Fluoride Action Network


Fluoride (F) is capable of promoting abnormal proliferation and differentiation in primary cultured mouse osteoblasts(OB cells), although; the underlying mechanism responsible remain rare. This study aimed to explore the roles of Wingless and INT-1(Wnt) signaling pathways and screen appropriate doses of calcium (Ca2+) to alleviate the sodium fluoride (NaF)-induced OB cells toxicity. For this, we evaluated the effect of Dickkopf-related protein 1 (DKK1) and Ca2+ on mRNA levels of wingless/integrated 3a (Wnt3a), low-density lipoprotein receptor-related protein 5 (LRP5), Dishevelled 1 (Dv1), glycogen synthase kinase 3B (GSK3B), B-catenin, lymphoid enhancer binding factor 1 (LEF1), and cellular myelocytomatosis oncogene (cMYC), as well as Ccnd1 (Cyclin D1) in OB cells challenged with 10-6 moL/L NaF for 24 h. Data demonstrated showed that F significantly increased the OB cells proliferation rate. Ectogenic 0.5 mg/L DKK1 significantly inhibited the proliferation of OB cells induced by F. The mRNA expression levels of Wnt 3a, LRP5, Dv1, LEF1, B-catenin, cMYC and Ccnd1 were significantly increased in F group, while significantly decreased in 10-6 moL/L NaF+0.5 mg/L DKK1 (FY) group. The mRNA expression levels of Wnt3a, LRP5, B-catenin and cMYC were significantly decreased in 10-6 moL/L NaF+2 mmoL/L CaCl2 (F+CaII) group. The proteins expression levels of Wnt3a, Cyclin D1, cMYC and B-catenin were significantly increased in F group whereas decreased in the F+CaII group. However, the mRNA and protein expression levels of GSKB were significantly decreased in the F group while significantly increased in the F+CaII group. In summary, F activated the canonical Wnt/B-catenin pathway, changed the related genes expression and B-catenin protein location in OB cells, promoting cell proliferation. 2 mmoL/L Ca2+ supplementation reversed the expression levels of genes and proteins related to the canonical Wnt/B-catenin pathway.