Study On Experimental Conditions Of Induced Maturation Of Mouse Osteoclast Precursor Cells

Objective:To observe whether RAW264.7 cells, a mouse monocytes cell line, can be induced differentiation to mature osteoclast by RANKLMethods:After RAW264.7 cells were treated with RANKL for 9 to 15 days, cells morphological changes were observed by light microscope, transmission electron microscope (TEM) and scanning electron microscope (SEM);Staining TRAP-positive multinucleated cells were observed by Inverted Phase Contrast Microscope (IPCM); Expressions of osteoclast phenotype and function genes were detected by Semiquantitative RT-PCR, and the resorption pits that formed on the bone slices by osteoclasts were observed with SEM.Results:Light microscopy, TEM showed the treated cells became enlarged with 5 to 10 nucleus, and cells were oval-shaped or irregular; Scanning electron microscopy demonstrated that there were pseudopodia-like protrusions on the surface of the most cells. Furthermore, RAW264.7 cells treated with RANKL displayed TRAP positive staining multinucleated osteoclasts with more than 5 nucleus; the treated cells did not only possessed effect of bone resorption, but also up-regulated typical osteoclast phenotype and function genes expression , for example Cathepsin-K, TRAP, as well as RANK.Conclusion:RAW264.7 cells could be used as a perfect model of osteoclast precursors , and single 50ng/mL RANKL treatment could significantly induce them to the mature osteoclasts.