# Attenuating microglial-dependent axonal pathology in EAE

> **NIH VA I01** · VA VETERANS ADMINISTRATION HOSPITAL · 2020 · —

## Abstract

Project Summary:
Nearly 30,000 US veterans are in the VA system being treated for Multiple Sclerosis (MS), a disabling disease
that results in motor, sensory and cognitive dysfunction. There is no cure and treatments have limited efficacy.
The overall goal of my lab is to provide a better understanding of the pathologic mechanisms that drive MS in
order to develop new and better treatment options. MS is classically described as a demyelinating disorder
where myelin loss is accompanied by axonal damage and irreversible neurological dysfunction. The prevail-
ing theme is that axonal pathology in MS is consequential of chronic, long term demyelination. Although axon-
al pathology clearly results from long term myelin loss, we propose that axonal pathology is also a primary
event in MS that occurs early in disease and independent of demyelination. Supportive of this idea, axonal
pathology is observed in both normal appearing white and grey matter; MS plaque load does not correlate
with axonal loss; and axonal number is reduced in regions lacking myelin loss . In further support that axonal
damage occurs independent of myelin loss and at very early stages of disease, we recently demonstrated that
axonal pathology is indeed a primary event in experimental autoimmune encephalomyelitis (EAE), a mouse
model of MS. Our findings indicate that the axon initial segment (AIS), the myelin-bare, initial region of the ax-
on responsible for action potential initiation and modulation, is specifically targeted by pro-inflammatory, reac-
tive microglia in the absence of myelin loss resulting in subsequent AIS disruption. Moreover, we showed that
anti-inflammatory treatment not only decreased microglial reactivity and microglia/AIS contact but also result-
ed in amelioration of AIS disruption and in AIS restoration. The clinical relevance of these findings is support-
ed by our most recent observations indicating that a similar AIS disruption also occurs in MS. Based on our
findings, our working hypothesis is that in MS reactive microglia migrate toward injury cues and undergo mor-
phologic change resulting in increased contact with the AIS facilitating the targeting of pro-inflammatory fac-
tors promoting AIS disruption independent of demyelination. Moreover, we propose that inhibition of microglia
response and interaction with the AIS will result in AIS preservation and restoration. Here, we present strong
preliminary data that a novel isoform of the cell adhesion molecule neurofascin (Nfasc) mediates the microglia
response in the MS model of EAE. Based on our findings and known functions of other Nfasc isoforms, we
predict that microglia-specific ablation of Nfasc will 1. inhibit microglial migration, surveillance and cytokine
secretion by disrupting actin dynamics and 2. result in structural and functional AIS preservation in EAE.

## Key facts

- **NIH application ID:** 9889586
- **Project number:** 2I01BX002565-05
- **Recipient organization:** VA VETERANS ADMINISTRATION HOSPITAL
- **Principal Investigator:** Jeffrey L. Dupree
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 2
- **Project period:** 2015-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9889586

## Citation

> US National Institutes of Health, RePORTER application 9889586, Attenuating microglial-dependent axonal pathology in EAE (2I01BX002565-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9889586. Licensed CC0.

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