Osteoclastogenesis is negatively regulated by D-serine produced by osteoblasts.

摘要: We have shown the functional expression by chondrocytes of serine racemase (SR) which is responsible for synthesis D-serine (Ser) from L-Ser in cartilage. In this study, we evaluated possible SR bone-forming osteoblasts and bone-resorbing osteoclasts. Expression mRNA was seen localized at cancellous bone surface neonatal rat tibial sections cultured calvarial endowed to release D-Ser into extracellular medium, but not osteoclasts differentiated murine marrow progenitor cells. Sustained exposure failed significantly affect alkaline phosphatase activity Ca2+ accumulation osteoblasts, inhibited differentiation maturation a concentration-dependent manner concentration range 0.1–1 mM without affecting cellular survival By contrast, promoted osteoclastic sensitive inhibition D-Ser. Matured expressed amino acid transporter B0,+ (ATB0,+) system alanine, serine, cysteine transporter-2 (ASCT2), are individually capable similarly incorporating L- Knockdown these transporters siRNA prevented both promotion pre-osteoclastic RAW264.7 These results suggest that may play pivotal role osteoclastogenesis through mechanism related incorporation mediated ATB0,+ ASCT2 enantiomers after subsequent adjacent osteoblasts. J. Cell. Physiol. 227: 3477–3487, 2012. © 2012 Wiley Periodicals, Inc.