The transient receptor potential (TRP) superfamily of non-selective cation channels play critical roles in diverse physiological processes including the perception of light, temperature, pressure, and pain. In previous genetic studies, we have discovered that mutation of a member of the melastatin-related TRP-channels (TRPM3) underlies an inherited form of pediatric cataract that is variably associated with glaucoma and anterior segment defects. In this proposal, we will investigate the role of TRPM3 in lens development and cataract pathobiology using gene-edited mice and cell-lines by addressing three specific aims.
In aim -1, we will characterize lens TRP-channel transcript splice-variants by means of RNA deep-sequencing and the calcium channel properties of lens TRPM3 isoforms using fluorometric calcium imaging techniques.
In aim -2, we will characterize the effects of TRPM3 dysfunction and deficiency on lens cation status, water content, and calcium influx properties using a combination of atomic absorption spectrometry and calcium imaging techniques.
In aim -3, we will characterize the effects of TRPM3 dysfunction and deficiency on lens morphogenesis and gene expression using differential immuno-fluorescence microscopy and RNA deep-sequencing techniques, respectively. Results from these studies will provide new insights regarding the role of TRP-channels in lens growth, cation homeostasis, calcium dynamics, and pathophysiology within the context of pediatric cataract ? a clinically important risk factor for lifelong visual impairment. More broadly, these studies will contribute to an understanding of TRP-channel function and dysfunction in other eye tissues (e.g., iris, ciliary body) and diseases (e.g., glaucoma, anterior eye defects), respectively.

Public Health Relevance

Despite surgical treatment, pediatric cataract is an important cause of impaired form-vision development and of lifelong visual impairment. We have discovered a novel genetic cause of pediatric cataract that elevates cytoplasmic calcium in the lens - a long established symptom of age-related cataract. This research aims to advance understanding of the molecular and cellular mechanisms that lead to cataract and contribute to the discovery of non-surgical treatments and/or preventative interventions for cataract.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
1R01EY028899-01A1
Application #
9659875
Study Section
Biology of the Visual System Study Section (BVS)
Program Officer
Araj, Houmam H
Project Start
2019-02-01
Project End
2024-01-31
Budget Start
2019-02-01
Budget End
2020-01-31
Support Year
1
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Washington University
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130