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

  • Akihide Nampei
  • Jun Hashimoto
  • Kenji Hayashida
  • Hideki Tsuboi
  • Kenrin Shi
  • Isamu Tsuji
  • Hideaki Miyashita
  • Takao Yamada
  • Naomichi Matsukawa
  • Masayuki Matsumoto
  • Shigeto Morimoto
  • Toshio Ogihara
  • Takahiro Ochi
  • Hideki Yoshikawa
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

Authors and Affiliations

  • Akihide Nampei
    • 1
  • Jun Hashimoto
    • 1
  • Kenji Hayashida
    • 1
  • Hideki Tsuboi
    • 1
  • Kenrin Shi
    • 1
  • Isamu Tsuji
    • 4
  • Hideaki Miyashita
    • 4
  • Takao Yamada
    • 4
  • Naomichi Matsukawa
    • 2
  • Masayuki Matsumoto
    • 3
  • Shigeto Morimoto
    • 3
  • Toshio Ogihara
    • 2
  • Takahiro Ochi
    • 1
  • Hideki Yoshikawa
    • 1
  1. 1.Department of OrthopaedicsOsaka University Graduate School of MedicineSuitaJapan
  2. 2.Department of Geriatric MedicineOsaka University Graduate School of MedicineOsakaJapan
  3. 3.Department of Geriatric MedicineKanazawa Medical UniversityKanazawaJapan
  4. 4.Pharmaceutical Research DivisionTakeda Chemical IndustriesOsakaJapan