# Optimized Circadian Rhythms for the Prevention of Alzheimer's Disease

> **NIH NIH RF1** · SALK INSTITUTE FOR BIOLOGICAL STUDIES · 2020 · $3,046,010

## Abstract

Geroscience hypothesis posits that aging itself is the underlying major risk factor for 
 age-related chronic diseases, including Alzheimer's Disease (AD); therefore, delaying 
aging delays disease, including AD. This proposal will examine the reciprocal relationship 
between circadian rhythm disruption (CRD) and AD pathology. Circadian rhythms, which are 
intimately interlinked with cellular metabolism, orchestrate the coordinated expression 
and function of multiple pathways that support normal cellular function and repair in both neural 
and peripheral tissues. Circadian rhythms deteriorate with aging, and Alzheimer's patients show 
disrupted circadian rhythm. However, the causal role of CRD for AD is not clear. The proposal will 
assess the relationship between circadian rhythm disruption and AD pathology, will test whether 
improvement in circadian rhythms delay the onset and progression of AD. and will attempt to 
identify underlying molecular mechanisms.
Well-characterized Drosophila melanogaster (fruit fly) models of AD with Drosophila genetic tools 
will be used to test the impact of genetic or environmental CRD on the onset and severity of the 
multiorgan functional decline in AD. One feature of CRD is the lack of feeding consolidation to 
daylight hours in diurnal animals. To restore aspects of circadian rhythm in older flies, animals 
will be subject to time-restricted feeding (TRF) in which food is provided to flies only during the 
12 h day time. TRF does not reduce daily caloric intake and imparts a molecular signature that is 
distinct from that under caloric restriction. Disease onset and severity will be assessed in TRF, 
and ad lib fed (ALF) flies to determine if TRF is an effective behavioral intervention for AD. To 
test the molecular pathways mediating the opposite effects of CRD and TRF on AD pathologies, 
time-series transcriptomes from these flies will be analyzed to find candidate pathways. The 
functional significance of these pathways will be tested by expressing genetic gain of function and 
loss of function alleles in AD flies. Our novel in vivo genetic-transgenic Drosophila disease 
model coupled with ultrastructural, functional, metabolic, and transcriptome techniques will 
generate unbiased insights into the mechanistic basis of accelerated aging in production of AD. 
Successful completion of this project will provide a deeper molecular understanding of the 
interaction between circadian rhythm and genetic risk of AD. Additionally, this research 
will assess the efficacy of a behavioral intervention that would have a high potential for 
adoption in humans.

## Key facts

- **NIH application ID:** 10037591
- **Project number:** 1RF1AG068550-01
- **Recipient organization:** SALK INSTITUTE FOR BIOLOGICAL STUDIES
- **Principal Investigator:** Girish C. Melkani
- **Activity code:** RF1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $3,046,010
- **Award type:** 1
- **Project period:** 2020-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10037591

## Citation

> US National Institutes of Health, RePORTER application 10037591, Optimized Circadian Rhythms for the Prevention of Alzheimer's Disease (1RF1AG068550-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10037591. Licensed CC0.

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