Mechanism of STING-mediated Neuropathology in Niemann-Pick Disease

Niemann-Pick disease type C (NPC) is a fatal neurodegenerative disease caused by genetic mutations in the NPC1 (95%) and NPC2 (5%) genes. Neurological features of NPC bear striking resemblances with Alzheimer’s disease (AD), leading to some experts considering NPC as “Childhood Alzheimer’s”. No FDA-approved therapy is available. Lipids and cholesterol defects associated with the NPC disease are well understood. However, immune pathways underlying neuroinflammation and Purkinje cell death in the NPC disease remain unknown. We recently found that the innate immune STING pathway is activated by NPC-deficiency, and genetic deletions of STING pathway components in mice are able to remarkably rescue NPC neuropathology. The overall goal of this project is to understand how STING drives neuropathology associated with the NPC disease. Aim 1 will focus on intracellular mechanisms, where we will dissect how STING signaling is activated by NPC-deficiency. Aim 2 will focus on brain tissue pathology, where we will comprehensively determine STING expression cell types, activities and their functional contribution to the NPC disease. Aim 3 will focus on therapeutic assessment, where we will treat Npc1-/- mice and NPC1 patient iPSC-derived cells with existing and new STING pathway inhibitors. STING has been implicated in several neurodegenerative diseases including Parkinson’s disease, ALS/FTD and now NPC1. Studies proposed here will provide a much-needed comprehensive understanding of STING pathway function in the brain as well as a step-by-step mechanism from STING activation to neuropathology.