New map of eye proteins
A new mapping of proteins in the eye opens the door for new treatments of eye diseases in the future.
The extracellular matrix, ECM, offers a protective shelter for cells and provides signaling paths important for cell to cell communication. ECM consists of basement membranes, BM, and interstitial matrix. BMs provide mechanical support for parenchymal cells, influence cell proliferation, survival, migration and differentiation. They are also important for tissue integrity. Laminins are the major non-collagenous component of BMs. Cell-ECM interactions, mediated by receptors, are indispensable during embryonic development, wound healing, remodeling and homeostasis of tissues. The integrins are the major cell-adhesion receptors.
Berit Byström states that the expression of alpha11 integrin chain in the cornea is of great interest, as it is part of the alpha11beta1 integrin receptor for collagen type I, the predominant component of the corneal stroma. The aims of her research was to thoroughly characterize the ECM in the developing and adult human eye, with particular focus on the cornea, LM and alpha11 integrin chains, and to examine alpha11 integrin chain in an animal model of corneal wound healing and remodeling.
Human fetal eyes , 9-20 weeks of gestation, and adult human corneas with different diagnosis were treated for immunohistochemistry with specific antibodies against LM and alpha11 integrin chains. Normal and knockout mice were treated with laser surgery to create a deep wound in the corneal stroma. The wound healing process was followed at different time points. The cellular source of alpha11 integrin chain was studied in cell cultures.
In the fetal eyes , the BM of the corneal epithelium, the Descemet’s membrane and the Bruch’s membrane each had their specific combinations of LM chains and time line of development, whereas the lens capsule and the internal limiting membrane showed constant LM chain patterns.
The distinct spatial and temporal patterns of distribution for alpha11 integrin and each of the LM chains suggest that they play an important role in human ocular differentiation. The selectively affected LM composition and the novel expression of alpha11 integrin chain in scarred keratoconus corneas as well as the pathologic healing in ko mice, indicate that alpha11 integrin and LM chains also play an important role in the process of corneal healing, remodeling and scarring and might participate in the pathogenesis of corneal disease. This knowledge is of practical importance for future topical therapeutic agents capable of modulating the corneal wound healing processes, according to Berit Byström.
