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Vasudevan Sajini D, Thaggikuppe Krishnamurthy P, Chakkittukandiyil A, Mudavath RN. Orientin Modulates Nrf2-ARE, PI3K/Akt, JNK-ERK1/2, and TLR4/NF-kB Pathways to Produce Neuroprotective Benefits in Parkinson's Disease. Neurochem Res 2024; 49:1577-1587. [PMID: 38276990 DOI: 10.1007/s11064-024-04099-8] [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: 08/08/2023] [Revised: 12/11/2023] [Accepted: 01/02/2024] [Indexed: 01/27/2024]
Abstract
Parkinson's disease (PD) is characterized by oxidative stress and neuroinflammation as key pathological features. Emerging evidence suggests that nuclear factor erythroid 2 related factor 2-antioxidant response element (Nrf2-ARE), phosphatidylinositol 3‑kinase-protein kinase B (PI3K-Akt), c-Jun N-terminal kinase-extracellular signal-regulated kinase 1/2 (JNK-ERK1/2), and toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-kB) pathways play pivotal roles in PD pathogenesis. Orientin, a phenolic phytoconstituent, has demonstrated modulatory potential on these pathways in various experimental conditions other than PD. In this study, we aimed to evaluate the neuroprotective effects of Orientin against rotenone-induced neurodegeneration in SH-SY5Y cell lines and the Swiss albino mice model of PD. Orientin was administered at doses 10 and 20 µM in cell lines and 10 and 20 mg/kg in mice, and its effects on rotenone-induced neurodegeneration were investigated. Oxidative stress markers including mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as inflammatory markers including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were measured. The expression levels of genes related to Nrf2-ARE (Nrf2), PI3K/Akt (Akt), JNK-ERK1/2 (TNF-α), and TLR4/NF-kB (TNF-α) pathways were measured to understand the modulatory effect of Orientin on these pathways. Additionally, behavioral studies assessing locomotor activity, muscle coordination, and muscle rigidity were conducted with mice. Our results indicate that Orientin dose-dependently attenuated rotenone-induced changes in oxidative stress markers, inflammatory markers, gene expression levels, and behavioral parameters. Therefore, our study concludes that Orientin exhibits significant neuroprotective benefits against rotenone-induced PD by modulating Nrf2-ARE, PI3K-Akt, JNK-ERK1/2, and TLR4/NF-kB pathways.
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Affiliation(s)
- Deepak Vasudevan Sajini
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, The Nilgiris, Tamil Nadu, 643 001, India
| | - Praveen Thaggikuppe Krishnamurthy
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, The Nilgiris, Tamil Nadu, 643 001, India.
| | - Amritha Chakkittukandiyil
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, The Nilgiris, Tamil Nadu, 643 001, India
| | - Ravi Naik Mudavath
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Ooty, The Nilgiris, Tamil Nadu, 643 001, India
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2
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Ramadan A, Ghanem HM, Mohamed AA, Elshobaky M, El Agawy W, Gawad EAHA, Eldeeb HH, Ezz Al Arab MR, Kamal MM. GPC3 gene expression and allelic discrimination of FZD7 gene in Egyptian patients with hepatocellular carcinoma. Rep Pract Oncol Radiother 2023; 28:485-495. [PMID: 37795234 PMCID: PMC10547423 DOI: 10.5603/rpor.a2023.0049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 07/19/2023] [Indexed: 10/06/2023] Open
Abstract
Background Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide, and especially in Egypt. Early diagnosis of HCC greatly improves the survival and prognosis of patients. Low sensitivity and specificity of alpha-fetoprotein (AFP) has led to the demand for novel biomarkers of HCC. The aim of the present study was to evaluate the validity of frizzled-7 (FZD7) and glypican-3 (GPC3) gene expression as potential biomarkers for HCC early diagnosis, and to investigate the association between FZD7 rs2280509 polymorphism and HCC risk. Materials and methods Quantification of FZD7 and GPC3 gene expression by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay, and genotyping FZD 7 (rs2280509 SNP) gene polymorphism using RT-PCR. Results The current results revealed that FZD7 gene expression had a greater area under the curve (AUC) for identifying HCC than GPC3 gene expression and AFP levels. The combination of the three markers as a panel showed a better diagnostic performance with a greater AUC than any of the single markers alone (p < 0.05). The FZD7 rs2280509 polymorphism (CT) was found to be significantly associated with an increased risk of HCC. The CT genotype and T allele were significantly more prevalent in the HCC group compared to either the cirrhosis (p = 0.03) or control groups (p = 0.0009 and 0.002; respectively). Conclusion FZD7 and GPC3 gene expressions have a complementary role in early HCC detection, with a greater diagnostic sensitivity and accuracy than AFP. In addition, FZD7 rs2280509 polymorphism is significantly associated with an increased risk of HCC in the Egyptian population.
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Affiliation(s)
- Amany Ramadan
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Hala M Ghanem
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Amal A Mohamed
- Department of Biochemistry and Molecular Biology, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt
| | - Mohamed Elshobaky
- Department of Internal Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Waleed El Agawy
- Department of Infectious Diseases, Faculty of Medicine, Port Said University, Cairo, Egypt
| | - Eman Al Hussain A Gawad
- Department of Chemical Pathology, National Cancer Institute (NCI), Cairo University, Cairo, Egypt
| | - Hala H Eldeeb
- Clinical and Chemical Pathology Department, El Sahel Teaching Hospital, Cairo, Egypt
| | | | - Maha M Kamal
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
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Lyu K, Kwok CK. RNA G-quadruplex (rG4) structure detection using RTS and SHALiPE assays. Methods Enzymol 2023; 691:63-80. [PMID: 37914452 DOI: 10.1016/bs.mie.2023.06.003] [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] [Indexed: 11/03/2023]
Abstract
RNA G-quadruplexes (rG4s) are non-canonical RNA secondary structures that were first reported several decades ago. Latest studies have suggested that they are widespread in the transcriptomes of diverse species, and they have been demonstrated to have key roles in various fundamental cellular processes. Among the RNA secondary structure probing assays developed recently, Reverse transcriptase stalling (RTS) and selective 2'-hydroxyl acylation analyzed by lithium ion-based primer extension (SHALiPE) enabled the identification and characterization of distinct structural features of an rG4 structure of interest. Herein, we present an experimental protocol describing in detail the procedures involved in the preparation of in vitro transcribed RNAs, buffers, and reagents for RTS and SHALiPE assays, as well as performing RTS and SHALiPE assays, to examine the formation of rG4 and reveal the rG4 structural conformation at nucleotide resolution in vitro. RTS and SHALiPE assays can be performed by an experienced molecular biologist or chemical biologist with a basic understanding of nucleic acids. The duration for the preparation of in vitro transcription and RNA preparation is around 2 days, and the duration for RTS and SHALiPE assays is approximately 5 h.
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Affiliation(s)
- Kaixin Lyu
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR, P.R. China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR, P.R. China; Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China.
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4
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Tsegay PS, Hernandez D, Qu F, Olatunji M, Mamun Y, Chapagain P, Liu Y. RNA-guided DNA base damage repair via DNA polymerase-mediated nick translation. Nucleic Acids Res 2022; 51:166-181. [PMID: 36533524 PMCID: PMC9841414 DOI: 10.1093/nar/gkac1178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/28/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
DNA repair is mediated by DNA synthesis guided by a DNA template. Recent studies have shown that DNA repair can also be accomplished by RNA-guided DNA synthesis. However, it remains unknown how RNA can guide DNA synthesis to repair DNA damage. In this study, we revealed the molecular mechanisms underlying RNA-guided DNA synthesis and base damage repair mediated by human repair DNA polymerases. We showed that pol β, pol κ, and pol ι predominantly synthesized one nucleotide, and pol η, pol ν, and pol θ synthesized multi-nucleotides during RNA-guided DNA base damage repair. The steady-state kinetics showed that pol η exhibited more efficient RNA-guided DNA synthesis than pol β. Using molecular dynamics simulation, we further revealed dynamic conformational changes of pol β and pol η and their structural basis to accommodate the RNA template and misoriented triphosphates of an incoming nucleotide. We demonstrated that RNA-guided base damage repair could be accomplished by the RNA-guided DNA strand-displacement synthesis and nick translation leading to nick ligation in a double-strand DNA region. Our study revealed a novel RNA-guided base damage repair pathway during transcription and DNA replication.
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Affiliation(s)
- Pawlos S Tsegay
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA
| | - Daniela Hernandez
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
| | - Fei Qu
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA
| | - Mustapha Olatunji
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA
| | - Yasir Mamun
- Biochemistry Ph.D. Program, Florida International University, Miami, FL, USA
| | - Prem Chapagain
- Department of Physics, Florida International University, Miami, FL, USA,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Yuan Liu
- To whom correspondence should be addressed. Tel: +1 305 348 3628; Fax: +1 305 348 2772;
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Ganesh PS, Kim SY. A comparison of conventional and advanced electroanalytical methods to detect SARS-CoV-2 virus: A concise review. CHEMOSPHERE 2022; 307:135645. [PMID: 35817176 PMCID: PMC9270057 DOI: 10.1016/j.chemosphere.2022.135645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
Respiratory viruses are a serious threat to human wellbeing that can cause pandemic disease. As a result, it is critical to identify virus in a timely, sensitive, and precise manner. The present novel coronavirus-2019 (COVID-19) disease outbreak has increased these concerns. The research of developing various methods for COVID-19 virus identification is one of the most rapidly growing research areas. This review article compares and addresses recent improvements in conventional and advanced electroanalytical approaches for detecting COVID-19 virus. The popular conventional methods such as polymerase chain reaction (PCR), loop mediated isothermal amplification (LAMP), serology test, and computed tomography (CT) scan with artificial intelligence require specialized equipment, hours of processing, and specially trained staff. Many researchers, on the other hand, focused on the invention and expansion of electrochemical and/or bio sensors to detect SARS-CoV-2, demonstrating that they could show a significant role in COVID-19 disease control. We attempted to meticulously summarize recent advancements, compare conventional and electroanalytical approaches, and ultimately discuss future prospective in the field. We hope that this review will be helpful to researchers who are interested in this interdisciplinary field and desire to develop more innovative virus detection methods.
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Affiliation(s)
- Pattan-Siddappa Ganesh
- Interaction Laboratory, Advanced Technology Research Center, Future Convergence Engineering, Korea University of Technology and Education (KoreaTech), Cheonan-si, Chungcheongnam-do, 330-708, Republic of Korea.
| | - Sang-Youn Kim
- Interaction Laboratory, Advanced Technology Research Center, Future Convergence Engineering, Korea University of Technology and Education (KoreaTech), Cheonan-si, Chungcheongnam-do, 330-708, Republic of Korea.
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Green MR, Sambrook J. Analysis of RNA by Primer Extension. Cold Spring Harb Protoc 2021; 2021:2021/5/pdb.prot101840. [PMID: 33941668 DOI: 10.1101/pdb.prot101840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
For mapping the 5' termini of mRNA molecules, primer extension is the method of choice. A purified oligonucleotide is end-labeled using polynucleotide kinase. The probe and a population of mRNA are allowed to hybridize, and the primers and template are used to carry out reverse transcription using an enzyme cloned from the Moloney murine leukemia virus. The primer extension products are separated on a denaturing polyacrylamide gel and analyzed by radiography.
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Gowri A, Ashwin Kumar N, Suresh Anand BS. Recent advances in nanomaterials based biosensors for point of care (PoC) diagnosis of Covid-19 - A minireview. Trends Analyt Chem 2021; 137:116205. [PMID: 33531721 PMCID: PMC7842193 DOI: 10.1016/j.trac.2021.116205] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Early diagnosis and ultrahigh sample throughput screening are the need of the hour to control the geological spread of the COVID-19 pandemic. Traditional laboratory tests such as enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) and computed tomography are implemented for the detection of COVID-19. However, they are limited by the laborious sample collection and processing procedures, longer wait time for test results and skilled technicians to operate sophisticated facilities. In this context, the point of care (PoC) diagnostic platform has proven to be the prospective approach in addressing the abovementioned challenges. This review emphasizes the mechanism of viral infection spread detailing the host-virus interaction, pathophysiology, and the recent advances in the development of affordable PoC diagnostic platforms for rapid and accurate diagnosis of COVID-19. First, the well-established optical and electrochemical biosensors are discussed. Subsequently, the recent advances in the development of PoC biosensors, including lateral flow immunoassays and other emerging techniques, are highlighted. Finally, a focus on integrating nanotechnology with wearables and smartphones to develop smart nanobiosensors is outlined, which could promote COVID-19 diagnosis accessible to both individuals and the mass population at patient care.
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Affiliation(s)
- Annasamy Gowri
- Department of Biomedical Engineering, Vel Tech Research Park, Vel Tech Rangarajan Dr.Sagunthala R & D Institute of Science and Technology, Avadi, Chennai 600 062, Tamil Nadu, India
| | - N Ashwin Kumar
- Department of Biomedical Engineering, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur 603203, Tamil Nadu, India
| | - B S Suresh Anand
- Department of Biomedical Engineering, Rajalakshmi Engineering College, Thandalam, Chennai 602 105, Tamil Nadu, India
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8
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Chang D, Serra L, Lu D, Mortazavi A, Dillman A. A Revised Adaptation of the Smart-Seq2 Protocol for Single-Nematode RNA-Seq. Methods Mol Biol 2021; 2170:79-99. [PMID: 32797452 DOI: 10.1007/978-1-0716-0743-5_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
The advancement of transcriptomic studies in plant parasitic nematodes will greatly benefit from the development of single-nematode RNA-seq methods. Since many plant parasitic nematodes are obligate parasites, it is often difficult to efficiently obtain sufficient amounts of nematodes for transcriptomic studies. Here we have adapted SMART-Seq2 for single-nematode RNA-seq requiring only an individual nematode for a sample replicate. This protocol provides a detailed step-by-step procedure of the RNA-seq workflow starting from lysis of the nematode to quantification of transcripts using a user-friendly online platform.
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Affiliation(s)
- Dennis Chang
- Department of Nematology, University of California, Riverside, CA, USA
| | - Lorrayne Serra
- Department of Developmental and Cell Biology, Center for Complex Biological Systems, University of California, Irvine, CA, USA
| | - Dihong Lu
- Department of Nematology, University of California, Riverside, CA, USA
| | - Ali Mortazavi
- Department of Developmental and Cell Biology, Center for Complex Biological Systems, University of California, Irvine, CA, USA.
| | - Adler Dillman
- Department of Nematology, University of California, Riverside, CA, USA.
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9
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Li Z, Tyler WA, Haydar TF. Lessons from single cell sequencing in CNS cell specification and function. Curr Opin Genet Dev 2020; 65:138-143. [PMID: 32679535 DOI: 10.1016/j.gde.2020.05.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 05/31/2020] [Indexed: 12/11/2022]
Abstract
Modern RNA sequencing methods have greatly increased our understanding of the molecular fingerprint of neurons, astrocytes and oligodendrocytes throughout the central nervous system (CNS). Technical approaches with greater sensitivity and throughput have uncovered new connections between gene expression, cell biology, and ultimately CNS function. In recent years, single cell RNA-sequencing (scRNA-seq) has made a large impact on the neurosciences by enhancing the resolution of types of cells that make up the CNS and shedding light on their developmental trajectories and how their diversity is modified across species. Here we will review the advantages, innovations, and challenges of the single cell genomics era and highlight how it has impacted our understanding of neurodevelopment and neurological function.
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Affiliation(s)
- Zhen Li
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - William A Tyler
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Tarik F Haydar
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA.
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10
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Green MR, Sambrook J. Amplification of cDNA Generated by Reverse Transcription of mRNA: Two-Step Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Cold Spring Harb Protoc 2019; 2019:2019/5/pdb.prot095190. [PMID: 31043555 DOI: 10.1101/pdb.prot095190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Reverse transcription-polymerase chain reaction (RT-PCR) is a powerful method to detect and synthesize cDNA copies of low-copy-number mRNAs. Two enzymes are used: reverse transcriptase to produce single-stranded cDNA copies, which are then used as templates in an amplification reaction catalyzed by a thermostable DNA polymerase. For this reason, the method is known as "two-step RT-PCR." This protocol describes the traditional method of RT-PCR in which the two synthetic reactions are performed separately and sequentially.
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11
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Jupp R, Dusanjh PK, Walding A, McHale M, Belfield GP, Delaney SJ. Rapid Simultaneous Cloning of Drug Targets from Multiple Mammalian Species. Altern Lab Anim 2019; 34:295-303. [PMID: 16831061 DOI: 10.1177/026119290603400310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A method for the routine, rapid and simultaneous cloning of drug targets from multiple mammalian species is described. This expedites the generation of recombinant proteins and cell lines that can provide alternatives to animal experiments. This was achieved by the collection of RNA from a comprehensive range of tissues from a variety of species, and the optimisation of cDNA synthesis. This "zooplate" has been successfully used for the simultaneous amplification and cloning of drug targets from multiple species. These products have subsequently been used to develop in vitro assays that support efficacy and safety studies in new drug discovery programmes. Within the framework of the Three Rs, these reagents can reduce the number of animals required to provide material for ex vivo assays and can refine the in vivo studies that are still necessary.
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Affiliation(s)
- Rachael Jupp
- Department of Molecular Biology, AstraZeneca R & D Charnwood, Loughborough, Leicestershire LE11 5RH, UK
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12
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Palikša S, Alzbutas G, Skirgaila R. Decreased Km to dNTPs is an essential M-MuLV reverse transcriptase adoption required to perform efficient cDNA synthesis in One-Step RT-PCR assay. Protein Eng Des Sel 2019; 31:79-89. [PMID: 29608777 DOI: 10.1093/protein/gzy003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/05/2018] [Indexed: 01/27/2023] Open
Abstract
Personalized medicine and advanced diagnostic tools based on RNA analysis are focusing on fast and direct One-Step RT-PCR assays. First strand complementary DNA (cDNA) synthesized by the reverse transcriptase (RT) is exponentially amplified in the end-point or real-time PCR. Even a minor discrepancy in PCR conditions would result in big deviations during the data analysis. Thus, One-Step RT-PCR composition is typically based on the PCR buffer. In this study, we have used compartmentalized ribosome display technique for in vitro evolution of the Moloney Murine Leukemia Virus reverse transcriptase (M-MuLV RT) that would be able to perform efficient full-length cDNA synthesis in PCR buffer optimized for Thermus aquaticus DNA polymerase. The most frequent mutations found in a selected library were analyzed. Aside from the mutations, which switch off RNase H activity of RT and are beneficial for the full-length cDNA synthesis, we have identified several mutations in the active center of the enzyme (Q221R and V223A/M), which result in 4-5-fold decrease of Km for dNTPs (<0.2 mM). The selected mutations are in surprising agreement with the natural evolution process because they transformed the active center from the oncoretroviral M-MuLV RT-type to the lenitiviral enzyme-type. We believe that this was the major and essential phenotypic adjustment required to perform fast and efficient cDNA synthesis in PCR buffer at 0.2-mM concentration of each dNTP.
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Affiliation(s)
- S Palikša
- Thermo Fisher Scientific Baltics, UAB, LT-02241 Vilnius, Lithuania.,JSC Diagnolita, LT-10257 Vilnius, Lithuania
| | - G Alzbutas
- Thermo Fisher Scientific Baltics, UAB, LT-02241 Vilnius, Lithuania
| | - R Skirgaila
- Thermo Fisher Scientific Baltics, UAB, LT-02241 Vilnius, Lithuania
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Parra M, Jung J, Boone TD, Tran L, Blaber EA, Brown M, Chin M, Chinn T, Cohen J, Doebler R, Hoang D, Hyde E, Lera M, Luzod LT, Mallinson M, Marcu O, Mohamedaly Y, Ricco AJ, Rubins K, Sgarlato GD, Talavera RO, Tong P, Uribe E, Williams J, Wu D, Yousuf R, Richey CS, Schonfeld J, Almeida EAC. Microgravity validation of a novel system for RNA isolation and multiplex quantitative real time PCR analysis of gene expression on the International Space Station. PLoS One 2017; 12:e0183480. [PMID: 28877184 PMCID: PMC5587110 DOI: 10.1371/journal.pone.0183480] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 08/04/2017] [Indexed: 11/29/2022] Open
Abstract
The International Space Station (ISS) National Laboratory is dedicated to studying the effects of space on life and physical systems, and to developing new science and technologies for space exploration. A key aspect of achieving these goals is to operate the ISS National Lab more like an Earth-based laboratory, conducting complex end-to-end experimentation, not limited to simple microgravity exposure. Towards that end NASA developed a novel suite of molecular biology laboratory tools, reagents, and methods, named WetLab-2, uniquely designed to operate in microgravity, and to process biological samples for real-time gene expression analysis on-orbit. This includes a novel fluidic RNA Sample Preparation Module and fluid transfer devices, all-in-one lyophilized PCR assays, centrifuge, and a real-time PCR thermal cycler. Here we describe the results from the WetLab-2 validation experiments conducted in microgravity during ISS increment 47/SPX-8. Specifically, quantitative PCR was performed on a concentration series of DNA calibration standards, and Reverse Transcriptase-quantitative PCR was conducted on RNA extracted and purified on-orbit from frozen Escherichia coli and mouse liver tissue. Cycle threshold (Ct) values and PCR efficiencies obtained on-orbit from DNA standards were similar to Earth (1 g) controls. Also, on-orbit multiplex analysis of gene expression from bacterial cells and mammalian tissue RNA samples was successfully conducted in about 3 h, with data transmitted within 2 h of experiment completion. Thermal cycling in microgravity resulted in the trapping of gas bubbles inside septa cap assay tubes, causing small but measurable increases in Ct curve noise and variability. Bubble formation was successfully suppressed in a rapid follow-up on-orbit experiment using standard caps to pressurize PCR tubes and reduce gas release during heating cycles. The WetLab-2 facility now provides a novel operational on-orbit research capability for molecular biology and demonstrates the feasibility of more complex wet bench experiments in the ISS National Lab environment.
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Affiliation(s)
- Macarena Parra
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Jimmy Jung
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- KBRWyle, Mountain View, California, United States of America
| | - Travis D. Boone
- Office of the Director, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Luan Tran
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
- KBRWyle, Mountain View, California, United States of America
| | - Elizabeth A. Blaber
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
- Universities Space Research Association, Mountain View, California, United States of America
| | - Mark Brown
- Applications Development, Claremont Biosolutions, Upland, California, United States of America
| | - Matthew Chin
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Tori Chinn
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Jacob Cohen
- Office of the Director, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Robert Doebler
- Applications Development, Claremont Biosolutions, Upland, California, United States of America
| | - Dzung Hoang
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Elizabeth Hyde
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Matthew Lera
- KBRWyle, Mountain View, California, United States of America
- Flight Systems Implementation Branch, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Louie T. Luzod
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Mark Mallinson
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Oana Marcu
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
- KBRWyle, Mountain View, California, United States of America
| | - Youssef Mohamedaly
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Antonio J. Ricco
- Mission Design Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Stanford University, Palo Alto, California, United States of America
| | - Kathleen Rubins
- NASA Astronaut Corps, NASA Johnson Space Center, Houston, Texas, United States of America
| | - Gregory D. Sgarlato
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- KBRWyle, Mountain View, California, United States of America
| | - Rafael O. Talavera
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Peter Tong
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
- Millenium Engineering & Integration Co, Mountain View, California, United States of America
| | - Eddie Uribe
- Universities Space Research Association, Mountain View, California, United States of America
| | - Jeffrey Williams
- NASA Astronaut Corps, NASA Johnson Space Center, Houston, Texas, United States of America
| | - Diana Wu
- KBRWyle, Mountain View, California, United States of America
- Mission Design Division, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Rukhsana Yousuf
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
- KBRWyle, Mountain View, California, United States of America
| | - Charles S. Richey
- Universities Space Research Association, Mountain View, California, United States of America
| | - Julie Schonfeld
- Engineering Systems Division, NASA Ames Research Center, Moffett Field, California, United States of America
| | - Eduardo A. C. Almeida
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California, United States of America
- * E-mail:
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14
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Miranda JA, Steward GF. Variables influencing the efficiency and interpretation of reverse transcription quantitative PCR (RT-qPCR): An empirical study using Bacteriophage MS2. J Virol Methods 2016; 241:1-10. [PMID: 27940257 DOI: 10.1016/j.jviromet.2016.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 09/16/2016] [Accepted: 12/02/2016] [Indexed: 11/28/2022]
Abstract
Reverse transcription, quantitative PCR (RT-qPCR) is a sensitive method for quantification of specific RNA targets, but the first step of the assay, reverse transcription, is notoriously variable and sensitive to reaction conditions. In this study, we used purified Bacteriophage MS2 genomic RNA as a model virus target to test two different RT enzymes (SuperScript II and SuperScript III), two RT-priming strategies (gene-specific primers and random hexamers), and varying background RNA concentrations (0-50ngμl-1) to determine how these variables influence the efficiency of reverse transcription over a range of target concentrations (101-107 copies μl-1). The efficiency of the RT reaction was greatly improved by increasing both background RNA and primer concentrations, but the benefit provided by background RNA was source dependent. At a given target concentration, similar RT efficiencies were achieved with gene-specific primers and random hexamers, but the latter required much higher concentrations. With random hexamers, we observed a systematic variation in RT reaction efficiency as a function of target concentration. Using an RNA standard curve that was also subject to RT effectively normalized for this systematic variability, but the assay accuracy depended critically on the length of the standard RNA extending to the 3' end of the qPCR target site. Our results shed some light on previous contradictory conclusions in the literature, and provide insights that may aid in the design of RT-qPCR assays and the design of synthetic RNA standards when full-length material is not available.
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Affiliation(s)
- Jaclyn A Miranda
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, Hawai'i 96822, United States
| | - Grieg F Steward
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, Hawai'i 96822, United States.
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15
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Identifying Stable Reference Genes for qRT-PCR Normalisation in Gene Expression Studies of Narrow-Leafed Lupin (Lupinus angustifolius L.). PLoS One 2016; 11:e0148300. [PMID: 26872362 PMCID: PMC4752343 DOI: 10.1371/journal.pone.0148300] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/15/2016] [Indexed: 11/19/2022] Open
Abstract
Quantitative Reverse Transcription PCR (qRT-PCR) is currently one of the most popular, high-throughput and sensitive technologies available for quantifying gene expression. Its accurate application depends heavily upon normalisation of gene-of-interest data with reference genes that are uniformly expressed under experimental conditions. The aim of this study was to provide the first validation of reference genes for Lupinus angustifolius (narrow-leafed lupin, a significant grain legume crop) using a selection of seven genes previously trialed as reference genes for the model legume, Medicago truncatula. In a preliminary evaluation, the seven candidate reference genes were assessed on the basis of primer specificity for their respective targeted region, PCR amplification efficiency, and ability to discriminate between cDNA and gDNA. Following this assessment, expression of the three most promising candidates [Ubiquitin C (UBC), Helicase (HEL), and Polypyrimidine tract-binding protein (PTB)] was evaluated using the NormFinder and RefFinder statistical algorithms in two narrow-leafed lupin lines, both with and without vernalisation treatment, and across seven organ types (cotyledons, stem, leaves, shoot apical meristem, flowers, pods and roots) encompassing three developmental stages. UBC was consistently identified as the most stable candidate and has sufficiently uniform expression that it may be used as a sole reference gene under the experimental conditions tested here. However, as organ type and developmental stage were associated with greater variability in relative expression, it is recommended using UBC and HEL as a pair to achieve optimal normalisation. These results highlight the importance of rigorously assessing candidate reference genes for each species across a diverse range of organs and developmental stages. With emerging technologies, such as RNAseq, and the completion of valuable transcriptome data sets, it is possible that other potentially more suitable reference genes will be identified for this species in future.
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16
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Heyer EE, Ozadam H, Ricci EP, Cenik C, Moore MJ. An optimized kit-free method for making strand-specific deep sequencing libraries from RNA fragments. Nucleic Acids Res 2014; 43:e2. [PMID: 25505164 PMCID: PMC4288154 DOI: 10.1093/nar/gku1235] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Deep sequencing of strand-specific cDNA libraries is now a ubiquitous tool for identifying and quantifying RNAs in diverse sample types. The accuracy of conclusions drawn from these analyses depends on precise and quantitative conversion of the RNA sample into a DNA library suitable for sequencing. Here, we describe an optimized method of preparing strand-specific RNA deep sequencing libraries from small RNAs and variably sized RNA fragments obtained from ribonucleoprotein particle footprinting experiments or fragmentation of long RNAs. Our approach works across a wide range of input amounts (400 pg to 200 ng), is easy to follow and produces a library in 2–3 days at relatively low reagent cost, all while giving the user complete control over every step. Because all enzymatic reactions were optimized and driven to apparent completion, sequence diversity and species abundance in the input sample are well preserved.
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Affiliation(s)
- Erin E Heyer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Hakan Ozadam
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Emiliano P Ricci
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Can Cenik
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Melissa J Moore
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
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17
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Park HR, Kamau PW, Korte C, Loch-Caruso R. Tetrabromobisphenol A activates inflammatory pathways in human first trimester extravillous trophoblasts in vitro. Reprod Toxicol 2014; 50:154-62. [PMID: 25461914 DOI: 10.1016/j.reprotox.2014.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/02/2014] [Accepted: 10/07/2014] [Indexed: 01/25/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is a widely used flame retardant. Despite the presence of TBBPA in gestational tissues and the importance of proper regulation of inflammatory networks for successful pregnancy, there is no prior study on the effects of TBBPA on inflammatory responses in gestational tissues. The present study aimed to investigate TBBPA activation of inflammatory pathways, specifically cytokine and prostaglandin production, in the human first trimester placental cell line HTR-8/SVneo. TBBPA enhanced release of interleukin (IL)-6, IL-8, and prostaglandin E2 (PGE2), and suppressed TGF-β release in HTR-8/SVneo cells. The lowest effective concentration was 10 μM TBBPA. A commercial immune response PCR array revealed increased expression of genes involved in inflammatory pathways stimulated by TBBPA in HTR-8/SVneo cells. Because proper regulation of inflammatory mediators in the gestational compartment is necessary for normal placental development and successful pregnancy, further investigation on the impact of TBBPA-stimulated responses on trophoblast function is warranted.
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Affiliation(s)
- Hae-Ryung Park
- Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA.
| | - Patricia W Kamau
- Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA
| | - Cassandra Korte
- College of Arts and Sciences, Lynn University, 3601 North Military Trail, Boca Raton, FL 33431, USA
| | - Rita Loch-Caruso
- Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA
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18
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Sanders R, Mason DJ, Foy CA, Huggett JF. Evaluation of digital PCR for absolute RNA quantification. PLoS One 2013; 8:e75296. [PMID: 24073259 PMCID: PMC3779174 DOI: 10.1371/journal.pone.0075296] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/15/2013] [Indexed: 12/29/2022] Open
Abstract
Gene expression measurements detailing mRNA quantities are widely employed in molecular biology and are increasingly important in diagnostic fields. Reverse transcription (RT), necessary for generating complementary DNA, can be both inefficient and imprecise, but remains a quintessential RNA analysis tool using qPCR. This study developed a Transcriptomic Calibration Material and assessed the RT reaction using digital (d)PCR for RNA measurement. While many studies characterise dPCR capabilities for DNA quantification, less work has been performed investigating similar parameters using RT-dPCR for RNA analysis. RT-dPCR measurement using three, one-step RT-qPCR kits was evaluated using single and multiplex formats when measuring endogenous and synthetic RNAs. The best performing kit was compared to UV quantification and sensitivity and technical reproducibility investigated. Our results demonstrate assay and kit dependent RT-dPCR measurements differed significantly compared to UV quantification. Different values were reported by different kits for each target, despite evaluation of identical samples using the same instrument. RT-dPCR did not display the strong inter-assay agreement previously described when analysing DNA. This study demonstrates that, as with DNA measurement, RT-dPCR is capable of accurate quantification of low copy RNA targets, but the results are both kit and target dependent supporting the need for calibration controls.
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Affiliation(s)
- Rebecca Sanders
- Molecular and Cell Biology, LGC, Teddington, United Kingdom ; Cardiff School of BioSciences, The Sir Martin Evans Building, Cardiff, United Kingdom
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19
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Baranauskas A, Paliksa S, Alzbutas G, Vaitkevicius M, Lubiene J, Letukiene V, Burinskas S, Sasnauskas G, Skirgaila R. Generation and characterization of new highly thermostable and processive M-MuLV reverse transcriptase variants. Protein Eng Des Sel 2012; 25:657-68. [PMID: 22691702 DOI: 10.1093/protein/gzs034] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In vitro synthesis of cDNA is one of the most important techniques in present molecular biology. Faithful synthesis of long cDNA on highly structured RNA templates requires thermostable and processive reverse transcriptases. In a recent attempt to increase the thermostability of the wt Moloney Murine leukemia virus reverse transcriptase (M-MuLV RT), we have employed the compartmentalized ribosome display (CRD) evolution in vitro technique and identified a large set of previously unknown mutations that enabled cDNA synthesis at elevated temperatures. In this study, we have characterized a group of the M-MuLV RT variants (28 novel amino acid positions, 84 point mutants) carrying the individual mutations. The performance of point mutants (thermal inactivation rate, substrate-binding affinity and processivity) correlated remarkably well with the mutation selection frequency in the CRD experiment. By combining the best-performing mutations D200N, L603W, T330P, L139P and E607K, we have generated highly processive and thermostable multiply-mutated M-MuLV RT variants. The processivity of the best-performing multiple mutant increased to 1500 nt (65-fold improvement in comparison to the wt enzyme), and the maximum temperature of the full-length 7.5-kb cDNA synthesis was raised to 62°C (17° higher in comparison with the wt enzyme).
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20
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Moser MJ, DiFrancesco RA, Gowda K, Klingele AJ, Sugar DR, Stocki S, Mead DA, Schoenfeld TW. Thermostable DNA polymerase from a viral metagenome is a potent RT-PCR enzyme. PLoS One 2012; 7:e38371. [PMID: 22675552 PMCID: PMC3366922 DOI: 10.1371/journal.pone.0038371] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 05/04/2012] [Indexed: 02/03/2023] Open
Abstract
Viral metagenomic libraries are a promising but previously untapped source of new reagent enzymes. Deep sequencing and functional screening of viral metagenomic DNA from a near-boiling thermal pool identified clones expressing thermostable DNA polymerase (Pol) activity. Among these, 3173 Pol demonstrated both high thermostability and innate reverse transcriptase (RT) activity. We describe the biochemistry of 3173 Pol and report its use in single-enzyme reverse transcription PCR (RT-PCR). Wild-type 3173 Pol contains a proofreading 3′-5′ exonuclease domain that confers high fidelity in PCR. An easier-to-use exonuclease-deficient derivative was incorporated into a PyroScript RT-PCR master mix and compared to one-enzyme (Tth) and two-enzyme (MMLV RT/Taq) RT-PCR systems for quantitative detection of MS2 RNA, influenza A RNA, and mRNA targets. Specificity and sensitivity of 3173 Pol-based RT-PCR were higher than Tth Pol and comparable to three common two-enzyme systems. The performance and simplified set-up make this enzyme a potential alternative for research and molecular diagnostics.
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21
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Ong C, Tai W, Sarma A, Opal SM, Artenstein AW, Tripathi A. Ligation with nucleic acid sequence-based amplification. J Mol Diagn 2012; 14:206-13. [PMID: 22449695 DOI: 10.1016/j.jmoldx.2012.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 12/14/2011] [Accepted: 01/11/2012] [Indexed: 01/11/2023] Open
Abstract
This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays.
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Affiliation(s)
- Carmichael Ong
- Center for Biomedical Engineering, School of Engineering and Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
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22
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Radzvilavicius T, Lagunavicius A. Selective inactivation of M-MuLV RT RNase H activity by site-directed PEGylation: an improved ability to synthesize long cDNA molecules. N Biotechnol 2012; 29:285-92. [DOI: 10.1016/j.nbt.2011.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/27/2011] [Accepted: 07/14/2011] [Indexed: 10/18/2022]
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23
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Dresang LR, Teuton JR, Feng H, Jacobs JM, Camp DG, Purvine SO, Gritsenko MA, Li Z, Smith RD, Sugden B, Moore PS, Chang Y. Coupled transcriptome and proteome analysis of human lymphotropic tumor viruses: insights on the detection and discovery of viral genes. BMC Genomics 2011; 12:625. [PMID: 22185355 PMCID: PMC3282826 DOI: 10.1186/1471-2164-12-625] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 12/20/2011] [Indexed: 11/10/2022] Open
Abstract
Background Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are related human tumor viruses that cause primary effusion lymphomas (PEL) and Burkitt's lymphomas (BL), respectively. Viral genes expressed in naturally-infected cancer cells contribute to disease pathogenesis; knowing which viral genes are expressed is critical in understanding how these viruses cause cancer. To evaluate the expression of viral genes, we used high-resolution separation and mass spectrometry coupled with custom tiling arrays to align the viral proteomes and transcriptomes of three PEL and two BL cell lines under latent and lytic culture conditions. Results The majority of viral genes were efficiently detected at the transcript and/or protein level on manipulating the viral life cycle. Overall the correlation of expressed viral proteins and transcripts was highly complementary in both validating and providing orthogonal data with latent/lytic viral gene expression. Our approach also identified novel viral genes in both KSHV and EBV, and extends viral genome annotation. Several previously uncharacterized genes were validated at both transcript and protein levels. Conclusions This systems biology approach coupling proteome and transcriptome measurements provides a comprehensive view of viral gene expression that could not have been attained using each methodology independently. Detection of viral proteins in combination with viral transcripts is a potentially powerful method for establishing virus-disease relationships.
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Affiliation(s)
- Lindsay R Dresang
- Cancer Virology Program, University of Pittsburgh Cancer Institute Hillman Cancer Research Pavilion 5117 Centre Ave,, Pittsburgh, PA 15213 USA
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24
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Nicotinic receptors on rat alveolar macrophages dampen ATP-induced increase in cytosolic calcium concentration. Respir Res 2010; 11:133. [PMID: 20920278 PMCID: PMC2955664 DOI: 10.1186/1465-9921-11-133] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 09/29/2010] [Indexed: 01/28/2023] Open
Abstract
Background Nicotinic acetylcholine receptors (nAChR) have been identified on a variety of cells of the immune system and are generally considered to trigger anti-inflammatory events. In the present study, we determine the nAChR inventory of rat alveolar macrophages (AM), and investigate the cellular events evoked by stimulation with nicotine. Methods Rat AM were isolated freshly by bronchoalveolar lavage. The expression of nAChR subunits was analyzed by RT-PCR, immunohistochemistry, and Western blotting. To evaluate function of nAChR subunits, electrophysiological recordings and measurements of intracellular calcium concentration ([Ca2+]i) were conducted. Results Positive RT-PCR results were obtained for nAChR subunits α3, α5, α9, α10, β1, and β2, with most stable expression being noted for subunits α9, α10, β1, and β2. Notably, mRNA coding for subunit α7 which is proposed to convey the nicotinic anti-inflammatory response of macrophages from other sources than the lung was not detected. RT-PCR data were supported by immunohistochemistry on AM isolated by lavage, as well as in lung tissue sections and by Western blotting. Neither whole-cell patch clamp recordings nor measurements of [Ca2+]i revealed changes in membrane current in response to ACh and in [Ca2+]i in response to nicotine, respectively. However, nicotine (100 μM), given 2 min prior to ATP, significantly reduced the ATP-induced rise in [Ca2+]i by 30%. This effect was blocked by α-bungarotoxin and did not depend on the presence of extracellular calcium. Conclusions Rat AM are equipped with modulatory nAChR with properties distinct from ionotropic nAChR mediating synaptic transmission in the nervous system. Their stimulation with nicotine dampens ATP-induced Ca2+-release from intracellular stores. Thus, the present study identifies the first acute receptor-mediated nicotinic effect on AM with anti-inflammatory potential.
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25
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Arezi B, McCarthy M, Hogrefe H. Mutant of Moloney murine leukemia virus reverse transcriptase exhibits higher resistance to common RT-qPCR inhibitors. Anal Biochem 2010; 400:301-3. [DOI: 10.1016/j.ab.2010.01.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 01/05/2010] [Accepted: 01/19/2010] [Indexed: 10/19/2022]
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26
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Sieber MW, Recknagel P, Glaser F, Witte OW, Bauer M, Claus RA, Frahm C. Substantial performance discrepancies among commercially available kits for reverse transcription quantitative polymerase chain reaction: a systematic comparative investigator-driven approach. Anal Biochem 2010; 401:303-11. [PMID: 20226159 DOI: 10.1016/j.ab.2010.03.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 03/05/2010] [Accepted: 03/05/2010] [Indexed: 11/25/2022]
Abstract
Reverse transcription followed by quantitative polymerase chain reaction (rt-qPCR) has become the state-of-the-art tool for quantification of nucleic acids. However, there are still significant problems associated with its sensitivity, reproducibility, and efficiency and the choice of an appropriate rt-qPCR kit. The purpose of this article is to give insights into strategies to optimize and validate the performance of currently available kits for rt-qPCR and to provide up-to-date information about the benefits, potentials, and pitfalls of rt-qPCR assays. A selection of 9 complementary DNA (cDNA) synthesis and 12 qPCR kits were tested using samples obtained from three species (mouse, rat, and human) and three transcripts (Gapdh, Actb, and Hmbs) under highly standardized conditions. Kits with outstanding performance were further analyzed to identify the dynamic range for a reliable quantification of messenger RNA (mRNA). Reverse transcription efficiency varied up to 90-fold depending on the choice of reverse transcriptase, priming strategy, and assay volume. The qPCR kit test revealed variations in mean relative amplification efficiency ranging from 54% to 171%. We conclude that currently available kits for rt-qPCR vary considerably. However, with an appropriate validation strategy and knowledge about capabilities of a particular kit, sensitivity, efficiency, and reliability could be improved significantly.
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Affiliation(s)
- Matthias W Sieber
- Hans Berger Clinic for Neurology, Jena University Hospital, D-07747 Jena, Germany
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27
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Increased Thermostability and Fidelity of DNA Synthesis of Wild-Type and Mutant HIV-1 Group O Reverse Transcriptases. J Mol Biol 2009; 392:872-84. [DOI: 10.1016/j.jmb.2009.07.081] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/24/2009] [Accepted: 07/28/2009] [Indexed: 11/18/2022]
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28
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Expression of IFN-gamma, TNF-alpha, IL-10 and TGF-beta in lymph nodes associates with parasite load and clinical form of disease in dogs naturally infected with Leishmania (Leishmania) chagasi. Vet Immunol Immunopathol 2008; 128:349-58. [PMID: 19124159 DOI: 10.1016/j.vetimm.2008.11.020] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 10/29/2008] [Accepted: 11/03/2008] [Indexed: 11/21/2022]
Abstract
American visceral leishmaniasis is a zoonosis of the New World. Dogs are the main reservoir of the disease and there is much interest in the understanding of mechanisms implicated in protection against canine infection. Nevertheless, most studies in dogs have not been carried out in organs that are targets of infection. This work is first to report the profile of cytokines and parasite burdens, as determined by real-time PCR, in the lymph nodes of dogs naturally infected with Leishmania chagasi. With this purpose, 18 mongrel dogs were divided in three groups: control non-infected dogs (n=6) and naturally infected animals with L. chagasi, asymptomatic (n=6) and symptomatic (n=6). Parasite burden in lymph nodes was 73-fold greater in symptomatic than asymptomatic animals. Prescapular lymph nodes of asymptomatic dogs had the highest expression of IFN-gamma and TNF-alpha and low parasite burden, indicating that these cytokines play a role in protection against infection. Highest expression of IL-10 and TGF-beta and high parasite burden were observed in symptomatic dogs, suggesting a role for these cytokines in the progression of disease. Hence, the balance of expression of IFN-gamma and TNF-alpha (protective) and IL-10 and TGF-beta (disease progression) in lymph nodes determine parasite burden and clinical expression in naturally infected dogs.
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29
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Guntz E, Dumont H, Pastijn E, de Kerchove d’Exaerde A, Azdad K, Sosnowski M, Schiffmann SN, Gall D. Expression of Adenosine A2A Receptors in the Rat Lumbar Spinal Cord and Implications in the Modulation of N-Methyl-d-Aspartate Receptor Currents. Anesth Analg 2008; 106:1882-9. [DOI: 10.1213/ane.0b013e318173251f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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Tijerina P, Mohr S, Russell R. DMS footprinting of structured RNAs and RNA-protein complexes. Nat Protoc 2008; 2:2608-23. [PMID: 17948004 DOI: 10.1038/nprot.2007.380] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe a protocol in which dimethyl sulfate (DMS) modification of the base-pairing faces of unpaired adenosine and cytidine nucleotides is used for structural analysis of RNAs and RNA-protein complexes (RNPs). The protocol is optimized for RNAs of small to moderate size (< or = 500 nt). The RNA or RNP is first exposed to DMS under conditions that promote formation of the folded structure or complex, as well as 'control' conditions that do not allow folding or complex formation. The positions and extents of modification are then determined by primer extension, polyacrylamide gel electrophoresis and quantitative analysis. From changes in the extent of modification upon folding or protein binding (appearance of a 'footprint'), it is possible to detect local changes in the secondary and tertiary structure of RNA, as well as the formation of RNA-protein contacts. This protocol takes 1.5-3 d to complete, depending on the type of analysis used.
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Affiliation(s)
- Pilar Tijerina
- Department of Chemistry and Biochemistry and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA
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31
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Abstract
The polymerase chain reaction (PCR) has become one of the most important tools in molecular diagnostics, providing exquisite sensitivity and specificity for detection of nucleic acid targets. Real-time monitoring of PCR has simplified and accelerated PCR laboratory procedures and has increased information obtained from specimens including routine quantification and differentiation of amplification products. Clinical diagnostic applications and uses of real-time PCR are growing exponentially, real-time PCR is rapidly replacing traditional PCR, and new diagnostic uses likely will emerge. This review analyzes the scope of present and potential future clinical diagnostic applications of this powerful technique. Critical discussions focus on basic concepts, variations, data analysis, instrument platforms, signal detection formats, sample collection, assay design, and execution of real-time PCR.
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Affiliation(s)
- Bernhard Kaltenboeck
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
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Csako G. Present and future of rapid and/or high-throughput methods for nucleic acid testing. Clin Chim Acta 2005; 363:6-31. [PMID: 16102738 DOI: 10.1016/j.cccn.2005.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 07/03/2005] [Accepted: 07/03/2005] [Indexed: 12/21/2022]
Abstract
BACKGROUND Behind the success of 'completing' the human genome project was a more than 30-year history of technical innovations for nucleic acid testing. METHODS Discovery of specific restriction endonucleases and reverse transcriptase was followed shortly by the development of the first diagnostic nucleic acid tests in the early 1970s. Introduction of Southern, Northern and dot blotting and DNA sequencing later in the 1970s considerably advanced the diagnostic capabilities. Nevertheless, it was the discovery of the polymerase chain reaction (PCR) in 1985 that led to an exponential growth in molecular biology and the introduction of practicable nucleic acid tests in the routine laboratory. The past two decades witnessed a continuing explosion of technological innovations in molecular diagnostics. In addition to classic PCR and reverse transcriptase PCR, numerous variations of PCR and alternative amplification techniques along with an ever-increasing variety of detection chemistries, closed tube (homogeneous) assays, and automated systems were developed. Discovery of real-time quantitative PCR and the development of oligonucleotide microarrays, the 'DNA chip', in the 1990s heralded the beginning of another revolution in molecular biology and diagnostics that is still in progress.
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Affiliation(s)
- Gyorgy Csako
- Department of Laboratory Medicine, W.G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892-1508, USA.
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Uenishi H, Eguchi T, Suzuki K, Sawazaki T, Toki D, Shinkai H, Okumura N, Hamasima N, Awata T. PEDE (Pig EST Data Explorer): construction of a database for ESTs derived from porcine full-length cDNA libraries. Nucleic Acids Res 2004; 32:D484-8. [PMID: 14681463 PMCID: PMC308771 DOI: 10.1093/nar/gkh037] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We generated the PEDE (Pig EST Data Explorer; http://pede.dna.affrc.go.jp/) database using sequences assembled from porcine 5' ESTs from oligo-capped full-length cDNA libraries. Thus far we have performed EST analysis of various organs (thymus, spleen, uterus, lung, liver, ovary and peripheral blood mononuclear cells) and assembled 68,076 high-quality sequences into 5546 contigs and 28,461 singlets. PEDE provides a search interface for getting results of homology searches and enables users to obtain information on sequence data and cDNA clones of interest. Single-nucleotide polymorphisms detected through comparison of the EST sequences are classified by origin (western and oriental breeds) and are searchable in the database. This database system can accelerate analyses of livestock traits and yields information that can lead to new applications in pigs as model systems for medical research.
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Affiliation(s)
- Hirohide Uenishi
- Genome Research Department, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba, Ibaraki 305-8602, Japan.
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Jackson A, Jiao PE, Ni I, Fu GK. Agarose gel size fractionation of RNA for the cloning of full-length cDNAs. Anal Biochem 2003; 323:252-5. [PMID: 14656534 DOI: 10.1016/j.ab.2003.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Alan Jackson
- Incyte Corp, 3160 Porter Dr, Palo Alto, CA 94304, USA
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35
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Gerard GF, Potter RJ, Smith MD, Rosenthal K, Dhariwal G, Lee J, Chatterjee DK. The role of template-primer in protection of reverse transcriptase from thermal inactivation. Nucleic Acids Res 2002; 30:3118-29. [PMID: 12136094 PMCID: PMC135738 DOI: 10.1093/nar/gkf417] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We compared the thermal stabilities of wild-type recombinant avian myeloblastosis virus (AMV) and Moloney murine leukemia virus (M-MLV) reverse transcriptase (RT) with those of mutants of the recombinant enzymes lacking RNase H activity. They differed in resistance to thermal inactivation at elevated temperatures in the presence of an RNA/DNA template-primer. RNase H-minus RTs retained the ability to efficiently synthesize cDNA at much higher temperatures. We show that the structure of the template-primer has a critical bearing on protection of RT from thermal inactivation. RT RNase H activity rapidly alters the structure of the template-primer to forms less tightly bound by RT and thus less able to protect the enzyme at elevated temperatures. We also found that when comparing wild-type or mutant AMV RT with the respective M-MLV RT, the avian enzymes retained more DNA synthetic activity at elevated temperatures than murine RTs. Enzyme, template-primer interaction again played the most significant role in producing these differences. AMV RT binds much tighter to template- primer and has a much greater tendency to remain bound during cDNA synthesis than M-MLV RT and therefore is better protected from heat inactivation.
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Affiliation(s)
- Gary F Gerard
- Invitrogen Corporation, 7335 Executive Way, Frederick, MD 21704, USA.
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36
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Liss B, Franz O, Sewing S, Bruns R, Neuhoff H, Roeper J. Tuning pacemaker frequency of individual dopaminergic neurons by Kv4.3L and KChip3.1 transcription. EMBO J 2001; 20:5715-24. [PMID: 11598014 PMCID: PMC125678 DOI: 10.1093/emboj/20.20.5715] [Citation(s) in RCA: 245] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The activity of dopaminergic (DA) substantia nigra (SN) neurons is essential for voluntary movement control. An intrinsic pacemaker in DA SN neurons generates their tonic spontaneous activity, which triggers dopamine release. We show here, by combining multiplex and quantitative real-time single-cell RT- PCR with slice patch-clamp electrophysiology, that an A-type potassium channel mediated by Kv4.3 and KChip3 subunits has a key role in pacemaker control. The number of active A-type potassium channels is not only tightly associated with the pacemaker frequency of individual DA SN neurons, but is also highly correlated with their number of Kv4.3L (long splice variant) and KChip3.1 (long splice variant) mRNA molecules. Consequently, the variation of Kv4alpha and Kv4beta subunit transcript numbers is sufficient to explain the full spectrum of spontaneous pacemaker frequencies in identified DA SN neurons. This linear coupling between Kv4alpha as well as Kv4beta mRNA abundance, A-type channel density and pacemaker frequency suggests a surprisingly simple molecular mechanism for how DA SN neurons tune their variable firing rates by transcriptional control of ion channel genes.
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Affiliation(s)
- Birgit Liss
- Medical Research Council, Anatomical Neuropharmacology Unit, Department of Pharmacology, Oxford University, Oxford OX1 3TH, UK and Centre for Molecular Neurobiology, 20246 Hamburg, Germany
Corresponding authors e-mail: or
| | | | | | | | | | - Jochen Roeper
- Medical Research Council, Anatomical Neuropharmacology Unit, Department of Pharmacology, Oxford University, Oxford OX1 3TH, UK and Centre for Molecular Neurobiology, 20246 Hamburg, Germany
Corresponding authors e-mail: or
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Abstract
The development of functional genomic resources is essential to understand and utilize information generated from genome sequencing projects. Central to the development of this technology is the creation of high-quality cDNA resources and improved technologies for analyzing coding and noncoding mRNA sequences. The isolation and mapping of cDNAs is an entrée to characterizing the information that is of significant biological relevance in the genome of an organism. However, a bottleneck is often encountered when attempting to bring to full-length (or at least full-coding) a number of incomplete cDNAs in parallel, since this involves the nonsystematic, time consuming, and labor-intensive iterative screening of a number of cDNA libraries of variable quality and/or directed strategies to process individual clones (e.g., 5' rapid amplification of cDNA ends). Here, we review the current state of the art in cDNA library generation, as well as present an analysis of the different steps involved in cDNA library generation.
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Affiliation(s)
- M Das
- Department of Biochemistry, McGill Cancer Center, McGill University, Montreal, Quebec, Canada H3G 1Y6
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38
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Abstract
After minus-strand strong-stop DNA (-sssDNA) is synthesized, the RNA template is degraded by the RNase H activity of the reverse transcriptase (RT), generating a single-stranded DNA. The 3' end of -sssDNA from HIV-1 can form a hairpin; this hairpin will self-prime in vitro. We previously used a model substrate, -R ssDNA, which corresponds to the 3' end of the -sssDNA of HIV-1, to show that the self-priming of this model substrate could be prevented by annealing a 17-nt-long DNA oligonucleotide to the 3' end of -R ssDNA in the presence of HIV-1 nucleocapsid (NC) protein. Similar model substrates were prepared for HIV-2 and HTLV-1; the R regions of these two viruses are longer and form more complex structures than the R region of the HIV-1 genome. However, the size of the R region and the complexity of the secondary structures they can form do not affect self-priming or its prevention. The efficiency of the self-priming is related to the relative stabilities of the conformations of -R ssDNA that can and cannot induce self-priming. For the three viruses (HIV-1, HIV-2, and HTLV-1), the size of the DNA oligonucleotide needed to block self-priming in the presence of NC is similar to the expected size of the piece of RNA left after degradation of the RNA template during reverse transcription. We also found that when the 3' end of -R ssDNA is annealed to a complementary DNA oligonucleotide, it is a good substrate for efficient nonspecific strand transfer to other single-stranded DNA molecules.
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Affiliation(s)
- M P Golinelli
- HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland 21702-1201, USA
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Rajeevan MS, Vernon SD, Taysavang N, Unger ER. Validation of array-based gene expression profiles by real-time (kinetic) RT-PCR. J Mol Diagn 2001; 3:26-31. [PMID: 11227069 PMCID: PMC1907344 DOI: 10.1016/s1525-1578(10)60646-0] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2000] [Indexed: 11/24/2022] Open
Abstract
We evaluated real-time (kinetic) reverse transcription-polymerase chain reaction (RT-PCR) to validate differentially expressed genes identified by DNA arrays. Gene expression of two keratinocyte subclones differing in the physical state of human papillomavirus (episomal or integrated) was used as a model system. High-density filter arrays identified 444 of 588 genes as either negative or expressed with less than twofold difference, and the other 144 genes as expressed uniquely or with more than twofold difference between the two subclones. Real-time RT-PCR used LightCycler-based SYBR Green I dye detection and melting curve analysis to validate the relative change in gene expression. Real-time RT-PCR confirmed the change in expression of 17 of 24 (71%) genes identified by high-density filter arrays. Genes with strong hybridization signals and at least twofold difference were likely to be validated by real-time RT-PCR. This data suggests that (i) both hybridization intensity and the level of differential expression determine the likelihood of validating high-density filter array results and (ii) genes identified by DNA arrays with a two- to fourfold difference in expression cannot be eliminated as false nor be accepted as true without validation. Real-time RT-PCR based on LightCycler technology is well-suited to validate DNA array results because it is quantitative, rapid, and requires 1000-fold less RNA than conventional assays.
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Affiliation(s)
- M S Rajeevan
- Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, GA 30333, USA.
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Abstract
In the continuing search for a full-length cDNA cloning method, there is no clear winner. Perfecting these techniques may require the re-engineering of reverse transcriptase. There now exist two reasonably linear methods for deriving expression signatures from small amounts of biological material, but advances in serial analysis of gene expression provide a quantitative, if expensive, alternative to these methods.
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Affiliation(s)
- S Bashiardes
- Department of Genetics, Washington University School of Medicine, Campus Box 8232, 4566 Scott Avenue, St Louis, Missouri 63110-1093, USA
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Rajeevan MS, Dimulescu IM, Unger ER, Vernon SD. Chemiluminescent analysis of gene expression on high-density filter arrays. J Histochem Cytochem 1999; 47:337-42. [PMID: 10026235 DOI: 10.1177/002215549904700307] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have optimized conditions for the chemiluminescent analysis of gene expression using high-density filter arrays (HDFAs). High sensitivity and specificity were achieved by optimizing cDNA probe synthesis, hybridization, and detection parameters. The chemiluminescent expression profile reflected expected differences in the transcripts isolated from different sources (placenta and keratinocytes). We estimated the detection limit for low-abundance message to be 1-15 transcripts per cell, a sensitivity rivaling that reported for microarray formats and exceeding that reported for autoradiographic HDFAs. The method allows for short exposure times and reuse of probe. It should be equally applicable to techniques such as differential screening of cDNA libraries and differential display PCR.
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Affiliation(s)
- M S Rajeevan
- Division of Viral and Rickettsial Disease, Centers for Infectious Disease, Centers for Disease Control and Prevention, US Department of Health and Human Services, Atlanta, Georgia, USA
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