Profiling Insulin Like Factor 3 (INSL3) Signaling in Human Osteoblasts
Abstract
Background: Young men with mutations in the gene for the INSL3 receptor (Relaxin family peptide 2, RXFP2) are at risk of reduced bone mass and osteoporosis. Consistent with the human phenotype, bone analyses of Rxfp2â /â mice showed decreased bone volume, alterations of the trabecular bone, reduced mineralizing surface, bone formation, and osteoclast surface. The aim of this study was to elucidate the INSL3/RXFP2 signaling pathways and targets in human osteoblasts.Methodology/Principal Findings: Alkaline phosphatase (ALP) production, protein phosphorylation, intracellular calcium, gene expression, and mineralization studies have been performed. INSL3 induced a significant increase in ALP production, and Western blot and ELISA analyses of multiple intracellular signaling pathway molecules and their phosphorylation status revealed that the MAPK was the major pathway influenced by INSL3, whereas it does not modify intracellular calcium concentration. Quantitative Real Time PCR and Western blotting showed that INSL3 regulates the expression of different osteoblast markers. Alizarin red-S staining confirmed that INSL3-stimulated osteoblasts are fully differentiated and able to mineralize the extracellular matrix.
Conclusions/Significance: Together with previous findings, this study demonstrates that the INSL3/RXFP2 system is involved in bone metabolism by acting on the MAPK cascade and stimulating transcription of important genes of osteoblast maturation/differentiation and osteoclastogenesis.
Citation
PLoS One. 2011 Dec 28; 6(12):e29733ae974a485f413a2113503eed53cd6c53
10.1371/journal.pone.0029733
Scopus Count
Related articles
- Mutations in the insulin-like factor 3 receptor are associated with osteoporosis.
- Authors: Ferlin A, Pepe A, Gianesello L, Garolla A, Feng S, Giannini S, Zaccolo M, Facciolli A, Morello R, Agoulnik AI, Foresta C
- Issue date: 2008 May
- RELAXIN enhances differentiation and matrix mineralization through Relaxin/insulin-like family peptide receptor 2 (Rxfp2) in MC3T3-E1 cells in vitro.
- Authors: Duarte C, Kobayashi Y, Kawamoto T, Moriyama K
- Issue date: 2014 Aug
- New roles for INSL3 in adults.
- Authors: Ferlin A, Pepe A, Gianesello L, Garolla A, Feng S, Facciolli A, Morello R, Agoulnik AI, Foresta C
- Issue date: 2009 Apr
- Insulin-like factor 3 promotes wound healing at the ocular surface.
- Authors: Hampel U, Klonisch T, Sel S, Schulze U, Garreis F, Seitmann H, Zouboulis CC, Paulsen FP
- Issue date: 2013 Jun
- Abnormal insulin-like growth factor 1 signaling in human osteoarthritic subchondral bone osteoblasts.
- Authors: Massicotte F, Aubry I, Martel-Pelletier J, Pelletier JP, Fernandes J, Lajeunesse D
- Issue date: 2006