# Evaluating pexophagy as an early cellular marker of aging

> **NIH NIH R03** · LOUISIANA STATE UNIV A&M COL BATON ROUGE · 2021 · $72,115

## Abstract

Project Summary/Abstract
In animal species, aging occurs not only at an organismal level, but also at the level of cells.
Understanding cellular processes that change with age is important for clarifying the molecular basis
of age-related dysfunction and disease, and may point to robust biomarkers that can provide an
accurate measure of the biological age of an individual. Within cells, organelles execute complex
functions essential for cellular health and survival. How organelle homeostasis is regulated during
aging represents an important current topic in aging research, as it may provide insight into the
cellular events that drive age-related deterioration. In this proposal, we will investigate a new aspect
of organelle homeostasis in relation to aging. Namely, the proposed studies will focus on pexophagy,
or the autophagic destruction of peroxisomes, as an early event in somatic aging. Our lab has
generated a fluorescent pexophagy sensor to monitor peroxisome turnover in live Caenorhabditis
elegans. This reporter indicates that massive peroxisome turnover occurs in the C. elegans intestine
during early aging; notably, the pexophagy sensor easily distinguishes worms on their first day of
adulthood from those that are just a few days older. This raises an intriguing question: is pexophagy
an early biomarker of aging, and, if so, how does it relate to longevity? The proposed studies will
begin to address these questions through a series of experiments. To determine whether the timing
and/or scope of pexophagy scales with lifespan, the pexophagy sensor will be expressed in the
intestine of long-lived mutant strains and compared to wild-type animals at various time points during
aging. As a complementary approach to gauge the potential of pexophagy as a cellular biomarker of
aging, wild-type animals expressing the pexophagy sensor in the intestine will be segregated into two
populations during young adulthood: those with higher levels of pexophagy, and those with lower
levels of pexophagy. Subsequent lifespan analysis of the two populations will be performed to
determine whether this cellular marker is predictive of lifespan from an early point in adulthood.
Lastly, analysis of the pexophagy sensor will be extended to additional peroxisome-containing tissues
to clarify whether age-related changes to pexophagy are specific to the intestine or occur
synchronously in multiple tissues. Such analysis may suggest systemic control over this process, or
may instead hint at tissue-specific differences in aging at the cellular and molecular level. Collectively,
these studies will provide fundamental information on the cell biology of aging, and will conceptually
advance our understanding of age-dependent modifications to organelle biology.

## Key facts

- **NIH application ID:** 10176355
- **Project number:** 5R03AG067125-02
- **Recipient organization:** LOUISIANA STATE UNIV A&M COL BATON ROUGE
- **Principal Investigator:** Kenneth Adam Bohnert
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $72,115
- **Award type:** 5
- **Project period:** 2020-06-15 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10176355

## Citation

> US National Institutes of Health, RePORTER application 10176355, Evaluating pexophagy as an early cellular marker of aging (5R03AG067125-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10176355. Licensed CC0.

---

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