VEGF及其受体表达与垂体腺瘤血管生成和侵袭性的关系

目的探讨血管内皮生长因子(VEGF)与受体KDR在人垂体腺瘤中的表达,及其与血管形成和肿瘤侵袭性的关系。方法结合鞍底硬脑膜病理检查和影像学表现,将肿瘤的侵袭程度分为4级。采用免疫组织化学S-ABC法和RT-PCR检测VEGF及KDR的表达;采用免疫组化S-ABC法检测CD31,计算微血管密度(MVD);并对实验数据进行统计学分析。结果 VEGF、KDR在侵袭性垂体腺瘤的肿瘤细胞和血管内皮细胞均有表达;而在非侵袭性垂体腺瘤中,主要在肿瘤细胞中表达,很少在血管内皮细胞表达。随侵袭性程度的增加,VEGF和KDR蛋白、mRNA的表达相应增加,1级与0级、3级与2级比较,差异均有统计学意义(P<0.01),但1级与2级比较,差异无统计学意义(P>0.05)。VEGF和KDR高表达组MVD明显高于低表达组(P<0.01)。结论 VEGF可能通过其受体KDR协同促进垂体腺瘤血管的生成刺激垂体腺瘤生长和侵袭。     

血管内皮生长因子及其受体表达和侵袭性垂体腺瘤血管生成关系的研究

目的研究血管内皮生长因子(VEGF)及其受体Flt-1在人垂体腺瘤中的表达,探讨其表达变化、微血管密度(MVD)与侵袭性垂体腺瘤血管生成的关系.方法采用免疫组织化学技术检测52例垂体腺瘤的VEGF及其受体表达水平,同时检测CD34表达,用于测定垂体腺瘤的MVD,比较其在侵袭性和非侵袭性垂体腺瘤中的差异.结果VEGF及其受体和MVD与垂体腺瘤的侵袭性密切相关(P＜0.01).结论VEGF可能通过促进新生血管形成刺激垂体腺瘤生长和侵袭,其作用机制有待进一步研究.     

侵袭性垂体腺瘤血管增殖相关因子研究进展

近年来对垂体腺瘤侵袭性的研究中,血管增殖相关因子是一个重要研究方向。与血管增殖有关的CD系列因子、微血管密度(MVD)、血管内皮生长因子(VEGF)、碱性成纤维生长因子(bFGF)、凝血酶敏感蛋白(TSP1)与转化生长因子B(TGFB)等根据各自的机理,在肿瘤血管的增殖中起着重要的作用,与垂体腺瘤的侵袭性关系密切。对这些血管增殖相关因子的研究可能为我们评估和治疗侵袭性垂体腺瘤提供一个新的方法。     

微血管密度及血管内皮生长因子表达与垂体瘤侵袭性的关系

目的探索垂体瘤微循环与侵袭性的关系及其临床意义。方法采用免疫组化技术检测了42例垂体瘤中血管内皮生长因子(VEGF)蛋白表达,同时染色VonWillebrand因子显示血管内皮细胞以检测肿瘤内微血管密度MVD,分析VEGF蛋白表达及MVD与垂体瘤海绵窦侵袭性的关系。结果VEGF蛋白表达和MVD与垂体瘤的海绵窦侵袭性均有关(两者均P<0.001)。结论VEGF与新生血管形成在垂体瘤的侵袭性生物学行为中具有重要的作用。     

垂体腺瘤中MMP-9与VEGF的表达及其与侵袭性的关系

目的探讨基质金属蛋白酶-9(MMP-9)与血管内皮生长因子(VEGF)在垂体腺瘤中的表达及其与垂体腺瘤侵袭性的关系。方法应用免疫组化染色法和逆转录聚合酶链式反应(RT-PCR)方法检测侵袭性(20例)和非侵袭性(10例)垂体腺瘤组织标本中MMP-9与VEGF的表达,分析二者与垂体腺瘤侵袭性的关系及二者的相关性。结果侵袭性垂体腺瘤组MMP-9、VEGF的蛋白及mRNA表达均较非侵袭性腺瘤组显著增高(P<0.01)。在蛋白水平,侵袭性腺瘤组中MMP-9与VEGF表达水平无显著性相关;在mRNA水平,侵袭性腺瘤组中MMP-9与VEGF表达水平成正相关(P<0.05)。结论侵袭性垂体腺瘤的生物学行为与MMP-9基因表达增高及血管生成正调节因子VEGF表达上调有关。MMP-9与VEGF在新生血管形成过程中存在着内在联系。     

VEGF在人脑胶质瘤中的表达与肿瘤增殖及肿瘤血管生成的关系

目的研究血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)在人脑胶质瘤中的表达与肿瘤增殖及血管生成的关系。方法应用免疫组化技术和形态定量分析法,检测98例手术切除脑胶质瘤中VEGF表达、PCNA标记指数(PCNA LI)、微血管密度(Microvessel density,MVD)表达。结果(1)肿瘤细胞及血管内皮细胞均可以表达VEGF,阳性颗粒分布于肿瘤胞浆中;(2)高级别肿瘤PCNA、LI、MVD显著高于低级别肿瘤(P<0.05);VEGF表达阳性肿瘤的PCNA、LI、MVD显著高于VEGF表达阴性肿瘤(P<0.05);(3)在星形细胞肿瘤中,随着MVD的增大,VEGF在肿瘤血管内皮的染色率逐渐增加,与肿瘤的MVD存在正相关关系(r值为0.44,P<0.01)。结论脑胶质瘤的VEGF表达与MVD呈正相关关系,VEGF在肿瘤细胞增殖及血管再生过程中起重要作用。     

Survivin、VEGF、MVD的表达与垂体腺瘤侵袭性的关系

目的探讨凋亡抑制基因Survivin、血管内皮生长因子（VEGF）、微血管密度（MVD）的表达与垂体腺瘤侵袭性的关系。方法采用免疫组化S-P法检测上述三者在50例垂体瘤中的表达。结果侵袭组和非侵袭组的Survivin、VEGF、MVD表达均有显著性差异,Survivin的高表达将直接导致血管发生显著增强,其高表达与肿瘤细胞的侵袭性呈正相关．VEGF具有促进肿瘤新生血管形成的作用,MVD则是血管形成的量化指标。结论Survivin、MVD、VEGF可作为判断垂体腺瘤侵袭性和评估预后的良好生物学指标。     

内皮抑素、血管内皮生长因子与脑梗死

内皮抑素(Endostatin)能特异性抑制血管内皮细胞的增生、迁移,并诱导其凋亡,从而抑制新生血管的形成;还可抑制斑块内膜血管生成从而抑制动脉粥样硬化斑块的生长。血管内皮生长因子(VEGF)可诱导内皮细胞增殖,促进新生血管形成。内皮抑素和VEGF作为血管形成的调节因子,可能与脑梗死的发生、发展及转归密切相关。     

血管内皮细胞生长因子和脑肿瘤的研究进展

肿瘤血管的生成与肿瘤的生长、转移密切相关，而新生血管的形成是由多种血管生长因子介导实现的，如成纤维细胞生长因子(bFGF)、胎盘生长因子(PIGF)及血管内皮细胞生长因子(VEGF)等，其中以血管内皮细胞生长因子(VEGF)在脑肿瘤血管生成中最为重要。本就VEGF与脑肿瘤的关系作一综述。     

MMP-9、VEGF和p16在垂体腺瘤中的表达及其与该腺瘤侵袭性的相关性研究

目的研究基质金属蛋白酶-9(MMP-9)、血管内皮细胞生长因子(VEGF)和p16在侵袭性和非侵袭性垂体腺瘤中的表达及其与垂体腺瘤侵袭性的相关性。方法用免疫组化方法检测MMP-9、VEGF和p16在30例侵袭性和24例非侵袭性垂体腺瘤中的表达水平,并分析其垂体腺瘤侵袭性的关系。结果 MMP-9、VEGF标记指数在侵袭性垂体腺瘤中分别为(39.44±5.61)%和(24.28±3.94)%,均较非侵袭性垂体腺瘤中的(22.17±4.32)%和(17.62±1.89)%显著增高(P0.01)。p16在非侵袭性垂体腺瘤中的标记指数为(27.49±4.07)%,较侵袭性垂体腺瘤的标记指数(20.18±3.26)%显著增高(P0.01)。垂体腺瘤的侵袭性与MMP-9和VEGF的表达呈正相关(P0.05),而与p16表达呈负相关(P0.05)。结论 MMP-9、VEGF的表达增高和p16的表达降低与垂体腺瘤的侵袭性密切相关。     

Heterogeneity of human neuroblastoma cell lines in their proliferative responses to basic FGF,NGF, and EGF: Correlation with expression of growth factors and growth factor receptors

Growth factors can induce both proliferation or differentiation of neuroblastoma (NB) cells through interaction with specific receptors. Using two automated colorimetric assays for determinations of cell numbers, the present study demonstrates that (a) different NB and neuroepithelioma cell lines show distinct responses, both qualitatively and quantitatively, to basic FGF (bFGF), NGF, and EGF(b) even closely related NB cell lines (e.g., SK-N-SH, SH-SY5Y, and SHEP) do not respond uniformly to these factors; c) responses of the two neuroepithelioma cell lines employed (SK-N-MC and CHP-100) differ, but match those of certain NB cell lines; and d) two growth factors, bFGF and EGF, may both stimulate or inhibit proliferation, depending on the cell line studied. Specifically, IMR-32, SK-N-SH, and SH-SY5Y showed a mitogenic response to each growth factor. Maximal proliferative responses ranged from 204–355% as compared to controls (100%). GICAN was stimulated by NGF (199%), and SK-N-MC and NMB by EGF (282 and 140%, respectively), but other factors were ineffective. CHP-100 and GIMEN were inhibited by bFGF. NGF and EGF were not effective on CHP-100 cells, while EGF caused an arrest of mitogenic activity in GIMEN cells, and NGF stimulated their proliferation. Cell lines SHEP and LAN1 did not respond to any factor. To begin to analyze putative relationships of growth factor responsiveness and growth factor/growth factor receptor expressions, IMR-32, GIMEN, and LAN1 cell lines were studied for the presence of bFGF, NGF, FGF receptors (R)-1 (flg) and FGFR-4, trk, and low-affinity NGF receptor (p75) mRNAs. All three cell lines expressed bFGF and NGF mRNA, but not the FGFR-1, FGFR-4, trk, and p75 mRNAs. These results suggest extremely diverse patterns of NB/neuroepithelioma cell responsiveness to “mitogenic” growth factors and no overt correlation between such responses and growth factor/growth factor receptor expression. © 1995 Wiley-Liss, Inc.     

Insulin-like and fibroblast growth factors in spinal cords,nerve roots and skeletal muscle of human controls and patients with amyotrophic lateral sclerosis

Insulin-like growth factors (IGF-I and IGF-II) and fibroblast growth factors [acidic FGF (aFGF) and basic FGF (bFGF)] are trophic for motor neurones in vitro and (in laboratory animals) in vivo. An immunohistochemical investigation was performed on the distribution of these factors in the neuromuscular system of control patients and patients with amyotrophic lateral sclerosis (ALS). Comparisons were made with rat tissue. IGF-I immunoreactivity (IGF-I-IR) was seen in motor neurone cell bodies and axons, astroglia and Schwann cells, and in muscle fibres. IGF-II-IR was weak in all these cells. aFGF-IR was present in motor neurone cell bodies and axons, oligodendroglia and muscle fibres, but was not demonstrable in Schwann cells. bFGF-IR was present in motor neurone cell bodies and axons, and in astroglia, but was not seen in Schwann cells or muscle fibres. The distribution of the IGFs and FGFs in material from motor neurone disease (MND) and controls was similar. A role for any of these factors in the etiology of MND is, therefore, unlikely. IGF-I-IR and aFGF-IR were stronger in type II than in type I muscle fibres and were increased in denervated fibres. Species differences were found for IGF-I and bFGF. The function of these factors is apparently not entirely similar in humans and rats.Supported by a grant from the Dutch Foundation for Research into Spinal Muscular Atrophy and ALS     

Interaction between cAMP elevation, identified growth factors, and serum components in regulating Schwann cell growth.

Most previous studies on Schwann cell proliferation in vitro have used serum-containing media. This complicates the analysis of agents required for cell division since serum contains an ill-defined mixture of hormones and growth factors. Serum-free medium has therefore been used to analyse the response of Schwann cell to previously identified Schwann cell mitogens. Serum factors were not necessary for DNA synthesis in response to platelet-derived growth factor, basic fibroblast growth factor, or glial growth factor, provided they were used in combination with forskolin to elevate intracellular cAMP. Transforming growth factor beta 1, a Schwann cell mitogen in serum, was not mitogenic under these conditions. Neither the growth factors nor forskolin were effective when used alone. Growth control was analysed further using long-term cultured Schwann cells that had spontaneously immortalized. Measurements of endogenous cAMP levels in short- and long-term Schwann cells revealed that long-term cells had two to three times higher basal cAMP levels. As predicted by these findings, platelet-derived growth factor, basic fibroblast growth factor, and glial growth factor stimulated DNA synthesis in long-term cells without requiring costimulation by agents which elevate cAMP (while transforming growth factor beta 1 had no effect).(ABSTRACT TRUNCATED AT 250 WORDS)     

PC12h-R cell,a subclone of PC12 cells,shows EGF-induced neuronal differentiation and sustained signaling

Unlike nerve growth factor (NGF), epidermal growth factor (EGF) does not induce neuronal differentiation but promotes proliferation of the rat pheochromocytoma PC12 cells. We found that PC12h-R, a subclone of PC12 cells, differentiated into neuron-like cells in response to EGF as well as to NGF. PC12h-R cells treated with EGF extended neurites, attenuated cell proliferation, and increased the levels of tyrosine hydroxylase protein synthesis and of acetylcholinesterase activity as those treated with NGF. The EGF-induced differentiation of PC12h-R cells was not mediated by the indirect activation of p140^trkA by EGF. In addition, EGF induced the sustained tyrosine phosphorylation of the EGF receptor, mitogen-activated protein (MAP) kinases, and 46 and 52 kDa proteins, and the prolonged activation of MAP kinases in PC12h-R cells compared with the parent PC12h, which does not show EGF-induced differentiation. The response of PC12h-R cells to EGF was not simply due to an increase in the level of EGF receptor protein. These results indicated that the duration of EGF-induced signaling might determine the cellular response of PC12 cells between cell proliferation and neuronal differentiation. © 1996 Wiley-Liss, Inc.     

Nerve growth factor affects defense-related behaviors, but not lordosis, in ovariectomized, estrogen-treated rats

Effects of NGF and anti-NGF on estrogen-sensitive behaviors were examined in ovariectomized, estrogen-treated rats. Intracerebroventricular (i.c.v.) administration of NGF resulted in a significant decrease in body weight. Daily treatment with low levels of estradiol resulted in a steady increase in lordosis behavior as reflected by average lordosis quotient and lordosis score. No effects of NGF or anti-NGF on lordosis behavior were detected. Estrogen treatment also resulted in a significant increase in the number of vocalizations elicited from female controls by male contact during sex behavior. NGF-treatment enhanced this effect, resulting in significantly more vocalizations elicited earlier in the course of estrogen treatment than were elicited from non-NGF-treated controls. These effects were blocked by progesterone. An increase in the number of rejections elicited by male contact during sex behavior was also observed in NGF-treated animals relative to controls. In addition, i.c.v. infusions of anti-NGF prevented the estrogen-mediated increase in elicited vocalizations, suggesting that NGF may have a physiological role in regulating this behavior. These data implicate NGF in the regulation of specific defense-related behaviors in estrogen-treated rats. Effects of NGF and anti-NGF on immunocytochemical staining for p75^NGFR- and ChAT-like immunoreactivity were also analyzed and are discussed.     

Differential adaptations of insulin-like growth factor-I, basic fibroblast growth factor, and leukemia inhibitory factor in the plantaris muscle of rats by mechanical overloading: an immunohistochemical study

We investigated changes in several growth factors in the rat plantaris muscle produced by mechanical overloading by ablation of synergists using immunohistochemistry. At 1 and 3 days post surgery, the insulin-like growth factor-I (IGF-I) level was slightly increased in the cytosol and markedly increased in the invading cells of the extracellular space. Thereafter, the IGF-I immunoreactivity evoked by overloading rapidly decreased to the normal level. The level of leukemia inhibitory factor (LIF), which was not shown to change at 1 day post surgery, was increased in the cytosol at 3, 5, 7 and 10 days and at 2 weeks. Basic fibroblast growth factor (bFGF) immunoreactivity did not change during the entire period of overloading (1 day–3 weeks post surgery). These results indicate that the elevations of the levels of IGF-I and LIF show differential time course in the plantaris muscle subjected to functional overload. Furthermore, bFGF appears not to be related to the compensatory hypertrophy produced by overloading. Received: 20 June 1997 / Revised, accepted: 8 September 1997     

bFGF和PDGF-B蛋白在脑缺血再灌注大鼠模型中的表达和血管形成的研究

目的 探讨脑缺血再灌注大鼠不同时间碱性成纤维细胞生长因子(bFGF)和血小板源性生长因子-B(PDGF-B)的表达水平及其与血管形成的关系。方法 采用线栓法制备大鼠大脑中动脉局灶性脑缺血再灌注(MCAO/R)模型,分为假手术组和MCAO/R组,MCAO/R组缺血2 h后根据再灌注时间窗的不同分为0、6、24 h、3、7、14、21 d共7组,应用HE染色观察病理变化并测定脑梗死体积,用免疫组化法检测CD34蛋白的表达水平并计数微血管密度(MVD),用免疫组化法检测bFGF和PDGF-B蛋白的表达水平。结果 bFGF蛋白表达水平在MCAO/R 6 h后即开始升高,3 d到达高峰,7 d开始降低。PDGF-B蛋白表达水平在MCAO/R 24 h后明显升高,3 d到达高峰,7 d有所下降,持续到14 d左右。MVD表达在MCAO/R 3 d开始升高,7 d到达高峰。bFGF和PDGF-B蛋白表达水平与MVD变化呈正相关(P<0.01)。结论 局灶性脑缺血再灌注损伤可诱导bFGF、PDGF-B和新生血管表达增加,激活内源性脑保护机制。     

Neuron-enriched cultures of adult rat dorsal root ganglia: establishment, characterization, survival, and neuropeptide expression in response to trophic factors

It is unknown whether adult dorsal root ganglion (DRG) neurons require trophic factors for their survival and maintenance of neuropeptide phenotypes. We have established and characterized neuron-enriched cultures of adult rat DRGs and investigated their responses to nerve growth factor (NGF), ciliary neuronotrophic factor (CNTF), pig brain extract (PBE, crude fraction of brain-derived neuronotrophic factor, BDNF), and laminin (LN). DRGs were dissected from levels C1 through L6 and dissociated and freed from myelin fragments and most satellite (S-100-immunoreactive) cells by centrifugation on Percoll and preplating. The enriched neurons, characterized by their morphology and immunoreactivity for neuron-specific enolase, constituted a population representative of the in vivo situation with regard to expression of substance P (SP), somatostatin (SOM), and cholecystokinin-8 (CCK) immunoreactivities. In the absence of trophic factors and using polyornithine (PORN) as a substratum, 60-70% of the neurons present initially (0.5 days) had died after 7 days. LN as a substratum did not prevent a 30% loss of neurons up to day 4.5, but it subsequently maintained DRG neurons at a plateau. This behavior might reflect a cotrophic effect of LN and factors provided by non-neuronal cells, whose proliferation between 4.5 and 7 days could not be prevented by addition of mitotic inhibitors of gamma-irradiation. CNTF, but not NGF, slightly enhanced survival at 7 days on either PORN or LN. No neuronal losses were found in non-enriched cultures or when enriched neurons were supplemented with PBE, indicating that non-neuronal cells and PBE provide factor(s) essential for adult DRG neuron survival. Proportions of SP-, SOM-, and CCK-immunoreactive cells were unaltered under any experimental condition, with the exception of a numerical decline in SP cells in 7-day cultures with LN, but not PORN, as the substratum. Our data, considered in the context of recent in vivo and vitro studies, suggest that a combination of trophic factors or an unidentified factor, rather than the established molecules NGF, CNTF, and BDNF, which address embryonic and neonatal DRG neurons, are required for the in vitro maintenance of adult DRG neurons.     

A simple, objective method to measure the activity of factors that promote neuronal survival

The activity of factors that promote short-term neuron survival (neurotrophic or neuronotrophic factors) can be quickly and objectively determined by measuring the incorporation of radiolabelled leucine or methionine during the 24 h duration of the assay. Other types of radiolabelled small molecules, such as choline or 2-deoxyglucose, can also be used but their signal/noise ratios are not as favorable under the optimal assay culture conditions. The neuronotrophic titers determined by amino acid uptake are the same as those estimated by microscopic counting of live and dead neurons.