Abstract
Purpose: :
To identify proteins expressed during nerve regeneration following lamellar flap surgery in murine corneas.
Methods: :
Hinged lamellar corneal flap was fashioned surgically in Thy1-YFP neurofluorescent mice (n=8). Corneas were harvested at 4 weeks and the flaps were separated from the bed. Two-dimensional electrophoresis was performed according to the carrier ampholine method of isoelectric focusing. Gels were scanned with a laser densitometer. The images were analyzed using Progenesis Same Spots software. Spot integrated density above background was expressed as a percentage of total density above background of all spots measured. Protein spots with >1.7 fold difference (p<0.05) were punched out and MALDI Mass spectrometric analysis was performed on the digest using Applied Biosystems Voyager DE Pro mass spectrometer in the linear mode.
Results: :
Eighteen protein spots showed >1.7 fold difference. Of these spots Calmodulin-like protein 3 showed the highest difference in expression (14.5 fold). Other proteins identified were Transgelin-2, Annexin A1, Annexin A2 and cytokeratins. The expression of calmodulin-like protein 3 was confirmed by qPCR.
Conclusions: :
Calcium sensor proteins like Calmodulin are abundantly expressed during corneal nerve regeneration. Calmodulin may play a role in during corneal nerve regeneration by regulating calcium signaling dependent secretion of neurotrophins.
Keywords: cornea: basic science • proteomics • regeneration