Skip to main content
. Author manuscript; available in PMC: 2016 Dec 1.
Published in final edited form as: J Hepatol. 2015 Jul 26;63(6):1397–1404. doi: 10.1016/j.jhep.2015.07.020

Figure 3. PM2.5 exposure down-regulates expression of PPARγ in HSC.

Figure 3

(A) Quantitative real-time PCR analysis of expression levels of PPARγ1 mRNA in LX-2 cells cultured in the conditioned medium from RAW264.7 cells exposed to PM2.5 for 12 or 24 hours. Fold changes of mRNA are shown by comparing to the vehicle control. Each bar denotes the mean ± SEM (n=3 biological replicates). (B) Immunoblotting analysis of PPARγ levels in LX-2 cells cultured in the conditioned media from RAW264.7 cells exposed to PM2.5 for 12 or 24 hours. LX-2 cells were incubated with the conditioned medium for 36 hours before subjected to immunoblotting analysis. LX-2 cells were cultured in the conditioned medium from RAW264.7 cells exposed to PBS for 24 hours as the control. The graph beside the images shows fold changes of PPARγ protein levels in LX-2 cells. The fold changes of PPARγ in PM2.5-exposed LX2 cells were determined by normalizing to the PPARγ signal intensities in PM2.5-exposed LX2 cells to that of vehicle-exposed LX2 cells. (C–E) Pre-treatment of Pioglitazone (Pio) prevents PM2.5-induced down-regulation of PPARγ in HSC. LX2 cells were cultured in the presence of Pio at the concentration of 1 or 2.5 µM for 48 hours before they were incubated with the conditioned medium from RAW264.7 cell exposed to PM2.5 (50µg/ml) for 14 hours. LX2 were incubated with the conditioned medium for 36 hours in the presence of Pio, and then subjected to extraction of RNAs and proteins for qRT-PCR analyses of PPARγ1 and PPARγ2 mRNA levels (C–D) and Western blot analysis of PPARγ protein levels (E). LX2 cells treated with vehicles (DMSO, the vehicle for Pio treatment; and PBS, the vehicle for PM2.5). The fold changes of PPARγ mRNA levels in PM2.5- and/or Pio-treated cells were determined by normalizing to PPARγ levels in vehicle-treated cells. Each bar denotes the mean ± SEM (n=3 biological replicates). The graph beside the images (panel E) showed fold changes of PPARγ levels in LX-2 cells. The fold changes of PPARγ in the Pio-treated LX2 cells were determined by comparing the normalized PPARγ signal intensities in the Pio-treated LX2 cells to that in the vehicle-treated LX2 cells (100%). * P≤ 0.05, ** P≤ 0.01.