Background: Calcium dyshomeostasis and membrane damage drive axon degeneration after inflammation and trauma, which can be prevented by calcium clearance and resealing.
Hypothesis: Calcium clearance and membrane resealing are checkpoints of axon survival and potential disease-spanning targets for intervention.
Strategy: To develop assays for axonal calcium clearance and membrane resealing in order to explore mechanism of axon repair as intervention targets.
Degeneration of axons in the white matter critically determines the extent of permanent neurological disability in traumatic, as well as inflammatory conditions of the central nervous system (CNS). While the primary insults differ, our recent work indicates that calcium influx due to plasma membrane damage is an important shared mechanism of traumatic and inflammatory axon degeneration. How such membrane damage is repaired and calcium homeostasis re-established emerges as a critical intrinsic checkpoint of axonal survival and recovery. A better cellular and molecular understanding of the regulation of these checkpoints might hence yield novel disease-spanning targets for therapeutic intervention. We want to explore this regulation in the complex environment of the CNS after traumatic or neuroinflammatory damage. In particular, we plan to pursue the following specific aims:
Aim ❶ Monitor and modify the molecular checkpoints that regulate calcium clearance
We will develop in vivo imaging approaches to determine the organelles that clear excessive calcium in axons. We will identify key molecular gatekeepers by expression profiling and use genetic and pharmacological interventions to examine how clearance can be modulated to limit axon fragmentation in mouse models of spinal cord contusion injury (cSCI) and multiple sclerosis (MS).
Aim ❷ Monitor and modify molecular checkpoints of axonal membrane resealing
We will visualize the different modes of membrane resealing in vivo and use a candidate CRISPR screen to explore the molecular pathways that set the rate of membrane repair in axons. Based on this we will develop targeted genetic and pharmacological manipulations to determine how membrane resealing can be enhanced after traumatic and inflammatory CNS insults.