We previously found that argon exerts its neuroprotective effect in part by inhibition of the toll-like receptors(TLR)2 and 4.The downstream transcription factors signal transducer and activator of transcription 3(STA...We previously found that argon exerts its neuroprotective effect in part by inhibition of the toll-like receptors(TLR)2 and 4.The downstream transcription factors signal transducer and activator of transcription 3(STAT3)and nuclear factor kappa B(NF-κB)are also affected by argon and may play a role in neuroprotection.It also has been demonstrated that argon treatment could mitigate brain damage,reduce excessive microglial activation,and subsequently attenuate brain inflammation.Despite intensive research,the further exact mechanism remains unclear.In this study,human neuroblastoma cells were damaged in vitro with rotenone over a period of 4 hours(to mimic cerebral ischemia and reperfusion damage),followed by a 2-hour post-conditioning with argon(75%).In a separate in vivo experiment,retinal ischemia/reperfusion injury was induced in rats by increasing intraocular pressure for 1 hour.Upon reperfusion,argon was administered by inhalation for 2 hours.Argon reduced the binding of the transcription factors signal transducer and activator of transcription 3,nuclear factor kappa B,activator protein 1,and nuclear factor erythroid 2-related factor 2,which are involved in regulation of neuronal damage.Flow cytometry analysis showed that argon downregulated the Fas ligand.Some transcription factors were regulated by toll-like receptors;therefore,their effects could be eliminated,at least in part,by the TLR2 and TLR4 inhibitor oxidized phospholipid 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine(OxPAPC).Argon treatment reduced microglial activation after retinal ischemia/reperfusion injury.Subsequent quantitative polymerase chain reaction analysis revealed a reduction in the pro-inflammatory cytokines interleukin(IL-1α),IL-1β,IL-6,tumor necrosis factorα,and inducible nitric oxide synthase.Our results suggest that argon reduced the extent of inflammation in retinal neurons after ischemia/reperfusion injury by suppression of transcription factors crucial for microglial activation.Argon has no known side effects or narcotic properties;therefore,therapeutic use of this noble gas appears ideal for treatment of patients with neuronal damage in retinal ischemia/reperfusion injury.The animal experiments were approved by the Commission for Animal Care of the University of Freiburg(approval No.35-9185.81/G14-122)on October 19,2012.展开更多
The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this stu...The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this study,human neuroblastoma SH-SY5Y cells were treated with different concentrations of argon(25%,50%,and 74%;21%O_(2),5%CO_(2),balance nitrogen)at different time intervals before inflicting damage with rotenone(20μM,4 hours).Apoptosis was determined by flow cytometry after annexin V and propidium iodide staining.Surface expressions of Toll-like receptors 2 and 4 were also examined.Cells were also processed for analysis by western blot and qPCR to determine the expression of apoptotic and inflammatory proteins,such as extracellular-signal regulated kinase(ERK1/2),nuclear transcription factor-κB(NF-κB),protein kinase B(Akt),caspase-3,Bax,Bcl-2,interleukin-8,and heat shock proteins.Immunohistochemical staining was performed for TLR2 and 4 and interleukin-8.Cells were also pretreated with OxPAPC,an antagonist of TLR2 and 4 to elucidate the molecular mechanism.Results showed that argon preconditioning before rotenone application caused a dose-dependent but not a time-dependent reduction in the number of apoptotic cells.Preconditioning with 74%argon for 2 hours was used for further experiments showing the most promising results.Argon decreased the surface expression of TLR2 and 4,whereas OxPAPC treatment partially abolished the protective effect of argon.Argon increased phosphorylation of ERK1/2 but decreased NF-κB and Akt.Preconditioning inhibited mitochondrial apoptosis and the heat shock response.Argon also suppressed the expression of the pro-inflammatory cytokine interleukin-8.Immunohistochemistry confirmed the alteration of TLRs and interleukin-8.OxPAPC reversed the argon effect on ERK1/2,Bax,Bcl-2,caspase-3,and interleukin-8 expression,but not on NF-κB and the heat shock proteins.Taken together,argon preconditioning protects against apoptosis of neuronal cells and mediates its action via Toll-like receptors.Argon may represent a promising therapeutic alternative in various clinical settings,such as the treatment of stroke.展开更多
AIM:To characterize the inductive effects of isoflurane(ISO) on hepatic heme oxygenase-1(HO-1) in an animal model of hepatic steatosis.METHODS:Lean(LEAN) and obese(FAT) Zucker rats were randomized into 4 groups:1:LEAN...AIM:To characterize the inductive effects of isoflurane(ISO) on hepatic heme oxygenase-1(HO-1) in an animal model of hepatic steatosis.METHODS:Lean(LEAN) and obese(FAT) Zucker rats were randomized into 4 groups:1:LEAN + pentobarbital sodium(PEN);2:LEAN + ISO;3:FAT + PEN;4:FAT + ISO.The animals were mechanically ventilated for 6 h.In vitro analyses of liver tissue included determination of HO-1 mRNA and protein expression as well as measurement of HO enzyme activity and immunohistochemical analyses.RESULTS:Compared to PEN treatment,ISO administration profoundly induced hepatic HO-1 mRNA and protein expression and significantly increased HO enzyme activity in lean Zucker rats.In contrast,no difference in HO-1 gene expression was observed after ISO or PEN anesthesia in obese Zucker rats.CONCLUSION:The present study demonstrates that ISO is an inducer of hepatic HO-1 gene expression in non-steatotic organs but failed to upregulate HO-1 in steatotic livers.展开更多
Neuronal injury and neuroprotection：Ischemia and reperfusion injuries in neuronal cells such as acute ischemic stroke-represent the third leading cause of death in the world.Current therapeutic concepts mainly aim to...Neuronal injury and neuroprotection：Ischemia and reperfusion injuries in neuronal cells such as acute ischemic stroke-represent the third leading cause of death in the world.Current therapeutic concepts mainly aim to re-establish cerebral blood flow within a time window of less than 3 hours with the goal of limiting secondary brain injury.展开更多
基金This work was financially supported by the Department of Anesthesiology and Critical Care,Medical Center-University of Freiburg,GermanyThe article processing charge was funded by the Baden-Württemberg Ministry of Science,Research and Art and the University of Freiburg in the funding programme Open Access Publishing.
文摘We previously found that argon exerts its neuroprotective effect in part by inhibition of the toll-like receptors(TLR)2 and 4.The downstream transcription factors signal transducer and activator of transcription 3(STAT3)and nuclear factor kappa B(NF-κB)are also affected by argon and may play a role in neuroprotection.It also has been demonstrated that argon treatment could mitigate brain damage,reduce excessive microglial activation,and subsequently attenuate brain inflammation.Despite intensive research,the further exact mechanism remains unclear.In this study,human neuroblastoma cells were damaged in vitro with rotenone over a period of 4 hours(to mimic cerebral ischemia and reperfusion damage),followed by a 2-hour post-conditioning with argon(75%).In a separate in vivo experiment,retinal ischemia/reperfusion injury was induced in rats by increasing intraocular pressure for 1 hour.Upon reperfusion,argon was administered by inhalation for 2 hours.Argon reduced the binding of the transcription factors signal transducer and activator of transcription 3,nuclear factor kappa B,activator protein 1,and nuclear factor erythroid 2-related factor 2,which are involved in regulation of neuronal damage.Flow cytometry analysis showed that argon downregulated the Fas ligand.Some transcription factors were regulated by toll-like receptors;therefore,their effects could be eliminated,at least in part,by the TLR2 and TLR4 inhibitor oxidized phospholipid 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine(OxPAPC).Argon treatment reduced microglial activation after retinal ischemia/reperfusion injury.Subsequent quantitative polymerase chain reaction analysis revealed a reduction in the pro-inflammatory cytokines interleukin(IL-1α),IL-1β,IL-6,tumor necrosis factorα,and inducible nitric oxide synthase.Our results suggest that argon reduced the extent of inflammation in retinal neurons after ischemia/reperfusion injury by suppression of transcription factors crucial for microglial activation.Argon has no known side effects or narcotic properties;therefore,therapeutic use of this noble gas appears ideal for treatment of patients with neuronal damage in retinal ischemia/reperfusion injury.The animal experiments were approved by the Commission for Animal Care of the University of Freiburg(approval No.35-9185.81/G14-122)on October 19,2012.
基金supported by the Department of Anesthesiology and Critical Care,Medical Center-University of Freiburg,Germanyfunded by the Baden-Wuerttemberg Ministry of Science,Research and Art and the University of Freiburg in the funding program Open Access Publishing
文摘The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this study,human neuroblastoma SH-SY5Y cells were treated with different concentrations of argon(25%,50%,and 74%;21%O_(2),5%CO_(2),balance nitrogen)at different time intervals before inflicting damage with rotenone(20μM,4 hours).Apoptosis was determined by flow cytometry after annexin V and propidium iodide staining.Surface expressions of Toll-like receptors 2 and 4 were also examined.Cells were also processed for analysis by western blot and qPCR to determine the expression of apoptotic and inflammatory proteins,such as extracellular-signal regulated kinase(ERK1/2),nuclear transcription factor-κB(NF-κB),protein kinase B(Akt),caspase-3,Bax,Bcl-2,interleukin-8,and heat shock proteins.Immunohistochemical staining was performed for TLR2 and 4 and interleukin-8.Cells were also pretreated with OxPAPC,an antagonist of TLR2 and 4 to elucidate the molecular mechanism.Results showed that argon preconditioning before rotenone application caused a dose-dependent but not a time-dependent reduction in the number of apoptotic cells.Preconditioning with 74%argon for 2 hours was used for further experiments showing the most promising results.Argon decreased the surface expression of TLR2 and 4,whereas OxPAPC treatment partially abolished the protective effect of argon.Argon increased phosphorylation of ERK1/2 but decreased NF-κB and Akt.Preconditioning inhibited mitochondrial apoptosis and the heat shock response.Argon also suppressed the expression of the pro-inflammatory cytokine interleukin-8.Immunohistochemistry confirmed the alteration of TLRs and interleukin-8.OxPAPC reversed the argon effect on ERK1/2,Bax,Bcl-2,caspase-3,and interleukin-8 expression,but not on NF-κB and the heat shock proteins.Taken together,argon preconditioning protects against apoptosis of neuronal cells and mediates its action via Toll-like receptors.Argon may represent a promising therapeutic alternative in various clinical settings,such as the treatment of stroke.
文摘AIM:To characterize the inductive effects of isoflurane(ISO) on hepatic heme oxygenase-1(HO-1) in an animal model of hepatic steatosis.METHODS:Lean(LEAN) and obese(FAT) Zucker rats were randomized into 4 groups:1:LEAN + pentobarbital sodium(PEN);2:LEAN + ISO;3:FAT + PEN;4:FAT + ISO.The animals were mechanically ventilated for 6 h.In vitro analyses of liver tissue included determination of HO-1 mRNA and protein expression as well as measurement of HO enzyme activity and immunohistochemical analyses.RESULTS:Compared to PEN treatment,ISO administration profoundly induced hepatic HO-1 mRNA and protein expression and significantly increased HO enzyme activity in lean Zucker rats.In contrast,no difference in HO-1 gene expression was observed after ISO or PEN anesthesia in obese Zucker rats.CONCLUSION:The present study demonstrates that ISO is an inducer of hepatic HO-1 gene expression in non-steatotic organs but failed to upregulate HO-1 in steatotic livers.
文摘Neuronal injury and neuroprotection：Ischemia and reperfusion injuries in neuronal cells such as acute ischemic stroke-represent the third leading cause of death in the world.Current therapeutic concepts mainly aim to re-establish cerebral blood flow within a time window of less than 3 hours with the goal of limiting secondary brain injury.
