39 results on '"Dall'Angelo S."'
Search Results
2. Synthesis and hyperpolarisation of eNOS substrates for quantification of NO production by H-1 NMR spectroscopy
- Author
-
Diaz-Rullo, FF (Diaz-Rullo, Fernando Fernandez)[ 1,2 ], Zamberlan, F (Zamberlan, Francesco)[ 1,2 ], Mewis, RE (Mewis, Ryan E.)[ 3 ], Fekete, M (Fekete, Marianna)[ 3 ], Broche, L (Broche, Lionel)[ 1,2 ], Cheyne, LA (Cheyne, Lesley A.)[ 1,2 ], Dall'Angelo, S (Dall'Angelo, Sergio)[ 1,2 ], Duckett, SB (Duckett, Simon B.)[ 3 ], Dawson, D (Dawson, Dana)[ 1,2 ], and Zanda, M (Zanda, Matteo)[ 1,2,4 ]
- Subjects
SABRE ,Hyperpolarization ,Real-time imaging ,L-Arginine ,MRI - Abstract
Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of L-arginine into L-citrulline. NO is a free radical gas with a short half-life in vivo (approximate to 5 s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an L-Arg - to L-Cit-derivative by H-1 NMR spectroscopy is herein proposed. A small library of pyridyl containing L-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2- production = 19-46 uM) than native L-Arg (NO2- production = 25 mu M). Enzymatic conversion of L-Arg to L-Cit derivatives could be monitored by 1H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo. (C) 2017 The Authors. Published by Elsevier Ltd.
- Published
- 2017
3. Synthesis and Radiosynthesis of Prospective 2-Nitroimidazole Hypoxia PET Tracers via Thiazolidine Ligation with 5-Fluorodeoxyribose (FDR)
- Author
-
Musolino, M., additional, Dall’Angelo, S., additional, and Zanda, M., additional
- Published
- 2017
- Full Text
- View/download PDF
4. Probing the binding affinity and proteolytic stability of trifluoromethyl peptide mimics as protease inhibitors, chapter 3
- Author
-
Zanda M., Volonterio A., Sani M., and Dall'Angelo S.
- Published
- 2012
5. Synthesis of new 4-HPR analogues and use of PET imaging to support the development of drug candidates
- Author
-
Patruno I., Thomson D., Mody N., Windhorst A. D., Poot A. J., Vugts D. J., Dall'Angelo S., Zanda M.
- Subjects
carbohydrates (lipids) ,bacteria ,macromolecular substances ,3. Good health - Abstract
Fenretinide (4-HPR) is a synthetic retinoid which has been investigated for decades as an anticancer agent and more recently as a potential drug to treat metabolic syndrome.Here we synthesised a library of 4-HPR analogues - using a SAR approach - with the final goal to improve both anti-cancer activity and anti- obesity/diabetes properties of 4-HPR. Among the designed 4-HPR analogues, we selected the click-type analogue 3b, which is amenable to radiofluorination, to develop a PET tracer to further investigate the pharmacological profile of 4-HPR and analogues in vivo. 
6. Protein tyrosine phosphatase 1B in metabolic diseases and drug development.
- Author
-
Delibegović M, Dall'Angelo S, and Dekeryte R
- Subjects
- Humans, Animals, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 metabolism, Enzyme Inhibitors therapeutic use, Enzyme Inhibitors pharmacology, Signal Transduction drug effects, Obesity drug therapy, Obesity metabolism, Protein Tyrosine Phosphatase, Non-Receptor Type 1 antagonists & inhibitors, Protein Tyrosine Phosphatase, Non-Receptor Type 1 metabolism, Drug Development, Metabolic Diseases drug therapy, Metabolic Diseases metabolism
- Abstract
Protein tyrosine phosphatase 1B (PTP1B), a non-transmembrane phosphatase, has a major role in a variety of signalling pathways, including direct negative regulation of classic insulin and leptin signalling pathways, and is implicated in the pathogenesis of several cardiometabolic diseases and cancers. As such, PTP1B has been a therapeutic target for over two decades, with PTP1B inhibitors identified either from natural sources or developed throughout the years. Some of these inhibitors have reached phase I and/or II clinical trials in humans for the treatment of type 2 diabetes mellitus, obesity and/or metastatic breast cancer. In this Review, we summarize the cellular processes and regulation of PTP1B, discuss evidence from in vivo preclinical and human studies of the association between PTP1B and different disorders, and discuss outcomes of clinical trials. We outline challenges associated with the targeting of this phosphatase (which was, until the past few years, viewed as difficult to target), the current state of the field of PTP1B inhibitors (and dual phosphatase inhibitors) and future directions for manipulating the activity of this key metabolic enzyme., (© 2024. Springer Nature Limited.)
- Published
- 2024
- Full Text
- View/download PDF
7. The atypical 'hippocampal' glutamate receptor coupled to phospholipase D that controls stretch-sensitivity in primary mechanosensory nerve endings is homomeric purely metabotropic GluK2.
- Author
-
Thompson KJ, Watson S, Zanato C, Dall'Angelo S, De Nooij JC, Pace-Bonello B, Shenton FC, Sanger HE, Heinz BA, Broad LM, Grosjean N, McQuillian JR, Dubini M, Pyner S, Greig I, Zanda M, Bleakman D, Banks RW, and Bewick GS
- Subjects
- Animals, Mice, Hippocampus metabolism, Nerve Endings metabolism, Receptors, Glutamate metabolism, Phospholipase D metabolism, Receptors, Metabotropic Glutamate metabolism
- Abstract
A metabotropic glutamate receptor coupled to phospholipase D (PLD-mGluR) was discovered in the hippocampus over three decades ago. Its pharmacology and direct linkage to PLD activation are well established and indicate it is a highly atypical glutamate receptor. A receptor with the same pharmacology is present in spindle primary sensory terminals where its blockade can totally abolish, and its activation can double, the normal stretch-evoked firing. We report here the first identification of this PLD-mGluR protein, by capitalizing on its expression in primary mechanosensory terminals, developing an enriched source, pharmacological profiling to identify an optimal ligand, and then functionalizing it as a molecular tool. Evidence from immunofluorescence, western and far-western blotting indicates PLD-mGluR is homomeric GluK2, since GluK2 is the only glutamate receptor protein/receptor subunit present in spindle mechanosensory terminals. Its expression was also found in the lanceolate palisade ending of hair follicle, also known to contain the PLD-mGluR. Finally, in a mouse model with ionotropic function ablated in the GluK2 subunit, spindle glutamatergic responses were still present, confirming it acts purely metabotropically. We conclude the PLD-mGluR is a homomeric GluK2 kainate receptor signalling purely metabotropically and it is common to other, perhaps all, primary mechanosensory endings., (© 2023 The Authors. Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.)
- Published
- 2024
- Full Text
- View/download PDF
8. Chemoenzymatic Late-Stage Modifications Enable Downstream Click-Mediated Fluorescent Tagging of Peptides.
- Author
-
Colombano A, Dalponte L, Dall'Angelo S, Clemente C, Idress M, Ghazal A, and Houssen WE
- Subjects
- Peptides, Peptides, Cyclic chemistry, Butadienes, Hemiterpenes, Substrate Specificity, Tryptophan chemistry, Dimethylallyltranstransferase metabolism
- Abstract
Aromatic prenyltransferases from cyanobactin biosynthetic pathways catalyse the chemoselective and regioselective intramolecular transfer of prenyl/geranyl groups from isoprene donors to an electron-rich position in these macrocyclic and linear peptides. These enzymes often demonstrate relaxed substrate specificity and are considered useful biocatalysts for structural diversification of peptides. Herein, we assess the isoprene donor specificity of the N1-tryptophan prenyltransferase AcyF from the anacyclamide A8P pathway using a library of 22 synthetic alkyl pyrophosphate analogues, of which many display reactive groups that are amenable to additional functionalization. We further used AcyF to introduce a reactive moiety into a tryptophan-containing cyclic peptide and subsequently used click chemistry to fluorescently label the enzymatically modified peptide. This chemoenzymatic strategy allows late-stage modification of peptides and is useful for many applications., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
- Published
- 2023
- Full Text
- View/download PDF
9. Biochemical characterization of a cyanobactin arginine- N -prenylase from the autumnalamide biosynthetic pathway.
- Author
-
Clemente C, Johnson N, Ouyang X, Popin RV, Dall'Angelo S, Wahlsten M, Jokela J, Colombano A, Nardone B, Fewer DP, and Houssen WE
- Subjects
- Arginine metabolism, Homoarginine metabolism, Guanidine, Peptides, Cyclic chemistry, Biosynthetic Pathways, Dimethylallyltranstransferase chemistry, Dimethylallyltranstransferase metabolism
- Abstract
Cyanobactins are linear and cyclic post-translationally modified peptides. Here we show that the prenyl-D-Arg-containing autumnalamide A is a member of the cyanobactin family. Biochemical assays demonstrate that the AutF prenyltransferase targets the guanidinium moiety in arginine and homoarginine and is a useful tool for biotechnological applications.
- Published
- 2022
- Full Text
- View/download PDF
10. Guanidinoneomycin-maleimide molecular transporter: synthesis, chemistry and cellular uptake.
- Author
-
Hadidi K, Bellucci MC, Dall'Angelo S, Leeson-Payne A, Rochford JJ, Esko JD, Tor Y, and Volonterio A
- Abstract
Guanidinoglycosides are a class of non-cytotoxic molecular transporters capable of delivering high molecular weight bioactive cargos into cells at low nanomolar concentrations. Efficient bioconjugation with guanidinoglycosides has been previously demonstrated by utilizing a guanidinoneomycin decorated with a reactive but also unstable N-hydroxysuccinimmide ester-containing linker. Herein we report the synthesis, chemistry, and application of a new, stable guanidinoneomycin derivative armed with a highly specific maleimide moiety which allows for thiol-maleimide click chemistry, a highly popular bioconjugation strategy, widening the field of application of these intriguing and useful delivery vehicles.
- Published
- 2021
- Full Text
- View/download PDF
11. Clinical value of 3'-deoxy-3'-[ 18 F]fluorothymidine-positron emission tomography for diagnosis, staging and assessing therapy response in lung cancer.
- Author
-
Alwadani B, Dall'Angelo S, and Fleming IN
- Abstract
Lung cancer has the highest mortality rate of any tumour type. The main driver of lung tumour growth and development is uncontrolled cellular proliferation. Poor patient outcomes are partly the result of the limited range of effective anti-cancer therapies available and partly due to the limited accuracy of biomarkers to report on cell proliferation rates in patients. Accordingly, accurate methods of diagnosing, staging and assessing response to therapy are crucial to improve patient outcomes. One effective way of assessing cell proliferation is to employ non-invasive evaluation using 3'-deoxy-3'-[
18 F]fluorothymidine ([18 F]FLT) positron emission tomography [18 F]FLT-PET. [18 F]FLT, unlike the most commonly used PET tracer [18 F]fluorodeoxyglucose ([18 F]FDG), can specifically report on cell proliferation and does not accumulate in inflammatory cells. Therefore, this radiotracer could exhibit higher specificity in diagnosis and staging, along with more accurate monitoring of therapy response at early stages in the treatment cycle. This review summarises and evaluates published studies on the clinical use of [18 F]FLT to diagnose, stage and assess response to therapy in lung cancer.- Published
- 2021
- Full Text
- View/download PDF
12. 4,4,16-Trifluoropalmitate: Design, Synthesis, Tritiation, Radiofluorination and Preclinical PET Imaging Studies on Myocardial Fatty Acid Oxidation.
- Author
-
Colombano A, Dall'Angelo S, Kingston L, Grönberg G, Correia C, Passannante R, Baz Z, Morcillo MÁ, Elmore CS, Llop J, and Zanda M
- Subjects
- Animals, Fatty Acids chemical synthesis, Halogenation, Myocardium metabolism, Oxidation-Reduction, Radiopharmaceuticals chemical synthesis, Radiopharmaceuticals metabolism, Rats, Rats, Sprague-Dawley, Drug Design, Fatty Acids chemistry, Fatty Acids metabolism, Myocardium chemistry, Positron Emission Tomography Computed Tomography, Radiopharmaceuticals chemistry
- Abstract
Fatty acid oxidation (FAO) produces most of the ATP used to sustain the cardiac contractile work, although glycolysis is a secondary source of ATP under normal physiological conditions. FAO impairment has been reported in the advanced stages of heart failure (HF) and is strongly linked to disease progression and severity. Thus, from a clinical perspective, FAO dysregulation provides prognostic value for HF progression, the assessment of which could be used to improve patient monitoring and the effectiveness of therapy. Positron emission tomography (PET) imaging represents a powerful tool for the assessment and quantification of metabolic pathways in vivo. Several FAO PET tracers have been reported in the literature, but none of them is in routine clinical use yet. Metabolically trapped tracers are particularly interesting because they undergo FAO to generate a radioactive metabolite that is subsequently trapped in the mitochondria, thus providing a quantitative means of measuring FAO in vivo. Herein, we describe the design, synthesis, tritium labelling and radiofluorination of 4,4,16-trifluoro-palmitate (1) as a novel potential metabolically trapped FAO tracer. Preliminary PET-CT studies on [
18 F]1 in rats showed rapid blood clearance, good metabolic stability - confirmed by using [3 H]1 in vitro - and resistance towards defluorination. However, cardiac uptake in rats was modest (0.24±0.04 % ID/g), and kinetic analysis showed reversible uptake, thus indicating that [18 F]1 is not irreversibly trapped., (© 2020 Wiley-VCH GmbH.)- Published
- 2020
- Full Text
- View/download PDF
13. Design, Synthesis, Conjugation, and Reactivity of Novel trans,trans -1,5-Cyclooctadiene-Derived Bioorthogonal Linkers.
- Author
-
Longo B, Zanato C, Piras M, Dall'Angelo S, Windhorst AD, Vugts DJ, Baldassarre M, and Zanda M
- Subjects
- Alkadienes chemical synthesis, Animals, Cattle, Click Chemistry, Cycloaddition Reaction, Cyclooctanes chemical synthesis, Cyclooctanes chemistry, Fluorescent Dyes chemical synthesis, Serum Albumin, Bovine chemistry, Staphylococcus aureus cytology, Staphylococcus aureus isolation & purification, Alkadienes chemistry, Fluorescent Dyes chemistry
- Abstract
The tetrazine/ trans -cyclooctene (TCO) inverse electron-demand Diels-Alder (IEDDA) reaction is the fastest bioorthogonal "click" ligation process reported to date. In this context, TCO reagents have found widespread applications; however, their availability and structural diversity is still somewhat limited due to challenges connected with their synthesis and structural modification. To address this issue, we developed a novel strategy for the conjugation of TCO derivatives to a biomolecule, which allows for the creation of greater structural diversity from a single precursor molecule, i.e., trans,trans -1,5-cyclooctadiene [( E , E )-COD] 1 , whose preparation requires standard laboratory equipment and readily available reagents. This two-step strategy relies on the use of new bifunctional TCO linkers ( 5a - 11a ) for IEDDA reactions, which can be synthesized via 1,3-dipolar cycloaddition of ( E , E )-COD 1 with different azido spacers ( 5 - 11 ) carrying an electrophilic function (NHS-ester, N -succinimidyl carbonate, p -nitrophenyl-carbonate, maleimide) in the ω-position. Following bioconjugation of these electrophilic linkers to the nucleophilic residue (cysteine or lysine) of a protein (step 1), the resulting TCO-decorated constructs can be subjected to a IEDDA reaction with tetrazines functionalized with fluorescent or near-infrared (NIR) tags (step 2). We successfully used this strategy to label bovine serum albumin with the TCO linker 8a and subsequently reacted it in a cell lysate with the fluorescein-isothiocyanate (FITC)-derived tetrazine 12 . The same strategy was then used to label the bacterial wall of Gram-positive Staphylococcus aureus , showing the potential of these linkers for live-cell imaging. Finally, we determined the impact of structural differences of the linkers upon the stability of the bioorthogonal constructs. The compounds for stability studies were prepared by conjugation of TCO linkers 6a , 8a , and 10a to mAbs, such as Rituximab and Obinutuzumab, and subsequent labeling with a reactive Cy3-functionalized tetrazine.
- Published
- 2020
- Full Text
- View/download PDF
14. Widespread tissue hypoxia dysregulates cell and metabolic pathways in SMA.
- Author
-
Hernandez-Gerez E, Dall'Angelo S, Collinson JM, Fleming IN, and Parson SH
- Subjects
- Animals, Cells, Cultured, Disease Models, Animal, Mice, Mice, Transgenic, Hypoxia complications, Hypoxia metabolism, Metabolic Networks and Pathways, Motor Neurons metabolism, Muscular Atrophy, Spinal etiology, Muscular Atrophy, Spinal metabolism
- Abstract
Objective: The purpose of the study was to determine the extent and role of systemic hypoxia in the pathogenesis of spinal muscular atrophy (SMA)., Methods: Hypoxia was assayed in vivo in early-symptomatic (postnatal day 5) SMA-model mice by pimonidazole and [
18 F]-Fluoroazomycin arabinoside injections, which accumulate in hypoxic cells, followed by immunohistochemistry and tracer biodistribution evaluation. Glucose uptake in hypoxic cells was assayed by [18 F]-Fluorodeoxyglucose labeling. In vitro knockdown of Survival Motor Neuron (SMN) was performed on motor neurons and lactate metabolism measured biochemically, whereas cell cycle progression and cell death were assayed by flow cytometry., Results: All assays found significant levels of hypoxia in multiple organ systems in early symptomatic SMA mouse pups, except aerated tissues such as skin and lungs. This was accompanied by significantly increased glucose uptake in many affected organs, consistent with a metabolic hypoxia response. SMN protein levels were shown to vary widely between motor neuron precursors in vitro, and those with lower levels were most susceptible to cell death. In addition, SMA-model motor neurons were particularly sensitive to hypoxia, with reduced ability to transport lactate out of the cell in hypoxic culture, and a failure in normal cell cycle progression., Interpretation: Not only is there widespread tissue hypoxia and multi-organ cellular hypoxic response in SMA model mice, but SMA-model motor neurons are especially susceptible to that hypoxia. The data support the hypothesis that vascular defects leading to hypoxia are a significant contributor to disease progression in SMA, and offer a route for combinatorial, non-SMN related therapy., (© 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)- Published
- 2020
- Full Text
- View/download PDF
15. Design, Synthesis, Radiosynthesis and Biological Evaluation of Fenretinide Analogues as Anticancer and Metabolic Syndrome-Preventive Agents.
- Author
-
Patruno I, Thompson D, Dall'Angelo S, Windhorst AD, Vugts DJ, Poot AJ, Mody N, and Zanda M
- Subjects
- Animals, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Cell Differentiation drug effects, Cell Proliferation drug effects, Cell Survival drug effects, Cells, Cultured, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Fenretinide chemical synthesis, Fenretinide chemistry, Fluorine Radioisotopes, Humans, Lipids antagonists & inhibitors, Mice, Molecular Structure, Positron-Emission Tomography, Retinoids analysis, Structure-Activity Relationship, Antineoplastic Agents pharmacology, Drug Design, Fenretinide pharmacology, Metabolic Syndrome prevention & control
- Abstract
Fenretinide (4-HPR) is a synthetic derivative of all-trans-retinoic acid (ATRA) characterised by improved therapeutic properties and toxicological profile relative to ATRA. 4-HPR has been mostly investigated as an anti-cancer agent, but recent studies showed its promising therapeutic potential for preventing metabolic syndrome. Several biological targets are involved in 4-HPR's activity, leading to the potential use of this molecule for treating different pathologies. However, although 4-HPR displays quite well-understood multitarget promiscuity with regards to pharmacology, interpreting its precise physiological role remains challenging. In addition, despite promising results in vitro, the clinical efficacy of 4-HPR as a chemotherapeutic agent has not been satisfactory so far. Herein, we describe the preparation of a library of 4-HPR analogues, followed by the biological evaluation of their anti-cancer and anti-obesity/diabetic properties. The click-type analogue 3 b showed good capacity to reduce the amount of lipid accumulation in 3T3-L1 adipocytes during differentiation. Furthermore, it showed an IC
50 of 0.53±0.8 μM in cell viability tests on breast cancer cell line MCF-7, together with a good selectivity (SI=121) over noncancerous HEK293 cells. Thus, 3 b was selected as a potential PET tracer to study retinoids in vivo, and the radiosynthesis of [18 F]3b was successfully developed. Unfortunately, the stability of [18 F]3b turned out to be insufficient to pursue imaging studies., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2020
- Full Text
- View/download PDF
16. A Weakened Immune Response to Synthetic Exo-Peptides Predicts a Potential Biosecurity Risk in the Retrieval of Exo-Microorganisms.
- Author
-
Schaefer K, Dambuza IM, Dall'Angelo S, Yuecel R, Jaspars M, Trembleau L, Zanda M, Brown GD, Netea MG, and Gow NAR
- Abstract
The discovery of liquid water at several locations in the solar system raises the possibility that microbial life may have evolved outside Earth and as such could be accidently introduced into the Earth's ecosystem. Unusual sugars or amino acids, like non-proteinogenic isovaline and α-aminoisobutyric acid that are vanishingly rare or absent from life forms on Earth, have been found in high abundance on non-terrestrial carbonaceous meteorites. It is therefore conceivable that exo-microorganisms might contain proteins that include these rare amino acids. We therefore asked whether the mammalian immune system would be able to recognize and induce appropriate immune responses to putative proteinaceous antigens that include these rare amino acids. To address this, we synthesised peptide antigens based on a backbone of ovalbumin and introduced isovaline and α-aminoisobutyric acid residues and demonstrated that these peptides can promote naïve OT-I cell activation and proliferation, but did so less efficiently than the canonical peptides. This is relevant to the biosecurity of missions that may retrieve samples from exoplanets and moons that have conditions that may be permissive for life, suggesting that accidental contamination and exposure to exo-microorganisms with such distinct proteomes might pose an immunological challenge.
- Published
- 2020
- Full Text
- View/download PDF
17. [ 18 F]ZCDD083: A PFKFB3-Targeted PET Tracer for Atherosclerotic Plaque Imaging.
- Author
-
De Dominicis C, Perrotta P, Dall'Angelo S, Wyffels L, Staelens S, De Meyer GRY, and Zanda M
- Abstract
PFKFB3, a glycolysis-related enzyme upregulated in inflammatory conditions and angiogenesis, is an emerging target for diagnosis and therapy of atherosclerosis. The fluorinated phenoxindazole [
18 F] ZCDD083 was synthesized, radiolabeled in 17 ± 5% radiochemical yield and >99% radiochemical purity, and formulated for preclinical PET/CT imaging in mice. In vivo stability analysis showed no significant metabolite formation. Biodistribution studies showed high blood pool activity and slow hepatobiliary clearance. Significant activity was detected in the lung 2 h postinjection (pi) (11.0 ± 1.5%ID/g), while at 6 h pi no pulmonary background was observed. Ex vivo autoradiography at 6 h pi showed significant high uptake of [18 F] ZCDD083 in the arch region and brachiocephalic artery of atherosclerotic mice, and no uptake in control mice, matching plaques distribution seen by lipid staining along with PFKFB3 expression seen by immunofluorescent staining. In vivo PET scans showed higher aortic region uptake of [18 F] ZCDD083 in atherosclerotic ApoE-/- Fbn1C1039G+/- than in control mice (0.78 ± 0.05 vs 0.44 ± 0.09%ID/g). [18 F] ZCDD083 was detected in aortic arch and brachiocephalic artery of ApoE-/- (with moderate atherosclerosis) and ApoE-/- Fbn1C1039G+/- (with severe, advanced atherosclerosis) mice, suggesting this tracer may be useful for the noninvasive detection of atherosclerotic plaques in vivo ., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)- Published
- 2020
- Full Text
- View/download PDF
18. The Trifluoromethyl Group as a Bioisosteric Replacement of the Aliphatic Nitro Group in CB 1 Receptor Positive Allosteric Modulators.
- Author
-
Tseng CC, Baillie G, Donvito G, Mustafa MA, Juola SE, Zanato C, Massarenti C, Dall'Angelo S, Harrison WTA, Lichtman AH, Ross RA, Zanda M, and Greig IR
- Subjects
- Allosteric Regulation drug effects, Animals, Behavior, Animal drug effects, Binding Sites, Cyclic AMP metabolism, Drug Design, Isomerism, Ligands, Male, Mice, Mice, Inbred C57BL, Models, Molecular, Neuralgia drug therapy, Neuralgia psychology, Nitro Compounds pharmacokinetics, Small Molecule Libraries, Structure-Activity Relationship, Nitro Compounds chemical synthesis, Nitro Compounds pharmacology, Receptor, Cannabinoid, CB1 drug effects
- Abstract
The first generation of CB
1 positive allosteric modulators (e.g., ZCZ011) featured a 3-nitroalkyl-2-phenyl-indole structure. Although a small number of drugs include the nitro group, it is generally not regarded as being "drug-like", and this is particularly true for aliphatic nitro groups. There are very few case studies where an appropriate bioisostere replaced a nitro group that had a direct role in binding. This may be indicative of the difficulty of replicating its binding interactions. Herein, we report the design and synthesis of ligands targeting the allosteric binding site on the CB1 cannabinoid receptor, in which a CF3 group successfully replaced the aliphatic NO2 . In general, the CF3 -bearing compounds were more potent than their NO2 equivalents and also showed improved in vitro metabolic stability. The CF3 analogue (1) with the best balance of properties was selected for further pharmacological evaluation. Pilot in vivo studies showed that (±)-1 has similar activity to (±)-ZCZ011, with both showing promising efficacy in a mouse model of neuropathic pain.- Published
- 2019
- Full Text
- View/download PDF
19. Enzymatic radiosynthesis of a 18 F-Glu-Ureido-Lys ligand for the prostate-specific membrane antigen (PSMA).
- Author
-
Lowe PT, Dall'Angelo S, Fleming IN, Piras M, Zanda M, and O'Hagan D
- Subjects
- Cell Line, Tumor, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Glutamate Carboxypeptidase II antagonists & inhibitors, Humans, Isotope Labeling, Ligands, Streptomyces enzymology, Antigens, Surface metabolism, Bacterial Proteins metabolism, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors metabolism, Fluorine Radioisotopes, Glutamate Carboxypeptidase II metabolism, Lysine chemistry, Oxidoreductases metabolism, Radiochemistry methods
- Abstract
Prostate cancer represents a major public health threat as it is one of the most common male cancers worldwide. The prostate-specific membrane antigen (PSMA) is highly over-expressed in prostatic cancer cells in a manner that correlates with both tumour stage and clinical outcome. As such, PSMA has been identified as an attractive target for both imaging and treatment of prostate cancer. In recent years the focus on urea-based peptidomimetic inhibitors of the PSMA (representing low molecular weight/high affinity binders) has intensified as they have found use in the clinical imaging of prostate tumours. Reported herein are the design, synthesis and evaluation of a new fluorinated PSMA targeting small-molecule, FDA-PEG-GUL, which possesses the Glu-NH-CO-NH-Lys pharmacophore conjugated to a 5'-fluorodeoxy-adenosine unit. Inhibition assays were performed with FDA-PEG-GUL which revealed that it inhibits the PSMA in the nanomolar range. Additionally, it has been purposely designed so that it can be produced using the fluorinase enzyme from its chlorinated precursor, allowing for the enzymatic synthesis of radiolabelled [18F]FDA-PEG-GUL via a nucleophilic reaction that takes place in experimentally advantageous conditions (in water at neutral pH and at ambient temperature). Specific binding of [18F]FDA-PEG-GUL to PSMA expressing cancer cells was demonstrated, validating it as a promising PSMA diagnostic tool. This work establishes a successful substrate scope expansion for the fluorinase and demonstrates its first application towards targeting the PSMA.
- Published
- 2019
- Full Text
- View/download PDF
20. Enzymatic Fluorination of Biotin and Tetrazine Conjugates for Pretargeting Approaches to Positron Emission Tomography Imaging.
- Author
-
Lowe PT, Dall'Angelo S, Devine A, Zanda M, and O'Hagan D
- Subjects
- Bacterial Proteins chemistry, Biotin chemical synthesis, Cycloaddition Reaction, Cyclooctanes chemical synthesis, Cyclooctanes chemistry, Deoxyadenosines chemical synthesis, Halogenation, Oxidoreductases chemistry, Polyethylene Glycols chemical synthesis, Radiopharmaceuticals chemical synthesis, Radiopharmaceuticals chemistry, Streptavidin chemistry, Biotin chemistry, Deoxyadenosines chemistry, Fluorine Radioisotopes chemistry, Immunoconjugates chemistry, Polyethylene Glycols chemistry, Positron-Emission Tomography methods
- Abstract
The use of radiolabelled antibodies and antibody-derived recombinant constructs has shown promise for both imaging and therapeutic use. In this context, the biotin-avidin/streptavidin pairing, along with the inverse-electron-demand Diels-Alder (iEDDA) reaction, have found application in pretargeting approaches for positron emission tomography (PET). This study reports the fluorinase-mediated transhalogenation [5'-chloro-5'-deoxyadenosine (ClDA) substrates to 5'-fluoro-5'-deoxyadenosine (FDA) products] of two antibody pretargeting tools, a FDA-PEG-tetrazine and a [
18 F]FDA-PEG-biotin, and each is assessed either for its compatibility towards iEDDA ligation to trans-cyclooctene or for its affinity to avidin. A protocol to avoid radiolytically promoted oxidation of biotin during the synthesis of [18 F]FDA-PEG-biotin was developed. The study adds to the repertoire of conjugates for use in fluorinase-catalysed radiosynthesis for PET and shows that the fluorinase will accept a wide range of ClDA substrates tethered at C-2 of the adenine ring with a PEGylated cargo. The method is exceptional because the nucleophilic reaction with [18 F]fluoride takes place in water at neutral pH and at ambient temperature., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2018
- Full Text
- View/download PDF
21. Preclinical Evaluation of [ 18 F]LCATD as a PET Tracer to Study Drug-Drug Interactions Caused by Inhibition of Hepatic Transporters.
- Author
-
Testa A, Dall'Angelo S, Mingarelli M, Augello A, Schweiger L, Welch A, Elmore CS, Dawson D, Sharma P, and Zanda M
- Subjects
- Animals, Arteries metabolism, Bile Ducts metabolism, Female, Fluorine Radioisotopes blood, Fluorine Radioisotopes pharmacokinetics, Fusidic Acid pharmacology, Kinetics, Organ Specificity, Rats, Sprague-Dawley, Rifamycins pharmacology, Tissue Distribution, Triazoles blood, Triazoles pharmacokinetics, Drug Interactions, Fluorine Radioisotopes chemistry, Liver metabolism, Membrane Transport Proteins metabolism, Positron-Emission Tomography, Triazoles chemistry
- Abstract
The bile acid analogue [
18 F]LCATD (LithoCholic Acid Triazole Derivative) is transported in vitro by hepatic uptake transporters such as OATP1B1 and NTCP and efflux transporter BSEP. In this in vivo "proof of principle" study, we tested if [18 F]LCATD may be used to evaluate drug-drug interactions (DDIs) caused by inhibition of liver transporters. Hepatic clearance of [18 F]LCATD in rats was significantly modified upon coadministration of rifamycin SV or sodium fusidate, which are known to inhibit clinically relevant uptake transporters (OATP1B1, NTCP) and canalicular hepatic transporters (BSEP) in humans. Treatment with rifamycin SV (total dose 62.5 mg·Kg-1 ) reduced the maximum radioactivity of [18 F]LCATD recorded in the liver from 14.2 ± 0.8% to 10.2 ± 0.9% and delayed t_max by 90 seconds relative to control rats. AUCliver 0-5 min , AUCbile 0-10 min and hepatic uptake clearance CLuptake,in vivo of rifamycin SV treated rats were significantly reduced, whereas AUCliver 0-30 min was higher than in control rats. Administration of sodium fusidate (30 mg·Kg-1 ) inhibited the liver uptake of [18 F]LCATD , although to a lesser extent, reducing the maximum radioactivity in the liver to 11.5 ± 0.3%. These preliminary results indicate that [18 F]LCATD may be a good candidate for future applications as an investigational tracer to evaluate altered hepatobiliary excretion as a result of drug-induced inhibition of hepatic transporters.- Published
- 2018
- Full Text
- View/download PDF
22. Binding of α v β 3 Integrin-Specific Radiotracers Is Modulated by Both Integrin Expression Level and Activation Status.
- Author
-
Andriu A, Crockett J, Dall'Angelo S, Piras M, Zanda M, and Fleming IN
- Subjects
- Cell Line, Tumor, Cell Membrane metabolism, Extracellular Signal-Regulated MAP Kinases antagonists & inhibitors, Extracellular Signal-Regulated MAP Kinases metabolism, Humans, Protein Binding, Vascular Endothelial Growth Factor Receptor-2 antagonists & inhibitors, Vascular Endothelial Growth Factor Receptor-2 metabolism, src-Family Kinases antagonists & inhibitors, src-Family Kinases metabolism, Integrin alphaVbeta3 metabolism, Radiopharmaceuticals metabolism
- Abstract
Purpose: Molecular imaging of α
v β3 integrin has exhibited real potential to guide the appropriate use of anti-angiogenic therapies. However, an incomplete understanding of the factors that influence binding of αv β3 integrin-specific radiotracers currently limits their use for assessing response to therapy in cancer patients. This study identifies two fundamental factors that modulate uptake of these radiotracers. Procedures Experiments were performed in prostate cancer (PC3) and glioblastoma (U87MG) cells, which differentially express αv β3 integrin. αv β3 integrin-specific radiotracers were used to investigate the effect of manipulating αv β3 integrin expression or activation in cellular binding assays. β3 integrin and αv β3 integrin expression were measured by western blotting and flow cytometry, respectively. The effect of select pharmacological inhibitors on αv β3 integrin activation and expression was also determined., Results: Radiotracer binding was proportional to αv β3 integrin expression when it was decreased (β3 knock-down cells) or increased, either using pharmacological inhibitors of cell signalling or by culturing cells for different times. Studies with both small molecule and arginine-glycine-aspartic acid (RGD)-based radiotracers revealed increased radiotracer binding after activation of αv β3 integrin with Mn2+ or talin head domain. Moreover, inhibition of fundamental signalling pathways (mitogen-activated protein kinase kinase (MEK), Src and VEGFR2) decreased radiotracer binding, reflecting reduced αv β3 integrin activity., Conclusion: Binding of small molecule ligands and radiolabelled RGD peptides is modulated by expression and activation status of αv β3 integrin. αv β3 integrin-specific radiotracers can provide otherwise inaccessible information of the effect of signalling pathways on αv β3 integrin. This has significant implications for assessing response to anti-angiogenic therapies in clinical studies.- Published
- 2018
- Full Text
- View/download PDF
23. A New Class of Fluorinated A 2A Adenosine Receptor Agonist with Application to Last-Step Enzymatic [ 18 F]Fluorination for PET Imaging.
- Author
-
Lowe PT, Dall'Angelo S, Mulder-Krieger T, IJzerman AP, Zanda M, and O'Hagan D
- Subjects
- Bacterial Proteins chemistry, Fluorine Radioisotopes, Humans, Molecular Conformation, Oxidoreductases chemistry, Purinergic P1 Receptor Agonists chemical synthesis, Purinergic P1 Receptor Agonists metabolism, Receptor, Adenosine A2A metabolism, Bacterial Proteins metabolism, Halogenation, Oxidoreductases metabolism, Positron-Emission Tomography, Purinergic P1 Receptor Agonists chemistry
- Abstract
The A
2A adenosine receptor belongs to a family of G-coupled protein receptors that have been subjected to extensive investigation over the last few decades. Due to their prominent role in the biological functions of the heart, lungs, CNS and brain, they have become a target for the treatment of illnesses ranging from cancer immunotherapy to Parkinson's disease. The imaging of such receptors by using positron emission tomography (PET) has also been of interest, potentially providing a valuable tool for analysing and diagnosing various myocardial and neurodegenerative disorders, as well as offering support to drug discovery trials. Reported herein are the design, synthesis and evaluation of two new 5'-fluorodeoxy-adenosine (FDA)-based receptor agonists (FDA-PP1 and FDA-PP2), each substituted at the C-2 position with a terminally functionalised ethynyl unit. The structures enable a synthesis of18 F-labelled analogues by direct, last-step radiosynthesis from chlorinated precursors using the fluorinase enzyme (5'-fluoro-5'-deoxyadenosine synthase), which catalyses a transhalogenation reaction. This delivers a new class of A2A adenosine receptor agonist that can be directly radiolabelled for exploration in PET studies., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
- Full Text
- View/download PDF
24. High-Affinity "Click" RGD Peptidomimetics as Radiolabeled Probes for Imaging α v β 3 Integrin.
- Author
-
Piras M, Testa A, Fleming IN, Dall'Angelo S, Andriu A, Menta S, Mori M, Brown GD, Forster D, Williams KJ, and Zanda M
- Subjects
- Cell Line, Tumor, Click Chemistry, Fluorine Radioisotopes, Humans, Integrin alphaVbeta3 metabolism, Iodine Radioisotopes, Models, Molecular, Molecular Imaging, Oligopeptides chemistry, Peptidomimetics chemistry, Platelet Glycoprotein GPIIb-IIIa Complex chemistry, Platelet Glycoprotein GPIIb-IIIa Complex metabolism, Positron Emission Tomography Computed Tomography, Structure-Activity Relationship, Tritium, Integrin alphaVbeta3 chemistry, Oligopeptides chemical synthesis, Peptidomimetics chemical synthesis
- Abstract
Nonpeptidic Arg-Gly-Asp (RGD)-mimic ligands were designed and synthesized by click chemistry between an arginine-azide mimic and an aspartic acid-alkyne mimic. Some of these molecules combine excellent in vitro properties (high α
v β3 affinity, selectivity, drug-like logD, high metabolic stability) with a variety of radiolabeling options (e.g., tritium and fluorine-18, plus compatibility with radio-iodination), not requiring the use of chelators or prosthetic groups. The binding mode of the resulting triazole RGD mimics to αv β3 or αIIb β3 receptors was investigated by molecular modeling simulations. Lead compound 12 was successfully radiofluorinated and used for in vivo positron emission tomography/computed tomography (PET/CT) studies in U87 tumor models, which showed only modest tumor uptake and retention, owing to rapid excretion. These results demonstrate that the novel click RGD mimics are excellent radiolabeled probes for in vitro and cell-based studies on αv β3 integrin, whereas further optimization of their pharmacokinetic and dynamic profiles is necessary for successful use in in vivo imaging., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
- Full Text
- View/download PDF
25. Synthesis and hyperpolarisation of eNOS substrates for quantification of NO production by 1 H NMR spectroscopy.
- Author
-
Fernandez Diaz-Rullo F, Zamberlan F, Mewis RE, Fekete M, Broche L, Cheyne LA, Dall'Angelo S, Duckett SB, Dawson D, and Zanda M
- Subjects
- Animals, Arginine analogs & derivatives, Arginine metabolism, Biocatalysis, Cattle, Magnetic Resonance Spectroscopy, Nitric Oxide analysis, Nitric Oxide Synthase Type III chemistry, Nitric Oxide Synthase Type III genetics, Recombinant Proteins biosynthesis, Recombinant Proteins chemistry, Recombinant Proteins isolation & purification, Substrate Specificity, Arginine chemical synthesis, Nitric Oxide metabolism, Nitric Oxide Synthase Type III metabolism
- Abstract
Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging. An indirect method - based on quantifying conversion of an l-Arg- to l-Cit-derivative by
1 H NMR spectroscopy - is herein proposed. A small library of pyridyl containing l-Arg derivatives was designed and synthesised. In vitro tests showed that compounds 4a-j and 11a-c were better or equivalent substrates for the eNOS enzyme (NO2 - production=19-46μM) than native l-Arg (NO2 - production=25μM). Enzymatic conversion of l-Arg to l-Cit derivatives could be monitored by1 H NMR. The maximum hyperpolarization achieved by SABRE reached 870-fold NMR signal enhancement, which opens up exciting future perspectives of using these molecules as hyperpolarized MRI tracers in vivo., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
26. Synthesis and Superpotent Anticancer Activity of Tubulysins Carrying Non-hydrolysable N-Substituents on Tubuvaline.
- Author
-
Sani M, Lazzari P, Folini M, Spiga M, Zuco V, De Cesare M, Manca I, Dall'Angelo S, Frigerio M, Usai I, Testa A, Zaffaroni N, and Zanda M
- Subjects
- Animals, Antineoplastic Agents therapeutic use, Antineoplastic Agents toxicity, Apoptosis drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Drug Screening Assays, Antitumor, HT29 Cells, Humans, Mice, Microscopy, Fluorescence, Neoplasms drug therapy, Neoplasms pathology, Paclitaxel toxicity, Structure-Activity Relationship, Transplantation, Heterologous, Tubulin chemistry, Tubulin Modulators therapeutic use, Tubulin Modulators toxicity, Valine chemistry, Vinblastine analogs & derivatives, Vinblastine therapeutic use, Vinblastine toxicity, Vinorelbine, Antineoplastic Agents chemical synthesis, Tubulin metabolism, Tubulin Modulators chemical synthesis, Valine analogs & derivatives
- Abstract
Synthetic tubulysins 24 a-m, containing non-hydrolysable N-substituents on tubuvaline (Tuv), were obtained in high purity and good overall yields using a multistep synthesis. A key step was the formation of differently N-substituted Ile-Tuv fragments 10 by using an aza-Michael reaction of azido-Ile derivatives 8 with the α,β-unsaturated oxo-thiazole 5. A structure-activity relationship study using a panel of human tumour cell lines showed strong anti-proliferative activity for all compounds 24 a-m, with IC
50 values in the sub-nanomolar range, which were distinctly lower than those of tubulysin A, vinorelbine and paclitaxel. Furthermore, 24 a-m were able to overcome cross-resistance to paclitaxel and vinorelbine in two tumour cell lines with acquired resistance to doxorubicin. Compounds 24 e and 24 g were selected as leads to evaluate their mechanism of action. In vitro assays showed that both 24 e and 24 g interfere with tubulin polymerization in a vinca alkaloid-like manner and prevent paclitaxel-induced assembly of tubulin polymers. Both compounds exerted antimitotic activity and induced apoptosis in cancer cells at very low concentrations. Compound 24 e also exhibited potent antitumor activity at well tolerated doses on in vivo models of diffuse malignant peritoneal mesothelioma, such as MESOII peritoneal mesothelioma xenografts, the growth of which was not significantly affected by vinorelbine. These results indicate that synthetic tubulysins 24 could be used as standalone chemotherapeutic agents in difficult-to-treat cancers., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
- Full Text
- View/download PDF
27. Synthesis, radio-synthesis and in vitro evaluation of terminally fluorinated derivatives of HU-210 and HU-211 as novel candidate PET tracers.
- Author
-
Zanato C, Pelagalli A, Marwick KF, Piras M, Dall'Angelo S, Spinaci A, Pertwee RG, Wyllie DJ, Hardingham GE, and Zanda M
- Abstract
We report the synthesis of terminally fluorinated HU-210 and HU-211 analogues (HU-210F and HU-211F, respectively) and their biological evaluation as ligands of cannabinoid receptors (CB
1 and CB2 ) and N-methyl d-aspartate receptor (NMDAR). [18 F]-labelled HU-210F was radiosynthesised from the bromo-substituted precursor. In vitro assays showed that both HU-210F and HU-211F retain the potent pharmacological profile of HU-210 and HU-211, suggesting that [18 F]-radiolabelled HU-210F and HU-211F could have potential as PET tracers for in vivo imaging.- Published
- 2017
- Full Text
- View/download PDF
28. Design, synthesis, in vitro characterization and preliminary imaging studies on fluorinated bile acid derivatives as PET tracers to study hepatic transporters.
- Author
-
Testa A, Dall'Angelo S, Mingarelli M, Augello A, Schweiger L, Welch A, Elmore CS, Sharma P, and Zanda M
- Subjects
- Animals, Bile Acids and Salts chemical synthesis, Biological Transport, Female, Halogenation, Molecular Structure, Radioactive Tracers, Rats, Sprague-Dawley, Bile Acids and Salts chemistry, Drug Design, Liver metabolism, Positron-Emission Tomography
- Abstract
With the aim of identifying a fluorinated bile acid derivative that could be used as [
18 F]-labeled Positron Emission Tomography (PET) tracer for imaging the in vivo functioning of liver transporter proteins, and particularly of OATP1B1, three fluorinated bile acid triazole derivatives of cholic, deoxycholic and lithocholic acid (CATD, DCATD and LCATD 4a-c, respectively) were synthesized and labeled with tritium. In vitro transport properties were studied with cell-based assays to identify the best substrate for OATP1B1. In addition, the lead compound, LCATD (4c), was tested as a substrate of other liver uptake transporters OATP1B3, NTCP and efflux transporter BSEP to evaluate its specificity of liver transport. The results suggest that 4c is a good substrate of OATP1B1 and NTCP, whereas it is a poor substrate of OATP1B3. The efflux transporter BSEP also appears to be involved in the excretion of 4c from hepatocytes. The automated radiosynthesis of [18 F]-4c was accomplished in a multi-GBq scale and a pilot imaging experiment in a wild type rat was performed after i.v. administration to assess the biodistribution and clearance of the tracer. PET imaging revealed that radioactivity was primarily located in the liver (tmax =75s) and cleared exclusively through the bile, thus allowing to image the hepatobiliary excretion of bile acids in the animal model. These findings suggest that [18 F]-LCATD 4c is a promising PET probe for the evaluation of hepatic transporters OATP1B1, NTCP and BSEP activity with potential for studying drug-drug interactions and drug-induced toxicity involving these transporters., (Copyright © 2016 Elsevier Ltd. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
29. Last-Step Enzymatic [(18) F]-Fluorination of Cysteine-Tethered RGD Peptides Using Modified Barbas Linkers.
- Author
-
Zhang Q, Dall'Angelo S, Fleming IN, Schweiger LF, Zanda M, and O'Hagan D
- Subjects
- Humans, Models, Molecular, Peptides, Cysteine chemistry, Fluorine Radioisotopes chemistry
- Abstract
We report a last-step fluorinase-catalyzed [(18) F]-fluorination of a cysteine-containing RGD peptide. The peptide was attached through sulfur to a modified and more hydrophilic variant of the recently disclosed Barbas linker which was itself linked to a chloroadenosine moiety via a PEGylated chain. The fluorinase was able to use this construct as a substrate for a transhalogenation reaction to generate [(18) F]-radiolabeled RGD peptides, which retained high affinity to cancer-cell relevant αv β3 integrins., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
- Full Text
- View/download PDF
30. NGR Tumor-Homing Peptides: Structural Requirements for Effective APN (CD13) Targeting.
- Author
-
Graziadio A, Zanda M, Frau S, Fleming IN, Musolino M, Dall'Angelo S, Baldassarre M, and Piras M
- Subjects
- Amino Acid Sequence, Animals, Cell Line, Tumor, Humans, Models, Molecular, Protein Conformation, Swine, CD13 Antigens metabolism, Oligopeptides chemistry, Oligopeptides metabolism
- Abstract
Cyclic CNGRC (cCNGRC) peptides are very important targeting ligands for Aminopeptidase N (APN or CD13), which is overexpressed on the surface of many cancer cells. In this work we have (1) developed an efficient solid-phase synthesis and (2) tested on purified porcine APN and APN-expressing human cells two different classes of cCNGRC peptides: the first carrying a biotin affinity tag or a fluorescent tag attached to the carboxyl Arg-Cys-COOH terminus and the second with the tags attached to the amino H2N-Cys-Asn terminus. Carboxyl-terminus functionalized cCNGRC peptides 3, 6, and 8 showed good affinity for porcine APN and very good capacity to target and be internalized into APN-expressing cells. In contrast, amino-terminus functionalized cCNGRC peptides 4, 5, and 7 displayed significantly decreased affinity and targeting capacity. These results, which are in agreement with the recently reported X-ray structure of a cCNGRC peptide bound to APN showing important stabilizing interactions between the unprotected cCNGRC amino terminus and the APN active site, indicate that the carboxyl and not the amino-terminus of cCNGRC peptides should be used as a "handle" for the attachment of toxic payloads for therapy or isotopically labeled functions for imaging and nuclear medicine.
- Published
- 2016
- Full Text
- View/download PDF
31. Arginine analogues incorporating carboxylate bioisosteric functions are micromolar inhibitors of human recombinant DDAH-1.
- Author
-
Tommasi S, Zanato C, Lewis BC, Nair PC, Dall'Angelo S, Zanda M, and Mangoni AA
- Subjects
- Amidohydrolases chemistry, Amidohydrolases metabolism, Catalytic Domain drug effects, Humans, Molecular Docking Simulation, Molecular Dynamics Simulation, Triazoles chemistry, Triazoles pharmacology, Amidohydrolases antagonists & inhibitors, Arginine analogs & derivatives, Arginine pharmacology, Drug Design, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology
- Abstract
Dimethylarginine dimethylaminohydrolase (DDAH) is a key enzyme involved in the metabolism of asymmetric dimethylarginine (ADMA) and N-monomethyl arginine (NMMA), which are endogenous inhibitors of the nitric oxide synthase (NOS) family of enzymes. Two isoforms of DDAH have been identified in humans, DDAH-1 and DDAH-2. DDAH-1 inhibition represents a promising strategy to limit the overproduction of NO in pathological states without affecting the homeostatic role of this important messenger molecule. Here we describe the design and synthesis of 12 novel DDAH-1 inhibitors and report their derived kinetic parameters, IC50 and Ki. Arginine analogue 10a, characterized by an acylsulfonamide isosteric replacement of the carboxylate, showed a 13-fold greater inhibitory potential relative to the known DDAH-1 inhibitor, L-257. Compound 10a was utilized to study the putative binding interactions of human DDAH-1 inhibition using molecular dynamics simulations. The latter suggests that several stabilizing interactions occur in the DDAH-1 active-site, providing structural insights for the enhanced inhibitory potential demonstrated by in vitro inhibition studies.
- Published
- 2015
- Full Text
- View/download PDF
32. Efficient bioconjugation of 5-fluoro-5-deoxy-ribose (FDR) to RGD peptides for positron emission tomography (PET) imaging of α(v)β(3) integrin receptor.
- Author
-
Dall'Angelo S, Zhang Q, Fleming IN, Piras M, Schweiger LF, O'Hagan D, and Zanda M
- Subjects
- Cell Line, Tumor, Fluorodeoxyglucose F18 metabolism, Humans, Integrin alphaVbeta3 metabolism, Oligopeptides metabolism, Fluorodeoxyglucose F18 chemistry, Integrin alphaVbeta3 analysis, Oligopeptides chemistry, Positron-Emission Tomography methods
- Abstract
The utility of 5-fluoro-5-deoxyribose (FDR) as an efficient bioconjugation agent for radiolabelling of the RGD peptides c(RGDfK) and c(RGDfC) is demonstrated. The bioconjugation is significantly superior to that achieved with 2-fluoro-2-deoxyglucose (FDG) and benefits from the location of the fluorine at C-5, and that ribose is a 5-membered ring sugar rather than a 6-membered ring. Both features favour ring opening to the aldehydic form of the sugar to promote smooth oxime ligation with aminooxy ether functionalised peptides. [(18)F]FDR was prepared in this study by synthesis from fluoride-18 using an automated synthesis protocol adapting that used routinely for [(18)F]FDG. c(RGDfK) was functionalised with an aminooxyacetyl group (Aoa) via its lysine terminus, while c(RGDfC) was functionalised with an aminooxyhexylmaleimide (Ahm) through a cysteine-maleimide conjugation. Bioconjugation of [(18)F]FDR to c(RGDfC)-Ahm proved to be more efficient than c(RGDfK)-Aoa (92% versus 65%). The unlabelled ((19)F) bioconjugates c(RGDfK)-Aoa-FDR and c(RGDfC)-Ahm-FDR were prepared and their in vitro affinity to purified integrin αvβ3 was determined. c(RGDfK)-Aoa-FDR showed the greater affinity. Purified "hot" bioconjugates c(RGDfK)-Aoa-[(18)F]FDR and c(RGDfC)-Ahm-[(18)F]FDR were assayed by incubation with MCF7, LNCaP and PC3 cell lines. In both cases the conjugated RGD peptides showed selectivity for PC3 cells, which express αvβ3 integrin, with the c(RGDfK)-Aoa-[(18)F]FDR demonstrating better binding, consistent with its higher in vitro affinity. The study demonstrates that [(18)F]FDR is an efficient bioconjugation ligand for RGD bioactive peptides.
- Published
- 2013
- Full Text
- View/download PDF
33. Molecular insights into bacteroid development during Rhizobium-legume symbiosis.
- Author
-
Haag AF, Arnold MF, Myka KK, Kerscher B, Dall'Angelo S, Zanda M, Mergaert P, and Ferguson GP
- Subjects
- Ammonia metabolism, Carbon metabolism, Fabaceae metabolism, Nitrogen Fixation, Rhizobium growth & development, Rhizobium metabolism, Root Nodules, Plant metabolism, Fabaceae microbiology, Fabaceae physiology, Rhizobium physiology, Root Nodules, Plant microbiology, Root Nodules, Plant physiology, Symbiosis
- Abstract
Rhizobial soil bacteria can form a symbiosis with legumes in which the bacteria fix atmospheric nitrogen into ammonia that can be utilized by the host. The plant, in turn, supplies the rhizobia with a carbon source. After infecting the host cell, the bacteria differentiate into a distinct bacteroid form, which is able to fix nitrogen. The bacterial BacA protein is essential for bacteroid differentiation in legumes producing nodule-specific cysteine-rich peptides (NCRs), which induce the terminal differentiation of the bacteria into bacteroids. NCRs are antimicrobial peptides similar to mammalian defensins, which are important for the eukaryotic response to invading pathogens. The BacA protein is essential for rhizobia to survive the NCR peptide challenge. Similarities in the lifestyle of intracellular pathogenic bacteria suggest that host factors might also be important for inducing chronic infections associated with Brucella abortus and Mycobacterium tuberculosis. Moreover, rhizobial lipopolysaccharide is modified with an unusual fatty acid, which plays an important role in protecting the bacteria from environmental stresses. Mutants defective in the biosynthesis of this fatty acid display bacteroid development defects within the nodule. In this review, we will focus on these key components, which affect rhizobial bacteroid development and survival., (© 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
34. Tumour imaging by Positron Emission Tomography using fluorinase generated 5-[¹⁸F]fluoro-5-deoxyribose as a novel tracer.
- Author
-
Dall'Angelo S, Bandaranayaka N, Windhorst AD, Vugts DJ, van der Born D, Onega M, Schweiger LF, Zanda M, and O'Hagan D
- Subjects
- Animals, Bacterial Proteins chemistry, Biotransformation, Carcinoma, Squamous Cell pathology, Cell Line, Tumor, Enzyme Stability, Humans, Mice, N-Glycosyl Hydrolases chemistry, N-Glycosyl Hydrolases metabolism, Oxidoreductases chemistry, Radioactive Tracers, Radiochemistry, Ribose chemistry, Ribose metabolism, Bacterial Proteins metabolism, Carcinoma, Squamous Cell diagnostic imaging, Oxidoreductases metabolism, Positron-Emission Tomography methods, Ribose analogs & derivatives
- Abstract
Introduction: 5-[(18)F]Fluoro-5-deoxyribose ([(18)F]FDR) 3 was prepared as a novel monosaccharide radiotracer in a two-step synthesis using the fluorinase, a C-F bond forming enzyme, and a nucleoside hydrolase. The resulting [(18)F]FDR 3 was then explored as a radiotracer for imaging tumours (A431 human epithelial carcinoma) by positron emission tomography in a mice model., Methods: 5-[(18)F]Fluoro-5-deoxyribose ([(18)F]FDR) 3, was prepared by incubating S-adenosyl-L-methionine (SAM) and [(18)F]fluoride with the fluorinase enzyme, and then incubating the product of this reaction, [(18)F]-5'-fluoro-5'-deoxadenosine ([(18)F]FDA) 2, with an adenosine hydrolase to generate [(18)F]FDR 3. The enzymes were freeze-dried and were used on demand by dissolution in buffer solution. The resulting [(18)F]FDR 3 was then administered to four mice that had tumours induced from the A431 human epithelial carcinoma cell line., Results: The tumour (A431 human epithelial carcinoma) bearing mice were successfully imaged with [(18)F]FDR 3. The radiotracer displayed good tumour imaging resolution. A direct comparison of the uptake and efflux of [(18)F]FDR 3 with 2-[(18)F]fluoro-2-deoxyglucose ([(18)F]FDG) was made, revealing comparative tumour uptake and imaging potential over the first 10-20min. The study revealed however that [(18)F]FDR 3 does not accumulate in the tumour as efficiently as [(18)F]FDG over longer time periods., Conclusions: [(18)F]FDR 3 can be rapidly synthesised in a two enzyme protocol and used to image tumours in small animal models., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
35. 18F-barbiturates are PET tracers with diagnostic potential in Alzheimer's disease.
- Author
-
Calamai E, Dall'Angelo S, Koss D, Domarkas J, McCarthy TJ, Mingarelli M, Riedel G, Schweiger LF, Welch A, Platt B, and Zanda M
- Subjects
- Alzheimer Disease diagnosis, Alzheimer Disease genetics, Amyloid beta-Peptides genetics, Animals, Brain metabolism, Humans, Mice, Mice, Inbred C57BL, Mice, Transgenic, Plaque, Amyloid genetics, Positron-Emission Tomography methods, Up-Regulation, tau Proteins analysis, Alzheimer Disease diagnostic imaging, Amyloid beta-Peptides analysis, Barbiturates chemistry, Brain diagnostic imaging, Fluorine Radioisotopes chemistry, Plaque, Amyloid diagnostic imaging
- Abstract
Three fluoro-barbiturates were synthesised, showing in vivo sedative efficacy. One of them, [(18)F], was synthesised in radiofluorinated form. PET/CT Imaging with [(18)F] identified β-amyloid over-expressing transgenic mice (βA mice) compared to wild type and tau lines. The fluorescent barbiturate 9 was able to label βA plaques in brain sections of βA mice, and co-localise with a fluorescent Zn(II) indicator.
- Published
- 2013
- Full Text
- View/download PDF
36. [18F]-5-Fluoro-5-deoxyribose, an efficient peptide bioconjugation ligand for positron emission tomography (PET) imaging.
- Author
-
Li XG, Dall'Angelo S, Schweiger LF, Zanda M, and O'Hagan D
- Subjects
- Carcinoma, Hepatocellular diagnostic imaging, Carcinoma, Hepatocellular metabolism, Fluorine Radioisotopes chemistry, Humans, Hydrogen-Ion Concentration, Ligands, Liver Neoplasms diagnostic imaging, Liver Neoplasms metabolism, Oximes chemistry, Positron-Emission Tomography, Receptor, PAR-2 agonists, Receptor, PAR-2 metabolism, Fluorodeoxyglucose F18 chemistry, Peptides chemistry
- Abstract
[(18)F]-5-Fluoro-5-deoxyribose ([(18)F]-FDR) conjugates much more rapidly than [(18)F]-FDG under mild reaction conditions to peptides and offers new prospects for mild and rapid bioconjugation for fluorine-18 labelling in PET imaging., (This journal is © The Royal Society of Chemistry 2012)
- Published
- 2012
- Full Text
- View/download PDF
37. Role of cysteine residues and disulfide bonds in the activity of a legume root nodule-specific, cysteine-rich peptide.
- Author
-
Haag AF, Kerscher B, Dall'Angelo S, Sani M, Longhi R, Baloban M, Wilson HM, Mergaert P, Zanda M, and Ferguson GP
- Subjects
- Amino Acid Sequence, Antimicrobial Cationic Peptides metabolism, Bacterial Proteins metabolism, Membrane Transport Proteins metabolism, Molecular Sequence Data, Organ Specificity, Oxidation-Reduction, Sinorhizobium meliloti drug effects, Sinorhizobium meliloti metabolism, Antimicrobial Cationic Peptides chemistry, Antimicrobial Cationic Peptides pharmacology, Cysteine, Disulfides chemistry, Medicago truncatula chemistry, Root Nodules, Plant chemistry
- Abstract
The root nodules of certain legumes including Medicago truncatula produce >300 different nodule-specific cysteine-rich (NCR) peptides. Medicago NCR antimicrobial peptides (AMPs) mediate the differentiation of the bacterium, Sinorhizobium meliloti into a nitrogen-fixing bacteroid within the legume root nodules. In vitro, NCR AMPs such as NCR247 induced bacteroid features and exhibited antimicrobial activity against S. meliloti. The bacterial BacA protein is critical to prevent S. meliloti from being hypersensitive toward NCR AMPs. NCR AMPs are cationic and have conserved cysteine residues, which form disulfide (S-S) bridges. However, the natural configuration of NCR AMP S-S bridges and the role of these in the activity of the peptide are unknown. In this study, we found that either cysteine replacements or S-S bond modifications influenced the activity of NCR247 against S. meliloti. Specifically, either substitution of cysteines for serines, changing the S-S bridges from cysteines 1-2, 3-4 to 1-3, 2-4 or oxidation of NCR247 lowered its activity against S. meliloti. We also determined that BacA specifically protected S. meliloti against oxidized NCR247. Due to the large number of different NCRs synthesized by legume root nodules and the importance of bacterial BacA proteins for prolonged host infections, these findings have important implications for analyzing the function of these novel peptides and the protective role of BacA in the bacterial response toward these peptides.
- Published
- 2012
- Full Text
- View/download PDF
38. Protection of Sinorhizobium against host cysteine-rich antimicrobial peptides is critical for symbiosis.
- Author
-
Haag AF, Baloban M, Sani M, Kerscher B, Pierre O, Farkas A, Longhi R, Boncompagni E, Hérouart D, Dall'angelo S, Kondorosi E, Zanda M, Mergaert P, and Ferguson GP
- Subjects
- Amino Acid Sequence, Antimicrobial Cationic Peptides chemistry, Bacterial Proteins metabolism, Medicago truncatula drug effects, Microbial Viability drug effects, Molecular Sequence Data, Mutation genetics, Protein Structure, Secondary, Sinorhizobium meliloti cytology, Antimicrobial Cationic Peptides pharmacology, Cysteine metabolism, Host-Pathogen Interactions drug effects, Medicago truncatula microbiology, Sinorhizobium meliloti drug effects, Sinorhizobium meliloti physiology, Symbiosis drug effects
- Abstract
Sinorhizobium meliloti differentiates into persisting, nitrogen-fixing bacteroids within root nodules of the legume Medicago truncatula. Nodule-specific cysteine-rich antimicrobial peptides (NCR AMPs) and the bacterial BacA protein are essential for bacteroid development. However, the bacterial factors central to the NCR AMP response and the in planta role of BacA are unknown. We investigated the hypothesis that BacA is critical for the bacterial response towards NCR AMPs. We found that BacA was not essential for NCR AMPs to induce features of S. meliloti bacteroids in vitro. Instead, BacA was critical to reduce the amount of NCR AMP-induced membrane permeabilization and bacterial killing in vitro. Within M. truncatula, both wild-type and BacA-deficient mutant bacteria were challenged with NCR AMPs, but this resulted in persistence of the wild-type bacteria and rapid cell death of the mutant bacteria. In contrast, BacA was dispensable for bacterial survival in an M. truncatula dnf1 mutant defective in NCR AMP transport to the bacterial compartment. Therefore, BacA is critical for the legume symbiosis by protecting S. meliloti against the bactericidal effects of NCR AMPs. Host AMPs are ubiquitous in nature and BacA proteins are essential for other chronic host infections by symbiotic and pathogenic bacteria. Hence, our findings suggest that BacA-mediated protection of bacteria against host AMPs is a critical stage in the establishment of different prolonged host infections., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2011
- Full Text
- View/download PDF
39. Synthesis, characterization, and evaluation of a novel 99mTc(CO)3 pyrazolyl conjugate of a peptide nucleic acid sequence.
- Author
-
Xavier C, Giannini C, Dall'Angelo S, Gano L, Maiorana S, Alberto R, and Santos I
- Subjects
- Base Sequence, Cell Line, Tumor, Chelating Agents chemistry, Chromatography, High Pressure Liquid, Diamines chemistry, Humans, Models, Chemical, Molecular Probes metabolism, Neuroblastoma metabolism, Neuroblastoma pathology, Organotechnetium Compounds chemistry, Peptide Nucleic Acids genetics, Temperature, Time Factors, Molecular Probe Techniques, Molecular Probes chemical synthesis, Organotechnetium Compounds chemical synthesis, Peptide Nucleic Acids chemistry, Pyrazoles chemistry, Technetium chemistry
- Abstract
The 16-mer peptide nucleic acid sequence H-A GAT CAT GCC CGG CAT-Lys-NH2 (1), which is complementary to the translation start region of the N-myc oncogene messenger RNA, was synthesized and conjugated to a pyrazolyl diamine bifunctional chelator (pz). The novel conjugate pz-A GAT CAT GCC CGG CAT-Lys-NH2 (2) was labeled with technetium tricarbonyl, yielding quantitatively the complex fac-[99mTc(CO)3(kappa3-pz-A GAT CAT GCC CGG CAT-Lys-NH2)]2+ (4). Complex 4 was obtained with high radiochemical purity and high specific activity, revealing high stability in human serum and in cell culture medium. The identity of 4 was confirmed by comparing its reversed-phase high performance liquid chromatography profile with that of the rhenium analog fac-[Re(CO)3(kappa3-pz-A GAT CAT GCC CGG CAT-Lys-NH2)]2+ (3), prepared by conjugation of fac-[Re(CO)3(3,5-Me2pz(CH2)2N((CH2)3COOH)(CH2)2NH2)]+ to 1, using solid-phase techniques. UV melting experiments of 1 and 3 with the complementary DNA sequence led to the formation of stable duplexes, indicating that the conjugation of 1 to the pyrazolyl chelator and to the metal fragment fac-[M(CO)3]+ did not affect the recognition of the complementary sequence as well as the duplex stability. For a first screening, SH-SY5Y human neuroblastoma cells, which express N-myc, were treated with 4. The results show that 4 internalizes (7% of the activity goes into the cells, after 4 h at 37 degrees C), presenting also a relatively high cellular retention (only 40% of internalized activity is released from the cells after 5 h).
- Published
- 2008
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.