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Shiba M, Kato T, Seko Y, Minamino-Muta E, Tanada Y, Kimura T, Ono K. Cobalt protoporphyrin promotes heme oxygenase 1 expression and ameliorates cardiac dysfunction in long-term fasting mice. Int J Cardiol 2024; 404:131972. [PMID: 38490272 DOI: 10.1016/j.ijcard.2024.131972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/15/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
BACKGROUND The association between malnutrition and cardiac dysfunction has been reported. Heme oxygenase (HO)-1 played protective roles in the animals functioning as a myocardial infarction, heart failure, or cardiomyopathy model. We hypothesized that the administration of HO-1 inducer, cobalt protoporphyrin (CoPP) reduces oxidative stress and ameliorates cardiac systolic dysfunction in long-term fasting mice. METHODS C57BL/6 J mice were classified into three groups: fed mice (fed group), 48-h fasting mice with a single intraperitoneal injection of the corresponding vehicle (fasting group), and 48-h fasting mice with a single intraperitoneal injection of 5 mg/kg CoPP (CoPP group). RESULTS The fasting group showed a significant increase in heme and 4-hydroxy-2-nonenal (4HNE) protein in the heart tissue, and reduced left ventricular ejection fraction (LVEF) when compared with the fed group. The CoPP group showed significantly increased protein levels of nuclear factor-erythroid 2-related factor 2 and HO-1, and increased mRNA expression levels of HO-1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, forkhead box protein O1, sirtuin-1, cyclooxygenase 2, and superoxide dismutase 2, and reduced levels of heme and 4HNE protein when compared with the fasting group. LVEF were significantly higher in the CoPP group than in the fasting group. CONCLUSIONS Administration of CoPP reduced heme accumulation and oxidative stress, and ameliorated cardiac systolic dysfunction in long-term fasting mice. This study suggests that heme accumulation may be associated with impaired cardiac function induced by long-term fasting and that HO-1 may be a key factor or therapeutic target.
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Affiliation(s)
- Masayuki Shiba
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takao Kato
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Yuta Seko
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Eri Minamino-Muta
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yohei Tanada
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Koh Ono
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Mota GAF, de Souza SLB, Vileigas DF, da Silva VL, Sant'Ana PG, Costa LCDS, Padovani CR, Zanatti Bazan SG, Buzalaf MAR, Santos LDD, Okoshi MP, Gatto M, Cicogna AC. Myocardial proteome changes in aortic stenosis rats subjected to long-term aerobic exercise. J Cell Physiol 2024; 239:e31199. [PMID: 38291668 DOI: 10.1002/jcp.31199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 02/01/2024]
Abstract
The effects of exercise training (ET) on the heart of aortic stenosis (AS) rats are controversial and the mechanisms involved in alterations induced by ET have been poorly clarified. In this study, we analyzed the myocardial proteome to identify proteins modulated by moderate-intensity aerobic ET in rats with chronic supravalvular AS. Wistar rats were divided into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary aortic stenosis (AS-Sed), and exercised AS (AS-Ex). ET consisted of five treadmill running sessions per week for 16 weeks. Statistical analysis was performed by ANOVA or Kruskal-Wallis and Goodman tests. Results were discussed at a significance level of 5%. At the end of the experiment, AS-Ex rats had higher functional capacity, lower blood lactate concentration, and better cardiac structural and left ventricular (LV) functional parameters than the AS-Sed. Myocardial proteome analysis showed that AS-Sed had higher relative protein abundance related to the glycolytic pathway, oxidative stress, and inflammation, and lower relative protein abundance related to beta-oxidation than C-Sed. AS-Ex had higher abundance of one protein related to mitochondrial biogenesis and lower relative protein abundance associated with oxidative stress and inflammation than AS-Sed. Proteomic data were validated for proteins related to lipid and glycolytic metabolism. Chronic pressure overload changes the abundance of myocardial proteins that are mainly involved in lipid and glycolytic energy metabolism in rats. Moderate-intensity aerobic training attenuates changes in proteins related to oxidative stress and inflammation and increases the COX4I1 protein, related to mitochondrial biogenesis. Protein changes are combined with improved functional capacity, cardiac remodeling, and LV function in AS rats.
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Affiliation(s)
- Gustavo Augusto Ferreira Mota
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | - Sérgio Luiz Borges de Souza
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | | | - Vitor Loureiro da Silva
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | - Paula Grippa Sant'Ana
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | - Licia Carla da Silva Costa
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil
| | - Carlos Roberto Padovani
- Department of Biostatistics, Institute of Bioscience, São Paulo State University, Botucatu, São Paulo, Brazil
| | - Silméia Garcia Zanatti Bazan
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | | | | | - Marina Politi Okoshi
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | - Mariana Gatto
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
| | - Antonio Carlos Cicogna
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University, UNESP, São Paulo, São Paulo, Brazil
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Wang Z, Gao J, Teng H, Peng J. Effects of Doxorubicin on Heme Biosynthesis and Metabolism in Cardiomyocyte. Arq Bras Cardiol 2021; 116:315-322. [PMID: 33656082 PMCID: PMC7909973 DOI: 10.36660/abc.20190437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 12/27/2019] [Indexed: 11/23/2022] Open
Abstract
Fundamento A doxorrubicina está associada à cardiotoxicidade e à morbidade cardíaca tardia. O heme está relacionado ao stress oxidativo celular. Entretanto, sua regulação específica em cardiomiócitos sob os efeitos de doxorrubicina ainda não foi documentada. Objetivo Nosso objetivo é avaliar as alterações de enzimas limitantes de velocidade no caminho metabólico do heme sob o efeito de doxorrubicina. Métodos Cardiomiócitos H9c2 com doxorrubicina em concentrações diferentes (1, 2, 5, 10μM respectivamente). Os testes de PCR em tempo real e Western Blot foram usados para determinar a expressão de proteína e mRNA para quatro enzimas cruciais (ALAS1, ALAS2, HOX-1, e HOX-2) que regulam o metabolismo do heme celular, e os níveis de heme foram detectados por ELISA. Um p<0,01 foi considerado significativo. Resultados Observamos um padrão com alteração dependendo da dose nos níveis de heme nas células H9c2 com o nível mais alto na concentração de 5μM de doxorrubicina, o que ocorreu sincronicamente com o nível mais alto de regulação para cima de ALAS1, bem como as enzimas degenerativas HOX-1 e HOX-2 na expressão de proteína e mRNA. Em contraste, observamos que a ALAS2 foi regulada para baixo gradualmente, inversamente proporcional às concentrações de doxorrubicina. Conclusão O aumento da expressão de ALAS1 pode ter um papel na elevação do nível do heme quando o cardiomiócito H9c2 for exposto à doxorrubicina, e pode ser um alvo terapêutico para a toxicidade miocárdica induzida por doxorrubicina. (Arq Bras Cardiol. 2021; 116(2):315-322)
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Affiliation(s)
- Zuoyan Wang
- Capital Medical University Affiliated Beijing Shijitan Hospital,Beijing - China
| | - Junyi Gao
- Capital Medical University Affiliated Beijing Shijitan Hospital,Beijing - China
| | - Haobo Teng
- Capital Medical University Affiliated Beijing Shijitan Hospital,Beijing - China
| | - Jianjun Peng
- Capital Medical University Affiliated Beijing Shijitan Hospital,Beijing - China
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4
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Gatto M, Mota GAF. Influence of Doxorubicin Treatment on Heme Metabolism in Cardiomyoblasts: An In Vitro Study. Arq Bras Cardiol 2021; 116:323-324. [PMID: 33656083 PMCID: PMC7909966 DOI: 10.36660/abc.20200662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Mariana Gatto
- Departamento de Clínica MédicaFaculdade de Medicina de BotucatuUniversidade Estadual PaulistaBotucatuSPBrasilDepartamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista - Unesp, Botucatu, SP - Brasil
| | - Gustavo Augusto Ferreira Mota
- Departamento de Clínica MédicaFaculdade de Medicina de BotucatuUniversidade Estadual PaulistaBotucatuSPBrasilDepartamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista - Unesp, Botucatu, SP - Brasil
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5
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Alvarado G, Jeney V, Tóth A, Csősz É, Kalló G, Huynh AT, Hajnal C, Kalász J, Pásztor ET, Édes I, Gram M, Akerström B, Smith A, Eaton JW, Balla G, Papp Z, Balla J. Heme-induced contractile dysfunction in human cardiomyocytes caused by oxidant damage to thick filament proteins. Free Radic Biol Med 2015; 89:248-62. [PMID: 26409224 DOI: 10.1016/j.freeradbiomed.2015.07.158] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 10/23/2022]
Abstract
Intracellular free heme predisposes to oxidant-mediated tissue damage. We hypothesized that free heme causes alterations in myocardial contractility via disturbed structure and/or regulation of the contractile proteins. Isometric force production and its Ca(2+)-sensitivity (pCa50) were monitored in permeabilized human ventricular cardiomyocytes. Heme exposure altered cardiomyocyte morphology and evoked robust decreases in Ca(2+)-activated maximal active force (Fo) while increasing Ca(2+)-independent passive force (F passive). Heme treatments, either alone or in combination with H2O2, did not affect pCa50. The increase in F passive started at 3 µM heme exposure and could be partially reversed by the antioxidant dithiothreitol. Protein sulfhydryl (SH) groups of thick myofilament content decreased and sulfenic acid formation increased after treatment with heme. Partial restoration in the SH group content was observed in a protein running at 140 kDa after treatment with dithiothreitol, but not in other proteins, such as filamin C, myosin heavy chain, cardiac myosin binding protein C, and α-actinin. Importantly, binding of heme to hemopexin or alpha-1-microglobulin prevented its effects on cardiomyocyte contractility, suggesting an allosteric effect. In line with this, free heme directly bound to myosin light chain 1 in human cardiomyocytes. Our observations suggest that free heme modifies cardiac contractile proteins via posttranslational protein modifications and via binding to myosin light chain 1, leading to severe contractile dysfunction. This may contribute to systolic and diastolic cardiac dysfunctions in hemolytic diseases, heart failure, and myocardial ischemia-reperfusion injury.
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Affiliation(s)
- Gerardo Alvarado
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; Department of Nephrology, Institute of Internal Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Viktória Jeney
- Department of Nephrology, Institute of Internal Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; MTA-DE Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences, H-4032 Debrecen, Hungary
| | - Attila Tóth
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Éva Csősz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Gergő Kalló
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - An T Huynh
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Csaba Hajnal
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Judit Kalász
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Enikő T Pásztor
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - István Édes
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Magnus Gram
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Bo Akerström
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Ann Smith
- School of Biological Sciences, University of Missouri-Kansas City, MO, USA
| | - John W Eaton
- Molecular Targets Program, James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40059, USA
| | - György Balla
- MTA-DE Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences, H-4032 Debrecen, Hungary; Institute of Pediatrics, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Zoltán Papp
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - József Balla
- Department of Nephrology, Institute of Internal Medicine, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; MTA-DE Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences, H-4032 Debrecen, Hungary.
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6
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Affiliation(s)
- Konrad Teodor Sawicki
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL (K.T.S., H.C.C., H.A.)
| | - Hsiang-Chun Chang
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL (K.T.S., H.C.C., H.A.)
| | - Hossein Ardehali
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL (K.T.S., H.C.C., H.A.)
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7
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Gemelli C, Dongmo BM, Ferrarini F, Grande A, Corsi L. Cytotoxic effect of hemin in colonic epithelial cell line: involvement of 18 kDa translocator protein (TSPO). Life Sci 2014; 107:14-20. [PMID: 24792517 DOI: 10.1016/j.lfs.2014.04.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/14/2014] [Accepted: 04/21/2014] [Indexed: 11/29/2022]
Abstract
AIMS The aim of this study is to investigate the effect of hemin in colonic epithelial cells (Caco-2) cell proliferation and if this effect was due to a direct modulation of 18-kDa translocator protein (TSPO) and/or heme oxygenase type 1 (HO-1). MAIN METHODS The main methods are as follow: cell proliferation and cell cytotoxic assays on Caco-2 cell lines treated with hemin in the presence or not of 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11195) and Sn-protoporphyrin IX (Sn-PPIX), and immunoblotting for TSPO and HO-1 protein analysis, siRNA directed against TSPO. KEY FINDINGS Hemin was shown to be toxic for the Caco-2 cell line in a concentration and time dependent manner. Although hemin was able to induce HO-1 in a dose dependent manner, a specific HO-1 inhibitor, Sn-PPIX, was unable to interfere with the effect of hemin on Caco-2 cells. Instead, PK 11195, a specific TSPO ligand, was able to counteract the effect of hemin, suggesting an important role of TSPO in the hemin activity. Cell viability assay further confirms the high cytotoxic effects exerted by hemin on Caco-2 cells expressing TSPO compared to the siRNA-TSPO targeted cells. In addition, hemin was able to decrease significantly the TSPO protein density in a dose dependent manner after 24h of incubation. SIGNIFICANCE The interaction and the consecutive down regulation of TSPO by hemin played an important role in the control of Caco-2 cell viability. The presented data suggest that TSPO might contribute to protect cells from potential toxic compounds such as free tetrapyrroles, candidating this receptor as a survival receptor protein.
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Affiliation(s)
- Claudia Gemelli
- Department of Life Sciences University of Modena and Reggio Emilia, Italy
| | | | - Fabrizio Ferrarini
- Department of Life Sciences University of Modena and Reggio Emilia, Italy
| | - Alexis Grande
- Department of Life Sciences University of Modena and Reggio Emilia, Italy
| | - Lorenzo Corsi
- Department of Life Sciences University of Modena and Reggio Emilia, Italy.
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8
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Kumar S, Bandyopadhyay U. Free heme toxicity and its detoxification systems in human. Toxicol Lett 2005; 157:175-88. [PMID: 15917143 DOI: 10.1016/j.toxlet.2005.03.004] [Citation(s) in RCA: 580] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2004] [Revised: 03/11/2005] [Accepted: 03/14/2005] [Indexed: 11/16/2022]
Abstract
Severe hemolysis or myolysis occurring during pathological states, such as sickle cell disease, ischemia reperfusion, and malaria results in high levels of free heme, causing undesirable toxicity leading to organ, tissue, and cellular injury. Free heme catalyzes the oxidation, covalent cross-linking and aggregate formation of protein and its degradation to small peptides. It also catalyzes the formation of cytotoxic lipid peroxide via lipid peroxidation and damages DNA through oxidative stress. Heme being a lipophilic molecule intercalates in the membrane and impairs lipid bilayers and organelles, such as mitochondria and nuclei, and destabilizes the cytoskeleton. Heme is a potent hemolytic agent and alters the conformation of cytoskeletal protein in red cells. Free heme causes endothelial cell injury, leading to vascular inflammatory disorders and stimulates the expression of intracellular adhesion molecules. Heme acts as a pro-inflammatory molecule and heme-induced inflammation is involved in the pathology of diverse conditions; such as renal failure, arteriosclerosis, and complications after artificial blood transfusion, peritoneal endometriosis, and heart transplant failure. Heme offers severe toxic effects to kidney, liver, central nervous system and cardiac tissue. Although heme oxygenase is primarily responsible to detoxify free heme but other extra heme oxygenase systems also play a significant role to detoxify heme. A brief account of free heme toxicity and its detoxification systems along with mechanistic details are presented.
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Affiliation(s)
- Sanjay Kumar
- Division of Drug Target Discovery and Development, Central Drug Research Institute, Chatter Manzil Palace, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India
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9
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Goldstein L, Teng ZP, Zeserson E, Patel M, Regan RF. Hemin induces an iron-dependent, oxidative injury to human neuron-like cells. J Neurosci Res 2003; 73:113-21. [PMID: 12815715 DOI: 10.1002/jnr.10633] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hemin is released from hemoglobin after CNS hemorrhage and is present at high micromolar concentrations in intracranial hematomas. This highly reactive compound is potentially cytotoxic via a variety of oxidative and nonoxidative mechanisms. However, despite its clinical relevance, little is known of its effect on neuronal cells. In this study, we tested the hypotheses that hemin is toxic to human neurons at physiologically relevant concentrations and that its toxicity is iron dependent and oxidative. A homogeneous population of neuron-like cells was produced by sequential treatment of SH-SY5Y cells with retinoic acid and brain-derived neurotrophic factor, using the protocol of Encinas et al. Hemin exposure for 24 hr resulted in cell death that progressively increased between 3 and 30 microM (EC(50) approximately 10 microM); protoporphyrin IX, the iron-free congener of hemin, was not toxic. Cell death commenced at 14 hr and was preceded by a marked increase in cellular reactive oxygen species (ROS). Most injury and ROS production were prevented by concomitant treatment with an equimolar concentration of the lipid-soluble iron chelator phenanthroline; the water-soluble chelator deferoxamine was also effective at concentrations of 0.1 mM or higher. Heme oxygenase-2 was constitutively expressed by these cells, and heme oxygenase-1 was induced by hemin. Heme oxygenase inhibition attenuated ROS generation and reduced injury by about one-third. Cell death was also prevented with the sulfhydryl reducing agents glutathione and mercaptoethanol. Nuclear morphology in the hours prior to cell lysis revealed a predominantly homogenous staining pattern; the percentage of fragmented nuclei was increased only at 4 hr and then accounted for only 1.45% +/- 0.25% of cells. The general caspase inhibitor zVAD-fmk had no effect on cell viability. These results suggest that hemin is toxic to human neuron-like cells at concentrations that are less than 3% of those observed in intracranial hematomas. In this model, its toxicity is iron dependent, oxidative, and predominantly necrotic.
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Affiliation(s)
- Laurel Goldstein
- Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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10
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Regan RF, Wang Y, Ma X, Chong A, Guo Y. Activation of extracellular signal-regulated kinases potentiates hemin toxicity in astrocyte cultures. J Neurochem 2001; 79:545-55. [PMID: 11701758 DOI: 10.1046/j.1471-4159.2001.00590.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Hemin is present in intracranial hematomas in high micromolar concentrations and is a potent, lipophilic oxidant. Growing evidence suggests that heme-mediated injury may contribute to the pathogenesis of CNS hemorrhage. Extracellular signal-regulated kinases (ERKs) are activated by oxidants in some cell types, and may alter cellular vulnerability to oxidative stress. In this study, the effect of hemin on ERK activation was investigated in cultured murine cortical astrocytes, and the consequence of this activation on cell viability was quantified. Hemin was rapidly taken up by astrocytes, and generated reactive oxygen species (ROS) within 30 min. Increased immunoreactivity of dually phosphorylated ERK1/2 was observed in hemin-treated cultures at 30-120 min, without change in total ERK. Surprisingly, ERK activation was not attenuated by concomitant treatment with antioxidants (U74500A or 1,10-phenanthroline) at concentrations that blocked ROS generation. Cell death commenced after 2 h of hemin exposure and was reduced by antioxidants and by the caspase inhibitor Z-VAD-FMK. Cytotoxicity was also attenuated by MEK inhibition with PD98059 or U0126 at concentrations that were sufficient to prevent ERK activation. Whereas the effect of Z-VAD-FMK on cell survival was transient, the effect of MEK inhibitors was long-lasting. MEK inhibitors had no effect on cellular hemin uptake or subsequent ROS generation. The present results suggest that hemin activates ERK in astrocytes via a mechanism that is independent of ROS generation. This activation sensitizes astrocytes to hemin-mediated oxidative injury.
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Affiliation(s)
- R F Regan
- Division of Emergency Medicine, Department of Surgery, Thomas Jefferson University, Philadelphia 19107, USA.
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11
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Limaye DA, Shaikh ZA. Cytotoxicity of cadmium and characteristics of its transport in cardiomyocytes. Toxicol Appl Pharmacol 1999; 154:59-66. [PMID: 9882592 DOI: 10.1006/taap.1998.8575] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cadmium (Cd) is reported to produce cardiotoxicity at doses and exposure conditions that cause no effect in kidney or liver. The purpose of the present investigation was to examine the cytotoxicity of Cd to neonatal rat cardiomyocytes in primary culture and to elucidate the transport characteristics of Cd in these cells at a nontoxic concentration. Cd concentrations of 0.1 microM and higher that are well tolerated by hepatocytes and renal cortical epithelial cells were toxic to the cardiomyocyte. The plot of initial uptake rate of Cd at various concentrations was nonlinear suggesting that, in addition to simple diffusion, other processes may also be involved. These processes required metabolic energy as pretreatment with dinitrophenol or sodium fluoride inhibited 58 and 59% of the Cd uptake, respectively. The uptake of Cd was also affected by the incubation temperature and lowering the temperature from 37 to 4 degreesC reduced Cd uptake over 30 min by 61%. Cd uptake required interaction with membrane sulfhydryl groups; pretreatment with p-chloromercuribenzenesulfonic acid or mercuric chloride reduced Cd uptake by 46 and 58%, respectively. Cd utilized the transport pathways for calcium (Ca), zinc (Zn), and copper (Cu). Coincubation with 1.26 mM Ca competitively inhibited Cd uptake by 77%. In the presence of Ca, 30 microM Zn or Cu further inhibited Cd accumulation competitively by as much as 63 and 32%, respectively. Cd could enter the cardiomyocytes through Ca channels and Ca channel blocker, verapamil, inhibited up to 76% of Cd uptake. From the above results it can be concluded that Cd is highly toxic to the cardiomyocytes. A majority of Cd enters these cells through transport processes that exist for Ca, Zn, and Cu. The transport processes utilized by Cd are temperature sensitive and dependent on metabolic energy. Furthermore, these involve membrane sulfhydryl groups and include Ca channels.
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Affiliation(s)
- D A Limaye
- College of Pharmacy, University of Rhode Island, Kingston, Rhode Island, 02881, USA
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