Regulation of the mGluR5, EAAT1 and GS expression by glucocorticoids in MG-63 osteoblast-like osteosarcoma cells.
BACKGROUND
Growth factors, cytokines, sex steroid hormones and glucocorticoids have differential and complex effects on skeletal metabolism. Recently, the presence of the glutamatergic (Glu) system in bone cells has provided new evidence for its possible role in bone physiology. Consequently, we have investigated the regulation of certain components of the Glu system by glucocorticoids in MG-63 osteoblast-like osteosarcoma cells, in vitro.


METHODS
We characterized the effects of dexamethasone on the expression of the mGluR5, EAAT1 and GS, at mRNA and protein level, using relative quantitative RTPCR and Western blot analysis, respectively.


RESULTS
We confirmed the induction of GS expression by dexamethasone published previously. In addition, we documented for the first time the expression of the mGluR5 and EAAT1 in MG-63 cells, as well as the ability of dexamethasone to upregulate the expression of the mGluR5 and EAAT1 in the MG-63 cells.


CONCLUSIONS
Components of the glutamatergic system may play a role in bone pathophysiology.
Kalariti
N
N
Department of Experimental Physiology, Medical School, University of Athens, Goudi-Athens, Greece.
Lembessis
P
P
Papageorgiou
E
E
Pissimissis
N
N
Koutsilieris
M
M
D001846:Bone Development / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D003907:Dexamethasone / Q000378:metabolism / Q000494:pharmacology; D027341:Excitatory Amino Acid Transporter 1 / Q000235:genetics / Q000378:metabolism*; D005938:Glucocorticoids / Q000378:metabolism* / Q000494:pharmacology; D005974:Glutamate-Ammonia Ligase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D012516:Osteosarcoma; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D027341:Excitatory Amino Acid Transporter 1; C578935:GRM5 protein, human; D005938:Glucocorticoids; D012333:RNA, Messenger; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; C493394:SLC1A3 protein, human; D018698:Glutamic Acid; D003907:Dexamethasone; D005974:Glutamate-Ammonia Ligase