Figure 7
MCP-1 promotes osteoclastogenesis in vitro and MCP-1 null mice exhibited impaired PTH-mediated bone marrow osteoclast formation. (A) Bone marrow cells from WT or MCP-1−/− mice were induced to differentiate towards the osteoclast lineage with M-CSF and RANKL for 7 days in the presence or absence of exogenous MCP-1 (50 ng/ml). Cultures were stained for TRAP and photographed by light microscopy. (B–D) RT-qPCR analyses showing mRNA expression of osteoclast markers (TRAP, Cathepsin K and NFATc1) using the same cells as in (A) (n = 3). *p < 0.05 compared to cells from WT mice treated with M-CSF and RANKL, †p < 0.05 compared to MCP-1−/− BMMs treated with M-CSF and RANKL. (E) Bone marrows from WT and MCP-1−/− mice were cultured for 10 days in the presence or absence of hPTH(1–34; 10−9 or 10−8M) and/or MCP-1 (50 ng/ml) to induce osteoclast formation. Cultures were stained for TRAP to identify multinucleated TRAP-positive cells. Representative images by light microscopy (4X). (F–H) Bone marrows from WT and MCP-1−/− mice were cultured for 10 days in the presence or absence of hPTH(1–34; 10−9 or 10−8M) and/or MCP-1 (50 ng/ml) to induce osteoclast formation. Isolated RNAs were used for RT-qPCR analysis of osteoclast specific gene expression (TRAP, cathepsin K and carbonic anhydrase). *p < 0.05, **p < 0.01, ***p < 0.001 compared to Control cells from WT mice and †p < 0.05, †††p < 0.001 compared to Control + MCP-1 -treated cells from MCP-1−/− mice.
