Rotenone is a lipophilic herbicide extensively utilized in experimental neurodegenerative models because of its capacity to disrupt complex I of the mitochondrial electron transport chain.This inhibition results in re...Rotenone is a lipophilic herbicide extensively utilized in experimental neurodegenerative models because of its capacity to disrupt complex I of the mitochondrial electron transport chain.This inhibition results in reduced ATP synthesis,elevated reactive oxygen species(ROS)formation,and mitochondrial malfunction,which instigates oxidative stress and cellular damage,critical elements in neurodegenerative disorders like Parkinson’s disease(PD),amyotrophic lateral sclerosis(ALS),and Alzheimer’s disease(AD).In addition to causing direct neuronal injury,rotenone significantly contributes to the activation of glial cells,specifically microglia and astrocytes.Activated microglia assumes a proinflammatory(M1)phenotype,distinguished by the secretion of inflammatory cytokines including tumor necrosis factor alpha(TNF-α),interleukin 1 beta(IL-1β),and interleukin 6(IL-6),with the generation of nitric oxide and ROS,which exacerbate the neuronal injury.Astrocytes can intensify neuroinflammation by secreting proinflammatory molecules and impairing their neuroprotective roles.Our hypothesis is that rotenone is posited to elicit a neuroinflammatory response via mitochondrial malfunction,ROS generation,and the activation of proinflammatory pathways in microglia and astrocytes.This mechanism leads to accelerated neuronal impair-ment,promoting neurodegeneration.Comprehending the inflammatory pathways activated by rotenone is crucial for pinpointing therapeutic targets to regulate glial responses and mitigate the advancement of neurodegenerative disorders linked to mitochondrial malfunction and chronic inflammation.This review examines the function of glial cells and critical inflammatory pathways,namely Nuclear factor kappaβ(NF-κB),Phosphoinositide 3-kinase/Protein kinase B/Mammalian target of rapamycin(PI3K/AKT/mTOR),and Wnt/β-catenin signaling pathway in Parkinson’s disease,Alzheimer’s disease,and ALS,emphasizing illness-specific responses and the translational constraints of rotenone-based models.The objective is to consolidate existing understanding regarding the role of rotenone-induced mitochondrial failure in promoting glial activation and neuroinflammation,highlighting the necessity for additional research into these pathways.Despite the prevalent application of rotenone in experimental models,its specific effects on glial-mediated inflammation are inadequately comprehended,necessitating further investigation to guide the formulation of targeted therapeutic strategies.展开更多
Long-term potentiation （LTP） at synapses between primary afferents and spinal dorsal horn neurons induced by noxious electrical stimulation or injury of peripheral nerve is con- sidered to underlie chronic pain [1]....Long-term potentiation （LTP） at synapses between primary afferents and spinal dorsal horn neurons induced by noxious electrical stimulation or injury of peripheral nerve is con- sidered to underlie chronic pain [1]. The mechanisms of the spinal LTP have been intensively investigated, since it was discovered in 1995 [2]. In recent years, spinal application of ATP [3], brain-derived neurotrophic factor （BDNF） [4] and opioid [5] has been shown to induce spinal LTP at C-fiber synapses in the absence of conditioning activation of primary afferents. This is contrary to the general belief that coinci- dent pre- and postsynaptic activity is needed for LTP induction. Recently, Sandkiihler and his co-workers reported in Science that combined activation of microglia and astro- cytes by P2X7 receptor agonist BzATP induces LTP at synapses between afferent C-fibers and spinal lamina I neurons in the absence of presynaptic activation, which is termed gliogenic LTP [6] （Fig. 1C）. To determine the rela- tionship between the gliogenic LTP and high frequency stimulation （HFS）-indueed LTP, they used transverse lum- bar spinal cord slices with long dorsal roots which were separated into halves. Twenty two lamina I neurons that received independent monosynaptic C-fiber inputs from each dorsal root half were recorded. Homosynaptic LTP is recorded in 12 neurons, among them 6 neurons also show heterosynaptic LTP （Fig. 1A）. Interestingly, heterosynaptic LTP is also induced in 5 neurons in which HFS fails to induce homosynaptic LTP （Fig. 1B）.展开更多
Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apopt...Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.展开更多
Diabetes mellitus(DM)and its complications continue to impose a substantial burden on healthcare systems worldwide.Diabetic neuropathy(DN)is one of the most common chronic microvascular and neurodegenerative complicat...Diabetes mellitus(DM)and its complications continue to impose a substantial burden on healthcare systems worldwide.Diabetic neuropathy(DN)is one of the most common chronic microvascular and neurodegenerative complications of DM.It is clinically characterized by allodynia,hyperalgesia,and abnormal or absent nerve fiber sensation,which collectively contribute to poor quality of life,sleep disturbances,depression,and increased mortality.Although several pharmacological agents are available to alleviate DN-related symptoms,their limited long-term efficacy and adverse side effects underscore the urgent need for novel therapeutic approaches.This limitation may be attributed to an incomplete understanding of the underlying mechanisms of DN.Accumulating evidence has highlighted the contribution of glial cells including astrocytes,microglia,and oligodendrocytes to the pathogenesis of DN.However,the specific role of astrocytes remains insufficiently defined.Therefore,this review provides a comprehensive evaluation of current knowledge regarding astrocyte involvement in DN mechanisms,with the goal of clarifying their contribution to disease progression and identifying potential therapeutic targets.展开更多
β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to...β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to be highly related to ischemic stroke,the specific role and underlying mechanistic action ofβ2M are poorly understood.In this study,we established a rat model of focal cerebral ischemia by occlusion of the middle cerebral artery.We found thatβ2M levels in the cerebral spinal fluid,serum,and brain tissue were significantly increased in the acute period but gradually decreased during the recovery period.RNA interference was used to inhibitβ2M expression in the acute period of cerebral stroke.Tissue staining with 2,3,5-triphenyltetrazolium chloride and evaluation of cognitive function using the Morris water maze test demonstrated that decreasedβ2M expression in the ischemic penumbra reduced infarct volume and alleviated cognitive deficits,respectively.Notably,glial cell,caspase-1(p20),and Nod-like receptor pyrin domain containing 3(NLRP3)inflammasome activation as well as production of the inflammatory cytokines interleukin-1β,interleukin-6,and tumor necrosis factor-αwere also effectively inhibited byβ2M silencing.These findings suggest thatβ2M participates in brain injury and cognitive impairment in a rat model of ischemic stroke through activation of neuroinflammation associated with the NLRP3 inflammasome.展开更多
Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, ...Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, that amyloid deposits generate blue autofluorescence(auto-F) has been ignored. Here, we report that visible light-induced auto-F of senile plaques(SPs) was detected and validated with conventional methods. Brain slices from APP/PS1(amyloid precursor protein/presenilin1) transgenic mice were mounted on slides, rinsed,coverslipped and observed for details of the imaging and spectral characteristics of the auto-F of SPs. Then the slices were treated with the above classic methods for comparative validation. We found that the SP auto-F was greatest under blue-violet excitation with a specific emission spectrum, and was much easier, more sensitive, and reliable than the classic methods. Because it does not damage slices, observation of auto-F can be combined with all post-staining techniques in slices and for brain-wide imaging in AD.展开更多
Traumatic brain injury is followed by a cascade of dynamic and complex events occurring at the cellular level. These events include: diffuse axonal injury, neuronal cell death, blood-brain barrier break down, glial ac...Traumatic brain injury is followed by a cascade of dynamic and complex events occurring at the cellular level. These events include: diffuse axonal injury, neuronal cell death, blood-brain barrier break down, glial activation and neuroinflammation, edema, ischemia, vascular injury, energy failure, and peripheral immune cell infiltration. The timing of these events post injury has been linked to injury severity and functional outcome. Extracellular vesicles are membrane bound secretory vesicles that contain markers and cargo pertaining to their cell of origin and can cross the blood-brain barrier. These qualities make extracellular vesicles intriguing candidates for a liquid biopsy into the pathophysiologic changes occurring at the cellular level post traumatic brain injury. Herein, we review the most commonly reported cargo changes in extracellular vesicles from clinical traumatic brain injury samples. We then use knowledge from animal and in vitro models to help infer what these changes may indicate regrading cellular responses post traumatic brain injury. Future research should prioritize labeling extracellular vesicles with markers for distinct cell types across a range of timepoints post traumatic brain injury.展开更多
Ischemic stroke is a devastating disease that affects millions of patients worldwide.Unfortunately,there are no effective medications for mitigating brain injury after ischemic stroke.TRP channels are evolutionally an...Ischemic stroke is a devastating disease that affects millions of patients worldwide.Unfortunately,there are no effective medications for mitigating brain injury after ischemic stroke.TRP channels are evolutionally ancient biosensors that detect external stimuli as well as tissue or cellular injury.To date,many members of the TRP superfamily have been reported to contribute to ischemic brain injury,including the TRPC subfamily(1,3,4,5,6,7),TRPV subfamily(1,2,3,4)and TRPM subfamily(2,4,7).These TRP channels share structural similarities but have distinct channel functions and properties.Their activation during ischemic stroke can be beneficial,detrimental,or even both.In this review,we focus on discussing the interesting features of stroke-related TRP channels and summarizing the underlying cellular and molecular mechanisms responsible for their involvement in ischemic brain injury.展开更多
文摘Rotenone is a lipophilic herbicide extensively utilized in experimental neurodegenerative models because of its capacity to disrupt complex I of the mitochondrial electron transport chain.This inhibition results in reduced ATP synthesis,elevated reactive oxygen species(ROS)formation,and mitochondrial malfunction,which instigates oxidative stress and cellular damage,critical elements in neurodegenerative disorders like Parkinson’s disease(PD),amyotrophic lateral sclerosis(ALS),and Alzheimer’s disease(AD).In addition to causing direct neuronal injury,rotenone significantly contributes to the activation of glial cells,specifically microglia and astrocytes.Activated microglia assumes a proinflammatory(M1)phenotype,distinguished by the secretion of inflammatory cytokines including tumor necrosis factor alpha(TNF-α),interleukin 1 beta(IL-1β),and interleukin 6(IL-6),with the generation of nitric oxide and ROS,which exacerbate the neuronal injury.Astrocytes can intensify neuroinflammation by secreting proinflammatory molecules and impairing their neuroprotective roles.Our hypothesis is that rotenone is posited to elicit a neuroinflammatory response via mitochondrial malfunction,ROS generation,and the activation of proinflammatory pathways in microglia and astrocytes.This mechanism leads to accelerated neuronal impair-ment,promoting neurodegeneration.Comprehending the inflammatory pathways activated by rotenone is crucial for pinpointing therapeutic targets to regulate glial responses and mitigate the advancement of neurodegenerative disorders linked to mitochondrial malfunction and chronic inflammation.This review examines the function of glial cells and critical inflammatory pathways,namely Nuclear factor kappaβ(NF-κB),Phosphoinositide 3-kinase/Protein kinase B/Mammalian target of rapamycin(PI3K/AKT/mTOR),and Wnt/β-catenin signaling pathway in Parkinson’s disease,Alzheimer’s disease,and ALS,emphasizing illness-specific responses and the translational constraints of rotenone-based models.The objective is to consolidate existing understanding regarding the role of rotenone-induced mitochondrial failure in promoting glial activation and neuroinflammation,highlighting the necessity for additional research into these pathways.Despite the prevalent application of rotenone in experimental models,its specific effects on glial-mediated inflammation are inadequately comprehended,necessitating further investigation to guide the formulation of targeted therapeutic strategies.
文摘Long-term potentiation （LTP） at synapses between primary afferents and spinal dorsal horn neurons induced by noxious electrical stimulation or injury of peripheral nerve is con- sidered to underlie chronic pain [1]. The mechanisms of the spinal LTP have been intensively investigated, since it was discovered in 1995 [2]. In recent years, spinal application of ATP [3], brain-derived neurotrophic factor （BDNF） [4] and opioid [5] has been shown to induce spinal LTP at C-fiber synapses in the absence of conditioning activation of primary afferents. This is contrary to the general belief that coinci- dent pre- and postsynaptic activity is needed for LTP induction. Recently, Sandkiihler and his co-workers reported in Science that combined activation of microglia and astro- cytes by P2X7 receptor agonist BzATP induces LTP at synapses between afferent C-fibers and spinal lamina I neurons in the absence of presynaptic activation, which is termed gliogenic LTP [6] （Fig. 1C）. To determine the rela- tionship between the gliogenic LTP and high frequency stimulation （HFS）-indueed LTP, they used transverse lum- bar spinal cord slices with long dorsal roots which were separated into halves. Twenty two lamina I neurons that received independent monosynaptic C-fiber inputs from each dorsal root half were recorded. Homosynaptic LTP is recorded in 12 neurons, among them 6 neurons also show heterosynaptic LTP （Fig. 1A）. Interestingly, heterosynaptic LTP is also induced in 5 neurons in which HFS fails to induce homosynaptic LTP （Fig. 1B）.
基金supported by the National Natural Science Foundation of China,Nos.32271043(to ZW)and 82171047(to YM)the both Science and Technology Major Project of Shanghai,No.2018SHZDZX01 and ZJLabShanghai Center for Brain Science and Brain-Inspired Technology(to ZW)。
文摘Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.
基金Supported by the Fundamental Research Grant Scheme of the Ministry of Higher Education,Malaysia,No.FRGS/1/2024/SKK10/USM/02/8.
文摘Diabetes mellitus(DM)and its complications continue to impose a substantial burden on healthcare systems worldwide.Diabetic neuropathy(DN)is one of the most common chronic microvascular and neurodegenerative complications of DM.It is clinically characterized by allodynia,hyperalgesia,and abnormal or absent nerve fiber sensation,which collectively contribute to poor quality of life,sleep disturbances,depression,and increased mortality.Although several pharmacological agents are available to alleviate DN-related symptoms,their limited long-term efficacy and adverse side effects underscore the urgent need for novel therapeutic approaches.This limitation may be attributed to an incomplete understanding of the underlying mechanisms of DN.Accumulating evidence has highlighted the contribution of glial cells including astrocytes,microglia,and oligodendrocytes to the pathogenesis of DN.However,the specific role of astrocytes remains insufficiently defined.Therefore,this review provides a comprehensive evaluation of current knowledge regarding astrocyte involvement in DN mechanisms,with the goal of clarifying their contribution to disease progression and identifying potential therapeutic targets.
基金supported by the National Natural Science Foundation of China,No.81771337(to RQY).
文摘β2-Microglobulin(β2M),a component of the major histocompatibility complex class I molecule,is associated with aging-related cognitive impairment and Alzheimer’s disease.Although upregulation ofβ2M is considered to be highly related to ischemic stroke,the specific role and underlying mechanistic action ofβ2M are poorly understood.In this study,we established a rat model of focal cerebral ischemia by occlusion of the middle cerebral artery.We found thatβ2M levels in the cerebral spinal fluid,serum,and brain tissue were significantly increased in the acute period but gradually decreased during the recovery period.RNA interference was used to inhibitβ2M expression in the acute period of cerebral stroke.Tissue staining with 2,3,5-triphenyltetrazolium chloride and evaluation of cognitive function using the Morris water maze test demonstrated that decreasedβ2M expression in the ischemic penumbra reduced infarct volume and alleviated cognitive deficits,respectively.Notably,glial cell,caspase-1(p20),and Nod-like receptor pyrin domain containing 3(NLRP3)inflammasome activation as well as production of the inflammatory cytokines interleukin-1β,interleukin-6,and tumor necrosis factor-αwere also effectively inhibited byβ2M silencing.These findings suggest thatβ2M participates in brain injury and cognitive impairment in a rat model of ischemic stroke through activation of neuroinflammation associated with the NLRP3 inflammasome.
基金supported by the National Natural Science Foundation of China (31771156 and 31400945)
文摘Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, that amyloid deposits generate blue autofluorescence(auto-F) has been ignored. Here, we report that visible light-induced auto-F of senile plaques(SPs) was detected and validated with conventional methods. Brain slices from APP/PS1(amyloid precursor protein/presenilin1) transgenic mice were mounted on slides, rinsed,coverslipped and observed for details of the imaging and spectral characteristics of the auto-F of SPs. Then the slices were treated with the above classic methods for comparative validation. We found that the SP auto-F was greatest under blue-violet excitation with a specific emission spectrum, and was much easier, more sensitive, and reliable than the classic methods. Because it does not damage slices, observation of auto-F can be combined with all post-staining techniques in slices and for brain-wide imaging in AD.
基金supported by Canadian Institutes for Health Research (CIHR)(to ADR and WW)Ontario Graduate Scholarship (to NOB)+2 种基金Alzheimer's Society of CanadaHeart and Stroke Foundation of Canada,CIHRthe Canadian Consortium for Neurodegeneration and Aging (CCNA)(to SNW)。
文摘Traumatic brain injury is followed by a cascade of dynamic and complex events occurring at the cellular level. These events include: diffuse axonal injury, neuronal cell death, blood-brain barrier break down, glial activation and neuroinflammation, edema, ischemia, vascular injury, energy failure, and peripheral immune cell infiltration. The timing of these events post injury has been linked to injury severity and functional outcome. Extracellular vesicles are membrane bound secretory vesicles that contain markers and cargo pertaining to their cell of origin and can cross the blood-brain barrier. These qualities make extracellular vesicles intriguing candidates for a liquid biopsy into the pathophysiologic changes occurring at the cellular level post traumatic brain injury. Herein, we review the most commonly reported cargo changes in extracellular vesicles from clinical traumatic brain injury samples. We then use knowledge from animal and in vitro models to help infer what these changes may indicate regrading cellular responses post traumatic brain injury. Future research should prioritize labeling extracellular vesicles with markers for distinct cell types across a range of timepoints post traumatic brain injury.
基金partially supported by the National Institute of Health(R01-HL143750 and R01NS131661)American Heart Association(19TPA34890022)to LYthe Connecticut Institute for the Brain and Cognitive Sciences Seed Grant(402194)to PZ.
文摘Ischemic stroke is a devastating disease that affects millions of patients worldwide.Unfortunately,there are no effective medications for mitigating brain injury after ischemic stroke.TRP channels are evolutionally ancient biosensors that detect external stimuli as well as tissue or cellular injury.To date,many members of the TRP superfamily have been reported to contribute to ischemic brain injury,including the TRPC subfamily(1,3,4,5,6,7),TRPV subfamily(1,2,3,4)and TRPM subfamily(2,4,7).These TRP channels share structural similarities but have distinct channel functions and properties.Their activation during ischemic stroke can be beneficial,detrimental,or even both.In this review,we focus on discussing the interesting features of stroke-related TRP channels and summarizing the underlying cellular and molecular mechanisms responsible for their involvement in ischemic brain injury.
