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1.
Neural Regen Res ; 18(6): 1339-1346, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36453421

RESUMO

Astrocytes are important cellular centers of cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level. Spinal cord injury results in aberrant cholesterol metabolism by astrocytes and excessive production of oxysterols, which have profound effects on neuropathology. 25-Hydroxycholesterol (25-HC), the main product of the membrane-associated enzyme cholesterol-25-hydroxylase (CH25H), plays important roles in mediating neuroinflammation. However, whether the abnormal astrocyte cholesterol metabolism induced by spinal cord injury contributes to the production of 25-HC, as well as the resulting pathological effects, remain unclear. In the present study, spinal cord injury-induced activation of thrombin was found to increase astrocyte CH25H expression. A protease-activated receptor 1 inhibitor was able to attenuate this effect in vitro and in vivo. In cultured primary astrocytes, thrombin interacted with protease-activated receptor 1, mainly through activation of the mitogen-activated protein kinase/nuclear factor-kappa B signaling pathway. Conditioned culture medium from astrocytes in which ch25h expression had been knocked down by siRNA reduced macrophage migration. Finally, injection of the protease activated receptor 1 inhibitor SCH79797 into rat neural sheaths following spinal cord injury reduced migration of microglia/macrophages to the injured site and largely restored motor function. Our results demonstrate a novel regulatory mechanism for thrombin-regulated cholesterol metabolism in astrocytes that could be used to develop anti-inflammatory drugs to treat patients with spinal cord injury.

2.
J Neuroinflammation ; 18(1): 130, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34116703

RESUMO

BACKGROUND: Astrocytes are the predominant glial cell type in the central nervous system (CNS) that can secrete various cytokines and chemokines mediating neuropathology in response to danger signals. D-dopachrome tautomerase (D-DT), a newly described cytokine and a close homolog of macrophage migration inhibitory factor (MIF) protein, has been revealed to share an overlapping function with MIF in some ways. However, its cellular distribution pattern and mediated astrocyte neuropathological function in the CNS remain unclear. METHODS: A contusion model of the rat spinal cord was established. The protein levels of D-DT and PGE2 synthesis-related proteinase were assayed by Western blot and immunohistochemistry. Primary astrocytes were stimulated by different concentrations of D-DT in the presence or absence of various inhibitors to examine relevant signal pathways. The post-injury locomotor functions were assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor scale. RESULTS: D-DT was inducibly expressed within astrocytes and neurons, rather than in microglia following spinal cord contusion. D-DT was able to activate the COX2/PGE2 signal pathway of astrocytes through CD74 receptor, and the intracellular activation of mitogen-activated protein kinases (MAPKs) was involved in the regulation of D-DT action. The selective inhibitor of D-DT was efficient in attenuating D-DT-induced astrocyte production of PGE2 following spinal cord injury, which contributed to the improvement of locomotor functions. CONCLUSION: Collectively, these data reveal a novel inflammatory activator of astrocytes following spinal cord injury, which might be beneficial for the development of anti-inflammation drug in neuropathological CNS.


Assuntos
Astrócitos/metabolismo , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Oxirredutases Intramoleculares/metabolismo , Doenças Neuroinflamatórias/metabolismo , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Animais , Animais Recém-Nascidos , Antígenos de Diferenciação de Linfócitos B/metabolismo , Técnicas de Cultura de Células , Modelos Animais de Doenças , Antígenos de Histocompatibilidade Classe II/metabolismo , Oxirredutases Intramoleculares/antagonistas & inibidores , Oxirredutases Intramoleculares/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Fatores Inibidores da Migração de Macrófagos/metabolismo , Masculino , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
3.
Cell Death Dis ; 11(11): 1016, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247124

RESUMO

Wet age-related macular degeneration, which is characterized by choroidal neovascularization (CNV) and induces obvious vision loss. Vascular endothelial growth factor (VEGF) family member VEGF-A (also named as VEGF) and its receptor VEGFR2 contribute to the pathogenesis of CNV. Choroidal endothelial cells (CECs) secret C-C motif chemokine ligand 2 (CCL2), which attracts macrophages to CNV lesion and promotes macrophage M1 polarization. Accordingly, infiltrating macrophages secret inflammatory cytokines to promote CNV. In vivo, intravitreal injection of fruquintinib (HMPL-013), an antitumor neovascularization drug, alleviated mouse CNV formation without obvious ocular toxicity. Meanwhile, HMPL-013 inhibited VEGF/VEGFR2 binding in CECs and macrophages, as well as macrophage M1 polarization. In vitro, noncontact coculture of human choroidal vascular endothelial cells (HCVECs) and macrophages under hypoxia conditions was established. HMPL-013 downregulated VEGF/VEGFR2/phosphoinositide-3-kinase/protein kinase B (AKT)/nuclear factor kappa B pathway and CCL2 secretion in HCVECs, as well as VEGF/VEGFR2-induced macrophage M1 polarization under hypoxia condition. In addition, HMPL-013 inhibited HCEVC derived CCL2-induced macrophage migration and M1 polarization, along with macrophage M1 polarization-induced HCVECs proliferation, migration, and tube formation. Altogether, HMPL-013 alleviated CNV formation might via breaking detrimental cross talk between CECs and macrophages.


Assuntos
Benzofuranos/uso terapêutico , Neovascularização de Coroide/metabolismo , Células Endoteliais/metabolismo , Macrófagos/metabolismo , Quinazolinas/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Benzofuranos/farmacologia , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Quinazolinas/farmacologia
4.
World J Clin Cases ; 8(12): 2520-2529, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32607329

RESUMO

BACKGROUND: Recent innovations in intensive care have improved the prognosis of patients with severe brain injuries and brought more patients with disorders of consciousness (DoC). Data are lacking regarding the long-term outcomes of those patients in China. It is necessary to study the long-term outcomes of patients with prolonged DoC in light of many factors likely to influence crucial decisions about their care and their life. AIM: To present the preliminary results of a DoC cohort. METHODS: This was a two-center prospective cohort study of inpatients with vegetative state (VS)/unresponsive wakefulness syndrome (UWS). The study outcomes were the recovery from VS/UWS to minimally conscious state (MCS) and the long-term status of patients with prolonged DoC considered in VS/UWS or MCS for up to 6 years. The patients were evaluated using the Glasgow coma scale, coma recovery scale-revised, and Glasgow outcome scale. The endpoint of follow-up was recovery of full consciousness or death. The changes in the primary clinical outcome improvement in clinical diagnosis were evaluated at 12 mo compared with baseline. RESULTS: The study population included 93 patients (62 VS/UWS and 31 MCS). The post-injury interval range was 28-634 d. Median follow-up was 20 mo (interquartile range, 12-37 mo). At the endpoint, 33 transitioned to an emergence from MCS or full consciousness, eight had a locked-in syndrome, and there were 35 patients remaining in a VS/UWS and 11 in an MCS. Seven (including one locked-in syndrome) patients (7.5%) died within 12 mo of injury. Compared with the unresponsive group (n = 52) at 12 mo, the responsive group (n = 41) had a higher proportion of males (87.8% vs 63.5%, P = 0.008), shorter time from injury (median, 40.0 d vs 65.5 d, P = 0.006), higher frequency of vascular etiology (68.3% vs 38.5%, P = 0.007), higher Glasgow coma scale score at admission (median, 9 vs 6, P < 0.001), higher coma recovery scale-revised score at admission (median, 9 vs 2.5, P < 0.001), at 1 mo (median, 14 vs 5, P < 0.001), and at 3 mo (median, 20 vs 6, P < 0.001), lower frequency of VS/UWS (36.6% vs 90.0%, P < 0.001), and more favorable Glasgow outcome scale outcome (P < 0.001). CONCLUSION: Patients with severe DoC, despite having strong predictors of poor prognosis, might recover consciousness after a prolonged time of rehabilitation. An accurate initial diagnosis of patients with DoC is critical for predicting outcome and a long-term regular follow-up is also important.

5.
Neuroscience ; 408: 349-360, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31026565

RESUMO

Oxysterol derived from cholesterol metabolism is involved in the inflammatory activation, and consequently in development of major chronic diseases. Multiple cytokines have been found to induce the expression of cholesterol metabolism-related enzymes. Several studies have shown that the protein level of cholesterol-25-hydroxylase (CH25H) is remarkably increased in response to injury of central nervous system (CNS), but little is known about the mechanisms of cytokine-induced expression of CH25H in specific cell types, and the resultant effects. In the present study, we demonstrated that ch25h expression was significantly upregulated in the astrocytes of rat injured spinal cord, in parallel with those of MIF. Administration of MIF inhibitor 4-IPP in the lesion sites attenuated injury-induced ch25h expression. MIF facilitated ch25h expression of astrocytes through interaction with CD74 membrane receptor, which in turn promoted production of chemokines, as identified by transcriptome profiles. MIF-induced release of oxysterol 25-hydroxycholesterol (25-HC) from astrocytes affects cell migration, but inhibited cell viability in dose-dependent manner, suggesting that MIF aggravates progressive neuropathology through regulation of cholesterol metabolism following CNS injury. These results have provided a novel mechanism and a potential therapeutic strategy for injured CNS.


Assuntos
Astrócitos/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Fatores Inibidores da Migração de Macrófagos/farmacologia , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/efeitos dos fármacos , Esteroide Hidroxilases/metabolismo , Animais , Astrócitos/metabolismo , Fatores Inibidores da Migração de Macrófagos/antagonistas & inibidores , Fatores Inibidores da Migração de Macrófagos/metabolismo , Masculino , Pirimidinas/farmacologia , Ratos , Medula Espinal/metabolismo
6.
J Neuroinflammation ; 16(1): 85, 2019 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-30981278

RESUMO

BACKGROUND: Astrocytes have been shown to produce several pro- and anti-inflammatory cytokines to maintain homeostasis of microenvironment in response to vast array of CNS insults. Some inflammation-related cytokines are responsible for regulating such cell events. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that can be inducibly expressed in the lesioned spinal cord. Unknown is whether MIF can facilitate the production of immunosuppressive factors from astrocytes to tune milieu following spinal cord injury. METHODS: Following establishment of contusion SCI rat model, correlation of PGE2 synthesis-related protein levels with that of MIF was assayed by Western blot. ELISA assay was used to detect production of PGE2, TNF-α, IL-1ß, and IL-6. Immunohistochemistry was performed to observe colocalization of COX2 with GFAP- and S100ß-positive astrocytes. The primary astrocytes were treated by various inhibitors to validate relevant signal pathway. RESULTS: The protein levels of MIF and COX2, but not of COX1, synchronously increased following spinal cord injury. Treatment of MIF inhibitor 4-IPP to the lesion sites significantly reduced the expression of COX2, mPGES-1, and as a consequence, the production of PGE2. Astrocytes responded robustly to the MIF interference, by which regulated MAPK/COX2/PGE2 signal pathway through coupling with the CD74 membrane receptor. MIF-induced production of PGE2 from astrocytes was able to suppress production of TNF-α, but boosted production of IL-1ß and IL-6 in LPS-activated macrophages. CONCLUSION: Collectively, these results reveal a novel function of MIF-mediated astrocytes, which fine-tune inflammatory microenvironment to maintain homeostasis. These suggest an alternative therapeutic strategy for CNS inflammation.


Assuntos
Astrócitos/efeitos dos fármacos , Dinoprostona/metabolismo , Inflamação/etiologia , Inflamação/patologia , Fatores Inibidores da Migração de Macrófagos/farmacologia , Traumatismos da Medula Espinal/complicações , Animais , Animais Recém-Nascidos , Antígenos de Diferenciação de Linfócitos B/metabolismo , Astrócitos/química , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Indóis/farmacologia , Macrófagos/efeitos dos fármacos , Masculino , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Sprague-Dawley , Subunidade beta da Proteína Ligante de Cálcio S100/metabolismo , Medula Espinal/citologia
7.
J Neuroinflammation ; 15(1): 253, 2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30180853

RESUMO

BACKGROUND: Astrocytes act as immune effector cells with the ability to produce a wide array of chemokines and cytokines in response to various stimuli. Macrophage migration inhibitory factor (MIF) is inducibly expressed in injured spinal cord contributing to excessive inflammation that affects motor functional recovery. Unknown is whether MIF can facilitate inflammatory responses through stimulating release of chemokines from astrocytes following spinal cord injury. METHODS: Following the establishment of the contusion spinal cord injury rat model, the correlation of chemokine (C-C motif) ligand 5 (CCL5) expression with that of MIF was assayed by Western blot, ELISA, and immunohistochemistry. Immunoprecipitation was used to detect MIF interaction with membrane CD74 receptor. Intracellular signal transduction of MIF/CD74 axis was analyzed by transcriptome sequencing of primary astrocytes and further validated by treatment of various inhibitors. The effects of CCL5 released by astrocytes on macrophage migration were performed by transwell migration assay. The post-injury locomotor functions were assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor scale. RESULTS: The protein levels of chemokine CCL5/RANTES were remarkably increased in the astrocytes of rat injured spinal cord, in parallel with the expression of MIF. Treatment of MIF inhibitor 4-IPP in the lesion sites resulted in a significant decrease of CCL5 protein levels. In vitro study revealed MIF was capable of facilitating CCL5 production of astrocytes through interaction with CD74 membrane receptor, and knockdown of this receptor attenuated such effects. Production of CCL5 in astrocytes was significantly blocked by inhibitor of c-Jun N-terminal kinase, rather than by those of ERK and P38. Recombinant CCL5 protein was found to be more effective in promoting migration of M2- compared to M1-type macrophages. CONCLUSION: Collectively, these data reveal a novel function of MIF in regulation of CCL5 release from astrocytes, which in turn favors for recruitment of inflammatory cells to the injured site of the spinal cord, in association with activation of excessive inflammation.


Assuntos
Astrócitos/efeitos dos fármacos , Quimiocina CCL5/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Oxirredutases Intramoleculares/farmacologia , Fatores Inibidores da Migração de Macrófagos/farmacologia , Traumatismos da Medula Espinal/patologia , Animais , Animais Recém-Nascidos , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/metabolismo , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida/metabolismo , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Interleucina-13/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Atividade Motora/efeitos dos fármacos , Pirimidinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Medula Espinal/citologia , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/fisiopatologia
8.
Inflammation ; 41(6): 2003-2011, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30073566

RESUMO

The purpose of this study was to investigate the inhibition neuroinflammation mechanisms of hyperbaric oxygen therapy (HBOT). Primary astrocytes were incubated with lipopolysaccharide (LPS) after which they underwent HBOT and separate administration of inflammatory cytokine inhibitors. The respective expression of inflammatory factors was then detected. Results showed that LPS significantly induced increases in the expression levels of chemokine (C-X-C motif) ligand 1 (CXCL1), chemokine C-C motif ligand 2 (CCL2), phospho-nuclear factor-kappa B (p-NF-κB), phospho-c-Jun N-terminal kinase (p-JNK), phospho-extracellular signal-regulated kinase (p-ERK), and phospho-p38 (p-p38) in cultured astrocytes and peaked at 3 h. HBOT downregulated the expression of some inflammation mediators including CXCL1 and CCL2. Furthermore, HBOT inhibited the expression of some up-stream regulators of inflammation mediators including p-NF-κB, p-JNK, p-p38 (at 3 and 6 h), and p-ERK (3 h). Inhibitors of NF-κB, ERK, and JNK (BAY117082, PD98059, and SP600125) significantly suppressed the expression of CXCL1 and CCL2 that were induced by LPS for 3 h. However, the p38 inhibitor, SB203580, had no obvious effect on expression levels of CXCL1 and CCL2. In conclusion, we found that HBOT inhibits neuroinflammation via regulation of the LPS-induced NF-κB/mitogen-activated protein kinases (MAPKs, JNK, and ERK) -CCL2/CXCL1 signaling pathways.


Assuntos
Astrócitos/metabolismo , Oxigenoterapia Hiperbárica , Inflamação/prevenção & controle , Lipopolissacarídeos/farmacologia , Transdução de Sinais , Animais , Astrócitos/patologia , Células Cultivadas , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CXCL1/antagonistas & inibidores , Humanos , Sistema de Sinalização das MAP Quinases , NF-kappa B/antagonistas & inibidores
9.
Endocrine ; 60(2): 292-300, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29411305

RESUMO

PURPOSE: Diabetic peripheral neuropathy (DPN), a common microvascular complication of diabetes, is linked to glycaemic derangements. Glycaemic variability, as a pattern of glycaemic derangements, is a key risk factor for diabetic complications. We investigated the association of glycaemic variability with DPN in a large-scale sample of type 2 diabetic patients. METHODS: In this cross-sectional study, we enrolled 982 type 2 diabetic patients who were screened for DPN and monitored by a continuous glucose monitoring (CGM) system between February 2011 and January 2017. Multiple glycaemic variability parameters, including the mean amplitude of glycaemic excursions (MAGE), mean of daily differences (MODD), standard deviation of glucose (SD), and 24-h mean glucose (24-h MG), were calculated from glucose profiles obtained from CGM. Other possible risks for DPN were also examined. RESULTS: Of the recruited type 2 diabetic patients, 20.1% (n = 197) presented with DPN, and these patients also had a higher MAGE, MODD, SD, and 24-h MG than patients without DPN (p < 0.001). Using univariate and multiple logistic regression analyses, MAGE and conventional risks including diabetic duration, HOMA-IR, and hemoglobin A1c (HbA1c) were found to be independent contributors to DPN, and the corresponding odds ratios (95% confidence interval) were 4.57 (3.48-6.01), 1.10 (1.03-1.17), 1.24 (1.09-1.41), and 1.33 (1.15-1.53), respectively. Receiver operating characteristic analysis indicated that the optimal MAGE cutoff value for predicting DPN was 4.60 mmol/L; the corresponding sensitivity was 64.47%, and the specificity was 75.54%. CONCLUSIONS: In addition to conventional risks including diabetic duration, HOMA-IR and HbA1c, increased glycaemic variability assessed by MAGE is a significant independent contributor to DPN in type 2 diabetic patients.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/etiologia , Doenças do Sistema Nervoso Periférico/etiologia , Adulto , Idoso , Automonitorização da Glicemia , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Neuropatias Diabéticas/sangue , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/sangue , Curva ROC
10.
Oncotarget ; 8(2): 2719-2730, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-27926507

RESUMO

Astrocytes, the major glial cell population of the central nervous system (CNS), play important physiological roles related to CNS homeostasis. Growing evidence demonstrates that astrocytes trigger innate immune responses under challenge of a variety of proinflammatory cytokines. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine mainly secreted from monocytes/macrophages, is involved in inflammation-associated pathophysiology. Here, we displayed that expression of MIF significantly increased following spinal cord injury, in colocalization with microglia and astrocytes. MIF elicited inflammatory responses of astrocytes via activation of CD74 receptor and extracellular signal-related kinase (ERK) pathway. Transcriptome analysis revealed that inflammation-related factors cholesterol 25-hydroxylase (Ch25h) and phospholipase A2-IIA (Pla2g2a), downstream of MIF/CD74 axis, were potentially implicated in the mediating inflammatory response of astrocytes. Our results provided a new target for interference of CNS inflammation after insults.


Assuntos
Antígenos de Diferenciação de Linfócitos B/metabolismo , Astrócitos/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Inflamação/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Animais , Antígenos de Diferenciação de Linfócitos B/genética , Astrócitos/efeitos dos fármacos , Biomarcadores , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes , Antígenos de Histocompatibilidade Classe II/genética , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Fatores Inibidores da Migração de Macrófagos/genética , Fatores Inibidores da Migração de Macrófagos/farmacologia , Masculino , Ligação Proteica , Ratos , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia
11.
Exp Brain Res ; 233(12): 3359-65, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26267487

RESUMO

Hyperbaric oxygen (HBO) therapy helps alleviate secondary injury following brain trauma [traumatic brain injury (TBI)], although the mechanisms remain unclear. In this study, we assessed recovery of post-TBI spatial learning and memory in rats using the Morris water maze (MWM) and measured changes in apparent diffusion coefficient in the hippocampus by diffusion-weighted imaging (DWI) to evaluate possible therapeutic effects of HBO on TBI-associated brain edema. DWIs were obtained 8, 24, 48 h, 7 days, and 14 days post-TBI. Daily HBO therapy significantly improved post-TBI MWM performance and reduced edema in the ipsilateral hippocampus, suggesting that the therapeutic efficacy of HBO is mediated, at least in part, by a reduction in brain edema.


Assuntos
Edema Encefálico/terapia , Lesões Encefálicas/terapia , Hipocampo/patologia , Oxigenoterapia Hiperbárica/métodos , Aprendizagem em Labirinto/fisiologia , Animais , Comportamento Animal/fisiologia , Edema Encefálico/etiologia , Lesões Encefálicas/complicações , Imagem de Difusão por Ressonância Magnética , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/fisiologia
12.
Neurochem Res ; 40(8): 1620-30, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26123482

RESUMO

The Mpv17 gene encodes a mitochondrial inner-membrane protein that has been implicated in several cell activities. Almost all studies have previously indicated that loss of function or gene-inactivated in Mpv17 can induce the development of disease. Here, we explored the roles of Mpv17 protein in the pathophysiology of intracerebral hemorrhage (ICH). An ICH rat model was established and assessed by behavioral tests. Using western blot and immunohistochemistry, significant up-regulation of Mpv17 was found in neurons in brain areas surrounding the hematoma following ICH. The increase of Mpv17 expression was found to be accompanied by the enhanced expression of p53, Bax, cytochrome c (Cyt c) and active caspase-3, and decreased expression of Bcl-2 in the pathological process of rat ICH. Furthermore, immunofluorescent staining revealed that Mpv17 co-localized with p53, Bax and active caspase-3 in neurons, suggesting its biological function in the process of neuronal apoptosis. Our in vitro study, using Mpv17 RNA interference in primary cortical neurons, indicated that Mpv17 might exert its anti-apoptotic function in neuronal apoptosis. Thus, Mpv17 may play a role in protecting the brain from secondary damage following ICH.


Assuntos
Hemorragia Cerebral/metabolismo , Proteínas de Membrana/biossíntese , Proteínas Mitocondriais/biossíntese , Fatores Etários , Animais , Hemorragia Cerebral/patologia , Regulação da Expressão Gênica , Masculino , Ratos , Ratos Sprague-Dawley
13.
Neurochem Res ; 40(6): 1220-31, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25998883

RESUMO

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been recently shown to elicit inflammatory response in a number of cell-types. However, whether TCDD could provoke inflammation in astrocytes, the most abundant glial cells in central nervous system (CNS), remains virtually unknown. In the present study, we showed that TCDD exposure could induce evident astrocyte activation both in vivo and in vitro. Further, we found that TGF-ß-activated kinase 1 (TAK1), a critical regulator of NF-κB signaling, was rapidly phosphorylated in the process of TCDD-induced reactive astroglia. Exposure to TCDD led to rapid TAK1 and NF-κB p65 phosphorylation, as well as IKBα degradation. Moreover, blockage of TAK1 using siRNA oligos or TAK1 inhibitor 5Z-7-oxozeaenol significantly attenuated TCDD-induced astrocyte activation as well as the release of TNF-α. Finally, we showed that the conditioned medium of TCDD-treated astrocytes promoted the apoptosis of PC12 neuronal cells, which could be blocked with the pre-treatment of TAK1 inhibitor. Taken together, these findings suggested that TCDD could promote the inflammatory activation of astrocytes through modulating TAK1-NF-κB cascade, implicating that reactive astrocytes might contribute to TCDD-induced adverse effects on CNS system.


Assuntos
Astrócitos/efeitos dos fármacos , Poluentes Ambientais/toxicidade , MAP Quinase Quinase Quinases/efeitos dos fármacos , NF-kappa B/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultivo Condicionados , Feminino , Proteínas I-kappa B/efeitos dos fármacos , Proteínas I-kappa B/metabolismo , MAP Quinase Quinase Quinases/antagonistas & inibidores , Células PC12 , Fosforilação , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Fator de Transcrição RelA/metabolismo
14.
J Mol Neurosci ; 54(4): 653-63, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25060335

RESUMO

Adenylate cyclase-associated protein 1 (CAP1), a member of cyclase-associated proteins involved in the regulation of actin filaments, was recently reported to play a role in the pathology of sciatic nerves injury. However, the distribution and function of CAP1 in the central nervous system (CNS) remain unclear. To investigate whether CAP1 is involved in CNS injury and repair, we used an acute traumatic brain injury (TBI) model in adult rats. Western blot analysis and immunohistochemistry showed a significant upregulation of CAP1 in ipsilateral peritrauma cortex compared with the contralateral and sham-operated ones. Double immunofluorescence staining showed that CAP1 was co-expressed with glial fibrillary acidic protein (GFAP). In addition, we detected that Ki-67 had colocalization with GFAP and CAP1 after TBI. In vitro, during the process of lipopolysaccharide (LPS)-induced primary astrocyte proliferation, we observed enhanced expression of CAP1. Specially, CAP1-specific siRNA-transfected primary astrocytes show significantly decreased ability for proliferation. Together, all these data indicated that the change of CAP1 protein expression was associated with astrocyte proliferation after the trauma of the central nervous system (CNS).


Assuntos
Astrócitos/metabolismo , Lesões Encefálicas/metabolismo , Proliferação de Células , Proteínas do Citoesqueleto/metabolismo , Animais , Astrócitos/fisiologia , Proteínas do Citoesqueleto/genética , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Regulação para Cima
15.
Cell Mol Neurobiol ; 34(7): 951-61, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25035058

RESUMO

Somatostatins are peptide hormones that regulate diverse cellular processes, such as neurotransmission, cell proliferation, apoptosis, and endocrine signaling as well as inhibiting the release of many hormones and other secretory proteins. SSTR1 is a member of the superfamily of somatostatin receptors possessing seven-transmembrane segments. Aberrant expression of SSTR1 has been implicated in several human diseases, including pseudotumor cerebri, and oncogenic osteomalacia. In this study, we investigated a potential role of SSTR1 in the regulation of neuronal apoptosis in the course of intracerebral hemorrhage (ICH). A rat ICH model in the caudate putamen was established and subjected to behavioral tests. Western blot and immunohistochemistry indicated a remarkable up-regulation of SSTR1 expression surrounding the hematoma after ICH. Double-labeled immunofluorescence showed that SSTR1 was mostly co-localized with neurons, and was rarely distributed in activated astrocytes and microglia. Additionally, SSTR1 co-localized with active-caspase-3 and bcl-2 around the hematoma. The expression of active-caspase-3 was parallel with that of SSTR1 in a time-dependent manner. In addition, SSTR1 knockdown specifically resulted in reduced neuronal apoptosis in PC12 cells. All our findings suggested that up-regulated SSTR1 contributed to neuronal apoptosis after ICH, which was accompanied with reduced expression of bcl-2.


Assuntos
Apoptose , Hemorragia Cerebral/metabolismo , Hemorragia Cerebral/patologia , Neurônios/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Somatostatina/metabolismo , Regulação para Cima , Envelhecimento/patologia , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Western Blotting , Caspase 3/metabolismo , Hemorragia Cerebral/enzimologia , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Imunofluorescência , Hematoma/metabolismo , Hematoma/patologia , Hemina/farmacologia , Humanos , Masculino , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Células PC12 , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos
16.
Environ Toxicol Pharmacol ; 38(1): 119-30, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24930124

RESUMO

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been reported to cause alterations in cognitive and motor behavior during both development and adulthood. In this study, the neuronal nitric oxide synthase (nNOS) signaling pathway was investigated in differentiated pheochromocytoma (PC12) cells to better understand the mechanisms of TCDD-induced neurotoxicity. TCDD exposure induced a time- and dose-dependent increase in nNOS expression. High levels of nitric oxide (NO) production by nNOS activation induced mitochondrial cytochrome c (Cyt-c) release and down-regulation of Bcl-2. Additionally, TCDD increased the expression of active caspase-3 and significantly led to apoptosis in PC12 cells. However, these effects above could be effectively inhibited by the addition of 7-nitroindazole (7-NI), a highly selective nNOS inhibitor. Moreover, in the brain cortex of Sprague-Dawley (SD) rats, nNOS was also found to have certain relationship with TCDD-induced neuronal apoptosis. Together, our findings establish a role for nNOS as an enhancer of TCDD-induced apoptosis in PC12 cells.


Assuntos
Poluentes Ambientais/toxicidade , Síndromes Neurotóxicas/metabolismo , Neurotoxinas/toxicidade , Óxido Nítrico Sintase Tipo I/metabolismo , Dibenzodioxinas Policloradas/toxicidade , Animais , Apoptose/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Citocromos c/metabolismo , Proteína 4 Homóloga a Disks-Large , Feminino , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Neurônios/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Óxido Nítrico/metabolismo , Células PC12 , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
17.
Neurochem Res ; 39(5): 862-74, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24700281

RESUMO

LIN28, an RNA-binding protein, is known to be involved in the regulation of many cellular processes, such as embryonic stem cell proliferation, cell fate succession, developmental timing, and oncogenesis. However, its expression and function in central nervous system still unclear. In this study, we performed an acute spinal cord contusion injury (SCI) model in adult rats and investigated the dynamic changes of LIN28 expression in spinal cord. Western blot and immunohistochemistry analysis revealed that LIN28 was present in normal spinal cord. It gradually increased, reached a peak at 3 day, and then nearly declined to the basal level at 14 days after SCI. Double immunofluorescence staining showed that LIN28 immunoreactivity was found in neurons, astrocytes and a handful of microglia. Interestingly, LIN28 expression was increased predominantly in astrocytes but not in neurons. Moreover, the colocalization of LIN28 and proliferating cell nuclear antigen was detected after injury. Western blot showed that LIN28 participated in lipopolysaccharide (LPS) induced astrocytes inflammatory responses by NF-κB signaling pathway. These results suggested that LIN28 may be involved in the pathologic process of SCI, and further research is needed to have a good understanding of its function and mechanism.


Assuntos
Proteínas de Ligação a RNA/biossíntese , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Animais , Astrócitos/metabolismo , Inflamação/fisiopatologia , Masculino , Antígeno Nuclear de Célula em Proliferação/biossíntese , Ratos Sprague-Dawley
18.
Brain Res ; 1564: 41-51, 2014 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-24709117

RESUMO

The glycinamide ribonucleotide transformylase (GART) gene, a trifunctional polypeptide, has phosphoribosylglycinamide formyltransferase, phosphoribosylglycinamide synthetase, and phosphoribosylaminoimidazole synthetase activity, and is required for de novo purine biosynthesis. GART is highly conserved in vertebrates. Alternative splicing of GART results in two transcript variants encoding different isoforms. However, the expression and function of GART in the central nervous system lesion are still unclear. In this study, we used a traumatic spinal cord injury (SCI) model in adult Sprague-Dawley rats and investigated the dynamic changes of GART protein expression in the spinal cord. Western blot analysis revealed that GART was present in sham-operated spinal cord. It gradually increased, reached a peak at day 3 after SCI, and then declined during the following days. Double immunofluorescence staining revealed a widespread of GART, and the majority of GARTs are detected in astrocytes. After injury, GART expression was increased predominantly in astrocytes, positively correlated with the highly expressed proliferating cell nuclear antigen (PCNA). Knockdown of GART expression in cultured primary astrocytes by siRNA revealed that expression of GART in astrocytes plays a role in the LPS-induced release of pro-inflammatory factors, such as TNF-α and IL-6. These results showed that GART may participate in the pathophysiology of SCI, and more research is needed to have a good understanding of its function and mechanism.


Assuntos
Fosforribosilglicinamido Formiltransferase/metabolismo , Traumatismos da Medula Espinal/enzimologia , Animais , Astrócitos/enzimologia , Astrócitos/metabolismo , Citocinas/metabolismo , Inflamação/enzimologia , Masculino , Atividade Motora , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/metabolismo
19.
J Neurochem ; 129(5): 839-49, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24673440

RESUMO

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental pollutant that could induce significant toxic effects in the human nervous system. However, the underlying molecular mechanism has not been entirely elucidated. Reactive astrogliosis has implicated in various neurological diseases via the production of a variety of pro-inflammatory mediators. Herein, we investigated the potential role of TCDD in facilitating astrocyte activation and the underlying molecular mechanisms. We showed that TCDD induced rapid astrocyte activation following TCDD exposure, which was accompanied by significantly elevated expression of Src-Suppressed-C Kinase Substrate (SSeCKS), a protein involved in protein kinase C (PKC)-mediated Nuclear Factor kappa B signaling, suggesting a possible involvement of PKC-induced SSeCKS activation in TCDD-triggered reactive astroglia. In keeping with the finding, we found that the level of phosphorylated Nuclear Factor kappa B p65 was remarkably increased after TCDD treatment. Furthermore, interference of SSeCKS attenuated TCDD-induced inducible nitric oxide synthase, glial fibrillary acidic protein, phospho-p65 expression, and tumor necrosis factor-α secretion in astrocytes. In addition, pre-treatment with PKC inhibitor also attenuated TCDD-induced astrocyte activation, as well as SSeCKS expression. Interestingly, we found that TCDD treatment could lead to SSeCKS perinuclear localization, which could be abolished after treatment with PKC inhibitor. Finally, we showed that inhibition of PKC activity or SSeCKS expression would impair TCDD-triggered tumor necrosis factor-α secretion. Our results suggested that TCDD exposure could lead to astrocyte activation through PKC/SSeCKS-dependent mechanisms, highlighting that astrocytes might be important target of TCDD-induced neurotoxicity. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) elicits neurotoxic effects. Here, we show TCDD induces pro-inflammatory responses in astrocytes. TCDD initiates an increase of [Ca2+]i, followed by the activation of PKC, which then induces the activation of Src-suppressed C-kinase substrate (SSeCKS). SSeCKS promotes NF-κB activation and the secretion of TNF-α and nitric oxide in astrocytes.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Astrócitos/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Poluentes Ambientais/toxicidade , Dibenzodioxinas Policloradas/toxicidade , Proteína Quinase C/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Núcleo Celular/metabolismo , Citocinas/metabolismo , Citoplasma/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Imuno-Histoquímica , Inflamação/patologia , NF-kappa B/metabolismo , Cultura Primária de Células , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Transfecção
20.
J Mol Histol ; 45(3): 337-48, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24272071

RESUMO

Adenylate cyclase-associated protein 1 (CAP1), a member of cyclase-associated proteins that regulating actin dynamics, was shown to regulate actin filaments, localize to dynamic actin structures and mediate such processes as establishment of cell polarity, motility, morphogenesis, receptor-mediated endocytosis and mRNA location. But little is known about the role of CAP1 during peripheral nervous system injury. Here, we found the spatiotemporal protein expression of CAP1 after sciatic nerve crush. After crush, CAP1 had an increased protein expression level, reached a peak at about day 5 and then returned to the normal level at 4 weeks, similar to Oct-6. Besides, in 5-day injured tissue, using double immunofluorescent staining we found CAP1 had a colocalization with S100 and Oct-6. In vitro, during the process of cAMP-induced Schwann cells differentiation, we observed enhanced expression of CAP1 and P0. Specially, CAP1-specific siRNA-tranfected SCs did not show significant actin structure which form cellure surface tension and protrusion shape after cAMP treatment. And we observed the interaction of CAP1 with actin and that CAP1-specific siRNA-transfected SCs had a decreased motility and migration. Together, all these data indicated that the change of CAP1 protein expression was associated with Schwann cells motility and differentiation after the crush of sciatic nerve.


Assuntos
Actinas/metabolismo , Proteínas do Citoesqueleto/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo , Células de Schwann/citologia , Células de Schwann/metabolismo , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Movimento Celular , AMP Cíclico/metabolismo , AMP Cíclico/farmacologia , Proteínas do Citoesqueleto/genética , Modelos Animais de Doenças , Expressão Gênica , Regulação da Expressão Gênica , Masculino , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , Ligação Proteica , Transporte Proteico , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos
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