Endothelin-1 regulates rat bone sialoprotein gene transcription.
Endothelin-1 (ET-1) was originally discovered as a vasoconstrictor protein excreted by vascular endothelial cells. Recently, tumor-produced ET-1 has been considered to stimulate osteoblasts to form new bone, and to be an important mediator of osteoblastic bone metastasis. ET-1 has high affinity for two different membrane receptors, ET(A)R and ET(B)R, which are expressed by many types of cells including osteoblasts. Bone sialoprotein (BSP) is a phosphorylated and sulfated glycoprotein associated with mineralized connective tissues. To investigate the effects of ET-1 on BSP transcription, we used rat osteoblast-like ROS17/2.8 cells. Levels of BSP and osteopontin mRNA were increased at 12 h after treatment with ET-1 (10 ng/ml), and ET-1 at the same concentration induced luciferase activity of a -116 to +60 BSP promoter construct at 6 h. Transcriptional activity of -84BSPLUC, which contains the cAMP response element (CRE), was increased by ET-1. Furthermore, at 6 h, ET-1 (10 ng/ml) increased the binding of nuclear protein to CRE, the FGF2 response element (FRE) and the homeodomain protein-binding site (HOX). Antibodies against CREB1, JunD and Fra2 disrupted the formation of CRE-protein complexes, while antibodies against Runx2 and Dlx5 reduced the formation of FRE- and HOX-protein complexes. These findings indicate that ET-1 increases BSP transcription via the CRE, FRE and HOX sites in the rat BSP gene promoter.
Li
Xinyue
X
Department of Periodontology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Wang
Zhitao
Z
Yang
Li
L
Li
Zhengyang
Z
Ogata
Yorimasa
Y
D000818:Animals; D045744:Cell Line, Tumor; D050659:Core Binding Factor Alpha 1 Subunit / Q000037:antagonists & inhibitors; D000242:Cyclic AMP / Q000235:genetics; D017362:Cyclic AMP Response Element-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics; D019332:Endothelin-1 / Q000235:genetics*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics; D051921:Fos-Related Antigen-2 / Q000037:antagonists & inhibitors; D005786:Gene Expression Regulation / Q000235:genetics; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D058574:Integrin-Binding Sialoprotein; D010006:Osteoblasts / Q000378:metabolism; D053495:Osteopontin / Q000032:analysis / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020218:Response Elements / Q000235:genetics; D012795:Sialoglycoproteins / Q000032:analysis / Q000235:genetics*; D013997:Time Factors; D014157:Transcription Factors / Q000037:antagonists & inhibitors; D014158:Transcription, Genetic / Q000235:genetics*
C508137:Creb1 protein, rat; D050659:Core Binding Factor Alpha 1 Subunit; D017362:Cyclic AMP Response Element-Binding Protein; C088334:Distal-less homeobox proteins; D019332:Endothelin-1; D051921:Fos-Related Antigen-2; C497874:Fosl2 protein, rat; D018398:Homeodomain Proteins; C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; C549531:JunD protein, rat; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; C493717:Runx2 protein, rat; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D014157:Transcription Factors; D016222:Fibroblast Growth Factor 2; D053495:Osteopontin; D000242:Cyclic AMP