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Inhibition of transforming growth factor beta production by nitric oxide-treated chondrocytes: implications for matrix synthesis.
Arthritis Rheum. 1999 Feb; 42(2):248-57.AR

Abstract

OBJECTIVE

Nitric oxide (NO) is generated copiously by articular chondrocytes activated by interleukin-1beta (IL-1beta). If NO production is blocked, much of the IL-1beta inhibition of proteoglycan synthesis is prevented. We tested the hypothesis that this inhibitory effect of NO on proteoglycan synthesis is secondary to changes in chondrocyte transforming growth factor beta (TGFbeta).

METHODS

Monolayer, primary cultures of lapine articular chondrocytes and cartilage slices were studied. NO production was determined as nitrite accumulation in the medium. TGFbeta bioactivity in chondrocyte- and cartilage-conditioned medium (CM) was measured with the mink lung epithelial cell bioassay. Proteoglycan synthesis was measured as the incorporation of 35S-sodium sulfate into macromolecules separated from unincorporated label by gel filtration on PD-10 columns.

RESULTS

IL-1beta increased active TGFbeta in chondrocyte CM by 12 hours; by 24 hours, significant increases in both active and latent TGFbeta were detectable. NG-monomethyl-L-arginine (L-NMA) potentiated the increase in total TGFbeta without affecting the early TGFbeta activation. IL-1beta stimulated a NO-independent, transient increase in TGFbeta3 at 24 hours; however, TGFbeta1 was not changed. When NO synthesis was inhibited with L-NMA, IL-1beta increased CM concentrations of TGFbeta1 from 24-72 hours of culture. L-arginine (10 mM) reversed the inhibitory effect of L-NMA on NO production and blocked the increases in TGFbeta1. Anti-TGFbeta1 antibody prevented the restoration of proteoglycan synthesis by chondrocytes exposed to IL-1beta + L-NMA, confirming that NO inhibition of TGFbeta1 in IL-1beta-treated chondrocytes effected, in part, the decreased proteoglycan synthesis. Furthermore, the increase in TGFbeta and proteoglycan synthesis seen with L-NMA was reversed by the NO donor S-nitroso-N-acetylpenicillamide. Similar results were seen with cartilage slices in organ culture. The autocrine increase in CM TGFbeta1 levels following prior exposure to TGFbeta1 was also blocked by NO.

CONCLUSION

NO can modulate proteoglycan synthesis indirectly by decreasing the production of TGFbeta1 by chondrocytes exposed to IL-1beta. It prevents autocrine-stimulated increases in TGFbeta1, thus potentially diminishing the anabolic effects of this cytokine in chondrocytes.

Authors+Show Affiliations

Ferguson Laboratory for Orthopaedic Research and the University of Pittsburgh School of Medicine, Pennsylvania 15213, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10025918

Citation

Studer, R K., et al. "Inhibition of Transforming Growth Factor Beta Production By Nitric Oxide-treated Chondrocytes: Implications for Matrix Synthesis." Arthritis and Rheumatism, vol. 42, no. 2, 1999, pp. 248-57.
Studer RK, Georgescu HI, Miller LA, et al. Inhibition of transforming growth factor beta production by nitric oxide-treated chondrocytes: implications for matrix synthesis. Arthritis Rheum. 1999;42(2):248-57.
Studer, R. K., Georgescu, H. I., Miller, L. A., & Evans, C. H. (1999). Inhibition of transforming growth factor beta production by nitric oxide-treated chondrocytes: implications for matrix synthesis. Arthritis and Rheumatism, 42(2), 248-57.
Studer RK, et al. Inhibition of Transforming Growth Factor Beta Production By Nitric Oxide-treated Chondrocytes: Implications for Matrix Synthesis. Arthritis Rheum. 1999;42(2):248-57. PubMed PMID: 10025918.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Inhibition of transforming growth factor beta production by nitric oxide-treated chondrocytes: implications for matrix synthesis. AU - Studer,R K, AU - Georgescu,H I, AU - Miller,L A, AU - Evans,C H, PY - 1999/2/20/pubmed PY - 1999/2/20/medline PY - 1999/2/20/entrez SP - 248 EP - 57 JF - Arthritis and rheumatism JO - Arthritis Rheum. VL - 42 IS - 2 N2 - OBJECTIVE: Nitric oxide (NO) is generated copiously by articular chondrocytes activated by interleukin-1beta (IL-1beta). If NO production is blocked, much of the IL-1beta inhibition of proteoglycan synthesis is prevented. We tested the hypothesis that this inhibitory effect of NO on proteoglycan synthesis is secondary to changes in chondrocyte transforming growth factor beta (TGFbeta). METHODS: Monolayer, primary cultures of lapine articular chondrocytes and cartilage slices were studied. NO production was determined as nitrite accumulation in the medium. TGFbeta bioactivity in chondrocyte- and cartilage-conditioned medium (CM) was measured with the mink lung epithelial cell bioassay. Proteoglycan synthesis was measured as the incorporation of 35S-sodium sulfate into macromolecules separated from unincorporated label by gel filtration on PD-10 columns. RESULTS: IL-1beta increased active TGFbeta in chondrocyte CM by 12 hours; by 24 hours, significant increases in both active and latent TGFbeta were detectable. NG-monomethyl-L-arginine (L-NMA) potentiated the increase in total TGFbeta without affecting the early TGFbeta activation. IL-1beta stimulated a NO-independent, transient increase in TGFbeta3 at 24 hours; however, TGFbeta1 was not changed. When NO synthesis was inhibited with L-NMA, IL-1beta increased CM concentrations of TGFbeta1 from 24-72 hours of culture. L-arginine (10 mM) reversed the inhibitory effect of L-NMA on NO production and blocked the increases in TGFbeta1. Anti-TGFbeta1 antibody prevented the restoration of proteoglycan synthesis by chondrocytes exposed to IL-1beta + L-NMA, confirming that NO inhibition of TGFbeta1 in IL-1beta-treated chondrocytes effected, in part, the decreased proteoglycan synthesis. Furthermore, the increase in TGFbeta and proteoglycan synthesis seen with L-NMA was reversed by the NO donor S-nitroso-N-acetylpenicillamide. Similar results were seen with cartilage slices in organ culture. The autocrine increase in CM TGFbeta1 levels following prior exposure to TGFbeta1 was also blocked by NO. CONCLUSION: NO can modulate proteoglycan synthesis indirectly by decreasing the production of TGFbeta1 by chondrocytes exposed to IL-1beta. It prevents autocrine-stimulated increases in TGFbeta1, thus potentially diminishing the anabolic effects of this cytokine in chondrocytes. SN - 0004-3591 UR - https://www.unboundmedicine.com/medline/citation/10025918/Inhibition_of_transforming_growth_factor_beta_production_by_nitric_oxide_treated_chondrocytes:_implications_for_matrix_synthesis_ L2 - https://doi.org/10.1002/1529-0131(199902)42:2<248::AID-ANR6>3.0.CO;2-S DB - PRIME DP - Unbound Medicine ER -