[The pathway of PI3k/Akt-aPKCiota/zeta-Nrf2 regulating the expression of gamma-glutamylcysteine synthetase in the bronchial epithelial cells of rats].

Objective: To observe the effect of the signal pathway of phosphoinositol-3-kinase (PI3K)/Akt-antypical protein kinase C(iotazeta) (aPKC(iotazeta))-Nuclear factor-E2 related factor (Nrf2) on gamma-glutamylcysteine synthetase (gamma-GCS) of the bronchial epithelial cells of rats after exposure to cigarette smoke extracts (CSE).

Methods: gamma-GCS, Nrf2, p-Akt and p-aPKC(iotazeta) proteins were semi-quantified by Western blot. gamma-GCS protein expression was assessed by immunocytochemistry. gamma-GCS mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). Nrf2 protein was observed by immunofluorescence. The rate of the cells expressed p-Akt were analyzed by flow cytometry. GSH content and gamma-GCS activity were measured.

Results: GSH content, Nrf2 protein of nucleus, p-aPKC(iotazeta) protein, p-Akt protein and positive cells, gamma-GCS protein and mRNA and activity were significantly increased after exposure to CSE for 3 hours. aPK(iotazeta) inhibitor RO813220 significantly reduced the expression of p-aPKC(iotazeta) protein, gamma-GCS protein and mRNA and activity, but enhanced Nrf2 protein of cytoplasm expression, had no effect on p-Akt. p-Akt inhibitor LY294002 and RO813220 + LY294002 decreased p-aPKC(iotazeta) protein, p-Akt protein and positive cells, gamma-GCS protein and mRNA and activity expression, increased Nrf2 protein of cytoplasm expression. The correlation analysises demonstrated that there were a positive correlation between Nrf2 and gamma-GCS, p-Akt, p-aPKC(iotazeta), between p-Akt and Nrf2, p-aPKC(iotazeta), gamma-GCS, between p-aPKC(iotazeta) and Nrf2, p-Akt, gamma-GCS.

Conclusion: CSE might upregulate gamma-GCS expression through PI3K/Akt-aPKC(iotazeta)-Nrf2 signaling pathway in the bronchial epithelial cells of rats.