Sestrin2 Overexpression Ameliorates Endoplasmic Reticulum Stress-Induced Apoptosis via Inhibiting mTOR Pathway in HepG2 Cells

Huiling Hu; Zhijun Luo; Xiuli Liu; Lisi Huang; Xiaoxia Lu; Rui Ding; Chaohui Duan; Yuqing He

doi:10.1155/2022/2009753

Sestrin2 Overexpression Ameliorates Endoplasmic Reticulum Stress-Induced Apoptosis via Inhibiting mTOR Pathway in HepG2 Cells

Int J Endocrinol. 2022 Dec 10:2022:2009753. doi: 10.1155/2022/2009753. eCollection 2022.

Authors

Huiling Hu^{1

2}, Zhijun Luo³, Xiuli Liu^{1

2}, Lisi Huang^{1

2}, Xiaoxia Lu^{1

2}, Rui Ding^{1

2}, Chaohui Duan^{1

2}, Yuqing He⁴

Affiliations

¹ Department of Clinical Laboratory, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
² Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
³ Department of Emergency, The Seventh Affiliated Hospital, Southern Medical University, Foshan, Guangdong 528244, China.
⁴ Translational Medicine Research Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China.

Abstract

Sestrin2 is a highly conserved stress-inducible protein, acting as a crucial part in regulating homeostasis in response to various stress conditions in the cell. However, the role of Sestrin2 in regulating cell apoptosis related to endoplasmic reticulum (ER) has not been fully investigated. Our study presented here aims to reveal the effect of Sestrin2 in tunicamycin (TM)-induced cell apoptosis related to ER stress and its underlying molecular mechanisms. The results demonstrated that Sestrin2 expression was significantly upregulated correlated with ER stress responses in TM treated HepG2 cells. Sestrin2 overexpression obviously alleviated ER stress with the determination of ER stress-related proteins expression. In addition, Sestrin2 overexpression inhibited cell apoptosis with the examination of apoptosis-related proteins and TUNEL assay. However, Sestrin2 knockdown further promoted the ER stress-mediated cell apoptosis. The further mechanistic study revealed that Sestrin2 overexpression inhibited TM-induced mTOR pathway activation. Taken together, our current study indicated that Sestrin2 overexpression ameliorates ER stress-induced apoptosis via inhibiting mTOR pathway in HepG2 cells.