N-acetylcysteine Attenuates Cigarette Smoke-induced Alveolar Epithelial Cell Apoptosis through Reactive Oxygen Species Depletion and Glutathione Replenish In vivo and In vitro

Jie Zhao; Mi Han; Yange Tian; Peng Zhao; Xuefang Liu; Haoran Dong; Suxiang Feng; Jiansheng Li

doi:10.2174/0113892010257526231019143524

N-acetylcysteine Attenuates Cigarette Smoke-induced Alveolar Epithelial Cell Apoptosis through Reactive Oxygen Species Depletion and Glutathione Replenish In vivo and In vitro

Curr Pharm Biotechnol. 2023 Oct 31. doi: 10.2174/0113892010257526231019143524. Online ahead of print.

Authors

Jie Zhao^{1

2}, Mi Han^{1

2}, Yange Tian^{1

2}, Peng Zhao^{1

2}, Xuefang Liu^{1

2}, Haoran Dong^{1

2}, Suxiang Feng¹, Jiansheng Li²

Affiliations

¹ Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, China.
² Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases co-constructed by Henan Province & Education Ministry of P.R. China, Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, 450000, China.

PMID: 37921125
DOI: 10.2174/0113892010257526231019143524

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. N-acetylcysteine (NAC) is well known for its antioxidant properties, along with potential protective effects on COPD. However, the molecular mechanism of NAC against the apoptosis of alveolar epithelial cells (AECs) in COPD remains unclear.

Objective: This study aimed to explore the anti-apoptosis effect of NAC in COPD mice and alveolar epithelial cells.

Methods: In the present study, the mouse model of COPD was established by cigarette smoke (CS), and mouse alveolar epithelial (MLE-12) cells were treated with cigarette smoke extract (CSE). TdT-mediated dUTP nick-end labeling (TUNEL) assay, reverse transcription polymerase chain reaction (RT-PCR), and western blot were performed to evaluate the effects of NAC on apoptosis, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Meanwhile, LButhionine- sulfoximine (BSO), a glutathione (GSH) inhibitor, was used to uncover the mechanism of COPD treatment by NAC.

Results: We found that NAC pretreatment could attenuate the protein levels of apoptosis, ER stress, and mitochondrial dysfunction-related genes caused by CS in vivo. Meanwhile, CSE could decrease MLE-12 cell viability, which was prevented by apoptosis inhibitor ZVAD-FMK but not necroptosis inhibitor necrostatin-1. Pretreatment of MLE-12 cells with NAC increased cellular GSH levels, inhibited cellular and mitochondrial reactive oxygen species (ROS) accumulation, and decreased protein level of apoptosis, ER stress, and mitochondrial dysfunctionrelated genes. Moreover, experiment results showed that BSO could completely reverse the beneficial effects of NAC.

Conclusion: Our study confirmed that NAC can attenuate CS-induced AEC apoptosis via alleviating ROS-mediated ER stress and mitochondrial dysfunction pathway, and the mechanism was found to be related to replenishing the cellular GSH content.

Keywords: COPD; N-acetylcysteine; alveolar epithelial cell; apoptosis; glutathione; glutathioneN-acetylcysteine; reactive oxygen species.