High LDL levels lead to increased synovial inflammation and accelerated ectopic bone formation during experimental XXXX .

@entity6970 @entity571 @entity19 @entity164 @entity3843 @entity12100 @entity165
OBJECTIVE: A relation between @entity571 ( @entity571 ) and increased @entity165 levels is apparent. In the present study we investigate @entity571 pathology in @entity6970 ( @entity6970 )(-)(/-) @entity19 with and without a @entity165 -rich diet, a model for high systemic low density lipoprotein (LDL) @entity165 levels independent of weight. METHOD: @entity164 ( @entity164 ), @entity6970 (-)(/-), @entity3843 (-/-) and @entity6970 (-)(/-) @entity3843 (-/-) @entity19 (C57BL/6 background) received a standard or @entity165 -rich diet. Experimental @entity571 was induced by intra-articular injection of collagenase and animals were sacrificed at day 10 and day 36. RESULTS: Although minimal differences in cartilage damage were found between the @entity164 and @entity6970 (-)(/-) @entity19 , increased synovial thickening was found in the latter. Thirty-six days after @entity571 -induction, @entity6970 (-)(/-) @entity19 on a standard diet showed increased ectopic bone formation, particularly at the medial collateral ligament, compared with @entity571 in @entity164 @entity19 . Furthermore, a significant increase in synovial gene expression of both @entity12100 and @entity3843 and @entity12100 / @entity3843 protein levels was found in @entity6970 (-)(/-) @entity19 , suggesting an activated inflammatory status of synovial cells. In both @entity6970 (-)(/-) and @entity164 @entity19 , addition of a @entity165 -rich diet resulted in excessive bone formation in the medial collateral ligament at late-time-point @entity571 . Interestingly, at the early time point, proteoglycan deposition was already significantly increased in @entity6970 (-)(/-) @entity19 compared with @entity164 @entity19 . @entity19 deficient for both @entity6970 and @entity3843 also showed increased ectopic bone formation, but not synovial activation, suggesting a role for S100-proteins in @entity165 -mediated synovial activation. CONCLUSIONS: Increased @entity165 levels strongly elevate synovial activation and ectopic bone formation in early-stage collagenase-induced @entity571 .
