Cytokine gene expression after myocardial infarction in rat hearts: possible implication in left ventricular remodeling

The Elevated Inflammatory Status of Neutrophils Is Related to In-Hospital Complications in Patients with Acute Coronary Syndrome and Has Important Prognosis Value for Diabetic Patients

Despite neutrophil involvement in inflammation and tissue repair, little is understood about their inflammatory status in acute coronary syndrome (ACS) patients with poor outcomes. Hence, we investigated the potential correlation between neutrophil inflammatory markers and the prognosis of ACS patients with/without diabetes and explored whether neutrophils demonstrate a unique inflammatory phenotype in patients experiencing an adverse in-hospital outcome. The study enrolled 229 ACS patients with or without diabetes. Poor evolution was defined as either death, left ventricular ejection fraction (LVEF) <40%, Killip Class 3/4, ventricular arrhythmias, or mechanical complications. Univariate and multivariate analyses were employed to identify clinical and paraclinical factors associated with in-hospital outcomes. Neutrophils isolated from fresh blood were investigated using qPCR, Western blot, enzymatic assay, and immunofluorescence. Poor evolution post-myocardial infarction (MI) was associated with increased number, activity, and inflammatory status of neutrophils, as indicated by significant increase of Erythrocyte Sedimentation Rate (ESR), C-reactive protein (CRP), fibrinogen, interleukin-1β (IL-1β), and, interleukin-6 (IL-6). Among the patients with complicated evolution, neutrophil activity had an important prognosis value for diabetics. Neutrophils from patients with unfavorable evolution revealed a pro-inflammatory phenotype with increased expression of CCL3, IL-1β, interleukin-18 (IL-18), S100A9, intracellular cell adhesion molecule-1 (ICAM-1), matrix metalloprotease (MMP-9), of molecules essential in reactive oxygen species (ROS) production p22phox and Nox2, and increased capacity to form neutrophil extracellular traps. Inflammation is associated with adverse short-term prognosis in acute ACS, and inflammatory biomarkers exhibit greater specificity in predicting short-term outcomes in diabetics. Moreover, neutrophils from patients with unfavorable evolution exhibit distinct inflammatory patterns, suggesting that alterations in the innate immune response in this subgroup may exert detrimental effects on disease progression.

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

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

Novel portable hypothermic machine perfusion preservation device enhances cardiac viability of donated human hearts

Introduction

Heart transplant remains the gold standard treatment for patients with advanced heart failure. However, the list of patients waiting for a heart transplant continues to increase. We have developed a portable hypothermic oxygenated machine perfusion device, the VP.S ENCORE®, to extend the allowable preservation time. The purpose of this study was to test the efficacy of the VP.S. ENCORE® using deceased donors derived hearts.

Methods

Hearts from brain-dead donors not utilized for transplant (n = 11) were offered for research from the Texas Organ Sharing Alliance (TOSA), South and Central Texas' Organ Procurement Organization (OPO) and were preserved in the VP.S ENCORE® for 4 (n = 2), 6 (n = 3), and 8 (n = 3) hours or were kept in static cold storage (SCS) (n = 3). After preservation, the hearts were placed in an isolated heart Langendorff model for reperfusion and evaluated for cardiac function.

Results

The mean donor age was 37.82 ± 12.67 with the youngest donor being 19 and the oldest donor being 58 years old. SCS hearts mean weight gain (%) was -1.4 ± 2.77, while perfused at 4 h was 5.6 ± 6.04, perfused at 6 h 2.1 ± 6.04, and 8 h was 7.2 ± 10.76. Venous and arterial lactate concentrations were less than 2.0 mmol/L across all perfused hearts. Left ventricular contractility (+dPdT, mmHg/s) for 4 h (1,214 ± 1,064), 6 (1,565 ± 141.3), and 8 h (1,331 ± 403.6) were within the range of healthy human heart function. Thus, not significant as compared to the SCS group (1,597 ± 342.2). However, the left ventricular relaxation (mmHg/s) was significant in 6-hour perfused heart (p < 0.05) as compared to SCS. Gene expression analysis of inflammation markers (IL-6, IL-1β) showed no significant differences between SCS and perfused hearts, but a 6-hour perfusion led to a downregulated expression of these markers.

Discussion

The results demonstrate that the VP.S ENCORE® device enhances cardiac viability and exhibits comparable cardiac function to a healthy heart. The implications of these findings suggest that the VP.S ENCORE® could introduce a new paradigm in the field of organ preservation, especially for marginal hearts.

Association of the TNF-α-308G>A gene polymorphism with left ventricular geometry and functional abnormalities in obstructive sleep apnea subjects

OBJECTIVE

Tumor necrosis factor-α (TNF-α) can induce left ventricular remodeling. In this study, we investigated whether the TNF-α-308G>A polymorphism is associated with left ventricular geometry (LVG) and left ventricular functional abnormalities in obstructive sleep apnea (OSA) subjects.

METHODS

Two hundred and seventy-eight subjects were enrolled. Echocardiography and genetic data were assessed in all patients. Geometric patterns of the left ventricle were determined from the relative wall thickness and left ventricular mass index (LVMI). Genetic analysis for the TNF-α-308G>A SNP rs1800629 was identified by Sanger sequencing. The correlations of the TNF-α-308G>A polymorphism with LVG and left ventricular function were analyzed by difference analysis and logistic regression.

RESULTS

The chi-square test showed that there were differences in genotype distributions among the four groups (p = 0.033), such that the frequency of GA+AA genotypes was significantly higher in the concentric hypertrophy group than in the normal geometry group (p < 0.05). Independent sample T tests showed that the GA+AA genotypes had higher IVST, LVPWT, LVMI, E/e' values, and lower e' values than those of the GG genotype (p < 0.05). Logistic regression analysis showed that the TNF-α-308G>A polymorphism was independently correlated with eccentric hypertrophy (OR = 2.456, p = 0.047) and concentric hypertrophy (OR = 2.456, p = 0.047).

CONCLUSION

In OSA patients, the TNF-α-308G>A polymorphism was linked to LVG and abnormal left ventricular diastolic function, suggesting that the TNF-α-308G>A polymorphism may have an important influence on LVG alterations.

Review of the Association Between Long-Term and Current Systemic Steroid Use With Electromechanical Complications and Inpatient Mortality After ST-Elevation Myocardial Infarction

Background The impact of long-term systemic steroid use on electrical and mechanical complications following ST-segment elevation myocardial infarction (STEMI) has not been extensively studied. Methods In a retrospective cohort study of the National Inpatient Sample (NIS) from 2018 to 2020, adults admitted with STEMI were dichotomized based on the presence of long-term (current) systemic steroid (LTCSS) use. The primary outcome was all-cause mortality. Secondary outcomes included a composite of mechanical complications, electrical, hemodynamic, and thrombotic complications, as well as revascularization complexity, length of stay (LOS), and total charge. Multivariate linear and logistic regressions were used to adjust for confounders. Results Out of 608,210 admissions for STEMI, 5,310 (0.9%) had LTCSS use. There was no significant difference in the odds of all-cause mortality (aOR: 0.89, 95%CI: 0.74-1.08, p-value: 0.245) and the composite of mechanical complications (aOR: 0.74, 95%CI: 0.25-2.30, p-value: 0.599). LTCSS use was associated with lower odds of ventricular tachycardia, atrioventricular blocks, new permanent-pacemaker insertion, cardiogenic shock, the need for mechanical circulatory support, mechanical ventilation, cardioversion, a reduced LOS by 1 day, and a reduced total charge by 34,512 USD (all p-values: <0.05). There were no significant differences in the revascularization strategy (coronary artery bypass graft (CABG) vs. percutaneous coronary interventions (PCI)) or in the incidence of composite thrombotic events. Conclusion LTCSS use among patients admitted with STEMI was associated with lower odds of electrical dysfunction and hemodynamic instability but no difference in the odds of mechanical complications, CABG rate, all-cause mortality, cardiac arrest, or thrombotic complications. Further prospective studies are needed to evaluate these findings further.

Atherosclerosis Associated With COVID-19: Acute, Tends to Severely Involve Peripheral Arteries, and May be Reversible

Arterial stiffness was reported with corona virus disease 2019 (COVID-19). We studied atherosclerosis in COVID-19 directly through duplex ultrasound measurements and their relation to co-morbidities, clinical and laboratory severity markers, and serum interleukin (IL) 6 and 17. Serum IL 6 and 17, average carotid intima-media thickness (cIMT), diameter and peak systolic velocities (PSV) of tibial, ulnar, radial arteries, and ankle brachial index (ABI) were measured in 44 COVID-19 patients and 44 healthy controls. Serum IL6, IL17, PSV, and cIMT were higher while diameter was lower (P ≤ .01) in cases. Clinical severity index correlated positively with age, co-morbidities, ferritin, IL6, IL17, cIMT, and PSV (P ≤ .04) and negatively with diameter and ABI (P = .04). Patients with severe lymphopenia had higher PSV, IL6, and IL17 and lower diameter (P < .00001). Ferritin positively correlated with PSV and negatively with diameter and ABI (P ≤ .01). Those who received an IL6 inhibitor (tocilizumab) showed lower PSV and higher diameter (P ≤ .01). In multiple regression analysis, IL17 and (age, co-morbidities) were related to (PSV, diameter) and cIMT (P ≤ .001, ≤0.02), respectively. COVID-19 may be associated with subclinical acute and may be reversible atherosclerosis severely involving peripheral arteries.

Nuclear Factor-κB is a Prime Candidate for the Diagnosis and Control of Inflammatory Cardiovascular Disease

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is responsible for the regulation of genes involved in inflammation and immune responses. NF-κB may play an important role in cardiovascular diseases (CVDs), atherosclerosis and diabetes. Several therapeutic agents used for the treatment of CVDs and diabetes, such as pimobendan and sodium-glucose cotransporter 2 inhibitors, exert anti-inflammatory effects by inhibiting NF-κB activation; anti-inflammatory therapy may have beneficial effects in CVDs and diabetes. Several pharmacological agents and natural compounds may inhibit NF-κB, and these agents alone or in combination may be used to treat various inflammatory diseases. Immunoglobulin-free light chains could be surrogate biomarkers of NF-κB activation and may be useful for evaluating the efficacy of these agents. This review discusses recent advances in our understanding of how the NF-κB signalling pathway controls inflammation, metabolism and immunity, and how improved knowledge of these pathways may lead to better diagnostics and therapeutics for various human diseases.

Dynamic Involvement of Telocytes in Modulating Multiple Signaling Pathways in Cardiac Cytoarchitecture

Cardiac interstitium is a complex and dynamic environment, vital for normal cardiac structure and function. Telocytes are active cellular players in regulating main events that feature myocardial homeostasis and orchestrating its involvement in heart pathology. Despite the great amount of data suggesting (microscopically, proteomically, genetically, etc.) the implications of telocytes in the different physiological and reparatory/regenerative processes of the heart, understanding their involvement in realizing the heart's mature cytoarchitecture is still at its dawn. Our scrutiny of the recent literature gave clearer insights into the implications of telocytes in the WNT signaling pathway, but also TGFB and PI3K/AKT pathways that, inter alia, conduct cardiomyocytes differentiation, maturation and final integration into heart adult architecture. These data also strengthen evidence for telocytes as promising candidates for cellular therapies in various heart pathologies.

Acupuncture at Neiguan suppresses PVCs occurring post-myocardial infarction by alleviating inflammation and fibrosis

Background

Acupuncture at Neiguan (PC6) has long been used for treating cardiovascular diseases, but its antiarrhythmic effect and the underlying mechanisms have not yet been well investigated, especially regarding premature ventricular complexes (PVCs) that occur post-myocardial infarction (MI). The purpose of this study was to study the antiarrhythmic effect of manual acupuncture applied to PC6 for a relatively long period (28 days) and to elucidate the mechanism in mice.

Methods

An MI mouse model was generated by ligating the left anterior descending coronary artery in male C57/BL6 mice (n = 31). Manual acupuncture at PC6 was applied seven times weekly for 4 weeks. The state of myocardial injury was characterized by electrocardiography (ECG) and echocardiography. Inflammation was detected by ELISA and immunohistochemical stanning. Fibrosis was evaluated by Masson’s trichrome staining. RNA sequencing was used to explore the differentially expressed genes (DEGs) among the different groups after treatment.

Results

Acupuncture at PC6 lowered the incidence of spontaneous PVCs after MI injury (1/9, 11%) compared to that in mice without acupuncture treatment (6/9, 67%) and improved the ejection fraction from 31.77% in the MI mice to 44.18% in the MI + PC6 mice. Fibrosis was reduced after PC6 treatment. RNA-seq showed many DEGs involved in the immune system and inflammatory response pathway. Further studies confirmed that inflammation at the circulation level and cardiac tissue was inhibited in MI + PC6 mice, accompanied by suppressed sympathetic activation.

Conclusions

In conclusion, 28-day treatment of acupuncture at PC6 reduced spontaneous PVCs and improved systolic function, possibly by suppressing inflammatory response-mediated fibrosis and sympathetic hyperactivity.

Emerging Roles of Inflammasomes in Cardiovascular Diseases

Cardiovascular diseases are known as the leading cause of morbidity and mortality worldwide. As an innate immune signaling complex, inflammasomes can be activated by various cardiovascular risk factors and regulate the activation of caspase-1 and the production and secretion of proinflammatory cytokines such as IL-1β and IL-18. Accumulating evidence supports that inflammasomes play a pivotal role in the progression of atherosclerosis, myocardial infarction, and heart failure. The best-known inflammasomes are NLRP1, NLRP3, NLRC4, and AIM2 inflammasomes, among which NLRP3 inflammasome is the most widely studied in the immune response and disease development. This review focuses on the activation and regulation mechanism of inflammasomes, the role of inflammasomes in cardiovascular diseases, and the research progress of targeting NLRP3 inflammasome and IL-1β for related disease intervention.

Spironolactone alleviates myocardial fibrosis via inhibition of Ets‑1 in mice with experimental autoimmune myocarditis

Spironolactone improves cardiac structure, function and prognosis in patients with heart failure and delays the progression of cardiac fibrosis. However, the exact underlying mechanism of this process remains to be elucidated. The present study therefore aimed to explore the protective effect and underlying mechanism of the aldosterone receptor antagonist, spironolactone, on myocardial fibrosis in mice with experimental autoimmune myocarditis (EAM). The EAM model was induced in BALB/c mice via immunization with murine cardiac α-myosin heavy chain sequence polypeptides. The cardiac function of the mice was assessed using echocardiography and the levels of inflammatory cytokines were quantified using ELISA. E26 transformation-specific sequence-1 (Ets-1) expression was knocked down using lentivirus-mediated small interference RNA. Total collagen deposition was assessed using Masson's trichrome and Ets-1, TGF-β1, Smad2/3, collagen I and III protein expression levels were detected using immunohistochemistry and western blotting. MMP-2 and MMP-9 mRNA expression levels and activity was determined using reverse transcription-quantitative PCR and gelatin zymography, respectively. The results of the present study demonstrated that spironolactone significantly improved myocardium hypertrophy, diastolic cardiac function and decreased myocardial inflammation and collagen deposition induced by EAM. Spironolactone treatment significantly inhibited Ets-1 and smad2/3 phosphorylation. In addition, inhibition of Ets-1 reduced the expression and activity of MMP-2 and MMP-9 and decreased cardiac fibrosis in EAM mice. The results indicated that the improvement of myocardial fibrosis by spironolactone may be associated with the TGF-β1/Smad-2/3/Ets-1 signaling pathway in EAM mice.

Effect of n-3 PUFA on left ventricular remodelling in chronic heart failure: a systematic review and meta-analysis

Accumulating evidence suggests that supplementation of n-3 PUFA was associated with reduction in risk of major cardiovascular events. This meta-analysis was to systematically evaluate whether daily supplementation and accumulated intake of n-3 PUFA are associated with improved left ventricular (LV) remodelling in patients with chronic heart failure (CHF). Articles were obtained from Pubmed, Clinical key and Web of Science from inception to January 1 in 2021, and a total of twelve trials involving 2162 participants were eligible for inclusion. The sources of study heterogeneity were explained by I2 statistic and subgroup analysis. Compared with placebo groups, n-3 PUFA supplementation improved LV ejection fraction (LVEF) (eleven trials, 2112 participants, weighted mean difference (WMD) = 2·52, 95 % CI 1·25, 3·80, I2 = 87·8 %) and decreased LV end systolic volume (five studies, 905 participants, WMD = -3·22, 95 % CI 3·67, -2·77, I2 = 0·0 %) using the continuous variables analysis. Notably, the high accumulated n-3 PUFA dosage groups (≥ 600 g) presented a prominent improvement in LVEF, while the low and middle accumulated dosage (≤ 300 and 300-600 g) showed no effects on LVEF. In addition, n-3 PUFA supplementation decreased the levels of pro-inflammatory mediators including TNF-α, IL-6 (IL-6) and hypersensitive c-reactive protein. Therefore, the present meta-analysis demonstrated that n-3 PUFA consumption was associated with a substantial improvement of LV function and remodelling in patients subjected to CHF. The accumulated dosage of n-3 PUFA intake is vital for its cardiac protective role.

Targeting Inflammation in the Diagnosis, Management, and Prevention of Cardiovascular Diseases

Inflammation plays an important role in the development and progression of cardiovascular diseases (CVDs). Hypertension and hyperlipidemia are the key risk factors of CVDs and induce inflammation in the heart and vessels. Unhealthy diet, infection, and smoking coupled with genetic factors lead to the development of CVDs as well as induce inflammation. Risk factors of CVDs such as hypertension and hyperlipidemia along with diabetes activate nuclear factor kappa B, which regulates the transcription of immunoglobulin free light chain (FLC) κ in B cells and the production of multiple inflammatory molecules, leading to inflammation. FLCs are novel biomarkers of inflammation, and their levels have been associated with overall mortality in a general population and with cardiovascular outcomes. In this review, the role of inflammation in the pathogenesis of CVDs, new biomarkers of inflammation, and dietary options counterbalancing inflammatory processes, such as the polyphenol-rich French maritime pine bark extract Pycnogenol, are discussed.

Mechano-chemo signaling interactions modulate matrix production by cardiac fibroblasts

Extracellular matrix remodeling after myocardial infarction occurs in a dynamic environment in which local mechanical stresses and biochemical signaling species stimulate the accumulation of collagen-rich scar tissue. It is well-known that cardiac fibroblasts regulate post-infarction matrix turnover by secreting matrix proteins, proteases, and protease inhibitors in response to both biochemical stimuli and mechanical stretch, but how these stimuli act together to dictate cellular responses is still unclear. We developed a screen of cardiac fibroblast-secreted proteins in response to combinations of biochemical agonists and cyclic uniaxial stretch in order to elucidate the relationships between stretch, biochemical signaling, and cardiac matrix turnover. We found that stretch significantly synergized with biochemical agonists to inhibit the secretion of matrix metalloproteinases, with stretch either amplifying protease suppression by individual agonists or antagonizing agonist-driven upregulation of protease expression. Stretch also modulated fibroblast sensitivity towards biochemical agonists by either sensitizing cells towards agonists that suppress protease secretion or de-sensitizing cells towards agonists that upregulate protease secretion. These findings suggest that the mechanical environment can significantly alter fibrosis-related signaling in cardiac fibroblasts, suggesting caution when extrapolating in vitro data to predict effects of fibrosis-related cytokines in situations like myocardial infarction where mechanical stretch occurs.

MARCH5 restores endothelial cell function against ischaemic/hypoxia injury via Akt/eNOS pathway

MARCH5 is a critical regulator of mitochondrial dynamics, apoptosis and mitophagy. However, its role in cardiovascular system remains poorly understood. This study aimed to investigate the role of MARCH5 in endothelial cell (ECs) injury and the involvement of the Akt/eNOS signalling pathway in this process. Rat models of myocardial infarction (MI) and human cardiac microvascular endothelial cells (HCMECs) exposed to hypoxia (1% O₂) were used in this study. MARCH5 expression was significantly reduced in ECs of MI hearts and ECs exposed to hypoxia. Hypoxia inhibited the proliferation, migration and tube formation of ECs, and these effects were aggravated by knockdown of MARCH5 but antagonized by overexpressed MARCH5. Overexpression of MARCH5 increased nitric oxide (NO) content, p‐eNOS and p‐Akt, while MARCH5 knockdown exerted the opposite effects. The protective effects mediated by MARCH5 overexpression on ECs could be inhibited by eNOS inhibitor L‐NAME and Akt inhibitor LY294002. In conclusion, these results indicated that MARCH5 acts as a protective factor in ischaemia/hypoxia‐induced ECs injury partially through Akt/eNOS pathway.

Trajectories of Left Ventricular Ejection Fraction After Acute Decompensation for Systolic Heart Failure: Concomitant Echocardiographic and Systemic Changes, Predictors, and Impact on Clinical Outcomes

Background

Prospective longitudinal follow‐up of left ventricular ejection fraction (LVEF) trajectories after acute cardiac decompensation of heart failure is lacking. We investigated changes in LVEF and covariates at 6‐months' follow‐up in patients with a predischarge LVEF ≤40%, and determined predictors and prognostic implications of LVEF changes through 18‐months' follow‐up.

Methods and Results

Interdisciplinary Network Heart Failure program participants (n=633) were categorized into subgroups based on LVEF at 6‐months' follow‐up: normalized LVEF (>50%; heart failure with normalized ejection fraction, n=147); midrange LVEF (41%–50%; heart failure with midrange ejection fraction, n=195), or persistently reduced LVEF (≤40%; heart failure with persistently reduced LVEF , n=291). All received guideline‐directed medical therapies. At 6‐months' follow‐up, compared with patients with heart failure with persistently reduced LVEF, heart failure with normalized LVEF or heart failure with midrange LVEF subgroups showed greater reductions in LV end‐diastolic/end‐systolic diameters (both P<0.001), and left atrial systolic diameter (P=0.002), more increased septal/posterior end‐diastolic wall‐thickness (both P<0.001), and significantly greater improvement in diastolic function, biomarkers, symptoms, and health status. Heart failure duration <1 year, female sex, higher predischarge blood pressure, and baseline LVEF were independent predictors of LVEF improvement. Mortality and event‐free survival rates were lower in patients with heart failure with normalized LVEF (P=0.002). Overall, LVEF increased further at 18‐months' follow‐up (P<0.001), while LV end‐diastolic diameter decreased (P=0.048). However, LVEF worsened (P=0.002) and LV end‐diastolic diameter increased (P=0.047) in patients with heart failure with normalized LVEF hospitalized between 6‐months' follow‐up and 18‐months' follow‐up.

Conclusions

Six‐month survivors of acute cardiac decompensation for systolic heart failure showed variable LVEF trajectories, with >50% showing improvements by ≥1 LVEF category. LVEF changes correlated with various parameters, suggesting multilevel reverse remodeling, were predictable from several baseline characteristics, and were associated with clinical outcomes at 18‐months' follow‐up. Repeat hospitalizations were associated with attenuation of reverse remodeling.

Registration

URL: https://www.controlled‐trials.com; Unique identifier: ISRCTN23325295.

Hypoxia-inducible factor 2-alpha-dependent induction of IL-6 protects the heart from ischemia/reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) results in increased myocardial infarct size and leads to poor clinical outcomes. Hypoxia-inducible factor 2-alpha (HIF2α) exerts myocardial protective effects during MIRI through as yet unclear mechanisms. Here, we show that knockdown of HIF2α with cardiotropic recombinant adeno-associated virus serotype 9 (rAAV9) in mouse hearts significantly increased the infarct sizes during myocardial ischemia/reperfusion (MI/R). In addition, HIF2α transcriptionally regulated the expression of interleukin 6 (IL-6) in cardiomyocytes to elicit cardioprotection. Likewise, IL-6 deficiency aggravated MIRI, while treatment with recombinant IL-6 had cardioprotective effects and rescued the mice with HIF2α knockdown. Furthermore, IL-6 treatment significantly activated the PI3K/Akt and STAT3 signaling pathways in the myocardium during MI/R, and the specific inhibitors wortmannin (specific phosphoinositide 3-kinase inhibitor) and Stattic (specific STAT3 inhibitor) substantially abolished HIF2α/IL-6-induced cardioprotection. These studies suggest that HIF2α transcription regulates the expression of IL-6 in cardiomyocytes and plays a protective role during MI/R.

Are activated B cells involved in the process of myocardial fibrosis after acute myocardial infarction? An in vivo experiment

BACKGROUND

Inflammatory cells infiltrate into the ischemic and hypoxic myocardial tissue after myocardial infarction. B cells gather at the site of myocardial injury and secrete cytokines to regulate immune inflammation and fiber repair processes.

METHODS

The animal experiment used ligation of the left anterior descending (LAD) artery of C57BL/6 mice to establish a mouse acute myocardial infarction (AMI) model to observe changes in activated B cells and cytokines at different time points. Twelve-week-old C57BL/6 male mice were randomly divided into the Sham group (24 mice) (thread under the LAD artery without ligation) and the AMI group (64 mice). In addition, C57BL/6 B-cell knockout (BKO) mice and C57BL/6 wild-type (WT) mice were used to establish AMI models to observe the expression levels of cardiomyocyte cytokines, such as TNF-α IL-1β, IL-6, TGF-β1, COL1-A1, COL3-AIII, TIMP, and MMP9. Moreover, pathological and collagen changes in the myocardium were analysed. One-way ANOVA and LSD method was used for comparisons of multiple and pairwise groups respectively. P < 0.05 indicated significant differences.

RESULTS

An AMI model of C57BL/6 mice was established successfully. The ratio of activated B cells and the expression of TNF-α, IL-1β, IL-6, TGF-β1, and B cell activating factor (BAFF) in the 5-day subgroup were the highest in the myocardium, spleen and peripheral blood with the most obvious myocardial inflammatory cell infiltration. The cytokines mRNA expression levels in the 5-day subgroup of the BKO group were decreased compared with those in the WT group (P < 0.05). Among the 2-week subgroups of the Sham, WT and BKO groups, the the LVEDd and LVESd of the BKO group were lower than those of the WT group (P < 0.05), and the left ventricular ejection fraction was higher than that of the WT group (P < 0.05).

CONCLUSION

Activated B cells participate in the sustained state of myocardial inflammation and immune system activation after AMI, and may affect the metabolism of myocardial collagen after AMI by secreting cytokines. Moreover, B cells promote the expression of myocardial collagen Type I and Type III and damage the left ventricular ejection function.

Computational model predicts paracrine and intracellular drivers of fibroblast phenotype after myocardial infarction

The fibroblast is a key mediator of wound healing in the heart and other organs, yet how it integrates multiple time-dependent paracrine signals to control extracellular matrix synthesis has been difficult to study in vivo. Here, we extended a computational model to simulate the dynamics of fibroblast signaling and fibrosis after myocardial infarction (MI) in response to time-dependent data for nine paracrine stimuli. This computational model was validated against dynamic collagen expression and collagen area fraction data from post-infarction rat hearts. The model predicted that while many features of the fibroblast phenotype at inflammatory or maturation phases of healing could be recapitulated by single static paracrine stimuli (interleukin-1 and angiotensin-II, respectively), mimicking the reparative phase required paired stimuli (e.g. TGFβ and endothelin-1). Virtual overexpression screens simulated with either static cytokine pairs or post-MI paracrine dynamic predicted phase-specific regulators of collagen expression. Several regulators increased (Smad3) or decreased (Smad7, protein kinase G) collagen expression specifically in the reparative phase. NADPH oxidase (NOX) overexpression sustained collagen expression from reparative to maturation phases, driven by TGFβ and endothelin positive feedback loops. Interleukin-1 overexpression had mixed effects, both enhancing collagen via the TGFβ positive feedback loop and suppressing collagen via NFκB and BAMBI (BMP and activin membrane-bound inhibitor) incoherent feed-forward loops. These model-based predictions reveal network mechanisms by which the dynamics of paracrine stimuli and interacting signaling pathways drive the progression of fibroblast phenotypes and fibrosis after myocardial infarction.

Pentraxin 3 in primary percutaneous coronary intervention for ST elevation myocardial infarction is associated with early irreversible myocardial damage : Kinetic profile, relationship to interleukin 6 and infarct size

Background

The inflammatory marker long pentraxin 3 (PTX3) has been shown to be a strong predictor of 30-day and one-year mortality after acute myocardial infarction. The aim of this study was to evaluate the kinetic profile of PTX3 and its relationship with interleukin 6 (IL-6), high-sensitive C-reactive protein (hs-CRP) and infarct size.

Methods

PTX3, IL-6 and hs-CRP were measured at predefined time points, at baseline (before percutaneous coronary intervention (PCI)), at 12 and 72 hours after PCI in 161 patients with first-time ST elevation myocardial infarction (STEMI).

Results

PTX3 and IL-6 levels increased in the early phase, followed by a gradual decrease between 12 and 72 hours. There were statistically significant correlations between PTX3 and IL-6 in general, for all time points and for changes over time (0–72 hours). In a linear mixed model, PTX3 predicted IL-6 (p < 0.001). PTX3 is also correlated with hs-CRP in general, and at each time point post PCI, except at baseline. PTX3, IL-6 and hs-CRP were all significantly correlated with infarct size in general, and at the peak time point for maximum troponin I. In addition, there was a modest correlation between IL-6 levels at baseline and infarct size at 72 hours after PCI (ρ = 0.23, p = 0.006).

Conclusions

PTX3 had a similar kinetic profile to IL-6, with an early increase and decline, and was statistically significantly correlated with markers of infarct size in STEMI patients post primary PCI. Baseline levels of IL-6 only predicted infarct size at 72 hours post PCI.

CXCL9 and CXCL10 display an age-dependent profile in Chagas patients: a cohort study of aging in Bambui, Brazil

Background

Chagas disease is endemic in Latin America and still represents an important public health problem in the region. Chronic cardiomyopathy is the most significant chronic form due to its association with morbidity and mortality. The last decade has seen increasing evidence that inflammatory cytokines and chemokines are responsible for the generation of inflammatory infiltrate and tissue damage, with chronic chagasic cardiomyopathy patients presenting a pro-inflammatory immune response. Although studies have evaluated the role of chemokines in experimental T. cruzi infection, few have addressed their systemic profile, especially for human infection and in aging populations. The present work aimed to use the data from a large population based study of older adults, conducted in an endemic area for Chagas disease, to examine the association between serum levels of cytokines and chemokines, T. cruzi infection and electrocardiogram (ECG) abnormality.

Methods

The present work evaluated serum levels of CCL2, CXCL9, CXCL10, CCL5, CXCL8, IL-1β, IL-6, TNF, IL-12 and IL-10 by Flow Cytometric Bead Array assay (CBA) and the results expressed in pg/ml. The baseline survey started in January 1st 1997, with 1284 participants of an aged population-based cohort. Participants signed an informed consent at baseline and at each subsequent visit and authorized death certificate and medical records verification.

Results

Our results demonstrated that Chagas disease patients had higher serum levels of CXCL9, CXCL10 and IL-1β and lower serum levels of CCL5 than non-infected subjects. Moreover, our data demonstrated that CXCL9 and CXCL10 increased in an age-dependent profile in Chagas disease patients.

Conclusion

Together, this study provided evidences that serum biomarkers increase along the age continuum and may have potential implications for establishing clinical management protocols and therapeutic intervention in Chagas disease patients.

Cardioprotective Effect of (Z)-2-Acetoxy-3-(3,4-Dihydroxyphenyl) Acrylic Acid: Inhibition of Apoptosis in Cardiomyocytes

Background

Although many studies have been performed to elucidate the molecular mechanisms of heart failure, an effective pharmacological therapy to protect cardiac tissues from severe loss of contractile function associated with heart failure after acute myocardial infarction (MI) has yet to be developed.

Methods

We examined the cardioprotective effects of (Z)-2-acetoxy-3-(3,4-dihydroxyphenyl) acrylic acid, a new compound with potent antioxidant and antiapoptotic activities in a rat model of heart failure. (Z)-2-Acetoxy-3-(3,4-dihydroxyphenyl) acrylic acid was systemically delivered to rats 6 weeks after MI at different doses (15, 30, and 60 mg/kg). Cardiac function was assessed by hemodynamic measurements. The expression of proinflammatory cytokines, apoptosis-related molecules, and markers of adverse ventricular remodeling was measured using RT-PCR and Western blot.

Results

Treatment with (Z)-2-acetoxy-3-(3,4-dihydroxyphenyl) acrylic acid significantly improved cardiac function, in particular by increasing dP/dt. Simultaneously, the expression of the proinflammatory cytokines TNF-α and IL-1β was markedly reduced in the treatment group compared with the MI group. In addition, (Z)-2-acetoxy-3-(3,4-dihydroxyphenyl) acrylic acid-treated tissues displayed decreased expression of Bax, caspase-3, and caspase-9 and increased expression of Bcl-2, which was in part due to the promotion of Akt phosphorylation.

Conclusion

These data demonstrated that (Z)-2-acetoxy-3-(3,4-dihydroxyphenyl) acrylic acid possesses potent cardioprotective effects against cardiac injury in a rat model of heart failure, which is mediated, at least in part, by suppression of the inflammatory and cell apoptosis responses.

Substrate for the Myocardial Inflammation-Heart Failure Hypothesis Identified Using Novel USPIO Methodology

OBJECTIVES

The purpose of this study was to identify where ultrasmall superparamagnetic particles of iron oxide (USPIO) locate to in myocardium, develop a methodology that differentiates active macrophage uptake of USPIO from passive tissue distribution; and investigate myocardial inflammation in cardiovascular diseases.

BACKGROUND

Myocardial inflammation is hypothesized to be a key pathophysiological mechanism of heart failure (HF), but human evidence is limited, partly because evaluation is challenging. USPIO-magnetic resonance imaging (MRI) potentially allows specific identification of myocardial inflammation but it remains unclear what the USPIO-MRI signal represents.

METHODS

Histological validation was performed using a murine acute myocardial infarction (MI) model. A multiparametric, multi-time-point MRI methodology was developed, which was applied in patients with acute MI (n = 12), chronic ischemic cardiomyopathy (n = 7), myocarditis (n = 6), dilated cardiomyopathy (n = 5), and chronic sarcoidosis (n = 5).

RESULTS

USPIO were identified in myocardial macrophages and myocardial interstitium. R1 time-course reflected passive interstitial distribution whereas multi-time-point R2* was also sensitive to active macrophage uptake. R2*/R1 ratio provided a quantitative measurement of myocardial macrophage infiltration. R2* behavior and R2*/R1 ratio were higher in infarcted (p = 0.001) and remote (p = 0.033) myocardium in acute MI and in chronic ischemic cardiomyopathy (infarct: p = 0.008; remote p = 0.010), and were borderline higher in DCM (p = 0.096), in comparison to healthy controls, but were no different in myocarditis or sarcoidosis. An R2*/R1 threshold of 25 had a sensitivity and specificity of 90% and 83%, respectively, for detecting active USPIO uptake.

CONCLUSIONS

USPIO are phagocytized by cardiac macrophages but are also passively present in myocardial interstitium. A multiparametric multi-time-point MRI methodology specifically identifies active myocardial macrophage infiltration. Persistent active macrophage infiltration is present in infarcted and remote myocardium in chronic ischemic cardiomyopathy, providing a substrate for HF.

The Relationship between Tumor Necrosis Factor Alpha and Left Ventricular Diastolic Function

Introduction:

Left ventricular (LV) diastolic dysfunction is a common condition. Tumor necrosis factor (TNF) alpha is an inflammatory cytokine that plays a role in the development of cardiac structural changes leading to LV diastolic dysfunction. The aim of this study was to examine the relationship between serum levels of TNF alpha levels and LV diastolic function.

Methods:

A case–control study that included 40 patients with echocardiographic evidence of LV diastolic dysfunction and 40 healthy controls. Standard transthoracic echocardiography was performed to assess LV and left atrial volumes, systolic and diastolic function according to the current recommendations. Serum TNF alpha levels were assessed using a specific enzyme-linked immunosorbent assay kit.

Results:

Mean serum TNF alpha level was significantly higher in the study group 3.48 ± 1.06 versus 1.22 ± 0.36 pg/ml in the control group, P < 0.001. It was also higher in patients with Grade 2 diastolic dysfunction (n = 16) 3.91 ± 1.21 versus 3.18 ± 0.86 pg/ml in those with Grade 1 diastolic dysfunction (n = 24), P = 0.03. TNF alpha showed a strong correlation with indexed left atrial volume (LAVI) in the study group but not in controls. Mean serum TNF showed a trend toward increase with worsening heart failure symptoms in the form of increased the New York Heart Association functional class.

Conclusion:

Serum TNF alpha level is elevated in patients with LV diastolic dysfunction and is correlated to LAVI in such patients. Patients with Grade 2 diastolic dysfunction have higher serum levels of TNF alpha compared to those with Grade 1 diastolic dysfunction. TNF alpha levels increase with worsening heart failure symptoms.

Inflammation in myocardial injury- Stem cells as potential immunomodulators for myocardial regeneration and restoration

The ineffective immunosuppressant's and targeted strategies to neutralize inflammatory mediators have worsened the scenario of heart failure and have opened many questions for debate. Stem cell therapy has proven to be a promising approach for treating heart following myocardial infarction (MI). Adult stem cells, induced pluripotent stem cells and embryonic stem cells are possible cell types and have successfully shown to regenerate damaged myocardial tissue in pre-clinical and clinical studies. Current implications of using mesenchymal stem cells (MSCs) owing to their immunomodulatory functions and paracrine effects could serve as an effective alternative treatment option for rejuvenating the heart post MI. The major setback associated with the use of MSCs is reduced cell retention, engraftment and decreased effectiveness. With a few reports on understanding the role of inflammation and its dual effects on the structure and function of heart, this review focuses on these missing insights and further exemplifies the role of MSCs as an alternative therapy in treating the pathological consequences in myocardial infarction (MI).

Elevated Inflammatory Plasma Biomarkers in Patients With Fabry Disease: A Critical Link to Heart Failure With Preserved Ejection Fraction

Background

Because systemic inflammation and endothelial dysfunction lead to heart failure with preserved ejection fraction, we characterized plasma levels of inflammatory and cardiac remodeling biomarkers in patients with Fabry disease (FD).

Methods and Results

Plasma biomarkers were studied in multicenter cohorts of patients with FD (n=68) and healthy controls (n=40). Plasma levels of the following markers of inflammation and cardiac remodeling were determined: tumor necrosis factor (TNF), TNF receptor 1 (TNFR1) and 2 (TNFR2), interleukin‐6, matrix metalloprotease‐2 (MMP‐2), MMP‐8, MMP‐9, galectin‐1, galectin‐3, B‐type natriuretic peptide (BNP), midregional pro–atrial natriuretic peptide (MR‐proANP), and globotriaosylsphingosine. Clinical profile, cardiac magnetic resonance imaging, and echocardiogram were reviewed and correlated with biomarkers. Patients with FD had elevated plasma levels of BNP, MR‐proANP, MMP‐2, MMP‐9, TNF, TNFR1, TNFR2, interleukin‐6, galectin‐1, globotriaosylsphingosine, and analogues. Plasma TNFR2, TNF, interleukin‐6, MMP‐2, and globotriaosylsphingosine were elevated in FD patients with left ventricular hypertrophy, whereas diastolic dysfunction correlated with higher BNP, MR‐proANP, and MMP‐2 levels. Patients with late gadolinium enhancement on cardiac magnetic resonance imaging had greater levels of BNP, MR‐proANP, TNFR1, TNFR2, and MMP‐2. Plasma BNP, MR‐proANP, MMP‐2, MMP‐8, TNF, TNFR1, TNFR2, galectin‐1, and galectin‐3 were elevated in patients with renal dysfunction. Patients undergoing enzyme replacement therapy who have more severe disease had higher MMP‐2, TNF, TNFR1, TNFR2, and globotriaosylsphingosine analogue levels.

Conclusions

Inflammatory and cardiac remodeling biomarkers are elevated in FD patients and correlate with disease progression. These features are consistent with a phenotype dominated by heart failure with preserved ejection fraction and suggest a key pathogenic role of systemic inflammation in FD.

Effects of genetic transfection on calcium cycling pathways mediated by double-stranded adeno-associated virus in postinfarction remodeling

OBJECTIVE

Restoring calcium sensor protein (S100A1) activity in failing hearts poses a promising therapeutic strategy. We hypothesize that cardiac overexpression of the S100A1 gene mediated by a double-stranded adeno-associated virus (scAAV) results in better functional and molecular improvements compared with the single-stranded virus (ssAAV).

METHODS

Heart failure was induced by coronary artery ligation. Then, intramyocardial injections of saline, AAV9 empty capsid, scAAV9.S100A1, and ssAAV9.S100A1 were performed. Ten weeks postinfarction, all rats received cardiac evaluation; serum and tissue were collected for genetic analysis, cytokine profiling, and assessments of mitochondrial function and structure.

RESULTS

Overexpression of AAV9.S100A1 improved systolic and diastolic function. Compared with control, ejection fraction was greater in treated groups (54.8% vs 32.3%, P < .05). Similarly, end-diastolic volume index was significantly less in the treated group than in control (1.14 vs 1.59 mL/cm²), whereas fractional shortening was greater in treated groups than control (26% vs 38%, P < .05). Interestingly, cardiac mechanics were significantly better when treated with double-stranded virus compared with single-stranded. Quantitative polymerase chain reaction demonstrated robust transfection of myocardium with the S100A1 gene, with more infection in the self-complimentary group compared with the single-stranded group (5.68 ± 0.44 vs 4.09 ± 0.25 log₁₀ genome copies per 100 ng of DNA; P < .0001). Concentrations of the inflammatory cytokines were elevated in the ssAAV9/S100A1 group compared with the scAAV9/S100A1. Assessment of mitochondrial respiration and morphology demonstrated that injection of self-complementary vector saved both mitochondrial structure and function.

CONCLUSIONS

Gene therapy of S100A1 can prevent pathologic postmyocardial infarction remodeling and decrease inflammatory response in ischemic heart failure.

Different signalling in infarcted and non-infarcted areas of rat failing hearts: A role of necroptosis and inflammation

Necroptosis has been recognized in heart failure (HF). In this study, we investigated detailed necroptotic signalling in infarcted and non‐infarcted areas separately and its mechanistic link with main features of HF. Post‐infarction HF in rats was induced by left coronary occlusion (60 minutes) followed by 42‐day reperfusion. Heart function was assessed echocardiographically. Molecular signalling and proposed mechanisms (oxidative stress, collagen deposition and inflammation) were investigated in whole hearts and in subcellular fractions when appropriate. In post‐infarction failing hearts, TNF and pSer229‐RIP3 levels were comparably increased in both infarcted and non‐infarcted areas. Its cytotoxic downstream molecule p‐MLKL, indicating necroptosis execution, was detected in infarcted area. In non‐infarcted area, despite increased pSer229‐RIP3, p‐MLKL was present in neither whole cells nor the cell membrane known to be associated with necroptosis execution. Likewise, increased membrane lipoperoxidation and NOX2 levels unlikely promoted pro‐necroptotic environment in non‐infarcted area. Collagen deposition and the inflammatory csp‐1‐IL‐1β axis were active in both areas of failing hearts, while being more pronounced in infarcted tissue. Although apoptotic proteins were differently expressed in infarcted and non‐infarcted tissue, apoptosis was found to play an insignificant role. p‐MLKL‐driven necroptosis and inflammation while inflammation only (without necroptotic cell death) seem to underlie fibrotic healing and progressive injury in infarcted and non‐infarcted areas of failing hearts, respectively. Upregulation of pSer229‐RIP3 in both HF areas suggests that this kinase, associated with both necroptosis and inflammation, is likely to play a dual role in HF progression.

Inflammation in myocardial injury: mesenchymal stem cells as potential immunomodulators

Ischemic heart disease is a growing worldwide epidemic. Improvements in medical and surgical therapies have reduced early mortality after acute myocardial infarction and increased the number of patients living with chronic heart failure. The irreversible loss of functional cardiomyocytes puts these patients at significant risk of ongoing morbidity and mortality after their index event. Recent evidence suggests that inflammation is a key mediator of postinfarction adverse remodeling in the heart. In this review, we discuss the cardioprotective and deleterious effects of inflammation and its mediators during acute myocardial infarction. We also explore the role of mesenchymal stem cell therapy to limit secondary injury and promote myocardial healing after myocardial infarction.

Clofibrate Treatment Decreases Inflammation and Reverses Myocardial Infarction-Induced Remodelation in a Rodent Experimental Model

Myocardial infarction (MI) initiates an inflammatory response that promotes both beneficial and deleterious effects. The early response helps the myocardium to remove damaged tissue; however, a prolonged later response brings cardiac remodeling characterized by functional, metabolic, and structural pathological changes. Current pharmacological treatments have failed to reverse ischemic-induced cardiac damage. Therefore, our aim was to study if clofibrate treatment was capable of decreasing inflammation and apoptosis, and reverse ventricular remodeling and MI-induced functional damage. Male Wistar rats were assigned to (1) Sham coronary artery ligation (Sham) or (2) Coronary artery ligation (MI). Seven days post-MI, animals were further divided to receive vehicle (V) or clofibrate (100 mg/kg, C) for 7 days. The expression of IL-6, TNF-α, and inflammatory related molecules ICAM-1, VCAM-1, MMP-2 and -9, nuclear NF-kB, and iNOS, were elevated in MI-V. These inflammatory biomarkers decreased in MI-C. Also, apoptotic proteins (Bax and pBad) were elevated in MI-V, while clofibrate augmented anti-apoptotic proteins (Bcl-2 and 14-3-3ε). Clofibrate also protected MI-induced changes in ultra-structure. The ex vivo evaluation of myocardial functioning showed that left ventricular pressure and mechanical work decreased in infarcted rats; clofibrate treatment raised those parameters to control values. Echocardiogram showed that clofibrate partially reduced LV dilation. In conclusion, clofibrate decreases cardiac remodeling, decreases inflammatory molecules, and partly preserves myocardial diameters.

Anti-inflammatory activities of hepatocyte growth factor in post-ischemic heart failure

Hepatocyte growth factor (HGF) alleviates acute and chronic inflammation in experimental inflammatory bowel disease, glomerulonephritis, and airway inflammation. However, the anti-inflammatory effects of HGF on myocardial infarction are not defined. The current study assessed the anti-inflammatory effects of HGF in post-ischemic heart failure. The left anterior descending coronary artery was ligated in rats, and adenovirus containing human HGF (Ad-HGF) or control virus (Ad-GFP) was administered intramyocardially. The quantity of proinflammatory cytokines secreted by cardiomyocytes, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β, was evaluated. Cardiac function and LV remodeling were assessed using echocardiography and collagen deposition, respectively. Left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) four weeks after injection were significantly increased in Ad-HGF-treated animals compared to the Ad-GFP group. HGF gene therapy improved ventricular geometry with a significantly decreased left ventricular end-diastolic diameter (LVEDD) and markedly reduced myocardial collagen deposition. Treatment with Ad-HGF significantly decreased the mRNA levels of TNF-α, IL-6, and IL-1β in the non-infarcted region four weeks after injection. Changes of the TNF-α, IL-6, and IL-1β levels in the non-infarcted region positively correlated with the LVEDD 4 weeks after infarction. Treatment of acute myocardial infarction (AMI) with Ad-HGF in the early stage of MI reduced the pro-inflammatory cytokine levels and preserved cardiac function. These findings indicated that Ad-HGF gene therapy alleviated ventricular remodeling after infarction by reducing inflammation.

Chronic median nerve modulation reduces ventricular arrhythmia and improves ventricular function in a postmyocardial infarction rabbit model

AIM

Median nerve stimulation (MNS) is a novel neuromodulation approach for treatment of ventricular arrhythmia, but little is known about its chronic effects. The aim of this study was to investigate the effects of chronic MNS on ventricular arrhythmia and ventricular dysfunction postmyocardial infarction (MI).

METHOD

Two weeks after MI, 12 rabbits were randomly divided into control and MNS groups, and chronic MNS was performed in MNS group for 2 weeks. Ventricular function and arrhythmias; sympathetic innervation and activity; and interleukin-1 β (IL-1 β) and norepinephrine (NE) levels were analyzed.

RESULTS

Both the total number of premature ventricular complex and episodes of ventricular tachycardia were lower in MNS group than in control group (20 560 ± 10 314 beats vs 70 079 ± 37 184 beats, P = .021, and 115 ± 63 episodes vs 307 ± 164 episodes, P = .034, respectively). Compared with control group, MNS decreased the cardiac sympathetic nerve density and level of circulating NE in MNS group (1798.42 ± 644.07 μm² /mm² vs 1003.79 ± 453.00 μm² /mm²_, P = .041, and 20.86 ± 4.54 pg/mL vs 11.07 ± 1.43 pg/mL, P = .002, respectively). MNS also improved the left ventricular ejection fraction (59.07 ± 1.91% vs 49.77 ± 3.47%, P = .003) and inhibited the level of IL-1 β in serum (69.19 ± 4.71 pg/mL vs 85.93 ± 12.80 pg/mL, P = .013).

CONCLUSION

Chronic MNS appears to protect against ventricular arrhythmia and improves ventricular function post-MI, which may be mediated by suppressing cardiac sympathetic activity and anti-inflammatory effects.

The pathophysiology of myocardial infarction-induced heart failure

Heart failure (HF) is a multifactorial disorder and is usually the end stage of many cardiovascular diseases (CVD). HF presents one of the highest morbidity and mortality indices worldwide and high costs to public health organizations. Myocardial infarction (MI) is the most prevalent CVD in the Western world and leads to HF when its management is inadequate. It has a destructive potential for heart cells and abruptly reduces the cardiac output, a clinical condition known as heart dysfunction that might progress to HF. Many acute and chronic adaptations occur due to MI that progress to HF, e.g., neurohumoral hyperactivity, inflammatory response and cardiac remodeling. Herein, we reviewed in simplistic manner the processes involved in setting of MI until the establishment of HF.

Neutrophil to lymphocyte ratio as a predictor of myocardial damage and cardiac dysfunction in acute coronary syndrome patients

Background

Neutrophil to lymphocyte ratio (NLR) in peripheral blood is established to correlate with the morbidity and mortality of heart disease patients. We aimed to define the severity of inflammation (NLR) by observing the association of NLR with cardiac functions or myocardial damage parameters in patients with acute myocardial infarction.

Methods

Data from 715 patients who underwent percutaneous coronary intervention (PCI) within 72 hours of incidence in 2016 were analysed retrospectively.

Results

The NLR ranges from 0.50 to 46 (medium ± SD, 2.76 ± 2.96) in 715 patients. NLR positively correlated with myocardial damage (NLR vs. CK-mB: p < 0.0001) but negatively correlated with myocardial function (NLR vs. EF: p < 0.0001; NLR vs. FS: p < 0.0001). Myocardial damage markers (CK, CK-mB, ASL, LDH) were significantly increased, and cardiac contractile parameters (EF and FS) were reduced at NLR > 2.76 compared to those of NLR < 2.76. ELISA analysis has shown that IL-10 was significantly increased when NLR ≥ 4.6 and TGF-β was increased at NLR > 4. The correlation was diminished between NLR and CK-mB at NLR > 2.76 or at NLR > 4, but that of NLR and EF or FS was maintained in NLR > 2.76 and at NLR > 4. EF and FS were comparable between NLR > 2.76 and NLR > 4. But myocardial damage parameters increased significantly at NLR > 4 compared to those of NLR > 2.76.

Conclusion

NLR is a strong predictor of myocardial damage in acute myocardial patients. High NLR are associated with myocardial dysfunction in all the patients. Severe inflammation (NLR) can predict the consequence of the heart in patients with coronary syndrome.

Inflammatory Response During Myocardial Infarction

The occlusion of a coronary artery by a thrombus generated on a ruptured atherosclerotic plaque has been pursued in the last decades as a determining event for the clinical outcome after myocardial infarction (MI). Yet, MI causes a cell death wave front, which triggers an inflammatory response to clear cellular debris, and which in excess can double the myocardial lesion and influence the clinical prognosis in the short and long term. Accordingly, proper, timely regulated inflammatory response has now been considered a second pivotal player in cardiac recovery after MI justifying the search for pharmacological strategies to modulate inflammatory effectors. This chapter reviews the key events and the main effectors of inflammation after myocardial ischemic insult, as well as the contribution of this phenomenon to the progression of atherosclerosis.

Inflammation following acute myocardial infarction: Multiple players, dynamic roles, and novel therapeutic opportunities

Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients.

Effects of exercise training on brain-derived neurotrophic factor in skeletal muscle and heart of rats post myocardial infarction

NEW FINDINGS

What is the central question of this study? Exercise training increases brain-derived neurotrophic factor (BDNF) in the hippocampus, which depends on a myokine, fibronectin type III domain-containing protein 5 (FNDC5). Whether exercise training after myocardial infarction induces parallel increases in FNDC5 and BDNF expression in skeletal muscle and the heart has not yet been studied. What is the main finding and its importance? Exercise training after myocardial infarction increases BDNF protein in skeletal muscle and the non-infarct area of the LV without changes in FNDC5 protein, suggesting that BDNF is not regulated by FNDC5 in skeletal muscle and heart. An increase in cardiac BDNF may contribute to the improvement of cardiac function by exercise training. Exercise training after myocardial infarction (MI) attenuates progressive left ventricular (LV) remodelling and dysfunction, but the peripheral stimuli induced by exercise that trigger these beneficial effects are still unclear. We investigated as possible mediators fibronectin type III domain-containing protein 5 (FNDC5) and brain-derived neurotrophic factor (BDNF) in the skeletal muscle and heart. Male Wistar rats underwent either sham surgery or ligation of the left descending coronary artery, and surviving MI rats were allocated to either a sedentary (Sed-MI) or an exercise group (ExT-MI). Exercise training was done for 4 weeks on a motor-driven treadmill. At the end, LV function was evaluated, and FNDC5 and BDNF mRNA and protein were assessed in soleus muscle, quadriceps and non-, peri- and infarct areas of the LV. At 5 weeks post MI, FNDC5 mRNA was decreased in soleus muscle and all areas of the LV, but FNDC5 protein was increased in the soleus muscle and the infarct area. Mature BDNF (mBDNF) protein was decreased in the infarct area without a change in mRNA. Exercise training attenuated the decrease in ejection fraction and the increase in LV end-diastolic pressure post MI. Exercise training had no effect on FNDC5 mRNA and protein, but increased mBDNF protein in soleus muscle, quadriceps and the non-infarct area of the LV. The mBDNF protein in the non-infarct area correlated positively with ejection fraction and inversely with LV end-diastolic pressure. In conclusion, mBDNF is induced by exercise training in skeletal muscle and the non-infarct area of the LV, which may contribute to improvement of muscle dysfunction and cardiac function post MI.

Assessment of safety and efficacy of mesenchymal stromal cell therapy in preclinical models of acute myocardial infarction: a systematic review protocol

BACKGROUND

Despite advances in treatment, acute myocardial infarction (MI) is still associated with significant morbidity and mortality, especially in patients with extensive damage and scar formation. Based on some promising preclinical studies, there is interest in the use of mesenchymal stromal cells (MSCs) to promote cardiac repair after acute MI. However, there is a need for a systematic review of this evidence to summarize the efficacy and safety of MSCs in preclinical models of MI. This will better inform the translation of MSC therapy for acute MI and guide the design of a future clinical trial.

METHODS/DESIGN

A systematic literature search of MEDLINE, Embase, and BIOSIS Previews will be conducted. We will identify comparative preclinical studies (randomized and non-randomized) of myocardial infarction that include animals given MSC therapy versus a vehicle/placebo. The primary outcome will be left ventricular ejection fraction. Secondary and tertiary outcomes will include death, infarct size, measures of cardiac function, biochemical outcomes, and MSC retention and differentiation. Risk of bias will be assessed using the Cochrane Risk of Bias Tool. Subgroup analyses will be performed to measure how various sources of preclinical study heterogeneity affect the direction and magnitude of the primary outcome. We will meta-analyze data using inverse variance random effects modeling.

DISCUSSION

This systematic review of preclinical evidence will provide a summary of the efficacy and safety of MSCs in animal models of MI. The results will help determine whether sufficient evidence exists to conduct a clinical trial in humans and inform its design.

Cholinergic Stimulation Improves Oxidative Stress and Inflammation in Experimental Myocardial Infarction

We previously reported that cholinergic stimulation with pyridostigmine (PY) induces anti-inflammatory cell recruitment soon after myocardial infarction (MI). In this study, we evaluated the anti-inflammatory effects of PY during the proliferative phase of cardiac repair by analyzing the infiltration of macrophages, Treg lymphocytes, oxidative stress and inflammatory cytokines. Wistar rats underwent control sham surgery or ligation of the left coronary artery and were randomly allocated to remain untreated (untreated infarcted group, I) or to receive PY (30 mg·kg(−1)·day(−1)) in the supplied water (infarcted treated group, I + PY). Blood pressure and heart rate variability were registered at day 5 post-MI. The animals were euthanized 7 days after thoracotomy, when the hearts were removed and processed for immunohistochemistry (CD68, CD206, FOXP3), cytokines (IL-1β, IL-6, IL-10, TNF-α) and oxidative stress (superoxide dismutase, catalase, glutathione peroxidase, lipidic and protein peroxidation). PY treatment increased parasympathetic modulation, M2 macrophages and the anti-oxidant enzyme activity but reduced protein oxidation (carbonyls) and the concentration of IL-1β, IL-6, TNF-α and IL-10. Cholinergic stimulation induces parasympathetic neuro-immune modulation and anti-inflammatory cell enrollment as well as prevents oxidative stress and cytokine production after MI.

VCP746, a novel A1 adenosine receptor biased agonist, reduces hypertrophy in a rat neonatal cardiac myocyte model

VCP746 is a novel A1 adenosine receptor (A1 AR) biased agonist previously shown to be cytoprotective with no effect on heart rate. The aim of this study was to investigate the potential anti-hypertrophic effect of VCP746 in neonatal rat cardiac myocytes (NCM). NCM hypertrophy was stimulated with interleukin (IL)-1β (10 ng/mL), tumour necrosis factor (TNF)-α (10 ng/mL) or Ang II (100 nmol/L) and was assessed by (3) H-leucine incorporation assay. VCP746 significantly inhibited IL-1β-, TNF-α- and Ang II-stimulated NCM hypertrophy as determined by (3) H-leucine incorporation. The anti-hypertrophic effect of VCP746 was also more potent than that of the prototypical A1 AR agonist, N(6) -cyclopentyladenosine (CPA). Further investigation with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay showed that neither CPA nor VCP746 had any effect on cell viability, confirming that the reduction in (3) H-leucine incorporation mediated by CPA and VCP746 was not due to a reduction in cell viability. IL-1β, TNF-α and Ang II were also shown to increase the mRNA expression of hypertrophy biomarkers, ANP, β-MHC and α-SKA in NCM. Treatment with VCP746 at concentrations as low as 1 nmol/L suppressed mRNA expression of ANP, β-MHC and α-SKA stimulated by IL-1β, TNF-α or Ang II, demonstrating the broad mechanistic basis of the potent anti-hypertrophic effect of VCP746. This study has shown that the novel A1 AR agonist, VCP746, is able to attenuate cardiac myocyte hypertrophy. As such, VCP746 is potentially useful as a pharmacological agent in attenuating cardiac remodelling, especially in the post-myocardial infarction setting, given its previously established cytoprotective properties.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

Hesperetin protects against inflammatory response and cardiac fibrosis in postmyocardial infarction mice by inhibiting nuclear factor κB signaling pathway

Cardiac inflammation and cardiac fibrosis are important parts of cardiac remodeling following myocardial infarction (MI), which may be the basic mechanisms of the development of chronic heart failure. The nuclear factor (NF)-κB signaling pathway promotes cardiac inflammation and fibrosis. It has reported that hesperetin inhibits cardiac remodeling induced by pressure overload in mice. However, it has remained elusive whether and how hesperetin has a role in cardiac fibrosis post-MI. Therefore, a mouse model of MI was established by left anterior descending coronary artery ligation. Mice received hesperetin (30 mg/kg/day) or vehicle after surgery. After 8 weeks, all mice underwent echocardiography to evaluate cardiac function. Gene expression of cardiac fibrosis markers such as connective tissue growth factor (CTGF) as well as collagen I and III, and histological analysis were applied to determine the level of cardiac fibrosis. The expression of inflammatory markers such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were assessed by reverse-transcription quantitative PCR and ELISA, and activation of the NF-κB signaling pathway was detected by western blot analysis. It was found that hesperetin reduced the expression levels of TNF-α, IL-1β, IL-6 and CTGF as well as collagen I and III. The level of collagen deposition in post-MI myocardium was attenuated with the treatment of hesperetin. In additionally, administration of hesperetin inhibited the activation of the NF-κB signaling pathway. These findings indicated that hesperetin may inhibit cardiac inflammation post-MI through blocking the NF-κB signaling pathway, which may be a key mechanism via which hesperetin attenuates cardiac fibrosis.

Myoblast transplantation improves cardiac function after myocardial infarction through attenuating inflammatory responses

Myocardial infarction (MI) is a highly prevalent cardiac emergency, which results in adverse cardiac remodeling and then exacerbates progressive heart failure. Inflammatory responses in cardiac tissue after MI is necessary for myocardium repair and wound healing. However, the excessive inflammation is also a key component of subsequent heart failure pathology. Myoblast transplantation after MI have been fulfilled attractive effects on cardiac repair, but the complications of transplantation and the underlying mechanisms have not been fully elucidated. Here, we found that human myoblast transplantation into minipig myocardium decreased the infiltration of inflammatory cells, the expression levels of many pro-inflammatory genes and the activation of inflammation-related signal pathways, while upregulated the expression levels of anti-inflammatory genes such as IL-10 in cardiac tissue of minipig post-MI, which was contributed to the improved cardiac function, the decreased infarct area and the attenuated myocardial fibrosis. Moreover, co-culture of human myoblasts inhibited the production of IL-1β and TNF-α as well as activation of MAPK and NF-κB signaling pathway induced by damage-associated molecular patterns such as HMGB1 and HSP60 in human THP-1 cells, which was partially attributed to the up-regulated production of IL-10. Collectively, these results indicate that myoblast transplantation ameliorates heart injury and improves cardiac function post-MI through inhibiting the inflammatory response, which provides the novel mechanism for myoblast transplantation therapy of MI.

The Protective Effects of Ivabradine in Preventing Progression from Viral Myocarditis to Dilated Cardiomyopathy

To study the beneficial effects of ivabradine in dilated cardiomyopathy (DCM) mice, which evolved from coxsackievirus B3-induced chronic viral myocarditis. Four-to-five-week-old male balb/c mice were inoculated intraperitoneally with coxsackievirus B3 (Strain Nancy) on days 1, 14, and 28. The day of the first virus inoculation was defined as day 1. Thirty-five days later, the surviving chronic viral myocarditis mice were divided randomly into two groups, a treatment group and an untreated group. Ivabradine was administered by gavage for 30 consecutive days in the treatment group, and the untreated group was administered normal saline. Masson’s trichrome stain was used to evaluate the fibrosis degree in myocardial tissue. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), collagen I, collagen III and p38-MAPK signaling pathway proteins were detected by Western blot. Electrocardiogram was used to investigate the heart rate and rhythm. The thickness of the ventricular septum and left ventricular posterior wall, left ventricular end diastolic dimension, left ventricular end systolic dimension, left ventricular ejection fractions and fractional shortening were studied by echocardiography. Compared with the untreated chronic viral myocarditis mice, ivabradine significantly increased the survival rate, attenuated the myocardial lesions and fibrosis, improved the impairment of the left ventricular function, diminished the heart dimension, decreased the production of collagen I and collagen III, reduced the expression of the proinflammatory cytokines TNF-α, IL-1β, and IL-6, and lowered the production of phospho-p38 MAPK. The findings indicate the therapeutic effect of ivabradine in preventing the progression from viral myocarditis to DCM in mice with chronic viral myocarditis induced by coxsackievirus B3, is associated with inhibition of the p38 MAPK pathway, downregulated inflammatory responses and decreased collagen expression. Ivabradine appears a promising approach for the treatment of patients with viral myocarditis.