| Theme |
New Aspects of Parathyroid Hormone |
| Title |
Biological action of PTH / PTHrP receptor on skeletal tissue |
| Author |
Norio Amizuka |
Center for Transdisciplinary Research, Niigata University |
| Author |
Minqi Li |
Center for Transdisciplinary Research, Niigata University |
| [ Summary ] |
Parathyroid hormone (PTH) receptor (PTH-R1) common to PTH-related peptide (PTHrP) is expressed mainly in preosteoblasts, osteoblasts, chondrocytes and renal epithelial cells. As a result of mice carrying PTH-R1 without activating phospholipase C or chondrocyte-specific deletion of the G protein G (s) alpha. PKA / cAMP a signaling link to PTH-R1 appears to be the main pathway, regulating chondrocytic proliferation and differentiation PTHrP seems to modulate chondrocyte proliferation by mediating p57Kip2, while it appears to inhibit chondrocyte differentiation to enter the hypertrophic phenotype by mediating Indian hedgehog. In addition to chondrocytic regulation, PTHrP regulates osteoblastic proliferation and apoptosis in an autocrine / paracrine manner. Recent reports on PTHrP and PTH-R1 skeletal activity are reviewed. |