Dr. Partridge's research focuses on parathyroid hormone (PTH) regulation of gene expression by the osteoblast. In one project, her laboratory is investigating how PTH, acting through protein kinase A (PKA), signals to nuclear chromatin of the osteoblast and causes co-repressor proteins (e.g. histone deacetylases) to dissociate from, and co-activator proteins (e.g. histone acetyltransferases) to associate with a gene. Matrix metalloproteinase-13 (MMP-13, collagenase-3) is the gene under investigation. In a second project, Dr. Partridge's laboratory is examining how PTH has its anabolic effects on bone. They have found that the gene most highly regulated by PTH in an anabolic (daily injection) protocol is monocyte chemoattractant protein-1 (MCP-1). Her laboratory has shown that the anabolic effect of PTH is abolished in MCP-1 null mice. In addition, PTH is unable to recruit osteoclasts in these mice. They have concluded that PTH acts via MCP-1 to stimulate osteoclasts which are then necessary for PTH's anabolic effects. Other projects involve examination of Wnt-4 effects on mesenchymal stem cells and osteoblasts, and how pulsed electromagnetic fields act on osteoblasts.
