Inactivation of anoctamin-6/Tmem16f, a regulator of phosphatidylserine scrambling in osteoblasts, leads to decreased mineral deposition in skeletal tissues

Authors

  • Harald WA Ehlen,

    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
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    • The first two authors contributed equally to this work.

  • Milana Chinenkova,

    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
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    • The first two authors contributed equally to this work.

  • Markus Moser,

    1. Department for Molecular Medicine, Max Planck Institute for Biochemistry, Martinsried, Germany
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  • Hans-Markus Munter,

    1. Otto-Warburg-Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany
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  • Yvonne Krause,

    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
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  • Stefanie Gross,

    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
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  • Bent Brachvogel,

    1. Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
    2. Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
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  • Manuela Wuelling,

    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
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  • Uwe Kornak,

    1. Development and Disease Research Group, Max Planck Institute for Molecular Genetics, Berlin, Germany
    2. Institut für Medizinische Genetik und Humangenetik, Charité-Universitätsmedizin Berlin, Berlin, Germany
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  • Andrea Vortkamp

    Corresponding author
    1. Department of Developmental Biology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
    2. Center for Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany
    3. Otto-Warburg-Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany
    • University of Duisburg-Essen, Center for Medical Biotechnology, Universitätsstr. 2, D-45117 Essen, Germany.
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Abstract

During vertebrate skeletal development, osteoblasts produce a mineralized bone matrix by deposition of hydroxyapatite crystals in the extracellular matrix. Anoctamin6/Tmem16F (Ano6) belongs to a conserved family of transmembrane proteins with chloride channel properties. In addition, Ano6 has been linked to phosphatidylserine (PS) scrambling in the plasma membrane. During skeletogenesis, Ano6 mRNA is expressed in differentiating and mature osteoblasts. Deletion of Ano6 in mice results in reduced skeleton size and skeletal deformities. Molecular analysis revealed that chondrocyte and osteoblast differentiation are not disturbed. However, mutant mice display increased regions of nonmineralized, Ibsp-expressing osteoblasts in the periosteum during embryonic development and increased areas of uncalcified osteoid postnatally. In primary Ano6−/− osteoblasts, mineralization is delayed, indicating a cell autonomous function of Ano6. Furthermore, we demonstrate that calcium-dependent PS scrambling is impaired in osteoblasts. Our study is the first to our knowledge to reveal the requirement of Ano6 in PS scrambling in osteoblasts, supporting a function of PS exposure in the deposition of hydroxyapatite. © 2013 American Society for Bone and Mineral Research

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