Purchase this article with an account.
Yuefang Zhou, Thomas Bennett, Alan Shiels; A Cell-Guidance Role for EPH Receptor A2 (EPHA2) in the Lens. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):2634.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
EPHA2 belongs to the ephrin receptor subfamily of protein-tyrosine kinases and has been implicated in regulating lens epithelial cell organization into meridional rows at the lens equator. In lens fiber cells, however, the role of EPHA2 and identity of its ephrin ligand(s) are unclear. Here, we investigate loss of EPHA2 function on lens fiber cell targeting to the sutures and determine the mRNA transcript distribution of EPHA2 and its putative ephrin-A ligands, EFNA1 and EFNA5, in the mouse lens
Mice lacking EPHA2 (Epha2-/-) were crossed with a transgenic reporter strain that constitutively ‘labels’ cell membranes with Td-tomato. Ex vivo whole lenses and formaldehyde-fixed-paraffin-embedded (FFPE) eye sections were imaged using fluorescence confocal microscopy and multiphoton microscopy techniques. Gene transcripts were localized in FFPE eye sections by in situ hybridization using RNAscope technology.
Suture formation in Epha2-/- lenses was dramatically disturbed, with posterior sutures disrupted more severely than anterior sutures. In addition, the cross-section radial pattern of Epha2-/- lens fiber cells was disorganized, particularly in young lenses. EPHA2 transcripts were most abundant in epithelial and fiber cells near the lens equator. EFNA1 transcripts were mostly restricted to the lens epithelium while EFNA5 transcripts were present in both the epithelium and peripheral fiber cells.
These studies suggest that EPHA2 is critical for precise guidance of lens fiber cells to the suture regions, particularly at the posterior pole. Further, EPHA2 may interact with both EFNA1 and EFNA5 in the lens epithelium; however, EFNA5 may act as the predominant ligand in lens fiber cells.<br />
This PDF is available to Subscribers Only