Parathyroid hormone induces interleukin-6 gene expression in bone stromal cells of young rats.
To test the hypothesis that parathyroid hormone (PTH) regulates interleukin-6 (IL-6) expression locally in bone, the expression of IL-6 mRNA was examined by in situ hybridization after a subcutaneous injection of human PTH [1-84] (225 microg/kg) in 4-week old rats. Whereas IL-6 mRNA was not detected at the basal status, it was transiently detected in a subpopulation of stromal cells in the intertrabecular region of the metaphyses from 1/2 to 1 hr after PTH injection. Contrastingly, IL-6 transcripts were not detected in other cell populations at any time points examined. Since IL-6 is a known activator of osteoclasts, these results are consistent with the hypothesis that PTH stimulates the local IL-6 synthesis in stromal cells to indirectly activate osteoclasts.
Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Fruit Street, Boston, MA 02114, USA.
Shuichi
S
Chiba
Masako
M
Un-No
Robert M
RM
Neer
Kosuke
K
Okada
Gino V
GV
Serge
Kaechoong
K
Lee
D000818:Animals; D001862:Bone Resorption; D001842:Bone and Bones / Q000166:cytology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017154:Stromal Cells / Q000187:drug effects* / Q000378:metabolism
D015850:Interleukin-6; D010281:Parathyroid Hormone; D012333:RNA, Messenger