Docosahexaenoic acid‐containing phosphatidylcholine induced osteoblastic differentiation by modulating key transcription factors

Abstract

In this study, the pro-osteogenic effects of docosahexaenoic acid-containing phosphatidylcholine (DHA-PC) were investigated both in vitro and in vivo. In vitro experiments showed that DHA-PC promoted mesenchymal stem cells (MSCs) proliferation and differentiation into osteoblasts. Luciferase reporter gene assay and western blotting indicated that DHA-PC significantly increased RUNX2 transcriptional activity and translation level. Although DHA-PC did not affect total peroxisome proliferator-activated receptor gamma (PPARγ) protein level, it promoted ERK-mediated phosphorylation of PPARγ at serine 112 locus, which was positively associated with osteogenesis. The effect of DHA-PC on osteogenic differentiation was further verified in MC3T3-E1 cells. In vivo experiments indicated that DHA-PC increased bone formation rate of adolescent mice. In summary, our study showed that DHA-PC promoted osteogenesis by up-regulating RUNX2 expression and ERK-mediated PPARγ serine 112 phosphorylation, which might provide an adjunctive therapy for the treatment of osteoporosis as a novel functional food. Practical applications Docosahexaenoic acid-containing phosphatidylcholine (DHA-PC), isolated from the squid roe, possesses unique biological activities owing to the properties of the constituent phospholipids and omega-3 polyunsaturated fatty acids. However, the protective effect of DHA-PC on osteogenesis is not known. This study demonstrated that squid roe DHA-PC promoted mesenchymal stem cells (MSCs) differentiation in vitro, and clarified the underlying mechanism of this action. Moreover, in vivo experiments confirmed the osteogenetic effect of DHA-PC, which may provide a basis for using DHA-PC as a functional food for accelerating bone formation.