The Relationship Of UPR And GLAST In Retinal Müller Cell After The Optic Nerve Injury

Optical nerves injury caused by traumatic, glaucoma are major occoecatio diseases. Retinal ganglion cells (RGC) and their axons are belongs to the central nervous system (CNS), if they damaged, they don't regenerate. So the protection of RGC is always an important problem of research on ophthalmology. Retinal Müller cells maintain the concentration of glutamic (Glu) which around RGC by L - glutamate/L - aspartic acid transport body (GLAST), to protect RGC to alive.Unfolded protein reaction (UPR) is cells areas in external stimuli, first under performance for the endoplasmic reticulum(ER) there are a lot of not fold protein and protein accumulation error folding, raising a series of cells reaction. There are three related factors, need inositol enzyme 1 (IRE-1), doublestranded RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor 6 (ATF -6).Objective:1. To build a successful model of rat's optic nerve crushed.2. After the optic nerve injury, study if UPR exist in retinal Müller cells.3. Study the relationship between UPR and GLAST. Methods:1. To build rat's optic nerve crushed model, using HE dyeing, TUNEL dyeing to improve the model successful.2. Use immune fluorescence double marking to observe the expression of UPR associated factor IRE -1 and Müller cells'marker GS.3. Using immunohistochemistry, immune fluorescence double marking, western - blotting to observe the expression and relationship of UPR related factors IRE - 1 and GLAST.Results:1. HE dyeing results show that in control group, the number of RGC is 41.23±2.34, after the optic nerve injury, at each time point ,the number of RGC is reduced, until 5d,the number is31.20±2.35(P<0.05),7d ,the number is 27.50±1.51(P<0.05).TUNEL dyeing results show that normal rats'RGC is1.5±0.5, at 12h, 1d, 3d, 5d, there is a growing trend, and at 5d to the peak(29.15±2.50,P<0.05), at 7d reduced(13.55±2.15,P<0.05).All above show that, optic nerve crushed model can actually caused the optic nerve injury, and reduce the number of RGC by the way of apoptosis.2. After optic nerve crush injury, IRE-1 and GS immunofluorescence double labeling showed that, in the normal group, IRE-1 in a slight expression of full-layer of retina,, IRE-1's expression significantly increased at 1d, and co-express with GS in the internal limiting membrane, nerve fiber layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, the external membrane It indicates that Müller cells occurred UPR.3. After optic nerve crush injury, immunofluorescence double labeling showed that IRE-1 in the ganglion cell layer, inner nuclear layer and outer nuclear layer were abundantly expressed. Western-blotting results show that IRE-1 and GLAST co-express in retinal Müller cells ascend in the common trend and reach the summit one day after surgery, then drop sharply in the seventh day. All of these indicate that the UPR in Müller cells regulate GLAST.Conclusion:1 After optic nerve injury,UPR exists in retinal Müller cells.2. There was relationship between the IRE-1 and GLAST in trend changes after optic nerve injured which suggests UPR may be one cause of the regulation of GLAST changes.