title: Gap junctions and fluid flow response in MC3T3-E1 cells.
abstract: In the current study, we examined the role of gap junctions in oscillatory fluid flow-induced changes in intracellular Ca(2+) concentration and prostaglandin release in osteoblastic cells. This work was completed in MC3T3-E1 cells with intact gap junctional communication as well as in MC3T3-E1 cells rendered communication deficient through expression of a dominant-negative connexin. Our results demonstrate that MC3T3-E1 cells with intact gap junctions respond to oscillatory fluid flow with significant increases in prostaglandin E(2) (PGE(2)) release, whereas cells with diminished gap junctional communication do not. Furthermore, we found that cytosolic Ca(2+) (Ca) response was unaltered by the disruption in gap junctional communication and was not significantly different among the cell lines. Thus our results suggest that gap junctions contribute to the PGE(2) but not to the Ca response to oscillatory fluid flow. These findings implicate gap junctional intercellular communication (GJIC) in bone cell ensemble responsiveness to oscillatory fluid flow and suggest that gap junctions and GJIC play a pivotal role in mechanotransduction mechanisms in bone.
authors.affiliation: Musculoskeletal Research Laboratory, Department of Orthopedics and Rehabilitation, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania 17033, USA. msaunder@mrl.hmc.psu.edu
authors.forename: M M
authors.initials: MM
authors.lastname: Saunders
authors.forename: J
authors.initials: J
authors.lastname: You
authors.forename: J E
authors.initials: JE
authors.lastname: Trosko
authors.forename: H
authors.initials: H
authors.lastname: Yamasaki
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: H J
authors.initials: HJ
authors.lastname: Donahue
authors.forename: C R
authors.initials: CR
authors.lastname: Jacobs
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D015232:Dinoprostone / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017629:Gap Junctions / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011673:Pulsatile Flow; D013314:Stress, Mechanical; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D019284:Thapsigargin; D015232:Dinoprostone; D002118:Calcium