Epithelial cells often require polarization in two axes for their function, (1) ubiquitous apical-basal polarity and (2) a second axis within the plane of the epithelium, the latter called Planar Cell Polarity (PCP). Typical mammalian PCP examples are highlighted by the organization of the skin and many internal organs, e.g. the inner ear with its sensory cilia, and, importantly, also include directed cell migration during mammalian gastrulation and neural tube closure. In Drosophila, all adult cuticular structures show PCP features. The establishment of PCP in Drosophila serves as a paradigm to study PCP determination in mammalian development and human disease. PCP is coordinated by the activity of the Frizzled (Fz) receptor (with Wnt family members as their ligands) and its associated signaling cascade (Fz/PCP signaling), highly conserved throughout evolution. It not only regulates many aspects of cellular polarization, but also impacts coordinated and directed cell migration. Whereas the framework of PCP signaling is beginning to be established, its specific links to the regulatory feed into cell motility, cell migration, and associated biophysical changes in the responding cells remain largely unknown. The scope of this application is to establish the technology and analytical tools to allow an automated dissection and quantification of PCP regulated cell motility features at cell-biological levels. We will use the Drosophila eye as model system, as it provides unique advantages through its sophisticated genetic tools and available molecular markers. The goal is to establish imaging protocols and quantitative tools to allow the formulation of a biophysical model of PCP-regulated cell motility in the eye that then will serve as the paradigm for molecular disease oriented dissections of related processes. We will use a combination of Drosophila in vivo studies, a novel in vivo time-lapse imaging protocol for fly eye development, and mathematical quantitative analyses to define the critical parameters governed by PCP signaling that impact cell motility through, for example, junctional remodeling and associated cellular mechanic forces. Several components of PCP signaling and its associated downstream regulatory effectors are critically linked to neural tube closure defects (a prevalent child health development issue and frequent cause of late miscarriages or early embryonic death); in addition several other diseases, including cancer, and also stem cell biology features are linked to the molecules studied here. Thus, the information acquired in this application will not only advance our understanding of regulated cellular motility, but it will also be of medical relevance in many disease associated contexts.

Public Health Relevance

Wnt/Fz-planar cell polarity (PCP) signaling has been implicated in many developmental patterning contexts and also linked to several congenital diseases, ranging from hearing defects to cancer. This application addresses the mechanistic regulatory inputs of this signaling pathway to cell adhesion behavior and cell motility. The goal of this application is to generate and test a biophysical model of PCP regulated cell motility to serve as the paradigm and basis for associated disease features and several medical disorders.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21HD095043-02
Application #
9718208
Study Section
Development - 2 Study Section (DEV2)
Program Officer
Mukhopadhyay, Mahua
Project Start
2018-06-08
Project End
2020-05-31
Budget Start
2019-06-01
Budget End
2020-05-31
Support Year
2
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Icahn School of Medicine at Mount Sinai
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029