Effect of Aging on Adipose Tissue Inflammation in the Knee Joints of F344BN XXXX .

@entity32 @entity571 @entity39 @entity5 @entity16 @entity3426 @entity35 @entity10957
UNASSIGNED: The infrapatellar fat pad (IFP) secretes inflammatory mediators in osteoarthritic knees, but the effect of aging on IFP @entity32 is unknown. We tested the hypothesis that aging increases basal and @entity3426 ( @entity3426 )-stimulated IFP @entity32 in 10-, 20-, and 30-month-old male F344BN F1-hybrid @entity35 . IFPs were cultured ex vivo for 24 hours and treated   1ng/mL @entity3426 to simulate injury-induced @entity32 . IFP @entity32 was evaluated by measuring secreted cytokine concentrations and by quantitative expression of immunoregulatory and pro- and anti-adipogenic genes. With age, @entity571 pathology increased and IFP mass decreased. Although adipocyte size did not change with age, variation in adipocyte size was positively associated with synovial thickness independent of age whereas associations with @entity16 were age dependent. In the absence of @entity3426 , aging was associated with a significant increase in IFP secretion of @entity5 @entity39 factor a by 67% and @entity10957 by 35% and a reduction in the expression of immunoregulatory M2 macrophage genes. However, following an @entity3426 challenge, adipogenesis markers decreased and pro- and anti-inflammatory cytokines increased independent of age. The lone exception was leptin, which decreased >70% with age. Thus, although aging promotes @entity571 risk by increasing basal @entity32 , our findings also revealed a potentially protective effect of aging by decreasing @entity3426 -stimulated leptin production.
