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1.
Nature ; 579(7798): 284-290, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32103175

RESUMO

Cancer recurrence after surgery remains an unresolved clinical problem1-3. Myeloid cells derived from bone marrow contribute to the formation of the premetastatic microenvironment, which is required for disseminating tumour cells to engraft distant sites4-6. There are currently no effective interventions that prevent the formation of the premetastatic microenvironment6,7. Here we show that, after surgical removal of primary lung, breast and oesophageal cancers, low-dose adjuvant epigenetic therapy disrupts the premetastatic microenvironment and inhibits both the formation and growth of lung metastases through its selective effect on myeloid-derived suppressor cells (MDSCs). In mouse models of pulmonary metastases, MDSCs are key factors in the formation of the premetastatic microenvironment after resection of primary tumours. Adjuvant epigenetic therapy that uses low-dose DNA methyltransferase and histone deacetylase inhibitors, 5-azacytidine and entinostat, disrupts the premetastatic niche by inhibiting the trafficking of MDSCs through the downregulation of CCR2 and CXCR2, and by promoting MDSC differentiation into a more-interstitial macrophage-like phenotype. A decreased accumulation of MDSCs in the premetastatic lung produces longer periods of disease-free survival and increased overall survival, compared with chemotherapy. Our data demonstrate that, even after removal of the primary tumour, MDSCs contribute to the development of premetastatic niches and settlement of residual tumour cells. A combination of low-dose adjuvant epigenetic modifiers that disrupts this premetastatic microenvironment and inhibits metastases may permit an adjuvant approach to cancer therapy.


Assuntos
Epigênese Genética , Terapia Genética , Células Supressoras Mieloides/fisiologia , Neoplasias/terapia , Microambiente Tumoral , Animais , Azacitidina/farmacologia , Benzamidas/farmacologia , Diferenciação Celular , Movimento Celular/efeitos dos fármacos , Quimioterapia Adjuvante , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Camundongos , Células Supressoras Mieloides/citologia , Metástase Neoplásica/terapia , Neoplasias/cirurgia , Piridinas/farmacologia , Receptores CCR2/genética , Receptores de Interleucina-8B/genética , Microambiente Tumoral/efeitos dos fármacos
2.
Clin Immunol ; 212: 108345, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31953149

RESUMO

BACKGROUND: Biomarkers in non-colorectal gastrointestinal (GI) cancer patients receiving immune checkpoint blockades (ICBs) are still limited. METHODS: Data were prospectively collected from a discovery cohort (n = 53) and a validation cohort (n = 107) in patients with non-colorectal GI cancer receiving ICB, as well as a chemotherapy-only cohort (n = 171). System inflammatory markers and derived neutrophil-to-lymphocyte ratio (dNLR) were determined as biomarkers by univariate and multivariate analyses. RESULTS: A higher level of dNLR (cutoff = 3) was associated with shorter overall survival (OS) in discovery and validation cohorts. In pooled cohort, disease control rate (DCR) (28% vs. 48.1%) was associated with dNLR (p = .017). In univariate analysis, original tumor site, tumor histopathology, number of metastases, and dNLR were correlated with OS. In multivariate analysis, higher dNLR level was correlated with reduced OS (10.43 months vs. 4.20 months, p < .001). In chemotherapy-only cohort, dNLR was also correlated with DCR and OS. CONCLUSION: Higher dNLR level was correlated with worse outcomes, suggesting that dNLR may help risk-group stratification and assist disease management strategies as a prognostic biomarker for non-colorectal GI patients receiving ICB.

3.
J Struct Biol ; 208(1): 69-76, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419523

RESUMO

Plant cytokinins (CKs) are essential for many central cellular processes and play important roles in the interaction between bacteria and plants. Perception of CK is executed by the CHASE domain in the histidine kinase sensors of a class of two-component regulatory systems. Despite advances in understanding the structural basis for CK perception by the sensor AHK4 in Arabidopsis, the molecular mechanism of CK binding by other sensors is unclear. Here, we report the crystal structure of the CHASE domain in the histidine kinase PcrK of the bacterial plant pathogen Xanthomonas campestris pathovar campestris, which senses plant CK, determined at 2.55 Šresolution. The structure reveals that the PcrK has an AHK4-like overall topology and assembles into a homodimer. Strikingly, detailed structural analysis unveils two unique features of the PcrK ligand binding pocket: the size of the pocket is restricted for CK binding, and the PcrK applies a positively charged arginine but not a negatively charged aspartate to recognize the ligand. We propose a model to explain how the PcrK accommodates CK-sized compounds through conformational changes, providing a potential mechanistic framework for understanding ligand recognition by the PcrK.

4.
Br J Radiol ; 91(1092): 20180580, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30160183

RESUMO

OBJECTIVES:: To investigate the use of shortened contrast injection with late triggering in coronary CT angiography (CCTA) for decreasing contrast dose and maintaining image quality. METHODS:: 106 patients for CCTA on a 16-cm wide-detector CT were prospectively enrolled into groups A (n = 50) and B (n = 56) randomly. Patient weight-dependent contrast medium (Iopamiro, 370 mgI ml-1) at dose rate of 25 mgI/kg/s was used with 8 s and the standard 10 s injection time in groups A and B, respectively. CT values of the aortic sinus (AS), right coronary artery, left anterior descending and left circumflex at the proximal, middle and distal segments were measured and compared. Subjective image quality was evaluated and analyzed with Fisher exact test. Contrast dose, injection rate and enhancement duration (between the start of enhancement in AS and scan finish) were also compared. RESULTS:: There was no difference in the injection rate and enhancement duration between the two groups (p > 0.05), while the total contrast dose in group A (36.2 ± 5.7 ml) was significantly lower than in group B (46.4 ± 6.3 ml) (p < 0.001). There was no difference for CT values in all major coronary vessels between the two groups and no difference in subjective image quality scores (all p > 0.05). CONCLUSION:: It is feasible to shorten contrast injection to 8 s in CCTA on wide-detector CT systems to significantly reduce contrast dosage, maintain adequate enhancement and reduce contrast-related artifacts. ADVANCES IN KNOWLEDGE:: (1) Coronary CT angiography (CCTA) scans with shortened contrast medium injection duration and late triggering are feasible with a 16-cm wide-detector CT system (2) Compared with the conventional CCTA with 10 s contrast injection duration, the new contrast injection protocol of using shortened injection duration (to 8 s) and late triggering reduces contrast dose to 36.2 ml, while maintaining adequate enhancement in vessels and reducing contrast-related artifacts.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Iopamidol/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Artefatos , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
World J Gastroenterol ; 24(2): 266-273, 2018 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-29375212

RESUMO

AIM: To investigate predictive and prognostic value of serum alpha-fetoprotein (AFP) level and its dynamic changes in patients with advanced gastric cancer with elevated serum AFP (AFPAGC). METHODS: One hundred and five patients with AFPAGC were enrolled in the study, and all of them underwent at least one cycle of systemic chemotherapy at our institute and had serum AFP ≥ 20 ng/mL at diagnosis or recurrence. Clinicopathologic features, serum AFP level at diagnosis and changes during treatment, first-line chemotherapy regimens, efficacy and toxicity, and survival information were collected. A Person's χ2 or Fisher's exact test was used to measure the differences between variables. Survival prognostic factors were investigated using the Kaplan-Meier method and Cox regression. RESULTS: Median serum AFP level was 161.7 ng/mL (range, 22.9-2557110 ng/mL). Objective response rates (ORR) was significantly lower in the AFP ≥ 160 ng/mL group than in the AFP < 160 ng/mL group (30.4% vs 68.3%, P < 0.001). ORR to doublet regimens was significantly lower in the AFP ≥ 160 ng/mL group, whereas ORR to triplet regimens was similar between the two groups. Liver metastasis rate was significantly higher in the AFP ≥ 160 ng/mL group than in the AFP < 160 ng/mL (69.8% vs 50.0%, P < 0.001). Overall survival (OS) in the two cohorts did not show any significant difference (P = 0.712). Dynamic changes of AFP were consistent with response to chemotherapy, and median OS of patients with a serum AFP decline ≥ 50% and those with a serum AFP decline < 50% was 17.5 m and 10.0 m, respectively (P = 0.003). Hepatic (P = 0.005), peritoneal (P < 0.001), non-regional lymph node metastasis (P < 0.001), and portal vein tumor thrombus (PVTT) (P = 0.042) were identified as independent prognostic factors for AFPAGC. CONCLUSION: Real-time examination of AFP has great predictive and prognostic value for managing AFPAGC. For those with markedly elevated AFP, triplet regimens may be a better choice.


Assuntos
Adenocarcinoma/sangue , Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/sangue , Neoplasias Gástricas/tratamento farmacológico , alfa-Fetoproteínas/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Distribuição de Qui-Quadrado , Tomada de Decisão Clínica , Progressão da Doença , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/secundário , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Seleção de Pacientes , Neoplasias Peritoneais/secundário , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Fatores de Tempo , Resultado do Tratamento , Regulação para Cima
6.
J Mot Behav ; 50(3): 343-352, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28915098

RESUMO

The authors' aim was to find the features of balance, proprioception, and gross motor development of Chinese children 3-6 years old and their correlations, provide theoretical support for promoting children's motor development, and enrich the world theoretical system of motor development. This study used a Tekscan foot pressure measurement instrument (Tekscan, Inc., Boston, MA), walking on a balance beam, Xsens 3-dimensional positional measuring system (Xsens Technologies, Enschede, the Netherlands), and Test of Gross Motor Development-2 to assess static balance, dynamic balance, knee proprioception, and levels of gross motor development (GMD) of 3- to 6-year-old children (n = 60) in Beijing. The results are as follows: children had significant age differences in static balance, dynamic balance, proprioception, and levels of GMD; children had significant gender differences in static balance, proprioception, and levels of GMD; children's static balance, dynamic balance, and proprioception had a very significant positive correlation with GMD (p < .01), but no significant correlation with body mass index.


Assuntos
Desenvolvimento Infantil/fisiologia , Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Joelho , Masculino , Caracteres Sexuais , Caminhada
7.
Biochem Biophys Res Commun ; 477(4): 548-555, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27297106

RESUMO

Vascular endothelial dysfunction, a central hallmark of diabetes, predisposes diabetic patients to numerous cardiovascular complications. The POZ/BTB and AT-hook-containing zinc finger protein 1 (PATZ1), is an important transcriptional regulatory factor and regulates divergent pathways depending on the cellular context, but its role in endothelial cells remains poorly understood. Herein, we report for the first time that endothelial PATZ1 expression was abnormally upregulated in diabetic endothelial cells (ECs) regardless of diabetes classification. This stimulatory effect was further confirmed in the high glucose-treated human umbilical vein endothelial cells (HUVECs). From a functional standpoint, transgenic overexpression of PATZ1 in endothelial colony forming cells (ECFCs) blunted angiogenesis in vivo and rendered endothelial cells unresponsive to established angiogenic factors. Mechanistically, PATZ1 acted as a potent transcriptional corepressor of fatty acid-binding protein 4 (FABP4), an essential convergence point for angiogenic and metabolic signaling pathways in ECs. Taken together, endothelial PATZ1 thus potently inhibits endothelial function and angiogenesis via inhibition of FABP4 expression, and abnormal induction of endothelial PATZ1 may contribute to multiple aspects of vascular dysfunction in diabetes.


Assuntos
Proteínas de Ligação a Ácido Graxo/metabolismo , Hiperglicemia/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Animais , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Glucose/administração & dosagem , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
8.
Sheng Li Ke Xue Jin Zhan ; 46(3): 170-4, 2015 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-26521480

RESUMO

Neurotrophic factor is a kind of protein family that plays an important role in the nutrition, support and differentiation to central neurons as well as synaptic plasticity. Growing evidences have revealed that pro-forms of various neurotrophic factors, which are generated in process of protein synthesis and might exert opposite roles involving in inducement of neuronal apoptosis and implication in pathogenesis of neurodegenerative diseases. This paper reviews "Yin/Yang" features of neurotrophic factors in the anabolism, receptor regulation, functional aspects, and their related role in pathogenesis of neurodegenerative diseases. It is hopefully to provide new idea on understanding and investigation of the neurotrophic factors regarding on their functional, pathological and potential therapeutic significance.


Assuntos
Neurônios , Apoptose , Humanos , Fatores de Crescimento Neural , Doenças Neurodegenerativas , Plasticidade Neuronal
9.
Stem Cell Res ; 9(2): 156-66, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22771389

RESUMO

Recent studies demonstrated that mature atrocytes have the capacity for de-differentiating into neural stem/progenitor cells (NSPCs) in vitro and in vivo. However, it is still unknown what signals endow astroglial cells with a de-differentiation potential. Furthermore, the signaling molecules and underlying mechanism that confer astrocytes with the competence of NSPC phenotypes have not been completely elucidated. Here, we found that sonic hedgehog (Shh) production in astrocytes following mechanical injury was significantly elevated, and that incubation of astrocyes with the injured astrocyte conditioned medium (ACM) causes astrocytes to gradually lose their immunophenotypical profiles, and acquire NSPC characteristics, as demonstrated by down-regulation of typical astrocytic markers (GFAP and S100) and up-regulation of markers that are generally expressed in NSCs, (nestin, Sox2, and CD133). ACM treated astrocytes exhibit self-renewal capacity and multipotency similar to NSPCs. Concomitantly, in addition to Ptc, there was a significant up-regulation of the Shh downstream signal components Gli2 and Cyclin D1 which are involved in cell proliferation, dramatic changes in cell morphology, and the disruption of cell-cycle G1 arrest. Conversely, the depletion of Shh by administration of its neutralizing antibody (Shh n-Ab) effectively inhibited the de-differentiation process. Strikingly, Shh alone had little effect on astrocyte de-differentiation to NSPCs. These data above suggest that Shh is a key instructive molecule while other molecules secreted from insulted astrocytes may synergistically promote the de-differentiation event.


Assuntos
Astrócitos/metabolismo , Astrócitos/patologia , Desdiferenciação Celular , Proteínas Hedgehog/metabolismo , Transdução de Sinais , Animais , Astrócitos/efeitos dos fármacos , Biomarcadores/metabolismo , Desdiferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Ciclina D1/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Receptores Patched , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Esferoides Celulares/citologia , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Estresse Mecânico , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Regulação para Cima/efeitos dos fármacos , Proteína Gli2 com Dedos de Zinco
10.
Neurochem Int ; 61(2): 175-86, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22561407

RESUMO

It has long been promulgated that microglial cells serve beneficial roles in the central nervous system (CNS). The beneficial role of microglial cells is considered to be linked with microglial activation and consequent up-regulation of various trophic factors. However, what triggers microglial activation and consequent elevated level of trophic factors, especially brain-derived neurotrophic factor (BDNF), following traumatic CNS injury has become a crucial but elusive issue. Furthermore, an effort still remains in understanding of the cellular and molecular mechanisms underlying the endogenous neuroprotection of activated microglial cells. In this study, we demonstrated that mechanically-injured astrocyte conditioned medium (ACM) could provoke beneficial activation of microglial cells and thus promote the transcription, synthesis and release of BDNF in cultured microglial cells. The microglia-derived BDNF can exerted a demonstrable biological role in promoting neurite outgrowth and intimate terminal contacts of dorsal root ganglion (DRG) neurons co-cultured with microglial cells. Moreover, ACM induced remarkable p38MAPK phosphorylation in cultured microglial cells that preceded the burst of BDNF. Activating p38-MAPK by anisomycin resulted in salutary effects similar to those seen with ACM, whereas specific inhibition of the p38MAPK by SB203580 abrogated all the positive effects of ACM, including BDNF promotion and subsequent neurite outgrowth of DRG neurite outgrowth of DRG neurons and their intimate terminal contacts with microglial cells. Together, our results indicated that the neuroprotection of the microglial source is mainly caused by micro-environmental soluble molecules released from injured astrocytes, and ACM-induced BDNF production and release from microglial cells may be mediated through p38-MAPK signaling pathway. Therefore, these findings may lay a foundation to further investigations on the microglial beneficial activation role in the repair of traumatic CNS injury and neurodegenerative diseases.


Assuntos
Astrócitos/fisiologia , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Ativação de Macrófagos/fisiologia , Microglia/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Animais , Western Blotting , Células Cultivadas , Imunofluorescência , Gânglios Espinais/crescimento & desenvolvimento , Gânglios Espinais/fisiologia , Microglia/fisiologia , Neuritos/fisiologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia , Medula Espinal/citologia , Estresse Mecânico , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
11.
Restor Neurol Neurosci ; 30(4): 335-43, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22614954

RESUMO

PURPOSE: To compare neuroprotection and therapeutic time windows of two diazepam regimens on retinal ganglion cells (RGCs) after rat optic nerve transection (ONT). METHODS: Adult rats received initial intraperitoneal diazepam injections 30 minutes before left ONT, followed by daily diazepam (regimen-A) or every 8 hours for 3 days (regimen-B) until they were killed at day 7 or 14. Initial diazepam in regimen-A and regimen-B was delayed to 3, 6, 7, 9, 10, 12 and 6, 7, 8, 9, 10, 12 hours after ONT and these animals survived for 7 days. The effect of daily combinational uses of diazepam and bicuculline was assayed at 7 days. RESULTS: Regimen-A induced higher RGC densities than those in control and regimen-B groups at day 7, but lower density than regimen-B did at day 14. When initial diazepam was delayed beyond 6 or 8 hours after ONT with regimen-A and regimen-B, the promoting effects of diazepam on RGC densities disappeared. Bicuculline completely inhibited the protection of diazepam. CONCLUSIONS: Prolonged neuroprotection on RGCs at day 14 and extended therapeutic time window for 8 hours can be achieved by regimen-B, while regimen-A induces a stronger neuroprotection at day 7. Diazepam neuroprotection is mediated through GABAA receptor.


Assuntos
Diazepam/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Traumatismos do Nervo Óptico/tratamento farmacológico , Células Ganglionares da Retina/efeitos dos fármacos , Envelhecimento , Animais , Axotomia/efeitos adversos , Contagem de Células/métodos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Injeções Intraperitoneais/métodos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
12.
Neurochem Res ; 36(10): 1759-66, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21562748

RESUMO

Tyrosine kinase receptors TrkB and TrkC mediate neuroprotective effects of the brain-derived neurotrophic factor (BDNF) and neurotrophins in the dopaminergic nigro-striatal system, but it is obscure about their responses or expression changes in the injured substantia nigra under Parkinson's disease. In present study, immunofluorescence, Fluoro-Jade staining and laser scanning confocal microscopy were applied to investigate distribution and changes of TrkB and TrkC in the dopamine neurons of the substantia nigra by comparison of control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model. It revealed that TrkB and TrkC-immunoreactivities were substantially localized in cytoplasm and cell membrane of the substantia nigra neurons of control adults. While neurons double-labeled with tyrosine hydroxylase (TH)/TrkB, or TH/TrkC were distributed in a large numbers in the substantia nigra of controls, they apparently went down at 36.2-65.7% of normal level, respectively following MPTP insult. In MPTP model, cell apoptosis or degeneration of nigral neurons were confirmed by caspase-3 and Fluoro-Jade staining. More interestingly, TH/TrkB-positive neurons survived more in cell numbers in comparison with that of TH/TrkC-positive ones in the MPTP model. This study has indicated that TrkB-containing dopamine neurons are less sensitive in the substantia nigra of MPTP mouse model, suggesting that specific organization of Trks may be involved in neuronal vulnerability to MPTP insult, and BDNF-TrkB signaling may play more important role in protecting dopamine neurons and exhibit therapeutic potential for Parkinson's disease.


Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Dopaminérgicos/toxicidade , Neurônios Dopaminérgicos/metabolismo , Intoxicação por MPTP/metabolismo , Neurotoxinas/toxicidade , Receptor trkB/metabolismo , Receptor trkC/metabolismo , Substância Negra/patologia , Animais , Modelos Animais de Doenças , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Humanos , Intoxicação por MPTP/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Distribuição Aleatória , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
13.
Cell Transplant ; 19(2): 159-66, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20350358

RESUMO

Intraorbital transection of the optic nerve (ON) always induces ultimate apoptosis of retinal ganglion cells (RGCs) and consequently irreversible defects of vision function. It was demonstrated that transplanted olfactory ensheathing cells (OECs) in partially injured spinal cord have a distant in vivo neuroprotective effect on descending cortical and brain stem neurons. However, this study gave no answers to the question whether OECs can protect the central sensitive neurons with a closer axonal injury because different neurons respond variously to similar axonal injury and the distance between the neuronal soma and axonal injury site has a definite effect on the severity of neuronal response and apoptosis. In the present study, we investigated the effect of transplanted OECs on RGCs after intraorbital ON transection in adult rats. Green fluorescent protein (GFP)-OECs were injected into the ocular stumps of transected ON and a significantly higher number of surviving RGCs was found together with a consistent marked increase in the mRNA and protein levels of BDNF in the ON stump and retina in the OEC-treated group at 7 days, but not 2 and 14 days, time point when compared to the control group. Our findings suggest that OEC transplantation induces the expression of BDNF in the ocular ON stump and retina and delays the death of axotomized RGCs at a certain survival period.


Assuntos
Axotomia , Morte Celular/fisiologia , Neuroglia/transplante , Condutos Olfatórios/citologia , Traumatismos do Nervo Óptico/cirurgia , Células Ganglionares da Retina/fisiologia , Animais , Sobrevivência Celular , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neuroglia/citologia , Neuroglia/fisiologia , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Células Ganglionares da Retina/citologia
14.
Cell Mol Neurobiol ; 30(3): 483-91, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19885729

RESUMO

Our previous study definitely demonstrated that the mature astrocytes could undergo a de-differentiation process and further transform into pluripotential neural stem cells (NSCs), which might well arise from the effect of diffusible factors released from scratch-insulted astrocytes. However, these neurospheres passaged from one neurosphere-derived from de-differentiated astrocytes possessed a completely distinct characteristic in the differentiation behavior, namely heterogeneity of differentiation. The heterogeneity in cell differentiation has become a crucial but elusive issue. In this study, we show that purified astrocytes could de-differentiate into intermediate precursor cells (IPCs) with addition of scratch-insulted astrocyte-conditioned medium (ACM) to the culture, which can express NG2 and A2B5, the IPCs markers. Apart from the number of NG2(+) and A2B5(+) cells, the percentage of proliferative cells as labeled with BrdU progressively increased with prolonged culture period ranging from 1 to 10 days. Meanwhile, the protein level of A2B5 in cells also increased significantly. These results revealed that not all astrocytes could de-differentiate fully into NSCs directly when induced by ACM, rather they generated intermediate or more restricted precursor cells that might undergo progressive de-differentiation to generate NSCs.


Assuntos
Astrócitos/metabolismo , Desdiferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Regeneração Nervosa/fisiologia , Células-Tronco Pluripotentes/metabolismo , Animais , Antígenos/metabolismo , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Biomarcadores/metabolismo , Bromodesoxiuridina , Técnicas de Cultura de Células , Desdiferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Gangliosídeos/metabolismo , Regeneração Nervosa/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Proteoglicanas/metabolismo , Ratos , Regulação para Cima/fisiologia
15.
Cell Mol Neurobiol ; 30(1): 149-60, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19688260

RESUMO

Thymosin-beta4 (Tbeta4) is a major actin monomer-binding peptide in mammalian tissues and plays a crucial role in the nervous system in synaptogenesis, neuronal survival and migration, axonal growth, and plastic changes of dendritic spines. However, it is unknown whether Tbeta4 is also involved in challenges with external stress such as ethanol-induced neurotoxicity. In the present study, we investigated the effects of Tbeta4 on ethanol-induced neurotoxicity in cultured cerebral cortical astrocytes and the underlying mechanisms. Primarily cultured astrocytes were treated with 1 microg/ml Tbeta4 2 h prior to administration of 100 mM ethanol for 0.5, 1, 3 and 6 days, respectively. The results showed that ethanol caused neurotoxicity in cultured astrocytes, as shown by declined cell viability, distinct astroglial apoptosis and increased intracellular peroxidation. Tbeta4 markedly promoted cell viability, ameliorated the injury of intracellular glial fibrillary acidic protein-immunopositive cytoskeletal structures, reduced the percentage of apoptotic astrocyte and cellular DNA fragmentation, suppressed caspase-3 activity and upregulated Bcl-2 expression, inhibited the accumulation of reactive oxygen species and production of malondialdehyde in ethanol-treated astrocytes in a time-dependent manner. These data indicated that Tbeta4 attenuates ethanol-induced neurotoxicity in cultured cortical astrocytes through inhibition of apoptosis signaling, and one of the mechanisms underlying the capacity of Tbeta4 to suppress apoptosis may in part be due to its effect of anti-peroxidation.


Assuntos
Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Córtex Cerebral/patologia , Síndromes Neurotóxicas/patologia , Timosina/farmacologia , Animais , Astrócitos/enzimologia , Caspase 3/metabolismo , Contagem de Células , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/patologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Etanol , Proteína Glial Fibrilar Ácida/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos
16.
Wei Sheng Wu Xue Bao ; 48(3): 299-303, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18479054

RESUMO

UNLABELLED: The virulence of Listeria monocytogenes is directly related to its ability to spread from cell to cell without leaving the intracellular milieu. Among the bacterial factors involved in cell-to-cell spread, actin-polymerizing protein ActA is required for bacterial spread to adjacent cells, while the broad-range phospholipase C (PC-PLC) contributes to bacterial escape from secondary vacuoles. METHODS: Based on homologous recombination technology, we constructed a double gene-mutant strain by deleting two virulence factors, ActA and PC-PLC. OBJECTIVE: Its toxicity and immunopotency was evaluated in murine model. RESULTS: And then, the mutant strain was further verified the absence of ActA and PC-PLC using Western blot analysis and phospholipase activity assay. It showed highly attenuated and its 50% lethal dose in BLAB/c mice was increased at least 10(3)-fold compared to the parent strain. Nevertheless, mice preimmunized with the mutant strain elicited strong T-cell responses and fully protected against a lethal challenge with the virulent strain. CONCLUSION: These results not only verified that ActA and PC-PLC were essential virulence factors for L. monocytogenes, but also demonstrated that the mutant strain possessed good immunogenicity with higher safety. The mutant strain could be further studied as a vaccine candidate to prevent listeriosis and used as a vector to deliver heterologous antigens. Furthermore, it provided the possibilities to elucidate the molecular mechanisms of pathogenesis and immune response triggered by L. monocytogenes.


Assuntos
Proteínas de Bactérias/genética , Deleção de Genes , Listeria monocytogenes/genética , Proteínas de Membrana/genética , Fosfolipases Tipo C/genética , Animais , Vacinas Bacterianas , Western Blotting , DNA Recombinante/genética , Dose Letal Mediana , Listeria monocytogenes/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase , Baço/imunologia , Subpopulações de Linfócitos T/metabolismo , Fatores de Virulência/genética
17.
Life Sci ; 79(20): 1895-905, 2006 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-16978658

RESUMO

The enhanced production of nitric oxide (NO) via inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of neuronal apoptosis after acute traumatic spinal cord injury (SCI). In the present study, to further characterize the pathways mediating the synthesis and release of NO, we examined activation of extracellular signal regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinases (p38 MAPK) in microglia/macrophages in the injured area of adult rats subjected to a complete transection at the T10 vertebrae level and assessed their role in NO production and survival of neurons by using immunohistochemistry, Western blot, RT-PCR and pharmacological interventions. Results showed activation of microglia/macrophages featured by morphological changes, as visualized immunohistochemically with the marker OX-42, in the areas adjacent to the lesion epicenter 1 h after surgery. Concomitantly, iNOS mRNA and its protein in the activated microglia/macrophages were also significantly upregulated at early hours after surgery. Their levels were maximal at 6 h, persisted for at least 24 h, and returned to basal level 72 h after SCI. Furthermore, phosphorylated ERK1/2 and p38 MAPK were activated as well in microglia/macrophages in injured area with a similar time course as iNOS. With administration of L-NAME, a NOS inhibitor, the number of apoptotic neurons was clearly decreased, as assessed with TUNEL method at 24 h after SCI. In parallel, loss of neurons induced by SCI, assessed with NeuN immunohistochemistry, was also diminished. Moreover, the effect of inhibition of phosphorylation ERK1/2 and p38 MAPK by corresponding inhibitors PD98059 and SB203580 administered before and after SCI was also investigated. Inhibition of p38 effectively reduced iNOS mRNA expression and rescued neurons from apoptosis and death in the area adjacent to the lesion epicenter; whereas the inhibition of ERK1/2 had a smaller effect on decrease of iNOS mRNA and no long-term protective effect on cell loss. These results indicate the ERK1/2 and p38 MAPK signaling pathway, especially the latter, play an important role in NO-mediated degeneration of neuron in the spinal cord following SCI. Strategies directed to blocking the initiation of this cascade prove to be beneficial for the treatment of acute SCI.


Assuntos
Ativação de Macrófagos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Degeneração Neural/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Traumatismos da Medula Espinal/enzimologia , Traumatismos da Medula Espinal/patologia , Animais , Macrófagos/enzimologia , Macrófagos/imunologia , Masculino , Microglia/imunologia , Proteína Quinase 1 Ativada por Mitógeno/análise , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/análise , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/análise , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Neurônios/enzimologia , Neurônios/patologia , Óxido Nítrico Sintase Tipo II/análise , Óxido Nítrico Sintase Tipo II/genética , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/análise , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
18.
Zhonghua Xue Ye Xue Za Zhi ; 27(4): 254-8, 2006 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-16875558

RESUMO

OBJECTIVE: To investigate the effects of curcumin (Cur) and erythromycin (EM) on multidrug resistance (MDR) reversal of K562/A02 cell line and their mechanism. METHODS: MTT assay was employed to determine the sensitivity of Cur, EM-treated K562/A02 cells to adriamycin (ADM). Flow cytometry was used to measure intracellular mean fluorescence intensity (MFI) of daunorubicin (DNR). P-gp expression was determined by immunohistochemistry. RT-PCR technique was used to examine the mdr1 mRNA level. RESULTS: IC(50) of ADM in K562/A02 cells was decreased when treated with Cur or EM, and the reversal times (RvT) was 4.9, 3.7 respectively. The RvT reached to 11.3 when treated with Cur (2.5 microg/ml) combined with EM (120 microg/ml). The DNR MFI in K562/A02 cells was significantly lower than that in K562 cells (P < 0.01), and was increased significantly when treated with Cur (2.5 microg/ml) or EM (120 microg/ml) (P < 0.05). There was no significant difference between DNR MFI of K562/A02 cells treated with Cur (2.5 microg/ml) or EM (120 microg/ml). Immunohistochemistry showed that P-gp expression was significantly higher in K562/A02 cells than in K562 cells (P < 0.01), and was reduced in K562/A02 cells treated with each (P < 0.01), though being still higher than that in K562 cells (P < 0.01). P-gp expression of K562/A02 cells treated with each drug for 5 days were lower than that for 3 days (P < 0.01), and lowered further when treated with Cur and EM together (P < 0.01). Mdr1 mRNA level in K562/A02 cells was higher than in K562 cells (P < 0.01), and was decreased when treated with each of the drugs (P < 0.01). The mdr1 mRNA level of K562/A02 cells treated with Cur (2.5 microg/ml) plus EM (120 microg/ml) was decreased most significantly than that treated with other group of drugs. After 5 day treatment the mdr1 mRNA level of K562/A02 cells with Cur (2.5 microg/ml) was lower than that with EM 120 microg/ml (P < 0.01). CONCLUSIONS: Either Cur or EM can partly reverse the multidrug resistance of K562/A02 cells and decrease the expression and function of P-gp in a time-dependent way. MDR reversing effect of Cur combined with EM is stronger than that of Cur or EM alone.


Assuntos
Curcumina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Eritromicina/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Epirubicina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Células K562 , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
19.
Zhonghua Zhong Liu Za Zhi ; 28(4): 294-7, 2006 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-16875632

RESUMO

OBJECTIVE: To investigate the expression of oncoprotein c-erbB2 in primary breast cancer and to analyze its relation to its prognosis. METHODS: Immunohistochemical staining for c-erbB2 was performed on paraffin-embedded specimens of primary breast cancer from 284 patients, and the relation to its prognosis was statistically analyzed. RESULTS: Positive expression rate of c-erbB2 was 26.8% (76/284) in 284 primary breast cancer patients. Expression of c-erbB2 was positively correlated with the status of lymph node metastasis (P = 0.003). Univariate analysis indicated that c-erbB2 expression is a significant prognostic factor for the disease-free survival (DFS) (P = 0.024) and overall survival (OS) (P = 0.002), while multivariate analysis demonstrated that c-erbB2 is an independent prognostic factor for OS (P = 0.023). Moreover, tumors with c-erbB2 positive expression are more tend to metastasis to other viscera than those with c-erbB2 negative. c-erbB2 expression has different prognostic values for patients with different status of estrogen receptor (ER) and lymph node metastasis. CONCLUSION: c-erbB2 expression is an independent prognostic factor for total survival time in primary breast cancer patients, and its prognostic values are different according to the different ER status and lymph node metastasis.


Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Receptor ErbB-2/metabolismo , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/terapia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Metástase Linfática , Mastectomia Radical , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Radioterapia Adjuvante , Receptores Estrogênicos/metabolismo , Taxa de Sobrevida
20.
Int J Neurosci ; 114(6): 575-91, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15204054

RESUMO

The effect of transient hypertension on blood-brain barrier (BBB) permeability, particularly on extravasation of immunoglobulin G (IgG), has not been fully understood. In the present experiment, we investigated the time course of endogenous albumin and IgG extravasation through BBB and the localization of extravasated IgG in brain parenchyma during adrenaline(AD)-induced transient hypertension in the rat by using Evans blue fluorescence, immunohistochemistry, and Western blot. The results showed that a bolus injection of AD (10 microg/kg) induced a transient elevation of arterial pressure lasting about 1 min. The endogenous albumin and IgG entered the brain parenchyma via BBB only when hypertension occurred. Electron microscopically, the IgG-like immunoreactivities were predominantly seen in the cytoplasm of endothelia of capillaries, pericytes, extracellular space of parenchyma, and the cytoplasm of glial cells. The results suggest that circulating IgG or antibodies might contact the structures of brain parenchyma through passage of BBB when its permeability is temporally changed by transient hypertension. This phenomenon implies a possible mechanism of pathogenesis for immune-mediated diseases in the brain.


Assuntos
Barreira Hematoencefálica/fisiopatologia , Permeabilidade Capilar/fisiologia , Hipertensão/fisiopatologia , Imunoglobulina G/metabolismo , Albuminas/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/ultraestrutura , Western Blotting/métodos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Permeabilidade Capilar/efeitos dos fármacos , Epinefrina , Azul Evans/metabolismo , Hipertensão/induzido quimicamente , Imuno-Histoquímica/métodos , Masculino , Microscopia Imunoeletrônica/métodos , Ratos , Ratos Sprague-Dawley , Análise Espectral/métodos , Fatores de Tempo
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