Epistemic_Statements  

CORD-19:a01a6cdf83b4f97c924da009bc034e8d01ad6f10 JSONTXT 11 Projects

Annnotations TAB TSV DIC JSON TextAE Lectin_function

Id Subject Object Predicate Lexical cue
T1 0-75 Epistemic_statement denotes Silencing of SARS-CoV spike gene by small interfering RNA in HEK 293T cells
T2 86-323 Epistemic_statement denotes Two candidate small interfering RNAs (siRNAs) corresponding to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spike gene were designed and in vitro transcribed to explore the possibility of silencing SARS-CoV S gene.
T3 1241-1612 Epistemic_statement denotes Our findings demonstrated that the S-specific siRNAs used in this study were able to specifically and effectively inhibit SARS-CoV S glycoprotein expression in cultured cells through blocking the accumulation of S mRNA, which may provide an approach for studies on the functions of SARS-CoV S gene and development of novel prophylactic or therapeutic agents for SARS-CoV.
T4 1614-1776 Epistemic_statement denotes The coronaviruses are a diverse group of enveloped positive-strand RNA viruses that can cause respiratory, enteric, and neurologic diseases in their host species.
T5 2565-2751 Epistemic_statement denotes It is believed that binding of S1 subunit to its cellular receptor induces conformational changes in S2, leading to the fusion between viral and cellular membranes, and viral entry [5] .
T6 2894-3104 Epistemic_statement denotes RNA interference (RNAi) is a cellular process in that double-stranded RNA (dsRNA) molecules of 19-23 nucleotides (nt) can silence targeted genes through sequence-specific cleavage of the cognate RNA transcript.
T7 3105-3331 Epistemic_statement denotes The phenomenon was originally discovered in Caenorhabditis elegans in 1998 [7] but has since been observed in numerous organisms including plant, fungus, Drosophila, seaweed, protozoan, and mammal [8] [9] [10] [11] [12] [13] .
T8 3332-3403 Epistemic_statement denotes The RNAi mechanism appears to be mediated by small dsRNA intermediates.
T9 3965-4194 Epistemic_statement denotes To explore the possibility of silencing SARS-CoV S gene by RNAi technique, we cloned and expressed SARS-CoV spike gene, which encodes N-terminal amino acid residues 1-690 and contains the identified receptor-binding domain (RBD).
T10 6289-6398 Epistemic_statement denotes The oligonucleotide directed production of siRNAs with T7 RNA polymerase has been described previously [18] .
T11 10245-10454 Epistemic_statement denotes One microgram of the RNA was then reverse transcribed into cDNA with oligo(dT) 15 and the avian myeloblastosis virus (AMV) reverse transcriptase XL (TaKaRa, Dalian) according to manufacturerÕs recommendations.
T12 12569-12822 Epistemic_statement denotes Equal amounts of total proteins were separated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electrophoretically transferred to nitrocellulose membrane following the protocol suggested by the manufacturer (Bio-Rad, CA).
T13 13554-13731 Epistemic_statement denotes Expression of SARS-CoV S glycoprotein in cultured cells SARS-CoV spike gene was cloned into pEGFP-N1 with a C-terminal EGFP tag that could be used to monitor protein expression.
T14 14480-14610 Epistemic_statement denotes However, the molecular weight of expressed S-EGFP is larger than the predicted one (about 82 kDa) based on amino acid composition.
T15 14611-14738 Epistemic_statement denotes This may represent glycosylated protein which resulted from posttranslational modification by the eukaryotic expression system.
T16 14891-15260 Epistemic_statement denotes The data indicated that replacement of codons in the spike gene with those frequently used in mammalian increased S-EGFP fusion protein expression in cultured cells, supporting the hypothesis that the observed differences in efficiency of expression of modified and unmodified spike genes were related to codon usage and GC content, as shown in other studies [21, 22] .
T17 15261-15486 Epistemic_statement denotes The underlying mechanisms remain to be elucidated but it is possible that partial optimized codon contained in the spike gene could much more efficiently initiate gene transcription and improve efficiency of gene translation.
T18 16735-16925 Epistemic_statement denotes Although siRNAs can be acquired through several methods [25] [26] [27] [28] [29] [30] [31] , transcription in vitro by T7 polymerase adopted here is more convenient and reliable than others.
T19 18656-18804 Epistemic_statement denotes Whether RNAi spreading, as demonstrated in plants and C. elegans [32, 33] , has occurred in this experiment required further experiments to address.
T20 18805-18951 Epistemic_statement denotes The data above suggested that the effect of gene silencing induced by siRNA should be sequence specific and entire open reading frame (ORF) based.
T21 19210-19413 Epistemic_statement denotes To determine whether the synthesized siRNA could effectively silence SARS-CoV S glycoprotein expression in cultured cells, we co-transfected HEK 293T cells with plasmid pEGFP-optS and the various siRNAs.
T22 19503-19525 Epistemic_statement denotes As can be seen in Fig.
T23 21436-21740 Epistemic_statement denotes Interestingly, a little difference in the level of S-EGFP fusion protein expression in S-siRNA1 and S-siRNA2 transfected cells was detected, indicating that the effect of silencing S-EGFP fusion protein expression by S-siRNA2 was better than S-siRNA1, which was consistent with the previous data in Figs.
T24 21854-21975 Epistemic_statement denotes These data indicated that siRNAs silenced SARS-CoV S glycoprotein expression through blocking the accumulation of S mRNA.
T25 22394-22516 Epistemic_statement denotes Therefore, to block the combination of S glycoprotein with receptor efficiently is crucial to prevent the virus infection.
T26 22995-23203 Epistemic_statement denotes Their work enlightened us to explore the possibility of silencing SARS-CoV S glycoprotein expression by siRNA transcribed in vitro by T7 RNA polymerase and blocking its combination with cell surface receptor.
T27 23204-23497 Epistemic_statement denotes In the present work, we cloned wild and codon-optimized SARS-CoV spike gene encoding N-terminal amino acid residues 1-690, which contained the identified receptor-binding domain (RBD), and found that the codonoptimized spike gene can improve the expression of S glycoprotein in cultured cells.
T28 23498-23759 Epistemic_statement denotes Our results demonstrated that the siRNAs transcribed in vitro were effective, and S-siRNA1 and S-siRNA2 can both silence SARS-CoV S glycoprotein expression, which provided evidence for the further study of SARS-CoV infection of cells mediated by S glycoprotein.
T29 23870-24054 Epistemic_statement denotes Our findings in this work could help in the development of novel SARS-CoV therapeutic agent and provide a new strategy for the prevention and treatment of SARS-CoV infection in humans.