The Synthesis and Structural Requirements for Measuring Glucocorticoid Receptor Expression In Vivo with (±)-¹¹C-YJH08...

Area of Science:

• Nuclear Medicine
• Pharmacology
• Molecular Biology

Background:

• Noninvasive methods are crucial for studying glucocorticoid receptor (GR) signaling in physiology and disease.
• Understanding GR signaling complexity is vital for developing selective GR modulators for therapeutic applications.

Purpose of the Study:

• To report translational studies of (±)-¹¹C-YJH08, a novel positron emission tomography (PET) radioligand for GR.
• To evaluate (±)-¹¹C-YJH08 for its potential in measuring GR expression in human subjects.

Main Methods:

• Synthesis of (±)-¹¹C-YJH08 via reaction of a phenol precursor with ¹¹C-methyl iodide.
• In vivo biodistribution, specific binding assays (adrenalectomy, ligand competition), and structure-activity relationship studies.
• Rodent dosimetry studies to estimate human-equivalent doses.

Main Results:

• Successful synthesis of (±)-¹¹C-YJH08 with a radiochemical yield of 51.7% ± 4.7%.
• Observed specific binding in various tissues, including the brain, indicating effective GR engagement.
• Identified the aryl fluoride motif as essential for high-affinity binding, tissue uptake, and blood-brain barrier penetration.

Conclusions:

• The study reveals key molecular determinants for high-affinity and selective GR ligand-receptor interactions.
• Results support the utility of (±)-¹¹C-YJH08 PET for noninvasive GR expression measurements in humans.
• This advancement holds promise for understanding GR roles in health and disease and for guiding therapeutic strategies.