Abstract
Purpose: :
Integrins are heterodimeric extracellular matrix (ECM) receptors consisting of one α- and one β-integrin subunit which play a major role in cell proliferation, adhesion and migration. Our preliminary data indicated that αV-integrin and it's interacting β-subunits; β1, β5, β8 along with α-smooth muscle actin (αSMA) are upregulated 48hrs post cataract surgery in mice. This led us to hypothesize that αV-integrins play a significant role in lens EMT after injury and thus Posterior Capsular Opacification (PCO).
Methods: :
Mice lacking the αV-integrin subunit in their entire lens were created using a conditional knockout approach and at 3month of age subjected to lens fiber cell removal.
Results: :
Lenses lacking αV-integrin subunits are transparent until at least 5months of age. However, in comparison to wildtype lenses, αV-integrin null lenses show reduced lens epithelial cell (LEC) proliferation with little to no upregulation of αSMA expression 48hrs post surgery. Conversely, SMAD3 phosphorylation is similar in both wildtype and knockout remnant LECs up to 48hrs post surgery.
Conclusions: :
These results suggest that αV-integrin is not a vital player in lens development but is involved in the LEC EMT that leads to posterior capsular opacification.
Keywords: posterior capsular opacification (PCO) • cataract • EMT (epithelial mesenchymal transition)