# Exploring the Role of Microglia SYK Signaling in Tauopathy

> **NIH NIH F31** · UNIVERSITY OF VIRGINIA · 2024 · $38,001

## Abstract

PROJECT ABSTRACT/SUMMARY:
Tauopathies are a broad, prevalent, and lethal class of neurodegenerative disorders that affect up to 7 million
Americans. There is a tremendous need for improved therapeutic strategies to treat the conditions that fall
under this category, namely Alzheimer's disease (AD) and frontotemporal dementia (FTD). Recent work has
begun to uncover critical roles for microglia, which are brain-resident macrophages, and the function of distinct
microglial immune receptors in AD and FTD progression. Several immunoreceptor tyrosine-based activation
and inhibitory motif-containing receptors, including TREM2, CD22, and CD33, have been identified in genome-
wide association studies or animal studies. These receptors have been shown to have a critical impact on the
progression of neurodegenerative diseases in AD. Interestingly, these receptors converge downstream at
spleen tyrosine kinase (SYK). Recent findings from our lab have uncovered SYK's beneficial role in controlling
disease outcomes in an amyloid beta (Aβ) amyloidosis mouse model of AD, where it was shown to be a central
orchestrator of microglial activation. Given these insights, it is crucial to explore SYK's role in other types of
degeneration, such as that caused by pathogenically phosphorylated tau (p-tau). In preliminary studies, I found
that genetic ablation of microglia Syk in the tau-mediated PS19 mouse model of AD/FTD leads to a decreased
p-tau burden, improved cognitive function, and maintenance of homeostatic microglia signature. Given these
results, coupled with the general body of literature which concludes that aberrant innate immune activity is
detrimental to tauopathy progression and drives increased tau hyperphosphorylation, I hypothesize that
removal of SYK signaling, and subsequent dampening of microglial activation, will blunt tau-mediated
neurological disease by promoting neuroprotective and anti-inflammatory functions in microglia. In Aim 1, I will
investigate a microglial-specific role for SYK in modulating tauopathy and associated neurodegeneration. In
Aim 2, I will study the mechanisms by which the loss of SYK specifically affects microglial activation to provide
further understanding of the role of SYK signaling in neurodegeneration. Finally, in Aim 3, I will evaluate if
genetically deleting microglial Syk offers an effective strategy to limit disease at a time point when PS19 mice
exhibit signs of tau pathology and cognitive deficits. Completion of the proposed studies will break new ground
in our understanding of the intracellular molecular mediators (i.e. SYK) that orchestrate immune responses in
primary tauopathy and will further reveal how microglia activation contributes to neurodegenerative disease
etiology. Moreover, this work is of potential translational significance as it will interrogate the therapeutic
efficacy of SYK-inhibiting treatment in limiting the progression of AD and FTD.

## Key facts

- **NIH application ID:** 10995481
- **Project number:** 1F31AG089911-01
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** Alexis Marie Johnson
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $38,001
- **Award type:** 1
- **Project period:** 2024-09-01 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10995481

## Citation

> US National Institutes of Health, RePORTER application 10995481, Exploring the Role of Microglia SYK Signaling in Tauopathy (1F31AG089911-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10995481. Licensed CC0.

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