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Wang R, Lou J, Cai J. Strategies to attenuate ciprofloxacin inhibition on enhanced biological phosphorus removal from wastewater and its recoverability. J Environ Manage 2024; 354:120456. [PMID: 38412731 DOI: 10.1016/j.jenvman.2024.120456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 09/28/2023] [Revised: 01/22/2024] [Accepted: 02/20/2024] [Indexed: 02/29/2024]
Abstract
The inhibiting effects of ciprofloxacin (CIP) on enhanced biological phosphorus removal (EBPR) were investigated with no change in reactor operation and with increased aeration rate and sludge retention time (SRT) to explore inhibition-alleviating solutions. Additionally, performance recoverability was evaluated. The results showed that the phosphorus removal efficiency in the presence of 0.002-0.092 mg/L CIP for 7 days was only 12.5%. Increasing the aeration rate relieved inhibition (33.5% phosphorus removal efficiency on Day 7), and increasing SRT slowed EBPR performance deterioration. The EBPR performance recovered from CIP inhibition and increases in the aeration rate and SRT resulted in different recovery phenomena. The maximum PO43--P release rate continued to decrease in the first 2 days of the recovery stage and then gradually increased. However, the maximum PO43--P uptake rate immediately increased at different rates among reactors, which might be attributed to variations in the microbial community structure, decreased poly-P content, and enhanced abundances of ABC transporters and quorum sensing. It was found that some microorganisms associated with phosphorus removal were more tolerant to CIP than glycogen accumulating organisms. Moreover, the increased relative abundance of the qepA gene indicated that the microorganisms in the EBPR system had strong antibiotic resistance capacity. The bacterial community structure was significantly affected by CIP and could not recover to the initial structure. The results help to provide technical support for the operation of the EBPR process in the presence of CIP and to increase the understanding of system recoverability.
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Affiliation(s)
- Ruyi Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
| | - Juqing Lou
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
| | - Jing Cai
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
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DasGupta S, Nykiel K, Piccirilli JA. The hammerhead self-cleaving motif as a precursor to complex endonucleolytic ribozymes. RNA 2021; 27:1017-1024. [PMID: 34131025 PMCID: PMC8370743 DOI: 10.1261/rna.078813.121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 06/07/2021] [Indexed: 06/12/2023]
Abstract
Connections between distinct catalytic RNA motifs through networks of mutations that retain catalytic function (neutral networks) were likely central to the evolution of biocatalysis. Despite suggestions that functional RNAs collectively form an interconnected web of neutral networks, little evidence has emerged to demonstrate the existence of such intersecting networks in naturally occurring RNAs. Here we show that neutral networks of two naturally occurring, seemingly unrelated endonucleolytic ribozymes, the hammerhead (HH) and hairpin (HP), intersect. Sequences at the intersection of these networks exhibit catalytic functions corresponding to both ribozymes by potentially populating both catalytic folds and enable a smooth crossover between the two. Small and structurally simple endonucleolytic motifs like the HH ribozyme could, through mutational walks along their neutral networks, encounter novel catalytic phenotypes, and structurally flexible, bifunctional sequences at the intersection of these networks could have acted as nodes for evolutionary diversification in an RNA world. Considering the simplicity and small size of the HH ribozyme, we propose that this self-cleaving motif could have been a precursor to other more complex endonucleolytic ribozymes. More generally, our results suggest that RNAs that possess distinct sequences, structures, and catalytic functions, can potentially share evolutionary history through mutational connections in sequence space.
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Affiliation(s)
- Saurja DasGupta
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - Kamila Nykiel
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
| | - Joseph A Piccirilli
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
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3
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Stremke ER, Wiese GN, Moe SM, Wastney ME, Moorthi RN, Hill Gallant KM. Intestinal Phosphorus Absorption in Moderate CKD and Healthy Adults Determined Using a Radioisotopic Tracer. J Am Soc Nephrol 2021; 32:2057-2069. [PMID: 34244325 PMCID: PMC8455256 DOI: 10.1681/asn.2020091340] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 03/15/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Reducing intestinal phosphorus absorption is a cornerstone in CKD-MBD management. Yet, knowledge gaps include how CKD pathophysiology affects intestinal phosphorus absorption. In vivo rodent studies suggest that intestinal phosphorus absorption remains inappropriately normal in early-moderate CKD, despite declining 1,25-dihydroxyvitamin D (1,25D). We measured intestinal phosphorus absorption in patients with moderate CKD versus healthy adults using a direct radiotracer method. METHODS Patients with CKD and healthy adults matched for age, sex, and race were enrolled in this 8-day controlled diet study: the first 6 days outpatient and the final 2 days inpatient. Oral and intravenous doses of 33P and serial blood and urine sampling determined intestinal phosphorus absorption during the final 2 days. Secondary outcomes included fasting biochemistries and 24-hour urine phosphorus (uP). RESULTS In total, n=8 patients with CKD (eGFR=29-55 ml/min per 1.73 m2) and n=8 matched healthy controls completed the study. On a controlled diet, no difference in fractional intestinal phosphorus absorption was detected between patients with CKD and healthy adults (0.69 versus 0.62, respectively; P=0.52), and this was similar for 24-hour uP (884 versus 935 mg/d, respectively; P=0.70). Fractional intestinal phosphorus absorption was not significantly related to 24-hour uP. Patients with CKD had higher serum intact PTH and intact FGF23 and lower 1,25D. The relationship between 1,25D and fractional intestinal phosphorus absorption was not statistically significant. CONCLUSIONS Intestinal phosphorus absorption with typical dietary intake did not differ in patients with moderate CKD compared with controls, despite lower serum 1,25D levels. In this setting, a relationship between 24-hour uP and fractional or absolute intestinal absorption was not evident. Further investigation is needed to determine what factors influence intestinal phosphorus absorption in CKD and the apparent lack of compensation by the intestine to limit phosphorus absorption in the face of declining kidney function and reduced 1,25D. Whether this is evident across a range of dietary phosphorus intakes, as well as CKD severity, also needs to be determined. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER Phosphorus Absorption in Healthy Adults and in Patients with Moderate Chronic Kidney Disease, NCT03108222.
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Affiliation(s)
- Elizabeth R. Stremke
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota
| | - Gretchen N. Wiese
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
| | - Sharon M. Moe
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Medicine, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| | - Meryl E. Wastney
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
- Metabolic Modeling Services, West Lafayette, Indiana
| | - Ranjani N. Moorthi
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kathleen M. Hill Gallant
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, Minnesota
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Wang P, Roider E, Coulter ME, Walsh CA, Kramer CS, Beuning PJ, Giese RW. DNA Adductomics by mass tag prelabeling. Rapid Commun Mass Spectrom 2021; 35:e9095. [PMID: 33821547 PMCID: PMC10668917 DOI: 10.1002/rcm.9095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE As a new approach to DNA adductomics, we directly reacted intact, double-stranded (ds)-DNA under warm conditions with an alkylating mass tag followed by analysis by liquid chromatography/mass spectrometry. This method is based on the tendency of adducted nucleobases to locally disrupt the DNA structure (forming a "DNA bubble") potentially increasing exposure of their nucleophilic (including active hydrogen) sites for preferential alkylation. Also encouraging this strategy is that the scope of nucleotide excision repair is very broad, and this system primarily recognizes DNA bubbles. METHODS A cationic xylyl (CAX) mass tag with limited nonpolarity was selected to increase the retention of polar adducts in reversed-phase high-performance liquid chromatography (HPLC) for more detectability while maintaining resolution. We thereby detected a diversity of DNA adducts (mostly polar) by the following sequence of steps: (1) react DNA at 45°C for 2 h under aqueous conditions with CAX-B (has a benzyl bromide functional group to label active hydrogen sites) in the presence of triethylamine; (2) remove residual reagents by precipitating and washing the DNA (a convenient step); (3) digest the DNA enzymatically to nucleotides and remove unlabeled nucleotides by nonpolar solid-phase extraction (also a convenient step); and (4) detect CAX-labeled, adducted nucleotides by LC/MS2 or a matrix-assisted laser desorption/ionization (MALDI)-MS technique. RESULTS Examples of the 42 DNA or RNA adducts detected, or tentatively so based on accurate mass and fragmentation data, are as follows: 8-oxo-dGMP, ethyl-dGMP, hydroxyethyl-dGMP (four isomers, all HPLC-resolved), uracil-glycol, apurinic/apyrimidinic sites, benzo[a]pyrene-dGMP, and, for the first time, benzoquinone-hydroxymethyl-dCMP. Importantly, these adducts are detected in a single procedure under a single set of conditions. Sensitivity, however, is only defined in a preliminary way, namely the latter adduct seems to be detected at a level of about 4 adducts in 109 nucleotides (S/N ~30). CONCLUSIONS CAX-Prelabeling is an emerging new technique for DNA adductomics, providing polar DNA adductomics in a practical way for the first time. Further study of the method is encouraged to better characterize and extend its performance, especially in scope and sensitivity.
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Affiliation(s)
- Poguang Wang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Elisabeth Roider
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Center for Life Sciences, Harvard Medical School, Boston, MA, USA
| | - Caitlin S Kramer
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Penny J Beuning
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Roger W Giese
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
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Chen YW, Liu HQ, Wu QX, Huang YH, Tung YY, Lin MH, Lin CH, Chen TC, Lin EC, Hwang DW. pH Mapping of Skeletal Muscle by Chemical Exchange Saturation Transfer (CEST) Imaging. Cells 2020; 9:E2610. [PMID: 33291803 PMCID: PMC7762073 DOI: 10.3390/cells9122610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/13/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Magnetic resonance imaging (MRI) is extensively used in clinical and basic biomedical research. However, MRI detection of pH changes still poses a technical challenge. Chemical exchange saturation transfer (CEST) imaging is a possible solution to this problem. Using saturation transfer, alterations in the exchange rates between the solute and water protons because of small pH changes can be detected with greater sensitivity. In this study, we examined a fatigued skeletal muscle model in electrically stimulated mice. The measured CEST signal ratio was between 1.96 ppm and 2.6 ppm in the z-spectrum, and this was associated with pH values based on the ratio between the creatine (Cr) and the phosphocreatine (PCr). The CEST results demonstrated a significant contrast change at the electrical stimulation site. Moreover, the pH value was observed to decrease from 7.23 to 7.15 within 20 h after electrical stimulation. This pH decrease was verified by 31P magnetic resonance spectroscopy and behavioral tests, which showed a consistent variation over time.
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Affiliation(s)
- Yu-Wen Chen
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Hong-Qing Liu
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
| | - Qi-Xuan Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi 621, Taiwan;
| | - Yu-Han Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- The Department of Biotechnology, Ming Chuan University, Taoyuan 333, Taiwan
| | - Yu-Ying Tung
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Ming-Huang Lin
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Chia-Huei Lin
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Tsai-Chen Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- The Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Eugene C. Lin
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi 621, Taiwan;
| | - Dennis W. Hwang
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
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Vernon EL, Bean TP, Jha AN. Assessing relative biomarker responses in marine and freshwater bivalve molluscs following exposure to phosphorus 32 ( 32P): Application of genotoxicological and molecular biomarkers. J Environ Radioact 2020; 213:106120. [PMID: 31783294 DOI: 10.1016/j.jenvrad.2019.106120] [Citation(s) in RCA: 2] [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: 07/26/2019] [Revised: 11/12/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
Anthropogenic radionuclides can enter water bodies through accidental or controlled discharges. In order to assess their potential impact, understanding the link between exposure, tissue specific bioaccumulation and radiation dose rate, to biological or biomarker responses in aquatic biota is required. Adopting an integrated, multi-biomarker, multi-species approach, we have investigated potential biological responses induced by short-lived radionuclide, phosphorus-32 (32P, radiophosphorus) in two ecologically important mussel species, the freshwater Dreissena polymorpha (DP) and marine Mytilus galloprovincialis (MG). Adult individuals were exposed to 32P for 10 days, to acquire nominal whole-body average dose rates of 0.10, 1 and 10 mGy d-1, which encompass a screening value of 10 μGy h-1 (0.24 mGy d-1), in accordance with the ERICA tool. Following exposure, a suite of genotoxic biomarkers (DNA damage, γ-H2AX induction and micronucleus [MN] formation) were measured in gill and digestive gland tissues, along with transcriptional expression of selected stress-related genes in both the species (i.e. hsp70/90, sod, cat and gst). Our results demonstrate the relationship between tissue specific dosimetry, where 32P induced a dose-dependent increase, and biological responses independent of species. Gene expression analysis revealed little significant variation across species or tissues. Overall, MG appeared to be more sensitive to short-term damage (i.e. high DNA damage and γ-H2AX induction), particularly in digestive gland. This study contributes to limited knowledge on the transfer and biological impact of radionuclides within differing aquatic systems on a tissue specific level, aiding the development of adequate management and protective strategies.
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Affiliation(s)
- Emily L Vernon
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
| | - Tim P Bean
- Cefas Weymouth Laboratory, Barrack Road, The Nothe, Weymouth, Dorset, DT4 8UB, UK
| | - Awadhesh N Jha
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.
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Becquer A, Garcia K, Amenc L, Rivard C, Doré J, Trives-Segura C, Szponarski W, Russet S, Baeza Y, Lassalle-Kaiser B, Gay G, Zimmermann SD, Plassard C. The Hebeloma cylindrosporum HcPT2 Pi transporter plays a key role in ectomycorrhizal symbiosis. New Phytol 2018; 220:1185-1199. [PMID: 29944179 DOI: 10.1111/nph.15281] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 05/28/2018] [Indexed: 05/23/2023]
Abstract
Through a mutualistic relationship with woody plant roots, ectomycorrhizal fungi provide growth-limiting nutrients, including inorganic phosphate (Pi), to their host. Reciprocal trades occur at the Hartig net, which is the symbiotic interface of ectomycorrhizas where the two partners are symplasmically isolated. Fungal Pi must be exported to the symbiotic interface, but the proteins facilitating this transfer are unknown. In the present study, we combined transcriptomic, microscopy, whole plant physiology, X-ray fluorescence mapping, 32 P labeling and fungal genetic approaches to unravel the role of HcPT2, a fungal Pi transporter, during the Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizal association. We localized HcPT2 in the extra-radical hyphae and the Hartig net and demonstrated its determinant role for both the establishment of ectomycorrhizas and Pi allocation towards P. pinaster. We showed that the host plant induces HcPT2 expression and that the artificial overexpression of HcPT2 is sufficient to significantly enhance Pi export towards the central cylinder. Together, our results reveal that HcPT2 plays an important role in ectomycorrhizal symbiosis, affecting both Pi influx in the mycelium and efflux towards roots under the control of P. pinaster.
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Affiliation(s)
- Adeline Becquer
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
| | - Kevin Garcia
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, 57007, USA
- BPMP, Université de Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Laurie Amenc
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
| | - Camille Rivard
- CEPIA, INRA, 44300, Nantes, France
- Synchrotron SOLEIL, 91190, Gif-sur-Yvette, France
| | - Jeanne Doré
- LEM, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 69622, Villeurbanne, France
| | - Carlos Trives-Segura
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
| | - Wojciech Szponarski
- BPMP, Université de Montpellier, CNRS, INRA, SupAgro, 34060, Montpellier, France
| | - Sylvie Russet
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
| | - Yoan Baeza
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
| | | | - Gilles Gay
- LEM, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 69622, Villeurbanne, France
| | | | - Claude Plassard
- Eco & Sols, Université de Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, 34060, Montpellier, France
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Tian L, Yi X, Dong Z, Xu J, Liang C, Chao Y, Wang Y, Yang K, Liu Z. Calcium Bisphosphonate Nanoparticles with Chelator-Free Radiolabeling to Deplete Tumor-Associated Macrophages for Enhanced Cancer Radioisotope Therapy. ACS Nano 2018; 12:11541-11551. [PMID: 30359515 DOI: 10.1021/acsnano.8b06699] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Tumor-associated macrophages (TAMs) are often related with poor prognosis after radiotherapy. Depleting TAMs may thus be a promising method to improve the radio-therapeutic efficacy. Herein, we report a biocompatible and biodegradable nanoplatform based on calcium bisphosphonate (CaBP-PEG) nanoparticles for chelator-free radiolabeling chemistry, effective in vivo depletion of TAMs, and imaging-guided enhanced cancer radioisotope therapy (RIT). It is found that CaBP-PEG nanoparticles prepared via a mineralization method with poly(ethylene glycol) (PEG) coating could be labeled with various radioisotopes upon simple mixing, including gamma-emitting 99mTc for single-photon-emission computed tomography (SPECT) imaging, as well as beta-emitting 32P as a therapeutic radioisotope for RIT. Upon intravenous injection, CaBP(99mTc)-PEG nanoparticles exhibit efficient tumor homing, as evidenced by SPECT imaging. Owning to the function of bisphosphonates as clinical drugs to deplete TAMs, suppressed angiogenesis, normalized tumor vasculatures, enhanced intratumoral perfusion, and relieved tumor hypoxia are observed after TAM depletion induced by CaBP-PEG. Such modulated tumor microenvironment appears to be highly favorable for cancer RIT using CaBP(32P)-PEG as the radio-therapeutic agent, which offers excellent synergistic therapeutic effect in inhibiting the tumor growth. With great biocompatibility and multifunctionalities, such CaBP-PEG nanoparticles constituted by Ca2+ and a clinical drug would be rather attractive for clinical translation.
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Affiliation(s)
- Longlong Tian
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Xuan Yi
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Ziliang Dong
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Jun Xu
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Chao Liang
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Yu Chao
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Yaxing Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Kai Yang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , Jiangsu 215123 , China
| | - Zhuang Liu
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou , Jiangsu 215123 , China
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Slama K, Galliot A, Weichmann F, Hertler J, Feederle R, Meister G, Helm M. Determination of enrichment factors for modified RNA in MeRIP experiments. Methods 2018; 156:102-109. [PMID: 30394295 DOI: 10.1016/j.ymeth.2018.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
In the growing field of RNA modification, precipitation techniques using antibodies play an important role. However, little is known about their specificities and protocols are missing to assess their effectiveness. Here we present a method to assess enrichment factors after MeRIP-type pulldown experiments, here exemplified with a commercial antibody against N6-methyladenosine (m6A). Testing different pulldown and elution conditions, we measure enrichment factors of 4-5 using m6A-containing mRNAs against an unmodified control of identical sequence. Both types of mRNA carry 32P labels at different nucleotides, allowing their relative quantification in a mixture after digestion to nucleotides, separation by TLC and quantitative phosphorimaging of the labels.
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Affiliation(s)
- Kaouthar Slama
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany
| | - Aurellia Galliot
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany
| | - Franziska Weichmann
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Jasmin Hertler
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany
| | - Regina Feederle
- Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility and Research Group, Munich, Germany
| | - Gunter Meister
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany.
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Abstract
This protocol describes how to use northern hybridization to detect 15- to 150-nt small RNAs. Total RNA is fractionated by electrophoresis through a denaturing polyacrylamide gel and then transferred to a nylon membrane by semidry electroblotting. After UV-cross-linking the RNA to the membrane, hybridization is performed in Church buffer using a 32P-radiolabeled oligonucleotide probe followed by PhosphorImager analysis. The use of StarFire probes allows a substantial increase in the specific radioactivity of the hybridization probe. StarFire probes contain two domains. The target-specific domain at the 5' end hybridizes to the small RNA of interest. The universal template-binding domain at the 3' end is used to bind a universal template oligonucleotide that carries 10 deoxythymidines at its 5' end, providing a template for DNA polymerase to incorporate 10 [α-32P]deoxyadenosines at the 3' end of the StarFire probe.
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Ackerman NL, Boschi F, Spinelli AE. Monte Carlo simulations support non-Cerenkov radioluminescence production in tissue. J Biomed Opt 2017; 22:1-11. [PMID: 28819962 DOI: 10.1117/1.jbo.22.8.086002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 05/16/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
There is experimental evidence for the production of non-Cerenkov radioluminescence in a variety of materials, including tissue. We constructed a Geant4 Monte Carlo simulation of the radiation from P32 and Tc99m interacting in chicken breast and used experimental imaging data to model a scintillation-like emission. The same radioluminescence spectrum is visible from both isotopes and cannot otherwise be explained through fluorescence or filter miscalibration. We conclude that chicken breast has a near-infrared scintillation-like response with a light yield three orders of magnitude smaller than BGO.
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Affiliation(s)
- Nicole L Ackerman
- Agnes Scott College, Department of Physics and Astronomy, Decatur, Georgia, United States
| | - Federico Boschi
- University of Verona, Department of Computer Science, Verona, Italy
| | - Antonello E Spinelli
- San Raffaele Scientific Institute, Centre for Experimental Imaging, Department of Medical Physics, M, Italy
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12
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Rackayova V, Braissant O, McLin VA, Berset C, Lanz B, Cudalbu C. 1H and 31P magnetic resonance spectroscopy in a rat model of chronic hepatic encephalopathy: in vivo longitudinal measurements of brain energy metabolism. Metab Brain Dis 2016; 31:1303-1314. [PMID: 26253240 DOI: 10.1007/s11011-015-9715-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/26/2015] [Indexed: 12/21/2022]
Abstract
Chronic liver disease (CLD) leads to a spectrum of neuropsychiatric disorders named hepatic encephalopathy (HE). Even though brain energy metabolism is believed to be altered in chronic HE, few studies have explored energy metabolism in CLD-induced HE, and their findings were inconsistent. The aim of this study was to characterize for the first time in vivo and longitudinally brain metabolic changes in a rat model of CLD-induced HE with a focus on energy metabolism, using the methodological advantages of high field proton and phosphorus Magnetic Resonance Spectroscopy (1H- and 31P-MRS). Wistar rats were bile duct ligated (BDL) and studied before BDL and at post-operative weeks 4 and 8. Glutamine increased linearly over time (+146 %) together with plasma ammonium (+159 %). As a compensatory effect, other brain osmolytes decreased: myo-inositol (-36 %), followed by total choline and creatine. A decrease in the neurotransmitters glutamate (-17 %) and aspartate (-28 %) was measured only at week 8, while no significant changes were observed for lactate and phosphocreatine. Among the other energy metabolites measured by 31P-MRS, we observed a non-significant decrease in ATP together with a significant decrease in ADP (-28 %), but only at week 8 after ligation. Finally, brain glutamine showed the strongest correlations with changes in other brain metabolites, indicating its importance in type C HE. In conclusion, mild alterations in some metabolites involved in energy metabolism were observed but only at the end stage of the disease when edema and neurological changes are already present. Therefore, our data indicate that impaired energy metabolism is not one of the major causes of early HE symptoms in the established model of type C HE.
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Affiliation(s)
- Veronika Rackayova
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Olivier Braissant
- Service of Biomedicine, University Hospital of Lausanne, Lausanne, Switzerland
| | - Valérie A McLin
- Swiss Center for Liver Disease in Children, Department of Pediatrics, University Hospitals Geneva, Geneva, Switzerland
| | - Corina Berset
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bernard Lanz
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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13
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14
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Sevcenco AM, Paravidino M, Vrouwenvelder JS, Wolterbeek HT, van Loosdrecht MCM, Hagen WR. Phosphate and arsenate removal efficiency by thermostable ferritin enzyme from Pyrococcus furiosus using radioisotopes. Water Res 2015; 76:181-186. [PMID: 25817554 DOI: 10.1016/j.watres.2015.02.054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [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: 10/08/2014] [Revised: 02/22/2015] [Accepted: 02/23/2015] [Indexed: 06/04/2023]
Abstract
Oxo-anion binding properties of the thermostable enzyme ferritin from Pyrococcus furiosus were characterized with radiography. Radioisotopes (32)P and (76)As present as oxoanions were used to measure the extent and the rate of their absorption by the ferritin. Thermostable ferritin proved to be an excellent system for rapid phosphate and arsenate removal from aqueous solutions down to residual concentrations at the picomolar level. These very low concentrations make thermostable ferritin a potential tool to considerably mitigate industrial biofouling by phosphate limitation or to remove arsenate from drinking water.
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Affiliation(s)
- Ana-Maria Sevcenco
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands; Department of Radiation, Radionuclides and Reactors, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands; BiAqua B.V., Schipholweg 275, 1171 PK Badhoevedorp, The Netherlands
| | | | - Johannes S Vrouwenvelder
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands; King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal, Saudi Arabia
| | - Hubert Th Wolterbeek
- Department of Radiation, Radionuclides and Reactors, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Wilfred R Hagen
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
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15
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16
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Mölling K, Bolognesi DP, Bauer H, Büsen W, Plassmann HW, Hausen P. Association of the viral reverse transcriptase with an enzyme degrading the RNA moiety of RNA-DNA hybrids. Bibl Haematol 2015; 39:536-50. [PMID: 4130400 DOI: 10.1159/000427884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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17
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Abstract
Nonlamellar lipid membranes are frequently induced by proteins that fuse, bend, and cut membranes. Understanding the mechanism of action of these proteins requires the elucidation of the membrane morphologies that they induce. While hexagonal phases and lamellar phases are readily identified by their characteristic solid-state NMR line shapes, bicontinuous lipid cubic phases are more difficult to discern, since the static NMR spectra of cubic-phase lipids consist of an isotropic (31)P or (2)H peak, indistinguishable from the spectra of isotropic membrane morphologies such as micelles and small vesicles. To date, small-angle X-ray scattering is the only method to identify bicontinuous lipid cubic phases. To explore unique NMR signatures of lipid cubic phases, we first describe the orientation distribution of lipid molecules in cubic phases and simulate the static (31)P chemical shift line shapes of oriented cubic-phase membranes in the limit of slow lateral diffusion. We then show that (31)P T2 relaxation times differ significantly between isotropic micelles and cubic-phase membranes: the latter exhibit 2 orders of magnitude shorter T2 relaxation times. These differences are explained by the different time scales of lipid lateral diffusion on the cubic-phase surface versus the time scales of micelle tumbling. Using this relaxation NMR approach, we investigated a DOPE membrane containing the transmembrane domain (TMD) of a viral fusion protein. The static (31)P spectrum of DOPE shows an isotropic peak, whose T2 relaxation times correspond to that of a cubic phase. Thus, the viral fusion protein TMD induces negative Gaussian curvature, which is an intrinsic characteristic of cubic phases, to the DOPE membrane. This curvature induction has important implications to the mechanism of virus-cell fusion. This study establishes a simple NMR diagnostic probe of lipid cubic phases, which is expected to be useful for studying many protein-induced membrane remodeling phenomena in biology.
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Affiliation(s)
- Yu Yang
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139, United States
| | - Hongwei Yao
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139, United States
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139, United States
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18
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Bolognesi DP, Obara T. Minor RNA and other components of host origin intrinsic to avian leukosis virus particles. Bibl Haematol 2015:126-39. [PMID: 4376356 DOI: 10.1159/000391700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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19
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Dhar G, Sen S, Chaudhuri G. Acid gradient across plasma membrane can drive phosphate bond synthesis in cancer cells: acidic tumor milieu as a potential energy source. PLoS One 2015; 10:e0124070. [PMID: 25874623 PMCID: PMC4398327 DOI: 10.1371/journal.pone.0124070] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/25/2015] [Indexed: 01/20/2023] Open
Abstract
Aggressive cancers exhibit an efficient conversion of high amounts of glucose to lactate accompanied by acid secretion, a phenomenon popularly known as the Warburg effect. The acidic microenvironment and the alkaline cytosol create a proton-gradient (acid gradient) across the plasma membrane that represents proton-motive energy. Increasing experimental data from physiological relevant models suggest that acid gradient stimulates tumor proliferation, and can also support its energy needs. However, direct biochemical evidence linking extracellular acid gradient to generation of intracellular ATP are missing. In this work, we demonstrate that cancer cells can synthesize significant amounts of phosphate-bonds from phosphate in response to acid gradient across plasma membrane. The noted phenomenon exists in absence of glycolysis and mitochondrial ATP synthesis, and is unique to cancer. Biochemical assays using viable cancer cells, and purified plasma membrane vesicles utilizing radioactive phosphate, confirmed phosphate-bond synthesis from free phosphate (Pi), and also localization of this activity to the plasma membrane. In addition to ATP, predominant formation of pyrophosphate (PPi) from Pi was also observed when plasma membrane vesicles from cancer cells were subjected to trans-membrane acid gradient. Cancer cytosols were found capable of converting PPi to ATP, and also stimulate ATP synthesis from Pi from the vesicles. Acid gradient created through glucose metabolism by cancer cells, as observed in tumors, also proved critical for phosphate-bond synthesis. In brief, these observations reveal a role of acidic tumor milieu as a potential energy source and may offer a novel therapeutic target.
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Affiliation(s)
- Gautam Dhar
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA, 90095-1740, United States of America
- * E-mail: (GD); (GC)
| | - Suvajit Sen
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA, 90095-1740, United States of America
- Jonsson Comprehensive Cancer Center, Los Angeles, CA, United States of America
| | - Gautam Chaudhuri
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA, 90095-1740, United States of America
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA, 90095-1740, United States of America
- Jonsson Comprehensive Cancer Center, Los Angeles, CA, United States of America
- * E-mail: (GD); (GC)
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20
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Yu W, Neckles C, Chang A, Bommineni GR, Spagnuolo L, Zhang Z, Liu N, Lai C, Truglio J, Tonge PJ. A [(32)P]NAD(+)-based method to identify and quantitate long residence time enoyl-acyl carrier protein reductase inhibitors. Anal Biochem 2015; 474:40-9. [PMID: 25684450 PMCID: PMC4454744 DOI: 10.1016/j.ab.2014.12.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/30/2014] [Accepted: 12/31/2014] [Indexed: 01/26/2023]
Abstract
The classical methods for quantifying drug-target residence time (tR) use loss or regain of enzyme activity in progress curve kinetic assays. However, such methods become imprecise at very long residence times, mitigating the use of alternative strategies. Using the NAD(P)H-dependent FabI enoyl-acyl carrier protein (enoyl-ACP) reductase as a model system, we developed a Penefsky column-based method for direct measurement of tR, where the off-rate of the drug was determined with radiolabeled [adenylate-(32)P]NAD(P(+)) cofactor. In total, 23 FabI inhibitors were analyzed, and a mathematical model was used to estimate limits to the tR values of each inhibitor based on percentage drug-target complex recovery following gel filtration. In general, this method showed good agreement with the classical steady-state kinetic methods for compounds with tR values of 10 to 100 min. In addition, we were able to identify seven long tR inhibitors (100-1500 min) and to accurately determine their tR values. The method was then used to measure tR as a function of temperature, an analysis not previously possible using the standard kinetic approach due to decreased NAD(P)H stability at elevated temperatures. In general, a 4-fold difference in tR was observed when the temperature was increased from 25 to 37 °C.
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Affiliation(s)
- Weixuan Yu
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Carla Neckles
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Andrew Chang
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Gopal Reddy Bommineni
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Lauren Spagnuolo
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Zhuo Zhang
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Nina Liu
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA
| | - Christina Lai
- Great Neck South High School, Great Neck, NY 11020, USA
| | - James Truglio
- Great Neck South High School, Great Neck, NY 11020, USA
| | - Peter J Tonge
- Institute of Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA.
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21
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Abstract
Construction of long RNAs can be achieved in vitro by using ribozymes to recombine shorter RNAs. This can be a useful technique to prepare RNAs when the final product is either very long or contains chemical modifications that are difficult to incorporate using standard in vitro transcription techniques. Here, we describe the use of the Azoarcus group I intron ribozyme to recombine shorter RNAs into longer ones. This ribozyme is a generalized RNA recombinase ribozyme that operates rapidly and with high efficiency.
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Affiliation(s)
- Niles Lehman
- Department of Chemistry, Portland State University, 751, Portland, OR, 97207, USA,
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22
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Maki H, Tsujito M, Nariai H, Mizuhata M. ⁹Be and ³¹P NMR analyses on the influence of imino groups on Be²⁺ complex stabilities of a series of cyclo-μ-imido triphosphate anions. Magn Reson Chem 2014; 52:69-81. [PMID: 25289393 DOI: 10.1002/mrc.4037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The complexation behaviors of Be²⁺ with cyclo-μ-imido triphosphate anions, cP₃O₉-n(NH)n(3-)n= 1, 2),have been investigated by both ⁹Be and ³¹P NMR techniques at -2.3 °C in order to clarify the coordination structures of the complexes. The spectra showed that cP₃O₉n(NH)n (n = 1, 2) ligands form ML, ML₂, and M₂L complexes with Be²⁺ ions, and the formation of complexes coordinating with nitrogen atoms of the cyclic framework in the ligand molecule has been excluded. These complexation trends are very similar to those of Be²⁺-cP₃O₆(NH)⁻³₃system, which has been reported by us. The peak deconvolution of ⁹BeNMR spectra made these beryllium complexes amenable to stability constant determinations. The stability constants of the complexes increase with an increase in the protonation constants of the ligands as the number of imino groups, which constitute the ligand molecules, is ascended. This increase is primarily attributable to the lower electronegativity of nitrogen atoms than oxygen atoms, which are directly bonded to central phosphorus atoms; moreover, tautomerism equilibrium in the entire of the imidopolyphosphate molecule is also responsible to the higher basicity. ³¹P NMR spectra measured concurrently have verified the formation of the complexes estimated by the ⁹Be NMR measurement. Intrinsic ³¹P NMR chemical shift values of the phosphorus atoms belonging to ligand molecules complexed with Be²⁺ cations have been determined. Not only the protonation constants but also the stability constants of all Be²⁺ complexes increase approximately linearly with an increase in the number of imino groups.
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Affiliation(s)
- Hideshi Maki
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1–1 Rokkodai-cho, Nada-ku, Kobe 657–8501, Japan.
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23
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Abstract
In eukaryotes, many RNA species are transcribed, processed in the nucleus, and exported to the cytoplasm, where they are destined to function or to be further matured. Some RNAs are even reimported to the nucleus. In addition, many RNAs are localized at specific nuclear bodies before their export and/or after their nuclear reimport. To understand how RNAs are transported, Xenopus oocytes are extremely useful cells, thanks to their large size. RNA transport can be easily examined by microinjecting radioactively or fluorescently labeled RNAs into Xenopus oocytes. Mammalian cultured cells are sometimes useful by virtue of RNA-FISH technique. Here, we describe methods to analyze RNA localization and export using these cells.
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Affiliation(s)
| | - Asako McCloskey
- Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Mutsuhito Ohno
- Institute for Virus Research, Kyoto University, Kyoto, Japan
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24
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Phillips AC, Sleigh A, McAllister CJ, Brage S, Carpenter TA, Kemp GJ, Holland AJ. Defective mitochondrial function in vivo in skeletal muscle in adults with Down's syndrome: a 31P-MRS study. PLoS One 2013; 8:e84031. [PMID: 24391872 PMCID: PMC3877137 DOI: 10.1371/journal.pone.0084031] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/11/2013] [Indexed: 01/11/2023] Open
Abstract
Down's syndrome (DS) is a developmental disorder associated with intellectual disability (ID). We have previously shown that people with DS engage in very low levels of exercise compared to people with ID not due to DS. Many aspects of the DS phenotype, such as dementia, low activity levels and poor muscle tone, are shared with disorders of mitochondrial origin, and mitochondrial dysfunction has been demonstrated in cultured DS tissue. We undertook a phosphorus magnetic resonance spectroscopy ((31)P-MRS) study in the quadriceps muscle of 14 people with DS and 11 non-DS ID controls to investigate the post-exercise resynthesis kinetics of phosphocreatine (PCr), which relies on mitochondrial respiratory function and yields a measure of muscle mitochondrial function in vivo. We found that the PCr recovery rate constant was significantly decreased in adults with DS compared to non-DS ID controls (1.7 ± 0.1 min(-1) vs 2.1 ± 0.1 min(-1) respectively) who were matched for physical activity levels, indicating that muscle mitochondrial function in vivo is impaired in DS. This is the first study to investigate mitochondrial function in vivo in DS using (31)P-MRS. Our study is consistent with previous in vitro studies, supporting a theory of a global mitochondrial defect in DS.
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Affiliation(s)
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | | | - Soren Brage
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - T. Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Graham J. Kemp
- Department of Musculoskeletal Biology, University of Liverpool, Liverpool, United Kingdom
| | - Anthony J. Holland
- Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
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25
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Phillips DH. On the origins and development of the (32)P-postlabelling assay for carcinogen-DNA adducts. Cancer Lett 2013; 334:5-9. [PMID: 23178450 DOI: 10.1016/j.canlet.2012.11.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 11/19/2022]
Abstract
The (32)P-postlabelling method for the analysis of carcinogen-DNA adducts originated 30years ago from Baylor College of Medicine in Houston and was the work of a team comprised of Kurt and Erica Randerath, Ramesh Gupta and Vijay Reddy. With subsequent modifications and developments, it has become a highly sensitive and versatile method for the detection of DNA adducts that has been applied in a wide range of human, animal and in vitro studies. These include monitoring human exposure to environmental and occupational carcinogens, investigating genotoxicity of chemicals, elucidating pathways of metabolic activation of carcinogens, mechanistic studies of DNA repair, analysing the genotoxicity of complex mixtures and in ecotoxicology studies. Its use has been instrumental in providing new clues to the aetiology of some cancers and in identifying a new human carcinogen.
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Affiliation(s)
- David H Phillips
- King's College London, Analytical and Environmental Sciences Division, MRC-HPA Centre for Environment and Health, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
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26
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Ludewig G, Robertson LW. Polychlorinated biphenyls (PCBs) as initiating agents in hepatocellular carcinoma. Cancer Lett 2013; 334:46-55. [PMID: 23211541 PMCID: PMC3648605 DOI: 10.1016/j.canlet.2012.11.041] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 11/20/2012] [Accepted: 11/25/2012] [Indexed: 12/11/2022]
Abstract
PCBs are carcinogens, but for many decades it was assumed that PCBs may not possess initiating activity. Initiation is a process that involves changes in the DNA sequence, often, but not exclusively produced through DNA adduction by a reactive compound or reactive oxygen species (ROS). DNA adducts can be detected by (32)P-postlabeling, a method that Dr. Ramesh Gupta co-developed and refined. Today these types of assays together with other mechanistic studies provide convincing evidence that specific PCB congeners can be biotransformed to genotoxic and therefore potentially initiating metabolites. This review will provide an overview of our current knowledge of PCBs' genotoxic potential and mechanism of action, emphasizing the contributions of Dr. Ramesh Gupta during his tenures at the Universities of Kentucky and Louisville.
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Affiliation(s)
- Gabriele Ludewig
- The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA 52242-5000, United States.
| | - Larry W Robertson
- The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA 52242-5000, United States
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27
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Van Moorleghem C, De Schutter N, Smolders E, Merckx R. Bioavailability of organic phosphorus to Pseudokirchneriella subcapitata as affected by phosphorus starvation: an isotope dilution study. Water Res 2013; 47:3047-3056. [PMID: 23561496 DOI: 10.1016/j.watres.2013.03.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/06/2013] [Accepted: 03/09/2013] [Indexed: 06/02/2023]
Abstract
Phosphorus (P) starved algae have a capacity to rapidly take up P when resupplied to P. This study was set-up to measure to what extent P starvation enhances the potential of algae to utilize organic P forms. The initial (<0.5 h) PO4 uptake rates of cells of Pseudokirchneriella subcapitata increased up to 18-fold with increasing starvation. Algae from different levels of P starvation were subsequently exposed to different model organic P forms and carrier-free (33)PO4. Uptake (1h) of P from organic P-increased up to 5-fold with increasing P starvation. The bioavailability of organic P, relative to PO4, was calculated from uptake of (31)P and (33)P isotopes assuming no isotopic exchange with organic P-forms. This relative bioavailability ranged from 0 to 57% and remained generally unaffected by the extent of P-starvation. This result was found for cells that were either or not treated by a wash method to remove extracellular phosphatases. Short-term P uptake rate sharply increases with decreasing internal P content of the algal cells but the bioavailability of organic P, relative to PO4, is not enhanced. Such finding suggests that P-starvation enhances PO4 uptake capacity and organic P hydrolysis capacity to about the same extent.
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Affiliation(s)
- Christoff Van Moorleghem
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium.
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28
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Shah NJ, Oros-Peusquens AM, Arrubla J, Zhang K, Warbrick T, Mauler J, Vahedipour K, Romanzetti S, Felder J, Celik A, Rota-Kops E, Iida H, Langen KJ, Herzog H, Neuner I. Advances in multimodal neuroimaging: hybrid MR-PET and MR-PET-EEG at 3 T and 9.4 T. J Magn Reson 2013; 229:101-115. [PMID: 23317760 DOI: 10.1016/j.jmr.2012.11.027] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 11/28/2012] [Accepted: 11/29/2012] [Indexed: 06/01/2023]
Abstract
Multi-modal MR-PET-EEG data acquisition in simultaneous mode confers a number of advantages at 3 T and 9.4 T. The three modalities complement each other well; structural-functional imaging being the domain of MRI, molecular imaging with specific tracers is the strength of PET, and EEG provides a temporal dimension where the other two modalities are weak. The utility of hybrid MR-PET at 3 T in a clinical setting is presented and critically discussed. The potential problems and the putative gains to be accrued from hybrid imaging at 9.4 T, with examples from the human brain, are outlined. Steps on the road to 9.4 T multi-modal MR-PET-EEG are also illustrated. From an MR perspective, the potential for ultra-high resolution structural imaging is discussed and example images of the cerebellum with an isotropic resolution of 320 μm are presented, setting the stage for hybrid imaging at ultra-high field. Further, metabolic imaging is discussed and high-resolution images of the sodium distribution are presented. Examples of tumour imaging on a 3 T MR-PET system are presented and discussed. Finally, the perspectives for multi-modal imaging are discussed based on two on-going studies, the first comparing MR and PET methods for the measurement of perfusion and the second which looks at tumour delineation based on MRI contrasts but the knowledge of tumour extent is based on simultaneously acquired PET data.
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Affiliation(s)
- N Jon Shah
- Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich, Germany.
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29
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Shircliff RA, Stradins P, Moutinho H, Fennell J, Ghirardi ML, Cowley SW, Branz HM, Martin IT. Angle-resolved XPS analysis and characterization of monolayer and multilayer silane films for DNA coupling to silica. Langmuir 2013; 29:4057-4067. [PMID: 23445373 DOI: 10.1021/la304719y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We measure silane density and Sulfo-EMCS cross-linker coupling efficiency on aminosilane films by high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. We then characterize DNA immobilization and hybridization on these films by (32)P-radiometry. We find that the silane film structure controls the efficiency of the subsequent steps toward DNA hybridization. A self-limited silane monolayer produced from 3-aminopropyldimethylethoxysilane (APDMES) provides a silane surface density of ~3 nm(-2). Thin (1 h deposition) and thick (19 h deposition) multilayer films are generated from 3-aminopropyltriethoxysilane (APTES), resulting in surfaces with increased roughness compared to the APDMES monolayer. Increased silane surface density is estimated for the 19 h APTES film, due to a ∼32% increase in surface area compared to the APDMES monolayer. High cross-linker coupling efficiencies are measured for all three silane films. DNA immobilization densities are similar for the APDMES monolayer and 1 h APTES. However, the DNA immobilization density is double for the 19 h APTES, suggesting that increased surface area allows for a higher probe attachment. The APDMES monolayer has the lowest DNA target density and hybridization efficiency. This is attributed to the steric hindrance as the random packing limit is approached for DNA double helices (dsDNA, diameter ≥ 2 nm) on a plane. The heterogeneity and roughness of the APTES films reduce this steric hindrance and allow for tighter packing of DNA double helices, resulting in higher hybridization densities and efficiencies. The low steric hindrance of the thin, one to two layer APTES film provides the highest hybridization efficiency of nearly 88%, with 0.21 dsDNA/nm(2). The XPS data also reveal water on the cross-linker-treated surface that is implicated in device aging.
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Affiliation(s)
- Rebecca A Shircliff
- Chemistry and Geochemistry Department, Colorado School of Mines, Golden, Colorado 80401, United States
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30
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Russo-Abrahão T, Alves-Bezerra M, Majerowicz D, Freitas-Mesquita AL, Dick CF, Gondim KC, Meyer-Fernandes JR. Transport of inorganic phosphate in Leishmania infantum and compensatory regulation at low inorganic phosphate concentration. Biochim Biophys Acta 2013; 1830:2683-2689. [PMID: 23671929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Proliferation of Leishmania infantum depends on exogenous inorganic phosphate (P(i)) but little is known about energy metabolism and transport of P(i) across the plasma membrane in Leishmania sp. METHODS We investigated the kinetics of 32P(i) transport, the influence of H+ and K+ ionophores and inhibitors, and expression of the genes for the Na+:P(i) and H+:P(i) cotransporters. RESULTS The proton ionophore FCCP, bafilomycin A1 (vacuolar ATPase inhibitor), nigericin (K+ ionophore) and SCH28080 (an inhibitor of H+, K(+)-ATPase) all inhibited the transport of P(i). This transport showed Michaelis-Menten kinetics with K0.5 and V(max) values of 0.016 +/- 0.002 mM and 564.9 +/- 18.06 pmol x h(-1) x 10(-7) cells, respectively. These values classify the P(i) transporter of L. infantum among the high-affinity transporters, a group that includes Pho84 of Saccharomyces cerevisiae. Two sequences were identified in the L. infantum genome that code for phosphate transporters. However, transcription of the PHO84 transporter was 10-fold higher than the PHO89 transporter in this parasite. Accordingly, P(i) transport and LiPho84 gene expression were modulated by environmental P(i) variations. CONCLUSIONS These findings confirm the presence of a P(i) transporter in L. infantum, similar to PHO84 in S. cerevisiae, that contributes to the acquisition of inorganic phosphate and could be involved in growth and survival of the promastigote forms of L. infantum. GENERAL SIGNIFICANCE This work provides the first description of a PHO84-like P(i) transporter in a Trypanosomatide parasite of the genus Leishmania, responsible for many infections worldwide.
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Affiliation(s)
- T Russo-Abrahão
- Instituto de Microbiologia Professor Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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31
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Abstract
Bacterial signaling networks control a wide variety of cellular processes including growth, metabolism, and pathogenesis. Bis-(3'-5')-cyclic dimeric guanosine monophosphate (cdiGMP) is a secondary signaling nucleotide that controls cellulose synthesis, biofilm formation, motility and virulence in a wide range of gram-negative bacterial species. CdiGMP is a dynamic molecule that forms different tertiary structures in vitro, including a trans-monomer, cis-monomer, cis-dimer and G-octaplex (G8). Although the monomer and dimer have been shown to be physiologically relevant in modulating protein activity and transcription, the biological effects of the cdiGMP G8 has not yet been described. Here, we have developed a TLC-based assay to detect radiolabeled cdiGMP G8 formation. Utilizing the radiolabeled cdiGMP G8, we have also shown a novel inhibitory interaction between the cdiGMP G8 and HIV-1 reverse transcriptase and that the cdiGMP G8 does not interact with proteins from Pseudomonas aeruginosa known to bind monomeric and dimeric cdiGMP. These results suggest that the radiolabeled cdiGMP G8 can be used to measure interactions between the cdiGMP G8 and cellular proteins, providing an avenue through which the biological significance of this molecule could be investigated.
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Affiliation(s)
- Ori J. Lieberman
- Department of Cell Biology and Molecular Genetics, University of Maryland at College Park, College Park, Maryland, United States of America
- Maryland Pathogen Research Institute, College Park, Maryland, United States of America
| | - Jeffery J. DeStefano
- Department of Cell Biology and Molecular Genetics, University of Maryland at College Park, College Park, Maryland, United States of America
- Maryland Pathogen Research Institute, College Park, Maryland, United States of America
| | - Vincent T. Lee
- Department of Cell Biology and Molecular Genetics, University of Maryland at College Park, College Park, Maryland, United States of America
- Maryland Pathogen Research Institute, College Park, Maryland, United States of America
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32
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Abstract
In plants, phosphatidic acid (PA) functions as a metabolic precursor in the biosynthesis of glycerolipids, but it also acts as a key signaling lipid in the response to environmental stress conditions (Testerink and Munnik, J Exp Bot 62:2349-2361, 2011). In vivo (32)P-radiolabeling assays have shown the level of PA to increase within seconds/minutes of exposure to a stimulus. This response can be due to the activity of diacylglycerol kinase (DGK) and/or phospholipase D (PLD). A method is described to investigate which of the pathways is responsible for PA accumulation under a particular stress condition. First, a differential (32)P-radiolabeling protocol is used to discriminate (32)P-PA pools that are rapidly labeled versus those requiring long prelabeling times, reflecting DGK and PLD activities, respectively. Second, to specifically monitor the contribution of PLD, a transphosphatidylation assay is applied, which makes use of the artificial lipid phosphatidylbutanol as an in vivo marker of PLD activity.
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Affiliation(s)
- Steven A Arisz
- Swammerdam Institute for Life Sciences, Section Plant Physiology, University of Amsterdam, Amsterdam, The Netherlands
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33
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Nath K, Nelson DS, Ho A, Lee SC, Darpolor MM, Pickup S, Zhou R, Heitjan DF, Leeper DB, Glickson JD. (31) P and (1) H MRS of DB-1 melanoma xenografts: lonidamine selectively decreases tumor intracellular pH and energy status and sensitizes tumors to melphalan. NMR Biomed 2013; 26:98-105. [PMID: 22745015 PMCID: PMC3465621 DOI: 10.1002/nbm.2824] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 04/11/2012] [Accepted: 04/24/2012] [Indexed: 05/17/2023]
Abstract
In vivo (31) P MRS demonstrates that human melanoma xenografts in immunosuppressed mice treated with lonidamine (LND, 100 mg/kg intraperitoneally) exhibit a decrease in intracellular pH (pH(i) ) from 6.90 ± 0.05 to 6.33 ± 0.10 (p < 0.001), a slight decrease in extracellular pH (pH(e) ) from 7.00 ± 0.04 to 6.80 ± 0.07 (p > 0.05) and a monotonic decline in bioenergetics (nucleoside triphosphate/inorganic phosphate) of 66.8 ± 5.7% (p < 0.001) relative to the baseline level. Both bioenergetics and pH(i) decreases were sustained for at least 3 h following LND treatment. Liver exhibited a transient intracellular acidification by 0.2 ± 0.1 pH units (p > 0.05) at 20 min post-LND, with no significant change in pH(e) and a small transient decrease in bioenergetics (32.9 ± 10.6%, p > 0.05) at 40 min post-LND. No changes in pH(i) or adenosine triphosphate/inorganic phosphate were detected in the brain (pH(i) , bioenergetics; p > 0.1) or skeletal muscle (pH(i) , pH(e) , bioenergetics; p > 0.1) for at least 120 min post-LND. Steady-state tumor lactate monitored by (1) H MRS with a selective multiquantum pulse sequence with Hadamard localization increased approximately three-fold (p = 0.009). Treatment with LND increased the systemic melanoma response to melphalan (LPAM; 7.5 mg/kg intravenously), producing a growth delay of 19.9 ± 2.0 days (tumor doubling time, 6.15 ± 0.31 days; log(10) cell kill, 0.975 ± 0.110; cell kill, 89.4 ± 2.2%) compared with LND alone of 1.1 ± 0.1 days and LPAM alone of 4.0 ± 0.0 days. The study demonstrates that the effects of LND on tumor pH(i) and bioenergetics may sensitize melanoma to pH-dependent therapeutics, such as chemotherapy with alkylating agents or hyperthermia.
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Affiliation(s)
| | | | - Andrew Ho
- Department of Radiology, University of Pennsylvania
| | | | | | | | - Rong Zhou
- Department of Radiology, University of Pennsylvania
| | - Daniel F. Heitjan
- Department of Biostatistics & Epidemiology, University of Pennsylvania
| | - Dennis B. Leeper
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Abstract
Automated DNA sequencing instruments embody an elegant interplay among chemistry, engineering, software, and molecular biology and have built upon Sanger's founding discovery of dideoxynucleotide sequencing to perform once-unfathomable tasks. Combined with innovative physical mapping approaches that helped to establish long-range relationships between cloned stretches of genomic DNA, fluorescent DNA sequencers produced reference genome sequences for model organisms and for the reference human genome. New types of sequencing instruments that permit amazing acceleration of data-collection rates for DNA sequencing have been developed. The ability to generate genome-scale data sets is now transforming the nature of biological inquiry. Here, I provide an historical perspective of the field, focusing on the fundamental developments that predated the advent of next-generation sequencing instruments and providing information about how these instruments work, their application to biological research, and the newest types of sequencers that can extract data from single DNA molecules.
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Affiliation(s)
- Elaine R Mardis
- The Genome Institute at Washington University School of Medicine, St. Louis, Missouri 63108, USA.
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35
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Abstract
Lipidomic analyses through LC-, GC-, and ESI-MS/MS can detect numerous lipid species based on headgroup and fatty acid compositions but usually miss the minor phospholipids involved in cell signaling because of their low chemical abundancy. Due to their high turnover, these signaling lipids are, however, readily picked up by labeling plant material with (32)P-orthophosphate and subsequent analysis of the lipid extracts by thin layer chromatography. Here, protocols are described for suspension-cultured tobacco BY-2 cells, young Arabidopsis seedlings, Vicia faba roots, and Arabidopsis leaf disks, which can easily be modified for other plant species and tissues.
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Affiliation(s)
- Teun Munnik
- Swammerdam Institute for Life Sciences, Section Plant Physiology, University of Amsterdam, Amsterdam, The Netherlands
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36
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Moghaddam MJ, Yang W, Bojarski B, Gengenbach TR, Gao M, Zareie H, McCall MJ. Azide photochemistry for facile modification of graphitic surfaces: preparation of DNA-coated carbon nanotubes for biosensing. Nanotechnology 2012; 23:425503. [PMID: 23037575 DOI: 10.1088/0957-4484/23/42/425503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A facile, two-step method for chemically attaching single-stranded DNA to graphitic surfaces, represented here by carbon nanotubes, is reported. In the first step, an azide-containing compound, N-5-azido-nitrobenzoyloxy succinimide (ANB-NOS), is used to form photo-adducts on the graphitic surfaces in a solid-state photochemical reaction, resulting in active ester groups being oriented for the subsequent reactions. In the second step, pre-synthesized DNA strands bearing a terminal amine group are coupled in an aqueous solution with the active esters on the photo-adducts. The versatility of the method is demonstrated by attaching pre-synthesized DNA to surfaces of carbon nanotubes in two platforms-as vertically-aligned multi-walled carbon nanotubes on a solid support and as tangled single-walled carbon nanotubes in mats. The reaction products at various stages were characterized by x-ray photoelectron spectroscopy. Two different assays were used to check that the DNA strands attached to the carbon nanotubes were able to bind their partner strands with complementary base sequences. The first assay, using partner DNA strands tethered to gold nanoparticles, enabled the sites of DNA attachment to the carbon nanotubes to be identified in TEM images. The second assay, using radioactively labelled partner DNA strands, quantified the density of functional DNA strands attached to the carbon nanotubes. The diversity of potential applications for these DNA-modified carbon-nanotube platforms is exemplified here by the successful use of a DNA-modified single-walled carbon-nanotube mat as an electrode for the specific detection of metal ions.
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Affiliation(s)
- Minoo J Moghaddam
- CSIRO Materials Science and Engineering, North Ryde, NSW 2113, Australia.
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37
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Wu B, Maruyama H, Teramoto M, Hogetsu T. Structural and functional interactions between extraradical mycelia of ectomycorrhizal Pisolithus isolates. New Phytol 2012; 194:1070-1078. [PMID: 22471555 DOI: 10.1111/j.1469-8137.2012.04126.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Extraradical mycelia from different ectomycorrhizal (ECM) roots coexist and interact under the forest floor. We investigated structural connections of conspecific mycelia and translocation of carbon and phosphorus between the same or different genets. Paired ECM Pinus thunbergii seedlings colonized by the same or different Pisolithus isolates were grown side by side in a rhizobox as their mycelia contacted each other. (14)CO(2) or (33)P-phosphoric acid was fed to leaves or a spot on the mycelium in one of the paired seedlings. Time-course distributions of (14)C and (33)P were visualized using a digital autoradiographic technique with imaging plates. Hyphal connections were observed between mycelia of the same Pisolithus isolate near the contact site, but hyphae did not connect between different isolates. (14)C and (33)P were translocated between mycelia of the same isolate. In (33)P-fed mycelia, accumulation of (33)P from the feeding spot toward the host ECM roots was observed. No (14)C and (33)P translocation occurred between mycelia of different isolates. These results provide direct evidence that contact and hyphal connection between mycelia of the same ECM isolate can cause nutrient translocation. The ecological significance of contact between extraradical mycelia is discussed.
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Affiliation(s)
- Bingyun Wu
- Department of Forest Sciences, Graduate School of Agricultural and Life Science, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Haruka Maruyama
- Department of Forest Sciences, Graduate School of Agricultural and Life Science, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Munemasa Teramoto
- Department of Forest Sciences, Graduate School of Agricultural and Life Science, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Taizo Hogetsu
- Department of Forest Sciences, Graduate School of Agricultural and Life Science, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
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38
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Langer T, Schlatter H, Fasold H. Evidence that the novobiocin-sensitive ATP-binding site of the heat shock protein 90 (hsp90) is necessary for its autophosphorylation. Cell Biol Int 2012; 26:653-7. [PMID: 12127946 DOI: 10.1006/cbir.2002.0882] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 90kDa heat shock protein (Hsp90) is one of the most abundant protein and essential for all eukaryotic cells. Many proteins require the interaction with Hsp90 for proper function. Upon heat stress the expression level of Hsp90 is even enhanced. It is assumed, that under these conditions Hsp90 is required to protect other proteins from aggregation. One property of Hsp90 is its ability to undergo autophosphorylation. The N-terminal domain of Hsp90 has been shown to contain an unusual ATP-binding site. A well-known inhibitor of Hsp90 function is geldanamycin binding to the N-terminal ATP-binding site with high affinity. Recently it was shown that Hsp90 possesses a second ATP-binding site in the C-terminal region, which can be competed with novobiocin. Autophosphorylation of Hsp90 was analysed by incubation with gamma(32)P-ATP. Addition of geldanamycin did not interfere with the capability for autophosphorylation, while novobiocin indeed did. These results suggest that the C-terminal ATP-binding site is required for autophosphorylation of Hsp90.
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Affiliation(s)
- T Langer
- Institut für Biochemie der Joham Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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39
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Rosilawati ML, Yasmon A. Detection of multidrug-resistant Mycobacterium tuberculosis directly from sputum samples of patients from Jakarta, Indonesia by radioisotope-based PCR-dot blot hybridization. Southeast Asian J Trop Med Public Health 2012; 43:89-95. [PMID: 23082558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The problem of eradicating tuberculosis (TB) has become more complicated by the emergence of multidrug resistant TB (MDR-TB). Any rapid laboratory method that can be used to detect drug susceptibility of Mycobacterium tuberculosis (MTB) is urgently needed. In this study, we employed the radioisotope (32P)-based PCR-dot blot hybridization method on sputum samples from patients in Jakarta, Indonesia. Bacterial DNA was extracted using BOOM method. KatG and rpobeta were amplified by PCR and katG315 or rpobeta531 mutations were identified by dot blot hybridization. Of 100 samples, 11% and 22% showed presence of mutation at codons 315 (AGC --> ACC) of katG and 531 (TCG --> TTG) of rpobeta, respectively. Five percent of the samples showed both mutations. This method is rapid, sensitive, and reliable and can be used to screen large numbers of samples in epidemiological studies.
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Affiliation(s)
- Maria Lina Rosilawati
- Center for the Application of Isotopes and Radiation Technology, National Nuclear Energy Agency, Jakarta, Indonesia.
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40
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Abstract
Northern blotting is a valuable method for detection and quantification of RNA in the field of virology. Although many methods including a various versions of polymerase chain reaction have been developed over the years, Northern blotting has been still considered as a useful and effective method for the analysis of progeny RNA accumulation for viral and subviral pathogens, such as satellite RNAs, in plant hosts. Here, we describe a detailed Northern blot protocol for efficient detection and quantification of viral and satellite RNAs from plant hosts.
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Affiliation(s)
- Sun-Jung Kwon
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA, USA
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41
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Abstract
An electrophoretic mobility shift assay (EMSA) is a common and invaluable technique which can be utilized to study the affinity of proteins to a specific DNA or RNA sequence. These assays are performed in vitro with protein extracts isolated from either cultured cells or isolated tissues. Here, we describe the methodology used to isolate the cytoplasmic and nuclear protein extracts from both cultured cells and tissues and utilize the nuclear protein fraction to assess NF-κB DNA-binding activity by EMSA analysis.
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Affiliation(s)
- Jason M Dahlman
- Department of Molecular Virology, Immunology, and Medical Genetics, Human Cancer Genetics Program, Integrated Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
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42
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Mongélard G, Seemann M, Boisson AM, Rohmer M, Bligny R, Rivasseau C. Measurement of carbon flux through the MEP pathway for isoprenoid synthesis by (31)P-NMR spectroscopy after specific inhibition of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate reductase. Effect of light and temperature. Plant Cell Environ 2011; 34:1241-7. [PMID: 21443577 DOI: 10.1111/j.1365-3040.2011.02322.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The methylerythritol 4-phosphate (MEP) and the mevalonate pathways are the unique synthesis routes for the precursors of all isoprenoids. An original mean to measure the carbon flux through the MEP pathway in plants is proposed by using cadmium as a total short-term inhibitor of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate (MEcDP) reductase (GcpE) and measuring the accumulation rate of its substrate MEcDP by (31) P-NMR spectroscopy. The MEP pathway metabolic flux was determined in spinach (Spinacia oleracea), pea (Pisum sativum), Oregon grape (Mahonia aquifolium) and boxwood (Buxus sempervirens) leaves. In spinach, flux values were compared with the synthesis rate of major isoprenoids. The flux increases with light intensity (fourfold in the 200-1200 µmol m(-2) s(-1) PPFR range) and temperature (sevenfold in the 25-37 °C range). The relationship with the light and the temperature dependency of isoprenoid production downstream of the MEP pathway is discussed.
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Affiliation(s)
- Gaëlle Mongélard
- CEA, IRTSV, Laboratoire de Physiologie Cellulaire Végétale, UMR 5168, F-38054 Grenoble, France
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43
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Spinelli AE, Kuo C, Rice BW, Calandrino R, Marzola P, Sbarbati A, Boschi F. Multispectral Cerenkov luminescence tomography for small animal optical imaging. Opt Express 2011; 19:12605-18. [PMID: 21716501 DOI: 10.1364/oe.19.012605] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Quite recently Cerenkov luminescence imaging (CLI) has been introduced as a novel pre-clinical imaging for the in vivo imaging of small animals such as mice. The CLI method is based on the detection of Cerenkov radiation (CR) generated by beta particles as they travel into the animal tissues with an energy such that Cerenkov emission condition is satisfied. This paper describes an image reconstruction method called multi spectral diffuse Cerenkov luminescence tomography (msCLT) in order to obtain 3D images from the detection of CR. The multispectral approach is based on a set of 2D planar images acquired using a number of narrow bandpass filters, and the distinctive information content at each wavelength is used in the 3D image reconstruction process. The proposed msCLT method was tested both in vitro and in vivo using 32P-ATP and all the images were acquired by using the IVIS 200 small animal optical imager (Caliper Life Sciences, Alameda USA). Source depth estimation and spatial resolution measurements were performed using a small capillary source placed between several slices of chicken breast. The theoretical Cerenkov emission spectrum and optical properties of chicken breast were used in the modelling of photon propagation. In vivo imaging was performed by injecting control nude mice with 10 MBq of 32P-ATP and the 3D tracer bio-distribution was reconstructed. Whole body MRI was acquired to provide an anatomical localization of the Cerenkov emission. The spatial resolution obtained from the msCLT reconstructed images of the capillary source showed that the FWHM is about 1.5 mm for a 6 mm depth. Co-registered MRI images showed that the Cerenkov emission regions matches fairly well with anatomical regions, such as the brain, heart and abdomen. Ex vivo imaging of the different organs such as intestine, brain, heart and ribs further confirms these findings. We conclude that in vivo 3D bio-distribution of a pure beta-minus emitting radiopharmaceutical such as 32P-ATP can be obtained using the msCLT reconstruction approach.
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Affiliation(s)
- Antonello E Spinelli
- Medical Physics Department, San Raffaele Scientific Institute, Via Olgettina N. 60, Milan, Italy.
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44
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Rosilawati ML, Yasmon A. Rapid detection of ethambutol-resistant Mycobacterium tuberculosis directly from sputum samples by radioisotope (32P)-based PCR dot blot hybridization and sequencing methods. Acta Med Indones 2011; 43:34-38. [PMID: 21339544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
AIM to develop an assay system of a radioisotope (32P)-based PCR dot-blot hybridization technique and evaluation of the assay directly for TB sputum samples to detect mutation at codon 306 of embB gene of Mycobacterium tuberculosis related with ethambutol (EMB) resistance. METHODS one hundred and sixteen of sputum samples were used in this study. Bacterial genome in sputum samples was extracted and tested for mutation at codon 306 of embB gene by the developed PCR dot blot assay using a radioisotope (32P)-labeled oligonucleotide. The positive results were confirmed by DNA sequencing. RESULTS all 116 sputum samples were PCR positive for M. tuberculosis. Of 116 samples, three (2.59%) were EMB resistant-M. tuberculosis (MTB) and showed a substitution mutation (ATG/Met'-->GTG/Val) at codon 306 of embB gene. None of mutation was detected at codon 299 of embB gene. CONCLUSION we successfully developed a radioisotope (32P)-based PCR dot blot hybridization technique for detection of mutation at codon 306 of embB gene related with EMB resistant M. tuberculosis. The assay can detect a large number of samples that is suitable for monitoring, surveillance, and epidemiology studies.
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Affiliation(s)
- Maria L Rosilawati
- Centre for Application of Isotopes and Radiation Technology, National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta, Indonesia.
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45
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46
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Funk D, Sorg BL, Lindner SC, Schmeiser HH. 32P-postlabeling analysis of DNA adducts formed by leukotriene A4 (LTA4). Environ Mol Mutagen 2010; 51:338-343. [PMID: 20120015 DOI: 10.1002/em.20547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Leukotriene A(4) (LTA(4)), a reactive electrophilic intermediate formed during the biosynthesis of inflammation-related lipid mediators, has been found to bind covalently to DNA. The major DNA adducts formed by LTA(4) in vitro and human cells have been identified by mass spectrometry on the nucleoside level. Here we investigated whether the thin-layer chromatography (TLC) (32)P-postlabeling method is suitable for the detection of LTA(4)-DNA adducts. The reaction of individual deoxynucleoside 3'-monophosphates with LTA(4) in aqueous basic solution yielded numerous adduct spots when analyzed by the two enrichment procedures of the (32)P-postlabeling method-nuclease P1 digestion and butanol extraction. Highest LTA(4)-adduct levels were found with deoxyguanosine 3'-phosphate (around one adduct per 10(4) normal nucleotides). Under similar reaction conditions LTA(4) (25-320 microM) was incubated with calf thymus DNA, then DNA adduct patterns and levels were determined with the TLC (32)P-postlabeling method using both enrichment versions. The same DNA adduct pattern consisting of up to seven spots was observed with both enrichment versions. DNA adduct formation by LTA(4) was concentration-dependent with major adducts being derived from deoxyguanosine. When a human monocytic cell line (Mono Mac 6) was stimulated with arachidonic acid and calcium ionophore LTA(4)-DNA adducts were detected by (32)P-postlabeling. However, the level of these endogenously formed DNA adducts was close to the detection limit (3 +/- 2 adducts per 10(8) normal nucleotides). In summary, the TLC (32)P-postlabeling method is suitable for studying DNA adduct formation by LTA(4) and can be used for further investigations on the link between inflammation and cancer.
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Affiliation(s)
- Dorothee Funk
- German Cancer Research Center, Division of Preventive Oncology, INF 581, 69120 Heidelberg, Germany
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Cho HJ, Cho JY, Rhee MH, Lim CR, Park HJ. Cordycepin (3‘-deoxyadenosine) inhibits human platelet aggregation induced by U46619, a TXA2 analogue. J Pharm Pharmacol 2010; 58:1677-82. [PMID: 17331333 DOI: 10.1211/jpp.58.12.0016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Cordycepin (3′-deoxyadenosine), which comes from Cordyceps militaris, the Chinese medicinal fungal genus Cordyceps, is known to have anti-tumour activity. In this study, we investigated the novel effect of cordycepin on human platelet aggregation that was induced by U46619, a thromboxane A2 (TXA2) analogue. TXA2 is an aggregation-inducing autacoidal molecule that is produced in various agonist-activated platelets. Cordycepin completely inhibited U46619-induced platelet aggregation and simultaneously reduced cytosolic free Ca2+ ([Ca2+]i), which was increased by U46619 (5 μM) up to 66%. Furthermore, the U46619-stimulated phosphorylation of Ca2+-dependent proteins (20 kDa of a myosin light chain and 47 kDa of pleckstrin) was strongly inhibited by cordycepin. These results suggest that cordycepin may have a beneficial effect on autacoidal TXA2-mediated thrombotic diseases by inhibiting TXA2-induced platelet aggregation via suppression of the Ca2+ level.
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Affiliation(s)
- Hyun Jeong Cho
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Regional Research Center, Inje University, Gimhae, Gyungnam 621-749, Korea
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Zhan HW, Liu HB, Bao CK, Ye XJ, Zhang H, He GQ. Effect of carbogen on tumour oxygenation and 32P-colloid interstitial irradiation response. Med Sci Monit 2010; 16:BR11-BR16. [PMID: 20037480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Interstitial irradiation therapy using radionuclides is a slow and continual process in which the effect is exerted gradually, thus improvement of the hypoxic status of the tumor will also take a long time. It has been known that carbogen delivery of 5-15 min increases tumor oxygenation. However, the long-term effect of carbogen breathing on hypoxic cells has not yet been determined, and little is know about the effect of carbogen breathing for sensitization to interstitial irradiation therapy. MATERIAL/METHODS 99mTc-HL91(99mTc 4,9-diaza-3,3,10,10-tetramethyldodecan-2,1-dione dioxime) hypoxic imaging was performed in 10 mice bearing sarcoma 180 (S180) before and after 2 h carbogen breathing. Radioactivity ratios of tumor to contralateral limbs (T/L) of the 2 images were calculated and compared. Mice bearing S180 were subjected to long-term carbogen breathing (2 h/day for 24 days), and were treated with or without 32P-colloid. Tumor growth rate was observed in the S180-bearing mice. RESULTS T/L of 99mTc-HL91 uptake before and after carbogen breathing was 1.872+/-0.391 and 1.354+/-0.189, respectively (t=4.476, P<0.01). In mice in the 32P-treated air breathing group and 32P-treated carbogen breathing group, tumor growth rate did not differ on day 12 after 32P-colloid treatment, and on day 24 the tumor volume was 2.728+/-0.469 and 2.237+/-0.603 cm3 (t=2.128, P<0.05), respectively, with tumor mass being 2.437+/-0.447 and 1.965+/-0.538 g (t=2.134, P<0.05), respectively. CONCLUSIONS Long-term carbogen breathing can increase tumor oxygenation and continual carbogen breathing is necessary for enhancing the therapeutic effect of 32P-colloid interstitial irradiation.
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Affiliation(s)
- Hong Wei Zhan
- Department of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of China.
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Malmström C, Konn M, Bogovski S, Lang T, Lönnström LG, Bylund G. Screening of hydrophobic DNA adducts in flounder (Platichthys flesus) from the Baltic Sea. Chemosphere 2009; 77:1514-9. [PMID: 19846194 DOI: 10.1016/j.chemosphere.2009.09.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 09/23/2009] [Indexed: 05/03/2023]
Abstract
Neoplasia and other histopathological lesions in flounder (Platichthys flesus) liver have been investigated in several European sea areas, including the Baltic Sea. Several studies have been able to link neoplasm epizootics in fish with the exposure to genotoxins such as polycyclic aromatic hydrocarbons (PAHs). The level of hydrophobic DNA adducts in tissue DNA reflects the exposure of the organism to PAHs. Using hydrophobic DNA adduct levels as biomarkers, possible PAH exposure was assessed in flounder from 10 different sites in the Baltic Sea, collected during the years 1995-1997. The results show that the overall levels of hepatic DNA adducts were low and, in general, the chromatograms appeared clean. The highest levels of DNA adducts were found at two sites in the southern Baltic Sea. There were no statistically significant differences in adduct levels between the sites. Our results indicate that flounder from studied off shore sites of the Baltic Sea had not been exposed to a greater extent to large polycyclic hydrophobic hydrocarbons in their environment.
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Affiliation(s)
- C Malmström
- Laboratory of Aquatic Pathobiology, Department of Biology, Abo Akademi University, BioCity, Artillerigatan 6, FIN-20520 Abo, Finland.
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Kovács P, Csaba G. The effect of histone deacetylase inhibitor trichostatin A (TSA) on the incorporation of 32P (Pi) and 3H-palmitic acid into the phospholipids of Tetrahymena. Cell Biochem Funct 2009; 26:39-42. [PMID: 17191269 DOI: 10.1002/cbf.1394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Histone deacetylases (HDACs) are able to control also the acetylation of tubulin. In the present experiments the effect of trichostatin A (TSA), a HDAC inhibitor was studied on the incorporation of 3H-palmitic acid and 32P to the phospholipids (PI, PIP, PS, PC, PA, PE) of Tetrahymena pyriformis, considering earlier observations on the microtubular system's influence on signalling in this unicellular eukaryote. Treatment with 1, 5, or 10 microM TSA was studied. The incorporation of hydrophobic tail component, palmitic acid was inhibited in a concentration dependent manner into all the phospholipids, except for PA, where the incorporation was increased. 32P incorporation was also inhibited. The possible relation between the microtubular system and signalling is discussed.
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Affiliation(s)
- Péter Kovács
- Department of Genetics, Cell and Immunobiology, Semmelweis University, Budapest, Hungary.
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