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Rho kinase-dependent CCL20 induced by dynamic compression of human chondrocytes
- Source :
- Arthritis & Rheumatism. 58:2735-2742
- Publication Year :
- 2008
- Publisher :
- Wiley, 2008.
-
Abstract
- Objective Mechanical stimulation of cartilage affects tissue homeostasis and chondrocyte function. The chondrocyte phenotype is dependent on cell shape, which is largely determined by the actin cytoskeleton. Reorganization of the actin cytoskeleton results from Rho GTPase activation. The purpose of this study was to examine the roles of both actin and Rho in mechanotransduction in chondrocytes. Methods We embedded human articular chondrocytes in 2 × 6–mm agarose discs at 5 × 106 cells/ml and subjected the discs to unconfined dynamic compression at 0.5 Hz. By comparing samples with and without dynamic compression, we identified Rho activation according to the GTP-bound active RhoA measured in cell lysates. We identified rearrangements in filamentous actin structures using fluorescence-labeled phalloidin and confocal microscopy of fixed samples. We identified altered gene expression using TaqMan quantitative reverse transcription–polymerase chain reaction analysis. We tested for a requirement for Rho signaling by performing the dynamic compression in the presence of Rho kinase inhibitors. Results RhoA activation occurred within 5–10 minutes of dynamic compression. Rho kinase–dependent actin reorganization occurred within 20 minutes after application of dynamic compression and was apparent as “punctate” F-actin structures that were visible under confocal microscopy. We identified early-phase mechanoresponsive genes (CCL20 and inducible nitric oxide synthase) that were highly up-regulated within 1 hour of dynamic compression in a Rho kinase–dependent and actin-dependent manner. Conclusion Together, these results are the first demonstration that the Rho–Rho kinase pathway and actin cytoskeletal reorganization are required for changes in the expression of genes involved in human chondrocyte mechanotransduction.
- Subjects :
- Adult
Male
Time Factors
RHOA
Adolescent
Phalloidin
Interleukin-1beta
Immunology
Cell Culture Techniques
Gene Expression
Nitric Oxide Synthase Type II
Biology
Mechanotransduction, Cellular
Filamentous actin
Article
Chondrocyte
chemistry.chemical_compound
Chondrocytes
Rheumatology
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
Physical Stimulation
Osteoarthritis
medicine
Humans
Immunology and Allergy
Pharmacology (medical)
RNA, Messenger
Cytoskeleton
Cell Shape
Rho-associated protein kinase
Cells, Cultured
rho-Associated Kinases
Chemokine CCL20
Microscopy, Confocal
Reverse Transcriptase Polymerase Chain Reaction
Middle Aged
Actin cytoskeleton
Actins
Cell biology
medicine.anatomical_structure
chemistry
biology.protein
Female
Stress, Mechanical
MDia1
Subjects
Details
- ISSN :
- 15290131 and 00043591
- Volume :
- 58
- Database :
- OpenAIRE
- Journal :
- Arthritis & Rheumatism
- Accession number :
- edsair.doi.dedup.....8bba39623c81f76c1491ba8084a1b5a0