Adiponectin receptors are present in RANK-L-induced multinucleated osteoclast-like cells. (October 2013)

• Record Type: Journal Article
• Authors: Pacheco-Pantoja, Elda L.; Waring, Victoria J.; Wilson, Peter J. M.; Fraser, William D.; Gallagher, James A.
• Is Part Of: Journal of receptor and signal transduction research. Volume 33:Number 5(2013)
• Page Start: 291
• Page End: 297
• Publication Date: 2013-10
• Subjects: Cell receptors -- Periodicals; Cellular signal transduction -- Periodicals; 571.6
• DOI: 10.3109/10799893.2013.828070
• Languages: English
• ISSNs: 1079-9893

Abstract

<abstract> <title>Abstract</title> <p>Adiponectin is an adipokine that has been related to bone metabolism. Data on adiponectin receptors (AdipoR1, -R2) in osteoclasts have shown discrepancies. In this study we carried out observations of AdipoR1, -R2 in peripheral blood mononuclear cells that were induced to differentiate into osteoclasts. AdipoR1, -R2 were screened using reverse transcription and quantitative PCR and immunofluorescence. Acid phosphatase and Cathepsin-K were evaluated as osteoclastic markers. Results showed that acid phosphatase was expressed from day 1 whereas Cathepsin-K started from day 7. AdipoR1 and -R2 showed expression from day 1, with greater expression for AdipoR1 than AdipoR2. The immunofluorescent patterns were observed in the cells cultured under three different conditions: non-supplemented medium, added M-CSF, or medium with M-CSF, and RANK-L. The non-supplemented control did not display specific fluorescence whereas specific and strong signals were detected in cells cultured with combined M-CSF and RANK-L from day 7. The fluorescence patterns were detected mainly at the periphery of the cells, and in the cytoplasm, showing a localized patchy pattern for both receptors. In contrast, a diffuse fluorescent pattern was detected in the cytoplasm of the cells with M-CSF alone. In summary, AdipoR1 and -R2 were detected by quantitative PCR and immunofluorescence. The immunofluorescence patterns suggest that adiponectin receptors are located, or re-located, in the plasma membrane with distribution in the cytoplasm when mononuclear cells are committed to differentiate to osteoclasts. These findings could be a reasonable explanation for the controversy found in the published literature regarding the role of adiponectin in bone metabolism.</p> </abstract>