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Chang IY, Rahman M, Harned A, Cohen-Fix O, Narayan K. Cryo-fluorescence microscopy of high-pressure frozen C. elegans enables correlative FIB-SEM imaging of targeted embryonic stages in the intact worm. Methods Cell Biol 2020; 162:223-252. [PMID: 33707014 DOI: 10.1016/bs.mcb.2020.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Rapidly changing features in an intact biological sample are challenging to efficiently trap and image by conventional electron microscopy (EM). For example, the model organism C. elegans is widely used to study embryonic development and differentiation, yet the fast kinetics of cell division makes the targeting of specific developmental stages for ultrastructural study difficult. We set out to image the condensed metaphase chromosomes of an early embryo in the intact worm in 3-D. To achieve this, one must capture this transient structure, then locate and subsequently image the corresponding volume by EM in the appropriate context of the organism, all while minimizing a variety of artifacts. In this methodological advance, we report on the high-pressure freezing of spatially constrained whole C. elegans hermaphrodites in a combination of cryoprotectants to identify embryonic cells in metaphase by in situ cryo-fluorescence microscopy. The screened worms were then freeze substituted, resin embedded and further prepared such that the targeted cells were successfully located and imaged by focused ion beam scanning electron microscopy (FIB-SEM). We reconstructed the targeted metaphase structure and also correlated an intriguing punctate fluorescence signal to a H2B-enriched putative polar body autophagosome in an adjacent cell undergoing telophase. By enabling cryo-fluorescence microscopy of thick samples, our workflow can thus be used to trap and image transient structures in C. elegans or similar organisms in a near-native state, and then reconstruct their corresponding cellular architectures at high resolution and in 3-D by correlative volume EM.
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Affiliation(s)
- Irene Y Chang
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States; Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, United States
| | - Mohammad Rahman
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Adam Harned
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States; Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, United States
| | - Orna Cohen-Fix
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Kedar Narayan
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States; Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, United States.
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Usachev KS, Validov SZ, Khusainov IS, Varfolomeev AA, Klochkov VV, Aganov AV, Yusupov MM. Solution structure of the N-terminal domain of the Staphylococcus aureus hibernation promoting factor. J Biomol NMR 2019; 73:223-227. [PMID: 31165320 DOI: 10.1007/s10858-019-00254-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/10/2019] [Indexed: 06/09/2023]
Abstract
Staphylococcus aureus hibernation promoting factor (SaHPF) is a 22,2 kDa protein which plays a crucial role in 100S Staphylococcus aureus ribosome formation during stress. SaHPF consists of N-terminal domain (NTD) that prevents proteins synthesis by binding to the 30S subunit at the P- and A-sites, connected through a flexible linker with a C-terminal domain (CTD) that keeps ribosomes in 100S form via homodimerization. Recently obtained 100S ribosome structure of S. aureus by cryo-EM shown that SaHPF-NTD bound to the ribosome active sites, however due to the absence of SaHPF-NTD structure it was modeled by homology with the E. coli hibernation factors HPF and YfiA. In present paper we have determined the solution structure of SaHPF-NTD by high-resolution NMR spectroscopy which allows us to increase structural knowledge about HPF structure from S. aureus.
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Affiliation(s)
- Konstantin S Usachev
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
- NMR Laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
| | - Shamil Z Validov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
| | - Iskander Sh Khusainov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS, UMR7104, INSERM U964, Université de Strasbourg, 1 rue Laurent Fries, 67400, Illkirch, France
| | - Alexander A Varfolomeev
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
| | - Vladimir V Klochkov
- NMR Laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
| | - Albert V Aganov
- NMR Laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, 420008, Russian Federation
| | - Marat M Yusupov
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS, UMR7104, INSERM U964, Université de Strasbourg, 1 rue Laurent Fries, 67400, Illkirch, France.
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Brodiazhenko T, Johansson MJO, Takada H, Nissan T, Hauryliuk V, Murina V. Elimination of Ribosome Inactivating Factors Improves the Efficiency of Bacillus subtilis and Saccharomyces cerevisiae Cell-Free Translation Systems. Front Microbiol 2018; 9:3041. [PMID: 30619132 PMCID: PMC6305275 DOI: 10.3389/fmicb.2018.03041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/26/2018] [Indexed: 12/29/2022] Open
Abstract
Cell-free translation systems based on cellular lysates optimized for in vitro protein synthesis have multiple applications both in basic and applied science, ranging from studies of translational regulation to cell-free production of proteins and ribosome-nascent chain complexes. In order to achieve both high activity and reproducibility in a translation system, it is essential that the ribosomes in the cellular lysate are enzymatically active. Here we demonstrate that genomic disruption of genes encoding ribosome inactivating factors - HPF in Bacillus subtilis and Stm1 in Saccharomyces cerevisiae - robustly improve the activities of bacterial and yeast translation systems. Importantly, the elimination of B. subtilis HPF results in a complete loss of 100S ribosomes, which otherwise interfere with disome-based approaches for preparation of stalled ribosomal complexes for cryo-electron microscopy studies.
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Affiliation(s)
- Tetiana Brodiazhenko
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Institute of Technology, University of Tartu, Tartu, Estonia
| | | | - Hiraku Takada
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Tracy Nissan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Vasili Hauryliuk
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Victoriia Murina
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
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Basu A, Shields KE, Eickhoff CS, Hoft DF, Yap MN. Thermal and Nutritional Regulation of Ribosome Hibernation in Staphylococcus aureus. J Bacteriol 2018; 200:e00426-18. [PMID: 30297357 DOI: 10.1128/JB.00426-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022] Open
Abstract
The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites. The translationally silent 100S ribosome is a poorly understood form of the dimeric 70S complex that is ubiquitously found in all bacterial phyla. The elimination of the hibernating 100S ribosome leads to translational derepression, ribosome instability, antibiotic sensitivity, and biofilm defects in some bacteria. In Firmicutes, such as the opportunistic pathogen Staphylococcus aureus, a 190-amino acid protein called hibernating-promoting factor (HPF) dimerizes and conjoins two 70S ribosomes through a direct interaction between the HPF homodimer, with each HPF monomer tethered on an individual 70S complex. While the formation of the 100S ribosome in gammaproteobacteria and cyanobacteria is exclusively induced during postexponential growth phase and darkness, respectively, the 100S ribosomes in Firmicutes are constitutively produced from the lag-logarithmic phase through the post-stationary phase. Very little is known about the regulatory pathways that control hpf expression and 100S ribosome abundance. Here, we show that a general stress response (GSR) sigma factor (SigB) and a GTP-sensing transcription factor (CodY) integrate nutrient and thermal signals to regulate hpf synthesis in S. aureus, resulting in an enhanced virulence of the pathogen in a mouse model of septicemic infection. CodY-dependent regulation of hpf is strain specific. An epistasis analysis further demonstrated that CodY functions upstream of the GSR pathway in a condition-dependent manner. The results reveal an important link between S. aureus stress physiology, ribosome metabolism, and infection biology. IMPORTANCE The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites.
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Usachev KS, Ayupov RK, Validov SZ, Khusainov IS, Yusupov MM. NMR assignments of the N-terminal domain of Staphylococcus aureus hibernation promoting factor (Sa HPF). Biomol NMR Assign 2018; 12:85-89. [PMID: 28980143 DOI: 10.1007/s12104-017-9783-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 09/30/2017] [Indexed: 06/07/2023]
Abstract
Staphylococcus aureus: hibernation-promoting factor (SaHPF) is a 22.2 kDa stationary-phase protein that binds to the ribosome and turns it to the inactive form favoring survival under stress. Sequence analysis has shown that this protein is combination of two homolog proteins obtained in Escherichia coli-ribosome hibernation promoting factor (HPF) (11,000 Da) and ribosome modulation factor RMF (6500 Da). Binding site of E. coli HPF on the ribosome have been shown by X-ray study of Thermus thermophilus ribosome complex. Hence, recent studies reported that the interface is markedly different between 100S from S. aureus and E. coli. Cryo-electron microscopy structure of 100S S. aureus ribosomes reveal that the SaHPF-NTD binds to the 30S subunit as observed for shorter variants of HPF in other species and the C-terminal domain (CTD) protrudes out of each ribosome in order to mediate dimerization. SaHPF-NTD binds to the small subunit similarly to its homologs EcHPF, EcYfiA, and a plastid-specific YfiA. Furthermore, upon binding to the small subunit, the SaHPF-NTD occludes several antibiotic binding sites at the A site (hygromycin B, tetracycline), P site (edeine) and E site (pactamycin, kasugamycin). In order to elucidate the structure, dynamics and function of SaHPF-NTD from S. aureus, here we report the backbone and side chain resonance assignments for SaHPF-NTD. Analysis of the backbone chemical shifts by TALOS+ suggests that SaHPF-NTD contains two α-helices and four β-strands (β1-α1-β2-β3-β4-α2 topology). Investigating the long-term survival of S. aureus and other bacteria under antibiotic pressure could lead to advances in antibiotherapy.
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Affiliation(s)
- Konstantin S Usachev
- NMR laboratory, Medical Physics Department, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008.
| | - Rustam Kh Ayupov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008
| | - Shamil Z Validov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008
| | - Iskander Sh Khusainov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, 1 rue Laurent Fries, 67400, Illkirch, France
| | - Marat M Yusupov
- Laboratory of Structural Biology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlevskaya, Kazan, Russian Federation, 420008
- Département de Biologie et de Génomique Structurales, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U964, Université de Strasbourg, 1 rue Laurent Fries, 67400, Illkirch, France
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6
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Gohara DW, Yap MF. Survival of the drowsiest: the hibernating 100S ribosome in bacterial stress management. Curr Genet 2018; 64:753-60. [PMID: 29243175 DOI: 10.1007/s00294-017-0796-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/09/2017] [Accepted: 12/11/2017] [Indexed: 11/24/2022]
Abstract
In response to nutrient deprivation and environmental insults, bacteria conjoin two copies of non-translating 70S ribosomes that form the translationally inactive 100S dimer. This widespread phenomenon is believed to prevent ribosome turnover and serves as a reservoir that, when conditions become favorable, allows the hibernating ribosomes to be disassembled and recycled for translation. New structural studies have revealed two distinct mechanisms for dimerizing 70S ribosomes, but the molecular basis of the disassembly process is still in its infancy. Many details regarding the sequence of dimerization-dissociation events with respect to the binding and departure of the hibernation factor and its antagonizing disassembly factor remain unclear.
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Basu A, Yap MN. Disassembly of the Staphylococcus aureus hibernating 100S ribosome by an evolutionarily conserved GTPase. Proc Natl Acad Sci U S A 2017; 114:E8165-73. [PMID: 28894000 DOI: 10.1073/pnas.1709588114] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The bacterial hibernating 100S ribosome is a poorly understood form of the dimeric 70S particle that has been linked to pathogenesis, translational repression, starvation responses, and ribosome turnover. In the opportunistic pathogen Staphylococcus aureus and most other bacteria, hibernation-promoting factor (HPF) homodimerizes the 70S ribosomes to form a translationally silent 100S complex. Conversely, the 100S ribosomes dissociate into subunits and are presumably recycled for new rounds of translation. The regulation and disassembly of the 100S ribosome are largely unknown because the temporal abundance of the 100S ribosome varies considerably among different bacterial phyla. Here, we identify a universally conserved GTPase (HflX) as a bona fide dissociation factor of the S. aureus 100S ribosome. The expression levels hpf and hflX are coregulated by general stress and stringent responses in a temperature-dependent manner. While all tested guanosine analogs stimulate the splitting activity of HflX on the 70S ribosome, only GTP can completely dissociate the 100S ribosome. Our results reveal the antagonistic relationship of HPF and HflX and uncover the key regulators of 70S and 100S ribosome homeostasis that are intimately associated with bacterial survival.
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Beckert B, Abdelshahid M, Schäfer H, Steinchen W, Arenz S, Berninghausen O, Beckmann R, Bange G, Turgay K, Wilson DN. Structure of the Bacillus subtilis hibernating 100S ribosome reveals the basis for 70S dimerization. EMBO J 2017; 36:2061-2072. [PMID: 28468753 DOI: 10.15252/embj.201696189] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/26/2017] [Accepted: 03/29/2017] [Indexed: 11/09/2022] Open
Abstract
Under stress conditions, such as nutrient deprivation, bacteria enter into a hibernation stage, which is characterized by the appearance of 100S ribosomal particles. In Escherichia coli, dimerization of 70S ribosomes into 100S requires the action of the ribosome modulation factor (RMF) and the hibernation-promoting factor (HPF). Most other bacteria lack RMF and instead contain a long form HPF (LHPF), which is necessary and sufficient for 100S formation. While some structural information exists as to how RMF and HPF mediate formation of E. coli 100S (Ec100S), structural insight into 100S formation by LHPF has so far been lacking. Here we present a cryo-EM structure of the Bacillus subtilis hibernating 100S (Bs100S), revealing that the C-terminal domain (CTD) of the LHPF occupies a site on the 30S platform distinct from RMF Moreover, unlike RMF, the BsHPF-CTD is directly involved in forming the dimer interface, thereby illustrating the divergent mechanisms by which 100S formation is mediated in the majority of bacteria that contain LHPF, compared to some γ-proteobacteria, such as E. coli.
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Affiliation(s)
- Bertrand Beckert
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
| | - Maha Abdelshahid
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
| | - Heinrich Schäfer
- Naturwissenschaftliche Fakultät, Institut für Mikrobiologie, Leibniz Universität Hannover, Hannover, Germany
| | - Wieland Steinchen
- LOEWE Center for Synthetic Microbiology and Faculty of Chemistry, Philipps University Marburg, Marburg, Germany
| | - Stefan Arenz
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
| | - Otto Berninghausen
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
| | - Roland Beckmann
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
| | - Gert Bange
- LOEWE Center for Synthetic Microbiology and Faculty of Chemistry, Philipps University Marburg, Marburg, Germany
| | - Kürşad Turgay
- Naturwissenschaftliche Fakultät, Institut für Mikrobiologie, Leibniz Universität Hannover, Hannover, Germany
| | - Daniel N Wilson
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany .,Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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Abstract
Background Mitotic rate is routinely assessed in breast cancer cases and based on the assessment of 10 high power fields (HPF), a non-standard sample area, as per the College of American Pathologists cancer checklist. The effect of sample area variation has not been assessed. Methods A computer model making use of the binomial distribution was developed to calculate the misclassification rate in 1,000,000 simulated breast specimens using the extremes of field diameter (FD) and mitotic density cutoffs (3 and 8 mitoses/mm2), and for a sample area of 5 mm2. Mitotic counts were assumed to be a random sampling problem using a mitotic rate distribution derived from an experimental study (range 0–16.4 mitoses/mm2). The cellular density was 2500 cell/mm2. Results For the smallest microscopes (FD = 0.40 mm, area 1.26 mm2) 16% of cases were misclassified, compared to 9% of the largest (FD 0.69 mm, area 3.74 mm2), versus 8% for 5 mm2. An excess of 27% of score 2 cases were misclassified as 1 or 3 for the lower FD. Conclusion Mitotic scores based on ten HPFs of a small field area microscope are less reliable measures of the mitotic density than in a bigger field area microscope; therefore, the sample area should be standardized. When mitotic counts are close to the cut-offs the score is less reproducible. These cases could benefit from using larger sample areas. A measure of mitotic density variation due to sampling may assist in the interpretation of the mitotic score. Electronic supplementary material The online version of this article (doi:10.1186/s12938-016-0301-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael Bonert
- St. Joseph's Healthcare Hamilton, McMaster University, Hamilton, ON, Canada.
| | - Angela J Tate
- Eastern Health and Memorial University of Newfoundland, St. John's, NL, Canada
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Cheng L, Sun DW, Zhu Z, Zhang Z. Effects of high pressure freezing ( HPF) on denaturation of natural actomyosin extracted from prawn (Metapenaeus ensis). Food Chem 2017; 229:252-259. [PMID: 28372171 DOI: 10.1016/j.foodchem.2017.02.048] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 12/22/2022]
Abstract
Effects of protein denaturation caused by high pressure freezing, involving Pressure-Factors (pressure, time) and Freezing-Factors (temperature, phase transition, recrystallization, ice crystal types), are complicated. In the current study, the conformation and functional changes of natural actomyosin (NAM) under pressure assisted freezing (PAF, 100,150,300,400,500MPaP-20°C/25min), pressure shift freezing (PSF, 200MPaP-20°C/25min), and immersion freezing (0.1MPaP-20°C/5min) after pressure was released to 0.1MPa, as compared to normal immersion freezing process (IF, 0.1MPaP-20°C/30min). Results indicated that PSF (200MPaP-20°C/30min) could reduce the denaturation of frozen NAM and a pressure of 300MPa was the critical point to induce such a denaturation. During the periods of B→D in PSF or B→C→D in PAF, the generation and growth of ice crystals played an important role on changing the secondary and tertiary structure of the treated NAM.
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Affiliation(s)
- Lina Cheng
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
| | - Da-Wen Sun
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Food Refrigeration and Computerized Food Technology (FRCFT), University College Dublin, National University of Ireland, Agriculture and Food Science Centre, Belfield, Dublin 4, Ireland. http://www.ucd.ie/refrig,http://www.ucd.ie/sun
| | - Zhiwei Zhu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
| | - Zhihang Zhang
- Food Refrigeration and Computerized Food Technology (FRCFT), University College Dublin, National University of Ireland, Agriculture and Food Science Centre, Belfield, Dublin 4, Ireland
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Nikolova LS, Metzstein MM. Intracellular lumen formation in Drosophila proceeds via a novel subcellular compartment. Development 2015; 142:3964-73. [PMID: 26428009 DOI: 10.1242/dev.127902] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/17/2015] [Indexed: 12/28/2022]
Abstract
Cellular tubes have diverse morphologies, including multicellular, unicellular and subcellular architectures. Subcellular tubes are found prominently within the vertebrate vasculature, the insect breathing system and the nematode excretory apparatus, but how such tubes form is poorly understood. To characterize the cellular mechanisms of subcellular tube formation, we have refined methods of high pressure freezing/freeze substitution to prepare Drosophila larvae for transmission electron microscopic (TEM) analysis. Using our methods, we have found that subcellular tube formation may proceed through a previously undescribed multimembrane intermediate composed of vesicles bound within a novel subcellular compartment. We have also developed correlative light/TEM procedures to identify labeled cells in TEM-fixed larval samples. Using this technique, we have found that Vacuolar ATPase (V-ATPase) and the V-ATPase regulator Rabconnectin-3 are required for subcellular tube formation, probably in a step resolving the intermediate compartment into a mature lumen. In general, our ultrastructural analysis methods could be useful for a wide range of cellular investigations in Drosophila larvae.
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Affiliation(s)
- Linda S Nikolova
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Mark M Metzstein
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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12
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Abdelmegeed MA, Banerjee A, Jang S, Yoo SH, Yun JW, Gonzalez FJ, Keshavarzian A, Song BJ. CYP2E1 potentiates binge alcohol-induced gut leakiness, steatohepatitis, and apoptosis. Free Radic Biol Med 2013; 65:1238-1245. [PMID: 24064383 PMCID: PMC3859835 DOI: 10.1016/j.freeradbiomed.2013.09.009] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/12/2013] [Accepted: 09/17/2013] [Indexed: 02/07/2023]
Abstract
Ethanol-inducible cytochrome P450 2E1 (CYP2E1) contributes to increased oxidative stress and steatosis in chronic alcohol-exposure models. However, its role in binge ethanol-induced gut leakiness and hepatic injury is unclear. This study was aimed at investigating the role of CYP2E1 in binge alcohol-induced gut leakiness and the mechanisms of steatohepatitis. Female wild-type (WT) and Cyp2e1-null mice were treated with three doses of binge ethanol (WT-EtOH or Cyp2e1-null-EtOH) (6g/kg oral gavage at 12-h intervals) or dextrose (negative control). Intestinal histology of only WT-EtOH exhibited epithelial alteration and blebbing of lamina propria, and liver histology obtained at 6h after the last ethanol dose showed elevated steatosis with scattered inflammatory foci. These were accompanied by increased levels of serum endotoxin, hepatic enterobacteria, and triglycerides. All these changes, including the intestinal histology and hepatic apoptosis, determined by TUNEL assay, were significantly reversed when WT-EtOH mice were treated with the specific inhibitor of CYP2E1 chlormethiazole and the antioxidant N-acetylcysteine, both of which suppressed oxidative markers including intestinal CYP2E1. WT-EtOH also exhibited elevated amounts of serum TNF-α, hepatic cytokines, CYP2E1, and lipid peroxidation, with decreased levels of mitochondrial superoxide dismutase and suppressed aldehyde dehydrogenase 2 activity. Increased hepatocyte apoptosis with elevated levels of proapoptotic proteins and decreased levels of active (phosphorylated) p-AKT, p-AMPK, and peroxisome proliferator-activated receptor-α, all of which are involved in fat metabolism and inflammation, were observed in WT-EtOH. These changes were significantly attenuated in the corresponding Cyp2e1-null-EtOH mice. These data indicate that both intestinal and hepatic CYP2E1 induced by binge alcohol seems critical in binge alcohol-mediated increased nitroxidative stress, gut leakage, and endotoxemia; altered fat metabolism; and inflammation contributing to hepatic apoptosis and steatohepatitis.
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Affiliation(s)
- Mohamed A Abdelmegeed
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892-9410, USA
| | - Atrayee Banerjee
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892-9410, USA
| | - Sehwan Jang
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892-9410, USA
| | - Seong-Ho Yoo
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, South Korea
| | - Jun-Won Yun
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892-9410, USA
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ali Keshavarzian
- Division of Gastroenterology, Rush University Medical Center, Chicago, IL 60612, USA
| | - Byoung-Joon Song
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892-9410, USA.
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Wen T, Stucke EM, Grotjan TM, Kemme KA, Abonia JP, Putnam PE, Franciosi JP, Garza JM, Kaul A, King EC, Collins MH, Kushner JP, Rothenberg ME. Molecular diagnosis of eosinophilic esophagitis by gene expression profiling. Gastroenterology 2013; 145:1289-99. [PMID: 23978633 PMCID: PMC4070519 DOI: 10.1053/j.gastro.2013.08.046] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 08/13/2013] [Accepted: 08/20/2013] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Gene expression profiling provides an opportunity for definitive diagnosis but has not yet been well applied to inflammatory diseases. Here we describe an approach for diagnosis of an emerging form of esophagitis, eosinophilic esophagitis (EoE), which is currently diagnosed by histology and clinical symptoms. METHODS We developed an EoE diagnostic panel (EDP) comprising a 96-gene quantitative polymerase chain reaction array and an associated dual-algorithm that uses cluster analysis and dimensionality reduction using a cohort of randomly selected esophageal biopsy samples from pediatric patients with EoE (n = 15) or without EoE (non-EoE controls, n = 14) and subsequently vetted the EDP using a separate cohort of 194 pediatric and adult patient samples derived from both fresh or formalin-fixed, paraffin-embedded tissue: active EoE (n = 91), control (non-EoE and EoE remission, n = 57), histologically ambiguous (n = 34), and reflux (n = 12) samples. RESULTS The EDP identified adult and pediatric patients with EoE with approximately 96% sensitivity and approximately 98% specificity, and distinguished patients with EoE in remission from controls, as well as identified patients exposed to swallowed glucorticoids. The EDP could be used with formalin-fixed, paraffin-embedded tissue RNA and distinguished patients with EoE from those with reflux esophagitis, identified by pH-impedance testing. Preliminary evidence showed that the EDP could identify patients likely to have disease relapse after treatment. CONCLUSIONS We developed a molecular diagnostic test (referred to as the EDP) that identifies patients with esophagitis in a fast, objective, and mechanistic manner, offering an opportunity to improve diagnosis and treatment, and a platform approach for other inflammatory diseases.
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Affiliation(s)
- Ting Wen
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Emily M. Stucke
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Tommie M. Grotjan
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Katherine A. Kemme
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - J. Pablo Abonia
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Philip E. Putnam
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - James P. Franciosi
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Jose M. Garza
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Ajay Kaul
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Eileen C. King
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Margaret H. Collins
- Division of Pediatric Pathology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Jonathan P. Kushner
- Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Marc E. Rothenberg
- Division of Allergy and Immunology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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Yang M, Ramachandran A, Yan HM, Woolbright BL, Copple BL, Fickert P, Trauner M, Jaeschke H. Osteopontin is an initial mediator of inflammation and liver injury during obstructive cholestasis after bile duct ligation in mice. Toxicol Lett 2013; 224:186-95. [PMID: 24188933 DOI: 10.1016/j.toxlet.2013.10.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 12/13/2022]
Abstract
Osteopontin (OPN) is a chemotactic factor which can be cleaved to the pro-inflammatory form by matrix metalloproteinases (MMPs). To test the hypothesis that OPN can modulate inflammatory liver injury during cholestasis, wild-type (WT) C57BL/6 and OPN knockout (OPN-KO) mice underwent bile duct ligation (BDL). OPN-KO mice showed significant reduction in liver injury (plasma ALT and necrosis) and neutrophil recruitment compared with WT animals at 24h but not 72h after BDL. In WT mice, a 4-fold increase in hepatic MMP-3 mRNA and elevated MMP activities and cleaved OPN levels were observed in bile. WT mice subjected to BDL in the presence of the MMP inhibitor BB-94 showed reduced liver injury, less neutrophil extravasation and diminished levels of cleaved OPN in bile. Thus, during obstructive cholestasis, OPN released from biliary epithelial cells could be cleaved by MMPs in bile. When the biliary system leaks, cleaved OPN enters the parenchyma and attracts neutrophils. In the absence of OPN, other chemoattractants, e.g. chemokines, mediate a delayed inflammatory response and injury. Taken together, our data suggest that OPN is the pro-inflammatory mediator that initiates the early neutrophil-mediated injury phase during obstructive cholestasis in mice.
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Affiliation(s)
- Min Yang
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
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15
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Kasten J, Hu C, Bhargava R, Park H, Tai D, Byrne JA, Marescau B, De Deyn PP, Schlichting L, Grody WW, Cederbaum SD, Lipshutz GS. Lethal phenotype in conditional late-onset arginase 1 deficiency in the mouse. Mol Genet Metab 2013; 110:222-30. [PMID: 23920045 PMCID: PMC3800271 DOI: 10.1016/j.ymgme.2013.06.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/25/2013] [Accepted: 06/25/2013] [Indexed: 02/03/2023]
Abstract
Human arginase deficiency is characterized by hyperargininemia and infrequent episodes of hyperammonemia, which lead to neurological impairment with spasticity, loss of ambulation, seizures, and severe mental and growth retardation; uncommonly, patients suffer early death from this disorder. In a murine targeted knockout model, onset of the phenotypic abnormality is heralded by weight loss at around day 15, and death occurs typically by postnatal day 17 with hyperargininemia and markedly elevated ammonia. This discrepancy between the more attenuated juvenile-onset human disease and the lethal neonatal murine model has remained suboptimal for studying and developing therapy for the more common presentation of arginase deficiency. These investigations aimed to address this issue by creating an adult conditional knockout mouse to determine whether later onset of arginase deficiency also resulted in lethality. Animal survival and ammonia levels, body weight, circulating amino acids, and tissue arginase levels were examined as outcome parameters after widespread Cre-recombinase activation in a conditional knockout model of arginase 1 deficiency. One hundred percent of adult female and 70% of adult male mice died an average of 21.0 and 21.6 days, respectively, after the initiation of tamoxifen administration. Animals demonstrated elevated circulating ammonia and arginine at the onset of phenotypic abnormalities. In addition, brain and liver amino acids demonstrated abnormalities. These studies demonstrate that (a) the absence of arginase in adult animals results in a disease profile (leading to death) similar to that of the targeted knockout and (b) the phenotypic abnormalities seen in the juvenile-onset model are not exclusive to the age of the animal but instead to the biochemistry of the disorder. This adult model will be useful for developing gene- and cell-based therapies for this disorder that will not be limited by the small animal size of neonatal therapy and for developing a better understanding of the characteristics of hyperargininemia.
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Affiliation(s)
- Jennifer Kasten
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Chuhong Hu
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Ragini Bhargava
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Hana Park
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Denise Tai
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - James A. Byrne
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Bart Marescau
- Laboratory of Neurochemistry and Behavior, University of Antwerp and Institute Born Bunge, Antwerp, Belgium
| | - Peter P. De Deyn
- Laboratory of Neurochemistry and Behavior, University of Antwerp and Institute Born Bunge, Antwerp, Belgium
| | - Lisa Schlichting
- Biochemical Genetics Laboratory, University of Colorado, Denver, CO, USA
| | - Wayne W. Grody
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Stephen D. Cederbaum
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Intellectual and Developmental Disabilities Research Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Gerald S. Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Intellectual and Developmental Disabilities Research Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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16
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Righi A, Morandi L, Leonardi E, Farnedi A, Marucci G, Sisto A, Frank G, Faustini-Fustini M, Zoli M, Mazzatenta D, Agati R, Foschini MP. Galectin-3 expression in pituitary adenomas as a marker of aggressive behavior. Hum Pathol 2013; 44:2400-9. [PMID: 24007691 DOI: 10.1016/j.humpath.2013.05.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 05/27/2013] [Accepted: 05/31/2013] [Indexed: 01/01/2023]
Abstract
The purpose of this retrospective study was to investigate the role of galectin-3 (LGALS3) expression in predicting the recurrence and the progression potential of prolactin (PRL) and adrenocorticotropic hormone (ACTH)-producing pituitary adenomas and its correlation with the RUNX1 and RUNX2 transcription factors involved in the regulation mechanism of LGALS3 expression. Clinical, neuroradiologic, and follow-up data from 92 pituitary adenomas, including 59 PRL cell adenomas and 33 ACTH-functioning pituitary adenomas, were collected. The LGALS3 expression was analyzed by both immunohistochemistry and quantitative real time-polymerase chain reaction, whereas RUNX1 and RUNX2 were analyzed by quantitative real time-polymerase chain reaction only. The data obtained indicated that invasive growth with suprasellar extension, Ki-67 labeling index, and LGALS3 immunohistochemical and/or LGALS3 messenger RNA levels are the most important histologic features for assessing a high risk of progression or recurrence of PRL- and ACTH-functioning pituitary adenomas. Multivariate Cox regression analysis assessed LGALS3 immunohistochemical positivity in at least 30% of neoplastic cells and/or LGALS3 messenger RNA positivity (P < .001) as strong predictive factors of recurrence/tumor progression followed by a Ki-67 labeling index greater than 3% (P = .019) in the 81 cases in which follow-up data were available. In addition, a significant correlation between LGALS3 and RUNX1 expression levels (P = .0435) was found. This retrospective immunohistochemical and molecular study demonstrated that LGALS3 expression appeared to be a predictive factor of the aggressive behavior of PRL- and ACTH-functioning pituitary adenomas, and its expression was correlated with RUNX1 expression levels.
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17
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Robinson S, Mann J, Vasilaki A, Mathers J, Burt A, Oakley F, White S, Mann D. Pathogenesis of FOLFOX induced sinusoidal obstruction syndrome in a murine chemotherapy model. J Hepatol 2013; 59:318-26. [PMID: 23624001 PMCID: PMC3710969 DOI: 10.1016/j.jhep.2013.04.014] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Sinusoidal obstruction syndrome (SOS) following oxaliplatin based chemotherapy can have a significant impact on post-operative outcome following resection of colorectal liver metastases. To date no relevant experimental models of oxaliplatin induced SOS have been described. The aim of this project was to establish a rodent model which could be utilised to investigate mechanisms underlying SOS to aid the development of therapeutic strategies. METHODS C57Bl/6 mice, maintained on a purified diet, were treated with intra-peritoneal FOLFOX (n=10), or vehicle (n=10), weekly for five weeks and culled one week following final treatment. Sections of the liver and spleen were fixed in formalin and paraffin embedded for histological analysis. The role of oxidative stress on experimental-induced SOS was determined by dietary supplementation with butylated hydroxyanisole and N-acetylcysteine. RESULTS FOLFOX treatment was associated with the development of sinusoidal dilatation and hepatocyte atrophy on H&E stained sections of the liver in keeping with SOS. Immunohistochemistry for p21 demonstrated the presence of replicative senescence within the sinusoidal endothelium. FOLFOX induced endothelial damage leads to a pro-thrombotic state within the liver associated with upregulation of PAI-1 (p<0.001), vWF (p<0.01) and Factor X (p<0.001), which may contribute to the propagation of liver injury. Dietary supplementation with the antioxidant BHA prevented the development of significant SOS. CONCLUSIONS We have developed the first reproducible model of chemotherapy induced SOS that reflects the pathogenesis of this disease in patients. It appears that the use of antioxidants alongside oxaliplatin based chemotherapy may be of value in preventing the development of SOS in patients with colorectal liver metastases.
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Affiliation(s)
- S.M. Robinson
- Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK,Department of HPB Surgery, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK,Corresponding author. Address: Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - J. Mann
- Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - A. Vasilaki
- Institute of Ageing and Chronic Disease, University of Liverpool, Daulby Street, Liverpool L69 3GA, UK
| | - J. Mathers
- Human Nutrition Research Centre, Centre for Brain Ageing and Vitality, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - A.D. Burt
- School of Medicine, The University of Adelaide, Frome Road, Adelaide 5005, Australia
| | - F. Oakley
- Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - S.A. White
- Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK,Department of HPB Surgery, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK
| | - D.A. Mann
- Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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18
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Zimmermann B, Girard F, Mészàr Z, Celio MR. Expression of the calcium binding proteins Necab-1,-2 and -3 in the adult mouse hippocampus and dentate gyrus. Brain Res 2013; 1528:1-7. [PMID: 23850650 DOI: 10.1016/j.brainres.2013.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 04/24/2013] [Accepted: 06/04/2013] [Indexed: 10/26/2022]
Abstract
The family of EF-hand calcium binding proteins is composed of more than 250 members. In search for other neuronal markers, we studied the expression pattern of Necab-1, -2 and -3 in the Ammons horn of adult mice at the gene- and protein levels using in-situ hybridization and immunohistochemistry. The genes for the three Necab's were expressed in specific, non-overlapping areas of the hippocampus. A minority of the Necab-positive interneurons were GABA-ergic, and they virtually never coexpressed one of the classical calcium binding proteins (calretinin, calbindin D-28k and parvalbumin). Necab's are promising new neuronal markers in the brain.
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Affiliation(s)
- B Zimmermann
- Division of Anatomy and Program in Neuroscience, University of Fribourg, Rte. A.Gockel 1, CH-1700 Fribourg, Switzerland
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19
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Mesman RJ. A novel method for high-pressure freezing of adherent cells for frozen hydrated sectioning and CEMOVIS. J Struct Biol 2013; 183:527-530. [PMID: 23831450 DOI: 10.1016/j.jsb.2013.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/25/2013] [Accepted: 06/27/2013] [Indexed: 11/19/2022]
Abstract
With the development of Cryo Electron Microscopy Of Vitreous Sections (CEMOVIS), imaging cells in a close to native state has become a reality. However with the commonly used carriers for high-pressure freezing and cryo-sectioning, adherent grown cells either need to be detached from their substrate. Here a new method is presented for high-pressure freezing adherent growing cells for frozen-hydrated sectioning and CEMOVIS. Cells are cultured on golden grids, containing a carbon coated Formvar film, and frozen on a membrane carrier which provides the grids with the structural support needed to withstand the strain of trimming and cryo-sectioning. This method was successfully tested for the two different types of high-pressure freezers, those using a pressure chamber (HPM010, EMHPF, Wohlwend Compact 01/02, HPM100) and those directly pressurizing the sample (EMPact series).
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Affiliation(s)
- R J Mesman
- Membrane Enzymology, Department of Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; Biomolecular Imaging, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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20
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Margus H, Padari K, Pooga M. Insights into cell entry and intracellular trafficking of peptide and protein drugs provided by electron microscopy. Adv Drug Deliv Rev 2013; 65:1031-8. [PMID: 23624037 DOI: 10.1016/j.addr.2013.04.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 03/22/2013] [Accepted: 04/09/2013] [Indexed: 01/06/2023]
Abstract
For widening the arsenal of protein and peptide therapeutics that act within cells, their cell-entry mechanisms, intracellular trafficking and distribution need to be characterized in detail. Immunofluorescence microscopy has been a prevalent tool for these studies. However, due to the limited resolution, it is often complemented with other methods. This article focuses on the perspectives of electron microscopy in tracking the intracellular delivery and trafficking of proteins, peptides and their carriers. This review introduces the electron microscopy techniques and labeling methods currently used for studying the cellular whereabouts of peptides and proteins with a focus on their intracellular trafficking. Since cell-penetrating peptides have widely been harnessed as carriers for proteins and peptides, and their usage is rapidly expanding, a particular emphasis has been placed on their applications and cell-entry mechanisms.
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21
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Piao JL, Cui ZG, Furusawa Y, Ahmed K, Rehman MU, Tabuchi Y, Kadowaki M, Kondo T. The molecular mechanisms and gene expression profiling for shikonin-induced apoptotic and necroptotic cell death in U937 cells. Chem Biol Interact 2013; 205:119-27. [PMID: 23811387 DOI: 10.1016/j.cbi.2013.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/12/2013] [Accepted: 06/17/2013] [Indexed: 01/01/2023]
Abstract
Shikonin (SHK), a natural naphthoquinone derived from the Chinese medical herb Lithospermum erythrorhizon, induces both apoptosis and necroptosis in several cancer cell lines. However, the detailed molecular mechanisms involved in the initiation of cell death are still unclear. In the present study, caspase-dependent apoptosis was induced by SHK treatment at 1μM after 6h in U937 cells, with increase in DNA fragmentation, generation of intracellular reactive oxygen species (ROS), fraction of cells with low mitochondrial membrane potential (MMP), and in the expression of BH3 only proteins Noxa and tBid. Interestingly, caspase-independent cell death was also detected with SHK treatment at 10μM, observed as increase in SYTOX® Green staining and release of lactate dehydrogenase (LDH). Necrostatin-1 (Nec-1) completely inhibited the SHK-induced leakage of LDH and SYTOX® Green staining. Cell permeable exogenous glutathione (GSH) completely inhibited 1μM SHK-induced apoptosis and converted 10μM SHK-induced necroptosis to apoptosis. Gene expression profiling revealed that 353 genes were found to be significantly regulated by 1μM and 85 genes by 10μM of SHK treatment, respectively. Among these genes, the transcription factor 3 (ATF3) and DNA-damage-inducible transcript 3 (DDIT3) were highly expressed at 1μM of SHK treatment, while tumor necrosis factor (TNF) expression mainly increased at 10μM treatment. These findings provide novel information for the molecular mechanism of SHK-induced apoptosis and necroptosis.
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Affiliation(s)
- Jin-Lan Piao
- Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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Esheba GES, Esheba NES. Angiomyolipoma of the kidney: clinicopathological and immunohistochemical study. J Egypt Natl Canc Inst 2013; 25:125-34. [PMID: 23932749 DOI: 10.1016/j.jnci.2013.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/03/2013] [Accepted: 05/14/2013] [Indexed: 11/29/2022] Open
Abstract
OVERVIEW Although angiomyolipoma (AML) is a relatively rare entity, it is the most common benign mesenchymal neoplasm of the kidney. THE AIM OF THIS STUDY To highlight the clinicopathological characteristics of AML and to assess the role of Human Melanoma Black-45 (HMB-45), Melan-A, smooth muscle actin (SMA), S-100 and cytokeratin in its diagnosis. MATERIALS AND METHODS The study included 15 cases of AML. Clinical and radiological data were retrieved from the archival files and all cases were subjected to a histopathological evaluation as well as immunohistochemical staining for HMB-45, Melan-A, SMA, S-100, and cytokeratin. RESULTS AML was more common in females (female:male = 4:1), the mean age was 53.9 ± 6.45 years. 60% of patients were symptomatic while the remaining 40% were asymptomatic. A statistically significant relationship was found between size of the tumor and the presence of the symptoms (P = 0.02). Patients with tumor size less than 4 cm were asymptomatic, while those with tumor size larger than 4 cm had different symptoms. Thirteen cases were classic AML, while 2 cases were epithelioid AML. Classic AML demonstrated admixture of fatty tissue, thick-walled blood vessels, and smooth muscle, while epithelioid AML was composed mainly of epithelioid cells and contained no fat. HMB-45 was positive in all cases of AML (100%), Melan-A was positive in 13/15 (87%) while SMA was positive in 11/15 (73%) of AML with variable staining intensity. All cases of AML were negative for S-100 and cytokeratin. CONCLUSION AMLs have characteristic clinicopathological and immunohistochemical features and their recognition is crucial for proper diagnosis and treatment.
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