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  1. Inhibition of virus replication by RNA interference

    NARCIS (Netherlands)

    Haasnoot, P. C. Joost; Cupac, Daniel; Berkhout, Ben

    2003-01-01

    RNA interference (RNAi) is a sequence-specific gene-silencing mechanism in eukaryotes, which is believed to function as a defence against viruses and transposons. Since its discovery, RNAi has been developed into a widely used technique for generating genetic knock-outs and for studying gene

  2. RNA interference targeting raptor inhibits proliferation of gastric cancer cells

    International Nuclear Information System (INIS)

    Wu, William Ka Kei; Lee, Chung Wa; Cho, Chi Hin; Chan, Francis Ka Leung; Yu, Jun; Sung, Joseph Jao Yiu

    2011-01-01

    Mammalian target of rapamycin complex 1 (mTORC1) is dysregulated in gastric cancer. The biologic function of mTORC1 in gastric carcinogenesis is unclear. Here, we demonstrate that disruption of mTORC1 function by RNA interference-mediated downregulation of raptor substantially inhibited gastric cancer cell proliferation through induction of G 0 /G 1 -phase cell cycle arrest. The anti-proliferative effect was accompanied by concomitant downregulation of activator protein-1 and upregulation of Smad2/3 transcriptional activities. In addition, the expression of cyclin D 3 and p21 Waf1 , which stabilizes cyclin D/cdk4 complex for G 1 -S transition, was reduced by raptor knockdown. In conclusion, disruption of mTORC1 inhibits gastric cancer cell proliferation through multiple pathways. This discovery may have an implication in the application of mTORC1-directed therapy for the treatment of gastric cancer.

  3. Inhibition of osteoclastogenesis by RNA interference targeting RANK

    Directory of Open Access Journals (Sweden)

    Ma Ruofan

    2012-08-01

    Full Text Available Abstract Background Osteoclasts and osteoblasts regulate bone resorption and formation to allow bone remodeling and homeostasis. The balance between bone resorption and formation is disturbed by abnormal recruitment of osteoclasts. Osteoclast differentiation is dependent on the receptor activator of nuclear factor NF-kappa B (RANK ligand (RANKL as well as the macrophage colony-stimulating factor (M-CSF. The RANKL/RANK system and RANK signaling induce osteoclast formation mediated by various cytokines. The RANK/RANKL pathway has been primarily implicated in metabolic, degenerative and neoplastic bone disorders or osteolysis. The central role of RANK/RANKL interaction in osteoclastogenesis makes RANK an attractive target for potential therapies in treatment of osteolysis. The purpose of this study was to assess the effect of inhibition of RANK expression in mouse bone marrow macrophages on osteoclast differentiation and bone resorption. Methods Three pairs of short hairpin RNAs (shRNA targeting RANK were designed and synthesized. The optimal shRNA was selected among three pairs of shRNAs by RANK expression analyzed by Western blot and Real-time PCR. We investigated suppression of osteoclastogenesis of mouse bone marrow macrophages (BMMs using the optimal shRNA by targeting RANK. Results Among the three shRANKs examined, shRANK-3 significantly suppressed [88.3%] the RANK expression (p Conclusions These findings suggest that retrovirus-mediated shRNA targeting RANK inhibits osteoclast differentiation and osteolysis. It may appear an attractive target for preventing osteolysis in humans with a potential clinical application.

  4. RNA interference inhibits herpes simplex virus type 1 isolated from saliva samples and mucocutaneous lesions.

    Science.gov (United States)

    Silva, Amanda Perse da; Lopes, Juliana Freitas; Paula, Vanessa Salete de

    2014-01-01

    The aim of this study was to evaluate the use of RNA interference to inhibit herpes simplex virus type-1 replication in vitro. For herpes simplex virus type-1 gene silencing, three different small interfering RNAs (siRNAs) targeting the herpes simplex virus type-1 UL39 gene (sequence si-UL 39-1, si-UL 39-2, and si-UL 39-3) were used, which encode the large subunit of ribonucleotide reductase, an essential enzyme for DNA synthesis. Herpes simplex virus type-1 was isolated from saliva samples and mucocutaneous lesions from infected patients. All mucocutaneous lesions' samples were positive for herpes simplex virus type-1 by real-time PCR and by virus isolation; all herpes simplex virus type-1 from saliva samples were positive by real-time PCR and 50% were positive by virus isolation. The levels of herpes simplex virus type-1 DNA remaining after siRNA treatment were assessed by real-time PCR, whose results demonstrated that the effect of siRNAs on gene expression depends on siRNA concentration. The three siRNA sequences used were able to inhibit viral replication, assessed by real-time PCR and plaque assays and among them, the sequence si-UL 39-1 was the most effective. This sequence inhibited 99% of herpes simplex virus type-1 replication. The results demonstrate that silencing herpes simplex virus type-1 UL39 expression by siRNAs effectively inhibits herpes simplex virus type-1 replication, suggesting that siRNA based antiviral strategy may be a potential therapeutic alternative. Copyright © 2014. Published by Elsevier Editora Ltda.

  5. Establishment and Evaluation of Stable Cell Lines Inhibiting Foot-and-Mouth Disease Virus by RNA Interference

    Directory of Open Access Journals (Sweden)

    Yuan-xing Gu

    2014-01-01

    Full Text Available RNA interference (RNAi has been proved to be a powerful tool for foot-and-mouth disease virus FMDV inhibition in vitro and in vivo. We established five stable baby hamster kidney 21 cell lines (BHK-21 containing five short hairpin RNAs (shRNAs expression plasmids (p3D1shRNA, p3D2shRNA, p3D3shRNA, p3D4shRNA, and p3D5shRNA targeting 3D gene of FMDV. Immunofluorescent assay, virus titration, and real-time quantitative reverse transcription polymerase chain reaction (Q-RT-PCR were conducted to detect the effect of shRNAs on FMDV replication. After challenged with FMDV of O/CHA/99, two cell lines (p3D1shRNA and p3D4shRNA showed a significant reduction in the synthesis of viral protein and RNA, accompanied by a sharp decrease in viral yield, and the inhibition could last for at least thirty passages. We developed an efficient procedure for the establishment and evaluation of stable cell lines for anti-FMDV research based on RNAi technology, which can be a candidate method for anti-FMDV research.

  6. RNA interference mediated pten knock-down inhibit the formation of polycystic ovary.

    Science.gov (United States)

    Ouyang, Jie-Xiu; Luo, Tao; Sun, Hui-Yun; Huang, Jian; Tang, Dan-Feng; Wu, Lei; Zheng, Yue-Hui; Zheng, Li-Ping

    2013-08-01

    Pten (phosphatase and tensin homolog deleted on chromosome 10), a kind of tumor suppressor gene, plays important roles in female reproductive system. But its expression and roles in the formation of polycystic ovaries are yet to be known. In this study, we constructed a rat model of PCOS using norethindrone and HCG injections and found the expressions of pten mRNA and PTEN protein increased significantly in the polycystic ovary tissue by immunohistochemistry, RT-PCR, and western blot. Furthermore, the results showed that in vivo ovaries could be effectively transfected by lentiviral vectors through the ovarian microinjection method and indicated that pten shRNA may inhibit the formation of polycystic ovaries by pten down-regulation. Our study provides new information regarding the role of PTEN in female reproductive disorders, such as polycystic ovary syndrome.

  7. Targeting SPARC by lentivirus-mediated RNA interference inhibits cervical cancer cell growth and metastasis

    International Nuclear Information System (INIS)

    Chen, Jie; Shi, Dehuan; Liu, Xiaoyan; Fang, Shuang; Zhang, Jie; Zhao, Yueran

    2012-01-01

    Secreted protein acidic and rich in cysteine (SPARC), a calcium-binding matricellular glycoprotein, is implicated in the progressions of some cancers. However, no information has been available to date regarding the function of SPARC in cervical cancer cell growth and metastasis. In this study, we isolated and established high invasive subclones and low invasive subclones from human cervical cancer cell lines HeLa and SiHa by the limited dilution method. Real-time q-RT-PCR, Western Blot and ICC were performed to investigate SPARC mRNA and protein expressions in high invasive subclones and low invasive subclones. Then lentivirus vector with SPARC shRNA was constructed and infected the highly invasive subclones. Real-time q-RT-PCR, Western Blot and ICC were also performed to investigate the changes of SPARC expression after viral infection. In functional assays, effects of SPARC knockdown on the biological behaviors of cervical cancer cells were investigated. The mechanisms of SPARC in cervical cancer proliferation, apoptosis and invasion were also researched. SPARC was over-expressed in the highly invasive subclones compared with the low invasive subclones. Knockdown of SPARC significantly suppressed cervical cancer cell proliferation, and induced cell cycle arrest at the G1/G0 phase through the p53/p21 pathway, also caused cell apoptosis accompanied by the decreased ratio of Bcl-2/Bax, and inhibited cell invasion and metastasis accompanied by down-regulated MMP2 and MMP9 expressions and up-regulated E-cadherin expression. SPARC is related to the invasive phenotype of cervical cancer cells. Knockdown of SPARC significantly suppresses cervical cancer cell proliferation, induces cell apoptosis and inhibits cell invasion and metastasis. SPARC as a promoter improves cervical cancer cell growth and metastasis

  8. Targeting SPARC by lentivirus-mediated RNA interference inhibits cervical cancer cell growth and metastasis

    Directory of Open Access Journals (Sweden)

    Chen Jie

    2012-10-01

    Full Text Available Abstract Background Secreted protein acidic and rich in cysteine (SPARC, a calcium-binding matricellular glycoprotein, is implicated in the progressions of some cancers. However, no information has been available to date regarding the function of SPARC in cervical cancer cell growth and metastasis. Methods In this study, we isolated and established high invasive subclones and low invasive subclones from human cervical cancer cell lines HeLa and SiHa by the limited dilution method. Real-time q-RT-PCR, Western Blot and ICC were performed to investigate SPARC mRNA and protein expressions in high invasive subclones and low invasive subclones. Then lentivirus vector with SPARC shRNA was constructed and infected the highly invasive subclones. Real-time q-RT-PCR, Western Blot and ICC were also performed to investigate the changes of SPARC expression after viral infection. In functional assays, effects of SPARC knockdown on the biological behaviors of cervical cancer cells were investigated. The mechanisms of SPARC in cervical cancer proliferation, apoptosis and invasion were also researched. Results SPARC was over-expressed in the highly invasive subclones compared with the low invasive subclones. Knockdown of SPARC significantly suppressed cervical cancer cell proliferation, and induced cell cycle arrest at the G1/G0 phase through the p53/p21 pathway, also caused cell apoptosis accompanied by the decreased ratio of Bcl-2/Bax, and inhibited cell invasion and metastasis accompanied by down-regulated MMP2 and MMP9 expressions and up-regulated E-cadherin expression. Conclusion SPARC is related to the invasive phenotype of cervical cancer cells. Knockdown of SPARC significantly suppresses cervical cancer cell proliferation, induces cell apoptosis and inhibits cell invasion and metastasis. SPARC as a promoter improves cervical cancer cell growth and metastasis.

  9. Inhibition of endothelial cell proliferation by targeting Rac1 GTPase with small interference RNA in tumor cells

    International Nuclear Information System (INIS)

    Xue Yan; Bi Feng; Zhang Xueyong; Pan Yanglin; Liu Na; Zheng Yi; Fan Daiming

    2004-01-01

    Hypoxia-induced angiogenesis plays an important role in the malignancy of solid tumors. A number of recent studies including our own have suggested that Rho family small GTPases are involved in this process, and Rac1, a prominent member of the Rho family, may be critical in regulating hypoxia-induced gene activation of several angiogenesis factors and tumor suppressors. To further define Rac1 function in angiogenesis and to explore novel approaches to modulate angiogenesis, we employed the small interference RNA technique to knock down gene expression of Rac1 in gastric cancer cell line AGS that expresses a high level of Rac1. Both the mRNA and protein levels of Rac1 in the AGS cells were decreased dramatically after transfection with a Rac1-specific siRNA vector. When the conditioned medium derived from the Rac1 downregulated AGS cells was applied to the human endothelial cells, it could significantly inhibit the cell proliferation. Further study proved that, VEGF and HIF-1α, two angiogenesis promoting factors, were found to be downregulated whereas p53 and VHL, which are tumor suppressors and angiogenesis inhibitors, were upregulated in the Rac1 siRNA transfected cells. Our results suggest that Rac1 may be involved in angiogenesis by controlling the expression of angiogenesis-related factors and provide a possible strategy for the treatment of tumor angiogenesis by targeting the Rac1 GTPase

  10. Targeting CCl4 -induced liver fibrosis by RNA interference-mediated inhibition of cyclin E1 in mice.

    Science.gov (United States)

    Bangen, Jörg-Martin; Hammerich, Linda; Sonntag, Roland; Baues, Maike; Haas, Ute; Lambertz, Daniela; Longerich, Thomas; Lammers, Twan; Tacke, Frank; Trautwein, Christian; Liedtke, Christian

    2017-10-01

    Initiation and progression of liver fibrosis requires proliferation and activation of resting hepatic stellate cells (HSCs). Cyclin E1 (CcnE1) is the regulatory subunit of the cyclin-dependent kinase 2 (Cdk2) and controls cell cycle re-entry. We have recently shown that genetic inactivation of CcnE1 prevents activation, proliferation, and survival of HSCs and protects from liver fibrogenesis. The aim of the present study was to translate these findings into preclinical applications using an RNA interference (RNAi)-based approach. CcnE1-siRNA (small interfering RNA) efficiently inhibited CcnE1 gene expression in murine and human HSC cell lines and in primary HSCs, resulting in diminished proliferation and increased cell death. In C57BL/6 wild-type (WT) mice, delivery of stabilized siRNA using a liposome-based carrier targeted approximately 95% of HSCs, 70% of hepatocytes, and 40% of CD45 + cells after single injection. Acute CCl 4 -mediated liver injury in WT mice induced endogenous CcnE1 expression and proliferation of surviving hepatocytes and nonparenchymal cells, including CD45 + leukocytes. Pretreatment with CcnE1-siRNA reverted CcnE1 induction to baseline levels of healthy mice, which was associated with reduced liver injury, diminished proliferation of hepatocytes and leukocytes, and attenuated overall inflammatory response. For induction of liver fibrosis, WT mice were challenged with CCl 4 for 4-6 weeks. Co-treatment with CcnE1-siRNA once a week was sufficient to continuously block CcnE1 expression and cell-cycle activity of hepatocytes and nonparenchymal cells, resulting in significantly ameliorated liver fibrosis and inflammation. Importantly, CcnE1-siRNA also prevented progression of liver fibrosis if applied after onset of chronic liver injury. Therapeutic targeting of CcnE1 in vivo using RNAi is feasible and has high antifibrotic activity. (Hepatology 2017;66:1242-1257). © 2017 by the American Association for the Study of Liver Diseases.

  11. [RNA interference of HERC4 inhibits proliferation, apoptosis and migration of cervical cancer Hela cells].

    Science.gov (United States)

    Wei, Min; Zhang, Yan-Ling; Chen, Lan; Cai, Cui-Xia; Wang, Han-Duo

    2016-02-20

    To explore the effects of silencing HERC4 on the proliferation, apoptosis, and migration of cervical cancer cell line Hela and the possible molecular mechanisms. Three HERC4-specific small interfering RNAs (siRNAs) were transfected into Hela cells, and HERC4 expression in the cells was examined with Western blotting. CCK-8 assay, annexin V-FITC/PI assay, and wound healing assay were used to assess the effect of HERC4 silencing on the proliferation, apoptosis and migration ability of Hela cells. The expression levels of cyclin D1 and Bcl-2 in the cells were detected using Western blotting. Transfection of siRNA-3 resulted in significantly decreased HERC4 protein expression (PHela cells, increased the apoptosis rate (PHela cells in vitro, and the underlying mechanisms may involve the down-regulation of cyclin D1 and Bcl-2.

  12. Targeting S100P Inhibits Colon Cancer Growth and Metastasis by Lentivirus-Mediated RNA Interference and Proteomic Analysis

    Science.gov (United States)

    Jiang, Lei; Lai, Yiu-Kay; Zhang, Jinfang; Wang, Hua; Lin, Marie CM; He, Ming-liang; Kung, Hsiang-fu

    2011-01-01

    S100P was recently found to be overexpressed in a variety of cancers and is considered a potential target for cancer therapy, but the functional role or mechanism of action of S100P in colon cancer is not fully understood. In the present study, we knocked down the gene expression of S100P in colon cancer cells using lentivirus-mediated RNA interference. This step resulted in significant inhibition of cancer cell growth, migration and invasion in vitro and tumor growth and liver metastasis in vivo. Moreover, S100P downstream target proteins were identified by proteomic analysis in colon cancer DLD-1 cells with deletion of S100P. Knockdown of S100P led to downregulation of thioredoxin 1 and β-tubulin and upregulation of Rho guanosine diphosphate (GDP) dissociation inhibitor α (RhoGDIA), all potential therapeutic targets in cancer. Taken together, these findings suggest that S100P plays an important role in colon tumorigenesis and metastasis, and the comprehensive and comparative analyses of proteins associated with S100P could contribute to understanding the downstream signal cascade of S100P, leading to tumorigenesis and metastasis. PMID:21327297

  13. In vitro and in vivo inhibition of rabies virus replication by RNA interference.

    Science.gov (United States)

    Durymanova Ono, Ekaterina A; Iamamoto, Keila; Castilho, Juliana G; Carnieli, Pedro; de Novaes Oliveira, Rafael; Achkar, Samira M; Carrieri, Maria L; Kotait, Ivanete; Brandão, Paulo E

    2013-01-01

    Rabies is a zoonotic disease that affects all mammals and leads to more than 55,000 human deaths every year, caused by rabies virus (RABV) (Mononegavirales: Rhabdoviridae: Lyssavirus). Currently, human rabies treatment is based on the Milwaukee Protocol which consists on the induction of coma and massive antiviral therapy. The aim of this study was to assess the decrease in the titer of rabies virus both in vitro and in vivo using short-interfering RNAs. To this end, three siRNAs were used with antisense strands complementary to rabies virus nucleoprotein (N) mRNA. BHK-21 cells monolayers were infected with 1000 to 0.1 TCID50 of PV and after 2 hours the cells were transfected with each of tree RNAs in separate using Lipofectamine-2000. All three siRNAs reduced the titer of PV strain in a least 0.72 logTCID50/mL and no cytotoxic effect was observed in the monolayers treated with Lipofectamine-2000. Swiss albino mice infected with 10.000 to 1 LD of PV strain by the intracerebral route were also transfected after two hours of infection with a pool 3 siRNAs with Lipofectamine-2000 by the intracerebral route, resulting in a survival rate of 30% in mice inoculated with 100 LD50, while the same dose led to 100% mortality in untreated animals. Lipofectamine-2000 showed no toxic effect in control mice. These results suggest that intracerebral administration of siRNAs might be an effective antiviral strategy for rabies.

  14. In vitro and in vivo inhibition of rabies virus replication by RNA interference

    Directory of Open Access Journals (Sweden)

    Ekaterina A. Durymanova Ono

    2013-09-01

    Full Text Available Rabies is a zoonotic disease that affects all mammals and leads to more than 55,000 human deaths every year, caused by rabies virus (RABV (Mononegavirales: Rhabdoviridae: Lyssavirus. Currently, human rabies treatment is based on the Milwaukee Protocol which consists on the induction of coma and massive antiviral therapy. The aim of this study was to assess the decrease in the titer of rabies virus both in vitro and in vivo using short-interfering RNAs. To this end, three siRNAs were used with antisense strands complementary to rabies virus nucleoprotein (N mRNA. BHK-21 cells monolayers were infected with 1000 to 0.1 TCID50 of PV and after 2 hours the cells were transfected with each of tree RNAs in separate using Lipofectamine-2000. All three siRNAs reduced the titer of PV strain in a least 0.72 logTCID50/mL and no cytotoxic effect was observed in the monolayers treated with Lipofectamine-2000. Swiss albino mice infected with 10.000 to 1 LD of PV strain by the intracerebral route were also transfected after two hours of infection with a pool 3 siRNAs with Lipofectamine-2000 by the intracerebral route, resulting in a survival rate of 30% in mice inoculated with 100 LD50, while the same dose led to 100% mortality in untreated animals. Lipofectamine-2000 showed no toxic effect in control mice. These results suggest that intracerebral administration of siRNAs might be an effective antiviral strategy for rabies.

  15. RNA interference in Lepidoptera

    DEFF Research Database (Denmark)

    Terenius, Ole; Papanicolaou, Alexie; Garbutt, Jennie S.

    2011-01-01

    in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as our...... experiments have not been collected in such a way that they are possible to analyze. In this review, we have collected detailed data from more than 150 experiments including all to date published and many unpublished experiments. Despite a large variation in the data, trends that are found are that RNAi...... is particularly successful in the family Saturniidae and in genes involved in immunity. On the contrary, gene expression in epidermal tissues seems to be most difficult to silence. In addition, gene silencing by feeding dsRNA requires high concentrations for success. Possible causes for the variability of success...

  16. Reduced STMN1 expression induced by RNA interference inhibits the bioactivity of pancreatic cancer cell line Panc-1.

    Science.gov (United States)

    Li, J; Hu, G H; Kong, F J; Wu, K M; He, B; Song, K; Sun, W J

    2014-01-01

    Increased expression of STMN1 has been observed in many tumor forms, but its expression and potential biological role in pancreatic cancer is still unknown. In this study, we demonstrated that STMN1 was expressed to a large extent in pancreatic cancer tissues and cell lines as compared to normal pancreatic tissues. Suppression of STMN1 expression via transfection with STMN1-specific siRNA could not only significantly inhibit the proliferation, migration and invasion ability of Panc-1 cells, but also enhance the apoptosis of Panc-1 cells. In addition, downregulation of STMN1 obviously enhanced the acetylation level of α-tubulin. All these results indicated that STMN1 plays an important role in pancreatic cancer development, and might serve as a potential therapeutic target for pancreatic cancer.

  17. Intervention of radiation‐induced skin fibrosis by RNA interference

    DEFF Research Database (Denmark)

    Nawroth, Isabel

    ‐α (TNFα) production by macrophages might promote RIF. RNA interference (RNAi) is an evolutionary conserved gene‐silencing mechanism capable of degrading mRNA containing a homologous sequence to an exogenously introduced double stranded small interfering RNA (siRNA). These siRNAs can induce RNAi...... and inhibit the expression of target proteins. Therefore, siRNAs are considered as promising therapeutics for treatment of various diseases including genetic and viral diseases, and cancer. In this study, the therapeutic potential of RNA interference was investigated as an intervention strategy for radiation......‐induced skin fibrosis. Chitosan‐based nanoparticles (or polyplexes) formed by self‐assembly with siRNA were applied to overcome extracellular and intracellular barriers and deliver siRNA site‐specific. In this work we show that intraperitoneal administration of chitosan/DsiRNA nanoparticles targeting TNFα...

  18. Induction of RNA interference in dendritic cells.

    Science.gov (United States)

    Li, Mu; Qian, Hua; Ichim, Thomas E; Ge, Wei-Wen; Popov, Igor A; Rycerz, Katarzyna; Neu, John; White, David; Zhong, Robert; Min, Wei-Ping

    2004-01-01

    Dendritic cells (DC) reside at the center of the immunological universe, possessing the ability both to stimulate and inhibit various types of responses. Tolerogenic/regulatory DC with therapeutic properties can be generated through various means of manipulations in vitro and in vivo. Here we describe several attractive strategies for manipulation of DC using the novel technique of RNA interference (RNAi). Additionally, we overview some of our data regarding yet undescribed characteristics of RNAi in DC such as specific transfection strategies, persistence of gene silencing, and multi-gene silencing. The advantages of using RNAi for DC genetic manipulation gives rise to the promise of generating tailor-made DC that can be used effectively to treat a variety of immunologically mediated diseases.

  19. Using RNA Interference to Study Protein Function

    OpenAIRE

    Curtis, Carol D.; Nardulli, Ann M.

    2009-01-01

    RNA interference can be extremely useful in determining the function of an endogenously-expressed protein in its normal cellular environment. In this chapter, we describe a method that uses small interfering RNA (siRNA) to knock down mRNA and protein expression in cultured cells so that the effect of a putative regulatory protein on gene expression can be delineated. Methods of assessing the effectiveness of the siRNA procedure using real time quantitative PCR and Western analysis are also in...

  20. RNA interference targeting carbohydrate sulfotransferase 3 diminishes macrophage accumulation, inhibits MMP-9 expression and promotes lung recovery in murine pulmonary emphysema.

    Science.gov (United States)

    Kai, Yoshiro; Tomoda, Koichi; Yoneyama, Hiroyuki; Yoshikawa, Masanori; Kimura, Hiroshi

    2015-12-09

    Chondroitin sulfate proteoglycans are an important mediators in inflammation and leukocyte trafficking. However, their roles in pulmonary emphysema have not been explored. In a murine model of elastase-induced pulmonary emphysema, we found increased carbohydrate sulfotransferase 3 (CHST3), a specific enzyme that synthesizes chondroitin 6-sulfate proteoglycan (C6SPG). To elucidate the role of C6SPG, we investigated the effect of small interfering RNA (siRNA) targeting CHST3 that inhibits C6SPG-synthesis on the pathogenesis of pulmonary emphysema. Mice were intraperitoneally injected with CHST3 siRNA or negative control siRNA on day0 and 7 after intratracheal instillation of elastase. Histology, respiratory function, glycosaminoglycans (GAGs) content, bronchoalveolar lavage (BAL), elastin staining and gene expressions of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-9 mRNA were evaluated on day7 and/or day21. CHST3 mRNA increased at day 7 and decreased thereafter in lung. CHST3 siRNA successfully inhibited the expression of CHST3 mRNA throughout the study and this was associated with significant reduction of GAGs and C6SPG. Airway destruction and respiratory function were improved by the treatment with CHST3 siRNA. CHST3 siRNA reduced the number of macrophages both in BAL and lung parenchyma and also suppressed the increased expressions of TNF-α and MMP-9 mRNA. Futhermore, CHST3 siRNA improved the reduction of the elastin in the alveolar walls. CHST3 siRNA diminishes accumulation of excessive macrophages and the mediators, leading to accelerate the functional recovery from airway damage by repair of the elastin network associated with pulmonary emphysema.

  1. Inhibition of CD147 expression by RNA interference reduces proliferation, invasion and increases chemosensitivity in cancer stem cell-like HT-29 cells.

    Science.gov (United States)

    Chen, Jie; Pan, Yuqin; He, Bangshun; Ying, Houqun; Wang, Feng; Sun, Huiling; Deng, Qiwen; Liu, Xian; Lin, Kang; Peng, Hongxin; Cho, William C; Wang, Shukui

    2015-10-01

    The association between CD147 and cancer stem cells (CSCs) provides a new angle for cancer treatments. The aim of this study was to investigate the biological roles of CD147 in colorectal CSCs. The Oct4-green fluorescent protein (GFP) vector was used to isolate CSCs and pYr-mir30-shRNA was used to generate short hairpin RNA (shRNA) specifically for CD147. After RNA interference (RNAi), CD147 was evaluated by reverse transcription‑quantitative PCR and western blot analysis, and its biological functions were assessed by MTT and invasion assays. The results showed that the differentiation of isolated CSC-like HT-29 cells was blocked and these cells were highly positive for CD44 and CD147. RNAi-mediated CD147 silencing reduced the expression of CD147 at both mRNA and protein levels. Moreover, the activities of proliferation and invasion were decreased obviously in CSCs. Knockdown of CD147 increased the chemosensitivity of CSC-like cells to gemcitabine, cisplatin, docetaxel at 0.1, 1 and 10 µM respectively, however, there was no significant difference among the three groups to paclitaxel at 10 µM. In conclusion, these results suggest that CD147 plays an important role in colorectal CSCs and might be regarded as a novel CSC-specific targeted strategy against colorectal cancer.

  2. RNA interference: its use as antiviral therapy

    NARCIS (Netherlands)

    Haasnoot, J.; Berkhout, B.

    2006-01-01

    RNA interference (RNAi) is a sequence-specific gene-silencing mechanism that has been proposed to function as a defence mechanism of eukaryotic cells against viruses and transposons. RNAi was first observed in plants in the form of a mysterious immune response to viral pathogens. But RNAi is more

  3. Branched RNA: A New Architecture for RNA Interference

    Directory of Open Access Journals (Sweden)

    Anna Aviñó

    2011-01-01

    Full Text Available Branched RNAs with two and four strands were synthesized. These structures were used to obtain branched siRNA. The branched siRNA duplexes had similar inhibitory capacity as those of unmodified siRNA duplexes, as deduced from gene silencing experiments of the TNF-α protein. Branched RNAs are considered novel structures for siRNA technology, and they provide an innovative tool for specific gene inhibition. As the method described here is compatible with most RNA modifications described to date, these compounds may be further functionalized to obtain more potent siRNA derivatives and can be attached to suitable delivery systems.

  4. Study of RNA interference inhibiting rat ovarian androgen biosynthesis by depressing 17alpha-hydroxylase/17, 20-lyase activity in vivo

    Directory of Open Access Journals (Sweden)

    Yang Xing

    2009-07-01

    Full Text Available Abstract Background 17alpha-hydroxylase/17, 20-lyase encoded by CYP17 is the key enzyme in androgen biosynthesis pathway. Previous studies demonstrated the accentuation of the enzyme in patients with polycystic ovary syndrome (PCOS was the most important mechanism of androgen excess. We chose CYP17 as the therapeutic target, trying to suppress the activity of 17alpha-hydroxylase/17, 20-lyase and inhibit androgen biosynthesis by silencing the expression of CYP17 in the rat ovary. Methods Three CYP17-targeting and one negative control oligonucleotides were designed and used in the present study. The silence efficiency of lentivirus shRNA was assessed by qRT-PCR, Western blotting and hormone assay. After subcapsular injection of lentivirus shRNA in rat ovary, the delivery efficiency was evaluated by GFP fluorescence and qPCR. Total RNA was extracted from rat ovary for CYP17 mRNA determination and rat serum was collected for hormone measurement. Results In total, three CYP17-targeting lentivirus shRNAs were synthesized. The results showed that all of them had a silencing effect on CYP17 mRNA and protein. Moreover, androstenedione secreted by rat theca interstitial cells (TIC in the RNAi group declined significantly compared with that in the control group. Two weeks after rat ovarian subcapsular injection of chosen CYP17 shRNA, the GFP fluorescence of frozen ovarian sections could be seen clearly under fluorescence microscope. It also showed that the GFP DNA level increased significantly, and its relative expression level was 7.42 times higher than that in the control group. Simultaneously, shRNA treatment significantly decreased CYP17 mRNA and protein levels at 61% and 54%, respectively. Hormone assay showed that all the levels of androstenedione, 17-hydroxyprogesterone and testosterone declined to a certain degree, but progesterone levels declined significantly. Conclusion The present study proves for the first time that ovarian androgen

  5. Lentivirus mediated RNA interference of EMMPRIN (CD147) gene inhibits the proliferation, matrigel invasion and tumor formation of breast cancer cells.

    Science.gov (United States)

    Yang, Jing; Wang, Rong; Li, Hongjiang; Lv, Qing; Meng, Wentong; Yang, Xiaoqin

    2016-07-08

    Overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN) or cluster of differentiation 147 (CD147), a glycoprotein enriched on the plasma membrane of tumor cells, promotes proliferation, invasion, metastasis, and survival of malignant tumor cells. In this study, we sought to examine the expression of EMMPRIN in breast tumors, and to identify the potential roles of EMMPRIN on breast cancer cells. EMMPRIN expression in breast cancer tissues was assessed by immunohistochemistry. We used a lentivirus vector-based RNA interference (RNAi) approach expressing short hairpin RNA (shRNA) to knockdown EMMPRIN gene in breast cancer cell lines MDA-MB-231 and MCF-7. In vitro, Cell proliferative, invasive potential were determined by Cell Counting Kit (CCK-8), cell cycle analysis and matrigel invasion assay, respectively. In vivo, tumorigenicity was monitored by inoculating tumor cells into breast fat pad of female nude mice. EMMPRIN was over-expressed in breast tumors and breast cancer cell lines. Down-regulation of EMMPRIN by lentivirus vector-based RNAi led to decreased cell proliferative, decreased matrigel invasion in vitro, and attenuated tumor formation in vivo. High expression of EMMPRIN plays a crucial role in breast cancer cell proliferation, matrigel invasion and tumor formation.

  6. RNA interference and Register Machines (extended abstract

    Directory of Open Access Journals (Sweden)

    Masahiro Hamano

    2012-11-01

    Full Text Available RNA interference (RNAi is a mechanism whereby small RNAs (siRNAs directly control gene expression without assistance from proteins. This mechanism consists of interactions between RNAs and small RNAs both of which may be single or double stranded. The target of the mechanism is mRNA to be degraded or aberrated, while the initiator is double stranded RNA (dsRNA to be cleaved into siRNAs. Observing the digital nature of RNAi, we represent RNAi as a Minsky register machine such that (i The two registers hold single and double stranded RNAs respectively, and (ii Machine's instructions are interpreted by interactions of enzyme (Dicer, siRNA (with RISC com- plex and polymerization (RdRp to the appropriate registers. Interpreting RNAi as a computational structure, we can investigate the computational meaning of RNAi, especially its complexity. Initially, the machine is configured as a Chemical Ground Form (CGF, which generates incorrect jumps. To remedy this problem, the system is remodeled as recursive RNAi, in which siRNA targets not only mRNA but also the machine instructional analogues of Dicer and RISC. Finally, probabilistic termination is investigated in the recursive RNAi system.

  7. Downregulation of CD147 expression by RNA interference inhibits HT29 cell proliferation, invasion and tumorigenicity in vitro and in vivo.

    Science.gov (United States)

    Li, Rui; Pan, Yuqin; He, Bangshun; Xu, Yeqiong; Gao, Tianyi; Song, Guoqi; Sun, Huiling; Deng, Qiwen; Wang, Shukui

    2013-12-01

    We investigated the effect of CD147 silencing on HT29 cell proliferation and invasion. We constructed a novel short hairpin RNA (shRNA) expression vector pYr-mir30-shRNA. The plasmid was transferred to HT29 cells. The expression of CD147, MCT1 (lactate transporters monocarboxylate transporter 1) and MCT4 (lactate transporters monocarboxylate transporter 4) were monitored by quantitative PCR and western blotting, respectively. The MMP-2 (matrix metalloproteinase-2) and MMP-9 (matrix metalloproteinase-9) activities were determined by gelatin zymography assay, while the intracellular lactate concentration was determined by the lactic acid assay kit. WST-8 assay was used to determine the HT29 cell proliferation and the chemosensitivity. Invasion assay was used to determine the invasion of HT29 cells. In addition, we established a colorectal cancer model, and detected CD147 expression in vivo. The results showed that the expression of CD147 and MCT1 was significantly reduced at both mRNA and protein levels, and also the activity of MMP-2 and MMP-9 was reduced. The proliferation and invasion were decreased, but chemosensitivity to cisplatin was increased. In vivo, the CD147 expression was also significantly decreased, and reduced the tumor growth after CD147 gene silencing. The results demonstrated that silencing of CD147 expression inhibited the proliferation and invasion, suggesting CD147 silencing might be an adjuvant gene therapy strategy to chemotherapy.

  8. RNA interference in designing transgenic crops.

    Science.gov (United States)

    Ali, Nusrat; Datta, Swapan K; Datta, Karabi

    2010-01-01

    RNA interference (RNAi) is a sequence specific gene silencing mechanism, triggered by the introduction of dsRNA leading to mRNA degradation. It helps in switching on and off the targeted gene, which might have significant impact in developmental biology. Discovery of RNAi represents one of the most promising and rapidly advancing frontiers in plant functional genomics and in crop improvement by plant metabolic engineering and also plays an important role in reduction of allergenicity by silencing specific plant allergens. In plants the RNAi technology has been employed successfully in improvement of several plant species- by increasing their nutritional value, overall quality and by conferring resistance against pathogens and diseases. The review gives an insight to the perspective use of the technology in designing crops with innovation, to bring improvement to crop productivity and quality.

  9. RNA interference-mediated c-MYC inhibition prevents cell growth and decreases sensitivity to radio- and chemotherapy in childhood medulloblastoma cells

    International Nuclear Information System (INIS)

    Bueren, André O von; Shalaby, Tarek; Oehler-Jänne, Christoph; Arnold, Lucia; Stearns, Duncan; Eberhart, Charles G; Arcaro, Alexandre; Pruschy, Martin; Grotzer, Michael A

    2009-01-01

    With current treatment strategies, nearly half of all medulloblastoma (MB) patients die from progressive tumors. Accordingly, the identification of novel therapeutic strategies remains a major goal. Deregulation of c-MYC is evident in numerous human cancers. In MB, over-expression of c-MYC has been shown to cause anaplasia and correlate with unfavorable prognosis. To study the role of c-MYC in MB biology, we down-regulated c-MYC expression by using small interfering RNA (siRNA) and investigated changes in cellular proliferation, cell cycle analysis, apoptosis, telomere maintenance, and response to ionizing radiation (IR) and chemotherapeutics in a representative panel of human MB cell lines expressing different levels of c-MYC (DAOY wild-type, DAOY transfected with the empty vector, DAOY transfected with c-MYC, D341, and D425). siRNA-mediated c-MYC down-regulation resulted in an inhibition of cellular proliferation and clonogenic growth, inhibition of G1-S phase cell cycle progression, and a decrease in human telomerase reverse transcriptase (hTERT) expression and telomerase activity. On the other hand, down-regulation of c-MYC reduced apoptosis and decreased the sensitivity of human MB cells to IR, cisplatin, and etoposide. This effect was more pronounced in DAOY cells expressing high levels of c-MYC when compared with DAOY wild-type or DAOY cells transfected with the empty vector. In human MB cells, in addition to its roles in growth and proliferation, c-MYC is also a potent inducer of apoptosis. Therefore, targeting c-MYC might be of therapeutic benefit when used sequentially with chemo- and radiotherapy rather than concomitantly

  10. RNA interference-mediated c-MYC inhibition prevents cell growth and decreases sensitivity to radio- and chemotherapy in childhood medulloblastoma cells

    Directory of Open Access Journals (Sweden)

    Arcaro Alexandre

    2009-01-01

    Full Text Available Abstract Background With current treatment strategies, nearly half of all medulloblastoma (MB patients die from progressive tumors. Accordingly, the identification of novel therapeutic strategies remains a major goal. Deregulation of c-MYC is evident in numerous human cancers. In MB, over-expression of c-MYC has been shown to cause anaplasia and correlate with unfavorable prognosis. Methods To study the role of c-MYC in MB biology, we down-regulated c-MYC expression by using small interfering RNA (siRNA and investigated changes in cellular proliferation, cell cycle analysis, apoptosis, telomere maintenance, and response to ionizing radiation (IR and chemotherapeutics in a representative panel of human MB cell lines expressing different levels of c-MYC (DAOY wild-type, DAOY transfected with the empty vector, DAOY transfected with c-MYC, D341, and D425. Results siRNA-mediated c-MYC down-regulation resulted in an inhibition of cellular proliferation and clonogenic growth, inhibition of G1-S phase cell cycle progression, and a decrease in human telomerase reverse transcriptase (hTERT expression and telomerase activity. On the other hand, down-regulation of c-MYC reduced apoptosis and decreased the sensitivity of human MB cells to IR, cisplatin, and etoposide. This effect was more pronounced in DAOY cells expressing high levels of c-MYC when compared with DAOY wild-type or DAOY cells transfected with the empty vector. Conclusion In human MB cells, in addition to its roles in growth and proliferation, c-MYC is also a potent inducer of apoptosis. Therefore, targeting c-MYC might be of therapeutic benefit when used sequentially with chemo- and radiotherapy rather than concomitantly.

  11. RNA interference: learning gene knock-down from cell physiology

    Directory of Open Access Journals (Sweden)

    Provenzano Maurizio

    2004-11-01

    Full Text Available Summary Over the past decade RNA interference (RNAi has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design.

  12. RNA interference: learning gene knock-down from cell physiology

    Science.gov (United States)

    Mocellin, Simone; Provenzano, Maurizio

    2004-01-01

    Over the past decade RNA interference (RNAi) has emerged as a natural mechanism for silencing gene expression. This ancient cellular antiviral response can be exploited to allow specific inhibition of the function of any chosen target gene. RNAi is proving to be an invaluable research tool, allowing much more rapid characterization of the function of known genes. More importantly, RNAi technology considerably bolsters functional genomics to aid in the identification of novel genes involved in disease processes. This review briefly describes the molecular principles underlying the biology of RNAi phenomenon and discuss the main technical issues regarding optimization of RNAi experimental design. PMID:15555080

  13. RNA interference: ready to silence cancer?

    Science.gov (United States)

    Mocellin, Simone; Costa, Rodolfo; Nitti, Donato

    2006-01-01

    RNA interference (RNAi) is considered the most promising functional genomics tool recently developed. As in other medical fields, this biotechnology might revolutionize the approach to dissecting the biology of cancer, ultimately speeding up the discovery pace of novel targets suitable for molecularly tailored antitumor therapies. In addition, preclinical results suggest that RNAi itself might be used as a therapeutic weapon. With the aim of illustrating not only the potentials but also the current limitations of RNAi as a tool in the fight against cancer, here we summarize the physiology of RNAi, discuss the main technical issues of RNAi-based gene silencing, and review some of the most interesting preclinical results obtained so far with its implementation in the field of oncology.

  14. Role of RNA interference in plant improvement.

    Science.gov (United States)

    Jagtap, Umesh Balkrishna; Gurav, Ranjit Gajanan; Bapat, Vishwas Anant

    2011-06-01

    Research to alter crops for their better performance involving modern technology is underway in numerous plants, and achievements in transgenic plants are impacting crop improvements in unparalleled ways. Striking progress has been made using genetic engineering technology over the past two decades in manipulating genes from diverse and exotic sources, and inserting them into crop plants for inducing desirable characteristics. RNA interference (RNAi) has recently been identified as a natural mechanism for regulation of gene expression in all higher organisms from plants to humans and promises greater accuracy and precision to plant improvement. The expression of any gene can be down-regulated in a highly explicit manner exclusive of affecting the expression of any other gene by using RNAi technologies. Additional research in this field has been focused on a number of other areas including microRNAs, hairpin RNA, and promoter methylation. Manipulating new RNAi pathways, which generate small RNA molecules to amend gene expression in crops, can produce new quality traits and having better potentiality of protection against abiotic and biotic stresses. Nutritional improvement, change in morphology, or enhanced secondary metabolite synthesis are some of the other advantages of RNAi technology. In addition to its roles in regulating gene expression, RNAi is also used as a natural defense mechanism against molecular parasites such as jumping genes and viral genetic elements that affect genome stability. Even though much advancement has been made on the field of RNAi over the preceding few years, the full prospective of RNAi for crop improvement remains to be fully realized. The intricacy of RNAi pathway, the molecular machineries, and how it relates to plant development are still to be explained.

  15. Role of RNA interference in plant improvement

    Science.gov (United States)

    Jagtap, Umesh Balkrishna; Gurav, Ranjit Gajanan; Bapat, Vishwas Anant

    2011-06-01

    Research to alter crops for their better performance involving modern technology is underway in numerous plants, and achievements in transgenic plants are impacting crop improvements in unparalleled ways. Striking progress has been made using genetic engineering technology over the past two decades in manipulating genes from diverse and exotic sources, and inserting them into crop plants for inducing desirable characteristics. RNA interference (RNAi) has recently been identified as a natural mechanism for regulation of gene expression in all higher organisms from plants to humans and promises greater accuracy and precision to plant improvement. The expression of any gene can be down-regulated in a highly explicit manner exclusive of affecting the expression of any other gene by using RNAi technologies. Additional research in this field has been focused on a number of other areas including microRNAs, hairpin RNA, and promoter methylation. Manipulating new RNAi pathways, which generate small RNA molecules to amend gene expression in crops, can produce new quality traits and having better potentiality of protection against abiotic and biotic stresses. Nutritional improvement, change in morphology, or enhanced secondary metabolite synthesis are some of the other advantages of RNAi technology. In addition to its roles in regulating gene expression, RNAi is also used as a natural defense mechanism against molecular parasites such as jumping genes and viral genetic elements that affect genome stability. Even though much advancement has been made on the field of RNAi over the preceding few years, the full prospective of RNAi for crop improvement remains to be fully realized. The intricacy of RNAi pathway, the molecular machineries, and how it relates to plant development are still to be explained.

  16. Short hairpin RNA interference therapy for ischemic heart disease

    Science.gov (United States)

    Huang, Mei; Chan, Denise; Jia, Fangjun; Xie, Xiaoyan; Li, Zongjin; Hoyt, Grant; Robbins, Robert C.; Chen, Xiaoyuan; Giaccia, Amato; Wu, Joseph C.

    2013-01-01

    Background During hypoxia, upregulation of hypoxia inducible factor-1 alpha (HIF-1α) transcriptional factor can activate several downstream angiogenic genes. However, HIF-1α is naturally degraded by prolyl hydroxylase-2 (PHD2) protein. Here we hypothesize that short hairpin RNA (shRNA) interference therapy targeting PHD2 can be used for treatment of myocardial ischemia and this process can be followed noninvasively by molecular imaging. Methods and Results PHD2 was cloned from mouse embryonic stem (ES) cells by comparing the homolog gene in human and rat. The best candidate shRNA sequence for inhibiting PHD2 was inserted into the pSuper vector driven by the H1 promoter, followed by a separate hypoxia response element (HRE)-incorporated promoter driving a firefly luciferase (Fluc) reporter gene. This construct was used to transfect mouse C2C12 myoblast cell line for in vitro confirmation. Compared to the control short hairpin scramble (shScramble) as control, inhibition of PHD2 increased levels of HIF-1α protein and several downstream angiogenic genes by >30% (P<0.01). Afterwards, shRNA targeting PHD2 (shPHD2) plasmid was injected intramyocardially following ligation of left anterior descending (LAD) artery in mice. Animals were randomized into shPHD2 group (n=20) versus shScramble sequence as control (n=20). Bioluminescence imaging detected transgene expression for 4–5 weeks. Echocardiographic study showed the shPHD2 group had improved fractional shortening compared with the shScramble group at week 4 (33.7%±1.9% vs. 28.4%±2.8%; P<0.05). Postmortem analysis showed increased presence of small capillaries and venules in the infarcted zones by CD31 staining. Finally, Western blot anlaysis of explanted hearts also confirm that animals treated with shPHD2 had significantly higher levels of HIF-1α protein. Conclusions This is the first study to image the biological role of shRNA therapy for improving cardiac function. Inhibition of PHD2 by shRNA led to

  17. RNA interference targets arbovirus replication in Culicoides cells.

    Science.gov (United States)

    Schnettler, Esther; Ratinier, Maxime; Watson, Mick; Shaw, Andrew E; McFarlane, Melanie; Varela, Mariana; Elliott, Richard M; Palmarini, Massimo; Kohl, Alain

    2013-03-01

    Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses.

  18. RNA interference targeting CD147 inhibits the proliferation, invasiveness, and metastatic activity of thyroid carcinoma cells by down-regulating glycolysis

    Science.gov (United States)

    Huang, Peng; Chang, Shi; Jiang, Xiaolin; Su, Juan; Dong, Chao; Liu, Xu; Yuan, Zhengtai; Zhang, Zhipeng; Liao, Huijun

    2015-01-01

    A high rate of glycolytic flux, even in the presence of oxygen, is a key metabolic hallmark of cancer cells. Lactate, the end product of glycolysis, decreases the extracellular pH and contributes to the proliferation, invasiveness and metastasis of tumor cells. CD147 play a crucial role in tumorigenicity, invasion and metastasis; and CD147 also interacts strongly and specifically with monocarboxylate transporter1 (MCT1) that mediates the transport of lactate. The objective of this study was to determine whether CD147 is involved, via its association with MCT1 to transport lactate, in glycolysis, contributing to the progression of thyroid carcinoma. The expression levels of CD147 in surgical specimens of normal thyroid, nodular goiter (NG), well-differentiated thyroid carcinoma (WDTC), and undifferentiated thyroid carcinoma (UDTC) were determined using immunohistochemical techniques. The effects of CD147 silencing on cell proliferation, invasiveness, metastasis, co-localization with MCT1, glycolysis rate and extracellular pH of thyroid cancer cells (WRO and FRO cell lines) were measured after CD147 was knocked-down using siRNA targeting CD147. Immunohistochemical analysis of thyroid carcinoma (TC) tissues revealed significant increases in signal for CD147 compared with normal tissue or NG, while UDTC expressed remarkably higher levels of CD147 compared with WDTC. Furthermore, silencing of CD147 in TC cells clearly abrogated the expression of MCT1 and its co-localization with CD147 and dramatically decreased both the glycolysis rate and extracellular pH. Thus, cell proliferation, invasiveness, and metastasis were all significantly decreased by siRNA. These results demonstrate in vitro that the expression of CD147 correlates with the degree of dedifferentiation of thyroid cancer, and show that CD147 interacts with MCT1 to regulate tumor cell glycolysis, resulting in the progression of thyroid carcinoma. PMID:25755717

  19. RNA interference of pheromone biosynthesis-activating neuropeptide receptor suppresses mating behavior by inhibiting sex pheromone production in Plutella xylostella (L.).

    Science.gov (United States)

    Lee, Dae-Weon; Shrestha, Sony; Kim, A Young; Park, Seok Joo; Yang, Chang Yeol; Kim, Yonggyun; Koh, Young Ho

    2011-04-01

    Sex pheromone production is regulated by pheromone biosynthesis-activating neuropeptide (PBAN) in many lepidopteran species. We cloned a PBAN receptor (Plx-PBANr) gene from the female pheromone gland of the diamondback moth, Plutella xylostella (L.). Plx-PBANr encodes 338 amino acids and has conserved structural motifs implicating in promoting G protein coupling and tyrosine-based sorting signaling along with seven transmembrane domains, indicating a typical G protein-coupled receptor. The expression of Plx-PBANr was found only in the pheromone gland of female adults among examined tissues and developmental stages. Heterologous expression in human uterus cervical cancer cells revealed that Plx-PBANr induced significant calcium elevation when challenged with Plx-PBAN. Female P. xylostella injected with double-stranded RNA specific to Plx-PBANr showed suppression of the receptor gene expression and exhibited significant reduction in pheromone biosynthesis, which resulted in loss of male attractiveness. Taken together, the identified PBAN receptor is functional in PBAN signaling via calcium secondary messenger, which leads to activation of pheromone biosynthesis and male attraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Role of RNA interference (RNAi) in the moss Physcomitrella patens

    KAUST Repository

    Arif, Muhammad Asif; Frank, Wolfgang; Khraiwesh, Basel

    2013-01-01

    RNA interference (RNAi) is a mechanism that regulates genes by either transcriptional (TGS) or posttranscriptional gene silencing (PTGS), required for genome maintenance and proper development of an organism. Small non-coding RNAs are the key players in RNAi and have been intensively studied in eukaryotes. In plants, several classes of small RNAs with specific sizes and dedicated functions have evolved. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs are synthesized from a short hairpin structure while siRNAs are derived from long double-stranded RNAs (dsRNA). Both miRNA and siRNAs control the expression of cognate target RNAs by binding to reverse complementary sequences mediating cleavage or translational inhibition of the target RNA. They also act on the DNA and cause epigenetic changes such as DNA methylation and histone modifications. In the last years, the analysis of plant RNAi pathways was extended to the bryophyte Physcomitrella patens, a non-flowering, non-vascular ancient land plant that diverged from the lineage of seed plants approximately 450 million years ago. Based on a number of characteristic features and its phylogenetic key position in land plant evolution P. patens emerged as a plant model species to address basic as well as applied topics in plant biology. Here we summarize the current knowledge on the role of RNAi in P. patens that shows functional overlap with RNAi pathways from seed plants, and also unique features specific to this species. 2013 by the authors; licensee MDPI, Basel, Switzerland.

  1. Role of RNA interference (RNAi) in the moss Physcomitrella patens

    KAUST Repository

    Arif, Muhammad Asif

    2013-01-14

    RNA interference (RNAi) is a mechanism that regulates genes by either transcriptional (TGS) or posttranscriptional gene silencing (PTGS), required for genome maintenance and proper development of an organism. Small non-coding RNAs are the key players in RNAi and have been intensively studied in eukaryotes. In plants, several classes of small RNAs with specific sizes and dedicated functions have evolved. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs are synthesized from a short hairpin structure while siRNAs are derived from long double-stranded RNAs (dsRNA). Both miRNA and siRNAs control the expression of cognate target RNAs by binding to reverse complementary sequences mediating cleavage or translational inhibition of the target RNA. They also act on the DNA and cause epigenetic changes such as DNA methylation and histone modifications. In the last years, the analysis of plant RNAi pathways was extended to the bryophyte Physcomitrella patens, a non-flowering, non-vascular ancient land plant that diverged from the lineage of seed plants approximately 450 million years ago. Based on a number of characteristic features and its phylogenetic key position in land plant evolution P. patens emerged as a plant model species to address basic as well as applied topics in plant biology. Here we summarize the current knowledge on the role of RNAi in P. patens that shows functional overlap with RNAi pathways from seed plants, and also unique features specific to this species. 2013 by the authors; licensee MDPI, Basel, Switzerland.

  2. RNA interference in plant parasitic nematodes

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... grower preference or by government restrictions to limit the environmental ... risks associated with chemical control and (c) the pro- vision of ... certain model organisms. The first ... reproductive system (Lilley et al., 2005b), sperm (Urwin .... interference of dual oxidase in the plant nematode Meloidogyne.

  3. RNA interference: concept to reality in crop improvement.

    Science.gov (United States)

    Saurabh, Satyajit; Vidyarthi, Ambarish S; Prasad, Dinesh

    2014-03-01

    The phenomenon of RNA interference (RNAi) is involved in sequence-specific gene regulation driven by the introduction of dsRNA resulting in inhibition of translation or transcriptional repression. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in opening a new vista for crop improvement. RNAi technology is precise, efficient, stable and better than antisense technology. It has been employed successfully to alter the gene expression in plants for better quality traits. The impact of RNAi to improve the crop plants has proved to be a novel approach in combating the biotic and abiotic stresses and the nutritional improvement in terms of bio-fortification and bio-elimination. It has been employed successfully to bring about modifications of several desired traits in different plants. These modifications include nutritional improvements, reduced content of food allergens and toxic compounds, enhanced defence against biotic and abiotic stresses, alteration in morphology, crafting male sterility, enhanced secondary metabolite synthesis and seedless plant varieties. However, crop plants developed by RNAi strategy may create biosafety risks. So, there is a need for risk assessment of GM crops in order to make RNAi a better tool to develop crops with biosafety measures. This article is an attempt to review the RNAi, its biochemistry, and the achievements attributed to the application of RNAi in crop improvement.

  4. RNA Interference - Towards RNA becoming a Medicine -42 ...

    Indian Academy of Sciences (India)

    research. A brief history of the development ofRNAi is shown in. Box 2. Mechanism of ... new RNA strand using target RNA as the template and thereby converting it ... thought to excise precursor stRNA from their -70 nt stem loop precursor to ...

  5. RNA Interference and its therapeutic applications

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao T

    2011-10-01

    Full Text Available RNAi is a potent method, requiring only a few molecules of dsRNA per cell to silence the expression. Long molecules of double stranded RNA (dsRNA trigger the process. The dsRNA comes from virus and transposon activity in natural RNAi process, while it can be injected in the cells in experimental processes. The strand of the dsRNA that is identical in sequence to a region in target mRNA molecule is called the sense strand, and the other strand which is complimentary is termed the antisense strand. An enzyme complex called DICER thought to be similar to RNAase III then recognizes dsRNA, and cuts it into roughly 22- nucleotide long fragments. These fragments termed siRNAs for “small interfering RNAs” remain in double stranded duplexes with very short 3' overhangs. However, only one of the two strands, known as the guide strand or antisense strand binds the argonaute protein of RNA-induced silencing complex (RISC and target the complementary mRNA resulting gene silencing. The other anti-guide strand or passenger strand is degraded as a RISC substrate during the process of RISC activation. This form of RNAi is termed as post transcriptional gene silencing (PTGS; other forms are also thought to operate at the genomic or transcriptional level in some organisms. In mammals dsRNA longer than 30 base pairs induces a nonspecific antiviral response. This so-called interferon response results in a nonspecific arrest in translation and induction of apoptosis. This cascade induces a global non-specific suppression of translation, which in turn triggers apoptosis. Interestingly, dsRNAs less than 30 nt in length do not activate the antiviral response and specifically switched off genes in human cells without initiating the acute phase response. Thus these siRNAs are suitable for gene target validation and therapeutic applications in many species, including humans. [Vet. World 2011; 4(5.000: 225-229

  6. RNA interference-mediated intrinsic antiviral immunity in invertebrates.

    Science.gov (United States)

    Nayak, Arabinda; Tassetto, Michel; Kunitomi, Mark; Andino, Raul

    2013-01-01

    In invertebrates such as insects and nematodes, RNA interference (RNAi) provides RNA-based protection against viruses. This form of immunity restricts viral replication and dissemination from infected cells and viruses, in turn, have evolved evasion mechanisms or RNAi suppressors to counteract host defenses. Recent advances indicate that, in addition to RNAi, other related small RNA pathways contribute to antiviral functions in invertebrates. This has led to a deeper understanding of fundamental aspects of small RNA-based antiviral immunity in invertebrates and its contribution to viral spread and pathogenesis.

  7. Neuron-specific RNA interference using lentiviral vectors

    DEFF Research Database (Denmark)

    Nielsen, Troels Tolstrup; Marion, Ingrid van; Hasholt, Lis

    2009-01-01

    BACKGROUND: Viral vectors have been used in several different settings for the delivery of small hairpin (sh) RNAs. However, most vectors have utilized ubiquitously-expressing polymerase (pol) III promoters to drive expression of the hairpin as a result of the strict requirement for precise...... transcriptional initiation and termination. Recently, pol II promoters have been used to construct vectors for RNA interference (RNAi). By embedding the shRNA into a micro RNA-context (miRNA) the endogenous miRNA processing machinery is exploited to achieve the mature synthetic miRNA (smiRNA), thereby expanding...... the possible promoter choices and eventually allowing cell type specific down-regulation of target genes. METHODS: In the present study, we constructed lentiviral vectors expressing smiRNAs under the control of pol II promoters to knockdown gene expression in cell culture and in the brain. RESULTS: We...

  8. Prokaryotic Argonautes - variations on the RNA interference theme

    Science.gov (United States)

    van der Oost, John; Swarts, Daan C.; Jore, Matthijs M.

    2014-01-01

    The discovery of RNA interference (RNAi) has been a major scientific breakthrough. This RNA-guided RNA interference system plays a crucial role in a wide range of regulatory and defense mechanisms in eukaryotes. The key enzyme of the RNAi system is Argonaute (Ago), an endo-ribonuclease that uses a small RNA guide molecule to specifically target a complementary RNA transcript. Two functional classes of eukaryotic Ago have been described: catalytically active Ago that cleaves RNA targets complementary to its guide, and inactive Ago that uses its guide to bind target RNA to down-regulate translation efficiency. A recent comparative genomics study has revealed that Argonaute-like proteins are also encoded by prokaryotic genomes. Interestingly, there is a lot of variation among these prokaryotic Argonaute (pAgo) proteins with respect to domain architecture: some resemble the eukaryotic Ago (long pAgo) containing a complete or disrupted catalytic site, while others are truncated versions (short pAgo) that generally contain an incomplete catalytic site. Prokaryotic Agos with an incomplete catalytic site often co-occur with (predicted) nucleases. Based on this diversity, and on the fact that homologs of other RNAi-related protein components (such as Dicer nucleases) have never been identified in prokaryotes, it has been predicted that variations on the eukaryotic RNAi theme may occur in prokaryotes. PMID:28357239

  9. The rde-1 gene, RNA interference, and transposon silencing in C. elegans.

    Science.gov (United States)

    Tabara, H; Sarkissian, M; Kelly, W G; Fleenor, J; Grishok, A; Timmons, L; Fire, A; Mello, C C

    1999-10-15

    Double-stranded (ds) RNA can induce sequence-specific inhibition of gene function in several organisms. However, both the mechanism and the physiological role of the interference process remain mysterious. In order to study the interference process, we have selected C. elegans mutants resistant to dsRNA-mediated interference (RNAi). Two loci, rde-1 and rde-4, are defined by mutants strongly resistant to RNAi but with no obvious defects in growth or development. We show that rde-1 is a member of the piwi/sting/argonaute/zwille/eIF2C gene family conserved from plants to vertebrates. Interestingly, several, but not all, RNAi-deficient strains exhibit mobilization of the endogenous transposons. We discuss implications for the mechanism of RNAi and the possibility that one natural function of RNAi is transposon silencing.

  10. RNA interference prevents lipopolysaccharide-induced preprotachykinin gene expression

    International Nuclear Information System (INIS)

    Lai, Y.-L.; Yu, S.C.; Chen, M.-J.

    2003-01-01

    We showed previously that lipopolysaccharide (LPS) induces noncholinergic airway hyperreactivity to capsaicin via an upregulation of tachykinin synthesis. This study was designed to test whether double-stranded preprotachykinin (ds PPT) RNA, RNA interference (RNAi), prevents the LPS-induced alterations. First, cultured primary nodose ganglial cells of newborn Brown-Norway rats were divided into four groups: control; LPS; LPS+RNAi; and LPS+RNAi+liposome. Second, young Brown-Norway rats for the in vivo study were divided into three groups (control; LPS; and LPS+RNAi), and ds PPT RNA was microinjected bilaterally into the nodose ganglia in the LPS+RNAi group. Then, ganglial cells were collected from the culture whereas the nodose ganglia and lungs were sampled from the animals, and PPT mRNA and substance P (SP) levels were analyzed. Also, airway reactivity to capsaicin was performed in vivo. LPS induced significant increases in PPT mRNA and SP levels in vitro and in vivo and an increase in airway reactivity to capsaicin in vivo. However, ds PPT RNA, but not scrambled RNA, prevented all LPS-induced alterations. The effect of ds PPT RNA was not enhanced by liposome in vitro. Therefore, we demonstrated that the local application of RNAi prevents effectively the activation of the noncholinergic system modulating the lungs/airways

  11. Small Molecule Modifiers of the microRNA and RNA Interference Pathway

    OpenAIRE

    Deiters, Alexander

    2009-01-01

    Recently, the RNA interference (RNAi) pathway has become the target of small molecule inhibitors and activators. RNAi has been well established as a research tool in the sequence-specific silencing of genes in eukaryotic cells and organisms by using exogenous, small, double-stranded RNA molecules of approximately 20 nucleotides. Moreover, a recently discovered post-transcriptional gene regulatory mechanism employs microRNAs (miRNAs), a class of endogenously expressed small RNA molecules, whic...

  12. Domain motions of Argonaute, the catalytic engine of RNA interference

    Directory of Open Access Journals (Sweden)

    Wall Michael E

    2007-11-01

    Full Text Available Abstract Background The Argonaute protein is the core component of the RNA-induced silencing complex, playing the central role of cleaving the mRNA target. Visual inspection of static crystal structures already has enabled researchers to suggest conformational changes of Argonaute that might occur during RNA interference. We have taken the next step by performing an all-atom normal mode analysis of the Pyrococcus furiosus and Aquifex aeolicus Argonaute crystal structures, allowing us to quantitatively assess the feasibility of these conformational changes. To perform the analysis, we begin with the energy-minimized X-ray structures. Normal modes are then calculated using an all-atom molecular mechanics force field. Results The analysis reveals low-frequency vibrations that facilitate the accommodation of RNA duplexes – an essential step in target recognition. The Pyrococcus furiosus and Aquifex aeolicus Argonaute proteins both exhibit low-frequency torsion and hinge motions; however, differences in the overall architecture of the proteins cause the detailed dynamics to be significantly different. Conclusion Overall, low-frequency vibrations of Argonaute are consistent with mechanisms within the current reaction cycle model for RNA interference.

  13. RNA Interference in Insect Vectors for Plant Viruses

    OpenAIRE

    Kanakala, Surapathrudu; Ghanim, Murad

    2016-01-01

    Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests...

  14. Disruption of Specific RNA-RNA Interactions in a Double-Stranded RNA Virus Inhibits Genome Packaging and Virus Infectivity.

    Science.gov (United States)

    Fajardo, Teodoro; Sung, Po-Yu; Roy, Polly

    2015-12-01

    Bluetongue virus (BTV) causes hemorrhagic disease in economically important livestock. The BTV genome is organized into ten discrete double-stranded RNA molecules (S1-S10) which have been suggested to follow a sequential packaging pathway from smallest to largest segment during virus capsid assembly. To substantiate and extend these studies, we have investigated the RNA sorting and packaging mechanisms with a new experimental approach using inhibitory oligonucleotides. Putative packaging signals present in the 3'untranslated regions of BTV segments were targeted by a number of nuclease resistant oligoribonucleotides (ORNs) and their effects on virus replication in cell culture were assessed. ORNs complementary to the 3' UTR of BTV RNAs significantly inhibited virus replication without affecting protein synthesis. Same ORNs were found to inhibit complex formation when added to a novel RNA-RNA interaction assay which measured the formation of supramolecular complexes between and among different RNA segments. ORNs targeting the 3'UTR of BTV segment 10, the smallest RNA segment, were shown to be the most potent and deletions or substitution mutations of the targeted sequences diminished the RNA complexes and abolished the recovery of viable viruses using reverse genetics. Cell-free capsid assembly/RNA packaging assay also confirmed that the inhibitory ORNs could interfere with RNA packaging and further substitution mutations within the putative RNA packaging sequence have identified the recognition sequence concerned. Exchange of 3'UTR between segments have further demonstrated that RNA recognition was segment specific, most likely acting as part of the secondary structure of the entire genomic segment. Our data confirm that genome packaging in this segmented dsRNA virus occurs via the formation of supramolecular complexes formed by the interaction of specific sequences located in the 3' UTRs. Additionally, the inhibition of packaging in-trans with inhibitory ORNs

  15. RNA interference for performance enhancement and detection in doping control.

    Science.gov (United States)

    Kohler, Maxie; Schänzer, Wilhelm; Thevis, Mario

    2011-10-01

    RNA interference represents a comparably new route of regulating and manipulating specific gene expression. Promising results were obtained in experimental therapies aim at the treatment of different kinds of diseases including cancer, diabetes mellitus or Dychenne muscular dystrophy. While studies on down-regulation efficiency are often performed by analyzing the regulated protein, the direct detection of small, interfering RNA molecules and antisense oligonucleotides is of great interest for the investigation of the metabolism and degradation and also for the detection of a putative misuse of these molecules in sports. Myostatin down-regulation was shown to result in increased performance and muscle growth and the regulation of several other proteins could be relevant for performance enhancement. This mini-review summarizes current approaches for the mass spectrometric analysis of siRNA and antisense oligonucleotides from biological matrices and the available data on biodistribution, metabolism, and half-life of relevant substances are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

  16. Global effects of the CSR-1 RNA interference pathway on the transcriptional landscape.

    Science.gov (United States)

    Cecere, Germano; Hoersch, Sebastian; O'Keeffe, Sean; Sachidanandam, Ravi; Grishok, Alla

    2014-04-01

    Argonaute proteins and their small RNA cofactors short interfering RNAs are known to inhibit gene expression at the transcriptional and post-transcriptional levels. In Caenorhabditis elegans, the Argonaute CSR-1 binds thousands of endogenous siRNAs (endo-siRNAs) that are antisense to germline transcripts. However, its role in gene expression regulation remains controversial. Here we used genome-wide profiling of nascent RNA transcripts and found that the CSR-1 RNA interference pathway promoted sense-oriented RNA polymerase II transcription. Moreover, a loss of CSR-1 function resulted in global increase in antisense transcription and ectopic transcription of silent chromatin domains, which led to reduced chromatin incorporation of centromere-specific histone H3. On the basis of these findings, we propose that the CSR-1 pathway helps maintain the directionality of active transcription, thereby propagating the distinction between transcriptionally active and silent genomic regions.

  17. Inhibition of RNA Helicases of ssRNA+ Virus Belonging to Flaviviridae, Coronaviridae and Picornaviridae Families

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    Irene Briguglio

    2011-01-01

    Full Text Available Many viral pathogens encode the motor proteins named RNA helicases which display various functions in genome replication. General strategies to design specific and selective drugs targeting helicase for the treatment of viral infections could act via one or more of the following mechanisms: inhibition of the NTPase activity, by interferences with ATP binding and therefore by limiting the energy required for the unwinding and translocation, or by allosteric mechanism and therefore by stabilizing the conformation of the enzyme in low helicase activity state; inhibition of nucleic acids binding to the helicase; inhibition of coupling of ATP hydrolysis to unwinding; inhibition of unwinding by sterically blocking helicase translocation. Recently, by in vitro screening studies, it has been reported that several benzotriazole, imidazole, imidazodiazepine, phenothiazine, quinoline, anthracycline, triphenylmethane, tropolone, pyrrole, acridone, small peptide, and Bananin derivatives are endowed with helicase inhibition of pathogen viruses belonging to Flaviviridae, Coronaviridae, and Picornaviridae families.

  18. RNA Interference in Moths: Mechanisms, Applications, and Progress

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    Jin Xu

    2016-10-01

    Full Text Available The vast majority of lepidopterans, about 90%, are moths. Some moths, particularly their caterpillars, are major agricultural and forestry pests in many parts of the world. However, some other members of moths, such as the silkworm Bombyx mori, are famous for their economic value. Fire et al. in 1998 initially found that exogenous double-stranded RNA (dsRNA can silence the homolog endogenous mRNA in organisms, which is called RNA interference (RNAi. Soon after, the RNAi technique proved to be very promising not only in gene function determination but also in pest control. However, later studies demonstrate that performing RNAi in moths is not as straightforward as shown in other insect taxa. Nevertheless, since 2007, especially after 2010, an increasing number of reports have been published that describe successful RNAi experiments in different moth species either on gene function analysis or on pest management exploration. So far, more than 100 peer-reviewed papers have reported successful RNAi experiments in moths, covering 10 families and 25 species. By using classic and novel dsRNA delivery methods, these studies effectively silence the expression of various target genes and determine their function in larval development, reproduction, immunology, resistance against chemicals, and other biological processes. In addition, a number of laboratory and field trials have demonstrated that RNAi is also a potential strategy for moth pest management. In this review, therefore, we summarize and discuss the mechanisms and applications of the RNAi technique in moths by focusing on recent progresses.

  19. Specific RNA Interference in Caenorhabditis elegans by Ingested dsRNA Expressed in Bacillus subtilis

    NARCIS (Netherlands)

    Lezzerini, M.; van de Ven, K.; Veerman, M.; Brul, S.; Budovskaya, Y.V.

    2015-01-01

    In nematodes, genome-wide RNAi-screening has been widely used as a rapid and efficient method to identify genes involved in the aging processes. By far the easiest way of inducing RNA interference (RNAi) in Caenorhabditis elegans is by feeding Escherichia coli that expresses specific double stranded

  20. Maturation of cognitive control: delineating response inhibition and interference suppression.

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    Christopher R Brydges

    Full Text Available Cognitive control is integral to the ability to attend to a relevant task whilst suppressing distracting information or inhibiting prepotent responses. The current study examined the development of these two subprocesses by examining electrophysiological indices elicited during each process. Thirteen 18 year-old adults and thirteen children aged 8-11 years (mean=9.77 years completed a hybrid Go/Nogo flanker task while continuous EEG data were recorded. The N2 topography for both response inhibition and interference suppression changed with increasing age. The neural activation associated with response inhibition became increasingly frontally distributed with age, and showed decreases of both amplitude and peak latency from childhood to adulthood, possibly due to reduced cognitive demands and myelination respectively occurring during this period. Interestingly, a significant N2 effect was apparent in adults, but not observed in children during trials requiring interference suppression. This could be due to more diffuse activation in children, which would require smaller levels of activation over a larger region of the brain than is reported in adults. Overall, these results provide evidence of distinct maturational processes occurring throughout late childhood and adolescence, highlighting the separability of response inhibition and interference suppression.

  1. Dengue virus type 2 infections of Aedes aegypti are modulated by the mosquito's RNA interference pathway.

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    Irma Sánchez-Vargas

    2009-02-01

    Full Text Available A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi, is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA, which occurs in the cytoplasm as a result of positive-sense RNA virus infection, leading to production of small interfering RNAs (siRNAs. These siRNAs are instrumental in degradation of viral mRNA with sequence homology to the dsRNA trigger and thereby inhibition of virus replication. We show that although dengue virus type 2 (DENV2 infection of Ae. aegypti cultured cells and oral infection of adult mosquitoes generated dsRNA and production of DENV2-specific siRNAs, virus replication and release of infectious virus persisted, suggesting viral circumvention of RNAi. We also show that DENV2 does not completely evade RNAi, since impairing the pathway by silencing expression of dcr2, r2d2, or ago2, genes encoding important sensor and effector proteins in the RNAi pathway, increased virus replication in the vector and decreased the extrinsic incubation period required for virus transmission. Our findings indicate a major role for RNAi as a determinant of DENV transmission by Ae. aegypti.

  2. Steric restrictions of RISC in RNA interference identified with size-expanded RNA nucleobases.

    Science.gov (United States)

    Hernández, Armando R; Peterson, Larryn W; Kool, Eric T

    2012-08-17

    Understanding the interactions between small interfering RNAs (siRNAs) and the RNA-induced silencing complex (RISC), the key protein complex of RNA interference (RNAi), is of great importance to the development of siRNAs with improved biological and potentially therapeutic function. Although various chemically modified siRNAs have been reported, relatively few studies with modified nucleobases exist. Here we describe the synthesis and hybridization properties of siRNAs bearing size-expanded RNA (xRNA) nucleobases and their use as a novel and systematic set of steric probes in RNAi. xRNA nucleobases are expanded by 2.4 Å using benzo-homologation and retain canonical Watson-Crick base-pairing groups. Our data show that the modified siRNA duplexes display small changes in melting temperature (+1.4 to -5.0 °C); substitutions near the center are somewhat destabilizing to the RNA duplex, while substitutions near the ends are stabilizing. RNAi studies in a dual-reporter luciferase assay in HeLa cells revealed that xRNA nucleobases in the antisense strand reduce activity at some central positions near the seed region but are generally well tolerated near the ends. Most importantly, we observed that xRNA substitutions near the 3'-end increased activity over that of wild-type siRNAs. The data are analyzed in terms of site-dependent steric effects in RISC. Circular dichroism experiments show that single xRNA substitutions do not significantly distort the native A-form helical structure of the siRNA duplex, and serum stability studies demonstrated that xRNA substitutions protect siRNAs against nuclease degradation.

  3. Emerging strategies for RNA interference (RNAi) applications in insects.

    Science.gov (United States)

    Nandety, Raja Sekhar; Kuo, Yen-Wen; Nouri, Shahideh; Falk, Bryce W

    2015-01-01

    RNA interference (RNAi) in insects is a gene regulatory process that also plays a vital role in the maintenance and in the regulation of host defenses against invading viruses. Small RNAs determine the specificity of the RNAi through precise recognition of their targets. These small RNAs in insects comprise small interfering RNAs (siRNAs), micro RNAs (miRNAs) and Piwi interacting RNAs (piRNAs) of various lengths. In this review, we have explored different forms of the RNAi inducers that are presently in use, and their applications for an effective and efficient fundamental and practical RNAi research with insects. Further, we reviewed trends in next generation sequencing (NGS) technologies and their importance for insect RNAi, including the identification of novel insect targets as well as insect viruses. Here we also describe a rapidly emerging trend of using plant viruses to deliver the RNAi inducer molecules into insects for an efficient RNAi response.

  4. RNA Interference in Insect Vectors for Plant Viruses

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    Surapathrudu Kanakala

    2016-12-01

    Full Text Available Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists.

  5. Tumor-specific RNA interference targeting Pokemon suppresses tumor growth and induces apoptosis in prostate cancer.

    Science.gov (United States)

    Li, Yining; Xu, Shuxiong; Wang, Xiangwei; Shi, Hua; Sun, Zhaolin; Yang, Zhao

    2013-02-01

    To explore the exact mechanism of Pokemon in prostate cancer. Pokemon is a member of the POK family of transcriptional repressors. Its main function is suppression of the p14ARF (alternate reading frame) tumor suppressor gene. Although Pokemon expression has been found to be increased in various types of lymphoma, the exact mechanism of the gene in prostate cancer is not clear. In the present study, prostate cancer cells were transfected with the specific short hairpin ribonucleic acid (RNA) expression vector targeting Pokemon. The expression of Pokemon messenger RNA and its protein was detected by semiquantitative reverse transcriptase-polymerase chain reaction and Western blotting, respectively. The cell growth and cell apoptosis were also examined using the methyl thiazolyl tetrazolium assay and flow cytometry. The results demonstrated that specific RNA interference (RNAi) could decrease the expression levels of Pokemon gene messenger RNA and protein in prostate cancer cells. In addition, that specific RNAi significantly inhibited the cell proliferation and increased the apoptotic rate. In vivo experiments showed that specific RNAi inhibited the tumorigenicity of prostate cancer cells and significantly suppressed tumor growth. Therefore, an RNAi-targeted Pokemon gene strategy could be a potential approach to prostate cancer therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. A simple and robust vector-based shRNA expression system used for RNA interference.

    Science.gov (United States)

    Wang, Xue-jun; Li, Ying; Huang, Hai; Zhang, Xiu-juan; Xie, Pei-wen; Hu, Wei; Li, Dan-dan; Wang, Sheng-qi

    2013-01-01

    RNA interference (RNAi) mediated by small interfering RNAs (siRNAs) or short hairpin RNAs (shRNAs) has become a powerful genetic tool for conducting functional studies. Previously, vector-based shRNA-expression strategies capable of inducing RNAi in viable cells have been developed, however, these vector systems have some disadvantages, either because they were error-prone or cost prohibitive. In this report we described the development of a simple, robust shRNA expression system utilizing 1 long oligonucleotide or 2 short oligonucleotides for half the cost of conventional shRNA construction methods and with a >95% cloning success rate. The shRNA loop sequence and stem structure were also compared and carefully selected for better RNAi efficiency. Furthermore, an easier strategy was developed based on isocaudomers which permit rapid combination of the most efficient promoter-shRNA cassettes. Finally, using this method, the conservative target sites for hepatitis B virus (HBV) knockdown were systemically screened and HBV antigen expression shown to be successfully suppressed in the presence of connected multiple shRNAs both in vitro and in vivo. This novel design describes an inexpensive and effective way to clone and express single or multiple shRNAs from the same vector with the capacity for potent and effective silencing of target genes.

  7. A simple and robust vector-based shRNA expression system used for RNA interference.

    Directory of Open Access Journals (Sweden)

    Xue-jun Wang

    Full Text Available BACKGROUND: RNA interference (RNAi mediated by small interfering RNAs (siRNAs or short hairpin RNAs (shRNAs has become a powerful genetic tool for conducting functional studies. Previously, vector-based shRNA-expression strategies capable of inducing RNAi in viable cells have been developed, however, these vector systems have some disadvantages, either because they were error-prone or cost prohibitive. RESULTS: In this report we described the development of a simple, robust shRNA expression system utilizing 1 long oligonucleotide or 2 short oligonucleotides for half the cost of conventional shRNA construction methods and with a >95% cloning success rate. The shRNA loop sequence and stem structure were also compared and carefully selected for better RNAi efficiency. Furthermore, an easier strategy was developed based on isocaudomers which permit rapid combination of the most efficient promoter-shRNA cassettes. Finally, using this method, the conservative target sites for hepatitis B virus (HBV knockdown were systemically screened and HBV antigen expression shown to be successfully suppressed in the presence of connected multiple shRNAs both in vitro and in vivo. CONCLUSION: This novel design describes an inexpensive and effective way to clone and express single or multiple shRNAs from the same vector with the capacity for potent and effective silencing of target genes.

  8. RNA virus interference via CRISPR/Cas13a system in plants

    KAUST Repository

    Aman, Rashid; Ali, Zahir; Butt, Haroon; Mahas, Ahmed; Aljedaani, Fatimah R.; Khan, Muhammad Zuhaib; Ding, Shouwei; Mahfouz, Magdy M.

    2018-01-01

    -crRNAs into functional crRNAs.Our data indicate that CRISPR/Cas13a can be used for engineering interference against RNA viruses, providing a potential novel mechanism for RNA-guided immunity against RNA viruses and for other RNA manipulations in plants.

  9. Perceptual load-dependent neural correlates of distractor interference inhibition.

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    Jiansong Xu

    2011-01-01

    Full Text Available The load theory of selective attention hypothesizes that distractor interference is suppressed after perceptual processing (i.e., in the later stage of central processing at low perceptual load of the central task, but in the early stage of perceptual processing at high perceptual load. Consistently, studies on the neural correlates of attention have found a smaller distractor-related activation in the sensory cortex at high relative to low perceptual load. However, it is not clear whether the distractor-related activation in brain regions linked to later stages of central processing (e.g., in the frontostriatal circuits is also smaller at high rather than low perceptual load, as might be predicted based on the load theory.We studied 24 healthy participants using functional magnetic resonance imaging (fMRI during a visual target identification task with two perceptual loads (low vs. high. Participants showed distractor-related increases in activation in the midbrain, striatum, occipital and medial and lateral prefrontal cortices at low load, but distractor-related decreases in activation in the midbrain ventral tegmental area and substantia nigra (VTA/SN, striatum, thalamus, and extensive sensory cortices at high load.Multiple levels of central processing involving midbrain and frontostriatal circuits participate in suppressing distractor interference at either low or high perceptual load. For suppressing distractor interference, the processing of sensory inputs in both early and late stages of central processing are enhanced at low load but inhibited at high load.

  10. Perceptual load-dependent neural correlates of distractor interference inhibition.

    Science.gov (United States)

    Xu, Jiansong; Monterosso, John; Kober, Hedy; Balodis, Iris M; Potenza, Marc N

    2011-01-18

    The load theory of selective attention hypothesizes that distractor interference is suppressed after perceptual processing (i.e., in the later stage of central processing) at low perceptual load of the central task, but in the early stage of perceptual processing at high perceptual load. Consistently, studies on the neural correlates of attention have found a smaller distractor-related activation in the sensory cortex at high relative to low perceptual load. However, it is not clear whether the distractor-related activation in brain regions linked to later stages of central processing (e.g., in the frontostriatal circuits) is also smaller at high rather than low perceptual load, as might be predicted based on the load theory. We studied 24 healthy participants using functional magnetic resonance imaging (fMRI) during a visual target identification task with two perceptual loads (low vs. high). Participants showed distractor-related increases in activation in the midbrain, striatum, occipital and medial and lateral prefrontal cortices at low load, but distractor-related decreases in activation in the midbrain ventral tegmental area and substantia nigra (VTA/SN), striatum, thalamus, and extensive sensory cortices at high load. Multiple levels of central processing involving midbrain and frontostriatal circuits participate in suppressing distractor interference at either low or high perceptual load. For suppressing distractor interference, the processing of sensory inputs in both early and late stages of central processing are enhanced at low load but inhibited at high load.

  11. Prefrontal inhibition of threat processing protects working memory from interference.

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    Robert James Clarke

    2013-05-01

    Full Text Available Bottom-up processes can interrupt ongoing cognitive processing in order to adaptively respond to emotional stimuli of high potential significance, such as those that threaten wellbeing. However it is vital that this interference can be modulated in certain contexts to focus on current tasks. Deficits in the ability to maintain the appropriate balance between cognitive and emotional demands can severely impact on day-to-day activities. This fMRI study examined this interaction between threat processing and cognition; 18 adult participants performed a visuospatial working memory (WM task with two load conditions, in the presence and absence of anxiety induction by threat of electric shock. Threat of shock interfered with performance in the low cognitive load condition; however interference was eradicated under high load, consistent with engagement of emotion regulation mechanisms. Under low load the amygdala showed significant activation to threat of shock that was modulated by high cognitive load. A directed top-down control contrast identified two regions associated with top-down control; ventrolateral PFC and dorsal ACC. Dynamic causal modelling provided further evidence that under high cognitive load, top-down inhibition is exerted on the amygdala and its outputs to prefrontal regions. Additionally, we hypothesised that individual differences in a separate, non-emotional top-down control task would predict the recruitment of dorsal ACC and ventrolateral PFC during top-down control of threat. Consistent with this, performance on a separate dichotic listening task predicted dorsal ACC and ventrolateral PFC activation during high WM load under threat of shock, though activation in these regions did not directly correlate with WM performance. Together, the findings suggest that under high cognitive load and threat, top-down control is exerted by dACC and vlPFC to inhibit threat processing, thus enabling WM performance without threat

  12. RNA interference-based resistance against a legume mastrevirus

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    Mansoor Shahid

    2011-11-01

    Full Text Available Abstract Background RNA interference (RNAi is a homology-dependant gene silencing mechanism and has been widely used to engineer resistance in plants against RNA viruses. However, its usefulness in delivering resistance against plant DNA viruses belonging to family Geminiviridae is still being debated. Although the RNAi approach has been shown, using a transient assay, to be useful in countering monocotyledonous plant-infecting geminiviruses of the genus Mastrevirus, it has yet to be investigated as a means of delivering resistance to dicot-infecting mastreviruses. Chickpea chlorotic dwarf Pakistan virus (CpCDPKV is a legume-infecting mastrevirus that affects chickpea and other leguminous crops in Pakistan. Results Here a hairpin (hpRNAi construct containing sequences encompassing part of replication-associated protein gene, intergenic region and part of the movement protein gene of CpCDPKV under the control of the Cauliflower mosaic virus 35S promoter has been produced and stably transformed into Nicotiana benthamiana. Plants harboring the hairpin construct were challenged with CpCDPKV. All non-transgenic N. benthamiana plants developed symptoms of CpCDPKV infection within two weeks post-inoculation. In contrast, none of the inoculated transgenic plants showed symptoms of infection and no viral DNA could be detected by Southern hybridization. A real-time quantitative PCR analysis identified very low-level accumulation of viral DNA in the inoculated transgenic plants. Conclusions The results presented show that the RNAi-based resistance strategy is useful in protecting plants from a dicot-infecting mastrevirus. The very low levels of virus detected in plant tissue of transgenic plants distal to the inoculation site suggest that virus movement and/or viral replication was impaired leading to plants that showed no discernible signs of virus infection.

  13. Retention and loss of RNA interference pathways in trypanosomatid protozoans.

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    Lon-Fye Lye

    2010-10-01

    Full Text Available RNA interference (RNAi pathways are widespread in metaozoans but the genes required show variable occurrence or activity in eukaryotic microbes, including many pathogens. While some Leishmania lack RNAi activity and Argonaute or Dicer genes, we show that Leishmania braziliensis and other species within the Leishmania subgenus Viannia elaborate active RNAi machinery. Strong attenuation of expression from a variety of reporter and endogenous genes was seen. As expected, RNAi knockdowns of the sole Argonaute gene implicated this protein in RNAi. The potential for functional genetics was established by testing RNAi knockdown lines lacking the paraflagellar rod, a key component of the parasite flagellum. This sets the stage for the systematic manipulation of gene expression through RNAi in these predominantly diploid asexual organisms, and may also allow selective RNAi-based chemotherapy. Functional evolutionary surveys of RNAi genes established that RNAi activity was lost after the separation of the Leishmania subgenus Viannia from the remaining Leishmania species, a divergence associated with profound changes in the parasite infectious cycle and virulence. The genus Leishmania therefore offers an accessible system for testing hypothesis about forces that may select for the loss of RNAi during evolution, such as invasion by viruses, changes in genome plasticity mediated by transposable elements and gene amplification (including those mediating drug resistance, and/or alterations in parasite virulence.

  14. Downregulation of survivin by siRNA inhibits invasion and promotes apoptosis in neuroblastoma SH-SY5Y cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Liang, H. [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan (China); Cao, W. [Department of Obstetrics, Qingdao Central Hospital, Qingdao (China); Xu, R.; Ju, X.L. [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan (China)

    2014-05-23

    Neuroblastoma is a solid tumor that occurs mainly in children. Malignant neuroblastomas have a poor prognosis because conventional chemotherapeutic agents are not very effective. Survivin, a member of the inhibitor of the apoptosis protein family, plays a significant role in cell division, inhibition of apoptosis, and promotion of cell proliferation and invasion. Previous studies found that survivin is highly expressed in some malignant neuroblastomas and is correlated with poor prognosis. The aim of this study was to investigate whether survivin could serve as a potential therapeutic target of human neuroblastoma. We employed RNA interference to reduce survivin expression in the human neuroblastoma SH-SY5Y cell line and analyzed the effect of RNA interference on cell proliferation and invasion in vitro and in vivo. RNA interference of survivin led to a significant decrease in invasiveness and proliferation and increased apoptosis in SH-SY5Y cells in vitro. RNA interference of survivin inhibited tumor growth in vivo by 68±13% (P=0.002) and increased the number of apoptotic cells by 9.8±1.2% (P=0.001) compared with negative small interfering RNA (siRNA) treatment controls. Moreover, RNA interference of survivin inhibited the formation of lung metastases by 92% (P=0.002) and reduced microvascular density by 60% (P=0.0003). Survivin siRNA resulted in significant downregulation of survivin mRNA and protein expression both in vitro and in vivo compared with negative siRNA treatment controls. RNA interference of survivin was found to be a potent inhibitor of SH-SY5Y tumor growth and metastasis formation. These results support further clinical development of RNA interference of survivin as a treatment of neuroblastoma and other cancer types.

  15. RNA Interference in the Age of CRISPR: Will CRISPR Interfere with RNAi?

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    Unnikrishnan Unniyampurath

    2016-02-01

    Full Text Available The recent emergence of multiple technologies for modifying gene structure has revolutionized mammalian biomedical research and enhanced the promises of gene therapy. Over the past decade, RNA interference (RNAi based technologies widely dominated various research applications involving experimental modulation of gene expression at the post-transcriptional level. Recently, a new gene editing technology, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR and the CRISPR-associated protein 9 (Cas9 (CRISPR/Cas9 system, has received unprecedented acceptance in the scientific community for a variety of genetic applications. Unlike RNAi, the CRISPR/Cas9 system is bestowed with the ability to introduce heritable precision insertions and deletions in the eukaryotic genome. The combination of popularity and superior capabilities of CRISPR/Cas9 system raises the possibility that this technology may occupy the roles currently served by RNAi and may even make RNAi obsolete. We performed a comparative analysis of the technical aspects and applications of the CRISPR/Cas9 system and RNAi in mammalian systems, with the purpose of charting out a predictive picture on whether the CRISPR/Cas9 system will eclipse the existence and future of RNAi. The conclusion drawn from this analysis is that RNAi will still occupy specific domains of biomedical research and clinical applications, under the current state of development of these technologies. However, further improvements in CRISPR/Cas9 based technology may ultimately enable it to dominate RNAi in the long term.

  16. Immunoregulation by interference RNA (iRNA – mechanisms, role, perspective

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    Emilia Sikora

    2011-08-01

    Full Text Available The functioning of an organism depends on the precise control mechanisms, constantly adjusted to the actual state. Therefore, there is a need for efficient communication between both adjacent and distant cells, which may be executed by proteins such as hormones, neurotransmitters and cytokines. Recently another means of regulation has emerged – short regulatory RNAs (srRNAs. Although discovered only a couple of years ago, the mechanism of RNA interference has already become a topic of thousands of publications, defining its roles in both physiological and pathological processes, such as cancerogenesis and autoimmunization.RNAs regulating cell function may be coded in its genome (both exons and introns or be introduced from the external environment. In mammals microRNAs (miRNAs cooperate with proteins from the Ago/PIWI family to form effector ribonucleoprotein complexes, and owing to their complementarity to the target mRNA, control genes’ expression at the posttranscriptional level, either through the suppression of mRNA translation or through mRNA degradation.SrRNAs are crucial regulators throughout the development of immune cells, starting from hematopoietic stem cells, up to the effector cells of the adaptive immune response. Moreover, some of the regulatory cells perform their function by releasing miRNAs, which are then transported to the target cells, possibly enclosed in the exosomes.

  17. Radiation enhancement effect of RNA interference for HIF-1α on the transplant tumor

    International Nuclear Information System (INIS)

    Ren Ruimei; Sun Xindong; Zhao Hanxi; Yan Qingxia; Huang Guangwu

    2008-01-01

    Objective: To determine and explore the radiation enhancement of RNA interference for HIF-1α on the transplant tumor using polycationic polyethylenimine (PEI), as a new kind of gene vector. Methods: SPCA-1 nude mouse model was used. 160 nude mice bearing SPCA-1 were randomly divided into 4 treated groups and 1 control groups, each group had 32 mice. The expression of HIF-1α was studied by immunohistochemical method after RNA interference for HIF-1α. The differences of the volume, weight, survival time of the transplant tumor were studied among the simple radiation group, the simple RNA interference for HIF- 1α group and the combination of radiation and RNA interference for HIF-1α. Results: The expression of HIF-1α was decreased after RNA interference for HIF-1α. RNA interference for HIF-1α combined with radiation decreased the volume, weight of the transplant tumor, and prolonged its survival time period significantly than other methods. Conclusions: RNA interference targeting HIF-1α might enhance the radiosensitivity of the transplant tumor using PEI as a new kind of gene vector in vitro. (authors)

  18. siRNA-mediated RNA interference in precision-cut tissue slices prepared from mouse lung and kidney

    NARCIS (Netherlands)

    Ruigrok, Mitchel J. R.; Maggan, Nalinie; Willaert, Delphine; Frijlink, Henderik W.; Melgert, Barbro N.; Olinga, Peter; Hinrichs, Wouter L. J.

    Small interfering RNA (siRNA)-mediated RNAi interference (RNAi) is a powerful post-transcriptional gene silencing mechanism which can be used to study the function of genes in vitro (cell cultures) and in vivo (animal models). However, there is a translational gap between these models. Hence, there

  19. CRISPR/Cas13 as a Tool for RNA Interference

    KAUST Repository

    Ali, Zahir; Mahas, Ahmed; Mahfouz, Magdy M.

    2018-01-01

    Almost all biological processes involve RNA, making it crucial to develop tools for manipulation of the transcriptome. The bacterial CRISPR/Cas13 system was recently rewired to facilitate RNA manipulation in eukaryotes, including plants. We discuss

  20. CRISPR/Cas13 as a Tool for RNA Interference

    KAUST Repository

    Ali, Zahir

    2018-03-28

    Almost all biological processes involve RNA, making it crucial to develop tools for manipulation of the transcriptome. The bacterial CRISPR/Cas13 system was recently rewired to facilitate RNA manipulation in eukaryotes, including plants. We discuss here the opportunities and limitations of using CRISPR/Cas13 in plants for various types of RNA manipulation.

  1. Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection.

    Directory of Open Access Journals (Sweden)

    Zach N Adelman

    Full Text Available The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus, exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery.We utilized transgenic "sensor" strains of Aedes aegypti to examine the role of temperature on RNA silencing. These "sensor" strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2 or Argonaute-2 (AGO-2. We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18°C as compared with 28°C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA trigger for RNAi, showed no change in EGFP expression when reared at 18°C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses.This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting the antiviral immunity of disease vectors.

  2. [Expression of Jagged1 mRNA in human epithelial ovarian carcinoma tissues and effect of RNA interference of Jagged1 on growth of xenograft in nude mice].

    Science.gov (United States)

    Liu, G Y; Gao, Z H; Li, L; Song, T T; Sheng, X G

    2016-06-25

    To investigate the expression of Jagged1 in human epithelial ovarian carcinoma tissues and the effect of Jagged1 on growth of xenograft in nude mice. (1) Forty-eight cases of ovarian cancer and 30 cases of patients with benign epithelial ovarian tumor in the Henan Province Xinxiang Central Hospital during Feb. 2011 to Mar. 2014 were enrolled in this study. The mRNA expression of Jagged1, Notch1 and the downstream target genes Hes1, Hey1 were analyzed by using realtime PCR method. (2) The ovarian cancer xenograft models in nude mice were constructed by injecting SKOV3 cells in axillary subcutaneouswere. The nude mice were randomly divided into Jagged1 interference group, blank plasmid group and control group. Each group had 10 mice. They were transfected with pcDNA3.1(+)-siRNA-Jagged1, blank plasmid pDC3.1 and phosphate buffer, respectively. The tumor volumes and tumor masses were measured 14 days after transfection and the inhibition rate was calculated. The relative mRNA expression of Jagged1, Notch1, Hes1 and Hey1 in xenograft tissues after transfection in each group was detected by using realtime PCR technique and the relative protein expression of Jagged1, Notch1, Hes1 and Hey1 in xenograft tissues was detected by utilizing western blot method. (1) The relative mRNA expression of Jagged1, Notch1, Hes1 and Hey1 in ovarian cancer tissues were higher than benign ovarian tumor tissues, the differences were statistically significant (Ptissues of nude micein Jagged1 interference group were lower than that in the other two groups, the differences were statistically significant (Ptissues of nude mice among the three groups (P>0.05). Jagged1 is highly expressed in epithelial ovarian carcinoma. Jagged1 gene interference in xenograft tumor can inhibit ovarian cancer cell growth and improve tumor suppressor rate, which probably play roles by inhibiting Notch1 signaling pathway.

  3. A viral suppressor of RNA silencing inhibits ARGONAUTE 1 function by precluding target RNA binding to pre-assembled RISC.

    Science.gov (United States)

    Kenesi, Erzsébet; Carbonell, Alberto; Lózsa, Rita; Vértessy, Beáta; Lakatos, Lóránt

    2017-07-27

    In most eukaryotes, RNA silencing is an adaptive immune system regulating key biological processes including antiviral defense. To evade this response, viruses of plants, worms and insects have evolved viral suppressors of RNA silencing proteins (VSRs). Various VSRs, such as P1 from Sweet potato mild mottle virus (SPMMV), inhibit the activity of RNA-induced silencing complexes (RISCs) including an ARGONAUTE (AGO) protein loaded with a small RNA. However, the specific mechanisms explaining this class of inhibition are unknown. Here, we show that SPMMV P1 interacts with AGO1 and AGO2 from Arabidopsis thaliana, but solely interferes with AGO1 function. Moreover, a mutational analysis of a newly identified zinc finger domain in P1 revealed that this domain could represent an effector domain as it is required for P1 suppressor activity but not for AGO1 binding. Finally, a comparative analysis of the target RNA binding capacity of AGO1 in the presence of wild-type or suppressor-defective P1 forms revealed that P1 blocks target RNA binding to AGO1. Our results describe the negative regulation of RISC, the small RNA containing molecular machine. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Characterization of RNA interference in rat PC12 cells

    DEFF Research Database (Denmark)

    Thonberg, Håkan; Schéele, Camilla C; Dahlgren, Cecilia

    2004-01-01

    strand of the siRNA guides a multi-protein complex, RNA-induced silencing complex (RISC), to cleave target mRNA. Although the exact function and composition of RISC is still unclear, it has been shown to include several proteins of the Argonaute protein family. Here we report of a robust system...... of the rat Golgi-ER protein 95 kDa (GERp95), an Argonaute family protein, by siRNA methodology. After GERp95-ablation, sequential knockdown of NPY by siRNA was shown to be impaired. Thus, we report that the GERp95 protein is functionally required for RNAi targeting NPY in rat PC12 cells....

  5. RNA virus interference via CRISPR/Cas13a system in plants

    KAUST Repository

    Aman, Rashid

    2018-01-04

    CRISPR/Cas systems confer immunity against invading nucleic acids and phages in bacteria and archaea. CRISPR/Cas13a (known previously as C2c2) is a class 2 type VI-A ribonuclease capable of targeting and cleaving single-stranded RNA (ssRNA) molecules of the phage genome. Here, we employ CRISPR/Cas13a to engineer interference with an RNA virus, Turnip Mosaic Virus (TuMV), in plants.CRISPR/Cas13a produces interference against green fluorescent protein (GFP)-expressing TuMV in transient assays and stable overexpression lines of Nicotiana benthamiana. CRISPR RNA (crRNAs) targeting the HC-Pro and GFP sequences exhibit better interference than those targeting other regions such as coat protein (CP) sequence. Cas13a can also process pre-crRNAs into functional crRNAs.Our data indicate that CRISPR/Cas13a can be used for engineering interference against RNA viruses, providing a potential novel mechanism for RNA-guided immunity against RNA viruses and for other RNA manipulations in plants.

  6. Inhibition of poliovirus RNA synthesis by brefeldin A.

    OpenAIRE

    Maynell, L A; Kirkegaard, K; Klymkowsky, M W

    1992-01-01

    Brefeldin A (BFA), a fungal metabolite that blocks transport of newly synthesized proteins from the endoplasmic reticulum, was found to inhibit poliovirus replication 10(5)- to 10(6)-fold. BFA does not inhibit entry of poliovirus into the cell or translation of viral RNA. Poliovirus RNA synthesis, however, is completely inhibited by BFA. A specific class of membranous vesicles, with which the poliovirus replication complex is physically associated, is known to proliferate in poliovirus-infect...

  7. Application of RNA interference in treating human diseases

    Indian Academy of Sciences (India)

    ference than either strand individually. After injection into ... antisense strand to messenger RNAs (mRNAs) that bear ... processing of longer dsRNA and stem loop precursors (Nov- ... RNAi has several applications in biomedical research,.

  8. RNA virus interference via CRISPR/Cas13a system in plants

    KAUST Repository

    Aman, Rashid

    2017-11-04

    CRISPR/Cas systems confer immunity against invading nucleic acids and phages in bacteria and archaea. CRISPR/Cas13a (known previously as C2c2) is a class 2 type VI-A ribonuclease capable of targeting and cleaving single stranded RNA (ssRNA) molecules of the phage genome. Here, we employ CRISPR/Cas13a to engineer interference with an RNA virus, Turnip Mosaic Virus (TuMV), in plants. CRISPR/Cas13a produced interference against green fluorescent protein (GFP) expressing TuMV in transient assays and stable overexpression lines of Nicotiana benthamiana. crRNAs targeting the HC-Pro and GFP sequences exhibited better interference than those targeting other regions such as coat protein (CP) sequence. Cas13a can also process pre-crRNAs into functional crRNAs. Our data indicate that CRISPR/Cas13a can be used for engineering interference against RNA viruses, providing a potential novel mechanism for RNA-guided immunity against RNA viruses, and for other RNA manipulations in plants.

  9. RNA interference targeting cytosolic NADP(+)-dependent isocitrate dehydrogenase exerts anti-obesity effect in vitro and in vivo.

    Science.gov (United States)

    Nam, Woo Suk; Park, Kwon Moo; Park, Jeen-Woo

    2012-08-01

    A metabolic abnormality in lipid biosynthesis is frequently associated with obesity and hyperlipidemia. Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) is an essential reducing equivalent for numerous enzymes required in fat and cholesterol biosynthesis. Cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) has been proposed as a key enzyme for supplying cytosolic NADPH. We report here that knockdown of IDPc expression by Ribonucleic acid (RNA) interference (RNAi) inhibited adipocyte differentiation and lipogenesis in 3T3-L1 preadipocytes and mice. Attenuated IDPc expression by IDPc small interfering RNA (siRNA) resulted in a reduction of differentiation and triglyceride level and adipogenic protein expression as well as suppression of glucose uptake in cultured adipocytes. In addition, the attenuation of Nox activity and Reactive oxygen species (ROS) generation accompanied with knockdown of IDPc was associated with inhibition of adipogenesis and lipogenesis. The loss of body weight and the reduction of triglyceride level were also observed in diet-induced obese mice transduced with IDPc short-hairpin (shRNA). Taken together, the inhibiting effect of RNAi targeting IDPc on adipogenesis and lipid biosynthesis is considered to be of therapeutic value in the treatment and prevention of obesity and obesity-associated metabolic syndrome. © 2012 Elsevier B.V. All rights reserved.

  10. Application of RNA interference methodology to investigate and ...

    Indian Academy of Sciences (India)

    Specific fragments of the sugarcane mosaic virus (SCMV) coat protein gene (cp) were amplified by reverse transcription-polymerase chain reaction and used to construct a marker free small interfering RNA complex expression vector against SCMV. In planta transformation was performed on maize (Zea mays) inbred line ...

  11. DBR1 siRNA inhibition of HIV-1 replication

    Directory of Open Access Journals (Sweden)

    Naidu Yathi

    2005-10-01

    Full Text Available Abstract Background HIV-1 and all retroviruses are related to retroelements of simpler organisms such as the yeast Ty elements. Recent work has suggested that the yeast retroelement Ty1 replicates via an unexpected RNA lariat intermediate in cDNA synthesis. The putative genomic RNA lariat intermediate is formed by a 2'-5' phosphodiester bond, like that found in pre-mRNA intron lariats and it facilitates the minus-strand template switch during cDNA synthesis. We hypothesized that HIV-1 might also form a genomic RNA lariat and therefore that siRNA-mediated inhibition of expression of the human RNA lariat de-branching enzyme (DBR1 expression would specifically inhibit HIV-1 replication. Results We designed three short interfering RNA (siRNA molecules targeting DBR1, which were capable of reducing DBR1 mRNA expression by 80% and did not significantly affect cell viability. We assessed HIV-1 replication in the presence of DBR1 siRNA and found that DBR1 knockdown led to decreases in viral cDNA and protein production. These effects could be reversed by cotransfection of a DBR1 cDNA indicating that the inhibition of HIV-1 replication was a specific effect of DBR1 underexpression. Conclusion These data suggest that DBR1 function may be needed to debranch a putative HIV-1 genomic RNA lariat prior to completion of reverse transcription.

  12. Transduction of hematopoietic stem cells to stimulate RNA interference against feline infectious peritonitis.

    Science.gov (United States)

    Anis, Eman A; Dhar, Madhu; Legendre, Alfred M; Wilkes, Rebecca P

    2017-06-01

    Objectives The goals of the study were: (1) to develop and evaluate non-replicating lentivirus vectors coding for feline coronavirus (FCoV)-specific micro (mi)RNA as a potential antiviral therapy for feline infectious peritonitis (FIP); (2) to assess the feasibility of transducing hematopoietic stem cells (HSCs) with ex vivo introduction of the miRNA-expressing lentivirus vector; and (3) to assess the ability of the expressed miRNA to inhibit FCoV replication in HSCs in vitro. Methods HSCs were obtained from feline bone marrow and replicated in vitro. Three lentiviruses were constructed, each expressing a different anti-FCoV miRNA. HSCs were stably transduced with the miRNA-expressing lentivirus vector that produced the most effective viral inhibition in a feline cell line. The effectiveness of the transduction and the expression of anti-FCoV miRNA were tested by infecting the HSCs with two different strains of FCoV. The inhibition of coronavirus replication was determined by relative quantification of the inhibition of intracellular viral genomic RNA synthesis using real-time, reverse-transcription PCR. The assessment of virus replication inhibition was determined via titration of extracellular virus using the TCID 50 assay. Results Inhibition of FCoV was most significant in feline cells expressing miRNA-L2 that targeted the viral leader sequence, 48 h postinfection. miRNA-L2 expression in stably transduced HSCs resulted in 90% and 92% reductions in FIPV WSU 79-1146 genomic RNA synthesis and extracellular virus production, respectively, as well as 74% and 80% reduction in FECV WSU 79-1683 genomic RNA synthesis and extracellular virus production, respectively, as compared with an infected negative control sample producing non-targeting miRNA. Conclusions and relevance These preliminary results show that genetic modification of HSCs for constitutive production of anti-coronavirus miRNA will reduce FCoV replication.

  13. RNA interference screen identifies Abl kinase and PDGFR signaling in Chlamydia trachomatis entry.

    Directory of Open Access Journals (Sweden)

    Cherilyn A Elwell

    2008-03-01

    Full Text Available The strain designated Chlamydia trachomatis serovar L2 that was used for experiments in this paper is Chlamydia muridarum, a species closely related to C. trachomatis (and formerly termed the Mouse Pneumonitis strain of C. trachomatis. This conclusion was verified by deep sequencing and by PCR using species-specific primers. All data presented in the results section that refer to C. trachomatis should be interpreted as referring to C. muridarum. Since C. muridarum TARP lacks the consensus tyrosine repeats present in C. trachomatis TARP, we cannot make any conclusions about the role of TARP phosphorylation and C. muridarum entry. However, the conclusion that C. trachomatis L2 TARP is a target of Abl kinase is still valid as these experiments were performed with C. trachomatis L2 TARP [corrected]. To elucidate the mechanisms involved in early events in Chlamydia trachomatis infection, we conducted a large scale unbiased RNA interference screen in Drosophila melanogaster S2 cells. This allowed identification of candidate host factors in a simple non-redundant, genetically tractable system. From a library of 7,216 double stranded RNAs (dsRNA, we identified approximately 226 host genes, including two tyrosine kinases, Abelson (Abl kinase and PDGF- and VEGF-receptor related (Pvr, a homolog of the Platelet-derived growth factor receptor (PDGFR. We further examined the role of these two kinases in C. trachomatis binding and internalization into mammalian cells. Both kinases are phosphorylated upon infection and recruited to the site of bacterial attachment, but their roles in the infectious process are distinct. We provide evidence that PDGFRbeta may function as a receptor, as inhibition of PDGFRbeta by RNA interference or by PDGFRbeta neutralizing antibodies significantly reduces bacterial binding, whereas depletion of Abl kinase has no effect on binding. Bacterial internalization can occur through activation of PDGFRbeta or through independent

  14. Application of RNA interference methodology to investigate and ...

    Indian Academy of Sciences (India)

    2014-07-31

    Jul 31, 2014 ... effective and economical method of inhibition gene expres- sion (Zhang et al. 2010 ... A cotransformation system via a two T-DNA vector was used to .... washed immediately with water after inoculation, and the. PBS buffer ..... study design, data collection and analysis, decision to publish, or preparation of ...

  15. An archaeal CRISPR type III-B system exhibiting distinctive RNA targeting features and mediating dual RNA and DNA interference

    DEFF Research Database (Denmark)

    Peng, Wenfang; Feng, Mingxia; Feng, Xu

    2015-01-01

    CRISPR-Cas systems provide a small RNA-based mechanism to defend against invasive genetic elements in archaea and bacteria. To investigate the in vivo mechanism of RNA interference by two type III-B systems (Cmr-α and Cmr-β) in Sulfolobus islandicus, a genetic assay was developed using plasmids...... carrying an artificial mini-CRISPR (AC) locus with a single spacer. After pAC plasmids were introduced into different strains, Northern analyses confirmed that mature crRNAs were produced from the plasmid-borne CRISPR loci, which then guided gene silencing to target gene expression. Spacer mutagenesis....... islandicus Cmr-α mediated transcription-dependent DNA interference, the Cmr-α constitutes the first CRISPR system exhibiting dual targeting of RNA and DNA....

  16. Accumulation of dsRNA in endosomes contributes to inefficient RNA interference in the fall armyworm, Spodoptera frugiperda.

    Science.gov (United States)

    Yoon, June-Sun; Gurusamy, Dhandapani; Palli, Subba Reddy

    2017-11-01

    RNA interference (RNAi) efficiency varies among insects studied. The barriers for successful RNAi include the presence of double-stranded ribonucleases (dsRNase) in the lumen and hemolymph that could potentially digest double-stranded RNA (dsRNA) and the variability in the transport of dsRNA into and within the cells. We recently showed that the dsRNAs are transported into lepidopteran cells, but they are not processed into small interference RNAs (siRNAs) because they are trapped in acidic bodies. In the current study, we focused on the identification of acidic bodies in which dsRNAs accumulate in Sf9 cells. Time-lapse imaging studies showed that dsRNAs enter Sf9 cells and accumulate in acidic bodies within 20 min after their addition to the medium. CypHer-5E-labeled dsRNA also accumulated in the midgut and fat body dissected from Spodoptera frugiperda larvae with similar patterns observed in Sf9 cells. Pharmacological inhibitor assays showed that the dsRNAs use clathrin mediated endocytosis pathway for transport into the cells. We investigated the potential dsRNA accumulation sites employing LysoTracker and double labeling experiments using the constructs to express a fusion of green fluorescence protein with early or late endosomal marker proteins and CypHer-5E-labeled dsRNA. Interestingly, CypHer-5E-labeled dsRNA accumulated predominantly in early and late endosomes. These data suggest that entrapment of internalized dsRNA in endosomes is one of the major factors contributing to inefficient RNAi response in lepidopteran insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Transcriptome dynamics of the microRNA inhibition response

    DEFF Research Database (Denmark)

    Wen, Jiayu; Leucci, Elenora; Vendramin, Roberto

    2015-01-01

    We report a high-resolution time series study of transcriptome dynamics following antimiR-mediated inhibition of miR-9 in a Hodgkin lymphoma cell-line-the first such dynamic study of the microRNA inhibition response-revealing both general and specific aspects of the physiological response. We show...... validate the key observations with independent time series qPCR and we experimentally validate key predicted miR-9 targets. Methodologically, we developed sensitive functional data analytic predictive methods to analyse the weak response inherent in microRNA inhibition experiments. The methods...... of this study will be applicable to similar high-resolution time series transcriptome analyses and provides the context for more accurate experimental design and interpretation of future microRNA inhibition studies....

  18. Exosomes: Nanoparticulate tools for RNA interference and drug delivery.

    Science.gov (United States)

    Shahabipour, Fahimeh; Barati, Nastaran; Johnston, Thomas P; Derosa, Giuseppe; Maffioli, Pamela; Sahebkar, Amirhossein

    2017-07-01

    Exosomes are naturally occurring extracellular vesicles released by most mammalian cells in all body fluids. Exosomes are known as key mediators in cell-cell communication and facilitate the transfer of genetic and biochemical information between distant cells. Structurally, exosomes are composed of lipids, proteins, and also several types of RNAs which enable these vesicles to serve as important disease biomarkers. Moreover, exosomes have emerged as novel drug and gene delivery tools owing to their multiple advantages over conventional delivery systems. Recently, increasing attention has been focused on exosomes for the delivery of drugs, including therapeutic recombinant proteins, to various target tissues. Exosomes are also promising vehicles for the delivery of microRNAs and small interfering RNAs, which is usually hampered by rapid degradation of these RNAs, as well as inefficient tissue specificity of currently available delivery strategies. This review highlights the most recent accomplishments and trends in the use of exosomes for the delivery of drugs and therapeutic RNA molecules. © 2017 Wiley Periodicals, Inc.

  19. Inhibition of hepatitis B virus (HBV) by LNA-mediated nuclear interference with HBV DNA transcription

    International Nuclear Information System (INIS)

    Sun, Zhen; Xiang, Wenqing; Guo, Yajuan; Chen, Zhi; Liu, Wei; Lu, Daru

    2011-01-01

    Highlights: → LNA-modified oligonucleotides can pass through the plasma membrane of cultured cells even without using transfection machinery. → LNA-modified oligonucleotides passed efficiently across the cell membrane, and lipid-coating facilitated translocation from the cytoplasm to the nucleus. → LNA-oligonucleotide designed to target nuclear HBV DNA efficiently suppresses HBV replication and transcription in cultured hepatic cells. -- Abstract: Silencing target genes with small regulatory RNAs is widely used to investigate gene function and therapeutic drug development. Recently, triplex-based approaches have provided another attractive means to achieve targeted gene regulation and gene manipulation at the molecular and cellular levels. Nuclear entry of oligonucleotides and enhancement of their affinity to the DNA targets are key points of such approaches. In this study, we developed lipid-based transport of a locked-nucleic-acid (LNA)-modified oligonucleotide for hepatitis B virus (HBV) DNA interference in human hepatocytes expressing HBV genomic DNA. In these cells, the LNA-modified oligonucleotides passed efficiently across the cell membrane, and lipid-coating facilitated translocation from the cytoplasm to the nucleus. The oligonucleotide specifically targeting HBV DNA clearly interfered with HBV DNA transcription as shown by a block in pregenomic RNA (pgRNA) production. The HBV DNA-targeted oligonucleotide suppressed HBV DNA replication and HBV protein production more efficiently than small interfering RNAs directed to the pgRNA. These results demonstrate that fusion with lipid can carry LNA-modified oligonucleotides to the nucleus where they regulate gene expression. Interfering with HBV DNA transcription by LNA-modified oligonucleotides has strong potential as a new strategy for HBV inhibition.

  20. Inhibition of hepatitis B virus (HBV) by LNA-mediated nuclear interference with HBV DNA transcription

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhen [The State Key Laboratory of Genetic Engineering and The MOE Key Laboratory of Contemporary Anthropology, School of Life Science, Fudan University, Shanghai 200433 (China); Department of Biochemistry and Molecular Biology, Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Xiang, Wenqing; Guo, Yajuan [Department of Biochemistry and Molecular Biology, Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Chen, Zhi [The State Key Laboratory for Infectious Disease, Institute of Infectious Disease, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003 (China); Liu, Wei, E-mail: liuwei666@zju.edu.cn [Department of Biochemistry and Molecular Biology, Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Lu, Daru, E-mail: drlu@fudan.edu.cn [The State Key Laboratory of Genetic Engineering and The MOE Key Laboratory of Contemporary Anthropology, School of Life Science, Fudan University, Shanghai 200433 (China)

    2011-06-10

    Highlights: {yields} LNA-modified oligonucleotides can pass through the plasma membrane of cultured cells even without using transfection machinery. {yields} LNA-modified oligonucleotides passed efficiently across the cell membrane, and lipid-coating facilitated translocation from the cytoplasm to the nucleus. {yields} LNA-oligonucleotide designed to target nuclear HBV DNA efficiently suppresses HBV replication and transcription in cultured hepatic cells. -- Abstract: Silencing target genes with small regulatory RNAs is widely used to investigate gene function and therapeutic drug development. Recently, triplex-based approaches have provided another attractive means to achieve targeted gene regulation and gene manipulation at the molecular and cellular levels. Nuclear entry of oligonucleotides and enhancement of their affinity to the DNA targets are key points of such approaches. In this study, we developed lipid-based transport of a locked-nucleic-acid (LNA)-modified oligonucleotide for hepatitis B virus (HBV) DNA interference in human hepatocytes expressing HBV genomic DNA. In these cells, the LNA-modified oligonucleotides passed efficiently across the cell membrane, and lipid-coating facilitated translocation from the cytoplasm to the nucleus. The oligonucleotide specifically targeting HBV DNA clearly interfered with HBV DNA transcription as shown by a block in pregenomic RNA (pgRNA) production. The HBV DNA-targeted oligonucleotide suppressed HBV DNA replication and HBV protein production more efficiently than small interfering RNAs directed to the pgRNA. These results demonstrate that fusion with lipid can carry LNA-modified oligonucleotides to the nucleus where they regulate gene expression. Interfering with HBV DNA transcription by LNA-modified oligonucleotides has strong potential as a new strategy for HBV inhibition.

  1. A Simple Laboratory Practical to Illustrate RNA Mediated Gene Interference Using Drosophila Cell Culture

    Science.gov (United States)

    Buluwela, Laki; Kamalati, Tahereh; Photiou, Andy; Heathcote, Dean A.; Jones, Michael D.; Ali, Simak

    2010-01-01

    RNA mediated gene interference (RNAi) is now a key tool in eukaryotic cell and molecular biology research. This article describes a five session laboratory practical, spread over a seven day period, to introduce and illustrate the technique. During the exercise, students working in small groups purify PCR products that encode "in vitro"…

  2. Production of high-amylose maize lines using RNA interference in ...

    African Journals Online (AJOL)

    amylose maize lines with a low T-DNA copy number, demonstrating that RNAi is an efficient method for the production of high-amylose maize lines. Key words: Maize, high-amylose, RNA interference, starch branching enzyme gene sbe2a.

  3. Negative Priming Effect after Inhibition of Weight/Number Interference in a Piaget-Like Task

    Science.gov (United States)

    Schirlin, Olivier; Houde, Olivier

    2007-01-01

    Piagetian tasks have more to do with the child's ability to inhibit interference than they do with the ability to grasp their underlying logic. Here we used a chronometric paradigm with 11-year-olds, who succeed in Piaget's conservation-of-weight task, to test the role of cognitive inhibition in a priming version of this classical task. The…

  4. Immune modulation through RNA interference-mediated silencing of CD40 in dendritic cells.

    Science.gov (United States)

    Karimi, Mohammad Hossein; Ebadi, Padideh; Pourfathollah, Ali Akbar; Soheili, Zahra Soheila; Samiee, Shahram; Ataee, Zahra; Tabei, Seyyed Ziyaoddin; Moazzeni, Seyed Mohammad

    2009-01-01

    RNA interference (RNAi) is an exciting mechanism for knocking down any target gene in transcriptional level. It is now clear that small interfering RNA (siRNA), a 19-21nt long dsRNA, can trigger a degradation process (RNAi) that specifically silences the expression of a cognate mRNA. Our findings in this study showed that down regulation of CD40 gene expression in dendritic cells (DCs) by RNAi culminated to immune modulation. Effective delivery of siRNA into DCs would be a reasonable method for the blocking of CD40 gene expression at the cell surface without any effect on other genes and cell cytotoxicity. The effects of siRNA against CD40 mRNA on the function and phenotype of DCs were investigated. The DCs were separated from the mice spleen and then cultured in vitro. By the means of Lipofectamine2000, siRNA was delivered to the cells and the efficacy of transfection was estimated by flow cytometry. By Annexine V and Propidium Iodide staining, we could evaluate the transfected cells viability. Also, the mRNA expression and protein synthesis were assessed by real-time PCR and flow cytometry, respectively. Knocking down the CD40 gene in the DCs caused an increase in IL-4 production, decrease in IL-12 production and allostimulation activity. All together, these effects would stimulate Th2 cytokines production from allogenic T-cells in vitro.

  5. Poliovirus RNA synthesis in vitro: structural elements and antibody inhibition

    International Nuclear Information System (INIS)

    Semler, B.L.; Hanecak, R.; Dorner, L.F.; Anderson, C.W.; Wimmer, E.

    1983-01-01

    The poliovirus RNA polymerase complex has been analyzed by immunoautoradiography using antibody probes derived from purified replicase (P3) region viral polypeptides. Antibody preparations made against the polio RNA polymerase, P3-4b, detected a previously unreported cellular protein that copurifies with the RNA polymerase. An IgG fraction purified from rabbit antiserum to polypeptide P3-2, a precursor fo the RNA polymerase, specifically inhibits poliovirus RNA synthesis in vitro. The authors have also immunoprecipitated a 60,000-dalton protein (P3-4a) with antiserum to protein P3-4b and have determined the precise genomic map position of this protein by automated Edman degradation. Protein P3-4a originates by cleavage of the RNA polymerase precursor at a glutamine-glucine amino acid pair not previously reported to be a viral cleavage site

  6. Combining RNA interference and kinase inhibitors against cell signalling components involved in cancer

    International Nuclear Information System (INIS)

    O'Grady, Michael; Raha, Debasish; Hanson, Bonnie J; Bunting, Michaeline; Hanson, George T

    2005-01-01

    The transcription factor activator protein-1 (AP-1) has been implicated in a large variety of biological processes including oncogenic transformation. The tyrosine kinases of the epidermal growth factor receptor (EGFR) constitute the beginning of one signal transduction cascade leading to AP-1 activation and are known to control cell proliferation and differentiation. Drug discovery efforts targeting this receptor and other pathway components have centred on monoclonal antibodies and small molecule inhibitors. Resistance to such inhibitors has already been observed, guiding the prediction of their use in combination therapies with other targeted agents such as RNA interference (RNAi). This study examines the use of RNAi and kinase inhibitors for qualification of components involved in the EGFR/AP-1 pathway of ME180 cells, and their inhibitory effects when evaluated individually or in tandem against multiple components of this important disease-related pathway. AP-1 activation was assessed using an ME180 cell line stably transfected with a beta-lactamase reporter gene under the control of AP-1 response element following epidermal growth factor (EGF) stimulation. Immunocytochemistry allowed for further quantification of small molecule inhibition on a cellular protein level. RNAi and RT-qPCR experiments were performed to assess the amount of knockdown on an mRNA level, and immunocytochemistry was used to reveal cellular protein levels for the targeted pathway components. Increased potency of kinase inhibitors was shown by combining RNAi directed towards EGFR and small molecule inhibitors acting at proximal or distal points in the pathway. After cellular stimulation with EGF and analysis at the level of AP-1 activation using a β-lactamase reporter gene, a 10–12 fold shift or 2.5–3 fold shift toward greater potency in the IC 50 was observed for EGFR and MEK-1 inhibitors, respectively, in the presence of RNAi targeting EGFR. EGFR pathway components were qualified as

  7. Distinct roles for RDE-1 and RDE-4 during RNA interference in Caenorhabditis elegans.

    Science.gov (United States)

    Parrish, S; Fire, A

    2001-10-01

    RNA interference (RNAi) is a cellular defense mechanism that uses double-stranded RNA (dsRNA) as a sequence-specific trigger to guide the degradation of homologous single-stranded RNAs. RNAi is a multistep process involving several proteins and at least one type of RNA intermediate, a population of small 21-25 nt RNAs (called siRNAs) that are initially derived from cleavage of the dsRNA trigger. Genetic screens in Caenorhabditis elegans have identified numerous mutations that cause partial or complete loss of RNAi. In this work, we analyzed cleavage of injected dsRNA to produce the initial siRNA population in animals mutant for rde-1 and rde-4, two genes that are essential for RNAi but that are not required for organismal viability or fertility. Our results suggest distinct roles for RDE-1 and RDE-4 in the interference process. Although null mutants lacking rde-1 show no phenotypic response to dsRNA, the amount of siRNAs generated from an injected dsRNA trigger was comparable to that of wild-type. By contrast, mutations in rde-4 substantially reduced the population of siRNAs derived from an injected dsRNA trigger. Injection of chemically synthesized 24- or 25-nt siRNAs could circumvent RNAi resistance in rde-4 mutants, whereas no bypass was observed in rde-1 mutants. These results support a model in which RDE-4 is involved before or during production of siRNAs, whereas RDE-1 acts after the siRNAs have been formed.

  8. Sequence-specific inhibition of Dicer measured with a force-based microarray for RNA ligands.

    Science.gov (United States)

    Limmer, Katja; Aschenbrenner, Daniela; Gaub, Hermann E

    2013-04-01

    Malfunction of protein translation causes many severe diseases, and suitable correction strategies may become the basis of effective therapies. One major regulatory element of protein translation is the nuclease Dicer that cuts double-stranded RNA independently of the sequence into pieces of 19-22 base pairs starting the RNA interference pathway and activating miRNAs. Inhibiting Dicer is not desirable owing to its multifunctional influence on the cell's gene regulation. Blocking specific RNA sequences by small-molecule binding, however, is a promising approach to affect the cell's condition in a controlled manner. A label-free assay for the screening of site-specific interference of small molecules with Dicer activity is thus needed. We used the Molecular Force Assay (MFA), recently developed in our lab, to measure the activity of Dicer. As a model system, we used an RNA sequence that forms an aptamer-binding site for paromomycin, a 615-dalton aminoglycoside. We show that Dicer activity is modulated as a function of concentration and incubation time: the addition of paromomycin leads to a decrease of Dicer activity according to the amount of ligand. The measured dissociation constant of paromomycin to its aptamer was found to agree well with literature values. The parallel format of the MFA allows a large-scale search and analysis for ligands for any RNA sequence.

  9. RDE-2 interacts with MUT-7 to mediate RNA interference in Caenorhabditis elegans.

    Science.gov (United States)

    Tops, Bastiaan B J; Tabara, Hiroaki; Sijen, Titia; Simmer, Femke; Mello, Craig C; Plasterk, Ronald H A; Ketting, René F

    2005-01-01

    In Caenorhabditis elegans, the activity of transposable elements is repressed in the germline. One of the mechanisms involved in this repression is RNA interference (RNAi), a process in which dsRNA targets cleavage of mRNAs in a sequence-specific manner. The first gene found to be involved in RNAi and transposon silencing in C.elegans is mut-7, a gene encoding a putative exoribonuclease. Here, we show that the MUT-7 protein resides in complexes of approximately 250 kDa in the nucleus and in the cytosol. In addition, we find that upon triggering of RNAi the cytosolic MUT-7 complex increases in size. This increase is independent of the presence of target RNA, but does depend on the presence of RDE-1 and RDE-4, two proteins involved in small interfering RNA (siRNA) production. Finally, using a yeast two-hybrid screen, we identified RDE-2/MUT-8 as one of the other components of this complex. This protein is encoded by the rde-2/mut-8 locus, previously implicated in RNAi and transposon silencing. Using genetic complementation analysis, we show that the interaction between these two proteins is required for efficient RNAi in vivo. Together these data support a role for the MUT-7/RDE-2 complex downstream of siRNA formation, but upstream of siRNA mediated target RNA recognition, possibly indicating a role in the siRNA amplification step.

  10. Thermal Stability of siRNA Modulates Aptamer- conjugated siRNA Inhibition

    Directory of Open Access Journals (Sweden)

    Alexey Berezhnoy

    2012-01-01

    Full Text Available Oligonucleotide aptamer-mediated in vivo cell targeting of small interfering RNAs (siRNAs is emerging as a useful approach to enhance the efficacy and reduce the adverse effects resulting from siRNA-mediated genetic interference. A current main impediment in aptamer-mediated siRNA targeting is that the activity of the siRNA is often compromised when conjugated to an aptamer, often requiring labor intensive and time consuming design and testing of multiple configurations to identify a conjugate in which the siRNA activity has not been significantly reduced. Here, we show that the thermal stability of the siRNA is an important parameter of siRNA activity in its conjugated form, and that siRNAs with lower melting temperature (Tm are not or are minimally affected when conjugated to the 3′ end of 2′F-pyrimidine-modified aptamers. In addition, the configuration of the aptamer-siRNA conjugate retains activity comparable with the free siRNA duplex when the passenger strand is co-transcribed with the aptamer and 3′ overhangs on the passenger strand are removed. The approach described in this paper significantly reduces the time and effort necessary to screening siRNA sequences that retain biological activity upon aptamer conjugation, facilitating the process of identifying candidate aptamer-siRNA conjugates suitable for in vivo testing.

  11. Inhibition of Hepatitis B virus cccDNA replication by siRNA

    International Nuclear Information System (INIS)

    Li Guiqiu; Gu Hongxi; Li Di; Xu Weizhen

    2007-01-01

    The development of an effective therapy for Hepatitis B virus (HBV) infection is still a challenge. Progress in RNA interference (RNAi) has shed slight on developing a new anti-HBV strategy. Here, we present a series of experiments showing a significant reduction in HBV transcripts and replication intermediates in HepG2.2.15 cells by vector-based siRNA targeted nuclear localization signal (NLS) region. More importantly, we showed that siRNA1 markedly inhibited HBV covalently closed circular DNA (cccDNA) replication. Our results indicated that HBV NLS may serve as a novel RNAi target to combat HBV infection, which can enhance anti-HBV efficacy and overcome the drawbacks of current therapies

  12. RNA interference analyses suggest a transcript-specific regulatory role for mitochondrial RNA-binding proteins MRP1 and MRP2 in RNA editing and other RNA processing in Trypanosoma brucei

    NARCIS (Netherlands)

    Vondrusková, Eva; van den Burg, Janny; Zíková, Alena; Ernst, Nancy Lewis; Stuart, Kenneth; Benne, Rob; Lukes, Julius

    2005-01-01

    Mitochondrial RNA-binding proteins MRP1 and MRP2 occur in a heteromeric complex that appears to play a role in U-insertion/deletion editing in trypanosomes. Reduction in the levels of MRP1 (gBP21) and/or MRP2 (gBP25) mRNA by RNA interference in procyclic Trypanosoma brucei resulted in severe growth

  13. Combinatorial RNA Interference Therapy Prevents Selection of Pre-existing HBV Variants in Human Liver Chimeric Mice

    Science.gov (United States)

    Shih, Yao-Ming; Sun, Cheng-Pu; Chou, Hui-Hsien; Wu, Tzu-Hui; Chen, Chun-Chi; Wu, Ping-Yi; Enya Chen, Yu-Chen; Bissig, Karl-Dimiter; Tao, Mi-Hua

    2015-01-01

    Selection of escape mutants with mutations within the target sequence could abolish the antiviral RNA interference activity. Here, we investigated the impact of a pre-existing shRNA-resistant HBV variant on the efficacy of shRNA therapy. We previously identified a highly potent shRNA, S1, which, when delivered by an adeno-associated viral vector, effectively inhibits HBV replication in HBV transgenic mice. We applied the “PICKY” software to systemically screen the HBV genome, then used hydrodynamic transfection and HBV transgenic mice to identify additional six highly potent shRNAs. Human liver chimeric mice were infected with a mixture of wild-type and T472C HBV, a S1-resistant HBV variant, and then treated with a single or combined shRNAs. The presence of T472C mutant compromised the therapeutic efficacy of S1 and resulted in replacement of serum wild-type HBV by T472C HBV. In contrast, combinatorial therapy using S1 and P28, one of six potent shRNAs, markedly reduced titers for both wild-type and T472C HBV. Interestingly, treatment with P28 alone led to the emergence of escape mutants with mutations in the P28 target region. Our results demonstrate that combinatorial RNAi therapy can minimize the escape of resistant viral mutants in chronic HBV patients. PMID:26482836

  14. The Role of RNA Interference (RNAi in Arbovirus-Vector Interactions

    Directory of Open Access Journals (Sweden)

    Carol D. Blair

    2015-02-01

    Full Text Available RNA interference (RNAi was shown over 18 years ago to be a mechanism by which arbovirus replication and transmission could be controlled in arthropod vectors. During the intervening period, research on RNAi has defined many of the components and mechanisms of this antiviral pathway in arthropods, yet a number of unexplored questions remain. RNAi refers to RNA-mediated regulation of gene expression. Originally, the term described silencing of endogenous genes by introduction of exogenous double-stranded (dsRNA with the same sequence as the gene to be silenced. Further research has shown that RNAi comprises three gene regulation pathways that are mediated by small RNAs: the small interfering (siRNA, micro (miRNA, and Piwi-interacting (piRNA pathways. The exogenous (exo-siRNA pathway is now recognized as a major antiviral innate immune response of arthropods. More recent studies suggest that the piRNA and miRNA pathways might also have important roles in arbovirus-vector interactions. This review will focus on current knowledge of the role of the exo-siRNA pathway as an arthropod vector antiviral response and on emerging research into vector piRNA and miRNA pathway modulation of arbovirus-vector interactions. Although it is assumed that arboviruses must evade the vector’s antiviral RNAi response in order to maintain their natural transmission cycles, the strategies by which this is accomplished are not well defined. RNAi is also an important tool for arthropod gene knock-down in functional genomics studies and in development of arbovirus-resistant mosquito populations. Possible arbovirus strategies for evasion of RNAi and applications of RNAi in functional genomics analysis and arbovirus transmission control will also be reviewed.

  15. Vector-based RNA interference against vascular endothelial growth factor-A significantly limits vascularization and growth of prostate cancer in vivo.

    Science.gov (United States)

    Wannenes, Francesca; Ciafré, Silvia Anna; Niola, Francesco; Frajese, Gaetano; Farace, Maria Giulia

    2005-12-01

    RNA interference technology is emerging as a very potent tool to obtain a cellular knockdown of a desired gene. In this work we used vector-based RNA interference to inhibit vascular endothelial growth factor (VEGF) expression in prostate cancer in vitro and in vivo. We demonstrated that transduction with a plasmid carrying a small interfering RNA targeting all isoforms of VEGF, dramatically impairs the expression of this growth factor in the human prostate cancer cell line PC3. As a consequence, PC3 cells loose their ability to induce one of the fundamental steps of angiogenesis, namely the formation of a tube-like network in vitro. Most importantly, our "therapeutic" vector is able to impair tumor growth rate and vascularization in vivo. We show that a single injection of naked plasmid in developing neoplastic mass significantly decreases microvessel density in an androgen-refractory prostate xenograft and is able to sustain a long-term slowing down of tumor growth. In conclusion, our results confirm the basic role of VEGF in the angiogenic development of prostate carcinoma, and suggest that the use of our vector-based RNA interference approach to inhibit angiogenesis could be an effective tool in view of future gene therapy applications for prostate cancer.

  16. Identification of nonviable genes affecting touch sensitivity in Caenorhabditis elegans using neuronally enhanced feeding RNA interference.

    Science.gov (United States)

    Chen, Xiaoyin; Cuadros, Margarete Diaz; Chalfie, Martin

    2015-01-09

    Caenorhabditis elegans senses gentle touch along the body via six touch receptor neurons. Although genetic screens and microarray analyses have identified several genes needed for touch sensitivity, these methods miss pleiotropic genes that are essential for the viability, movement, or fertility of the animals. We used neuronally enhanced feeding RNA interference to screen genes that cause lethality or paralysis when mutated, and we identified 61 such genes affecting touch sensitivity, including five positive controls. We confirmed 18 genes by using available alleles, and further studied one of them, tag-170, now renamed txdc-9. txdc-9 preferentially affects anterior touch response but is needed for tubulin acetylation and microtubule formation in both the anterior and posterior touch receptor neurons. Our results indicate that neuronally enhanced feeding RNA interference screens complement traditional mutageneses by identifying additional nonviable genes needed for specific neuronal functions. Copyright © 2015 Chen et al.

  17. Alfalfa dwarf cytorhabdovirus P protein is a local and systemic RNA silencing supressor which inhibits programmed RISC activity and prevents transitive amplification of RNA silencing.

    Science.gov (United States)

    Bejerman, Nicolás; Mann, Krin S; Dietzgen, Ralf G

    2016-09-15

    Plants employ RNA silencing as an innate defense mechanism against viruses. As a counter-defense, plant viruses have evolved to express RNA silencing suppressor proteins (RSS), which target one or more steps of the silencing pathway. In this study, we show that the phosphoprotein (P) encoded by the negative-sense RNA virus alfalfa dwarf virus (ADV), a species of the genus Cytorhabdovirus, family Rhabdoviridae, is a suppressor of RNA silencing. ADV P has a relatively weak local RSS activity, and does not prevent siRNA accumulation. On the other hand, ADV P strongly suppresses systemic RNA silencing, but does not interfere with the short-distance spread of silencing, which is consistent with its lack of inhibition of siRNA accumulation. The mechanism of suppression appears to involve ADV P binding to RNA-induced silencing complex proteins AGO1 and AGO4 as shown in protein-protein interaction assays when ectopically expressed. In planta, we demonstrate that ADV P likely functions by inhibiting miRNA-guided AGO1 cleavage and prevents transitive amplification by repressing the production of secondary siRNAs. As recently described for lettuce necrotic yellows cytorhabdovirus P, but in contrast to other viral RSS known to disrupt AGO activity, ADV P sequence does not contain any recognizable GW/WG or F-box motifs, which suggests that cytorhabdovirus P proteins may use alternative motifs to bind to AGO proteins. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  18. Separating intentional inhibition of prepotent responses and resistance to proactive interference in alcohol-dependent individuals.

    Science.gov (United States)

    Noël, Xavier; Van der Linden, Martial; Brevers, Damien; Campanella, Salvatore; Verbanck, Paul; Hanak, Catherine; Kornreich, Charles; Verbruggen, Frederick

    2013-03-01

    Impulsivity is a hallmark of addictive behaviors. Addicts' weakened inhibition of irrelevant prepotent responses is commonly thought to explain this association. However, inhibition is not a unitary mechanism. This study investigated the efficiency of overcoming competition due to irrelevant responses (i.e., inhibition of a prepotent response) and overcoming competition in memory (i.e., resistance to proactive interference) in sober and recently detoxified alcohol-dependent individuals. Three cognitive tasks assessing the inhibition of a prepotent response (Hayling task, anti-saccade task and Stroop task) and two tasks tapping into the capacity to resist proactive interference (cued recall, Brown-Peterson variant) were administered to 30 non-amnesic recently detoxified alcohol-dependent individuals and 30 matched healthy participants without alcohol dependency. In addition, possible confounds such as verbal updating in working memory was assessed. Alcohol-dependent subjects performed worse than healthy participants on the three cognitive tasks assessing the inhibition of irrelevant prepotent responses but group performance was similar in the tasks assessing overcoming proactive interference in memory, updating of working memory and abstract reasoning. These findings suggest that alcohol-dependence is mainly associated with impaired capacity to intentionally suppress irrelevant prepotent response information. Control of proactive interference from memory is preserved. Theoretical and clinical implications are discussed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Inhibition of ribosomal RNA synthesis in yeast by ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    Weber, K; Kiefer, J [Giessen Univ. (Germany, F.R.). Strahlenzentrum

    1984-12-01

    Synthesis of ribosomal RNA(r-RNA) was measured for 1 h after exposure of Saccharomyces cerevisiae to ..gamma..-rays, X-rays or ..cap alpha.. particles. ..gamma..- or X-ray induced transcription inhibition was always found to decrease exponentially with dose. D/sub 0/ values of 2150 or 1950 Gy were determined in wild-type cells, corresponding to a mean energy of about 60 eV per r-RNA gene. The finding of differential sensitivities of the two high molecular-weight r-RNA species which are cotranscribed from r-DNA is compatible with the existence of a transcription terminating mechanism. Cells from a mutant strain (rad-9), radiation sensitive to colony forming ability, showed an approximately equal sensitivity for transcription inhibition compared to the wild-type (D/sub 0/ (2095) = 2400 Gy). Inactivation of r-RNA synthesis in cells exposed to ..cap alpha..-particles at room-temperature showed a decreased sensitivity with higher particle fluences ('resistant tail'). This phenomenon was drastically reduced if the temperature during irradiation was lowered to 4/sup 0/C and completely abolished when dried cells were used. An inactivation cross-section for ..cap alpha..-particle induced transcription inhibition of about 0.02 ..mu..m/sup 2/ can be derived from the experimental data.

  20. Small regulatory RNAs of the RNA interference (RNAi) pathway as a prophylactic treatment against fish pathogenic viruses

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Hajiabadi, Seyed Amir Hossein Jalali; Kristensen, Lasse Bøgelund Juel

    2011-01-01

    Small RNAs acting in the recently discovered gene regulatory mechanism called RNA interference has a potential as diagnostic signatures of disease and immunological state and when produced synthetically as prophylactic treatment of such diseases. In the RNAi mechanism the cell produces different....... The mechanism can be programmed with several types of small double stranded RNAs - the type of which defines the destiny of the target. One such class of regulatory RNAs called microRNAs are upregulated due to various physiological responses of the cell and they suppress many genes simultaneously believed...... small RNAs which inhibit gene expression through more or less specific interaction with messenger RNAs resulting in repression of translation to protein. In this way cells can turn of genes of specific pathways thereby leading to altered physiological stages of tissues and possibly of whole organisms...

  1. Shortcomings of short hairpin RNA-based transgenic RNA interference in mouse oocytes

    Czech Academy of Sciences Publication Activity Database

    Sarnová, Lenka; Malík, Radek; Sedláček, Radislav; Svoboda, Petr

    2010-01-01

    Roč. 9, č. 8 (2010), s. 1-10 ISSN 1477-5751 R&D Project s: GA MŠk ME09039 Grant - others:EMBO SDIG(DE) project 1483 Institutional research plan: CEZ:AV0Z50520514 Keywords : transgenic RNAi * shRNA * oocyte Subject RIV: EB - Genetics ; Molecular Biology http://www.jnrbm.com/content/9/1/8

  2. Shortcomings of short hairpin RNA-based transgenic RNA interference in mouse oocytes

    Czech Academy of Sciences Publication Activity Database

    Sarnová, Lenka; Malík, Radek; Sedláček, Radislav; Svoboda, Petr

    2010-01-01

    Roč. 9, č. 8 (2010), s. 1-10 ISSN 1477-5751 R&D Projects: GA MŠk ME09039 Grant - others:EMBO SDIG(DE) project 1483 Institutional research plan: CEZ:AV0Z50520514 Keywords : transgenic RNAi * shRNA * oocyte Subject RIV: EB - Genetics ; Molecular Biology http://www.jnrbm.com/content/9/1/8

  3. Non-Target Effects of Green Fluorescent Protein (GFP-Derived Double-Stranded RNA (dsRNA-GFP Used in Honey Bee RNA Interference (RNAi Assays

    Directory of Open Access Journals (Sweden)

    Francis M. F. Nunes

    2013-01-01

    Full Text Available RNA interference has been frequently applied to modulate gene function in organisms where the production and maintenance of mutants is challenging, as in our model of study, the honey bee, Apis mellifera. A green fluorescent protein (GFP-derived double-stranded RNA (dsRNA-GFP is currently commonly used as control in honey bee RNAi experiments, since its gene does not exist in the A. mellifera genome. Although dsRNA-GFP is not expected to trigger RNAi responses in treated bees, undesirable effects on gene expression, pigmentation or developmental timing are often observed. Here, we performed three independent experiments using microarrays to examine the effect of dsRNA-GFP treatment (introduced by feeding on global gene expression patterns in developing worker bees. Our data revealed that the expression of nearly 1,400 genes was altered in response to dsRNA-GFP, representing around 10% of known honey bee genes. Expression changes appear to be the result of both direct off-target effects and indirect downstream secondary effects; indeed, there were several instances of sequence similarity between putative siRNAs generated from the dsRNA-GFP construct and genes whose expression levels were altered. In general, the affected genes are involved in important developmental and metabolic processes associated with RNA processing and transport, hormone metabolism, immunity, response to external stimulus and to stress. These results suggest that multiple dsRNA controls should be employed in RNAi studies in honey bees. Furthermore, any RNAi studies involving these genes affected by dsRNA-GFP in our studies should use a different dsRNA control.

  4. Non-Target Effects of Green Fluorescent Protein (GFP)-Derived Double-Stranded RNA (dsRNA-GFP) Used in Honey Bee RNA Interference (RNAi) Assays.

    Science.gov (United States)

    Nunes, Francis M F; Aleixo, Aline C; Barchuk, Angel R; Bomtorin, Ana D; Grozinger, Christina M; Simões, Zilá L P

    2013-01-04

    RNA interference has been frequently applied to modulate gene function in organisms where the production and maintenance of mutants is challenging, as in our model of study, the honey bee, Apis mellifera. A green fluorescent protein (GFP)-derived double-stranded RNA (dsRNA-GFP) is currently commonly used as control in honey bee RNAi experiments, since its gene does not exist in the A. mellifera genome. Although dsRNA-GFP is not expected to trigger RNAi responses in treated bees, undesirable effects on gene expression, pigmentation or developmental timing are often observed. Here, we performed three independent experiments using microarrays to examine the effect of dsRNA-GFP treatment (introduced by feeding) on global gene expression patterns in developing worker bees. Our data revealed that the expression of nearly 1,400 genes was altered in response to dsRNA-GFP, representing around 10% of known honey bee genes. Expression changes appear to be the result of both direct off-target effects and indirect downstream secondary effects; indeed, there were several instances of sequence similarity between putative siRNAs generated from the dsRNA-GFP construct and genes whose expression levels were altered. In general, the affected genes are involved in important developmental and metabolic processes associated with RNA processing and transport, hormone metabolism, immunity, response to external stimulus and to stress. These results suggest that multiple dsRNA controls should be employed in RNAi studies in honey bees. Furthermore, any RNAi studies involving these genes affected by dsRNA-GFP in our studies should use a different dsRNA control.

  5. Delivery of small interfering RNA for inhibition of endothelial cell apoptosis by hypoxia and serum deprivation

    International Nuclear Information System (INIS)

    Cho, Seung-Woo; Hartle, Lauren; Son, Sun Mi; Yang, Fan; Goldberg, Michael; Xu, Qiaobing; Langer, Robert; Anderson, Daniel G.

    2008-01-01

    RNA interference (RNAi) for anti-angiogenic or pro-apoptotic factors in endothelial cells (ECs) has great potential for the treatment of ischemic diseases by promoting angiogenesis or inhibiting apoptosis. Here, we report the utility of small interfering RNA (siRNA) in inhibiting EC apoptosis induced by tumor necrosis factor-α (TNF-α). siRNA was designed and synthesized targeting tumor necrosis factor-α receptor-1 (TNFR-1) and Src homology 2 domain-containing protein tyrosine phosphatase-1 (SHP-1). Human umbilical vein endothelial cells (HUVECs) were cultured under in vitro hypoxic and serum-deprived conditions to simulate in vivo ischemic conditions. Two days after liposomal delivery of siRNA targeting TNFR-1 and SHP-1, significant silencing of each target (TNFR-1; 76.5% and SHP-1; 97.2%) was detected. Under serum-deprived hypoxic (1% oxygen) conditions, TNF-α expression in HUVECs increased relative to normoxic (20% oxygen) and serum-containing conditions. Despite enhanced TNF-α expression, suppression of TNFR-1 or SHP-1 by siRNA delivery not only enhanced expression of angiogenic factors (KDR/Flk-1 and eNOS) and anti-apoptotic factor (Bcl-xL) but also reduced expression of a pro-apoptotic factor (Bax). Transfection of TNFR-1 or SHP-1 siRNA significantly decreased the HUVEC apoptosis while significantly enhancing HUVEC proliferation and capillary formation. The present study demonstrates that TNFR-1 and SHP-1 may be useful targets for the treatment of myocardial or hindlimb ischemia

  6. Interference RNA (RNAi)-based silencing of endogenous thrombopoietin receptor (Mpl) in Dami cells resulted in decreased hNUDC-mediated megakaryocyte proliferation and differentiation

    International Nuclear Information System (INIS)

    Pang, Shi-Feng; Li, Xiao-Kun; Zhang, Qiang; Yang, Fang; Xu, Peilin

    2009-01-01

    Recently our laboratory reported evidence showing that hNUDC acts as an additional cytokine for thrombopoietin receptor (Mpl). Previously known as the human homolog of a fungal nuclear migration protein, hNUDC plays a critical role in megakaryocyte differentiation and maturation. Here we sought to further clarify the hNUDC-Mpl ligand-receptor relationship by utilizing interference RNA (RNAi) to knockdown Mpl expression in a megakaryocyte cell line. We created U6 promoter driven constructs to express short hairpin RNAs (shRNA) with affinity for different sites on Mpl mRNA. By including Mpl-EGFP fusion protein in these constructs, we were able to effectively screen the shRNA that was most efficient in inhibiting Mpl mRNA expression. This shRNA was subsequently transferred into a lentivirus vector and transduced into Dami cells, a cell line which constitutively expresses endogenous Mpl. This lentiviral vector was also designed to simultaneously express EGFP to monitor transfection efficiency. Our results show that lentivirus can be used to effectively deliver shRNAs into Dami cells and cause specific inhibition of Mpl protein expression after transduction. Furthermore, we show the functional effects of shRNA-mediated Mpl silencing by demonstrating reduced hNUDC stimulated megakaryocyte proliferation and differentiation. Thus, the use of a RNAi knockdown strategy has allowed us to pinpoint the connection of hNUDC with Mpl in the regulation of megakaryocyte maturation.

  7. Selective Inhibition and Naming Performance in Semantic Blocking, Picture-Word Interference, and Color-Word Stroop Tasks

    Science.gov (United States)

    Shao, Zeshu; Roelofs, Ardi; Martin, Randi C.; Meyer, Antje S.

    2015-01-01

    In 2 studies, we examined whether explicit distractors are necessary and sufficient to evoke selective inhibition in 3 naming tasks: the semantic blocking, picture-word interference, and color-word Stroop task. Delta plots were used to quantify the size of the interference effects as a function of reaction time (RT). Selective inhibition was…

  8. Transgenic Sugarcane Resistant to Sorghum mosaic virus Based on Coat Protein Gene Silencing by RNA Interference

    Directory of Open Access Journals (Sweden)

    Jinlong Guo

    2015-01-01

    Full Text Available As one of the critical diseases of sugarcane, sugarcane mosaic disease can lead to serious decline in stalk yield and sucrose content. It is mainly caused by Potyvirus sugarcane mosaic virus (SCMV and/or Sorghum mosaic virus (SrMV, with additional differences in viral strains. RNA interference (RNAi is a novel strategy for producing viral resistant plants. In this study, based on multiple sequence alignment conducted on genomic sequences of different strains and isolates of SrMV, the conserved region of coat protein (CP genes was selected as the target gene and the interference sequence with size of 423 bp in length was obtained through PCR amplification. The RNAi vector pGII00-HACP with an expression cassette containing both hairpin interference sequence and cp4-epsps herbicide-tolerant gene was transferred to sugarcane cultivar ROC22 via Agrobacterium-mediated transformation. After herbicide screening, PCR molecular identification, and artificial inoculation challenge, anti-SrMV positive transgenic lines were successfully obtained. SrMV resistance rate of the transgenic lines with the interference sequence was 87.5% based on SrMV challenge by artificial inoculation. The genetically modified SrMV-resistant lines of cultivar ROC22 provide resistant germplasm for breeding lines and can also serve as resistant lines having the same genetic background for study of resistance mechanisms.

  9. Identification of chemosensory receptor genes in Manduca sexta and knockdown by RNA interference

    Directory of Open Access Journals (Sweden)

    Howlett Natalie

    2012-05-01

    Full Text Available Abstract Background Insects detect environmental chemicals via a large and rapidly evolving family of chemosensory receptor proteins. Although our understanding of the molecular genetic basis for Drosophila chemoreception has increased enormously in the last decade, similar understanding in other insects remains limited. The tobacco hornworm, Manduca sexta, has long been an important model for insect chemosensation, particularly from ecological, behavioral, and physiological standpoints. It is also a major agricultural pest on solanaceous crops. However, little sequence information and lack of genetic tools has prevented molecular genetic analysis in this species. The ability to connect molecular genetic mechanisms, including potential lineage-specific changes in chemosensory genes, to ecologically relevant behaviors and specializations in M. sexta would be greatly beneficial. Results Here, we sequenced transcriptomes from adult and larval chemosensory tissues and identified chemosensory genes based on sequence homology. We also used dsRNA feeding as a method to induce RNA interference in larval chemosensory tissues. Conclusions We report identification of new chemosensory receptor genes including 17 novel odorant receptors and one novel gustatory receptor. Further, we demonstrate that systemic RNA interference can be used in larval olfactory neurons to reduce expression of chemosensory receptor transcripts. Together, our results further the development of M. sexta as a model for functional analysis of insect chemosensation.

  10. Response inhibition and interference control in obsessive-compulsive spectrum disorders

    Directory of Open Access Journals (Sweden)

    Laura S van Velzen

    2014-06-01

    Full Text Available Over the past twenty years, motor response inhibition and interference control have received considerable scientific effort and attention, due to their important role in behavior and the development of neuropsychiatric disorders. Results of neuroimaging studies indicate that motor response inhibition and interference control are dependent on cortical-striatal-thalamic-cortical (CSTC circuits. Structural and functional abnormalities within the CSTC circuits have been reported for many neuropsychiatric disorders, including obsessive-compulsive disorder (OCD and related disorders, such as attention deficit hyperactivity disorder (ADHD, Tourette’s syndrome (TS and trichotillomania. These disorders also share impairments in motor response inhibition and interference control, which may underlie some of their behavioral and cognitive symptoms. Results of task-related neuroimaging studies on inhibitory functions in these disorders show that impaired task performance is related to altered recruitment of the CSTC circuits. Previous research has shown that inhibitory performance is dependent upon dopamine, noradrenaline and serotonin signaling, neurotransmitters that have been implicated in the pathophysiology of these disorders. In this review we discuss the common and disorder-specific pathophysiological mechanisms of inhibition-related dysfunction in OCD and related disorders.

  11. RNA interference of carboxyesterases causes nymph mortality in the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Kishk, Abdelaziz; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Gowda, Siddarame; Killiny, Nabil

    2017-03-01

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus. In addition, D. citri is the vector of Huanglongbing, a destructive disease in citrus, also known as citrus greening disease caused by Candidatus Liberibacter asiaticus. Huanglongbing causes huge losses for citrus industries. Insecticide application for D. citri is the major strategy to prevent disease spread. The heavy use of insecticides causes development of insecticide resistance. We used RNA interference (RNAi) to silence genes implicated in pesticide resistance in order to increase the susceptibility. The activity of dsRNA to reduce the expression of carboxyesterases including esterases FE4 (EstFE4) and acetylcholinesterases (AChe) in D. citri was investigated. The dsRNA was applied topically to the fourth and fifth instars of nymphs. We targeted several EstFE4 and AChe genes using dsRNA against a consensus sequence for each of them. Five concentrations (25, 50, 75, 100, 125 ng/μl) from both dsRNAs were used. The treatments with the dsRNA caused concentration dependent nymph mortality. The highest gene expression levels of both AChe and EstFE4 were found in the fourth and fifth nymphal instars. Gene expression analysis showed that AChe genes were downregulated in emerged adults from dsRNA-AChe-treated nymphs compared to controls. However, EstFE4 genes were not affected. In the same manner, treatment with dsRNA-EstFE4 reduced expression level of EstFE4 genes in emerged adults from treated nymphs, but did not affect the expression of AChe genes. In the era of environmentally friendly control strategies, RNAi is a new promising venue to reduce pesticide applications. © 2017 Wiley Periodicals, Inc.

  12. HIV-1 RNAs are Not Part of the Argonaute 2 Associated RNA Interference Pathway in Macrophages.

    Directory of Open Access Journals (Sweden)

    Valentina Vongrad

    Full Text Available MiRNAs and other small noncoding RNAs (sncRNAs are key players in post-transcriptional gene regulation. HIV-1 derived small noncoding RNAs (sncRNAs have been described in HIV-1 infected cells, but their biological functions still remain to be elucidated. Here, we approached the question whether viral sncRNAs may play a role in the RNA interference (RNAi pathway or whether viral mRNAs are targeted by cellular miRNAs in human monocyte derived macrophages (MDM.The incorporation of viral sncRNAs and/or their target RNAs into RNA-induced silencing complex was investigated using photoactivatable ribonucleoside-induced cross-linking and immunoprecipitation (PAR-CLIP as well as high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation (HITS-CLIP, which capture Argonaute2-bound miRNAs and their target RNAs. HIV-1 infected monocyte-derived macrophages (MDM were chosen as target cells, as they have previously been shown to express HIV-1 sncRNAs. In addition, we applied small RNA deep sequencing to study differential cellular miRNA expression in HIV-1 infected versus non-infected MDMs.PAR-CLIP and HITS-CLIP data demonstrated the absence of HIV-1 RNAs in Ago2-RISC, although the presence of a multitude of HIV-1 sncRNAs in HIV-1 infected MDMs was confirmed by small RNA sequencing. Small RNA sequencing revealed that 1.4% of all sncRNAs were of HIV-1 origin. However, neither HIV-1 derived sncRNAs nor putative HIV-1 target sequences incorporated into Ago2-RISC were identified suggesting that HIV-1 sncRNAs are not involved in the canonical RNAi pathway nor is HIV-1 targeted by this pathway in HIV-1 infected macrophages.

  13. Knockdown of TFIIS by RNA silencing inhibits cancer cell proliferation and induces apoptosis

    International Nuclear Information System (INIS)

    Hubbard, Kyle; Catalano, Jennifer; Puri, Raj K; Gnatt, Averell

    2008-01-01

    A common element among cancer cells is the presence of improperly controlled transcription. In these cells, the degree of specific activation of some genes is abnormal, and altering the aberrant transcription may therefore directly target cancer. TFIIS is a transcription elongation factor, which directly binds the transcription motor, RNA Polymerase II and allows it to read through various transcription arrest sites. We report on RNA interference of TFIIS, a transcription elongation factor, and its affect on proliferation of cancer cells in culture. RNA interference was performed by transfecting siRNA to specifically knock down TFIIS expression in MCF7, MCF10A, PL45 and A549 cells. Levels of TFIIS expression were determined by the Quantigene method, and relative protein levels of TFIIS, c-myc and p53 were determined by C-ELISA. Induction of apoptosis was determined by an enzymatic Caspase 3/7 assay, as well as a non-enzymatic assay detecting cytoplasmic mono- and oligonucleosomes. A gene array analysis was conducted for effects of TFIIS siRNA on MCF7 and MCF10A cell lines. Knockdown of TFIIS reduced cancer cell proliferation in breast, lung and pancreatic cancer cell lines. More specifically, TFIIS knockdown in the MCF7 breast cancer cell line induced cancer cell death and increased c-myc and p53 expression whereas TFIIS knockdown in the non-cancerous breast cell line MCF10A was less affected. Differential effects of TFIIS knockdown in MCF7 and MCF10A cells included the estrogenic, c-myc and p53 pathways, as observed by C-ELISA and gene array, and were likely involved in MCF7 cell-death. Although transcription is a fundamental process, targeting select core transcription factors may provide for a new and potent avenue for cancer therapeutics. In the present study, knockdown of TFIIS inhibited cancer cell proliferation, suggesting that TFIIS could be studied as a potential cancer target within the transcription machinery

  14. Gene silencing in non-model insects: Overcoming hurdles using symbiotic bacteria for trauma-free sustainable delivery of RNA interference: Sustained RNA interference in insects mediated by symbiotic bacteria: Applications as a genetic tool and as a biocide.

    Science.gov (United States)

    Whitten, Miranda; Dyson, Paul

    2017-03-01

    Insight into animal biology and development provided by classical genetic analysis of the model organism Drosophila melanogaster was an incentive to develop advanced genetic tools for this insect. But genetic systems for the over one million other known insect species are largely undeveloped. With increasing information about insect genomes resulting from next generation sequencing, RNA interference is now the method of choice for reverse genetics, although it is constrained by the means of delivery of interfering RNA. A recent advance to ensure sustained delivery with minimal experimental intervention or trauma to the insect is to exploit commensal bacteria for symbiont-mediated RNA interference. This technology not only offers an efficient means for RNA interference in insects in laboratory conditions, but also has potential for use in the control of human disease vectors, agricultural pests and pathogens of beneficial insects. © 2017 WILEY Periodicals, Inc.

  15. Reversal of pathology in CHMP2B-mediated frontotemporal dementia patient cells using RNA interference

    DEFF Research Database (Denmark)

    Nielsen, Troels Tolstrup; Mizielinska, Sarah; Hasholt, Lis

    2012-01-01

    role in the pathogenesis of the disease. METHODS: In the present study, we used lentiviral vectors to efficiently knockdown CHMP2B by delivering microRNA embedded small hairpin RNAs. RESULTS: We show that CHMP2B can be efficiently knocked down in patient fibroblasts using an RNA interference approach......BACKGROUND: Frontotemporal dementia is the second most common form of young-onset dementia after Alzheimer's disease, and several genetic forms of frontotemporal dementia are known. A rare genetic variant is caused by a point mutation in the CHMP2B gene. CHMP2B is a component of the ESCRT......-III complex, which is involved in endosomal trafficking of proteins targeted for degradation in lysosomes. Mutations in CHMP2B result in abnormal endosomal structures in patient fibroblasts and patient brains, probably through a gain-of-function mechanism, suggesting that the endosomal pathway plays a central...

  16. A fast, simple method for screening radiation susceptibility genes by RNA interference

    International Nuclear Information System (INIS)

    Tsuji, Atsushi B.; Sudo, Hitomi; Sugyo, Aya; Otsuki, Marika; Miyagishi, Makoto; Taira, Kazunari; Imai, Takashi; Harada, Yoshi-nobu

    2005-01-01

    Radiotherapy can cause unacceptable levels of damage to normal tissues in some cancer patients. To understand the molecular mechanisms underlying radiation-induced physiological responses, and to be able to predict the radiation susceptibility of normal tissues in individual patients, it is important to identify a comprehensive set of genes responsible for radiation susceptibility. We have developed a simple and rapid 96-well screening protocol using cell proliferation assays and RNA interference to identify genes associated with radiation susceptibility. We evaluated the performance of alamarBlue-, BrdU-, and sulforhodamine B-based cell proliferation assays using the 96-well format. Each proliferation assay detected the known radiation susceptibility gene, PRKDC. In a trial screen using 28 shRNA vectors, another known gene, CDKN1A, and one new radiation susceptibility gene, ATP5G3, were identified. Our results indicate that this method may be useful for large-scale screens designed to identify novel radiation susceptibility genes

  17. Identification of a novel Drosophila gene, beltless, using injectable embryonic and adult RNA interference (RNAi

    Directory of Open Access Journals (Sweden)

    Manev Hari

    2003-08-01

    Full Text Available Abstract Background RNA interference (RNAi is a process triggered by a double-stranded RNA that leads to targeted down-regulation/silencing of gene expression and can be used for functional genomics; i.e. loss-of-function studies. Here we report on the use of RNAi in the identification of a developmentally important novel Drosophila (fruit fly gene (corresponding to a putative gene CG5652/GM06434, that we named beltless based on an embryonic loss-of-function phenotype. Results Beltless mRNA is expressed in all developmental stages except in 0–6 h embryos. In situ RT-PCR localized beltless mRNA in the ventral cord and brain of late stage embryos and in the nervous system, ovaries, and the accessory glands of adult flies. RNAi was induced by injection of short (22 bp beltless double-stranded RNAs into embryos or into adult flies. Embryonic RNAi altered cuticular phenotypes ranging from partially-formed to missing denticle belts (thus beltless of the abdominal segments A2–A4. Embryonic beltless RNAi was lethal. Adult RNAi resulted in the shrinkage of the ovaries by half and reduced the number of eggs laid. We also examined Df(1RK4 flies in which deletion removes 16 genes, including beltless. In some embryos, we observed cuticular abnormalities similar to our findings with beltless RNAi. After differentiating Df(1RK4 embryos into those with visible denticle belts and those missing denticle belts, we assayed the presence of beltless mRNA; no beltless mRNA was detectable in embryos with missing denticle belts. Conclusions We have identified a developmentally important novel Drosophila gene, beltless, which has been characterized in loss-of-function studies using RNA interference. The putative beltless protein shares homologies with the C. elegans nose resistant to fluoxetine (NRF NRF-6 gene, as well as with several uncharacterized C. elegans and Drosophila melanogaster genes, some with prominent acyltransferase domains. Future studies should

  18. DICER-ARGONAUTE2 complex in continuous fluorogenic assays of RNA interference enzymes.

    Directory of Open Access Journals (Sweden)

    Mark A Bernard

    Full Text Available Mechanistic studies of RNA processing in the RNA-Induced Silencing Complex (RISC have been hindered by lack of methods for continuous monitoring of enzymatic activity. "Quencherless" fluorogenic substrates of RNAi enzymes enable continuous monitoring of enzymatic reactions for detailed kinetics studies. Recombinant RISC enzymes cleave the fluorogenic substrates targeting human thymidylate synthase (TYMS and hypoxia-inducible factor 1-α subunit (HIF1A. Using fluorogenic dsRNA DICER substrates and fluorogenic siRNA, DICER+ARGONAUTE2 mixtures exhibit synergistic enzymatic activity relative to either enzyme alone, and addition of TRBP does not enhance the apparent activity. Titration of AGO2 and DICER in enzyme assays suggests that AGO2 and DICER form a functional high-affinity complex in equimolar ratio. DICER and DICER+AGO2 exhibit Michaelis-Menten kinetics with DICER substrates. However, AGO2 cannot process the fluorogenic siRNA without DICER enzyme, suggesting that AGO2 cannot self-load siRNA into its active site. The DICER+AGO2 combination processes the fluorogenic siRNA substrate (Km=74 nM with substrate inhibition kinetics (Ki=105 nM, demonstrating experimentally that siRNA binds two different sites that affect Dicing and AGO2-loading reactions in RISC. This result suggests that siRNA (product of DICER bound in the active site of DICER may undergo direct transfer (as AGO2 substrate to the active site of AGO2 in the DICER+AGO2 complex. Competitive substrate assays indicate that DICER+AGO2 cleavage of fluorogenic siRNA is specific, since unlabeled siRNA and DICER substrates serve as competing substrates that cause a concentration-dependent decrease in fluorescent rates. Competitive substrate assays of a series of DICER substrates in vitro were correlated with cell-based assays of HIF1A mRNA knockdown (log-log slope=0.29, suggesting that improved DICER substrate designs with 10-fold greater processing by the DICER+AGO2 complex can provide a

  19. Sophoraflavenone G Restricts Dengue and Zika Virus Infection via RNA Polymerase Interference.

    Science.gov (United States)

    Sze, Alexandre; Olagnier, David; Hadj, Samar Bel; Han, Xiaoying; Tian, Xiao Hong; Xu, Hong-Tao; Yang, Long; Shi, Qingwen; Wang, Penghua; Wainberg, Mark A; Wu, Jian Hui; Lin, Rongtuan

    2017-10-03

    Flaviviruses including Zika, Dengue and Hepatitis C virus cause debilitating diseases in humans, and the former are emerging as global health concerns with no antiviral treatments. We investigated Sophora Flavecens , used in Chinese medicine, as a source for antiviral compounds. We isolated Sophoraflavenone G and found that it inhibited Hepatitis C replication, but not Sendai or Vesicular Stomatitis Virus. Pre- and post-infection treatments demonstrated anti-flaviviral activity against Dengue and Zika virus, via viral RNA polymerase inhibition. These data suggest that Sophoraflavenone G represents a promising candidate regarding anti-Flaviviridae research.

  20. RNA interference screen to identify pathways that enhance or reduce nonviral gene transfer during lipofection.

    Science.gov (United States)

    Barker, Gregory A; Diamond, Scott L

    2008-09-01

    Some barriers to DNA lipofection are well characterized; however, there is as yet no method of finding unknown pathways that impact the process. A druggable genome small-interfering RNA (siRNA) screen against 5,520 genes was tested for its effect on lipofection of human aortic endothelial cells (HAECs). We found 130 gene targets which, when silenced by pooled siRNAs (three siRNAs per gene), resulted in enhanced luminescence after lipofection (86 gene targets showed reduced expression). In confirmation tests with single siRNAs, 18 of the 130 hits showed enhanced lipofection with two or more individual siRNAs in the absence of cytotoxicity. Of these confirmed gene targets, we identified five leading candidates, two of which are isoforms of the regulatory subunit of protein phosphatase 2A (PP2A). The best candidate siRNA targeted the PPP2R2C gene and produced a 65% increase in luminescence from lipofection, with a quantitative PCR-validated knockdown of approximately 76%. Flow cytometric analysis confirmed that the silencing of the PPP2R2C gene resulted in an improvement of 10% in transfection efficiency, thereby demonstrating an increase in the number of transfected cells. These results show that an RNA interference (RNAi) high-throughput screen (HTS) can be applied to nonviral gene transfer. We have also demonstrated that siRNAs can be co-delivered with lipofected DNA to increase the transfection efficiency in vitro.

  1. Characterization of the TRBP domain required for Dicer interaction and function in RNA interference

    Directory of Open Access Journals (Sweden)

    El Far Mohamed

    2009-05-01

    Full Text Available Abstract Background Dicer, Ago2 and TRBP are the minimum components of the human RNA-induced silencing complex (RISC. While Dicer and Ago2 are RNases, TRBP is the double-stranded RNA binding protein (dsRBP that loads small interfering RNA into the RISC. TRBP binds directly to Dicer through its C-terminal domain. Results We show that the TRBP binding site in Dicer is a 165 amino acid (aa region located between the ATPase and the helicase domains. The binding site in TRBP is a 69 aa domain, called C4, located at the C-terminal end of TRBP. The TRBP1 and TRBP2 isoforms, but not TRBPs lacking the C4 site (TRBPsΔC4, co-immunoprecipitated with Dicer. The C4 domain is therefore necessary to bind Dicer, irrespective of the presence of RNA. Immunofluorescence shows that while full-length TRBPs colocalize with Dicer, TRBPsΔC4 do not. tarbp2-/- cells, which do not express TRBP, do not support RNA interference (RNAi mediated by short hairpin or micro RNAs against EGFP. Both TRBPs, but not TRBPsΔC4, were able to rescue RNAi function. In human cells with low RNAi activity, addition of TRBP1 or 2, but not TRBPsΔC4, rescued RNAi function. Conclusion The mapping of the interaction sites between TRBP and Dicer show unique domains that are required for their binding. Since TRBPsΔC4 do not interact or colocalize with Dicer, we suggest that TRBP and Dicer, both dsRBPs, do not interact through bound dsRNA. TRBPs, but not TRBPsΔC4, rescue RNAi activity in RNAi-compromised cells, indicating that the binding of Dicer to TRBP is critical for RNAi function.

  2. A large-scale RNA interference screen identifies genes that regulate autophagy at different stages.

    Science.gov (United States)

    Guo, Sujuan; Pridham, Kevin J; Virbasius, Ching-Man; He, Bin; Zhang, Liqing; Varmark, Hanne; Green, Michael R; Sheng, Zhi

    2018-02-12

    Dysregulated autophagy is central to the pathogenesis and therapeutic development of cancer. However, how autophagy is regulated in cancer is not well understood and genes that modulate cancer autophagy are not fully defined. To gain more insights into autophagy regulation in cancer, we performed a large-scale RNA interference screen in K562 human chronic myeloid leukemia cells using monodansylcadaverine staining, an autophagy-detecting approach equivalent to immunoblotting of the autophagy marker LC3B or fluorescence microscopy of GFP-LC3B. By coupling monodansylcadaverine staining with fluorescence-activated cell sorting, we successfully isolated autophagic K562 cells where we identified 336 short hairpin RNAs. After candidate validation using Cyto-ID fluorescence spectrophotometry, LC3B immunoblotting, and quantitative RT-PCR, 82 genes were identified as autophagy-regulating genes. 20 genes have been reported previously and the remaining 62 candidates are novel autophagy mediators. Bioinformatic analyses revealed that most candidate genes were involved in molecular pathways regulating autophagy, rather than directly participating in the autophagy process. Further autophagy flux assays revealed that 57 autophagy-regulating genes suppressed autophagy initiation, whereas 21 candidates promoted autophagy maturation. Our RNA interference screen identifies identified genes that regulate autophagy at different stages, which helps decode autophagy regulation in cancer and offers novel avenues to develop autophagy-related therapies for cancer.

  3. The inhibition of proactive interference among adults with Internet gaming disorder.

    Science.gov (United States)

    Ko, Chih-Hung; Wang, Peng-Wei; Liu, Tai-Ling; Yen, Cheng-Fang; Chen, Cheng-Sheng; Yen, Ju-Yu

    2015-06-01

    Cognitive control plays a pivotal role in the mechanism of addictive behavior. The aim of the study was to evaluate the deficit in inhibition of proactive interference of Internet gaming disorder (IGD) using a directed forgetting task among young adults. A total of 64 participants with IGD and 69 controls were recruited on a university campus. They completed the directed forgetting task for online gaming words and neutral words. The results demonstrated that the IGD group had a poorer performance on the directed forgetting task, and this represented a deficit in inhibition of proactive interference. They also had a higher tendency to remember online gaming words rather than neutral words in comparison with the control group. This demonstrated memory bias toward online gaming words. These results suggested that more attention should be paid to deficits in inhibition of proactive interference and memory bias toward gaming content when treating subjects with IGD. Furthermore, it is essential and practical to prevent exposure to online gaming-related cues when endeavoring to control online gaming behavior. © 2014 Wiley Publishing Asia Pty Ltd.

  4. Selective small-molecule inhibition of an RNA structural element

    Energy Technology Data Exchange (ETDEWEB)

    Howe, John A.; Wang, Hao; Fischmann, Thierry O.; Balibar, Carl J.; Xiao, Li; Galgoci, Andrew M.; Malinverni, Juliana C.; Mayhood, Todd; Villafania, Artjohn; Nahvi, Ali; Murgolo, Nicholas; Barbieri, Christopher M.; Mann, Paul A.; Carr, Donna; Xia, Ellen; Zuck, Paul; Riley, Dan; Painter, Ronald E.; Walker, Scott S.; Sherborne, Brad; de Jesus, Reynalda; Pan, Weidong; Plotkin, Michael A.; Wu, Jin; Rindgen, Diane; Cummings, John; Garlisi, Charles G.; Zhang, Rumin; Sheth, Payal R.; Gill, Charles J.; Tang, Haifeng; Roemer , Terry (Merck)

    2015-09-30

    Riboswitches are non-coding RNA structures located in messenger RNAs that bind endogenous ligands, such as a specific metabolite or ion, to regulate gene expression. As such, riboswitches serve as a novel, yet largely unexploited, class of emerging drug targets. Demonstrating this potential, however, has proven difficult and is restricted to structurally similar antimetabolites and semi-synthetic analogues of their cognate ligand, thus greatly restricting the chemical space and selectivity sought for such inhibitors. Here we report the discovery and characterization of ribocil, a highly selective chemical modulator of bacterial riboflavin riboswitches, which was identified in a phenotypic screen and acts as a structurally distinct synthetic mimic of the natural ligand, flavin mononucleotide, to repress riboswitch-mediated ribB gene expression and inhibit bacterial cell growth. Our findings indicate that non-coding RNA structural elements may be more broadly targeted by synthetic small molecules than previously expected.

  5. RNA interference regulates the cell cycle checkpoint through the RNA export factor, Ptr1, in fission yeast

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Tetsushi, E-mail: tiida@nig.ac.jp [Division of Cytogenetics, National Institute of Genetics, Mishima, 1111 Yata, Mishima 411-8540 (Japan); The Graduate University for Advanced Studies, Sokendai, Mishima, 1111 Yata, Mishima 411-8540 (Japan); Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8, Honcho, Kawaguchi-shi, Saitama 332-0012 (Japan); Iida, Naoko [Division of Mutagenesis, National Institute of Genetics, Mishima, 1111 Yata, Mishima 411-8540 (Japan); Tsutsui, Yasuhiro [Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda-cho, Midori-ku, Yokohama 226-8501 (Japan); Yamao, Fumiaki [Division of Mutagenesis, National Institute of Genetics, Mishima, 1111 Yata, Mishima 411-8540 (Japan); The Graduate University for Advanced Studies, Sokendai, Mishima, 1111 Yata, Mishima 411-8540 (Japan); Kobayashi, Takehiko [Division of Cytogenetics, National Institute of Genetics, Mishima, 1111 Yata, Mishima 411-8540 (Japan); The Graduate University for Advanced Studies, Sokendai, Mishima, 1111 Yata, Mishima 411-8540 (Japan)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer RNAi is linked to the cell cycle checkpoint in fission yeast. Black-Right-Pointing-Pointer Ptr1 co-purifies with Ago1. Black-Right-Pointing-Pointer The ptr1-1 mutation impairs the checkpoint but does not affect gene silencing. Black-Right-Pointing-Pointer ago1{sup +} and ptr1{sup +} regulate the cell cycle checkpoint via the same pathway. Black-Right-Pointing-Pointer Mutations in ago1{sup +} and ptr1{sup +} lead to the nuclear accumulation of poly(A){sup +} RNAs. -- Abstract: Ago1, an effector protein of RNA interference (RNAi), regulates heterochromatin silencing and cell cycle arrest in fission yeast. However, the mechanism by which Ago1 controls cell cycle checkpoint following hydroxyurea (HU) treatment has not been elucidated. In this study, we show that Ago1 and other RNAi factors control cell cycle checkpoint following HU treatment via a mechanism independent of silencing. While silencing requires dcr1{sup +}, the overexpression of ago1{sup +} alleviated the cell cycle defect in dcr1{Delta}. Ago1 interacted with the mRNA export factor, Ptr1. The ptr1-1 mutation impaired cell cycle checkpoint but gene silencing was unaffected. Genetic analysis revealed that the regulation of cell cycle checkpoint by ago1{sup +} is dependent on ptr1{sup +}. Nuclear accumulation of poly(A){sup +} RNAs was detected in mutants of ago1{sup +} and ptr1{sup +}, suggesting there is a functional link between the cell cycle checkpoint and RNAi-mediated RNA quality control.

  6. Noncoding Subgenomic Flavivirus RNA Is Processed by the Mosquito RNA Interference Machinery and Determines West Nile Virus Transmission by Culex pipiens Mosquitoes.

    Science.gov (United States)

    Göertz, G P; Fros, J J; Miesen, P; Vogels, C B F; van der Bent, M L; Geertsema, C; Koenraadt, C J M; van Rij, R P; van Oers, M M; Pijlman, G P

    2016-11-15

    Flaviviruses, such as Zika virus, yellow fever virus, dengue virus, and West Nile virus (WNV), are a serious concern for human health. Flaviviruses produce an abundant noncoding subgenomic flavivirus RNA (sfRNA) in infected cells. sfRNA results from stalling of the host 5'-3' exoribonuclease XRN1/Pacman on conserved RNA structures in the 3' untranslated region (UTR) of the viral genomic RNA. sfRNA production is conserved in insect-specific, mosquito-borne, and tick-borne flaviviruses and flaviviruses with no known vector, suggesting a pivotal role for sfRNA in the flavivirus life cycle. Here, we investigated the function of sfRNA during WNV infection of Culex pipiens mosquitoes and evaluated its role in determining vector competence. An sfRNA1-deficient WNV was generated that displayed growth kinetics similar to those of wild-type WNV in both RNA interference (RNAi)-competent and -compromised mosquito cell lines. Small-RNA deep sequencing of WNV-infected mosquitoes indicated an active small interfering RNA (siRNA)-based antiviral response for both the wild-type and sfRNA1-deficient viruses. Additionally, we provide the first evidence that sfRNA is an RNAi substrate in vivo Two reproducible small-RNA hot spots within the 3' UTR/sfRNA of the wild-type virus mapped to RNA stem-loops SL-III and 3' SL, which stick out of the three-dimensional (3D) sfRNA structure model. Importantly, we demonstrate that sfRNA-deficient WNV displays significantly decreased infection and transmission rates in vivo when administered via the blood meal. Finally, we show that transmission and infection rates are not affected by sfRNA after intrathoracic injection, thereby identifying sfRNA as a key driver to overcome the mosquito midgut infection barrier. This is the first report to describe a key biological function of sfRNA for flavivirus infection of the arthropod vector, providing an explanation for the strict conservation of sfRNA production. Understanding the flavivirus transmission

  7. C6/36 Aedes albopictus cells have a dysfunctional antiviral RNA interference response.

    Directory of Open Access Journals (Sweden)

    Doug E Brackney

    2010-10-01

    Full Text Available Mosquitoes rely on RNA interference (RNAi as their primary defense against viral infections. To this end, the combination of RNAi and invertebrate cell culture systems has become an invaluable tool in studying virus-vector interactions. Nevertheless, a recent study failed to detect an active RNAi response to West Nile virus (WNV infection in C6/36 (Aedes albopictus cells, a mosquito cell line frequently used to study arthropod-borne viruses (arboviruses. Therefore, we sought to determine if WNV actively evades the host's RNAi response or if C6/36 cells have a dysfunctional RNAi pathway. C6/36 and Drosophila melanogaster S2 cells were infected with WNV (Flaviviridae, Sindbis virus (SINV, Togaviridae and La Crosse virus (LACV, Bunyaviridae and total RNA recovered from cell lysates. Small RNA (sRNA libraries were constructed and subjected to high-throughput sequencing. In S2 cells, virus-derived small interfering RNAs (viRNAs from all three viruses were predominantly 21 nt in length, a hallmark of the RNAi pathway. However, in C6/36 cells, viRNAs were primarily 17 nt in length from WNV infected cells and 26-27 nt in length in SINV and LACV infected cells. Furthermore, the origin (positive or negative viral strand and distribution (position along viral genome of S2 cell generated viRNA populations was consistent with previously published studies, but the profile of sRNAs isolated from C6/36 cells was altered. In total, these results suggest that C6/36 cells lack a functional antiviral RNAi response. These findings are analogous to the type-I interferon deficiency described in Vero (African green monkey kidney cells and suggest that C6/36 cells may fail to accurately model mosquito-arbovirus interactions at the molecular level.

  8. CasA mediates Cas3-catalyzed target degradation during CRISPR RNA-guided interference.

    Science.gov (United States)

    Hochstrasser, Megan L; Taylor, David W; Bhat, Prashant; Guegler, Chantal K; Sternberg, Samuel H; Nogales, Eva; Doudna, Jennifer A

    2014-05-06

    In bacteria, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) DNA-targeting complex Cascade (CRISPR-associated complex for antiviral defense) uses CRISPR RNA (crRNA) guides to bind complementary DNA targets at sites adjacent to a trinucleotide signature sequence called the protospacer adjacent motif (PAM). The Cascade complex then recruits Cas3, a nuclease-helicase that catalyzes unwinding and cleavage of foreign double-stranded DNA (dsDNA) bearing a sequence matching that of the crRNA. Cascade comprises the CasA-E proteins and one crRNA, forming a structure that binds and unwinds dsDNA to form an R loop in which the target strand of the DNA base pairs with the 32-nt RNA guide sequence. Single-particle electron microscopy reconstructions of dsDNA-bound Cascade with and without Cas3 reveal that Cascade positions the PAM-proximal end of the DNA duplex at the CasA subunit and near the site of Cas3 association. The finding that the DNA target and Cas3 colocalize with CasA implicates this subunit in a key target-validation step during DNA interference. We show biochemically that base pairing of the PAM region is unnecessary for target binding but critical for Cas3-mediated degradation. In addition, the L1 loop of CasA, previously implicated in PAM recognition, is essential for Cas3 activation following target binding by Cascade. Together, these data show that the CasA subunit of Cascade functions as an essential partner of Cas3 by recognizing DNA target sites and positioning Cas3 adjacent to the PAM to ensure cleavage.

  9. Differential Contribution of RNA Interference Components in Response to Distinct Fusarium graminearum Virus Infections.

    Science.gov (United States)

    Yu, Jisuk; Lee, Kyung-Mi; Cho, Won Kyong; Park, Ju Yeon; Kim, Kook-Hyung

    2018-05-01

    The mechanisms of RNA interference (RNAi) as a defense response against viruses remain unclear in many plant-pathogenic fungi. In this study, we used reverse genetics and virus-derived small RNA profiling to investigate the contributions of RNAi components to the antiviral response against Fusarium graminearum viruses 1 to 3 (FgV1, -2, and -3). Real-time reverse transcription-quantitative PCR (qRT-PCR) indicated that infection of Fusarium graminearum by FgV1, -2, or -3 differentially induces the gene expression of RNAi components in F. graminearum Transcripts of the DICER-2 and AGO-1 genes of F. graminearum ( FgDICER-2 and FgAGO-1 ) accumulated at lower levels following FgV1 infection than following FgV2 or FgV3 infection. We constructed gene disruption and overexpression mutants for each of the Argonaute and dicer genes and for two RNA-dependent RNA polymerase (RdRP) genes and generated virus-infected strains of each mutant. Interestingly, mycelial growth was significantly faster for the FgV1-infected FgAGO-1 overexpression mutant than for the FgV1-infected wild type, while neither FgV2 nor FgV3 infection altered the colony morphology of the gene deletion and overexpression mutants. FgV1 RNA accumulation was significantly decreased in the FgAGO-1 overexpression mutant. Furthermore, the levels of induction of FgAGO-1 , FgDICER-2 , and some of the FgRdRP genes caused by FgV2 and FgV3 infection were similar to those caused by hairpin RNA-induced gene silencing. Using small RNA sequencing analysis, we documented different patterns of virus-derived small interfering RNA (vsiRNA) production in strains infected with FgV1, -2, and -3. Our results suggest that the Argonaute protein encoded by FgAGO-1 is required for RNAi in F. graminearum , that FgAGO-1 induction differs in response to FgV1, -2, and -3, and that FgAGO-1 might contribute to the accumulation of vsiRNAs in FgV1-infected F. graminearum IMPORTANCE To increase our understanding of how RNAi components in Fusarium

  10. Cellular toxicity following application of adeno-associated viral vector-mediated RNA interference in the nervous system

    Directory of Open Access Journals (Sweden)

    Verhaagen Joost

    2010-02-01

    Full Text Available Abstract Background After a spinal cord lesion, axon regeneration is inhibited by the presence of a diversity of inhibitory molecules in the lesion environment. At and around the lesion site myelin-associated inhibitors, chondroitin sulfate proteoglycans (CSPGs and several axon guidance molecules, including all members of the secreted (class 3 Semaphorins, are expressed. Interfering with multiple inhibitory signals could potentially enhance the previously reported beneficial effects of blocking single molecules. RNA interference (RNAi is a tool that can be used to simultaneously silence expression of multiple genes. In this study we aimed to employ adeno-associated virus (AAV mediated expression of short hairpin RNAs (shRNAs to target all Semaphorin class 3 signaling by knocking down its receptors, Neuropilin 1 (Npn-1 and Neuropilin 2 (Npn-2. Results We have successfully generated shRNAs that knock down Npn-1 and Npn-2 in a neuronal cell line. We detected substantial knockdown of Npn-2 mRNA when AAV5 viral vector particles expressing Npn-2 specific shRNAs were injected in dorsal root ganglia (DRG of the rat. Unexpectedly however, AAV1-mediated expression of Npn-2 shRNAs and a control shRNA in the red nucleus resulted in an adverse tissue response and neuronal degeneration. The observed toxicity was dose dependent and was not seen with control GFP expressing AAV vectors, implicating the shRNAs as the causative toxic agents. Conclusions RNAi is a powerful tool to knock down Semaphorin receptor expression in neuronal cells in vitro and in vivo. However, when shRNAs are expressed at high levels in CNS neurons, they trigger an adverse tissue response leading to neuronal degradation.

  11. RNA Interference: A Novel Source of Resistance to Combat Plant Parasitic Nematodes

    Directory of Open Access Journals (Sweden)

    Sagar Banerjee

    2017-05-01

    Full Text Available Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances like RNA interference (RNAi to engineer resistance against these devastating parasites. First demonstrated in the model free living nematode, Caenorhabtidis elegans; the phenomenon of RNAi has been successfully used to suppress essential genes of plant parasitic nematodes involved in parasitism, nematode development and mRNA metabolism. Synthetic neurotransmitants mixed with dsRNA solutions are used for in vitro RNAi in plant parasitic nematodes with significant success. However, host delivered in planta RNAi has proved to be a pioneering phenomenon to deliver dsRNAs to feeding nematodes and silence the target genes to achieve resistance. Highly enriched genomic databases are exploited to limit off target effects and ensure sequence specific silencing. Technological advances like gene stacking and use of nematode inducible and tissue specific promoters can further enhance the utility of RNAi based transgenics against plant parasitic nematodes.

  12. RNA-binding protein Dnd1 inhibits microRNA access to target mRNA

    DEFF Research Database (Denmark)

    Kedde, Martijn; Strasser, Markus J; Boldajipour, Bijan

    2007-01-01

    MicroRNAs (miRNAs) are inhibitors of gene expression capable of controlling processes in normal development and cancer. In mammals, miRNAs use a seed sequence of 6-8 nucleotides (nt) to associate with 3' untranslated regions (3'UTRs) of mRNAs and inhibit their expression. Intriguingly, occasionally...

  13. PsOr1, a potential target for RNA interference-based pest management.

    Science.gov (United States)

    Zhao, Y Y; Liu, F; Yang, G; You, M S

    2011-02-01

    Insect pests cause billions of dollars in agricultural losses, and attempts to kill them have resulted in growing threats from insecticide resistance, dietary pesticide pollution and environmental destruction. New approaches to control refractory insect pests are therefore needed. The host-plant preferences of insect pests rely on olfaction and are mediated via a seven transmembrane-domain odorant receptor (Or) family. The present study reports the cloning and characterization of PsOr1, the first candidate member of the Or gene family from Phyllotreta striolata, a devastating beetle pest that causes damage worldwide. PsOr1 is remarkably well conserved with respect to other insect orthologues, including DmOr83b from Drosophila melanogaster. These insect orthologues form an essential non-conventional Or sub-family and may play an important and generalized role in insect olfaction. We designed double-stranded (ds) RNA directly against the PsOr1 gene and exploited RNA interference (RNAi) to control P. striolata. The chemotactic behavioural measurements showed that adult beetles were unable to sense the attractant or repellent odour stimulus after microinjection of dsRNA against PsOr1. Reverse Transcription (RT)-PCR analysis showed specific down-regulation of mRNA transcript levels for this gene. Furthermore, host-plant preference experiments confirmed that silencing PsOr1 by RNAi treatment impaired the host-plant preferences of P. striolata for cruciferous vegetables. These results demonstrate that this insect control approach of using RNAi to target PsOr1 and its orthologues might be effective in blocking host-plant-seeking behaviours in diverse insect pests. The results also support the theory that this unique receptor type plays an essential general role in insect olfaction. © 2010 Fujian Agriculture and Forestry University. Insect Molecular Biology © 2010 The Royal Entomological Society.

  14. Aedes aegypti uses RNA interference in defense against Sindbis virus infection.

    Science.gov (United States)

    Campbell, Corey L; Keene, Kimberly M; Brackney, Douglas E; Olson, Ken E; Blair, Carol D; Wilusz, Jeffrey; Foy, Brian D

    2008-03-17

    RNA interference (RNAi) is an important anti-viral defense mechanism. The Aedes aegypti genome encodes RNAi component orthologs, however, most populations of this mosquito are readily infected by, and subsequently transmit flaviviruses and alphaviruses. The goal of this study was to use Ae. aegypti as a model system to determine how the mosquito's anti-viral RNAi pathway interacts with recombinant Sindbis virus (SINV; family Togaviridae, genus Alphavirus). SINV (TR339-eGFP) (+) strand RNA, infectious virus titers and infection rates transiently increased in mosquitoes following dsRNA injection to cognate Ago2, Dcr2, or TSN mRNAs. Detection of SINV RNA-derived small RNAs at 2 and 7 days post-infection in non-silenced mosquitoes provided important confirmation of RNAi pathway activity. Two different recombinant SINV viruses (MRE16-eGFP and TR339-eGFP) with significant differences in infection kinetics were used to delineate vector/virus interactions in the midgut. We show virus-dependent effects on RNAi component transcript and protein levels during infection. Monitoring midgut Ago2, Dcr2, and TSN transcript levels during infection revealed that only TSN transcripts were significantly increased in midguts over blood-fed controls. Ago2 protein levels were depleted immediately following a non-infectious bloodmeal and varied during SINV infection in a virus-dependent manner. We show that silencing RNAi components in Ae. aegypti results in transient increases in SINV replication. Furthermore, Ae. aegypti RNAi is active during SINV infection as indicated by production of virus-specific siRNAs. Lastly, the RNAi response varies in a virus-dependent manner. These data define important features of RNAi anti-viral defense in Ae. aegypti.

  15. Illuminating the gateway of gene silencing: perspective of RNA interference technology in clinical therapeutics.

    Science.gov (United States)

    Sindhu, Annu; Arora, Pooja; Chaudhury, Ashok

    2012-07-01

    A novel laboratory revolution for disease therapy, the RNA interference (RNAi) technology, has adopted a new era of molecular research as the next generation "Gene-targeted prophylaxis." In this review, we have focused on the chief technological challenges associated with the efforts to develop RNAi-based therapeutics that may guide the biomedical researchers. Many non-curable maladies, like neurodegenerative diseases and cancers have effectively been cured using this technology. Rapid advances are still in progress for the development of RNAi-based technologies that will be having a major impact on medical research. We have highlighted the recent discoveries associated with the phenomenon of RNAi, expression of silencing molecules in mammals along with the vector systems used for disease therapeutics.

  16. Improvement of heterologous protein production in Aspergillus oryzae by RNA interference with alpha-amylase genes.

    Science.gov (United States)

    Nemoto, Takashi; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

    2009-11-01

    Aspergillus oryzae RIB40 has three alpha-amylase genes (amyA, amyB, and amyC), and secretes alpha-amylase abundantly. However, large amounts of endogenous secretory proteins such as alpha-amylase can compete with heterologous protein in the secretory pathway and decrease its production yields. In this study, we examined the effects of suppression of alpha-amylase on heterologous protein production in A. oryzae, using the bovine chymosin (CHY) as a reporter heterologous protein. The three alpha-amylase genes in A. oryzae have nearly identical DNA sequences from those promoters to the coding regions. Hence we performed silencing of alpha-amylase genes by RNA interference (RNAi) in the A. oryzae CHY producing strain. The silenced strains exhibited a reduction in alpha-amylase activity and an increase in CHY production in the culture medium. This result suggests that suppression of alpha-amylase is effective in heterologous protein production in A. oryzae.

  17. Downregulation of telomerase activity in human promyelocytic cell line using RNA interference.

    Science.gov (United States)

    Miri-Moghaddam, E; Deezagi, A; Soheili, Z S

    2009-12-01

    Telomerase is a ribonucleoprotein complex. It consists of two main components, human telomerase reverse transcriptase (hTERT) and human telomerase RNA. High telomerase activity is present in most malignant cells, but it is barely detectable in majority of somatic cells. The direct correlation between telomerase reactivation and carcinogens has made hTERT a key target for anticancer therapeutic studies. In this study, for the first time, we evaluated the ability of the new generation of short interfering RNA (siRNA) to regulate telomerase activity in the human promyelocytic leukemia cell line (HL-60). Transient transfection cell line by hTERT siRNAs resulted in statistically significant suppression of hTERT messenger RNAs which were detected by quantitative real-time polymerase chain reaction, while the expressed hTERT protein levels were measured by flow cytometry. The results of telomeric repeat amplification protocol showed that telomerase activity was significantly reduced upon transfection of the HL-60 cell line with hTERT siRNAs. The results of this study showed that telomerase activity and cell proliferation were efficiently inhibited in the hTERT siRNA-treated leukemic cell line.

  18. Leptin interferes with 3',5'-Cyclic Adenosine Monophosphate (cAMP signaling to inhibit steroidogenesis in human granulosa cells

    Directory of Open Access Journals (Sweden)

    HoYuen Basil

    2009-10-01

    Full Text Available Abstract Background Obesity has been linked to an increased risk of female infertility. Leptin, an adipocytokine which is elevated during obesity, may influence gonadal function through modulating steroidogenesis in granulosa cells. Methods The effect of leptin on progesterone production in simian virus 40 immortalized granulosa (SVOG cells was examined by Enzyme linked immunosorbent assay (ELISA. The effect of leptin on the expression of the steroidogenic enzymes (StAR, P450scc, 3betaHSD in SVOG cells was examined by real-time PCR and Western blotting. The mRNA expression of leptin receptor isoforms in SVOG cells were examined by using PCR. SVOG cells were co-treated with leptin and specific pharmacological inhibitors to identify the signaling pathways involved in leptin-reduced progesterone production. Silencing RNA against leptin receptor was used to determine that the inhibition of leptin on cAMP-induced steroidogenesis acts in a leptin receptor-dependent manner. Results and Conclusion In the present study, we investigated the cellular mechanisms underlying leptin-regulated steroidogenesis in human granulosa cells. We show that leptin inhibits 8-bromo cAMP-stimulated progesterone production in a concentration-dependent manner. Furthermore, we show that leptin inhibits expression of the cAMP-stimulated steroidogenic acute regulatory (StAR protein, the rate limiting de novo protein in progesterone synthesis. Leptin induces the activation of ERK1/2, p38 and JNK but only the ERK1/2 (PD98059 and p38 (SB203580 inhibitors attenuate the leptin-induced inhibition of cAMP-stimulated StAR protein expression and progesterone production. These data suggest that the leptin-induced MAPK signal transduction pathway interferes with cAMP/PKA-stimulated steroidogenesis in human granulosa cells. Moreover, siRNA mediated knock-down of the endogenous leptin receptor attenuates the effect of leptin on cAMP-induced StAR protein expression and progesterone

  19. SiRNA-mediated IGF-1R inhibition sensitizes human colon cancer SW480 cells to radiation

    International Nuclear Information System (INIS)

    Yavari, Kamal; Taghikhani, Mohammad; Mesbah-Namin, Seyed A.; Maragheh, Mohammad Ghannadi; Babaei, Mohammad Hosein; Arfaee, Ali Jabbary; Madani, Hossein; Mirzaei, Hamid Reza

    2010-01-01

    Purpose. Insulin like growth factor receptor 1 (IGF-1R) is well-documented to play a key role in radiation response and tumor radiosensitivity, thus offering an attractive clinic drug target to enhance tumor sensitivity to anti-cancer radiotherapy. Material and methods. Human colon carcinoma SW480 cells were transfected with the specific small interference RNA (siRNA) expression vector (pkD-shRNA-IGF-1R-V2) designed to target IGF-1R mRNA. The expression of IGF-1R mRNA and its protein among the transfected and untransfected cells were detected by semi-quantitative RT-PCR and ELISA assay. The changes in cell radiosensitivity were examined by MTT assay. Results. Transfection of mammalian expression vector pkD containing IGF-1R siRNA was shown to reduce IGF-1R mRNA levels by up to 95%. ELISA assay detected a similar inhibition of IGF-1R protein levels in cells transfected with IGF-1R siRNA. SW480 cells transfected with the expression vector for siRNA significantly rendered cells more sensitive to radiation and the highest radiation enhancement ratio was 2.02 ± 0.08. Conclusion. These data provide the first evidence that specific siRNA fragment (pkD-shRNA-IGF-1R-V2) targeting human IGF-1R mRNA is able to enhance colon cancer radiosensitivity. Also results indicated that, combining IGF-1R siRNA and radiation significantly enhances antitumor efficacy compared with either modality alone

  20. Stable RNA interference of ErbB-2 gene synergistic with epirubicin suppresses breast cancer growth in vitro and in vivo

    International Nuclear Information System (INIS)

    Hu Xiaoqu; Su Fengxi; Qin Li; Jia Weijuan; Gong Chang; Yu Fengyan; Guo Jujiang; Song Erwei

    2006-01-01

    Overexpression of human epidermal growth factor receptor-2 (Her2, ErbB-2) contributes to the progression and metastasis of breast cancer, implying that Her2 gene is a suitable target of RNA interference (RNAi) for breast cancer therapy. Here, we employed plasmid-mediated expression of 2 different Her2-shRNAs (pU6-Her2shRNAs) efficiently silenced the target gene expression on Her2 expressing SKBR-3 breast cancer cells in both mRNA and protein levels. Consequently, pU6-Her2shRNA increased apoptosis and reduced proliferation of SKBR-3 cells assayed by TUNEL and MTT, respectively. In vivo, intra-tumor injection of pU6-Her2shRNA inhibited the growth of SKBR-3 tumors inoculated subcutaneously in nude mice. Furthermore, pU6-Her2shRNA synergized the tumor suppression effect of epirubicin to SKBR-3 cells in vitro and implanted subcutaneously in nude mice. Therefore, we concluded that stable silencing of Her2 gene expression with plasmid expressing shRNA may hold great promise as a novel therapy for Her2 expressing breast cancers alone or in combination with anthracycline chemotherapy

  1. Chimeric peptide-mediated siRNA transduction to inhibit HIV-1 infection.

    Science.gov (United States)

    Bivalkar-Mehla, Shalmali; Mehla, Rajeev; Chauhan, Ashok

    2017-04-01

    Persistent human immunodeficiency virus 1 (HIV-1) infection provokes immune activation and depletes CD4 +  lymphocytes, leading to acquired immunodeficiency syndrome. Uninterrupted administration of combination antiretroviral therapy (cART) in HIV-infected patients suppresses viral replication to below the detectable level and partially restores the immune system. However, cART-unresponsive residual HIV-1 infection and elusive transcriptionally silent but reactivatable viral reservoirs maintain a permanent viral DNA blue print. The virus rebounds within a few weeks after interruption of suppressive therapy. Adjunct gene therapy to control viral replication by ribonucleic acid interference (RNAi) is a post-transcriptional gene silencing strategy that could suppress residual HIV-1 burden and overcome viral resistance. Small interfering ribonucleic acids (siRNAs) are efficient transcriptional inhibitors, but need delivery systems to reach inside target cells. We investigated the potential of chimeric peptide (FP-PTD) to deliver specific siRNAs to HIV-1-susceptible and permissive cells. Chimeric FP-PTD peptide was designed with an RNA binding domain (PTD) to bind siRNA and a cell fusion peptide domain (FP) to enter cells. FP-PTD-siRNA complex entered and inhibited HIV-1 replication in susceptible cells, and could be a candidate for in vivo testing.

  2. RNA interference and retinoblastoma-related genes are required for repression of endogenous siRNA targets in Caenorhabditis elegans.

    Science.gov (United States)

    Grishok, Alla; Hoersch, Sebastian; Sharp, Phillip A

    2008-12-23

    In Caenorhabditis elegans, a vast number of endogenous short RNAs corresponding to thousands of genes have been discovered recently. This finding suggests that these short interfering RNAs (siRNAs) may contribute to regulation of many developmental and other signaling pathways in addition to silencing viruses and transposons. Here, we present a microarray analysis of gene expression in RNA interference (RNAi)-related mutants rde-4, zfp-1, and alg-1 and the retinoblastoma (Rb) mutant lin-35. We found that a component of Dicer complex RDE-4 and a chromatin-related zinc finger protein ZFP-1, not implicated in endogenous RNAi, regulate overlapping sets of genes. Notably, genes a) up-regulated in the rde-4 and zfp-1 mutants and b) up-regulated in the lin-35(Rb) mutant, but not the down-regulated genes are highly represented in the set of genes with corresponding endogenous siRNAs (endo-siRNAs). Our study suggests that endogenous siRNAs cooperate with chromatin factors, either C. elegans ortholog of acute lymphoblastic leukemia-1 (ALL-1)-fused gene from chromosome 10 (AF10), ZFP-1, or tumor suppressor Rb, to regulate overlapping sets of genes and predicts a large role for RNAi-based chromatin silencing in control of gene expression in C. elegans.

  3. Proactive interference by cues presented without outcomes: Differences in context specificity of latent inhibition and conditioned inhibition.

    Science.gov (United States)

    Miguez, Gonzalo; McConnell, Bridget; Polack, Cody W; Miller, Ralph R

    2018-01-08

    This report is part of a larger project examining associative interference as a function of the nature of the interfering and target associations. Lick suppression experiments with rats assessed the effects of context shifts on proactive outcome interference by latent inhibition (LI) and Pavlovian conditioned inhibition (CI) treatments on subsequently trained Pavlovian conditioned excitation treatment. LI and CI were trained in Context A during Phase 1, and then excitation treatment was administered in Context B during Phase 2, followed by tests for conditioned excitation in Contexts A, B, or C. Experiment 1 preliminarily established our LI and CI treatments and resulted in equally retarded acquisition of behavioral control when the target cue was subsequently trained as a conditioned excitor and tested in Context A. However, only CI treatment caused the target to pass a summation test for inhibition. Centrally, Experiment 2 consisted of LI and CI treatments in Context A followed by excitatory training in Context B. Testing found low excitatory control by both LI and CI cues in Context A relative to strong excitatory control in Context B, but CI treatment transferred to Context C more strongly than LI treatment. Experiment 3 determined that LI treatment failed to transfer to Context C even when the number of LI trials was greatly increased. Thus, first-learned LI appears to be relatively context specific, whereas first-learned CI generalizes to a neutral context. These observations add to existing evidence that LI and CI treatments result in different types of learning that diverge sharply in transfer to a novel test context.

  4. Silencing VDAC1 Expression by siRNA Inhibits Cancer Cell Proliferation and Tumor Growth In Vivo

    Directory of Open Access Journals (Sweden)

    Tasleem Arif

    2014-01-01

    Full Text Available Alterations in cellular metabolism and bioenergetics are vital for cancer cell growth and motility. Here, the role of the mitochondrial protein voltage-dependent anion channel (VDAC1, a master gatekeeper regulating the flux of metabolites and ions between mitochondria and the cytoplasm, in regulating the growth of several cancer cell lines was investigated by silencing VDAC1 expression using small interfering RNA (siRNA. A single siRNA specific to the human VDAC1 sequence at nanomolar concentrations led to some 90% decrease in VDAC1 levels in the lung A549 and H358, prostate PC-3, colon HCT116, glioblastoma U87, liver HepG2, and pancreas Panc-1 cancer cell lines. VDAC1 silencing persisted 144 hours post-transfection and resulted in profound inhibition of cell growth in cancer but not in noncancerous cells, with up to 90% inhibition being observed over 5 days that was prolonged by a second transfection. Cells expressing low VDAC1 levels showed decreased mitochondrial membrane potential and adenoside triphosphate (ATP levels, suggesting limited metabolite exchange between mitochondria and cytosol. Moreover, cells silenced for VDAC1 expression showed decreased migration, even in the presence of the wound healing accelerator basic fibroblast growth factor (bFGF. VDAC1-siRNA inhibited cancer cell growth in a Matrigel-based assay in host nude mice. Finally, in a xenograft lung cancer mouse model, chemically modified VDAC1-siRNA not only inhibited tumor growth but also resulted in tumor regression. This study thus shows that VDAC1 silencing by means of RNA interference (RNAi dramatically inhibits cancer cell growth and tumor development by disabling the abnormal metabolic behavior of cancer cells, potentially paving the way for a more effective pipeline of anticancer drugs.

  5. RNA interference: a promising technique for the improvement of traditional crops.

    Science.gov (United States)

    Katoch, Rajan; Thakur, Neelam

    2013-03-01

    RNA interference (RNAi) is a homology-dependent gene-silencing technology that involves double-stranded RNA directed against a target gene. This technique has emerged as powerful tool in understanding the functions of a number of genes in recent years. For the improvement in the nutritional status of the plants and reduction in the level of antinutrients, the conventional breeding methods were not completely successful in achieving the tissue-specific regulation of some genes. RNAi has shown successful results in a number of plant species for nutritional improvement, change in morphology and alteration in metabolite synthesis. This technology has been applied mostly in genetic engineering of important crop plants, and till date there are no reports of its application for the improvement of traditional/underutilized crops. In this study, we discuss current knowledge of RNAi function and concept and strategies for the improvement of traditional crops. Practical application. Although RNAi has been extensively used for the improvement of popular crops, no attention has been given for the use of this technology for the improvement of underutilized crops. This study describes the importance of use of this technology for the improvement of underutilized crops.

  6. Interspecific RNA interference of SHOOT MERISTEMLESS-like disrupts Cuscuta pentagona plant parasitism.

    Science.gov (United States)

    Alakonya, Amos; Kumar, Ravi; Koenig, Daniel; Kimura, Seisuke; Townsley, Brad; Runo, Steven; Garces, Helena M; Kang, Julie; Yanez, Andrea; David-Schwartz, Rakefet; Machuka, Jesse; Sinha, Neelima

    2012-07-01

    Infection of crop species by parasitic plants is a major agricultural hindrance resulting in substantial crop losses worldwide. Parasitic plants establish vascular connections with the host plant via structures termed haustoria, which allow acquisition of water and nutrients, often to the detriment of the infected host. Despite the agricultural impact of parasitic plants, the molecular and developmental processes by which host/parasitic interactions are established are not well understood. Here, we examine the development and subsequent establishment of haustorial connections by the parasite dodder (Cuscuta pentagona) on tobacco (Nicotiana tabacum) plants. Formation of haustoria in dodder is accompanied by upregulation of dodder KNOTTED-like homeobox transcription factors, including SHOOT MERISTEMLESS-like (STM). We demonstrate interspecific silencing of a STM gene in dodder driven by a vascular-specific promoter in transgenic host plants and find that this silencing disrupts dodder growth. The reduced efficacy of dodder infection on STM RNA interference transgenics results from defects in haustorial connection, development, and establishment. Identification of transgene-specific small RNAs in the parasite, coupled with reduced parasite fecundity and increased growth of the infected host, demonstrates the efficacy of interspecific small RNA-mediated silencing of parasite genes. This technology has the potential to be an effective method of biological control of plant parasite infection.

  7. Specific Silencing of L392V PSEN1 Mutant Allele by RNA Interference

    Directory of Open Access Journals (Sweden)

    Malgorzata Sierant

    2011-01-01

    Full Text Available RNA interference (RNAi technology provides a powerful molecular tool to reduce an expression of selected genes in eukaryotic cells. Short interfering RNAs (siRNAs are the effector molecules that trigger RNAi. Here, we describe siRNAs that discriminate between the wild type and mutant (1174 C→G alleles of human Presenilin1 gene (PSEN1. This mutation, resulting in L392V PSEN1 variant, contributes to early onset familial Alzheimer's disease. Using the dual fluorescence assay, flow cytometry and fluorescent microscopy we identified positions 8th–11th, within the central part of the antisense strand, as the most sensitive to mismatches. 2-Thiouridine chemical modification introduced at the 3′-end of the antisense strand improved the allele discrimination, but wobble base pairing adjacent to the mutation site abolished the siRNA activity. Our data indicate that siRNAs can be designed to discriminate between the wild type and mutant alleles of genes that differ by just a single nucleotide.

  8. Overexpression and RNA interference of TwDXR regulate the accumulation of terpenoid active ingredients in Tripterygium wilfordii.

    Science.gov (United States)

    Zhang, Yifeng; Zhao, Yujun; Wang, Jiadian; Hu, Tianyuan; Tong, Yuru; Zhou, Jiawei; Song, Yadi; Gao, Wei; Huang, Luqi

    2018-02-01

    To examine the putative regulatory role of TwDXR in terpenoid biosynthesis and terpenoid biosynthetic pathway-related gene expression, through overexpression and RNA interference with TwDXR. We obtained 1410 and 454 bp TwDXR-specific fragments to construct overexpression and RNAi vectors. qRT-PCR was used to detect the expression of TwDXR and terpenoid biosynthesis pathway-related genes. The overexpression of TwDXR led to a 285% upregulation and the TwDXR RNAi led to a reduction to 26% of the control (empty vector-transformed cells) levels. However, pathway-related genes displayed different trends. When TwDXR was overexpressed, TwDXS expression decreased by 31% but increased to 198% when TwDXR expression was inhibited. The accumulation of terpenoids was also assayed. In the overexpression group, differences were not significant whereas the contents of triptolide and celastrol in the TwDXR RNAi samples were diminished by 27.3 and 24.0%, respectively. The feedback regulation of gene transcription and the accumulation of terpenoids in terpenoid biosynthesis in Tripterygium wilfordii were verified by TwDXR overexpression and RNAi experiments.

  9. Normalization of Overexpressed α-Synuclein Causing Parkinson's Disease By a Moderate Gene Silencing With RNA Interference

    Directory of Open Access Journals (Sweden)

    Masaki Takahashi

    2015-01-01

    Full Text Available The α-synuclein (SNCA gene is a responsible gene for Parkinson's disease (PD; and not only nucleotide variations but also overexpression of SNCA appears to be involved in the pathogenesis of PD. A specific inhibition against mutant SNCA genes carrying nucleotide variations may be feasible by a specific silencing such as an allele-specific RNA interference (RNAi; however, there is no method for restoring the SNCA overexpression to a normal level. Here, we show that an atypical RNAi using small interfering RNAs (siRNAs that confer a moderate level of gene silencing is capable of controlling overexpressed SNCA genes to return to a normal level; named “expression-control RNAi” (ExCont-RNAi. ExCont-RNAi exhibited little or no significant off-target effects in its treated PD patient's fibroblasts that carry SNCA triplication. To further assess the therapeutic effect of ExCont-RNAi, PD-model flies that carried the human SNCA gene underwent an ExCont-RNAi treatment. The treated PD-flies demonstrated a significant improvement in their motor function. Our current findings suggested that ExCont-RNAi might be capable of becoming a novel therapeutic procedure for PD with the SNCA overexpression, and that siRNAs conferring a moderate level of gene silencing to target genes, which have been abandoned as useless siRNAs so far, might be available for controlling abnormally expressed disease-causing genes without producing adverse effects.

  10. RNA Interference Technology to Control Pest Sea Lampreys - A Proof-of-Concept

    Science.gov (United States)

    Heath, George; Childs, Darcy; Docker, Margaret F.; McCauley, David W.; Whyard, Steven

    2014-01-01

    The parasitic sea lamprey (Petromyzon marinus) has caused extensive losses to commercial fish stocks of the upper Great Lakes of North America. Methods of controlling the sea lamprey include trapping, barriers to prevent migration, and use of a chemical lampricide (3-trifluoromethyl-4-nitrophenol) to kill the filter-feeding larvae. Concerns about the non-specificity of these methods have prompted continued development of species-specific methods to control lampreys outside their native range. In this study, we considered the utility of RNA interference to develop a sea lamprey-specific lampricide. Injection of six different short interfering, double-stranded RNAs (siRNAs) into lamprey embryos first confirmed that the siRNAs could reduce the targeted transcript levels by more than 50%. Two size classes of lamprey larvae were then fed the siRNAs complexed with liposomes, and three of the siRNAs (targeting elongation factor 1α, calmodulin, and α-actinin) reduced transcript levels 2.5, 3.6, and 5.0–fold, respectively, within the lamprey midsections. This is not only the first demonstration of RNAi in lampreys, but it is also the first example of delivery of siRNAs to a non-mammalian vertebrate through feeding formulations. One of the siRNA treatments also caused increased mortality of the larvae following a single feeding of siRNAs, which suggests that prolonged or multiple feedings of siRNAs could be used to kill filter-feeding larvae within streams, following development of a slow-release formulation. The genes targeted in this study are highly conserved across many species, and only serve as a proof-of-concept demonstration that siRNAs can be used in lampreys. Given that RNA interference is a sequence-specific phenomenon, it should be possible to design siRNAs that selectively target gene sequences that are unique to sea lampreys, and thus develop a technology to control these pests without adversely affecting non-target species. PMID:24505485

  11. RNA interference technology to control pest sea lampreys--a proof-of-concept.

    Directory of Open Access Journals (Sweden)

    George Heath

    Full Text Available The parasitic sea lamprey (Petromyzon marinus has caused extensive losses to commercial fish stocks of the upper Great Lakes of North America. Methods of controlling the sea lamprey include trapping, barriers to prevent migration, and use of a chemical lampricide (3-trifluoromethyl-4-nitrophenol to kill the filter-feeding larvae. Concerns about the non-specificity of these methods have prompted continued development of species-specific methods to control lampreys outside their native range. In this study, we considered the utility of RNA interference to develop a sea lamprey-specific lampricide. Injection of six different short interfering, double-stranded RNAs (siRNAs into lamprey embryos first confirmed that the siRNAs could reduce the targeted transcript levels by more than 50%. Two size classes of lamprey larvae were then fed the siRNAs complexed with liposomes, and three of the siRNAs (targeting elongation factor 1α, calmodulin, and α-actinin reduced transcript levels 2.5, 3.6, and 5.0-fold, respectively, within the lamprey midsections. This is not only the first demonstration of RNAi in lampreys, but it is also the first example of delivery of siRNAs to a non-mammalian vertebrate through feeding formulations. One of the siRNA treatments also caused increased mortality of the larvae following a single feeding of siRNAs, which suggests that prolonged or multiple feedings of siRNAs could be used to kill filter-feeding larvae within streams, following development of a slow-release formulation. The genes targeted in this study are highly conserved across many species, and only serve as a proof-of-concept demonstration that siRNAs can be used in lampreys. Given that RNA interference is a sequence-specific phenomenon, it should be possible to design siRNAs that selectively target gene sequences that are unique to sea lampreys, and thus develop a technology to control these pests without adversely affecting non-target species.

  12. RNA interference technology to control pest sea lampreys--a proof-of-concept.

    Science.gov (United States)

    Heath, George; Childs, Darcy; Docker, Margaret F; McCauley, David W; Whyard, Steven

    2014-01-01

    The parasitic sea lamprey (Petromyzon marinus) has caused extensive losses to commercial fish stocks of the upper Great Lakes of North America. Methods of controlling the sea lamprey include trapping, barriers to prevent migration, and use of a chemical lampricide (3-trifluoromethyl-4-nitrophenol) to kill the filter-feeding larvae. Concerns about the non-specificity of these methods have prompted continued development of species-specific methods to control lampreys outside their native range. In this study, we considered the utility of RNA interference to develop a sea lamprey-specific lampricide. Injection of six different short interfering, double-stranded RNAs (siRNAs) into lamprey embryos first confirmed that the siRNAs could reduce the targeted transcript levels by more than 50%. Two size classes of lamprey larvae were then fed the siRNAs complexed with liposomes, and three of the siRNAs (targeting elongation factor 1α, calmodulin, and α-actinin) reduced transcript levels 2.5, 3.6, and 5.0-fold, respectively, within the lamprey midsections. This is not only the first demonstration of RNAi in lampreys, but it is also the first example of delivery of siRNAs to a non-mammalian vertebrate through feeding formulations. One of the siRNA treatments also caused increased mortality of the larvae following a single feeding of siRNAs, which suggests that prolonged or multiple feedings of siRNAs could be used to kill filter-feeding larvae within streams, following development of a slow-release formulation. The genes targeted in this study are highly conserved across many species, and only serve as a proof-of-concept demonstration that siRNAs can be used in lampreys. Given that RNA interference is a sequence-specific phenomenon, it should be possible to design siRNAs that selectively target gene sequences that are unique to sea lampreys, and thus develop a technology to control these pests without adversely affecting non-target species.

  13. Small Interference RNA Targeting TLR4 Gene Effectively Attenuates Pulmonary Inflammation in a Rat Model

    Directory of Open Access Journals (Sweden)

    Feixiang Wu

    2012-01-01

    Full Text Available Objective. The present study was to investigate the feasibility of adenovirus-mediated small interference RNA (siRNA targeting Toll-like receptor 4 (TLR4 gene in ameliorating lipopolysaccharide- (LPS- induced acute lung injury (ALI. Methods. In vitro, alveolar macrophages (AMs were treated with Ad-siTLR4 and Ad-EFGP, respectively, for 12 h, 24 h, and 48 h, and then with LPS (100 ng/mL for 2 h, and the function and expression of TLR4 were evaluated. In vivo, rats received intratracheal injection of 300 μL of normal saline (control group, 300 μL of Ad-EGFP (Ad-EGFP group, or 300 μL of Ad-siTLR4 (Ad-siTLR4 group and then were intravenously treated with LPS (50 mg/kg to induce ALI. Results. Ad-siTLR4 treatment significantly reduced TLR4 expression and production of proinflammatory cytokines following LPS treatment both in vitro and in vivo. Significant alleviation of tissue edema, microvascular protein leakage, and neutrophil infiltration was observed in the AdsiTLR4-treated animals. Conclusion. TLR4 plays a critical role in LPS-induced ALI, and transfection of Ad-siTLR4 can effectively downregulate TLR4 expression in vitro and in vivo, accompanied by alleviation of LPS-induced lung injury. These findings suggest that TLR4 may serve as a potential target in the treatment of ALI and RNA interfering targeting TLR4 expression represents a therapeutic strategy.

  14. Targeting the epidermal growth factor receptor in non-small cell lung cancer cells: the effect of combining RNA interference with tyrosine kinase inhibitors or cetuximab

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    Chen Gang

    2012-03-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR is a validated therapeutic target in non-small cell lung cancer (NSCLC. However, current single agent receptor targeting does not achieve a maximal therapeutic effect, and some mutations confer resistance to current available agents. In the current study we have examined, in different NSCLC cell lines, the combined effect of RNA interference targeting the EGFR mRNA, and inactivation of EGFR signaling using different receptor tyrosine kinase inhibitors (TKIs or a monoclonal antibody cetuximab. Methods NSCLC cells (cell lines HCC827, H292, H358, H1650, and H1975 were transfected with EGFR siRNA and/or treated with the TKIs gefitinib, erlotinib, and afatinib, and/or with the monoclonal antibody cetuximab. The reduction of EGFR mRNA expression was measured by real-time quantitative RT-PCR. The down-regulation of EGFR protein expression was measured by western blot, and the proliferation, viability, caspase3/7 activity, and apoptotic morphology were monitored by spectrophotometry, fluorimetry, and fluorescence microscopy. The combined effect of EGFR siRNA and different drugs was evaluated using a combination index. Results EGFR-specific siRNA strongly inhibited EGFR protein expression almost equally in all cell lines and inhibited cell growth and induced cell apoptosis in all NSCLC cell lines studied, albeit with a different magnitude. The effects on growth obtained with siRNA was strikingly different from the effects obtained with TKIs. The effects of siRNA probably correlate with the overall oncogenic significance of the receptor, which is only partly inhibited by the TKIs. The cells which showed weak response to TKIs, such as the H1975 cell line containing the T790M resistance mutation, were found to be responsive to siRNA knockdown of EGFR, as were cell lines with downstream TKI resistance mutations. The cell line HCC827, harboring an exon 19 deletion mutation, was more than 10-fold

  15. Global effects of the CSR-1 RNA interference pathway on transcriptional landscape

    Science.gov (United States)

    Cecere, Germano; Hoersch, Sebastian; O’Keeffe, Sean; Sachidanandam, Ravi; Grishok, Alla

    2014-01-01

    Argonaute proteins and their small RNA co-factors short interfering RNAs (siRNAs) are known to inhibit gene expression at the transcriptional and post-transcriptional levels. In Caenorhabditis elegans, the Argonaute CSR-1 binds thousands of endogenous siRNAs (endo-siRNAs) antisense to germline transcripts and associates with chromatin in a siRNA-dependent manner. However, its role in gene expression regulation remains controversial. Here, we used a genome-wide profiling of nascent RNA transcripts to demonstrate that the CSR-1 RNAi pathway promotes sense-oriented Pol II transcription. Moreover, a loss of CSR-1 function resulted in global increase in antisense transcription and ectopic transcription of silent chromatin domains, which led to reduced chromatin incorporation of centromere-specific histone H3. Based on these findings, we propose that the CSR-1 pathway has a role in maintaining the directionality of active transcription thereby propagating the distinction between transcriptionally active and silent genomic regions. PMID:24681887

  16. RNA Interference Based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly

    Science.gov (United States)

    Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) could offer potential for insect pest management. Insects feeding exclusively on plant sap depend on osmotic pressure...

  17. Nuclear Factor 90, a cellular dsRNA binding protein inhibits the HIV Rev-export function

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    St-Laurent Georges

    2006-11-01

    Full Text Available Abstract Background The HIV Rev protein is known to facilitate export of incompletely spliced and unspliced viral transcripts to the cytoplasm, a necessary step in virus life cycle. The Rev-mediated nucleo-cytoplasmic transport of nascent viral transcripts, dependents on interaction of Rev with the RRE RNA structural element present in the target RNAs. The C-terminal variant of dsRNA-binding nuclear protein 90 (NF90ctv has been shown to markedly attenuate viral replication in stably transduced HIV-1 target cell line. Here we examined a mechanism of interference of viral life cycle involving Rev-NF90ctv interaction. Results Since Rev:RRE complex formations depend on protein:RNA and protein:protein interactions, we investigated whether the expression of NF90ctv might interfere with Rev-mediated export of RRE-containing transcripts. When HeLa cells expressed both NF90ctv and Rev protein, we observed that NF90ctv inhibited the Rev-mediated RNA transport. In particular, three regions of NF90ctv protein are involved in blocking Rev function. Moreover, interaction of NF90ctv with the RRE RNA resulted in the expression of a reporter protein coding sequences linked to the RRE structure. Moreover, Rev influenced the subcellular localization of NF90ctv, and this process is leptomycin B sensitive. Conclusion The dsRNA binding protein, NF90ctv competes with HIV Rev function at two levels, by competitive protein:protein interaction involving Rev binding to specific domains of NF90ctv, as well as by its binding to the RRE-RNA structure. Our results are consistent with a model of Rev-mediated HIV-1 RNA export that envisions Rev-multimerization, a process interrupted by NF90ctv.

  18. Downregulation of mouse CCR3 by lentiviral shRNA inhibits proliferation and induces apoptosis of mouse eosinophils.

    Science.gov (United States)

    Zhu, Xin-Hua; Liao, Bing; Xu, Yi; Liu, Ke; Huang, Yun; Huang, Quan-Long; Liu, Yue-Hui

    2017-02-01

    RNA interference has been considered as an effective gene silencing method in basic and preclinical investigations. The aims of the present study were to construct a lentiviral vector expressing a short hairpin RNA (shRNA) targeting the murine CC chemokine receptor 3 (mCCR3), and to investigate its effects on the proliferation and apoptosis of mouse eosinophils. A recombinant lentiviral vector expressing four fragments of mouse CCR3 shRNA (pLVX‑mCCR3‑1+2+3+4‑shRNA) was constructed using subcloning techniques. This novel lentivirus was then packaged into 293T cells by co‑transduction with plasmids, including Baculo p35, pCMV R8.2 and VSV. The interference effects of the vector were verified using polymerase chain reaction (PCR) and western blot analyses. The effects of the interference on the proliferation and apoptosis of mouse eosinophils were investigated using 3‑(4,5‑dimethylthiazol‑2‑yl)‑5‑(3‑carboxymethoxyphenyl)‑2‑(4‑sulfophenyl)‑2H‑tetrazolium and terminal deoxynucleotidyl transferase dUTP nick end labeling methods, respectively. The results of the PCR and western blot analyses confirmed that the novel recombinant vector, pLVX‑mCCR3‑1+2+3+4‑shRNA, had high efficiency in inhibiting the mRNA and protein expression levels of mCCR3 in mouse eosinophils. The downregulation of mCCR3 significantly inhibited proliferation of the eosinophils. Furthermore, the present study found that the downregulation of mCCR3 significantly promoted apoptosis of the eosinophils. Therefore, the downregulation of mCCR3 led to the inhibition of proliferation and induction of apoptosis in mouse eosinophils. The predominant characteristics of allergic rhinitis are eosinophil infiltration and release of inflammatory mediators, which appear in a variety of clinical manifestations. The results of the present study indicate that mCCR3 silencing may serve as a putative approach for the treatment of allergic rhinitis.

  19. Fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of LncRNA MEG3

    International Nuclear Information System (INIS)

    Hu, Duanmin; Su, Cunjin; Jiang, Min; Shen, Yating; Shi, Aiming; Zhao, Fenglun; Chen, Ruidong; Shen, Zhu; Bao, Junjie; Tang, Wen

    2016-01-01

    There is still no suitable drug for pancreatic cancer treatment, which is one of the most aggressive human tumors. Maternally expressed gene 3 (MEG3), a LncRNA, has been suggested as a tumor suppressor in a range of human tumors. Studies found fenofibrate exerted anti-tumor roles in various human cancer cell lines. However, its role in pancreatic cancer remains unknown. The present study aimed to explore the impacts of fenofibrate on pancreatic cancer cell lines, and to investigate MEG3 role in its anti-tumor mechanisms. We used MTT assay to determine cells proliferation, genome-wide LncRNA microarray analysis to identify differently expressed LncRNAs, siRNA or pCDNA-MEG3 transfection to interfere or upregulate MEG3 expression, western blot to detect protein levels, real-time PCR to determine MEG3 level. Fenofibrate significantly inhibited proliferation of pancreatic cancer cells, increased MEG3 expression and p53 levels. Moreover, knockdown of MEG3 attenuated cytotoxicity induced by fenofibrate. Furthermore, overexpression of MEG3 induced cells death and increased p53 expression. Our results indicated fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of MEG3. - Highlights: • We found that fenofibrate suppressed proliferation of pancreatic cancer cells. • We found fenofibrate increased LncRNA-MEG3 expression and p53 level in PANC-1 cells. • Inhibition of MEG3 expression attenuated anti-tumor effects of fenofibrate.

  20. Fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of LncRNA MEG3

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Duanmin [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Su, Cunjin [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Jiang, Min [Department of Breast Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shen, Yating [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shi, Aiming; Zhao, Fenglun [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Chen, Ruidong [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Shen, Zhu [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Bao, Junjie, E-mail: baojjsdfey@sina.com [Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China); Tang, Wen, E-mail: sztangwen@163.com [Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, Suzhou 215004 (China)

    2016-03-04

    There is still no suitable drug for pancreatic cancer treatment, which is one of the most aggressive human tumors. Maternally expressed gene 3 (MEG3), a LncRNA, has been suggested as a tumor suppressor in a range of human tumors. Studies found fenofibrate exerted anti-tumor roles in various human cancer cell lines. However, its role in pancreatic cancer remains unknown. The present study aimed to explore the impacts of fenofibrate on pancreatic cancer cell lines, and to investigate MEG3 role in its anti-tumor mechanisms. We used MTT assay to determine cells proliferation, genome-wide LncRNA microarray analysis to identify differently expressed LncRNAs, siRNA or pCDNA-MEG3 transfection to interfere or upregulate MEG3 expression, western blot to detect protein levels, real-time PCR to determine MEG3 level. Fenofibrate significantly inhibited proliferation of pancreatic cancer cells, increased MEG3 expression and p53 levels. Moreover, knockdown of MEG3 attenuated cytotoxicity induced by fenofibrate. Furthermore, overexpression of MEG3 induced cells death and increased p53 expression. Our results indicated fenofibrate inhibited pancreatic cancer cells proliferation via activation of p53 mediated by upregulation of MEG3. - Highlights: • We found that fenofibrate suppressed proliferation of pancreatic cancer cells. • We found fenofibrate increased LncRNA-MEG3 expression and p53 level in PANC-1 cells. • Inhibition of MEG3 expression attenuated anti-tumor effects of fenofibrate.

  1. Silencing of RhoA and RhoC expression by RNA interference suppresses human colorectal carcinoma growth in vivo

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    Wang Haibo

    2010-09-01

    Full Text Available Abstract Background RhoA and RhoC have been proved to be over-expressed in many solid cancers, including colorectal cancer. The reduction of RhoA and RhoC expression by RNA interference (RNAi resulted growth inhibition of cancer cells. The present study was to evaluate the effect of silencing of RhoA and RhoC expression by RNAi on growth of human colorectal carcinoma (CRC in tumor-bearing nude mice in vivo. Methods To establish HCT116 cell transplantable model, the nude mice were subcutaneously inoculated with 1.0 × 107 HCT116 cells and kept growing till the tumor xenografts reached 5-7 mm in diameter. Then the mice were randomly assigned to three groups(seven mice in each group: (1 normal saline(NS group, (2replication-defective recombinant adenovirus carrying the negative control shRNA (Ad-HK group and (3replication-defective recombinant adenovirus carrying the 4-tandem linked RhoA and RhoC shRNAs (Ad-RhoA-RhoC group. Ad-HK (4 × 108 pfu, 30 ul/mouse, Ad-RhoA-RhoC (4 × 108 pfu, 30 ul/mouse or PBS (30 ul/mouse was injected intratumorally four times once every other day. The weight and volumes of tumor xenografts were recorded. The levels of RhoA and RhoC mRNA transcripts and proteins in tumor xenografts were detected by reverse quantitative transcription polymerase chain reaction (QRT-PCR and immunohistochemical staining respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL assay was used to detect the death of cells. Results The xenografts in mice could be seen at 5th day from the implantation of HCT116 cells and all had reached 5-7 mm in size at 9th day. After injection intratumorally, the growth speed of tumor xenografts in Ad-RhoA-RhoC group was significantly delayed compared with those in NS and Ad-HK group(P RhoA and RhoC reduced more in Ad-RhoA-RhoC group than those in NS and Ad-HK group. The relative RhoA and RhoC mRNA transcripts were decreased to 48% and 43% respectively (P RhoA and Rho

  2. Transcriptome analysis in cotton boll weevil (Anthonomus grandis and RNA interference in insect pests.

    Directory of Open Access Journals (Sweden)

    Alexandre Augusto Pereira Firmino

    Full Text Available Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

  3. Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.

    Science.gov (United States)

    Firmino, Alexandre Augusto Pereira; Fonseca, Fernando Campos de Assis; de Macedo, Leonardo Lima Pepino; Coelho, Roberta Ramos; Antonino de Souza, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

    2013-01-01

    Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

  4. Different functions of the insect soluble and membrane-bound trehalase genes in chitin biosynthesis revealed by RNA interference.

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    Jie Chen

    Full Text Available BACKGROUND: Trehalase, an enzyme that hydrolyzes trehalose to yield two glucose molecules, plays a pivotal role in various physiological processes. In recent years, trehalase proteins have been purified from several insect species and are divided into soluble (Tre-1 and membrane-bound (Tre-2 trehalases. However, no functions of the two trehalases in chitin biosynthesis in insects have yet been reported. PRINCIPAL FINDINGS: The membrane-bound trehalase of Spodoptera exigua (SeTre-2 was characterized in our laboratory previously. In this study, we cloned the soluble trehalase gene (SeTre-1 and investigated the tissue distribution and developmental expression pattern of the two trehalase genes. SeTre-1 was expressed highly in cuticle and Malpighian tubules, while SeTre-2 was expressed in tracheae and fat body. In the midgut, the two trehalase genes were expressed in different locations. Additionally, the expression profiles of both trehalase mRNAs and their enzyme activities suggest that they may play different roles in chitin biosynthesis. The RNA interference (RNAi of either SeTre-1 or SeTre-2 was gene-specific and effective, with efficiency rates up to 83% at 72 h post injection. After RNAi of SeTre-1 and SeTre-2, significant higher mortality rates were observed during the larva-pupa stage and pupa-adult stage, and the lethal phenotypes were classified and analyzed. Additionally, the change trends of concentration of trehalose and glucose appeared reciprocally in RNAi-mutants. Moreover, knockdown of SeTre-1 gene largely inhibited the expression of chitin synthase gene A (CHSA and reduced the chitin content in the cuticle to two-thirds relative to the control insects. The chitin synthase gene B (CHSB expression, however, was inhibited more by the injection of dsRNA for SeTre-2, and the chitin content in the midgut decreased by about 25%. CONCLUSIONS: SeTre-1 plays a major role in CHSA expression and chitin synthesis in the cuticle, and SeTre-2

  5. Inhibition of hepatitis B virus replication with linear DNA sequences expressing antiviral micro-RNA shuttles

    International Nuclear Information System (INIS)

    Chattopadhyay, Saket; Ely, Abdullah; Bloom, Kristie; Weinberg, Marc S.; Arbuthnot, Patrick

    2009-01-01

    RNA interference (RNAi) may be harnessed to inhibit viral gene expression and this approach is being developed to counter chronic infection with hepatitis B virus (HBV). Compared to synthetic RNAi activators, DNA expression cassettes that generate silencing sequences have advantages of sustained efficacy and ease of propagation in plasmid DNA (pDNA). However, the large size of pDNAs and inclusion of sequences conferring antibiotic resistance and immunostimulation limit delivery efficiency and safety. To develop use of alternative DNA templates that may be applied for therapeutic gene silencing, we assessed the usefulness of PCR-generated linear expression cassettes that produce anti-HBV micro-RNA (miR) shuttles. We found that silencing of HBV markers of replication was efficient (>75%) in cell culture and in vivo. miR shuttles were processed to form anti-HBV guide strands and there was no evidence of induction of the interferon response. Modification of terminal sequences to include flanking human adenoviral type-5 inverted terminal repeats was easily achieved and did not compromise silencing efficacy. These linear DNA sequences should have utility in the development of gene silencing applications where modifications of terminal elements with elimination of potentially harmful and non-essential sequences are required.

  6. Inhibition of hepatitis B virus replication with linear DNA sequences expressing antiviral micro-RNA shuttles

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, Saket; Ely, Abdullah; Bloom, Kristie; Weinberg, Marc S. [Antiviral Gene Therapy Research Unit, University of the Witwatersrand (South Africa); Arbuthnot, Patrick, E-mail: Patrick.Arbuthnot@wits.ac.za [Antiviral Gene Therapy Research Unit, University of the Witwatersrand (South Africa)

    2009-11-20

    RNA interference (RNAi) may be harnessed to inhibit viral gene expression and this approach is being developed to counter chronic infection with hepatitis B virus (HBV). Compared to synthetic RNAi activators, DNA expression cassettes that generate silencing sequences have advantages of sustained efficacy and ease of propagation in plasmid DNA (pDNA). However, the large size of pDNAs and inclusion of sequences conferring antibiotic resistance and immunostimulation limit delivery efficiency and safety. To develop use of alternative DNA templates that may be applied for therapeutic gene silencing, we assessed the usefulness of PCR-generated linear expression cassettes that produce anti-HBV micro-RNA (miR) shuttles. We found that silencing of HBV markers of replication was efficient (>75%) in cell culture and in vivo. miR shuttles were processed to form anti-HBV guide strands and there was no evidence of induction of the interferon response. Modification of terminal sequences to include flanking human adenoviral type-5 inverted terminal repeats was easily achieved and did not compromise silencing efficacy. These linear DNA sequences should have utility in the development of gene silencing applications where modifications of terminal elements with elimination of potentially harmful and non-essential sequences are required.

  7. Assessing Specific Oligonucleotides and Small Molecule Antibiotics for the Ability to Inhibit the CRD-BP-CD44 RNA Interaction

    Science.gov (United States)

    Thomsen, Dana; Lee, Chow H.

    2014-01-01

    Studies on Coding Region Determinant-Binding Protein (CRD-BP) and its orthologs have confirmed their functional role in mRNA stability and localization. CRD-BP is present in extremely low levels in normal adult tissues, but it is over-expressed in many types of aggressive human cancers and in neonatal tissues. Although the exact role of CRD-BP in tumour progression is unclear, cumulative evidence suggests that its ability to physically associate with target mRNAs is an important criterion for its oncogenic role. CRD-BP has high affinity for the 3′UTR of the oncogenic CD44 mRNA and depletion of CRD-BP in cells led to destabilization of CD44 mRNA, decreased CD44 expression, reduced adhesion and disruption of invadopodia formation. Here, we further characterize the CRD-BP-CD44 RNA interaction and assess specific antisense oligonucleotides and small molecule antibiotics for their ability to inhibit the CRD-BP-CD44 RNA interaction. CRD-BP has a high affinity for binding to CD44 RNA nts 2862–3055 with a Kd of 645 nM. Out of ten antisense oligonucleotides spanning nts 2862–3055, only three antisense oligonucleotides (DD4, DD7 and DD10) were effective in competing with CRD-BP for binding to 32P-labeled CD44 RNA. The potency of DD4, DD7 and DD10 in inhibiting the CRD-BP-CD44 RNA interaction in vitro correlated with their ability to specifically reduce the steady-state level of CD44 mRNA in cells. The aminoglycoside antibiotics neomycin, paramomycin, kanamycin and streptomycin effectively inhibited the CRD-BP-CD44 RNA interaction in vitro. Assessing the potential inhibitory effect of aminoglycoside antibiotics including neomycin on the CRD-BP-CD44 mRNA interaction in cells proved difficult, likely due to their propensity to non-specifically bind nucleic acids. Our results have important implications for future studies in finding small molecules and nucleic acid-based inhibitors that interfere with protein-RNA interactions. PMID:24622399

  8. Loss of wobble uridine modification in tRNA anticodons interferes with TOR pathway signaling

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    Viktor Scheidt

    2014-11-01

    Full Text Available Previous work in yeast has suggested that modification of tRNAs, in particular uridine bases in the anticodon wobble position (U34, is linked to TOR (target of rapamycin signaling. Hence, U34 modification mutants were found to be hypersensitive to TOR inhibition by rapamycin. To study whether this involves inappropriate TOR signaling, we examined interaction between mutations in TOR pathway genes (tip41∆, sap190∆, ppm1∆, rrd1∆ and U34 modification defects (elp3∆, kti12∆, urm1∆, ncs2∆ and found the rapamycin hypersensitivity in the latter is epistatic to drug resistance of the former. Epistasis, however, is abolished in tandem with a gln3∆ deletion, which inactivates transcription factor Gln3 required for TOR-sensitive activation of NCR (nitrogen catabolite repression genes. In line with nuclear import of Gln3 being under control of TOR and dephosphorylation by the Sit4 phosphatase, we identify novel TOR-sensitive sit4 mutations that confer rapamycin resistance and importantly, mislocalise Gln3 when TOR is inhibited. This is similar to gln3∆ cells, which abolish the rapamycin hypersensitivity of U34 modification mutants, and suggests TOR deregulation due to tRNA undermodification operates through Gln3. In line with this, loss of U34 modifications (elp3∆, urm1∆ enhances nuclear import of and NCR gene activation (MEP2, GAP1 by Gln3 when TOR activity is low. Strikingly, this stimulatory effect onto Gln3 is suppressed by overexpression of tRNAs that usually carry the U34 modifications. Collectively, our data suggest that proper TOR signaling requires intact tRNA modifications and that loss of U34 modifications impinges on the TOR-sensitive NCR branch via Gln3 misregulation.

  9. Loss of wobble uridine modification in tRNA anticodons interferes with TOR pathway signaling.

    Science.gov (United States)

    Scheidt, Viktor; Jüdes, André; Bär, Christian; Klassen, Roland; Schaffrath, Raffael

    2014-11-29

    Previous work in yeast has suggested that modification of tRNAs, in particular uridine bases in the anticodon wobble position (U34), is linked to TOR (target of rapamycin) signaling. Hence, U34 modification mutants were found to be hypersensitive to TOR inhibition by rapamycin. To study whether this involves inappropriate TOR signaling, we examined interaction between mutations in TOR pathway genes ( tip41 ∆, sap190 ∆, ppm1 ∆, rrd1 ∆) and U34 modification defects ( elp3 ∆, kti 12∆, urm1 ∆, ncs2 ∆) and found the rapamycin hypersensitivity in the latter is epistatic to drug resistance of the former. Epistasis, however, is abolished in tandem with a gln3 ∆ deletion, which inactivates transcription factor Gln3 required for TOR-sensitive activation of NCR (nitrogen catabolite repression) genes. In line with nuclear import of Gln3 being under control of TOR and dephosphorylation by the Sit4 phosphatase, we identify novel TOR-sensitive sit4 mutations that confer rapamycin resistance and importantly, mislocalise Gln3 when TOR is inhibited. This is similar to gln3 ∆ cells, which abolish the rapamycin hypersensitivity of U34 modification mutants, and suggests TOR deregulation due to tRNA undermodification operates through Gln3. In line with this, loss of U34 modifications ( elp3 ∆, urm1 ∆) enhances nuclear import of and NCR gene activation ( MEP2 , GAP1 ) by Gln3 when TOR activity is low. Strikingly, this stimulatory effect onto Gln3 is suppressed by overexpression of tRNAs that usually carry the U34 modifications. Collectively, our data suggest that proper TOR signaling requires intact tRNA modifications and that loss of U34 modifications impinges on the TOR-sensitive NCR branch via Gln3 misregulation.

  10. Knockdown of E2f1 by RNA interference impairs proliferation of rat cells in vitro

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    Luciana dos Reis Vasques

    2010-01-01

    Full Text Available E2F1 plays a key role in cell-cycle regulation in mammals, since its transcription factor activity controls genes required for DNA synthesis and apoptosis. E2F1 deregulation is a common feature among different tumor types and can be a major cause of cell proliferation. Thus, blocking E2F1 expression by RNA interference represents a promising therapeutic approach. In this study, the introduction of specific short hairpin RNAs (shRNAs reduced E2f1 expression by up to 77%, and impaired rat glioma cell proliferation by approximately 70%, as compared to control cells. Furthermore, we investigated the expression of E2f1 target genes, Cyclin A and Cyclin E. Cyclin A was found to be down-regulated, whereas Cyclin E had similar expression to control cells, indicating that gene(s other than E2f1 control its transcription. Other E2f family members, E2f2 and E2f3, which have been classified in the same subgroup of transcriptional activators, were also analyzed. Expression of both E2f2 and E2f3 was similar to control cells, showing no cross-inactivation or up-regulation to compensate for the absence of E2f1. Nevertheless, their expression was insufficient to maintain the initial proliferation potential. Taken together, our results suggest that shE2f1 is a promising therapy to control tumor cell proliferation.

  11. RNA interference: Applications and advances in insect toxicology and insect pest management.

    Science.gov (United States)

    Kim, Young Ho; Soumaila Issa, Moustapha; Cooper, Anastasia M W; Zhu, Kun Yan

    2015-05-01

    Since its discovery, RNA interference (RNAi) has revolutionized functional genomic studies due to its sequence-specific nature of post-transcriptional gene silencing. In this paper, we provide a comprehensive review of the recent literature and summarize the current knowledge and advances in the applications of RNAi technologies in the field of insect toxicology and insect pest management. Many recent studies have focused on identification and validation of the genes encoding insecticide target proteins, such as acetylcholinesterases, ion channels, Bacillus thuringiensis receptors, and other receptors in the nervous system. RNAi technologies have also been widely applied to reveal the role of genes encoding cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases in insecticide detoxification and resistance. More recently, studies have focused on understanding the mechanism of insecticide-mediated up-regulation of detoxification genes in insects. As RNAi has already shown great potentials for insect pest management, many recent studies have also focused on host-induced gene silencing, in which several RNAi-based transgenic plants have been developed and tested as proof of concept for insect pest management. These studies indicate that RNAi is a valuable tool to address various fundamental questions in insect toxicology and may soon become an effective strategy for insect pest management. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Phenotypic changes associated with RNA interference silencing of chalcone synthase in apple (Malus × domestica).

    Science.gov (United States)

    Dare, Andrew P; Tomes, Sumathi; Jones, Midori; McGhie, Tony K; Stevenson, David E; Johnson, Ross A; Greenwood, David R; Hellens, Roger P

    2013-05-01

    We have identified in apple (Malus × domestica) three chalcone synthase (CHS) genes. In order to understand the functional redundancy of this gene family RNA interference knockout lines were generated where all three of these genes were down-regulated. These lines had no detectable anthocyanins and radically reduced concentrations of dihydrochalcones and flavonoids. Surprisingly, down-regulation of CHS also led to major changes in plant development, resulting in plants with shortened internode lengths, smaller leaves and a greatly reduced growth rate. Microscopic analysis revealed that these phenotypic changes extended down to the cellular level, with CHS-silenced lines showing aberrant cellular organisation in the leaves. Fruit collected from one CHS-silenced line was smaller than the 'Royal Gala' controls, lacked flavonoids in the skin and flesh and also had changes in cell morphology. Auxin transport experiments showed increased rates of auxin transport in a CHS-silenced line compared with the 'Royal Gala' control. As flavonoids are well known to be key modulators of auxin transport, we hypothesise that the removal of almost all flavonoids from the plant by CHS silencing creates a vastly altered environment for auxin transport to occur and results in the observed changes in growth and development. © 2013 The Authors The Plant Journal © 2013 Blackwell Publishing Ltd.

  13. Host Recognition Responses of Western (Family: Chrysomelidae) Corn Rootworm Larvae to RNA Interference and Bt Corn.

    Science.gov (United States)

    Zukoff, Sarah N; Zukoff, Anthony L

    2017-01-01

    Western corn rootworm Diabrotica virgifera virgifera LeConte is an important pest of corn whose larvae exhibit particular quantifiable patterns of locomotion after exposure to, and removal from, host roots and nonhost roots. Using EthoVision software, the behavior and locomotion of the western corn rootworm larvae was analyzed to determine the level of host recognition to germinated roots of differing corn hybrids containing either rootworm targeted Bt genes, RNA interference (RNAi) technology, the stack of both Bt and RNAi, or the isoline of these. The behavior of the rootworm larvae indicated a significant host preference response to all corn hybrids (with or without insecticidal traits) compared to the filter paper and oat roots. A weaker host response to the RNAi corn roots was observed in the susceptible larvae when compared to the resistant larvae, but not for the Bt + RNAi vector stack. Additionally, the resistant larvae demonstrated a weaker host response to the isoline corn roots when compared to the susceptible larvae. Although weaker, these host responses were significantly different from those observed in the negative controls, indicating that all hybrids tested do contain the contact cues necessary to elicit a host preference response by both Cry3Bb1-resistant and Cry3Bb1-susceptible larvae that would work to hinder resistance development in refuge in a bag fields. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  14. Increased keratinocyte proliferation initiated through downregulation of desmoplakin by RNA interference

    International Nuclear Information System (INIS)

    Wan Hong; South, Andrew P.; Hart, Ian R.

    2007-01-01

    The intercellular adhesive junction desmosomes are essential for the maintenance of tissue structure and integrity in skin. Desmoplakin (Dp) is a major obligate plaque protein which plays a fundamental role in anchoring intermediate filaments to desmosomal cadherins. Evidence from hereditary human disease caused by mutations in the gene encoding Dp, e.g. Dp haploinsufficiency, suggests that alterations in Dp expression result not only in the disruption of tissue structure and integrity but also could evoke changes in keratinocyte proliferation. We have used transient RNA interference (RNAi) to downregulate Dp specifically in HaCaT keratinocytes. We showed that this Dp downregulation also caused reduced expression of several other desmosomal proteins. Increased cell proliferation and enhanced G 1 -to-S-phase entry in the cell cycle, as monitored by colonial cellular density and BrdU incorporation, were seen in Dp RNAi-treated cells. These proliferative changes were associated with elevated phospho-ERK1/2 and phospho-Akt levels. Furthermore, this increase in phospho-ERK/1/2 and phospho-Akt levels was sustained in Dp RNAi-treated cells at confluence whereas in control cells there was a significant reduction in phosphorylation of ERK1/2. This study indicates that Dp may participate in the regulation of keratinocyte cell proliferation by, in part at least, regulating cell cycle progression

  15. Understanding the core of RNA interference: The dynamic aspects of Argonaute-mediated processes

    KAUST Repository

    Zhu, Lizhe

    2016-10-05

    At the core of RNA interference, the Argonaute proteins (Ago) load and utilize small guide nucleic acids to silence mRNAs or cleave foreign nucleic acids in a sequence specific manner. In recent years, based on extensive structural studies of Ago and its interaction with the nucleic acids, considerable progress has been made to reveal the dynamic aspects of various Ago-mediated processes. Here we review these novel insights into the guide-strand loading, duplex unwinding, and effects of seed mismatch, with a focus on two representative Agos, the human Ago 2 (hAgo2) and the bacterial Thermus thermophilus Ago (TtAgo). In particular, comprehensive molecular simulation studies revealed that although sharing similar overall structures, the two Agos have vastly different conformational landscapes and guide-strand loading mechanisms because of the distinct rigidity of their L1-PAZ hinge. Given the central role of the PAZ motions in regulating the exposure of the nucleic acid binding channel, these findings exemplify the importance of protein motions in distinguishing the overlapping, yet distinct, mechanisms of Ago-mediated processes in different organisms.

  16. RNA interference-based therapeutics: new strategies to fight infectious disease.

    Science.gov (United States)

    López-Fraga, M; Wright, N; Jiménez, A

    2008-12-01

    For many years, there has been an ongoing search for new compounds that can selectively alter gene expression as a new way to treat human disease by addressing targets that are otherwise "undruggable" with traditional pharmaceutical approaches involving small molecules or proteins. RNA interference (RNAi) strategies have raised a lot of attention and several compounds are currently being tested in clinical trials. Viruses are the obvious target for RNAi-therapy, as most are difficult to treat with conventional drugs, they become rapidly resistant to drug treatment and their genes differ substantially from human genes, minimizing side effects. Antisense strategy offers very high target specificity, i.e., any viral sequence could potentially be targeted using the complementary oligonucleotide sequence. Consequently, new antisense-based therapeutics have the potential to lead a revolution in the anti-infective drug development field. Additionally, the relatively short turnaround for efficacy testing of potential RNAi molecules and that any pathogen is theoretically amenable to rapid targeting, make them invaluable tools for treating a wide range of diseases. This review will focus on some of the current efforts to treat infectious disease with RNAi-based therapies and some of the obstacles that have appeared on the road to successful clinical intervention.

  17. RNA-Interference Components Are Dispensable for Transcriptional Silencing of the Drosophila Bithorax-Complex

    KAUST Repository

    Cernilogar, Filippo M.

    2013-06-13

    Background:Beyond their role in post-transcriptional gene silencing, Dicer and Argonaute, two components of the RNA interference (RNAi) machinery, were shown to be involved in epigenetic regulation of centromeric heterochromatin and transcriptional gene silencing. In particular, RNAi mechanisms appear to play a role in repeat induced silencing and some aspects of Polycomb-mediated gene silencing. However, the functional interplay of RNAi mechanisms and Polycomb group (PcG) pathways at endogenous loci remains to be elucidated.Principal Findings:Here we show that the endogenous Dicer-2/Argonaute-2 RNAi pathway is dispensable for the PcG mediated silencing of the homeotic Bithorax Complex (BX-C). Although Dicer-2 depletion triggers mild transcriptional activation at Polycomb Response Elements (PREs), this does not induce transcriptional changes at PcG-repressed genes. Moreover, Dicer-2 is not needed to maintain global levels of methylation of lysine 27 of histone H3 and does not affect PRE-mediated higher order chromatin structures within the BX-C. Finally bioinformatic analysis, comparing published data sets of PcG targets with Argonaute-2-bound small RNAs reveals no enrichment of these small RNAs at promoter regions associated with PcG proteins.Conclusions:We conclude that the Dicer-2/Argonaute-2 RNAi pathway, despite its role in pairing sensitive gene silencing of transgenes, does not have a role in PcG dependent silencing of major homeotic gene cluster loci in Drosophila. © 2013 Cernilogar et al.

  18. RNA interference-based therapeutics for human immunodeficiency virus HIV-1 treatment: synthetic siRNA or vector-based shRNA?

    Science.gov (United States)

    Subramanya, Sandesh; Kim, Sang-Soo; Manjunath, N; Shankar, Premlata

    2010-02-01

    Despite the clinical benefits of highly active antiretroviral therapy (HAART), the prospect of life-long antiretroviral treatment poses significant problems, which has spurred interest in developing new drugs and strategies to treat HIV infection and eliminate persistent viral reservoirs. RNAi has emerged as a therapeutic possibility for HIV. We discuss progress in overcoming hurdles to translating transient and stable RNAi enabling technologies to clinical application for HIV; covering the past 2 - 3 years. HIV inhibition can be achieved by transfection of chemically or enzymatically synthesized siRNAs or by DNA-based vector systems expressing short hairpin RNAs (shRNAs) that are processed intracellularly into siRNA. We compare these approaches, focusing on technical and safety issues that will guide the choice of strategy for clinical use. Introduction of synthetic siRNA into cells or its stable endogenous production using vector-driven shRNA have been shown to suppress HIV replication in vitro and, in some instances, in vivo. Each method has advantages and limitations in terms of ease of delivery, duration of silencing, emergence of escape mutants and potential toxicity. Both appear to have potential as future therapeutics for HIV, once the technical and safety issues of each approach are overcome.

  19. GUItars: a GUI tool for analysis of high-throughput RNA interference screening data.

    Directory of Open Access Journals (Sweden)

    Asli N Goktug

    Full Text Available High-throughput RNA interference (RNAi screening has become a widely used approach to elucidating gene functions. However, analysis and annotation of large data sets generated from these screens has been a challenge for researchers without a programming background. Over the years, numerous data analysis methods were produced for plate quality control and hit selection and implemented by a few open-access software packages. Recently, strictly standardized mean difference (SSMD has become a widely used method for RNAi screening analysis mainly due to its better control of false negative and false positive rates and its ability to quantify RNAi effects with a statistical basis. We have developed GUItars to enable researchers without a programming background to use SSMD as both a plate quality and a hit selection metric to analyze large data sets.The software is accompanied by an intuitive graphical user interface for easy and rapid analysis workflow. SSMD analysis methods have been provided to the users along with traditionally-used z-score, normalized percent activity, and t-test methods for hit selection. GUItars is capable of analyzing large-scale data sets from screens with or without replicates. The software is designed to automatically generate and save numerous graphical outputs known to be among the most informative high-throughput data visualization tools capturing plate-wise and screen-wise performances. Graphical outputs are also written in HTML format for easy access, and a comprehensive summary of screening results is written into tab-delimited output files.With GUItars, we demonstrated robust SSMD-based analysis workflow on a 3840-gene small interfering RNA (siRNA library and identified 200 siRNAs that increased and 150 siRNAs that decreased the assay activities with moderate to stronger effects. GUItars enables rapid analysis and illustration of data from large- or small-scale RNAi screens using SSMD and other traditional analysis

  20. Dicer and Argonaute Genes Involved in RNA Interference in the Entomopathogenic Fungus Metarhizium robertsii.

    Science.gov (United States)

    Meng, Huimin; Wang, Zhangxun; Wang, Yulong; Zhu, Hong; Huang, Bo

    2017-04-01

    RNA interference (RNAi) is a gene-silencing mechanism that plays an important role in gene regulation in a number of eukaryotic organisms. Two core components, Dicer and Argonaute, are central in the RNAi machinery. However, the physiological roles of Dicer and Argonaute in the entomopathogenic fungus Metarhizium robertsii have remained unclear. Here, the roles of genes encoding Dicer ( M. robertsii dcl1 [ Mrdcl1 ] and Mrdcl2 ) and Argonaute ( Mrago1 and Mrago2 ) proteins in M. robertsii were investigated. The results showed that the Dicer-like protein MrDCL2 and Argonaute protein MrAGO1 are the major components of the RNAi process occurring in M. robertsii The Dicer and Argonaute genes were not involved in the regulation of growth and diverse abiotic stress response in M. robertsii under the tested conditions. Moreover, our results showed that the Dicer and Argonaute gene mutants demonstrated reduced abilities to produce conidia, compared to the wild type (WT) and the gene-rescued mutant. In particular, the conidial yields in the Δ dcl2 and Δ ago1 mutants were reduced by 55.8% and 59.3%, respectively, compared with those from the control strains. Subsequently, for the WT and Δ dcl2 mutant strains, digital gene expression (DGE) profiling analysis of the stage of mycelium growth and conidiogenesis revealed that modest changes occur in development or metabolism processes, which may explain the reduction in conidiation in the Δ dcl2 mutant. In addition, we further applied high-throughput sequencing technology to identify small RNAs (sRNAs) that are differentially expressed in the WT and the Δ dcl2 mutant and found that 4 known microRNA-like small RNAs (milRNAs) and 8 novel milRNAs were Mrdcl2 dependent in M. robertsii IMPORTANCE The identification and characterization of components in RNAi have contributed significantly to our understanding of the mechanism and functions of RNAi in eukaryotes. Here, we found that Dicer and Argonaute genes play an important role

  1. Rapid Generation of MicroRNA Sponges for MicroRNA Inhibition

    NARCIS (Netherlands)

    Kluiver, Joost; Gibcus, Johan H.; Hettinga, Chris; Adema, Annelies; Richter, Mareike K. S.; Halsema, Nancy; Slezak-Prochazka, Izabella; Ding, Ye; Kroesen, Bart-Jan; van den Berg, Anke

    2012-01-01

    MicroRNA (miRNA) sponges are transcripts with repeated miRNA antisense sequences that can sequester miRNAs from endogenous targets. MiRNA sponges are valuable tools for miRNA loss-of-function studies both in vitro and in vivo. We developed a fast and flexible method to generate miRNA sponges and

  2. Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA directed against malaria histone deacetylase

    International Nuclear Information System (INIS)

    Sriwilaijaroen, N.; Boonma, S.; Attasart, P.; Pothikasikorn, J.; Panyim, S.; Noonpakdee, W.

    2009-01-01

    Acetylation and deacetylation of histones play important roles in transcription regulation, cell cycle progression and development events. The steady state status of histone acetylation is controlled by a dynamic equilibrium between competing histone acetylase and deacetylase (HDAC). We have used long PfHDAC-1 double-stranded (ds)RNA to interfere with its cognate mRNA expression and determined the effect on malaria parasite growth and development. Chloroquine- and pyrimethamine-resistant Plasmodium falciparum K1 strain was exposed to 1-25 μg of dsRNA/ml of culture for 48 h and growth was determined by [ 3 H]-hypoxanthine incorporation and microscopic examination. Parasite culture treated with 10 μg/ml pfHDAC-1 dsRNA exhibited 47% growth inhibition when compared with either untreated control or culture treated with an unrelated dsRNA. PfHDAC-1 dsRNA specifically blocked maturation of trophozoite to schizont stages and decreased PfHDAC-1 transcript 44% in treated trophozoites. These results indicate the potential of HDAC-1 as a target for development of novel antimalarials.

  3. Silencing of the HER2/neu Gene by siRNA Inhibits Proliferation and Induces Apoptosis in HER2/neu-Overexpressing Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Timo Faltus

    2004-11-01

    Full Text Available In eukaryotes, double-stranded (ds RNA induces sequence-specific inhibition of gene expression referred to as RNA interference (RNAi. We exploited RNAi to define the role of HER2/neu in the neoplastic proliferation of human breast cancer cells. We transfected SK-BR-3, BT-474, MCF-7, and MDA-MB-468 breast cancer cells with short interfering RNA (siRNA targeted against human HER2/neu and analyzed the specific inhibition of HER2/neu expression by Northern and Western blots. Transfection with HER2/neu-specific siRNA resulted in a sequence-specific decrease in HER2/neu mRNA and protein levels. Moreover, transfection with HER2/neu siRNA caused cell cycle arrest at G0/G1 in the breast cancer cell lines SKBR-3 and BT-474, consistent with a powerful RNA silencing effect. siRNA treatment resulted in an antiproliferative and apoptotic response in cells overexpressing HER2/neu, but had no influence in cells with almost no expression of HER2/neu proteins like MDA-MB-468 cells. These data indicate that HER2/neu function is essential for the proliferation of HER2/neuoverexpressing breast cancer cells. Our observations suggest that siRNA targeted against human HER2/neu may be valuable tools as anti proliferative agents that display activity against neoplastic cells at very low doses.

  4. Selective inhibition of precursor incorporation into ribosomal RNA in gamma-irradiated Tetrahymena pyriformis

    International Nuclear Information System (INIS)

    Ernst, S.G.; Oleinick, N.L.; Rustad, R.C.; Greenblatt, R.M.

    1979-01-01

    Sublethal doses of γ radiation are known to inhibit total RNA synthesis in the ciliate protozoan Tetrahymena. To determine if the synthesis of a particular class of RNA is preferentially inhibited, pulse-labeled RNA was isolated from normal exponentially growing cells, irradiated cells, and cells in which total RNA synthesis had recovered to the pre-irradiation level. The RNAs were analyzed by SDS-polyacrylamide gel electrphoresis and oligo(dT)-cellulose column chromatography. Inhibition of RNA synthesis primarily involves ribosomal RNA. However, radiation does not cause a delay in the processing of precursor rRNA or a preferential loss of either of the mature rRNAs. Following irradiation, poly(A)-containing RNA [poly(A+)RNA] is synthesized at a rate up to three times greater than the control rate. The elevated poly(A+)RNA synthesis occurs during the period of depressed rRNA synthesis and even after rRNA synthesis has recovered to its pre-irradiation rate. While the sizes of the total cellular ribonucleoside triphosphate pools are depressed in the irradiated cells, these pools probably do not represent the actual compartments containing the precursors for RNA synthesis, and the observed changes cannot explain the modifications in macromolecular synthesis in irradiated Tetrahymena. (Auth.)

  5. Defective RNA particles derived from Tomato black ring virus genome interfere with the replication of parental virus.

    Science.gov (United States)

    Hasiów-Jaroszewska, Beata; Minicka, Julia; Zarzyńska-Nowak, Aleksandra; Budzyńska, Daria; Elena, Santiago F

    2018-05-02

    Tomato black ring virus (TBRV) is the only member of the Nepovirus genus that is known to form defective RNA particles (D RNAs) during replication. Here, de novo generation of D RNAs was observed during prolonged passages of TBRV isolates originated from Solanum lycopersicum and Lactuca sativa in Chenopodium quinoa plants. D RNAs of about 500 nt derived by a single deletion in the RNA1 molecule and contained a portion of the 5' untranslated region and viral replicase, and almost the entire 3' non-coding region. Short regions of sequence complementarity were found at the 5' and 3' junction borders, which can facilitate formation of the D RNAs. Moreover, in this study we analyzed the effects of D RNAs on TBRV replication and symptoms development of infected plants. C. quinoa, S. lycopersicum, Nicotiana tabacum, and L. sativa were infected with the original TBRV isolates (TBRV-D RNA) and those containing additional D RNA particles (TBRV + D RNA). The viral accumulation in particular hosts was measured up to 28 days post inoculation by RT-qPCR. Statistical analyses revealed that D RNAs interfere with TBRV replication and thus should be referred to as defective interfering particles. The magnitude of the interference effect depends on the interplay between TBRV isolate and host species. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. RNA interference can rebalance the nitrogen sink of maize seeds without losing hard endosperm.

    Directory of Open Access Journals (Sweden)

    Yongrui Wu

    Full Text Available BACKGROUND: One of the goals of plant breeding is to create crops to provide better nutrition for humans and livestock. Insufficient intake of protein is one of the most severe factors affecting the growth and development of children in developing countries. More than a century ago, in 1896, Hopkins initiated the well-known Illinois long-term selection for maize seed protein concentration, yielding four protein strains. By continuously accumulating QTLs, Illinois High Protein (IHP reached a protein level 2.5-fold higher than normal maize, with the most increased fraction being the zein protein, which was shown to contain no lysine soon after the long-term selection program initiated. Therefore, IHP is of little value for feeding humans and monogastric animals. Although high-lysine lines of non-vitreous mutants were based on reduced zeins, the kernel soft texture precluded their practical use. Kernel hardness in opaque 2 (o2 could be restored in quality protein maize (QPM with quantitative trait loci called o2 modifiers (Mo2s, but those did not increase total protein levels. METHODS: The most predominant zeins are the 22- and 19-kDa α-zeins. To achieve a combination of desired traits, we used RNA interference (RNAi against both α-zeins in IHP and evaluated the silencing effect by SDS-PAGE. Total protein, amino acid composition and kernel texture were analyzed. CONCLUSIONS: The α-zeins were dramatically reduced, but the high total seed protein level remained unchanged by complementary increase of non-zein proteins. Moreover, the residual zein levels still allowed for a vitreous hard seed. Such dramatic rebalancing of the nitrogen sink could have a major impact in world food supply.

  7. RNA interference reveals allatotropin functioning in larvae and adults of Spodoptera frugiperda (Lepidoptera, Noctuidae

    Directory of Open Access Journals (Sweden)

    I.T.E. Hassanien

    2014-05-01

    Full Text Available The allatotropin of S. frugiperda (Spofr-AT and its cDNA sequence were characterized 10 years ago, but no functional analyses of the peptide are available. Here we used the RNA interference technique to study the effects of Spofr-AT gene suppression on juvenile hormone (JH and ecdysteroid titers in the hemolymph of larvae, virgin and mated females, and of males. Spofr-AT gene silencing in last instar larvae resulted in an increase in the amount of JH III and 20-hydroxyecdysone in the hemolymph of the animals, corresponding to an acceleration of the prepupal commitment and transformation to the pupa. Mated females showed much higher JH titers in their hemolymph than virgins and laid almost twice the number of eggs. Spofr-AT gene silencing in freshly ecdysed females led to a further increase in egg production and oviposition, but had only a minor effect on the hemoylmph JH titer. Mated females contain considerable amounts of JH I and JH II in their hemoylmph, which are thought to be received from males during copulation. To confirm this hypothesis, we measured the amount of JH homologs in the male accessory reproductive glands (MARG before mating and in the bursa copulatrix (BC of the female after mating. MARG contained high amounts of JH I and JH II, which are transferred to the BC during copulation. One day after mating, JH disappeared from the BC and was then found in the hemolymph of the females. In conclusion, Spofr-AT acts as a true allatotropin in larvae and adults of both sexes of the armyworm.

  8. Evf2 lncRNA/BRG1/DLX1 interactions reveal RNA-dependent inhibition of chromatin remodeling.

    Science.gov (United States)

    Cajigas, Ivelisse; Leib, David E; Cochrane, Jesse; Luo, Hao; Swyter, Kelsey R; Chen, Sean; Clark, Brian S; Thompson, James; Yates, John R; Kingston, Robert E; Kohtz, Jhumku D

    2015-08-01

    Transcription-regulating long non-coding RNAs (lncRNAs) have the potential to control the site-specific expression of thousands of target genes. Previously, we showed that Evf2, the first described ultraconserved lncRNA, increases the association of transcriptional activators (DLX homeodomain proteins) with key DNA enhancers but represses gene expression. In this report, mass spectrometry shows that the Evf2-DLX1 ribonucleoprotein (RNP) contains the SWI/SNF-related chromatin remodelers Brahma-related gene 1 (BRG1, SMARCA4) and Brahma-associated factor (BAF170, SMARCC2) in the developing mouse forebrain. Evf2 RNA colocalizes with BRG1 in nuclear clouds and increases BRG1 association with key DNA regulatory enhancers in the developing forebrain. While BRG1 directly interacts with DLX1 and Evf2 through distinct binding sites, Evf2 directly inhibits BRG1 ATPase and chromatin remodeling activities. In vitro studies show that both RNA-BRG1 binding and RNA inhibition of BRG1 ATPase/remodeling activity are promiscuous, suggesting that context is a crucial factor in RNA-dependent chromatin remodeling inhibition. Together, these experiments support a model in which RNAs convert an active enhancer to a repressed enhancer by directly inhibiting chromatin remodeling activity, and address the apparent paradox of RNA-mediated stabilization of transcriptional activators at enhancers with a repressive outcome. The importance of BRG1/RNA and BRG1/homeodomain interactions in neurodevelopmental disorders is underscored by the finding that mutations in Coffin-Siris syndrome, a human intellectual disability disorder, localize to the BRG1 RNA-binding and DLX1-binding domains. © 2015. Published by The Company of Biologists Ltd.

  9. Effects of short-hairpin RNA-inhibited {beta}-catenin expression on the growth of human multiple myeloma cells in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wenqing, E-mail: liangwenqing_1234@126.com [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Yang, Chengwei [Department of Spinal Surgery, Lanzhou General Hospital, Lanzhou Military Area Command, 333 Nanbinhe Road, Lanzhou 730050 (China); Qian, Yu [Department of Orthopaedics, Shaoxing People' s Hospital, 568 Zhongxing North Road, Shaoxing 312000 (China); Fu, Qiang, E-mail: chyygklwq@hotmail.com [Department of Orthopaedics, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai 200433 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer {beta}-Catenin expression were markedly down-regulated by CTNNB1 shRNA. Black-Right-Pointing-Pointer CTNNB1 shRNA could inhibit the proliferation of RPMI8226 cells. Black-Right-Pointing-Pointer Significantly profound apoptotic cell death in CTNNB1 shRNA cells. Black-Right-Pointing-Pointer In vivo, CTNNB1 silence led to a growth inhibition of myeloma growth. Black-Right-Pointing-Pointer c-myc and {beta}-catenin in the expression cells of cleaved caspase-3 were increased. -- Abstract: Multiple myeloma (MM) is thrombogenic as a consequence of multiple hemostatic effects. Overexpression of {beta}-catenin has been observed in several types of malignant tumors, including MM. However, the relationship between {beta}-catenin expression and MM remains unclear. In the present study, RNA interference was used to inhibit {beta}-catenin expression in RPMI8226 cells. RT-PCR and Western blotting analyses showed that {beta}-catenin mRNA and protein expression were markedly down-regulated by CTNNB1 shRNA. Western blotting showed that the protein levels of cyclin D1 and glutamine synthetase were downregulated and supported the transcriptional regulatory function of {beta}-catenin. The MTT assay showed that CTNNB1 shRNA could have significant inhibitory effects on the proliferation of RPMI8226 cells. The TOPflash reporter assay demonstrated significant downregulation after CTNNB1 shRNA transfection in RPMI8226 cells. Flow cytometric analyses also showed significantly profound apoptosis in CTNNB1 shRNA cells. We found CTNNB1 silence led to growth inhibition of MM growth in vivo. Immunohistochemical analyses showed that c-myc and {beta}-catenin were reduced in CTNNB1 shRNA tumor tissues, but that expression of cleaved caspase-3 was increased. These results show that {beta}-catenin could be a new therapeutic agent that targets the biology of MM cells.

  10. Technical advances in trigger-induced RNA interference gene silencing in the parasite Entamoeba histolytica.

    Science.gov (United States)

    Khalil, Mohamed I; Foda, Bardees M; Suresh, Susmitha; Singh, Upinder

    2016-03-01

    Entamoeba histolytica has a robust endogenous RNA interference (RNAi) pathway. There are abundant 27 nucleotide (nt) anti-sense small RNAs (AS sRNAs) that target genes for silencing and the genome encodes many genes involved in the RNAi pathway such as Argonaute proteins. Importantly, an E. histolytica gene with numerous AS sRNAs can function as a "trigger" to induce silencing of a gene that is fused to the trigger. Thus, the amebic RNAi pathway regulates gene expression relevant to amebic biology and has additionally been harnessed as a tool for genetic manipulation. In this study we have further improved the trigger-induced gene silencing method. We demonstrate that rather than using the full-length gene, a short portion of the coding region fused to a trigger is sufficient to induce silencing; the first 537 bp of the E. histolytica rhomboid gene (EhROM1) fused in-frame to the trigger was sufficient to silence EhROM1. We also demonstrated that the trigger method could silence two amebic genes concomitantly; fusion of the coding regions of EhROM1 and transcription factor, EhMyb, in-frame to a trigger gene resulted in both genes being silenced. Alternatively, two genes can be silenced sequentially: EhROM1-silenced parasites with no drug selection plasmid were transfected with trigger-EhMyb, resulting in parasites with both EhROM1 and EhMyb silenced. With all approaches tested, the trigger-mediated silencing was substantive and silencing was maintained despite loss of the G418 selectable marker. All gene silencing was associated with generation of AS sRNAs to the silenced gene. We tested the reversibility of the trigger system using inhibitors of histone modifications but found that the silencing was highly stable. This work represents a technical advance in the trigger gene silencing method in E. histolytica. Approaches that readily silence multiple genes add significantly to the genetic toolkit available to the ameba research community. Copyright © 2016

  11. Lentivirus-mediated RNA interference of vascular endothelial growth factor in monkey eyes with iris neovascularization.

    Science.gov (United States)

    Yuan, Meng-Ke; Tao, Yong; Yu, Wen-Zhen; Kai, Wang; Jiang, Yan-Rong

    2010-08-25

    To explore the in vivo anti-angiogenesis effects resulting from lentivirus-mediated RNAi of vascular endothelial growth factor (VEGF) in monkeys with iris neovascularization (INV). Five specific recombinant lentiviral vectors for RNA interference, targeting Macaca mulatta VEGFA, were designed and the one with best knock down efficacy (LV-GFP-VEGFi1) in H1299 cells and RF/6A cells was selected by real-time PCR for in vivo use. A laser-induced retinal vein occlusion model was established in one eye of seven cynomolgus monkeys. In monkeys number 1, 3, and 5 (Group 1), the virus (1x10(8) particles) was intravitreally injected into the preretinal space of the animal's eye immediately after laser coagulation; and in monkeys number 2, 4, and 6 (Group 2), the virus (1x10(8) particles) was injected at 10 days after laser coagulation. In monkey number 7, a blank control injection was performed. In monkeys number 1 and 2, virus without RNAi sequence was used; in monkeys number 3 and 4, virus with nonspecific RNAi sequence was used; and in monkeys 5 and 6, LV-GFP-VEGFi1 was used. In monkey number 5, at 23 days after laser treatment, no obvious INV was observed, while fluorescein angiography of the iris revealed high fluorescence at the margin of pupil and point posterior synechiae. At 50 days after laser treatment, only a slight ectropion uvea was found. However, in the other eyes, obvious INV or hyphema was observed. The densities of new iridic vessels all significantly varied: between monkey number 5 and number 3 (36.01+/-4.49/mm(2) versus 48.68+/-9.30/mm(2), p=0.025), between monkey number 3 and monkey number 7 (48.68+/-9.30/mm(2) versus 74.38+/-9.23/mm(2), p=0.002), and between monkey number 5 and number 7 (36.01+/-4.49/mm(2) versus 74.38+/-9.23/mm(2), p<0.001). Lentivirus-mediated RNAi of VEGF may be a new strategy to treat iris neovascularization, while further studies are needed to investigate the long-term effect.

  12. [Inhibitory effect of RNA interference targeting GFI-1 on the proliferation of atypical chronic myelogenous leukemia NT1 cells].

    Science.gov (United States)

    Yang, X; Liu, H; Lin, Z H; Qian, J; Xu, X R

    2016-08-01

    To investigate the inhibitory effects of RNA interference targeting GFI-1 on growth and proliferation of atypical chronic myelogenous leukemia (aCML) NT1 cells. NT1 cells were transfected with PBS and liposome complex (vehicle group), scrambled siRNA and liposome complex (negative control, NC group), and GFI-1 siRNA and liposome complex (GFI-1 siRNA group), respectively. Real-time quantitative RT-PCR (qRT-PCR) and Western blot were performed to examine the expression levels of GFI-1 mRNA and protein, respectively. The proliferation abilities of NT1 cells of the three groups were evaluated by MTT assay. The cell cycle in cells of the three groups was analyzed by flow cytometry. Moreover, nude mouse xenograft model was used to detect the tumor formation ability in the three group cells. Quantitative real-time PCR data showed that the expression level of GFI-1 mRNA in GFI-1 siRNA group was significantly lower than those of NC group and vehicle group [(0.367±0.017) vs. (0.918±0.006) and (1.010±0.005), respectively, (PNT1 cells in the GFI-1 siRNA group (0.667±0.059) was significantly lower than those of the NC group (1.096±0.049) and vehicle group (1.193±0.064, P=0.023). Flow cytometry data showed that sub-G1 and G0/G1 phase proportions of the GFI-1 siRNA group were significantly higher than those of the NC and vehicle groups [sub-G1: (8.2±2.5)% vs. (1.9±1.3)% and (2.0±3.6)%, respectively, (PNT1 cells, which may provide a new therapeutic target for atypical chronic myelogenous leukemia.

  13. Heavy ion effects on yeast: Inhibition of ribosomal RNA synthesis

    International Nuclear Information System (INIS)

    Weber, K.J.; Schneider, E.; Kiefer, J.; Kraft, G.

    1990-01-01

    Diploid wild-type yeast cells were exposed to beams of heavy ions covering a wide range of linear energy transfer (LET) (43-13,700 keV/microns). Synthesis of ribosomal RNA (rRNA) was assessed as a functional measure of damage produced by particle radiation. An exponential decrease of relative rRNA synthesis with particle fluence was demonstrated in all cases. The inactivation cross sections derived were found to increase with LET over the entire range of LET studied. The corresponding values for relative biological effectiveness were slightly less than unity. Maximum cross sections measured were close to 1 micron 2, implying that some larger structure within the yeast nucleus (e.g., the nucleolus) might represent the target for an impairment of synthetic activity by very heavy ions rather than the genes coding for rRNA. Where tested, an oxygen effect for rRNA synthesis could not be demonstrated

  14. The role of outcome inhibition in interference between outcomes: a contingency-learning analogue of retrieval-induced forgetting.

    Science.gov (United States)

    Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Cobos, Pedro L; López, Francisco J; Matute, Helena

    2013-05-01

    Current associative theories of contingency learning assume that inhibitory learning plays a part in the interference between outcomes. However, it is unclear whether this inhibitory learning results in the inhibition of the outcome representation or whether it simply counteracts previous excitatory learning so that the outcome representation is neither activated nor inhibited. Additionally, these models tend to conceptualize inhibition as a relatively transient and cue-dependent state. However, research on retrieval-induced forgetting suggests that the inhibition of representations is a real process that can be relatively independent of the retrieval cue used to access the inhibited information. Consistent with this alternative view, we found that interference between outcomes reduces the retrievability of the target outcome even when the outcome is associated with a novel (non-inhibitory) cue. This result has important theoretical implications for associative models of interference and shows that the empirical facts and theories developed in studies of retrieval-induced forgetting might be relevant in contingency learning and vice versa. © 2012 The British Psychological Society.

  15. Platinum Interference with siRNA Non-seed Regions Fine-Tunes Silencing Capacity

    DEFF Research Database (Denmark)

    Hedman, Hanna K; Kirpekar, Finn; Elmroth, Sofi K C

    2011-01-01

    expression, and the other one focused on the function of endogenous miRNAs. In both cases, the active molecule consists of a ∼20-nucleotide-long RNA duplex. In the siRNA case, improved systemic stability is of central interest for its further development toward clinical applications. With respect to mi......RNA processing and function, understanding its influence on mRNA targeting and the silencing ability of individual miRNAs, e.g., under pathological conditions, remains a scientific challenge. In the present study, a model system is presented where the influence of the two clinically used anticancer drugs......, cisplatin and oxaliplatin, on siRNA's silencing capacity has been evaluated. More specifically, siRNAs targeting the 3' UTR region of Wnt-5a mRNA (NM_003352) were constructed, and the biologically active antisense RNA strand was pre-platinated. Platinum adducts were detected and characterized...

  16. Inhibitors of MyD88-dependent proinflammatory cytokine production identified utilizing a novel RNA interference screening approach.

    Directory of Open Access Journals (Sweden)

    John S Cho

    2009-09-01

    Full Text Available The events required to initiate host defenses against invading pathogens involve complex signaling cascades comprised of numerous adaptor molecules, kinases, and transcriptional elements, ultimately leading to the production of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha. How these signaling cascades are regulated, and the proteins and regulatory elements participating are still poorly understood.We report here the development a completely random short-hairpin RNA (shRNA library coupled with a novel forward genetic screening strategy to identify inhibitors of Toll-like receptor (TLR dependent proinflammatory responses. We developed a murine macrophage reporter cell line stably transfected with a construct expressing diphtheria toxin-A (DT-A under the control of the TNF-alpha-promoter. Stimulation of the reporter cell line with the TLR ligand lipopolysaccharide (LPS resulted in DT-A induced cell death, which could be prevented by the addition of an shRNA targeting the TLR adaptor molecule MyD88. Utilizing this cell line, we screened a completely random lentiviral short hairpin RNA (shRNA library for sequences that inhibited TLR-mediated TNF-alpha production. Recovery of shRNA sequences from surviving cells led to the identification of unique shRNA sequences that significantly inhibited TLR4-dependent TNF-alpha gene expression. Furthermore, these shRNA sequences specifically blocked TLR2 but not TLR3-dependent TNF-alpha production.Thus, we describe the generation of novel tools to facilitate large-scale forward genetic screens in mammalian cells and the identification of potent shRNA inhibitors of TLR2 and TLR4- dependent proinflammatory responses.

  17. LNA-modified oligonucleotides mediate specific inhibition of microRNA function

    DEFF Research Database (Denmark)

    Ørom, Ulf Andersson; Kauppinen, Sakari; Lund, Anders H

    2006-01-01

    microRNAs are short, endogenous non-coding RNAs that act as post-transcriptional modulators of gene expression. Important functions for microRNAs have been found in the regulation of development, cellular proliferation and differentiation, while perturbed miRNA expression patterns have been...... observed in many human cancers. Here we present a method for specific inhibition of miRNA function through interaction with LNA-modified antisense oligonucleotides and report the specificity of this application. We show that LNA-modified oligonucleotides can inhibit exogenously introduced miRNAs with high...... specificity using a heterologous reporter assay, and furthermore demonstrate their ability to inhibit an endogenous miRNA in Drosophila melanogaster cells, leading to up-regulation of the cognate target protein. The method shows stoichiometric and reliable inhibition of the targeted miRNA and can thus...

  18. Delivery of dsRNA through topical feeding for RNA interference in the citrus sap piercing-sucking hemipteran, Diaphorina citri.

    Science.gov (United States)

    Killiny, Nabil; Kishk, Abdelaziz

    2017-06-01

    RNA interference (RNAi) is a powerful means to study functional genomics in insects. The delivery of dsRNA is a challenging step in the development of RNAi assay. Here, we describe a new delivery method to increase the effectiveness of RNAi in the Asian citrus psyllid Diaphorina citri. Bromophenol blue droplets were topically applied to fifth instar nymphs and adults on the ventral side of the thorax between the three pairs of legs. In addition to video recordings that showed sucking of the bromophenol blue by the stylets, dissected guts turned blue indicating that the uptake was through feeding. Thus, we called the method topical feeding. We targeted the abnormal wing disc gene (awd), also called nucleoside diphosphate kinase (NDPK), as a reporter gene to prove the uptake of dsRNA via this method of delivery. Our results showed that dsRNA-awd caused reduction of awd expression and nymph mortality. Survival and lifespan of adults emerged from treated nymphs and treated adults were affected. Silencing awd caused wing malformation in the adults emerged from treated nymphs. Topical feeding as a delivery of dsRNA is highly efficient for both nymphs and adults. The described method could be used to increase the efficiency of RNAi in D. citri and other sap piercing-sucking hemipterans. © 2017 Wiley Periodicals, Inc.

  19. Improving model predictions for RNA interference activities that use support vector machine regression by combining and filtering features

    Directory of Open Access Journals (Sweden)

    Peek Andrew S

    2007-06-01

    Full Text Available Abstract Background RNA interference (RNAi is a naturally occurring phenomenon that results in the suppression of a target RNA sequence utilizing a variety of possible methods and pathways. To dissect the factors that result in effective siRNA sequences a regression kernel Support Vector Machine (SVM approach was used to quantitatively model RNA interference activities. Results Eight overall feature mapping methods were compared in their abilities to build SVM regression models that predict published siRNA activities. The primary factors in predictive SVM models are position specific nucleotide compositions. The secondary factors are position independent sequence motifs (N-grams and guide strand to passenger strand sequence thermodynamics. Finally, the factors that are least contributory but are still predictive of efficacy are measures of intramolecular guide strand secondary structure and target strand secondary structure. Of these, the site of the 5' most base of the guide strand is the most informative. Conclusion The capacity of specific feature mapping methods and their ability to build predictive models of RNAi activity suggests a relative biological importance of these features. Some feature mapping methods are more informative in building predictive models and overall t-test filtering provides a method to remove some noisy features or make comparisons among datasets. Together, these features can yield predictive SVM regression models with increased predictive accuracy between predicted and observed activities both within datasets by cross validation, and between independently collected RNAi activity datasets. Feature filtering to remove features should be approached carefully in that it is possible to reduce feature set size without substantially reducing predictive models, but the features retained in the candidate models become increasingly distinct. Software to perform feature prediction and SVM training and testing on nucleic acid

  20. RNA Interference: A Promising Tool in the Control of Important Vector Born Diseases Zika, Dengue Fever, and Malaria

    Directory of Open Access Journals (Sweden)

    Jalil Nejati

    2017-05-01

    Full Text Available Background and Objectives: RNA interference is a process, in which a molecule of double-stranded RNA prevents the expression of a particular gene and leads to its silencing. Application of this technology in the control of disease-carrying insects is rising in agriculture and medical sciences. Also, its application in control of insect-borne diseases could be considered as a new, important, and effective approach. In this article, it was attempted to study the mechanisms of RNA interference, routs of its delivery to insects, as well as its application in genetic control of disease vector insects. Methods: In this study, 71 indexed articles in databases, such as Pubmed, SID, Scopus, Science direct, and Google scholar, were used. Results: dsRNA could be delivered to insect body through three routes of oral, injection, and Impregnation. The mechanism of dsRNA entrance into the cells has considerable effect on the success and applicability of this technique. Identification of host-parasite relationship in the insect body is one of the important applications of RNAi in medical entomology. Conclusion: Although, there is a considerable number of researches on RNAi in the agricultural pests field, studies on insect vectors of human diseases have been mostly in-vivo. However, application of RNAi is suggested as a new, safe and applicable approach, alone or along with other methods. Certainly, further researches in this field can pave the way for enforcement measures in the control of disease vectors, especially Zika, dengue fever, and malaria in the not so distant future.

  1. Catalytic mechanism and inhibition of tRNA (Uracil-5-)methyltransferase: evidence for covalent catalysis

    International Nuclear Information System (INIS)

    Santi, D.V.; Hardy, L.W.

    1987-01-01

    tRNA (Ura-5-) methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine (AdoMet) to the 5-carbon of a specific Urd residue in tRNA. This results in stoichiometric release of tritium from [5- 3 H] Urd-labeled substrate tRNA isolated from methyltransferase-deficient Escherichia coli. The enzyme also catalyzes an AdoMet-independent exchange reaction between [5- 3 H]-Urd-labeled substrate tRNA and protons of water at a rate that is about 1% that of the normal methylation reaction, but with identical stoichiometry. S-Adenosylhomocysteine inhibits the rate of the exchange reaction by 2-3-fold, whereas an analog having the sulfur of AdoMet replaced by nitrogen accelerates the exchange reaction 9-fold. In the presence (but not absence) of AdoMet, 5-fluorouracil-substituted tRNA (FUra-tRNA) leads to the first-order inactivation of the enzyme. This is accompanied by the formation of a stable covalent complex containing the enzyme, FUra-tRNA, and the methyl group AdoMet. A mechanism for catalysis is proposed that explains both the 5-H exchange reaction and the inhibition by FUra-tRNA: the enzyme forms a covalent Michael adduct with substrate or inhibitor tRNA by attack of a nucleophilic group of the enzyme at carbon 6 of the pyrimidine residue to be modified. As a result, an anion equivalent is generated at carbon 5 that is sufficiently reactive to be methylated by AdoMet. Preliminary experiments and precedents suggest that the nucleophilic catalyst of the enzyme is a thiol group of cysteine. The potent irreversible inhibition by FUra-tRNA suggest that a mechanism for the RNA effects of FUra may also involve irreversible inhibition of RNA-modifying enzymes

  2. Adeno-Associated Viral Vector-Mediated mTOR Inhibition by Short Hairpin RNA Suppresses Laser-Induced Choroidal Neovascularization

    Directory of Open Access Journals (Sweden)

    Tae Kwann Park

    2017-09-01

    Full Text Available Choroidal neovascularization (CNV is the defining characteristic feature of the wet subtype of age-related macular degeneration (AMD and may result in irreversible blindness. Based on anti-vascular endothelial growth factor (anti-VEGF, the current therapeutic approaches to CNV are fraught with difficulties, and mammalian target of rapamycin (mTOR has recently been proposed as a possible therapeutic target, although few studies have been conducted. Here, we show that a recombinant adeno-associated virus-delivered mTOR-inhibiting short hairpin RNA (rAAV-mTOR shRNA, which blocks the activity of both mTOR complex 1 and 2, represents a promising therapeutic approach for the treatment of CNV. Eight-week-old male C57/B6 mice were treated with the short hairpin RNA (shRNA after generating CNV lesions in the eyes via laser photocoagulation. The recombinant adeno-associated virus (rAAV delivery vehicle was able to effectively transduce cells in the inner retina, and significantly fewer inflammatory cells and less extensive CNV were observed in the animals treated with rAAV-mTOR shRNA when compared with control- and rAAV-scrambled shRNA-treated groups. Presumably related to the reduction of CNV, increased autophagy was detected in CNV lesions treated with rAAV-mTOR shRNA, whereas significantly fewer apoptotic cells detected in the outer nuclear layer around the CNV indicate that mTOR inhibition may also have neuroprotective effects. Taken together, these results demonstrate the therapeutic potential of mTOR inhibition, resulting from rAAV-mTOR shRNA activity, in the treatment of AMD-related CNV. Keywords: retinal neovascularization, choroidal neovascularization, adeno-associated virus, mTOR, RNA interference, mTOR shRNA, autophagy

  3. A Polyamide Inhibits Replication of Vesicular Stomatitis Virus by Targeting RNA in the Nucleocapsid

    Energy Technology Data Exchange (ETDEWEB)

    Gumpper, Ryan H.; Li, Weike; Castañeda, Carlos H.; Scuderi, M. José; Bashkin, James K.; Luo, Ming; Dutch, Rebecca Ellis

    2018-02-07

    Polyamides have been shown to bind double-stranded DNA by complementing the curvature of the minor groove and forming various hydrogen bonds with DNA. Several polyamide molecules have been found to have potent antiviral activities against papillomavirus, a double-stranded DNA virus. By analogy, we reason that polyamides may also interact with the structured RNA bound in the nucleocapsid of a negative-strand RNA virus. Vesicular stomatitis virus (VSV) was selected as a prototype virus to test this possibility since its genomic RNA encapsidated in the nucleocapsid forms a structure resembling one strand of an A-form RNA duplex. One polyamide molecule, UMSL1011, was found to inhibit infection of VSV. To confirm that the polyamide targeted the nucleocapsid, a nucleocapsid-like particle (NLP) was incubated with UMSL1011. The encapsidated RNA in the polyamide-treated NLP was protected from thermo-release and digestion by RNase A. UMSL1011 also inhibits viral RNA synthesis in the intracellular activity assay for the viral RNA-dependent RNA polymerase. The crystal structure revealed that UMSL1011 binds the structured RNA in the nucleocapsid. The conclusion of our studies is that the RNA in the nucleocapsid is a viable antiviral target of polyamides. Since the RNA structure in the nucleocapsid is similar in all negative-strand RNA viruses, polyamides may be optimized to target the specific RNA genome of a negative-strand RNA virus, such as respiratory syncytial virus and Ebola virus.

    IMPORTANCENegative-strand RNA viruses (NSVs) include several life-threatening pathogens, such as rabies virus, respiratory syncytial virus, and Ebola virus. There are no effective antiviral drugs against these viruses. Polyamides offer an exceptional opportunity because they may be optimized to target each NSV. Our studies on vesicular stomatitis virus, an NSV, demonstrated that a polyamide molecule could specifically target the viral RNA in the nucleocapsid and inhibit

  4. Interference by clustered regularly interspaced short palindromic repeat (CRISPR) RNA is governed by a seed sequence

    NARCIS (Netherlands)

    Semenova, E.V.; Jore, M.M.; Westra, E.R.; Oost, van der J.; Brouns, S.J.J.

    2011-01-01

    Prokaryotic clustered regularly interspaced short palindromic repeat (CRISPR)/Cas (CRISPR-associated sequences) systems provide adaptive immunity against viruses when a spacer sequence of small CRISPR RNA (crRNA) matches a protospacer sequence in the viral genome. Viruses that escape CRISPR/Cas

  5. Decreased expression of RNA interference machinery, Dicer and Drosha, is associated with poor outcome in ovarian cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Merritt, William M.; Lin, Yvonne G.; Han, Liz Y.; Kamat, Aparna A.; Spannuth, Whitney A.; Schmandt, Rosemarie; Urbauer, Diana; Pennacchio, Len A.; Cheng, Jan-Fang; Zeidan, Alexandra; Wang, Hua; Mueller, Peter; Lenburg, Marc E.; Gray, Joe W.; Mok, Samuel; Birrer, Michael J.; Lopez-Berestein, Gabriel; Coleman, Robert L.; Bar-Eli, Menashe; Sood, Anil K.

    2008-05-06

    The clinical and functional significance of RNA interference (RNAi) machinery, Dicer and Drosha, in ovarian cancer is not known and was examined. Dicer and Drosha expression was measured in ovarian cancer cell lines (n=8) and invasive epithelial ovarian cancer specimens (n=111) and correlated with clinical outcome. Validation was performed with previously published cohorts of ovarian, breast, and lung cancer patients. Anti-Galectin-3 siRNA and shRNA transfections were used for in vitro functional studies. Dicer and Drosha mRNA and protein levels were decreased in 37% to 63% of ovarian cancer cell lines and in 60% and 51% of human ovarian cancer specimens, respectively. Low Dicer was significantly associated with advanced tumor stage (p=0.007), and low Drosha with suboptimal surgical cytoreduction (p=0.02). Tumors with both high Dicer and Drosha were associated with increased median patient survival (>11 years vs. 2.66 years for other groups; p<0.001). In multivariate analysis, high Dicer (HR=0.48; p=0.02), high-grade histology (HR=2.46; p=0.03), and poor chemoresponse (HR=3.95; p<0.001) were identified as independent predictors of disease-specific survival. Findings of poor clinical outcome with low Dicer expression were validated in separate cohorts of cancer patients. Galectin-3 silencing with siRNA transfection was superior to shRNA in cell lines with low Dicer (78-95% vs. 4-8% compared to non-targeting sequences), and similar in cell lines with high Dicer. Our findings demonstrate the clinical and functional impact of RNAi machinery alterations in ovarian carcinoma and support the use of siRNA constructs that do not require endogenous Dicer and Drosha for therapeutic applications.

  6. Enhanced eyeblink conditioning in behaviorally inhibited individuals is disrupted by proactive interference following US alone pre-exposures.

    Directory of Open Access Journals (Sweden)

    Michael Todd Allen

    2016-03-01

    Full Text Available Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from CS or US alone pre-exposures (Holloway et al., 2012. US alone pre-exposures disrupt subsequent CR acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al., (2012 reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioural Inhibition (AMBI. Sixty six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI individuals exhibited enhanced proactive interference as compared to non-inhibited (NI individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible learned helplessness. Applications of these findings of

  7. Interference and Inhibition in Tasks of Selective Attention by Persons with and without Mental Retardation

    Science.gov (United States)

    Merrill, Edward C.

    2006-01-01

    Persons with mental retardation often exhibit greater interference in visual selective attention tasks than do persons matched with them on CA. My goal here was to evaluate whether differences in distractor interference between persons with and without mental retardation may be related to differences in negative priming. Fifteen participants with…

  8. RNA Interference towards the Potato Psyllid, Bactericera cockerelli, Is Induced in Plants Infected with Recombinant Tobacco mosaic virus (TMV)

    Science.gov (United States)

    Wuriyanghan, Hada; Falk, Bryce W.

    2013-01-01

    The potato/tomato psyllid, Bactericera cockerelli (B. cockerelli), is an important plant pest and the vector of the phloem-limited bacterium Candidatus Liberibacter psyllaurous (solanacearum), which is associated with the zebra chip disease of potatoes. Previously, we reported induction of RNA interference effects in B. cockerelli via in vitro-prepared dsRNA/siRNAs after intrathoracic injection, and after feeding of artificial diets containing these effector RNAs. In order to deliver RNAi effectors via plant hosts and to rapidly identify effective target sequences in plant-feeding B. cockerelli, here we developed a plant virus vector-based in planta system for evaluating candidate sequences. We show that recombinant Tobacco mosaic virus (TMV) containing B. cockerelli sequences can efficiently infect and generate small interfering RNAs in tomato (Solanum lycopersicum), tomatillo (Physalis philadelphica) and tobacco (Nicotiana tabacum) plants, and more importantly delivery of interfering sequences via TMV induces RNAi effects, as measured by actin and V-ATPase mRNA reductions, in B. cockerelli feeding on these plants. RNAi effects were primarily detected in the B. cockerelli guts. In contrast to our results with TMV, recombinant Potato virus X (PVX) and Tobacco rattle virus (TRV) did not give robust infections in all plants and did not induce detectable RNAi effects in B. cockerelli. The greatest RNA interference effects were observed when B. cockerelli nymphs were allowed to feed on leaf discs collected from inoculated or lower expanded leaves from corresponding TMV-infected plants. Tomatillo plants infected with recombinant TMV containing B. cockerelli actin or V-ATPase sequences also showed phenotypic effects resulting in decreased B. cockerelli progeny production as compared to plants infected by recombinant TMV containing GFP. These results showed that RNAi effects can be achieved in plants against the phloem feeder, B. cockerelli, and the TMV-plant system will

  9. Major and minor crRNA annealing sites facilitate low stringency DNA protospacer binding prior to Type I-A CRISPR-Cas interference in Sulfolobus

    DEFF Research Database (Denmark)

    Mousaei, Marzieh; Deng, Ling; She, Qunxin

    2016-01-01

    The stringency of crRNA-protospacer DNA base pair matching required for effective CRISPR-Cas interference is relatively low in crenarchaeal Sulfolobus species in contrast to that required in some bacteria. To understand its biological significance we studied crRNA-protospacer interactions...... in Sulfolobus islandicus REY15A which carries multiple, and functionally diverse, interference complexes. A range of mismatches were introduced into a vector-borne protospacer that was identical to spacer 1 of CRISPR locus 2, with a cognate CCN PAM sequence. Two important crRNA annealing regions were identified...

  10. RNA interference for the control of whiteflies (Bemisia tabaci) by oral ...

    Indian Academy of Sciences (India)

    respective primers (table 2), and actin served as the internal control. Each reaction ..... emerged adults and variation in the quality and the quantity of siRNA synthesized ... Environment News Service, 21 August (countercurrents.org). Febvay G ...

  11. Transcriptome analysis and RNA interference of cockroach phototransduction indicate three opsins and suggest a major role for TRPL channels

    Directory of Open Access Journals (Sweden)

    Andrew S French

    2015-07-01

    Full Text Available Our current understanding of insect phototransduction is based on a small number of species, but insects occupy many different visual environments. We created the retinal transcriptome of a nocturnal insect, the cockroach, Periplaneta americana to identify proteins involved in the earliest stages of compound eye phototransduction, and test the hypothesis that different visual environments are reflected in different molecular contributions to function. We assembled five novel mRNAs: two green opsins, one UV opsin, and one each TRP and TRPL ion channel homologs. One green opsin mRNA (pGO1 was 100-1000 times more abundant than the other opsins (pGO2 and pUVO, while pTRPL mRNA was 10 times more abundant than pTRP, estimated by transcriptome analysis or quantitative PCR (qPCR. Electroretinograms were used to record photoreceptor responses. Gene-specific in vivo RNA interference (RNAi was achieved by injecting long (596-708 bp double-stranded RNA into head hemolymph, and verified by qPCR. RNAi of the most abundant green opsin reduced both green opsins by more than 97% without affecting UV opsin, and gave a maximal reduction of 75% in ERG amplitude seven days after injection that persisted for at least 19 days. RNAi of pTRP and pTRPL genes each specifically reduced the corresponding mRNA by 90%. Electroretinogram reduction by pTRPL RNAi was slower than for opsin, reaching 75% attenuation by 21 days, without recovery at 29 days. pTRP RNAi attenuated ERG much less; only 30% after 21 days. Combined pTRP plus pTRPL RNAi gave only weak evidence of any cooperative interactions. We conclude that silencing retinal genes by in vivo RNAi using long dsRNA is effective, that visible light transduction in Periplaneta is dominated by pGO1, and that pTRPL plays a major role in cockroach phototransduction.

  12. Involvement of activation of PKR in HBx-siRNA-mediated innate immune effects on HBV inhibition.

    Directory of Open Access Journals (Sweden)

    Qiuju Han

    Full Text Available RNA interference (RNAi of virus-specific genes offers the possibility of developing a new anti-hepatitis B virus (anti-HBV therapy. Recent studies have revealed that siRNAs can induce an innate immune response in vitro and in vivo. Here, HBVx (HBx mRNA expression and HBV replication were significantly inhibited, followed by the enhancement of expression of type I interferons (IFNs, IFN-stimulated genes (ISG15 and ISG56 and proinflammatory cytokines after HepG2.2.15 cells were transfected with chemically synthesized HBx-siRNAs. Transfection with HBx-siRNAs also significantly increased expression of dsRNA-dependent protein kinase R (PKR in HepG2.2.15 cells, followed by activation of downstream signaling events such as eukaryotic initiation factor 2α (eIF2-α. In PKR-over-expressing HepG2.2.15 cells, HBx-siRNAs exerted more potent inhibitory effects on HBV replication and greater production of type I IFNs. By contrast, the inhibitory effect of HBx-siRNAs on HBV replication was attenuated when PKR was inhibited or silenced, demonstrating that HBx-siRNAs greatly promoted PKR activation, leading to the higher production of type I IFN. Therefore, we concluded that PKR is involved in the innate immune effects mediated by HBx-siRNAs and further contributes to HBV inhibition. The bifunctional siRNAs with both gene silencing and innate immune activation properties may represent a new potential strategy for treatment of HBV.

  13. Potyviral VPg enhances viral RNA Translation and inhibits reporter mRNA translation in planta.

    Science.gov (United States)

    Eskelin, Katri; Hafrén, Anders; Rantalainen, Kimmo I; Mäkinen, Kristiina

    2011-09-01

    Viral protein genome-linked (VPg) plays a central role in several stages of potyvirus infection. This study sought to answer questions about the role of Potato virus A (PVA; genus Potyvirus) VPg in viral and host RNA expression. When expressed in Nicotiana benthamiana leaves in trans, a dual role of VPg in translation is observed. It repressed the expression of monocistronic luciferase (luc) mRNA and simultaneously induced a significant upregulation in the expression of both replicating and nonreplicating PVA RNAs. This enhanced viral gene expression was due at least to the 5' untranslated region (UTR) of PVA RNA, eukaryotic initiation factors 4E and iso 4E [eIF4E/eIF(iso)4E], and the presence of a sufficient amount of VPg. Coexpression of VPg with viral RNA increased the viral RNA amount, which was not the case with the monocistronic mRNA. Both mutations at certain lysine residues in PVA VPg and eIF4E/eIF(iso)4E depletion reduced its ability to upregulate the viral RNA expression. These modifications were also involved in VPg-mediated downregulation of monocistronic luc expression. These results suggest that VPg can titrate eIF4Es from capped monocistronic RNAs. Because VPg-mediated enhancement of viral gene expression required eIF4Es, it is possible that VPg directs eIF4Es to promote viral RNA expression. From this study it is evident that VPg can serve as a specific regulator of PVA expression by boosting the viral RNA amounts as well as the accumulation of viral translation products. Such a mechanism could function to protect viral RNA from being degraded and to secure efficient production of coat protein (CP) for virion formation.

  14. Potyviral VPg Enhances Viral RNA Translation and Inhibits Reporter mRNA Translation In Planta▿

    Science.gov (United States)

    Eskelin, Katri; Hafrén, Anders; Rantalainen, Kimmo I.; Mäkinen, Kristiina

    2011-01-01

    Viral protein genome-linked (VPg) plays a central role in several stages of potyvirus infection. This study sought to answer questions about the role of Potato virus A (PVA; genus Potyvirus) VPg in viral and host RNA expression. When expressed in Nicotiana benthamiana leaves in trans, a dual role of VPg in translation is observed. It repressed the expression of monocistronic luciferase (luc) mRNA and simultaneously induced a significant upregulation in the expression of both replicating and nonreplicating PVA RNAs. This enhanced viral gene expression was due at least to the 5′ untranslated region (UTR) of PVA RNA, eukaryotic initiation factors 4E and iso 4E [eIF4E/eIF(iso)4E], and the presence of a sufficient amount of VPg. Coexpression of VPg with viral RNA increased the viral RNA amount, which was not the case with the monocistronic mRNA. Both mutations at certain lysine residues in PVA VPg and eIF4E/eIF(iso)4E depletion reduced its ability to upregulate the viral RNA expression. These modifications were also involved in VPg-mediated downregulation of monocistronic luc expression. These results suggest that VPg can titrate eIF4Es from capped monocistronic RNAs. Because VPg-mediated enhancement of viral gene expression required eIF4Es, it is possible that VPg directs eIF4Es to promote viral RNA expression. From this study it is evident that VPg can serve as a specific regulator of PVA expression by boosting the viral RNA amounts as well as the accumulation of viral translation products. Such a mechanism could function to protect viral RNA from being degraded and to secure efficient production of coat protein (CP) for virion formation. PMID:21697470

  15. Advances in RNA interference technology and its impact on nutritional improvement, disease and insect control in plants.

    Science.gov (United States)

    Katoch, Rajan; Thakur, Neelam

    2013-03-01

    This review highlights the advances in the knowledge of RNA interference (RNAi) and discusses recent progress on the functionality of different components RNAi machinery operating in the organisms. The silencing of genes by RNA interference has become the technology of choice for investigation of gene functions in different organisms. The refinement in the knowledge of the endogenous RNAi pathways in plants along with the development of new strategies and applications for the improvement of nutritional value of important agricultural crops through suppression of genes in different plants have opened new vistas for nutritional security. The improvement in the nutritional status of the plants and reduction in the level of toxins or antinutrients was desired for long, but the available technology was not completely successful in achieving the tissue specific regulation of some genes. In the recent years, a number of economically important crop plants have been tested successfully for improving plant nutritional value through metabolic engineering using RNAi. The implications of this technology for crop improvement programs, including nutritional enrichment, reduction of antinutrients, disease, and insect control have been successfully tested in variety of crops with commercial considerations. The enhancement of the nutraceutical traits for the desired health benefits in common crop plants through manipulation of gene expression has been elaborated in this article. The tremendous potential with RNAi technology is expected to revolutionize the modern agriculture for meeting the growing challenges is discussed.

  16. MicroRNA-218 inhibits cell invasion and migration of pancreatic cancer via regulating ROBO1.

    Science.gov (United States)

    He, Hang; Hao, Si-Jie; Yao, Lie; Yang, Feng; Di, Yang; Li, Ji; Jiang, Yong-Jian; Jin, Chen; Fu, De-Liang

    2014-10-01

    miRNA-218 is a highlighted tumor suppressor and its underlying role in tumor progression is still unknown. Here, we restored the expression of miRNA-218 in pancreatic cancer to clarify the function and potent downstream pathway of miRNA-218. The expressions of both miRNA-218 and its potent target gene ROBO1 were revealed by RT-PCR and western blotting analysis. Transfection of miRNA-218 precursor mimics and luciferase assay were performed to elucidate the regulation mechanism between miRNA-218 and ROBO1. Cells, stably expressing miRNA-218 followed by forced expression of mutant ROBO1, were established through co-transfections of both lentivirus vector and plasmid vector. The cell migration and invasion abilities were evaluated by migration assay and invasion assay respectively. An increased expression of ROBO1 was revealed in cell BxPC-3-LN compared with cell BxPC-3. Elevated expression of miRNA-218 would suppress the expression of ROBO1 via complementary binding to a specific region within 3'UTR of ROBO1 mRNA (sites 971-978) in pancreatic cancer cells. Stably restoring the expression of miRNA-218 in pancreatic cancer significantly downregulated the expression of ROBO1 and effectively inhibited cell migration and invasion. Forced expression of mutant ROBO1 could reverse the repression effects of miRNA-218 on cell migration and invasion. Consequently, miRNA-218 acted as a tumor suppressor in pancreatic cancer by inhibiting cell invasion and migration. ROBO1 was a functional target of miRNA-218's downstream pathway involving in cell invasion and migration of pancreatic cancer.

  17. MicroRNA-144 inhibits hepatocellular carcinoma cell proliferation

    Indian Academy of Sciences (India)

    MiR-144 was shown to besignificantly down-regulated in HCC tissues and cell lines. Subsequently, overexpression of miR-144 was transfectedinto HCC cell lines so as to investigate its biological function, including MTT, colony formation, and transwell assays.Gain of function assay revealed miR-144 remarkably inhibited ...

  18. Efficient nanoparticle mediated sustained RNA interference in human primary endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Mukerjee, Anindita; Shankardas, Jwalitha; Ranjan, Amalendu P; Vishwanatha, Jamboor K, E-mail: Jamboor.vishwanatha@unthsc.edu [Department of Molecular Biology and Immunology and Institute for Cancer Research, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2011-11-04

    Endothelium forms an important target for drug and/or gene therapy since endothelial cells play critical roles in angiogenesis and vascular functions and are associated with various pathophysiological conditions. RNA mediated gene silencing presents a new therapeutic approach to overcome many such diseases, but the major challenge of such an approach is to ensure minimal toxicity and effective transfection efficiency of short hairpin RNA (shRNA) to primary endothelial cells. In the present study, we formulated shAnnexin A2 loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles which produced intracellular small interfering RNA (siRNA) against Annexin A2 and brought about the downregulation of Annexin A2. The per cent encapsulation of the plasmid within the nanoparticle was found to be 57.65%. We compared our nanoparticle based transfections with Lipofectamine mediated transfection, and our studies show that nanoparticle based transfection efficiency is very high ({approx}97%) and is more sustained compared to conventional Lipofectamine mediated transfections in primary retinal microvascular endothelial cells and human cancer cell lines. Our findings also show that the shAnnexin A2 loaded PLGA nanoparticles had minimal toxicity with almost 95% of cells being viable 24 h post-transfection while Lipofectamine based transfections resulted in only 30% viable cells. Therefore, PLGA nanoparticle based transfection may be used for efficient siRNA transfection to human primary endothelial and cancer cells. This may serve as a potential adjuvant treatment option for diseases such as diabetic retinopathy, retinopathy of prematurity and age related macular degeneration besides various cancers.

  19. Efficient nanoparticle mediated sustained RNA interference in human primary endothelial cells

    Science.gov (United States)

    Mukerjee, Anindita; Shankardas, Jwalitha; Ranjan, Amalendu P.; Vishwanatha, Jamboor K.

    2011-11-01

    Endothelium forms an important target for drug and/or gene therapy since endothelial cells play critical roles in angiogenesis and vascular functions and are associated with various pathophysiological conditions. RNA mediated gene silencing presents a new therapeutic approach to overcome many such diseases, but the major challenge of such an approach is to ensure minimal toxicity and effective transfection efficiency of short hairpin RNA (shRNA) to primary endothelial cells. In the present study, we formulated shAnnexin A2 loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles which produced intracellular small interfering RNA (siRNA) against Annexin A2 and brought about the downregulation of Annexin A2. The per cent encapsulation of the plasmid within the nanoparticle was found to be 57.65%. We compared our nanoparticle based transfections with Lipofectamine mediated transfection, and our studies show that nanoparticle based transfection efficiency is very high (~97%) and is more sustained compared to conventional Lipofectamine mediated transfections in primary retinal microvascular endothelial cells and human cancer cell lines. Our findings also show that the shAnnexin A2 loaded PLGA nanoparticles had minimal toxicity with almost 95% of cells being viable 24 h post-transfection while Lipofectamine based transfections resulted in only 30% viable cells. Therefore, PLGA nanoparticle based transfection may be used for efficient siRNA transfection to human primary endothelial and cancer cells. This may serve as a potential adjuvant treatment option for diseases such as diabetic retinopathy, retinopathy of prematurity and age related macular degeneration besides various cancers.

  20. Efficient nanoparticle mediated sustained RNA interference in human primary endothelial cells

    International Nuclear Information System (INIS)

    Mukerjee, Anindita; Shankardas, Jwalitha; Ranjan, Amalendu P; Vishwanatha, Jamboor K

    2011-01-01

    Endothelium forms an important target for drug and/or gene therapy since endothelial cells play critical roles in angiogenesis and vascular functions and are associated with various pathophysiological conditions. RNA mediated gene silencing presents a new therapeutic approach to overcome many such diseases, but the major challenge of such an approach is to ensure minimal toxicity and effective transfection efficiency of short hairpin RNA (shRNA) to primary endothelial cells. In the present study, we formulated shAnnexin A2 loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles which produced intracellular small interfering RNA (siRNA) against Annexin A2 and brought about the downregulation of Annexin A2. The per cent encapsulation of the plasmid within the nanoparticle was found to be 57.65%. We compared our nanoparticle based transfections with Lipofectamine mediated transfection, and our studies show that nanoparticle based transfection efficiency is very high (∼97%) and is more sustained compared to conventional Lipofectamine mediated transfections in primary retinal microvascular endothelial cells and human cancer cell lines. Our findings also show that the shAnnexin A2 loaded PLGA nanoparticles had minimal toxicity with almost 95% of cells being viable 24 h post-transfection while Lipofectamine based transfections resulted in only 30% viable cells. Therefore, PLGA nanoparticle based transfection may be used for efficient siRNA transfection to human primary endothelial and cancer cells. This may serve as a potential adjuvant treatment option for diseases such as diabetic retinopathy, retinopathy of prematurity and age related macular degeneration besides various cancers.

  1. RNA Interference Screen to Identify Pathways That Enhance or Reduce Nonviral Gene Transfer During Lipofection

    OpenAIRE

    Barker, Gregory A; Diamond, Scott L

    2008-01-01

    Some barriers to DNA lipofection are well characterized; however, there is as yet no method of finding unknown pathways that impact the process. A druggable genome small-interfering RNA (siRNA) screen against 5,520 genes was tested for its effect on lipofection of human aortic endothelial cells (HAECs). We found 130 gene targets which, when silenced by pooled siRNAs (three siRNAs per gene), resulted in enhanced luminescence after lipofection (86 gene targets showed reduced expression). In con...

  2. RNA interference of acetylcholinesterase in the Asian citrus psyllid, Diaphorina citri, increases its susceptibility to carbamate and organophosphate insecticides.

    Science.gov (United States)

    Kishk, Abdelaziz; Hijaz, Faraj; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Killiny, Nabil

    2017-11-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Lividae) transmits the Candidatus Liberibacter asiaticus, which causes citrus greening disease or Huanglongbing, (HLB). To date, there is no efficient cure for HLB disease and the control of D. citri using insecticides became the most important tools for the management of HLB. However, the extensive use of insecticides could increase D. citri resistance to these insecticides. The objective of this study was to investigate the effect of RNA interference of acetylcholinesterase (AChE) on the mortality and susceptibility of D. citri to the four major insecticides used in Florida. In this study, we used a consensus sequence derived from the two AChE genes and cholinesterase 2-like (ChE-2-like) gene to target all of the three genes. Treatment with dsRNA-AChE increased the mortality percentages of both nymphs and adults of D. citri. The mortality percentage increased with the increase in the concentration of applied dsRNA-AChE, and the highest mortality (> 60%) was observed at the highest applied concentration (125ng/μl). Treatments of nymphs or adults with dsRNA-AChE down-regulated the expression of the three targeted genes of D. citri. Silencing of AChE and ChE in D. citri nymphs increased the susceptibility of emerged adults to chlorpyrifos and carbaryl, which act as AChE inhibitors. However, treatment with dsRNA-AChE did not increase the susceptibility of emerged adults to imidacloprid, which acts as an agonist of nicotinic acetylcholine receptors. In the same manner, treatment of adults with dsRNA-AChE increased their susceptibility to chlorpyrifos and carbaryl, but did not affect their susceptibility to imidacloprid. The ANOVA did not show any significant increase in susceptibility of D. citri adults to fenpropathrin after treatment with dsRNA-AChE, either as nymphs or as adults. However, simple linear regression showed that treatment with dsRNA-AChE increased D. citri susceptibility to fenpropathrin

  3. Comparison of dengue virus type 2-specific small RNAs from RNA interference-competent and -incompetent mosquito cells.

    Directory of Open Access Journals (Sweden)

    Jaclyn C Scott

    2010-10-01

    Full Text Available The exogenous RNA interference (RNAi pathway is an important antiviral defense against arboviruses in mosquitoes, and virus-specific small interfering (siRNAs are key components of this pathway. Understanding the biogenesis of siRNAs in mosquitoes could have important ramifications in using RNAi to control arbovirus transmission. Using deep sequencing technology, we characterized dengue virus type 2 (DENV2-specific small RNAs produced during infection of Aedes aegypti mosquitoes and A. aegypti Aag2 cell cultures and compared them to those produced in the C6/36 Aedes albopictus cell line. We show that the size and mixed polarity of virus-specific small RNAs from DENV-infected A. aegypti cells indicate that they are products of Dicer-2 (Dcr2 cleavage of long dsRNA, whereas C6/36 cells generate DENV2-specific small RNAs that are longer and predominantly positive polarity, suggesting that they originate from a different small RNA pathway. Examination of virus-specific small RNAs after infection of the two mosquito cell lines with the insect-only flavivirus cell fusing agent virus (CFAV corroborated these findings. An in vitro assay also showed that Aag2 A. aegypti cells are capable of siRNA production, while C6/36 A. albopictus cells exhibit inefficient Dcr2 cleavage of long dsRNA. Defective expression or function of Dcr2, the key initiator of the RNAi pathway, might explain the comparatively robust growth of arthropod-borne viruses in the C6/36 cell line, which has been used frequently as a surrogate for studying molecular interactions between arboviruses and cells of their mosquito hosts.

  4. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Directory of Open Access Journals (Sweden)

    Zongli eHu

    2015-01-01

    Full Text Available Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi technology to partially silence three different genes (FOW2, FRP1 and OPR in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  5. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Science.gov (United States)

    Hu, Zongli; Parekh, Urvi; Maruta, Natsumi; Trusov, Yuri; Botella, Jimmy

    2015-01-01

    Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi) technology to partially silence three different genes (FOW2, FRP1 and OPR) in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  6. In Vivo RNA Interference Screening Identifies a Leukemia-Specific Dependence on Integrin Beta 3 Signaling

    Science.gov (United States)

    Miller, Peter G.; Al-Shahrour, Fatima; Hartwell, Kimberly A.; Chu, Lisa P.; Järås, Marcus; Puram, Rishi V.; Puissant, Alexandre; Callahan, Kevin P.; Ashton, John; McConkey, Marie E.; Poveromo, Luke P.; Cowley, Glenn S.; Kharas, Michael G.; Labelle, Myriam; Shterental, Sebastian; Fujisaki, Joji; Silberstein, Lev; Alexe, Gabriela; Al-Hajj, Muhammad A.; Shelton, Christopher A.; Armstrong, Scott A.; Root, David E.; Scadden, David T.; Hynes, Richard O.; Mukherjee, Siddhartha; Stegmaier, Kimberly; Jordan, Craig T.; Ebert, Benjamin L.

    2013-01-01

    SUMMARY We used an in vivo short hairpin RNA (shRNA) screening approach to identify genes that are essential for MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is essential for murine leukemia cells in vivo, and for human leukemia cells in xenotransplantation studies. In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation via the intracellular kinase, Syk. In contrast, loss of Itgb3 in normal HSPCs did not affect engraftment, reconstitution, or differentiation. Finally, we confirmed that Itgb3 is dispensable for normal hematopoiesis and required for leukemogenesis using an Itgb3 knockout mouse model. Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML. PMID:23770013

  7. Knock down of the myostatin gene by RNA interference increased body weight in chicken.

    Science.gov (United States)

    Bhattacharya, T K; Shukla, R; Chatterjee, R N; Dushyanth, K

    2017-01-10

    Myostatin is a negative regulator of muscular growth in poultry and other animals. Of several approaches, knocking down the negative regulator is an important aspect to augment muscular growth in chicken. Knock down of myostatin gene has been performed by shRNA acting against the expression of gene in animals. Two methods of knock down of gene in chicken such as embryo manipulation and sperm mediated method have been performed. The hatching percentage in embryo manipulation and sperm mediated method of knock down was 58.0 and 41.5%, respectively. The shRNA in knock down chicken enhanced body weight at 6 weeks by 26.9%. The dressing percentage and serum biochemical parameters such as SGPT and alkaline phosphatase differed significantly (Pknock down and control birds. It is concluded that knocking down the myostatin gene successfully augmented growth in chicken. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Regulation of gene expression in neuronal tissue by RNA interference and editing

    DEFF Research Database (Denmark)

    Venø, Morten Trillingsgaard

    No tissue in the mammalian organism is more complex than the brain. This complexity is in part the result of precise timing and interplay of a large number mechanisms modulating gene expression post-transcriptionally. Fine-tuning mechanisms such as A-to-I editing of RNA transcripts and regulation...... mediated by microRNAs are crucial for the correct function of the mammalian brain. We are addressing A-to-I editing and regulation by microRNAs with spatio-temporal resolution in the embryonic porcine brain by Solexa sequencing of microRNAs and 454 sequencing of edited neuronal messenger RNAs, resulting...... in detailed data of both of these fine-tuning mechanisms in the embryonic development of the pig. Editing levels of transcripts examined are generally seen to increase through development, in agreement with editing of specific microRNA also examined in the Solexa sequencing study. Three studies examining...

  9. Persistent interferon transgene expression by RNA interference-mediated silencing of interferon receptors.

    Science.gov (United States)

    Takahashi, Yuki; Vikman, Elin; Nishikawa, Makiya; Ando, Mitsuru; Watanabe, Yoshihiko; Takakura, Yoshinobu

    2010-09-01

    The in vivo half-life of interferons (IFNs) is very short, and its extension would produce a better therapeutic outcome in IFN-based therapy. Delivery of IFN genes is one solution for providing a sustained supply. IFNs have a variety of functions, including the suppression of transgene expression, through interaction with IFN receptors (IFNRs). This suppression could prevent IFNs from being expressed from vectors delivered. Silencing the expression of IFNAR and IFNGR, the receptors for type I and II IFNs, respectively, in cells expressing IFNs may prolong transgene expression of IFNs. Mouse melanoma B16-BL6 cells or mouse liver were selected as a site expressing IFNs (not a target for IFN gene therapy) and IFN-expressing plasmid DNA was delivered with or without small interfering RNA (siRNA) targeting IFNRs. Transfection of B16-BL6 cells with siRNA targeting IFNAR1 subunit (IFNAR1) resulted in the reduced expression of IFNAR on the cell surface. This silencing significantly increased the IFN-beta production in cells that were transfected with IFN-beta-expressing plasmid DNA. Similar results were obtained with the combination of IFN-gamma and IFNGR. Co-injection of IFN-beta-expressing plasmid DNA with siRNA targeting IFNAR1 into mice resulted in sustained plasma concentration of IFN-beta. These results provide experimental evidence that the RNAi-mediated silencing of IFNRs in cells expressing IFN, such as hepatocytes, is an effective approach for improving transgene expression of IFNs when their therapeutic target comprises cells other than those expressing IFNs.

  10. Cognitive inhibition of number/length interference in a Piaget-like task: evidence by combining ERP and MEG.

    Science.gov (United States)

    Joliot, Marc; Leroux, Gaëlle; Dubal, Stéphanie; Tzourio-Mazoyer, Nathalie; Houdé, Olivier; Mazoyer, Bernard; Petit, Laurent

    2009-08-01

    We combined event-related potential (ERP) and magnetoencephalography (MEG) acquisition and analysis to investigate the electrophysiological markers of the inhibitory processes involved in the number/length interference in a Piaget-like numerical task. Eleven healthy subjects performed four gradually interfering conditions with the heuristic "length equals number" to be inhibited. Low resolution tomography reconstruction was performed on the combined grand averaged electromagnetic data at the early (N1, P1) and late (P2, N2, P3(early) and P3(late)) latencies. Every condition was analyzed at both scalp and regional brain levels. The inhibitory processes were visible on the late components of the electromagnetic brain activity. A right P2-related frontal orbital activation reflected the change of strategy in the inhibitory processes. N2-related SMA/cingulate activation revealed the first occurrence of the stimuli processing to be inhibited. Both P3 components revealed the working memory processes operating in a medial temporal complex and the mental imagery processes subtended by the precuneus. Simultaneous ERP and MEG signal acquisition and analysis allowed to describe the spatiotemporal patterns of neural networks involved in the inhibition of the "length equals number" interference. Combining ERP and MEG ensured a sensitivity which could be reached previously only through invasive intracortical recordings.

  11. Inhibition of Escherichia coli precursor-16S rRNA processing by mouse intestinal contents

    DEFF Research Database (Denmark)

    Licht, Tine Rask; Tolker-Nielsen, Tim; Holmstrøm, Kim

    1999-01-01

    . We have applied fluorescence in situ hybridization of pre-16S rRNA to Escherichia coli cells growing in vitro in extracts from two different compartments of the mouse intestine: the caecal mucus layer, where E. coli grew rapidly, and the contents of the caecum, which supported much slower bacterial...... content of pre-16S rRNA than cultures of the same strain growing rapidly in rich media. We present results suggesting that the mouse intestinal contents contain an agent that inhibits the growth of E. coli by disturbing its ability to process pre-16S rRNA....

  12. Chronic Cardiac-Targeted RNA Interference for the Treatment of Heart Failure Restores Cardiac Function and Reduces Pathological Hypertrophy

    Science.gov (United States)

    Suckau, Lennart; Fechner, Henry; Chemaly, Elie; Krohn, Stefanie; Hadri, Lahouaria; Kockskämper, Jens; Westermann, Dirk; Bisping, Egbert; Ly, Hung; Wang, Xiaomin; Kawase, Yoshiaki; Chen, Jiqiu; Liang, Lifan; Sipo, Isaac; Vetter, Roland; Weger, Stefan; Kurreck, Jens; Erdmann, Volker; Tschope, Carsten; Pieske, Burkert; Lebeche, Djamel; Schultheiss, Heinz-Peter; Hajjar, Roger J.; Poller, Wolfgang Ch.

    2009-01-01

    Background RNA interference (RNAi) has the potential to be a novel therapeutic strategy in diverse areas of medicine. We report on targeted RNAi for the treatment of heart failure (HF), an important disorder in humans resulting from multiple etiologies. Successful treatment of HF is demonstrated in a rat model of transaortic banding by RNAi targeting of phospholamban (PLB), a key regulator of cardiac Ca2+ homeostasis. Whereas gene therapy rests on recombinant protein expression as its basic principle, RNAi therapy employs regulatory RNAs to achieve its effect. Methods and Results We describe structural requirements to obtain high RNAi activity from adenoviral (AdV) and adeno-associated virus (AAV9) vectors and show that an AdV short hairpin RNA vector (AdV-shRNA) silenced PLB in cardiomyocytes (NRCMs) and improved hemodynamics in HF rats 1 month after aortic root injection. For simplified long-term therapy we developed a dimeric cardiotropic AAV vector (rAAV9-shPLB) delivering RNAi activity to the heart via intravenous injection. Cardiac PLB protein was reduced to 25% and SERCA2a suppression in the HF groups was rescued. In contrast to traditional vectors rAAV9 shows high affinity for myocardium, but low affinity for liver and other organs. rAAV9-shPLB therapy restored diastolic (LVEDP, dp/dtmin, Tau) and systolic (fractional shortening) functional parameters to normal range. The massive cardiac dilation was normalized and the cardiac hypertrophy, cardiomyocyte diameter and cardiac fibrosis significantly reduced. Importantly, there was no evidence of microRNA deregulation or hepatotoxicity during these RNAi therapies. Conclusion Our data show, for the first time, high efficacy of an RNAi therapeutic strategy in a cardiac disease. PMID:19237664

  13. Functional analysis of the cathepsin-like cysteine protease genes in adult Brugia malayi using RNA interference.

    Directory of Open Access Journals (Sweden)

    Louise Ford

    Full Text Available Cathepsin-like enzymes have been identified as potential targets for drug or vaccine development in many parasites, as their functions appear to be essential in a variety of important biological processes within the host, such as molting, cuticle remodeling, embryogenesis, feeding and immune evasion. Functional analysis of Caenorhabditis elegans cathepsin L (Ce-cpl-1 and cathepsin Z (Ce-cpz-1 has established that both genes are required for early embryogenesis, with Ce-cpl-1 having a role in regulating in part the processing of yolk proteins. Ce-cpz-1 also has an important role during molting.RNA interference assays have allowed us to verify whether the functions of the orthologous filarial genes in Brugia malayi adult female worms are similar. Treatment of B. malayi adult female worms with Bm-cpl-1, Bm-cpl-5, which belong to group Ia of the filarial cpl gene family, or Bm-cpz-1 dsRNA resulted in decreased numbers of secreted microfilariae in vitro. In addition, analysis of the intrauterine progeny of the Bm-cpl-5 or Bm-cpl Pro dsRNA- and siRNA-treated worms revealed a clear disruption in the process of embryogenesis resulting in structural abnormalities in embryos and a varied differential development of embryonic stages.Our studies suggest that these filarial cathepsin-like cysteine proteases are likely to be functional orthologs of the C. elegans genes. This functional conservation may thus allow for a more thorough investigation of their distinct functions and their development as potential drug targets.

  14. RNA interference-mediated silencing of speckle-type POZ protein promotes apoptosis of renal cell cancer cells.

    Science.gov (United States)

    Liu, Xiaoxia; Sun, Guiling; Sun, Xiuju

    2016-01-01

    This study aimed to investigate the effects of silencing the speckle-type POZ protein (SPOP) gene on renal cell cancer (RCC) cells and to explore its possible mechanism. The A498 and ACHN RCC cells were transfected with small interference RNA (siRNA)-SPOP by lipofection methods. The silencing efficiency was monitored by quantitative real-time polymerase chain reaction and Western blot. The effects of SPOP silencing on cell apoptosis, cell viability, colony formation ability, cell migration ability, and chemosensitivity to Sorafenib were assessed by flow cytometry, an MTT assay, a colony formation assay, a trans-well migration assay, and a CCK-8 assay, respectively. Its effects on the expression of several cytokines were determined by a protein microarray. Relevant signaling pathways were also analyzed. Compared with the control group, the cell apoptosis rate was significantly higher; the cell viability, the colony formation, and migration ability were significantly decreased in the siRNA-SPOP group. The protein microarray screening showed that the expression of vascular endothelial growth factor receptor, matrix metallopeptidase-9, vascular cell adhesion molecule-1, and stromal cell-derived factor-1 in the siRNA group was significantly decreased and that the expression of granulocyte-macrophage colony-stimulating factor and E-cadherin was significantly increased (Pmatrix organization signal pathway. SPOP gene silencing induced cell apoptosis, decreased cell viability, colony formation, and migration ability, and elevated the drug sensitivity in the RCC cells. A possible mechanism is that silencing SPOP induces the differential expression of E-cadherin, vascular endothelial growth factor receptor, matrix metallopeptidase-9, and vascular cell adhesion molecule, which are related to the integrin-mediated cell surface interactions and extracellular matrix organization signaling pathway.

  15. A viral suppressor protein inhibits host RNA silencing by hooking up with Argonautes

    KAUST Repository

    Jin, Hailing; Zhu, Jian-Kang

    2010-01-01

    RNA viruses are particularly vulnerable to RNAi-based defenses in the host, and thus have evolved specific proteins, known as viral suppressors of RNA silencing (VSRs), as a counterdefense. In this issue of Genes & Development, Azevedo and colleagues (pp. 904-915) discovered that P38, the VSR of Turnip crinkle virus, uses its glycine/tryptophane (GW) motifs as an ARGONAUTE (AGO) hook to attract and disarm the host's essential effector of RNA silencing. Several GW motif-containing cellular proteins are known to be important partners of AGOs in RNA silencing effector complexes in yeast, plants, and animals. The GW motif appears to be a versatile and effective tool for regulating the activities of RNA silencing pathways, and the use of GW mimicry to compete for and inhibit host AGOs may be a strategy used by many pathogens to counteract host RNAi-based defenses. © 2010 by Cold Spring Harbor Laboratory Press.

  16. A viral suppressor protein inhibits host RNA silencing by hooking up with Argonautes

    KAUST Repository

    Jin, Hailing

    2010-05-01

    RNA viruses are particularly vulnerable to RNAi-based defenses in the host, and thus have evolved specific proteins, known as viral suppressors of RNA silencing (VSRs), as a counterdefense. In this issue of Genes & Development, Azevedo and colleagues (pp. 904-915) discovered that P38, the VSR of Turnip crinkle virus, uses its glycine/tryptophane (GW) motifs as an ARGONAUTE (AGO) hook to attract and disarm the host\\'s essential effector of RNA silencing. Several GW motif-containing cellular proteins are known to be important partners of AGOs in RNA silencing effector complexes in yeast, plants, and animals. The GW motif appears to be a versatile and effective tool for regulating the activities of RNA silencing pathways, and the use of GW mimicry to compete for and inhibit host AGOs may be a strategy used by many pathogens to counteract host RNAi-based defenses. © 2010 by Cold Spring Harbor Laboratory Press.

  17. Enhanced Eyeblink Conditioning in Behaviorally Inhibited Individuals is Disrupted by Proactive Interference Following US Alone Pre-exposures.

    Science.gov (United States)

    Allen, Michael Todd; Miller, Daniel P

    2016-01-01

    Anxiety vulnerable individuals exhibit enhanced acquisition of conditioned eyeblinks as well as enhanced proactive interference from conditioned stimulus (CS) or unconditioned stimulus (US) alone pre-exposures (Holloway et al., 2012). US alone pre-exposures disrupt subsequent conditioned response (CR) acquisition to CS-US paired trials as compared to context pre-exposure controls. While Holloway et al. (2012) reported enhanced acquisition in high trait anxiety individuals in the context condition, anxiety vulnerability effects were not reported for the US alone pre-exposure group. It appears from the published data that there were no differences between high and low anxiety individuals in the US alone condition. In the work reported here, we sought to extend the findings of enhanced proactive interference with US alone pre-exposures to determine if the enhanced conditioning was disrupted by proactive interference procedures. We also were interested in the spontaneous eyeblinks during the pre-exposure phase of training. We categorized individuals as anxiety vulnerability or non-vulnerable individuals based scores on the Adult Measure of Behavioral Inhibition (AMBI). Sixty-six participants received 60 trials consisting of 30 US alone or context alone pre-exposures followed by 30 CS-US trials. US alone pre-exposures not only disrupted CR acquisition overall, but behaviorally inhibited (BI) individuals exhibited enhanced proactive interference as compared to non-inhibited (NI) individuals. In addition, US alone pre-exposures disrupted the enhanced acquisition observed in BI individuals as compared to NI individuals following context alone pre-exposures. Differences were also found in rates of spontaneous eyeblinks between BI and NI individuals during context pre-exposure. Our findings will be discussed in the light of the neural substrates of eyeblink conditioning as well as possible factors such as hypervigilance in the amygdala and hippocampal systems, and possible

  18. A loss of function analysis of host factors influencing Vaccinia virus replication by RNA interference.

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    Philippa M Beard

    Full Text Available Vaccinia virus (VACV is a large, cytoplasmic, double-stranded DNA virus that requires complex interactions with host proteins in order to replicate. To explore these interactions a functional high throughput small interfering RNA (siRNA screen targeting 6719 druggable cellular genes was undertaken to identify host factors (HF influencing the replication and spread of an eGFP-tagged VACV. The experimental design incorporated a low multiplicity of infection, thereby enhancing detection of cellular proteins involved in cell-to-cell spread of VACV. The screen revealed 153 pro- and 149 anti-viral HFs that strongly influenced VACV replication. These HFs were investigated further by comparisons with transcriptional profiling data sets and HFs identified in RNAi screens of other viruses. In addition, functional and pathway analysis of the entire screen was carried out to highlight cellular mechanisms involved in VACV replication. This revealed, as anticipated, that many pro-viral HFs are involved in translation of mRNA and, unexpectedly, suggested that a range of proteins involved in cellular transcriptional processes and several DNA repair pathways possess anti-viral activity. Multiple components of the AMPK complex were found to act as pro-viral HFs, while several septins, a group of highly conserved GTP binding proteins with a role in sequestering intracellular bacteria, were identified as strong anti-viral VACV HFs. This screen has identified novel and previously unexplored roles for cellular factors in poxvirus replication. This advancement in our understanding of the VACV life cycle provides a reliable knowledge base for the improvement of poxvirus-based vaccine vectors and development of anti-viral theraputics.

  19. Zinc Salts Block Hepatitis E Virus Replication by Inhibiting the Activity of Viral RNA-Dependent RNA Polymerase.

    Science.gov (United States)

    Kaushik, Nidhi; Subramani, Chandru; Anang, Saumya; Muthumohan, Rajagopalan; Shalimar; Nayak, Baibaswata; Ranjith-Kumar, C T; Surjit, Milan

    2017-11-01

    Hepatitis E virus (HEV) causes an acute, self-limiting hepatitis in healthy individuals and leads to chronic disease in immunocompromised individuals. HEV infection in pregnant women results in a more severe outcome, with the mortality rate going up to 30%. Though the virus usually causes sporadic infection, epidemics have been reported in developing and resource-starved countries. No specific antiviral exists against HEV. A combination of interferon and ribavirin therapy has been used to control the disease with some success. Zinc is an essential micronutrient that plays crucial roles in multiple cellular processes. Zinc salts are known to be effective in reducing infections caused by few viruses. Here, we investigated the effect of zinc salts on HEV replication. In a human hepatoma cell (Huh7) culture model, zinc salts inhibited the replication of genotype 1 (g-1) and g-3 HEV replicons and g-1 HEV infectious genomic RNA in a dose-dependent manner. Analysis of a replication-defective mutant of g-1 HEV genomic RNA under similar conditions ruled out the possibility of zinc salts acting on replication-independent processes. An ORF4-Huh7 cell line-based infection model of g-1 HEV further confirmed the above observations. Zinc salts did not show any effect on the entry of g-1 HEV into the host cell. Furthermore, our data reveal that zinc salts directly inhibit the activity of viral RNA-dependent RNA polymerase (RdRp), leading to inhibition of viral replication. Taken together, these studies unravel the ability of zinc salts in inhibiting HEV replication, suggesting their possible therapeutic value in controlling HEV infection. IMPORTANCE Hepatitis E virus (HEV) is a public health concern in resource-starved countries due to frequent outbreaks. It is also emerging as a health concern in developed countries owing to its ability to cause acute and chronic infection in organ transplant and immunocompromised individuals. Although antivirals such as ribavirin have been used

  20. Calcitriol Inhibits HCV Infection via Blockade of Activation of PPAR and Interference with Endoplasmic Reticulum-Associated Degradation

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    Yu-Min Lin

    2018-01-01

    Full Text Available Vitamin D has been identified as an innate anti-hepatitis C virus (HCV agent but the possible mechanisms for this issue remain unclear. Here, we clarified the mechanisms of calcitriol-mediated inhibition of HCV infection. Calcitriol partially inhibited HCV infection, nitric oxide (NO release and lipid accumulation in Huh7.5 human hepatoma cells via the activation of vitamin D receptor (VDR. When cells were pretreated with the activators of peroxisome proliferator-activated receptor (PPAR-α (Wy14643 and -γ (Ly171883, the calcitriol-mediated HCV suppression was reversed. Otherwise, three individual stimulators of PPAR-α/β/γ blocked the activation of VDR. PPAR-β (linoleic acid reversed the inhibition of NO release, whereas PPAR-γ (Ly171883 reversed the inhibitions of NO release and lipid accumulation in the presence of calcitriol. The calcitriol-mediated viral suppression, inhibition of NO release and activation of VDR were partially blocked by an inhibitor of endoplasmic reticulum-associated degradation (ERAD, kifunensine. Furthermore, calcitriol blocked the HCV-induced expressions of apolipoprotein J and 78 kDa glucose-regulated protein, which was restored by pretreatment of kifunensine. These results indicated that the calcitriol-mediated HCV suppression was associated with the activation of VDR, interference with ERAD process, as well as blockades of PPAR, lipid accumulation and nitrative stress.

  1. A broad range quorum sensing inhibitor working through sRNA inhibition

    DEFF Research Database (Denmark)

    Jakobsen, Tim H.; Warming, Anders N.; Vejborg, Rebecca M.

    2017-01-01

    that the repressing effect of ajoene on quorum sensing occurs by inhibition of small regulatory RNAs (sRNA) in P. aeruginosa as well as in Staphylococcus aureus, another important human pathogen that employs quorum sensing to control virulence gene expression. Using various reporter constructs, we found that ajoene......-spectrum compounds transcending the Gram negative-positive borderline....

  2. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations

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    Li eJiang

    2014-04-01

    Full Text Available RNA interference (RNAi knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F producing a slowly progressing cone/rod dystrophy (CORD. The late onset GCAP1(L151F-CORD mimics the dystrophy observed in human GCAP1-CORD patients. Subretinal injection of scAAV2/8 carrying shRNA expression cassettes specific for bovine or mouse GCAP1 showed strong expression at one week post-injection. In both allele-specific (GCAP1(Y99C-RP and nonallele-specific (GCAP1(L151F-CORD models of dominant retinal dystrophy, RNAi-mediated gene silencing enhanced photoreceptor survival, delayed onset of degeneration and improved visual function. Such results provide a proof of concept toward effective RNAi-based gene therapy mediated by scAAV2/8 for dominant retinal disease based on GCAP1 mutation. Further, nonallele-specific RNAi knockdown of GCAP1 may prove generally applicable toward the rescue of any human GCAP1-based dominant cone-rod dystrophy.

  3. Evaluation of metaphylactic RNA interference to prevent equine herpesvirus type 1 infection in experimental herpesvirus myeloencephalopathy in horses.

    Science.gov (United States)

    Perkins, Gillian A; Van de Walle, Gerlinde R; Pusterla, Nicola; Erb, Hollis N; Osterrieder, Nikolaus

    2013-02-01

    To evaluate metaphylactic RNA interference to prevent equine herpesvirus type 1 (EHV-1) infection in experimental herpesvirus myeloencephalopathy in horses and to determine whether horses infected with a neuropathogenic strain of the virus that develop equine herpesvirus myeloencephalopathy (EHM) have differences in viremia. 13 seronegative horses. EHV-1 strain Ab4 was administered intranasally on day 0, and small interfering RNAs (siRNAs [EHV-1 specific siRNAs {n = 7} or an irrelevant siRNA {6}]) were administered intranasally 24 hours before and 12, 24, 36, and 48 hours after infection. Physical and neurologic examinations, nasal swab specimens, and blood samples were collected for virus isolation and quantitative PCR assay. Data from the study were combined with data from a previous study of 14 horses. No significant difference was detected in clinical variables, viremia, or detection of EHV-1 in nasal swab specimens of horses treated with the EHV-1 targeted siRNAs (sigB3-siOri2) versus controls. No significant differences in viremia were detected between horses that developed EHM and those that did not. Administration of siRNAs targeted against EHV-1 around the time of EHV-1 infection was not protective with this experimental design. Horses infected with the neuropathogenic EHV-1 strain Ab4 that developed EHM did not have a more pronounced viremia.

  4. Low-weight polyethylenimine cross-linked 2-hydroxypopyl-ß-cyclodextrin and folic acid as an efficient and nontoxic siRNA carrier for gene silencing and tumor inhibition by VEGF siRNA

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    Li JM

    2013-06-01

    Full Text Available Jin-Ming Li, Yuan-Yuan Wang, Wei Zhang, Hua Su, Liang-Nian Ji, Zong-Wan Mao MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China Background: Targeted delivery of small interfering RNA (siRNA has been regarded as one of the most important technologies for the development of siRNA therapeutics. However, the need for safe and efficient delivery systems is a barrier to further development of RNA interference therapeutics. In this work, a nontoxic and efficient siRNA carrier delivery system of low molecular weight polyethyleneimine (PEI-600 Da cross-linked with 2-hydroxypopyl-β-cyclodextrin (HP-β-CD and folic acid (FA was synthesized for biomedical application. Methods: The siRNA carrier was prepared using a simple method and characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The siRNA carrier nanoparticles were characterized in terms of morphology, size and zeta potential, stability, efficiency of delivery, and gene silencing efficiency in vitro and in vivo. Results: The siRNA carrier was synthesized successfully. It showed good siRNA binding capacity and ability to protect siRNA. Further, the toxicity of the carrier measured in vitro and in vivo appeared to be negligible, probably because of degradation of the low molecular weight PEI and HP-β-CD in the cytosol. Flow cytometry and confocal microscopy confirmed that the FA receptor-mediated endocytosis of the FA-HP-β-CD-PEI/siRNA complexes was greater than that of the HP-β-CD-PEI/siRNA complexes in FA receptor-enriched HeLa cells. The FA-HP-β-CD-PEI/siRNA complexes also demonstrated excellent gene silencing efficiency in vitro (in the range of 90%, and reduced vascular endothelial growth factor (VEGF protein expression in the presence of 20% serum. FA-HP-β-CD-PEI/siRNA complexes administered via tail vein injection resulted in marked

  5. RNA binding protein RNPC1 inhibits breast cancer cells metastasis via activating STARD13-correlated ceRNA network.

    Science.gov (United States)

    Zhang, Zhiting; Guo, Qianqian; Zhang, Shufang; Xiang, Chenxi; Guo, Xinwei; Zhang, Feng; Gao, Lanlan; Ni, Haiwei; Xi, Tao; Zheng, Lufeng

    2018-05-07

    RNA binding proteins (RBPs) are pivotal post-transcriptional regulators. RNPC1, an RBP, acts as a tumor suppressor through binding and regulating the expression of target genes in cancer cells. This study disclosed that RNPC1 expression was positively correlated with breast cancer patients' relapse free and overall survival, and RNPC1suppressed breast cancer cells metastasis. Mechanistically, RNPC1 promoting a competing endogenous network (ceRNA) crosstalk between STARD13, CDH5, HOXD10, and HOXD1 (STARD13-correlated ceRNA network) that we previously confirmed in breast cancer cells through stabilizing the transcripts and thus facilitating the expression of these four genes in breast cancer cells. Furthermore, RNPC1 overexpression restrained the promotion of STARD13, CDH5, HOXD10, and HOXD1 knockdown on cell metastasis. Notably, RNPC1 expression was positively correlated with CDH5, HOXD1 and HOXD10 expression in breast cancer tissues, and attenuated adriamycin resistance. Taken together, these results identified that RNPC1 could inhibit breast cancer cells metastasis via promoting STARD13-correlated ceRNA network.

  6. Strengthening Triterpene Saponins Biosynthesis by Over-Expression of Farnesyl Pyrophosphate Synthase Gene and RNA Interference of Cycloartenol Synthase Gene in Panax notoginseng Cells

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    Yan Yang

    2017-04-01

    Full Text Available To conform to the multiple regulations of triterpene biosynthesis, the gene encoding farnesyl pyrophosphate synthase (FPS was transformed into Panax notoginseng (P. notoginseng cells in which RNA interference (RNAi of the cycloartenol synthase (CAS gene had been accomplished. Transgenic cell lines showed both higher expression levels of FPS and lower expression levels of CAS compared to the wild-type (WT cells. In the triterpene and phytosterol analysis, transgenic cell lines provided a higher accumulation of total triterpene saponins, and a lower amount of phytosterols in comparison with the WT cells. Compared with the cells in which RNAi of the CAS gene was achieved, the cells with simultaneously over-expressed FPS and silenced CAS showed higher triterpene contents. These results demonstrate that over-expression of FPS can break the rate-limiting reaction catalyzed by FPS in the triterpene saponins biosynthetic pathway; and inhibition of CAS expression can decrease the synthesis metabolic flux of the phytosterol branch. Thus, more precursors flow in the direction of triterpene synthesis, and ultimately promote the accumulation of P. notoginseng saponins. Meanwhile, silencing and over-expressing key enzyme genes simultaneously is more effective than just manipulating one gene in the regulation of saponin biosynthesis.

  7. Adenovirus delivered short hairpin RNA targeting a conserved site in the 5' non-translated region inhibits all four serotypes of dengue viruses.

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    Anil Babu Korrapati

    Full Text Available BACKGROUND: Dengue is a mosquito-borne viral disease caused by four closely related serotypes of Dengue viruses (DENVs. This disease whose symptoms range from mild fever to potentially fatal haemorrhagic fever and hypovolemic shock, threatens nearly half the global population. There is neither a preventive vaccine nor an effective antiviral therapy against dengue disease. The difference between severe and mild disease appears to be dependent on the viral load. Early diagnosis may enable timely therapeutic intervention to blunt disease severity by reducing the viral load. Harnessing the therapeutic potential of RNA interference (RNAi to attenuate DENV replication may offer one approach to dengue therapy. METHODOLOGY/PRINCIPAL FINDINGS: We screened the non-translated regions (NTRs of the RNA genomes of representative members of the four DENV serotypes for putative siRNA targets mapping to known transcription/translation regulatory elements. We identified a target site in the 5' NTR that maps to the 5' upstream AUG region, a highly conserved cis-acting element essential for viral replication. We used a replication-defective human adenovirus type 5 (AdV5 vector to deliver a short-hairpin RNA (shRNA targeting this site into cells. We show that this shRNA matures to the cognate siRNA and is able to inhibit effectively antigen secretion, viral RNA replication and infectious virus production by all four DENV serotypes. CONCLUSION/SIGNIFICANCE: The data demonstrate the feasibility of using AdV5-mediated delivery of shRNAs targeting conserved sites in the viral genome to achieve inhibition of all four DENV serotypes. This paves the way towards exploration of RNAi as a possible therapeutic strategy to curtail DENV infection.

  8. Development of functional genomic tools in trematodes: RNA interference and luciferase reporter gene activity in Fasciola hepatica.

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    Gabriel Rinaldi

    2008-07-01

    Full Text Available The growing availability of sequence information from diverse parasites through genomic and transcriptomic projects offer new opportunities for the identification of key mediators in the parasite-host interaction. Functional genomics approaches and methods for the manipulation of genes are essential tools for deciphering the roles of genes and to identify new intervention targets in parasites. Exciting advances in functional genomics for parasitic helminths are starting to occur, with transgene expression and RNA interference (RNAi reported in several species of nematodes, but the area is still in its infancy in flatworms, with reports in just three species. While advancing in model organisms, there is a need to rapidly extend these technologies to other parasites responsible for several chronic diseases of humans and cattle. In order to extend these approaches to less well studied parasitic worms, we developed a test method for the presence of a viable RNAi pathway by silencing the exogenous reporter gene, firefly luciferase (fLUC. We established the method in the human blood fluke Schistosoma mansoni and then confirmed its utility in the liver fluke Fasciola hepatica. We transformed newly excysted juveniles of F. hepatica by electroporation with mRNA of fLUC and three hours later were able to detect luciferase enzyme activity, concentrated mainly in the digestive ceca. Subsequently, we tested the presence of an active RNAi pathway in F. hepatica by knocking down the exogenous luciferase activity by introduction into the transformed parasites of double-stranded RNA (dsRNA specific for fLUC. In addition, we tested the RNAi pathway targeting an endogenous F. hepatica gene encoding leucine aminopeptidase (FhLAP, and observed a significant reduction in specific mRNA levels. In summary, these studies demonstrated the utility of RNAi targeting reporter fLUC as a reporter gene assay to establish the presence of an intact RNAi pathway in helminth

  9. PRMT5 restricts hepatitis B virus replication through epigenetic repression of covalently closed circular DNA transcription and interference with pregenomic RNA encapsidation.

    Science.gov (United States)

    Zhang, Wen; Chen, Jieliang; Wu, Min; Zhang, Xiaonan; Zhang, Min; Yue, Lei; Li, Yaming; Liu, Jiangxia; Li, Baocun; Shen, Fang; Wang, Yang; Bai, Lu; Protzer, Ulrike; Levrero, Massimo; Yuan, Zhenghong

    2017-08-01

    Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. The covalently closed circular DNA (cccDNA) minichromosome, which serves as the template for the transcription of viral RNAs, plays a key role in viral persistence. While accumulating evidence suggests that cccDNA transcription is regulated by epigenetic machinery, particularly the acetylation of cccDNA-bound histone 3 (H3) and H4, the potential contributions of histone methylation and related host factors remain obscure. Here, by screening a series of methyltransferases and demethylases, we identified protein arginine methyltransferase 5 (PRMT5) as an effective restrictor of HBV transcription and replication. In cell culture-based models for HBV infection and in liver tissues of patients with chronic HBV infection, we found that symmetric dimethylation of arginine 3 on H4 on cccDNA was a repressive marker of cccDNA transcription and was regulated by PRMT5 depending on its methyltransferase domain. Moreover, PRMT5-triggered symmetric dimethylation of arginine 3 on H4 on the cccDNA minichromosome involved an interaction with the HBV core protein and the Brg1-based human SWI/SNF chromatin remodeler, which resulted in down-regulation of the binding of RNA polymerase II to cccDNA. In addition to the inhibitory effect on cccDNA transcription, PRMT5 inhibited HBV core particle DNA production independently of its methyltransferase activity. Further study revealed that PRMT5 interfered with pregenomic RNA encapsidation by preventing its interaction with viral polymerase protein through binding to the reverse transcriptase-ribonuclease H region of polymerase, which is crucial for the polymerase-pregenomic RNA interaction. PRMT5 restricts HBV replication through a two-part mechanism including epigenetic suppression of cccDNA transcription and interference with pregenomic RNA encapsidation; these findings improve the understanding of epigenetic regulation of HBV transcription and host

  10. Short-hairpin RNA-mediated Heat shock protein 90 gene silencing inhibits human breast cancer cell growth in vitro and in vivo

    International Nuclear Information System (INIS)

    Zuo, Keqiang; Li, Dan; Pulli, Benjamin; Yu, Fei; Cai, Haidong; Yuan, Xueyu; Zhang, Xiaoping; Lv, Zhongwei

    2012-01-01

    Highlights: ► Hsp90 is over-expressed in human breast cancer. ► The shRNA-mediated gene silencing of Hsp90 resulted in inhibition of cell growth. ► Akt and NF-kB were down-regulation after transfection due to Hsp90 silencing. ► The tumor growth ratio was decline due to Hsp90 silencing. ► The PCNA expression was down-regulation due to Hsp90 silencing. -- Abstract: Hsp90 interacts with proteins that mediate signaling pathways involved in the regulation of essential processes such as proliferation, cell cycle control, angiogenesis and apoptosis. Hsp90 inhibition is therefore an attractive strategy for blocking abnormal pathways that are crucial for cancer cell growth. In the present study, the role of Hsp90 in human breast cancer MCF-7 cells was examined by stably silencing Hsp90 gene expression with an Hsp90-silencing vector (Hsp90-shRNA). RT-PCR and Western blot analyses showed that Hsp90-shRNA specifically and markedly down-regulated Hsp90 mRNA and protein expression. NF-kB and Akt protein levels were down-regulated in Hsp90-shRNA transfected cells, indicating that Hsp90 knockout caused a reduction of survival factors and induced apoptosis. Treatment with Hsp90-shRNA significantly increased apoptotic cell death and caused cell cycle arrest in the G1/S phase in MCF-7 cells, as shown by flow cytometry. Silencing of Hsp90 also reduced cell viability, as determined by MTT assay. In vivo experiments showed that MCF-7 cells stably transfected with Hsp90-shRNA grew slowly in nude mice as compared with control groups. In summary, the Hsp90-shRNA specifically silenced the Hsp90 gene, and inhibited MCF-7 cell growth in vitro and in vivo. Possible molecular mechanisms underlying the effects of Hsp90-shRNA include the degradation of Hsp90 breast cancer-related client proteins, the inhibition of survival signals and the upregulation of apoptotic pathways. shRNA-mediated interference may have potential therapeutic utility in human breast cancer.

  11. Small-molecule inhibition of HIV pre-mRNA splicing as a novel antiretroviral therapy to overcome drug resistance.

    Directory of Open Access Journals (Sweden)

    Nadia Bakkour

    2007-10-01

    Full Text Available The development of multidrug-resistant viruses compromises antiretroviral therapy efficacy and limits therapeutic options. Therefore, it is an ongoing task to identify new targets for antiretroviral therapy and to develop new drugs. Here, we show that an indole derivative (IDC16 that interferes with exonic splicing enhancer activity of the SR protein splicing factor SF2/ASF suppresses the production of key viral proteins, thereby compromising subsequent synthesis of full-length HIV-1 pre-mRNA and assembly of infectious particles. IDC16 inhibits replication of macrophage- and T cell-tropic laboratory strains, clinical isolates, and strains with high-level resistance to inhibitors of viral protease and reverse transcriptase. Importantly, drug treatment of primary blood cells did not alter splicing profiles of endogenous genes involved in cell cycle transition and apoptosis. Thus, human splicing factors represent novel and promising drug targets for the development of antiretroviral therapies, particularly for the inhibition of multidrug-resistant viruses.

  12. Folate-targeted amphiphilic cyclodextrin nanoparticles incorporating a fusogenic peptide deliver therapeutic siRNA and inhibit the invasive capacity of 3D prostate cancer tumours.

    Science.gov (United States)

    Evans, James C; Malhotra, Meenakshi; Sweeney, Katrina; Darcy, Raphael; Nelson, Colleen C; Hollier, Brett G; O'Driscoll, Caitriona M

    2017-10-30

    The main barrier to the development of an effective RNA interference (RNAi) therapy is the lack of a suitable delivery vector. Modified cyclodextrins have emerged in recent years for the delivery of siRNA. In the present study, a folate-targeted amphiphilic cyclodextrin was formulated using DSPE-PEG 5000 -folate to target prostate cancer cells. The fusogenic peptide GALA was included in the formulation to aid in the endosomal release of siRNA. Targeted nanoparticles were less than 200nm in size with a neutral surface charge. The complexes were able to bind siRNA and protect it from serum nucleases. Incubation with excess free folate resulted in a significant decrease in the uptake of targeted nanoparticles in LNCaP and PC3 cells, both of which have been reported to have differing pathways of folate uptake. There was a significant reduction in the therapeutic targets, ZEB1 and NRP1 at mRNA and protein level following treatment with targeted complexes. In preliminary functional assays using 3D spheroids, treatment of PC3 tumours with targeted complexes with ZEB1 and NRP1 siRNA resulted in more compact colonies relative to the untargeted controls and inhibited infiltration into the Matrigel™ layer. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Expression and RNA Interference of Ribosomal Protein L5 Gene in Nilaparvata lugens (Hemiptera: Delphacidae).

    Science.gov (United States)

    Zhu, Jiajun; Hao, Peiying; Lu, Chaofeng; Ma, Yan; Feng, Yalin; Yu, Xiaoping

    2017-05-01

    The ribosomal proteins play important roles in the growth and development of organisms. This study aimed to explore the function of NlRPL5 (GenBank KX379234), a ribosomal protein L5 gene, in the brown planthopper Nilaparvata lugens. The open reading frame of NlRPL5 was cloned from N. lugens based on a previous transcriptome analysis. The results revealed that the open reading frame of NlRPL5 is of 900 bp, encoding 299 amino acid residues. The reverse transcription quantitative PCR results suggested that the expression of NlRPL5 gene was stronger in gravid females, but was relatively low in nymphs, males, and newly emerged females. The expression level of NlRPL5 in the ovary was about twofolds of that in the head, thorax, or fat body. RNAi of dsNlRPL5 resulted in a significant reduction of mRNA levels, ∼50% decrease in comparison with the dsGFP control at day 6. Treatment of dsNlRPL5 significantly restricted the ovarian development, and decreased the number of eggs laid on the rice (Oryza sativa) plants. This study provided a new clue for further study on the function and regulation mechanism of NlRPL5 in N. lugens. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

  14. Gene interactions in the DNA damage-response pathway identified by genome-wide RNA-interference analysis of synthetic lethality

    NARCIS (Netherlands)

    van Haaften, Gijs; Vastenhouw, Nadine L; Nollen, Ellen A A; Plasterk, Ronald H A; Tijsterman, Marcel

    2004-01-01

    Here, we describe a systematic search for synthetic gene interactions in a multicellular organism, the nematode Caenorhabditis elegans. We established a high-throughput method to determine synthetic gene interactions by genome-wide RNA interference and identified genes that are required to protect

  15. Engineered disease resistance in cotton using RNA-interference to knock down cotton leaf curl kokhran virus-Burewala and cotton leaf curl Multan betasatellite

    Science.gov (United States)

    Cotton Leaf Curl virus Disease (CLCuD) has caused enormous losses in cotton (Gossypium hirsutum) production in Pakistan. RNA interference (RNAi) is an emerging technique that could knock out CLCuD by targeting different regions of the pathogen genome that are important for replication, transcription...

  16. Efficient Inhibition of wear debris-induced inflammation by locally delivered siRNA

    International Nuclear Information System (INIS)

    Peng Xiaochun; Tao Kun; Cheng Tao; Zhu Junfeng; Zhang Xianlong

    2008-01-01

    Aseptic loosening is the most common long-term complication of total joint replacement, which is associated with the generation of wear debris. The purpose of this study was to investigate the inhibitory effect of small interfering RNA (siRNA) targeting tumor necrosis factor-α (TNF-α) on wear debris-induced inflammation. A local delivery of lentivirus-mediated TNF-α siRNA into the modified murine air pouch, which was stimulated by polymethylmethacrylate (PMMA) particles, resulted in significant blockage of TNF-α both in mRNA and protein levels for up to 4 weeks. In addition, significant down-regulation of interleukin-1 (IL-1) and interleukin-6 (IL-6) was observed in TNF-α siRNA-treated pouches. The safety profile of gene therapy was proven by Bioluminescent assay and quantitative fluorescent flux. Histological analysis revealed less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) in TNF-α siRNA-treated pouches. These findings suggest that local delivery of TNF-α siRNA might be an excellent therapeutic candidate to inhibit particle-induced inflammation.

  17. Perivascular delivery of Notch 1 siRNA inhibits injury-induced arterial remodeling.

    Directory of Open Access Journals (Sweden)

    Eileen M Redmond

    Full Text Available To determine the efficacy of perivascular delivery of Notch 1 siRNA in preventing injury-induced arterial remodeling.Carotid artery ligation was performed to induce arterial remodeling. After 14 days, morphometric analysis confirmed increased vSMC growth and subsequent media thickening and neointimal formation. Laser capture microdissection, quantitative qRT-PCR and immunoblot analysis of medial tissue revealed a significant increase in Notch1 receptor and notch target gene, Hrt 1 and 2 expression in the injured vessels. Perivascular delivery of Notch 1 siRNA by pluronic gel inhibited the injury-induced increase in Notch 1 receptor and target gene expression when compared to scrambled siRNA controls while concomitantly reducing media thickening and neointimal formation to pre-injury, sham-operated levels. Selective Notch 1 knockdown also reversed the injury-induced inhibition of pro-apoptotic Bax expression while decreasing injury-induced anti-apoptotic Bcl-XL expression to sham-operated control levels. In parallel experiments, proliferative cyclin levels, as measured by PCNA expression, were reversed to sham-operated control levels following selective Notch 1 knockdown.These results suggest that injury-induced arterial remodeling can be successfully inhibited by localized perivascular delivery of Notch 1 siRNA.

  18. A Simple Retroelement Based Knock-Down System in Dictyostelium: Further Insights into RNA Interference Mechanisms.

    Science.gov (United States)

    Friedrich, Michael; Meier, Doreen; Schuster, Isabelle; Nellen, Wolfgang

    2015-01-01

    We have previously shown that the most abundant Dictyostelium discoideum retroelement DIRS-1 is suppressed by RNAi mechanisms. Here we provide evidence that both inverted terminal repeats have strong promoter activity and that bidirectional expression apparently generates a substrate for Dicer. A cassette containing the inverted terminal repeats and a fragment of a gene of interest was sufficient to activate the RNAi response, resulting in the generation of ~21 nt siRNAs, a reduction of mRNA and protein expression of the respective endogene. Surprisingly, no transitivity was observed on the endogene. This was in contrast to previous observations, where endogenous siRNAs caused spreading on an artificial transgene. Knock-down was successful on seven target genes that we examined. In three cases a phenotypic analysis proved the efficiency of the approach. One of the target genes was apparently essential because no knock-out could be obtained; the RNAi mediated knock-down, however, resulted in a very slow growing culture indicating a still viable reduction of gene expression. ADVANTAGES OF THE DIRS-1–RNAI SYSTEM: The knock-down system required a short DNA fragment (~400 bp) of the target gene as an initial trigger. Further siRNAs were generated by RdRPs since we have shown some siRNAs with a 5'-triphosphate group. Extrachromosomal vectors facilitate the procedure and allowed for molecular and phenotypic analysis within one week. The system provides an efficient and rapid method to reduce protein levels including those of essential genes.

  19. RNA interference-mediated silencing of speckle-type POZ protein promotes apoptosis of renal cell cancer cells

    Directory of Open Access Journals (Sweden)

    Liu X

    2016-04-01

    Full Text Available Xiaoxia Liu, Guiling Sun, Xiuju Sun Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, People’s Republic of China Abstract: This study aimed to investigate the effects of silencing the speckle-type POZ protein (SPOP gene on renal cell cancer (RCC cells and to explore its possible mechanism. The A498 and ACHN RCC cells were transfected with small interference RNA (siRNA-SPOP by lipofection methods. The silencing efficiency was monitored by quantitative real-time polymerase chain reaction and Western blot. The effects of SPOP silencing on cell apoptosis, cell viability, colony formation ability, cell migration ability, and chemosensitivity to Sorafenib were assessed by flow cytometry, an MTT assay, a colony formation assay, a trans-well migration assay, and a CCK-8 assay, respectively. Its effects on the expression of several cytokines were determined by a protein microarray. Relevant signaling pathways were also analyzed. Compared with the control group, the cell apoptosis rate was significantly higher; the cell viability, the colony formation, and migration ability were significantly decreased in the siRNA-SPOP group. The protein microarray screening showed that the expression of vascular endothelial growth factor receptor, matrix metallopeptidase-9, vascular cell adhesion molecule-1, and stromal cell-derived factor-1 in the siRNA group was significantly decreased and that the expression of granulocyte–macrophage colony-stimulating factor and E-cadherin was significantly increased (P<0.05. The relevant signaling pathways were the integrin-mediated cell surface interactions pathway and extracellular matrix organization signal pathway. SPOP gene silencing induced cell apoptosis, decreased cell viability, colony formation, and migration ability, and elevated the drug sensitivity in the RCC cells. A possible mechanism is that silencing SPOP induces the differential expression of E-cadherin, vascular endothelial

  20. Manipulation of saponin biosynthesis by RNA interference-mediated silencing of β-amyrin synthase gene expression in soybean.

    Science.gov (United States)

    Takagi, Kyoko; Nishizawa, Keito; Hirose, Aya; Kita, Akiko; Ishimoto, Masao

    2011-10-01

    Soybean seeds contain substantial amount of diverse triterpenoid saponins that influence the seed quality, although little is known about the physiologic functions of saponins in plants. We now describe the modification of saponin biosynthesis by RNA interference (RNAi)-mediated gene silencing targeted to β-amyrin synthase, a key enzyme in the synthesis of a common aglycon of soybean saponins. We identified two putative β-amyrin synthase genes in soybean that manifested distinct expression patterns with regard to developmental stage and tissue specificity. Given that one of these genes, GmBAS1, was expressed at a much higher level than the other (GmBAS2) in various tissues including the developing seeds, we constructed two RNAi vectors that encode self-complementary hairpin RNAs corresponding to the distinct regions of GmBAS1 under the control of a seed-specific promoter derived from the soybean gene for the α' subunit of the seed storage protein β-conglycinin. These vectors were introduced independently into soybean. Six independent transgenic lines exhibited a stable reduction in seed saponin content, with the extent of saponin deficiency correlating with the β-amyrin synthase mRNA depletion. Although some transgenic lines produced seeds almost devoid of saponins, no abnormality in their growth was apparent and the antioxidant activity of their seeds was similar to that of control seeds. These results suggest that saponins are not required for seed development and survival, and that soybean seeds may therefore be amenable to the modification of triterpenoid saponin content and composition through molecular biologic approaches.

  1. Systematic Identification and Assessment of Therapeutic Targets for Breast Cancer Based on Genome-Wide RNA Interference Transcriptomes

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    Yang Liu

    2017-02-01

    Full Text Available With accumulating public omics data, great efforts have been made to characterize the genetic heterogeneity of breast cancer. However, identifying novel targets and selecting the best from the sizeable lists of candidate targets is still a key challenge for targeted therapy, largely owing to the lack of economical, efficient and systematic discovery and assessment to prioritize potential therapeutic targets. Here, we describe an approach that combines the computational evaluation and objective, multifaceted assessment to systematically identify and prioritize targets for biological validation and therapeutic exploration. We first establish the reference gene expression profiles from breast cancer cell line MCF7 upon genome-wide RNA interference (RNAi of a total of 3689 genes, and the breast cancer query signatures using RNA-seq data generated from tissue samples of clinical breast cancer patients in the Cancer Genome Atlas (TCGA. Based on gene set enrichment analysis, we identified a set of 510 genes that when knocked down could significantly reverse the transcriptome of breast cancer state. We then perform multifaceted assessment to analyze the gene set to prioritize potential targets for gene therapy. We also propose drug repurposing opportunities and identify potentially druggable proteins that have been poorly explored with regard to the discovery of small-molecule modulators. Finally, we obtained a small list of candidate therapeutic targets for four major breast cancer subtypes, i.e., luminal A, luminal B, HER2+ and triple negative breast cancer. This RNAi transcriptome-based approach can be a helpful paradigm for relevant researches to identify and prioritize candidate targets for experimental validation.

  2. Review of the RNA Interference Pathway in Molluscs Including Some Possibilities for Use in Bivalves in Aquaculture

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    Leigh Owens

    2015-03-01

    Full Text Available Generalised reviews of RNA interference (RNAi in invertebrates, and for use in aquaculture, have taken for granted that RNAi pathways operate in molluscs, but inspection of such reviews show little specific evidence of such activity in molluscs. This review was to understand what specific research had been conducted on RNAi in molluscs, particularly with regard to aquaculture. There were questions of whether RNAi in molluscs functions similarly to the paradigm established for most eukaryotes or, alternatively, was it more similar to the ecdozoa and how RNAi may relate to disease control in aquaculture? RNAi in molluscs appears to have been only investigated in about 14 species, mostly as a gene silencing phenomenon. We can infer that microRNAs including let-7 are functional in molluscs. The genes/proteins involved in the actual RNAi pathways have only been rudimentarily investigated, so how homologous the genes and proteins are to other metazoa is unknown. Furthermore, how many different genes for each activity in the RNAi pathway are also unknown? The cephalopods have been greatly overlooked with only a single RNAi gene-silencing study found. The long dsRNA-linked interferon pathways seem to be present in molluscs, unlike some other invertebrates and could be used to reduce disease states in aquaculture. In particular, interferon regulatory factor genes have been found in molluscs of aquacultural importance such as Crassostrea, Mytilus, Pinctada and Haliotis. Two possible aquaculture scenarios are discussed, zoonotic norovirus and ostreid herpesvirus 1 to illustrate the possibilities. The entire field of RNAi in molluscs looks ripe for scientific exploitation and practical application.

  3. Enhancement of antiproliferative activity of interferons by RNA interference-mediated silencing of SOCS gene expression in tumor cells.

    Science.gov (United States)

    Takahashi, Yuki; Kaneda, Haruka; Takasuka, Nana; Hattori, Kayoko; Nishikawa, Makiya; Watanabe, Yoshihiko; Takakura, Yoshinobu

    2008-08-01

    The suppressor of cytokine signaling (SOCS) proteins, negative regulators of interferon (IFN)-induced signaling pathways, is involved in IFN resistance of tumor cells. To improve the growth inhibitory effect of IFN-beta and IFN-gamma on a murine melanoma cell line, B16-BL6, and a murine colon carcinoma cell line, Colon26 cells, SOCS-1 and SOCS-3 gene expression in tumor cells was downregulated by transfection of plasmid DNA expressing short hairpin RNA targeting one of these genes (pshSOCS-1 and pshSOCS-3, respectively). Transfection of pshSOCS-1 significantly increased the antiproliferative effect of IFN-gamma on B16-BL6 cells. However, any other combinations of plasmids and IFN had little effect on the growth of B16-BL6 cells. In addition, transfection of pshSOCS-1 and pshSOCS-3 produced little improvement in the effect of IFN on Colon26 cells. To understand the mechanism underlining these findings, the level of SOCS gene expression was measured by real time polymerase chain reaction. Addition of IFN-gamma greatly increased the SOCS-1 mRNA expression in B16-BL6 cells. Taking into account the synergistic effect of pshSOCS-1 and IFN-gamma on the growth of B16-BL6 cells, these findings suggest that IFN-gamma-induced high SOCS-1 gene expression in B16-BL6 cells significantly interferes with the antiproliferative effect of IFN-gamma. These results indicate that silencing SOCS gene expression can be an effective strategy to enhance the antitumor effect of IFN under conditions in which the SOCS gene expression is upregulated by IFN.

  4. RNA interference of three up-regulated transcripts associated with insecticide resistance in an imidacloprid resistant population of Leptinotarsa decemlineata.

    Science.gov (United States)

    Clements, Justin; Schoville, Sean; Peterson, Nathan; Huseth, Anders S; Lan, Que; Groves, Russell L

    2017-01-01

    The Colorado potato beetle, Leptinotarsa decemlineata (Say), is a major agricultural pest of potatoes in the Central Sands production region of Wisconsin. Previous studies have shown that populations of L. decemlineata have become resistant to many classes of insecticides, including the neonicotinoid insecticide, imidacloprid. Furthermore, L. decemlineata has multiple mechanisms of resistance to deal with a pesticide insult, including enhanced metabolic detoxification by cytochrome p450s and glutathione S-transferases. With recent advances in the transcriptomic analysis of imidacloprid susceptible and resistant L. decemlineata populations, it is possible to investigate the role of candidate genes involved in imidacloprid resistance. A recently annotated transcriptome analysis of L. decemlineata was obtained from select populations of L. decemlineata collected in the Central Sands potato production region, which revealed a subset of mRNA transcripts constitutively up-regulated in resistant populations. We hypothesize that a portion of the up-regulated transcripts encoding for genes within the resistant populations also encode for pesticide resistance and can be suppressed to re-establish a susceptible phenotype. In this study, a discrete set of three up-regulated targets were selected for RNA interference experiments using a resistant L. decemlineata population. Following the successful suppression of transcripts encoding for a cytochrome p450, a cuticular protein, and a glutathione synthetase protein in a select L. decemlineata population, we observed reductions in measured resistance to imidacloprid that strongly suggest these genes control essential steps in imidacloprid metabolism in these field populations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

    Science.gov (United States)

    Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

    2009-12-01

    FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast

  6. Growth inhibition of head and neck squamous cell carcinoma cells by sgRNA targeting the cyclin D1 mRNA based on TRUE gene silencing.

    Directory of Open Access Journals (Sweden)

    Satoshi Iizuka

    Full Text Available Head and neck squamous cell carcinoma (HNSCC exhibits increased expression of cyclin D1 (CCND1. Previous studies have shown a correlation between poor prognosis of HNSCC and cyclin D1 overexpression. tRNase ZL-utilizing efficacious gene silencing (TRUE gene silencing is one of the RNA-mediated gene expression control technologies that have therapeutic potential. This technology is based on a unique enzymatic property of mammalian tRNase ZL, which is that it can cleave any target RNA at any desired site by recognizing a pre-tRNA-like complex formed between the target RNA and an artificial small guide RNA (sgRNA. In this study, we designed several sgRNAs targeting human cyclin D1 mRNA to examine growth inhibition of HNSCC cells. Transfection of certain sgRNAs decreased levels of cyclin D1 mRNA and protein in HSC-2 and HSC-3 cells, and also inhibited their proliferation. The combination of these sgRNAs and cisplatin showed more than additive inhibition of cancer cell growth. These findings demonstrate that TRUE gene silencing of cyclin D1 leads to inhibition of the growth of HNSCC cells and suggest that these sgRNAs alone or combined with cisplatin may be a useful new therapy for HNSCCs.

  7. Stop feeling: inhibition of emotional interference following stop-signal trials.

    Science.gov (United States)

    Kalanthroff, Eyal; Cohen, Noga; Henik, Avishai

    2013-01-01

    Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control [longer stop-signal reaction time (SSRT)] following negative, compared to neutral pictures. Most importantly, results show decreased emotional interference following stop-signal trials. These results show that the inhibitory control component of executive control can serve to decrease emotional effects. We suggest that inhibitory control and emotion have a two-way connection in which emotion disrupts inhibitory control and activation of inhibitory control disrupts emotion.

  8. Stop feeling: Inhibition of emotional interference following stop-signal trials

    Directory of Open Access Journals (Sweden)

    Eyal eKalanthroff

    2013-03-01

    Full Text Available Although a great deal of literature has been dedicated to the mutual links between emotion and the selective attention component of executive control, there is very little data regarding the links between emotion and the inhibitory component of executive control. In the current study we employed an emotional stop-signal task in order to examine whether emotion modulates and is modulated by inhibitory control. Results replicated previous findings showing reduced inhibitory control (longer stop-signal reaction time following negative, compared to neutral pictures. Most importantly, results show decreased emotional interference following stop-signal trials. These results show that the inhibitory control component of executive control can serve to decrease emotional effects. We suggest that inhibitory control and emotion have a two-way connection in which emotion disrupts inhibitory control and activation of inhibitory control disrupts emotion.

  9. Targeting chitinase gene of Helicoverpa armigera by host-induced RNA interference confers insect resistance in tobacco and tomato.

    Science.gov (United States)

    Mamta; Reddy, K R K; Rajam, M V

    2016-02-01

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a devastating agricultural insect pest with broad spectrum of host range, causing million dollars crop loss annually. Limitations in the present conventional and transgenic approaches have made it crucial to develop sustainable and environmental friendly methods for crop improvement. In the present study, host-induced RNA interference (HI-RNAi) approach was used to develop H. armigera resistant tobacco and tomato plants. Chitinase (HaCHI) gene, critically required for insect molting and metamorphosis was selected as a potential target. Hair-pin RNAi construct was prepared from the conserved off-target free partial HaCHI gene sequence and was used to generate several HaCHI-RNAi tobacco and tomato plants. Northern hybridization confirmed the production of HaCHI gene-specific siRNAs in HaCHI-RNAi tobacco and tomato lines. Continuous feeding on leaves of RNAi lines drastically reduced the target gene transcripts and consequently, affected the overall growth and survival of H. armigera. Various developmental deformities were also manifested in H. armigera larvae after feeding on the leaves of RNAi lines. These results demonstrated the role of chitinase in insect development and potential of HI-RNAi for effective management of H. armigera.

  10. Interspecific RNA Interference of SHOOT MERISTEMLESS-Like Disrupts Cuscuta pentagona Plant Parasitism[C][W][OA

    Science.gov (United States)

    Alakonya, Amos; Kumar, Ravi; Koenig, Daniel; Kimura, Seisuke; Townsley, Brad; Runo, Steven; Garces, Helena M.; Kang, Julie; Yanez, Andrea; David-Schwartz, Rakefet; Machuka, Jesse; Sinha, Neelima

    2012-01-01

    Infection of crop species by parasitic plants is a major agricultural hindrance resulting in substantial crop losses worldwide. Parasitic plants establish vascular connections with the host plant via structures termed haustoria, which allow acquisition of water and nutrients, often to the detriment of the infected host. Despite the agricultural impact of parasitic plants, the molecular and developmental processes by which host/parasitic interactions are established are not well understood. Here, we examine the development and subsequent establishment of haustorial connections by the parasite dodder (Cuscuta pentagona) on tobacco (Nicotiana tabacum) plants. Formation of haustoria in dodder is accompanied by upregulation of dodder KNOTTED-like homeobox transcription factors, including SHOOT MERISTEMLESS-like (STM). We demonstrate interspecific silencing of a STM gene in dodder driven by a vascular-specific promoter in transgenic host plants and find that this silencing disrupts dodder growth. The reduced efficacy of dodder infection on STM RNA interference transgenics results from defects in haustorial connection, development, and establishment. Identification of transgene-specific small RNAs in the parasite, coupled with reduced parasite fecundity and increased growth of the infected host, demonstrates the efficacy of interspecific small RNA–mediated silencing of parasite genes. This technology has the potential to be an effective method of biological control of plant parasite infection. PMID:22822208

  11. PDX-1 Is a Therapeutic Target for Pancreatic Cancer, Insulinoma and Islet Neoplasia Using a Novel RNA Interference Platform

    Science.gov (United States)

    Liu, Shi-He; Rao, Donald D.; Nemunaitis, John; Senzer, Neil; Zhou, Guisheng; Dawson, David; Gingras, Marie-Claude; Wang, Zhaohui; Gibbs, Richard; Norman, Michael; Templeton, Nancy S.; DeMayo, Francesco J.; O'Malley, Bert; Sanchez, Robbi; Fisher, William E.; Brunicardi, F. Charles

    2012-01-01

    Pancreatic and duodenal homeobox-1 (PDX-1) is a transcription factor that regulates insulin expression and islet maintenance in the adult pancreas. Our recent studies demonstrate that PDX-1 is an oncogene for pancreatic cancer and is overexpressed in pancreatic cancer. The purpose of this study was to demonstrate that PDX-1 is a therapeutic target for both hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Immunohistochemistry of human pancreatic and islet neoplasia specimens revealed marked PDX-1 overexpression, suggesting PDX-1 as a “drugable” target within these diseases. To do so, a novel RNA interference effector platform, bifunctional shRNAPDX-1, was developed and studied in mouse and human cell lines as well as in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Systemic delivery of bi-shRNAhumanPDX-1 lipoplexes resulted in marked reduction of tumor volume and improved survival in a human pancreatic cancer xenograft mouse model. bi-shRNAmousePDX-1 lipoplexes prevented death from hyperinsulinemia and hypoglycemia in an insulinoma mouse model. shRNAmousePDX-1 lipoplexes reversed hyperinsulinemia and hypoglycemia in an immune-competent mouse model of islet neoplasia. PDX-1 was overexpressed in pancreatic neuroendocrine tumors and nesidioblastosis. These data demonstrate that PDX-1 RNAi therapy controls hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia, therefore, PDX-1 is a potential therapeutic target for these pancreatic diseases. PMID:22905092

  12. The ability to manage self-proposed projects between 1;3 and 2;0 years old: a study of inhibition and resistance to interference

    Directory of Open Access Journals (Sweden)

    Estanislao Pastor-Mallol

    2015-05-01

    Full Text Available This study examines very young children's ability to manage self-proposed projects by using the inhibitory function and resistance to interference. In a natural environment and using an observational method, we conducted a longitudinal study of a sample observed at 1;3, 1;6, 1;9 and 2;0 years old. The research was divided into two studies which followed different procedures and looked at the projects carried out, the interferences produced and the functioning of inhibition. We observed significant differences in the execution of inhibition at the different age groups. We also describe general cognitive functions in terms of significant patterns, and determine that the use of inhibition is linked not only to age but also to the activity complexity level and the type of interference.

  13. Structural Basis for Specific Inhibition of tRNA Synthetase by an ATP Competitive Inhibitor.

    Science.gov (United States)

    Fang, Pengfei; Han, Hongyan; Wang, Jing; Chen, Kaige; Chen, Xin; Guo, Min

    2015-06-18

    Pharmaceutical inhibitors of aminoacyl-tRNA synthetases demand high species and family specificity. The antimalarial ATP-mimetic cladosporin selectively inhibits Plasmodium falciparum LysRS (PfLysRS). How the binding to a universal ATP site achieves the specificity is unknown. Here we report three crystal structures of cladosporin with human LysRS, PfLysRS, and a Pf-like human LysRS mutant. In all three structures, cladosporin occupies the class defining ATP-binding pocket, replacing the adenosine portion of ATP. Three residues holding the methyltetrahydropyran moiety of cladosporin are critical for the specificity of cladosporin against LysRS over other class II tRNA synthetase families. The species-exclusive inhibition of PfLysRS is linked to a structural divergence beyond the active site that mounts a lysine-specific stabilizing response to binding cladosporin. These analyses reveal that inherent divergence of tRNA synthetase structural assembly may allow for highly specific inhibition even through the otherwise universal substrate binding pocket and highlight the potential for structure-driven drug development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Method for widespread microRNA-155 inhibition prolongs survival in ALS-model mice

    Science.gov (United States)

    Koval, Erica D.; Shaner, Carey; Zhang, Peter; du Maine, Xavier; Fischer, Kimberlee; Tay, Jia; Chau, B. Nelson; Wu, Gregory F.; Miller, Timothy M.

    2013-01-01

    microRNAs (miRNAs) are dysregulated in a variety of disease states, suggesting that this newly discovered class of gene expression repressors may be viable therapeutic targets. A microarray of miRNA changes in ALS-model superoxide dismutase 1 (SOD1)G93A rodents identified 12 miRNAs as significantly changed. Six miRNAs tested in human ALS tissues were confirmed increased. Specifically, miR-155 was increased 5-fold in mice and 2-fold in human spinal cords. To test miRNA inhibition in the central nervous system (CNS) as a potential novel therapeutic, we developed oligonucleotide-based miRNA inhibitors (anti-miRs) that could inhibit miRNAs throughout the CNS and in the periphery. Anti-miR-155 caused global derepression of targets in peritoneal macrophages and, following intraventricular delivery, demonstrated widespread functional distribution in the brain and spinal cord. After treating SOD1G93A mice with anti-miR-155, we significantly extended survival by 10 days and disease duration by 15 days (38%) while a scrambled control anti-miR did not significantly improve survival or disease duration. Therefore, antisense oligonucleotides may be used to successfully inhibit miRNAs throughout the brain and spinal cord, and miR-155 is a promising new therapeutic target for human ALS. PMID:23740943

  15. Inhibition of erythropoietin siRNA on corneal neovascularization of rabbit

    Directory of Open Access Journals (Sweden)

    Yu-Shun Xue

    2017-03-01

    Full Text Available AIM: To observe the expression of erythropoietin(EPOon the corneal of rabbit and evaluate the inhibition effect of EPO siRNA on corneal neovascularization(CNV. METHODS: Totally 22 healthy rabbits were randomly divided into 2 groups, which were experimental group and normal control group. Both eyes of rabbits in experimental group were chosen to establish corneal neovascularization model by alkali burn. The morphologic change of corneal was observed with slit lamp microscope and the area of CNV was calculated every day. After alkali burn, the right eye of the experimental group was accepted EPO siRNA injection under the conjunctiva, and the left eye was assigned to be experimental control group. The corneal with CNV was collected for immunohistochemistry at 3d, 7d, 14d, 21d after alkali burn, and the expression of EPO was measured. RESULTS: CNV began growing at the 3d after alkali burn in experimental group, and it was vigorous growing at 7d-14d period. The result of immunohistochemistry shows that the expression of EPO increased after the operation. Compared with experimental group, the rabbits who were treated by EPO siRNA was found with less neovascularization on their corneal, and the expression of EPO decreased. There were statistical significance between the two group at different time(PCONCLUSION: EPO is likely to play an important role on CNV growth, and EPO siRNA can inhibit the growth of CNV by restraining the expression of EPO.

  16. Emetine inhibits replication of RNA and DNA viruses without generating drug-resistant virus variants.

    Science.gov (United States)

    Khandelwal, Nitin; Chander, Yogesh; Rawat, Krishan Dutt; Riyesh, Thachamvally; Nishanth, Chikkahonnaiah; Sharma, Shalini; Jindal, Naresh; Tripathi, Bhupendra N; Barua, Sanjay; Kumar, Naveen

    2017-08-01

    At a noncytotoxic concentration, emetine was found to inhibit replication of DNA viruses [buffalopoxvirus (BPXV) and bovine herpesvirus 1 (BHV-1)] as well as RNA viruses [peste des petits ruminants virus (PPRV) and Newcastle disease virus (NDV)]. Using the time-of-addition and virus step-specific assays, we showed that emetine treatment resulted in reduced synthesis of viral RNA (PPRV and NDV) and DNA (BPXV and BHV-1) as well as inhibiting viral entry (NDV and BHV-1). In addition, emetine treatment also resulted in decreased synthesis of viral proteins. In a cell free endogenous viral polymerase assay, emetine was found to significantly inhibit replication of NDV, but not BPXV genome, suggesting that besides directly inhibiting specific viral polymerases, emetine may also target other factors essentially required for efficient replication of the viral genome. Moreover, emetine was found to significantly inhibit BPXV-induced pock lesions on chorioallantoic membrane (CAM) along with associated mortality of embryonated chicken eggs. At a lethal dose 50 (LD 50 ) of 126.49 ng/egg and at an effective concentration 50 (EC 50 ) of 3.03 ng/egg, the therapeutic index of the emetine against BPXV was determined to be 41.74. Emetine was also found to significantly delay NDV-induced mortality in chicken embryos associated with reduced viral titers. Further, emetine-resistant mutants were not observed upon long-term (P = 25) sequential passage of BPXV and NDV in cell culture. Collectively, we have extended the effective antiviral activity of emetine against diverse groups of DNA and RNA viruses and propose that emetine could provide significant therapeutic value against some of these viruses without inducing an antiviral drug-resistant phenotype. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Methods for reducing interference in the Complementary Learning Systems model: oscillating inhibition and autonomous memory rehearsal.

    Science.gov (United States)

    Norman, Kenneth A; Newman, Ehren L; Perotte, Adler J

    2005-11-01

    The stability-plasticity problem (i.e. how the brain incorporates new information into its model of the world, while at the same time preserving existing knowledge) has been at the forefront of computational memory research for several decades. In this paper, we critically evaluate how well the Complementary Learning Systems theory of hippocampo-cortical interactions addresses the stability-plasticity problem. We identify two major challenges for the model: Finding a learning algorithm for cortex and hippocampus that enacts selective strengthening of weak memories, and selective punishment of competing memories; and preventing catastrophic forgetting in the case of non-stationary environments (i.e. when items are temporarily removed from the training set). We then discuss potential solutions to these problems: First, we describe a recently developed learning algorithm that leverages neural oscillations to find weak parts of memories (so they can be strengthened) and strong competitors (so they can be punished), and we show how this algorithm outperforms other learning algorithms (CPCA Hebbian learning and Leabra at memorizing overlapping patterns. Second, we describe how autonomous re-activation of memories (separately in cortex and hippocampus) during REM sleep, coupled with the oscillating learning algorithm, can reduce the rate of forgetting of input patterns that are no longer present in the environment. We then present a simple demonstration of how this process can prevent catastrophic interference in an AB-AC learning paradigm.

  18. Method of inhibiting plant virus pathogen infections by crispr/cas9-mediated interference

    KAUST Repository

    Mahfouz, Magdy Mahmoud

    2016-11-24

    A genetically modified tobacco plant or tomato plant resistant to at least one pathogenic geminiviridae virus species is provided. The plant comprises a heterologous CRISPR/Cas9 system and at least one heterologous nucleotide sequence that is capable of hybridizing to a nucleotide sequence of the pathogenic virus and that directs inactivation of the pathogenic virus species or plurality of viral species by the CRISPR/Cas9 system. The heterologous nucleotide sequence can be complementary to, but not limited to an Intergenic Region (IR) of the Tomato Yellow Leaf Curl Virus (TYLCV), Further provided are methods of generating a genetically modified plant that is resistant to a virus pathogen by a heterologous CRISPR/Cas9 system and expression of a gRNA specifically targeting the virus.

  19. Interferência por RNA: uma nova alternativa para terapia nas doenças reumáticas RNA interference: a new alternative for rheumatic diseases therapy

    Directory of Open Access Journals (Sweden)

    Natália Regine de França

    2010-12-01

    Full Text Available A interferência por RNA (RNAi é um mecanismo de silenciamento gênico pós-transcricional conservado durante a evolução. Esse mecanismo, recentemente descrito, é mediado por pequenos RNAs de fita dupla (dsRNAs capazes de reconhecer especificamente uma sequência de mRNA-alvo e mediar sua clivagem ou repressão traducional. O emprego da RNAi como uma ferramenta de terapia gênica tem sido muito estudado, especialmente em infecções virais, câncer, desordens genéticas herdadas, doenças cardiovasculares e mesmo em doenças reumáticas. Aliados aos dados do genoma humano, os conhecimentos do silenciamento gênico mediado por RNAi podem permitir a determinação funcional de praticamente qualquer gene expresso em uma célula e sua implicação para o funcionamento e homeostase celular. Vários estudos terapêuticos in vitro e in vivo em modelos de doenças autoimunes vêm sendo realizados com resultados encorajadores. As vias de quebra de tolerância e inflamação são alvos potenciais para terapia com RNAi em doenças inflamatórias e autoimunes. Nesta revisão vamos recordar os princípios básicos da RNAi e discutir os aspectos que levaram ao desenvolvimento de propostas terapêuticas baseadas em RNAi, começando pelos estudos in vitro de desenvolvimento de ferramentas e identificação de alvos, chegando até os estudos pré-clínicos de disponibilização da droga in vivo, e testes em células humanas e modelos animais de doenças autoimunes. Por fim, vamos revisar os últimos avanços da experiência clínica da terapia com RNAiRNA interference (RNAi is a post-transcriptional gene silencing mechanism preserved during evolution. This mechanism, recently described, is mediated by small double-stranded RNAs (dsRNAs that can specifically recognize a target mRNA sequence and mediate its cleavage or translational repression. The use of RNAi as a tool for gene therapy has been extensively studied, especially in viral infections, cancer

  20. STC1 interference on calcitonin family of receptors signaling during osteoblastogenesis via adenylate cyclase inhibition.

    Science.gov (United States)

    Terra, Silvia R; Cardoso, João Carlos R; Félix, Rute C; Martins, Leo Anderson M; Souza, Diogo Onofre G; Guma, Fatima C R; Canário, Adelino Vicente M; Schein, Vanessa

    2015-03-05

    Stanniocalcin 1 (STC1) and calcitonin gene-related peptide (CGRP) are involved in bone formation/remodeling. Here we investigate the effects of STC1 on functional heterodimer complex CALCRL/RAMP1, expression and activity during osteoblastogenesis. STC1 did not modify CALCRL and ramp1 gene expression during osteoblastogenesis when compared to controls. However, plasma membrane spatial distribution of CALCRL/RAMP1 was modified in 7-day pre-osteoblasts exposed to either CGRP or STC1, and both peptides induced CALCRL and RAMP1 assembly. CGRP, but not STC1 stimulated cAMP accumulation in 7-day osteoblasts and in CALCRL/RAMP1 transfected HEK293 cells. Furthermore, STC1 inhibited forskolin stimulated cAMP accumulation of HEK293 cells, but not in CALCRL/RAMP1 transfected HEK293 cells. However, STC1 inhibited cAMP accumulation in calcitonin receptor (CTR) HEK293 transfected cells stimulated by calcitonin. In conclusion, STC1 signals through inhibitory G-protein modulates CGRP receptor spatial localization during osteoblastogenesis and may function as a regulatory factor interacting with calcitonin peptide members during bone formation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Inhibition of dengue virus replication by novel inhibitors of RNA-dependent RNA polymerase and protease activities.

    Science.gov (United States)

    Pelliccia, Sveva; Wu, Yu-Hsuan; Coluccia, Antonio; La Regina, Giuseppe; Tseng, Chin-Kai; Famiglini, Valeria; Masci, Domiziana; Hiscott, John; Lee, Jin-Ching; Silvestri, Romano

    2017-12-01

    Dengue virus (DENV) is the leading mosquito-transmitted viral infection in the world. With more than 390 million new infections annually, and up to 1 million clinical cases with severe disease manifestations, there continues to be a need to develop new antiviral agents against dengue infection. In addition, there is no approved anti-DENV agents for treating DENV-infected patients. In the present study, we identified new compounds with anti-DENV replication activity by targeting viral replication enzymes - NS5, RNA-dependent RNA polymerase (RdRp) and NS3 protease, using cell-based reporter assay. Subsequently, we performed an enzyme-based assay to clarify the action of these compounds against DENV RdRp or NS3 protease activity. Moreover, these compounds exhibited anti-DENV activity in vivo in the ICR-suckling DENV-infected mouse model. Combination drug treatment exhibited a synergistic inhibition of DENV replication. These results describe novel prototypical small anti-DENV molecules for further development through compound modification and provide potential antivirals for treating DENV infection and DENV-related diseases.

  2. Expression of RNA interference triggers from an oncolytic herpes simplex virus results in specific silencing in tumour cells in vitro and tumours in vivo

    International Nuclear Information System (INIS)

    Anesti, Anna-Maria; Simpson, Guy R; Price, Toby; Pandha, Hardev S; Coffin, Robert S

    2010-01-01

    Delivery of small interfering RNA (siRNA) to tumours remains a major obstacle for the development of RNA interference (RNAi)-based therapeutics. Following the promising pre-clinical and clinical results with the oncolytic herpes simplex virus (HSV) OncoVEX GM-CSF , we aimed to express RNAi triggers from oncolytic HSV, which although has the potential to improve treatment by silencing tumour-related genes, was not considered possible due to the highly oncolytic properties of HSV. To evaluate RNAi-mediated silencing from an oncolytic HSV backbone, we developed novel replicating HSV vectors expressing short-hairpin RNA (shRNA) or artificial microRNA (miRNA) against the reporter genes green fluorescent protein (eGFP) and β-galactosidase (lacZ). These vectors were tested in non-tumour cell lines in vitro and tumour cells that are moderately susceptible to HSV infection both in vitro and in mice xenografts in vivo. Silencing was assessed at the protein level by fluorescent microscopy, x-gal staining, enzyme activity assay, and western blotting. Our results demonstrate that it is possible to express shRNA and artificial miRNA from an oncolytic HSV backbone, which had not been previously investigated. Furthermore, oncolytic HSV-mediated delivery of RNAi triggers resulted in effective and specific silencing of targeted genes in tumour cells in vitro and tumours in vivo, with the viruses expressing artificial miRNA being comprehensibly more effective. This preliminary data provide the first demonstration of oncolytic HSV-mediated expression of shRNA or artificial miRNA and silencing of targeted genes in tumour cells in vitro and in vivo. The vectors developed in this study are being adapted to silence tumour-related genes in an ongoing study that aims to improve the effectiveness of oncolytic HSV treatment in tumours that are moderately susceptible to HSV infection and thus, potentially improve response rates seen in human clinical trials

  3. The RNA-mediated, asymmetric ring regulatory mechanism of the transcription termination Rho helicase decrypted by time-resolved nucleotide analog interference probing (trNAIP).

    Science.gov (United States)

    Soares, Emilie; Schwartz, Annie; Nollmann, Marcello; Margeat, Emmanuel; Boudvillain, Marc

    2014-08-01

    Rho is a ring-shaped, ATP-dependent RNA helicase/translocase that dissociates transcriptional complexes in bacteria. How RNA recognition is coupled to ATP hydrolysis and translocation in Rho is unclear. Here, we develop and use a new combinatorial approach, called time-resolved Nucleotide Analog Interference Probing (trNAIP), to unmask RNA molecular determinants of catalytic Rho function. We identify a regulatory step in the translocation cycle involving recruitment of the 2'-hydroxyl group of the incoming 3'-RNA nucleotide by a Rho subunit. We propose that this step arises from the intrinsic weakness of one of the subunit interfaces caused by asymmetric, split-ring arrangement of primary RNA tethers around the Rho hexamer. Translocation is at highest stake every seventh nucleotide when the weak interface engages the incoming 3'-RNA nucleotide or breaks, depending on RNA threading constraints in the Rho pore. This substrate-governed, 'test to run' iterative mechanism offers a new perspective on how a ring-translocase may function or be regulated. It also illustrates the interest and versatility of the new trNAIP methodology to unveil the molecular mechanisms of complex RNA-based systems. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. MicroRNA-375 inhibits colorectal cancer growth by targeting PIK3CA

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yihui [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Tang, Qingchao [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China); Li, Mingqi; Jiang, Shixiong [Department of Colorectal Surgery, The Third Affiliated Hospital of Harbin Medical University, 150 Haping Road, 150081 Harbin (China); Wang, Xishan, E-mail: wxshan12081@163.com [Cancer Center, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, 150086 Harbin (China)

    2014-02-07

    Highlights: • miR-375 is downregulated in colorectal cancer cell lines and tissues. • miR-375 inhibits colorectal cancer cell growth by targeting PIK3CA. • miR-375 inhibits colorectal cancer cell growth in xenograft nude mice model. - Abstract: Colorectal cancer (CRC) is the second most common cause of death from cancer. MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by triggering RNA degradation or interfering with translation. Aberrant miRNA expression is involved in human disease including cancer. Herein, we showed that miR-375 was frequently down-regulated in human colorectal cancer cell lines and tissues when compared to normal human colon tissues. PIK3CA was identified as a potential miR-375 target by bioinformatics. Overexpression of miR-375 in SW480 and HCT15 cells reduced PIK3CA protein expression. Subsequently, using reporter constructs, we showed that the PIK3CA untranslated region (3′-UTR) carries the directly binding site of miR-375. Additionally, miR-375 suppressed CRC cell proliferation and colony formation and led to cell cycle arrest. Furthermore, miR-375 overexpression resulted in inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. SiRNA-mediated silencing of PIK3CA blocked the inhibitory effect of miR-375 on CRC cell growth. Lastly, we found overexpressed miR-375 effectively repressed tumor growth in xenograft animal experiments. Taken together, we propose that overexpression of miR-375 may provide a selective growth inhibition for CRC cells by targeting PI3K/Akt signaling pathway.

  5. Double-stranded RNA interferes in a sequence-specific manner with the infection of representative members of the two viroid families

    International Nuclear Information System (INIS)

    Carbonell, Alberto; Martinez de Alba, Angel-Emilio; Flores, Ricardo; Gago, Selma

    2008-01-01

    Infection by viroids, non-protein-coding circular RNAs, occurs with the accumulation of 21-24 nt viroid-derived small RNAs (vd-sRNAs) with characteristic properties of small interfering RNAs (siRNAs) associated to RNA silencing. The vd-sRNAs most likely derive from dicer-like (DCL) enzymes acting on viroid-specific dsRNA, the key elicitor of RNA silencing, or on the highly structured genomic RNA. Previously, viral dsRNAs delivered mechanically or agroinoculated have been shown to interfere with virus infection in a sequence-specific manner. Here, we report similar results with members of the two families of nuclear- and chloroplast-replicating viroids. Moreover, homologous vd-sRNAs co-delivered mechanically also interfered with one of the viroids examined. The interference was sequence-specific, temperature-dependent and, in some cases, also dependent on the dose of the co-inoculated dsRNA or vd-sRNAs. The sequence-specific nature of these effects suggests the involvement of the RNA induced silencing complex (RISC), which provides sequence specificity to RNA silencing machinery. Therefore, viroid titer in natural infections might be regulated by the concerted action of DCL and RISC. Viroids could have evolved their secondary structure as a compromise between resistance to DCL and RISC, which act preferentially against RNAs with compact and relaxed secondary structures, respectively. In addition, compartmentation, association with proteins or active replication might also help viroids to elude their host RNA silencing machinery

  6. Inhibition of the acetyl lysine-binding pocket of bromodomain and extraterminal domain proteins interferes with adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goupille, Olivier [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Penglong, Tipparat [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Thalassemia Research Center, Mahidol University (Thailand); Kadri, Zahra; Granger-Locatelli, Marine [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Fucharoen, Suthat [Thalassemia Research Center, Mahidol University (Thailand); Maouche-Chrétien, Leila [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); INSERM, Paris (France); Prost, Stéphane [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Leboulch, Philippe [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Thalassemia Research Center, Mahidol University (Thailand); Chrétien, Stany, E-mail: stany.chretien@cea.fr [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); INSERM, Paris (France)

    2016-04-15

    The bromodomain and extraterminal (BET) domain family proteins are epigenetic modulators involved in the reading of acetylated lysine residues. The first BET protein inhibitor to be identified, (+)-JQ1, a thienotriazolo-1, 4-diazapine, binds selectively to the acetyl lysine-binding pocket of BET proteins. We evaluated the impact on adipogenesis of this druggable targeting of chromatin epigenetic readers, by investigating the physiological consequences of epigenetic modifications through targeting proteins binding to chromatin. JQ1 significantly inhibited the differentiation of 3T3-L1 preadipocytes into white and brown adipocytes by down-regulating the expression of genes involved in adipogenesis, particularly those encoding the peroxisome proliferator-activated receptor (PPAR-γ), the CCAAT/enhancer-binding protein (C/EBPα) and, STAT5A and B. The expression of a constitutively activated STAT5B mutant did not prevent inhibition by JQ1. Thus, the association of BET/STAT5 is required for adipogenesis but STAT5 transcription activity is not the only target of JQ1. Treatment with JQ1 did not lead to the conversion of white adipose tissue into brown adipose tissue (BAT). BET protein inhibition thus interferes with generation of adipose tissue from progenitors, confirming the importance of the connections between epigenetic mechanisms and specific adipogenic transcription factors. - Highlights: • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into white adipocytes. • JQ1 affected clonal cell expansion and abolished lipid accumulation. • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into brown adipocytes. • JQ1 treatment did not lead to the conversion of white adipose tissue into brown adipose tissue. • JQ1 decreased STAT5 expression, but STAT5B{sup ca} expression did not restore adipogenesis.

  7. Inhibition of the acetyl lysine-binding pocket of bromodomain and extraterminal domain proteins interferes with adipogenesis

    International Nuclear Information System (INIS)

    Goupille, Olivier; Penglong, Tipparat; Kadri, Zahra; Granger-Locatelli, Marine; Fucharoen, Suthat; Maouche-Chrétien, Leila; Prost, Stéphane; Leboulch, Philippe; Chrétien, Stany

    2016-01-01

    The bromodomain and extraterminal (BET) domain family proteins are epigenetic modulators involved in the reading of acetylated lysine residues. The first BET protein inhibitor to be identified, (+)-JQ1, a thienotriazolo-1, 4-diazapine, binds selectively to the acetyl lysine-binding pocket of BET proteins. We evaluated the impact on adipogenesis of this druggable targeting of chromatin epigenetic readers, by investigating the physiological consequences of epigenetic modifications through targeting proteins binding to chromatin. JQ1 significantly inhibited the differentiation of 3T3-L1 preadipocytes into white and brown adipocytes by down-regulating the expression of genes involved in adipogenesis, particularly those encoding the peroxisome proliferator-activated receptor (PPAR-γ), the CCAAT/enhancer-binding protein (C/EBPα) and, STAT5A and B. The expression of a constitutively activated STAT5B mutant did not prevent inhibition by JQ1. Thus, the association of BET/STAT5 is required for adipogenesis but STAT5 transcription activity is not the only target of JQ1. Treatment with JQ1 did not lead to the conversion of white adipose tissue into brown adipose tissue (BAT). BET protein inhibition thus interferes with generation of adipose tissue from progenitors, confirming the importance of the connections between epigenetic mechanisms and specific adipogenic transcription factors. - Highlights: • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into white adipocytes. • JQ1 affected clonal cell expansion and abolished lipid accumulation. • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into brown adipocytes. • JQ1 treatment did not lead to the conversion of white adipose tissue into brown adipose tissue. • JQ1 decreased STAT5 expression, but STAT5B"c"a expression did not restore adipogenesis.

  8. Long non-coding RNA MEG3 inhibits the proliferation and metastasis of oral squamous cell carcinoma by regulating the WNT/β-catenin signaling pathway.

    Science.gov (United States)

    Liu, Zongxiang; Wu, Cui; Xie, Nina; Wang, Penglai

    2017-10-01

    This study aimed to investigate how long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) inhibits the growth and metastasis of oral squamous cell carcinoma (OSCC) by regulating WNT/β-catenin signaling pathway in order to explore the antitumor effect of MEG3 and to provide a potential molecular target for the treatment of OSCC. The RT-qPCR technique was used to quantitatively analyze the expression of MEG3 in cancer and adjacent tissues collected from the patients after surgery. Using the Lipofectamine method, the MEG3 overexpression vector and the siRNA interference vector were constructed and transfected into SCC15 and Cal27 cells, respectively, followed by cell proliferation, apoptosis and metastasis analyses. The semi-quantitative analysis of the expression of the β-catenin protein in transfected cells was performed by the western blot analysis, and the activity of the WNT/β-catenin signaling pathway was analyzed using the TOP/FOP flash reporters. In addition, the cells were treated with decitabine to investigate the correlation between the MEG3 expression and the DNA methylation. Results showed that the expression level of MEG3 was significantly decreased in OSCC (psuppressor by inhibiting the WNT/β-catenin signaling pathway. In addition, the expression of the MEG3 was significantly affected by the degree of DNA methylation. It was concluded that the lncRNA MEG3 can inhibit the growth and metastasis of OSCC by negatively regulating the WNT/β-catenin signaling pathway.

  9. The pre-existing population of 5S rRNA effects p53 stabilization during ribosome biogenesis inhibition.

    Science.gov (United States)

    Onofrillo, Carmine; Galbiati, Alice; Montanaro, Lorenzo; Derenzini, Massimo

    2017-01-17

    Pre-ribosomal complex RPL5/RPL11/5S rRNA (5S RNP) is considered the central MDM2 inhibitory complex that control p53 stabilization during ribosome biogenesis inhibition. Despite its role is well defined, the dynamic of 5S RNP assembly still requires further characterization. In the present work, we report that MDM2 inhibition is dependent by a pre-existing population of 5S rRNA.

  10. Group II intron inhibits conjugative relaxase expression in bacteria by mRNA targeting

    Science.gov (United States)

    Piazza, Carol Lyn; Smith, Dorie

    2018-01-01

    Group II introns are mobile ribozymes that are rare in bacterial genomes, often cohabiting with various mobile elements, and seldom interrupting housekeeping genes. What accounts for this distribution has not been well understood. Here, we demonstrate that Ll.LtrB, the group II intron residing in a relaxase gene on a conjugative plasmid from Lactococcus lactis, inhibits its host gene expression and restrains the naturally cohabiting mobile element from conjugative horizontal transfer. We show that reduction in gene expression is mainly at the mRNA level, and results from the interaction between exon-binding sequences (EBSs) in the intron and intron-binding sequences (IBSs) in the mRNA. The spliced intron targets the relaxase mRNA and reopens ligated exons, causing major mRNA loss. Taken together, this study provides an explanation for the distribution and paucity of group II introns in bacteria, and suggests a potential force for those introns to evolve into spliceosomal introns. PMID:29905149

  11. siRNA-loaded liposomes: Inhibition of encystment of Acanthamoeba and toxicity on the eye surface.

    Science.gov (United States)

    Faber, Kathrin; Zorzi, Giovanni K; Brazil, Nathalya T; Rott, Marilise B; Teixeira, Helder F

    2017-09-01

    Current treatments for Acanthamoeba keratitis are unspecific. Because of the presence of the resilient cyst form of the parasite, the infection is persistent. Silencing the key protein of cyst formation, glycogen phosphorylase, has shown potential for reducing encystment processes of the Acanthamoeba trophozoite. However, a suitable carrier to protect and deliver siRNA sequences is still needed. DOPE:DSPE-PEG liposomes were prepared by three different techniques and used to associate a therapeutic siRNA sequence. Liposomes prepared by film hydration followed by membrane extrusion were considered the most adequate ones with average size of 250 nm and zeta potential of +45 mV, being able to associate siRNA for at least 24 hr in culture medium. siRNA-liposomes could inhibit up to 66% of the encystment process. Cell viability studies demonstrated MTT reduction capacity higher than 80% after 3 hr incubation with this formulation. After 24 hr of incubation, LDH activity ranged for both the formulations from around 4% to 40%. In vivo tolerance studies in mice showed no macroscopic alteration in the eye structures up to 24 hr after eight administrations during 1 day. Histological studies showed regular tissue architecture without any morphological alteration. Overall, these results suggest that the formulations developed are a promising new strategy for the treatment of ocular keratitis caused by Acanthamoeba spp. © 2017 John Wiley & Sons A/S.

  12. Noncoding Subgenomic Flavivirus RNA Is Processed by the Mosquito RNA Interference Machinery and Determines West Nile Virus Transmission by Culex pipiens Mosquitoes

    NARCIS (Netherlands)

    Goertz, G.P.; Fros, J.J.; Miesen, P.; Vogels, C.B.F.; Bent, M.L. van der; Geertsema, C.; Koenraadt, C.J.M.; Rij, R.P. van; Oers, M.M. van; Pijlman, G.P.

    2016-01-01

    Flaviviruses, such as Zika virus, yellow fever virus, dengue virus, and West Nile virus (WNV), are a serious concern for human health. Flaviviruses produce an abundant noncoding subgenomic flavivirus RNA (sfRNA) in infected cells. sfRNA results from stalling of the host 5'-3' exoribonuclease

  13. Sodium arsenite-induced inhibition of cell proliferation is related to inhibition of IL-2 mRNA expression in mouse activated T cells

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Patricia; Acosta-Saavedra, Leonor C.; Calderon-Aranda, Emma S. [Centro de Investigacion y de Estudios Avanzados, CINVESTAV, Seccion Toxicologia, P.O. Box 14-740, Mexico, D.F. (Mexico); Goytia-Acevedo, Raquel C. [Universidad Juarez del Estado de Durango, Facultad de Medicina, Gomez Palacio, Durango (Mexico)

    2007-04-15

    A proposed mechanism for the As-induced inhibition of cell proliferation is the inhibition of IL-2 secretion. However, the effects of arsenite on IL-2 mRNA expression or on the ERK pathway in activated-T cells have not yet been described. We examined the effect of arsenite on IL-2 mRNA expression, cell activation and proliferation in PHA-stimulated murine lymphocytes. Arsenite (1 and 10 {mu}M) decreased IL-2 mRNA expression, IL-2 secretion and cell proliferation. Arsenite (10 {mu}M) strongly inhibited ERK-phosphorylation. However, the partial inhibition (50%) of IL-2 mRNA produced by 1 {mu}M, consistent with the effects on IL-2 secretion and cell proliferation, could not be explained by the inhibition of ERK-phosphorylation, which was not affected at this concentration. The inhibition of IL-2 mRNA expression caused by 1 {mu}M could be associated to effects on pathways located downstream or parallel to ERK. Arsenite also decreased early activation (surface CD69{sup +} expression) in both CD4{sup +} and CD8{sup +}, and decreased total CD8{sup +} count without significantly affecting CD4{sup +}, supporting that the cellular immune response mediated by cytotoxic T cells is an arsenic target. Thus, our results suggest that arsenite decreases IL-2 mRNA levels and T-cell activation and proliferation. However, further studies on the effects of arsenite on IL-2 gene transcription and IL-2 mRNA stability are needed. (orig.)

  14. Structural Basis for Specific Inhibition of tRNA Synthetase by an ATP Competitive Inhibitor

    OpenAIRE

    Fang, Pengfei; Han, Hongyan; Wang, Jing; Chen, Kaige; Chen, Xin; Guo, Min

    2015-01-01

    Pharmaceutical inhibitors of aminoacyl-tRNA synthetases demand high species and family specificity. The antimalarial ATP-mimetic cladosporin selectively inhibits P. falciparum LysRS (PfLysRS). How the binding to a universal ATP site achieves the specificity is unknown. Here we report 3 crystal structures of cladosporin with human LysRS, PfLysRS, and a Pf-like human LysRS mutant. In all 3 structures, cladosporin occupies the class defining ATP-binding pocket, replacing the adenosine portion of...

  15. Strand Analysis, a free online program for the computational identification of the best RNA interference (RNAi targets based on Gibbs free energy

    Directory of Open Access Journals (Sweden)

    Tiago Campos Pereira

    2007-01-01

    Full Text Available The RNA interference (RNAi technique is a recent technology that uses double-stranded RNA molecules to promote potent and specific gene silencing. The application of this technique to molecular biology has increased considerably, from gene function identification to disease treatment. However, not all small interfering RNAs (siRNAs are equally efficient, making target selection an essential procedure. Here we present Strand Analysis (SA, a free online software tool able to identify and classify the best RNAi targets based on Gibbs free energy (deltaG. Furthermore, particular features of the software, such as the free energy landscape and deltaG gradient, may be used to shed light on RNA-induced silencing complex (RISC activity and RNAi mechanisms, which makes the SA software a distinct and innovative tool.

  16. MicroRNA-155 Inhibition Promoted Wound Healing in Diabetic Rats.

    Science.gov (United States)

    Ye, Junna; Kang, Yutian; Sun, Xiaofang; Ni, Pengwen; Wu, Minjie; Lu, Shuliang

    2017-06-01

    Diabetes leads to amputation in approximately 15% to 20% of patients and is associated with high morbidity and mortality. Thus, improving the quality of wound healing in this condition is essential. Diabetes is associated with acute/chronic inflammation affecting all organs especially the foot, while, inhibition of microRNA-155 (miR-155) has been reported to improve or reduce inflammatory situation. However, the role of miR-155 inhibition in promoting diabetic wound healing is not clear. To further study the potential benefit of miR-155 inhibition, a study of male Sprague-Dawley rats was conducted and diabetes was induced by injection of streptozotocin. Real-time polymerase chain reaction (PCR), hematoxylin and eosin staining and immunohistochemistry were then performed. The PCR results confirmed that miR-155 expression was lower after miR-155 inhibition on days 3, 7, and 13 (all Ps healing rate between the normal glucose group (N group), diabetic PBS group (PBS group) and the topical miR-155 inhibitor group was compared. Faster healing of cutaneous wounds was observed in the miR-155 inhibitor group than in the PBS group and normal glucose group ( P healing of diabetic foot wounds.

  17. Expression profiling and cross-species RNA interference (RNAi of desiccation-induced transcripts in the anhydrobiotic nematode Aphelenchus avenae

    Directory of Open Access Journals (Sweden)

    Culleton Bridget A

    2010-01-01

    Full Text Available Abstract Background Some organisms can survive extreme desiccation by entering a state of suspended animation known as anhydrobiosis. The free-living mycophagous nematode Aphelenchus avenae can be induced to enter anhydrobiosis by pre-exposure to moderate reductions in relative humidity (RH prior to extreme desiccation. This preconditioning phase is thought to allow modification of the transcriptome by activation of genes required for desiccation tolerance. Results To identify such genes, a panel of expressed sequence tags (ESTs enriched for sequences upregulated in A. avenae during preconditioning was created. A subset of 30 genes with significant matches in databases, together with a number of apparently novel sequences, were chosen for further study. Several of the recognisable genes are associated with water stress, encoding, for example, two new hydrophilic proteins related to the late embryogenesis abundant (LEA protein family. Expression studies confirmed EST panel members to be upregulated by evaporative water loss, and the majority of genes was also induced by osmotic stress and cold, but rather fewer by heat. We attempted to use RNA interference (RNAi to demonstrate the importance of this gene set for anhydrobiosis, but found A. avenae to be recalcitrant with the techniques used. Instead, therefore, we developed a cross-species RNAi procedure using A. avenae sequences in another anhydrobiotic nematode, Panagrolaimus superbus, which is amenable to gene silencing. Of 20 A. avenae ESTs screened, a significant reduction in survival of desiccation in treated P. superbus populations was observed with two sequences, one of which was novel, while the other encoded a glutathione peroxidase. To confirm a role for glutathione peroxidases in anhydrobiosis, RNAi with cognate sequences from P. superbus was performed and was also shown to reduce desiccation tolerance in this species. Conclusions This study has identified and characterised the

  18. Identification of constrained peptides that bind to and preferentially inhibit the activity of the hepatitis C viral RNA-dependent RNA polymerase

    International Nuclear Information System (INIS)

    Amin, Anthony; Zaccardi, Joe; Mullen, Stanley; Olland, Stephane; Orlowski, Mark; Feld, Boris; Labonte, Patrick; Mak, Paul

    2003-01-01

    A class of disulfide constrained peptides containing a core motif FPWG was identified from a screen of phage displayed library using the HCV RNA-dependent RNA polymerase (NS5B) as a bait. Surface plasmon resonance studies showed that three highly purified synthetic constrained peptides bound to immobilized NS5B with estimated K d values ranging from 30 to 60 μM. In addition, these peptides inhibited the NS5B activity in vitro with IC 50 ranging from 6 to 48 μM, whereas in contrast they had no inhibitory effect on the enzymatic activities of calf thymus polymerase α, human polymerase β, RSV polymerase, and HIV reverse transcriptase in vitro. Two peptides demonstrated conformation-dependent inhibition since their synthetic linear versions were not inhibitory in the NS5B assay. A constrained peptide with the minimum core motif FPWG retained selective inhibition of NS5B activity with an IC 50 of 50 μM. Alanine scan analyses of a representative constrained peptide, FPWGNTW, indicated that residues F1 and W7 were critical for the inhibitory effect of this peptide, although residues P2 and N5 had some measurable inhibitory effect as well. Further analyses of the mechanism of inhibition indicated that these peptides inhibited the formation of preelongation complexes required for the elongation reaction. However, once the preelongation complex was formed, its activity was refractory to peptide inhibition. Furthermore, the constrained peptide FPWGNTW inhibited de novo initiated RNA synthesis by NS5B from a poly(rC) template. These data indicate that the peptides confer selective inhibition of NS5B activity by binding to the enzyme and perturbing an early step preceding the processive elongation step of RNA synthesis

  19. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    International Nuclear Information System (INIS)

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-01-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  20. Culture medium, gas atmosphere and MAPK inhibition affect regulation of RNA-binding protein targets during mouse preimplantation development.

    Science.gov (United States)

    Calder, Michele D; Watson, Patricia H; Watson, Andrew J

    2011-11-01

    During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos cultured in Whitten's medium compared with embryos cultured in KSOMaa, and Gclc mRNA was elevated under high-oxygen conditions. Inhibition of the p38 MAPK pathway reduced Slc7a1 mRNA expression while inhibition of ERK increased Slc2a1 mRNA expression. The half-lives of the potential RBP mRNA targets are not regulated in parallel; Slc2a1 mRNA displayed the longest half-life. Our results indicate that mRNAs and proteins encoding five RBPs are present during preimplantation development and more importantly, demonstrate that expression of RBP target mRNAs are regulated by culture medium, gas atmosphere and MAPK pathways.

  1. Inhibition by Siomycin and Thiostrepton of Both Aminoacyl-tRNA and Factor G Binding to Ribosomes

    Science.gov (United States)

    Ll, Juan Modole; Cabrer, Bartolomé; Parmeggiani, Andrea; Azquez, David V

    1971-01-01

    Siomycin, a peptide antibiotic that interacts with the 50S ribosomal subunit and inhibits binding of factor G, is shown also to inhibit binding of aminoacyl-tRNA; however, it does not impair binding of fMet-tRNA and completion of the initiation complex. Moreover, unlike other inhibitors of aminoacyl-tRNA binding (tetracycline, sparsomycin, and streptogramin A), siomycin completely abolishes the GTPase activity associated with the binding of aminoacyl-tRNA catalyzed by factor Tu. A single-site interaction of siomycin appears to be responsible for its effect on both the binding of the aminoacyl-tRNA-Tu-GTP complex and that of factor G. PMID:4331558

  2. Inhibition of protein kinase A activity interferes with long-term, but not short-term, memory of conditioned taste aversions.

    Science.gov (United States)

    Koh, Ming Teng; Thiele, Todd E; Bernstein, Ilene L

    2002-12-01

    The present experiments examined whether inhibition of cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) activity interferes with conditioned taste aversion (CTA) memories. Rats were centrally infused with the selective PKA inhibitor Rp-adenosine 3',5'-cyclic monophosphothioate triethylamine (Rp-cAMPS) before conditioning. Direct infusions of Rp-cAMPS into the amygdala showed no interference with short-term memory but did show significant attenuation of long-term memory and more rapid extinction. Results suggest that PKA activity is involved in the consolidation of long-term memory of CTAs, and that the amygdala may be 1 site that is important for this activity.

  3. The ability to manage self-proposed projects between 1;3 and 2;0 years old: a study of inhibition and resistance to interference

    OpenAIRE

    Estanislao Pastor-Mallol; Edith Santó-Rañé

    2015-01-01

    This study examines very young children's ability to manage self-proposed projects by using the inhibitory function and resistance to interference. In a natural environment and using an observational method, we conducted a longitudinal study of a sample observed at 1;3, 1;6, 1;9 and 2;0 years old. The research was divided into two studies which followed different procedures and looked at the projects carried out, the interferences produced and the functioning of inhibition. We observed signif...

  4. Simultaneous inhibition of multiple oncogenic miRNAs by a multi-potent microRNA sponge.

    Science.gov (United States)

    Jung, Jaeyun; Yeom, Chanjoo; Choi, Yeon-Sook; Kim, Sinae; Lee, EunJi; Park, Min Ji; Kang, Sang Wook; Kim, Sung Bae; Chang, Suhwan

    2015-08-21

    The roles of oncogenic miRNAs are widely recognized in many cancers. Inhibition of single miRNA using antagomiR can efficiently knock-down a specific miRNA. However, the effect is transient and often results in subtle phenotype, as there are other miRNAs contribute to tumorigenesis. Here we report a multi-potent miRNA sponge inhibiting multiple miRNAs simultaneously. As a model system, we targeted miR-21, miR-155 and miR-221/222, known as oncogenic miRNAs in multiple tumors including breast and pancreatic cancers. To achieve efficient knockdown, we generated perfect and bulged-matched miRNA binding sites (MBS) and introduced multiple copies of MBS, ranging from one to five, in the multi-potent miRNA sponge. Luciferase reporter assay showed the multi-potent miRNA sponge efficiently inhibited 4 miRNAs in breast and pancreatic cancer cells. Furthermore, a stable and inducible version of the multi-potent miRNA sponge cell line showed the miRNA sponge efficiently reduces the level of 4 target miRNAs and increase target protein level of these oncogenic miRNAs. Finally, we showed the miRNA sponge sensitize cells to cancer drug and attenuate cell migratory activity. Altogether, our study demonstrates the multi-potent miRNA sponge is a useful tool to examine the functional impact of simultaneous inhibition of multiple miRNAs and proposes a therapeutic potential.

  5. α-Fetoprotein promoter-driven Cre/LoxP-switched RNA interference for hepatocellular carcinoma tissue-specific target therapy.

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    Yuan-Fei Peng

    Full Text Available RNA interference (RNAi has recently emerged as a potential treatment modality for hepatocellular carcinoma (HCC therapy, but the lack of cellular targets and sustained efficacy limits its application. The purpose of this study is to develop an HCC tissue-specific RNAi system and investigate its possibility for HCC treatment.Two different HCC-specific RNAi systems in which therapeutic miRNA or shRNA against target gene (Beclin 1 was directly or indirectly driven by alpha-fetoprotein promoter (AFP-miRNA and AFP-Cre/LoxP-shRNA were constructed. Human HCC cell lines (HepG2, Hep3B and HCCLM3 and non-HCC cell lines (L-02, Hela and SW1116 were infected with the systems. The effectiveness and tissue-specificity of the systems were examined by Q-PCR and western blot analysis. The efficacy of the systems was further tested in mouse model of HCC by intravenous or intratumoral administration. The feasibility of the system for HCC treatment was evaluated by applying the system as adjuvant therapy to enhance sorafenib treatment. An AFP-Cre/LoxP-shRNA system targeting Atg5 gene (AFP-Cre/LoxP-shRNA-Atg5 was constructed and its efficacy in sensitizing HCC cells (MHCC97L/PLC to sorafenib treatment was examined by apoptosis assay in vitro and tumorigenesis assay in vivo.The AFP-miRNA system could silence target gene (Beclin 1 but required a high titer which was lethal to target cells. The AFP-Cre/LoxP-shRNA system could efficiently knockdown target gene while maintain high HCC specificity. Intratumoral injection of the AFP-Cre/LoxP-shRNA system could efficiently silence target gene (Beclin 1 in vivo while intravenous administration could not. The AFP-Cre/LoxP-shRNA system target Atg5 gene could significantly sensitize MHCC97L/PLC cells to sorafenib-induced apoptosis in vitro and tumor growth suppression in vivo.An efficient HCC tissue-specific RNAi system (AFP-Cre/LoxP-shRNA was successfully established. The system provides a usable tool for HCC-specific RNAi

  6. Inhibition of KLF7-Targeting MicroRNA 146b Promotes Sciatic Nerve Regeneration.

    Science.gov (United States)

    Li, Wen-Yuan; Zhang, Wei-Ting; Cheng, Yong-Xia; Liu, Yan-Cui; Zhai, Feng-Guo; Sun, Ping; Li, Hui-Ting; Deng, Ling-Xiao; Zhu, Xiao-Feng; Wang, Ying

    2018-06-01

    A previous study has indicated that Krüppel-like factor 7 (KLF7), a transcription factor that stimulates Schwann cell (SC) proliferation and axonal regeneration after peripheral nerve injury, is a promising therapeutic transcription factor in nerve injury. We aimed to identify whether inhibition of microRNA-146b (miR-146b) affected SC proliferation, migration, and myelinated axon regeneration following sciatic nerve injury by regulating its direct target KLF7. SCs were transfected with miRNA lentivirus, miRNA inhibitor lentivirus, or KLF7 siRNA lentivirus in vitro. The expression of miR146b and KLF7, as well as SC proliferation and migration, were subsequently evaluated. In vivo, an acellular nerve allograft (ANA) followed by injection of GFP control vector or a lentiviral vector encoding an miR-146b inhibitor was used to assess the repair potential in a model of sciatic nerve gap. miR-146b directly targeted KLF7 by binding to the 3'-UTR, suppressing KLF7. Up-regulation of miR-146b and KLF7 knockdown significantly reduced the proliferation and migration of SCs, whereas silencing miR-146b resulted in increased proliferation and migration. KLF7 protein was localized in SCs in which miR-146b was expressed in vivo. Similarly, 4 weeks after the ANA, anti-miR-146b increased KLF7 and its target gene nerve growth factor cascade, promoting axonal outgrowth. Closer analysis revealed improved nerve conduction and sciatic function index score, and enhanced expression of neurofilaments, P0 (anti-peripheral myelin), and myelinated axon regeneration. Our findings provide new insight into the regulation of KLF7 by miR-146b during peripheral nerve regeneration and suggest a potential therapeutic strategy for peripheral nerve injury.

  7. Specific down-regulation of XIAP with RNA interference enhances the sensitivity of canine tumor cell-lines to TRAIL and doxorubicin

    Directory of Open Access Journals (Sweden)

    Rothuizen Jan

    2006-09-01

    Full Text Available Abstract Background Apoptosis resistance occurs in various tumors. The anti-apoptotic XIAP protein is responsible for inhibiting apoptosis by reducing caspase-3 activation. Our aim is to evaluate whether RNA inhibition against XIAP increases the sensitivity of canine cell-lines for chemotherapeutics such as TRAIL and doxorubicin. We used small interfering RNA's (siRNA directed against XIAP in three cell-lines derived from bile-duct epithelia (BDE, mammary carcinoma (P114, and osteosarcoma (D17. These cell-lines represent frequently occurring canine cancers and are highly comparable to their human counterparts. XIAP down-regulation was measured by means of quantitative PCR (Q-PCR and Western blotting. The XIAP depleted cells were treated with a serial dilution of TRAIL or doxorubicin and compared to mock- and nonsense-treated controls. Viability was measured with a MTT assay. Results All XIAP siRNA treated cell-lines showed a mRNA down-regulation over 80 percent. Western blot analysis confirmed mRNA measurements. No compensatory effect of IAP family members was seen in XIAP depleted cells. The sensitivity of XIAP depleted cells for TRAIL was highest in BDE cells with an increase in the ED50 of 14-fold, compared to mock- and nonsense-treated controls. The sensitivity of P114 and D17 cell-lines increased six- and five-fold, respectively. Doxorubicin treatment in XIAP depleted cells increased sensitivity in BDE cells more than eight-fold, whereas P114 and D17 cell-lines showed an increase in sensitivity of three- and five-fold, respectively. Conclusion XIAP directed siRNA's have a strong sensitizing effect on TRAIL-reduced cell-viability and a smaller but significant effect with the DNA damaging drug doxorubicin. The increase in efficacy of chemotherapeutics with XIAP depletion provides the rationale for the use of XIAP siRNA's in insensitive canine tumors.

  8. Cas5d Protein Processes Pre-crRNA and Assembles into a Cascade-like Interference Complex in Subtype I-C/Dvulg CRISPR-Cas System

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ki Hyun; Haitjema, Charles; Liu, Xueqi; Ding, Fran; Wang, Hongwei; DeLisa, Matthew P.; Ke, Ailong (Yale); (Cornell); (Tsinghua)

    2012-10-10

    Clustered regularly interspaced short palindromic repeats (CRISPRs), together with an operon of CRISPR-associated (Cas) proteins, form an RNA-based prokaryotic immune system against exogenous genetic elements. Cas5 family proteins are found in several type I CRISPR-Cas systems. Here, we report the molecular function of subtype I-C/Dvulg Cas5d from Bacillus halodurans. We show that Cas5d cleaves pre-crRNA into unit length by recognizing both the hairpin structure and the 3 single stranded sequence in the CRISPR repeat region. Cas5d structure reveals a ferredoxin domain-based architecture and a catalytic triad formed by Y46, K116, and H117 residues. We further show that after pre-crRNA processing, Cas5d assembles with crRNA, Csd1, and Csd2 proteins to form a multi-sub-unit interference complex similar to Escherichia coli Cascade (CRISPR-associated complex for antiviral defense) in architecture. Our results suggest that formation of a crRNA-presenting Cascade-like complex is likely a common theme among type I CRISPR subtypes.

  9. Identification of an Arabidopsis thaliana protein that binds to tomato mosaic virus genomic RNA and inhibits its multiplication

    International Nuclear Information System (INIS)

    Fujisaki, Koki; Ishikawa, Masayuki

    2008-01-01

    The genomic RNAs of positive-strand RNA viruses carry RNA elements that play positive, or in some cases, negative roles in virus multiplication by interacting with viral and cellular proteins. In this study, we purified Arabidopsis thaliana proteins that specifically bind to 5' or 3' terminal regions of tomato mosaic virus (ToMV) genomic RNA, which contain important regulatory elements for translation and RNA replication, and identified these proteins by mass spectrometry analyses. One of these host proteins, named BTR1, harbored three heterogeneous nuclear ribonucleoprotein K-homology RNA-binding domains and preferentially bound to RNA fragments that contained a sequence around the initiation codon of the 130K and 180K replication protein genes. The knockout and overexpression of BTR1 specifically enhanced and inhibited, respectively, ToMV multiplication in inoculated A. thaliana leaves, while such effect was hardly detectable in protoplasts. These results suggest that BTR1 negatively regulates the local spread of ToMV

  10. Inhibition of post-transcriptional RNA processing by CDK inhibitors and its implication in anti-viral therapy.

    Directory of Open Access Journals (Sweden)

    Jitka Holcakova

    Full Text Available Cyclin-dependent kinases (CDKs are key regulators of the cell cycle and RNA polymerase II mediated transcription. Several pharmacological CDK inhibitors are currently in clinical trials as potential cancer therapeutics and some of them also exhibit antiviral effects. Olomoucine II and roscovitine, purine-based inhibitors of CDKs, were described as effective antiviral agents that inhibit replication of a broad range of wild type human viruses. Olomoucine II and roscovitine show high selectivity for CDK7 and CDK9, with important functions in the regulation of RNA polymerase II transcription. RNA polymerase II is necessary for viral transcription and following replication in cells. We analyzed the effect of inhibition of CDKs by olomoucine II on gene expression from viral promoters and compared its effect to widely-used roscovitine. We found that both roscovitine and olomoucine II blocked the phosphorylation of RNA polymerase II C-terminal domain. However the repression of genes regulated by viral promoters was strongly dependent on gene localization. Both roscovitine and olomoucine II inhibited expression only when the viral promoter was not integrated into chromosomal DNA. In contrast, treatment of cells with genome-integrated viral promoters increased their expression even though there was decreased phosphorylation of the C-terminal domain of RNA polymerase II. To define the mechanism responsible for decreased gene expression after pharmacological CDK inhibitor treatment, the level of mRNA transcription from extrachromosomal DNA was determined. Interestingly, our results showed that inhibition of RNA polymerase II C-terminal domain phosphorylation increased the number of transcribed mRNAs. However, some of these mRNAs were truncated and lacked polyadenylation, which resulted in decreased translation. These results suggest that phosphorylation of RNA polymerase II C-terminal domain is critical for linking transcription and posttrancriptional

  11. MicroRNA-223 Targeting STIM1 Inhibits the Biological Behavior of Breast Cancer

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    Yanfang Yang

    2018-01-01

    Full Text Available Background/Aims: To investigate the cellular effects and clinical significance of microRNA-223 (miR-223 in breast cancer by targeting stromal interaction molecule1 (STIM1. Methods: Breast cancer cell lines (T47D, MCF-7, SKB-R3, MDA-MB-231 and MDA-MB-435 and a normal breast epithelial cell line (MCF-10A were prepared for this study. MiR-223 mimics, anti-miR-223 and pcDNA 3.1-STIM1 were transiently transfected into cancer cells independently or together, and then RT-qPCR was performed to detect the expressions of miR-223 and STIM1 mRNA, dual-luciferase reporter assay was conducted to examine the effects of miR-223 on STIM1, Western blotting was used to measure the expressions of the STIM1 proteins, MTT and Trans-well assays were performed to detect cell proliferation and invasion. Finally, the correlation of miR-223 and STIM1 was investigated by detecting with ISH and IHC in breast cancer specimens or the corresponding adjacent normal tissues. Results: Compared with normal cells and tissues, breast cancer tissues and cells exhibited significantly lower expression of miR-223, but higher expression of STIM1. MiR-223 could inhibit the proliferation and invasiveness of breast cancer cells by negatively regulating the expressions of STIM1. Reimplantation with STIM1 partially rescued the miRNA-223-induced inhibition of breast cancer cells. Clinical data revealed that high expression of STIM1 and miR-223 was respectively detrimental and beneficial factor impacting patient’s disease-free survival (DFS rather than overall survival (OS. Moreover, Pearson correlation analysis also confirmed that STIM1 was inversely correlated with miR-223. Conclusion: MiR-223 inhibits the proliferation and invasion of breast cancer by targeting STIM1. The miR-223/STIM1 axis could possibly be a potential therapeutic target for treating breast cancer patients.

  12. Large Intergenic Non-coding RNA-RoR Inhibits Aerobic Glycolysis of Glioblastoma Cells via Akt Pathway

    Science.gov (United States)

    Li, Yong; He, Zhi-Cheng; Liu, Qing; Zhou, Kai; Shi, Yu; Yao, Xiao-Hong; Zhang, Xia; Kung, Hsiang-Fu; Ping, Yi-Fang; Bian, Xiu-Wu

    2018-01-01

    Reprogramming energy metabolism is a hallmark of malignant tumors, including glioblastoma (GBM). Aerobic glycolysis is often utilized by tumor cells to maintain survival and proliferation. However, the underlying mechanisms of aerobic glycolysis in GBM remain elusive. Herein, we demonstrated that large intergenic non-coding RNA-RoR (LincRNA-RoR) functioned as a critical suppressor to inhibit the aerobic glycolysis and viability of GBM cells. We found that LincRNA-RoR was markedly reduced in GBM tissues compared with adjacent non-tumor tissues from 10 cases of GBM patients. Consistently, LincRNA-RoR expression in GBM cells was significantly lower than that in normal glial cells. The aerobic glycolysis of GBM cells, as determined by the measurement of glucose uptake and lactate production, was impaired by LincRNA-RoR overexpression. Mechanistically, LincRNA-RoR inhibited the expression of Rictor, the key component of mTORC2 (mammalian target of rapamycin complex 2), to suppress the activity of Akt pathway and impair the expression of glycolytic effectors, including Glut1, HK2, PKM2 and LDHA. Finally, enforced expression of LincRNA-RoR reduced the proliferation of GBM cells in vitro, restrained tumor growth in vivo, and repressed the expression of glycolytic molecules in GBM xenografts. Collectively, our results underscore LincRNA-RoR as a new suppressor of GBM aerobic glycolysis with therapeutic potential. PMID:29581766

  13. Inhibition of Poliovirus-Induced Cleavage of Cellular Protein PCBP2 Reduces the Levels of Viral RNA Replication

    Science.gov (United States)

    Chase, Amanda J.; Daijogo, Sarah

    2014-01-01

    ABSTRACT Due to their small genome size, picornaviruses must utilize host proteins to mediate cap-independent translation and viral RNA replication. The host RNA-binding protein poly(rC) binding protein 2 (PCBP2) is involved in both processes in poliovirus infected cells. It has been shown that the viral proteinase 3CD cleaves PCBP2 and contributes to viral translation inhibition. However, cleaved PCBP2 remains active in viral RNA replication. This would suggest that both cleaved and intact forms of PCBP2 have a role in the viral RNA replication cycle. The picornavirus genome must act as a template for both translation and RNA replication. However, a template that is actively being translated cannot function as a template for RNA replication, suggesting that there is a switch in template usage from translation to RNA replication. We demonstrate that the cleavage of PCBP2 by the poliovirus 3CD proteinase is a necessary step for efficient viral RNA replication and, as such, may be important for mediating a switch in template usage from translation to RNA replication. IMPORTANCE Poliovirus, like all positive-strand RNA viruses that replicate in the cytoplasm of eukaryotic cells, uses its genomic RNA as a template for both viral protein synthesis and RNA replication. Given that these processes cannot occur simultaneously on the same template, poliovirus has evolved a mechanism(s) to facilitate the switch from using templates for translation to using them for RNA synthesis. This study explores one possible scenario for how the virus alters the functions of a host cell RNA binding protein to mediate, in part, this important transition. PMID:24371074

  14. A Conserved Target Site in HIV-1 Gag RNA is Accessible to Inhibition by Both an HDV Ribozyme and a Short Hairpin RNA

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    Robert J Scarborough

    2014-01-01

    Full Text Available Antisense-based molecules targeting HIV-1 RNA have the potential to be used as part of gene or drug therapy to treat HIV-1 infection. In this study, HIV-1 RNA was screened to identify more conserved and accessible target sites for ribozymes based on the hepatitis delta virus motif. Using a quantitative screen for effects on HIV-1 production, we identified a ribozyme targeting a highly conserved site in the Gag coding sequence with improved inhibitory potential compared to our previously described candidates targeting the overlapping Tat/Rev coding sequence. We also demonstrate that this target site is highly accessible to short hairpin directed RNA interference, suggesting that it may be available for the binding of antisense RNAs with different modes of action. We provide evidence that this target site is structurally conserved in diverse viral strains and that it is sufficiently different from the human transcriptome to limit off-target effects from antisense therapies. We also show that the modified hepatitis delta virus ribozyme is more sensitive to a mismatch in its target site compared to the short hairpin RNA. Overall, our results validate the potential of a new target site in HIV-1 RNA to be used for the development of antisense therapies.

  15. siRNA inhibition of telomerase enhances the anti-cancer effect of doxorubicin in breast cancer cells

    International Nuclear Information System (INIS)

    Dong, Xuejun; Liu, Anding; Zer, Cindy; Feng, Jianguo; Zhen, Zhuan; Yang, Mingfeng; Zhong, Li

    2009-01-01

    Doxorubicin is an effective breast cancer drug but is hampered by a severe, dose-dependent toxicity. Concomitant administration of doxorubicin and another cancer drug may be able to sensitize tumor cells to the cytotoxicity of doxorubicin and lowers the therapeutic dosage. In this study, we examined the combined effect of low-dose doxorubicin and siRNA inhibition of telomerase on breast cancer cells. We found that when used individually, both treatments were rapid and potent apoptosis inducers; and when the two treatments were combined, we observed an enhanced and sustained apoptosis induction in breast cancer cells. siRNA targeting the mRNA of the protein component of telomerase, the telomerase reverse transcriptase (hTERT), was transfected into two breast cancer cell lines. The siRNA inhibition was confirmed by RT-PCR and western blot on hTERT mRNA and protein levels, respectively, and by measuring the activity level of telomerase using the TRAP assay. The effect of the hTERT siRNA on the tumorigenicity of the breast cancer cells was also studied in vivo by injection of the siRNA-transfected breast cancer cells into nude mice. The effects on cell viability, apoptosis and senescence of cells treated with hTERT siRNA, doxorubicin, and the combined treatment of doxorubicin and hTERT siRNA, were examined in vitro by MTT assay, FACS and SA-β-galactosidase staining. The hTERT siRNA effectively knocked down the mRNA and protein levels of hTERT, and reduced the telomerase activity to 30% of the untreated control. In vivo, the tumors induced by the hTERT siRNA-transfected cells were of reduced sizes, indicating that the hTERT siRNA also reduced the tumorigenic potential of the breast cancer cells. The siRNA treatment reduced cell viability by 50% in breast cancer cells within two days after transfection, while 0.5 μM doxorubicin treatment had a comparable effect but with a slower kinetics. The combination of hTERT siRNA and 0.5 μM doxorubicin killed twice as many

  16. RNA interference suppression of A100A4 reduces the growth and metastatic phenotype of human renal cancer cells via NF-kB-dependent MMP-2 and bcl-2 pathway.

    Science.gov (United States)

    Yang, X-C; Wang, X; Luo, L; Dong, D-H; Yu, Q-C; Wang, X-S; Zhao, K

    2013-06-01

    S100A4 is a well established marker and mediator of metastatic disease, but the exact mechanisms responsible for the metastasis promoting effects are less well defined. We tested a hypothesis that the S100A4 gene plays a role in the proliferation and invasiveness of human renal cancer cells (RCC) and may be associated with its metastatic spread. The small interference RNA vector pcDNA3.1-S100A4 siRNA was transfected in to the human renal cancer cell lines ACHN, Ketr-3, OS-RC-2, CaKi-2 and HTB-47, then treated with ABT-737 or BB94. Cell apoptosis and cell viability was detected by flow cytometry and MTT assay. Matrigel was used for cell motility and invasion assay. MMP-2, bcl-2 and S100A4 was detected by RT-PCR and western blot assay. NF-kB subunit p65 activity was detected by confocal microscopy assay. We then determine the effect S100A4 sliencing on tumor growth, lung metastasis development in vivo. Immunohistochemistry was used to detected the expression of S100A4, bcl-2, MMP-2, p65 and CD31. S100A4 silencing in ACHN cells by RNA interference significantly inhibited NF-kB and NF-kB-mediated MMP-2 and bcl-2 activation and cellular migration, proliferation, and promoted apoptosis. Furthermore, re-expression of S100A4 in S100A4-siRNA-transfected ACHN cells by transient S100A4 cDNA transfection restored the NF-kB and NF-kB-mediated MMP-2 and bcl-2 activation and their high migratory and cellular proliferative ability. An inhibitor ABT-737 (the Bcl-2 antagonist targets Bcl-2) against Bcl-2 suppressed cellular proliferation and promoted apoptosis induced by S100A4 re-expression in S100A4-siRNA-transfected ACHN cells. A inhibitor BB94 against MMPs to neutralize MMP-2 protein suppressed cellular invasion and migration induced by S100A4 re-expression in S100A4-siRNA-transfected ACHN cells. In the prevention model, S100A4 silencing inhibited primary tumor growth by (tumor weight) (76 ± 8%) and (tumor volum) (78 ± 4%) respectively and promoted apoptosis and the formation

  17. MicroRNA-133a Inhibits Osteosarcoma Cells Proliferation and Invasion via Targeting IGF-1R

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    Guangnan Chen

    2016-02-01

    Full Text Available Background/Aims: MicroRNAs (miRNAs are a class of small noncoding RNAs that regulate gene expression by repressing translation or cleaving RNA transcripts in a sequence-specific manner. Downregulated microRNAs and their roles in cancer development have attracted much attention. A growing body of evidence showed that microRNA-133a (miR-133a has inhibitory effects on cell proliferation, migration, invasion, and metastasis of osteosarcoma. Methods: MiR-133a expression in human osteosarcoma cell lines and human normal osteoblastic cell line hFOB was investigated by real-time PCR (RT-PCR. The role of miR-133a in human osteosarcoma growth and invasion was assessed in cell lines in vitro and in vivo. Then, luciferase reporter assay validated IGF-1R as a downstream and functional target of miR-133a, and functional studies revealed that the anti-tumor effect of miR-133a was probably due to targeting and repressing of IGF-1R expression. Results: MiR-133a was lower expressed in human osteosarcoma cell lines than human normal osteoblastic cell line hFOB and its effect on inhibiting proliferation, invasion and metastasis is mediated by its direct interaction with the IGF-1R. Furthermore, the tumour-suppressive function of miR-133a probably contributed to inhibiting the activation AKT and ERK signaling pathway. Conclusion: MiR-133a suppresses osteosarcoma progression and metastasis by targeting IGF-1R in human osteosarcoma cells, providing a novel candidate prognostic factor and a potential anti-metastasis therapeutic target in osteosarcoma.

  18. Targeting long non-coding RNA-TUG1 inhibits tumor growth and angiogenesis in hepatoblastoma.

    Science.gov (United States)

    Dong, R; Liu, G-B; Liu, B-H; Chen, G; Li, K; Zheng, S; Dong, K-R

    2016-06-30

    Hepatoblastoma is the most common liver tumor of early childhood, which is usually characterized by unusual hypervascularity. Recently, long non-coding RNAs (lncRNA) have emerged as gene regulators and prognostic markers in several cancers, including hepatoblastoma. We previously reveal that lnRNA-TUG1 is upregulated in hepatoblastoma specimens by microarray analysis. In this study, we aim to elucidate the biological and clinical significance of TUG1 upregulation in hepatoblastoma. We show that TUG1 is significantly upregulated in human hepatoblastoma specimens and metastatic hepatoblastoma cell lines. TUG1 knockdown inhibits tumor growth and angiogenesis in vivo, and decreases hepatoblastoma cell viability, proliferation, migration, and invasion in vitro. TUG1, miR-34a-5p, and VEGFA constitutes to a regulatory network, and participates in regulating hepatoblastoma cell function, tumor progression, and tumor angiogenesis. Overall, our findings indicate that TUG1 upregulation contributes to unusual hypervascularity of hepatoblastoma. TUG1 is a promising therapeutic target for aggressive, recurrent, or metastatic hepatoblastoma.

  19. Structural basis of malaria parasite lysyl-tRNA synthetase inhibition by cladosporin.

    Science.gov (United States)

    Khan, Sameena; Sharma, Arvind; Belrhali, Hassan; Yogavel, Manickam; Sharma, Amit

    2014-06-01

    Malaria parasites inevitably develop drug resistance to anti-malarials over time. Hence the immediacy for discovering new chemical scaffolds to include in combination malaria drug therapy. The desirable attributes of new chemotherapeutic agents currently include activity against both liver and blood stage malaria parasites. One such recently discovered compound called cladosporin abrogates parasite growth via inhibition of Plasmodium falciparum lysyl-tRNA synthetase (PfKRS), an enzyme central to protein translation. Here, we present crystal structure of ternary PfKRS-lysine-cladosporin (PfKRS-K-C) complex that reveals cladosporin's remarkable ability to mimic the natural substrate adenosine and thereby colonize PfKRS active site. The isocoumarin fragment of cladosporin sandwiches between critical adenine-recognizing residues while its pyran ring fits snugly in the ribose-recognizing cavity. PfKRS-K-C structure highlights ample space within PfKRS active site for further chemical derivatization of cladosporin. Such derivatives may be useful against additional human pathogens that retain high conservation in cladosporin chelating residues within their lysyl-tRNA synthetase.

  20. CUP promotes deadenylation and inhibits decapping of mRNA targets

    Science.gov (United States)

    Igreja, Catia; Izaurralde, Elisa

    2011-01-01

    CUP is an eIF4E-binding protein (4E-BP) that represses the expression of specific maternal mRNAs prior to their posterior localization. Here, we show that CUP employs multiple mechanisms to repress the expression of target mRNAs. In addition to inducing translational repression, CUP maintains mRNA targets in a repressed state by promoting their deadenylation and protects deadenylated mRNAs from further degradation. Translational repression and deadenylation are independent of eIF4E binding and require both the middle and C-terminal regions of CUP, which collectively we termed the effector domain. This domain associates with the deadenylase complex CAF1–CCR4–NOT and decapping activators. Accordingly, in isolation, the effector domain is a potent trigger of mRNA degradation and promotes deadenylation, decapping and decay. However, in the context of the full-length CUP protein, the decapping and decay mediated by the effector domain are inhibited, and target mRNAs are maintained in a deadenylated, repressed form. Remarkably, an N-terminal regulatory domain containing a noncanonical eIF4E-binding motif is required to protect CUP-associated mRNAs from decapping and further degradation, suggesting that this domain counteracts the activity of the effector domain. Our findings indicate that the mode of action of CUP is more complex than previously thought and provide mechanistic insight into the regulation of mRNA expression by 4E-BPs. PMID:21937713

  1. The stress granule component TIA-1 binds tick-borne encephalitis virus RNA and is recruited to perinuclear sites of viral replication to inhibit viral translation.

    Science.gov (United States)

    Albornoz, Amelina; Carletti, Tea; Corazza, Gianmarco; Marcello, Alessandro

    2014-06-01

    Flaviviruses are a major cause of disease in humans and animals worldwide. Tick-borne encephalitis virus (TBEV) is the most important arthropod-borne flavivirus endemic in Europe and is the etiological agent of tick-borne encephalitis, a potentially fatal infection of the central nervous system. However, the contributions of host proteins during TBEV infection are poorly understood. In this work, we investigate the cellular protein TIA-1 and its cognate factor TIAR, which are stress-induced RNA-binding proteins involved in the repression of initiation of translation of cellular mRNAs and in the formation of stress granules. We show that TIA-1 and TIAR interact with viral RNA in TBEV-infected cells. During TBEV infection, cytoplasmic TIA-1 and TIAR are recruited at sites of viral replication with concomitant depletion from stress granules. This effect is specific, since G3BP1, another component of these cytoplasmic structures, remains localized to stress granules. Moreover, heat shock induction of stress granules containing TIA-1, but not G3BP1, is inhibited in TBEV-infected cells. Infection of cells depleted of TIA-1 or TIAR by small interfering RNA (siRNA) or TIA-1(-/-) mouse fibroblasts, leads to a significant increase in TBEV extracellular infectivity. Interestingly, TIAR(-/-) fibroblasts show the opposite effect on TBEV infection, and this phenotype appears to be related to an excess of TIA-1 in these cells. Taking advantage of a TBE-luciferase replicon system, we also observed increased luciferase activity in TIA-1(-/-) mouse fibroblasts at early time points, consistent with TIA-1-mediated inhibition at the level of the first round of viral translation. These results indicate that, in response to TBEV infection, TIA-1 is recruited to sites of virus replication to bind TBEV RNA and modulate viral translation independently of stress granule (SG) formation. This study (i) extends previous work that showed TIA-1/TIAR recruitment at sites of flavivirus replication

  2. Impact of Subolesin and Cystatin Knockdown by RNA Interference in Adult Female Haemaphysalis longicornis (Acari: Ixodidae on Blood Engorgement and Reproduction

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    Md. Khalesur Rahman

    2018-04-01

    Full Text Available Currently, multi-antigenic vaccine use is the method of choice for the strategic control of ticks. Therefore, determining the efficacy of combined antigens is a promising avenue of research in the development of anti-tick vaccines. The antigen responsible for blood intake and reproduction has proven suitable as a vaccine antigen. It has been shown to silence Haemaphysalis longicornis salivary cystatin (HlSC-1 and subolesin by RNA interference. Adult unfed female ticks were injected with double-stranded RNA of (A subolesin, (B cystatin, (C subolesin plus cystatin, and (D injection buffer, then fed alongside normal unfed males up to spontaneous drop-down. The percentage of knockdowns was determined by real-time polymerase chain reaction. Sixty-three percent and 53% knockdown rates were observed in subolesin and cystatin double-stranded RNA-injected ticks respectively, while 32 and 26% knockdown rates of subolesin and cystatin transcript were observed in subolesin plus cystatin double-stranded RNA-injected ticks. Subolesin and/or cystatin knockdown causes a significant (p < 0.05 reduction in tick engorgement, egg mass weight, and egg conversion ratio. Most importantly, combined silencing did not act synergistically, but caused a similarly significant (p < 0.05 reduction in tick engorgement, egg mass weight, and egg conversion ratio. Therefore, the elucidation of multiple antigens may be helpful in the future of vaccines.

  3. RNA interference silences Microplitis demolitor bracovirus genes and implicates glc1.8 in disruption of adhesion in infected host cells

    International Nuclear Information System (INIS)

    Beck, Markus; Strand, Michael R.

    2003-01-01

    The family Polydnaviridae consists of ds-DNA viruses that are symbiotically associated with certain parasitoid wasps. PDVs are transmitted vertically but also are injected by wasps into hosts where they cause several physiological alterations including immunosuppression. The PDV genes responsible for mediating immunosuppression and other host alterations remain poorly characterized in large measure because viral mutants cannot be produced to study gene function. Here we report the use of RNA interference (RNAi) to specifically silence the glc1.8 and egf1.0 genes from Microplitis demolitor bracovirus (MdBV) in High Five cells derived from the lepidopteran Trichoplusia ni. Dose-response studies indicated that MdBV infects High Five cells and blocks the ability of these cells to adhere to culture plates. This response was very similar to what occurs in two classes of hemocytes, granular cells, and plasmatocytes, after infection by MdBV. Screening of monoclonal antibody (mAb) markers that distinguish different classes of lepidopteran hemocytes indicated that High Five cells cross-react with three mAbs that recognize granular cells from T. ni. Double-stranded RNA (dsRNA) complementary to glc1.8 specifically silenced glc1.8 expression and rescued the adhesive phenotype of High Five cells. Reciprocally, dsRNA complementary to egf1.0 silenced egf1.0 expression but had no effect on adhesion. The simplicity and potency of RNAi could be extremely useful for analysis of other PDV genes

  4. RNA.

    Science.gov (United States)

    Darnell, James E., Jr.

    1985-01-01

    Ribonucleic acid (RNA) converts genetic information into protein and usually must be processed to serve its function. RNA types, chemical structure, protein synthesis, translation, manufacture, and processing are discussed. Concludes that the first genes might have been spliced RNA and that humans might be closer than bacteria to primitive…

  5. Long Non-Coding RNA MEG3 Inhibits Cell Proliferation and Induces Apoptosis in Prostate Cancer

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    Gang Luo

    2015-11-01

    Full Text Available Background/Aims: Long non-coding RNAs (lncRNAs play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA maternally expressed gene 3 (MEG3 has been identified in several cancers, little is known about its role in prostate cancer progression. The aim of this study was to detect MEG3 expression in clinical prostate cancer tissues, investigate its biological functions in the development of prostate cancer and the underlying mechanism. Methods: MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 21 prostate cancer patients. The effects of MEG3 on PC3 and DU145 cells were assessed by MTT assay, colony formation assay, western blot and flow cytometry. Transfected PC3 cells were transplanted into nude mice, and the tumor growth curves were determined. Results: MEG3 decreased significantly in prostate cancer tissues relative to adjacent normal tissues. MEG3 inhibited intrinsic cell survival pathway in vitro and in vivo by reducing the protein expression of Bcl-2, enhancing Bax and activating caspase 3. We further demonstrated that MEG3 inhibited the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase. Conclusions: Our study presents an important role of MEG3 in the molecular etiology of prostate cancer and implicates the potential application of MEG3 in prostate cancer therapy.

  6. Salinity inhibits post transcriptional processing of chloroplast 16S rRNA in shoot cultures of jojoba (Simmondsia chinesis).

    Science.gov (United States)

    Mizrahi-Aviv, Ela; Mills, David; Benzioni, Aliza; Bar-Zvi, Dudy

    2005-03-01

    Chloroplast metabolism is rapidly affected by salt stress. Photosynthesis is one of the first processes known to be affected by salinity. Here, we report that salinity inhibits chloroplast post-transcriptional RNA processing. A differentially expressed 680-bp cDNA, containing the 3' sequence of 16S rRNA, transcribed intergenic spacer, exon 1 and intron of tRNA(Ile), was isolated by differential display reverse transcriptase PCR from salt-grown jojoba (Simmondsia chinesis) shoot cultures. Northern blot analysis indicated that although most rRNA appears to be fully processed, partially processed chloroplast 16S rRNA accumulates in salt-grown cultures. Thus, salinity appears to decrease the processing of the rrn transcript. The possible effect of this decreased processing on physiological processes is, as yet, unknown.

  7. MicroRNA-125a Inhibits Autophagy Activation and Antimicrobial Responses during Mycobacterial Infection.

    Science.gov (United States)

    Kim, Jin Kyung; Yuk, Jae-Min; Kim, Soo Yeon; Kim, Tae Sung; Jin, Hyo Sun; Yang, Chul-Su; Jo, Eun-Kyeong

    2015-06-01

    MicroRNAs (miRNAs) are small noncoding nucleotides that play critical roles in the regulation of diverse biological functions, including the response of host immune cells. Autophagy plays a key role in activating the antimicrobial host defense against Mycobacterium tuberculosis. Although the pathways associated with autophagy must be tightly regulated at a posttranscriptional level, the contribution of miRNAs and whether they specifically influence the activation of macrophage autophagy during M. tuberculosis infection are largely unknown. In this study, we demonstrate that M. tuberculosis infection of macrophages leads to increased expression of miRNA-125a-3p (miR-125a), which targets UV radiation resistance-associated gene (UVRAG), to inhibit autophagy activation and antimicrobial responses to M. tuberculosis. Forced expression of miR-125a significantly blocked M. tuberculosis-induced activation of autophagy and phagosomal maturation in macrophages, and inhibitors of miR-125a counteracted these effects. Both TLR2 and MyD88 were required for biogenesis of miR-125a during M. tuberculosis infection. Notably, activation of the AMP-activated protein kinase significantly inhibited the expression of miR-125a in M. tuberculosis-infected macrophages. Moreover, either overexpression of miR-125a or silencing of UVRAG significantly attenuated the antimicrobial effects of macrophages against M. tuberculosis. Taken together, these data indicate that miR-125a regulates the innate host defense by inhibiting the activation of autophagy and antimicrobial effects against M. tuberculosis through targeting UVRAG. Copyright © 2015 by The American Association of Immunologists, Inc.

  8. microRNA-150 inhibits the formation of macrophage foam cells through targeting adiponectin receptor 2

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing [Department of Geratory, Linzi District People’s Hospital of Zibo City, Zibo, Shandong (China); Zhang, Suhua, E-mail: drsuhuangzhang@qq.com [Department of HealthCare, Qilu Hospital of Shandong University (Qingdao), Qingdao City, Qingdao (China)

    2016-08-05

    Transformation of macrophages into foam cells plays a critical role in the pathogenesis of atherosclerosis. The aim of this study was to determine the expression and biological roles of microRNA (miR)-150 in the formation of macrophage foam cells and to identify its functional target(s). Exposure to 50 μg/ml oxidized low-density lipoprotein (oxLDL) led to a significant upregulation of miR-150 in THP-1 macrophages. Overexpression of miR-150 inhibited oxLDL-induced lipid accumulation in THP-1 macrophages, while knockdown of miR-150 enhanced lipid accumulation. apoA-I- and HDL-mediated cholesterol efflux was increased by 66% and 43%, respectively, in miR-150-overexpressing macrophages relative to control cells. In contrast, downregulation of miR-150 significantly reduced cholesterol efflux from oxLDL-laden macrophages. Bioinformatic analysis and luciferase reporter assay revealed adiponectin receptor 2 (AdipoR2) as a direct target of miR-150. Small interfering RNA-mediated downregulation of AdipoR2 phenocopied the effects of miR-150 overexpression, reducing lipid accumulation and facilitating cholesterol efflux in oxLDL-treated THP-1 macrophages. Knockdown of AdipoR2 induced the expression of proliferator-activated receptor gamma (PPARγ), liver X receptor alpha (LXRα), ABCA1, and ABCG1. Moreover, pharmacological inhibition of PPARγ or LXRα impaired AdipoR2 silencing-induced upregulation of ABCA1 and ABCG1. Taken together, our results indicate that miR-150 can attenuate oxLDL-induced lipid accumulation in macrophages via promotion of cholesterol efflux. The suppressive effects of miR-150 on macrophage foam cell formation are mediated through targeting of AdipoR2. Delivery of miR-150 may represent a potential approach to prevent macrophage foam cell formation in atherosclerosis. -- Highlights: •miR-150 inhibits macrophage foam cell formation. •miR-150 accelerates cholesterol efflux from oxLDL-laden macrophages. •miR-150 suppresses macrophage foam cell

  9. Expression of a single siRNA against a conserved region of NP gene strongly inhibits in vitro replication of different Influenza A virus strains of avian and swine origin.

    Science.gov (United States)

    Stoppani, Elena; Bassi, Ivan; Dotti, Silvia; Lizier, Michela; Ferrari, Maura; Lucchini, Franco

    2015-08-01

    Influenza A virus is the principal agent responsible of the respiratory tract's infections in humans. Every year, highly pathogenic and infectious strains with new antigenic assets appear, making ineffective vaccines so far developed. The discovery of RNA interference (RNAi) opened the way to the progress of new promising drugs against Influenza A virus and also to the introduction of disease resistance traits in genetically modified animals. In this paper, we show that Madin-Darby Canine Kidney (MDCK) cell line expressing short hairpin RNAs (shRNAs) cassette, designed on a specific conserved region of the nucleoprotein (NP) viral genome, can strongly inhibit the viral replication of four viral strains sharing the target sequence, reducing the viral mRNA respectively to 2.5×10(-4), 7.5×10(-5), 1.7×10(-3), 1.9×10(-4) compared to the control, as assessed by real-time PCR. Moreover, we demonstrate that during the challenge with a viral strain bearing a single mismatch on the target sequence, although a weaker inhibition is observed, viral mRNA is still lowered down to 1.2×10(-3) folds in the shRNA-expressing clone compared to the control, indicating a broad potential use of this approach. In addition, we developed a highly predictive and fast screening test of siRNA sequences based on dual-luciferase assay, useful for the in vitro prediction of the potential effect of viral inhibition. In conclusion, these findings reveal new siRNA sequences able to inhibit Influenza A virus replication and provide a basis for the development of siRNAs as prophylaxis and therapy for influenza infection both in humans and animals. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. New preclinical antimalarial drugs potently inhibit hepatitis C virus genotype 1b RNA replication.

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    Youki Ueda

    Full Text Available BACKGROUND: Persistent hepatitis C virus (HCV infection causes chronic liver diseases and is a global health problem. Although new triple therapy (pegylated-interferon, ribavirin, and telaprevir/boceprevir has recently been started and is expected to achieve a sustained virologic response of more than 70% in HCV genotype 1 patients, there are several problems to be resolved, including skin rash/ageusia and advanced anemia. Thus a new type of anti-HCV drug is still needed. METHODOLOGY/PRINCIPAL FINDINGS: Recently developed HCV drug assay systems using HCV-RNA-replicating cells (e.g., HuH-7-derived OR6 and Li23-derived ORL8 were used to evaluate the anti-HCV activity of drug candidates. During the course of the evaluation of anti-HCV candidates, we unexpectedly found that two preclinical antimalarial drugs (N-89 and its derivative N-251 showed potent anti-HCV activities at tens of nanomolar concentrations irrespective of the cell lines and HCV strains of genotype 1b. We confirmed that replication of authentic HCV-RNA was inhibited by these drugs. Interestingly, however, this anti-HCV activity did not work for JFH-1 strain of genotype 2a. We demonstrated that HCV-RNA-replicating cells were cured by treatment with only N-89. A comparative time course assay using N-89 and interferon-α demonstrated that N-89-treated ORL8 cells had more rapid anti-HCV kinetics than did interferon-α-treated cells. This anti-HCV activity was largely canceled by vitamin E. In combination with interferon-α and/or ribavirin, N-89 or N-251 exhibited a synergistic inhibitory effect. CONCLUSIONS/SIGNIFICANCE: We found that the preclinical antimalarial drugs N-89 and N-251 exhibited very fast and potent anti-HCV activities using cell-based HCV-RNA-replication assay systems. N-89 and N-251 may be useful as a new type of anti-HCV reagents when used singly or in combination with interferon and/or ribavirin.

  11. Molecular Basis for the Selective Inhibition of Respiratory Syncytial Virus RNA Polymerase by 2'-Fluoro-4'-Chloromethyl-Cytidine Triphosphate.

    Directory of Open Access Journals (Sweden)

    Jerome Deval

    2015-06-01

    Full Text Available Respiratory syncytial virus (RSV causes severe lower respiratory tract infections, yet no vaccines or effective therapeutics are available. ALS-8176 is a first-in-class nucleoside analog prodrug effective in RSV-infected adult volunteers, and currently under evaluation in hospitalized infants. Here, we report the mechanism of inhibition and selectivity of ALS-8176 and its parent ALS-8112. ALS-8176 inhibited RSV replication in non-human primates, while ALS-8112 inhibited all strains of RSV in vitro and was specific for paramyxoviruses and rhabdoviruses. The antiviral effect of ALS-8112 was mediated by the intracellular formation of its 5'-triphosphate metabolite (ALS-8112-TP inhibiting the viral RNA polymerase. ALS-8112 selected for resistance-associated mutations within the region of the L gene of RSV encoding the RNA polymerase. In biochemical assays, ALS-8112-TP was efficiently recognized by the recombinant RSV polymerase complex, causing chain termination of RNA synthesis. ALS-8112-TP did not inhibit polymerases from host or viruses unrelated to RSV such as hepatitis C virus (HCV, whereas structurally related molecules displayed dual RSV/HCV inhibition. The combination of molecular modeling and enzymatic analysis showed that both the 2'F and the 4'ClCH2 groups contributed to the selectivity of ALS-8112-TP. The lack of antiviral effect of ALS-8112-TP against HCV polymerase was caused by Asn291 that is well-conserved within positive-strand RNA viruses. This represents the first comparative study employing recombinant RSV and HCV polymerases to define the selectivity of clinically relevant nucleotide analogs. Understanding nucleotide selectivity towards distant viral RNA polymerases could not only be used to repurpose existing drugs against new viral infections, but also to design novel molecules.

  12. Phosphorylation of eIF2α is required for mRNA translation inhibition and survival during moderate hypoxia

    International Nuclear Information System (INIS)

    Koritzinsky, Marianne; Rouschop, Kasper M.A.; Beucken, Twan van den; Magagnin, Michael G.; Savelkouls, Kim; Lambin, Philippe; Wouters, Bradly G.

    2007-01-01

    Abstracts: Background and purpose: Human tumors are characterized by temporal fluctuations in oxygen tension. The biological pathways that respond to the dynamic tumor microenvironment represent potential molecular targets for cancer therapy. Anoxic conditions result in eIF2α dependent inhibition of overall mRNA translation, differential gene expression, hypoxia tolerance and tumor growth. The signaling pathway which governs eIF2α phosphorylation has therefore emerged as a potential molecular target. In this study, we investigated the role of eIF2α in regulating mRNA translation and hypoxia tolerance during moderate hypoxia. Since other molecular pathways that regulate protein synthesis are frequently mutated in cancer, we also assessed mRNA translation in a panel of cell lines from different origins. Materials and methods: Immortalized human fibroblast, transformed mouse embryo fibroblasts (MEFs) and cells from six cancer cell lines were exposed to 0.2% or 0.0% oxygen. We assayed global mRNA translation efficiency by polysome analysis, as well as proliferation and clonogenic survival. The role of eIF2α was assessed in MEFs harboring a homozygous inactivating mutation (S51A) as well as in U373-MG cells overexpressing GADD34 (C-term) under a tetracycline-dependent promoter. The involvement of eIF4E regulation was investigated in HeLa cells stably expressing a short hairpin RNA (shRNA) targeting 4E-BP1. Results: All cells investigated inhibited mRNA translation severely in response to anoxia and modestly in response to hypoxia. Two independent genetic cell models demonstrated that inhibition of mRNA translation in response to moderate hypoxia was dependent on eIF2α phosphorylation. Disruption of eIF2α phosphorylation caused sensitivity to hypoxia and anoxia. Conclusions: Disruption of eIF2α phosphorylation is a potential target for hypoxia-directed molecular cancer therapy

  13. [Lentivirus-mediated shRNA silencing of LAMP2A inhibits the proliferation of multiple myeloma cells].

    Science.gov (United States)

    Li, Lixuan; Li, Jia

    2015-05-01

    To study the effects of lentivirus-mediated short hairpin RNA (shRNA) silencing of lysosome-associated membrane protein type 2A (LAMP2A) expression on the proliferation of multiple myeloma cells. The constructed shRNA lentiviral vector was applied to infect human multiple myeloma cell line MM.1S, and stable expression cell line was obtained by puromycin screening. Western blotting was used to verify the inhibitory effect on LAMP2A protein expression. MTT assay was conducted to detect the effect of knocked-down LAMP2A on MM.1S cell proliferation, and the anti-tumor potency of suberoylanilide hydroxamic acid (SAHA) against the obtained MM.1S LAMP2A(shRNA) stable cell line. Lactate assay was performed to observe the impact of low LAMP2A expression on cell glycolysis. The stable cell line with low LAMP2A expression were obtained with the constructed human LAMP2A-shRNA lentiviral vector. Down-regulation of LAMP2A expression significantly inhibited MM.1S cell proliferation and enhanced the anti-tumor activity of SAHA. Interestingly, decreased LAMP2A expression also inhibited MM.1S cell lactic acid secretion. Down-regulation of LAMP2A expression could inhibit cell proliferation in multiple myeloma cells.

  14. siRNA associated with immunonanoparticles directed against cd99 antigen improves gene expression inhibition in vivo in Ewing's sarcoma.

    Science.gov (United States)

    Ramon, A L; Bertrand, J R; de Martimprey, H; Bernard, G; Ponchel, G; Malvy, C; Vauthier, C

    2013-07-01

    Ewing's sarcoma is a rare, mostly pediatric bone cancer that presents a chromosome abnormality called EWS/Fli-1, responsible for the development of the tumor. In vivo, tumor growth can be inhibited specifically by delivering small interfering RNA (siRNA) associated with nanoparticles. The aim of the work was to design targeted nanoparticles against the cell membrane glycoprotein cd99, which is overexpressed in Ewing's sarcoma cells to improve siRNA delivery to tumor cells. Biotinylated poly(isobutylcyanoacrylate) nanoparticles were conceived as a platform to design targeted nanoparticles with biotinylated ligands and using the biotin-streptavidin coupling method. The targeted nanoparticles were validated in vivo for the targeted delivery of siRNA after systemic administration to mice bearing a tumor model of the Ewing's sarcoma. The expression of the gene responsible of Ewing's sarcoma was inhibited at 78% ± 6% by associating the siRNA with the cd99-targeted nanoparticles compared with an inhibition of only 41% ± 9% achieved with the nontargeted nanoparticles. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Resveratrol Reduces Prostate Cancer Growth and Metastasis by Inhibiting the Akt/MicroRNA-21 Pathway

    Science.gov (United States)

    Sheth, Sandeep; Jajoo, Sarvesh; Kaur, Tejbeer; Mukherjea, Debashree; Sheehan, Kelly; Rybak, Leonard P.; Ramkumar, Vickram

    2012-01-01

    The consumption of foods containing resveratrol produces significant health benefits. Resveratrol inhibits cancer by reducing cell proliferation and metastasis and by inducing apoptosis. These actions could be explained by its ability to inhibit (ERK-1/2), Akt and suppressing the levels of estrogen and insulin growth factor -1 (IGF-1) receptor. How these processes are manifested into the antitumor actions of resveratrol is not clear. Using microarray studies, we show that resveratrol reduced the expression of various prostate-tumor associated microRNAs (miRs) including miR-21 in androgen-receptor negative and highly aggressive human prostate cancer cells, PC-3M-MM2. This effect of resveratrol was associated with reduced cell viability, migration and invasiveness. Additionally, resveratrol increased the expression of tumor suppressors, PDCD4 and maspin, which are negatively regulated by miR-21. Short interfering (si) RNA against PDCD4 attenuated resveratrol’s effect on prostate cancer cells, and similar effects were observed following over expression of miR-21 with pre-miR-21 oligonucleotides. PC-3M-MM2 cells also exhibited high levels of phospho-Akt (pAkt), which were reduced by both resveratrol and LY294002 (a PI3-kinase inhibitor). MiR-21 expression in these cells appeared to be dependent on Akt, as LY294002 reduced the levels of miR-21 along with a concurrent increase in PDCD4 expression. These in vitro findings were further corroborated in a severe combined immunodeficient (SCID) mouse xenograft model of prostate cancer. Oral administration of resveratrol not only inhibited the tumor growth but also decreased the incidence and number of metastatic lung lesions. These tumor- and metastatic-suppressive effects of resveratrol were associated with reduced miR-21 and pAkt, and elevated PDCD4 levels. Similar anti-tumor effects of resveratrol were observed in DU145 and LNCaP prostate cancer cells which were associated with suppression of Akt and PDCD4, but

  16. Influence of Bxpel1 Gene Silencing by dsRNA Interference on the Development and Pathogenicity of the Pine Wood Nematode, Bursaphelenchus xylophilus

    Science.gov (United States)

    Qiu, Xiu-Wen; Wu, Xiao-Qin; Huang, Lin; Ye, Jian-Ren

    2016-01-01

    As the causal agent of pine wilt disease (PWD), the pine wood nematode (PWN), Bursaphelenchus xylophilus, causes huge economic losses by devastating pine forests worldwide. The pectate lyase gene is essential for successful invasion of their host plants by plant-parasitic nematodes. To demonstrate the role of pectate lyase gene in the PWD process, RNA interference (RNAi) is used to analyze the function of the pectate lyase 1 gene in B. xylophilus (Bxpel1). The efficiency of RNAi was detected by real-time PCR. The result demonstrated that the quantity of B. xylophilus propagated with control solution treatment was 62 times greater than that soaking in double-stranded RNA (dsRNA) after B. xylophilus inoculation in Botrytis cinerea for the first generation (F1). The number of B. xylophilus soaking in control solution was doubled compared to that soaking in Bxpel1 dsRNA four days after inoculation in Pinus thunbergii. The quantity of B. xylophilus was reduced significantly (p < 0.001) after treatment with dsRNAi compared with that using a control solution treatment. Bxpel1 dsRNAi reduced the migration speed and reproduction of B. xylophilus in pine trees. The pathogenicity to P. thunbergii seedling of B. xylophilus was weaker after soaking in dsRNA solution compared with that after soaking in the control solution. Our results suggest that Bxpel1 gene is a significant pathogenic factor in the PWD process and this basic information may facilitate a better understanding of the molecular mechanism of PWD. PMID:26797602

  17. Knockdown of long non-coding RNA MAP3K20 antisense RNA 1 inhibits gastric cancer growth through epigenetically regulating miR-375.

    Science.gov (United States)

    Quan, Yongsheng; Zhang, Yan; Lin, Wei; Shen, Zhaohua; Wu, Shuai; Zhu, Changxin; Wang, Xiaoyan

    2018-03-04

    Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) play a critical role in tumorigenesis of gastric cancer. LncRNA MAP3K20 antisense RNA 1 (MLK7-AS1) has been identified as one of gastric cancer-specific lncRNAs. However, its precise role in gastric cancer remains unknown. In this study, we found that lncRNA MLK7-AS1 was significantly increased in gastric cancer tissues compared with in adjacent tissues. Gastric cancer patients with high MLK7-AS1 expression had a shorter survival and poorer prognosis. By loss-function assay, we demonstrated that knockdown of MLK7-AS1 inhibited cell proliferation and induced apoptosis in HGC27and MKN-45 cells. Furthermore, we identified miR-375 as a target of MLK7-AS1. MLK7-AS1 interacted with Dnmt1 and recruited it to miR-375 promotor, hyper-methylating miR-375 promotor and repressing miR-375 expression. Taken together, our findings demonstrate that knockdown of MLK7-AS1 by siRNA inhibits gastric cancer growth by epigenetically regulating miR-375. Thus, MLK7-AS1 may be a useful prognostic marker and therapeutic target for gastric cancer patients. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Chromophore-assisted light inactivation of pKi-67 leads to inhibition of ribosomal RNA synthesis.

    Science.gov (United States)

    Rahmanzadeh, R; Hüttmann, G; Gerdes, J; Scholzen, T

    2007-06-01

    Expression of the nuclear Ki-67 protein (pKi-67) is strongly associated with cell proliferation. For this reason, antibodies against this protein are widely used as prognostic tools for the assessment of cell proliferation in biopsies from cancer patients. Despite this broad application in histopathology, functional evidence for the physiological role of pKi-67 is still missing. Recently, we proposed a function of pKi-67 in the early steps of ribosomal RNA (rRNA) synthesis. Here, we have examined the involvement of pKi-67 in this process by photochemical inhibition using chromophore-assisted light inactivation (CALI). Anti-pKi-67 antibodies were labelled with the fluorochrome fluorescein 5(6)-isothiocyanate and were irradiated after binding to their target protein. Performing CALI in vitro on cell lysates led to specific cross-linking of pKi-67. Moreover, the upstream binding factor (UBF) necessary for rRNA transcription was also partly subjected to cross-link formation, indicating a close spatial proximity of UBF and pKi-67. CALI in living cells, using micro-injected antibody, caused a striking relocalization of UBF from foci within the nucleoli to spots located at the nucleolar rim or within the nucleoplasm. pKi-67-CALI resulted in dramatic inhibition of RNA polymerase I-dependent nucleolar rRNA synthesis, whereas RNA polymerase II-dependent nucleoplasmic RNA synthesis remained almost unaltered. Our data presented here argue for a crucial role of pKi-67 in RNA polymerase I-dependent nucleolar rRNA synthesis.

  19. Inhibition of Xenograft tumor growth by gold nanoparticle-DNA oligonucleotide conjugates-assisted delivery of BAX mRNA.

    Directory of Open Access Journals (Sweden)

    Ji-Hyun Yeom

    Full Text Available Use of non-biological agents for mRNA delivery into living systems in order to induce heterologous expression of functional proteins may provide more advantages than the use of DNA and/or biological vectors for delivery. However, the low efficiency of mRNA delivery into live animals, using non-biological systems, has hampered the use of mRNA as a therapeutic molecule. Here, we show that gold nanoparticle-DNA oligonucleotide (AuNP-DNA conjugates can serve as universal vehicles for more efficient delivery of mRNA into human cells, as well as into xenograft tumors generated in mice. Injections of BAX mRNA loaded on AuNP-DNA conjugates into xenograft tumors resulted in highly efficient mRNA delivery. The delivered mRNA directed the efficient production of biologically functional BAX protein, a pro-apoptotic factor, consequently inhibiting tumor growth. These results demonstrate that mRNA delivery by AuNP-DNA conjugates can serve as a new platform for the development of safe and efficient gene therapy.

  20. RNA interference: a new strategy in the evolutionary arms race between human control strategies and insect pests.

    Science.gov (United States)

    Machado, Vilmar; Rodríguez-García, María Juliana; Sánchez-García, Francisco Javier; Galan, Jose

    2014-01-01

    The relationship between humans and the insect pests of cultivated plants may be considered to be an indirect coevolutionary process, i.e., an arms race. Over time, humans have developed several strategies to minimize the negative impacts of insects on agricultural production. However, insects have made adaptive responses via the evolution of resistance to insecticides, and more recently against Bacillus thuriengiensis. Thus, we need to continuously invest resources in the development of new strategies for crop protection. Recent advances in genomics have demonstrated the possibility of a new weapon or strategy in this war, i.e., gene silencing, which involves blocking the expression of specific genes via mRNA inactivation. In the last decade, several studies have demonstrated the effectiveness of this strategy in the control of different species of insects. However, several technical difficulties need to be overcome to transform this potential into reality, such as the selection of target genes, the concentration of dsRNA, the nucleotide sequence of the dsRNA, the length of dsRNA, persistence in the insect body, and the life stage of the target species where gene silencing is most efficient. This study analyzes several aspects related to the use of gene silencing in pest control and it includes an overview of the inactivation process, as well as the problems that need to be resolved to transform gene silencing into an effective pest control method.

  1. Small interfering RNA targeting ILK inhibits metastasis in human tongue cancer cells through repression of epithelial-to-mesenchymal transition

    International Nuclear Information System (INIS)

    Xing, Yu; Qi, Jin; Deng, Shixiong; Wang, Cheng; Zhang, Luyu; Chen, Junxia

    2013-01-01

    Integrin-linked kinase (ILK) is a multifunctional serine/threonine kinase. Accumulating evidences suggest that ILK are involved in cell–matrix interactions, cell proliferation, invasion, migration, angiogenesis and Epithelial–mesenchymal transition (EMT). However, the underlying mechanisms remain largely unknown. EMT has been postulated as a prerequisite for metastasis. The reports have demonstrated that EMT was implicated in metastasis of oral squamous cell carcinomas. Therefore, here we further postulate that ILK might participate in EMT of tongue cancer. We showed that ILK siRNA inhibited EMT with low N-cadherin, Vimentin, Snail, Slug and Twist as well as high E-cadherin expression in vivo and in vitro. We found that knockdown of ILK inhibited cell proliferation, migration and invasion as well as changed cell morphology. We also demonstrated that ILK siRNA inhibited phosphorylation of downstream signaling targets Akt and GSK3β as well as reduced expression of MMP2 and MMP9. Furthermore, we found that the tongue tumor with high metastasis capability showed higher ILK, Vimentin, Snail, Slug and Twist as well as lower E-cadherin expression in clinical specimens. Finally, ILK siRNA led to the suppression for tumorigenesis and metastasis in vivo. Our findings suggest that ILK could be a novel diagnostic and therapeutic target for tongue cancer. Highlights: • ILK siRNA influences cell morphology, cell cycle, migration and invasion. • ILK siRNA affects the expression of proteins associated with EMT. • ILK expression is related to EMT in clinical human tongue tumors. • ILK siRNA inhibits metastasis of the tongue cancer cells through suppressing EMT

  2. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral

    Directory of Open Access Journals (Sweden)

    Claire M. Smith

    2016-08-01

    Full Text Available Defective interfering (DI viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8 was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1; it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral.

  3. The assembly of F1FO-ATP synthase is disrupted upon interference of RNA editing in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Hashimi, Hassan; Benkovičová, V.; Čermáková, P.; Lai, De Hua; Horváth, A.; Lukeš, Julius

    2010-01-01

    Roč. 40, č. 1 (2010), s. 45-54 ISSN 0020-7519 R&D Projects: GA ČR GA204/06/1558; GA AV ČR IAA500960705 Institutional research plan: CEZ:AV0Z60220518 Keywords : RNA editing * ATP synthase * mitochondrion * Trypanosoma * respiratory complex * membrane potential Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.822, year: 2010

  4. MicroRNA-467g inhibits new bone regeneration by targeting Ihh/Runx-2 signaling.

    Science.gov (United States)

    Kureel, Jyoti; John, Aijaz A; Dixit, Manisha; Singh, Divya

    2017-04-01

    MicroRNAs are important post transcriptional regulators of gene expression and play critical role in osteoblast differentiation. In this study we report miR-467g, an uncharacterized novel miRNA, in regulation of osteoblast functions. Over-expression of miR-467g inhibited osteoblast differentiation. Target prediction analysis tools and experimental validation by luciferase 3' UTR reporter assay identified Runx-2 as a direct target of miR-467g. Over expression of miR-467g in osteoblasts down regulated Runx-2 and Ihh signaling components. Furthermore, silencing of miR-467g was done to see its role in Ihh and Runx-2 mediated bone healing and regeneration in a drill hole injury model in BALB/c mice. Silencing of miR-467g led to significant increase in new bone regeneration and Ihh and Runx-2 localization at injury site in a day dependent manner. In conclusion, miR-467g negatively regulates osteogenesis by targeting Ihh/Runx-2 signaling. We, thus, propose that therapeutic approaches targeting miR-467g could be useful in enhancing the new bone formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Suppression of SOX18 by siRNA inhibits cell growth and invasion of breast cancer cells.

    Science.gov (United States)

    Zhang, Jianxiang; Ma, Yanmei; Wang, Shoujun; Chen, Fu; Gu, Yuanting

    2016-06-01

    Breast cancer is the most common malignancy in women around the world, and its incidence and mortality rates are still rising. An increasing number of studies have reported that SOX18 plays an important role in various cancers. However, the role of SOX18 in breast cancer remains poorly understood. In this study, we aimed to investigate the biological role and potential molecular mechanism of SOX18 in breast cancer. We found that the mRNA and protein expression levels of SOX18 were prevalently and significantly overexpressed in human breast cancer cell lines. Next, we performed loss-of-function experiments by transfection of two breast cancer cell lines, BT-474 and MCF-7, with SOX18 small interfering RNAs (siRNA). Results showed that SOX18 siRNA transfection significantly suppressed mRNA and protein expression of SOX18 in breast cancer cells. Furthermore, knockdown of SOX18 significantly inhibited cell proliferation and invasion, but promoted apoptosis in breast cancer cells. Importantly, several oncogenic proteins, including the Ras homolog gene family member A (RhoA), platelet-derived growth factor B (PDGFB), Insulin-like growth factor 1 receptor (IGF-1R), and matrix metalloproteinase-7 (MMP-7), were markedly decreased by SOX18 siRNA. Taken together, the results of our study suggest that knockdown of SOX18 inhibits breast cancer cell growth and invasion, possibly by downregulating downstream oncogenic proteins, providing novel insights into the development of breast cancer therapy through targeting of SOX18.

  6. Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent Protein Kinase PKR

    OpenAIRE

    Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V.; Lokugamage, Nandadeva; Head, Jennifer A.; Ikegami, Tetsuro

    2012-01-01

    Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general tr...

  7. Cognitive inhibition of number/length interference in a Piaget-like task in young adults: evidence from ERPs and fMRI.

    Science.gov (United States)

    Leroux, Gaëlle; Joliot, Marc; Dubal, Stéphanie; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie; Houdé, Olivier

    2006-06-01

    We sought to determine whether the neural traces of a previous cognitive developmental stage could be evidenced in young adults. In order to do so, 12 young adults underwent two functional imaging acquisitions (EEG then fMRI). During each session, two experimental conditions were applied: a Piaget-like task with number/length interference (INT), and a reference task with number/length covariation (COV). To succeed at Piaget's numerical task, which children under the age of 7 years usually fail, the subjects had to inhibit a misleading strategy, namely, the visuospatial length-equals-number bias, a quantification heuristic that is often relevant and that continues to be used through adulthood. Behavioral data confirmed that although there was an automation in the young adult subjects as assessed by the very high number of accurate responses (>97%), the inhibition of the "length equals number strategy" had a cognitive cost, as the reaction times were significantly higher in INT than in COV (with a difference of 230 ms). The event-related potential results acquired during the first session showed electrophysiological markers of the cognitive inhibition of the number/length interference. Indeed, the frontal N2 was greater during INT than during COV, and a P3(late)/P6 was detected only during INT. During the fMRI session, a greater activation of unimodal areas (the right middle and superior occipital cortex) and in the ventral route (the left inferior temporal cortex) was observed in INT than in COV. These results seem to indicate that when fully automated in adults, inhibition processes might take place in unimodal areas. Copyright 2005 Wiley-Liss, Inc.

  8. Development of antibody-modified chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier as a strategy for inhibiting HIV replication in astrocytes.

    Science.gov (United States)

    Gu, Jijin; Al-Bayati, Karam; Ho, Emmanuel A

    2017-08-01

    RNA interference (RNAi)-mediated gene silencing offers a novel treatment and prevention strategy for human immunodeficiency virus (HIV) infection. HIV was found to infect and replicate in human brain cells and can cause neuroinfections and neurological deterioration. We designed dual-antibody-modified chitosan/small interfering RNA (siRNA) nanoparticles to deliver siRNA across the blood-brain barrier (BBB) targeting HIV-infected brain astrocytes as a strategy for inhibiting HIV replication. We hypothesized that transferrin antibody and bradykinin B2 antibody could specifically bind to the transferrin receptor (TfR) and bradykinin B2 receptor (B2R), respectively, and deliver siRNA across the BBB into astrocytes as potential targeting ligands. In this study, chitosan nanoparticles (CS-NPs) were prepared by a complex coacervation method in the presence of siRNA, and antibody was chemically conjugated to the nanoparticles. The antibody-modified chitosan nanoparticles (Ab-CS-NPs) were spherical in shape, with an average particle size of 235.7 ± 10.2 nm and a zeta potential of 22.88 ± 1.78 mV. The therapeutic potential of the nanoparticles was evaluated based on their cellular uptake and gene silencing efficiency. Cellular accumulation and gene silencing efficiency of Ab-CS-NPs in astrocytes were significantly improved compared to non-modified CS-NPs and single-antibody-modified CS-NPs. These results suggest that the combination of anti-Tf antibody and anti-B2 antibody significantly increased the knockdown effect of siRNA-loaded nanoparticles. Thus, antibody-mediated dual-targeting nanoparticles are an efficient and promising delivery strategy for inhibiting HIV replication in astrocytes. Graphical abstract Graphic representation of dual-antibody-conjugated chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier (BBB) for inhibiting HIV replication in astrocytes. a Nanoparticle delivery to the BBB and penetration. b Tf

  9. MicroRNA-133b inhibits hepatocellular carcinoma cell progression by targeting Sirt1

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhijie [School of Biomedicine, Chengdu Medical College, Chengdu, Sichuan 610500 (China); Jiang, Hequn [The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610041 (China); Liu, Ying; Huang, Yong [School of Biomedicine, Chengdu Medical College, Chengdu, Sichuan 610500 (China); Xiong, Xin [Laboratory Research Center, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016 (China); Wu, Hongwei, E-mail: hongweiwu2118@sina.com [The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610041 (China); Dai, Xiaozhen, E-mail: xiaozhendai2012@163.com [School of Biomedicine, Chengdu Medical College, Chengdu, Sichuan 610500 (China); Chongqing University, Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing 400044 (China); Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY (United States)

    2016-05-01

    MicroRNAs (miRNAs) are a class of small non-coding RNAs that function as critical gene regulators by targeting mRNAs for translational repression or degradation. In this study, we showed that the expression level of miR-133b was decreased, while Sirt1 mRNA expression levels were increased in hepatocellular carcinoma (HCC) and cell lines, and we identified Sirt1 as a novel direct target of miR-133b. The over-expression of miR-133b suppressed Sirt1 expression. In addition, miR-133b over-expression resulted in attenuating HCC cell proliferation and invasion together with apoptosis increase in vitro. HepG2 cell transplantation revealed that up-regulation of miR-133b could inhibit HCC tumor genesis in vivo. Forced expression of Sirt1 partly rescued the effect of miR-133b in vitro. Furthermore, our study showed that miR-133b over-expression or Sirt1 down-regulation elevated E-cadherin expression, and repressed glypican-3 (GPC3) and the anti-apoptotic proteins (Bcl-2, Bcl-xL, and Mcl-1) expression. The inhibition of GPC3 expression repressed Bcl-2, Bcl-xL, and Mcl-1 expression, and elevated E-cadherin expression. Moreover, the Sirt1 up-regulation resulted in increases in HCC cell proliferation and invasion together with decreases apoptosis, and increases in the cytosolic accumulation and nuclear translocation of the transcription factor β-catenin in vitro. But the effect of Sirt1 up-regulation was partly reversed by GPC3 down-regulation in vitro. Taken together, these findings provide insight into the role and mechanism of miR-133b in regulating HCC cell proliferation, invasion and apoptosis via the miR-133b/Sirt1/GPC3/Wnt β-catenin axis, and miR-133b may serve as a potential therapeutic target in HCC in the future. - Highlights: • Sirt1 is a direct target of miR-133b in HCC. • miR-133b over-expression suppresses HCC progression in vitro and in vivo. • Sirt1 restoration reverses the effect of miR-133b over-expression on HCC cells. • GPC3 down-regulation reverses

  10. MicroRNA-133b inhibits hepatocellular carcinoma cell progression by targeting Sirt1

    International Nuclear Information System (INIS)

    Tian, Zhijie; Jiang, Hequn; Liu, Ying; Huang, Yong; Xiong, Xin; Wu, Hongwei; Dai, Xiaozhen

    2016-01-01

    MicroRNAs (miRNAs) are a class of small non-coding RNAs that function as critical gene regulators by targeting mRNAs for translational repression or degradation. In this study, we showed that the expression level of miR-133b was decreased, while Sirt1 mRNA expression levels were increased in hepatocellular carcinoma (HCC) and cell lines, and we identified Sirt1 as a novel direct target of miR-133b. The over-expression of miR-133b suppressed Sirt1 expression. In addition, miR-133b over-expression resulted in attenuating HCC cell proliferation and invasion together with apoptosis increase in vitro. HepG2 cell transplantation revealed that up-regulation of miR-133b could inhibit HCC tumor genesis in vivo. Forced expression of Sirt1 partly rescued the effect of miR-133b in vitro. Furthermore, our study showed that miR-133b over-expression or Sirt1 down-regulation elevated E-cadherin expression, and repressed glypican-3 (GPC3) and the anti-apoptotic proteins (Bcl-2, Bcl-xL, and Mcl-1) expression. The inhibition of GPC3 expression repressed Bcl-2, Bcl-xL, and Mcl-1 expression, and elevated E-cadherin expression. Moreover, the Sirt1 up-regulation resulted in increases in HCC cell proliferation and invasion together with decreases apoptosis, and increases in the cytosolic accumulation and nuclear translocation of the transcription factor β-catenin in vitro. But the effect of Sirt1 up-regulation was partly reversed by GPC3 down-regulation in vitro. Taken together, these findings provide insight into the role and mechanism of miR-133b in regulating HCC cell proliferation, invasion and apoptosis via the miR-133b/Sirt1/GPC3/Wnt β-catenin axis, and miR-133b may serve as a potential therapeutic target in HCC in the future. - Highlights: • Sirt1 is a direct target of miR-133b in HCC. • miR-133b over-expression suppresses HCC progression in vitro and in vivo. • Sirt1 restoration reverses the effect of miR-133b over-expression on HCC cells. • GPC3 down-regulation reverses

  11. The lethal giant larvae Gene in Tribolium castaneum: Molecular Properties and Roles in Larval and Pupal Development as Revealed by RNA Interference

    Directory of Open Access Journals (Sweden)

    Da Xiao

    2014-04-01

    Full Text Available We identified and characterized the TcLgl gene putatively encoding lethal giant larvae (Lgl protein from the red flour beetle (Tribolium castaneum. Analyses of developmental stage and tissue-specific expression patterns revealed that TcLgl was constitutively expressed. To examine the role of TcLgl in insect development, RNA interference was performed in early (1-day larvae, late (20-day larvae, and early (1-day pupae. The early larvae injected with double-stranded RNA of TcLgl (dsTcLgl at 100, 200, and 400 ng/larva failed to pupate, and 100% mortality was achieved within 20 days after the injection or before the pupation. The late larvae injected with dsTcLgl at these doses reduced the pupation rates to only 50.3%, 36.0%, and 18.2%, respectively. The un-pupated larvae gradually died after one week, and visually unaffected pupae failed to emerge into adults and died during the pupal stage. Similarly, when early pupae were injected with dsTcLgl at these doses, the normal eclosion rates were reduced to only 22.5%, 18.0%, and 11.2%, respectively, on day 7 after the injection, and all the adults with abnormal eclosion died in two days after the eclosion. These results indicate that TcLgl plays an essential role in insect development, especially during their metamorphosis.

  12. Mitochondrial uncoupling proteins regulate angiotensin-converting enzyme expression: crosstalk between cellular and endocrine metabolic regulators suggested by RNA interference and genetic studies.

    Science.gov (United States)

    Dhamrait, Sukhbir S; Maubaret, Cecilia; Pedersen-Bjergaard, Ulrik; Brull, David J; Gohlke, Peter; Payne, John R; World, Michael; Thorsteinsson, Birger; Humphries, Steve E; Montgomery, Hugh E

    2016-07-01

    Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin-converting enzyme (ACE) is the central component of endocrine and local tissue renin-angiotensin systems (RAS), which also regulate diverse aspects of whole-body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3-55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role. © 2016 The Authors. BioEssays published by WILEY Periodicals, Inc.

  13. Mitochondrial uncoupling proteins regulate angiotensin‐converting enzyme expression: crosstalk between cellular and endocrine metabolic regulators suggested by RNA interference and genetic studies

    Science.gov (United States)

    Maubaret, Cecilia; Pedersen‐Bjergaard, Ulrik; Brull, David J.; Gohlke, Peter; Payne, John R.; World, Michael; Thorsteinsson, Birger; Humphries, Steve E.; Montgomery, Hugh E.

    2015-01-01

    Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin‐converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems (RAS), which also regulate diverse aspects of whole‐body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3‐55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role. PMID:27347560

  14. Suboptimal inhibition of protease activity in human immunodeficiency virus type 1: Effects on virion morphogenesis and RNA maturation

    International Nuclear Information System (INIS)

    Moore, Michael D.; Fu, William; Soheilian, Ferri; Nagashima, Kunio; Ptak, Roger G.; Pathak, Vinay K.; Hu, Wei-Shau

    2008-01-01

    Protease activity within nascently released human immunodeficiency virus type 1 (HIV-1) particles is responsible for the cleavage of the viral polyproteins Gag and Gag-Pol into their constituent parts, which results in the subsequent condensation of the mature conical core surrounding the viral genomic RNA. Concomitant with viral maturation is a conformational change in the packaged viral RNA from a loosely associated dimer into a more thermodynamically stable form. In this study we used suboptimal concentrations of two protease inhibitors, lopinavir and atazanavir, to study their effects on Gag polyprotein processing and on the properties of the RNA in treated virions. Analysis of the treated virions demonstrated that even with high levels of inhibition of viral infectivity (IC 90 ), most of the Gag and Gag-Pol polyproteins were processed, although slight but significant increases in processing intermediates of Gag were detected. Drug treatments also caused a significant increase in the proportion of viruses displaying either immature or aberrant mature morphologies. The aberrant mature particles were characterized by an electron-dense region at the viral periphery and an electron-lucent core structure in the viral center, possibly indicating exclusion of the genomic RNA from these viral cores. Intriguingly, drug treatments caused only a slight decrease in overall thermodynamic stability of the viral RNA dimer, suggesting that the dimeric viral RNA was able to mature in the absence of correct core condensation

  15. Inhibition of Src by microRNA-23b increases the cisplatin sensitivity of chondrosarcoma cells.

    Science.gov (United States)

    Huang, Kai; Chen, Jun; Yang, Mo-Song; Tang, Yu-Jun; Pan, Feng

    2017-01-01

    Chondrosarcomas are malignant cartilage-forming tumors from low-grade to high-grade aggressive tumors characterized by metastasis. Cisplatin is an effective DNA-damaging anti-tumor agent for the treatment against a wide variety of solid tumors. However, chondrosarcomas are notorious for their resistance to conventional chemo- and radio- therapies. In this study, we report miR-23b acts as a tumor suppressor in chondrosarcoma. The expressions of miR-23b are down-regulated in chondrosarcoma patient samples and cell lines compared with adjacent normal tissues and human primary chondrocytes. In addition, overexpression of miR-23b suppresses chondrosarcoma cell proliferation. By comparison of the cisplatin resistant chondrosarcoma cells and parental cells, we observed miR-23b was significantly down regulated in cisplatin resistant cells. Moreover, we demonstrate here Src kinase is a direct target of miR-23b in chondrosarcoma cells. Overexpression of miR-23b suppresses Src-Akt pathway, leading to the sensitization of cisplatin resistant chondrosarcoma cells to cisplatin. This chemo-sensitivity effect by the miR-23b-mediated inhibition of Src-Akt pathway is verified with the restoration of Src kinase in miR-23b-overespressing chondrosarcoma cells, resulting in the acquirement of resistance to cisplatin. In summary, our study reveals a novel role of miR-23b in cisplatin resistance in chondrosarcoma and will contribute to the development of the microRNA-targeted anti-cancer therapeutics.

  16. RNA-based mutation analysis identifies an unusual MSH6 splicing defect and circumvents PMS2 pseudogene interference.

    Science.gov (United States)

    Etzler, J; Peyrl, A; Zatkova, A; Schildhaus, H-U; Ficek, A; Merkelbach-Bruse, S; Kratz, C P; Attarbaschi, A; Hainfellner, J A; Yao, S; Messiaen, L; Slavc, I; Wimmer, K

    2008-02-01

    Heterozygous germline mutations in one of the mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2 cause hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome, a dominantly inherited cancer susceptibility syndrome. Recent reports provide evidence for a novel recessively inherited cancer syndrome with constitutive MMR deficiency due to biallelic germline mutations in one of the MMR genes. MMR-deficiency (MMR-D) syndrome is characterized by childhood brain tumors, hematological and/or gastrointestinal malignancies, and signs of neurofibromatosis type 1 (NF1). We established an RNA-based mutation detection assay for the four MMR genes, since 1) a number of splicing defects may escape detection by the analysis of genomic DNA, and 2) DNA-based mutation detection in the PMS2 gene is severely hampered by the presence of multiple highly similar pseudogenes, including PMS2CL. Using this assay, which is based on direct cDNA sequencing of RT-PCR products, we investigated two families with children suspected to suffer from MMR-D syndrome. We identified a homozygous complex MSH6 splicing alteration in the index patients of the first family and a novel homozygous PMS2 mutation (c.182delA) in the index patient of the second family. Furthermore, we demonstrate, by the analysis of a PMS2/PMS2CL "hybrid" allele carrier, that RNA-based PMS2 testing effectively avoids the caveats of genomic DNA amplification approaches; i.e., pseudogene coamplification as well as allelic dropout, and will, thus, allow more sensitive mutation analysis in MMR deficiency and in HNPCC patients with PMS2 defects. (c) 2007 Wiley-Liss, Inc.

  17. A genome-scale RNA-interference screen identifies RRAS signaling as a pathologic feature of Huntington's disease.

    Directory of Open Access Journals (Sweden)

    John P Miller

    Full Text Available A genome-scale RNAi screen was performed in a mammalian cell-based assay to identify modifiers of mutant huntingtin toxicity. Ontology analysis of suppressor data identified processes previously implicated in Huntington's disease, including proteolysis, glutamate excitotoxicity, and mitochondrial dysfunction. In addition to established mechanisms, the screen identified multiple components of the RRAS signaling pathway as loss-of-function suppressors of mutant huntingtin toxicity in human and mouse cell models. Loss-of-function in orthologous RRAS pathway members also suppressed motor dysfunction in a Drosophila model of Huntington's disease. Abnormal activation of RRAS and a down-stream effector, RAF1, was observed in cellular models and a mouse model of Huntington's disease. We also observe co-localization of RRAS and mutant huntingtin in cells and in mouse striatum, suggesting that activation of R-Ras may occur through protein interaction. These data indicate that mutant huntingtin exerts a pathogenic effect on this pathway that can be corrected at multiple intervention points including RRAS, FNTA/B, PIN1, and PLK1. Consistent with these results, chemical inhibition of farnesyltransferase can also suppress mutant huntingtin toxicity. These data suggest that pharmacological inhibition of RRAS signaling may confer therapeutic benefit in Huntington's disease.

  18. Down-regulation of a chitin synthase a gene by RNA interference enhances pathogenicity of Beauveria bassiana ANU1 against Spodoptera exigua (HÜBNER).

    Science.gov (United States)

    Lee, Jung-Bok; Kim, Hyun Soo; Park, Youngjin

    2017-02-01

    Chitin synthase (CHS) is an important enzymatic component, which is required for chitin formation in the cuticles and cuticular linings of other tissues in insects. CHSs have been divided into two classes, classes A and B, based on their amino acid sequence similarities and functions. Class A CHS (CHS-A) is specifically expressed in the epidermis and related ectodermal cells such as tracheal cells, while class B CHS (CHS-B) is expressed in gut epithelial cells that produce peritrophic matrices. In this study, we cloned the CHS-A gene from the beet armyworm, Spodoptera exigua (SeCHS-A). The SeCHS-A contains an open reading frame of 4,698 nucleotides, encoding a protein of 1,565 amino acids with a predicted molecular mass of approximately 177.8 kDa. The SeCHS-A mRNA was expressed in all developmental stages and specifically in the epidermis and tracheae tissue by quantitative real-time-PCR analysis. Expression of SeCHS-A gene was suppressed by feeding double-stranded RNA (dsCHS-A, 400 ng/larva) in the third instar larvae of S. exigua. Suppression of the SeCHS-A gene expression significantly increased 35% of mortality on pupation of S. exigua. Also, the third instar larvae fed with dsCHS-A significantly increased susceptibility to entomopathogenic fungi, Beauveria bassiana ANU1 at 3 days after treatment. These results suggest that the SeCHS-A gene plays an important role in development of S. exigua and RNA interference may apply to effective pest control with B. bassiana. © 2017 Wiley Periodicals, Inc.

  19. Combined genome-wide expression profiling and targeted RNA interference in primary mouse macrophages reveals perturbation of transcriptional networks associated with interferon signalling

    Directory of Open Access Journals (Sweden)

    Craigon Marie

    2009-08-01

    Full Text Available Abstract Background Interferons (IFNs are potent antiviral cytokines capable of reprogramming the macrophage phenotype through the induction of interferon-stimulated genes (ISGs. Here we have used targeted RNA interference to suppress the expression of a number of key genes associated with IFN signalling in murine macrophages prior to stimulation with interferon-gamma. Genome-wide changes in transcript abundance caused by siRNA activity were measured using exon-level microarrays in the presence or absence of IFNγ. Results Transfection of murine bone-marrow derived macrophages (BMDMs with a non-targeting (control siRNA and 11 sequence-specific siRNAs was performed using a cationic lipid transfection reagent (Lipofectamine2000 prior to stimulation with IFNγ. Total RNA was harvested from cells and gene expression measured on Affymetrix GeneChip Mouse Exon 1.0 ST Arrays. Network-based analysis of these data revealed six siRNAs to cause a marked shift in the macrophage transcriptome in the presence or absence IFNγ. These six siRNAs targeted the Ifnb1, Irf3, Irf5, Stat1, Stat2 and Nfkb2 transcripts. The perturbation of the transcriptome by the six siRNAs was highly similar in each case and affected the expression of over 600 downstream transcripts. Regulated transcripts were clustered based on co-expression into five major groups corresponding to transcriptional networks associated with the type I and II IFN response, cell cycle regulation, and NF-KB signalling. In addition we have observed a significant non-specific immune stimulation of cells transfected with siRNA using Lipofectamine2000, suggesting use of this reagent in BMDMs, even at low concentrations, is enough to induce a type I IFN response. Conclusion Our results provide evidence that the type I IFN response in murine BMDMs is dependent on Ifnb1, Irf3, Irf5, Stat1, Stat2 and Nfkb2, and that siRNAs targeted to these genes results in perturbation of key transcriptional networks associated

  20. Attenuation of alpha2A-adrenergic receptor expression in neonatal rat brain by RNA interference or antisense oligonucleotide reduced anxiety in adulthood.

    Science.gov (United States)

    Shishkina, G T; Kalinina, T S; Dygalo, N N

    2004-01-01

    Brain alpha2-adrenergic receptors (alpha2-ARs) have been implicated in the regulation of anxiety, which is associated with stress. Environmental treatments during neonatal development could modulate the level of brain alpha2-AR expression and alter anxiety in adults, suggesting possible involvement of these receptors in early-life programming of anxiety state. The present study was undertaken to determine whether the reduction of the expression of A subtype of these receptors most abundant in the neonatal brain affects anxiety-related behavior in adulthood. We attenuated the expression of alpha2A-ARs during neonatal life by two different sequence specific approaches, antisense technology and RNA interference. Treatment of rats with the antisense oligodeoxynucleotide or short interfering RNA (siRNA) against alpha2A-ARs on the days 2-4 of their life, produced a marked acute decrease in the levels of both alpha2A-AR mRNA and [3H]RX821002 binding sites in the brainstem into which drugs were injected. The decrease of alpha2A-AR expression in the neonatal brainstem influenced the development of this receptor system in the brain regions as evidenced by the increased number of [3H]RX821002 binding sites in the hypothalamus of adult animals with both neonatal alpha2A-AR knockdown treatments; also in the frontal cortex of antisense-treated, and in the hippocampus of siRNA-treated adult rats. These adult animals also demonstrated a decreased anxiety in the elevated plus-maze as evidenced by an increased number of the open arm entries, greater proportion of time spent in the open arms, and more than a two-fold increase in the number of exploratory head dips. The results provide the first evidence that the reduction in the brain expression of a gene encoding for alpha2A-AR during neonatal life led to the long-term neurochemical and behavioral alterations. The data suggests that alterations in the expression of the receptor-specific gene during critical periods of brain

  1. Sox9-regulated miRNA-574-3p inhibits chondrogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    David Guérit

    Full Text Available The aim of this study was to identify new microRNAs (miRNAs that are modulated during the differentiation of mesenchymal stem cells (MSCs toward chondrocytes. Using large scale miRNA arrays, we compared the expression of miRNAs in MSCs (day 0 and at early time points (day 0.5 and 3 after chondrogenesis induction. Transfection of premiRNA or antagomiRNA was performed on MSCs before chondrogenesis induction and expression of miRNAs and chondrocyte markers was evaluated at different time points during differentiation by RT-qPCR. Among miRNAs that were modulated during chondrogenesis, we identified miR-574-3p as an early up-regulated miRNA. We found that miR-574-3p up-regulation is mediated via direct binding of Sox9 to its promoter region and demonstrated by reporter assay that retinoid X receptor (RXRα is one gene specifically targeted by the miRNA. In vitro transfection of MSCs with premiR-574-3p resulted in the inhibition of chondrogenesis demonstrating its role during the commitment of MSCs towards chondrocytes. In vivo, however, both up- and down-regulation of miR-574-3p expression inhibited differentiation toward cartilage and bone in a model of heterotopic ossification. In conclusion, we demonstrated that Sox9-dependent up-regulation of miR-574-3p results in RXRα down-regulation. Manipulating miR-574-3p levels both in vitro and in vivo inhibited chondrogenesis suggesting that miR-574-3p might be required for chondrocyte lineage maintenance but also that of MSC multipotency.

  2. Targeting membrane-bound viral RNA synthesis reveals potent inhibition of diverse coronaviruses including the middle East respiratory syndrome virus.

    Directory of Open Access Journals (Sweden)

    Anna Lundin

    2014-05-01

    Full Text Available Coronaviruses raise serious concerns as emerging zoonotic viruses without specific antiviral drugs available. Here we screened a collection of 16671 diverse compounds for anti-human coronavirus 229E activity and identified an inhibitor, designated K22, that specifically targets membrane-bound coronaviral RNA synthesis. K22 exerts most potent antiviral activity after virus entry during an early step of the viral life cycle. Specifically, the formation of double membrane vesicles (DMVs, a hallmark of coronavirus replication, was greatly impaired upon K22 treatment accompanied by near-complete inhibition of viral RNA synthesis. K22-resistant viruses contained substitutions in non-structural protein 6 (nsp6, a membrane-spanning integral component of the viral replication complex implicated in DMV formation, corroborating that K22 targets membrane bound viral RNA synthesis. Besides K22 resistance, the nsp6 mutants induced a reduced number of DMVs, displayed decreased specific infectivity, while RNA synthesis was not affected. Importantly, K22 inhibits a broad range of coronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV, and efficient inhibition was achieved in primary human epithelia cultures representing the entry port of human coronavirus infection. Collectively, this study proposes an evolutionary conserved step in the life cycle of positive-stranded RNA viruses, the recruitment of cellular membranes for viral replication, as vulnerable and, most importantly, druggable target for antiviral intervention. We expect this mode of action to serve as a paradigm for the development of potent antiviral drugs to combat many animal and human virus infections.

  3. Ibrutinib targets microRNA-21 in multiple myeloma cells by inhibiting NF-κB and STAT3.

    Science.gov (United States)

    Ma, Jing; Gong, Wei; Liu, Su; Li, Qian; Guo, Mengzheng; Wang, Jinhan; Wang, Suying; Chen, Naiyao; Wang, Yafei; Liu, Qiang; Zhao, Hui

    2018-01-01

    The oncogenic microRNA-21 contributes to the pathogenesis of multiple myeloma. Ibrutinib (also referred to as PCI-32765), an inhibitor of Bruton's tyrosine kinase, while its effects on multiple myeloma have not been well described. Here, we show that microRNA-21 is an oncogenic marker closely linked with progression of multiple myeloma. Moreover, ibrutinib attenuates microRNA-21 expression in multiple myeloma cells by inhibiting nuclear factor-κB and signal transducer and activator of transcription 3 signaling pathways. Taken together, our results suggest that ibrutinib is a promising potential treatment for multiple myeloma. Further investigation of mechanisms of ibrutinib function in multiple myeloma will be necessary to evaluate its use as a novel multiple myeloma treatment.

  4. HTLV-1 Tax plugs and freezes UPF1 helicase leading to nonsense-mediated mRNA decay inhibition.

    Science.gov (United States)

    Fiorini, Francesca; Robin, Jean-Philippe; Kanaan, Joanne; Borowiak, Malgorzata; Croquette, Vincent; Le Hir, Hervé; Jalinot, Pierre; Mocquet, Vincent

    2018-01-30

    Up-Frameshift Suppressor 1 Homolog (UPF1) is a key factor for nonsense-mediated mRNA decay (NMD), a cellular process that can actively degrade mRNAs. Here, we study NMD inhibition during infection by human T-cell lymphotropic virus type I (HTLV-1) and characterise the influence of the retroviral Tax factor on UPF1 activity. Tax interacts with the central helicase core domain of UPF1 and might plug the RNA channel of UPF1, reducing its affinity for nucleic acids. Furthermore, using a single-molecule approach, we show that the sequential interaction of Tax with a RNA-bound UPF1 freezes UPF1: this latter is less sensitive to the presence of ATP and shows translocation defects, highlighting the importance of this feature for NMD. These mechanistic insights reveal how HTLV-1 hijacks the central component of NMD to ensure expression of its own genome.

  5. The P0 protein encoded by cotton leafroll dwarf virus (CLRDV) inhibits local but not systemic RNA silencing.

    Science.gov (United States)

    Delfosse, Verónica C; Agrofoglio, Yamila C; Casse, María F; Kresic, Iván Bonacic; Hopp, H Esteban; Ziegler-Graff, Véronique; Distéfano, Ana J

    2014-02-13

    Plants employ RNA silencing as a natural defense mechanism against viruses. As a counter-defense, viruses encode silencing suppressor proteins (SSPs) that suppress RNA silencing. Most, but not all, the P0 proteins encoded by poleroviruses have been identified as SSP. In this study, we demonstrated that cotton leafroll dwarf virus (CLRDV, genus Polerovirus) P0 protein suppressed local silencing that was induced by sense or inverted repeat transgenes in Agrobacterium co-infiltration assay in Nicotiana benthamiana plants. A CLRDV full-length infectious cDNA clone that is able to infect N. benthamiana through Agrobacterium-mediated inoculation also inhibited local silencing in co-infiltration assays, suggesting that the P0 protein exhibits similar RNA silencing suppression activity when expressed from the full-length viral genome. On the other hand, the P0 protein did not efficiently inhibit the spread of systemic silencing signals. Moreover, Northern blotting indicated that the P0 protein inhibits the generation of secondary but not primary small interfering RNAs. The study of CLRDV P0 suppression activity may contribute to understanding the molecular mechanisms involved in the induction of cotton blue disease by CLRDV infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Ground-based inhibition: Suppressive perceptual mechanisms interact with top-down attention to reduce distractor interference.

    Science.gov (United States)

    Wager, Erica; Peterson, Mary A; Folstein, Jonathan R; Scalf, Paige E

    2015-01-01

    Successful attentional function requires inhibition of distracting information (e.g., Deutsch & Deutsch, 1963). Similarly, perceptual segregation of the visual world into figure and ground entails ground suppression (e.g., Likova & Tyler, 2008; Peterson & Skow, 2008). Here, we ask whether the suppressive processes of attention and perception-distractor inhibition and ground suppression-interact to more effectively insulate task performance from interfering information. We used a variant of the Eriksen flanker paradigm to assess the efficacy of distractor inhibition. Participants indicated the right/left orientation of a central arrow, which could be flanked by congruent, neutral, or incongruent stimuli. We manipulated the degree to which the ground region of a display was suppressed and measured the influence of this manipulation on the efficacy with which participants could inhibit responses from incongruent flankers. Greater ground suppression reduced the influence on target identification of interfering, incongruent information, but not that of facilitative, congruent information. These data are the first to show that distractor inhibition interacts with ground suppression to improve attentional function.

  7. FUNDAMENTAL STUDY OF DETECTION OF MUSCLE HYPERTROPHY-ORIENTED GENE DOPING BY MYOSTATIN KNOCK DOWN USING RNA INTERFERENCE

    Directory of Open Access Journals (Sweden)

    Tohru Takemasa

    2012-06-01

    Full Text Available To investigate the feasibility of developing a method for detection of gene doping in power-athletes, we devised an experimental model system. Myostatin is a potent negative regulator of skeletal muscle development and growth, and myostatin-knockout mice exhibit a double-muscle phenotype. To achieve knockdown, we constructed plasmids expressing short hairpin interfering RNAs (shRNAs against myostatin. These shRNAs were transfected into C2C12 cultured cells or injected into the tibialis anterior (TA muscle of adult mice. By performing in vitro and in vivo experiments, we found that some shRNAs effectively reduced the expression of myostatin, and that the TA muscle showed hypertrophy of up to 27.9%. Then, using real-time PCR, we tried to detect the shRNA plasmid in the serum or muscles of mice into which it had been injected. Although we were unable to detect the plasmid in serum samples, it was detectable in the treated muscle at least four weeks after induction. We were also able to detect the plasmid in muscle in the vicinity of the TA. This gene doping model system will be useful for further studies aimed at doping control

  8. Direct and indirect effects of RNA interference against pyridoxal kinase and pyridoxine 5'-phosphate oxidase genes in Bombyx mori.

    Science.gov (United States)

    Huang, ShuoHao; Yao, LiLi; Zhang, JianYun; Huang, LongQuan

    2016-08-01

    Vitamin B6 comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate is a coenzyme involved in a high diversity of biochemical reactions. Humans and animals obtain B6 vitamers from diet, and synthesize pyridoxal 5'-phosphate by pyridoxal kinase and pyridoxine 5'-phosphate oxidase. Currently, little is known on how pyridoxal 5'-phosphate biosynthesis is regulated, and pyridoxal 5'-phosphate is supplied to meet their requirement in terms of cofactor. Bombyx mori is a large silk-secreting insect, in which protein metabolism is most active, and the vitamin B6 demand is high. In this study, we successfully down-regulated the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase by body cavity injection of synthesized double-stranded small interfering RNA to 5th instar larvae of Bombyx mori, and analyzed the gene transcription levels of pyridoxal 5'-phosphate dependent enzymes, phosphoserine aminotransferase and glutamic-oxaloacetic transaminase. Results show that the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase has a greater impact on the gene transcription of enzymes using pyridoxal 5'-phosphate as a cofactor in Bombyx mori. Our study suggests that pyridoxal 5'-phosphate biosynthesis and dynamic balance may be regulated by genetic networks. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. RNA interference of GhPEPC2 enhanced seed oil accumulation and salt tolerance in Upland cotton.

    Science.gov (United States)

    Zhao, Yanpeng; Huang, Yi; Wang, Yumei; Cui, Yupeng; Liu, Zhengjie; Hua, Jinping

    2018-06-01

    Phosphoenolpyruvate carboxylase (PEPCase) mainly produces oxaloacetic acid for tricarboxylic acid (TCA) cycle. Here we reported that GhPEPC2 silencing with PEPC2-RNAi vector could regulate oil and protein accumulation in cottonseeds. In GhPEPC2 transgenic plants, PEPCase activities in immature embryos were significantly reduced, and the oil content in seed kernel was increased 7.3 percentages, whereas total proteins decreased 5.65 percentages. Compared to wild type, agronomical traits of transgenic plant were obviously unaffected. Furthermore, gene expression profile of GhPEPC2 transgenic seeds were investigated using RNA-seq, most lipid synthesis related genes were up-regulated, but amino acid metabolic related genes were down-regulated. In addition, the GhPEPC2 transgenic cotton seedlings were stressed using sodium salts at seedling stage, and the salt tolerance was significantly enhanced. Our observations of GhPEPC2 in cotton would shade light on understanding the regulation of oil content, protein accumulation and salt tolerance enhancement in other plants. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Targeted cleavage of hepatitis E virus 3' end RNA mediated by hammerhead ribozymes inhibits viral RNA replication

    International Nuclear Information System (INIS)

    Sriram, Bandi; Thakral, Deepshi; Panda, Subrat Kumar

    2003-01-01

    The 3' end of hepatitis E virus (HEV) contains cis-acting regulatory element, which plays an important role in viral replication. To develop specific replication inhibitor at the molecular level, mono- and di-hammerhead ribozymes (Rz) were designed and synthesized against the conserved 3' end sequences of HEV, which cleave at nucleotide positions 7125 and 7112/7125, respectively. Di-hammerhead ribozyme with two catalytic motifs in tandem was designed to cleave simultaneously at two sites spaced 13 nucleotides apart, which increases the overall cleavage efficiency and prevents the development of escape mutants. Specific cleavage products were obtained with both the ribozymes in vitro at physiological conditions. The inactive control ribozymes showed no cleavage. The ribozymes showed specific inhibition of HEV 3' end fused-luciferase reporter gene expression by ∼37 and ∼60%, respectively in HepG2 cells. These results demonstrate a feasible approach to inhibit the HEV replication to a limited extent by targeting the cis-acting 3' end of HEV with hammerhead ribozymes

  11. A human torque teno virus encodes a microRNA that inhibits interferon signaling.

    Directory of Open Access Journals (Sweden)

    Rodney P Kincaid

    Full Text Available Torque teno viruses (TTVs are a group of viruses with small, circular DNA genomes. Members of this family are thought to ubiquitously infect humans, although causal disease associations are currently lacking. At present, there is no understanding of how infection with this diverse group of viruses is so prevalent. Using a combined computational and synthetic approach, we predict and identify miRNA-coding regions in diverse human TTVs and provide evidence for TTV miRNA production in vivo. The TTV miRNAs are transcribed by RNA polymerase II, processed by Drosha and Dicer, and are active in RISC. A TTV mutant defective for miRNA production replicates as well as wild type virus genome; demonstrating that the TTV miRNA is dispensable for genome replication in a cell culture model. We demonstrate that a recombinant TTV genome is capable of expressing an exogenous miRNA, indicating the potential utility of TTV as a small RNA vector. Gene expression profiling of host cells identifies N-myc (and STAT interactor (NMI as a target of a TTV miRNA. NMI transcripts are directly regulated through a binding site in the 3'UTR. SiRNA knockdown of NMI contributes to a decreased response to interferon signaling. Consistent with this, we show that a TTV miRNA mediates a decreased response to IFN and increased cellular proliferation in the presence of IFN. Thus, we add Annelloviridae to the growing list of virus families that encode miRNAs, and suggest that miRNA-mediated immune evasion can contribute to the pervasiveness associated with some of these viruses.

  12. Suppression of the expression of hypoxia-inducible factor-1α by RNA interference alleviates hypoxia-induced pulmonary hypertension in adult rats.

    Science.gov (United States)

    Li, Ying; Shi, Bo; Huang, Liping; Wang, Xin; Yu, Xiaona; Guo, Baosheng; Ren, Weidong

    2016-12-01

    Hypoxia-inducible factor-1α (HIF-1α) has been implicated in the pathogenesis of hypoxic pulmonary hypertension (PH). However, the potential clinical value of HIF-1α as a therapeutic target in the treatment of PH has not yet been evaluated. In this study, an animal model of hypoxia-induced PH was established by exposing adult rats to 10% O2 for 3 weeks, and the effects of the lentivirus-mediated delivery of HIF-1α short hairpin RNA (shRNA) by intratracheal instillation prior to exposure to hypoxia on the manifestations of hypoxia-induced PH were assessed. The successful delivery of HIF-1α shRNA into the pulmonary arteries effectively suppressed the hypoxia-induced upregulation of HIF-1α, accompanied by the prominent attenuation the symptoms associated with hypoxia-induced PH, including the elevation of pulmonary arterial pressure, hypertrophy and hyperplasia of pulmonary artery smooth muscle cells (PASMCs), as well as the muscularization of pulmonary arterioles. In addition, the knockdown of HIF-1α in cultured rat primary PASMCs significantly inhibited the hypoxia-induced acceleration of the cell cycle and the proliferation of the PASMCs, suggesting that HIF-1α may be a direct mediator of PASMC hyperplasia in hypoxia-induced PH. In conclusion, this study demonstrates the potent suppressive effects of HIF-1α shRNA on hypoxia-induced PH and PASMC hyperplasia, providing evidence for the potential application of HIF-1α shRNA in the treatment of hypoxic PH.

  13. Fundamental study of detection of muscle hypertrophy-oriented gene doping by myostatin knock down using RNA interference.

    Science.gov (United States)

    Takemasa, Tohru; Yakushiji, Naohisa; Kikuchi, Dale Manjiro; Deocaris, Custer; Widodo; Machida, Masanao; Kiyosawa, Hidenori

    2012-01-01

    To investigate the feasibility of developing a method for detection of gene doping in power-athletes, we devised an experimental model system. Myostatin is a potent negative regulator of skeletal muscle development and growth, and myostatin-knockout mice exhibit a double-muscle phenotype. To achieve knockdown, we constructed plasmids expressing short hairpin interfering RNAs (shRNAs) against myostatin. These shRNAs were transfected into C2C12 cultured cells or injected into the tibialis anterior (TA) muscle of adult mice. By performing in vitro and in vivo experiments, we found that some shRNAs effectively reduced the expression of myostatin, and that the TA muscle showed hypertrophy of up to 27.9%. Then, using real-time PCR, we tried to detect the shRNA plasmid in the serum or muscles of mice into which it had been injected. Although we were unable to detect the plasmid in serum samples, it was detectable in the treated muscle at least four weeks after induction. We were also able to detect the plasmid in muscle in the vicinity of the TA. This gene doping model system will be useful for further studies aimed at doping control. Key pointsUsing a myostatin knockdown plasmid, we have succeeded in creating a model system for gene doping using mice that resulted in muscle hypertrophy greater than that reported previously.We confirmed that there was a limit of gene doping detection using real-time PCR, either from serum or muscle smple.This model experimental system can be utilized for examining indirect methods of gene doping detection such as immune responses to gene transfer or a profiling approach using DNA microarray.

  14. RNA interference of NADPH-cytochrome P450 reductase results in reduced insecticide resistance in the bed bug, Cimex lectularius.

    Science.gov (United States)

    Zhu, Fang; Sams, Sarah; Moural, Tim; Haynes, Kenneth F; Potter, Michael F; Palli, Subba R

    2012-01-01

    NADPH-cytochrome P450 reductase (CPR) plays a central role in cytochrome P450 action. The genes coding for P450s are not yet fully identified in the bed bug, Cimex lectularius. Hence, we decided to clone cDNA and knockdown the expression of the gene coding for CPR which is suggested to be required for the function of all P450s to determine whether or not P450s are involved in resistance of bed bugs to insecticides. The full length Cimex lectularius CPR (ClCPR) cDNA was isolated from a deltamethrin resistant bed bug population (CIN-1) using a combined PCR strategy. Bioinformatics and in silico modeling were employed to identify three conserved binding domains (FMN, FAD, NADP), a FAD binding motif, and the catalytic residues. The critical amino acids involved in FMN, FAD, NADP binding and their putative functions were also analyzed. No signal peptide but a membrane anchor domain with 21 amino acids which facilitates the localization of ClCPR on the endoplasmic reticulum was identified in ClCPR protein. Phylogenetic analysis showed that ClCPR is closer to the CPR from the body louse, Pediculus humanus corporis than to the CPRs from the other insect species studied. The ClCPR gene was ubiquitously expressed in all tissues tested but showed an increase in expression as immature stages develop into adults. We exploited the traumatic insemination mechanism of bed bugs to inject dsRNA and successfully knockdown the expression of the gene coding for ClCPR. Suppression of the ClCPR expression increased susceptibility to deltamethrin in resistant populations but not in the susceptible population of bed bugs. These data suggest that P450-mediated metabolic detoxification may serve as one of the resistance mechanisms in bed bugs.

  15. A PCR-Based Method to Construct Lentiviral Vector Expressing Double Tough Decoy for miRNA Inhibition.

    Directory of Open Access Journals (Sweden)

    Huiling Qiu

    Full Text Available DNA vector-encoded Tough Decoy (TuD miRNA inhibitor is attracting increased attention due to its high efficiency in miRNA suppression. The current methods used to construct TuD vectors are based on synthesizing long oligonucleotides (~90 mer, which have been costly and problematic because of mutations during synthesis. In this study, we report a PCR-based method for the generation of double Tough Decoy (dTuD vector in which only two sets of shorter oligonucleotides (< 60 mer were used. Different approaches were employed to test the inhibitory potency of dTuDs. We demonstrated that dTuD is the most efficient method in miRNA inhibition in vitro and in vivo. Using this method, a mini dTuD library against 88 human miRNAs was constructed and used for a high-throughput screening (HTS of AP-1 pathway-related miRNAs. Seven miRNAs (miR-18b-5p, -101-3p, -148b-3p, -130b-3p, -186-3p, -187-3p and -1324 were identified as candidates involved in AP-1 pathway regulation. This novel method allows for an accurate and cost-effective generation of dTuD miRNA inhibitor, providing a powerful tool for efficient miRNA suppression in vitro and in vivo.

  16. Three new shRNA expression vectors targeting the CYP3A4 coding sequence to inhibit its expression

    Directory of Open Access Journals (Sweden)

    Siyun Xu

    2014-10-01

    Full Text Available RNA interference (RNAi is useful for selective gene silencing. Cytochrome P450 3A4 (CYP3A4, which metabolizes approximately 50% of drugs in clinical use, plays an important role in drug metabolism. In this study, we aimed to develop a short hairpin RNA (shRNA to modulate CYP3A4 expression. Three new shRNAs (S1, S2 and S3 were designed to target the coding sequence (CDS of CYP3A4, cloned into a shRNA expression vector, and tested in different cells. The mixture of three shRNAs produced optimal reduction (55% in CYP3A4 CDS-luciferase activity in both CHL and HEK293 cells. Endogenous CYP3A4 expression in HepG2 cells was decreased about 50% at both mRNA and protein level after transfection of the mixture of three shRNAs. In contrast, CYP3A5 gene expression was not altered by the shRNAs, supporting the selectivity of CYP3A4 shRNAs. In addition, HepG2 cells transfected with CYP3A4 shRNAs were less sensitive to Ginkgolic acids, whose toxic metabolites are produced by CYP3A4. These results demonstrate that vector-based shRNAs could modulate CYP3A4 expression in cells through their actions on CYP3A4 CDS, and CYP3A4 shRNAs may be utilized to define the role of CYP3A4 in drug metabolism and toxicity.

  17. Inhibition of the 26S proteasome blocks progesterone receptor-dependent transcription through failed recruitment of RNA polymerase II.

    Science.gov (United States)

    Dennis, Andrew P; Lonard, David M; Nawaz, Zafar; O'Malley, Bert W

    2005-03-01

    In the present study, we investigated the involvement of protein degradation via the 26S proteasome during progesterone receptor (PR)-mediated transcription in T-47D cells containing a stably integrated MMTV-CAT reporter construct (CAT0 cells). Progesterone induced CAT and HSD11beta2 transcription while co-treatment with the proteasome inhibitor, MG132, blocked PR-induced transcription in a time-dependent fashion. MG132 treatment also inhibited transcription of beta-actin and cyclophilin, but not two proteasome subunit genes, PSMA1 and PSMC1, indicating that proteasome inhibition affects a subset of RNA polymerase II (RNAP(II))-regulated genes. Progesterone-mediated recruitment of RNAP(II) was blocked by MG132 treatment at time points later than 1 h that was not dependent on the continued presence of PR, associated cofactors, and components of the general transcription machinery, supporting the concept that proteasome-mediated degradation is needed for continued transcription. Surprisingly, progesterone-mediated acetylation of histone H4 was inhibited by MG132 with the concomitant recruitment of HDAC3, NCoR, and SMRT. We demonstrate that the steady-state protein levels of SMRT and NCoR are higher in the presence of MG132 in CAT0 cells, consistent with other reports that SMRT and NCoR are targets of the 26S proteasome. However, inhibition of histone deacetylation by trichostatin A (TSA) treatment or SMRT/NCoR knockdown by siRNA did not restore MG132-inhibited progesterone-dependent transcription. Therefore, events other than histone deacetylation and stability of SMRT and NCoR must also play a role in inhibition of PR-mediated transcription.

  18. The RNA splicing factor ASF/SF2 inhibits human topoisomerase I mediated DNA relaxation

    DEFF Research Database (Denmark)

    Andersen, Félicie Faucon; Tange, Thomas Ø.; Sinnathamby, Thayaline

    2002-01-01

    Human topoisomerase I interacts with and phosphorylates the SR-family of RNA splicing factors, including ASF/SF2, and has been suggested to play an important role in the regulation of RNA splicing. Here we present evidence to support the theory that the regulation can go the other way around...

  19. Antibiotic inhibition of the movement of tRNA substrates through a peptidyl transferase cavity

    DEFF Research Database (Denmark)

    Porse, B T; Rodriguez-Fonseca, C; Leviev, I

    1996-01-01

    The present review attempts to deal with movement of tRNA substrates through the peptidyl transferase centre on the large ribosomal subunit and to explain how this movement is interrupted by antibiotics. It builds on the concept of hybrid tRNA states forming on ribosomes and on the observed movem...

  20. Long non-coding RNA taurine upregulated 1 enhances tumor-induced angiogenesis through inhibiting microRNA-299 in human glioblastoma.

    Science.gov (United States)

    Cai, H; Liu, X; Zheng, J; Xue, Y; Ma, J; Li, Z; Xi, Z; Li, Z; Bao, M; Liu, Y

    2017-01-19

    Angiogenesis is one of the critical biological elements affecting the development and progression of cancer. Long non-coding RNAs (lncRNAs) are important regulators and aberrantly expressed in various types of human cancer. Our previous studies indicated that lncRNA taurine upregulated 1 (TUG1) implicated in the regulation of blood-tumor barrier permeability; however, its role in glioblastoma angiogenesis still unclear. Here we demonstrated that TUG1 was up-expressed in human glioblastoma tissues and glioblastoma cell lines. Knockdown of TUG1 remarkably suppressed tumor-induced endothelial cell proliferation, migration and tube formation as well as reducing spheroid-based angiogenesis ability in vitro, which are the critical steps for tumor angiogenesis. Besides, knockdown of TUG1 significantly increased the expression of mircroRNA-299 (miR-299), which was down-expressed in glioblastoma tissues and glioblastoma cell lines. Bioinformatics analysis and luciferase reporter assay revealed that TUG1 influenced tumor angiogenesis via directly binding to the miR-299 and there was a reciprocal repression between TUG1 and miR-299 in the same RNA-induced silencing complex. Moreover, knockdown of TUG1 reduced the expression of vascular endothelial growth factor A (VEGFA), which was defined as a functional downstream target of miR-299. In addition, knockdown of TUG1, shown in the in vivo studies, has effects on suppressing tumor growth, reducing tumor microvessel density and decreasing the VEGFA expression by upregulating miR-299 in xenograft glioblastoma model. Overall, the results demonstrated that TUG1 enhances tumor-induced angiogenesis and VEGF expression through inhibiting miR-299. Also, the inhibition of TUG1 could provide a novel therapeutic target for glioblastoma treatment.

  1. Inhibition of influenza A virus replication by influenza B virus nucleoprotein: An insight into interference between influenza A and B viruses

    Energy Technology Data Exchange (ETDEWEB)

    Wanitchang, Asawin; Narkpuk, Jaraspim; Jaru-ampornpan, Peera; Jengarn, Juggagarn [Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani 12120 (Thailand); Jongkaewwattana, Anan, E-mail: anan.jon@biotec.or.th [Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani 12120 (Thailand)

    2012-10-10

    Given that co-infection of cells with equivalent titers of influenza A and B viruses (FluA and FluB) has been shown to result in suppression of FluA growth, it is possible that FluB-specific proteins might hinder FluA polymerase activity and replication. We addressed this possibility by individually determining the effect of each gene of FluB on the FluA polymerase assay and found that the nucleoprotein of FluB (NP{sub FluB}) inhibits polymerase activity of FluA in a dose-dependent manner. Mutational analyses of NP{sub FluB} suggest that functional NP{sub FluB} is necessary for this inhibition. Slower growth of FluA was also observed in MDCK cells stably expressing NP{sub FluB}. Further analysis of NP{sub FluB} indicated that it does not affect nuclear import of NP{sub FluA}. Taken together, these findings suggest a novel role of NP{sub FluB} in inhibiting replication of FluA, providing more insights into the mechanism of interference between FluA and FluB and the lack of reassortants between them.

  2. Conserved Proteins of the RNA Interference System in the Arbuscular Mycorrhizal Fungus Rhizoglomus irregulare Provide New Insight into the Evolutionary History of Glomeromycota.

    Science.gov (United States)

    Lee, Soon-Jae; Kong, Mengxuan; Harrison, Paul; Hijri, Mohamed

    2018-01-01

    Horizontal gene transfer (HGT) is an important mechanism in the evolution of many living organisms particularly in Prokaryotes where genes are frequently dispersed between taxa. Although, HGT has been reported in Eukaryotes, its accumulative effect and its frequency has been questioned. Arbuscular mycorrhizal fungi (AMF) are an early diverged fungal lineage belonging to phylum Glomeromycota, whose phylogenetic position is still under debate. The history of AMF and land plant symbiosis dates back to at least 460 Ma. However, Glomeromycota are estimated to have emerged much earlier than land plants. In this study, we surveyed genomic and transcriptomic data of the model arbuscular mycorrhizal fungus Rhizoglomus irregulare (synonym Rhizophagus irregularis) and its relatives to search for evidence of HGT that occurred during AMF evolution. Surprisingly, we found a signature of putative HGT of class I ribonuclease III protein-coding genes that occurred from autotrophic cyanobacteria genomes to R. irregulare. At least one of two HGTs was conserved among AMF species with high levels of sequence similarity. Previously, an example of intimate symbiosis between AM fungus and cyanobacteria was reported in the literature. Ribonuclease III family enzymes are important in small RNA regulation in Fungi together with two additional core proteins (Argonaute/piwi and RdRP). The eukaryotic RNA interference system found in AMF was conserved and showed homology with high sequence similarity in Mucoromycotina, a group of fungi closely related to Glomeromycota. Prior to this analysis, class I ribonuclease III has not been identified in any eukaryotes. Our results indicate that a unique acquisition of class I ribonuclease III in AMF is due to a HGT event that occurred from cyanobacteria to Glomeromycota, at the latest before the divergence of the two Glomeromycota orders Diversisporales and Glomerales. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society

  3. Postexposure protection of non-human primates against a lethal Ebola virus challenge with RNA interference: a proof-of-concept study.

    Science.gov (United States)

    Geisbert, Thomas W; Lee, Amy C H; Robbins, Marjorie; Geisbert, Joan B; Honko, Anna N; Sood, Vandana; Johnson, Joshua C; de Jong, Susan; Tavakoli, Iran; Judge, Adam; Hensley, Lisa E; Maclachlan, Ian

    2010-05-29

    We previously showed that small interfering RNAs (siRNAs) targeting the Zaire Ebola virus (ZEBOV) RNA polymerase L protein formulated in stable nucleic acid-lipid particles (SNALPs) completely protected guineapigs when administered shortly after a lethal ZEBOV challenge. Although rodent models of ZEBOV infection are useful for screening prospective countermeasures, they are frequently not useful for prediction of efficacy in the more stringent non-human primate models. We therefore assessed the efficacy of modified non-immunostimulatory siRNAs in a uniformly lethal non-human primate model of ZEBOV haemorrhagic fever. A combination of modified siRNAs targeting the ZEBOV L polymerase (EK-1 mod), viral protein (VP) 24 (VP24-1160 mod), and VP35 (VP35-855 mod) were formulated in SNALPs. A group of macaques (n=3) was given these pooled anti-ZEBOV siRNAs (2 mg/kg per dose, bolus intravenous infusion) after 30 min, and on days 1, 3, and 5 after challenge with ZEBOV. A second group of macaques (n=4) was given the pooled anti-ZEBOV siRNAs after 30 min, and on days 1, 2, 3, 4, 5, and 6 after challenge with ZEBOV. Two (66%) of three rhesus monkeys given four postexposure treatments of the pooled anti-ZEBOV siRNAs were protected from lethal ZEBOV infection, whereas all macaques given seven postexposure treatments were protected. The treatment regimen in the second study was well tolerated with minor changes in liver enzymes that might have been related to viral infection. This complete postexposure protection against ZEBOV in non-human primates provides a model for the treatment of ZEBOV-induced haemorrhagic fever. These data show the potential of RNA interference as an effective postexposure treatment strategy for people infected with Ebola virus, and suggest that this strategy might also be useful for treatment of other emerging viral infections. Defense Threat Reduction Agency. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Inhibition of herpes simplex virus infection by lactoferrin is dependent on interference with the virus binding to glycosaminoglycans

    International Nuclear Information System (INIS)

    Marchetti, Magda; Trybala, Edward; Superti, Fabiana; Johansson, Maria; Bergstroem, Tomas

    2004-01-01

    Previous reports have indicated that lactoferrin inhibits herpes simplex virus (HSV) infection during the very early phases of the viral replicative cycle. In the present work we investigated the mechanism of the antiviral activity of lactoferrin in mutant glycosaminoglycan (GAG)-deficient cells. Bovine lactoferrin (BLf) was a strong inhibitor of HSV-1 infection in cells expressing either heparan sulfate (HS) or chondroitin sulfate (CS) or both, but was ineffective or less efficient in GAG-deficient cells or in cells treated with GAG-degrading enzymes. In contrast to wild-type HSV-1, virus mutants devoid of glycoprotein C (gC) were significantly less inhibited by lactoferrin in GAG-expressing cells, indicating that lactoferrin interfered with the binding of viral gC to cell surface HS and/or CS. Finally, we demonstrated that lactoferrin bound directly to both HS and CS isolated from surfaces of the studied cells, as well as to commercial preparations of GAG chains. The results support the hypothesis that the inhibition of HSV-1 infectivity by lactoferrin is dependent on its interaction with cell surface GAG chains of HS and CS

  5. Inhibition of HIV transmission in human cervicovaginal explants and humanized mice using CD4 aptamer-siRNA chimeras

    Science.gov (United States)

    Wheeler, Lee Adam; Trifonova, Radiana; Vrbanac, Vladimir; Basar, Emre; McKernan, Shannon; Xu, Zhan; Seung, Edward; Deruaz, Maud; Dudek, Tim; Einarsson, Jon Ivar; Yang, Linda; Allen, Todd M.; Luster, Andrew D.; Tager, Andrew M.; Dykxhoorn, Derek M.; Lieberman, Judy

    2011-01-01

    The continued spread of the HIV epidemic underscores the need to interrupt transmission. One attractive strategy is a topical vaginal microbicide. Sexual transmission of herpes simplex virus type 2 (HSV-2) in mice can be inhibited by intravaginal siRNA application. To overcome the challenges of knocking down gene expression in immune cells susceptible to HIV infection, we used chimeric RNAs composed of an aptamer fused to an siRNA for targeted gene knockdown in cells bearing an aptamer-binding receptor. Here, we showed that CD4 aptamer-siRNA chimeras (CD4-AsiCs) specifically suppress gene expression in CD4+ T cells and macrophages in vitro, in polarized cervicovaginal tissue explants, and in the female genital tract of humanized mice. CD4-AsiCs do not activate lymphocytes or stimulate innate immunity. CD4-AsiCs that knock down HIV genes and/or CCR5 inhibited HIV infection in vitro and in tissue explants. When applied intravaginally to humanized mice, CD4-AsiCs protected against HIV vaginal transmission. Thus, CD4-AsiCs could be used as the active ingredient of a microbicide to prevent HIV sexual transmission. PMID:21576818

  6. Selective and specific inhibition of the plasmodium falciparum lysyl-tRNA synthetase by the fungal secondary metabolite cladosporin.

    Science.gov (United States)

    Hoepfner, Dominic; McNamara, Case W; Lim, Chek Shik; Studer, Christian; Riedl, Ralph; Aust, Thomas; McCormack, Susan L; Plouffe, David M; Meister, Stephan; Schuierer, Sven; Plikat, Uwe; Hartmann, Nicole; Staedtler, Frank; Cotesta, Simona; Schmitt, Esther K; Petersen, Frank; Supek, Frantisek; Glynne, Richard J; Tallarico, John A; Porter, Jeffrey A; Fishman, Mark C; Bodenreider, Christophe; Diagana, Thierry T; Movva, N Rao; Winzeler, Elizabeth A

    2012-06-14

    With renewed calls for malaria eradication, next-generation antimalarials need be active against drug-resistant parasites and efficacious against both liver- and blood-stage infections. We screened a natural product library to identify inhibitors of Plasmodium falciparum blood- and liver-stage proliferation. Cladosporin, a fungal secondary metabolite whose target and mechanism of action are not known for any species, was identified as having potent, nanomolar, antiparasitic activity against both blood and liver stages. Using postgenomic methods, including a yeast deletion strains collection, we show that cladosporin specifically inhibits protein synthesis by directly targeting P. falciparum cytosolic lysyl-tRNA synthetase. Further, cladosporin is >100-fold more potent against parasite lysyl-tRNA synthetase relative to the human enzyme, which is conferred by the identity of two amino acids within the enzyme active site. Our data indicate that lysyl-tRNA synthetase is an attractive, druggable, antimalarial target that can be selectively inhibited. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Oligonucleotides targeting TCF4 triplet repeat expansion inhibit RNA foci and mis-splicing in Fuchs' dystrophy.

    Science.gov (United States)

    Hu, Jiaxin; Rong, Ziye; Gong, Xin; Zhou, Zhengyang; Sharma, Vivek K; Xing, Chao; Watts, Jonathan K; Corey, David R; Mootha, V Vinod

    2018-03-15

    Fuchs' endothelial corneal dystrophy (FECD) is the most common repeat expansion disorder. FECD impacts 4% of U.S. population and is the leading indication for corneal transplantation. Most cases are caused by an expanded intronic CUG tract in the TCF4 gene that forms nuclear foci, sequesters splicing factors and impairs splicing. We investigated the sense and antisense RNA landscape at the FECD gene and find that the sense-expanded repeat transcript is the predominant species in patient corneas. In patient tissue, sense foci number were negatively correlated with age and showed no correlation with sex. Each endothelial cell has ∼2 sense foci and each foci is single RNA molecule. We designed antisense oligonucleotides (ASOs) to target the mutant-repetitive RNA and demonstrated potent inhibition of foci in patient-derived cells. Ex vivo treatment of FECD human corneas effectively inhibits foci and reverses pathological changes in splicing. FECD has the potential to be a model for treating many trinucleotide repeat diseases and targeting the TCF4 expansion with ASOs represents a promising therapeutic strategy to prevent and treat FECD.

  8. Targeted Inhibition of the miR-199a/214 Cluster by CRISPR Interference Augments the Tumor Tropism of Human Induced Pluripotent Stem Cell-Derived Neural Stem Cells under Hypoxic Condition

    Directory of Open Access Journals (Sweden)

    Yumei Luo

    2016-01-01

    Full Text Available The human induced pluripotent stem cell (hiPSC provides a breakthrough approach that helps overcoming ethical and allergenic challenges posed in application of neural stem cells (NSCs in targeted cancer gene therapy. However, the tumor-tropic capacity of hiPSC-derived NSCs (hiPS-NSCs still has much room to improve. Here we attempted to promote the tumor tropism of hiPS-NSCs by manipulating the activity of endogenous miR-199a/214 cluster that is involved in regulation of hypoxia-stimulated cell migration. We first developed a baculovirus-delivered CRISPR interference (CRISPRi system that sterically blocked the E-box element in the promoter of the miR-199a/214 cluster with an RNA-guided catalytically dead Cas9 (dCas9. We then applied this CRISPRi system to hiPS-NSCs and successfully suppressed the expression of miR-199a-5p, miR-199a-3p, and miR-214 in the microRNA gene cluster. Meanwhile, the expression levels of their targets related to regulation of hypoxia-stimulated cell migration, such as HIF1A, MET, and MAPK1, were upregulated. Further migration assays demonstrated that the targeted inhibition of the miR-199a/214 cluster significantly enhanced the tumor tropism of hiPS-NSCs both in vitro and in vivo. These findings suggest a novel application of CRISPRi in NSC-based tumor-targeted gene therapy.

  9. Conditional RNA interference achieved by Oct-1 POU/rtTA fusion protein activator and a modified TRE-mouse U6 promoter

    International Nuclear Information System (INIS)

    Fei Zhaoliang; Chen Zheng; Wang Zhugang; Fei Jian

    2007-01-01

    RNA interference (RNAi) is a powerful technique and is widely used to down-regulate expression of specific genes in cultured cells and in vivo. In this paper, we report our development of a new tetracycline-inducible RNAi expression using a modified TRE-mouse U6 promoter in which the distal sequence element (DSE) was replaced by the tetracycline-responsive element (TRE). The modified TRE-mouse U6 promoter can be activated by a Tet-on version tetracycline-regulated artificial activator rTetOct which was constructed by fusing the rtTA DNA binding domain with the Oct-1 POU activation domain. This rTetOct/TRE-U6 system was successfully applied to conditionally and reversibly down-regulate the expression of endogenous p53 gene in MCF7 cells, and the expression of β-defensin gene (mBin1b) either transiently expressed in COS7 cells or stably expressed in CHO cells

  10. A whole genome screening and RNA interference identify a juvenile hormone esterase-like gene of the diamondback moth, Plutella xylostella.

    Science.gov (United States)

    Gu, Xiaojun; Kumar, Sunil; Kim, Eunjin; Kim, Yonggyun

    2015-09-01

    Juvenile hormone (JH) plays a crucial role in preventing precocious metamorphosis and stimulating reproduction. Thus, its hemolymph titer should be under a tight control. As a negative controller, juvenile hormone esterase (JHE) performs a rapid breakdown of residual JH in the hemolymph during last instar to induce a larval-to-pupal metamorphosis. A whole genome of the diamondback moth (DBM), Plutella xylostella, has been annotated and proposed 11 JHE candidates. Sequence analysis using conserved motifs commonly found in other JHEs proposed a putative JHE (Px004817). Px004817 (64.61 kDa, pI=5.28) exhibited a characteristic JHE expression pattern by showing high peak at the early last instar, at which JHE enzyme activity was also at a maximal level. RNA interference of Px004817 reduced JHE activity and interrupted pupal development with a significant increase of larval period. This study identifies Px004817 as a JHE-like gene of P. xylostella. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Loss-of-function analyses of the fragile X-related and dopamine receptor genes by RNA interference in the cricket Gryllus bimaculatus.

    Science.gov (United States)

    Hamada, Aska; Miyawaki, Katsuyuki; Honda-sumi, Eri; Tomioka, Kenji; Mito, Taro; Ohuchi, Hideyo; Noji, Sumihare

    2009-08-01

    In order to explore a possibility that the cricket Gryllus bimaculatus would be a useful model to unveil molecular mechanisms of human diseases, we performed loss-of-function analyses of Gryllus genes homologous to human genes that are responsible for human disorders, fragile X mental retardation 1 (fmr1) and Dopamine receptor (DopR). We cloned cDNAs of their Gryllus homologues, Gb'fmr1, Gb'DopRI, and Gb'DopRII, and analyzed their functions with use of nymphal RNA interference (RNAi). For Gb'fmr1, three major phenotypes were observed: (1) abnormal wing postures, (2) abnormal calling song, and (3) loss of the circadian locomotor rhythm, while for Gb'DopRI, defects of wing posture and morphology were found. These results indicate that the cricket has the potential to become a novel model system to explore human neuronal pathogenic mechanisms and to screen therapeutic drugs by RNAi. Copyright (c) 2009 Wiley-Liss, Inc.

  12. AGO1, QDE-2, and RDE-1 are related proteins required for post-transcriptional gene silencing in plants, quelling in fungi, and RNA interference in animals.

    Science.gov (United States)

    Fagard, M; Boutet, S; Morel, J B; Bellini, C; Vaucheret, H

    2000-10-10

    Introduction of transgene DNA may lead to specific degradation of RNAs that are homologous to the transgene transcribed sequence through phenomena named post-transcriptional gene silencing (PTGS) in plants, quelling in fungi, and RNA interference (RNAi) in animals. It was shown previously that PTGS, quelling, and RNAi require a set of related proteins (SGS2, QDE-1, and EGO-1, respectively). Here we report the isolation of Arabidopsis mutants impaired in PTGS which are affected at the Argonaute1 (AGO1) locus. AGO1 is similar to QDE-2 required for quelling and RDE-1 required for RNAi. Sequencing of ago1 mutants revealed one amino acid essential for PTGS that is also present in QDE-2 and RDE-1 in a highly conserved motif. Taken together, these results confirm the hypothesis that these processes derive from a common ancestral mechanism that controls expression of invading nucleic acid molecules at the post-transcriptional level. As opposed to rde-1 and qde-2 mutants, which are viable, ago1 mutants display several developmental abnormalities, including sterility. These results raise the possibility that PTGS, or at least some of its elements, could participate in the regulation of gene expression during development in plants.

  13. RNA Interference of 1-Aminocyclopropane-1-carboxylic Acid Oxidase (ACO1 and ACO2 Genes Expression Prolongs the Shelf Life of Eksotika (Carica papaya L. Papaya Fruit

    Directory of Open Access Journals (Sweden)

    Rogayah Sekeli

    2014-06-01

    Full Text Available The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6. Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.

  14. Israeli Acute Paralysis Virus Infection Leads to an Enhanced RNA Interference Response and Not Its Suppression in the Bumblebee Bombus terrestris

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    Kaat Cappelle

    2016-12-01

    Full Text Available RNA interference (RNAi is the primary antiviral defense system in insects and its importance for pollinator health is indisputable. In this work, we examined the effect of Israeli acute paralysis virus (IAPV infection on the RNAi process in the bumblebee, Bombus terrestris, and whether the presence of possible functional viral suppressors could alter the potency of the host’s immune response. For this, a two-fold approach was used. Through a functional RNAi assay, we observed an enhancement of the RNAi system after IAPV infection instead of its suppression, despite only minimal upregulation of the genes involved in RNAi. Besides, the presence of the proposed suppressor 1A and the predicted OrfX protein in IAPV could not be confirmed using high definition mass spectrometry. In parallel, when bumblebees were infected with cricket paralysis virus (CrPV, known to encode a suppressor of RNAi, no increase in RNAi efficiency was seen. For both viruses, pre-infection with the one virus lead to a decreased replication of the other virus, indicating a major effect of competition. These results are compelling in the context of Dicistroviridae in multi-virus/multi-host networks as the effect of a viral infection on the RNAi machinery may influence subsequent virus infections.

  15. Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR.

    Science.gov (United States)

    Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V; Lokugamage, Nandadeva; Head, Jennifer A; Ikegami, Tetsuro

    2013-01-20

    Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general transcription including IFN-β gene inhibition. MP-12 NSs but not R173A NSs binds to wt PKR. R173A NSs formed filamentous structure in nucleus in a mosaic pattern, which was distinct from MP-12 NSs filament pattern. Due to early phosphorylation of eIF2α, rMP12-NSsR173A could not efficiently accumulate viral proteins. Our results suggest that NSs-mediated host general transcription suppression occurs independently of PKR degradation, while the PKR degradation is important to inhibit the phosphorylation of eIF2α in infected cells undergoing host general transcription suppression. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. MicroRNA-532 and microRNA-3064 inhibit cell proliferation and invasion by acting as direct regulators of human telomerase reverse transcriptase in ovarian cancer.

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    Lin Bai

    Full Text Available Human telomerase reverse transcriptase (hTERT plays a crucial role in ovarian cancer (OC progression. However, the mechanisms underlying hTERT upregulation in OC, and the specific microRNAs (miRNAs involved in the regulation of hTERT in OC cells, remains unclear. We performed a bioinformatics search to identify potential miRNAs that bind to the 3'-untranslated region (3'-UTR region of the hTERT mRNA. We examined the expression levels of miR-532/miR-3064 in OC tissues and normal ovarian tissues, and analyzed the correlation between miRNA expression and OC patient outcomes. The impacts of miR-532/miR-3064 on hTERT expression were evaluated by western blot analysis and hTERT 3'-UTR reporter assays. We investigated the effects of miR-532/miR-3064 on proliferation and invasion in OC cells. We found that miR-532 and miR-3064 are down-regulated in OC specimens. We observed a significant association between reduced miR-532/miR-3064 expression and poorer survival of patients with OC. We confirmed that in OC cells, these two miRNAs downregulate hTERT levels by directly targeting its 3'-UTR region, and inhibited proliferation, EMT and invasion of OC cells. In addition, the overexpression of the hTERT cDNA lacking the 3'-UTR partially restored miR-532/miR-3064-inhibited OC cell proliferation and invasion. The silencing of hTERT by siRNA oligonucleotides abolished these malignant features, and phenocopied the effects of miR-532/miR-3064 overexpression. Furthermore, overexpression of miR-532/miR-3064 inhibits the growth of OC cells in vivo. Our findings demonstrate a miR-532/miR-3064-mediated mechanism responsible for hTERT upregulation in OC cells, and reveal a possibility of targeting miR-532/miR-3064 for future treatment of OC.

  17. Expression of human ARGONAUTE 2 inhibits endogenous microRNA activity in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Ira eDeveson

    2013-04-01

    Full Text Available Plant and animal microRNA (miRNA pathways share many analogous components, the ARGONAUTE (AGO proteins being foremost among them. We sought to ascertain the degree of functional conservation shared by Homo sapiens ARGONAUTE 2 (HsAGO2 and Arabidopsis thaliana ARGONAUTE 1 (AtAGO1, which are the predominant AGO family members involved with miRNA activity in their respective species. Transgenic Arabidopsis plants expressing HsAGO2 were indistinguishable from counterparts over-expressing AtAGO1, each group exhibiting the morphological and molecular hallmarks of miRNA-pathway loss-of-function alleles. However, unlike AtAGO1, HsAGO2 was unable to rescue the ago1-27 allele. We conclude that, despite the evolutionary gulf between them, HsAGO2 is likely capable of interacting with some component/s of the Arabidopsis miRNA pathway, thereby perturbing its operation, although differences have arisen such that HsAGO2 alone is insufficient to confer efficient silencing of miRNA targets in planta.

  18. RNA-mediated gene silencing in Candida albicans: inhibition of hyphae formation by use of RNAi technology.

    Science.gov (United States)

    Moazeni, Maryam; Khoramizadeh, Mohammad Reza; Kordbacheh, Parivash; Sepehrizadeh, Zargham; Zeraati, Hojat; Noorbakhsh, Fatemeh; Teimoori-Toolabi, Ladan; Rezaie, Sassan

    2012-09-01

    The introduction of RNA silencing machinery in fungi has led to the promising application of RNAi methodology to knock down essential vital factor or virulence factor genes in the microorganisms. Efg1p is required for development of a true hyphal growth form which is known to be essential for interactions with human host cells and for the yeast's pathogenesis. In this paper, we describe the development of a system for presenting and studying the RNAi function on the EFG1 gene in C. albicans. The 19-nucleotide siRNA was designed on the basis of the cDNA sequence of the EFG1 gene in C. albicans and transfection was performed by use of a modified-PEG/LiAc method. To investigate EFG1 gene silencing in siRNA-treated cells, the yeasts were grown in human serum; to induce germ tubes a solid medium was used with the serum. Quantitative changes in expression of the EFG1 gene were analyzed by measuring the cognate EFG1 mRNA level by use of a quantitative real-time RT-PCR assay. Compared with the positive control, true hyphae formation was significantly reduced by siRNA at concentrations of 1 μM, 500 nM, and 100 nM (P < 0.05). In addition, siRNA at a concentration of 1 μM was revealed to inhibit expression of the EFG1 gene effectively (P < 0.05). On the basis of the potential of post-transcriptional gene silencing to control the expression of specific genes, these techniques may be regarded as promising means of drug discovery, with applications in biomedicine and functional genomics analysis.

  19. An oligonucleotide complementary to the SL-B1 domain in the 3'-end of the minus-strand RNA of the hepatitis C virus inhibits in vitro initiation of RNA synthesis by the viral polymerase

    International Nuclear Information System (INIS)

    Reigadas, Sandrine; Ventura, Michel; Andreola, Marie-Line; Michel, Justine; Gryaznov, Sergei; Tarrago-Litvak, Laura; Litvak, Simon; Astier-Gin, Therese

    2003-01-01

    We describe oligonucleotides (ODNs) that inhibit hepatitis C virus (HCV) RNA synthesis in vitro. From a series of 13 ODNs complementary to the 3'-end of the minus-strand HCV RNA, only 4 inhibited RNA synthesis with IC 50 values lower than 1 μM. The inhibition was sequence-specific, since no effect was observed when the ODNs were used with a noncomplementary template. The introduction of a 2'-O-methyl modification increased the inhibitor activity 11-fold (IC 50 = 50 nM) in just 1 (ODN7) of the 4 inhibitory ODNs. ODNs did not inhibit RNA synthesis by interfering with the elongation process as no short RNAs products were detected. We also show that ODN7 did not prevent binding of NS5B to the template or cause polymerase trapping by the duplex RNA/ODN. Our data demonstrate that ODN7 inhibits the initiation process, most probably by modifying structural features present at the 3'-end of the minus-strand RNA

  20. Tumor-targeted inhibition by a novel strategy - mimoretrovirus expressing siRNA targeting the Pokemon gene.

    Science.gov (United States)

    Tian, Zhiqiang; Wang, Huaizhi; Jia, Zhengcai; Shi, Jinglei; Tang, Jun; Mao, Liwei; Liu, Hongli; Deng, Yijing; He, Yangdong; Ruan, Zhihua; Li, Jintao; Wu, Yuzhang; Ni, Bing

    2010-12-01

    Pokemon gene has crucial but versatile functions in cell differentiation, proliferation and tumorigenesis. It is a master regulator of the ARF-HDM2-p53 and Rb-E2F pathways. The facts that the expression of Pokemon is essential for tumor formation and many kinds of tumors over-express the Pokemon gene make it an attractive target for therapeutic intervention for cancer treatment. In this study, we used an RNAi strategy to silence the Pokemon gene in a cervical cancer model. To address the issues involving tumor specific delivery and durable expression of siRNA, we applied the Arg-Gly-Asp (RGD) peptide ligand and polylysine (K(18)) fusion peptide to encapsulate a recombinant retrovirus plasmid expressing a siRNA targeting the Pokemon gene and produced the 'mimoretrovirus'. At charge ratio 2.0 of fusion peptide/plasmid, the mimoretrovirus formed stable and homogenous nanoparticles, and provided complete DNase I protection and complete gel retardation. This nanoparticle inhibited SiHa cell proliferation and invasion, while it promoted SiHa cell apoptosis. The binding of the nanoparticle to SiHa cells was mediated via the RGD-integrin α(v)β(3) interaction, as evidenced by the finding that unconjugated RGD peptide inhibited this binding significantly. This tumor-targeting mimoretrovirus exhibited excellent anti-tumor capacity in vivo in a nude mouse model. Moreover, the mimoretrovirus inhibited tumor growth with a much higher efficiency than recombinant retrovirus expressing siRNA or the K(18)/P4 nanoparticle lacking the RGD peptide. Results suggest that the RNAi/RGD-based mimoretrovirus developed in this study represents a novel anti-tumor strategy that may be applicable to most research involving cancer therapy and, thus, has promising potential as a cervical cancer treatment.

  1. Inhibition of bovine viral diarrhea virus RNA synthesis by thiosemicarbazone derived from 5,6-dimethoxy-1-indanone.

    Science.gov (United States)

    Castro, Eliana F; Fabian, Lucas E; Caputto, María E; Gagey, Dolores; Finkielsztein, Liliana M; Moltrasio, Graciela Y; Moglioni, Albertina G; Campos, Rodolfo H; Cavallaro, Lucía V

    2011-06-01

    In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV).

  2. Inhibition of Bovine Viral Diarrhea Virus RNA Synthesis by Thiosemicarbazone Derived from 5,6-Dimethoxy-1-Indanone▿

    Science.gov (United States)

    Castro, Eliana F.; Fabian, Lucas E.; Caputto, María E.; Gagey, Dolores; Finkielsztein, Liliana M.; Moltrasio, Graciela Y.; Moglioni, Albertina G.; Campos, Rodolfo H.; Cavallaro, Lucía V.

    2011-01-01

    In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV). PMID:21430053

  3. Hamowanie syntezy chlorofilu i RNA w izolowanych liścieniach ogórka przez N-hydroksymocznik [Inhibition of chlorophyll and RNA synthesis by N-hydroxyurea in detached cucumber cotyledons

    Directory of Open Access Journals (Sweden)

    A. Rennert

    2015-01-01

    Full Text Available N-hydroxyurea (HU at the concentration of 5 x 10-4 M decreased the content of chlorophyll in detached cucumber cotyledons; at this concentration it has no inhibitory effect on growth. Benzylaminopurine, gibberelic acid and KCl partially reversed the inhibitory effect of HU on chlorophyll synthesis. HU stimulated yellowing of barley first leaf sections. The compound had little effect on leucine-14C incorporation to protein, and markedly inhibited uracil-14C incorporation in to RNA of the greening cucumber cotyledons. It is suggested that the inhibition of RNA and chlorophyll synthesis in HU-treated cucumber cotyledons follows the HU-dependent inhibition of DNA replication.

  4. Small interfering RNA targeted to stem-loop II of the 5' untranslated region effectively inhibits expression of six HCV genotypes

    Directory of Open Access Journals (Sweden)

    Dash Srikanta

    2006-11-01

    Full Text Available Abstract Background The antiviral action of interferon alpha targets the 5' untranslated region (UTR used by hepatitis C virus (HCV to translate protein by an internal ribosome entry site (IRES mechanism. Although this sequence is highly conserved among different clinical strains, approximately half of chronically infected hepatitis C patients do not respond to interferon therapy. Therefore, development of small interfering RNA (siRNA targeted to the 5'UTR to inhibit IRES mediated translation may represent an alternative approach that could circumvent the problem of interferon resistance. Results Four different plasmid constructs were prepared for intracellular delivery of siRNAs targeting the stem loop II-III of HCV 5' UTR. The effect of siRNA production on IRES mediated translation was investigated using chimeric clones between the gene for green fluorescence protein (GFP and IRES sequences of six different HCV genotypes. The siRNA targeted to stem loop II effectively mediated degradation of HCV IRES mRNA and inhibited GFP expression in the case of six different HCV genotypes, where as siRNAs targeted to stem loop III did not. Furthermore, intracytoplasmic expression of siRNA into transfected Huh-7 cells efficiently degraded HCV genomic RNA and inhibited core protein expression from infectious full-length infectious clones HCV 1a and HCV 1b strains. Conclusion These in vitro studies suggest that siRNA targeted to stem-loop II is highly effective inhibiting IRES mediated translation of the major genotypes of HCV. Stem-loop II siRNA may be a good target for developing an intracellular immunization strategy based antiviral therapy to inhibit hepatitis C virus strains that are not inhibited by interferon.

  5. Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway.

    Science.gov (United States)

    Lakhan, Ram; Said, Hamid M

    2017-04-01

    Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been delineated, nothing is known about the effect of LPS on the process. We addressed this issue using in vitro (human colonic epithelial NCM460 cells) and in vivo (mice) models of LPS exposure. Treating NCM460 cells with LPS was found to lead to a significant inhibition in carrier-mediated biotin uptake. Similarly, administration of LPS to mice led to a significant inhibition in biotin uptake by native colonic tissue. Although no changes in total cellular SMVT protein and mRNA levels were observed, LPS caused a decrease in the fraction of SMVT expressed at the cell surface. A role for casein kinase 2 (CK2) (whose activity was also inhibited by LPS) in mediating the endotoxin effects on biotin uptake and on membrane expression of SMVT was suggested by findings that specific inhibitors of CK2, as well as mutating the putative CK2 phosphorylation site (Thr 78 Ala) in the SMVT protein, led to inhibition in biotin uptake and membrane expression of SMVT. This study shows for the first time that LPS inhibits colonic biotin uptake via decreasing membrane expression of its transporter and that these effects likely involve a CK2-mediated pathway.

  6. Extract of Stellerachamaejasme L(ESC) inhibits growth and metastasis of human hepatocellular carcinoma via regulating microRNA expression.

    Science.gov (United States)

    Liu, Xiaoni; Wang, Shuang; Xu, Jianji; Kou, Buxin; Chen, Dexi; Wang, Yajie; Zhu, Xiaoxin

    2018-03-20

    MicroRNAs(miRNAs)are involved in the initiation and progression of hepatocellular carcinoma. ESC, an extract of Stellerachamaejasme L, had been confirmed as a potential anti-tumor extract of Traditional Chinese Medicine. In light of the important role of miRNAs in hepatocellular carcinoma, we questioned whether the inhibitory effects of ESC on hepatocellular carcinoma (HCC) were associated with miRNAs. The proliferation inhibition of ESC on HCC cells was measured with MTT assay. The migration inhibition of ESC on HCC cells was measured with transwell assay. The influences of ESC on growth and metastasis inhibition were evaluated with xenograft tumor model of HCC. Protein expressions were measured with western blot and immunofluorescence methods and miRNA profiles were detected with miRNA array. Differential miRNA and target mRNAs were verified with real-time PCR. The results showed that ESC could inhibit proliferation and epithelial mesenchymal transition (EMT) in HCC cells in vitro and tumor growth and metastasis in xenograft models in vivo. miRNA array results showed that 69 differential miRNAs in total of 429 ones were obtained in MHCC97H cells treated by ESC. hsa-miR-107, hsa-miR-638, hsa-miR-106b-5p were selected to be validated with real-time PCR method in HepG2 and MHCC97H cells. Expressions of hsa-miR-107 and hsa-miR-638 increased obviously in HCC cells treated by ESC. Target genes of three miRNAs were also validated with real-time PCR. Interestingly, only target genes of hsa-miR-107 changed greatly. ESC downregulated the MCL1, SALL4 and BCL2 gene expressions significantly but did not influence the expression of CACNA2D1. The findings suggested ESC regressed growth and metastasis of human hepatocellular carcinoma via regulating microRNAs expression and their corresponding target genes.

  7. RNA-Based TWIST1 Inhibition via Dendrimer Complex to Reduce Breast Cancer Cell Metastasis

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    James Finlay

    2015-01-01

    Full Text Available Breast cancer is the leading cause of cancer-related deaths among women in the United States, and survival rates are lower for patients with metastases and/or triple-negative breast cancer (TNBC; ER, PR, and Her2 negative. Understanding the mechanisms of cancer metastasis is therefore crucial to identify new therapeutic targets and develop novel treatments to improve patient outcomes. A potential target is the TWIST1 transcription factor, which is often overexpressed in aggressive breast cancers and is a master regulator of cellular migration through epithelial-mesenchymal transition (EMT. Here, we demonstrate an siRNA-based TWIST1 silencing approach with delivery using a modified poly(amidoamine (PAMAM dendrimer. Our results demonstrate that SUM1315 TNBC cells efficiently take up PAMAM-siRNA complexes, leading to significant knockdown of TWIST1 and EMT-related target genes. Knockdown lasts up to one week after transfection and leads to a reduction in migration and invasion, as determined by wound healing and transwell assays. Furthermore, we demonstrate that PAMAM dendrimers can deliver siRNA to xenograft orthotopic tumors and siRNA remains in the tumor for at least four hours after treatment. These results suggest that further development of dendrimer-based delivery of siRNA for TWIST1 silencing may lead to a valuable adjunctive therapy for patients with TNBC.

  8. Diverging affinity of tospovirus RNA silencing suppressor proteins, NSs, for various RNA duplex molecules.

    Science.gov (United States)

    Schnettler, Esther; Hemmes, Hans; Huismann, Rik; Goldbach, Rob; Prins, Marcel; Kormelink, Richard

    2010-11-01

    The tospovirus NSs protein was previously shown to suppress the antiviral RNA silencing mechanism in plants. Here the biochemical analysis of NSs proteins from different tospoviruses, using purified NSs or NSs containing cell extracts, is described. The results showed that all tospoviral NSs proteins analyzed exhibited affinity to small double-stranded RNA molecules, i.e., small interfering RNAs (siRNAs) and micro-RNA (miRNA)/miRNA* duplexes. Interestingly, the NSs proteins from tomato spotted wilt virus (TSWV), impatiens necrotic spot virus (INSV), and groundnut ringspot virus (GRSV) also showed affinity to long double-stranded RNA (dsRNA), whereas tomato yellow ring virus (TYRV) NSs did not. The TSWV NSs protein was shown to be capable of inhibiting Dicer-mediated cleavage of long dsRNA in vitro. In addition, it suppressed the accumulation of green fluorescent protein (GFP)-specific siRNAs during coinfiltration with an inverted-repeat-GFP RNA construct in Nicotiana benthamiana. In vivo interference of TSWV NSs in the miRNA pathway was shown by suppression of an enhanced GFP (eGFP) miRNA sensor construct. The ability to stabilize miRNA/miRNA* by different tospovirus NSs proteins in vivo was demonstrated by increased accumulation and detection of both miRNA171c and miRNA171c* in tospovirus-infected N. benthamiana. All together, these data suggest that tospoviruses interfere in the RNA silencing pathway by sequestering siRNA and miRNA/miRNA* molecules before they are uploaded into their respective RNA-induced silencing complexes. The observed affinity to long dsRNA for only a subset of the tospoviruses studied is discussed in light of evolutional divergence and their ancestral relation to the animal-infecting members of the Bunyaviridae.

  9. Liver microRNA-21 is overexpressed in non-alcoholic steatohepatitis and contributes to the disease in experimental models by inhibiting PPARα expression

    Science.gov (United States)

    Loyer, Xavier; Paradis, Valérie; Hénique, Carole; Vion, Anne-Clémence; Colnot, Nathalie; Guerin, Coralie L; Devue, Cécile; On, Sissi; Scetbun, Jérémy; Romain, Mélissa; Paul, Jean-Louis; Rothenberg, Marc E; Marcellin, Patrick; Durand, François; Bedossa, Pierre; Prip-Buus, Carina; Baugé, Eric; Staels, Bart; Boulanger, Chantal M; Tedgui, Alain; Rautou, Pierre-Emmanuel

    2016-01-01

    Objective Previous studies suggested that microRNA-21 may be upregulated in the liver in non-alcoholic steatohepatitis (NASH), but its role in the development of this disease remains unknown. This study aimed to determine the role of microRNA-21 in NASH. Design We inhibited or suppressed microRNA-21 in different mouse models of NASH: (a) low-density lipoprotein receptor-deficient (Ldlr−/−) mice fed a high-fat diet and treated with antagomir-21 or antagomir control; (b) microRNA-21-deficient and wild-type mice fed a methionine-choline-deficient (MCD) diet; (c) peroxisome proliferation-activator receptor α (PPARα)-deficient mice fed an MCD diet and treated with antagomir-21 or antagomir control. We assessed features of NASH and determined liver microRNA-21 levels and cell localisation. MicroRNA-21 levels were also quantified in the liver of patients with NASH, bland steatosis or normal liver and localisation was determined. Results Inhibiting or suppressing liver microRNA-21 expression reduced liver cell injury, inflammation and fibrogenesis without affecting liver lipid accumulation in Ldlr−/− fed a high-fat diet and in wild-type mice fed an MCD diet. Liver microRNA-21 was overexpressed, primarily in biliary and inflammatory cells, in mouse models as well as in patients with NASH, but not in patients with bland steatosis. PPARα, a known microRNA-21 target, implicated in NASH, was decreased in the liver of mice with NASH and restored following microRNA-21 inhibition or suppression. The effect of antagomir-21 was lost in PPARα-deficient mice. Conclusions MicroRNA-21 inhibition or suppression decreases liver injury, inflammation and fibrosis, by restoring PPARα expression. Antagomir-21 might be a future therapeutic strategy for NASH. PMID:26338827

  10. Targeted inhibition of αvβ3 integrin with an RNA aptamer impairs endothelial cell growth and survival

    International Nuclear Information System (INIS)

    Mi Jing; Zhang Xiuwu; Giangrande, Paloma H.; McNamara, James O.; Nimjee, Shahid M.; Sarraf-Yazdi, Shiva; Sullenger, Bruce A.; Clary, Bryan M.

    2005-01-01

    αvβ3 integrin is a crucial factor involved in a variety of physiological processes, such as cell growth and migration, tumor invasion and metastasis, angiogenesis, and wound healing. αvβ3 integrin exerts its effect by regulating endothelial cell (EC) migration, proliferation, and survival. Inhibiting the function of αvβ3 integrin, therefore, represents a potential anti-cancer, anti-thrombotic, and anti-inflammatory strategy. In this study, we tested an RNA aptamer, Apt-αvβ3 that binds recombinant αvβ3 integrin, for its ability to bind endogenous αvβ3 integrin on the surface of cells in culture and to subsequently affect cellular response. Our data illustrate that Apt-αvβ3 binds αvβ3 integrin expressed on the surface of live HUVECs. This interaction significantly decreases both basal and PDGF-induced cell proliferation as well as inhibition of cell adhesion. Apt-αvβ3 can also reduce PDGF-stimulated tube formation and increase HUVEC apoptosis through inhibition of FAK phosphorylation pathway. Our results demonstrate that by binding to its target, Apt-αvβ3 can efficiently inhibit human EC proliferation and survival, resulting in reduced angiogenesis. It predicts that Apt-αvβ3 could become useful in both tumor imaging and the treatment of tumor growth, atherosclerosis, thrombosis, and inflammation

  11. C/EBPα Short-Activating RNA Suppresses Metastasis of Hepatocellular Carcinoma through Inhibiting EGFR/β-Catenin Signaling Mediated EMT.

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    Hongbo Huan

    Full Text Available Hepatocellular carcinoma is associated with high mortality, and tumor metastasis is an important reason for poor prognosis. However, metastasis has not been effectively prevented in clinical therapy and the mechanisms underlying metastasis have not been fully characterized. CCAAT/enhancer-binding protein-α (C/EBPα is a transcriptional regulator with an essential role in tumor metastasis. We used short-activating RNAs (saRNA to enhance expression of C/EBPα. Intravenous injection of C/EBPα-saRNA in a nude mouse liver orthotopic xenograft tumor model inhibited intrahepatic and distant metastasis. C/EBPα-saRNA-treated mice showed increased serum levels of albumin and decreased alanine aminotransferase (ALT, glutamic-oxalacetic transaminase (AST, indicating a role of C/EBPα in improving liver function. Migration and invasion were inhibited in hepatoma cell lines transfected with C/EBPα-saRNA. We also observed an inhibition of epithelial-mesenchymal transition (EMT and suppression of epidermal growth factor receptor (EGFR, EGFR phosphorylation, and β-catenin in C/EBPa-saRNA-transfected cells. Our results suggested that C/EBPα-saRNA successfully inhibited HCC metastasis by inhibiting EGFR/β-catenin signaling pathway mediated EMT in vitro and in vivo.

  12. Phosphate-methylated DNA aimed at HIV-1 RNA loops and integrated DNA inhibits viral infectivity

    NARCIS (Netherlands)

    Buck, H. M.; Koole, L. H.; van Genderen, M. H.; Smit, L.; Geelen, J. L.; Jurriaans, S.; Goudsmit, J.

    1990-01-01

    Phosphate-methylated DNA hybridizes strongly and specifically to natural DNA and RNA. Hybridization to single-stranded and double-stranded DNA leads to site-selective blocking of replication and transcription. Phosphate-methylated DNA was used to interrupt the life cycle of the human

  13. Rational design of avian metapneumovirus live attenuated vaccines by inhibiting viral messenger RNA cap methyltransferase

    Science.gov (United States)

    Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis, is a non-segmented negative-sense RNA virus belonging to the family of Paramyxoviridae, the subfamily Pneumovirinae, and the genus Metapneumovirus. aMPV is the causative agent of respiratory tract infection and ...

  14. MIF inhibition interferes with the inflammatory and T cell-stimulatory capacity of NOD macrophages and delays autoimmune diabetes onset.

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    Hannelie Korf

    Full Text Available Macrophages contribute in the initiation and progression of insulitis during type 1 diabetes (T1D. However, the mechanisms governing their recruitment into the islets as well as the manner of retention and activation are incompletely understood. Here, we investigated a role for macrophage migration inhibitory factor (MIF and its transmembrane receptor, CD74, in the progression of T1D. Our data indicated elevated MIF concentrations especially in long-standing T1D patients and mice. Additionally, NOD mice featured increased MIF gene expression and CD74+ leukocyte frequencies in the pancreas. We identified F4/80+ macrophages as the main immune cells in the pancreas expressing CD74 and showed that MIF antagonism of NOD macrophages prevented their activation-induced cytokine production. The physiological importance was highlighted by the fact that inhibition of MIF delayed the onset of autoimmune diabetes in two different diabetogenic T cell transfer models. Mechanistically, macrophages pre-conditioned with the MIF inhibitor featured a refractory capacity to trigger T cell activation by keeping them in a naïve state. This study underlines a possible role for MIF/CD74 signaling pathways in promoting macrophage-mediated inflammation in T1D. As therapies directed at the MIF/CD74 pathway are in clinical development, new opportunities may be proposed for arresting T1D progression.

  15. APOBEC3G inhibits HIV-1 RNA elongation by inactivating the viral trans-activation response element.

    Science.gov (United States)

    Nowarski, Roni; Prabhu, Ponnandy; Kenig, Edan; Smith, Yoav; Britan-Rosich, Elena; Kotler, Moshe

    2014-07-29

    Deamination of cytidine residues in viral DNA is a major mechanism by which APOBEC3G (A3G) inhibits vif-deficient human immunodeficiency virus type 1 (HIV-1) replication. dC-to-dU transition following RNase-H activity leads to viral cDNA degradation, production of non-functional proteins, formation of undesired stop codons and decreased viral protein synthesis. Here, we demonstrate that A3G provides an additional layer of defense against HIV-1 infection dependent on inhibition of proviral transcription. HIV-1 transcription elongation is regulated by the trans-activation response (TAR) element, a short stem-loop RNA structure required for elongation factors binding. Vif-deficient HIV-1-infected cells accumulate short viral transcripts and produce lower amounts of full-length HIV-1 transcripts due to A3G deamination of the TAR apical loop cytidine, highlighting the requirement for TAR loop integrity in HIV-1 transcription. We further show that free single-stranded DNA (ssDNA) termini are not essential for A3G activity and a gap of CCC motif blocked with juxtaposed DNA or RNA on either or 3'+5' ends is sufficient for A3G deamination. These results identify A3G as an efficient mutator and that deamination of (-)SSDNA results in an early block of HIV-1 transcription. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Identification of a novel cytochrome P450 CYP321B1 gene from tobacco cutworm (Spodoptera litura) and RNA interference to evaluate its role in commonly used insecticides.

    Science.gov (United States)

    Wang, Rui-Long; Zhu-Salzman, Keyan; Baerson, Scott R; Xin, Xiao-Wei; Li, Jun; Su, Yi-Juan; Zeng, Ren-Sen

    2017-04-01

    Insect cytochrome P450 monooxygenases (CYPs or P450s) play an important role in detoxifying insecticides leading to resistance in insect populations. A polyphagous pest, Spodoptera litura, has developed resistance to a wide range of insecticides. In the present study, a novel P450 gene, CYP321B1, was cloned from S. litura. The function of CYP321B1 was assessed using RNA interference (RNAi) and monitoring resistance levels for three commonly used insecticides, including chlorpyrifos, β-cypermethrin and methomyl. The full-length complementary DNA sequence of CYP321B1 is 1814 bp long with an open reading frame of 1 488 bp encoding 495 amino acid residues. Quantitative reverse-transcriptase polymerase chain reaction analyses during larval and pupal development indicated that CYP321B1 expression was highest in the midgut of fifth-instar larvae, followed by fat body and cuticle. The expression of CYP321B1 in the midgut was up-regulated by chlorpyrifos, β-cypermethrin and methomyl with both lethal concentration at 15% (LC 15 ) (50, 100 and 150 μg/mL, respectively) and 50%(LC 50 ) dosages (100, 200 and 300 μg/mL, respectively). Addition of piperonyl butoxide (PBO) significantly increased the toxicity of chlorpyrifos, β-cypermethrin and methomyl to S. litura, suggesting a marked synergism of the three insecticides with PBO and P450-mediated detoxification. RNAi-mediated silencing of CYP321B1 further increased mortality by 25.6% and 38.9% when the fifth-instar larvae were exposed to chlorpyrifos and β-cypermethrin, respectively, at the LC 50 dose levels. The results demonstrate that CYP321B1 might play an important role in chlorpyrifos and β-cypermethrin detoxification in S. litura. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  17. Small interference RNA profiling reveals the essential role of human membrane trafficking genes in mediating the infectious entry of dengue virus

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    Chu Justin

    2010-02-01

    Full Text Available Abstract Background Dengue virus (DENV is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined. Results In this study, we have used a targeted small interfering RNA (siRNA library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study. Conclusions Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti

  18. Down-regulation of long non-coding RNA TUG1 inhibits osteosarcoma cell proliferation and promotes apoptosis.

    Science.gov (United States)

    Zhang, Qiang; Geng, Pei-Liang; Yin, Pei; Wang, Xiao-Lin; Jia, Jin-Peng; Yao, Jie

    2013-01-01

    To investigate the expression level of TUG1 and one of its transcript variants (n377360) in osteosarcoma cells and assess the role of TUG1 in proliferation and apoptosis in the U2OS cell line. TUG1 and n377360 expression levels in patients with osteosarcomas and the U2OS human osteosarcoma cell line were evaluated using real-time quantitative PCR. U2OS cells were transected with TUG1 and n377360 siRNA or non-targeting siRNA. MTS was performed to assess the cell proliferation and flow cytometry was applied to analyze apoptosis. We found significantly higher TUG1 and n377360 expression levels in osteosarcoma tissues compared with matched non-tumorous tissues. In line with this, suppression of TUG1 and n377360 expression by siRNA significantly impaired the cell proliferation potential of osteosarcoma cells. Furthermore, inhibition of TUG1 expression significantly promoted osteosarcoma cell apoptosis. The overexpression of TUG1 and n377360 in osteosarcoma specimens and the functional role of TUG1 and n377360 regarding cell proliferation and apoptosis in an osteosarcoma cell line provided evidence that the use of TUG1 or n377360 may be a viable but an as yet unexplored therapeutic strategy in tumors that over express these factors.

  19. Inhibition of MMP-2 Expression with siRNA Increases Baseline Cardiomyocyte Contractility and Protects against Simulated Ischemic Reperfusion Injury

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    Han-Bin Lin

    2014-01-01

    Full Text Available Matrix metalloproteinases (MMPs significantly contribute to ischemia reperfusion (I/R injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2 in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

  20. MicroRNA-141 inhibits migration of gastric cancer by targeting zinc finger E-box-binding homeobox 2.

    Science.gov (United States)

    Du, Ying; Wang, Lingfei; Wu, Honghai; Zhang, Yiyin; Wang, Kan; Wu, Dingting

    2015-09-01

    Human microRNA (miR)-141 is a member of the miR‑200 family, which has been reported to be downregulated in gastric cancer, and involved in the proliferation of gastric cancer cells. However, little is currently known regarding its role in the migration of gastric cancer. The present study investigated the function of miR‑141 in gastric cancer cell migration, and evaluated the contribution of zinc finger E‑box‑binding homeobox 1 and 2 (ZEB1/2) in miR‑141 mediated migration of gastric cancer cells. The expression levels of miR‑141 and its potential ZEB1/2 targets were examined by quantitative polymerase chain reaction (qPCR) and western blotting, respectively. The migration of SGC‑7901 and HGC‑27 gastric cancer cells, which had been transfected with an miRNA precursor, was examined by cell migration and wound healing assays. A luciferase activity assay was used to validate whether ZEB1/2 was a direct target of miR‑141. The results demonstrated that overexpression of miR‑141 markedly inhibited the migration of gastric cancer cells in vitro. Forced overexpression of miR‑141 significantly reduced the luciferase activity of the 3'‑untranslated region of ZEB2 in gastric cancer cells. Furthermore, the mRNA and protein expression levels of ZEB2 were reduced in cells overexpressing miR‑141, whereas the protein expression levels of E‑cadherin were increased. In gastric tumor samples the expression levels of ZEB2 were inversely correlated with the expression of miR‑141. These results suggest that miR‑141 may be involved in the inhibition of gastric cancer cell migration, and that ZEB2 is a target gene of miR-141.

  1. Cytoplasmic translocation of polypyrimidine tract-binding protein and its binding to viral RNA during Japanese encephalitis virus infection inhibits virus replication.

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    Deepika Bhullar

    Full Text Available Japanese encephalitis virus (JEV has a single-stranded, positive-sense RNA genome containing a single open reading frame flanked by the 5'- and 3'-non-coding regions (NCRs. The virus genome replicates via a negative-sense RNA intermediate. The NCRs and their complementary sequences in the negative-sense RNA are the sites for assembly of the RNA replicase complex thereby regulating the RNA synthesis and virus replication. In this study, we show that the 55-kDa polypyrimidine tract-binding protein (PTB interacts in vitro with both the 5'-NCR of the positive-sense genomic RNA--5NCR(+, and its complementary sequence in the negative-sense replication intermediate RNA--3NCR(-. The interaction of viral RNA with PTB was validated in infected cells by JEV RNA co-immunoprecipitation and JEV RNA-PTB colocalization experiments. Interestingly, we observed phosphorylation-coupled translocation of nuclear PTB to cytoplasmic foci that co-localized with JEV RNA early during JEV infection. Our studies employing the PTB silencing and over-expression in cultured cells established an inhibitory role of PTB in JEV replication. Using RNA-protein binding assay we show that PTB competitively inhibits association of JEV 3NCR(- RNA with viral RNA-dependent RNA polymerase (NS5 protein, an event required for the synthesis of the plus-sense genomic RNA. cAMP is known to promote the Protein kinase A (PKA-mediated PTB phosphorylation. We show that cells treated with a cAMP analogue had an enhanced level of phosphorylated PTB in the cytoplasm and a significantly suppressed JEV replication. Data presented here show a novel, cAMP-induced, PTB-mediated, innate host response that could effectively suppress JEV replication in mammalian cells.

  2. MicroRNA-202 inhibits tumor progression by targeting LAMA1 in esophageal squamous cell carcinoma

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    Meng, Xiangrui, E-mail: xiangruimengzz@163.com [Department of Oncology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou 450000, Henan Province (China); Chen, Xiaoqi [Department of Digestion and Oncology, The First Affiliated Hospital of Henan Uninversity of TCM, 19 Renmin Road, Zhengzhou 450000, Henan Province (China); Lu, Peng [Department of Gastrointestinal Surgery, The People' s Hospital of Zhengzhou, 33 Huanghe Road, Zhengzhou 450000, Henan Province (China); Ma, Wang; Yue, Dongli; Song, Lijie; Fan, Qingxia [Department of Oncology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou 450000, Henan Province (China)

    2016-05-13

    Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies in the gastrointestinal tract. Emerging studies have indicated that microRNAs (miRNAs) are strongly implicated in the development and progression of ESCC. Here, we focused on the function and the underlying molecular mechanism of miR-202 in ESCC. The results showed that miR-202 was significantly down-regulated in ESCC tissues and cell lines. Overexpression of miR-202 in ECa-109 and KYSE-510 cells markedly suppressed cell proliferation and cell migration, and induced cell apoptosis. Furthermore, laminin α1 (LAMA1) expression was frequently positive in ESCC tissues and inversely correlated with miR-202 expression. Then we demonstrated that miR-202 targeted 3'-untranslated region (UTR) of LAMA1 and inhibited its protein expression. Additionally, LAMA1 overexpression rescued the proliferation inhibition and cell apoptosis elevation induced by miR-202. MiR-202 also inhibited the protein expression of p-FAK and p-Akt, which were all reversed by LAMA1 overexpression. Taken together, these findings suggest that miR-202 may function as a novel tumor suppressor in ESCC by repressing cell proliferation and migration, and its biological effects may attribute the inhibition of LAMA1-mediated FAK-PI3K-Akt signaling. - Highlights: • Expression of miR-202 was decreased in ESCC tissues and cell lines. • MiR-202 overexpression inhibited ESCC cell growth and induced apoptosis. • MiR-202 directly targeted LAMA1 in ESCC. • The LAMA1-FAK-PI3K signaling mediated the suppressive role of miR-202.

  3. Melatonin inhibits proliferation and invasion via repression of miRNA-155 in glioma cells.

    Science.gov (United States)

    Gu, Junyi; Lu, Zhongsheng; Ji, Chenghong; Chen, Yuchao; Liu, Yuzhao; Lei, Zhe; Wang, Longqiang; Zhang, Hong-Tao; Li, Xiangdong

    2017-09-01

    Melatonin, an indolamine mostly synthesized in the pineal gland, exerts the anti-cancer effect by various mechanisms in glioma cells. Our previous study showed that miR-155 promoted glioma cell proliferation and invasion. However, the question of whether melatonin may inhibit glioma by regulating miRNAs has not yet been addressed. In this study, we found that melatonin (100μM, 1μM and 1nM) significantly inhibited the expression of miR-155 in human glioma cell lines U87, U373 and U251. Especially, the lowest expression of miR-155 was detected in 1μM melatonin-treated glioma cells. Melatonin (1μM) inhibits cell proliferation of U87 by promoting cell apoptosis. Nevertheless, melatonin had no effect on cell cycle distribution of U87 cells. Moreover, U87 cells treated with 1μM melatonin presented significantly lower migration and invasion ability when compared with control cells. Importantly, melatonin inhibited c-MYB expression, and c-MYB knockdown reduced miR-155 expression and migration and invasion in U87 cells. Taken together, for the first time, our findings show that melatonin inhibits miR-155 expression and thereby represses glioma cell proliferation, migration and invasion, and suggest that melatonin may downregulate the expression of miR-155 via repression of c-MYB. This will provide a theoretical basis for revealing the anti-glioma mechanisms of melatonin. Copyright © 2017. Published by Elsevier Masson SAS.

  4. Vanillin Suppresses Cell Motility by Inhibiting STAT3-Mediated HIF-1α mRNA Expression in Malignant Melanoma Cells.

    Science.gov (United States)

    Park, Eun-Ji; Lee, Yoon-Mi; Oh, Taek-In; Kim, Byeong Mo; Lim, Beong-Ou; Lim, Ji-Hong

    2017-03-01

    Recent studies have shown that vanillin has anti-cancer, anti-mutagenic, and anti-metastatic activity; however, the precise molecular mechanism whereby vanillin inhibits metastasis and cancer progression is not fully elucidated. In this study, we examined whether vanillin has anti-cancer and anti-metastatic activities via inhibition of hypoxia-inducible factor-1α (HIF-1α) in A2058 and A375 human malignant melanoma cells. Immunoblotting and quantitative real time (RT)-PCR analysis revealed that vanillin down-regulates HIF-1α protein accumulation and the transcripts of HIF-1α target genes related to cancer metastasis including fibronectin 1 ( FN1 ), lysyl oxidase-like 2 ( LOXL2 ), and urokinase plasminogen activator receptor ( uPAR ). It was also found that vanillin significantly suppresses HIF-1α mRNA expression and de novo HIF-1α protein synthesis. To understand the suppressive mechanism of vanillin on HIF-1α expression, chromatin immunoprecipitation was performed. Consequently, it was found that vanillin causes inhibition of promoter occupancy by signal transducer and activator of transcription 3 (STAT3), but not nuclear factor-κB (NF-κB), on HIF1A . Furthermore, an in vitro migration assay revealed that the motility of melanoma cells stimulated by hypoxia was attenuated by vanillin treatment. In conclusion, we demonstrate that vanillin might be a potential anti-metastatic agent that suppresses metastatic gene expression and migration activity under hypoxia via the STAT3-HIF-1α signaling pathway.

  5. Inhibition of host protein synthesis by Sindbis virus: correlation with viral RNA replication and release of nuclear proteins to the cytoplasm.

    Science.gov (United States)

    Sanz, Miguel A; García-Moreno, Manuel; Carrasco, Luis

    2015-04-01

    Infection of mammalian cells by Sindbis virus (SINV) profoundly blocks cellular mRNA translation. Experimental evidence points to viral non-structural proteins (nsPs), in particular nsP2, as the mediator of this inhibition. However, individual expression of nsP1, nsP2, nsP3 or nsP1-4 does not block cellular protein synthesis in BHK cells. Trans-complementation of a defective SINV replicon lacking most of the coding region for nsPs by the co-expression of nsP1-4 propitiates viral RNA replication at low levels, and inhibition of cellular translation is not observed. Exit of nuclear proteins including T-cell intracellular antigen and polypyrimidine tract-binding protein is clearly detected in SINV-infected cells, but not upon the expression of nsPs, even when the defective replicon was complemented. Analysis of a SINV variant with a point mutation in nsP2, exhibiting defects in the shut-off of host protein synthesis, indicates that both viral RNA replication and the release of nuclear proteins to the cytoplasm are greatly inhibited. Furthermore, nucleoside analogues that inhibit cellular and viral RNA synthesis impede the blockade of host mRNA translation, in addition to the release of nuclear proteins. Prevention of the shut-off of host mRNA translation by nucleoside analogues is not due to the inhi