Figure 3. PM exposure is positively correlated with activation of the SREBP1-PIR signaling pathway through SIRT1 downregulation. (A) Western blot analysis of PIR after PM treatment in HPF. (B) PIR activity from cell culture supernatant in PM-induced models. (C) Levels of SREBP1, SIRT1, and PIR were measured from cell culture supernatant of PM-induced models. (D) mRNA levels of SREBP1 in PF429242-PM co-treated HPF models. (E) mRNA levels of PIR in PF429242-PM co-treated HPF models. (F) PIR activity from cell culture supernatant in PF429242-PM co-treated HPF models. (G) Western blot analysis of PIR and SIRT1 in TPh A-PM co-treated HPF models. (H) PIR activity from cell culture supernatant in TPh A-PM co-treated HPF models. (I) mRNA level of PIR in Ex527-PM co-treated HPF models. (J) Western blot analysis of SIRT1 and PIR in Ex527-PM co-treated HPF models. (K) Level of PIR was measured from cell culture supernatant in Ex527-PM co-treated HPF models.