# REGULATION OF MITOCHONDRIAL QUALITY THROUGH MITOPHAGY IN ALZHEIMER'S DISEASE

> **NIH NIH R01** · RUTGERS, THE STATE UNIV OF N.J. · 2020 · $525,000

## Abstract

PROJECT SUMMARY
Alzheimer’s disease (AD) affects 50% of individuals over 85 years old, and the broad impact of AD is
devastating the aging population and their families—a health problem that is likely best addressed with early
intervention strategies. The earliest features of the highly prevalent AD have been linked to mitochondrial
abnormalities, including reduced energy production, reactive oxygen species generation, hypometabolism, and
altered mitochondrial dynamics and transport. Data support that AD patients display early bioenergetic and
metabolic disruptions prior to the emergence of any histopathological or clinical features. Thus, mitochondrial
deficits are likely early and critical for the onset and development of AD pathology. Mitochondrial quality
control, then, emerges as a central problem in AD and is a clear target point for early interference in disease.
How do neurons maintain high quality mitochondria? Mitophagy, a cargo-specific autophagy, constitutes a key
pathway of mitochondrial quality control that involves sequestration of aged or damaged mitochondria into
autophagosomes and subsequent degradation within lysosomes. We provided the first neuronal imaging
evidence showing unique features of Parkin-mediated mitophagy in live neurons. Our work further revealed
that Parkin-mediated mitophagy is robustly activated at early AD disease stages, but impaired clearance of
defective mitochondria is a result of lysosomal protease deficiency, which blocks degradation.
Mitochondria critical for neuronal communication are situated at the synapse. The disturbance of synaptic
mitochondria is a proposed early pathological event in AD. A distinctive feature of AD is the synaptic
accumulation of mitophagosomes—autophagosomes containing mitochondria. Since Parkin-mediated
mitophagy mainly occurs in the soma of neurons, the gap in our understanding of how the quality of synaptic
mitochondria is controlled, and whether synaptic mitochondrial deficits are attributed to mitophagy
dysregulation to trigger early synaptic failure in AD, must be addressed. Mitophagy controls mitochondrial
quality and quantity, and was recently proposed as an important mechanism regulating energy metabolism. A
long-standing question on the nature of the intersection of mitophagy and mitochondrial energetic activity in
neurons remains to be addressed. Our project is designed to: 1) establish a causative link between mitophagy
deficits and early synaptic pathology in a physiological AD model; 2) define mechanistic details of a strategy
that can rescue mitophagy deficiency and bioenergetic dysfunction in AD mice.
Our studies will advance understanding of a critical early step in AD pathogenesis. As such, our findings may
provide new molecular and pharmacological targets for treating AD and normal cognitive decline.

## Key facts

- **NIH application ID:** 9968456
- **Project number:** 5R01NS089737-07
- **Recipient organization:** RUTGERS, THE STATE UNIV OF N.J.
- **Principal Investigator:** Qian Cai
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $525,000
- **Award type:** 5
- **Project period:** 2014-09-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9968456

## Citation

> US National Institutes of Health, RePORTER application 9968456, REGULATION OF MITOCHONDRIAL QUALITY THROUGH MITOPHAGY IN ALZHEIMER'S DISEASE (5R01NS089737-07). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9968456. Licensed CC0.

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