ObjectiveTo investigate the effect of DJ-1 encoded by Park7 gene on retinal ganglion cells (RGC) and visual function after optic nerve crush injury (ONC) in mice.MethodsThirty-seven and 116 healthy male C57BL/6J mice were randomly divided into group normal, group ONC 2d, group ONC 5d, group ONC 7d and group control, group Park7, group Park7-ONC, group ONC and group green fluorescent protein (GFP)-ONC. Group ONC 2d, group ONC 5d and group ONC 7d were sacrificed on the 2nd, 5th and 7th day after the establishment of ONC model, and the follow-up experiments were carried out. The mice in group Park7 and group Park7-ONC were injected 1 μ recombinant adeno-associated virus (rAAV) with knocking down Park7 gene into vitreous cavity, and 1 μ l rAAV with only GFP was injected into vitreous cavity of mice in group GFP- ONC, and virus transfection was observed 4 weeks after injection. The injury of ONC was perfomed at 23 days after vitreous injection in group ONC, group Park7-ONC and group GFP-ONC, and the samples were taken for follow-up experiment 5 days after modeling. The average density of RGC was observed by immunofluorescence staining, the latencies and amplitudes of a-wave, b-wave and photopic negative response (phNR) and the amplitude of oscillatory potential (OPs)were detected by full-field flash electroretinogram,and the visual acuity of mice was measured by optomotor response (OMR). The relative expression levels of DJ-1, Bax and B lymphoblastoma / leukemia-2 (Bcl-2) protein in the retina of mice in each group were detected by Western blot. One-way ANOVA was used to compare the data between groups, and t-test was used for pairwise comparison between groups.ResultsCompared with the normal group, the relative expression of DJ-1 protein in the retina of the ONC 2 d group and ONC 5 d group increased significantly, and the difference was statistically significant (t=16.610, 5.628, P＜0.01,＜0.05). Four weeks after virus transfection, strong GFP expression was seen in the RGC layer and inner plexiform layer of the retina of mice in the Park7 group. Compared with the control group, the RGC density of the retina in the ONC group decreased significantly, and the difference was statistically significant (t=16.520, P＜0.000); compared with the ONC group, the RGC density of the retina in the Park7-ONC group decreased significantly, and the difference was statistically significant (t=6.074, P＜0.01). With the increase of stimulus light intensity, the dark adaptation a wave and b wave latency of the mice in the control group gradually shortened, and the amplitude gradually increased. The stimulus light intensity was 3 cd·s/m2. There was no statistically significant difference in the dark adaptation a wave and b wave latency and amplitude of the control group, Park7 group, Park7-ONC group, ONC group, and GFP-ONC group (Incubation period: F=0.503, 2.592; P=0.734, 0.068. Amplitude: F=0.439, 1.451; P=0.779, 0.247). Compared with the control group, the Ops and PhNR amplitudes of the ONC group mice were significantly decreased (t=15.07, 12.80; P＜0.000,＜0.001). Compared with the ONC group, the Ops and PhNR amplitudes of the mice in the Park7-ONC group were significantly decreased (t=4.042, 5.062; P＜0.05,＜0.01); there was no statistically significant difference in the PhNR latency of the mice in each group (F=1.327, P=0.287). Compared with the control group, the visual acuity of the mice in the ONC group was significantly decreased, and the difference was statistically significant (t=23.020, P＜0.000); compared with the ONC group, the visual acuity of the mice in the Park7-ONC group was significantly decreased, and the difference was statistically significant (t=3.669, P＜0.05). Compared with the control group, Park7-ONC group and ONC group, the relative expression of DJ-1 protein in the mouse retina was significantly down-regulated, and the difference was statistically significant (t=47.140, 26.920; P＜0.000,＜0.000). There was no significant difference between ONC group and GFP-ONC group (t=0.739, P=0.983). Compared with the ONC group, the relative expression of Bax protein in the mouse retina of the Park7-ONC group was significantly increased, and the relative expression of Bcl-2 protein was significantly reduced. The differences were statistically significant (t=5.960, 9.710; P＜0.05,＜0.05); the relative expression ratio of Bcl-2/Bax in the Park7-ONC group was significantly lower than that in the ONC group, and the difference was statistically significant (t=13.620, P＜0.01).ConclusionThe expression of DJ-1 encoded by Park7 gene is down-regulated after Park7 gene was knocked down, which aggravates the RGC damage and the decrease of retinal electrophysiological response and visual function in ONC injury mice.
The neuroretinal injuries of diabetic retinopathy (DR) include retinal neuronal damage and reactive gliosis, both of which are induced by hyperglycemia and presented as early features of DR. They promote to develop mutually and accelerate the progression of DR. The molecular mechanisms study of neuronal damage mainly focuses on the alterations of extracellular environment and related signaling pathways, include inflammation, oxidative stress, endoplasmic reticulum stress, the formation of advanced glycation end products, glutamate toxicity and so on. These alterations mainly result in neuronal apoptosis and autophagy. The damaged neurons activate the glial cells with apparent changes in morphology, cell counts and the level of intracellular protein expression. In non-proliferative DR, glial cells are moderately hypertrophic and slightly increased in numbers. In proliferative DR, there is a significant rise in glial cell number with enhanced level of inflammatory factors and vascular active substances which lead a further neuronal damage. Signaling pathways of extracellular signal-regulated kinase 1/2, c-Fos and p38 mitogen-activated protein kinase are associated with their activation. Researches on the molecular mechanisms and signaling pathways of the DR will promote controlling the DR progression at the cellular level.
Purpose
To evaluate differences in the pattern of optic disc and retinal nerve fiber layer (RNFL) damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) patients.
Methods
We enrolled 49 eyes of 49 patients:30 NTG (IOP≤21 mm Hg,1 mm Hg=0.133 kPa), 19 HTG(IOP≥25 mm Hg). Mean age was 59.2±12.3 (range, 36-75) for HTG patients, and 59.6±8.6(range, 39-71) for NTG patients. All patients underwent complete ophthalmic examination, achromatic automated perimetry (AAP), scanning laser ophthalmoscopy (SLO), scanning laser polarimetry (SLP), optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT). All patients had glaucomatous optic nerve damage and abnormal AAP.
Results
There were no differences in mean deviation on AAP between NTG and HTG eyes (P=0.37), while the corrected pattern standard deviation was larger in NTG than in HTG eyes (P=0.014). Cup∶disc area ratios in global (P=0.03) and three sectors (Plt;0.05) except nasal sector were significantly larger in the NTG group, whereas rim area in global (P=0.03) and three sectors (Plt;0.05) except nasal quadrant obtained by SLO were smaller in NTG than in HTG eyes. The other numerical parameters obtained by three imaging technologies could not detect differences in the optic disc or RNFL anatomy between the two groups.
Conclusions
Cup∶disc area ratio was larger in patients with NTG than in those with HTG, whereas significant thinning of rim was associated with NTG eyes. The measurement of retinal nerve layer thickness in global and each quadrant was similar between two groups. More focal or segmental analysis of the data contained within SLO, SLP and OCT images are needed to detect localized differences in eyes with varying levels of IOP.
(Chin J Ocul Fundus Dis, 2002, 18: 109-112)
Objective To observe the content of thromboxane (TXA2 ) and prostacyclin (PGI2) in optic nerves after forehead impact injury.Methods The right forehead zones of 32 rabbits were struck by biology impact machine. Tweenty-four rabbits that had afferent papillary defect after injury were chosen, and randomly divided into four groups: 1 day, 2, 4, and 7 days group. Right eyes were in the experimental group and left eyes were in the control group. Flash visual evoked potentials were examined before and after the traumatic injury. The rabbits ′eyes were removed, the optic nerves were pathologically examined, and the content of TXB2 and 6-Keto-PGF1αwhich were the products of TXA2 and PGI2 were assayed 1, 2, 4, and 7 days after traumatic injury respectively.Results Histopath ological examination revealed the findings of injuries of optic nerves of all the 24 rabbits. The latency of wave P1 was significantly delayed after traum atic injury (Plt;0.01), and amplitude of wave P1 was significantly decreased after traumatic injury (Plt;0.01). The content of TXB2 ［(172.35±26.52) pg/mg ］and 6-Keto-PGF1α［(161.78±24.83) pg/mg］were significantly higher in the injured optic nerves than in the uninjured ones 1 day after the traumatic injury (Plt;0.01). The rate of TXB2 /6-Keto-PGF1α (1.077±0.18) was significantly increased compared to the control group (Plt;0.05), and lasted to the 7th day.Conclusions The content of TXA2 and PGI2 significantly increases and the ratio of them is lopsided after forehead impact injury in rabbits. (Chin J Ocul Fundus Dis，2003，19：49-51)
ObjectiveTo investigate the effect of nerve growth factor (NGF) on recuperate of optic nerve after contusion by clamping in adult rabbits.
MethodsSixteen adult rabbits were randomly divided into NGF and the control group with 8 rabbits in each group. After the optic nerve of the right eyes was clamped，tissue engineering nerve containing 0.06 ml NGF（concentration: 5×10-4 g/L, NGF group） and 0.06 ml of PBS (control group) was immediately transplanted into the injured eyes respectively, and 0.02 ml NGF（concentration: 5×10-4 g/L, NGF group）and 0.02 ml of PBS (control group) were injected into the vitreous of right eyes respectively. Flash visual evoked potential (FVEP) test was performed on the eyes 1 day, 2 weeks and 8 weeks after the injury. The number of retinal ganglion cells (RGCs) and changes of optic nerves were observed by light microscopy and electron microscopy at the 8th week after contusion,and a computer-image-analysis system was used to count the optic nerve axons.ResultsThe ratio of amplitude of FVEP of the injured and healthy eyes was 0.765±0.150 in NGF group and 0.494±0.108 in the control at the 2th week after injury with a significant difference between the two groups (Plt;0.05); and was 0.581±0.138 and 0.409±0.119 respectively at the 8th week after contusion with statistical difference between the two groups (Plt;0.05). The results of light microscopy and electron microscopy showed that degeneration of RGCs and optic nerves in the NGF group was lighter than that in the control group 8 weeks after injury, while the amount of optic nerve axons was (10 955±608.7) axons/ mm2 in the NGF group and (7 898±608.8) axons/mm2 in the control with statistical difference between the two groups (Plt;0.05).
ConclusionNGF may redound to the survival of RGCs and regeneration of the axons in some degree, which can promote the recuperation of optic nerve and visual function. (Chin J Ocul Fundus Dis, 2005,21:253-257)
Objective To observe whether the animal model of optic nerve injury in rats can be set up by fluid percussion brain injury device (FPI) or not.Methods Seventyone healthy female Wister rats were randomly divided into 2 groups, inlcuding model group with 66 rats and control group with 5 rats.The rats in model group were randomly divided into 3 groups. Eight rats in group 1 were examined by flashvisual evoked potential (F-VEP) and magnetic resonance imaging (MRI) examines before and 1, 3 days,1,2,4,6,and 8 weeks after injury; 56 rats in group 2 were randomly divided into 7 subgroups with 8 rats in each subgroup，and were detected by histopathological and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) apoptosis examines 1, 3 days, 1,2,4,6,8 weeks after injury；2 rats in group 3 were examined by electron microscopy 4 and 8 weeks after injury.According to the degree of injury, the injured eyes were divided into 2 groups including severe injury group with the beat pressure of （699.14plusmn;60.79） kPa and mild injury group with the beat pressure of （243.18plusmn;20.26） kPa.The right and left eyes in rats in each group were in severe and mild injury group, respectively.Results One day after injury, the latency duration of FVEP prolonged in severe injury group，wich differed much form which in the normal control group (P＜0.05)；the amplitude was gradually reduced during the first 2 weeks after injury and kept steady after that (P＞0.05). The latency duration prolonged in mild injury group,and its difference with the normal control group was statistically significant (P＜0.05)；the amplitude was gradually reduced during the first 4 weeks after injury and kept steady after that (P＞0.05). The abnormal high signal could be seen on optic nerve 1 day after injury, and was still obvious 8 weeks later. The results of histopathological examination showed ruptured capillary in ganglion cell layer 1 day after injury;retinal ganglion cells without nucleus could be seen 4 weeks after injury. The apoptosis of positive cells was found in each layer of the retina 3 days after injury.TUNEL results indicated that the number of apoptotic positive cells increased significantly 1-2 weeks after injury.Conclusion An animal model of optic nerve injury can be successfully set up using FPI in rats.
ObjectiveTo investigate the gene expression spectrum of retina and optic nerve after partial injury of optic nerve.MethodsSixty SD rats were randomly divided into 4 groups. The optic nerves of the right eyes were clipped for 6 seconds with a pair of crossaction forceps. The retinae and optic nerves in the operation eye and contralateral sham operation eye were removed 3, 7, 14, and 21 days after the injury to detect gene expression patterns with high-density DNA microarrays.ResultsChanges of a mass of gene expressions were found after the optic nerve injury, and the positive rate of gene expression was 2.35%, 6.48%, 3.82% and 4.09% after 3, 7, 14, 21 days, respectively, and the total positive rate was 11.77%. The functions of positive expression of the gene involved cell survival, cytoskeleton, extracellular matrix and cell adhesion, free radicals and oxidative damage, energy and metabolism, inflammation, neurotransmission and ion transport, signal transduction, structural protein, transcription and translation. Up-or down-regulation of repaired genes was the main part of the changes of gene expression, while the alteredexpression destroy genes was the minor part in the whole gene expression spectrum, in which the up- and down-regulation of expression of repaired genes accounted for 13.98% and 24.73% respectively 7 days after the injury, and the downregulation of expression of repaired genes accounted for 17.20% 14 days after the injury.ConclusionsA mass of gene expression changes occurs after the optic nerve injury, and the comprehensive view on the gene expression pattern following the optic nerve injury is crucial to discover the mechanism of post-injury reaction and regeneration.(Chin J Ocul Fundus Dis, 2005,21:163-166)
Objective
To evaluate the relevant factors affecting prognosis of traumatic optic neuropathy.
Methods
Sixty-nine patients with traumatic optic neuropathy were enrolled. Multiple variable analysis was done to filter the risk factors to prognosis in traumatic optic neuropathy.
Results
At 3 months or more of followup,no light perception was found in 32 cases (46.4%); visual acuity were increased by≥1 lines in 33 cases (47.8%). The outcome of visual acuity was poorer in patients with the following conditions:no light perception after trauma （P=0.0031）, loss of consciousness （P=0.0262）, no pretreated common-dosage corticosteroids （P=0.0184）, and absence of VEP （P=0.0001）.
Conclusion
The initial visual acuity of no light perception, loss of consciousness, and no pretreated common-dosage corticosteroids were the risk factors to prognosis in traumatic optic neuropathy,and result of VEP was an effective prognosis indicator in traumatic optic neuropathy.
(Chin J Ocul Fundus Dis, 2002, 18: 98-100)
Objective To investigate the mRNA expression of ciliary neurotrophic factor on the retina during injury and repair of optic nerves in rats. Methods Thirty-five healthy SD rats were randomly divided into 3 groups: 5 in the control group, 15 in the simply transected optic nerve group and 15 in the optic nerve-sciatic nerve anastomosis group. The simply transected and optic nerve-sciatic nerve anastomosed models were set up, and the retinal tissues of all of the rats were taken out after 3, 7 and 14 days, respectively; and the mRNA expression of CNTF in the 3 groups were observed by semiquantitative reversal transcription-polymerase chain reaction method. Results A minimum expression of CNTF mRNA was found in the retinae of the control group, and the increased rates of expression were found in the retinae of the simple transection of optic nerve group with the increase rate of 100%, 594%, and 485% on the 3rd, 7th, and 14th day respectively after the operation, while in optic nerve-sciatic nerve anastomosis group, the increase rates were found to be 258%, 752% and 515% on the 3rd, 7th, and 14th day respectively after the operation. Conclusion Retinal neurons can respond to axonal reaction of retinal ganglion cells by up-regulate endogenous CNTF after the injury of the optic nerves, which may provide a theoretic base for the application of the exogenous CNTF. (Chin J Ocul Fundus Dis，2004，20：355-357)
Objective To explore the role of activated macrophage in the repair of traumatic optic nerve injury in an animal model of incomplete traumatic optic nerve injury with lens damage.Methods One hundred and twelve healthy New Zealand big ear white rabbits were divided into two groups (experimental and control groups) randomly. According to the different time points (one, four, seven, ten, 14, 21 and 28 days), each group was further divided into seven subgroups, each subgroup had eight rabbits. Traumatic optic neuropathy and lens damage were induced in one eye of each rabbit by fluid percussion brain injury device (FPI); those eyes were the experimental group. The eyes of control group only had traumatic optic neuropathy. The functional and morphological changes of retina and optic nerve were evaluated by histopathology and flashvisual evoked potential (FVEP).Results FVEP P100 latency was (42.74plusmn; 5.83) ms, P100 amplitude was (7.98 plusmn; 2.15) mu;V before optic nerve injury was induced. One day after the injury, the P100latency increased and the P100amplitude reduced significantly. The P100 latency reached the longest at ten days after injury, and then recovered gradually. The P100 amplitude reached the lowest at seven days after injury, and then recovered gradually. The histopathological examination showed activated macrophages were not detected in the retina and optic nerve at day one after the injury, then they increased gradually and reached their peak (91.25plusmn;6.91) at day ten, and decreased after that, the difference was statistically significant (F=21.277, P=0.000); retinal ganglion cell axon regeneration began at day seven after the injury with an average of (6.38plusmn;1.85). The axons increased gradually and reached their peak (49.63plusmn;2.50) at day 28, and the changes were significant (F=7.711, P=0.000). Conclusions Incomplete optic nerve injury can recover gradually if there is lens damage at the same time. Activated macrophage may play an important role in this recovery process.
