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
To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein express...To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.展开更多
Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is...Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs. Methods： Real-time reverse transcription polymerase chain reaction （RT-PCR） was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells （HUVEC） were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α （TN F-α） treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TN F-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Results： The expression ofmiR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression ofmiR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3＇ untranslated region site, Conclusion： MiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.展开更多
背景与目的:张力蛋白同源第10号染色体缺失的磷酸酶基因(phosphatase and tensin homolog deleted on chromosome 10,PTEN)缺失是西方国家前列腺癌中最常见的基因异常之一,与肿瘤的进展、预后均有一定相关性。鉴于前列腺癌的异质性,不...背景与目的:张力蛋白同源第10号染色体缺失的磷酸酶基因(phosphatase and tensin homolog deleted on chromosome 10,PTEN)缺失是西方国家前列腺癌中最常见的基因异常之一,与肿瘤的进展、预后均有一定相关性。鉴于前列腺癌的异质性,不同地区、人群间其基因表达谱存在广泛差异,本研究主要探讨PTEN蛋白缺失在中国前列腺癌患者中的发生率以及与生化复发的相关性。方法:选取2006—2011年225例局限性前列腺癌并采取根治切除术的患者为研究对象,回顾性收集所有患者的临床病理资料,包括确诊时年龄、血清前列腺特异性抗原(prostate-specific antigen,PSA)值、Gleason分级评分、TNM分期、手术切缘和术后生化复发与否及时间。将225例局限性前列腺癌根治切除标本的肿瘤组织及癌旁组织制成组织芯片(tissue microarray,TMA),采用免疫组织化学技术检测PTEN蛋白在肿瘤及癌旁组织中的表达。采用χ2检验分析前列腺癌组织中PTEN蛋白缺失与患者临床病理特征的相关性。运用Kaplan-Meier生存分析模型、Cox比例风险模型分析PTEN蛋白缺失及患者临床病理特征与生化复发的关系。结果:前列腺癌患者中PTEN蛋白缺失率为15%(33/217),且存在PTEN蛋白缺失的前列腺癌患者其确诊时血清PSA值(P=0.030)及年龄(P=0.009)要显著高于PTEN表达的前列腺癌患者。单因素生存分析显示,PTEN表达情况(P=0.013 1)、确诊时血清PSA值(P=0.000 4)和Gleason分级评分(P=0.019 8)与前列腺癌患者的生化复发相关。Cox多因素分析结果表明,PTEN蛋白表达情况(HR=0.536,P=0.044)、确诊时血清PSA值(HR=1.879,P=0.001)和Gleason分级评分(HR=1.361,P=0.030)为前列腺癌患者生化复发的独立预后因素。结论:PTEN蛋白表达情况是局限性前列腺癌患者根治术后生化复发的独立预后因素,检测PTEN蛋白有望改善根治术后前列腺癌患者的管理及指导进一步治疗。展开更多
目的:研究第10号染色体缺失的磷酸酶张力蛋白同源物基因(phosphatase and tensin homologue deleted on chromosome ten,PTEN)/磷脂酰肌醇3-激酶(phosphoinositide 3-kinase,PI3K)在肝缺血再灌注损伤中的调控作用及可能的机制.方法:夹闭...目的:研究第10号染色体缺失的磷酸酶张力蛋白同源物基因(phosphatase and tensin homologue deleted on chromosome ten,PTEN)/磷脂酰肌醇3-激酶(phosphoinositide 3-kinase,PI3K)在肝缺血再灌注损伤中的调控作用及可能的机制.方法:夹闭C57BL/6J小鼠的肝动脉和门静脉以阻断肝脏向头侧肝叶血供90 min,随后取下血管夹恢复血供,建立肝缺血再灌注损伤模型.实验分为四组:正常对照组(sham)、缺血再灌注模型组(IR)、PTEN抑制剂bpv(HOpic)干预组(BPV+IR)、PI3K抑制剂wortmannin干预组(WM+IR).检测小鼠血清ALT水平,行肝组织病理检查,以评估抑制PTEN/PI3K对肝脏IRI的影响.采用Western blot法检测p-AKT、p-GSK3β的表达,分析抑制PTEN/PI3K对其下游关键效应分子AKT/GSK3β磷酸化的调控.采用定量PCR法检测炎性因子IL-12p40、IL-10及TNF-α的基因表达,分析抑制PTEN/PI3K对TLR4介导的炎症反应的影响.结果:血清ALT及肝组织学改变均提示,抑制PTEN使IR诱导的肝损害明显减轻,相反,抑制PI3K则使IRI加剧.随着再灌注的发生,缺血期去磷酸化的AKT/GSK3β逐渐恢复其磷酸化活性.抑制PTEN增强了再灌注触发的AKT/GSK3β磷酸化,而阻断PI3K则使其明显削弱.阻断PTEN抑制了促炎基因IL-12p40、TNF-α的表达,并使IL-12/IL-10比值下调,该结果与抑制PI3K产生的效应完全相反.结论:PTEN/PI3K在肝缺血再灌注损伤中发挥重要的调控作用,PTEN抑制和/或PI3K活化可能通过上调p-AKT/p-GSK3β以及抑制炎症反应明显减轻肝缺血再灌注损伤.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.
文摘To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.
基金This research was funded by the National Natural Science Foundation of China (NSFC)
文摘Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs. Methods： Real-time reverse transcription polymerase chain reaction （RT-PCR） was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells （HUVEC） were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α （TN F-α） treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TN F-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Results： The expression ofmiR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression ofmiR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3＇ untranslated region site, Conclusion： MiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.
