Ninjurin1 positively regulates osteoclast development by enhancing the survival of prefusion osteoclasts

Abstract

Bone development: Regulating the remodelers A protein called ninjurin1 regulates the activity of bone-degrading osteoclast cells, and may play an important role in various skeletal degenerative disorders. Normal skeletal development requires careful coordination by bone-building osteoblasts and by osteoclasts, which break down and remodel bone. Researchers led by Kyu-Won Kim of Seoul National University in South Korea have shown that ninjurin1 regulates both the development and survival of osteoclasts. They generated genetically modified mice that lack this protein, and observed notable skeletal defects, including abnormal accumulation of bone mass in long bones such as the femur. Elevated ninjurin1 levels are a feature of conditions such as osteoporosis and rheumatoid arthritis, and the researchers propose that therapeutic agents that target this molecule could help control the bone damage caused by improperly regulated osteoclasts.