N-Acetylcysteine effects on transforming growth factor-β and tumor necrosis factor-α serum levels as pro-fibrotic and inflammatory biomarkers in patients following ST-segment elevation myocardial infarction

Cellular and molecular mechanisms driving cardiac tissue fibrosis: On the precipice of personalized and precision medicine

Cardiac fibrosis is a significant contributor to heart failure, a condition that continues to affect a growing number of patients worldwide. Various cardiovascular comorbidities can exacerbate cardiac fibrosis. While fibroblasts are believed to be the primary cell type underlying fibrosis, recent and emerging data suggest that other cell types can also potentiate or expedite fibrotic processes. Over the past few decades, clinicians have developed therapeutics that can blunt the development and progression of cardiac fibrosis. While these strategies have yielded positive results, overall clinical outcomes for patients suffering from heart failure continue to be dire. Herein, we overview the molecular and cellular mechanisms underlying cardiac tissue fibrosis. To do so, we establish the known mechanisms that drive fibrosis in the heart, outline the diagnostic tools available, and summarize the treatment options used in contemporary clinical practice. Finally, we underscore the critical role the immune microenvironment plays in the pathogenesis of cardiac fibrosis.

The Role of Pro-Inflammatory Cytokines in the Pathogenesis of Cardiovascular Disease

With cardiovascular disease (CVD) being a primary source of global morbidity and mortality, it is crucial that we understand the molecular pathophysiological mechanisms at play. Recently, numerous pro-inflammatory cytokines have been linked to several different CVDs, which are now often considered an adversely pro-inflammatory state. These cytokines most notably include interleukin-6 (IL-6),tumor necrosis factor (TNF)α, and the interleukin-1 (IL-1) family, amongst others. Not only does inflammation have intricate and complex interactions with pathophysiological processes such as oxidative stress and calcium mishandling, but it also plays a role in the balance between tissue repair and destruction. In this regard, pre-clinical and clinical evidence has clearly demonstrated the involvement and dynamic nature of pro-inflammatory cytokines in many heart conditions; however, the clinical utility of the findings so far remains unclear. Whether these cytokines can serve as markers or risk predictors of disease states or act as potential therapeutic targets, further extensive research is needed to fully understand the complex network of interactions that these molecules encompass in the context of heart disease. This review will highlight the significant advances in our understanding of the contributions of pro-inflammatory cytokines in CVDs, including ischemic heart disease (atherosclerosis, thrombosis, acute myocardial infarction, and ischemia-reperfusion injury), cardiac remodeling (hypertension, cardiac hypertrophy, cardiac fibrosis, cardiac apoptosis, and heart failure), different cardiomyopathies as well as ventricular arrhythmias and atrial fibrillation. In addition, this article is focused on discussing the shortcomings in both pathological and therapeutic aspects of pro-inflammatory cytokines in CVD that still need to be addressed by future studies.

N-acetylcysteine ameliorates erectile dysfunction in rats with hyperlipidemia by inhibiting oxidative stress and corpus cavernosum smooth muscle cells phenotypic modulation

Hyperlipidemia is a major risk factor for erectile dysfunction (ED). Oxidative stress and phenotypic modulation of corpus cavernosum smooth muscle cells (CCSMCs) are the key pathological factors of ED. N-acetylcysteine (NAC) can inhibit oxidative stress; however, whether NAC can alleviate pathological variations in the corpus cavernosum and promote erectile function recovery in hyperlipidemic rats remains unclear. A hyperlipidemia model was established using 27 eight-week-old male Sprague-Dawley (SD) rats fed a high-fat and high-cholesterol diet (hyperlipidemic rats, HR). In addition, 9 male SD rats were fed a normal diet to serve as controls (NC). HR rats were divided into three groups: HR, HR+normal saline (NS), and HR+NAC (n = 9 for each group; NS or NAC intraperitoneal injections were administered daily for 16 weeks). Subsequently, the lipid profiles, erectile function, oxidative stress, phenotypic modulation markers of CCSMCs, and tissue histology were analyzed. The experimental results revealed that erectile function was significantly impaired in the HR and HR + NS groups, but enhanced in the HR + NAC group. Abnormal lipid levels, over-activated oxidative stress, and multi-organ lesions observed in the HR and HR + NS groups were improved in the HR + NAC group. Moreover, the HR group showed significant phenotypic modulation of CCSMCs, which was also inhibited by NAC treatment. This report focuses on the therapeutic effect of NAC in restoring erectile function using a hyperlipidemic rat model by preventing CCSMC phenotypic modulation and attenuating oxidative stress.

N-acetylcysteine protects human periodontal ligament fibroblasts from pyroptosis and osteogenic differentiation dysfunction through the SIRT1/NF-κB/Caspase-1 signaling pathway

OBJECTIVE

This study was aimed to determine whether N-acetylcysteine (NAC) could inhibit lipopolysaccharides / adenosine triphosphate (ATP)-induced pyroptosis and alleviate the damage of osteogenic differentiation in human periodontal ligament fibroblasts (hPDLFs). Furthermore, this study detected whether NAC acted effectively by modulating the silent information regulator 2 homolog 1 (SIRT1)/ the nuclear factor-κB (NF-κB)/Caspase-1 signaling pathway in hPDLFs.

DESIGN

Cell Counting Kit-8 assay was employed to determine the appropriate concentration of NAC for the follow-up experiments. To explore the effect and the underlying mechanisms of NAC on pyroptosis and osteogenic differentiation in hPDLFs, intracellular reactive oxygen species levels were detected using 2',7'-Dichlorodihydrofluorescein Diacetate kits. Moreover, SIRT1 inhibitor, SIRT1 activator, NF-κB inhibitor and Caspase-1 inhibitor were applied, the incidence of pyroptosis was detected by flow cytometry, the osteogenic differentiation of hPDLFs was observed using alkaline phosphatase and alizarin red staining, Real-time quantitative polymerase chain reaction and Western Blot were used to detect the expression of relevant factors, the release of interleukin-1β, interleukin-18 and lactate dehydrogenase were detected by Enzyme-linked immunosorbent assay.

RESULTS

The results demonstrated that NAC protected hPDLFs from lipopolysaccharides/ATP-induced damage, alleviating pyroptosis and osteogenic differentiation dysfunction. Moreover, NAC abrogated the inhibition of SIRT1 activity by scavenging reactive oxygen species, thereby reduced pyroptosis and osteogenic differentiation dysfunction by inhibiting the NF-κB/Caspase-1signaling pathway.

CONCLUSION

NAC could inhibit pyroptosis and osteogenic differentiation dysfunction of hPDLFs by scavenging reactive oxygen species to regulate the SIRT1/NF-κB/Caspase-1 signaling axis.

The Value of Serum YKL-40 and TNF-α in the Diagnosis of Acute ST-Segment Elevation Myocardial Infarction

Background

Acute ST-segment elevation myocardial infarction (STEMI) is a serious cardiovascular disease that poses a great threat to the life and health of patients. Therefore, early diagnosis is important for STEMI patient treatment and prognosis. The purpose of this study was to investigate the value of serum YKL-40 and TNF-α in the diagnosis of STEMI.

Methods

From October 2020 to February 2022, 120 patients with STEMI were admitted to the Chest Pain Center of the Second People's Hospital of Hefei, and 81 patients with negative coronary angiography were selected as the control group. Serum YKL-40 and TNF-α concentrations were measured by sandwich ELISA. Pearson correlation was used to analyze the correlation between serum YKL-40, TNF-α, and serum troponin I (cTnI) in STEMI patients; multivariate logistic regression analysis was used to screen independent risk factors for STEMI. Three diagnostic models were constructed: cTnI univariate model (model A), combined serum YKL-40 and TNF-α model other than cTnI (model B), and combined cTnI and serum YKL-40 and TNF-α model (model C). We assessed the clinical usefulness of the diagnostic model by comparing AUC with decision curve analysis (DCA).

Results

Serum YKL-40 and TNF-α in the STEMI group were significantly higher than those in the control group (P < 0.001). On Pearson correlation analysis, there was a significant positive correlation between serum YKL-40, TNF-α, and cTnI levels in STEMI patients. Multivariate logistic regression analysis showed that serum YKL-40 and TNF-α were independent risk factors for the development of STEMI. The results of ROC analysis showed that the area under the curve (AUC) of serum YKL-40 for predicting the occurrence of STEMI was 0.704. The AUC of serum TNF-α for predicting the occurrence of STEMI was 0.852. The AUC of cTnI as a traditional model, model A, for predicting the occurrence of STEMI was 0.875. Model B predicted STEMI with an AUC of 0.851. The addition of serum YKL-40 and serum TNF-α to the traditional diagnostic model composed of cTnI constituted a new diagnostic model; that is, the AUC of model C for predicting the occurrence of STEMI was 0.930. Model C had a better net benefit between a threshold probability of 70–95% for DCA.

Conclusion

In this study, we demonstrate the utility of serum YKL-40 and TNF-α as diagnostic markers for STEMI and the clinical utility of diagnostic models by combining serum YKL-40 and TNF-α with cTnI.

Reduction of Activin Receptor-Like Kinase 4 Expression Ameliorates Myocardial Ischemia/Reperfusion Injury through Inhibiting TGFβ Signaling Pathway

The activation of activin receptor-like kinase 4 (ALK4) signaling plays a pivotal role in the pressure-overloaded heart, and haplodeficiency of ALK4 can alleviate cardiac fibrosis secondary to myocardial infarction and preserve cardiac function through partially inactivating the Smad3/4 pathway. However, whether transforming growth factor (TGF) β signaling is involved in the beneficial effects of ALK4 knockdown on the ischemic heart is still unclear. This study was undertaken to investigate the change in the TGFβ signaling after ALK4 knockdown in vivo and in vitro. Forty C57BL/6J mice were randomized into ALK4^+/- ischemia/reperfusion (I/R) group (ALK4^+/-+I/R, n = 10), ALK4^+/- sham group (ALK4^+/-+sham, n = 10), wild-type sham group (WT+sham, n = 10), and WT I/R group (WT+I/R, n = 10). Heart histology and the levels of cytokines related to antioxidant and inflammation, as well as protein and mRNA expressions of molecules associated with TGFβ pathway, were examined in different groups. Our results showed that the reduction of ALK4 expression ameliorated myocardial I/R injury through inhibiting TGFβ signaling pathway. Our findings indicate that ALK4 may become a novel target for the therapy of myocardial I/R injury.

At the Intersection of Cardiology and Oncology: TGFβ as a Clinically Translatable Therapy for TNBC Treatment and as a Major Regulator of Post-Chemotherapy Cardiomyopathy

Simple Summary

Specific/targeted therapies have been shown to be effective in the treatment of certain cancers. Unfortunately, there is currently no targeted therapy for the treatment of triple-negative breast cancer (TNBC), which is why this subtype of breast cancer is associated with poor patient prognosis. While there is an immense focus on the development of new therapies, the issue of cardiotoxicity following chemotherapeutic treatment is commonly overlooked, despite its role as a leading cause of mortality in cancer survivors. This review aims to discuss the connection of TGF-β signaling and its role in modulating cardiac fibrosis and remodeling, as well as its role in TNBC tumor progression, cancer stem cell enrichment, chemoresistance and relapse. Together, we highlight the modulation of TGF-β as a method to target two of the greatest causes of morbidity and mortality in breast cancer patients.

Abstract

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that accounts for the majority of breast cancer-related deaths due to the lack of specific targets for effective treatments. While there is immense focus on the development of novel therapies for TNBC treatment, a persistent and critical issue is the rate of heart failure and cardiomyopathy, which is a leading cause of mortality and morbidity amongst cancer survivors. In this review, we highlight mechanisms of post-chemotherapeutic cardiotoxicity exposure, evaluate how this is assessed clinically and highlight the transforming growth factor-beta family (TGF-β) pathway and its significance as a mediator of cardiomyopathy. We also highlight recent findings demonstrating TGF-β inhibition as a potent method to prevent cardiac remodeling, fibrosis and cardiomyopathy. We describe how dysregulation of the TGF-β pathway is associated with negative patient outcomes across 32 types of cancer, including TNBC. We then highlight how TGF-β modulation may be a potent method to target mesenchymal (CD44⁺/CD24⁻) and epithelial (ALDH^high) cancer stem cell (CSC) populations in TNBC models. CSCs are associated with tumorigenesis, metastasis, relapse, resistance and diminished patient prognosis; however, due to plasticity and differential regulation, these populations remain difficult to target and continue to present a major barrier to successful therapy. TGF-β inhibition represents an intersection of two fields: cardiology and oncology. Through the inhibition of cardiomyopathy, cardiac damage and heart failure may be prevented, and through CSC targeting, patient prognoses may be improved. Together, both approaches, if successfully implemented, would target the two greatest causes of cancer-related morbidity in patients and potentially lead to a breakthrough therapy.

Signaling pathways and targeted therapy for myocardial infarction

Although the treatment of myocardial infarction (MI) has improved considerably, it is still a worldwide disease with high morbidity and high mortality. Whilst there is still a long way to go for discovering ideal treatments, therapeutic strategies committed to cardioprotection and cardiac repair following cardiac ischemia are emerging. Evidence of pathological characteristics in MI illustrates cell signaling pathways that participate in the survival, proliferation, apoptosis, autophagy of cardiomyocytes, endothelial cells, fibroblasts, monocytes, and stem cells. These signaling pathways include the key players in inflammation response, e.g., NLRP3/caspase-1 and TLR4/MyD88/NF-κB; the crucial mediators in oxidative stress and apoptosis, for instance, Notch, Hippo/YAP, RhoA/ROCK, Nrf2/HO-1, and Sonic hedgehog; the controller of myocardial fibrosis such as TGF-β/SMADs and Wnt/β-catenin; and the main regulator of angiogenesis, PI3K/Akt, MAPK, JAK/STAT, Sonic hedgehog, etc. Since signaling pathways play an important role in administering the process of MI, aiming at targeting these aberrant signaling pathways and improving the pathological manifestations in MI is indispensable and promising. Hence, drug therapy, gene therapy, protein therapy, cell therapy, and exosome therapy have been emerging and are known as novel therapies. In this review, we summarize the therapeutic strategies for MI by regulating these associated pathways, which contribute to inhibiting cardiomyocytes death, attenuating inflammation, enhancing angiogenesis, etc. so as to repair and re-functionalize damaged hearts.

Immunomodulatory and anti-inflammatory effects of N-acetylcysteine in ovalbumin-sensitized rats

Background

Pro-inflammatory cytokines such as interleukin-5 (IL-5) and tumor necrosis factor-alpha (TNF-α) as well as immunoglobulin-E (IgE) appear to play a role in asthma. N-acetylcysteine (NAC), an antioxidant, might have clinical benefits in asthma prevention. The possible preventive effects of NAC against experimentally induced asthma in rats are investigated. The rats were allocated into five groups: a normal control, asthma control, a standard dexamethasone (DEXA, 1 mg/kg, orally) group, and two NAC groups (300 and 500 mg/kg, orally, respectively). Ovalbumin (OVA) sensitization was used to trigger asthma, which was then followed by an intra-nasal challenge. Test gents were administrated for 14 days before the challenge and during the three challenge days (20, 21, and 22). The tidal volume (TV) and peak expiratory flow rate (PEFR) as respiratory functions were determined. The pro-inflammatory cytokines as IL-5 and TNF-α were evaluated in lung homogenate. Serum IgE and absolute eosinophil count (AEC) in bronchoalveolar lavage fluid (BALF) were measured. In addition, the oxidative markers in lung tissue and nitrosative marker in BALF were assessed; finally, lungs were isolated for histopathological study.

Results

NAC restored lung functions, inhibited the asthma-dependent increase in TNF-α, IL-5, IgE, AEC, nitric oxide, and malondialdehyde levels. NAC further re-established lung glutathione content and superoxide dismutase activity, resulting in milder overall lung pathology.

Conclusions

Experimental bronchial asthma may be protected by NAC. The anti-asthmatic potential of NAC may be explained by its suppressant influence on IgE antibody formation, pro-inflammatory cytokines production, eosinophil infiltration, and oxidative stress.

N-Acetylcysteine for Cardiac Protection During Coronary Artery Reperfusion: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Coronary artery reperfusion is essential for the management of symptoms in the patients with myocardial ischemia. However, the benefit of reperfusion often comes at an expense of paradoxical injury, which contributes to the adverse events, and sometimes heart failure. Reperfusion is known to increase the production of reactive oxygen species (ROS). We address whether N-acetylcysteine (NAC) reduces the ROS and alleviates reperfusion injury by improving the clinical outcomes. A literature search for the randomized controlled trials (RCTs) was carried out in the five biomedical databases for testing the effects of NAC in patients undergoing coronary artery reperfusion by percutaneous coronary intervention, thrombolysis, or coronary artery bypass graft. Of 787 publications reviewed, 28 RCTs were identified, with a summary of 2,174 patients. A meta-analysis using the random effects model indicated that NAC administration during or prior to the reperfusion procedures resulted in a trend toward a reduction in the level of serum cardiac troponin (cTn) [95% CI, standardized mean difference (SMD) −0.80 (−1.75; 0.15), p = 0.088, n = 262 for control, 277 for NAC group], and in the incidence of postoperative atrial fibrillation [95% CI, relative risk (RR) 0.57 (0.30; 1.06), p = 0.071, n = 484 for control, 490 for NAC group]. The left ventricular ejection fraction or the measures of length of stay in intensive care unit (ICU) or in hospital displayed a positive trend that was not statistically significant. Among the nine trials that measured ROS, seven showed a correlation between the reduction of lipid peroxidation and improved clinical outcomes. These lines of evidence support the potential benefit of NAC as an adjuvant therapy for cardiac protection against reperfusion injury.

Communication Between Cardiomyocytes and Fibroblasts During Cardiac Ischemia/Reperfusion and Remodeling: Roles of TGF-β, CTGF, the Renin Angiotensin Axis, and Non-coding RNA Molecules

Communication between cells is a foundational concept for understanding the physiology and pathology of biological systems. Paracrine/autocrine signaling, direct cell-to-cell interplay, and extracellular matrix interactions are three types of cell communication that regulate responses to different stimuli. In the heart, cardiomyocytes, fibroblasts, and endothelial cells interact to form the cardiac tissue. Under pathological conditions, such as myocardial infarction, humoral factors released by these cells may induce tissue damage or protection, depending on the type and concentration of molecules secreted. Cardiac remodeling is also mediated by the factors secreted by cardiomyocytes and fibroblasts that are involved in the extensive reciprocal interactions between these cells. Identifying the molecules and cellular signal pathways implicated in these processes will be crucial for creating effective tissue-preserving treatments during or after reperfusion. Numerous therapies to protect cardiac tissue from reperfusion-induced injury have been explored, and ample pre-clinical research has attempted to identify drugs or techniques to mitigate cardiac damage. However, despite great success in animal models, it has not been possible to completely translate these cardioprotective effects to human applications. This review provides a current summary of the principal molecules, pathways, and mechanisms underlying cardiomyocyte and cardiac fibroblast crosstalk during ischemia/reperfusion injury. We also discuss pre-clinical molecules proposed as treatments for myocardial infarction and provide a clinical perspective on these potential therapeutic agents.

The Clinical Efficacy of N-Acetylcysteine in the Treatment of ST Segment Elevation Myocardial Infarction

The aim of this study was to evaluate the clinical efficacy of N-acetylcysteine (NAC) in the treatment of ST segment elevation myocardial infarction (STEMI).PubMed, EMBASE, Cochrane Library, and Web of Science were searched systematically from the establishment of the database to June 2020. Two researchers independently completed literature screening and data extraction and conducted a meta-analysis.Nine articles including 1419 patients were enrolled. Meta-analysis showed that all-cause mortality [RR = 0.56, 95%CI (0.33, 0.93), P = 0.02], occurrence of major adverse cardiovascular events (MACE) [RR = 0.63, 95%CI (0.47, 0.85), P = 0.002], and myocardial enzyme hs-TnT level [SMD = -0.42, 95%CI (-0.71, -0.13), P = 0.005] were significantly lower in patients with STEMI treated with NAC than those in the control group. There was no significant difference between the NAC group and the control group in new congestive heart failure [RR = 0.94, 95%CI (0.48, 1.82), P = 0.84], ejection fraction [MD = 2.00, 95%CI (-0.59, 4.60), P = 0.13], and CK-MB [SMD = -0.18, 95%CI (-0.47, 0.11), P = 0.23]. There was no significant difference in the occurrence of adverse reactions between the NAC group and the control group [RR = 1.04, 95%CI (0.57-1.89), P = 0.90].NAC can reduce the all-cause mortality and MACE cases of STEMI.

Biphasic changes in TGF-β1 signaling drive NSAID-induced multi-organ damage

The clinical utility of non-steroidal anti-inflammatory drugs (NSAIDs), used extensively worldwide, is limited by adverse cardiac events resulting from chronic drug exposure. Here, we provide evidence identifying transforming growth factor β (TGF-β1), released from multiple tissues, as a critical driver of NSAID-induced multi-organ damage. Biphasic changes in TGF-β1 levels in liver and heart were accompanied by ROS generation, cell death, fibrotic remodeling, compromised cardiac contractility and elevated liver enzymes. Pharmacological inhibition of TGF-βRI signaling markedly improved heart and liver function and increased overall survival of animals exposed to multiple NSAIDs, effects likely mediated by reductions in NOX-dependent ROS generation. Notably, the beneficial impact of TGF-βRI blockade was confined to a critical window wherein consecutive, but not concurrent, inhibitor administration improved cardiac and hepatic endpoints. Remarkably, in addition to ameliorating indomethacin-mediated myofilament disruptions, cardiac TGF-βRI knockdown lead to drastic reductions in TGF-β1 production accompanied by lessening in intestinal lesioning underscoring the importance of endocrine TGF-β1 signaling in NSAID-driven tissue injury. Indeed, gastric ulceration was associated with a higher incidence of cardiac complications in a human cohort underscoring the critical importance of circulation-facilitated peripheral organ system interconnectedness in efforts seeking to mitigate the toxic side effects of chronic NSAID use.

Therapeutic Efficacy of Antioxidants in Ameliorating Obesity Phenotype and Associated Comorbidities

Obesity has been a worldwide epidemic for decades. Despite the abundant increase in knowledge regarding the etiology and pathogenesis of obesity, the prevalence continues to rise with estimates predicting considerably higher numbers by the year 2030. Obesity is characterized by an abnormal lipid accumulation, however, the physiological consequences of obesity are far more concerning. The development of the obesity phenotype constitutes dramatic alterations in adipocytes, along with several other cellular mechanisms which causes substantial increase in systemic oxidative stress mediated by reactive oxygen species (ROS). These alterations promote a chronic state of inflammation in the body caused by the redox imbalance. Together, the systemic oxidative stress and chronic inflammation plays a vital role in maintaining the obese state and exacerbating onset of cardiovascular complications, Type II diabetes mellitus, dyslipidemia, non-alcoholic steatohepatitis, and other conditions where obesity has been linked as a significant risk factor. Because of the apparent role of oxidative stress in the pathogenesis of obesity, there has been a growing interest in attenuating the pro-oxidant state in obesity. Hence, this review aims to highlight the therapeutic role of antioxidants, agents that negate pro-oxidant state of cells, in ameliorating obesity and associated comorbidities. More specifically, this review will explore how various antioxidants target unique and diverse pathways to exhibit an antioxidant defense mechanism.

Spontaneous Recurrent Seizures Mediated Cardiac Dysfunction via mTOR Pathway Upregulation: A Putative Target for SUDEP Management

Background:

Alteration in electrophysiology, leading to cardiac dysfunction and subsequently a nontraumatic death is a complication of epilepsy known as “SUDEP” (Sudden Unexpected Death in Epilepsy).

Aims:

The present study was designed to understand the molecular changes and cardiac parameters during different phases of epileptogenesis in lithium-pilocarpine (Li-pilo) rat model of epilepsy.

Methods:

The animals were exposed to Li-pilo to induce Spontaneous Recurrent Seizures (SRS). Noninvasive blood pressure and electrocardiography was recorded at 7th, 28th and 75th day following pilocarpine administration, considered as latent, initial and late SRS phases, respectively. The serum biochemistry, cardiac histopathology, protein and mRNA expressions were studied, following electrocardiography on day 75.

Results:

The mean arterial pressure decreased during the latent phase, thereafter it progressively increased during the initial and the late SRS phases, as compared to the basal and the latent phase. Histopathological analysis of the heart sections indicated hypertrophy, degenerative changes and fibrous tissue deposition in epileptic animals, along with increased levels of lactate dehydrogenase and creatine kinase-MB in the serum. The expression of HIF-1α, phospho-S6, phospho-mTOR, TGF-β, collagen I and Na+/K+-ATPase α1 proteins, and mRNA levels of HIF-1α, mTOR, Rps6, Scn1b, Scn3b, Nav1.5 and TGF-β were increased in the cardiac tissue of epileptic animals, as compared to control.

Conclusion:

Our results conclusively showed that Li-pilo-induced SRS leads to cardiac dysfunction via mTOR pathway upregulation, thus suggested the regulatory control of mTOR pathway as a potential target for SUDEP management.

Antinociceptive and anti-inflammatory effects of N-acetylcysteine and verapamil in Wistar rats

Background

Antinociceptive anti-inflammatory drugs have many adverse effects. The goal of this investigation is to study the probable anti-inflammatory and analgesic effects of verapamil and N-acetylcysteine (NAC) in experimental rats.

Methods

Adult male Wistar rats were randomly divided into 4 groups in the antinociceptive study, each containing 6 rats; the normal control group, which received saline (1 mL/kg); the diclofenac group, which received diclofenac sodium (5 mg/kg); the NAC group, which received NAC (125 mg/kg); and the verapamil group, which received verapamil (8 mg/kg). In the anti-inflammatory study, 5 groups were used, the 4 previous groups with the addition of an edema control group, received saline and were subjected to formalin test. Hot plate latency time was recorded for antinociceptive evaluation. Paw edema thickness and biochemical parameters were recorded for anti-inflammatory evaluation.

Results

Administration of NAC showed significant prolongation of hot plate latency time at 1 hour when compared to the control group while verapamil showed a significant prolongation of hot plate latency time at 1 and 2 hours when compared to the control group and NAC group values. Administration of NAC and verapamil significantly decreased paw edema thickness at 2, 4, and 8 hours when compared to edema control values. Regarding biochemical markers, NAC and verapamil significantly decreased serum nitric oxide synthase, C-reactive protein, and cyclooxygenase- 2 levels compared to the edema control value. In accordance, a marked improvement of histopathological findings was observed with both drugs.

Conclusions

NAC and verapamil have antinociceptive and anti-inflammatory effects comparable to diclofenac sodium.

Differential Roles of Cysteinyl Cathepsins in TGF-β Signaling and Tissue Fibrosis

Transforming growth factor beta (TGF-β) signaling contributes to tissue fibrosis. Here we demonstrate that TGF-β enhances CatS and CatK expression but reduces CatB and CatL expression in mouse kidney tubular epithelial cells (TECs). CatS- and CatK deficiency reduces TEC nuclear membrane importer importin-β expression, Smad-2/3 activation, and extracellular matrix (ECM) production. Yet CatB- and CatL-deficiency displays the opposite observations with reduced nuclear membrane exporter RanBP3 expression. CatS and CatK form immunocomplexes with the importin-β and RanBP3 more effectively than do CatB and CatL. On the plasma membrane, CatS and CatK preferentially form immunocomplexes with and activate TGF-β receptor-2, whereas CatB and CatL form immunocomplexes with and inactivate TGF-β receptor-1. Unilateral ureteral obstruction-induced renal injury tests differential cathepsin activities in TGF-β signaling and tissue fibrosis. CatB- or CatL-deficiency exacerbates fibrosis, whereas CatS- or CatK-deficiency protects kidneys from fibrosis. These cathepsins exert different effects in the TGF-β signaling cascade independent of their proteolytic properties.

A Multi-Trait Approach Identified Genetic Variants Including a Rare Mutation in RGS3 with Impact on Abnormalities of Cardiac Structure/Function

Heart failure is a major cause for premature death. Given the heterogeneity of the heart failure syndrome, identifying genetic determinants of cardiac function and structure may provide greater insights into heart failure. Despite progress in understanding the genetic basis of heart failure through genome wide association studies, the heritability of heart failure is not well understood. Gaining further insights into mechanisms that contribute to heart failure requires systematic approaches that go beyond single trait analysis. We integrated a Bayesian multi-trait approach and a Bayesian networks for the analysis of 10 correlated traits of cardiac structure and function measured across 3387 individuals with whole exome sequence data. While using single-trait based approaches did not find any significant genetic variant, applying the integrative Bayesian multi-trait approach, we identified 3 novel variants located in genes, RGS3, CHD3, and MRPL38 with significant impact on the cardiac traits such as left ventricular volume index, parasternal long axis interventricular septum thickness, and mean left ventricular wall thickness. Among these, the rare variant NC_000009.11:g.116346115C > A (rs144636307) in RGS3 showed pleiotropic effect on left ventricular mass index, left ventricular volume index and maximal left atrial anterior-posterior diameter while RGS3 can inhibit TGF-beta signaling associated with left ventricle dilation and systolic dysfunction.

Transforming growth factor β and its role in heart disease

Myocardial infarction (MI) is a major form of heart disease that leads to immediate cardiomyocyte death due to ischemia and eventually fibrosis and scar formation and further dysfunction of myocardium and heart failure. Extracellular matrix (ECM) production and tissue repair is conducted by myofibroblasts, which are formed from the normal quiescent cardiac fibroblasts following transformational changes, through the active participation of transforming growth factor β (TGFβ) and its signaling pathways. TGFβ appears to be a ‘Master of all trades’, with respect to cardiac fibrosis, as it can promote cardiomyocyte apoptosis and cardiac hypertrophy. TGFβ signaling involves its binding to TGFβ receptor type II (TGFβRII), which recruits TGFβ receptor type I (TGFβRI), which are also known as activin receptor-like kinase (ALK) in five different isoforms. In canonical signaling pathways, ALK5 activates Smads 2 and 3, and ALK1 activates Smads 1 and 5. These pairs of Smads form a corresponding complex and then bind to Smad 4, to translocate into the nucleus, where transcriptional reprogramming is carried out to promote myofibroblast formation and ECM production, eventually leading to cardiac fibrosis. TGFβ levels are elevated in MI, thereby aggravating the myocardial injury further. Several microRNAs are involved in the regulation of TGFβ signaling at different steps, affecting different components. Therapeutic targeting of TGFβ signaling at ALK1-5 receptor activity level has met with limited success and extensive research is needed to develop therapies based on the components of TGFβ signaling pathway, for instance cardiac dysfunction and heart failure.

N-acetylcysteine attenuates the development of cardiac fibrosis and remodeling in a mouse model of heart failure

Oxidative stress plays a central role in the pathogenesis of heart failure. We aimed to determine whether the antioxidant N‐acetylcysteine can attenuate cardiac fibrosis and remodeling in a mouse model of heart failure. Minipumps were implanted subcutaneously in wild‐type mice (n = 20) and mice with cardiomyopathy secondary to cardiac specific overexpression of mammalian sterile 20‐like kinase 1 (MST‐1; n = 18) to administer N‐acetylcysteine (40 mg/kg per day) or saline for a period of 8 weeks. At the end of this period, cardiac remodeling and function was assessed via echocardiography. Fibrosis, oxidative stress, and expression of collagen types I and III were quantified in heart tissues. Cardiac perivascular and interstitial fibrosis were greater by 114% and 209%, respectively, in MST‐1 compared to wild type (P ≤ 0.001). In MST‐1 mice administered N‐acetylcysteine, perivascular and interstitial fibrosis were 40% and 57% less, respectively, compared to those treated with saline (P ≤ 0. 03). Cardiac oxidative stress was 119% greater in MST‐1 than in wild type (P < 0.001) and N‐acetylcysteine attenuated oxidative stress in MST‐1 by 42% (P = 0.005). These data indicate that N‐acetylcysteine can blunt cardiac fibrosis and related remodeling in the setting of heart failure potentially by reducing oxidative stress. This study provides the basis to investigate the role of N‐acetylcysteine in chronic heart failure.

A new Agkistrodon halys venom-purified protein C activator prevents myocardial fibrosis in diabetic rats

Aim

To assess the effects of protein C activator (PCA) from Agkistrodon halys snake venom on cardiac fibrosis in streptozotocin (STZ) induced diabetic rat model, and investigate the mechanisms of its action.

Methods

PCA was identified by one-dimensional reversed phase liquid chromatography – mass spectrometry/mass spectrometry. Male Sprague-Dawley rats (120-140 g) were randomly assigned to negative control (NC) and diabetic group. Diabetes was induced by STZ in high-fat diet fed rats. Diabetic group was subdivided into three groups: diabetic group (DM), diabetic group treated with PCA (0.5, 2, and 8 mg/kg), and diabetic group treated with metformin (5 mg/kg, positive control). NC and DM groups received the same volume of distilled water. Left ventricular mass index (LVWI) and collagen volume fraction were measured by hematoxylin and eosin and Masson staining. Transforming growth factor beta-1 (TGF-β1) and interleukin 1 beta (IL-1β) levels were determined by enzyme-linked immunosorbent assay.

Results

The diabetic rat model was successfully established by STZ induction and high-fat diet. Glucose level, LVWI, TGF-β1 and IL-1β level, and collagen volume fraction were significantly reduced in diabetic rats treated by PCA in a dose-dependent manner (P < 0.050), especially in the high dose (8 mg/kg) group (P < 0.010), compared to diabetes group. The high dose PCA had the same effect as metformin positive control in reducing the level of fasting blood glucose. PCA decreased the expression of MMP-2 and reduced that of TIMP-2.

Conclusion

Our results indicate that PCA has anti-fibrotic effects and that it may be used to treat myocardial fibrosis.

N-acetylcysteine Plus Deferoxamine Improves Cardiac Function in Wistar Rats After Non-reperfused Acute Myocardial Infarction

The antioxidant N-acetycysteine can turn into a prooxidant molecule in presence of iron ions. Thus, our goal was to test if the association of N-acetylcysteine (NAC) and an iron chelator (deferoxamine--DFX) in a rodent model of acute myocardial infarction (AMI) improves cardiac function. Male Wistar rats were subjected to a SHAM surgery or AMI. The animals were randomized: vehicle, NAC (25 mg/kg for 28 days), DFX (40 mg/kg for 7 days), or NAC plus DFX (NAC plus DFX, respectively). Animals were killed 28 days after the AMI. Animals treated with NAC/DFX showed an increase in left ventricular ejection fraction at 28 days when compared with vehicle group (45.2 ± 10.9 % vs. 34.7 ± 8.7 %, p = 0.03). Antioxidant effect of NAC/DFX treatment decreased 4-hydroxynonenal when compared to AMI group (p = 0.06). In conclusion, we showed beneficial effect of NAC/DFX association in improving left ventricle function in an experimental AMI.

Paeoniflorin ameliorates acute myocardial infarction of rats by inhibiting inflammation and inducible nitric oxide synthase signaling pathways

Paeoniflorin (PF) is the main active component of the commonly used Traditional Chinese Medicine peony, Paeonia Suffruticosa. PF has diverse biological functions and exhibits anti‑oxidative, anti‑inflammatory and anti‑apoptotic activity. Inducible nitric oxide synthase (iNOS) is a catalyzing enzyme that is involved in the synthesis of nitric oxide (NO). NO has an important regulatory role in the cardiovascular, immune and nervous systems. PF has previously been demonstrated to inhibit the gene expression of iNOS. The present study aimed to identify a potentially novel cytoprotective function of PF, and to elucidate its effects against myocardial ischemic damage in a rat model of acute myocardial infarction (AMI). PF was able to significantly decrease the myocardial infarct size as well as the activities of creatine kinase (CK), the MB isoenzyme of CK, lactate dehydrogenase and cardiac troponin T. In addition, in the PF‑treated groups, the expression levels of tumor necrosis factor‑α, interleukin (IL)‑1β, IL‑6 and nuclear factor‑κB were markedly inhibited. Furthermore, treatment with PF inhibited the activities and protein expression levels of iNOS. Decreased caspase‑3 and caspase‑9 activities were also observed in the AMI rat model treated with various doses of PF. The results of the present study indicated that the cardioprotective effects of PF may be associated with the inhibition of inflammation and iNOS signaling pathways.

Good and bad sides of TGFβ-signaling in myocardial infarction

Myocardial infarction is a prevailing cause of death in industrial countries. In spite of the good opportunities we have nowadays in interventional cardiology to reopen the clotted coronary arteries for reperfusion of ischemic areas, post-infarct remodeling emerges and contributes to unfavorable structural conversion processes in the myocardium, finally resulting in heart failure. The growth factor TGFβ is upregulated during these processes. In this review, an overview on the functional role of TGFβ signaling in the process of cardiac remodeling is given, as it can influence apoptosis, fibrosis and hypertrophy thereby predominantly aggravating ischemia/reperfusion injury.

Complement C3c as a biomarker in heart failure

Introduction. Experimental data indicates an important role of the innate immune system in cardiac remodeling and heart failure (HF). Complement is a central effector pathway of the innate immune system. Animals lacking parts of the complement system are protected from adverse remodeling. Based on these data, we hypothesized that peripheral complement levels could be a good marker for adverse remodeling and prognosis in patients with HF. Methods and Results. Since complement activation converges on the complement factor C3, we measured serum C3c, a stable C3-conversion product, in 197 patients with stable systolic HF. Subgroups with normal and elevated C3c levels were compared. C3c levels were elevated in 17% of the cohort. Patients with elevated C3c levels exhibited a trend to better survival, slightly higher LVEF, and lower NTpro-BNP values in comparison to patients with normal C3c values. No differences were found regarding NYHA functional class. Significantly more patients with elevated C3c had preexisting diabetes. The prevalence of CAD, arterial hypertension, and atrial fibrillation was not increased in patients with elevated C3c. Conclusion. Elevated C3c levels are associated with less adverse remodeling and improved survival in patients with stable systolic heart failure.