Role of cytokines in myocardial ischemia and reperfusion

Marine natural products: potential agents for depression treatment

Depression is a common psychiatric disorder. Due to the disadvantages of current clinical drugs, including poor efficacy and unnecessary side effects, research has shifted to novel natural products with minimal or no adverse effects as therapeutic alternatives. The ocean is a vast ecological home, with a wide variety of organisms that can produce a large number of natural products with unique structures, some of which have neuroprotective effects and are a valuable source for the development of new drugs for depression. In this review, we analyzed preclinical and clinical studies of natural products derived from marine organisms with antidepressant potential, including the effects on the pathophysiology of depression, and the underlying mechanisms of these effects. It is expected to provide a reference for the development of new antidepressant drugs.

Cardiac SARS-CoV-2 Infection, Involvement of Cytokines in Postmortem Immunohistochemical Study

In the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, significant attention was given to pulmonary manifestations. However, cardiac involvement is increasingly recognized as a critical factor influencing the prognosis, leading to myocardial damage, heart failure, acute coronary syndromes, potentially lethal arrhythmic events, and sudden cardiac death. Despite these findings, there is a lack of studies detailing the necroscopic, macroscopic, and microscopic cardiac changes associated with SARS-CoV-2. This study aimed to investigate the presence of SARS-CoV-2 viral proteins in cardiac tissue using immunohistochemical techniques to assess viral tropism. The analysis of cardiac tissue samples from deceased subjects, in different stages of conservation, confirmed to be positive for SARS-CoV-2 via reverse transcriptase-polymerase chain reaction (RT-PCR), showed immunopositivity for the SARS-CoV-2-NP viral antigen in 33% of cases. Notably, the presence of leukocyte infiltrates sufficient for diagnosing lymphocytic myocarditis was not observed. The central proinflammatory cytokines involved in the pathogenetic mechanism of coronavirus disease 19 (COVID-19) were researched using the immunohistochemical method. A significant increase in cytokine expression was detected, indicating myocardial involvement and dysfunction during SARS-CoV-2 infection. These findings suggest that the immunohistochemical detection of SARS-CoV-2 viral antigens and inflammatory cytokine expression in cardiac tissue could be crucial for a proper forensic assessment of the cause of death, even in sudden cardiac death.

From Beats to Metabolism: the Heart at the Core of Interorgan Metabolic Cross Talk

The heart, once considered a mere blood pump, is now recognized as a multifunctional metabolic and endocrine organ. Its function is tightly regulated by various metabolic processes, at the same time it serves as an endocrine organ, secreting bioactive molecules that impact systemic metabolism. In recent years, research has shed light on the intricate interplay between the heart and other metabolic organs, such as adipose tissue, liver, and skeletal muscle. The metabolic flexibility of the heart and its ability to switch between different energy substrates play a crucial role in maintaining cardiac function and overall metabolic homeostasis. Gaining a comprehensive understanding of how metabolic disorders disrupt cardiac metabolism is crucial, as it plays a pivotal role in the development and progression of cardiac diseases. The emerging understanding of the heart as a metabolic and endocrine organ highlights its essential contribution to whole body metabolic regulation and offers new insights into the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disorders. In this review, we provide an in-depth exploration of the heart's metabolic and endocrine functions, emphasizing its role in systemic metabolism and the interplay between the heart and other metabolic organs. Furthermore, emerging evidence suggests a correlation between heart disease and other conditions such as aging and cancer, indicating that the metabolic dysfunction observed in these conditions may share common underlying mechanisms. By unraveling the complex mechanisms underlying cardiac metabolism, we aim to contribute to the development of novel therapeutic strategies for metabolic diseases and improve overall cardiovascular health.

GSK-3α aggravates inflammation, metabolic derangement, and cardiac injury post-ischemia/reperfusion

Reperfusion after acute myocardial infarction further exaggerates cardiac injury and adverse remodeling. Irrespective of cardiac cell types, loss of specifically the α isoform of the protein kinase GSK-3 is protective in chronic cardiac diseases. However, the role of GSK-3α in clinically relevant ischemia/reperfusion (I/R)-induced cardiac injury is unknown. Here, we challenged cardiomyocyte-specific conditional GSK-3α knockout (cKO) and littermate control mice with I/R injury and investigated the underlying molecular mechanism using an in vitro GSK-3α gain-of-function model in AC16 cardiomyocytes post-hypoxia/reoxygenation (H/R). Analysis revealed a significantly lower percentage of infarct area in the cKO vs. control hearts post-I/R. Consistent with in vivo findings, GSK-3α overexpression promoted AC16 cardiomyocyte death post-H/R which was accompanied by an induction of reactive oxygen species (ROS) generation. Consistently, GSK-3α gain-of-function caused mitochondrial dysfunction by significantly suppressing mitochondrial membrane potential. Transcriptomic analysis of GSK-3α overexpressing cardiomyocytes challenged with hypoxia or H/R revealed that NOD-like receptor (NLR), TNF, NF-κB, IL-17, and mitogen-activated protein kinase (MAPK) signaling pathways were among the most upregulated pathways. Glutathione and fatty acid metabolism were among the top downregulated pathways post-H/R. Together, these observations suggest that loss of cardiomyocyte-GSK-3α attenuates cardiac injury post-I/R potentially through limiting the myocardial inflammation, mitochondrial dysfunction, and metabolic derangement. Therefore, selective inhibition of GSK-3α may provide beneficial effects in I/R-induced cardiac injury and remodeling. KEY MESSAGES: GSK-3α promotes cardiac injury post-ischemia/reperfusion (I/R). GSK-3α regulates inflammatory and metabolic pathways post-hypoxia/reoxygenation (H/R). GSK-3α overexpression upregulates NOD-like receptor (NLR), TNF, NF-kB, IL-17, and MAPK signaling pathways in cardiomyocytes post-H/R. GSK-3α downregulates glutathione and fatty acid metabolic pathways in cardiomyocytes post-H/R.

Continuous short-term acclimation to moderate cold elicits cardioprotection in rats, and alters β-adrenergic signaling and immune status

Moderate cold acclimation (MCA) is a non-invasive intervention mitigating effects of various pathological conditions including myocardial infarction. We aim to determine the shortest cardioprotective regimen of MCA and the response of β1/2/3-adrenoceptors (β-AR), its downstream signaling, and inflammatory status, which play a role in cell-survival during myocardial infarction. Adult male Wistar rats were acclimated (9 °C, 1-3-10 days). Infarct size, echocardiography, western blotting, ELISA, mitochondrial respirometry, receptor binding assay, and quantitative immunofluorescence microscopy were carried out on left ventricular myocardium and brown adipose tissue (BAT). MultiPlex analysis of cytokines and chemokines in serum was accomplished. We found that short-term MCA reduced myocardial infarction, improved resistance of mitochondria to Ca2+-overload, and downregulated β1-ARs. The β2-ARs/protein kinase B/Akt were attenuated while β3-ARs translocated on the T-tubular system suggesting its activation. Protein kinase G (PKG) translocated to sarcoplasmic reticulum and phosphorylation of AMPKThr172 increased after 10 days. Principal component analysis revealed a significant shift in cytokine/chemokine serum levels on day 10 of acclimation, which corresponds to maturation of BAT. In conclusion, short-term MCA increases heart resilience to ischemia without any negative side effects such as hypertension or hypertrophy. Cold-elicited cardioprotection is accompanied by β1/2-AR desensitization, activation of the β3-AR/PKG/AMPK pathways, and an immunomodulatory effect.

Longitudinal association of epicardial and thoracic adipose tissues with coronary and cardiac characteristics in psoriasis

Background

s: Psoriasis is a disease of systemic inflammation associated with increased cardiometabolic risk. Epicardial adipose tissue (EAT) and thoracic adipose tissue (TAT) are contributing factors for atherosclerosis and cardiac dysfunction. We strove to assess the longitudinal impact of the EAT and TAT on coronary and cardiac characteristics in psoriasis.

Methods

The study consisted of 301 patients with baseline coronary computed tomography angiography (CTA), of which 139 had four-year follow up scans. EAT and TAT volumes from non-contrast computed tomography scans were quantified by an automated segmentation framework. Coronary plaque characteristics and left ventricular (LV) mass were quantified by CTA.

Results

When stratified by baseline EAT and TAT volume quartiles, a stepwise significant increase in cardiometabolic parameters was observed. EAT and TAT volumes associated with fibro-fatty burden (FFB) (TAT: ρ = 0.394, P < 0.001; EAT: ρ = 0.459, P < 0.001) in adjusted models. Only EAT had a significant four-year time-dependent association with FFB in fully adjusted models (β = 0.307 P = 0.003), whereas only TAT volume associated with myocardial injury in fully adjusted models (TAT: OR = 1.57 95 % CI = (1.00-2.60); EAT: OR = 1.46 95 % CI = (0.91-2.45). Higher quartiles of EAT and TAT had increased LV mass and developed strong correlation (TAT: ρ = 0.370, P < 0.001; EAT: ρ = 0.512, P < 0.001).

Conclusions

Our study is the first to explore how both EAT and TAT volumes associate with increased cardiometabolic risk profile in an inflamed psoriasis cohorts and highlight the need for further studies on its use as a potential prognostic tool for high-risk coronary plaques and cardiac dysfunction.

NF-κB Transcriptional Activity Indispensably Mediates Hypoxia–Reoxygenation Stress-Induced microRNA-210 Expression

Ischemia–reperfusion (I-R) injury is a cardinal pathophysiological hallmark of ischemic heart disease (IHD). Despite significant advances in the understanding of what causes I-R injury and hypoxia–reoxygenation (H-R) stress, viable molecular strategies that could be targeted for the treatment of the deleterious biochemical pathways activated during I-R remain elusive. The master hypoxamiR, microRNA-210 (miR-210), is a major determinant of protective cellular adaptation to hypoxia stress but exacerbates apoptotic cell death during cellular reoxygenation. While the hypoxia-induced transcriptional up-regulation of miR-210 is well delineated, the cellular mechanisms and molecular entities that regulate the transcriptional induction of miR-210 during the cellular reoxygenation phase have not been elucidated yet. Herein, in immortalized AC-16 cardiomyocytes, we delineated the indispensable role of the ubiquitously expressed transcription factor, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in H-R-induced miR-210 expression during cellular reoxygenation. Using dominant negative and dominant active expression vectors encoding kinases to competitively inhibit NF-κB activation, we elucidated NF-κB activation as a significant mediator of H-R-induced miR-210 expression. Ensuing molecular assays revealed a direct NF-κB-mediated transcriptional up-regulation of miR-210 expression in response to the H-R challenge that is characterized by the NF-κB-mediated reorchestration of the entire repertoire of histone modification changes that are a signatory of a permissive actively transcribed miR-210 promoter. Our study confers a novel insight identifying NF-κB as a potential novel molecular target to combat H-R-elicited miR-210 expression that fosters augmented cardiomyocyte cell death.

Early Growth Response-1: Friend or Foe in the Heart?

Cardiovascular disease is a major cause of mortality and morbidity worldwide. Early growth response-1 (Egr-1) plays a critical regulatory role in a range of experimental models of cardiovascular diseases. Egr-1 is an immediate-early gene and is upregulated by various stimuli including shear stress, oxygen deprivation, oxidative stress and nutrient deprivation. However, recent research suggests a new, underexplored cardioprotective side of Egr-1. The main purpose of this review is to explore and summarise the dual nature of Egr-1 in cardiovascular pathobiology.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

Post-ischemic cardioprotective potential of exogenous ubiquitin in myocardial remodeling late after ischemia/reperfusion injury

AIMS

Pretreatment with ubiquitin (UB) associates with preservation of heart function 3 days post-ischemia/reperfusion (I/R) injury. This study investigated the cardioprotective potential of exogenous UB late after myocardial I/R injury. To enhance the clinical relevance, UB treatment was started at the time of reperfusion and continued for 28 days post-I/R.

MAIN METHODS

Mice underwent ligation of the left anterior descending coronary artery for 45 min. At the time of reperfusion, mice were treated with UB or saline which was continued until 28 days post-I/R. Heart function was measured at 3, 7, 14 and 28 days post-I/R using echocardiography. Biochemical parameters of the heart and serum cytokines/chemokines levels were measured 28 days post-I/R.

KEY FINDINGS

I/R decreased heart function and induced LV dilation at all time points post-I/R. However, I/R + UB exhibited improved heart function throughout the observation period, while LV dilation was lower in I/R + UB group at 3, 14 and 28 days post-I/R. I/R-mediated increase in myocardial fibrosis, hypertrophy and apoptosis were significantly lower in I/R + UB vs. I/R. Collagen-1α1 and MMP-2 expression was lower, while MMP-9 and TIMP-2 expression was higher in I/R + UB vs. I/R. MYH-7B (hypertrophy marker) expression was lower in I/R + UB vs. I/R. GSK3β activation was lower (vs. Sham), while activation of ERK1/2 (vs. I/R) and AKT (vs. Sham) was higher in I/R + UB. Serum levels of IL-6, G-CSF and IL-2 were lower in I/R + UB vs. I/R.

SIGNIFICANCE

Post-ischemic UB treatment improves heart function, and associates with decreased myocardial fibrosis, apoptosis, hypertrophy and serum cytokine/chemokine levels.

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.

PPARβ/δ Is Required for Mesenchymal Stem Cell Cardioprotective Effects Independently of Their Anti-inflammatory Properties in Myocardial Ischemia-Reperfusion Injury

Myocardial infarction ranks first for the mortality worldwide. Because the adult heart is unable to regenerate, fibrosis develops to compensate for the loss of contractile tissue after infarction, leading to cardiac remodeling and heart failure. Adult mesenchymal stem cells (MSC) regenerative properties, as well as their safety and efficacy, have been demonstrated in preclinical models. However, in clinical trials, their beneficial effects are controversial. In an experimental model of arthritis, we have previously shown that PPARβ/δ deficiency enhanced the therapeutic effect of MSC. The aim of the present study was to compare the therapeutic effects of wild-type MSC (MSC) and MSC deficient for PPARβ/δ (KO MSC) perfused in an ex vivo mouse model of ischemia-reperfusion (IR) injury. For this purpose, hearts from C57BL/6J mice were subjected ex vivo to 30 min ischemia followed by 1-h reperfusion. MSC and KO MSC were injected into the Langendorff system during reperfusion. After 1 h of reperfusion, the TTC method was used to assess infarct size. Coronary effluents collected in basal condition (before ischemia) and after ischemia at 1 h of reperfusion were analyzed for their cytokine profiles. The dose-response curve for the cardioprotection was established ex vivo using different doses of MSC (3.10⁵, 6.10⁵, and 24.10⁵ cells/heart) and the dose of 6.10⁵ MSC was found to be the optimal concentration. We showed that the cardioprotective effect of MSC was PPARβ/δ-dependent since it was lost using KO MSC. Moreover, cytokine profiling of the coronary effluents collected in the eluates after 60 min of reperfusion revealed that MSC treatment decreases CXCL1 chemokine and interleukin-6 release compared with untreated hearts. This anti-inflammatory effect of MSC was also observed when hearts were treated with PPARβ/δ-deficient MSC. In conclusion, our study revealed that the acute cardioprotective properties of MSC in an ex vivo model of IR injury, assessed by a decreased infarct size at 1 h of reperfusion, are PPARβ/δ-dependent but not related to their anti-inflammatory effects.

Exploring the beneficial role of telmisartan in sepsis-induced myocardial injury through inhibition of high-mobility group box 1 and glycogen synthase kinase-3β/nuclear factor-κB pathway

In the present experimental study, cecal ligation and puncture significantly increased the myocardial injury assessed in terms of excess release of creative kinase-MB (CK-MB), cardiac troponin I (cTnI), interleukin (IL)-6 and decrease of IL-10 in the blood following 12 h of laparotomy procedure as compared to normal control. Also, a significant increase in protein expression levels of high-mobility group box 1 (HMGB1) and decreased phosphorylation of glycogen synthase kinase-3β (GSK-3β) was observed in the myocardial tissue as compared to normal control. A single independent administration of telmisartan (2 and 4 mg/kg) and AR-A014418 (1 and 2 mg/kg) substantially reduced sepsis-induced myocardial injury in terms of decrease levels of CK-MB, cTnI and IL-6, HMGB1, GSK-3β and increase in IL-10 and p-GSK-3β in the blood in sepsis- subjected rats. The effects of telmisartan at dose 4 mg/kg and AR-A014418 at a dose of 2 mg/kg were significantly higher than the telmisartan at a dose of 2 mg/kg and AR-A014418 1 mg/kg respectively. Further, no significant effects on different parameters were observed in the sham control group in comparison to normal. Therefore it is plausible to suggest that sepsis may increase the levels of angiotensin II to trigger GSK-3β-dependent signaling to activate the HMGB1/receptors for advanced glycation end products, which may promote inflammation and myocardial injury in sepsis-subjected rats.

Protective effect of alpha-pinene against isoproterenol-induced myocardial infarction through NF-κB signaling pathway

Monoterpenes present in the essential oils exhibit anti-inflammatory properties. In this study, we investigated the preventive effect of alpha-pinene (AP), a monoterpene, against isoproterenol (ISO)-induced myocardial infarction and inflammation in Wistar rats. Male Wistar rats were pretreated with AP (50 mg/kg body weight (bw)) administration for 21 days and ISO (85 mg/kg bw) was administered subcutaneously for last two consecutive days (20th day and 21st day). We noticed that there was an increased activity of cardiac marker enzymes in ISO-treated rats. We also observed that elevated levels of lipid peroxidative indices decreased activities of antioxidant status in plasma, erythrocyte, and heart tissue in ISO-induced rats. Furthermore, ISO-treated rats showed an increase in the levels of inflammatory mediators like tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the serum. Besides, we confirmed the upregulated expression of TNF-α, IL-6, and nuclear factor kappa-light-chain-enhancer of activated B cells in ISO-induced rat heart tissue. Conversely, we found that AP pretreatment significantly decreased levels of cardiac markers like serum cardiac troponin T and cardiac troponin I, lipid peroxidative markers, and restored antioxidants status in ISO-treated rats. Besides, AP administration attenuated ISO-induced inflammatory marker expression. The present findings demonstrated that AP significantly protects the myocardium and exerts cardioprotective and anti-inflammatory effects in experimental rats.

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

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

Egr-1 functions as a master switch regulator of remote ischemic preconditioning-induced cardioprotection

Despite improved treatment options myocardial infarction (MI) is still a leading cause of mortality and morbidity worldwide. Remote ischemic preconditioning (RIPC) is a mechanistic process that reduces myocardial infarction size and protects against ischemia reperfusion (I/R) injury. The zinc finger transcription factor early growth response-1 (Egr-1) is integral to the biological response to I/R, as its upregulation mediates the increased expression of inflammatory and prothrombotic processes. We aimed to determine the association and/or role of Egr-1 expression with the molecular mechanisms controlling the cardioprotective effects of RIPC. This study used H9C2 cells in vitro and a rat model of cardiac ischemia reperfusion (I/R) injury. We silenced Egr-1 with DNAzyme (ED5) in vitro and in vivo, before three cycles of RIPC consisting of alternating 5 min hypoxia and normoxia in cells or hind-limb ligation and release in the rat, followed by hypoxic challenge in vitro and I/R injury in vivo. Post-procedure, ED5 administration led to a significant increase in infarct size compared to controls (65.90 ± 2.38% vs. 41.00 ± 2.83%, p < 0.0001) following administration prior to RIPC in vivo, concurrent with decreased plasma IL-6 levels (118.30 ± 4.30 pg/ml vs. 130.50 ± 1.29 pg/ml, p < 0.05), downregulation of the cardioprotective JAK-STAT pathway, and elevated myocardial endothelial dysfunction. In vitro, ED5 administration abrogated IL-6 mRNA expression in H9C2 cells subjected to RIPC (0.95 ± 0.20 vs. 6.08 ± 1.40-fold relative to the control group, p < 0.05), resulting in increase in apoptosis (4.76 ± 0.70% vs. 2.23 ± 0.34%, p < 0.05) and loss of mitochondrial membrane potential (0.57 ± 0.11% vs. 1.0 ± 0.14%-fold relative to control, p < 0.05) in recipient cells receiving preconditioned media from the DNAzyme treated donor cells. This study suggests that Egr-1 functions as a master regulator of remote preconditioning inducing a protective effect against myocardial I/R injury through IL-6-dependent JAK-STAT signaling.

Minocycline protects against myocardial ischemia/reperfusion injury in rats by upregulating MCPIP1 to inhibit NF-κB activation

Minocycline is a tetracycline antibiotic and has been shown to play a protective role in cerebral and myocardial ischemia/reperfusion (I/R). However, the underlying mechanism remains unclear. Herein, we investigated whether monocyte chemotactic protein-induced protein-1 (MCPIP1), a negative regulator of inflammation, was involved in the minocycline-induced cardioprotection in myocardial I/R in vivo and in vitro models. Myocardial ischemia was induced in rats by left anterior descending coronary artery occlusion for 1 h and followed by 48 h reperfusion. Minocycline was administered prior to ischemia (45 mg/kg, ip, BID, for 1 d) and over the course of reperfusion (22.5 mg/kg, ip, BID, for 2 d). Cardiac function and infarct sizes were assessed. Administration of minocycline significantly decreased the infarct size, alleviated myocardial cell damage, elevated left ventricle ejection fraction, and left ventricle fractional shortening following I/R injury along with significantly decreased pro-inflammatory cytokine IL-1β and monocyte chemoattractant protein-1 (MCP-1) levels in heart tissue. H9c2 cardiomyocytes were subjected to oxygen glucose deprivation (OGD) followed by reoxygenation (OGD/R). Pretreatment with minocycline (1-50 μmol/L) dose-dependently increased the cell viability and inhibited OGD/R-induced expression of MCP-1 and IL-6. Furthermore, minocycline dose-dependently inhibited nuclear translocation of NF-κB p65 in H9c2 cells subjected to OGD/R. In both the in vivo and in vitro models, minocycline significantly increased MCPIP1 protein expression; knockdown of MCPIP1 with siRNA in H9c2 cells abolished all the protective effects of minocycline against OGD/R-induced injury. Our results demonstrate that minocycline alleviates myocardial I/R injury via upregulating MCPIP1, then subsequently inhibiting NF-κB activation and pro-inflammatory cytokine secretion.

Protective effect of syringaldehyde on biomolecular oxidation, inflammation and histopathological alterations in isoproterenol induced cardiotoxicity in rats

BACKGROUND

Ischemic injury during myocardial infarction (MI) is responsible for increased deaths among patients with cardiovascular disorders. Recently, research has been directed for finding treatment using natural compounds. This study was performed to investigate the effects of syrigaldehyde (SYD), a phytochemical against isoproterenol (ISO) induced cardiotoxicity model.

METHODS

For induction of MI, rats were intoxicated with two doses of ISO and were treated with SYD at three different concentrations (12.5, 25 & 50 mg/kg) both prior and simultaneous to ISO administration.

RESULTS

ISO group revealed amplified activity of marker enzymes (CKMB, LDH, AST, ALT), increased oxidation of proteins and lipid molecules. Moreover, augmentation in pro-inflammatory markers was also found. The same group also displayed marked changes in histopathology and erythrocyte (RBCs) morphology. SYD treated groups showed diminished levels of serum markers enzymes, lipid peroxidation and protein carbonyl (PC) with increment in antioxidant defense in cardiac tissues of ISO administered rats. Our findings also revealed the modulatory effect of SYD on membrane bound ATPases, showing that SYD significantly improved the ISO induced changes in membrane fluidity. Furthermore, decline in infarct size, alleviation of structural RBC damage and improved myocardial histopathological outcome were observed in treated groups. In addition, mitigation of biochemical and histopathological changes by SYD was found to be dependent on its concentration.

CONCLUSION

SYD had cardioprotective efficacy owing to its antioxidative and anti-inflammatory properties. Our results support incorporation of SYD in regular diet for prevention of MI.

A Review on the Effect of Traditional Chinese Medicine Against Anthracycline-Induced Cardiac Toxicity

Anthracyclines are effective agents generally used to treat solid-tumor and hematologic malignancies. The use of anthracyclines for over 40 years has improved cancer survival statistics. Nevertheless, the clinical utility of anthracyclines is limited by its dose-dependent cardiotoxicity that adversely affects 10-30% of patients. Anthracycline-induced cardiotoxicity may be classified as acute/subacute or chronic/late toxicity and leads to devastating adverse effects resulting in poor quality of life, morbidity, and premature mortality. Traditional Chinese medicine has a history of over 2,000 years, involving both unique theories and substantial experience. Several studies have investigated the potential of natural products to decrease the cardiotoxic effects of chemotherapeutic agents on healthy cells, without negatively affecting their antineoplastic activity. This article discusses the mechanism of anthracycline-induced cardiotoxicity, and summarizes traditional Chinese medicine treatment for anthracycline-induced heart failure (HF), cardiac arrhythmia, cardiomyopathy, and myocardial ischemia in recent years, in order to provide a reference for the clinical prevention and treatment of cardiac toxicity.

Protective effect of Danhong Injection combined with Naoxintong Capsule on cerebral ischemia-reperfusion injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Danhong Injection (DHI) and Naoxintong Capsule (NXT) are renowned traditional Chinese medicine in China. The drug combination of DHI and NXT is frequently applied for the treatment of cardiovascular and cerebrovascular diseases in clinic. However, there had been no pharmacological experiment studies of interaction between DHI and NXT. Due to the drug interactions, exploring their interaction profile is of great importance.

MATERIAL AND METHODS

In this study, focal cerebral I/R injury in adult male Sprague-Dawley rats were induced by transient middle cerebral artery occlusion (tMCAO) for 1h followed by reperfusion. Rats were divided into 5 groups: sham group, ischemia reperfusion untreated group (IRU), DHI group (DHI 10mL/kg/d), NXT group (NXT 0.5g/kg/d), DHI plus NXT group (DHI-NXT, DHI 10mL/kg/d plus NXT 0.5g/kg/d). All drug-treated groups were respectively successive administrated for 7 days after ischemia/ reperfusion (I/R) injury. The effects on rat neurological function were estimated by neurological defect scores. Brain infarct volumes were determined based on 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Pathological changes in brain tissues were observed using hematoxylin and eosin (H&E) staining and transmission electron microscope (TEM). Levels of nitric oxide (NO), granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) in serum were determined with enzyme-linked immunosorbent assay (ELISA). Immunohisto-chemistry and Western blot were used to detect the expressions of basic fibroblast growth factor (bFGF), von Willebrand factor-microvessel vascular density (vWF-MVD), vascular endothelial cell growth factor (VEGF), transforming growth factor-β1 (TGF-β1), angiogenin-1 (Ang-1), angiogenin-2 (Ang-2) and platelet derived growth factor (PDGF) at day 7 after ischemia/reperfusion (I/R) injury.

RESULTS

Compared with IRU group and mono-therapy group (DHI group or NXT group), Danhong Injection combined with Naoxintong Capsule (DHI-NXT) group significantly ameliorated neurological deficits scores, infarct volume and pathological change, significantly decreased the overexpression of NO and the level of Ang-1, significantly increased the expressions of VEGF, Ang-2, G-CSF, GM-CSF, bFGF, PDGF, vWF, TGF-β1.

CONCLUSION

The protective benefits on rat brain against I/R injury were clearly produced when DHI and NXT were used in combination, which provided rational guidance for clinical combined application of DHI and NXT, and this protection maybe associated with the up-regulation expressions of the related chemokines and growth factors of angiogenesis.

Cardioprotective effect of nesfatin-1 against isoproterenol-induced myocardial infarction in rats: Role of the Akt/GSK-3β pathway

The present study was designed to evaluate the cardioprotective effects of nesfatin-1, a novel peptide with anorexigenic properties, in rats with isoproterenol (ISO)-induced myocardial infarction (MI), and to further investigate the role of Akt/GSK-3β signaling pathway in the protective effect of nesfatin-1. To induce MI, ISO was subcutaneously injected into the rats for two consecutive days at a dosage of 85mg/kg/day. ISO-induced myocardial damage was indicated by elevated levels of cardiac specific troponin-T, enhanced myocardial expression of proinflammatory cytokines (interleukin-1β, interleukin-6 and tumor necrosis factor-α), and increased number of cells with apoptotic and necrotic appearance in the myocardial tissue. Levels of p-Akt/Akt and p-GSK-3β/GSK-3β significantly decreased in heart tissue after ISO-induced MI. However, intraperitoneal administration of nesfatin-1 (10μg/kg/day) elicited a significant cardioprotective activity by lowering the levels of cardiac troponin-T and proinflammatory cytokines, indicating the protective effect of nesfatin-1 against ISO-induced MI. The biochemical findings were further confirmed by histopathological examination, which was demonstrated by reduced number of apoptotic and necrotic cells. Moreover, expressions of p-Akt/Akt and p-GSK-3β/GSK-3β in the myocardium of MI group rats were significantly increased by nesfatin-1 administration, suggesting that nesfatin-1, which appears to possess anti-apoptotic and anti-inflammatory properties, may confer protection against ISO-induced MI via an Akt/GSK-3β-dependent mechanism.

Vitexin attenuates acute doxorubicin cardiotoxicity in rats via the suppression of oxidative stress, inflammation and apoptosis and the activation of FOXO3a

Doxorubicin (DOX) is one of the most effective chemotherapeutic drugs. However, its clinical use has been hampered due to the development of cardiotoxicity. Vitexin, which is the active ingredient of hawthorn leaf extract, has various biological activities, including antioxidant and anti-inflammatory actions. The present study aimed to investigate whether vitexin was able to protect against DOX-induced acute cardiotoxicity in model rats and the mechanisms of this protective effect were assessed. Adult Sprague-Dawley rats were randomly assigned into the control (saline only), model (DOX only) and vitexin-treated (DOX plus vitexin) groups. Rats in the model and vitexin-treated groups were injected with DOX (2 mg/kg; i.p.) once a week for 4 weeks. Rats in the vitexin-treated group were administered 30 mg/kg oral vitexin once daily at doses for 4 weeks. The levels of lactate dehydrogenase, creatine kinase isoenzyme-MB, malondialdehyde, superoxide dismutase, catalase and myeloperoxidase were assessed using assay kits. The levels of inflammatory mediators, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, nuclear factor (NF)-κB, and caspase-3, were assayed by the enzyme-linked immunosorbent assay method. Western blot analysis was performed to assess the protein expression levels of p-FOXO3a. Vitexin pretreatment significantly protected against DOX-induced myocardial damage, which was characterized by increased serum creatine kinase isoenzyme-MB and lactate dehydrogenase. Vitexin significantly ameliorated oxidative stress injury evoked by DOX, demonstrated by the inhibition of lipid peroxidation and the elevation of antioxidant enzyme activities. Furthermore, DOX provoked inflammatory responses by increasing the expression levels of IL-1β, IL-6, NF-κB and tumor necrosis factor-α, whereas vitexin pretreatment significantly inhibited these inflammatory responses. Notably, DOX induced apoptotic tissue damage by increasing caspase-3 activity, whereas vitexin administration was able to decrease caspase-3 activity. In addition, vitexin induced elevated FOXO3a protein expression levels in the vitexin-treated group. In conclusion, the findings of the present study suggested that vitexin possesses cardioprotective action against DOX-induced cardiotoxicity by suppressing oxidative stress, inflammation and apoptotic signals.

Isoflurane reduces oxygen-glucose deprivation-induced oxidative, inflammatory, and apoptotic responses in H9c2 cardiomyocytes

Isoflurane (ISO) protects the heart from hypoxia-reperfusion injury. However, the molecular mechanisms of ISO in oxygen-glucose deprivation (OGD)-induced H9c2 cardiomyocyte injury is yet to be understood. Using H9c2 cells cultured in vitro, we examined the cytotoxicity of different doses of ISO (0.7%, 1.4%, and 2.1%) to H9c2 cells and found that 2.1% ISO had significant toxicity to the cell. Thus, 1.4% ISO was selected for the subsequent experiments. ISO notably ameliorated cell viability loss, lactate dehydrogenase release, and creatine kinase activity of H9c2 cells that were treated with OGD. ISO suppressed OGD-induced pro-inflammatory tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8 production, and nuclear factor (NF)-κB activation in H9c2 cells. ISO reduced the reactive oxygen species and malondialdehyde generation, but it enhanced the superoxide dismutase activity in OGD-stimulated H9c2 cells. In addition, diminished OGD-induced cell apoptosis and preserved mitochondrial membrane potential were observed in ISO-treated H9c2 cells. ISO markedly up-regulated the anti-apoptotic Bcl-2 expression but inhibited the pro-apoptotic expressions of Bax, procaspase-3, cleaved caspase-3, and caspase-3 activity. Mechanistically, the cardioprotective effects of ISO on OGD-induced H9c2 cell injury were mediated by the Akt signaling pathway. These findings suggest that ISO alleviates OGD-induced H9c2 cell injury and may therefore be used to prevent and treat ischemic heart diseases.

Stem cell impregnated nanofiber stent sleeve for on-stent production and intravascular delivery of paracrine factors

Stem cell therapies for atherosclerotic diseases are promising, but benefits remain modest with present cell delivery devices in part due to cell washout and immune attack. Many stem cell effects are believed mediated by paracrine factors (PFs) secreted by the stem cells which potentiate tissue repair via activation and enhancement of intrinsic host repair mechanisms We therefore sought to create an "intravascular paracrine factor factory" by harnessing stem cells on a stent using a nanofiber (NF) stent sleeve, and thus providing a sheltered milieu for cells to continuously produce PFs on-stent. The NF sleeve acts as a substrate on which stem cells grow, and as a semi-permeable barrier that protects cells from washout and host immune response while allowing free outward passage of PFs. NF stent sleeves were created by covering stents with electrospun poly-lactic-co-glycolic acid nanofibers and were then uniformly coated with mesenchymal stem cells (MSCs). NF sleeves blocked cell passage but did not hamper MSC attachment or proliferation, and did not alter MSC morphology or surface markers. NF sleeve MSCs continued to secrete PFs that were biologically active and successfully induced tubulogenesis in human endothelial cells. NF stent sleeves seeded with allogeneic MSCs implanted in pigs remained patent at 7 days without thrombotic occlusion or immune rejection. Our results demonstrate the feasibility of creating an intravascular PF factory using a stem cell impregnated NF stent sleeve, and pave the way for animal studies to assess the efficacy of local PF production to treat ischemic artery disease.

Thymol attenuates inflammation in isoproterenol induced myocardial infarcted rats by inhibiting the release of lysosomal enzymes and downregulating the expressions of proinflammatory cytokines

Inflammation plays an important role in the development of myocardial infarction (MI). The current study dealt with the protective effects of thymol on inflammation in isoproterenol (ISO) induced myocardial infarcted rats. Male albino Wistar rats were pre and co-treated with thymol (7.5mg/kg body weight) daily for 7 days. ISO (100mg/kg body weight) was injected subcutaneously into rats at an interval of 24h for two days (6th and 7th day) to induce MI. ISO induced myocardial infarcted rats showed increased levels of serum cardiac troponin-T, high sensitive C-reactive protein (hsCRP), lysosomal thiobarbituric acid reactive substances (TBARS) and elevated ST-segments. Also, the activities of lysosomal enzymes such as β-glucuronidase, β-galactosidase, cathepsin-B and D, the stimulators of inflammatory mediators were increased in the serum and heart of ISO induced myocardial infarcted rats. Furthermore, ISO up regulates the expressions of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) genes in the myocardium of rats analyzed by reverse transcription polymerase chain reaction (RT-PCR). Pre and co-treatment with thymol (7.5mg/kg body weight) near normalized the levels of lysosomal TBARS, activities of serum and heart lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines in the myocardium of ISO induced myocardial infarcted rats. Histopathological and transmission electron microscopic findings were also found in line with biochemical findings. Thus, the results of our study revealed that thymol attenuates inflammation by inhibiting the release of lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines by its potent anti-inflammatory effect.

Resolvin D1, a metabolite of omega-3 polyunsaturated fatty acid, decreases post-myocardial infarct depression

We hypothesized that inflammation induced by myocardial ischemia plays a central role in depression-like behavior after myocardial infarction (MI). Several experimental approaches that reduce inflammation also result in attenuation of depressive symptoms. We have demonstrated that Resolvin D1 (RvD1), a metabolite of omega-3 polyunsaturated fatty acids (PUFA) derived from docosahexaenoic acid, diminishes infarct size and neutrophil accumulation in the ischemic myocardium. The aim of this study is to determine if a single RvD1 injection could alleviate depressive symptoms in a rat model of MI. MI was induced in rats by occlusion of the left anterior descending coronary artery for 40 min. Five minutes before ischemia or after reperfusion, 0.1 μg of RvD1 or vehicle was injected in the left ventricle cavity. Fourteen days after MI, behavioral tests (forced swim test and socialization) were conducted to evaluate depression-like symptoms. RvD1 reduced infarct size in the treated vs. the vehicle group. Animals receiving RvD1 also showed better performance in the forced swim and social interaction tests vs. vehicle controls. These results indicate that a single RvD1 dose, given 5 min before occlusion or 5 min after the onset of reperfusion, decreases infarct size and attenuates depression-like symptoms.

The mechanisms of up-regulation of dendritic cell activity by oxidative stress

Whereas DC have increasingly been recognized for their role in activating the inflammatory cascades during IRIs, the mechanisms by which oxidative stress enhances DC activation remain to be explored. We examined the role of oxidative stress on two important features of DC: T cell activation and trafficking. Bone marrow-derived OS-DC were compared with untreated DC. DC exposed to oxidative stress augmented allogeneic T cell proliferation and showed increased migration in a chemotaxis chamber. These results were confirmed by using hypoxanthine and xanthine oxidase as another inducer of oxidative stress. We used OT-II and OT-I mice to assess the effect of oxidative stress on DC activation of OVA-specific CD4(+) and CD8(+) T cells, respectively. Oxidative stress increased DC capacity to promote OVA-specific CD4(+) T cell activity, demonstrated by an increase in their proliferation and production of IFN-γ, IL-6, and IL-2 proinflammatory cytokines. Whereas oxidative stress increased the DC ability to stimulate IFN-γ production by OVA-specific CD8(+) T cells, cellular proliferation and cytotoxicity were not affected. Compared with untreated DC, oxidative stress significantly reduced the capacity of DC to generate T(regs), which were restored by using anti-IL-6. With regard to DC trafficking, whereas oxidative stress increased DC expression of p-Akt and p-NF-κB, targeting PI3Kγ and NF-κB pathways abrogated the observed increase in DC migration. Our data propose novel insights on the activation of DC by oxidative stress and provide rationales for targeted therapies, which can potentially attenuate IRI.

Association between peak neutrophil count, clopidogrel loading dose, and left ventricular systolic function in patients with primary percutaneous coronary intervention

Inflammation plays an important role in plaque development and left ventricular remodeling during acute myocardial infarction (AMI). Clopidogrel may exhibit some anti-inflammatory properties and high loading dose of clopidogrel results in improved clinical outcomes in patients with AMI. 357 patients who received successful primary percutaneous coronary intervention from January 2008 to March 2011 in Peking University Third Hospital were included in this study. Different loading dose of clopidogrel (300 mg, 450 mg, or 600 mg) was given at the discretion of the clinician. Neutrophils reached their peak values on the first day after AMI. Higher levels of peak neutrophil and lower left ventricular ejection fraction (LVEF) were found in patients of low clopidogrel loading dose group (300 mg or 450 mg). After adjusting for the related confounders, a logistic regression model showed that low clopidogrel loading dose remained an independent predictor of low LVEF (LVEF ≤ 50%) [OR: 1.97, 95% CI: 1.03–3.79, P = 0.04]. Low clopidogrel loading dose was associated with higher peak neutrophil count and poor left ventricular systolic function, suggesting an important role of clopidogrel loading dose in the improvement of left ventricular function and high loading dose may exhibit better anti-inflammatory properties.

Effects of Thyroid Hormone Analogue and a Leukotrienes Pathway-Blocker on Reperfusion Injury Attenuation after Heart Transplantation

Background. Global myocardial ischemia reperfusion injury after heart transplantation is believed to impair graft function and aggravate both acute and chronic rejection episodes. Objectives. To assess the possible protective potential of MK-886 and 3,5-diiodothyropropionic acid DITPA against global myocardial ischemia reperfusion injury after heart transplantation. Materials and Methods. Adult albino rats were randomized into 6 groups as follows: group I sham group; group II, control group; groups III and IV, control vehicles (1,2); group V, MK-886 treated group. Donor rats received MK-886 30 min before transplantation, and the same dose was repeated for recipients upon reperfusion; in group VI, DITPA treated group, donors and recipients rats were pretreated with DITPA for 7 days before transplantation. Results. Both MK-886 and DITPA significantly counteract the increase in the levels of cardiac TNF-α, IL-1β, and ICAM-1 and plasma level of cTnI (P < 0.05). Morphologic analysis showed that both MK-886 and DITPA markedly improved (P < 0.05) the severity of cardiac injury in the heterotopically transplanted rats. Conclusions. The results of our study reveal that both MK-886 and DITPA may ameliorate global myocardial ischemia reperfusion injury after heart transplantation via interfering with inflammatory pathway.

Macrophages modulate the viability and growth of human mesenchymal stem cells

Following myocardial infarction, tissue repair is mediated by the recruitment of monocytes and their subsequent differentiation into macrophages. Recent findings have revealed the dynamic changes in the presence of polarized macrophages with pro-inflammatory (M1) and anti-inflammatory (M2) properties during the early (acute) and late (chronic) stages of cardiac ischemia. Mesenchymal stem cells (MSCs) delivered into the injured myocardium as reparative cells are subjected to the effects of polarized macrophages and the inflammatory milieu. The present study investigated how cytokines and polarized macrophages associated with pro-inflammatory (M1) and anti-inflammatory (M2) responses affect the survival of MSCs. Human MSCs were studied using an in vitro platform with individual and combined M1 and M2 cytokines: IL-1β, IL-6, TNF-α, and IFN-γ (for M1), and IL-10, TGF-β1, TGF-β3, and VEGF (for M2). In addition, polarization molecules (M1: LPS and IFN-γ; M2: IL-4 and IL-13) and common chemokines (SDF-1 and MCP-1) found during inflammation were also studied. Indirect and direct co-cultures were conducted using M1 and M2 polarized human THP-1 monocytes. M2 macrophages and their associated cytokines supported the growth of hMSCs, while M1 macrophages and their associated cytokines inhibited the growth of hMSCs in vitro under certain conditions. These data imply that an anti-inflammatory (M2) environment is more accommodating to the therapeutic hMSCs than a pro-inflammatory (M1) environment at specific concentrations.

Secreted frizzled-related protein-1 improves postinfarction scar formation through a modulation of inflammatory response

OBJECTIVE

The inflammatory response after myocardial infarction plays a crucial role in the healing process. Lately, there is accumulating evidence that the Wnt/Frizzled pathway may play a distinct role in inflammation. We have shown that secreted frizzled-related protein-1 (sFRP-1) overexpression reduced postinfarction scar size, and we noticed a decrease in neutrophil infiltration in the ischemic tissue. We aimed to further elucidate the role of sFRP-1 in the postischemic inflammatory process.

METHODS AND RESULTS

We found that in vitro, sFRP-1 was able to block leukocyte activation and cytokine production. We transplanted bone marrow cells (BMCs) from transgenic mice overexpressing sFRP-1 into wild-type recipient mice and compared myocardial healing with that of mice transplanted with wild-type BMCs. These results were compared with those obtained in transgenic mice overexpressing sFRP-1 specifically in endothelial cells or in cardiomyocytes to better understand the spatiotemporal mechanism of the sFRP-1 effect. Our findings indicate that when overexpressed in the BMCs, but not in endothelial cells or cardiomyocytes, sFRP-1 was able to reduce neutrophil infiltration after ischemia, by switching the balance of pro- and antiinflammatory cytokine expression, leading to a reduction in scar formation and better cardiac hemodynamic parameters.

CONCLUSION

sFRP-1 impaired the loop of cytokine amplification and decreased neutrophil activation and recruitment into the scar, without altering the neutrophil properties. These data support the notion that sFRP-1 may be a novel antiinflammatory factor protecting the heart from damage after myocardial infarction.

Pharmacodynamics of ellagic acid on cardiac troponin-T, lyosomal enzymes and membrane bound ATPases: mechanistic clues from biochemical, cytokine and in vitro studies

The anti lipid peroxidative and antioxidant effects of ellagic acid against isoproterenol-induced myocardial infarcted rats were reported previously. This study was designed to evaluate the protective effects of ellagic acid on the levels of cardiac troponin-T, lysosomal enzymes, and membrane bound ATPases along with the role of pro inflammatory cytokine. Male albino Wistar rats were pretreated with ellagic acid (7.5 and 15 mg/kg body weight) daily for a period of 10 days. After the pretreatment period isoproterenol (100mg/kg) was subcutaneously injected to rats twice at an interval of 24h. The protective effects of pretreatment with ellagic acid were measured by biochemical analysis and reverse transcriptase polymerase chain reaction. Evidence of myocardial infarction in isoproterenol induced rats included significant increase in the serum level of cardiac troponin-T and decreased levels of creatine kinase and lactate dehydrogenase in heart tissue homogenate .The pretreatment with ellagic acid restored the levels of cardiac markers in the serum and heart tissue homogenates. The activities of lysosomal enzymes (β-d-glucuronidase, β-N-acetyl glucosaminidase, β-galactosidase, cathepsin-d and acid phosphatase) were increased significantly in the serum and heart tissue of isoproterenol-induced rats. The activity of Na(+)/K(+)ATPase declined while the activities of Ca(2+)ATPase and Mg(2+)ATPase were increased significantly in the heart of isoproterenol-induced rats. Pretreatment with ellagic acid restored the activities of lysosomal enzymes and membrane bound ATPases. The higher expressions of pro-inflammatory cytokines such as interleukin-1β, interleukin-6 and tumour necrosis factor-α in the isoproterenol-induced rats were controlled by the pretreatment with ellagic acid. Our results imply that oral pretreatment with ellagic acid protects the heart lysosomal membrane against isoproterenol-induced cardiac damage. The observed effects might be due to the free radical scavenging, membrane stabilizing and anti-inflammatory properties of ellagic acid.

The cardiokine story unfolds: ischemic stress-induced protein secretion in the heart

Intercellular communication depends on many factors, including proteins released via the classical or non-classical secretory pathways, many of which must be properly folded to be functional. Owing to their adverse effects on the secretion machinery, stresses such as ischemia can impair the folding of secreted proteins. Paradoxically, cells rely on secreted proteins to mount a response designed to resist stress-induced damage. This review examines this paradox using proteins secreted from the heart, cardiokines, as examples, and focuses on how the ischemic heart maintains or even increases the release of select cardiokines that regulate important cellular processes in the heart, including excitation-contraction coupling, hypertrophic growth, myocardial remodeling and stem cell function, in ways that moderate ischemic damage and enhance cardiac repair.

Olprinone, a PDE3 inhibitor, modulates the inflammation associated with myocardial ischemia-reperfusion injury in rats

Coronary ischemia and subsequent reperfusion result in deleterious effects, one of the principal ones being vascular and myocardial inflammation. Olprinone hydrochloride, a specific phosphodiesterase III inhibitor, has anti-inflammatory effects in addition to its inotropic and vasodilator effects. The purpose of this study was to examine the beneficial effects of olprinone on myocardial ischemia-reperfusion injury. Myocardial ischemia-reperfusion injury was caused by clamping the LAD (left anterior descending) coronary artery for 25 min followed by a release of the clamp allowing reperfusion for 1 h. Olprinone i.p. (0.2 mg/kg, i.p.) was administrated 15 min after ischemia. The olprinone administration significantly reduced the: (1) histological evidence of myocardial injury, (2) pro-inflammatory cytokines: tumor necrosis factor-α (TNF-α) and Interleukin-1β (IL-1β), (3) adhesion molecules: Inter-Cellular Adhesion Molecule 1 (ICAM-1) and P-Selectin, (4) nitrotyrosine formation, (5) nuclear factor kappa-B (NF-κB) expression, (6) Poly (ADP-ribose) (PAR) formation, and (7) apoptosis (Bax, Bcl-2, Fas-L and terminal deoxynucleotidyl transferase-mediated UTP end labeling (TUNEL). Based on these findings this study provides the evidence that treatment with olprinone ameliorated the inflammatory process associated with myocardial ischemia-reperfusion in rats and suggests that this drug may have potential in the treatment of various ischemia and reperfusion diseases.

Clinical implications of cytokines in the critical-care unit

To understand the role of different cytokines in the pathophysiology and management of different acute cardiovascular disorders in critically ill patients, we reviewed most of the pertinent articles published on Medline, Scopus and EBSCO host research databases from 1985 to January 2009. We used the indexing terms 'cytokines', 'cardiovascular', 'sepsis', 'critical care', 'myocardial dysfunction', 'shock', 'thromboembolism', 'inflammatory' and 'arrhythmias'. Myocardial dysfunction, dysrhythmic and thromboembolic disorders all appear associated with important fluctuations in cytokines. When and how to sample cytokine levels and the ways in which cytokines contribute to patient deterioration or improvement require further clinical studies. The measurement and interplay of several different cytokines may ultimately be of substantial clinical importance in the diagnosis, treatment and prognosis of patients with different acute cardiovascular disorders managed by critical-care physicians in intensive-care units. Although the role of cytokines in cardiovascular disorders is debatable, the clinical implication of cytokines in the critical-care unit is a new horizon that warrants more attention.

Activated protein C: a potential cardioprotective factor against ischemic injury during ischemia/reperfusion

Activated protein C (APC) is a vitamin-K dependent natural anticoagulant protein. With its function in blood clotting reaction, APC can reduce the risk of venous thrombosis to prevent ischemic disease. A number of in vivo and in vitro studies over the past few decades have revealed that APC also exerted cytoprotective effects to decrease the mortality caused by endotoxin, sepsis, and brain ischemic stroke. The direct cytoprotective role requires APC binding to the endothelial protein C receptor (EPCR) and activating protease activated receptor-1 (PAR-1). It is now believed that the beneficial characters of APC are partially independent from its anticoagulant activity, though more studies need to be done to demonstrate the exact molecular mechanism. In this review, we have linked the cytoprotective effects of APC including the anti-inflammatory and anti-apoptosis activities to myocardial ischemic injury caused by cardiac ischemia reperfusion. Specifically, we have tried to combine the potential signaling pathways initiated by APC with the well-known adaptive signaling such as AMP-activated protein kinase (AMPK), PI3K/Akt and ERK/MAPK pathways that contribute to the cardioprotection against myocardial ischemia injury. We speculate that APC protects against cardiac ischemia injury via triggering crucial cardioprotective signaling pathways, and these effects are mostly associated with its cytoprotective activity but independent on its anticoagulant activity.

Cytokines and myocardial dysfunction: state of the art

BACKGROUND

Myocardial dysfunction has been associated with inflammation and cytokine modulation.

OBJECTIVES

The study objective was to understand the role of cytokines in the pathophysiology and management of myocardial dysfunction.

METHODS

Heart failure has been revisited with revision of the pertinent published articles in the Medline, Scopus, Cochrane Database of Systematic Reviews, and EBSCO Host research.

RESULTS

For the proinflammatory cytokines, illumination of this important point requires further diagnostic and therapeutic investigations. Data on chronic heart failure are not so reassuring; therefore, patients with advanced heart failure should not be treated with anticytokines at this time.

CONCLUSION

Further studies are warranted to pave the way for introducing cytokine and immunomodulation therapy at the optimal and appropriate time.

Mitochondrial function in cardiomyocytes: target for cardioprotection

PURPOSE OF REVIEW

Cardiac diseases including ischemic heart disease, cardiomyopathy, hypertension, atherosclerosis and congestive heart failure are associated with cardiac cell death as a result of both necrosis and apoptosis. Mitochondria play an essential role in deciding whether a cell lives or dies. This review summarizes current knowledge on the mechanisms by which mitochondria exert such decision-making power.

RECENT FINDINGS

A wide variety of factors, either directly or indirectly, function in a synchronized manner to regulate the death versus survival signals. Mitochondrial bioenergetics and permeability transition pore plays a crucial role in this process, although several redox-sensitive genes, proteins and transcription factors, such as Bcl-2, Bax, nuclear factor kappa B, regulate the decision-making power of mitochondria, which have the final authority to decide whether a cell lives or dies. Mitochondrially generated reactive oxygen species are critically involved in the decision-making process, by functioning both as executioner by damaging the biomolecules, or as savior by virtue of their ability to perform redox signaling.

SUMMARY

It appears that mitochondria regulate the life and death of cardiac cells by manipulating several factors, including bioenergetics, mitochondrial permeability transition pore and redox-sensing genes. Redox signaling is likely to be critically involved in this process.

Preconditioning potentiates redox signaling and converts death signal into survival signal

Reactive oxygen species (ROS) play a crucial role in the pathophysiology of ischemic heart disease by causing cardiac dysfunction and cell death. Several redox-sensitive anti- and pro-apoptotic transcription factors including NFkappaB and AP-1 progressively and steadily increase in the heart as a function of the duration of ischemia and reperfusion. When the heart is preconditioned to ischemic stress by repeated short-term ischemia and reperfusion, NFkappaB remains high while AP-1 is lowered to almost baseline value. The anti-apoptotic gene Bcl-2 is downregulated in the ischemic/reperfused heart, while it is upregulated in the adapted myocardium. Cardioprotective abilities of the preconditioning are abolished when heart is pre-perfused with N-acetyl cysteine, a scavenger for ROS, suggesting the role of ROS in redox signaling. Mammalian heart is protected by several defense systems which include among others, redox-regulated protein, thioredoxin. Reperfusion of ischemic myocardium results in the downregulation of thioredoxin 1 (Trx 1) expression, which was upregulated in the preconditioned myocardium. The increased expression of Trx 1 is completely blocked with an inhibitor of Trx 1, CDDP, which also abolished cardioprotection afforded by ischemic adaptation. The cardioprotective role of Trx 1 is confirmed further with transgenic mouse hearts overexpressing Trx 1. The Trx 1 mouse hearts displayed significantly improved post-ischemic ventricular recovery and reduced myocardial infarct size and apoptosis as compared to the corresponding wild-type mouse hearts. Taken together, preconditioning appears to potentiate redox signaling, which converts the "death signal" into "survival signal."

Chemokine expression in myocardial ischemia: MIP-2 dependent MCP-1 expression protects cardiomyocytes from cell death

Chemokines are small molecular weight proteins that play important roles in inflammation. Originally described as chemotactic cytokines, chemokines stimulate the influx of leukocytes into specific tissue compartments. These molecules also modulate gene expression in both infiltrating and resident cells to mediate a vast array of cellular functions, and their importance in disease processes has been well documented. This study examined the expression of chemokines during myocardial ischemia and established a pathway by which two, MIP-2 and JE/MCP-1, modulate cardiac myocyte viability during this process. To focus on the direct effects of chemokines on these cells, a mouse model of ischemia without reperfusion was used. The expression of chemokines and chemokine receptors was induced in the left ventricular free wall as early as 1 h post-ischemia, with the most significant increases in MIP-2 (CXCL2) and JE/MCP-1 (CCL2). Expression of their respective receptors, CXCR2 and CCR2, was also induced. Similar changes in gene expression occurred at the mRNA and protein levels in isolated neonatal mouse cardiac myocytes stimulated by hypoxia. Antibody to MIP-2 inhibited hypoxia-induced JE/MCP-1 expression, demonstrating that MIP-2 is critical for this event. Moreover, in vivo intramyocardial injection of either an adenovirus expressing MIP-2 or the recombinant protein itself was sufficient to upregulate JE/MCP-1 production even in the absence of ischemia. Thus, MIP-2 regulates JE/MCP-1 expression both in cell culture and in vivo. Furthermore, JE/MCP-1 markedly decreased hypoxia-induced cell death in cultured cardiac myocytes. Thus, JE/MCP-1 appears to mediate an unanticipated survival pathway in target cardiac myocytes themselves. These findings indicate an important role for MIP-2 and JE/MCP-1 in regulating the response of cardiac myocytes to myocardial ischemia.

Redox regulation of cardiomyocyte survival and death

In this review, attempts were made to establish the role of reactive oxygen species as signaling molecules that regulate cardiomyocyte life and death during ischemia and reperfusion. Ischemia/reperfusion is a classical example because partial or mild ischemia can lead to simultaneous execution and repair of the cardiomyocytes, which is disrupted during severe ischemia leading to cell necrosis because of the lack of ATP. Apoptosis and repair processes are mediated by adaptive response in which oxygen free radicals function as typical signaling molecules through the activation of receptor tyrosine kinases, protein kinase C, and mitogen-activated protein kinases, as well as induction of redox-sensitive transcription factors and genes.