腺病毒介导睫状神经营养因子在大鼠视网膜中的表达定位

目的观察携带睫状神经营养因子(ciliary neurotrophic factor,CNTF)基因的腺病毒(adenovirus,Ad)载体在正常大鼠视网膜中的表达定位。方法正常成年大鼠40只,随机分为处理组(PBS组、Ad-LacZ组、Ad-CNTF组)及正常对照组,向处理组大鼠眼内分别注射相应溶液,各处理组均分为注射后7d、14d、28d共3个时相点。在相应时相点取大鼠眼球,行冰冻切片,进行免疫组织化学染色。结果Ad-CNTF组各时相点视网膜与其他对照组相比,CNTF阳性染色明显增强,分布更广泛,并且可一直持续到注射后28d。结论Ad-CNTF在正常大鼠眼内注射后,CNTF在视网膜的表达明显增加,且表达时限可达28d。     

视神经损伤时视网膜睫状神经营养因子受体的表达

目的研究睫状神经营养因子受体于视神经损伤后不同时间在视网膜中的表达情况,探讨外源性的睫状神经营养因子在神经损伤疾病中的应用价值。方法采用钳夹视神经的方法建立神经损伤的模型,在损伤后1、7、14、28d获取视网膜,提取总RNA及总蛋白,用半定量逆转录聚合酶链反应(RT-PCR)测定视网膜中睫状神经营养因子受体(CNTFR)αmRNA的表达,用WesternBlot方法了解损伤后不同时间CNTFRα蛋白水平的表达。结果在正常大鼠视网膜内CNTFRαmRNA无表达,在损伤后的1、7、14、28d均有一定水平的CNTFRαmRNA的表达,与正常对照比较差别具有显著性意义(P<0.01);损伤后备时间均有CNTFRα蛋白的表达,但CNTFRα蛋白的表达较弱。结论神经损伤后CNTF的表达先短暂升高以后持续下调,而CNTFRα-mRNA在损伤后4周内均有一定量的表达,提示补充外源性CNTF可能改善神经再生的微环境而发挥保护效应。     

负透镜诱导型近视豚鼠视网膜中谷氨酸及其受体的表达

目的　观察谷氨酸及其离子型受体Ｎ-甲基-Ｄ-天冬氨酸受体（Ｎ-ｍｅｔｈｙｌ-Ｄ-ａｓｐａｒｔａｔｅｒｅｃｅｐｔｏｒ,ＮＭＤＡＲ）功能亚单位ＮＲ２Ａ在近视豚鼠视网膜上的动态表达,探讨其在近视发病过程中的作用。方法　选取３周龄健康三色短毛豚鼠１２０只,采用随机数字表法分为０周正常组、２周正常组、２周近视组、４周正常组、４周近视组,每组２４只;正常组不作任何干预,近视组右眼均戴－１０Ｄ透镜,左眼不戴镜作为对照。入组前与处死前均进行屈光度及眼轴长度检测,腹腔注射过量水合氯醛处死,并分离视网膜,采用高效液相色谱分析检测视网膜中谷氨酸的含量变化,实时荧光定量ＰＣＲ以及ＥＬＩＳＡ分别检测豚鼠视网膜中ＮＲ２ＡｍＲＮＡ及其蛋白水平的表达变化。结果　造模前各组屈光度及眼轴长度差异均无统计学意义（均为Ｐ＞０．０５）。造模后各组与造模前比较,眼轴长度及屈光度差异均有统计学意义（２周正常组Ｐ＜０．０５,２周近视组Ｐ＜０．００５,４周正常组Ｐ＜０．０１,４周近视组Ｐ＜０．００１）。造模后,正常组间眼轴长度和屈光度比较差异均有统计学意义（Ｆ＝２０．３２,Ｐ＜０．０１;Ｆ＝１９９．６５,Ｐ＜０．０１）;２周近视组与４周近视组比较,右眼眼轴长度和屈光度差异均有统计学意义（Ｆ＝７８．９６,Ｐ＜０．００１;Ｆ＝２５２．１０,Ｐ＜０．００１）,左眼眼轴长度和屈光度差异均无统计学意义（Ｆ＝１３．６６,Ｐ＞０．０５;Ｆ＝２１．２０,Ｐ＞０．０５）;２周近视组与４周近视组右眼分别与相应的左眼比较,眼轴长度差异均有统计学意义（２周近视组:ｔ＝９．５１５,Ｐ＜０．００５;４周近视组:ｔ＝９．４４９,Ｐ＜０．００１）,屈光度差异同样均有统计学意义（２周近视组:ｔ＝８．８９７,Ｐ＜０．００１;４周近视组:ｔ＝１７．２３５,Ｐ＜０．００１）。视网膜中谷氨酸含量正常组之间差异均无统计学意义（均为Ｐ＞０．０５）;造模后２周近视组与４周近视组比较,右眼视网膜中谷氨酸含量逐渐增加,差异有统计学意义（ｔ＝３６．２３０,Ｐ＜０．０１）。造模后２周近视组较２周正常组右眼谷氨酸含量增加,差异有统计学意义（ｔ＝－２３．２４０,Ｐ＜０．０５）;同样４周近视组较４周正常组右眼谷氨酸含量亦增加,差异亦有统计学意义（ｔ＝－５３．６９０,Ｐ＜０．０１）。视网膜中ＮＲ２ＡｍＲＮＡ的表达量,正常组之间差异均无统计学意义（均为Ｐ＞０．０５）。造模后４周近视组与２周近视组比较,右眼视网膜ＮＲ２ＡｍＲＮＡ表达量明显上调,差异有统计学意义（ｔ＝５５．６６０,Ｐ＜０．００１）;２周近视组与２周正常组右眼比较表达量增加,差异有统计学意义（ｔ＝－１５．０８６,Ｐ＜０．００５）,同样４周近视组与４周正常组右眼比较差异亦有统计学意义（ｔ＝－４３．２７６,Ｐ＜０．００１）。正常组之间视网膜中ＮＲ２Ａ蛋白表达量,差异无统计学意义（均为Ｐ＞０．０５）。４周近视组与２周近视组比较,右眼视网膜ＮＲ２Ａ蛋白表达量明显上调,差异有统计学意义（ｔ＝４３．２１０,Ｐ＜０．００５）;２周近视组与２周正常组右眼比较ＮＲ２Ａ蛋白表达量增加,差异有统计学意义（ｔ＝－２．３６５,Ｐ＜０．０５）,同样４周近视组与４周正常组右眼比较差异亦有统计学意义（ｔ＝－５．５１８,Ｐ＜０．０１）。结论负透镜诱导型近视豚鼠视网膜中谷氨酸及其ＮＭＤＡＲ受体亚单位ＮＲ２Ａ在透镜诱导眼中表达上调,并随透镜诱导时间的延长和近视程度的加深而增加。     

Immunocytochemical localization of taurine in the mammalian retina

This paper describes the first demonstration of taurine-like immunoreactivity in the mammalian retina using an antiserum raised in rabbits. In rat, cat and guinea pig retina a peroxidase-antiperoxidase immunocytochemical technique showed high levels of taurine immunostaining in photoreceptor inner segments and synaptic terminals, in subpopulations of amacrine and bipolar somata and their synaptic processes in the inner plexiform layer, including numerous large terminals near and on ganglion cell somata. Using the Protein A-gold technique for ultrastructural studies in the rat, the presence of synaptic ribbons confirmed that some of these taurine-containing terminals were from bipolar cells. Lower levels of immunostaining were seen in the pigment epithelium and distal parts of glial cells.     

Thyrotropin releasing hormone: apparent receptor binding in retina.

Thyrotropin releasing hormone (TRH) binds with high affinity to sites on sheep retinal membranes. These sites closely resemble sheep pituitary receptors for TRH, as determined by direct comparison of binding in the two tissues. Specific [³H]TRH binding in sheep pituitary and retina was measured relative to blanks containing 1 μm [3-Me-His²]TRH, an analog more selective and 10-fold more potent than TRH. Incubations were at 0°C; bound radioactivity was separated by filtration. High affinity retinal TRH binding sites resembled pituitary receptors in (1) equilibrium dissociation constant (about 20–40 nm), (2) rate constant for association (about 1–2 μm^?1 min^?1), (3) rate constant for dissociation (about 0·07 min^?1), (4) effectiveness of 16 TRH analogs, ranging over six orders of magnitude in potency, in competing for binding. Major differences were (1) the retinal binding sites were present in only one quarter the concentration of pituitary receptors (about 5 pmol/g wet weight vs. 20 pmol/g wet weight) and (2) the pharmacological properties of retinal binding sites were partially obscured by the simultaneous presence of low affinity binding sites, absent in pituitary, with which 6 analogs appeared to compete more potently than for high affinity sites. These findings support the possibility that TRH or a closely related substance acts as a peptide neurotransmitter or neuromodulator in the retina.     

syndecan-1在糖尿病视网膜中的表达

目的:观察syndecan-1在增殖性糖尿病视网膜病变患者视网膜增殖膜及糖尿病大鼠视网膜中的表达变化。方法:SD大鼠行链脲佐菌素腹腔注射以诱导糖尿病。造模成功后,墨汁灌注及视网膜铺片观察视网膜的血管情况。免疫组织化学染色检测大鼠视网膜及人糖尿病视网膜增殖膜中syndecan-1蛋白的表达。结果:糖尿病大鼠9wk时,视网膜周边血管走形迂曲,毛细血管网明显减少,部分毛细血管灌注不良。对照组大鼠的视网膜syndecan-1呈阳性表达,其中神经纤维层、节细胞层呈强阳性表达,内丛状层和光感受器外节呈中度阳性表达,外丛状层呈弱阳性表达。糖尿病大鼠视网膜中,syndecan-1的表达减低,其中神经纤维层、神经节细胞层、光感受器外节呈中度阳性表达,内丛状层及外丛状层呈弱阳性表达。13例人糖尿病视网膜病变视网膜增殖膜标本中,syndecan-1弱阳性表达8例(61.5%),阴性表达5例(38.5%)。结论:临床和动物实验共同表明,糖尿病状态下,视网膜中syndecan-1的表达降低。     

Towards an understanding of the role of dopamine in the mammalian retina

The role of the neurotransmitter dopamine in visual processing in the mammalian retina is not known. We investigated the effects of the dopamine antagonists haloperidol and fluphenazine on the receptive field properties of rabbit ganglion cells. The results that we have obtained so far are limited to brisk cells and on-off directionally selective cells. The dopamine antagonists, in general, decreased the on responses of the cells while not affecting or slightly increasing the off responses. The results are described in relation to the known anatomy and pharmacology of the dopaminergic neurons of the retina.     

Expression of thromboxane synthase and the thromboxane-prostanoid receptor in the mouse and rat retina

Experimental models of the diabetic retina have suggested a pathological role for thromboxane. To date however, little information is available as to the cellular locations of retinal thromboxane synthase (TxS), or its receptor, even in non-diabetic controls. In this study, C57BL/6 mice and Wistar rats were injected with streptozotocin to induce diabetes, or with buffer for non-diabetic controls. Four weeks following the injection, eyes were enucleated and labeled for TxS and the thromboxane-prostanoid (TP) receptor. Immunofluorescent intensity was quantified in the ganglion cell plus inner plexiform layers, inner nuclear layer, outer plexiform layer, outer nuclear layer, and photoreceptor inner segment. Even in control mice and rats, all layers of the retina showed immunoreactivity for TxS and the TP receptor: however, the pattern of expression demonstrated an inverse relationship, with the highest TxS staining in the inner retina, and the highest TP receptor staining in the outer retina (more specifically, in the photoreceptor inner segment). Four weeks of hyperglycemia did not increase the retinal levels of TxS or TP receptor; however, TP receptor intensities in the outer retina of diabetic rats were highly variable (mostly high but some low), with no values from the photoreceptor inner segment in the same range as obtained from controls.     

高原缺氧对兔视网膜Nogo表达的影响

目的:观察在高原环境下Nogo在北京青紫蓝兔视网膜中的表达和分布。方法:北京青紫蓝兔24只随机分为实验组20只,对照组4只,分别喂养于高原环境和亚高原环境中1,3,7,10,14d取出兔眼球,制成蜡片,应用免疫组化的方法检测视网膜中Nogo的表达及分布。结果:在高原环境下Nogo在兔视网膜中的表达增多,7d达到高峰,持续到10,14d下降,与对照组比较,差异有统计学意义。结论:在高原环境下,Nogo在视网膜急性缺血缺氧损伤可能发挥了重要作用。     

Glycoprotein synthesis in the human retina: localization of the lipid intermediate pathway

Retinal tissue from human eye donors was incubated with [3H]-labeled mannose, glucosamine, fucose, and leucine in the presence and absence of tunicamycin, a selective inhibitor of dolichol-dependent glycoprotein biosynthesis. The incorporation of labeled substrates was examined by quantitative light microscopic autoradiography and biochemical methods. [3H]-Mannose and [3H]-fucose were predominantly incorporated into the photoreceptor layer, while [3H]-glucosamine and [3H]-leucine labeled the entire retinal expanse. Tunicamycin caused a marked and selective reduction in the incorporation of [3H]-mannose and [3H]-glucosamine in the photoreceptor layer (especially the inner segments) without affecting the relative distribution of labeled products derived from [3H]-fucose or [3H]-leucine. All three [3H]-labeled sugars were incorporated preferentially into rod inner segments, relative to cones. Dual-label experiments with [3H]-sugars and [14C]-leucine revealed that tunicamycin selectively inhibited the incorporation of [3H]-mannose, but not the other substrates, into total retinal TCA-precipitable material. This inhibition was not due to decreased mannose uptake by retinal cells. Detergent-solubilized retinas were analyzed by polyacrylamide gel electrophoresis and fluorography. The results indicated that each labeled substrate was incorporated into a variety of glyoproteins, including a component having the electrophoretic mobility of opsin. These results suggest that the lipid intermediate pathway of glycoprotein synthesis is localized preferentially to the photoreceptor layer of the retina, and may subserve the biosynthesis of rod cell glycoproteins (e.g. opsin).     

Cancer‐like metabolism of the mammalian retina

The retina, like many cancers, produces energy from glycolysis even in the presence of oxygen. This phenomenon is known as aerobic glycolysis and eponymously as the Warburg effect. In recent years, the Warburg effect has become an explosive area of study within the cancer research community. The expanding knowledge about the molecular mechanisms underpinning the Warburg effect in cancer promises to provide a greater understanding of mammalian retinal metabolism and has motivated cancer researchers to target the Warburg effect as a novel treatment strategy for cancer. However, if the molecular mechanisms underlying the Warburg effect are shared by the retina and cancer, treatments targeting the Warburg effect may have serious adverse effects on retinal metabolism. Herein, we provide an updated understanding of the Warburg effect in mammalian retina.     

糖尿病大鼠视网膜内皮素-1的表达

目的观察糖尿病大鼠视网膜内皮素-1(endothelin-1,ET-1)表达的影响。方法选取60只Wistar大鼠随机分为对照组和实验组。所有大鼠一次性腹腔注射0.1mol.L1链脲佐菌素诱发糖尿病模型。分别于成模后2周、4周、6周采用ADP酶视网膜铺片及免疫组织化学法分别观察视网膜血管的改变及检测视网膜ET-1的表达。结果与对照组相比,实验组大鼠6周时视网膜周边血管走形迂曲,神经节细胞排列紊乱,细胞数目减少,视网膜变薄。实验组大鼠视网膜ET-1表达随病程进展逐渐增强,4周、6周时平均积分光密度值分别为60.19±12.95、114.21±22.71,较同期对照组(15.35±8.38、15.22±4.71)增高,差异均有统计学意义(均为P<0.05)。结论随着糖尿病大鼠病程进展,视网膜ET-1表达逐渐增强。     

The location of insulin receptors in bovine retina and isolated retinal cells

Purpose: The binding of insulin to its cell-surface receptor is the sole means by which the hormone influences cellular activity. The location of insulin receptors in bovine retina and on isolated retinal cells was investigated to determine the specific cells sensitive to insulin.
Methods: Insulin receptors were located in frozen retinal sections prepared from enucleated bovine eyes, with polyclonal anti-insulin receptor antibodies using an immuno­peroxidase method. Isolated cells were obtained by enzymatic and physical dispersion of bovine retinal tissue. Insulin receptors on isolated cells were located by a monoclonal anti-insulin receptor antibody using an immunogold silver staining technique.
Results: Insulin receptors demonstrated a widespread dis­tribution throughout the bovine retina, being present in all retinal layers. A particular association with the plexiform layers and Müller cells was identified in the frozen sections. Consistent with these findings, insulin receptors were predominantly located on dendritic processes of isolated retinal neurones and on Müller cells.
Conclusions: The widespread distribution of retinal insulin receptors in the bovine retina supports the hypothesis that insulin has a role in regulating retinal activity. Insulin receptors associated with plexiform regions suggests that insulin may influence neural activity, while receptors on Müller cells indicate that insulin may have a role in metabolic or functional mechanisms in bovine retina.     

Localization of D, dopamine receptors in the chicken retina

Purpose: The localization of dopamine D| receptors (DIR) in the chicken retina was examined using an anti-human DI R. monoclonal antibody and PAP techniques. Results: A clear band of staining was seen in the outer plex-iform layer; as well as cellular staining in the outer-most part of the inner nuclear layer probably in a subset of horizontal cells. Many different amacrine cell bodies were labelled in the inner one-third of the inner nuclear layer. There was also extensive staining in the inner plexiform layer; which showed some striation. Occasional labelled ganglion cells were also detected. Conclusion: Localization of DI-dopamine receptors has     

Ets-1和VEGF在实验性糖尿病视网膜中的共表达

目的：阐明VEGF和Ets-1在糖尿病大鼠视网膜内的表达特点和分布特点。 方法：腹腔注射STZ诱导糖尿病大鼠模型。STZ注射后4wk处死动物,分离各组视网膜总蛋白进行Western　blot分析。将眼球固定后制成14μm厚的冰冻切片进行Ets-1和VEGF免疫荧光双标检测。 结果：Ets-1和VEGF在糖尿病大鼠视网膜内表达均显著增强,而且Ets-1和VEGF在视网膜内的分布特点相似,几乎在视网膜各层均共表达。 结论：Ets-1可能对VEGF诱导的糖尿病视网膜病变有促进作用。     

视网膜及视网膜色素上皮错构瘤1例

目的：报告1例视网膜及视网膜色素上皮错构瘤，并对其临床表现做出具体描述和分析，以期对眼科医师正确诊断本病有所裨益。方法：对1例诊断为“视网膜色素上皮病变”的患者跟踪随访5年，进行常规直接眼底检查、眼底荧光造影和B超检查。结果：本例患者视力在5年内从0．6下降至0．3，眼底镜检查和眼底荧光血管造影无明显变化。结论：视网膜及视网膜色素上皮错构瘤是临床少见病，病史、眼底表现和荧光造影表现是其确诊的依据。     

Cellular localization of the MPP4 protein in the mammalian retina

PURPOSE: Membrane protein, palmitoylated (MPP)-4 is a novel retina-specific member of the p55-like subfamily of membrane-associated guanylate kinases (MAGUKs). MAGUKs are known to act as scaffolding molecules for multiprotein complexes at specialized regions of the plasma membrane. The goal of this study was to characterize the MPP4 protein and to determine its location in the mammalian retina. METHODS: RT-PCR and 5' and 3' rapid amplification of cDNA ends (RACE) techniques were used to isolate and sequence the full-length bovine MPP4 cDNA. Polyclonal antisera against the bovine MPP4 protein were generated in rabbits immunized with synthetic peptides. Affinity-purified anti-MPP4 antibodies were used to investigate the properties and distribution of MPP4 in retina and transfected 293-Ebna cells by Western blot analysis and immunofluorescence microscopy. RESULTS: The full-length bovine MPP4 cDNA encodes a putative bovine MPP4 protein of 640 amino acids with a predicted molecular mass of 72.9 kDa. Affinity-purified anti-MPP4 antibodies specifically detected the MPP4 protein in extracts from retina and 293-Ebna cells transfected with the MPP4 cDNA. Immunofluorescence analyses revealed that both the bovine and porcine MPP4 proteins are localized in the connecting cilia and synaptic terminals of cone and rod photoreceptors. In addition, postsynaptic structures in the outer plexiform layer and three distinct bands in the inner plexiform layer were MPP4-positive. In porcine but not bovine retina, a subclass of cone bipolar cells were labeled with anti-MPP4. CONCLUSIONS: The concurrent presence of MPP4 in connecting cilia and synaptic structures suggests that MPP4 plays a role at membrane-cytoskeleton interfaces in distinct structural and functional compartments of bovine and porcine retinas. This work provides the basis for further investigations into the function of MPP4 as a retinal scaffolding molecule and its possible role in retinal disease.