ABSTRACT
BACKGROUND AND OBJECTIVE: The mechanism behind the survival of periodontal ligament fibroblasts is critical for the maintenance of periodontal ligament tissue. However, the number of known proteins that are involved in this action is limited. The aim of this study was to examine the role of a novel molecule, secreted mammalian Ly-6/urokinase-type plasminogen activator receptor-related protein 1 (SLURP-1), in periodontal ligament fibroblast survival. MATERIAL AND METHODS: Human periodontal ligament fibroblasts were isolated from eight healthy human donors using established protocols. Gene expression for SLURP-1 was analysed using the reverse transcriptase-polymerase chain reaction, while protein expression was examined by immunoblotting with a SLURP-1 antibody. In addition, the apoptotic effect was examined using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. RESULTS: Messenger RNA for SLURP-1 was expressed in the periodontal ligament, gingival fibroblasts, oral keratinocytes and bone. Moreover, the protein was secreted by both periodontal ligament and gingival fibroblasts. Functional analysis revealed that SLURP-1 substantially enhanced cell survival in periodontal ligament fibroblasts by the anti-apoptotic signal phosphatidylinositol 3-kinase. CONCLUSION: These findings suggest that SLURP-1 may play an important role in the control and maintenance of the periodontal ligament by protecting the periodontal ligament fibroblasts from apoptosis.
Subject(s)
Fibroblasts/metabolism , Periodontal Ligament/cytology , Urokinase-Type Plasminogen Activator/metabolism , Adolescent , Androstadienes/pharmacology , Antigens, Ly/analysis , Apoptosis/physiology , Bone and Bones/cytology , Bone and Bones/metabolism , Camptothecin/pharmacology , Cell Line , Cell Survival/physiology , Cells, Cultured , Child , Enzyme Inhibitors/pharmacology , Female , Fibroblasts/cytology , Gingiva/cytology , Gingiva/metabolism , Humans , Immunoblotting , In Situ Nick-End Labeling , Keratinocytes/metabolism , Male , Mouth Mucosa/cytology , Mouth Mucosa/metabolism , Periodontal Ligament/metabolism , Phosphatidylinositol 3-Kinases/physiology , Phosphoinositide-3 Kinase Inhibitors , Reverse Transcriptase Polymerase Chain Reaction , Topoisomerase I Inhibitors , Urokinase-Type Plasminogen Activator/analysis , WortmanninABSTRACT
The intercellular communication between osteoblasts and osteoclasts is crucial to bone homeostasis. Since Rodan and Martin proposed the control of osteoclasts by osteoblasts in the 1980s, many factors have been isolated from osteoblasts and shown to regulate the differentiation and function of osteoclasts. However, the mechanism by which osteoblasts regulate osteoclasts during bone remodelling is still unclear. On the other hand, it is well accepted that many metabolic bone diseases are associated with the disruption of the communication between osteoblast and osteoclasts. Thus, this review focuses on the cross-talk between osteoblasts and osteoclasts and its impact in bone disease.
