title: Modulation of proteoglycan production by cyclic tensile stretch in intervertebral disc cells through a post-translational mechanism.
abstract: Proteoglycan production is one of the major extracellular matrix components implicated in the dynamic process of intervertebral disc degeneration. Mechanical stress is an important modulator of the degeneration, but the underlying molecular mechanism at the proteoglycan level remains unclear. The aim of this work was to study the regulation of proteoglycan production by cyclic tensile stretch applied to intervertebral disc annulus fibrosus cells. Matrix metalloproteinases do not seem to be implicated in the regulation of proteoglycan production. By contrast, nitrite oxide production is induced by cyclic tensile stretch, in a time, intensity, and frequency dependant manner. Using a non-specific nitric oxide synthases inhibitor [NG-methyl-L-arginine (L-NMA)], we suppress totally the inhibition of proteoglycan production induced by cyclic tensile stretch suggesting the implication of nitric oxide synthases in the observed phenomenon. Introducing the transcriptional inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole or a more specific inhibitor of nitric oxide synthases II [N-iminoethyl-L-lysine (L-NIL)] did not affect the decreased proteoglycan production, which suggests a post-translational regulation. In contrast, N-omega nitro-L-arginine (L-NNA) a more specific inhibitor of NOS I and III abrogated the cyclic tensile stretch-dependant inhibition of proteoglycan production. These results suggest that cyclic tensile stretch regulates proteoglycan production through a post-translational mechanism involving nitrite oxide. This result could be of interest in the development of local therapeutic strategies aimed at controlling intervertebral disc degeneration.
authors.affiliation: Institut National de la Santé Et de la Recherche Médicale (INSERM) UMR-S-747, Université Paris 5, UFR Biomédicale, 45 Rue des Saints-Pères, 75006 Paris, France.
authors.forename: Mourad
authors.initials: M
authors.lastname: Benallaoua
authors.forename: Pascal
authors.initials: P
authors.lastname: Richette
authors.forename: Mathias
authors.initials: M
authors.lastname: François
authors.forename: Lydia
authors.initials: L
authors.lastname: Tsagris
authors.forename: Michel
authors.initials: M
authors.lastname: Revel
authors.forename: Maité
authors.initials: M
authors.lastname: Corvol
authors.forename: Serge
authors.initials: S
authors.lastname: Poiraudeau
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Savouret
authors.forename: François
authors.initials: F
authors.lastname: Rannou
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism / Q000502:physiology; D007403:Intervertebral Disc / Q000166:cytology / Q000378:metabolism*; D020782:Matrix Metalloproteinases / Q000378:metabolism; D040542:Mechanotransduction, Cellular / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000502:physiology; D009573:Nitrites / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011509:Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D011817:Rabbits; D013314:Stress, Mechanical
chemical_list: D009573:Nitrites; D011509:Proteoglycans; D019001:Nitric Oxide Synthase; D020782:Matrix Metalloproteinases