title: Monohydroxylated polycyclic aromatic hydrocarbons inhibit both osteoclastic and osteoblastic activities in teleost scales.
abstract: OBJECTIVE
  We previously demonstrated that monohydroxylated polycyclic aromatic hydrocarbons (OHPAHs) bound to a human estrogen receptor (ER) by a yeast two-hybrid assay, but polycyclic aromatic hydrocarbons did not have a binding activity. Therefore, the direct effect of 3-hydroxybenz[a]anthracene (3-OHBaA) and 4-hydroxybenz[a]anthracene (4-OHBaA) on osteoclasts and osteoblasts in teleosts was examined. As a negative control, 1-hydroxypyrene (1-OHPy), which has no binding activity to human ER, was used.
  
  
  METHODS
  The effect of OHPAHs on osteoclasts and osteoblasts was examined by an assay system using teleost scale as each marker: tartrate-resistant acid phosphatase for osteoclasts and alkaline phosphatase for osteoblasts. Changes in cathepsin K (an osteoclastic marker) and insulin-like growth factor-I (IGF-I) (an osteoblastic marker) mRNA expressions in 4-OHBaA-treated goldfish scales were examined by using a reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  In both goldfish (a freshwater teleost) and wrasse (a marine teleost), the osteoclastic activity in the scales was significantly suppressed by 3-OHBaA and 4-OHBaA, although 1-OHPy did not affect the osteoclastic activity. In reference to osteoblasts, the osteoblastic activity decreased with both 3-OHBaA and 4-OHBaA and did not change with the 1-OHPy treatment. However, 17beta-estradiol (E(2)) significantly increased both the osteoclastic and osteoblastic activities in the scales of both goldfish and wrasse. The mRNA expressions of both cathepsin K and IGF-I decreased in the 4-OHBaA-treated scales but increased in the E(2)-treated scales.
  
  
  CONCLUSIONS
  The current data are the first to demonstrate that 3-OHBaA and 4-OHBaA inhibited both osteoclasts and osteoblasts and disrupted the bone metabolism in teleosts.
authors.affiliation: Noto Marine Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Noto-cho, Ishikawa 927-0553, Japan. nobuo@kenroku.kanazawa-u.ac.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Suzuki
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Hayakawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kameda
authors.forename: Akira
authors.initials: A
authors.lastname: Triba
authors.forename: Ning
authors.initials: N
authors.lastname: Tang
authors.forename: Makoto J
authors.initials: MJ
authors.lastname: Tabata
authors.forename: Koji
authors.initials: K
authors.lastname: Takada
authors.forename: Shigehito
authors.initials: S
authors.lastname: Wada
authors.forename: Katsunori
authors.initials: K
authors.lastname: Omori
authors.forename: Ajai K
authors.initials: AK
authors.lastname: Srivastav
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mishima
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Hattori
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D056657:Cathepsin K; D002403:Cathepsins / Q000378:metabolism; D005399:Fishes / Q000254:growth & development* / Q000378:metabolism; D006054:Goldfish / Q000254:growth & development / Q000378:metabolism; D006900:Hydroxylation; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D034582:Integumentary System / Q000254:growth & development; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D007334:Insulin-Like Growth Factor I; D002403:Cathepsins; C534130:CTSK protein, human; D056657:Cathepsin K