Plant diseases and insect pests threaten the safety of crop production greatly. Traditional methods for pest management are challenged by the problems such as environmental pollution, off-target effects, and resistance of pathogens and insects. New biotechnology-based strategies for pest control are expected to be developed. RNA interference (RNAi) is an endogenous process of gene regulation, which has been widely used to study the gene functions in various organisms. In recent years, RNAi-based pest management has received increasing attention. The effective delivery of the exogenous interference RNA into the targets is a key step in RNAi-mediated plant diseases and pest control. Considerable advances were made on the mechanism of RNAi, and various RNA delivery systems were developed for efficient pest control. Here we review the latest advances on mechanisms and influencing factors of RNA delivery, summarize the strategies of exogenous RNA delivery in RNAi-mediated pest control, and highlight the advantages of nanoparticle complexes in dsRNA delivery.
Animals ; RNA Interference ; Pest Control ; Insecta/genetics* ; RNA, Double-Stranded ; Gene Expression Regulation

DNA damage response (DDR) is essential for maintaining genome stability and protecting cells from tumorigenesis. Ubiquitin and ubiquitin-like modifications play an important role in DDR, from signaling DNA damage to mediating DNA repair. In this report, we found that the E3 ligase ring finger protein 126 (RNF126) was recruited to UV laser micro-irradiation-induced stripes in a RNF8-dependent manner. RNF126 directly interacted with and ubiquitinated another E3 ligase, RNF168. Overexpression of wild type RNF126, but not catalytically-inactive mutant RNF126 (CC229/232AA), diminished ubiquitination of H2A histone family member X (H2AX), and subsequent bleomycin-induced focus formation of total ubiquitin FK2, TP53-binding protein 1 (53BP1), and receptor-associated protein 80 (RAP80). Interestingly, both RNF126 overexpression and RNF126 downregulation compromised homologous recombination (HR)-mediated repair of DNA double-strand breaks (DSBs). Taken together, our findings demonstrate that RNF126 negatively regulates RNF168 function in DDR and its appropriate cellular expression levels are essential for HR-mediated DSB repair.
Carrier Proteins ; metabolism ; Cell Line, Tumor ; DNA Breaks, Double-Stranded ; DNA Repair ; genetics ; DNA-Binding Proteins ; metabolism ; Genomic Instability ; HeLa Cells ; Histones ; metabolism ; Humans ; Nuclear Proteins ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; Signal Transduction ; Tumor Suppressor p53-Binding Protein 1 ; metabolism ; Ubiquitin ; Ubiquitin-Protein Ligases ; genetics ; metabolism ; Ubiquitination

Cytosolic retinoic acid-inducible gene I (RIG-I) is an important innate immune RNA sensor and can induce antiviral cytokines, e.g., interferon-β (IFN-β). Innate immune response to hepatitis B virus (HBV) plays a pivotal role in viral clearance and persistence. However, knowledge of the role that RIG-I plays in HBV infection is limited. The woodchuck is a valuable model for studying HBV infection. To characterize the molecular basis of woodchuck RIG-I (wRIG-I), we analyzed the complete coding sequences (CDSs) of wRIG-I, containing 2778 base pairs that encode 925 amino acids. The deduced wRIG-I protein was 106.847 kD with a theoretical isoelectric point (pI) of 6.07, and contained three important functional structures [caspase activation and recruitment domains (CARDs), DExD/H-box helicases, and a repressor domain (RD)]. In woodchuck fibroblastoma cell line (WH12/6), wRIG-I-targeted small interfering RNA (siRNA) down-regulated RIG-I and its downstrean effector-IFN-β transcripts under RIG-I' ligand, 5'-ppp double stranded RNA (dsRNA) stimulation. We also measured mRNA levels of wRIG-I in different tissues from healthy woodchucks and in the livers from woodchuck hepatitis virus (WHV)-infected woodchucks. The basal expression levels of wRIG-I were abundant in the kidney and liver. Importantly, wRIG-I was significantly up-regulated in acutely infected woodchuck livers, suggesting that RIG-I might be involved in WHV infection. These results may characterize RIG-I in the woodchuck model, providing a strong basis for further study on RIG-I-mediated innate immunity in HBV infection.
Animals ; Cell Line, Tumor ; Cloning, Molecular ; DEAD Box Protein 58 ; antagonists & inhibitors ; genetics ; immunology ; Fibroblasts ; immunology ; pathology ; Gene Expression ; Hepatitis B ; genetics ; immunology ; pathology ; veterinary ; Hepatitis B Virus, Woodchuck ; Immunity, Innate ; Interferon-beta ; genetics ; immunology ; Isoelectric Point ; Kidney ; immunology ; pathology ; virology ; Liver ; immunology ; pathology ; virology ; Marmota ; genetics ; immunology ; virology ; Open Reading Frames ; Protein Domains ; RNA, Double-Stranded ; RNA, Small Interfering ; genetics ; metabolism ; Rodent Diseases ; genetics ; immunology ; pathology ; virology

Meiotic recombination is carried out through a specialized pathway for the formation and repair of DNA double-strand breaks (DSBs) made by the Spo11 protein. The present study shed light on the functional role of cyclin, CYC2, in Tetrahymena thermophila which has transcriptionally high expression level during meiosis process. Knocking out the CYC2 gene results in arrest of meiotic conjugation process at 2.5-3.5 h after conjugation initiation, before the meiosis division starts, and in company with the absence of DSBs. To investigate the underlying mechanism of this phenomenon, a complete transcriptome profile was performed between wild-type strain and CYC2 knock-out strain. Functional analysis of RNA-Seq results identifies related differentially expressed genes (DEGs) including SPO11 and these DEGs are enriched in DNA repair/mismatch repair (MMR) terms in homologous recombination (HR), which indicates that CYC2 could play a crucial role in meiosis by regulating SPO11 and participating in HR.
Cell Cycle Checkpoints ; Cyclins ; genetics ; metabolism ; DNA Breaks, Double-Stranded ; DNA Mismatch Repair ; DNA Repair ; Endodeoxyribonucleases ; genetics ; metabolism ; Homologous Recombination ; Meiosis ; Microscopy, Fluorescence ; Phenotype ; Protozoan Proteins ; genetics ; metabolism ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, RNA ; Tetrahymena thermophila ; genetics ; metabolism ; Transcriptome

RIG-I-like receptors (RLRs) belong to pattern recognition receptors, which perform significant roles in antiviral responses. RLRs can initiate a cascade of signaling transduction that induces the production of type I interferon and activates the interferon signaling pathway, ultimately resulting in antiviral responses. In the course of evolution, viruses have been constantly counteracting host immune systems to facilitate their own survival and replication, and have developed a set of antagonistic strategies. These mainly comprise elusion, disguise and attack strategies to eliminate the activation of RLRs. In virus-infected cells, RLRs recognize viral RNA and then induce antiviral responses. A better understanding of viral antagonistic strategies against RLRs will provide insights into the development of new antiviral medicines. This mini-review concludes that there are three main antagonistic strategies by which RNA viruses can counteract the activation of the RLRs pathway. It aims to provide references and insights for similar studies on viral antagonism in an array of RNA viruses.
DEAD Box Protein 58 ; DEAD-box RNA Helicases ; genetics ; immunology ; Host-Pathogen Interactions ; Humans ; RNA Viruses ; genetics ; immunology ; physiology ; RNA, Double-Stranded ; genetics ; immunology ; RNA, Viral ; genetics ; immunology ; Virus Diseases ; genetics ; immunology ; virology

OBJECTIVETo investigate the role of histone acetylation in regulating influenza virus replicative intermediate double-stranded RNA (dsRNA)-induced interleukin-6 (IL-6) expression in A549 cells.

METHODSA549 cells were treated with influenza virus replicative intermediate dsRNA, histone deacetylase (HDAC) inhibitor trichostatin A (TSA), or HADC small interfering RNA (siRNA). The changes in the cellular IL-6 promoter activities were detected by dual-luciferase assay, and IL-6 mRNA and protein expressions in the cells were determined using real-time RT-PCR and ELISA, respectively.

RESULTSInfluenza virus replicative intermediate dsRNA obviously up-regulated IL-6 expression in the cells. HDAC inhibitor TSA significantly enhanced the activity of IL-6 promoter and increased IL-6 mRNA expression in A549 cells, and HDAC3 may play an important role in this process. HDAC inhibitor TSA and DNMT inhibitor DAC showed no synergic effect in regulating IL-6 expression.

CONCLUSIONSInfluenza virus replicative intermediate dsRNA-induced IL-6 expression in A549 cells is regulated by histone acetylation.

Acetylation ; Cell Line, Tumor ; Gene Expression Regulation ; Histone Deacetylase Inhibitors ; pharmacology ; Histones ; metabolism ; Humans ; Interleukin-6 ; metabolism ; Orthomyxoviridae ; genetics ; metabolism ; Promoter Regions, Genetic ; RNA, Double-Stranded ; RNA, Messenger ; genetics ; RNA, Viral

Animals ; Apoptosis ; Cadherins ; genetics ; metabolism ; Epigenesis, Genetic ; Gene Expression Regulation, Neoplastic ; Humans ; MicroRNAs ; genetics ; metabolism ; physiology ; Neoplasm Invasiveness ; Neoplasms ; genetics ; metabolism ; pathology ; therapy ; RNA, Double-Stranded ; genetics ; metabolism ; physiology ; RNA, Small Interfering ; genetics ; metabolism ; physiology ; RNA, Small Untranslated ; genetics ; metabolism ; physiology ; therapeutic use ; Transcriptional Activation

OBJECTIVETo explore the relationship between epidermal growth factor receptor (EGFR) gene expression and radiosensitivity of non-small-cell lung cancer (NSCLC) cells.

METHODSEGFR sequence-specific double-stranded RNA (dsRNA-EGFR) was chemically synthesized. NSCLC cell line SPC-A1 was transfected with dsRNA-EGFR formulated with Lipofectamine 2000. Western blot and real-time PCR were used to determine the EGFR mRNA and protein expression, respectively. Colony inhibition test was adopted to observe the radiosensitizing effect. To establish the nude mouse tumor models, calculate the tumor growth inhibition rate and make the tumor growth curve by measuring its size and weight.

RESULTSEGFR mRNA levels were 1.51 ± 0.22, 1.38 ± 0.15 and 0.45 ± 0.11 in the control group, dsRNA-unrelated group and dsRNA-EGFR group, respectively (F = 482.7, P < 0.01). The contents of EGFR protein were 2340.87 ± 10.99, 2231.85 ± 35.66 and 832.03 ± 39.13 in the control group, dsRNA-unrelated group and dsRNA-EGFR group, respectively (F = 263.3, P < 0.05). Compared with the control group, dsRNA-EGFR sequence specifically decreased the expressions of EGFR mRNA by 70.2% and EGFR protein by 64.5%. The colony inhibition rates of the control group, dsRNA-unrelated combined with radiotherapy group and dsRNA-EGFR combined with radiotherapy group were 9.3%, 12.5% and 65.5%, and the tumor growth inhibition rates were 21.3%, 24.4% and 64.2%, respectively. The combination of dsRNA-EGFR and radiotherapy significantly inhibited the tumor growth in vitro and in vivo.

CONCLUSIONSDsRNA-EGFR shows an apparent inhibitory effect on the expression of EGFR mRNA and protein of NSCLC cells, effectively inhibit the tumor growth in vivo, and enhance the radiosensitivity of NSCLC.

Adenocarcinoma ; metabolism ; pathology ; radiotherapy ; Animals ; Cell Line, Tumor ; Cell Proliferation ; radiation effects ; Humans ; Lung Neoplasms ; metabolism ; pathology ; radiotherapy ; Male ; Mice ; Mice, Nude ; Neoplasm Transplantation ; RNA, Double-Stranded ; genetics ; RNA, Messenger ; metabolism ; Radiation Tolerance ; Random Allocation ; Receptor, Epidermal Growth Factor ; genetics ; metabolism ; Transfection ; Tumor Burden ; radiation effects

Retinoic acid-inducible gene I (RIG-I) is an important pattern recognition receptor that detects viral RNA and triggers the production of type-I interferons through the downstream adaptor MAVS (also called IPS-1, CARDIF, or VISA). A series of structural studies have elaborated some of the mechanisms of dsRNA recognition and activation of RIG-I. Recent studies have proposed that K63-linked ubiquitination of, or unanchored K63-linked polyubiquitin binding to RIG-I positively regulates MAVS-mediated antiviral signaling. Conversely phosphorylation of RIG-I appears to play an inhibitory role in controlling RIG-I antiviral signal transduction. Here we performed a combined structural and biochemical study to further define the regulatory features of RIG-I signaling. ATP and dsRNA binding triggered dimerization of RIG-I with conformational rearrangements of the tandem CARD domains. Full length RIG-I appeared to form a complex with dsRNA in a 2:2 molar ratio. Compared with the previously reported crystal structures of RIG-I in inactive state, our electron microscopic structure of full length RIG-I in complex with blunt-ended dsRNA, for the first time, revealed an exposed active conformation of the CARD domains. Moreover, we found that purified recombinant RIG-I proteins could bind to the CARD domain of MAVS independently of dsRNA, while S8E and T170E phosphorylation-mimicking mutants of RIG-I were defective in binding E3 ligase TRIM25, unanchored K63-linked polyubiquitin, and MAVS regardless of dsRNA. These findings suggested that phosphorylation of RIG inhibited downstream signaling by impairing RIG-I binding with polyubiquitin and its interaction with MAVS.
Adaptor Proteins, Signal Transducing ; metabolism ; Adenosine Triphosphate ; metabolism ; DEAD Box Protein 58 ; DEAD-box RNA Helicases ; chemistry ; genetics ; metabolism ; Dimerization ; Humans ; Mutagenesis, Site-Directed ; Phosphorylation ; Polyubiquitin ; metabolism ; Protein Binding ; Protein Structure, Tertiary ; RNA, Double-Stranded ; metabolism ; Recombinant Proteins ; biosynthesis ; chemistry ; genetics ; Signal Transduction ; Transcription Factors ; metabolism ; Tripartite Motif Proteins ; Ubiquitin-Protein Ligases ; metabolism ; Ubiquitination

OBJECTIVETo study the effect of RNA interference (RNAi) on small heat shock protein (sHSP) Sjp40 of Schistosoma japonicum and its synergistic effect on the expression of SjHSP60, SjHSP70, and SjHSP90 mRNA, and observe the mRNA expression levels of Sjp40, SjHSP60, SjHSP70, and SjHSP90 in different stages of S.japonicum.

METHODSDouble-stranded RNA (dsRNA) of Sjp40 (dsSjp40) and a control dsRNA of green fluorescent protein (dsGFP) were generated by in vitro transcription and transfected into adult worm by immersing the worm in dsRNA solution. The total RNA and proteins were isolated simultaneously from the adult worms using TRIzol reagent 7 days after transfection. The expression levels of Sjp40, SjHSP60, SjHSP70, and SjHSP90 mRNA and the expression level of Sjp40 protein were determined by quantitative real-time PCR (qPCR) and Western blotting, respectively. The mRNA expression of HSPs of S. japonicum in different stages was evaluated by qPCR.

RESULTSCompared with those in the control worms transfected with dsGFP, Sjp40 mRNA level was decreased by 80% in the worms transfected with dsSjp40, and the level of Sjp40 protein showed also a significant decrease. The mRNA expression levels of SjHSP60, SjHSP70, and SjHSP90 did not show an obvious synergism after Sjp40 RNAi. The expression profiles of Sjp40, SjHSP60, SjHSP70, and SjHSP90 showed significant differences in different stages of S. japonicum, and the expression level of Sjp40 mRNA in the egg stage was much higher than that of other HSP genes.

CONCLUSIONdsSjp40-RNAi can induce effective suppression of Sjp40 gene expression at both mRNA and protein levels, but no obvious synergism occurs in the mRNA expressions of SjHSP60, SjHSP70, and SjHSP90.

Animals ; Gene Expression Profiling ; Heat-Shock Proteins, Small ; genetics ; Helminth Proteins ; genetics ; RNA Interference ; RNA, Double-Stranded ; RNA, Messenger ; genetics ; Schistosoma japonicum ; genetics