# Novel small molecules targeting brain phospholipid dysregulation in AD

> **NIH VA I01** · JAMES J PETERS VA  MEDICAL CENTER · 2021 · —

## Abstract

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease of aging, with one in eight older
Americans diagnosed with AD. It is also the most frequently diagnosed type of dementia within the Veterans
Affairs (VA) Medical System, and one of the major causes of morbidity and mortality among veterans. The
Department of VA estimates that 600,000 veterans suffered from severe AD and other forms of dementia in
2000, and this number is increased significantly today, because of the increasing proportion of older veterans
and the increased prevalence of dementia in veterans that suffer from traumatic brain injury (TBI) and/or post-
traumatic stress disorder (PTSD). Therefore, AD research studies are particularly important to veterans.
Currently no treatment is available to slow or stop AD. There is a great need for identification of more
efficacious therapies for AD, which is among the priorities of VA RR&D research directions.
 Synaptojanin 1 (synj1), the main phosphoinositol biphosphate phosphatase [PIP2 degrading enzyme] in the
brain and synapses, has been recently linked to AD. More importantly, we have demonstrated that synj1
regulates lysosomal clearance of Aβ and that the increased synj1 expression links to ApoE4-induced
phospholipid dysregulation and cognitive deficits. Down-regulation of synj1 promotes Aβ clearance, reduces
tau hyper-phosphorylation and ameliorates ApoE4 pathogenic effects. Subsequently, reduction of synj1
attenuates AD-related pathological changes and behavioral deficits in AD mouse models. These findings
suggest that reduction of synj1 has potential therapeutic benefits for AD. Our initial screening of 89 top hits out
of a library of compounds (~3,600 small molecules) with the potential to reduce synj1 protein levels using “The
Connectivity Map”, identified a FDA-approved drug nimodpine with synj1- and Aβ-lowering effects in both wild-
type and ApoE4 neuronal cultures. Further administration of nimodipine for one month, is capable of reducing
brain content of synj1 and Aβ, as well as improving cognitive functions in an AD transgenic mouse model and
an ApoE4 KI mouse model. However, chronic administration of nimodipine failed to reduce brain Aβ42 levels
(particularly insoluble fractions), or to improve cognitive function. Our data suggest that the effects of
nimodipine on reduction of synj1 expression are independent of its inhibitory effects on calcium channel
activities. We then designed and synthesized first-generation nimodipine structural analogs using medicinal
chemistry to reduce its calcium channel activity, and identified a novel compound, SynaptoCpd#9, with
attenuated inhibition of calcium channels and increased potency against synj1 and Aβ42 compared to
nimodipine both in vitro and in vivo. Oral administration of SynaptoCpd#9 in APPSwe/PS1E9 and ApoE4 mice
for 3-6 months improved cognitive function and reduced AD-related pathologies (insoluble Aβ42 particularly).
RNA-sequencing and qPCR studies of treat...

## Key facts

- **NIH application ID:** 10070523
- **Project number:** 5I01RX002290-04
- **Recipient organization:** JAMES J PETERS VA  MEDICAL CENTER
- **Principal Investigator:** Dongming Cai
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2017-12-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10070523

## Citation

> US National Institutes of Health, RePORTER application 10070523, Novel small molecules targeting brain phospholipid dysregulation in AD (5I01RX002290-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10070523. Licensed CC0.

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