Topiramate modulates post-infarction inflammation primarily by targeting monocytes or macrophages

Noninvasive Imaging of Immune Cell Activity in Myocardial Infarction Phases Using 99mTc-HYNIC-mAbKv1.3 SPECT/CT

Acute myocardial infarction (MI) remains a leading cause of mortality worldwide, with inflammatory and reparative phases playing critical roles in disease progression. Currently, there is a pressing need for in vivo imaging techniques to monitor immune cell infiltration and inflammation activity during these phases. We developed a novel probe, 99mTc-HYNIC-mAbKv1.3, utilizing a monoclonal antibody that targets the voltage-gated potassium channel 1.3 (Kv1.3). This probe enables in vivo visualization of immune cells that express high levels of Kv1.3 proteins. In a murine MI model, SPECT/CT imaging with 99mTc-HYNIC-mAbKv1.3 demonstrated specific uptake in an infarcted myocardium during the inflammatory phase, reflecting immune cell infiltration and activity. During the reparative phase, the probe exhibited prolonged retention in the infarcted area, suggestive of ongoing immune cell proliferation. Immunofluorescence staining confirmed the probe's specificity. Biodistribution analysis indicated preferential accumulation in the infarcted myocardium and liver, consistent with SPECT/CT findings. Combined with [18F]FDG PET/CT, these modalities provided comprehensive insights into myocardial viability and inflammation. This study highlights the potential of 99mTc-HYNIC-mAbKv1.3 SPECT/CT as a noninvasive tool to monitor immune cell activity in different phases of MI, guide therapeutic interventions, and predict disease progression. Further translational studies are warranted to explore its clinical applicability in cardiac pathologies.

Myeloid Cells in Myocardial Ischemic Injury: The Role of the Macrophage Migration Inhibitory Factor

Ischemic heart disease, manifesting as myocardial infarction (MI), remains the leading cause of death in the western world. Both ischemia and reperfusion (I/R) cause myocardial injury and result in cardiac inflammatory responses. This sterile inflammation in the myocardium consists of multiple phases, involving cell death, tissue remodeling, healing, and scar formation, modulated by various cytokines, including the macrophage migration inhibitory factor (MIF). Meanwhile, different immune cells participate in these phases, with myeloid cells acting as first responders. They migrate to the injured myocardium and regulate the initial phase of inflammation. The MIF modulates the acute inflammatory response by affecting the metabolic profile and activity of myeloid cells. This review summarizes the role of the MIF in regulating myeloid cell subsets in MI and I/R injury and discusses emerging evidence of metabolism-directed cellular inflammatory responses. Based on the multifaceted role of the MIF affecting myeloid cells in MI or I/R, the MIF can be a therapeutic target to achieve metabolic balance under pathology and alleviate inflammation in the heart.

Macrophage heterogeneity in myocardial infarction: Evolution and implications for diverse therapeutic approaches

Given the extensive participation of myeloid cells (especially monocytes and macrophages) in both inflammation and resolution phases post-myocardial infarction (MI) owing to their biphasic role, these cells are considered as crucial players in the disease pathogenesis. Multiple studies have agreed on the significant contribution of macrophage polarization theory (M2 vs. M1) while determining the underlying reasons behind the observed biphasic effects; nevertheless, this simplistic classification attracts severe drawbacks. The advent of multiple advanced technologies based on OMICS platforms facilitated a successful path to explore comprehensive cellular signatures that could expedite our understanding of macrophage heterogeneity and plasticity. While providing an overall basis behind the MI disease pathogenesis, this review delves into the literature to discuss the current knowledge on multiple macrophage clusters, including the future directions in this research arena. In the end, our focus will be on outlining the possible therapeutic implications based on the emerging observations.

Association of systemic inflammatory response index with ST segment elevation myocardial infarction and degree of coronary stenosis: a cross-sectional study

BACKGROUND

Systemic Inflammatory Response Index (SIRI), a composite inflammatory marker encompassing neutrophils, monocytes, and lymphocytes, has been recognized as a reliable marker of systemic inflammation. This article undertakes an analysis of clinical data from ST-segment Elevation Myocardial Infarction (STEMI) patients, aiming to comprehensively assess the relationship between SIRI, STEMI, and the degree of coronary stenosis.

METHODS

The study involved 1809 patients diagnosed with STEMI between the years 2020 and 2023. Univariate and multivariate logistic regression analyses were conducted to evaluate the risk factors for STEMI. Receiver operating characteristic (ROC) curves were generated to determine the predictive power of SIRI and neutrophil-to-lymphocyte ratio (NLR). Spearman correlation analysis was performed to assess the correlation between SIRI, NLR, and the Gensini score (GS).

RESULTS

Multivariate logistic regression analysis showed that the SIRI was the independent risk factor for STEMI (adjusted odds ratio (OR) in the highest quartile = 24.96, 95% confidence interval (CI) = 15.32-40.66, P < 0.001). In addition, there is a high correlation between SIRI and GS (β:28.54, 95% CI: 24.63-32.46, P < 0.001). The ROC curve analysis was performed to evaluate the predictive ability of SIRI and NLR for STEMI patients. The area under the curve (AUC) for SIRI was 0.789. The AUC for NLR was 0.754. Regarding the prediction of STEMI in different gender groups, the AUC for SIRI in the male group was 0.771. The AUC for SIRI in the female group was 0.807. Spearman correlation analysis showed that SIRI exhibited a stronger correlation with GS, while NLR was lower (SIRI: r = 0.350, P < 0.001) (NLR: r = 0.313, P < 0.001).

CONCLUSION

The study reveals a strong correlation between the SIRI and STEMI as well as the degree of coronary artery stenosis. In comparison to NLR, SIRI shows potential in predicting acute myocardial infarction and the severity of coronary artery stenosis. Additionally, SIRI exhibits a stronger predictive capability for female STEMI patients compared to males.

IL-38 attenuates myocardial ischemia-reperfusion injury by inhibiting macrophage inflammation

BACKGROUND

Reperfusion therapy is the most effective approach to resolve coronary occlusion, but myocardial injury caused by excessive inflammation during myocardial ischemia-reperfusion will also pose a new threat to health. Our prior study revealed the expression pattern of interleukin-38 (IL-38) in the peripheral blood serum of patients with ischemic cardiomyopathy and the role of IL-38 in acute myocardial infarction in mice. However, its role and potential mechanisms in myocardial ischemia/reperfusion injury (MIRI) remain to be determined.

METHODS AND RESULTS

The left anterior descending artery of C57BL/6 mice was transiently ligated to induce the MIRI model. We found that MIRI induced the expression of endogenous IL-38, which was mainly produced by locally infiltrating macrophages. Overexpression of IL-38 in C57BL/6 mice attenuated inflammatory injury and decreased myocardial apoptosis after myocardial ischemia-reperfusion. Furthermore, IL-38 inhibited lipopolysaccharide-induced macrophage inflammation in vitro. Cardiomyocytes cocultured with the supernatant of IL-38- and troponin I-treated macrophages showed a lower rate of apoptosis than controls.

CONCLUSIONS

IL-38 attenuates MIRI by inhibiting macrophage inflammation. This inhibitory effect may be partially achieved by inhibiting the activation of NOD-like receptor pyrin domain-related protein 3 inflammasome, resulting in decreased expression of inflammatory factors and reduced cardiomyocyte apoptosis.

sFgl2-Treg Positive Feedback Pathway Protects against Atherosclerosis

Soluble fibrinogen-like protein 2 (sFgl2), a novel effector of regulatory T cells (Tregs), has been demonstrated to have potent immunosuppressive functions. Multiple studies indicate that Tregs could exert important atheroprotective effects, but their numbers gradually decrease during atherogenesis. The receptor of sFgl2 can be expressed on Treg precursor cells, while the role of sFgl2 on Treg differentiation and atherosclerosis progression remains unclear. Firstly, we detected that the sFgl2 was decreased in humans and mice with atherosclerotic diseases and was especially lower in their vulnerable plaques. Then, we used both Adeno-associated virus-sFgl2 (AAV-sFgl2)-injected ApoE^-/- mice, which is systemic overexpression of sFgl2, and sFgl2^TgApoE^-/- bone marrow cells (BMC)-transplanted ApoE^-/- mice, which is almost immune-system-specific overexpression of sFgl2, to explore the role of sFgl2 in atherosclerosis. Our experiment data showed that AAV-sFgl2 and BMT-sFgl2 could reduce atherosclerotic area and enhance plaque stability. Mechanistically, sFgl2 increases the abundance and immunosuppressive function of Tregs, which is partly mediated by binding to FcγRIIB receptors and phosphorylating Smad2/3. Collectively, sFgl2 has an atheroprotective effect that is mainly achieved by forming a positive feedback pathway with Treg. sFgl2 and Treg could synergistically protect against atherosclerosis.

Cardiac repair after myocardial infarction: A two-sided role of inflammation-mediated

Myocardial infarction is the leading cause of death and disability worldwide, and the development of new treatments can help reduce the size of myocardial infarction and prevent adverse cardiovascular events. Cardiac repair after myocardial infarction can effectively remove necrotic tissue, induce neovascularization, and ultimately replace granulation tissue. Cardiac inflammation is the primary determinant of whether beneficial cardiac repair occurs after myocardial infarction. Immune cells mediate inflammatory responses and play a dual role in injury and protection during cardiac repair. After myocardial infarction, genetic ablation or blocking of anti-inflammatory pathways is often harmful. However, enhancing endogenous anti-inflammatory pathways or blocking endogenous pro-inflammatory pathways may improve cardiac repair after myocardial infarction. A deficiency of neutrophils or monocytes does not improve overall cardiac function after myocardial infarction but worsens it and aggravates cardiac fibrosis. Several factors are critical in regulating inflammatory genes and immune cells' phenotypes, including DNA methylation, histone modifications, and non-coding RNAs. Therefore, strict control and timely suppression of the inflammatory response, finding a balance between inflammatory cells, preventing excessive tissue degradation, and avoiding infarct expansion can effectively reduce the occurrence of adverse cardiovascular events after myocardial infarction. This article reviews the involvement of neutrophils, monocytes, macrophages, and regulatory T cells in cardiac repair after myocardial infarction. After myocardial infarction, neutrophils are the first to be recruited to the damaged site to engulf necrotic cell debris and secrete chemokines that enhance monocyte recruitment. Monocytes then infiltrate the infarct site and differentiate into macrophages and they release proteases and cytokines that are harmful to surviving myocardial cells in the pre-infarct period. As time progresses, apoptotic neutrophils are cleared, the recruitment of anti-inflammatory monocyte subsets, the polarization of macrophages toward the repair phenotype, and infiltration of regulatory T cells, which secrete anti-inflammatory factors that stimulate angiogenesis and granulation tissue formation for cardiac repair. We also explored how epigenetic modifications regulate the phenotype of inflammatory genes and immune cells to promote cardiac repair after myocardial infarction. This paper also elucidates the roles of alarmin S100A8/A9, secreted frizzled-related protein 1, and podoplanin in the inflammatory response and cardiac repair after myocardial infarction.

Subthreshold splenic nerve stimulation prevents myocardial Ischemia-Reperfusion injury via neuroimmunomodulation of proinflammatory factor levels

OBJECTIVES

Clinical outcomes following myocardial ischemia-reperfusion (I/R) injury are strongly related to the intensity and duration of inflammation. The splenic nerve (SpN) is indispensable for the anti-inflammatory reflex. This study aimed to investigate whether splenic nerve stimulation (SpNS) plays a cardioprotective role in myocardial I/R injury and the potential underlying mechanism.

METHODS

Sprague-Dawley rats were randomly divided into four groups: sham group, I/R group, SpNS group, and I/R plus SpNS group. The highest SpNS intensity that did not influence heart rate was identified, and SpNS at this intensity was used as the subthreshold stimulus. Continuous subthreshold SpNS was applied for 1 h before ligation of the left coronary artery for 45 min. After 72 h of reperfusion, samples were collected for analysis.

RESULTS

SpN activity and splenic concentrations of cholinergic anti-inflammatory pathway (CAP)-related neurotransmitters were significantly increased by SpNS. The infarct size, oxidative stress, sympathetic tone, and the levels of proinflammatory cytokines, including TNF-α, IL-1β, and IL-6, were significantly reduced in rats subjected to subthreshold SpNS after myocardial I/R injury compared with those subjected to I/R injury alone.

CONCLUSIONS

Subthreshold SpNS ameliorates myocardial damage, the inflammatory response, and cardiac remodelling induced by myocardial I/R injury via neuroimmunomodulation of proinflammatory factor levels. SpNS is a potential therapeutic strategy for the treatment of myocardial I/R injury.

The protective effects of topiramate and spirulina against doxorubicin-induced cardiotoxicity in rats

Doxorubicin (DOX) is a widely used chemotherapy drug that can cause significant cardiotoxicity, limiting its clinical application. This study aimed to investigate the potential protective effects of topiramate (TPM) and spirulina (SP), either alone or in combination, in preventing DOX-induced cardiotoxicity. Adult Sprague Dawley rats were divided into five groups, including a normal control group and groups receiving DOX alone, DOX with TPM, DOX with SP, or DOX with a combination of TPM and SP. Cardiotoxicity was induced by administering DOX intraperitoneally at a cumulative dose of 16 mg/kg over 4 weeks. TPM and/or SP administration started 1 week before DOX treatment and continued for 35 days. Body weight, serum markers of cardiac damage, oxidative stress and inflammatory parameters were assessed. Histopathological and immunohistochemical examinations were performed on cardiac tissues. Results showed that TPM and SP monotherapy led to significant improvements in serum levels of cardiac markers, decreased oxidative stress, reduced fibrosis-related growth factor levels, increased antioxidant levels, and improved histopathological features. SP demonstrated more prominent effects in comparison to TPM, and the combination of TPM and SP exhibited even more pronounced effects. In conclusion, TPM and SP, either alone or in combination, hold promise as therapeutic interventions for mitigating DOX-induced cardiotoxicity.

Topiramate Reprofiling for the Attenuation of Cadmium-Induced Testicular Impairment in Rats: Role of NLRP3 Inflammasome and AMPK/mTOR-Linked Autophagy

Topiramate, a promising drug classically used for the management of neurological disorders including epilepsy and migraine, has demonstrated marked anti-inflammatory and anti-apoptotic actions in murine models of cardiac post-infarction inflammation, wound healing, and gastric/intestinal injury. However, its potential impact on cadmium-induced testicular injury remains to be elucidated. Herein, the present study aimed to explore the effect of topiramate against cadmium-invoked testicular impairment with emphasis on the molecular mechanisms linked to inflammation, apoptosis, and autophagy. Herein, administration of topiramate (50 mg/kg/day, by gavage) continued for 60 days and the testes were examined by histology, immunohistochemistry, and biochemical assays. The present data demonstrated that serum testosterone, sperm count/abnormalities, relative testicular weight, and histopathological aberrations were improved by topiramate administration to cadmium-intoxicated rats. The rescue of testicular dysfunction was driven by multi-pronged mechanisms including suppression of NLRP3/caspase-1/IL-1β cascade, which was evidenced by dampened caspase-1 activity, lowered IL-1β/IL-18 production, and decreased nuclear levels of activated NF-κBp65. Moreover, curbing testicular apoptosis was seen by lowered Bax expression, decreased caspase-3 activity, and upregulation of Bcl-2. In tandem, testicular autophagy was activated as seen by diminished p62 SQSTM1 accumulation alongside Beclin-1 upregulation. Autophagy activation was associated with AMPK/mTOR pathway stimulation demonstrated by decreased mTOR (Ser2448) phosphorylation and increased AMPK (Ser487) phosphorylation. In conclusion, combating inflammation/apoptosis and enhancing autophagic events by topiramate were engaged in ameliorating cadmium-induced testicular impairment.

Cardiovascular protection by SGLT2 inhibitors - Do anti-inflammatory mechanisms play a role?

BACKGROUND

Metabolic syndrome and related metabolic disturbances represent a state of low-grade inflammation, which accelerates insulin resistance, type 2 diabetes (T2D) and cardiovascular disease (CVD) progression. Among antidiabetic medications, sodium glucose co-transporter (SGLT) 2 inhibitors are the only agents which showed remarkable reductions in heart failure (HF) hospitalizations and major cardiovascular endpoints (MACE) as well as renal endpoints regardless of diabetes status in large randomized clinical outcome trials (RCTs). Although the exact mechanisms underlying these benefits are yet to be established, growing evidence suggests that modulating inflammation by SGLT2 inhibitors may play a key role.

SCOPE OF REVIEW

In this manuscript, we summarize the current knowledge on anti-inflammatory effects of SGLT2 inhibitors as one of the mechanisms potentially mediating their cardiovascular (CV) benefits. We introduce the different metabolic and systemic actions mediated by these agents which could mitigate inflammation, and further present the signalling pathways potentially responsible for their proposed direct anti-inflammatory effects. We also discuss controversies surrounding some of these mechanisms.

MAJOR CONCLUSIONS

SGLT2 inhibitors are promising anti-inflammatory agents by acting either indirectly via improving metabolism and reducing stress conditions or via direct modulation of inflammatory signalling pathways. These effects were achieved, to a great extent, in a glucose-independent manner which established their clinical use in HF patients with and without diabetes.

Recent Advances in Designing Electroconductive Biomaterials for Cardiac Tissue Engineering

Implantable cardiac patches and injectable hydrogels are among the most promising therapies for cardiac tissue regeneration following myocardial infarction. Incorporating electrical conductivity into these patches and hydrogels is found to be an efficient method to improve cardiac tissue function. Conductive nanomaterials such as carbon nanotube, graphene oxide, gold nanorod, as well as conductive polymers such as polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate are appealing because they possess the electroconductive properties of semiconductors with ease of processing and have potential to restore electrical signaling propagation through the infarct area. Numerous studies have utilized these materials for regeneration of biological tissues that possess electrical activities, such as cardiac tissue. In this review, recent studies on the use of electroconductive materials for cardiac tissue engineering and their fabrication methods are summarized. Moreover, recent advances in developing electroconductive materials for delivering therapeutic agents as one of emerging approaches for treating heart diseases and regenerating damaged cardiac tissues are highlighted.

Pathogenetic Link of Cardiac Rupture and Left Ventricular Thrombus Following Acute Myocardial Infarction: A Joint Preclinical and Clinical Study

Background

Cardiac rupture (CR) and left ventricular thrombus (LVT) remain important complications of acute myocardial infarction (MI), and they are currently regarded as independent events. We explored the pathogenetic link between CR and LVT by investigating a murine model of MI with a high frequency of CR and in patients with acute MI.

Methods

MI was induced in mice, the onset of CR was monitored, and the hearts of mice with or without fatal CR were histologically examined. Between 2015 and 2022, from patients admitted due to acute MI, the data of patients with CR or LVT were retrospectively collected and compared to uncomplicated patients (control).

Results

A total of 75% of mice (n = 65) with MI developed CR 2–4 days after MI. A histological examination of CR hearts revealed the existence of platelet-rich intramural thrombi in the rupture tunnel, which was connected at the endocardial site to platelet-fibrin thrombi within an LVT. In CR or non-CR mouse hearts, LV blood clots often contained a portion of platelet-fibrin thrombi that adhered to the infarct wall. In non-CR hearts, sites of incomplete CR or erosion of the infarct wall were typically coated with platelet thrombi and dense inflammatory cells. Of 8,936 patients with acute MI, CR and LVT occurred in 102 (1.14%) and 130 (1.45%) patients, respectively, with three cases having both complications. CR accounted for 32.8% of in-hospital deaths. The majority of CR (95%) or LVT (63%, early LVT) occurred within 7 days. In comparison to the control or LVT-late groups, patients with CR or early LVT reported increased levels of cellular and biochemical markers for inflammation or cardiac injury.

Conclusion

CR and LVT after MI are potentially linked in their pathogenesis. LVT occurring early after MI may be triggered by a thrombo-inflammatory response following wall rupture or endocardial erosion.

Effects of IL-38 on Macrophages and Myocardial Ischemic Injury

Macrophages play an important role in clearing necrotic myocardial tissues, myocardial ischemia-reperfusion injury, and ventricular remodeling after myocardial infarction. M1 macrophages not only participate in the inflammatory response in myocardial tissues after infarction, which causes heart damage, but also exert a protective effect on the heart during ischemia. In contrast, M2 macrophages exhibit anti-inflammatory and tissue repair properties by inducing the production of high levels of anti-inflammatory cytokines and fibro-progenitor cells. Interleukin (IL)-38, a new member of the IL-1 family, has been reported to modulate the IL-36 signaling pathway by playing a role similar to that of the IL-36 receptor antagonist, which also affects the production and secretion of macrophage-related inflammatory factors that play an anti-inflammatory role. IL-38 can relieve myocardial ischemia-reperfusion injury by promoting the differentiation of M1 macrophages into M2 macrophages, inhibit the activation of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome, and increase the secretion of anti-inflammatory cytokines, such as IL-10 and transforming growth factor-β. The intact recombinant IL-38 can also bind to interleukin 1 receptor accessory protein-like 1 (IL-1RAPL1) to activate the c-jun N-terminal kinase/activator protein 1 (JNK/AP1) pathway and increase the production of IL-6. In addition, IL-38 regulates dendritic cell-induced cardiac regulatory T cells, thereby regulating macrophage polarization and improving ventricular remodeling after myocardial infarction. Accordingly, we speculated that IL-38 and macrophage regulation may be therapeutic targets for ameliorating myocardial ischemic injury and ventricular remodeling after myocardial infarction. However, the specific mechanism of the IL-38 action warrants further investigation.

In vivo Visualization of M2 Macrophages in the Myocardium After Myocardial Infarction (MI) Using 68Ga-NOTA-Anti-MMR Nb: Targeting Mannose Receptor (MR, CD206) on M2 Macrophages

Introduction and Objectives

Wound healing after myocardial infarction (MI) is a dynamic and complex multiple phase process, and a coordinated cellular response is required for proper scar formation. The current paradigm suggests that pro-inflammatory monocytes infiltrate the MI zone during the initial pro-inflammatory phase and differentiate into inflammatory macrophages, and then switch their phenotypes to anti-inflammatory during the reparative phase. Visualization of the reparative phase post-MI is of great interest because it may reveal delayed resolution of inflammation, which in turn predicts adverse cardiac remodeling. Imaging of anti-inflammatory macrophages may also be used to assess therapy approaches aiming to modulate the inflammatory response in order to limit MI size. Reparative macrophages can be distinguished from inflammatory macrophages by the surface marker mannose receptor (MR, CD206). In this study we evaluated the feasibility of ⁶⁸Ga-NOTA-anti-MMR Nb for imaging of MR on alternatively activated macrophages in murine MI models.

Methods

Wildtype and MR-knockout mice and Wistar rats were subjected to MI via permanent ligation of the left coronary artery. Non-operated or sham-operated animals were used as controls. MR expression kinetics on cardiac macrophages was measured in mice using flow cytometry. PET/CT scans were performed 1 h after intravenous injection of ⁶⁸Ga-NOTA-anti-MMR Nb. Mice and rats were euthanized and hearts harvested for ex vivo PET/MRI, autoradiography, and staining. As a non-targeting negative control, ⁶⁸Ga-NOTA-BCII10 was used.

Results

In vivo-PET/CT scans showed focal radioactivity signals in the infarcted myocardium for ⁶⁸Ga-NOTA-anti-MMR Nb which were confirmed by ex vivo-PET/MRI scans. In autoradiography images, augmented uptake of the tracer was observed in infarcts, as verified by the histochemistry analysis. Immunofluorescence staining demonstrated the presence and co-localization of CD206- and CD68-positive cells, in accordance to infarct zone. No in vivo or ex vivo signal was observed in the animals injected with control Nb or in the sham-operated animals. ⁶⁸Ga-NOTA-anti-MMR Nb uptake in the infarcts of MR-knockout mice was negligibly low, confirming the specificity of ⁶⁸Ga-NOTA-anti-MMR Nb to MR.

Conclusion

This exploratory study highlights the potential of ⁶⁸Ga-NOTA-anti-MMR Nb to image MR-positive macrophages that are known to play a pivotal role in wound healing that follows acute MI.

Role of CCR2-Positive Macrophages in Pathological Ventricular Remodelling

Even with recent advances in care, heart failure remains a major cause of morbidity and mortality, which urgently needs new treatments. One of the major antecedents of heart failure is pathological ventricular remodelling, the abnormal change in the size, shape, function or composition of the cardiac ventricles in response to load or injury. Accumulating immune cell subpopulations contribute to the change in cardiac cellular composition that occurs during ventricular remodelling, and these immune cells can facilitate heart failure development. Among cardiac immune cell subpopulations, macrophages that are recognized by their transcriptional or cell-surface expression of the chemokine receptor C-C chemokine receptor type 2 (CCR2), have emerged as playing an especially important role in adverse remodelling. Here, we assimilate the literature that has been generated over the past two decades describing the pathological roles that CCR2+ macrophages play in ventricular remodelling. The goal is to facilitate research and innovation efforts in heart failure therapeutics by drawing attention to the importance of studying the manner by which CCR2+ macrophages mediate their deleterious effects.

Soluble fibrinogen‑like protein 2 levels are decreased in patients with ischemic heart failure and associated with cardiac function

Soluble fibrinogen‑like protein 2 (sFGL2), as a novel effector of regulatory T cells (Tregs), exhibits immune regulatory activity in several inflammatory diseases. Immune activation and persistent inflammation participate in the progression of ischemic heart failure (IHF). The present study aimed to determine serum sFGL2 levels in patients with IHF and explore the relationship between sFGL2 levels and cardiac function. A total of 104 patients with IHF and 32 healthy controls were enrolled. patients with IHF were further split into subgroups according to the New York Heart Association functional classification or left ventricular ejection fraction (LVEF). Serum sFGL2 levels and peripheral Tregs frequencies were analyzed by ELISA and flow cytometry, respectively. The suppressive function of Tregs was measured by proliferation and functional suppression assays. Serum levels of sFGL2 and circulating Tregs frequencies were significantly decreased in patients with IHF compared with healthy controls. In patients with IHF, sFGL2 levels and Tregs frequencies were decreased with the deterioration of cardiac function. Tregs from patients with IHF exhibited compromised ability to suppress CD4+CD25‑ T cells proliferation and inflammatory cytokines secretion. Specifically, sFGL2 levels and Tregs frequencies positively correlated with LVEF, whereas negatively correlated with left ventricular end‑diastolic dimension and N‑terminal pro‑brain natriuretic peptide. sFGL2 levels were positively correlated with Tregs frequencies. In conclusion, the reduction of serum sFGL2 levels are associated with the progression of IHF and sFGL2 could be used as a potential indicator for predicting disease severity.

The immunomodulatory effects of topiramate on azoxymethane-induced colon carcinogenesis in rats: The role of the inflammatory cascade, vascular endothelial growth factor, AKT/mTOR/MAP kinase signaling and the apoptotic markers

BACKGROUND

Colon cancer is a malignant condition that affects the lower gastrointestinal tract and has unfavorable prognosis. Its mechanisms range from enhanced production of reactive oxygen species, inflammatory changes in the colon microenvironment and affection of the apoptotic pathways. Due to the high incidence of resistance of colon cancer to the traditional chemotherapeutic agents, a need for finding safe/effective agents that can attenuate the malignant changes had emerged.

OBJECTIVE

To investigate the possible immunomodulatory and antitumor effects of topiramate on azoxymethane-induced colon cancer in rats.

METHODOLOGY

Fifty male Wistar rats were randomized into five equal groups as follows: Control; azoxymethane-induced colon cancer; azoxymethane + methyl cellulose; azoxymethane + topiramate small dose; and azoxymethane + topiramate large dose. The body weight gain, serum carcinoembryonic antigen (CEA), tissue antioxidant status, proinflammatory cytokines, vascular endothelial growth factor (VEGF), Nrf2/HO-1 content, p-AKT, mTOR, p38 MAP kinase, caspase 9, nerve growth factor beta and beclin-1 were measured. Also, parts of the colon had undergone histopathological and immunohistochemical evaluation.

KEY FINDINGS

Topiramate improved the body weight gain, decreased serum CEA, augmented the antioxidant defenses in the colonic tissues with significant amelioration of the inflammatory changes, decline in tissue VEGF and p-AKT/mTOR/MAP kinase signaling and increased Nrf2/HO-1 content in a dose-dependent manner when compared to rats treated with azoxymethane alone. In addition, topiramate, in a dose-dependent manner, significantly enhanced apoptosis and improved the histopathological picture in comparison to animals treated with azoxymethane alone.

CONCLUSION

Taking these findings together, topiramate might serve as a new effective adjuvant line of treatment of colon cancer.

The GABAA Receptor Influences Pressure Overload-Induced Heart Failure by Modulating Macrophages in Mice

Background

Myocardial macrophages have key roles in cardiac remodeling and dysfunction. The gamma-aminobutyric acid subtype A (GABAA) receptor was recently found to be distributed in macrophages, allowing regulation of inflammatory responses to various diseases. This study aimed to clarify the role of GABAA receptor-mediated macrophage responses in pressure overload-induced heart failure.

Methods and Results

C57BL/6J mice underwent transverse aortic constriction for pressure-overload hypertrophy (POH) and were intraperitoneally treated with a specific GABAA receptor agonist (topiramate) or antagonist (bicuculline). Echocardiography, histology, and flow cytometry were performed to evaluate the causes and effects of myocardial hypertrophy and fibrosis. Activation of the GABAA receptor by topiramate reduced ejection fraction and fractional shortening, enlarged the end-diastolic and end-systolic left ventricular internal diameter, aggravated myocardial hypertrophy and fibrosis, and accelerated heart failure in response to pressure overload. Mechanistically, topiramate increased the number of Ly6Clow macrophages in the heart during POH and circulating Ly6Chigh classic monocyte infiltration in late-phase POH. Further, topiramate drove Ly6Clow macrophages toward MHCIIhigh macrophage polarization. As a result, Ly6Clow macrophages activated the amphiregulin-induced AKT/mTOR signaling pathway, and Ly6ClowMHCIIhigh macrophage polarization increased expression levels of osteopontin and TGF-β, which led to myocardial hypertrophy and fibrosis. Conversely, GABAA receptor blockage with bicuculline reversed these effects.

Conclusions

Control of the GABAA receptor activity in monocytes/macrophages plays an important role in myocardial hypertrophy and fibrosis after POH. Blockade of the GABAA receptor has the potential to improve pressure overload-induced heart failure.

Post-ischemic Myocardial Inflammatory Response: A Complex and Dynamic Process Susceptible to Immunomodulatory Therapies

Following acute occlusion of a coronary artery causing myocardial ischemia and implementing first-line treatment involving rapid reperfusion, a dynamic and balanced inflammatory response is initiated to repair and remove damaged cells. Paradoxically, restoration of myocardial blood flow exacerbates cell damage as a result of myocardial ischemia-reperfusion (MI-R) injury, which eventually provokes accelerated apoptosis. In the end, the infarct size still corresponds to the subsequent risk of developing heart failure. Therefore, true understanding of the mechanisms regarding MI-R injury, and its contribution to cell damage and cell death, are of the utmost importance in the search for successful therapeutic interventions to finally prevent the onset of heart failure. This review focuses on the role of innate immunity, chemokines, cytokines, and inflammatory cells in all three overlapping phases following experimental, mainly murine, MI-R injury known as the inflammatory, reparative, and maturation phase. It provides a complete state-of-the-art overview including most current research of all post-ischemic processes and phases and additionally summarizes the use of immunomodulatory therapies translated into clinical practice.

Chemical and Biochemical Aspects of Molecular Hydrogen in Treating Kawasaki Disease and COVID-19

Kawasaki disease (KD) is a systemic vasculitis and is the most commonly acquired heart disease among children in many countries, which was first reported 50 years ago in Japan. The 2019 coronavirus disease (COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) has been a pandemic in most of the world since 2020, and since late 2019 in China. Kawasaki-like disease caused by COVID-19 shares some symptoms with KD, referred to as multisystem inflammatory syndrome in children, and has been reported in the United States, Italy, France, England, and other areas of Europe, with an almost 6-10 times or more increase compared with previous years of KD prevalence. Hydrogen gas is a stable and efficient antioxidant, which has a positive effect on oxidative damage, inflammation, cell apoptosis, and abnormal blood vessel inflammation. This review reports the chemical and biochemical aspects of hydrogen gas inhalation in treating KD and COVID-19.

Modulating Neuro-Immune-Induced Macrophage Polarization With Topiramate Attenuates Experimental Abdominal Aortic Aneurysm

The development of abdominal aortic aneurysm (AAA) is attributed to psychological and physical factors. Topiramate, which is an agonist of the GABA_A receptor, makes contributions to neuronal disease and is partially involved in immune regulation, may be effective upon abdominal aortic aneurysm progression. We used experimental abdominal aortic aneurysm models: Angiotensin II (Ang II)–induced ApoE^−/− male mice (Ang II/APOE model) in our study. In the Ang II/APOE model, all mice (n=64) were divided into four groups: sham group (PBS treatment), control group (Ang II treatment), low-dose group (Ang II + low-dose topiramate, 3 mg/day per mouse), and high-dose group (Ang II + high-dose topiramate, 6 mg/day per mouse). All treatments began on the day after surgery. Moreover, collected tissues and cultured cell were used for histology and biochemical examination. In vitro, the effects of topiramate on bone marrow-derived macrophage stimulated by LPS were investigated. Our data implied that topiramate treatment significantly promoted macrophages preservation and conversion of M1 to M2 macrophage phenotypes in vivo and in vitro. Accordingly, proinflammatory activities mediated by the M1 macrophages were decreased and the repair process mediated by M2 macrophages was enhanced. The low-dose and high-dose groups had abdominal aortic aneurysm incidences of 50% and 37.5%, respectively, compared with 75% in the control group. Topiramate, a promising drug for the psychological disease, that target neuro-immune-induced macrophage polarization may attenuate experimental abdominal aortic aneurysm progression.

Cardiovascular effects of antiobesity drugs: are the new medicines all the same?

Waiting for a definite answer from well-designed randomized prospective clinical trials, the impact of the new antiobesity drugs -liraglutide, bupropion/naltrexone, phentermine/topiramate and lorcaserin- on cardiovascular outcomes remains uncertain. What has been learned from previous experience with older medicines is that antiobesity drugs may influence cardiovascular health not only causing weight reduction but also through direct actions on the cardiovascular system. Therefore, in the present review, we examine what is known, mainly from preclinical investigations, about the cardiovascular pharmacology of the new antiobesity medicines with the aim of highlighting potential mechanistic differences. We will show that the two active substances of the bupropion/naltrexone combination both exert beneficial and unwanted cardiovascular effects. Indeed, bupropion exerts anti-inflammatory effects but at the same time it does increase heart rate and blood pressure by potentiating catecholaminergic neurotransmission, whereas naltrexone reduces TLR4-dependent inflammation and has potential protective effects in stroke but also impairs cardiac adaption to ischemia and the beneficial opioid protective effects mediated in the endothelium. On the contrary, with the only exception of a small increase in heat rate, liraglutide only exerts favorable cardiovascular effects by protecting myocardium and brain from ischemic damage, improving heart contractility, lowering blood pressure and reducing atherogenesis. As far as the phentermine/topiramate combination is concerned, no direct cardiovascular beneficial effect is expected for phentermine (as this drug is an amphetamine derivative), whereas topiramate may exert cardioprotective and neuroprotective effects in ischemia and anti-inflammatory and antiatherogenic actions. Finally, lorcaserin, a selective 5HT_2C receptor agonist, does not seem to exert significant direct effects on the cardiovascular system though at very high concentrations this drug may also interact with other serotonin receptor subtypes and exert unwanted cardiovascular effects. In conclusion, the final effect of the new antiobesity drugs on cardiovascular outcomes will be a balance between possible (but still unproved) beneficial effects of weight loss and "mixed" weight-independent drug-specific effects. Therefore comparative studies will be required to establish which one of the new medicines is more appropriate in patients with specific cardiovascular diseases.

Cardiac monocytes and macrophages after myocardial infarction

Improvements in early interventions after acute myocardial infarction (AMI), notably, the increased use of timely reperfusion therapy, have increased survival dramatically in recent decades. Despite this, maladaptive ventricular remodelling and subsequent heart failure (HF) following AMI remain a significant clinical challenge, particularly because several pre-clinical strategies to attenuate remodelling have failed to translate into clinical practice. Monocytes and macrophages, pleiotropic cells of the innate immune system, are integral in both the initial inflammatory response to injury and subsequent wound healing in many tissues, including the heart. However, maladaptive immune cell behaviour contributes to ventricular remodelling in mouse models, prompting experimental efforts to modulate the immune response to prevent the development of HF. Seminal work in macrophage biology defined macrophages as monocyte-derived cells that are comprised of two populations, pro-inflammatory M1 macrophages and reparative M2 macrophages, and initial investigations into cardiac macrophage populations following AMI suggested they aligned well to this model. However, more recent data, in the heart and other tissues, demonstrate remarkable heterogeneity and plasticity in macrophage development, phenotype, and function. These recent insights into macrophage biology may explain the failure of non-specific immunosuppressive strategies and offer novel opportunities for therapeutic targeting to prevent HF following AMI. Here, we summarize the traditional monocyte-macrophage paradigm, experimental evidence for the significance of these cells in HF after AMI, and the potential relevance of emerging evidence that refutes canonical models of monocyte and macrophage biology.

Getting an Early Start in Understanding Perinatal Asphyxia Impact on the Cardiovascular System

Perinatal asphyxia (PA) is a burdening pathology with high short-term mortality and severe long-term consequences. Its incidence, reaching as high as 10 cases per 1000 live births in the less developed countries, prompts the need for better awareness and prevention of cases at risk, together with management by easily applicable protocols. PA acts first and foremost on the nervous tissue, but also on the heart, by hypoxia and subsequent ischemia-reperfusion injury. Myocardial development at birth is still incomplete and cannot adequately respond to this aggression. Cardiac dysfunction, including low ventricular output, bradycardia, and pulmonary hypertension, complicates the already compromised circulatory status of the newborn with PA. Multiorgan and especially cardiovascular failure seem to play a crucial role in the secondary phase of hypoxic-ischemic encephalopathy (HIE) and its high mortality rate. Hypothermia is an acceptable solution for HIE, but there is a fragile equilibrium between therapeutic gain and cardiovascular instability. A profound understanding of the underlying mechanisms of the nervous and cardiovascular systems and a close collaboration between the bench and bedside specialists in these domains is compulsory. More resources need to be directed toward the prevention of PA and the consecutive decrease of cardiovascular dysfunction. Not much can be done in case of an unexpected acute event that produces PA, where recognition and prompt delivery are the key factors for a positive clinical result. However, the situation is different for high-risk pregnancies or circumstances that make the fetus more vulnerable to asphyxia. Improving the outcome in these cases is possible through careful monitoring, identifying the high-risk pregnancies, and the implementation of novel prenatal strategies. Also, apart from adequately supporting the heart through the acute episode, there is a need for protocols for long-term cardiovascular follow-up. This will increase our recognition of any lasting myocardial damage and will enhance our perspective on the real impact of PA. The goal of this article is to review data on the cardiovascular consequences of PA, in the context of an immature cardiovascular system, discuss the potential contribution of cardiovascular impairment on short and long-term outcomes, and propose further directions of research in this field.

Imaging inflammation after myocardial infarction: implications for prognosis and therapeutic guidance

Inflammation after myocardial infarction (MI) has been in the focus of cardiovascular research for several years as it influences the remodeling process of the ischemic heart and thereby critically determines the clinical outcome of the patient. Today, it is well appreciated that inflammation is a crucial necessity for the initiation of the natural wound healing process; however, excessive inflammation can have detrimental effects and might result in adverse ventricular remodeling which is associated with an increased risk of heart failure. Newly emerged imaging techniques facilitate the non-invasive assessment of immune cell infiltration into the ischemic myocardium and can provide greater insight into the underlying complex and dynamic repair mechanisms. Molecular imaging of inflammation in the context of MI may help with stratification of patients at high risk of adverse ventricular remodeling post-MI which may be of diagnostic, therapeutic, and prognostic value. Novel radiopharmaceuticals may additionally provide a way to combine patient monitoring and therapy. In spite of great advances in recent years in the field of imaging sciences, clinicians still need to overcome some obstacles to a wider implementation of inflammation imaging post-MI. This review focuses on inflammation as a molecular imaging target and its potential implication in prognosis and therapeutic guidance.

Immune cells as targets for cardioprotection: new players and novel therapeutic opportunities

New therapies are required to reduce myocardial infarct (MI) size and prevent the onset of heart failure in patients presenting with acute myocardial infarction (AMI), one of the leading causes of death and disability globally. In this regard, the immune cell response to AMI, which comprises an initial pro-inflammatory reaction followed by an anti-inflammatory phase, contributes to final MI size and post-AMI remodelling [changes in left ventricular (LV) size and function]. The transition between these two phases is critical in this regard, with a persistent and severe pro-inflammatory reaction leading to adverse LV remodelling and increased propensity for developing heart failure. In this review article, we provide an overview of the immune cells involved in orchestrating the complex and dynamic inflammatory response to AMI-these include neutrophils, monocytes/macrophages, and emerging players such as dendritic cells, lymphocytes, pericardial lymphoid cells, endothelial cells, and cardiac fibroblasts. We discuss potential reasons for past failures of anti-inflammatory cardioprotective therapies, and highlight new treatment targets for modulating the immune cell response to AMI, as a potential therapeutic strategy to improve clinical outcomes in AMI patients. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225.

Regulation of Type 2 Immunity in Myocardial Infarction

Type 2 immunity participates in the pathogeneses of helminth infection and allergic diseases. Emerging evidence indicates that the components of type 2 immunity are also involved in maintaining metabolic hemostasis and facilitating the healing process after tissue injury. Numerous preclinical studies have suggested regulation of type 2 immunity-related cytokines, such as interleukin-4, -13, and -33, and cell types, such as M2 macrophages, mast cells, and eosinophils, affects cardiac functions after myocardial infarction (MI), providing new insights into the importance of immune modulation in the infarcted heart. This review provides an overview of the functions of these cytokines and cells in the setting of MI as well as their potential to predict the severity and prognosis of MI.