W181 - CLEC16A-driven Mitophagy Limits Astrocyte Proinflammatory Activities

Michael Wheeler – Neurology – BWH, Harvard Medical School; Zhaorong Li – Neurology – BWH, Harvard Medical School; Alain Ndayisaba – Neurology – BWH, Harvard Medical School; Stephanie Zandee – Neuroscience – Universite de Montreal; Himanish Basu – Immunology – Harvard Medical School; Brian Andersen – Neurology – BWH, Harvard Medical School; Joao Mahler – Neurology – BWH, Harvard Medical School; Isaac Chiu – Immunology – Harvard Medical School; Alexandre Prat – Neuroscience – Universite de Montreal; Vikram Khurana – Neurology – BWH, Harvard Medical School; Francisco Quintana – Neurology – BWH, Harvard Medical School

Abstract Text: Astrocytes are abundant glial cells in the central nervous system, with important roles in the pathology of multiple sclerosis (MS). In a genome-wide CRISPR-based forward genetic screen we identified CLEC16A, a gene linked to MS susceptibility, as a suppressor of astrocyte pro-inflammatory activities. Gene and small molecule perturbation studies in mouse primary and human embryonic stem cell-derived astrocytes in combination with metabolic and bulk and single-cell transcriptional analyses established that CLEC16A promotes mitophagy, limiting the accumulation of mitochondrial products that activate NF-κB, the NLRP3 inflammasome and gasdermin D. Astrocyte-specific Clec16a inactivation increased NF-κB, NLRP3 and gasdermin D activation in vivo, worsening experimental autoimmune encephalomyelitis, a pre-clinical model of MS. Moreover, we detected disrupted mitophagic capacity and gasdermin D activation in astrocytes in MS. These findings identify CLEC16A-driven mitophagy as a suppressor of astrocyte pathologic responses and a candidate therapeutic target in MS and other neurological diseases.