内皮素和bFGF对MC的促增殖作用及胰岛素的协同效应

采用３Ｈ－ＴｄＲ参入法,测定碱性成纤维细胞生长因子（ｂＦＧＦ）、胰岛素和内皮素－１（ＥＴ－１）对体外培养的大鼠肾小球系膜细胞（ＭＣ）增殖的影响,以及胰岛素与ｂＦＧＦ或ＥＴ－１促ＭＣ增殖的协同作用。结果表明,不同浓度的ｂＦＧＦ（５－２００ｎｇ／ｍｌ）和胰岛素（０．１－２．４Ｕ／ｍｌ）均显著升高ＭＣ的３Ｈ－ＴｄＲ参入值（ｃｐｍ值）（Ｐ＜０．０１）。ＥＴ－１对ＭＣ的ｃｐｍ值的影响依剂量不同呈现两种不同的效应,在１０－９－１０－７ｍｏｌ／Ｌ时,随着浓度的升高,ＭＣ的ｃｐｍ值明显升高（Ｐ＜０．０１）,并以１０－８ｍｏｌ／Ｌ作用最强;当升高到１０－６ｍｏｌ／Ｌ时,ＭＣ的ｃｐｍ值出现降低趋势。胰岛素与ｂＦＧＦ或低浓度ＥＴ－１（≤１０－８ｍｏｌ／Ｌ）共同作用于ＭＣ时,ＭＣ的ｃｐｍ值明显高于二者单独作用之和（Ｐ＜０．０１）,与高浓度ＥＴ－１（＞１０－７ｍｏｌ／Ｌ）共同作用于ＭＣ时,ＭＣ的ｃｐｍ值小于二者单独作用之和（Ｐ＞０．０５）。上述结果说明,胰岛素、ｂＦＧＦ和ＥＴ－１均能显著促进ＭＣ增殖;胰岛素与ｂＦＧＦ或低浓度的ＥＴ－１促ＭＣ增殖具有正协同作用,与高浓度ＥＴ－１呈现负协同作用。     

睫状神经营养因子的研究进展

睫状神经营养因子 (ＣｉｌｉａｒｙＮｅｕｒｏｔｒｏｐｈｉｃＦａｃ ｔｏｒ ,ＣＮＴＦ )最初是从鸡胚的眼组织睫状节中提取出来 ,因对睫状节神经元有营养作用并可维持鸡副交感神经节的存活而得名[1～ 3] 。ＣＮＴＦ属神经调节细胞因子家族中的一员 ,但不属于神经营养因子家族成员。至今 ,已发现ＣＮＴＦ具有广泛的生物学活性 ,如它对于感觉和运动神经元的分化、存活及功能维持均具有重要作用[1,4 ] 。本文就ＣＮＴＦ的结构、分布、生物学效应及其与脊髓损伤修复的关系作一综述。1.ＣＮＴＦ及其基因结构1 1　ＣＮＴＦ的结构ＣＮＴＦ最初由Ｈ…     

人睫状神经营养因子的原核表达,纯化及其生物效应

人睫状神经营养因子（ｈＣＮＴＦ）克隆入ｐＢＶ２２０中，在ＤＨ５α菌株中表达，重组蛋白以包含体的形式存在，表达量为菌体总蛋白的５０％左右。经比较发现用２ｍｏｌ／Ｌ脲洗涤包含体可溶解大量可溶性细菌蛋白，且包含体损失较小。在高浓度变性剂条件下进行ｓｅｐｈａｒｃｙｌＳ－２００凝胶过滤，解决了纯化中ｈＣＮＴＦ易聚合的问题，在低浓度变性剂条件下进行ＤＥＡＥ离子交换，有利于蛋白活性的保持。经两步纯化后得到均一性ｈＣＮＴＦ，纯度达９５％以上。在自然状态下使ｈＣＮＴＦ复性。纯化复性后的ｈＣＮＴＦ对无血清培养的鸡胚背根节神经元和脊髓腹角运动神经元有明显的维持存活和促进生长发育的生物效应。     

血小板生长因子(PDGF-BB)刺激体外培养兔肺动脉平滑肌细胞DNA和蛋白质合成

应用细胞培养、３Ｈ－ＴｄＲ和３Ｈ－Ｌｅｕｃｉｎｅ掺入方法,观察血小板生长因子ＢＢ（Ｐｌａｔｅｌｅｔ－ｄｅｒｉｖｅｄＧｒｏｗｔｈＦａｃｔｏｒＢＢ）对体外培养兔肺动脉平滑肌细胞ＤＮＡ和蛋白质合成的影响。结果表明：（１）当ＰＤＧＦ－ＢＢ浓度为１０ｎｇ／ｍｌ时,３Ｈ－ＴｄＲ掺入值已较对照组显著增高（６２６２．５±４１２．９ｖｓ８３３．５±１２４．０,Ｐ＜０．０５）;当ＰＤＧＦ－ＢＢ浓度为２０ｎｇ／ｍｌ时,３Ｈ－Ｌｅｕｃｉｎｅ掺入值亦较对照线显著增高（１０２１２．８±６３８．３ｖｓ７３４０．３±１１９７．９,Ｐ＜０．０５）。（２）ＰＤＧＦ－ＢＢ浓度在５－２５ｎｇ／ｍｌ范围内,３Ｈ－ＴｄＲ,３Ｈ－Ｌｅｕｃｉｎｅ掺入值与剂量直线相关（ｒＤＮＡ＝０．９７,ｒｐｒｏｔ＝０．９０Ｐ＜０．０５）。说明ＰＤＧＦ－ＢＢ刺激体外培养兔肺动脉平滑肌细胞ＤＮＡ和蛋白质合成。     

血小板生长因子（PDGF—BB）刺激体外培养兔肺动脉平滑肌细？…

应用细胞培养、＾３Ｈ－ＴｄＲ和＾３Ｈ－Ｌｅｕｃｉｎｅ掺入方法,观察血小板生长因子ＢＢ对体外培养兔肺动脉平滑肌细胞ＤＮＡ和蛋白质合成的影响。结果表明：（１）当ＰＤＧＦ－ＢＢ浓度为１０ｎｇ／ｍｌ时,＾３Ｈ－ＴｄＲ掺入值已较对照组显著提高（６２６２．５±４１２．９ｖｓ８３３．５±１２４．０,Ｐ〈０．０５）;当ＰＤＧＦ－ＢＢ浓度为２０ｎｇ／ｍｌ时,＾３Ｈ－Ｌｅｕｃｉｎｅ掺入值亦较对照线显著增高（１０２１２     

血小板第四因子保护造血前体细胞及其作用机制的研究

我们曾报道血小板第四因子（ＰＦ４）是巨核细胞形成的有效的抑制因子,它可以保护干细胞免遭５－ＦＵ的毒性作用。本研究中试比较ＰＦ４和ＴＧＦ－β１对人脐带血ＣＤ３４＾＋来源的ＭＫ的作用。ＰＦ４（５ｕｇ／ｍｌ）和ＴＧＦ－β（１ｎｇ／ｍｌ）在半固态凝块培养和悬浮培养中明显抑制人脐带血ＣＤ３４＾＋来源的ＭＫ的生长。用ＰＦ４处理的ＣＤ３４＾＋细胞在撒去ＰＥ４后仍能再生成集落,说明ＰＦ４的抑制作用的可逆性的。相反     

特异性血清中白介素1β放射免疫分析的建立及初步应用

人工重组的白细胞介素１β（ＩＬ－１β）多次免疫兔和逐鼠,获取高效价的兔抗ＩＬ－１β抗体。用氯氨Ｔ法制备＾１２５Ｉ标记ＩＬ１β,经ＳｅｐｈａｄｅｘＧ－２５纯化。该法测定范围０．０６－４ｎｇ／ｍｌ,批内和批间误差分别小于５％和１０％。正常人血清含量为０．２４±０．０８ｎｇ／ｍｌ（ｎ＝１３８）,人粒细胞系ＨＬ６０（１０＾６）细胞体外培养２４小时,不能检出上清液中ＩＬ－１β,钙离子载体Ａ２３１８７和磷脂酶     

人成纤维细胞系HF—91的建立及生物学特性

人胚胎胰腺结缔组织经分离培养成人成纤维细胞系ＨＦ－９１,传４０代。该细胞贴壁生长,具有密度依赖性抑制性质。它的生长依赖于成纤维细胞生长因子的存在,在１０ｎｇ／１００ｎｇ／ｍｌ浓度范围内,细胞生长与ｂＦＧＦ的浓度成正相关。细胞群体倍增时间２３．８±５．３ｈ。有丝分裂指数４９．３％±４．１％染色体众数２ｎ＝４６,占８７．５％±４．１％。染色体众数２ｎ＝４６,占８７．５％－９１．０％,乳酸脱氢酮同工酶Ｌ     

肿瘤坏死因子－α（TNF－α）及白细胞介素1β（IL1－β）对胶质增生的影响及机理

本文利用小鼠大脑机械损伤模型及体外培养的胶质细胞,采用同位素渗入法观察了细胞介素及其抗体对胶质细胞增生的影响。结果表明：体外培养时ＴＮＦ－α在浓度为１０～２００ｕ／ｍｌ培养液时均能促进胶质细胞增生（Ｐ＜０．０５）,ＩＬ１－β在浓度为５～２００ｕ／ｍｌ培养液时能促进胶质细胞增生,ＴＮＦ－α＋ＩＬ１－β其促进胶质细胞增生作用更强烈,ＴＮＦ－α抗体能完全阻断ＴＮＦ－α的促增生作用,部分阻断ＴＮＦ－α＋ＩＬ１－β的促增生作用。在体实验时,ＩＬ１－β及ＴＮＦ－α的作用与离体时相似,ＩＬ１－β及ＴＮＦ－α亦能促进胶质细胞增生,二者共同作用时促细胞增生作用更强。以上结果提示,外源性ＴＮＦ－α及ＩＬ１－β能促进中枢神经损伤后胶质细胞增生且具有协同作用。     

人睫状神经营养因子的原核高效表达

睫状神经营养因子(ciliary neurotrophic factor,CNTF)是神经生长因子家族之外的一种神经营养因子,由200个氨基酸组成,分子量约22.86kD,等电点6.00。CNTF对睫状副交感神经元、交感神经元、感觉神经元、视网膜神经节细胞、脊髓运动神经元、海马神经元等多种中枢及外周神经元有促存活作用。CNTF也是第一个被发现的能维持在体和离体脊髓运动神经元的存活及突起生长的神经营养因子,因此在神经创伤和神经退行性病变的诊断与治疗中有巨大的临床价值。由于CNTF在天然组织中含量甚微,故用基因工程     

人CNTF突变体(CNTFM)基因的克隆、表达和产物纯化及活性鉴定

采用PCR的方法对睫状神经营养因子(CNTF)基因进行改造,获得CNTF突变体基因(CNTFM) ,将CNTFM基因克隆入表达载体pBV2 2 0 ,在大肠杆菌BL 2 1(Gold)中进行了表达.目的蛋白占细胞总蛋白5 5 %左右,以包涵体形式存在,经Superdex 75凝胶过滤柱一步纯化和复性,获得纯度达90 %目的蛋白.纯化的重组CNTFM蛋白能促进培养的鸡胚背根神经节长出神经突起,能明显减轻实验小鼠的体重,表明CNTFM具有良好的体内、体外生物学活性,为开发新型高效的减肥药奠定了基础.     

Ciliary neurotrophic factor fused to a protein transduction domain retains full neuroprotective activity in the absence of cytokine-like side effects

Ciliary neurotrophic factor (CNTF) is a multifunctional cytokine that can regulate the survival and differentiation of many types of developing and adult neurons. CNTF prevents the degeneration of motor neurons after axotomy and in mouse mutant progressive motor neuronopathy, which has encouraged trials of CNTF for human motor neuron disease. Given systemically, however, CNTF causes severe side effects, including cachexia and a marked immune response, which has limited its clinical application. The present work describes a novel approach for administering recombinant human CNTF (rhCNTF) while conserving neurotrophic activity and avoiding deleterious side effects. rhCNTF was fused to a protein transduction domain derived from the human immunodeficiency virus-1 TAT (transactivator) protein. The resulting fusion protein (TAT-CNTF) crosses the plasma membrane within minutes and displays a nuclear localization. TAT-CNTF was equipotent to rhCNTF in supporting the survival of cultured chicken embryo dorsal root ganglion neurons. Local or subcutaneous administration of TAT-CNTF, like rhCNTF rescued motor neurons from death in neonatal rats subjected to sciatic nerve transection. In contrast to subcutaneous rhCNTF, which caused a 20–30% decrease in body weight in neonatal rats between postnatal days 2 and 7 together with a considerable fat mobilization in brown adipose tissue, TAT-CNTF lacked such side effects. Together, these results indicate that rhCNTF fused with the protein transduction domain/TAT retains neurotrophic activity in the absence of CNTFs cytokine-like side effects and may be a promising candidate for the treatment of motor neuron and other neurodegenerative diseases.     

外源性重组人睫状神经营养因子抑制成人成肌细胞的体外分化

为探讨外源性重组人睫状神经营养因子(rhCNTF)在成肌细胞分化中的作用,实验观察了0-10 ng/mlrhCNTF对成人成肌细胞体外分化的影响。结果表明,与对照组相比,2.5-10 ng/ml rhCNTF能显著抑制成肌细胞的体外分化(P<0.01),并呈量-效依赖关系,且这种抑制作用是可逆的。Western Blot分析提示,这种抑制作用伴有成肌细胞分化期特异标志myogenin和p21表达量的显著降低(P<0.01),以及成肌细胞增殖期特异标志myf5和desmin表达量的显著增加(P<0.01)。因此可以认为,外源性rhCNTF能可逆地抑制成人成肌细胞的体外分化并保持增殖。     

The Cytokine Ciliary Neurotrophic Factor (CNTF) Activates Hypothalamic Urocortin-Expressing Neurons Both In Vitro and In Vivo

Ciliary neurotrophic factor (CNTF) induces neurogenesis, reduces feeding, and induces weight loss. However, the central mechanisms by which CNTF acts are vague. We employed the mHypoE-20/2 line that endogenously expresses the CNTF receptor to examine the direct effects of CNTF on mRNA levels of urocortin-1, urocortin-2, agouti-related peptide, brain-derived neurotrophic factor, and neurotensin. We found that treatment of 10 ng/ml CNTF significantly increased only urocortin-1 mRNA by 1.84-fold at 48 h. We then performed intracerebroventricular injections of 0.5 mg/mL CNTF into mice, and examined its effects on urocortin-1 neurons post-exposure. Through double-label immunohistochemistry using specific antibodies against c-Fos and urocortin-1, we showed that central CNTF administration significantly activated urocortin-1 neurons in specific areas of the hypothalamus. Taken together, our studies point to a potential role for CNTF in regulating hypothalamic urocortin-1-expressing neurons to mediate its recognized effects on energy homeostasis, neuronal proliferaton/survival, and/or neurogenesis.     

重组人睫状神经营养因子蛋白质定量检测方法的建立

采用ELISA双抗体夹心法,建立一种快速灵敏的定量检测rhCNTF成品蛋白含量的方法。结果显示,rhC-NTF抗原浓度在(0～25)ng范围内线性良好(r>0.99),灵敏度为0.3ng/ml,与其他重组细胞因子无交叉反应,样品的检测结果与理论含量相吻合,CV<15%,该方法检测速度快、重复性好、灵敏度高、特异性好。     

Neurotrophic agents prevent motoneuron death following sciatic nerve section in the neonatal mouse

We have examined the ability of different neurotrophic and growth factors to prevent axotomy-induced motoneuron cell death in the developing mouse spinal cord. After postnatal unilateral section of the mouse sciatic nerve, most motoneuron (MN) loss occurs in the lateral motor column of the fourth lumbar segment (L4). Significant axotomy-induced cell death occurred after surgery performed on or before postnatal day (PN) 5. In contrast, no significant cell loss was found when axotomy was performed after PN10. Axotomy on PN2 or PN5 resulted in a 44% loss of L4 motoneurons by 7 days, and a 66% loss of motoneurons by 10 days postsurgery. Implantation of gelfoam presoaked in various neurotrophic factors at the lesion site rescued axotomized motoneurons. Nerve growth factor (NGF), nedurotrophin-4/5 (NT-4/5) and ciliary neurotrophic factor (CNTF) rescued 20%–30% of motoneurons, whereas brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and insulin-like growth factor 1 (IGF-1) rescued virtually all motoneurons from axotomy-induced death. By contrast, platelet-derived growth factor (PDGF)-AA, PDGF-AB, basic fibroblast growth factor (bFGF), and interleukin (IL-6) were ineffective on motoneuron survival following axotomy. NGF, BDNF, NT-3, IGF-1, and CNTF also prevented axotomy-induced atrophy of surviving motoneurons. These data show that mouse lumbar motoneurons continue to be vulnerable to axotomy up to about 1 week after birth and that a number of trophic agents, including the neurotrophins, CNTF, and IGF-1, can prevent the death of these neurons following axotomy. Our studies confirm and extend previous reports on the time course of axotomy-induced mouse motoneuron death and the survival promoting effects of neurotrophic factors. 1994 John Wiley & Sons, Inc.     

Ciliary neurotrophic factor induces cholinergic differentiation of rat sympathetic neurons in culture

Ciliary neurotrophic factor (CNTF) influences the levels of choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH) in cultures of dissociated sympathetic neurons from newborn rats. In the presence of CNTF both the total and specific activity of ChAT was increased 7 d after culture by 15- and 18-fold, respectively, as compared to cultures kept in the absence of CNTF. Between 3 and 21 d in culture in the presence of CNTF the total ChAT activity increased by a factor of greater than 100. Immunotitration demonstrated that the elevated ChAT levels were due to an increased number of enzyme molecules. In contrast to the increase in ChAT levels, the total and specific activity levels of TH were decreased by 42 and 36%, respectively, after 7 d in culture. Half-maximal effects for both ChAT increase and TH decrease were obtained at CNTF concentrations of approximately 0.6 ng and maximal levels were reached at 1 ng of CNTF per milliliter of medium. The effect of CNTF on TH and ChAT levels were seen in serum-containing medium as well as in serum-free medium. CNTF was shown to have only a small effect on the long-term survival of rat sympathetic neurons. We therefore concluded that the effects of CNTF on ChAT and TH are not due to selective survival of cells that acquire cholinergic traits in vitro, but are rather due to the induction of cholinergic differentiation of noradrenergic sympathetic neurons.     

GM2 Ganglioside Regulates the Function of Ciliary Neurotrophic Factor Receptor in Murine Immortalized Motor Neuron-Like Cells (NSC-34)

We previously reported that ciliary neurotrophic factor (CNTF) increased the serum-free cell survival of immortalized motor neuron-like cells (NSC-34), and addition of the exogenous ganglioside GalNAc4(Neu5Ac3)Gal4GlcCer (GM2) facilitated cell survival together with CNTF. Moreover 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity increased in NSC-34 cells cultured with CNTF. We now have examined whether CNTF-induced cell survival is associated with the collaboration between GM2 and the CNTF receptor (CNTF-R). Despite the presence of CNTF (50 ng/ml), anti-CNTF-R antibody caused cell death and prevented the up-regulation of GM2 synthase expression. The addition of GM2 (1 to 20 M) abrogated the anti-CNTF-R antibody effect which shortened cell survival and blocked GM2 synthase activation. Use of [¹²⁵I]CNTF showed the specificity of CNTF binding in NSC-34 cells in situ. GM2 produced a 5-fold increase in the CNTF binding affinity per cell but did not change the binding site number. The study by metabolic labeling with [1–¹⁴C]N-acetyl-D-galactosamine ([¹⁴C]GalNAc) showed that biosynthesized GM2 was involved in the immunoprecipitation of CNTF-R. These findings indicate that up-regulated GM2 synthesis induces functional conversion of CNTF-R to the activated state, in which it has affinity for CNTF. We conclude that GM2 is a bio-regulating molecule of CNTF-R in motor neurons.     

Neuronal Survival,Morphology and Outgrowth of Spiral Ganglion Neurons Using a Defined Growth Factor Combination

Objectives

The functionality of cochlear implants (CI) depends, among others, on the number and excitability of surviving spiral ganglion neurons (SGN). The spatial separation between the SGN, located in the bony axis of the inner ear, and the CI, which is inserted in the scala tympani, results in suboptimal performance of CI patients and may be decreased by attracting the SGN neurites towards the electrode contacts. Neurotrophic factors (NTFs) can support neuronal survival and neurite outgrowth.

Methods

Since brain-derived neurotrophic factor (BDNF) is well known for its neuroprotective effect and ciliary neurotrophic factor (CNTF) increases neurite outgrowth, we evaluated if the combination of BDNF and CNTF leads to an enhanced neuronal survival with extended neurite outgrowth. Both NTFs were added in effective high concentrations (BDNF 50ng/ml, CNTF 100ng/ml), alone and in combination, to cultured dissociated SGN of neonatal rats for 48 hours.

Results

The neuronal survival and neurite outgrowth were significantly higher in SGN treated with the combination of the two NTFs compared to treatment with each factor alone. Additionally, with respect to the morphology, the combination of BDNF and CNTF leads to a significantly higher number of bipolar neurons and a decreased number of neurons without neurites in culture.

Conclusion

The combination of BDNF and CNTF shows a great potential to increase the neuronal survival and the number of bipolar neurons in vitro and to regenerate retracted nerve fibers.