骨髓间充质干细胞在视网膜色素变性大鼠视网膜下的分化

目的 研究骨髓间充质干细胞(MSCs)在视网膜色素变性(RP)大鼠体内的分化. 方法 Lewis大鼠腹腔注射3%NaIO3 100mg/kg,建立大鼠RP模型,将体外培养的MSCs植入视网膜下腔,用免疫荧光标记法对MSCs进行追踪,并观察术后第1、2、3、4、5周MSCs在该微环境中的分化.结果 术后第1周即可见MSCs位于视网膜色素上皮(RPE)层与光感受器细胞层,但全角蛋白(PCK)及Rhodopsin标记阴性,第3周开始可见MSCs在体内表达PCK及Rhodopsin.结论 MSCs植入RP模型大鼠视网膜下腔后可存活,主要分布于RPE层和视锥、视杆细胞层,并表达RPE细胞和光感受器细胞的表面标志.     

骨髓间充质干细胞在碘酸钠注射大鼠视网膜下的分化

目的 研究骨髓间充质干细胞(BMMSCs)在视网膜色素上皮(RPE)受损的大鼠模型眼中的分化情况.方法 体外培养Wistar大鼠的BMMSCs,用病毒上清液转染EGFP,移植到经静脉注射NaIO3破坏RPE细胞的大鼠的视网膜下腔,用免疫荧光标记的方法 对BMMSCs进行追踪并观察术后5周的分化情况.结果 BMMSCs的EGFP转染比例可达到76.9%,术后第5周可见BMMSCs位于视网膜下区域,未整合入神经视网膜层,并表达角蛋白(CK)、视紫红质(rhodopsin)和胶质纤维酸性蛋白(GFAP).结论 BMMSCs植入RPE受损伤的大鼠视网膜下腔后可存活,并表达RPE细胞、光感受器细胞和星形胶质细胞的特异性标志.     

大鼠骨髓间充质干细胞视网膜下移植的短期观察

目的探索骨髓间充质干细胞（MSCs）视网膜移植的可行性。方法采用贴壁筛选法分离、培养SD大鼠骨髓MSCs，将溴脱氧尿嘧啶（BrdU）标记的大鼠MSCs悬液经玻璃体腔注入大鼠视网膜下腔。术后14d处死大鼠，取新鲜眼球，连续冰冻切片，经BrdU单抗、FITC标记二抗和Rhodopsin单抗、Cy3标记二抗免疫荧光双重标记后，荧光显微镜下观察。结果荧光显微镜下可见移植后的MSCs主要分布于视网膜色素上皮层和视锥、视杆细胞层，未表达视网膜光感受器细胞的特异性抗原视紫红质。结论移植14d后MSCs可在视网膜下腔存活，主要分布于视网膜色素上皮层和视锥、视杆细胞层，未分化成视网膜光感受器细胞。     

大鼠骨髓间充质干细胞在脉络膜新生血管微环境中的分化

目的研究骨髓间充质干细胞（MSCs）在大鼠脉络膜新生血管（CNV）微环境中的分化。方法将体外培养的BN大鼠MSCs植入经氩激光诱导建立的CNV模型大鼠视网膜下腔,用免疫荧光标记的方法对MSCs进行追踪并观察术后1、2、3、4、5周MSCs在CNV微环境中的分化。结果术后第1周即可见MSCs位于CNV表面,但CD31标记阴性,第2周始可见MSCs在CNV内表达CD31阳性,第5周可见移行于光感受器的MSCs表达视紫红质。结论MSCs植入CNV模型大鼠视网膜下腔后可存活,并可向内皮细胞和光感受器细胞方向分化。     

兔胚胎全层视网膜移植至大鼠视网膜下的观察

视网膜色素变性(RP)是一组能导致进行性感光细胞变性和视觉障碍的遗传病症候群，目前尚无有效治疗方法。近年来研究表明视网膜移植是最接近临床应用治疗RP的方法。当RP进展到晚期，感光细胞和视网膜色素上皮(RPE)细胞都出现变性死亡，单独移植这两种成分都没有作用，此时病变视网膜的修复需要全层视网膜的移植。我们将青紫蓝兔胚胎全层视网膜移植到正常Wistar大鼠和视网膜变性RCS大鼠的视网膜下腔，观察移植物在宿主视网膜下腔的发育状况，从而探讨异种胚胎全层视网膜移植方法的可行性。     

视网膜色素上皮细胞诱导骨髓间充质干细胞分化为神经样细胞

目的：检测视网膜色素上皮细胞对骨髓间充质干细胞分化的调节作用。方法：体外培养人骨髓间充质干细胞（BMSC）和视网膜色素上皮（RPE）细胞。RPE细胞采用紫外线照射处理,而后与CFSE标记的BMSC共培养14d。并在共培养体系中加入牛眼视网膜提取物（BRE）以研究视网膜成分对此分化过程的影响。采用NSE,Nestin和GFAP抗体标记检测BMSC分化前后的表达特征。结果：BMSC在与RPE细胞共培养后,能够分化成为神经样细胞,并表达神经性细胞的特异性标记NSE．Nestin和GFAP。BRE能够显著促进共培养体系中BMSC向神经样细胞的分化。结论：RPE和BRE能够诱导BMSC分化为神经样细胞。     

兔眼虹膜色素上皮细胞自体视网膜下移植的研究

目的探讨兔眼虹膜色素上皮(IPE)细胞的自体移植技术并进行术后移植区的细胞形态学观察。方法通过虹膜全切法获取10只新西兰白兔的虹膜,采用酶-机械分离-酶消化的方法分离IPE细胞,用5溴脱氧尿嘧啶(5-Brdu)标记原代或一代的细胞。将标记过的IPE细胞悬液通过内路法分别植入对侧眼的视网膜下腔。术后2、4、6周摘除眼球对移植区进行光镜、电镜检查。结果经免疫学鉴定纯化培养了兔眼IPE细胞。术后光镜显示移植的IPE细胞成单层贴附在原始的视网膜色素上皮(RPE)细胞上。电镜结果证实移植的IPE细胞尖端微绒毛与光感受器外节连接,邻近的光感受器细胞显示正常结构。结论采用内路法可成功地将细胞悬液植入家兔视网膜下腔。6周内移植的自体IPE细胞在视网膜下腔存活,与原先的RPE细胞生长状态类似,邻近的光感受器细胞无形态改变。     

视网膜色素上皮细胞的功能及其抗新生血管作用

视网膜色素上皮（ retinal pigment epithelial,RPE）由一单层排列整齐的六角形细胞所组成,位于视网膜光感受器细胞层和脉络膜的Bruch's膜之间,其形态及功能的正常维持对于光感受器细胞至关重要,具有维持选择性转运营养和代谢物质、表达分泌多种生长因子、参与视循环、维持血－视网膜屏障和吞噬光感受器细胞脱落的外节盘膜等重要生理功能。 RPE细胞所构成的血－视网膜外屏障对于视网膜稳态的维持必不可少,其功能异常与许多眼底新生血管性疾病密切相关。本文对RPE正常结构、分泌生长因子、血－视网膜屏障功能、抗新生血管等方面进行综述。     

胚胎干细胞诱导分化视网膜细胞的方法新进展

视网膜变性疾病是引起视力丧失的重要原因,由于这类眼病的病因不明确、发病机制复杂,目前尚无有效的治疗方法.近年来,干细胞研究领域取得了突破性进展,干细胞具有分化为机体所有细胞的潜能,可以利用胚胎干细胞(ESCs)分化出各种视网膜细胞,这为视网膜变性疾病的治疗带来了新的曙光.ESCs治疗视网膜变性疾病至关重要的一步是将ESCs分化为视网膜光感受器细胞和视网膜色素上皮(RPE)样细胞.本文对自发诱导培养法、共培养法、细胞因子诱导法、单层贴壁诱导培养法和3D诱导培养法等ESCs分化为视网膜光感受器细胞和RPE细胞方法的最新进展进行综述.     

Müller细胞对大鼠光感受器变性及视功能的保护作用

目的以RCS视网膜色素变性大鼠为模型,研究经诱导产生神经干细胞特性的Müller细胞视网膜下腔移植对光感受器变性的保护作用。方法向6周龄VC大鼠玻璃体腔内注射神经毒素混合液（包含NMDA、kainate、FGF2和胰岛素）刺激视网膜Müller细胞。1周后取材分离Müller细胞体外原代培养。将细胞标记后,以每眼1×10^5个细胞密度移植到6周龄RCS大鼠右眼视网膜下腔,左眼分组注射正常Müller细胞和PBS作为同型对照及阴性对照。术后分别于第1、3、5、7周,行视网膜铺片、组织病理学及视觉电生理检查。结果培养的Müller细胞纯度可达96％以上,其中表达神经干细胞标志物的细胞占总细胞量的53％以上。组织病理学观察显示,在相同时间点移植眼保留的光感受器细胞数量明显较同型对照眼多,同型对照移植眼保留的光感受器细胞数量明显较阴性对照眼多。视网膜电图（ERG）检查结果与病理学结果相符。结论视网膜下腔移植经诱导产生神经干细胞特性的Müller细胞可以有效延缓RCS大鼠视网膜光感受器变性,为治疗视网膜变性疾病提供了新的途径。     

Differentiation of mesenchymal stem cell in the microenviroment of retinitis pigmentosa

AIM: To access the differentiation of rat mesenchymal stem cell (MSC) in the microenvironment of retinal degeneration induced by the administration of sodium iodate. METHODS: In-vitro cultured Lewis rat MSC were injected into the sub-retinal space of NaIO3 induced retinal degeneration rat eyes (30g/L NaIO3 100mg/kg). To observe the trace and differentiation of MSC by immuno-fluorescent method successively in 5 weeks after the surgery. RESULTS: The majority of the transplanted cells stay in retinal pigment epithelium layer and cones & rods layer. From the 2nd week after transplantation, the engrafted MSC express PCK and rhodopsin under fluorescent microscope. CONCLUSION: MSC can survive mainly in the outer layer of retina in the microenvironment of retinal degeneration and differentiate forward the RPE cell and photoreceptor.     

碘酸钠诱发的视网膜色素变性动物模型研究进展

视网膜色素变性(RP)是一组以视网膜色素上皮(RPE)和感光细胞的功能障碍或丧失为主要特征的致盲眼病,有很大的临床和遗传异质性.碘酸钠是抗代谢药物,可以选择性破坏RPE,它引起的视网膜病变与人类RP疾病的片状RPE缺损极为相似,因此常被用来制作RP疾病的模型.碘酸钠能诱发多种实验动物的RP模型,人们多使用单次碘酸钠注射的方法建立RP动物模型.由于碘酸钠诱发的RP动物模型的发病年龄和疾病进展均可人为操控,制备简单,病变稳定,周期短,且某些动物的RPE细胞在特殊条件下有再生的潜能,极有利于RP发病机制、药物或干/前体细胞治疗及再生医学方面的研究.目前有关碘酸钠诱发动物RP模型的研究和应用已有不少报道.本文根据国内外文献将碘酸钠诱发的RP动物模型的研究进展作一综述.     

Tetramethylpyrazine在视网膜色素上皮细胞变性及脉络膜血流和RPE细胞氧化应激中的作用

目的:研究1%Tetramethylpyrazine(TMP)在视网膜色素上皮细胞(RPE)变性,脉络膜血流和RPE细胞氧化应激中的作用。方法:在碘酸钠诱导的大鼠RPE变性研究中,1%TMP滴眼液预先处理1wk,3次/d,1wk后予碘酸钠舌下静脉注射,在2wk和4wk末,视网膜电图(ERG)测量c波。色素微球体技术分析高眼压状态下TMP对脉络膜血流的影响。Methylthiazoltetrazolium(MTT)分析TMP在各种氧化应激中对RPE的保护作用。结果:碘酸钠注射后2wk,碘酸钠组ERG的c波下降至对照组的36%(P<0.01)。4wk后,碘酸钠组下降至对照组的46%(P<0.01),而1%TMP+碘酸钠组下降至对照组的77%(P<0.01)。与碘酸钠组比较,1%TMP+碘酸钠组控制了67%的c波下降(P<0.05)。在脉络膜血流的测量中,30,60,和120min的结果显示,TMP显著增加脉络膜血流。在氧化应激部分,不同浓度的TMP在各种氧化应激损伤中,对RPE都有各种程度的保护作用。结论:浓度为1%Tetramethylpyrazine可以显著保护碘酸钠和氧化应激诱导的RPE变性,增加脉络膜血流,并可能在AMD的治疗中发挥作用。     

Effects of flavone on the oxidation-induced injury of retinal pigment epithelium cells

AIM: To investigate the effect of flavone on oxidation- induced injury in retinal pigment epithelium cells. METHODS: In in vivo studies, NaIO3-induced RPE degene- ration in rat eyes was treated with 0.5% flavone eye drops 3 times a day for 1 week before and 4 weeks after NaIO3 injection. At the end of 2 and 4 weeks, all rats were measured c-wave by electroretinogram (ERG). In in vitro studies, ARPE-19 cells were treated with hypoxia, H2O2, NaN3 and t-BHP to induce cell damages. MTT assay was used to measure the viable cells. RESULTS: The ERG c-wave results showed that flavone reversed NaIO3-induced injury at the end of 4 weeks. In vitro results showed flavone reversed the various oxidants-induced injuries in RPE cells. CONCLUSION: Flavone could prevent the RPE from oxidation- induced injury both in vivo and in vitro.     

Effect of naringenin on NaIO3-induced retinal pigment epithelium degeneration and laser-induced choroidal neovascularization in rats

AIM: To study the effects of naringenin eye drops on NaIO3-induced retinal pigment epithelium (RPE) degeneration and laser-induced choroidal neovascularization (CNV) in rat eyes. · METHODS: The 35mg/kg NaIO3-induced RPE degeneration was prevented by 10g/L naringenin eye drops 3 times a day for 7 days in advance of NaIO3 injection, and then 2 to 4 weeks thereafter, RPE function was measured with C-wave of electroretinogram (ERG). The laser-induced CNV rats were treated with laser to break the Bruch's membrane and the CNV formation was prevented by 10g/L naringenin eye drops instilled 3 times a day for 2 to 4 weeks. The CNV formation was measured with fluorescein angiography (FA) and flat mount. · RESULTS: Two weeks after NaIO3 injection, the amplitude of ERG C-wave fell markedly in NaIO3 group to 53% of normal group (P <0.01). No apparent difference was observed in naringenin+NaIO3 group. Four weeks later, the NaIO3 group fell to 37% of normal group (P <0.01), while the naringenin+ NaIO3 group fell to only 57% of normal group (P <0.01). There was a 52% reversal of the ERG C-wave by naringenin as compared to NaIO3 treated group (P <0.05). Two weeks and four weeks after laser treatment, naringenin reduced the CNV formation to 53% and 49% of control group (100%) measured by FA (P <0.01). Four weeks after laser treatment, naringenin reduced the CNV formation by 47% as compared to control group measured with flat mount(P <0.01). · CONCLUSION: Naringenin can significantly protect RPE from NaIO3 induced degeneration and also prevent CNV formation.     

Naringenin在碘酸钠诱导的视网膜色素上皮细胞变性和激光诱导的脉络膜新生血管鼠模型中的作用

目的:研究naringenin滴眼对碘酸钠诱导的大鼠视网膜色素上皮(retinal pigment epithelium,RPE)变性以及对激光诱导的脉络膜新生血管(choroidal neovascularization,CNV)的作用。方法:10g/Lnaringenin滴眼液预先处理1wk(3次/d),1wk后予35mg/kg碘酸钠舌下静脉注射诱导大鼠RPE变性,在2wk和4wk末,视网膜电图(electroretinogram,ERG)测量C波。另预处理1wk(3次/d),在2wk和4wk末用荧光素血管造影(fluorescein angiography,FA)和荧光显微镜测量CNV面积。结果:碘酸钠注射后2wk,碘酸钠组ERG的C波下降至对照组的53%(P<0.01)。而naringenin+碘酸钠组则无明显变化。4wk后,碘酸钠组下降至对照组的37%(P<0.01),而naringenin+碘酸钠组下降至对照组的57%(P<0.01)。与碘酸钠组比较,naringenin+碘酸钠组控制了66%的C波下降(P<0.05)。35mg/kgnaringenin组FA测量的CNV面积2,4wk末分别是对照组的53%和49%(P<0.01)。4wk后naringenin组荧光显微镜测量的CNV面积是对照组的47%(P<0.01)。结论:10g/Lnaringenin可以显著保护碘酸钠诱导的RPE变性,也能减小CNV的形成。     

黄酮对视网膜色素上皮细胞氧化损伤的保护作用

目的:观察黄酮对氧化剂所诱导的视网膜色素上皮细胞(RPE)的保护作用。方法:在体研究中,预先给予5g/L黄酮滴眼液(3次/d),1wk后舌下静脉注射NaIO3诱导大鼠RPE变性,在2和4wk末,采用视网膜电图(ERG)测量C波。离体研究中,采用缺氧、H2O2、NaN3和t-BHP诱导RPE细胞损伤,并用MTT法检测细胞的存活率。结果:ERG的C波结果表明,第4wk末,黄酮抑制了由NaIO3诱导的大鼠RPE变性。离体研究结果表明,黄酮对多种氧化剂所诱导的RPE细胞损伤具有保护作用。结论:黄酮对氧化诱导的在体和离体视网膜色素上皮细胞均具有保护作用。     

碘酸钠诱导非渗出型年龄相关性黄斑变性模型的研究(英文)

目的:研究10g/L胼酞嗪滴眼液对剂量为35mg/kg的NaIO3诱导的大鼠RPE变性的对抗作用。方法:经舌下静脉予Brown Norway大鼠分别注射不同剂量的NaIO3及生理盐水,注射3,7,14及28d后测量ERG的a、b、c、FO及LP波,同时进行眼底彩照和眼底荧光血管造影检查。用光学显微镜或自体荧光平片对部分大鼠进行组织学研究。在体外培养RPE-19细胞,观察不同浓度的NaIO3对细胞的影响并测其细胞增殖率。经舌下静脉予BrownNorway大鼠注射剂量为35mg/kg的NaIO3。NaIO3组大鼠注射NaIO3后用生理盐水点眼,10g/L胼酞嗪+NaIO3组大鼠注射NaIO3后用10g/L胼酞嗪滴眼液点眼,对照组不注射NaIO3,用生理盐水点眼,皆为3次/d,连续点4wk,然后测ERGc波。结果:注射NaIO3后,高剂量组如30、40和60mg/kgNaIO3组的各种ERG波的振幅明显降低,低剂量组则变化不大。眼底彩照显示注射NaIO3后3d30mg/kg组出现部分视网膜坏死,视网膜坏死程度与注射后时间及注射量呈正相关,低剂量组没有明显改变。平片显示,注射NaIO3后3d30mg/kg组及更高剂量组单层RPE细胞出现坏死。组织学研究提示,注射NaIO330mg/kg组和低剂量组未发现明显变化。体外实验发现,浓度≥30mg/LNaIO3组RPE-19细胞增殖率降低。注射剂量为35mg/kgNaIO3后4wk,和对照组相比,NaIO3组大鼠ERGc波显著降低到对照组的31%(P<0.01)。10g/L胼酞嗪+NaIO3组和NaIO3组相比,大鼠ERGc波显著升高到对照组的50%(P<0.05)。结论:NaIO3诱导的PRE细胞凋亡受剂量和时间的双重影响。剂量为30~40mg/kgNaIO3适用于非渗出型年龄相关性黄斑变性的体内造模。胼酞嗪可能延缓非渗出型年龄相关性黄斑变性的发展进程,可能用于治疗非渗出型年龄相关性黄斑变性。     

Protective effect of hepatocyte growth factor against degeneration of the retinal pigment epithelium and photoreceptor in sodium iodate-injected rats

PURPOSE: To investigate the possible protective effect of hepatocyte growth factor (HGF) against degeneration of photoreceptors and retinal pigment epithelium (RPE) in vivo. METHODS: Sprague-Dawley (SD) rats received an intravitreal injection of HGF in the right eye. The left eye was injected with vehicle as a control. Two days after the intravitreal injections, rats were administered 40 mg/kg of sodium iodate (NaIO3) intravenously. Scotopic ERGs were elicited by different stimulus intensities with a maximum luminance of 0.84 log cds/m2. To evaluate RPE function, the azide response was evoked by intravenous injection of 0.1 mg sodium azide. These electrophysiological measurements were conducted on days 4, 7, 14, and 28 after the NaIO3 injections. After recording ERGs or azide response, animals were sacrificed for quantification of the histological change and immunohistochemical analysis using antibodies against RPE 65. RESULTS: The threshold for the scotopic b-wave was significantly lower in HGF-treated eyes than in untreated control eyes (p < 0.005), and maximum b-wave amplitudes (Vbmax) were significantly larger in HGF-treated eyes (p < 0.05) across all experimental time points after NaIO3 injection. Azide response amplitudes were significantly larger in the HGF-treated eyes than in the untreated eyes (p < 0.05). The structure of the outer retina was preserved to a greater degree in the HGF-treated eyes than in the untreated eyes (p < 0.05). Immunohistochemical analysis demonstrated that irregular alignment of the outer nuclear layer was confined to the retinal area that was not stained with RPE 65. CONCLUSIONS: Our results indicated that an intravitreal injection of HGF provided significant protection against degeneration of the photoreceptor and RPE induced by systemic administration of NaIO3. This suggests that HGF could be used as a therapeutic agent for degeneration of photoreceptors as well as RPE.     

Tetramethylpyrazine在视网膜色素上皮细胞变性及脉络膜血流和RPE细胞氧化应激中的作用

目的：研究1% Tetramethylpyrazine （TMP）在视网膜色素上皮细胞（RPE）变性,脉络膜血流和RPE细胞氧化应激中的作用.方法：在碘酸钠诱导的大鼠RPE变性研究中,1%TMP滴眼液预先处理1wk,3次/d,1wk后予碘酸钠舌下静脉注射,在2wk和4wk末,视网膜电图（ERG）测量c波.色素微球体技术分析高眼压状态下TMP对脉络膜血流的影响.Methylthiazoltetrazolium （MTT）分析TMP在各种氧化应激中对RPE的保护作用.结果：碘酸钠注射后2wk,碘酸钠组ERG的c波下降至对照组的36%（P〈0.01）.4wk后,碘酸钠组下降至对照组的46%（P〈0.01）,而1% TMP ＋碘酸钠组下降至对照组的77%（P〈0.01）.与碘酸钠组比较,1%TMP ＋碘酸钠组控制了67%的c波下降（P〈0.05）.在脉络膜血流的测量中,30,60,和120min的结果显示,TMP显著增加脉络膜血流.在氧化应激部分,不同浓度的TMP在各种氧化应激损伤中,对RPE都有各种程度的保护作用.结论：浓度为1% Tetramethylpyrazine可以显著保护碘酸钠和氧化应激诱导的RPE变性,增加脉络膜血流,并可能在AMD的治疗中发挥作用.