## Abstract Although __Porphyromonas gingivalis__ lipopolysaccharide (PโLPS) is known to inhibit osteoblast differentiation, the exact molecular mechanisms underlying this phenomenon remain unclear. Here, we investigated the role of Notch signaling in the osteoblastic differentiation of both MC3T3E
Inhibition of Notch1 signaling by Runx2 during osteoblast differentiation
โ Scribed by Eun-Jung Ann; Hwa-Young Kim; Yun-Hee Choi; Mi-Yeon Kim; Jung-Soon Mo; Jane Jung; Ji-Hye Yoon; Su-Man Kim; Jeong-Sik Moon; Mi-Sun Seo; Ji-Ae Hong; Won-Gu Jang; Paul Shore; Toshihisa Komori; Jeong-Tae Koh; Hee-Sae Park
- Publisher
- American Society for Bone and Mineral Research
- Year
- 2011
- Tongue
- English
- Weight
- 1005 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0884-0431
- DOI
- 10.1002/jbmr.227
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Notch1 genes encode receptors for a signaling pathway that regulates cell growth and differentiation in various contexts, but the role of Notch1 signaling in osteogenesis is not well defined. Notch1 controls osteoblast differentiation by affecting Runx2, but the question arises whether normal osteoblastic differentiation can occur regardless of the presence of Notch1. In this study, we observed the downregulation of Notch1 signaling during osteoblastic differentiation. BMPRโIB/Alk6โinduced Runx2 proteins reduced Notch1 activity to a marked degree. Accumulated Runx2 suppressed Notch1 transcriptional activity by dissociating the Notch1โICโRBPโJk complex. Using deletion mutants, we also determined that the Nโterminal domain of Runx2 was crucial to the binding and inhibition of the Nโterminus of the Notch1 intracellular domain. Notably, upregulation of the Runx2 protein level paralleled reduced expression of Hes1, which is a downstream target of Notch1, during osteoblast differentiation. Collectively, our data suggest that Runx2 is an inhibitor of the Notch1 signaling pathway during normal osteoblast differentiation. ยฉ 2011 American Society for Bone and Mineral Research.
๐ SIMILAR VOLUMES
The epidermal growth factor receptor (EGFR) and its ligands regulate key processes of cell biology, such as proliferation, survival, differentiation, migration, and tumorigenesis. We previously showed that, EGFR signaling pathway is an important bone regulator and it primarily plays an anabolic role
## Abstract The Runx2/Cbfa1 transcription factor is a scaffolding protein that promotes osteoblast differentiation; however, the specific Runx2โfunctional domains required for induction of the osteogenic lineage remain to be identified. We approached this question using a TERTโimmortalized cell lin
## Abstract Tโbox (Tbx)3, a known transcriptional repressor, is a member of a family of transcription factors, which contain a highly homologous DNA binding domain known as the Tbx domain. Based on the knowledge that mutation of the Tbx3 gene results in limb malformation, Tbx3 regulates osteoblast
## Abstract The mRNAs encoding Runx2, a master osteoblast transcription factor, and its target gene Osteocalcin (OC), are commonly used as markers of osteoblast differentiation. We found that while OC mRNA levels do indeed increase during development of the osteoblast phenotype in MC3T3โE1 cultures
The runt family transcription factor (AML-3/PEBP2alphaA1/Cbfa1/RUNX2) plays a crucial role in formation of the mineralized skeleton during embryogenesis and regulates maturation of the osteoblast phenotype. Because steroid hormones and growth factors significantly influence growth and differentiatio