SUN-603 Electronic Cigarette Exposure Induces Pro-Inflammatory Changes in Adipose Tissue in Apolipoprotein E (APOE) Knockout Mice

Electronic nicotine delivery systems or electronic cigarettes (e-cigarettes) are becoming exceptionally popular in the world as an alternative to conventional nicotine cigarettes, both in smokers and people who have never smoked. Nicotine can induce lipolysis in adipose tissue, leading to increased serum free fatty acids (FFA). Increased levels of FFA are one of the key elements in inducing a pro-inflammatory response and lead to ectopic lipid accumulation, lipotoxicity, mitochondrial dysfunction and metabolic disease. Our laboratory has shown that chronic e-cigarette exposure induces cardiac dysfunction, atherosclerosis and hepatic steatosis in the ApoE knockout (KO) model associated with increased levels of serum FFA. In this study, we investigated the role of adipose tissue in the metabolic changes associated with e-cigarette exposure. ApoE KO mice were exposed to saline, e-cigarette without nicotine [e-cigarette (0%)] and e-cigarette with 2.4% nicotine [e-cigarette (2.4%)] aerosol for 12 weeks. Western blot analyses from adipose tissue showed that mice treated with e-cigarette (2.4%) had decrease levels of SIRT1 when compared to mice treated with saline or e-cigarette (0%). Transcriptomic analysis of the differentially expressed genes shows a differential transcriptional response to e-cigarette (2.4%) in adipose tissue in comparison with e-cigarette (0%) or saline. The RNA-seq examination using ingenuity pathway analysis (IPA) software, revealed dysregulation of fibrosis, agranulocyte and granulocyte adhesion and diapedesis pathways in e-cigarette (2.4%) -exposed adipose tissue. Overall, we found an inflammatory phenotype associated with decreased levels of SIRT1 in adipose tissue of mice treated with e-cigarette (2.4%). Understanding the consequences of e-cigarette use on metabolic disease is directly relevant to the development of policies related to e-cigarette use.