2004 Fiscal Year Final Research Report Summary

Evaluation of retinal ganglion cell damage in rat glaucoma models by the dephosphorylation level of neurofilament

Research Project

Project/Area Number	15591846
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Ophthalmology
Research Institution	Teikyo University
Principal Investigator	SUZUKI Yasuyuki Teikyo University, School of Medicine, Professor, 医学部, 教授 (80196881)
Co-Investigator(Kenkyū-buntansha)	TOMIDOKORO Atsuo Tokyo University Graduate School of Medicine, Department of Ophthalmology, Lecture, 医学部附属病院, 講師 (80227628)
Project Period (FY)	2003 – 2004
Keywords	glaucoma / neurofilament / phosphorylation of heavy neurofilament subunit / retinal ganglion cell damage / rat glaucoma model / N-methyl-D-aspartate
Research Abstract	Early detection of retinal ganglion damage in animal glaucoma models has been difficult. Neurofilaments are major neuronal intermediate filaments expressed in most neurons. Dephosphorylation of heavy neurofilament subunit is reported to be involved in retinal ganglion cell damage. Evaluating the status of neurofilament in retinal ganglion cell may be a good indicator of early retinal ganglion cell damage. In this study, we evaluated the relationship between the status of neurofilament in retinal ganglion cell and retinal ganglion cell damage using rat models. First, a rat glaucoma model was constructed by cauterizing suprascleral veins. The retinal section was examined immunohistologically. The dephosphorylation level of heavy neurofilament subunit seemed correlated slightly with the retinal ganglion cell damage but not apparent. Next, the expression level of neurofilament was immunohistologically examined in another rat glaucoma model in which N-methyl-D-aspartate (NMDA) was injected into the vitreous cavity. The expression level of neurofilament was reduced in the eyes with retinal ganglion cell damage caused by NMDA injection. In order to study the dephosphorylation of heavy neurofilament subunit and the retinal ganglion cell damage further, the ELISA (enzyme-linked immunosorbent assay) for quantification of phosphorylated and unphosphorylated heavy neurofilament subunit was developed and applied to the rat glaucoma model. The ELISA system could evaluate the retinal ganglion cell damage quantitatively.