Objective To explore the regulation of peroxisome proliferator-activated receptor γ coactivator 1α( PGC-1α) and NF-E2-related factor 2( Nrf2) on expression of γ-glutamylcysteine synthetase ( γ-GCS) , and their roles in chronic obstructive pulmonary disease( COPD) . Methods Twenty-four SD rats were randomly divided into a COPD group and a normal control group. COPD model was established by intratracheal instillation of lipopolysaccharide ( LPS) and daily exposure to cigarette smog in the COPD group. The lung function was measured and the pathological changes were observed. The protein and mRNA expressions of PGC-1α, Nrf2, and γ-GCS in lung tissue were measured by immunohistochemistry, Western blot, in site hybridization ( ISH) , and reverse transcription-polymerase chain reaction ( RT-PCR ) ,respectively. Results In the COPD group, the pulmonary function ( FEV0. 3, FEV0. 3 /FVC, PEF) damage and lung pathological changes were conformed as morphological characteristics of COPD. The mRNA of PGC-1α and Nrf2 expressed in lung tissues of two group rats in the region consistent with γ-GCS mRNA. The protein and mRNA expressions of PGC-1αand γ-GCS were markedly increased in the COPD group( all P lt;0. 05) ,and the protein expression of Nrf2 was obviously up-regulated ( P lt; 0. 01) , while Nrf2 mRNA had no significant difference between the two groups( P gt;0. 05 ) . Linear correlation analysis showed that the level ofPGC-1αprotein was positively correlated with the levels of Nrf2 protein and mRNA ( r = 0. 775, 0. 515, all P lt; 0. 01) , and the levels of PGC-1αand Nrf2 protein were positively correlated with the levels of γ-GCS protein ( r = 0. 531, 0. 575, all P lt; 0. 01) and mRNA ( r = 0. 616, 0. 634, all P lt; 0. 01) . Conclusions PGC-1α, which may serve as a co-activator of Nrf2, can up-regulate the expression of γ-GCS gene cooperatively with Nrf2 through a common pathway, which might involve in the oxidative and antioxidative mechanism in the pathogenesis of COPD.
