The Journal of Membrane Biology

, Volume 245, Issue 7, pp 401–409

Connexin43 and Pannexin1 Channels in Osteoblasts: Who Is the “Hemichannel”?

  • Mia M. Thi
  • Shalena Islam
  • Sylvia O. Suadicani
  • David C. Spray
Article

DOI: 10.1007/s00232-012-9462-2

Cite this article as:
Thi, M.M., Islam, S., Suadicani, S.O. et al. J Membrane Biol (2012) 245: 401. doi:10.1007/s00232-012-9462-2

Abstract

Osteoblasts sense and respond to mechanical stimuli in a process involving influx and release of large ions and signaling molecules. Unapposed gap junction hemichannels formed of connexin43 (Cx43) have been proposed as a major route for such exchange, in particular for release of ATP and prostaglandin E2 (PGE2) in osteocytes. However, we have found that Cx43-null osteoblasts have unaltered, mechanically induced PGE2 release and ATP-induced YoPro dye uptake. In contrast, PGE2 release in response to fluid shear stress is abolished in P2X7 receptor (P2X7R)–null osteoblasts, and ATP-induced dye uptake is attenuated following treatment of wild-type cells with a P2X7R or Pannexin1 (Panx1) channel blocker. These data indicate that Panx1 channels, in concert with P2X7R, likely form a molecular complex that performs the hemichannel function in osteoblast mechanosignaling.

Keywords

P2X7RATPOsteoblastGap junctionDye uptake

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Mia M. Thi
    • 1
    • 2
  • Shalena Islam
    • 3
  • Sylvia O. Suadicani
    • 2
    • 4
  • David C. Spray
    • 2
  1. 1.Department of Orthopedic SurgeryAlbert Einstein College of MedicineBronxUSA
  2. 2.Department of NeuroscienceAlbert Einstein College of MedicineBronxUSA
  3. 3.Department of BiologyThe City College of New YorkNew YorkUSA
  4. 4.Department of UrologyAlbert Einstein College of MedicineBronxUSA