Role of Caspase-3 in acute light damage to retina of rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the role of Caspase-3 in retinal damage caused by light exposure in rats.</p><p><b>METHODS</b>Light injury to retina was induced by persistent exposure to illumination (intensity: 30 000 +/- 50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1, 3, 7, and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis.</p><p><b>RESULTS</b>The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, especially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pigment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day.</p><p><b>CONCLUSION</b>Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.</p>

Analysis on the effect of secondary mutations on Leber's hereditary optic neuropathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effect of secondary mutations on Leber's hereditary optic neuropathy (LHON).</p><p><b>METHODS</b>Three primary and 24 secondary mutations were identified in 4 Chinese families which included male offspring.</p><p><b>RESULTS</b>All of the four pedigrees carried classic LHON mutations at nucleotide (nt) 11778, and did not carry any point of 24 secondary mutations. Nevertheless many polymorphic points were found in the nearby fragments of these pedigrees, such as 5178, 5108, 3705, 3721, 13734, etc.</p><p><b>CONCLUSION</b>Male offspring sequences should be analyzed in pedigrees with LHON to avoid the influence of familial inheritance characteristic which mitochondrial DNA polymorphism carried. Existence of the "repair genes" may affect the development of LHON.</p>

Changes of NF-kappaB/I kappa B alpha in N-methyl-N-nitrosourea-induced retinal damage in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the changes of nuclear factor-kappa B (NF-kappaB) in the course of N-methyl-N-nitrosourea (MNU)-induced apoptosis of rat retinal photoreceptor cells and investigate the mechanism of MNU-induced retinal damage.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats, which were sacrificed at different intervals after MNU treatment. The retinal damage was examined with optical microscopy and photoreceptor cell apoptosis detected by TUNEL assay. Western blotting was performed to analyze the changes in NF-kappaB.</p><p><b>RESULTS</b>Pyknosis of the photoreceptor cell nuclei and disorientation of the outer segment of the photoreceptor layer was observed 24 h after MNU treatment, and the outer nuclear layer and photoreceptor layer were almost completely lost on day 7. Photoreceptor cell apoptosis peaked at 24 h, and in the apoptotic cascade, NF-kappaB p65 protein was only detected 12 and 24 h after MNU treatment, whereas the amount of I kappa B alpha, in contrast, markedly increased in the cytoplasm as well as in the nuclei.</p><p><b>CONCLUSION</b>MNU-induced retinal damage might be mediated through the signaling pathway of NF-kappaB/I kappa B alpha.</p>

Inhibitory effect of tetrandrine eye drops on corneal allograft rejection in rats / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To observe the effect of tetrandrine (Ted) eye drops of different concentrations on corneal graft and on allograft rejection in rats.64 SD rats and they were then randomly divided into 3,5, 10g/L tetrandrine eye drops-treated and control groups. At different times postoperatively, neovascularization and inflammation of corneal graft were observed using slit-lamp microscopy, HE staining, light microscopy and microphoto-analysis.lymphocytes and mononuclear-macrophages. Corneal neovascularization and inflammation were significantly inhibited in the 5g/L Tet-treated group (P ＜0.05),compared with control group at 7, 14, 21, 28d postoperatively.bubble appeared when the graft was treated with tetrandrine of higher concentration (10g/L), but 5g/L Tet eye drops significantly inhibited corneal allograft rejection in rats without serious side-effects.

Protective effects of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea and its mechanism / 药学学报

<p><b>AIM</b>To study the protective effect of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley (SD) rats.</p><p><b>METHODS</b>Ligustrazine injections of different doses were injected intraperitoneally into 47-day female SD rats once a day and a single intraperitoneal injection of MNU 60 mg x kg(-1) was given to 50-day rats. At different intervals after MNU treatment,the animals were sacrificed. The apoptotic index of photoreceptor cells was calculated by TUNEL labeling at 24 h following MNU treatment; peripheral retinal damage was evaluated based on retinal thickness at the d 7 after MNU treatment, and the expression of c-jun and c-fos genes was detected by RT-PCR technique.</p><p><b>RESULTS</b>Ligustrazine injection could remarkably increase total thickness of peripheral retina and decrease apoptotic index of photoreceptor cells induced by MNU in a dose-dependent manner. Compared with MNU-treated rats, the gene expression of c-jun and c-fos was time-dependently down-regulated in ligustrazine-treated group.</p><p><b>CONCLUSION</b>Ligustrazine injection partially protects against MNU-induced retinal damage by down-modulating the expression of c-jun and c-fos genes to inhibit apoptosis of photoreceptor cells.</p>

N-methyl-N-nitrosourea-induced apoptosis of photoreceptor cells in Sprague-Dawley rats via nuclear factor-kappaB / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have showed that photooxidative stress can lead to down-modulation of nuclear factor-kappa B (NF-kappaB) activity causing apoptosis of cultured photoreceptor cells. This study aimed at investigating whether NF-kappaB was involved in photoreceptor cells apoptosis induced by N-methyl-N-nitrosourea (MNU) in rats.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats. At different intervals after MNU treatment, the animals were sacrificed. Retinal damage was examined by a light microscope. The apoptotic index of the photoreceptor cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL). NF-kappaB was analysed by Western blot and Transcriptin Factor Assay Kits.</p><p><b>RESULTS</b>The pyknosis of the photoreceptor nuclei and the disorientation of the outer segment of the photoreceptor layer was seen after MNU treatment for 24 hours. The outer nuclear layer and photoreceptor layer were almost completely lost at 7 days. Photoreceptor cells apoptosis reached the peaked value at 24 hours. In apoptotic cascade, the protein levels of NF-kappaB p65 were only detected after MNU treatment for 12 and 24 hours in the nucleus. Conversely, the amounts of IkappaBalpha were markedly increased in the cytoplasm as well as in the nucleus. The activity of NF-kappaB p65 in the nucleus was down-modulated in the end.</p><p><b>CONCLUSIONS</b>MNU-induced photoreceptor cell destruction was attributed to the apoptotic process by down-regulating the activation of NF-kappaB p65.</p>

PCNA, Bcl-2 and TERT expression in epiretinal membrane of rat traumatic proliferative vitreoretinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To explore the dynamic expression and correlation among telomerase catalytic subunit (TERT), proliferating cell nuclear antigen ( PCNA) and antiapoptosis protein Bd-2 which relate to cell proliferation in epiretinal membrane of rat traumatic proliferative vitreoretinopathy(PVR).· METHODS: S-P technique was applied for immunohistochemical staining of epiretinal membrane of traumatic PVR with TERT, PCNA and Bcl-2 antibody. HE staining was also carried out. The staining results were analyzed with image analysis system.· RESULTS: The positive rate and average A of PCNA protein were upregulated at first and then down-regulated, with the peak value in 14d Group, which was significantly different from those in 7d Group and 28d Group.The positive rate and average A of TERT and Bcl-2 were also upregulated at first and then down-regulated, with the peak value in 14d Group and 21d Group, which were significantly different from those in 7d Group. There was significant correlation among PCNA, Bcl-2 and TERT protein expression (P≤0.01).· CONCLUSTON: TERT and Bcl-2 take part in the regulation of proliferative cells in epiretinal membrane of traumatic proliferative PVR, with high correlation with the dynamic changes of cell proliferation.