Methods for the reliable induction of heterotopic ossification in the conditional Alk2(Q207D) mouse

• Type of Material: Article
• Authors: Haichun Pan, University of Michigan; Nicole Fleming, Vanderbilt University; Charles C. Hong, Vanderbilt University; Yuji Mishina, University of Michigan; Daniel Perrien, Emory University
• Language: English
• Date: 2020-03-01
• Publisher: JMNI
• Publication Version: Final Published Version
• Copyright Statement: © 2020, International Society of Musculoskeletal and Neuronal Interactions. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International
• Title of Journal or Parent Work: Journal of musculoskeletal & neuronal interactions
• ISSN: 1108-7161
• Volume: 20
• Issue: 1
• Start Page: 149
• End Page: 159
• Grant/Funding Information: This project was supported by the Department of Veteran Affairs BLRD Career Development Award 2 (5IK2BX001634 to DSP), Department of Defense (W81XWH-11-2-0073 to YM), National Institutes of Health (1R21AR067901 and S10RR027631 to DSP, R01DE020843 to YM), the Vanderbilt Orthopaedic Institute and the Vanderbilt Department of Medicine.
• Keywords: ECTOPIC BONE-FORMATION; Fibrodysplasia Ossificans Progressiva; Neurosciences; PREVALENCE; TRAUMA; INJURY; PROGRESSIVA; Acvr1/ALK2; RECEPTOR; MODEL; BMP; NATURAL-HISTORY; Physiology; HIP; Science & Technology; Neurosciences & Neurology; Mouse Model; Life Sciences & Biomedicine; RISK-FACTORS; Muscle Injury
• Research Categories: Biology, Physiology; Biology, Neuroscience

Abstract

Objectives: Conditional ALK2Q207D-floxed (caALK2fl) mice have previously been used as a model of heterotopic ossification (HO). However, HO formation in this model can be highly variable, and it is unclear which methods reliably induce HO. Hence, these studies report validated methods for reproducibly inducing HO in caALK2fl mice. Methods: Varying doses of Adex-cre and cardiotoxin (CTX) were injected into the calf muscles of 9, 14, or 28-day-old caALK2fl/- or caALK2fl/fl mice. HO was measured by planar radiography or microCT at 14-28 days post-injury. Results: In 9-day-old caALK2fl/- or caALK2fl/fl mice, single injections of 109 PFU Adex-cre and 0.3 µg of CTX were sufficient to induce extensive HO within 14 days post-injury. In 28-day-old mice, the doses were increased to 5 x 109 PFU Adex-cre and 3.0 µg of CTX to achieve similar consistency, but at a slower rate versus younger mice. Using a crush injury, instead of CTX, also provided consistent induction of HO. Finally, the Type 1 BMPR inhibitor, DMH1, significantly reduced HO formation in 28-day-old caALK2fl/fl mice. Conclusions: These data illustrate multiple methods for reliable induction of localized HO in the caALK2fl mouse that can serve as a starting point for new laboratories utilizing this model.