Intrauterine Bone Marrow Transplantation in Osteogenesis Imperfecta Mice Yields Donor Osteoclasts and Osteomacs but Not Osteoblasts

Highlights • The goal of osteogenesis imperfecta (OI) cell therapy is osteoblast replacement • In utero transplantation (IUT) of bone marrow was conducted in OI mice • Donor-derived osteoblasts were absent following bone marrow IUT • Donor-derived hematopoietic cells included osteoclasts and osteal macrophages
In this article, Millard and colleagues show that intrauterine bone marrow transplantation in the oim/oim mouse model of osteogenesis imperfecta yields hematopoietic microchimerism in the absence of donor osteopoiesis or phenotypic improvement. Bone-associated donor cells were not bone-forming osteoblasts, but osteoclasts (bone resorbing cells of the hematopoietic lineage) and osteal macrophages (bone regulatory cells of the hematopoietic lineage).