Role of Iron-Related Oxidative Stress and Mitochondrial Dysfunction in Cardiovascular Diseases

Impact of serum iron levels on in-hospital mortality and clinical outcomes in patients with ST segment elevation myocardial infarction undergoing emergency percutaneous coronary intervention: a retrospective analysis

BACKGROUND

Despite advances in percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI), in-hospital mortality remains a concern, highlighting the need for the identification of additional risk factors such as serum iron levels.

OBJECTIVE

This study aims to assess the relationship between serum iron levels and in-hospital mortality among patients with STEMI undergoing emergency PCI.

METHODS

A total of 685 patients diagnosed with STEMI, treated with emergency PCI between January 2020 and June 2023, were included in this retrospective observational study. Participants were categorized based on serum iron levels into a low serum iron group (Fe <7.8 μmol/L) and a control group (Fe ≥7.8 μmol/L). Clinical and biochemical variables were compared between the groups. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for in-hospital mortality.

RESULTS

The low serum iron group demonstrated significantly higher in-hospital mortality rates (9.3 vs. 1.0%, P  < 0.05) compared with the control group. Multivariate logistic regression revealed that a left ventricular ejection fraction less than 40% upon admission [odds ratio (OR), 8.01; 95% confidence interval (CI), 1.230-52.173; P  = 0.029], the occurrence of no-reflow during PCI (OR, 7.13; 95% CI, 1.311-38.784; P  = 0.023), and serum iron levels below 7.8 μmol/L (OR, 11.32; 95% CI, 2.345-54.640; P  = 0.003) were independent risk factors for in-hospital mortality.

CONCLUSION

Low serum iron levels are associated with increased in-hospital mortality in patients with STEMI undergoing emergency PCI. Serum iron levels may serve as an independent prognostic marker and could inform risk stratification and therapeutic targeting in this patient population.

Cardiotoxicity of Iron and Zinc and Their Association with the Mitochondrial Unfolded Protein Response in Humans

This study was designed to examine the association between myocardial concentrations of the trace elements Cu, Fe, Mn, Mo, and Zn and the expression of mitochondrial unfolded protein response (UPRmt) elements and the age of patients who received heart transplantation or a left-ventricular assist device (ageHTx/LVAD). Inductively coupled plasma mass spectrometry was used to determine the concentration of Cu, Fe, Mn, Mo, and Zn in the myocardium of control subjects and patients undergoing heart transplantation or left-ventricular assist device (LVAD) implantation. We used ELISA to quantify the expression of UPRmt proteins and 4-Hydroxynonenal (4-HNE), which served as a marker of oxidative-stress-induced lipid peroxidation. Concentrations of Cu, Mn, Mo, and Zn were similar in the control and heart failure (HF) myocardium, while Fe showed a significant decrease in the HF group compared to the control. A higher cumulative concentration of Fe and Zn in the myocardium was associated with reduced ageHTx/LVAD, which was not observed for other combinations of trace elements or their individual effects. The trace elements Cu, Mn, and Zn showed positive correlations with several UPRmt proteins, while Fe had a negative correlation with UPRmt effector protease YME1L. None of the trace elements correlated with 4-HNE in the myocardium. The concentrations of the trace elements Mn and Zn were significantly higher in the myocardium of patients with dilated cardiomyopathy than in patients with ischemic cardiomyopathy. A higher cumulative concentration of Fe and Zn in the myocardium was associated with a younger age at which patients received heart transplantation or LVAD, potentially suggesting an acceleration of HF. A positive correlation between myocardial Cu, Mn, and Zn and the expression of UPRmt proteins and a negative correlation between myocardial Fe and YME1L expression suggest that these trace elements exerted their actions on the human heart by interacting with the UPRmt. An altered generation of oxidative stress was not an underlying mechanism of the observed changes.

Red and processed meat intake and risk of cardiovascular disease: A two-sample Mendelian randomization study

BACKGROUND & AIMS

Previous observational studies have yielded inconsistent findings regarding associations between red/processed meat intake and the risk of cardiovascular disease (CVD). Some studies have suggested positive relationships, while others have demonstrated no significant associations. However, causal effects remain uncertain. This 2023 Mendelianrandomization (MR) study investigated the causal relationship between red and processed meat (porkmeat, mutton meat, beef meat)intake and CVD risk by analyzing summary data from the UK Biobank (exposure), CARDIoGRAMplusC4D (coronary artery disease [CAD]), MEGASTROKE (stroke), Nielsen et al. (atrial fibrillation [AF]), HERMES (heart failure [HF]), and FinnGen (cardiovascular outcomes) public databases.

METHODS

Genome-wide association studies (GWAS) of red meat (pork, beef, and mutton) and processed meat were sourced from the United Kingdom (UK) Biobank. GWAS data on CVD for this study were obtained from the Gene and FinnGen consortia. The primary method employed for the two-sample MR analysis was inverse variance weighting (IVW). Sensitivity analysis was performed to assess the reliability and consistency of the results.

RESULTS

Genetically predicted red and processed meat consumption did not demonstrate a causal association with any CVD outcomes when employing the IVW method. For processed meat intake, the odds ratios (ORs) (95% confidence intervals CIs) in large consortia were as follows: 0.88 (0.56-1.39) for CAD, 0.91 (0.65-1.27) for AF, 0.84 (0.58-1.21) for HF, and 1.00 (0.75-1.05) for stroke. In FinnGen, the ORs were as follows: 1.15 (0.83-1.59) for CAD, 1.25 (0.75-2.07) for AF, 1.09 (0.73-1.64) for HF, and 1.27 (0.85-1.91) for stroke. For beef intake, the ORs (95% CIs) in large consortia were as follows: 0.70 (0.28-1.73) for CAD, 0.85 (0.49-1.49) for AF, 0.80 (0.35-1.83) for HF, and 1.29 (0.85-1.95) for stroke. In FinnGen, the ORs were as follows: 2.01 (0.75-5.39) for CAD, 1.83 (0.60-5.56) for AF, 0.80 (0.30-2.13) for HF, and 1.30 (0.62-2.73) for stroke. For pork intake, the ORs (95% CIs) in large consortia were as follows: 1.25 (0.37-4.22) for CAD, 1.26 (0.73-2.15) for AF, 1.71 (0.86-3.39) for HF, and 1.15 (0.63-2.11) for stroke. In FinnGen, the ORs were as follows: 1.12 (0.43-2.88) for CAD, 0.39 (0.08-1.83) for AF, 0.62 (0.20-1.88) for HF, and 0.60 (0.21-1.65) for stroke. For mutton intake, the ORs (95% CIs) in large consortia were as follows: 0.84 (0.48-1.44) for CAD, 0.84 (0.56-1.26) for AF, 1.04 (0.65-1.67) for HF, and 1.06 (0.77-1.45) for stroke. In FinnGen, the ORs were as follows: 1.20 (0.65-2.21) for CAD, 0.92 (0.44-1.92) for AF, 0.74 (0.34-1.58) for HF, and 0.75 (0.45-1.24) for stroke. The results remained robust and consistent in both the meta-analysis and supplementary MR analysis.

CONCLUSIONS

This MR study demonstrated no significant causal relationships between red/processed meat intake and the risk of the four CVD outcomes examined. Further investigation is warranted to confirm these findings.

Heat stress suppresses MnSOD expression via p53-Sp1 interaction and induces oxidative stress damage in endothelial cells: Protective effects of MitoQ10 and Pifithrin-α

Aim

To investigate the mechanism of p53-mediated suppression of heat stress-induced oxidative stress damage by manganese superoxide dismutase (MnSOD) in endothelial cells (ECs).

Methods

Primary ECs isolated from mouse aortas were used to examine the effects of heat stress on vascular ECs viability and apoptosis. We measured MnSOD expression, reactive oxygen species (ROS) production, p53 expression, viability, and apoptosis of heat stress-induced ECs. We also tested the protective effects of MitoQ10, a mitochondrial-targeted antioxidant, and Pifithrin-α, a p53 inhibitor, in ECs from a mouse model of heat stroke.

Results

Heat stress increased cellular apoptosis, ROS production, and p53 expression, while reducing cellular viability and MnSOD expression in ECs. We also showed that the suppression of MnSOD expression by heat stress in ECs was mediated by interactions between p53 and Sp1. Furthermore, MitoQ10 and Pifithrin-α alleviated heat stress-induced oxidative stress and apoptosis in ECs.

Conclusion

Our results revealed that p53-mediated MnSOD downregulation is a key mechanism for heat stress-induced oxidative stress damage in ECs and indicated that MitoQ10 and Pifithrin-α could be potential therapeutic agents for heat stroke.

Iron derived from NCOA4-mediated ferritinophagy causes cellular senescence via the cGAS-STING pathway

Cellular senescence is a hallmark of aging and has been linked to age-related diseases. Age-related macular degeneration (AMD), the most common aging-related retinal disease, is prospectively associated with retinal pigment epithelial (RPE) senescence. However, the mechanism of RPE cell senescence remains unknown. In this study, tert-butyl hydroperoxide (TBH)-induced ARPE-19 cells and D-galactose-treated C57 mice were used to examine the cause of elevated iron in RPE cell senescence. Ferric ammonium citrate (FAC)-treated ARPE-19 cells and C57 mice were used to elucidated the mechanism of iron overload-induced RPE cell senescence. Molecular biology techniques for the assessment of iron metabolism, cellular senescence, autophagy, and mitochondrial function in vivo and in vitro. We found that iron level was increased during the senescence process. Ferritin, a major iron storage protein, is negatively correlated with intracellular iron levels and cell senescence. NCOA4, a cargo receptor for ferritinophagy, mediates degradation of ferritin and contributes to iron accumulation. Besides, we found that iron overload leads to mitochondrial dysfunction. As a result, mitochondrial DNA (mtDNA) is released from damaged mitochondria to cytoplasm. Cytoplasm mtDNA activates the cGAS-STING pathway and promotes inflammatory senescence-associated secretory phenotype (SASP) and cell senescence. Meanwhile, iron chelator Deferoxamine (DFO) significantly rescues RPE senescence and retinopathy induced by FAC or D-gal in mice. Taken together, these findings imply that iron derived from NCOA4-mediated ferritinophagy causes cellular senescence via the cGAS-STING pathway. Inhibiting iron accumulation may represent a promising therapeutic approach for age-related diseases such as AMD.

Therapeutic effect of trace elements on multiple myeloma and mechanisms of cancer process

In the human body, trace elements and other micronutrients play a vital role in growth, health and immune system function. The trace elements are Iron, Manganese, Copper, Iodine, Zinc, Cobalt, Fluoride, and Selenium. Estimating the serum levels of trace elements in hematologic malignancy patients can determine the severity of the tumor. Multiple myeloma (MM) is a hematopoietic malignancy and is characterized by plasma cell clonal expansion in bone marrow. Despite the advances in treatment methods, myeloma remains largely incurable. In addition to conventional medicine, treatment is moving toward less expensive noninvasive alternatives. One of the alternative treatments is the use of dietary supplements. In this review, we focused on the effect of three trace elements including iron, zinc and selenium on important mechanisms such as the immune system, oxidative and antioxidant factors and cell cycle. Using some trace minerals in combination with approved drugs can increase patients' recovery speed. Trace elements can be used as not only a preventive but also a therapeutic tool, especially in reducing inflammation in hematological cancers such as multiple myeloma. We hope that the prospect of the correct use of trace element supplements in the future could be promising for the treatment of diseases.

Cardiomyocyte Damage: Ferroptosis Relation to Ischemia-Reperfusion Injury and Future Treatment Options

About half a century ago, Eugene Braunwald, a father of modern cardiology, shared a revolutionary belief that "time is muscle", which predetermined never-ending effort to preserve the unaffected myocardium. In connection to that, researchers are constantly trying to better comprehend the ongoing changes of the ischemic myocardium. As the latest studies show, metabolic changes after acute myocardial infarction (AMI) are inconsistent and depend on many constituents, which leads to many limitations and lack of unification. Nevertheless, one of the promising novel mechanistic approaches related to iron metabolism now plays an invaluable role in the ischemic heart research field. The heart, because of its high levels of oxygen consumption, is one of the most susceptible organs to iron-induced damage. In the past few years, a relatively new form of programmed cell death, called ferroptosis, has been gaining much attention in the context of myocardial infarction. This review will try to summarize the main novel metabolic pathways and show the pivotal limitations of the affected myocardium metabolomics.

Effects of ginseng consumption on the biomarkers of oxidative stress: A systematic review and meta-analysis

Oxidative stress (OS) is a key factor involved in the initiation and development of chronic diseases. Despite its widespread acceptance as an antioxidant, the effects of ginseng on OS in human clinical trials have not been comprehensively analyzed. Therefore, this study aimed to synthesize the results of previous randomized clinical trials (RCTs) examining the impact of ginseng consumption on OS indicators. PubMed, Web of Science, Scopus, and Cochrane databases were searched for articles on the effects of ginseng consumption on oxidative stress markers up to March 20, 2023. Standardized mean difference (SMD) and 95% confidence intervals (CIs) were used to assess effect sizes. Twelve RCTs with 15 effect sizes revealed that the effects of ginseng lowered serum malondialdehyde (MDA) levels (SMD = 0.45, 95% CI: -0.87, -0.08; p = 0.03) and significantly increased the serum total antioxidant capacity (TAC) (SMD = 0.23, 95% CI: 0.01, 0.45; p = 0.04), oxidative dismutase (SOD) (SMD = 0.39, 95% CI: 0.21, 0.57; p < 0.0001), glutathione (GSH) (SMD = 0.36; 95% CI: 0.11, 0.61; p = 0.005), and glutathione reductase (GR) (SMD = 0.56; 95% CI: 0.31, 0.81; p < 0.0001) levels compared to the effects of placebo. However, the effects on serum glutathione peroxidase (GPx) and catalase (CAT) were not significant. Moreover, subgroup analysis based on intervention duration showed that ginseng consumption increased GPx (SMD = 0.91, 95% CI: 0.05, 1.78; p = 0.039) and CAT (SMD = 0.74, 95% CI: 0.27, 1.21; p = 0.002) levels after more than 4 weeks of intervention. According to the results of this meta-analysis, ginseng supplementation dramatically reduced MDA levels and increased TAC, SOD, GSH, and GR levels. Our results open up a new line of defense against oxidative stress-induced diseases.

The Role of Oxidative Stress and Cellular Senescence in the Pathogenesis of Metabolic Associated Fatty Liver Disease and Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents a worryingly increasing cause of malignancy-related mortality, while Metabolic Associated Fatty Liver Disease (MAFLD) is going to become its most common cause in the next decade. Understanding the complex underlying pathophysiology of MAFLD-related HCC can provide opportunities for successful targeted therapies. Of particular interest in this sequela of hepatopathology is cellular senescence, a complex process characterised by cellular cycle arrest initiated by a variety of endogenous and exogenous cell stressors. A key biological process in establishing and maintaining senescence is oxidative stress, which is present in multiple cellular compartments of steatotic hepatocytes. Oxidative stress-induced cellular senescence can change hepatocyte function and metabolism, and alter, in a paracrine manner, the hepatic microenvironment, enabling disease progression from simple steatosis to inflammation and fibrosis, as well as HCC. The duration of senescence and the cell types it affects can tilt the scale from a tumour-protective self-restricting phenotype to the creator of an oncogenic hepatic milieu. A deeper understanding of the mechanism of the disease can guide the selection of the most appropriate senotherapeutic agent, as well as the optimal timing and cell type targeting for effectively combating HCC.

Anti-Obesity Actions of Two Separated Aqueous Extracts From Arbutus (Arbutus unedo) and Hawthorn (Crataegus monogyna) Fruits Against High-Fat Diet in Rats via Potent Antioxidant Target

Arbutus unedo and Crataegus monogyna are widely distributed throughout the Mediterranean basin and commonly used in folk medicine against a wide range of diseases. Therefore, the present study has been designed to evaluate the anti-obesity potential of two aqueous extracts of the fruits of A. unedo (AUAE) and C. monogyna (CMAE). Male Wistar rats were supplied with a standard diet (SD), high-fat diet (HFD), HFD with the two separated extracts at the same dose (300 mg/kg, BW, p. o.), or HFD with atorvastatin-(ATOR) (2.1 mg/kg, BW, p. o.) for 12 weeks. Lipid profile and the liver and kidney linked-markers were assessed. Besides, obesity-related disorders' biomarkers were measured. AUAE, CMAE, and ATOR were observed to reduce significantly total body and organ weights following HFD-induced obese rat models. Likewise, epididymal and abdominal adipose tissue weights were noticeably decreased in HFD rats treated with both extracts and ATOR. Added to that, biochemical and metabolic changes were normalized by significant attenuation of lipid peroxidation accompanied with an increase of thiol-group concentrations and antioxidant status. More importantly, a modulation in trace element levels was revealed when compared with HFD group. Altogether, current study concluded that AUAE and CMAE could be potential candidates for the prevention and treatment of obesity and related disturbs induced by HFD.

Targeting mitochondrial impairment for the treatment of cardiovascular diseases: From hypertension to ischemia-reperfusion injury, searching for new pharmacological targets

Mitochondria and mitochondrial proteins represent a group of promising pharmacological target candidates in the search of new molecular targets and drugs to counteract the onset of hypertension and more in general cardiovascular diseases (CVDs). Indeed, several mitochondrial pathways result impaired in CVDs, showing ATP depletion and ROS production as common traits of cardiac tissue degeneration. Thus, targeting mitochondrial dysfunction in cardiomyocytes can represent a successful strategy to prevent heart failure. In this context, the identification of new pharmacological targets among mitochondrial proteins paves the way for the design of new selective drugs. Thanks to the advances in omics approaches, to a greater availability of mitochondrial crystallized protein structures and to the development of new computational approaches for protein 3D-modelling and drug design, it is now possible to investigate in detail impaired mitochondrial pathways in CVDs. Furthermore, it is possible to design new powerful drugs able to hit the selected pharmacological targets in a highly selective way to rescue mitochondrial dysfunction and prevent cardiac tissue degeneration. The role of mitochondrial dysfunction in the onset of CVDs appears increasingly evident, as reflected by the impairment of proteins involved in lipid peroxidation, mitochondrial dynamics, respiratory chain complexes, and membrane polarization maintenance in CVD patients. Conversely, little is known about proteins responsible for the cross-talk between mitochondria and cytoplasm in cardiomyocytes. Mitochondrial transporters of the SLC25A family, in particular, are responsible for the translocation of nucleotides (e.g., ATP), amino acids (e.g., aspartate, glutamate, ornithine), organic acids (e.g. malate and 2-oxoglutarate), and other cofactors (e.g., inorganic phosphate, NAD⁺, FAD, carnitine, CoA derivatives) between the mitochondrial and cytosolic compartments. Thus, mitochondrial transporters play a key role in the mitochondria-cytosol cross-talk by leading metabolic pathways such as the malate/aspartate shuttle, the carnitine shuttle, the ATP export from mitochondria, and the regulation of permeability transition pore opening. Since all these pathways are crucial for maintaining healthy cardiomyocytes, mitochondrial carriers emerge as an interesting class of new possible pharmacological targets for CVD treatments.

Ferroptosis: a potential therapeutic target for Alzheimer's disease

The most prevalent dementia-causing neurodegenerative condition is Alzheimer's disease (AD). The aberrant buildup of amyloid β and tau hyperphosphorylation are the two most well-known theories about the mechanisms underlying AD development. However, a significant number of pharmacological clinical studies conducted around the world based on the two aforementioned theories have not shown promising outcomes, and AD is still not effectively treated. Ferroptosis, a non-apoptotic programmed cell death defined by the buildup of deadly amounts of iron-dependent lipid peroxides, has received more attention in recent years. A wealth of data is emerging to support the role of iron in the pathophysiology of AD. Cell line and animal studies applying ferroptosis modulators to the treatment of AD have shown encouraging results. Based on these studies, we describe in this review the underlying mechanisms of ferroptosis; the role that ferroptosis plays in AD pathology; and summarise some of the research advances in the treatment of AD with ferroptosis modulators. We hope to contribute to the clinical management of AD.

Single and Combined Associations of Plasma and Urine Essential Trace Elements (Zn, Cu, Se, and Mn) with Cardiovascular Risk Factors in a Mediterranean Population

Trace elements are micronutrients that are required in very small quantities through diet but are crucial for the prevention of acute and chronic diseases. Despite the fact that initial studies demonstrated inverse associations between some of the most important essential trace elements (Zn, Cu, Se, and Mn) and cardiovascular disease, several recent studies have reported a direct association with cardiovascular risk factors due to the fact that these elements can act as both antioxidants and pro-oxidants, depending on several factors. This study aims to investigate the association between plasma and urine concentrations of trace elements and cardiovascular risk factors in a general population from the Mediterranean region, including 484 men and women aged 18−80 years and considering trace elements individually and as joint exposure. Zn, Cu, Se, and Mn were determined in plasma and urine using an inductively coupled plasma mass spectrometer (ICP-MS). Single and combined analysis of trace elements with plasma lipid, blood pressure, diabetes, and anthropometric variables was undertaken. Principal component analysis, quantile-based g-computation, and calculation of trace element risk scores (TERS) were used for the combined analyses. Models were adjusted for covariates. In single trace element models, we found statistically significant associations between plasma Se and increased total cholesterol and systolic blood pressure; plasma Cu and increased triglycerides and body mass index; and urine Zn and increased glucose. Moreover, in the joint exposure analysis using quantile g-computation and TERS, the combined plasma levels of Zn, Cu, Se (directly), and Mn (inversely) were strongly associated with hypercholesterolemia (OR: 2.03; 95%CI: 1.37−2.99; p < 0.001 per quartile increase in the g-computation approach). The analysis of urine mixtures revealed a significant relationship with both fasting glucose and diabetes (OR: 1.91; 95%CI: 1.01−3.04; p = 0.046). In conclusion, in this Mediterranean population, the combined effect of higher plasma trace element levels (primarily Se, Cu, and Zn) was directly associated with elevated plasma lipids, whereas the mixture effect in urine was primarily associated with plasma glucose. Both parameters are relevant cardiovascular risk factors, and increased trace element exposures should be considered with caution.