Dusp6 deficiency attenuates neutrophil-mediated cardiac damage in the acute inflammatory phase of myocardial infarction

TRIM11 expression levels was downregulated and prevents ferroptosis of cardiomyocyte by Dusp6 in acute myocardial infarction

Acute myocardial infarction (AMI) is the high incidence rate and mortality of common cardiovascular disease. Herein, we explored the critical role of TRIM11 in AMI and its underlying mechanism. Serum from patients with AMI were collected from our hospital. Mice of model group received angiotensin II. Mice of model + TRIM11 group received with Ang II and TRIM11 vectors. Mice of sham group received normal saline. H9c2 cells were performed transfections using Lipofectamine 2000 (Thermo Fisher Scientific Inc, Shanghai, China), and treated with Ang II. TRIM11 mRNA expression was reduced, was negative correlation with collagen I/III mRNA expression, systolic blood pressure, diastolic blood pressure, left anteroposterior atrial diameter, right atrial diameter, or left ventricular ejection fraction in patient with AMI. TRIM11 mRNA and protein expression were also suppressed. METTL3 regulates TRIM11 methylation to reduce TRIM11 gene stability in model of AMI. TRIM11 gene ameliorated AMI in mice model. TRIM11 gene reduced reactive oxygen species production level of cardiomyocyte in-vitro model. TRIM11 gene reduced ferroptosis of cardiomyocyte in-vitro model. TRIM11 gene reduced ferroptosis by the inhibition of mitochondrial damage of cardiomyocyte in model of AMI. TRIM11 induced Dusp6 protein expression. Bioluminescence imaging showed that TRIM11 virus increased Dusp6 expression in heart tissue of mice model. The inhibition of Dusp6 reduced the effects of TRIM11 on ferroptosis of cardiomyocyte in model of AMI. In conclusion, this study demonstrates that TRIM11 improves AMI by regulating Dusp6 to inhibit ferroptosis of cardiomyocyte, and suggest a novel target for AMI.

Integration of network pharmacology and proteomics analysis to identify key target pathways of Ginsenoside Re for myocardial ischemia

BACKGROUND

Clinically, various diseases cause myocardial ischemia (MI), which further induces severe cardiac injury and leads to high mortality in patients. Ginsenoside Re, one of the major ginsenosides in ginseng, can regulate the level of oxidative stress in the injured myocardium. Thus, it may attenuate MI injury, but the related mechanism has not been comprehensively studied.

PURPOSE

This study aimed to investigate the anti-MI effect and comprehensively mechanisms of Ginsenoside Re.

STUDY DESIGN/METHODS

Oxygen-glucose deprivation (OGD), oxidative-induced cardiomyocyte injury, and isoproterenol-induced MI mice were used to explore their protective effect of Ginsenoside Re. An integrated approach of network pharmacology, molecular docking, and tandem mass tag proteomics was applied to determine the corresponding common potential targets of Ginsenoside Re against MI, such as target proteins and related pathways. The major anti-MI target proteins and related pathways were validated by immunofluorescence (IF) assay and Western blotting (WB).

RESULTS

Ginsenoside Re (1.32-168.93 µM) had low toxicity to normal cardiomyocytes, and increased the survival of oxidative stress-injured (OGD-induced injury or H2O2-induced injury) cardiomyocytes in this concentration range. It regulated the reactive oxygen species (ROS) level in OGD-injured cardiomyocytes; stabilized the nuclear morphology, mitochondrial membrane potential (MMP), and mitochondrial function; and reduced apoptosis. Meanwhile, Ginsenoside Re (5-20 mg/kg) alleviated cardiac injury in MI mice and maintained cardiac function. Through network pharmacology and proteomics, the relevant mechanisms revealed several key pathways of Ginsenoside Re anti-MI, including inhibition of MAPK pathway protein phosphorylation, downregulation of phosphorylated PDPK1, AKT, and STAT3, and upregulation of TGF-β3, ferroptosis pathway (upregulation of GPX4 and downregulation of phosphorylation level of MDM2) and AMPK pathway (regulating the synthesis of cholesterol in the myocardium by downregulation of HMGCR). The key proteins of these target pathways were validated by IF and/or WB.

CONCLUSION

Ginsenoside Re may target MAPK, AKT, ferroptosis pathways and AMPK pathway to prevent and/or treat MI injury and protect cardiomyocytes from oxidative damage.

IL-1 signaling pathway, an important target for inflammation surrounding in myocardial infarction

Acute myocardial infarction is an important cardiovascular disease worldwide. Although the mortality rate of myocardial infarction (MI) has improved dramatically in recent years due to timely treatment, adverse remodeling of the left ventricle continues to affect cardiac function. Various immune cells are involved in this process to induce inflammation and amplification. The infiltration of inflammatory cells in the infarcted myocardium is induced by various cytokines and chemokines, and the recruitment of leukocytes further amplifies the inflammatory response. As an increasing number of clinical anti-inflammatory therapies have achieved significant success in recent years, treating myocardial infarction by targeting inflammation may become a novel therapeutic option. In particular, successful clinical trials of canakinumab have demonstrated the important role of the inflammatory factor interleukin-1 (IL-1) in atherosclerosis. Targeted IL-1 therapy may decrease inflammation levels and improve cardiac function in patients after myocardial infarction. This article reviews the complex series of responses after myocardial infarction, including the involvement of inflammatory cells and the role of cytokines and chemokines, focusing on the progression of the IL-1 family in myocardial infarction as well as the performance of current targeted therapy drugs in experiments.

H3K27ac acts as a molecular switch for doxorubicin-induced activation of cardiotoxic genes

BACKGROUND

Doxorubicin (Dox) is an effective chemotherapeutic drug for various cancers, but its clinical application is limited by severe cardiotoxicity. Dox treatment can transcriptionally activate multiple cardiotoxicity-associated genes in cardiomyocytes, the mechanisms underlying this global gene activation remain poorly understood.

METHODS AND RESULTS

Herein, we integrated data from animal models, CUT&Tag and RNA-seq after Dox treatment, and discovered that the level of H3K27ac (a histone modification associated with gene activation) significantly increased in cardiomyocytes following Dox treatment. C646, an inhibitor of histone acetyltransferase, reversed Dox-induced H3K27ac accumulation in cardiomyocytes, which subsequently prevented the increase of Dox-induced DNA damage and apoptosis. Furthermore, C646 alleviated cardiac dysfunction in Dox-treated mice by restoring ejection fraction and reversing fractional shortening percentages. Additionally, Dox treatment increased H3K27ac deposition at the promoters of multiple cardiotoxic genes including Bax, Fas and Bnip3, resulting in their up-regulation. Moreover, the deposition of H3K27ac at cardiotoxicity-related genes exhibited a broad feature across the genome. Based on the deposition of H3K27ac and mRNA expression levels, several potential genes that might contribute to Dox-induced cardiotoxicity were predicted. Finally, the up-regulation of H3K27ac-regulated cardiotoxic genes upon Dox treatment is conservative across species.

CONCLUSIONS

Taken together, Dox-induced epigenetic modification, specifically H3K27ac, acts as a molecular switch for the activation of robust cardiotoxicity-related genes, leading to cardiomyocyte death and cardiac dysfunction. These findings provide new insights into the relationship between Dox-induced cardiotoxicity and epigenetic regulation, and identify H3K27ac as a potential target for the prevention and treatment of Dox-induced cardiotoxicity.

Novel strategies for targeting neutrophil against myocardial infarction

Inflammation is a crucial factor in cardiac remodeling after acute myocardial infarction (MI). Neutrophils, as the first wave of leukocytes to infiltrate the injured myocardium, exacerbate inflammation and cardiac injury. However, therapies that deplete neutrophils to manage cardiac remodeling after MI have not consistently produced promising outcomes. Recent studies have revealed that neutrophils at different time points and locations may have distinct functions. Thus, transferring neutrophil phenotypes, rather than simply blocking their activities, potentially meet the needs of cardiac repair. In this review, we focus on discussing the fate, heterogeneity, functions of neutrophils, and attempt to provide a more comprehensive understanding of their roles and targeting strategies in MI. We highlight the strategies and translational potential of targeting neutrophils to limit cardiac injury to reduce morbidity and mortality from MI.

DUSP6 deletion protects mice and reduces disease severity in autoimmune arthritis

Receptor tyrosine kinases (RTKs) have an important role in arthritis severity and in models of rheumatoid arthritis (RA), but their regulation is not fully understood. The dual specificity phosphatase 6 (DUSP6) has been implicated in the regulation of RTK signaling, but never in the context of arthritis and autoimmunity. We used the KRN serum-induced arthritis (KSIA) model of RA and showed that DUSP6-/- mice were protected and had a 50% lower maximum arthritis score (p = 0.006) and reduced joint damage than C57BL/6 DUSP6+/+ controls. Serum levels of interleukin (IL) 10 were significantly increased (>2-fold), and IL6 decreased in DUSP6-/- mice. DUSP6-/- mice had increased numbers of IL10+ cells including Tr1 regulatory cells (p < 0.01). Introduction of the IL10-/- into DUSP6-/- (double knockout [KO]) reversed the DUSP6-/- protection. In conclusion, this study reports a pro-arthritic role for DUSP6. This discovery has the potential to generate a previously unknown target for therapies for RA and inflammatory diseases.

Calcium saccharate/DUSP6 suppresses renal cell carcinoma glycolytic metabolism and boosts sunitinib efficacy via the ERK-AKT pathway

Current therapeutic options for renal cell carcinoma (RCC) are very limited, which is largely due to inadequate comprehension of molecular pathological mechanisms as well as RCC's resistance to chemotherapy. Dual-specificity phosphatase 6 (DUSP6) has been associated with numerous human diseases. However, its role in RCC is not well understood. Here, we show that diminished DUSP6 expression is linked to RCC progression and unfavorable prognosis. Mechanistically, DUSP6 serves as a tumor suppressor in RCC by intervening the TAF10 and BSCL2 via the ERK-AKT pathway. Further, DUSP6 is also transcriptionally regulated by HNF-4a. Moreover, docking experiments have indicated that DUSP6 expression is enhanced when bound by Calcium saccharate, which also inhibits RCC cell proliferation, metabolic rewiring, and sunitinib resistance. In conclusion, our study identifies Calcium saccharate as a prospective pharmacological therapeutic approach for RCC.

Value of DUSP6 in peripheral blood mononuclear cells in predicting adverse cardiovascular events after peritoneal dialysis in diabetic nephropathy

OBJECTIVES

Adverse cardiovascular events are the leading cause of death in peritoneal dialysis patients. Identifying indicators that can predict adverse cardiovascular events in these patients is crucial for prognosis. This study aims to assess the value of dual-specificity phosphatase 6 (DUSP6) in peripheral blood mononuclear cells as a predictor of adverse cardiovascular events after peritoneal dialysis in diabetic nephropathy patients.

METHODS

A total of 124 diabetic nephropathy patients underwent peritoneal dialysis treatment at the Department of Nephrology of the First Affiliated Hospital of Hebei North University from June to September 2022 were selected as study subjects. The levels of DUSP6 in peripheral blood mononuclear cells were determined using Western blotting. Patients were categorized into high-level and low-level DUSP6 groups based on the median DUSP6 level. Differences in body mass index, serum albumin, high-sensitivity C-reactive protein, and dialysis duration were compared between the 2 groups. Pearson, Spearman, and multiple linear regression analyses were performed to examine factors related to DUSP6. Patients were followed up to monitor the occurrence of adverse cardiovascular events, and risk factors for adverse cardiovascular events after peritoneal dialysis were analyzed using Kaplan-Meier and Cox regression.

RESULTS

By the end of the follow-up, 33 (26.61%) patients had experienced at least one adverse cardiovascular event. The high-level DUSP6 group had higher body mass index, longer dialysis duration, and higher high-sensitivity C-reactive protein, but lower serum albumin levels compared to the low-level DUSP6 group (all P<0.05). DUSP6 was negatively correlated with serum albumin levels (r=-0.271, P=0.002) and positively correlated with dialysis duration (rs=0.406, P<0.001) and high-sensitivity C-reactive protein (rs=0.367, P<0.001). Multiple linear regression analysis revealed that dialysis duration and high-sensitivity C-reactive protein were independently correlated with DUSP6 levels (both P<0.05). The cumulative incidence of adverse cardiovascular events was higher in the high-level DUSP6 group than in the low-level DUSP6 group (46.67% vs 7.81%, P<0.001). Cox regression analysis indicated that low serum albumin levels (HR=0.836, 95% CI 0.778 to 0.899), high high-sensitivity C-reactive protein (HR=1.409, 95% CI 1.208 to 1.644), and high DUSP6 (HR=6.631, 95% CI 2.352 to 18.693) were independent risk factors for adverse cardiovascular events in peritoneal dialysis patients.

CONCLUSIONS

Dialysis duration and high-sensitivity C-reactive protein are independently associated with DUSP6 levels in peripheral blood mononuclear cells of diabetic nephropathy patients undergoing peritoneal dialysis. High DUSP6 levels indicate a higher risk of adverse cardiovascular events.

Targeting the redox system for cardiovascular regeneration in aging

Cardiovascular aging presents a formidable challenge, as the aging process can lead to reduced cardiac function and heightened susceptibility to cardiovascular diseases. Consequently, there is an escalating, unmet medical need for innovative and effective cardiovascular regeneration strategies aimed at restoring and rejuvenating aging cardiovascular tissues. Altered redox homeostasis and the accumulation of oxidative damage play a pivotal role in detrimental changes to stem cell function and cellular senescence, hampering regenerative capacity in aged cardiovascular system. A mounting body of evidence underscores the significance of targeting redox machinery to restore stem cell self-renewal and enhance their differentiation potential into youthful cardiovascular lineages. Hence, the redox machinery holds promise as a target for optimizing cardiovascular regenerative therapies. In this context, we delve into the current understanding of redox homeostasis in regulating stem cell function and reprogramming processes that impact the regenerative potential of the cardiovascular system. Furthermore, we offer insights into the recent translational and clinical implications of redox-targeting compounds aimed at enhancing current regenerative therapies for aging cardiovascular tissues.

Circadian clock1a coordinates neutrophil recruitment via nfe212a/duox-reactive oxygen species pathway in zebrafish

Neutrophil recruitment to inflammatory sites appears to be an evolutionarily conserved strategy to fight against exogenous insults. However, the rhythmic characteristics and underlying mechanisms of neutrophil migration on a 24-h timescale are largely unknown. Using the advantage of in vivo imaging of zebrafish, this study explored how the circadian gene clock1a dynamically regulates the rhythmic recruitment of neutrophils to inflammatory challenges. We generated a clock1a mutant and found that neutrophil migration is significantly increased in caudal fin injury and lipopolysaccharide (LPS) injection. Transcriptome sequencing, chromatin immunoprecipitation (ChIP), and dual-luciferase reporting experiments suggest that the clock1a gene regulates neutrophil migration by coordinating the rhythmic expression of nfe212a and duox genes to control the reactive oxygen species (ROS) level. This study ultimately provides a visual model to expand the understanding of the rhythmic mechanisms of neutrophil recruitment on a circadian timescale in a diurnal organism from the perspective of ROS.

The Emerging Role of Protein Phosphatase in Regeneration

Maintaining normal cellular behavior is essential for the survival of organisms. One of the main mechanisms to control cellular behavior is protein phosphorylation. The process of protein phosphorylation is reversible under the regulation of protein kinases and protein phosphatases. The importance of kinases in numerous cellular processes has been well recognized. In recent years, protein phosphatases have also been demonstrated to function actively and specifically in various cellular processes and thus have gained more and more attention from researchers. In the animal kingdom, regeneration frequently occurs to replace or repair damaged or missing tissues. Emerging evidence has revealed that protein phosphatases are crucial for organ regeneration. In this review, after providing a brief overview of the classification of protein phosphatases and their functions in several representative developmental processes, we highlight the critical roles that protein phosphatases play in organ regeneration by summarizing the most recent research on the function and underlying mechanism of protein phosphatase in the regeneration of the liver, bone, neuron, and heart in vertebrates.

A DUSP6 inhibitor suppresses inflammatory cardiac remodeling and improves heart function after myocardial infarction

Acute myocardial infarction (MI) results in loss of cardiomyocytes and abnormal cardiac remodeling with severe inflammation and fibrosis. However, how cardiac repair can be achieved by timely resolution of inflammation and cardiac fibrosis remains incompletely understood. Our previous findings have shown that dual-specificity phosphatase 6 (DUSP6) is a regeneration repressor from zebrafish to rats. In this study, we found that intravenous administration of the DUSP6 inhibitor (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI) improved heart function and reduced cardiac fibrosis in MI rats. Mechanistic analysis revealed that BCI attenuated macrophage inflammation through NF-κB and p38 signaling, independent of DUSP6 inhibition, leading to the downregulation of various cytokines and chemokines. In addition, BCI suppressed differentiation-related signaling pathways and decreased bone-marrow cell differentiation into macrophages through inhibiting DUSP6. Furthermore, intramyocardial injection of poly (D, L-lactic-co-glycolic acid)-loaded BCI after MI had a notable effect on cardiac repair. In summary, BCI improves heart function and reduces abnormal cardiac remodeling by inhibiting macrophage formation and inflammation post-MI, thus providing a promising pro-drug candidate for the treatment of MI and related heart diseases. This article has an associated First Person interview with the first author of the paper.

Regeneration of the heart: from molecular mechanisms to clinical therapeutics

Heart injury such as myocardial infarction leads to cardiomyocyte loss, fibrotic tissue deposition, and scar formation. These changes reduce cardiac contractility, resulting in heart failure, which causes a huge public health burden. Military personnel, compared with civilians, is exposed to more stress, a risk factor for heart diseases, making cardiovascular health management and treatment innovation an important topic for military medicine. So far, medical intervention can slow down cardiovascular disease progression, but not yet induce heart regeneration. In the past decades, studies have focused on mechanisms underlying the regenerative capability of the heart and applicable approaches to reverse heart injury. Insights have emerged from studies in animal models and early clinical trials. Clinical interventions show the potential to reduce scar formation and enhance cardiomyocyte proliferation that counteracts the pathogenesis of heart disease. In this review, we discuss the signaling events controlling the regeneration of heart tissue and summarize current therapeutic approaches to promote heart regeneration after injury.