scholarly journals Erratum to “Epithelial Cells Attenuate Toll-Like Receptor-Mediated Inflammatory Responses in Monocyte-Derived Macrophage-Like Cells to Mycobacterium tuberculosis by Modulating the PI3K/Akt/mTOR Signaling Pathway”

2021 ◽  
Vol 2021 ◽  
pp. 1-3
Author(s):  
Yi Yang ◽  
Yingfei Sun ◽  
Jinrui Xu ◽  
Kangda Bao ◽  
Meihui Luo ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Yi Yang ◽  
Yingfei Sun ◽  
Jinrui Xu ◽  
Kangda Bao ◽  
Meihui Luo ◽  
...  

Both alveolar macrophages (AMs) and alveolar epithelial cells (AECs) are main targets of Mycobacterium tuberculosis (M. tuberculosis (Mtb)). Intercellular communications between mucosal AECs and AMs have important implications in cellular responses to exogenous insults. However, molecular mechanisms underpinning interactions responding to Mtb remain largely unknown. In this study, impacts of AECs on Toll-like receptor- (TLR-) mediated inflammatory responses of AMs to Mtb virulent strain H37Rv were interrogated using an air-liquid interface (ALI) coculture model of epithelial A549 cells and U937 monocyte-derived macrophage-like cells. Results showed that Mtb-activated TLR-mediated inflammatory responses in U937 cells were significantly alleviated when A549 cells were coinfected with H37Rv, in comparison with the infection of U937 cells alone. Mechanistically, PI3K/Akt/mTOR signaling was involved in the epithelial cell-modulated Mtb-activated TLR signaling. The epithelial cell-attenuated TLR signaling in U937s could be reversed by PI3K inhibitor LY294002 and mTOR inhibitor rapamycin, but not glycogen synthase kinase 3β inhibitor LiCl, suggesting that the epithelially modulated-TLR signaling in macrophages was in part caused by inhibiting the TLR-triggered PI3K/Akt/mTOR signaling pathway. Together, this study demonstrates that mucosal AEC-derived signals play an important role in modulating inflammatory responses of AMs to Mtb, which thus also offers an insight into cellular communications between AECs and AMs to Mtb infections.


2017 ◽  
Vol 242 (10) ◽  
pp. 1025-1033 ◽  
Author(s):  
Weilong Chang ◽  
Jie Bai ◽  
Shaobo Tian ◽  
Muyuan Ma ◽  
Wei Li ◽  
...  

Alcohol abuse is an important cause of gastric mucosal epithelial cell injury and gastric ulcers. A number of studies have demonstrated that autophagy, an evolutionarily conserved cellular mechanism, has a protective effect on cell survival. However, it is not known whether autophagy can protect gastric mucosal epithelial cells against the toxic effects of ethanol. In the present study, gastric mucosal epithelial cells (GES-1 cells) and Wistar rats were treated with ethanol to detect the adaptive response of autophagy. Our results demonstrated that ethanol exposure induced gastric mucosal epithelial cell damage, which was accompanied by the downregulation of mTOR signaling pathway and activation of autophagy. Suppression of autophagy with pharmacological agents resulted in a significant increase of GES-1 cell apoptosis and gastric mucosa injury, suggesting that autophagy could protect cells from ethanol toxicity. Furthermore, we evaluated the cellular oxidative stress response following ethanol treatment and found that autophagy induced by ethanol inhibited generation of reactive oxygen species and degradation of antioxidant and lipid peroxidation. In conclusion, these findings provide evidence that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate oxidative damage induced by ethanol in gastric mucosal epithelial cells. Therefore, modifying autophagy may provide a therapeutic strategy against alcoholic gastric mucosa injury. Impact statement The effect and mechanism of autophagy on ethanol-induced cell damage remain controversial. In this manuscript, we report the results of our study demonstrating that autophagy can protect gastric mucosal epithelial cells against ethanol toxicity in vitro and in vivo. We have shown that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate ethanol-induced oxidative damage in gastric mucosal epithelial cells. This study brings new and important insights into the mechanism of alcoholic gastric mucosal injury and may provide an avenue for future therapeutic strategies.


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