RESUMO
ABSTRACT: Background: Sepsis is a life-threatening systemic inflammatory disease that can cause many diseases, including acute kidney injury (AKI). Increasing evidence showed that a variety of circular RNAs were considered to be involved in the development of the disease. In this study, we aimed to elucidate the role and potential mechanism of circUSP42 in sepsis-induced AKI. Methods: HK2 cells were treated with lipopolysaccharide (LPS) to establish septic AKI cell model. The expression levels of circUSP42, microRNA-182-5p (miR-182-5p), and DUSP1 in LPS-treated HK2 cells were measured by quantitative real-time polymerase chain reaction or Western blot. Functional experiments were performed by using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine staining, flow cytometry, oxidative stress assay, and enzyme-linked immunosorbent assay. The potential target binding site between miR-182-5p and CircUSP42 or DUSP1 was verified by dual-luciferase reporter and RNA immunoprecipitation assays. Results: CircUSP42 and DUSP1 were downregulated in serum samples from patients with AKI and LPS-treated HK2 cells, while miR-182-5p was upregulated. Functionally, overexpression of CircUSP42 promoted cell proliferation and inhibited apoptosis, inflammation, and oxidative stress in LPS-triggered HK2 cells. Further mechanism analysis showed that miR-182-5p had potential binding sites with circUSP42 and DUSP1, and circUSP42 regulated LPS-induced cell damage by targeting miR-182-5p. At the same time, miR-182-5p knockdown inhibited LPS-treated HK2 cell damage by regulating DUSP1. In addition, circUSP42 induced DUSP1 expression via sponging miR-182-5p to ameliorate LPS-induced HK2 cell damage. Conclusion : Our results showed that circUSP42 overexpression might attenuate LPS-induced HK2 cell injury by regulating miR-182-5p/DUSP1 axis. This might provide therapeutic strategy for the treatment of sepsis.
Assuntos
Injúria Renal Aguda , MicroRNAs , Sepse , Humanos , Lipopolissacarídeos/toxicidade , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Apoptose/genética , Células Epiteliais , Sepse/genética , MicroRNAs/genética , Fosfatase 1 de Especificidade Dupla/genéticaRESUMO
Cardiac remodeling is a basic pathological process that enables the progression of multiple cardiac diseases to heart failure. Fibroblast growth factor 21 is considered a regulator in maintaining energy homeostasis and shows a positive role in preventing damage caused by cardiac diseases. This review mainly summarizes the effects and related mechanisms of fibroblast growth factor 21 on pathological processes associated with cardiac remodeling, based on a variety of cells of myocardial tissue. The possibility of Fibroblast growth factor 21 as a promising treatment for the cardiac remodeling process will also be discussed.
RESUMO
Ischemia/reperfusion (I/R) is a well-known injury to the myocardium, but the mechanism involved remains elusive. In addition to the well-accepted apoptosis theory, autophagy was recently found to be involved in the process, exerting a dual role as protection in ischemia and detriment in reperfusion. Activation of autophagy is mediated by mitochondrial permeability transition pore (MPTP) opening during reperfusion. In our previous study, we showed that MPTP opening is regulated by VDAC1, a channel protein located in the outer membrane of mitochondria. Thus, upregulation of VDAC1 expression is a possible trigger to cardiomyocyte autophagy via an unclear pathway. Here, we established an anoxia/reoxygenation (A/R) model in vitro to simulate the I/R process in vivo. At the end of A/R treatment, VDAC1, Beclin 1, and LC3-II/I were upregulated, and autophagic vacuoles were increased in cardiomyocytes, which showed a connection of VDAC1 and autophagy development. These variations also led to ROS burst, mitochondrial dysfunction, and aggravated apoptosis. Knockdown of VDAC1 by RNAi could alleviate the above-mentioned cellular damages. Additionally, the expression of PINK1 and Parkin was enhanced after A/R injury. Furthermore, Parkin was recruited to mitochondria from the cytosol, which suggested that the PINK1/Parkin autophagic pathway was activated during A/R. Nevertheless, the PINK1/Parkin pathway was effectively inhibited when VDAC1 was knocked-down. Taken together, the A/R-induced cardiomyocyte injury was mediated by VDAC1 upregulation, which led to cell autophagy via the PINK1/Parkin pathway, and finally aggravated apoptosis.
Assuntos
Mitocôndrias/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Canal de Ânion 1 Dependente de Voltagem/fisiologia , Animais , Apoptose , Autofagia , Linhagem Celular , Potencial da Membrana Mitocondrial , Miócitos Cardíacos , RatosRESUMO
Translocator protein (TSPO) is highly expressed in the cardiovascular system, exerting crucial effects on both myocardial damage and protection. However, the role and mechanism of TSPO in myocardial ischemia/reperfusion (I/R) injury remains elusive. In the current study, we subjected H9c2 cardiomyocytes to anoxia/reoxygenation (A/R) and knocked down TSPO expression by RNA interference to investigate the possible mechanism of TSPO on I/R injury. TSPO expression in cardiomyocytes was up-regulated when exposed to A/R, but normal in anoxic preconditioned (APC) cardiomyocytes. Moreover, A/R also led to an increase in reactive oxygen species (ROS), oxidative stress aggravation, mitochondrial membrane potential collapse, mitochondrial permeability transition pore (mPTP) opening, and cell apoptosis. However, these events were completely compensated by downregulating TSPO expression. TSPO-downregulated cardiomyocytes produced lesser lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), and showed lesser cytosol malondialdehyde (MDA) accumulation than normal cells after A/R injury. On the other hand, the TSPO- downregulated cells showed higher activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), mitochondrial function stabilization, resulting in less cell apoptosis and damage in case of A/R condition. In conclusion, TSPO expression is up-regulated under A/R injury, whereas repression of TSPO improves the endurance of cardiomyocytes against A/R injury by reducing oxidative stress, mitochondrial damage and cell apoptosis.
Assuntos
Proteínas de Transporte/biossíntese , Regulação para Baixo/fisiologia , Homeostase/fisiologia , Mitocôndrias/metabolismo , Miócitos Cardíacos/metabolismo , Estresse Oxidativo/fisiologia , Receptores de GABA-A/biossíntese , Animais , Proteínas de Transporte/genética , Hipóxia Celular/fisiologia , Linhagem Celular , Expressão Gênica , Ratos , Espécies Reativas de Oxigênio/metabolismo , Receptores de GABA-A/genéticaRESUMO
Our previous studies showed that the effect of resveratrol preventing mitochondrial permeability transition pore (mPTP) opening in myocardial ischemia/reperfusion injury was achieved by regulating voltage-dependent anion channel 1 (VDAC1). However, the underlying mechanism remains unclear. Previous studies demonstrated that the activity and function of VDAC1 are highly regulated by post-translational modification. In present study, we investigated whether resveratrol modulates VDAC1 phosphorylation to achieve cardioprotection and explored the signaling pathways involved. Our findings demonstrated that anoxia/reoxygenation (A/R) treatment, an ischemia/reperfusion model in vitro, enhanced VDAC1 phosphorylation in cardiomyocytes. Moreover, we found phosphorylated VDAC1 showed increased affinity to Bax, whereas interaction with hexokinase 2 (HK2) was reduced. Accordingly, the generation of reactive oxygen species increased, the mitochondrial membrane potential collapsed, mPTP opening increased and cytochrome c released into cytoplasm, thereby leading to increased apoptosis. Moreover, our data showed that pretreatment with resveratrol prior to A/R injury inhibited VDAC1 phosphorylation. Dephosphorylated VDAC1 using pretreated resveratrol promoted dissociation with Bax and binding to HK2, which subsequently protected cardiomyocytes against A/R injury. In addition, Akt and its downstream glycogen synthase kinase 3 ß (GSK3ß) were phosphorylated by the action of resveratrol. Akt inhibitor IV abrogated Akt-GSK3ß phosphorylation and thereby abolished the dephosphorylation activity of resveratrol on VDAC1. Moreover, all resveratrol-mediated protective effects on A/R injured cardiomyocytes were abolished by Akt inhibitor IV. Taken together, our data indicated that A/R injury enhanced VDAC1 phosphorylation in cardiomyocytes, whereas pretreatment with resveratrol dephosphorylated VDAC1 through the Akt-GSK3ß pathway, thereby protecting cardiomyocytes against A/R injury.
Assuntos
Cardiotônicos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Resveratrol/farmacologia , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Células Cultivadas , Glicogênio Sintase Quinase 3 beta/metabolismo , Miócitos Cardíacos/fisiologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Canal de Ânion 1 Dependente de Voltagem/metabolismoRESUMO
Vitamin C, an excellent reducing agent, aids in increasing absorbable ferrous iron in iron deficiency anemia. As an efficient antioxidant, it is still unknown whether vitamin C exerts protective effects against liver damage caused by iron excess and whether mitochondria are the target effectors of the above effects. In this study, 48 mice were randomly divided into a control group, iron-overload group, TAU-treated + iron-overload group and vitamin C-treated + iron-overload group with 12 mice per group. The mice were fed 4 months on pellet diets supplemented with iron in the form of ferrocene. The iron ratio in the diet was maintained at 0.2% (w/w) for 90 days and then 0.4% (w/w) for the remaining 30 days. Furthermore, 2 g kg-1 vitamin C and 20 mg kg-1 TAU were administered daily by oral gavage prior to iron-overload administration at 6 weeks and throughout the course of the experiments. We investigated the protective effects of vitamin C against liver damage by assessing the liver weight to body weight ratio (LW/BW), serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, and histological changes. In addition, enzymatic and non-enzymatic antioxidants, reactive oxygen species (ROS) generation, mitochondrial swelling, and mitochondrial membrane potential (MMP) were evaluated to clarify the antioxidant effects of vitamin C. We found that vitamin C significantly attenuated impaired liver function in mice induced by iron overload via antioxidation, whereas no significant effect on iron uptake was observed. Vitamin C targeted the mitochondria, preventing mitochondrial swelling, MMP dissipation, and ROS burst, thus inhibiting hepatic apoptosis. Collectively, our results suggest that vitamin C acts as a "double agent" in iron supplementation therapy for iron deficiency anemia, boosting iron absorption for preventing iron deficiency and preventing liver damage due to excessive iron intake during treatment.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Ácido Ascórbico/administração & dosagem , Sobrecarga de Ferro/complicações , Ferro/efeitos adversos , Hepatopatias/prevenção & controle , Alanina Transaminase , Anemia Ferropriva/complicações , Animais , Antioxidantes/administração & dosagem , Aspartato Aminotransferases , Suplementos Nutricionais/efeitos adversos , Suplementos Nutricionais/análise , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/efeitos adversos , Glutationa Peroxidase/metabolismo , Humanos , Ferro/administração & dosagem , Sobrecarga de Ferro/etiologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Hepatopatias/etiologia , Hepatopatias/metabolismo , Masculino , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Metalocenos/administração & dosagem , Metalocenos/efeitos adversos , Camundongos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
CDP138 is a calcium- and lipid-binding protein that is involved in membrane trafficking. Here, we report that mice without CDP138 develop obesity under normal chow diet (NCD) or high-fat diet (HFD) conditions. CDP138-/- mice have lower energy expenditure, oxygen consumption, and body temperature than wild-type (WT) mice. CDP138 is exclusively expressed in adrenal medulla and is colocalized with tyrosine hydroxylase (TH), a marker of sympathetic nervous terminals, in the inguinal fat. Compared with WT controls, CDP138-/- mice had altered catecholamine levels in circulation, adrenal gland, and inguinal fat. Adrenergic signaling on cyclic AMP (cAMP) formation and hormone-sensitive lipase (HSL) phosphorylation induced by cold challenge but not by an exogenous ß3 adrenoceptor against CL316243 were decreased in adipose tissues of CDP138-/- mice. Cold-induced beige fat browning, fatty acid oxidation, thermogenesis, and related gene expression were reduced in CDP138-/- mice. CDP138-/- mice are also prone to HFD-induced insulin resistance, as assessed by Akt phosphorylation and glucose transport in skeletal muscles. Our data indicate that CDP138 is a regulator of stress response and plays a significant role in adipose tissue browning, energy balance, and insulin sensitivity through regulating catecholamine secretion from the sympathetic nervous terminals and adrenal gland.
Assuntos
Tecido Adiposo Marrom/metabolismo , Catecolaminas/metabolismo , Proteínas de Homeodomínio/metabolismo , Resistência à Insulina/fisiologia , Proteínas de Membrana/metabolismo , Transporte Proteico/fisiologia , Glândulas Suprarrenais/metabolismo , Animais , Membrana Celular/metabolismo , Dieta Hiperlipídica/efeitos adversos , Metabolismo Energético/fisiologia , Expressão Gênica/fisiologia , Metabolismo dos Lipídeos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Fosforilação/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Esterol Esterase/metabolismo , Termogênese/fisiologiaRESUMO
We have recently demonstrated that Voltage-dependent anion channel 1 (VDAC1), a protein located in the mitochondrial outer membrane, is involved in the effects of resveratrol on the mitochondrial permeability transition pore (mPTP). However, the underlying mechanism of action remains to be elucidated. In the present study, we demonstrated that resveratrol promoted VDAC1 deacetylation in cardiomyocytes in response to anoxia/reoxygenation (A/R) injury. Moreover, silent information regulator of transcription 1 (SIRT1), a NAD+-dependent class III histone deacetylase, was up-regulated after pretreatment with resveratrol. Cells that were treated with Ex527, a specific inhibitor of SIRT1, showed a reduction in both SIRT1 expression and VDAC1 deacetylation, indicating that the deacetylation effect of resveratrol on VDAC1 is mediated by SIRT1. Furthermore, the ability deacetylated VDAC1 to bind to Bax was decreased after pretreatment with resveratrol, whereas Bcl-2 expression changed in the opposite direction. As a result, opening of the mPTP was restrained, the mitochondrial membrane potential was reserved, and cytochrome c release was inhibited, which subsequently decreased cardiomyocyte apoptosis. However, the cardioprotective effects observed after treatment of resveratrol could be abrogated by Ex527. In conclusion, resveratrol induces deacetylation of VDAC1 by SIRT1, thereby preventing mitochondria-mediated apoptosis in cardiomyocytes upon A/R injury.
Assuntos
Apoptose/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Oxigênio/metabolismo , Estilbenos/farmacologia , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Animais , Carbazóis/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Recém-Nascido , Potencial da Membrana Mitocondrial , Proteínas de Transporte da Membrana Mitocondrial , Poro de Transição de Permeabilidade Mitocondrial , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Resveratrol , Canal de Ânion 1 Dependente de Voltagem/genética , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Anion exchanger 3 (AE3) is known to serve crucial roles in maintaining intracellular chloride homeostasis by facilitating the reversible electroneutral exchange of Cl for HCO3 across the plasma membrane. Our previous studies reported that sasanquasaponin (SQS) can inhibit hypoxia/reoxygenation (H/R)induced elevation of intracellular Cl concentration ([Cl]i) and elicit cardioprotection by favoring Cl/HCO3 exchange of AE3. However, the molecular basis for SQSinduced increase of Cl/HCO3 exchange of AE3 remains unclear. The present study demonstrated that SQS activates protein kinase Cε (PKCε) and stimulates the phosphorylation of AE3 in H9c2 cells. Notably, SQSinduced AE3 phosphorylation was blocked by the PKCε selective inhibitor εV12, and a S67A mutation of AE3, indicating that SQS could promote phosphorylation of Ser67 of AE3 via a PKCεdependent regulatory signaling pathway. Additionally, both inhibition of PKCε by εV12 and S67A mutation of AE3 eradicated the SQSinduced increase of AE3 activity, reversed the inhibitory effect of SQS on H/Rinduced elevation of [Cl]i, Ca2+ overload and generation of reactive oxygen species, and eliminated SQSinduced cardioprotection. In conclusion, PKCεdependent phosphorylation of serine 67 on AE3 may be responsible for the increase of Cl/HCO3 exchange of AE3 and intracellular chloride efflux by SQS, and contributes to the cardioprotection of SQS against H/R in H9c2 cells.
Assuntos
Bicarbonatos/metabolismo , Antiportadores de Cloreto-Bicarbonato/metabolismo , Cloretos/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Oxigênio/metabolismo , Saponinas/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Cálcio/metabolismo , Cardiotônicos/farmacologia , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Creatina Quinase/metabolismo , Ativação Enzimática/efeitos dos fármacos , Células HEK293 , Humanos , L-Lactato Desidrogenase/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Proteína Quinase C-épsilon/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Inflammation plays a significant role in the development of obesity-related complications, but the molecular events that initiate and propagate such inflammation remain unclear. Here, we report that mice fed a high-fat diet (HFD) for as little as 1-3 days show increased differentiation of myeloid progenitors into neutrophils and monocytes but reduced B lymphocyte production in the bone marrow. Levels of neutrophil elastase (NE) and the nuclear factors CCAAT/enhancer-binding protein α (C/EBPα) and growth factor-independent 1 (GFI-1) are elevated in hematopoietic stem and progenitor cells from HFD-fed mice, but mice lacking either NE or C/EBPα are resistant to HFD-induced myelopoiesis. NE deletion increases expression of the inhibitory isoform of p30 C/EBPα, impairs the transcriptional activity of p42 C/EBPα, and reduces expression of the C/EBPα target gene GFI-1 in hematopoietic stem and progenitor cells, suggesting a mechanism by which NE regulates myelopoiesis. Furthermore, NE deletion prevents HFD-induced vascular leakage. Thus, HFD feeding rapidly activates bone marrow myelopoiesis through the NE-dependent C/EBPα-GFI-1 pathway preceding vascular damage and systemic inflammation.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Inflamação/fisiopatologia , Elastase de Leucócito/imunologia , Mielopoese , Obesidade/etiologia , Obesidade/fisiopatologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Medula Óssea/imunologia , Medula Óssea/patologia , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/imunologia , Permeabilidade Capilar , Deleção de Genes , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/patologia , Inflamação/genética , Inflamação/imunologia , Elastase de Leucócito/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/patologia , Neutrófilos/imunologia , Neutrófilos/patologia , Obesidade/genética , Obesidade/imunologiaRESUMO
Sasanquasaponin (SQS) has been reported to elicit cardioprotection by suppressing hypoxia/reoxygenation (H/R)-induced elevation of intracellular chloride ion concentration ([Cl-]i). Given that the increased [Cl-]i is involved to modulate the mitochondrial permeability transition pore (mPTP), we herein sought to further investigate the role of mPTP in the cardioprotective effect of SQS on H/R injury. H9c2 cells were incubated for 24h with or without 10µM SQS followed by H/R. The involvement of mPTP was determined with a specific mPTP agonist atractyloside (ATR). The results showed that SQS attenuated H/R-induced the elevation of [Cl-]i, accompanied by reduction of lactate dehydrogenase release and increase of cell viability. Moreover, SQS suppressed mPTP opening, and protected mitochondria, as indicated by preserved mitochondrial membrane potential and respiratory chain complex activities, decreased mitochondrial reactive oxygen species generation, and increased ATP content. Interestingly, extracellular Cl--free condition created by replacing Cl- with equimolar gluconate resulted in a decrease in [Cl-]i and induced protective effects similar to SQS preconditioning, whereas pharmacologically opening of the mPTP with ATR abolished all the protective effects induced by SQS or Cl--free, including suppression of mPTP opening, maintenance of mitochondrial membrane potential, and subsequent improvement of mitochondrial function. The above results allow us to conclude that SQS-induced cardioprotection may be mediated by preserving the mitochondrial function through preventing mPTP opening via inhibition of H/R-induced elevation of [Cl-]i.
Assuntos
Cardiotônicos/farmacologia , Cloretos/química , Citoplasma/química , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Saponinas/farmacologia , Animais , Atractilosídeo/farmacologia , Linhagem Celular , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Poro de Transição de Permeabilidade Mitocondrial , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/fisiopatologiaRESUMO
DJ1 protein, as a multifunctional intracellular protein, has been demonstrated to serve a critical role in regulating cell survival and oxidative stress. To provide in vivo evidence that DJ1 is involved in the delayed cardioprotection induced by ischemic preconditioning (IPC) against oxidative stress caused by ischemia/reperfusion (I/R), the present study subjected male SpragueDawley rats to IPC (3 cycles of 5min coronary occlusion/5min reperfusion) 24 h prior to I/R (30min coronary occlusion/120min reperfusion). A lentiviral vector containing short hairpin RNA was injected into the left ventricle three weeks prior to IPC, to knockdown DJ1 in situ. Lactate dehydrogenase (LDH) and creatine kinaseMB (CKMB) release, infarct size, cardiac function, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, malondialdehyde (MDA), intracellular reactive oxygen species (ROS), and DJ1 protein expression levels were assessed. IPC caused a significant increase in the expression levels of DJ1 protein. In addition, IPC reduced LDH and CKMB release, attenuated myocardial infarct size, improved cardiac function following I/R, and inhibited the elevation of ROS and MDA and the decrease in activities of the antioxidant enzymes SOD, CAT and GPx. However, in situ knockdown of DJ1 attenuated the IPCinduced delayed cardioprotection, and reversed the inhibitory effect of IPC on I/Rinduced oxidative stress. The present study therefore provided novel evidence that DJ1 is involved in the delayed cardioprotection of IPC against I/R injury in vivo. Notably, DJ1 is required for IPC to inhibit I/Rinduced oxidative stress.
Assuntos
Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Estresse Oxidativo , Proteína Desglicase DJ-1/genética , Animais , Precondicionamento Isquêmico Miocárdico/métodos , Masculino , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Proteína Desglicase DJ-1/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
Capsaicin (Cap) has been reported to have beneficial effects on cardiovascular system, but the mechanisms underlying these effects are still poorly understood. Apoptosis has been shown to be involved in mitochondrial dysfunction, and upregulating expression of SIRT1 can inhibit the apoptosis of cardiomyocytes induced by anoxia/reoxygenation (A/R). Therefore, the aim of this study was to test whether the protective effects of Cap against the injury to the cardiomyocytes are mediated by SIRT1. The effects of Cap with or without coadministration of sirtinol, a SIRT1 inhibitor, on changes induced by A/R in the cell viability, activities of lactate dehydrogenase (LDH), creatine phosphokinase (CPK), levels of intracellular reactive oxygen species (ROS), and mitochondrial membrane potential (MMP), related protein expression, mitochondrial permeability transition pore (mPTP) opening, and apoptosis rate in the primary neonatal rat cardiomyocytes were tested. Cap significantly increased the cell viability, upregulated expression of SIRT1 and Bcl-2, and decreased the LDH and CPK release, generation of ROS, loss of MMP, mPTP openness, activities of caspase-3, release of the cytochrome c, and apoptosis of the cardiomyocytes. Sirtinol significantly blocked the cardioprotective effects of Cap. The results suggest that the protective effects of Cap against A/R-induced injury to the cardiomyocytes are involved with SIRT1.
Assuntos
Capsaicina/farmacologia , Hipóxia Celular/efeitos dos fármacos , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Sirtuína 1/metabolismo , Animais , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias Cardíacas/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
Ferulic acid is a polyphenolic compound contained in various types of fruits and wheat bran. As a salt of the active ingredient, sodium ferulate (SF) has potent free radical scavenging activity and can effectively scavenge ROS. In this study, we examined the effect of SF on iron-overloaded mice in comparison to a standard antioxidant, taurine (TAU). We determined the protective role of SF against liver injury by examining liver-to-body ratio (%), transaminase and hepatocyte apoptosis in rats supplied with 10% dextrose intraperitoneal injection. In addition, antioxidative enzymes activities, ROS formation, mitochondrial swelling, and mitochondrial membrane potential (MMP) were all evaluated to clarify the mechanism of protective effect of SF associated with oxidative stress. After 15 weeks of SF treatment, we found a significant reduction in liver-to-body weight radio and elevation in both transaminase and hepatocyte apoptosis associated with iron-injected to levels comparable to those achieved with TAU. Both SF and TAU significantly attenuated the impaired liver function associated with iron-overloaded in mice, whereas neither showed any significant effect on the iron uptake. Furthermore, treatment with either SF or TAU in iron-overloaded mice attenuated oxidative stress, associated with elevated oxidant enzymes activities, decreased ROS production, prevented mitochondrial swelling and dissipation of MMP and then inhibited hepatic apoptosis. Taken together, the current study shows that, SF alleviated oxidative stress and liver damage associated with iron-overload conditions compared to the standard ROS scavenger (TAU), and potentially could encourage higher consumption and utilization as healthy and sustainable ingredients by the food and drink.
Assuntos
Ácidos Cumáricos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Sobrecarga de Ferro/tratamento farmacológico , Hepatopatias/prevenção & controle , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Fígado/patologia , Hepatopatias/etiologia , Hepatopatias/metabolismo , Hepatopatias/patologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Sasanquasaponin (SQS) is an active component of Camellia oleifera Abel. A recent study by our group demonstrated that SQS was able to inhibit ischemia/reperfusioninduced elevation of the intracellular chloride ion concentration ([Cl]i) and exerted cardioprotective effects; however, the underlying intracellular signal transduction mechanisms have yet to be elucidated. As protein kinase C ε (PKCε) is able to mediate Cl homeostasis, the present study investigated its possible involvement in the effects of SQS on cardiomyocytes subjected to ischemia/reperfusion injury. Cardiomyocytes were pretreated with or without SQS or SQS plus εV12, a selective PKCε inhibitor, followed by simulated ischemia/reperfusion (sI/R). The effects on cell viability, PKCε phosphorylation levels, [Cl]i, mitochondrial membrane potential and reactive oxygen species (ROS) production were assessed using an MTS assay, western blot analysis, colorimetric assays and flow cytometry. The results revealed that treatment with SQS prior to sI/R increased the viability of cardiomyocytes, and efficiently attenuated lactate dehydrogenase and creatine phosphokinase release induced by sI/R. In addition, SQS promoted PKCε phosphorylation and inhibited sI/Rinduced elevation of [Cl]i, paralleled by the attenuation of mitochondrial membrane potential loss and ROS generation. However, when the cardiomyocytes were treated with εV12 prior to SQS preconditioning, the cardioprotection induced by SQS was reduced and the inhibitory effects of SQS on sI/Rinduced elevation of [Cl]i, production of ROS and loss of mitochondrial membrane potential were also attenuated. These findings indicated that SQS may inhibit sI/Rinduced elevation of [Cl]i through the PKCε signaling pathway to elicit cardioprotection in cultured cardiomyocytes.
Assuntos
Cardiotônicos/farmacologia , Cloretos/metabolismo , Proteína Quinase C-épsilon/metabolismo , Saponinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Hipóxia Celular , Células Cultivadas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
DJ-1 protein, as a multifunctional intracellular protein, has an important role in transcriptional regulation and anti-oxidant stress. A recent study by our group showed that DJ-1 can regulate the expression of certain antioxidant enzymes and attenuate hypoxia/reoxygenation (H/R)induced oxidative stress in the cardiomyocyte cell line H9c2; however, the detailed molecular mechanisms have remained to be elucidated. Nuclear factor erythroid 2like 2 (Nrf2) is an essential transcription factor that regulates the expression of several antioxidant genes via binding to the antioxidant response element (ARE). The present study investigated whether activation of the Nrf2 pathway is responsible for the induction of antioxidative enzymes by DJ1 and contributes to the protective functions of DJ1 against H/Rinduced oxidative stress in H9c2 cells. The results demonstrated that DJ1overexpressing H9c2 cells exhibited antioxidant enzymes, including manganese superoxide dismutase, catalase and glutathione peroxidase, to a greater extent and were more resistant to H/Rinduced oxidative stress compared with native cells, whereas DJ1 knockdown suppressed the induction of these enzymes and further augmented the oxidative stress injury. Determination of the importance of Nrf2 in DJ1mediated antioxidant enzymes induction and cytoprotection against oxidative stress induced by H/R showed that overexpression of DJ1 promoted the dissociation of Nrf2 from its cytoplasmic inhibitor Keap1, resulting in enhanced levels of nuclear translocation, AREbinding and transcriptional activity of Nrf2. Of note, Nrf2 knockdown abolished the DJ1mediated induction of antioxidant enzymes and cytoprotection against oxidative stress induced by H/R. In conclusion, these findings indicated that activation of the Nrf2 pathway is a critical mechanism by which DJ-1 upregulates anti-oxidative enzymes and attenuates H/R-induced oxidative stress in H9c2 cells.
Assuntos
Proteínas Associadas aos Microtúbulos/fisiologia , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Traumatismo por Reperfusão/metabolismo , Animais , Catalase/genética , Catalase/metabolismo , Hipóxia Celular , Linhagem Celular , Indução Enzimática , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteína Desglicase DJ-1 , Ratos , Transdução de Sinais , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismoRESUMO
Mitochondria-mediated apoptosis is a critical mechanism of anoxia/ reoxygenation (A/R)-induced injury in cardiomyocytes. Kaempferol (Kae) is a natural polyphenol and a type of flavonoid, which has been demonstrated to protect myocardium against ischemia/reperfusion (I/R) injury. However, the mechanism is still not fully elucidated. We hypothesize that Kae may improve the mitochondrial function during I/R injury via a potential signal pathway. In this study, an in vitro I/R model was replicated on neonatal rat primary cardiomyocytes by A/R treatment. Cell viability was monitored by the 3-(4,5-dimethylthiazol- 2-yl)-5-(3- carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium (MTS) assay. The levels of intracellular reactive oxygen species, mitochondrial membrane potential (Δψm) and apoptosis were determined by flow cytometry. Protein expression was detected by Western Blotting. mPTP opening and the activity of caspase-3 were measured by colorimetric method. The results showed that Kae effectively enhanced the cell viability and decreased the LDH release in cardiomyocytes subjected to A/R injury. Kae reduced the A/R-induced reactive oxygen species generation, the loss of Δψm, and the release of cytochrome c from mitochondria into cytosol. Kae inhibited the A/R-stimulated mPTP opening and activation of caspase-3, and ultimate decrease in cardiomyocytes apoptosis. Furthermore, we found Kae up-regulated Human Silent Information Regulator Type 1 (SIRT1) expression, indicating SIRT1 signal pathway likely involved the cardioprotection of Kae. Sirtinol, a SIRT1 inhibitor, abolished the protective effect of Kae in cardiomyocytes subjected to A/R. Additionally, Kae significantly increased the expression of Bcl-2. Thus, we firstly demonstrate that Kae protects cardiomyocytes against A/R injury through mitochondrial pathway mediated by SIRT1.
Assuntos
Apoptose/efeitos dos fármacos , Quempferóis/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Sirtuína 1/metabolismo , Animais , Animais Recém-Nascidos , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocromos c/metabolismo , Citoproteção , Inibidores de Histona Desacetilases/farmacologia , L-Lactato Desidrogenase/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Cardíacas/enzimologia , Mitocôndrias Cardíacas/patologia , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Traumatismo por Reperfusão Miocárdica/enzimologia , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/antagonistas & inibidoresRESUMO
We have recently shown that DJ-1 is implicated in the delayed cardioprotective effect of hypoxic preconditioning (HPC) against hypoxia/reoxygenation (H/R) injury as an endogenous protective protein. This study aims to further investigate the underlying mechanism by which DJ-1 mediates the delayed cardioprotection of HPC against H/R-induced oxidative stress. Using a well-characterized cellular model of HPC from rat heart-derived H9c2 cells, we found that HPC promoted nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein-1 (Keap1) dissociation and resulted in increased nuclear translocation, antioxidant response element-binding, and transcriptional activity of Nrf2 24 hours after HPC, with subsequent upregulation of manganese superoxide dismutase (MnSOD) and heme oxygenase-1 (HO-1), which provided delayed protection against H/R-induced oxidative stress in normal H9c2 cells. However, the aforementioned effects of HPC were abolished in DJ-1-knockdown H9c2 cells, which were restored by restoration of DJ-1 expression. Importantly, we showed that inhibition of the Nrf2 pathway in H9c2 cells mimicked the effects of DJ-1 knockdown and abolished HPC-derived induction of antioxidative enzymes (MnSOD and HO-1) and the delayed cardioprotection. In addition, inhibition of Nrf2 also reversed the effects of restored DJ-1 expression on induction of antioxidative enzymes and delayed cardioprotection by HPC in DJ-1-knockdown H9c2 cells. Taken together, this work revealed that activation of Nrf2 pathway and subsequent upregulation of antioxidative enzymes could be a critical mechanism by which DJ-1 mediates the delayed cardioprotection of HPC against H/R-induced oxidative stress in H9c2 cells.
Assuntos
Antioxidantes/metabolismo , Proteínas Associadas aos Microtúbulos/fisiologia , Miócitos Cardíacos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Regulação para Cima/fisiologia , Animais , Hipóxia Celular/fisiologia , Linhagem Celular , Técnicas de Silenciamento de Genes/métodos , Humanos , Precondicionamento Isquêmico Miocárdico/métodos , Proteína Desglicase DJ-1 , Ratos , Transdução de Sinais/fisiologiaRESUMO
SCOPE: This study elucidates the effects of long-term nutritional preconditioning by resveratrol on ischemia/reperfusion (I/R) injury and its underlying mechanisms. METHODS AND RESULTS: Mice were treated with resveratrol at 2.0 mg/kg/day by gastric gavages for 6 wk. Then hearts were isolated and subjected to I/R injury in a Langendorff apparatus. Resveratrol significantly improved left ventricular pressure, ±dp/dtmax, and coronary flow; decreased the lactate dehydrogenase and creatine phosphokinase activities; and reduced the infarction size. Additionally, long-term oral resveratrol intake prevented mitochondrial permeability transition pore opening and subsequently inhibited mitochondria-mediated apoptosis, as demonstrated by decrease of cytochrome c release, inactivation of caspase-3, and reduction of terminal deoxynucleotidyl transferase mediated nick end labeling positive cells. Furthermore, resveratrol inhibited the upregulation of voltage-dependent anion channel 1 (VDAC1) expression induced by I/R injury. Local left-ventricle overexpression of VDAC1 by adenovirus diminished the protective effect of resveratrol against I/R injury, indicating that VDAC1 plays an important role in resveratrol-mediated cardioprotection. CONCLUSION: Our data revealed that long-term oral intake of resveratrol sets nutritional preconditioning to cope with myocardial I/R injury. Strikingly, we found that resveratrol downregulates VDAC1, leading to prevention of mitochondrial permeability transition pore opening and cardiomyocyte apoptosis.
Assuntos
Cardiotônicos/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Estilbenos/farmacologia , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Cardiotônicos/administração & dosagem , Caspase 3/metabolismo , Citocromos c/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação da Expressão Gênica , Coração/efeitos dos fármacos , Precondicionamento Isquêmico Miocárdico/métodos , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Técnicas de Cultura de Órgãos , Resveratrol , Estilbenos/administração & dosagem , Canal de Ânion 1 Dependente de Voltagem/genéticaRESUMO
We previously demonstrated that iron overload induces liver damage by causing the formation of reactive oxygen species (ROS). Taurine is a potent free radical scavenger that attenuates the damage caused by excessive oxygen free radicals. Therefore, the aim of the present study was to investigate whether taurine could reduce the hepatotoxicity of iron overload with regard to ROS production. Mice were intraperitoneally injected with iron 5 days/week for 13 weeks to achieve iron overload. It was found that iron overload resulted in liver dysfunction, increased apoptosis and elevated oxidative stress. Taurine supplementation increased liver taurine levels by 40% and led to improved liver function, as well as a reduction in apoptosis, ROS formation and mitochondrial swelling and an attenuation in the loss of the mitochondrial membrane potential. Treatment with taurine mediated a reduction in oxidative stress in ironoverloaded mice, attenuated liver lipid peroxidation, elevated antioxidant enzyme activities and maintained reduced glutathione levels. These results indicate that taurine reduces ironinduced hepatic oxidative stress, preserves liver function and inhibits hepatocyte apoptosis. Therefore, taurine may be a potential therapeutic drug to reduce liver damage caused by iron overload.