Sialoglycoprotein isolated from Carassius auratus eggs promotes osteogenesis by stimulating mesenchymal stem cells to commit to osteoblast differentiation.

In this study, we explore whether the pro-osteogenic effects of sialoglycoprotein from Carassius auratus eggs (Ca-SGP) involve mesenchymal stem cells (MSCs). Ovariectomized osteoporotic mice treated with Ca-SGP had increased bone formation and reduced bone marrow adipose tissue. As MSCs are common progenitors of osteoblasts and adipocytes, we isolated MSCs from Ca-SGP-treated mice and found that they tended to differentiate into osteoblasts over adipocytes confirmed by Alizarin red and Oil red O staining. This change was seen at the gene and protein level. To further explore the effect of Ca-SGP on MSCs, we isolated MSCs from healthy mice and treated them with Ca-SGP in vitro. We discovered that Ca-SGP promoted MSC differentiation to osteoblasts. In addition, Ca-SGP promoted osteogenesis and reduced the fat in marrow cavity of adolescent mice. For the first time, our results demonstrate that Ca-SGP promotes osteogenesis via stimulating MSCs to commit to osteoblasts. Graphical Abstract ᅟ.