Abstract
Abstract: :
Purpose: To study the expression of heat shock protein 25 (HSP 25) in the retinas of adult rats after optic nerve crush Methods: Adult Lewis albino rats, 50-60-day-old, recieved optic nerve crush injury on the right eye. The left eyes were used as control . Animals were euthanized at 1, 3, 5 , 7, 10, 14 or 28 days after crush injury, and their eyes were enucleated. Retinal HSP 25 was examined by Western blotting and immunohistochemistry. TUNEL was also performed on retinal sections. The number of retinal ganglion cells (RGC) was counted on flat preparations of retinas at various times after the crush injury. Results: Western blotting analysis showed a significant increase in HSP 25 content after optic nerve crush reaching a peak at 7 days after injury. Immunocytochemical study revealed the number of HSP 25 positive cells increased in the retina after injury, mainly localized in the inner nuclear cell layer (INL) and the retinal ganglion cell layer (RGCL). RGC counts showed significant losses at 7 day and onward when compared with normal controls. Between 7 and 10 days, abundant TUNEL positive cells were also found in the INL and RGCL. Conclusion: HSP 25 protein was up-regulated in the retina after optic nerve crush and its up-regulation may be closely linked to RGC death.
Keywords: 415 ganglion cells • 343 chaperones • 608 trauma