Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging
Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional <i>Alox</i> genes and the encoded enzymes share a high degree of amino acid conservation with their human orth...
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MDPI AG
2022-06-01
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| Series: | Biomedicines |
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| Online Access: | https://www.mdpi.com/2227-9059/10/6/1379 |
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| author | Marjann Schäfer Kumar R. Kakularam Florian Reisch Michael Rothe Sabine Stehling Dagmar Heydeck Gerhard P. Püschel Hartmut Kuhn |
| author_facet | Marjann Schäfer Kumar R. Kakularam Florian Reisch Michael Rothe Sabine Stehling Dagmar Heydeck Gerhard P. Püschel Hartmut Kuhn |
| author_sort | Marjann Schäfer |
| collection | DOAJ |
| description | Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional <i>Alox</i> genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15<i>S</i>-HpETE), whereas 8<i>S</i>-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created <i>Alox15b</i> knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male <i>Alox15b</i>-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male <i>Alox15b</i>-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest. |
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| last_indexed | 2024-03-10T00:21:11Z |
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| series | Biomedicines |
| spelling | doaj.art-c1e651eeeda34a91864c162c101576b82023-11-23T15:43:46ZengMDPI AGBiomedicines2227-90592022-06-01106137910.3390/biomedicines10061379Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When AgingMarjann Schäfer0Kumar R. Kakularam1Florian Reisch2Michael Rothe3Sabine Stehling4Dagmar Heydeck5Gerhard P. Püschel6Hartmut Kuhn7Department of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyLipidomix GmbH, Robert-Rössle-Straße 10, 13125 Berlin, GermanyDepartment of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyDepartment of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyInstitute for Nutritional Sciences, University Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Potsdam, GermanyDepartment of Biochemistry, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, GermanyMammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional <i>Alox</i> genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15<i>S</i>-HpETE), whereas 8<i>S</i>-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created <i>Alox15b</i> knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male <i>Alox15b</i>-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male <i>Alox15b</i>-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.https://www.mdpi.com/2227-9059/10/6/1379eicosanoidslipid peroxidationoxidative stresspolyenoic fatty acidserythropoiesis |
| spellingShingle | Marjann Schäfer Kumar R. Kakularam Florian Reisch Michael Rothe Sabine Stehling Dagmar Heydeck Gerhard P. Püschel Hartmut Kuhn Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging Biomedicines eicosanoids lipid peroxidation oxidative stress polyenoic fatty acids erythropoiesis |
| title | Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging |
| title_full | Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging |
| title_fullStr | Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging |
| title_full_unstemmed | Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging |
| title_short | Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging |
| title_sort | male knock in mice expressing an arachidonic acid lipoxygenase 15b alox15b with humanized reaction specificity are prematurely growth arrested when aging |
| topic | eicosanoids lipid peroxidation oxidative stress polyenoic fatty acids erythropoiesis |
| url | https://www.mdpi.com/2227-9059/10/6/1379 |
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