Galanin receptor agonists limit osteoclast number in in vitro mouse models

Author(s): Heath W McGowan, Deanna M Horvath, Amy E Larsen, Aaron C McDonald.

Despite evidence that galanin-like compounds are potential regulators of bone activity, little research has been undertaken to investigate the role of these compounds on osseous cells. The aim of this study was to elucidate the mechanisms by which the galanin receptor agonist’s galanin and galnon regulate osteoclasts. Osteoclasts were cultured from cells isolated from femurs of C57BL/6 mice and grown to 80% confluence, then differentiated via the application of mCSF and RANKL. Cultures were analyzed for osteoclast number via TRAP staining, qPCR and immunocytochemistry. A moderate dose of both galanin-like compounds decreased osteoclast count in vitro . The moderate dose of galanin also reduced expression of inflammatory markers. These results indicate that both galanin and galnon can act to reduce osteoclast count, although they have led to contradictory responses with respect to inflammatory expression. These results may help to better treatment for bone-resorptive diseases such as osteoporosis.