Anti-oxidized low-density lipoprotein antibodies in chronic heart failure

Oxidative Status in Adult Anorexia Nervosa Patients and Healthy Controls—Results from a Cross-Sectional Pilot Study

Oxidative stress describes an imbalance of reactive oxygen species (ROS) and antioxidative defence systems. Recently, the consequences of oxidative stress have become a central field of research and have been linked to the genesis of multiple psychiatric diseases. Some oxidative stress parameters have not been investigated before in anorexia nervosa (AN) patients, including the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) and polyphenols (PPm). In this cross-sectional pilot study, we evaluated these markers together with total peroxides (TOC), antioxidative capacity (TAC), endogenous peroxidase activity (EPA) and antibodies against oxidized LDL (oLAb) in serum samples of 20 patients with AN compared to 20 healthy controls. The antioxidative capacity was significantly decreased in AN patients, with a mean TAC of 1.57 mmol/L (SD: ±0.62); t (34) = −2.181, p = 0.036) compared to HC (mean = 1.91 mmol/L (SD: ±0.56), while the other investigated parameters were not significantly different between the two groups. In AN patients, TAC correlated with EPA (r_sp = −0.630, p = 0.009). This study suggests that there is an antioxidative deficiency in AN patients. In this respect, there is a demand for interventional studies to determine whether antioxidants can be used as add-on therapy in the treatment of AN.

Autoimmune Rheumatic Diseases and Vascular Function: The Concept of Autoimmune Atherosclerosis

Autoimmune rheumatic diseases (AIRDs) with unknown etiology are increasing in incidence and prevalence. Up to 5% of the population is affected. AIRDs include rheumatoid arthritis, system lupus erythematosus, systemic sclerosis, and Sjögren's syndrome. In patients with autoimmune diseases, the immune system attacks structures of its own body, leading to widespread tissue and organ damage, which, in turn, is associated with increased morbidity and mortality. One third of the mortality associated with autoimmune diseases is due to cardiovascular diseases. Atherosclerosis is considered the main underlying cause of cardiovascular diseases. Currently, because of finding macrophages and lymphocytes at the atheroma, atherosclerosis is considered a chronic immune-inflammatory disease. In active inflammation, the liberation of inflammatory mediators such as tumor necrotic factor alpha (TNFa), interleukine-6 (IL-6), IL-1 and other factors like T and B cells, play a major role in the atheroma formation. In addition, antioxidized, low-density lipoprotein (LDL) antibodies, antinuclear antibodies (ANA), and rheumatoid factor (RF) are higher in the atherosclerotic patients. Traditional risk factors like gender, age, hypercholesterolemia, smoking, diabetes mellitus, and hypertension, however, do not alone explain the risk of atherosclerosis present in autoimmune diseases. This review examines the role of chronic inflammation in the etiology-and progression-of atherosclerosis in autoimmune rheumatic diseases. In addition, discussed here in detail are the possible effects of autoimmune rheumatic diseases that can affect vascular function. We present here the current findings from studies that assessed vascular function changes using state-of-the-art techniques and innovative endothelial function biomarkers.

Anti-Ro and Concomitant Anti-La Autoantibodies Strongly Associated With Anti-oxLDL or Anti-Phospholipid Antibody in Systemic Lupus Erythematosus

BACKGROUND

Premature atherosclerosis is observed in systemic lupus erythematosus (SLE). Oxidative modification of LDL is associated with atherosclerotic plaque formation.

OBJECTIVES

We hypothesized that anti-oxidized LDL (oxLDL) and anti-phospholipid (APL) in SLE sera would segregate with specific antibody subsets, and that anti-oxLDL antibodies will linger in circulation over an extended period.

PATIENTS AND METHODS

Sixty-seven SLE and control subjects and two SLE subjects with sera collected longitudinally for 13 years were tested for anti-oxLDL and IgG/IgM/IgA APL antibodies.

RESULTS

Anti-oxLDL ELISA values above 57.48 Activity Units (AcU) (means of normals + 3 standard deviations) and anti-IgG/IgM/IgA APL above 10 phospholipid units (PU) were considered positive. Average anti-oxLDL was 67.7 ± 50.5 AcU in SLE compared to 23.9 ± 11.19 AcU in normals (P = 0.018). Ten out of ten subjects with anti-Ro60/anti-La/anti-Ro52 antibodies had highly significant (P < 0.0001) anti-oxLDL (127.29 ± 45.67 AcU) and IgG APL (18.66 ± 7.4 PU) (P < 0.02). Subjects with anti-RNP were positive for anti-oxLDL (P < 0.002), but subjects with anti-Ro60/anti-Ro52 and subjects negative for extractable nuclear antigen (ENA) antibody were not positive for anti-oxLDL. Anti-oxLDL/anti-IgG APL remained significantly elevated in two patients studied longitudinally. Interestingly, one developed anti-oxLDL/anti-APL antibodies several years before anti-Ro60 development.

CONCLUSIONS

Presence of antibodies against Ro RNP and La, and RNP is highly associated with developing anti-oxLDL and APL antibodies in SLE. It will be clinically important to see if cardiovascular events occur in these SLE subsets having elevated anti-oxLDL and APL antibodies. Emergence of anti-oxLDL/IgG APL before anti-Ro60 over time in a patient indicates that these antibodies could not be cross-reactive in nature, at least in this particular patient.

Oxidized Low-density Lipoprotein (ox-LDL) Cholesterol Induces the Expression of miRNA-223 and L-type Calcium Channel Protein in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia causing high morbidity and mortality. While changing of the cellular calcium homeostasis plays a critical role in AF, the L-type calcium channel α1c protein has suggested as an important regulator of reentrant spiral dynamics and is a major component of AF-related electrical remodeling. Our computational modeling predicted that miRNA-223 may regulate the CACNA1C gene which encodes the cardiac L-type calcium channel α1c subunit. We found that oxidized low-density lipoprotein (ox-LDL) cholesterol significantly up-regulates both the expression of miRNA-223 and L-type calcium channel protein. In contrast, knockdown of miRNA-223 reduced L-type calcium channel protein expression, while genetic knockdown of endogenous miRNA-223 dampened AF vulnerability. Transfection of miRNA-223 by adenovirus-mediated expression enhanced L-type calcium currents and promoted AF in mice while co-injection of a CACNA1C-specific miR-mimic counteracted the effect. Taken together, ox-LDL, as a known factor in AF-associated remodeling, positively regulates miRNA-223 transcription and L-type calcium channel protein expression. Our results implicate a new molecular mechanism for AF in which miRNA-223 can be used as an biomarker of AF rheumatic heart disease.

The Number of GT(n) Repeats in the Hemeoxygenase-1 Gene Promoter is Increased in Pediatric Heart Failure but is Unrelated to Renal, Antioxidant and Anti-inflammatory Markers

Products of hemeoxygenase (HO)-1 have anti-inflammatory and antioxidant functions. The HO-1 promoter has a variable number of GT(n) repeats: A low number (n < 23) is associated with high transcriptional activity in response to oxidative stress. We hypothesized that the frequency of GT(n) repeats in pediatric heart failure (HF) reflects plasma biomarkers of different disease processes: the soluble receptor for advance glycation end products (sRAGE, marking cellular activation), oxLDL (oxidative stress), NGAL (impaired renal function), HIF-1α (hypoxia) and hsCRP (inflammation). Sixty HF children [aged 4-14 years, 30 with HF due to idiopathic dilated cardiomyopathy (IDCM), 30 due to chronic renal failure (CRF)] were compared to 20 healthy controls (HC). Leukocyte HO-1 GT(n) repeats were determined by PCR, plasma markers by ELISA or nephelometry. The number of GT(n) repeats in the HF patients was higher than the number of repeats in the controls, with no difference between the patient groups (p < 0.001). sRAGE, oxLDL, HIF-1α, NGAL and hsCRP were higher in both HF groups compared to HC (all p < 0.01). IDCM had higher sRAGEs and HIF-1α compared to CRF patients (p < 0.01). NGAL was higher in CRF compared to IDCM (p < 0.01). None of the plasma/serum markers correlated with the number of GT(n) repeats in any group. The number of HO-1 promoter GT(n) polymorphism is increased in both IDCM and CRF children with HF, but is unrelated to plasma markers of different pathological processes. This casts doubts on the clinical value of the number of GT(n) repeats in pediatric HF.

Ketogenic diet in epileptic children: impact on lipoproteins and oxidative stress

OBJECTIVES

Ketogenic diet (KD) is an important therapy used in the control of drug-refractory seizures. The major goal of this review is to update the knowledge about the adverse effects of KD on lipoproteins, lipid profile, and cardiometabolic risk.

METHODS

Articles on the effect of the KD on plasma lipoproteins of children and adolescents with refractory epilepsy, which were published in the past 15 years and indexed in the PubMed and MedLine databases, were included.

RESULTS

Dyslipidemia was recurrent in children, and adolescents treated with KD. Evidence suggests that hypercholesterolemia promotes structural modifications in low-density lipoprotein particles. Such modifications possibly favor oxidative processes and contribute to changes in the size of lipoproteins, particularly related to small and denser LDL. However, oxidative modifications in LDL of children on KD are not described in the literature.

DISCUSSION

The positive effects of KD on the health of children and adolescents with refractory epilepsy are unquestionable. Conversely, this positive role is associated with significant and negative changes in lipid metabolism. Moreover, the positive effects are possibly related to oxidative reactions and unbalance of antioxidants that can contribute to an increased cardiometabolic risk. Therefore, this review invites clinicians and researchers to investigate the lipid and oxidative metabolism in their clinical practice and trials, respectively.

Increased levels of anti-heat-shock protein 60 (anti-Hsp60) indicate endothelial dysfunction, atherosclerosis and cardiovascular diseases in patients with mixed connective tissue disease

Heat-shock protein 60 (Hsp60) has been shown to provoke inflammation, and anti-Hsp60 may facilitate the development of atherosclerosis. In this study, we have investigated 30 patients with mixed connective tissue disease (MCTD) and assessed anti-Hsp60 and their relationship to cardiovascular diseases (CVD). Out of 30 patients with MCTD, 15 had CVDs. Anti-Hsp60 antibody was determined by enzyme-linked immunosorbent assay. Since endothelial dysfunction and accelerated atherosclerosis are characteristic to MCTD, a wide array of MCTD-, endothelial dysfunction- and CVD-associated parameters was investigated: serum lipid levels, paraoxonase activity (PON1), rich nuclear ribonucleoprotein U1 (anti-U1RNP), anti-endothelial cell antibodies, anti-cardiolipin and anti-β2-glycoprotein I antibody isotypes (anti-CL and anti-β2GPI), endothelin-1 (ET-1) levels, also intima-media thickness (IMT), a quantitative indicator of atherosclerosis. In MCTD, anti-Hsp60 antibody levels were significantly higher than in healthy individuals (p < 0.02). MCTD patients with CVD had significantly higher levels of anti-Hsp60 compared to MCTD without CVD (p = 0.001). Patients with MCTD had significantly lower high-density lipoprotein cholesterol (p = 0.02) and PON activity (p < 0.001), and significantly increased systolic (p < 0.0002) and diastolic (p < 0.001) blood pressure compared to healthy individuals. Anti-U1RNP levels (p < 0.002) and IMT were higher in patients compared to controls (p = 0.002). The CVD-positive MCTD patients had increased anti-Hsp60 (p < 0.0013), anti-CL IgG (p = 0.0005), ET-1 serum concentration (p < 0.05) and IMT levels (p < 0.001) compared to MCTD patients without CVD. Anti-Hsp60 showed a strong correlation with anti-oxLDL (r = 0.36, p = 0.01) and serum ET-1 (r = 0.62, p < 0.001) and negative correlation with PON activity (r = -0.47, p = 0.01). Anti-Hsp60 indicates endothelial injury, CVD, and can function as a novel atherosclerotic risk factor, also a valuable diagnostic marker in patients with MCTD.

Protective effect of soybeans as protein source in the diet against cadmium-aorta redox and morphological alteration

We investigated the effects of cadmium exposition on thoracic aorta redox status and morphology, and the putative protective effect of soybeans in the diet. Male Wistar rats were separated into 6 groups: 3 fed with a diet containing casein and 3 containing soybeans, as protein source. Within each protein group, one was given tap water (control) and the other two tap water containing 15 and 100 ppm of Cd(2+), respectively, for two months. In rats fed with casein diet, 15 ppm of Cd induced an increase of thiobarbituric acid-reactive substances (TBARS), and of the catalase (CAT) and glutathione peroxidase (GPx) activities, which were even higher with 100 ppm of Cd(2+), in aorta. Also, 100 ppm Cd(2+) exposure increased superoxide dismutase (CuZnSOD) activity; CAT, GPX, SOD, Nrf2 and metallothioneine II mRNA expressions and CAT, GPx and NOX-2 protein levels, compared with control. Aorta endothelial and cytoplasmic alterations were observed. However, with the soybeans diet, 15 and 100 ppm of Cd(2+) did not modify TBARS levels; CAT, GPX and Nrf2 mRNA expressions; CAT, GPx and NOX-2 protein; and the aorta morphology, compared with control. The soybean diet attenuates the redox changes and protects against morphological alterations induced, in a dose-dependent way, by Cd in aorta.