Fibrillin-1 regulates periostin expression during maintenance of periodontal homeostasis

Background/purpose: Human periodontal ligament consists of elastic system fibers, mainly fibrillin-1 (FBN1). Periostin (POSTN) maintains periodontal homeostasis. A previous study showed that the expression of Postn in periodontal ligament cells was decreased in mice underexpressing Fbn1. However, the relationship between FBN1 and POSTN is not fully under-stood in the context of mechanical stress. FBN1 contributes to transforming growth factor 01 (TGF-01) activation; TGF-01 upregulates the expression of POSTN in human periodontal liga-ment cells. This study examined whether FBN1 contributed to the maintenance of periodontal homeostasis in cultured human periodontal ligament cells.Materials and methods: Human periodontal ligament fibroblasts (HPDLFs) were exposed to me-chanical force via centrifugation. The expression of POSTN was examined by quantitative reverse transcription polymerase chain reaction. The phosphorylation of Smad2 in the TGF-0/Smad signaling pathway was monitored by western blotting. Results: The expression levels of FBN1 and POSTN were not significantly decreased by centri-fugation. However, the expression of POSTN after centrifugation significantly decreased upon knockdown of FBN1. The phosphorylation of Smad2 after centrifugation was decreased, regardless of FBN1 knockdown. Supplementation with 0.1 ng/ml recombinant human TGF-01 rescued POSTN expression after centrifugation in HPDLFs upon knockdown of FBN1.Conclusion: FBN1 regulates the expression of POSTN to maintain periodontal homeostasis via TGF-13/Smad signaling during centrifugation.(c) 2022 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).