Differences in oxidative stress markers based on the aetiology of heart failure: Comparison of oxidative stress in patients with and without coronary artery disease

The effects of IGF-1 and IGFBP-2 treatments on the atherosclerosis in the aorta and the coronary arteries of the high cholesterol diet-fed rabbits

Several studies have demonstrated suppression of aortic atherosclerosis by insulin like growth factor-1 (IGF-1) in hypercholesterolemic rabbits. Though a recent study has reported that IGF-1 exerts anti-atherogenic effects in coronary arteries, the mechanisms of IGF-1 in coronary arteries need to be further verified. Studies about insulin like growth factor binding protein-2 (IGFBP-2) in atherosclerosis are rarely. The objective of this study is to examine the effects of IGF-1 and IGFBP-2 on the atherosclerosis development in the aorta and coronary arteries of the high-cholesterol diet (HCD)-fed rabbits. New Zealand white rabbits were fed either normal chow (n = 5) or a diet containing 1.0 % cholesterol (n = 18) for 12 weeks. Cholesterol-fed rabbits were given IGF-1 or IGFBP-2 or saline intravenously (each n = 6) for 10 weeks. The results revealed that IGF-1 decreased total cholesterol (TC) and low-density lipoprotein (LDL) levels (p < 0.05), whereas IGFBP-2 did not. IGF-1 significantly attenuated atherosclerotic lesions and reduced accumulated macrophages within the coronary artery plaques, whereas IGFBP-2 deteriorated these changes. Moreover, IGF-1 reduced serum platelet-activating factor acetylhydrolase levels, C reactive protein (CRP), and inhibited the protein expression levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). IGFBP-2 elevated serum 8-hydroxy-2'-deoxyguanosine levels, CRP, and promoted the protein expression levels of TNF-α and IL-6. In conclusion, IGF-1 can substantially suppress plaque formation in coronary arteries with a marked inhibition of macrophage accumulation likely via its anti-inflammatory properties, whereas IGFBP-2 plays an opposite effect on atherosclerosis. The present study highlighted a theoretical basis for pharmacological treatment of atherosclerosis.

Albumin Redox Modifications Promote Cell Calcification Reflecting the Impact of Oxidative Status on Aortic Valve Disease and Atherosclerosis

Calcific aortic valve disease (CAVD) and coronary artery disease (CAD) are related cardiovascular diseases in which common mechanisms lead to tissue calcification. Oxidative stress plays a key role in these diseases and there is also evidence that the redox state of serum albumin exerts a significant influence on these conditions. To further explore this issue, we used multimarker scores (OxyScore and AntioxyScore) to assess the global oxidative status in patients with CAVD, with and without CAD, also evaluating their plasma thiol levels. In addition, valvular interstitial cells were treated with reduced, oxidized, and native albumin to study how this protein and its modifications affect cell calcification. The differences we found suggest that oxidative status is distinct in CAVD and CAD, with differences in redox markers and thiol levels. Importantly, the in vitro interstitial cell model revealed that modified albumin affects cell calcification, accelerating this process. Hence, we show here the importance of the redox system in the development of CAVD, emphasizing the relevance of multimarker scores, while also offering evidence of how the redox state of albumin influences vascular calcification. These data highlight the relevance of understanding the overall redox processes involved in these diseases, opening the door to new studies on antioxidants as potential therapies for these patients.

Leukocyte 8-hydroxy-2'-deoxyguanosine as an oxidative stress marker to predict cardiovascular events and death in chronic hemodialysis patients

BACKGROUND

Hemodialysis patients have a markedly increased risk of cardiovascular (CV) morbidity and mortality. Oxidative stress plays a pathogenic role in the progression of atherosclerosis and CV disease among chronic hemodialysis patients. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) content in leukocyte deoxyribonucleic acid (DNA) has been shown as a sensitive and well-known biomarker of oxidant-induced DNA damage in chronic hemodialysis patients.

METHODS

We conducted a retrospective cohort study to investigate the association of leukocyte 8-OHdG and CV events and deaths in patients of chronic hemodialysis. In this study, 217 chronic hemodialysis patients were recruited from 2016 to 2021. The 8-OHdG content of leukocyte DNA was measured by a high-performance liquid chromatography electrochemical detection method. Study outcomes were CV events as well as CV and all-cause deaths. The patients were followed until May 2021.

RESULTS

The median follow-up period was 34.8 months. At the end of May 2021, 57 first CV events and 89 all-CV events occurred. Among the first and all CV events, 17 (29.8%) and 32 (36.0%) were fatal, respectively. Multivariate Cox regression analysis showed per 1/10 5 dG increment in leukocyte 8-OHdG values increased risk of CV events (adjusted hazard ratio [aHR], 1.19; 95% CI, 1.10-1.41; p < 0.001), CV death (aHR, 1.27; 95% CI, 1.03-1.72; p = 0.034), and all-cause death (aHR, 1.11; 95% CI, 1.01-1.30; p = 0.038).

CONCLUSION

This is the first study to demonstrate that oxidative stress assessed by 8-OHdG levels of leukocyte DNA predicted CV events as well as CV and all-cause deaths among chronic hemodialysis patients.

Possible implication of estrogenic compounds on heart disease in menopausal women

Epidemiological studies imply there is a higher risk of cardiovascular disease in menopausal women. Some explanations suggest a lack of estrogens as the cause, but estrogens do not disappear completely and are just transformed into different products called estrogenic degradation metabolites (EDMs). When estrogens are metabolized, reactive oxygen species (ROS) increase, causing DNA damage and increasing oxidative stress. These conditions are associated to neurodegenerative diseases and different types of cancer. However, their effect on the cardiovascular system remains unknown. This paper compares estrogenic metabolite levels in serum from post-menopausal women with cardiovascular risk (CAC>1) and with establish cardiovascular disease (CVD), against levels in healthy women (Ctrl). Sample sera were obtained from the Genetics of Atherosclerotic Disease (GEA) Mexican Study. Serum levels of eleven estrogenic metabolites were quantified by High performance liquid chromatography (HPLC) and oxidative stress markers such as ROS, lipoperoxidation levels (TBARS), total antioxidant capacity (TAC), super oxide dismutase activity (SOD) and cytokine levels were evaluated. 8-hydroxy-2-deoxyguanosine (8-OHdG) was also determined as a marker of nuclear damage.There were significant differences between serum levels of some EDMs in CAC> 1 and CVD vs. serum levels in Ctrl women. Results also revealed an increase in oxidative stress and a diminished capacity to manage oxidative stress. These findings provide an overview, and suggest that some estrogenic metabolites may be associated with an increased risk of CVD in menopausal women. However, additional studies are needed to evaluate the impact of these EDMs directly on cardiovascular function.

The Relationship between Oxidative Stress and Subjective Sleep Quality in People with Coronary Artery Disease

Background: (1) Sleep disorders are prevalent in coronary artery disease (CAD) patients and predict cardiac events and prognosis. While increased oxidative stress (OS) has been associated with sleep disorders, less is known about its relationship with sleep quality. Similarly, little is known of how this relationship might change with exercise, which can improve sleep quality. Factors of sleep quality, such as sleep duration and disturbances, are also important as they predict cardiovascular diseases better than a global score alone. This study investigated whether OS was associated with self-rated sleep quality and its factors before and after completing a 24-week exercise intervention. (2) Methods: CAD patients undergoing an exercise program were recruited. OS was measured at baseline by the concentrations of early- (lipid hydroperoxides, LPH) and late-stage (8-isoprostane, 8-ISO) lipid peroxidation products and their ratio. Sleep quality was measured by the self-reported Pittsburgh Sleep Quality Index (PSQI) instrument at baseline and termination. Three sleep factors—perceived sleep quality, sleep efficiency, and daily disturbances—were derived from the PSQI. (3) Results: Among CAD patients (n = 113, 85.0% male, age = 63.7 ± 6.4 years, global PSQI = 5.8 ± 4.0), those with poor sleep (PSQI ≥ 5) had higher baseline 8-ISO levels (F(1, 111) = 6.212, p = 0.014, η_p² = 0.053) compared to those with normal sleep. Concentrations of LPH (F(1, 105) = 0.569, p = 0.453, η_p² = 0.005) and 8-ISO/LPH ratios (F(1, 105) = 2.173, p = 0.143, η_p² = 0.020) did not differ between those with poor sleep and normal sleep. Among factors, perceived sleep quality was associated with 8-ISO and 8-ISO/LPH, and daily disturbances were associated with 8-ISO. (4) Conclusions: A marker of late-stage lipid peroxidation is elevated in CAD patients with poor sleep and associated with daily disturbances, but not with other factors or with sleep quality and its factors after exercise intervention.

Exercise-Induced Regulation of Redox Status in Cardiovascular Diseases: The Role of Exercise Training and Detraining

Although low levels of reactive oxygen species (ROS) are beneficial for the organism ensuring normal cell and vascular function, the overproduction of ROS and increased oxidative stress levels play a significant role in the onset and progression of cardiovascular diseases (CVDs). This paper aims at providing a thorough review of the available literature investigating the effects of acute and chronic exercise training and detraining on redox regulation, in the context of CVDs. An acute bout of either cardiovascular or resistance exercise training induces a transient oxidative stress and inflammatory response accompanied by reduced antioxidant capacity and enhanced oxidative damage. There is evidence showing that these responses to exercise are proportional to exercise intensity and inversely related to an individual’s physical conditioning status. However, when chronically performed, both types of exercise amplify the antioxidant defense mechanism, reduce oxidative stress and preserve redox status. On the other hand, detraining results in maladaptations within a time-frame that depends on the exercise training intensity and mode, as high-intensity training is superior to low-intensity and resistance training is superior to cardiovascular training in preserving exercise-induced adaptations during detraining periods. Collectively, these findings suggest that exercise training, either cardiovascular or resistance or even a combination of them, is a promising, safe and efficient tool in the prevention and treatment of CVDs.

Mitochondrial reactive oxygen species generation in blood cells is associated with disease severity and exercise intolerance in heart failure patients

Systemic oxidative stress plays a key role in the development of chronic heart failure (CHF). We tested the hypothesis that mitochondrial reactive oxygen species (ROS) generation in circulating peripheral blood mononuclear cells (PBMCs) contributes to CHF progression. A total of 31 patients who had a history of hospital admission due to worsening HF were enrolled and grouped as having either mild CHF defined as New York Heart Association (NYHA) functional class I-II or moderate-to-severe CHF defined as NYHA functional class III. ROS levels in PBMC mitochondria were significantly increased in CHF patients with NYHA functional class III compared to those with NYHA functional class I-II, accompanied by impaired mitochondrial respiratory capacity in PBMCs. ROS generation in PBMC mitochondria was positively correlated with urinary 8-hydroxydeoxyguanosine, a systemic oxidative stress marker, in CHF patients. Importantly, mitochondrial ROS generation in PBMCs was directly correlated with plasma levels of B-type natriuretic peptide, a biomarker for severity of HF, and inversely correlated with peak oxygen uptake, a parameter of exercise capacity, in CHF patients. The study showed that ROS generation in PBMC mitochondria was higher in patients with advanced CHF, and it was associated with disease severity and exercise intolerance in CHF patients.

Comparison of Oxidative Stress Parameters in Heart Failure Patients Depending on Ischaemic or Nonischaemic Aetiology

Background

Abnormalities in the oxidative and antioxidant states causing oxidative stress were both found in heart failure (HF) of various aetiologies and atherosclerosis.

Aim of Study

The goals of the study were as follows: comparison of oxidative stress parameters (OSP) in ischaemic cardiomyopathy (ICM) (n = 479) and nonischaemic cardiomyopathy (nICM) (n = 295) patients; assessment of the relationships of OSP with functional capacity (NYHA class), maximal oxygen consumption (max.O2), left ventricle ejection fraction (LVEF), and NT-proBNP concentration; and determination of the mutual relations of OSP in subgroups of patients with ICM and n-ICM.

Methods

Serum concentrations of total antioxidant capacity (TAC), total oxidant status (TOS), uric acid (UA), bilirubin, albumin, protein sulfhydryl groups (PSH), and malondialdehyde (MDA) were measured. The oxidative stress index (OSI) and MDA/PSH ratio were calculated.

Results

Higher concentrations of TAC (1.14 vs 1.11 mmol/l; p < 0.001) and MDA (1.80 vs 1.70 μmol/l; p < 0.05) and higher MDA/PSH ratios (0.435 vs 0.358; p < 0,001) were observed in ICM than in nICM patients. Simultaneously, lower values of the OSI index (4.27 vs 4.6; p < 0, 05), PSH (4.10 vs 4.75 μmol/g of protein; p < 0,001), and bilirubin (12.70 vs 15.40 μmol/l; p < 0,001) concentrations were indicated in ICM patients. There were no differences in TOS, UA, and albumin between the examined groups. The NYHA class and VO2max correlate with MDA, bilirubin, and albumin in both groups, while with UA only in the ICM group. Correlations between the NYHA class, VO2max, and PSH were indicated in nICM. The association of LVEF with UA, bilirubin, and albumin has been demonstrated in the ICM group. The study showed negative correlations between TAC, MDA, and PSH and positive between TAC and MDA in both groups. In ICM patients, MDA positively correlated with UA. A negative correlation between PSH and concentrations of UA and bilirubin was expressed only in the nICM group.

Conclusion

The obtained results confirm the relationship between the severity of HF and oxidative stress. The mechanisms of oxidative stress and antioxidant defence are partially different in the ICM and the nICM patients.

Potential application of the oxidative nucleic acid damage biomarkers in detection of diseases

Reactive oxygen species (ROS) are generated after exposure to harmful environmental factors and during normal cellular metabolic processes. The balance of the generating and scavenging of ROS plays a significant role in living cells. The accumulation of ROS will lead to oxidative damage to biomolecules including nucleic acid. Although many types of oxidative nucleic acid damage products have been identified, 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoG) has been commonly chosen as the biomarkers of oxidative damage to DNA and RNA, respectively. It has been demonstrated that oxidative damage to nucleic acid is an initiator in pathogenesis of numerous diseases. Thus, oxidative nucleic acid damage biomarkers have the potential to be utilized for detection of diseases. Herein, we reviewed the relationship of oxidative nucleic acid damage and development of various diseases including cancers (colorectal cancer, gastrointestinal cancer, breast cancer, lung cancer, epithelial ovarian carcinoma, esophageal squamous cell carcinoma), neurodegenerative disorders and chronic diseases (diabetes and its complications, cardiovascular diseases). The potential of oxidative nucleic acid damage biomarkers for detection of diseases and drug development were described. Moreover, the approaches for detection of these biomarkers were also summarized.

Redox theory of aging: implications for health and disease

Genetics ultimately defines an individual, yet the phenotype of an adult is extensively determined by the sequence of lifelong exposures, termed the exposome. The redox theory of aging recognizes that animals evolved within an oxygen-rich environment, which created a critical redox interface between an organism and its environment. Advances in redox biology show that redox elements are present throughout metabolic and structural systems and operate as functional networks to support the genome in adaptation to environmental resources and challenges during lifespan. These principles emphasize that physical and functional phenotypes of an adult are determined by gene-environment interactions from early life onward. The principles highlight the critical nature of cumulative exposure memories in defining changes in resilience progressively during life. Both plasma glutathione and cysteine systems become oxidized with aging, and the recent finding that cystine to glutathione ratio in human plasma predicts death in coronary artery disease (CAD) patients suggests this could provide a way to measure resilience of redox networks in aging and disease. The emerging concepts of cumulative gene-environment interactions warrant focused efforts to elucidate central mechanisms by which exposure memory governs health and etiology, onset and progression of disease.

The epigenetic landscape related to reactive oxygen species formation in the cardiovascular system

Cardiovascular diseases are among the leading causes of death worldwide. Reactive oxygen species (ROS) can act as damaging molecules but also represent central hubs in cellular signalling networks. Increasing evidence indicates that ROS play an important role in the pathogenesis of cardiovascular diseases, although the underlying mechanisms and consequences of pathophysiologically elevated ROS in the cardiovascular system are still not completely resolved. More recently, alterations of the epigenetic landscape, which can affect DNA methylation, post-translational histone modifications, ATP-dependent alterations to chromatin and non-coding RNA transcripts, have been considered to be of increasing importance in the pathogenesis of cardiovascular diseases. While it has long been accepted that epigenetic changes are imprinted during development or even inherited and are not changed after reaching the lineage-specific expression profile, it becomes more and more clear that epigenetic modifications are highly dynamic. Thus, they might provide an important link between the actions of ROS and cardiovascular diseases. This review will provide an overview of the role of ROS in modulating the epigenetic landscape in the context of the cardiovascular system.

LINKED ARTICLES

This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

8-Hydroxy-2-deoxyguanosine levels and heart failure: A systematic review and meta-analysis of the literature

BACKGROUND AND AIMS

The generation of reactive oxygen species (ROS) plays an important role in the etiology of several pathological conditions. High levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), a biomarker of oxidative damage of DNA, have been found in patients with heart failure (HF). We performed a meta-analysis of the literature to investigate the association between 8-OHdG levels and HF.

METHODS AND RESULTS

A systematic search was performed in the PubMed, Web of Science, Scopus, EMBASE databases and studies evaluating 8-OHdG levels in HF patients and controls were included. Differences between cases and controls were expressed as standard mean difference (SMD) or mean difference (MD) with pertinent 95% confidence intervals (95%CI). Impact of clinical and demographic features on effect size was assessed by meta-regression. Six studies (446 HF patients and 140 controls) were included in the analysis. We found that HF patients showed higher 8-OHdG levels than controls (SMD:0.89, 95%CI: 0.68, 1.10). The difference was confirmed both in studies in which 8-OHdG levels were assessed in urine (MD:6.28 ng/mg creatinine, 95%CI: 4.01, 8.56) and in blood samples (MD:0.36 ng/ml, 95%CI: 0.04, 0.69). Interestingly, 8-OHdG levels progressively increased for increasing New York Heart Association (NYHA) class. Meta-regression models showed that none of clinical and demographic variables impacted on the difference in 8-OHdG levels among HF patients and controls.

CONCLUSIONS

8-OHdG levels are higher in HF patients HF than in controls, with a progressive increase for increasing NYHA class. However, larger prospective studies are needed to test 8-OHdG as a biomarker of HF severity and progression.

8-Hydroxy-2-Deoxyguanosine Levels and Cardiovascular Disease: A Systematic Review and Meta-Analysis of the Literature

SIGNIFICANCE

8-Hydroxy-2-deoxyguanosine (8-OHdG) is generated after the repair of ROS-mediated DNA damages and, thus, is one of the most widely recognized biomarkers of oxidative damage of DNA because guanosine is the most oxidized among the DNA nucleobases. In several pathological conditions, high urinary levels of oxidized DNA-derived metabolites have been reported (e.g., cancer, atherosclerosis, hypertension, and diabetes).

RECENT ADVANCES

Even if published studies have shown that DNA damage is significantly associated with the development of atherosclerosis, the exact role of this damage in the onset and progression of this pathology is not fully understood, and the association of oxidative damage to DNA with cardiovascular disease (CVD) still needs to be more extensively investigated. We performed a meta-analysis of the literature to investigate the association among 8-OHdG levels and CVD.

CRITICAL ISSUES

Fourteen studies (810 CVD patients and 1106 controls) were included in the analysis. We found that CVD patients showed higher 8-OHdG levels than controls (SMD: 1.04, 95%CI: 0.61, 1.47, p < 0.001, I(2) = 94%, p < 0.001). The difference was confirmed both in studies in which 8-OHdG levels were assessed in urine (MD: 4.43, 95%CI: 1.71, 7.15, p = 0.001) and in blood samples (MD: 1.42, 95%CI: 0.64, 2.21, p = 0.0004). Meta-regression models showed that age, hypertension, and male gender significantly impacted on the difference in 8-OHdG levels among CVD patients and controls.

FUTURE DIRECTIONS

8-OHdG levels are higher in patients with CVD than in controls. However, larger prospective studies are needed to test 8-OHdG as a predictor of CVD.

Analysis of oxidative stress expressed by urinary level of biopyrrins and 8-hydroxydeoxyguanosine in patients with chronic schizophrenia

AIMS

Previous studies have supported the claim that psychological stress induces the production of reactive oxygen species. Several authors have suggested that patients with psychiatric disorders show high levels of oxidative stress markers. We examined different oxidative stress markers in patients with chronic schizophrenia.

METHODS

This study included 29 patients with chronic schizophrenia and 30 healthy volunteers. The concentration of urinary biopyrrins and 8-hydroxydeoxyguanosine (8-OHdG), as measured by enzyme-linked immunosorbent assay, were normalized to the urinary concentration of creatinine. Psychiatric symptoms were assessed by the administration of the Brief Psychiatric Rating Scale (BPRS).

RESULTS

The concentration of biopyrrins in patients with chronic schizophrenia was significantly higher when compared with healthy volunteers. The correlation between biopyrrin level and the duration of illness was highly significant. There were no significant differences in the levels of urinary 8-OHdG between the two groups. In schizophrenic patients, the level of urinary biopyrrins showed correlations with BPRS scores, while the level of urinary 8-OHdG did not show correlations with BPRS.

CONCLUSIONS

Urinary biopyrrins are increased in patients with chronic schizophrenia while urinary 8-OHdG is not increased. These findings suggest that patients with chronic schizophrenia are under the condition of certain oxidative stresses.

Microfluidic tool based on the antibody-modified paramagnetic particles for detection of 8-hydroxy-2'-deoxyguanosine in urine of prostate cancer patients

Guanosine derivatives are important for diagnosis of oxidative DNA damage including 8-hydroxy-2'-deoxyguanosine (8-OHdG) as one of the most abundant products of DNA oxidation. This compound is commonly determined in urine, which makes 8-OHdG a good non-invasive marker of oxidation stress. In this study, we optimized and tested the isolation of 8-OHdG from biological matrix by using paramagnetic particles with an antibody-modified surface. 8-OHdG was determined using 1-naphthol generated by alkaline phosphatase conjugated with the secondary antibody. 1-Naphthol was determined by stopped flow injection analysis (SFIA) with electrochemical detector using a glassy carbon working electrode and by stationary electrochemical detection using linear sweep voltammetry. A special modular electrochemical SFIA system which needs only 10  μL of sample including working buffer for one analysis was completely designed and successfully verified. The recoveries in different matrices and analyte concentration were estimated. Detection limit (3 S/N) was estimated as 5  pg/mL of 8-OHdG. This method promises to be very easily modified to microfluidic systems as "lab on valve". The optimized method had sufficient selectivity and thus could be used for determination of 8-OHDG in human urine and therefore for estimation of oxidative DNA damage as a result of oxidation stress in prostate cancer patients.