Navarixin alleviates cardiac remodeling after myocardial infarction by decreasing neutrophil infiltration and the inflammatory response
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ABSTRACT: Introduction: Coronary atherosclerotic heart disease is an important, worldwide burden on human health. Central muscle infarction is the most dangerous condition, has the highest mortality and disability rates, and is gradually becoming more common among young people. After myocardial infarction, neutrophils recruited to the infarcted area promote the myocardial inflammatory response by releasing proinflammatory factors and chemokines and release matrix metalloproteinases and myeloperoxidases that degrade the extracellular matrix and produce reactive oxygen species, resulting in irreversible myocardial damage and thereby promoting ventricular remodeling. Methods: In this study, we constructed a mouse model of myocardial infarction and utilized the CXCR2 receptor inhibitor navarixin (Nav) to reduce neutrophil recruitment after MI. Results: We observed that Nav improved cardiac function, reduced myocardial damage, reduced neutrophil infiltration, reduced inflammatory factor expression and improved cardiac fibrosis in mice. Through transcriptomic analysis, we found that Nav affects signaling pathways such as the innate immune response and the chemokine signaling pathway, thereby decreasing the inflammatory response by reducing neutrophil chemotaxis. Discussion: This study provides new insights for the use of CXCR2 inhibitors as new therapeutic options for myocardial infarction in the future.
Project description:In this study, we used a cardiac-specific, inducible expression system to activate YAP in adult mouse heart. Activation of YAP in adult heart promoted cardiomyocyte proliferation and did not deleteriously affect heart function. Furthermore, YAP activation after myocardial infarction (MI) preserved heart function and reduced infarct size. Using adeno-associated virus subtype 9 (AAV9) as a delivery vector, we expressed human YAP in the murine myocardium immediately after MI. We found that AAV9:hYAP significantly improved cardiac function and mouse survival. AAV9:hYAP did not exert its salutary effects by reducing cardiomyocyte apoptosis. Rather, we found that AAV9:hYAP stimulated adult cardiomyocyte proliferation. Gene expression profiling indicated that AAV9:hYAP stimulated cell cycle gene expression, enhanced TGFβ-signaling, and activated of components of the inflammatory response.Cardiac specific YAP activation after MI mitigated myocardial injury after MI, improved cardiac function and mouse survival. These findings suggest that therapeutic activation of hYAP or its downstream targets, potentially through AAV-mediated gene therapy, may be a strategy to improve outcome after MI. Three groups were involved in this study: sham group, AAV9:Luci+MI group and AAV9-YAP+MI group. Each group contained three biological replicates. The sham group had neither myocardial infarction nor AAV injection. The AAV9:Luci +MI(L for brief) group had myocardial infarction and injected with AAV9:Luic. The AAV9:hYAP+MI(YAP for brief) group had myocardial infarction and injected with AAV9:hYAP. 5 days after MI and AAV injection, the heart apexes were collected and the total RNA were isolated for microarray analysis.
Project description:Myocardial infarction (MI) contributes to cardiac mortality and morbidity. After myocardial infarction the innate immune response is pivotal in clearing of tissue debris as well as scar formation, but exaggerated cytokine and chemokine secretion with subsequent leukocyte infiltration also leads to further tissue damage. Post-translational regulation of cytokine / chemokine signaling occurs via ectodomain shedding through a disintegrin and metalloproteases (ADAMs). Here, we address the value of targeting a previously unknown ADAM10 / CX3CL1 axis in the regulation of neutrophil recruitment early after MI. We show that myocardial ADAM10 is distinctly upregulated in biopsies from patients with ischemia-driven cardiomyopathy and correlates with heart failure progression. Intriguingly, upon MI in mice, pharmacological treatment with the ADAM10 inhibitionor GI254023X as well as genetic cardiomycyte-specific ADAM10 deletion improves survival with markedly enhanced heart function and reduced scar size. Mechanistically, this is driven by abolished ADAM10-mediated CX3CL1 ectodomain shedding followed by diminished IL-1β-dependent inflammation, reduced neutrophil bone marrow egress as well as myocardial tissue infiltration. Genetic cardiomycyte-specific ADAM10 deletion confirmes the small-molecule data and leads to improved cardiac function and reduction in inflammatory markers after ischemic myocardial injury. Thus, our data shows a conceptual insight into how acute MI induces chemotactic signaling via ectodomain shedding in cardiomyocytes.
Project description:Ischemic heart disease remains the leading cause of mortality and morbidity worldwide despite improved possibilities in medical care. Alongside interventional therapies, such as coronary artery bypass grafting (CABG), adjuvant tissue-engineered and cell-based treatments can provide regenerative improvement. Unfortunately, most of these advanced approaches require multiple lengthy and costly preparation stages without in turn delivering significant clinical benefit.
Here, we investigated the effect of epicardial matrix patch-encased atrial appendage micrografts (AAMs) in a mouse model of myocardial infarction. The matrix-covered AAM patches salvaged the myocardium from infarction-induced functional tissue loss. Fibrosis was attenuated, and site-targeted proteomics revealed AAM patch-activated pathways for angiogenesis and cardiogenesis. The matrix component of the graft further supports functional myocardial recovery by ventricular unloading.
The composite epicardial matrix graft encasing AAM micrografts delivers effects desirable for adjuvant cardiac therapy preserving functional cardiac tissue and restricting fibrosis after myocardial infarction.
Project description:Heart failure (HF) is a leading cause of morbidity and mortality. As adult cardiomyocytes (CMs) have little regenerative capacity, after myocardial infarction (MI), resident cardiac fibroblasts (CFs) synthesize extracellular matrix to form scar tissues, resulting in myocardial remodeling and HF. Thus, both cardiac regeneration and fibrosis are therapeutic targets for chronic MI. We previously reported that fibroblasts were directly reprogrammed into induced CMs (iCMs) by overexpression of cardiogenic transcription factors in vitro and in vivo in acute MI. Here we show that in vivo cardiac reprogramming generated iCMs from resident CFs, improved cardiac function, and reversed fibrosis in chronic MI using a novel transgenic mouse system. Single-cell transcriptome analysis revealed that cardiac reprogramming shifted matrix-producing CFs, matrifibrocytes, to a quiescent state and changed the interstitial cell landscape, suppressing fibrotic and inflammatory signatures and activating angiogenic program. Thus, in vivo cardiac reprogramming may be a promising approach for chronic HF.
Project description:Heart failure (HF) is a leading cause of morbidity and mortality. As adult cardiomyocytes (CMs) have little regenerative capacity, after myocardial infarction (MI), resident cardiac fibroblasts (CFs) synthesize extracellular matrix to form scar tissues, resulting in myocardial remodeling and HF. Thus, both cardiac regeneration and fibrosis are therapeutic targets for chronic MI. We previously reported that fibroblasts were directly reprogrammed into induced CMs (iCMs) by overexpression of cardiogenic transcription factors in acute and chronic MI. Here we show that in vivo cardiac reprogramming improved cardiac function, and reversed cardiac remodeling in chronic MI using a novel transgenic mouse system. Transcriptome analysis revealed that in vivo cardiac reprogramming suppressed signs of fibrosis and inflammation. Thus, in vivo cardiac reprogramming may be a promising approach for chronic HF.
Project description:Cellular oxidative stress resistance and bioactivities showed great significance for long-term survival and cardiac regeneration. Cardiosphere-derived cells (CDCs) are favorable cell sources for myocardial infarction (MI) therapy, but effective culture systems for CDC spheroids, cardiospheres (CSps), cultivation and cell function enhancement are not well established. Here, a liquid crystal substrate, octyl hydroxypropyl cellulose ester (OPC), was developed for CSps production and preconditioning. With unique surface properties and mechanical responsiveness, significantly more size-controllable CSps were acquired using OPC substrate, and the OPC-CSps showed improved cell bioactivities and oxidative stress resistance under the stimulation of mechanical-induced pyroptosis. RNA sequencing and metabolism analysis demonstrated the increased metabolic level and improved mitochondrial function of OPC-CSps. In a rat MI model, OPC-CSps significantly improved long-term cardiac function, promoted angiogenesis, and reduced cardiac remodeling in the 3-month observation. Collectively, this study provides a promising and effective system for preparing massive functional CSps for myocardial infarction therapy.
Project description:Acute myocardial infarction (AMI) induces blood leukocytosis, which correlates inversely with patient survival. The molecular mechanisms leading to leukocytosis, and recruitment to the infarcted heart, remain poorly understood. Using an AMI mouse model, gasdermin D (GSDMD) was identified in activated neutrophils early in AMI. We demonstrated that GSDMD is required for enhanced recruitment of neutrophils and monocytes to the infarcted heart. Loss of GSDMD resulted in reduced release of IL-1β from neutrophils and reduced recruitment of neutrophils and monocytes to the infarcted heart. Knockout of GSDMD in mice significantly reduced infarct size, improved cardiac function and increased survival post AMI. Through a series of bone marrow transplantation studies and leukocytes depletion experiments, we further demonstrated that excessive bone marrow derived and GSDMD-dependent neutrophil recruitment, contributes to the detrimental immunopathology after AMI. Pharmacological inhibition of GSDMD also conferred cardioprotection post AMI, through reduction of scar size and enhancement of heart function. Our study provides new mechanistic insights into molecular regulation of neutrophil generation and recruitment after AMI, and supports GSDMD as a new target for improved ventricular remodeling and reduced heart failure after AMI.
Project description:Heart failure (HF) is a leading cause of morbidity and mortality. As adult cardiomyocytes (CMs) have little regenerative capacity, after myocardial infarction (MI), resident cardiac fibroblasts (CFs) synthesize extracellular matrix to form scar tissues, resulting in myocardial remodeling and HF. Thus, both cardiac regeneration and fibrosis are therapeutic targets for chronic MI. We previously reported that fibroblasts were directly reprogrammed into induced CMs (iCMs) by overexpression of cardiogenic transcription factors in vitro and in vivo in acute MI. Here we show that in vivo cardiac reprogramming generated iCMs from resident CFs, improved cardiac function, and reversed fibrosis in chronic MI using a novel transgenic mouse system. Transcriptome analysis revealed that in vivo cardiac reprogramming altered the interstitial cell landscape, suppressed signs of fibrosis and inflammation, and activated the angiogenic program. Thus, in vivo cardiac reprogramming may be a promising approach for chronic HF.
Project description:Navarixin alleviates cardiac remodeling after myocardial infarction by decreasing neutrophil infiltration and the inflammatory response
Project description:We developed and optimized a new electroporation protocol for CRISPR-Cas9 gene editing. This protocol achieved up to 68% success rate, when applied to isolated hMSCs from the heart and epicardial fat of patients with ischemic heart disease. While cell editing resulted lowered TLR4 expression in hMSCs, it did not affect classical markers of hMSCs and proliferation rate. Advanced protein mass spectrometry analysis revealed that edited cells secreted fewer proteins involved in inflammation and in extracellular matrix organization. The immunomodulatory effect of TLR4 editing was apparent in both free and EV-encapsulated proteins. Furthermore, edited cells expressed less NF-ƙB and secreted lower amounts of extracellular vesicles, pro-inflammatory and pro-fibrotic cytokines than unedited hMSCs. Cell therapy with edited and unedited hMSCs improved survival, left ventricular (LV) remodeling, and cardiac function after myocardial infarction (MI) in mice. Postmortem histologic analysis revealed clusters of edited cells that survived in the scar tissue 28 days after MI. Morphometric analysis showed that implantation of edited cells increased the area of myocardial islands in the scar tissue, reduced the occurrence of transmural scar, increased scar thickness, and markedly decreased expansion index, compared with unedited cells or saline.