Inhibition of NF-κB improves left ventricular remodeling and cardiac dysfunction after myocardial infarction

Melatonin effects on oxidative stress and on TLR4/NF-kβ inflammatory pathway in the right ventricle of rats with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterised by an increase in mean pulmonary arterial pressure and a compromised the right ventricle (RV), together with progression to heart failure and premature death. Studies have evaluated the role of melatonin as a promising therapeutic strategy for PAH. The objective of this study was to evaluate melatonin's effects on oxidative stress and on the TLR4/NF-kβ inflammatory pathway in the RV of rats with PAH. Male Wistar rats were divided into the following groups: control, monocrotaline (MCT), and monocrotaline plus melatonin groups. These two last groups received one intraperitoneal injection of MCT (60 mg/kg) on the first day of experimental protocol. The monocrotaline plus melatonin group received 10 mg/kg/day of melatonin by gavage for 21 days. Echocardiographic analysis was performed, and the RV was collected for morphometric analysis oxidative stress and molecular evaluations. The main findings of the present study were that melatonin administration attenuated the reduction in RV function that was induced by monocrotaline, as assessed by TAPSE. In addition, melatonin prevented RV diastolic area reduction caused by PAH. Furthermore, animals treated with melatonin did not show an increase in ROS levels or in NF-kβ expression. In addition, the monocrotaline plus melatonin group showed a reduction in TLR4 expression when compared with control and monocrotaline groups. To our knowledge, this is the first study demonstrating a positive effect of melatonin on the TLR4/NF-kβ pathway in the RV of rats with PAH. In this sense, this study makes it possible to think of melatonin as a possible ally in mitigating RV alterations caused by PAH.

Melatonin improves nitric oxide bioavailability in isoproterenol induced myocardial injury

Isoproterenol administration is associated with cardiac inflammation and decreased NO availability. Melatonin has been reported to have cardioprotective effect. The aim of this study was to investigate the effect of melatonin on NO bioavailability and inflammation in myocardial injury induced by isoproterenol. Isoproterenol was administrated in male Wistar rats for 7 days to induce cardiac injury. The animals were divided into 3 groups: Control, Isoproterenol, Isoproterenol + Melatonin. Animals received melatonin for 7 days. Echocardiographic analysis was performed and the hearts were collected for molecular analysis. Animals that received isoproterenol demonstrated a reduction in left ventricle systolic and diastolic diameter, indicating the presence of concentric hypertrophy. Melatonin was able to attenuate this alteration. Melatonin also improved NO bioavailability and decreased NF-κβ, TNFα and IL-1β expression. In conclusion, melatonin exhibited a cardioprotective effect which was associated with improving NO bioavailability and decreasing the pro-inflammatory proteins.

Growth/differentiation factor 15 (GDF15) expression in the heart after myocardial infarction and cardioprotective effect of pre-ischemic rGDF15 administration

Growth/differentiation factor-15 (GDF15) is considered an unfavourable prognostic biomarker for cardiovascular disease in clinical data, while experimental studies suggest it has cardioprotective potential. This study focuses on the direct cardiac effects of GDF15 during ischemia-reperfusion injury in Wistar male rats, employing concentrations relevant to patients at high cardiovascular risk. Initially, we examined circulating levels and heart tissue expression of GDF15 in rats subjected to ischemia-reperfusion and sham operations in vivo. We then evaluated the cardiac effects of GDF15 both in vivo and ex vivo, administering recombinant GDF15 either before 30 min of ischemia (preconditioning) or at the onset of reperfusion (postconditioning). We compared infarct size and cardiac contractile recovery between control and rGDF15-treated rats. Contrary to our expectations, ischemia-reperfusion did not increase GDF15 plasma levels compared to sham-operated rats. However, cardiac protein and mRNA expression increased in the infarcted zone of the ischemic heart after 24 h of reperfusion. Notably, preconditioning with rGDF15 had a cardioprotective effect, reducing infarct size both in vivo (65 ± 5% in control vs. 42 ± 6% in rGDF15 groups) and ex vivo (60 ± 4% in control vs. 45 ± 4% in rGDF15 groups), while enhancing cardiac contractile recovery ex vivo. However, postconditioning with rGDF15 did not alter infarct size or the recovery of contractile parameters in vivo or ex vivo. These novel findings reveal that the short-term exogenous administration of rGDF15 before ischemia, at physiologically relevant levels, protects the heart against ischemia-reperfusion injury in both in vivo and ex vivo settings. The ex vivo results indicate that rGDF15 operates independently of the inflammatory, endocrine and nervous systems, suggesting direct and potent cardioprotective properties against ischemia-reperfusion injury.

Noninvasive and Invasive Study of the Pumping Function of Rat Heart in Myocardial Infarction

The cardiohemodynamics was studied 2 and 4 weeks after myocardial infarction modeling in Wistar rats. We compared the data obtained by echocardiography (echoCG) and catheterization of the left ventricle. The myocardial infarction was modeled by ligation of the left anterior descending coronary artery. EchoCG and the left ventricle catheterization were performed before and after myocardial infarction modeling. Similar results were obtained by both methods, namely the left ventricle dilatation, bradycardia, a reduced ejection fraction and delayed relaxation. According to echoCG, the end-diastolic left ventricle volume increased by 2 times, and initial diastolic left ventricle volume - by more than 5 times. The left ventricle catheterization showed lower rise, by 32 and 69%, respectively. The overestimated volume of the left ventricle in myocardial infarction according to echoCG data in comparison with catheterization can be explained by changes in the geometry of the ventricle (bulging of a part of the ventricular wall).

The Role of Arterial Elasticity in Determining the Degree of Chronic Heart Failure in Myocardial Infarction

Aim      To study the left ventricular (LV) contractile and pumping function during the recovery phase following ligation of the anterior descending coronary artery (CA).Material and methods  Cardiodynamic parameters were studied in Wistar rats 2-4 weeks after experimental myocardial infarction (MI). MI was induced by ligation of the anterior descending CA under zoletil anesthesia. LV catheterization was performed with a standard FTH-1912B-8018 PV catheter inserted into the LV through the right carotid artery.Results After the induction of MI, the mortality rate of animals was 50%. Survived animals developed significant LV dilatation and a decrease in ejection fraction (EF) by an average of 31%. However, major indexes of the pumping function, including minute volume, heart work, and maximum ejection velocity, were within a normal range whereas the maximum filling velocity was almost doubled. Approximately 50% of hearts with dilated LV had normal EF, delayed relaxation, and increased LV diastolic pressure, which qualified this group as a diastolic dysfunction group. The systolic dysfunction group with EF less than 50% of normal had similar values of myocardial contractility and relaxation but differed from the diastolic dysfunction group in more than 50% reduced maximum LV ejection velocity and 1.7 times increased elasticity of the arterial wall. A close inverse correlation was found between these values (r= -0.91).Conclusion      The study results showed that, with a similar myocardial contractile function, the cardiac pumping function is determined by the elasticity of the aortic wall. Therefore, restriction of reactive fibrosis during MI is an important task of modern cardiology.

Water channel aquaporin 4 is required for T cell receptor mediated lymphocyte activation

Aquaporins are a family of ubiquitously expressed transmembrane water channels implicated in a broad range of physiological functions. We have previously reported that aquaporin 4 (AQP4) is expressed on T cells and that treatment with a small molecule AQP4 inhibitor significantly delays T cell mediated heart allograft rejection. Using either genetic deletion or small molecule inhibitor, we show that AQP4 supports T cell receptor mediated activation of both mouse and human T cells. Intact AQP4 is required for optimal T cell receptor (TCR)-related signaling events, including nuclear translocation of transcription factors and phosphorylation of proximal TCR signaling molecules. AQP4 deficiency or inhibition impairs actin cytoskeleton rearrangements following TCR crosslinking, causing inferior TCR polarization and a loss of TCR signaling. Our findings reveal a novel function of AQP4 in T lymphocytes and identify AQP4 as a potential therapeutic target for preventing TCR-mediated T cell activation.

Systematic investigation of the multi-scale mechanisms of herbal medicine on treating ventricular remodeling: Theoretical and experimental studies

BACKGROUND

To explore the underlying molecule mechanism of herbal medicine in preventing ventricular remodeling (VR), we take a herbal formula that is clinically effective for preventing VR as an example, which composed of Pachyma hoelen Rumph, Atractylodes macrocephala Koidz., Cassia Twig and Licorice. Due to multi-components and multi-targets in herbal medicine, it is extremely difficult to systematically explain its mechanisms of action.

METHODS

An innovative systematic investigation framework which combines with pharmacokinetic screening, target fishing, network pharmacology, DeepDDI algorithm, computational chemistry, molecular thermodynamics, in vivo and in vitro experiments was performed for deciphering the underlying molecular mechanisms of herbal medicine for treating VR.

RESULTS

ADME screening and SysDT algorithm determined 75 potentially active compounds and 109 corresponding targets. Then, systematic analysis of networks reveals the crucial active ingredients and key targets in herbal medicine. Additionally, transcriptomic analysis identifies 33 key regulators during VR progression. Moreover, PPI network and biological function enrichment present four crucial signaling pathways, i.e. NF-κB and TNF, PI3K-AKT and C-type lectin receptor signaling pathways involved in VR. Besides, both molecular experiments at animal and cell levels reveal the beneficial effect of herbal medicine on preventing VR. Finally, MD simulations and binding free energy validate the reliability of drug-target interactions.

CONCLUSION

Our novelty is to build a systematic strategy which combines various theoretical methods combined with experimental approaches. This strategy provides a deep understanding for the study of molecular mechanisms of herbal medicine on treating diseases from systematic level, and offers a new idea for modern medicine to explore drug interventions for complex diseases as well.

Moderate-Intensity Exercise Maintains Redox Homeostasis for Cardiovascular Health

It is well known that exercise is beneficial for cardiovascular health. Oxidative stress is the common pathological basis of many cardiovascular diseases. The overproduction of free radicals, both reactive oxygen species and reactive nitrogen species, can lead to redox imbalance and exacerbate oxidative damage to the cardiovascular system. Maintaining redox homeostasis and enhancing anti-oxidative capacity are critical mechanisms by which exercise protects against cardiovascular diseases. Moderate-intensity exercise is an effective means to maintain cardiovascular redox homeostasis. Moderate-intensity exercise reduces the risk of cardiovascular disease by improving mitochondrial function and anti-oxidative capacity. It also attenuates adverse cardiac remodeling and enhances cardiac function. This paper reviews the primary mechanisms of moderate-intensity exercise-mediated redox homeostasis in the cardiovascular system. Exploring the role of exercise-mediated redox homeostasis in the cardiovascular system is of great significance to the prevention and treatment of cardiovascular diseases.

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.

Cytokine storm: behind the scenes of the collateral circulation after acute myocardial infarction

At least 17 million people die from acute myocardial infarction (AMI) every year, ranking it first among causes of death of human beings, and its incidence is gradually increasing. Typical characteristics of AMI include acute onset and poor prognosis. At present, there is no satisfactory treatment, but development of coronary collateral circulation (CCC) can be key to improving prognosis. Recent research indicates that the levels of cytokines, including those related to promoting inflammatory responses and angiogenesis, increase after the onset of AMI. In the early phase of AMI, cytokines play a vital role in inducing development of collateral circulation. However, when myocardial infarction is decompensated, cytokine secretion increases greatly, which may induce a cytokine storm and worsen prognosis. Cytokines can regulate the activation of a variety of signal pathways and form a complex network, which may promote or inhibit the establishment of collateral circulation. We searched for published articles in PubMed and Google Scholar, employing the keyword "acute myocardial infarction", "coronary collateral circulation" and "cytokine storm", to clarify the relationship between AMI and a cytokine storm, and how a cytokine storm affects the growth of collateral circulation after AMI, so as to explore treatment methods based on cytokine agents or inhibitors used to improve prognosis of AMI.

Phytochemicals from medicinal plants from African forests with potentials in rheumatoid arthritis management

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammation, pain, and cartilage and bone damage. There is currently no cure for RA. It is however managed using nonsteroidal anti-inflammatory drugs, corticosteroids and disease-modifying anti-rheumatic drugs, often with severe side effects. Hidden within Africa's lush vegetation are plants with diverse medicinal properties including anti-RA potentials. This paper reviews the scientific literature for medicinal plants, growing in Africa, with reported anti-RA activities and identifies the most abundant phytochemicals deserving research attention. A search of relevant published scientific literature, using the major search engines, such as Pubmed/Medline, Scopus, Google Scholar, etc. was conducted to identify medicinal plants, growing in Africa, with anti-RA potentials.

KEY FINDINGS

Twenty plants belonging to 17 families were identified. The plants are rich in phytochemicals, predominantly quercetin, rutin, catechin, kaempferol, etc., known to affect some pathways relevant in RA initiation and progression, and therefore useful in its management.

SUMMARY

Targeted research is needed to unlock the potentials of medicinal plants by developing easy-to-use technologies for preparing medicines from them. Research attention should focus on how best to exploit the major phytochemicals identified in this review for the development of anti-RA 'green pharmaceuticals'.

Nanoparticle-Delivered microRNA-153-3p Alleviates Myocardial Infarction-Induced Myocardial Injury in a Rat Model

Although microRNA-153-3p (miR-153-3p) has been demonstrated to confer protective roles in ischemia/reperfusion injury, its potential role in myocardial infarction (MI) remains undefined. Small-molecule modifiers and nanoparticles loaded with microRNAs (miRNAs) have emerged as potential therapeutic reagents for MI treatment. In this study, we prepared liposome nanoparticles, hyaluronic acid (HA)-cationic liposomes (CLPs) complex, for the delivery of miR-153-3p and delineated the mechanistic actions of miR-153-3p modified by nHA-CLPs in MI-induced injury. Our data suggested that nHA-CLPs-loaded miR-153-3p protected cardiomyocytes against MI-induced cardiomyocyte apoptosis and myocardial injury. miR-153-3p was bioinformatically predicted and experimentally verified to bind to Krüppel-like factor 5 (KLF5) 3'UTR and negatively regulate its expression. Hypoxia was adopted to stimulate MI-induced injury to cardiomyocytes in vitro, in which miR-153-3p presented anti-apoptotic potential. However, restoration of KLF5 reversed this anti-apoptotic effect of miR-153-3p. Furthermore, KLF5 was demonstrated to be an activator of the NF-κB pathway. KLF5 enhanced cardiomyocyte apoptosis and inflammation under hypoxic conditions through NF-κB pathway activation, while nHA-CLPs-loaded miR-153-3p suppressed inflammation by blocking the NF-κB pathway. Collectively, our findings suggested the cardioprotective role of miR-153-3p against MI and the successful delivery of miR-153-3p by nHA-CLPs. The identification of KLF5-mediated activation of NF-κB pathway as an apoptotic and inflammatory mechanism aids in better understanding of the biology of MI and development of novel therapeutic strategies for MI.

Synthetic Pyridoindole and Rutin Affect Upregulation of Endothelial Nitric Oxide Synthase and Heart Function in Rats Fed a High-Fat-Fructose Diet

Metabolic syndrome (MetS) belongs to the serious health complications expanding in cardiovascular diseases, obesity, insulin resistance, and hyperglycemia. In this study, hypertriacylglycerolemic rats fed a high-fat-fructose diet (HFFD) were used as an experimental model of MetS to explore the effect of tested compounds. Effects of a new prospective pyridoindole derivative coded SMe1EC2 and the natural polyphenol rutin were tested. Endothelial nitric oxide synthase (NOS3) and nuclear factor kappa B (NF-?B) expression were assessed in the left ventricle immunohistochemically and left ventricle activity was monitored in isolated perfused rat hearts. NOS3 activity in the left ventricle decreased markedly as a result of a HFFD. NOS3 expression was upregulated by both substances. NF-?B expression was increased in the MetS group in comparison to control rats and the expression further increased in the SMe1EC2 treatment. This compound significantly improved the coronary flow in comparison to the control group during reperfusion of the heart followed after ischemia. Further, it tended to increase left ventricular systolic pressure, heart product, rate of maximal contraction and relaxation, and coronary flow during baseline assessment. Moreover, the compound SMe1EC2 decreased the sensitivity of hearts to electrically induced ventricular fibrillation. Contrary to this rutin decreased coronary flow in reperfusion. Present results suggest that despite upregulation of NOS3 by both substances tested, pyridoindole SMe1EC2 rather than rutin could be suitable in treatment strategies of cardiovascular disorders in MetS-like conditions.

Reduced Cell Excitability of Cardiac Postganglionic Parasympathetic Neurons Correlates With Myocardial Infarction-Induced Fatal Ventricular Arrhythmias in Type 2 Diabetes Mellitus

Objective

Withdrawal of cardiac vagal activity is considered as one of the important triggers for acute myocardial infarction (MI)-induced ventricular arrhythmias in type 2 diabetes mellitus (T2DM). Our previous study demonstrated that cell excitability of cardiac parasympathetic postganglionic (CPP) neurons was reduced in T2DM rats. This study investigated whether cell excitability of CPP neurons is associated with cardiac vagal activity and MI-induced ventricular arrhythmias in T2DM rats.

Methods

Rat T2DM was induced by a high-fat diet plus streptozotocin injection. MI-evoked ventricular arrhythmia was achieved by surgical ligation of the left anterior descending coronary artery. Twenty-four-hour, continuous ECG recording was used to quantify ventricular arrhythmic events and heart rate variability (HRV) in conscious rats. The power spectral analysis of HRV was used to evaluate autonomic function. Cell excitability of CPP neurons was measured by the whole-cell patch-clamp technique.

Results

Twenty-four-hour ECG data demonstrated that MI-evoked fatal ventricular arrhythmias are more severe in T2DM rats than that in sham rats. In addition, the Kaplan-Meier analysis demonstrated that the survival rate over 2 weeks after MI is significantly lower in T2DM rats (15% in T2DM+MI) compared to sham rats (75% in sham+MI). The susceptibility to ventricular tachyarrhythmia elicited by programmed electrical stimulation was higher in anesthetized T2DM+MI rats than that in rats with MI or T2DM alone (7.0 ± 0.58 in T2DM+MI group vs. 3.5 ± 0.76 in sham+MI). Moreover, as an index for vagal control of ventricular function, changes of left ventricular systolic pressure (LVSP) and the maximum rate of increase of left ventricular pressure (LV dP/dt_max) in response to vagal efferent nerve stimulation were blunted in T2DM rats. Furthermore, T2DM increased heterogeneity of ventricular electrical activities and reduced cardiac parasympathetic activity and cell excitability of CPP neurons (current threshold-inducing action potentials being 62 ± 3.3 pA in T2DM rats without MI vs. 27 ± 1.9 pA in sham rats without MI). However, MI did not alter vagal control of the ventricular function and CPP neuronal excitability, although it also induced cardiac autonomic dysfunction and enhanced heterogeneity of ventricular electrical activities.

Conclusion

The reduction of CPP neuron excitability is involved in decreased cardiac vagal function, including cardiac parasympathetic activity and vagal control of ventricular function, which is associated with MI-induced high mortality and malignant ventricular arrhythmias in T2DM.

Role of IL-37- and IL-37-Treated Dendritic Cells in Acute Coronary Syndrome

As a chronic inflammatory disease, atherosclerosis is a leading cause of morbidity and mortality in most countries. Inflammation is responsible for plaque instability and the subsequent onset of acute coronary syndrome (ACS), which is one of the leading causes of hospitalization. Therefore, exploring the potential mechanism underlying ACS is of considerable concern, and searching for alternative therapeutic targets is very urgent. Interleukin-37 (IL-37) inhibits the production of proinflammatory chemokines and cytokines and acts as a natural inhibitor of innate and adaptive immunity. Interestingly, our previous study with murine models showed that IL-37 alleviated cardiac remodeling and myocardial ischemia/reperfusion injury. Of note, our clinical study revealed that IL-37 is elevated and plays a beneficial role in patients with ACS. Moreover, dendritic cells (DCs) orchestrate both immunity and tolerance, and tolerogenic DCs (tDCs) are characterized by more secretion of immunosuppressive cytokines. As expected, IL-37-treated DCs are tolerogenic. Hence, we speculate that IL-37- or IL-37-treated DCs is a novel therapeutic possibility for ACS, and the precise mechanism of IL-37 requires further study.

Quercetin prevents myocardial infarction adverse remodeling in rats by attenuating TGF-β1/Smad3 signaling: Different mechanisms of action

This study investigated the anti-remodeling and anti-fibrotic and effect of quercetin (QUR) in the remote non-infarcted of rats after myocardial infarction (MI). Rats were divided as control, control + QUR, MI, and MI + QUR. MI was introduced to the rats by ligating the eft anterior descending (LAD) coronary artery. All treatments were given for 30 days, daily. QUR persevered the LV hemodynamic parameters and prevented remote myocardium damage and fibrosis. Also, QUR supressed the generation of ROS, increased the nuclear levels of Nrf2, and enhanced SOD and GSH levels in the LVs of the control and MI model rats. It also reduced angiotensin II, nuclear level/activity of the nuclear factor NF-κβ p65, and protein expression of TGF-β1, α-SMA, and total/phospho-smad3 in the LVs of both groups. Concomitantly, QUR upregulated LV smad7 and BMP7. In conclusion, QUR prevents MI-induced LV remodeling by antioxidant, anti-inflammatory, and anti-fibroticα effects mediated by ROS scavenging, suppressing NF-κβ, and stimulating Nrf-2, Smad7, and BMP7.

UCHL1 inhibition attenuates cardiac fibrosis via modulation of nuclear factor-κB signaling in fibroblasts

The ubiquitin-proteasome system (UPS) plays an essential role in cellular homeostasis and myocardial function. Ubiquitin carboxy-terminal hydrolase 1 (UCHL1) is involved in cardiac remodeling, but its underlying mechanisms are largely unknown. Here, we observed that the UCHL1 was significantly up-regulated in angiotensin II-infused heart and primary cardiac fibroblast (CF). Systemic administration of the UCHL1 inhibitor LDN57444 significantly ameliorated cardiac fibrosis and improved cardiac function induced by angiotensin II. Also, LDN57444 inhibited CF cell proliferation as well as attenuated collagen I, and CTGF gene expression in the presence of Ang II. Mechanistically, UCHL1 promotes angiotensin II-induced fibrotic responses by way of activating nuclear factor kappa B (NF-κB) signaling. Moreover, suppression of the NF-κB pathway interfered with UCHL1 overexpression-mediated fibrotic responses. Besides, the chromatin immunoprecipitation assay demonstrated that NF-κB can bind to the UCHL1 promoter and trigger its transcription in cardiac fibroblasts. These findings suggest that UCHL1 positively regulates cardiac fibrosis by modulating NF-κB signaling pathway and identify UCHL1 could be a new treatment strategy for cardiac fibrosis.

miR-22 Host Gene Enhances Nuclear Factor-kappa B Activation to Aggravate Hypoxia-induced Injury in AC16 Cardiomyocytes

Myocardial infarction (MI) is a severe life-threatening disease caused by acute and persistent ischemia and hypoxia and eventually leads to heart failure and sudden death. Long noncoding RNAs (lncRNAs) play significant roles in the pathology, diagnosis, and development of various cardiovascular diseases, including MI. This study aimed to explore the effect and molecular mechanism of lncRNA miR-22 host gene (MIR22HG) on hypoxia-induced injury in AC16 cardiomyocytes. The expression of MIR22HG and miR-24 in hypoxia-treated AC16 cardiomyocytes was detected by quantitative real-time polymerase chain reaction. Cell viability, lactate dehydrogenase release, levels of aspartate aminotransferase (AST) and creatine kinase-MB (CK-MB), and apoptosis were detected by Cell Counting Kit-8, lactate dehydrogenase (LDH) release assay, commercial enzyme-linked immune sorbent assay kits, and flow cytometry analysis, respectively. The protein levels of nuclear factor-kappa B (NF-κB) p65 and cytoplasmic inhibitor of kappa B alpha (IκBα) and phosphorylated IκBα were detected by western blot. Results showed that hypoxia treatment decreased viability and increased MIR22HG expression in AC16 cardiomyocytes. MIR22HG overexpression aggravated hypoxia-induced viability reduction, leakage of myocardial injury markers LDH, AST, and CK-MB, and apoptosis in AC16 cardiomyocytes, while MIR22HG knockdown elicited the reverse effects. MIR22HG overexpression enhanced NF-κB activation in hypoxia-treated AC16 cardiomyocytes. Inhibition of NF-κB pathway impaired the effects of MIR22HG overexpression on hypoxia-induced injury in AC16 cardiomyocytes. Moreover, MIR22HG knockdown inhibited the NF-κB pathway by upregulating miR-24 in AC16 cardiomyocytes. Inhibition of miR-24 resisted the effects of MIR22HG silencing on hypoxia-induced injury in AC16 cardiomyocytes. In conclusion, MIR22HG overexpression aggravated hypoxia-induced injury in AC16 cardiomyocytes via enhancing NF-κB activation by targeting miR-24.

Innate Immune Nod1/RIP2 Signaling Is Essential for Cardiac Hypertrophy but Requires Mitochondrial Antiviral Signaling Protein for Signal Transductions and Energy Balance

BACKGROUND

Cardiac hypertrophy is a key biological response to injurious stresses such as pressure overload and, when excessive, can lead to heart failure. Innate immune activation by danger signals, through intracellular pattern recognition receptors such as nucleotide-binding oligomerization domain 1 (Nod1) and its adaptor receptor-interacting protein 2 (RIP2), might play a major role in cardiac remodeling and progression to heart failure. We hypothesize that Nod1/RIP2 are major contributors to cardiac hypertrophy, but may not be sufficient to fully express the phenotype alone.

METHODS

To elucidate the contribution of Nod1/RIP2 signaling to cardiac hypertrophy, we randomized Nod1^-/-, RIP2^-/-, or wild-type mice to transverse aortic constriction or sham operations. Cardiac hypertrophy, fibrosis, and cardiac function were examined in these mice.

RESULTS

Nod1 and RIP2 proteins were upregulated in the heart after transverse aortic constriction, and this was paralleled by increased expression of mitochondrial proteins, including mitochondrial antiviral signaling protein (MAVS). Nod1^-/- and RIP2^-/- mice subjected to transverse aortic constriction exhibited better survival, improved cardiac function, and decreased cardiac hypertrophy. Downstream signal transduction pathways that regulate inflammation and fibrosis, including NF (nuclear factor) κB and MAPK (mitogen-activated protein kinase)-GATA4/p300, were reduced in both Nod1^-/- and RIP2^-/- mice after transverse aortic constriction compared with wild-type mice. Coimmunoprecipitation of extracted cardiac proteins and confocal immunofluorescence microscopy showed that Nod1/RIP2 interaction was robust and that this complex also included MAVS as an essential component. Suppression of MAVS expression attenuated the complex formation, NF κB signaling, and myocyte hypertrophy. Interrogation of mitochondrial function compared in the presence or ablation of MAVS revealed that MAVS serves to suppress mitochondrial energy output and mediate fission/fusion related dynamic changes. The latter is possibly linked to mitophagy during cardiomyocytes stress, which may provide an intriguing link between innate immune activation and mitochondrial energy balance under stress or injury conditions.

CONCLUSIONS

We have identified that innate immune Nod1/RIP2 signaling is a major contributor to cardiac remodeling after stress. This process is critically joined by and regulated through the mitochondrial danger signal adapter MAVS. This novel complex coordinates remodeling, inflammatory response, and mitochondrial energy metabolism in stressed cardiomyocytes. Thus, Nod1/RIP2/MAVS signaling complex may represent an attractive new therapeutic approach toward heart failure.

Stem Cell Therapy for Chronic and Advanced Heart Failure

PURPOSE OF REVIEW

The purpose of this review is to discuss recent advances in the field of cell therapy in patients with heart failure with reduced ejection fraction (HFrEF) of ischemic (iCMP) and nonischemic (dCMP) etiology, heart failure with preserved ejection fraction (HFpEF), and in advanced heart failure patients undergoing mechanical circulatory support (LVAD).

RECENT FINDINGS

In HFrEF patients (iCMP and dCMP cohorts), autologous and/or allogeneic cell therapy was shown to improve myocardial performance, patients' functional capacity, and neurohumoral activation. In HFpEF patient population, the concept of cell therapy in novel and remains largely unexplored. However, initial data are very encouraging and suggest at least a similar benefit in improvements of myocardial performance (also diastolic function of the left ventricle), exercise capacity, and neurohumoral activation. Recently, cell therapy was explored in the sickest population of advanced heart failure patients undergoing LVAD support also showing a potential benefit in promoting myocardial reverse remodeling and recovery. In the past decade, several cell therapy-based clinical trials showed promising results in various chronic and advanced heart failure patient cohorts. Future cell treatment strategies should aim for more personalized therapeutic approaches by defining optimal stem cell type or their combination, dose, and delivery method for an individual patient adjusted for patient's age and stage/duration of heart failure.

Protective Effects of Polyphenols against Ischemia/Reperfusion Injury

Myocardial infarction (MI) is a leading cause of morbidity and mortality across the world. It manifests as an imbalance between blood demand and blood delivery in the myocardium, which leads to cardiac ischemia and myocardial necrosis. While it is not easy to identify the first pathogenic cause of MI, the consequences are characterized by ischemia, chronic inflammation, and tissue degeneration. A poor MI prognosis is associated with extensive cardiac remodeling. A loss of viable cardiomyocytes is replaced with fibrosis, which reduces heart contractility and heart function. Recent advances have given rise to the concept of natural polyphenols. These bioactive compounds have been studied for their pharmacological properties and have proven successful in the treatment of cardiovascular diseases. Studies have focused on their various bioactivities, such as their antioxidant and anti-inflammatory effects and free radical scavenging. In this review, we summarized the effects and benefits of polyphenols on the cardiovascular injury, particularly on the treatment of myocardial infarction in animal and human studies.

Research Progress of Oxidative Stress and MicroRNAs in the Prevention of Catheter-Related Thrombus Under Resistance Exercise

Central venous access devices (CVADs) have completely changed the care for patients who require long-term venous access. With the widespread use of CVADs, the incidence of catheter-related thrombus (CRT) has increased. Catheter-related thrombus is a common complication in patients who use CVADs and is mainly caused by endothelial injury, blood stasis, and hypercoagulability. In recent years, the correlations between oxidative stress (OS) and microRNA (miRNA) and CRT have become a hot topic in clinical research. When a catheter punctures the vessel wall, it causes OS damage to the vascular endothelial cells, leading to a series of CRT diseases. MicroRNAs can regulate the mechanism of thrombus and play an important role in the formation of anti-thrombus. Numerous studies have shown that resistance exercise can reduce the level of OS in vascular endothelial cells, inhibit vascular endothelial cell dysfunction, and maintain the stability of hemodynamics and biochemical state. In the current work, the recent studies on the effects of resistance exercise on OS and miRNA in vascular endothelial cells were reviewed.

Interleukin-38 alleviates cardiac remodelling after myocardial infarction

Excessive immune‐mediated inflammatory reaction plays a deleterious role in ventricular remodelling after myocardial infarction (MI). Interleukin (IL)‐38 is a newly characterized cytokine of the IL‐1 family and has been reported to exert a protective effect in some autoimmune diseases. However, its role in cardiac remodelling post‐MI remains unknown. In this study, we found that the expression of IL‐38 was increased in infarcted heart after MI induced in C57BL/6 mice by permanent ligation of the left anterior descending artery. In addition, our data showed that ventricular remodelling after MI was significantly ameliorated after recombinant IL‐38 injection in mice. This amelioration was demonstrated by better cardiac function, restricted inflammatory response, attenuated myocardial injury and decreased myocardial fibrosis. Our results in vitro revealed that IL‐38 affects the phenotype of dendritic cells (DCs) and IL‐38 plus troponin I (TNI)‐treated tolerogenic DCs dampened adaptive immune response when co‐cultured with CD4⁺T cells. In conclusion, IL‐38 plays a protective effect in ventricular remodelling post‐MI, one possibility by influencing DCs to attenuate inflammatory response. Therefore, targeting IL‐38 may hold a new therapeutic potential in treating MI.

Protective Effects of Euthyroidism Restoration on Mitochondria Function and Quality Control in Cardiac Pathophysiology

Mitochondrial dysfunctions are major contributors to heart disease onset and progression. Under ischemic injuries or cardiac overload, mitochondrial-derived oxidative stress, Ca²⁺ dis-homeostasis, and inflammation initiate cross-talking vicious cycles leading to defects of mitochondrial DNA, lipids, and proteins, concurrently resulting in fatal energy crisis and cell loss. Blunting such noxious stimuli and preserving mitochondrial homeostasis are essential to cell survival. In this context, mitochondrial quality control (MQC) represents an expanding research topic and therapeutic target in the field of cardiac physiology. MQC is a multi-tier surveillance system operating at the protein, organelle, and cell level to repair or eliminate damaged mitochondrial components and replace them by biogenesis. Novel evidence highlights the critical role of thyroid hormones (TH) in regulating multiple aspects of MQC, resulting in increased organelle turnover, improved mitochondrial bioenergetics, and the retention of cell function. In the present review, these emerging protective effects are discussed in the context of cardiac ischemia-reperfusion (IR) and heart failure, focusing on MQC as a strategy to blunt the propagation of connected dangerous signaling cascades and limit adverse remodeling. A better understanding of such TH-dependent signaling could provide insights into the development of mitochondria-targeted treatments in patients with cardiac disease.

RETRACTED: Gastrodin protects rat cardiomyocytes H9c2 from hypoxia-induced injury by up-regulation of microRNA-21

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Author. The journal contacted the authors for their response to the following remark from Dr Elisabeth Bik regarding this paper: ‘This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels. Despite these similarities, these papers are authored by researchers from different departments and institutes, with almost no overlap in authors’. The authors failed to respond to this directly but instead requested the journal to retract the paper on the basis that the data were not represented accurately and new results have shown inconsistency with what has been reported in this paper. The authors apologise for any misconceptions that this paper may have resulted in.

Innate Immune Signaling and Its Role in Metabolic and Cardiovascular Diseases

The innate immune system is an evolutionarily conserved system that senses and defends against infection and irritation. Innate immune signaling is a complex cascade that quickly recognizes infectious threats through multiple germline-encoded cell surface or cytoplasmic receptors and transmits signals for the deployment of proper countermeasures through adaptors, kinases, and transcription factors, resulting in the production of cytokines. As the first response of the innate immune system to pathogenic signals, inflammatory responses must be rapid and specific to establish a physical barrier against the spread of infection and must subsequently be terminated once the pathogens have been cleared. Long-lasting and low-grade chronic inflammation is a distinguishing feature of type 2 diabetes and cardiovascular diseases, which are currently major public health problems. Cardiometabolic stress-induced inflammatory responses activate innate immune signaling, which directly contributes to the development of cardiometabolic diseases. Additionally, although the innate immune elements are highly conserved in higher-order jawed vertebrates, lower-grade jawless vertebrates lack several transcription factors and inflammatory cytokine genes downstream of the Toll-like receptors (TLRs) and retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) pathways, suggesting that innate immune signaling components may additionally function in an immune-independent way. Notably, recent studies from our group and others have revealed that innate immune signaling can function as a vital regulator of cardiometabolic homeostasis independent of its immune function. Therefore, further investigation of innate immune signaling in cardiometabolic systems may facilitate the discovery of new strategies to manage the initiation and progression of cardiometabolic disorders, leading to better treatments for these diseases. In this review, we summarize the current progress in innate immune signaling studies and the regulatory function of innate immunity in cardiometabolic diseases. Notably, we highlight the immune-independent effects of innate immune signaling components on the development of cardiometabolic disorders.

Inhibition of microRNA-155 attenuates sympathetic neural remodeling following myocardial infarction via reducing M1 macrophage polarization and inflammatory responses in mice

Inflammation plays an important role in sympathetic neural remodeling induced by myocardial infarction (MI). MiR-155 is a vital regulator of inflammatory responses, and macrophage-secreted miR-155 promotes cardiac fibrosis and hypertrophy. However, whether miR-155 influences MI-induced sympathetic neural remodeling is not clear. Therefore, we examined the role of miR-155 in MI-induced sympathetic neural remodeling and the related mechanisms in both an mouse model and in lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs). Our data showed that miR-155 expression was significantly enhanced in the myocardial tissues of MI mice compared to sham mice. Also, MI up-regulated the electrophysiological parameters, M1 macrophage polarization, inflammatory responses, and suppressor of cytokine signaling 1 (SOCS1) expression, which coincided with the increased expression of sympathetic nerve remodeling markers(nerve growth factor, tyrosine hydroxylase and growth-associated protein 43). Except for SOCS1, these proteins were attenuated by miR-155 antagomir. In vitro, LPS-stimulation promoted miR-155 expression in BMDMs. Consistent with the in vivo findings, miR-155 antagomir diminished the LPS-induced M1 macrophage polarization, nuclear factor (NF)-κB activation, and the expression of pro-inflammatory factors and nerve growth factor; but it increased the expression of SOCS1. Inversely, miR-155 agomir significantly potentiated LPS-induced pathophysiological effects in BMDMs. MiR-155 agomir-induced effects were reversed by the NF-κB inhibitor. Mechanistically, treatment with siRNA against SOCS1 augmented the aforementioned LPS-mediated activities, which were antagonized by the addition of miR-155 antagomir. In conclusion, miR-155 inhibition downregulated NGF expression via decreasing M1 macrophage polarization and inflammatory responses dependent on the SOCS1/NF-κB pathway, subsequently diminishing MI-induced sympathetic neural remodeling and ventricular arrhythmias (VAs).

Regulatory role of IKKɑ in myocardial ischemia/reperfusion injury by the determination of M1 versus M2 polarization of macrophages

The IκB kinase (IKK) complex plays a well-documented role in cancer and immune system. This function has been widely attributed to its role as the master regulator of the NF-κB family. Particularly, IKKɑ, a member of IKK complex, is reported to have various regulating effects in inflammatory and malignant diseases. However, its role as well as its mechanism of function in macrophages following myocardial ischemia and reperfusion (I/R) injury remains unexplored. In vivo, sham or I/R operations were performed on macrophage-specific IKKɑ knockout (mIKKɑ^-/-) mice and their IKKɑ^flox/flox littermates. We ligated the left anterior descending (LAD) coronary artery of I/R groups simulating ischemia for 30 min, followed by a reperfusion period of 3 days and 7 days, respectively. The hearts of mIKKɑ^-/- mice exhibited significantly increased inflammation and macrophage aggregation as compared to their IKKɑ^flox/flox littermates. Moreover, in the mIKKɑ^-/- group subjected to I/R macrophages had a tendency to polarize to M1 phenotype. In vitro, we stimulated RAW264.7 cells with Lipopolysaccharides (LPS) after infection by the lentivirus, either knocking-down or overexpressing IKKɑ. We discovered that a deficiency of IKKɑ in RAW264.7 caused increased expression of pro-inflammatory markers compared to normal RAW264.7 after LPS stimulation. Inversely, pro-inflammatory factors were inhibited with IKKɑ overexpression. Mechanistically, IKKɑ directly combined with RelB to regulate macrophage polarization. Furthermore, IKKɑ regulated MEK1/2-ERK1/2 and downstream p65 signaling cascades after LPS stimulation. Overall, our data reveals that IKKɑ is a novel mediator protecting against the development of myocardial I/R injury via negative regulation of macrophage polarization to M1 phenotype. Thus, IKKɑ may serve as a valuable therapeutic target for the treatment of myocardial I/R injury.

Effect of renal sympathetic denervation on ventricular and neural remodeling

Background

This study assessed the therapeutic effects of renal sympathetic denervation (RDN) on post-myocardial infarction (MI) ventricular remodeling and sympathetic neural remodeling in dogs. The possible mechanisms and optimal time for treatment are discussed.

Methods

We randomly assigned 30 dogs to five groups: RDN 1 week before MI (RDN1w + MI; n = 6), RDN 1 week after MI (MI1w + RDN; n = 6), RDN 2 weeks after MI (MI2w + RDN; n = 6), control (N; n = 6), and MI (n = 6). A canine model of myocardial infarction was established by interventional occlusion with a gelatin sponge via the femoral artery. Brain natriuretic peptide (BNP) and endothelin-1 (ET-1) levels were measured and echocardiography was performed to assess cardiac function and heart size. All dogs were killed at the end of the experiment and samples of cardiac and renal arteries were obtained. The expression of matrix metalloproteinase (MMP)-2 and MMP-9 in cardiac and of tyrosine hydroxylase (TH) in renal arteries was assessed by immunohistochemistry. Sympathetic innervations in the infarction border zone were investigated via Western blotting and real-time PCR.

Results

Left ventricular function in the MI group decreased significantly, while plasma BNP and ET-1 levels as well as MMP-2 and MMP-9 expression increased. Compared with the MI group, the RD groups showed significantly reduced MMP‑2, MMP‑9, TH, and growth-associated protein (GAP) 43 expression in the RDN1w + MI, MI1w + RDN, and MI2w + RDN groups was significantly improved. Additionally, the expression of TH in renal arteries decreased after RDN.

Conclusion

RDN has preventive and therapeutic effects on post-MI ventricular remodeling and sympathetic neural remodeling. The mechanism of RDN is likely mediated through restraint of renal sympathetic nerve activity.

Synergistic effects of HMG-CoA reductase inhibitor and angiotensin II receptor blocker on load-induced heart failure

5-Hydroxy-3-methylglutaryl-CoA reductase inhibitors (statins) have beneficial effects in patients with heart failure (HF), regardless of serum cholesterol levels. However, their synergic effects with angiotensin II receptor blocker (ARB) remain to be established. We assessed the existence and potential underlying mechanisms of the effects of combined ARB [losartan (LOS)] and statin [simvastatin (SIM)] on cardiac function in rats and mice with load-induced HF. Salt-loaded Dahl salt-sensitive (DS) rats were treated with vehicle, LOS, SIM, or LOS + SIM for 8 weeks. To mimic load-induced HF in vitro, cultured neonatal rat cardiomyocytes (NRCM) were cyclically stretched. We also investigated the effect of LOS + SIM on pressure overload-induced HF using mice with transverse aortic constriction (TAC). LOS + SIM improved left ventricular (LV) function and reduced LV hypertrophy more than the monotherapies in both salt-loaded DS rats and TAC-operated mice. LV-tissue increases in Rho kinase and matrix metalloproteinase-9 activity were decreased to a greater extent by LOS + SIM than by LOS and SIM monotherapies. Plasma levels of Exp-3174, a LOS metabolite, were higher in LOS + SIM-treated DS rats than in LOS-treated rats. Stretch-induced hypertrophy of NRCM pretreated with SIM + Exp-3174 was significantly attenuated from that with LOS, Exp-3174, SIM, or LOS + SIM. SIM administration significantly enhanced mitophagy in mouse hearts after TAC. However, LOS + SIM reduced mitophagy, and the salutary effect of SIM in mouse hearts after TAC was abolished in AT1R^-/- mice. In conclusion, LOS and SIM have beneficial myocardial effects on load-induced HF via differential pleiotropic effects. Thus, combination therapy of these drugs thus has potential as a therapeutic strategy for HF.

Novel Role for the Immunoproteasome Subunit PSMB10 in Angiotensin II-Induced Atrial Fibrillation in Mice

Angiotensin II (Ang II) and inflammation are associated with pathogenesis of atrial fibrillation (AF), but the underlying molecular mechanisms of these events remain unknown. The immunoproteasome has emerged as a critical regulator of inflammatory responses. Here, we investigated its role in Ang II-induced AF in immunosubunit PSMB10 (also known as β2i or LMP10) knockout (KO) mice. AF was induced by Ang II infusion (2000 ng/min per kg). PSMB10 expression and trypsin-like activity were increased in atrial tissues and serum from Ang II-treated mice or serum from patients with AF. Moreover, Ang II-infused wild-type (WT) mice had a higher AF and increased atrial fibrosis, reactive oxygen species production, and inflammation compared with saline-treated WT animals. These effects were attenuated in PSMB10 KO mice but were aggravated in recombinant adeno-associated virus serotype 9-PSMB10-treated mice. Administration of IKKβ-specific inhibitor IMD 0354 reduced Ang II-induced AF, reactive oxygen species production, inflammation, and NF-kB (nuclear factor-kB) activation. Mechanistically, Ang II infusion upregulated PSMB10 expression to promote PTEN (phosphatase and tensin homolog deleted on chromosome ten) degradation and AKT1 activation, which not only activated TGF-β-Smad2/3 signaling leading to cardiac fibrosis but also induced IKKβ activation and ubiquitin-mediated degradation of IkBα ultimately resulting in activation of NF-kB target genes (IL [interleukin]-1β, IL-6, NOX [NADPH oxidase] 2, NOX4, and CX43 [connexin 43]). Overall, our study identifies immunosubunit PSMB10 as a novel regulator that contributes to Ang II-induced AF and suggests that inhibition of PSMB10 may represent a potential therapeutic target for treating hypertensive AF.

Thyroid hormones decrease the proinflammatory TLR4/NF-κβ pathway and improve functional parameters of the left ventricle of infarcted rats

Myocardial infarction leads to oxidative stress and promotes activation of the TLR4/NF-κβ proinflammatory pathway. Thyroid hormones (TH) are known to be cardioprotective after infarction. However, there are no studies evaluating whether TH could modulate this pathway in the heart. This study aimed to verify the effect of thyroid hormones on the TLR4/NF-κβ pathway after myocardial infarction. Male Wistar rats were allocated into the following groups: Sham-operated (SHAM), sham-operated + TH (SHAMT), infarcted (AMI) and infarcted + TH (AMIT). The treated rats received T4 and T3 (8 and 2 μg 100 g^-1 day^-1) for 12 days by gavage. Subsequently, the animals were evaluated by echocardiography and euthanized, and the left ventricle was collected for biochemical and molecular analyses. TH modulates TLR4/NF-κβ expression in the infarcted hearts of rats and decreases xanthine oxidase expression. These effects were related to cardiac functional improvement after infarction. The cardioprotective effects of T3 and T4 seem to involve an anti-inflammatory action.

Activin A inhibition attenuates sympathetic neural remodeling following myocardial infarction in rats

Inflammation serves a critical role in driving sympathetic neural remodeling following myocardial infarction (MI), and activin A has been implicated as an important mediator of the inflammatory response post-MI. However, whether activin A impacts sympathetic neural remodeling post-MI remains unclear. In the present study, the authors assessed the effects of activin A on sympathetic neural remodeling in a rat model of MI. Rats were randomly divided into sham, MI, and MI + follistatin-300 (FS, activin A inhibitor) groups. Cardiac tissues from the peri-infarct zone were assessed for expression of sympathetic neural remodeling and inflammatory factors in rats 4 weeks post-MI by western blotting and immunohistochemical methods. Heart function was assessed by echocardiography. It is demonstrated that FS administration significantly reduced post-MI upregulation of activin A, nerve growth factor protein lever, and the density of nerve fibers with positive and protein expression of sympathetic neural remodeling markers in nerve fibers, which included growth associated protein 43 and tyrosine hydroxylase. In addition, inhibition of activin A reduced cardiac inflammation post-MI based on the reduction of i) interleukin-1 and tumor necrosis factor-α protein expression, ii) numbers and/or proportional area of infiltrating macrophages and myofibroblasts and iii) phosphorylated levels of p65 and IκBα. Furthermore, activin A inhibition lessened heart dysfunction post-MI. These results suggested that activin A inhibition reduced sympathetic neural remodeling post-MI in part through inhibition of the inflammatory response. The current study implicates activin A as a potential therapeutic target to circumvent sympathetic neural remodeling post-MI.

Vinpocetine Attenuates Pathological Cardiac Remodeling by Inhibiting Cardiac Hypertrophy and Fibrosis

PURPOSE

Pathological cardiac remodeling, characterized by cardiac hypertrophy and fibrosis, is a pathological feature of many cardiac disorders that leads to heart failure and cardiac arrest. Vinpocetine, a derivative of the alkaloid vincamine, has been used for enhancing cerebral blood flow to treat cognitive impairment. However, its role in pathological cardiac remodeling remains unknown. The aim of this study is to examine the effect of vinpocetine on pathological cardiac remodeling induced by chronic stimulation with angiotensin II (Ang II).

METHODS

Mice received Ang II infusion via osmotic pumps in the presence of vehicle or vinpocetine. Cardiac hypertrophy and fibrosis were assessed by morphological, histological, and biochemical analyses. Mechanistic studies were carried out in vitro with isolated mouse adult cardiac myocytes and fibroblasts.

RESULTS

We showed that chronic Ang II infusion caused cardiac hypertrophy and fibrosis, which were all significantly attenuated by systemic administration of vinpocetine. In isolated adult mouse cardiomyocytes, vinpocetine suppressed Ang II-stimulated myocyte hypertrophic growth. In cultured cardiac fibroblasts, vinpocetine suppressed TGFβ-induced fibroblast activation and matrix gene expression, consistent with its effect in attenuating cardiac fibrosis. The effects of vinpocetine on cardiac myocyte hypertrophy and fibroblast activation are likely mediated by targeting cyclic nucleotide phosphodiesterase 1 (PDE1).

CONCLUSIONS

Our results reveal a novel protective effect of vinpocetine in attenuating pathological cardiac remodeling through suppressing cardiac myocyte hypertrophic growth and fibroblast activation and fibrotic gene expression. These studies may also shed light on developing novel therapeutic agents for antagonizing pathological cardiac remodeling.

Identification of potentially relevant genes for myocardial infarction using RNA sequencing data analysis

Myocardial infarction (MI) is a heart disease with high morbidity and mortality rates, thus it is critical to identify genes that serve roles during its pathogenesis. The objective of the present study was to identify potentially relevant genes during the progression of the disease. Blood samples from patients with MI and normal controls (n=3/group) were obtained, the RNA was extracted and cDNA libraries were established. RNA sequencing (RNA-seq) was performed on a HiSeq 2500 platform and fragments per kilobase of exon per million fragments mapped was utilized to calculate the gene expression value following preprocessing of the RNA-seq data. Electronic validation of several identified differentially expressed genes (DEGs) was performed on a Gene Expression Omnibus (GEO) dataset GSE59867 (390 cases and 46 healthy controls). Functional enrichment and protein-protein interaction network analysis was conducted for DEGs. A total of 977 DEGs, including 817 upregulated and 160 downregulated genes were identified in patients with MI. These DEGs were significantly enriched for ‘positive regulation of the immune system process,’ ‘inflammatory response,’ ‘regulation of I-kappaB-kinase/NF-kappaB signaling’ and ‘TNF signaling pathway’. A protein-protein interaction network of the top 40 DEGs was used to identify high degree genes, including interferon induced protein with tetratricopeptide repeats 3 (IFIT3), MX dynamin like GTPase 1 (MX1), major histocompatibility complex, class II, DQ α1 (HLA-DQA1), RAR related orphan receptor A (RORA), prostaglandin D2 synthase (PTGDS), cysteine rich protein 2 (CRIP2), collagen type VI α 2 chain (COL6A2) and S100 calcium binding protein P (S100P). The results of validation in the GEO dataset were consistent with the sequencing analysis. A total of eight genes, including IFIT3, MX1, HLA-DQA1, RORA, PTGDS, CRIP2, COL6A2 and S100P may therefore be considered as potentially relevant genes in the pathology of MI.

4-Hydroxy-N-[3,5-bis(trifluoromethyl)phenyl]-1,2,5-thiadiazole-3-carboxamide: a novel inhibitor of the canonical NF-κB cascade

The NF-κB signaling pathway is a validated oncological target. Here, we applied scaffold hopping to IMD-0354, a presumed IKKβ inhibitor, and identified 4-hydroxy-N-[3,5-bis(trifluoromethyl)phenyl]-1,2,5-thiadiazole-3-carboxamide (4) as a nM-inhibitor of the NF-κB pathway. However, both 4 and IMD-0354, being potent inhibitors of the canonical NF-κB pathway, were found to be inactive in human IKKβ enzyme assays.

A peptide vaccine targeting angiotensin II attenuates the cardiac dysfunction induced by myocardial infarction

A peptide vaccine targeting angiotensin II (Ang II) was recently developed as a novel treatment for hypertension to resolve the problem of noncompliance with pharmacotherapy. Ang II plays a crucial role in the pathogenesis of cardiac remodeling after myocardial infarction (MI), which causes heart failure. In the present study, we examined whether the Ang II vaccine is effective in preventing heart failure. The injection of the Ang II vaccine in a rat model of MI attenuated cardiac dysfunction in association with an elevation in the serum anti-Ang II antibody titer. Furthermore, any detrimental effects of the Ang II vaccine were not observed in the rats that underwent sham operations. Treatment with immunized serum from Ang II vaccine-injected rats significantly suppressed post-MI cardiac dysfunction in MI rats and Ang II-induced remodeling-associated signaling in cardiac fibroblasts. Thus, our present study demonstrates that the Ang II vaccine may provide a promising novel therapeutic strategy for preventing heart failure.

Interleukin-37 and Dendritic Cells Treated With Interleukin-37 Plus Troponin I Ameliorate Cardiac Remodeling After Myocardial Infarction

BACKGROUND

Excessive immune-mediated inflammatory reactions play a deleterious role in postinfarction ventricular remodeling. Interleukin-37 (IL-37) emerges as an inhibitor of both innate and adaptive immunity. However, the exact role of IL-37 and IL-37 plus troponin I (TnI)-treated dendritic cells (DCs) in ventricular remodeling after myocardial infarction (MI) remains elusive.

METHODS AND RESULTS

MI was induced by permanent ligation of the left anterior descending artery. Our results showed that treatment with recombinant human IL-37 significantly ameliorated ventricular remodeling after MI, as demonstrated by decreased infarct size, better cardiac function, lower mortality, restricted inflammatory responses, decreased myocardial fibrosis, and inhibited cardiomyocyte apoptosis. In vitro, we examined the phenotype of IL-37 plus TnI-conditioned DCs of male C57BL/6 mice and their capacity to influence the number of regulatory T cells. Our results revealed that IL-37 plus TnI-conditioned DCs obtained the characteristics of tolerogenic DCs (tDCs) and expanded the number of regulatory T cells when co-cultured with splenic CD4+ T cells. Interestingly, we also found that adoptive transfer of these antigen-loaded tDCs markedly increased the number of regulatory T cells in the spleen, attenuated the infiltration of inflammatory cells in the infarct hearts, decreased myocardial fibrosis, and improved cardiac function.

CONCLUSIONS

Our results reveal a beneficial role of IL-37 or tDCs treated with IL-37 plus TnI in post-MI remodeling that is possibly mediated by reestablishing a tolerogenic immune response, indicating that IL-37 or adoptive transfer of IL-37 plus TnI-treated tDCs may be a novel therapeutic strategy for ventricular remodeling after MI.

Abrogation of CC chemokine receptor 9 ameliorates ventricular remodeling in mice after myocardial infarction

CC chemokine receptor 9 (CCR9), which is a unique receptor for CC chemokine ligand (CCL25), is mainly expressed on lymphocytes, dendritic cells (DCs) and monocytes/macrophages. CCR9 mediates the chemotaxis of inflammatory cells and participates in the pathological progression of inflammatory diseases. However, the role of CCR9 in the pathological process of myocardial infarction (MI) remains unexplored; inflammation plays a key role in this process. Here, we used CCR9 knockout mice to determine the functional significance of CCR9 in regulating post-MI cardiac remodeling and its underlying mechanism. MI was induced by surgical ligation of the left anterior descending coronary artery in CCR9 knockout mice and their CCR9+/+ littermates. Our results showed that the CCR9 expression levels were up-regulated in the hearts of the MI mice. Abrogation of CCR9 improved the post-MI survival rate and left ventricular (LV) dysfunction and decreased the infarct size. In addition, the CCR9 knockout mice exhibited attenuated inflammation, apoptosis, structural and electrical remodeling compared with the CCR9+/+ MI mice. Mechanistically, CCR9 mainly regulated the pathological response by interfering with the NF-κB and MAPK signaling pathways. In conclusion, the data reveal that CCR9 serves as a novel modulator of pathological progression following MI through NF-κB and MAPK signaling.

Developmental Biology and Regenerative Medicine: Addressing the Vexing Problem of Persistent Muscle Atrophy in the Chronically Torn Human Rotator Cuff

Persistent muscle atrophy in the chronically torn rotator cuff is a significant obstacle for treatment and recovery. Large atrophic changes are predictive of poor surgical and nonsurgical outcomes and frequently fail to resolve even following functional restoration of loading and rehabilitation. New insights into the processes of muscle atrophy and recovery gained through studies in developmental biology combined with the novel tools and strategies emerging in regenerative medicine provide new avenues to combat the vexing problem of muscle atrophy in the rotator cuff. Moving these treatment strategies forward likely will involve the combination of surgery, biologic/cellular agents, and physical interventions, as increasing experimental evidence points to the beneficial interaction between biologic therapies and physiologic stresses. Thus, the physical therapy profession is poised to play a significant role in defining the success of these combinatorial therapies. This perspective article will provide an overview of the developmental biology and regenerative medicine strategies currently under investigation to combat muscle atrophy and how they may integrate into the current and future practice of physical therapy.

Improvement of Left Ventricular Remodelling by Inhibition of NF-κB in a Rat Model of Myocardial Infarction

BACKGROUND

To investigate the effects of inhibition of NF-κB activation on left ventricular (LV) remodelling in a rat model of myocardial infarction (MI).

METHODS

The acute MI model was established by ligation of left anterior descending coronary artery. Pyrrolidine dithiocarbamate (PDTC) (20mg/kg, Qd) was administered intraperitoneally to inhibit NF-κB activation. Eight weeks later, the cardiac structure and LV ejection fraction were assessed with echocardiography. The rat body, heart, and LV weights were measured to calculate LV mass indices. Activation of NF-κB in non-infarcted myocardium was detected by a TransAM NF-κB p65 Transcription Factor Assay Kit. Cardiac collagen volume fraction was evaluated by Masson staining.

RESULTS

Eight weeks after the MI model was established, the LV posterior wall thickness in PDTC and MI group was 1.75±0.07mm and 1.85±0.07mm respectively (p<0.05). The LV mass index in the PDTC group (2.53±0.09) was lower than in the MI group (2.65±0.08, p<0.05). The LVEF in the PDTC group (63.89%±4.21%) was higher than in the MI group (42.73%±8.94%, p<0.05). The interstitial collagen deposition in the non-infarcted myocardium in the PDTC group was less than in the MI group (7.25%±1.88% vs. 10.09%±2.19%, p<0.05).

CONCLUSION

Inhibition of activation of NF-κB may result in improvement of myocardial remodelling after myocardial infarction, which is possibly attributable to reduced collagen deposition in non-infarcted areas.

Induction of substantial myocardial regeneration by an active fraction of the Chinese herb Rosa laevigata Michx

Background

The replacement of lost cardiac tissues by regenerated myocardium would be a therapeutic ideal for myocardial infarction. The objective of this study was therefore to evaluate the ability of an active fraction that was isolated from Rosa laevigata Michx in therapeutic cardiomyogenesis in a myocardial infarction rat model.

Methods

The myocardial infarction animal model was induced by the permanent ligation of the left anterior descending coronary artery in rats. The active fraction, which improves the survival rate and prevents ischemic reperfusion damage, was used to test the therapeutic effect of this fraction on myocardial infarction.

Results

The oral administration of the active fraction for 4 weeks could progressively restore the decreased cardiac function due to myocardial infarction. The significantly improved cardiac function was probably attributed to the active fraction-induced myocardial regeneration, which replaced the lost cardiac tissues in the myocardial infarction animals.

Conclusions

The property of this active fraction appears to be entirely novel and may provide a potential therapeutic alternative for myocardial infarction.