| Objective: Optic nerve injury is a common causing blindness eye diseasefeatured on the fall of visual function. It severely reduces the patients’ lifequality, but there is a lack of effective drug treatment. Optic never iscomposed of axons of retinal ganglion cells (RGCs), and the death of opticnerve ganglion cell is the common cause of optic nerve injury diseases, suchas glaucoma, traumatic optic neuropathy, and intracranial pressure, andresearch shows that an important way of apoptosis after RGCs damage isdeath. Therefore, the choice of effective drugs that can inhibit optic ganglioncell injury death and promote regeneration and repair is crucial.Minocycline(MC) may play a neuroprotective role through a variety ofresistance to apoptosis, excessive activation of glial cells, anti-neuroinflammatory pathway, and its also an effective neuroprotective agent.However, the function and mechanism of minocycline for resisting death ofafter optic nerve injury, resisting excessive activation of glial cells apoptosis,and promoting nerve repair is not clear. Apoptosis inducing factor (AIF) is themain apoptosis protein. Glial fibrillary acidic protein (GFAP) is the markerprotein of glial cells that can be activated reactive glial cells. This study madethe model of rat optic nerve injury. Compared with the observation group byintraperitoneal injection of minocycline, the experimental group observed themorphological chances of the retina under the light microscope, and theexpression level of immunohistochemestry semiquantitative detection ofretinal tissue AIF and GFAP. It explores the repair function of retinal nerveregeneration after optic nerve injury in perfect mildew and influence on AIF,GFAP expression and provides the basis for the treatment of optic nerveinjury.Methods:80healthy, clean SD rats (male and female is not restricted), weight200±20g. Divide them randomly into four groups: normal group, shaminjury group (exposed the right optic nerve only), treatment group (underwentoptic nerve crush+45mg/kg minocycline injection intraperitoneal injection of1/d,to the observation point) and the control group (line of optic nerve injury+45mg/kg minocycline injection intraperitoneal injection of1/d, to theobservation point), with20rats in each group. Take5rats randomly fromeach group according to four pixels1,3,7,14d after injury, fix cardiacperfusion, remove right eye and eliminate superfluous organization, then fixrentinal tissue slices. Observe the morphological changes after HE staining inretinal tissue under light microscope, and the expression changes of retinaafter immunohistochemistry stain of AIF and GFAP. Detect the averageoptical density value AOD of AIF and GFAP in the immunohistochemicalstaining retinal tissue by using computer image analysis, and express antigenthrough immunoreactive staining AOD. The higher AOD is, the more positiveit is. Analyze it with SPSS13.0statistical software, and express the resultswith mean±standard deviation. Use single factor analysis of variance andSNK-t test. P<0.005had significant difference.Results:1The results of HE retina in each group. The normal group and the shaminjury group: there is no significant difference in retinal tissue structure ofeach time point, retinal ganglion cells are banded arrangement, and there is noedema and necrosis.Control group: as injury time goes by, retinal tissuestructure of rats becomes sparse significantly. Results of treatment group: theinjury degree of rats retinal tissue in each time point is lower than those in thecontrol group, the retinal tissue is clear, the retinal ganglion cells are arrangedneatly, but the edema and necrosis are not decreased obviously.2The results of AIF, GFAP immunohistochemical staining andsemi-quantitative.2.1AIF results: the positive expression of AIF immune is brown in thecytoplasm, and it can be partly expressed in the cell nucleus. The normalgroup and the sham injury group express slightly, and there is no significant difference in time point; the control group1d shows positive expression,3dand7d are continuously increased, damaged peaks at7d, and damage14d isdecreased obviously to1d level;1d,3d,7d and14d in treatment group arelower than those in the control group.The results of Immunohistochemical semi-quantitative detection: there isno significant difference(P>0.05)of semi-quantitative detection of averageoptical density(AOD) between normal group and sham injury group, andnormal group1d AOD is0.165±0.047; control group1d,3d,7d and14dAOD are0.193±0.046、0.328±0.034、0.517±0.065、0.264±0.039each timepoint compared with normal group difference has statistically significant (P <0.05), and the they are higher higher than that in the normal group; treatmentgroup1d,3d,7d and14d AOD are0.184±0.018、0.239±0.024、0.287±0.028、0.189±0.009compared with normal group the difference hasstatistically significant (P <0.05), and they are higher than normal group;Each time point compared with control group and treatment group hasstatistically significant difference (P <0.05), and each time point AOD of thetreatment group is lower than that in the control group.2.2GFAP results: the immune positive expression of GFAP is brown, andcan be located in the retinal inner limiting membrane in the externalmembrane between each layer. The normal group and the sham injury groupare weakly positive, and each time point has no obvious change; the controlgroup1d is weakly positive,3d increases obviously than that in normal group,7d arrives at peak,14d is close to normal level; the treatment group is lowerthan those in the control group, except14d the treatment group is higher thanthat in the control group,but3d、7d and14d significantly higher than thanthat in the normal group.The results of Immunohistochemical semiquantitative detection:between the normal group and sham injury group the semiquantitativedetection of average optical density (AOD) at each point in time has notstatistical significance difference (P>0.05),the normal group1d AOD is0.178±0.085; in3d、7d the Control group（the AOD are0.328±0.034、 0.484±0.025) and normal group(the AOD are0.168±0.013、0.182±0.085)compared differences had statistical significance (P <0.05), the two timepoints AOD in the control group were higher than that in normal group; in3d,7d and14d the treatment group (the AOD are0.272±0.034、0.342±0.046、0.259±0.039) and control group (the AOD are0.328±0.034、0.484±0.025、0.194±0.025) compared differences had statistical significance (P <0.05), in3d,7d the experimental group was lower than that in the control group, in14dis higher than that in the control group; in3d,7d and14d the treatmentgroup was statistically significant difference were observed in the AODcompared with normal group (P <0.05), and the treatment group was higherthan that in normal group.Conclusions:1Retinal tissue injury degree decrease obviously after applyingminocycline, compared with applying physiological saline group(controlgroup), which explains that minocycline has protective effect of retina onoptic nerve injury.2Compared with applying physiological saline group, AIF expressionlevel in retinal tissue of each time point after applying minocycline decreases,which proves that minocycline could restrain the AIF expression in retinaltissue after optic nerve injury.3Compared with saline group,In optic nerve injury early the GFAPexpression level after applying minocycline is weaker, and the late is strongerthan saline group, which proves that minocycline could restrain the excessiveexpression of GFAP after optic nerve injury, and prolong the useful expressionof GFAP. |
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