Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neu...Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neural circuit tracing.Anterograde labeling was achieved by injecting anterograde self-complementary adeno-associated viruses(scAAVs)into the IC.Retrograde tracing involved NTS injections of either retrograde scAAVs or FluoroGold(FG),combined with immunofluorescence histochemical staining to identify IC-originating projection neurons.For postsynaptic neurochemical phenotype characterization,IC was injected with AAV2/1-CaMKII-Cre,while a mixture of AAV2/9-Syn-DIO-mCherry and AAV2/9-VGAT1-EGFP was injected into the NTS.The rats were allowed to survive for one week following scAAVs or FG injection or four weeks after recombinase-dependent systems injection.Then the rats were sacrificed,and serial brain sections were prepared for immunofluorescence histochemical staining(brain section containing FG)and subsequent fluorescence/confocal microscopic analysis.Results:(1)Anterograde viral tracing re-vealed dense axonal terminals from the IC projecting to the medial subnucleus of the NTS,while retrograde tracing re-vealed that IC neurons projecting to the NTS were predominantly localized within the dysgranular layer;(2)IC-NTS projection neurons were exclusive glutamatergic(100%,n=3);(3)NTS neurons receiving IC inputs were mainly lo-calized in the medial subnucleus,and were predominantly GABAergic(79.8±3.2%,n=3).Conclusion:The pres-ent results indicate that a descending pathway from excitatory neurons of the IC terminates onto inhibitory neurons of the NTS,which might represent a potential neuromodulatory target for visceral pain disorders.展开更多
OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tiv...OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tive.Here,we hypothesize that dysfunction of central TGR5 may contribute to the pathogene⁃sis of depression.METHODS In well-established chronic social defeat stress(CSDS)and chronic restraint stress(CRS)models of depression,we investigated the functional roles of TGR5 in CA3 pyramidal neurons(PyNs)and underlying mech⁃anisms of the neuronal circuit in depression(for in vivo studies,n=10;for in vitro studies,n=5-10)using fiber photometry;optogenetic,chemoge⁃netic,pharmacological,and molecular profiling techniques;and behavioral tests.RESULTS Both CSDS and CRS most significantly reduced TGR5 expression of hippocampal CA3 PyNs.Genetic overexpression of TGR5 in CA3 PyNs or intra-CA3 infusion of INT-777,a specific agonist,protected against CSDS and CRS,exerting sig⁃nificant antidepressant-like effects that were mediated via CA3 PyN activation.Conversely,genetic knockout or TGR5 knockdown in CA3 facilitated stress-induced depression-like behav⁃iors.Re-expression of TGR5 in CA3 PyNs rather than infusion of INT-777 significantly improved depression-like behaviors in Tgr5 knockout mice exposed to CSDS or CRS.Silencing and stimula⁃tion of CA3 PyNs→somatostatin-GABAergic(gamma-aminobutyric acidergic)neurons of the dorsolateral septum circuit bidirectionally regulat⁃ed depression-like behaviors,and blockade of this circuit abrogated the antidepressant-like effects from TGR5 activation of CA3 PyNs.CON⁃CLUSION TGR5 can regulate depression via CA3 PyNs→somatostatin-GABAergic neurons of dorsolateral septum transmission,suggesting that TGR5 could be a novel target for developing antidepressants.展开更多
OBJECTIVE To investigate the effect of quercetin on primary cultured newborn rat cortex neuron cell which is estrogen depletion,and discuss the possible mechanism,to provide new ideas and strategies for developing a d...OBJECTIVE To investigate the effect of quercetin on primary cultured newborn rat cortex neuron cell which is estrogen depletion,and discuss the possible mechanism,to provide new ideas and strategies for developing a drug of neurodegenerative disease.METHODS Rat cortex neurons were isolated from one day old Sprague Dawley rats and treated with estrogen,quercetin and estrogen receptor antagonists(ICI182,780).Cell viability was determined by MTT assay,neurite outgrowth was measured by fluorescent microsope and estrogen receptors were determine by Western blot.RESULTS Quercetin functions like estrogen to increase cortex neuronal cell viability,the Que(50,100μmol·L^(-1))group compared with the control group could significantly improve the activity of the cortical neurons(P<0.05).It can also increase neurite out growth,the Que(50,100μmol·L^(-1))group significantly promoted the formation of synapse,most of the neurons were full,and the synapses of neurons became thick,growth,and connect to a dense neural network.And in the Western blot experiments,Que(50,100μmol·L^(-1))group could obviously increase the expression of estrogen receptor alpha protein,in addition,the neural protective effect of quercetin can be inhibited by ICI182,780.CONCLUSION Quercetin like estrogen can protected cortex neuronal and the effect of quercetin on cortex neuronal cells was mediated by estrogen receptor alpha.展开更多
A neuron proportion integration (PI) control strategy for semi-active suspension system of tracked vehicle was proposed based on its unique structure and the multiple and complex environment of the driving traffic. An...A neuron proportion integration (PI) control strategy for semi-active suspension system of tracked vehicle was proposed based on its unique structure and the multiple and complex environment of the driving traffic. An adaptive genetic algorithm is used to optimize the parameters of the neuron PI controller. The simulation result of the neuron PI control for semi-active suspension system of tracked vehicle indicates that the vertical amplitude,pitch angle and vertical acceleration of the vehicle are well controlled. The root mean square (RMS) of the vertical amplitude decreases by 37.2%,and 45.2% for the pitch angle,38.6% for the vertical acceleration. The research of neuron PI control experiment for the semi-active suspension system of the tracked vehicle model mining in benthal indicates that the RMS of the weight acceleration vibrating along the vertical direction decreases by 29.5%,the power spectral density resonance peak of the acceleration of the car body decreases by 23.8%.展开更多
A filter algorithm based on cochlear mechanics and neuron filter mechanism is proposed from the view point of vibration.It helps to solve the problem that the non-linear amplification is rarely considered in studying ...A filter algorithm based on cochlear mechanics and neuron filter mechanism is proposed from the view point of vibration.It helps to solve the problem that the non-linear amplification is rarely considered in studying the auditory filters.A cochlear mechanical transduction model is built to illustrate the audio signals processing procedure in cochlea,and then the neuron filter mechanism is modeled to indirectly obtain the outputs with the cochlear properties of frequency tuning and non-linear amplification.The mathematic description of the proposed algorithm is derived by the two models.The parameter space,the parameter selection rules and the error correction of the proposed algorithm are discussed.The unit impulse responses in the time domain and the frequency domain are simulated and compared to probe into the characteristics of the proposed algorithm.Then a 24-channel filter bank is built based on the proposed algorithm and applied to the enhancements of the audio signals.The experiments and comparisons verify that,the proposed algorithm can effectively divide the audio signals into different frequencies,significantly enhance the high frequency parts,and provide positive impacts on the performance of speech enhancement in different noise environments,especially for the babble noise and the volvo noise.展开更多
Introduction Neurons are situated in a microenvironment composed of various biochemical and biophysical cues,where stretching is thought to have a major impact on neurons.For instance,during a moderate traumatic brain...Introduction Neurons are situated in a microenvironment composed of various biochemical and biophysical cues,where stretching is thought to have a major impact on neurons.For instance,during a moderate traumatic brain impact,the injury region in axons exhibits significant longitudinal strain;and in a rat model of spinal cord injury,the most severe axonal injury is located in the largest strain region.Stretching may result in microstructural changes in neural tissue and further leading to abnormal electrophysiological function.Hence,it is of great importance to understand the coupled mechanoelectricalbehaviors of neurons under stretching.In spite of significant experimental efforts,the underlying mechanism remains elusive,more works are needed to provide a detailed description of the process that leads to the observed phenomena.Mathematical modeling is a powerful tool that offers a quantitative description of the underlying mechanism of an observed biological phenomenon,including mechanical and electrophysiological behaviors of neurons.Thus,we developed a mechanoelectrical coupling model of neurons under stretching in this study.Mathematical model The mathematical model consists of three submodels,i.e.,the mechanical submodel,the mechanoelectrical coupling submodel and the electrophysiological submodel.The mechanical submodel deals with the relationship between stretching and the deformation of axons,which has specially considered the plastic deformation of axons.The electrophysiological submodel characterizes the feature of neuronal action potential(AP),which is based on the classical H-H model and the cable theory.The mechanoelectrical coupling submodel links the mechanical and electrophysiological submodels through strain-induced equivalent circuit parameter alteration and ion channel injury.Besides,we have discussed a more general deformation condition,where an expanded model coupling the axonal deformation and electrophysiology alteration was explored.As the most essential parameters in an electrophysiological assessment,the amplitude of the AP,the neuronal firing frequency and the electrophysiological signal conduction velocity,which could be affected by stretching,were used as outputs of the model.Results&discussion To understand the mechanoelectrical coupling of neurons under stretching,we developed a mechanoelectrical coupling model.To verify the model,we simulated a slow stretching on an axon following the experimental study in the literature,we observed that as the strain increases,the peak AP declines faster,which is consistent with the experimental data.Moreover,the reduced AP cannot be restored to the original peak,implying that the damage is irreversible.The simulation results also predict that strain induces a more frequent neuronal firing and a faster conduction.In a realistic situation,in addition to stretching,the loading condition is very complicated,which may induce complex axonal deformation(e.g., necking and swelling along the axons).We also simulated such necking deformation impairment and observed that the AP amplitude decreases at the necking region and recovers after that,indicating a blockage of the AP;and the conduction velocity decreases with the increase in deformation degree.Conclusions In this study,we developed a mechanoelectrical coupling model of neurons under stretching with consideration of axonal plastic deformation.With the model,we found that the effect of mechanical loading on electrophysiology mainly manifests as decreased membrane AP amplitude,a more frequent neuronal firing and a faster electrophysiological signal conduction.The model predicts not only stretch-induced injury but also a more gene ral necking deformation case,which may someday be revealed in future by experiments,providing a reference for the prediction and regulation of neuronal function under mechanical loadings.展开更多
Temporal lobe epilepsy(TLE) is a common type of epilepsy and is not well controlled by current treatments.The frequent failure to treat TLE may be due to our lack of precise cellular/circuit mechanisms underlying TLE....Temporal lobe epilepsy(TLE) is a common type of epilepsy and is not well controlled by current treatments.The frequent failure to treat TLE may be due to our lack of precise cellular/circuit mechanisms underlying TLE.The early series of our studies have proved the success of low-frequency stimulation treatment for epilepsy,which was mainly depending on the stimulation target,the stimulation frequency and stimulation time(the therapeutic-window phenomenon).Now,by using optogenetics,viral tracing,multiple-channel EEG analysis,imaging,electrophysiology and pharmacology strategies,we are continued to investigate the circuit mechanism of therapeutic deep brain stimulation,and found that entorhinal principal neurons mediate antiepileptic ″ glutamatergic-GABAergic″ neuronal circuit for brain stimulation treatments of epilepsy.Meanwhile,we are currently focusing on the interplay of inhibitory and excitatory network in the key input/output regions of the hippocampus that related to the generation of in TLE.Specially,we found that depolarized GABAergic signaling in subicular microcircuit mediates generalized seizures in TLE and a direct septal cholinergic circuit attenuates TLE through driving hippocampal somatostatin inhibition.These findings may be of therapeutic interest in understanding the pathological neuronal circuitry in TLE and further the development of novel therapeutic approaches or drug targets.展开更多
Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two d...Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two diseases,and amylin oligomerization in the brain provided a novel risk target for developing AD.Although cumulative studies reported that amylin aggregation induced cytotoxicity in pancreatic beta cells by altering Ca2+homeostasis,fewer studies investigated the effect of amylin on hippocampal neuron.To address this question,it was investigated the effect of amylin on primary cultured rat hippocampal neurons by calcium imaging and whole-cell patch clamp recording in this study,while the results revealed that human amylin(hAmylin) but not rat amylin or pramlintide(hAmylin analgue) produced a rapid increase in intracellular calcium in a dose dependent manner.This effect relied on extracellular calcium and not abolished by amylin receptor antagonist AC187.Additionally,the calcium increase induced by hAmylin was dependent onvoltage-gated Ca2+channels,especially L-type Ca2+channel activation.In whole-cell recording hAmylin could depolarize membrane potential and increase the cell exitability.Moreover,application of transient receptor potential vanilloid(TRPV) antagonist ruthenium red could abolish part of the intracellular calcium increase.Single cell RT-PCR revealed that TRPV4 mRNA expressed in most of the reactive neuron and selective TRPV4 antagonist HC067047 inhibited the intacellular calcium increasing.These results indicated that hAmylin aggregation precipitating on the neuron membrane activated TRPV4 channels and then triggered membrane voltage gated calcium channel opening followed by membrane depolarization,expressing that TRPV4 is a key molecular target for the cytotoxic effect of hAmylin on cultured neurons.展开更多
OBJECTIVE To study the function of neuronal nitric oxide synthase(nNOS) in the dentate gyrus(DG) in the pathology of epilepsy.METHODS The expression of nNOS in the DG was measured by qPCR and Western blotting in mice ...OBJECTIVE To study the function of neuronal nitric oxide synthase(nNOS) in the dentate gyrus(DG) in the pathology of epilepsy.METHODS The expression of nNOS in the DG was measured by qPCR and Western blotting in mice 3 and 12 h,1,7,14,and 60 d after treatment with pilocarpine(280 mg·kg-1,ip,one time).We constructed a type of lentiovirus encoding the full length cDNA of nNOS(LV-nNOS-GFP) and injected it and LV-GFP(1 μL) into the DG of the hippocampus 7 d after pilocarpine-induced seizure.The occurrence of epileptic spikes and spontaneous seizure(SRS)were monitored through electroencephalo-graph(EEG) and the protein expression was confirmed by Western blotting.We also constructed a lentioviral vehicle to interfere the expression of nNOS mRNA,which was named as LV-n NOSRNAi-GFP.A volume of 1 μL of LV-nNOS-RNAiGFP or LV-GFP was injected into the DG of the hippocampus 7 d before pilocarpine-induced seizure followed by EEG record and protein detection 2 months later.By EEG,we compared the susceptibility of nNOS knockout and wild-type mice to seizure induction and the development of epilepsy.In addition,we measured the influence of nNOS knockout on the excitability of dentate cells including mEPSC and mIPSC by using patch clamp technique.RESULTS Western blotting and qPCR measurement showed that the mRNA and protein expression of nNOS in the DG was not significantly changed in pilocarpinetreated mice compared with control mice.But the both m RNA and protein expression of nNOS decreased 7,14 and 60 d after treatment with pilocarpine(280 mg·kg-1,ip,one time).With infection of LV-nNOS-GFP in the DG,the decreased level of nNOS was recovered 7 d after seizure induction and the frequency of epileptic spikes and SRS were reversed by nNOS overexpression.We found that nNOS knockout caused a higher susceptive level to seizure induction by pilocarpine.Re-expression of nNOS in the DG of nNOS knockout mice relived the severity of epilepsy.By patch clamp recording,we found that there was no significant difference in the amplitude of mEPSC and mIPSC between nNOS knockout and wild-type mice,but the frequency of mEPSC was increased in nN OS knockout mice.Consistently,knockdown of nNOS by injection of LV-nNOS-RNAi-GFP into the DG caused higher frequency of epileptic spikes and SRS 2 months after pilocarpine-induced seizure.CONCLUSION Neurons expressing nNOS in the DG play an important role in the development of epilepsy.展开更多
OBJECTIVE To understand the underlying mechanisms of drug resistant temporal lobe epilepsy(TLE).METHODS In vivo and vitro electrophysiology,optogenetics and chemogenetics were used in a classic multi-drug resistant TL...OBJECTIVE To understand the underlying mechanisms of drug resistant temporal lobe epilepsy(TLE).METHODS In vivo and vitro electrophysiology,optogenetics and chemogenetics were used in a classic multi-drug resistant TLE model.RESULTS Subicular pyramidal neuron activity was not inhibited by the anti-epileptic drug phenytoin in drug resistant rats.This phenomenon was specific to the subiculum,but did not involve surrounding temporal lobe regions.Selective inhibition of subicular pyramidal neurons by both optogenetics and chemogenetics reversed drug resistance.In contrast,selective activation of subicular pyramidal neurons directly induced drug resistance in drug responsive rats.Furthermore,long-term low frequency stimulation at the subiculum,which is clinically feasible,inhibited the activity of subicular pyramidal neurons and reversed drug resistance.CONCLUSION Subicular pyramidal neurons might be a key ″ switch″ mediating drug resistance in TLE and represent a new potential target for more precise treatment of drug resistant TLE.展开更多
OBJECTIVE To explore the effect of icariside Ⅱ(ICS Ⅱ) on oxygen-glucose deprivation and reoxygenation(OGD/R)-induced injury in cerebral cortical neuronal cels.METHODS Primary cerebral cortical neuronal cells were de...OBJECTIVE To explore the effect of icariside Ⅱ(ICS Ⅱ) on oxygen-glucose deprivation and reoxygenation(OGD/R)-induced injury in cerebral cortical neuronal cels.METHODS Primary cerebral cortical neuronal cells were deprived of oxygen and glucose for 2 h to simulate ischemic stroke injury in vitro.The experiment was divided into 8 groups,which were control,control+ICSⅡ 25 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ(6.25,12.5,25 μmol·L^(-1)),OGD/R+3-methyladenine(3-MA) and OGD/R+Rapamycin(Rap).The protective effect of ICS Ⅱ were detected by MTT assay and lactate dehydrogenase(LDH),respectively.Autophagic flux and autophagy related proteins expressions were detected by using adenovirus harboring tf-LC3 and Western blotting,respectively.RESULTS Compared with OGD/R group,the cell viability treated with ICSⅡwas elevated in a concentration-dependent manner,and the leakage rate of LDH was lowed.Moreover,ICSⅡ not only suppressed OGD/R-induced autophagic flux,but also inhibited the increase of LC3-Ⅱ/LC3-Ⅰ ratio and Beclin 1 after OGD/R insulted.CONCLUSION ICS Ⅱ exerts protective effects on OGD/R-induced cerebral cortical neuronal cells through inhibiting excessive autophagy.展开更多
Oxidative stress is one of the main causes of neurodegenerative diseases such as Alzheimer disease(AD).Our previous studies have shown that artemisinin,a anti-malaria Chinese medicine,with neuroprotective effect,howev...Oxidative stress is one of the main causes of neurodegenerative diseases such as Alzheimer disease(AD).Our previous studies have shown that artemisinin,a anti-malaria Chinese medicine,with neuroprotective effect,however,the antioxidative effect of artemisinin and its potential mechanism remain to be elucidated.In the present study,the protective effect and the underlying mechanism of artemisinin against injury of hydrogen peroxide(H_2O_2) in SH-SY5Y and hippocampal neurons were studied.Our results show that artemisinin protected SH-SY5Y and hippocampal neuronal cells from H_2O_2-induced cell death at clinically relevant concentrations in a concentration-dependent manner.Further studies showed that artemisinin significantly reduced cell death caused by H_2O_2 by restoring nuclear morphology,abnormal changes in intracellular ROS,activation of caspase 3,lactate dehydrogenase release and mitochondrial membrane potential.Hoechst staining and flow cytometry showed that artemisinin significantly reduced the apoptosis of SH-SY5Y cells exposed to H_2O_2.Western blotting analysis showed that artemisinin stimulated the phosphorylation and activation of AMP-activated protein kinase(AMPK) in SH-SY5Y cells in a time and concentration-dependent manner,whereas the application of AMPK inhibitor Compound C or decrease in expression of AMPKα with shRNA specific for AMPKα blocked the protective effect of artemisinin.Similar results were obtained in primary cultured hippocampal neurons.Taken together,these results indicate that artemisinin can protect neuronal cells from oxidative damage,at least in part through the activation of AMPK.Because artemisinin is relatively inexpensive and has few side effects,our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.展开更多
OBJECTIVE Circular RNAs(circRNAs) are highly expressed in the brain and involved in various central nervous system diseases.However,the potential role of circRNAs in ischemic brain injury remains largely unknown.The p...OBJECTIVE Circular RNAs(circRNAs) are highly expressed in the brain and involved in various central nervous system diseases.However,the potential role of circRNAs in ischemic brain injury remains largely unknown.The present study investigated the functional significance of a circular RNA TLK1(circTLK1) in cerebral ischemic injury.METHODS The expression of circTLK1,neurological deficit scores,infarct volume,and long-term neurological deficits were examined in a rodent model of middle cerebral artery occlusion using real-time polymerase chain reaction,triphenyltetrazolium chloride staining,magnetic resonance imaging,GolgiCox staining and behavior tests.Neuronal injury was undertaken in primary cultured cortical neurons challenged by oxygen-glucose deprivation using Western blotting and immunostaining.The interaction between circTLK1 and miR-335-3 p was examined using fluorescence in situ hybridization and affinity isolation assay.The downstream target of miR-335-3 p-TIPARP was determined by luciferase assay and Western blotting assay.RESULTS CircTLK1 levels were significantly increased in brain tissues in a mouse model of focal cerebral ischemia and reperfusion.Knockdown of circTLK1 expression significantly decreased infarct volumes,attenuated neuronal injury,and improved subsequent long-term neurological deficits.Furthermore,circT LK1 functions as an endogenous microRNA-335-3 p sponge to inhibit miR-335-3 p activity,resulting in the inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible polymerase expression and subsequent attenuation of neuronal injury.Clinical studies confirmed the up-regulation of circT LK1 in plasma of patients with ischemic stroke.CONCLUSION CircTLK1 and its underlying mechanisms are involved in ischemic brain injury,suggesting circTLK1 as a potential therapeutic target for ischemic stroke.展开更多
OBJECTIVE To research the effect of naringenin(NAR) on LPS-induced dopaminergic neurons damage and its potential mechanism.METHODS Rats were randomly divided into the following six groups(n=10):control(0.9% NaCl),NAR ...OBJECTIVE To research the effect of naringenin(NAR) on LPS-induced dopaminergic neurons damage and its potential mechanism.METHODS Rats were randomly divided into the following six groups(n=10):control(0.9% NaCl),NAR alone(100 mg·kg-1),LPS(5 μg),LPS+NAR(50 mg·kg-1) and LPS+NAR(100 mg·kg-1).Rats were received a single LPS unilateral injection into the SN pars compacts,after seven daily intragastric administration of NAR,rats′ behavior was analyzed by rotarod test.Then,the expression of TH,IBA-1 and NLRP3 inflammasome were analyzed by Western blotting and immunofluorescence.In vitro experiments,BV-2 cel s were treated with different doses of NAR,and 1 h later,LPS(1 g·L^(-1)) was added to the medium for 24 h,then collect the culture medium and protein for later experiments.The production of IL-1β and IL-18 in culture medium were tested by ELISA,and the production of NO was detected by Griess reagent.The expression of IBA-1,NLRP3 and p-caspase 1 were detected by Western blotting.MN9 D cells were co-cultured with BV2 cells to mimic the animal experiments.MTT assay was used to analyzed the viability of MN9 D cells,and the expression of TH was detected by Western blotting.RESULTS NAR(100 mg · kg-1) could significantly improve the time of rats on the rotating(116.73 s vs 185.45 s,P<0.05).The result of the pathological analysis also suggested that NAR could decrease the activation of microglia as well as the expression of NLRP3 Inflammasome.In addition,NAR also could suppress the expression of pro-inflammatory factor levels,such as IL-1β(P<0.05),IL-18(P<0.05),and the protection of NAR could be inhibited by siR NA NLRP3.Moreover,an in vitro co-culture system with BV2 and MN9 D cells wasused to find the protection of NAR must via microglia,while there is no effect of NAR were directly added to MN9 D cells.CONCLUSION NAR protection of LPS-induced dopaminergic neurons damage might be through mediating NLRP3 inflammasome.展开更多
Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in th...Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in the pathological progression of cerebral ischemia and neurodegenerative diseases including Parkinson disease(PD).Therefore,it is important to find effective therapeutic targets to attenuate inflammation and delay the progression of brain injury.Cysteinyl leukotrienes(CysLTs) are potent inflammatory mediators synthesized from arachidonic acid by 5-lipoxygenase(5-LOX) in the central nervous system.Two distinct G-protein-coupled receptors,CysLT1 R and CysLT2 R,mediate most of the known CysLTs biological responses.Accumulating evidence has demonstrated that postischemic inflammation and neuronal loss are mediated by 5-LOX and CysLTRs fol owing focal cerebral ischemia.We recently reported that the expression of 5-LOX,CysLT1R and inflammatory vascular cell adhesion molecule-1(VCAM-1) was upregulated in the hippocampus of rats with transient global cerebral ischemia,which was closely associated with delayed neuronal death in the hippocampal CA1 area.5-LOX inhibitor zileuton,CysLT1R antagonist ONO-1078 and montelukast dose-dependently reduced hippocampal CA1 neuronal death and inhibited the increased expression of 5-LOX and VCAM-1.In vitro ischemia-like injury in 5-LOXtransfected PC12 cells,oxygen-glucose deprivation(OGD) induced cell death mediated by5-LOX via ROS/P38 MAPK pathway.The nonselective 5-LOX inhibitor caffeic acid inhibited OGDstimulated activation of 5-LOX and ROS/P38 MAPK signaling and improved neuronal survival.In PD model,high concentrations of rotenone caused directly PC12 neurotoxicity,which was modulated by 5-LOX and abolished by suppression of 5-LOX.It is well known that microglia is major modulators of inflammatory response after brain injury.Overactivated microglia and production of proinflammatory cytokine IL-1β,IL-6 and TNF-α contribute to the neuroinflammation and brain injury.5-LOX,CysLT1R and CysLT2R are involved in microglial activation and resultant neurotoxic responses.It has been found that low concentrations of rotenone can activate 5-LOX and CysLT1R on microglial cells to enhance microglial inflammation and microglia-dependent neuronal death in vitro.5-LOX inhibitor zileuton and CysLT1R antagonist montelukast protected neurons from microglia-dependent rotenone neurotoxicity.Furthermore,lipopolysaccharide(LPS)induced microglial activation and microglial neurotoxicity mediated by CysLT2R in vitro.Both pharmacological blockade(CysLT2R antagonist HAMI3379) and RNA interference(specific short hairpin RNA) of CysLT2 R significantly attenuated LPS-triggered microglial inflammation and subsequent neuronal death.Collectively,the present results indicate the role of 5-LOX and CysLTRs in neuroinflammation and brain injury.Modulation of 5-LOX and CysLTRs may be potential therapeutic approaches for inflammation-related brain disorders such as cerebral ischemia and PD.However,further research is needed to clarify the mechanisms underlying the regulation of neuinflammatory processes by 5-LOX and CysLTRs.展开更多
OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported t...OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported to mediatesleepbehavior for adenosine.We hypothesized that the A2AR-expressing neurons in the striatum are involved in sleep-wake regulation.METHODS We employed a chemogenetic technique,designer receptor exclusively activated by designer drug(DREADD),to specifically and non-invasively manipulate the neuron activity based on the principle of Cre/Lox P recombination,EEG/electromyogram recording for sleep-wake behaviors,the neural tracing approach toselectively visualize the perikarya of A2AR-expressing neurons and their axons by adeno-associated virus(AAV)encoding humanized Renilla green fluorescent(hr GFP)as a tracerin A2AR-Cre mice.In addition,we used immunoelectron microscopy,patch-clamp technique,and optogenetics in A2AR-Cre mice to selectively characterize the synapse and functional connectivity between the A2AR-expressing neurons and the neuron of their downstream targets in vitro.RESULTS The activation of A2AR-expressing neurons in rostral,centromedial and centrolateral striatum increased non-rapid eye movement(non-REM,NREM)sleep,concomitant with a reduction in wakefulness,whereas the activation of A2AR-expressing neurons in caudal striatum didn′t alter sleep-wake profiles at all.Topographical projections in the sagittal section showed that the axons of A2ARexpressing neurons from rostral striatum distributed in the rostral external globuspallidus(GPe)with a discoidal region paralleled to the striato-pallidal border,while the axons of the A2AR-expressing neurons from the central striatum not only distributed in the rostral GPe,but also in the caudal GPe with a similar distributing pattern as did in rostral neurons.However,the axons of A2ARexpressing neurons from caudal striatum just scattered in the caudal GPe.Based on our anatomical findings and patch-clamp technique combining with optogenetics,we found that A2AR neurons in the rostral striatum preferentially formed inhibitory synapses with parvalbumin(PV)-positive neurons in the rostral GPe,while A2AR neurons in the caudal striatum preferentially formed inhibitory synapses with PV-negative neurons in the caudal GPe.CONCLUSION The present results indicated that the A2AR-expressing neurons in rostral and central striatum are involved in sleep-wake regulation,probably via innervating PV-positive neurons in the GPe.展开更多
文摘Objective:To anatomically and phenotypically characterize the insular cortex(IC)-nucleus tractus soli-tari(NTS)neural pathway.Methods:Adult male Sprague-Dawley rats were divided into three experimental cohorts for neural circuit tracing.Anterograde labeling was achieved by injecting anterograde self-complementary adeno-associated viruses(scAAVs)into the IC.Retrograde tracing involved NTS injections of either retrograde scAAVs or FluoroGold(FG),combined with immunofluorescence histochemical staining to identify IC-originating projection neurons.For postsynaptic neurochemical phenotype characterization,IC was injected with AAV2/1-CaMKII-Cre,while a mixture of AAV2/9-Syn-DIO-mCherry and AAV2/9-VGAT1-EGFP was injected into the NTS.The rats were allowed to survive for one week following scAAVs or FG injection or four weeks after recombinase-dependent systems injection.Then the rats were sacrificed,and serial brain sections were prepared for immunofluorescence histochemical staining(brain section containing FG)and subsequent fluorescence/confocal microscopic analysis.Results:(1)Anterograde viral tracing re-vealed dense axonal terminals from the IC projecting to the medial subnucleus of the NTS,while retrograde tracing re-vealed that IC neurons projecting to the NTS were predominantly localized within the dysgranular layer;(2)IC-NTS projection neurons were exclusive glutamatergic(100%,n=3);(3)NTS neurons receiving IC inputs were mainly lo-calized in the medial subnucleus,and were predominantly GABAergic(79.8±3.2%,n=3).Conclusion:The pres-ent results indicate that a descending pathway from excitatory neurons of the IC terminates onto inhibitory neurons of the NTS,which might represent a potential neuromodulatory target for visceral pain disorders.
文摘OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tive.Here,we hypothesize that dysfunction of central TGR5 may contribute to the pathogene⁃sis of depression.METHODS In well-established chronic social defeat stress(CSDS)and chronic restraint stress(CRS)models of depression,we investigated the functional roles of TGR5 in CA3 pyramidal neurons(PyNs)and underlying mech⁃anisms of the neuronal circuit in depression(for in vivo studies,n=10;for in vitro studies,n=5-10)using fiber photometry;optogenetic,chemoge⁃netic,pharmacological,and molecular profiling techniques;and behavioral tests.RESULTS Both CSDS and CRS most significantly reduced TGR5 expression of hippocampal CA3 PyNs.Genetic overexpression of TGR5 in CA3 PyNs or intra-CA3 infusion of INT-777,a specific agonist,protected against CSDS and CRS,exerting sig⁃nificant antidepressant-like effects that were mediated via CA3 PyN activation.Conversely,genetic knockout or TGR5 knockdown in CA3 facilitated stress-induced depression-like behav⁃iors.Re-expression of TGR5 in CA3 PyNs rather than infusion of INT-777 significantly improved depression-like behaviors in Tgr5 knockout mice exposed to CSDS or CRS.Silencing and stimula⁃tion of CA3 PyNs→somatostatin-GABAergic(gamma-aminobutyric acidergic)neurons of the dorsolateral septum circuit bidirectionally regulat⁃ed depression-like behaviors,and blockade of this circuit abrogated the antidepressant-like effects from TGR5 activation of CA3 PyNs.CON⁃CLUSION TGR5 can regulate depression via CA3 PyNs→somatostatin-GABAergic neurons of dorsolateral septum transmission,suggesting that TGR5 could be a novel target for developing antidepressants.
基金supported by Science and Technology Research Project of Hebei Higher School,Hebei Education Department(ZD2015131)Natural Science Foundation of Hebei Province(H2012405016)
文摘OBJECTIVE To investigate the effect of quercetin on primary cultured newborn rat cortex neuron cell which is estrogen depletion,and discuss the possible mechanism,to provide new ideas and strategies for developing a drug of neurodegenerative disease.METHODS Rat cortex neurons were isolated from one day old Sprague Dawley rats and treated with estrogen,quercetin and estrogen receptor antagonists(ICI182,780).Cell viability was determined by MTT assay,neurite outgrowth was measured by fluorescent microsope and estrogen receptors were determine by Western blot.RESULTS Quercetin functions like estrogen to increase cortex neuronal cell viability,the Que(50,100μmol·L^(-1))group compared with the control group could significantly improve the activity of the cortical neurons(P<0.05).It can also increase neurite out growth,the Que(50,100μmol·L^(-1))group significantly promoted the formation of synapse,most of the neurons were full,and the synapses of neurons became thick,growth,and connect to a dense neural network.And in the Western blot experiments,Que(50,100μmol·L^(-1))group could obviously increase the expression of estrogen receptor alpha protein,in addition,the neural protective effect of quercetin can be inhibited by ICI182,780.CONCLUSION Quercetin like estrogen can protected cortex neuronal and the effect of quercetin on cortex neuronal cells was mediated by estrogen receptor alpha.
基金Project(2010GK3091) supported by Industrial Support Project in Science and Technology of Hunan Province, ChinaProject(10B058) supported by Excellent Youth Foundation Subsidized Project of Hunan Provincial Education Department, China
文摘A neuron proportion integration (PI) control strategy for semi-active suspension system of tracked vehicle was proposed based on its unique structure and the multiple and complex environment of the driving traffic. An adaptive genetic algorithm is used to optimize the parameters of the neuron PI controller. The simulation result of the neuron PI control for semi-active suspension system of tracked vehicle indicates that the vertical amplitude,pitch angle and vertical acceleration of the vehicle are well controlled. The root mean square (RMS) of the vertical amplitude decreases by 37.2%,and 45.2% for the pitch angle,38.6% for the vertical acceleration. The research of neuron PI control experiment for the semi-active suspension system of the tracked vehicle model mining in benthal indicates that the RMS of the weight acceleration vibrating along the vertical direction decreases by 29.5%,the power spectral density resonance peak of the acceleration of the car body decreases by 23.8%.
基金Project(17KJB510029)supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions,ChinaProject(GXL2017004)supported by the Scientific Research Foundation of Nanjing Forestry University,China+3 种基金Project(202102210132)supported by the Important Project of Science and Technology of Henan Province,ChinaProject(B2019-51)supported by the Scientific Research Foundation of Henan Polytechnic University,ChinaProject(51521003)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of ChinaProject(KQTD2016112515134654)supported by Shenzhen Science and Technology Program,China。
文摘A filter algorithm based on cochlear mechanics and neuron filter mechanism is proposed from the view point of vibration.It helps to solve the problem that the non-linear amplification is rarely considered in studying the auditory filters.A cochlear mechanical transduction model is built to illustrate the audio signals processing procedure in cochlea,and then the neuron filter mechanism is modeled to indirectly obtain the outputs with the cochlear properties of frequency tuning and non-linear amplification.The mathematic description of the proposed algorithm is derived by the two models.The parameter space,the parameter selection rules and the error correction of the proposed algorithm are discussed.The unit impulse responses in the time domain and the frequency domain are simulated and compared to probe into the characteristics of the proposed algorithm.Then a 24-channel filter bank is built based on the proposed algorithm and applied to the enhancements of the audio signals.The experiments and comparisons verify that,the proposed algorithm can effectively divide the audio signals into different frequencies,significantly enhance the high frequency parts,and provide positive impacts on the performance of speech enhancement in different noise environments,especially for the babble noise and the volvo noise.
基金financially supported by the National Natural Science Foundation of China ( 11522219, 11532009)the Projects of International ( Regional) Cooperation and Exchanges of NSFC ( 11761161004)+3 种基金the Natural Science Basic Research Plan in Shaanxi Province of China ( 2017JM1026,2017JM8097)the National Project Cultivating Foundation of Xi’an Medical University ( 2017GJFY23)Young Talent Support Plan of Shaanxi Provincethe China Postdoctoral Science Foundation ( 2018M631141,2018M631173)
文摘Introduction Neurons are situated in a microenvironment composed of various biochemical and biophysical cues,where stretching is thought to have a major impact on neurons.For instance,during a moderate traumatic brain impact,the injury region in axons exhibits significant longitudinal strain;and in a rat model of spinal cord injury,the most severe axonal injury is located in the largest strain region.Stretching may result in microstructural changes in neural tissue and further leading to abnormal electrophysiological function.Hence,it is of great importance to understand the coupled mechanoelectricalbehaviors of neurons under stretching.In spite of significant experimental efforts,the underlying mechanism remains elusive,more works are needed to provide a detailed description of the process that leads to the observed phenomena.Mathematical modeling is a powerful tool that offers a quantitative description of the underlying mechanism of an observed biological phenomenon,including mechanical and electrophysiological behaviors of neurons.Thus,we developed a mechanoelectrical coupling model of neurons under stretching in this study.Mathematical model The mathematical model consists of three submodels,i.e.,the mechanical submodel,the mechanoelectrical coupling submodel and the electrophysiological submodel.The mechanical submodel deals with the relationship between stretching and the deformation of axons,which has specially considered the plastic deformation of axons.The electrophysiological submodel characterizes the feature of neuronal action potential(AP),which is based on the classical H-H model and the cable theory.The mechanoelectrical coupling submodel links the mechanical and electrophysiological submodels through strain-induced equivalent circuit parameter alteration and ion channel injury.Besides,we have discussed a more general deformation condition,where an expanded model coupling the axonal deformation and electrophysiology alteration was explored.As the most essential parameters in an electrophysiological assessment,the amplitude of the AP,the neuronal firing frequency and the electrophysiological signal conduction velocity,which could be affected by stretching,were used as outputs of the model.Results&discussion To understand the mechanoelectrical coupling of neurons under stretching,we developed a mechanoelectrical coupling model.To verify the model,we simulated a slow stretching on an axon following the experimental study in the literature,we observed that as the strain increases,the peak AP declines faster,which is consistent with the experimental data.Moreover,the reduced AP cannot be restored to the original peak,implying that the damage is irreversible.The simulation results also predict that strain induces a more frequent neuronal firing and a faster conduction.In a realistic situation,in addition to stretching,the loading condition is very complicated,which may induce complex axonal deformation(e.g., necking and swelling along the axons).We also simulated such necking deformation impairment and observed that the AP amplitude decreases at the necking region and recovers after that,indicating a blockage of the AP;and the conduction velocity decreases with the increase in deformation degree.Conclusions In this study,we developed a mechanoelectrical coupling model of neurons under stretching with consideration of axonal plastic deformation.With the model,we found that the effect of mechanical loading on electrophysiology mainly manifests as decreased membrane AP amplitude,a more frequent neuronal firing and a faster electrophysiological signal conduction.The model predicts not only stretch-induced injury but also a more gene ral necking deformation case,which may someday be revealed in future by experiments,providing a reference for the prediction and regulation of neuronal function under mechanical loadings.
基金National Natural Science Foundation of China(913322028122100381603084).
文摘Temporal lobe epilepsy(TLE) is a common type of epilepsy and is not well controlled by current treatments.The frequent failure to treat TLE may be due to our lack of precise cellular/circuit mechanisms underlying TLE.The early series of our studies have proved the success of low-frequency stimulation treatment for epilepsy,which was mainly depending on the stimulation target,the stimulation frequency and stimulation time(the therapeutic-window phenomenon).Now,by using optogenetics,viral tracing,multiple-channel EEG analysis,imaging,electrophysiology and pharmacology strategies,we are continued to investigate the circuit mechanism of therapeutic deep brain stimulation,and found that entorhinal principal neurons mediate antiepileptic ″ glutamatergic-GABAergic″ neuronal circuit for brain stimulation treatments of epilepsy.Meanwhile,we are currently focusing on the interplay of inhibitory and excitatory network in the key input/output regions of the hippocampus that related to the generation of in TLE.Specially,we found that depolarized GABAergic signaling in subicular microcircuit mediates generalized seizures in TLE and a direct septal cholinergic circuit attenuates TLE through driving hippocampal somatostatin inhibition.These findings may be of therapeutic interest in understanding the pathological neuronal circuitry in TLE and further the development of novel therapeutic approaches or drug targets.
文摘Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two diseases,and amylin oligomerization in the brain provided a novel risk target for developing AD.Although cumulative studies reported that amylin aggregation induced cytotoxicity in pancreatic beta cells by altering Ca2+homeostasis,fewer studies investigated the effect of amylin on hippocampal neuron.To address this question,it was investigated the effect of amylin on primary cultured rat hippocampal neurons by calcium imaging and whole-cell patch clamp recording in this study,while the results revealed that human amylin(hAmylin) but not rat amylin or pramlintide(hAmylin analgue) produced a rapid increase in intracellular calcium in a dose dependent manner.This effect relied on extracellular calcium and not abolished by amylin receptor antagonist AC187.Additionally,the calcium increase induced by hAmylin was dependent onvoltage-gated Ca2+channels,especially L-type Ca2+channel activation.In whole-cell recording hAmylin could depolarize membrane potential and increase the cell exitability.Moreover,application of transient receptor potential vanilloid(TRPV) antagonist ruthenium red could abolish part of the intracellular calcium increase.Single cell RT-PCR revealed that TRPV4 mRNA expressed in most of the reactive neuron and selective TRPV4 antagonist HC067047 inhibited the intacellular calcium increasing.These results indicated that hAmylin aggregation precipitating on the neuron membrane activated TRPV4 channels and then triggered membrane voltage gated calcium channel opening followed by membrane depolarization,expressing that TRPV4 is a key molecular target for the cytotoxic effect of hAmylin on cultured neurons.
基金National Natural Science Foundation of China(81571269)Science Technology Innovation Fund of Nanjing Medical University (2017NJMUCX008).
文摘OBJECTIVE To study the function of neuronal nitric oxide synthase(nNOS) in the dentate gyrus(DG) in the pathology of epilepsy.METHODS The expression of nNOS in the DG was measured by qPCR and Western blotting in mice 3 and 12 h,1,7,14,and 60 d after treatment with pilocarpine(280 mg·kg-1,ip,one time).We constructed a type of lentiovirus encoding the full length cDNA of nNOS(LV-nNOS-GFP) and injected it and LV-GFP(1 μL) into the DG of the hippocampus 7 d after pilocarpine-induced seizure.The occurrence of epileptic spikes and spontaneous seizure(SRS)were monitored through electroencephalo-graph(EEG) and the protein expression was confirmed by Western blotting.We also constructed a lentioviral vehicle to interfere the expression of nNOS mRNA,which was named as LV-n NOSRNAi-GFP.A volume of 1 μL of LV-nNOS-RNAiGFP or LV-GFP was injected into the DG of the hippocampus 7 d before pilocarpine-induced seizure followed by EEG record and protein detection 2 months later.By EEG,we compared the susceptibility of nNOS knockout and wild-type mice to seizure induction and the development of epilepsy.In addition,we measured the influence of nNOS knockout on the excitability of dentate cells including mEPSC and mIPSC by using patch clamp technique.RESULTS Western blotting and qPCR measurement showed that the mRNA and protein expression of nNOS in the DG was not significantly changed in pilocarpinetreated mice compared with control mice.But the both m RNA and protein expression of nNOS decreased 7,14 and 60 d after treatment with pilocarpine(280 mg·kg-1,ip,one time).With infection of LV-nNOS-GFP in the DG,the decreased level of nNOS was recovered 7 d after seizure induction and the frequency of epileptic spikes and SRS were reversed by nNOS overexpression.We found that nNOS knockout caused a higher susceptive level to seizure induction by pilocarpine.Re-expression of nNOS in the DG of nNOS knockout mice relived the severity of epilepsy.By patch clamp recording,we found that there was no significant difference in the amplitude of mEPSC and mIPSC between nNOS knockout and wild-type mice,but the frequency of mEPSC was increased in nN OS knockout mice.Consistently,knockdown of nNOS by injection of LV-nNOS-RNAi-GFP into the DG caused higher frequency of epileptic spikes and SRS 2 months after pilocarpine-induced seizure.CONCLUSION Neurons expressing nNOS in the DG play an important role in the development of epilepsy.
基金National Natural Science Foundation of China(91332202,81630098,81521062,81671282,81703480).
文摘OBJECTIVE To understand the underlying mechanisms of drug resistant temporal lobe epilepsy(TLE).METHODS In vivo and vitro electrophysiology,optogenetics and chemogenetics were used in a classic multi-drug resistant TLE model.RESULTS Subicular pyramidal neuron activity was not inhibited by the anti-epileptic drug phenytoin in drug resistant rats.This phenomenon was specific to the subiculum,but did not involve surrounding temporal lobe regions.Selective inhibition of subicular pyramidal neurons by both optogenetics and chemogenetics reversed drug resistance.In contrast,selective activation of subicular pyramidal neurons directly induced drug resistance in drug responsive rats.Furthermore,long-term low frequency stimulation at the subiculum,which is clinically feasible,inhibited the activity of subicular pyramidal neurons and reversed drug resistance.CONCLUSION Subicular pyramidal neurons might be a key ″ switch″ mediating drug resistance in TLE and represent a new potential target for more precise treatment of drug resistant TLE.
基金National Natural Science Foundation of China(81560666)Program for Changjiang Scholarsand Innovative Research Team in University, China(IRT_17R113).
文摘OBJECTIVE To explore the effect of icariside Ⅱ(ICS Ⅱ) on oxygen-glucose deprivation and reoxygenation(OGD/R)-induced injury in cerebral cortical neuronal cels.METHODS Primary cerebral cortical neuronal cells were deprived of oxygen and glucose for 2 h to simulate ischemic stroke injury in vitro.The experiment was divided into 8 groups,which were control,control+ICSⅡ 25 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ(6.25,12.5,25 μmol·L^(-1)),OGD/R+3-methyladenine(3-MA) and OGD/R+Rapamycin(Rap).The protective effect of ICS Ⅱ were detected by MTT assay and lactate dehydrogenase(LDH),respectively.Autophagic flux and autophagy related proteins expressions were detected by using adenovirus harboring tf-LC3 and Western blotting,respectively.RESULTS Compared with OGD/R group,the cell viability treated with ICSⅡwas elevated in a concentration-dependent manner,and the leakage rate of LDH was lowed.Moreover,ICSⅡ not only suppressed OGD/R-induced autophagic flux,but also inhibited the increase of LC3-Ⅱ/LC3-Ⅰ ratio and Beclin 1 after OGD/R insulted.CONCLUSION ICS Ⅱ exerts protective effects on OGD/R-induced cerebral cortical neuronal cells through inhibiting excessive autophagy.
基金National Natural Science Foundation of China(31771128)the University of Macao (MYRG2016-00052-FHS+2 种基金MYRG2018-00134-FHS)Science and Technology Development Fund (FDCT)of Macao (FDCT 021/2015/A1016/2016/A1).
文摘Oxidative stress is one of the main causes of neurodegenerative diseases such as Alzheimer disease(AD).Our previous studies have shown that artemisinin,a anti-malaria Chinese medicine,with neuroprotective effect,however,the antioxidative effect of artemisinin and its potential mechanism remain to be elucidated.In the present study,the protective effect and the underlying mechanism of artemisinin against injury of hydrogen peroxide(H_2O_2) in SH-SY5Y and hippocampal neurons were studied.Our results show that artemisinin protected SH-SY5Y and hippocampal neuronal cells from H_2O_2-induced cell death at clinically relevant concentrations in a concentration-dependent manner.Further studies showed that artemisinin significantly reduced cell death caused by H_2O_2 by restoring nuclear morphology,abnormal changes in intracellular ROS,activation of caspase 3,lactate dehydrogenase release and mitochondrial membrane potential.Hoechst staining and flow cytometry showed that artemisinin significantly reduced the apoptosis of SH-SY5Y cells exposed to H_2O_2.Western blotting analysis showed that artemisinin stimulated the phosphorylation and activation of AMP-activated protein kinase(AMPK) in SH-SY5Y cells in a time and concentration-dependent manner,whereas the application of AMPK inhibitor Compound C or decrease in expression of AMPKα with shRNA specific for AMPKα blocked the protective effect of artemisinin.Similar results were obtained in primary cultured hippocampal neurons.Taken together,these results indicate that artemisinin can protect neuronal cells from oxidative damage,at least in part through the activation of AMPK.Because artemisinin is relatively inexpensive and has few side effects,our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.
基金The project supported by National Natural Science Foundation of China(8147319081402910+2 种基金8167341081603090)Jiangsu Specially Appointed Professor
文摘OBJECTIVE Circular RNAs(circRNAs) are highly expressed in the brain and involved in various central nervous system diseases.However,the potential role of circRNAs in ischemic brain injury remains largely unknown.The present study investigated the functional significance of a circular RNA TLK1(circTLK1) in cerebral ischemic injury.METHODS The expression of circTLK1,neurological deficit scores,infarct volume,and long-term neurological deficits were examined in a rodent model of middle cerebral artery occlusion using real-time polymerase chain reaction,triphenyltetrazolium chloride staining,magnetic resonance imaging,GolgiCox staining and behavior tests.Neuronal injury was undertaken in primary cultured cortical neurons challenged by oxygen-glucose deprivation using Western blotting and immunostaining.The interaction between circTLK1 and miR-335-3 p was examined using fluorescence in situ hybridization and affinity isolation assay.The downstream target of miR-335-3 p-TIPARP was determined by luciferase assay and Western blotting assay.RESULTS CircTLK1 levels were significantly increased in brain tissues in a mouse model of focal cerebral ischemia and reperfusion.Knockdown of circTLK1 expression significantly decreased infarct volumes,attenuated neuronal injury,and improved subsequent long-term neurological deficits.Furthermore,circT LK1 functions as an endogenous microRNA-335-3 p sponge to inhibit miR-335-3 p activity,resulting in the inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible polymerase expression and subsequent attenuation of neuronal injury.Clinical studies confirmed the up-regulation of circT LK1 in plasma of patients with ischemic stroke.CONCLUSION CircTLK1 and its underlying mechanisms are involved in ischemic brain injury,suggesting circTLK1 as a potential therapeutic target for ischemic stroke.
基金National Natural Science Foundation of China(8146055681760658).
文摘OBJECTIVE To research the effect of naringenin(NAR) on LPS-induced dopaminergic neurons damage and its potential mechanism.METHODS Rats were randomly divided into the following six groups(n=10):control(0.9% NaCl),NAR alone(100 mg·kg-1),LPS(5 μg),LPS+NAR(50 mg·kg-1) and LPS+NAR(100 mg·kg-1).Rats were received a single LPS unilateral injection into the SN pars compacts,after seven daily intragastric administration of NAR,rats′ behavior was analyzed by rotarod test.Then,the expression of TH,IBA-1 and NLRP3 inflammasome were analyzed by Western blotting and immunofluorescence.In vitro experiments,BV-2 cel s were treated with different doses of NAR,and 1 h later,LPS(1 g·L^(-1)) was added to the medium for 24 h,then collect the culture medium and protein for later experiments.The production of IL-1β and IL-18 in culture medium were tested by ELISA,and the production of NO was detected by Griess reagent.The expression of IBA-1,NLRP3 and p-caspase 1 were detected by Western blotting.MN9 D cells were co-cultured with BV2 cells to mimic the animal experiments.MTT assay was used to analyzed the viability of MN9 D cells,and the expression of TH was detected by Western blotting.RESULTS NAR(100 mg · kg-1) could significantly improve the time of rats on the rotating(116.73 s vs 185.45 s,P<0.05).The result of the pathological analysis also suggested that NAR could decrease the activation of microglia as well as the expression of NLRP3 Inflammasome.In addition,NAR also could suppress the expression of pro-inflammatory factor levels,such as IL-1β(P<0.05),IL-18(P<0.05),and the protection of NAR could be inhibited by siR NA NLRP3.Moreover,an in vitro co-culture system with BV2 and MN9 D cells wasused to find the protection of NAR must via microglia,while there is no effect of NAR were directly added to MN9 D cells.CONCLUSION NAR protection of LPS-induced dopaminergic neurons damage might be through mediating NLRP3 inflammasome.
基金The project supported by National Natural Science Foundation of China(81671188)Zhejiang Provincial Natural Science Foundation of China(LY12H31010)Key Laboratory of Hangzhou City Project(20090233T12)
文摘Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in the pathological progression of cerebral ischemia and neurodegenerative diseases including Parkinson disease(PD).Therefore,it is important to find effective therapeutic targets to attenuate inflammation and delay the progression of brain injury.Cysteinyl leukotrienes(CysLTs) are potent inflammatory mediators synthesized from arachidonic acid by 5-lipoxygenase(5-LOX) in the central nervous system.Two distinct G-protein-coupled receptors,CysLT1 R and CysLT2 R,mediate most of the known CysLTs biological responses.Accumulating evidence has demonstrated that postischemic inflammation and neuronal loss are mediated by 5-LOX and CysLTRs fol owing focal cerebral ischemia.We recently reported that the expression of 5-LOX,CysLT1R and inflammatory vascular cell adhesion molecule-1(VCAM-1) was upregulated in the hippocampus of rats with transient global cerebral ischemia,which was closely associated with delayed neuronal death in the hippocampal CA1 area.5-LOX inhibitor zileuton,CysLT1R antagonist ONO-1078 and montelukast dose-dependently reduced hippocampal CA1 neuronal death and inhibited the increased expression of 5-LOX and VCAM-1.In vitro ischemia-like injury in 5-LOXtransfected PC12 cells,oxygen-glucose deprivation(OGD) induced cell death mediated by5-LOX via ROS/P38 MAPK pathway.The nonselective 5-LOX inhibitor caffeic acid inhibited OGDstimulated activation of 5-LOX and ROS/P38 MAPK signaling and improved neuronal survival.In PD model,high concentrations of rotenone caused directly PC12 neurotoxicity,which was modulated by 5-LOX and abolished by suppression of 5-LOX.It is well known that microglia is major modulators of inflammatory response after brain injury.Overactivated microglia and production of proinflammatory cytokine IL-1β,IL-6 and TNF-α contribute to the neuroinflammation and brain injury.5-LOX,CysLT1R and CysLT2R are involved in microglial activation and resultant neurotoxic responses.It has been found that low concentrations of rotenone can activate 5-LOX and CysLT1R on microglial cells to enhance microglial inflammation and microglia-dependent neuronal death in vitro.5-LOX inhibitor zileuton and CysLT1R antagonist montelukast protected neurons from microglia-dependent rotenone neurotoxicity.Furthermore,lipopolysaccharide(LPS)induced microglial activation and microglial neurotoxicity mediated by CysLT2R in vitro.Both pharmacological blockade(CysLT2R antagonist HAMI3379) and RNA interference(specific short hairpin RNA) of CysLT2 R significantly attenuated LPS-triggered microglial inflammation and subsequent neuronal death.Collectively,the present results indicate the role of 5-LOX and CysLTRs in neuroinflammation and brain injury.Modulation of 5-LOX and CysLTRs may be potential therapeutic approaches for inflammation-related brain disorders such as cerebral ischemia and PD.However,further research is needed to clarify the mechanisms underlying the regulation of neuinflammatory processes by 5-LOX and CysLTRs.
基金The project supported by National Basic Research Program of China(2015CB856401)
文摘OBJECTIVE The high prevalence of sleep disturbance has been found in patients with striatum-related neurodegenerative disorders.In the striatum,there are abundant adenosine A2A receptors(A2ARs)whichhavebeen reported to mediatesleepbehavior for adenosine.We hypothesized that the A2AR-expressing neurons in the striatum are involved in sleep-wake regulation.METHODS We employed a chemogenetic technique,designer receptor exclusively activated by designer drug(DREADD),to specifically and non-invasively manipulate the neuron activity based on the principle of Cre/Lox P recombination,EEG/electromyogram recording for sleep-wake behaviors,the neural tracing approach toselectively visualize the perikarya of A2AR-expressing neurons and their axons by adeno-associated virus(AAV)encoding humanized Renilla green fluorescent(hr GFP)as a tracerin A2AR-Cre mice.In addition,we used immunoelectron microscopy,patch-clamp technique,and optogenetics in A2AR-Cre mice to selectively characterize the synapse and functional connectivity between the A2AR-expressing neurons and the neuron of their downstream targets in vitro.RESULTS The activation of A2AR-expressing neurons in rostral,centromedial and centrolateral striatum increased non-rapid eye movement(non-REM,NREM)sleep,concomitant with a reduction in wakefulness,whereas the activation of A2AR-expressing neurons in caudal striatum didn′t alter sleep-wake profiles at all.Topographical projections in the sagittal section showed that the axons of A2ARexpressing neurons from rostral striatum distributed in the rostral external globuspallidus(GPe)with a discoidal region paralleled to the striato-pallidal border,while the axons of the A2AR-expressing neurons from the central striatum not only distributed in the rostral GPe,but also in the caudal GPe with a similar distributing pattern as did in rostral neurons.However,the axons of A2ARexpressing neurons from caudal striatum just scattered in the caudal GPe.Based on our anatomical findings and patch-clamp technique combining with optogenetics,we found that A2AR neurons in the rostral striatum preferentially formed inhibitory synapses with parvalbumin(PV)-positive neurons in the rostral GPe,while A2AR neurons in the caudal striatum preferentially formed inhibitory synapses with PV-negative neurons in the caudal GPe.CONCLUSION The present results indicated that the A2AR-expressing neurons in rostral and central striatum are involved in sleep-wake regulation,probably via innervating PV-positive neurons in the GPe.
