Dementia Biomarker Development Sector

Overview

This sector is dedicated to the comprehensive development of biomarkers aimed at improving early diagnosis and pathophysiological assessment of dementia. By developing blood-based biomarkers grounded in PET imaging and integrating neuropsychological indicators, we strive to build a multidimensional diagnostic and evaluation system. Our research also explores the biological underpinnings of behavioral and psychological symptoms, as well as alterations in the oral environment, to identify potential avenues for novel therapeutic interventions across diverse clinical settings in dementia care.

Moreover, we conduct large-scale clinical studies through multi-institutional collaboration to validate the clinical utility of the developed biomarkers. Through these efforts, we aim to contribute to the realization of personalized medicine-from early detection and disease monitoring to evaluation of treatment efficacy.

Head of Sector

Kenji Tagai, M.D., Ph.D.

Senior Researcher

Board-Certified Psychiatrist, Japanese Society of Psychiatry and Neurology

Certified Geriatric Psychiatrist, Japanese Society of Geriatric Psychiatry

Board-Certified Nuclear Medicine Physician

Board Member, Japanese Society for Dementia Research

Executive Committee Member, Japanese Society of Neuropsychiatric Nuclear Medicine

Associate Editor, Journal of Alzheimer's Disease

https://researchmap.jp/ktagai

Career History

• 2011-2013: Department of Neuropsychiatry, Jikei University Hospital
• 2013-2014: Department of Psychiatry and Neurology, Machida Municipal Hospital
• 2014-2016: Hirakawa Hospital, South Tama Dementia Support Center
• 2016-Present: Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology

Awards

• September 2024: Academic Award, Japanese Society for Dementia Research
• November 2023: Best Oral Presentation Award, Japanese Society of Psychiatry and Neurology
• September 2022: Best Research Encouragement Award, Japanese Society of Nuclear Medicine
• July 2022: de Leon Prize in Neuroimaging (Trainee), Alzheimer’s Association International Conference
• December 2021: Medical Research Award, Tokyo Medical Association

Research Areas

1. Comprehensive biomarker discovery using brain imaging and body fluids for the diagnosis and pathophysiological evaluation of dementia-related disorders
2. Efficacy and safety study of [18F] EST-604, a novel PET radioligand targeting mGlu2/3R, a brain metabolic glutamate receptor
3. Population-based study on blood biomarkers for dementia in cognitively healthy individuals
4. Research on the brain-oral cavity axis

Collaborating Institutions (in Japanese alphabetical order)

1. National Institutes of Biomedical Innovation, Health and Nutrition
2. ISEIKAI International General Hospital, Center for Dementia Prevention and Care
3. Department of Psychiatry, Osaka University
4. Department of Neurology, Kyoto Prefectural University of Medicine
5. Center for Neurodegenerative Diseases, Shiga University of Medical Science
6. Department of Neurology, Juntendo University Hospital
7. Department of Neurology, Chiba University Graduate School of Medicine
8. Department of Neuropsychiatry, University of Tsukuba Hospital
9. Department of Oral and Maxillofacial Radiology, Tokyo Dental College
10. Department of Psychiatry, Jikei University School of Medicine

Selected Publications

1. Tagai K, Tatebe H, Matsuura S, et al. A novel plasma p-tau181 assay as a specific biomarker of tau pathology in Alzheimer's disease. Translational Neurodegeneration 2024; 13: 44.
2. Tagai K, Ikoma Y, Endo H, et al. An optimized reference tissue method for quantification of tau protein depositions in diverse neurodegenerative disorders by PET with18F-PM-PBB3 (18F-APN-1607). NeuroImage 2022; 264: 119763.
3. Tagai K, Ono M, Kubota M, et al. High-Contrast In Vivo Imaging of Tau Pathologies in Alzheimer's and Non-Alzheimer's Disease Tauopathies. Neuron 2021; 109: 42-58.
4. Endo H, Tagai K, Ono M, et al. A Machine Learning-Based Approach to Discrimination of Tauopathies Using [18F]PM-PBB3 PET Images. Movement Disorders 2022; 37: 2236-2246.
5. Suzuki H, Tagai K, Ono M, et al. Distinct tau pathologies in the nucleus basalis of Meynert between early-onset and late-onset Alzheimer's disease patients revealed by positron emission tomography. Journal of Alzheimer's Disease 2024; 13872877241297382.
6. Matsumoto H, Tagai K, Endo H, et al. Association of Tooth Loss with Alzheimer's Disease Tau Pathologies Assessed by Positron Emission Tomography. Journal of Alzheimer's Disease 2023; 96: 1253-1265.
7. Nakamura K, Tagai K, Shinotoh H, et al. Concurrent Alzheimer’s Disease Pathologies Affects Cognitive Decline and Glucose Metabolism in Lewy Body Diseases: A Multimodal PET Study. Journal of Alzheimer's Disease 2025 (in press)
8. Hirata K, Matsuoka K, Tagai K, et al. Altered Brain Energy Metabolism Related to Astrocytes in Alzheimer's Disease. Annals of Neurology 2023; 96: 247-261.
9. Hirata K, Matsuoka K, Tagai K, et al. In Vivo Assessment of Astrocyte Reactivity in Patients with Progressive Supranuclear Palsy. Annals of Neurology 2024; 96: 247-261.
10. Matsuoka K, Hirata K, Kokubo N, Maeda T, Tagai K, et al. Investigating neural dysfunction with abnormal protein deposition in Alzheimer's disease through magnetic resonance spectroscopic imaging, plasma biomarkers, and positron emission tomography. NeuroImage Clinical 2023; 41: 103560.