Elevated oxidative DNA damage in patients with coronary artery disease and its association with oxidative stress biomarkers

Differences in Levels of Mitochondrial DNA Content at Various Stages of Canine Myxomatous Mitral Valve Disease

Myxomatous mitral valve disease (MMVD) is the most common heart disease in small-breed dogs, often leading to heart failure. Oxidative stress in MMVD can harm mitochondria, decreasing their DNA content. This study assesses dogs' oxidative stress and mitochondrial DNA at different MMVD stages. Fifty-five small-breed dogs were categorized into four groups, including: A-healthy (n = 15); B-subclinical (n = 15); C-heart failure (n = 15); and D-end-stage MMVD (n = 10). Serum malondialdehyde (MDA) and mitochondrial DNA in peripheral blood were analyzed. Quantitative real-time PCR measured mitochondrial DNA, and PCR data were analyzed via the fold-change Ct method. Serum MDA levels were assessed using competitive high-performance liquid chromatography (HPLC). Mitochondrial DNA was significantly lower in group B (-0.89 ± 2.82) than in group A (1.50 ± 2.01), but significantly higher in groups C (2.02 ± 1.44) and D (2.77 ± 1.76) than B. MDA levels were notably elevated in groups B (19.07 ± 11.87 µg/mL), C (23.41 ± 12.87 μg/mL), and D (19.72 ± 16.81 μg/mL) in comparison to group A (9.37 ± 4.67 μg/mL). Nevertheless, this observed difference did not reach statistical significance. It is noteworthy that mitochondrial DNA content experiences a decline during the subclinical stage but undergoes an increase in cases of heart failure. Concurrently, oxidative stress exhibits an upward trend in dogs with MMVD. These findings collectively suggest a potential association between mitochondrial DNA, oxidative stress, and the progression of MMVD in small-breed dogs.

The usefulness of arylesterase in predicting contrast-induced nephropathy in ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention

Aim: Oxidative stress is one of the causes of contrast-induced nephropathy (CIN). Paraoxonase1 (PON1), is one of the oxidative stress markers. The most sensitive method that has been in use to measure PON1 enzyme activity is the measurement of arylesterase (AREase) activity. To explore relationship between AREase activity and CIN development. Material and Method: A total of 58 STEMI patients were included in our study. The patients were divided into two groups as CIN (+) and CIN (-). The success of AREase activity level in predicting the development of CIN was also examined by using ROC analysis. Results: Out of the study patients, 13 were CIN (+) and 45 were CIN (-). AREase activity was found to be statistically significantly lower in the CIN (+) group (875 U/L vs 819 U/L, p= 0.004). In the regression analysis, diabetes mellitus, contrast volume and AREase activity were determined as independent risk factors in the development of CIN. As a result of the ROC analysis, we concluded that the AREase activity level

Genome instability in peripheral blood lymphocytes of patients with heart failure and reduced ejection fraction

Heart failure (HF) is a complex clinical condition characterized by functional and structural defects of the myocardium, but genetic and environmental factors are considered to play an important role in the development of the disease. In the present study, we investigated the genome instability (DNA and chromosomal damage) in patients with heart failure with reduced ejection fraction (HFrEF) ≤40% and its association with risk factors. The studied population included 48 individuals, of which 29 HFrEF patients (mean age 57.41 ± 5.74 years) and 19 healthy controls (mean age 57.63 ± 6.09 years). The genetic damage index in peripheral blood lymphocytes was analyzed using the comet assay, while micronuclei frequency and nuclear division index were analyzed using the cytokinesis-block micronucleus assay. Our results showed that HFrEF patients had a significantly higher genetic damage index compared with the healthy controls (P < .001). Cytokinesis-block micronucleus assay showed that the average micronucleus frequency in peripheral blood lymphocytes of patients was significantly higher, while the nuclear division index values were significantly lower than in controls (P < .01). Using multiple linear regression analysis, pathological state, ejection fraction, creatinine, glucose, associated disease, residence, proBNP, troponin, urea, ACE-inhibitors, and length of the drug therapy were identified as predictors of DNA and/or chromosomal damage in HF patients. We can conclude that DNA and chromosomal damage was increased in patients with HF, which may be a consequence of disease and/or drug therapy.

Predictive value of oxidative, antioxidative, and inflammatory status for left ventricular systolic recovery after percutaneous coronary intervention for ST-segment elevation myocardial infarction

OBJECTIVE

This study aimed to evaluate the association between left ventricular ejection fraction recovery and the total oxidant status, total antioxidant capacity, and high-sensitivity C-reactive protein levels.

METHODS

A total of 264 ST-elevation myocardial infarction patients were classified into two groups according to baseline and 6-month follow-up left ventricular systolic function: reduced and recovery systolic function. Predictors of the recovery of left ventricular ejection fraction were determined by multivariate regression analyses.

RESULTS

Multivariable analysis indicated that oxidative status index, baseline left ventricular ejection fraction and peak creatine-kinase myocardial bundle level, and high-sensitivity C-reactive protein were independently associated with the decreased of left ventricular ejection fraction at 6-month follow-up.

CONCLUSION

Oxidative stress and inflammation parameters were detrimental to the recovery of left ventricular ejection fraction in patients with ST-elevation myocardial infarction.

TRIM21 aggravates cardiac injury after myocardial infarction by promoting M1 macrophage polarization

Macrophage polarization followed by myocardial infarction (MI) is essential for wound healing. Tripartite motif-containing protein 21 (TRIM21), a member of E3 ubiquitin ligases, is emerging as a mediator in cardiac injury and heart failure. However, its function in modulating post-MI macrophage polarization remains elusive. Here, we detected that the levels of TRIM21 significantly increased in macrophages of wild-type (WT) mice after MI. In contrast, MI was ameliorated in TRIM21 knockout (TRIM21-/-) mice with improved cardiac remodeling, characterized by a marked decrease in mortality, decreased infarct size, and improved cardiac function compared with WT-MI mice. Notably, TRIM21 deficiency impeded the post-MI apoptosis and DNA damage in the hearts of mice. Consistently, the accumulation of M1 phenotype macrophages in the infarcted tissues was significantly reduced with TRIM21 deletion. Mechanistically, the deletion of TRIM21 orchestrated the process of M1 macrophage polarization at least partly via a PI3K/Akt signaling pathway. Overall, we identify TRIM21 drives the inflammatory response and cardiac remodeling by stimulating M1 macrophage polarization through a PI3K/Akt signaling pathway post-MI.

Serum levels of vitamin A, selenium and better dietary total antioxidant capacity are related to lower oxidative DNA damage: a cross-sectional study of individuals at cardiovascular risk

The risk for cardiovascular diseases (CVR) has been associated with oxidative DNA damage, but the genetic and environmental factors involved in the antioxidant and DNA repair system contributing to this damage are unknown. The aim was to evaluate the levels of oxidative DNA damage in CVR subjects and how it is related with some genetic and nutritional factors. The cross-sectional study evaluated 136 individuals of both sexes, aged 20-59 years, with at least one cardiovascular risk factor. The global risk score was used to classify individuals at low, intermediate and high cardiovascular risk. The dietary total antioxidant capacity (DTAC) was calculated using table with FRAP values. The oxidative DNA damage was verified by the comet assay. The variants null of Glutathione-S-transferases Mu1 and Theta 1(GSTM1 and GSTT1) and rs25487 of X-Ray Repair Cross Complementing Protein 1 (XRCC1) were analyzed by real-time PCR and PCR-RFLP, respectively. The oxidative DNA damage was higher in patients with intermediate/high CVR than in patients with low CVR (p=0.01). Individuals with GSTT1/GSTM1 null genotypes or arg/gln + gln/gln genotypes of the XRCC1 (rs25487) gene showed similar levels of oxidative DNA damage compared wild genotype. Multivariate regression analysis demonstrated that oxidative DNA damage in individuals with CVR depends on serum levels of vitamin A, selenium and DTAC independently of the other factors [F(6.110)=8.213; p<0.001; R2=0.330]. These findings suggest that nutritional factors such as DTAC, vitamin A and selenium may have a protective effect against oxidative DNA damage in these individuals.

Oxidative stress and soluble receptor for advanced glycation end-products play a role in the pathophysiology of delirium after cardiac surgery

Coronary-artery bypass graft (CABG) surgery is known to improve cardiac function and decrease mortality, albeit, this method of treatment is also associated with a neuropsychiatric complications including postoperative delirium. The pathophysiology of delirium after cardiac surgery remains poorly understood. Thus, the purpose of this study was to investigate whether oxidative stress reflected by decreased preoperative and postoperative plasma antioxidant activity is independently associated with delirium after cardiac surgery. The second aim was to assess whether decreased antioxidant activity is stress-related or mediated by other pathologies such as major depressive disorder (MDD), anxiety disorders, and cognitive impairment. Furthermore, the putative relationship between pre- and postoperative soluble receptor for advanced glycation end-products (sRAGE) overexpression and plasma antioxidant capacity was evaluated. The patients cognitive status was assessed 1 day preoperatively with the use of the Mini-Mental State Examination Test and the Clock Drawing Test. A diagnosis of MDD and anxiety disorders was established on the basis of DSM-5 criteria. Blood samples for antioxidant capacity and sRAGE levels were collected both preoperatively and postoperatively. The Confusion Assessment Method for the Intensive Care Unit was used within the first 5 days postoperatively to screen for a diagnosis of delirium. Postoperative delirium was diagnosed in 34% (61 of 177) of individuals. Multivariate logistic regression analysis revealed that low baseline antioxidant capacity was independently associated with postoperative delirium development. Moreover, increased risk of delirium was observed among patients with a preoperative diagnosis of MDD associated with antioxidant capacity decreased postoperatively. According to receiver operating characteristic analysis, the most optimal cutoff values of the preoperative and postoperative antioxidant capacity that predict the development of delirium were 1.72 mM and 1.89 mM, respectively. Pre- and postoperative antioxidant capacity levels were negatively correlated with postoperative sRAGE concentration (Spearman's Rank Correlation − 0.198 and − 0.158, p < 0.05, respectively). Patients with decreased preoperative antioxidant activity and those with depressive episodes complicated with lower postoperative antioxidant activity are at significantly higher risk of delirium after cardiac surgery development. sRAGE overexpression may be considered as protective mechanism against increased oxidative stress and subsequent cell damage.

Non-mercaptalbumin is significantly associated with the coronary plaque burden and the severity of coronary artery disease

Human non-mercaptalbumin (HNA), oxidized form of serum albumin, has been reported as a useful marker in oxidative stress-related diseases; however, few reports have examined the association between HNA and the severity of coronary artery disease (CAD). The present study evaluated whether the HNA fraction is correlated with coronary artery stenosis in 140 patients considered to have a high risk of CAD or who were suspected of having acute coronary syndrome. The severity of CAD was defined by the number of stenotic coronary vessels and a severity score system (the Gensini score). HNA measurements were performed using our newly established high-performance liquid chromatography methodology. The results had shown that HNA was significantly increased in patients with three-vessel disease, compared with those without CAD or with single-vessel disease (p = 0.025), and was positively correlated with the Gensini score (ρ = 0.421, p < 0.001). A multivariate analysis showed that the number of stenotic vessels was an independent and significant factor associated with HNA (ρ = 1.246, p = 0.012). A logistic regression analysis showed that HNA was a strong predictor of multivessel CAD (odds ratio, 1.12; 95% confidence interval, 1.020–1.229; p = 0.017). These findings indicate that the measurement of HNA could be clinically practical for predicting the severity of coronary artery stenosis.

Measurement of DNA damage with the comet assay in high-prevalence diseases: current status and future directions

The comet assay is widely used in studies on genotoxicity testing, human biomonitoring and clinical studies. The simple version of the assay detects a mixture of DNA strand breaks and alkali-labile sites; these lesions are typically described as DNA strand breaks to distinguish them from oxidatively damaged DNA that are measured with the enzyme-modified comet assay. This review assesses the association between high-prevalence diseases in high-income countries and DNA damage measured with the comet assay in humans. The majority of case-control studies have assessed genotoxicity in white blood cells. Patients with coronary artery disease, diabetes, kidney disease, chronic obstructive pulmonary disease and Alzheimer's disease have on average 2-fold higher levels of DNA strand breaks compared with healthy controls. Patients with coronary artery disease, diabetes, kidney disease and chronic obstructive pulmonary disease also have 2- to 3-fold higher levels of oxidatively damaged DNA in white blood cells than controls, although there is not a clear difference in DNA damage levels between the different diseases. Case-control studies have shown elevated levels of DNA strand breaks in patients with breast cancer, whereas there are only few studies on colorectal and lung cancers. At present, it is not possible to assess if these neoplastic diseases are associated with a different level of DNA damage compared with non-neoplastic diseases.

A SIRT1 agonist reduces cognitive decline in type 2 diabetic rats through antioxidative and anti‑inflammatory mechanisms

Sirtuin 1 (SIRT1) is an NAD+‑dependent protein deacetylase that is involved in cell differentiation, aging, apoptosis, physiological rhythms, metabolic regulation, oxidative stress and numerous other important biological processes. In the present study, the ability of a sirtuin‑1 (SIRT1) agonist, SRT1720, to reduce cognitive decline in type 2 diabetes mellitus (T2DM) was investigated. Streptozotocin‑induced male Sprague‑Dawley rats were used to establish a T2DM model and the protective effect of SRT1720 and its underlying mechanisms were investigated. Body weight and fasting blood glucose (FBG) were recorded and cognitive function was measured with the Morris water maze. Levels of oxidative stress, inflammation, caspase‑3 activity and nuclear factor κB (NF‑κB) mRNA expression were detected with a series of commercial assay kits and reverse transcription‑quantitative polymerase chain reaction, respectively. Western blot analysis was performed to determine the protein expression of NF‑κB, endothelial nitric oxide synthase (eNOS), peroxisome proliferator‑activated receptor γ (PPARγ), AMP‑activated protein kinase (AMPK), heat shock 70 kDa protein (HSP70), SIRT1, nuclear factor erythroid 2‑related factor 2 (Nrf2) and heme oxygenase 1 (HO‑1). The results revealed that SRT1720 significantly increased body weight, decreased FBG, improved cognitive function and reduced the levels of proteins associated with oxidative stress and inflammation damage in T2DM rats. Additionally, SRT1720 significantly decreased NF‑κB p65 mRNA expression and increased eNOS and PPARγ expression. SRT1720 significantly reduced caspase‑3 activity and HSP70 protein expression, and increased p‑AMPK, SIRT1, Nrf2 and HO‑1 protein expression. Collectively, the results indicate that SRT1720 may reduce cognitive decline in T2DM rats through antioxidative and anti‑inflammatory action via NF‑κB and AMPK‑dependent mechanisms.