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1.
Neuroscience Bulletin ; (6): 359-372, 2022.
Article in English | WPRIM | ID: wpr-929095

ABSTRACT

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1-TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.


Subject(s)
Animals , Astrocytes/metabolism , DNA Demethylation , Epigenesis, Genetic , GATA1 Transcription Factor/metabolism , Inflammation/metabolism , Oligodeoxyribonucleotides/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Purinergic P2X7/metabolism , Visceral Pain/metabolism
2.
Dement. neuropsychol ; 15(1): 41-50, Jan.-Mar. 2021. tab, graf
Article in English | LILACS | ID: biblio-1286171

ABSTRACT

ABSTRACT. Clinical trials of the effects of physical activity have reported improvements in symptoms and quality of life in patients with Parkinson's disease (PD). Additionally, morphological brain changes after exercising were reported in PD animal models. However, these lifestyle-related changes were not evaluated in postmortem brain tissue. Objective: We aimed to evaluate, by immunohistochemistry, astrocytes, tyrosine hydroxylase (TH) and structural proteins expression (neurofilaments and microtubules — MAP2) changes in postmortem brain samples of individuals with Lewy body pathology. Methods: Braak PD stage≥III samples, classified by neuropathology analysis, from The Biobank for Aging Studies were classified into active (n=12) and non-active (n=12) groups, according to physical activity lifestyle, and paired by age, sex and Braak staging. Substantia nigra and basal ganglia were evaluated. Results: Groups were not different in terms of age or gender and had similar PD neuropathological burden (p=1.00). We observed higher TH expression in the active group in the substantia nigra and the basal ganglia (p=0.04). Astrocytes was greater in the non-active subjects in the midbrain (p=0.03) and basal ganglia (p=0.0004). MAP2 levels were higher for non-active participants in the basal ganglia (p=0.003) and similar between groups in the substantia nigra (p=0.46). Neurofilament levels for non-active participants were higher in the substantia nigra (p=0.006) but not in the basal ganglia (p=0.24). Conclusion: Active lifestyle seems to promote positive effects on brain by maintaining dopamine synthesis and structural protein expression in the nigrostriatal system and decrease astrogliosis in subjects with the same PD neuropathology burden.


RESUMO. Estudos dos efeitos da atividade física relataram melhora nos sintomas e na qualidade de vida de pacientes com doença de Parkinson (DP). Além disso, alterações morfológicas do cérebro após o exercício físico foram relatadas em modelos animais da DP. No entanto, essas mudanças relacionadas ao estilo de vida não foram avaliadas em tecido cerebral post-mortem. Objetivo: Avaliar a expressão de astrócitos, tirosina hidroxilase (TH) e a expressão de proteínas estruturais (neurofilamentos e microtúbulos — MAP2) por imuno-histoquímica, em amostras cerebrais post-mortem de indivíduos com corpos de Lewy. Métodos: Amostras com estágio de Braak para DP≥III, classificação neuropatológica, fornecidas pelo biobanco de estudos do envelhecimento foram classificadas em grupos ativos (n=12) e não ativos (n=12), de acordo com o estilo de vida (atividade física), e pareados por idade, sexo e estadiamento de Braak. Analisou-se a substância negra e gânglios da base. Resultados: Idade, sexo e classificação para DP foram semelhantes (p=1,00). Observou-se maior expressão de TH no grupo ativo (p=0,04). Amostras de não ativos revelaram maior expressão de astrócitos no mesencéfalo (p=0,03) e nos gânglios da base (p=0,0004); MAP2 nos gânglios da base (p=0,003); os níveis de neurofilamentos foram maiores na substância negra (p=0,006). Conclusão: O estilo de vida ativo parece promover efeitos positivos no cérebro, mantendo a síntese de dopamina e a expressão estrutural de proteínas no sistema nigrostriatal e com diminuição da ativação de astrócitos em indivíduos com a mesma classificação neuropatológica para a DP.


Subject(s)
Humans , Parkinson Disease , Lewy Bodies , Autopsy , Aging , Dopamine , Astrocytes , Life Style
3.
Article in Chinese | WPRIM | ID: wpr-905924

ABSTRACT

Objective:To observe and compare the protective effects of Tongqiao Huoxue decoction (TQHX) prepared by three methods against cerebral ischemia-reperfusion injury (CIRI), and to explore its mechanism through the glutamate (Glu) metabolic pathway in astrocytes. Method:The male SD rats of SPF grade were subjected to CIRI model induction by the modified middle cerebral artery occlusion method. The model rats were randomly divided into a model group, a sham operation group, and water-decocted, wine-decocted, and alcohol-extracted TQHX (6.3 g·kg<sup>-1</sup>·d<sup>-1</sup>) groups. The rats were treated correspondingly for 7 days. Those in the sham operation group and the model group were treated with an equal volume of normal saline by gavage. After the final treatment, the neurological function of rats was assessed by the modified neurological severity score (mNSS). Hematoxylin-eosin (HE) staining was used to observe the morphological changes of ischemic brain tissues in rats. High-performance liquid chromatography (HPLC) was used to detect glutamate (Glu) in ischemic brain tissues. The expression of glutamate transporter-1 (GLT-1) and glial fibrillary acidic protein (GFAP) and co-expression of glutamine synthetase (GS) and GFAP in ischemic brain tissues were detected by immunofluorescence assay. Western blot was used to detect the protein expression of GFAP, GLT-1, and GS. Result:Compared with the sham operation group, the model group showed increased mNSS (<italic>P</italic><0.01), large necrosis of cerebral cortex in ischemic brain tissues with disordered cell arrangement, obscure boundary, intracellular edema, and inflammatory infiltration, elevated Glu in ischemic brain tissues (<italic>P</italic><0.01), declining GLT-1-GFAP co-expression and GS-GFAP co-expression (<italic>P</italic><0.01), up-regulated expression of GFAP protein, and reduced protein expression of GLT-1 and GS(<italic>P<</italic>0.05,<italic>P<</italic>0.01). Compared with the model group, the TQHX groups showed decreased mNSS (<italic>P<</italic>0.01), relieved injury in the cerebral cortex and hippocampal nerve cells in ischemic brain tissues, reduced Glu expression(<italic>P<</italic>0.05,<italic>P<</italic>0.01), elevated co-expression of GLT-1 and GFAP (<italic>P<</italic>0.05,<italic>P<</italic>0.01), and up-regulated protein expression of GFAP and GLT-1(<italic>P<</italic>0.05,<italic>P<</italic>0.01). The co-expression of GS and GFAP (<italic>P<</italic>0.05,<italic>P<</italic>0.01)and the expression of GS (<italic>P<</italic>0.01)were increased in the wine-decocted and alcohol-extracted TQHX groups. Compared with the water-decocted TQHX group, the alcohol-extracted group showed increased GLT-1-GFAP and GS-GFAP co-expression(<italic>P<</italic>0.05); the wine-decocted and alcohol-extracted TQHX groups exhibited elevated GS protein expression (<italic>P<</italic>0.05); the alcohol-extracted TQHX group displayed declining Glu content (<italic>P</italic><0.01) and increased protein expression of GFAP and GLT-1 (<italic>P<</italic>0.05, <italic>P<</italic>0.01). Compared with the wine-decocted TQHX group, the alcohol-extracted TQHX group showed increased protein expression of GFAP and GLT-1(<italic>P<</italic>0.05,<italic>P<</italic>0.01). Conclusion:TQHX prepared by three methods can improve neurological deficits in CIRI rats. The effect is presumedly achieved by promoting the further activation of astrocytes, increasing the expression of GLT-1 and GS, promoting the clearance of Glu accumulated in the synaptic cleft by astrocytes through the Glu-glutamine (Gln) circulation, and reducing the excitotoxicity of Glu. The alcohol-extracted TQHX group was superior to the water-decocted and wine-decocted TQHX groups in reducing the content of Glu in ischemic brain tissues, promoting the activation of astrocytes, and enhancing the protein expression of GLT-1 and GS.

4.
Article in Chinese | WPRIM | ID: wpr-921772

ABSTRACT

When ischemia or hemorrhagic stroke occurs, astrocytes are activated by a variety of endogenous regulatory factors to become reactive astrocytes. Subsequently, reactive astrocytes proliferate, differentiate, and migrate around the lesion to form glial scar with the participation of microglia, neuron-glial antigen 2(NG2) glial cells, and extracellular matrix. The role of glial scars at different stages of stroke injury is different. At the middle and late stages of the injury, the secreted chondroitin sulfate proteoglycan and chondroitin sulfate are the main blockers of axon regeneration and nerve function recovery. Targeted regulation of glial scars is an important pathway for neurological rehabilitation after stroke. Chinese medicine has been verified to be effective in stroke rehabilitation in clinical practice, possibly because it has the functions of promoting blood resupply, anti-inflammation, anti-oxidative stress, inhibiting cell proliferation and differentiation, and benign intervention in glial scars. This study reviewed the pathological process and signaling mechanisms of glial scarring after stroke, as well as the intervention of traditional Chinese medicine upon glial scar, aiming to provide theoretical reference and research evidence for developing Chinese medicine against stroke in view of targeting glial scarring.


Subject(s)
Astrocytes , Axons/pathology , Cicatrix/pathology , Gliosis/pathology , Humans , Medicine, Chinese Traditional , Nerve Regeneration , Stroke/drug therapy
5.
Chinese Journal of Anesthesiology ; (12): 1247-1251, 2021.
Article in Chinese | WPRIM | ID: wpr-911352

ABSTRACT

Objective:To evaluate the effect of hydrogen on activation of A1 astrocytes in the hippocampus of mice with sepsis-associated encephalopathy (SAE).Methods:A total of 164 clean-grade healthy male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=41 each) using a random number table method: sham operation group (group Sham), sham operation plus hydrogen group (group Sham+ H 2), group SAE and SAE plus hydrogen group (group SAE+ H 2). The SAE model was established by cecal ligation and perforation.Group Sham+ H 2 and group SAE+ H 2 inhaled 2% hydrogen starting from 1 and 6 h after operation, respectively.Twenty mice in each group were selected to observe the 7-day survival rate after operation.The remaining mice were sacrificed at 12 h after operation, and brain tissues were removed for examination of the pathological changes in hippocampal CA1 region (with a light microscope) and for determination of the apoptosis in neurons (by TUNEL), co-expression of hippocampal glial fibrillary acidic protein (GFAP) and complement C3 (by immunofluorescence staining), expression of A1 astrocyte marker C3 (by Western blot), and contents of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and high-mobility group box 1 protein (HMGB1) (by enzyme-linked immunosorbent assay). The abnormal cell ratio and apoptosis rate were calculated.Six mice in each group were selected at 7 days after operation to perform Y-Maze paradigm. Results:Compared with group Sham, the 7-day survival rate after operation was significantly decreased, the abnormal cell ratio and apoptosis rate of hippocampal neurons were increased, the contents of TNF-α, IL-6 and HMGB1 were increased, the expression of C3 was up-regulated, the number of cells coexpressing GFAP and C3 was increased, the exploration time spent in the novel arm in Y-Maze paradigm was shortened, and the preference index was decreased in group SAE ( P<0.05). Compared with group SAE, the 7-day survival rate after operation was significantly increased, the abnormal cell ratio and apoptosis rate of hippocampal neurons were decreased, the contents of TNF-α, IL-6 and HMGB1 were decreased, the expression of C3 was down-regulated, the number of cells coexpressing GFAP and C3 was decreased, the exploration time spent in the novel arm in Y-Maze paradigm was prolonged, and the preference index was increased in group SAE+ H 2 ( P<0.05). There was no significant difference in each parameter mentioned above between Sham group and Sham+ H 2 group ( P>0.05). Conclusion:The mechanism by which hydrogen improves SAE may be related to inhibiting activation of A1 type astrocytes in mice.

6.
Frontiers of Medicine ; (4): 829-841, 2021.
Article in English | WPRIM | ID: wpr-922513

ABSTRACT

Astrocytes are an abundant subgroup of cells in the central nervous system (CNS) that play a critical role in controlling neuronal circuits involved in emotion, learning, and memory. In clinical cases, multiple chronic brain diseases may cause psychosocial and cognitive impairment, such as depression and Alzheimer's disease (AD). For years, complex pathological conditions driven by depression and AD have been widely perceived to contribute to a high risk of disability, resulting in gradual loss of self-care ability, lower life qualities, and vast burden on human society. Interestingly, correlational research on depression and AD has shown that depression might be a prodrome of progressive degenerative neurological disease. As a kind of multifunctional glial cell in the CNS, astrocytes maintain physiological function via supporting neuronal cells, modulating pathologic niche, and regulating energy metabolism. Mounting evidence has shown that astrocytic dysfunction is involved in the progression of depression and AD. We herein review the current findings on the roles and mechanisms of astrocytes in the development of depression and AD, with an implication of potential therapeutic avenue for these diseases by targeting astrocytes.


Subject(s)
Alzheimer Disease , Astrocytes , Depression , Humans , Neurons
7.
Clin. biomed. res ; 41(2): 157-166, 2021. tab
Article in Portuguese | LILACS | ID: biblio-1341979

ABSTRACT

Introdução: A neuroinflamação associada às células gliais é um elemento importante do processo patológico da doença de Alzheimer (DA). Este estudo apresenta uma revisão dos marcadores gliais quitinase 3-like 1 (YKL-40), do receptor desencadeado expresso nas células mieloides 2 (Triggering receptor expressed on myeloid cells 2 ­ TREM2), da proteína acídica fibrilar glial (GFAP) e da proteína B S100 ligante de cálcio (S100B). Métodos: Nesta revisão são analisados os marcadores gliais YKL-40, TREM2, GFAP e S100B presentes em sangue e/ou líquido cefalorraquidiano (LCR), a partir de estudos publicados até 2020 nos bancos de dados do PubMed, Medline e Periódicos Capes. Resultados: Foram recuperados 233 documentos, dentre os quais foram incluídos 60. Todos os marcadores se encontram aumentados na DA em LCR ­ YKL-40 e TREM2 solúvel (sTREM2), já na fase pré-clínica ­, e em sangue, e estão correlacionados ao declínio cognitivo. No entanto, nenhum dos marcadores analisados apresentou grande potencial para o diagnóstico diferencial. Além da proteína TREM2 solúvel no LCR, no sangue também se pode identificar alteração nos níveis do RNAm de TREM2. GFAP sanguíneo mostra ser o melhor em distinguir controles de pacientes com Alzheimer. Há evidências de um efeito protetivo da ativação glial em reação ao acúmulo amiloide. Conclusão: Os marcadores gliais no geral têm pouca utilidade para o diagnóstico diferencial, mas podem auxiliar no prognóstico e como biomarcadores inespecíficos para doenças neurodegenerativas. (AU)


Introduction: Glial cell-associated neuroinflammation is a driving force for the pathological process of Alzheimer's disease (AD). This study is a systematic review aimed to analyze the following glial markers: chitinase-3-like protein 1 (YKL-40), triggering receptor expressed on myeloid cells 2 (TREM2), glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B). Methods: The PubMed, MEDLINE and CAPES Journals databases were searched for studies published until 2020 that addressed blood and/or cerebrospinal fluid (CSF) levels of YKL-40, TREM2, GFAP and S100B. Results: A total of 233 articles were retrieved, of which 60 were included in this study. All CSF ­ YKL-40 and soluble TREM2 (sTREM2) in preclinical stage ­ and blood biomarker levels were elevated for AD and were correlated to cognitive decline. None of the analyzed biomarkers showed promising results for differential diagnosis. Besides CSF sTREM2 levels, blood TREM2 mRNA levels were also altered in AD. Blood GFAP levels seem to be the best option for distinguishing controls from AD patients.' There is evidence of a protective role of glial activation in amyloid accumulation. Conclusion: Glial markers in general are of little use for differential diagnosis but can assist in prognosis and as nonspecific biomarkers of neurodegenerative diseases. (AU)


Subject(s)
Biomarkers , Neuroglia , Alzheimer Disease/diagnosis , Membrane Glycoproteins , Receptors, Immunologic , S100 Calcium Binding Protein beta Subunit , Chitinase-3-Like Protein 1 , Glial Fibrillary Acidic Protein
8.
Article in Chinese | WPRIM | ID: wpr-861719

ABSTRACT

Hepatic encephalopathy (HE) is a kind of neuropsychiatric syndrome basing on metabolic disorder caused by acute or chronic liver dysfunction or abnormal portosystemic shunt. It is one of the common complications and causes of death in various end-stage liver diseases. The clinical manifestations of patients with HE can vary from personality changes, behavior abnormalities to disturbance of consciousness and coma. The pathogenesis of HE is complex. Theories about ammonia neurotoxicity and alterations in neurotransmitters have been widely accepted. Roles of inflammation, gut microbiota, premature astrocyte senescence, impaired cerebral microcirculation, hemichannel dysfunction, and bile acid also attract much attention. In this review article, the research progress on pathogenesis of HE was briefly summarized.

9.
Article in Chinese | WPRIM | ID: wpr-828115

ABSTRACT

Postoperative cognitive dysfunction (POCD) is one of the most common complications after surgery under general anesthesia and usually manifests as newly presented cognitive impairment. However, the mechanism of POCD is still unclear. In addition to neurons, glial cells including microglia, astrocytes and oligodendrocytes, represent a large cell population in the nervous system. The bi-directional communication between neurons and glia provides basis for neural circuit function. Recent studies suggest that glial dysfunctions may contribute to the occurrence and progress of POCD. In this paper, we review the relevant work on POCD, which may provide new insights into the mechanism and therapeutic strategy for POCD.


Subject(s)
Anesthesia, General , Humans , Microglia , Postoperative Cognitive Complications , Postoperative Complications
10.
Article in Chinese | WPRIM | ID: wpr-847289

ABSTRACT

BACKGROUND: The clinical effect of spinal cord injury is usually unfavorable due to the lack of axon regeneration and the formation of glial scar. Schwann cells, as the support cells for nerve regeneration, have poor migration ability in the central nervous system with abundant astrocytes, which limit its effect on axon regeneration. OBJECTIVE: To explore the effect on the migration of Schwann cells containing superparamagnetic nanoparticles loaded with chondroitinase ABC (ChABC) in the region of astrocytes in the external magnetic field. METHODS: Schwann cells and astrocytes were extracted from sciatic nerves and brachial plexus and cerebral cortex of Sprague-Dawley rats of postnatal day 1 to 3. Cell purity was identified by immunofluorescence staining. The toxicity of superparamagnetic nanoparticles (PEI-SPIONs) to Schwann cells was analyzed by live/dead cell staining. Schwann cells were transfected with PEI-SPIONS in an external magnetic field of 1.4Td for 2 days. The optimal transfection concentration of PEI-SPIONS used was 2 mg/L and the optimal mass ratio of PEI-SPIONS to ChABC was 1:4. Cell migration test was used to evaluate the migration ability of not-treated Schwann cells, PEI-SPIONs/ ChABC transfected Schwann cells, and PEI-SPIONs/ChABC transfected Schwann cells in an external magnetic field. RESULTS AND CONCLUSION: The purity of Schwann cells and astrocytes reached to (91.7±1.2)% and (93.3±2.2)%, respectively. Compared with the Schwann cells group, the number of PEI-SPIONs/ChABC-transfected Schwann cells that entered the region of astrocytes was significantly increased (P < 0.05). Under the external magnetic field, the number of PEI-SPIONs/ChABC-transfected Schwann cells that entered the region of astrocytes and the cell migration distance were significantly increased as compared with the Schwann cells group (P < 0.005). In summary, PEI-SPIONs/ChABC transfection can enhance the ability of Schwann cells to break the glial scar, and increase the fusion of astrocytes. Under the guidance of external magnetic field, the migration ability of Schwann cells is significantly elevated. This method may be a new strategy to promote nerve regeneration after spinal cord injury.

11.
Article in Chinese | WPRIM | ID: wpr-847256

ABSTRACT

BACKGROUND: Astrocyte proliferation is an important morphological change in epilepsy. Proliferated glial cells can produce cytokines, and in turn activates JAK/STAT signal transduction to promote glial cell proliferation, which affects the occurrence and recurrence of epilepsy. Astrocytes and signal transduction pathways interact with each other to play a role in the pathogenesis of epilepsy. OBJECTIVE: To investigate the effect of cannabinoid receptor type 2 (CB2R) on the activation of ERK, p38, and JNK proteins in astrocytes and MAPK pathways in juvenile rats with persistent epilepsy. METHODS: Forty healthy male Sprague-Dawley rats (18-21 days old) were randomly divided into four groups: normal control group, epilepsy model group, CB2R agonist JWH133 group, CB2R antagonist AM630 group. The normal control group was given only normal saline. In the other groups, rats were intraperitoneally injected with lithium chloride and pilocarpine to establish epilepsy models, and different interventions were performed. Twenty-four hours after the onset of epilepsy, brain tissues were taken. Co-expression of GFAP and p-ERK, p-p38, and p-JNK in hippocampal tissue was detected by immunofluorescence. Real-time PCR was used to detect the expression of GFAP mRNA in hippocampal tissue. RESULTS AND CONCLUSION: The co-expression of GFAP/p-ERK and GFAP/p-p38 was significantly higher in the epilepsy model group than the normal control group (P < 0.05), significantly lower in the JWH133 group than the epilepsy model group (P < 0.05), and significantly higher in the AM630 group than the JWH133 group (P < 0.05). The co-expression of GFAP/p-JNK was significantly lower in the epilepsy model group than in normal control group (P < 0.05), significantly higher in the JWH133 group than the epilepsy model group (P < 0.05), and significantly lower in the AM630 group than the JWH133 group (P < 0.05). The mRNA expression of GFAP was significantly decreased in the epilepsy model group compared with the normal control group (P < 0.05), significantly increased in the JWH133 group compared with the epilepsy model group (P < 0.05), and significantly reduced in the AM630 group compared with the JWH133 group (P < 0.05). Therefore, CB2R can regulate the expression of ERK, p38, JNK proteins in the MAPK pathway, thereby affecting astrocytes in the hippocampus of juvenile rats with persistent epilepsy.

12.
Neuroscience Bulletin ; (6): 530-544, 2020.
Article in English | WPRIM | ID: wpr-826998

ABSTRACT

Astrocytes are the most abundant cell type in the central nervous system (CNS). They provide trophic support for neurons, modulate synaptic transmission and plasticity, and contribute to neuronal dysfunction. Many transgenic mouse lines have been generated to obtain astrocyte-specific expression of inducible Cre recombinase for functional studies; however, the expression patterns of inducible Cre recombinase in these lines have not been systematically characterized. We generated a new astrocyte-specific Aldh1l1-CreER knock-in mouse line and compared the expression pattern of Cre recombinase between this and five widely-used transgenic lines (hGfap-CreER from The Jackson Laboratory and The Mutant Mouse Resource and Research Center, Glast-CreER, Cx30-CreER, and Fgfr3-iCreER) by crossing with Ai14 mice, which express tdTomato fluorescence following Cre-mediated recombination. In adult Aldh1l1-CreER:Ai14 transgenic mice, tdTomato was detected throughout the CNS, and five novel morphologically-defined types of astrocyte were described. Among the six evaluated lines, the specificity of Cre-mediated recombination was highest when driven by Aldh1l1 and lowest when driven by hGfap; in the latter mice, co-staining between tdTomato and NeuN was observed in the hippocampus and cortex. Notably, evident leakage was noted in Fgfr3-iCreER mice, and the expression level of tdTomato was low in the thalamus when Cre recombinase expression was driven by Glast and in the capsular part of the central amygdaloid nucleus when driven by Cx30. Furthermore, tdTomato was clearly expressed in peripheral organs in four of the lines. Our results emphasize that the astrocyte-specific CreER transgenic lines used in functional studies should be carefully selected.

13.
Article in Chinese | WPRIM | ID: wpr-861128

ABSTRACT

Diabetes is a common clinical metabolic disease, which can affect cardiovacular, cerebrovascular, eye, kidney and other organs, among which the clinical manifestations of diabetes-associated cognitive decline are not obvious and difficult to diagnose. 18F-FDG PET/CT has the ability to early identify metabolic changes and is widely used to diagnose neurological diseases, also can be used to evaluate abnormal brain glucose metabolism in diabetic patients. Neurons and astrocytes are closely related to brain glucose metabolism, and abnormal changes of cell number, function and metabolic activity may lead to cognitive decline in diabetes. The effects of abnormal changes of neuronal and astrocytes under hyperglycemia on cerebral glucose metabolism were reviewed, and the causes of brain glucose metabolism changed in diabetic were analyzed in this article, in order to provide theoretical basis for diagnosing diabetes-related neurological diseases.

14.
Article in English | WPRIM | ID: wpr-827414

ABSTRACT

OBJECTIVES@#To observe the electrophysiological changes of astrocytes in the process of hyperoxia induced apoptosis and analyze the relationship between electrophysiological characteristics and morphological changes.@*METHODS@#Astrocytes were exposed to 90% hyperoxia for 12-72 h. The electrophysiological characteristics of astrocytes in each group were detected by patch clamp technique, and the morphological characteristics of astrocytes were observed at the same time. Then the same batch of astrocytes were collected, and the expression levels of caspase-1, caspase-3, gasdermin D (GSDMD) and gasdermin E (GSDME) were detected by Western blotting.@*RESULTS@#From 12 h to 72 h after hyperoxia exposure, the inward current was significantly lower than that of the control group (0.05). At each time point, the morphology of cells changed correspondingly. Western blotting showed that the expression of caspase-1 was increased significantly at 24 h and decreased significantly at 72 h after hyperoxia exposure (0.05), but began to decrease at 48 h (<0.05); GSDME increased gradually at 24 h after hyperoxia exposure (<0.05).@*CONCLUSIONS@#Under hyperoxia exposure, the ion channels of astrocytes are damaged, which can maintain the dysfunction of ion homeostasis, activate GSDME, induce the damaged cells to break away from the apoptotic pathway, and mediate the pyroptosis.


Subject(s)
Apoptosis , Astrocytes , Caspase 1 , Humans , Hyperoxia , Intracellular Signaling Peptides and Proteins , Neoplasm Proteins , Phosphate-Binding Proteins , Pyroptosis
15.
Braz. j. med. biol. res ; 53(4): e8604, 2020. graf
Article in English | LILACS | ID: biblio-1100926

ABSTRACT

Maraba virus is a member of the genus Vesiculovirus of the Rhabdoviridae family that was isolated in 1983 from sandflies captured in the municipality of Maraba, state of Pará, Amazônia, Brazil. Despite 30 years having passed since its isolation, little is known about the neuropathology induced by the Maraba virus. Accordingly, in this study the histopathological features, inflammatory glial changes, cytokine concentrations, and nitric oxide activity in the encephalon of adult mice subjected to Maraba virus nostril infection were evaluated. The results showed that 6 days after intranasal inoculation, severe neuropathological-associated disease signs appeared, including edema, necrosis and pyknosis of neurons, generalized congestion of encephalic vessels, and intra- and perivascular meningeal lymphocytic infiltrates in several brain regions. Immunolabeling of viral antigens was observed in almost all central nervous system (CNS) areas and this was associated with intense microglial activation and astrogliosis. Compared to control animals, infected mice showed significant increases in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (INF)-γ, MCP-1, nitric oxide, and encephalic cytokine levels. We suggest that an exacerbated inflammatory response in several regions of the CNS of adult BALB/c mice might be responsible for their deaths.


Subject(s)
Animals , Male , Rabbits , Vesicular Stomatitis/complications , Meningoencephalitis/complications , Brazil , Astrocytes/metabolism , Cytokines/analysis , Vesiculovirus , Microglia/metabolism , Disease Models, Animal , Vesicular Stomatitis/pathology , Flow Cytometry , Meningoencephalitis/pathology , Mice, Inbred BALB C , Nitric Oxide/analysis
16.
Rev. Assoc. Med. Bras. (1992) ; 65(9): 1174-1180, Sept. 2019. graf
Article in English | LILACS | ID: biblio-1041070

ABSTRACT

SUMMARY OBJECTIVE The study aims to explore the relationship between preoperative anxiety and chronic postoperative pain. METHODS A total of forty rats were divided into four groups, control, single-prolonged stress alone, Hysterectomy alone, and SPS+ Hysterectomy. The paw withdrawal mechanical thresholds (PWMT) were examined. qRT-PCR and western blotting assay were performed to detect the GFAP expression in astrocytes isolated from the anterior cingulate cortex (ACC) region. In addition, the long-term potentiation (LTP) in ACC was examined. RESULTS Rats in the SPS group or the Hysterectomy alone group had no significant effect on chronic pain formation, but SPS can significantly induce chronic pain after surgery. Astrocytes were still active, and the LTP was significantly increased three days after modeling in the SPS+Hysterectomy group. CONCLUSIONS anxiety can induce chronic pain by activating astrocytes in the ACC region.


RESUMO OBJETIVO O objetivo deste estudo é explorar a relação entre a ansiedade no pré-operatório e a dor crônica no pós-operatório. MÉTODOS Um total de 40 ratos foram divididos em quatro grupos: controle, estresse prolongado (SPS), histerectomia e SPS + histerectomia. Os limiares de retirada da pata em resposta a estímulo mecânico (PWMT) foram examinados. Ensaios qRT-PCR e imunoenzimáticos (western blotting) foram realizados para detectar a expressão de GFAP em astrócitos isolados da região do córtex cingulado anterior (CCA). Além disso, a potenciação de longa duração (LTP) no CCA também foi examinada. RESULTADOS Os ratos no grupo de estresse prolongado e no grupo de histerectomia não apresentaram nenhum efeito significativo na formação de dor crônica. Porém, o estresse prolongado foi capaz de induzir dor crônica significativamente após a cirurgia. Três dias após o modelo, o grupo de SPS + histerectomia ainda apresentava astrócitos ativos e LTP significativamente maior. CONCLUSÃO A ansiedade pode provocar dor crônica através da ativação de astrócitos na região do CCA.


Subject(s)
Animals , Female , Anxiety/complications , Pain, Postoperative/etiology , Astrocytes/metabolism , Chronic Pain/etiology , Pain, Postoperative/psychology , Stress, Psychological/etiology , Time Factors , Random Allocation , Rats, Sprague-Dawley , Pain Threshold/physiology , Long-Term Potentiation/physiology , Disease Models, Animal , Preoperative Period , Chronic Pain/psychology , Glial Fibrillary Acidic Protein/metabolism , Gyrus Cinguli/metabolism , Hindlimb , Hysterectomy
17.
Arq. neuropsiquiatr ; 77(9): 601-608, Sept. 2019. tab, graf
Article in English | LILACS | ID: biblio-1038743

ABSTRACT

ABSTRACT Objective: Hypothalamic inflammation and glial fibrillary acidic protein (GFAP) overexpression in astrocytes are well described in obese animals, as are some cognitive and memory deficits. As the hippocampus plays important roles in the consolidation of information, this investigation aimed to observe the memory function and the astrocyte expression of GFAP in the hippocampus of rats that received either a hypercaloric or a normocaloric diet. Methods: Adult male Wistar rats received a high-fat (cafeteria) or a standard diet for 60 days. On the 61st day, the rats were submitted to the novel object recognition (NOR) test at three and 24 hours after the first contact with objects, to assess short-term and long-term memory, respectively. Thereafter, the rats were euthanized and their brains were collected for GFAP immunohistochemical investigation in the hippocampus (CA1, CA2, CA3 areas) and hypothalamus (periventricular and arcuate nuclei). Astrocytic reactivity was assessed by morphometry. Different white adipose tissue depots and brown adipose tissue were weighed to calculate the adiposity index. Results: The hypercaloric diet increased body weight gain, adiposity index, white adipose tissue weight (epididymal, subcutaneous and retroperitoneal) and brown adipose tissue weight. Rats fed with the hypercaloric diet showed short-term and long-term memory impairments in the NOR test, as well as increased GFAP expression in astrocytes from all analyzed hypothalamic and hippocampal areas. Conclusion: This astrogliosis suggests that the neuroinflammatory response also occurs in the hippocampus and may be involved in the memory losses observed in obese/overweight animals.


RESUMO Objetivo: A inflamação hipotalâmica e a superexpressão da proteína glial fibrilar ácida (GFAP) em astrócitos são bem descritas em animais obesos, assim como déficits cognitivos e de memória. Como o hipocampo desempenha importante papel na consolidação de informações, esta investigação teve como objetivo observar a função da memória e a expressão astrocitária da GFAP no hipocampo de ratos que receberam dieta hipercalórica ou normocalórica. Métodos: Ratos Wistar machos adultos receberam dieta rica em gordura (cafeteria) ou dieta padrão por 60 dias. No 61º dia, os ratos foram submetidos ao teste de reconhecimento de objetos (NOR) 3 e 24 horas após o primeiro contato com os objetos, para avaliação da memória de curto e de longo prazo, respectivamente. Após, os ratos foram eutanasiados e os encéfalos coletados para pesquisa imuno-histoquímica da expressão astrocitária de GFAP no hipocampo (áreas CA1, CA2 e CA3) e no hipotálamo (núcleos periventricular e arqueado). A reatividade astrocitária foi avaliada por morfometria. Diferentes depósitos de tecido adiposo branco e marrom foram pesados para calcular o índice de adiposidade. Resultados: A dieta hipercalórica aumentou o ganho de peso corporal, o índice de adiposidade, o peso do tecido adiposo branco (epididimal, subcutâneo e retroperitoneal) e marrom. Ratos alimentados com dieta hipercalórica apresentaram prejuízos na memória de curto e longo prazo no teste NOR e aumento da expressão de GFAP em astrócitos de todas as áreas hipotalâmicas e hipocampais analisadas. Conclusão: Esta astrogliose sugere que a resposta neuroinflamatória também ocorre no hipocampo, podendo estar envolvida nas perdas de memória observadas em animais obesos/com sobrepeso.


Subject(s)
Animals , Male , Astrocytes/chemistry , Diet, High-Fat/adverse effects , Glial Fibrillary Acidic Protein/analysis , Hippocampus/cytology , Memory Disorders/etiology , Obesity/complications , Reference Values , Time Factors , Immunohistochemistry , Adipose Tissue/metabolism , Rats, Wistar , Glial Fibrillary Acidic Protein/metabolism , Memory Disorders/metabolism , Obesity/metabolism
18.
China Occupational Medicine ; (6): 15-21, 2019.
Article in Chinese | WPRIM | ID: wpr-881766

ABSTRACT

OBJECTIVE: To investigate the role of N-methyl-D-aspartate receptor(NMDAR)/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA) signaling pathways in regulating 2-chloroethanol-induced aquaporin-4(AQP4) expression in astrocytes(AS). METHODS: i) AS in logarithmic growth phase were treated with 2-chloroethanol at the doses of 0.0, 7.5, 15.0 and 30.0 mmol/L for 12 hours, and the cells were collected for detection. ii) The AS in logarithmic growth phase were divided into blank control group, inhibitor control group, 2-chloroethanol group, and inhibitor intervention group. The inhibitor included dizocilpine(MK-801) and N-(2-[p-bromocinnamylamino-]ethyl)-5-isoquinolinesulfonamide(H89). The blank control group did not receive any treatment. The inhibitor control group was treated with a concentration of 10.0 μmmol/L MK-801 or 15.0 μmmol/L H89. The MK-801 intervention group was pretreated with MK-801 at a concentration of 10.0 μmmol/L for 30 minutes. The H89 intervention group was pretreated with H89 at a concentration of 15.0 μmmol/L for 1 hour. After the intervention, the AS in 2-chloroethanol group and MK-801, H89 intervention group were stimulated with 2-chloroethanol at a dose of 30.0 mmol/L for 12 hours. iii) The AS in each group were collected and used for Western blotting and real-time fluorescence quantitative polymerase chain reaction analysis to detect the protein and mRNA expression of AQP4, NMDAR receptor main subunit(NR1), NMDAR receptor 2 B subunit(NR2 B) and calmodulin dependent protein kinaseⅡ(CaMKⅡ). The Western blotting was adopted to detect the expression of phosphorylase-CaMKⅡ(p-CaMKⅡ) and PKA. Colorimetric method was used to detect the concentration of calcium(Ca~(2+)) in AS. The enzyme-linked adsorption test was used to measure adenylate cyclase(AC) activity and cAMP levels. RESULTS: i) The relative expression of protein and mRNA of AQP4, NR1 and NR2 B, PKA at protein level and CaMKⅡ at mRNA level, and the ratio of p-CaMKⅡ/CaMKⅡ protein, the concentration of Ca~(2+), AC activity and cAMP level in 30.0 mmol/L group were higher then those of 0.0 mmol/L group in AS(P<0.05). The relative protein expression of PKA and the concentration of Ca~(2+) increased with the increase of 2-chloroethanol(P<0.05). ii) The relative protein expression of AQP4 and the concentration of Ca~(2+) in the 2-chloroethanol group were higher than that of the blank control group and MK-801 control group(P<0.05). The relative protein expression of AQP4 and the concentration of Ca~(2+) in MK-801 intervention group were lower than that in 2-chloroethanol group(P<0.05). The relative protein expression of AQP4 and PKA in 2-chloroethanol group were higher than that of the blank control group and H89 control group(P<0.05). The relative protein expression of AQP4 and PKA in H89 intervention group was lower than that in 2-chloroethanol group(P<0.05). CONCLUSION: The 2-chloroethanol timulation induces the expression of AQP4 by activating NMDAR/cAMP/PKA signaling pathway in AS.

19.
Article in Chinese | WPRIM | ID: wpr-807889

ABSTRACT

@#To investigate the effects and mechanism of fibroblast growth factor 21(FGF21)on astrocytes in AD-like lesions, Aβ25-35 was used to induce astrocyte model damaged. Cell model was established by inducing C6 astrocyte cell line and primary astrocyte damage with Aβ25-35. Different concentrations of FGF21 were used to intervene cell injury model induced by Aβ25-35, and cell viabilities were detected by MTT assay. Effects of FGF21 and Aβ25-35 on reactive oxygen species(ROS)levels in C6 cells were tested using DCFH-DA probe and flow cytometry. Western blot was used to assess the effects of FGF21 and Aβ25-35 on the activities of mitogen-activated protein kinases(MAPKs)in C6 cells. The results showed that FGF21 could reduce the damage of C6 cells and primary astrocytes induced by Aβ25-35, down-regulate the abnormal ROS level in C6 cells, and alleviate the abnormal phosphorylation levels of MEK1/2, ERK1/2 and p38 in C6 cells induced by Aβ25-35, suggesting that FGF21 may attenuate Aβ25-35-induced astrocyte damage by regulating ROS pathway and MAPKs signaling pathway.

20.
Article in Chinese | WPRIM | ID: wpr-805859

ABSTRACT

@#This study aims to explore the involvement of c-Jun N-terminal kinase(JNK)-Gap junction regulation in the rat model of bone cancer pain and figure out whether adenosine 5′-monophosphate(AMP)-activated protein kinase(AMPK )activator metformin could attenuate bone cancer pain through this mechanism. Tumor cell implantation(TCI)induced bone cancer pain model in rats was established. The rats were administered, respectively, with 20 μL of metformin(50, 100 μg), JNK inhibitor SP600125(10 μg), gap junction inhibitor(carbenoxolone, CBX)(10 μg)and AMPK inhibitor Compound C(CC)(10 μg). The Von Frey Assay was applied to test the mechanical pain threshold. The activity of Glial fibrillary acidic protein(GFAP), ionized calcium-binding adaptor molecule 1(IBA-1)and Connexin 43(Cx43)in spinal cord was evaluated by immunohistochemistry. Changes of p-JNK expression were detected by Western blot. JNK inhibitor SP600125 relieved TCI-induced bone cancer pain significantly in rats, while this analgesic effect was almost canceled by the blocker of gap junction carbenoxolone(CBX). Various concentration of metformin(50, 100 μg, i. t. )significantly inhibited TCI-induced mechanical allodynia and the changes of p-JNK and p-Cx43 expression were also reversed in spinal cord in rats. Together, these data suggested that activation of AMPK with metformin attenuated TCI-induced bone cancer pain via regulating the function of JNK-Gap junction in rats.

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