Oscillatory fluid flow regulates glycosaminoglycan production via an intracellular calcium pathway in meniscal cells
Document Type
Article
Publication Date
3-1-2006
Department
Department of Mechanical Engineering-Engineering Mechanics
Abstract
Mechanical loading in the form of oscillatory fluid flow-induced shear stress was applied to meniscal cells while the biochemical response [intracellular calcium mobilization and sulfated glycosaminoglycan (GAG) production] was studied. Isolated rabbit meniscal cells were cultured onto microscope slides and placed in a parallel plate flow chamber. Cells were exposed to oscillating fluid flow-induced shear stresses of 4 Pa for sulfated GAG studies and 0-6.5 Pa for calcium studies. The calcium response was monitored using a fluorescent probe and imaging techniques, sulfated GAG production was measured using the modified 1,9-dimethylmethylene blue method, and thapsigargin was used to block intracellular calcium ([Ca2+]i) mobilization. A significant dose-dependent relationship was found for the percentage of cells responding to oscillating fluid flow with an increase in [Ca2+]i versus shear stress level. The percentage of cells responding decreased linearly from 72% ± 17% at 6.5 Pa to 28% ± 7% at 2.0 Pa to 2% ± 1% for baseline no-flow (0 Pa). No differences were found in the amplitude of the calcium response of responding cells for any shear stress level. Oscillating fluid flow-induced shear stresses of 4 Pa produced a significantly greater amount of sulfated GAGs (253 ± 95 ng GAG/μg cell protein) compared to the no-flow control (158 ± 86 ng/μg). The addition of thapsigargin to the media inhibited both the intracellular calcium response to oscillating fluid flow (less than 1.5% of the cells responded) and the increase in GAG production following oscillating fluid flow, which was returned to control levels (170 ± 72 ng/ μg). These findings suggest that oscillatory fluid flow-induced shear stress increases intracellular calcium levels and sulfated GAG production. Furthermore, they suggests that calcium may modulate the biochemical pathway that leads to sulfated GAG production.
Publication Title
Journal of Orthopaedic Research
Recommended Citation
Eifler, R.,
Blough, E.,
Dehlin, J.,
&
Haut Donahue, T.
(2006).
Oscillatory fluid flow regulates glycosaminoglycan production via an intracellular calcium pathway in meniscal cells.
Journal of Orthopaedic Research,
24(3), 375-384.
http://doi.org/10.1002/jor.20028
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/3750
Publisher's Statement
© 2005 Orthopaedic Research Society. Publisher’s version of record: https://doi.org/10.1002/jor.20028