Role of CRF Receptor Signaling in Stress Vulnerability, Anxiety, and Depression

Publisher Website
Google Scholar
Abstract
Markers of hyperactive central corticotropin releasing factor (CRF) systems and CRF‐related single nucleotide polymorphisms (SNPs) have been identified in patients with anxiety and depressive disorders. Designing more effective antagonists may now be guided by data showing that small molecules bind to transmembrane domains. Specifically, CRF1 receptor antagonists have been developed as novel anxiolytic and antidepressant treatments. Because CRF1 receptors become rapidly desensitized by G protein‐coupled receptor kinase (GRK) and β‐arrestin mechanisms in the presence of high agonist concentrations, neuronal hypersecretion of synaptic CRF alone may be insufficient to account for excessive central CRF neurotransmission in stress‐induced affective pathophysiology. In addition to desensitizing receptor function, GRK phosphorylation and β‐arrestin binding can shift a G protein‐coupled receptor (GPCR) to signal selectively via the extracellular signal‐regulated kinase/mitogen‐activated protein kinase (ERK‐MAPK) or Akt pathways independent of G proteins. Also, Epac‐dependent CRF1 receptor signaling via the ERK‐MAPK pathway has been found to potentiate brain‐derived neurotrophic factor (BDNF)‐stimulated TrkB signaling. Thus, genetic or acquired abnormalities in GRK and β‐arrestin function may be involved in the pathophysiology of stress‐induced anxiety and depression.