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Stacey D, Redlich R, Büschel A, Opel N, Grotegerd D, Zaremba D, Dohm K, Bürger C, Meinert SL, Förster K, Repple J, Kaufmann C, Kugel H, Heindel W, Arolt V, Dannlowski U, Baune BT. TNF receptors 1 and 2 exert distinct region-specific effects on striatal and hippocampal grey matter volumes (VBM) in healthy adults. GENES BRAIN AND BEHAVIOR 2016; 16:352-360. [PMID: 27528091 DOI: 10.1111/gbb.12318] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/20/2016] [Accepted: 08/10/2016] [Indexed: 12/23/2022]
Abstract
Tumour necrosis factor alpha (TNFα) has been implicated in the pathophysiology of neurodegenerative and neuropsychiatric disease, with research highlighting a role for TNFα in hippocampal and striatal regulation. TNFα signals are primarily transduced by TNF receptors 1 and 2 (TNFR1 and TNFR2), encoded by TNFRSF1A and TNFRSF1B, which exert opposing effects on cell survival (TNFR1, neurodegenerative; TNFR2, neuroprotective). We therefore sought to explore the respective roles of TNFR1 and TNFR2 in the regulation of hippocampal and striatal morphology in an imaging genetics study. Voxel-based morphometry was used to analyse the associations between TNFRSF1A (rs4149576 and rs4149577) and TNFRSF1B (rs1061624) genotypes and grey matter structure. The final samples comprised a total of 505 subjects (mean age = 33.29, SD = 11.55 years; 285 females and 220 males) for morphometric analyses of rs1061624 and rs4149576, and 493 subjects for rs4149577 (mean age = 33.20, SD = 11.56 years; 281 females and 212 males). Analyses of TNFRSF1A single nucleotide polymorphisms (SNPs) rs4149576 and rs4149577 showed highly significant genotypic associations with striatal volume but not the hippocampus. Specifically, for rs4149576, G homozygotes were associated with reduced caudate nucleus volumes relative to A homozygotes and heterozygotes, whereas for rs4149577, reduced caudate volumes were observed in C homozygotes relative to T homozygotes and heterozygotes. Analysis of the TNFRSF1B SNP rs1061624 yielded a significant association with hippocampal but not with striatal volume, whereby G homozygotes were associated with increased volumes relative to A homozygotes and heterozygotes. Our findings indicate a role for TNFR1 in regulating striatal but not hippocampal morphology, as well as a complementary role for TNFR2 in hippocampal but not in striatal morphology.
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Affiliation(s)
- D Stacey
- Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - R Redlich
- Department of Psychiatry, University of Münster, Münster
| | - A Büschel
- Department of Psychiatry, University of Münster, Münster
| | - N Opel
- Department of Psychiatry, University of Münster, Münster
| | - D Grotegerd
- Department of Psychiatry, University of Münster, Münster
| | - D Zaremba
- Department of Psychiatry, University of Münster, Münster
| | - K Dohm
- Department of Psychiatry, University of Münster, Münster
| | - C Bürger
- Department of Psychiatry, University of Münster, Münster
| | - S L Meinert
- Department of Psychiatry, University of Münster, Münster
| | - K Förster
- Department of Psychiatry, University of Münster, Münster
| | - J Repple
- Department of Psychiatry, University of Münster, Münster
| | - C Kaufmann
- Department of Psychiatry, University of Münster, Münster
| | - H Kugel
- Department of Clinical Radiology, University of Münster, Münster
| | - W Heindel
- Department of Clinical Radiology, University of Münster, Münster
| | - V Arolt
- Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - U Dannlowski
- Department of Psychiatry, University of Münster, Münster.,Department of Psychiatry, University of Marburg, Marburg, Germany
| | - B T Baune
- Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
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Demirer GS, Okur AC, Kizilel S. Synthesis and design of biologically inspired biocompatible iron oxide nanoparticles for biomedical applications. J Mater Chem B 2015; 3:7831-7849. [PMID: 32262898 DOI: 10.1039/c5tb00931f] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During the last couple of decades considerable research efforts have been directed towards the synthesis and coating of iron oxide nanoparticles (IONPs) for biomedical applications. To address the current limitations, recent studies have focused on the design of new generation nanoparticle systems whose internalization and targeting capabilities have been improved through surface modifications. This review covers the most recent challenges and advances in the development of IONPs with enhanced quality, and biocompatibility for various applications in biotechnology and medicine.
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Affiliation(s)
- Gozde S Demirer
- Koc University, Chemical and Biological Engineering, Istanbul 34450, Turkey.
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Controlled Striatal DOPA Production From a Gene Delivery System in a Rodent Model of Parkinson's Disease. Mol Ther 2015; 23:896-906. [PMID: 25592335 DOI: 10.1038/mt.2015.8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/29/2014] [Indexed: 12/25/2022] Open
Abstract
Conventional symptomatic treatment for Parkinson's disease (PD) with long-term L-3,4-dihydroxyphenylalanine (DOPA) is complicated with development of drug-induced side effects. In vivo viral vector-mediated gene expression encoding tyrosine hydroxylase (TH) and GTP cyclohydrolase 1 (GCH1) provides a drug delivery strategy of DOPA with distinct advantages over pharmacotherapy. Since the brain alterations made with current gene transfer techniques are irreversible, the therapeutic approaches taken to the clinic should preferably be controllable to match the needs of each individual during the course of their disease. We used a recently described tunable gene expression system based on the use of destabilized dihydrofolate reductase (DD) and generated a N-terminally coupled GCH1 enzyme (DD-GCH1) while the TH enzyme was constitutively expressed, packaged in adeno-associated viral (AAV) vectors. Expression of DD-GCH1 was regulated by the activating ligand trimethoprim (TMP) that crosses the blood-brain barrier. We show that the resulting intervention provides a TMP-dose-dependent regulation of DOPA synthesis that is closely linked to the magnitude of functional effects. Our data constitutes the first proof of principle for controlled reconstitution of dopamine capacity in the brain and suggests that such next-generation gene therapy strategies are now mature for preclinical development toward use in patients with PD.
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Differential dopamine receptor occupancy underlies L-DOPA-induced dyskinesia in a rat model of Parkinson's disease. PLoS One 2014; 9:e90759. [PMID: 24614598 PMCID: PMC3948692 DOI: 10.1371/journal.pone.0090759] [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: 12/18/2013] [Accepted: 02/03/2014] [Indexed: 01/03/2023] Open
Abstract
Dyskinesia is a major side effect of an otherwise effective L-DOPA treatment in Parkinson's patients. The prevailing view for the underlying presynaptic mechanism of L-DOPA-induced dyskinesia (LID) suggests that surges in dopamine (DA) via uncontrolled release from serotonergic terminals results in abnormally high level of extracellular striatal dopamine. Here we used high-sensitivity online microdialysis and PET imaging techniques to directly investigate DA release properties from serotonergic terminals both in the parkinsonian striatum and after neuronal transplantation in 6-OHDA lesioned rats. Although L-DOPA administration resulted in a drift in extracellular DA levels, we found no evidence for abnormally high striatal DA release from serotonin neurons. The extracellular concentration of DA remained at or below levels detected in the intact striatum. Instead, our results showed that an inefficient release pool of DA associated with low D2 receptor binding remained unchanged. Taken together, these findings suggest that differential DA receptor activation rather than excessive release could be the underlying mechanism explaining LID seen in this model. Our data have important implications for development of drugs targeting the serotonergic system to reduce DA release to manage dyskinesia in patients with Parkinson's disease.
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Abstract
Development of motor and non-motor complications during the course of Parkinson's disease (PD) is a major challenge for therapeutic management. At advanced disease stages, patients frequently fluctuate between PD symptoms-such as bradykinesia-and dyskinesias, in response to fluctuations in drug concentrations. Continuous subcutaneous infusion of the dopamine agonist apomorphine or intestinal infusion of levodopa reduce such fluctuations in both pharmacokinetics and motor function. This is the basis for the concept of continuous drug delivery in PD, and the more theoretical concept of continuous dopaminergic stimulation. These expressions are sometimes used to describe a treatment that is more continuous in its pharmacokinetic profile or that produces more sustained effects, compared with immediate-release levodopa, i.e. not only pump treatments. For example, sustained-release formulations of levodopa or dopamine agonists, transdermal delivery of rotigotine, and addition of catechol-O-methyltransferase inhibitors or monoamine oxidase-B inhibitors have been developed with the aim to provide more continuous drug concentrations, sustained benefits and minimized side effects. Progress has been made, but there are still knowledge gaps regarding how these treatment alternatives can be optimally used. New treatments are currently being developed to provide the continuous drug delivery that is known to successfully alleviate motor and non-motor complications. Hopefully, although not yet proven, these new methods may also prevent or postpone some of the late-stage complications.
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Affiliation(s)
- Marina Senek
- Department of Neuroscience, Neurology, Uppsala University, SE-75185, Uppsala, Sweden
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Design of a single AAV vector for coexpression of TH and GCH1 to establish continuous DOPA synthesis in a rat model of Parkinson's disease. Mol Ther 2012; 20:1315-26. [PMID: 22294150 DOI: 10.1038/mt.2012.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Preclinical efficacy of continuous delivery of 3,4-dihydroxyphenylalanine (DOPA) with adeno-associated viral (AAV) vectors has recently been documented in animal models of Parkinson's disease (PD). So far, all studies have utilized a mix of two monocistronic vectors expressing either of the two genes, tyrosine hydroxylase (TH) and GTP cyclohydrolase-1 (GCH1), needed for DOPA production. Here, we present a novel vector design that enables efficient DOPA production from a single AAV vector in rats with complete unilateral dopamine (DA) lesions. Functional efficacy was assessed with drug-induced and spontaneous motor behavioral tests where vector-treated animals showed near complete and stable recovery within 1 month. Recovery of motor function was associated with restoration of extracellular DA levels as assessed by online microdialysis. Histological analysis showed robust transgene expression not only in the striatum but also in overlying cortical areas. In globus pallidus, we noted loss of NeuN staining, which might be due to different sensitivity in neuronal populations to transgene expression. Taken together, we present a single AAV vector design that result in efficient DOPA production and wide-spread transduction. This is a favorable starting point for continued translation toward a therapeutic application, although future studies need to carefully review target region, vector spread and dilution with this approach.
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