The miR-92a–Cpeb3 axis safeguards neuronal function during neuroinflammation

Neuroinflammation causes neuronal injury in multiple sclerosis (MS) and other neurological diseases. MicroRNAs (miRNAs) are central modulators of cellular stress responses, but knowledge about miRNA–mRNA interactions that determine neuronal outcome during inflammation is limited. Here, we combined unbiased neuron-specific miRNA with mRNA sequencing to assemble the regulatory network that mediates robustness against neuroinflammation. As a critical miRNA-network hub we defined miR-92a. Genetic deletion of miR-92a exacerbated the disease course of mice undergoing experimental autoimmune encephalomyelitis (EAE), whereas miR-92a overexpression protected neurons against excitotoxicity. As a key miR-92a target transcript, we identified cytoplasmic polyadenylation element-binding protein 3 (Cpeb3) that was suppressed in inflamed neurons in mouse EAE and human MS. Accordingly, Cpeb3 deletion improved neuronal resistance to excitotoxicity and ameliorated EAE. Together, we discovered that the miR-92a–Cpeb3 axis confers neuronal robustness against inflammation and serves as potential target for neuroprotective therapies. miRNA of Chat+ spinal cord motor neurons derived from mice undergoing experimental autoimmune encephalomyelitis (EAE) and healthy control mice was enriched by miRNA tagging and affinity-purification (miRAP) and sequenced by small RNA-seq.