# NRF2 activation program in normal and immotile cilia

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 2024 · $576,280

## Abstract

Project summary/Abstract
Motile cilia are essential for lung defense, as evidenced by the genetic syndrome primary ciliary dyskinesia
(PCD). PCD is characterized by impaired motile cilia resulting in respiratory distress at birth, followed by chronic
sinopulmonary infection and bronchiectasis, which can lead to respiratory failure. There are no specific therapies
for PCD, in part because key pathways for motile cilia biogenesis and pathogenesis are not defined. PCD has
been linked to mutations in nearly 50 genes, which belong to three main groups: 1) Those encoding axonemal
dynein proteins - the motors necessary for cilia beating, 2) axonemal structural proteins, and 3) cytoplasmic
assembly and chaperon proteins. We have found that cells with variants in PCD genes have increased
expression of genes related to cell stress, including cytokines and interleukins. To better define the expression
profile of these cells, we used single cell RNA sequencing, and identified unique transcriptional changes in
ciliated cells from PCD patients that differed from those from healthy individuals. We identified activation of the
KEAP1-NRF2 pathway and differential gene expression of NRF2 target genes in PCD cells. The NRF2 pathway
is a major regulator of stress in cells. We also identified GSTA2 as a novel cilia axonemal protein that was
increased in PCD cells. GSTA2 is an enzyme that belongs to the glutathione pathway which is important for
protection from toxins and oxidative stress. This finding indicate that cilia have a dedicated glutathione pathway.
We hypothesize that GSTA2 plays a critical role in maintaining cilia function in health and disease, protecting
the ciliated cells from endogenous and exogenous factors. The exact function and mechanism of GSTA2 and
the NRF2 pathway in ciliated cells will be tested through the following Specific Aims: (1) Characterize and test
the requirement for a glutathione system in normal and PCD cilia; (2) Determine the role of the KEAP1-
NRF2 transcriptional program in the homeostasis of motile cilia and its activation in PCD. We will leverage
primary culture nasal cells from patients with mutations in different classes of PCD genes seen at our PCD clinic.
We will use advanced microscopy including expansion microscopy of native and tagged GSTA2 to determine
the localization of GSTA2. To define the role of the NRF2 pathway in ciliated cells and PCD, we will determine
the effects of pathway inhibition and activation in ciliated cells and measure changes in oxidative burden in cells.
We will use transcriptomic and proteomic analysis to investigate these novel candidates and define responses
to treatment. Finally, we will test these pathways using in vivo PCD models.
Findings generated through the proposed studies will provide fundamental understanding of motile cilia function
and provide novel therapeutic targets for PCD and motile cilia disease.

## Key facts

- **NIH application ID:** 10859698
- **Project number:** 1R01HL173490-01
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Amjad Horani
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $576,280
- **Award type:** 1
- **Project period:** 2024-06-15 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10859698

## Citation

> US National Institutes of Health, RePORTER application 10859698, NRF2 activation program in normal and immotile cilia (1R01HL173490-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10859698. Licensed CC0.

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