1
|
Kong Y, Cao L, Xie F, Wang X, Zuo C, Shi K, Rominger A, Huang Q, Xiao J, Jiang D, Guan Y, Ni R. Reduced SV2A and GABA A receptor levels in the brains of type 2 diabetic rats revealed by [ 18F]SDM-8 and [ 18F]flumazenil PET. Biomed Pharmacother 2024; 172:116252. [PMID: 38325265 DOI: 10.1016/j.biopha.2024.116252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/19/2023] [Accepted: 02/02/2024] [Indexed: 02/09/2024] Open
Abstract
PURPOSE Type 2 diabetes mellitus (T2DM) is associated with a greater risk of Alzheimer's disease. Synaptic impairment and protein aggregates have been reported in the brains of T2DM models. Here, we assessed whether neurodegenerative changes in synaptic vesicle 2 A (SV2A), γ-aminobutyric acid type A (GABAA) receptor, amyloid-β, tau and receptor for advanced glycosylation end product (RAGE) can be detected in vivo in T2DM rats. METHODS Positron emission tomography (PET) using [18F]SDM-8 (SV2A), [18F]flumazenil (GABAA receptor), [18F]florbetapir (amyloid-β), [18F]PM-PBB3 (tau), and [18F]FPS-ZM1 (RAGE) was carried out in 12-month-old diabetic Zucker diabetic fatty (ZDF) and SpragueDawley (SD) rats. Immunofluorescence staining, Thioflavin S staining, proteomic profiling and pathway analysis were performed on the brain tissues of ZDF and SD rats. RESULTS Reduced cortical [18F]SDM-8 uptake and cortical and hippocampal [18F]flumazenil uptake were observed in 12-month-old ZDF rats compared to SD rats. The regional uptake of [18F]florbetapir and [18F]PM-PBB3 was comparable in the brains of 12-month-old ZDF and SD rats. Immunofluorescence staining revealed Thioflavin S-negative, phospho-tau-positive inclusions in the cortex and hypothalamus in the brains of ZDF rats and the absence of amyloid-beta deposits. The level of GABAA receptors was lower in the cortex of ZDF rats than SD rats. Proteomic analysis further demonstrated that, compared with SD rats, synaptic-related proteins and pathways were downregulated in the hippocampus of ZDF rats. CONCLUSION These findings provide in vivo evidence for regional reductions in SV2A and GABAA receptor levels in the brains of aged T2DM ZDF rats.
Collapse
Affiliation(s)
- Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Lei Cao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China; Inst. Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Fang Xie
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiuzhe Wang
- Dept. Neurology, Shanghai Sixth People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Kuangyu Shi
- Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Axel Rominger
- Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
| | - Qi Huang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianfei Xiao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Donglang Jiang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Ruiqing Ni
- Inst. Regenerative Medicine, University of Zurich, Zurich, Switzerland; Dept. Nuclear Medicine, Inselspital, Bern University Hospital, Bern, Switzerland; Inst. Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
2
|
Dobrucki IT, Miskalis A, Nelappana M, Applegate C, Wozniak M, Czerwinski A, Kalinowski L, Dobrucki LW. Receptor for advanced glycation end-products: Biological significance and imaging applications. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2024; 16:e1935. [PMID: 37926944 DOI: 10.1002/wnan.1935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/25/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023]
Abstract
The receptor for advanced glycation end-products (RAGE or AGER) is a transmembrane, immunoglobulin-like receptor that, due to its multiple isoform structures, binds to a diverse range of endo- and exogenous ligands. RAGE activation caused by the ligand binding initiates a cascade of complex pathways associated with producing free radicals, such as reactive nitric oxide and oxygen species, cell proliferation, and immunoinflammatory processes. The involvement of RAGE in the pathogenesis of disorders such as diabetes, inflammation, tumor progression, and endothelial dysfunction is dictated by the accumulation of advanced glycation end-products (AGEs) at pathologic states leading to sustained RAGE upregulation. The involvement of RAGE and its ligands in numerous pathologies and diseases makes RAGE an interesting target for therapy focused on the modulation of both RAGE expression or activation and the production or exogenous administration of AGEs. Despite the known role that the RAGE/AGE axis plays in multiple disease states, there remains an urgent need to develop noninvasive, molecular imaging approaches that can accurately quantify RAGE levels in vivo that will aid in the validation of RAGE and its ligands as biomarkers and therapeutic targets. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Diagnostic Tools > Biosensing.
Collapse
Affiliation(s)
- Iwona T Dobrucki
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Department of Biomedical and Translational Sciences, Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Academy of Medical and Social Applied Sciences, Elblag, Poland
| | - Angelo Miskalis
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Michael Nelappana
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
| | - Catherine Applegate
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Cancer Center at Illinois, Urbana, Illinois, USA
| | - Marcin Wozniak
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Division of Medical Laboratory Diagnostics-Fahrenheit Biobank BBMRI.pl, Medical University of Gdansk, Gdansk, Poland
| | - Andrzej Czerwinski
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
| | - Leszek Kalinowski
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Division of Medical Laboratory Diagnostics-Fahrenheit Biobank BBMRI.pl, Medical University of Gdansk, Gdansk, Poland
- BioTechMed Centre, Department of Mechanics of Materials and Structures, Gdansk University of Technology, Gdansk, Poland
| | - Lawrence W Dobrucki
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Department of Biomedical and Translational Sciences, Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Cancer Center at Illinois, Urbana, Illinois, USA
- Division of Medical Laboratory Diagnostics-Fahrenheit Biobank BBMRI.pl, Medical University of Gdansk, Gdansk, Poland
| |
Collapse
|
3
|
Harris WJ, Asselin MC, Hinz R, Parkes LM, Allan S, Schiessl I, Boutin H, Dickie BR. In vivo methods for imaging blood-brain barrier function and dysfunction. Eur J Nucl Med Mol Imaging 2023; 50:1051-1083. [PMID: 36437425 PMCID: PMC9931809 DOI: 10.1007/s00259-022-05997-1] [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: 03/31/2022] [Accepted: 10/09/2022] [Indexed: 11/29/2022]
Abstract
The blood-brain barrier (BBB) is the interface between the central nervous system and systemic circulation. It tightly regulates what enters and is removed from the brain parenchyma and is fundamental in maintaining brain homeostasis. Increasingly, the BBB is recognised as having a significant role in numerous neurological disorders, ranging from acute disorders (traumatic brain injury, stroke, seizures) to chronic neurodegeneration (Alzheimer's disease, vascular dementia, small vessel disease). Numerous approaches have been developed to study the BBB in vitro, in vivo, and ex vivo. The complex multicellular structure and effects of disease are difficult to recreate accurately in vitro, and functional aspects of the BBB cannot be easily studied ex vivo. As such, the value of in vivo methods to study the intact BBB cannot be overstated. This review discusses the structure and function of the BBB and how these are affected in diseases. It then discusses in depth several established and novel methods for imaging the BBB in vivo, with a focus on MRI, nuclear imaging, and high-resolution intravital fluorescence microscopy.
Collapse
Affiliation(s)
- William James Harris
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Marie-Claude Asselin
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
| | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK
| | - Laura Michelle Parkes
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Stuart Allan
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Ingo Schiessl
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Herve Boutin
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
| | - Ben Robert Dickie
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
| |
Collapse
|
4
|
Alarmins S100A8/A9 promote intervertebral disc degeneration and inflammation-related pain in a rat model through toll-like receptor-4 and activation of the NF-κB signaling pathway. Osteoarthritis Cartilage 2022; 30:998-1011. [PMID: 35405347 DOI: 10.1016/j.joca.2022.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The molecules released from cells undergoing necrosis are recognized as alarmins, and S100A8/9, a typical alarmin, is associated with several inflammation-related diseases. This study was to investigate the molecular role of S100A8/A9 on the process of intervertebral disc degeneration (IVDD) and inflammation-related pain. METHODS The expression pattern of S100A8/A9 in different degenerated human nucleus pulposus (NP) tissues were measured by Real-time quantitative reverse transcription PCR (RT-qPCR) and immunohistochemical (IHC). The effects of S100A8/A9 on matrix production were assessed by RT-qPCR, western blotting, and cell immunofluorescence. Involvement of TLR4 and NF-κB signaling pathways were studied by pharmachemical inhibitors and small interfering RNAs (siRNAs). The development of degenerative and pain features in the IVDD model were examed by IHC and pain-behavior testing. RESULTS The expression of S100A8/A9 was significantly elevated in severely degenerated human NP tissue with similar expression pattern of TNF-α. In NP cells, S100A8/A9 increased MMP-3/13, TNF-α, IL-6 expression and inhibited aggrecan and collagen II expression. RT-qPCR and western blotting showed that the regulatory effects of S100A8/A9 on IVD were TLR4 dependent. Pharmacological inhibition or siRNA knockdown of the NF-κB signaling attenuated S100A8/A9-induced upregulation of MMP-3/13, TNF-α and IL-6. In vivo, S100A9 inhibitor treatment inhibited disc-puncture induced IVDD and inflammation-related pain. CONCLUSIONS This study showed that S100A8/A9 bound to TLR4 and increased the expression of MMPs, TNF-α, and IL-6 through NF-κB signaling pathways in NP cells. Furthermore, S100A8/A9 inhibitor could prevent development of IVDD and inflammation-related pain in the rat model.
Collapse
|
5
|
Liu P, Jiang C. Brain-targeting drug delivery systems. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2022; 14:e1818. [PMID: 35596258 DOI: 10.1002/wnan.1818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 12/11/2022]
Abstract
Brain diseases, including neurodegenerative diseases, acute ischemic stroke and brain tumors, have become a major health problem and a huge burden on society with high morbidity and mortality. However, most of the current therapeutic drugs can only relieve the symptoms of brain diseases, and it is difficult to achieve satisfactory therapeutic effects fundamentally. Extensive studies have shown that the therapeutic effects of brain diseases are mainly affected by two factors: the conservation of the blood-brain barrier (BBB) and the complexity of the brain micro-environment. Brain-targeting drug delivery systems provide new possibilities for overcoming these barriers with versatility. In this review, it provides an overview of BBB alteration and discusses targeting delivery strategies for brain diseases therapy. Furthermore, delivery systems which are designed to modulate the brain micro-environment with synergistic effects were also highlighted. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.
Collapse
Affiliation(s)
- Peixin Liu
- Key Laboratory of Smart Drug Delivery, Ministry of Education, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China
| | - Chen Jiang
- Key Laboratory of Smart Drug Delivery, Ministry of Education, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China
| |
Collapse
|
6
|
Liu D, Huang J, Gao S, Jin H, He J. A temporo-spatial pharmacometabolomics method to characterize pharmacokinetics and pharmacodynamics in the brain microregions by using ambient mass spectrometry imaging. Acta Pharm Sin B 2022; 12:3341-3353. [PMID: 35967273 PMCID: PMC9366215 DOI: 10.1016/j.apsb.2022.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/10/2022] [Accepted: 03/20/2022] [Indexed: 11/01/2022] Open
|
7
|
Chen Z, Haider A, Chen J, Xiao Z, Gobbi L, Honer M, Grether U, Arnold SE, Josephson L, Liang SH. The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO. J Med Chem 2021; 64:17656-17689. [PMID: 34905377 PMCID: PMC9094091 DOI: 10.1021/acs.jmedchem.1c01571] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.
Collapse
Affiliation(s)
- Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Jiahui Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Zhiwei Xiao
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Luca Gobbi
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Michael Honer
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Uwe Grether
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Steven E. Arnold
- Department of Neurology and the Massachusetts Alzheimer’s Disease Research Center, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| |
Collapse
|
8
|
Ni R. Positron Emission Tomography in Animal Models of Alzheimer's Disease Amyloidosis: Translational Implications. Pharmaceuticals (Basel) 2021; 14:1179. [PMID: 34832961 PMCID: PMC8623863 DOI: 10.3390/ph14111179] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Animal models of Alzheimer's disease amyloidosis that recapitulate cerebral amyloid-beta pathology have been widely used in preclinical research and have greatly enabled the mechanistic understanding of Alzheimer's disease and the development of therapeutics. Comprehensive deep phenotyping of the pathophysiological and biochemical features in these animal models is essential. Recent advances in positron emission tomography have allowed the non-invasive visualization of the alterations in the brain of animal models and in patients with Alzheimer's disease. These tools have facilitated our understanding of disease mechanisms and provided longitudinal monitoring of treatment effects in animal models of Alzheimer's disease amyloidosis. In this review, we focus on recent positron emission tomography studies of cerebral amyloid-beta accumulation, hypoglucose metabolism, synaptic and neurotransmitter receptor deficits (cholinergic and glutamatergic system), blood-brain barrier impairment, and neuroinflammation (microgliosis and astrocytosis) in animal models of Alzheimer's disease amyloidosis. We further propose the emerging targets and tracers for reflecting the pathophysiological changes and discuss outstanding challenges in disease animal models and future outlook in the on-chip characterization of imaging biomarkers towards clinical translation.
Collapse
Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH & University of Zurich, 8093 Zurich, Switzerland;
- Institute for Regenerative Medicine, University of Zurich, 8952 Zurich, Switzerland
| |
Collapse
|
9
|
Kitaura A, Nishinaka T, Hamasaki S, Hatipoglu OF, Wake H, Nishibori M, Mori S, Nakao S, Takahashi H. Advanced glycation end-products reduce lipopolysaccharide uptake by macrophages. PLoS One 2021; 16:e0245957. [PMID: 33493233 PMCID: PMC7833212 DOI: 10.1371/journal.pone.0245957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/11/2021] [Indexed: 01/19/2023] Open
Abstract
Hyperglycaemia provides a suitable environment for infections and the mechanisms of glucose toxicity include the formation of advanced glycation end-products (AGEs), which comprise non-enzymatically glycosylated proteins, lipids, and nucleic acid amino groups. Among AGE-associated phenotypes, glycolaldehyde-derived toxic AGE (AGE-3) is involved in the pathogenesis of diabetic complications. Internalisation of endotoxin by various cell types contributes to innate immune responses against bacterial infection. An endotoxin derived from Gram-negative bacteria, lipopolysaccharide (LPS), was reported to enhance its own uptake by RAW264.7 mouse macrophage-like cells, and an LPS binding protein, CD14, was involved in the LPS uptake. The LPS uptake induced the activation of RAW264.7 leading to the production of chemokine CXC motif ligand (CXCL) 10, which promotes T helper cell type 1 responses. Previously, we reported that AGE-3 was internalised into RAW264.7 cells through scavenger receptor-1 Class A. We hypothesized that AGEs uptake interrupt LPS uptake and impair innate immune response to LPS in RAW264.7 cells. In the present study, we found that AGE-3 attenuated CD14 expression, LPS uptake, and CXCL10 production, which was concentration-dependent, whereas LPS did not affect AGE uptake. AGEs were reported to stimulate the receptor for AGEs and Toll-like receptor 4, which cause inflammatory reactions. We found that inhibitors for RAGE, but not Toll-like receptor 4, restored the AGE-induced suppression of CD14 expression, LPS uptake, and CXCL10 production. These results indicate that the receptor for the AGE-initiated pathway partially impairs the immune response in diabetes patients.
Collapse
Affiliation(s)
- Atsuhiro Kitaura
- Department of Anesthesiology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Takashi Nishinaka
- Department of Pharmacology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Shinichi Hamasaki
- Department of Anesthesiology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Omer Faruk Hatipoglu
- Department of Pharmacology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Hidenori Wake
- Department of Pharmacology, Dentistry, and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Masahiro Nishibori
- Department of Pharmacology, Dentistry, and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Shuji Mori
- Department of Pharmacy, Shujitsu University, Okayama, Japan
| | - Shinichi Nakao
- Department of Anesthesiology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Hideo Takahashi
- Department of Pharmacology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
- * E-mail:
| |
Collapse
|
10
|
Abstract
This article presents an overview of imaging agents for PET that have been applied for research and diagnostic purposes in patients affected by dementia. Classified by the target which the agents visualize, seven groups of tracers can be distinguished, namely radiopharmaceuticals for: (1) Misfolded proteins (ß-amyloid, tau, α-synuclein), (2) Neuroinflammation (overexpression of translocator protein), (3) Elements of the cholinergic system, (4) Elements of monoamine neurotransmitter systems, (5) Synaptic density, (6) Cerebral energy metabolism (glucose transport/ hexokinase), and (7) Various other proteins. This last category contains proteins involved in mechanisms underlying neuroinflammation or cognitive impairment, which may also be potential therapeutic targets. Many receptors belong to this category: AMPA, cannabinoid, colony stimulating factor 1, metabotropic glutamate receptor 1 and 5 (mGluR1, mGluR5), opioid (kappa, mu), purinergic (P2X7, P2Y12), sigma-1, sigma-2, receptor for advanced glycation endproducts, and triggering receptor expressed on myeloid cells-1, besides several enzymes: cyclooxygenase-1 and 2 (COX-1, COX-2), phosphodiesterase-5 and 10 (PDE5, PDE10), and tropomyosin receptor kinase. Significant advances in neuroimaging have been made in the last 15 years. The use of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) for quantification of regional cerebral glucose metabolism is well-established. Three tracers for ß-amyloid plaques have been approved by the Food and Drug Administration and European Medicines Agency. Several tracers for tau neurofibrillary tangles are already applied in clinical research. Since many novel agents are in the preclinical or experimental stage of development, further advances in nuclear medicine imaging can be expected in the near future. PET studies with established tracers and tracers for novel targets may result in early diagnosis and better classification of neurodegenerative disorders and in accurate monitoring of therapy trials which involve these targets. PET data have prognostic value and may be used to assess the response of the human brain to interventions, or to select the appropriate treatment strategy for an individual patient.
Collapse
Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands.
| | - Sofia Marcolini
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands
| | - Peter Paul de Deyn
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands; University of Antwerp, Born-Bunge Institute, Neurochemistry and Behavior, Campus Drie Eiken, Wilrijk, Belgium
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands; Ghent University, Ghent, Belgium
| |
Collapse
|