胰岛素样生长因子对神经干细胞增殖分化的影响

神经干细胞 (ｎｅｕｒａｌｓｔｅｍｃｅｌｌｓ ,ＮＳＣｓ)能增殖成恰当数量的细胞 ,在脑部各个区域按正确顺序排列组合 ,分化为神经元 ,星形胶质细胞、少突胶质细胞 ,这是发育过程中必不可少的过程。众多研究提示细胞外因子参与此过程的调控并影响ＮＳＣｓ的分化启动和分化方向。在这些细胞外因子中有着显著影响作用的是众多的生长因子 ,如ＥＧＦ (表皮生长因子 )、ＦＧＦ (成纤维细胞生长因子 )、ＩＧＦ(胰岛素样生长因子Ｉｎｓｕｌｉｎ -ｌｉｋｅｇｒｏｗｔｈｆａｃｔｏｒ)等。深入了解生长因子对神经发生的作用有助于进一步认识细胞增殖…     

胰岛素样生长因子-1对骨骼肌源性干细胞的促增殖效应

目的 观察胰岛素样生长因子-1(IGF-1)对骨骼肌源性干细胞(MDSCs)生长的影响.方法 采用连续预贴壁法从新生小鼠后肢肌分离培养MDSCs;用含2%胎牛血清的DMEM培养基促进其向骨骼肌细胞分化.免疫细胞化学SP法检测于细胞标志Sca-1和骨骼肌细胞标志肌节(α-sarcomeric)肌动蛋白的表达情况;采用四甲基偶氮唑盐(MTT)比色法检测IGF-1对MDSCs增殖的影响,并分析IGF-1效应与培养时间以及与IGF-1浓度之间的关系.结果 从新生小鼠后肢肌成功分离培养MDSCs,90%以上的MDSCs呈Sca-1阳性;在分化培养中MDSCs能够产生α-sarcomeric 肌动蛋白阳性的肌管;IGF-1对MDSCs促增殖作用随细胞培养时间的延长逐渐明显;随IGF-1浓度的增加而增加,并逐渐趋于饱和.结论 IGF-1对体外培养的MDSCs有促进增殖的作用.     

胰岛素样生长因子与糖尿病神经病变

胰岛素样生长因子（ＩＧＦｓ）是一种具有胰岛素样作用的生长因子,它具有促进神经生长和修复作用。在有糖尿病神经病变的患者或鼠,ＩＧＦ的水平及作用减低。糖尿病早期,神经组织中的ＩＧＦ的基因表达减少。补充ＩＧＦ能改善甚至逆转糖尿病神经病变、提高神经传导速度。但ＩＧＦ的治疗具有一定的副作用,剂量较大时较为明显。     

Netrins与神经轴突的生长发育

神经细胞在胚胎发育过程中形成相互联系 ,须依靠神经轴突正确投射到靶细胞的能力。Netrins是一族高度保守的神经导向分子家族成员 ,在轴突的延长和诱向中发挥了重要作用。轴突对导向分子的反应各不相同 ,即使是同一个生长锥也会在投射路程中改变对相同导向分子的反应。内在和外在的影响因素同时参与了处于发育中的轴突生长锥对Netrins的反应性的变化。本文综述了Netrins的功能及其所涉及的精细的调节机制     

胰岛素样生长因子与胎儿生长发育的关系

为了探讨胎儿在宫内生长发育与胰岛素生长因子 -Ⅰ(IGF -Ⅰ )的关系及明确IGF -Ⅰ在胎儿生长发育中所起的作用 ,我们对不同体重的胎儿脐带血清做了IGF -Ⅰ浓度检测 ,以探讨其对胎儿体重的影响。材料和方法一、对象 :我院第一胎足月分娩健康产妇 71例所生产的健康新生儿 ,其母亲年龄 2 0～ 34岁 ,平均 2 6 2 5岁。将新生儿按出生时体重分为大、中、小三组 :其中体重≥ 4 0 0 0g为大体重组 ,有新生儿 11例 ;体重在 30 0 0～ 3999g为中体重组 ,有新生儿 37例 ;体重≤ 30 0 0g为小体重组 ,有新生儿 2 3例。二、方法 :离胎儿身体 2cm剪断脐…     

胰岛素样生长因子及胰岛素样生长因子结合结白-3与胎儿生长发育的关系

目的探讨胰岛素样生长因子-Ⅰ、胰岛素样生长因子-Ⅱ、胰岛素样生长因子结合蛋白-3与胎儿生长发育的关系,为FGR的临床诊断和治疗提供理论依据和新思路。方法分别采集确诊FGR组、正常对照组和巨大儿组胎儿脐血标本,采用放射免疫测定其中胰岛素样生长因子-Ⅰ、胰岛素样生长因子-Ⅱ、胰岛素样生长因子结合蛋白-3的含量。结果 1.FGR组脐血清IGF-Ⅰ、IGF-Ⅱ、IGFBP-3水平下降,巨大儿组脐血清IGF-Ⅰ水平升高;2.新生儿脐血清IGF-Ⅰ、IGF-Ⅱ水平与新生儿出生体重、身长、胎盘重量呈明显正相关关系,脐血清IGF-Ⅰ水平与胎龄呈明显正相关关系,脐血清IGFBP-3水平与胎龄、新生儿出生体重、身长、胎盘重量呈明显正相关关系;3.脐血清IGF-Ⅰ与IG-FBP-3水平与产妇产前体重呈明显正相关关系,IGF-Ⅱ水平与产妇产前体重呈正相关关系。结沦脐血清IGF-Ⅰ、IGF-Ⅱ、IGFBP-3水平可作为预测胎儿和胎盘生长发育情况的参考指标,IGF-Ⅰ水平是其中最灵敏的指标;脐血清IGF-Ⅰ、IGF-Ⅱ、IGFBP-3水平的降低可能是导致FGR的重要原因之一;监测产妇产前体重可以间接反映胎儿血IGFs及IG-FBP-3水平,进而反映胎儿的生长发育状况。     

人胰岛素样生长因子1基因转染脂肪源性干细胞的效应

背景：人胰岛素样生长因子1基因对脂肪源性干细胞的增殖和分化也可能会产生有效作用。 目的：验证人胰岛素样生长因子1基因转染对体外培养的脂肪源性干细胞的效应。 方法：构建含人胰岛素样生长因子1基因的双顺反子真核表达载体pIRES2-EGFP-hIGF-1,利用阳离子脂质体Lipofectamine 2000介导转染体外培养的人脂肪源性干细胞。观察基因转染后细胞增殖及形态的变化,倒置荧光显微镜观测标记基因增强绿色荧光蛋白的表达并计算转染效率,酶联免疫吸附试验检测培养上清中人胰岛素样生长因子1的浓度,免疫组织化学染色及RT-PCR检测人胰岛素样生长因子1的表达,流式细胞仪检测转染前后细胞周期的变化。 结果与结论：测序及酶切证实真核表达载体pIRES2-EGFP-hIGF-1构建正确。体外培养的脂肪源性干细胞为多种形态并存,转染后6 h检测到有EGFP的表达,至60 h达到高峰,转染效率为(16±3)%。细胞上清中人胰岛素样生长因子1的浓度在60 h达到22.65 μg/L。免疫组织化学染色及RT-PCR均检测到人胰岛素样生长因子1的表达。转染后的细胞分裂增殖加快,细胞群体倍增时间缩短,S期细胞比例增多。证实人胰岛素样生长因子1基因可有效转染脂肪源性干细胞并表达人胰岛素样生长因子1蛋白质,同时可促进细胞增殖。     

胰岛素样生长因子-1拮抗c17.2神经干细胞的放射损伤

目的：评价IGF-1（胰岛素样生长因子-1）对放射引起的c17.2神经干细胞凋亡或坏死所产生的拮抗作用。方法:c17.2神经干细胞培养，免疫组化检测神经干细胞特异性抗原nestin（巢蛋白）及X-gal（吡喃半乳糖苷衍生物）染色检测 lac-z基因的表达。将IGF-1重组腺病毒转染c17.2神经干细胞，免疫组化法鉴定IGF-1蛋白的表达。建立放射引起体外培养的c17.2神经干细胞损伤的模型,流式细胞术及TUNEL法（原位末端标记）评判细胞的凋亡或坏死。观察胰岛素样生长因子-1重组腺病毒转染对细胞凋亡或坏死程度的影响。结果:绝大部分细胞nestin抗原染色阳性，X-gal染色阳性。免疫组化检测结果表明转染病毒的c17.2神经干细胞有IGF-1蛋白的表达，相同照射剂量下转染重组腺病毒的细胞凋亡率及坏死率较未转染细胞低 。结论：重组腺病毒介导的IGF-1转染可减少放射引起的c17.2神经干细胞的坏死和凋亡。IGF-1基因对神经干细胞有保护作用。     

胰岛素-胰岛素样生长因子-Ⅰ与胎儿宫内生长发育的关系

目的探讨母血、脐血中胰岛素-胰岛素样生长因子的水平-Ⅰ与胎儿宫内生长发育的关系及意义。方法收集2010年9月～2011年3月在本院分娩的单胎足月正常妊娠(无产科并发症)孕妇及其新生儿各90例,分娩前抽取孕妇空腹静脉血5 ml,胎儿娩出后即抽脐静脉血5 ml,标本收集后用高效液相色谱法测定母血、脐血中胰岛素及胰岛素样生长因子-Ⅰ的水平。结果 SGA脐带血清胰岛素、胰岛素样生长因子-Ⅰ水平明显低于AGA、LGA;AGA脐血胰岛素、胰岛素样生长因子-Ⅰ水平低于LGA组,差异均有统计学意义;母血胰岛素样生长因子-Ⅰ水平在SGA、AGA、LGA三组中差异有显著性(P<0.01),而胰岛素水平在SGA、AGA、LGA三组中差异无显著性;脐血中胰岛素与胰岛素样生长因子-Ⅰ水平呈正相关关系;脐血胰岛素、胰岛素样生长因子-Ⅰ水平与新生儿出生体重、身长、胎盘重量、体重指数呈明显正相关关系。结论脐血胰岛素、胰岛素样生长因子-Ⅰ水平与胎儿生长发育相关,低脐血胰岛素、胰岛素样生长因子-Ⅰ水平与胎儿宫内生长受限关系更为密切,母血胰岛素样生长因子-Ⅰ水平可作为评估胎儿宫内生长发育的指标。     

胰岛素样生长因子轴与肝癌

胰岛素样生长因子轴的失调在肝癌的发生发展过程中发挥重要作用 ,它包括胰岛素样生长因子 (In sulin likegrowthfactors ,IGFs)、IGF受体、胰岛素样生长因子结合蛋白 (IGFbindingproteins,IGFBPs)和IGFBP蛋白水解酶。肝癌组织中IGF Ⅱ表达增加 ,IGF Ⅰ表达下降。IGFBP降解增加 ,进一步促进了IGFs的生物利用度。同时 ,IGFBP 3可不依赖IGFs而抑制肝癌的发生。     

Insulin-like growth factor I modifies electrophysiological properties of rat brain stem neurons

On systemic injection, insulin-like growth factor I (IGF-I) elicits a prolonged increase in the excitability of dorsal column nuclei (DCN) cells in the brain stem as well as other target neurons within the brain. We have explored the cellular mechanisms involved in the stimulatory effects of IGF-I as well as its functional consequences. In a rat slice preparation, IGF-I induced a sustained depolarization of 2-5 mV in 81% of DCN neurons. Depolarization was accompanied with an increase in the input resistance (15%). Voltage-clamp recordings displayed that IGF-I decreased a K+-mediated A current (60%). Furthermore, IGF-I increased, in 78% of cells, the peak amplitude (25%), and rising slope (32%) of the excitatory postsynaptic potential evoked by dorsal column stimulation; in this case, a presynaptic facilitatory process appears to be involved. When anesthetized adult rats are injected in the carotid artery with IGF-I, extracellularly recorded propioceptive DCN neurons not only show increased spike activity but also an expansion of their cutaneous receptive field in 83% of DCN cells. Significantly, the increased excitability evoked by IGF-I in the DCN cells depends both in vivo and in vitro, on activation of p38 mitogen-activated protein kinase (MAPK), a Ser-kinase known to modulate K+ channel activity. We concluded that systemic IGF-I modulated the electrophysiological properties of target neurons within the brain. In turn, these changes probably contribute to functional reorganization processes such as expansion of neuronal receptive fields.     

Insulin-like growth factor 2 promotes osteogenic cell differentiation in the parthenogenetic murine embryonic stem cells

Embryonic stem cells (ESCs) are pluripotent and can differentiate into all somatic cell types. ESCs are an alternative solution to hard tissue regeneration and skeletal tissue repair to treat bone diseases and defects using regenerative strategies. Parthenogenetic ESCs (PESCs) may be a useful alternative stem cell source for tissue repair and regeneration. The defects in full-term development of this cell type enable researchers to avoid the ethical concerns related to ESC research. Moreover, in female patients, if the PESCs are derived from oocytes, then they will have that patient's genetic information. Here, we present data demonstrating that osteogenic differentiation of PESCs can be promoted by insulin-like growth factor 2 (IGF2). PESCs were plated onto Petri dishes with ESC culture medium supplemented with or without IGF2, followed by culturing of the cells for 1 week. PESCs formed floating aggregates called embryoid bodies (EBs). An osteogenic lineage was induced from the EBs by incubating them in medium containing serum, ascorbic acid, β-glycerophosphate, and retionic acid, with or without IGF2, for 20 days. Gene expression of specific osteoblastic markers such as osteocalcin, osteopontin, osteonectin, bone sialoprotein, collagen type-I, alkaline phosphatase, and Runx2 (Cbfa-I) was analyzed by real-time polymerase chain reaction. The expression level of osteocalcin, osteopontin, osteonectin, and alkaline phosphatase was twofold higher in IGF2-treated PESC derivatives than IGF2-naive PESC derivatives. In vivo experiments were also performed using a critical-sized calvarial defect mouse model. Ten weeks after cell transplantation, more bone tissue regeneration was observed in the IGF2-treated PESC transplantation group than in IGF2-naive PESC transplantation group. Both our in vitro and in vivo data indicate that IGF2 induces osteogenic differentiation of PESCs. Addition of IGF2 may reactivate imprinting genes in PESCs that are only expressed in the paternal genome and are normally silent in PESCs. Our findings provide insights into the mechanisms of skeletal tissue repair and the imprinting mechanisms active in stem cells.     

胰岛素样生长因子1促进创伤性关节炎软骨细胞的体外增殖

背景：早期受损的软骨细胞在体外培养时容易产生去分化,表型不稳,常需添加一定的生长因子。 目的：观察胰岛素样生长因子1对成年兔创伤性关节炎早期关节软骨细胞体外增殖的促进作用。 方法：采用改良Hulth法制备成兔创伤性关节炎模型,造模成功后无菌条件下片状切取股骨远端及胫骨近端,用消化培养法培养软骨细胞。将软骨细胞随机分为2组,对照组加入含体积分数10%胎牛血清因子的DMEM培养液培养;实验组在对照组的基础上加入100 μg/L的胰岛素样生长因子1。通过细胞形态学、细胞计数、细胞活性检测胰岛素样生长因子1对创伤性关节炎关节软骨细胞增殖的影响。 结果与结论：成功培养出早期创伤性关节炎兔软骨细胞,细胞多数为小细胞,形态有小梭形、小圆形及小多边形。苏木精-伊红染色显示实验组细胞数量多于对照组,MTT实验证实实验组细胞的吸光度值大于对照组   (P < 0.01)。结果提示,胰岛素样生长因子1能促进早期创伤性关节炎模型兔软骨细胞的体外增殖。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

肝细胞生长因子促大鼠神经干细胞增殖的作用

目的:研究肝细胞生长因子(HGF)对大鼠神经干细胞(NSCs)增殖的作用以及PI3K/Akt信号途径的影响.方法:分离培养大鼠NSCs,通过向神经培养基中添加HGF(10,30,60 ng/ml),计数干细胞克隆形成率、四甲基偶氮唑蓝(MTT)比色法以及5-溴-2'-脱氧尿苷(BrdU)标记检测NSCs的增殖,Annexin V/FITC免疫荧光显色测定NSCs的凋亡;免疫印迹法检测细胞磷酸化Akt蛋白表达的变化.结果:与对照组相比,HGF各剂量组NSCs克隆率明显增加,生长速度增快,BrdU 阳性细胞增加,NSCs凋亡率显著减少.此外,HGF可上调磷酸化Akt蛋白的表达,HGF的效应可被PI3K/Akt通路抑制剂LY294002阻断.结论:HGF可促进大鼠NSCs增殖,抑制其凋亡,其作用机制可能与激活NSCs的PI3K/Akt信号转导通路有关.     

Increasing doublecortin expression promotes migration of human embryonic stem cell-derived neurons

Human embryonic stem cell-derived neuronal progenitors (hNPs) provide a potential source for cellular replacement following neurodegenerative diseases. One of the greatest challenges for future neuron replacement therapies will be to control extensive cell proliferation and stimulate cell migration of transplanted cells. The doublecortin (DCX) gene encodes the protein DCX, a microtubule-associated protein essential for the migration of neurons in the human brain. In this study, we tested whether increasing the expression of DCX in hNPs would favorably alter their proliferation and migration. Migration and proliferation of hNPs was compared between hNPs expressing a bicistronic DCX/IRES-GFP transgene and those expressing a green fluorescent protein (GFP) transgene introduced by piggyBac-mediated transposition. The DCX-transfected hNPs showed a significant decrease in their proliferation and migrated significantly further on two different substrates, Matrigel and brain slices. Additionally, a dense network of nestin-positive (+) and vimentin+ fibers were found to extend from neurospheres transplanted onto brain slices, and this fiber growth was increased from neurospheres containing DCX-transfected hNPs. In summary, our results show that increased DCX expression inhibits proliferation and promotes migration of hNPs. Stem Cells2012;30:1852-1862.     

神经再生素促进神经干细胞的生长和分化

目的:研究神经再生素对体外培养神经干细胞分化的促进作用及对其生长相关蛋白(GAP43)、神经丝蛋白(NF-H)表达的影响.方法:取出生3～5d的新生SD大鼠大脑皮层进行神经干细胞的体外培养、鉴定,神经干细胞与0、 1、 2mg/L的神经再生素(NRF)共培养8d,相差显微镜观察分析,应用Real-time PCR对与不同浓度的NRF(0、 1、 2、 4、 8mg/L)共培养8d的神经干细胞进行GAP43、 NF-H的表达量检测.结果:成功培养出具有多向分化潜能的神经干细胞;神经再生素可明显促进神经干细胞的分化,并能在一定范围内随浓度递增而有效促进GAP43、 NF-H的表达,且最佳作用浓度为4mg/L.结论:神经再生素可以促进神经干细胞的生长和分化.     

Human neural stem cell-derived cholinergic neurons innervate muscle in motoneuron deficient adult rats

Motoneuron damage occurs in spinal cord injury and amyotrophic lateral sclerosis. Current advances offer hope that human embryonic stem cells [Science 282 (1998) 1145] or neural stem cells (NSC) [Exp Neurol 161 (2000) 67; Exp Neurol 158 (1999) 265; J Neurosci Methods 85 (1998) 141; Proc Natl Acad Sci USA 97 (2000) 14720; Exp Neurol 156 (1999) 156 ] may be donors to replace lost motoneurons. Previously, we developed a priming procedure that produced cholinergic cells that resemble motoneurons from human NSCs grafted into adult rat spinal cord [Nat Neurosci 5 (2002a) 1271]. However, effective replacement therapy will ultimately rely on successful connection of new motoneurons with their muscle targets. In this study, we examined the potential of human fetal NSC transplantation to replace lost motoneurons in an animal model of chronic motoneuron deficiency (newborn sciatic axotomy) [J Comp Neurol 224 (1984) 252; J Neurobiol 23 (1992) 1231]. We found, for the first time, that human neural stem cell-derived motoneurons send axons that pass through ventral root and sciatic nerve to form neuromuscular junctions with their peripheral muscle targets. Furthermore, this new cholinergic innervation correlates with partial improvement of motor function.     

Insulin-like growth factor I partly prevents axon elimination in the neonate rat optic nerve

Low-power, near-infra-red laser irradiation has been used to relieve patients from various kinds of pain, though the precise mechanisms of such biological actions of the laser have not yet been resolved. To investigate the cellular mechanisms by near-infra-red laser on the nervous system, we examined the effect of 830-nm laser irradiation on the energy metabolism of the rat brain. The diode laser was applied for 15 min with an irradiance of 4.8 W/cm(2). Tissue adenosine triphosphate (ATP) content of the irradiated area in the cerebral cortex was 19% higher than that of the non-treated area, whereas the adenosine diphosphate (ADP) content showed no significant difference. Laser irradiation at another wavelength (652 nm) had no effect on either ATP or ADP contents. The temperature of the tissue was increased by 4.4-4.7 degrees C during the irradiation of both wavelengths. These results suggest that the increase in tissue ATP content did not result from the thermal effect, but from a specific effect of the laser operated at the 830-nm wavelength.     

神经干细胞外泌体对低氧所致神经元凋亡的抑制作用

目的:初步探讨神经干细胞分泌的外泌体是否能抑制氯化钴(cobalt chloride,CoCl_2)诱导的缺氧模型中神经元的凋亡,并促进神经元的存活。方法:超速离心法分离大鼠神经干细胞分泌的外泌体;Western blot检测外泌体表面标志物ALG-2相互作用蛋白X(ALG-2-interacting protein X,Alix)和肿瘤易感基因101(tumor susceptibility gene 101,TSG101)的表达水平;用透射电子显微镜观察外泌体的形态;q Nano纳米生物颗粒分析仪检测外泌体的粒径分布。采用不同剂量的Co Cl_2处理神经元,建立CoCl_2诱导神经元凋亡的模型;将神经干细胞分泌的外泌体加入凋亡组神经元,CCK-8法检测细胞活力,TUNEL法检测细胞凋亡。结果:神经干细胞分泌的外泌体可表达Alix和TSG101;外泌体在透射电镜下的形态呈"杯口"状,大小约为100 nm;q Nano纳米生物颗粒分析仪检测外泌体的粒径为(95.0±23.5)nm(n=370);CCK-8实验结果显示不同浓度(200、400和600μmol/L)CoCl_2作用24 h,神经元活力呈剂量依赖性下降(P0.05);将神经干细胞分泌的外泌体加入凋亡组(CoCl_2浓度为400μmol/L)神经元后,神经元活力升高(P0.05),凋亡率下降(P0.05)。结论:神经干细胞分泌的外泌体能抑制低氧状态下神经元的凋亡并促进存活。     

Axonal growth regulation of fetal and embryonic stem cell-derived dopaminergic neurons by Netrin-1 and Slits

The physical restoration of dopamine circuits damaged or lost in Parkinson disease by implanting embryonic stem (ES)-derived cells may become a treatment. It is critical to understand responses of ES-derived dopamine (DA) neurons to guidance signals that determine axonal path and targeting. Using a collagen gel culture system, we examined effects of secreted molecules Netrin-1 and Slits on neurite outgrowth of fetal DA neurons and murine ES-differentiated DA neurons. We have previously shown that fetal DA neurons express DCC and Robo1/2 receptors and that Netrin-1 and Slit2 function as an attractant and a repellent for DA neurite outgrowth. In the present study, we observe that both Slit1 and Slit3 repel and inhibit neurite growth of fetal DA neurons. Here, we also demonstrate that ES-differentiated neurons including DA neurons express the Netrin receptor DCC and Slit receptor Robo proteins. In the gel culture system of ES cells, Netrin-1 promoted neurite outgrowth mediated by DCC receptor, and Slit1 and Slit3 were inhibitory for neurite outgrowth through Robo receptors. Slit2 appeared to exert inhibitory as well as repulsive effects in the coculture assay. However, unlike fetal DA neurites, no directed neurite outgrowth was observed in the cocultures of ES-derived DA neurons with Netrin-1-, Slit1-, and Slit3-producing cells. The findings suggest that ES-derived DA neurons generated by current protocols can respond to guidance cues in vitro in a similar manner to fetal cells but also exhibit distinct responses. This may result from developmental differences generated by present in vitro methods of cell patterning or conditioning during ES cell differentiation.