IADR Abstract Archives

Stress-induced IL-1β Release In HPDL Via Vesicles And P2X7R/Pannexin-1 Complex

Introduction: Mechanical stress is one of the factors involved in the homeostasis of periodontium. Previous studies showed mechanical stress induced the release of ATP and cytokines in human periodontal ligament (HPDL) cells. Objective: The aim of this study was to examine the mechanism of mechanical stress on the release of inflammatory cytokines. Methods: HPDL cells were subjected to compressive stress by direct loading of weight on the culture. The expression and release of IL-1β were examined by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The molecular mechanism of stress-induced cytokine expression was investigated by means of inhibitors. Results: Mechanical stress induced expression of IL-1β mRNA and proteins in HPDL cells, when compared to the control in a force dependent manner. The induction was inhibited by probenecid (pannexin-1 hemichannel inhibitor) and KN-62 (P2X7 receptor antagonist), suggesting the involvement of hemichannel gap junction and P2/nucleotide receptors. Interestingly, addition of vesicular trafficking inhibitors, monensins, N-ethylmaleimide (NEM) and brefeldin-A significantly attenuated the release of both ATP and IL-1β. Immunocytochemistry approach revealed the co-localization of Pannexin-1 and P2X7 receptor on the membrane of HPDL cells. Moreover, the membrane translocation of SNAP-25, a core protein of vesicular-membrane fusion SNARE complex, after stress treatment and co-localization of SNAP-25 with P2X7 receptor were observed. Conclusion: The results from this study indicated that mechanical stress could directly regulate the expression of IL-1β in HPDL cells. The induction involved the function of Pannexin-1 and P2X7 receptor. The release of IL-1β was also depended on the vesicular trafficking. It is possible that Pannexin-1, in combination with P2X7 receptor, could function in docking the vesicular release of IL-1β upon mechanical stress activation in HPDL cells. Taken together, our results raised the possibility of the novel function of hemichannels as a docking site for vesicular release.
Japanese Division Meeting
2011 Japanese Division Meeting (Hiroshima, Japan)
Hiroshima, Japan
2011

Scientific Groups
  • Kanjanamekanant, Kavita  ( Chulalongkorn University, Bangkok, N/A, Thailand )
  • Luckprom, Pimporn  ( Chulalongkorn University, Bangkok, N/A, Thailand )
  • Pavasant, Prasit  ( Chulalongkorn University, Bangkok, N/A, Thailand )
  • Periodontal Research