New findings pave the way for causative treatment of osteoporosis
Berlin – German researchers have identified a novel molecular target that paves the way for causative therapy of osteoporosis, the most common bone disease of post-meno¬pausal women. It is estimated that 1 in 3 women and 1 in 12 men over the age of 50 worldwide have osteoporosis, which causes high healthcare costs because the reduction in bone mineral density in course of the disease leads to an increased risk of fracture. Together with colleagues from the Netherlands and the US, researchers under Professor Achim Leutz from Berlin-based Max-Delbruck Center for Molecular Medicine discovered now that the observed disequilibrium between bone-forming cells (osteoblasts) and bone-resorbing osteoclasts is caused by an imbalance of two differently translated forms of the CCAAT/enhancer-binding protein beta (C/EBPbeta), which regulate transcription of the mafB gene. The long form of C/EBP-beta (“LAP”) led to mafB-directed inhibition of osteoclast formation, the short one (LIP) activated the production of the bone resorbing cells. Rapamycin, an inhibitor of mTOR increased the ratio of LAP over LIP and inhibited osteoclastogenesis. The researchers said they now want to find alternative regulators of C/EBPbeta translation that don’t show the immunosuppressive effects of Rapamycin.