外源性碱性成纤维细胞生长因子对缺血大鼠脑内源性碱性成纤维细胞生长因子表达的影响

目的 研究外源性碱性成纤维细胞生长因子(bFGF)缩小局灶性脑缺血梗死灶的机制。方法 用免疫组化ABC法检测在局灶性脑缺血模型上给予生理盐水或bFGF后早期生长反应蛋白-1(Egr-1)，bFGF，碱性成纤维细胞生长因子受体(bFGFR)的动态表达。结果 给药组在3h～3d各时间段梗死灶均有不同程度的缩小。对照组和给药组Egr-1表达均表现为3～6h的增强过程，但给药组更强于对照组。对照组12h见有bFGF表达增强，而bFGFR表达3h到达高峰，6h起下降，12h时bFGFR的表达已恢复至正常水平(出现了配体和受体表达时相上不匹配)。给药组bFGF表达提前且增强，3h即见有bFGF表达增强，6h时出现第一峰，从而与bFGFR 3～6h的表达增强过程相吻合。结论 外源性bFGF能缩小梗死灶，该神经保护作用是通过Egr-1蛋白高表达使内源性bFGF的表达增高且提前，从而与bFGFR的表达增强过程重叠而实现的。     

Apoptosis occurs in the oligodendroglial lineage,and is prevented by basic fibroblast growth factor

During the perinatal period, oligodendroglial precursor cells proliferate rapidly, then cease dividing and differentiate into oligodendroglia. Many of these newly formed oligodendroglia are destined to die. We now demonstrate that oligodendroglia generated in passaged cultures of rat forebrain oligodendroglial precursor cells after removal of basic fibroblast growth factor (basic FGF) from the medium often undergo internucleosomal DNA nicking and nuclear fragmentation, features characteristic of apoptosis. These alterations are rare in cultures maintained continuously in basic FGF. As in many other cellular lineages susceptible to apoptosis, these degenerative changes can be prevented by treatment with the endonuclease antagonist, aurintricarboxylic acid, or by inhibiting de novo RNA or protein synthesis. Supplementation of the basic FGF-free medium with insulin, insulin-like growth factor-1, platelet-derived growth factor, or ciliary neuronotrophic growth factor also diminishes DNA nicking. Both oligodendroglial differentiation and DNA nicking are induced in basic FGF-treated cultures by inhibiting DNA synthesis with aphidicholin or excess thymidine, thus suggesting a close linkage between the anti-apoptotic, anti-differentiation, and mitogenic effects of basic FGF on the oligodendroglial lineage. © 1995 Wiley-Liss, Inc.     

Angiogenic and inflammatory responses following skeletal muscle injury are altered by immune neutralization of endogenous basic fibroblast growth factor, insulin-like growth factor-1 and transforming growth factor-β1

Injured skeletal muscle degeneration comprises early microvascular changes and inflammatory cell infiltration, possibly under the control of several growth factors. We have studied the role of basic fibroblast growth factor (bFGF), insulin-like growth factor-1 (IGF1), and transforming growth factor beta-1 (TGFβ1), by injecting specific anti-growth factor neutralizing antibodies into mouse extensor digitorum longus muscle at the time of injury (denervation and devascularization). Four days later, at the height of damaged myofiber phagocytosis, we assessed quantitatively revascularization, phagocytic activity, and inflammation. The immune neutralization of bFGF reduced the number of capillaries, macrophages and mast cells, and delayed necrotic myofiber phagocytosis. The immune neutralization of IGF1 or TGFβ1 promoted muscle revascularization, macrophage infiltration and necrotic myofiber phagocytosis. While IGF1 neutralization reduced the number of mast cells and did not modify that of T-cells or neutrophils, TGFβ1 neutralization increased the number of all of these cells. This study strongly suggests differing roles for bFGF, IGF1 and TGFβ1 in angiogenic and inflammatory responses during muscle degeneration, apart from their known effects on the behaviour of myogenic cells.     

碱性成纤维生长因子和神经生长因子联合应用培养成年大鼠海马神经干细胞向神经元样细胞的分化

背景：影响神经干细胞向神经元分化的因素很多,各种营养因子可以不同程度地刺激神经干细胞向神经元分化,如何使神经干细胞大量分化为神经元是研究的热点问题。 目的：观察联合应用碱性成纤维生长因子和神经生长因子对成年大鼠海马神经干细胞为神经元的影响。 方法：无菌条件下分离大鼠脑海马组织,传至第4代克隆球直径约为200 μm时,滴加DMEM/F12+2% B27+20 μg/L表皮生长因子+20 μg/L碱性成纤维细胞生长因子,进行单细胞克隆培养,传代的神经干细胞分成空白对照组、碱性成纤维细胞生长因子组、神经生长因子组、碱性成纤维细胞生长因子+神经生长因子组。观察传代后的克隆球进行神经干细胞免疫细胞化学染色鉴定,计数神经元特异性烯醇化酶阳性细胞率,检测神经干细胞向神经元的分化情况。 结果与结论：①单细胞克隆培养后,克隆球细胞表达巢蛋白,诱导分化后神经元特异性烯醇化酶、胶质纤维酸性蛋白均呈阳性表达。②与空白对照组神经干细胞分化为神经元的比例比较,碱性成纤维细胞生长因子组、神经生长因子组、碱性成纤维细胞生长因子组+神经生长因子组均明显提高(P < 0.05),且碱性成纤维细胞生长因子组+神经生长因子组神经元的比例最高(P < 0.05)。提示,碱性成纤维细胞生长因子可以提高神经生长因子诱和神经生长因子均可促进神经干细胞向神经元分化,且二者联合应用效果更佳。     

脓毒症大鼠模型脑胰岛素生长因子1表达的变化及影响

目的：探讨脓毒症大鼠模型胰岛素生长因子1（IGF-1）表达的变化及影响。方法采用盲肠结扎穿孔法（CLP）制作脓毒症大鼠模型,应用免疫荧光染色观察皮层IGF-1阳性细胞, western blot法检测IGF-1和caspase-3蛋白表达,TUNEL染色观察脑神经元凋亡。在脓毒症模型基础上,给予侧脑室定位注射IGF-1或生理盐水,相同方法检测caspase-3蛋白表达及脑神经元凋亡。结果与假手术组相比,脓毒症组大鼠皮层IGF-1阳性细胞数明显减少,caspase-3表达增高,IGF-1表达减低,神经元凋亡增加（均P＜0．05）。侧脑室注射IGF-1后,caspase-3表达和神经元凋亡较假手术组无明显变化;而侧脑室给予生理盐水大鼠caspase-3表达和神经元凋亡与脓毒症组相似。结论脓毒症大鼠的脑皮层IGF-1表达明显减低,细胞凋亡增多。给予外源性IGF-1后,细胞凋亡减少。提示IGF-1可能通过抑制caspase-3的上调对脓毒症大鼠起到脑保护作用。     

托吡酯对慢性癫(癎)大鼠海马碱性成纤维细胞生长因子表达的影响

目的研究托吡酯（TPM）对慢性癫痫大鼠海马碱性成纤维细胞生长因子（bFGF）表达的影响。方法制作戊四氮（PTZ）慢性癫痫点燃大鼠模型，分为PTZ组、TPM组及正常对照组，每组又以5d、10d、15d3个时间点各分为3小组。免疫组化法观察各组海马CAl、CA3区及齿状回bFGF表达，HE染色观察病理形态学改变。结果（1）行为学观察：PTZ组和TPM组在癫痫发作上无明显差别。（2）bFGF表达：①各组齿状回区bFGF表达：PTZ组和TPM组各时点表达不断增高，与正常对照组比较差异有统计学意义（均P〈0．01），尤以10d及15d时增高更明显，与5d时比较差异有统计学意义（均P〈0．05）。②各组CAl区bFGF表达：PTZ组各时点均有明显表达，且随时间延长而表达不断增高，各时点比较差异有统计学意义（均P〈0．01），与正常对照组比较差异有统计学意义（均P〈0．01）；TPM组在5d时与正常对照组比较差异有统计学意义（P〈0．01），而10d、15d时逐渐下降，接近正常对照组水平。③各组CA3区bFGF表达：5d时3组比较差异无统计学意义。但PTZ组和TPM组在10d时与正常对照组比较差异有统计学意义（P〈0．01），PTZ组在15d时和TPM组及正常对照组比较差异有统计学意义（均P〈0．01）。（3）病理形态学改变：PTZ组和TPM组的海马CAl、CA3区尤其是CAl区可见较多神经元发生变性和坏死，PTZ组更显著。结论PTZ点燃过程中海马bF-GF表达增高，尤其在CAl区，且随时间延长有表达不断增高的趋势。TPM可能通过减少海马神经元损伤而明显下调海马CAl、CA3区bFGF的表达。     

靶向AKT1和COX-2的RNAi抑制U251胶质瘤细胞侵袭的体外实验

目的应用RNA干扰(RNA interference,RNAi)技术敲低恶性胶质瘤细胞系U251中AKT1和COX-2表达后,在体外对细胞侵袭转移的抑制作用,初步探讨其可能的作用机制。方法构建重组腺病毒载体rAd5-A-C同时搭载靶向AKT1和COX-2的shRNA干扰序列,将其转染至恶性胶质瘤细胞系U251细胞。Realtime PCR检测RNAi后目的基因mRNA的表达水平,Western Blot检测目的基因及MMP-2、MMP-9、TIMP-2的表达情况。酶联免疫吸附试验检测转染前后分泌到细胞外的MMP-2和MMP-9的浓度变化。划痕实验和Transwell实验评价肿瘤细胞转染前后的细胞侵袭能力的变化。结果rAd5-A-C转染组AKT1和COX-2的mRNA和蛋白表达均明显抑制;MMP-2、MMP-9表达下调,TIMP-2表达则上调。ELISA检测胞外MMP-2、MMP-9浓度明显减低;划痕实验显示细胞转移运动能力明显减弱,Transwell体外侵袭实验结果显示穿过细胞数明显减低(P0.001)。结论重组腺病毒介导的RNAi技术可以序列特异性地抑制U251细胞AKT1和COX-2的表达,在体外对U251细胞侵袭转移产生明显抑制作用,可能成为恶性胶质瘤治疗的新策略。     

Distribution and localization of fibroblast growth factor-8 in rat brain and nerve cells during neural stem/progenitor cell differentiation

The present study explored the distribution and localization of fibroblast growth factor-8 and its potential receptor,fibroblast growth factor receptor-3,in adult rat brain in vivo and in nerve cells during differentiation of neural stem/progenitor cells in vitro.Immunohistochemistry was used to examine the distribution of fibroblast growth factor-8 in adult rat brain in vivo.Localization of fibroblast growth factor-8 and fibroblast growth factor receptor-3 in cells during neural stem/progenitor cell differentiation in vitro was detected by immunofluorescence.Flow cytometry and immunofluorescence were used to evaluate the effect of an anti-fibroblast growth factor-8 antibody on neural stem/progenitor cell differentiation and expansion in vitro.Results from this study confirmed that fibroblast growth factor-8 was mainly distributed in adult midbrain,namely the substantia nigra,compact part,dorsal tier,substantia nigra and reticular part,but was not detected in the forebrain comprising the caudate putamen and striatum.Unusual results were obtained in retrosplenial locations of adult rat brain.We found that fibroblast growth factor-8 and fibroblast growth factor receptor-3 were distributed on the cell membrane and in the cytoplasm of nerve cells using immunohistochemistry and immunofluorescence analyses.We considered that the distribution of fibroblast growth factor-8 and fibroblast growth factor receptor-3 in neural cells corresponded to the characteristics of fibroblast growth factor-8,a secretory factor.Addition of an anti-fibroblast growth factor-8 antibody to cultures significantly affected the rate of expansion and differentiation of neural stem/progenitor cells.In contrast,addition of recombinant fibroblast growth factor-8 to differentiation medium promoted neural stem/progenitor cell differentiation and increased the final yields of dopaminergic neurons and total neurons.Our study may help delineate the important roles of fibroblast growth factor-8 in brain activities and neural stem/progenitor cell differentiation.     

Chronic exercise accelerates the degeneration-regeneration cycle and downregulates insulin-like growth factor-1 in muscle of mdx mice

The aim of this study was to examine the effects of chronic running exercise on degenerative-regenerative processes in the hindlimb muscles of dystrophin-deficient mdx mice. The number of large-sized degenerative-regenerative groups (DRGs) was markedly decreased, whereas that of small-sized DRGs was unchanged by exercise. Expression of insulin-like growth factor-1 (Igf1), as well as a myogenic factor MyoD (Myod1), was downregulated in mdx muscles by exercise. The downregulation of Igf1 may well correlate with the decrease in the population of early regenerating fibers, which existed predominantly in DRGs, because IGF-1 was mainly localized in these fibers. Our data indicate that chronic exercise may accelerate the active cycle of degeneration-regeneration in mdx skeletal muscles. This means that mdx skeletal muscles can temporarily cope with work-induced injury by enhancing muscle regeneration and repair, but we speculate that an early decline of IGF-1 will accelerate age-dependent muscle wasting and weakness in the later stage of life in mdx mice.     

Effect of Ganoderma lucidum spore on expression of insulin-like growth factor-1, nuclear factor-kappa B, and neuronal apoptosis in the epileptic rat brain

BACKGROUND: It has been reported that Ganoderma lucidum spore powder, a very well known Chinese traditional medicine, can affect immunoregulation, free radical scavenging, and anti-hypoxia responses. OBJECTIVE: To investigate the effect of Ganoderma lucidum spore powder on expression of insulin-like growth factor-1 (IGF-1), nuclear factor-κB (NF-κB) and neuronal apoptosis in rats with pentylenetetrazol (PTZ)-induced epilepsy.DESIGN, TIME AND SETTING: A cellular and molecular biology experiment with randomized controlled study design was performed at the Central Laboratory of Basic Medical College of Jiamusi University from June to August 2005.MATERIALS: Thirty healthy, adult, male, Wistar rats were selected and randomly divided into 3 groups (10rats per group): control, epilepsy model, and Ganoderma lucidum spore powder. A sub-eclampsia PTZ dose (35 mg/kg) was intraperitoneally injected to induce epilepsy in the latter two groups. Wild Ganoderma lucidum spore powder (30 g/L) was provided by the wild Ganoderma lucidum plant nursery at Jiamusi,China. lmmunohistochemical detection and terminal deoxynucleotidyl transferase-mediate dUTP nick end-labeling (TUNEL) kits were purchased from Wuhan Boster Biological Technology Co., Ltd., China.METHODS: Ganoderma lucidum spore powder was intragastrically administered at a dose of 10.0 mL/kg,once a day for 28 days. In the epilepsy and control groups, an equivalent volume of normal saline was intragastrically administered.MAIN OUTCOME MEASURES: lmmunoreactivity for IGF-1 and NF-κB/P65 were detected by immunohistochemical staining. Neuronal apoptosis was detected using TUNEL methods.RESULTS: The hippocampus and cerebral cortex of rats with PTZ-induced epilepsy exhibited a higher number of apoptotic cells at high magnification (x400), compared with the control group. Expression of IGF-1and NF-κB were higher in the epilepsy group, compared with the control group (P < 0.01). In Ganoderma lucidum spore-treated rats, fewer apoptotic cells were observed in the hippocampus and cerebral cortex,expression of NF-κB/P65 was lower, and immunoreactivity to IGF-1 increased more distinctly, compared with the epilepsy group. In addition, seizure latency was longer on 17, 21, and 25 days post-PTZ treatment in the Ganoderma lucidum spore powder group, compared with the epilepsy group (P < 0.05 0.01).CONCLUSION: Ganoderma lucidum spore powder down-regulated expression of NF-κB in brain tissues of rats with PTZ-induced epilepsy, increased immunoreactivity to IGF-1, and inhibited neuronal apoptosis.These results indicated that Ganoderma lucidum spore powder has a neuroprotective effect.     

Knockdown of CDK2AP1 by RNA interference inhibits cell growth and tumorigenesis of human glioma

Abstract

Previous reports support the role of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) as a tumor suppressor that functions as a key player in cell cycle regulation. Although the misadjustment of CDK2AP1 has been revealed in several types of human malignancies, the functional role of CDK2AP1 in human glioma remains unknown. The present study was undertaken to investigate the effects of CDK2AP1 knockdown by RNA interference (RNAi) on glioma cell growth and tumorigenesis. We employed lentivirus-mediated RNAi to down-regulate CDK2AP1 expression in U251 and U373 cells. Knockdown of CDK2AP1 resulted in a significant reduction in U251 and U373 cell proliferation, as determined by MTT and colony formation assays. Cell cycle analysis showed CDK2AP1 silencing caused U251 cells arrest in G0/G1 phase, especially in the sub-G1 phase representing apoptotic cells. In vivo tumorigenesis was assessed using xenograft formation and CDK2AP1 depletion remarkably inhibited glioma growth and tumorigenesis. Taken together, these results suggest that CDK2AP1 siRNA may have an anti-tumorigenic effect on human glioma.     

碱性成纤维细胞因子在局灶性脑缺血后内源性神经干细胞增殖过程中对β-catenin的影响

BACKGROUND： The Wnt/β-catenin signaling pathway plays an important role in neural development. ,β-catenin is an important component of the Wnt/β-catenin signaling pathway. The Wnt signaling pathway has been shown to regulate the interaction of neural stem cells with the extracellular matrix.
OBJECTIVE： To investigate the effects of basic fibroblast growth factor （bFGF） on β-catenin protein and mRNA expression, and on hippocampal neural stem cell proliferation in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiology experiment was performed in Shenyang Medical College between August 2006 and August 2008. MATERIALS： A total of 72 healthy male Wistar rats, aged 3 months, were used in this study. bFGF was provided by Beijing SL Pharmaceutical Co.,Ltd., China. METHODS： Rats were randomly divided into 3 groups： sham-operated, ischemia/reperfusion, and bFGF-treated （n = 24 per group）. Focal cerebral ischemia/reperfusion was induced in rats from the ischemia/reperfusion group and the bFGF-treated group by 2 hour right middle cerebral artery occlusion and 2 hour restoration of blood flow using the suture method. The ischemia/reperfusion and bFGF-treated groups were intraperitoneally administered 500 IU/mL of bFGF, or the same volume of physiological saline, once a day at postoperative days 1 3, and once every 3 days thereafter. Simultaneously, the sham-operated group underwent experimental procedures identical to the ischemia/reperfusion and bFGF-treated groups, with the exception of ischemia/reperfusion induction and drug administration. At 2 hours, 2, 6, 13, and 20 days after ischemiaJreperfusion induction, 50 mg/kg bromodeoxyuridine （BrdU） was administered to each group, twice daily, to label proliferating neural stem cells. MAIN OUTCOME MEASURES： The effects of bFGF on BrdU labeling, and ,8 -catenin mRNA and protein expression, in neural stem cells were examined by immunohistochemistry, Western blot, RT-PCR, and in situ hybridization techniques. RESULTS： In the sham-operated group, only a few BrdU-immunoreactive neural stem cells were found. In the ischemia/reperfusion group, BrdU-immunoreactive cells began to increase from 3 days after ischemia/reperfusion induction, reached a peak level at 7 days, and gradually reduced from 21 days. At 3, 7, 14, and 21 days after ischemia/reperfusion induction, the numbers of BrdU-immunoreactive cells were significantly greater in the bFGF-treated group than in the ischemia/reperfusion group. The sham-operated group exhibited slight expression of β-catenin and β-catenin mRNA. In the ischemia/reperfusion group, the expression of β-catenin and β-catenin mRNA gradually increased with reperfusion time, peaked at 14 days after reperfusion, and gradually decreased thereafter; by 21 days, the expression was markedly lower. Following bFGF injection, the expression of hippocampal BrdU, β-catenin, and β-catenin mRNA had apparently increased in each group. CONCLUSION： bFGF promotes neural stem cell proliferation, and the expression of β-catenin and β-catenin mRNA in the ischemic brain tissue. These findings indicate that bFGF promotion of neural stem cell proliferation may be mediated by Wnt/β-catenin signaling pathway.     

环氧化酶-2抑制剂塞来昔布对C6胶质瘤细胞增殖和凋亡的影响

目的探讨选择性环氧化酶-2抑制剂塞来昔布对体外培养的C6胶质瘤细胞增殖和凋亡的影响。方法以不同浓度塞来昔布分别作用于C6胶质瘤细胞不同时间段,采用甲基噻唑蓝比色法检测细胞活性,流式细胞仪检测细胞周期和细胞凋亡,并用光镜及透射电镜观察细胞形态学和超微结构的变化。结果经不同浓度塞来昔布作用后,C6胶质瘤细胞活性受到抑制,且呈剂量时间依赖性,实验组与对照组之间以及实验组各亚组之间均有显著性差异（P〈0.05）。细胞周期检测发现实验组S期细胞减少,G2期细胞显著增加,与对照组比较有显著性差异（P〈0.05）;同时,塞来昔布还可诱导C6胶质瘤细胞凋亡,凋亡率在实验组与对照组之间有显著性差异（P〈0.05）。结论选择性环氧化酶-2抑制剂塞来昔布可抑制C6胶质瘤细胞增殖,诱导C6胶质瘤细胞凋亡。     

全反式维甲酸对胶质瘤干细胞VEGF和bFGF表达的影响

目的 研究全反式维甲酸(ATRA)对胶质瘤干细胞(GSCs)血管内皮细胞生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)表达的影响. 方法 从人胶质母细胞瘤细胞系U87中分离培养GSCs,免疫荧光染色检测CD133、巢蛋白(nestin)的表达进行鉴定.将取GSCs分成3组分别培养:(1)ATRA组:培养基中含10 nmol/L ATRA;(2)空载体组:培养基中含与ATRA组等量的二甲基亚砜(DMSO);(3)对照组:单纯培养基,培养10 d后免疫荧光染色检测胶质纤维酸性蛋白(GFAP)、β-微管蛋白Ⅲ(β-tubulinⅢ)、半乳糖脑苷脂(GalC)的表达;CCK8法检测各组细胞的增殖;ELISA和RT-PCR分别检测各组GSCs VEGF、bFGF的分泌水平和mRNA的表达. 结果 二代细胞球表达神经干细胞(NSCs)的标记抗体CD133和nestin.免疫荧光染色检测显示分化后GSCs能够分化为多种同源子代细胞(分别表达星形胶质细胞、神经元、少突胶质细胞标志物GFAP、β-tubulinⅢ、Galc);培养10d后ATRA组细胞GFAP的阳性表达率高于对照组及空载体组,差异有统计学意义(P＜0.05).第3.～7天ATRA组细胞增殖速度较对照组和空载体组明显变缓,差异有统计学意义(P＜0.05);分化24 h后ATRA组GSCs VEGF、bFGF的分泌水平和mRNA的表达均少于对照组和空载体组,差异有统计学意义(P＜0.05). 结论 ATRA能诱导GSCs分化并抑制其增殖,其可能通过抑制VEGF和bFGF的表达发挥抗胶质母细胞瘤的作用.     

Dexamethasone enhances serum deprivation-induced necrotic death of rat C6 glioma cells through activation of glucocorticoid receptors

Glucocorticoids have been shown to be neurotoxic and appear to play a role in neuronal cell loss during aging and following neuropathological insults. However, very little is known about the effects of these steroid hormones on glial cells. The effect of the synthetic glucocorticoid dexamethasone (DEX) on glial cell viability was therefore examined by measuring neutral red uptake into rat C6 glioma cells. Serum deprivation markedly reduced cell viability, and this effect was significantly enhanced by DEX. Electrophoretic analysis showed that the cell damage induced by either serum deprivation alone or in combination with DEX was not accompanied by the degradation of DNA into nucleosomic fragments. Electron microscopic studies confirmed that serum deprivation and glucocorticoid treatment caused necrotic cell death. Furthermore, the effect of DEX on cell viability could be mimicked by the glucocorticoid receptor agonist RU28362, and completely prevented by the glucocorticoid receptor antagonist RU38486. These results indicate that dexamethasone can enhance the necrotic death of glioma cells induced by serum deprivation, suggesting that glucocorticoids may be involved in the chronic alteration of brain function arising from neuropathological damage to glial cells.     

Antisense epidermal growth factor receptor RNA transfection in human malignant glioma cells leads to inhibition of proliferation and induction of differentiation

The epidermal growth factor receptor (EGFR) is a proto-oncogene that is frequently observed with alterations in late stage gliomas, suggesting an important role of this gene in glial tumorigenesis and progression. In this study we evaluated an antisense EGFR approach as an alternative therapeutic modality for glioblastomas. We transfected U-87MG cells with an antisense EGFR construct and obtained several clones stably expressing lower or undetectable levels of EGFR protein. These clones were found to have impaired proliferation as well as a reduced transforming potential to grow in soft agarose. The number of cells positive for the cell cycle-specific nuclear antigen Ki-67 was also significantly decreased ( P <0.05) in antisense EGFR-transfected clones compared with parental or empty vector-transfected cells. Flow cytometric analysis revealed that the proportion of cells in G₀ /G₁ phases of the cell cycle in the antisense clones increased by up to 31% compared with control cells, whereas the proportion of cells in S phase decreased by up to 58%. In addition, the antisense EGFR-transfected cells showed higher expression of glial fibrillary acidic protein and a more differentiated form, with smaller cell bodies possessing fine tapering cell processes. These results suggest that EGFR plays a major role in modulating cell growth and differentiation in glioblastoma cells. Our experimental model of antisense EGFR provides a basis for future development of antisense EGFR oligodeoxynucleotides in treatment of glioblastomas.     

外源性bFGF抑制辐射诱导的C17.2神经干细胞凋亡的实验研究

目的 观察外源性碱性成纤维细胞生长因子(bFGF)对辐射诱导的C17.2神经干细胞(NSCs)凋亡的影响,探讨细胞外信号调节激酶1/2(ERK1/2)在bFGF对辐射诱导的C17.2 NSCs凋亡的抑制效应中的作用. 方法 以直线加速器照射C17.2NSCs建立离体放射性损伤模型.MTT法检测细胞活性,流式细胞仪检测不同浓度的外源性bFGF和U0126对细胞凋亡的影响. 结果 外源性bFGF浓度为0～100ng/mL时,细胞凋亡率可由(12.78±1.04)%降低至(4.83±0.31)%,组间比较差异有统计学意义(P<0.05);加入U0126后细胞凋亡率为(8.42±0.71)%.DMSO对照组为(4.71±0.42)%,差异有统计学意义(P<0.05). 结论 外源性bFGF对辐射引起的C17.2 NSCs凋亡具有抑制作用,ERK1/2参与该效应.     

Differential roles of fibroblast growth factor-2 during development and maintenance of auditory sensory epithelia

Fibroblast growth factor-2 (FGF2) has been postulated to be a key regulator involved in the proliferation, differentiation, and regeneration of sensory hair cells. Here we have addressed the potential functions of FGF2 during the formation and regeneration of the auditory epithelium in chicken and mice. By using viral gene transfer, based on herpes simplex type 1 virus (HSV-1), we show that ectopically applied FGF2 drastically increases the number of cells expressing early hair cell markers during embryonic development in avians. Intriguingly, FGF2 does not stimulate cell division during this process. These data suggest that FGF2 plays a role during differentiation of sensory hair cells in avians. To address the potential functions of FGF2 during murine inner ear development, we analyzed FGF2 mouse mutants. Mice lacking FGF2 showed normal formation of the inner ear, and no abnormalities were observed at the adult stage. Moreover, FGF2 mouse mutants showed similar hearing thresholds compared with those observed in control mice before and after noise damage. Therefore, endogenous FGF2 appears not to be essential for the development or functional maintenance of the auditory organ in mammals. In light of these results, the differential roles of FGF2 in the vertebrate inner ear are discussed with respect to its previously postulated functions.     

碱性成纤维细胞生长因子对大鼠脑出血血肿周围脑组织和血浆中血栓素B2和6-酮-前列腺素F1a含量的影响

目的观察大鼠脑出血后应用碱性纤维细胞因子(bFGF)对血肿周围脑组织及血浆中TXB2和6-K-PGF1a含量及比值的影响。方法采用脑内注射胶原酶建立大鼠脑出血模型,分为脑出血模型对照组和bFGF治疗组,并于脑内注射生理盐水建立假手术组对照组。每组又分为1d和3d两个时间点,bFGF治疗组应用bFGF进行治疗,检测1d和3d后血肿周围脑组织及血浆中TXB2和6-K-PGF1a含量。结果bFGF治疗组与模型对照组比较,1d时血浆中TXB2含量降低(P<0.05),1d和3d时6-K-PGF1a含量则均升高(P<0.05),TXB2/6-K-PGF1a比值1d(P<0.05)和3d(P<0.01)时均降低;bFGF治疗组与模型对照组比较,血肿周围脑组织中TXB2含量3d时较脑出血模型组升高(P<0.01),6-K-PGF1a含量无显著差异(P>0.05),TXB2/6-K-PGF1a比值1d时降低(P<0.05),3d时升高(P<0.05)。结论脑出血后血浆中TXB2和6-K-PGF1a含量的变化比血肿周围脑组织中明显;bFGF可使大鼠脑出血后血浆中TXB2含量减少,6-K-PGF1a含量增多,TXB2/6-K-PGF1a比值降低。