Role of lymphocytes in myocardial injury, healing, and remodeling after myocardial infarction

CD8 cell-derived granzyme B may be a predictor for coronary artery involvement and MACE in Takayasu arteritis patients

Coronary artery involvement (CAI) is a special but not rare manifestation of Takayasu arteritis (TAK). Granzyme B (GzmB) is a multifunctional protease associated with the immune system and coronary artery disease. However, its role in patients with TAK and CAI remains unclear. This study investigates the role of GzmB+ cell subsets in TAK. The study included 105 TAK patients and 58 healthy controls. The percentages of different GzmB+ cells in blood samples were analyzed by flow cytometry. We found that age, age at onset, body mass index, disease duration month, hypertension, and hyperlipidemia were significantly different between TAK patients with and without CAI (P = 0.000, P = 0.038, P = 0.003, P = 0.031, P = 0.039, P = 0.000). The proportions of CD3+CD8+cells (P = 0.001) and CD3+CD4+cells (P = 0.000) in GzmB+ cells were significantly increased, while the proportion of CD3-CD56+cells (P = 0.001) in GzmB+ cells was decreased in TAK patients. The proportions of three types of GzmB+ subsets in lymphocytes (CD3+CD4+GzmB+, CD3+CD8+GzmB+, CD3+CD56+ GzmB+) were higher in TAK patients with CAI compared with those without CAI (P = 0.021, P = 0.007, P = 0.007). The increased proportion of CD3+CD8+GzmB+cells/lymphocytes was an independent risk factor for coronary involvement in TAK (OR = 4.990 [1.766-14.098], P = 0.002). Additionally, patients with a high CD3+CD8+GzmB+cells/lymphocytes ratio had a higher major adverse cardiovascular events rate than those with a low ratio in TAK (P = 0.019). Our results indicate that CD8 cell-derived Gzm B may be a predictor for CAI and major adverse cardiovascular events in TAK patients. Targeting CD3+CD8+GzmB+ lymphocytes or using GzmB inhibitors could be a potential therapeutic approach for the treatment of CAI in TAK.

T cells in cardiac health and disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, with inflammation playing a pivotal role in its pathogenesis. T lymphocytes are crucial components of the adaptive immune system that have emerged as key mediators in both cardiac health and the development and progression of CVD. This Review explores the diverse roles of T cell subsets, including Th1, Th17, γδ T cells, and Tregs, in myocardial inflammatory processes such as autoimmune myocarditis and myocardial infarction. We discuss the contribution of T cells to myocardial injury and remodeling, with emphasis on specific immune receptors, e.g., CD69, that have a critical role in regulating immune tolerance and maintaining the balance between T cell subsets in the heart. Additionally, we offer a perspective on recent advances in T cell-targeted therapies and their potential to modulate immune responses and improve clinical outcomes in patients with CVD and in heart transplant recipients. Understanding the intricate interplay between T cells and cardiovascular pathology is essential for developing novel immunotherapeutic strategies against CVD.

Eosinopenia in patients with acute myocardial infarction- longitudinal imaging insights from the CAPRI study

Eosinophils are recruited to the heart during acute myocardial infarction (MI) and are considered part of the inflammatory response associated with adverse clinical outcomes. We assessed the impact of eosinopenia on cardiac imaging biomarkers in patients presenting with ST-segment elevation MI. This is a post-hoc analysis of the Evaluating the effectiveness of intravenous Ciclosporin on reducing reperfusion injury in pAtients undergoing PRImary percutaneous coronary intervention (CAPRI) trial. Patients underwent cardiac MRI within 1 week and 12 weeks and low eosinophil was defined as less than 40 cells/ml. The study included 52 patients and 38% had low eosinophil. Ciclosporin administration was comparable between patients with low versus normal eosinophils. The ischaemia time was significantly longer in low eosinophil patients [262 (205-325) vs. 138 (102-195) minutes, P < 0.001]. At 12 weeks, patients with eosinopenia had larger infarct size [9.8% (5.7-18.4) vs. 7.4% (1.9-10.2), P = 0.045], larger left ventricle (LV) end systolic volume (89 ± 28 vs. 68 ± 23, P = 0.02), and lower LV ejection fraction (EF) (49 ± 9 vs. 58 ± 7, P < 0.001). After adjustments for significant predictors, including ischaemia time, low eosinophil count was an independent predictor of worse LVEF at 12 weeks [-5.78, 95% CI (-11.22 to -0.34), P = 0.038] but not infarct size [1.83, 95% CI (-2.77 to 6.43), P = 0.43]. Patients with low eosinophil count had larger infarct size and LV volumes and worse adverse remodeling compared to those with normal eosinophil count. At 12 weeks, eosinopenia was an independent predictor of worse LVEF but not infarct size.

Macrophages after myocardial infarction: Mechanisms for repairing and potential as therapeutic approaches

Macrophages - one of the crucial immune cells, are recruited to the cardiac tissue by chemokines, cytokines and upregulated endothelial adhesion molecules after myocardial infarction (MI). During the course of inflammation in the cardiac tissue, necrotic cells and matrix debris is phagocytosed by M1 macrophages. During the resolution phase of cardiac inflammation, M2 macrophages promote cardiac recovery. Suppression or over expression of both the M1 and M2 macrophage subtypes significantly affect the reparation of infarction. Stem cells therapy, cytokine regulation and immune cells therapy are considered as effective interventions to regulate the phenotypic transformation of cardiac macrophages after MI. Intervention with macrophages in the myocardium has shown unique advantages. In this review, the mechanisms and role of macrophages in the development of MI are elaborated in detail, the promising therapeutic methods for regulating macrophage phenotypes, their limitations and possible future research directions are discussed.

Potential therapeutic effects of IL28RA inhibition on acute myocardial infarction through phosphorylated JAK1/STAT1 signaling pathways

While current coronary intervention therapies and surgical bypass procedures are widely utilized, the treatment of acute myocardial infarction (AMI) in the elderly continues to pose significant challenges. Following AMI, the body's immune system is activated, resulting in the release of inflammatory mediators that exacerbate myocardial damage. Interleukin 28A (IL28A) and interleukin 28B (IL28B) may play a role in immune regulation post-AMI by specifically binding to interleukin 28 receptor alpha (IL28RA). However, the precise underlying mechanisms remain incompletely understood. This study aims to investigate the levels of IL28A and IL28B following AMI, as well as the protective effects of inhibiting IL28RA expression in the context of AMI and its potential mechanisms. We analyzed serum samples from 55 patients with AMI and 41 control individuals using ELISA to evaluate the levels of IL28A and IL28B, as well as to assess their correlation with the clinical parameters of the patients. Additionally, we established a mouse model of AMI and employed intramyocardial injection of lentivirus to knock down IL28RA in the myocardium. Echocardiography was utilized to compare structural and functional changes, while HE staining was conducted to analyze the infarct area and assess changes in myocardial tissue and cell morphology. The expressions of IL28A, IL28B, IL28RA, and JAK1/STAT1 pathway-related proteins in the infarct area were compared through immunofluorescence and Western blot analysis. Finally, TUNEL staining and the BAX/Bcl2 ratio were utilized to evaluate cardiomyocyte apoptosis. The study demonstrated that serum IL28A levels in patients with AMI were significantly elevated compared to those in normal controls, whereas IL28B levels were significantly reduced. Additionally, both IL28A and IL28B levels exhibit a linear relationship with high-density lipoprotein (HDL) and body mass index (BMI). In a mouse model, cardiac function deteriorated and ventricular structural changes were observed 14 days post-myocardial infarction relative to controls. The expressions of IL28A and IL28RA were significantly upregulated in the myocardium of the infarcted area, while IL28B levels showed no significant variation. Additionally, the ratios of p-JAK1/JAK1 and p-STAT1/STAT1 were significantly increased, accompanied by a notable rise in apoptotic cells within the myocardial infarction area. Importantly, the knockdown of IL28RA expression in the infarcted region effectively mitigated these alterations. These results suggest that IL28A but not IL28B contributes to the process post-AMI and may induce cardiomyocyte apoptosis through the JAK1/STAT1 pathway in conjunction with IL28RA.

Prognostic significance of C-reactive protein-albumin-lymphocyte (CALLY) index after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction

BACKGROUND

In this study, the relationship between C-reactive protein-albumin-lymphocyte (CALLY) index, a novel composite indicator based on inflammation and nutrition, and major adverse cardiovascular events (MACEs) was investigated in patients with ST-segment elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

This retrospective study included 438 patients with STEMI who were treated at a single center between January 2017 and December 2020. The CALLY index was calculated for each patient on admission. The predictive value of the CALLY index for short- and long-term MACEs was evaluated using the area under the curve (AUC) analysis, and the corresponding AUC values were calculated. Clinical characteristics were analyzed after categorizing the population based on the optimal cut-off value of the CALLY index. Multivariate Cox regression analysis was used to determine factors independently associated with MACEs, while logistic regression analysis was used to identify factors independently associated with the severity of coronary artery lesions. Kaplan-Meier estimation and log-rank test were used to assess event-free survival rates among different CALLY index groups. Additionally, Spearman's correlation test was used to determine the association between the CALLY index and the Gensini score.

RESULTS

The AUC for predicting short-term MACEs in STEMI patients using the CALLY index was 0.758, while the AUC for predicting long-term MACEs was 0.740. Similarly, the AUC values were 0.815 and 0.819, respectively, when evaluating the short- and long-term mortality rates using the CALLY index. Multivariable Cox regression analysis revealed that a high CALLY index (threshold of 1.50) independently reduced the risk of short-term MACEs in patients with STEMI (hazard ratio [HR] = 0.274, 95 % confidence interval [CI] = 0.121-0.621, P=0.002). Multivariable Cox regression also demonstrated that a high CALLY index (threshold > 0.91) independently reduced the occurrence of long-term MACEs during follow-up in STEMI patients (HR=0.439, 95 % CI=0.292-0.659, P<0.001). Furthermore, multivariate logistic regression analysis revealed that a high CALLY index (threshold > 1.13) independently reduced the risk of severe coronary artery lesions in patients with STEMI (odds ratio = 0.299 [95 % CI=184-0.485], P<0.001). A positive correlation was observed between the CALLY index and the Gensini score (P<0.001).

CONCLUSION

The CALLY index is a novel, convenient, and valuable prognostic indicator exhibiting a protective effect against both short- and long-term MACEs in patients with STEMI, emphasizing the significance of inflammation/nutrition in this patient population.

Identification of immune feature genes and intercellular profiles in diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DCM) is a multifaceted cardiovascular disorder in which immune dysregulation plays a pivotal role. The immunological molecular mechanisms underlying DCM are poorly understood.

AIM

To examine the immunological molecular mechanisms of DCM and construct diagnostic and prognostic models of DCM based on immune feature genes (IFGs).

METHODS

Weighted gene co-expression network analysis along with machine learning methods were employed to pinpoint IFGs within bulk RNA sequencing (RNA-seq) datasets. Single-sample gene set enrichment analysis (ssGSEA) facilitated the analysis of immune cell infiltration. Diagnostic and prognostic models for these IFGs were developed and assessed in a validation cohort. Gene expression in the DCM cell model was confirmed through real time-quantitative polymerase chain reaction and western blotting techniques. Additionally, single-cell RNA-seq data provided deeper insights into cellular profiles and interactions.

RESULTS

The overlap between 69 differentially expressed genes in the DCM-associated module and 2483 immune genes yielded 7 differentially expressed immune-related genes. Four IFGs showed good diagnostic and prognostic values in the validation cohort: Proenkephalin (Penk) and retinol binding protein 7 (Rbp7), which were highly expressed, and glucagon receptor and inhibin subunit alpha, which were expressed at low levels in DCM patients (all area under the curves > 0.9). SsGSEA revealed that IFG-related immune cell infiltration primarily involved type 2 T helper cells. High expression of Penk (P < 0.0001) and Rbp7 (P = 0.001) was detected in cardiomyocytes and interstitial cells and further confirmed in a DCM cell model in vitro. Intercellular events and communication analysis revealed abnormal cellular phenotype transformation and signaling communication in DCM, especially between mesenchymal cells and macrophages.

CONCLUSION

The present study identified Penk and Rbp7 as potential DCM biomarkers, and aberrant mesenchymal-immune cell phenotype communication may be an important aspect of DCM pathogenesis.

The Combination Effect of the Red Blood Cell Distribution Width and Prognostic Nutrition Index on the Prognosis in Patients Undergoing PCI

BACKGROUND

Inflammation and malnutrition are related to adverse clinical outcomes in patients with coronary artery disease (CAD). However, it is unclear whether there is a relationship between the PNI (prognostic nutritional index) and RDW (red blood cell distribution width) regarding the impact on the prognosis in patients with CAD undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 5605 consecutive CAD patients undergoing PCI were selected retrospectively. The patients were stratified into four groups according to the PNI [high PNI (H-PNI) and low PNI (L-PNI)] and RDW [high RDW (H-RDW) and low RDW (L-RDW)]. The cutoff values of RDW and PNI were calculated using receiver-operating characteristic curve analysis. The primary endpoint was 1-year all-cause mortality (ACM). The secondary endpoint was major adverse cardiac cerebrovascular events (MACCEs), the composite of cardiac death (CD), the recurrence of MI, target lesion revascularization (TLR), and stroke. A Cox proportional hazards model was used to evaluate the association between the PNI, RDW, and clinical endpoints.

RESULTS

During 1-year follow-up, 235 (4.19%) patients died. In multivariate regression analysis, the L-PNI/H-RDW group was found to have the highest risk of 1-year ACM [hazard ratio (HR) = 8.85, 95% confidence interval (CI): 5.96-13.15, p = 0.020] with the H-PNI/L-RDW group as a reference, followed by the L-PNI/L-RDW (HR = 3.96, 95% CI: 2.60-6.00, p < 0.001) and H-RDW/H-PNI groups (HR = 3.00, 95% CI: 1.99-4.50, p < 0.001). Nomograms were developed to predict the probability of 1-year ACM and MACCEs.

CONCLUSIONS

CAD patients with L-PNI and H-RDW experienced the worst prognosis. The combination of PNI and RDW was a strong predictor of 1-year ACM. The coexistence of PNI and RDW appears to have a synergistic effect, providing further information for the risk stratification of CAD patients.

Changes in the Release of Endothelial Extracellular Vesicles CD144+, CCR6+, and CXCR3+ in Individuals with Acute Myocardial Infarction

Acute myocardial infarction (AMI) results from vulnerable plaque rupture, causing ischemic cardiomyocyte necrosis and intense inflammation. Paradoxically, this inflammation releases factors that aid heart repair. Recent findings suggest a role for extracellular vesicles (EVs) in intercellular communication during post-AMI cardiac repair. However, EVs' tissue origin and chemokine profile in the blood of patients with AMI remains unclear. This study characterized the tissue origin and chemokine receptor profile of EVs in the coronary and peripheral blood of patients with AMI. The results reveal that vesicles isolated from coronary and peripheral blood plasma are enriched in tetraspanin (CD9) and express CD81+, CD90+, and CD144+. The vesicle size ranged between 145 and 162 nm, with the control group exhibiting smaller vesicles (D10) than the AMI group. Furthermore, all vesicles expressed CCR6 and CXCR3, whereas a small percentage expressed CCR4. In addition, a decrease in CXCR3 and CCR6 expression was observed in coronary and peripheral AMI blood vesicles compared with the control; however, no difference was found between AMI coronary and AMI peripheral blood vesicles. In conclusion, our study demonstrates, for the first time, changes in the number of extracellular vesicles expressing CD144+, CXCR3, and CCR6 in the peripheral circulation of patients with AMI. Extracellular vesicles present in the circulation of patients with AMI hold excellent promise as a potential diagnostic tool.

Vagal nerve stimulation in myocardial ischemia/reperfusion injury: from bench to bedside

The identification of acute cardioprotective strategies against myocardial ischemia/reperfusion (I/R) injury that can be applied in the catheterization room is currently an unmet clinical need and several interventions evaluated in the past at the pre-clinical level have failed in translation. Autonomic imbalance, sustained by an abnormal afferent signalling, is a key component of I/R injury. Accordingly, there is a strong rationale for neuromodulation strategies, aimed at reducing sympathetic activity and/or increasing vagal tone, in this setting. In this review we focus on cervical vagal nerve stimulation (cVNS) and on transcutaneous auricular vagus nerve stimulation (taVNS); the latest has the potential to overcome several of the issues of invasive cVNS, including the possibility of being used in an acute setting, while retaining its beneficial effects. First, we discuss the pathophysiology of I/R injury, that is mostly a consequence of the overproduction of reactive oxygen species. Second, we describe the functional anatomy of the parasympathetic branch of the autonomic nervous system and the most relevant principles of bioelectronic medicine applied to electrical vagal modulation, with a particular focus on taVNS. Then, we provide a detailed and comprehensive summary of the most relevant pre-clinical studies of invasive and non-invasive VNS that support its strong cardioprotective effect whenever there is an acute or chronic cardiac injury and specifically in the setting of myocardial I/R injury. The potential benefit in the emerging field of post cardiac arrest syndrome (PCAS) is also mentioned. Indeed, electrical cVNS has a strong anti-adrenergic, anti-inflammatory, antioxidants, anti-apoptotic and pro-angiogenic effect; most of the involved molecular pathways were already directly confirmed to take place at the cardiac level for taVNS. Pre-clinical data clearly show that the sooner VNS is applied, the better the outcome, with the possibility of a marked infarct size reduction and almost complete left ventricular reverse remodelling when VNS is applied immediately before and during reperfusion. Finally, we describe in detail the limited but very promising clinical experience of taVNS in I/R injury available so far.

The Role of Inflammation in the Pathogenesis of Cardiogenic Shock Secondary to Acute Myocardial Infarction: A Narrative Review

Cardiogenic shock (CS) is one of the most serious complications of myocardial infarction (MI) with a high mortality rate. The timely and effective prevention and early suppression of this adverse event may influence the prognosis and outcome in patients with MI complicated by CS (MI CS). Despite the use of existing pharmaco-invasive options for maintaining an optimal pumping function of the heart in patients with MI CS, its mortality remains high, prompting the search for new approaches to pathogenetic therapy. This review considers the role of the systemic inflammatory response in the pathogenesis of MI CS. The primary processes involved in its initiation are described, including the progression from the onset of MI to the generalization of the inflammatory response and the development of multiple organ dysfunction. The approaches to anti-inflammatory therapy in patients with CS are discussed, and further promising research directions are outlined. In this review, we updated and summarized information on the inflammatory component of MI CS pathogenesis with a particular focus on its foundational aspects. This will facilitate the identification of specific inflammatory phenotypes and endotypes in MI CS and the development of targeted therapeutic strategies for this MI complication.

Cytotoxic T cells drive doxorubicin-induced cardiac fibrosis and systolic dysfunction

Doxorubicin, the most prescribed chemotherapeutic drug, causes dose-dependent cardiotoxicity and heart failure. However, our understanding of the immune response elicited by doxorubicin is limited. Here we show that an aberrant CD8+ T cell immune response following doxorubicin-induced cardiac injury drives adverse remodeling and cardiomyopathy. Doxorubicin treatment in non-tumor-bearing mice increased circulating and cardiac IFNγ+CD8+ T cells and activated effector CD8+ T cells in lymphoid tissues. Moreover, doxorubicin promoted cardiac CD8+ T cell infiltration and depletion of CD8+ T cells in doxorubicin-treated mice decreased cardiac fibrosis and improved systolic function. Doxorubicin treatment induced ICAM-1 expression by cardiac fibroblasts resulting in enhanced CD8+ T cell adhesion and transformation, contact-dependent CD8+ degranulation and release of granzyme B. Canine lymphoma patients and human patients with hematopoietic malignancies showed increased circulating CD8+ T cells after doxorubicin treatment. In human cancer patients, T cells expressed IFNγ and CXCR3, and plasma levels of the CXCR3 ligands CXCL9 and CXCL10 correlated with decreased systolic function.

The interplay between T lymphocytes and macrophages in myocardial ischemia/reperfusion injury

Acute myocardial infarction is one of the most important causes of death in the world, causing a huge health and economic burden to the world. It is still a ticklish problem how to effectively prevent reperfusion injury while recovering the blood flow of ischemic myocardium. During the process of myocardial ischemia/reperfusion injury (MI/RI), the modulation of immune cells plays an important role. Monocyte/macrophage, neutrophils and endothelial cells initiate the inflammatory response and induce the release of various inflammatory cytokines, resulting in increased vascular permeability, tissue edema and damage. Meanwhile, T cells were recruited to impaired myocardium and release pro-inflammatory and anti-inflammatory cytokines. T cells and macrophages play important roles in keeping cardiac homeostasis and orchestrate tissue repair. T cells differentiation and macrophages polarization precisely regulates the tissue microenvironment in MI/RI, and shows cross action, but the mechanism is unclear. To identify potential intervention targets and propose ideas for treatment and prevention of MI/RI, this review explores the crosstalk between T lymphocytes and macrophages in MI/RI.

The Influence of Metabolic Risk Factors on the Inflammatory Response Triggered by Myocardial Infarction: Bridging Pathophysiology to Treatment

Myocardial infarction (MI) sets off a complex inflammatory cascade that is crucial for effective cardiac healing and scar formation. Yet, if this response becomes excessive or uncontrolled, it can lead to cardiovascular complications. This review aims to provide a comprehensive overview of the tightly regulated local inflammatory response triggered in the early post-MI phase involving cardiomyocytes, (myo)fibroblasts, endothelial cells, and infiltrating immune cells. Next, we explore how the bone marrow and extramedullary hematopoiesis (such as in the spleen) contribute to sustaining immune cell supply at a cardiac level. Lastly, we discuss recent findings on how metabolic cardiovascular risk factors, including hypercholesterolemia, hypertriglyceridemia, diabetes, and hypertension, disrupt this immunological response and explore the potential modulatory effects of lifestyle habits and pharmacological interventions. Understanding how different metabolic risk factors influence the inflammatory response triggered by MI and unraveling the underlying molecular and cellular mechanisms may pave the way for developing personalized therapeutic approaches based on the patient's metabolic profile. Similarly, delving deeper into the impact of lifestyle modifications on the inflammatory response post-MI is crucial. These insights may enable the adoption of more effective strategies to manage post-MI inflammation and improve cardiovascular health outcomes in a holistic manner.

Innate and adaptive immunity in acute myocarditis

Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.

Prognostic significance of the aspartate aminotransferase to lymphocyte ratio index in patients with acute myocardial infarction

BACKGROUND

This study aimed to investigate the clinical value and prognostic significance of the alanine aspartate aminotransferase-to-lymphocyte ratio index (ALRI) in patients diagnosed with acute myocardial infarction (AMI).

METHODS

Clinical indices of patients with AMI were collected from the Medical Information Mark for Intensive Care (MIMIC) III database and Wuhan Sixth Hospital. Cox regression analysis was used to explore whether ALRI was a risk factor for a worse prognosis in patients with AMI, and a nomogram including ALRI was created to estimate its predictive performance for 28-day mortality.

RESULTS

Based on clinical data from the MIMIC-III database, we found that a high ALRI was closely associated with a variety of clinical parameters. It was an important risk factor for 28-day survival in patients with AMI (HR = 5.816). ALRI had a high predictive power for worse 28-day survival in patients with AMI (area under the curve [AUC] = 0.754). Additionally, we used clinical data from the Wuhan Sixth Hospital to verify the predictive power of ALRI in patients with AMI, and a high level of ALRI remained an independent risk factor for worse survival in patients with AMI (HR = 4.969). The AMI nomogram, including ALRI, displayed a good predictive performance for 28-day mortality in both the MIMIC-III (AUC = 0.826) and Wuhan Sixth Hospital cohorts (AUC = 0.795).

CONCLUSION

The ALRI is closely related to the survival outcomes of patients with newly diagnosed AMI, indicating that it could serve as a novel biomarker for risk stratification such patients.

Correlation of circulating fibroblast growth factor 21 levels with inflammatory factors and the degree of coronary artery stenosis in patients with acute myocardial infarction

BACKGROUND

Fibroblast growth factor 21 (FGF21) is a secreted protein that plays an important role in atherosclerosis and pathological cardiac remodeling. However, the correlation between FGF21 and the degree of coronary artery stenosis and its potential role in acute myocardial infarction (AMI) remain unclear. We examined whether changes in FGF21 levels in AMI correlate with the degree of coronary artery stenosis and the levels of inflammatory factors, and preliminarily investigated the effects of FGF21 on inflammatory factor levels and myocardial injury in rats with AMI.

METHODS

Serum levels of FGF21 and inflammatory factors in the AMI group and control group were measured, and the correlation between FGF21 and clinical indicators and inflammatory factors was analyzed. The effects of FGF21 on cardiac function and inflammatory response were evaluated through echocardiography and measurement of inflammatory factors.

RESULTS

Multivariate logistic regression analysis showed that neutrophil percentage (NEUT%, odds ratio [OR]: 1.232; 95 % confidence interval [CI]: 1.028-1.477; p = 0.024) and FGF21 levels (OR: 2.063; 95 % CI: 1.187-3.586; p = 0.01) had independent effects on AMI. Spearman's rank correlation test showed that FGF21 levels were positively correlated with leukocyte count, NEUT%, neutrophil count, neutrophil to lymphocyte ratio, C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and Gensini scores (p < 0.01), but negatively correlated with lymphocyte count (p < 0.01). FGF21 levels in myocardial tissues and serum levels of FGF21, IL-6, TNF-a, and MCP-1 were significantly higher in AMI rats than in the sham-operated group (p < 0.01). After overexpression of FGF21, serum levels of IL-6, TNF-a, and MCP-1 in rats were significantly decreased (p < 0.01), and cardiac function improved significantly.

CONCLUSIONS

FGF21 levels were independently associated with AMI and may be related to the severity of coronary artery stenosis. Overexpression of FGF21 reduced serum inflammatory factor levels and improved cardiac function in AMI rats.

The m6A methylation enzyme METTL14 regulates myocardial ischemia/reperfusion injury through the Akt/mTOR signaling pathway

Herein, we investigated the role of the m6A methylation enzyme METTL14 in regulating myocardial ischemia/reperfusion injury (IR/I) through the Akt/mTOR signaling pathway and related biological mechanisms. Enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative polymerase chain reaction (qPCR) were performed to detect the m6A mRNA and METTL3, METTL14, WTAP, and KIAA1429 levels in a mouse myocardial IR/I model. An oxygen-glucose deprivation/reperfusion (OGD/R) model was constructed by transfecting neonatal rat cardiomyocytes (NRCM) with METTL14-knockdown lentivirus. METTL14, Bax, and cleaved-caspase3 mRNA expression levels were detected using fluorescence qPCR. Apoptosis was detected using TUNEL staining. After the IR/I surgery following the adeno-associated virus injection, the METTL14 mRNA and apoptosis-related BAX/BCL2 protein expression was detected using fluorescence qPCR and western blotting, respectively. Degree of cell necrosis was detected using an LDH assay. The oxidative stress response of the myocardial tissue was detected, and IL-6 and IL-1β serum levels were detected using ELISAs. The mice injected with METTL14-knockdown AAV9 adeno-associated virus underwent IR/I surgery after the injection of an Akt/mTOR pathway inhibitor (MK2206) into the myocardial layer. Elevated mRNA m6A modification and m6A methyltransferase METTL14 levels were observed in the IR/I-injured mouse heart tissues. METTL14 knockdown significantly inhibited the OGD/R- and IR/I-induced apoptosis and necrosis in cardiac myocytes, inhibited IR/I-induced oxidative stress and inflammatory factor secretion, and activated the Akt/ mTOR pathway in vitro and in vivo. Akt/mTOR pathway inhibition significantly attenuated the alleviating effect of METTL14 knockdown on myocardial IR/I injury-induced apoptosis. Knocking down m6A methylase METTL14 inhibits IR/I-induced myocardial apoptosis and necrosis, inhibits myocardial oxidative stress and secretion of inflammatory cytokines, and activates the Akt/mTOR signaling pathway. Hence, METTL14 regulated myocardial apoptosis and necrosis in mice with IR/I through the Akt/mTOR signaling pathway.

Cellular Alterations in Immune Checkpoint Inhibitor Therapy-Related Cardiac Dysfunction

PURPOSE OF REVIEW

Immune checkpoint inhibitor (ICI) therapy has emerged as a pivotal advancement in cancer treatment, but the widespread adoption has given rise to a growing number of reports detailing significant cardiovascular toxicity. This review concentrates on elucidating the mechanisms behind ICI-related cardiovascular complications, emphasizing preclinical and mechanistic data.

RECENT FINDINGS

Accumulating evidence indicates a more significant role of immune checkpoints in maintaining cardiac integrity than previously understood, and new key scientific data are available to improve our understanding of ICI-related cardiovascular toxicity, including hidden cardiotoxicity. New avenues for innovative concepts are hypothesized, and opportunities to leverage the knowledge from ICI-therapy for pioneering approaches in related scientific domains can be derived from the latest scientific projects. Cardiotoxicity from ICI therapy is a paramount challenge for cardio-oncology. Understanding the underlying effects builds the foundation for tailored cardioprotective approaches in the growing collective at risk for severe cardiovascular complications.

Recent advances in molecular mechanisms of skin wound healing and its treatments

The skin, being a multifaceted organ, performs a pivotal function in the complicated wound-healing procedure, which encompasses the triggering of several cellular entities and signaling cascades. Aberrations in the typical healing process of wounds may result in atypical scar development and the establishment of a persistent condition, rendering patients more vulnerable to infections. Chronic burns and wounds have a detrimental effect on the overall quality of life of patients, resulting in higher levels of physical discomfort and socio-economic complexities. The occurrence and frequency of prolonged wounds are on the rise as a result of aging people, hence contributing to escalated expenditures within the healthcare system. The clinical evaluation and treatment of chronic wounds continue to pose challenges despite the advancement of different therapeutic approaches. This is mainly owing to the prolonged treatment duration and intricate processes involved in wound healing. Many conventional methods, such as the administration of growth factors, the use of wound dressings, and the application of skin grafts, are used to ease the process of wound healing across diverse wound types. Nevertheless, these therapeutic approaches may only be practical for some wounds, highlighting the need to advance alternative treatment modalities. Novel wound care technologies, such as nanotherapeutics, stem cell treatment, and 3D bioprinting, aim to improve therapeutic efficacy, prioritize skin regeneration, and minimize adverse effects. This review provides an updated overview of recent advancements in chronic wound healing and therapeutic management using innovative approaches.

Role of CD4+ T-cells for regulating splenic myelopoiesis and monocyte differentiation after experimental myocardial infarction

Myocardial infarction (MI) induces the generation of proinflammatory Ly6Chigh monocytes in the spleen and the recruitment of these cells to the myocardium. CD4+ Foxp3+ CD25+ T-cells (Tregs) promote the healing process after myocardial infarction by engendering a pro-healing differentiation state in myocardial monocyte-derived macrophages. We aimed to study the effects of CD4+ T-cells on splenic myelopoiesis and monocyte differentiation. We instigated MI in mice and found that MI-induced splenic myelopoiesis is abrogated in CD4+ T-cell deficient animals. Conventional CD4+ T-cells promoted myelopoiesis in vitro by cell-cell-contact and paracrine mechanisms, including interferon-gamma (IFN-γ) signalling. Depletion of regulatory T-cells enhanced myelopoiesis in vivo, as evidenced by increases in progenitor cell numbers and proliferative activity in the spleen 5 days after MI. The frequency of CD4+ T-cells-producing factors that promote myelopoiesis increased within the spleen of Treg-depleted mice. Moreover, depletion of Tregs caused a proinflammatory bias in splenic Ly6Chigh monocytes, which showed predominantly upregulated expression of IFN-γ responsive genes after MI. Our results indicate that conventional CD4+ T-cells promote and Tregs attenuate splenic myelopoiesis and proinflammatory differentiation of monocytes.

The value of D-dimer to lymphocyte ratio in predicting clinical outcomes after percutaneous coronary intervention in ST-segment elevation myocardial infarction patients: A retrospective study

BACKGROUND

D-dimer to lymphocyte ratio (DLR) is a novel composite metric. This study investigated the association between DLR and major adverse cardiovascular events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention.

MATERIALS AND METHODS

This retrospective study included 683 STEMI cases treated between January 2018 and June 2021 at a single center. DLR was calculated for each patient. Receiver operating characteristic curves assessed the predictive value of in-hospital and long-term MACEs, with calculated AUC. Based on the optimal DLR cutoff value, the population was categorized into groups for clinical characteristic analysis. Multivariate logistic and COX regression analyses determined factors independently associated with MACEs. Kaplan-Meier estimation method and log-rank tests assessed event-free survival among different DLR groups. Spearman's test explored the correlation between DLR and Gensini score.

RESULTS

DLR demonstrated an AUC of 0.792 for predicting in-hospital MACEs and 0.708 for long-term MACEs in patients with STEMI. Multivariate logistic regression analysis revealed that a high DLR (cutoff value, 0.47) independently increased the risk of MACEs during hospitalization in patients with STEMI (P = 0.003; odds ratio: 3.015; 95 % CI: 1.438-6.321). Multivariate COX regression showed that a high DLR (cutoff value, 0.34) independently predicted MACEs during long-term follow-up in patients with STEMI (P = 0.011; hazard ratio: 1.724; 95 % CI: 1.135-2.619). Furthermore, DLR exhibited a positive correlation with the Gensini score (P < 0.001).

CONCLUSIONS

DLR is a valuable predictor for MACEs occurrence in patients with STEMI during hospitalization and long-term follow-up after PCI.

Integrative analyses and validation of ferroptosis-related genes and mechanisms associated with cerebrovascular and cardiovascular ischemic diseases

BACKGROUND

There has been a gradual increase in the occurrence of cardiovascular and cerebrovascular ischemic diseases, particularly as comorbidities. Yet, the mechanisms underlying these diseases remain unclear. Ferroptosis has emerged as a potential contributor to cardio-cerebral ischemic processes. Therefore, this study investigated the shared biological mechanisms between the two processes, as well as the role of ferroptosis genes in cardio-cerebral ischemic damage, by constructing co-expression modules for myocardial ischemia (MI) and ischemic stroke (IS) and a network of protein-protein interactions, mRNA-miRNA, mRNA-transcription factors (TFs), mRNA-RNA-binding proteins (RBPs), and mRNA-drug interactions.

RESULTS

The study identified seven key genes, specifically ACSL1, TLR4, ADIPOR1, G0S2, PDK4, HP, PTGS2, and subjected them to functional enrichment analysis during ischemia. The predicted miRNAs were found to interact with 35 hub genes, and interactions were observed between 11 hub genes and 30 TF transcription factors. Additionally, 10 RBPs corresponding to 16 hub genes and 163 molecular compounds corresponding to 30 hub genes were identified. This study also clarified the levels of immune infiltration between MI and IS and different subtypes. Finally, we identified four hub genes, including TLR4, by using a diagnostic model constructed by Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis; ADIPOR1, G0S2, and HP were shown to have diagnostic value for the co-pathogenesis of MI and cerebral ischemia by both validation test data and RT-qPCR assay.

CONCLUSIONS

To the best our knowledge, this study is the first to utilize multiple algorithms to comprehensively analyze the biological processes of MI and IS from various perspectives. The four hub genes, TLR4, ADIPOR1, G0S2, and HP, have proven valuable in offering insights for the investigation of shared injury pathways in cardio-cerebral injuries. Therefore, these genes may serve as diagnostic markers for cardio-cerebral ischemic diseases.

Discordance Between Neutrophil to Lymphocyte Ratio and High Sensitivity C-Reactive Protein to Predict Clinical Events in Patients with Stable Coronary Artery Disease: A Large-Scale Cohort Study

Purpose

Neutrophil to lymphocyte ratio (NLR), a novel inflammatory biomarker, has been shown to positively predict prognosis independent of high-sensitivity C-reactive protein (hsCRP) in patients with coronary artery disease (CAD). This study aimed to use discordance analysis to evaluate the effectiveness of NLR and hsCRP to predict adverse events in patients with stable CAD.

Patients and Methods

This observational cohort study included 7827 consecutive CAD patients at Fuwai Hospital from March 2011 to April 2017. Discordant NLR with hsCRP was defined by the highest quartiles and medians. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCEs), including cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and unplanned revascularization.

Results

During a median 36-month follow-up, 624 (8.0%) MACCEs occurred. Compared with the lowest NLR quartile, a significantly higher risk of MACCEs was observed in the highest NLR quartile after adjusting for confounding factors (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.09-1.71). High NLR and low hsCRP discordance were also associated with an increased risk of MACCEs in the fully adjusted model (HR, 1.39; 95% CI, 1.05-1.84).

Conclusion

This study demonstrated that discordantly elevated NLR levels were associated with a greater risk of adverse clinical events in patients with stable CAD, suggesting the potential clinical significance of NLR as a goal of inflammatory risk management.

miR-182/183-Rasa1 axis induced macrophage polarization and redox regulation promotes repair after ischemic cardiac injury

Few therapies have produced significant improvement in cardiac structure and function after ischemic cardiac injury (ICI). Our possible explanation is activation of local inflammatory responses negatively impact the cardiac repair process following ischemic injury. Factors that can alter immune response, including significantly altered cytokine levels in plasma and polarization of macrophages and T cells towards a pro-reparative phenotype in the myocardium post-MI is a valid strategy for reducing infarct size and damage after myocardial injury. Our previous studies showed that cortical bone stem cells (CBSCs) possess reparative effects after ICI. In our current study, we have identified that the beneficial effects of CBSCs appear to be mediated by miRNA in their extracellular vesicles (CBSC-EV). Our studies showed that CBSC-EV treated animals demonstrated reduced scar size, attenuated structural remodeling, and improved cardiac function versus saline treated animals. These effects were linked to the alteration of immune response, with significantly altered cytokine levels in plasma, and polarization of macrophages and T cells towards a pro-reparative phenotype in the myocardium post-MI. Our detailed in vitro studies demonstrated that CBSC-EV are enriched in miR-182/183 that mediates the pro-reparative polarization and metabolic reprogramming in macrophages, including enhanced OXPHOS rate and reduced ROS, via Ras p21 protein activator 1 (RASA1) axis under Lipopolysaccharides (LPS) stimulation. In summary, CBSC-EV deliver unique molecular cargoes, such as enriched miR-182/183, that modulate the immune response after ICI by regulating macrophage polarization and metabolic reprogramming to enhance repair.

Inflammation in Myocardial Ischemia/Reperfusion Injury: Underlying Mechanisms and Therapeutic Potential

Acute myocardial infarction (MI) occurs when blood flow to the myocardium is restricted, leading to cardiac damage and massive loss of viable cardiomyocytes. Timely restoration of coronary flow is considered the gold standard treatment for MI patients and limits infarct size; however, this intervention, known as reperfusion, initiates a complex pathological process that somewhat paradoxically also contributes to cardiac injury. Despite being a sterile environment, ischemia/reperfusion (I/R) injury triggers inflammation, which contributes to infarct expansion and subsequent cardiac remodeling and wound healing. The immune response is comprised of subsets of both myeloid and lymphoid-derived cells that act in concert to modulate the pathogenesis and resolution of I/R injury. Multiple mechanisms, including altered metabolic status, regulate immune cell activation and function in the setting of acute MI, yet our understanding remains incomplete. While numerous studies demonstrated cardiac benefit following strategies that target inflammation in preclinical models, therapeutic attempts to mitigate I/R injury in patients were less successful. Therefore, further investigation leveraging emerging technologies is needed to better characterize this intricate inflammatory response and elucidate its influence on cardiac injury and the progression to heart failure.

Human peripheral blood mononuclear cells display a temporal evolving inflammatory profile after myocardial infarction and modify myocardial fibroblasts phenotype

Pathophysiological response after acute myocardial infarction (AMI) is described as a three-stage model involving temporal phenotypic modifications of both immune cells and fibroblasts: a primary inflammatory phase, followed by a reparative phase and a fibrous scar maturation phase. Purinergic receptors, particularly the P2Y11 receptor, have been reported to be involved in the regulation of inflammation after ischemia and could act for the resolution of inflammation after AMI. For the first time, we characterized the immuno-inflammatory and P2Y11 expression profiles of peripheral blood mononuclear cells (PBMC) from AMI patients and analyzed the consequences of presenting these cells to cardiac fibroblasts in vitro. PBMC from 178 patients were collected at various times after reperfused ST-segment elevation AMI, from H0 to M12. Expression level of P2RY11 and genes involved in tolerogenic profile of dendritic cells and T cell polarization were evaluated by RT-PCR. P2Y11 protein expression was assessed by flow cytometry. PBMC and human cardiac fibroblasts (HCF) were cocultured and α-SMA/vimentin ratio was analyzed by flow cytometry. Within the first 48 h after AMI, expression levels of HMOX1, STAT3 and CD4 increased while IDO1 and TBX21/GATA3 ratio decreased. Concomitantly, the expression of P2RY11 increased in both T and B cells. In vitro, PBMC collected at H48 after AMI induced an increase in α-SMA/vimentin ratio in HCF. Our results suggest that human PBMC display an evolving inflammatory profile with reparative characteristics the first two days after AMI and secrete soluble mediators leading to the fibroblastic proteins modification, thus participating to myocardial fibrosis.

Transgenic Mice Expressing Functional TCRs Specific to Cardiac Myhc-α 334-352 on Both CD4 and CD8 T Cells Are Resistant to the Development of Myocarditis on C57BL/6 Genetic Background

Myocarditis is a predominant cause of congestive heart failure and sudden death in children and young adolescents that can lead to dilated cardiomyopathy. Lymphocytic myocarditis mediated by T cells can result from the recognition of cardiac antigens that may involve CD4 or CD8 T cells or both. In this report, we describe the generation of T cell receptor (TCR) transgenic mice on a C57BL/6 genetic background specific to cardiac myosin heavy chain (Myhc)-α 334-352 and make the following observations: First, we verified that Myhc-α 334-352 was immunogenic in wild-type C57BL/6 mice and induced antigen-specific CD4 T cell responses despite being a poor binder of IAb; however, the immunized animals developed only mild myocarditis. Second, TCRs specific to Myhc-α 334-352 in transgenic mice were expressed in both CD4 and CD8 T cells, suggesting that the expression of epitope-specific TCR is common to both cell types. Third, although T cells from naïve transgenic mice did not respond to Myhc-α 334-352, both CD4 and CD8 T cells from animals immunized with Myhc-α 334-352 responded to the peptide, indicating that antigen priming is necessary to break tolerance. Fourth, although the transgenic T cells could produce significant amounts of interferon-γ and interleukin-17, the immunized animals developed only mild disease, indicating that other soluble factors might be necessary for developing severe myocarditis. Alternatively, the C57BL/6 genetic background might be a major contributing factor for resistance to the development of myocarditis. Taken together, our model permits the determination of the roles of both CD4 and CD8 T cells to understand the disease-resistance mechanisms of myocarditis in a single transgenic system antigen-specifically.

DNAzyme loaded nano-niosomes attenuate myocardial ischemia/reperfusion injury by targeting apoptosis, inflammation in a NF-κB dependent mechanism

Although DNAzymes have been found to reduce injury after myocardial ischemia/reperfusion (MI/R), their efficiency have been limited due to rapid degradation in vivo. Thus, this study was conducted to extend their half-life by encapsulation into nano‑niosomes and examine their cardioprotective effects in a rat model of myocardial infarction (MI). In order to synthesize nano‑niosomes, surface active agent film hydration method was used. Characterization of nano‑niosomes was performed using the atomic force microscopy (AFM). In order to establish MI/R model in rats, left anterior descending coronary artery (LAD) was ligated for 30 min. A single dose (150µL) of drug formulations was injected into the infarcted region. The cardiac function was evaluated using echocardiography. The expression of pro-inflammatory cytokines, apoptotic factors, and nuclear factor-κB (NF-κB) were evaluated using Western blot and immunohistochemistry, respectively. Particle size of only nano-niosomes was in the range of 60-90 nm, while a shift to 70-110 nm was seen after DNAzyme encapsulation. MI rats treated with DNAzyme‑loaded nano‑niosomes could markedly reduce Bax, caspase3, TNF-α, IL-1β, and NF-κB as well as increase Bcl-2 compared to only MI/R group. Collectively, our finding show that nano‑niosomes can be considered excellent drug delivery platforms to extend half-life and stability of DNAzyme, when it is used to reduce myocardial I/R injury.

Triptolide with hepatotoxicity and nephrotoxicity used in local delivery treatment of myocardial infarction by thermosensitive hydrogel

Myocardial infarction (MI) resulting from coronary artery occlusion is the leading global cause of cardiovascular disability and mortality. Anti-inflammatory treatment plays an important role in MI treatment. Triptolide (TPL), as a Chinese medicine monomer, has a variety of biological functions, including anti-inflammatory, anti-tumor, and immunoregulation. However, it has been proved that TPL is poorly water soluble, and has clear hepatotoxicity and nephrotoxicity, which seriously limits its clinical application. Herein, we designed a long-acting hydrogel platform (TPL@PLGA@F127) for MI treatment by intramyocardial injection. First, we found that the inflammatory response and immune regulation might be the main mechanisms of TPL against MI by network pharmacology. Subsequently, we prepared the hydrogel platform (TPL@PLGA@F127) and tested its effects and toxicity on normal organs in the early stage of MI (3 days after MI-operation). The results showed that TPL@PLGA@F127 could not only promote "repair" macrophages polarization (to M2 macrophage) by day 3 after MI, but also has a long-lasting anti-inflammatory effect in the later stage of MI (28 days after MI-operation). Additionally, we proved that TPL@PLGA@F127 could attenuate the toxicity of TPL by releasing it more slowly and stably. Finally, we observed the long-term effects of TPL@PLGA@F127 on MI and found that it could improve cardiac function, depress the myocardial fibrosis and protect the cardiomyocytes. In summary, this study indicated that TPL@PLGA@F127 could not only enhance the therapeutic effects of TPL on MI, but also attenuate the hepatotoxicity and nephrotoxicity, which established a strong foundation for the clinical application of TPL for MI.

Control of the post-infarct immune microenvironment through biotherapeutic and biomaterial-based approaches

Ischemic heart failure (IHF) is a leading cause of morbidity and mortality worldwide, for which heart transplantation remains the only definitive treatment. IHF manifests from myocardial infarction (MI) that initiates tissue remodeling processes, mediated by mechanical changes in the tissue (loss of contractility, softening of the myocardium) that are interdependent with cellular mechanisms (cardiomyocyte death, inflammatory response). The early remodeling phase is characterized by robust inflammation that is necessary for tissue debridement and the initiation of repair processes. While later transition toward an immunoregenerative function is desirable, functional reorientation from an inflammatory to reparatory environment is often lacking, trapping the heart in a chronically inflamed state that perpetuates cardiomyocyte death, ventricular dilatation, excess fibrosis, and progressive IHF. Therapies can redirect the immune microenvironment, including biotherapeutic and biomaterial-based approaches. In this review, we outline these existing approaches, with a particular focus on the immunomodulatory effects of therapeutics (small molecule drugs, biomolecules, and cell or cell-derived products). Cardioprotective strategies, often focusing on immunosuppression, have shown promise in pre-clinical and clinical trials. However, immunoregenerative therapies are emerging that often benefit from exacerbating early inflammation. Biomaterials can be used to enhance these therapies as a result of their intrinsic immunomodulatory properties, parallel mechanisms of action (e.g., mechanical restraint), or by enabling cell or tissue-targeted delivery. We further discuss translatability and the continued progress of technologies and procedures that contribute to the bench-to-bedside development of these critically needed treatments.

Associations of systemic inflammation markers with myocardial enzymes in pediatric adenotonsillar hypertrophy: A cross-sectional study

Objective

The present study aimed to investigate the relationship between systemic inflammation markers and myocardial enzymes in children with adenotonsillar hypertrophy (ATH).

Methods

The levels of myocardial enzymes were detected and the systemic inflammatory biomarkers including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and systemic immune inflammation index (SII) were calculated. Regression analyses were performed and a prediction model for screening myocardial injury was established by receiver operating characteristic (ROC) curve.

Results

Finally, a total of 804 children with ATH were included. After adjusting for age, BMI, fasting blood glucose and lipid profiles, both NLR and SII were significantly associated with CK-MB (p = 0.041 and 0.034, respectively) and LDH (p = 0.002 and 0.001, respectively), and PLR was associated with CK-MB (p = 0.008). In addition, NLR, SII were independently associated with hyper-LDH [OR = 1.447, 95%CI (1.063, 1.968); OR = 1.001, 95%CI (1.000, 1.002), respectively] and the associations were more significant in girls. A prediction model for hyper-LDH based on SII was developed with the area under the ROC curve of 0.715 (0.682, 0.746).

Conclusion

Systemic inflammation markers were only independently associated with serum hyper-LDH in children with ATH, especially in girls. Further investigation was needed to determine the relationship between systemic inflammation with myocardial enzymes in ATH children.

Exploring an immune cells-related molecule in STEMI by bioinformatics analysis

BACKGROUND

ST-elevated myocardial infarction (STEMI) is the leading cause of mortality worldwide. The mortality rate of heart attacks has decreased due to various preventive factors and the development of early diagnostic resuscitation measures, but the long-term prognosis remains poor. The present study aimed to identify novel serum biomarkers in STEMI patients and explored a possible new mechanism of STEMI from an immune molecular angle with bioinformatics analysis.

METHODS

Gene expression profiles were obtained from Gene Expression Omnibus (GEO) database. Differential gene analysis, machine learning algorithms, gene set enrichment analysis, and immune cell infiltration analysis were conducted using R software.

RESULTS

We identified 146 DEGs (differentially expressed genes) in the integrated dataset between the STEMI and CAD (coronary artery disease) groups. Immune infiltration analysis indicated that eleven cell types were differentially infiltrated. Through correlation analysis, we further screened 25 DEGs that showed a high correlation with monocytes and neutrophils. Afterwards, five genes consistently selected by all three machine learning algorithms were considered candidate genes. Finally, we identified a hub gene (ADM) as a biomarker of STEMI. AUC curves showed that ADM had more than 80% high accuracy in all datasets.

CONCLUSIONS

In this study, we explored a potentially new mechanism of STEMI from an immune molecular perspective, which might provide insights into the pathogenesis of STEMI. ADM positively correlated with monocytes and neutrophils, suggesting its potential role in the immune response during STEMI. Additionally, we validated the diagnostic performance of ADM in two external datasets, which could help to develop new diagnostic tools or therapeutic strategies.

Identification of hub genes and potential ceRNA networks of diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM), a common complication of diabetes, is defined as ventricular dysfunction in the absence of underlying heart disease. Noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), play a crucial role in the development of DCM. Weighted Gene Co-Expression Network Analysis (WGCNA) was used to identify key modules in DCM-related pathways. DCM-related miRNA-mRNA network and DCM-related ceRNA network were constructed by miRNA-seq to identify hub genes in these modules. We identified five hub genes that are associated with the onset of DCM, including Troponin C1 (Tnnc1), Phospholamban (Pln), Fatty acid binding proteins 3 (Fabp3), Popeye domain containing 2 (Popdc2), and Tripartite Motif-containing Protein 63 (Trim63). miRNAs that target the hub genes were mainly involved in TGF-β and Wnt signaling pathways. GO BP enrichment analysis found these miRNAs were involved in the signaling of TGF-β and glucose homeostasis. Q-PCR results found the gene expressions of Pln, Fabp3, Trim63, Tnnc1, and Popdc2 were significantly increased in DCM. Our study identified five hub genes (Tnnc1, Pln, Fabp3, Popdc2, Trim63) whose associated ceRNA networks are responsible for the onset of DCM.

Myocardial ischemia-reperfusion injury; Molecular mechanisms and prevention

Cardiovascular diseases are one of the leading causes of mortality in developed countries. Among cardiovascular disorders, myocardial infarction remains a life-threatening problem predisposing to the development and progression of ischemic heart failure. Ischemia/reperfusion (I/R) injury is a critical cause of myocardial injury. In recent decades, many efforts have been made to find the molecular and cellular mechanisms underlying the development of myocardial I/R injury and post-ischemic remodeling. Some of these mechanisms are mitochondrial dysfunction, metabolic alterations, inflammation, high production of ROS, and autophagy deregulation. Despite continuous efforts, myocardial I/R injury remains a major challenge in medical treatments of thrombolytic therapy, heart disease, primary percutaneous coronary intervention, and coronary arterial bypass grafting. The development of effective therapeutic strategies to reduce or prevent myocardial I/R injury is of great clinical significance.

Bioinformatics and experimental analyses of glutamate receptor and its targets genes in myocardial and cerebral ischemia

BACKGROUND

There is a mutual hemodynamic and pathophysiological basis between the heart and brain. Glutamate (GLU) signaling plays an important role in the process of myocardial ischemia (MI) and ischemic stroke (IS). To further explore the common protective mechanism after cardiac and cerebral ischemic injuries, the relationship between GLU receptor-related genes and MI and IS were analyzed.

RESULTS

A total of 25 crosstalk genes were identified, which were mainly enriched in the Toll-like receptor signaling pathway, Th17 cell differentiation, and other signaling pathways. Protein-protein interaction analysis suggested that the top six genes with the most interactions with shared genes were IL6, TLR4, IL1B, SRC, TLR2, and CCL2. Immune infiltration analysis suggested that immune cells such as myeloid-derived suppressor cells and monocytes were highly expressed in the MI and IS data. Memory B cells and Th17 cells were expressed at low levels in the MI and IS data; molecular interaction network construction suggested that genes such as JUN, FOS, and PPARA were shared genes and transcription factors; FCGR2A was a shared gene of MI and IS as well as an immune gene. Least absolute shrinkage and selection operator logistic regression analysis identified nine hub genes: IL1B, FOS, JUN, FCGR2A, IL6, AKT1, DRD4, GLUD2, and SRC. Receiver operating characteristic analysis revealed that the area under the curve of these hub genes was > 65% in MI and IS for all seven genes except IL6 and DRD4. Furthermore, clinical blood samples and cellular models showed that the expression of relevant hub genes was consistent with the bioinformatics analysis.

CONCLUSIONS

In this study, we found that the GLU receptor-related genes IL1B, FOS, JUN, FCGR2A, and SRC were expressed in MI and IS with the same trend, which can be used to predict the occurrence of cardiac and cerebral ischemic diseases and provide reliable biomarkers to further explore the co-protective mechanism after cardiac and cerebral ischemic injury.

Effectiveness of ozone-laser photodynamic combination therapy for healing wounds infected with methicillin-resistant Staphylococcus aureus in mice

Background and Aim

According to 2013 data from the Ministry of Health of the Republic of Indonesia, there were 8.2% more wounds than typical in Indonesia; 25.4% were open wounds, 70.9% were abrasions and bruises, and 23.2% were lacerations. A wound is defined as damage or loss of body tissue. This study aimed to determine the effectiveness of wound healing using red-laser therapy (650 nm, 3.5 J/cm2), blue-laser therapy (405 nm, 3.5 J/cm2), ozone therapy, red-laser therapy (650 nm, 3.5 J/cm2) with ozone, and blue-laser therapy (405 nm, 3.5 J/cm2) with ozone.

Materials and Methods

One hundred and twelve mice were given incision wounds and infected with methicillin-resistant Staphylococcus aureus (MRSA). The study used a factorial design with two factors: The type of therapy (n = 7) and irradiation time (days 1, 2, 4, and 6). The mice were divided into seven therapy groups: Control group with NaCl, control with Sofra-tulle® treatment, red-laser therapy (650 nm, 3.5 J/cm2), blue-laser therapy (405 nm, 3.5 J/cm2), ozone therapy, red-laser therapy (650 nm, 3.5 J/cm2) with ozone, and blue-laser therapy (405 nm, 3.5 J/cm2) with ozone. This therapy was performed using irradiation perpendicular to the wound area. The photosensitizer used was curcumin 10 mg/mL, which was applied to the wound area before exposure to a laser and ozone. The ozone concentration was 0.011 mg/L with a flow time of 80 s. The test parameters were the number of collagens, bacterial colonies, lymphocytes, monocytes, and wound length measurement to determine their acceleration effects on wound healing. Data were analyzed by a two-way (factorial) analysis of variance test.

Results

Acceleration of wound healing was significantly different between treatments with a laser or a laser-ozone combination and treatment using 95% sodium chloride (NaCl) and Sofra-tulle®. On day 6, the blue-laser with ozone treatment group had efficiently increased the number of bacteria and reduced the wound length, and the red-laser treatment with ozone increased the amount of collagen. In addition, the red-laser also reduced the number of lymphocytes and monocytes, which can have an impact on accelerating wound healing. Blue-laser therapy was very effective for increasing the number of epithelia.

Conclusion

The blue- and red-laser combined with ozone treatments effectively accelerated the healing of incisional wounds infected with MRSA bacteria.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

The multifaceted nature of endogenous cardiac regeneration

Since the first evidence of cardiac regeneration was observed, almost 50 years ago, more studies have highlighted the endogenous regenerative abilities of several models following cardiac injury. In particular, analysis of cardiac regeneration in zebrafish and neonatal mice has uncovered numerous mechanisms involved in the regenerative process. It is now apparent that cardiac regeneration is not simply achieved by inducing cardiomyocytes to proliferate but requires a multifaceted response involving numerous different cell types, signaling pathways and mechanisms which must all work in harmony in order for regeneration to occur. In this review we will endeavor to highlight a variety of processes that have been identifed as being essential for cardiac regeneration.

XCR1+ conventional dendritic cell-induced CD4+ T helper 1 cell activation exacerbates cardiac remodeling after ischemic myocardial injury

Cardiac remodeling has no established therapies targeting inflammation. CD4⁺ T-cell subsets have been reported to play significant roles in healing process after ischemic myocardial injury, but their detailed mechanisms of activation remain unknown. To explore immune reactions during cardiac remodeling, we applied a non-surgical model of coronary heart disease (CHD) induced by a high-fat diet (HFD-CHD) in SR-BI^-/-/ApoeR61^h/h mice. Flow cytometry analyses throughout the period of progressive cardiac dysfunction revealed that CD4⁺ T Helper 1 (Th1) cells were predominantly activated in T-cell subsets. Probucol was reported to attenuate cardiac dysfunction after coronary artery ligation model (ligation-MI) in rats. To determine whether probucol suppress cardiac remodeling after HFD-CHD, we treated SR-BI^-/-/ApoeR61^h/h mice with probucol. We found treatment with probucol in HFD-CHD mice reduced cardiac dysfunction, with attenuated activation of Th1 cells. RNA-seq analyses revealed that probucol suppressed the expression of CXCR3, a Th1-related chemokine receptor, in the heart. XCR1⁺ cDC1 cells, which highly expresses the CXCR3 ligands CXCL9 and CXCL10, were predominantly activated after HFD-CHD. XCR1⁺ cDC1 lineage skewing of pre-DC progenitors was observed in bone marrow, with subsequent systemic expansion of XCR1⁺ cDC1 cells after HFD-CHD. Activation of CXCR3⁺ Th1 cell and XCR1⁺ cDC1 cells was also observed in ligation-MI. Notably, post-MI depletion of XCR1⁺ cDC1 cells suppressed CXCR3⁺ Th1 cell activation and prevented cardiac dysfunction. In patient autopsy samples, CXCR3⁺ Th1 and XCR1⁺ cDC1 cells infiltrated the infarcted area. In this study, we identified a critical role of XCR1⁺ cDC1-activated CXCR3⁺ Th1 cells in ischemic cardiac remodeling.

Inhibition of thrombin on endothelium enhances recruitment of regulatory T cells during IRI and when combined with adoptive Treg transfer, significantly protects against acute tissue injury and prolongs allograft survival

Ischemia-reperfusion injury (IRI) amplifies T cell alloimmune responses after transplantation with thrombin playing a key pro-inflammatory role. To explore the influence of thrombin on regulatory T cell recruitment and efficacy we used a well-established model of IRI in the native murine kidney. Administration of the cytotopic thrombin inhibitor PTL060 inhibited IRI, and by skewing expression of chemokines (reducing CCL2 and CCL3 but increasing CCL17 and CCL22) increased the infiltration of M2 macrophages and Tregs. When PTL060 was combined with infusion of additional Tregs, these effects were further amplified. To test the benefits of thrombin inhibition in a transplant model, BALB/c hearts were transplanted into B6 mice with or without perfusion with PTL060 in combination with Tregs. Thrombin inhibition or Treg infusion alone led to small increments in allograft survival. However, the combined therapy led to modest graft prolongation by the same mechanisms as in renal IRI; graft survival was accompanied by increased numbers of Tregs and anti-inflammatory macrophages, and reduced expression of pro-inflammatory cytokines. While the grafts succumbed to rejection associated with the emergence of alloantibody, these data suggest that thrombin inhibition within the transplant vasculature enhances the efficacy of Treg infusion, a therapy that is currently entering the clinic to promote transplant tolerance.

The role of major immune cells in myocardial infarction

Myocardial infarction (MI) is a cardiovascular disease (CVD) with high morbidity and mortality worldwide, often leading to adverse cardiac remodeling and heart failure, which is a serious threat to human life and health. The immune system makes an important contribution to the maintenance of normal cardiac function. In the disease process of MI, necrotic cardiomyocytes release signals that activate nonspecific immunity and trigger the action of specific immunity. Complex immune cells play an important role in all stages of MI progression by removing necrotic cardiomyocytes and tissue and promoting the healing of damaged tissue cells. With the development of biomaterials, cardiac patches have become an emerging method of repairing MI, and the development of engineered cardiac patches through the construction of multiple animal models of MI can help treat MI. This review introduces immune cells involved in the development of MI, summarizes the commonly used animal models of MI and the newly developed cardiac patch, so as to provide scientific reference for the accurate diagnosis and effective treatment of MI.

T-Cell Mineralocorticoid Receptor Deficiency Attenuates Pathologic Ventricular Remodelling After Myocardial Infarction

BACKGROUND

Mineralocorticoid receptor (MR) antagonists have been widely used to treat heart failure (HF). Studies have shown that MR in T cells plays important roles in hypertension and myocardial hypertrophy. However, the function of T-cell MR in myocardial infarction (MI) has not been elucidated.

METHODS

In this study, we used T-cell MR knockout (TMRKO) mouse to investigate the effects of T-cell MR deficiency on MI and to explore the underlying mechanisms. Echocardiography and tissue staining were used to assess cardiac function, fibrosis, and myocardial apoptosis after MI. Flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect immune cell infiltration and inflammation.

RESULTS

T-cell MR deficiency significantly improved cardiac function, promoted myocardial repair, and inhibited myocardial apoptosis, fibrosis, and inflammation after MI. Luminex assays revealed that TMRKO mice had significantly lower levels of interferon-gamma (IFN-γ) and interleukin-6 (IL-6) in serum and infarcted myocardium than littermate control mice. In cultured splenic T cells, MR deficiency suppressed IL-6 expression, whereas MR overexpression enhanced IL-6 expression. Chromatin immunoprecipitation (ChIP) assay demonstrated that MR bound to the MR response element on the promoter of IL-6 gene. Finally, T-cell MR deficiency significantly suppressed accumulation of macrophages in infarcted myocardium and differentiation of proinflammatory macrophages, thereby alleviating the consequences of MI.

CONCLUSIONS

T-cell MR deficiency improved pathologic ventricular remodelling after MI, likely through inhibition of accumulation and differentiation of proinflammatory macrophages. At the molecular level, MR may work through IFN-γ and IL-6 in T cells to exert functions in MI.

The cardiac wound healing response to myocardial infarction

Myocardial infarction (MI) is defined as evidence of myocardial necrosis consistent with prolonged ischemia. In response to MI, the myocardium undergoes a series of wound healing events that initiate inflammation and shift to anti-inflammation before transitioning to tissue repair that culminates in scar formation to replace the region of the necrotic myocardium. The overall response to MI is determined by two major steps, the first of which is the secretion of proteases by infiltrating leukocytes to breakdown extracellular matrix (ECM) components, a necessary step to remove necrotic cardiomyocytes. The second step is the generation of new ECM that comprises the scar; and this step is governed by the cardiac fibroblasts as the major source of new ECM synthesis. The leukocyte component resides in the middle of the two-step process, contributing to both sides as the leukocytes transition from pro-inflammatory to anti-inflammatory and reparative cell phenotypes. The balance between the two steps determines the final quantity and quality of scar formed, which in turn contributes to chronic outcomes following MI, including the progression to heart failure. This review will summarize our current knowledge regarding the cardiac wound healing response to MI, primarily focused on experimental models of MI in mice. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Immune System Diseases > Molecular and Cellular Physiology.

Heart Failure in Chronic Infectious and Inflammatory Conditions: Mechanistic Insights from Clinical Heterogeneity

PURPOSE OF REVIEW

The balance between inflammation and its resolution plays an important and increasingly appreciated role in heart failure (HF) pathogenesis. In humans, different chronic inflammatory conditions and immune-inflammatory responses to infection can lead to diverse HF manifestations. Reviewing the phenotypic and mechanistic diversity of these HF presentations offers useful clinical and scientific insights.

RECENT FINDINGS

HF risk is increased in patients with chronic inflammatory and autoimmune disorders and relates to disease severity. Inflammatory condition-specific HF manifestations exist and underlying pathophysiologic causes may differ across conditions. Although inflammatory disease-specific presentations of HF differ, chronic excess in inflammation and auto-inflammation relative to resolution of this inflammation is a common underlying contributor to HF. Further studies are needed to phenotypically refine inflammatory condition-specific HF pathophysiologies and prognoses, as well as potential targets for intervention.

Bone marrow-derived naïve B lymphocytes improve heart function after myocardial infarction: a novel cardioprotective mechanism for empagliflozin

The role of adaptive immunity in myocardial recovery post myocardial infarction (MI), particularly the immune response by B lymphocytes, remains elusive. Bone marrow immune microenvironment in response to MI is remotely regulated by the hypothalamic pituitary adrenal (HPA) axis. We utilized the cardioprotective actions of SGLT2 inhibitor to identify and characterize bone marrow B cell subsets that respond to myocardial injury. Initially, we preformed ligation of left anterior descendant (LAD) coronary artery in male C57BL/6J mice to monitor the dynamic changes of immune cells across tissues. Mechanistic insights from mouse models demonstrated arrest of bone marrow B cell maturation and function 24 h post MI. A secondary MI model (twice MIs) in mice was established for the first time to evaluate the dosage-dependent cardioprotection of empagliflozin (EMPA). Single-cell RNA-Seq further demonstrated that EMPA restored bone marrow naïve B cell (B220⁺CD19⁺CD43^-IgM⁺IgD⁺) counts and function. Additionally, we recruited 14 acute MI patients with single LAD disease, and profiled B cells post percutaneous coronary intervention (PCI) (compared to 18 matched no-MI controls). We revealed a positive correlation of increased B cell counts with enhanced ejection fraction in MI patients with PCI while lymphopenia was associated with patients with heart failure. Mechanistically, MI triggers the release of glucocorticoids from neuroendocrine system, inducing NHE1-mediated autophagic death of bone marrow B cells while repressing B cell progenitor proliferation and differentiation. Infusion of B cells derived from bone marrow significantly improved cardiac function and diminished infarct size post MI. These findings provide new mechanistic insights into regulation of adaptive immune response post MI, and support targeting bone marrow B cell development for improved ventricular remodeling and reduced heart failure after MI.

Identification of potential biomarkers and immune-related pathways related to immune infiltration in patients with acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI), a medical condition caused by the ischemic necrosis of cardiac tissues, is due to sudden occlusion of the coronary arteries in patients including transplant recipients. It is the leading reason for death and disability worldwide. This study aimed to search potential biomarkers related to the progression of AMI and identify the related immune-related pathways, as also examine their association with the immune cell infiltration and diagnostic value for AMI.

METHODS

Datasets of gene microarray were extracted from (www.ncbi.nlm.nih.gov/geo) the Gene Expression Omnibus (GEO) database and AMI-related biomarkers were obtained by differential expression analysis and weighted correlation network analysis (WGCNA). Subsequently, the support vector machine-recursive feature elimination (SVM-RFE) and the least absolute shrinkage and selection operator (LASSO) regression analyses were used to mine AIM-related hub markers. For the assessment of the diagnostic value of these markers for AMI, the receiver operator characteristic (ROC) curves were plotted. Additionally, the single-sample gene set enrichment analysis (ssGSEA) was performed to determine the immune cell infiltration.

RESULTS

A total of 1273 differentially expressed genes (DEGs) were obtained. Nine co-expression modules were obtained after WGCNA. Among them, the brown-colored module was identified as the hub for AMI (correlation [cor] = 0.73, P = 1.1e-87), and intersected with the DEGs yielded a total of 88 shared genes. Subsequently, five hub genes were obtained from the analysis of the LASSO regression and SVM-RFE algorithm. Ultimately, using the ROC curves, the diagnostic values of these genes for AMI were confirmed. The five hub genes were also found to be significantly associated with the infiltration levels of multiple immune cells. Moreover, the DEGs were mainly enriched in the inflammatory and immune-related gene sets evidenced by the functional enrichment analysis.

CONCLUSION

The five hub genes may serve as potential markers for AMI diagnosis and the findings have implications for further investigations on the molecular mechanisms underlying AMI.

Anti-inflammatory effect of trans-anethol in a rat model of myocardial ischemia-reperfusion injury

Myocardial ischemia‑reperfusion injury (MI/R) is considered a main risk factor for global cardiac mortality and morbidity, for which no effective treatment exists. Both inflammation and epigenetic regulation play a pivotal role in the early stage of MI/R. The present study aimed at investigating the prospective anti-inflammatory role of trans-anethole (TNA) in targeting MI/R and its related mechanism in upregulating the expression of the inflammatory and cardiac-related gene (VAV3), and its epigenetic regulators (lncRNA-JRKL-AS1 and miR-1298) that were retrieved from in-silico data analysis in an ischemia/reperfusion (I/R) rat model.

MATERIALS & METHODS

TNA was administered in 3 doses (50, 100, and 200 mg/kg), 15 min prior to coronary ligation in male Wistar rats. The left ventricular end-diastolic pressure and dP/dtmax were assessed. Histopathological, biochemical, and molecular analyses were performed to assess the effects of TNA pre-treatment on the I/R rats model.

RESULTS

TNA alleviated the I/R-induced cardiac injury pathologically and improved the cardiac function tests and enzymes. At the molecular level, TNA upregulated the expression level of the retrieved RNA-based panel (VAV3 mRNA/miR-1298/lncRNA JRKL-AS1). At the protein level, TNA decreased the cardiac content of the pro-inflammatory cytokine TNF-α.

CONCLUSION

TNA has demonstrated a potential ability to alleviate the cardiac injury and attenuate the inflammatory response following ischemia-reperfusion in the rat model through modulation of the expression of RNA panel (VAV3 mRNA/miR-1298/lncRNA JRKL-AS1) and TNF- α protein.