High Fat, High Sugar Diet Induces Metabolic Changes in Articular Cartilage that are Reversed with Low Intensity Exercise and Genistein Treatment

Abstract

High fat, high‐sugar diet (HSFD) has been shown to induce obesity, metabolic dysregulation, and inflammation in peripheral tissues. Inflammation within cartilage tissue is associated with metabolic changes that lead to arthrosis. In this study, we examine the effects of HSFD on expression of col10a and MMP‐13 in articular cartilage of the knee joint. Both of these proteins are markers for inflammation in chondral tissue. In the presence of proinflammatory cytokines, col10a expression by chondrocytes decreases, while MMP‐13 increases. We also examined the effects of low intensity exercise and genistein treatment on cartilage metabolism. Both of these treatments have been shown to improve bone health, but their effects on diet‐induced cartilage inflammation are unclear. We randomly assigned 100 mice to five treatment groups of equal sizes: lean controls, HFSD fed, HFSD + exercise, HFSD + genistein, and HFSD + exercise + genistein. HFSD included 60% fat in chow and 42 g/L sugar in the drinking water. Exercise training included treadmill running for 180 min/week. Genistein was given in the diet at 600 mg/kg. Duration of treatment was 12 weeks. Col10a expression was significantly reduced in mice fed HFSD versus lean controls (P < 0.05). Mice treated with exercise and genistein in combination exhibited decreased col10a expression that was similar to levels expressed in cartilage of lean controls. MMP‐13 expression did not differ significantly among the treatment groups (P > 0.05). Examination of articular cartilage stained with H&E revealed the thickness of the uncalcified zones was significantly reduced in mice fed HFSD in comparison to lean control mice (P < 0.05). Staining in this zone also reflected reduced proteoglycan content in the cartilage of mice in the HFSD treatment group. These findings suggest articular cartilage of mice fed HFSD exhibit signs of inflammation and reduced capacity to resist compression. Treatment with genistein and exercise in combination resulted in articular cartilage that more closely resembles cartilage of lean mice fed a standard diet. Low‐intensity exercise and genistein intake may prove beneficial to joint health in the obese condition.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.