Abstract
Individuals with neurofibromatosis type-1 (NF1) can manifest focal skeletal dysplasias that remain extremely difficult to treat. NF1 is caused by mutations in the NF1 gene, which encodes the RAS GTPase-activating protein neurofibromin. We report here that ablation of Nf1 in bone-forming cells leads to supraphysiologic accumulation of pyrophosphate (PP i), a strong inhibitor of hydroxyapatite formation, and that a chronic extracellular signal-regulated kinase (ERK)-dependent increase in expression of genes promoting PP i synthesis and extracellular transport, namely Enpp1 and Ank, causes this phenotype. Nf1 ablation also prevents bone morphogenic protein-2-induced osteoprogenitor differentiation and, consequently, expression of alkaline phosphatase and PP i breakdown, further contributing to PP i accumulation. The short stature and impaired bone mineralization and strength in mice lacking Nf1 in osteochondroprogenitors or osteoblasts can be corrected by asfotase- α enzyme therapy aimed at reducing PP i concentration. These results establish neurofibromin as an essential regulator of bone mineralization. They also suggest that altered PP i homeostasis contributes to the skeletal dysplasias associated with NF1 and that some of the NF1 skeletal conditions could be prevented pharmacologically.
Original language | English |
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Pages (from-to) | 904-910 |
Number of pages | 7 |
Journal | Nature Medicine |
Volume | 20 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2014 |
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Medicine(all)