Cardioprotective and antiapoptotic effects of heme oxygenase-1 in the failing heart

Fucoidan alleviates doxorubicin-induced cardiotoxicity by inhibiting ferroptosis via Nrf2/GPX4 pathway

Doxorubicin (Dox), a chemotherapeutic agent frequently used to treat cancer, elicits cardiotoxicity, a condition referred to as Dox-induced cardiotoxicity (DIC), and ferroptosis plays a contributory role in its pathophysiology. Fucoidan, a polysaccharide with various biological activities and safety profile, has potential therapeutic and pharmaceutical applications. This study aimed to investigate the protective effects and underlying mechanisms of fucoidan in DIC. Echocardiography, biomarkers of cardiomyocyte injury, serum creatine kinase, creatine kinase isoenzyme and lactate dehydrogenase, as well as histological staining results, revealed that fucoidan significantly reduced myocardial damage and improved cardiac function in DIC mice. Transmission electron microscopy; levels of lipid reactive oxygen species, glutathione, and malondialdehyde; ferroptosis-related markers; and regulatory factors such as glutathione peroxidase 4 (GPX4), transferrin receptor protein-1, ferritin heavy chain-1, heme oxygenase-1 in the heart tissue were measured to explore the effect of fucoidan on Dox-induced ferroptosis. These results suggested that fucoidan could inhibit cardiomyocyte ferroptosis caused by Dox. In vitro experiments revealed that silencing nuclear factor-erythroid 2-related factor 2 (Nrf2) in cardiomyocytes reduced the inhibitory effect of fucoidan on ferroptosis. Hence, fucoidan has the potential to ameliorate DIC by inhibiting ferroptosis via the Nrf2/GPX4 pathway.

Heme Oxygenase-1, Cardiac Senescence, and Myocardial Infarction: A Critical Review of the Triptych

PURPOSE

Heme oxygenase-1 (HO-1) is a crucial enzyme in heme metabolism, facilitating the breakdown of heme into biliverdin, carbon monoxide, and free iron. Renowned for its potent cytoprotective properties, HO-1 showcases notable antioxidant, anti-inflammatory, and anti-apoptotic effects. In this review, the authors aim to explore the profound impact of HO-1 on cardiac senescence and its potential implications in myocardial infarction (MI).

RESULTS

Recent research has unveiled the intricate role of HO-1 in cellular senescence, characterized by irreversible growth arrest and functional decline. Notably, cardiac senescence has emerged as a pivotal factor in the development of various cardiovascular conditions, including MI. Notably, cardiac senescence has emerged as an important factor in the development of various cardiovascular conditions, including myocardial infarction (MI). The accumulation of senescent cells, spanning vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes, and progenitor cells, poses a significant risk for cardiovascular diseases such as vascular aging, atherosclerosis, myocardial infarction, and ventricular remodeling. Inhibition of cardiomyocyte senescence not only reduces senescence-associated inflammation but also impacts other myocardial lineages, hinting at a broader mechanism of propagation in pathological remodeling. HO-1 has been shown to improve heart function and mitigate cardiomyocyte senescence induced by ischemic injury and aging. Furthermore, HO-1 induction has been found to alleviate H2O2-induced cardiomyocyte senescence. As we grow in our understanding of antiproliferative, antiangiogenic, anti-aging, and vascular effects of HO-1, we see the potential to exploit potential links between individual susceptibility to cardiac senescence and myocardial infarction.

CONCLUSIONS

This review investigates strategies for upregulating HO-1, including gene targeting and pharmacological agents, as potential therapeutic approaches. By synthesizing compelling evidence from diverse experimental models and clinical investigations, this study elucidates the therapeutic potential of targeting HO-1 as an innovative strategy to mitigate cardiac senescence and improve outcomes in myocardial infarction, emphasizing the need for further research in this field.

Metal-based carbon monoxide releasing molecules with promising cytotoxic properties

Carbon monoxide, the "silent killer" gas, is increasingly recognised as an important signalling molecule in human physiology, which has beneficial biological properties. A particular way of achieving controlled CO administration is based on the use of biocompatible molecules that only release CO when triggered by internal or external factors. These approaches include the development of pharmacologically effective prodrugs known as CO releasing molecules (CORMs), which can supply biological systems with CO in well-regulated doses. An overview of transition metal-based CORMs with cytotoxic properties is here reported. The mechanisms at the basis of the biological activities of these molecules and their potential therapeutical applications with respect to their stability and CO releasing properties have been discussed. The activation of metal-based CORMs is determined by the type of metal and by the nature and features of the auxiliary ligands, which affect the metal core electronic density and therefore the prodrug resistance towards oxidation and CO release ability. A major role in regulating the cytotoxic properties of these CORMs is played by CO and/or CO-depleted species. However, several mysteries concerning the cytotoxicity of CORMs remain as intriguing questions for scientists.

Mitochondrial dynamics dysfunction: Unraveling the hidden link to depression

Depression is a common mental disorder and its pathogenesis is not fully understood. However, more and more evidence shows that mitochondrial dynamics dysfunction may play an important role in the occurrence and development of depression. Mitochondria are the centre of energy production in cells, and are also involved in important processes such as apoptosis and oxidative stress. Studies have found that there are abnormalities in mitochondrial function in patients with depression, including mitochondrial morphological changes, mitochondrial dynamics disorders, mitochondrial DNA damage, and impaired mitochondrial respiratory chain function. These abnormalities may cause excessive free radicals and oxidative stress in mitochondria, which further damage cells and affect the balance of neurotransmitters, causing or aggravating depressive symptoms. Studies have shown that mitochondrial dynamics dysfunction may participate in the occurrence and development of depression by affecting neuroplasticity, inflammation and neurotransmitters. This article reviews the effects of mitochondrial dynamics dysfunction on the pathogenesis of depression and its potential molecular pathway. The restorers for the treatment of depression by regulating the function of mitochondrial dynamics were summarized and the possibility of using mitochondrial dynamics as a biomarker of depression was discussed.

Recent advances in the application of gasotransmitters in spinal cord injury

Spinal Cord Injury (SCI) is a condition characterized by complete or incomplete motor and sensory impairment, as well as dysfunction of the autonomic nervous system, caused by factors such as trauma, tumors, or inflammation. Current treatment methods primarily include traditional approaches like spinal canal decompression and internal fixation surgery, steroid pulse therapy, as well as newer techniques such as stem cell transplantation and brain-spinal cord interfaces. However, the above methods have limited efficacy in promoting axonal and neuronal regeneration. The challenge in medical research today lies in promoting spinal cord neuron regeneration and regulating the disrupted microenvironment of the spinal cord. Studies have shown that gas molecular therapy is increasingly used in medical research, with gasotransmitters such as hydrogen sulfide, nitric oxide, carbon monoxide, oxygen, and hydrogen exhibiting neuroprotective effects in central nervous system diseases. The gas molecular protect against neuronal death and reshape the microenvironment of spinal cord injuries by regulating oxidative, inflammatory and apoptotic processes. At present, gas therapy mainly relies on inhalation for systemic administration, which cannot effectively enrich and release gas in the spinal cord injury area, making it difficult to achieve the expected effects. With the rapid development of nanotechnology, the use of nanocarriers to achieve targeted enrichment and precise control release of gas at Sites of injury has become one of the emerging research directions in SCI. It has shown promising therapeutic effects in preclinical studies and is expected to bring new hope and opportunities for the treatment of SCI. In this review, we will briefly outline the therapeutic effects and research progress of gasotransmitters and nanogas in the treatment of SCI.

Neutrophils are indispensable for adverse cardiac remodeling in heart failure

Persistent immune activation contributes significantly to left ventricular (LV) dysfunction and adverse remodeling in heart failure (HF). In contrast to their well-known essential role in acute myocardial infarction (MI) as first responders that clear dead cells and facilitate subsequent reparative macrophage polarization, the role of neutrophils in the pathobiology of chronic ischemic HF is poorly defined. To determine the importance of neutrophils in the progression of ischemic cardiomyopathy, we measured their production, levels, and activation in a mouse model of chronic HF 8 weeks after permanent coronary artery ligation and large MI. In HF mice, neutrophils were more abundant both locally in failing myocardium (more in the border zone) and systemically in the blood, spleen, and bone marrow, together with increased BM granulopoiesis. There were heightened stimuli for neutrophil recruitment and trafficking in HF, with increased myocardial expression of the neutrophil chemoattract chemokines CXCL1 and CXCL5, and increased neutrophil chemotactic factors in the circulation. HF neutrophil NETotic activity was increased in vitro with coordinate increases in circulating neutrophil extracellular traps (NETs) in vivo. Neutrophil depletion with either antibody-based or genetic approaches abrogated the progression of LV remodeling and fibrosis at both intermediate and late stages of HF. Moreover, analogous to murine HF, the plasma milieu in human acute decompensated HF strongly promoted neutrophil trafficking. Collectively, these results support a key tissue-injurious role for neutrophils and their associated cytotoxic products in ischemic cardiomyopathy and suggest that neutrophils are potential targets for therapeutic immunomodulation in this disease.

Deficiency of heme oxygenase 1a causes detrimental effects on cardiac function

Humans lacking heme oxygenase 1 (HMOX1) display growth retardation, haemolytic anaemia, and vulnerability to stress; however, cardiac function remains unclear. We aimed to explore the cardiac function of zebrafish lacking hmox1a at baseline and in response to stress. We generated zebrafish hmox1a mutants using CRISPR/Cas9 genome editing technology. Deletion of hmox1a increases cardiac output and further induces hypertrophy in adults. Adults lacking hmox1a develop myocardial interstitial fibrosis, restrain cardiomyocyte proliferation and downregulate renal haemoglobin and cardiac antioxidative genes. Larvae lacking hmox1a fail to respond to hypoxia, whereas adults are insensitive to isoproterenol stimulation in the heart, suggesting that hmox1a is necessary for cardiac response to stress. Haplodeficiency of hmox1a stimulates non-mitochondrial respiration and cardiac cell proliferation, increases cardiac output in larvae in response to hypoxia, and deteriorates cardiac function and structure in adults upon isoproterenol treatment. Intriguingly, haplodeficiency of hmox1a upregulates cardiac hmox1a and hmox1b in response to isoproterenol. Collectively, deletion of hmox1a results in cardiac remodelling and abrogates cardiac response to hypoxia and isoproterenol. Haplodeficiency of hmox1a aggravates cardiac response to the stress, which could be associated with the upregulation of hmox1a and hmox1b. Our data suggests that HMOX1 homeostasis is essential for maintaining cardiac function and promoting cardioprotective effects.

Synthetic biology approach revealed enhancement in haeme oxygenase-1 gene expression by codon pair optimization while reduction by codon deoptimization

Haem oxygenase-1 (HO-1) is a ubiquitously expressed gene involved in cellular homoeostasis, and its imbalance in expression results in various disorders. To alleviate such disorders, HO-1 gene expression needs to be modulated. Codon usage bias results from evolutionary forces acting on any nucleotide sequence and determines the gene expression. Like codon usage bias, codon pair bias also exists, playing a role in gene expression. In the present study, HO-1 gene was recoded by manipulating codon and codon pair bias, and four such constructs were made through codon/codon pair deoptimization and codon/codon pair optimization to reduce and enhance the HO-1 gene expression. Codon usage analysis was done for these constructs for four tissues brain, heart, pancreas and liver. Based on codon usage in different tissues, gene expression of these tissues was determined in terms of the codon adaptation index. Based on the codon adaptation index, minimum free energy, and translation efficiency, constructs were evaluated for enhanced or decreased HO-1 expression. The analysis revealed that for enhancing gene expression, codon pair optimization, while for reducing gene expression, codon deoptimization is efficacious. The recoded constructs developed in the study could be used in gene therapy regimens to cure HO-1 over or underexpression-associated disorders.

Identification of immune-associated genes in vascular dementia by integrated bioinformatics and inflammatory infiltrates

Objective

Dysregulation of the immune system plays a vital role in the pathological process of vascular dementia, and this study aims to spot critical biomarkers and immune infiltrations in vascular dementia employing a bioinformatics approach.

Methods

We acquired gene expression profiles from the Gene Expression Database. The gene expression data were analyzed using the bioinformatics method to identify candidate immune-related central genes for the diagnosis of vascular dementia. and the diagnostic value of nomograms and Receiver Operating Characteristic (ROC) curves were evaluated. We also examined the role of the VaD hub genes. Using the database and potential therapeutic drugs, we predicted the miRNA and lncRNA controlling the Hub genes. Immune cell infiltration was initiated to examine immune cell dysregulation in vascular dementia.

Results

1321 immune genes were included in the combined immune dataset, and 2816 DEGs were examined in GSE122063. Twenty potential genes were found using differential gene analysis and co-expression network analysis. PPI network design and functional enrichment analysis were also done using the immune system as the main subject. To create the nomogram for evaluating the diagnostic value, four potential core genes were chosen by machine learning. All four putative center genes and nomograms have a solid diagnostic value (AUC ranged from 0.81 to 0.92). Their high confidence level became unquestionable by validating each of the four biomarkers using a different dataset. According to GeneMANIA and GSEA enrichment investigations, the pathophysiology of VaD is strongly related to inflammatory responses, drug reactions, and central nervous system degeneration. The data and Hub genes were used to construct a ceRNA network that includes three miRNAs, 90 lncRNA, and potential VaD therapeutics. Immune cells with varying dysregulation were also found.

Conclusion

Using bioinformatic techniques, our research identified four immune-related candidate core genes (HMOX1, EBI3, CYBB, and CCR5). Our study confirms the role of these Hub genes in the onset and progression of VaD at the level of immune infiltration. It predicts potential RNA regulatory pathways control VaD progression, which may provide ideas for treating clinical disease.

Serum apolipoprotein B to apolipoprotein A-I ratio predicts mortality in patients with heart failure

AIMS

Apolipoproteins have been reported to be involved in many cardiovascular diseases. The aim of our study was to investigate the prognostic value of apolipoprotein B (ApoB) to apolipoprotein A-I (ApoA-I) ratio (ApoB/ApoA-I) in patients with heart failure (HF).

METHODS AND RESULTS

We randomly assigned 2400 HF patients into the training cohort (n = 1400) and the validation cohort (n = 1000). Using a receiver operating characteristic curve, we identified the optimal cut-off value of the ApoB/ApoA-I in the training cohort as 0.69, which was further validated in the validation cohort. A propensity score matching (PSM) analysis was conducted to eliminate the imbalance in the baseline characteristics of the high and low ApoB/ApoA-I group. A total of 2242 HF patients were generated in the PSM cohort. We also validated our results with an independent cohort (n = 838). Univariate and multivariate analyses were conducted to explore the independent prognostic value of ApoB/ApoA-I in the training cohort (n = 1400), the validation cohort (n = 1000), the PSM cohort (n = 2242), and the independent cohort (n = 838). Patients with high ApoB/ApoA-I ratio had significantly poorer prognosis compared with those with low ApoB/ApoA-I ratio in the training cohort, the validation cohort, the PSM cohort, and the independent cohort (P < 0.05). Multivariate analysis indicated that the ApoB/ApoA-I was an independent prognostic factor for HF in the training cohort [hazard ratio (HR) = 1.637, 95% confidence interval (CI) = 1.201-2.231, P = 0.002], the validation cohort (HR = 1.54, 95% CI = 1.051-2.257, P = 0.027), the PSM cohort (HR = 1.645, 95% CI = 1.273-2.125, P < 0.001), and the independent cohort (HR = 1.987, 95% CI = 1.251-3.155, P = 0.004).

CONCLUSIONS

Serum ApoB/ApoA-I ratio is an independent predictor for the prognosis of HF patients.

Ferroptosis contributes to catecholamine-induced cardiotoxicity and pathological remodeling

High levels of circulating catecholamines cause cardiac injury, pathological remodeling, and heart failure, but the underlying mechanisms remain elusive. Here we provide both in vitro and in vivo evidence that excessive β-adrenergic stimulation induces ferroptosis in cardiomyocytes, revealing a novel mechanism for catecholamine-induced cardiotoxicity and remodeling. We found that isoproterenol, a synthetic catecholamine, promoted glutathione depletion and glutathione peroxidase 4 (GPX4) degradation in cardiomyocytes, leading to GPX4 inactivation and enhanced lipid peroxidation. Isoproterenol also promoted heme oxygenase 1 (HO-1) expression by downregulating the transcription suppressor BTB and CNC homology 1 (Bach1), leading to increased labile iron accumulation through heme degradation. Moreover, isoproterenol markedly induced the accumulation of free iron and lipid reactive oxygen species (ROS) in the mitochondria, while targeted inhibition of iron overload and ROS accumulation within mitochondria effectively inhibited ferroptosis in cardiomyocytes. Importantly, isoproterenol administration markedly induced ferroptosis in the myocardium in vivo, associated with elevated non-heme iron accumulation driven by HO-1 upregulation. Strikingly, blockade of ferroptosis with ferrostatin-1 or inhibition of HO-1 activity with zinc protoporphyrin (ZnPP) effectively alleviated cardiac necrosis, pathological remodeling, and heart failure induced by isoproterenol administration. Taken together, our results reveal that catecholamine stimulation primarily induces ferroptotic cell death in cardiomyocyte through GPX4 and Bach1-HO-1 dependent signaling pathways. Targeting ferroptosis may represent a novel therapeutic strategy for catecholamine overload-induced myocardial injury and heart failure.

An ischemic area-targeting, peroxynitrite-responsive, biomimetic carbon monoxide nanogenerator for preventing myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (MI/R) injury is common in patients who undergo revascularization therapy for myocardial infarction, often leading to cardiac dysfunction. Carbon monoxide (CO) has emerged as a therapeutic molecule due to its beneficial properties such as anti-inflammatory, anti-apoptotic, and mitochondrial biogenesis-promoting properties. However, its clinical application is limited due to uncontrolled release, potential toxicity, and poor targeting efficiency. To address these limitations, a peroxynitrite (ONOO^-)-triggered CO donor (PCOD585) is utilized to generate a poly (lactic-co-glycolic acid) (PLGA)-based, biomimetic CO nanogenerator (M/PCOD@PLGA) that is coated with the macrophage membrane, which could target to the ischemic area and neutralize proinflammatory cytokines. In the ischemic area, local produced ONOO^- triggers the continuous release of CO from M/PCOD@PLGA, which efficiently ameliorates MI/R injury by clearing harmful ONOO^-, attenuating the inflammatory response, inhibiting cardiomyocyte apoptosis, and promoting mitochondrial biogenesis. This study provides a novel insight into the safe therapeutic use of CO for MI/R injury by utilizing a novel CO donor combined with biomimetic technology. The M/PCOD@PLGA nanogenerator offers targeted delivery of CO to the ischemic area, minimizing potential toxicity and enhancing therapeutic efficacy.

Oxidative stress induces mitochondrial iron overload and ferroptotic cell death

Oxidative stress has been shown to induce cell death in a wide range of human diseases including cardiac ischemia/reperfusion injury, drug induced cardiotoxicity, and heart failure. However, the mechanism of cell death induced by oxidative stress remains incompletely understood. Here we provide new evidence that oxidative stress primarily induces ferroptosis, but not apoptosis, necroptosis, or mitochondria-mediated necrosis, in cardiomyocytes. Intriguingly, oxidative stress induced by organic oxidants such as tert-butyl hydroperoxide (tBHP) and cumene hydroperoxide (CHP), but not hydrogen peroxide (H2O2), promoted glutathione depletion and glutathione peroxidase 4 (GPX4) degradation in cardiomyocytes, leading to increased lipid peroxidation. Moreover, elevated oxidative stress is also linked to labile iron overload through downregulation of the transcription suppressor BTB and CNC homology 1 (Bach1), upregulation of heme oxygenase 1 (HO-1) expression, and enhanced iron release via heme degradation. Strikingly, oxidative stress also promoted HO-1 translocation to mitochondria, leading to mitochondrial iron overload and lipid reactive oxygen species (ROS) accumulation. Targeted inhibition of mitochondrial iron overload or ROS accumulation, by overexpressing mitochondrial ferritin (FTMT) or mitochondrial catalase (mCAT), respectively, markedly inhibited oxidative stress-induced ferroptosis. The levels of mitochondrial iron and lipid peroxides were also markedly increased in cardiomyocytes subjected to simulated ischemia and reperfusion (sI/R) or the chemotherapeutic agent doxorubicin (DOX). Overexpressing FTMT or mCAT effectively prevented cardiomyocyte death induced by sI/R or DOX. Taken together, oxidative stress induced by organic oxidants but not H2O2 primarily triggers ferroptotic cell death in cardiomyocyte through GPX4 and Bach1/HO-1 dependent mechanisms. Our results also reveal mitochondrial iron overload via HO-1 mitochondrial translocation as a key mechanism as well as a potential molecular target for oxidative stress-induced ferroptosis in cardiomyocytes.

Identification of two novel ferroptosis-associated targets in sepsis-induced cardiac injury: Hmox1 and Slc7a11

Purpose

Sepsis-induced cardiac injury is a severe complication of sepsis and has a high mortality. Recent research has implicated ferroptosis as a contributing factor to myocardial cell death. This study is aimed at finding novel ferroptosis-associated targets in sepsis-induced cardiac injury.

Methods and results

In our study, a total of two Gene expression omnibus datasets (GSE185754 and GSE171546) were obtained for bioinformatics analysis. GSEA enrichment analysis demonstrated that ferroptosis pathway Z-score rapidly increased in the first 24 h and decreased gradually in the following 24-72 h. Fuzzy analysis was then used to obtain distinct clusters of temporal patterns and find genes in cluster 4 that exhibited the same trend with ferroptosis progression during the time points. After intersecting the differentially expressed genes, genes in cluster 4, and ferroptosis-related genes, three ferroptosis-associated targets were finally selected: Ptgs2, Hmox1, and Slc7a11. While Ptgs2 has been previously reported to be involved in the regulation of septic cardiomyopathy, this study is the first to demonstrate that downregulation of Hmox1 and Slc7a11 can alleviate ferroptosis in sepsis-induced cardiac injury.

Conclusion

This study reports Hmox1 and Slc7a11 as ferroptosis-associated targets in sepsis-induced cardiac injury, and both of them may become key therapeutic and diagnostic targets for this complication in the future.

Tingli Dazao Decoction pretreatment ameliorates mitochondrial damage induced by oxidative stress in cardiomyocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Tingli Dazao Decoction (TLDZD) recorded in "Synopsis of Prescriptions of the Golden Chamber" is a classical prescription used for the treatment of heart failure nowadays. The studies of TLDZD were mainly focused on clinical practice where the formula was usually combined with other medicinal herbs. Chemical composition and cardiovascular pharmacological research of TLDZD were still insufficient.

AIM OF THE STUDY

This study aimed to investigate the chemical constituents of TLDZD, evaluate the effects of TLDZD on mitochondria of myocardial cells under oxidative stress, and identify its potential cardioprotective components.

MATERIALS AND METHODS

Chemical composition analysis of TLDZD was performed by ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry. An in vitro oxidative stress model of cardiomyocytes was established by treating H9c2 cells with tert-butyl hydroperoxide (tBHP). The impact of TLDZD and its components on the production of cellular reactive oxygen species (ROS) and mitochondrial ROS (mROS), the level of malonaldehyde as well as the structure and function of mitochondria were evaluated. The effect of TLDZD on AKT/Nrf2/HO-1 signaling pathway in cardiomyocytes under oxidative stress were observed.

RESULTS

Seventy-eight compounds were characterized from TLDZD, among which flavonoids, glucosinolates and phenylpropanoids were abundant, and a small number of cardiac glycosides and alkaloids also existed in TLDZD. Pretreatment with TLDZD significantly attenuated cell death, accompanied by decreased ROS and mROS production, reduced malonaldehyde level, lower mitochondrial membrane potential and adenosine triphosphate content in H9c2 cells stimulated with tBHP. The active components were mainly flavonoids of TLZ represented by quercetin-3-O-β-D-glucose-7-O-β-D-gentiobioside. In mechanism, the cardioprotective effect of TLDZD was proved to be associated with the activation of the AKT/Nrf2/HO-1 signaling pathway.

CONCLUSIONS

The chemical profile of TLDZD was comprehensively investigated. Flavonoids with quercetin-3-O-β-D-glucose-7-O-β-D-gentiobioside as the representative, were the main component in TLDZD responsible for attenuating mitochondrial oxidative damage in cardiomyocytes.

Celastrol: The new dawn in the treatment of vascular remodeling diseases

Evidence is mounting that abnormal vascular remodeling leads to many cardiovascular diseases (CVDs). This suggests that vascular remodeling can be a crucial target for the prevention and treatment of CVDs. Recently, celastrol, an active ingredient of the broadly used Chinese herb Tripterygium wilfordii Hook F, has attracted extensive interest for its proven potential to improve vascular remodeling. Substantial evidence has shown that celastrol improves vascular remodeling by ameliorating inflammation, hyperproliferation, and migration of vascular smooth muscle cells, vascular calcification, endothelial dysfunction, extracellular matrix remodeling, and angiogenesis. Moreover, numerous reports have proven the positive effects of celastrol and its therapeutic promise in treating vascular remodeling diseases such as hypertension, atherosclerosis, and pulmonary artery hypertension. The present review summarizes and discusses the molecular mechanism of celastrol regulating vascular remodeling and provides preclinical proof for future clinical applications of celastrol.

Qili Qiangxin capsules for chronic heart failure: A GRADE-assessed clinical evidence and preclinical mechanism

Introduction

Chronic heart failure (CHF) has become an increasing concern with the aging of the population. This study aims to evaluate the effectiveness and safety of Qili Qiangxin capsules (QLQX) for CHF.

Methods

A systematic review and meta-analysis on clinical studies was conducted. The mechanisms of preclinical studies were summarized.

Results

We searched six electronic databases by 20 July 2022, and finally, 7 preclinical experiments (PEs) and 24 randomized controlled trials were included. The risk of bias was accessed by the SYRCLE and RoB 2.0 tool, respectively. PEs indicated that QLQX suppresses myocardial apoptosis, inhibits renin-angiotensin-aldosterone system activation, improves water retention, and enhances cardiocyte remodeling. In clinical studies, compared with routine treatment, QLQX could improve the indicators: clinical efficacy rate (RR = 1.16, 95% CI [1.12, 1.22], GRADE: moderate), left ventricular end-diastolic dimension (SMD = -1.04, 95% CI [-1.39, -0.70], GRADE: low), left ventricular ejection fraction (SMD = 1.20, 95% CI [0.97, 1.43], GRADE: moderate), 6-minute walk distance (SMD = 1.55, 95% CI [0.89, 2.21], GRADE: low), brain natriuretic peptide (SMD = -0.78, 95% CI [-1.06, -0.51], GRADE: low), N-terminal pro-brain natriuretic peptide (SMD = -2.15, 95% CI [-3.60, -0.71], GRADE: low), and adverse events (RR = 0.46, 95% CI [0.25, 0.87], GRADE: low).

Discussion

In summary, QLQX exerts a potential mechanism of utility on myocardial apoptosis and cardiac function and has noteworthy clinical adjuvant efficacy and safety in patients with CHF.

Systematic review registration

https://www.crd.york.ac.uk/prospero/.

A Comprehensive Review of Dilated Cardiomyopathy in Pre-clinical Animal Models in Addition to Herbal Treatment Options and Multi-modality Imaging Strategies

Dilated cardiomyopathy (DCM) is distinguished by ventricular chamber expansion, systolic dysfunction, and normal left ventricular (LV) wall thickness, and is mainly caused due to genetic or environmental factors; however, its aetiology is undetermined in the majority of patients. The focus of this work is on pathogenesis, small animal models, as well as the herbal medicinal approach, and the most recent advances in imaging modalities for patients with dilated cardiomyopathy. Several small animal models have been proposed over the last few years to mimic various pathomechanisms that contribute to dilated cardiomyopathy. Surgical procedures, gene mutations, and drug therapies are all characteristic features of these models. The pros and cons, including heart failure stimulation of extensively established small animal models for dilated cardiomyopathy, are illustrated, as these models tend to procure key insights and contribute to the development of innovative treatment techniques for patients. Traditional medicinal plants used as treatment in these models are also discussed, along with contemporary developments in herbal therapies. In the last few decades, accurate diagnosis, proper recognition of the underlying disease, specific risk stratification, and forecasting of clinical outcome, have indeed improved the health of DCM patients. Cardiac magnetic resonance (CMR) is the bullion criterion for assessing ventricular volume and ejection fraction in a reliable and consistent direction. Other technologies, like strain analysis and 3D echocardiography, have enhanced this technique's predictive and therapeutic potential. Nuclear imaging potentially helps doctors pinpoint the causative factors of left ventricular dysfunction, as with cardiac sarcoidosis and amyloidosis.

Zn and Se abrogate heavy metal mixture induced ovarian and thyroid oxido-inflammatory effects mediated by activation of NRF2-HMOX-1 in female albino rats

The thyroid is vital for the proper functioning of the female reproductive system since it regulates the metabolism and development of ovary. This is an evaluation of the essential trace elements ETE on the heavy metals mixture HMM mediated oxido-inflammatory effects in the ovary and thyroid of female albino rats. Eight groups (5 female rats /group) were treated as follows for 60 days: Group 1: Deionized water only; Group 2: (Pb, Hg, Mn and Al); Group 3: HMM + ZnCl₂, 0.80 mg/kg; Group 4: HMM + Na₂SeO₃, 1.50 mg/kg; Group 5: HMM + ZnCl₂, 0.80 mg/kg and Na₂SeO₃, 1.50 mg/kg combined. On day 60 animals were euthanized, ovary and thyroid were harvested and used for, MDA, NO, antioxidants, TNF-α, IL-6, HMOX-1, Caspase-3, NF-KB, NRF2, HM and histopathology. There was significant bioaccumulation of Pb, Al, Hg and MN; elevated IL-6 and TNF-α, MDA and NO, caspase-3 and NRF2, NFKB and HMOX-1 with significant decrease in antioxidants in the HMM only group in comparison to the control. Co-treatment with ETE reversed most of these effects. ETE may ameliorate HMM -induced ovarian and thyrotoxicity in female albino rats by blunting oxido-inflammatory activities.

Emerging roles of ferroptosis in cardiovascular diseases

The mechanism of cardiovascular diseases (CVDs) is complex and threatens human health. Cardiomyocyte death is an important participant in the pathophysiological basis of CVDs. Ferroptosis is a new type of iron-dependent programmed cell death caused by excessive accumulation of iron-dependent lipid peroxides and reactive oxygen species (ROS) and abnormal iron metabolism. Ferroptosis differs from other known cell death pathways, such as apoptosis, necrosis, necroptosis, autophagy and pyroptosis. Several compounds have been shown to induce or inhibit ferroptosis by regulating related key factors or signalling pathways. Recent studies have confirmed that ferroptosis is associated with the development of diverse CVDs and may be a potential therapeutic drug target for CVDs. In this review, we summarize the characteristics and related mechanisms of ferroptosis and focus on its role in CVDs, with the goal of inspiring novel treatment strategies.

Analysis of the potential ferroptosis mechanism and multitemporal expression change of central ferroptosis-related genes in cardiac ischemia–reperfusion injury

Acute myocardial infraction is the most severe type of coronary artery disease and remains a substantial burden to the health care system globally. Although myocardial reperfusion is critical for ischemic cardiac tissue survival, the reperfusion itself could cause paradoxical injury. This paradoxical phenomenon is known as ischemia–reperfusion injury (IRI), and the exact molecular mechanism of IRI is still far from being elucidated and is a topic of controversy. Meanwhile, ferroptosis is a nonapoptotic form of cell death that has been reported to be associated with various cardiovascular diseases. Thus, we explored the potential ferroptosis mechanism and target in cardiac IRI via bioinformatics analysis and experiment. GSE4105 data were obtained from the GEO database and consist of a rat IRI model and control. After identifying differentially expressed ferroptosis-related genes (DEFRGs) and hub genes of cardiac IRI, we performed enrichment analysis, coexpression analysis, drug–gene interaction prediction, and mRNA–miRNA regulatory network construction. Moreover, we validated and explored the multitemporal expression of hub genes in a hypoxia/reoxygenation (H/R)-induced H9C2 cell injury model under different conditions via RT-qPCR. A total of 43 DEFRGs and 7 hub genes (tumor protein p53 [Tp53], tumor necrosis factor [Tnf], hypoxia-inducible factor 1 subunit alpha [Hif1a], interleukin 6 [Il6], heme oxygenase 1 [Hmox1], X-box binding protein 1 [Xbp1], and caspase 8 [Casp8]) were screened based on bioinformatics analysis. The functional annotation of these genes revealed apoptosis, and the related signaling pathways could have association with the pathogenesis of ferroptosis in cardiac IRI. In addition, the expression of the seven hub genes in IRI models were found higher than that of control under different H/R conditions and time points. In conclusion, the analysis of 43 DEFRGs and 7 hub genes could reveal the potential biological pathway and mechanism of ferroptosis in cardiac IRI. In addition, the multitemporal expression change of hub genes in H9C2 cells under different H/R conditions could provide clues for further ferroptosis mechanism exploring, and the seven hub genes could be potential biomarkers or therapeutic targets in cardiac IRI.

Multiplex analysis of mass imaging data: Application to the pathology of experimental myocardial infarction

Aim

Imaging mass cytometry (IMC) affords simultaneous immune‐labelling/imaging of multiple antigens in the same tissue. Methods utilizing multiplex data beyond co‐registration are lacking. This study developed and applied an innovative spatial analysis workflow for multiplex imaging data to IMC data determined from cardiac tissues and revealed the mechanism(s) of neutrophil‐mediated post‐myocardial‐infarction damage.

Methods

IMC produced multiplex images with various redox/inflammatory markers. The cardiac peri‐infarct zone (PIZ) was determined to be up to 240 µm from the infarct border based on the presence of neutrophils. The tissue region beyond the infarct was defined as the remote area (RA). ImageJ was used to quantify the immunoreactivity. Functional assessments included infarct size, cell necro/apoptosis, total thiol assay and echocardiogram.

Results

Expression of damage markers decreased in order from the infarct area to PIZ and then RA, reflecting the neutrophil density in the regions. Concentrically spaced “shoreline contour analysis” around the cardiac infarct extending into the PIZ showed that immunoreactivity for damage markers decreased linearly with increasing distance from the infarct, concomitant with a decreasing neutrophil‐myeloperoxidase (MPO) gradient from the infarct to the PIZ. Stratifying by concentric bands around individual MPO⁺‐signal identified that the immunoreactivity of haem‐oxygenase‐1 (HO‐1) and phosphorylated‐p38 mitogen‐activated protein kinase (pP38) peaked near neutrophils. Furthermore, spatial dependence between neutrophils and markers of cardiac cellular damage was confirmed by nearest‐neighbour distance analysis. Post‐infarction tissue exhibited declined functional parameters that were associated with neutrophil migration from the infarct to PIZ.

Conclusion

This image‐based quantitative protocol revealed the spatial association and provided potential molecular pathways responsible for neutrophil‐mediated damage post‐infarction.

Homocysteine, Vitamins B6 and Folic Acid in Experimental Models of Myocardial Infarction and Heart Failure—How Strong Is That Link?

Cardiovascular diseases are the leading cause of death and the main cause of disability. In the last decade, homocysteine has been found to be a risk factor or a marker for cardiovascular diseases, including myocardial infarction (MI) and heart failure (HF). There are indications that vitamin B6 plays a significant role in the process of transsulfuration in homocysteine metabolism, specifically, in a part of the reaction in which homocysteine transfers a sulfhydryl group to serine to form α-ketobutyrate and cysteine. Therefore, an elevated homocysteine concentration (hyperhomocysteinemia) could be a consequence of vitamin B6 and/or folate deficiency. Hyperhomocysteinemia in turn could damage the endothelium and the blood vessel wall and induce worsening of atherosclerotic process, having a negative impact on the mechanisms underlying MI and HF, such as oxidative stress, inflammation, and altered function of gasotransmitters. Given the importance of the vitamin B6 in homocysteine metabolism, in this paper, we review its role in reducing oxidative stress and inflammation, influencing the functions of gasotransmitters, and improving vasodilatation and coronary flow in animal models of MI and HF.

5,8-Dihydroxy-4 ′ , 7-dimethoxyflavone Attenuates TNF-α-Induced Expression of Vascular Cell Adhesion Molecule-1 through EGFR/PKCα/PI3K/Akt/Sp1-Dependent Induction of Heme Oxygenase-1 in Human Cardiac Fibroblasts

Recently, we found that 5,8-dihydroxy-4 ${}^{\text{’}}$ ,7-dimethoxyflavone (DDF) upregulated the expression of heme oxygenase (HO)-1 via p38 mitogen-activated protein kinase/nuclear factor-erythroid factor 2-related factor 2 (MAPK/Nrf2) pathway in human cardiac fibroblasts (HCFs). However, the alternative processes by which DDF induces the upregulation of HO-1 expression are unknown. Activation of epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), and protein kinase C (PKC)α may initiate specificity protein (Sp)1 activity, which has been reported to induce expression of antioxidant molecules. Thus, we explored whether these components are engaged in DDF-induced HO-1 upregulation in HCFs. Western blotting, promoter-reporter analyses, and real-time polymerase chain reactions were adopted to measure HO-1 and vascular cell adhesion molecule (VCAM)-1 expressions in HCFs. Respective small interfering (si)RNAs and pharmacological inhibitors were employed to investigate the signaling components engaged in DDF-induced HO-1 upregulation. The chromatin immunoprecipitation assay was conducted to detect the binding interaction of Sp1 and antioxidant response elements (ARE) on the promoter of HO-1. An adhesion assay of THP-1 monocyte was undertaken to examine the functional effect of HO-1 on tumor necrosis factor (TNF)-α-induced VCAM-1 expression. DDF stimulated the EGFR/PKCα/PI3K/Akt pathway leading to activation of Sp1 in HCFs. The roles of these protein kinases in HO-1 induction were ensured by transfection with their respective siRNAs. Chromatin immunoprecipitation assays revealed the interaction between Sp1 and the binding site of proximal ARE on the HO-1 promoter, which was abolished by glutathione, AG1478, Gö6976, LY294002, or mithramycin A. HO-1 expression enhanced by DDF abolished the monocyte adherence to HCFs and VCAM-1 expression induced by TNF-α. Pretreatment with an inhibitor of HO-1: zinc protoporphyrin IX reversed these inhibitory effects of HO-1. We concluded that DDF-induced HO-1 expression was mediated via an EGFR/PKCα/PI3K/Akt-dependent Sp1 pathway and attenuated the responses of inflammation in HCFs.

Traditional Chinese Medicine Targeting Heat Shock Proteins as Therapeutic Strategy for Heart Failure

Heart failure (HF) is the terminal stage of multifarious heart diseases and is responsible for high hospitalization rates and mortality. Pathophysiological mechanisms of HF include cardiac hypertrophy, remodeling and fibrosis resulting from cell death, inflammation and oxidative stress. Heat shock proteins (HSPs) can ameliorate folding of proteins, maintain protein structure and stability upon stress, protect the heart from cardiac dysfunction and ameliorate apoptosis. Traditional Chinese medicine (TCM) regulates expression of HSPs and has beneficial therapeutic effect in HF. In this review, we summarized the function of HSPs in HF and the role of TCM in regulating expression of HSPs. Studying the regulation of HSPs by TCM will provide novel ideas for the study of the mechanism and treatment of HF.

Role of Oxidative Stress in Heart Failure: Insights from Gene Transfer Studies

Under physiological circumstances, there is an exquisite balance between reactive oxygen species (ROS) production and ROS degradation, resulting in low steady-state ROS levels. ROS participate in normal cellular function and in cellular homeostasis. Oxidative stress is the state of a transient or a persistent increase of steady-state ROS levels leading to disturbed signaling pathways and oxidative modification of cellular constituents. It is a key pathophysiological player in pathological hypertrophy, pathological remodeling, and the development and progression of heart failure. The heart is the metabolically most active organ and is characterized by the highest content of mitochondria of any tissue. Mitochondria are the main source of ROS in the myocardium. The causal role of oxidative stress in heart failure is highlighted by gene transfer studies of three primary antioxidant enzymes, thioredoxin, and heme oxygenase-1, and is further supported by gene therapy studies directed at correcting oxidative stress linked to metabolic risk factors. Moreover, gene transfer studies have demonstrated that redox-sensitive microRNAs constitute potential therapeutic targets for the treatment of heart failure. In conclusion, gene therapy studies have provided strong corroborative evidence for a key role of oxidative stress in pathological remodeling and in the development of heart failure.

Forensic significance of intracardiac heme oxygenase-1 expression in acute myocardial ischemia

Heme oxygenase-1 (HO-1), an inducible stress-response protein, exerts anti-oxidant and anti-apoptotic effects. However, its significance in forensic diagnosis of acute ischemic heart diseases (AIHD) such as myocardial infarction (MI) is still unknown. We examined the immunohistochemical expression of HO-1 in the heart samples to discuss their forensic significance to determine acute cardiac ischemia. The heart samples were obtained from 23 AIHD cases and 33 non-AIHD cases as controls. HO-1 positive signals in cardiomyocyte nuclear were detected in 78.2% of AIHD cases, however, that were detected in only 24.2% control cases with statistical difference between AIHD and non-AIHD groups. In contrast to HO-1 protein expression, there was no significant difference in the appearance of myoglobin pallor regions and leukocyte infiltration in the hearts between AIHD and non-AIHD groups. From the viewpoints of forensic pathology, intracardiac HO-1 expression would be considered a valuable marker to diagnose AIHD as the cause of death.

Carbon Monoxide Releasing Molecule A1 Reduces Myocardial Damage After Acute Myocardial Infarction in a Porcine Model

ABSTRACT

Infarct size is a major determinant of outcomes after acute myocardial infarction (AMI). Carbon monoxide-releasing molecules (CORMs), which deliver nanomolar concentrations of carbon monoxide to tissues, have been shown to reduce infarct size in rodents. We evaluated efficacy and safety of CORM-A1 to reduce infarct size in a clinically relevant porcine model of AMI. We induced AMI in Yorkshire White pigs by inflating a coronary angioplasty balloon to completely occlude the left anterior descending artery for 60 minutes, followed by deflation of the balloon to mimic reperfusion. Fifteen minutes after balloon occlusion, animals were given an infusion of 4.27 mM CORM-A1 (n = 7) or sodium borate control (n = 6) over 60 minutes. Infarct size, cardiac biomarkers, ejection fraction, and hepatic and renal function were compared amongst the groups. Immunohistochemical analyses were performed to compare inflammation, cell proliferation, and apoptosis between the groups. CORM-A1-treated animals had significant reduction in absolute infarct area (158 ± 16 vs. 510 ± 91 mm2, P < 0.001) and infarct area corrected for area at risk (24.8% ± 2.6% vs. 45.2% ± 4.0%, P < 0.0001). Biochemical markers of myocardial injury also tended to be lower and left ventricular function tended to recover better in the CORM-A1 treated group. There was no evidence of hepatic or renal toxicity with the doses used. The cardioprotective effects of CORM-A1 were associated with a significant reduction in cell proliferation and inflammation. CORM-A1 reduces infarct size and improves left ventricular remodeling and function in a porcine model of reperfused MI by a reduction in inflammation. These potential cardioprotective effects of CORMs warrant further translational investigations.

Induction of Heme Oxygenase-1 Is Linked to the Severity of Disease in Human Abdominal Aortic Aneurysm

Background

Rupture of abdominal aortic aneurysm (rAAA) is associated with high case fatality rates, and risk of rupture increases with the AAA diameter. Heme oxygenase‐1 (gene HMOX1, protein HO‐1) is a stress‐induced protein and induction has protective effects in the vessel wall. HMOX1^−/− mice are more susceptible to angiotensin II‐induced AAA formation, but the regulation in human nonruptured and ruptured AAA is only poorly understood. Our hypothesis proposed that HO‐1 is reduced in AAA and lowering is inversely associated with the AAA diameter.

Methods and Results

AAA walls from patients undergoing elective open repair (eAAA) or surgery because of rupture (rAAA) were analyzed for aortic HMOX1/HO‐1 expression by quantitative real‐time polymerase chain reaction and Western blot. Aortas from patients with aortic occlusive disease served as controls. HMOX1/HO‐1 expression was 1.1‐ to 7.6‐fold upregulated in eAAA and rAAA. HO‐1 expression was 3‐fold higher in eAAA specimen with a diameter >84.4 mm, whereas HO‐1 was not different in rAAA. Other variables that are known for associations with AAA and HO‐1 induction were tested. In eAAA, HO‐1 expression was negatively correlated with aortic collagen content and oxidative stress parameters H₂O₂ release, oxidized proteins, and thiobarbituric acid reactive substances. Serum HO‐1 concentrations were analyzed in patients with eAAA, and maximum values were found in an aortic diameter of 55 to 70 mm with no further increase >70 mm, compared with <55 mm.

Conclusions

Aortic HO‐1 expression was increased in eAAA and rAAA. HO‐1 increased with the severity of disease but was additionally connected to less oxidative stress and vasoprotective mechanisms.

Shorter (GT)n repeats in the haem-oxygenase 1 gene promoter are associated with better mid-term survival in subjects with coronary artery disease and abnormal ejection fraction

BACKGROUND

Haem oxygenase (HO)-1 is a rate-limiting enzyme for degrading haem into carbon monoxide. Subjects with longer GT repeats in the HO-1 gene (HMOX1) promoter are more likely to have coronary artery disease (CAD) and cardiovascular events.

METHODS

We retrospectively enrolled CAD subjects with an abnormal ejection fraction (EF) <50% from our catheterisation data (N = 670). Polymerase chain reactions were performed for amplifying the HMOX1 promoter GT repeating segment to determine the number of repeats.

RESULTS

In a median follow-up period of 40 months, 213 patients died. The distribution of genotype for HMOX1 promoter GT repeating segments SS, SL, and LL were significantly different (p < 0.001) between the dead (44.6%, 36.2%, 19.2%, respectively) and the survived (53.8%, 37.4%, 8.8%, respectively) (S allele: ≤30 repeats, L allele: >30 repeats). In Cox regression analysis, carrier of S allele (hazard ratio 0.665, p = 0.027), a higher EF (hazard ratio 0.037, p = 0.001), and revascularization with PCI were all negatively associated with all-cause death in subjects with CAD and abnormal EF.

CONCLUSIONS

Carrier of shorter (GT)_n repeats of HMOX1 gene promoter was negatively correlated with death events in CAD patients with abnormal EF.

Pinocembrin ameliorates post-infarct heart failure through activation of Nrf2/HO-1 signaling pathway

Background

Oxidative stress is an important factor involved in the progress of heart failure. The current study was performed to investigate whether pinocembrin was able to ameliorate post-infarct heart failure (PIHF) and the underlying mechanisms.

Methods

Rats were carried out left anterior descending artery ligation to induce myocardial infarction and subsequently raised for 6 weeks to produce chronic heart failure. Then pinocembrin was administrated every other day for 2 weeks. The effects were evaluated by echocardiography, western blot, Masson’s staining, biochemical examinations, immunohistochemistry, and fluorescence. In vitro we also cultured H9c2 cardiomyocytes and cardiac myofibroblasts to further testify the mechanisms.

Results

We found that PIHF-induced deteriorations of cardiac functions were significantly ameliorated by administrating pinocembrin. In addition, the pinocembrin treatment also attenuated collagen deposition and augmented vascular endothelial growth factor receptor 2 in infarct border zone along with an attenuated apoptosis, which were related to an amelioration of oxidative stress evidenced by reduction of reactive oxygen species (ROS) in heart tissue and malondialdehyde (MDA) in serum, and increase of superoxide dismutase (SOD). This were accompanied by upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) pathway. In vitro experiments we found that specific Nrf2 inhibitor significantly reversed the effects resulted from pinocembrin including antioxidant, anti-apoptosis, anti-fibrosis and neovascularization, which further indicated the amelioration of PIHF by pinocembrin was in a Nrf2/HO-1 pathway-dependent manner.

Conclusion

Pinocembrin ameliorated cardiac functions and remodeling resulted from PIHF by ROS scavenging and Nrf2/HO-1 pathway activation which further attenuated collagen fibers deposition and apoptosis, and facilitated angiogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00363-7.

Influence of Consumption of Orange Juice (Citrus Sinensis) on Cardiac Remodeling of Rats Submitted to Myocardial Infarction

Fundamento

O suco de laranja (SL) é rico em polifenóis com propriedades anti-inflamatórias e antioxidantes. Após o infarto do miocárdio (IM), mudanças complexas ocorrem na estrutura e na função cardíacas, processo conhecido como remodelação cardíaca (RC). O estresse oxidativo e a inflamação podem modular esse processo. Nossa hipótese foi a de que o consumo de SL atenua a RC após o IM.

Objetivos

Avaliar a influência do SL sobre a RC após IM pela análise de variáveis funcionais, morfológicas, de estresse oxidativo, de inflação, e de metabolismo energético.

Métodos

Um total de 242 ratos machos pesando entre 200 e 250g foram submetidos a um procedimento cirúrgico (ligação da artéria coronária ou cirurgia simulada). Sete dia após a cirurgia, os animais sobreviventes foram divididos para um dos quatro grupos: 1) SM, animais sham que receberam água e maltodextrina (n= 20); 2) SSL, animais sham que receberam SL (n= 20); 3) IM, animais infartados que receberam água e maltodextrina (n= 40); e 4) ISL, animais infartados que receberam SL (n = 40). A análise estatística foi realizada pelo teste de ANOVA com dois fatores com o teste de Holm-Sidak. Os resultados foram apresentados em média ± desvio padrão, e o nível de significância adotado foi de 5%.

Resultados

Três meses depois, o IM levou à hipertrofia do ventrículo esquerdo (VE), com disfunção sistólica e diastólica, e aumento nos mediadores inflamatórios e de estresse oxidativo. Os animais que consumiram SL apresentaram menor atividade da glutationa peroxidase e maior expressão da heme-oxigenase-1 (HO-1).

Conclusão

O SL atenuou a RC, e a HO-1 pode exercer um importante papel nesse processo.

HO-1: A new potential therapeutic target to combat osteoporosis

Heme oxygenase-1 (HO-1) exerts a protective effect against cell damage and induces the activity of many enzymes involved in the treatment of many human diseases, including osteoporosis. The increasing prevalence of osteoporosis and the limitations of the current treatments available led to a continuous occurrence of bone loss and osteoporotic fractures, highlighting the need of a better understanding of the mechanism and function of HO-1. Many factors cause osteoporosis, including lack of estrogen, aging, and iron overload, and they either cause the increase in inflammatory factors or the increase in reactive oxygen species to break bone reconstruction balance. Therefore, regulating the production of inflammatory factors and reactive oxygen species may become a strategy for the treatment of osteoporosis. Solid evidence showed that the overexpression of HO-1 compensates high oxidation levels by increasing intracellular antioxidant levels and reduces inflammation by suppressing pro-inflammatory factors. Some extracts can target HO-1 and ameliorate osteoporosis. However, no systematic report is available on therapies targeting HO-1 to combat osteoporosis. Therefore, this review summarizes the biological characteristics of HO-1, and the relationship between inflammatory response and reactive oxygen species production regulated by HO-1 and osteoporosis. The understanding of the role of HO-1 in osteoporosis may provide ideas for a potential clinical treatment and new drugs targeting HO-1.

Nuclear factor erythroid 2-related factor 2 (Nrf2), tumor necrosis factor alpha protein (TNF-α), heme oxygenase-1 (HO-1) gene expressions during cardiopulmonary bypass

OBJECTIVE

During extracorporeal circulation, blood is in contact with nonendothelial surfaces. The increase in the amount of blood touching the non-endothelial surface increases the damage to the blood elements. This initiates and increases oxidative stress. Increased oxidative stress leads to the activation of antioxidant systems. These two systems work gradually in the process of Cardiopulmonary Bypass. This study aims to investigate the changes of TNF-α, Nrf2 and HO-1 gene expression in extracorporeal circulation.

MATERIALS AND METHODS

Fifteen patients who underwent open heart surgery were included in the study. Blood samples were taken preoperatively, during cardiopulmonary bypass (CPB) and 24 hours postoperatively. TNF-α, Nrf2 and HO-1 gene expressions in plasma samples were studied by using appropriate kits. Changes in gene expressions were compared.

RESULTS

TNF-α gene expression increased during CPB compared to preoperative levels (p <0.05). Similarly, Nrf-2 gene expression increased significantly during CPB (p <0.001) and decreased postoperatively (p <0.001). There was a significant increase in HO-1 gene expression during CPB (p <0.01). Postoperatively, this increase was found to decrease similar to Nrf2 (p <0.05).

CONCLUSIONS

According to the results, TNF-α, Nrf2, HO-1 gene expressions increase during CPB and these values decrease after the operation. This shows that oxidative stress and inflammatory processes start with CPB and antioxidant processes start similarly. With the termination of CPB, both processes are terminated. This has been demonstrated by gene expressions. Future studies will make it easier to understand these processes.

Metabolic Control by Heat Stress Determining Cell Fate to Ferroptosis for Effective Cancer Therapy

Flexible manipulation of the fate of cancer cells through exogenous stimulation-induced metabolic reprogramming could handle the cellular plasticity-derived therapies resistance, which provides an effective paradigm for the treatment of refractory and relapsing tumors in clinical settings. Herein, we demonstrated that moderate heat (45 °C) could significantly regress the expression of antioxidants and trigger specific lipid metabolic reprogramming in cancer cells synergized with iron oxide nanoparticles (Fe₃O₄ NPs). This metabolic control behavior destroyed the tumor redox homeostasis and produced overwhelming lipid peroxides, consequently sensitizing the tumor to ferroptosis. Based on these findings, a heat-triggered tumor-specific ferroptosis strategy was proposed by the rational design of a polypeptide-modified and 1H-perfluoropentane (1H-PFP)-encapsulated Fe₃O₄-containing nanoformulation (GBP@Fe₃O₄). When irradiated by an 808 nm laser, the phase transition of 1H-PFP was triggered by localized moderate heat (45 °C), leading to burst release of Fe₃O₄in situ to produce potent reactive oxygen species through the Fenton reaction in the tumor microenvironment. Together with the antioxidant inhibition response and distinctive lipid metabolic reprogramming by heat stress, this oxidative damage was amplified to induce tumor ferroptosis and achieve sufficient antitumor effects. Importantly, we confirmed that ACSBG1, an acyl-CoA synthetase, was the key pro-ferroptotic factor in this heat-induced ferroptosis process. Moreover, knockout of this gene could realize cancer cell death fate conversion from ferroptosis to non-ferroptotic death. This work provides mechanistic insights and practical strategies for heat-triggered ferroptosis in situ to reduce the potential side effects of direct ferroptosis inducers and highlights the key factor in regulating cell fate under heat stress.

Targeting Ferroptosis against Ischemia/Reperfusion Cardiac Injury

Ischemic heart disease is a leading cause of death worldwide. Primarily, ischemia causes decreased oxygen supply, resulting in damage of the cardiac tissue. Naturally, reoxygenation has been recognized as the treatment of choice to recover blood flow through primary percutaneous coronary intervention. This treatment is the gold standard therapy to restore blood flow, but paradoxically it can also induce tissue injury. A number of different studies in animal models of acute myocardial infarction (AMI) suggest that ischemia-reperfusion injury (IRI) accounts for up to 50% of the final myocardial infarct size. Oxidative stress plays a critical role in the pathological process. Iron is an essential mineral required for a variety of vital biological functions but also has potentially toxic effects. A detrimental process induced by free iron is ferroptosis, a non-apoptotic type of programmed cell death. Accordingly, efforts to prevent ferroptosis in pathological settings have focused on the use of radical trapping antioxidants (RTAs), such as liproxstatin-1 (Lip-1). Hence, it is necessary to develop novel strategies to prevent cardiac IRI, thus improving the clinical outcome in patients with ischemic heart disease. The present review analyses the role of ferroptosis inhibition to prevent heart IRI, with special reference to Lip-1 as a promising drug in this clinicopathological context.

Ferroptosis Is a Potential Novel Diagnostic and Therapeutic Target for Patients With Cardiomyopathy

Cardiomyocyte death is a fundamental progress in cardiomyopathy. However, the mechanism of triggering the death of myocardial cells remains unclear. Ferroptosis, which is the nonapoptotic, iron-dependent, and peroxidation-driven programmed cell death pathway, that is abundant and readily accessible, was not discovered until recently with a pharmacological approach. New researches have demonstrated the close relationship between ferroptosis and the development of many cardiovascular diseases, and several ferroptosis inhibitors, iron chelators, and small antioxidant molecules can relieve myocardial injury by blocking the ferroptosis pathways. Notably, ferroptosis is gradually being considered as an important cell death mechanism in the animal models with multiple cardiomyopathies. In this review, we will discuss the mechanism of ferroptosis and the important role of ferroptosis in cardiomyopathy with a special emphasis on the value of ferroptosis as a potential novel diagnostic and therapeutic target for patients suffering from cardiomyopathy in the future.

Hormone Replacement Therapy and Aging: A Potential Therapeutic Approach for Age-Related Oxidative Stress and Cardiac Remodeling

Advanced age is an independent risk factor for cardiovascular diseases, which might be further exacerbated by estrogen deficiency. Hormone replacement therapy (HRT) decreases cardiovascular risks and events in postmenopausal women; however, its effects are not fully elucidated in older individuals. Thus, the aim of our study is to examine the impact of HRT on oxidant/antioxidant homeostasis and cardiac remodeling. In our experiment, control (fertile) and aging (~20-month-old) female Wistar rats were used. Aging rats were further divided into estrogen- (E2, 0.1 mg/kg/day per os) or raloxifene- (RAL, 1.0 mg/kg/day per os) treated subgroups. After 2 weeks of treatment, cardiac heme oxygenase (HO) activity, total glutathione (GSH) content, matrix metalloproteinase-2 (MMP-2) activity, and the concentrations of collagen type I and tissue inhibitor of metalloproteinase (TIMP-2), as well as the infarct size, were determined. The aging process significantly decreased the antioxidant HO activity and GSH content, altered the MMP-2/TIMP-2 signaling, and resulted in an excessive collagen accumulation, which culminated in cardiovascular injury. However, 2 weeks of either E2 or RAL treatment enhanced the antioxidant defense mechanisms and attenuated cardiac remodeling related to aging. Our findings clearly show that 2-week-long HRT is a potential intervention to bias successful cardiovascular aging via reducing oxidative damage and cardiovascular dysfunction.

Subjects with coronary artery disease and reduced ejection fraction have longer (GT)n repeats in the heme-oxygenase 1 gene promoter

Heme oxygenase (HO)-1 is a rate-limiting enzyme for degrading heme into carbon monoxide. Longer (GT)_n repeat of the HO-1 gene (HMOX1) promoter has a lower transcription rate. Subjects with longer GT repeats in the HMOX1 promoter are more likely to have coronary artery disease (CAD) and cardiovascular events. We retrospectively enrolled CAD subjects with an abnormal ejection fraction (EF) < 50% from our catheterization data (N = 670). Polymerase chain reactions were performed for amplifying the HMOX1 promoter GT repeating segment to determine the number of repeats. Two subgroups, reduced EF < 40% (N = 256), and mid-range EF 40-49% (N = 414), were compared. The distribution of genotypes of SS, SL and LL were significantly different in reduced EF (29%, 48%, 23%) vs. mid-range EF CAD (64%, 30%, 5%) (S allele: ≤ 30 repeats, L allele: > 30 repeats) (p < 0.001). The patients with reduced EF had a significantly longer average (GT)_n (median 27.5 vs. 26.5, p = 0.004) than those with the mid-range EF. In multivariate analysis, the carrier of L allele (odds ratio 4.437, p < 0.001) was a significant predictor for the diagnosis of reduced vs. mid-range EF CAD. In conclusion, CAD patients with reduced EF had longer HMOX1 promoter (GT)_n repeats than those with mid-range EF.

Hmox1 (Heme Oxygenase-1) Protects Against Ischemia-Mediated Injury via Stabilization of HIF-1α (Hypoxia-Inducible Factor-1α)

OBJECTIVE

Hmox1 (heme oxygenase-1) is a stress-induced enzyme that catalyzes the degradation of heme to carbon monoxide, iron, and biliverdin. Induction of Hmox1 and its products protect against cardiovascular disease, including ischemic injury. Hmox1 is also a downstream target of the transcription factor HIF-1α (hypoxia-inducible factor-1α), a key regulator of the body's response to hypoxia. However, the mechanisms by which Hmox1 confers protection against ischemia-mediated injury remain to be fully understood. Approach and Results: Hmox1 deficient (Hmox1-/-) mice had impaired blood flow recovery with severe tissue necrosis and autoamputation following unilateral hindlimb ischemia. Autoamputation preceded the return of blood flow, and bone marrow transfer from littermate wild-type mice failed to prevent tissue injury and autoamputation. In wild-type mice, ischemia-induced expression of Hmox1 in skeletal muscle occurred before stabilization of HIF-1α. Moreover, HIF-1α stabilization and glucose utilization were impaired in Hmox1-/- mice compared with wild-type mice. Experiments exposing dermal fibroblasts to hypoxia (1% O2) recapitulated these key findings. Metabolomics analyses indicated a failure of Hmox1-/- mice to adapt cellular energy reprogramming in response to ischemia. Prolyl-4-hydroxylase inhibition stabilized HIF-1α in Hmox1-/- fibroblasts and ischemic skeletal muscle, decreased tissue necrosis and autoamputation, and restored cellular metabolism to that of wild-type mice. Mechanistic studies showed that carbon monoxide stabilized HIF-1α in Hmox1-/- fibroblasts in response to hypoxia.

CONCLUSIONS

Our findings suggest that Hmox1 acts both downstream and upstream of HIF-1α, and that stabilization of HIF-1α contributes to Hmox1's protection against ischemic injury independent of neovascularization.

Mitochondrial Membrane Intracellular Communication in Healthy and Diseased Myocardium

Research efforts in the twenty-first century have been paramount to the discovery and development of novel pharmacological treatments in a variety of diseases resulting in improved life expectancy. Yet, cardiac disease remains a leading cause of morbidity and mortality worldwide. Over time, there has been an expansion in conditions such as atrial fibrillation (AF) and heart failure (HF). Although past research has elucidated specific pathways that participate in the development of distinct cardiac pathologies, the exact mechanisms of action leading to disease remain to be fully characterized. Protein turnover and cellular bioenergetics are integral components of cardiac diseases, highlighting the importance of mitochondria and endoplasmic reticulum (ER) in driving cellular homeostasis. More specifically, the interactions between mitochondria and ER are crucial to calcium signaling, apoptosis induction, autophagy, and lipid biosynthesis. Here, we summarize mitochondrial and ER functions and physical interactions in healthy physiological states. We then transition to perturbations that occur in response to pathophysiological challenges and how this alters mitochondrial–ER and other intracellular organelle interactions. Finally, we discuss lifestyle interventions and innovative therapeutic targets that may be used to restore beneficial mitochondrial and ER interactions, thereby improving cardiac function.

Induction of HO-1 by 5, 8-Dihydroxy-4',7-Dimethoxyflavone via Activation of ROS/p38 MAPK/Nrf2 Attenuates Thrombin-Induced Connective Tissue Growth Factor Expression in Human Cardiac Fibroblasts

Heme oxygenase-1 (HO-1) has been shown to exert as an antioxidant and anti-inflammatory enzyme in cardiovascular inflammatory diseases. Flavonoids have been demonstrated to display anti-inflammatory and antioxidant effects through the induction of HO-1. 5,8-Dihydroxy-4',7-dimethoxyflavone (DDF), one of the flavonoid compounds, is isolated from Reevesia formosana. Whether DDF induced HO-1 expression on human cardiac fibroblasts (HCFs) remained unknown. Here, we found that DDF time- and concentration-dependently induced HO-1 protein and mRNA expression, which was attenuated by pretreatment with reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC) in HCFs. DDF-enhanced ROS generation was attenuated by NAC, but not by either diphenyleneiodonium chloride (DPI, Nox inhibitor) or MitoTempol (mitochondrial ROS scavenger). Interestingly, pretreatment with glutathione (GSH) inhibited DDF-induced HO-1 expression. The ratio of GSH/GSSG was time-dependently decreased in DDF-treated HCFs. DDF-induced HO-1 expression was attenuated by an inhibitor of p38 MAPK (p38i VIII) or siRNA, but not by MEK1/2 (PD98059) or JNK1/2 (SP600125). DDF-stimulated p38 MAPK phosphorylation was inhibited by GSH or p38i VIII. Moreover, DDF-induced HO-1 expression was mediated through Nrf2 phosphorylation and translocation into the nucleus which was attenuated by NAC or p38 siRNA. DDF also stimulated antioxidant response element (ARE) promoter activity which was inhibited by NAC, GSH, or p38i VIII. Interaction between Nrf2 and the ARE-binding sites on the HO-1 promoter was revealed by chromatin immunoprecipitation assay, which was attenuated by NAC, GSH, or p38i VIII. We further evaluated the functional effect of HO-1 expression on the thrombin-induced fibrotic responses. Our result indicated that the induction of HO-1 by DDF can attenuate the thrombin-induced connective tissue growth factor expression. These results suggested that DDF-induced HO-1 expression is, at least, mediated through the activation of the ROS-dependent p38 MAPK/Nrf2 signaling pathway in HCFs. Thus, the upregulation of HO-1 by DDF could be a candidate for the treatment of heart fibrosis.

Pathological Cardiopulmonary Evaluation of Rats Chronically Exposed to Traffic-Related Air Pollution

BACKGROUND

Traffic-related air pollution (TRAP) is made up of complex mixtures of particulate matter, gases and volatile compounds. However, the effects of TRAP on the cardiopulmonary system in most animal studies have been tested using acute exposure to singular pollutants. The cardiopulmonary effects and molecular mechanisms in animals that are chronically exposed to unmodified air pollution as a whole have yet to be studied. Additionally, sex-dependent toxicity of TRAP exposure has rarely been evaluated.

OBJECTIVES

This study sought to assess the cardiopulmonary effect of chronic exposure to unmodified, real-world TRAP in both female and male rats.

METHODS

Four-week-old male and female rats were exposed to TRAP or filtered air for 14 months in a novel facility drawing air from a major freeway tunnel system in Northern California. Inflammation and oxidative stress markers were examined in the lung, heart, spleen, and plasma, and TRAP deposits were quantified in the lungs of both male and female rats.

RESULTS

Elemental analysis showed higher levels of eight elements in the female lungs and one element in the male lungs. Expression of genes related to fibrosis, aging, oxidative stress, and inflammation were higher in the rat hearts exposed to TRAP, with female rats being more susceptible than males. Enhanced collagen accumulation was found only in the TRAP-exposed female hearts. Plasma cytokine secretion was higher in both female and male rats, but inflammatory macrophages were higher only in TRAP-exposed male spleens.

DISCUSSION

Our results in rats suggest pathological consequences from chronic TRAP exposure, including sex differences indicating females may be more susceptible to TRAP-induced cardiac fibrosis. https://doi.org/10.1289/EHP7045.

Ling-Gui-Zhu-Gan Decoction Protects H9c2 Cells against H2O2-Induced Oxidative Injury via Regulation of the Nrf2/Keap1/HO-1 Signaling Pathway

OBJECTIVES

Ling-Gui-Zhu-Gan decoction (LGZGD) is a potentially effective treatment for heart failure, and it showed significant anti-inflammatory potential in our previous studies. However, its ability to ameliorate heart failure through regulation of oxidative stress response is still unknown. This study was aimed to investigate the protective effect of LGZGD-containing serum on H2O2-induced oxidative injury in H9c2 cells and explore the underlying mechanism.

METHODS

Eighteen rats were randomly divided into two groups: the blank control group and LGZGD group. The LGZGD group rats were administrated with 8.4 g/kg/d LGZGD for seven consecutive days through gavage, while the blank control group rats were given an equal volume of saline. The serum was extracted from all the rats. To investigate the efficacy and the underlying mechanism of LGZGD, we categorized the H9c2 cells into groups: the control group, model group, normal serum control (NSC) group, LGZGD group, LGZGD + all-trans-retinoic acid (ATRA) group, and ATRA group. Malonedialdehyde (MDA) and superoxide dismutase (SOD) were used as markers for oxidative stress. Dichlorodihydrofluorescin diacetate (DCFH-DA) staining was used to measure the levels of reactive oxygen species (ROS). The apoptosis rate was detected using flow cytometry. The expression levels of pro-caspase-3, cleaved-caspase-3, Bcl-2, Bax, Keap1, Nrf2, and HO-1 were measured using western blotting. The mRNA levels of Keap1, Nrf2, and HO-1 were measured using RT-qPCR.

RESULTS

The LGZGD attenuated injury to H9c2 cells and reduced the apoptosis rate. It was also found to upregulate the SOD activity and suppress the formation of MDA and ROS. The expression levels of pro-caspase-3 and Bcl-2 were significantly increased, while those of cleaved-caspase-3 and Bax were decreased in the LGZGD group compared with the model group. As compared with the model group, the LGZGD group demonstrated decreased Keap1 protein expression and significantly increased Nrf2 nuclear expression and Nrf2-mediated transcriptional activity. ATRA was found to reverse the LGZGD-mediated antioxidative and antiapoptotic effect on injured H9c2 cells induced by H2O2.

CONCLUSION

Our results demonstrated that LGZGD attenuated the H2O2-induced injury to H9c2 cells by inhibiting oxidative stress and apoptosis via the Nrf2/Keap1/HO-1 pathway. These observations suggest that LGZGD might prevent and treat heart failure through regulation of the oxidative stress response.

Carbon monoxide attenuates LPS-induced myocardial dysfunction in rats by regulating the mitochondrial dynamic equilibrium

Lipopolysaccharide (LPS) induces myocardial dysfunction by damaging the mitochondrial structure in cardiomyocytes. Since low levels of carbon monoxide can confer cytoprotective effects against end-organ damage from endotoxic shock, we tested whether treatment with carbon monoxide-releasing molecule-2 (CORM-2) could ameliorate LPS-induced myocardial dysfunction in rats by maintaining the dynamic equilibrium between the mitochondrial fusion and fission processes. Cardiac function, myocardial histopathology, myocardial enzymes, and changes in myocardial mitochondrial function and mitochondrial fusion-fission protein expression were assessed in rats. The mitochondrial structure and morphology were studied by electron microscopy, and the expression levels of key proteins involved in the mitochondrial dynamics were assessed by Western blot assay. Cardiac dysfunction and increased myocardial enzyme activity together with myocardial pathological damage, mitochondrial dysfunction, and impaired mitochondrial dynamics homeostasis were observed in the LPS-challenged septic rats. However, these observations were reversed by CORM-2, which effectively inhibited cardiac and mitochondrial damage in the LPS-challenged rats and improved the survival rate of the animals. In conclusion, CORM-2 regulates the LPS-induced imbalance of the dynamic mitochondrial fusion and fission processes, thereby effectively ameliorating the LPS-induced myocardial dysfunction and improving the survival of the rats.

Lansoprazole alleviates pressure overload-induced cardiac hypertrophy and heart failure in mice by blocking the activation of β-catenin

AIMS

Proton pump inhibitors (PPIs) are widely used in patients receiving percutaneous coronary intervention to prevent gastric bleeding, but whether PPIs are beneficial for the heart is controversial. Here, we investigated the effects of lansoprazole on cardiac hypertrophy and heart failure, as well as the underlying mechanisms.

METHODS AND RESULTS

Adult male C57 mice were subjected to transverse aortic constriction (TAC) or sham surgery and then were treated with lansoprazole or vehicle for 5 weeks. In addition, cultured neonatal rat ventricular cardiomyocytes and fibroblasts were exposed to angiotensin II in the presence or absence of lansoprazole. At 5 weeks after TAC, the heart weight/body weight ratio was lower in lansoprazole-treated mice than in untreated mice, as was the lung weight/body weight ratio, while left ventricular (LV) fractional shortening and the maximum and minimum rates of change of the LV pressure were higher in lansoprazole-treated mice, along with less cardiac fibrosis. In cultured cardiomyocytes, lansoprazole inhibited angiotensin II-induced protein synthesis and hypertrophy, as well as inhibiting proliferation of fibroblasts. Lansoprazole decreased myocardial levels of phosphorylated Akt, phosphorylated glycogen synthase kinase 3β, and active β-catenin in TAC mice and in angiotensin II-stimulated cardiomyocytes. After overexpression of active β-catenin or knockdown of H+/K+-ATPase α-subunit, lansoprazole still significantly attenuated myocyte hypertrophy.

CONCLUSION

Lansoprazole inhibits cardiac remodelling by suppressing activation of the Akt/GSK3β/β-catenin pathway independent of H+/K+-ATPase inhibition, and these findings may provide a novel insight into the pharmacological effects of PPIs with regard to alleviation of cardiac remodelling.

Cardioprotection by AN-7, a prodrug of the histone deacetylase inhibitor butyric acid: Selective activity in hypoxic cardiomyocytes and cardiofibroblasts

The anticancer prodrug butyroyloxymethyl diethylphosphate (AN-7), upon metabolic hydrolysis, releases the histone deacetylase inhibitor butyric acid and imparts histone hyperacetylation. We have shown previously that AN-7 increases doxorubicin-induced cancer cell death and reduces doxorubicin toxicity and hypoxic damage to the heart and cardiomyocytes. The cardiofibroblasts remain unprotected against both insults. Herein we examined the selective effect of AN-7 on hypoxic cardiomyocytes and cardiofibroblasts and investigated mechanisms underlying the cell specific response. Hypoxic cardiomyocytes and cardiofibroblasts or H₂O₂-treated H9c2 cardiomyoblasts, were treated with AN-7 and cell damage and death were evaluated as well as cell signaling pathways and the expression levels of heme oxygenase-1 (HO-1). AN-7 diminished hypoxia-induced mitochondrial damage and cell death in hypoxic cardiomyocytes and reduced hydrogen peroxide damage in H9c2 cells while increasing cell injury and death in hypoxic cardiofibroblasts. In the cell line, AN-7 induced Akt and ERK survival pathway activation in a kinase-specific manner including phosphorylation of the respective downstream targets, GSK-3β and BAD. Hypoxic cardiomyocytes responded to AN-7 treatment by enhanced phosphorylation of Akt, ERK, GSK-3β and BAD and a significant 6-fold elevation in HO-1 levels. In hypoxic cardiofibroblasts, AN-7 did not activate Akt and ERK beyond the effect of hypoxia alone and induced a limited (~1.5-fold) increase in HO-1. The cell specific differences in kinase activation and in heme oxygenase-1 upregulation may explain, at least in part, the disparate outcome of AN-7 treatment in hypoxic cardiomyocytes and hypoxic cardiofibroblasts.

CO-Releasing Molecule (CORM)-3 Ameliorates Spinal Cord-Blood Barrier Disruption Following Injury to the Spinal Cord

Spinal cord injury (SCI) is a clinical tough neurological problem without efficient cure currently. Blood-spinal cord barrier (BSCB) interruption is not only a crucial pathological feature for SCI process but is a possible target for future SCI treatments; however, few treatments have been developed to intervene BSCB. In the present study, we intravenously injected CO-releasing molecule3 (CORM-3), a classical exogenous CO donor, to the rats experiencing SCI and assessed its protection on BSCB integrity in rats. Our results demonstrated that the exogenous increasing of CO by CORM-3 blocked the tight junction (TJ) protein degeneration and neutrophils infiltration, subsequently suppressed the BSCB damage and improved the motor recovery after SCI. And we certified that the CO-induced down-regulation of MMP-9 expression and activity in neutrophil might be associated with the NF-κB signaling. Taken together, our study indicates that CO-releasing molecule (CORM)-3 ameliorates BSCB after spinal cord injury.