Name: identification of circular rnas using rna sequencing
Uploaded: 2019-11-14T11:00:00
Description: Watch this Scientific Journal Video about Identification of Circular RNAs using RNA Sequencing at JoVE.com

Estamos gratos ao Banner Sun Health Research Institute Brain and Body Donation Program (BBDP) de Sun City, Arizona para o fornecimento de tecidos cerebrais humanos. O BBDP tem sido apoiado pelo Instituto Nacional de Distúrbios Neurológicos e Acidente Vascular Cerebral (U24 NS072026 National Brain and Tissue Resource for Parkinson's Disease and Related Disorders), o National Institute on Aging (P30AG19610 Arizona Alzheimer's Disease Core Center), o Arizona Department of Health Services (contrato 211002, Arizona Alzheimer's Research Center), o Arizona Biomedical Research Commission (contratos 4001, 0011, 05-901 e 1001 para o Arizona Parkinson's Disease Consortium) e michael J. Fox Foundation for Parkinson's Research27. Este estudo também foi apoiado pelo DHS e pelo Estado do Arizona (concessão adhs # ADHS14-052688). Agradecemos também a Andrea Schmitt (Banner Research) e Cynthia Lechuga (TGen) pelo apoio administrativo.

Esta pesquisa tem sido realizada em conformidade com todas as diretrizes institucionais, nacionais e internacionais para o bem-estar humano. Os tecidos cerebrais foram obtidos a partir do Banner Sun Health Research Institute Brain and Body Donation Program em Sun City, AZ. As operações do Programa de Doação de Cérebros e Corpos são aprovadas pelo Western Institutional Review Board (protocolo WIRB #20120821). Todos os sujeitos ou seus representantes legais assinaram o consentimento informado. Bioespécimes comerciai...

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	<li>Salzman, J., Gawad, C., Wang, P. L., Lacayo, N., Brown, P. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+RNAs+are+the+predominant+transcript+isoform+from+hundreds+of+human+genes+in+diverse+cell+types.">Circular RNAs are the predominant transcript isoform from hundreds of human genes in diverse cell types.</a> PloS One. 7 (2), e30733 (2012).</li><li>Jeck, W. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+RNAs+are+abundant,+conserved,+and+associated+with+ALU+repeats.">Circular RNAs are abundant, conserved, and associated with ALU repeats.</a> RNA. 19 (2), 141-157 (2013).</li><li>Memczak, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+RNAs+are+a+large+class+of+animal+RNAs+with+regulatory+potency.">Circular RNAs are a large class of animal RNAs with regulatory potency.</a> Nature. 495 (7441), 333-338 (2013).</li><li>Sanger, H. L., Klotz, G., Riesner, D., Gross, H. J., Kleinschmidt, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viroids+are+single-stranded+covalently+closed+circular+RNA+molecules+existing+as+highly+base-paired+rod-like+structures.">Viroids are single-stranded covalently closed circular RNA molecules existing as highly base-paired rod-like structures.</a> Proceedings of the National Academy of Sciences of the United States of America. 73 (11), 3852-3856 (1976).</li><li>Nigro, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scrambled+exons.">Scrambled exons.</a> Cell. 64 (3), 607-613 (1991).</li><li>Salzman, J., Chen, R. E., Olsen, M. N., Wang, P. L., Brown, P. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-type+specific+features+of+circular+RNA+expression.">Cell-type specific features of circular RNA expression.</a> PLoS Genetics. 9 (9), e1003777 (2013).</li><li>Du, W. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Foxo3+circular+RNA+promotes+cardiac+senescence+by+modulating+multiple+factors+associated+with+stress+and+senescence+responses.">Foxo3 circular RNA promotes cardiac senescence by modulating multiple factors associated with stress and senescence responses.</a> European Heart Journal. 38 (18), 1402-1412 (2016).</li><li>Capel, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+transcripts+of+the+testis-determining+gene+Sry+in+adult+mouse+testis.">Circular transcripts of the testis-determining gene Sry in adult mouse testis.</a> Cell. 73 (5), 1019-1030 (1993).</li><li>Hansen, T. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miRNA-dependent+gene+silencing+involving+Ago2-mediated+cleavage+of+a+circular+antisense+RNA.">miRNA-dependent gene silencing involving Ago2-mediated cleavage of a circular antisense RNA.</a> The EMBO Journal. 30 (21), 4414-4422 (2011).</li><li>Hansen, T. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+RNA+circles+function+as+efficient+microRNA+sponges.">Natural RNA circles function as efficient microRNA sponges.</a> Nature. 495 (7441), 384-388 (2013).</li><li>Li, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exon-intron+circular+RNAs+regulate+transcription+in+the+nucleus.">Exon-intron circular RNAs regulate transcription in the nucleus.</a> Nature Structural &amp; Molecular Biology. 22 (3), 256-264 (2015).</li><li>Tan, W. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+landscape+of+circular+RNA+expression+in+the+human+heart.">A landscape of circular RNA expression in the human heart.</a> Cardiovascular Research. 113 (3), 298-309 (2016).</li><li>Zhong, Z., Lv, M., Chen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Screening+differential+circular+RNA+expression+profiles+reveals+the+regulatory+role+of+circTCF25-miR-103a-3p/miR-107-CDK6+pathway+in+bladder+carcinoma.">Screening differential circular RNA expression profiles reveals the regulatory role of circTCF25-miR-103a-3p/miR-107-CDK6 pathway in bladder carcinoma.</a> Scientific Reports. 6, 30919 (2016).</li><li>Gao, Y., Wang, J., Zhao, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CIRI:+an+efficient+and+unbiased+algorithm+for+de+novo+circular+RNA+identification.">CIRI: an efficient and unbiased algorithm for de novo circular RNA identification.</a> Genome Biology. 16, 4-014-0571-0573 (2015).</li><li>Wang, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MapSplice:+accurate+mapping+of+RNA-seq+reads+for+splice+junction+discovery.">MapSplice: accurate mapping of RNA-seq reads for splice junction discovery.</a> Nucleic Acids Research. 38 (18), e178 (2010).</li><li>Szabo, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Statistically+based+splicing+detection+reveals+neural+enrichment+and+tissue-specific+induction+of+circular+RNA+during+human+fetal+development.">Statistically based splicing detection reveals neural enrichment and tissue-specific induction of circular RNA during human fetal development.</a> Genome Biology. 16, 126-015-0690-0695 (2015).</li><li>Cheng, J., Metge, F., Dieterich, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+identification+and+quantification+of+circular+RNAs+from+sequencing+data.">Specific identification and quantification of circular RNAs from sequencing data.</a> Bioinformatics. 32 (7), 1094-1096 (2016).</li><li>Zhang, X. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complementary+sequence-mediated+exon+circularization.">Complementary sequence-mediated exon circularization.</a> Cell. 159 (1), 134-147 (2014).</li><li>Rybak-Wolf, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+RNAs+in+the+mammalian+brain+are+highly+abundant,+conserved,+and+dynamically+expressed.">Circular RNAs in the mammalian brain are highly abundant, conserved, and dynamically expressed.</a> Molecular Cell. 58 (5), 870-885 (2015).</li><li>Ji, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expanded+Expression+Landscape+and+Prioritization+of+Circular+RNAs+in+Mammals.">Expanded Expression Landscape and Prioritization of Circular RNAs in Mammals.</a> Cell Reports. 26 (12), 3444-3460 (2019).</li><li>Hansen, T. B., Ven&#248;, M. T., Damgaard, C. K., Kjems, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+circular+RNA+prediction+tools.">Comparison of circular RNA prediction tools.</a> Nucleic Acids Research. 44 (6), e58 (2016).</li><li>Zeng, X., Lin, W., Guo, M., Zou, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comprehensive+overview+and+evaluation+of+circular+RNA+detection+tools.">A comprehensive overview and evaluation of circular RNA detection tools.</a> PLoS Comput Biol. 13 (6), e1005420 (2017).</li><li>Sekar, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ACValidator:+a+novel+assembly-based+approach+for+in+silico+validation+of+circular+RNAs.">ACValidator: a novel assembly-based approach for in silico validation of circular RNAs.</a> bioRxiv. , (2019).</li><li>Westholm, J. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-wide+analysis+of+drosophila+circular+RNAs+reveals+their+structural+and+sequence+properties+and+age-dependent+neural+accumulation.">Genome-wide analysis of drosophila circular RNAs reveals their structural and sequence properties and age-dependent neural accumulation.</a> Cell Reports. 9 (5), 1966-1980 (2014).</li><li>Szabo, L., Salzman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+circular+RNAs:+bioinformatic+and+experimental+challenges.">Detecting circular RNAs: bioinformatic and experimental challenges.</a> Nature Reviews Genetics. 17 (11), 679-692 (2016).</li><li>Zheng, Y., Ji, P., Chen, S., Hou, L., Zhao, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reconstruction+of+full-length+circular+RNAs+enables+isoform-level+quantification.">Reconstruction of full-length circular RNAs enables isoform-level quantification.</a> Genome Medicine. 11 (1), 2 (2019).</li><li>Beach, T. 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Neste estudo, dois kits de preparação de bibliotecas comercialmente disponíveis, opções de pré-tratamento e quantidades de RNA de entrada foram testados para otimizar um protocolo de enriquecimento circRNA para a construção de bibliotecas de sequenciamento circRNA. Com base nas avaliações deste estudo, uma série de aspectos-chave e medidas críticas na criação de bibliotecas de sequenciamento circRNA são aparentes. Nossa avaliação confirma a utilidade do pré-tratamento RNase R, como refletido pelo aument...

RNAs circulares (CircRNAs) são RNAs endógenos e não codificadores que ganharam atenção dada a sua expressão generalizada no transcriptoma eucariótico1,2,3. Eles são formados quando exons back-splice uns aos outros e, portanto, foram inicialmente considerados como estandecendo artefatos4,5. No entanto, estudos recentes demonstraram que circRNAs exibem espécies, tecidos e expressão específica em estágio de desenvolvimento3,6 e são conservadas evolutivamente2,3. Além disso, eles estão envolvidos na mediação de interações proteína-proteína7, micro-RNA (miRNA) ligação3,8,9,10, e regulação da transcrição do gene parental11.
No sequenciamento clássico de RNA (RNA-seq), os circRNAs podem estar completamente perdidos durante a construção da biblioteca como resultado da seleção poli-A para mRNAs ou podem ser difíceis de isolar, dada a sua baixa abundância. No entanto, estudos recentes de caracterização circRNA incorporaram uma etapa pré-tratamento usando RNase R, a fim de enriquecer para circRNAs2,12,13. RNase R é um exoribonuclease que digere RNAs lineares, deixando para trás estruturas circulares de RNA. Os protocolos de enriquecimento da CircRNA foram otimizados gerando e comparando dados de dois kits de construção de bibliotecas de transcriptoma inteiras comercialmente disponíveis, com e sem uma etapa pré-tratamento RNase R, e usando quantidades variáveis de entrada total de RNA (1 a 4 μg). O protocolo otimizado foi usado em seguida para avaliar a abundância de circRNAs em cinco regiões cerebrais diferentes (cerebelo [BC], lobo parietal inferior [IP], giro temporal médio [MG], córtex occipital [OC] e giro frontal superior [SF]) e quatro outros tipos de tecido (fígado [LV], pulmão [LU], nólina [LN] e pancreas [PA]). As bibliotecas de RNA-seq foram emparelhadas sequenciadas e os dados foram analisados usando seis algoritmos diferentes de previsão circRNA: find_circ3,CIRI14, Mapsplice15, KNIFE16, DCC17,e CIRCexplorer18. Com base em nossa análise, o maior número de circRNAs únicas foi detectado ao usar um kit de preparação total da biblioteca de RNA com pré-tratamento RNase R e RNA de entrada total de 4 μg. O protocolo otimizado é descrito aqui. Como relatado anteriormente19,20, o maior enriquecimento de circRNAs foi observado no cérebro em comparação com outros tipos de tecido.

<table>
	<tbody>
		<tr>
			<td>1000 &#181;L pipette tips</td>
			<td>Rainin</td>
			<td>GP-L1000F</td>
			<td></td>
		</tr>
		<tr>
			<td>20 &#181;L pipette tips</td>
			<td>Rainin</td>
			<td>SR L 10F</td>
			<td></td>
		</tr>
		<tr>
			<td>200 &#181;L pipette tips</td>
			<td>Rainin</td>
			<td>SR L 200F</td>
			<td></td>
		</tr>
		<tr>
			<td>2200 TapeStation Accessories (foil covers)</td>
			<td>Agilent Technologies</td>
			<td>5067-5154</td>
			<td></td>
		</tr>
		<tr>
			<td>2200 TapeStation Accessories (tips)</td>
			<td>Agilent Technologies</td>
			<td>5067-5153</td>
			<td></td>
		</tr>
		<tr>
			<td>Adhesive Film for Microplates</td>
			<td>VWR</td>
			<td>60941-064</td>
			<td></td>
		</tr>
		<tr>
			<td>AMPure XP Beads 450 mL</td>
			<td>Beckman Coulter</td>
			<td>A63882</td>
			<td>PCR purification</td>
		</tr>
		<tr>
			<td>Eppendorf twin.tec 96-Well PCR Plates</td>
			<td>VWR</td>
			<td>951020401</td>
			<td></td>
		</tr>
		<tr>
			<td>High Sensitivity D1000 reagents</td>
			<td>Agilent Technologies</td>
			<td>5067-5585</td>
			<td></td>
		</tr>
		<tr>
			<td>High Sensitivity D1000 ScreenTape</td>
			<td>Agilent Technologies</td>
			<td>5067-5584</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq 2500 Sequencing System</td>
			<td>Illumina</td>
			<td>SY-401-2501</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq 3000/4000 PE Cluster Kit</td>
			<td>Illumina</td>
			<td>PE-410-1001</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq 3000/4000 SBS Kit (150 cycles)</td>
			<td>Illumina</td>
			<td>FC-410-1002</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq 4000 Sequencing System</td>
			<td>Illumina</td>
			<td>SY-401-4001</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq PE PE Rapid Cluster Kit v2</td>
			<td>Illumina</td>
			<td>PE-402-4002</td>
			<td></td>
		</tr>
		<tr>
			<td>HiSeq Rapid SBS Kit v2 (50 cycle)</td>
			<td>Illumina</td>
			<td>FC-402-4022</td>
			<td></td>
		</tr>
		<tr>
			<td>Kapa Total RNA Kit</td>
			<td>Roche</td>
			<td>KK8400</td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular biology grade ethanol</td>
			<td>Fisher Scientific</td>
			<td>BP28184</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit Assay Tubes</td>
			<td>Supply Center by Thermo Fischer</td>
			<td>Q32856</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit dsDNA High Sense Assay Kit</td>
			<td>Supply Center by Thermo Fischer</td>
			<td>Q32854</td>
			<td></td>
		</tr>
		<tr>
			<td>RNA cleanup and concentrator - 5</td>
			<td>Zymo</td>
			<td>RCC-100</td>
			<td>Contains purification columns, collection tubes</td>
		</tr>
		<tr>
			<td>RNAClean XP beads</td>
			<td>Beckman Coulter Genomics</td>
			<td></td>
			<td>RNA Cleanup beads</td>
		</tr>
		<tr>
			<td>Rnase R</td>
			<td>Lucigen</td>
			<td>RNR07250</td>
			<td></td>
		</tr>
		<tr>
			<td>SuperScript II Reverse Transcriptase 10,000 units</td>
			<td>ThermoFisher (LifeTech)</td>
			<td>18064014</td>
			<td></td>
		</tr>
		<tr>
			<td>TapeStation 2200</td>
			<td>Agilent Technologies</td>
			<td></td>
			<td>Nucleic Acid analyzer</td>
		</tr>
		<tr>
			<td>TElowE</td>
			<td>VWR</td>
			<td>10128-588</td>
			<td></td>
		</tr>
		<tr>
			<td>TruSeq Stranded Total RNA Library Prep Kit</td>
			<td>Illumina</td>
			<td>20020596</td>
			<td>Kit used in section 3</td>
		</tr>
		<tr>
			<td>Two-Compartment Divided Tray</td>
			<td>VWR</td>
			<td>3054-1004</td>
			<td></td>
		</tr>
		<tr>
			<td>UltraPure Water</td>
			<td>Supply Center by Thermo Fischer</td>
			<td>10977-015</td>
			<td></td>
		</tr>
		<tr>
			<td>Universal control RNA</td>
			<td>Agilent</td>
			<td>740000</td>
			<td></td>
		</tr>
	</tbody>
</table>

identification of circular rnas using rna sequencing

RnAs circulares (circRNAs) são uma classe de RNAs não codificadores envolvidos em funções como regulação de microRNA (miRNA), mediação de interações proteína-proteína e regulação da transcrição do gene parental. Na próxima geração clássica de sequenciamento de RNA (RNA-seq), os circRNAs são tipicamente negligenciados como resultado da seleção poli-A durante a construção de bibliotecas de mRNA, ou são encontrados em abundância muito baixa e, portanto, são difíceis de isolar e detectar. Aqui, um protocolo de construção da biblioteca circRNA foi otimizado comparando kits de preparação de bibliotecas, opções de pré-tratamento e vários valores totais de insumos de RNA. Dois kits de preparação de bibliotecas de transcriptoma inteira comercialmente disponíveis, com e sem pré-tratamento RNase R, e usando quantidades variáveis de entrada total de RNA (1 a 4 μg), foram testados. Por último, vários tipos de tecido; incluindo fígado, pulmão, nólina linfática e pâncreas; bem como várias regiões cerebrais; incluindo o cerebelo, o lóbulo parietal inferior, o giro temporal médio, o córtex occipital e o giro frontal superior; foram comparados para avaliar a abundância circRNA em todos os tipos de tecido. A análise dos dados gerados de RNA-seq usando seis ferramentas diferentes de detecção de circRNA (find_circ, CIRI, Mapsplice, KNIFE, DCC e CIRCexplorer) revelou que um kit de preparação total de biblioteca de RNA encalhado com pré-tratamento RNase R e 4 μg de entrada de RNA é o ideal método para identificar o maior número relativo de circRNAs. Consistente com os resultados anteriores, o maior enriquecimento de circRNAs foi observado em tecidos cerebrais em comparação com outros tipos de tecido.

Os dados gerados usando um RNA universal comercialmente disponível do controle (UC) e usando dois jogos da preparação da biblioteca, ambos que incluem uma etapa do ribo-esgotamento em seus protocolos, foram avaliados primeiramente. Usando um fluxo de trabalho analítico (fluxo de trabalho de análise de dados, seção 4), em geral, um maior número de circRNAs foi detectado nos conjuntos de dados truseq em comparação com os Kapa(Figura 1). Embora os percentuais de RNA ribossômico (rRNA...

Watch this Scientific Journal Video about Identification of Circular RNAs using RNA Sequencing at JoVE.com

Identification of Circular RNAs using RNA Sequencing

RNAs circulares (circRNAs) são RNAs não codificadores que podem ter papéis na regulação transcricional e mediar interações entre proteínas. Após a avaliação de diferentes parâmetros para a construção de bibliotecas de sequenciamento circRNA, um protocolo foi compilado utilizando a preparação total da biblioteca de RNA com o pré-tratamento RNase R e é apresentado aqui.

Identificação de RNAs circulares usando sequenciamento de RNA

Circular RNAs (circRNAs) are a class of non-coding RNAs involved in functions including micro-RNA (miRNA) regulation, mediation of protein-protein ...

Este protocolo é o resultado da avaliação de aspectos-chave da preparação da biblioteca circRNA, como tipo de kit, tratamento RNase, quantidades de entrada e seu impacto na detecção de circRNA. Permite a detecção ideal de circRNA e fornece dados sobre parâmetros ajustáveis, dependendo das necessidades do usuário. Identificar circRNAs em diferentes tipos de amostras nos ajudará a entender melhor a distribuição de sua expressão e prepara o cenário para delinear o papel funcional dessas moléculas.Este método pode ser aplicado a qualquer amostra total de RNA. É importante manter amostras de RNA no gelo antes de iniciar o protocolo. Avalie os valores RIN e DV200 no Agilent Bioanalyzer ou TapeStation antes da preparação, e siga os procedimentos apropriados ao trabalhar com RNA.Comece diluindo o RNA total para quatro microgramas em 39 microliters de água sem RNase e pipetting-lo para cima e para baixo para misturar. Em um tubo separado, use 1x RNase R Buffer para diluir o RNase R para uma concentração de trabalho de duas unidades por microliter. Pipeta 39 microliters de RNA total e cinco microliters de 10x RNase R Reaction Buffer em um tubo de reação de 1,5 microliter, e misturar.Adicione seis microliters do RNase diluído R.Em seguida, ajuste a pipeta ao volume total de reação e misture a solução pipetando para cima e para baixo 10 vezes. Coloque o tubo em um banho de água Celsius de 37 graus por 10 minutos, certificando-se de que o volume total de reação esteja imerso no banho de água. Em seguida, coloque o tubo no gelo, e prossiga imediatamente com a limpeza e concentração do RNA.Antes de começar, prepare o RNA Wash Buffer misturando o concentrado com 48 mililitros de 100% etanol, e coloque colunas de purificação em tubos de coleta. Quando estiver pronto, adicione dois volumes de tampão de ligação de RNA à amostra r-tratada r-tratada r e misture bem. Adicione 150 microliters de 100% de etanol à mistura para um total de 300 microliters, transfira todo o volume para a coluna e centrífuga por 30 segundos.Remova o fluxo através e adicione 400 microliters de RNA Prep Buffer diretamente à coluna. Centrifugar por 30 segundos, e descartar o fluxo através. Em seguida, adicione 700 microliters de RNA Wash Buffer à coluna, centrífuga por 30 segundos e descarte o fluxo através.Adicione mais 400 microliters do Wash Buffer, centrífuga por dois minutos e transfira a coluna para um tubo 1.5 mililitro fresco sem RNase. Adicione cuidadosamente 11 microliters de água sem RNase diretamente à coluna, segurando a ponta da pipeta bem acima do filtro da coluna. Deixe a amostra descansar por um minuto à temperatura ambiente e, em seguida, centrifuá-la por um minuto.Certifique-se de que há fluxo através do tubo de 1,5 mililitro, e descarte a coluna. A amostra de RNA purificada pode ser armazenada a menos 80 graus Celsius ou usada imediatamente para a preparação da biblioteca. Transfira 10 microliters do RNA total purificado para um poço limpo em uma placa PCR de 96 poços.Adicione cinco microliters de tampão de ligação rRNA seguido por cinco microliters de rRNA Removal Mix, em seguida, delicadamente pipeta para cima e para baixo para misturar os reagentes. Sele a placa e incuba-a por cinco minutos a 68 graus Celsius em um bloco termocicr pré-programado e pré-aquecido. Após a incubação, deixe a placa ficar em temperatura ambiente por um minuto.Remova o selo da placa e adicione 35 microliters de contas de remoção de rRNA de temperatura ambiente vórtice à amostra. Ajuste a pipeta para 45 microliters, e pipeta para cima e para baixo 10 a 20 vezes para misturar completamente. Deixe o prato ficar em temperatura ambiente por um minuto.Transfira a placa para um suporte magnético e incuba-a lá por um minuto ou até que a solução se limpe. Transfira o supernatante para um novo poço na placa. Em seguida, transfira a placa do suporte magnético para o suporte da placa.As contas de limpeza do Vortex RNA até que estejam bem dispersas e adicionem 99 microliters de contas à amostra. Pipeta para cima e para baixo para misturar, e incubar a placa em temperatura ambiente por 10 minutos. Transfira a placa para o suporte magnético, e deixe-a lá por cinco minutos ou até que a solução se limpe, depois remova e descarte todo o supernatante do poço.Com a placa ainda no suporte magnético, adicione 200 microliters de 80% de etanol recém-preparado ao poço sem interromper as contas. Deixe o etanol no poço por 30 segundos, depois retire e descarte. Adicione 11 microliters de Amortecedor de Elução ao poço, e pipete-o para cima e para baixo para misturar.Incubar a placa em temperatura ambiente por dois minutos, depois transfira-a de volta para o suporte magnético e mantenha-a lá até que a solução se limpe. Transfira 8,5 microliters do supernante para um novo poço na mesma placa, e adicione 8,5 microliters de Elute, Primer, Fragment High Mix para cada poço contendo uma amostra. Pipeta para cima e para baixo 10 vezes para misturar bem, selar a placa e incuba-la por oito minutos em um termociclador pré-aquecido a 94 graus Celsius.Esfrie a amostra a quatro graus Celsius, remova a placa do termociclador e centrífugue-a brevemente. Dois kits de preparação da biblioteca, TruSeq e KAPA, foram avaliados para este protocolo. No geral, foi detectado um maior número de RNAs circulares e menor percentual de RNA ribossômico ao usar o kit TruSeq, de modo que truseq foi selecionado para outros experimentos.A significância do pré-tratamento Rnase R foi avaliada comparando-se os dados gerados a partir de bibliotecas pré-tratadas e não pré-tratadas. Como esperado, um maior número de RNAs circulares foi consistentemente identificado nas bibliotecas pré-tratadas em comparação com as não pré-tratadas. A quantidade de RNA de entrada foi otimizada para detectar uma maior diversidade de RNAs circulares.As bibliotecas foram preparadas utilizando um, dois e quatro microgramas de RNA de entrada, e a maior diversidade de espécies circulares de RNA foi observada ao utilizar quatro microgramas de RNA total. O protocolo otimizado foi utilizado para comparar abundâncias circulares de RNA em cinco regiões cerebrais de quatro doadores saudáveis e para outros tipos de tecidos de seis doadores saudáveis. No geral, observou-se maior abundância de RNase circular no cérebro em comparação com outros tipos de tecido.É importante lembrar de seguir os procedimentos apropriados ao trabalhar com RNA, incluindo usar luvas, limpar completamente o banco e pipetas com lenços rnase ou spray antes de iniciar o protocolo, e manter o RNA no gelo de antemão. Após este procedimento, pode ser realizada validação ortogonal, como o sequenciamento Sanger de junções circRNA identificadas. A descoberta de novas circRNAs e mais evidências de sua presença esculpiram uma nova área de pesquisa para explorar suas funções biológicas.

identification-of-circular-rnas-using-rna-sequencing

Research

JoVE Journal

Genetics

Mapping RNA-RNA Interactions Globally Using Biotinylated Psoralen

Knowing how RNAs interact with themselves and with others is key to understanding RNA based gene regulation in the cell. While examples of RNA-RNA interactions such as microRNA-mRNA interactions have been shown to regulate gene expression, the full extent to which RNA interactions occur in the cell is still unknown. Previous methods to study RNA interactions have primarily focused on subsets of RNAs that are interacting with a particular protein or RNA species. Here, we detail a method named Sequencing of Psoralen crosslinked, Ligated, and Selected Hybrids (SPLASH) that allows genome-wide capture of RNA interactions in vivo in an unbiased manner. SPLASH utilizes in vivo crosslinking, proximity ligation, and high throughput sequencing to identify intramolecular and intermolecular RNA base-pairing partners globally. SPLASH can be applied to different organisms including bacteria, yeast and human cells, as well as diverse cellular conditions to facilitate the understanding of the dynamics of RNA organization under diverse cellular contexts. The entire experimental SPLASH protocol takes about 5 days to complete and the computational workflow takes about 7 days to complete.

Here, we detail the method of Sequencing of Psoralen crosslinked, Ligated, and Selected Hybrids (SPLASH), which enables genome-wide mapping of intramolecular and intermolecular RNA-RNA interactions in vivo. SPLASH can be applied to study RNA interactomes of organisms including yeast, bacteria and humans.

Mapeando as Interações RNA-ARN Globalmente Usando Psoraleno Biotinilado

Knowing how RNAs interact with themselves and with others is key to understanding RNA based gene regulation in the cell. While examples of RNA-RNA ...

Genética

Metabolic Labeling and Profiling of Transfer RNAs Using Macroarrays

Transfer RNAs (tRNA) are abundant short non-coding RNA species that are typically 76 to 90 nucleotides in length. tRNAs are directly responsible for protein synthesis by translating codons in mRNA into amino acid sequences. tRNAs were long considered as house-keeping molecules that lacked regulatory functions. However, a growing body of evidence indicates that cellular tRNA levels fluctuate in correspondence to varying conditions such as cell type, environment, and stress. The fluctuation of tRNA expression directly influences gene translation, favoring or repressing the expression of particular proteins. Ultimately comprehending the dynamic of protein synthesis requires the development of methods able to deliver high-quality tRNA profiles. The method that we present here is named SPOt, which stands for Streamlined Platform for Observing tRNA. SPOt consists of three steps starting with metabolic labeling of cell cultures with radioactive orthophosphate, followed by guanidinium thiocyanate-phenol-chloroform extraction of radioactive total RNAs and finally hybridization on in-house printed macroarrays. tRNA levels are estimated by quantifying the radioactivity intensities at each probe spot. In the protocol presented here we profile tRNAs in Mycobacterium smegmatis mc2155, a nonpathogenic bacterium often used as a model organism to study tuberculosis.

We describe an original transfer RNA analysis platform named SPOt (Streamlined Platform for Observing tRNA). SPOt simultaneously measures cellular levels of all tRNAs in biological samples, in only three steps, and in less than 24 hours.

Etiquetando metabólica e caracterização das RNAs de transferência usando Macroarrays

Transfer RNAs (tRNA) are abundant short non-coding RNA species that are typically 76 to 90 nucleotides in length. tRNAs are directly responsible for ...

Retrospective MicroRNA Sequencing: Complementary DNA Library Preparation Protocol Using Formalin-fixed Paraffin-embedded RNA Specimens

&#8211;Archived, clinically classified formalin-fixed paraffin-embedded (FFPE) tissues can provide nucleic acids for retrospective molecular studies of cancer development. By using non-invasive or pre-malignant lesions from patients who later develop invasive disease, gene expression analyses may help identify early molecular alterations that predispose to cancer risk. It has been well described that nucleic acids recovered from FFPE tissues have undergone severe physical damage and chemical modifications, which make their analysis difficult and generally requires adapted assays. MicroRNAs (miRNAs), however, which represent a small class of RNA molecules spanning only up to ~18&#8211;24 nucleotides, have been shown to withstand long-term storage and have been successfully analyzed in FFPE samples. Here we present a 3&#39; barcoded complementary DNA (cDNA) library preparation protocol specifically optimized for the analysis of small RNAs extracted from archived tissues, which was recently demonstrated to be robust and highly reproducible when using archived clinical specimens stored for up to 35 years. This library preparation is well adapted to the multiplex analysis of compromised/degraded material where RNA samples (up to 18) are ligated with individual 3&#39; barcoded adapters and then pooled together for subsequent enzymatic and biochemical preparations prior to analysis. All purifications are performed by polyacrylamide gel electrophoresis (PAGE), which allows size-specific selections and enrichments of barcoded small RNA species. This cDNA library preparation is well adapted to minute RNA inputs, as a pilot polymerase chain reaction (PCR) allows determination of a specific amplification cycle to produce optimal amounts of material for next-generation sequencing (NGS). This approach was optimized for the use of degraded FFPE RNA from specimens archived for up to 35 years and provides highly reproducible NGS data.

Formalin-fixed paraffin-embedded specimens represent a valuable source of molecular biomarkers of human diseases. Here we present a laboratory-based cDNA library preparation protocol, initially designed with fresh frozen RNA, and optimized for the analysis of archived microRNAs from tissues stored up to 35 years.

Sequenciação de MicroRNA retrospectiva: Biblioteca de DNA complementar preparação protocolo usando amostras de RNA de parafina fixada em formol

&#8211;Archived, clinically classified formalin-fixed paraffin-embedded (FFPE) tissues can provide nucleic acids for retrospective molecular studies of ...

Rare Event Detection Using Error-corrected DNA and RNA Sequencing

Conventional next-generation sequencing techniques (NGS) have allowed for immense genomic characterization for over a decade. Specifically, NGS has been used to analyze the spectrum of clonal mutations in malignancy. Though far more efficient than traditional Sanger methods, NGS struggles with identifying rare clonal and subclonal mutations due to its high error rate of ~0.5&#8211;2.0%. Thus, standard NGS has a limit of detection for mutations that are &#62;0.02 variant allele fraction (VAF). While the clinical significance for mutations this rare in patients without known disease remains unclear, patients treated for leukemia have significantly improved outcomes when residual disease is &#60;0.0001 by flow cytometry. In order to mitigate this artefactual background of NGS, numerous methods have been developed. Here we describe a method for Error-corrected DNA and RNA Sequencing (ECS), which involves tagging individual molecules with both a 16 bp random index for error-correction and an 8 bp patient-specific index for multiplexing. Our method can detect and track clonal mutations at variant allele fractions (VAFs) two orders of magnitude lower than the detection limit of NGS and as rare as 0.0001 VAF.

Next-generation sequencing (NGS) is a powerful tool for genomic characterization that is limited by the high error rate of the platform (~0.5&#8211;2.0%). We describe our methods of error-corrected sequencing that allow us to obviate the NGS error rate and detect mutations at variant allele fractions as rare as 0.0001.

Deteção de evento raro usando o DNA de correção de erro e a sequenciação do ARN

Conventional next-generation sequencing techniques (NGS) have allowed for immense genomic characterization for over a decade. Specifically, NGS has been ...

High-throughput Identification of Gene Regulatory Sequences Using Next-generation Sequencing of Circular Chromosome Conformation Capture (4C-seq)

The identification of regulatory elements for a given target gene poses a significant technical challenge owing to the variability in the positioning and effect sizes of regulatory elements to a target gene. Some progress has been made with the bioinformatic prediction of the existence and function of proximal epigenetic modifications associated with activated gene expression using conserved transcription factor binding sites. Chromatin conformation capture studies have revolutionized our ability to discover physical chromatin contacts between sequences and even within an entire genome. Circular chromatin conformation capture coupled with next-generation sequencing (4C-seq), in particular, is designed to discover all possible physical chromatin interactions for a given sequence of interest (viewpoint), such as a target gene or a regulatory enhancer. Current 4C-seq strategies directly sequence from within the viewpoint but require numerous and diverse viewpoints to be simultaneously sequenced to avoid the technical challenges of uniform base calling (imaging) with next generation sequencing platforms. This volume of experiments may not be practical for many laboratories. Here, we report a modified approach to the 4C-seq protocol that incorporates both an additional restriction enzyme digest and qPCR-based amplification steps that are designed to facilitate a greater capture of diverse sequence reads and mitigate the potential for PCR bias, respectively. Our modified 4C method is amenable to the standard molecular biology lab for assessing chromatin architecture.

High-throughput Identification of Gene Regulatory Sequences Using Next-generation Sequencing of Circular Chromosome Conformation Capture 4C-seq

The identification of physical interactions between genes and regulatory elements is challenging but has been facilitated by chromosome conformation capture methods. This modification to the 4C-seq protocol mitigates PCR bias by minimizing over-amplification of PCR templates and maximizes the mappability of reads by incorporating an addition restriction enzyme digest step.

Identificação do elevado-throughput de sequências de genes regulatórios utilizando a próxima geração sequenciamento de conformação Circular cromossoma capturar (4C-seq)

The identification of regulatory elements for a given target gene poses a significant technical challenge owing to the variability in the positioning and ...

Overexpressing Long Noncoding RNAs Using Gene-activating CRISPR

Long noncoding RNA (lncRNA) biology is a new and exciting field of research, with the number of publications from this field growing exponentially since 2007. These studies have confirmed that lncRNAs are altered in almost all diseases. However, studying the functional roles for lncRNAs in the context of disease remains difficult due to the lack of protein products, tissue-specific expression, low expression levels, complexities in splice forms, and lack of conservation among species. Given the species-specific expression, lncRNA studies are often restricted to human research contexts when studying disease processes. Since lncRNAs function at the molecular level, one way to dissect lncRNA biology is to either remove the lncRNA or overexpress the lncRNA and measure cellular effects. In this article, a written and visualized protocol to overexpress lncRNAs in vitro is presented. As a representative experiment, an lncRNA associated with inflammatory bowel disease, Interferon Gamma Antisense 1 (IFNG-AS1), is shown to be overexpressed in a Jurkat T-cell model. To accomplish this, the activating clustered regularly interspaced short palindromic repeats (CRISPR) technique is used to enable overexpression at the endogenous genomic loci. The activating CRISPR technique targets a set of transcription factors to the transcriptional start site of a gene, enabling a robust overexpression of multiple lncRNA splice forms. This procedure will be broken down into three steps, namely (i) guide RNA (gRNA) design and vector construction, (ii) virus generation and transduction, and (iii) colony screening for overexpression. For this representative experiment, a greater than 20-fold enhancement in IFNG-AS1 in Jurkat T cells was observed.

Traditional cDNA-based overexpression techniques have a limited applicability for the overexpression of long noncoding RNAs due to their multiple splice forms with potential functionality. This review reports a protocol using CRISPR technology to overexpress multiple splice variants of a long noncoding RNA.

Superexpressão de tempo não-codificante RNAs usando CRISPR ativando o Gene

Long noncoding RNA (lncRNA) biology is a new and exciting field of research, with the number of publications from this field growing exponentially since ...

Sequencing of mRNA from Whole Blood using Nanopore Sequencing

Sequencing in remote locations and resource-poor settings presents unique challenges. Nanopore sequencing can be successfully used under such conditions, and was deployed to West Africa during the recent Ebola virus epidemic, highlighting this possibility. In addition to its practical advantages (low cost, ease of equipment transport and use), this technology also provides fundamental advantages over second-generation sequencing approaches, particularly the very long read length, ability to directly sequence RNA, and real-time availability of data. Raw read accuracy is lower than with other sequencing platforms, which represents the main limitation of this technology; however, this can be partially mitigated by the high read depth generated. Here, we present a field-compatible protocol for sequencing of the mRNAs encoding for Niemann-Pick C1, which is the cellular receptor for ebolaviruses. This protocol encompasses extraction of RNA from animal blood samples, followed by RT-PCR for target enrichment, barcoding, library preparation, and the sequencing run itself, and can be easily adapted for use with other DNA or RNA targets.

Nanopore sequencing is a novel technology that allows cost-effective sequencing in remote locations and resource-poor settings. Here, we present a protocol for sequencing of mRNAs from whole blood that is compatible with such conditions.

Sequenciamento de mRNA de sangue total usando sequenciamento de nanoporos

Sequencing in remote locations and resource-poor settings presents unique challenges. Nanopore sequencing can be successfully used under such conditions, ...

Single-cell RNA Sequencing and Analysis of Human Pancreatic Islets

Pancreatic islets comprise of endocrine cells with distinctive hormone expression patterns. The endocrine cells show functional differences in response to normal and pathological conditions. The goal of this protocol is to generate high-quality, large-scale transcriptome data of each endocrine cell type with the use of a droplet-based microfluidic single-cell RNA sequencing technology. Such data can be utilized to build the gene expression profile of each endocrine cell type in normal or specific conditions. The process requires careful handling, accurate measurement, and rigorous quality control. In this protocol, we describe detailed steps for human pancreatic islets dissociation, sequencing, and data analysis. The representative results of about 20,000 human single islet cells demonstrate the successful application of the protocol.

Here, we present a protocol to generate high-quality, large-scale transcriptome data of single cells from isolated human pancreatic islets using a droplet-based microfluidic single-cell RNA sequencing technology.

Sequenciamento de RNA de célula única e análise de ilhotas pancreáticas humanas

Pancreatic islets comprise of endocrine cells with distinctive hormone expression patterns. The endocrine cells show functional differences in response to ...

Identification of Footprints of RNA:Protein Complexes via RNA Immunoprecipitation in Tandem Followed by Sequencing (RIPiT-Seq)

RNA immunoprecipitation in tandem (RIPiT) is a method for enriching RNA footprints of a pair of proteins within an RNA:protein (RNP) complex. RIPiT employs two purification steps. First, immunoprecipitation of a tagged RNP subunit is followed by mild RNase digestion and subsequent non-denaturing affinity elution. A second immunoprecipitation of another RNP subunit allows for enrichment of a defined complex. Following a denaturing elution of RNAs and proteins, the RNA footprints are converted into high-throughput DNA sequencing libraries. Unlike the more popular ultraviolet (UV) crosslinking followed by immunoprecipitation (CLIP) approach to enrich RBP binding sites, RIPiT is UV-crosslinking independent. Hence RIPiT can be applied to numerous proteins present in the RNA interactome and beyond that are essential to RNA regulation but do not directly contact the RNA or UV-crosslink poorly to RNA. The two purification steps in RIPiT provide an additional advantage of identifying binding sites where a protein of interest acts in partnership with another cofactor. The double purification strategy also serves to enhance signal by limiting background. Here, we provide a step-wise procedure to perform RIPiT and to generate high-throughput sequencing libraries from isolated RNA footprints. We also outline RIPiT&#39;s advantages and applications and discuss some of its limitations.

Identification of Footprints of RNA:Protein Complexes via RNA Immunoprecipitation in Tandem Followed by Sequencing RIPiT-Seq

Here, we present a protocol to enrich endogenous RNA binding sites or &#34;footprints&#34;&#160;of RNA:protein (RNP) complexes from mammalian cells. This approach involves two immunoprecipitations of RNP subunits and is therefore dubbed RNA immunoprecipitation in tandem (RIPiT).

Identificação de pegadas de RNA: complexos proteicos via imunoprecipitação de RNA em tandem seguido de sequenciamento (RIPiT-Seq)

RNA immunoprecipitation in tandem (RIPiT) is a method for enriching RNA footprints of a pair of proteins within an RNA:protein (RNP) complex. RIPiT ...

Improving Small RNA-seq: Less Bias and Better Detection of 2'-O-Methyl RNAs

The study of small RNAs (sRNAs) by next-generation sequencing (NGS) is challenged by bias issues during library preparation. Several types of sRNA such as plant microRNAs (miRNAs) carry a 2&#39;-O-methyl (2&#39;-OMe) modification at their 3&#39;&#160;terminal nucleotide. This modification adds another difficulty as it inhibits 3&#39;&#160;adapter ligation. We previously demonstrated that modified versions of the &#39;TruSeq (TS)&#39;&#160;protocol have less bias and an improved detection of 2&#39;-OMe RNAs. Here we describe in detail protocol &#39;TS5&#39;, which showed the best overall performance. TS5 can be followed either using homemade reagents or reagents from the TS kit, with equal performance.

Improving Small RNA-seq: Less Bias and Better Detection of 2&#039;-O-Methyl RNAs

We present a detailed small RNA library reparation protocol with less bias than standard methods and an increased sensitivity for 2&#39;-O-methyl RNAs. This protocol can be followed using homemade reagents to save cost or using kits for convenience.

Melhorando O RNA-Seq pequeno: menos polarização e melhor deteção de 2 '-O-methyl RNAs

The study of small RNAs (sRNAs) by next-generation sequencing (NGS) is challenged by bias issues during library preparation. Several types of sRNA such as ...