气道上皮细胞的抗氧化损伤保护及微环境调控

本工作建立了臭氧对原代培养的兔支气管上皮细胞（ＢＥＣ）损伤模型,观察到血管活性肠肽（ＶＩＰ）、表皮生长因子（ＥＧＦ）、热应激等微环境理化因子可减轻细胞损伤,具有细胞保护作用,其保护机制与提高还原谷胱甘肽（ＧＳＨ）含量有关,并依赖于蛋白激酶的磷酸化调节及基因转录。ＢＥＣ细胞在基础情况下有ｂｃｌ－２基因的低水平表达。ＶＩＰ和ＥＧＦ可促进ｂｃｌ－２基因转录,增强ＢＥＣ的抗氧化损伤能力。ＥＧＦ或热应激促进     

重组人碱性成纤维细胞生长因子(bFGF)融合蛋白的高效表达及鉴定

碱性成纤维细胞生长因子（ｂＦＧＦ）参与了许多细胞生长和分化的调控过程。本文采用重组ＤＮＡ技术在大肠杆菌中高效表达了人ｂＦＧＦ。首先将编码人ｂＦＧＦ基因克隆到ｐＸＴ表达载体中与其上游的一短Ｓ导肽共一阅读框架,ｂＦＧＦ基因的表达受强的Ｔ７启动子调控。采用ＢＬ２１（ＤＥ３）大肠杆菌作为宿主菌,用ＩＰＴＧ诱导ＢＬ２１（ＤＥ３）细菌合成的Ｔ７ＲＮＡ聚合酶,后者可催化高水平的ｂＦＧＦ基因表达,其ｂＦＧＦ产量可占总菌体蛋白的４２.５％。采用肝素Ｓｅｐｈａｒｏｓｅ一步亲和层析法直接从诱导后的细菌裂解产物中得到纯化的重组人ｂＦＧＦ蛋白。经Ｗｅｓｔｅｒｎ印迹分析证明该蛋白可被人ｂＦＧＦ特异性单克隆抗体所识别。进一步研究证明该蛋白具有刺激ＮＲ６Ｒ－３Ｔ３成纤维细胞增殖的生物学活性,并且这一活性可被人ｂＦＧＦ特异性中和抗体所中和。     

抗真菌蛋白Rs—AFPs基因在大肠杆菌中的表达

将抗真菌蛋白Ｒｓ－ＡＦＰ１和Ｒｓ－ＡＦＰ２全长ｃＤＮＡ插入表达质粒ｐＥＴ－２２ｂ／ＮｃｏＩ＋ＳａｃＩ位点,构建成融合蛋白表达载体ｐＲＡＦ１和ｐＲＡＦ２．将不含信号肽编码序列的Ｒｓ－ＡＦＰ１和Ｒｓ－ＡＦＰ２ｃＤＮＡ分别插入ｐＥＴ－２２ｂ／Ｎｃｏｌ＋Ｓａｃｌ和ｐＥＴ－２２ｂ／Ｎｄｅｌ＋ＳａｃＩ位点,构建成不含信号肽序列的融合蛋白表达载体ｐＲＡＦ３、ｐＲＡＦ４和非融合蛋白表达载体ｐＲＡＦ５和ｐＲＡＦ６．将构建的上述各种表达载体转化Ｅ．ｃｏｌｉＢＬ２１,挑菌落培养,ＩＰＴＧ诱导,使Ｒｓ－ＡＦＰｓ基因得到表达,并用体外抑菌试验检测表达产物的活性,结果表明,各种表达载体的表达产物均具有不同程度的抑菌活性,其中,ｐＲＡＦ３和ｐＲＡＦ４表达产物的抑菌活性较明显．     

碱性成纤维细胞生长因子对大鼠肾小球系膜细胞原癌基因c-fos和c-myc表达的影响

在建立大鼠肾小球系膜细胞（ＭＣ）体外培养方法的基础上,通过３Ｈ－ＴｄＲ参入实验,ＲＮＡ印迹分析和斑点杂交观察ｂＦＧＦ对ＭＣＤＮＡ合成及原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达的影响．结果表明,ｂＦＧＦ作用于ＭＣ１８ｈ,ＭＣ的３Ｈ－ＴｄＲ参入率明显增加（Ｐ＜０．０５）,２４ｈ达到高峰（Ｐ＜０．０１）;ｂＦＧＦ显著诱导原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达,其表达活性分别于３０ｍｉｎ和１ｈ达到高峰．提示ｂＦＧＦ是ＭＣ的强效丝裂原,其对ＭＣＤＮＡ合成的促进作用与诱导原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达有关．     

体外培养条件下SCF、LIF与bFGF对昆明白小鼠精原干细胞增殖的影响

生长因子作为细胞体外培养和在体细胞生长及增殖必需的调节因子 ,一直被广泛的关注。业已证明干细胞因子(ＳｔｅｍＣｅｌｌＦａｃｔｏｒ,ＳＣＦ)、白血病抑制因子 (ｌｅｕｋａｅｍｉａｉｎｈｉｂｉｔｏｒｙｆａｃｔｏｒ,ＬＩＦ)和碱性成纤维细胞生长因子 (ＢｓａｉｃＦｉｂｒｏｂｌａｓｔＧｒｏｗｔｈＦａｃｔｏｒ,ｂＦＧＦ)具有刺激细胞增殖的作用[1～ 4] ,但大都是对单一因子进行研究。本实验探讨用这三种生长因子的不同组合观察对小鼠精原干细胞增殖的作用 ,以期定性和定量的探讨出体外培养初期三种因子对小鼠精原干细胞生长的影响 ,为小…     

EGFR反义脱氧寡核苷酸及其硫代修饰片段抑制人肝癌细胞系BEL…

本文旨在研究针对ＥＧＦＲ ｍＲＮＡ的反义寡核苷酸片段对ＢＥＬ－７４０４细胞ＥＧＦＲ基因表达及其对细胞生长的影响。合成了互补于ＥＧＦＲ基因５’起始编码区的２１聚脱氧寡核苷酸（ＯＤＮｓ）。实验结果显示,３．２ｕｍｏｌ／Ｌ ＯＤＮｓ明显抑制ＢＥＬ－７４０４细胞生长,「３Ｈ」Ｔｄｒ掺入抑制试验显示其对细胞ＤＮＡ合成的抑制作用表现剂量依赖性;密度扫描分析显示ＯＤＮｓ处理６、２４ｈ后,肝癌细胞ＥＧＦＲ ｍＲＮ     

福尔马林固定云南鲴的DNA提取及其细胞色素b基因序列分析

福尔马林固定云南鲴的ＤＮＡ提取及其细胞色素ｂ基因序列分析ＤＮＡＥＸＴＲＡＣＴＥＤＦＲＯＭＦＯＲＭＡＬＩＮ－ＦＩＸＥＤＸｅｎｏｃｙｐｒｉｓｙｕｎｎａｎｅｎｓｉｓＡＮＤＳＥＱＵＥＮＣＥＡＮＡＬＹＳＩＳＯＦＩＴＳＣＹＴＯＣＨＲＯＭＥＢＧＥＮＥ关键词福尔马林...     

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。     

表皮生长因子与前列腺增生及前列腺癌的关系

195 9年Ｃｏｈｅｎ[1] 在纯化神经生长因子 (ＮＧＦ)的过程中 ,首先从小鼠颌下腺中发现了一种对外胚层、中胚层和内胚层细胞具有促分裂活性的多肽生长因子 ,并能明显地促进表皮细胞的生长与角化 ,命名为表皮生长因子 (ＥｐｉｄｅｒｍａｌＧｒｏｕｔｈＦａｃｔｏｒＥＧＦ)。人的表皮生长因子以ｈＥＧＦ - β和ｈＥＧＦ -γ两种形式存在。由于它对胃酸具有很强的抑制作用 ,故又命名为尿抑胃素 (ｕｒｏｇａｓｔｒｏｎｅ)。 1975年Ｓｔａｒｋｅｙ等人[2 ] 从尿中纯化获得了ＥＧＦ的纯品 ,并确定其结构。ｈＥＧＦ - β和ｈＥＧＦ -γ具有高度的同…     

G蛋白Rap1活化新机制：GEFs研究进展

小分子Ｇ蛋白Ｒａｓ超家庭成员都是通过与鸟苷酸交换因子（ｇｕａｎｉｎｅ ｎｕｃｌｅｏｔｉｄｅ ｅｘｃｈａｎｇｅ ｆａｃｔｏｒｓ,ＧＥＦｓ）结合而被活化,ＧＥＦｓ能增加这类小分子Ｇ蛋白对ＧＴＰ的摄取,并使之形成有活性的ＧＴＰ结合构象。Ｒａｐ１是Ｒａｓ样的小分子Ｇ蛋白。迄今为止,已发现Ｇ３Ｇ、ＣａｌＤＡＧ－ＧＥＦ１、Ｅｐａｃ、ｃＡＭ－ＧＥＦ１、ｃＡＭＰ－ＧＥＦⅡ、ｎＲａｐＧＥＰ、ＧＦＲ可特异的活化Ｒａｐ     

Effect of basic FGF on the proliferation of rat neuroblasts in culture

Cultures highly enriched in neuronal cells, derived from brain hemispheres of 13-day-old rat embryo, were used. In these cultures, neuroblasts proliferate during the first 3 days in vitro. The addition of the astroglial growth factor (AGF2), also known as basic fibroblast growth factor (bFGF), 4 hrs. after seeding, induces a strong increase of [125I]-deoxyuridine incorporation. We checked by autoradiography combined with specific immunocytochemical staining of the neurones, using an anti-neurofilament antibody, that the number of proliferating neuroblasts is increased after the treatment. These results demonstrate that AGF2, or bFGF, is a mitogenic factor for rat neuroblasts in culture.     

多因素对昆明小鼠胚胎干细胞原代集落形成和后期增殖的影响

目的：研究细胞因子LIF、EGF、bFGF和肝素钠,以及氧分压、温度等多因素对昆明系小鼠胚胎干细胞（KM-ESC）原代集落形成和后期增殖的影响。方法：本研究选择LIF、EGF、bFGF、肝素钠、5%O2,20%O2和37℃、39℃作为研究条件。并检测不同情况下小鼠胚胎干细胞原代集落形成和后期增殖情况。结果：LIF对KM-ESC原代集落形成和后期增殖具有显著促进作用,极显著高于EGF、bFGF和肝素钠组（P〈0.01）。温度对KM-ESC原代集落形成和增殖具有显著影响,39℃条件下,原代集落形成率、直径和后期增殖显著高于37℃（P〈0.05）;而氧分压对KM-ESC原代集落形成无显著作用（P〉0.05）,但是对原代集落直径和后期增殖有一定促进作用,20%O2组显著高于5%O2组（P〈0.05）。结论：LIF、EGF、bFGF、肝素钠、39℃、20%O2对小鼠胚胎干细胞原代集落形成和后期增殖具有显著促进作用。     

The sensitivity of mesenchymal stromal cells subpopulations with different adhesion properties and derived from hemopoietic organs to growth factors EGF,bFGF, and PDGF

The action of three growth factors (EGF, bFGF, and PDGF) on mesenchymal stromal cell (MSC) subpopulations from rat adult bone marrow (BM) and embryo liver (EL) was investigated. These cells are plastic-adhesive and have different rates of adhesion (AS1–AS4 subpopulations). The efficiency of colony-formation, the size of colonies, and the number of early osteogenic progenitors with alkaline phosphatase activity in colonies and induced osteogenesis were analyzed. It was shown that EGF increased the number of bone marrow (BM) MSC colonies, but it had no influence on osteogenic differentiation. bFGF suppressed colony formation, but it stimulated both early and late stages of osteogenesis. PDGF increased the size and the number of colonies in AS2 and AS3 subpopulations, but it stimulated only the terminal stage of ostegenesis. The distinction between MSC subpopulations from two organs was found: MSC from EL had small osteogenic capacities and low sensitivity to grow factors; MSC from BM had no such characteristics. MSC subpopulations with different adhesion properties and from different tissues had compatible sensitivity to growth factors.     

Basic fibroblast growth factor enhances the capacity of bone marrow cells to form bone-like nodules in vitro

The role of basic fibroblast growth factor (bFGF) in the proliferation and differentiation of rat bone marrow cells in culture was studied. bFGF stimulated [3H]thymidine incorporation into these cells by 4-fold at a concentration of 0.3 ng/ml and half-maximal effect was observed at a concentration of 15 pg/ml. In addition to its mitogenic effect, bFGF stimulated alkaline phosphatase activity by 3.6-fold. Continuous treatment with bFGF (for 21 days) resulted in a 6.3-fold increase in the culture dish surface area covered by bone-like mineralized tissue. Maximal bone-like tissue formation was observed in the presence of 3 ng/ml bFGF with half-maximal effect at a concentration of 0.3 ng/ml. These results indicate the possible role of bFGF in the proliferation of osteogenic rat bone marrow cells and their differentiation into cells of osteoblast-like phenotype.     

GABAergic Growth Cones: Release of Endogenous γ-Aminobutyric Acid Precedes the Expression of Synaptic Vesicle Antigens

Growth cone fractions isolated from neonatal [postnatal day 3 (P3)] rat forebrain contain GABAergic growth cones as demonstrated by immunofluorescence staining with monospecific antibodies to gamma-aminobutyric acid (GABA). HPLC analysis shows that GABAergic growth cones release this endogenous GABA when stimulated with high K+. Endogenous GABA release is Ca2(+)-independent and, in this respect, similar to that seen previously with [3H]GABA. Isolated growth cone fractions also exhibit a K(+)-stimulated, Ca2(+)-independent release of endogenous taurine. None of the other amino acids shown to be present in isolated growth cone fractions were released, including glutamate, aspartate, and glycine. A population of dissociated cerebral cortical neurones prepared from P1 rat forebrain were GABA-immunoreactive after 1 day in culture. The cell body, neurites, and growth cones of these neurones were all stained with GABA antibodies. At this time in culture, neurones did not stain with either of two antibodies to synaptic vesicle antigens, i.e., p65 and synaptophysin. Growth cones isolated from P3 rat forebrain were also not immunoreactive with these antibodies. After about 8 days in culture, when neurones had established extensive networks of long, varicose axons and elaborately branched dendrites, many neurones and their neurites were immunoreactive for GABA antibodies. At this time in culture, p65 and synaptophysin antibodies did stain neuronal cell bodies and particularly their varicose axons. Dendrites were not stained with synaptic vesicle antibodies. These results suggest that GABAergic neurones synthesize GABA during neurite outgrowth and that GABA is present in, and can be released from, the growth cones of these neurones. The presence of GABA in GABAergic growth cones is not associated with synaptic vesicles, which explains the Ca2+ independency of both endogenous and [3H]GABA release from these growth cones.     

Basic fibroblast growth factor inhibits osteoclast-like cell formation

Basic fibroblast growth factor (bFGF) inhibited osteoclast-like cell formation in co-cultures of mouse bone marrow cells either with the mouse stromal cell line, ST2, or with primary osteoblastic cells. Basic FGF significantly inhibited the osteoclast-like cell formation, induced by 1α,25-dihydroxyvitamin D₃[1α, 25(OH)₂D₃] when the cytokine was added to the culture, at an intermediate stage, suggesting that bFGF inhibits the differentiation of the osteoclast progenitors. With regard to target cells, bFGF directly affected ST2; it increased [³H]thymidine uptake and decreased the number of alkaline phosphatase-positive cells. In contrast, bFGF had no inhibitory effect on the colony formation of bone marrow cells induced by macrophage colony stimulating factor in methylcellulose culture. In addition, ST2 cells treated with bFGF produced similar amounts of colony forming activity to those without the cytokine. These findings indicated that the bFGF is not involved in the proliferation of progenitor cells even in the presence of ST2 cells. Furthermore, bFGF inhibited osteoclast-like cell formation induced not only by 1α,25(OH)₂D₃, but also by prostaglandin E₂ and by interleukin-11. These results suggest that bFGF inhibits the common site of osteoclast-like cell formation, as induced by different mechanisms. Our data also indicated that the target cells for bFGF in inhibiting osteoclast formation are not osteoclast progenitors but stromal cells such as ST2 and osteoblastic cells, which support osteoclast development. © 1996 Wiley-Liss, Inc.     

Acidic fibroblast growth factor in the developing rat embryo

Compared to basic fibroblast growth factor (bFGF), a widely distributed, broad spectrum mitogen and mesoderm inducer, acidic fibroblast growth factor (aFGF) is reported to have an essentially neural distribution and to be undetectable in the early embryo. In the present investigation, we used immunoblotting and immunochemistry to assess the cellular and tissue distributions of aFGF and bFGF in 11-20-d rat embryos. Immunoblotting of crude and heparin-bound embryo extracts revealed faint bands at the expected 17-18-kD and predominant bands at an apparent molecular mass of 26 to 28-kD (despite reducing conditions) using multiple specific antibodies for aFGF and bFGF. Pretreatment with 8 M urea yielded 18-20-kD aFGF and bFGF and some 24-26-kD bFGF. Immunoreactivity for both aFGF and bFGF was positive and similar in the cytoplasm, nuclei, and extracellular matrix of cells of neuroectodermal and mesodermal origin, while it was negative in endoderm-derived cells. The distribution of immunoreactive aFGF and bFGF also showed changes during development that were associated with the process of cellular and tissue differentiation. For example, intensity and extent of immunoreactivity for both peptides progressively increased in the middle layer of the spinal cord with increasing differentiation of the neural cells. The immunostaining patterns were very similar for aFGF and bFGF for each organ and at each stage. In conclusion, high molecular mass forms of immunoreactive aFGF and bFGF are present in the rat embryo. Acidic FGF and bFGF are both widely distributed in tissues of neuroectodermal and mesodermal origin, and their distribution was very similar.     

Fibroblast Growth Factors Stimulate Protein Tyrosine Phosphorylation and Mitogen-Activated Protein Kinase Activity in Primary Cultures of Hippocampal Neurons

Abstract: Fibroblast growth factors (FGFs) are not only mitogens, but they also promote the differentiation of various cell types. For instance, basic FGF (bFGF) provides a critical trophic support for hippocampal neurons in culture. To elicit their biological effects, FGFs interact with high-affinity receptors that are transmembrane proteins with a cytoplasmic portion containing a tyrosine kinase activity. The tyrosine phosphorylation pattern was examined in primary cultures of hippocampal neurons derived from rat embryos. In these cultures grown for 3 days in the absence of serum, the addition of bFGF causes a rapid increase of tyrosine phosphorylation for various proteins with an optimal level after 5 min of bFGF exposure. Concomitantly, bFGF activates mitogen-activated protein kinase (MAP kinase) activity measured with a selective MAP kinase peptide. The activity increased rapidly after the addition of bFGF and remained elevated even when cultures were treated for 1 h with bFGF. Both acidic and basic FGF were able to enhance protein tyrosine phosphorylation and MAP kinase activity, whereas nerve growth factor and epidermal growth factor did not elicit any of these responses. These data indicate that some of the transduction signals (i.e., tyrosine phosphorylation and activation of MAP kinase) that have been described for the proliferative effect of FGFs are also involved when FGFs act as trophic factors for postmitotic neurons in culture.     

Overexpression of A-myb induces basic fibroblast growth factor-dependent proliferation of chicken neuroretina cells.

A-Myb behaves similarly to c-Myb in chicken neuroretina cells in its ability to induce fibroblast-like differentiation, to promote growth in the presence of basic fibroblast growth factor (bFGF), and to induce Pax-6 and mim-1 expression. The one difference between c-Myb and A-Myb in these cells is that the former but not the latter protein causes colony formation in soft agar in the presence of bFGF.     

Epidermal Growth Factor and Basic Fibroblast Growth Factor Have Independent Actions on Mesencephalic Dopamine Neurons in Culture

Abstract: Epidermal growth factor (EGF) and basic fibro-blast growth factor (bFGF) are both trophic for dopamine neurons s in cultures of dissociated embryonic rat mesen-cephaion, but the significance of this apparent overlap in neurotrophic activity is not yet known. In this study, we investigated the mechanisms of action of these two growth factors and the potential relationship between them, Using a nuclease protection assay, we determined that bFGF mRNA was expressed in the cultures. Double-label immunocytochemistry revealed that bFGF immunore-active material could be detected in tyrosine hydroxylase immunoreactive neurons and glial fibrillary acidic protein immunoreactive astrocytes. EGF treatment increased bFGF mRNA content per culture dish. As we have previously demonstrated that EGF exerts its dopaminergic neurotrophic activity via an intermediate cell type, studies were designed to address whether the pathway by which EGF acts on dopaminergic neurons is mediated by the release of bFGF. However, the trophic action of EGF on dopamine neurons, represented by high-affinity neuronal dopamine uptake, could not be blocked by immunoneutralization of bFGF, suggesting that the actions of EGF were not mediated by bFGF release. The time course of the effects of EGF and bFGF on dopamine uptake were similar, with significant increases detectable only after 5 days in culture. Both growth factors were active in the picomolar-to-nannomolar range with maximal trophic activity between 0.4 and 2.5 n M. EGF, however, was the more potent mitogen under these conditions. When cultures were simultaneously incubated with maximal concentrations of EGF and bFGF, the effect on dopamine uptake was significantly greater than with either growth factor alone and, in fact, approximated the sum of the individual effects. On the basis of these results we conclude that these growth factors have independent effects on dopamine neurons of the mesencephalon.