Abstract
Purpose: :
To determine whether penetration by iron objects results in changes in phosphoinositol profile for the bovine cornea. To determine whether iron object penetration and length of exposure time results in predictable changes in phosphoinositol metabolizing proteins in bovine cornea.
Methods: :
Enucleated bovine eyes (n=60) were used for exposure to penetrating iron objects of various shapes. Eyes were subjected to Fluorescein staining to confirm corneal epithelial integrity prior to performing experiments. Laemellar dissection techniques were employed to isolate layers of the cornea for exposure. Excised cornea was subjected to protein and lipid extraction. Lipid extraction was performed using Bligh and Dyer method. Protein amount was determined by spectrophotometry and protein profile was determined using SDS-PAGE analysis. Identity of a unique protein band after 24 hour exposure to iron was determined using a LCQ Deca XP mass spectrometer. Analyses of phosphoinositol lipids were carried out using negative mode precursor ion scan (product m/z 241 and collision energy of 45 V) using a TSQ Access Quantum Max mass spectrometer using infusion. This research adhered to ARVO statement for use of animals in research.
Results: :
Iron object penetration and 24 hour exposure resulted in specific degradation of Phosphoinositol bisphosphatase beta 2 variant (PLCB_2) into a 36KDa band. Commensurate with degradation of PLCB_2, 24 hour iron treated cornea resulted in altered levels of phosphoinositols. We found epithelial layer impaction and incubation necessary for specific degradation of PLCB_2.
Conclusions: :
Exposure of corneal epithelial layer to iron objects results in changes in corneal levels of phosphoinositol lipids and Phosphoinositol bisphosphatase beta 2 variant protein.
Keywords: cornea: basic science • protein structure/function • lipids