# Treating Alzheimer's disease by reducing brain insulin resistance with incretin receptor agonists

> **NIH NIH R01** · LOMA LINDA UNIVERSITY · 2020 · $193,430

## Abstract

Abstract
Using a novel ex vivo stimulation method allowing measurement of brain responses to insulin, our research
group established in 2012 a very common and profound abnormality in AD dementia cases closely associated
with accelerated cognitive decline. That abnormality is brain insulin resistance, which can be induced by many
early pathogenic factors in AD (including systemic insulin resistance) and can in turn cause or exacerbate
many of its later pathologic features and cognitive deficits. Brain insulin resistance thus appears to be a nodal
abnormality in AD, one whose alleviation may slow disease progression by exerting therapeutic effects on a
broad spectrum of pathologies and thereby slow cognitive decline in AD. If so, it may be possible to treat AD by
reducing brain insulin resistance.
Among the most promising agents available for reducing brain insulin resistance are drugs in a relatively new
class of antidiabetics known as incretin receptor agonists (IRAs), which are already known to reduce systemic
insulin resistance. IRAs activate one or both of the 2 major incretin receptors: glucagon-like peptide-1 receptor
(GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR). At least 3 IRAs cross the blood-
brain barrier, namely two GLP-1R agonists (exendin-4 and liraglutide) and a recently developed dual GLP-
1R/GIPR agonist (i.e., a dual IRA). Administered outside the CNS, then, these IRAs could reduce both
systemic and brain insulin resistance, in the latter case by activating GLP-1R and GIPR found in especially
vulnerable areas of AD cases, including the neocortex and hippocampal formation. Our preliminary data show
that IRAs applied ex vivo to the hippocampal formation from mild cognitive impairment (MCI) cases markedly
reduce insulin resistance in that brain structure and that the dual IRA has this effect even in advanced AD
dementia (ADd) cases.
Given these striking findings, we propose a preclinical evaluation of the hypothesis that AD can be treated by
reducing brain insulin resistance with IRAs. Our approach is innovative in testing candidate AD therapeutics for
their physiological effects on brain tissue from both an animal model of AD and from actual AD (and MCI)
cases. Our candidate therapeutics (exendin-4, liraglutide, and a dual IRA) will be tested on 3 target brain areas
in AD (lateral prefrontal cortex, posterior parietal cortex, and hippocampal formation) from (a)  wild-type and
APP/PS1 mice and (b) normal, MCI, and ADd cases. Aim 1 will determine the relative efficacy and
pharmacokinetics of the 3 IRA candidates in reducing brain insulin resistance and their ability to reach the
target brain areas via their normal subcutaneous route of administration. Aim 2 will test molecular mechanisms
by which these drugs reduce brain insulin resistance. Aim 3 will test if IRA-induced reductions in brain insulin
resistance are closely associated with reductions in a wide range of AD-related pathologies (e.g., elevated A...

## Key facts

- **NIH application ID:** 10229324
- **Project number:** 3R01AG057658-03S2
- **Recipient organization:** LOMA LINDA UNIVERSITY
- **Principal Investigator:** GREGORY M COLE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $193,430
- **Award type:** 3
- **Project period:** 2018-05-15 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10229324

## Citation

> US National Institutes of Health, RePORTER application 10229324, Treating Alzheimer's disease by reducing brain insulin resistance with incretin receptor agonists (3R01AG057658-03S2). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10229324. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*
