Objective:To test the effects of salidroside on formation and growth of glioma together with tumor microenvironment.Methods:Salidroside extracted from Rhodiola rosea was purified and treated on human glioma cells U2...Objective:To test the effects of salidroside on formation and growth of glioma together with tumor microenvironment.Methods:Salidroside extracted from Rhodiola rosea was purified and treated on human glioma cells U251 at the concentration of 20 μg/mL.3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazolium bromide (MTT) assay for cytotoxicity and flow cytometry (FCM) for cell cycle analysis were performed.Then for in vivo study,xenotransplantation tumor model in nude mice was generated and treated with salidroside at the concentration of 50 mg/kg.d for totally 20 d.Body weight and tumor size were detected every 2 d after the treatment.The levels of 8-isoprostane,superoxide dismutase (SOD) and malondialdehyde (MDA),special markers for oxidative stress,were detected while immunofluoresence staining was performed for astrocyte detection.Results:For in vitro study,salidroside could decrease the viability of human glioma cells U251 and the growth of U251 cells at G0/G1 checkpoint during the cell cycle.For in vivo study,salidroside could also inhibit the growth of human glioma tissue in nude mice.The body weight of these nude mice treated with salidroside did not decrease as quickly as control group.In the tumor xenotransplantation nude mice model,mice were found of inhibition of oxidative stress by detection of biomarkers.Furthermore,overgrowth of astrocytes due to the stimulation of oxidative stress in the cortex of brain was inhibited after the treatment of salidroside.Conclusions:Salidroside could inhibit the formation and growth of glioma both in vivo and in vitro and improve the tumor microenvironment via inhibition of oxidative stress and astrocytes.展开更多
Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In t...Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.展开更多
Objective: To investigate the activation (phosphorylation) and subcellular localization of extracellular signal-regulated kinase (ERK1/2). as well as the possible mechanism, following cerebral ischemia and ischemia/re...Objective: To investigate the activation (phosphorylation) and subcellular localization of extracellular signal-regulated kinase (ERK1/2). as well as the possible mechanism, following cerebral ischemia and ischemia/reperfusion in rat hippocampus. Methods: Transient brain ischemia was induced by the four-vessel occlusion method in Sprague-Dawley rats. Western blot analysis. Results: During cerebral ischemia without reperfusion ERK1/2 activation immediately increased with a peak at 5 min and then decreased in the cytosol fraction, which was paralleled by the increase of ERK1/2 activation in the nucleus fraction. During reperfusion, ERK1/2 was activated with peaks occurring at 10 min in the cytosol and at 30 min in the nucleus, respectively. Under those conditions, the protein expressions had no significant change. In order to clarify the possible mechanism of ERKl/2 activation, the rats were intraperitoneally administrated with N-methyl-D-aspartate (NMDA) receptor antagonist dextromethorphan(DM), L-type voltage-gated Ca2+ channel (L-VGCC) antagonist nifedipine (ND) 20 min before ischemia, finding that DM and ND markedly prevented ERKl/2 activation of nucleus fraction induced by reperfusion. not by ischemia. Conclusion: These results suggested that the nuclear translocation mainly occurred during ischemia, while ischemia-reperfusion induced ERK1/2 activation both in the cytosol and the nucleus. Two type calcium channels contributed, at least partially, to the activation of ERK1/2.展开更多
Polysaccharides of Momordica charantia have been reported to be the primary bioactive components that confer its antioxidant activity. To some degree, antioxidants may provide beneficial effects on neuronal damage ind...Polysaccharides of Momordica charantia have been reported to be the primary bioactive components that confer its antioxidant activity. To some degree, antioxidants may provide beneficial effects on neuronal damage induced by seizures. However, the protective effects of Momordica charantia polysaccharides (MCPs) on seizures remain unclear. In this study, our purpose was to investigate the effects of MCPs on oxidative stress and neurodegeneration in an experimental Kainic acid (KA)-induced rat seizure model. MCPs treatments decreased the level of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD) and catalase (CAT) in the hippocampus of the KA-induced animal model. Moreover, MCPs significantly attenuated KA-induced neuronal loss in the CA1 and CA3 hippocampal regions. Based on these results, MCPs exert neuroprotective effects by attenuating KA-induced neuronal damage in the brain through their free radical scavenging activities.展开更多
Objective: To study the effects of chronic lithium on N-methyl-d-aspartate receptor subunit 2B (NR2B) tyrosine phosphorylation and the interactions of NR2B and PSD-95 with Src induced by cerebral ischemia/reperfusi...Objective: To study the effects of chronic lithium on N-methyl-d-aspartate receptor subunit 2B (NR2B) tyrosine phosphorylation and the interactions of NR2B and PSD-95 with Src induced by cerebral ischemia/reperfusion (I/R). Methods: Transient (15min) cerebral ischemia was induced by four-vessel occlusion procedure in SD rats. Immunoprecipitation (IP) and immunoblotting (IB) were performed to investigate the phosphorylation and interactions of proteins. The effects of lithium on tyrosine phosphorylation of NR2B and its interactions with PSD-95 and Src were examined. Results: Transient cerebral ischemia 15 rain followed by reperfusion 6h (I/R 6h) caused a significant increase in tyrosine phosphorylation of NR2B. Administration of LiCI for 7days before ischemia caused a profound decrease in tyrosine phosphorylation of NR2B. Similiarly. the interactions of NR2B and PSD-95 with Src were also enhanced by I/R 6h. moreover, these interactions were also inhibited by chronic lithium. Conclusion: Pretreatment with lithium decrease tyrosine phosphorylation of NR2B and interactions of NR2B and PSD-95 with Src during cerebral I/R.展开更多
The olfactory bulb(OB) is the first relay station in the olfactory system.In the OB,mitral/tufted cells(M/Ts),which are the main output neurons,play important roles in the processing and representation of odor informa...The olfactory bulb(OB) is the first relay station in the olfactory system.In the OB,mitral/tufted cells(M/Ts),which are the main output neurons,play important roles in the processing and representation of odor information.Recent studies focusing on the function of M/Ts at the single-cell level in awake behaving mice have demonstrated that odor-evoked firing of single M/Ts displays transient/long-term plasticity during learning.Here,we tested whether the neural activity of M/Ts and sniffing patterns are dependent on anticipation and reward in awake behaving mice.We used an odor discrimination task combined with in vivo electrophysiological recordings in awake,head-fixed mice,and found that,while learning induced plasticity of spikes and beta oscillations during odor sampling,we also found plasticity of spikes,beta oscillation,sniffing pattern,and coherence between sniffing and theta oscillations during the periods of anticipation and/or reward.These results indicate that the activity of M/Ts plays important roles not only in odor representation but also in salience-related events such as anticipation and reward.展开更多
Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neurosci...Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neuroscience research,the relationship between the recorded Ca^(2+)signals and direct electrophysiological measurements of neural activity remains elusive.Here,we simultaneously recorded odor-evoked Ca^(2+)and electrophysiological signals[single-unit spikes and local field potentials(LFPs)]from mitral/tufted cells in the olfactory bulb of awake,head-fixed mice.Odors evoked responses in all types of signal but the response characteristics(e.g.,type of response and time course)differed.The Ca^(2+)signal was correlated most closely with power in theβ-band of the LFP.The Ca^(2+)signal performed slightly better at odor classification than high-γoscillations,worse than single-unit spikes,and similarly toβoscillations.These results provide new information to help researchers select an appropriate method for monitoring neural activity under specific conditions.展开更多
Precise and reliable presentation of odorants to animals is crucial for olfactory studies.Although odor stimulation systems in anesthetized or awake,head-fixed animals are well established,temporally precise odor prese...Precise and reliable presentation of odorants to animals is crucial for olfactory studies.Although odor stimulation systems in anesthetized or awake,head-fixed animals are well established,temporally precise odor presentation in awake,freely moving animals remains a challenge.Here,we describe a new odor stimulation system which presents odors directly to the nostrils of freely moving mice.The system comprises 3 modules:an odor-delivery module,an odor-generation module,and a control module.The new system is precise and temporally reliable,and odor stimulation can be triggered by specific sniffing phases or other events.Moreover,the system can be combined with neural recordings,such as electrophysiology,and olfactory behavioral tests to investigate how neurons in the brain represent odor information during individual olfactory behaviors.This innovative odor stimulation system may replace traditional stimulation systems:It will enable precise odor presentation in a wide range of olfactory studies in freely moving animals.展开更多
Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalizat...Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalization of fear memory can generate anxiety-related disorders that afflict 10%-30%of individuals worldwide,especially during the epidemic situation[3,4].展开更多
Objective Postsynaptic density protein 95 (PSD-95) plays important roles in the regulation of glutamate signaling, such as that of N-methyl-D-aspartate receptors (NMDARs). In this study, the functional roles of PS...Objective Postsynaptic density protein 95 (PSD-95) plays important roles in the regulation of glutamate signaling, such as that of N-methyl-D-aspartate receptors (NMDARs). In this study, the functional roles of PSD-95 in tyrosine phosphorylafion of NMDAR subunit 2A (NR2A) and in apoptosis-like cell death induced by oxygen-glucose de- privation (OGD) in cultured rat cortical neurons were investigated. Methods We used immunoprecipitation and immuno- blotting to detect PSD-95 protein level, tyrosine phosphorylation level of NR2A, and the interaction between PSD-95 and NR2A or Src. Apoptosis-like cells were observed by 4,6-diamidino-2-phenylindole staining. Results Tyrosine phospho- rylation of NR2A and apoptosis-like cell death were increased after recovery following 60-min OGD. The increases were attenuated by pretreatment with antisense oligonucleotides against PSD-95 before OGD, but not by missense oligonucle- otides or vehicle. PSD-95 antisense oligonucleotides also inhibited the increased interaction between PSD-95 and NR2A or Src, while NR2A expression did not change under this condition. Conclusion PSD-95 may be involved in regulating NR2A tyrosine phosphorylation by Src kinase. Inhibition of PSD-95 expression can be neuroprotective against apoptosis- like cell death after recovery from OGD.展开更多
基金supported by the National Natural Science Foundation of China(No.81141080)Jiangsu Provincial Natural Science Foundation(SBK201340596)
文摘Objective:To test the effects of salidroside on formation and growth of glioma together with tumor microenvironment.Methods:Salidroside extracted from Rhodiola rosea was purified and treated on human glioma cells U251 at the concentration of 20 μg/mL.3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazolium bromide (MTT) assay for cytotoxicity and flow cytometry (FCM) for cell cycle analysis were performed.Then for in vivo study,xenotransplantation tumor model in nude mice was generated and treated with salidroside at the concentration of 50 mg/kg.d for totally 20 d.Body weight and tumor size were detected every 2 d after the treatment.The levels of 8-isoprostane,superoxide dismutase (SOD) and malondialdehyde (MDA),special markers for oxidative stress,were detected while immunofluoresence staining was performed for astrocyte detection.Results:For in vitro study,salidroside could decrease the viability of human glioma cells U251 and the growth of U251 cells at G0/G1 checkpoint during the cell cycle.For in vivo study,salidroside could also inhibit the growth of human glioma tissue in nude mice.The body weight of these nude mice treated with salidroside did not decrease as quickly as control group.In the tumor xenotransplantation nude mice model,mice were found of inhibition of oxidative stress by detection of biomarkers.Furthermore,overgrowth of astrocytes due to the stimulation of oxidative stress in the cortex of brain was inhibited after the treatment of salidroside.Conclusions:Salidroside could inhibit the formation and growth of glioma both in vivo and in vitro and improve the tumor microenvironment via inhibition of oxidative stress and astrocytes.
基金supported by the National Natural Science Foundation of China,No. 81671164 (to SHQ)the Natural Science Foundation of Jiangsu Province of China,No. BK20211348 (to SHQ)Xuzhou Basic Research Program,No. KC21030 (to LYH)。
文摘Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.
基金Supported by grants from the Education Departmental Natural Science Research Funds of Hebei and Jiangsu Provinces of China (200510604KJD310207)the Key Project of the National Natural Science Foundation of China (No. 30330190).
文摘Objective: To investigate the activation (phosphorylation) and subcellular localization of extracellular signal-regulated kinase (ERK1/2). as well as the possible mechanism, following cerebral ischemia and ischemia/reperfusion in rat hippocampus. Methods: Transient brain ischemia was induced by the four-vessel occlusion method in Sprague-Dawley rats. Western blot analysis. Results: During cerebral ischemia without reperfusion ERK1/2 activation immediately increased with a peak at 5 min and then decreased in the cytosol fraction, which was paralleled by the increase of ERK1/2 activation in the nucleus fraction. During reperfusion, ERK1/2 was activated with peaks occurring at 10 min in the cytosol and at 30 min in the nucleus, respectively. Under those conditions, the protein expressions had no significant change. In order to clarify the possible mechanism of ERKl/2 activation, the rats were intraperitoneally administrated with N-methyl-D-aspartate (NMDA) receptor antagonist dextromethorphan(DM), L-type voltage-gated Ca2+ channel (L-VGCC) antagonist nifedipine (ND) 20 min before ischemia, finding that DM and ND markedly prevented ERKl/2 activation of nucleus fraction induced by reperfusion. not by ischemia. Conclusion: These results suggested that the nuclear translocation mainly occurred during ischemia, while ischemia-reperfusion induced ERK1/2 activation both in the cytosol and the nucleus. Two type calcium channels contributed, at least partially, to the activation of ERK1/2.
文摘Polysaccharides of Momordica charantia have been reported to be the primary bioactive components that confer its antioxidant activity. To some degree, antioxidants may provide beneficial effects on neuronal damage induced by seizures. However, the protective effects of Momordica charantia polysaccharides (MCPs) on seizures remain unclear. In this study, our purpose was to investigate the effects of MCPs on oxidative stress and neurodegeneration in an experimental Kainic acid (KA)-induced rat seizure model. MCPs treatments decreased the level of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD) and catalase (CAT) in the hippocampus of the KA-induced animal model. Moreover, MCPs significantly attenuated KA-induced neuronal loss in the CA1 and CA3 hippocampal regions. Based on these results, MCPs exert neuroprotective effects by attenuating KA-induced neuronal damage in the brain through their free radical scavenging activities.
文摘Objective: To study the effects of chronic lithium on N-methyl-d-aspartate receptor subunit 2B (NR2B) tyrosine phosphorylation and the interactions of NR2B and PSD-95 with Src induced by cerebral ischemia/reperfusion (I/R). Methods: Transient (15min) cerebral ischemia was induced by four-vessel occlusion procedure in SD rats. Immunoprecipitation (IP) and immunoblotting (IB) were performed to investigate the phosphorylation and interactions of proteins. The effects of lithium on tyrosine phosphorylation of NR2B and its interactions with PSD-95 and Src were examined. Results: Transient cerebral ischemia 15 rain followed by reperfusion 6h (I/R 6h) caused a significant increase in tyrosine phosphorylation of NR2B. Administration of LiCI for 7days before ischemia caused a profound decrease in tyrosine phosphorylation of NR2B. Similiarly. the interactions of NR2B and PSD-95 with Src were also enhanced by I/R 6h. moreover, these interactions were also inhibited by chronic lithium. Conclusion: Pretreatment with lithium decrease tyrosine phosphorylation of NR2B and interactions of NR2B and PSD-95 with Src during cerebral I/R.
基金supported by the National Natural Science Foundation of China (31571082,31872771 and 31700895)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(16KJA180007)the Natural Science Foundation of Jiangsu Province (BK20170260)。
文摘The olfactory bulb(OB) is the first relay station in the olfactory system.In the OB,mitral/tufted cells(M/Ts),which are the main output neurons,play important roles in the processing and representation of odor information.Recent studies focusing on the function of M/Ts at the single-cell level in awake behaving mice have demonstrated that odor-evoked firing of single M/Ts displays transient/long-term plasticity during learning.Here,we tested whether the neural activity of M/Ts and sniffing patterns are dependent on anticipation and reward in awake behaving mice.We used an odor discrimination task combined with in vivo electrophysiological recordings in awake,head-fixed mice,and found that,while learning induced plasticity of spikes and beta oscillations during odor sampling,we also found plasticity of spikes,beta oscillation,sniffing pattern,and coherence between sniffing and theta oscillations during the periods of anticipation and/or reward.These results indicate that the activity of M/Ts plays important roles not only in odor representation but also in salience-related events such as anticipation and reward.
基金the National Natural Science Foundation of China(31872771,32070995,and 31900713)the National Demonstration Center for Experimental Basic Medical Science Education(Xuzhou Medical University).
文摘Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neuroscience research,the relationship between the recorded Ca^(2+)signals and direct electrophysiological measurements of neural activity remains elusive.Here,we simultaneously recorded odor-evoked Ca^(2+)and electrophysiological signals[single-unit spikes and local field potentials(LFPs)]from mitral/tufted cells in the olfactory bulb of awake,head-fixed mice.Odors evoked responses in all types of signal but the response characteristics(e.g.,type of response and time course)differed.The Ca^(2+)signal was correlated most closely with power in theβ-band of the LFP.The Ca^(2+)signal performed slightly better at odor classification than high-γoscillations,worse than single-unit spikes,and similarly toβoscillations.These results provide new information to help researchers select an appropriate method for monitoring neural activity under specific conditions.
基金supported by the National Natural Science Foundation of China(NSFC,31872771 and 32070995 to Anan Li,31872770 to Yufeng Shao)the Jiangsu Province Innovative and Entrepreneurial Team Program.
文摘Precise and reliable presentation of odorants to animals is crucial for olfactory studies.Although odor stimulation systems in anesthetized or awake,head-fixed animals are well established,temporally precise odor presentation in awake,freely moving animals remains a challenge.Here,we describe a new odor stimulation system which presents odors directly to the nostrils of freely moving mice.The system comprises 3 modules:an odor-delivery module,an odor-generation module,and a control module.The new system is precise and temporally reliable,and odor stimulation can be triggered by specific sniffing phases or other events.Moreover,the system can be combined with neural recordings,such as electrophysiology,and olfactory behavioral tests to investigate how neurons in the brain represent odor information during individual olfactory behaviors.This innovative odor stimulation system may replace traditional stimulation systems:It will enable precise odor presentation in a wide range of olfactory studies in freely moving animals.
基金supported by grants from the National Natural Science Foundation of China(81870852 and 82171199)the Qing Lan Project of Jiangsu Province,the Education Department of Jiangsu Province(18KJA320007)+3 种基金the Natural Science Foundation of Jiangsu Province(BK20181146 and BK20210911)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_2706,KYCX21_2703,and YCX21_2717)the Program on Basic Research Projects of Xuzhou City(KC21048)the Special Funds for Anesthesia Medical Research of Jiangsu Medical Association SYH-32021-0040(2021035).
文摘Dear Editor,Depending on the perceived threat in the environment,organisms can express a broad spectrum of behaviors,ranging from exploration to defensive behaviors[1,2],such as fear response and avoidance.Generalization of fear memory can generate anxiety-related disorders that afflict 10%-30%of individuals worldwide,especially during the epidemic situation[3,4].
基金supported by the National Natural Science Foundation of China (30170220)Xuzhou Science and Technology Bureau of China (XZZD1157)+1 种基金Xuzhou Medical College (2011KJZ03)A Project Funded by the Priority Academic Program Development of Jingsu Higher Education Institutions
文摘Objective Postsynaptic density protein 95 (PSD-95) plays important roles in the regulation of glutamate signaling, such as that of N-methyl-D-aspartate receptors (NMDARs). In this study, the functional roles of PSD-95 in tyrosine phosphorylafion of NMDAR subunit 2A (NR2A) and in apoptosis-like cell death induced by oxygen-glucose de- privation (OGD) in cultured rat cortical neurons were investigated. Methods We used immunoprecipitation and immuno- blotting to detect PSD-95 protein level, tyrosine phosphorylation level of NR2A, and the interaction between PSD-95 and NR2A or Src. Apoptosis-like cells were observed by 4,6-diamidino-2-phenylindole staining. Results Tyrosine phospho- rylation of NR2A and apoptosis-like cell death were increased after recovery following 60-min OGD. The increases were attenuated by pretreatment with antisense oligonucleotides against PSD-95 before OGD, but not by missense oligonucle- otides or vehicle. PSD-95 antisense oligonucleotides also inhibited the increased interaction between PSD-95 and NR2A or Src, while NR2A expression did not change under this condition. Conclusion PSD-95 may be involved in regulating NR2A tyrosine phosphorylation by Src kinase. Inhibition of PSD-95 expression can be neuroprotective against apoptosis- like cell death after recovery from OGD.