The Characteristics and Roles of Advanced Oxidation Protein Products in Atherosclerosis

Vitamin D in Type 2 Diabetes and Its Correlation With Heat Shock Protein 70, Ferric Reducing Ability of Plasma, Advanced Oxidation Protein Products and Advanced Glycation End Products

AIM

To investigate the association between vitamin D3 level and oxidative stress biomarkers such as Heat Shock Protein 70 (HSP70), ferric reducing ability of plasma (FRAP), advanced oxidation protein products (AOPP) and advanced glycation end products (AGEs) in patients with Type 2 diabetes.

METHOD

In this cross-sectional study, 54 patients including 32 females and 22 males with a mean age of 54.92 ± 11.37 years with T2D attending the diabetes clinic from 2021 to 2022 were included. According to the average level of vitamin D in this population (14.91), they were divided into two groups with vitamin D ≤15 ng/mL and vitamin D >15 ng/mL. Multivariate regression analysis was conducted to evaluate the relationship between vitamin D and AOPP, HSP and FRAP parameters. The correlation between vitamin D and other variables was evaluated via the Pearson correlation test.

RESULT

Vitamin D level had a positive relation with FRAP (β = 0.32, p = 0.017) and HSP (β = 0.39, p = 0.003), but had a negative relation with AOPP (β = -0.30, p = 0.02). The level of 2hPP also had a negative relation with the level of vitamin D (β = -0.33, p = 0.03). There was not any relationship between the level of vitamin D and AGEs or other variables. After adjusting for multiple confounders for the multivariate regression model, HSP remained significant.

CONCLUSION

This research indicates the relationship between vitamin D levels and oxidative stress biomarkers in patients with Type 2 diabetes.

Combined effect of pantoprazole and mesenchymal stem cells on experimentally induced gastric ulcer: implication of oxidative stress, inflammation and apoptosis pathways

Gastric ulcer (GU) is one of the most common diseases of the upper gastrointestinal tract that affects millions of people worldwide. This study aimed to investigate the possible alleviating effect of a combined treatment of pantoprazole (PANTO) and adipose tissue-derived mesenchymal stem cells (ADSCs) in comparison with each treatment alone on the healing process of the experimentally induced GU in rats, and to uncover the involved pathways. Rats were divided into five groups: (1) Control, (2) GU, (3) PANTO, (4) ADSCs and (5) ADSCs + PANTO. Markers of oxidative stress, inflammation and apoptosis were assessed. The current data indicated that PANTO-, ADSCs- and ADSCs + PANTO-treated groups showed significant drop (p < 0.05) in serum advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEPs) along with significant elevation (p < 0.05) in serum TAC versus the untreated GU group. Moreover, the treated groups (PANTO, ADSCs and ADSCs + PANTO) displayed significant down-regulation (p < 0.05) in gastric nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase 9 (MMP-9) and caspase-3 along with significant up-regulation (p < 0.05) in vascular endothelial growth factor (VEGF) and peroxisome proliferator-activated receptor gamma (PPARγ) genes expression compared to the untreated GU group. Immunohistochemical examination of gastric tissue for transforming growth factor β1 (TGF-β1), epidermal growth factor (EGF) and proliferating cell nuclear antigen (PCNA) showed moderate to mild and weak immune reactions, respectively in the PANTO-, ADSCs- and ADSCs + PANTO-treated rat. Histopathological investigation of gastric tissue revealed moderate to slight histopathological alterations and almost normal histological features of the epithelial cells, gastric mucosal layer, muscularis mucosa and submucosa in PANTO-, ADSCs- and ADSCs + PANTO-treated rats, respectively. Conclusively, the co-treatment with ADSCs and PANTO evidenced sententious physiological protection against GU by suppressing oxidative stress, inhibiting inflammation and reducing apoptosis with consequent acceleration of gastric tissue healing process.

Severity of Mitral Valve Stenosis - Possible Relationships With Blood Oxidant Markers and Antioxidants

BACKGROUND

This study examined whether the severity of mitral valve stenosis (MVS) is associated with oxidative stress (OS) markers in the blood, and other hematological and clinicodemographic parameters.Methods and Results: This prospective study was conducted between March and May 2022. Seventy-five patients with newly diagnosed MVS (25 mild, 25 moderate, 25 severe) were included. Mild, moderate, and severe MVS was defined as MV area >2, 1.5-2, and <1.5 cm2, respectively. Various OS markers and laboratory parameters were determined in venous blood samples. For predictive analyses, 2 different analyses were performed to detect patients with severe MVS and those with moderate or severe (moderate/severe) MVS. Age (P=0.388) and sex (P=0.372) distribution were similar in the 3 groups. Multiple logistic regression analysis revealed that a high white blood cell (WBC) count (P=0.023) and high malondialdehyde (P=0.010), superoxide dismutase (SOD; P=0.008), and advanced oxidation protein products (AOPP; P=0.007) levels were independently associated with severe MVS. A low platelet count (P=0.030) and high malondialdehyde (P=0.018), SOD (P=0.008), and AOPP (P=0.001) levels were independently associated with having moderate/severe MVS. The best discriminatory factors for severe MVS were SOD (cut-off >315.5 ng/mL) and glutathione (cut-off >4.7 μmol/L).

CONCLUSIONS

MVS severity seems to be affected by oxidant markers (malondialdehyde and AOPP), antioxidant enzymes (SOD), and inflammation-related cells (WBC and platelets). Future studies are needed to examine these relationships in larger populations.

RNA sequencing analysis of early-stage atherosclerosis in vascular-on-a-chip and its application for comparing combustible cigarettes with heated tobacco products

Our previous study showed promising results in replicating early-stage atherosclerosis when vascular endothelial cells (VECs) were exposed to cigarette smoke (CS) extract via M0 macrophages. We used an organ-on-a-chip system as an alternative to animal testing to model atherosclerosis, which is a complex disease involving endothelial and immune cell communications. By incorporating macrophages into the vascular-on-a-chip system, we aimed to mimic the indirect effects of inhalable substances, such as CS, on VECs. In the current study, we further examined the suitability of our in vitro system for mimicking early-stage atherosclerosis by transcriptomic analyses of VECs exposed to CS directly or indirectly via macrophages. We also incorporated M1 macrophages to replicate a preexisting inflammatory state. We found a greater number of differentially expressed genes (DEGs) in direct exposure methods than indirect exposure methods. However, a pathway analysis showed that the direct exposure of CS to VECs primarily caused cell death-related pathway alterations, and the "Atherosclerosis Signaling" pathway was predicted to be negatively regulated. Indirect exposure via M0 macrophages similarly showed that the identified DEGs were related to cell death, while the "Atherosclerosis Signaling" pathway was predicted to be activated. In contrast, cell death-related pathway alterations were not observed by indirect exposure of CS to VECs via M1 macrophages, but the pathway perturbations were similar to a pro-inflammatory positive control. In addition, the "Atherosclerosis Signaling" pathway was predicted to be activated in VECs that were indirectly exposed to CS via M1 macrophages. These results suggest that M0 or M1 macrophages contribute to atherogenic transcriptomic changes in VECs, although they affect cell death-related pathways differently. We also used indirect exposure methods to compare the effects of CS and heated tobacco product (HTP) aerosol. Notably, gene expression changes related to atherosclerosis were less pronounced in HTP aerosol-exposed VECs than CS. Our study highlights the utility of the vascular-on-a-chip system with indirect exposure of CS extract via macrophages for replicating atherogenesis and suggests a reduced risk potential of the HTP. This research contributes to advancing alternatives to animal testing for toxicological and disease modeling studies.

Analysis of redox status and HDL subclasses in patients with lymphoma and the associations with FDG-PET/CT findings

Newer research points to alterations in the plasma redox status and the HDL subclass distributions in cancer. We aimed to assess the redox status and the HDL subclass distributions, lipids, and inflammatory markers in lymphoma patients in order to determine whether they were correlated with changes in FDG-PET/CT scans. At the beginning of this study, redox status, HDL subclasses, lipids, and inflammation biomarkers were determined in 58 patients with lymphoma (Hodgkin lymphoma, n=11 and non-Hodgkin lymphoma, n=47), and these same measurements were reassessed during their ensuing treatment (in 25 patients). Initially, the total oxidation status (TOS), the prooxidant-antioxidant balance (PAB), the OS index (OSI), the total protein sulfhydryl groups (SH-groups), and the advanced oxidation protein products (AOPP) were significantly higher in lymphoma patients as compared to healthy subjects, but the total antioxidant status (TAS) was significantly reduced. The PAB had a strong correlation with the CRP and interleukin-6 (rho=0.726, p<0.001; rho=0.386, p=0.003). The correlations between these parameters and the maximum standardized uptake values (SUVmax) were: PAB, rho=0.335 and p=0.010; SH-groups, rho=0.265 and p=0.044; CRP, rho=0.391 and p=0.002; HDL3b, rho=0.283 and p=0.031; HDL2b, rho= -0.294 and p=0.025; and HDL size, rho= -0.295 and p=0.024. The reductions in SUVmax between two follow-up points were associated with increases in the OSI, TOS, and SH-groups, as well as a reduction in the PAB and TAS. In conclusion, the redox parameters in patients with lymphoma were consistent with FDG-PET/CT findings. Targeting the redox status parameters and the HDL subclasses could be potential strategies in the molecular fight against lymphoma.

L-Carnitine supplementation reduces biomarkers of inflammatory and oxidative stress in patients with coronary artery disease: a randomised controlled trial

OBJECTIVE

l-Carnitine has been suggested as a potential nutrient that alleviates the oxidative and inflammatory damages of coronary artery disease (CAD), but the results of the previous studies of the importance of this supplementation remains unclear. This study attempts to evaluate the effects of l-carnitine (LC) supplementation on oxidative stress and inflammatory biomarkers in patients with CAD.

METHODS

A double-blind, randomised, placebo-trial was conducted on 75 CAD subjects. Patients were randomly assigned to receive LC (1000 mg/day) or placebo capsules over 3 months. Sera high-sensitivity C-reactive protein (hs-CRP), myeloperoxidase (MPO), nitrotyrosine (NT) and total antioxidant capacity (TAC) were assayed.

RESULTS

A significant increase in serum TAC and a significant decrease in MPO, NT, and hs-CRP levels were detected following 12 weeks of LC supplementation, compared to the placebo.

CONCLUSIONS

These results suggest that LC supplementation may exert beneficial effect on cardiovascular health through attenuate oxidative and inflammatory markers in CAD patients.

Relationship between red blood cell aggregation and dextran molecular mass

The aim of this study was to investigate the aggregation of red blood cells (RBCs) suspended in dextran solution at various levels of molecular mass. Dextran solutions at molecular mass 40, 70, 100 and 500 kDa at concentration from 2 to 5 g/dL were used to suspend the RBCs. The radius and velocity of sedimenting RBC aggregates were investigated using image analysis. The radius and sedimentation velocity of aggregates increased initially, then decreased after achieving maxima. The maximal velocity of RBC aggregates showed a bell-shaped dependence on dextran molecular mass and concentration, whereas maximal radius showed monotonic increase with both factors. Difference between aggregate and solution density was estimated using aggregate radius and sedimentation velocity and dextran solution viscosity, and was consistent across most molecular mass and concentration levels. This allowed to calculate the porosity of aggregates and to show that it monotonically decreased with the increase in the solution density, caused by the increase in the dextran concentration. The results provide insight into the RBC aggregation process in solutions of proteins of different size, reflecting various pathological conditions. The currently reported data can be potentially applied to specific pathophysiological conditions giving an interpretation that is not yet fully discussed in the literature.

Predictive value of oxidative stress biomarkers in drug-free patients with bipolar disorder

OBJECTIVE

Oxidative stress is one of the primary etiological mechanisms of bipolar disorder (BD).

METHODS

The present study was conducted over a period of 24 months on Tunisian on 34 drug‑free male patients with BD (mean age: 34.5 years) and 101 age and gender matched controls (mean age: 34.20 years) were enrolled in the study.

RESULTS

Plasma reduced glutathione (GSH) and total thiols levels were significantly decreased in patients compared to controls (respectively p < .001; p = .009). In addition, malondialdehyde (MDA), advanced oxidation protein products (AOPP), protein carbonyls (PC) and homocysteine (Hcys) concentrations and glutathione peroxidase (GSH-Px) activity were significantly increased in patients compared to controls (p = .002; p < .001; p = .001; p < .001 and p = .016, respectively). The binary logistic regression analysis revealed that MDA, AOPP and Hcys could be considered as independent risk factors for BD. When using CombiROC analysis, a remarkable increase in the area under the curve (AUC) with higher sensitivity (Se) and specificity (Sp) for MDA, AOPP, PC, GSH-Px and Hcys combined markers was observed.

CONCLUSIONS

Overall, the identification of the predictive value of these five selected biomarkers related to oxidative stress in drug free patients should lead to a better identification of the etiological mechanism of BD.

Study of Albumin Oxidation in COVID-19 Pneumonia Patients: Possible Mechanisms and Consequences

Oxidative stress induced by neutrophils and hypoxia in COVID-19 pneumonia leads to albumin modification. This may result in elevated levels of advanced oxidation protein products (AOPPs) and advanced lipoxidation end-products (ALEs) that trigger oxidative bursts of neutrophils and thus participate in cytokine storms, accelerating endothelial lung cell injury, leading to respiratory distress. In this study, sixty-six hospitalized COVID-19 patients with respiratory symptoms were studied. AOPPs-HSA was produced in vitro by treating human serum albumin (HSA) with chloramine T. The interaction of malondialdehyde with HSA was studied using time-resolved fluorescence spectroscopy. The findings revealed a significantly elevated level of AOPPs in COVID-19 pneumonia patients on admission to the hospital and one week later as long as they were in the acute phase of infection when compared with values recorded for the same patients 6- and 12-months post-infection. Significant negative correlations of albumin and positive correlations of AOPPs with, e.g., procalcitonin, D-dimers, lactate dehydrogenase, aspartate transaminase, and radiological scores of computed tomography (HRCT), were observed. The AOPPs/albumin ratio was found to be strongly correlated with D-dimers. We suggest that oxidized albumin could be involved in COVID-19 pathophysiology. Some possible clinical consequences of the modification of albumin are also discussed.

Effect of Spiritual Care Based on the Sound Heart Model on Spiritual Experiences of Hemodialysis Patients

Hemodialysis patients require spiritual care due to their spiritual distress. This study aimed to investigate the effect of spiritual care on spiritual experiences of hemodialysis patients. This randomized controlled trial was conducted in 2017 at hemodialysis departments of Baqiyatallah and Cham ran hospitals in Tehran. The volunteer patients were selected by available sampling according to the inclusion criteria. Participants were randomly assigned to intervention and control groups. Interventions were performed in the educational-supportive nursing system according to the patients' self-care ability. Eight individual counseling sessions, 15-45 min, face-to-face, during dialysis, once a week were implemented for intervention group. Developing the relationship with God, self, people and nature were the main goals of care. Daily spiritual experience questionnaire was completed by patients before and three months after the intervention. There was no significant difference in the spiritual experience score of the intervention (75.20 ± 9.14) and control group (76.63 ± 10.03), before the intervention (P = 0.523). There was a statistically significant difference between the intervention (82.93 ± 5.69) and the control group score (77.24 ± 12.09) three months after the intervention (P < 0.0001). Due to the need for holistic and community-oriented care and the positive effect of this study, the use of the Sound Heart Model is recommended for Muslim patients.

Targeting Scavenger Receptors in Inflammatory Disorders and Oxidative Stress

Oxidative stress and inflammation cannot be considered as diseases themselves; however, they are major risk factors for the development and progression of the pathogenesis underlying many illnesses, such as cancer, neurological disorders (including Alzheimer’s disease and Parkinson’s disease), autoimmune and metabolic disorders, etc. According to the results obtained from extensive studies, oxidative stress–induced biomolecules, such as advanced oxidation protein products, advanced glycation end products, and advanced lipoxidation end products, are critical for an accelerated level of inflammation and oxidative stress–induced cellular damage, as reflected in their strong affinity to a wide range of scavenger receptors. Based on the limitations of antioxidative and anti-inflammatory molecules in practical applications, targeting such interactions between harmful molecules and their cellular receptors/signaling with advances in gene engineering technology, such as CRISPR or TALEN, may prove to be a safe and effective alternative. In this review, we summarize the findings of recent studies focused on the deletion of scavenger receptors under oxidative stress as a development in the therapeutic approaches against the diseases linked to inflammation and the contribution of advanced glycation end products (AGEs), advanced lipid peroxidation products (ALEs), and advanced oxidation protein products (AOPPs).

p53 SUMOylation Mediates AOPP-Induced Endothelial Senescence and Apoptosis Evasion

The aging of endothelial cells plays a critical role in the development of age-related vascular disease. We established a model of endothelial premature senescence by application of Advanced oxidation protein products (AOPPs) modified bovine serum albumin (AOPP-BSA) in human umbilical vein endothelial cells (HUVECs). This cellular senescence was accompanied with endothelial barrier dysfunction and angiogenesis impairment. It was further revealed that these senescent HUVECs underwent apoptosis evasion and the receptor for advanced glycation endproducts (RAGE) played a role in these processes. The AOPP-induced senescence was regulated by the state of autophagy in HUVECs. We further proved that AOPP-BSA attenuated the autophagy of HUVECs, led to p53 SUMOylation at K386, resulting in endothelial senescence. We also established the animal model of vascular senescence by using ApoE^−/− mice fed with high-fat diet plus daily injection of AOPP-BSA to verify the role of p53 SUMOylation in vascular senescence. Combined with intraperitoneal injection of rapamycin, the effect of autophagy on AOPP-induced p53 SUMOylation was also confirmed in vivo. Our data indicates that p53 SUMOylation at K386 plays an important role in AOPP-induced endothelial senescence and apoptosis evasion, suggesting that p53 K386 SUMOylation may serve as a potential therapeutic target in protecting against vascular senescence.

Level of advanced oxidation protein products is associated with subclinical atherosclerosis

Background

Oxidative stress is an important factor in the pathomechanism of atherosclerosis. Advanced oxidation protein products (AOPPs) are considered markers of oxidative stress. Thickening of the carotid intima-media layers indicates subclinical atherosclerosis and can be detected by carotid ultrasound.

Objective

Our aim was to examine the association between carotid intima-media thickness (CIMT) and the level of AOPPs.

Methods

Carotid duplex scans and measurements of AOPPs were performed on 476 participants of a cardiovascular population study. The presence of conventional cardiovascular risk factors was investigated with a questionnaire, physical examination, and laboratory tests.

Results

There was a positive correlation between maximum CIMT and the level of AOPPs only in the male population (r = 0.219, p = 0.033). Multivariate analysis has revealed that the association between AOPPs and mean or maximum CIMT was independent of cardiovascular risk factors (OR = 1.458, p = 0.004, and OR = 2.038, p < 0.001).

Conclusions

Among males, the elevated level of AOPPs as a marker of oxidative stress may signal the existence of early atherosclerotic alterations.

A potential role of autophagy-mediated vascular senescence in the pathophysiology of HFpEF

Heart failure with preserved ejection fraction (HFpEF) is one of the most complex and most prevalent cardiometabolic diseases in aging population. Age, obesity, diabetes, and hypertension are the main comorbidities of HFpEF. Microvascular dysfunction and vascular remodeling play a major role in its development. Among the many mechanisms involved in this process, vascular stiffening has been described as one the most prevalent during HFpEF, leading to ventricular-vascular uncoupling and mismatches in aged HFpEF patients. Aged blood vessels display an increased number of senescent endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). This is consistent with the fact that EC and cardiomyocyte cell senescence has been reported during HFpEF. Autophagy plays a major role in VSMCs physiology, regulating phenotypic switch between contractile and synthetic phenotypes. It has also been described that autophagy can regulate arterial stiffening and EC and VSMC senescence. Many studies now support the notion that targeting autophagy would help with the treatment of many cardiovascular and metabolic diseases. In this review, we discuss the mechanisms involved in autophagy-mediated vascular senescence and whether this could be a driver in the development and progression of HFpEF.

Implications of advanced oxidation protein products and vitamin E in atherosclerosis progression

Introduction

Advanced oxidation protein products (AOPP) are considered as markers of oxidative stress and inflammation, and highly predictive of atherosclerosis. Vitamin E (Vit-E) is a powerful antioxidant, but no consensus on its effectiveness at the level of AOPP or the process of atherosclerosis has been made. Hence this was the aim of the present study.

Material and methods

A longitudinal study was conducted on 205 patients with chronic kidney disease (CKD) and 40 controls. The correlations between AOPP and glomerular filtration rate (GFR) and different biological markers were analyzed. Supra-aortic trunk echo-Doppler was conducted to assess the correlation of AOPP with intima-media thickness. The effects of Vit-E treatment on AOPP levels and atherosclerosis progression were also investigated.

Results

AOPP levels increased in parallel to the alteration of renal functions in CKD patients, compared to the control group (p < 0.05). The mean value of AOPP increased concomitantly with the intima-media thickness (p < 0.05). Furthermore, AOPP mean value was higher in patients with atherosclerotic plaques (p < 0.05) compared to those without plaques. Vit-E treatment stabilized the levels of AOPP but had no effect on the atherosclerotic progression.

Conclusions

AOPP were proved to be effective markers of oxidative stress and their high levels help to predict the progression of atherosclerosis. As a powerful antioxidant, Vit-E stabilized the AOPP levels.

Oxidation of lysozyme induced by peroxyl radicals involves amino acid modifications, loss of activity, and formation of specific crosslinks

The present work examined the oxidation and crosslinking of the anti-bacterial enzyme lysozyme (Lyso), which is present in multiple biological fluids, and released from the cytoplasmic granules of macrophages and neutrophils at sites of infection and inflammation. It is therefore widely exposed to oxidants including peroxyl radicals (ROO•). We hypothesized that exposure to ROO• would generate specific modifications and inter- and intra-protein crosslinks via radical-radical reactions. Lyso was incubated with AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride) as a ROO• source. Enzymatic activity was assessed, while oxidative modifications were detected and quantified using electrophoresis and liquid chromatography (UPLC) with fluorescence or mass detection (MS). Computational models of AAPH-Lyso interactions were developed. Exposure of Lyso to AAPH (10 and 100 mM for 3 h, and 20 mM for 1 h), at 37 °C, decreased enzymatic activity. 20 mM AAPH showed the highest efficiency of Lyso inactivation (1.78 mol of Lyso inactivated per ROO•). Conversion of Met to its sulfoxide, and to a lesser extent, Tyr oxidation to 3,4-dihydroxyphenylalanine and diTyr, were detected by UPLC-MS. Extensive transformation of Trp, involving short chain reactions, to kynurenine, oxindole, hydroxytryptophan, hydroperoxides or di-alcohols, and N-formyl-kynurenine was detected, with Trp62, Trp63 and Trp108 the most affected residues. Interactions of AAPH inside the negatively-charged catalytic pocket of Lyso, with Trp108, Asp52, and Glu35, suggest that Trp108 oxidation mediates, at least partly, Lyso inactivation. Crosslinks between Tyr20-Tyr23 (intra-molecular), and Trp62-Tyr23 (inter-molecular), were detected with both proximity (Tyr20-Tyr23), and chain flexibility (Trp62) appearing to favor the formation of covalent crosslinks.

Is the Oxidative Stress in Obstructive Sleep Apnea Associated With Cardiovascular Complications?-Systematic Review

Obstructive sleep apnea (OSA) is a prevalent, underdiagnosed disease and is considered an independent risk factor for cardiovascular disease. The exact mechanism of cardiovascular complications (CVC) development as a complication of OSA is not entirely understood. Oxidative stress is suspected to be the essential factor in initiating various comorbidities in OSA. Biomarkers of nonenzymatic lipid and protein peroxidation, DNA repair and antioxidant capabilities measured in serum, plasma and urine are frequently used to assess the presence of oxidative stress. We conducted a systematic review and quality assessment of available observational analytic studies to determine whether there is an association between oxidative stress and OSA in patients with prevalent CV disease compared to (a) patients with prevalent CV disease but no OSA, (b) patients with prevalent CV disease and less severe OSA and (c) patients with OSA and no overt CV disease. This systematic review demonstrated that, while oxidative stress is associated with OSA, there was no clear difference in the severity of oxidative stress between OSA patients with or without cardiovascular complications.

Predictive value of oxidative stress biomarkers in drug‑free patients with schizophrenia and schizo-affective disorder

Several studies have suggested that oxidative stress may represent one of the primary etiological mechanisms of schizophrenia (SZ) and schizoaffective disorder (SAD) which can be targeted by therapeutic intervention. The present study was conducted over a period of 24 months, between June 2016 and June 2018. All enrolled subjects were Tunisian, forty five drug‑free male patients with SZ (mean age: 37.6 years), twenty one drug‑free male patients with SAD (mean age: 28.8 years) and hundred and one age and gender matched controls (mean age: 34.2 years) were enrolled in the study. Plasma reduced glutathione (GSH) and Total thiols levels were significantly decreased in patients compared to controls (respectively p<0.001; p=0.050). In addition, malondialdehyde (MDA), advanced oxidation protein products (AOPP) and protein carbonyls (PC) concentrations and glutathione peroxidase (GSH-Px) activity were significantly increased in patients compared to controls (p<0.001; p<0.001; p<0.001 and p=0.003 respectively). The binary logistic regression analysis revealed that MDA, AOPP, PC and GSH-Px could be considered as independent risk factors for SZ and SAD. When using ROC analysis, a remarkable increase in the area under the curve (AUC) with higher sensitivity (Se) and specificity (Sp) for MDA, AOPP, PC and GSH-Px combined markers was observed. The present study indicated that the identification of the predictive value of this four-selected biomarkers related to oxidative stress in drug free patients should lead to a better identification of the etiological mechanism of SZ or SAD.

Metformin protects against diabetes-induced heart injury and dunning prostate cancer model

In this study, both diabetes and Dunning prostate cancer were induced for the first time in Copenhagen rats in vivo. Thus, the effects of metformin against heart tissue damage of these rats were investigated by biochemical methods. Dunning prostate cancer was induced in Copenhagen rats using high metastatic MAT-LyLu cells. The rats were divided as follows: Control group: only injected with 0.9% NaCl for 14 days; Diabetic group: only injected single dose of streptozotocin (STZ) (65 mg/kg); Cancer group: subcutaneously (s.c) inoculated with 2 x 10⁴ MAT-LyLu cells only; Diabetic + cancer (DC) group: inoculated with 2 x 10⁴ MAT-LyLu cells and STZ injection, Cancer + metformin (CM) group: injected with metformin for 14 days after Mat-LyLu cells application; Diabetic + cancer + metformin (DCM) group: metformin administered for 14 days together with STZ and Mat-LyLu cells. At the end of the experimental period, heart tissues were taken. Reduced glutathione and total antioxidant status levels in heart tissues were decreased, whereas lipid peroxidation, advanced oxidized protein products, nitric oxide, homocysteine, and reactive oxygen species levels, total oxidant status and catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and xanthine oxidase activities increased in the diabetic, cancer and DC groups. Treatment with metformin reversed these effects. In conclusion, the present study shows that metformin has a protective effect against heart tissue damage in STZ-induced diabetic rats with Dunning prostate cancer.

Ox-LDL Causes Endothelial Cell Injury Through ASK1/NLRP3-Mediated Inflammasome Activation via Endoplasmic Reticulum Stress

Objective

This study was to investigate the mechanism of inflammatory pathology modification induced by ox-LDL in endothelial cells.

Methodology

In this study, we firstly investigated the efflux of cholesterol of endothelial cells under the treatment of ox-LDL, and cell proliferation, ROS production, cell apoptosis was measured. Further, proteins of ASK1, NLRP3 inflammasomes and endoplasmic reticulum stress response were detected. Afterwards, ASK1 inhibitor (GS-4997) or endoplasmic reticulum stress (ERS) inhibitor (4-PBA) was used to measure the performance of endothelial cells.

Results

In this study, endothelial cells were treated with ox-LDLs alone or in combination with a GS-4997 or 4-PBA. Results showed that ox-LDLs attenuated the efflux of cholesterol from endothelial cells in a dose-dependent manner. Ox-LDLs inhibited the proliferation of endothelial cells, and induced their apoptosis and production of reactive oxygen species (ROS). Additionally, ox-LDLs upregulated the levels of phosphorylated ASK1, ERS-related proteins (chop, p-PERK, GRP78, and p-IRE-1), and inflammation-associated proteins (NLRP3, IL-1β, and caspase 1) in endothelial cells. Moreover, we proved that GS-4997 could partly reverse ox-LDL-mediated cell proliferation, apoptosis, ROS production, and inflammation in endothelial cells, and increase cholesterol efflux. We also found that 4-PBA could attenuate the effects of ox-LDLs on endothelial cell cholesterol efflux, proliferation, apoptosis, ROS production, and inflammation.

Conclusion

Our results suggest that cholesterol efflux from endothelial cells is reduced by ox-LDLs, and these reductions in cholesterol efflux are accompanied by increased NLRP3 inflammasome signaling, ASK1 and higher levels of endoplasmic reticulum stress. Our results suggest this axis as potential targets for treating atherosclerosis.

Oxidative Modifications in Advanced Atherosclerotic Plaques: A Focus on In Situ Protein Sulfhydryl Group Oxidation

Although oxidative stress has been long associated with the genesis and progression of the atherosclerotic plaque, scanty data on its in situ effects on protein sulfhydryl group modifications are available. Within the arterial wall, protein sulfhydryls and low-molecular-weight (LMW) thiols are involved in the cell regulation of both Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) levels and are a target for several posttranslational oxidative modifications that take place inside the atherosclerotic plaque, probably contributing to both atherogenesis and atherosclerotic plaque progression towards complicated lesions. Advanced carotid plaques are characterized by very high intraplaque GSH levels, due to cell lysis during apoptotic and/or necrotic events, probably responsible for the altered equilibrium among protein sulfhydryls and LMW thiols. Some lines of evidence show that the prooxidant environment present in atherosclerotic tissue could modify filtered proteins also by protein-SH group oxidation, and demonstrate that particularly albumin, once filtered, represents a harmful source of homocysteine and cysteinylglycine inside the plaque. The oxidative modification of protein sulfhydryls, with particular emphasis to protein thiolation by LMW thiols and its association with atherosclerosis, is the main topic of this review.

Translational incorporation of modified phenylalanines and tyrosines during cell-free protein synthesis

Inherent promiscuity of bacterial translation is demonstrated by mass spectrometric quantification of the translational incorporation of ring-substituted phenylalanines and tyrosines bearing fluoro-, hydroxyl-, methyl-, chloro- and nitro-groups in an E. coli-derived cell-free system. Competitive studies using the cell-free system show that the aminoacyl-tRNA synthetases (aaRS) have at least two orders of magnitude higher specificity for the native substrate over these structural analogues, which correlates with studies on the purified synthetase.

E. coli wild-type translational machinery utilizes a range of nonproteinogenic amino acids for protein synthesis with incorporation levels greater than 95%.

Association of Higher Advanced Oxidation Protein Products (AOPPs) Levels in Patients with Diabetic and Hypertensive Nephropathy

Background and Objectives: Diabetes mellitus (DM) and hypertension (HT) are characterized by cell damage caused by inflammatory and metabolic mechanisms induced by alteration in reduction-oxidative status. Serum advanced oxidation protein products (AOPP) are new markers of protein damage induced by oxidative stress. We evaluated serum levels of AOPP in a cohort of patients with DM and HT, with or without renal complications, compared with a control healthy population. Materials and Methods: The study group comprised of 62 patients with type 2 DM and 56 with HT. The 62 patients affected by DM were further distinguished in 24 subjects without renal impairment, 18 with diabetic nephropathy (DN), 20 with chronic kidney disease (CKD) stage 2–3 secondary to DN. The subgroup of 56 patients with primary HT comprised 26 subjects without renal complications and 30 with CKD (stage 2–3) secondary to HT. Thirty healthy controls, matched for age and sex, were recruited among blood donors. Results: Increased AOPP levels were found in DM patients compared with healthy subjects, although not significantly. This index was higher and more significant in patients with DN and CKD secondary to DN than in DM patients without nephropathy (p < 0.05) or controls (p < 0.0001). Patients with HT and with kidney impairment secondary to HT also had significantly higher AOPP serum levels than controls (p < 0.01 and p < 0.0001, respectively). There were no significant differences in mean AOPP levels among DM and HT patients. Conclusion: Our study showed that oxidative stress was higher in diabetic or hypertensive subjects than in healthy controls and, in particular, it appeared to be more severe in patients with renal complications. We suggest that the assessment of AOPP in diabetic and hypertensive patients may be important to predict the onset of renal failure and to open a new perspective on the adoption of antioxidant molecules to prevent CKD in those settings.

Analysis of levels of oxidative stress markers depending on the left ventricular ejection fraction in patients with chronic heart failure

Aim.To study and analyze the levels of oxidative stress (OS) markers (malondialdehyde (MDA), superoxide dismutase (SOD), advanced oxidation protein products (AOPPs)) depending on the left ventricular ejection fraction (LVEF) and functional class (FC) in patients with chronic heart failure (CHF).

Material and methods.We examined 60 somatically healthy individuals and 345 patients with CHF, which were divided into three main groups depending on the LVEF and subgroups depending on FC. The levels of OS markers were determined in blood serum — MDA, SOD and AOPPs.

Results.In the group of patients with preserved LVEF and FC II-IV CHF, levels of MDA and AOPPs were statistically significantly higher, and the SOD level was lower compared to the control group. In the group of patients with moderately reduced and reduced LVEF, the levels of MDA and AOPPs were statistically significantly higher, and SOD activity was lower compared with the control group and the group of patients with CHF and preserved LVEF. In patients with CHF with higher FC, there was a statistically significant increase of MDA and AOPPs levels and decrease of SOD activity. The most pronounced changes in the levels of above-mentioned markers were recorded in patients with reduced LVEF. According to the correlation analysis a direct relationship between the levels of markers of the OS and clinical manifestations of the disease was found.

Conclusion.Changes in levels of MDA, SOD and AOPPs in patients with CHF were detected already in the early stages of the disease compared with the control group. In patients with higher FC CHF and preserved, moderately reduced and reduced LVEF, a statistically significant increase in the levels of MDA and AOPPs and a decrease of SOD activity were observed. The most pronounced changes in the levels of the markers were indicated in patients with reduced LVEF.

The Consumption of Beef Burgers Prepared with Wine Grape Pomace Flour Improves Fasting Glucose, Plasma Antioxidant Levels, and Oxidative Damage Markers in Humans: A Controlled Trial

Wine grape pomace flour (WGPF) is a fruit byproduct that is high in fiber and antioxidants. We tested whether WGPF consumption could affect blood biochemical parameters, including oxidative stress biomarkers. In a three-month intervention study, 27 male volunteers, each with some components of metabolic syndrome, consumed a beef burger supplemented with 7% WGPF containing 3.5% of fiber and 1.2 mg gallic equivalents (GE)/g of polyphenols (WGPF-burger), daily, during the first month. The volunteers consumed no burgers in the second month, and one control-burger daily in the third month. At baseline and after these periods, we evaluated the metabolic syndrome components, plasma antioxidant status (i.e., 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH), vitamin E, vitamin C), and oxidative damage markers (i.e., advanced oxidation protein products (AOPPs), oxidized low-density lipoproteins (oxLDLs), malondialdehyde (MDA)). The WGPF-burger intake significantly reduced glycemia and homeostatic model assessment-based measurement of insulin resistance. Vitamin C increased and decreased during the consumption of the WGPF-burger and control-burger, respectively. The WGPF-burger intake significantly decreased AOPP and oxLDL levels. Vitamin E and MDA levels showed no significant changes. In conclusion, the consumption of beef burgers prepared with WGPF improved fasting glucose and insulin resistance, plasma antioxidant levels, and oxidative damage markers. Therefore, this functional ingredient has potential as a dietary supplement to manage chronic disease risk in humans.

[Association of plasma level of advanced oxidation protein products with Framingham risk score in type 2 diabetic patients without vascular diseases]

OBJECTIVE

To explore the association of plasma level of advanced oxidation protein products (AOPPs) with Framingham risk score in type 2 diabetic patients without vascular diseases.

METHDOS

This cross-sectional study was conducted among type 2 diabetic patients without vascular diseases recruited from 3 affiliated hospitals of Southern Medical University between March, 2010 and May, 2011, with age- and gender-matched healthy individuals as the control group. The demographic data were collected from all the participants, and the biochemical indexes and plasma levels of AOPPs were examined. The risk of cardiovascular disease in 10 years was assessed for all the participants based on their Framingham risk scores.

RESULTS

A total of 112 diabetic patients and 49 healthy subjects were enrolled in this study. The diabetic patients had significantly higher body mass index (BMI), blood glucose, triglyceride, low-density lipoprotein (LDL), plasma AOPPs and Framingham risk score but lower high-density lipoprotein level than the control subjects. Spearman correlation analysis showed that plasma level of AOPPs was positively correlated with the Framingham risk score (r=-0.44, P<0.001), and further multiple linear regression analysis suggested that plasma AOPPs level was independently correlated with the Framingham risk score (β0.305, P<0.001).

CONCLUSION

Type 2 diabetic patients without vascular diseases have significantly higher plasma levels of AOPPs and are at a greater risk of cardiovascular events in 10 years than healthy individuals. Plasma AOPPs are positively correlated with the Framingham risk score, suggesting the value of plasma AOPPs level in predicting the risk of cardiovascular events in these patients.

Role of AMPK in atherosclerosis via autophagy regulation

Atherosclerosis is characterized by the accumulation of lipids and deposition of fibrous elements in the vascular wall, which is the primary cause of cardiovascular diseases. Adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor of energy metabolism that regulates multiple physiological processes, including lipid and glucose metabolism and the normalization of energy imbalances. Overwhelming evidence indicates that AMPK activation markedly attenuates atherosclerosis development. Autophagy inhibits cell apoptosis and inflammation and promotes cholesterol efflux and efferocytosis. Physiological autophagy is essential for maintaining normal cardiovascular function. Increasing evidence demonstrates that autophagy occurs in developing atherosclerotic plaques. Emerging evidence indicates that AMPK regulates autophagy via a downstream signaling pathway. The complex relationship between AMPK and autophagy has attracted the attention of many researchers because of this close relationship to atherosclerosis development. This review demonstrates the role of AMPK and autophagy in atherosclerosis. An improved understanding of this interrelationship will create novel preventive and therapeutic strategies for atherosclerosis.