Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Front Endocrinol (Lausanne). 2012 Aug 6;3:97. doi: 10.3389/fendo.2012.00097. eCollection 2012.

Glutamate signaling in bone.

Author information

  • 1Department of Physiology and Pharmacology, Bristol University, Bristol, UK.

Abstract

Mechanical loading plays a key role in the physiology of bone, allowing bone to functionally adapt to its environment, however characterization of the signaling events linking load to bone formation is incomplete. A screen for genes associated with mechanical load-induced bone formation identified the glutamate transporter GLAST, implicating the excitatory amino acid, glutamate, in the mechanoresponse. When an osteogenic load (10 N, 10 Hz) was externally applied to the rat ulna, GLAST (EAAT1) mRNA, was significantly down-regulated in osteocytes in the loaded limb. Functional components from each stage of the glutamate signaling pathway have since been identified within bone, including proteins necessary for calcium-mediated glutamate exocytosis, receptors, transporters, and signal propagation. Activation of ionotropic glutamate receptors has been shown to regulate the phenotype of osteoblasts and osteoclasts in vitro and bone mass in vivo. Furthermore, glutamatergic nerves have been identified in the vicinity of bone cells expressing glutamate receptors in vivo. However, it is not yet known how a glutamate signaling event is initiated in bone or its physiological significance. This review will examine the role of the glutamate signaling pathway in bone, with emphasis on the functions of glutamate transporters in osteoblasts.

KEYWORDS:

EAAT; bone; glutamate; osteoblast

PMID:
22888325
[PubMed]
PMCID:
PMC3412269
Free PMC Article

Images from this publication.See all images (1)Free text

FIGURE 1
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Frontiers Media SA Icon for PubMed Central
    Loading ...
    Write to the Help Desk