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1.
J Cancer Res Ther ; 14(7): 1606-1612, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30589047

RESUMO

SUBJECTS: The aim of this study is to compare the efficacy and safety of en bloc bladder tumor-endoscopic submucosal dissection (BT-ESD) and conventional transurethral resection of BT (TURBT) in nonmuscle invasive bladder cancer (NMIBC) patients. METHODS: A retrospective cohort study was carried out in Shaanxi Provincial People's Hospital. A total of 193 eligible NMIBC (Ta/T1) patients were enrolled in this study (95 cases in BT-ESD group and 98 cases in TURBT group), between November 2013 and January 2017. The operation time, blood loss, postoperative bladder irrigation time, catheter indwelling time, hospital stay time, and complications were compared. Data were presented as median (range). Chi-squared or rank-sum test, two-way ANOVA, and Mantel-Cox (Log-Rank) test were performed using statistical software. A threshold of P < 0.05 was defined as statistically significant. RESULTS: The average operation time in the BT-ESD group was longer than that of in the TURBT group (40.0 [5.0, 100.0] min vs. 19.5 [3.0, 55.5] min); however, no significant longer operating time (P < 0.05) were observed in the smaller tumor (0 cm-3 cm). The postoperative bladder irrigation time, catheter indwelling time, and hospital stay in BT-ESD group were significantly shorter than that of in TURBT group (9.0 [5.0, 18.0] h, 2.5 [1.0, 4.0] d and 3.5 [2.0, 5.0] d for BT-ESD; 18.0 [12.0, 48.0] h, 3.5 [2.0, 7.0] d, and 4.5 [3.0, 8.0] d for TURBT). In addition, the BT-ESD group showed the decreased overall incidence of complications (2.1% vs. 9.2%). The univariate and multivariate analyses indicated an association between surgical option and tumor recurrence (hazard ratio = 5.624, odds ratio = 95% confidence interval = 1.582-19.991), Kaplan-Meir analysis showed significant difference in recurrence-free survival (RFS) (94.7% for ESD group vs. 78.4% for TURBT group) at 33 months. CONCLUSIONS: The application of the HybridKnife lead to a decrease in complications and RFS rate, which was a more safe and effective approach for NMIBC than conventional TURBT.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Terapia Combinada , Ressecção Endoscópica de Mucosa/métodos , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Recidiva , Carga Tumoral , Neoplasias da Bexiga Urinária/mortalidade , Adulto Jovem
2.
Dev Cell ; 35(5): 568-583, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26625958

RESUMO

Progression from brown preadipocytes to adipocytes engages two transcriptional programs: the expression of adipogenic genes common to both brown fat (BAT) and white fat (WAT), and the expression of BAT-selective genes. However, the dynamics of chromatin states and epigenetic enzymes involved remain poorly understood. Here we show that BAT development is selectively marked and guided by repressive H3K27me3 and is executed by its demethylase Jmjd3. We find that a significant subset of BAT-selective genes, but not common fat genes or WAT-selective genes, are demarcated by H3K27me3 in both brown and white preadipocytes. Jmjd3-catalyzed removal of H3K27me3, in part through Rreb1-mediated recruitment, is required for expression of BAT-selective genes and for development of beige adipocytes both in vitro and in vivo. Moreover, gain- and loss-of-function Jmjd3 transgenic mice show age-dependent body weight reduction and cold intolerance, respectively. Together, we identify an epigenetic mechanism governing BAT fate determination and WAT plasticity.


Assuntos
Tecido Adiposo Marrom/embriologia , Tecido Adiposo Branco/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Histona Desmetilases com o Domínio Jumonji/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Peso Corporal , Proteínas de Ligação a DNA/metabolismo , Canais Iônicos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/metabolismo , Mutação Puntual , Regiões Promotoras Genéticas , Análise de Sequência de RNA , Termogênese/genética , Fatores de Transcrição/metabolismo , Transgenes , Proteína Desacopladora 1
3.
J Immunol ; 190(1): 296-306, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23197262

RESUMO

We have previously shown that mice challenged with a lethal dose of A/Puerto Rico/8/34-OVA(I) are protected by injection of 4-8 × 10(6) in vitro-generated Tc1 or Tc17 CD8(+) effectors. Viral load, lung damage, and loss of lung function are all reduced after transfer. Weight loss is reduced and survival increased. We sought in this study to define the mechanism of this protection. CD8(+) effectors exhibit multiple effector activities, perforin-, Fas ligand-, and TRAIL-mediated cytotoxicity, and secretion of multiple cytokines (IL-2, IL-4, IL-5, IL-9, IL-10, IL-17, IL-21, IL-22, IFN-γ, and TNF) and chemokines (CCL3, CCL4, CCL5, CXCL9, and CXCL10). Transfer of CD8(+) effectors into recipients, before infection, elicits enhanced recruitment of host neutrophils, NK cells, macrophages, and B cells. All of these events have the potential to protect against viral infections. Removal of any one, however, of these potential mechanisms was without effect on protection. Even the simultaneous removal of host T cells, host B cells, and host neutrophils combined with the elimination of perforin-mediated lytic mechanisms in the donor cells failed to reduce their ability to protect. We conclude that CD8(+) effector T cells can protect against the lethal effects of viral infection by means of a large number of redundant mechanisms.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Linfócitos T CD8-Positivos/transplante , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Cultivadas , Testes Imunológicos de Citotoxicidade/métodos , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Infecções por Orthomyxoviridae/virologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/transplante , Linfócitos T Citotóxicos/virologia
4.
PLoS Genet ; 8(6): e1002761, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22719268

RESUMO

Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes.


Assuntos
Glicemia , Gluconeogênese , Histona Desmetilases com o Domínio Jumonji , Fígado/metabolismo , Animais , Glicemia/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Células Cultivadas , Regulação da Expressão Gênica , Gluconeogênese/genética , Glucose-6-Fosfatase/metabolismo , Hepatócitos/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno/genética , Ratos , Fatores Estimuladores Upstream/metabolismo
5.
Infect Immun ; 79(4): 1526-35, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21263022

RESUMO

Host cells use metabolic signaling through the LXRα nuclear receptor to defend against Listeria monocytogenes infection. 25-Hydroxycholesterol is a natural ligand of LXRs that is produced by the enzyme cholesterol 25-hydroxylase (CH25H). We found that expression of Ch25h is upregulated following L. monocytogenes infection in a beta interferon (IFN-ß)-dependent fashion. Moreover, increased Ch25h expression promotes survival of L. monocytogenes-infected cells and increases sensitivity of the host to infection. We determined that expression of Cd5l, a prosurvival gene, is controlled by CH25H. In addition, we found that CD5L inhibits activation of caspase-1, promoting survival of infected macrophages. Our results reveal a mechanism by which an intracellular pathogen can prolong survival of infected cells, thus providing itself with a protected environment in which to replicate.


Assuntos
Listeria monocytogenes/fisiologia , Listeriose/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Transdução de Sinais/fisiologia , Esteroide Hidroxilases/biossíntese , Animais , Proteínas Reguladoras de Apoptose/biossíntese , Western Blotting , Feminino , Expressão Gênica , Regulação da Expressão Gênica/genética , Marcação In Situ das Extremidades Cortadas , Listeriose/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores Imunológicos/biossíntese , Receptores Depuradores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima
6.
Cell Mol Neurobiol ; 31(4): 541-50, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21234798

RESUMO

Spinal Muscular Atrophy (SMA) is a neurodegenerative disease that is caused by deletion of the SMN (Survival of Motor Neuron) gene. The SMN protein is essential for cell survival and co-localized with TIA-1/R and G3BP, two characteristic markers of stress granules (SGs). To further study the SMN function in stress granules and in response to stress, we generated stable cell lines with SMN knockdown. Our data indicate that suppression of SMN drastically reduces cellular ability to form stress granules in response to stress treatment. In addition, we show that SMN deficiency sensitizes cells to sodium arsenite and H(2)O(2), two well-known stress inducers, leading to cell death at a much lower concentration of inducers in SMN knockdown cells than in control cells. Interestingly, the cell death is correlated with formation of stress granules, suggesting that involvement of SMN in formation of stress granules may play an important role in cell survival. Furthermore, rescue of SGs formation by overexpression of G3BP can reverse the defective formation of stress granules and results in partial abrogation of cell death against SMN deficiency. We deduce that modulation of stress response may be useful for potential SMN treatment.


Assuntos
Grânulos Citoplasmáticos/metabolismo , Estresse Fisiológico , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Animais , Arsenitos/farmacologia , Proteínas de Transporte/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Células PC12 , Fosforilação/efeitos dos fármacos , Interferência de RNA/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , Ratos , Compostos de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Transfecção
7.
Asian J Androl ; 11(6): 711-5, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19734936

RESUMO

We conducted an analysis of the Kallmann syndrome 1 (KAL-1) genotype in 17 patients with Kallmann syndrome (KS), 9 patients with normosmic idiopathic hypogonadotropic hypogonadism (nIHH) and 20 age-matched normal men in Northwestern China. To do this, we used multiplex PCR analysis with exon-flanking primers and automated sequencing techniques with peripheral blood DNA samples. Intragenic deletions were found at the KAL-1 locus in two KS patients. One case with an atrial septal defect exhibited an intragenic deletion of exon 6. Another KS patient with cryptorchidism had intragenic deletions of exons 5 and 6. For the nIHH patients, no abnormalities were observed in the exonic and flanking sequences of KAL-1. This report describes two intragenic deletions of KAL-1 in two KS patients and suggests that KAL-1 deletion might be more prevalent in KS patients with other congenital organ abnormalities than those described previously in other series from Northwestern China.


Assuntos
Proteínas da Matriz Extracelular/genética , Hipogonadismo/genética , Síndrome de Kallmann/genética , Proteínas do Tecido Nervoso/genética , Adolescente , Adulto , China , Deleção de Genes , Humanos , Masculino
8.
BMC Neurosci ; 9 Suppl 2: S10, 2008 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-19090983

RESUMO

Tau aggregation is one of the major features in Alzheimer's disease and in several other tauopathies, including frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17), and progressive supranuclear palsy (PSP). More than 35 mutations in the tau gene have been identified from FTDP-17 patients. A group of these mutations alters splicing of exon 10, resulting in an increase in exon 10 inclusion into tau mRNA. Abnormal splicing with inclusion of exon 10 into tau mRNA has also been observed in PSP and AD patients. These results indicate that abnormal splicing of exon 10, leading to the production of tau with exon 10, is probably one of the mechanisms by which tau accumulates and aggregates in tauopathic brains. Therefore, modulation of exon 10 splicing in the tau gene could potentially be targeted to prevent tauopathies. To identify small molecules or compounds that could potentially be developed into drugs to treat tauopathies, we established a cell-based high-throughput screening assay. In this review, we will discuss how realistic, specific biological molecules can be found to regulate exon 10 splicing in the tau gene for potential treatment of tauopathies.


Assuntos
Processamento Alternativo/genética , Tauopatias/genética , Proteínas tau/genética , Processamento Alternativo/efeitos dos fármacos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Demência/tratamento farmacológico , Demência/genética , Demência/patologia , Éxons/genética , Humanos , Mutação , Oligorribonucleotídeos Antissenso/genética , Oligorribonucleotídeos Antissenso/uso terapêutico , Tauopatias/tratamento farmacológico , Tauopatias/patologia
9.
J Gastroenterol Hepatol ; 23(7 Pt 2): e258-64, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17944888

RESUMO

BACKGROUND AND AIM: Tissue-type plasminogen activator (tPA) is one of the major components in the matrix proteolytic network whose role in the pathogenesis of liver fibrosis remains unknown. The aim of this study is to investigate the role of tPA in carbon tetrachloride (CCl(4))-induced liver fibrosis. METHODS: Wild-type and tPA knockout mice (8 mice per group) were injected interperitoneumly with 25% CCl(4) 2 ml/kg twice per week as CCl(4) administration groups and olive oil 2 ml/kg as controls. After 4 weeks, the livers of mice were removed under deep anesthesia and prepared for further studies such as histology, immunostaining, hydroxyproline assay, zymography and western blot analysis. RESULTS: Mice lacking tPA developed more severe morphological injury and displayed an increased deposition of collagen in the liver after CCl(4) administration compared with wild-type counterparts. Deficiency of tPA increased alpha-smooth muscle actin expression in the mice livers. On the other hand, the decrease of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) activities, metalloproteinase-13 (MMP-13) expression and a marked increase of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) expression were found in the liver of CCl(4) administrated tPA(-/-) mice compared with wild-type counterparts. CONCLUSIONS: Deficiency of tPA aggravated liver fibrosis through promoting hepatic stellate cells (HSCs) activation and inhibiting ECM degradation by decreasing MMP-2, MMP-9 activities and disrupting the balance between MMP-13 and TIMP-1.


Assuntos
Cirrose Hepática/metabolismo , Fígado/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Actinas/metabolismo , Animais , Tetracloreto de Carbono , Colágeno/metabolismo , Modelos Animais de Doenças , Fígado/enzimologia , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/genética , Cirrose Hepática/patologia , Masculino , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Índice de Gravidade de Doença , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Ativador de Plasminogênio Tecidual/deficiência , Ativador de Plasminogênio Tecidual/genética
10.
Chem Biol ; 14(12): 1386-92, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18096507

RESUMO

Exon 2 of the Bcl-x gene undergoes alternative splicing in which the Bcl-xS splice variant promotes apoptosis in contrast to the anti-apoptotic splice variant Bcl-xL. In this study, the regulation of the alternative splicing of pre-mRNA of Bcl-x was examined in response to emetine. Treatment of different types of cancer cells with emetine dihydrochloride downregulated the level of Bcl-xL mRNA with a concomitant increase in the mRNA level of Bcl-xS in a dose- and time-dependent manner. Pretreatment with calyculin A, an inhibitor of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A), blocked emetine-induced alternative splicing in contrast to okadaic acid, a specific inhibitor of PP2A in cells, demonstrating a PP1-mediated mechanism. Our finding on the regulation of RNA splicing of members of the Bcl-2 family in response to emetine presents a potential target for cancer treatment.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Emetina/farmacologia , Proteína Fosfatase 1/metabolismo , Proteína bcl-X/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cicloeximida/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Inibidores Enzimáticos/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Toxinas Marinhas , Ácido Okadáico/farmacologia , Oxazóis/farmacologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteína Fosfatase 1/antagonistas & inibidores , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
11.
Biochem Biophys Res Commun ; 364(4): 850-5, 2007 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-17964281

RESUMO

Deletion or mutation of the survival of motor neuron (SMN1) gene causes Spinal Muscular Atrophy (SMA), a motor neuron degenerative disease. To study the SMN function, we co-transfected mouse NSC34 cells with SMN and mutant superoxide dismutase 1 (SOD1) constructs. We demonstrated that SMN protected NSC34 cells against cell death induced by mutant SOD1 under oxidative stress. Further studies indicated that over-expression of wild-type SMN up-regulated chaperone activity. In contrast, chaperone activity was decreased in cells expressing SMN mutant Y272C or in cells with SMN suppressed by shRNA. In vitro assays using bacteria lysates expressing GST-SMN or purified GST-SMN protein showed that the GST-SMN reduced catalase aggregation, indicating that SMN may possess chaperone activity. We conclude that SMN plays a protective role in motor neurons by its chaperone activity. Our results provide support for the potential development of therapy for SMA and amyotrophic lateral sclerosis (ALS).


Assuntos
Apoptose , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuroblastoma/metabolismo , Proteínas de Ligação a RNA/metabolismo , Superóxido Dismutase/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular , Citoproteção , Camundongos , Proteínas do Complexo SMN , Superóxido Dismutase-1 , Proteína 1 de Sobrevivência do Neurônio Motor
12.
Biochem Biophys Res Commun ; 349(3): 906-12, 2006 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-16978586

RESUMO

Tissue plasminogen activator (tPA) is an essential component of the proteolytic cascade that lyses blood clots. Various studies also suggest that tPA plays important roles in peripheral nerve regeneration. Here we show that disruption of tPA gene reduces macrophage migration after sciatic nerve injury in mice. Moreover, lack of tPA activity attenuates migrating ability of macrophages and affects MMP-9 expression and activity in macrophages in vitro. Addition of ethylenediaminetetraacetic acid (EDTA), which inhibits MMPs, abolished the differences of migration ability of macrophages between tPA(+/+) and tPA(-/-) mice. Axonal regeneration is correlated with the increase of macrophage migration, suggesting that tPA may help create a beneficial environment for axonal regeneration through promoting macrophage infiltration. This study shows that tPA may play a role in nerve regeneration through regulating the migration ability of macrophages. This function of tPA may depend on, at least in part, upregulating MMP-9 expression and activity in macrophages.


Assuntos
Movimento Celular , Macrófagos/citologia , Macrófagos/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Regulação para Baixo , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Masculino , Metaloproteinase 9 da Matriz/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Bainha de Mielina/metabolismo , Degeneração Neural/genética , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Neurônios/citologia , Neurônios/metabolismo , Ativador de Plasminogênio Tecidual/deficiência , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/farmacologia
13.
J Neuropathol Exp Neurol ; 65(1): 78-86, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16410751

RESUMO

Tissue plasminogen activator (tPA) is an essential component of the proteolytic cascade that lyses blood clots. Various studies also suggest that tPA plays important roles in the nervous system. We show that exogenous tPA or tPA/plasminogen (plg) promotes axonal regeneration, remyelination, and functional recovery after sciatic nerve injury in the mouse. Local application of tPA or tPA/plg 7 days after sciatic nerve crush significantly increased the total number of axons and myelinated axons, which is accompanied by enhanced expression of neurofilament. Treatment with tPA or tPA/plg reduced the deposition of fibrin(ogen) after nerve injury. Moreover, tPA or tPA/plg increased the number of macrophages and induced MMP-9 expression at the injury site, coincident with reduced collagen scar formation and accelerated clearance of myelin and lipid debris after treatment. Consequently, tPA or tPA/plg treatment protected muscles from atrophy after nerve injury, indicating better functional recovery. These results suggest that administration of exogenous tPA or tPA/plg promotes axonal regeneration and remyelination through removal of fibrin deposition and activation of MMP-9-positive macrophages, which may be responsible for myelin debris clearance and preventing collagen scar formation. Therefore, tPA may be useful for treatment of peripheral nerve injury.


Assuntos
Regeneração Nervosa/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Neuropatia Ciática/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Animais , Antígenos de Diferenciação/metabolismo , Compostos Azo , Western Blotting/métodos , Contagem de Células/métodos , Modelos Animais de Doenças , Interações Medicamentosas , Imunoglobulina G/metabolismo , Imuno-Histoquímica/métodos , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Atrofia Muscular/tratamento farmacológico , Atrofia Muscular/etiologia , Atrofia Muscular/patologia , Bainha de Mielina/metabolismo , Fibras Nervosas Mielinizadas/efeitos dos fármacos , Fibras Nervosas Mielinizadas/metabolismo , Fibras Nervosas Mielinizadas/patologia , Plasminogênio/administração & dosagem , Neuropatia Ciática/complicações , Neuropatia Ciática/metabolismo
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