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Zhu Y, Tran Q, Wang Y, Badawi RD, Cherry SR, Qi J, Abbaszadeh S, Wang G. Optimization-derived blood input function using a kernel method and its evaluation with total-body PET for brain parametric imaging. Neuroimage 2024; 293:120611. [PMID: 38643890 PMCID: PMC11251003 DOI: 10.1016/j.neuroimage.2024.120611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/23/2024] Open
Abstract
Dynamic PET allows quantification of physiological parameters through tracer kinetic modeling. For dynamic imaging of brain or head and neck cancer on conventional PET scanners with a short axial field of view, the image-derived input function (ID-IF) from intracranial blood vessels such as the carotid artery (CA) suffers from severe partial volume effects. Alternatively, optimization-derived input function (OD-IF) by the simultaneous estimation (SIME) method does not rely on an ID-IF but derives the input function directly from the data. However, the optimization problem is often highly ill-posed. We proposed a new method that combines the ideas of OD-IF and ID-IF together through a kernel framework. While evaluation of such a method is challenging in human subjects, we used the uEXPLORER total-body PET system that covers major blood pools to provide a reference for validation. METHODS The conventional SIME approach estimates an input function using a joint estimation together with kinetic parameters by fitting time activity curves from multiple regions of interests (ROIs). The input function is commonly parameterized with a highly nonlinear model which is difficult to estimate. The proposed kernel SIME method exploits the CA ID-IF as a priori information via a kernel representation to stabilize the SIME approach. The unknown parameters are linear and thus easier to estimate. The proposed method was evaluated using 18F-fluorodeoxyglucose studies with both computer simulations and 20 human-subject scans acquired on the uEXPLORER scanner. The effect of the number of ROIs on kernel SIME was also explored. RESULTS The estimated OD-IF by kernel SIME showed a good match with the reference input function and provided more accurate estimation of kinetic parameters for both simulation and human-subject data. The kernel SIME led to the highest correlation coefficient (R = 0.97) and the lowest mean absolute error (MAE = 10.5 %) compared to using the CA ID-IF (R = 0.86, MAE = 108.2 %) and conventional SIME (R = 0.57, MAE = 78.7 %) in the human-subject evaluation. Adding more ROIs improved the overall performance of the kernel SIME method. CONCLUSION The proposed kernel SIME method shows promise to provide an accurate estimation of the blood input function and kinetic parameters for brain PET parametric imaging.
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Affiliation(s)
- Yansong Zhu
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA.
| | - Quyen Tran
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Yiran Wang
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA; Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616, USA
| | - Ramsey D Badawi
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA; Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616, USA
| | - Simon R Cherry
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA; Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616, USA
| | - Jinyi Qi
- Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616, USA
| | - Shiva Abbaszadeh
- Department of Electrical and Computer Engineering, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
| | - Guobao Wang
- Department of Radiology, University of California Davis Medical Center, Sacramento, CA 95817, USA
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Syed AU, Liang C, Patel KK, Mondal R, Kamalia VM, Moran TR, Ahmed ST, Mukherjee J. Comparison of Monoamine Oxidase-A, Aβ Plaques, Tau, and Translocator Protein Levels in Postmortem Human Alzheimer's Disease Brain. Int J Mol Sci 2023; 24:10808. [PMID: 37445985 PMCID: PMC10341404 DOI: 10.3390/ijms241310808] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 06/19/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
Increased monoamine oxidase-A (MAO-A) activity in Alzheimer's disease (AD) may be detrimental to the point of neurodegeneration. To assess MAO-A activity in AD, we compared four biomarkers, Aβ plaques, tau, translocator protein (TSPO), and MAO-A in postmortem AD. Radiotracers were [18F]FAZIN3 for MAO-A, [18F]flotaza and [125I]IBETA for Aβ plaques, [124/125I]IPPI for tau, and [18F]FEPPA for TSPO imaging. Brain sections of the anterior cingulate (AC; gray matter GM) and corpus callosum (CC; white matter WM) from cognitively normal control (CN, n = 6) and AD (n = 6) subjects were imaged using autoradiography and immunostaining. Using competition with clorgyline and (R)-deprenyl, the binding of [18F]FAZIN3 was confirmed to be selective to MAO-A levels in the AD brain sections. Increases in MAO-A, Aβ plaque, tau, and TSPO activity were found in the AD brains compared to the control brains. The [18F]FAZIN3 ratio in AD GM versus CN GM was 2.80, suggesting a 180% increase in MAO-A activity. Using GM-to-WM ratios of AD versus CN, a >50% increase in MAO-A activity was observed (AD/CN = 1.58). Linear positive correlations of [18F]FAZIN3 with [18F]flotaza, [125I]IBETA, and [125I]IPPI were measured and suggested an increase in MAO-A activity with increases in Aβ plaques and tau activity. Our results support the finding that MAO-A activity is elevated in the anterior cingulate cortex in AD and thus may provide a new biomarker for AD in this brain region.
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Affiliation(s)
| | | | | | | | | | | | | | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA
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van der Weijden CWJ, Mossel P, Bartels AL, Dierckx RAJO, Luurtsema G, Lammertsma AA, Willemsen ATM, de Vries EFJ. Non-invasive kinetic modelling approaches for quantitative analysis of brain PET studies. Eur J Nucl Med Mol Imaging 2023; 50:1636-1650. [PMID: 36651951 PMCID: PMC10119247 DOI: 10.1007/s00259-022-06057-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 11/21/2022] [Indexed: 01/19/2023]
Abstract
Pharmacokinetic modelling with arterial sampling is the gold standard for analysing dynamic PET data of the brain. However, the invasive character of arterial sampling prevents its widespread clinical application. Several methods have been developed to avoid arterial sampling, in particular reference region methods. Unfortunately, for some tracers or diseases, no suitable reference region can be defined. For these cases, other potentially non-invasive approaches have been proposed: (1) a population based input function (PBIF), (2) an image derived input function (IDIF), or (3) simultaneous estimation of the input function (SIME). This systematic review aims to assess the correspondence of these non-invasive methods with the gold standard. Studies comparing non-invasive pharmacokinetic modelling methods with the current gold standard methods using an input function derived from arterial blood samples were retrieved from PubMed/MEDLINE (until December 2021). Correlation measurements were extracted from the studies. The search yielded 30 studies that correlated outcome parameters (VT, DVR, or BPND for reversible tracers; Ki or CMRglu for irreversible tracers) from a potentially non-invasive method with those obtained from modelling using an arterial input function. Some studies provided similar results for PBIF, IDIF, and SIME-based methods as for modelling with an arterial input function (R2 = 0.59-1.00, R2 = 0.71-1.00, R2 = 0.56-0.96, respectively), if the non-invasive input curve was calibrated with arterial blood samples. Even when the non-invasive input curve was calibrated with venous blood samples or when no calibration was applied, moderate to good correlations were reported, especially for the IDIF and SIME (R2 = 0.71-1.00 and R2 = 0.36-0.96, respectively). Overall, this systematic review illustrates that non-invasive methods to generate an input function are still in their infancy. Yet, IDIF and SIME performed well, not only with arterial blood calibration, but also with venous or no blood calibration, especially for some tracers without plasma metabolites, which would potentially make these methods better suited for clinical application. However, these methods should still be properly validated for each individual tracer and application before implementation.
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Affiliation(s)
- Chris W J van der Weijden
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands.,Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen, The Netherlands
| | - Pascalle Mossel
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Anna L Bartels
- Department of Neurology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen, The Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Adriaan A Lammertsma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Antoon T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Erik F J de Vries
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands.
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Mukherjee J, Ladwa RM, Liang C, Syed AU. Elevated Monoamine Oxidase-A in Anterior Cingulate of Post-Mortem Human Parkinson's Disease: A Potential Surrogate Biomarker for Lewy Bodies? Cells 2022; 11:cells11244000. [PMID: 36552764 PMCID: PMC9777299 DOI: 10.3390/cells11244000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 11/27/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Lewy bodies (LB) play a neuropathological role in Parkinson's disease (PD). Our goal was to evaluate LB using anti-ubiquitin immunohistochemistry (UIHC) and find correlations with monoamine oxidase-A (MAO-A) using imaging agent, [18F]FAZIN3. Human post-mortem anterior cingulate (AC) and corpus callosum (CC) from control subjects (CN), n = 6; age 81-90 LB = 0 and PD, n = 6, age 77-89, LB = III-IV were sectioned (10 μm slices). Brain slices were immunostained with anti-ubiquitin for LB (UIHC) and analyzed using QuPath for percent anti-ubiquitin per unit area (μm2). Adjacent brain slices were incubated with [18F]FAZIN3 and cortical layers I-III, IV-VI and CC (white matter) regions were quantified for the binding of [18F]FAZIN3. UIHC was correlated with [18F]FAZIN3 binding. All PD brains were positively UIHC stained and confirmed presence of LB. Outer cortical layers (I-III) of PD AC had 21% UIHC while inner layers (IV-VI) had >75% UIHC. In the CN brains LB were absent (<1% UIHC). Increased [18F]FAZIN3 binding to MAO-A in AC was observed in all PD subjects. [18F]FAZIN3 ratio in PD was AC/CC = 3.57 while in CN subjects it was AC/CC = 2.24. Increases in UIHC μm2 correlated with [18F]FAZIN3 binding to MAO-A in DLU/mm2. Increased [18F]FAZIN3 binding to MAO-A in PD is a potential novel "hot spot" PET imaging approach.
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Liu W, Tian L, Wu L, Chen H, Wang N, Liu X, Zhao C, Wu Z, Jiang X, Wu Q, Xu Z, Liu W, Zhao Q. Discovery of novel β-carboline-1,2,3-triazole hybrids as AChE/GSK-3β dual inhibitors for Alzheimer's disease treatment. Bioorg Chem 2022; 129:106168. [DOI: 10.1016/j.bioorg.2022.106168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/02/2022]
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Shegani A, Kealey S, Luzi F, Basagni F, Machado JDM, Ekici SD, Ferocino A, Gee AD, Bongarzone S. Radiosynthesis, Preclinical, and Clinical Positron Emission Tomography Studies of Carbon-11 Labeled Endogenous and Natural Exogenous Compounds. Chem Rev 2022; 123:105-229. [PMID: 36399832 PMCID: PMC9837829 DOI: 10.1021/acs.chemrev.2c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The presence of positron emission tomography (PET) centers at most major hospitals worldwide, along with the improvement of PET scanner sensitivity and the introduction of total body PET systems, has increased the interest in the PET tracer development using the short-lived radionuclides carbon-11. In the last few decades, methodological improvements and fully automated modules have allowed the development of carbon-11 tracers for clinical use. Radiolabeling natural compounds with carbon-11 by substituting one of the backbone carbons with the radionuclide has provided important information on the biochemistry of the authentic compounds and increased the understanding of their in vivo behavior in healthy and diseased states. The number of endogenous and natural compounds essential for human life is staggering, ranging from simple alcohols to vitamins and peptides. This review collates all the carbon-11 radiolabeled endogenous and natural exogenous compounds synthesised to date, including essential information on their radiochemistry methodologies and preclinical and clinical studies in healthy subjects.
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Affiliation(s)
- Antonio Shegani
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Steven Kealey
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Federico Luzi
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Filippo Basagni
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Joana do Mar Machado
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Sevban Doğan Ekici
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Alessandra Ferocino
- Institute
of Organic Synthesis and Photoreactivity, Italian National Research Council, via Piero Gobetti 101, 40129 Bologna, Italy
| | - Antony D. Gee
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,A.G.: email,
| | - Salvatore Bongarzone
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,S.B.:
email,
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Laurell GL, Plavén-Sigray P, Svarer C, Ogden RT, Knudsen GM, Schain M. Designing drug occupancy studies with PET neuroimaging: Sample size, occupancy ranges and analytical methods. Neuroimage 2022; 263:119620. [PMID: 36087903 DOI: 10.1016/j.neuroimage.2022.119620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/18/2022] [Accepted: 09/06/2022] [Indexed: 11/27/2022] Open
Abstract
Molecular neuroimaging is today considered essential for evaluation of novel CNS drugs; it is used to quantify blood-brain barrier permeability, verify interaction with key target and determine the drug dose resulting in 50% occupancy, IC50. In spite of this, there has been limited data available to inform on how to optimize study designs. Through simulations, we here evaluate how IC50 estimation is affected by the (i) range of drug doses administered, (ii) number of subjects included, and (iii) level of noise in the plasma drug concentration measurements. Receptor occupancy is determined from PET distribution volumes using two different methods: the Lassen plot and Likelihood estimation of occupancy (LEO). We also introduce and evaluate a new likelihood-based estimator for direct estimation of IC50 from PET distribution volumes. For estimation of IC50, we find very limited added benefit in scanning individuals who are given drug doses corresponding to less than 40% receptor occupancy. In the range of typical PET sample sizes (5-20 subjects) each extra individual clearly reduces the error of the IC50 estimate. In all simulations, likelihood-based methods gave more precise IC50 estimates than the Lassen plot; four times the number of subjects were required for the Lassen plot to reach the same IC50 precision as LEO.
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Affiliation(s)
- Gjertrud Louise Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark
| | - R Todd Ogden
- Department of Biostatistics, Columbia University, New York, NY, United States; Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, NY, United States
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, 6-8 Inge Lehmanns Vej, Rigshospitalet, Copenhagen DK-2100, Denmark; Antaros Medical AB, Mölndal, Sweden
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Bartlett EA, Ogden RT, Mann JJ, Zanderigo F. Source-to-Target Automatic Rotating Estimation (STARE) - a publicly-available, blood-free quantification approach for PET tracers with irreversible kinetics: Theoretical framework and validation for [ 18F]FDG. Neuroimage 2022; 249:118901. [PMID: 35026425 PMCID: PMC8969778 DOI: 10.1016/j.neuroimage.2022.118901] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/16/2021] [Accepted: 01/09/2022] [Indexed: 10/30/2022] Open
Abstract
INTRODUCTION Full quantification of positron emission tomography (PET) data requires an input function. This generally means arterial blood sampling, which is invasive, labor-intensive and burdensome. There is no current, standardized method to fully quantify PET radiotracers with irreversible kinetics in the absence of blood data. Here, we present Source-to-Target Automatic Rotating Estimation (STARE), a novel, data-driven approach to quantify the net influx rate (Ki) of irreversible PET radiotracers, that requires only individual-level PET data and no blood data. We validate STARE with human [18F]FDG PET scans and assess its performance using simulations. METHODS STARE builds upon a source-to-target tissue model, where the tracer time activity curves (TACs) in multiple "target" regions are expressed at once as a function of a "source" region, based on the two-tissue irreversible compartment model, and separates target region Ki from source Ki by fitting the source-to-target model across all target regions simultaneously. To ensure identifiability, data-driven, subject-specific anchoring is used in the STARE minimization, which takes advantage of the PET signal in a vasculature cluster in the field of view (FOV) that is automatically extracted and partial volume-corrected. To avoid the need for any a priori determination of a single source region, each of the considered regions acts in turn as the source, and a final Ki is estimated in each region by averaging the estimates obtained in each source rotation. RESULTS In a large dataset of human [18F]FDG scans (N=69), STARE Ki estimates were correlated with corresponding arterial blood-based Ki estimates (r=0.80), with an overall regression slope of 0.88, and were precisely estimated, as assessed by comparing STARE Ki estimates across several runs of the algorithm (coefficient of variation across runs=6.74 ± 2.48%). In simulations, STARE Ki estimates were largely robust to factors that influence the individualized anchoring used within its algorithm. CONCLUSION Through simulations and application to [18F]FDG PET data, feasibility is demonstrated for STARE blood-free, data-driven quantification of Ki. Future work will include applying STARE to PET data obtained with a portable PET camera and to other irreversible radiotracers.
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Affiliation(s)
- Elizabeth A Bartlett
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, USA; Department of Psychiatry, Columbia University Medical Center, New York, USA.
| | - R Todd Ogden
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, USA; Department of Psychiatry, Columbia University Medical Center, New York, USA; Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, USA
| | - J John Mann
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, USA; Department of Psychiatry, Columbia University Medical Center, New York, USA; Department of Radiology, Columbia University Medical Center, New York, USA
| | - Francesca Zanderigo
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, USA; Department of Psychiatry, Columbia University Medical Center, New York, USA
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Duarte P, Cuadrado A, León R. Monoamine Oxidase Inhibitors: From Classic to New Clinical Approaches. Handb Exp Pharmacol 2021; 264:229-259. [PMID: 32852645 DOI: 10.1007/164_2020_384] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Monoamine oxidases (MAOs) are involved in the oxidative deamination of different amines and neurotransmitters. This pointed them as potential targets for several disorders and along the last 70 years a wide variety of MAO inhibitors have been developed as successful drugs for the treatment of complex diseases, being the first drugs approved for depression in the late 1950s. The discovery of two MAO isozymes (MAO-A and B) with different substrate selectivity and tissue expression patterns led to novel therapeutic approaches and to the development of new classes of inhibitors, such as selective irreversible and reversible MAO-B inhibitors and reversible MAO-A inhibitors. Significantly, MAO-B inhibitors constitute a widely studied group of compounds, some of them approved for the treatment of Parkinson's disease. Further applications are under development for the treatment of Alzheimer's disease, amyotrophic lateral sclerosis, and cardiovascular diseases, among others. This review summarizes the most important aspects regarding the development and clinical use of MAO inhibitors, going through mechanistic and structural details, new indications, and future perspectives. Monoamine oxidases (MAOs) catalyze the oxidative deamination of different amines and neurotransmitters. The two different isozymes, MAO-A and MAO-B, are located at the outer mitochondrial membrane in different tissues. The enzymatic reaction involves formation of the corresponding aldehyde and releasing hydrogen peroxide (H2O2) and ammonia or a substituted amine depending on the substrate. MAO's role in neurotransmitter metabolism made them targets for major depression and Parkinson's disease, among other neurodegenerative diseases. Currently, these compounds are being studied for other diseases such as cardiovascular ones.
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Affiliation(s)
- Pablo Duarte
- Instituto Teófilo Hernando y Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
- Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, Madrid, Spain
| | - Antonio Cuadrado
- Departmento de Bioquímica, Facultad de Medicina, Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Investigación Sanitaria La Paz (IdiPaz), Instituto de Investigaciones Biomédicas 'Alberto Sols' UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael León
- Instituto Teófilo Hernando y Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.
- Instituto de Investigación Sanitaria, Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, Madrid, Spain.
- Instituto de Química Médica, Consejo Superior de Investigaciones CientÚficas (IQM-CSIC), Madrid, Spain.
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Papanastasiou G, Rodrigues MA, Wang C, Heurling K, Lucatelli C, Salman RAS, Wardlaw JM, van Beek EJR, Thompson G. Pharmacokinetic modelling for the simultaneous assessment of perfusion and 18F-flutemetamol uptake in cerebral amyloid angiopathy using a reduced PET-MR acquisition time: Proof of concept. Neuroimage 2020; 225:117482. [PMID: 33157265 DOI: 10.1016/j.neuroimage.2020.117482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 09/24/2020] [Accepted: 10/19/2020] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease associated with perivascular β-amyloid deposition. CAA is also associated with strokes due to lobar intracerebral haemorrhage (ICH). 18F-flutemetamol amyloid ligand PET may improve the early detection of CAA. We performed pharmacokinetic modelling using both full (0-30, 90-120 min) and reduced (30 min) 18F-flutemetamol PET-MR acquisitions, to investigate regional cerebral perfusion and amyloid deposition in ICH patients. METHODS Dynamic18F-flutemetamol PET-MR was performed in a pilot cohort of sixteen ICH participants; eight lobar ICH cases with probable CAA and eight deep ICH patients. A model-based input function (mIF) method was developed for compartmental modelling. mIF 1-tissue (1-TC) and 2-tissue (2-TC) compartmental modelling, reference tissue models and standardized uptake value ratios were assessed in the setting of probable CAA detection. RESULTS The mIF 1-TC model detected perfusion deficits and 18F-flutemetamol uptake in cases with probable CAA versus deep ICH patients, in both full and reduced PET acquisition time (all P < 0.05). In the reduced PET acquisition, mIF 1-TC modelling reached the highest sensitivity and specificity in detecting perfusion deficits (0.87, 0.77) and 18F-flutemetamol uptake (0.83, 0.71) in cases with probable CAA. Overall, 52 and 48 out of the 64 brain areas with 18F-flutemetamol-determined amyloid deposition showed reduced perfusion for 1-TC and 2-TC models, respectively. CONCLUSION Pharmacokinetic (1-TC) modelling using a 30 min PET-MR time frame detected impaired haemodynamics and increased amyloid load in probable CAA. Perfusion deficits and amyloid burden co-existed within cases with CAA, demonstrating a distinct imaging pattern which may have merit in elucidating the pathophysiological process of CAA.
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Affiliation(s)
- Giorgos Papanastasiou
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
| | - Mark A Rodrigues
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Chengjia Wang
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | | | - Christophe Lucatelli
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | | | - Joanna M Wardlaw
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK; Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Edwin J R van Beek
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Gerard Thompson
- Edinburgh Imaging Facility, Queen's Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK; Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
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Sex and the serotonergic underpinnings of depression and migraine. HANDBOOK OF CLINICAL NEUROLOGY 2020; 175:117-140. [PMID: 33008520 DOI: 10.1016/b978-0-444-64123-6.00009-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most psychiatric disorders demonstrate sex differences in their prevalence and symptomatology, and in their response to treatment. These differences are particularly pronounced in mood disorders. Differences in sex hormone levels are among the most overt distinctions between males and females and are thus an intuitive underpinning for these clinical observations. In fact, treatment with estrogen and testosterone was shown to exert antidepressant effects, which underscores this link. Changes to monoaminergic signaling in general, and serotonergic transmission in particular, are understood as central components of depressive pathophysiology. Thus, modulation of the serotonin system may serve as a mechanism via which sex hormones exert their clinical effects in mental health disorders. Over the past 20 years, various experimental approaches have been applied to identify modes of influence of sex and sex hormones on the serotonin system. This chapter provides an overview of different molecular components of the serotonin system, followed by a review of studies performed in animals and in humans with the purpose of elucidating sex hormone effects. Particular emphasis will be placed on studies performed with positron emission tomography, a method that allows for human in vivo molecular imaging and, therefore, assessment of effects in a clinically representative context. The studies addressed in this chapter provide a wealth of information on the interaction between sex, sex hormones, and serotonin in the brain. In general, they offer evidence for the concept that the influence of sex hormones on various components of the serotonin system may serve as an underpinning for the clinical effects these hormones demonstrate.
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