Targeting glucocorticoid receptor signaling pathway for treatment of stress-related brain disorders.

The hypothalamic-pituitary-adrenal (HPA) axis plays a central role in governing stress-related disorders such as major depressive disorder (MDD), anxiety, and post-traumatic stress disorder. Chronic stress or early life trauma, known risk factors of disease, alter HPA axis activity and pattern of glucocorticoid (GC) secretion. These changes have consequences for physiological processes controlled by glucocorticoid receptor (GR) signaling, such as immune response and metabolism. In the brain, the aberrant GR signaling translates to altered behavior, making the GR pathway a viable target for therapies of stress-related disorders. One of the crucial elements of the pathway is FKBP5, a regulator of GR sensitivity and feedback control within the HPA axis, in which genetic variants were shown to moderate the risk of developing psychiatric conditions. The difficulty in targeting the GR-FKBP5 pathway stems from tailoring the intervention to specific brain regions and cell types, in the context of personalized genetic variations in GR and GR-associated genes, like FKBP5. The development of selective inhibitors, antagonists, and approaches based on targeted protein degradation offer insights into mechanistic aspects of disease and pave the way for improved therapy. These strategies can be employed either independently or in conjunction with conventional medications. Concomitant advancements in personalized drug screening (e.g. in vitro models exploiting induced pluripotent stem cells, iPSCs) bring the potential for optimization of therapy aiming to rescue central deficits originating from the HPA imbalance. In this mini-review, we discuss potential therapeutic strategies targeting GR signaling in stress-related disorders, with a focus on personalized approaches and advancements in drug development.