An unbalanced diet can have adverse effects on health. Long chain polyunsaturated fatty
acids (LCPUFAs) have been the focus of research owing to their necessity of inclusion in a
healthy diet. However, the effects of LCPUFAs on human osteoclast formation and function
have not been explored before. A human CD14+ monocyte differentiation model was used
to elucidate the effects of an ω-3 LCPUFA, docosahexaenoic acid (DHA), and an ω-6
LCPUFA, arachidonic acid (AA), on osteoclast formation and activity. CD14+ monocytes
were isolated from peripheral blood of healthy donors and stimulated with macrophage colony
stimulating factor and receptor activator of nuclear factor kappa-B ligand to generate osteoclasts.
Data from this study revealed that both the LCPUFAs decreased osteoclast
formation potential of CD14+ monocytes in a dose-dependent manner when treated at an
early stage of differentiation. Moreover, when exposed at a late stage of osteoclast differentiation
AA and DHA impaired the bone resorptive potential of mature osteoclasts without affecting
osteoclast numbers. AA and DHA abrogated vitronectin receptor expression in
differentiating as well as mature osteoclasts. In contrast, the degree of inhibition for calcitonin
receptor expression varied between the LCPUFAs with only AA causing inhibition during
osteoclast differentiation. Furthermore, AA and DHA down regulated the expression of key
osteoclast-specific genes in differentiating as well as mature osteoclasts. This study demonstrates
for the first time that LCPUFAs can modulate osteoclast formation and function in
a human primary osteoclast cell line.
S1 Fig. Effects of AA and DHA on cell viability. CD14+ monocytes were treated with indicated
concentrations of AA and DHA for 48 h and cell viability was measured by alamar blue
assay. The results are representative of two independent experiments conducted in triplicate
and expressed as percentage cell viability relative to the control.