Abrogation of CC Chemokine Receptor 9 Ameliorates Ventricular Electrical Remodeling in Mice After Myocardial Infarction

Cerebrospinal Fluid CCL25 as a Biomarker for Alzheimer's Disease: Associations with Pathology, Neurodegeneration, and Cognitive Decline

Neuroinflammation plays a crucial role in Alzheimer's disease (AD) pathogenesis. We investigated the relationship between cerebrospinal fluid (CSF) C-C chemokine ligand 25 (CCL25), an inflammatory regulator, and AD pathology and progression. We analyzed data on CSF CCL25, AD biomarkers (CSF β-amyloid [Aβ]42, phosphorylated tau [pTau]181, amyloid positron emission tomography [PET]), postmortem neuropathology, magnetic resonance imaging-based neurodegeneration, and cognitive function from 703 participants in the Alzheimer's Disease Neuroimaging Initiative cohort. We found that elevated CSF CCL25 levels were associated with cognitive impairment, abnormal Aβ and tau pathology, greater brain atrophy, and worse cognitive performance (all P < 0.05). Notably, CSF CCL25 exhibited nonlinear relationships with Aβ and tau pathology, reaching a plateau as AD pathology increased. CSF CCL25 showed acceptable diagnostic accuracy in distinguishing amyloid-positive/negative (A ±) and tau-positive/negative (T ±) participants (area under the curve [AUC] = 0.71-0.77) and autopsy-confirmed AD cases (AUC = 0.77), with optimal performance in differentiating A + T + from A-T- participants (AUC = 0.82-0.85 with age and sex adjustment). Longitudinally, higher baseline CSF CCL25 predicted accelerated amyloid accumulation, hippocampal atrophy, and cognitive decline. Mediation analyses revealed that CCL25 partially mediated associations between Aβ pathology and tau pathology (mediating effect: 54.5%), neurodegeneration (18.2%), and cognitive decline (7.4%). Among 37 CSF CCL and CXCL chemokines examined, 28 were associated with at least one AD-related outcome, with CCL25 demonstrating the strongest associations overall. These findings suggest that CSF CCL25 is involved in early AD pathological progression and may serve as an inflammatory biomarker for diagnosis and monitoring of disease progression in AD.

CCL25 contributes to the pathogenesis of D-Gal/LPS-induced acute liver failure

BACKGROUND AND AIM

Acute liver failure (ALF) is a fatal clinical syndrome of severe hepatic dysfunction. Chemokines promote liver diseases by recruiting and activating immune cells. We aimed to investigate the role of C-C chemokine ligand 25 (CCL25) in ALF.

METHODS

An ALF mouse model induced by D-galactosamine/lipopolysaccharide was evaluated through liver hematoxylin and eosin staining and serum transaminase and cytokine measurement. CCL25 expression in serum was analyzed by ELISA and in liver by immunohistochemical staining and western blot. C-C chemokine receptor 9 (CCR9)-expressing cells in the liver were identified by immunofluorescence staining. The effects of anti-CCL25 on ALF were evaluated in vivo. Cytokine expression and migration of CCL25-stimulated RAW264.7 macrophages were studied. We also investigated the role of anti-CCL25 and BMS-345541, an NF-κB signaling inhibitor, in vitro. NF-κB activation was assessed via western blot, and p65 nuclear translocation was detected using cellular immunofluorescence.

RESULTS

ALF mice showed severe histological damage and high serum levels of aminotransferase and inflammatory cytokines. Elevated CCL25 and NF-κB activation was observed in vivo. CCR9 was expressed on macrophages in ALF mouse liver. ALF was suppressed after anti-CCL25 treatment, with significant NF-κB inhibition. In vitro, CCL25 induced strong migration and cytokine release in RAW264.7 macrophages, which were eliminated by anti-CCL25 and BMS-345541. Furthermore, the NF-κB activation and p65 nuclear translocation induced by CCL25 were also inhibited by anti-CCL25 and BMS-345541.

CONCLUSION

CCL25 contributes to ALF development by inducing macrophage-mediated inflammation via activation of the NF-κB signaling.

Pleiotropic role of CCR9/CCL25 signaling in adriamycin-induced cardiomyopathy

INTRODUCTION

Adriamycin (ADR)-induced cardiomyopathy is a common problem in many cancer survivors. Recently, specific chemokine receptors have garnered interest as therapeutic targets in cardiovascular diseases.

OBJECTIVES

This study aim to report the role of C-C chemokine receptor 9 (CCR9)/C-C chemokine ligand 25 (CCL25) and its therapeutic potential in ADR-induced cardiomyopathy.

METHODS

Functional gene knockout and overexpression mouse models were utilized to investigate the role of CCR9 against ADR-induced cardiomyopathy. Transcriptome sequencing was also performed to identify the downstream molecular mechanisms of CCR9.

RESULTS

This study revealed that CCR9 and CCL25 levels were increased in mice and HL-1 cells injured by ADR, consistent with the results of patients with heart failure. Both in vivo and in vitro, CCR9 overexpression overtly aggravated cardiac dysfunction, accompanied by decreased AMPK activity and increased mitochondrial dysfunction, fibrosis, oxidative stress, and apoptosis. However, the cardiac harmful effects of ADR were reserved by CCR9 knockdown, as well as CCR9 overexpression aggravated cardiotoxicity were reserved by AMPK agonist GSK621. By constructing different domain-missing CCR9 mutants, we suspected that the △4 region of CCR9 is important for AMPK activity. Furthermore, transcriptome sequencing  further illustrated the mechanism of CCR9 overexpression aggravated ADR-induced cardiotoxicity, which was associated with CYP1A1. Finally, lithospermic acid (LA) was screened and alleviated ADR-induced cardiotoxicity through regulation of CCR9/CCL25-AMPK signaling, bolstering CCR9-targeted potential clinical application.

CONCLUSION

These findings present a promising target and drug for treating chemotherapy-induced cardiotoxicity.

Role of angiotensin converting enzyme in pathogenesis associated with immunity in cardiovascular diseases

Angiotensin converting enzyme (ACE) is not only a critical component in the renin-angiotensin system (RAS), but also suggested as an important mediator for immune response and activity, such as immune cell mobilization, metabolism, biogenesis of immunoregulatory molecules, etc. The chronic duration of cardiovascular diseases (CVD) has been increasingly considered to be triggered by uncontrolled pathologic immune reactions from myeloid cells and lymphocytes. Considering the potential anti-inflammatory effect of the traditional antihypertensive ACE inhibitor (ACEi), we attempt to elucidate whether ACE and its catalytically relevant substances as well as signaling pathways play a role in the immunity-related pathogenesis of common CVD, such as arterial hypertension, atherosclerosis and arrythmias. ACEi was also reported to benefit the prognoses of COVID-19-positive patients with CVD, and COVID-19 disease with preexisting CVD or subsequent cardiovascular damage is featured by a significant influx of immune cells and proinflammatory molecules, suggesting that ACE may also participate in COVID-19 induced cardiovascular injury, because COVID-19 disease basically triggers an overactive pathologic immune response. Hopefully, the ACE inhibition and manipulation of those associated bioactive signals could supplement the current medicinal management of various CVD and bring greater benefit to patients' cardiovascular health.

Unraveling the neuroimmune interface in chronic pain-the association between cytokines in the cerebrospinal fluid and pain in patients with lumbar disk herniation or degenerative disk disease

ABSTRACT

Recent evidence highlights the importance of the neuroimmune interface, including periphery-to-central nervous system (CNS) neuroimmune crosstalk, in chronic pain. Although neuroinflammatory processes have been implicated in central sensitization for a long time, their potential neuroprotective and analgesic effects remain relatively elusive. We have explored the relationships between cytokine expression and symptom severity, and candidates for periphery-to-CNS crosstalk. Patients with degenerative disk disease (DDD) (nociceptive pain) or patients with lumbar disk herniation (LDH) with radiculopathy (predominantly neuropathic pain) completed questionnaires regarding pain and functional disability, underwent quantitative sensory testing, and provided blood and cerebrospinal fluid (CSF) samples. Proximity extension assay (PEA) was used to measure the levels of 92 inflammatory proteins in the CSF and serum from a total of 160 patients and controls, and CSF/serum albumin quotients was calculated for patients with DDD and patients with LDH. We found signs of neuroimmune activation, in the absence of systemic inflammation. Regarding periphery-to-CNS neuroimmune crosstalk, there were significant associations between several cytokines and albumin quotient, despite the latter being primarily at subclinical levels. The cytokines CCL11, CD5, IL8, and MMP-10 were elevated in the CSF, had positive correlations between CSF and serum levels, and associated in a nonlinear manner with back, but not leg, pain intensity in the LDH, but not the DDD, group. In conclusion, we found evidence for neuroimmune activation in the CNS of both patient groups in the absence of systemic inflammation and signs of a communication between CSF and serum. Complex and disease-specific associations were found between cytokines in CSF and back pain intensity.

High-Fat Diet Augments Myocardial Inflammation and Cardiac Dysfunction in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a familial heart disease characterized by cardiac dysfunction, arrhythmias, and myocardial inflammation. Exercise and stress can influence the disease's progression. Thus, an investigation of whether a high-fat diet (HFD) contributes to ACM pathogenesis is warranted. In a robust ACM mouse model, 8-week-old Desmoglein-2 mutant (Dsg2mut/mut) mice were fed either an HFD or rodent chow for 8 weeks. Chow-fed wildtype (WT) mice served as controls. Echo- and electrocardiography images pre- and post-dietary intervention were obtained, and the lipid burden, inflammatory markers, and myocardial fibrosis were assessed at the study endpoint. HFD-fed Dsg2mut/mut mice showed numerous P-wave perturbations, reduced R-amplitude, left ventricle (LV) remodeling, and reduced ejection fraction (%LVEF). Notable elevations in plasma high-density lipoprotein (HDL) were observed, which correlated with the %LVEF. The myocardial inflammatory adipokines, adiponectin (AdipoQ) and fibroblast growth factor-1, were substantially elevated in HFD-fed Dsg2mut/mut mice, albeit no compounding effect was observed in cardiac fibrosis. The HFD not only potentiated cardiac dysfunction but additionally promoted adverse cardiac remodeling. Further investigation is warranted, particularly given elevated AdipoQ levels and the positive correlation of HDL with the %LVEF, which may suggest a protective effect. Altogether, the HFD worsened some, but not all, disease phenotypes in Dsg2mut/mut mice. Notwithstanding, diet may be a modifiable environmental factor in ACM disease progression.

Post translational modifications of connexin 43 in ventricular arrhythmias after myocardial infarction

Ventricular arrhythmias are the leading cause of sudden cardiac death in patients after myocardial infarction (MI). Connexin43 (Cx43) is the most important gap junction channel-forming protein in cardiomyocytes. Dysfunction of Cx43 contributes to impaired myocardial conduction and the development of ventricular arrhythmias. Following an MI, Cx43 undergoes structural remodeling, including expression abnormalities, and redistribution. These alterations detrimentally affect intercellular communication and electrical conduction within the myocardium, thereby increasing the susceptibility to post-infarction ventricular arrhythmias. Emerging evidence suggests that post-translational modifications play essential roles in Cx43 regulation after MI. Therefore, Cx43-targeted management has the potential to be a promising protective strategy for the prevention and treatment of post infarction ventricular arrhythmias. In this article, we primarily reviewed the regulatory mechanisms of Cx43 mediated post-translational modifications on post-infarction ventricular arrhythmias. Furthermore, Cx43-targeted therapy have also been discussed, providing insights into an innovative treatment strategy for ventricular arrhythmias after MI.

Vericiguat alleviates ventricular remodeling and arrhythmias in mouse models of myocardial infarction via CaMKII signaling

AIMS

Maladaptive ventricular remodeling is a major cause of ventricular arrhythmias following myocardial infarction (MI) and adversely impacts the quality of life of affected patients. Vericiguat is a new soluble guanylate cyclase (sGC) activator with cardioprotective properties. However, its effects on MI-induced ventricular remodeling and arrhythmias are not fully comprehended; hence, our research evaluated the effect of vericiguat on mice post-MI.

MATERIALS AND METHODS

Mice were divided into four treatment groups: Sham, Sham+Veri, MI, and MI + Veri. For the MI groups and MI + Veri groups, the left anterior descending (LAD) coronary artery was occluded to induce MI. Conversely, the Sham group underwent mock surgery. Vericiguat was administered orally daily for 28 days to the Sham+Veri and MI + Veri groups. Additionally, H9c2 cells were cultured for further mechanistic studies. Assessment methods included echocardiography, pathological analysis, electrophysiological analysis, and Western blotting.

KEY FINDINGS

Vericiguat reduced cardiac dysfunction and infarct size after MI. It also mitigated MI-induced left ventricular fibrosis and cardiomyocyte apoptosis. Vericiguat normalized the expression of ion channel proteins (Kv4.3, Kv4.2, Kv2.1, Kv1.5, Kv7.1, KCNH2, Cav1.2) and the gap junction protein connexin 43, reducing the susceptibility to ventricular arrhythmia. Vericiguat significantly inhibited MI-induced calcium/calmodulin-dependent protein kinase II (CaMKII) pathway activation in mice.

SIGNIFICANCE

Vericiguat alleviated MI-induced left ventricular adverse remodeling and arrhythmias through modulation of the CamkII signaling pathway.

Advances in basic and translational research in atrial fibrillation

Atrial fibrillation (AF) is a very common cardiac arrhythmia with an estimated prevalence of 33.5 million patients globally. It is associated with an increased risk of death, stroke and peripheral embolism. Although genetic studies have identified a growing number of genes associated with AF, the definitive impact of these genetic findings is yet to be established. Several mechanisms, including electrical, structural and neural remodelling of atrial tissue, have been proposed to contribute to the development of AF. Despite over a century of exploration, the molecular and cellular mechanisms underlying AF have not been fully established. Current antiarrhythmic drugs are associated with a significant rate of adverse events and management of AF using ablation is not optimal, especially in cases of persistent AF. This review discusses recent advances in our understanding and management of AF, including new concepts of epidemiology, genetics and pathophysiological mechanisms. We review the current status of antiarrhythmic drug therapy for AF, new potential agents, as well as mechanism-based AF ablation. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

Transcriptomic and Metabolomic Changes Reveal the Immunomodulatory Function of Casein Phosphopeptide-Selenium Chelate in Beagle Dogs

Casein phosphopeptide-selenium chelate (CPP-Se) is an organic compound produced by the chelation of casein phosphopeptide with selenium. This compound showed the ability to modulate canine immune response in our previous study; but its effect on the peripheral blood transcriptome and serum metabolome was unknown. This study aims to reveal the potential mechanism behind the immunomodulatory function of CPP-Se. We have identified 341 differentially expressed genes (DEGs) in CPP-Se groups as compared to the control group which comprised 110 up-regulated and 231 down-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis found that DEGs were mainly involved in immune-related signaling pathways. Moreover, the immune-related DEGs and hub genes were identified. Similarly, metabolomics identified 53 differentially expressed metabolites (DEMs) in the CPP-Se group, of which 17 were up-regulated and 36 were down-regulated. The pathways mainly enriched by DEMs were primary bile acid biosynthesis, tryptophan metabolism, and other amino acids metabolic pathways. Combined analysis of transcriptomic and metabolomic data showed that the DEGs and DEMs were commonly enriched in fatty acid biosynthesis, pyrimidine metabolism, glutathione metabolism, and glycerolipid metabolic pathways. Taken together, our findings provided a theoretical basis for further understanding of the immunomodulatory function of CPP-Se as well as a scientific reference for the future use of CPP-Se in pet foods as a dietary supplement to modulate the immunity.

Targeting neuro-immune systems to achieve cardiac tissue repair following myocardial infarction: A review of therapeutic approaches from in-vivo preclinical to clinical studies

Myocardial healing following myocardial infarction (MI) toward either functional tissue repair or excessive scarring/heart failure, may depend on a complex interplay between nervous and immune system responses, myocardial ischemia/reperfusion injury factors, as well as genetic and epidemiological factors. Hence, enhancing cardiac repair post MI may require a more patient-specific approach targeting this complex interplay and not just the heart, bearing in mind that the dysregulation or modulation of just one of these systems or some of their mechanisms may determine the outcome either toward functional repair or toward heart failure. In this review we have elected to focus on existing preclinical and clinical in-vivo studies aimed at testing novel therapeutic approaches targeting the nervous and immune systems to trigger myocardial healing toward functional tissue repair. To this end, we have only selected clinical and preclinical in-vivo studies reporting on novel treatments targeting neuro-immune systems to ultimately treat MI. Next, we have grouped and reported treatments under each neuro-immune system. Finally, for each treatment we have assessed and reported the results of each clinical/preclinical study and then discussed their results collectively. This structured approach has been followed for each treatment discussed. To keep this review focused, we have deliberately omitted to cover other important and related research areas such as myocardial ischemia/reperfusion injury, cell and gene therapies as well as any ex-vivo and in-vitro studies. The review indicates that some of the treatments targeting the neuro-immune/inflammatory systems appear to induce beneficial effects remotely on the healing heart post MI, warranting further validation. These remote effects on the heart also indicates the presence of an overarching synergic response occurring across the nervous and immune systems in response to acute MI, which appear to influence cardiac tissue repair in different ways depending on age and timing of treatment delivery following MI. The cumulative evidence arising from this review allows also to make informed considerations on safe as opposed to detrimental treatments, and within the safe treatments to ascertain those associated with conflicting or supporting preclinical data, and those warranting further validation.

Inhibitory Effects of Nobiletin on Voltage-Gated Na+ Channel in Rat Ventricular Myocytes Based on Electrophysiological Analysis and Molecular Docking Method

Nobiletin (NOB) has attracted much attention owing to its outstanding bioactivities. This study aimed to investigate its anti-arrhythmic effect through electrophysiological and molecular docking studies. We assessed the anti-arrhythmic effects of NOB using aconitine-induced ventricular arrhythmia in a rat model and the electrophysiological effects of NOB on rat cardiomyocytes utilizing whole-cell patch-clamp techniques. Moreover, we investigated the binding characters of NOB with rNav1.5, rNav1.5/QQQ, and hNa_V1.5 via docking analysis, comparing them with amiodarone and aconitine. NOB pretreatment delayed susceptibility to ventricular premature and ventricular tachycardia and decreased the incidence of fatal ventricular fibrillation. Whole-cell patch-clamp assays demonstrated that the peak current density of the voltage-gated Na⁺ channel current was reversibly reduced by NOB in a concentration-dependent manner. The steady-state activation and recovery curves were shifted in the positive direction along the voltage axis, and the steady-state inactivation curve was shifted in the negative direction along the voltage axis, as shown by gating kinetics. The molecular docking study showed NOB formed a π-π stacking interaction with rNav1.5 and rNav1.5/QQQ upon Phe-1762, which is the homolog to Phe-1760 in hNa_V1.5 and plays an important role in antiarrhythmic action This study reveals that NOB may act as a class I sodium channel anti-arrhythmia agent.

The Effects of Hypoxic Preconditioned Murine Mesenchymal Stem Cells on Post-Infarct Arrhythmias in the Mouse Model

Ventricular arrhythmias associated with myocardial infarction (MI) have a significant impact on mortality in patients following heart attack. Therefore, targeted reduction of arrhythmia represents a therapeutic approach for the prevention and treatment of severe events after infarction. Recent research transplanting mesenchymal stem cells (MSC) showed their potential in MI therapy. Our study aimed to investigate the effects of MSC injection on post-infarction arrhythmia. We used our murine double infarction model, which we previously established, to more closely mimic the clinical situation and intramyocardially injected hypoxic pre-conditioned murine MSC to the infarction border. Thereafter, various types of arrhythmias were recorded and analyzed. We observed a homogenous distribution of all types of arrhythmias after the first infarction, without any significant differences between the groups. Yet, MSC therapy after double infarction led to a highly significant reduction in simple and complex arrhythmias. Moreover, RNA-sequencing of samples from stem cell treated mice after re-infarction demonstrated a significant decline in most arrhythmias with reduced inflammatory pathways. Additionally, following stem-cell therapy we found numerous highly expressed genes to be either linked to lowering the risk of heart failure, cardiomyopathy or sudden cardiac death. Moreover, genes known to be associated with arrhythmogenesis and key mutations underlying arrhythmias were downregulated. In summary, our stem-cell therapy led to a reduction in cardiac arrhythmias after MI and showed a downregulation of already established inflammatory pathways. Furthermore, our study reveals gene regulation pathways that have a potentially direct influence on arrhythmogenesis after myocardial infarction.

Investigating underlying human immunity genes, implicated diseases and their relationship to COVID-19

Aim: A human immunogenetics variation study was conducted in samples collected from diverse COVID-19 populations. Materials & methods: Whole-genome and whole-exome sequencing (WGS/WES), data processing, analysis and visualization pipeline were applied to identify variants associated with genes of interest. Results: A total of 2886 mutations were found across the entire set of 13 genomes. Functional annotation of the gene variants revealed mutation type and protein change. Many variants were found to be biologically implicated in COVID-19. The involvement of these genes was also found in multiple other diseases. Conclusion: The analysis determined that ACE2, TMPRSS4, TMPRSS2, SLC6A20 and FYCOI had functional implications and TMPRSS4 was the gene most altered in virally infected patients.

The quest to establish an understanding of the genetics underlying COVID-19 is a central focus of life sciences today. COVID-19 is triggered by SARS-CoV-2, a single-stranded RNA respiratory virus. Several clinical-genomics studies have emerged positing different human gene mutations occurring due to COVID-19. A global analysis of these genes was conducted targeting major components of the immune system to identify possible variations likely to be involved in COVID-19 predisposition. Gene-variant analysis was performed on whole-genome sequencing samples collected from diverse populations. ACE2, TMPRSS4, TMPRSS2, SLC6A20 and FYCOI were found to have functional implications and TMPRSS4 may have a role in the severity of clinical manifestations of COVID-19.