Expression of a fusion protein of human ciliary neurotrophic factor and soluble CNTF-Receptor and identification of its activity

Ciliary neurotrophic factor (CNTF) has pleiotropic actions on many neuronal populations as well as on glia. Signal transduction by CNTF requires that it bind first to CNTF R, permitting the recruitment of gp130 and LIF R, forming a tripartite receptor complex. Cells that only express gp130 and LIF R, but not CNTF R are refractory to stimulation by CNTF. On many target cells CNTF only acts in the presence of its specific agonistic soluble receptors. We engineered a soluble fusion protein by linking the COOH terminus of sCNTF R to the NH 2 terminus of CNTF. Recombinant CNTF/sCNTF R fusion protein (Hyper CNTF) was successfully expressed in COS 7 cells. The apparent molecular mass of the Hyper CNTF protein was estimated from western blots to be 75 kDa. Proliferation assays of transfected BAF/3 cells in response to CNTF and Hyper CNTF were used to verify the activity of the cytokines. The proliferative results confirmed that CNTF required homodimerization of the gp130, CNTF R and LIF R receptor subunit whereas Hyper CNTF required heterodimerization of the gp130 and LIF R receptor subunit. We concluded that the fusion protein Hyper CNTF had superagonistic activity on target cells expressing gp130 and LIF R, but lacking membrane bound CNTF R.

Effect of ciliary neurotrophic factor on activation of astrocytes in vitro

Objective To observe the activating effect of ciliary neurotrophic factor （CNTF） on astrocyte in vitro. Methods Astrocytes cultured purely from newborn rats. Cerebral cortex was raised in normal and serum deprivation condition with different concentrations （in ng/ml： 0, 2, 20, or 200） of CNTF. After cultured for 24 h, the shape and the cell cycle of astrocytes were examined by immunocytochemistry and flow cytometer, respectively. Results The immunoactivity of glial fibrillary acidic protein （GFAP） and the nuclear size of astrocytes were increased when CNTF was applied, whether cells were cultured in medium with or without serum. CNTF promoted astrocytes to enter the cell cycle in medium with serum, but had no this effect in medium without serum. Conclusion In medium without serum, astrocytes could differentiate into activated state ceils with CNTF application, but could not proliferate; in medium with serum, astrocytes could proliferate with aid of CNTF.

Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group 〉 chemically extracted acellular nerve graft ＋ ciliary neurotrophic factor group 〉 chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone.

Biomechanical analysis of optic nerve injury treated by compound light granules and ciliary neurotrophic factor

In this study, rabbit models of optic nerve injury were reproduced by the clamp method. After modeling, rabbit models were given one injection of 50 ng recombinant human ciliary neurotrophic factor into the vitreous body and/or intragastric injection of 4 g/kg compound light granules containing Radix Angelicae Sinensis and Raidix Paeoniae Alba at 4 days after modeling, once per day for 30 consecutive days. After administration, the animals were sacrificed and the intraorbital optic nerve was harvested. Hematoxylin-eosin staining revealed that the injured optic nerve was thinner and optic nerve fibers were irregular. After treatment with recombinant human ciliary neurotrophic factor, the arrangement of optic nerve fibers was disordered but they were not markedly thinner. After treatment with compound light granules, the arrangement of optic nerve fibers was slightly disordered and their structure was intact. After combined treatment with recombinant human ciliary neurotrophic factor and compound light granules, the arrangement of optic nerve fibers was slightly disordered and the degree of injury was less than after either treatment alone. Results of tensile mechanical testing of the optic nerve showed that the tensile elastic limit strain, elastic limit stress, maximum stress and maximum strain of the injured optic nerve were significantly lower than the normal optic nerve. After treatment with recombinant human ciliary neurotrophic factor and/or compound light granules, the tensile elastic limit strain, elastic limit stress, maximum stress and maximum strain of the injured optic nerve were significantly increased, especially after the combined treatment. These experimental findings indicate that compound light granules and ciliary neurotrophic factor can alleviate optic nerve injury at the histological and biochemical levels, and the combined treatment is more effective than either treatment alone.

Protective effects of ciliary neurotrophic factor on the retinal ganglion cells by injure of hydrogen peroxide

AIM： To explore the effect of ciliary neurotrophic factor （CNTF） on retinal ganglion cell （RGC）-5 induced by hydrogen peroxide （H2O2）. METHODS： After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H2O2 from 50 to 150 μmol/L at four time points （0.5, 1, 1.5 and 2h） to select the concentration and time point for H2O2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells （BMSCs） for co-culture with RGC-5. RESULTS： Compared to the control group, H2O2 led to RGC-5 death closely associated with concentrations and action time of H2O2 and we chose 125 μmol/L and 2h to establish the H2O2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION： Both the two administration routes of CNTF have effects on RGC-5 cells induced by H2O2. If their own advantages were combined, there may be a better administration route.

Influence of endogenous ciliary neurotrophic factor on neural differentiation of adult rat hippocampal progenitors

Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.

In vitro neuroprotective effects of ciliary neurotrophic factor on dorsal root ganglion neurons with glutamate-induced neurotoxicity

Ciliary neurotrophic factor has neuroprotective effects mediated through signal transducer and Janus kinase（JAK） 2/activator of transcription 3（STAT3） and phosphatidylinositol 3-kinase（PI3 K）/Akt signaling pathways.Whether ciliary neurotrophic factor is neuroprotective for glutamate-induced excitotoxicity of dorsal root ganglion neurons is poorly understood.In the present study,the in vitro neuroprotective effects of ciliary neurotrophic factor against glutamate-induced excitotoxicity were determined in a primary culture of dorsal root ganglion neurons from Wistar rat embryos at embryonic day 15.Whether the JAK2/STAT3 and PI3 K/Akt signaling pathways were related to the protective effects of ciliary neurotrophic factor was also determined.Glutamate exposure inhibited neurite outgrowth,cell viability,and growth-associated protein 43 expression and promoted apoptotic neuronal cell death,all of which were reversed by the administration of exogenous ciliary neurotrophic factor.Additionally,preincubation with either JAK2 inhibitor AG490 or PI3 K inhibitor LY294002 blocked the neuroprotective effect of ciliary neurotrophic factor.These data indicate that the two pathways JAK2/STAT3 and PI3 K/Akt play major roles in mediating the in vitro neuroprotective effects of ciliary neurotrophic factor on dorsal root ganglion neurons with glutamate-induced neurotoxicity.

Effect of ciliary neurotrophic factor on bcl-2 and c-jun gene and protein expression in cultured retinal nerve cells

BACKGROUND：In various retinal neurodegenerative animal models,ciliary neurotrophic factor （CNTF） exhibits prominent neuroprotective effects on retinal nerve cells.Bcl-2 is an anti-apoptotic protein.c-Jun is upregulated and phosphorylated in the activated c-Jun N-terminal kinase pathway,which subsequently mediates apoptosis.However,the effect of CNTF on Bcl-2 and c-Jun expression in retinal nerve cells remains unclear.OBJECTIVE：To determine the dynamic changes in retinal nerve cell apoptosis,as well as bcl-2 and c-jun gene and protein expression,following a single dose of CNTF in a short period of time.DESIGN,TIME AND SETTING：A single-blind,randomized,controlled,in vitro experiment was performed at the Central Laboratory of Beijing Tongren Hospital from May 2008 to April 2009.MATERIALS：Neonatal bovine retinal nerve cells （Chinese Holstein）,recombinant human CNTF （PeproTech,Rocky Hill,NJ,USA）,rabbit polyclonal anti-Bcl-2 and c-Jun antibodies （Abeam,Cambridge,UK）,fluorescein isothiocyanate-conjugated annexin V/propidium iodide kit （BioVision,Mountain View,CA,USA）,real time polymerase chain reaction instrument （ABI,Foster City,CA,USA）,and flow cytometer （BD FACSCalibur,Franklin Lakes,NJ,USA）.METHODS：Neonatal bovine retinal cells from passage 2 were cultured for 3 days and incubated with,or without,50 ng/mL CNTF （control）.MAIN OUTCOME MEASURES：Cell apoptosis was detected via Annexin V-FITC/PI double-staining and flow cytometry.bcl-2 and c-jun mRNA and protein expression were detected by quantitative real time polymerase chain reaction and western blot analysis.RESULTS：The proportion of late-stage apoptotic cells was significantly decreased at 2,4,and 6 days after CNTF treatment compared with the control group （P 〈 0.01）.CNTF did not alter bcl-2 mRNA expression at the three time points,but significantly increased Bcl-2 protein expression at 2 and 4 days （P 〈 0.01）.c-jun mRNA expression was significantly decreased 4 days after CNTF treatment （P〈 0.01）.In addition,c-Jun protein expression was slightly increased at 4 days （P〈 0.01）,but decreased at 6 days,compared with the control group （P〈 0.05）.CONCLUSION：A single dose of CNTF （50 ng/mL） upregulated Bcl-2 protein and downregulated c-jun mRNA expression,followed by a parallel,but lagged,change in c-Jun protein production in cultured neonatal bovine retinal nerve cells.These results suggested that CNTF reduces retinal nerve cell apoptosis by modifying Bcl-2 and c-Jun expression.

Inhibition of ciliary neurotrophic factor in a rat model of transected spinal cord

Ciliary neurotrophic factor （CNTF） dramatically increases following spinal cord injury and participates in the repair process, although some studies have shown that CNTF plays a role in promoting glial scar formation following spinal cord injury. The antibody closure model can be used to inhibit CNTF expression following spinal cord injury, thereby furthering the understanding of the role of CNTF in spinal cord injury repair. In the present experiment, spinal catheters were placed in the vertebral canal of spinal cord transected rats, and CNTF antibodies were injected following fixation of the paraspinal muscle catheter. At 24 hours after a single CNTF antibody injection, CNTF expression decreased in the thoracic and lumbar spinal cord and recovered to normal levels by 48 72 hours. CNTF antibody treatment can effectively block endogenous CNTF expression in the thoracic and lumbar spinal cord during an interval of less than 24 hours in transected rats.

Induction of Differentiation of Mesenchymal Stem Cells into Retinal Pigment Epithelial Cells for Retinal Regeneration by Using Ciliary Neurotrophic Factor in Diabetic Rats

Diabetic retinopathy(DR)is a common cause of blindness all over the world.Bone marrow mesenchymal stem cells(BMSCs)have been considered as a promising strategy for retinal regeneration in the treatment of DR.However,the poor viability and low levels of BMSCs engraftment limit the therapeutic potential of BMSCs.The present study aimed to examine the direct induction of BMSCs differentiation into the cell types related to retinal regeneration by using soluble cytokine ciliary neurotrophic factor(CNTF).We observed remarkably increased expression of cellular retinaldehyde-binding protein(CRALBP)and retinoid isomerohydrolase(RPE65)in BMSCs treated with CNTF in vitro,indicating the directional differentiation of BMSCs into the retinal pigment epithelium(RPE)cells,which are crucial for retinal healing.In vivo,the diabetic rat model was established by use of streptozotocin(STZ),and animals treated with BMSCs+CNTF exhibited better viability and higher delivery efficiency of the transplanted cells than those treated with BMSCs injection alone.Similar to the in-vitro result,treatment with BMSCs and CNTF combined led to the differentiation of BMSCs into beneficial cells(RPE cells),and accelerated retinal healing characterized by the activation of rod photoreceptor cells and phagocytosis function of RPE cells.In conclusion,CNTF contributes to the differentiation of BMSCs into RPE cells,which may help overcome the current stem cell therapy limitations in the field of retinal regeneration.

Construction of Zebrafish Mutants of CNTF Gene Using CRISPR/Cas9 Genome Editing Technology

Background: The prevalence of Parkinson’s disease (PD), a chronic and progressive neurodegenerative disorder, is projected to increase twofold by 2030. Leucine-rich repeat kinase 2 (LRRK2) is the most commonly observed gene in both familial and sporadic PD cases. Notably, there is a substantial augmentation in motor activity during both larval and adult stages of zebrafish lacking the lrrk2 gene. Nevertheless, the precise genetic abnormalities accountable for eliciting these phenotypes in zebrafish are yet to be elucidated. Methods: Real-time polymerase chain reaction (PCR) was conducted on zebrafish larvae at 6 days post fertilization (dpf) belonging to both the wild-type and lrk2(-/-) groups. Guide RNA was designed and subsequently employed in the PCR process. Electrophoresis was performed to facilitate identification. Results: The expression of CNTF mRNA was significantly diminished in lrrk2(-/-), in comparison to the wildtype zebrafish larvae. This finding implies that CNTF may have crucial implications in the regulated functioning of lrrk2, which is widely acknowledged as the predominant genetic factor contributing to hereditary PD. The primers for CNTF DNA were meticulously designed, and the electrophoresis results of the PCR product were subsequently presented. The wild type zebrafish embryos were meticulously prepared for micro-injection, and the resulting efficiency identification displayed the presence of the mutant PCR product, which exhibited the presence of several debris. Conclusions: The present study demonstrates the successful generation of CNTF mutant zebrafish using the CRISPR/Cas9 genome editing technique. Further investigations are necessary to deepen our understanding of the exogenous CNTF gene’s functionality.

TAT-tCNTF融合蛋白对Aβ_(25-35)诱导SH-SY5Y细胞损伤的保护作用

目的确定TAT-tCNTF融合蛋白能够透过细胞膜进入细胞内,并研究其对Aβ诱导SH-SY5Y细胞损伤的保护作用。方法重组PCR获得人截短型CNTF基因后,与pBV220-TAT载体连接,在大肠杆菌中表达,细胞免疫荧光方法检测TAT蛋白运载融合蛋白穿过SH-SY5Y细胞膜的作用,Aβ25-35诱导SH-SY5Y细胞产生神经毒性,采用MTT(四甲基偶氮唑盐)法检测融合蛋白对细胞存活率的影响,Heochst33342/PI荧光双染法进行细胞凋亡和坏死的形态学观察,并进行LDH释放分析进一步检测TAT-tCNTF对细胞损伤后的保护作用。结果成功构建pBV220-TAT-tCNTF表达载体,Western blot结果表明重组融合蛋白可以与CNTF抗体特异性结合,细胞免疫荧光方法显示TAT-tCNTF能大量进入细胞,而rhCNTF只有微量进入细胞。对Aβ25-35诱导损伤的SH-SY5Y细胞MTT、Heochst33342/PI荧光双染法及LDH分析都表明TAT-tCNTF能明显提高细胞的存活率。结论TAT-tCNTF融合蛋白可以跨越细胞膜,能够保护Aβ25-35诱导损伤的SH-SY5Y细胞,具有促进细胞生存生长的活性。

头顶一颗珠提取液对大鼠脊髓损伤后CNTF及CNTFRα表达的影响

目的观察百合科延龄草属植物头顶一颗珠干燥根茎提取液对大鼠急性脊髓损伤模型睫状神经营养因子(CNTF)及其受体(CNTFRα)表达的影响。方法健康成年Wistar大鼠45只,随机分为对照组、模型组及实验组(n=15),模型组及实验组参照Allen's法建立脊髓损伤模型,对照组不损伤脊髓。实验组于术前2周开始给予头顶一颗珠提取液灌胃,模型组和对照组给予同剂量蒸馏水灌胃。分别于伤后1d、7d,14d处死动物,取脊髓组织行HE染色观察组织病理学改变,Nissl染色观察Nissl小体的变化,并通过免疫组化染色、Western-blotting及RT-PCR检测观察CNTF、CNTFRαm RNA及蛋白的表达情况。结果 HE染色显示实验组脊髓结构比较清晰,神经细胞水肿、坏死较模型组减轻;Nissl染色见模型组和实验组损伤后各时相点脊髓前角运动神经元尼氏小体减少或消失,实验组尼氏小体减少程度较模型组明显减轻;免疫组化染色显示各组脊髓均有CNTF、CNTFRα蛋白表达。RT-PCR检测显示伤后7、14d模型组及实验组脊髓组织中CNTF、CNTFRαm RNA表达水平均明显高于对照组,且实验组明显高于模型组。Western blotting检测显示模型组伤后14d及实验组伤后7、14d脊髓组织中CNTF、CNTFRα蛋白表达水平明显高于对照组,且实验组伤后14d的表达水平均明显高于模型组。结论头顶一颗珠能上调脊髓组织中CNTF、CNTFRα的表达,对脊髓损伤有一定的保护作用。

大鼠视神经损伤后视网膜CNTF及CNTFRα mRNA的表达

目的研究视神经损伤后睫状神经营养因子及其受体在大鼠视网膜中的表达变化。方法采用钳夹法制作大鼠视神经损伤模型。分别于伤后1、3、7、14、28d取眼球,以正常大鼠视网膜为对照,提取视网膜组织RNA,运用RT-PCR检测视神经损伤后CNTF和CNTFRαmRNA的表达变化。结果在正常视网膜中存在CNTF和CNTFRαmRNA的表达,视神经损伤后CNTF和CNTFRαmRNA表达量逐渐增加,第7d达到最高,第14d下降,具有统计学意义(P<0.01)。28dCNTF表达仍高于正常组(P<0.01)。结论视神经损伤刺激了视网膜细胞表达CNTF和CNTFRα增加,可能是视网膜神经元自我保护的一种反应。

联合应用NGF和CNTF对大鼠坐骨神经损伤后功能恢复的影响

目的 探讨联合应用神经营养因子 (Nervegrowthfactor ,NGF)和睫状神经营养因子 (Ciliaryneurotrophicfactor ,CNTF)对大鼠坐骨神经损伤后再生及功能恢复的影响。方法 用硅胶管桥接 12 0只大鼠左侧坐骨神经长 6mm缺损 ,随机分为 4组 ,分别行NGF +CNTF、CNTF、NGF、生理盐水 (NS)靶肌肉注射。术后行坐骨神经功能指数 (SFI)、电生理检测、病理学检查。结果 联合应用NGF和CNTF组SFI恢复率、各项电生理及轴突图像分析指标明显优于单独用药组。结论 联合应用NGF和CNTF可明显促进大鼠坐骨神经损伤后再生与功能恢复。

视神经损伤后视网膜CNTF及CNTFRα免疫组织化学检测

目的研究视神经损伤后睫状神经营养因子(ciliaryneurotrophicfactor,CNTF)及其受体(ciliaryneurotrophicfactorrecepterα,CNTFRα)在大鼠视网膜中的定位表达变化。方法采用钳夹法制作大鼠视神经损伤模型。分别于伤后1d、3d、7d、14d、28d取眼球,以正常大鼠视网膜为对照,运用免疫组织化学方法检测视神经损伤后CNTF和CNTFRα的表达变化。结果在正常对照组中,由视锥视杆细胞外节组成的视网膜视锥视杆细胞层均有大量的CNTF及CNTFRα存在,在其它各层也存在散在颗粒状分布的CNTF及CNTFRα。视神经损伤后,CNTF及CNTFRα在视网膜各层显著增加,并呈弥漫性分布,在损伤后3d、7d、14d与正常对照组比较相差非常显著(P<0.01)。损伤后7d,CNTF及CNTFRα在视网膜各层表达达高峰,在损伤后28d2者的表达均显著高于正常对照组(CNTF:P=0.02<0.05;CNTFR:P=0.015<0.05)。结论视神经不全损伤导致了视网膜CNTF和CNTFRα表达量的增加和分布的改变,可能是视网膜神经元损伤后自我保护的一种反应。

部分背根切断对备用背根节神经元CNTF、PDGF表达的影响

目的 研究部分去背根对备用背根节神经元睫状神经营养因子 (CNTF)和血小板源性生长因子(PDGF)表达的影响。方法 制作猫备用背根模型 ,分别在 3d、7d及 14 d时取备用背根节用 CNTF抗血清、PDGF抗血清行免疫组织化学 ABC法染色。分别计数各组阳性神经元总数以及大、中小阳性神经元的数量。结果 两因子在备用背根节的大、中小神经元均有表达。 CNTF阳性神经元总数及中小阳性神经元数均在 3d时明显减少 (P<0 .0 5 ) ,7d、14 d时与正常比较无差异 ,大阳性神经元在各个时间段与正常相比无差异。PDGF阳性神经元总数及中小阳性神经元数在 3d、7d时均较正常显著减少 (P<0 .0 5 ) ,14 d时与正常无差异 ,大阳性神经元数各个时间段均无差异。结论 部分背根切断对备用背根节内不同神经元表达 CNTF、PDGF有不同的影响。

CNTF对应激大鼠行为障碍和海马CA1神经元损害的作用

实验采用 ｏｐｅｎ ｆｉｅｌｄ测定、 Ｎｉｓｓｌ染色、 Ｂｉｅｌｓｃｈｏｗｓｋｙ－Ｇｒｏｓ－Ｌａｗｒｅｎｔｊｅｗ染色和常规透射电镜技术，观察急性和慢性足底电击应激大鼠的ｏｐｅｎ ｆｉｅｌｄ行为和海马ＣＡ１神经元形态的变化，及双侧海马注射睫状神经营养因子（ＣＮＴＦ）对它的影响。结果表明，急性应激大鼠ｏｐｅｎ ｆｉｅｌｄ行为活动增加，海马ＣＡ１神经元形态无明显变化；慢性应激大鼠ｏｐｅｎ ｆｉｅｌｄ行为活动减少，海马ＣＡ１神经元出现明显的损伤性形态变化；睫状神经营养因子对对照组大鼠和急性应激大鼠的ｏｐｅｎ ｆｉｅｌｄ行为和海马ＣＡ１神经元形态均无明显作用，但可显著减轻慢性应激大鼠海马ＣＡ１神经元损伤程度，改善其行为障碍。实验结果提示睫状神经营养因子可能通过保护海马神经元从而改善慢性应激大鼠的行为障碍。

逆转录病毒介导的人CNTF在嗅神经鞘细胞中的表达及其对神经细胞存活和突起生长的影响

目的 研究含有睫状神经营养因子 (CNTF)表达调控系统修饰的嗅神经鞘细胞 (OECs)对神经细胞存活和突起生长的影响。 方法 通过基因克隆 ,用KpnⅠ +XbaⅠ将pcDNA3 S(NGF信号肽 ) hCNTF质粒中含有NGF信号肽的CNTF切下 ,插入逆转录病毒表达载体pRev TRE中。酶切鉴定后 ,将其与本系统的调控质粒pRev Tet On转入Ecopack 2 93细胞进行病毒包装 ,制备重组缺陷型hCNTF和Tet On逆转录病毒感染原代培养的大鼠OECs,用不同浓度的强力霉素诱导 ,以Western blot法对hCNTF的表达培养上清进行检测。将转染hCNTF的OECs与新生 2d大鼠DRG联合培养 ,用其上清培养视网膜节细胞 (RGCs)。经 β tubulin免疫组织化学染色后 ,分别测量DRG神经突起的长度并统计阳性RGCs数目。 结果 1 经HindⅢ和BamHⅠ酶切鉴定 ,pRev TRE S hCNTF重组体分别被切下 6 30bp和 4 0 0bp片段 ,插入子的方向和完整性经确认与预期相符。 2 以不同浓度强力霉素诱导hCNTF修饰的OECs ,其培养上清均有分子量约 2 4kD的hCNTF蛋白质的显著特异表达 ,此表达与强力霉素的浓度呈正相关。未诱导组和对照组未见明显蛋白带。 3 同单纯OECs(2 3 15± 4 7)、空载 (2 4 5 5± 5 8)、空白 (16 8± 6 5 )等对照组相比 ,经hCNTF转染的OECs上清组的存活RGC数显著?

超声微泡介导CNTF基因眼内转染对视神经损伤大鼠作用的研究

背景选择理想的基因载体是当前基因研究和治疗的前提与关键，超声微泡造影剂作为一种新型的基因载体，可安全、快速、有效地增强目的基因的转染和表达。目的观察超声微泡造影剂介导睫状神经营养因子（CNTF）基因转染视神经损伤大鼠对视功能及视网膜神经节细胞（RGCs）存活的影响。方法SD大鼠60只随机分为正常对照组、假伤组、单纯损伤组、单纯质粒组、质粒＋超声组、超声微泡组。采用钳夹大鼠右眼视神经法制作视神经损伤大鼠模型，然后各处理组大鼠分别接受相应的干预处理。质粒采用玻璃体腔注射法注入，超声则采用辐照法进行干预。造模前1d和损伤后第7天检测每组大鼠闪光视觉诱发电位（F—VEP），并于第7天处死各组大鼠。应用荧光金逆行标记法计数各组大鼠RGCs存活数，采用实时定量聚合酶链反应（real—timePCR）检测大鼠视网膜中CNTFmRNA的表达量。结果损伤后第7天，单纯损伤组大鼠F—VEPP．波的隐含时较单纯质粒组、质粒＋超声组和超声微泡组明显延长，超声微泡组P，波的隐含时短于单纯质粒组和质粒＋超声组，差异均有统计学意义（P〈0．05）。单纯质粒组、质粒＋超声组和超声微泡组F—VEPP，波的振幅均高于单纯损伤组，超声微泡组高于单纯质粒组和质粒＋超声组，差异均有统计学意义（P〈0．05）。超声微泡组大鼠与正常对照组比较P，波振幅降低，差异有统计学意义（P〈0．05）。单纯质粒组、质粒＋超声组和超声微泡组平均RGCs数目均明显高于单纯损伤组，超声微泡组平均RGCs数多于单纯质粒组和质粒＋超声组，但少于对照组及假伤组，差异均有统计学意义（P〈0．05）。超声微泡组CNTFmRNA表达量高于正常对照组、假伤组、单纯损伤组、单纯质粒组和质粒＋超声组，差异均有统计学意义（P〈0．05）。结论超声微泡能增强CNTF基因在眼内的转染及表达，对视神经损伤大鼠RGCs早期有明显的保护作用，可有效促进视功能的恢氪．