The caffeine-binding adenosine A2A receptor induces age-like HPA-axis dysfunction by targeting glucocorticoid...

Area of Science:

• Neuroscience
• Pharmacology
• Aging Research

Background:

• Adenosine A2A receptor (A2AR) overactivation is linked to cognitive decline in aging and Alzheimer's disease (AD).
• Previous research suggests A2AR and glucocorticoid (GC) dysfunction contribute to age-related memory deficits.
• The direct link between A2AR overactivation and GC dysfunction in memory impairment remained unexplored.

Purpose of the Study:

• To investigate the direct connection between adenosine A2A receptor (A2AR) overactivation and glucocorticoid receptor (GR) dysfunction in age-related memory deficits.
• To explore the role of A2AR in regulating GR function and its impact on cognitive impairment.

Main Methods:

• Induced A2AR overexpression in an aging-like model.
• Assessed hypothalamic-pituitary-adrenal (HPA) axis function, corticosterone circadian rhythms, and GR levels in the hippocampus.
• Evaluated synaptic plasticity and memory deficits, and the effects of A2AR antagonism.
• Investigated A2AR's influence on GR nuclear translocation and transcriptional activity.

Main Results:

• A2AR overexpression induced HPA axis dysfunction, including loss of corticosterone rhythm, and reduced hippocampal GR levels.
• A2AR overactivation amplified GR-induced synaptic plasticity and memory deficits in the hippocampus.
• Anti-A2AR therapy rescued these deficits, demonstrating A2AR's role in modulating GR function.

Conclusions:

• Adenosine A2A receptor (A2AR) is a key regulator of glucocorticoid receptor (GR) function.
• The A2AR-GR interconnection is a potential trigger for age-related memory deficits.
• The procognitive effects of A2AR antagonists like caffeine may stem from their ability to modulate GR actions in cognitive impairment.