# Conserved role of uric acid and purine metabolites in longevity and healthspan

> **NIH NIH F31** · BUCK INSTITUTE FOR RESEARCH ON AGING · 2020 · $29,520

## Abstract

PROJECT SUMMARY/ ABSTRACT
Uric acid builds up with both age and a nutrient-rich diet1-9. Elevated uric acid is associated with higher all-cause
mortality risk and aging-related diseases such as hypertension, dyslipidemia, type-2 diabetes, cardiovascular
disease, metabolic syndrome and gouty arthritis in clinical cohort studies. Elevated serum or urinary UA level in
humans is a consequence of the loss of the enzyme uricase, during evolution, further augmented by the
consumption of an enriched diet in humans, with hyperuricemia afflicting over 20% of the US population10,11.
Despite being a risk factor for increased morbidity, the genetic and mechanistic causes of increasing uric acid
levels are not well known. Tests of unknown genetic associations have previously been performed utilizing
several human cohorts to find genes associated with either serum uric acid levels or gout, but in vivo tests have
not been performed to validate these genes. This is primarily due to the lack of applicable animal models.
Therefore, we established a Drosophila melanogaster model using Uricase knockdown, which increases UA
levels. The inhibition of uricase led to both a diet-dependent shortening of lifespan and a buildup of UA
concretions. Genetic and pharmacological inhibition of insulin-like signaling (ILS) pathway genes reduced UA
load and concretion formation. Furthermore, a conserved role for the ILS in modulating UA was supported by
data showing that SNPs in the ILS genes IGFR1, AKT2, and FOXO3 are associated with regulating serum UA
levels or gout in humans. To identify other regulators of uric acid, I performed a Genome-Wide Association
Study (GWAS) of uric acid and upstream purine pathway metabolites in ~150 different fly strains from the DGRP
collection on two different diets. We validated 5 novel genes that modulate uric acid accumulation.
In Aim 1 I will examine the role of the ILS pathway which has been identified in human cohorts as a modulator
of uric acid. ILS is a well-conserved signaling cascade that is activated when Drosophila is fed a high protein
diet. I hypothesize that levels of uric acid are mediated through a multifaceted adjustment of purine homeostasis
acting through FOXO and downstream effects on ROS production. In Aim 2 I will characterize candidates from
a genetic screen that has uncovered novel modulators of purine metabolism in the Drosophila Genetic
Reference Panel (DGRP) collection of flies. I will characterize their role in hyperuricemia mediated concretion
formation, healthspan, and lifespan in our fly model. I will also collaborate with the Giacomini lab to determine if
human orthologs of candidate fly genes also modulate hyperuricemia in humans. My work will help better
understand how ILS and purine metabolism influence uric acid levels and lifespan, identifying therapeutic targets
to reduce human hyperuricemia-related pathologies.

## Key facts

- **NIH application ID:** 9977899
- **Project number:** 5F31AG062112-03
- **Recipient organization:** BUCK INSTITUTE FOR RESEARCH ON AGING
- **Principal Investigator:** Tyler Alan Unadkat Hilsabeck
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $29,520
- **Award type:** 5
- **Project period:** 2018-09-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9977899

## Citation

> US National Institutes of Health, RePORTER application 9977899, Conserved role of uric acid and purine metabolites in longevity and healthspan (5F31AG062112-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9977899. Licensed CC0.

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