Anti-Toll-like receptor 2 antibody inhibits nuclear factor kappa B activation and attenuates cardiac damage in high-fat-feeding rats

Long-time consumption of high-fat food is a direct cause of cardiovascular diseases, and high-fat-related inflammation plays an important role in it. Toll-like receptors (TLRs), especially TLR2 and TLR4, play important roles in high-fat-related inflammation. However, the impact of TLR2 on high-fat-associated cardiovascular complications is still unknown. In this study, we try to investigate the relationship between TLR2 and high-fat-related cardiac injury. SD rats were allocated to either a control group which were fed with normal diet or a high-fat group which were fed with high-fat diet for 5 months. At the last month, rats fed with high-fat diet were intraperitoneally injected with control normal mouse IgG or anti-TLR2 antibody. Heart tissues were collected for further analysis. RT-qPCR and western blot analysis results revealed that TLR2 expression was increased in the heart tissues from rats fed with high-fat diet and anti-TLR2 antibody had no effect on TLR2 expression. However, anti-TLR2 antibody alleviated masson staining area, levels of TGF-β1 and Collagen I mRNA, and decreased TUNEL-positive myocardial cells and caspase-3 activity, suggesting that anti-TLR2 antibody protected cardiac cells against high-fat-induced cardiac fibrosis and cell apoptosis. By using immunohistochemistry, RT-qPCR and ELISA, we found that anti-TLR2 antibody blocked NF-κB activation, inhibited the expression of inflammatory factors such as TNF-α, IL-1β, IL-6 and IL-18 in the heart tissues from rats fed with high-fat diet. These results hinted that anti-TLR2 antibody might exert its protective effect via inhibition of the TLR2/NF-κB/inflammation pathway. Our findings suggest that anti-TLR2 antibody has a preventive function against high-fat-induced deleterious effects in the heart, and anti-TLR2 antibody may be used as an attractive therapeutic option for high-fat-induced cardiac injury.