No abstract

ABSTRACT. Daidzein, the most widely studied soy phytoestrogen, is not only a potential antiosteoporosis agent owing to its possible osteogenic activity, but also shows anticancer activity. However, the mechanisms through which daidzein affects osteoblast function have not been investigated thoroughly. Here, we show that daidzein stimulated cell proliferation and differentiation of osteoblasts, demonstrated by upregulation of XTT activity, enhancement of alkaline phosphatase (ALP) activity, and upregulation of osteoblast-specific marker genes, including Runt-related transcription factor 2 (Runx2) and Smad1, as well as upregulation of Runx2 and Smad1 protein expression. To determine the mechanisms underlying daidzein's effects on osteoblast differentiation, we first tested the role of daidzein in bone morphogenetic protein (BMP)-2 gene expression in OCT1 cells, and found that it significantly upregulated the expression of BMP-2. Furthermore, it significantly enhanced the phosphorylated protein level of Smad1/5/8 and the protein level of Osterix and increased the activity of 12xSBE-OC-Luc. Finally, we demonstrated that daidzein stimulated Col I, Runx2, and ALP expression, while these effects were significantly blocked by the BMP signaling inhibitor noggin. Together, our data indicate that daidzein acts through stimulating the activation of BMP-2/Smads pathway to promote osteoblast proliferation and differentiation.

Hypoxia is a crucial microenvironment for inflamed periodontal tissue and periodontal wound healing. Enamel matrix proteins (EMPs) potentially can promote the formation of new periodontium. The effects of EMPs on periodontal ligament cells under hypoxia, however, remain unclear. We investigated the effects of EMPs on cellular biobehavior and osteogenic differentiation of human periodontal ligament cells (hPDLCs) under hypoxia. Under cobalt chloride (CoCl)-induced hypoxia, cellular biobehavior of hPDLCs, including proliferation, attachment, spreading, and migration with or without EMPs, was evaluated by 3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), cell counting, spreading area measurement and wound scratch assay. The osteogenic activity of hPDLCs was assessed using alkaline phosphatase (ALP) and alizarin red S staining (ARS). The expressions of osteogenic genes including runt related transcription factor 2 (Runx2), ALP, osteocalcin (OCN) and collagen type I (Col-I) were detected using real time quantitative PCR, western blot and immunocytochemistry assays. The biobehavior and osteogenic differentiation of hPDLCs were inhibited significantly under hypoxia. EMPs have no effect on cell proliferation under mimicked hypoxia. EMPs partly reversed the inhibitory effects of hypoxia, however, for other cellular biobehavior including attachment, spreading and migration, and markedly up-regulated osteogenic differentiation activities including ALP, mineralization ability and the expressions of osteogenic genes such as Runx2, ALP, osteocalcin, and collagen type I in hPDLCs under hypoxia. EMPs attenuate the hypoxic injury to cellular biobehavior and osteogenic differentiation in hPDLCs under hypoxia.

The RDW levels were highest in the HPSN group, suggesting that RDW, especially the combination of RDW and ESR, may have value when assessing the risk of HSPN.