# Aging dampens compensatory angiogenesis via downregulation of VEGF signaling in subcortical ischemic vascular dementia

> **NIH NIH R21** · MASSACHUSETTS GENERAL HOSPITAL · 2020 · $453,160

## Abstract

PROJECT SUMMARY/ABSTRACT
Subcortical ischemic vascular dementia (SIVD) is the most common subtype of vascular cognitive
impairment and dementia (VCID) syndrome that occurs with aging. SIVD is clinically defined as cognitive
decline with evidence of subcortical brain infarction. Patients with SIVD suffer from a vast amount of white
matter degeneration due to prolonged cerebral hypoperfusion caused by fibrohyalinosis of the medullary
artery, and often live with poor neurological function. Although the number of patients with SIVD is predicted
to increase with the aging population, to date there is no established treatment for this pathological
condition.
Since white matter dysfunction is a major characteristic of this disease, most of the mechanistic research in
SIVD has focused on oligodendrocyte/myelin damage and blood-brain barrier (BBB) damage within white
matter. Although the potential for white matter regeneration and recovery has not been widely studied,
compensatory responses for axonal regeneration along with oligodendrogenesis were observed in pre-
clinical animal models for SIVD. Therefore, it may be beneficial to recruit vascular remodeling as an
approach to support white matter repair/remodeling, which may alleviate the cognitive decline of SIVD
patients. Clinical studies indicate that restoring blood flow may improve cognitive function; however,
investigations into mechanisms of angiogenesis and vascular remodeling in SIVD are still lacking. This is
the major gap in knowledge that we seek to fill.
Vascular endothelial growth factor (VEGF) is heavily involved in regulating angiogenesis and vascular
(re)formation under both physiological and pathological conditions. However, its role in SIVD is unclear,
especially in the aged brain. Therefore, this exploratory study aims to reveal the roles of VEGF signaling in
angiogenic responses in cerebral white matter, by testing three hypotheses in a mouse model of SIVD: (i)
compensatory angiogenesis and vascular remodeling in SIVD mice is dampened by age, (ii) aged brains
have a lowered capacity for angiogenesis due to a decrease in VEGF signaling, and (iii) upregulating VEGF
signaling may support vascular repair/remodeling in aged SIVD mice.
For testing these hypotheses, we propose 2 integrated aims. Aim 1 will show that aged brain has a lowered
capacity for compensatory angiogenesis after cerebral hypoperfusion in mice, and Aim 2 will show that
upregulation of VEGF signaling rescues compensatory angiogenesis in aged hypoperfused-SIVD mice. This
exploratory study will provide novel insights into the mechanisms by which age-related decline in vascular
repair worsens white matter pathology in SIVD, and will provide a proof-of-concept that VEGF signaling is a
viable therapeutic target for SIVD.

## Key facts

- **NIH application ID:** 9916420
- **Project number:** 1R21AG066478-01
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Ken Arai
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $453,160
- **Award type:** 1
- **Project period:** 2020-02-01 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9916420

## Citation

> US National Institutes of Health, RePORTER application 9916420, Aging dampens compensatory angiogenesis via downregulation of VEGF signaling in subcortical ischemic vascular dementia (1R21AG066478-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9916420. Licensed CC0.

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