Osteochondroprogenitor cell

Abstract: The requirement of Runx2 (Cbfal/AML3), a runt homology domain transcription factor essential for bone formation and osteoblast differentiation, is well established. Although Runx2 is expressed in the developing embryo prior to ossification, yet in the absence of Runx2 initial formation of the skeleton is normal, suggesting a potential redundancy in function of Runx family members. Here we addressed expression of the hematopoietic family member Runx1 (AML1/Cbfa2) in relation to skeletal development using a LacZ knock-in mouse model (Runx1(lz/+)). The resulting fusion protein reflects Runx1 promoter activity in its native context. Our studies show that Runx1 is expressed by prechondrocytic tissue forming the cartilaginous anlagen in the embryo, resting zone chondrocytes, suture lines of the calvarium, and in periosteal and perichondral membranes of all bone. Runx1 continues to be expressed in these tissues in adult mice, but is absent in mature cartilage or mineralized bone. However, hyaline cartilage outside the bone environment (trachea, xiphoid tissues), and epithelium of many soft tissues (trachea, thyroid, lung, skin) also express Runx1. The robust expression of Runx1 in vivo in chondroblasts at sites of cartilage growth and in osteoblasts at sites of new bone formation, suggests that Runx1 expression may be related to osteochondroprogenitor cell differentiation. This observation is further supported by high expression of Runx1 in ex vivo cultures of marrow stromal cells and calvarial derived osteoblasts from Runx1(lz/+) mice. These data indicate that Runx1 may contribute to the early stages of skeletogenesis and continues to function in the progenitor cells of tissues that support bone formation in the adult.

Abstract: The present invention relates to a composition for inducing chondrogenic differentiation comprising a culture of chicken bone marrow-derived osteochondral progenitor cells as an active ingredient. Starter chick bone marrow-derived osteochondral progenitor cells are high-quality osteochondral progenitor cells, which can be massively cultured due to high proliferating ability thereof and actively secrete various proteins for inducing the differentiation into chondrocytes. Thus, the composition for inducing chondrogenic differentiation of stem cells according to the present invention can provide a low-cost and high-efficiency chondrogenic differentiation inducer by using a culture of starter chick bone marrow-derived osteochondral progenitor cells without generation of a secondary ossification center. Accordingly, the present invention can be utilized as not only a therapeutic agent and adjuvant for cartilage injury disease requiring formation or regeneration of new cartilage, such as degenerative arthritis, rheumatoid arthritis, fracture, muscle tissue injury, plantar fasciitis, tennis elbow, calcific tendinitis, fracture nonunion, or joint injury caused by external injury, but also a functional health food for joint health.

Abstract: The present invention relates to a composition for promoting osteogenesis. More particularly, the present invention relates to the composition for promoting osteogenesis containing a culture of chicken bone marrow-derived osteochondral progenitor cells as an active component. When the culture of chicken bone marrow-derived osteochondral progenitor cells is used in combination with an existing chemical material-based differentiation inducer used for induction of osteocytes according to the present invention, stem cells can be differentiated into osteocytes more effectively compared to when an osteogenic differentiation inducer is used alone. Accordingly, the present invention is expected to be usable as not only a therapeutic agent and adjuvant for bone injury diseases requiring formation or regeneration of new bones, such as osteoporosis, bone defect disease, Paget′s disease, avascular necrosis of the femoral head, and osteoarthritis, but also a health functional food for bone health.

Abstract: Cell-based bone regeneration strategies offer promise for traumatic bone injuries, congenital defects, non-union fractures and other skeletal pathologies. Postnatal bone remodeling and fracture healing provide evidence that an osteochondroprogenitor cell is present in adult life that can differentiate to remodel or repair the fractured bone. However, cell-based skeletal repair in the clinic is still in its infancy, mostly due to poor characterization of progenitor cells and lack of knowledge about their in vivo behavior. Here, we took a combined approach of high-throughput screening, flow-based cell sorting and in vivo transplantation to isolate markers that identify osteochondroprogenitor cells. We show that the presence of tetraspanin CD9 enriches for osteochondroprogenitors within CD105+ mesenchymal cells and that these cells readily form bone upon transplantation. In addition, we have used Thy1.2 and the ectonucleotidase CD73 to identify subsets within the CD9+ population that lead to endochondral or intramembranous-like bone formation. Utilization of this unique cell surface phenotype to enrich for osteochondroprogenitor cells will allow for further characterization of the molecular mechanisms that regulate their osteogenic properties.