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Principal Investigator: Hiroshi Nakagawa
Organization: COLUMBIA UNIVERSITY HEALTH SCIENCES
Fiscal Year: 2024
Award: $462,811
Funding agency: National Institute of Diabetes and Digestive and Kidney Diseases
Project summary
Esophageal stratified squamous epithelia comprise proliferative basal cells that undergo terminal differentiation
in the suprabasal cell layer. This homeostatic proliferation-differentiation gradient is regulated by Notch
signaling that is impaired in eosinophilic esophagitis (EoE), a chronic inflammatory disorder characterized by
mucosal eosinophilic infiltration, basal cell hyperplasia (BCH) and subepithelial fibrosis. BCH contributes to a
barrier defect that facilitates lamina propria remodeling, culminating in fibrotic esophageal strictures that
severely affect patients’ quality of life. While food allergen-activated immune cells and cytokines mediate EoE
pathogenesis, the relationship between esophageal epithelial biology and EoE pathogenesis remains elusive.
The ongoing project (R01-114436) has established the role of autophagy, a highly conserved cellular stress
response, as a fundamental mucosal defense mechanism in EoE. Epithelial autophagy activation involves
mitochondrial stress and reactive oxygen species (ROS) induced by proinflammatory EoE-relevant cytokines
such as IL-13, which in turn stimulate BCH. BCH features depletion of CD73+ basal cells and reciprocal
expansion of CD73- cells with low Notch activity, thereby limiting terminal differentiation. IL-13 promotes BCH
by inhibiting Notch while inducing ROS-mediated mitochondrial (mt) damage marked by mtDNA depletion.
Moreover, CD73- cells may maintain BCH via Notch-independent epithelial renewal. The overall objective in
this competing renewal application is to elucidate the nature of basal cell fate regulation in EoE pathogenesis.
The central hypothesis is that EoE-related inflammation influences basal cells’ activity to promote esophageal
tissue remodeling. This hypothesis has been formulated based upon strong preliminary data and publications
from the applicant’s laboratory and will be pursued through the following interrelated Specific Aims: (1) To
elucidate how autophagy activation limits BCH in the EoE inflammatory milieu; (2) To delineate the role of
mitochondrial damage in EoE-related BCH; (3) To unravel how Notch signaling protects against tissue
remodeling in EoE. The present proposal utilizes a robust murine model of EoE with squamous epithelia-
specific autophagy impairment, mtDNA depletion, or Notch inhibition with concurrent basal cell lineage tracing.
These approaches are coupled with ex vivo esophageal 3D organoids from EoE mice and patient biopsies to
define the mechanistic and functional role of autophagy and mitochondria in basal cell homeostasis. These
innovative studies will reveal novel insights into esophageal basal cell biology and tissue remodeling. With
genetically engineered mice, 3D organoids and patient biopsies, we will build a comprehensive platform for the
development and validation of novel translational applications related to EoE therapy (autophagy activation
and mitochondria-targeted antioxidants). These findings may have direct clinical impact in EoE, and potentially
other diseases (e.g. GERD) where autophagy, epithelial barrier defects and fibrosis have been implicated.
Terms: <3-D><3-Dimensional><3D><Acid Reflux><Active Oxygen><Affect><Antioxidants><Autophagocytosis><Autoregulation><Basal Cell><Basal Cell Hyperplasia><Biology><Biopsy><Body Tissues><CRISPR approach><CRISPR based approach><CRISPR method><CRISPR methodology><CRISPR technique><CRISPR technology><CRISPR tools><CRISPR-CAS-9><CRISPR-based method><CRISPR-based technique><CRISPR-based technology><CRISPR-based tool><CRISPR/CAS approach><CRISPR/Cas method><CRISPR/Cas technology><CRISPR/Cas9><CRISPR/Cas9 technology><Cas nuclease technology><Cell Body><Cell Communication and Signaling><Cell Fate Control><Cell Fate Regulation><Cell Lineage><Cell Signaling><Cells><Cellular Stress><Cellular Stress Response><Cellular biology><Chronic><Clinical><Clonal Expansion><Clustered Regularly Interspaced Short Palindromic Repeats approach><Clustered Regularly Interspaced Short Palindromic Repeats method><Clustered Regularly Interspaced Short Palindromic Repeats methodology><Clustered Regularly Interspaced Short Palindromic Repeats technique><Clustered Regularly Interspaced Short Palindromic Repeats technology><Coupled><Data><Defect><Defense Mechanisms><Desmosomes><Development><Disease><Disorder><Dose><Down-Regulation><Drug Targeting><Eosinophilic Esophagitis><Eosinophilic Infiltrate><Epithelium><Esophageal Diseases><Esophageal Disorder><Esophageal Reflux><Esophageal Stenosis><Esophageal Stricture><Esophageal Tissue><Esophagitis><Esophagus><Event><Fibrosis><Flow Cytofluorometries><Flow Cytofluorometry><Flow Cytometry><Flow Microfluorimetry><Flow Microfluorometry><GEM model><GEMM model><GERD><Gastro-oesophageal Reflux><Gastroesophageal Reflux><Gastroesophageal reflux disease><Generalized Growth><Genetic><Genetically Engineered Mouse><Growth><Homeostasis><Human><IL-13><IL13><Immune><Immunes><Impairment><Inflammation><Inflammatory><Interleukin-13><Intracellular Communication and Signaling><Knowledge><Label><Laboratories><Lamina Propria><Link><Macula Adherens><Mediating><Mediator><Mice><Mice Mammals><Microscopy><Mission><Mitochondria><Mitochondrial DNA><Modeling><Modern Man><Mucosa><Mucosal Tissue><Mucous Membrane><Murine><Mus><NIH><National Institutes of Health><Nature><Node of Bizzozero><Occluding Junctions><Organoids><Oxidative Stress><Oxygen Radicals><Pathogenesis><Patients><Peptic Esophagitis><Physiological Homeostasis><Pro-Oxidants><Proliferating><Proteins><Public Health><Publications><QOL><Quality of life><Radiation><Reactive Oxygen Species><Reflux Esophagitis><Research><Role><Scientific Publication><Signal Transduction><Signal Transduction Systems><Signaling><Spot Desmosome><Squamous Epithelium><Stratified Squamous Epithelium><Stress><Tamoxifen><Testing><Tight Junctions><Tissue Growth><Tissues><United States National Institutes of Health><Validation><Zonula Occludens><autophagy><biological signal transduction><cell biology><cell stress><cytokine><developmental><diseases of esophagus><drug detection><drug testing><esophagus disorder><experiment><experimental research><experimental study><experiments><flow cytophotometry><food allergen><genetically engineered mouse model><genetically engineered murine model><human disease><inflammatory environment><inflammatory milieu><innovate><innovation><innovative><insight><keratinocyte><mitochondrial><mouse model><mtDNA><murine model><notch><notch protein><notch receptors><novel><ontogeny><pharmacologic><postmitotic><psychological defense mechanism><self-renew><self-renewal><social role><three dimensional><translational applications><validations>