BACKGROUND： Nerve growth factor （NGF） attenuates glutamate-induced injury to hippocampal neurons, and the human tumor suppressor gene phosphatase and tensin homologue deleted on chromosome 10 （PTEN） promotes neur...BACKGROUND： Nerve growth factor （NGF） attenuates glutamate-induced injury to hippocampal neurons, and the human tumor suppressor gene phosphatase and tensin homologue deleted on chromosome 10 （PTEN） promotes neuronal apoptosis. However, effects of PTEN in NGF-mediated neuroprotection against glutamate excitotoxicity remain poorly understood. OBJECTIVE： To investigate the relationship between NGF inhibition of glutamate-induced injury and PTEN. DESIGN, TIME AND SE＇I＇rlNG： The randomized, controlled, in vitro study was performed at the Department of Pathophysiology, Medical School of Nantong University, China from October 2007 to March 2008. MATERIALS： Glutamate, NGF, 4, 6-diamidino-2-phenyl-indolediacetate, 3-[4, 5-dimethylthiazol-2-yl]- 2, 5-diphenyl tetrazoliumbromide （M-I-F）, and lactate dehydrogenase kit （Sigma, USA）, fluorescence microscope and inverted phase contrast microscope （Olympus, Japan） were used in this study. METHODS： Hippocampal neurons were obtained from newborn （〈 24 hours） Sprague Dawley rats and cultured for 7 days. The control group was not treated with any intervention factor, the glutamate group was treated with glutamate （0.2 mmol/L）, and NGF groups were treated with NGF （10, 50, 100, and 200 μg/L, respectively） prior to glutamate treatment. MAIN OUTCOME MEASURES： The MTT and lactate dehydrogenase assays were applied to evaluate viability of hippocampal neurons. Morphological changes in hippocampal neurons were observed using an inverted phase-contrast microscope, and neuronal apoptosis was detected by 4, 6-diamidino-2- phenyl-indolediacetate staining. PTEN mRNA and protein expression were measured by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. RESULTS： Glutamate （0.2 mmol/L） induced significantly decreased neuronal viability and greater lactate dehydrogenase efflux compared with the control group （P 〈 0.01）. However, compared with the glutamate group, cell viability significantly increased and lactate dehydrogenase efflux decreased in the NGF group with increasing NGF concentrations （P 〈 0.05 or P 〈 0.01）. The apoptotic ratio and PTEN mRNA and protein expression decreased in the NGF group compared with the glutamate group （P 〈 0.01）. CONCLUSION： Pretreatment with NGF exerted neuroprotective effects against glutamate-induced injury, partially through inhibition of PTEN expression and neuronal apoptosis.展开更多
This review updates the current views on aging gastric mucosa and the mechanisms of its increased susceptibility to injury. Experimental and clinical studies indicate that gastric mucosa of aging individuals-...This review updates the current views on aging gastric mucosa and the mechanisms of its increased susceptibility to injury. Experimental and clinical studies indicate that gastric mucosa of aging individuals-“aging gastropathy”-has prominent structural and functional abnormalities vs young gastric mucosa. Some of these abnormalities include a partial atrophy of gastric glands, impaired mucosal defense (reduced bicarbonate and prostaglandin generation, decreased sensory innervation), increased susceptibility to injury by a variety of damaging agents such as ethanol, aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), impaired healing of injury and reduced therapeutic efficacy of ulcer-healing drugs. Detailed analysis of the above changes indicates that the following events occur in aging gastric mucosa: reduced mucosal blood flow and impaired oxygen delivery cause hypoxia, which leads to activation of the early growth response-1 (egr-1) transcription factor. Activation of egr-1, in turn, upregulates the dual specificity phosphatase, phosphatase and tensin homologue deleted on chromosome ten (PTEN) resulting in activation of pro-apoptotic caspase-3 and caspase-9 and reduced expression of the anti-apoptosis protein, survivin. The imbalance between pro- and anti-apoptosis mediators results in increased apoptosis and increased susceptibility to injury. This paradigm has human relevance since increased expression of PTEN and reduced expression of survivin were demonstrated in gastric mucosa of aging individuals. Other potential mechanisms operating in aging gastric mucosa include reduced telomerase activity, increase in replicative cellular senescence, and reduced expression of vascular endothelial growth factor and importin-α-a nuclear transport protein essential for transport of transcription factors to nucleus. Aging gastropathy is an important and clinically relevant issue because of: (1) an aging world population due to prolonged life span; (2) older patients have much greater risk of gastroduodenal ulcers and gastrointestinal complications (e.g., NSAIDs-induced gastric injury) than younger patients; and (3) increased susceptibility of aging gastric mucosa to injury can be potentially reduced or reversed pharmacologically.展开更多
目的:研究携带第10号染色体缺失的磷酸脂酶和张力蛋白同源基因(phosphatase and tensin homologue-deleted chromosome ten gene,PTEN)的腺病毒表达载体对A549肺癌细胞体内外生长的抑制作用。方法:从人外周血淋巴细胞中通过RT-PCR扩增出...目的:研究携带第10号染色体缺失的磷酸脂酶和张力蛋白同源基因(phosphatase and tensin homologue-deleted chromosome ten gene,PTEN)的腺病毒表达载体对A549肺癌细胞体内外生长的抑制作用。方法:从人外周血淋巴细胞中通过RT-PCR扩增出PTEN基因片段,将其克隆到pAdTrack-CMV转移载体上,构建了PTEN重组腺病毒载体。体外用MTT法检测Ad-PTEN对A549肺癌细胞生长的抑制作用,以流式细胞术检测肿瘤细胞的周期和凋亡率。建立荷瘤裸鼠模型,体内检测Ad-PTEN对A549肺癌细胞移植瘤生长的影响,以免疫组化法检测移植瘤中微血管密度。结果:克隆的PTEN基因测序结果与基因Bank数据库完全相符。Ad-PTEN体外感染A549肺癌细胞48h后其凋亡率为10.5%,明显高于对照细胞;4d后细胞生长与对照组细胞相比抑制了57%。肺癌细胞移植瘤治疗结束时,Ad-PTEN组瘤重为(0.58±0·29)g,对照组瘤重为(1.42±0.24)g,其生长抑制达59%(P<0.05);同时移植瘤中微血管密度降低约49%(P<0.05)。结论:成功构建的Ad-PTEN腺病毒载体能在体内外抑制A549肺癌细胞及其移植瘤的生长。展开更多
目的探讨β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡及第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)/丝苏氨酸蛋白激酶(Akt)表达的影响。方法采用不同浓度β-咔啉类生物碱(0、10、20、40μg/ml)处理SGC-7901细胞后,应用活细...目的探讨β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡及第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)/丝苏氨酸蛋白激酶(Akt)表达的影响。方法采用不同浓度β-咔啉类生物碱(0、10、20、40μg/ml)处理SGC-7901细胞后,应用活细胞计数试剂盒(CCK-8)法检测β-咔啉类生物碱处理24、48 h后的SGC-7901细胞增殖抑制情况,Hoechst 33258染色、琼脂糖凝胶电泳法观察β-咔啉类生物碱处理48 h后的细胞凋亡情况,荧光定量聚合酶链反应和Western blotting分别检测β-咔啉类生物碱(0、10、20、30、40μg/ml)处理48 h后细胞中PTEN、Akt m RNA和蛋白水平。结果β-咔啉类生物碱均能抑制人胃癌SGC-7901细胞的增殖,抑制率呈浓度依赖性(P<0.05);β-咔啉类生物碱可诱导人胃癌SGC-7901细胞凋亡,且伴有凋亡特有的DNA梯形条带;与0μg/ml相比,其余浓度β-咔啉类生物碱处理48 h后的PTEN m RNA和蛋白表达增加,而Akt m RNA和蛋白表达减少,差异均有统计学意义(P<0.05)。结论β-咔啉类生物碱可抑制人胃癌SGC-7901细胞增殖并诱导凋亡,可能与影响PTEN及Akt表达有关。展开更多
基金the Natural Science Foundation of Jiangsu Province, No. BK2004048the Social Development and Technology Plan of Nantong City, No. K2008009
文摘BACKGROUND： Nerve growth factor （NGF） attenuates glutamate-induced injury to hippocampal neurons, and the human tumor suppressor gene phosphatase and tensin homologue deleted on chromosome 10 （PTEN） promotes neuronal apoptosis. However, effects of PTEN in NGF-mediated neuroprotection against glutamate excitotoxicity remain poorly understood. OBJECTIVE： To investigate the relationship between NGF inhibition of glutamate-induced injury and PTEN. DESIGN, TIME AND SE＇I＇rlNG： The randomized, controlled, in vitro study was performed at the Department of Pathophysiology, Medical School of Nantong University, China from October 2007 to March 2008. MATERIALS： Glutamate, NGF, 4, 6-diamidino-2-phenyl-indolediacetate, 3-[4, 5-dimethylthiazol-2-yl]- 2, 5-diphenyl tetrazoliumbromide （M-I-F）, and lactate dehydrogenase kit （Sigma, USA）, fluorescence microscope and inverted phase contrast microscope （Olympus, Japan） were used in this study. METHODS： Hippocampal neurons were obtained from newborn （〈 24 hours） Sprague Dawley rats and cultured for 7 days. The control group was not treated with any intervention factor, the glutamate group was treated with glutamate （0.2 mmol/L）, and NGF groups were treated with NGF （10, 50, 100, and 200 μg/L, respectively） prior to glutamate treatment. MAIN OUTCOME MEASURES： The MTT and lactate dehydrogenase assays were applied to evaluate viability of hippocampal neurons. Morphological changes in hippocampal neurons were observed using an inverted phase-contrast microscope, and neuronal apoptosis was detected by 4, 6-diamidino-2- phenyl-indolediacetate staining. PTEN mRNA and protein expression were measured by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. RESULTS： Glutamate （0.2 mmol/L） induced significantly decreased neuronal viability and greater lactate dehydrogenase efflux compared with the control group （P 〈 0.01）. However, compared with the glutamate group, cell viability significantly increased and lactate dehydrogenase efflux decreased in the NGF group with increasing NGF concentrations （P 〈 0.05 or P 〈 0.01）. The apoptotic ratio and PTEN mRNA and protein expression decreased in the NGF group compared with the glutamate group （P 〈 0.01）. CONCLUSION： Pretreatment with NGF exerted neuroprotective effects against glutamate-induced injury, partially through inhibition of PTEN expression and neuronal apoptosis.
基金Supported by VA Merit Review grant to Tarnawski AS
文摘This review updates the current views on aging gastric mucosa and the mechanisms of its increased susceptibility to injury. Experimental and clinical studies indicate that gastric mucosa of aging individuals-“aging gastropathy”-has prominent structural and functional abnormalities vs young gastric mucosa. Some of these abnormalities include a partial atrophy of gastric glands, impaired mucosal defense (reduced bicarbonate and prostaglandin generation, decreased sensory innervation), increased susceptibility to injury by a variety of damaging agents such as ethanol, aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), impaired healing of injury and reduced therapeutic efficacy of ulcer-healing drugs. Detailed analysis of the above changes indicates that the following events occur in aging gastric mucosa: reduced mucosal blood flow and impaired oxygen delivery cause hypoxia, which leads to activation of the early growth response-1 (egr-1) transcription factor. Activation of egr-1, in turn, upregulates the dual specificity phosphatase, phosphatase and tensin homologue deleted on chromosome ten (PTEN) resulting in activation of pro-apoptotic caspase-3 and caspase-9 and reduced expression of the anti-apoptosis protein, survivin. The imbalance between pro- and anti-apoptosis mediators results in increased apoptosis and increased susceptibility to injury. This paradigm has human relevance since increased expression of PTEN and reduced expression of survivin were demonstrated in gastric mucosa of aging individuals. Other potential mechanisms operating in aging gastric mucosa include reduced telomerase activity, increase in replicative cellular senescence, and reduced expression of vascular endothelial growth factor and importin-α-a nuclear transport protein essential for transport of transcription factors to nucleus. Aging gastropathy is an important and clinically relevant issue because of: (1) an aging world population due to prolonged life span; (2) older patients have much greater risk of gastroduodenal ulcers and gastrointestinal complications (e.g., NSAIDs-induced gastric injury) than younger patients; and (3) increased susceptibility of aging gastric mucosa to injury can be potentially reduced or reversed pharmacologically.
文摘目的:研究携带第10号染色体缺失的磷酸脂酶和张力蛋白同源基因(phosphatase and tensin homologue-deleted chromosome ten gene,PTEN)的腺病毒表达载体对A549肺癌细胞体内外生长的抑制作用。方法:从人外周血淋巴细胞中通过RT-PCR扩增出PTEN基因片段,将其克隆到pAdTrack-CMV转移载体上,构建了PTEN重组腺病毒载体。体外用MTT法检测Ad-PTEN对A549肺癌细胞生长的抑制作用,以流式细胞术检测肿瘤细胞的周期和凋亡率。建立荷瘤裸鼠模型,体内检测Ad-PTEN对A549肺癌细胞移植瘤生长的影响,以免疫组化法检测移植瘤中微血管密度。结果:克隆的PTEN基因测序结果与基因Bank数据库完全相符。Ad-PTEN体外感染A549肺癌细胞48h后其凋亡率为10.5%,明显高于对照细胞;4d后细胞生长与对照组细胞相比抑制了57%。肺癌细胞移植瘤治疗结束时,Ad-PTEN组瘤重为(0.58±0·29)g,对照组瘤重为(1.42±0.24)g,其生长抑制达59%(P<0.05);同时移植瘤中微血管密度降低约49%(P<0.05)。结论:成功构建的Ad-PTEN腺病毒载体能在体内外抑制A549肺癌细胞及其移植瘤的生长。
文摘目的探讨β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡及第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)/丝苏氨酸蛋白激酶(Akt)表达的影响。方法采用不同浓度β-咔啉类生物碱(0、10、20、40μg/ml)处理SGC-7901细胞后,应用活细胞计数试剂盒(CCK-8)法检测β-咔啉类生物碱处理24、48 h后的SGC-7901细胞增殖抑制情况,Hoechst 33258染色、琼脂糖凝胶电泳法观察β-咔啉类生物碱处理48 h后的细胞凋亡情况,荧光定量聚合酶链反应和Western blotting分别检测β-咔啉类生物碱(0、10、20、30、40μg/ml)处理48 h后细胞中PTEN、Akt m RNA和蛋白水平。结果β-咔啉类生物碱均能抑制人胃癌SGC-7901细胞的增殖,抑制率呈浓度依赖性(P<0.05);β-咔啉类生物碱可诱导人胃癌SGC-7901细胞凋亡,且伴有凋亡特有的DNA梯形条带;与0μg/ml相比,其余浓度β-咔啉类生物碱处理48 h后的PTEN m RNA和蛋白表达增加,而Akt m RNA和蛋白表达减少,差异均有统计学意义(P<0.05)。结论β-咔啉类生物碱可抑制人胃癌SGC-7901细胞增殖并诱导凋亡,可能与影响PTEN及Akt表达有关。
