ABSTRACT
Objective To study the effect of atmospheric particulate exposure on the expression of key molecules of Nrf2 signaling pathway involved in oxidative stress and inflammatory response factors in myocardium of rats fed with high-fat and high-glucose diet. Methods A total of 48 SD male rats were randomly divided into control group (CC group), high-fat and high-glucose diet group (HC group), atmospheric particulates group (CP group) and atmospheric particulates plus high-fat and high-glucose diet group (HP group), with 12 rats in each group.Rats were fed in individual ventilated cages (IVC).The CC and HC groups were placed in IVCs equipped with the atmospheric particulate filter, however, the CP and HP groups without the atmospheric particulate filter to make the air composition similar to the outdoor.A total of 24 rats were sacrificed for acquiring myocardial tissue after 3 and 6 months of exposure.The mRNA expression of Nrf2, HO-1, NQO1, VCAM-1 and MCP-1 were measured using RT-qPCR and the protein expression of VCAM-1, MCP-1 detected using western blot. Results The mRNA expression levels of Nrf2, HO-1, NQO1, VCAM-1 and MCP-1 and the protein expression levels of VCAM-1 and MCP-1 in HC, CP and HP groups were higher than CC group (P < 0.05).The mRNA expression levels of Nrf2, HO-1, NQO1, VCAM-1, MCP-1 and the protein expression levels of VCAM-1, MCP-1 in the HP group were higher than HC and CP groups (P < 0.05).The mRNA expression levels of Nrf2 in CP and HP groups after 6 months of exposure were lower than that at 3 months (P < 0.05). Conclusion The exposure of atmospheric particles, high-fat and high-glucose and their combination diets could cause myocardial tissue inflammatory responses, and activate Nrf2 signaling pathways to protect against myocardial damage.