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Willekens SMA, Morini F, Mediavilla T, Nilsson E, Orädd G, Hahn M, Chotiwan N, Visa M, Berggren PO, Ilegems E, Överby AK, Ahlgren U, Marcellino D. An MR-based brain template and atlas for optical projection tomography and light sheet fluorescence microscopy in neuroscience. Front Neurosci 2024; 18:1328815. [PMID: 38601090 PMCID: PMC11004350 DOI: 10.3389/fnins.2024.1328815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 03/11/2024] [Indexed: 04/12/2024] Open
Abstract
Introduction Optical Projection Tomography (OPT) and light sheet fluorescence microscopy (LSFM) are high resolution optical imaging techniques, ideally suited for ex vivo 3D whole mouse brain imaging. Although they exhibit high specificity for their targets, the anatomical detail provided by tissue autofluorescence remains limited. Methods T1-weighted images were acquired from 19 BABB or DBE cleared brains to create an MR template using serial longitudinal registration. Afterwards, fluorescent OPT and LSFM images were coregistered/normalized to the MR template to create fusion images. Results Volumetric calculations revealed a significant difference between BABB and DBE cleared brains, leading to develop two optimized templates, with associated tissue priors and brain atlas, for BABB (OCUM) and DBE (iOCUM). By creating fusion images, we identified virus infected brain regions, mapped dopamine transporter and translocator protein expression, and traced innervation from the eye along the optic tract to the thalamus and superior colliculus using cholera toxin B. Fusion images allowed for precise anatomical identification of fluorescent signal in the detailed anatomical context provided by MR. Discussion The possibility to anatomically map fluorescent signals on magnetic resonance (MR) images, widely used in clinical and preclinical neuroscience, would greatly benefit applications of optical imaging of mouse brain. These specific MR templates for cleared brains enable a broad range of neuroscientific applications integrating 3D optical brain imaging.
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Affiliation(s)
- Stefanie M. A. Willekens
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Federico Morini
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Tomas Mediavilla
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Emma Nilsson
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Greger Orädd
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Max Hahn
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Nunya Chotiwan
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Montse Visa
- The Rolf Luft Research Centre for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Centre for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Erwin Ilegems
- The Rolf Luft Research Centre for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Anna K. Överby
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Ulf Ahlgren
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
| | - Daniel Marcellino
- Department of Medical and Translational Biology, Umeå University, Umeå, Sweden
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Chotiwan N, Rosendal E, Willekens SMA, Schexnaydre E, Nilsson E, Lindqvist R, Hahn M, Mihai IS, Morini F, Zhang J, Ebel GD, Carlson LA, Henriksson J, Ahlgren U, Marcellino D, Överby AK. Type I interferon shapes brain distribution and tropism of tick-borne flavivirus. Nat Commun 2023; 14:2007. [PMID: 37037810 PMCID: PMC10086010 DOI: 10.1038/s41467-023-37698-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 03/28/2023] [Indexed: 04/12/2023] Open
Abstract
Viral tropism within the brain and the role(s) of vertebrate immune response to neurotropic flaviviruses infection is largely understudied. We combine multimodal imaging (cm-nm scale) with single nuclei RNA-sequencing to study Langat virus in wildtype and interferon alpha/beta receptor knockout (Ifnar-/-) mice to visualize viral pathogenesis and define molecular mechanisms. Whole brain viral infection is imaged by Optical Projection Tomography coregistered to ex vivo MRI. Infection is limited to grey matter of sensory systems in wildtype mice, but extends into white matter, meninges and choroid plexus in Ifnar-/- mice. Cells in wildtype display strong type I and II IFN responses, likely due to Ifnb expressing astrocytes, infiltration of macrophages and Ifng-expressing CD8+ NK cells, whereas in Ifnar-/-, the absence of this response contributes to a shift in cellular tropism towards non-activated resident microglia. Multimodal imaging-transcriptomics exemplifies a powerful way to characterize mechanisms of viral pathogenesis and tropism.
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Affiliation(s)
- Nunya Chotiwan
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden.
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden.
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samut Prakan, 10540, Thailand.
| | - Ebba Rosendal
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
| | - Stefanie M A Willekens
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, 90187, Umeå, Sweden
| | - Erin Schexnaydre
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, 90187, Umeå, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
- Umeå Centre for Microbial Research, Umeå University, 90187, Umeå, Sweden
| | - Emma Nilsson
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
| | - Richard Lindqvist
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
| | - Max Hahn
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, 90187, Umeå, Sweden
| | - Ionut Sebastian Mihai
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Department of Department of Molecular biology, Umeå University, 90187, Umeå, Sweden
- Företagsforskarskolan, Umeå University, 90187, Umeå, Sweden
| | - Federico Morini
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, 90187, Umeå, Sweden
| | - Jianguo Zhang
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, 90187, Umeå, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
- Umeå Centre for Microbial Research, Umeå University, 90187, Umeå, Sweden
| | - Gregory D Ebel
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Lars-Anders Carlson
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, 90187, Umeå, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
- Umeå Centre for Microbial Research, Umeå University, 90187, Umeå, Sweden
| | - Johan Henriksson
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden
- Umeå Centre for Microbial Research, Umeå University, 90187, Umeå, Sweden
- Department of Department of Molecular biology, Umeå University, 90187, Umeå, Sweden
| | - Ulf Ahlgren
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, 90187, Umeå, Sweden
| | - Daniel Marcellino
- Department of Integrative Medical Biology, Umeå University, 90187, Umeå, Sweden
| | - Anna K Överby
- Department of Clinical Microbiology, Umeå University, 90185, Umeå, Sweden.
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187, Umeå, Sweden.
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Gotthardt M, Joosten L, Jansen TJP, Brom M, Boss M, Willekens SMA. From Mice to Humans: The Exocrine Pancreas Does Not Matter in Human GLP-1 Receptor Imaging. J Nucl Med 2021; 62:745. [PMID: 33608428 DOI: 10.2967/jnumed.120.259184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Martin Gotthardt
- Radboud University Medical Center Nijmegen, The Netherlands E-mail:
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Alanentalo T, Hahn M, Willekens SMA, Ahlgren U. Mesoscopic Optical Imaging of the Pancreas-Revisiting Pancreatic Anatomy and Pathophysiology. Front Endocrinol (Lausanne) 2021; 12:633063. [PMID: 33746904 PMCID: PMC7969990 DOI: 10.3389/fendo.2021.633063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/07/2021] [Indexed: 11/24/2022] Open
Abstract
The exocrine-endocrine multipart organization of the pancreas makes it an exceedingly challenging organ to analyze, quantitatively and spatially. Both in rodents and humans, estimates of the pancreatic cellular composition, including beta-cell mass, has been largely relying on the extrapolation of 2D stereological data originating from limited sample volumes. Alternatively, they have been obtained by low resolution non-invasive imaging techniques providing little detail regarding the anatomical organization of the pancreas and its cellular and/or molecular make up. In this mini-review, the state of the art and the future potential of currently existing and emerging high-resolution optical imaging techniques working in the mm-cm range with μm resolution, here referred to as mesoscopic imaging approaches, will be discussed regarding their contribution toward a better understanding of pancreatic anatomy both in normal conditions and in the diabetic setting. In particular, optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) imaging of the pancreas and their associated tissue processing and computational analysis protocols will be discussed in the light of their current capabilities and future potential to obtain more detailed 3D-spatial, quantitative, and molecular information of the pancreas.
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Rezaei A, Schramm G, Willekens SMA, Delso G, Van Laere K, Nuyts J. A Quantitative Evaluation of Joint Activity and Attenuation Reconstruction in TOF PET/MR Brain Imaging. J Nucl Med 2019; 60:1649-1655. [PMID: 30979823 DOI: 10.2967/jnumed.118.220871] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 04/04/2019] [Indexed: 11/16/2022] Open
Abstract
Time-of-flight (TOF) PET data provide an effective means for attenuation correction (AC) when no (or incomplete or inaccurate) attenuation information is available. Since MR scanners provide little information on photon attenuation of different tissue types, AC in hybrid PET/MR scanners has always been challenging. In this contribution, we aim at validating the activity reconstructions of the maximum-likelihood ordered-subsets activity and attenuation (OSAA) reconstruction algorithm on a patient brain data set. We present a quantitative comparison of joint reconstructions with the current clinical gold standard-ordered-subsets expectation maximization-using CT-based AC in PET/CT, as well as the current state of the art in PET/MR, that is, zero time echo (ZTE)-based AC. Methods: The TOF PET emission data were initially used in a preprocessing stage to estimate crystal maps of efficiencies, timing offsets, and timing resolutions. Applying these additional corrections during reconstructions, OSAA, ZTE-based, and the vendor-provided atlas-based AC techniques were analyzed and compared with CT-based AC. In our initial study, we used the CT-based estimate of the expected scatter and later used the ZTE-based and OSAA attenuation estimates to compute the expected scatter contribution of the data during reconstructions. In all reconstructions, a maximum-likelihood scaling of the single-scatter simulation estimate to the emission data was used for scatter correction. The reconstruction results were analyzed in the 86 segmented regions of interest of the Hammers atlas. Results: Our quantitative analysis showed that, in practice, a tracer activity difference of +0.5% (±2.1%) and +0.1% (±2.3%) could be expected for the state-of-the-art ZTE-based and OSAA AC methods, respectively, in PET/MR compared with the clinical gold standard in PET/CT. Conclusion: Joint activity and attenuation estimation methods can provide an effective solution to the challenging AC problem for brain studies in hybrid TOF PET/MR scanners. With an accurate TOF-based (timing offsets and timing resolutions) calibration, and similar to the results of the state-of-the-art method in PET/MR, regional errors of joint TOF PET reconstructions are within a few percentage points.
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Affiliation(s)
- Ahmadreza Rezaei
- KU Leuven - University of Leuven, Department of Imaging and Pathology, Division of Nuclear Medicine & Molecular Imaging (NMMI), Medical Imaging Research Center (MIRC), B-3000, Leuven, Belgium; and
| | - Georg Schramm
- KU Leuven - University of Leuven, Department of Imaging and Pathology, Division of Nuclear Medicine & Molecular Imaging (NMMI), Medical Imaging Research Center (MIRC), B-3000, Leuven, Belgium; and
| | - Stefanie M A Willekens
- KU Leuven - University of Leuven, Department of Imaging and Pathology, Division of Nuclear Medicine & Molecular Imaging (NMMI), Medical Imaging Research Center (MIRC), B-3000, Leuven, Belgium; and
| | - Gaspar Delso
- MR Applications and Workflow, GE Healthcare, Waukesha, Wisconsin
| | - Koen Van Laere
- KU Leuven - University of Leuven, Department of Imaging and Pathology, Division of Nuclear Medicine & Molecular Imaging (NMMI), Medical Imaging Research Center (MIRC), B-3000, Leuven, Belgium; and
| | - Johan Nuyts
- KU Leuven - University of Leuven, Department of Imaging and Pathology, Division of Nuclear Medicine & Molecular Imaging (NMMI), Medical Imaging Research Center (MIRC), B-3000, Leuven, Belgium; and
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Willekens SMA, Joosten L, Boerman OC, Brom M, Gotthardt M. Characterization of 111In-labeled Glucose-Dependent Insulinotropic Polypeptide as a Radiotracer for Neuroendocrine Tumors. Sci Rep 2018; 8:2948. [PMID: 29440684 PMCID: PMC5811606 DOI: 10.1038/s41598-018-21259-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/31/2018] [Indexed: 12/04/2022] Open
Abstract
Somatostatin receptor targeting is considered the standard nuclear medicine technique for visualization of neuroendocrine tumors (NET). Since not all NETs over-express somatostatin receptors, the search for novel targets, visualizing these NETs, is ongoing. Many NETs, expressing low somatostatin receptor levels, express glucose-dependent insulinotropic polypeptide (GIP) receptors (GIPR). Here, we evaluated the performance of [Lys37(DTPA)]N-acetyl-GIP1-42, a newly synthesized GIP analogue to investigate whether NET imaging via GIPR targeting is feasible. Therefore, [Lys37(DTPA)]N-acetyl-GIP1-42 was radiolabeled with 111In with specific activity up to 1.2 TBq/µmol and both in vitro and in vivo receptor targeting properties were examined. In vitro, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 showed receptor-mediated binding to BHK-GIPR positive cells, NES2Y cells and isolated islets. In vivo, both NES2Y and GIPR-transfected BHK tumors were visualized on SPECT/CT. Furthermore, co-administration of an excess unlabeled GIP1-42 lowered tracer uptake from 0.7 ± 0.2%ID/g to 0.6 ± 0.01%ID/g (p = 0.78) in NES2Y tumors and significantly lowered tracer uptake from 3.3 ± 0.8 to 0.8 ± 0.2%ID/g (p = 0.0001) in GIPR-transfected BHK tumors. In conclusion, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 shows receptor-mediated binding in various models. Furthermore, both GIPR-transfected BHK tumors and NES2Y tumors were visible on SPECT/CT using this tracer. Therefore, [Lys37(111In-DTPA)]N-acetyl-GIP1-42 SPECT seems promising for visualization of somatostatin receptor negative NETs.
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Affiliation(s)
- Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands. .,Division of Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospitals and KU Leuven, Leuven, Belgium.
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
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Willekens SMA, Joosten L, Boerman OC, Balhuizen A, Eizirik DL, Gotthardt M, Brom M. Strain Differences Determine the Suitability of Animal Models for Noninvasive In Vivo Beta Cell Mass Determination with Radiolabeled Exendin. Mol Imaging Biol 2017; 18:705-14. [PMID: 26886298 PMCID: PMC5010585 DOI: 10.1007/s11307-016-0936-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Purpose Noninvasive beta cell mass (BCM) quantification is a crucial tool to understand diabetes development and progression. [111In]exendin is a promising agent for in vivo beta cell imaging, but tracer testing has been hampered by the lack of well-defined rodent models. Procedures Biodistribution and pancreatic uptake of [111In]exendin were compared in rats and mice. In selected models, the amount of [111In]exendin accumulation in the pancreas and other organs was determined using a model of alloxan-induced beta cell loss. GLP-1R expression levels were analyzed by RT-PCR and immunohistochemistry. Results Namely Brown Norway rats showed beta-cell-specific tracer accumulation and favorable pancreas-to-background ratios for noninvasive BCM determination. Mice displayed receptor-mediated [111In]exendin uptake in endocrine and exocrine pancreas, in spite of very low GLP-1R expression in exocrine tissue. Conclusions Rats display better characteristics for in vivo BCM determination than mice and are suggested as a more adequate model for humans. Electronic supplementary material The online version of this article (doi:10.1007/s11307-016-0936-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands.
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands
| | - Alexander Balhuizen
- ULB Center for Diabetes Research, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands
| | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands
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Eter WA, Van der Kroon I, Andralojc K, Buitinga M, Willekens SMA, Frielink C, Bos D, Joosten L, Boerman OC, Brom M, Gotthardt M. Non-invasive in vivo determination of viable islet graft volume by 111In-exendin-3. Sci Rep 2017; 7:7232. [PMID: 28775287 PMCID: PMC5543140 DOI: 10.1038/s41598-017-07815-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 06/30/2017] [Indexed: 01/20/2023] Open
Abstract
Pancreatic islet transplantation is a promising therapy for patients with type 1 diabetes. However, the duration of long-term graft survival is limited due to inflammatory as well as non-inflammatory processes and routine clinical tests are not suitable to monitor islet survival. 111In-exendin-SPECT (single photon emission computed tomography) is a promising method to non-invasively image islets after transplantation and has the potential to help improve the clinical outcome. Whether 111In-exendin-SPECT allows detecting small differences in beta-cell mass (BCM) and measuring the actual volume of islets that were successfully engrafted has yet to be demonstrated. Here, we evaluated the performance of 111In-exendin-SPECT using an intramuscular islet transplantation model in C3H mice. In vivo imaging of animals transplanted with 50, 100, 200, 400 and 800 islets revealed an excellent linear correlation between SPECT quantification of 111In-exendin uptake and insulin-positive area of islet transplants, demonstrating that 111In-exendin-SPECT specifically and accurately measures BCM. The high sensitivity of the method allowed measuring small differences in graft volumes, including grafts that contained less than 50 islets. The presented method is reliable, convenient and holds great potential for non-invasive monitoring of BCM after islet transplantation in humans.
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Affiliation(s)
- Wael A Eter
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Inge Van der Kroon
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Karolina Andralojc
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Mijke Buitinga
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Cathelijne Frielink
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Desiree Bos
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
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Willekens SMA, van der Kroon I, Bos D, Joosten L, Frielink C, Boerman OC, Brom M, Gotthardt M. Quantitative and longitudinal imaging of intramuscular transplanted islets of Langerhans with SPECT using [ 123 I]IBZM. Diabetes Obes Metab 2017; 19:604-608. [PMID: 27987245 DOI: 10.1111/dom.12857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/30/2016] [Accepted: 12/12/2016] [Indexed: 11/30/2022]
Abstract
A non-invasive imaging method to monitor islet grafts could provide novel and improved insight into the fate of transplanted islets and, potentially, monitor the effect of therapeutic interventions. Therefore, such an imaging method could help improve long-term transplantation outcome. Here, we investigated the use of [ 123 I]IBZM for insulin positive graft volume quantification and longitudinal graft monitoring. SPECT images were acquired 6 weeks after islet transplantation in the calf muscle of rats. For longitudinal graft analysis, rats were monitored by SPECT for 10 weeks. After animals were euthanized, graft containing muscles were dissected for ex vivo analysis and insulin-positive graft volume determination. Six weeks after transplantation, a clear signal was observed in all grafts by SPECT imaging. Moreover, the intensity of the SPECT signal correlated linearly with insulin-positive graft volume, as determined histologically. Longitudinal graft follow-up showed a clear SPECT signal of the transplant from 3 until 10 weeks after transplantation. In this study, we demonstrate for the first time the successful application of a radiotracer, [ 123 I]IBZM, for non-invasive, in vivo graft volume quantification and longitudinal graft monitoring.
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Affiliation(s)
- Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Inge van der Kroon
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Desirée Bos
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cathelijne Frielink
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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van der Kroon I, Andralojc K, Willekens SMA, Bos D, Joosten L, Boerman OC, Brom M, Gotthardt M. Noninvasive Imaging of Islet Transplants with 111In-Exendin-3 SPECT/CT. J Nucl Med 2016; 57:799-804. [PMID: 26795287 DOI: 10.2967/jnumed.115.166330] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/07/2015] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Islet transplantation is a promising treatment for type 1 diabetic patients. However, there is acute as well as chronic loss of islets after transplantation. A noninvasive imaging method that could monitor islet mass might help to improve transplantation outcomes. In this study, islets were visualized after transplantation in a rat model with a dedicated small-animal SPECT scanner by targeting the glucagonlike peptide-1 receptor (GLP-1R), specifically expressed on β-cells, with (111)In-labeled exendin-3. METHODS Targeting of (111)In-exendin-3 to GLP-1R was tested in vitro on isolated islets of WAG/Rij rats. For in vivo evaluation, 400 or 800 islets were transplanted into the calf muscle of WAG/Rij rats (6-8 wk old). Four weeks after transplantation, SPECT/CT images were acquired 1 h after injection of (111)In-labeled exendin-3. After SPECT acquisition, the muscles containing the transplant were analyzed immunohistochemically and autoradiographically. RESULTS The binding assay, performed on isolated islets, showed a linear correlation between the number of islets and (111)In-exendin-3 accumulation (Pearson r = 0.98). In vivo, a 1.70 ± 0.44-fold difference in tracer uptake between 400 and 800 transplanted islets was observed. Ex vivo analysis of the islet transplant showed colocalization of tracer accumulation on autoradiography, with insulin-positive cells and GLP-1R expression on immunohistochemistry. CONCLUSION (111)In-exendin-3 accumulates specifically in the β-cells after islet transplantation and is a promising tracer for noninvasive monitoring of the islet mass.
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Affiliation(s)
- Inge van der Kroon
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Karolina Andralojc
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Desirée Bos
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
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Willekens SMA, van der Kroon I, Joosten L, Frielink C, Boerman OC, van den Broek SAMW, Brom M, Gotthardt M. SPECT of Transplanted Islets of Langerhans by Dopamine 2 Receptor Targeting in a Rat Model. Mol Pharm 2015; 13:85-91. [PMID: 26607139 DOI: 10.1021/acs.molpharmaceut.5b00518] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pancreatic islet transplantation can be a more permanent treatment for type 1 diabetes compared to daily insulin administration. Quantitative and longitudinal noninvasive imaging of viable transplanted islets might help to further improve this novel therapy. Since islets express dopamine 2 (D2) receptors, they could be visualized by targeting this receptor. Therefore, the D2 receptor antagonist based tracer [(125/123)I][IBZM] was selected to visualize transplanted islets in a rat model. BZM was radioiodinated, and the labeling was optimized for position 3 of the aromatic ring. [(125)I]-3-IBZM was characterized in vitro using INS-1 cells and isolated islets. Subsequently, 1,000 islets were transplanted in the calf muscle of WAG/Rij rats and SPECT/CT images were acquired 6 weeks after transplantation. Finally, the graft containing muscle was dissected and analyzed immunohistochemically. Oxidative radioiodination resulted in 3 IBZM isomers with different receptor affinities. The use of 0.6 mg/mL chloramine-T hydrate resulted in high yield formation of predominantly [(125)I]-3-IBZM, the isomer harboring the highest receptor affinity. The tracer showed D2 receptor mediated binding to isolated islets in vitro. The transplant could be visualized by SPECT 6 weeks after transplantation. The transplants could be localized in the calf muscle and showed insulin and glucagon expression, indicating targeting of viable and functional islets in the transplant. Radioiodination was optimized to produce high yields of [(125)I]-3-IBZM, the isomer showing optimal D2R binding. Furthermore, [(123)I]IBZM specifically targets the D2 receptors on transplanted islets. In conclusion, this tracer shows potential for noninvasive in vivo detection of islets grafted in the muscle by D2 receptor targeting.
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Affiliation(s)
- Stefanie M A Willekens
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Inge van der Kroon
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Cathelijne Frielink
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Otto C Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | | | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center , PO Box 9101, 6500 HB Nijmegen, The Netherlands
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