1
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Khaing EP, Eaton-Rye JJ. Lys264 of the D2 Protein Performs a Dual Role in Photosystem II Modifying Assembly and Electron Transfer through the Quinone-Iron Acceptor Complex. Biochemistry 2023; 62:2738-2750. [PMID: 37606628 DOI: 10.1021/acs.biochem.3c00240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Bicarbonate (HCO3-) binding regulates electron flow between the primary (QA) and secondary (QB) plastoquinone electron acceptors of Photosystem II (PS II). Lys264 of the D2 subunit of PS II contributes to a hydrogen-bond network that stabilizes HCO3- ligation to the non-heme iron in the QA-Fe-QB complex. Using the cyanobacterium Synechocystis sp. PCC 6803, alanine and glutamate were introduced to create the K264A and K264E mutants. Photoautotrophic growth was slowed in K264E cells but not in the K264A strain. Both mutants accumulated an unassembled CP43 precomplex as well as the CP43-lacking RC47 assembly intermediate, indicating weakened binding of the CP43 precomplex to RC47. Assembly was impeded more in K264E cells than in the K264A strain, but K264A cells were more susceptible to high-light-induced photodamage when assayed using PS II-specific electron acceptors. Furthermore, an impaired repair mechanism was observed in the K264A mutant in protein labeling experiments. Unexpectedly, unlike the K264A strain, the K264E mutant displayed inhibited oxygen evolution following high-light exposure when HCO3- was added to support whole chain electron transport. In both mutants, the decay of chlorophyll fluorescence was slowed, indicating impaired electron transfer between QA and QB. Furthermore, the fluorescence decay kinetics in the K264E strain were insensitive to addition of either formate or HCO3-, whereas HCO3--reversible formate-induced inhibition in the K264A mutant was observed. Exchange of plastoquinol with the membrane plastoquinone pool at the QB-binding site was also retarded in both mutants. Hence, D2-Lys264 possesses key roles in both assembly and activity of PS II.
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Affiliation(s)
- Ei Phyo Khaing
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
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2
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A critical path to producing high quality, reproducible data from quantitative western blot experiments. Sci Rep 2022; 12:17599. [PMID: 36266411 PMCID: PMC9585080 DOI: 10.1038/s41598-022-22294-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 10/12/2022] [Indexed: 01/13/2023] Open
Abstract
Western blotting experiments were initially performed to detect a target protein in a complex biological sample and more recently, to measure relative protein abundance. Chemiluminescence coupled with film-based detection was traditionally the gold standard for western blotting but accurate and reproducible quantification has been a major challenge from this methodology. The development of sensitive, camera-based detection technologies coupled with an updated technical approach permits the production of reproducible, quantitative data. Fluorescence reagent and detection solutions are the latest innovation in western blotting but there remains questions and debate concerning their relative sensitivity and dynamic range versus chemiluminescence. A methodology to optimize and produce excellent, quantitative western blot results with rigorous data analysis from membranes probed with both fluorescent and chemiluminescent antibodies is described. The data reveal when and how to apply these detection methods to achieve reproducible data with a stepwise approach to data processing for quantitative analysis.
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3
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An Optimized Comparative Proteomic Approach as a Tool in Neurodegenerative Disease Research. Cells 2022; 11:cells11172653. [PMID: 36078061 PMCID: PMC9454658 DOI: 10.3390/cells11172653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/16/2022] [Accepted: 08/22/2022] [Indexed: 11/25/2022] Open
Abstract
Recent advances in proteomic technologies now allow unparalleled assessment of the molecular composition of a wide range of sample types. However, the application of such technologies and techniques should not be undertaken lightly. Here, we describe why the design of a proteomics experiment itself is only the first step in yielding high-quality, translatable results. Indeed, the effectiveness and/or impact of the majority of contemporary proteomics screens are hindered not by commonly considered technical limitations such as low proteome coverage but rather by insufficient analyses. Proteomic experimentation requires a careful methodological selection to account for variables from sample collection, through to database searches for peptide identification to standardised post-mass spectrometry options directed analysis workflow, which should be adjusted for each study, from determining when and how to filter proteomic data to choosing holistic versus trend-wise analyses for biologically relevant patterns. Finally, we highlight and discuss the difficulties inherent in the modelling and study of the majority of progressive neurodegenerative conditions. We provide evidence (in the context of neurodegenerative research) for the benefit of undertaking a comparative approach through the application of the above considerations in the alignment of publicly available pre-existing data sets to identify potential novel regulators of neuronal stability.
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4
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Khaing EP, Zhong V, Kodru S, Vass I, Eaton-Rye JJ. Tyr244 of the D2 Protein Is Required for Correct Assembly and Operation of the Quinone-Iron-Bicarbonate Acceptor Complex of Photosystem II. Biochemistry 2022; 61:1298-1312. [PMID: 35699437 DOI: 10.1021/acs.biochem.2c00164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two plastoquinone electron acceptors, QA and QB, are present in Photosystem II (PS II) with their binding sites formed by the D2 and D1 proteins, respectively. A hexacoordinate non-heme iron is bound between QA and QB by D2 and D1, each providing two histidine ligands, and a bicarbonate that is stabilized via hydrogen bonds with D2-Tyr244 and D1-Tyr246. Both tyrosines and bicarbonate are conserved in oxygenic photosynthetic organisms but absent from the corresponding quinone-iron electron acceptor complex of anoxygenic photosynthetic bacteria. We investigated the role of D2-Tyr244 by introducing mutations in the cyanobacterium Synechocystis sp. PCC 6803. Alanine, histidine, and phenylalanine substitutions were introduced creating the Y244A, Y244H, and Y244F mutants. Electron transfer between QA and QB was impaired, the back-reaction with the S2 state of the oxygen-evolving complex was modified, and PS II assembly was disrupted, with the Y244A strain being more affected than the Y244F and Y244H mutants. The strains were also highly susceptible to photodamage in the presence of PS II-specific electron acceptors. Thermoluminescence and chlorophyll a fluorescence decay measurements indicated that the redox potential of the QA/QA- couple became more positive in the Y244F and Y244H mutants, consistent with bicarbonate binding being impacted. The replacement of Tyr244 by alanine also led to an insertion of two amino acid repeats from Gln239 to Ala249 within the DE loop of D2, resulting in an inactive PS II complex that lacked PS II-specific variable fluorescence. The 66 bp insertion giving rise to the inserted amino acids therefore created an obligate photoheterotrophic mutant.
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Affiliation(s)
- Ei Phyo Khaing
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Victor Zhong
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Sandeesha Kodru
- Biological Research Center, Institute of Plant Biology, Szeged 6726, Hungary
| | - Imre Vass
- Biological Research Center, Institute of Plant Biology, Szeged 6726, Hungary
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
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5
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Tiwari NK, Sathyanesan M, Kumar V, Newton SS. A Comparative Analysis of Erythropoietin and Carbamoylated Erythropoietin Proteome Profiles. Life (Basel) 2021; 11:life11040359. [PMID: 33921564 PMCID: PMC8073529 DOI: 10.3390/life11040359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/08/2021] [Accepted: 04/14/2021] [Indexed: 01/24/2023] Open
Abstract
In recent years, erythropoietin (EPO) has emerged as a useful neuroprotective and neurotrophic molecule that produces antidepressant and cognitive-enhancing effects in psychiatric disorders. However, EPO robustly induces erythropoiesis and elevates red blood cell counts. Chronic administration is therefore likely to increase blood viscosity and produce adverse effects in non-anemic populations. Carbamoylated erythropoietin (CEPO), a chemically engineered modification of EPO, is non-erythropoietic but retains the neurotrophic and neurotrophic activity of EPO. Blood profile analysis after EPO and CEPO administration showed that CEPO has no effect on red blood cell or platelet counts. We conducted an unbiased, quantitative, mass spectrometry-based proteomics study to comparatively investigate EPO and CEPO-induced protein profiles in neuronal phenotype PC12 cells. Bioinformatics enrichment analysis of the protein expression profiles revealed the upregulation of protein functions related to memory formation such as synaptic plasticity, long term potentiation (LTP), neurotransmitter transport, synaptic vesicle priming, and dendritic spine development. The regulated proteins, with roles in LTP and synaptic plasticity, include calcium/calmodulin-dependent protein kinase type 1 (Camk1), Synaptosomal-Associated Protein, 25 kDa (SNAP-25), Sectretogranin-1 (Chgb), Cortactin (Cttn), Elongation initiation factor 3a (Eif3a) and 60S acidic ribosomal protein P2 (Rplp2). We examined the expression of a subset of regulated proteins, Cortactin, Grb2 and Pleiotrophin, by immunofluorescence analysis in the rat brain. Grb2 was increased in the dentate gyrus by EPO and CEPO. Cortactin was induced by CEPO in the molecular layer, and pleiotrophin was increased in the vasculature by EPO. The results of our study shed light on potential mechanisms whereby EPO and CEPO produce cognitive-enhancing effects in clinical and preclinical studies.
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Affiliation(s)
- Neeraj K. Tiwari
- Pediatrics and Rare Disease Group, Sanford Research, Sioux Falls, SD 57104, USA;
| | - Monica Sathyanesan
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA;
| | - Vikas Kumar
- Mass Spectrometry and Proteomics Core Facility, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Samuel S. Newton
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA;
- Correspondence: ; Tel.: +1-605-658-6313
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6
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Li C, Kang L, Fan K, Ferreira CA, Becker KV, Huo N, Liu H, Yang Y, Engle JW, Wang R, Xu X, Jiang D, Cai W. ImmunoPET of CD146 in Orthotopic and Metastatic Breast Cancer Models. Bioconjug Chem 2021; 32:1306-1314. [PMID: 33475350 DOI: 10.1021/acs.bioconjchem.0c00649] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The overexpression of CD146 in breast cancer is considered a hallmark of tumor progression and metastasis, particularly in triple negative breast cancer. Aimed at imaging differential CD146 expressions in breast cancer, a noninvasive method for predictive prognosis and diagnosis was investigated using a 64Cu-labeled CD146-specific monoclonal antibody, YY146. CD146 expression was screened in human breast cancer cell lines using Western blotting. Binding ability was evaluated using flow cytometry and immunofluorescent staining. YY146 was conjugated with 1,4,7-triazacyclononane-triacetic acid (NOTA) and radiolabeled with 64Cu following standard procedures. Serial PET or PET/CT imaging was performed in orthotopic and metastatic breast cancer tumor models. Biodistribution was performed after the final time point of imaging. Finally, tissue immunofluorescent staining and hematoxylin and eosin (H&E) staining were performed on tumor tissues. The MDA-MB-435 cell line showed the highest CD146 expression level, whereas MCF-7 had the lowest level at the cellular level. ImmunoPET showed that MDA-MB-435 orthotopic tumors had high and clear radioactive accumulation after the administration of 64Cu-NOTA-YY146. The tumor uptake of 64Cu-NOTA-YY146 in MDA-MB-435 was significantly higher than that in MCF-7 and nonspecific IgG control groups (P < 0.01). Biodistribution verified the PET imaging results. For metastatic models, 64Cu-NOTA-YY146 allowed for the visualization of high radioactivity accumulation in metastatic MDA-MB-435 tumors, which was confirmed by ex vivo biodistribution of lung tissues. H&E staining proved the successful building of metastatic tumor models. Immunofluorescent staining verified the differential expression of CD146 in orthotopic tumors. Therefore, 64Cu-NOTA-YY146 could be used as an immunoPET probe to visualize CD146 in the breast cancer model and is potentially useful for cancer diagnosis, prognosis prediction, and monitoring therapeutic response.
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Affiliation(s)
- Cuicui Li
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, China 100034
| | - Lei Kang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, China 100034.,Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Kevin Fan
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Carolina A Ferreira
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Kaelyn V Becker
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Nan Huo
- Department of Medical Molecular Biology, Beijing Institute of Biotechnology, Beijing, China 100850
| | - Hanxiao Liu
- Department of Oncology, Harbin Medical University Affiliated Cancer Hospital, Harbin, China 150081
| | - Yunan Yang
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Jonathan W Engle
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Rongfu Wang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, China 100034
| | - Xiaojie Xu
- Department of Medical Molecular Biology, Beijing Institute of Biotechnology, Beijing, China 100850
| | - Dawei Jiang
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430022
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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7
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Petrillo T, Ayombil F, Van't Veer C, Camire RM. Regulation of factor V and factor V-short by TFPIα: Relationship between B-domain proteolysis and binding. J Biol Chem 2021; 296:100234. [PMID: 33376137 PMCID: PMC7948760 DOI: 10.1074/jbc.ra120.016341] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/17/2020] [Accepted: 12/29/2020] [Indexed: 12/25/2022] Open
Abstract
Coagulation factor V (FV) plays an anticoagulant role but serves as a procoagulant cofactor in the prothrombinase complex once activated to FVa. At the heart of these opposing effects is the proteolytic removal of its central B-domain, including conserved functional landmarks (basic region, BR; 963–1008 and acidic region 2, AR2; 1493–1537) that enforce the inactive FV procofactor state. Tissue factor pathway inhibitor α (TFPIα) has been associated with FV as well as FV-short, a physiologically relevant isoform with a shortened B-domain missing the BR. However, it is unclear which forms of FV are physiologic ligands for TFPIα. Here, we characterize the binding and regulation of FV and FV-short by TFPIα via its positively charged C-terminus (TFPIα-BR) and examine how bond cleavage in the B-domain influences these interactions. We show that FV-short is constitutively active and functions in prothrombinase like FVa. Unlike FVa, FV-short binds with high affinity (Kd ∼1 nM) to TFPIα-BR, which blocks procoagulant function unless FV-short is cleaved at Arg1545, removing AR2. Importantly, we do not observe FV binding (μM detection limit) to TFPIα. However, cleavage at Arg709 and Arg1018 displaces the FV BR, exposing AR2 and allowing TFPIα to bind via its BR. We conclude that for full-length FV, the detachment of FV BR from AR2 is necessary and sufficient for TFPIα binding and regulation. Our findings pinpoint key forms of FV, including FV-short, that act as physiologic ligands for TFPIα and establish a mechanistic framework for assessing the functional connection between these proteins.
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Affiliation(s)
- Teodolinda Petrillo
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Francis Ayombil
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Cornelis Van't Veer
- Center of Experimental and Molecular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Rodney M Camire
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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8
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Diller T, Thompson J, Steer B. Biological validation of a novel process and product for quantitating western blots. J Biotechnol 2020; 326:52-60. [PMID: 33373626 DOI: 10.1016/j.jbiotec.2020.12.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/14/2020] [Accepted: 12/17/2020] [Indexed: 01/03/2023]
Abstract
Protein normalization of western blots has relied upon housekeeping proteins which exhibit signal saturation and varied cellular expression level variations. These issues can produce spurious results leading to erroneous conclusions. A superior method to protein normalization using housekeeping proteins is Total Protein Normalization, a method now recognized as the gold standard for quantitative westerns. Total Protein Normalization requires that all proteins on a membrane be stained or labeled uniformly, imaged, and then analyzed for total protein. It is important that such a normalization process not interfere with typical immunodetection methods, fits within existing western workflows, and exhibits a linear relationship of signal intensity to protein load under all experimental conditions. Here we report that we developed a new reagent enabling Total Protein Normalization, and we demonstrate its superior protein normalization capabilities through analysis of target proteins in different cell backgrounds. These data illustrate how housekeeping proteins exhibit signal saturation, yield erroneous normalization data, and display sample-to-sample variations averaging 48.2 % overall. Signal intensities obtained using our new method show a linear relationship to protein sample load, thus providing accurate protein normalization with an overall average variation of 7.7 %.
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Affiliation(s)
- Thomas Diller
- Thermo Fisher Scientific, 5781 Van Allen Way, Carlsbad, CA, 92008-7321, United States.
| | - Jordan Thompson
- Thermo Fisher Scientific, 5781 Van Allen Way, Carlsbad, CA, 92008-7321, United States
| | - Brian Steer
- Thermo Fisher Scientific, 5781 Van Allen Way, Carlsbad, CA, 92008-7321, United States
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9
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Pavlović N, Calitz C, Thanapirom K, Mazza G, Rombouts K, Gerwins P, Heindryckx F. Inhibiting IRE1α-endonuclease activity decreases tumor burden in a mouse model for hepatocellular carcinoma. eLife 2020; 9:e55865. [PMID: 33103995 PMCID: PMC7661042 DOI: 10.7554/elife.55865] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 10/26/2020] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a liver tumor that usually arises in patients with cirrhosis. Hepatic stellate cells are key players in the progression of HCC, as they create a fibrotic micro-environment and produce growth factors and cytokines that enhance tumor cell proliferation and migration. We assessed the role of endoplasmic reticulum (ER) stress in the cross-talk between stellate cells and HCC cells. Mice with a fibrotic HCC were treated with the IRE1α-inhibitor 4μ8C, which reduced tumor burden and collagen deposition. By co-culturing HCC-cells with stellate cells, we found that HCC-cells activate IREα in stellate cells, thereby contributing to their activation. Inhibiting IRE1α blocked stellate cell activation, which then decreased proliferation and migration of tumor cells in different in vitro 2D and 3D co-cultures. In addition, we also observed cell-line-specific direct effects of inhibiting IRE1α in tumor cells.
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Affiliation(s)
- Nataša Pavlović
- Department of Medical Cell Biology, Uppsala UniversityUppsalaSweden
| | - Carlemi Calitz
- Department of Medical Cell Biology, Uppsala UniversityUppsalaSweden
| | - Kess Thanapirom
- Regenerative Medicine & Fibrosis Group, Institute for Liver and Digestive Health, University College LondonLondonUnited Kingdom
| | - Guiseppe Mazza
- Regenerative Medicine & Fibrosis Group, Institute for Liver and Digestive Health, University College LondonLondonUnited Kingdom
| | - Krista Rombouts
- Regenerative Medicine & Fibrosis Group, Institute for Liver and Digestive Health, University College LondonLondonUnited Kingdom
| | - Pär Gerwins
- Department of Medical Cell Biology, Uppsala UniversityUppsalaSweden
- Department of Radiology, Uppsala University HospitalUppsalaSweden
| | - Femke Heindryckx
- Department of Medical Cell Biology, Uppsala UniversityUppsalaSweden
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10
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Yan W, Fan L, Li J, Wang Y, Han H, Tan F, Zhang P. Bimodal size distribution immuno-quantum dots for fluorescent western blotting assay with high sensitivity and extended dynamic range. Mikrochim Acta 2020; 187:598. [PMID: 33034772 DOI: 10.1007/s00604-020-04578-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/29/2020] [Indexed: 11/25/2022]
Abstract
A highly sensitive quantum dot (QD)-based western blot assay with extended dynamic range was developed. Bimodal size distribution QD (BQ) immunoprobes composed of small size single QD (7.3 nm) and big size QD nanobead (QB) (82.9 nm) were employed for fluorescent western blot immunoassay on a membrane. Small size QD immunoprobes contributed to wider dynamic range of assay, while big size QB immunoprobes provided higher detection sensitivity. This BQ-based western blot assay can achieve a wide dynamic range (from 7.8 to 4000 ng IgG) and is nearly as sensitive as commercial available ultrasensitive chemiluminescent methods, just using a simple gel imager with UV light (365 nm) excitation and red light filter (610 nm). The fluorescent signals of BQ western blot were stable for 10 min, while chemiluminescent signals faded after 1 min. Moreover, this BQ immunoprobe was utilized for the detection of housekeeping protein and specific target proteins in complex cell lysate samples. The limit of detection of housekeeping protein is 0.25 μg of cell lysate, and the signal intensities were proportional to loading protein amount in a wide range from 0.61 to 80 μg. We believe that this new strategy of bimodal size distribution nanoparticles can also be expanded for other functional nanoparticle-based biological assays to improve the sensitivity and extend the dynamic range. Graphical abstract.
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Affiliation(s)
- Wannian Yan
- Department of Central Laboratory, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Lingzhi Fan
- Department of Central Laboratory, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China
| | - Jin Li
- Shandong Zhifu Hospital, Yantai, 26400, Shandong, China
| | - Yijiang Wang
- Department of Periodontology, School & Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, Shanghai, 200072, China
| | - Huanxing Han
- Department of Pharmacy, Changzheng Hospital, The Second Military Medical University, Shanghai, 200433, China
- Aliex Technology Group Co., Ltd, No. 152, Lane 468, North Hengshahe Road, Shanghai, China
| | - Fei Tan
- Department of Central Laboratory, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China.
| | - Pengfei Zhang
- Department of Central Laboratory, Shanghai Skin Disease Hospital, Tongji University School of Medicine, Shanghai, 200443, China.
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11
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Nelvagal HR, Hurtado ML, Eaton SL, Kline RA, Lamont DJ, Sands MS, Wishart TM, Cooper JD. Comparative proteomic profiling reveals mechanisms for early spinal cord vulnerability in CLN1 disease. Sci Rep 2020; 10:15157. [PMID: 32938982 PMCID: PMC7495486 DOI: 10.1038/s41598-020-72075-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 08/26/2020] [Indexed: 01/11/2023] Open
Abstract
CLN1 disease is a fatal inherited neurodegenerative lysosomal storage disease of early childhood, caused by mutations in the CLN1 gene, which encodes the enzyme Palmitoyl protein thioesterase-1 (PPT-1). We recently found significant spinal pathology in Ppt1-deficient (Ppt1−/−) mice and human CLN1 disease that contributes to clinical outcome and precedes the onset of brain pathology. Here, we quantified this spinal pathology at 3 and 7 months of age revealing significant and progressive glial activation and vulnerability of spinal interneurons. Tandem mass tagged proteomic analysis of the spinal cord of Ppt1−/−and control mice at these timepoints revealed a significant neuroimmune response and changes in mitochondrial function, cell-signalling pathways and developmental processes. Comparing proteomic changes in the spinal cord and cortex at 3 months revealed many similarly affected processes, except the inflammatory response. These proteomic and pathological data from this largely unexplored region of the CNS may help explain the limited success of previous brain-directed therapies. These data also fundamentally change our understanding of the progressive, site-specific nature of CLN1 disease pathogenesis, and highlight the importance of the neuroimmune response. This should greatly impact our approach to the timing and targeting of future therapeutic trials for this and similar disorders.
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Affiliation(s)
- Hemanth R Nelvagal
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Maica Llavero Hurtado
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Samantha L Eaton
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Rachel A Kline
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Douglas J Lamont
- FingerPrints Proteomics Facility, College of Life Sciences, University of Dundee, Dundee, UK
| | - Mark S Sands
- Department of Genetics, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA.,Department of Medicine, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA
| | - Thomas M Wishart
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Jonathan D Cooper
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA. .,Department of Genetics, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA. .,Department of Neurology, Washington University in St Louis, School of Medicine, 660 S Euclid Ave, St Louis, MO, 63110, USA. .,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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12
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Hamza GM, Bergo VB, Mamaev S, Wojchowski DM, Toran P, Worsfold CR, Castaldi MP, Silva JC. Affinity-Bead Assisted Mass Spectrometry (Affi-BAMS): A Multiplexed Microarray Platform for Targeted Proteomics. Int J Mol Sci 2020; 21:E2016. [PMID: 32188029 PMCID: PMC7139916 DOI: 10.3390/ijms21062016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 02/06/2023] Open
Abstract
The ability to quantitatively probe diverse panels of proteins and their post-translational modifications (PTMs) across multiple samples would aid a broad spectrum of biological, biochemical and pharmacological studies. We report a novel, microarray analytical technology that combines immuno-affinity capture with Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS), which is capable of supporting highly multiplexed, targeted proteomic assays. Termed "Affinity-Bead Assisted Mass Spectrometry" (Affi-BAMS), this LC-free technology enables development of highly specific and customizable assay panels for simultaneous profiling of multiple proteins and PTMs. While affinity beads have been used previously in combination with MS, the Affi-BAMS workflow uses enrichment on a single bead that contains one type of antibody, generally capturing a single analyte (protein or PTM) while having enough binding capacity to enable quantification within approximately 3 orders of magnitude. The multiplexing capability is achieved by combining Affi-BAMS beads with different protein specificities. To enable screening of bead-captured analytes by MS, we further developed a novel method of performing spatially localized elution of targets from individual beads arrayed on a microscope slide. The resulting arrays of micro spots contain highly concentrated analytes localized within 0.5 mm diameter spots that can be directly measured using MALDI MS. While both intact proteins and protein fragments can be monitored by Affi-BAMS, we initially focused on applying this technology for bottom-up proteomics to enable screening of hundreds of samples per day by combining the robust magnetic bead-based workflow with the high throughput nature of MALDI MS acquisition. To demonstrate the variety of applications and robustness of Affi-BAMS, several studies are presented that focus on the response of 4EBP1, RPS6, ERK1/ERK2, mTOR, Histone H3 and C-MET to stimuli including rapamycin, H2O2, EPO, SU11274, Staurosporine and Vorinostat.
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Affiliation(s)
- Ghaith M. Hamza
- Discovery Sciences, BioPharmaceutical R&D, AstraZeneca, Boston, MA 02451, USA; (G.M.H.); (M.P.C.)
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA; (D.M.W.); (P.T.)
| | - Vladislav B. Bergo
- Adeptrix Corporation, Beverly, MA 01915, USA; (V.B.B.); (S.M.); (C.R.W.)
| | - Sergey Mamaev
- Adeptrix Corporation, Beverly, MA 01915, USA; (V.B.B.); (S.M.); (C.R.W.)
| | - Don M. Wojchowski
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA; (D.M.W.); (P.T.)
| | - Paul Toran
- Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA; (D.M.W.); (P.T.)
| | | | - M. Paola Castaldi
- Discovery Sciences, BioPharmaceutical R&D, AstraZeneca, Boston, MA 02451, USA; (G.M.H.); (M.P.C.)
| | - Jeffrey C. Silva
- Adeptrix Corporation, Beverly, MA 01915, USA; (V.B.B.); (S.M.); (C.R.W.)
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13
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He L, Binari R, Huang J, Falo-Sanjuan J, Perrimon N. In vivo study of gene expression with an enhanced dual-color fluorescent transcriptional timer. eLife 2019; 8:46181. [PMID: 31140975 PMCID: PMC6660218 DOI: 10.7554/elife.46181] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/28/2019] [Indexed: 12/28/2022] Open
Abstract
Fluorescent transcriptional reporters are widely used as signaling reporters and biomarkers to monitor pathway activities and determine cell type identities. However, a large amount of dynamic information is lost due to the long half-life of the fluorescent proteins. To better detect dynamics, fluorescent transcriptional reporters can be destabilized to shorten their half-lives. However, applications of this approach in vivo are limited due to significant reduction of signal intensities. To overcome this limitation, we enhanced translation of a destabilized fluorescent protein and demonstrate the advantages of this approach by characterizing spatio-temporal changes of transcriptional activities in Drosophila. In addition, by combining a fast-folding destabilized fluorescent protein and a slow-folding long-lived fluorescent protein, we generated a dual-color transcriptional timer that provides spatio-temporal information about signaling pathway activities. Finally, we demonstrate the use of this transcriptional timer to identify new genes with dynamic expression patterns.
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Affiliation(s)
- Li He
- Department of Genetics, Harvard Medical School, Boston, United States
| | - Richard Binari
- Department of Genetics, Harvard Medical School, Boston, United States.,Howard Hughes Medical Institute, Boston, United States
| | - Jiuhong Huang
- International Academy of Targeted Therapeutics and Innovation, Chongqing University of Arts and Sciences, Chongqing, China
| | | | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, United States.,Howard Hughes Medical Institute, Boston, United States
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14
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Abstract
Identification and degradation of misfolded proteins by the ubiquitin-proteasome system (UPS) is crucial for maintaining proteostasis, but only a handful of UPS components have been linked to the recognition of specific substrates. Studies in Saccharomyces cerevisiae using systematic perturbation of nonessential genes have uncovered UPS components that recognize and ubiquitylate model substrates of the UPS; however, similar analyses in metazoans have been limited. In this chapter, we describe methods for using CRISPR/Cas9 technology combined with genome-wide high complexity single guide (sgRNA) libraries and a transcriptional shutoff strategy for phenotypic selection based on kinetic measurements of protein turnover to identify the genes required to degrade model clients of the mammalian ER-associated degradation system. We also discuss considerations for screen design, execution, and interpretation.
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Affiliation(s)
- Dara E Leto
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Ron R Kopito
- Department of Biology, Stanford University, Stanford, CA, United States.
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15
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Schnell FJ, Frank D, Fletcher S, Johnsen RD, Wilton SD. Challenges of Interpreting Dystrophin Content by Western Blot. ACTA ACUST UNITED AC 2019. [DOI: 10.17925/usn.2019.15.1.40] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Duchenne muscular dystrophy community has recently seen the first approved therapy for the restoration of dystrophin, based on its ability to increase levels of dystrophin protein, as determined by western blot. The approval, along with the initiation of clinical trials evaluating other dystrophin-restoring therapies, highlights the importance of accurate dystrophin quantitation. Nonoptimized western blot methods can reflect inaccurate results, especially in the quantitation of low dystrophin levels. A few key changes to standards and data analysis parameters can result in a low level of dystrophin (<0.5% of a healthy biopsy) being inaccurately interpreted as >20% of the levels reported in healthy human muscle. A review of the dystrophin western blot data on Duchenne and Becker muscular dystrophy biopsies is conducted, along with a thorough investigation of methodologies to quantify dystrophin.
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16
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Cai X, Zheng Y, Speck NA. A Western Blotting Protocol for Small Numbers of Hematopoietic Stem Cells. J Vis Exp 2018. [PMID: 30199018 DOI: 10.3791/56855] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Hematopoietic stem cells (HSCs) are rare cells, with the mouse bone marrow containing only ~25,000 phenotypic long term repopulating HSCs. A Western blotting protocol was optimized and suitable for the analysis of small numbers of HSCs (500 - 15,000 cells). Phenotypic HSCs were purified, accurately counted, and directly lysed in Laemmli sample buffer. Lysates containing equal numbers of cells were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the blot was prepared and processed following standard Western blotting protocols. Using this protocol, 2,000 - 5,000 HSCs can be routinely analyzed, and in some cases data can be obtained from as few as 500 cells, compared to the 20,000 to 40,000 cells reported in most publications. This protocol should be generally applicable to other hematopoietic cells, and enables the routine analysis of small numbers of cells using standard laboratory procedures.
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Affiliation(s)
- Xiongwei Cai
- Division of Experimental Hematology, Cincinnati Children's Hospital Medical Center; Department of Cell and Developmental Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania; Department of Obstetrics and Gynecology, Southwest Hospital, Third Military Medical University
| | - Yi Zheng
- Division of Experimental Hematology, Cincinnati Children's Hospital Medical Center
| | - Nancy A Speck
- Department of Cell and Developmental Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania;
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17
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Koch RJ, Barrette AM, Stern AD, Hu B, Bouhaddou M, Azeloglu EU, Iyengar R, Birtwistle MR. Validating Antibodies for Quantitative Western Blot Measurements with Microwestern Array. Sci Rep 2018; 8:11329. [PMID: 30054510 PMCID: PMC6063895 DOI: 10.1038/s41598-018-29436-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 05/10/2018] [Indexed: 01/11/2023] Open
Abstract
Fluorescence-based western blots are quantitative in principal, but require determining linear range for each antibody. Here, we use microwestern array to rapidly evaluate suitable conditions for quantitative western blotting, with up to 192 antibody/dilution/replicate combinations on a single standard size gel with a seven-point, two-fold lysate dilution series (~100-fold range). Pilot experiments demonstrate a high proportion of investigated antibodies (17/24) are suitable for quantitative use; however this sample of antibodies is not yet comprehensive across companies, molecular weights, and other important antibody properties, so the ubiquity of this property cannot yet be determined. In some cases microwestern struggled with higher molecular weight membrane proteins, so the technique may not be uniformly applicable to all validation tasks. Linear range for all validated antibodies is at least 8-fold, and up to two orders of magnitude. Phospho-specific and total antibodies do not have discernable trend differences in linear range or limit of detection. Total antibodies generally required higher working concentrations, but more comprehensive antibody panels are required to better establish whether this trend is general or not. Importantly, we demonstrate that results from microwestern analyses scale to normal "macro" western for a subset of antibodies.
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Affiliation(s)
- Rick J Koch
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Anne Marie Barrette
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Alan D Stern
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Bin Hu
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Mehdi Bouhaddou
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Evren U Azeloglu
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Ravi Iyengar
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Marc R Birtwistle
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC, 29634, USA.
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18
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Maxwell GK, Szunyogova E, Shorrock HK, Gillingwater TH, Parson SH. Developmental and degenerative cardiac defects in the Taiwanese mouse model of severe spinal muscular atrophy. J Anat 2018; 232:965-978. [PMID: 29473159 PMCID: PMC5978979 DOI: 10.1111/joa.12793] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 12/31/2022] Open
Abstract
Spinal muscular atrophy (SMA), an autosomal recessive disease caused by a decrease in levels of the survival motor neuron (SMN) protein, is the most common genetic cause of infant mortality. Although neuromuscular pathology is the most severe feature of SMA, other organs and tissues, including the heart, are also known to be affected in both patients and animal models. Here, we provide new insights into changes occurring in the heart, predominantly at pre- and early symptomatic ages, in the Taiwanese mouse model of severe SMA. Thinning of the interventricular septum and dilation of the ventricles occurred at pre- and early symptomatic ages. However, the left ventricular wall was significantly thinner in SMA mice from birth, occurring prior to any overt neuromuscular symptoms. Alterations in collagen IV protein from birth indicated changes to the basement membrane and contributed to the abnormal arrangement of cardiomyocytes in SMA hearts. This raises the possibility that developmental defects, occurring prenatally, may contribute to cardiac pathology in SMA. In addition, cardiomyocytes in SMA hearts exhibited oxidative stress at pre-symptomatic ages and increased apoptosis during early symptomatic stages of disease. Heart microvasculature was similarly decreased at an early symptomatic age, likely contributing to the oxidative stress and apoptosis phenotypes observed. Finally, an increased incidence of blood retention in SMA hearts post-fixation suggests the likelihood of functional defects, resulting in blood pooling. These pathologies mirror dilated cardiomyopathy, with clear consequences for heart function that would likely contribute to potential heart failure. Our findings add significant additional experimental evidence in support of the requirement to develop systemic therapies for SMA capable of treating non-neuromuscular pathologies.
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Affiliation(s)
| | - Eva Szunyogova
- Institute for Medical ScienceUniversity of AberdeenAberdeenUK
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
| | - Hannah K. Shorrock
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
- Edinburgh Medical School: Biomedical SciencesUniversity of EdinburghEdinburghUK
| | - Thomas H. Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
- Edinburgh Medical School: Biomedical SciencesUniversity of EdinburghEdinburghUK
| | - Simon H. Parson
- Institute for Medical ScienceUniversity of AberdeenAberdeenUK
- Euan MacDonald Centre for Motor Neurone Disease ResearchUniversity of EdinburghEdinburghUK
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19
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Reactive oxygen species stress increases accumulation of tyrosyl-DNA phsosphodiesterase 1 within mitochondria. Sci Rep 2018. [PMID: 29523818 PMCID: PMC5844879 DOI: 10.1038/s41598-018-22547-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a nuclear and mitochondrial protein that in nuclei and in vitro repairs blocked 3' DNA termini such as 3' phosphotyrosine conjugates resulting from stalling of topoisomerase I-DNA intermediates. Its mutation also causes spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1). Because Tdp1 colocalizes with mitochondria following oxidative stress, we hypothesized that Tdp1 repairs mitochondrial DNA (mtDNA) and that mtDNA damage mediates entry of Tdp1 into the mitochondria. To test this, we used S. cerevisiae mutants, cultured mouse and human cells, and a Tdp1 knockout mouse. H2O2- and rotenone-induced cellular and intramitochondrial reactive oxygen species (ROS) activated oxidant-responsive kinases P38 and ERK1, and the translocation of Tdp1 from the nucleus to the mitochondria via the TIM/TOM complex. This translocation occurred independently of mtDNA. Within the mitochondria, Tdp1 interacted with Ligase III and reduced mtDNA mutations. Tdp1-deficient tissues had impaired mitochondrial respiration and decreased viability. These observations suggest that Tdp1 maintains mtDNA integrity and support the hypothesis that mitochondrial dysfunction contributes to the pathology of SCAN1.
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20
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Kondo Y, Higa S, Iwasaki T, Matsumoto T, Maehara K, Harada A, Baba Y, Fujita M, Ohkawa Y. Sensitive detection of fluorescence in western blotting by merging images. PLoS One 2018; 13:e0191532. [PMID: 29352284 PMCID: PMC5774814 DOI: 10.1371/journal.pone.0191532] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/05/2018] [Indexed: 01/19/2023] Open
Abstract
The western blotting technique is widely used to analyze protein expression levels and protein molecular weight. The chemiluminescence method is mainly used for detection due to its high sensitivity and ease of manipulation, but it is unsuitable for detailed analyses because it cannot be used to detect multiple proteins simultaneously. Recently, more attention has been paid to the fluorescence detection method because it is more quantitative and is suitable for the detection of multiple proteins simultaneously. However, fluorescence detection can be limited by poor image resolution and low detection sensitivity. Here, we describe a method to detect fluorescence in western blots using fluorescence microscopy to obtain high-resolution images. In this method, filters and fluorescent dyes are optimized to enhance detection sensitivity to a level similar to that of the chemiluminescence method.
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Affiliation(s)
- Yukari Kondo
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Shinichiro Higa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Takeshi Iwasaki
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | | | - Kazumitsu Maehara
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Akihito Harada
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yoshihiro Baba
- Division of Immunology and Genome Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Masatoshi Fujita
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
- * E-mail:
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21
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Kumar M, Joseph SR, Augsburg M, Bogdanova A, Drechsel D, Vastenhouw NL, Buchholz F, Gentzel M, Shevchenko A. MS Western, a Method of Multiplexed Absolute Protein Quantification is a Practical Alternative to Western Blotting. Mol Cell Proteomics 2017; 17:384-396. [PMID: 29192002 DOI: 10.1074/mcp.o117.067082] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 10/12/2017] [Indexed: 12/23/2022] Open
Abstract
Absolute quantification of proteins elucidates the molecular composition, regulation and dynamics of multiprotein assemblies and networks. Here we report on a method termed MS Western that accurately determines the molar abundance of dozens of user-selected proteins at the subfemtomole level in whole cell or tissue lysates without metabolic or chemical labeling and without using specific antibodies. MS Western relies on GeLC-MS/MS and quantifies proteins by in-gel codigestion with an isotopically labeled QconCAT protein chimera composed of concatenated proteotypic peptides. It requires no purification of the chimera and relates the molar abundance of all proteotypic peptides to a single reference protein. In comparative experiments, MS Western outperformed immunofluorescence Western blotting by the protein detection specificity, linear dynamic range and sensitivity of protein quantification. To validate MS Western in an in vivo experiment, we quantified the molar content of zebrafish core histones H2A, H2B, H3 and H4 during ten stages of early embryogenesis. Accurate quantification (CV<10%) corroborated the anticipated histones equimolar stoichiometry and revealed an unexpected trend in their total abundance.
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Affiliation(s)
- Mukesh Kumar
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Shai R Joseph
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Martina Augsburg
- §Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Aliona Bogdanova
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - David Drechsel
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Nadine L Vastenhouw
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Frank Buchholz
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany.,§Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany.,¶German Cancer Research Center (DKFZ), Heidelberg and German Cancer Consortium (DKTK) partner site Dresden, 01307 Dresden, Germany.,‖National Center for Tumor Diseases (NCT), University Hospital Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Marc Gentzel
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Andrej Shevchenko
- From the ‡Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany;
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22
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Nelson GM, Guynn JM, Chorley BN. Procedure and Key Optimization Strategies for an Automated Capillary Electrophoretic-based Immunoassay Method. J Vis Exp 2017. [PMID: 28930974 PMCID: PMC5752198 DOI: 10.3791/55911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
New technologies that utilize capillary-based immunoassays promise faster and more quantitative protein assessment compared to traditional immunoassays. However, similar to other antibody-based protein assays, optimization of capillary-based immunoassay parameters, such as protein concentration, antibody dilution, and exposure time is an important prerequisite to the generation of meaningful and reliable data. Measurements must fall within the linear range of the assay where changes in signal are directly proportional to changes in lysate concentration. The process of choosing appropriate lysate concentrations, antibody dilutions, and exposure times in the human bronchial epithelial cell line, BEAS-2B, is demonstrated here. Assay linearity is shown over a range of whole cell extract protein concentrations with p53 and α-tubulin antibodies. An example of signal burnout is seen at the highest concentrations with long exposure times, and an α-tubulin antibody dilution curve is shown demonstrating saturation. In addition, example experimental results are reported for doxorubicin-treated cells using optimized parameters.
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Affiliation(s)
- Gail M Nelson
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency
| | - Jenna M Guynn
- Oak Ridge Institute for Science and Education at U.S. Environmental Protection Agency
| | - Brian N Chorley
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency;
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23
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Lewis CW, Jin Z, Macdonald D, Wei W, Qian XJ, Choi WS, He R, Sun X, Chan G. Prolonged mitotic arrest induced by Wee1 inhibition sensitizes breast cancer cells to paclitaxel. Oncotarget 2017; 8:73705-73722. [PMID: 29088738 PMCID: PMC5650293 DOI: 10.18632/oncotarget.17848] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 04/27/2017] [Indexed: 11/25/2022] Open
Abstract
Wee1 kinase is a crucial negative regulator of Cdk1/cyclin B1 activity and is required for normal entry into and exit from mitosis. Wee1 activity can be chemically inhibited by the small molecule MK-1775, which is currently being tested in phase I/II clinical trials in combination with other anti-cancer drugs. MK-1775 promotes cancer cells to bypass the cell-cycle checkpoints and prematurely enter mitosis. In our study, we show premature mitotic cells that arise from MK-1775 treatment exhibited centromere fragmentation, a morphological feature of mitotic catastrophe that is characterized by centromeres and kinetochore proteins that co-cluster away from the condensed chromosomes. In addition to stimulating early mitotic entry, MK-1775 treatment also delayed mitotic exit. Specifically, cells treated with MK-1775 following release from G1/S or prometaphase arrested in mitosis. MK-1775 induced arrest occurred at metaphase and thus, cells required 12 times longer to transition into anaphase compared to controls. Consistent with an arrest in mitosis, MK-1775 treated prometaphase cells maintained high cyclin B1 and low phospho-tyrosine 15 Cdk1. Importantly, MK-1775 induced mitotic arrest resulted in cell death regardless the of cell-cycle phase prior to treatment suggesting that Wee1 inhibitors are also anti-mitotic agents. We found that paclitaxel enhances MK-1775 mediated cell killing. HeLa and different breast cancer cell lines (T-47D, MCF7, MDA-MB-468 and MDA-MB-231) treated with different concentrations of MK-1775 and low dose paclitaxel exhibited reduced cell survival compared to mono-treatments. Our data highlight a new potential strategy for enhancing MK-1775 mediated cell killing in breast cancer cells.
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Affiliation(s)
- Cody W Lewis
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.,Experimental Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada T6G 1Z2.,Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada T6G 2J7
| | - Zhigang Jin
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.,Experimental Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada T6G 1Z2.,Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada T6G 2J7
| | - Dawn Macdonald
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.,Experimental Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada T6G 1Z2.,Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada T6G 2J7
| | - Wenya Wei
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2
| | - Xu Jing Qian
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2
| | - Won Shik Choi
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2
| | - Ruicen He
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2
| | - Xuejun Sun
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.,Experimental Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada T6G 1Z2.,Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada T6G 2J7
| | - Gordon Chan
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.,Experimental Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada T6G 1Z2.,Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta, Canada T6G 2J7
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24
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Szunyogova E, Zhou H, Maxwell GK, Powis RA, Francesco M, Gillingwater TH, Parson SH. Survival Motor Neuron (SMN) protein is required for normal mouse liver development. Sci Rep 2016; 6:34635. [PMID: 27698380 PMCID: PMC5048144 DOI: 10.1038/srep34635] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/12/2016] [Indexed: 01/15/2023] Open
Abstract
Spinal Muscular Atrophy (SMA) is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Decreased levels of, cell-ubiquitous, SMN protein is associated with a range of systemic pathologies reported in severe patients. Despite high levels of SMN protein in normal liver, there is no comprehensive study of liver pathology in SMA. We describe failed liver development in response to reduced SMN levels, in a mouse model of severe SMA. The SMA liver is dark red, small and has: iron deposition; immature sinusoids congested with blood; persistent erythropoietic elements and increased immature red blood cells; increased and persistent megakaryocytes which release high levels of platelets found as clot-like accumulations in the heart. Myelopoiesis in contrast, was unaffected. Further analysis revealed significant molecular changes in SMA liver, consistent with the morphological findings. Antisense treatment from birth with PMO25, increased lifespan and ameliorated all morphological defects in liver by postnatal day 21. Defects in the liver are evident at birth, prior to motor system pathology, and impair essential liver function in SMA. Liver is a key recipient of SMA therapies, and systemically delivered antisense treatment, completely rescued liver pathology. Liver therefore, represents an important therapeutic target in SMA.
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Affiliation(s)
- Eva Szunyogova
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Haiyan Zhou
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, United Kingdom
| | - Gillian K. Maxwell
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Rachael A. Powis
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Muntoni Francesco
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, London, United Kingdom
| | - Thomas H. Gillingwater
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Simon H. Parson
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- Euan MacDonald Center for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, United Kingdom
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Nath N, Godat B, Urh M. Antibody Labeling with Fluorescent Dyes Using Magnetic Protein A and Protein G Beads. J Vis Exp 2016. [PMID: 27685323 DOI: 10.3791/54545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Antibodies labeled with small molecules like fluorescent dyes, cytotoxic drugs, and radioactive tracers are essential tools in biomedical research, immunodiagnostics and more recently as therapeutic agents. Traditional methods for labeling antibodies with small molecules require purified antibodies at relatively high concentration, involve multiple dialysis steps and have limited throughput. However, several applications, including the field of Antibody Drug Conjugates (ADCs), will benefit from new methods that will allow labeling of antibodies directly from cell media. Such methods may allow antibodies to be screened in biologically relevant assays, for example, the receptor-mediated antibody internalization assay in the case of ADCs. Here, we describe a method (on-bead method) that enables labeling of small amounts of antibodies directly from cell media. This approach utilizes high capacity magnetic Protein A and Protein G affinity beads to capture antibodies from the cell media followed by labeling with small molecules using either amine or thiol chemistry and subsequent elution of the labeled antibodies. Taking fluorescent dyes as surrogates for small molecules, we demonstrate the on-bead labeling of three different mouse antibodies directly from cell media using both amine and thiol labeling chemistry. The high binding affinity of antibodies to Protein A and Protein G ensures high recoveries as well as high purity of the labeled antibodies. In addition, use of magnetic beads allows multiple samples to be handled manually, thereby significantly improving labeling throughput.
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ImmunoPET for assessing the differential uptake of a CD146-specific monoclonal antibody in lung cancer. Eur J Nucl Med Mol Imaging 2016; 43:2169-2179. [PMID: 27342417 DOI: 10.1007/s00259-016-3442-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
Abstract
PURPOSE Overexpression of CD146 in solid tumors has been linked to disease progression, invasion, and metastasis. We describe the generation of a 64Cu-labeled CD146-specific antibody and its use for quantitative immunoPET imaging of CD146 expression in six lung cancer models. METHODS The anti-CD146 antibody (YY146) was conjugated to 1,4,7-triazacyclononane-triacetic acid (NOTA) and radiolabeled with 64Cu. CD146 expression was evaluated in six human lung cancer cell lines (A549, NCI-H358, NCI-H522, HCC4006, H23, and NCI-H460) by flow cytometry and quantitative western blot studies. The biodistribution and tumor uptake of 64Cu-NOTA-YY146 was assessed by sequential PET imaging in athymic nude mice bearing subcutaneous lung cancer xenografts. The correlation between CD146 expression and tumor uptake of 64Cu-NOTA-YY146 was evaluated by graphical software while ex vivo biodistribution and immunohistochemistry studies were performed to validate the accuracy of PET data and spatial expression of CD146. RESULTS Flow cytometry and western blot studies showed similar findings with H460 and H23 cells showing high levels of expression of CD146. Small differences in CD146 expression levels were found among A549, H4006, H522, and H358 cells. Tumor uptake of 64Cu-NOTA-YY146 was highest in CD146-expressing H460 and H23 tumors, peaking at 20.1 ± 2.86 and 11.6 ± 2.34 %ID/g at 48 h after injection (n = 4). Tumor uptake was lowest in the H522 model (4.1 ± 0.98 %ID/g at 48 h after injection; n = 4), while H4006, A549 and H358 exhibited similar uptake of 64Cu-NOTA-YY146. A positive correlation was found between tumor uptake of 64Cu-NOTA-YY146 (%ID/g) and relative CD146 expression (r 2 = 0.98, p < 0.01). Ex vivo biodistribution confirmed the accuracy of the PET data. CONCLUSION The strong correlation between tumor uptake of 64Cu-NOTA-YY146 and CD146 expression demonstrates the potential use of this radiotracer for imaging tumors that elicit varying levels of CD146. In the future, this tool may promote enhanced monitoring of therapeutic response and improved patient stratification.
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27
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McGorum BC, Pirie RS, Eaton SL, Keen JA, Cumyn EM, Arnott DM, Chen W, Lamont DJ, Graham LC, Llavero Hurtado M, Pemberton A, Wishart TM. Proteomic Profiling of Cranial (Superior) Cervical Ganglia Reveals Beta-Amyloid and Ubiquitin Proteasome System Perturbations in an Equine Multiple System Neuropathy. Mol Cell Proteomics 2015; 14:3072-86. [PMID: 26364976 PMCID: PMC4638047 DOI: 10.1074/mcp.m115.054635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 01/09/2023] Open
Abstract
Equine grass sickness (EGS) is an acute, predominantly fatal, multiple system neuropathy of grazing horses with reported incidence rates of ∼2%. An apparently identical disease occurs in multiple species, including but not limited to cats, dogs, and rabbits. Although the precise etiology remains unclear, ultrastructural findings have suggested that the primary lesion lies in the glycoprotein biosynthetic pathway of specific neuronal populations. The goal of this study was therefore to identify the molecular processes underpinning neurodegeneration in EGS. Here, we use a bottom-up approach beginning with the application of modern proteomic tools to the analysis of cranial (superior) cervical ganglion (CCG, a consistently affected tissue) from EGS-affected patients and appropriate control cases postmortem. In what appears to be the proteomic application of modern proteomic tools to equine neuronal tissues and/or to an inherent neurodegenerative disease of large animals (not a model of human disease), we identified 2,311 proteins in CCG extracts, with 320 proteins increased and 186 decreased by greater than 20% relative to controls. Further examination of selected proteomic candidates by quantitative fluorescent Western blotting (QFWB) and subcellular expression profiling by immunohistochemistry highlighted a previously unreported dysregulation in proteins commonly associated with protein misfolding/aggregation responses seen in a myriad of human neurodegenerative conditions, including but not limited to amyloid precursor protein (APP), microtubule associated protein (Tau), and multiple components of the ubiquitin proteasome system (UPS). Differentially expressed proteins eligible for in silico pathway analysis clustered predominantly into the following biofunctions: (1) diseases and disorders, including; neurological disease and skeletal and muscular disorders and (2) molecular and cellular functions, including cellular assembly and organization, cell-to-cell signaling and interaction (including epinephrine, dopamine, and adrenergic signaling and receptor function), and small molecule biochemistry. Interestingly, while the biofunctions identified in this study may represent pathways underpinning EGS-induced neurodegeneration, this is also the first demonstration of potential molecular conservation (including previously unreported dysregulation of the UPS and APP) spanning the degenerative cascades from an apparently unrelated condition of large animals, to small animal models with altered neuronal vulnerability, and human neurological conditions. Importantly, this study highlights the feasibility and benefits of applying modern proteomic techniques to veterinary investigations of neurodegenerative processes in diseases of large animals.
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Affiliation(s)
- Bruce C. McGorum
- From the Veterinary Clinical Sciences and ,** To whom correspondence should be addressed: ,
| | | | - Samantha L. Eaton
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | | | - Elizabeth M. Cumyn
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | - Danielle M. Arnott
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | - Wenzhang Chen
- FingerPrints: Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Douglas J. Lamont
- FingerPrints: Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Laura C. Graham
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | - Maica Llavero Hurtado
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK
| | | | - Thomas M. Wishart
- §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK; , Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, UK,** To whom correspondence should be addressed: ,
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28
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Eaton SL, Cumyn E, King D, Kline RA, Carpanini SM, Del-Pozo J, Barron R, Wishart TM. Quantitative imaging of tissue sections using infrared scanning technology. J Anat 2015; 228:203-13. [PMID: 26510706 PMCID: PMC4694169 DOI: 10.1111/joa.12398] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2015] [Indexed: 12/12/2022] Open
Abstract
Quantification of immunohistochemically (IHC) labelled tissue sections typically yields semi‐quantitative results. Visualising infrared (IR) ‘tags’, with an appropriate scanner, provides an alternative system where the linear nature of the IR fluorophore emittance enables realistic quantitative fluorescence IHC (QFIHC). Importantly, this new technology enables entire tissue sections to be scanned, allowing accurate area and protein abundance measurements to be calculated from rapidly acquired images. Here, some of the potential benefits of using IR‐based tissue imaging are examined, and the following are demonstrated. Firstly, image capture and analysis using IR‐based scanning technology yields comparable area‐based quantification to those obtained from a modern high‐resolution digital slide scanner. Secondly, IR‐based dual target visualisation and expression‐based quantification is rapid and simple. Thirdly, IR‐based relative protein abundance QIHC measurements are an accurate reflection of tissue sample protein abundance, as demonstrated by comparison with quantitative fluorescent Western blotting data. In summary, it is proposed that IR‐based QFIHC provides an alternative method of rapid whole‐tissue section low‐resolution imaging for the production of reliable and accurate quantitative data.
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Affiliation(s)
| | - Elizabeth Cumyn
- Roslin Institute, University of Edinburgh, Edinburgh, UK.,Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Declan King
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Rachel A Kline
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | | | - Jorge Del-Pozo
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Rona Barron
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Thomas M Wishart
- Roslin Institute, University of Edinburgh, Edinburgh, UK.,Euan MacDonald Centre for Motor Neurone Disease Research, Edinburgh, EH16 4SB, UK
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