RESUMO
Mitochondrial dysfunctions are responsible for myocardial injury upon ischemia/reperfusion (I/R), and mitochondrial E3 ubiquitin ligase 1 (Mul1) plays an important role in maintaining mitochondrial functions. This study aims to explore the function of Mul1 in myocardial I/R injury and the underlying mechanisms. The Sprague-Dawley rat hearts were subjected to 1 h of ischemia plus 3 h of reperfusion, which showed the I/R injury (increase in infarct size and creatine kinase release) and the elevated total and mitochondrial protein levels of Mul1 and p53 accompanied by the enhanced interactions between Mul1 and p53 as well as p53 and small a ubiquitin-like modifier (SUMO1). Consistently, hypoxia/reoxygenation (H/R) treated cardiac (H9c2) cells displayed cellular injury (apoptosis and necrosis), upregulation of total and mitochondrial protein levels of Mul1 and p53, and enhanced interactions between p53 and SUMO1 concomitant with mitochondrial dysfunctions (an increase in mitochondrial membrane potential and reactive oxygen species production with a decrease in ATP production); these phenomena were attenuated by knockdown of Mul1 expression. Based on these observations, we conclude that a novel role of Mul1 has been identified in the myocardial mitochondria, where Mul1 stabilizes and activates p53 through its function of SUMOylation following I/R, leading to p53-mediated mitochondrial dysfunction and cell death.
Assuntos
Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Regulação para Cima , Trifosfato de Adenosina/metabolismo , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Masculino , Potencial da Membrana Mitocondrial , Proteínas Mitocondriais/deficiência , Proteínas Mitocondriais/genética , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genéticaRESUMO
PURPOSE: Necroptosis is an important form of cell death following myocardial ischemia/reperfusion (I/R) and phosphoglycerate mutase 5 (PGAM5) functions as the convergent point for multiple necrosis pathways. This study aims to investigate whether inhibition of PGAM5 could reduce I/R-induced myocardial necroptosis and the underlying mechanisms. METHODS: The SD rat hearts (or H9c2 cells) were subjected to 1-h ischemia (or 10-h hypoxia) plus 3-h reperfusion (or 4-h reoxygenation) to establish the I/R (or H/R) injury model. The myocardial injury was assessed by the methods of biochemistry, H&E (hematoxylin and eosin), and PI/DAPI (propidium iodide/4',6-diamidino-2-phenylindole) staining, respectively. Drug interventions or gene knockdown was used to verify the role of PGAM5 in I/R (or H/R)-induced myocardial necroptosis and possible mechanisms. RESULTS: The I/R-treated heart showed the injuries (increase in infarct size and creatine kinase release), upregulation of PGAM5, dynamin-related protein 1 (Drp1), p-Drp1-S616, and necroptosis-relevant proteins (RIPK1/RIPK3, receptor-interacting protein kinase 1/3; MLKL, mixed lineage kinase domain-like); these phenomena were attenuated by inhibition of PGAM5 or RIPK1. In H9c2 cells, H/R treatment elevated the levels of PGAM5, RIPK1, RIPK3, MLKL, Drp1, and p-Drp1-S616 and induced mitochondrial dysfunctions (elevation in mitochondrial membrane potential and ROS level) and cellular necrosis (increase in LDH release and the ratio of PI+/DAPI+ cells); these effects were blocked by inhibition or knockdown of PGAM5. CONCLUSIONS: Inhibition of PGAM5 can reduce necroptosis in I/R-treated rat hearts through suppression of Drp1; there is a positive feedback between RIPK1 and PGAM5, and PGAM5 might serve as a novel therapeutic target for prevention of myocardial I/R injury.
Assuntos
DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Inibidores Enzimáticos/farmacologia , Glicolatos/farmacologia , Proteínas Mitocondriais/antagonistas & inibidores , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Fosfoglicerato Mutase/antagonistas & inibidores , Fosfoproteínas Fosfatases/antagonistas & inibidores , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Modelos Animais de Doenças , Regulação para Baixo , Masculino , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/enzimologia , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Fosfoglicerato Mutase/genética , Fosfoglicerato Mutase/metabolismo , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ratos Sprague-Dawley , Proteína Serina-Treonina Quinases de Interação com Receptores , Transdução de Sinais/efeitos dos fármacosRESUMO
Right ventricle (RV) remodeling is a major pathological feature in pulmonary arterial hypertension (PAH). Magnesium lithospermate B (MLB) is a compound isolated from the roots of Salvia miltiorrhiza and it possesses multiple pharmacological activities such as anti-inflammation and antioxidation. This study aims to investigate whether MLB is able to prevent RV remodeling in PAH and the underlying mechanisms. In vivo, SD rats were exposed to 10% O2 for 21 d to induce RV remodeling, which showed hypertrophic features (increases in the ratio of RV weight to tibia length, cellular size, and hypertrophic marker expression), accompanied by upregulation in expression of NADPH oxidases (NOX2 and NOX4) and vascular peroxidase 1 (VPO1), increases in hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) production and elevation in phosphorylation levels of ERK; these changes were attenuated by treating rats with MLB. In vitro, the cultured H9c2 cells were exposed to 3% O2 for 24 h to induce hypertrophy, which showed hypertrophic features (increases in cellular size and hypertrophic marker expression). Administration of MLB or VAS2870 (a positive control for NOX inhibitor) could prevent cardiomyocyte hypertrophy concomitant with decreases in NOX (NOX2 and NOX4) and VPO1 expression, H2O2 and HOCl production, and ERK phosphorylation. Based on these observations, we conclude that MLB is able to prevent RV remodeling in hypoxic PAH rats through a mechanism involving a suppression of NOX/VPO1 pathway as well as ERK signaling pathway. MLB may possess the potential clinical value for PAH therapy.
Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Hemeproteínas/metabolismo , Hipertensão Pulmonar/fisiopatologia , NADPH Oxidases/metabolismo , Peroxidases/metabolismo , Salvia miltiorrhiza/química , Remodelação Ventricular/efeitos dos fármacos , Animais , Fator Natriurético Atrial/genética , Benzoxazóis/farmacologia , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/isolamento & purificação , Hemeproteínas/antagonistas & inibidores , Hipertensão Pulmonar/metabolismo , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , NADPH Oxidase 2/metabolismo , NADPH Oxidase 4/metabolismo , NADPH Oxidases/antagonistas & inibidores , Peptídeo Natriurético Encefálico/genética , Peroxidases/antagonistas & inibidores , Ratos Sprague-Dawley , Triazóis/farmacologiaRESUMO
To study the effect and mechanism of Dendrobium candidum on isoproterenol-induced myocardial hypertrophy in rats, 60 healthy SD rats(30 males and 30 females) were randomly divided into 5 groups(12 in each group): normal group, model group, three D. candidum preventive administration groups(0.09, 0.18, 1.1 g·kg⻹). Except for the normal group, rats of other groups were injected back subcutaneously with ISO(5 mg·kg⻹) for 10 consecutive days. At the same time, preventive administration groups began to give different doses of the sample for 30 days and model group began to give normal saline. Left ventricular systolic pressure(LVSP) was measured in each group by common carotid artery cannulation, and the left ventricle(LW)/tibia length, heart weight index(HWI) and myocardial hydroxyproline(Hydro) content were calculated. Myocardial tissue HE staining and Masson staining were used to observe the myocardial structure and the degree of myocardial fibrosis respectively. Atrial natriuretic peptide(ANP), brain natriuretic peptide(BNP), and cardiac troponin I(cTN-I) concentration were measured by enzyme-linked immunosorbent assay(ELISA). The results showed that as compared with the normal group, the levels of ANP, BNP and cTN-I in plasma were significantly increased in ISO-induced hypertrophic rats; as compared with the model group, D. candidumcan inhibit ISO-induced ventricular pressure and ventricular hypertrophy, reduce myocardial collagen synthesis, improve myocardial fibrosis and ventricular remodeling, and significantly down-regulate ANP, BNP and cTN-I levels in plasma. This study shows that D. candidum has a protective effect on isoproterenol-induced cardiac hypertrophy.
Assuntos
Cardiomegalia/tratamento farmacológico , Dendrobium/química , Medicamentos de Ervas Chinesas/farmacologia , Miocárdio/patologia , Animais , Feminino , Isoproterenol , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Microvascular complications are the leading causes of acquired blindness, end-stage renal failure, and varieties of neuropathy associated with diabetes. Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is involved in endothelial dysfunction, oxidative stress, and inflammation associated with the progression of diabetic microvascular complications. Elevated ADMA has been detected in experimental animals and patients with diabetic microangiopathy like retinopathy, nephropathy, and neuropathy. In the review, we focus on the role of ADMA in the pathobiology of major microvascular complications of diabetes.
Assuntos
Arginina/análogos & derivados , Diabetes Mellitus/metabolismo , Angiopatias Diabéticas/metabolismo , Animais , Arginina/metabolismo , Biomarcadores/metabolismo , Diabetes Mellitus/patologia , Angiopatias Diabéticas/patologia , Inibidores Enzimáticos/metabolismo , Humanos , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismoRESUMO
Impaired endothelium-dependent vasodilation in atherosclerosis is a high-risk factor for myocardial infarction and ischemic stroke, and inflammation, necroptosis and apoptosis contribute to endothelial dysfunction in atherosclerosis. Although DL-3-n-butylphthalide (NBP) has been widely used in treating ischemic stroke, its effect on endothelium-dependent vasodilation remains unknown. This study aims to explore whether NBP is able to improve endothelium-dependent vasodilation in atherosclerosis and the underlying mechanisms. Male ApoE-/- mice were fed with a high-fat diet (HFD) for 9-16 weeks to establish a model of atherosclerosis. NBP were given to the mice after eating HFD for 6 weeks and atorvastatin served as a positive control. The endothelium-dependent vasodilation, the blood flow velocity, the atherosclerotic lesion area, the serum levels of lipids, inflammatory cytokines and necroptosis-relevant proteins (RIPK1, RIPK3 and MLKL), and the endothelial necroptosis and apoptosis within the aorta were measured. Human umbilical vein endothelial cells (HUVECs) were incubated with oxidized low-density lipoprotein (ox-LDL) for 48 h to mimic endothelial injury in atherosclerosis, lactate dehydrogenase release, the ratio of necroptosis and apoptosis and the expression of necroptosis-relevant proteins were examined. Similar to atorvastatin, NBP improves endothelium-dependent vasodilation, decreases aortic flow velocity and reduces atherosclerotic lesion area in HFD-fed ApoE-/- mice, concomitant with a reduction in serum lipids, inflammatory cytokines and necroptosis-relevant proteins, and endothelial necroptosis and apoptosis. Consistently, NBP inhibited necroptosis and apoptosis in ox-LDL-treated HUVECs. Based on these observations, we conclude that NBP exerts beneficial effects on improving the endothelium-dependent vasodilation in atherosclerosis via suppressing inflammation, endothelial necroptosis and apoptosis.
Assuntos
Aterosclerose , AVC Isquêmico , Masculino , Humanos , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Vasodilatação , Atorvastatina/farmacologia , Necroptose , Aterosclerose/metabolismo , Células Endoteliais da Veia Umbilical Humana , Inflamação/metabolismo , Endotélio/metabolismo , Citocinas/metabolismo , AVC Isquêmico/metabolismo , Apoptose , Apolipoproteínas E/genética , Camundongos KnockoutRESUMO
The dysregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and/or solute carrier family 7 member 11 (SLC7A11) is believed to contribute to ferroptosis in the hearts suffered ischemia/reperfusion (I/R), but the mechanisms behind the dysregulation of them are not fully elucidated. Mucosa associated lymphoid tissue lymphoma translocation gene 1 (MALT1) can function as a paracaspase to cleave specified substrates and it is predicted to interact with Nrf2. This study aims to explore whether targeting MALT1 can reduce I/R-induced ferroptosis via enhancing the Nrf2/SLC7A11 pathway. The SD rat hearts were subjected to 1h-ischemia plus 3h-reperfusion to establish the I/R injury model, which showed myocardial injuries (increase in infarct size and creatine kinase release) and up-regulation of MALT1 while downregulation of Nrf2 and SLC7A11 concomitant with the increased ferroptosis, reflecting by an increase in glutathione peroxidase 4 (GPX4) level while decreases in the levels of acyl-CoA synthetase long chain family member 4 (ACSL4), total iron, Fe2+ and lipid peroxidation (LPO); these phenomena were reversed in the presence of MI-2, a specific inhibitor of MALT1. Consistently, similar results were achieved in the cultured cardiomyocytes subjected to 8h-hypoxia plus 12h-reoxygenation. Furthermore, micafungin, an antifungal drug, could also exert beneficial effect on mitigating myocardial I/R injury via inhibition of MALT1. Based on these observations, we conclud that inhibition of MALT1 can reduce I/R-induced myocardial ferroptosis through enhancing the Nrf2/SLC7A11 pathway; and MALT1 may be used as a potential target to seek novel or existing drugs (such as micafungin) for treating myocardial infarction.
Assuntos
Ferroptose , Traumatismo por Reperfusão Miocárdica , Traumatismo por Reperfusão , Animais , Ratos , Isquemia , Micafungina , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Fator 2 Relacionado a NF-E2 , Ratos Sprague-Dawley , ReperfusãoRESUMO
Vascular peroxidase 1 (VPO1) can utilize reactive oxygen species (ROS) generated from NADPH oxidase (NOX) to catalyze peroxidative reactions. This study was performed to identify a novel pathway of NOX/VPO1 in mediating the oxidative injury following myocardial ischemia reperfusion (IR). In a rat model of myocardial IR, the infarct size, serum creatine kinase (CK) activity, apoptosis, NOX activity, NOX2 and VPO1 expression were measured. In a cell (rat heart-derived H9c2 cells) model of hypoxia/reoxygenation (HR), the apoptosis, NOX activity, NOX2 and VPO1 expression, and H(2)O(2) and HOCl levels were examined. In vivo, IR caused 54.8 ± 1.7 % infarct size in myocardium accompanied by elevated activities of CK, caspase-3 and NOX, up-regulated VPO1 expression and high numbers of myocardial apoptotic cells; these effects were attenuated by pretreatment with the inhibitor of NOX. In vitro, inhibition of NOX or silencing of NOX2 or VPO1 expression significantly suppressed HR-induced cellular apoptosis concomitantly with decreased HOCl production. Inhibition of NOX or silencing of NOX2 led to a decrease in H(2)O(2) production accompanied by a decrease in VPO1 expression and HOCl production. However, silencing of VPO1 expression did not affect NOX2 expression and H(2)O(2) production. H(2)O(2)-induced VPO1 expression was partially reversed by JNK or p38 MAPK inhibitor. Our results demonstrate a novel pathway of NOX2/VPO1 in myocardium, where VPO1 coordinates with NOX2 and amplifies the role of NOX-derived ROS in oxidative injury following IR.
Assuntos
Hemeproteínas/metabolismo , Glicoproteínas de Membrana/metabolismo , Infarto do Miocárdio/enzimologia , Traumatismo por Reperfusão Miocárdica/enzimologia , Miocárdio/enzimologia , NADPH Oxidases/metabolismo , Estresse Oxidativo , Peroxidases/metabolismo , Transdução de Sinais , Animais , Apoptose , Caspase 3/metabolismo , Linhagem Celular , Creatina Quinase/sangue , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Hemeproteínas/genética , Peróxido de Hidrogênio/metabolismo , Ácido Hipocloroso/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/genética , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/genética , Estresse Oxidativo/efeitos dos fármacos , Peroxidases/genética , Interferência de RNA , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transfecção , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Capsiate is a non-pungent analogue of capsaicin from CH-19 Sweet peppers. Capsaicin is reported to trigger calcitonin gene-related peptide (CGRP) release through activation of transient receptor potential vanilloid subfamily member 1 (TRPV1) and produces beneficial effects on gastric mucosa. This study aimed to investigate whether capsiate is able to produce beneficial effects on gastric mucosa and whether the protective effects of capsipate occur through a mechanism involving the activation of TRPV1 and CGRP release. A rat model of gastric mucosal injury was established by the oral administration of acidified ethanol. Gastric tissues were collected for analysis of the gastric ulcer index, cellular apoptosis, activities of caspase-3, catalase and superoxide dismutase (SOD), and levels of CGRP, TNF-α, and malondialdehyde (MDA). Our results show that the acute administration of ethanol significantly increased the gastric ulcer index concomitantly with an increase in cellular apoptosis, caspase-3 activity, and TNF-α and MDA levels, as well as a decrease in the activities of catalase and SOD. Pretreatment with 1 mg/kg capsiate attenuated ethanol-induced gastric mucosal injury and cellular apoptosis accompanied by an increase in CGRP level, catalase, and SOD activities, and a decrease in caspase-3 activity, and TNF-α and MDA levels. The effects of capsiate were inhibited by capsazepine, an antagonist of TRPV1. These results suggest that capsiate is able to produce beneficial effects on ethanol-induced gastric mucosal injury. These effects are related to the stimulation of CGRP release through the activation of TRPV1.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Capsaicina/análogos & derivados , Capsicum/química , Mucosa Gástrica/efeitos dos fármacos , Fitoterapia , Úlcera Gástrica/tratamento farmacológico , Canais de Cátion TRPV/metabolismo , Animais , Apoptose/efeitos dos fármacos , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Caspase 3/metabolismo , Modelos Animais de Doenças , Etanol , Mucosa Gástrica/metabolismo , Fármacos Gastrointestinais/farmacologia , Fármacos Gastrointestinais/uso terapêutico , Masculino , Malondialdeído/sangue , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
AIMS: Vascular peroxidase 1 (VPO1) plays an important role in mediation of vascular remodeling with pulmonary arterial hypertension (PAH). This study aims to determine whether VPO1 can promote phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) and the underlying mechanisms. MAIN METHODS: Sprague-Dawley (SD) rats were exposed to 10 % O2 for 21 days to establish the model of vascular remodeling in pulmonary arterial hypertension. PASMCs were incubated with 3 % O2 for 48 h to induce phenotypic transformation. Western blot was performed to detect the expressions of target proteins. The 5-ethynyl-2'-deoxyuridine (EdU) assay was conducted to measure the proliferation of PASMCs. KEY FINDINGS: In the rats exposed to hypoxia, there were increases in right ventricular systolic pressure, pulmonary vascular remodeling and phenotypic transformation of PASMCs (the down-regulated contractile proteins of α-smooth muscle actin, smooth muscle 22α while the up-regulated synthetic proteins of osteopontin, cyclinD1), accompanied by up-regulation of VPO1, increase of hypochlorous acid (HOCl) production and elevation of the phosphorylation of ERK. In the cultured PASMCs exposed to hypoxia, similar results were achieved but they were reversed by VPO1 small interfering RNA (VPO1 siRNA) or HOCl inhibitor. Replacement of hypoxia with NaOCl could induce PASMCs phenotypic transformation and activate the ERK signaling. Furthermore, ERK inhibitor (PD98059) could also attenuate hypoxia-induced PASMCs phenotypic transformation. SIGNIFICANCE: VPO1 play a pivotal role in promotion of phenotypic transformation of PASMCs under hypoxic condition through activation of VPO1/HOCl/ERK pathway. It might serve as a potential target for prevention of pulmonary vascular remodeling.
Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Actinas/metabolismo , Animais , Proliferação de Células , Células Cultivadas , Hipertensão Pulmonar Primária Familiar , Hemeproteínas , Hipertensão Pulmonar/metabolismo , Ácido Hipocloroso/metabolismo , Hipóxia , Sistema de Sinalização das MAP Quinases , Miócitos de Músculo Liso/metabolismo , Osteopontina/metabolismo , Peroxidases/metabolismo , Artéria Pulmonar/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Remodelação Vascular/fisiologiaRESUMO
1. It has been shown that phloroglucinol has anti-inflammatory and anti-oxidant properties. Both inflammatory cell infiltration and myeloperoxidase (MPO) activation play an important role in myocardial reperfusion injury. The aim of the present study was to explore the effect of phloroglucinol on myocardial reperfusion injury and the mechanisms involved. 2. Anaesthetized rats were pretreated with phloroglucinol (15 or 30 mg/kg, i.g.) or vehicle (5 mmol/L carboxymethyl cellulose sodium) 30 min prior to experimentation. The left main coronary artery was subjected to 1 h occlusion followed by 3 h reperfusion. Infarct size, the release of creatine kinase (CK), inflammatory cell infiltration, MPO activity and protein content, catalase in the blood and myocardium, and myocardial apoptosis were measured. 3. Following myocardial ischaemia and reperfusion in vehicle-treated rats, infarct size was 43.5 ± 3.7% (relative to the area at risk). Accompanying detrimental changes included elevated CK, enhanced inflammatory cell infiltration, high numbers of myocardial apoptotic cells, elevated caspase 3 activity, increased MPO activity and content in the plasma and myocardium and reduced catalase activity. These effects were attenuated by pretreatment with both doses of phloroglucinol (15 and 30 mg/kg, i.g.). 4. The results of the present study suggest that phloroglucinol protects the myocardium against ischaemia-reperfusion injury in rats and that its beneficial effects are related to inhibition of MPO activity and inflammatory cell infiltration.
Assuntos
Traumatismo por Reperfusão Miocárdica/prevenção & controle , Infiltração de Neutrófilos/efeitos dos fármacos , Peroxidase/antagonistas & inibidores , Floroglucinol/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Cardiotônicos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Inflamação/imunologia , Masculino , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/imunologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Infiltração de Neutrófilos/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
Allopurinol, a xanthine oxidase (XO) inhibitor, is reported to alleviate myocardial ischemia/reperfusion (I/R) injury by reducing the production of reactive oxygen species (ROS). As an XO-derived product, H2O2 can act as a substrate of vascular peroxidase 1 (VPO1) to induce the generation of hypochlorous acid (HOCl), a potent oxidant. This study aims to explore whether the XO/VPO1 pathway is involved in the anti-oxidative effects of allopurinol on the myocardial I/R injury. In a rat heart model of I/R, allopurinol alleviated I/R oxidative injury accompanied by decreased XO activity, XO-derived products (H2O2 and uric acid), and VPO1 expression (mRNA and protein). In a cardiac cell model of hypoxia/reoxygenation (H/R), allopurinol or XO siRNA reduced H/R injury concomitant with decreased XO activity, VPO1 expression as well as the XO and VPO1-derived products (H2O2, uric acid, and HOCl). Although knockdown of VPO1 could also exert a beneficial effect on H/R injury, it did not affect XO activity, XO expression, and XO-derived products. Based on these observations, we conclude that the novel pathway of XO/VPO1 is responsible for, at least partly, myocardial I/R-induced oxidative injury, and allopurinol exerted the cardioprotective effects on myocardial I/R injury via inhibiting the XO/VPO1 pathway.
Assuntos
Alopurinol , Xantina Oxidase , Animais , Peróxido de Hidrogênio , RatosRESUMO
Ferroptosis is an iron-dependent regulated necrosis. This study aims to evaluate the contribution of ferroptosis to ischemia or reperfusion injury, and lay a basis for precise therapy of myocardial infarction. The Sprague-Dawley (SD) rat hearts were subjected to ischemia for different duration or the hearts were treated with 1 h-ischemia plus different duration of reperfusion. The myocardial injury was assessed by biochemical assays and hematoxylin & eosin (HE) staining. The ferroptosis was evaluated with the levels of acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), iron, and malondialdehyde. Iron chelator (deferoxamine) was applied to verify the contribution of ferroptosis to ischemia and reperfusion injury. The results showed that ischemic injury (infarction and CK release) was getting worse with the extension of ischemia, but no significant changes in ferroptosis indexes (ACSL4, GPX4, iron, and malondialdehyde) in cardiac tissues were observed. Differently, the levels of ACSL4, iron, and malondialdehyde were gradually elevated with the extension of reperfusion concomitant with a decrease of GPX4 level. In the ischemia-treated rat hearts, no significant changes in myocardial injury were observed in the presence of deferoxamine, while in the ischemia/reperfusion-treated rat hearts, myocardial injury was markedly attenuated in the presence of deferoxamine concomitant with a reduction of ferroptosis. Based on these observations, we conclude that ferroptosis occurs mainly in the phase of myocardial reperfusion but not ischemia. Thus, intervention of ferroptosis exerts beneficial effects on reperfusion injury but not ischemic injury, laying a basis for precise therapy for patients with myocardial infarction.
Assuntos
Ferroptose , Isquemia , Traumatismo por Reperfusão Miocárdica , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Coenzima A Ligases/metabolismo , Creatina Quinase/sangue , Desferroxamina/farmacologia , Ferro/metabolismo , Isquemia/metabolismo , Masculino , Malondialdeído/metabolismo , Traumatismo por Reperfusão Miocárdica/sangue , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Ratos Sprague-Dawley , Sideróforos/farmacologiaRESUMO
Iron overload triggers the ferroptosis in the heart following ischemia/reperfusion (I/R) and transferrin receptor 1 (TfR1) charges the cellular iron uptake. Bioinformatics analysis shows that the three molecules of ubiquitin-specific protease 7 (USP7), p53 and TfR1 form a unique pathway of USP7/p53/TfR1. This study aims to explore whether USP7/p53/TfR1 pathway promotes ferroptosis in rat hearts suffered I/R and the underlying mechanisms. The SD rat hearts were subjected to 1 h-ischemia plus 3 h-reperfusion, showing myocardial injury (increase in creatine kinase release, infarct size, myocardial fiber loss and disarray) and up-regulation of USP7, p53 and TfR1 concomitant with an increase of ferroptosis (reflecting by accumulation of iron and lipid peroxidation while decrease of glutathione peroxidase activity). Inhibition of USP7 activated p53 via suppressing deubiquitination, which led to down-regulation of TfR1, accompanied by the decreased ferroptosis and myocardial I/R injury. Next, H9c2 cells underwent hypoxia/reoxygenation (H/R) in vitro to mimic the myocardial I/R model in vivo. Consistent with the results in vivo, inhibition or knockdown of USP7 reduced the H/R injury (decrease of LDH release and necrosis) and enhanced the ubiquitination of p53 along with the decreased levels of p53 and TfR1 as well as the attenuated ferroptosis (manifesting as the decreased iron content and lipid peroxidation while the increased GPX activity). Knockdown of TfR1 inhibited H/R-induced ferroptosis without p53 deubiquitination. Based on these observations, we conclude that a novel pathway of USP7/p53/TfR1 has been identified in the I/R-treated rat hearts, where up-regulation of USP7promotes ferrptosis via activation of the p53/TfR1 pathway.
Assuntos
Ferroptose , Coração , Peptidase 7 Específica de Ubiquitina/genética , Animais , Isquemia , Ratos , Ratos Sprague-Dawley , Receptores da Transferrina , Reperfusão , Proteína Supressora de Tumor p53/genéticaRESUMO
Endothelial cell dysfunction is a prominent feature of diabetic cardiovascular complications, and endothelial cell senescence is considered to be an important contributor to endothelial dysfunction. Discoidin domain receptor 1 (DDR1) has been reported to be involved in atherogenesis and cerebral ischemia/reperfusion injury. In this study, we aimed to explore the role of DDR1 in endothelial cell senescence under diabetic conditions and elucidate the underlying mechanisms. A diabetic rat model was established by a single intraperitoneal injection of streptozocin (STZ) (60 mg/kg), which showed an increase in senescence-associated ß-galactosidase (SA-ß-gal) staining signal of thoracic aortic endothelium, impaired vascular structure and function, accompanied by an up-regulation of DDR1. Next, we verified the role of DDR1 in endothelial senescence and the underlying mechanisms in high glucose-treated human umbilical vein endothelial cells (HUVECs). Consistent with the in vivo findings, high glucose induced endothelial senescence, impaired endothelial function and elevated DDR1 expression, accompanied by the elevation of senescence-related genes p53 and p21 expression, and these effects were reversed by DDR1 siRNA. DDR1 has been documented to be a potential target of miR-199a-3p. Here, we found that miR-199a-3p was down-regulated by high glucose in the aorta tissue and HUVECs, while miR-199a-3p mimic significantly suppressed increased endothelial senescence and elevated DDR1 induced by high glucose. In conclusion, our data demonstrated that miR-199a-3p/DDR1/p53/p21 signaling pathway was involved in endothelial senescence under diabetic conditions, and therapeutic targeting DDR1 would be exploited to inhibit endothelial senescence owing to high glucose exposure.
Assuntos
Receptor com Domínio Discoidina 1 , MicroRNAs , Animais , Senescência Celular , Células Endoteliais da Veia Umbilical Humana , Humanos , Ratos , Transdução de SinaisRESUMO
RIPK1/RIPK3/MLKL (Receptor-interacting protein kinase 1/Receptor-interacting protein kinase 3/Mixed lineage kinase domain-like protein) pathway-mediated necroptosis contributes to myocardial ischemia/reperfusion (I/R) injury, and Arctiin can prevent myocardial fibrosis and hypertrophy. This study aims to explore the effect of Arctiin on myocardial I/R injury and the underlying mechanisms. SD rat hearts or cardiomyocytes were subjected to I/R or hypoxia/reoxygenation (H/R) to establish the I/R or H/R injury model. The methods of biochemistry, PI/DAPI (propidium iodide/4',6-Diamidino-2-Phenylindole) and H&E (Hematoxylin & eosin) staining were used to evaluate the I/R or H/R injury. The effects of Arctiin on necroptosis in I/R-treated hearts or H/R-treated cardiomyocytes were assessed. The results showed that Arctiin reduced myocardial I/R injury (decreases in myocardial infarction and creatine kinase release), concomitant with a decrease in levels of necroptosis-associated proteins (RIPK1/p-RIPK1, RIPK3/p-RIPK3 and MLKL/p-MLKL) in I/R-treated rat hearts. Consistently, the necrosis and LDH release in H/R-treated cardiomyocytes were attenuated in the presence of Arctiin, accompanied by suppression of necroptosis-relevant proteins. Furthermore, H/R-induced reactive oxygen species (ROS) generation and mitochondrial dysfunctions (increase in mitochondrial membrane potential and decrease in ATP production) were impaired by Arctiin. Using the program of the Molecular Operating Environment (MOE), we predict that RIPK1 and MLKL (but not RIPK3) might be the potential targets of Arctiin. Based on these observations, we conclude that Arctiin can protect the rat heart from I/R injury, and its beneficial effect is related to reduction of necroptosis via scavenging reactive oxygen species and restoring mitochondrial functions or targeting RIPK1 and/or MLKL.
Assuntos
Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Furanos/farmacologia , Glucosídeos/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Necroptose/efeitos dos fármacos , Animais , Cardiotônicos/uso terapêutico , Linhagem Celular , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/uso terapêutico , Furanos/uso terapêutico , Glucosídeos/uso terapêutico , Humanos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores , Transdução de Sinais/efeitos dos fármacosRESUMO
Magnesium lithospermate B (MLB) shows multiple biological activities including anti-oxidation and anti-proliferation in various diseases. However, the function of MLB in pulmonary arterial hypertension (PAH) is still unknown. This study aims to investigate the effect of MLB on hypoxia-induced phenotypic transformation of pulmonary arterial smooth muscle cells (PASMCs) and the underlying mechanisms. SD rats (or PASMCs) were exposed to 10% O2 for 3 weeks (or 3% O2 for 48â¯h) along with MLB or NADPH oxidase ï¼NOXï¼ inhibitor intervention. The effects of MLB on hemodynamics, pulmonary vascular remodeling and phenotypic transformation of PASMCs were observed first. Then, its effects on the protein levels of NOX (NOX2 and NOX4), ERK and p-ERK were examined. The results showed that MLB prevented the elevation in right ventricular systolic pressure and the increase in ratio of wall thickness to vessel external diameter of pulmonary arteries in PAH rats, and attenuated phenotypic transformation of PASMCs (decrease in α-smooth muscle actin while increase in osteopontin), accompanied by downregulation of NOX (NOX2 and NOX4) protein levels, decrease of ROS and H2O2 production, and suppression of the phosphorylation of ERK. NOX inhibitor (VAS2870) achieved similar results to that of MLB did in the hypoxia-treated PASMCs. Based on the observations, we conclude that MLB is able to prevent phenotypic transformation of pulmonary arteries in hypoxic PAH rats through suppression of NOX/ROS/ERK pathway, and MLB might have the potentials in PAH therapy.
Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Hipertensão Pulmonar/tratamento farmacológico , Hipóxia/tratamento farmacológico , Magnésio/farmacologia , NADPH Oxidases/metabolismo , Artéria Pulmonar/efeitos dos fármacos , Animais , Linhagem Celular , Peróxido de Hidrogênio/metabolismo , Hipertensão Pulmonar/metabolismo , Hipóxia/metabolismo , Masculino , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Fosforilação/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Remodelação Vascular/efeitos dos fármacosRESUMO
Mitochondrial dysfunctions contribute to brain injury in ischemic stroke while disturbance of mitochondrial dynamics results in mitochondrial dysfunction. Mitochondrial E3 ubiquitin ligase 1 (Mul1) involves in regulation of mitochondrial fission and fusion. This study aims to explore whether Mul1 contributes to brain injury in ischemic stroke and the underlying mechanisms. First, a rat ischemic stroke model was established by middle cerebral artery occlusion (MCAO), which showed ischemic injuries (increase in neurological deficit score and infarct volume) and upregulation of Mul1 in brain tissues. Next, Mul1 siRNAs were injected intracerebroventricularly to knockdown Mul1 expression, which evidently attenuated brain injuries (decrease in neurological deficit score, infarct volume and caspase-3 activity), restored mitochondrial dynamics and functions (decreases in mitochondrial fission and cytochrome c release while increase in ATP production), and restored protein levels of dynamin-related protein 1 (Drp1, a mitochondrial fission protein) and mitofusin2 (Mfn2, a mitochondrial fusion protein) through suppressing their sumoylation and ubiquitination, respectively. Finally, PC12â¯cells were cultured under hypoxic condition to mimic the ischemic stroke. Consistently, knockdown of Mul1 significantly reduced hypoxic injuries (decrease in apoptosis and LDH release), restored protein levels of Drp1 and Mfn2, recovered mitochondrial dynamics and functions (decreases in mitochondrial fission, mitochondrial membrane potential, reactive oxygen species production and cytochrome c release while increase in ATP production). Based on these observations, we conclude that upregulation of Mul1 contributes to brain injury in ischemic stroke rats and disturbs mitochondrial dynamics through sumoylation of Drp1 and ubiquitination of Mfn2.
Assuntos
Isquemia Encefálica/complicações , Encéfalo/patologia , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Apoptose , Hipóxia Celular , Modelos Animais de Doenças , Dinaminas/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Técnicas de Silenciamento de Genes , Masculino , Proteínas Mitocondriais/deficiência , Proteínas Mitocondriais/genética , Células PC12 , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/enzimologia , Sumoilação , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética , Regulação para CimaRESUMO
Previous studies have demonstrated that endogenous calcitonin gene-related peptide (CGRP) plays an important role in mediation of ischemic preconditioning. In the present study, we tested whether CGRP is also involved in mediation of the protective effects of postconditioning in isolated rat hearts. Sixty minutes of left coronary artery occlusion and followed by 60 min of reperfusion caused a significant decrease in cardiac function and a significant increase in creatine kinase (CK) release and infarct size. Postconditioning with three cycles of 1-min ischemia and 1-min reperfusion produced a marked improvement of cardiac function and decreased CK release and infarct size, concomitantly with an increase in the release of CGRP release in coronary effluent. However, the cardioprotection afforded by postconditioning was abolished by CGRP 8-37 (10(-7) M), a selective CGRP receptor antagonist, or pretreatment with capsaicin (50 mg/kg, s.c.), which depletes transmitters in sensory nerves. Exogenous CGRP (5 x 10(-9) M) administration of CGRP reappeared postconditioning-like cardioprotection in the rats pretreated with capsaicin. These results suggest that the protective effects of ischemic postconditioning are related to stimulation of endogenous CGRP release in rat hearts.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/uso terapêutico , Coração/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Creatina Quinase/metabolismo , Precondicionamento Isquêmico Miocárdico , Masculino , Reperfusão Miocárdica , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Ratos , Ratos Sprague-Dawley , Função Ventricular EsquerdaRESUMO
Diabetic retinopathy (DR) is a leading cause of vision loss with retinal neovascularization. This study aims to investigate whether Asymmetric dimethylarginine (ADMA) impacts the pathogenesis of DR via focusing on promoting retinal neovascularization and its underlying molecular mechanisms. Diabetic rats were induced by a single intraperitoneal injection of streptozotocin (STZ) for 20â¯weeks. ADMA levels in aqueous and the influence of hypoxia on ADMA and angiogenesis in RF/6A cells were examined. The effects and underlying molecular mechanisms of ADMA on neovascularization of RF/6A cells were further evaluated by administration of ADMA, DDAH siRNA or ephrinB2 siRNA. Results showed that ADMA levels were elevated in both aqueous from diabetic rats and culture medium in RF/6A cells pretreated with hypoxia. Administration of ADMA directly promoted proliferation, migration, adhesion and tube formation of RF/6A cells, which was further confirmed by DDAH1 siRNA or DDAH2 siRNA. In addition, ephrinB2 expression was increased under diabetic conditions, and the angiogenic effects of ADMA were blocked by ephrinB2 siRNA. In conclusion, ADMA contributes to the neovascularization of retina in diabetic mellitus, which is regulated by ephrinB2.