Expression of an N-Methyl-D-Aspartate-Type Receptor by Human and Rat Osteoblasts and Osteoclasts Suggests a Novel Glutamate Signaling Pathway in Bone

• Published in: Bone (New York, N.Y.) Vol. 22; no. 6; pp. 645 - 649
• Main Authors: Patton, A.J, Genever, P.G, Birch, M.A, Suva, L.J, Skerry, T.M
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.1998; Elsevier Science
• Subjects: Amino Acid Transport System X-AG; Animals; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Base Composition; Biological and medical sciences; Biological Transport; Bone formation; Bone resorption; Disks Large Homolog 4 Protein; Fundamental and applied biological sciences. Psychology; Glutamate receptor; Glutamic Acid - genetics; Glutamic Acid - metabolism; Guanylate Kinases; Humans; Immunohistochemistry; In Situ Hybridization; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Mice; Nerve Tissue Proteins - biosynthesis; Nerve Tissue Proteins - genetics; NMDA; Osteoblasts - metabolism; Osteoclasts - metabolism; Osteoporosis; Polymerase Chain Reaction; Rats; Receptors, N-Methyl-D-Aspartate - biosynthesis; Receptors, N-Methyl-D-Aspartate - genetics; RNA, Messenger - isolation & purification; RNA, Messenger - metabolism; Signal Transduction - genetics; Skeleton and joints; Vertebrates: osteoarticular system, musculoskeletal system; Bone resorption; NMDA; Osteoporosis; Glutamate receptor; Bone formation; Human; Immunohistochemistry; Rat; In situ; Rodentia; Exploration; Osteoclast; Hybridization; Bone remodeling; Glutamate; Osteoarticular system; Pathology; Signal transduction; Vertebrata; Histopathology; Mammalia; Bone mass; Messenger RNA; Animal; Osteoblast; Bone; Biological receptor
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/S8756-3282(98)00061-1

Signaling between the various types of cells found in bone is responsible for controlling the activity of osteoblasts and osteoclasts, and therefore the regulation of bone mass. Our identification of a neuronal glutamate transporter in osteoblasts and osteocytes suggests the possibility that bone cells may use the excitatory amino acid glutamate as a signaling molecule. In these studies we report the expression of different subtypes of glutamate receptors in osteoblasts and osteoclasts in vitro and in vivo. We have identified expression in human and rat bone cells of N-methyl-D-aspartate receptor-1 (NMDAR-1) and 2D subunits and PSD-95, the NMDA receptor clustering protein associated with signaling in the central nervous system. In situ hybridization and immunohistochemistry localized NMDAR-1 expression to osteoblasts and osteoclasts in human tissue sections. These findings strengthen the suggestion that glutamate is involved in signaling between bone cells.