Fig. 4.

Gene expression of DNA methyltransferases, histone deacetylases, histone acetyltransferases, histone methyltransferases, histone phosphorylation, and histone ubiquitination in acute and chronic air- vs. CS-exposed mouse lungs. C57BL6/J mice were exposed to acute (3 days) and chronic (6 mo) air or CS. RNA extracted from air- and CS-exposed mice were analyzed using qPCR primers for specific mouse epigenetic chromatin modification enzymes. A: the transcription levels of genes encoding specific DNMTs (Dnmt1, Dnmt3a, and Dnmt3b), HDACs (Hdac2 and Hdac4), and HATs (Hat1 and Ncoa3) were examined by qPCR using the 2^−ΔΔCt method. B: the transcription levels of genes encoding specific HMTs (Prmt1, Prmt5, Prmt8, and Nsd1), histone phosphorylation (Aurkc), and ubiquitination (Usp22) were examined by qPCR using the 2^−ΔΔCt method. Bar graphs represent the mean normalized expression of samples in air group vs. CS-exposed mouse lung. Data were normalized using the endogenous housekeeping gene 18S rRNA as reference and air group control as calibrators. Statistical significance (P < 0.05) was analyzed by two-way ANOVA (Tukey's multiple-comparison test) using GraphPad Prism 6. Values are means ± SE (n = 4–6/group). *P < 0.05 and ***P < 0.001 vs. air. #P < 0.05, ##P < 0.01, and ###P < 0.001 vs. CS (3 days).