Shengmai Yin Alleviates Particulate Matter‐Aggravated Ischemic Damage by Inhibiting S100a9 Expression

The issue of air pollution has had a longstanding impact on human health, specifically on the exacerbation of ischemic cardiomyopathy injury and hindered healing due to the presence of fine airborne particles. Shengmai Yin, a traditional Chinese medicine, has been used to treat coronary heart disease. In the present study, we identified a significant association among the genes S100a8, S100a9, Nppa, Nppb, and Serpine1 and myocardial ischemic injury aggravated by exposure to particulate matter (PM) using transcriptome and proteome analyses. In addition, we substantiated the involvement of S100a9 in the pathological association between myocardial ischemic injury and aggravation caused by PM exposure. We validated this finding by constructing a mouse model of myocardial ischemia exacerbated by PM exposure. Mice exposed to PM exhibited significant upregulation of S100a9 and S100a8 expressions, significantly increased myocardial injury, further upregulation of IL-6 and Ccl2 levels, and significantly increased neutrophil infiltration following myocardial ischemia. Immunofluorescence staining revealed that S100a9 originated from infiltrating neutrophils. Administration of Shengmai Yin significantly alleviated myocardial injury, decreased the levels of the inflammatory factors IL-1β and IL-6, and reduced neutrophil infiltration. These results suggest that S100a9 is one of the key molecules in the exacerbation of myocardial ischemic injury caused by PM exposure, and Shengmai Yin acts against PM-aggravated myocardial ischemic injury by reducing S100a9 levels.