity is enhanced.

Cilostazol attenuates MCP-1 and MMP-9 expression in vivo in LPS-administrated balloon-injured rabbit aorta and in vitro in LPS-treated monocytic THP-1 cells

Monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-9 (MMP-9) are involved in vascular inflammation. We tested the hypothesis, and explored the underlining mechanisms that cilostazol, a phosphodiesterase 3 inhibitor with antiplatelet and antithrombotic properties, inhibits lipopolysaccharide (LPS)-induced MCP-1 and MMP-9 expression. In a rabbit aorta balloon-injury model, administration of LPS increased macrophage infiltration and MCP-1 and MMP-9 expression; cilostazol supplementation prevented this phenomenon and reduced intimal hyperplasia. In contrast, the reverse zymography showed that cilostazol did not affect TIMP-1 expression in serum. In monocytic THP-1 cells, cilostazol and N6,O2'-dibutyryl-cAMP (dioctanoyl-cAMP, a cAMP analog) dose-dependently inhibited LPS-induced MCP-1 protein expression and MMP-9 activation, but did not affect the tissue inhibitor of metalloproteinase-1. Quantitative real-time polymerase chain reaction (PCR) showed that cilostazol inhibited MCP-1 and MMP-9 mRNA expression. Cilostazol significantly inhibited LPS-induced activation of p38, JNK, and nuclear factor-kappaB, and the respective inhibitors of p38 and JNK greatly reduced the level of LPS-induced MCP-1 and MMP-9, suggesting the involvement of the p38 and JNK pathways. In conclusion, cilostazol administered with LPS in vivo reduced neointimal hyperplasia and macrophage infiltration in the balloon-injured rabbit aorta; in vitro, cilostazol inhibits LPS-induced MCP-1 and MMP-9 expression. These data suggest that cilostazol may play an important role in preventing endotoxin- and injured-mediated vascular inflammation.

Autoantibody Determination in the Diagnosis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that usually develops in young women aged 18-50 years and is characterized by the presence of autoantibodies. Diagnosis is difficult as SLE is a great imitator of other diseases. When SLE is suspected clinically in a patient (involvement of two or more organ systems), an initial laboratory evaluation would be antinuclear antibody (ANA) testing. If ANA is negative, SLE is unlikely and results positive at less than 1:40 strongly argue against SLE. Other explanations for organ system involvement should be pursued. Results positive at greater than 1:40 may merit further evaluation for SLE and at times referral to a rheumatologist for a full SLE evaluation. While the American College of Rheumatology classification criteria for SLE are primarily a tool for research, they may be useful clinically, in that those patients fulfilling four or more criteria are highly likely to have SLE.

Novel cardiovascular risk factors and cardiac event predictors in female inactive systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is associated with severe and premature cardiovascular disease, which cannot be explained by traditional risk factors alone. This study aims to investigate novel cardiovascular risk factors and cardiac event predictors in inactive SLE female patients who do not have any major cardiovascular risk factors. Twenty-five inactive (SLE disease activity index score <4) SLE female patients and 22 healthy control women were studied. SLE patients with a history of diabetes mellitus, hypertension, hyperlipidemia, smoking, or coronary artery disease (CAD) were excluded. Venous blood samples were analyzed for lipid subfractions and novel cardiovascular risk factors such as lipoprotein (a), homocysteine, fibrinogen, high-sensitivity C-reactive protein (hs-CRP), and serum amyloid A (SAA) levels. Endothelial dysfunction was assessed by flow-mediated dilatation (FMD) from the brachial artery at baseline and during reactive hyperemia. SLE patients and controls were similar in terms of age (40+/-10 years vs 38+/-10 years, p = NS). No significant difference was found between the groups regarding family history of premature CAD, blood pressure, body mass index, lipoprotein (a), homocysteine, fibrinogen, SAA, apoprotein A-1 and B levels. Compared with the controls, SLE patients had higher levels of hs-CRP [median (range): 1.82 (0.02-0.98) vs 0.68 (0.02-0.35), p=0.04]. FMD was lower in SLE patients than controls (7.1+/-2.1 vs 11.4+/-1.2%, p<0.001). Increased levels of hs-CRP and decreased FMD were found in inactive SLE patients. Increased hs-CRP levels may reflect ongoing low-grade inflammation that could be a cause of impaired FMD in SLE patients. These findings suggest that SLE patients without traditional major cardiovascular risk factors may have increased risk of cardiovascular disease and future cardiac events.

Systemic lupus erythematosus in Asturias, Spain: clinical and serologic features

Asturias is an autonomous region in the north of Spain with historical and anthropologic peculiarities. In the current report, we examine the main clinical and immunologic features of 363 patients with systemic lupus erythematosus (SLE), virtually the entire population of SLE patients in Asturias. We constructed a database with the clinical and immunologic features of all patients fulfilling the American College of Rheumatology criteria, based on the review of hospital records corresponding to blood samples received for antinuclear antibodies testing since 1992. Arthritis was the most frequently observed main clinical feature and neuropathy was the rarest. Male patients had a disease more frequently characterized by serositis (p<0.05) and neurologic disorder (p<0.01) than females, while children presented malar rash (p<0.05), fever (p<0.05), and kidney involvement (p<0.01) more often than adults. Late-onset patients were characterized by lower frequencies of malar rash (p<0.01), neurologic disorder (p<0.05), alopecia (p<0.01), and lymphadenopathy (p<0.05) than young adults. Numerous direct and inverse significant associations were found among clinical and immunologic features. The most relevant significant associations were neurologic disorder with lupus anticoagulant (p<0.01); kidney involvement with serositis (p<0.01) and DNA antibodies (p<0.05); and thrombosis with DNA antibodies (p<0.05), cardiolipin antibodies (p<0.01), and lupus anticoagulant (p<0.01). A low mortality was found in our series, although kidney involvement (p<0.05) and cardiolipin antibodies (p<0.05) are factors associated with poor survival.

Clinical outcomes of systemic lupus erythematosus patients undergoing continuous ambulatory peritoneal dialysis

OBJECTIVES

The purpose of this study was to evaluate the outcome of systemic lupus erythematosus (SLE) patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

Eighteen SLE patients who had been undergoing CAPD for at least 3 months in our unit were compared with 36 other age- and gender-matched non-diabetic CAPD patients with an underlying primary chronic glomerulonephritis (CGn). The clinical outcome, infective complications, lupus activities, biochemical parameters, haemoglobin level and the use of erythropoietin were reviewed.

RESULTS

The duration of dialysis of the two studied groups was not different, with a mean of 35.4 months for the SLE group and 36.7 months for the CGn group. Before dialysis, SLE patients had a significantly lower albumin level (30.4+/-6.6 vs 35.4+/-5.59 g/dl, P<0.01), while the mean haemoglobin levels of the two groups were similar (8.5+/-1.8 g/dl for SLE vs 9.0+/-1.9 g/dl for the control group). However, the weekly dose of erythropoietin (EPO) used was significantly higher in the SLE group (6000 vs 3818 U/week, P<0.01) to maintain a similar haemoglobin level during dialysis. Regarding the infective complications, the SLE group had a higher peritonitis rate (5.7 episodes/100 patient-months vs 2.4 episodes/100 patient-months, P<0.05), and an increase in the non catheter related infection rate (6.67 episodes/100 patient-months vs 1.1 episodes/100 patient-months, P<0.001). However, no significant difference could be demonstrated in the Tenckhoff catheter exit site infection rate (2 episodes/100 vs 1.7 episode/100 patient-months). The number of patients who received a kidney transplant or required a change of mode to haemodialysis was similar among the two groups. Seven patients died during the follow-up period, and the overall mortality rate was much higher in the SLE group than in the control group (0.83/100 vs 0.15/100 patient-months, P<0.05).

CONCLUSIONS

SLE patients on CAPD have a significantly lower pre-dialysis serum albumin level and use a higher dose of Epo to achieve a comparable haemoglobin level than other non-diabetic CGn CAPD patients. They also have a poorer prognosis in terms of infective complications and mortality rate.

Knowledge-based computational search for genes associated with the metabolic syndrome

MOTIVATION

A methodology to search for genes associated with multifactorial diseases by integrating the large amount of accumulated knowledge is seriously needed. A comprehensive understanding derived from a holistic view of gene relationship structures can be gained from our proposed analysis called the cross-subspace analysis (CSA). In this analysis, gene objects are generated by machine learning using their term occurrence patterns in MEDLINE abstracts and the degree of relationship between gene objects is quantified by matching these patterns.

RESULTS

Structuralization of relationships of a set of genes was performed using CSA, which were retrieved using the terms, 'obesity', 'diabetes', 'hypertriglyceridemia' and 'hypertension' that refer to diseases comprising metabolic syndrome, on a 2D plane inferring important biomedical concepts from the gene distribution. Then, we prioritized the significance of 6131 well-annotated human genes in terms of the distance on the plane from the centroid of 'metabolic syndrome'-related genes distribution. The validity was confirmed by comparing the knowledge extracted by the ordering with existing medical knowledge.

Role of cytokines in cardiovascular diseases: a focus on endothelial responses to inflammation

Complex cellular and inflammatory interactions are involved in the progress of vascular diseases. Endothelial cells, upon exposure to cytokines, undergo profound alterations of function that involve gene expression and de novo protein synthesis. The functional reprogramming of endothelial cells by cytokines is of importance especially in patients with chronic vascular inflammation. The intercellular network of dendritic cells, T-lymphocytes, macrophages and smooth muscle cells generates a variety of stimulatory cytokines [e.g. TNF-alpha (tumour necrosis factor-alpha), IL (interleukin)-1, IL-6 and IFN-gamma (interferon-gamma)] and growth factors that promote the development of functional and structural vascular changes. High concentrations of proinflammatory cytokines increase oxidative stress, down-regulate eNOS (endothelial nitric oxide synthase) bioactivity and induce endothelial cell apoptosis. Chemoattractant cytokines [e.g. VEGF (vascular endothelial growth factor), TGF-beta1 (transforming growth factor-beta1) and IL-8] are important regulators of inflammation-induced angiogenesis and are directly modulated by nitric oxide. This review will focus on the vascular mechanisms orchestrated by cytokines and summarizes the current knowledge concerning the contribution of cytokines to cardiovascular diseases.