[HTML][HTML] DNA damage contributes to neurotoxic inflammation in Aicardi-Goutières syndrome astrocytes

AMS Giordano, M Luciani, F Gatto… - Journal of Experimental …, 2022 - rupress.org
AMS Giordano, M Luciani, F Gatto, M Abou Alezz, C Beghè, L Della Volpe, A Migliara
Journal of Experimental Medicine, 2022rupress.org
Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-
Goutières syndrome (AGS), but the mechanisms triggering disease in the human central
nervous system (CNS) remain elusive. Here, we generated human models of AGS using
genetically modified and patient-derived pluripotent stem cells harboring TREX1 or
RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that
spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades …
Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-Goutières syndrome (AGS), but the mechanisms triggering disease in the human central nervous system (CNS) remain elusive. Here, we generated human models of AGS using genetically modified and patient-derived pluripotent stem cells harboring TREX1 or RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades impacting multiple CNS cell subsets analyzed at the single-cell level. We identify accumulating DNA damage, with elevated R-loop and micronuclei formation, as a driver of STING- and NLRP3-related inflammatory responses leading to the secretion of neurotoxic mediators. Importantly, pharmacological inhibition of proapoptotic or inflammatory cascades in AGS astrocytes prevents neurotoxicity without apparent impact on their increased type I IFN responses. Together, our work identifies DNA damage as a major driver of neurotoxic inflammation in AGS astrocytes, suggests a role for AGS gene products in R-loop homeostasis, and identifies common denominators of disease that can be targeted to prevent astrocyte-mediated neurotoxicity in AGS.
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