Journal of Bone and Mineral Metabolism

, Volume 22, Issue 3, pp 176–184

Matrix extracellular phosphoglycoprotein (MEPE) is highly expressed in osteocytes in human bone

Authors

  • Akihide Nampei
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
  • Kenji Hayashida
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
  • Hideki Tsuboi
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
  • Kenrin Shi
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
  • Isamu Tsuji
    • Pharmaceutical Research DivisionTakeda Chemical Industries
  • Hideaki Miyashita
    • Pharmaceutical Research DivisionTakeda Chemical Industries
  • Takao Yamada
    • Pharmaceutical Research DivisionTakeda Chemical Industries
  • Naomichi Matsukawa
    • Department of Geriatric MedicineOsaka University Graduate School of Medicine
  • Masayuki Matsumoto
    • Department of Geriatric MedicineKanazawa Medical University
  • Shigeto Morimoto
    • Department of Geriatric MedicineKanazawa Medical University
  • Toshio Ogihara
    • Department of Geriatric MedicineOsaka University Graduate School of Medicine
  • Takahiro Ochi
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
  • Hideki Yoshikawa
    • Department of OrthopaedicsOsaka University Graduate School of Medicine
Original articles

DOI: 10.1007/s00774-003-0468-9

Cite this article as:
Nampei, A., Hashimoto, J., Hayashida, K. et al. J Bone Miner Metab (2004) 22: 176. doi:10.1007/s00774-003-0468-9

Abstract

The matrix extracellular phosphoglycoprotein (MEPE) gene is highly expressed in tumors that cause oncogenic hypophosphatemic osteomalacia (OHO). MEPE is also known as one of the bone-tooth matrix proteins and is associated with bone mineralization. We developed a rabbit polyclonal antibody directed against recombinant human MEPE (rhMEPE) after cloning its cDNA from the cDNA library of a nasal tumor tissue causing OHO. Using this antibody, we analyzed the distribution of MEPE in human bones by immunohistochemistry. In bone specimens from normal subjects, MEPE was predominantly expressed by osteocytes and not by osteoblasts. In bone specimens from patients with osteomalacia, however, MEPE was focally expressed by deeply located osteocytes. We also compared the MEPE positivity of osteocytes in mineralized bone and non-mineralized osteoid obtained from patients with osteomalacia and osteoporosis. Among osteomalacia patients, MEPE positivity was seen in 87.5 ± 8.6% of the osteocytes from mineralized bone compared with 7.8 ± 6.4% of those from osteoid. Among osteoporosis patients, MEPE positivity was found in 95.3 ± 0.5% of the osteocytes from mineralized bone compared with 4.9 ± 5.7% of those from osteoid. MEPE was mainly expressed by osteocytes embedded in the matrix of mineralized bone from patients with osteomalacia or osteoporosis. Our data provide the first histological evidence that MEPE is predominantly expressed by osteocytes in human bone, with significant expression by osteocytes within mineralized bone.

Key words

MEPEosteocyteimmunohistochemistrymineralizationhuman

Copyright information

© Springer-Verlag Tokyo 2004