RRC ID 42616
著者 Hinoi E, Fujimori S, Wang L, Hojo H, Uno K, Yoneda Y.
タイトル Nrf2 negatively regulates osteoblast differentiation via interfering with Runx2-dependent transcriptional activation.
ジャーナル J Biol Chem
Abstract Nrf2 (nuclear factor E2 p45-related factor 2) is believed to be a transcription factor essential for the regulation of many detoxifying and antioxidative genes in different tissues. In the present study, we investigated the role of Nrf2 in the regulation of osteoblastic differentiation. nrf2 mRNA expression was significantly up-regulated in femur isolated from ovariectomized mice, whereas in situ hybridization analysis revealed that up-regulation of nrf2 mRNA was mainly found in osteoblasts attached on cancellous bone in femur of ovariectomized mice. Expression of Nrf2 protein was also seen in osteoblasts in neonatal mouse tibia and calvaria. In osteoblastic MC3T3-E1 cells stably transfected with nrf2 expression vector, significant inhibition was seen in the maturation-dependent increase in alkaline phosphatase activity as well as the mineralized matrix formation. Stable overexpression of nrf2 significantly impaired Runx2 (runt-related transcription factor 2)-dependent stimulation of osteocalcin promoter activity and recruitment of Runx2 on osteocalcin promoter without affecting the expression of runx2 mRNA. Coimmunoprecipitation and mammalian two-hybrid assay revealed a physical interaction between Runx2 and Nrf2, whereas cellular distribution of endogenous Runx2 was not apparently changed by nrf2 overexpression in MC3T3-E1 cells. Alternatively, Nrf2 bound to antioxidant-responsive element-like-2 sequence of osteocalcin promoter. The inhibition by nrf2 on runx2-dependent osteocalcin promoter activity was partially prevented by the introduction of reporter of deletion mutant for ARE-like-2 sequence of osteocalcin promoter. These data suggest that Nrf2 may negatively regulate cellular differentiation through inhibition of the Runx2-dependent transcriptional activity in osteoblasts.
巻・号 281(26)
ページ 18015-24
公開日 2006-6-30
DOI 10.1074/jbc.M600603200
PII S0021-9258(20)55674-3
PMID 16613847
MeSH 3T3 Cells Animals Animals, Outbred Strains COS Cells Cell Differentiation / physiology Cell Division / physiology Cell Nucleus / physiology Chlorocebus aethiops Core Binding Factor Alpha 1 Subunit / genetics Core Binding Factor Alpha 1 Subunit / metabolism* Female Gene Expression Regulation / physiology Mice NF-E2-Related Factor 2 / genetics NF-E2-Related Factor 2 / metabolism* Osteoblasts / cytology* Osteoblasts / physiology* Osteocalcin / genetics Ovariectomy Promoter Regions, Genetic / physiology RNA, Messenger / metabolism Transcriptional Activation / physiology* Transfection Up-Regulation / physiology
IF 4.238
引用数 102
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
ヒト・動物細胞 MC3T3-E1(RCB1126)