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Niiuchi A, Tojo T, Kondo T, Yuasa M. Permeation behavior of porphyrin derivatives with different functional group positions across cancer cell membranes. Bioorg Med Chem Lett 2023; 94:129463. [PMID: 37647999 DOI: 10.1016/j.bmcl.2023.129463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023]
Abstract
Porphyrin, which shows selective accumulation in cancer cells, has attracted attention as a drug carrier. The influences of the functional porphyrin positions (β- and meso-positions) on porphyrin accumulation must be understood. In this work, we focused on the investigation of the phenyl functional group whose β-position influences cancer cell accumulation through direct membrane permeation and endocytosis. The endocytic pathway, in particular, is influenced by both clathrin-dependent and caveolae-dependent endocytosis.
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Affiliation(s)
- Ayano Niiuchi
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Toshifumi Tojo
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
| | - Takeshi Kondo
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan; Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Makoto Yuasa
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan; Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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2
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Pires IS, Berthiaume F, Palmer AF. Engineering Therapeutics to Detoxify Hemoglobin, Heme, and Iron. Annu Rev Biomed Eng 2023; 25:1-21. [PMID: 37289555 DOI: 10.1146/annurev-bioeng-081622-031203] [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] [Indexed: 06/10/2023]
Abstract
Hemolysis (i.e., red blood cell lysis) can increase circulatory levels of cell-free hemoglobin (Hb) and its degradation by-products, namely heme (h) and iron (Fe). Under homeostasis, minor increases in these three hemolytic by-products (Hb/h/Fe) are rapidly scavenged and cleared by natural plasma proteins. Under certain pathophysiological conditions, scavenging systems become overwhelmed, leading to the accumulation of Hb/h/Fe in the circulation. Unfortunately, these species cause various side effects such as vasoconstriction, hypertension, and oxidative organ damage. Therefore, various therapeutics strategies are in development, ranging from supplementation with depleted plasma scavenger proteins to engineered biomimetic protein constructs capable of scavenging multiple hemolytic species. In this review, we briefly describe hemolysis and the characteristics of the major plasma-derived protein scavengers of Hb/h/Fe. Finally, we present novel engineering approaches designed to address the toxicity of these hemolytic by-products.
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Affiliation(s)
- Ivan S Pires
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA;
| | - François Berthiaume
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
| | - Andre F Palmer
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA;
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3
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A Model Peptide Reveals Insights into the Interaction of Human Hemopexin with Heme. Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10441-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractUnder hemolytic conditions, toxic heme is scavenged by hemopexin. Recently, the heme-binding properties of hemopexin have been reassessed, which revealed a KD of ~ 0.32 nM as well as a stoichiometry of one to two heme molecules binding to hemopexin. A 66mer hemopexin-derived peptide that spans over three heme-binding motifs was used to verify the earlier suggested heme-recruiting mechanism. Herein, we employed spectroscopic and computational methods to substantiate the hypothesis of more than one heme molecule binding to hemopexin and to analyze the heme-binding mode. Both, hemopexin and the 66mer peptide, were found to bind heme in mixed penta- and hexacoordinated states, which strongly indicates that heme binding follows distinct criteria and increases rigidity of the peptide-heme complex. Additional in silico molecular dynamics simulations support these experimental findings and, thus, contribute to our understanding of the molecular basis of the heme-hemopexin interaction. This analysis provides further details for consideration of hemopexin in biomedical applications.
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4
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Menon AV, Liu J, Tsai HP, Zeng L, Yang S, Asnani A, Kim J. Excess heme upregulates heme oxygenase 1 and promotes cardiac ferroptosis in mice with sickle cell disease. Blood 2022; 139:936-941. [PMID: 34388243 PMCID: PMC8832481 DOI: 10.1182/blood.2020008455] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/08/2021] [Indexed: 11/20/2022] Open
Abstract
Sickle cell disease (SCD) is characterized by increased hemolysis, which results in plasma heme overload and ultimately cardiovascular complications. Here, we hypothesized that increased heme in SCD causes upregulation of heme oxygenase 1 (Hmox1), which consequently drives cardiomyopathy through ferroptosis, an iron-dependent non-apoptotic form of cell death. First, we demonstrated that the Townes SCD mice had higher levels of hemopexin-free heme in the serum and increased cardiomyopathy, which was corrected by hemopexin supplementation. Cardiomyopathy in SCD mice was associated with upregulation of cardiac Hmox1, and inhibition or induction of Hmox1 improved or worsened cardiac damage, respectively. Because free iron, a product of heme degradation through Hmox1, has been implicated in toxicities including ferroptosis, we evaluated the downstream effects of elevated heme in SCD. Consistent with Hmox1 upregulation and iron overload, levels of lipid peroxidation and ferroptotic markers increased in SCD mice, which were corrected by hemopexin administration. Moreover, ferroptosis inhibitors decreased cardiomyopathy, whereas a ferroptosis inducer erastin exacerbated cardiac damage in SCD and induced cardiac ferroptosis in nonsickling mice. Finally, inhibition or induction of Hmox1 decreased or increased cardiac ferroptosis in SCD mice, respectively. Together, our results identify ferroptosis as a key mechanism of cardiomyopathy in SCD.
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Affiliation(s)
| | - Jing Liu
- Division of Cardiology, Beth Israel Deaconess Medical Center, Boston, MA; and
| | | | - Lingxue Zeng
- Department of Biomedical & Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA
| | - Seungjeong Yang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA
| | - Aarti Asnani
- Division of Cardiology, Beth Israel Deaconess Medical Center, Boston, MA; and
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA
- Department of Biomedical & Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA
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5
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Vallecorsa P, Di Venosa G, Ballatore MB, Ferreyra D, Mamone L, Sáenz D, Calvo G, Durantini E, Casas A. Novel meso-substituted porphyrin derivatives and its potential use in photodynamic therapy of cancer. BMC Cancer 2021; 21:547. [PMID: 33985453 PMCID: PMC8117271 DOI: 10.1186/s12885-021-08286-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/04/2021] [Indexed: 11/10/2022] Open
Abstract
Background Photodynamic therapy (PDT) is an anticancer treatment that utilizes the interaction of light and a photosensitiser (PS), promoting tumour cell death mediated by generation of reactive oxygen species. In this study, we evaluated the in vitro photoactivity of four meso-substituted porphyrins and a porphyrin coupled to a fullerene. Methods The cell line employed was the LM3 mammary adenocarcinoma, and the PS with the best photokilling activity was administered to mice bearing the LM3 subcutaneously implanted adenocarcinoma. The TEMCP4+ porphyrin and its analogue TEMCC4+ chlorine contain four identical carbazoyl substituents at the meso positions of the tetrapyrrolic macrocycle and have A4 symmetry. The TAPP derivative also has A4 symmetry, and it is substituted at the meso positions by aminopropoxy groups. The DAPP molecule has ABAB symmetry with aminopropoxy and the trifluoromethyl substituents in trans positions. The TCP-C604+ dyad is formed by a porphyrin unit covalently attached to the fullerene C60. Results The PSs are taken up by the cells with the following efficiency: TAPP> TEMCP4+ = TEMCC4+ > DAPP >TCP-C604+, and the amount of intracellular PS correlates fairly with the photodamage degree, but also the quantum yields of singlet oxygen influence the PDT outcome. TAPP, DAPP, TEMCC4+ and TEMCP4+ exhibit high photoactivity against LM3 mammary carcinoma cells, being TAPP the most active. After topical application of TAPP on the skin of mice bearing LM3 tumours, the molecule is localized mainly in the stratum corneum, and at a lower extent in hair follicles and sebaceous glands. Systemic administration of TAPP produces a tumour: normal skin ratio of 31.4, and high accumulation in intestine and lung. Conclusion The results suggest a potential use of topical TAPP for the treatment of actinic keratosis and skin adnexal neoplasms. In addition, selectivity for tumour tissue after systemic administration highlights the selectivity of and potentiality of TAPP as a new PS. Supplementary Information The online version contains supplementary material available at 10.1186/s12885-021-08286-6.
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Affiliation(s)
- Pablo Vallecorsa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina
| | - Gabriela Di Venosa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina
| | - M Belén Ballatore
- IDAS-CONICET, Departamento de Química, FCEFQYN, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Dario Ferreyra
- IDAS-CONICET, Departamento de Química, FCEFQYN, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Leandro Mamone
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina
| | - Daniel Sáenz
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina
| | - Gustavo Calvo
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina
| | - Edgardo Durantini
- IDAS-CONICET, Departamento de Química, FCEFQYN, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Adriana Casas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas Gral. José de San Martín, Universidad de Buenos Aires, Córdoba 2351 1er subsuelo, CP1120AAF, Ciudad de Buenos Aires, Argentina.
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6
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Vinchi F, Sparla R, Passos ST, Sharma R, Vance SZ, Zreid HS, Juaidi H, Manwani D, Yazdanbakhsh K, Nandi V, Silva AMN, Agarvas AR, Fibach E, Belcher JD, Vercellotti GM, Ghoti H, Muckenthaler MU. Vasculo-toxic and pro-inflammatory action of unbound haemoglobin, haem and iron in transfusion-dependent patients with haemolytic anaemias. Br J Haematol 2021; 193:637-658. [PMID: 33723861 PMCID: PMC8252605 DOI: 10.1111/bjh.17361] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
Increasing evidence suggests that free haem and iron exert vasculo‐toxic and pro‐inflammatory effects by activating endothelial and immune cells. In the present retrospective study, we compared serum samples from transfusion‐dependent patients with β‐thalassaemia major and intermedia, hereditary spherocytosis and sickle cell disease (SCD). Haemolysis, transfusions and ineffective erythropoiesis contribute to haem and iron overload in haemolytic patients. In all cohorts we observed increased systemic haem and iron levels associated with scavenger depletion and toxic ‘free’ species formation. Endothelial dysfunction, oxidative stress and inflammation markers were significantly increased compared to healthy donors. In multivariable logistic regression analysis, oxidative stress markers remained significantly associated with both haem‐ and iron‐related parameters, while soluble vascular cell adhesion molecule 1 (sVCAM‐1), soluble endothelial selectin (sE‐selectin) and tumour necrosis factor α (TNFα) showed the strongest association with haem‐related parameters and soluble intercellular adhesion molecule 1 (sICAM‐1), sVCAM‐1, interleukin 6 (IL‐6) and vascular endothelial growth factor (VEGF) with iron‐related parameters. While hereditary spherocytosis was associated with the highest IL‐6 and TNFα levels, β‐thalassaemia major showed limited inflammation compared to SCD. The sVCAM1 increase was significantly lower in patients with SCD receiving exchange compared to simple transfusions. The present results support the involvement of free haem/iron species in the pathogenesis of vascular dysfunction and sterile inflammation in haemolytic diseases, irrespective of the underlying haemolytic mechanism, and highlight the potential therapeutic benefit of iron/haem scavenging therapies in these conditions.
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Affiliation(s)
- Francesca Vinchi
- Iron Research Program, New York Blood Center, New York, NY, USA.,Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA.,Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Heidelberg University, Heidelberg, Germany
| | - Richard Sparla
- Center for Translational Biomedical Iron Research, Department of Pediatric Oncology, Hematology, Immunology and Pulmonology, University of Heidelberg, Heidelberg, Germany
| | - Sara T Passos
- Iron Research Program, New York Blood Center, New York, NY, USA
| | - Richa Sharma
- Iron Research Program, New York Blood Center, New York, NY, USA
| | - S Zebulon Vance
- Iron Research Program, New York Blood Center, New York, NY, USA
| | - Hala S Zreid
- Department of Internal Medicine, Al Shifa Hospital, Gaza, Palestine
| | - Hesham Juaidi
- Department of Internal Medicine, Al Shifa Hospital, Gaza, Palestine
| | - Deepa Manwani
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA.,Pediatric Hematology, The Children's Hospital at Montefiore, New York, NY, USA
| | | | - Vijay Nandi
- Laboratory of Data Analytic Services, New York Blood Center, New York, NY, USA
| | - André M N Silva
- REQUIMTE-LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, University of Porto, Porto, Portugal
| | - Anand R Agarvas
- Center for Translational Biomedical Iron Research, Department of Pediatric Oncology, Hematology, Immunology and Pulmonology, University of Heidelberg, Heidelberg, Germany
| | - Eitan Fibach
- Department of Hematology, The Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - John D Belcher
- Department of Medicine, Division of Hematology, Oncology and Transplantation, Vascular Biology Center, University of Minnesota, Minneapolis, MN, USA
| | - Gregory M Vercellotti
- Department of Medicine, Division of Hematology, Oncology and Transplantation, Vascular Biology Center, University of Minnesota, Minneapolis, MN, USA
| | - Husam Ghoti
- European Center for Cancer and Cell Therapy (ECCT), Nicosia, Cyprus
| | - Martina U Muckenthaler
- Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Heidelberg University, Heidelberg, Germany.,Center for Translational Biomedical Iron Research, Department of Pediatric Oncology, Hematology, Immunology and Pulmonology, University of Heidelberg, Heidelberg, Germany.,German Center for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Heidelberg, Germany.,Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany
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7
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Detzel MS, Schmalohr BF, Steinbock F, Hopp MT, Ramoji A, Paul George AA, Neugebauer U, Imhof D. Revisiting the interaction of heme with hemopexin. Biol Chem 2021; 402:675-691. [PMID: 33581700 DOI: 10.1515/hsz-2020-0347] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/06/2021] [Indexed: 12/23/2022]
Abstract
In hemolytic disorders, erythrocyte lysis results in massive release of hemoglobin and, subsequently, toxic heme. Hemopexin is the major protective factor against heme toxicity in human blood and currently considered for therapeutic use. It has been widely accepted that hemopexin binds heme with extraordinarily high affinity of <1 pM in a 1:1 ratio. However, several lines of evidence point to a higher stoichiometry and lower affinity than determined 50 years ago. Here, we re-analyzed these data. SPR and UV/Vis spectroscopy were used to monitor the interaction of heme with the human protein. The heme-binding sites of hemopexin were characterized using hemopexin-derived peptide models and competitive displacement assays. We obtained a K D value of 0.32 ± 0.04 nM and the ratio for the interaction was determined to be 1:1 at low heme concentrations and at least 2:1 (heme:hemopexin) at high concentrations. We were able to identify two yet unknown potential heme-binding sites on hemopexin. Furthermore, molecular modelling with a newly created homology model of human hemopexin suggested a possible recruiting mechanism by which heme could consecutively bind several histidine residues on its way into the binding pocket. Our findings have direct implications for the potential administration of hemopexin in hemolytic disorders.
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Affiliation(s)
- Milena Sophie Detzel
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Benjamin Franz Schmalohr
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Francèl Steinbock
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Marie-Thérèse Hopp
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Anuradha Ramoji
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, D-07747Jena, Germany.,Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, D-07745Jena, Germany
| | - Ajay Abisheck Paul George
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
| | - Ute Neugebauer
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, D-07747Jena, Germany.,Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, D-07745Jena, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, An der Immenburg 4, D-53121Bonn, Germany
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8
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Karnaukhova E, Owczarek C, Schmidt P, Schaer DJ, Buehler PW. Human Plasma and Recombinant Hemopexins: Heme Binding Revisited. Int J Mol Sci 2021; 22:ijms22031199. [PMID: 33530421 PMCID: PMC7866118 DOI: 10.3390/ijms22031199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/24/2020] [Indexed: 11/24/2022] Open
Abstract
Plasma hemopexin (HPX) is the key antioxidant protein of the endogenous clearance pathway that limits the deleterious effects of heme released from hemoglobin and myoglobin (the term “heme” is used in this article to denote both the ferrous and ferric forms). During intra-vascular hemolysis, heme partitioning to protein and lipid increases as the plasma concentration of HPX declines. Therefore, the development of HPX as a replacement therapy during high heme stress could be a relevant intervention for hemolytic disorders. A logical approach to enhance HPX yield involves recombinant production strategies from human cell lines. The present study focuses on a biophysical assessment of heme binding to recombinant human HPX (rhHPX) produced in the Expi293FTM (HEK293) cell system. In this report, we examine rhHPX in comparison with plasma HPX using a systematic analysis of protein structural and functional characteristics related to heme binding. Analysis of rhHPX by UV/Vis absorption spectroscopy, circular dichroism (CD), size-exclusion chromatography (SEC)-HPLC, and catalase-like activity demonstrated a similarity to HPX fractionated from plasma. In particular, the titration of HPX apo-protein(s) with heme was performed for the first time using a wide range of heme concentrations to model HPX–heme interactions to approximate physiological conditions (from extremely low to more than two-fold heme molar excess over the protein). The CD titration data showed an induced bisignate CD Soret band pattern typical for plasma and rhHPX versions at low heme-to-protein molar ratios and demonstrated that further titration is dependent on the amount of protein-bound heme to the extent that the arising opposite CD couplet results in a complete inversion of the observed CD pattern. The data generated in this study suggest more than one binding site in both plasma and rhHPX. Furthermore, our study provides a useful analytical platform for the detailed characterization of HPX–heme interactions and potentially novel HPX fusion constructs.
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Affiliation(s)
- Elena Karnaukhova
- Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
- Correspondence: (E.K.); (P.W.B.)
| | - Catherine Owczarek
- CSL Limited, Bio21 Institute, Parkville, Victoria 3010, Australia; (C.O.); (P.S.)
| | - Peter Schmidt
- CSL Limited, Bio21 Institute, Parkville, Victoria 3010, Australia; (C.O.); (P.S.)
| | - Dominik J. Schaer
- Division of Internal Medicine, University Hospital of Zurich, 8091 Zurich, Switzerland;
| | - Paul W. Buehler
- Department of Pathology, The University of Maryland School of Medicine, Baltimore, MD 21201, USA
- The Center for Blood Oxygen Transport and Hemostasis, Department of Pediatrics, The University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Correspondence: (E.K.); (P.W.B.)
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9
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Mugas ML, Calvo G, Marioni J, Céspedes M, Martinez F, Sáenz D, Di Venosa G, Cabrera JL, Montoya SN, Casas A. Photodynamic therapy of tumour cells mediated by the natural anthraquinone parietin and blue light. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 214:112089. [PMID: 33271387 DOI: 10.1016/j.jphotobiol.2020.112089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/15/2020] [Accepted: 11/18/2020] [Indexed: 12/21/2022]
Abstract
Photodynamic therapy (PDT) is a treatment for superficial tumours involving the administration of a photosensitiser followed by irradiation. The potential of the natural anthraquinone parietin (PTN) in PDT is still relatively unexploited. In the present work, PTN isolated from the lichen Teoloschistes nodulifer (Nyl.) Hillman (Telochistaceae) was evaluated as a potential photosensitiser on tumour cells employing UVA-Vis and blue light. Blue light of 2 J/cm2 induced 50% death of K562 leukaemic cells treated 1 h with 30 μM PTN (Protocol a). Higher light doses (8 J/cm2) were needed to achieve the same percentage of cell death employing lower PTN concentrations (3 μM) and higher exposure times (24 h) (Protocol b). Cell cycle analysis after both protocols of PTN-PDT revealed a high percentage of sub-G1 cells. PTN was found to be taken up by K562 cells mainly by passive diffusion. Other tumour cells such as ovary cancer IGROV-1 and LM2 mammary carcinoma, as well as the normal keratinocytes HaCaT, were also photosensitised with PTN-PDT. We conclude that PTN is a promising photosensitiser for PDT of superficial malignancies and purging of leukaemic cells, when illuminated with blue light. Thus, this light wavelength is proposed to replace the Vis-UVA lamps generally employed for the photosensitisation of anthraquinones.
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Affiliation(s)
- María Laura Mugas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina; Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas. Córdoba, Argentina
| | - Gustavo Calvo
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina
| | - Juliana Marioni
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas. Córdoba, Argentina
| | - Mariela Céspedes
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina
| | - Florencia Martinez
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal (IMBIV). Córdoba, Argentina
| | - Daniel Sáenz
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina
| | - Gabriela Di Venosa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina
| | - José L Cabrera
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas. Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal (IMBIV). Córdoba, Argentina
| | - Susana Núñez Montoya
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas. Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto Multidisciplinario de Biología Vegetal (IMBIV). Córdoba, Argentina
| | - Adriana Casas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, Universidad de Buenos Aires. Ciudad de Buenos Aires, Argentina.
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10
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Mehta NU, Grijalva V, Hama S, Wagner A, Navab M, Fogelman AM, Reddy ST. Apolipoprotein E-/- Mice Lacking Hemopexin Develop Increased Atherosclerosis via Mechanisms That Include Oxidative Stress and Altered Macrophage Function. Arterioscler Thromb Vasc Biol 2016; 36:1152-63. [PMID: 27079878 DOI: 10.1161/atvbaha.115.306991] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 03/31/2016] [Indexed: 12/22/2022]
Abstract
OBJECTIVE We previously reported that hemopexin (Hx), a heme scavenger, is significantly increased and associated with proinflammatory high-density lipoprotein under atherogenic conditions. Although it is established that Hx together with macrophages plays a role in mitigating oxidative damage, the role of Hx in the development of atherosclerosis is unknown. APPROACH AND RESULTS We used Hx and apoE double-knockout mice (HxE(-/-)) to determine the role of Hx in the development of atherosclerosis. HxE(-/-) mice had significantly more free heme, reactive oxygen species, and proinflammatory high-density lipoprotein in their circulation, when compared with control apoE(-/-) mice. Atherosclerotic plaque area (apoE(-/-)=9.72±2.5×10(4) μm(2) and HxE(-/-)=27.23±3.6×10(4) μm(2)) and macrophage infiltration (apoE(-/-)=38.8±5.8×10(3) μm(2) and HxE(-/-)=103.4±17.8×10(3) μm(2)) in the aortic sinus were significantly higher in the HxE(-/-) mice. Atherosclerotic lesions in the aortas were significantly higher in the HxE(-/-) mice compared with apoE(-/-) mice. Analysis of polarization revealed that macrophages from HxE(-/-) mice were more M1-like. Ex vivo studies demonstrated that HxE(-/-) macrophage cholesterol efflux capacity was significantly reduced when compared with apoE(-/-) mice. Injection of human Hx into HxE(-/-) mice reduced circulating heme levels and human Hx pretreatment of naive bone marrow cells ex vivo resulted in a shift from M1- to M2-like macrophages. CONCLUSIONS We conclude that Hx plays a novel protective role in alleviating heme-induced oxidative stress, improving inflammatory properties of high-density lipoprotein, macrophage phenotype and function, and inhibiting the development of atherosclerosis in apoE(-/-) mice.
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Affiliation(s)
- Niyati U Mehta
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Victor Grijalva
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Susan Hama
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Alan Wagner
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Mohamad Navab
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Alan M Fogelman
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.)
| | - Srinivasa T Reddy
- From the Department of Molecular and Medical Pharmacology (N.U.M., S.T.R.) and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (N.U.M., V.G., S.H., A.W., M.N., A.M.F., S.T.R.).
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11
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Huang Y, Shuai Y, Li H, Gao Z. Tyrosine residues play an important role in heme detoxification by serum albumin. Biochim Biophys Acta Gen Subj 2013; 1840:970-6. [PMID: 24252277 DOI: 10.1016/j.bbagen.2013.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 10/16/2013] [Accepted: 11/09/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND Serum albumin binds avidly to heme to form heme-serum albumin complex, also called methemalbumin, and this binding is thought to protect against the potentially toxic effects of heme. However, the mechanism of detoxification has not been fully elucidated. METHODS SDS-PAGE and Western blot were used to determine the efficiency of methemalbumin on catalyzing protein carbonylation and nitration. HPLC was used to test the formation of heme to protein cross-linked methemalbumin. RESULTS The peroxidase activity of heme increased upon human serum albumin (HSA) binding. Methemalbumin showed higher efficiency in catalyzing tyrosine oxidation than free heme in the presence of H2O2. Methemalbumin catalyzed self-nitration and significantly promoted the nitration of tyrosine in coexistent protein, but decreased the carbonylation of coexistent protein compared with heme. The heme to protein cross-linked form of methemalbumin suggested that HSA trapped the free radical accompanied by the formation of ferryl heme. When tyrosine residues in HSA were modified by iodination, HSA lost of protection effect on protein carbonylation. The low concentration of glutathione could effectively inhibit tyrosine nitration, but had no effect on protein carbonylation. CONCLUSION HSA protects against the toxic effect of heme by transferring the free radical to tyrosine residues in HSA, therefore protecting surrounding proteins from irreversible oxidation, rather than by direct inhibiting the peroxidase activity. The increased tyrosine radicals can be reduced by endogenic antioxidants such as GSH. GENERAL SIGNIFICANCE This investigation indicated the important role of tyrosine residues in heme detoxification by HSA and suggested a possible novel mechanism.
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Affiliation(s)
- Yi Huang
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China; Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Youxia Shuai
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China; Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Hailing Li
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China; Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| | - Zhonghong Gao
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China; Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
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12
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Dey S, Bindu S, Goyal M, Pal C, Alam A, Iqbal MS, Kumar R, Sarkar S, Bandyopadhyay U. Impact of intravascular hemolysis in malaria on liver dysfunction: involvement of hepatic free heme overload, NF-κB activation, and neutrophil infiltration. J Biol Chem 2012; 287:26630-46. [PMID: 22696214 DOI: 10.1074/jbc.m112.341255] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have investigated the impact of persistent intravascular hemolysis on liver dysfunction using the mouse malaria model. Intravascular hemolysis showed a positive correlation with liver damage along with the increased accumulation of free heme and reactive oxidants in liver. Hepatocytes overinduced heme oxygenase-1 (HO-1) to catabolize free heme in building up defense against this pro-oxidant milieu. However, in a condition of persistent free heme overload in malaria, the overactivity of HO-1 resulted in continuous transient generation of free iron to favor production of reactive oxidants as evident from 2',7'-dichlorofluorescein fluorescence studies. Electrophoretic mobility shift assay documented the activation of NF-κB, which in turn up-regulated intercellular adhesion molecule 1 as evident from chromatin immunoprecipitation studies. NF-κB activation also induced vascular cell adhesion molecule 1, keratinocyte chemoattractant, and macrophage inflammatory protein 2, which favored neutrophil extravasation and adhesion in liver. The infiltration of neutrophils correlated positively with the severity of hemolysis, and neutrophil depletion significantly prevented liver damage. The data further documented the elevation of serum TNFα in infected mice, and the treatment of anti-TNFα antibodies also significantly prevented neutrophil infiltration and liver injury. Deferoxamine, which chelates iron, interacts with free heme and bears antioxidant properties that prevented oxidative stress, NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Furthermore, the administration of N-acetylcysteine also prevented NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Thus, hepatic free heme accumulation, TNFα release, oxidative stress, and NF-κB activation established a link to favor neutrophil infiltration in inducing liver damage during hemolytic conditions in malaria.
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Affiliation(s)
- Sumanta Dey
- Division of Infectious Diseases and Immunology, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India
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13
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Tolosano E, Fagoonee S, Morello N, Vinchi F, Fiorito V. Heme scavenging and the other facets of hemopexin. Antioxid Redox Signal 2010; 12:305-20. [PMID: 19650691 DOI: 10.1089/ars.2009.2787] [Citation(s) in RCA: 197] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hemopexin is an acute-phase plasma glycoprotein, produced mainly by the liver and released into plasma, where it binds heme with high affinity. Other sites of hemopexin synthesis are the nervous system, skeletal muscle, retina, and kidney. The only known receptor for the heme-hemopexin complex is the scavenger receptor, LDL receptor-related protein (LRP)1, which is expressed in most cell types, thus indicating multiple sites of heme-hemopexin complex recovery. The better-characterized function of hemopexin is heme scavenging at the systemic level, consisting of the transport of heme to the liver, where it is catabolyzed or used for the synthesis of hemoproteins or exported to bile canaliculi. This is important both in physiologic heme management for heme-iron recycling and in pathologic conditions associated with intravascular hemolysis to prevent the prooxidant and proinflammatory effects of heme. Other than scavenging heme, the heme-hemopexin complex has been shown to be able to activate signaling pathways, thus promoting cell survival, and to modulate gene expression. In this review, the importance of heme scavenging by hemopexin, as well as the other emerging functions of this protein, are discussed.
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Affiliation(s)
- Emanuela Tolosano
- Molecular Biotechnology Center, University of Torino, Torino, Italy.
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14
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Smith A, Rish KR, Lovelace R, Hackney JF, Helston RM. Role for copper in the cellular and regulatory effects of heme-hemopexin. Biometals 2008; 22:421-37. [DOI: 10.1007/s10534-008-9178-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
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15
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Chua ACG, Graham RM, Trinder D, Olynyk JK. The regulation of cellular iron metabolism. Crit Rev Clin Lab Sci 2008; 44:413-59. [PMID: 17943492 DOI: 10.1080/10408360701428257] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While iron is an essential trace element required by nearly all living organisms, deficiencies or excesses can lead to pathological conditions such as iron deficiency anemia or hemochromatosis, respectively. A decade has passed since the discovery of the hemochromatosis gene, HFE, and our understanding of hereditary hemochromatosis (HH) and iron metabolism in health and a variety of diseases has progressed considerably. Although HFE-related hemochromatosis is the most widespread, other forms of HH have subsequently been identified. These forms are not attributed to mutations in the HFE gene but rather to mutations in genes involved in the transport, storage, and regulation of iron. This review is an overview of cellular iron metabolism and regulation, describing the function of key proteins involved in these processes, with particular emphasis on the liver's role in iron homeostasis, as it is the main target of iron deposition in pathological iron overload. Current knowledge on their roles in maintaining iron homeostasis and how their dysregulation leads to the pathogenesis of HH are discussed.
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Affiliation(s)
- Anita C G Chua
- School of Medicine and Pharmacology, University of Western Australia, Fremantle, Western Australia, Australia
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16
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Flaherty MM, Rish KR, Smith A, Crumbliss AL. An investigation of hemopexin redox properties by spectroelectrochemistry: biological relevance for heme uptake. Biometals 2007; 21:239-48. [PMID: 17712531 DOI: 10.1007/s10534-007-9112-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 07/26/2007] [Indexed: 10/22/2022]
Abstract
Hemopexin (HPX) has two principal roles: it sequesters free heme in vivo for the purpose of preventing the toxic effects of this moiety, which is largely due to heme's ability to catalyze free radical formation, and it transports heme intracellularly thus limiting its availability as an iron source for pathogens. Spectroelectrochemistry was used to determine the redox potential for heme and meso-heme (mH) when bound by HPX. At pH 7.2, the heme-HPX assembly exhibits E (1/2) values in the range 45-90 mV and the mH-HPX assembly in the range 5-55 mV, depending on environmental electrolyte identity. The E (1/2) value exhibits a 100 mV positive shift with a change in pH from 7.2 to 5.5 for mH-HPX, suggesting a single proton dependent equilibrium. The E (1/2) values for heme-HPX are more positive in the presence of NaCl than KCl indicating that Na(+), as well as low pH (5.5) stabilizes ferro-heme-HPX. Furthermore, comparing KCl with K(2)HPO(4), the chloride salt containing system has a lower potential, indicating that heme-HPX is easier to oxidize. These physical properties related to ferri-/ferro-heme reduction are both structurally and biologically relevant for heme release from HPX for transport and regulation of heme oxygenase expression. Consistent with this, when the acidification of endosomes is prevented by bafilomycin then heme oxygenase-1 induction by heme-HPX no longer occurs.
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Affiliation(s)
- Meghan M Flaherty
- Department of Chemistry, Duke University, Box 90346, Durham, NC 27708-0346, USA
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17
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Rish KR, Swartzlander R, Sadikot TN, Berridge MV, Smith A. Interaction of heme and heme-hemopexin with an extracellular oxidant system used to measure cell growth-associated plasma membrane electron transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1107-17. [PMID: 17643387 DOI: 10.1016/j.bbabio.2007.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 06/12/2007] [Accepted: 06/13/2007] [Indexed: 11/18/2022]
Abstract
Since redox active metals are often transported across membranes into cells in the reduced state, we have investigated whether exogenous ferri-heme or heme bound to hemopexin (HPX), which delivers heme to cells via receptor-mediated endocytosis, interact with a cell growth-associated plasma membrane electron transport (PMET) pathway. PMET reduces the cell-impermeable tetrazolium salt, WST-1, in the presence of the mandatory low potential intermediate electron acceptor, mPMS. In human promyelocytic (HL60) cells, protoheme (iron protoporphyrin IX; 2,4-vinyl), mesoheme (2,4-ethyl) and deuteroheme (2,4-H) inhibited reduction of WST-1/mPMS in a saturable manner supporting interaction with a finite number of high affinity acceptor sites (Kd 221 nM for naturally occurring protoheme). A requirement for the redox-active iron was shown using gallium-protoporphyrin IX (PPIX) and tin-PPIX. Heme-hemopexin, but not apo-hemopexin, also inhibited WST-1 reduction, and copper was required. Importantly, since neither heme nor heme-hemopexin replace mPMS as an intermediate electron acceptor and since inhibition of WST-1/mPMS reduction requires living cells, the experimental evidence supports the view that heme and heme-hemopexin interact with electrons from PMET. We therefore propose that heme and heme-hemopexin are natural substrates for this growth-associated electron transfer across the plasma membrane.
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Affiliation(s)
- Kimberly R Rish
- School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110-2499, USA
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18
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Natarajan R, Fisher BJ, Fowler AA. Hypoxia inducible factor-1 modulates hemin-induced IL-8 secretion in microvascular endothelium. Microvasc Res 2007; 73:163-72. [PMID: 17336340 DOI: 10.1016/j.mvr.2007.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 01/05/2007] [Accepted: 01/27/2007] [Indexed: 10/23/2022]
Abstract
Ischemia/Reperfusion injury and hemolysis are characterized by erythrocyte lysis and release of free heme into the microcirculation. Following substantial erythrocyte lysis, heme overwhelms circulatory heme-binding protein networks rapidly forming hemin, the oxidized form of iron protoporphyrin IX. Hemin's role in modulating inflammatory responses in microvascular endothelium (MVEC) remains ill-defined. We studied the impact of hemin exposure on human MVEC interleukin-8 (IL-8) expression. Hemin significantly up-regulated MVEC IL-8 secretion and was associated with cellular iron loading. Hemin-induced IL-8 up-regulation was significantly attenuated by increasing environmental serum concentrations. As well, hemin-induced IL-8 secretion was significantly reduced in a concentration-dependent fashion following pyrrolidine dithiocarbamate exposure, suggesting that induction occurred via an oxidant-sensitive mechanism. Interestingly, transfection studies revealed that oxidant-driven transcription factors NF-kappaB and AP-1 played no role in hemin-induced IL-8 transcription. In studies employing actinomycin D, hemin was found to dramatically lengthen IL-8 mRNA half-life. Of major importance in the current report was the finding that hypoxia inducible factor-1 (HIF-1), a powerful transcription factor mediating tissue responses to hypoxia, potently regulated hemin-induced IL-8 secretion in human MVEC. Activation of HIF-1 via the prolyl hydroxylase inhibitor dimethyloxalylglycine attenuated hemin-induced IL-8 secretion. These studies were confirmed via DNA-directed siRNA silencing of HIF-1alpha. In conclusion, hemin induces a serum protein-sensitive pro-inflammatory phenotype in MVEC via an oxidant-sensitive mechanism that is powerfully regulated by HIF-1.
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Affiliation(s)
- Ramesh Natarajan
- Division of Pulmonary Disease and Critical Care Medicine, Department of Internal Medicine, Virginia Commonwealth University Medical Center, Box 980050, Richmond, VA 23298, USA
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19
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Mense SM, Zhang L. Heme: a versatile signaling molecule controlling the activities of diverse regulators ranging from transcription factors to MAP kinases. Cell Res 2006; 16:681-92. [PMID: 16894358 DOI: 10.1038/sj.cr.7310086] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Heme (iron protoporphyrin IX) is an essential molecule for numerous living organisms. Not only does it serve as a prosthetic group in enzymes, it also acts as a signaling molecule that controls diverse molecular and cellular processes ranging from signal transduction to protein complex assembly. Deficient heme synthesis or function impacts the hematopoietic, hepatic and nervous systems in humans. Recent studies have revealed a series of heme-regulated transcription factors and signal transducers including Hap1, a heme-activated transcription factor that mediates the effects of oxygen on gene transcription in the yeast Saccharomyces cerevisiae; Bach1, a transcriptional repressor that is negatively regulated by heme in mammalian cells; IRR, an iron regulatory protein that mediates the iron-dependant regulation of heme synthesis in the bacterium Bradyrhizobium japonicum; and heme-regulated inhibitor, an eucaryotic initiation factor 2alpha kinase that coordinates protein synthesis with heme availability in reticulocytes. In this review, we summarize the current knowledge about how heme controls the activity of these transcriptional regulators and signal transducers, and discuss diseases associated with defective heme synthesis, degradation and function.
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Affiliation(s)
- Sarah M Mense
- Department of Environmental Health Sciences, Columbia University, Mailman School of Public Health, New York, NY 10032, USA
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20
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Latunde-Dada GO, Simpson RJ, McKie AT. Recent advances in mammalian haem transport. Trends Biochem Sci 2006; 31:182-8. [PMID: 16487711 DOI: 10.1016/j.tibs.2006.01.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 01/04/2006] [Accepted: 01/30/2006] [Indexed: 12/12/2022]
Abstract
Haem is a structural component of numerous cellular proteins and contributes greatly to iron metabolic processes in mammals. Haem-carrier protein 1 (HCP1) has recently been cloned and characterized as a putative transporter in the apical region of the duodenum, and is responsible for uptake of haem into the gut cells. Its expression is regulated pre- and post-translationally in hypoxic and iron-deficient mice, respectively. The identification of HCP1 has revealed the long-sought mechanism by which haem--an important source of dietary iron--is absorbed from the diet by the gut. Feline leukaemic virus receptor (FLCVR) and ABC transporter ABCG2, characterized in haematopoietic cells, have also recently been shown to export haem, particularly under stress. FLVCR protects developing erythroid cells from haem toxicity during the early stages of differentiation, and ABCG2 averts protoporphyrin accumulation (particularly under hypoxic conditions). These haem-efflux proteins are expressed in other cells and tissues including the intestine where they might function as apical haem exporters to prevent toxicity in the enterocytes.
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Affiliation(s)
- Gladys O Latunde-Dada
- Department of Biochemistry and Nutrition Sciences Research Division, King's College London, Franklin Wilkin's Building, 150 Stamford Street, London SE1 9NH, UK
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21
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Moore A, Merad Boudia M, Lehalle D, Massrieh W, Derjuga A, Blank V. Regulation of globin gene transcription by heme in erythroleukemia cells: analysis of putative heme regulatory motifs in the p45 NF-E2 transcription factor. Antioxid Redox Signal 2006; 8:68-75. [PMID: 16487039 DOI: 10.1089/ars.2006.8.68] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The function of the NF-E2 transcription factor, a p45/small Maf heterodimer, was analyzed in the erythroleukemia cell lines MEL and CB3. In contrast to MEL cells, CB3 cells are null for p45 and thus express only extremely low levels of adult globin transcripts upon induction by agents promoting erythroid differentiation. We investigated the response of erythroleukemia cells to hemin treatment. Hemin rapidly induces beta-globin gene transcript levels in MEL cells, but not in CB3 cells. Stable expression of the large p45 NF-E2 subunit in CB3 cells restores hemin mediated beta-globin gene transcription, suggesting that the presence of a functional NF-E2 is required for strong induction of beta-globin mRNA levels by hemin in erythroleukemia cells. We performed mutagenesis of two potential heme-regulatory motifs (HRMs) in p45 NF-E2 and found that the mutated versions are expressed and can still recognize a NF-E2 DNA binding element. In addition, we showed that p45 NF-E2 HRM mutants are able to restore beta-globin gene transcription in CB3 cells upon induction by hemin. Our results suggest that globin gene activation by heme appears to be independent of the putative HRMs in the p45 subunit of the NF-E2 transcription factor.
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Affiliation(s)
- Amy Moore
- Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada
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22
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Shayeghi M, Latunde-Dada GO, Oakhill JS, Laftah AH, Takeuchi K, Halliday N, Khan Y, Warley A, McCann FE, Hider RC, Frazer DM, Anderson GJ, Vulpe CD, Simpson RJ, McKie AT. Identification of an Intestinal Heme Transporter. Cell 2005; 122:789-801. [PMID: 16143108 DOI: 10.1016/j.cell.2005.06.025] [Citation(s) in RCA: 470] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 05/20/2005] [Accepted: 06/17/2005] [Indexed: 12/14/2022]
Abstract
Dietary heme iron is an important nutritional source of iron in carnivores and omnivores that is more readily absorbed than non-heme iron derived from vegetables and grain. Most heme is absorbed in the proximal intestine, with absorptive capacity decreasing distally. We utilized a subtractive hybridization approach to isolate a heme transporter from duodenum by taking advantage of the intestinal gradient for heme absorption. Here we show a membrane protein named HCP 1 (heme carrier protein 1), with homology to bacterial metal-tetracycline transporters, mediates heme uptake by cells in a temperature-dependent and saturable manner. HCP 1 mRNA was highly expressed in duodenum and regulated by hypoxia. HCP 1 protein was iron regulated and localized to the brush-border membrane of duodenal enterocytes in iron deficiency. Our data indicate that HCP 1 is the long-sought intestinal heme transporter.
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Affiliation(s)
- Majid Shayeghi
- Department of Life Sciences, Nutritional Sciences Research Division, Franklin-Wilkins Building, Kings College London, 150 Stamford Street, London SE1 9NN, UK
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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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Uc A, Stokes JB, Britigan BE. Heme transport exhibits polarity in Caco-2 cells: evidence for an active and membrane protein-mediated process. Am J Physiol Gastrointest Liver Physiol 2004; 287:G1150-7. [PMID: 15308469 DOI: 10.1152/ajpgi.00157.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Heme prosthetic groups are vital for all living organisms, but they can also promote cellular injury by generating reactive oxygen species. Therefore, intestinal heme absorption and distribution should be carefully regulated. Although a human intestine brush-border heme receptor/transporter has been suggested, the mechanism by which heme crosses the apical membrane is unknown. After it enters the cell, heme is degraded by heme oxygenase-1 (HO-1), and iron is released. We hypothesized that heme transport is actively regulated in Caco-2 cells. Cells exposed to hemin from the basolateral side demonstrated a higher HO-1 induction than cells exposed to hemin from the apical surface. Hemin secretion was more rapid than absorption, and net secretion occurred against a concentration gradient. Treatment of the apical membrane with trypsin increased hemin absorption by threefold, but basolateral treatment with trypsin had no effect on hemin secretion. Neither apical nor basolateral trypsin changed the paracellular pathway. We conclude that heme is acquired and transported in both absorptive and secretory directions in polarized Caco-2 cells. Secretion is via an active metabolic/transport process. Trypsin applied to the apical surface increased hemin absorption, suggesting that protease activity can uncover a process for heme uptake that is otherwise quiescent. These processes may be involved in preventing iron overload in humans.
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Affiliation(s)
- Aliye Uc
- Department of Pediatrics, Veterans Administration Medical Center, University of Iowa, Iowa City, IA 52242, USA.
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Ridderstråle Y, Fierke CA, Roush ED, Wistrand PJ. Localization of a protein inhibitor of carbonic anhydrase in pig tissues. ACTA PHYSIOLOGICA SCANDINAVICA 2002; 176:27-31. [PMID: 12193216 DOI: 10.1046/j.1365-201x.2002.01010.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The protein inhibitor of carbonic anhydrase (CA), pICA, was localized in pig tissues by an immunohistochemical technique, using rabbit antipICA IgG. Staining for pICA was found in liver sinusoids and kidney glomeruli, where phagocytic cells are located, i.e. Kupffer and mesangial cells, respectively. pICA was not found inside parenchymal cells, or in tissues from striated muscle, heart, eye or lung. It is concluded that the function of pICA is perhaps to bind the carbonic anhydrase isozymes CA I, II, and III, released from erythrocytes into the blood circulation by intravascular haemolysis. The complex of CA-pICA in plasma may then be transported to the reticuloendothelial system, for degradation and reclamation of CA-bound zinc. This would be similar to the fate of the haemoglobin-haptoglobin complex for the recycling of iron.
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Affiliation(s)
- Y Ridderstråle
- Department of Animal Physiology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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26
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Escriba PV, Morales P, Smith A. Membrane phospholipid reorganization differentially regulates metallothionein and heme oxygenase by heme-hemopexin. DNA Cell Biol 2002; 21:355-64. [PMID: 12042074 DOI: 10.1089/104454902753759762] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Heme-hemopexin coordinately regulates genes encoding protective proteins including metallothionein-I (MT-I) and heme oxygenase 1 (HO-1). Hexamethylene-bisacetamide (HMBA), which induces differentiation and activates protein kinase C (PKC), synergistically augments the induction of both MT-I and MT-II mRNAs in response to heme-hemopexin, but attenuates the induction of HO-1. HMBA also augments the increase in MT mRNA in response to cobalt protoporphyrin-hemopexin, a hemopexin (HPX) receptor ligand that activates signaling cascades without tetrapyrrole uptake. Unlike the PKC-activating phorbol esters that induce MT-I and HO-1, HMBA has minimal effects on MT-I or HO-1. HMBA is an amphipathic molecule, and is shown here to interact physically with lipids in model membranes using differential scanning calorimetry (DSC). The data are consistent with a stabilization of the lipid bilayer and an HMBA-induced segregation of lipids into separate domains each relatively enriched in one of the lipids. HMBA also perturbs membrane-protein interactions, and causes a loss of PKC and G-protein subunits from plasma membranes in vitro. Taken together, these observations reveal an additional level of complexity in the regulation of protective proteins induced by HPX, and which may take place in vivo in response to natural compounds that reorganize membrane phospholipids. A model is proposed whereby a reorganization of lipids by HMBA alters signaling pathways and fusion events considered to be the etiology of the differential response of the MT-1 (and MT-II) and the HO-1 genes to HMBA and heme-HPX.
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Affiliation(s)
- Pablo V Escriba
- Department of Biology, University of the Balearic Islands, 07071 Palma de Mallorca, Spain
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27
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Delanghe JR, Langlois MR. Hemopexin: a review of biological aspects and the role in laboratory medicine. Clin Chim Acta 2001; 312:13-23. [PMID: 11580905 DOI: 10.1016/s0009-8981(01)00586-1] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Hemopexin is a heme-binding plasma glycoprotein which, after haptoglobin, forms the second line of defense against hemoglobin-mediated oxidative damage during intravascular hemolysis. A decrease in plasma hemopexin concentration reflects a recent release of heme compounds in the extracellular compartment. Heme-hemopexin complexes are delivered to hepatocytes by receptor-mediated endocytosis after which hemopexin is recycled to the circulation. METHODS OF ANALYSIS Immunonephelometric and -turbidimetric hemopexin assays are available as more precise and rapid alternatives to the radial immunodiffusion technique. INTERPRETATIONS Hemopexin determinations are not subject to interference by in vitro hemolysis. Altered serum or plasma concentrations of hemopexin are found not only in hemolytic anemias but also in other conditions such as chronic neuromuscular diseases and acute intermittent porphyria. In laboratory medicine, while hemopexin determination in tandem with haptoglobin has potential applications in the assessment of intravascular hemolysis and allows for the monitoring of the severity of hemolysis after depletion of haptoglobin, its diagnostic utility is less clear in other pathological conditions. Further studies are necessary to fully establish the clinical significance of hemopexin determination.
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Affiliation(s)
- J R Delanghe
- Department of Clinical Chemistry, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
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28
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Monzani E, Bonafè B, Fallarini A, Redaelli C, Casella L, Minchiotti L, Galliano M. Enzymatic properties of human hemalbumin. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1547:302-12. [PMID: 11410286 DOI: 10.1016/s0167-4838(01)00192-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The binding of hemin to the primary site of human serum albumin (HSA) has been reinvestigated using UV-Vis, CD and NMR techniques. The major fraction of bound hemin contains a five-coordinated high-spin iron(III) center, but a minor fraction of the metal appears to be in a six-coordinated, low-spin state, where a 'distal' residue, possibly a second histidine residue, completes the coordination sphere. The reduced, iron(II) form of the adduct contains six-coordinated low-spin heme. The distal residue hinders the access to the iron(III) center of hemin-HSA to small anionic ligands like azide and cyanide and destabilizes the binding of neutral diatomics like dioxygen and carbon monoxide to the iron(II) form. In spite of these limitations, the hemin-HSA complex promotes hydrogen peroxide activation processes that bear the characteristics of enzymatic reactions and may have biological relevance. The complex is in fact capable of catalyzing peroxidative reactions on phenolic compounds related to tyrosine and hydrogen peroxide dismutation. Kinetic and mechanistic studies confirm that the low efficiency with which peroxidative processes occur depends on the limited rate of the reaction between hydrogen peroxide and the iron(III) center, to form the active species, and by the competitive peroxide degradation reaction.
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Affiliation(s)
- E Monzani
- Dipartimento di Chimica Generale, Università di Pavia, Italy
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29
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Morgan WT, Smith A. Binding and transport of iron-porphyrins by hemopexin. ADVANCES IN INORGANIC CHEMISTRY 2000. [DOI: 10.1016/s0898-8838(00)51004-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Hemopexin (Hx) is a plasma glycoprotein mainly expressed in liver and, less abundantly, in the central and peripheral nervous systems. Hx has a high binding affinity with heme and is considered to be a major transport vehicle of heme into the liver, thus preventing both heme-catalyzed oxidative damage and heme-bound iron loss. To determine the physiologic relevance of heme-Hx complex formation, Hx-deficient mice were generated by homologous recombination in embryonic stem (ES) cells. The Hx-deficient mice were viable and fertile. Their plasma iron level and blood parameters were comparable to those of control mice and they showed no evidence of tissue lesions caused by oxidative damage or abnormal iron deposits. Moreover, they were sensitive to acute hemolysis, as are wild-type mice. Nevertheless, Hx-null mice recovered more slowly after hemolysis and were seen to have more severe renal damage than controls. After hemolytic stimulus, Hx-deficient mice presented prolonged hemoglobinuria with a higher kidney iron load and higher lipid peroxidation than control mice. Moreover, Hx-null mice showed altered posthemolysis haptoglobin (Hp) turnover in as much as Hp persisted in the circulation after hemolytic stimulus. These data indicate that, although Hx is not crucial either for iron metabolism or as a protection against oxidative stress under physiologic conditions, it does play an important protective role after hemolytic processes.
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Abstract
AbstractHemopexin (Hx) is a plasma glycoprotein mainly expressed in liver and, less abundantly, in the central and peripheral nervous systems. Hx has a high binding affinity with heme and is considered to be a major transport vehicle of heme into the liver, thus preventing both heme-catalyzed oxidative damage and heme-bound iron loss. To determine the physiologic relevance of heme-Hx complex formation, Hx-deficient mice were generated by homologous recombination in embryonic stem (ES) cells. The Hx-deficient mice were viable and fertile. Their plasma iron level and blood parameters were comparable to those of control mice and they showed no evidence of tissue lesions caused by oxidative damage or abnormal iron deposits. Moreover, they were sensitive to acute hemolysis, as are wild-type mice. Nevertheless, Hx-null mice recovered more slowly after hemolysis and were seen to have more severe renal damage than controls. After hemolytic stimulus, Hx-deficient mice presented prolonged hemoglobinuria with a higher kidney iron load and higher lipid peroxidation than control mice. Moreover, Hx-null mice showed altered posthemolysis haptoglobin (Hp) turnover in as much as Hp persisted in the circulation after hemolytic stimulus. These data indicate that, although Hx is not crucial either for iron metabolism or as a protection against oxidative stress under physiologic conditions, it does play an important protective role after hemolytic processes.
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32
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Yabe Y, Koyama Y, Nishikawa M, Takakura Y, Hashida M. Hepatocyte-specific distribution of catalase and its inhibitory effect on hepatic ischemia/reperfusion injury in mice. Free Radic Res 1999; 30:265-74. [PMID: 10230805 DOI: 10.1080/10715769900300291] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To explore the possibility of using catalase for the treatment of reactive oxygen species (ROS)-mediated injuries, the pharmacokinetics of bovine liver catalase (CAT) labeled with 111In was investigated in mice. At a dose of 0.1 mg/kg, more than 70% of 111In-CAT was recovered in the liver within 10 min after intravenous injection. In addition, 111In-CAT was predominantly recovered from the parenchymal cells (PC) in the liver. Increasing the dose retarded the hepatic uptake of 111In-CAT, suggesting saturation of the uptake process. This cell-specific uptake could not be inhibited by coadministration of various compounds which are known to be taken up by liver PC, indicating that the uptake mechanism of CAT by PC is very specific to this compound. The preventive effect of CAT on a hepatic ischemia/reperfusion injury was examined in mice by measuring the GOT and GPT levels in plasma. A bolus injection of CAT at 5 min prior to the reperfusion attenuated the increase in the levels of these indicators in a dose-dependent manner. These results suggest that catalase can be used for various hepatic injuries caused by ROS.
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Affiliation(s)
- Y Yabe
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan
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33
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Brass CA, Immenschuh S, Song DX, Liem HH, Eberhard UM. Hemopexin decreases spontaneous chemiluminescence of cold preserved liver after reperfusion. Biochem Biophys Res Commun 1998; 248:574-7. [PMID: 9703968 DOI: 10.1006/bbrc.1998.9023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hemopexin is a plasma protein with exceptionally high affinity for heme. During liver transplantation heme is released via lysis of transfused blood. This heme may catalyze peroxidative reactions that contribute to "reperfusion" injury of the organ. Using a rat liver model of cold storage and reperfusion we tested the potential anti-oxidant effects of hemopexin. After 3 h of cold storage rat liver was reperfused with warm oxygenated buffer. Spontaneous liver chemiluminescence, which is a parameter of oxyradical production, was measured during reperfusion and expressed as an index of free radical production (IFRP). Chemiluminescence reached a maximum within 5 min of reperfusion and decreased to baseline within 30 min. Addition of hemopexin to the perfusate (5 microM) significantly decreased the IFRP. By contrast, the control proteins albumin and gamma-globulin (10 microM) had a smaller non-significant effect. The data suggest that heme could be complexed by hemopexin during reperfusion, thus inhibiting heme mediated cellular injury.
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Affiliation(s)
- C A Brass
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, USA
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34
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Noyer CM, Immenschuh S, Liem HH, Muller-Eberhard U, Wolkoff AW. Initial heme uptake from albumin by short-term cultured rat hepatocytes is mediated by a transport mechanism differing from that of other organic anions. Hepatology 1998; 28:150-5. [PMID: 9657107 DOI: 10.1002/hep.510280120] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Although it is known that circulating heme accumulates in liver cells, the process by which heme enters hepatocytes is only partly understood. Hemopexin and a putative hemopexin receptor on hepatocyte membranes may mediate the uptake process. However, whether there are sufficient hemopexin receptors on rat hepatocytes to account for the bulk of heme entering cells is unknown. It is likely that heme may be transferred directly from albumin with the help of a plasma membrane heme transporter. To clarify the transport mechanism of heme into liver cells, we studied the uptake by short-term cultured rat hepatocytes of 55Fe-heme incubated with rat serum albumin. In these cells, the initial uptake of 55Fe-heme at 37 degrees C was five- to eightfold higher than that at 4 degrees C, linear for at least 5 minutes, and saturable. The Km of heme uptake was 0.95 +/- 0.27 micromol/L, and the Vmax was 0.12 +/- 0.01 pmol/min/mg protein (n = 3). Neither isosmotic substitution of sucrose for NaCl in the medium nor adenosine triphosphate (ATP) depletion, perturbations that are known to reduce uptake of bilirubin, sulfobromophthalein (BSP), and taurocholate, had any influence on 55Fe-heme uptake. In addition, heme uptake was not reduced in the presence of a greater than 500-fold molar excess of BSP. These results indicate that hepatocytes take up heme by a process that is distinct from that of these other organic anions.
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Affiliation(s)
- C M Noyer
- Department of Medicine, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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35
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Taketani S, Immenschuh S, Go S, Sinclair PR, Stockert RJ, Liem HH, Muller Eberhard U. Hemopexin from four species inhibits the association of heme with cultured hepatoma cells or primary rat hepatocytes exhibiting a small number of species specific hemopexin receptors. Hepatology 1998; 27:808-14. [PMID: 9500711 DOI: 10.1002/hep.510270324] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Hemopexin (Hx) binds heme with a very high affinity (Kd<0.1 pmol/L). It has been implicated as a major vehicle for the transport of heme into liver cells, involving a receptor-mediated recycling mechanism. However, previous studies indicated that heme is not taken up by cultured embryonic chick or adult rat hepatocytes by such a mechanism, because heme added as heme hemopexin failed to affect heme-responsive activities of 5-aminolevulinic acid synthase and heme oxygenase. Here, we investigated the importance of hemopexin in hepatic heme uptake in cultured rat hepatocytes and human HepG2 hepatoma cells, and determined the number and species specificity of hemopexin receptors on the rat hepatocytes. We also tested whether there is a difference between heterologous and homologous hemopexins. We found the following: 1) heme is inhibited from associating with hepatocytes by apo hemopexins from rat, human, rabbit, and chicken; 2) heme readily associates with hepatocytes when heme hemopexin preparations are added in which the ratio of heme to hemopexin exceeds 1.0; 3) heme induces heme oxygenase mRNA in rat hepatocytes and this induction is prevented by excess hemopexin; and 4) rat hepatocytes exhibit only about 2,000 hemopexin receptors per cell when using rat hemopexin, and none when using hemopexin of rabbit and human. We conclude that hemopexin plays a limited role in heme uptake by cultured hepatocytes and hepatoma cells, and that heme which exceeds the hemopexin binding capacity is taken up directly from heme-albumin.
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Affiliation(s)
- S Taketani
- Kansai Medical University, Moriguchi, Osaka, Japan
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36
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Smith A, Eskew JD, Borza CM, Pendrak M, Hunt RC. Role of heme-hemopexin in human T-lymphocyte proliferation. Exp Cell Res 1997; 232:246-54. [PMID: 9168799 DOI: 10.1006/excr.1997.3526] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Heme-hemopexin supports and stimulates proliferation of human acute T-lymphoblastic (MOLT-3) cells, suggesting the participation of heme in cell growth and division. MOLT-3 cells express approximately 58,000 hemopexin receptors per cell (apparent Kd 20 nM), of which about 20% are on the cell surface. Binding is dose- and temperature-dependent, and growth in serum-free IMDM medium is stimulated by 100-1000 nM heme-hemopexin, consistent with the high affinity of the receptor for hemopexin, and maximal growth is seen in response to 500 nM complex. Growth was similar in defined minimal medium supplemented with either low concentrations of heme-hemopexin or iron-transferrin, and either of these complexes were about 80% as effective as a serum supplement. Heme-hemopexin, but not apo-hemopexin, reversed the growth inhibition caused by desferrioxamine showing that heme-iron derived from heme catabolism is used for cell growth. Cobalt-protoporphyrin (CoPP)-hemopexin, which binds to the receptor but is not transported intracellularly [Smith et al., (1993) J. Biol. Chem. 268, 7365], also stimulated cell proliferation in serum-free IMDM but did not "rescue" the cells from desferrioxamine. Furthermore, CoPP-hemopexin effectively competed for the hemopexin receptor with heme-hemopexin and diminished its growth stimulatory effects. In addition, protein kinase C (PKC) is translocated to the plasma membrane within 5 min after heme-hemopexin is added to the medium, reaches maximum activity within 5-10 min, and declines to unstimulated levels by 30 min. Heme-hemopexin and CoPP-hemopexin both augmented MOLT-3 cell growth stimulated by serum. Thus, heme-hemopexin not only functions as an iron source for T-cells but occupancy of the hemopexin receptor itself triggers signaling pathway(s) involved in the regulation of cell growth. The stimulation of growth of human T-lymphocytes by heme-hemopexin is likely to be a physiologically relevant mechanism at sites of injury, infection, and inflammation.
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Affiliation(s)
- A Smith
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City 64110-2499, USA.
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37
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Miller YI, Felikman Y, Shaklai N. The involvement of low-density lipoprotein in hemin transport potentiates peroxidative damage. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1272:119-27. [PMID: 7548235 DOI: 10.1016/0925-4439(95)00075-f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Hemin binds to isolated low-density lipoprotein (LDL) and thereby triggers LDL oxidation. In this study we investigated whether hemin can get together with LDL under physiological conditions. The relative affinity of three blood components to free hemin was as follows: RBCM < LDL < albumin. At physiological molar ratio of LDL/albumin all the hemin was bound to albumin. In molar excess of albumin over hemin, existing even under pathological conditions, albumin served as an efficient antioxidant for the plasma hemin-induced LDL oxidation. RBCM-embedded hemin, unlike plasma hemin, affected LDL: the mobile hemin was transferred from RBCM to LDL in the absence of albumin, whereas in the presence of albumin most of the mobile hemin finally reached the albumin but partially via LDL. Thus, a transient hemin is built up in LDL. This transient hemin triggered LDL oxidation which was not inhibited but rather promoted by albumin. The involvement of albumin in this oxidation was explained by its acting as a pump thereby increasing the transient hemin in LDL. It is suggested that increased membrane hemin level as in hemoglobinopathies and/or excess LDL in dyslipidemia provide conditions for hemin-induced LDL oxidation.
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Affiliation(s)
- Y I Miller
- Sackler Institute of Molecular Medicine, Sackler Faculty of Medicine, Tel-Aviv University, Israel
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Wu ML, Morgan WT. Thermodynamics of heme-induced conformational changes in hemopexin: role of domain-domain interactions. Protein Sci 1995; 4:29-34. [PMID: 7773173 PMCID: PMC2142961 DOI: 10.1002/pro.5560040105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hemopexin is a serum glycoprotein that binds heme with high affinity and delivers heme to the liver cells via receptor-mediated endocytosis. A hinge region connects the two non-disulfide-linked domains of hemopexin, a 35-kDa N-terminal domain (domain I) that binds heme, and a 25-kDa C-terminal domain (domain II). Although domain II does not bind heme, it assumes one structural state in apo-hemopexin and another in heme-hemopexin, and this change is important in facilitating the association of heme-hemopexin with its receptor. In order to elucidate the structure and function of hemopexin, it is important to understand how structural information is transmitted to domain II when domain I binds heme. Here we report a study of the protein-protein interactions between domain I and domain II using analytical ultracentrifugation and isothermal titration calorimetry. Sedimentation equilibrium analysis showed that domain I associates with domain II both in the presence and absence of heme with Kd values of 0.8 microM and 55 microM, respectively. The interaction between heme-domain I and domain II has a calorimetric enthalpy of +11 kcal/mol, a heat capacity (delta Cp) of -720 cal/mol.K, and a calculated entropy of +65 cal/mol.K. By varying the temperature of the centrifugation equilibrium runs, a van't Hoff plot with an apparent change in enthalpy (delta H) of -3.6 kcal/mol and change in entropy (delta S) of +8.1 cal/mol.K for the association of apo-domain I with domain II was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M L Wu
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City 64110, USA
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39
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Wu ML, Morgan WT. Conformational analysis of hemopexin by Fourier-transform infrared and circular dichroism spectroscopy. Proteins 1994; 20:185-90. [PMID: 7846027 DOI: 10.1002/prot.340200208] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hemopexin is a serum glycoprotein that binds heme with the highest known affinity of any characterized heme-binding protein and plays an important role in receptor-mediated cellular heme uptake. Complete understanding of the function of hemopexin will require the elucidation of its molecular structure. Previous analysis of the secondary structure of hemopexin by far-UV circular dichroism (CD) failed due to the unusual positive ellipticity of this protein at 233 nm. In this paper, we present an examination of the structure of hemopexin by both Fourier-transform infrared (FTIR) and circular dichroism spectroscopy. Our studies show that hemopexin contains about 55% beta-structure, 15% alpha-helix, and 20% turns. The two isolated structural domains of hemopexin each have secondary structures similar to hemopexin. Although there are significant tertiary conformational changes indicated by the CD spectra, the overall secondary structure of hemopexin is not affected by binding heme. However, moderate changes in secondary structure do occur when the heme-binding domain of hemopexin associates with heme. In spite of the exceptionally tight binding at neutral pH, heme is released from the bis-histidyl heme-hemopexin complex at pH 5.0. Under this acidic condition, hemopexin maintains the same overall secondary structure as the native protein and is able to resume the heme-binding function and the native structure of the heme-protein (as indicated by the CD spectra) when returned to neutral pH. We propose that the state of hemopexin identified in vitro at pH 5.0 resembles that of this protein in the acidic environment of the endosomes in vivo when hemopexin releases heme during receptor-mediated endocytosis.
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Affiliation(s)
- M L Wu
- Division of Moelcular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City 64110
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40
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Identification of a liver preference enhancer element of the rat hemopexin gene and its interaction with nuclear factors. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37453-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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41
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Identification of the histidine residues of hemopexin that coordinate with heme-iron and of a receptor-binding region. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53247-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Affiliation(s)
- U Muller-Eberhard
- Department of Pediatrics/Hematology-Oncology, Cornell University Medical College, New York, NY 10021
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44
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Hrkal Z, Cabart P, Kalousek I. Isolation of human haemopexin in apo-form by chromatography on S-Sepharose Fast Flow and Blue Sepharose CL-6B. Biomed Chromatogr 1992; 6:212-4. [PMID: 1643392 DOI: 10.1002/bmc.1130060412] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Z Hrkal
- Institute of Haematology and Blood Transfusion, Prague, Czechoslovakia
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45
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Muster P, Tatum F, Smith A, Morgan WT. Further characterization of structural determinants of rabbit hemopexin function. JOURNAL OF PROTEIN CHEMISTRY 1991; 10:123-8. [PMID: 2054057 DOI: 10.1007/bf01024662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To further identify structural features of the hemopexin molecule important for its heme transport function, a fragment of the heme-binding domain (residues 1-213, Mr 35 kD, domain I) of rabbit hemopexin was obtained after digestion with subtilisin. Both apo- and heme-domain I were cleaved by subtilisin, and the subtilisin-digested form of domain I (called SD-DI) was shown by microsequencing to have been cleaved at Asp 22 forming a 30 kD subfragment lacking the conserved histidine residue at position 7 and the N-linked oligosaccharide at Asn 9. The 5 kD peptide cleaved from domain I is not disulfide linked to domain I and can be removed by membrane ultrafiltration. SD-DI retains the ability of domain I to bind heme, to associate with the other functional domain of hemopexin (domain II), and to interact with the hemopexin receptor on mouse Hepa cells. Moreover, although the heme complex of SD-DI is less thermostable than native heme-domain I, like heme-domain I, heme-SD-DI is stabilized to a large extent when associated with domain II. These results show that the conserved His 7 residue is not involved in heme binding by hemopexin and that residues 1-22 of hemopexin and the N-linked oligosaccharide at Asn 9 are not essential for either receptor binding or interdomain interactions. Nevertheless, these N-terminal residues of hemopexin do contribute significantly to the overall stability of the hemopexin molecule and the interdomain interactions necessary for receptor recognition.
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Affiliation(s)
- P Muster
- Division of Molecular Biology and Biochemistry, School of Basic Life Sciences, University of Missouri-Kansas City 64110
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Abstract
The liver's pivotal role in the homeostasis of essential trace metals and detoxification of exogenous metals is attributed to its ability to efficiently extract metals from plasma, metabolize, store, and redistribute them in various forms either into bile or back into the bloodstream. Bidirectional transport across the sinusoidal plasma membrane allows the liver to control plasma concentrations and therefore availability to other tissues. In contrast, transport across the canalicular membrane is largely, but not exclusively, unidirectional and is a major excretory pathway. Although each metal has relatively distinct hepatic transport characteristics, some generalizations can be made. First, movement of metals from plasma to bile follows primarily a transcellular route. The roles of the paracellular pathway and of ductular secretion appear minimal. Second, intracellular binding proteins and in particular metallothionein play only indirect roles in transmembrane flux. The amounts of metallothionein normally secreted into plasma and bile are quite small and cannot account for total metal efflux. Third, metals traverse liver cell plasma membranes largely by facilitated diffusion, and by fluid-phase, adsorptive, and receptor-mediated endocytosis/exocytosis. There is currently no evidence for primary active transport. Because of the high rate of hepatocellular membrane turnover, metal transport via endocytic vesicles probably makes a larger contribution than previously recognized. Finally, there is significant overlap in substrate specificity on the putative membrane carriers for the essential trace metals. For example, zinc and copper share many transport characteristics and apparently compete for at least one common transport pathway. Similarly, canalicular transport of five of the metals discussed in this overview (Cu, Zn, Cd, Hg, and Pb) is linked to biliary GSH excretion. These metals may be transported as GSH complexes by the canalicular glutathione transport system(s). Unfortunately, none of the putative membrane carrier proteins have been studied at the subcellular or molecular level. Our knowledge of their biochemical properties is rudimentary and rests almost entirely on indirect evidence obtained in vivo or in intact cell systems. The challenge for the future is to isolate and characterize these putative metal carriers, and to determine how they are functionally regulated.
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Affiliation(s)
- N Ballatori
- Department of Biophysics, University of Rochester School of Medicine, New York 14642
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Taketani S, Kohno H, Sawamura T, Tokunaga R. Hemopexin-dependent down-regulation of expression of the human transferrin receptor. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)77445-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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48
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Abstract
Utilizing high specific activity [55Fe]hemin, the interaction of heme with monolayer cultures of human Hep G2 hepatoblastoma cells was examined. Initial characterization was performed at 4 degrees C to minimize the possibility of heme internalization. Specific binding of [55Fe]hemin at 4 degrees C reached equilibrium within 6 h and was 66% dissociable after 18 h in the presence of fresh binding buffer. Stereospecificity of the binding interaction was evidenced by variable degrees of competition with different metalloporphyrins. Scatchard analysis revealed a Ka of 0.01 nM-1 and the number of binding sites per cell was approx. 200,000. Elevation of the temperature during binding to 22 degrees C resulted in a small decrease in the affinity of the interaction and the apparent number of sites per cell was doubled, possibly due to artefactual elevation of the cell-associated radioactivity secondary to intracellular accumulation. These data are interpreted to indicate the presence of a specific heme receptor on the plasmalemma of Hep G2 cells.
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Affiliation(s)
- R A Galbraith
- Department of Metabolism/Pharmacology, Rockefeller University Hospital, New York, NY 10021
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Ades IZ. Heme production in animal tissues: the regulation of biogenesis of delta-aminolevulinate synthase. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:565-78. [PMID: 2199251 DOI: 10.1016/0020-711x(90)90032-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- I Z Ades
- Department of Zoology, University of Maryland, College Park 20742
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50
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Spencer HT, Pete MJ, Babin DR. Structural studies on porcine hemopexin. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:367-77. [PMID: 2338162 DOI: 10.1016/0020-711x(90)90139-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. Porcine hemopexin was isolated from the serum of a single animal and purified to homogeneity. 2. Porcine hemopexin has an apparent Mw of 67,000, binds heme in a 1:1 molar ratio and consists of 24% N-linked oligosaccharides. The amino acid composition of porcine hemopexin compares well with the amino acid composition of human and rabbit hemopexins. 3. Limited tryptic hydrolysis of apohemopexin generates stable peptides of apparent Mw 42,000, 25,000, 24,000 and 21,000. The tryptic peptide of apparent Mw 42,000 (peptide I) binds heme in a 1:1 molar ratio, consists of 33% N-linked oligosaccharides and is derived from the amino terminal of intact hemopexin. The three peptides of smaller-Mw (collectively peptide II) represent the carboxyl terminal half of hemopexin, do not contain N-linked oligosaccharides and have no heme-binding capability. The Mw heterogeneity of peptide II is likely due to cleavage at secondary sites. 4. Under nondissociating electrophoresis two bands are resolved for hemopexin and peptide I, indicating the possibility of polymorphism in porcine hemopexin.
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Affiliation(s)
- H T Spencer
- Department of Biological Chemistry, Creighton University School of Medicine, Omaha, NE 68178
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