Journal: Cell Death and Differentiation
Article Title: Spatio-temporal characterization of the antiviral activity of the XRN1-DCP1/2 aggregation against cytoplasmic RNA viruses to prevent cell death
doi: 10.1038/s41418-020-0509-0
Figure Lengend Snippet: a , b HeLa cells were transfected with indicated siRNAs for 48 h, followed by either arsenite or TNFα treatment at the indicated concentration. Cell viability was measured by MTS assay. c Knockdown efficiency of Bax and Bcl-2 gene was measured by qRT-PCR. d U138 cells were transfected with indicated siRNAs for 48 h. Cells were then infected with EMCV (MOI = 0, 0.01, 0.1, 2, 10, or 20) for 5 h, followed by MTS assay. e MDA5-deficient HeLa cells were generated using Crispr/Cas9 system. Knockout of MDA5 was confirmed by immunoblotting (left). These cells were transfected with indicated siRNAs for 48 h, followed by treatment with vehicle as negative controls or BIP-V5 peptide (100 μM). Cells were then infected with CVB3 (MOI = 0, 0.01, 0.1, 1, 5, 10, or 20) for 5 h and subjected to MTS assay. f MDA5-deficient HeLa cells were transfected with indicated siRNAs for 48 h. Cells were then either treated with dimethyl sulfoxide (DMSO, vehicle), caspase-1 inhibitor (50 μ M), or glycine (5 mM), followed by mock or CVB3 infection (MOI = 1) for 5 h. Supernatant was collected to measure LDH release. g Schematic diagram indicating that, during quiescent state, decapping enzyme DCP1/2 and host 5′–3′ exonuclease XRN1 are mainly localized in PB. Upon viral infection, viral gRNA released from the virion initiates viral replication process, generating copies of different vRNA species (e.g., ssRNA, dsRNA, and mRNA) in various length or with 5′- or 3′-end modifications. The presence of both ss-vRNA and ds-vRNA with the minimum length of at least 100 nt, or multistem loop structure might trigger the specific relocation (blue arrow) of XRN1 and DCP1/2 decapping enzymes into viral replication complexes for vRNA degradation. Consequently, virus-induced, caspase-1-dependent pyroptosis, and Bax-dependent apoptosis are inhibited. (Statistical analyses in c , and f are unpaired Student’s t -test).
Article Snippet: The NDV mature mRNA was in vitro synthesized as previously described [ ] using T7 mScript Standard mRNA kit (CellScript).
Techniques: Transfection, Concentration Assay, MTS Assay, Knockdown, Quantitative RT-PCR, Infection, Generated, CRISPR, Knock-Out, Western Blot, Virus