Research progress in astrocyte dysfunction and depression / 中国药理学与毒理学杂志

Most of the current research on depression focuses on neuronal regulation,while the astrocytic mechanism of depression is far from explored.Astrocytes are the most numerous and widely distributed glial cells in the central nervous system.With a complex structural morphology,astrocytes play an important role in a variety of neuropsychiatric disorders by interacting with neuronal synapses,vasculature and other glial cells.Recent studies have shown that astrocytes may be involved in depression by regulating monoamine transmitters,glutamate cycle,synaptic plasticity,energy metabo-lism,and neuroinflammation.This review is intended to inspire new ideas for the treatment of depres-sion and the development of novel drugs based on astrocyte regulation.

Mechanism of Linggui Zhugantang in Promoting Astrocyte Endocytosis and Degradation of Amyloid β / 中国实验方剂学杂志

ObjectiveTo investigate the effects of Linggui Zhugantang （LGZGT）-containing serum on primary astrocytes （AS） induced by β amyloid 1-42 （Aβ1-42） in a rat model of Alzheimer's disease （AD） and explore the phagocytic and degradative effects of LGZGT on Aβ. MethodAn AD model was established by inducing AS with Aβ1-42. The cells were divided into normal group， model group， LGZGT low-， medium-， and high-dose （LGZGT-L， LGZGT-M， and LGZGT-H） groups， and donepezil hydrochloride group. The model group was treated with Aβ1-42 at a final concentration of 10 μmol∙L-1. The LGZGT-L， LGZGT-M， and LGZGT-H groups were treated with 10% serum containing LGZGT on the basis of the model group. Cell viability was assessed using a cell counting kit-8 （CCK-8）， lactate dehydrogenase （LDH） activity was measured using an LDH assay kit， and cell morphology was observed using an inverted microscope. The expression of Aβ-related degradation enzymes insulin-degrading enzyme （IDE） and cathepsin D （CTSD） was detected using Western blot， and the fluorescence intensity of cathepsin B （CTSB） was measured using immunofluorescence. The content of Aβ1-42 in cells was determined using an enzyme-linked immunosorbent assay （ELISA）. ResultCompared with the normal group， the viability of AS in all groups decreased， and Aβ1-42 at different concentrations had inhibitory effects on AS proliferation. After administration， compared with the normal group， the cell survival rate of the model group decreased significantly （P<0.05）. Compared with the model group， the cell survival rates of the LGZGT-H group and donepezil hydrochloride group increased significantly （P<0.05）. The LDH activity of cells in the model group was significantly increased compared with that in the normal group （P<0.05）， and cell bodies were swollen and enlarged with increased protrusions and elongation， suggesting more obvious cell damage. Compared with the model group， the LDH activity of cells in the donepezil hydrochloride， LGZGT-L， LGZGT-M， and LGZGT-H groups decreased significantly （P<0.05）. After administration， the cell swelling in the LGZGT-M， LGZGT-H， and donepezil hydrochloride groups improved， cell protrusions shortened， and cell clustering decreased. Compared with the normal group， the expression of IDE and CTSD in the model group decreased significantly （P<0.05）. Compared with the model group， the expression of IDE increased significantly in the LGZGT-M and LGZGT-H groups （P<0.05）. Compared with the model group， the expression of CTSD increased significantly in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups （P<0.05）. The average fluorescence intensity of CTSB in the model group was significantly lower than that in the normal group （P<0.05）. Compared with the model group， the average fluorescence intensity of CTSD in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups increased significantly （P<0.05）. The intracellular content of Aβ1-42 in cells in the model group was significantly higher than that in the normal group （P<0.05）. After administration， compared with the model group， the intracellular content of Aβ1-42 in cells in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups decreased significantly （P<0.05）， and LGZGT-containing serum reduced Aβ1-42 in a dose-dependent manner （P<0.05）. ConclusionLGZGT has a protective effect on Aβ1-42-induced AS and can promote the degradation of Aβ. Its mechanism may be related to reducing Aβ toxicity， enhancing cell viability， promoting the expression of IDE， CTSD， and CTSB， and restoring lysosomal function.

Effects of Aβ receptor PirB on mouse astrocyte proliferation and reactive astrogliosis / 解放军医学杂志

Objective To observe the effects of amyloid-β(Aβ)receptor PirB on mouse astrocyte proliferation and reactive astrogliosis in vitro.Methods Mouse primary astrocytes were cultured,and divided into control group,Aβ group,Aβ+0.2 μmol/L PEP group,Aβ+0.4 μmol/L PEP group,Aβ+Fluspirilene group,Aβ+GFP-LV group,and Aβ+mPirB-LV group.The mouse astrocytes were treated with soluble PirB extracellular peptide PEP or PirB inhibitor Fluspirilene,respectively,to inhibit endogenous PirB receptor,or overexpressed PirB gene via lentivirus transfection and then treated with Aβ1-42 oligomers.The proliferation of astrocytes was observed by RTCA and EdU methods,and the mRNA expression levels of S-100 calcium-binding protein B(S-100β),Vimentin,Nestin and amyloid precursor protein(APP)associated with reactive astrogliosis of astrocytes were observed by real-time PCR,and the expression level of glial fibrillary acid protein(GFAP)was detected by Western-blotting.Results The results of RTCA monitoring showed that normalized cell index(NCI)values of each group decreased sharply after treatment,and then increased gradually and tended to be stable.The results of EdU staining showed that the proliferative activity of astrocytes was significantly enhanced in the Aβ group(P<0.05)compared with control group;Compared with Aβ group,cell proliferation activity in Aβ + 0.2 μmol/L PEP group,Aβ+0.4 μmol/L PEP group and Aβ+Fluspirilene group were significantly decreased(P<0.01 or P<0.001).The results of real-time PCR showed that compared with control group,mRNA expressions of GFAP,S-100β,Vimentin,Nestin,APP and PirB in Aβ group were significantly increased(P<0.05);Compared with Aβ group,mRNA expressions of GFAP,S-100β,Vimentin,Nestin,APP and PirB in Aβ+0.4 μmol/L PEP group were significantly decreased(P<0.01);Compared with Aβ+GFP-LV group,mRNA expressions of GFAP,S-100β,Vimentin,Nestin,APP and PirB in Aβ +mPirB-LV group were significantly increased(P<0.05).The results of Western blotting showed that compared with control group,the expression of GFAP in Aβ group was significantly increased(P<0.05);Compared with Aβ group,the expression of GFAP in Aβ+0.4 μmol/L PEP group was significantly decreased(P<0.05).Conclusions PirB is an upstream molecule which could regulate astrocyte proliferation and reactive astrogliosis,and inhibiting PirB receptor in astrocytes may be a potential treatment for Alzheimer's disease.

Deubiquitinase Mysm1 regulates differentiation of neural stem cells into astrocytes by regulating expressions of glial fibrillary acidic protein / 军事医学

Objective To investigate the effect of Mysm1 on the differentiation of neural stem cells(NSCs)into astrocytes and the possible mechanism.Methods NSCs were prepared from E12.5 cortices of wild-type C57BL/6 mice,cultured in vitro and induced to differentiate into astrocytes.Immunofluorescence staining,real-time quantitative PCR and Western blot assay were used to detect the expressions of Mysm1 during the differentiation of NSCs into astrocytes in vitro.Lentivirus was used to knock down Mysm1 expressions in NSCs before real-time quantitative PCR and Western blot assay were used to detect the knockdown efficiency.Immunofluorescence staining and Western blot assay were used to compare the differentiation of NSCs into astrocytes before and after Mysm1 knockdown in vitro.Transcriptomics was adopted to detect the differential gene after knockdown of Mysm1 in NSCs in vitro.Western blot assay was used to verify the changes of proteins associated with the differential gene.Cut-Tag was used to detect the enrichment of Mysm1 in the promoter region of glial fibrillary acidic protein(GFAP)genes during the differentiation of NSCs into astrocytes in vitro.After overexpression of GFAP following knockdown of Mysm1,immunofluorescence staining and Western blot assay were used to compare the differentiation of NSCs into astrocytes before and after overexpression in vitro.Results The expression of Mysm1 was gradually increased when NSCs were induced to differentiate into astrocytes in vitro.Mysm1 knockdown inhibited the differentiation of NSCs into astrocytes in vitro.Mysm1 affected the differentiation of NSCs into astrocytes by regulating the expression of GFAP.Overexpression of GFAP after Mysm1 knockdown partially rescued the ability of NSCs to differentiate into astrocytes.Conclusion Mysm1 regulates the differentiation of NSCs into astrocytes by epigenetically controlling GFAP transcription.

Histamine 1 receptor agonist inhibits LPS-induced immune responses in astrocytes via Akt/NF-KB signaling pathway / 中国药理学通报

Aim To investigate the effect of histamine H, receptor (HjR) on the immune responses in astrocytes induced by lipopolysaccharide (LPS) and the regulatory mechanism of its signaling pathway. Methods LPS was used to establish an in vitro astrocyte inflammation model. Rat primary astrocytes were divided into the control group, LPS group, LPS + Hj R agonist group (2-pyridylethlamine, Pyri), and HjR agonist group. Astrocytes were treated with Pyri 100 p,mol • L~ for 1 h, then stimulated with LPS at 100 p,g • L~ for 24 h. Cell viability was measured using the CCK-8 assay. The expression of GFAP and HjR was detected by immunofluorescence. Glial morphological changes were observed under a microscope. The levels of proinflammatory mediators (TNF-a and IL-6) were detected by ELISA. The protein expressions of p-Akt, Akt, p-NF-KB p65, and NF-KB p65 were detected by Western blot. Results Compared with the control group, more activated astrocytes with fewer cell processes and branches were observed in the LPS group. Besides, LPS enhanced the GFAP expression level, reduced the H,R expression level and stimulated the production of TNF-a and IL-6 from astrocytes. Pre treatment with Pyri for 1 h ameliorated the glial morphological changes stimulated by LPS, inhibited LPS-induced upregulation of GFAP level and the inflammatory factors secretion. In addition, LPS stimulated astrocytes showed a higher phosphorylation of Akt and NF-KB p65, which was also ameliorated by Pyri. Conclusions H, R agonist can inhibit LPS-induced astrocyte activation and inflammatory factor secretion, and the Akt/NF-KB signaling pathway may be an important pathway for the involvement of H,R in immune regulation.

Research progress of RNA m6A methylation in post-stroke cognitive impairment / 天津医药

Post-stroke cognitive impairment(PSCI)is mainly manifested as learning and memory disorders.Highly enriched RNA m6A methylation modification in mammalian brain is involved in glial cell-mediated neuroinflammation.Given that neuroinflammation is the main mechanism for neural damage and spatial and memory impairment of PSCI,it is speculated that RNA m6A methylation modification can regulate the inflammatory response of glial cells after stroke to improve PSCI.This review summarizes and analyzes the role of RNA m6A methylation modification in the development of PSCI and analyzes its detailed mechanism of regulating glial cell-mediated inflammation,which will provide reference for researchers in this field.

Control of astrocytic Ca2+ signaling by nitric oxide-dependent S-nitrosylation of Ca2+ homeostasis modulator 1 channels

Background Astrocytes Ca2+ signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca2+ signals in astrocytes. Importantly, astrocytes express the Ca2+-dependent nitric oxide (NO)-synthe-tizing enzymes eNOS and nNOS, which might contribute to the Ca2+ signals by triggering Ca2+ influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca2+ homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca2+ signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex. Results Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca2+]i and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptordependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca2+ signaling. Conclusions Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca2+ signaling.

La alteración hipotalámica en la obesidad: neuroinflamación y disfunción metabólica / The hypotalamic disturbances during obesity: neuroinflammation and metabolic dysfunction

Resumen La obesidad es considerada actualmente como un problema de salud pública global y se caracteriza por la hipertrofia e hiperplasia del tejido adiposo debido a la ingesta hipercalórica y la falta de actividad física, disfunción metabólica, inflamación sistémica crónica de bajo grado y gradualmente neuroinflamación hipotalámica. El tejido adiposo actúa como un órgano endocrino secretando adipocinas y citocinas que actúan como reguladores del metabolismo. Sin embargo, la presencia de niveles elevados de ácidos grasos libres y de moléculas inflamatorias derivadas de los adipocitos, pueden alterar la respuesta inmunitaria sistémica, generando inflamación crónica, comprometiendo la integridad de la barrera hematoencefálica y estimulando la respuesta de la glía, especialmente en regiones específicas del hipotálamo, centro de regulación de la homeostasis energética. Las células gliales hipotalámicas son importantes en la transmisión de señales inflamatorias relacionadas con la dieta, pueden modular la actividad neuronal, responder a las señales inmunológicas periféricas e iniciar una respuesta inflamatoria local y gliosis. Esta revisión se enfoca en la descripción general de la disfunción metabólica asociada a la obesidad y su participación en la alteración de la regulación hipotalámica, provocando neuroinflamación y modificaciones en la conducta alimentaria.

Abstract Nowadays, obesity is considered a worldwide rising health problem and is characterized by adipose tissue hypertrophy and hyperplasia due to hypercaloric intake and lack of physical activity, promoting the development of metabolic dysfunction, low-grade systemic chronic inflammation, and gradually hypothalamic neuroinflammation. Adipose tissue acts as an endocrine organ secreting adipokines and cytokines around peripheral organs, functioning as a master metabolism regulator. However, high levels of adipocyte-derived free fatty acids and inflammatory molecules promote impairments in systemic immune response, generate chronic inflammation, disrupt the blood-brain barrier, and stimulate glia, specifically in some hypothalamic regions, the master regulators of energetic homeostasis. Hypothalamic glial cells are essential in diet-related inflammatory signals transmission and can modulate neuronal activity, also respond to peripheral inflammatory signals and begin local inflammatory response and gliosis. This review aims to analyze obesity-related metabolic dysfunction and how it participates in the hypothalamic regulation impairments due to neuroinflammation and impairment in food intake behavior.

New role of astrocytes in neuroprotective mechanisms after ischemic stroke / Novo papel dos astrócitos nos mecanismos neuroprotetores após acidente vascular cerebral isquêmico

Abstract Astrocytes are the most abundant cell subtypes in the central nervous system. Previous studies believed that astrocytes are supporting cells in the brain, which only provide nutrients for neurons. However, recent studies have found that astrocytes have more crucial and complex functions in the brain, such as neurogenesis, phagocytosis, and ischemic tolerance. After an ischemic stroke, the activated astrocytes can exert neuroprotective or neurotoxic effects through a variety of pathways. In this review, we will discuss the neuroprotective mechanisms of astrocytes in cerebral ischemia, and mainly focus on reactive astrocytosis or glial scar, neurogenesis, phagocytosis, and cerebral ischemic tolerance, for providing new strategies for the clinical treatment of stroke.

Resumo Os astrócitos são os subtipos de células mais abundantes no sistema nervoso central. Estudos anteriores acreditavam que os astrócitos são células de suporte no cérebro, que apenas fornecem nutrientes para os neurônios. No entanto, estudos recentes descobriram que os astrócitos têm funções mais cruciais e complexas no cérebro, como neurogênese, fagocitose e tolerância isquêmica. Após um acidente vascular cerebral isquêmico, os astrócitos ativados podem exercer efeitos neuroprotetores ou neurotóxicos através de uma variedade de vias. Nesta revisão, discutiremos os mecanismos neuroprotetores dos astrócitos na isquemia cerebral, e focaremos principalmente na astrocitose reativa ou cicatriz glial, neurogênese, fagocitose e tolerância isquêmica cerebral, para fornecer novas estratégias para o tratamento clínico do acidente vascular cerebral.

Sistema glinfático: aspectos anatómicos, fisiológicos e implicaciones clínicas / Glymphatic system: Anatomo-physiological principles and their clinical implications

Introducción: El sistema glinfático comprende el conjunto de rutas perivasculares tanto arteriales como venosas que se encuentran en estrecha asociación con células astrogliales y que permiten la interacción entre el líquido cefalorraquídeo (LCR) y el líquido intersticial cerebral (LIC), para llevar a cabo procesos como la depuración de los metabolitos de desecho celular, o la distribución de nutrientes, así como contribuir al metabolismo cerebral local, la transmisión de volumen y la señalización paracrina cerebral. Contenidos: Este artículo busca profundizar en los conceptos anatómicos y fisiológicos, hasta el momento descritos, sobre este sistema macroscópico de transporte. Se realiza una búsqueda bibliográfica de revisiones y estudios experimentales sobre la anatomía, la fisiología y las implicaciones fisiopatológicas del sistema glinfático. Conclusiones: La identificación anatómica y funcional del sistema glinfático ha ampliado el conocimiento sobre la regulación del metabolismo cerebral en cuanto a distribución de nutrientes y cascadas de señalización celular. Al establecer una interacción entre el espacio subaracnoideo subyacente y el espacio intersticial cerebral, el sistema glinfático surge como uno de los mecanismos protagonistas de la homeostasis cerebral. La disfunción de esta vía hace parte de los mecanismos fisiopatológicos de múltiples trastornos neurológicos, ya sea por la acumulación de macromoléculas, como ocurre en la enfermedad de Alzheimer, o por la reducción del drenaje de sustancias químicas y citocinas proinflamatorias en patologías como la migraña o el trauma craneoencefálico.

Introduction: The glympathic system comprises the set of perivascular routes, arterials or venous, that are found in close relationship with astroglial cells and allow interaction between the cerebrospinal fluid (CSF) and the interstitial brain fluid (ISF), to carry processes like cell-wasting metabolites depuration, nutrients distribution, as well as make a contribution in the local brain metabolism, volumen transmition and brain paracrine signaling. Contents: This article seeks to deepen in the anatomical and physiological concepts, so far described, about this macroscopic transport system. A bibliographic search of reviews and experimental studies on the anatomy, physiology and pathophysiological implications of the glymphatic system is carried out. Conclusions: Anatomical and functional identification of glympathic system has broaden the knowledge about regulation of brain metabolism on the nutrients distribution and cell signaling cascades. When setting an interaction between the subarachnoid space and the brain interstitial space, the glymphatic system arise as one of the leading mechanisms of brain homeostasis. Disfunction of this pathway makes part of the patophysiological mechanisms of multiple neurological disease, either be by collection of macromolecules as in Alzheimer's disease, or by the reduction of inflammatory cytokines and chemical substances drainage as in migraine or traumatic brain injury (TBI).

Mechanism of Dihuang Yinzi in Improving Astrocyte Injury and Glycolysis in AD Mice via PI3K/Akt Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Dihuang Yinzi in improving astrocyte injury and glycolysis in Alzheimer's disease （AD） mice via regulating the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway， thereby improving the cognitive function of AD mice. MethodForty male APP/PS1 transgenic mice aged four months were randomly divided into a model group and a model + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. Forty C57BL/6J mice with the same background and same age were randomly divided into a control group and a control + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. The mice in the control + Dihuang Yinzi group and the model + Dihuang Yinzi group were administered with Dihuang Yinzi by gavage， and those in the control group and the model group received an equal volume of sterilized normal saline， once a day for 150 days. Morris water maze test was performed to test the ability of navigation and space exploration of mice. The protein expression of p-PI3K， PI3K， p-Akt， Akt， phosphofructokinase-1 （PFK-1）， and aldehyde dehydrogenase 3 family member B2 （ALDH3B2） in mouse brain tissues was measured by Western blot. An immunofluorescence assay was performed to detect astrocyte morphology and the expression level of ALDH3B2. ResultAs compared with the control group， the model group showed prolonged escape latency during the 2nd to 5th days of the location-based navigation （P<0.05， P<0.01）， reduced number of times crossing the target area of the platform， shortened residence time in the target quadrant （P<0.05， P<0.01）， prolonged residence time in the opposite quadrant （P<0.05）， increased surface area of the cell body and total length of cell protrusions of astrocytes （P<0.05， P<0.01）， and down-regulated protein expression of p-PI3K， p-Akt， ALDH3B2， and PFK-1 （P<0.01）， while the above experimental indexes were not significantly different in the control + Dihuang Yinzi group. Compared with the model group， the model + Dihuang Yinzi group showed shortened escape latency of APP/PS1 mice during the 2nd to 5th days of the location-based navigation （P<0.05， P<0.01）， increased number of times crossing the platform， prolonged target quadrant residence time （P<0.05， P<0.01）， shortened residence time in the opposite quadrant （P<0.05）， reduced surface area of the cell body and total length of cell protrusions of astrocytes （P<0.05）， and up-regulated protein expression of p-PI3K， p-Akt， ALDH3B2， and PFK-1 （P<0.01）. ConclusionDihuang Yinzi can improve the learning and memory ability of AD mice by activating the PI3K/Akt signaling pathway and up-regulating the protein expression of PFK-1 and ALDH3B2 to protect against astrocyte injury in brain tissues and improve glycolysis.

Mechanism of Dihuang Yinzi in Improving Energy Metabolism Disorder and Autophagy Injury of Astrocytes in Brain of AD Mice / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Dihuang Yinzi （DHYZ）in improving astrocyte injury in the brain and regulating energy metabolism and autophagy disorder in Alzheimer's disease （AD） model mice. MethodForty male APP/PS1 transgenic mice aged four months were randomly divided into a model group and a model + DHYZ group （2.5 g·kg-1）， with 20 mice in each group. Forty C57BL/6J mice with the same background and same age were randomly divided into a control group and a control + DHYZ group （2.5 g·kg-1）， with 20 mice in each group. The mice in the control group and the model group were administered with an equal volume of sterilized normal saline by gavage， once a day for 150 days. Novel object recognition test and step-down test were performed to evaluate the learning and memory ability of mice. The expression of glial fibrillary acidic protein （GFAP） in astrocytes was detected by immunofluorescence and Western blot. High-performance liquid chromatography （HPLC） was used to detect adenosine triphosphate （ATP）， adenosine diphosphate （ADP）， and adenosine monophosphate （AMP） in brain tissues of mice， and the data obtained were used to calculate energy charge （EC） levels. The phosphorylation levels of liver kinase B1 （LKB1）， adenosine 5′-monophosphate （AMP）-activated protein kinase （AMPK）， UNC-51-like kinase 1 （ULK1）， and mammalian target of rapamycin （mTOR） and the expression levels of autophagy-related proteins Beclin-1， microtuble-associated protein 1 light chain 3 （LC3）-Ⅱ/LC3-Ⅰ， and p62 in mouse brain were measured by Western blot. ResultCompared with the control group， the model group showed decreased novel object recognition index， shortened retention latency， increased error times in the step-down test， up-regulated protein expression of GFAP， decreased content of ATP， ADP， and EC in brain tissues， elevated AMP ， increased levels of p-AMPK， p-LKB1， and p-mTOR， and protein expression of p62 ， and down-regulated p-ULK1 level and protein expression of Beclin-1 and LC3-Ⅱ/LC3-Ⅰ（P<0.01）， while the above experimental indexes were not significantly different in the control + DHYZ group. Compared with the model group， the model + DHYZ group showed increased novel object recognition index（P<0.05）， prolonged retention latency（P<0.01）， decreased error times（P<0.01） in the step-down test， reduced protein expression of GFAP（P<0.05）， increased content of ATP， ADP， and EC in brain tissues （P<0.05， P<0.01）， decreased AMP content（P<0.05）， reduced p-AMPK， p-LKB1， and p-mTOR levels and protein expression of p62， and up-regulated p-ULK1 level and protein expression of Beclin-1 and LC3-Ⅱ/LC3-Ⅰ（P<0.01）. ConclusionBy protecting astrocytes， DHYZ can improve energy metabolism and autophagy disorder in AD mice to improve the learning and memory ability of model mice.

Mechanism of Dihuang Yinzi in Improving Astrocyte Injury and Regulating Synaptic Structure and Function in AD Mice / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Dihuang Yinzi in improving astrocyte injury and protecting synaptic structure and function in the brain of Alzheimer's disease （AD） mice. MethodForty male APP/PS1 transgenic mice aged four months were randomly divided into a model group and a model + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. Forty C57BL/6J mice with the same background and same age were randomly divided into a control group and a control + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. The mice in the control + Dihuang Yinzi group and the model + Dihuang Yinzi group were administered with Dihuang Yinzi by gavage， and those in the control group and the model group received an equal volume of sterilized normal saline， once a day for 150 days. The learning and memory ability of mice was tested by the light-dark box test and Y-maze spontaneous alternation test. The content of glutamate （Glu） and glutamine （Gln） was measured by liquid chromatography-tandem mass spectrometry （LC-MS）. Long-term potentiation （LTP） assay was used to detect synaptic plasticity in brain tissues. The protein expression levels of excitatory amino acid transporter 2 （EAAT2）， postsynaptic density protein95 （PSD95）， and synaptophysin （SYN） in brain tissues were measured by Western blot. Immunofluorescence was used to assess the localization and expression of EAAT2. Colorimetry was performed to detect Na+-K+ ATPase activity in mouse brain tissues. ResultAs compared with the control group， the model group showed shortened residence latency （P<0.01）， increased number of errors （P<0.01） in the light-dark box test， reduced spontaneous alternation behaviors （P<0.01）， no significant difference in the total number of arm entries in the Y-maze spontaneous alternation test， down-regulated expression of EAAT2， PSD95， and SYN （P<0.01）， blunted activity of Na+-K+ ATPase （P<0.01）， up-regulated Glu level （P<0.01）， down-regulated Gln level （P<0.01）， and reduced relative population spike （PS） amplitude and the slope of excitatory postsynaptic potential （EPSP） （P<0.05， P<0.01）， while the above experimental indexes were not significantly different in the control + Dihuang Yinzi group. Compared with the model group， the model + Dihuang Yinzi group displayed prolonged residence latency （P<0.05）， decreased number of errors （P<0.01） in the light-dark box test， increased spontaneous alternation behaviors （P<0.01）， no significant difference in the total number of arm entries in the Y-maze spontaneous alternation test， up-regulated expression of EAAT2， PSD95， and SYN （P<0.01）， potentiated activity of Na+-K+ ATPase （P<0.01）， reduced Glu level （P<0.01）， up-regulated Gln level （P<0.01）， and increased PS amplitude and EPSP slope （P<0.01）. ConclusionDihuang Yinzi can improve cognitive dysfunction in AD mice by protecting astrocytes， increasing Glu uptake to reduce its abnormal accumulation， and protecting synaptic structure and function.

Immunological Markers for Central Nervous System Glia / 神经科学通报·英文版

Glial cells in the central nervous system (CNS) are composed of oligodendrocytes, astrocytes and microglia. They contribute more than half of the total cells of the CNS, and are essential for neural development and functioning. Studies on the fate specification, differentiation, and functional diversification of glial cells mainly rely on the proper use of cell- or stage-specific molecular markers. However, as cellular markers often exhibit different specificity and sensitivity, careful consideration must be given prior to their application to avoid possible confusion. Here, we provide an updated overview of a list of well-established immunological markers for the labeling of central glia, and discuss the cell-type specificity and stage dependency of their expression.

Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease / 神经科学通报·英文版

Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.

The Memory Orchestra: Contribution of Astrocytes / 神经科学通报·英文版

For decades, memory research has centered on the role of neurons, which do not function in isolation. However, astrocytes play important roles in regulating neuronal recruitment and function at the local and network levels, forming the basis for information processing as well as memory formation and storage. In this review, we discuss the role of astrocytes in memory functions and their cellular underpinnings at multiple time points. We summarize important breakthroughs and controversies in the field as well as potential avenues to further illuminate the role of astrocytes in memory processes.

Impeding the combination of astrocytic ASCT2 and NLRP3 by talniflumate alleviates neuroinflammation in experimental models of Parkinson's disease

Alanine-serine-cysteine transporter 2 (ASCT2) is reported to participate in the progression of tumors and metabolic diseases. It is also considered to play a crucial role in the glutamate-glutamine shuttle of neuroglial network. However, it remains unclear the involvement of ASCT2 in neurological diseases such as Parkinson's disease (PD). In this study, we demonstrated that high expression of ASCT2 in the plasma samples of PD patients and the midbrain of MPTP mouse models is positively correlated with dyskinesia. We further illustrated that ASCT2 expressed in astrocytes rather than neurons significantly upregulated in response to either MPP+ or LPS/ATP challenge. Genetic ablation of astrocytic ASCT2 alleviated the neuroinflammation and rescued dopaminergic (DA) neuron damage in PD models in vitro and in vivo. Notably, the binding of ASCT2 to NLRP3 aggravates astrocytic inflammasome-triggered neuroinflammation. Then a panel of 2513 FDA-approved drugs were performed via virtual molecular screening based on the target ASCT2 and we succeed in getting the drug talniflumate. It is validated talniflumate impedes astrocytic inflammation and prevents degeneration of DA neurons in PD models. Collectively, these findings reveal the role of astrocytic ASCT2 in the pathogenesis of PD, broaden the therapeutic strategy and provide a promising candidate drug for PD treatment.

Effect of Xiaoxuming Decoction on activation of astrocytes in acute cerebral ischemia/reperfusion injury / 中国中药杂志

This study investigated the effect of Xiaoxuming Decoction(XXMD) on the activation of astrocytes after cerebral ischemia/reperfusion(I/R) injury. The model of cerebral IR injury was established using the middle cerebral artery occlusion method. Fluorocitrate(FC), an inhibitor of astrocyte activation, was applied to inhibit astrocyte activation. Rats were randomly divided into a sham group, a model group, a XXMD group, a XXMD+FC group, and a XXMD+Vehicle group. Neurobehavioral changes at 24 hours after cerebral IR injury, cerebral infarction, histopathological changes observed through HE staining, submicroscopic structure of astrocytes observed through transmission electron microscopy, fluorescence intensity of glial fibrillary acidic protein(GFAP) and thrombospondin 1(TSP1) measured through immunofluorescence, and expression of GFAP and TSP1 in brain tissue measured through Western blot were evaluated in rats from each group. The experimental results showed that neurobehavioral scores and cerebral infarct area significantly increased in the model group. The XXMD group, the XXMD+FC group, and the XXMD+Vehicle group all alleviated neurobehavioral changes in rats. The pathological changes in the brain were evident in the model group, while the XXMD group, the XXMD+FC group, and the XXMD+Vehicle group exhibited milder cerebral IR injury in rats. The submicroscopic structure of astrocytes in the model group showed significant swelling, whereas the XXMD group, the XXMD+FC group, and XXMD+Vehicle group protected the submicroscopic structure of astrocytes. The fluorescence intensity and protein expression of GFAP and TSP1 increased in the model group compared with those in the sham group. However, the XXMD group, the XXMD+FC group, and XXMD+Vehicle group all down-regulated the expression of GFAP and TSP1. The combination of XXMD and FC showed a more pronounced effect. These results indicate that XXMD can improve cerebral IR injury, possibly by inhibiting astrocyte activation and down-regulating the expression of GFAP and TSP1.

Astragalin induces autophagy of astrocytes in anterior cingulate cortex of inflammatory pain mice / 中国病理生理杂志

AIM:To investigate the effects of astragalin(AST)on activation status of astrocytes and the ex-pression level of autophagy-related proteins in the cortex of the anterior cingulate cortex of mice with a complete Freund's adjuvant(CFA)-induced inflammatory pain model.METHODS:Twenty-four 6-month-old male C57BL/6 mice were ran-domly divided into four groups:control group,saline group,CFA model group and CFA+60 mg/kg AST administration group,and six mice in each group.Mice in the AST administration group received 60 mg/kg AST by intraperitoneal injec-tion on a body weight basis for 21 d.The paw withdrawal threshold in each group of mice was evaluated by the von Frey test.The expression levels of autophagy-related factors LC3,p62,ATG12 and beclin-1,and astrocyte activation were de-tected by multiplex immunofluorescence staining in the anterior cingulate cortex of mice in each group.Western blot was used to measure the levels of autophagy-related proteins LC3,p62,ATG12 and beclin-1 in the anterior cingulate cortex of mice in each group.RESULTS:Behavioural tests showed that AST significantly increased mechanical pain thresholds in CFA mice(P＜0.05).The results from multiple immunofluorescent staining showed that AST significantly increased the fluorescence intensity of LC3(P＜0.01),ATG12(P＜0.01)and beclin-1(P＜0.05),attenuated the fluorescence intensi-ty of p62(P＜0.05),and inhibited the activation of astrocytes in the anterior cingulate cortex of CFA mice.Western blot results further confirmed that AST significantly increased the expressions of LC3(P＜0.01),ATG12(P＜0.01),beclin-1(P＜0.01),and decreased the expression of p62(P＜0.05)in the anterior cingulate cortex of CFA mice.CONCLU-SION:AST relieves CFA-induced inflammatory pain of mice,and its analgesic mechanism may be related to the inhibi-tion of activation of cortical astrocytes in the anterior cingulate cortex and the promotion of autophagy in CFA mice.

Role of astrocytic NLRP3 in lateral hypothalamus in anxiety-like behaviors after hemorrhagic shock and resuscitation in mice / 中华麻醉学杂志

Objective:To evaluate the role of astrocytic NOD-like receptor protein 3 (NLRP3) in the lateral hypothalamus (LHA) in anxiety-like behaviors after hemorrhagic shock and resuscitation in mice.Methods:Forty-eight clean-grade male C57BL/6 mice, aged 10 weeks, weighing 25-30 g, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (group C), hemorrhagic shock and resuscitation group (group H), hemorrhagic shock and resuscitation + adeno-associated virus group (group HI), and hemorrhagic shock and resuscitation + control virus group (group HIV). The model of hemorrhagic shock and resuscitation was developed by bleeding and re-transfusion through the femoral vein in H, HI and HIV groups. At 21 days before developing the model, AAV-GfaABC1D-EGFP-Cre was injected into bilateral LHA in group HI, and AAV-GfaABC1D-EGFP was administered as a control in group HIV. Anxiety-like behaviors were evaluated by EPM-maze and bead-burying tests at 14 days after resuscitation. Mice were immediately sacrificed at the end of behavioral tests, and LHA-containing brain tissues were obtained for determination of co-localization of NLRP3 with glial fibrillary acidic protein (GFAP), the fluorescence intensity of Wisteria floribunda agglutinin was measured using immunofluorescent staining to reflect the expression of extracellular matrix in the LHA, and the percentage of cleaved caspase-1/GFAP and IL-18/GFAP positive cells in total cells was calculated. Results:Compared with group C, the number of buried beads and percentage of time of staying at the open arm were significantly decreased, the expression of extracellular matrix in the LHA was down-regulated, and the percentage of cleaved caspase-1/GFAP and IL-18/GFAP positive cells was increased in H, HI and HIV groups, and the co-localization coefficient of NLRP3 and GFAP was significantly decreased in group HI ( P<0.01). Compared with group H, the number of buried particles and percentage of time of staying at the open arm were significantly decreased, the expression of extracellular matrix in the LHA was up-regulated, the co-location coefficient of NLRP3 and GFAP was decreased, the percentage of cleaved caspase-1/GFAP and IL-18/GFAP positive cells was decreased ( P<0.01), and no significant change was found in the parameters mentioned above in group HIV ( P>0.05). Conclusions:Anxiety-like behaviors after hemorrhagic shock and resuscitation is associated with astrocytic NLRP3-induced pyroptosis in the LHA and reduction of extracellular matrix in mice.