The analyses on bone and cartilage diseases caused by mutations of FGFR3/PTHrP genes

点击翻译按钮获取中文摘要

We conducted the broad analyses on the biological function of fibroblast growth factor receptor type III (FGFR3) and parathyroid hormone-related peptide (PTHrP), by employing gene targeted mice, cells transgenes with mutated PTH/PTHrP receptors and bone metastatic mice with PTHrP-overexpressing tumors. In 2004, we have generated FGFR3^<-/->/PTHrP^<-/-> mice, and examined the skeletal deformities on bone and cartilage. As a results, PTHrP dominantly affected on the chondrocyte proliferation, rather than FGFR3. However, FGFR3 could influence the apoptosis and VEGF expression in chondrocytes after their entry to hypertrophic phenotype. In 2005, we have reported that PTHrP stimulated osteoblastic proliferation and survival in an autocrine/paracrine manner. Also, we provided the strong possibility that proteins of mutated PTH/PTHrP receptors, inducing Jansen type and Blomstrand type chondrodysplasia, would be accumulated in endoplasmic reticulum, and subsequent be leaked into the cytoplasmic region. Therefore, the mutant receptors would not be normally targeted to the cell membranes. In addition, we have morphologically examined the metastastic lesion by PTHrP-overexpressing tumors. Thus, we assessed the skeletal pathological features caused by the mutations and abnormal expression of FGFR3 and/or PTHrP genes.