biostudies-literatureUnknown17(11)Jin J<h4>Background</h4>Cigarette smoke extract (CSE) induces reactive oxygen species (ROS) generation in human bronchial epithelial cells, leading to mitochondrial dysfunction and subsequently triggering the mitochondrial unfolded protein response (UPR^mt) mediated by the bZIP transcription factor activating transcription factor 4 (ATF-4). This study aimed to investigate whether UPR^mt and ATF-4 are involved in the pathway of mitochondrial function impairment in BEAS-2B cells caused by CSE.<h4>Methods</h4>BEAS-2B bronchial epithelial cells were treated with different concentrations of CSE, and mitochondrial function was detected by JC-1 staining and MitoSoxRed staining. The expression and localisation of translocase of inner mitochondrial membrane 23 (Tim23) and ATF-4 were Journal of thoracic disease9586-9597https://www.ebi.ac.uk/biostudies/studies/S-EPMC12688523biostudies-literatureInvolvement of mitochondrial unfolded protein response and activating transcription factor 4 in the mitochondrial damage pathway of BEAS-2B cells induced by cigarette smoke extracts.PMC12688523Wang SHuang MMa HXu FLv DDing QJin JFu PCen TFei LfalseInvolvement of mitochondrial unfolded protein response and activating transcription factor 4 in the mitochondrial damage pathway of BEAS-2B cells induced by cigarette smoke extracts.<h4>Background</h4>Cigarette smoke extract (CSE) induces reactive oxygen species (ROS) generation in human bronchial epithelial cells, leading to mitochondrial dysfunction and subsequently triggering the mitochondrial unfolded protein response (UPR^mt) mediated by the bZIP transcription factor activating transcription factor 4 (ATF-4). This study aimed to investigate whether UPR^mt and ATF-4 are involved in the pathway of mitochondrial function impairment in BEAS-2B cells caused by CSE.<h4>Methods</h4>BEAS-2B bronchial epithelial cells were treated with different concentrations of CSE, and mitochondrial function was detected by JC-1 staining and MitoSoxRed staining. The expression and localisation of translocase of inner mitochondrial membrane 23 (Tim23) and ATF-4 were 2025-01-01T00:00:00Z2025 Nov2026-06-06T00:33:57.023Z2026-05-24T03:11:56.181ZS-EPMC126885234137697110.21037/jtd-2025-460