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Changes to Intermediary Metabolites in Sporadic and LRRK2Parkinson’s Disease Demonstrated by Proton Magnetic Resonance Spectroscopy. PARKINSON'S DISEASE 2015; 2015:264896. [PMID: 26357583 PMCID: PMC4556333 DOI: 10.1155/2015/264896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/02/2015] [Accepted: 07/07/2015] [Indexed: 11/17/2022]
Abstract
Background. Parkinson's disease (PD) remains a clinical diagnosis and biomarkers are needed to detect the disease as early as possible. Genetically determined PD provides an opportunity for studying metabolic differences in connection with disease development. Objectives. To study the levels of intermediary metabolites in cerebrospinal fluid (CSF) from patients with PD, either of sporadic type or in carriers of the LRRK2 p.G2019S mutation. Methods. Results from patients with sporadic PD or LRRK2-PD were compared with asymptomatic LRRK2 mutation carriers and healthy control individuals. CSF was analysed by proton MR spectroscopy (1H-MRS) giving reliable results for 16 intermediary metabolites. Partial least squares discriminant analysis (PLS-DA) was applied to study group differences. Results. PLS-DA distinguished PD patients from healthy individuals based on the metabolites identified in CSF, with 2-hydroxybutyrate, glutamine, and dimethyl sulphone largely contributing to the separations. Conclusion. Speculatively, all three metabolites could alter concentration in response to metabolic changes connected with neurodegeneration; glutamine as a means of removing excess nitrogen from brain, dimethyl sulphone as an anti-inflammatory agent, and 2-hydroxybutyrate in connection with altered glutathione metabolism. Potentially, 1H-MRS is a promising tool for identifying novel biomarkers for PD.
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Chen J, Lee HJ, Wu X, Huo L, Kim SJ, Xu L, Wang Y, He J, Bollu LR, Gao G, Su F, Briggs J, Liu X, Melman T, Asara JM, Fidler IJ, Cantley LC, Locasale JW, Weihua Z. Gain of glucose-independent growth upon metastasis of breast cancer cells to the brain. Cancer Res 2014; 75:554-65. [PMID: 25511375 DOI: 10.1158/0008-5472.can-14-2268] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Breast cancer brain metastasis is resistant to therapy and a particularly poor prognostic feature in patient survival. Altered metabolism is a common feature of cancer cells, but little is known as to what metabolic changes benefit breast cancer brain metastases. We found that brain metastatic breast cancer cells evolved the ability to survive and proliferate independent of glucose due to enhanced gluconeogenesis and oxidations of glutamine and branched chain amino acids, which together sustain the nonoxidative pentose pathway for purine synthesis. Silencing expression of fructose-1,6-bisphosphatases (FBP) in brain metastatic cells reduced their viability and improved the survival of metastasis-bearing immunocompetent hosts. Clinically, we showed that brain metastases from human breast cancer patients expressed higher levels of FBP and glycogen than the corresponding primary tumors. Together, our findings identify a critical metabolic condition required to sustain brain metastasis and suggest that targeting gluconeogenesis may help eradicate this deadly feature in advanced breast cancer patients.
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Affiliation(s)
- Jinyu Chen
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Ho-Jeong Lee
- Department of Cancer Biology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Xuefeng Wu
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Lei Huo
- Department of Pathology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Sun-Jin Kim
- Department of Cancer Biology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Lei Xu
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Yan Wang
- Department of Pathology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Junqing He
- Department of Cancer Biology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Lakshmi R Bollu
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Guang Gao
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Fei Su
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - James Briggs
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas
| | - Xiaojing Liu
- Division of Nutritional Sciences, Cornell University, Ithaca, New York
| | - Tamar Melman
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School Boston, Massachusetts
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School Boston, Massachusetts. Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Isaiah J Fidler
- Department of Cancer Biology, MD Anderson Cancer Center, The University of Texas, Houston, Texas
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medical College, New York, New York
| | - Jason W Locasale
- Division of Nutritional Sciences, Cornell University, Ithaca, New York
| | - Zhang Weihua
- Department of Biochemistry and Biology, College of Natural Science and Mathematics, University of Houston, Houston, Texas.
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Sanchez-Covarrubias L, Slosky LM, Thompson BJ, Davis TP, Ronaldson PT. Transporters at CNS barrier sites: obstacles or opportunities for drug delivery? Curr Pharm Des 2014; 20:1422-49. [PMID: 23789948 DOI: 10.2174/13816128113199990463] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/18/2013] [Indexed: 01/11/2023]
Abstract
The blood-brain barrier (BBB) and blood-cerebrospinal fluid (BCSF) barriers are critical determinants of CNS homeostasis. Additionally, the BBB and BCSF barriers are formidable obstacles to effective CNS drug delivery. These brain barrier sites express putative influx and efflux transporters that precisely control permeation of circulating solutes including drugs. The study of transporters has enabled a shift away from "brute force" approaches to delivering drugs by physically circumventing brain barriers towards chemical approaches that can target specific compounds of the BBB and/or BCSF barrier. However, our understanding of transporters at the BBB and BCSF barriers has primarily focused on understanding efflux transporters that efficiently prevent drugs from attaining therapeutic concentrations in the CNS. Recently, through the characterization of multiple endogenously expressed uptake transporters, this paradigm has shifted to the study of brain transporter targets that can facilitate drug delivery (i.e., influx transporters). Additionally, signaling pathways and trafficking mechanisms have been identified for several endogenous BBB/BCSF transporters, thereby offering even more opportunities to understand how transporters can be exploited for optimization of CNS drug delivery. This review presents an overview of the BBB and BCSF barrier as well as the many families of transporters functionally expressed at these barrier sites. Furthermore, we present an overview of various strategies that have been designed and utilized to deliver therapeutic agents to the brain with a particular emphasis on those approaches that directly target endogenous BBB/BCSF barrier transporters.
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Affiliation(s)
| | | | | | | | - Patrick T Ronaldson
- Department of Medical Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ, 85724-5050.
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Kamei N, Takeda-Morishita M. Brain delivery of insulin boosted by intranasal coadministration with cell-penetrating peptides. J Control Release 2014; 197:105-10. [PMID: 25445695 DOI: 10.1016/j.jconrel.2014.11.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/02/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
Intranasal administration is considered as an alternative route to enable effective drug delivery to the central nervous system (CNS) by bypassing the blood-brain barrier. Several reports have proved that macromolecules can be transferred directly from the nasal cavity to the brain. However, strategies to enhance the delivery of macromolecules from the nasal cavity to CNS are needed because of their low delivery efficiencies via this route in general. We hypothesized that the delivery of biopharmaceuticals to the brain parenchyma can be facilitated by increasing the uptake of drugs by the nasal epithelium including supporting and neuronal cells to maximize the potentiality of the intranasal pathway. To test this hypothesis, the CNS-related model peptide insulin was intranasally coadministered with the cell-penetrating peptide (CPP) penetratin to mice. As a result, insulin coadministered with l- or d-penetratin reached the distal regions of the brain from the nasal cavity, including the cerebral cortex, cerebellum, and brain stem. In particular, d-penetratin could intranasally deliver insulin to the brain with a reduced risk of systemic insulin exposure. Thus, the results obtained in this study suggested that CPPs are potential tools for the brain delivery of peptide- and protein-based pharmaceuticals via intranasal administration.
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Affiliation(s)
- Noriyasu Kamei
- Laboratory of Drug Delivery Systems, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, Hyogo 650-8586, Japan
| | - Mariko Takeda-Morishita
- Laboratory of Drug Delivery Systems, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, Hyogo 650-8586, Japan.
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156
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Ono A, Sugano K. Application of the BCS biowaiver approach to assessing bioequivalence of orally disintegrating tablets with immediate release formulations. Eur J Pharm Sci 2014; 64:37-43. [DOI: 10.1016/j.ejps.2014.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 07/15/2014] [Accepted: 08/12/2014] [Indexed: 12/01/2022]
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157
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Kadiyala KG, Datta A, Tanwar J, Adhikari A, Kumar BSH, Chuttani K, Thirumal M, Mishra AK. Metal Based Imaging Probes of DO3A-Act-Met for LAT1 Mediated Methionine Specific Tumors : Synthesis and Preclinical Evaluation. Pharm Res 2014; 32:955-67. [DOI: 10.1007/s11095-014-1509-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/29/2014] [Indexed: 11/30/2022]
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159
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Lapa C, Linsenmann T, Monoranu CM, Samnick S, Buck AK, Bluemel C, Czernin J, Kessler AF, Homola GA, Ernestus RI, Löhr M, Herrmann K. Comparison of the amino acid tracers 18F-FET and 18F-DOPA in high-grade glioma patients. J Nucl Med 2014; 55:1611-6. [PMID: 25125481 DOI: 10.2967/jnumed.114.140608] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED High-grade gliomas (HGGs) are the most common malignant primary tumors of the central nervous system. PET probes of amino acid transport such as O-(2-(18)F-fluoroethyl)-l-tyrosine ((18)F-FET), 3,4-dihydroxy-6-(18)F-fluoro-l-phenylalanine ((18)F-DOPA), and (11)C-methionine ((11)C-MET) detect primary and recurrent tumors with a high accuracy. (18)F-FET is predominantly used in Europe, whereas amino acid transport imaging is infrequently done in the United States. The aim of this study was to determine whether (18)F-FET and (18)F-DOPA PET/CT provide comparable information in HGG. METHODS Thirty (18)F-FET and (18)F-DOPA PET/CT scans were obtained before surgery or biopsy in 27 patients with high clinical suspicion for primary or recurrent HGG (5 primary, 22 recurrent tumors). (18)F-FET and (18)F-DOPA PET/CT images were compared visually and semiquantitatively (maximum standardized uptake value [SUV(max)], mean SUV [SUV(mean)]). Background (SUV(max) and SUV(mean)) and tumor-to-background ratios (TBRs) were calculated for both PET probes. The degree of (18)F-DOPA uptake in the basal ganglia (SUV(mean)) was also assessed. RESULTS Visual analysis revealed no difference in tumor uptake pattern between the 2 PET probes. The SUV(mean) and SUV(max) for (18)F-FET were higher than those of (18)F-DOPA (4.0 ± 2.0 and 4.9 ± 2.3 vs. 3.5 ± 1.6 and 4.3 ± 2.0, respectively; all P < 0.001). TBRs for SUV(mean) but not for SUV(max) were significantly higher for (18)F-FET than (18)F-DOPA (TBR SUV(mean): 3.8 ± 1.7 vs. 3.4 ± 1.2, P = 0.004; TBR SUV(max): 3.3 ± 1.6 and 3.0 ± 1.1, respectively; P = 0.086). (18)F-DOPA uptake by the basal ganglia was present (SUV(mean), 2.6 ± 0.7) but did not affect tumor visualization. CONCLUSION Whereas visual analysis revealed no significant differences in uptake pattern for (18)F-FET and (18)F-DOPA in patients with primary or recurrent HGG, both SUVs and TBRs for SUV(mean) were significantly higher for (18)F-FET. However, regarding tumor delineation, both tracers performed equally well and seem equally feasible for imaging of primary and recurrent HGG. These findings suggest that both PET probes can be used based on availability in multicenter trials.
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Affiliation(s)
- Constantin Lapa
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Thomas Linsenmann
- Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany
| | - Camelia Maria Monoranu
- Department of Neuropathology, Institute of Pathology, University of Würzburg, Würzburg, Germany
| | - Samuel Samnick
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Andreas K Buck
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Christina Bluemel
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Johannes Czernin
- Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California; and
| | - Almuth F Kessler
- Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany
| | - Gyoergy A Homola
- Department of Neuroradiology, University Hospital Würzburg, Würzburg, Germany
| | - Ralf-Ingo Ernestus
- Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany
| | - Mario Löhr
- Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany
| | - Ken Herrmann
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California; and
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Pochini L, Scalise M, Galluccio M, Indiveri C. Membrane transporters for the special amino acid glutamine: structure/function relationships and relevance to human health. Front Chem 2014; 2:61. [PMID: 25157349 PMCID: PMC4127817 DOI: 10.3389/fchem.2014.00061] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/16/2014] [Indexed: 12/26/2022] Open
Abstract
Glutamine together with glucose is essential for body's homeostasis. It is the most abundant amino acid and is involved in many biosynthetic, regulatory and energy production processes. Several membrane transporters which differ in transport modes, ensure glutamine homeostasis by coordinating its absorption, reabsorption and delivery to tissues. These transporters belong to different protein families, are redundant and ubiquitous. Their classification, originally based on functional properties, has recently been associated with the SLC nomenclature. Function of glutamine transporters is studied in cells over-expressing the transporters or, more recently in proteoliposomes harboring the proteins extracted from animal tissues or over-expressed in microorganisms. The role of the glutamine transporters is linked to their transport modes and coupling with Na+ and H+. Most transporters share specificity for other neutral or cationic amino acids. Na+-dependent co-transporters efficiently accumulate glutamine while antiporters regulate the pools of glutamine and other amino acids. The most acknowledged glutamine transporters belong to the SLC1, 6, 7, and 38 families. The members involved in the homeostasis are the co-transporters B0AT1 and the SNAT members 1, 2, 3, 5, and 7; the antiporters ASCT2, LAT1 and 2. The last two are associated to the ancillary CD98 protein. Some information on regulation of the glutamine transporters exist, which, however, need to be deepened. No information at all is available on structures, besides some homology models obtained using similar bacterial transporters as templates. Some models of rat and human glutamine transporters highlight very similar structures between the orthologs. Moreover the presence of glycosylation and/or phosphorylation sites located at the extracellular or intracellular faces has been predicted. ASCT2 and LAT1 are over-expressed in several cancers, thus representing potential targets for pharmacological intervention.
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Affiliation(s)
- Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
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161
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Automated synthesis of 18F-fluoropropoxytryptophan for amino acid transporter system imaging. BIOMED RESEARCH INTERNATIONAL 2014; 2014:492545. [PMID: 25136592 PMCID: PMC4127279 DOI: 10.1155/2014/492545] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/02/2014] [Accepted: 05/07/2014] [Indexed: 12/22/2022]
Abstract
Objective. This study was to develop a cGMP grade of [18F]fluoropropoxytryptophan (18F-FTP) to assess tryptophan transporters using an automated synthesizer. Methods. Tosylpropoxytryptophan (Ts-TP) was reacted with K18F/kryptofix complex. After column purification, solvent evaporation, and hydrolysis, the identity and purity of the product were validated by radio-TLC (1M-ammonium acetate : methanol = 4 : 1) and HPLC (C-18 column, methanol : water = 7 : 3) analyses. In vitro cellular uptake of 18F-FTP and 18F-FDG was performed in human prostate cancer cells. PET imaging studies were performed with 18F-FTP and 18F-FDG in prostate and small cell lung tumor-bearing mice (3.7 MBq/mouse, iv). Results. Radio-TLC and HPLC analyses of 18F-FTP showed that the Rf and Rt values were 0.9 and 9 min, respectively. Radiochemical purity was >99%. The radiochemical yield was 37.7% (EOS 90 min, decay corrected). Cellular uptake of 18F-FTP and 18F-FDG showed enhanced uptake as a function of incubation time. PET imaging studies showed that 18F-FTP had less tumor uptake than 18F-FDG in prostate cancer model. However, 18F-FTP had more uptake than 18F-FDG in small cell lung cancer model. Conclusion. 18F-FTP could be synthesized with high radiochemical yield. Assessment of upregulated transporters activity by 18F-FTP may provide potential applications in differential diagnosis and prediction of early treatment response.
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Medina-Enríquez MM, Alcántara-Farfán V, Aguilar-Faisal L, Trujillo-Ferrara JG, Rodríguez-Páez L, Vargas-Ramírez AL. N-ω-chloroacetyl-l-ornithine, a new competitive inhibitor of ornithine decarboxylase, induces selective growth inhibition and cytotoxicity on human cancer cells versus normal cells. J Enzyme Inhib Med Chem 2014; 30:345-53. [PMID: 24939101 DOI: 10.3109/14756366.2014.926342] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Many cancer cells have high expression of ornithine decarboxylase (ODC) and there is a concerted effort to seek new inhibitors of this enzyme. The aim of the study was to initially characterize the inhibition properties, then to evaluate the cytotoxicity/antiproliferative cell based activity of N-ω-chloroacetyl-l-ornithine (NCAO) on three human cancer cell lines. Results showed NCAO to be a reversible competitive ODC inhibitor (Ki = 59 µM) with cytotoxic and antiproliferative effects, which were concentration- and time-dependent. The EC50,72h of NCAO was 15.8, 17.5 and 10.1 µM for HeLa, MCF-7 and HepG2 cells, respectively. NCAO at 500 µM completely inhibited growth of all cancer cells at 48 h treatment, with almost no effect on normal cells. Putrescine reversed NCAO effects on MCF-7 and HeLa cells, indicating that this antiproliferative activity is due to ODC inhibition.
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Affiliation(s)
- Miriam Marlene Medina-Enríquez
- Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. Prol. Carpio y Plan de Ayala , México, D.F.
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Atrial natriuretic peptide and renal dopaminergic system: a positive friendly relationship? BIOMED RESEARCH INTERNATIONAL 2014; 2014:710781. [PMID: 25013796 PMCID: PMC4075025 DOI: 10.1155/2014/710781] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/12/2014] [Accepted: 05/12/2014] [Indexed: 01/11/2023]
Abstract
Sodium metabolism by the kidney is accomplished by an intricate interaction between signals from extrarenal and intrarenal sources and between antinatriuretic and natriuretic factors. Renal dopamine plays a central role in this interactive network. The natriuretic hormones, such as the atrial natriuretic peptide, mediate some of their effects by affecting the renal dopaminergic system. Renal dopaminergic tonus can be modulated at different steps of dopamine metabolism (synthesis, uptake, release, catabolism, and receptor sensitization) which can be regulated by the atrial natriuretic peptide. At tubular level, dopamine and atrial natriuretic peptide act together in a concerted manner to promote sodium excretion, especially through the overinhibition of Na+, K+-ATPase activity. In this way, different pathological scenarios where renal sodium excretion is dysregulated, as in nephrotic syndrome or hypertension, are associated with impaired action of renal dopamine and/or atrial natriuretic peptide, or as a result of impaired interaction between these two natriuretic systems. The aim of this review is to update and comment on the most recent evidences demonstrating how the renal dopaminergic system interacts with atrial natriuretic peptide to control renal physiology and blood pressure through different regulatory pathways.
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Nedergaard MK, Kristoffersen K, Michaelsen SR, Madsen J, Poulsen HS, Stockhausen MT, Lassen U, Kjaer A. The use of longitudinal 18F-FET MicroPET imaging to evaluate response to irinotecan in orthotopic human glioblastoma multiforme xenografts. PLoS One 2014; 9:e100009. [PMID: 24918622 PMCID: PMC4053391 DOI: 10.1371/journal.pone.0100009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/21/2014] [Indexed: 11/26/2022] Open
Abstract
Objectives Brain tumor imaging is challenging. Although 18F-FET PET is widely used in the clinic, the value of 18F-FET MicroPET to evaluate brain tumors in xenograft has not been assessed to date. The aim of this study therefore was to evaluate the performance of in vivo18F-FET MicroPET in detecting a treatment response in xenografts. In addition, the correlations between the 18F-FET tumor accumulation and the gene expression of Ki67 and the amino acid transporters LAT1 and LAT2 were investigated. Furthermore, Ki67, LAT1 and LAT2 gene expression in xenograft and archival patient tumors was compared. Methods Human GBM cells were injected orthotopically in nude mice and 18F-FET uptake was followed by weekly MicroPET/CT. When tumor take was observed, mice were treated with CPT-11 or saline weekly. After two weeks of treatment the brain tumors were isolated and quantitative polymerase chain reaction were performed on the xenograft tumors and in parallel on archival patient tumor specimens. Results The relative tumor-to-brain (T/B) ratio of SUVmax was significantly lower after one week (123±6%, n = 7 vs. 147±6%, n = 7; p = 0.018) and after two weeks (142±8%, n = 5 vs. 204±27%, n = 4; p = 0.047) in the CPT-11 group compared with the control group. Strong negative correlations between SUVmax T/B ratio and LAT1 (r = −0.62, p = 0.04) and LAT2 (r = −0.67, p = 0.02) were observed. In addition, a strong positive correlation between LAT1 and Ki67 was detected in xenografts. Furthermore, a 1.6 fold higher expression of LAT1 and a 23 fold higher expression of LAT2 were observed in patient specimens compared to xenografts. Conclusions 18F-FET MicroPET can be used to detect a treatment response to CPT-11 in GBM xenografts. The strong negative correlation between SUVmax T/B ratio and LAT1/LAT2 indicates an export transport function. We suggest that 18F-FET PET may be used for detection of early treatment response in patients.
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Affiliation(s)
- Mette K. Nedergaard
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Karina Kristoffersen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Signe R. Michaelsen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Jacob Madsen
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Hans S. Poulsen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | | | - Ulrik Lassen
- Phase 1 Unit, Department of Oncology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
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165
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Wang G, Dai L, Luo L, Xu W, Zhang C, Zhu Y, Chen Z, Hu W, Xu X, Pan W. Non-essential amino acids attenuate apoptosis of gastric cancer cells induced by glucose starvation. Oncol Rep 2014; 32:332-40. [PMID: 24858809 DOI: 10.3892/or.2014.3205] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/23/2014] [Indexed: 11/06/2022] Open
Abstract
Energy and nutrition are essential requirements for all living cells, including cancer cells. In the initiating stage of cancer in organs, cancer cells grow fast and have inadequate supplies of glucose, oxygen and other nutrients due to deficient angiogenesis. Anaerobic conditions cause cancer cells to rely on glycolysis, which produces pyruvate and ATP that can be used by cancer cells to survive. However, glucose starvation may result in apoptosis or necrosis of cancer cells. It has been reported that autophagy is a consequence of glucose starvation and that amino acids are products of autophagy. The present study investigated whether amino acids may represent an alternative energy source for cancer cells undergoing glucose starvation. With non-essential amino acids, growth inhibition and apoptosis of gastric cancer cells induced by glucose starvation were attenuated compared with that of cells undergoing glucose starvation without amino acids, as measured by cell viability, apoptosis rates, membrane potential of mitochondria, and apoptosis-related genes. Meanwhile, both mitochondrial DNA copy number and amino acid transporter genes were increased compared with those in control cells. Non-essential amino acids prevented gastric cancer cells from glucose starvation-induced apoptosis.
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Affiliation(s)
- Gang Wang
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Lei Dai
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Laisheng Luo
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Wen Xu
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Chenjing Zhang
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Yimiao Zhu
- Department of Gastroenterology, The Second Affiliated Hospital Binjiang Campus, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Zhongting Chen
- Department of Pharmacy, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Wen Hu
- Department of Gastroenterology, The Second Affiliated Hospital Binjiang Campus, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Xiang Xu
- Department of Pharmacy, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Wensheng Pan
- Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
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Giglia JL, White MJ, Hart AJ, Toro JJ, Freytes CO, Holt CC, Cai Y, Williams SM, Brandt SJ. A single nucleotide polymorphism in SLC7A5 is associated with gastrointestinal toxicity after high-dose melphalan and autologous stem cell transplantation for multiple myeloma. Biol Blood Marrow Transplant 2014; 20:1014-20. [PMID: 24704384 DOI: 10.1016/j.bbmt.2014.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 03/20/2014] [Indexed: 01/01/2023]
Abstract
Multiple myeloma is the most frequent indication for high-dose melphalan (HDM) chemotherapy with autologous stem cell transplantation (ASCT). Gastrointestinal symptoms represent the most significant nonhematological toxicity of HDM. However, specific, especially genetic, predictors of their incidence or clinical severity are lacking. The amino acid transporters LAT1 and LAT2 encoded by the SLC7A5 and SLC7A8 genes, respectively, are the principal mediators of melphalan uptake into cells. To determine whether genetic variability at these loci contributed to interindividual differences in the development of gastrointestinal complications of HDM, we analyzed single nucleotide polymorphisms (SNPs) in these genes in 135 patients with multiple myeloma treated with HDM and ASCT and correlated these with the need for total parenteral nutrition (TPN). Seven SNPs in SLC7A5 and 20 in SLC7A8 were genotyped. Multiple analyses indicated that 1 SNP in the first intron of SLC7A5, rs4240803, was significantly associated with TPN use (odds ratio = .45, 95% confidence interval, .25 to .79; P = .007). Further, every haplotype that correlated with TPN requirement included this SNP. These results suggest that variability in melphalan transport affects mucosal injury after HDM. This finding could help in individualizing the dose of this effective and widely used chemotherapeutic agent for multiple myeloma.
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Affiliation(s)
- Jennifer L Giglia
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Marquitta J White
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee; Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Andrew J Hart
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Juan J Toro
- University of Texas Health Science Center at San Antonio, San Antonio, Texas; Department of Veterans Affairs South Texas Veterans Health Care System, Audie L. Murphy VA Hospital, San Antonio, Texas
| | - César O Freytes
- University of Texas Health Science Center at San Antonio, San Antonio, Texas; Department of Veterans Affairs South Texas Veterans Health Care System, Audie L. Murphy VA Hospital, San Antonio, Texas
| | - Cherish C Holt
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee; Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ying Cai
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Scott M Williams
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee; Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Stephen J Brandt
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee; Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Veterans Affairs Tennessee Valley Healthcare System, Nashville VA Hospital, Nashville, Tennessee.
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167
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Patel M, Mandava NK, Pal D, Mitra AK. Amino acid prodrug of quinidine: An approach to circumvent P-glycoprotein mediated cellular efflux. Int J Pharm 2014; 464:196-204. [DOI: 10.1016/j.ijpharm.2014.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/13/2013] [Accepted: 01/06/2014] [Indexed: 01/07/2023]
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168
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Breast Cancer Cells Imaging By Targeting Methionine Transporters with Gadolinium-Based Nanoprobe. Mol Imaging Biol 2014; 16:519-28. [DOI: 10.1007/s11307-014-0718-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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169
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Galluccio M, Pingitore P, Scalise M, Indiveri C. Cloning, large scale over-expression in E. coli and purification of the components of the human LAT 1 (SLC7A5) amino acid transporter. Protein J 2014; 32:442-8. [PMID: 23912240 DOI: 10.1007/s10930-013-9503-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The high yield expression of the human LAT1 transporter has been obtained for the first time using E. coli. The hLAT1 cDNA was amplified from HEK293 cells and cloned in pH6EX3 vector. The construct pH6EX3-6His-hLAT1 was used to express the 6His-hLAT1 protein in the Rosetta(DE3)pLysS strain of E. coli. The highest level of expression was detected 8 h after induction by IPTG at 28 °C. The expressed protein was collected in the insoluble fraction of cell lysate. On SDS-PAGE the apparent molecular mass of the polypeptide was 40 kDa. After solubilization with sarkosyl and denaturation with urea the protein carrying a 6His N-terminal tag was purified by Ni(2+)-chelating affinity chromatography and identified by anti-His antibody. The yield of the over-expressed protein after purification was 3.5 mg/L (cell culture). The human CD98 cDNA amplified from Imagene plasmid was cloned in pGEX-4T1. The construct pGEX-4T1-hCD98 was used to express the GST-hCD98 protein in the Rosetta(DE3)pLysS strain of E. coli. The highest level of expression was detected in this case 4 h after induction by IPTG at 28 °C. The expressed protein was accumulated in the soluble fraction of cell lysate. The molecular mass was determined on the basis of marker proteins on SDS-PAGE; it was about 110 kDa. GST was cleaved from the protein construct by incubation with thrombin for 12 h and the hCD98 was separated by Sephadex G-200 chromatography (size exclusion). hCD98 showed a 62 kDa apparent molecular mass, as determined on the basis of molecular mass markers using SDS-PAGE. The yield of CD98 was 2 mg/L of cell culture.
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Affiliation(s)
- Michele Galluccio
- Unit of Biochemistry and Molecular Biotechnology, Department BEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via P. Bucci 4c, 87036, Arcavacata di Rende, Italy
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Zimmermann LT, dos Santos DB, Colle D, dos Santos AA, Hort MA, Garcia SC, Bressan LP, Bohrer D, Farina M. Methionine stimulates motor impairment and cerebellar mercury deposition in methylmercury-exposed mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:46-56. [PMID: 24555646 DOI: 10.1080/15287394.2014.865582] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Methylmercury (MeHg) is a highly toxic environmental contaminant that produces neurological and developmental impairments in animals and humans. Although its neurotoxic properties have been widely reported, the molecular mechanisms by which MeHg enters the cells and exerts toxicity are not yet completely understood. Taking into account that MeHg is found mostly bound to sulfhydryl-containing molecules such as cysteine in the environment and based on the fact that the MeHg-cysteine complex (MeHg-S-Cys) can be transported via the L-type neutral amino acid carrier transport (LAT) system, the potential beneficial effects of L-methionine (L-Met, a well known LAT substrate) against MeHg (administrated as MeHg-S-Cys)-induced neurotoxicity in mice were investigated. Mice were exposed to MeHg (daily subcutaneous injections of MeHg-S-Cys, 10 mg Hg/kg) and/or L-Met (daily intraperitoneal injections, 250 mg/kg) for 10 consecutive days. After treatments, the measured hallmarks of toxicity were mostly based on behavioral parameters related to motor performance, as well as biochemical parameters related to the cerebellar antioxidant glutathione (GSH) system. MeHg significantly decreased motor activity (open-field test) and impaired motor performance (rota-rod task) compared with controls, as well as producing disturbances in the cerebellar antioxidant GSH system. Interestingly, L-Met administration did not protect against MeHg-induced behavioral and cerebellar changes, but rather increased motor impairments in animals exposed to MeHg. In agreement with this observation, cerebellar levels of mercury (Hg) were higher in animals exposed to MeHg plus L-Met compared to those only exposed to MeHg. However, this event was not observed in kidney and liver. These results are the first to demonstrate that L-Met enhances cerebellar deposition of Hg in mice exposed to MeHg and that this higher deposition may be responsible for the greater motor impairment observed in mice simultaneously exposed to MeHg and L-Met.
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Affiliation(s)
- Luciana T Zimmermann
- a Departamento de Bioquímica, Centro de Ciências Biológicas , Universidade Federal de Santa Catarina , Florianópolis , Santa Catarina , Brazil
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Tachikawa M, Uchida Y, Ohtsuki S, Terasaki T. Recent Progress in Blood–Brain Barrier and Blood–CSF Barrier Transport Research: Pharmaceutical Relevance for Drug Delivery to the Brain. DRUG DELIVERY TO THE BRAIN 2014. [DOI: 10.1007/978-1-4614-9105-7_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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172
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Kratochwil C, Combs SE, Leotta K, Afshar-Oromieh A, Rieken S, Debus J, Haberkorn U, Giesel FL. Intra-individual comparison of ¹⁸F-FET and ¹⁸F-DOPA in PET imaging of recurrent brain tumors. Neuro Oncol 2013; 16:434-40. [PMID: 24305717 DOI: 10.1093/neuonc/not199] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Both (18)F-fluorodihydroxyphenylalanine ((18)F-DOPA) and (18)F-fluoroethyltyrosine ((18)F-FET) have already been used successfully for imaging of brain tumors. The aim of this study was to evaluate differences between these 2 promising tracers to determine the consequences for imaging protocols and the interpretation of findings. METHODS Forty minutes of dynamic PET imaging were performed on 2 consecutive days with both (18)F-DOPA and (18)F-FET in patients with recurrent low-grade astrocytoma (n = 8) or high-grade glioblastoma (n = 8). Time-activity-curves (TACs), standardized uptake values (SUVs) and compartment modeling of both tracers were analyzed, respectively. RESULTS The TAC of DOPA-PET peaked at 8 minutes p.i. with SUV 5.23 in high-grade gliomas and 10 minutes p.i. with SUV 4.92 in low-grade gliomas. FET-PET peaked at 9 minutes p.i. with SUV 3.17 in high-grade gliomas and 40 minutes p.i. with SUV 3.24 in low-grade gliomas. Neglecting the specific uptake of DOPA into the striatum, the tumor-to-brain and tumor-to-blood ratios were higher for DOPA-PET. Kinetic modeling demonstrated a high flow constant k1 (mL/ccm/min), representing cellular internalization through AS-transporters, for DOPA in both high-grade (k1 = 0.59) and low-grade (k1 = 0.55) tumors, while lower absolute values and a relevant dependency from tumor-grading (high-grade k1 = 0.43; low-grade k1 = 0.33) were observed with FET. CONCLUSIONS DOPA-PET demonstrates superior contrast ratios for lesions outside the striatum, but SUVs do not correlate with grading. FET-PET can provide additional information on tumor grading and benefits from lower striatal uptake but presents lower contrast ratios and requires prolonged imaging if histology is not available in advance due to a more variable time-to-peak.
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Affiliation(s)
- Clemens Kratochwil
- Department of Nuclear Medicine, University Hospital of Heidelberg, Heidelberg, Germany (C.K., K.L., A.A-O., U.H., F.L.G.); Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany (S.E.C., S.R., J.D.)
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173
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Karaman R. Prodrugs Design Based on Inter- and Intramolecular Chemical Processes. Chem Biol Drug Des 2013; 82:643-68. [DOI: 10.1111/cbdd.12224] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/13/2013] [Accepted: 08/16/2013] [Indexed: 01/29/2023]
Affiliation(s)
- Rafik Karaman
- Bioorganic Chemistry Department; Faculty of Pharmacy; Al-Quds University; P.O. Box 20002 Jerusalem Palestine
- Department of Science; University of Basilicata; Via dell'Ateneo Lucano 10 85100 Potenza Italy
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Walker MD, Dinelle K, Kornelsen R, Lee A, Farrer MJ, Stoessl AJ, Sossi V. Measuring dopaminergic function in the 6-OHDA-lesioned rat: a comparison of PET and microdialysis. EJNMMI Res 2013; 3:69. [PMID: 24088510 PMCID: PMC3875899 DOI: 10.1186/2191-219x-3-69] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/23/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND [18 F]fluorodopa (FDOPA) positron emission tomography (PET) allows assessment of levodopa (LDOPA) metabolism and is widely used to study Parkinson's disease. We examined how [18 F]FDOPA PET-derived kinetic parameters relate the dopamine (DA) and DA metabolite content of extracellular fluid measured by microdialysis to aid in the interpretation of data from both techniques. METHODS [18 F]FDOPA PET imaging and microdialysis measurements were performed in unilaterally 6-hydroxydopamine-lesioned rats (n = 8) and normal control rats (n = 3). Microdialysis testing included baseline measurements and measurements following acute administration of LDOPA. PET imaging was also performed using [11C]dihydrotetrabenazine (DTBZ), which is a ligand for the vesicular monoamine transporter marker and allowed assessment of denervation severity. RESULTS The different methods provided highly correlated data. Lesioned rats had reduced DA metabolite concentrations ipsilateral to the lesion (p < 0.05 compared to controls), with the concentration being correlated with FDOPA's effective distribution volume ratio (EDVR; r = 0.86, p < 0.01) and DTBZ's binding potential (BPND; r = 0.89, p < 0.01). The DA metabolite concentration in the contralateral striatum of severely (>80%) lesioned rats was lower (p < 0.05) than that of less severely lesioned rats (<80%) and was correlated with the ipsilateral PET measures (r = 0.89, p < 0.01 for BPND) but not with the contralateral PET measures. EDVR and BPND in the contralateral striatum were not different from controls and were not correlated with the denervation severity. CONCLUSIONS The demonstrated strong correlations between the PET and microdialysis measures can aid in the interpretation of [18 F]FDOPA-derived kinetic parameters and help compare results from different studies. The contralateral striatum was affected by the lesioning and so cannot always serve as an unaffected control.
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Affiliation(s)
- Matthew D Walker
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Katherine Dinelle
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Rick Kornelsen
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Anna Lee
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Matthew J Farrer
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6H 3N1, Canada
| | - A Jon Stoessl
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
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175
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Fukumoto S, Hanazono K, Komatsu T, Ueno H, Kadosawa T, Iwano H, Uchide T. L-type amino acid transporter 1 (LAT1): A new therapeutic target for canine mammary gland tumour. Vet J 2013; 198:164-9. [DOI: 10.1016/j.tvjl.2013.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 06/21/2013] [Accepted: 06/25/2013] [Indexed: 10/26/2022]
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176
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Harris SM, Davis JC, Snyder SE, Butch ER, Vavere AL, Kocak M, Shulkin BL. Evaluation of the biodistribution of 11C-methionine in children and young adults. J Nucl Med 2013; 54:1902-8. [PMID: 24050936 DOI: 10.2967/jnumed.112.118125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The purpose of this study was to evaluate the biodistribution of (11)C-labeled methionine in non-tumor-involved organs in pediatric patients studied for malignant diseases. METHODS Ninety-three children and young adults with known or suspected malignancies underwent (11)C-methionine PET and CT scans. Imaging began 5-15 min after injection of 740 MBq (20 mCi) per 1.7 m(2) of body surface area. Images were acquired from the top of the head through the mid thighs. Standardized uptake values were determined using regions of interest drawn on the CT image and transferred to the corresponding transverse PET slice. RESULTS The highest concentrations of (11)C-methionine were found in the pancreas and liver. Less intense uptake was seen in other regions, such as the salivary glands, tonsils, and bone marrow. There was little uptake in the lungs, fat (including brown adipose tissue), and muscle. Uptake in bone marrow, parotid glands, and tonsils was slightly but statistically significantly higher in men than women. Testicular, bone marrow, and left ventricular uptake increased with age. There was little variability statistically between comparisons of uptake change and groupings of age, race, sex, and patients studied at the time of diagnosis versus previously treated patients. CONCLUSION High uptake of (11)C-methionine is reliably found in the pancreas and liver, consistent with the anabolic functions of these organs. Low uptake in the brain, neck, chest, pelvis, and extremities will facilitate tumor localization in those areas. However, intense uptake in the upper abdomen may limit the diagnostic utility of (11)C-methionine in that area.
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Affiliation(s)
- Sebastian M Harris
- Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
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177
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Fukumoto S, Hanazono K, Fu DR, Endo Y, Kadosawa T, Iwano H, Uchide T. A new treatment for human malignant melanoma targeting L-type amino acid transporter 1 (LAT1): A pilot study in a canine model. Biochem Biophys Res Commun 2013; 439:103-8. [DOI: 10.1016/j.bbrc.2013.08.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/16/2022]
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178
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Mehravi B, Ahmadi M, Amanlou M, Mostaar A, Ardestani MS, Ghalandarlaki N. Cellular uptake and imaging studies of glycosylated silica nanoprobe (GSN) in human colon adenocarcinoma (HT 29 cell line). Int J Nanomedicine 2013; 8:3209-16. [PMID: 23986637 PMCID: PMC3754764 DOI: 10.2147/ijn.s44815] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose In recent years, molecular imaging by magnetic resonance imaging (MRI) has gained prominence in the detection of tumor cells. The scope of this study is on molecular imaging and on the cellular uptake study of a glycosylated silica nanoprobe (GSN). Methods In this study, intracellular uptake (HT 29 cell line) of GSN was analyzed quantitatively and qualitatively with inductively coupled plasma atomic emission spectroscopy, flow cytometry, and fluorescent microscopy. In vitro and in vivo relaxometry of this nanoparticle was determined using a 3 Tesla MRI; biodistribution of GSN and Magnevist® were measured in different tissues. Results Results suggest that the cellular uptake of GSN was about 70%. The r1 relaxivity of this nanoparticle in the cells was measured to be 12.9 ± 1.6 mM−1 s−1 and on a per lanthanide gadolinium (Gd3+) basis. Results also indicate an average cellular uptake of 0.7 ± 0.009 pg Gd3+ per cell. It should be noted that 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay demonstrated that the cells were effectively labeled without cytotoxicity, and that using MRI for quantitative estimation of delivery and uptake of targeted contrast agents and early detection of human colon cancer cells using targeted contrast agents, is feasible. Conclusion These results showed that GSN provided a critical guideline in selecting these nanoparticles as an appropriate contrast agent for nanomedicine applications.
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Affiliation(s)
- Bita Mehravi
- Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Blood-brain barrier transport of an essential amino acid after cerebral ischemia reperfusion injury. ACTA NEUROCHIRURGICA. SUPPLEMENT 2013; 118:297-302. [PMID: 23564153 DOI: 10.1007/978-3-7091-1434-6_58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Under pathophysiological conditions such as -cerebral ischemia-reperfusion (IR), damage to cerebrovascular endothelial cells causes alterations in the blood-brain barrier (BBB) function that can exacerbate neuronal cell injury and death. Clarifying changes in BBB transport in the early period of IR is important for understanding BBB function during therapy after cerebral ischemia. The present study was aimed at clarifying changes during IR in the BBB transport of L-phenylalanine (Phe) as a substrate of L-type amino acid transporter 1. An IR model was produced in mice by blood recirculation following occlusion of the middle cerebral artery. Permeability of the BBB to [(3)H]Phe was measured after IR injury using the brain perfusion method. Confocal microscopy of the IR injury showed no brain penetration of fluorescent tracer, thus confirming BBB integrity during 45 min of ischemia. Tight junction opening was not observed at 30 min after reperfusion following ischemia for 45 min. At the time of IR, [(3)H]Phe uptake into the brain appeared saturated. The Michaelis constant and maximum transport velocity in the IR group was reduced by 22 % compared with those in controls. These results suggest that the intrinsic transport clearance of Phe is slightly decreased in the early phase of IR.
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180
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Diagnostic usefulness of an amino acid tracer, α-[N-methyl-(11)C]-methylaminoisobutyric acid ( (11)C-MeAIB), in the PET diagnosis of chest malignancies. Ann Nucl Med 2013; 27:808-21. [PMID: 23824782 PMCID: PMC3830191 DOI: 10.1007/s12149-013-0750-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 06/17/2013] [Indexed: 12/03/2022]
Abstract
Objectives Although positron emission tomography (PET) using [18F]-fluoro-2-deoxy-d-glucose (18F-FDG) is established as one of the first-choice imaging modalities in the diagnosis of chest malignancies, there are several problems to solve in clinical practice, such as false positive uptake in inflammatory diseases. The aim of this study was to evaluate the clinical usefulness of an amino acid tracer, α-[N-methyl-11C]-methylaminoisobutyric acid (11C-MeAIB), in the diagnosis of chest malignancies, in combination with 18F-FDG. Setting Fifty-nine cases (57 patients, 66 ± 12 years old) who consulted to our institution for the wish to receive differential diagnosis of chest diseases were included. Purpose of the studies were as follows: differential diagnosis of newly developed lung nodules, n = 22; newly developed mediastinal lesions, n = 20; and both, n = 17 (including lung cancer: n = 19, lymphoma: n = 1, other cancers: n = 2, sarcoidosis: n = 15, non-specific inflammation: n = 18, other inflammatory: n = 4, respectively). Whole-body static PET or PET/CT scan was performed 20 and 50 min after the IV injection of 11C-MeAIB and 18F-FDG, respectively. Results 11C-MeAIB uptake of malignant and benign lesions was statistically different both in pulmonary nodules (p < 0.005) and in mediastinal lesions (p < 0.0005). In visual differential diagnosis, 11C-MeAIB showed higher results (specificity: 73 %, accuracy: 81 %), compared to those in 18F-FDG (60, 73 %, respectively). In cases of sarcoidosis, 11C-MeAIB showed higher specificity (80 %) with lower uptake (1.8 ± 0.7) in contrast to the lower specificity (60 %) with higher uptake of 18F-FDG (7.3 ± 4.5). Conclusions 11C-MeAIB PET/CT was useful in the differential diagnosis of pulmonary and mediastinal mass lesions found on CT. 11C-MeAIB PET or PET/CT showed higher specificity than that of 18F-FDG PET/CT in differentiating between benign and malignant disease. Our data suggest that the combination of 18F-FDG and 11C-MeAIB may improve the evaluation of chest lesions, when CT and 18F-FDG PET/CT are equivocal.
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181
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Dickens D, Webb SD, Antonyuk S, Giannoudis A, Owen A, Rädisch S, Hasnain SS, Pirmohamed M. Transport of gabapentin by LAT1 (SLC7A5). Biochem Pharmacol 2013; 85:1672-83. [DOI: 10.1016/j.bcp.2013.03.022] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/26/2013] [Accepted: 03/27/2013] [Indexed: 12/28/2022]
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182
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Zimmermann LT, Santos DB, Naime AA, Leal RB, Dórea JG, Barbosa F, Aschner M, Rocha JBT, Farina M. Comparative study on methyl- and ethylmercury-induced toxicity in C6 glioma cells and the potential role of LAT-1 in mediating mercurial-thiol complexes uptake. Neurotoxicology 2013; 38:1-8. [PMID: 23727015 DOI: 10.1016/j.neuro.2013.05.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 11/30/2022]
Abstract
Various forms of mercury possess different rates of absorption, metabolism and excretion, and consequently, toxicity. Methylmercury (MeHg) is a highly neurotoxic organic mercurial. Human exposure is mostly due to ingestion of contaminated fish. Ethylmercury (EtHg), another organic mercury compound, has received significant toxicological attention due to its presence in thimerosal-containing vaccines. This study was designed to compare the toxicities induced by MeHg and EtHg, as well as by their complexes with cysteine (MeHg-S-Cys and EtHg-S-Cys) in the C6 rat glioma cell line. MeHg and EtHg caused significant (p<0.0001) decreases in cellular viability when cells were treated during 30min with each mercurial following by a washing period of 24h (EC50 values of 4.83 and 5.05μM, respectively). Significant cytotoxicity (p<0.0001) was also observed when cells were treated under the same conditions with MeHg-S-Cys and EtHg-S-Cys, but the respective EC50 values were significantly increased (11.2 and 9.37μM). l-Methionine, a substrate for the l-type neutral amino acid carrier transport (LAT) system, significantly protected against the toxicities induced by both complexes (MeHg-S-Cys and EtHg-S-Cys). However, no protective effects of l-methionine were observed against MeHg and EtHg toxicities. Corroborating these findings, l-methionine significantly decreased mercurial uptake when cells were exposed to MeHg-S-Cys (p=0.028) and EtHg-S-Cys (p=0.023), but not to MeHg and EtHg. These results indicate that the uptake of MeHg-S-Cys and EtHg-S-Cys into C6 cells is mediated, at least in part, through the LAT system, but MeHg and EtHg enter C6 cells by mechanisms other than LAT system.
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Affiliation(s)
- Luciana T Zimmermann
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
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183
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Schweikhard ES, Ziegler CM. Amino acid secondary transporters: toward a common transport mechanism. CURRENT TOPICS IN MEMBRANES 2013. [PMID: 23177982 DOI: 10.1016/b978-0-12-394316-3.00001-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Solute carriers (SLC) that transport amino acids are key players in health and diseases in humans. Their prokaryotic relatives are often involved in essential physiological processes in microorganisms, e.g. in homeostasis and acidic/osmotic stress response. High-resolution X-ray structures of the sequence-unrelated amino acid transporters unraveled a striking structural similarity between carriers, which were formerly assigned to different families. The highly conserved fold is characterized by two inverted structural repeats of five transmembrane helices each and indicates common mechanistic transport concepts if not an evolutionary link among a large number of amino acid transporters. Therefore, these transporters are classified now into the structural amino acid-polyamine-organocation superfamily (APCS). The APCS includes among others the mammalian SLC6 transporters and the heterodimeric SLC7/SLC3 transporters. However, it has to be noted that the APCS is not limited entirely to amino acid transporters but contains also transporters for, e.g. amino acid derivatives and sugars. For instance, the betaine-choline-carnitine transporter family of bacterial activity-regulated Na(+)- and H(+)-coupled symporters for glycine betaine and choline is also part of this second largest structural superfamily. The APCS fold provides different possibilities to transport the same amino acid. Arginine can be transported by an H(+)-coupled symport or by antiport mechanism in exchange against agmatine for example. The convergence of the mechanistic concept of transport under comparable physiological conditions allows speculating if structurally unexplored amino acid transporters, e.g. the members of the SLC36 and SLC38 family, belong to the APCS, too. In the kidney, which is an organ that depends critically on the regulated amino acid transport, these different SLC transporters have to work together to account for proper function. Here, we will summarize the basic concepts of Na(+)- and H(+)-coupled amino acid symport and amino acid-product antiport in the light of the respective physiological requirements.
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Affiliation(s)
- Eva S Schweikhard
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
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185
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Kolodziej L. Investigation of the kynurenine pathway in Indoleamine 2, 3 dioxygenase deficient mice with inflammatory arthritis. Transgenic Res 2013; 22:1049-54. [PMID: 23417792 PMCID: PMC3781305 DOI: 10.1007/s11248-013-9696-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Accepted: 02/04/2013] [Indexed: 12/17/2022]
Abstract
Tryptophan is an essential amino acid involved in the protein synthesis, cognition, and immunity. Oxidative catabolism of tryptophan is executed by the sets of biochemical reactions collectively referred to as the kynurenine pathway. In the immune system, two distinct enzymes, Indoleamne 2,3 dioxygenase 1 (IDO1) and Indoleamine 2, 3 dioxygenase 2 (IDO2) can initiate metabolic flux through the kynurenine pathway. Rheumatoid arthritis is an autoimmune disease driven by the exacerbated immune response towards self antigens and characterized by the chronic inflammatory reaction of the diarthrodial joints. Collagen induced arthritis (CIA) is an animal model of rheumatoid arthritis. Using CIA in wild type (WT) and mice deficient with Indoleamine 2,3 dioxygenase (Ido1KO), it was of interest to test the impact of Ido1 deletion on the concentration of tryptophan and its catabolites as well as on mRNA expression for other genes on the kynurenine pathway. Here, when compared with samples taken from naïve WT animals and those with CIA, it was found that only in the inguinal lymph nodes (iLN) taken from Ido1KO mice with CIA tryptophan concentration was significantly increased. In contrast, mRNA expression for Ido2 was decreased in naïve as well as in the diseased iLN taken from Ido1KO mice. Deletion of Ido1 and reduced mRNA expression for Ido2 neither affected the concentration of the downstream metabolites of tryptophan nor mRNA expression for downstream genes on the kynurenine pathway in iLN. Moreover, the concentration of kynurenine in sera of mice with CIA was significantly decreased in Ido1KO mice with arthritis.
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Affiliation(s)
- Lukasz Kolodziej
- The Kennedy Institute of Rheumatology Division, Imperial College London, Arthritis Research UK Building, Charing Cross Hospital Campus, 65 Aspenlea Road, London, W6 8LH, UK,
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Kalvass JC, Polli JW, Bourdet DL, Feng B, Huang SM, Liu X, Smith QR, Zhang LK, Zamek-Gliszczynski MJ. Why Clinical Modulation of Efflux Transport at the Human Blood–Brain Barrier Is Unlikely: The ITC Evidence-Based Position. Clin Pharmacol Ther 2013; 94:80-94. [DOI: 10.1038/clpt.2013.34] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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187
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In vitro, in vivo and in silico models of drug distribution into the brain. J Pharmacokinet Pharmacodyn 2013; 40:301-14. [DOI: 10.1007/s10928-013-9303-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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188
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Structure–activity relationship study of compounds binding to large amino acid transporter 1 (LAT1) based on pharmacophore modeling and in situ rat brain perfusion. Eur J Pharm Sci 2013; 48:523-31. [DOI: 10.1016/j.ejps.2012.11.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/26/2012] [Accepted: 11/27/2012] [Indexed: 12/13/2022]
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189
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Engström K, Ameer S, Bernaudat L, Drasch G, Baeuml J, Skerfving S, Bose-O'Reilly S, Broberg K. Polymorphisms in genes encoding potential mercury transporters and urine mercury concentrations in populations exposed to mercury vapor from gold mining. ENVIRONMENTAL HEALTH PERSPECTIVES 2013; 121:85-91. [PMID: 23052037 PMCID: PMC3553430 DOI: 10.1289/ehp.1204951] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 10/09/2012] [Indexed: 05/03/2023]
Abstract
BACKGROUND Elemental mercury (Hg0) is widely used in small-scale gold mining. Persons working or living in mining areas have high urinary concentrations of Hg (U-Hg). Differences in genes encoding potential Hg-transporters may affect uptake and elimination of Hg. OBJECTIVE We aimed to identify single nucleotide polymorphisms (SNPs) in Hg-transporter genes that modify U-Hg. METHODS Men and women (1,017) from Indonesia, the Philippines, Tanzania, and Zimbabwe were classified either as controls (no Hg exposure from gold mining) or as having low (living in a gold-mining area) or high exposure (working as gold miners). U-Hg was analyzed by cold-vapor atomic absorption spectrometry. Eighteen SNPs in eight Hg-transporter genes were analyzed. RESULTS U-Hg concentrations were higher among ABCC2/MRP2 rs1885301 A-allele carriers than among GG homozygotes in all populations, though differences were not statistically significant in most cases. MRP2 SNPs showed particularly strong associations with U-Hg in the subgroup with highest exposure (miners in Zimbabwe), whereas rs1885301 A-allele carriers had higher U-Hg than GG homozygotes [geometric mean (GM): 36.4 µg/g creatinine vs. 21.9; p = 0.027], rs2273697 GG homozygotes had higher U-Hg than A-allele carriers (GM: 37.4 vs. 16.7; p = 0.001), and rs717620 A-allele carriers had higher U-Hg than GG homozygotes (GM: 83 vs. 28; p = 0.084). The SLC7A5/LAT1 rs33916661 GG genotype was associated with higher U-Hg in all populations (statistically significant for all Tanzanians combined). SNPs in SLC22A6/OAT1 (rs4149170) and SLC22A8/OAT3 (rs4149182) were associated with U-Hg mainly in the Tanzanian study groups. CONCLUSIONS SNPs in putative Hg-transporter genes may influence U-Hg concentrations.
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Affiliation(s)
- Karin Engström
- Department of Laboratory Medicine, Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden.
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Kong FL, Zhang Y, Young DP, Yu DF, Yang DJ. Development of (99m)Tc-EC-tyrosine for early detection of breast cancer tumor response to the anticancer drug melphalan. Acad Radiol 2013; 20:41-51. [PMID: 22963724 DOI: 10.1016/j.acra.2012.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 08/01/2012] [Accepted: 08/01/2012] [Indexed: 02/03/2023]
Abstract
RATIONALE AND OBJECTIVES Radiolabeled tyrosine analogues that have been successfully used in tumor imaging accumulate in tumor cells via an upregulated L-type amino acid transporter system. The anticancer drug melphalan is an L-type amino acid transporter substrate. Therefore, radiolabeled tyrosine analogues may have great potential in evaluating treatment responses to melphalan. In this study, a (99m)Tc-labeled tyrosine analogue, (99m)Tc tyrosine using N,N'-ethylene-di-L-cysteine (EC) as a chelator, was developed and its potential for noninvasively assessing tumors' early response to melphalan determined. MATERIALS AND METHODS EC-tyrosine was synthesized in a three-step procedure and labeled with (99m)Tc. To assess cellular uptake kinetics, the percentage uptake of (99m)Tc-EC-tyrosine in the rat breast cancer cell line 13762 was measured. Planar imaging was performed in rats with 13762 cell-derived tumors. To determine the transport mechanisms of (99m)Tc-EC-tyrosine, a competitive inhibition study using L-tyrosine as an inhibitor was performed in vitro and in vivo. To assess tumors' response to melphalan, tumor-bearing rats were treated with different doses of melphalan, and planar imaging was performed 0 and 3 days after treatment. Immunohistochemical analyses were conducted to determine expressions of L-type amino acid transporter 1 and cellular proliferation marker Ki-67. RESULTS L-tyrosine significantly inhibited (99m)Tc-EC-tyrosine uptake in vitro and in vivo. Tumor volume decreased in a dose-dependent manner with melphalan, and tumor/muscle ratios of (99m)Tc-EC-tyrosine were significantly reduced in treated groups. Immunohistochemical data indicated that about 70% of tumor cells in the melphalan-treated groups underwent apoptosis, and the changes in tumor/muscle ratios reflected the decreased percentage of viable cells in treated tumors. CONCLUSIONS These findings suggest that (99m)Tc-EC-tyrosine has great potential for monitoring tumor response to melphalan in breast tumor-bearing rats.
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Affiliation(s)
- Fan-Lin Kong
- Department of Experimental Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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191
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Youland RS, Kitange GJ, Peterson TE, Pafundi DH, Ramiscal JA, Pokorny JL, Giannini C, Laack NN, Parney IF, Lowe VJ, Brinkmann DH, Sarkaria JN. The role of LAT1 in (18)F-DOPA uptake in malignant gliomas. J Neurooncol 2013; 111:11-8. [PMID: 23086431 PMCID: PMC3907171 DOI: 10.1007/s11060-012-0986-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/10/2012] [Indexed: 01/11/2023]
Abstract
Positron emission tomography (PET) imaging with the amino acid tracer 6-(18)F-fluoro-L-3,4-dihydroxy-phenylalanine ((18)F-DOPA) may provide better spatial and functional information in human gliomas than CT or MRI alone. The L-type amino acid transporter 1 (LAT1) is responsible for membrane transport of large neutral amino acids in normal cells. This study assessed the relationship between LAT1 expression and (18)F-DOPA uptake in human astrocytomas. Endogenous LAT1 expression was measured in established glioblastoma (GBM) cell lines and primary GBM xenografts using Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Uptake of (18)F-DOPA was approximated in vitro using (3)H-L-DOPA as an analog. Uptake of (3)H-L-DOPA was assessed in cells expressing LAT1 shRNA or LAT1 siRNA and compared to non-targeted (NT) control shRNA or siRNA sequences, respectively. To demonstrate the clinical relevance of these findings, LAT1 immunofluorescence staining was compared with corresponding regions of (18)F-DOPA PET uptake in patients with newly diagnosed astrocytomas. LAT1 mRNA and protein expression varies in GBM, and the extent of (3)H-L-DOPA uptake was positively correlated with endogenous LAT1 expression. Stable shRNA-mediated LAT1 knockdown in T98 and GBM28 reduced (3)H-L-DOPA uptake relative to NT shRNA by 57 (P < 0.0001) and 52 % (P < 0.001), respectively. Transient siRNA-mediated LAT1 knockdown in T98 reduced (3)H-L-DOPA uptake relative to NT siRNA up to 68 % (P < 0.01). In clinical samples, LAT1 expression positively correlated with (18)F-DOPA PET uptake (P = 0.04). Expression of LAT1 is strongly associated with (3)H-L-DOPA uptake in vitro and (18)F-DOPA uptake in patient biopsy samples. These results define LAT1 as a key determinant of (18)F-DOPA accumulation in GBM.
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Affiliation(s)
- Ryan S Youland
- College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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FUKUMOTO S, HANAZONO K, KOMATSU T, IWANO H, KADOSAWA T, UCHIDE T. L-Type Amino Acid Transporter 1 (LAT1) Expression in Canine Mammary Gland Tumors. J Vet Med Sci 2013; 75:431-7. [DOI: 10.1292/jvms.12-0356] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Shinya FUKUMOTO
- Veterinary Internal Medicine, Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
| | - Kiwamu HANAZONO
- Veterinary Internal Medicine, Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
| | - Takahiro KOMATSU
- Veterinary Oncology, Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
| | - Hidetomo IWANO
- Veterinary Biochemistry, Department of Basic Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
| | - Tsuyoshi KADOSAWA
- Veterinary Oncology, Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
| | - Tsuyoshi UCHIDE
- Veterinary Internal Medicine, Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069–8501, Japan
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193
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Brodnik Z, Bongiovanni R, Double M, Jaskiw GE. Increased tyrosine availability increases brain regional DOPA levels in vivo. Neurochem Int 2012; 61:1001-6. [DOI: 10.1016/j.neuint.2012.07.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 06/30/2012] [Accepted: 07/13/2012] [Indexed: 10/28/2022]
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194
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Comparison of brain capillary endothelial cell-based and epithelial (MDCK-MDR1, Caco-2, and VB-Caco-2) cell-based surrogate blood–brain barrier penetration models. Eur J Pharm Biopharm 2012; 82:340-51. [DOI: 10.1016/j.ejpb.2012.07.020] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/14/2012] [Accepted: 07/31/2012] [Indexed: 12/18/2022]
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195
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Bongiovanni R, Kyser AN, Jaskiw GE. Tyrosine depletion lowers in vivo DOPA synthesis in ventral hippocampus. Eur J Pharmacol 2012; 696:70-6. [PMID: 23022716 DOI: 10.1016/j.ejphar.2012.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 09/05/2012] [Accepted: 09/17/2012] [Indexed: 10/27/2022]
Abstract
In vivo dopamine synthesis in the medial prefrontal cortex of the rat is sensitive to the availability of tyrosine. Whether other limbic cortical dopamine terminal regions are similarly tyrosine-dependent is not known. In this study we examined the effects of tyrosine depletion on dopamine synthesis and catecholamine levels in the ventral hippocampus. A tyrosine- and phenylalanine-free neutral amino acid mixture was used to lower brain tyrosine levels in rats undergoing in vivo microdialysis. In one group, NSD-1015 was included in perfusate to permit measurement of DOPA levels. In a second group, NSD-1015 was not included in perfusate so that catecholamine levels could be assayed. Tyrosine depletion significantly lowered DOPA levels in the NSD-1015 treated group and lowered DOPAC but not dopamine or noradrenaline levels in the group not exposed to NSD-1015. We conclude that while catecholamine synthesis in the ventral hippocampus declines when tyrosine availability is lowered, under basal conditions, compensatory mechanisms are able to maintain stable extracellular catecholamine levels.
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Affiliation(s)
- Rodolfo Bongiovanni
- Psychiatry Service, Louis Stokes Cleveland VA Medical Center, 10701 East Blvd., Cleveland, Ohio 44106, USA.
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196
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Di L, Artursson P, Avdeef A, Ecker GF, Faller B, Fischer H, Houston JB, Kansy M, Kerns EH, Krämer SD, Lennernäs H, Sugano K. Evidence-based approach to assess passive diffusion and carrier-mediated drug transport. Drug Discov Today 2012; 17:905-12. [DOI: 10.1016/j.drudis.2012.03.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/20/2012] [Accepted: 03/30/2012] [Indexed: 10/28/2022]
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197
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The role of amino acid transporters in GSH synthesis in the blood-brain barrier and central nervous system. Neurochem Int 2012; 61:405-14. [PMID: 22634224 DOI: 10.1016/j.neuint.2012.05.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/17/2012] [Accepted: 05/15/2012] [Indexed: 12/22/2022]
Abstract
Glutathione (GSH) plays a critical role in protecting cells from oxidative stress and xenobiotics, as well as maintaining the thiol redox state, most notably in the central nervous system (CNS). GSH concentration and synthesis are highly regulated within the CNS and are limited by availability of the sulfhydryl amino acid (AA) l-cys, which is mainly transported from the blood, through the blood-brain barrier (BBB), and into neurons. Several antiporter transport systems (e.g., x(c)(-), x(-)(AG), and L) with clearly different luminal and abluminal distribution, Na(+), and pH dependency have been described in brain endothelial cells (BEC) of the BBB, as well as in neurons, astrocytes, microglia and oligodendrocytes from different brain structures. The purpose of this review is to summarize information regarding the different AA transport systems for l-cys and its oxidized form l-cys(2) in the CNS, such as expression and activity in blood-brain barrier endothelial cells, astrocytes and neurons and environmental factors that modulate transport kinetics.
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198
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Vlieghe P, Khrestchatisky M. Medicinal chemistry based approaches and nanotechnology-based systems to improve CNS drug targeting and delivery. Med Res Rev 2012; 33:457-516. [PMID: 22434495 DOI: 10.1002/med.21252] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The central nervous system (CNS) is protected by various barriers, which regulate nervous tissue homeostasis and control the selective and specific uptake, efflux, and metabolism of endogenous and exogenous molecules. Among these barriers is the blood-brain barrier (BBB), a physical and physiological barrier that filters very efficiently and selectively the entry of compounds from the blood to the brain and protects nervous tissue from harmful substances and infectious agents present in the bloodstream. The BBB also prevents the entry of potential drugs. As a result, various drug targeting and delivery strategies are currently being developed to enhance the transport of drugs from the blood to the brain. Following a general introduction, we briefly overview in this review article the fundamental physiological properties of the BBB. Then, we describe current strategies to bypass the BBB (i.e., invasive methods, alternative approaches, and temporary opening) and to cross it (i.e., noninvasive approaches). This section is followed by a chapter addressing the chemical and technological solutions developed to cross the BBB. A special emphasis is given to prodrug-targeting approaches and targeted nanotechnology-based systems, two promising strategies for BBB targeting and delivery of drugs to the brain.
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Affiliation(s)
- Patrick Vlieghe
- VECT-HORUS S.A.S., Faculté de Médecine Secteur Nord, CS80011, Boulevard Pierre Dramard, 13344 Marseille Cedex 15, France.
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199
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Kartal-Hodzic A, Marvola T, Schmitt M, Harju K, Peltoniemi M, Sivén M. Permeability and toxicity characteristics of L-cysteine and 2-methyl-thiazolidine-4-carboxylic acid in Caco-2 cells. Pharm Dev Technol 2012; 18:1288-93. [PMID: 22356486 DOI: 10.3109/10837450.2012.659253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Acetaldehyde is a known mutagenic substance and has been classified as a group-one carcinogen by the WHO. It is possible to bind acetaldehyde locally in the gastrointestinal (GI) tract with the semi-essential amino acid l-cysteine, which reacts covalently with acetaldehyde and forms compound 2-methyl-thiozolidine-4-carboxylic acid (MTCA). The Caco-2 cell line was used to determine the permeation of l-cysteine and MTCA, as well as the possible cell toxicity of both substances. Neither of the substances permeated through the Caco-2 cells at the concentrations used in this study, and only the highest concentration of MTCA affected the viability of the cells in the MTT (3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide) test. These results showed that when l-cysteine is administered in formulations releasing it locally in the lower parts of GI tract, it is not absorbed but can react with acetaldehyde, and that neither l-cysteine nor MTCA is harmful to the cells when present locally in the upper parts of GI tract. This study also shows that MTCA is sensitive at a lower pH of 5.5. Since stable MTCA is desired in different parts of the GI tract, this observation raises concern over the influence of lower pH on l-cysteine-containing product ability to bind and eliminate carcinogenic acetaldehyde.
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Affiliation(s)
- Alma Kartal-Hodzic
- Faculty of Pharmacy, Division of Biopharmaceutics and Pharmacokinetics, University of Helsinki, Helsinki, Finland.
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200
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Ravenstijn PG, Drenth HJ, O'Neill MJ, Danhof M, de Lange EC. Evaluation of blood-brain barrier transport and CNS drug metabolism in diseased and control brain after intravenous L-DOPA in a unilateral rat model of Parkinson's disease. Fluids Barriers CNS 2012; 9:4. [PMID: 22316420 PMCID: PMC3298802 DOI: 10.1186/2045-8118-9-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Accepted: 02/08/2012] [Indexed: 11/16/2022] Open
Abstract
Background Changes in blood-brain barrier (BBB) functionality have been implicated in Parkinson's disease. This study aimed to investigate BBB transport of L-DOPA transport in conjunction with its intra-brain conversion, in both control and diseased cerebral hemispheres in the unilateral rat rotenone model of Parkinson's disease. Methods In Lewis rats, at 14 days after unilateral infusion of rotenone into the medial forebrain bundle, L-DOPA was administered intravenously (10, 25 or 50 mg/kg). Serial blood samples and brain striatal microdialysates were analysed for L-DOPA, and the dopamine metabolites DOPAC and HVA. Ex-vivo brain tissue was analyzed for changes in tyrosine hydroxylase staining as a biomarker for Parkinson's disease severity. Data were analysed by population pharmacokinetic analysis (NONMEM) to compare BBB transport of L-DOPA in conjunction with the conversion of L-DOPA into DOPAC and HVA, in control and diseased cerebral hemisphere. Results Plasma pharmacokinetics of L-DOPA could be described by a 3-compartmental model. In rotenone responders (71%), no difference in L-DOPA BBB transport was found between diseased and control cerebral hemisphere. However, in the diseased compared with the control side, basal microdialysate levels of DOPAC and HVA were substantially lower, whereas following L-DOPA administration their elimination rates were higher. Conclusions Parkinson's disease-like pathology, indicated by a huge reduction of tyrosine hydroxylase as well as by substantially reduced levels and higher elimination rates of DOPAC and HVA, does not result in changes in BBB transport of L-DOPA. Taking the results of this study and that of previous ones, it can be concluded that changes in BBB functionality are not a specific characteristic of Parkinson's disease, and cannot account for the decreased benefit of L-DOPA at later stages of Parkinson's disease.
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