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find Keyword "视网膜神经节细胞/生理学" 5 results
  • Protective effect of blocking the signal path of p38 mitogen activated protein kinase on blood retinal barrier and retinal ganglion cells in early diabetic rats

    Objective To investigate the protective effect of blocking the signal path of p38 mitogen activated protein kinase on blood retinal barrier (BRB) and retinal ganglion cells (RGC) in early diabetic rats.Methods A total of 60 Wistar rats were divided into the control and diabetes group, with 30 rats in each group. Diabetes was induced in rats in diabetes group by peritoneal injection of streptozotocin (STZ);the plasma glucose level of >16.7 mmol/L indicated that the diabetes model was set up successfully.The rats in the control group underwent peritoneal injection of equivalent sodium citrate solution. IgG leakage method was used to measure the damage of BRB function and vascular leakage. The expression and localization of caspase-3 and vascular endothelial growth factor (VEGF) in retina of diabetic rats were examined by immunohistochemistry analyses.Two weeks after the establishment of the diabtes model, the rats in diabtes group underwent intravitreal injection with SB203580, a p38 inhibitor;six weeks after the injection, the expression of caspase-3 and VEGF was detected, and the number of apoptosis RGC was counted via immunofluorescence technique.Results In the contral group, IgG staining located in the blood vessels with little leakage; while the IgG leakage was much more obvious in the diabetes group eight weeks after the establishment of the model. Six weeks after intravitreal injection with SB203580, the leakage decreased in diabtes rats. The results of semiquantitative analysis and fluorescence immunohistochemistry showed that compared with the results in diabetes rats 8 weeks after intravitreal injection (2.9 times much more than that in the control group), the fluorescence expression of VEGF decreased in diabetes rats six weeks after intravitreal injection (1.8 times much more than that in the control group).The apoptisis RGC number in rats 6 weeks after intravitreal injection of SB203580 was much less than that in rats without intravitreal injection (t=5.731, Plt;0.01). Conclusions SB203580 can alleviate the disruption of BRB and apoptosis of RGC in early diabetes rats, which suggests that p38 MAPK pathways appear to be directly involved in the pathogenesis of early diabetic retinopathy.

    Release date:2016-09-02 05:40 Export PDF Favorites Scan
  • Microglial activation and ganglion cells damages in the rat retina with early stage streptozotocin induced diabetes

    Objective To observe the relationship between retinal microglial activations and ganglion cell (RGC) damages in early-stage diabetic rats. Methods A total of 20 SpragueDawley(SD)rats were randomly divided into 4 groups (each with 5 rats): 1 month control group, 1 month diabetes group, 3 month control group, 3 month diabetes group. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ). The RGCs of all rats were retrograde labeled by carbocyanine dye DiI injected at the superior colliculi.Microglial cells and RGCs in retinal flat-mounts and sections were stained immunohistochemically and recorded under confocal microscope.Results The diabetic microglial cells were amoeboid and ovoid with fewer processes on retinal flat mounts. The density of microglial cells which phagocytosed DiI particles in the RGC layer significantly increased in the 3month diabetes group(P<0.01). The density of microglial cells in the RGC layer significantly increased in the 1- and 3- month diabetes group(P<0.05). However there were more microglial cells in the RGC layer in the 3- month diabetes group than the 1-month diabetes group(P<0.0001). Significant correlation was found between the amount of microglial cells and that of RGCs in the early-stage of diabetes. Conclusions Microglial cell activation has close relationship with the RGC damages in early-stage diabetic rats.

    Release date:2016-09-02 05:40 Export PDF Favorites Scan
  • Effects of proteasome inhibitor MG132 nuclear factorkappa B pathway and retinal ganglion cells apoptosis in rats with diabetic retinopathy

    Objective To observe the degradation regulation of ubiquitinproteasome inhibitor nuclear factor kappa;B(NF-kappa;B)and its inhibitory signal protein Ikappa;B kinase in earlier period diabetic retinopathy(DR),and the effects on retinal ganglion cells (RGC) apoptosis.Methods Forty healthy adult Wistar rats were randomly divided into control (group A),DR(group B),DR+lowconcentration MG132 treated (group C)and DR+high concentration MG132 treated(group D)groups,10 rats in each group.After 6 and 8 weeks,the results of body masses and fasting blood glucose (FBG) were detected,the expression of NF-kappa;B and Ikappa;B were observed by immunohistochemistry respectively.RGC apoptosis was assessed by the terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labelling (TUNEL) method.Results The expression of NF-kappa;B was upregulated in group B compared with group A,its expression decreased in group D compared with group B; but the expression of Ikappa;B was contrary to NF-kappa;B; RGC apoptosis was followed a similar pattern with the expression of NF-kappa;B; the differences among them were statistically significant (P<0.01).Compared the expression of NF-kappa;B,Ikappa;B and RGC apoptosis in group C and D, there were no statistically significant differences(P>0.05).Conclusion Ubiquitin-proteasome inhibitor MG132 can block the activation of NF-kappa;B,inhibit ubiquitination of Ikappa;B degradation and RGC apoptosis.

    Release date:2016-09-02 05:40 Export PDF Favorites Scan
  • 雌激素对视网膜主要细胞功能的影响

    雌激素通过与雌激素受体(ER)结合而发挥生理功能, ER亚型和特异性激动剂和拮抗剂的研究进展为进一步认识雌激素作用机制提供了可能。雌激素可能通过对视网膜血管内皮细胞、色素上皮细胞、神经节细胞、光感受器细胞和Müller细胞等主要视网膜细胞功能的影响, 改善血视网膜屏障、保护视网膜光感受器细胞、视神经, 减轻氧化应激反应对视网膜色素上皮细胞损害。详尽研究ER各亚型在视网膜主要细胞的分布及特异性激动剂和拮抗剂对这些细胞的作用将为眼底病的防治开拓一个新的领域。

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  • The effects of down-regulation of Claudin-3 on the cultured retinal ganglion cells in vitro

    Objective To study the effect of down-regulation of Claudin-3 mediated by adeno-associated virus (AAV) of shRNA on the cultured retinal ganglion cells (RGCs) in vitro. Methods RGCs isolated from mouse eyes were divided into normal control group, AAV-shScramble group, and AAV-shClaudin-3 group. The RGCs in AAV-shScramble group and AAV-shClaudin3 group were treated with AAV-shScramble and AAV-shClaudin-3 respectively 24 hours after cell seeding. Dynamic live cell fluorescence microscopy was used to observe the transfection efficiency 96 hours after transfection. Immunofluorescent staining of β-tubulin was used to measure the length of RGCs′ axon. 4′, 6-diamidino-2-phenylindole staining was used to observe the nuclei of apoptotic cells. The mRNA level of Claudin-3 and VEGF was measured by real-time polymerase chain reaction. The protein levels of Claudin-3, vascular endothelial growth factor (VEGF), Bcl-2 and Caspase-3 was determined by Western blot. Results The positive transfection rate was more than 50% in both AAV-shScramble group and AAV-shClaudin-3 group. The length of RGCs' axon in AAV-shClaudin-3 group was shorter than that in normal control group and AAV-shScramble group (F=22 363.274,P<0.05). Down-regulation of Claudin-3 accelerated RGCs' apoptosis with nuclei shrinkage, tapering, and nucleolus formation of apoptotic bodies. The mRNA levels of Claudin-3 and VEGF in AAV-shClaudin-3 group were lower than those in normal control group and AAV-shScramble group (F=257.408, 160.533;P<0.05). The protein levels of Claudin-3, VEGF and Bcl-2 in AAV-shClaudin-3 group were lower than those in normal control group and AAV-shScramble group (F=129.671, 420.552, 62.669;P<0.05), while the protein level of Caspase-3 in AAV-shClaudin-3 group was higher than that in normal control group and AAV-shScramble group (F=231.348,P<0.05). Conclusion Down-regulation of Claudin-3 increases the expression of Caspase-3, reduces the expression of VEGF and Bcl-2, accelerates RGCs' apoptosis and inhibit the RGCs' axon growth.

    Release date:2017-04-01 08:56 Export PDF Favorites Scan
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