# Unraveling mechanisms of Niemann-Pick C neuropathology with mouse models

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2020 · $396,149

## Abstract

Abstract
The lysosomal storage diseases are a group of ~50 genetically distinct disorders that result from inherited
deficiencies of lysosomal hydrolytic activities or lipid transport. Among this group is Niemann-Pick type C
disease, an autosomal recessive disorder for which there is no effective treatment. Niemann-Pick C patients
exhibit a clinically heterogeneous phenotype characterized by severe, progressive neurodegeneration that is
usually fatal in childhood. Most cases are caused by loss-of-function mutations in the NPC1 gene, resulting in
disrupted intracellular trafficking of cholesterol and glycosphingolipids. Although disease-causing mutations
were identified almost two decades ago, it remains unknown how the resulting defects of lipid trafficking lead to
the severe neurological disease that is characteristic of this disorder. This lack of knowledge hinders the
identification of specific targets for developing disease-modifying therapies. The objective of this application is
to identify mechanisms leading to neurodegeneration and to define cellular pathways where interventions could
result in effective treatments. Our central hypothesis is that the disruption of cellular quality control pathways
caused by Npc1 deficiency underlies neurodegeneration. This hypothesis springs from our analysis of patient
fibroblasts and mice with a conditional null allele of the Npc1 gene generated in our lab. These studies and
results in the literature revealed impairments of cellular proteostasis, including abnormalities in autophagy, that
result in the accumulation of ubiquitinated proteins and fragmented mitochondria, particularly within neurons
and in CNS regions of selective vulnerability. Our studies also build on our preliminary data demonstrating
unexpected contributions of oligodendrocytes to neuronal degeneration in the mutant brain, suggesting
impaired support of neurons by glia. These findings are complemented by recent work characterizing a new
mouse model of disease that expresses Npc1 I1061T, the most prevalent disease-causing mutation.
Behavioral, histological, biochemical, cell biological and genetic approaches will be used to characterize
alterations in autophagy in Npc1 deficient neurons (Aim 1), establish the contribution of altered energy
metabolism to axonal pathology and neuron loss (Aim 2), and identify critical components of the machinery that
regulates degradation of Npc1 I1061T (Aim 3). These studies are expected to have an important positive
impact by defining mechanisms through which Npc1 deficiency leads to progressive neurodegeneration and by
identifying potential therapeutic targets. Furthermore, we expect that shared mechanisms mediate toxicity in
several lipid storage diseases, suggesting that advances here will impact our understanding and treatment
approaches to genetically distinct lysosomal storage disorders.

## Key facts

- **NIH application ID:** 10001003
- **Project number:** 5R01NS063967-12
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** ANDREW P LIEBERMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $396,149
- **Award type:** 5
- **Project period:** 2009-07-16 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10001003

## Citation

> US National Institutes of Health, RePORTER application 10001003, Unraveling mechanisms of Niemann-Pick C neuropathology with mouse models (5R01NS063967-12). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10001003. Licensed CC0.

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