title: Bone is a target for the antidiabetic compound rosiglitazone.
abstract: Rosiglitazone is an FDA-approved oral antidiabetic agent for the treatment of type 2 diabetes. This compound improves insulin sensitivity through the activation of the nuclear receptor, peroxisome proliferator-activated receptor-gamma (PPAR-gamma). In addition to sensitizing cells to insulin, the PPAR-gamma2 isoform appears to be critical for the regulation of osteoblast and adipocyte differentiation from common mesenchymal bone marrow progenitors. We have demonstrated previously that PPAR-gamma2 activated with rosiglitazone acts as a dominant inhibitor of osteoblastogenesis in murine bone marrow in vitro. Here, we show that in vivo, rosiglitazone administration results in significant bone loss. When rosiglitazone (20 microg/g body weight/d) was given to 6-month-old, nondiabetic C57BL/6 mice for 7 wk, a significant decrease in total body bone mineral density was observed. Analysis of bone microarchitecture, using micro-computed tomography, demonstrated a decrease in bone volume, trabecular width, and trabecular number and an increase in trabecular spacing. Histomorphometric analysis showed a decrease in bone formation rate, with a simultaneous increase in fat content in the bone marrow. Changes in bone morphology and structure were accompanied by changes in the expression of osteoblast- and adipocyte-specific marker genes; the expression of the osteoblast-specific genes Runx2/Cbfa1, Dlx5, and alpha1(I)collagen were decreased, whereas the expression of the adipocyte-specific fatty acid binding protein aP2, was increased. These in vivo data suggest that rosiglitazone therapy may pose a significant risk of adverse skeletal effects in humans.
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D001853:Bone Marrow / Q000187:drug effects; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D013977:Tibia / Q000187:drug effects*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D007004:Hypoglycemic Agents; D018160:Receptors, Cytoplasmic and Nuclear; D045162:Thiazolidinediones; D014157:Transcription Factors; D000077154:Rosiglitazone