Inflammatory Cytokines and Postmyocardial Infarction Remodeling

Immune and inflammatory mechanism of remote ischemic conditioning: A narrative review

The benefits of remote ischemic conditioning (RIC) on multiple organs have been extensively investigated. According to existing research, suppressing the immune inflammatory response is an essential mechanism of RIC. Based on the extensive effects of RIC on cardiovascular and cerebrovascular diseases, this article reviews the immune and inflammatory mechanisms of RIC and summarizes the effects of RIC on immunity and inflammation from three perspectives: (1) the mechanisms of the impact of RIC on inflammation and immunity; (2) evidence of the effects of RIC on immune and inflammatory processes in ischaemic stroke; and (3) possible future applications of this effect, especially in systemic infectious diseases such as sepsis and sepsis-associated encephalopathy. This review explores the possibility of using RIC as a treatment in more inflammation-related diseases, which will provide new ideas for the treatment of this kind of disease.

Vanillin and pentoxifylline ameliorate isoproterenol-induced myocardial injury in rats via the Akt/HIF-1α/VEGF signaling pathway

Myocardial infarction (MI) is a major health problem associated with high morbidity and mortality. Recently, angiogenesis has emerged as a novel therapeutic approach against ischemic diseases including MI. Therefore, we aimed to investigate the potential angiogenic effects of vanillin (Van) both alone and in combination with pentoxifylline (PTX), and to examine the molecular mechanisms through which Van and PTX may ameliorate cardiac injury induced in rats including their effects on oxidative stress, inflammation and apoptosis which play a key role in MI pathogenesis. MI was induced in rats using isoproterenol (ISO) (150 mg kg^-1, SC, twice at a 24 h interval). Then, rats were treated orally with Van (150 mg kg^-1 day^-1), PTX (50 mg kg^-1 day^-1) or Van + PTX combination. ISO-induced cardiac injury was characterized by cardiac hypertrophy, ST-segment elevation and elevated serum levels of troponin-I, creatine kinase-MB and lactate dehydrogenase. Cardiac levels of the antioxidant markers GSH and SOD and the antiapoptotic protein Bcl-2 were decreased. On the other hand, cardiac levels of the oxidative stress marker malonaldehyde, the inflammatory cytokines TNF-α, IL-6 and IL-1β, the proapoptotic protein Bax, and caspase-3 were increased. Moreover, the cardiac levels of p-Akt and HIF-1α and the mRNA expression levels of the angiogenic genes VEGF, FGF-2 and ANGPT-1 were increased. Treatment with either Van or PTX ameliorated ISO-induced changes and further upregulated Akt/HIF-1α/VEGF signaling. Furthermore, Van + PTX combination was more effective than monotherapy. These findings suggest a novel therapeutic potential of Van and PTX in ameliorating MI through enhancing cardiac angiogenesis and modulating oxidative stress, inflammation and apoptosis.

Epicardial fat volume assessed with cardiac magnetic resonance imaging in patients with Takotsubo cardiomyopathy

PURPOSE

The aims of our study were to investigate with cardiovascular magnetic resonance (CMR) the role of Epicardial Fat Volume (EFV) and distribution in patients with Takotsubo cardiomyopathy (TTC). Moreover, we explored EFV in patients with TTC and related this to comorbidities, cardiac biomarkers, and cardiac function.

METHODS

This retrospective study performed CMR scans in 30 consecutive TTC patients and 20 healthy controls. The absolute amount of EFV was quantified in consecutive short-axis cine stacks through the modified Simpson's rule. In addition, the left atrio-ventricular groove (LV) and right ventricle (RV) Epicardial Fat Thickness (EFT) were measured as well. Besides epicardial fat, LV myocardial strain parameters and T2 mapping measurements were obtained.

RESULTS

TTC patients and controls were of comparable age, sex, and body mass index. Compared to healthy controls, patients with TTC demonstrated a significantly increased EFV, epicardial fat mass, and EFV indexed for body 7surface area (p = 0.005; p = 0.003; p = 0.008; respectively). In a multiple regression model including age, sex, BMI, atrial fibrillation, and dyslipidemia, TTC remained an independent association with EFV (p = 0.008). Global T2 mapping and Global longitudinal strain in patients with TTC were correlated with EFV (r = 0.63, p = 0.001, and r = 0.44, p = 0.02, respectively).

CONCLUSION

Patients with TTC have increased EFV compared to healthy controls, despite a similar body mass index. The amount of epicardial fat was associated with CMR markers of myocardial inflammation and subclinical contractile dysfunction.

Peli1 deletion in macrophages attenuates myocardial ischemia/reperfusion injury by suppressing M1 polarization

The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammatory response following myocardial ischemia/reperfusion injury. Peli1, an E3 ubiquitin ligase, is closely associated with inflammation and autoimmunity as an important regulatory protein in the Toll-like receptor signaling pathway. We aimed to explore the function of Peli1 in macrophage polarization under myocardial ischemia/reperfusion injury and elucidate the possible mechanisms. We show here that Peli1 is upregulated in peripheral blood mononuclear cells from patients with myocardial ischemia/reperfusion, which is correlated with myocardial injury and cardiac dysfunction. We also found that the proportion of M1 macrophages was reduced and myocardial infarct size was decreased, paralleling improvement of cardiac function in mice with Peli1 deletion in hematopoietic cells or macrophages. Macrophage Peli1 deletion lessened M1 polarization and reduced the migratory ability in vitro. Mechanistically, Peli1 contributed to M1 polarization by promoting K63-linked ubiquitination and nuclear translocation of IRF5. Moreover, Peli1 deficiency in macrophages reduced the apoptosis of cardiomyocytes in vivo and in vitro. Together, our study demonstrates that Peli1 deficiency in macrophages suppresses macrophage M1 polarization and alleviates myocardial ischemia/reperfusion injury by inhibiting the nuclear translocation of IRF5, which may serve as a potential intervention target for myocardial ischemia/reperfusion injury.

Periodontal Disease Associated With Interstitial Myocardial Fibrosis: The Multiethnic Study of Atherosclerosis

Background Periodontitis is a chronic inflammatory disease common among adults. It has been suggested that periodontal disease (PD) may be a contributing risk factor for cardiovascular disease; however, pathways underlying such a relationship require further investigation. Methods and Results A total of 665 men (mean age 68±9 years) and 611 women (mean age 67±9 years) enrolled in the MESA (Multiethnic Study of Atherosclerosis) underwent PD assessment using a 2-item questionnaire at baseline (2000-2002) and had cardiovascular magnetic resonance 10 years later. PD was defined when participants reported either a history of periodontitis or gum disease or lost teeth caused by periodontitis or gum disease. Multivariable linear regression models were constructed to assess the associations of baseline self-reported PD with cardiovascular magnetic resonance-obtained measures of interstitial myocardial fibrosis (IMF), including extracellular volume and native T1 time. Men with a self-reported history of PD had greater extracellular volume percent (ß=0.6%±0.2, P=0.01). This association was independent of age, left ventricular mass, traditional cardiovascular risk factors, and history of myocardial infarction. In a subsequent model, substituting myocardial infarction for coronary artery calcium score, the association of PD with IMF remained significant (ß=0.6%±0.3, P=0.03). In women, a self-reported history of PD was not linked to higher IMF. Importantly, a self-reported history of PD was not found to be associated with myocardial scar independent of sex (odds ratio, 1.01 [95% CI, 0.62-1.65]; P=0.9). Conclusions In a community-based setting, men but not women with a self-reported PD history at baseline were found to be associated with increased measures of IMF. These findings support a plausible link between PD, a proinflammatory condition, and subclinical IMF.

Autonomic nervous system and cardiac neuro-signaling pathway modulation in cardiovascular disorders and Alzheimer's disease

The heart is a functional syncytium controlled by a delicate and sophisticated balance ensured by the tight coordination of its several cell subpopulations. Accordingly, cardiomyocytes together with the surrounding microenvironment participate in the heart tissue homeostasis. In the right atrium, the sinoatrial nodal cells regulate the cardiac impulse propagation through cardiomyocytes, thus ensuring the maintenance of the electric network in the heart tissue. Notably, the central nervous system (CNS) modulates the cardiac rhythm through the two limbs of the autonomic nervous system (ANS): the parasympathetic and sympathetic compartments. The autonomic nervous system exerts non-voluntary effects on different peripheral organs. The main neuromodulator of the Sympathetic Nervous System (SNS) is norepinephrine, while the principal neurotransmitter of the Parasympathetic Nervous System (PNS) is acetylcholine. Through these two main neurohormones, the ANS can gradually regulate cardiac, vascular, visceral, and glandular functions by turning on one of its two branches (adrenergic and/or cholinergic), which exert opposite effects on targeted organs. Besides these neuromodulators, the cardiac nervous system is ruled by specific neuropeptides (neurotrophic factors) that help to preserve innervation homeostasis through the myocardial layers (from epicardium to endocardium). Interestingly, the dysregulation of this neuro-signaling pathway may expose the cardiac tissue to severe disorders of different etiology and nature. Specifically, a maladaptive remodeling of the cardiac nervous system may culminate in a progressive loss of neurotrophins, thus leading to severe myocardial denervation, as observed in different cardiometabolic and neurodegenerative diseases (myocardial infarction, heart failure, Alzheimer's disease). This review analyzes the current knowledge on the pathophysiological processes involved in cardiac nervous system impairment from the perspectives of both cardiac disorders and a widely diffused and devastating neurodegenerative disorder, Alzheimer's disease, proposing a relationship between neurodegeneration, loss of neurotrophic factors, and cardiac nervous system impairment. This overview is conducive to a more comprehensive understanding of the process of cardiac neuro-signaling dysfunction, while bringing to light potential therapeutic scenarios to correct or delay the adverse cardiovascular remodeling, thus improving the cardiac prognosis and quality of life in patients with heart or neurodegenerative disorders.

Long-Term Trajectories of High-Sensitivity C-Reactive Protein Level Among Patients with Acute Heart Failure

Background

Inflammation contributes to the progression of heart failure (HF). However, long-term inflammatory trajectories and their associations with outcomes in patients with acute HF remain unclear.

Methods

Data was obtained from the China Patient-Centered Evaluative Assessment of Cardiac Events Prospective Heart Failure Study, and high-sensitivity C-reactive protein (hsCRP) was used to reflect the inflammatory level. Only patients who survived over 12-month and had hsCRP data at admission, 1-, and 12-month after discharge were included. The latent class trajectory modeling was used to characterize hsCRP trajectories. Multivariable Cox regression models were used to explore the association between hsCRP trajectories and following mortality.

Results

Totally, 1281 patients with a median 4.77 (interquartile range [IQR]: 4.24-5.07) years follow-up were included. The median age was 64 years (IQR: 54-73 years); 453 (35.4%) were female. Four distinct inflammatory trajectories were characterized: persistently low (n = 419, 32.7%), very high-marked decrease (n = 99, 7.7%), persistently high (n = 649, 50.7%), and persistently very high (n = 114, 8.9%). Compared with the persistently low trajectory, the all-cause mortality was increased in a graded pattern in the persistently high (hazard ratio [HR]: 1.59, 95% confidence interval [CI]: 1.23-2.07) and persistently very high (HR: 2.56, 95% CI: 1.83-3.70) trajectories; nevertheless, the mortality was not significantly increased in very high-marked decrease trajectory (HR: 0.94, 95% CI: 0.57-1.54).

Conclusion

Four distinct inflammatory trajectories were identified among patients with acute HF who survived over 12-month. Patients with persistently high and very high trajectories had significantly higher mortality than those with the persistently low trajectory.

Progranulin (PGRN) as a regulator of inflammation and a critical factor in the immunopathogenesis of cardiovascular diseases

Immune dysregulation has been identified as a critical cause of the most common types of cardiovascular diseases (CVDs). Notably, the innate and adaptive immune responses under physiological conditions are typically regulated with high sensitivity to avoid the exacerbation of inflammation, but any dysregulation can probably be associated with CVDs. In this respect, progranulin (PGRN) serves as one of the main components of the regulation of inflammatory processes, which significantly contributes to the immunopathogenesis of such disorders. PGRN has been introduced among the secreted growth factors as one related to wound healing, inflammation, and human embryonic development, as well as a wide variety of autoimmune diseases. The relationship between the serum PGRN and TNF-α ratio with the spontaneous bacterial peritonitis constitute one of the independent predictors of these conditions. The full-length PGRN can thus effectively reduce the calcification of valve interstitial cells, and the granulin precursor (GRN), among the degradation products of PGRN, can be beneficial. Moreover, it was observed that, PGRN protects the heart against ischemia-reperfusion injury. Above all, PGRN also provides protection in the initial phase following myocardial ischemia-reperfusion injury. The protective impact of PGRN on this may be associated with the early activation of the PI3K/Akt signaling pathway. PGRN also acts as a protective factor in hyperhomocysteinemia, probably by down-regulating the wingless-related integration site Wnt/β-catenin signaling pathway. Many studies have further demonstrated that SARS-CoV-2 (COVID-19) has dramatically increased the risks of CVDs due to inflammation, so PGRN has drawn much more attention among scholars. Lysosomes play a pivotal role in the inflammation process, and PGRN is one of the key regulators in their functioning, which contributes to the immunomodulatory mechanism in the pathogenesis of CVDs. Therefore, investigation of PGRN actions can help find new prospects in the treatment of CVDs. This review aims to summarize the role of PGRN in the immunopathogenesis of CVD, with an emphasis on its treatment.

Novel fabrication of bioengineered injectable chitosan hydrogel loaded with conductive nanoparticles to improve therapeutic potential of mesenchymal stem cells in functional recovery after ischemic myocardial infarction

In recent decades, myocardial regeneration through stem cell transplantation and tissue engineering has been viewed as a promising technique for treating myocardial infarction. As a result, the researcher attempts to see whether co-culturing modified mesenchymal stem cells with Au@Ch-SF macro-hydrogel and H9C2 may help with tissue regeneration and cardiac function recovery. The gold nanoparticles (Au) incorporated into the chitosan-silk fibroin hydrogel (Au@Ch-SF) were validated using spectral and microscopic examinations. The most essential elements of hydrogel groups were investigated in detail, including weight loss, mechanical strength, and drug release rate. Initially, the cardioblast cells (H9C2 cells) was incubated with Au@Ch-SF macro-hydrogel, followed by mesenchymal stem cells (2 × 10⁵) were transplanted into the Au@Ch-SF macro-hydrogel+H9C2 culture at the ratio of 2:1. Further, cardiac phenotype development, cytokines expression and tissue regenerative performance of modified mesenchymal stem cells treatment were studied through various in vitro and in vivo analyses. The Au@Ch-SF macro-hydrogel gelation time was much faster than that of Ch and Ch-SF hydrogels, showing that Ch and SF exhibited greater intermolecular interactions. The obtained Au@Ch-SF macro-hydrogel has no toxicity on mesenchymal stem cells (MS) or cardiac myoblast (H9C2) cells, according to the biocompatibility investigation. MS cells co-cultured with Au@Ch-SF macro-hydrogel and H9C2 cells also stimulated cardiomyocyte fiber restoration, which has been confirmed in myocardial infarction rats using -MHC and Cx43 myocardial indicators. We developed a novel method of co-cultured therapy using MS cells, Au@Ch-SF macro-hydrogel, and H9C2 cells which could promote the regenerative activities in myocardial ischemia cells. These study findings show that co-cultured MS therapy might be effective for the treatment of myocardial injury.

Unfavorable left ventricular remodeling due to experience of chronic sleep restriction after myocardial infarction: The role of matrix metalloproteinases & oxidative stress

Disturbed sleep or sleep loss due to vocational or lifestyle changes following MI is a common problem that may affect many physiological processes involved in left ventricle (LV) remodeling. Herein, we proposed that experience of sleep disruption and/or restriction after myocardial infarction (MI) may aggravate cardiac extracellular matrix remodeling and induce apoptosis in the cardiomyocytes. MI was induced in adult male rats by permanent ligation of the left anterior descending coronary artery. Twenty-four hours after surgery, some animals experienced chronic sleep restriction (CSR) for 6 days. Serum levels of CK-MB, PAB, and TNF-α were evaluated at days 1, 8, and 21 postsurgery. Twenty-one days after surgery, hemodynamic parameters and expression of MMP-2, MMP-9, TIMP-1, and TNF-α, as well as myocardial fibrosis and apoptosis in the noninfarcted area of the LV were assessed. Our results showed a clear decrease in serum concentrations of CK-MB, PAB and TNF-α at day 21 postsurgery in the MI group as compared to MI+SR animals in which these markers remained at high levels. CSR following MI deteriorated LV hemodynamic indexes and also impaired the balance between MMPs and TIMP-1. Further, it yielded an increase in oxidant and inflammatory state which caused deleterious fibrotic and apoptotic effects on cardiomycytes. Our data suggest post-MI sleep loss may cause adverse LV remodeling due to increased inflammatory reactions as well as oxidative burden and/or anti-oxidative insufficiency that in turn impede the balance between MMPs and their inhibitors.

Pharmacological treatment of cardiogenic shock - A state of the art review

Cardiogenic shock is a clinical syndrome of impaired tissue perfusion caused by primary cardiac dysfunction and inadequate cardiac output. It represents one of the most lethal clinical conditions in intensive care medicine with mortality >40%. Management of different clinical presentations of cardiogenic shock includes guidance of cardiac preload, afterload, heart rate and contractility by differential pharmacological modulation of volume, systemic and pulmonary vascular resistance and cardiac output besides reversing the triggering cause. Data from large registries and randomized controlled trials on optimal diagnostic guidance as well as choice of pharmacological agents has accrued significantly in recent years. This state-of-the-art review summarizes the basic concepts of cardiogenic shock, the diagnostic work-up and currently available evidence and guideline recommendations on pharmacological treatment of cardiogenic shock.

The role of γδ T17 cells in cardiovascular disease

Due to the ability of γδ T cells to bridge adaptive and innate immunity, γδ T cells can respond to a variety of molecular cues and acquire the ability to induce a variety of cytokines such as IL-17 family, IFN-γ, IL-4, and IL-10. IL-17⁺ γδ T cells (γδ T17 cells) populations have recently received considerable interest as they are the major early source of IL-17A in many immune response models. However, the exact mechanism of γδ T17 cells is still poorly understood, especially in the context of cardiovascular disease (CVD). CVD is the leading cause of death in the world, and it tends to be younger. Here, we offer a review of the cardiovascular inflammatory and immune functions of γδ T17 cells in order to understand their role in CVD, which may be the key to developing new clinical applications.

Chick early amniotic fluid component improves heart function and protects against inflammation after myocardial infarction in mice

Myocardial infarction (MI) is the major cause of mortality around the world. We recently demonstrated that chick early amniotic fluid (ceAF) can effectively rescue ischemic heart injury, indicating that it has a therapeutic function in MI. However, its functional components and the underlying mechanisms remain to be clarified. Here, we demonstrated that a fraction of ceAF, peak 8 (P8), had a protective effect on acute MI. P8 significantly decreased cardiomyocyte cross-sectional areas and cardiomyocyte apoptosis in MI mice. Using a human embryonic stem cell-derived cardiomyocyte model, which was subjected to hypoxia and reoxygenation, mimicking MI state, we found that P8 treatment reduced apoptosis and reversed myocardial contractility. Mechanistically, P8 improved cardiac function by inhibiting NF-κB signaling and downregulating inflammatory cytokine expression. Using mass spectrometry, we identified that guanosine and deoxynucleoside were the main functional components of P8 that suppressed the inflammatory response in human embryonic stem cell-derived cardiomyocytes. Collectively, our data suggest that specific components from ceAF are promising therapeutic agents for ischemic heart injury and could be a potential supplement to current medications for MI.

Novel Therapeutic Approaches Enhance PGC1-alpha to Reduce Oxidant Stress-Inflammatory Signaling and Improve Functional Recovery in Hibernating Myocardium

Ischemic heart disease affects millions of people around the world. Current treatment options, including coronary artery bypass grafting, do not result in full functional recovery, highlighting the need for novel adjunctive therapeutic approaches. Hibernation describes the myocardial response to prolonged ischemia and involves a set of complex cytoprotective metabolic and functional adaptations. PGC1-alpha, a key regulator of mitochondrial energy metabolism and inhibitor of oxidant-stress-inflammatory signaling, is known to be downregulated in hibernating myocardium. PGC1-alpha is a critical component of cellular stress responses and links cellular metabolism with inflammation in the ischemic heart. While beneficial in the acute setting, a chronic state of hibernation can be associated with self-perpetuating oxidant stress-inflammatory signaling which leads to tissue injury. It is likely that incomplete functional recovery following revascularization of chronically ischemic myocardium is due to persistence of metabolic changes as well as prooxidant and proinflammatory signaling. Enhancement of PGC1-alpha signaling has been proposed as a possible way to improve functional recovery in patients with ischemic heart disease. Adjunctive mesenchymal stem cell therapy has been shown to induce PGC1-alpha signaling in hibernating myocardium and could help improve clinical outcomes for patients undergoing bypass surgery.

E3 ubiquitin ligase RNF5 attenuates pathological cardiac hypertrophy through STING

Ring-finger protein 5 (RNF5) is an E3 ubiquitin ligase which is expressed in a variety of human tissues. RNF5 is involved in the regulation of endoplasmic reticulum stress, inflammation, and innate immunity and plays an important role in the occurrence and development of various tumors. However, the role of RNF5 in cardiac hypertrophy has not been reported. In this study, we found the expression of RNF5 was increased in the hearts of mice with pathological cardiac hypertrophy. The loss-of-function research demonstrated that RNF5 deficiency exacerbated cardiac hypertrophy, whereas gain-of-function studies revealed that overexpression of RNF5 had opposite effects. The stimulator of interferon genes (STING) is a signaling molecule that can activate type I interferon immunity, which can meditate inflammation and immune response in many diseases. The protein-protein interaction experiments confirmed that STING interacted with RNF5. Further studies showed that RNF5 inhibited cardiac hypertrophy by promoting STING degradation through K48-linked polyubiquitination. Therefore, we defined RNF5 as importantly regulated signaling for cardiac hypertrophy.

Addition of TyG index to the GRACE score improves prediction of adverse cardiovascular outcomes in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention: A retrospective study

Background

The Global Registry of Acute Coronary Events (GRACE) score is a widely recognized tool for predicting adverse cardiovascular events in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). The triglyceride-glucose index (TyG index) is a new biomarker of insulin resistance and has a close association with the occurrence of adverse cardiovascular events. We investigated whether the addition of the TyG index to the GRACE score could improve prognosis prediction in patients with NSTE-ACS undergoing percutaneous coronary intervention (PCI).

Methods

In total, 515 patients with NSTE-ACS undergoing PCI were included in this retrospective study. Kaplan-Meier analysis was performed to describe the cumulative incidence of the primary endpoint based on the median TyG index. The relationship between the TyG index and GRACE score was analyzed using Spearman's rank correlation. Univariate and multivariate Cox proportional hazards analyses were used to identify independent risk factors. Based on the receiver operating characteristic curve, net reclassification improvement (NRI), integrated differentiation improvement (IDI), and decision curve analysis, the TyG index was evaluated for its predictive value when added to the GRACE score. ROC curve analyses, NRI, and IDI were used to compare the gain effect of the TyG index and the levels of HbA1C, FBG, TG, and LDL-C on the GRACE score for predicting adverse cardiovascular events.

Results

The TyG index was an independent predictor of 2-year adverse cardiovascular events in patients with NSTE-ACS undergoing PCI. The addition of the TyG index to the GRACE score demonstrated an improved ability to predict 2-year adverse cardiovascular events compared with the GRACE score alone (AUCs: GRACE score 0.798 vs. GRACE score+TyG index 0.849, P = 0.043; NRI = 0.718, P < 0.001; IDI = 0.086, P < 0.001). The decision curve analysis suggested that the clinical net benefit of the new model (GRACE score+TyG index) was superior to that of the GRACE score alone, with a probability range of 0.04 to 0.32. When including the TyG index, HbA1C, FBG, TG, and LDL-C in the GRACE score system, we found that the TyG index had a greater incremental impact on risk prediction and stratification compared to the other parameters.

Conclusion

Combining the TyG index and GRACE score could improve the prediction of 2-year adverse cardiovascular events. This new risk model could identify patients with NSTE-ACS at higher risk of adverse events following PCI so that they can be monitored more carefully.

Hypoxic preconditioned aged BMSCs accelerates MI injury repair by modulating inflammation, oxidative stress and apoptosis

The benefits of autologous cell therapy for cardiac repair are diminished in aged individuals due to the limited quality and poor tolerance of aged stem cells in the ischemic micro-environment. The safe and efficient methods to improve the therapeutic effect of aged stem cells are needed to treat the increasing number of aged patients with cardiac diseases. In the present study, we aimed to determine whether hypoxic preconditioning can improve the therapeutic effect of aged stem cells even if the responsiveness of aged MSCs is poor, and to seek the underlying mechanism. Using a murine model of MI, our results showed that hypoxic preconditioning promoted the therapeutic effect of aged BMSCs, which was expressed in improved cardiac function, decreased scar size and alleviated cardiac remodeling in vivo. This in vivo effect of hypoxic preconditioned aged BMSCs was associated with alleviated inflammation, oxidative stress and apoptosis in infarcted heart. In vitro studies confirmed that hypoxic preconditioned aged BMSCs exert cytoprotective impacts on H9C2 cells against lethal hypoxia injury via attenuating oxidative stress and apoptosis. Our data support the promise of hypoxic preconditioning as a potential strategy to improve autologous stem cell therapy for ischemic heart injury in aged individuals.

Olive oil protects against progression of heart failure by inhibiting remodeling of heart subsequent to myocardial infarction in rats

We examined the beneficial effects of olive oil against heart failure post-myocardial infarction (PMI), induced by coronary artery ligation in rats. Animals were divided into sham and ligated groups and fed either regular chow, olive oil (10% wt/wt), or corn oil (10% wt/wt) and were followed up to 16 weeks. On the echocardiography at 3 days (PMI), in the ligated regular chow (LRC), ligated olive oil (LOO), and ligated corn oil (LCO) left ventricular ejection fraction (LVEF) decrease was 12.14%, 16.42%, and 17.53% from the baseline, respectively. However, only LOO group improved LVEF significantly at 16 weeks PMI and became comparable with all sham groups. Both scar formation and collagen deposition at 16 weeks PMI were less pronounced in the LOO group. Myocardial TNF-α level at 4 weeks of PMI increased by 176%, 11%, and 181% in the LRC, LOO, and LCO groups, respectively. Plasma TNF-α levels in LOO were significantly lower than LRC group after 4 weeks of PMI. Myocardial redox ratio (reduced glutathione/oxidized glutathione) decreased at 4 weeks PMI by 44.4%, 16.4%, and 36.9% in the LRC, LOO, and LCO groups, respectively, compared to the baseline. These changes in the redox ratio at 16 weeks PMI were further exacerbated in the LRC and LCO groups. Lipid hydroperoxides formation increased at 4 weeks PMI by 137.4%, 14.6%, and 97.1% in the LRC, LOO, and LCO groups, respectively. Since coronary artery ligation decreased left ventricular ejection fraction, increased myocardial TNF-α and oxidative stress, and since olive oil was able to inhibit these effects, it is proposed that dietary olive oil modulates cardiac remodeling and heart failure subsequent to myocardial infarction.

Meta-analysis reveals inhibition of the inflammatory cytokine IL-6 affords limited protection post-myocardial ischemia/infarction

Background

Proinflammatory cytokine cascades play crucial roles in the onset and progression of myocardial ischemia and infarction. Clinically, elevated serum levels of pro-inflammatory cytokine interleukin-6 is a poor prognostic indicator for future cardiac events and cardiac morbidity. Despite several reports, there is no clear evidence of cardiac benefits of inhibiting IL-6 in pre-clinical and clinical settings.

Objective

To analyze the available data systematically and perform a meta-analysis to show the evidence of effects of IL-6 inhibition on cardiac remodeling and mortality in ischemic animal models.

Methods

We used PICO framework and the quality of the studies was assessed using SYRCLE's risk of bias tool. Studies with interventions i.e., genetic deletion or pharmacological inhibition of IL-6/IL-6R were included for the meta-analysis. Systematic review was synthesized by including pre-clinical as well as randomized clinical trials involving myocardial infarction patients treated with IL-6 inhibitors. The effect size of the pooled data was determined using standard mean difference and 95% confidence intervals.

Results

A total of 12 pre-clinical studies were included in the review for analysis. Most of the studies showed an unclear risk of bias as the selection and reporting criteria were poorly described. We observed high heterogeneity in the included studies due to the varying duration of myocardial infarction and the dosage of IL-6 antibodies used in the studies. Overall inhibition of IL-6 significantly increased area at risk [p = 0.001, SMD = 0.49 (95% CI: -0.36, 1.35)] and significantly reduced ejection fraction [p = 0.001, SMD = -0.19 (95% CI: -1.39, 1.01)] and end-diastolic diameter [p = 0.02, SMD = -0.25 (95% CI: -0.87, 0.36)] of left ventricle post-MI, but no effects on infarct size [p < 0.01, SMD = 0.00; 95% CI: -1.34, 0.58). In randomized clinical trials, the overall effect on C-reactive protein remains significantly unchanged on CRP levels (SMD = -0.38; 95% CI: -1.94, 0.55) post-treatment with IL-6R inhibitor tocilizumab. The meta-regression demonstrates a significant positive correlation (p = 0.058) between the increase in ischemic area and duration of ischemia post-surgery in the absence of IL-6. This meta-analysis indicates mixed effect of IL-6 inhibition on cardiac remodeling post-MI, particularly in protecting the myocardium viability from damaging acute inflammation but not significant on cardiac function of ischemic animal models.

Conclusion

Despite the well-established pro-inflammatory nature of IL-6 in myocardial ischemia, our meta-analysis reports a limited contribution of IL-6 in the cardiac remodeling of hearts in animal models of myocardial ischemia. Moreover, genetically deleted IL-6 murine models produced contrasting results. Additional pre-clinical studies exploring the pharmacological inhibition of IL-6R are required to determine the beneficial effects of IL-6 inhibitors in regulating cardiac remodeling. The findings from IL-6R inhibition have better clinical relevance compared to genetically inhibited IL-6.

Left Ventricular Remodeling after Myocardial Infarction: From Physiopathology to Treatment

Myocardial infarction (MI) is the leading cause of death and morbidity worldwide, with an incidence relatively high in developed countries and rapidly growing in developing countries. The most common cause of MI is the rupture of an atherosclerotic plaque with subsequent thrombotic occlusion in the coronary circulation. This causes cardiomyocyte death and myocardial necrosis, with subsequent inflammation and fibrosis. Current therapies aim to restore coronary flow by thrombus dissolution with pharmaceutical treatment and/or intravascular stent implantation and to counteract neurohormonal activation. Despite these therapies, the injury caused by myocardial ischemia leads to left ventricular remodeling; this process involves changes in cardiac geometry, dimension and function and eventually progression to heart failure (HF). This review describes the pathophysiological mechanism that leads to cardiac remodeling and the therapeutic strategies with a role in slowing the progression of remodeling and improving cardiac structure and function.

D-pinitol attenuates isoproterenol induced myocardial infarction by alleviating cardiac inflammation, oxidative stress and ultrastructural changes in Swiss Albino mice

Cardiovascular diseases are the most disturbing problems throughout the world. The side effects of existing drugs are continuously compelling the scientist to look for better options in terms of safety, efficacy and cost-effectiveness. Our study is also a move in this direction. We have chosen D-pinitol to see its cardioprotective role in isoproterenol-induced myocardial infarction in Swiss Albino mice. Grouping was made by dividing mice into eight groups (n = 6). Group I - control; Group II - Isoproterenol (ISO) (150 mg/kg, i.p.); Group III - D-pinitol (PIN) (25 mg), Group IV - PIN (50 mg), Group V - PIN (100 mg) per kg per oral, respectively with ISO; Group VI - PIN _{per se} (100 mg D-pinitol only); Group VII - Propranolol (PRO) (20 mg/kg/oral) with ISO; and Group VIII - PRO _{per se} (20 mg/kg, p.o.). After 24 hrs of the last dose, the blood sample was collected for biochemical parameters, then mice were, euthanised through cervical dislocation under anesthesia and cardiac tissue was collected for biochemical, histopathological and ultrastructural evaluation. Administration of ISO in mice altered the level of antioxidant markers, cardiac injury markers and inflammatory markers, which were significantly restored towards normal by D-pinitol at the dose of 50 and 100 mg. 25 mg of D-pinitol dosage, did not produce significant cardio protection. The histopathological and ultrastructural analysis further confirmed these findings. Our study showed that D-pinitol significantly protected myocardial damage which was induced by ISO and reverted oxidative stress and inflammation considerably.

C-Reactive Protein Velocity (CRPv) as a New Biomarker for the Early Detection of Acute Infection/Inflammation

C-reactive protein (CRP) is considered a biomarker of infection/inflammation. It is a commonly used tool for early detection of infection in the emergency room or as a point-of-care test and especially for differentiating between bacterial and viral infections, affecting decisions of admission and initiation of antibiotic treatments. As C-reactive protein is part of a dynamic and continuous inflammatory process, a single CRP measurement, especially at low concentrations, may erroneously lead to a wrong classification of an infection as viral over bacterial and delay appropriate antibiotic treatment. In the present review, we introduce the concept of C-reactive protein dynamics, measuring the velocity of C-reactive protein elevation, as a tool to increase this biomarker’s diagnostic ability. We review the studies that helped define new metrics such as estimated C-reactive protein velocity (velocity of C-reactive protein elevation from symptoms’ onset to first C-reactive protein measurement) and the measured C-reactive protein velocity (velocity between sequential C-reactive protein measurements) and the use of these metrics in different clinical scenarios. We also discuss future research directions for this novel metric.

Threshold adjusted vagus nerve stimulation after asphyxial cardiac arrest results in neuroprotection and improved survival

BACKGROUND

Vagus nerve stimulation (VNS) has shown therapeutic potential in a variety of different diseases with many ongoing clinical trials. The role of VNS in reducing ischemic injury in the brain requires further evaluation. Cardiac arrest (CA) causes global ischemia and leads to the injury of vital organs, especially the brain. In this study, we investigated the protective effects of customized threshold-adjusted VNS (tVNS) in a rat model of CA and resuscitation.

METHODS

Sprague-Dawley rats underwent 12 min asphyxia-CA followed by resuscitation. Rats were assigned to either post-resuscitation tVNS for 2 h or no-tVNS (control). tVNS was applied by electrode placement in the left cervical vagus nerve. To optimize a threshold, we used animal's heart rate and determined a 15-20% drop from baseline levels as the effective and physiological threshold for each animal. The primary endpoint was 72 h survival; secondary endpoints included neurological functional recovery, reduction in brain cellular injury (histopathology), cardiac and renal injury parameters (troponin I and creatinine levels, respectively).

RESULTS

In comparison to the control group, tVNS significantly improved 72 h survival and brain functional recovery after 12 minutes of CA. The tVNS group demonstrated significantly reduced numbers of damaged neurons in the CA1 hippocampal region of the brain as compared to the control group. Similarly, the tVNS group showed decreased trend in plasma troponin I and creatinine levels as compared to the control group.

CONCLUSIONS

Our findings suggest that using tVNS for 2 h after 12 minutes of CA attenuates ischemia neuronal cell death, heart and kidney damage, and improves 72 h survival with improved neurological recovery.

Aib1 deficiency exacerbates inflammatory responses in acute myocardial infarction mice

Acute myocardial infarction (AMI) is one of the major causes of death throughout the world, while inflammation has been known as a major contributor to the pathophysiology of AMI. Inhibition of inflammation is shown to protect from AMI. Amplified in breast 1 (Aib1) is a transcriptional coactivator protein which can suppress inflammation. The anti-inflammatory activities of Aib1 imply its potential effects against AMI; however, to date the role of Aib1 in AMI has not been described yet. Here we explored the potential functions of Aib1 in AMI. We induced AMI in both wild-type (WT) and Aib1^-/- mice. The expression levels of Aib1 and inflammatory cytokines in the AMI WT mice were measured by RT-PCR and Western blot. The heart infarction area and cardiac functions were compared between the AMI WT and Aib1^-/- mice. The expression levels of inflammatory cytokines including IL-6, IL-1β, TNF-α, and MCP-1 in heart tissues were compared between the AMI WT and Aib1^-/- mice by ELISA and RT-PCR. AMI induced the production of inflammatory cytokines whereas suppressed the expression of Aib1 in WT mice. AMI Aib1^-/- mice displayed increased infarct area and aggravated heart dysfunction, as well as upregulated levels of Il-6, Il-1β, Tnf-α, and Mcp-1 in heart tissues. Aib1 deficiency exacerbates inflammation in AMI mice. KEY MESSAGES: AMI induced inflammation in the heart tissue of mice. Aib1 knockout exacerbated infarction in AMI mice. Aib1 knockout exacerbated cardiac dysfunction in AMI mice. Aib1 knockout exacerbated inflammation in AMI mice.

Flavonoid Extract from Propolis Provides Cardioprotection following Myocardial Infarction by Activating PPAR-γ

We have previously reported that flavonoid extract from propolis (FP) can improve cardiac function in rats following myocardial infarction (MI). However, the mechanisms responsible for the cardioprotective effects of FP have not been fully elucidated. In the current study, we explored whether FP can reduce inflammatory cytokines and attenuate sympathetic nerve system activity and antiendoplasmic reticulum (ER) stress and whether the cardioprotective effects are related to peroxisome proliferator-activated receptor gamma (PPAR-γ) activation. Sprague Dawley rats were randomly divided into six groups: Sham group received the surgical procedure but no artery was ligated; MI group received ligation of the left anterior descending (LAD) branch of the coronary artery; MI + FP group received FP (12.5 mg/kg/d, intragastrically) seven days prior to LAD ligation; FP group (Sham group + 12.5 mg/kg/d, intragastrically); MI + FP + GW9662 group received FP prior to LAD ligation with the addition of a specific PPAR-γ inhibitor (GW9662), 1 mg/kg/d, orally); and MI + GW9662 group received the PPAR-γ inhibitor and LAD ligation. The results demonstrated that the following inflammatory markers were significantly elevated following MI as compared with expression in sham animals: IL-1β, TNF-α, CRP; markers of sympathetic activation: plasma norepinephrine, epinephrine and GAP43, nerve growth factor, thyroid hormone; and ER stress response markers GRP78 and CHOP. Notably, the above changes were attenuated by FP, and GW9662 was able to alleviate the effect of FP. In conclusion, FP induces a cardioprotective effect following myocardial infarction by activating PPAR-γ, leading to less inflammation, cardiac sympathetic activity, and ER stress.

CircSLC8A1 Exacerbates Hypoxia-Induced Myocardial Injury via Interacting with MiR-214-5p to Upregulate TEAD1 Expression

Circular RNAs (circRNAs) act as important regulators in myocardial infarction (MI). This study aimed to explore the regulatory mechanism of circRNA solute carrier family 8 member A1 antisense RNA 1 (circSLC8A1) in hypoxia-induced myocardial injury.Exosomes were isolated by ultracentrifugation and identified by microscopic observation or protein detection. Protein levels were examined by Western blot. CircSLC8A1, microRNA-214-5p (miR-214-5p), and TEA domain transcription factor 1 (TEAD1) levels were determined via quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were analyzed by 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide (MTT) and flow cytometry, respectively. Inflammatory cytokines were measured using enzyme-linked immunosorbent assay (ELISA). Oxidative stress was assessed by reactive oxygen species (ROS) production, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity through the corresponding detection kits. Target analysis was performed by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, and pull-down assay.Exosomes released circSLC8A1 from hypoxic cardiomyocytes. Exosomal circSLC8A1 exacerbated hypoxia-induced repression of cell viability but promotion of cell apoptosis, inflammation, and oxidative stress. Knockdown of circSLC8A1 ameliorated hypoxia-mediated cell injury. CircSLC8A1 directly targeted miR-214-5p and miR-214-5p downregulation reverted the effects of si-circSLC8A1 on hypoxia-treated cardiomyocytes. TEAD1 was a target of miR-214-5p and circSLC8A1 upregulated TEAD1 level via targeting miR-214-5p. In addition, miR-214-5p inhibited hypoxia-caused cell injury by downregulating the expression of TEAD1.These results suggested that circSLC8A1 aggravated cell damages in hypoxia-treated cardiomyocytes by the regulation of TEAD1 via sponging miR-214-5p.

Interleukin-6 inhibition in ST-elevation myocardial infarction: Immune cell profile in the randomised ASSAIL-MI trial

Background

We recently showed that interleukin (IL)-6 inhibition by tocilizumab improves myocardial salvage in ST-elevation myocardial infarction (STEMI). However, the mechanisms for this effect are not clear.

Methods

In this exploratory sub-study of the ASSAIL-MI trial, we examined leukocyte differential counts and their relation to myocardial salvage and peak troponin T (TnT) in STEMI patients randomised to tocilizumab (n = 101) or placebo (n = 98). We performed RNA-sequencing on whole blood (n = 40) and T cells (n = 20). B and T cell subpopulations were examined by flow cytometry (n = 69).

Findings

(i) STEMI patients had higher neutrophil counts at hospitalisation compared with stable angina patients. (ii) After percutaneous coronary intervention there was a gradual decline in neutrophils, which was significantly more pronounced in the tocilizumab group. (iii) The decrease in neutrophils in the tocilizumab group was associated with improved myocardial salvage and lower peak TnT. (iv) RNA-sequencing suggested that neutrophil function was also attenuated by tocilizumab. (v) B and T cell sub-populations changed only minimally after STEMI with minor effects of tocilizumab, supported as well by RNA-sequencing analyses of T cells. (vi) However, a low CD8⁺ count was associated with improved myocardial salvage in patients admitted to the hospital > 3 h after symptom onset.

Interpretation

Tocilizumab induced a rapid reduction in neutrophils and seemed to attenuate neutrophil function in STEMI patients potentially related to the beneficial effects of tocilizumab on myocardial salvage.

Funding

South-Eastern Norway Regional Health Authority (Nos. 2019067, 2017084), the Central Norway Regional Health Authority and Norwegian Research Council (No. 283867).

Immune correlates of cardiovascular co-morbidity in HIV infected participants from South India

BACKGROUND

Understanding the immune correlates of cardiovascular disease (CVD) risk in HIV infection is an important area of investigation in the current era of aging with HIV infection. Less is known about CVD risk and HIV infection in developing nations where additional risk factors may be playing a role in the CVD development. In this study, we assessed the effects of systemic inflammation, microbial translocation (MT), T cell immune activation (IA), and nadir CD4 counts on cardiac function and arterial stiffness as markers of subclinical atherosclerosis in HIV-infected individuals.

METHODS

People with HIV (PWH) who were ART naïve (n = 102) or virally suppressed on ART (n = 172) were stratified on nadir CD4 counts and compared to HIV-uninfected controls (n = 64). Determination was made of cardiac function via radial pulse wave and carotid intima thickness (C-IMT) measurements. Plasma biomarkers of inflammation and MT by ELISA or multiplex assays, and immune activation (IA) of T cells based HLA-DR and CD38 expression were investigated by flow cytometry. T-test, Mann-Whitney U test, and Spearman correlation were used to analyze study parameters.

RESULTS

Reduction in cardiac function with lower cardiac ejection time (p < 0.001), stroke volume (p < 0.001), cardiac output (p = 0.007), higher arterial stiffness (p < 0.05) were identified in ART-naïve participants, compared to PWH on ART (p < 0.05). No significant difference in C-IMT values were noted. Higher inflammatory and MT markers were found in the ART-naïve group compared to treated group who were comparable to uninfected participants, except for having higher TNF-α (p < 0.001) and sCD14 (p < 0.001). Immune activation of CD4 and CD8 T-cells was greater in ART-naïve participants compared to ART-treated and uninfected controls (p < 0.05). Lower nadir CD4 counts, higher inflammation, and higher MT predicted poor cardiac measures in the ART-naïve with nadir CD4 < 200cells/mm³ manifesting the highest arterial stiffness, and lowest cardiac function, whereas ART-treated, even with nadir < 200 cells/mm³ were similar to uninfected in these measures.

CONCLUSIONS

In HIV-infected individuals, initiation of ART even at nadir of < 200 cells/mm³ may prevent or reverse cardiovascular disease outcomes that are easily measurable in low income countries.

Effects of IL-38 on Macrophages and Myocardial Ischemic Injury

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

Targeted neutrophil-mimetic liposomes promote cardiac repair by adsorbing proinflammatory cytokines and regulating the immune microenvironment

Acute myocardial infarction (MI) induces a sterile inflammatory response that may result in poor cardiac remodeling and dysfunction. Despite the progress in anti-cytokine biologics, anti-inflammation therapy of MI remains unsatisfactory, due largely to the lack of targeting and the complexity of cytokine interactions. Based on the nature of inflammatory chemotaxis and the cytokine-binding properties of neutrophils, we fabricated biomimetic nanoparticles for targeted and broad-spectrum anti-inflammation therapy of MI. By fusing neutrophil membranes with conventional liposomes, we fabricated biomimetic liposomes (Neu-LPs) that inherited the surface antigens of the source cells, making them ideal decoys of neutrophil-targeted biological molecules. Based on their abundant chemokine and cytokine membrane receptors, Neu-LPs targeted infarcted hearts, neutralized proinflammatory cytokines, and thus suppressed intense inflammation and regulated the immune microenvironment. Consequently, Neu-LPs showed significant therapeutic efficacy by providing cardiac protection and promoting angiogenesis in a mouse model of myocardial ischemia-reperfusion. Therefore, Neu-LPs have high clinical translation potential and could be developed as an anti-inflammatory agent to remove broad-spectrum inflammatory cytokines during MI and other neutrophil-involved diseases.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Soluble RAGE attenuates myocardial I/R injuries via FoxO3-Bnip3 pathway

Soluble receptor for advanced glycation end-products (sRAGE) was reported to inhibit cardiac apoptosis through the mitochondrial pathway during myocardial ischemia/reperfusion (I/R) injury. Meanwhile, the proapoptotic protein Bcl2 and adenovirus E1B 19-kDa-interacting protein 3 (Bnip3) was reported to mediate mitochondrial depolarization and be activated by the Forkhead box protein O3 (FoxO3a). Therefore, it is supposed that FoxO3a-Bnip3 pathway might be involved in the inhibiting effects of sRAGE on mitochondrial apoptosis during I/R. I/R surgery or glucose deprivation/reoxygenation was adopted to explore mitochondrial depolarization, apoptosis and related signaling pathways in mice hearts and cultured cardiomyocytes. The results showed that overexpression of sRAGE in cardiomyocytes dramatically improved cardiac function and reduced infarct areas in I/R treated mice. sRAGE inhibited mitochondrial depolarization and cardiac apoptosis during I/R, which correlated with reduced expression of Bnip3, Sirt2, phosphorylation of Akt and FoxO3a which translocated into nucleus in cultured cardiomyocytes. Either Sirt2 or FoxO3a silencing enhanced the inhibiting effects of sRAGE on mitochondrial depolarization induced by I/R in cultured cardiomyocytes. Meanwhile, overexpression or silencing of FoxO3a affected the inhibiting effects of sRAGE on Bnip3 and cleaved caspase-3 in cultured cardiomyocytes. Therefore, it is suggested that sRAGE inhibited I/R injuries via reducing mitochondrial apoptosis through the FoxO3a-Bnip3 pathway.

A dual crosslinked hydrogel-mediated integrated peptides and BMSC therapy for myocardial regeneration

The efficacy of myocardial regeneration strategies for myocardial infarction (MI) is significantly compromised by the complex structure and microenvironment of the myocardium. Although tissue engineering strategies based on cell therapy and/or pro-angiogenesis can somewhat improve cardiac function, the lack of proper myocardial materials that can withstand sustained deformability and adaptable mechanical properties severely affects myocardial wall integrity, systolic-diastolic cycles, and regeneration. Herein, we developed an integrated single "all-in-one" in situ dual crosslinking conductive hydrogel with favorable treatment properties termed as MaHA/B-G-SH/Fe³⁺ by ionic interactions and chemical covalency based on modified hyaluronic acid (HA), gelatin (G), and Fe³⁺. The resulting dual crosslinking dynamic hydrogel not only provides self-healing and mechanical properties adapted to the myocardial systolic-diastolic cycle with simultaneous electrical signal transmission to fibrous islands and normal tissue, but also leads to significant increase of the myocardial wall thickness very close to that of normal myocardium upon one single injection with complete degradation within 28 days. Notably, the hydrogel covalently conjugated with a tailored peptide sequence of GGR-KLT and encapsulated with bone mesenchymal stem cells (BMSCs) was further used for in situ injection in a rat MI model, which exhibited (i) efficient inhibition of excessive matrix degradation dependent on early MMP-2 expression, (ii) triggered on-demand release of KLT for at least 14 days and significant promotion of angiogenesis, and (iii) synergistic BMSCs considerably enhanced myocardial regeneration within 28 days. Taken together, the dual crosslinking conductive hydrogel-mediated synergistic peptide and cell therapy provides comprehensive recovery and regeneration of the structure and function of the injured myocardium, thus demonstrating great potential for clinical translations.

The Role of Ferroptosis in Adverse Left Ventricular Remodeling Following Acute Myocardial Infarction

Ferroptosis is an iron-dependent form of regulated cell death and is distinct from other conventional forms of regulated cell death. It is often characterized by the dysfunction of the antioxidant selenoprotein glutathione peroxidase 4 (GPX4) antioxidant system. This loss of antioxidant capacity leads to the peroxidation of lipids and subsequent compromised plasma membrane structure. Disruption of the GPX4 antioxidant system has been associated with various conditions such as cardiomyopathy and ischemia-reperfusion (I/R) injury. GPX4 regulates lipid peroxidation, and chemical or genetic inhibition of GPX4 leads to reduced cardiac function. Iron chelators or antioxidants can be used for inhibiting ferroptosis, which restores functionality in in vivo and ex vivo experiments and confers overall cardioprotective effects against I/R injury. Moreover, suppression of ferroptosis also suppresses inflammation and limits the extent of left ventricle remodeling after I/R injury. Future research is necessary to understand the role of ferroptosis following an ischemic incident and can lead to the discovery of more potential therapeutics that prevent ferroptosis in the heart.

Antioxidant Cardioprotection against Reperfusion Injury: Potential Therapeutic Roles of Resveratrol and Quercetin

Ischemia-reperfusion myocardial damage is a paradoxical tissue injury occurring during percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) patients. Although this damage could account for up to 50% of the final infarct size, there has been no available pharmacological treatment until now. Oxidative stress contributes to the underlying production mechanism, exerting the most marked injury during the early onset of reperfusion. So far, antioxidants have been shown to protect the AMI patients undergoing PCI to mitigate these detrimental effects; however, no clinical trials to date have shown any significant infarct size reduction. Therefore, it is worthwhile to consider multitarget antioxidant therapies targeting multifactorial AMI. Indeed, this clinical setting involves injurious effects derived from oxygen deprivation, intracellular pH changes and increased concentration of cytosolic Ca²⁺ and reactive oxygen species, among others. Thus, we will review a brief overview of the pathological cascades involved in ischemia-reperfusion injury and the potential therapeutic effects based on preclinical studies involving a combination of antioxidants, with particular reference to resveratrol and quercetin, which could contribute to cardioprotection against ischemia-reperfusion injury in myocardial tissue. We will also highlight the upcoming perspectives of these antioxidants for designing future studies.

The Role of Angiogenesis and Arteriogenesisin Myocardial Infarction and Coronary Revascularization

Surgical myocardial revascularization is associated with long-term survival benefit in patients with multivessel coronary artery disease. However, the exact biological mechanisms underlying the clinical benefits of myocardial revascularization have not been elucidated yet. Angiogenesis and arteriogenesis biologically leading to vascular collateralization are considered one of the endogenous mechanisms to preserve myocardial viability during ischemia, and the presence of coronary collateralization has been regarded as one of the predictors of long-term survival in patients with coronary artery disease (CAD). Some experimental studies and indirect clinical evidence on chronic CAD confirmed an angiogenetic response induced by myocardial revascularization and suggested that revascularization procedures could constitute an angiogenetic trigger per se. In this review, the clinical and basic science evidence regarding arteriogenesis and angiogenesis in both CAD and coronary revascularization is analyzed with the aim to better elucidate their significance in the clinical arena and potential therapeutic use.

Açai supplementation (Euterpe oleracea Mart.) attenuates cardiac remodeling after myocardial infarction in rats through different mechanistic pathways

Myocardial infarction has a high mortality rate worldwide. Therefore, clinical intervention in cardiac remodeling after myocardial infarction is essential. Açai pulp is a natural product and has been considered a functional food because of its antioxidant/anti-inflammatory properties. The aim of the present study was to analyze the effect of açai pulp supplementation on cardiac remodeling after myocardial infarction in rats. After 7 days of surgery, male Wistar rats were assigned to six groups: sham animals fed standard chow (SA0, n = 14), fed standard chow with 2% açai pulp (SA2, n = 12) and fed standard chow with 5% açai pulp (SA5, n = 14), infarcted animals fed standard chow (IA0, n = 12), fed standard chow with 2% açai pulp (IA2, n = 12), and fed standard chow with 5% açai pulp (IA5, n = 12). After 3 months of supplementation, echocardiography and euthanasia were performed. Açai pulp supplementation, after myocardial infarction, improved energy metabolism, attenuated oxidative stress (lower concentration of malondialdehyde, P = 0.023; dose-dependent effect), modulated the inflammatory process (lower concentration of interleukin-10, P<0.001; dose-dependent effect) and decreased the deposit of collagen (lower percentage of interstitial collagen fraction, P<0.001; dose-dependent effect). In conclusion, açai pulp supplementation attenuated cardiac remodeling after myocardial infarction in rats. Also, different doses of açai pulp supplementation have dose-dependent effects on cardiac remodeling.

Anti-inflammatory and modulatory effects of steroidal saponins and sapogenins on cytokines: A review of pre-clinical research

BACKGROUND

Saponins are glycosides which, after acid hydrolysis, liberate sugar(s) and an aglycone (sapogenin) which can be triterpenoid or steroidal in nature. Steroidal saponins and sapogenins have attracted significant attention as important natural anti-inflammatory compounds capable of acting on the activity of several inflammatory cytokines in various inflammatory models.

PURPOSE

The aim of this review is to collect preclinical in vivo studies on the anti-inflammatory activity of steroidal saponins through the modulation of inflammatory cytokines.

STUDY DESIGN AND METHODS

This review was carried out through a specialized search in three databases, that were accessed between September and October, 2021, and the publication period of the articles was not limited. Information about the name of the steroidal saponins, the animals used, the dose and route of administration, the model of pain or inflammation used, the tissue and experimental method used in the measurement of the cytokines, and the results observed on the levels of cytokines was retrieved.

RESULTS

Forty-five (45) articles met the inclusion criteria, involving the saponins cantalasaponin-1, α-chaconine, dioscin, DT-13, lycoperoside H, protodioscin, α-solanine, timosaponin AIII and BII, trillin, and the sapogenins diosgenin, hecogenin, and ruscogenin. The surveys were carried out in seven different countries and only articles between 2007 and 2021 were found. The studies included in the review showed that the saponins and sapogenins were anti-inflammatory, antinociceptive and antioxidant and they modulate inflammatory cytokines mainly through the Nf-κB, TLR4 and MAPKs pathways.

CONCLUSION

Steroidal saponins and sapogenins are promising compounds in handling of pain and inflammation for the development of natural product-derived drugs. However, it is necessary to increase the methodological quality of preclinical studies, mainly blinding and sample size calculation.

Role of NLRP3 Inflammasome in Myocardial Ischemia-Reperfusion Injury and Ventricular Remodeling

Reperfusion therapy is the optimal therapy for acute myocardial infarction (AMI), but acute inflammatory injury and chronic heart failure (HF) after myocardial ischemia and reperfusion (MI/R) remain the leading cause of death after AMI. Pyroptosis, a newly discovered form of cell death, has been proven to play a significant role in the acute reperfusion process and the subsequent chronic process of ventricular remodeling. Current research shows that multiple stimuli activate the pyroptotic signaling pathway and contribute to cell death and nonbacterial inflammation after MI/R. These stimuli promote the assembly of the nucleotide-binding and oligomerization-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by activating NLRP3. The mature NLRP3 inflammasome cleaves procaspase-1 to active caspase-1, which leads to mature processing of interleukin (IL)-18, IL-1β, and gasdermin D (GSDMD) protein. That eventually results in cell lysis and generation of nonbacterial inflammation. The present review summarizes the mechanism of NLRP3 inflammasome activation after MI/R and discusses the role that NLRP3-mediated pyroptosis plays in the pathophysiology of MI/R injury and ventricular remodeling. We also discuss potential mechanisms and targeted therapy for which there is evidence supporting treatment of ischemic heart disease.

Inflammation in the Pathogenesis of Arrhythmogenic Cardiomyopathy: Secondary Event or Active Driver?

Arrhythmogenic cardiomyopathy (ACM) is a rare inherited cardiac disease characterized by arrhythmia and progressive fibro-fatty replacement of the myocardium, which leads to heart failure and sudden cardiac death. Inflammation contributes to disease progression, and it is characterized by inflammatory cell infiltrates in the damaged myocardium and inflammatory mediators in the blood of ACM patients. However, the molecular basis of inflammatory process in ACM remains under investigated and it is unclear whether inflammation is a primary event leading to arrhythmia and myocardial damage or it is a secondary response triggered by cardiomyocyte death. Here, we provide an overview of the proposed players and triggers involved in inflammation in ACM, focusing on those studied using in vivo and in vitro models. Deepening current knowledge of inflammation-related mechanisms in ACM could help identifying novel therapeutic perspectives, such as anti-inflammatory therapy.

miR-210 Regulates Apoptotic Cell Death during Cellular Hypoxia and Reoxygenation in a Diametrically Opposite Manner

Apoptotic cell death of cardiomyocytes is a characteristic hallmark of ischemia-reperfusion (I/R) injury. The master hypoxamiR, microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxic stress. However, to date, no consensus has emerged with regards to the polarity of the miR-210-elicited cellular response, as miR-210 has been shown to exacerbate as well as attenuate hypoxia-driven apoptotic cell death. Herein, in AC-16 cardiomyocytes subjected to hypoxia-reoxygenation (H-R) stress, we unravel novel facets of miR-210 biology and resolve the biological response mediated by miR-210 into the hypoxia and reoxygenation temporal components. Using transient overexpression and decoy/inhibition vectors to modulate miR-210 expression, we elucidated a Janus role miR-210 in the cellular response to H-R stress, wherein miR-210 mitigated the hypoxia-induced apoptotic cell death but exacerbated apoptotic cell death during cellular reoxygenation. We further delineated the underlying cellular mechanisms that confer this diametrically opposite effect of miR-210 on apoptotic cell death. Our exhaustive biochemical assays cogently demonstrate that miR-210 attenuates the hypoxia-driven intrinsic apoptosis pathway, while significantly augmenting the reoxygenation-induced caspase-8-mediated extrinsic apoptosis pathway. Our study is the first to unveil this Janus role of miR-210 and to substantiate the cellular mechanisms that underlie this functional duality.

Tissue distribution and transcriptional regulation of CCN5 in the heart after myocardial infarction

CCN5 is a divergent member of the cellular communication network factor (CCN) family in that it lacks the carboxyl terminal cystine knot domain common to the other CCN family members. CCN5 has been reported to antagonize the profibrotic actions of CCN2 and to inhibit myocardial collagen deposition and fibrosis in chronic pressure overload of the heart. However, what mechanisms that regulate CCN5 activity in the heart remain unknown. Recombinant, replication defective adenovirus encoding firefly luciferase under control of the human CCN5 promoter was prepared and used to investigate what mechanisms regulate CCN5 transcription in relevant cells. Tissue distribution of CCN5 in hearts from healthy mice and from mice subjected to myocardial infarction was investigated. Contrary to the profibrotic immediate early gene CCN2, we find that CCN5 is induced in the late proliferation and maturation phases of scar healing. CCN5 was identified principally in endothelial cells, fibroblasts, smooth muscle cells, and macrophages. Our data show that CCN5 gene transcription and protein levels are induced by catecholamines via β₂-adrenergic receptors. Myocardial induction of CCN5 was further confirmed in isoproterenol-infused mice. We also find that CCN5 transcription is repressed by TNF-α, an inflammatory mediator highly elevated in early phases of wound healing following myocardial infarction. In conclusion, CCN5 predominates in endothelial cells, fibroblasts, and macrophages of the differentiating scar tissue and its transcription is conversely regulated by β₂-adrenergic agonists and TNF-α.

Exosomes derived from miR-129-5p modified bone marrow mesenchymal stem cells represses ventricular remolding of mice with myocardial infarction

Myocardial infraction (MI) is a severe disease with great mortality. Mesenchymal stem cells-derived exosomes display protection against MI. MicroRNA-129-5p was reported to exert anti-inflammation activity by targeting high mobility group box 1 (HMGB1). In the present study, the effects of MSCs derived exosomes overexpressing miR-129-5p on MI were evaluated. Bone marrow mesenchymal stem cells (BMSCs) were transfected with miR-129-5p for exosomes isolation. Myocardial infraction mice model was established and administrated exosomes overexpressing miR-129-5p. The cardiac function, expression of HMGB1, inflammatory cytokines, apoptosis and fibrosis in heart tissues were measured. miR-129-5p inhibited HMGB1 expression in BMSCs. Myocardial infraction mice treated with exosomes overexpressing miR-129-5p had enhanced cardiac function and decreased expression of HMGB1 and production of inflammatory cytokines. Exosomes overexpressing miR-129-5p further prevented apoptosis and fibrosis. Exosome-mediated transfer of miR-129-5p suppressed inflammation in MI mice by targeting HMGB1.

Níveis mais Baixos de Fetuína-A Sérica estão Associados a um Maior Risco de Mortalidade em Dez Anos em Pacientes com Infarto do Miocárdio por Supradesnivelamento do Segmento ST

Fundamento

A fetuína-A é um fator anti-inflamatório e anticalcificação envolvido no curso da doença arterial coronariana (DAC). Em alinhamento com essas funções, investigou-se a fetuína-A como marcador de risco cardiovascular em vários estudos. Porém, a associação entre a fetuína-A e o prognóstico dos pacientes com DAC ainda é controversa.

Objetivos

O presente estudo foi conduzido para identificar a associação entre o nível de fetuína-A sérica e doença cardiovascular (DCV) de longo prazo e a mortalidade global por infarto do agudo do miocárdio por supradesnivelamento do segmento ST (STEMI).

Métodos

Foram cadastrados no estudo cento e oitenta pacientes consecutivos com STEMI. A população do estudo foi dividida em subgrupos (mais baixo, ≤288 µg/ml; e mais alto, >288 µg/ml) de acordo com a mediana do nível de fetuína-A. Dados de acompanhamento clínico foram obtidos por contato telefônico anual com pacientes ou familiares. As causas das mortes também foram confirmadas pelo banco de dados de saúde nacional. P-valores bilaterais <0,05 foram considerados estatisticamente significativos.

Resultados

Durante um acompanhamento médio de 10 anos, foram registradas 71 mortes, das quais 62 foram devidas a DCV. Identificou-se um índice de mortalidade global e por DCV significativamente mais alto no grupo com nível de fetuína-A mais baixo que no grupo com nível de fetuína-A mais alto (44% versus 24%, p= 0,005; 48% versus 31%, p= 0,022, respectivamente). Nas análises de risco proporcionais por regressão de Cox, detectou-se que a fetuína-A era um preditor independente de mortalidade global e por DCV.

Conclusões

A baixa concentração de fetuína-A está associada ao prognóstico de longo prazo ruim pós-STEMI, independentemente de fatores de risco cardiovascular tradicionais. Nossos achados fortaleceram estudos prévios demonstrando consistentemente o papel determinante dos mediadores anti-inflamatórios em síndromes coronárias agudas.

Bioengineering Methods in MicroRNA-Mediated Direct Reprogramming of Fibroblasts Into Cardiomyocytes

Ischemic heart disease is the major cause of mortality worldwide. Despite the most recent pharmacological progresses, cardiac regeneration is yet not possible, and heart transplantation is the only therapeutic option for end-stage heart failure. Traditional cardiac regenerative medicine approaches, such as cell therapies and tissue engineering, have failed in the obtainment of human functional cardiac tissue, mainly due to unavailability of high quantities of autologous functional cardiomyocytes (CMs), low grafting efficiency, and/or arrhythmic events. Direct reprogramming (DR) of fibroblasts into induced CMs (iCMs) has emerged as a new promising approach for myocardial regeneration by in situ transdifferentiation or providing additional CM source for cell therapy. Among available DR methods, non-viral transfection with microRNAs (miRcombo: miR-1, miR-133, miR-208, and miR-499) appears promising for future clinical translation. MiRcombo transfection of fibroblasts could be significantly improved by the development of safe nanocarriers, efficiently delivering their cargo to target cells at the required stoichiometric ratio and overall dose in due times. Newly designed in vitro 3D culture microenvironments, providing biomimetic biophysical and biochemical stimuli to miRcombo-transfected cells, significantly increase the yield of fibroblast transdifferentiation into iCMs, enhancing CM gene expression. Epigenetic regulation of gene expression programs, critical to cell lineage commitment, can also be promoted by the administration of specific anti-inflammatory and anti-fibrotic soluble factors, helping in suppressing fibroblast signature. The aim of this mini-review is to introduce the readers to a relatively unknown field of cardiac research integrating bioengineering tools as relevant for the progress of miRNA-mediated cardiac DR.

Hollow CeO2 with ROS-Scavenging Activity to Alleviate Colitis in Mice

Introduction

Excessive production of reactive oxygen species (ROS) to induce high oxidative stress is one of the main causes of colitis; thus, it has been regarded as a therapeutic target for colitis treatment. And the nanomaterial-based therapeutic strategies are effective against colitis. However, the previous elaborately designed materials exhibit limited application due to the uncertain biocompatibility and complicated manufacturing processes.

Methods

In this study, the highly monodisperse hollow CeO₂ nanoparticles (H-CeO₂) with uniform morphology were obtained by in situ growing CeO₂ on solid silica nanoparticles and subsequently removing the silica core. The H-CeO₂ was further modified with PEG, which owned excellent biological stability and biocompatibility. The experimental model of colitis induced by dextran sulfate sodium (DSS) was used to investigate the anti-inflammatory effect of H-CeO₂-PEG.

Results

The H-CeO₂-PEG showed good ROS scavenging efficacy and decreased the levels of proinflammatory cytokines (IL-6, IL-1β, IL-18, and TNF-α) in DSS-induced colitis mice. Furthermore, H-CeO₂-PEG inhibited the activation of the MAPK signalling pathway to alleviate colitis.

Conclusion

This study reveals the therapeutic effects of CeO₂-based nanomedicine toward colitis and elucidates the specific signalling pathway involved, which provides potential alternative therapeutic options for patients with inflammation tissue.

Left Ventricular Hypertrophy in Diabetic Cardiomyopathy: A Target for Intervention

Heart failure is an important manifestation of diabetic heart disease. Before the development of symptomatic heart failure, as much as 50% of patients with type 2 diabetes mellitus (T2DM) develop asymptomatic left ventricular dysfunction including left ventricular hypertrophy (LVH). Left ventricular hypertrophy (LVH) is highly prevalent in patients with T2DM and is a strong predictor of adverse cardiovascular outcomes including heart failure. Importantly regression of LVH with antihypertensive treatment especially renin angiotensin system blockers reduces cardiovascular morbidity and mortality. However, this approach is only partially effective since LVH persists in 20% of patients with hypertension who attain target blood pressure, implicating the role of other potential mechanisms in the development of LVH. Moreover, the pathophysiology of LVH in T2DM remains unclear and is not fully explained by the hyperglycemia-associated cellular alterations. There is a growing body of evidence that supports the role of inflammation, oxidative stress, AMP-activated kinase (AMPK) and insulin resistance in mediating the development of LVH. The recognition of asymptomatic LVH may offer an opportune target for intervention with cardio-protective therapy in these at-risk patients. In this article, we provide a review of some of the key clinical studies that evaluated the effects of allopurinol, SGLT2 inhibitor and metformin in regressing LVH in patients with and without T2DM.

Inflammatory Biomarkers and Endothelial Alteration in Patients with Heart Failure and Acute Coronary Syndromes

Introduction: Systemic inflammation plays a key role in the pathophysiology of acute coronary syndrome (ACS), having a direct effect in promoting the progression and rupture of vulnerable coronary plaques. The aim of this study was to investigate the association between inflammatory biomarkers and the type of ACS (ST-elevation myocardial infarction – STEMI, non-ST-elevation myocardial infarction – NSTEMI, or unstable angina – UA) in patients with confirmed heart failure.

Material and Methods: This study included a total of 266 patients admitted to the Clinical Department of Cardiology of the County Emergency Clinical Hospital of Târgu Mureș – Cardiac Intensive Care Unit (CICU) for ACS of various types (UA, NSTEMI or STEMI) between January 1, 2017 and December 31, 2020, in whom the diagnosis of heart failure was established based on clinical and paraclinical data. From the total number of patients, 36 were hospitalized for UA and 230 for MI, of which 165 were STEMI and 65 were NSTEMI.

Results: Only hs-CRP and IL-6 were significantly higher in MI compared to UA. Mean hs-CRP was 4.9 ± 4.5 mg/mL in patients with UA vs. 20.4 ± 42.2 mg/mL in patients with MI (p = 0.001), and mean IL-6 was 7.2 ± 13.8 pg/mL in UA vs. 31.6 ± 129.2 pg/mL in MI (p <0.0001). ICAM seems to have had a greater discriminating power between STEMI and other types of ACS in those with heart failure, having a value more than double in those with STEMI (216.1 ± 149.6 ng/mL vs. 448.2 ± 754.4 ng/mL, p <0.0001).

Conclusions: In patients with heart failure, the increase of inflammatory biomarkers such as hs-CRP is associated with the development of an acute myocardial infarction but not with its type. Adhesion molecules, especially ICAM, are elevated in patients with STEMI compared to other types of ACS, indicating a potential role of endothelial alteration in the development of an ACS when it adds to systemic inflammation linked to heart failure.