4-hydroxy-2-nonenal and Cardiomyopathies

To investigate the effect of long non-coding ribonucleic acid nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1) on lipopolysaccharide (LPS)-induced myocardial injury in mice and the underlying mechanism. This study aims to provide some references for the prevention and treatment of sepsis-induced myocardial injury.. According to the random number table, 60 male C57 mice were divided into the Sham group (n=20), LPS group (n=20) and LPS + NEAT1 small interfering ribonucleic acid (siRNA) group (n=20). Sepsis-induced myocardial injury model in mice was established by intraperitoneal injection of LPS (10 mg/kg), and the NEAT1 knockout model was established by tail vein injection of NEAT1 siRNAs. After 12 h, the cardiac function of mice in each group was detected via the two-dimensional ultrasound; ejection fraction [EF (%)] and fraction shortening [FS (%)] were recorded. Hematoxylin and eosin (H&E) staining was conducted to evaluate the pathological changes in the heart tissues in each group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to detect the apoptotic levels of myocardial cells and fibroblasts in each group. In addition, the expression level of the oxidative stress marker 4-hydroxynonena (4-HNE) and the positive proportions of cluster of differentiation 45 (CD45) and CD68 in the mouse heart of three groups were detected via immunohistochemical staining. Moreover, the messenger RNA (mRNA) expression levels of inflammatory indicators [interleukin-1 (IL-1), IL-6, monocyte chemotactic protein 1 (MCP-1) and tumor necrosis factor-alpha (TNF-α)] in mouse serum of the three groups were examined by enzyme-linked immunosorbent assay (ELISA). Finally, the effects of NEAT1 siRNAs on the Toll-like receptor 2 (TLR2)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway were detected by Western blotting.. ENEAT1 knockdown could significantly improve ischemia/reperfusion (I/R)-induced cardiac insufficiency in rats, and increase EF (%) and FS (%) (p<0.05). Besides, NEAT1 knockdown remarkably inhibited the LPS-induced myocardial injury. Compared with the LPS group, LPS + NEAT 1 siRNA group has more orderly arranged cardiac myofilament, a lower degree of degradation and necrosis, and significantly reduced cell edema. TUNEL staining showed that NEAT1 knockdown markedly reduced LPS-induced apoptosis of cardiac cells (p<0.05). Immunohistochemical results revealed that NEAT1 knockdown could remarkably reverse LPS-induced elevation of the myocardial 4-HNE expression and decrease the oxidative stress in the heart (p<0.05). At the same time, CD45+ and CD68+ cells were reduced after NEAT1 knockdown in myocardial tissues (p<0.05). Reverse Transcription-Polymerase Chain Reaction (RT-PCR) showed that the mRNA levels of inflammatory indicators in LPS + NEAT1 siRNA group were lower than that in the LPS group (p<0.05). According to Western blotting results, NEAT1 siRNAs could significantly downregulate the protein expressions of TLR2 and p-p65.. NEAT1 knockdown can improve LPS-induced myocardial injury in mice by inhibiting the TLR2/NF-κB signaling pathway. LncRNA NEAT1 is expected to be a potential target for clinical treatment of the sepsis-induced myocardial injury.

Topics: Aldehydes; Animals; Apoptosis; Biomarkers; Cardiomyopathies; Disease Models, Animal; Echocardiography; Gene Knockdown Techniques; Humans; Inflammation Mediators; Lipopolysaccharides; Male; Mice; Myocardium; Myocytes, Cardiac; NF-kappa B; Oxidative Stress; RNA, Long Noncoding; RNA, Small Interfering; Sepsis; Signal Transduction; Toll-Like Receptor 2

Topics: Age Factors; Aging; Aldehydes; Animals; Apoptosis; Cardiomyopathies; Cell Line, Tumor; Cell Proliferation; Cytokines; Cytoprotection; Female; Fibroblasts; Fibrosis; Glycogen Synthase Kinase 3 beta; Humans; Intracellular Signaling Peptides and Proteins; Matrix Metalloproteinase 2; Mice, Inbred C57BL; Myocytes, Cardiac; Protective Agents; Proto-Oncogene Proteins c-akt; Receptor, Fibroblast Growth Factor, Type 2; Signal Transduction; Transforming Growth Factor beta1

Sepsis is a leading cause of mortality among patients in intensive care units across the USA. Thioredoxin-1 (Trx-1) is an essential 12 kDa cytosolic protein that, apart from maintaining the cellular redox state, possesses multifunctional properties. In this study, we explored the possibility of controlling adverse myocardial depression by overexpression of Trx-1 in a mouse model of severe sepsis.. Adult C57BL/6J and Trx-1. Echocardiography analysis showed preserved cardiac function in the Trx-1. Our results indicate that overexpression of Trx-1 attenuates cardiac dysfunction during CLP. The mechanism of action may involve reduction of oxidative stress, apoptosis, and vascular permeability through activation of Trx-1/HO-1 and anti-apoptotic protein survivin.

Topics: Aldehydes; Animals; Apoptosis; Capillary Permeability; Cardiomyopathies; Carrier Proteins; Caspase 3; Disease Models, Animal; Echocardiography; Female; Heart; Heme Oxygenase-1; Immunohistochemistry; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myocardium; Oxidative Stress; Repressor Proteins; Sepsis; Survivin; Thioredoxins; Tyrosine

Mitochondrial aldehyde dehydrogenase (ALDH2) protects against cardiac injury via reducing production of 4-hydroxynonenal (4-HNE) and ROS. This study was designed to examine the impact of ALDH2 on doxorubicin (DOX)-induced cardiomyopathy and mechanisms involved with a focus on autophagy. 4-HNE and autophagic markers were detected by Western blotting in ventricular tissues from normal donors and patients with idiopathic dilated cardiomyopathy. Cardiac function, 4-HNE and levels of autophagic markers were detected in WT, ALDH2 knockout or ALDH2 transfected mice treated with or without DOX. Autophagy regulatory signaling including PI-3K, AMPK and Akt was examined in DOX-treated cardiomyocytes incubated with or without ALDH2 activator Alda-1. DOX-induced myocardial dysfunction, upregulation of 4-HNE and autophagic proteins were further aggravated in ALDH2 knockout mice while they were ameliorated in ALDH2 transfected mice. DOX downregulated Class I and upregulated Class III PI3-kinase, the effect of which was augmented by ALDH2 deletion. Accumulation of 4-HNE and autophagic protein markers in DOX-induced cardiomyocytes was significantly reduced by Alda-1. DOX depressed phosphorylated Akt but not AMPK, the effect was augmented by ALDH2 knockout. The autophagy inhibitor 3-MA attenuated, whereas autophagy inducer rapamycin mimicked DOX-induced cardiomyocyte contractile defects. In addition, rapamycin effectively mitigated Alda-1-offered protective action against DOX-induced cardiomyocyte dysfunction. Our data further revealed downregulated ALDH2 and upregulated autophagy levels in the hearts from patients with dilated cardiomyopathy. Taken together, our findings suggest that inhibition of 4-HNE and autophagy may be a plausible mechanism underscoring ALDH2-offered protection against DOX-induced cardiac defect. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy".

Topics: Aldehyde Dehydrogenase; Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Animals; Autophagy; Cardiomyopathies; Down-Regulation; Doxorubicin; Female; Heart; Humans; Inactivation, Metabolic; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Myocardial Contraction; Myocardium; Myocytes, Cardiac; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Random Allocation; Signal Transduction; TOR Serine-Threonine Kinases; Up-Regulation

The prevalence of sleep apnea is very high in patients with heart failure (HF). The aims of this study were to investigate the influence of intermittent hypoxia (IH) on the failing heart and to evaluate the antioxidant effect of hydrogen gas. Normal male Syrian hamsters (n = 22) and cardiomyopathic (CM) hamsters (n = 33) were exposed to IH (repeated cycles of 1.5 min of 5% oxygen and 5 min of 21% oxygen for 8 h during the daytime) or normoxia for 14 days. Hydrogen gas (3.05 vol/100 vol) was inhaled by some CM hamsters during hypoxia. IH increased the ratio of early diastolic mitral inflow velocity to mitral annulus velocity (E/e', 21.8 vs. 16.9) but did not affect the LV ejection fraction (EF) in normal Syrian hamsters. However, IH increased E/e' (29.4 vs. 21.5) and significantly decreased the EF (37.2 vs. 47.2%) in CM hamsters. IH also increased the cardiomyocyte cross-sectional area (672 vs. 443 μm(2)) and interstitial fibrosis (29.9 vs. 9.6%), along with elevation of oxidative stress and superoxide production in the left ventricular (LV) myocardium. Furthermore, IH significantly increased the expression of brain natriuretic peptide, β-myosin heavy chain, c-fos, and c-jun mRNA in CM hamsters. Hydrogen gas inhalation significantly decreased both oxidative stress and embryonic gene expression, thus preserving cardiac function in CM hamsters. In conclusion, IH accelerated LV remodeling in CM hamsters, at least partly by increasing oxidative stress in the failing heart. These findings might explain the poor prognosis of patients with HF and sleep apnea.

Topics: Aldehydes; Animals; Body Weight; Cardiomyopathies; Cricetinae; Cysteine Proteinase Inhibitors; Gases; Gene Expression Regulation, Developmental; Heart Ventricles; Hydrogen; Hypoxia; Mesocricetus; Organ Size; Superoxides; Ultrasonography; Ventricular Remodeling

This study describes increased sarcolemmal permeability and myofilamentar damage that occur together with lipid peroxidation and protein nitration in the myocardium in severe sepsis induced by cecal ligation and puncture. Male C57BL/6 mice were submitted to moderate and severe septic injury and sham operation. Using light and laser confocal microscopy, diffuse foci of myocytolysis associated with focal disruption of the actin/myosin contractile apparatus could be seen in hearts with severe septic injury. The myocardial expressions of the sarcomeric proteins myosin and actin were downregulated by both severe and moderate injuries. The detection of albumin staining in the cytoplasm of myocytes to evaluate sarcolemmal permeability provided evidence of severe and mild injury of the plasma membrane in hearts with severe and moderate septic injury, respectively. The administration of a superoxide scavenger caused marked reduction of sarcolemmal permeability, indicating the involvement of free radicals in its genesis. On electron microscopy, these changes were seen to correspond to spread blocks of a few myocytes with fragmentation and dissolution of myofibrils, intracellular edema, and, occasionally, rupture of the sarcolemma. In addition, oxidative damage to lipids, using anti-4-hydroxynonenal, an indicator of oxidative stress and disruption of plasma membrane lipids, and to proteins, using antinitrotyrosine, a stable biomarker of peroxynitrite-mediated protein nitration, was demonstrated. These findings make plausible the hypothesis that increased sarcolemmal permeability might be a primary event in myocardial injury in severe sepsis possibly due to oxidative damage to lipids and proteins that could precede phenotypic changes that characterize a septic cardiomyopathy.

Topics: Actins; Aldehydes; Animals; Cardiomyopathies; Cecum; Down-Regulation; Ligation; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Models, Animal; Myocardium; Myosins; Permeability; Proteins; Punctures; Sarcolemma; Sepsis

Several lines of research suggest that mitochondria play a role in the etiopathogenesis of diabetic cardiomyopathy, although the mechanisms involved are still debated. In the present study, we report that State 3 oxygen consumption decreases by approximately 35% with glutamate and by approximately 30% with succinate in mitochondria from diabetic rat hearts compared to controls. In these mitochondria the enzymatic activities of complex I and complex II are also decreased to a comparable extent. Western blot analysis of mitochondrial protein pattern using antibodies recognizing proteins modified by the lipid peroxidation product 4-hydroxynonenal indicates the FAD-containing subunit of succinate dehydrogenase as one of the targets of this highly reactive aldehyde. In rats diabetic for 6 or 12 weeks, insulin supplementation for 2 weeks decreases the level of protein modified by 4-hydroxynonenal and restores mitochondrial respiration and enzyme activity to control level. Taken together, these results: (1) indicate that 4-hydroxynonenal is endogenously produced within diabetic mitochondria and forms an adduct with selective mitochondrial proteins, (2) identify one of these proteins as a subunit of succinate dehydrogenase, and (3) provide strong evidence that insulin treatment can reverse and ameliorate free radical damage and mitochondrial function under diabetic conditions.

Topics: Aldehydes; Animals; Cardiomyopathies; Cell Respiration; Diabetes Mellitus, Experimental; Electron Transport Complex II; Free Radicals; Insulin; Lipid Peroxidation; Male; Mitochondria, Heart; Mitochondrial Proteins; Oxygen Consumption; Rats; Rats, Sprague-Dawley; Succinate Dehydrogenase

Previous studies suggest oxygen free radicals' involvement in the etiology of cardiomyopathy with cataracts. To investigate the role of free radicals in the pathogenesis of the cardiomyopathy with cataracts and complex I deficiency, fibroblasts from patients were assessed for hydroxyl radical formation and aldehydic lipid peroxidation products with and without redox active agents that increase free radicals. The rate of hydroxyl radical formation in patient cells was increased over 2-10-fold under basal conditions, and up to 20-fold after menadione or doxorubicin treatment compared with normal cells. We also found an overproduction of aldehydes in patient cells both under basal conditions and after treatment. Both hydroxyl radicals and toxic aldehydes such as hexanal, 4-hydroxynon-2-enal, and malondialdehyde were elevated in cells from patients with three types of complex I deficiency. In contrast, acyloins, the less toxic conjugated products of pyruvate and saturated aldehydes, were lower in the patient cells. Our data provide direct evidence for the first time that complex I deficiency is associated with excessive production of hydroxyl radicals and lipid peroxidation. The resultant damage may contribute to the early onset of cardiomyopathy and cataracts and death in early infancy in affected patients with this disease.

Topics: Aldehydes; Cardiomyopathies; Cataract; Cells, Cultured; Fatal Outcome; Female; Fibroblasts; Humans; Hydroxyl Radical; Infant, Newborn; Lipid Peroxidation; Malondialdehyde; NAD(P)H Dehydrogenase (Quinone); Skin