Atypical Chemokine Receptor DARC/ACKR1 Is Expressed Selectively by Neurons with Regional Heterogeneity and Protects against Neuroinflammation and Cognitive Impairment.

Atypical chemokine receptors (ACKRs) regulate inflammatory responses by scavenging and sequestering chemokines. The Duffy antigen receptor for chemokines (DARC), also known as ACKR1, binds multiple inflammatory chemokines and regulates inflammation in peripheral tissues. However, the distribution and functional role of DARC/ACKR1 in the brain remain to be defined. Here, we show that DARC/ACKR1 is widely expressed throughout the mouse brain, with marked regional heterogeneity. DARC/ACKR1 is predominantly expressed by neurons and is not detected in microglia or astrocytes. Importantly, this neuronal expression pattern was also observed in the human brain. Furthermore, DARC/ACKR1 deficiency resulted in enhanced neuroinflammation, characterized by increased microglial activation and astrogliosis across multiple brain regions, particularly the hippocampus, and was accompanied by cognitive deficits. Together, these findings identify DARC/ACKR1 as a previously unrecognized neuron-specific atypical chemokine receptor that plays an important role in restraining neuroinflammation and preserving cognitive function.