Myeloperoxidase As a Multifaceted Target for Cardiovascular Protection

Transforming Growth Factor-β-mediated attenuation of cardio-renal oxidative stress, inflammation and fibrosis by L-arginine in fludrocortisone acetate induced-hypertensive rats

Uncontrolled hypertension is a primary contributor to tissue damage in multiple organs, including the heart and kidneys. In this study, we explored the protective roles of L-arginine in a mineralocorticoid-induced rat model of hypertension. To induce hypertension and subsequent organ damage, rats were nephrectomized unilaterally and fed with the mineralocorticoid fludrocortisone acetate and dietary salt (FCA-Salt). These rats were treated with L-arginine for 28 days, and subsequent tests were performed. Biochemical analysis revealed the increased level of inflammation and oxidative stress biomarkers in the plasma, heart, and kidney of the FCA-salt-treated rats. L-arginine treatment decreased the oxidative stress marker malondialdehyde (MDA) by 18 %, 22 %, and 18 % in the heart, kidney, and plasma, respectively. L-arginine also attenuated the advanced oxidative protein products (AOPP). The activity of superoxide dismutase (SOD) increased by 62 %, 45 %, and 16 % in the heart, kidney, and plasma, respectively, in the L-arginine-treated animals compared to the FCA-Salt group. Significant augmentation was also revealed for the nitric oxide (NO), catalase (CAT), and reduced glutathione (GSH). The plasma levels of the kidney function biomarkers uric acid and creatinine were significantly improved after L-arginine treatment. Furthermore, L-arginine remarkably reduced the elevated plasma cytokines IL-1β, IL-17A, TNF-α, and TGF-β1 in FCA-salt-induced hypertensive rats. Histopathological data showed a reduction in fibrosis and tissue damage by L-arginine in the FCA-salt-treated group. We propose that L-arginine could be an effective agent in preventing cardiac and renal dysfunction in hypertensive rats.

Epigallocatechin-3-gallate as an effective inhibitor of vascular endothelial dysfunction induced by endothelial-localized myeloperoxidase

In inflammatory vasculature, the leukocyte-released myeloperoxidase (MPO) is internalized by endothelial cells and this enzyme promotes endothelial dysfunction by catalytically producing strong oxidant, hypochlorous acid (HOCl). Herein, we developed epigallocatechin-3-gallate (EGCG, the main polyphenolic flavonoid found in green tea) as a novel endothelial-targeted MPO inhibitor. It was shown that culture of MPO and EGCG with vascular endothelial cells could result in their transport into the sub-endothelial space. EGCG significantly suppressed the consumption of enzyme's substrate H2O2 and generation of HOCl catalyzed by endothelial-transcytosed MPO. The binding of EGCG to the hydrophobic domain near the distal active heme cavity of enzyme was proposed by molecular docking and was suggested for the inhibitive effect of flavonoid on MPO activity. In vivo, EGCG attenuated lipopolysaccharide (LPS)-induced endothelial dysfunction in mouse aortas, while it inhibited the infiltration of active MPO into vascular walls. Furthermore, MPO-deficient mice were resistant to the protective effects of EGCG on LPS-induced vascular dysfunction, as compared to wild-type mice. These studies showed that EGCG effectively inhibited local oxidative reactions and endothelial dysfunction catalyzed by vascular-bound MPO. EGCG represents a versatile class of natural antioxidant drugs applicable to target endothelial-transcytosed MPO in inflammatory vasculature.

Association between serum myeloperoxidase enzyme activity and Parkinson's disease status

Elevated levels of the inflammatory enzyme myeloperoxidase (MPO) in the blood are associated with the development of age-related inflammatory diseases. Given that age, inflammation, and blood MPO play a role in the pathogenesis of Parkinson´s disease (PD), we hypothesized that serum MPO could be associated with PD status. This case-control study (199 participants) was conducted using an extensive protocol, and the concentration and activity of MPO in blood serum were measured. The findings reveal that serum MPO concentration and activity are significantly increased in the patients, and that rates of PD in all individuals are associated with increasing tertiles of MPO concentration and activity. In multivariate logistic regression model adjusting for confounding factors, MPO activity (not concentration) is the factor that is most associated with PD status (OR, 6.921, P = 0.001). Mental depression is directly associated with MPO activity and with PD status (OR, 0.121, B = -2.108, P = 0.002). The use of statins or nonsteroidal anti-inflammatory drugs significantly reduces serum MPO activity, but the possible association with the odds of having PD does not survive correction for multiple testing. In summary, both serum MPO concentration and activity are increased in patients with PD, but only MPO enzyme activity is associated with PD status. These findings may have implications for the evaluation of PD.

Clinical value of NT-proBNP, MPO, and NLR combined with echocardiography in prediction of malignant arrhythmia in elderly patients with valvular heart disease

OBJECTIVE

We aimed to probe the clinical value of N-terminus pro-brain natriuretic peptide (NT-proBNP), myeloperoxidase (MPO), and neutrophil lymphocyte ratio (NLR) combined with echocardiography in the prediction of malignant arrhythmias (MA) in elderly patients with valvular heart disease (VHD).

METHODS

MPO, NT-proBNP, and NLR were detected in blood samples. After 1 year of follow-up, receiver operating characteristic curves were analyzed to determine the clinical value of NT-proBNP, MPO, NLR, and echocardiography for predicting MA in patients with VHD.

RESULTS

MPO, NT-proBNP, and NLR were higher in the VHD group. MPO, NT-proBNP, and NLR were higher with severe cardiac dysfunction. MPO, NT-proBNP, NLR, and LVESV in the MA group were higher. NT-proBNP was an independent factor influencing the occurrence of MA in elderly patients with VHD. The AUC for predicting MA in elderly patients with VHD using NT-proBNP, MPO, NLR, and echocardiography were 0.782 (sensitivity 61.50%, specificity 94.60%, 95% CI 0.630-0.934), 0.759 (sensitivity 69.20%, specificity 81.10%, 95% CI 0.579-0.938), 0.736 (sensitivity 76.90%, specificity 64.90%, 95% CI 0.562-0.910), and 0.782 (sensitivity 76.90%, specificity 75.70%, 95% CI 0.646-0.918), respectively. The AUC for the combined prediction using NT-proBNP, MPO, NLR, and echocardiography was 0.913 (sensitivity 76.90%, specificity 94.60%, 95% CI 0.820-1.000), higher than that of each parameter alone (P < 0.05).

CONCLUSION

The combination of NT-proBNP, MPO, NLR, and echocardiography has a predictive value in detecting MA in elderly VHD patients.

Involvement of purinergic signalling in the vasomotor response to hypochlorous acid in porcine coronary artery

Hypochlorous acid (HOCl) is generated by neutrophils during the innate immune response. ATP is released from cells by various stimuli and during inflammation but whether ATP is released by and participates in the response to HOCl is unclear. This study investigated vasomotor effects of HOCl on the porcine coronary artery (PCA) and the involvement of ATP and purine receptors. HOCl at 100 μM induced rapid and transient endothelium-dependent relaxation followed by slow and sustained endothelium-independent relaxation. Transient endothelium-dependent relaxation was induced by 500 μM HOCl, followed by endothelium-dependent contraction, then slow endothelium-independent relaxation. 8-(p-sulphophenyl)theophylline (8-SPT), an adenosine/P1 receptor antagonist, blocked rapid relaxation and contraction to HOCl but an A2A receptor antagonist, ZM 241385, and an A1 receptor antagonist, DPCPX, had no effect. Suramin, a P2 receptor antagonist (and membrane channel inhibitor), blocked rapid relaxation (at 100 μM HOCl) and contraction to HOCl. Other antagonists for P2, P2X1, P2Y1 and P2X4 receptors (PPADS, reactive blue 2, NF449, MRS2179 and BX430) did not affect HOCl responses. Relaxation to exogenous ATP was inhibited by 8-SPT but not by suramin suggesting that suramin block of HOCl responses may involve inhibition of membrane channels and endogenous ATP release. Apyrase, which hydrolyzes nucleotides, abolished responses to HOCl, ATP and unexpectedly adenosine. Neither probenecid nor carbenoxelone (connexin and pannexin channel inhibitors) blocked responses to HOCl. Luminescent ATP assay showed that HOCl elicited ATP release from cultures of human coronary artery endothelial cells. These findings advance our understanding of inflammation by showing that HOCl evokes endothelium-dependent vasorelaxation and contraction in coronary arteries which may involve P1 receptors implicating endogenous adenosine, possibly generated from rapid metabolism of ATP released by HOCl.

In Situ Metal-Organic Framework Growth in Serum Encapsulates and Depletes Abundant Proteins for Integrated Plasma Proteomics

Protein biomarkers in human serum provide critical insights into various physiological conditions and diseases, enabling early diagnosis, prognosis, and personalized treatment. However, detecting low-abundance protein biomarkers is challenging due to the presence of highly abundant proteins that make up ∼99% of the plasma proteome. Here, we report the use of in situ metal-organic framework (MOF) growth in serum to effectively deplete highly abundant serum proteins for integrated proteomic analysis. Through biomolecule-mediated nucleation of a zeolitic imidazolate framework (ZIF-8), abundant plasma proteins are selectively encapsulated within ZIF-8 and removed from serum via centrifugation, leaving a depleted protein fraction in the supernatant. Bottom-up proteomics analysis confirmed significant depletion of the topmost abundant proteins, many at depletion levels exceeding 95%. Such depletion enabled the identification of 277 total proteins in the supernatant (uncaptured) fraction in a single-shot analysis, including 54 proteins that were only identified after depletion, 12 drug targets, and many potential disease biomarkers. Top-down proteomics characterization of the captured and uncaptured protein fractions at the proteoform-level confirmed this method is not biased toward any specific proteoform of individual proteins. These results demonstrate that in situ MOF growth can selectively and effectively deplete high-abundance proteins from serum in a simple, low cost, one-pot synthesis to enable integrated top-down and bottom-up proteomic analysis of serum protein biomarkers.

Association of MPO levels with cardiometabolic disease stratified by atherosclerotic cardiovascular risk and intensity of therapy in a workforce population

Cardiometabolic risk increases cardiovascular (CVD), chronic kidney (CKD) and non-alcoholic fatty liver (NAFLD) disease risk. High myeloperoxidase (MPO) levels identify individuals at risk for CVD. We whether elevation of MPO associated with kidney and liver disease risk in subgroups stratified by ASCVD risk and intensity of therapy. Adjusted logistic models assessed the associations of MPO with markers of kidney disease (estimated glomerular filtration rate) and liver fibrosis (NAFLD score > 0.676 or Fibrosis-4 [FIB-4] score > 2.67) across ASCVD risk (low < 7.5%; intermediate 7.5% to < 20%; high ≥ 20%). This retrospective study comprised 20,772 participants in an employer-sponsored health assessment. High MPO associated with impaired kidney function with low (OR 2.2, 95% CI 1.6-3.7) and intermediate (OR 2.0, 95% CI 1.3-3.5) ASCVD risk, and with high FIB-4 or NAFLD scores in low (OR 2.4, 95% CI 1.2-4.7), intermediate (OR 3.1, 95% CI 2.0-6.0), and high (OR 3.8, 95% CI 2.9-7.4) ASCVD risk groups. High MPO was associated with markers of CKD and liver fibrosis in low to intermediate ASCVD risk and treated groups. These findings demonstrate the commonality of cardiometabolic biomarkers across multiple organs.   Prospective studies are warranted to assess whether high MPO levels identify persons at risk for CKD and liver fibrosis who may benefit from preventive strategies.

MPO and its role in cancer, cardiovascular and neurological disorders: An update

Myeloperoxidase (MPO) is an enzyme that contains a heme group, found mostly in neutrophils and in small amounts in monocytes and plays a major role in their anti-microbial activity. However, excessive levels of MPO have been linked to various disorders and identified as a major cause of tissue destruction. Inhibiting its activity can reduce the severity and extent of tissue damage. Over activity of MPO during chronic inflammation has been shown to be involved in tumorigenesis by inducing a hyper-mutagenic environment through oxidant interaction with DNA, causing DNA modification. Vascular endothelium is one of the most important targets of MPO and high levels have been associated with increased rates of cardiomyopathy, ischemic stroke, heart failure, myocardial infarction, and atrial fibrillation. Therefore, it may be considered a therapeutic target in the treatment of cardiovascular disorders. MPO also participates in the pathogenesis of neurodegenerative diseases. For example, an increase in MPO levels has been observed in the brain tissue of patients with Alzheimer's, Multiple sclerosis (MS), and Parkinson's diseases. In Alzheimer's disease, active MPO is mostly found in the location of beta amyloids and microglia. Therefore, targeting MPO may be a potential treatment and prevention strategy for neurological disorders. This review will discuss MPO's physiological and pathological role in cancer, cardiovascular, and neurological disorders.

miR-203 Alleviates Myocardial Damage Caused by Acute Coronary Syndrome by Inhibiting CA125

Acute coronary syndrome (ACS) is a significant contributor to cardiovascular mortality. Research has indicated that CA125 levels are linked to cardiovascular disease. This study aimed to explore the role of CA125 in ACS and its underlying mechanism. A retrospective study was conducted involving 34 healthy volunteers and 46 patients diagnosed with ACS. Clinical characteristics and CA125 expression were recorded and detected. Bioinformatics analysis was performed to identify miRNAs that regulate CA125. HL-1 cardiac muscle cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to investigate the role of CA125 in myocardial injury. An ACS mice model was constructed to further explore the role of CA125 on ACS. The levels of serum creatinine, blood urea nitrogen, uric acid, high-sensitivity C-reactive protein, cystatin C, and white blood cells in ACS were markedly higher than those in healthy volunteers. CA125 was up-regulated in ACS and was a target of miR-203. Injection of miR-203 agomir reduced plaque deposition and vascular thrombosis in the coronary lumen, alleviating myocardial damage. Additionally, miR-203 inhibited myocardial apoptosis and inflammation responses induced by OGD/R and ACS. miR-203 can reduce the inflammatory response by inhibiting CA125 expression, thereby improving ACS symptoms and mitigating ACS-induced myocardial injury.

In Situ Imaging of Cellular Inflammatory Response to Antibiotic Exposure with a DNAzyme Nanorobot

Antibiotic-induced inflammation involves the release of myeloperoxidase (MPO), an enzyme whose expression in tissues is associated with the inflammatory pathway. However, existing methods for detecting MPO in cells are limited. In this study, a DNAzyme nanorobot was developed using a scaffold of gold nanoparticles (AuNPs) decorated with functional DNAzyme strands and their fluorophore-labeled substrate strands. The DNAzyme remains inactive due to a self-assembled hairpin structure, with a phosphorothioate (PT) modification inserted into the stem domain. When MPO is present, it triggers a halogenation process that generates hypochlorous acid (HClO). HClO specifically catalyzes the cleavage of the PT-site, releasing free DNAzyme strands to cleave their substrates and generating an increasing fluorescent signal. The detection limit for MPO and its primary product, HClO, were determined to be 0.038 μg/mL and 0.013 μM, respectively. The DNAzyme nanorobot can be readily introduced into cells and function autonomously to differentiate increased MPO/HClO levels caused by antibiotics. This approach was applied to image RAW264.7 cells exposed to four prevalent antibiotics found in the environment (phorbol 12-myristate 13-acetate, erythromycin, penicillin, and tetracycline) as well as antibiotic production wastewater. This nanorobot offers novel strategies for monitoring inflammation to evaluate the health impacts of antibiotic exposure.

Heart failure with preserved ejection fraction: The role of inflammation

Heart failure (HF) is a debilitating clinical syndrome affecting 64.3 million patients worldwide. More than 50% of HF cases are attributed to HF with preserved ejection fraction (HFpEF), an entity growing in prevalence and mortality. Although recent breakthroughs reveal the prognostic benefits of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in HFpEF, there is still a lack of effective pharmacological therapy available. This highlights a major gap in medical knowledge that must be addressed. Current evidence attributes HFpEF pathogenesis to an interplay between cardiometabolic comorbidities, inflammation, and renin-angiotensin-aldosterone-system (RAAS) activation, leading to cardiac remodelling and diastolic dysfunction. However, conventional RAAS blockade has demonstrated limited benefits in HFpEF, which emphasises that alternative therapeutic targets should be explored. Presently, there is limited literature examining the use of anti-inflammatory HFpEF therapies despite growing evidence supporting its importance in disease progression. Hence, this review aims to explore current perspectives on HFpEF pathogenesis, including the importance of inflammation-driven cardiac remodelling and the therapeutic potential of anti-inflammatory therapies.

Development and validation of a nomogram to predict severe influenza

BACKGROUND

Influenza is an acute respiratory disease posing significant harm to human health. Early prediction and intervention in patients at risk of developing severe influenza can significantly decrease mortality.

METHOD

A comprehensive analysis of 146 patients with influenza was conducted using the Gene Expression Omnibus (GEO) database. We assessed the relationship between severe influenza and patients' clinical information and molecular characteristics. First, the variables of differentially expressed genes were selected using R software. Least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis were performed to investigate the association between clinical information and molecular characteristics and severe influenza. A nomogram was developed to predict the presence of severe influenza. At the same time, the concordance index (C-index) is adopted area under the receiver operating characteristic (ROC), area under the curve (AUC), decision curve analysis (DCA), and calibration curve to evaluate the predictive ability of the model and its clinical application.

RESULTS

Severe influenza was identified in 47 of 146 patients (32.20%) and was significantly related to age and duration of illness. Multivariate logistic regression demonstrated significant correlations between severe influenza and myloperoxidase (MPO) level, haptoglobin (HP) level, and duration of illness. A nomogram was formulated based on MPO level, HP level, and duration of illness. This model produced a C-index of 0.904 and AUC of 0.904.

CONCLUSIONS

A nomogram based on the expression levels of MPO, HP, and duration of illness is an efficient model for the early identification of patients with severe influenza. These results will be useful in guiding prevention and treatment for severe influenza disease.

Causal relationship between inflammatory markers and left ventricle geometry and function: A 2-sample Mendelian randomization study

Studies have shown that some inflammatory markers can predict the risk of cardiovascular disease (CVD) and affect the structure and function of the heart. However, a causal relationship between inflammatory markers and the cardiac structure and function has not yet been established. Thus, we conducted a 2-sample Mendelian randomization (MR) study to explore the potential causal relationship between inflammatory markers and prognostically-related left ventricular (LV) parameters. Instrumental variables (IVs) for C-reactive protein (CRP), interleukin-6 (IL-6), and myeloperoxidase (MPO) levels were selected from the databases of large genome-wide association studies (GWAS). Summary statistics for LV parameters, including LV mass, ejection fraction, end-diastolic and systolic volumes, and the ratio of LV mass to end-diastolic volume, were obtained from cardiovascular magnetic resonance studies of the UK Biobank (n = 16923). The inverse-variance weighted (IVW) method was the primary analytical method used, and was complemented with the MR-Egger, weighted median, simple mode, weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO) methods. Sensitivity analysis was performed to evaluate the robustness of the results. CRP was significantly associated with the LV mass in the IVW method (β = -0.13 g [95% confidence interval [CI], 0.78 g-1.00 g], P = .046). A higher standard deviation of genetically-predicted CRP levels was associated with a 0.13 ± 0.06 g lower LV mass. No causal relationships of IL-6 and MPO with LV parameters were found. No evidence of heterogeneity and pleiotropy was detected. Sensitivity analyses confirmed the robustness of the results. Two-sample MR analysis revealed a causal association between increased CRP level and decreased LV mass, whereas IL-6 and MPO levels did not influence the LV parameters. However, further research is required to validate our findings.

RNAseq of INOCA patients identifies innate, invariant, and acquired immune changes: potential autoimmune microvascular dysfunction

Background

Ischemia with non-obstructive coronary arteries (INOCA) is a major clinical entity that involves potentially 20%-30% of patients with chest pain. INOCA is typically attributed either to coronary microvascular disease and/or vasospasm, but is likely distinct from classical coronary artery disease (CAD).

Objectives

To gain insights into the etiology of INOCA and CAD, RNA sequencing of whole blood from patients undergoing both stress testing and elective invasive coronary angiography (ICA) was conducted.

Methods

Stress testing and ICA of 177 patients identified 40 patients (23%) with INOCA compared to 39 controls (stress-, ICA-). ICA+ patients divided into 38 stress- and 60 stress+. RNAseq was performed by Illumina with ribosomal RNA depletion. Transcriptome changes were analyzed by DeSeq2 and curated by manual and automated methods.

Results

Differentially expressed genes for INOCA were associated with elevated levels of transcripts related to mucosal-associated invariant T (MAIT) cells, plasmacytoid dendritic cells (pcDC), and memory B cells, and were associated with autoimmune diseases such as rheumatoid arthritis. Decreased transcripts were associated with neutrophils, but neutrophil transcripts, per se, were not less abundant in INOCA. CAD transcripts were more related to T cell functions.

Conclusions

Elevated transcripts related to pcDC, MAIT, and memory B cells suggest an autoimmune component to INOCA. Reduced neutrophil transcripts are likely attributed to chronic activation leading to increased translation and degradation. Thus, INOCA could result from stimulation of B cell, pcDC, invariant T cell, and neutrophil activation that compromises cardiac microvascular function.

Postantibiotic leukocyte enhancement-mediated reduction of intracellular bacteria by macrophages

INTRODUCTION

Potentiation of the bactericidal activities of leukocytes, including macrophages, upon antibacterial agent administration has been observed for several decades and is summarized as the postantibiotic leukocyte enhancement (PALE) theory. Antibiotics-induced bacterial sensitization to leukocytes is commonly recognized as the mechanism of PALE. However, the degree of sensitization drastically varies with antibiotic classes, and little is known about whether and how the potentiation of leukocytes contributes to PALE.

OBJECTIVES

In this study, we aim to develop a mechanistic understanding of PALE by investigating the immunoregulation of traditional antibiotics on macrophages.

METHODS

Interaction models between bacteria and macrophages were constructed to identify the effects of different antibiotics on the bactericidal activities of macrophages. Oxygen consumption rate, expression of oxidases, and antioxidants were then measured to evaluate the effects of fluoroquinolones (FQs) on the oxidative stress of macrophages. Furthermore, the modulation in endoplasmic reticulum stress and inflammation upon antibiotic treatment was detected to analyze the mechanisms. At last, the peritoneal infection model was utilized to verify the PALE in vivo.

RESULTS

Enrofloxacin significantly reduced the intracellular burden of diverse bacterial pathogens through promoting the accumulation of reactive oxygen species (ROS). The upregulated oxidative response accordingly reprograms the electron transport chain with decreased production of antioxidant enzymes to reduce internalized pathogens. Additionally, enrofloxacin modulated the expression and spatiotemporal localization of myeloperoxidase (MPO) to facilitate ROS accumulation to target invaded bacteria and downregulated inflammatory response to alleviate cellular injury.

CONCLUSION

Our findings demonstrate the crucial role of leukocytes in PALE, shedding light on the development of new host-directed antibacterial therapies and the design of rational dosage regimens.

Expanding the Frontiers of Guardian Antioxidant Selenoproteins in Cardiovascular Pathophysiology

Significance: Physiological levels of reactive oxygen and nitrogen species (ROS/RNS) function as fundamental messengers for many cellular and developmental processes in the cardiovascular system. ROS/RNS involved in cardiac redox-signaling originate from diverse sources, and their levels are tightly controlled by key endogenous antioxidant systems that counteract their accumulation. However, dysregulated redox-stress resulting from inefficient removal of ROS/RNS leads to inflammation, mitochondrial dysfunction, and cell death, contributing to the development and progression of cardiovascular disease (CVD). Recent Advances: Basic and clinical studies demonstrate the critical role of selenium (Se) and selenoproteins (unique proteins that incorporate Se into their active site in the form of the 21st proteinogenic amino acid selenocysteine [Sec]), including glutathione peroxidase and thioredoxin reductase, in cardiovascular redox homeostasis, representing a first-line enzymatic antioxidant defense of the heart. Increasing attention has been paid to emerging selenoproteins in the endoplasmic reticulum (ER) (i.e., a multifunctional intracellular organelle whose disruption triggers cardiac inflammation and oxidative stress, leading to multiple CVD), which are crucially involved in redox balance, antioxidant activity, and calcium and ER homeostasis. Critical Issues: This review focuses on endogenous antioxidant strategies with therapeutic potential, particularly selenoproteins, which are very promising but deserve more detailed and clinical studies. Future Directions: The importance of selective selenoproteins in embryonic development and the consequences of their mutations and inborn errors highlight the need to improve knowledge of their biological function in myocardial redox signaling. This could facilitate the development of personalized approaches for the diagnosis, prevention, and treatment of CVD. Antioxid. Redox Signal. 40, 369-432.

Ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) associated with pro-thrombotic biomarkers among young healthy adults: A 16 times repeated measurements panel study

Studies have shown that the cardio/cerebrovascular toxicity of ambient PM2.5 is related to its bound polycyclic aromatic hydrocarbons (PAHs). Currently, only a few studies have reported the relationship between PM2.5-bound PAHs and promoted blood coagulation and thrombosis, but there isn't a consistent conclusion. Therefore, we conducted a prospective panel study to investigate the association. Thirty-three young healthy adults participated in sixteen repeated visits from 2014 to 2018 in Tianjin, China. During each visit, three pro-thrombotic biomarkers: ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motif 13), D-dimer and Myeloperoxidase (MPO) were measured. Before each visit, ambient PM2.5 samples were daily collected for one week. Sixteen PAHs were determined using Gas Chromatography-Mass Spectrometer, and the positive matrix factorization (PMF) model was applied to identify the sources. Linear mixed-effects models were fitted to investigate the associations between PM2.5-bound PAHs exposure and the biomarkers. Thirteen time-metrics were defined to identify significant time points of PM2.5-bound PAHs' effects. We observed that the increase of PM2.5-bound PAHs exposure was significantly associated with reduced ADAMTS13, elevated D-dimer and MPO. At lag0, each 5.7 ng/m3 increase in Benzo[j]fluoranthene and per 3.4 ng/m3 increase Dibenz[a,h]anthracene could make a maximum change of -19.08 % in ADAMTS13 and 132.60 % in D-dimer. Additionally, per 16.43 ng/m3 increase in Chrysene could lead to a maximum elevation of 32.14 % in MPO at lag4. The PM2.5-bound PAHs often triggered more significant changes at lag 3,4 and 6. The ambient PM2.5-bound PAHs originated from six sources: coal combustion (43.10 %), biomass combustion (20.77 %), diesel emission (14.78 %), gasoline emission (10.95 %), industrial emission (7.58 %), and cooking emission (2.83 %). The greatest contributors to alterations in ADAMTS13, D-dimer and MPO are industrial emission (-48.43 %), biomass combustion (470.32 %) and diesel emission (13.14 %) at lag4. Our findings indicated that short-term exposure to ambient PM2.5-bound PAHs can induce alterations of pro-thrombotic biomarkers among healthy adults.

Plasma proteins as potential biomarkers of aging of single tissue and cell type

Plasma proteins serve as biomarkers of aging and various age-related diseases. While a number of plasma proteins have been identified that increase or decrease with age, the interpretation of each protein is challenging. This is due to the nature of plasma, which is a mixture of factors secreted by many different tissues and cells. Therefore, the catalog of age-related proteins secreted by a single cell type in a single tissue would be useful for understanding tissue-specific aging patterns. In this study, the author addressed this challenge by integrative data mining of the Human Protein Atlas and the recently published result of large-scale aging proteomics research. Finally, we identified the 17 age-related proteins produced by a single tissue and a single cell type: MBL2 and HP in the liver (hepatocytes), SFTPC in the lung (type II alveolar cells), PRL and POMC in the pituitary (anterior cells), GCG, CUZD1 and CPA2 in the pancreas (pancreatic cells), MYBPC1 in skeletal muscle (myocytes), PTH in the parathyroid gland (glandular cells), LPO and AMY1A in the salivary gland (glandular cells), INSL3 in the male testis (Leydig cells), KLK3 and KLK4 in the male prostate (glandular cells), MPO and ACP5 in immune cells. This list of proteins would be potentially useful for understanding age-related changes in the plasma proteome and inter-tissue networks.

Inflammation in Heart Failure-Future Perspectives

Chronic heart failure is a terminal point of a vast majority of cardiac or extracardiac causes affecting around 1-2% of the global population and more than 10% of the people above the age of 65. Inflammation is persistently associated with chronic diseases, contributing in many cases to the progression of disease. Even in a low inflammatory state, past studies raised the question of whether inflammation is a constant condition, or if it is, rather, triggered in different amounts, according to the phenotype of heart failure. By evaluating the results of clinical studies which focused on proinflammatory cytokines, this review aims to identify the ones that are independent risk factors for heart failure decompensation or cardiovascular death. This review assessed the current evidence concerning the inflammatory activation cascade, but also future possible targets for inflammatory response modulation, which can further impact the course of heart failure.

GYY4137, a hydrogen sulfide donor, protects against endothelial dysfunction in porcine coronary arteries exposed to myeloperoxidase and hypochlorous acid

BACKGROUND AND AIMS

Myeloperoxidase (MPO) and its principal reaction product hypochlorous acid (HOCl) are part of the innate immune response but are also associated with endothelial dysfunction, thought to involve a reduction in nitric oxide (NO) bioavailability. We aimed to investigate the effect of MPO and HOCl on vasorelaxation of coronary arteries and to assess directly the involvement of NO. In addition, we hypothesised that the slow release hydrogen sulfide (H2S) donor GYY4137 would salvage coronary artery endothelial function in the presence of MPO and HOCl.

METHODS AND RESULTS

Contractility of porcine coronary artery segments was measured using isometric tension recording. Incubation with MPO (50 ng/ml) plus hydrogen peroxide (H2O2) (30 μM; substrate for MPO) impaired endothelium-dependent vasorelaxation to bradykinin in coronary arteries. HOCl (10-500 μM) also impaired endothelium-dependent relaxations. There was no effect of MPO plus H2O2, or HOCl, on endothelium-independent relaxations to 5'-N-ethylcarboxamidoadenosine and sodium nitroprusside. L-NAME (300 μM), a NO synthase inhibitor, attenuated bradykinin relaxations, leaving L-NAME-resistant relaxations to bradykinin mediated by endothelium-dependent hyperpolarization. In the presence of L-NAME, MPO plus H2O2 largely failed to impair endothelium-dependent relaxations to bradykinin. Similarly, HOCl failed to inhibit endothelium-dependent relaxations to bradykinin in the presence of L-NAME. GYY4137 (1-100 μM) protected endothelium-dependent relaxations to bradykinin from dysfunction caused by MPO plus H2O2, and HOCl, with no effect alone on bradykinin relaxation responses. The specific MPO inhibitor aminobenzoic acid hydrazide (ABAH) (1 and 10 μM) also protected against MPO plus H2O2-induced endothelial dysfunction (at 10 μM ABAH), but was less potent than GYY4137.

CONCLUSIONS

MPO plus H2O2, and HOCl, impair coronary artery endothelium-dependent vasorelaxation via inhibition of NO. GYY4137 protects against endothelial dysfunction in arteries exposed to MPO plus H2O2, and HOCl. H2S donors such as GYY4137 are possible therapeutic options to control excessive MPO activity in cardiovascular diseases.

Novel Biomarkers and Their Role in the Diagnosis and Prognosis of Acute Coronary Syndrome

The burden of cardiovascular diseases and the critical role of acute coronary syndrome (ACS) in their progression underscore the need for effective diagnostic and prognostic tools. Biomarkers have emerged as crucial instruments for ACS diagnosis, risk stratification, and prognosis assessment. Among these, high-sensitivity troponin (hs-cTn) has revolutionized ACS diagnosis due to its superior sensitivity and negative predictive value. However, challenges regarding specificity, standardization, and interpretation persist. Beyond troponins, various biomarkers reflecting myocardial injury, neurohormonal activation, inflammation, thrombosis, and other pathways are being explored to refine ACS management. This review article comprehensively explores the landscape of clinically used biomarkers intricately involved in the pathophysiology, diagnosis, and prognosis of ACS (i.e., troponins, creatine kinase MB (CK-MB), B-type natriuretic peptides (BNP), copeptin, C-reactive protein (CRP), interleukin-6 (IL-6), d-dimers, fibrinogen), especially focusing on the prognostic role of natriuretic peptides and of inflammatory indices. Research data on novel biomarkers (i.e., endocan, galectin, soluble suppression of tumorigenicity (sST2), microRNAs (miRNAs), soluble oxidized low-density lipoprotein receptor-1 (sLOX-1), F2 isoprostanes, and growth differentiation factor 15 (GDF-15)) are further analyzed, aiming to shed light on the multiplicity of pathophysiologic mechanisms implicated in the evolution of ACS. By elucidating the complex interplay of these biomarkers in ACS pathophysiology, diagnosis, and outcomes, this review aims to enhance our understanding of the evolving trajectory and advancements in ACS management. However, further research is necessary to establish the clinical utility and integration of these biomarkers into routine practice to improve patient outcomes.

Myeloperoxidase is a critical mediator of anthracycline-induced cardiomyopathy

Cardiotoxicity is a major complication of anthracycline therapy that negatively impacts prognosis. Effective pharmacotherapies for prevention of anthracycline-induced cardiomyopathy (AICM) are currently lacking. Increased plasma levels of the neutrophil-derived enzyme myeloperoxidase (MPO) predict occurrence of AICM in humans. We hypothesized that MPO release causally contributes to AICM. Mice intravenously injected with the anthracycline doxorubicin (DOX) exhibited higher neutrophil counts and MPO levels in the circulation and cardiac tissue compared to saline (NaCl)-treated controls. Neutrophil-like HL-60 cells exhibited increased MPO release upon exposition to DOX. DOX induced extensive nitrosative stress in cardiac tissue alongside with increased carbonylation of sarcomeric proteins in wildtype but not in Mpo-/- mice. Accordingly, co-treatment of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with DOX and MPO aggravated loss of hiPSC-CM-contractility compared to DOX treatment alone. DOX-treated animals exhibited pronounced cardiac apoptosis and inflammation, which was attenuated in MPO-deficient animals. Finally, genetic MPO deficiency and pharmacological MPO inhibition protected mice from the development of AICM. The anticancer efficacy of DOX was unaffected by MPO deficiency. Herein we identify MPO as a critical mediator of AICM. We demonstrate that DOX induces cardiac neutrophil infiltration and release of MPO, which directly impairs cardiac contractility through promoting oxidation of sarcomeric proteins, cardiac inflammation and cardiomyocyte apoptosis. MPO thus emerges as a promising pharmacological target for prevention of AICM.

Evaluation of Atherosclerotic Risk by Oxidative Contributors in Alcohol Use Disorder

Objective

Alcohol Use Disorder (AUD) is a condition described as the inability to control or stop alcohol consumption. The patients with AUD have an increased risk of developing atherosclerosis-related diseases. The present study aimed to evaluate oxidative contributors of atherosclerotic risk factors in patients with AUD.

Methods

The male subjects diagnosed with AUD (n = 45) and the male subjects as control (n = 35) were enrolled in this study. All participants were undergone psychiatric evaluation and sociodemographic tests. Also, serum oxidative contributors of atherosclerosis including myeloperoxidase (MPO), ferroxidase, catalase (CAT), and lipid hydroperoxides (LOOH) were measured. Additionally, serum lipid profile tests and atherogenic indicators including atherogenic index of plasma (AIP) and non-high-density lipoprotein (HDL) cholesterol were also analyzed.

Results

The AUD subject had significantly elevated MPO activity and LOOH levels with decreased antioxidant capacity. AIP and non-HDL cholesterol levels, the atherogenic indicators, were also higher in AUD group compared to the control group. We found the MPO activity and LOOH levels were positively correlated with AIP, non-HDL cholesterol levels, and amount of alcohol consumption. Additionally, CAT activity was negatively correlated with duration of alcohol consumption.

Conclusion

Our results revealed that MPO and LOOH levels were elevated by severe alcohol intake and the atherogenic indicators, AIP and non-HDL cholesterol, were significantly correlated alcohol induced elevated oxidative risk factors. Therefore, it can be suggested that MPO activity and LOOH levels may be useful to determine jeopardy of atherosclerotic and the therapeutic interventions that reduce oxidative load could be taken into account to prevent atherosclerotic diseases before clinical manifestation.

Psychobiotic interventions attenuate chronic alcohol use-mediated exacerbation of posttraumatic stress disorder in rats: the role of gut-liver axis response

OBJECTIVES

The incidence of co-occurring alcohol-use disorder (AUD) and post-traumatic stress disorder (PTSD) is high, and the presence of one disorder aggravates the severity of the other. Emerging evidence shows the neuroprotective and anti-inflammation functions of psychobiotics. Hence, the study explored the effects of probiotics and synbiotic inulin on the gut- and liver-oxidative and inflammatory biomarkers in chronic alcohol exacerbation of PTSD symptoms in rats.

METHODS

Young adult rats were administered 10% ethanol in a two-bottle choice test for six weeks and were subjected to single prolonged stress. Probiotics and synbiotic intervention followed this. Markers of oxido-inflammatory stress, liver functions, intestinal (faecal) metabolites, occludin expression, and histopathology of the ileum and liver were evaluated.

RESULTS

Chronic alcohol drinking and PTSD increased oxido-inflammatory stress, markers of hepatic damage, and reduced faecal metabolites, which were attenuated by probiotic and synbiotic interventions. Furthermore, reduced immunoexpression of gut and liver occludin, with loss of barrier integrity, viable hepatocytes, congestive portal area, and shortened villi and crypt depth, were observed. Probiotic and synbiotic interventions mitigated these effects.

CONCLUSIONS

The study demonstrates that psychobiotics mitigate the detrimental effects of co-occurring chronic alcohol intake in the context of PTSD.

Circulatory proteins relate cardiovascular disease to cognitive performance: A mendelian randomisation study

Background and objectives: Mechanistic research suggests synergistic effects of cardiovascular disease (CVD) and dementia pathologies on cognitive decline. Interventions targeting proteins relevant to shared mechanisms underlying CVD and dementia could also be used for the prevention of cognitive impairment. Methods: We applied Mendelian randomisation (MR) and colocalization analysis to investigate the causal relationships of 90 CVD-related proteins measured by the Olink CVD I panel with cognitive traits. Genetic instruments for circulatory protein concentrations were obtained using a meta-analysis of genome-wide association studies (GWAS) from the SCALLOP consortium (N = 17,747) based on three sets of criteria: 1) protein quantitative trait loci (pQTL); 2) cis-pQTL (pQTL within ±500 kb from the coding gene); and 3) brain-specific cis-expression QTL (cis-eQTL) which accounts for coding gene expression based on GTEx8. Genetic associations of cognitive performance were obtained from GWAS for either: 1) general cognitive function constructed using Principal Component Analysis (N = 300,486); or, 2) g Factor constructed using genomic structural equation modelling (N = 11,263-331,679). Findings for candidate causal proteins were replicated using a separate protein GWAS in Icelanders (N = 35,559). Results: A higher concentration of genetically predicted circulatory myeloperoxidase (MPO) was nominally associated with better cognitive performance (p < 0.05) using different selection criteria for genetic instruments. Particularly, brain-specific cis-eQTL predicted MPO, which accounts for protein-coding gene expression in brain tissues, was associated with general cognitive function (βWald = 0.22, PWald = 2.4 × 10-4). The posterior probability for colocalization (PP.H4) of MPO pQTL with the g Factor was 0.577. Findings for MPO were replicated using the Icelandic GWAS. Although we did not find evidence for colocalization, we found that higher genetically predicted concentrations of cathepsin D and CD40 were associated with better cognitive performance and a higher genetically predicted concentration of CSF-1 was associated with poorer cognitive performance. Conclusion: We conclude that these proteins are involved in shared pathways between CVD and those for cognitive reserve or affecting cognitive decline, suggesting therapeutic targets able to reduce genetic risks conferred by cardiovascular disease.

Identifying neutrophil-associated subtypes in ulcerative colitis and confirming neutrophils promote colitis-associated colorectal cancer

Background

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestinal mucosa, the incidence of which has increased worldwide. There is still a lack of clear understanding of the pathogenesis of ulcerative colitis that ultimately leads to colitis-associated colorectal cancer.

Method

We download UC transcriptome data from the GEO database and pass the limma package in order to identify differentially expressed genes. Gene Set Enrichment Analysis (GSEA) was used to identify potential biological pathways. We identified immune cells associated with UC by CIBERSORT and Weighted co-expression network analysis (WGCNA). We used validation cohorts and mouse models to verify the expression of the hub genes and the role of neutrophils.

Result

We identified 65 differentially expressed genes in UC samples and healthy controls. GSEA, KEGG, and GO analyses displayed that DEGs were enriched in immune-related pathways. CIBERSORT analysis revealed increased infiltration of neutrophils in UC tissues. The red module, obtained by WGCNA analysis, was considered to be the most relevant module for neutrophils.Based on neutrophil-associated differentially expressed genes, UC patients were classified into two subtypes of neutrophil infiltration. We discovered that the highly neutrophil-infiltrated subtype B of UC patients had a higher risk of developing CAC. Five genes were identified as biomarkers by searching for DEGs between distinct subtypes. Finally, using the mouse model, we determined the expression of these five genes in the control, DSS, and AOM/DSS groups. The degree of neutrophil infiltration in mice and the percentage of MPO and pSTAT3 expression in neutrophils were analyzed by flow cytometry. In the AOM/DSS model, MPO and pSTAT3 expressions were significantly increased.

Conclusions

These findings suggested neutrophils might promote the conversion of UC into CAC. These findings improve our understanding of the pathogenesis of CAC and provide new and more effective insights into the prevention and treatment of CAC.

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.

Age-Related Diseases and Foods Generating Chlorinative Stress

BACKGROUND

Aging is a slow and inexorable process affecting all life beings and is characterised by age-related worsening in adaptation to external changes. Several factors contribute to such a process, and oxidative stress due to external damages is one key player. Of particular interest is the oxidative stress generated from halogen compounds such as chloride. Hypochlorus acid is produced starting from MPO's interaction with hydrogen peroxide. We focused on the oxidation of tyrosine residues by HOCl, which leads as a result to the formation of 3-chlorotyrosine (3-ClTyr). This molecule, due to its stability, is considered a marker for MPO activity.

RESULTS

We collected data from literature research articles evaluating chlorinative stress and the effects of 3-ClTyr on chronic diseases linked to aging. As diseases are not the only source of 3-ClTyr in people, we also focused on other origins of chlorinative stress, such as food intake.

DISCUSSION

Oxidation and halogenation are caused by infectious diseases and by pathologies characterised by inflammation. Moreover, diet could negatively or positively influence chlorinative stress. Comparing 3-ClTyr levels in the oldest and youngest old with age-related diseases and comparing data between different geographic areas with different pesticide rules could be the next challenge.

Dietary supplementation of Macleaya cordata extract and Bacillus in combination improve laying performance by regulating reproductive hormones, intestinal microbiota and barrier function of laying hens

BACKGROUND

This study aimed to investigate whether the combination of Macleaya cordata extract (MCE) and Bacillus could improve the laying performance and health of laying hens better.

METHODS

A total of 360 29-week-old Jingbai laying hens were randomly divided into 4 treatments: control group (basal diet), MCE group (basal diet + MCE), Probiotics Bacillus Compound (PBC) group (basal diet + compound Bacillus), MCE + PBC group (basal diet + MCE + compound Bacillus). The feeding experiment lasted for 42 d.

RESULTS

The results showed that the laying rate and the average daily egg mass in the MCE + PBC group were significantly higher than those in the control group (P < 0.05) and better than the MCE and PBC group. Combination of MCE and Bacillus significantly increased the content of follicle-stimulating hormone (FSH) in the serum and up-regulated the expression of related hormone receptor gene (estrogen receptor-β, FSHR and luteinizing hormone/choriogonadotropin receptor) in the ovary of laying hens (P < 0.05). In the MCE + PBC group, the mRNA expressions of zonula occluden-1, Occludin and mucin-2 in jejunum was increased and the intestinal epithelial barrier detected by transmission electron microscopy was enhanced compared with the control group (P < 0.05). In addition, compared with the control group, combination of MCE and Bacillus significantly increased the total antioxidant capacity and catalase activity (P < 0.05), and down-regulated the mRNA expressions of inflammation-related genes (interleukin-1β and tumor necrosis factor-α) as well as apoptosis-related genes (Caspase 3, Caspase 8 and P53) (P < 0.05). The concentration of acetic acid and butyric acid in the cecum content of laying hens in the MCE + PBC group was significantly increased compared with the control group (P < 0.05).

CONCLUSIONS

Collectively, dietary supplementation of 600 μg/kg MCE and 5 × 108 CFU/kg compound Bacillus can improve laying performance by improving microbiota to enhance antioxidant capacity and intestinal barrier, regulate reproductive hormones and the concentration of cecal short-chain fatty acids of laying hens, and the combined effect of MCE and Bacillus is better than that of single supplementation.

Extracellular traps and the role in thrombosis

Thrombotic complications pose serious health risks worldwide. A significant change in our understanding of the pathophysiology of thrombosis has occurred since the discovery of extracellular traps (ETs) and their prothrombotic properties. As a result of immune cells decondensing chromatin into extracellular fibers, ETs promote thrombus formation by acting as a scaffold that activates platelets and coagulates them. The involvement of ETs in thrombosis has been reported in various thrombotic conditions including deep vein thrombosis (DVT), pulmonary emboli, acute myocardial infarction, aucte ischemic stroke, and abdominal aortic aneurysms. This review summarizes the existing evidence of ETs in human and animal model thrombi. The authors described studies showing the existence of ETs in venous or arterial thrombi. In addition, we studied potential novel therapeutic opportunities related to the resolution or prevention of thrombosis by targeting ETs.

Association between serum 25-hydroxyvitamin d and myeloperoxidase: A cross-sectional study of a general population in China

Background

Several studies have found a strong association between cardiovascular diseases and myeloperoxidase (MPO) as a marker of oxidative stress. Although the anti-inflammatory effects of vitamin D in adults have been validated, evidence about the relationship between MPO and 25(OH)D is lacking. This study aimed to investigate the relationship between MPO and 25(OH)D in the general Chinese population.

Methods

From November 2018 to August 2019, a total of 6414 subjects were enrolled in a tertiary referral hospital in China, which included 3,122 women and 3,292 men. The dependent and independent variables were MPO and 25(OH)D, respectively. The confounders included age, sex, body mass index, waist-hip ratio, smoking status, alcohol drinking status, calcium, and parathyroid hormone concentration.

Results

In the fully adjusted model, we found that MPO decreased by 0.12 (95% CI −0.16, −0.08), ng/mL for each unit (1 nmol/L) increase in 25(OH)D. When 25(OH) D was divided into quartiles, compared with Q1 (< 41.4 nmol/L), the adjusted beta coefficients (β) of MPO in Q2–Q4 were −2.29 (95% CI, −4.31 to −0.27), −4.76 (95% CI, −6.83 to −2.69), and −6.07 (95% CI, −8.23 to −3.92), respectively (P for the trend < 0.0001). When 25(OH) D was divided according to clinical severity, compared with the severely deficient (< 30 nmol/L) s≥ 30, < 50 nmol/L) and sufficient groups (≥ 50 nmol/L) were −2.59 (95% CI, −5.87 to 0.69) and −5.87 (95% CI, −9.17 to −2.57), respectively (P for the trend < 0.0001).

Conclusion

After adjusting for age, sex, BMI, waist-hip ratio, smoking status, alcohol status, calcium, and PTH, circulating 25(OH)D was negatively associated with MPO.

Mitochondrial Dysfunctions and Potential Molecular Markers in Sport Horses

Mitochondria are an essential part of most eukaryotic cells. The crucial role of these organelles is the production of metabolic energy, which is converted into ATP in oxidative phosphorylation. They are also involved in and constitute apoptosis, the site of many metabolic processes. Some of the factors that negatively affect mitochondria are stress, excessive exercise, disease, and the aging process. Exercise can cause the release of large amounts of free radicals, inflammation, injury, and stress. All of these factors can contribute to mitochondrial dysfunction, which can consistently lead to inflammatory responses, tissue damage, organ dysfunction, and a host of diseases. The functions of the mitochondria and the consequences of their disturbance can be of great importance in the breeding and use of horses. The paper reviews mitochondrial disorders in horses and, based on the literature, indicates genetic markers strongly related to this issue.

Oxidative Stress Parameters as Biomarkers of Cardiovascular Disease towards the Development and Progression

Cardiovascular disease (CVD) remains the leading cause of death globally, with unhealthy lifestyles today greatly increasing the risk. Over the decades, scientific investigation has been carried out on reactive oxygen species (ROS) and their resultant oxidative stress based on their changes made on biological targets such as lipids, proteins, and DNA. Since the existing clinical studies with antioxidants failed to provide relevant findings on CVD prediction, the focus has shifted towards recognition of oxidised targets as biomarkers to predict prognosis and response to accurate treatment. The identification of redox markers could help clinicians in providing risk stratification for CVD events beyond the traditional prognostic and diagnostic targets. This review will focus on how oxidant-related parameters can be applied as biomarkers for CVD based on recent clinical evidence.

A signature for pan-cancer prognosis based on neutrophil extracellular traps

BACKGROUND

Neutrophil extracellular traps (NETs) were originally thought to be formed by neutrophils to trap invading microorganisms as a defense mechanism. Increasing studies have shown that NETs play a pivotal role in tumor progression and diffusion. In this case, transcriptome analysis provides an opportunity to unearth the association between NETs and clinical outcomes of patients with pan-cancer.

METHODS

The transcriptome sequencing data of The Cancer Genome Atlas pan-cancer primary focus was obtained from UCSC Xena, and a 19-gene NETs score was then constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression model based on the expression levels of 69 NETs initial biomarkers we collected from multistudies. In addition, multiple datasets covering multiple cancer types from other databases were collected and used to validate the signature. Gene ontology enrichment analyses were used to annotate the functions of NETs-related pathways. Immunohistochemistry (IHC) was implemented to evaluate the role of NETs-related genes in clinical patients across types of tumors, including lung adenocarcinoma (n=58), colorectal carcinoma (n=93), kidney renal clear cell carcinoma (n=90), and triple-negative breast cancer (n=80).

RESULTS

The NETs score was calculated based on 19-NETs related genes according to the LASSO Cox model. The NETs score was considered a hazardous factor in most cancer types, with a higher score indicating a more adverse outcome. In addition, we found that NETs were significantly correlated to various malignant biological processes, such as the epithelial to mesenchymal transition (R=0.7444, p<0.0001), angiogenesis (R=0.5369, p<0.0001), and tumor cell proliferation (R=0.3835, p<0.0001). Furthermore, in IHC cohorts of a variety of tumors, myeloperoxidase, a gene involved in the model and a classical delegate of NETs formation, was associated with poor clinical outcomes.

CONCLUSIONS

Collectively, these constitutive and complementary biomarkers represented the ability of NETs formation to predict the development of patients' progression. Integrative transcriptome analyses plus clinical sample validation may facilitate the biomarker discovery and clinical transformation.

Integrated Gut-Heart Axis and Network Pharmacology to Reveal the Mechanisms of the Huoxue Wentong Formula Against Myocardial Ischemia

Background

Myocardial ischemia (MI) is a major public health problem with high mortality and morbidity worldwide. Huoxue Wentong formula (HX), a traditional Chinese medicine (TCM) formula, exhibits unambiguous effects on treating MI and preventing cardiovascular diseases. However, the molecular mechanism of the therapeutic effects of HX on MI remains largely unknown.

Objective

This study combined microbiology, metabolomics, and network pharmacology to explore the relationship between the gut microbiota and its metabolites in MI rats and the efficacy of HX.

Methods

First, the MI rat model was established by ligation of left anterior descending. Echocardiography, Masson's staining, and hematoxylin and eosin staining were used to evaluate the effect of HX on MI. Then, fecal metabolomics and 16S rRNA sequencing were used to obtain the microbial and metabolic characteristics of HX on MI. After that, network pharmacology was used to predict the target and action pathway of HX in treating MI. Finally, the relationship between fecal metabolites and target was explored through bioinformatics.

Results

HX can improve the cardiac function and ameliorated myocardial fibrosis in MI rats. Moreover, HX can affect the gut microbiota community and metabolites of MI rats, especially Bacteroides, Deferribacteres, Ruminococcus_sp._zagget7, Acidobacteria, daidzein, L-lactic acid, and malate. Network pharmacology found that HX can function through tumor necrosis factor (TNF), tumor protein p53 (TP53), interleukin 6 (IL6), vascular endothelial growth factor A (VEGFA), fos proto-oncogene (FOS), bcl2-associated X (BAX), myeloperoxidase (MPO), PI3K-Akt signaling pathways, and HIF-1 signaling pathway. The mechanism study showed that the anti-MI effect of HX was related to valine, leucine, and isoleucine biosynthesis, fatty acid biosynthesis, and arachidonic acid metabolism.

Conclusion

This study demonstrates that HX treated MI rats in a multitarget and multipathway manner. Its mechanism is related to the change of gut microbiota and the regulation of valine, leucine and isoleucine biosynthesis, fatty acid biosynthesis, and arachidonic acid metabolism.

Targeting the Metabolic-Inflammatory Circuit in Heart Failure With Preserved Ejection Fraction

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) is a leading cause of morbidity and mortality. The current mechanistic paradigm supports a comorbidity-driven systemic proinflammatory state that evokes microvascular and myocardial dysfunction. Crucially, diabetes and obesity are frequently prevalent in HFpEF patients; as such, we review the involvement of a metabolic-inflammatory circuit in disease pathogenesis.

RECENT FINDINGS

Experimental models of diastolic dysfunction and genuine models of HFpEF have facilitated discovery of underlying drivers of HFpEF, where metabolic derangement and systemic inflammation appear to be central components of disease pathophysiology. Despite a shared phenotype among these models, molecular signatures differ depending on type and combination of comorbidities present. Inflammation, oxidative stress, hypertension, and metabolic derangements have been positioned as therapeutic targets to suppress the metabolic-inflammatory circuit in HFpEF. However, the stratification of unique patient phenogroups within the collective HFpEF subgroup argues for specific interventions for distinct phenogroups.

Molecular biomarkers in cardio-oncology: Where we stand and where we are heading

Until recently, cardiotoxicity in the setting of a malignant disease was attributed solely to the detrimental effects of chemo- and/or radio-therapy to the heart. On this account, the focus was on the evaluation of well-established cardiac biomarkers for the early detection of myocardial damage. Currently, this view has been revised. Cardiotoxicity is not restricted to a single organ but instead affects the endothelium as a whole. Indeed, it has come into light that not only cancer therapy but also malignant cells per se can impair the cardiovascular system, through a paracrine and endocrine mode of action. Even more intriguingly, a clear interplay between molecular pathways involved in cancer and cardiovascular disease has become prevalent, suggesting a common nominator that governs the pathophysiology of these two entities. Taken together, our strategy in the quest of novel biomarkers in the emerging field of cardio-oncology should be critically reshaped.

Inhibiting cardiac myeloperoxidase alleviates the relaxation defect in hypertrophic cardiomyocytes

AIMS

Hypertrophic cardiomyopathy (HCM) is characterized by cardiomyocyte hypertrophy and disarray, and myocardial stiffness due to interstitial fibrosis, which result in impaired left ventricular filling and diastolic dysfunction. The latter manifests as exercise intolerance, angina, and dyspnoea. There is currently no specific treatment for improving diastolic function in HCM. Here, we investigated whether myeloperoxidase (MPO) is expressed in cardiomyocytes and provides a novel therapeutic target for alleviating diastolic dysfunction in HCM.

METHODS AND RESULTS

Human cardiomyocytes derived from control-induced pluripotent stem cells (iPSC-CMs) were shown to express MPO, with MPO levels being increased in iPSC-CMs generated from two HCM patients harbouring sarcomeric mutations in the MYBPC3 and MYH7 genes. The presence of cardiomyocyte MPO was associated with higher chlorination and peroxidation activity, increased levels of 3-chlorotyrosine-modified cardiac myosin binding protein-C (MYBPC3), attenuated phosphorylation of MYBPC3 at Ser-282, perturbed calcium signalling, and impaired cardiomyocyte relaxation. Interestingly, treatment with the MPO inhibitor, AZD5904, reduced 3-chlorotyrosine-modified MYBPC3 levels, restored MYBPC3 phosphorylation, and alleviated the calcium signalling and relaxation defects. Finally, we found that MPO protein was expressed in healthy adult murine and human cardiomyocytes, and MPO levels were increased in diseased hearts with left ventricular hypertrophy.

CONCLUSION

This study demonstrates that MPO inhibition alleviates the relaxation defect in hypertrophic iPSC-CMs through MYBPC3 phosphorylation. These findings highlight cardiomyocyte MPO as a novel therapeutic target for improving myocardial relaxation associated with HCM, a treatment strategy which can be readily investigated in the clinical setting, given that MPO inhibitors are already available for clinical testing.

Myeloperoxidase: a new target for the treatment of stroke?

Myeloperoxidase is an important inflammatory factor in the myeloid system, primarily expressed in neutrophils and microglia. Myeloperoxidase and its active products participate in the occurrence and development of hemorrhagic and ischemic stroke, including damage to the blood-brain barrier and brain. As a specific inflammatory marker, myeloperoxidase can be used in the evaluation of vascular disease occurrence and development in stroke, and a large amount of experimental and clinical data has indicated that the inhibition or lack of myeloperoxidase has positive impacts on stroke prognosis. Many studies have also shown that there is a correlation between the overexpression of myeloperoxidase and the risk of stroke. The occurrence of stroke not only refers to the first occurrence but also includes recurrence. Therefore, myeloperoxidase is significant for the clinical evaluation and prognosis of stroke. This paper reviews the potential role played by myeloperoxidase in the development of vascular injury and secondary brain injury after stroke and explores the effects of inhibiting myeloperoxidase on stroke prognosis. This paper also analyzes the significance of myeloperoxidase etiology in the occurrence and development of stroke and discusses whether myeloperoxidase can be used as a target for the treatment and prediction of stroke.

NETs in the infarct-related coronary artery - a marker or mediator of adverse outcome?

No Abstract.

Therapeutic enzymes as non-conventional targets in cardiovascular impairments:A Comprehensive Review

Over the last few decades, substantial progress has been made towards the understanding of cardiovascular diseases (CVDs). In-depth mechanistic insights have also provided opportunities to explore novel therapeutic targets and treatment regimens to be discovered. Therapeutic enzymes are an example of such opportunities. The balanced functioning of such enzymes protects against a variety of CVDs while on the other hand, even a small shift in the normal functioning of these enzymes may lead to deleterious outcomes. Owing to the great versatility of these enzymes, inhibition and activation are key regulatory approaches to counter the onset and progression of several cardiovascular impairments. While cardiovascular remedies are already available in excess and of course they are efficacious, a comprehensive description of novel therapeutic enzymes to combat CVDs is the need of the hour. In light of this, the regulation of the functional activity of these enzymes also opens a new avenue for the treatment approaches to be employed. This review describes the importance of non-conventional enzymes as potential candidates in several cardiovascular disorders while highlighting some of the recently targeted therapeutic enzymes in CVDs.

Neutrophil Pathways of Inflammation Characterize the Blood Transcriptomic Signature of Patients with Psoriasis and Cardiovascular Disease

BACKGROUND

Patients with psoriasis have an increased risk of atherosclerotic cardiovascular disease (CVD). The molecular mechanisms behind this connection are not fully understood, but the involvement of neutrophils have drawn attention as a shared inflammatory factor.

METHODS

RNA sequencing using the Illumina platform was performed on blood from 38 patients with moderate to severe psoriasis; approximately half had prior CVD. The neutrophil to lymphocyte ratio (NLR) was obtained from blood samples. Subclinical atherosclerosis was assessed by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography and ultrasound imaging. Transcriptomic analysis for differential expression and functional enrichment were performed, followed by correlation analyses of differentially expressed genes (DEGs), NLR and subclinical measurers of CVD.

RESULTS

291 genes were differentially expressed between patients with psoriasis with and without CVD. These included 208 upregulated and 83 downregulated DEGs. Neutrophil degranulation was identified as the most significant process related to the upregulated DEGs. Genes for the neutrophil-associated markers MPO, MMP9, LCN2, CEACAM1, CEACAM6 and CEACAM8 were identified as being of special interest and their mRNA levels correlated with NLR, high-sensitive C-reactive protein and markers of subclinical CVD.

CONCLUSIONS

Patients with psoriasis and CVD had an increased expression of genes related to neutrophil degranulation in their blood transcriptome compared with patients with psoriasis without CVD. NLR may be a potential biomarker of subclinical CVD in psoriasis.

The aggravation of allergic airway inflammation with dibutyl phthalate involved in Nrf2-mediated activation of the mast cells

Dibutyl phthalate (DBP)-an organic pollutant-is ubiquitous in the environment. DBP as an immune adjuvant is related to the development of multiple allergic diseases. However, the current research involving DBP-induced pulmonary toxicity remains poorly understood. Therefore, this research aimed to explore the adverse effect and potential mechanism of DBP exposure on the lungs in rats. In our study, ovalbumin was used to build a rat model of allergic airway inflammation to study any harmful effect of DBP exposure on lung tissues. Rats were treated by intragastric administration of DBP (500 mg kg^-1 or 750 mg kg^-1) and/or subcutaneous injection of SFN (4 mg kg^-1). The results of histopathological analysis, cell count, and myeloperoxidase showed that DBP promoted the inflammatory damage of lungs. In the lung tissues, the detection of terminal deoxynucleotidyl transferase dUNT nick end labeling and oxidative stress indices showed that DBP significantly increased the level of apoptosis and oxidative stress. Western blot analysis indicated that DBP raised the expression level of thymic stromal lymphopoietin and reduced the nuclear expression level of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was further verified by quantitative real-time PCR. Meanwhile, DBP treatment markedly up-regulated the inflammatory cytokines such as IL-4 and IL-13, and rat mast cell protease-2, a marker secreted by mast cells (MCs). Conversely, sulforaphane, a Nrf2 inducer, ameliorated the pulmonary damage induced by DBP in the above. Altogether, our data provides a new insight into the impacts of the activation of MCs on the DBP-induced pulmonary toxicity as well as the safety evaluation of DBP.

The many roles of myeloperoxidase: From inflammation and immunity to biomarkers, drug metabolism and drug discovery

This review provides a practical guide to myeloperoxidase (MPO) and presents to the reader the diversity of its presence in biology. The review provides a historical background, from peroxidase activity to the discovery of MPO, to its role in disease and drug development. MPO is discussed in terms of its necessity, as specific individuals lack MPO expression. An underlying theme presented throughout brings up the question of the benefit and burden of MPO activity. Enzyme structure is discussed, including accurate masses and glycosylation sites. The catalytic cycle of MPO and its corresponding pathways are presented, with a discussion of the importance of the redox couples of the different states of MPO. Cell lines expressing MPO are discussed and practically summarized for the reader, and locations of MPO (primary and secondary) are provided. Useful methods of MPO detection are discussed, and how these can be used for studying disease processes are implied through the presentation of MPO as a biomarker. The presence of MPO in neutrophil extracellular traps is presented, and the activators of the former are provided. Lastly, the transition from drug metabolism to a target for drug development is where the review concludes.

Growth Arrest-Specific Gene 6 Administration Ameliorates Sepsis-Induced Organ Damage in Mice and Reduces ROS Formation In Vitro

Sepsis is a widespread life-threatening disease, with a high mortality rate due to inflammation-induced multiorgan failure (MOF). Thus, new effective modulators of the immune response are urgently needed to ameliorate the outcome of septic patients. As growth arrest-specific gene 6 (Gas6)/Tyro3, Axl, MerTK (TAM) receptors signaling has shown immunomodulatory activity in sepsis, here we sought to determine whether Gas6 protein injection could mitigate MOF in a cecal slurry mouse model of sepsis. Mice, divided into different groups according to treatment-i.e., placebo (B), ampicillin (BA), Gas6 alone (BG), and ampicillin plus Gas6 (BAG)-were assessed for vitality, histopathology and cytokine expression profile as well as inducible nitric oxide synthase (iNOS), ALT and LDH levels. BAG-treated mice displayed milder kidney and lung damage and reduced levels of cytokine expression and iNOS in the lungs compared to BA-treated mice. Notably, BAG-treated mice showed lower LDH levels compared to controls. Lastly, BAG-treated cells of dendritic, endothelial or monocytic origin displayed reduced ROS formation and increased cell viability, with a marked upregulation of mitochondrial activity. Altogether, our findings indicate that combined treatment with Gas6 and antibiotics ameliorates sepsis-induced organ damage and reduces systemic LDH levels in mice, suggesting that Gas6 intravenous injection may be a viable therapeutic option in sepsis.

Diabetes and Its Complications: Therapies Available, Anticipated and Aspired

Worldwide, diabetes ranks among the ten leading causes of mortality. Prevalence of diabetes is growing rapidly in low and middle income countries. It is a progressive disease leading to serious co-morbidities, which results in increased cost of treatment and over-all health system of the country. Pathophysiological alterations in Type 2 Diabetes (T2D) progressed from a simple disturbance in the functioning of the pancreas to triumvirate to ominous octet to egregious eleven to dirty dozen model. Due to complex interplay of multiple hormones in T2D, there may be multifaceted approach in its management. The 'long-term secondary complications' in uncontrolled diabetes may affect almost every organ of the body, and finally may lead to multi-organ dysfunction. Available therapies are inconsistent in maintaining long term glycemic control and their long term use may be associated with adverse effects. There is need for newer drugs, not only for glycemic control but also for prevention or mitigation of secondary microvascular and macrovascular complications. Increased knowledge of the pathophysiology of diabetes has contributed to the development of novel treatments. Several new agents like Glucagon Like Peptide - 1 (GLP-1) agonists, Dipeptidyl Peptidase IV (DPP-4) inhibitors, amylin analogues, Sodium-Glucose transport -2 (SGLT- 2) inhibitors and dual Peroxisome Proliferator-Activated Receptor (PPAR) agonists are available or will be available soon, thus extending the range of therapy for T2D, thereby preventing its long term complications. The article discusses the pathophysiology of diabetes along with its comorbidities, with a focus on existing and novel upcoming antidiabetic drugs which are under investigation. It also dives deep to deliberate upon the novel therapies that are in various stages of development. Adding new options with new mechanisms of action to the treatment armamentarium of diabetes may eventually help improve outcomes and reduce its economic burden.