The Eye Lens
The ocular lens is a transparent, ellipsoid organ in the front of the eye that is responsible for the fine focusing of light onto the retina in order to transmit a clear image. Thus, it is essential for the lens to remain transparent throughout your lifetime. The lens presents a unique opportunity to study cell aging, morphogenesis and migration and cell-cell communication all in one tissue.
The lens consists of a monolayer of epithelial cells at the anterior surface (colored cells) and a bulk mass of elongated lens fibers (white cells) that extend from the anterior to posterior poles. The entire lens is encapsulated by a thin collagenous basement membrane called the lens capsule.
Anterior epithelial cells are quiescent and do not proliferate. These cells (pink box) are cobblestone in shape, and their main function is to maintain the underlying fiber cells.
Lifelong lens growth relies on the proliferation, migration and differentiation of equatorial epithelial cells in the germinative zone. Equatorial epithelial cells undergo a remarkable morphogenesis to transform from randomly organized cuboidal cells (orange) into organized rows with hexagon cell shape (green).
If we view the lens fibers in cross section (blue box), we observe that the organization and hexagon cell shape are retained in fiber cells. New layers of lens fiber cells are continuous added onto previous generations of fibers, and the lens grows in concentric shells. Tight fiber cell packing to minimize intercellular space is crucial for maintaining lens transparency.
Our lab aims to understand the mechanisms for establishing and maintaining lifelong homeostasis and transparency in the eye lens. While decades of studies have identified the genes required to make a transparent lens, there remain many unanswered questions about basic lens cell biology that hinder the development pharmaceuticals to prevent or delay age-related lens pathologies, including cataracts and presbyopia.
Please click on the links below for more info on our areas of research.
Cataracts and Eph-ephrin Bidirectional Signaling
Presbyopia and Complex Lens Fiber Cell Morphology