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Heterotopic ossification in mice overexpressing Bmp2 in Tie2+ lineages.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Del Toro, Raquel 
Gómez-Apiñániz, Paula 
Papoutsi, Tania 

Abstract

Bone morphogenetic protein (Bmp) signaling is critical for organismal development and homeostasis. To elucidate Bmp2 function in the vascular/hematopoietic lineages we generated a new transgenic mouse line in which ectopic Bmp2 expression is controlled by the Tie2 promoter. Tie2CRE/+;Bmp2tg/tg mice develop aortic valve dysfunction postnatally, accompanied by pre-calcific lesion formation in valve leaflets. Remarkably, Tie2CRE/+;Bmp2tg/tg mice develop extensive soft tissue bone formation typical of acquired forms of heterotopic ossification (HO) and genetic bone disorders, such as Fibrodysplasia Ossificans Progressiva (FOP). Ectopic ossification in Tie2CRE/+;Bmp2tg/tg transgenic animals is accompanied by increased bone marrow hematopoietic, fibroblast and osteoblast precursors and circulating pro-inflammatory cells. Transplanting wild-type bone marrow hematopoietic stem cells into lethally irradiated Tie2CRE/+;Bmp2tg/tg mice significantly delays HO onset but does not prevent it. Moreover, transplanting Bmp2-transgenic bone marrow into wild-type recipients does not result in HO, but hematopoietic progenitors contribute to inflammation and ectopic bone marrow colonization rather than to endochondral ossification. Conversely, aberrant Bmp2 signaling activity is associated with fibroblast accumulation, skeletal muscle fiber damage, and expansion of a Tie2+ fibro-adipogenic precursor cell population, suggesting that ectopic bone derives from a skeletal muscle resident osteoprogenitor cell origin. Thus, Tie2CRE/+;Bmp2tg/tg mice recapitulate HO pathophysiology, and might represent a useful model to investigate therapies seeking to mitigate disorders associated with aberrant extra-skeletal bone formation.

Description

Keywords

Animals, Aortic Valve, Bone Marrow Transplantation, Bone Morphogenetic Protein 2, Calcinosis, Cell Lineage, Chondrogenesis, Endothelial Cells, Hematopoiesis, Hematopoietic Stem Cells, Kaplan-Meier Estimate, Mice, Inbred C57BL, Mice, Transgenic, Muscle Cells, Ossification, Heterotopic, Osteogenesis, Receptor, TIE-2, Tomography, X-Ray Computed, Mice

Journal Title

Cell Death Dis

Conference Name

Journal ISSN

2041-4889
2041-4889

Volume Title

12

Publisher

Springer Science and Business Media LLC
Sponsorship
Medical Research Council (MC_PC_17230)
MRC (MR/V005421/1)