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de Paula Faria D, de Vries EFJ, Sijbesma JWA, Buchpiguel CA, Dierckx RAJO, Copray SCVM. PET imaging of glucose metabolism, neuroinflammation and demyelination in the lysolecithin rat model for multiple sclerosis. Mult Scler 2014; 20:1443-52. [DOI: 10.1177/1352458514526941] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Background: Injection of lysolecithin in the central nervous system results in demyelination accompanied by local activation of microglia and recruitment of monocytes. Positron-emission tomography (PET) imaging, using specific tracers, may be an adequate technique to monitor these events in vivo and therefore may become a tool for monitoring disease progression in multiple sclerosis (MS) patients. Objectives: The objective of this paper is to evaluate the potential of PET imaging in monitoring local lesions, using [11C]MeDAS, [11C]PK11195 and [18F]FDG as PET tracers for myelin density, microglia activation and glucose metabolism, respectively. Methods: Sprague-Dawley rats were stereotactically injected with either 1% lysolecithin or saline in the corpus callosum and striatum of the right brain hemisphere. PET imaging was performed three days, one week and four weeks after injection. Animals were terminated after PET imaging and the brains were explanted for (immuno)histochemical analysis. Results: PET imaging was able to detect local demyelination induced by lysolecithin in the corpus callosum and striatum with [11C]MeDAS and concomitant microglia activation and monocyte recruitment with [11C]PK11195. [18F]FDG imaging demonstrated that glucose metabolism was maintained in the demyelinated lesions. Conclusion: PET imaging with multiple tracers allows simultaneous in vivo monitoring of myelin density, neuroinflammation and brain metabolism in small MS-like lesions, indicating its potential to monitor disease progression in MS patients.
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Affiliation(s)
- Daniele de Paula Faria
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Erik FJ de Vries
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Jurgen WA Sijbesma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Carlos A Buchpiguel
- Center of Nuclear Medicine, University of São Paulo, University of São Paulo Medical School, Brazil
| | - Rudi AJO Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Sjef CVM Copray
- Department of Neuroscience, University of Groningen, University Medical Center Groningen, The Netherlands
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5
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Dyakin VV, Chen Y, Branch CA, Yuan A, Rao M, Kumar A, Peterhoff CM, Nixon RA. The contributions of myelin and axonal caliber to transverse relaxation time in shiverer and neurofilament-deficient mouse models. Neuroimage 2010; 51:1098-105. [PMID: 20226865 DOI: 10.1016/j.neuroimage.2010.03.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 03/01/2010] [Accepted: 03/03/2010] [Indexed: 01/17/2023] Open
Abstract
White matter disorders can involve injury to myelin or axons but the respective contribution of each to clinical course is difficult to evaluate non-invasively. Here, to develop a paradigm for further investigations of axonal pathology by MRI, we compared two genetic mouse models exhibiting relatively selective axonal or myelin deficits using quantitative MRI relaxography of the transverse relaxation times (T2) in vivo and ultrastructural morphometry. In HM-DKO mice, which lack genes encoding the heavy (NF-H) and medium (NF-M) subunits of neurofilaments, neurofilament content of large myelinated axons of the central nervous system (CNS) is markedly reduced in the absence of changes in myelin thickness and volume. In shiverer mutant mice, which lack functional myelin basic protein, CNS myelin sheath formation is markedly reduced but neurofilament content is normal. We observed increases in T2 in nearly all white matter in shiverer mice compared to their wild type, while more subtle increases in T2 were observed in HM-DKO in the corpus callosum. White matter T2 was generally greater in shiverer mice than HM-DKO mice. Ultrastructural morphometry of the corpus callosum, which exhibited the greatest T2 differences, confirmed that total cross-sectional area occupied by axons was similar in the two mouse models and that the major ultrastructural differences, determined by morphometry, were an absence of myelin and larger unmyelinated axons in shiverer mice and absence of neurofilaments in HM-DKO mice. Our findings indicate that T2 is strongly influenced by myelination state and axonal volume, while neurofilament structure within the intra-axonal compartment has a lesser effect upon single compartment T2 estimates.
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Affiliation(s)
- Victor V Dyakin
- Center for Dementia Research, Nathan Kline Institute Orangeburg, New York 10962, USA
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Lecrux C, McCabe C, Weir CJ, Gallagher L, Mullin J, Touzani O, Muir KW, Lees KR, Macrae IM. Effects of Magnesium Treatment in a Model of Internal Capsule Lesion in Spontaneously Hypertensive Rats. Stroke 2008; 39:448-54. [DOI: 10.1161/strokeaha.107.492934] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
The study aim was to assess the effects of magnesium sulfate (MgSO
4
) administration on white matter damage in vivo in spontaneously hypertensive rats.
Methods—
The left internal capsule was lesioned by a local injection of endothelin-1 (ET-1; 200 pmol) in adult spontaneously hypertensive rats. MgSO
4
was administered (300 mg/kg SC) 30 minutes before injection of ET-1, plus 200 mg/kg every hour thereafter for 4 hours. Infarct size was measured by T2-weighted magnetic resonance imaging (day 2) and histology (day 11), and functional recovery was assessed on days 3 and 10 by the cylinder and walking-ladder tests.
Results—
ET-1 application induced a small, localized lesion within the internal capsule. Despite reducing blood pressure, MgSO
4
did not significantly influence infarct volume (by magnetic resonance imaging: median, 2.1 mm
3
; interquartile range, 1.3 to 3.8, vs 1.6 mm
3
and 1.2 to 2.1, for the vehicle-treated group; by histology: 0.3 mm
3
and 0.2 to 0.9 vs 0.3 mm
3
and 0.2 to 0.5, respectively). Significant forelimb and hindlimb motor deficits were evident in the vehicle-treated group as late as day 10. These impairments were significantly ameliorated by MgSO
4
in both cylinder (left forelimb use,
P
<0.01 and both-forelimb use,
P
<0.03 vs vehicle) and walking-ladder (right hindlimb score,
P
<0.02 vs vehicle) tests.
Conclusions—
ET-1–induced internal capsule ischemia in spontaneously hypertensive rats represents a good model of lacunar infarct with small lesion size, minimal adverse effects, and a measurable motor deficit. Despite inducing mild hypotension, MgSO
4
did not significantly influence infarct size but reduced motor deficits, supporting its potential utility for the treatment of lacunar infarct.
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Affiliation(s)
- Clotilde Lecrux
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Christopher McCabe
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Christopher J. Weir
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Lindsay Gallagher
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Jim Mullin
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Omar Touzani
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Keith W. Muir
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - Kennedy R. Lees
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
| | - I. Mhairi Macrae
- From the 7TMRI Facility (C.L., C.M., L.G., J.M., I.M.M.), Division of Clinical Neuroscience, University of Glasgow, Glasgow, Scotland; Centre Cyceron (C.L., O.T.), CNRS UMR 6185, University of Caen, Caen, France; the Robertson Centre for Biostatistics (C.J.W.); Division of Clinical Neurosciences (K.W.M.), Institute of Neurological Sciences, Southern General Hospital; and the Division of Cardiovascular and Medical Sciences (K.R.L.), Western Infirmary, University of Glasgow, Glasgow, Scotland
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