Objective To examine the effect of voluntary wheel-running exercise on cartilage morphology of knee osteoarthritis(KOA) in obese mice induced by high-fat diet,and explore the protective role of 4 weeks voluntary wheel-running exercise on KOA,finally providing effective experimental evidence for clinical treatment of knee osteoarthritis.
Methods C57BL/6J mice were randomly assigned to the C-Sed group,C-Ex group,HF-Sed group and HF-Ex group.The control groups were fed a control diet(13.5% kcal from fat),and the high-fat groups were fed a high-fat diet(60% kcal from fat).After feeding 8 weeks different diets,the exercise groups were starting running.In order to examine the effect of voluntary wheel-running exercise on cartilage morphology of KOA,the joint of knee were harvested to be fixed,decalcified and embedded in paraffin,and the four-micrometer-thick sections were stained with both HE and toluidine blue .
Results After feeding twelve weeks different diets,the body mass of the high-fat diet group mice has a significant increase,which demonstrates that high-fat diet could successfully induce the mice obese.From the results of HE and toluidine blue,in comparison to the C-Sed group,the surface of the knee articular cartilage in the HF-Sed group was not intact and smooth,and the thickness of articular cartilage has a significant decrease（p<0.001）;contrary to the HF-Sed group,the surface of the knee articular cartilage in HF-Ex group was slightly smooth,and there was significant increase in cartilage thickness.
Conclusions Four weeks voluntary wheel-running exercise can increase cartilage thickness ,decrease the Mankin’s score and delay the degeneration of knee cartilage in obese mice.To conclude,the short-term wheel-running exercise protects against obesity-induced KOA.
Effects of a High Fat Diet and Voluntary Wheel Running Exercise on Cidea and Cidec Expression in Liver and Adipose Tissue of Mice
