VEGF Secretion Drives Bone Formation in Classical MAP2K1+ Melorheostosis

© 2023 American Society for Bone and Mineral Research (ASBMR)..

Patients with classical melorheostosis exhibit exuberant bone overgrowth in the appendicular skeleton, resulting in pain and deformity with no known treatment. Most patients have somatic, mosaic mutations in MAP2K1 (encoding the MEK1 protein) in osteoblasts and overlying skin. As with most rare bone diseases, lack of affected tissue has limited the opportunity to understand how the mutation results in excess bone formation. The aim of this study was to create a cellular model to study melorheostosis. We obtained patient skin cells bearing the MAP2K1 mutation (affected cells), and along with isogenic control normal fibroblasts reprogrammed them using the Sendai virus method into induced pluripotent stem cells (iPSCs). Pluripotency was validated by marker staining and embryoid body formation. iPSCs were then differentiated to mesenchymal stem cells (iMSCs) and validated by flow cytometry. We confirmed retention of the MAP2K1 mutation in iMSCs with polymerase chain reaction (PCR) and confirmed elevated MEK1 activity by immunofluorescence staining. Mutation-bearing iMSCs showed significantly elevated vascular endothelial growth factor (VEGF) secretion, proliferation and collagen I and IV secretion. iMSCs were then differentiated into osteoblasts, which showed increased mineralization at 21 days and increased VEGF secretion at 14 and 21 days of differentiation. Administration of VEGF to unaffected iMSCs during osteogenic differentiation was sufficient to increase mineralization. Blockade of VEGF by bevacizumab reduced mineralization in iMSC-derived affected osteoblasts and in affected primary patient-derived osteoblasts. These data indicate that patient-derived induced pluripotent stem cells recreate the elevated MEK1 activity, increased mineralization, and increased proliferation seen in melorheostosis patients. The increased bone formation is driven, in part, by abundant VEGF secretion. Modifying the activity of VEGF (a known stimulator of osteoblastogenesis) represents a promising treatment pathway to explore. iPSCs may have wide applications to other rare bone diseases. © 2023 American Society for Bone and Mineral Research (ASBMR).

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:38

Enthalten in:

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research - 38(2023), 12 vom: 21. Dez., Seite 1834-1845

Sprache:

Englisch

Beteiligte Personen:

Allbritton-King, Jules D [VerfasserIn]
Maity, Jyotirindra [VerfasserIn]
Patel, Amit [VerfasserIn]
Colbert, Robert A [VerfasserIn]
Navid, Fatemeh [VerfasserIn]
Bhattacharyya, Timothy [VerfasserIn]

Links:

Volltext

Themen:

EC 2.7.12.2
IPSCs
Journal Article
MAP Kinase Kinase 1
MAP2K1 protein, human
MELORHEOSTOSIS
MINERALIZATION
OSTEOBLASTS
Research Support, N.I.H., Intramural
VEGF
VEGFA protein, human
Vascular Endothelial Growth Factor A

Anmerkungen:

Date Completed 06.01.2024

Date Revised 11.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/jbmr.4915

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM362339473