title: Identification of osteopontin in isolated rabbit osteoclasts.
abstract: Bone remodeling is a complex process coupling bone formation and resorption. Osteoblasts, the bone-forming cells, are known to produce various bone matrix proteins and cytokines; however, little is known about protein factors produced by osteoclasts or bone-resorbing cells. A method utilizing the high affinity of osteoclasts for tissue culture dishes was developed to isolate a large number of pure osteoclasts from rabbit long bones. A cDNA library was then constructed from these isolated osteoclasts, and differential cDNA screening was performed between osteoclasts and spleen cells. Two clones representing osteoclast-specific clones, named OC-1 and OC-2, were isolated. By Northern blot analysis, OC-1 was expressed in osteoclasts and in kidneys, whereas OC-2 was specific for osteoclasts. OC-1 was found to encode osteopontin from its nucleotide sequence, and therefore, osteopontin may have other functions for osteoclastic bone resorption besides osteoclast attachment to bone.
authors.affiliation: Department of Oral Anatomy, Meikai University School of Dentistry, Sakado, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tezuka
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Kamioka
authors.forename: P J
authors.initials: PJ
authors.lastname: Nijweide
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: M
authors.initials: M
authors.lastname: Ohta
authors.forename: N
authors.initials: N
authors.lastname: Kurihara
authors.forename: Y
authors.initials: Y
authors.lastname: Hakeda
authors.forename: M
authors.initials: M
authors.lastname: Kumegawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001842:Bone and Bones / Q000502:physiology; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D010010:Osteoclasts / Q000166:cytology / Q000502:physiology*; D053495:Osteopontin; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D011817:Rabbits; D012689:Sequence Homology, Nucleic Acid; D012795:Sialoglycoproteins / Q000032:analysis / Q000235:genetics*
chemical_list: D015342:DNA Probes; D012333:RNA, Messenger; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin; D011061:Poly A; D012313:RNA; D004247:DNA