## Abstract Extracellular signal–regulated kinase 1/2 (ERK1/2), one of the best‐characterized members of the mitogen‐activated protein kinase (MAPK) family, mediates a range of activity from metabolism, motility, and inflammation to cell death and survival. It is phosphorylated and activated throug
Activation of the ERK pathway in osteoblastic cells, role of gremlin and BMP-2
✍ Scribed by Stefano Zanotti; Anna Smerdel-Ramoya; Lisa Stadmeyer; Ernesto Canalis
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 188 KB
- Volume
- 104
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Gremlin is a glycoprotein that binds and antagonizes the actions of bone morphogenetic proteins (BMPs) ‐2, ‐4, and ‐7. Gremlin appears to activate the extracellular regulated kinase (ERK) pathway in endothelial and tumor cells, and as a consequence to have direct cellular effects. To determine whether gremlin has direct effects in osteoblasts, independent of its BMP binding activity, we examined its effects in ST‐2 murine stromal cell lines and in primary cultures of murine calvarial osteoblasts. Gremlin did not activate Signaling mothers against decapentaplegic (Smad), and suppressed the BMP‐2 induced Smad 1/5/8 phosphorylation and the transactivation of the BMP/Smad reporter construct 12xSBE‐Oc‐pGL3, confirming its BMPs antagonizing activity. Neither gremlin nor BMP‐2 induced ERK 1/2 activation in ST‐2 cells or calvarial osteoblasts. Moreover, slight changes in culture conditions induced the phosphorylation of ERK independent from BMP or gremlin exposure. In conclusion, gremlin inhibits BMP‐2 signaling and activity, and does not have independent actions on ERK signaling in osteoblasts. Consequently, gremlin activity in osteoblasts can be attributed only to its BMP antagonizing effects. J. Cell. Biochem. 104: 1421–1426, 2008. © 2008 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
## Abstract To investigate the molecular mechanism underlying the differentiation of osteoblasts and chondroblasts, we established a clonal cell lines, RD‐C6, from __Runx2__‐deficient mouse embryos. RD‐C6 cells expressed almost undetectable levels of phenotypes related to osteoblast and chondroblas
Cisplatin induces apoptosis in a variety of cell types. However, the signaling pathway of cisplatin-induced apoptosis in renal epithelial cells is poorly understood. The present study was undertaken to determine the role of the extracellular signal-regulated kinase (ERK) in cisplatin-induced apoptos
## Abstract Oxygen‐dependent regulation of HIF‐1 activity occurs at multiple levels in vivo. The mechanisms regulating HIF‐1α protein expression have been most extensively analyzed but the ones modulating HIF‐1 transcriptional activity remain unclear. Changes in the phosphorylation and/or redox sta
## Abstract Bone metastases from prostate origin generate an osteoblastic reaction that is expressed in vitro by increased osteoblast proliferation. The urokinase‐like plasminogen activator (u‐PA) present in the media conditioned by tumoral prostatic cells acting as a ligand of the cellular membran
## Abstract The process of vascular calcification presents several features similar to osteogenesis in which fibronectin (FN) acts as a regulator of osteoblastic differentiation and the ERK signal pathway is involved. In order to find whether FN promotes the osteoblastic differentiation of vascular