摘要
Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.
Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.
基金
supported by the China Mega-project for Infectious Disease [2018ZX10102001,2018ZX10711001,2018ZX10734401,and 2018ZX10734404]
the SKLID Development Grant [2011SKLID104]
