# Exploring the Relationship Between Tau Deposition and Neurovascular Health in Alzheimer's Disease

> **NIH NIH R21** · MASSACHUSETTS GENERAL HOSPITAL · 2020 · $462,000

## Abstract

Project Summary/Abstract
 There is a wealth of evidence indicating that vascular dysfunction is a prominent contributor to the
development of Alzheimer's disease (AD). Pathological changes in vessel hemodynamics, angiogenesis,
blood-brain barrier permeability and immune cell migration in AD have been attributed to the vasculotoxic
effects of amyloid-β (Aβ) plaques, and more recently, tau, with animal studies suggesting that Aβ and tau lead
to blood vessel abnormalities and blood-brain barrier breakdown. On the other hand, alterations in brain
perfusion are known to be present long before the clinical symptoms of AD develop, perhaps even preceding
amyloid-β (Aβ) plaque accumulation, tau deposition, and brain atrophy. It is critical to understand how vascular
dysfunction develops early in AD and how it relates to the classical AD biomarkers of Aβ and tau in order to
develop a reliable and accurate cerebrovascular biomarker of AD that can be used to identify AD in the early
asymptomatic stages of disease.
 Imaging studies have shown that capillary dysfunction correlates to the severity of AD and cerebral blood
flow (CBF) decreases in adults at risk for AD and in AD animal models. These findings support the importance
of quantification of vascular changes as it may provide a more comprehensive and possibly more sensitive
marker for detecting early AD changes. Recent studies in mice that develop either tangles or plaques
uncovered surprising evidence of morphological and functional alterations in the capillaries. In vivo two-photon
microscopy in these mice revealed tortuous capillaries with diminished blood flow, and the vessels showed
specific RNA signatures of angiogenesis and inflammation. Additional studies within the last year have
confirmed analogous microvascular and RNA changes in patients with AD, consistent with the hypothesis that
microvascular pathology is critical in mediating the development of AD. Thus, although it is commonly
assumed that reduced CBF is secondary to neuronal loss, we postulate that neuronal loss may be due to AD-
induced vascular abnormalities.
 In this exploratory study, we propose to investigate imaging biomarkers for cerebrovascular alterations, by
using cutting-edge perfusion magnetic resonance imaging (MRI) techniques, in individuals with known levels of
Aβ and tau protein as quantified through PET. The study design will build on our preliminary work using
advanced MRI techniques to probe cerebrovascular function together with high-sensitivity PET imaging
markers of Aβ and tau in patients with AD and cognitively healthy older adults at risk for developing AD. We
expect to identify the most promising cerebrovascular imaging biomarkers that are sensitive and specific to the
cerebrovascular alterations that occur in AD in its early stages. Once identified, these imaging markers can be
leveraged for defining the temporal sequence of events and relationships between abnormal protein deposition
and cerebrovascular impai...

## Key facts

- **NIH application ID:** 9975512
- **Project number:** 1R21AG067562-01
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Susie Yi Huang
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $462,000
- **Award type:** 1
- **Project period:** 2020-04-15 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9975512

## Citation

> US National Institutes of Health, RePORTER application 9975512, Exploring the Relationship Between Tau Deposition and Neurovascular Health in Alzheimer's Disease (1R21AG067562-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9975512. Licensed CC0.

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