Lens epithelial cells are the parental cells responsible for growth and development of the transparent ocular lens. Many elegant investigations into their biology have focused on the factors that initiate and regulate lens epithelial cell differentiation. Because they serve key transport and cell maintenance functions throughout life, and are the primary source of metabolic activity in the lens, mechanisms to maintain lens epithelial cell integrity and survival are critical for lens transparency. The molecular chaperones α-crystallins are abundant proteins synthesized in the differentiated lens fiber cell cytoplasm. However, their expression in lens epithelial cells has only been appreciated very recently. Besides their important roles in the refractive and light focusing properties of the lens, α-crystallins have been implicated in a number of non-refractive pathways including those involving stress response, apoptosis and cell survival. The most convincing evidence for their importance in the lens epithelium has been shown by studies on the properties of lens epithelial cells from αA and αB-crystallin gene knockout mice. The effective combination of genetics, cell and molecular biology possible with lens epithelial cells is attracting an increasing number of researchers focused on understanding how lens epithelial cells coordinate survival, proliferation and differentiation.
Cell facts• Lens epithelial cells are responsible for the growth and development of the entire ocular lens • Lens development is controlled by cell cycle regulators, signaling molecules and growth factors such as FGF • Lens epithelial cells express members of the small heat shock protein family of molecular chaperones, αA and βB-crystallins, the first crystallins to be expressed during lens development • α-Crystallins likely protect lens epithelial cells from environmental stress throughout life, and thus may delay the onset of age-related cataract • Lens epithelial cell proliferation is deregulated in posterior capsule opacification leading to secondary cataract, a complication in up to 50% of cataract surgeries Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers