Association of EGF Receptor and NLRs signaling with Cardiac Inflammation and Fibrosis in Mice Exposed to Fine Particulate Matter

?Ambient fine particulate matter (PM2.5) could induce cardiovascular diseases (CVD), but the mechanism remains unknown. To investigate the roles of epidermal growth factor receptor (EGFR) and NOD-like receptors (NLRs) in PM2.5-induced cardiac injury, we set up a BALB/c mice model of PM2.5-induced cardiac inflammation and fibrosis with intratracheal instillation of PM2.5 suspension (4.0mg/kg b.w.) for 5 consecutive days (once per day). After exposure, we found that mRNA levels of CXCL1, interleukin (IL)-6, and IL-18 were elevated, but interestingly, mRNA level of NLRP12 was significant decreased in heart tissue from PM2.5-induced mice compared with those of saline-treated mice using real-time PCR. Protein levels of phospho-EGFR (Tyr1068), phospho-Akt (Thr308), NLRP3, NF-B-p52/p100, and NF-B-p65 in heart tissue of PM2.5-exposed mice were all significantly increased using immunohistochemistry or Western blotting. Therefore, PM2.5 exposure could induce cardiac inflammatory injury in mice, which may be involved with EGFR/Akt signaling, NLRP3, and NLRP12. (C) 2016 Wiley Periodicals, Inc.