Dual effects of 17beta-oestradiol on interleukin 1beta-induced proteoglycan degradation in chondrocytes.
OBJECTIVE
To determine whether 17beta-oestradiol (E2) modulates interleukin (IL) 1beta-induced proteoglycan degradation in chondrocytes, and to analyse the part played by metalloproteinases (MMPs) in this process.


METHODS
Primary cultured rabbit articular chondrocytes were prepared and treated with 10 ng/ml IL1beta combined or not with 0.1-10 nM E2. Neosynthesised proteoglycans (PGs) were evaluated after incorporation of [(35)SO(4)]sulphate and further analysed after chromatography on a Sepharose 2B column. Chondrocyte mRNA levels of aggrecan, MMP-1, -3, -13, and tissue inhibitor of metalloproteinase-1 (TIMP-1) were studied by northern blot. MMP-1 activity was measured by zymography. MMP-1 gene transcription was studied by transient transfection of chondrocytes with an MMP-1-luciferase construct.


RESULTS
E2 modulated the IL1beta-induced total sulphated PGs in rabbit articular chondrocytes, which decreased as the E2 concentration was increased. At a low concentration (0.1 nmol/l) E2 counteracts the IL1beta-induced decrease in sulphated PG, while at high concentration (10 nmol/l) E2 enhances the IL1beta effects. A biphasic E2 effect was also observed on IL1beta-induced disaggregation of PG, 53-58 kDa gelatinolytic activity, and MMP-1, -3, and -13 mRNA levels. In contrast, E2 did not modify the level of aggrecan mRNA and had no effect on TIMP-1 mRNA expression. Finally, simultaneous addition of IL1beta and E2 (0.1-10 nmol/l) did not modify IL1beta-induced MMP-1-luciferase activity, suggesting that E2 effects probably occur at the post-transcriptional level of MMP gene expression.


CONCLUSIONS
Oestrogen concentration may have an inverse effect on IL1beta stimulated proteoglycan degradation and MMP production by chondrocytes.
Richette
P
P
UMR-S U530 INSERM-Université Paris 5, UFR Biomédicale, 45 rue des Saints Pères, 75270 Paris, Cedex 06, France. pascal.richette@lrb.ap-hop-paris.fr
Dumontier
M F
MF
François
M
M
Tsagris
L
L
Korwin-Zmijowska
C
C
Rannou
F
F
Corvol
M T
MT
D053674:Aggrecans; D000818:Animals; D019902:Chondrocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D017364:Collagenases / Q000235:genetics; D003864:Depression, Chemical; D004958:Estradiol / Q000494:pharmacology*; D016326:Extracellular Matrix Proteins; D015870:Gene Expression; D007375:Interleukin-1 / Q000494:pharmacology*; D037181:Lectins, C-Type; D020781:Matrix Metalloproteinase 1 / Q000235:genetics; D053509:Matrix Metalloproteinase 13; D019278:Matrix Metalloproteinase 3 / Q000235:genetics; D010003:Osteoarthritis / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics
D053674:Aggrecans; D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D037181:Lectins, C-Type; D011509:Proteoglycans; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D004958:Estradiol; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1