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Häfner AK, Beilstein K, Graab P, Ball AK, Saul MJ, Hofmann B, Steinhilber D. Identification and Characterization of a New Protein Isoform of Human 5-Lipoxygenase. PLoS One 2016; 11:e0166591. [PMID: 27855198 PMCID: PMC5113960 DOI: 10.1371/journal.pone.0166591] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/31/2016] [Indexed: 11/18/2022] Open
Abstract
Leukotrienes (LTs) are inflammatory mediators that play a pivotal role in many diseases like asthma bronchiale, atherosclerosis and in various types of cancer. The key enzyme for generation of LTs is the 5-lipoxygenase (5-LO). Here, we present a novel putative protein isoform of human 5-LO that lacks exon 4, termed 5-LOΔ4, identified in cells of lymphoid origin, namely the Burkitt lymphoma cell lines Raji and BL41 as well as primary B and T cells. Deletion of exon 4 does not shift the reading frame and therefore the mRNA is not subjected to non-mediated mRNA decay (NMD). By eliminating exon 4, the amino acids Trp144 until Ala184 are omitted in the corresponding protein. Transfection of HEK293T cells with a 5-LOΔ4 expression plasmid led to expression of the corresponding protein which suggests that the 5-LOΔ4 isoform is a stable protein in eukaryotic cells. We were also able to obtain soluble protein after expression in E. coli and purification. The isoform itself lacks canonical enzymatic activity as it misses the non-heme iron but it still retains ATP-binding affinity. Differential scanning fluorimetric analysis shows two transitions, corresponding to the two domains of 5-LO. Whilst the catalytic domain of 5-LO WT is destabilized by calcium, addition of calcium has no influence on the catalytic domain of 5-LOΔ4. Furthermore, we investigated the influence of 5-LOΔ4 on the activity of 5-LO WT and proved that it stimulates 5-LO product formation at low protein concentrations. Therefore regulation of 5-LO by its isoform 5-LOΔ4 might represent a novel mechanism of controlling the biosynthesis of lipid mediators.
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Affiliation(s)
- Ann-Kathrin Häfner
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- * E-mail: (DS); (A-KH)
| | - Kim Beilstein
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Philipp Graab
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Ann-Katrin Ball
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Meike J. Saul
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- Department of Biology, Technical University of Darmstadt, 64287, Darmstadt, Germany
| | - Bettina Hofmann
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
- * E-mail: (DS); (A-KH)
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Lehmann C, Homann J, Ball AK, Blöcher R, Kleinschmidt TK, Basavarajappa D, Angioni C, Ferreirós N, Häfner AK, Rådmark O, Proschak E, Haeggström JZ, Geisslinger G, Parnham MJ, Steinhilber D, Kahnt AS. Lipoxin and resolvin biosynthesis is dependent on 5-lipoxygenase activating protein. FASEB J 2015; 29:5029-43. [PMID: 26289316 DOI: 10.1096/fj.15-275487] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/13/2015] [Indexed: 12/13/2022]
Abstract
Resolution of acute inflammation is an active process coordinated by proresolving lipid mediators (SPMs) such as lipoxins (LXs) and resolvins (Rvs), which are formed by the concerted action of 2 lipoxygenases (LOs). Because the exact molecular mechanisms of SPM biosynthesis are not completely understood, we aimed to investigate LX and D-type Rv formation in human leukocytes and HEK293T cells overexpressing leukotriene (LT) pathway enzymes. Activity assays in precursor (15-hydroxyeicosatetraenoic acids, 17-HDoHE)-treated granulocytes [polymorphonuclear leukocytes (PMNLs)] showed a strict dependence of LXA4/RvD1 biosynthesis on cell integrity, and incubation with recombinant human 5-LO did not lead to LX or Rv formation. Pharmacologic inhibition of 5-LO activating protein (FLAP) by MK-886 inhibited LXA4/RvD1 biosynthesis in precursor-treated PMNLs (drug concentration causing 50% inhibition ∼ 0.3/0.2 µM), as did knockdown of the enzyme in MM6 cells, and precursor-treated HEK293T overexpressing 5-LO produced high amounts of LXA4 only in the presence of FLAP. In addition, inhibition of cytosolic phospholipase A2α (cPLA2α) interfered with LXA4/RvD1 formation from exogenous precursors in PMNLs. Furthermore, inhibition of the LT synthases LTA4 hydrolase and LTC4 synthase in PMNL/platelet coincubations augmented LXA4 levels. These findings show that several enzymes known to be involved in the biosynthesis of proinflammatory LTs, such as FLAP and cPLA2α, also contribute to LX and Rv formation.
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Affiliation(s)
- Christoph Lehmann
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Julia Homann
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Ann-Katrin Ball
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - René Blöcher
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Thea K Kleinschmidt
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Devaraj Basavarajappa
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Carlo Angioni
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Nerea Ferreirós
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Ann-Kathrin Häfner
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Olof Rådmark
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Ewgenij Proschak
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Jesper Z Haeggström
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Gerd Geisslinger
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Michael J Parnham
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Dieter Steinhilber
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | - Astrid Stefanie Kahnt
- *Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Institute of Clinical Pharmacology, Pharmazentrum Frankfurt, and Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany; and Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
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Hofmann B, Rödl CB, Kahnt AS, Maier TJ, Michel AA, Hoffmann M, Rau O, Awwad K, Pellowska M, Wurglics M, Wacker M, Zivković A, Fleming I, Schubert-Zsilavecz M, Stark H, Schneider G, Steinhilber D. Molecular pharmacological profile of a novel thiazolinone-based direct and selective 5-lipoxygenase inhibitor. Br J Pharmacol 2012; 165:2304-13. [PMID: 21955369 DOI: 10.1111/j.1476-5381.2011.01707.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The potency of many 5-lipoxygenase (5-LOX) inhibitors depends on the cellular peroxide tone and the mechanism of 5-LOX enzyme activation. Therefore, new inhibitors that act regardless of the mode of enzyme activation need to be developed. Recently, we identified a novel class of thiazolinone-based compounds as potent 5-LOX inhibitors. Here, we present the molecular pharmacological profile of (Z)-5-(4-methoxybenzylidene)-2-(p-tolyl)-5H-thiazol-4-one, compound C06. EXPERIMENTAL APPROACH Inhibition of 5-LOX product formation was determined in intact cells [polymorphonuclear leukocytes (PMNL), rat basophilic leukaemia-1, RAW264.7] and in cell-free assays [homogenates, 100, 000×g supernatant (S100), partially purified 5-LOX] applying different stimuli for 5-LOX activation. Inhibition of peroxisome proliferator-activated receptor (PPAR), cytosolic phospholipase A(2) (cPLA(2) ), 12-LOX, 15-LOX-1 and 15-LOX-2 as well as cyclooxygenase-2 (COX-2) were measured in vitro. KEY RESULTS C06 induced non-cytotoxic, direct 5-LOX inhibition with IC(50) values about 0.66 µM (intact PMNL, PMNL homogenates) and approximately 0.3 µM (cell-free PMNL S100, partially purified 5-LOX). Action of C06 was independent of the stimulus used for 5-LOX activation and cellular redox tone and was selective for 5-LOX compared with other arachidonic acid binding proteins (PPAR, cPLA(2) , 12-LOX, 15-LOX-1, 15-LOX-2, COX-2). Experimental results suggest an allosteric binding distinct from the active site and the C2-like domain of 5-LOX. CONCLUSIONS AND IMPLICATIONS C06 was identified as a potent selective direct 5-LOX inhibitor exhibiting a novel and unique mode of action, different from other established 5-LOX inhibitors. This thiazolinone may possess potential for intervention with inflammatory and allergic diseases and certain types of cancer.
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Affiliation(s)
- B Hofmann
- Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany.
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