PPARGC1A and chronic obstructive pulmonary disease: As seen in Figure 11, animals in the CS + LPS-exposed COPD group displayed downregulation of NRF2, PGC1α, SOD1, and SOD2 (p < 0.01, p < 0.001), and CYP2A13 levels were increased in the COPD group compared to the Control group (p < 0.01).