Small-molecule PET Tracers for Imaging Proteinopathies.

Area of Science:

• Neuroscience
• Radiochemistry
• Molecular Imaging

Background:

• Neurodegenerative diseases, or proteinopathies, are linked to aggregated amyloid proteins: amyloid-beta (Aβ), tau, and alpha-synuclein (α-syn).
• Developing effective PET imaging agents has been challenging due to difficulties in rational radioligand design, often relying on serendipitous discovery.
• Many proteinopathies involve multiple amyloid types, necessitating selective tracers to differentiate their contributions.

Purpose of the Study:

• To review the challenges and advances in creating PET imaging agents for Aβ, tau, and α-syn.
• To highlight the importance of selective tracers for diagnosing and understanding various neurodegenerative diseases.
• To discuss ongoing efforts and future directions in developing novel imaging agents.

Main Methods:

• Review of existing literature on PET imaging agent development for Aβ, tau, and α-syn.
• Illustrative examples of successful Aβ PET tracer development, such as Pittsburgh compound B.
• Discussion of ongoing research and challenges in developing selective tau and α-syn PET tracers.

Main Results:

• Significant progress has been made in developing selective PET tracers for Aβ and tau.
• Effective selective PET imaging agents for α-synuclein have not yet been realized, but research is active.
• Understanding the different forms of tau (3-repeat and 4-repeat) is critical for developing specific tau PET ligands.

Conclusions:

• Selective PET imaging agents are essential for accurate diagnosis and management of proteinopathies.
• Continued research is needed to overcome challenges in developing selective tracers, particularly for α-synuclein.
• Advances in PET imaging agents will improve our ability to assess amyloid burden and guide therapeutic strategies for neurodegenerative diseases.