# Role of Microglia in Cerebral Small Vessel Disease (CSVD)/Vascular Cognitive Impairment (VCI)

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 2024 · $591,839

## Abstract

PROJECT SUMMARY: Microglia, the brain’s resident immune cells, are implicated in the pathophysiology of
chronic ischemic cerebral small vessel disease (CSVD) and vascular cognitive impairment (VCI), a clinically
important cause of dementia that preferentially affects white matter (WM). Colony stimulating factor 1 receptor
(CSF1R) is a key regulator of myeloid lineage cells. Genetic loss of CSF1R blocks the normal population of
resident microglia and systemic treatment with CSF1R antagonists such as PLX5622 results in a marked
depletion of microglia in the CNS. Here we propose to evaluate the role of microglia and CSF1R signaling
in a novel rodent model of CSVD/VCI developed in the laboratory of our colleague Dr. Edith Hamel
(McGill University). Mice overexpressing transforming growth factor-beta1 (TGFOE) and fed a high cholesterol
diet (HCD) display impaired cerebrovascular reactivity, diffuse leukoencephalopathy, and cognitive dysfunction
that resembles human CSVD/VCI. We will first assess effects of TGFOE and HCD on regional and cell type
specific gene expression in microglia and other myeloid cells using single cell RNA sequencing. Next we will
determine if treatment with PLX5622 influences neurological, neuroimaging, and/or neurovascular
outcomes in TGFOE mice (+/-HCD). We will assess longitudinal WM integrity outcomes using state-of-
the-art 14 Tesla MRI with diffusion tensor imaging (DTI) and quantitative tractography. We will also use
sophisticated assessments of resting-state functional connectivity (optical imaging of intrinsic signals) and
neurocognition. Furthermore, we will perform longitudinal 2-photon brain imaging studies to track changes in
the cerebrovasculature during critical periods of CSVD/ VCI disease initiation and progression. We will
confirm the microglia-specific nature of our findings using an orthogonal genetic approach by crossing
TGFOE mice with a Csf1rflox/flox : HexbCreERT2 bigenic line that exhibits stable, microglia-specific knockdown of
Csf1r. We will then feed the trigenic TGFOE : Csf1rflox/flox : HexbCreERT2 line HCD and carry out the same
comprehensive set of longitudinal parameters described above. We anticipate that both pharmacologic
depletion of microglia and genetic deletion of CSF1R signaling specifically in microglia will attenuate WM
inflammation and injury and result in improvement in multiple outcome parameters. In aim 3 we will collaborate
with our colleagues in Radiology to use a novel CSF1R radioligand to carry out longitudinal positron
emission tomography (PET) on TGFOE mice (+/-HCD) at multiple time points during disease initiation and
progression. This will provide critical information on temporal and spatial in vivo expression patterns of
CSF1R in the context of CSVD/VCI and generate foundational data for a novel biomarker for
neuroinflammation that can be readily scaled up from mouse to humans. Overall, this microglia- and CSF1R
signaling-targeted, WM-centric approach will provide important ...

## Key facts

- **NIH application ID:** 10862730
- **Project number:** 5R01NS124627-03
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** JONATHAN R WEINSTEIN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $591,839
- **Award type:** 5
- **Project period:** 2022-07-15 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10862730

## Citation

> US National Institutes of Health, RePORTER application 10862730, Role of Microglia in Cerebral Small Vessel Disease (CSVD)/Vascular Cognitive Impairment (VCI) (5R01NS124627-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10862730. Licensed CC0.

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