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Peng C, Leng M, Gao Y, Feng Q, Miao X. DNA tetrahedral molecular sieve for size-selective fluorescence sensing of miRNA 21 in living cells. Talanta 2024; 276:126218. [PMID: 38759363 DOI: 10.1016/j.talanta.2024.126218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/09/2024] [Accepted: 05/05/2024] [Indexed: 05/19/2024]
Abstract
In situ monitoring of intracellular microRNAs (miRNAs) often encounters the challenges of surrounding complexity, coexistence of precursor miRNAs (pre-miRNAs) and the degradation of biological enzyme in living cells. Here, we designed a novel probe encapsulated DNA tetrahedral molecular sieve (DTMS) to realize the size-selective detection of intracellular miRNA 21 that can avoid the interference of pre-miRNAs. In such strategy, quencher (BHQ-1) labeled probe DNA (S6-BHQ 1) was introduced into the inner cavity of fluorophore (FAM) labeled DNA tetrahedral scaffolds (DTS) to prepare DTMS, making the FAM and BHQ-1 closely proximate, and resulting the sensor in a "signal-off" state. In the presence of miRNA 21, strand displacement reaction happened to form more stable DNA double-stranded structure, accompanied by the release of S6-BHQ 1 from the inner cavity of DTMS, making the sensor in a "signal-on" state. The DTMS based sensing platform can then realized the size-selective detection of miRNA 21 with a detection limit of 3.6 pM. Relying on the mechanical rigidity of DTS and the encapsulation of DNA probe using DTMS, such proposed method achieved preferable reproducibility and storage stability. Moreover, this sensing system exhibited good performance for monitoring the change of intracellular miRNA 21 level during the treatment with miRNA-related drugs, demonstrating great potential for biological studies and accurate disease diagnosis.
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Affiliation(s)
- Chenxu Peng
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, China
| | - Mingyu Leng
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, China
| | - Yongguang Gao
- Department of Radiology, Xuzhou Central Hospital, 199 Jiefang Road, Xuzhou, Jiangsu, China.
| | - Qiumei Feng
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, 221116, China
| | - Xiangmin Miao
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, China.
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2
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Biswas S, Gurdziel K, Meller VH. siRNA that participates in Drosophila dosage compensation is produced by many 1.688X and 359 bp repeats. Genetics 2024; 227:iyae074. [PMID: 38718207 PMCID: PMC11228850 DOI: 10.1093/genetics/iyae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 04/29/2024] [Indexed: 07/09/2024] Open
Abstract
Organisms with differentiated sex chromosomes must accommodate unequal gene dosage in males and females. Male fruit flies increase X-linked gene expression to compensate for hemizygosity of their single X chromosome. Full compensation requires localization of the Male-Specific Lethal (MSL) complex to active genes on the male X, where it modulates chromatin to elevate expression. The mechanisms that identify X chromatin are poorly understood. The euchromatic X is enriched for AT-rich, ∼359 bp satellites termed the 1.688X repeats. Autosomal insertions of 1.688X DNA enable MSL recruitment to nearby genes. Ectopic expression of dsRNA from one of these repeats produces siRNA and partially restores X-localization of MSLs in males with defective X recognition. Surprisingly, expression of double-stranded RNA from three other 1.688X repeats failed to rescue males. We reconstructed dsRNA-expressing transgenes with sequence from two of these repeats and identified phasing of repeat DNA, rather than sequence or orientation, as the factor that determines rescue of males with defective X recognition. Small RNA sequencing revealed that siRNA was produced in flies with a transgene that rescues, but not in those carrying a transgene with the same repeat but different phasing. We demonstrate that pericentromeric X heterochromatin promotes X recognition through a maternal effect, potentially mediated by small RNA from closely related heterochromatic repeats. This suggests that the sources of siRNAs promoting X recognition are highly redundant. We propose that enrichment of satellite repeats on Drosophilid X chromosomes facilitates the rapid evolution of differentiated sex chromosomes by marking the X for compensation.
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Affiliation(s)
- Sudeshna Biswas
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
| | - Katherine Gurdziel
- Department of Pharmacology, Wayne State University, Integrative Bioscience Center (iBio), 6135 Woodward, Detroit, MI 48202, USA
- Institute of Environmental Health Sciences, Wayne State University, Integrative Bioscience Center (iBio), 6135 Woodward, Detroit, MI 48202, USA
| | - Victoria H Meller
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
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3
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Rac M. Synthesis and Regulation of miRNA, Its Role in Oncogenesis, and Its Association with Colorectal Cancer Progression, Diagnosis, and Prognosis. Diagnostics (Basel) 2024; 14:1450. [PMID: 39001340 PMCID: PMC11241650 DOI: 10.3390/diagnostics14131450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/27/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024] Open
Abstract
The dysfunction of several types of regulators, including miRNAs, has recently attracted scientific attention for their role in cancer-associated changes in gene expression. MiRNAs are small RNAs of ~22 nt in length that do not encode protein information but play an important role in post-transcriptional mRNA regulation. Studies have shown that miRNAs are involved in tumour progression, including cell proliferation, cell cycle, apoptosis, and tumour angiogenesis and invasion, and play a complex and important role in the regulation of tumourigenesis. The detection of selected miRNAs may help in the early detection of cancer cells, and monitoring changes in their expression profile may serve as a prognostic factor in the course of the disease or its treatment. MiRNAs may serve as diagnostic and prognostic biomarkers, as well as potential therapeutic targets for colorectal cancer. In recent years, there has been increasing evidence for an epigenetic interaction between DNA methylation and miRNA expression in tumours. This article provides an overview of selected miRNAs, which are more frequently expressed in colorectal cancer cells, suggesting an oncogenic nature.
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Affiliation(s)
- Monika Rac
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Al. Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
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4
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Lee H, Roh SH. Cryo-EM structures of human DICER dicing a pre-miRNA substrate. FEBS J 2024; 291:3072-3079. [PMID: 38151772 DOI: 10.1111/febs.17048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 12/29/2023]
Abstract
Dicer, a multi-domain ribonuclease III (RNase III) protein, is crucial for gene regulation via RNA interference. It processes hairpin-like precursors into microRNAs (miRNAs) and long double-stranded RNAs (dsRNAs) into small interfering RNAs (siRNAs). During the "dicing" process, the miRNA or siRNA substrate is stably anchored and cleaved by Dicer's RNase III domain. Although numerous studies have investigated long dsRNA cleavage by Dicer, the specific mechanism by which human Dicer (hDICER) processes pre-miRNA remains unelucidated. This review introduces the recently revealed hDICER structure bound to pre-miRNA uncovered through cryo-electron microscopy and compares it with previous reports describing Dicer. The domain-wise movements of the helicase and dsRNA-binding domain (dsRBD) and specific residues involved in substrate sequence recognition have been identified. During RNA substrate binding, the hDICER apical domains and dsRBD recognize the pre-miRNA termini and cleavage site, respectively. Residue rearrangements in positively charged pockets within the apical domain influence substrate recognition and cleavage site determination. The specific interactions between dsRBD positively charged residues and nucleotide bases near the cleavage site emphasize the significance of cis-acting elements in the hDICER processing mechanism. These findings provide valuable insights for understanding hDICER-related diseases.
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Affiliation(s)
- Hansol Lee
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Soung-Hun Roh
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
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5
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Maltseva D, Kirillov I, Zhiyanov A, Averinskaya D, Suvorov R, Gubani D, Kudriaeva A, Belogurov A, Tonevitsky A. Incautious design of shRNAs for stable overexpression of miRNAs could result in generation of undesired isomiRs. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195046. [PMID: 38876159 DOI: 10.1016/j.bbagrm.2024.195046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 06/16/2024]
Abstract
shRNA-mediated strategy of miRNA overexpression based on RNA Polymerase (Pol III) expression cassettes is widely used for miRNA functional studies. For some miRNAs, e.g., encoded in the genome as a part of a polycistronic miRNA cluster, it is most likely the only way for their individual stable overexpression. Here we have revealed that expression of miRNAs longer than 19 nt (e.g. 23 nt in length hsa-miR-93-5p) using such approach could be accompanied by undesired predominant generation of 5' end miRNA isoforms (5'-isomiRs). Extra U residues (up to five) added by Pol III at the 3' end of the transcribed shRNA during transcription termination could cause a shift in the Dicer cleavage position of the shRNA. This results in the formation of 5'-isomiRs, which have a significantly altered seed region compared to the initially encoded canonical hsa-miR-93-5p. We demonstrated that the commonly used qPCR method is insensitive to the formation of 5'-isomiRs and cannot be used to confirm miRNA overexpression. However, the predominant expression of 5'-isomiRs without three or four first nucleotides instead of the canonical isoform could be disclosed based on miRNA-Seq analysis. Moreover, mRNA sequencing data showed that the 5'-isomiRs of hsa-miR-93-5p presumably regulate their own mRNA targets. Thus, omitting miRNA-Seq analysis may lead to erroneous conclusions regarding revealed mRNA targets and possible molecular mechanisms in which studied miRNA is involved. Overall, the presented results show that structures of shRNAs for stable overexpression of miRNAs requires careful design to avoid generation of undesired 5'-isomiRs.
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Affiliation(s)
- Diana Maltseva
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Ivan Kirillov
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Anton Zhiyanov
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Daria Averinskaya
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Roman Suvorov
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Daria Gubani
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia
| | - Anna Kudriaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Alexey Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Alexander Tonevitsky
- Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow 101000, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; Art Photonics GmbH, Berlin 12489, Germany.
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6
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Elder JJH, Papadopoulos R, Hayne CK, Stanley RE. The making and breaking of tRNAs by ribonucleases. Trends Genet 2024; 40:511-525. [PMID: 38641471 PMCID: PMC11152995 DOI: 10.1016/j.tig.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/21/2024]
Abstract
Ribonucleases (RNases) play important roles in supporting canonical and non-canonical roles of tRNAs by catalyzing the cleavage of the tRNA phosphodiester backbone. Here, we highlight how recent advances in cryo-electron microscopy (cryo-EM), protein structure prediction, reconstitution experiments, tRNA sequencing, and other studies have revealed new insight into the nucleases that process tRNA. This represents a very diverse group of nucleases that utilize distinct mechanisms to recognize and cleave tRNA during different stages of a tRNA's life cycle including biogenesis, fragmentation, surveillance, and decay. In this review, we provide a synthesis of the structure, mechanism, regulation, and modes of tRNA recognition by tRNA nucleases, along with open questions for future investigation.
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Affiliation(s)
- Jessica J H Elder
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Ry Papadopoulos
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA; Department of Chemistry, University of Chicago, Chicago, IL, USA
| | - Cassandra K Hayne
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.
| | - Robin E Stanley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
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7
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Xu WB, Cao F, Liu P, Yan K, Guo QH. The multifaceted role of RNA-based regulation in plant stress memory. FRONTIERS IN PLANT SCIENCE 2024; 15:1387575. [PMID: 38736453 PMCID: PMC11082352 DOI: 10.3389/fpls.2024.1387575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/15/2024] [Indexed: 05/14/2024]
Abstract
Plants have evolved interconnected regulatory pathways which enable them to respond and adapt to their environments. In plants, stress memory enhances stress tolerance through the molecular retention of prior stressful experiences, fostering rapid and robust responses to subsequent challenges. Mounting evidence suggests a close link between the formation of stress memories and effective future stress responses. However, the mechanism by which environmental stressors trigger stress memory formation is poorly understood. Here, we review the current state of knowledge regarding the RNA-based regulation on stress memory formation in plants and discuss research challenges and future directions. Specifically, we focus on the involvement of microRNAs (miRNAs), small interfering RNAs (siRNAs), long non-coding RNAs (lncRNAs), and alternative splicing (AS) in stress memory formation. miRNAs regulate target genes via post-transcriptional silencing, while siRNAs trigger stress memory formation through RNA-directed DNA methylation (RdDM). lncRNAs guide protein complexes for epigenetic regulation, and AS of pre-mRNAs is crucial to plant stress memory. Unraveling the mechanisms underpinning RNA-mediated stress memory formation not only advances our knowledge of plant biology but also aids in the development of improved stress tolerance in crops, enhancing crop performance and global food security.
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Affiliation(s)
- Wei-Bo Xu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
| | - Fan Cao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
| | - Peng Liu
- Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Kang Yan
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
| | - Qian-Huan Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
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8
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Lv Y, Wang H, Zheng D, Shi M, Bi D, Hu Q, Zhi H, Lou D, Li J, Wei S, Hu Y. Environmental arsenic pollution induced liver oxidative stress injury by regulating miR-155 through inhibition of AUF1. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171237. [PMID: 38423337 DOI: 10.1016/j.scitotenv.2024.171237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/02/2024]
Abstract
Arsenic (As), a common environmental pollutant, has become a hot topic in recent years due to its potentially harmful effects. Liver damage being a central clinical feature of chronic arsenic poisoning. However, the underlying mechanisms remain unclear. We demonstrated that arsenic can lead to oxidative stress in the liver and result in structural and functional liver damage, significantly correlated with the expression of AUF1, Dicer1, and miR-155 in the liver. Interestingly, knockdown AUF1 promoted the up-regulatory effects of arsenic on Dicer1 and miR-155 and the inhibitory effects on SOD1, which exacerbated oxidative damage in rat liver. However, overexpression of AUF1 reversed the up-regulatory effects of arsenic on Dicer1 and miR-155, restored arsenic-induced SOD1 depletion, and attenuated liver oxidative stress injury. Further, we verified the mechanism and targets of miR-155 in regulating SOD1 by knockdown/overexpression of miR-155 and nonsense mutant SOD1 3'UTR experiments. In conclusion, these results powerfully demonstrate that arsenic inhibits AUF1 protein expression, which in turn reduces the inhibitory effect on Dicer1 expression, which promotes miR-155 to act on the SOD1 3'UTR region after high expression, thus inhibiting SOD1 protein expression and enzyme activity, and inducing liver injury. This finding provides a new perspective for the mechanism research and targeted prevention of arsenic poisoning, as well as scientific evidence for formulating strategies to prevent and control environmental arsenic pollution.
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Affiliation(s)
- Ying Lv
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Hongling Wang
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Dan Zheng
- Guiyang Maternity and Child Health Hospital, Guiyang 550003, Guizhou, China
| | - Mingyang Shi
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Dingnian Bi
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Qian Hu
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Haiyan Zhi
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Didong Lou
- Department of Forensic Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, Guizhou, China; Key Laboratory of Traditional Chinese Medicine Toxicology in Forensic Medicine, Guizhou Education Department, Guiyang 550025, Guizhou, China
| | - Jun Li
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Shaofeng Wei
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China
| | - Yong Hu
- Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 561113, Guizhou, China.
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9
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Le CT, Nguyen TD, Nguyen TA. Two-motif model illuminates DICER cleavage preferences. Nucleic Acids Res 2024; 52:1860-1877. [PMID: 38167721 PMCID: PMC10899750 DOI: 10.1093/nar/gkad1186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/25/2023] [Accepted: 12/02/2023] [Indexed: 01/05/2024] Open
Abstract
In humans, DICER is a key regulator of gene expression through its production of miRNAs and siRNAs by processing miRNA precursors (pre-miRNAs), short-hairpin RNAs (shRNAs), and long double-stranded RNAs (dsRNAs). To advance our understanding of this process, we employed high-throughput dicing assays using various shRNA variants and both wild-type and mutant DICER. Our analysis revealed that DICER predominantly cleaves shRNAs at two positions, specifically at 21 (DC21) and 22 (DC22) nucleotides from their 5'-end. Our investigation identified two different motifs, mWCU and YCR, that determine whether DICER cleaves at DC21 or DC22, depending on their locations in shRNAs/pre-miRNAs. These motifs can work together or independently to determine the cleavage sites of DICER. Furthermore, our findings indicate that dsRNA-binding domain (dsRBD) of DICER enhances its cleavage, and mWCU strengthens the interaction between dsRBD and RNA, leading to an even greater enhancement of the cleavage. Conversely, YCR functions independently of dsRBD. Our study proposes a two-motif model that sheds light on the intricate regulatory mechanisms involved in gene expression by elucidating how DICER recognizes its substrates, providing valuable insights into this critical biological process.
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Affiliation(s)
- Cong Truc Le
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Trung Duc Nguyen
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Tuan Anh Nguyen
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
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10
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Chowdhury S, Sais D, Donnelly S, Tran N. The knowns and unknowns of helminth-host miRNA cross-kingdom communication. Trends Parasitol 2024; 40:176-191. [PMID: 38151361 DOI: 10.1016/j.pt.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/29/2023]
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that oversee gene modulation. They are integral to cellular functions and can migrate between species, leading to cross-kingdom gene suppression. Recent breakthroughs in helminth genome studies have sparked curiosity about helminth RNA regulators and their ability to regulate genes across species. Growing data indicate that helminth miRNAs have a significant impact on the host's immune system. Specific miRNAs from helminth parasites can merge with the host's miRNA system, implying that parasites could exploit their host's regulatory machinery and function. This review highlights the role of cross-kingdom helminth-derived miRNAs in the interplay between host and parasite, exploring potential routes for their uptake, processing, and consequences in host interaction.
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Affiliation(s)
- Sumaiya Chowdhury
- The School of Life Sciences, University of Technology, Sydney, Australia; School of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Ultimo, NSW, Australia
| | - Dayna Sais
- School of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Ultimo, NSW, Australia
| | - Sheila Donnelly
- The School of Life Sciences, University of Technology, Sydney, Australia.
| | - Nham Tran
- School of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Ultimo, NSW, Australia.
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11
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Dadhwal G, Samy H, Bouvette J, El-Azzouzi F, Dagenais P, Legault P. Substrate promiscuity of Dicer toward precursors of the let-7 family and their 3'-end modifications. Cell Mol Life Sci 2024; 81:53. [PMID: 38261114 PMCID: PMC10806991 DOI: 10.1007/s00018-023-05090-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/27/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024]
Abstract
The human let-7 miRNA family consists of thirteen members that play critical roles in many biological processes, including development timing and tumor suppression, and their levels are disrupted in several diseases. Dicer is the endoribonuclease responsible for processing the precursor miRNA (pre-miRNA) to yield the mature miRNA, and thereby plays a crucial role in controlling the cellular levels of let-7 miRNAs. It is well established that the sequence and structural features of pre-miRNA hairpins such as the 5'-phosphate, the apical loop, and the 2-nt 3'-overhang are important for the processing activity of Dicer. Exceptionally, nine precursors of the let-7 family (pre-let-7) contain a 1-nt 3'-overhang and get mono-uridylated in vivo, presumably to allow efficient processing by Dicer. Pre-let-7 are also oligo-uridylated in vivo to promote their degradation and likely prevent their efficient processing by Dicer. In this study, we systematically investigated the impact of sequence and structural features of all human let-7 pre-miRNAs, including their 3'-end modifications, on Dicer binding and processing. Through the combination of SHAPE structural probing, in vitro binding and kinetic studies using purified human Dicer, we show that despite structural discrepancies among pre-let-7 RNAs, Dicer exhibits remarkable promiscuity in binding and cleaving these substrates. Moreover, the 1- or 2-nt 3'-overhang, 3'-mono-uridylation, and 3'-oligo-uridylation of pre-let-7 substrates appear to have little effect on Dicer binding and cleavage rates. Thus, this study extends current knowledge regarding the broad substrate specificity of Dicer and provides novel insight regarding the effect of 3'-modifications on binding and cleavage by Dicer.
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Affiliation(s)
- Gunjan Dadhwal
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada
| | - Hebatallah Samy
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada
| | - Jonathan Bouvette
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada
- Molecular Biology Department, Guyot Hall, Princeton University, Princeton, NJ, 08544, USA
| | - Fatima El-Azzouzi
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada
- Biochemistry Department, Wake Forest Biotech Place, 575 Patterson Avenue, Winston-Salem, NC, 27101, USA
| | - Pierre Dagenais
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada
| | - Pascale Legault
- Département de biochimie et médecine moléculaire, Université de Montréal, Downtown Station, Box 6128, Montreal, QC, H3C 3J7, Canada.
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12
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Bofill-De Ros X, Vang Ørom UA. Recent progress in miRNA biogenesis and decay. RNA Biol 2024; 21:1-8. [PMID: 38031325 PMCID: PMC10761092 DOI: 10.1080/15476286.2023.2288741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2023] [Indexed: 12/01/2023] Open
Abstract
MicroRNAs are a class of small regulatory RNAs that mediate regulation of protein synthesis by recognizing sequence elements in mRNAs. MicroRNAs are processed through a series of steps starting from transcription and primary processing in the nucleus to precursor processing and mature function in the cytoplasm. It is also in the cytoplasm where levels of mature microRNAs can be modulated through decay mechanisms. Here, we review the recent progress in the lifetime of a microRNA at all steps required for maintaining their homoeostasis. The increasing knowledge about microRNA regulation upholds great promise as therapeutic targets.
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Affiliation(s)
- Xavier Bofill-De Ros
- RNA Biology and Innovation, Institute of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Ulf Andersson Vang Ørom
- RNA Biology and Innovation, Institute of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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13
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Li Y, Zhang Z, Wang S, Du X, Li Q. miR-423 sponged by lncRNA NORHA inhibits granulosa cell apoptosis. J Anim Sci Biotechnol 2023; 14:154. [PMID: 38053184 DOI: 10.1186/s40104-023-00960-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 11/06/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND Atresia and degeneration, a follicular developmental fate that reduces female fertility and is triggered by granulosa cell (GC) apoptosis, have been induced by dozens of miRNAs. Here, we report a miRNA, miR-423, that inhibits the initiation of follicular atresia (FA), and early apoptosis of GCs. RESULTS We showed that miR-423 was down-regulated during sow FA, and its levels in follicles were negatively correlated with the GC density and the P4/E2 ratio in the follicular fluid in vivo. The in vitro gain-of-function experiments revealed that miR-423 suppresses cell apoptosis, especially early apoptosis in GCs. Mechanically speaking, the miR-423 targets and interacts with the 3'-UTR of the porcine SMAD7 gene, which encodes an apoptosis-inducing factor in GCs, and represses its expression and pro-apoptotic function. Interestingly, FA and the GC apoptosis-related lncRNA NORHA was demonstrated as a ceRNA of miR-423. Additionally, we showed that a single base deletion/insertion in the miR-423 promoter is significantly associated with the number of stillbirths (NSB) trait of sows. CONCLUSION These results demonstrate that miR-423 is a small molecule for inhibiting FA initiation and GC early apoptosis, suggesting that treating with miR-423 may be a novel approach for inhibiting FA initiation and improving female fertility.
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Affiliation(s)
- Yuqi Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhuofan Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Siqi Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xing Du
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qifa Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
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14
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Shang R, Lee S, Senavirathne G, Lai EC. microRNAs in action: biogenesis, function and regulation. Nat Rev Genet 2023; 24:816-833. [PMID: 37380761 PMCID: PMC11087887 DOI: 10.1038/s41576-023-00611-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2023] [Indexed: 06/30/2023]
Abstract
Ever since microRNAs (miRNAs) were first recognized as an extensive gene family >20 years ago, a broad community of researchers was drawn to investigate the universe of small regulatory RNAs. Although core features of miRNA biogenesis and function were revealed early on, recent years continue to uncover fundamental information on the structural and molecular dynamics of core miRNA machinery, how miRNA substrates and targets are selected from the transcriptome, new avenues for multilevel regulation of miRNA biogenesis and mechanisms for miRNA turnover. Many of these latest insights were enabled by recent technological advances, including massively parallel assays, cryogenic electron microscopy, single-molecule imaging and CRISPR-Cas9 screening. Here, we summarize the current understanding of miRNA biogenesis, function and regulation, and outline challenges to address in the future.
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Affiliation(s)
- Renfu Shang
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Seungjae Lee
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Gayan Senavirathne
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA.
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15
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Sala L, Kumar M, Prajapat M, Chandrasekhar S, Cosby RL, La Rocca G, Macfarlan TS, Awasthi P, Chari R, Kruhlak M, Vidigal JA. AGO2 silences mobile transposons in the nucleus of quiescent cells. Nat Struct Mol Biol 2023; 30:1985-1995. [PMID: 37985687 DOI: 10.1038/s41594-023-01151-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/27/2023] [Indexed: 11/22/2023]
Abstract
Argonaute 2 (AGO2) is a cytoplasmic component of the miRNA pathway, with essential roles in development and disease. Yet little is known about its regulation in vivo. Here we show that in quiescent mouse splenocytes, AGO2 localizes almost exclusively to the nucleus. AGO2 subcellular localization is modulated by the Pi3K-AKT-mTOR pathway, a well-established regulator of quiescence. Signaling through this pathway in proliferating cells promotes AGO2 cytoplasmic accumulation, at least in part by stimulating the expression of TNRC6, an essential AGO2 binding partner in the miRNA pathway. In quiescent cells in which mTOR signaling is low, AGO2 accumulates in the nucleus, where it binds to young mobile transposons co-transcriptionally to repress their expression via its catalytic domain. Our data point to an essential but previously unrecognized nuclear role for AGO2 during quiescence as part of a genome-defense system against young mobile elements and provide evidence of RNA interference in the soma of mammals.
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Affiliation(s)
- Laura Sala
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA
| | - Manish Kumar
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA
| | - Mahendra Prajapat
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA
| | - Srividya Chandrasekhar
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA
| | - Rachel L Cosby
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA
- The National Institute for General Medical Sciences, The National Institutes of Health, Bethesda, MD, USA
| | - Gaspare La Rocca
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Todd S Macfarlan
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, MD, USA
| | - Parirokh Awasthi
- Laboratory Animal Sciences Program, Frederick National Lab for Cancer Research, The National Institutes of Health, Frederick, MD, USA
| | - Raj Chari
- Laboratory Animal Sciences Program, Frederick National Lab for Cancer Research, The National Institutes of Health, Frederick, MD, USA
| | - Michael Kruhlak
- CCR Confocal Microscopy Core Facility, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA
| | - Joana A Vidigal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, The National Institutes of Health, Bethesda, MD, USA.
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16
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Weng Q, Wu Q, Zheng Q. New discoveries on how DICER efficiently processes pre-miRNA. MedComm (Beijing) 2023; 4:e430. [PMID: 38034100 PMCID: PMC10685087 DOI: 10.1002/mco2.430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 10/11/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
The latest study identified the "GYM motif" on precursor microRNA (pre-miRNA) for the first time and highlighted its key role in DICER specifically recognizing and efficiently cleaving pre-miRNA to produce miRNA. In addition, the dicing state of DICER efficiently processing pre-miRNA was revealed, which was previously difficult to capture.
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Affiliation(s)
- Qi Weng
- Department of PharmacyQuzhou People's HospitalThe Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhouChina
| | - Qi Wu
- Core FacilityQuzhou People's HospitalThe Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhouChina
| | - Quan Zheng
- Core FacilityQuzhou People's HospitalThe Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhouChina
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17
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Zhang L, Liu J, Hou Y. Classification, function, and advances in tsRNA in non-neoplastic diseases. Cell Death Dis 2023; 14:748. [PMID: 37973899 PMCID: PMC10654580 DOI: 10.1038/s41419-023-06250-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/14/2023] [Accepted: 10/25/2023] [Indexed: 11/19/2023]
Abstract
tRNA-derived small RNAs (tsRNAs) are non-coding small RNAs produced by specific endonucleases following the processing and splicing of precursor or mature tRNAs upon starvation, oxidative stress, hypoxia, and other adverse conditions. tRNAs are classified into two major categories, tRNA fragments (tRFs) and tRNA-derived stress-induced small RNAs (tiRNAs), based on differences in splice sites. With the development of high-throughput sequencing technologies in recent years, tsRNAs have been found to have important biological functions, including inhibition of apoptosis, epigenetic regulation, cell-cell communication, translation, and regulation of gene expression. Additionally, these molecules have been found to be aberrantly expressed in various diseases and to be involved in several pathological processes. In this article, the classification and nomenclature, biological functions, and potential use of tsRNAs as diagnostic biomarkers and therapeutic targets in non-neoplastic diseases are reviewed. Although tsRNA research is at its infancy, their potential in the treatment of non-tumor diseases warrants further investigation.
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Affiliation(s)
- Liou Zhang
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jie Liu
- Translational Research Experiment Department, Science Experiment Center, China Medical University, Shenyang, China.
| | - Yang Hou
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, 110004, China.
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18
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Larivera S, Neumeier J, Meister G. Post-transcriptional gene silencing in a dynamic RNP world. Biol Chem 2023; 404:1051-1067. [PMID: 37739934 DOI: 10.1515/hsz-2023-0203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/04/2023] [Indexed: 09/24/2023]
Abstract
MicroRNA (miRNA)-guided gene silencing is a key regulatory process in various organisms and linked to many human diseases. MiRNAs are processed from precursor molecules and associate with Argonaute proteins to repress the expression of complementary target mRNAs. Excellent work by numerous labs has contributed to a detailed understanding of the mechanisms of miRNA function. However, miRNA effects have mostly been analyzed and viewed as isolated events and their natural environment as part of complex RNA-protein particles (RNPs) is often neglected. RNA binding proteins (RBPs) regulate key enzymes of the miRNA processing machinery and furthermore RBPs or readers of RNA modifications may modulate miRNA activity on mRNAs. Such proteins may function similarly to miRNAs and add their own contributions to the overall expression level of a particular gene. Therefore, post-transcriptional gene regulation might be more the sum of individual regulatory events and should be viewed as part of a dynamic and complex RNP world.
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Affiliation(s)
- Simone Larivera
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, D-93053, Regensburg, Germany
| | - Julia Neumeier
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, D-93053, Regensburg, Germany
| | - Gunter Meister
- Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, D-93053, Regensburg, Germany
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19
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Liao SE, Sudarshan M, Regev O. Deciphering RNA splicing logic with interpretable machine learning. Proc Natl Acad Sci U S A 2023; 120:e2221165120. [PMID: 37796983 PMCID: PMC10576025 DOI: 10.1073/pnas.2221165120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 08/29/2023] [Indexed: 10/07/2023] Open
Abstract
Machine learning methods, particularly neural networks trained on large datasets, are transforming how scientists approach scientific discovery and experimental design. However, current state-of-the-art neural networks are limited by their uninterpretability: Despite their excellent accuracy, they cannot describe how they arrived at their predictions. Here, using an "interpretable-by-design" approach, we present a neural network model that provides insights into RNA splicing, a fundamental process in the transfer of genomic information into functional biochemical products. Although we designed our model to emphasize interpretability, its predictive accuracy is on par with state-of-the-art models. To demonstrate the model's interpretability, we introduce a visualization that, for any given exon, allows us to trace and quantify the entire decision process from input sequence to output splicing prediction. Importantly, the model revealed uncharacterized components of the splicing logic, which we experimentally validated. This study highlights how interpretable machine learning can advance scientific discovery.
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Affiliation(s)
- Susan E. Liao
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York University, New York, NY10012
| | - Mukund Sudarshan
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York University, New York, NY10012
| | - Oded Regev
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York University, New York, NY10012
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20
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Hasiuk M, Dölz M, Marone R, Jeker LT. Leveraging microRNAs for cellular therapy. Immunol Lett 2023; 262:27-35. [PMID: 37660892 DOI: 10.1016/j.imlet.2023.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/16/2023] [Accepted: 08/30/2023] [Indexed: 09/05/2023]
Abstract
Owing to Karl Landsteiner's discovery of blood groups, blood transfusions became safe cellular therapies in the early 1900s. Since then, cellular therapy made great advances from transfusions with unmodified cells to today's commercially available chimeric antigen receptor (CAR) T cells requiring complex manufacturing. Modern cellular therapy products can be improved using basic knowledge of cell biology and molecular genetics. Emerging genome engineering tools are becoming ever more versatile and precise and thus catalyze rapid progress towards programmable therapeutic cells that compute input and respond with defined output. Despite a large body of literature describing important functions of non-coding RNAs including microRNAs (miRNAs), the vast majority of cell engineering efforts focuses on proteins. However, miRNAs form an important layer of posttranscriptional regulation of gene expression. Here, we highlight examples of how miRNAs can successfully be incorporated into engineered cellular therapies.
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Affiliation(s)
- Marko Hasiuk
- Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland; Transplantation Immunology & Nephrology, Basel University Hospital, Petersgraben 4, CH-4031 Basel, Switzerland
| | - Marianne Dölz
- Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland; Transplantation Immunology & Nephrology, Basel University Hospital, Petersgraben 4, CH-4031 Basel, Switzerland
| | - Romina Marone
- Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland; Transplantation Immunology & Nephrology, Basel University Hospital, Petersgraben 4, CH-4031 Basel, Switzerland
| | - Lukas T Jeker
- Department of Biomedicine, Basel University Hospital and University of Basel, Hebelstrasse 20, CH-4031 Basel, Switzerland; Transplantation Immunology & Nephrology, Basel University Hospital, Petersgraben 4, CH-4031 Basel, Switzerland.
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21
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Zeng H, Guo S, Ren X, Wu Z, Liu S, Yao X. Current Strategies for Exosome Cargo Loading and Targeting Delivery. Cells 2023; 12:1416. [PMID: 37408250 DOI: 10.3390/cells12101416] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 04/29/2023] [Accepted: 05/15/2023] [Indexed: 07/07/2023] Open
Abstract
Extracellular vesicles (EVs) such as ectosomes and exosomes have gained attention as promising natural carriers for drug delivery. Exosomes, which range from 30 to 100 nm in diameter, possess a lipid bilayer and are secreted by various cells. Due to their high biocompatibility, stability, and low immunogenicity, exosomes are favored as cargo carriers. The lipid bilayer membrane of exosomes also offers protection against cargo degradation, making them a desirable candidate for drug delivery. However, loading cargo into exosomes remains to be a challenge. Despite various strategies such as incubation, electroporation, sonication, extrusion, freeze-thaw cycling, and transfection that have been developed to facilitate cargo loading, inadequate efficiency still persists. This review offers an overview of current cargo delivery strategies using exosomes and summarizes recent approaches for loading small-molecule, nucleic acid, and protein drugs into exosomes. With insights from these studies, we provide ideas for more efficient and effective delivery of drug molecules by using exosomes.
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Affiliation(s)
- Haifeng Zeng
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shaoshen Guo
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xuancheng Ren
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhenkun Wu
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shuwen Liu
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xingang Yao
- NMPA Key Laboratory for Research and Evaluation of Drug Metabolism, Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
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22
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Structure of the human DICER-pre-miRNA complex in a dicing state. Nature 2023; 615:331-338. [PMID: 36813958 DOI: 10.1038/s41586-023-05723-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 12/14/2022] [Indexed: 02/24/2023]
Abstract
Dicer has a key role in small RNA biogenesis, processing double-stranded RNAs (dsRNAs)1,2. Human DICER (hDICER, also known as DICER1) is specialized for cleaving small hairpin structures such as precursor microRNAs (pre-miRNAs) and has limited activity towards long dsRNAs-unlike its homologues in lower eukaryotes and plants, which cleave long dsRNAs. Although the mechanism by which long dsRNAs are cleaved has been well documented, our understanding of pre-miRNA processing is incomplete because structures of hDICER in a catalytic state are lacking. Here we report the cryo-electron microscopy structure of hDICER bound to pre-miRNA in a dicing state and uncover the structural basis of pre-miRNA processing. hDICER undergoes large conformational changes to attain the active state. The helicase domain becomes flexible, which allows the binding of pre-miRNA to the catalytic valley. The double-stranded RNA-binding domain relocates and anchors pre-miRNA in a specific position through both sequence-independent and sequence-specific recognition of the newly identified 'GYM motif'3. The DICER-specific PAZ helix is also reoriented to accommodate the RNA. Furthermore, our structure identifies a configuration of the 5' end of pre-miRNA inserted into a basic pocket. In this pocket, a group of arginine residues recognize the 5' terminal base (disfavouring guanine) and terminal monophosphate; this explains the specificity of hDICER and how it determines the cleavage site. We identify cancer-associated mutations in the 5' pocket residues that impair miRNA biogenesis. Our study reveals how hDICER recognizes pre-miRNAs with stringent specificity and enables a mechanistic understanding of hDICER-related diseases.
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