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Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs

Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs
Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs
Introduction: The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression.

Methods: Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1? (IL-1?), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data.

Results: CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1?. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1? (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1?, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1?-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1?-treated constructs.

Conclusions: Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1?. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old.

1478-6354
R145-[12pp]
Ramachandran, M.
132897fa-e457-4bb7-a6e4-3fb2cc18c454
Achan, P.
c7c8196d-0972-48c7-85d8-1b8fafee14ad
Salter, D.M.
94485705-ebda-4ddf-96c9-55fc6c3fe073
Bader, Dan L.
9884d4f6-2607-4d48-bf0c-62bdcc0d1dbf
Chowdhury, T.T.
3969bc1d-acec-4cad-b523-c8b4885fcb0a
Ramachandran, M.
132897fa-e457-4bb7-a6e4-3fb2cc18c454
Achan, P.
c7c8196d-0972-48c7-85d8-1b8fafee14ad
Salter, D.M.
94485705-ebda-4ddf-96c9-55fc6c3fe073
Bader, Dan L.
9884d4f6-2607-4d48-bf0c-62bdcc0d1dbf
Chowdhury, T.T.
3969bc1d-acec-4cad-b523-c8b4885fcb0a

Ramachandran, M., Achan, P., Salter, D.M., Bader, Dan L. and Chowdhury, T.T. (2011) Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs. Arthritis Research & Therapy, 13 (5), R145-[12pp]. (doi:10.1186/ar3459). (PMID:21914170)

Record type: Article

Abstract

Introduction: The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression.

Methods: Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1? (IL-1?), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data.

Results: CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1?. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1? (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1?, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1?-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1?-treated constructs.

Conclusions: Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1?. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old.

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Published date: 13 September 2011
Organisations: Faculty of Health Sciences

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Local EPrints ID: 347057
URI: http://eprints.soton.ac.uk/id/eprint/347057
ISSN: 1478-6354
PURE UUID: ee9af1c4-b1ed-4990-923e-916ce06a689f
ORCID for Dan L. Bader: ORCID iD orcid.org/0000-0002-1208-3507

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Date deposited: 04 Feb 2013 12:02
Last modified: 14 Mar 2024 12:44

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Contributors

Author: M. Ramachandran
Author: P. Achan
Author: D.M. Salter
Author: Dan L. Bader ORCID iD
Author: T.T. Chowdhury

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