Journal
JOURNAL OF RHEUMATOLOGY
Volume 40, Issue 5, Pages 684-694Publisher
J RHEUMATOL PUBL CO
DOI: 10.3899/jrheum.120845
Keywords
OSTEOBLASTS; OSTEOPOROSIS; OSTEOARTHRITIS; WNT SIGNALING; RANKL/OPG
Categories
Ask authors/readers for more resources
Objective. To evaluate the expression of Dicickopf-1 protein factor (DICK-1), DKK-2, and beta-catenin, components of the Wnt pathway, in human osteoarthritic (OA) and osteoporotic (OP) osteoblasts and to correlate it to cell metabolic activity, proliferation, and receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) expression. Methods. Primary human osteoblast cultures were obtained from healthy, OA, and OP donors. In each cell population we evaluated DICK-1, DKK-2, nonphosphorylated beta-catenin and RANKL/OPG expression, osteocalcin and alkaline phosphatase (ALP) synthesis, and cell proliferation, both in basal condition and after vitamin D3 stimulation. Results. DICK-1 and DICK-2 showed opposite patterns of expression in OA and OP osteoblasts. The RANKL/OPG ratio was significantly higher in the OP group because of a greater expression of RANKL, whereas it was significantly lower in the OA group because of a higher expression of OPG. Treatment with vitamin D3 increased the RANKL/OPG ratio and DKIC-2 expression and reduced DICK-1 expression in each cell population, but did not affect beta-catenin levels. Both osteooalcin and ALP production and cell proliferation were enhanced in OA cells and reduced in the OP ones. Conclusion. These data confirm that OA and OP are characterized by opposite bone changes, consisting of reduced bone remodeling processes with increased osteoblast activity in OA, and enhanced bone resorptive activity with reduction of osteoblast metabolism in OP, and suggest that the Wnt pathway is involved in the pathogenesis of both diseases.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available