Identification and characterization of high glucose and glucosamine responsive element in the rat osteopontin promoter.
We have previously reported that high glucose stimulates osteopontin (OPN) expression via a protein kinase C-dependent pathway and a hexosamine pathway in cultured rat aortic smooth muscle cells (SMCs) [Biochem. Biophys. Res. Commun. 258 (1999) 722.]. In the present study, we carried out functional OPN promoter assays using the luciferase expression vector system in cultured rat aortic SMCs to determine a high glucose/glucosamine responsive element. An extensive deletion analysis of the 5'-flanking region of the rat OPN gene revealed that an element involved in high glucose and glucosamine responses was present within a region between -112 and -62 bp of the OPN promoter. This region is highly conserved in the rat, mouse, and human promoters and contains a number of consensus regions, including an E-box and a GC-rich region. Mutation of the E-box or the GC-rich region resulted in a significant loss of both high glucose and glucosamine responses. These results suggest that two cis-acting elements, the E-box and the GC-rich region, are involved at least partly in high glucose/glucosamine-stimulated transcription of the rat OPN gene.
Asaumi
Sunao
S
Department of Clinical Cell Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Japan.
Takemoto
Minoru
M
Yokote
Koutaro
K
Ridall
Amy L
AL
Butler
William T
WT
Fujimoto
Masaki
M
Kobayashi
Kazuki
K
Kawamura
Harukiyo
H
Take
Ayako
A
Saito
Yasushi
Y
Mori
Seijiro
S
D000818:Animals; D001011:Aorta; D001483:Base Sequence; D002478:Cells, Cultured; D017124:Conserved Sequence; D017353:Gene Deletion; D015870:Gene Expression; D005944:Glucosamine / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D009131:Muscle, Smooth, Vascular; D016296:Mutagenesis; D053495:Osteopontin; D011401:Promoter Regions, Genetic / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D020218:Response Elements / Q000187:drug effects*; D012795:Sialoglycoproteins / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; C506897:Spp1 protein, rat; D053495:Osteopontin; D005947:Glucose; D005944:Glucosamine