Phosphatase inhibition by LB-100 enhances BMN-111 stimulation of bone growth.

Abstract

Activating mutations in fibroblast growth factor receptor 3 (FGFR3) and inactivating mutations in the natriuretic peptide receptor 2 (NPR2) guanylyl cyclase both result in decreased production of cyclic GMP in chondrocytes and severe short stature, causing achondroplasia (ACH) and acromesomelic dysplasia, type Maroteaux, respectively. Previously, we showed that an NPR2 agonist BMN-111 (vosoritide) increases bone growth in mice mimicking ACH (Fgfr3Y367C/+). Here, because FGFR3 signaling decreases NPR2 activity by dephosphorylating the NPR2 protein, we tested whether a phosphatase inhibitor (LB-100) could enhance BMN-111-stimulated bone growth in ACH. Measurements of cGMP production in chondrocytes of living tibias, and of NPR2 phosphorylation in primary chondrocytes, showed that LB-100 counteracted FGF-induced dephosphorylation and inactivation of NPR2. In ex vivo experiments with Fgfr3Y367C/+ mice, the combination of BMN-111 and LB-100 increased bone length and cartilage area, restored chondrocyte terminal differentiation, and increased the proliferative growth plate area, more than BMN-111 alone. The combination treatment also reduced the abnormal elevation of MAP kinase activity in the growth plate of Fgfr3Y367C/+ mice and improved the skull base anomalies. Our results provide a proof of concept that a phosphatase inhibitor could be used together with an NPR2 agonist to enhance cGMP production as a therapy for ACH.

• Authors: Leia C Shuhaibar, Nabil Kaci, Jeremy R Egbert, Thibault Horville, Léa Loisay, Giulia Vigone, Tracy F Uliasz, Emilie Dambroise, Mark R Swingle, Richard E Honkanen, Martin Biosse Duplan, Laurinda A Jaffe, Laurence Legeai-Mallet
• Journal: JCI insight (JCI Insight) Vol. 6 Issue 9 (05 10 2021) ISSN: 2379-3708 [Electronic] United States
• PMID: 33986191 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Enzyme Inhibitors
• LB100
• Piperazines
• Natriuretic Peptide, C-Type
• vosoritide
• Fgfr3 protein, mouse
• Receptor, Fibroblast Growth Factor, Type 3
• Phosphoric Monoester Hydrolases
• Receptors, Atrial Natriuretic Factor
• atrial natriuretic factor receptor B

Topics

• Achondroplasia (genetics)
• Animals
• Bone Development (drug effects)
• Bone Diseases, Developmental (genetics)
• Cartilage (drug effects, growth & development)
• Cell Differentiation (drug effects)
• Chondrocytes (drug effects)
• Drug Synergism
• Enzyme Inhibitors (pharmacology)
• Growth Plate (drug effects, growth & development)
• Mice
• Natriuretic Peptide, C-Type (analogs & derivatives, pharmacology)
• Organ Size
• Phosphoric Monoester Hydrolases (antagonists & inhibitors)
• Phosphorylation
• Piperazines (pharmacology)
• Primary Cell Culture
• Receptor, Fibroblast Growth Factor, Type 3 (genetics)
• Receptors, Atrial Natriuretic Factor (agonists, genetics)
• Tibia (drug effects, growth & development)