TY - JOUR
T1 - Fibroblast growth factor 2 and cyclic AMP synergistically regulate bone sialoprotein gene expression
AU - Shimizu, Emi
AU - Nakayama, Youhei
AU - Nakajima, Yu
AU - Kato, Naoko
AU - Takai, Hideki
AU - Kim, Dong Soon
AU - Arai, Masato
AU - Saito, Ryoichiro
AU - Sodek, Jaro
AU - Ogata, Yorimasa
N1 - Funding Information:
This work was supported by the following grants: Grants-in-Aid for Scientific Research (A: 17209065, C: 16592081) from Japan Society for the Promotion of Science (JSPS); a Nihon University Research Grant (Multidisciplinary Research Grant for 2003 and Assistants and Young Researchers for 2004); a Canadian Institutes of Health Research (CIHR) grant, MOP-37785; and a Grant from the Ministry of Education, Culture, Sports, Science and Technology to promote 2001-Multidisciplinary Research Project (in 2001–2005).
PY - 2006/7
Y1 - 2006/7
N2 - Bone sialoprotein (BSP) is a noncollagenous protein of the mineralized bone extracellular matrix. We here report that FGF2 and cAMP act synergistically to stimulate BSP gene expression. Treatment of ROS 17/2.8 cells with either 10 ng/ml FGF2 or 1 μM FSK for 6 h resulted in 5.4- and 8.2-fold increases, respectively, in the levels of BSP mRNA. However, in the presence of both FGF2 and forskolin (FGF/FSK), BSP mRNA levels were increased synergistically by 20.4-fold. Using a luciferase reporter construct, encompassing BSP promoter nucleotides -116 to +60, transcription was also increased synergistically by 15.0-fold with FGF/FSK, compared to stimulations of 2.6- and 5.3-fold, respectively, for FGF2 and FSK alone. Transcriptional stimulation by FGF/FSK abrogated in constructs included 2 bp mutations in the inverted CCAAT, CRE, FRE and Pit-1 elements. Whereas the FRE-protein complex was increased by FGF2 and FGF/FSK, the Pit-1-protein complex was decreased by FSK and FGF/FSK. Notably, transcriptional activity induced by FGF/FSK was blocked by protein kinase A, tyrosine kinase and MEK inhibitors. These studies indicate that the combinatorial effects of FGF and FSK act through PKA, tyrosine kinase and MAP-kinase-dependent pathways, which target the inverted CCAAT, CRE, FRE and Pit-1 elements in the BSP gene to synergistically increase BSP expression.
AB - Bone sialoprotein (BSP) is a noncollagenous protein of the mineralized bone extracellular matrix. We here report that FGF2 and cAMP act synergistically to stimulate BSP gene expression. Treatment of ROS 17/2.8 cells with either 10 ng/ml FGF2 or 1 μM FSK for 6 h resulted in 5.4- and 8.2-fold increases, respectively, in the levels of BSP mRNA. However, in the presence of both FGF2 and forskolin (FGF/FSK), BSP mRNA levels were increased synergistically by 20.4-fold. Using a luciferase reporter construct, encompassing BSP promoter nucleotides -116 to +60, transcription was also increased synergistically by 15.0-fold with FGF/FSK, compared to stimulations of 2.6- and 5.3-fold, respectively, for FGF2 and FSK alone. Transcriptional stimulation by FGF/FSK abrogated in constructs included 2 bp mutations in the inverted CCAAT, CRE, FRE and Pit-1 elements. Whereas the FRE-protein complex was increased by FGF2 and FGF/FSK, the Pit-1-protein complex was decreased by FSK and FGF/FSK. Notably, transcriptional activity induced by FGF/FSK was blocked by protein kinase A, tyrosine kinase and MEK inhibitors. These studies indicate that the combinatorial effects of FGF and FSK act through PKA, tyrosine kinase and MAP-kinase-dependent pathways, which target the inverted CCAAT, CRE, FRE and Pit-1 elements in the BSP gene to synergistically increase BSP expression.
KW - Basic fibroblast growth factor
KW - Bone sialoprotein
KW - Gene expression
KW - cAMP
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U2 - 10.1016/j.bone.2005.12.011
DO - 10.1016/j.bone.2005.12.011
M3 - Article
C2 - 16466682
AN - SCOPUS:33646870845
SN - 8756-3282
VL - 39
SP - 42
EP - 52
JO - Bone
JF - Bone
IS - 1
ER -