ABSTRACT
In the present study we investigated the changes in miRNA levels inhuman rhinovirus 16 (HRV16)-infected cells. A small RNA deep sequencing experiment was performed through next-generation sequencing. In total, 53 differentially expressed miRNAs were confirmed by RT-qPCR, including 37 known miRNAs and 16 novel miRNAs. Interaction networks between differentially expressed miRNAs and their targets were established by mirDIP and Navigator. The prediction results showed that QKI, NFAT5, BNC2, CELF2, LCOR, MBNL2, MTMR3, NFIB, PPARGC1A, RSBN1, TRPS1, WDR26, and ZNF148, which are associated with cellular differentiation and transcriptional regulation, were recognized by 12, 11, or 9 miRNAs. Many correlations were observed between transcriptional or post-transcriptional regulation of an miRNA and the expression levels of its target genes in HRV16-infected H1-HeLa cells.
Subject(s)
MicroRNAs , CELF Proteins/genetics , CELF Proteins/metabolism , DNA-Binding Proteins/genetics , Gene Expression Profiling , Gene Expression Regulation , HeLa Cells , High-Throughput Nucleotide Sequencing , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Nerve Tissue Proteins/genetics , Protein Tyrosine Phosphatases, Non-Receptor , Repressor Proteins/genetics , Repressor Proteins/metabolism , Sequence Analysis, RNA , Transcription Factors/metabolismABSTRACT
Objective: This study aimed to identify internal ribosome entry sites (IRESs) in the open reading frame (ORF) of the Coxsackievirus B3 (CVB3) genome. Methods: The sequences of P1, P2, or P3 of the CVB3 genome or the truncated sequences from each antithymocyte globulin (ATG) to the end of the P1, P2, or P3 gene were inserted into the pEGFP-N1 vector. After transfection, possible IRES-dependent green fluorescent protein (GFP)-fused proteins were detected by anti-GFP western blotting. The sequences of possible IRESs were inserted into specific Fluc/Rluc bicistronic vectors, in which the potential IRESs were determined according to the Fluc/Rluc activity ratio. Expression of Fluc and Rluc mRNA of the bicistronic vector was detected by RT-qPCR. Results: After transfection of full length or truncated sequences of the P1, P2, or P3 plasmids, six GFP-fused protein bands in P1, six bands in P2 and nine bands in P3 were detected through western blotting. Two IRESs in VP2 (1461-1646 nt) and VP1 (2784-2983 nt) of P1; one IRES in 2C (4119-4564 nt) of P2; and two IRESs in 3C (5634-5834 nt) and 3D (6870-7087 nt) of P3 were identified according to Fluc/Rluc activity ratio. The cryptic promoter was also excluded by RT-qPCR. Conclusion: Five IRESs are present in the CVB3 coding region.
Subject(s)
Internal Ribosome Entry Sites , Internal Ribosome Entry Sites/genetics , Open Reading Frames , RNA, Messenger/geneticsABSTRACT
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 HeLa cells, and PERK, IRE1, and ATF6a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.
