AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions...AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-alpha, IL-6, and IL-1, which may play a very important role in inducing the growth hormone insensitivity. The objective of this current study was to investigate the role of endotoxin, TNF-alpha and IL-6 in inducing the growth hormone insensitivity at the receptor and post-receptor levels. METHODS: Spague-Dawley rats were injected with endotoxin, TNF-alpha, and IL-6, respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously. All rats were killed at different time points. The expression of IGF-I, GHR, SOCS-3 and beta-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection, however, liver IGF-I mRNA expression had been obviously down-regulated in endotoxemic rats. Liver GHR mRNA expression also had a predominant down-regulation after endotoxin injection. The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection, being decreased by 53% compared with control rats. For GHR mRNA expression, the lowest expression occurred at 8h and had a 81% decrease. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats. Exogenous GH could enhance IGF-I mRNA expression in control rats, but it did fail to prevent the decline in IGF-I mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression. The liver GHR mRNA expression was obviously down-regulated after TNF-alpha iv injection and had a 40% decrease at 8h, but the liver SOCS-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection. CONCLUSION: The growth hormone insensitivity could be induced by LPS injection, which was associated with down-regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level. The in vivo biological activities of LPS were mediated by TNF-alpha and IL-6 indirectly, and TNF-alpha and IL-6 may exert their effects on the receptor and post-receptor levels respectively.展开更多
Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central ...Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair.Ginkgolide B has a robust neuroprotective effect.In this study,we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo.Neural stem cells were treated with 20,40 and 60 mg/L ginkgolide B in vitro.Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase,glial fibrillary acid protein and suppressor of cytokine signaling 2.After treatment with 40 and 60 mg/L ginkgolide B,cells were large,with long processes.Moreover,the proportions of neuron-specific enolase-,glial fibrillary acid protein-and suppressor of cytokine signaling 2-positive cells increased.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.Six hours after ischemia,ginkgolide B（20 mg/kg） was intraperitoneally injected,once a day.Zea Longa＇s method was used to assess neurological function.Immunohistochemistry was performed to evaluate the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells.Real-time quantitative polymerase chain reaction was used to measure m RNA expression of brain-derived neurotrophic factor and epidermal growth factor.Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2.Ginkgolide B decreased the neurological deficit score,increased the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells,increased the m RNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra.Together,the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury.展开更多
BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(AL...BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(ALF) in D-galactosamine(GalN)sensitized mice.The aim of this study was to identify the role of Ron in the regulation of hepatic gene expression.METHODS:Microarray analyses were performed on liver RNA isolated sequentially from wild-type(WT) and TK-/mice during the progression of ALF.Gene array data were validated using Western and immunohistochemistry analyses as well as with ex vivo culture systems.RESULTS:At baseline,101 genes were differentially expressed between WT and TK-/-livers,which regulate processes involved in hypoxia,proliferation,apoptosis and metabolism.One hour after ALF induction,WT livers exhibited increased cytokine expression compared to TK-/-livers,and after 4 hours,an induction of suppressor of cytokine signaling(SOCS) genes as well as JAK-STAT pathway activation were prominent in TK-/livers compared to controls.CONCLUSION:Our studies suggest a novel hepato-protective mechanism in Ron TK-/-mice wherein increased and sustained SOCS production and JAK-STAT activation in the hepatocyte may inhibit the destructive proinflammatory milieu and promote survival factors which blunt hepatic death and the ensuing development of ALF.展开更多
目的在人胰腺癌细胞中观察细胞因子信号转导抑制因子1(SOCS1)沉默对细胞增殖及干扰素-γ(IFN-γ)敏感性的影响,探讨SOCS1作为胰腺癌治疗靶点的可能。方法 Western blot及PCR验证SOCS1干扰序列沉默人胰腺癌细胞系PANC1中SOCS1的表达;给予...目的在人胰腺癌细胞中观察细胞因子信号转导抑制因子1(SOCS1)沉默对细胞增殖及干扰素-γ(IFN-γ)敏感性的影响,探讨SOCS1作为胰腺癌治疗靶点的可能。方法 Western blot及PCR验证SOCS1干扰序列沉默人胰腺癌细胞系PANC1中SOCS1的表达;给予IFN-γ刺激后,采用Western blotting方法观察转录激活因子(STAT)1及磷酸化STAT(pSTAT)1的变化;采用定量PCR的方法观察IFN-γ调节因子1(IRF-1)表达水平变化;MTT法检测胰腺癌细胞对IFN-γ敏感性的变化;细胞计数的方法观察细胞的增殖速度;采用流式细胞术的方法检测细胞周期的变化。结果将SOCS1干扰序列转染PANC1细胞后,SOCS1 mRNA及蛋白表达水平均明显下降。沉默SOCS1表达后,pshSOCS1-PANC1组细胞的IRF-1 mRNA水平及pSTAT1蛋白表达水平均显著升高(P<0.05),IFN-γ对PANC1细胞的半数抑制浓度(IC50)显著降低(P<0.01);转染72 h后PANC1细胞数量较对照组显著减少(P<0.05);SOCS1表达抑制后PANC1细胞G0/G1期细胞比例明显升高,而S期和G2/M期细胞比例明显减小,与对照组比较差异均有统计学意义。结论 SOCS1表达抑制后,人胰腺癌细胞株PANC1的增殖能力下降,并且对IFN-γ的敏感性增强。展开更多
基金the key,project of the tenth-five foundation of PLA,No.01Z011
文摘AIM: Critical illnesses such as sepsis, trauma, and burns cause a growth hormone insensitivity, which leads to an increased negative nitrogen balance. Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-alpha, IL-6, and IL-1, which may play a very important role in inducing the growth hormone insensitivity. The objective of this current study was to investigate the role of endotoxin, TNF-alpha and IL-6 in inducing the growth hormone insensitivity at the receptor and post-receptor levels. METHODS: Spague-Dawley rats were injected with endotoxin, TNF-alpha, and IL-6, respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously. All rats were killed at different time points. The expression of IGF-I, GHR, SOCS-3 and beta-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection, however, liver IGF-I mRNA expression had been obviously down-regulated in endotoxemic rats. Liver GHR mRNA expression also had a predominant down-regulation after endotoxin injection. The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection, being decreased by 53% compared with control rats. For GHR mRNA expression, the lowest expression occurred at 8h and had a 81% decrease. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats. Exogenous GH could enhance IGF-I mRNA expression in control rats, but it did fail to prevent the decline in IGF-I mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression. The liver GHR mRNA expression was obviously down-regulated after TNF-alpha iv injection and had a 40% decrease at 8h, but the liver SOCS-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection. CONCLUSION: The growth hormone insensitivity could be induced by LPS injection, which was associated with down-regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level. The in vivo biological activities of LPS were mediated by TNF-alpha and IL-6 indirectly, and TNF-alpha and IL-6 may exert their effects on the receptor and post-receptor levels respectively.
基金supported by the National Natural Science Foundation of China,No.81073082 to JSZ
文摘Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair.Ginkgolide B has a robust neuroprotective effect.In this study,we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo.Neural stem cells were treated with 20,40 and 60 mg/L ginkgolide B in vitro.Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase,glial fibrillary acid protein and suppressor of cytokine signaling 2.After treatment with 40 and 60 mg/L ginkgolide B,cells were large,with long processes.Moreover,the proportions of neuron-specific enolase-,glial fibrillary acid protein-and suppressor of cytokine signaling 2-positive cells increased.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.Six hours after ischemia,ginkgolide B（20 mg/kg） was intraperitoneally injected,once a day.Zea Longa＇s method was used to assess neurological function.Immunohistochemistry was performed to evaluate the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells.Real-time quantitative polymerase chain reaction was used to measure m RNA expression of brain-derived neurotrophic factor and epidermal growth factor.Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2.Ginkgolide B decreased the neurological deficit score,increased the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells,increased the m RNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra.Together,the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury.
基金supported by grants from the Public Health Services DK-73552 (WSE)the Digestive Diseases Research Development Center DK-064403 (WSE and LMA)from the National Institutes of Healthby grant project #8950(WSE) from Shriner's Hospital for Children
文摘BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(ALF) in D-galactosamine(GalN)sensitized mice.The aim of this study was to identify the role of Ron in the regulation of hepatic gene expression.METHODS:Microarray analyses were performed on liver RNA isolated sequentially from wild-type(WT) and TK-/mice during the progression of ALF.Gene array data were validated using Western and immunohistochemistry analyses as well as with ex vivo culture systems.RESULTS:At baseline,101 genes were differentially expressed between WT and TK-/-livers,which regulate processes involved in hypoxia,proliferation,apoptosis and metabolism.One hour after ALF induction,WT livers exhibited increased cytokine expression compared to TK-/-livers,and after 4 hours,an induction of suppressor of cytokine signaling(SOCS) genes as well as JAK-STAT pathway activation were prominent in TK-/livers compared to controls.CONCLUSION:Our studies suggest a novel hepato-protective mechanism in Ron TK-/-mice wherein increased and sustained SOCS production and JAK-STAT activation in the hepatocyte may inhibit the destructive proinflammatory milieu and promote survival factors which blunt hepatic death and the ensuing development of ALF.
