| First Author | Tamasi JA | Year | 2013 |
| Journal | J Bone Miner Res | Volume | 28 |
| Issue | 9 | Pages | 1975-86 |
| PubMed ID | 23519994 | Mgi Jnum | J:318174 |
| Mgi Id | MGI:6858589 | Doi | 10.1002/jbmr.1933 |
| Citation | Tamasi JA, et al. (2013) Monocyte chemoattractant protein-1 is a mediator of the anabolic action of parathyroid hormone on bone. J Bone Miner Res 28(9):1975-86 |
| abstractText | Parathyroid hormone (PTH) has a significant role as an anabolic hormone in bone when administered by intermittent injection. Previous microarray studies in our laboratory have shown that the most highly regulated gene, monocyte chemoattractant protein-1 (MCP-1), is rapidly and transiently induced when hPTH(1-34) is injected intermittently in rats. Through further in vivo studies, we found that rats treated with hPTH(1-34) showed a significant increase in serum MCP-1 levels 2 hours after PTH injection compared with basal levels. Using immunohistochemistry, increased MCP-1 expression in osteoblasts and osteocytes is evident after PTH treatment. PTH also increased the number of marrow macrophages. MCP-1 knockout mice injected daily with hPTH(1-34) showed less trabecular bone mineral density and bone volume compared with wild-type mice as measured by peripheral quantitative computed tomography (pQCT) and micro-computed tomography (microCT). Histomorphometric analysis revealed that the increase in osteoclast surface and osteoclast number observed with intermittent PTH treatment in the wild-type mice was completely eliminated in the MCP-1 null mice, as well as much lower numbers of macrophages. Consequently, the lack of osteoclast and macrophage activity in the MCP-1 null mice was paralleled by a reduction in bone formation. We conclude that osteoblast and osteocyte MCP-1 expression is an important mediator for the anabolic effects of PTH on bone. |
