Maintaining glutamate homeostasis after hypoxic ischemia is important for synaptic function and neural cell activity,and regulation of glutamate transport between astrocyte and neuron is one of the important modalitie...Maintaining glutamate homeostasis after hypoxic ischemia is important for synaptic function and neural cell activity,and regulation of glutamate transport between astrocyte and neuron is one of the important modalities for reducing glutamate accumulation.However,further research is needed to investigate the dynamic changes in and molecular mechanisms of glutamate transport and the effects of glutamate transport on synapses.The aim of this study was to investigate the regulatory mechanisms underlying Notch pathway mediation of glutamate transport and synaptic plasticity.In this study,Yorkshire neonatal pigs(male,age 3 days,weight 1.0–1.5 kg,n=48)were randomly divided into control(sham surgery group)and five hypoxic ischemia subgroups,according to different recovery time,which were then further subdivided into subgroups treated with dimethyl sulfoxide or a Notch pathway inhibitor(N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester).Once the model was established,immunohistochemistry,immunofluorescence staining,and western blot analyses of Notch pathway-related proteins,synaptophysin,and glutamate transporter were performed.Moreover,synapse microstructure was observed by transmission electron microscopy.At the early stage(6–12 hours after hypoxic ischemia)of hypoxic ischemic injury,expression of glutamate transporter excitatory amino acid transporter-2 and synaptophysin was downregulated,the number of synaptic vesicles was reduced,and synaptic swelling was observed;at 12–24 hours after hypoxic ischemia,the Notch pathway was activated,excitatory amino acid transporter-2 and synaptophysin expression was increased,and the number of synaptic vesicles was slightly increased.Excitatory amino acid transporter-2 and synaptophysin expression decreased after treatment with the Notch pathway inhibitor.This suggests that glutamate transport in astrocytes-neurons after hypoxic ischemic injury is regulated by the Notch pathway and affects vesicle release and synaptic plasticity through the expression of synaptophysin.展开更多
Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous mor...Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous morphological and functional neuronal changes within brain structures associated with cognition and mood,such as the medial prefrontal cortex (mPFC)[1-3],a thorough understanding of how stress induces the core symptoms of depression,such as hopelessness,is still lacking.In an exciting new paper in mice,Yin et al.show that astrocyteneuronal metabolic coupling in the mPFC is critically involved in the stress-induced passive coping response in mice [4].展开更多
Promising therapeutic strategies are being explored to replace or regenerate the neuronal populations that are lost in patients with neurodegenerative disorders.Several research groups have attempted direct reprogramm...Promising therapeutic strategies are being explored to replace or regenerate the neuronal populations that are lost in patients with neurodegenerative disorders.Several research groups have attempted direct reprogramming of astrocytes into neurons by manipulating the expression of polypyrimidine tract-binding protein 1(PTBP1)and claimed putative converted neurons to be functional,which led to improved disease outcomes in animal models of several neurodegenerative disorders.However,a few other studies reported data that contradict these claims,raising doubt about whether PTBP1 suppression truly reprograms astrocytes into neurons and the therapeutic potential of this approach.This review discusses recent advances in regenerative therapeutics including stem cell transplantations for central nervous system disorders,with a particular focus on Parkinson’s and Alzheimer’s diseases.We also provide a perspective on this controversy by considering that astrocyte heterogeneity may be the key to understanding the discrepancy in published studies,and that certain subpopulations of these glial cells may be more readily converted into neurons.展开更多
Research into lactylation modifications across various target organs in both health and disease has gained significant attention.Many essential life processes and the onset of diseases are not only related to protein ...Research into lactylation modifications across various target organs in both health and disease has gained significant attention.Many essential life processes and the onset of diseases are not only related to protein abundance but are also primarily regulated by various post-translational protein modifications.Lactate,once considered merely a byproduct of anaerobic metabolism,has emerged as a crucial energy substrate and signaling molecule involved in both physiological and pathological processes within the nervous system.Furthermore,recent studies have emphasized the significant role of lactate in numerous neurological diseases,including Alzheimer's disease,Parkinson's disease,acute cerebral ischemic stroke,multiple sclerosis,Huntington's disease,and myasthenia gravis.The purpose of this review is to synthesize the current research on lactate and lactylation modifications in neurological diseases,aiming to clarify their mechanisms of action and identify potential therapeutic targets.As such,this work provides an overview of the metabolic regulatory roles of lactate in various disorders,emphasizing its involvement in the regulation of brain function.Additionally,the specific mechanisms of brain lactate metabolism are discussed,suggesting the unique roles of lactate in modulating brain function.As a critical aspect of lactate function,lactylation modifications,including both histone and non-histone lactylation,are explored,with an emphasis on recent advancements in identifying the key regulatory enzymes of such modifications,such as lactylation writers and erasers.The effects and specific mechanisms of abnormal lactate metabolism in diverse neurological diseases are summarized,revealing that lactate acts as a signaling molecule in the regulation of brain functions and that abnormal lactate metabolism is implicated in the progression of various neurological disorders.Future research should focus on further elucidating the molecular mechanisms underlying lactate and lactylation modifications and exploring their potential as therapeutic targets for neurological diseases.展开更多
Lactate,a byproduct of glycolysis,was thought to be a metabolic waste until the discovery of the Warburg effect.Lactate not only functions as a metabolic substrate to provide energy but can also function as a signalin...Lactate,a byproduct of glycolysis,was thought to be a metabolic waste until the discovery of the Warburg effect.Lactate not only functions as a metabolic substrate to provide energy but can also function as a signaling molecule to modulate cellular functions under pathophysiological conditions.The Astrocyte-Neuron Lactate Shuttle has cla rified that lactate plays a pivotal role in the central nervous system.Moreover,protein lactylation highlights the novel role of lactate in regulating transcription,cellular functions,and disease development.This review summarizes the recent advances in lactate metabolism and its role in neurodegenerative diseases,thus providing optimal pers pectives for future research.展开更多
Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure o...Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure on brain and behavior,little is known about the mechanisms that may underlie those effects,and even less about treatments that might reverse them.Recent studies from our laboratory have indicated that AIE produced enduring changes in astrocyte function and synaptic activity in the hippocampal formation,suggesting the possibility of an alteration in astrocyte-neuronal connectivity and function.We utilized astrocyte-specific,membrane restricted viral labeling paired with immunohistochemistry to perform confocal single cell astrocyte imaging,three-dimensional reconstruction,and quantification of astrocyte morphology in hippocampal area CA1 from adult rats after AIE.Additionally,we assessed the colocalization of astrocyte plasma membrane labeling with immunoreactivity for AMPA-(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)glutamate receptor 1,an AMPA receptor subunit and established neuronal marker of excitatory synapses,as a metric of astrocyte-synapse proximity.AIE significantly reduced the colocalization of the astrocyte plasma membrane with synaptic marker puncta in adulthood.This is striking in that it suggests not only an alteration of the physical association of astrocytes with synapses by AIE,but one that lasts into adulthood-well after the termination of alcohol exposure.Perhaps even more notable,the AIE-induced reduction of astrocyte-synapse interaction was reversed by sub-chronic treatment with the clinically used agent,gabapentin(Neurontin),in adulthood.This suggests that a medication in common clinical use may have the potential to reverse some of the enduring effects of adolescent alcohol exposure on brain function.All animal experiments conducted were approved by the Duke University Institutional Animal Care and Use Committee(Protocol Registry Number A159-18-07)on July 27,2018.展开更多
Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant...Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of pri-mary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of pure cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing PCAs with Nrf2 downregulated PCNs that were exposed with and without 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activa-tion of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as meas-ured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis re-vealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with as-trocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events ob-served in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective ef-fect of astrocyte despite dysfunctional Nrf2 system in neurons could be compensated by astrocytic GSH supply.展开更多
The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some ...The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some neural function and communication.The aim of this study was to explore the role of ANLS in the occurrence and maintenance of OIH.After 7 days consecutive morphine injection,a mice OIH model was established and astrocytic pyruvate dehydrogenase kinase 4(PDK4),phosphorylated pyruvate dehydrogenase(p-PDH)and accumulation of L-lactate was elevated in the spinal dorsal horn.Intrathecally administration of inhibitors of PDK,lactate dehydrogenase 5 and monocarboxylate transporters to decrease the supply of L-lactate on neurons was observed to attenuate hypersensitivity behaviors induced by repeated morphine administration and downregulate the expression of markers of central sensitization in the spinal dorsal horns.The astrocyte line and the neuronal line were co-cultured to investigate the mechanisms in vitro.In this study,we demonstrated that morphine-induced hyperalgesia was sustained by lactate overload consequent upon aberrant function of spinal ANLS.In this process,PDK-p-PDH-lactate axis serves a pivotal role,which might therefore be a new target to improve long-term opioid treatment strategy in clinical practice.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81871408 and 81271631(to XMW)National Science Foundation for Young Scientists of China,No.81801658(to YZ)+1 种基金Outstanding Scientific Fund of Shengjing Hospital,No.201402(to XMW)345 Talent Support Project of Shengjing Hospital,No.30B(to YZ)。
文摘Maintaining glutamate homeostasis after hypoxic ischemia is important for synaptic function and neural cell activity,and regulation of glutamate transport between astrocyte and neuron is one of the important modalities for reducing glutamate accumulation.However,further research is needed to investigate the dynamic changes in and molecular mechanisms of glutamate transport and the effects of glutamate transport on synapses.The aim of this study was to investigate the regulatory mechanisms underlying Notch pathway mediation of glutamate transport and synaptic plasticity.In this study,Yorkshire neonatal pigs(male,age 3 days,weight 1.0–1.5 kg,n=48)were randomly divided into control(sham surgery group)and five hypoxic ischemia subgroups,according to different recovery time,which were then further subdivided into subgroups treated with dimethyl sulfoxide or a Notch pathway inhibitor(N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester).Once the model was established,immunohistochemistry,immunofluorescence staining,and western blot analyses of Notch pathway-related proteins,synaptophysin,and glutamate transporter were performed.Moreover,synapse microstructure was observed by transmission electron microscopy.At the early stage(6–12 hours after hypoxic ischemia)of hypoxic ischemic injury,expression of glutamate transporter excitatory amino acid transporter-2 and synaptophysin was downregulated,the number of synaptic vesicles was reduced,and synaptic swelling was observed;at 12–24 hours after hypoxic ischemia,the Notch pathway was activated,excitatory amino acid transporter-2 and synaptophysin expression was increased,and the number of synaptic vesicles was slightly increased.Excitatory amino acid transporter-2 and synaptophysin expression decreased after treatment with the Notch pathway inhibitor.This suggests that glutamate transport in astrocytes-neurons after hypoxic ischemic injury is regulated by the Notch pathway and affects vesicle release and synaptic plasticity through the expression of synaptophysin.
文摘Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous morphological and functional neuronal changes within brain structures associated with cognition and mood,such as the medial prefrontal cortex (mPFC)[1-3],a thorough understanding of how stress induces the core symptoms of depression,such as hopelessness,is still lacking.In an exciting new paper in mice,Yin et al.show that astrocyteneuronal metabolic coupling in the mPFC is critically involved in the stress-induced passive coping response in mice [4].
基金funded by Bryant Stokes Neurological Research Fund,FightMND Drug Development Grant,and Channel 7 Telethon research grant.
文摘Promising therapeutic strategies are being explored to replace or regenerate the neuronal populations that are lost in patients with neurodegenerative disorders.Several research groups have attempted direct reprogramming of astrocytes into neurons by manipulating the expression of polypyrimidine tract-binding protein 1(PTBP1)and claimed putative converted neurons to be functional,which led to improved disease outcomes in animal models of several neurodegenerative disorders.However,a few other studies reported data that contradict these claims,raising doubt about whether PTBP1 suppression truly reprograms astrocytes into neurons and the therapeutic potential of this approach.This review discusses recent advances in regenerative therapeutics including stem cell transplantations for central nervous system disorders,with a particular focus on Parkinson’s and Alzheimer’s diseases.We also provide a perspective on this controversy by considering that astrocyte heterogeneity may be the key to understanding the discrepancy in published studies,and that certain subpopulations of these glial cells may be more readily converted into neurons.
基金supported by Applied Basic Research Joint Fund Project of Yunnan Province,No.202301AY070001-200Middle-aged Academic and Technical Training Project for High-Level Talents,No.202105AC160065+1 种基金Yunnan Clinical Medical Center for Neurological and Cardiovascular Diseases,No.YWLCYXZX2023300077Key Clinical Specialty of Neurology in Yunnan Province,No.300064(all to CL)。
文摘Research into lactylation modifications across various target organs in both health and disease has gained significant attention.Many essential life processes and the onset of diseases are not only related to protein abundance but are also primarily regulated by various post-translational protein modifications.Lactate,once considered merely a byproduct of anaerobic metabolism,has emerged as a crucial energy substrate and signaling molecule involved in both physiological and pathological processes within the nervous system.Furthermore,recent studies have emphasized the significant role of lactate in numerous neurological diseases,including Alzheimer's disease,Parkinson's disease,acute cerebral ischemic stroke,multiple sclerosis,Huntington's disease,and myasthenia gravis.The purpose of this review is to synthesize the current research on lactate and lactylation modifications in neurological diseases,aiming to clarify their mechanisms of action and identify potential therapeutic targets.As such,this work provides an overview of the metabolic regulatory roles of lactate in various disorders,emphasizing its involvement in the regulation of brain function.Additionally,the specific mechanisms of brain lactate metabolism are discussed,suggesting the unique roles of lactate in modulating brain function.As a critical aspect of lactate function,lactylation modifications,including both histone and non-histone lactylation,are explored,with an emphasis on recent advancements in identifying the key regulatory enzymes of such modifications,such as lactylation writers and erasers.The effects and specific mechanisms of abnormal lactate metabolism in diverse neurological diseases are summarized,revealing that lactate acts as a signaling molecule in the regulation of brain functions and that abnormal lactate metabolism is implicated in the progression of various neurological disorders.Future research should focus on further elucidating the molecular mechanisms underlying lactate and lactylation modifications and exploring their potential as therapeutic targets for neurological diseases.
基金supported by the National Natural Science Foundation of China,Nos.82230042 and 81930029(to ZY),U2004201(to FG and RYP)the China Postdoctoral Science Foundation,No.2020M683748(to RYP)。
文摘Lactate,a byproduct of glycolysis,was thought to be a metabolic waste until the discovery of the Warburg effect.Lactate not only functions as a metabolic substrate to provide energy but can also function as a signaling molecule to modulate cellular functions under pathophysiological conditions.The Astrocyte-Neuron Lactate Shuttle has cla rified that lactate plays a pivotal role in the central nervous system.Moreover,protein lactylation highlights the novel role of lactate in regulating transcription,cellular functions,and disease development.This review summarizes the recent advances in lactate metabolism and its role in neurodegenerative diseases,thus providing optimal pers pectives for future research.
基金supported by the National Institute on Alcohol Abuse and Alcoholism(NIAAA)Neurobiology of Adolescent Drinking In Adulthood(NADIA)Grant#2U01AA019925(to HSS)the National Institute on Alcohol Abuse and Alcoholism(NIAAA)R00AA022651(to TAW)the National Institute on Drug Abuse(NIDA)R01DA041455(to KJR)
文摘Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure on brain and behavior,little is known about the mechanisms that may underlie those effects,and even less about treatments that might reverse them.Recent studies from our laboratory have indicated that AIE produced enduring changes in astrocyte function and synaptic activity in the hippocampal formation,suggesting the possibility of an alteration in astrocyte-neuronal connectivity and function.We utilized astrocyte-specific,membrane restricted viral labeling paired with immunohistochemistry to perform confocal single cell astrocyte imaging,three-dimensional reconstruction,and quantification of astrocyte morphology in hippocampal area CA1 from adult rats after AIE.Additionally,we assessed the colocalization of astrocyte plasma membrane labeling with immunoreactivity for AMPA-(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)glutamate receptor 1,an AMPA receptor subunit and established neuronal marker of excitatory synapses,as a metric of astrocyte-synapse proximity.AIE significantly reduced the colocalization of the astrocyte plasma membrane with synaptic marker puncta in adulthood.This is striking in that it suggests not only an alteration of the physical association of astrocytes with synapses by AIE,but one that lasts into adulthood-well after the termination of alcohol exposure.Perhaps even more notable,the AIE-induced reduction of astrocyte-synapse interaction was reversed by sub-chronic treatment with the clinically used agent,gabapentin(Neurontin),in adulthood.This suggests that a medication in common clinical use may have the potential to reverse some of the enduring effects of adolescent alcohol exposure on brain function.All animal experiments conducted were approved by the Duke University Institutional Animal Care and Use Committee(Protocol Registry Number A159-18-07)on July 27,2018.
文摘Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of pri-mary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of pure cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing PCAs with Nrf2 downregulated PCNs that were exposed with and without 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activa-tion of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as meas-ured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis re-vealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with as-trocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events ob-served in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective ef-fect of astrocyte despite dysfunctional Nrf2 system in neurons could be compensated by astrocytic GSH supply.
基金the National Natural Science Foundation of China(82171486)Natural Science Foundation of Shanghai to T.X.(21ZR1448400)+2 种基金the Interdisciplinary Program of Shanghai Jiao Tong University to T.X.(YG2021ZD23)General Science Foundation of Shanghai Sixth People's Hospital to T.X.(YNMS202114)the Young Scholarship Program of the National Natural Science Foundation of China to Xiaqing Ma(82201366)and by Shanghai Sailing Program(21YF1434200).
文摘The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some neural function and communication.The aim of this study was to explore the role of ANLS in the occurrence and maintenance of OIH.After 7 days consecutive morphine injection,a mice OIH model was established and astrocytic pyruvate dehydrogenase kinase 4(PDK4),phosphorylated pyruvate dehydrogenase(p-PDH)and accumulation of L-lactate was elevated in the spinal dorsal horn.Intrathecally administration of inhibitors of PDK,lactate dehydrogenase 5 and monocarboxylate transporters to decrease the supply of L-lactate on neurons was observed to attenuate hypersensitivity behaviors induced by repeated morphine administration and downregulate the expression of markers of central sensitization in the spinal dorsal horns.The astrocyte line and the neuronal line were co-cultured to investigate the mechanisms in vitro.In this study,we demonstrated that morphine-induced hyperalgesia was sustained by lactate overload consequent upon aberrant function of spinal ANLS.In this process,PDK-p-PDH-lactate axis serves a pivotal role,which might therefore be a new target to improve long-term opioid treatment strategy in clinical practice.
