Distinct Impact of Neuronal and Astrocytic IFNAR1 Loss in Parkinson-like Dementia

Interferon-alpha/beta-receptor (IFNAR) signal defects were recently identified to contribute to sporadic Parkinson’s disease (PD) with dementia (PDD). Mice lacking interferon-beta (IFNβ) develop PDD-like disease; however, the phenotypic, cellular, and molecular impacts of IFNAR1 loss in vivo have not been explored. Studying cell-specific pathology in Ifnar1-/- mice may reveal potential disease-modifying therapeutic targets for PDD. Here, we present that Ifnar1-/- mice exhibit PDD-like pathogenesis, including dopaminergic neurodegeneration in the substantia nigra, Lewy-body-like alpha-synuclein+ inclusions, gliosis-associated phosphorylated-tau and amyloid-beta proteinopathy, and progressive PDD-like behavior deficits. Hallmark neuropathology and motor and cognitive behavior deficits were specifically recapitulated in mice lacking neuronal IFNAR1. Ifnar1-/- mice also exhibited early-onset nociceptive pain and neuropsychiatric abnormalities, recapitulated in mice lacking astrocytic IFNAR1. Neuron/astrocyte-specific transcriptomic and proteomic alterations in early-manifest Ifnar1-/- mice implicate synergistic dysfunctional excitatory neurotransmission upon IFNAR1 loss, leading to glucose hypermetabolism prior to cognitive decline. Targeted restoration of dysfunctional neuronal and astrocytic IFNAR1 could therefore potentially mitigate PDD progression through concerted regulation of excitatory neurotransmission.