RESUMO
Kupffer cells (KCs), the largest tissue-resident macrophage population in the body, play a central role in maintaining a delicate balance between immune tolerance and immunity in the liver. However, the underlying molecular mechanism remains elusive. In this study, we show that KCs express high levels of miR-146a, which is under control of the PU.1 transcription factor. miR-146a deficiency promoted KCs differentiation toward a proinflammatory phenotype; conversely, miR-146a overexpression suppressed this phenotypic differentiation. We found that hepatitis B virus (HBV) persistence or HBV surface Ag treatment significantly upregulated miR-146a expression and thereby impaired polarization of KCs toward a proinflammatory phenotype. Furthermore, in an HBV carrier mouse model, KCs depletion by clodronate liposomes dramatically promoted HBV clearance and enhanced an HBV-specific hepatic CD8+ T cell and CD4+ T cell response. Consistent with this finding, miR-146a knockout mice cleared HBV faster and elicited a stronger adaptive antiviral immunity than wild-type mice. In vivo IL-12 blockade promoted HBV persistence and tempered the HBV-specific CTL response in the liver of miR-146a knockout mice. Taken together, our results identified miR-146a as a critical intrinsic regulator of an immunosuppressive phenotype in KCs under inflammatory stimuli, which may be beneficial in maintenance of liver homeostasis under physiological condition. Meanwhile, during HBV infection, miR-146a contributed to viral persistence by inhibiting KCs proinflammatory polarization, highlighting its potential as a therapeutic target in HBV infection.
Assuntos
Hepatite B , Tolerância Imunológica , Células de Kupffer , MicroRNAs , Animais , Hepatite B/imunologia , Vírus da Hepatite B , Células de Kupffer/imunologia , Camundongos , Camundongos Knockout , MicroRNAs/genéticaRESUMO
The placenta and tumors can exhibit a shared expression profile of proto-oncogenes. The basis of placenta-derived heat shock protein gp96, which induces prophylactic and therapeutic T cell responses against cancer including hepatocellular carcinoma (HCC), remains unknown. Here, we identified the associated long peptides from human placental gp96 using matrix-assisted laser desorption/ionization-time-of-flight and mass spectrometry and analyzed the achieved proteins through disease enrichment analysis. We found that placental gp96 binds to numerous peptides derived from 73 proteins that could be enriched in multiple cancer types. Epitope-harboring peptides from glypican 3 (GPC3) and paternally expressed gene 10 (PEG10) were the major antigens mediating anti-HCC T cell immunity. Molecular docking analysis showed that the GPC3- and PEG10-derived peptides, mainly obtained from the cytotrophoblast layer of the mature placenta, bind to the lumenal channel and client-bound domain of the gp96 dimer. Immunization with bone marrow-derived dendritic cells pulsed with recombinant gp96-GPC3 or recombinant gp96-PEG10 peptide complex induced specific T cell responses, and T cell transfusion led to pronounced growth inhibition of HCC tumors in nude mice. We demonstrated that the chaperone gp96 can capture antigenic peptides as an efficient approach for defining tumor rejection oncoantigens in the placenta and provide a basis for developing GPC3 and PEG10 peptide-based vaccines against HCC. This study provides insight into the underlying mechanism of the antitumor response mediated by embryonic antigens from fetal tissues, and this will incite more studies to identify potential tumor rejection antigens from placenta.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Feminino , Humanos , Camundongos , Gravidez , Antígenos de Neoplasias , Proteínas Reguladoras de Apoptose/metabolismo , Carcinoma Hepatocelular/terapia , Proteínas de Ligação a DNA/metabolismo , Glipicanas , Neoplasias Hepáticas/terapia , Camundongos Nus , Simulação de Acoplamento Molecular , Peptídeos , Placenta/metabolismo , Proteínas de Ligação a RNARESUMO
OBJECTIVE: To clarify the relationship between hypoxia stress and the microRNA-155 released from lung cancer cells, to reveal the possible mechanism of brain metastases of lung cancer. METHODS: The hypoxia model of A549 lung cancer cells was established. Lung cancer cells were cultured under the hypoxia condition or normal oxygen condition as control for 0.5, 2, 4, 8, 12 and 24 h immunofluorescence and Western blot methods were used to determine the expression level of heat shock protein 70 (hsp70) in lung cancer cells. Hsp70 overexpressed lung cancer cell line was established, the levels of microRNA-155 in A549 and hsp70 overexpressed A549 cell culture medium were determined by qRT-PCR.An in vitro blood-brain barrier model was established, and was treated with A549 cell culture medium collected at different hypoxia time points. Horseradish peroxidase (HRP) was used to detect the changes of permeability of the in vitro blood-brain barrier model, automatic cell technical instrument was used to count A549 lung cancer cells in the culture medium in under Transwell room. Culture mediums of A549 lung cancer cells collected at different hypoxia time points were injected into rats via tail vein, Western blot was used to analyze the expression of occludin in brain tissue, Evans blue was used to detect the change of blood-brain barrier permeability in animals. RESULTS: When lung cancer cells were hypoxic cultured for 8 h, both the expression level of hsp70 in lung cancer cells and microRNA-155 in culture medium reached the highest level (P < 0.05). Compared with A549 cells, the enhancement of microRNA-155 level in culture medium of hsp70 overexpressed cell was more notably under hypoxia condition. At the same time, the permeability of blood-brain barrier was the highest, and the number of lung cancer cells crossed the blood-brain barrier model was the most. In animal experiment, after injection the lung cancer cell culture fluid with hypoxia 8 h, the tight junction protein occludin expression in blood-brain barrier was lowest, and the permeability of blood-brain barrier was the largest. CONCLUSION: Hypoxia can cause the increase of hsp70 production in lung cancer cells. Increased hsp70 promotes the synthesis and release of microRNA-155, which in turn leads to reduced expression of occludin protein in the blood-brain barrier, resulting in increased permeability of the blood-brain barrier and eventually causing lung cancer cells to metastasize into the brain.
Assuntos
Neoplasias Encefálicas , Neoplasias Pulmonares , MicroRNAs/genética , Células A549 , Animais , Barreira Hematoencefálica , Encéfalo , Humanos , Hipóxia , RatosRESUMO
OBJECTIVE: To study the relationship between hypoxia and the hypoxia inducible factor-1α (HIF-1α) from lung cancer cells, to reveal the possible mechanism of brain metastases of lung cancer. METHODS: The hypoxia model of A549 lung cancer cells was established. After hypoxia culture of A549 cells for 0.5, 2, 4, 8, 12 and 24 h (normal oxygen culture at the same time point was set as the control group), the mass concentration of HIF-1α in A549 lung cancer cell culture medium were determined by ELISA. Transwell chamber was used to construct an in vitro blood brain barrier model, was treated with A549 lung cancer cell culture medium after different time points of hypoxia, Tran endothelial resistance (TER) change of blood-brain barrier model in instrument, to reflect the changes of blood-brain barrier permeability in vitro; A549 lung cancer cells in the culture medium were counted under Transwell room. A549 lung cancer cells with hypoxia at different time points injected into Wistar rats via tail vein, Western blot method was used to menstruate expression of tight junction associated protein Claudin-5 in the brain tissues, Evans blue to detect the change of blood brain barrier permeability in rats. RESULTS: Compared with the control group, the HIF-1α mass concentration in the cell culture solution of A549 increased, the in vitro blood-brain barrier model TER decreased, and the cell number of A549 that passed through transwell into the lower chamber increased (all P<0.05) after hypoxia 2 h, the above effect was most obvious when hypoxia 8 h (all P<0.01). After hypoxia 24 h, it was restored to the control group level. In the in vivo experiment of rats, compared with the control group, the mass percent of Evans blue in rat brain tissues increased after A549 cell culture solution with hypoxia 2 h was injected via caudal vein, meaning increased the permeability of rat blood brain barrier, while the expression of Claudin-5 protein in rat brain tissues decreased (all P<0.05). The effect was most obvious when A549 cell culture solution with hypoxia 8 h was injected into rat tail vein (P<0.01 ). Ejectionof hypoxia 24 h A549 cell culture solution yielded the same effects as those in the control group. CONCLUSION: Hypoxia can induce the increase of HIF-1α in lung cancer cells. The increase of HIF-1α results in the decrease of Claudin-5 expression and increase of blood-brain barrier permeability, leading to lung cancer cells metastasis into the brain.
Assuntos
Neoplasias Encefálicas/secundário , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pulmonares/patologia , Células A549 , Animais , Hipóxia Celular , Humanos , Transplante de Neoplasias , Ratos , Ratos WistarRESUMO
OBJECTIVE: To determine the effect of prostaglandin E2 (PGE2) on brain metastasis of lung cancer,and to explore the possible mechanism of aspirin (PGE2 inhibitor) reducing brain metastasis of lung cancer. METHODS: Radioimmunoassay was performed to measure the expression level of PGE2 in cell supernatant collected from cells treated with or without aspirin (8 mmol/L) at different time points. After establishing in vitro blood-brain barrier (BBB) model using Transwell, lung cancer cells was added to upper chamber of transwell and was then treated with aspirin (8 mmol/L). Western blot was used to examine the expression of occludin protein in brain microvascular endothelial cells. The permeability changes of BBB model in vitro were determined using horseradish peroxides. The number of lung cancer cells passing through BBB model in vitro was counted with Hemocytometer. Effect of aspirin on brain metastasis of lung cancer was observed in nude mice in the animal level. RESULTS: PGE2 level decreased and reached minimum level 120 min after aspirin treatment in lung cancer cells culture fluid. Occludin expression increased and reached maximum level 120 min after aspirin treatment in brain microvascular endothelial cells. At the same time,permeability of BBB and number of lung cancer cells passing through BBB also reached the lowest value 120 min after aspirin treatment. Aspirin significantly reduced the incidence of brain metastasis of lung cancer in animal model. CONCLUSION: Aspirin reduced occurrences of the brain metastasis of lung cancer in animal model,which may be caused by inhibition of PGE2 released by lung cancer cells and upregulation of occludin expression therefore leading to decrease in BBB permeability.
Assuntos
Aspirina/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Metástase Neoplásica , Ocludina/metabolismo , Animais , Encéfalo , Neoplasias Encefálicas/secundário , Dinoprostona/antagonistas & inibidores , Camundongos , Camundongos NusRESUMO
Uterine natural killer (uNK) cells are the most abundant lymphocyte population in the feto-maternal interface during early gestation, and uNK cells play a significant role in the establishment and maintenance of pregnancy-related vascularization, as well as in tolerance to the fetus. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor, fibroblast growth factor-inducible molecule (Fn14), are involved in preventing local cytotoxicity and counterbalancing the cytotoxic function of uNK cells. Here, we studied the regulation of TWEAK/Fn14-mediated innate immunity in the uterus using a lipopolysaccharide (LPS)-induced model of abortion in pregnant mice. Specifically, we detected the expression of TWEAK and Fn14 in the uterus and in uNK cells following LPS treatment. Our results revealed that TWEAK and Fn14 are expressed by uNK cells in pregnant mice; in particular, it appears that the cytokine TWEAK is primarily derived from uNK cells. Interestingly, the down-regulation of TWEAK in uNK cells and the up-regulation of the Fn14 receptor in the uterus in LPS-treated mice may contribute to the disruption of decidual homeostasis by altering uNK cell cytotoxicity - ultimately leading to fetal rejection. In conclusion, the present study strongly suggests that the TWEAK-Fn14 axis in uNK cells is involved in maintaining the tolerance necessary for successful pregnancy.
Assuntos
Aborto Espontâneo/etiologia , Células Matadoras Naturais/imunologia , Fatores de Necrose Tumoral/fisiologia , Útero/imunologia , Aborto Espontâneo/imunologia , Animais , Citocina TWEAK , Modelos Animais de Doenças , Feminino , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Subfamília K de Receptores Semelhantes a Lectina de Células NK/análise , Gravidez , Receptores do Fator de Necrose Tumoral/fisiologia , Receptor de TWEAK , Fator de Necrose Tumoral alfa/análiseRESUMO
OBJECTIVE: To investigate the effect of brucea javanica oil emulsion on the invasiveness of glioma cells and hosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) signaling pathway. METHODS: C6 glioma cells were treated by brucea javanica oil emulsion. The inhibition rate of glioma cells was detected by MTT, Western blot was used to detect protein expression levels of PI3K, AKT, and nuclear factor (NF)-κB in glioma cells. The number of the glioma cells migrated through polycarbonate membrane was detected by crystal violet staining method. RESULTS: Brucea javanica oil emulsion inhibited PI3K, AKT, and NF-κB protein expression which reached the highest inhibition at 30 min, 60 min, and 120 min after brucea javanica oil emulsion, respectively. Maximum suppression on the proliferation of C6 glioma cells reached at 180 min after brucea javanica oil emulsion, while the number of glioma cells migrated through polycarbonate membrane was the least. CONCLUSION: Brucea javanica oil emulsion inhibit the proliferation and invasiveness of glioma cells, which may be related to the inhibition of PI3K/AKT signal pathway.
Assuntos
Brucea/química , Glioma/patologia , Óleos de Plantas/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células , Emulsões , Humanos , NF-kappa B/metabolismo , Invasividade Neoplásica , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de SinaisRESUMO
OBJECTIVE: To investigate the protein expression of the p16 gene and the methylation of its promoter in breast cancer, and to analyze the correlation between the p16 DNA methylation and the clinicopathological features. METHODS: Immuno-histochemistry technique (SP method) and methylation-specific-PCR (MSP) were used to detect p16 protein expression and the methylation of the p16 promoter in 47 breast cancer samples as well as in 20 hyperplasia samples of mammary glands. Results The p16 protein expression in breast cancer samples significantly lower when compared with those of hyperplasia samples (48. 9% vs. 70. 0%) and p16 methylation was more frequent in breast-tumor tissues when compared with those of hyperplasia samples (38. 3% vs. 20. 0%), but the statistical significance wasn't found (P> 0. 05). Down-regulation of p16 protein was negatively correlation with p16 gene hypermethylation (r= -0. 33, P =0. 02). Meanwhile, p16 methylation in breast cancer tissues correlated with histological type, lymph node metastasis, but not correlated with the age, tumor diameter, TNM stage, expression of estrogen receptor (ER) and progesterone receptor (PR) gene status. CONCLUSION: The downregulation of p16 protein induced by promoter methylation of p16 gene may not contribute to early cancinogenesis, but may contribute to progression of breast cancer.
Assuntos
Neoplasias da Mama/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA , Genes p16 , Regiões Promotoras Genéticas , Mama/patologia , Carcinogênese , Progressão da Doença , Regulação para Baixo , Feminino , Humanos , Hiperplasia , Imuno-Histoquímica , Metástase LinfáticaRESUMO
BACKGROUND: The brain is one of the most vulnerable metastasis sites in lung cancer; approximately 40-50% of lung cancer patients develop brain metastasis during the disease course, contributing to the poor prognosis and high mortality of lung cancer patients. Therefore, it is important to clarify the molecular mechanism underlying brain metastasis of lung cancer for improving the overall survival of lung cancer patients. The present study aimed to investigate the potential role of blood-brain barrier (BBB) permeability in the development of brain metastasis of lung cancer and explore the effect of aspirin in an in-vitro BBB model. METHODS: An in-vitro BBB model was established. The expression of heat shock protein 70 (HSP 70), zonula occludens-1 (ZO-1), and occludin in rat brain microvascular endothelial cells was detected using Western blot at different time points following the administration of aspirin. RESULTS: HSP70, ZO-1, and occludin expressions did not show significant changes before aspirin administration, but increased noticeably after aspirin administration. Tumor necrosis factor-α (TNF-α) could significantly attenuate the increased expression of these proteins induced by aspirin. Additionally, TNF-α also significantly reversed the aspirin-induced decrease of BBB permeability. CONCLUSIONS: Aspirin may inhibit brain metastasis of lung cancer in a time-dependent manner via upregulating tight junction proteins to reduce BBB permeability, and this effect can be reversed by TNF-α.
Assuntos
Neoplasias Encefálicas , Neoplasias Pulmonares , Ratos , Animais , Humanos , Proteínas de Junções Íntimas/metabolismo , Ocludina/genética , Ocludina/metabolismo , Ocludina/farmacologia , Células Endoteliais/metabolismo , Regulação para Cima , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Aspirina/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Barreira Hematoencefálica , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Junções Íntimas/metabolismoRESUMO
Thin film nanocomposite (TFN) membranes have proven their unrivaled value, as they can combine the advantages of different materials and furnish membranes with improved selectivity and permeability. The development of TFN membranes has been severely limited by the poor dispersion of the nanoparticles and the weak adhesion between the nanoparticles and the polymer matrix. In this study, to address the poor dispersion of nanoparticles in TFN membranes, we proposed a new combination of m-ZIF-8 and m-HNTs, wherein the ZIF-8 and HNTs were modified with poly (sodium p-styrenesulfonate) to enhance their dispersion in water. Furthermore, the hydropathic properties of the membranes can be well controlled by adjusting the content of m-ZIF-8 and m-HNTs. A series of modified m-ZIF-8/m-HNT/PAN membranes were prepared to modulate the dye/salt separation performance of TFN membranes. The experimental results showed that our m-ZIF-8/m-HNT/PAN membranes can elevate the water flux significantly up to 42.6 L m-2 h-1 MPa-1, together with a high rejection of Reactive Red 49 (more than 80%). In particular, the optimized NFM-7.5 membrane that contained 7.5 mg of HNTs and 2.5 mg of ZIF-8 showed a 97.1% rejection of Reactive Red 49 and 21.3% retention of NaCl.
RESUMO
Preharvest shading significantly influences tea flavor. However, little attention has been given to the mechanism of shading on metabolites, genes, and enzymes in the processing of different tea types. Our study identified 1028 nonvolatile metabolites covering 10 subclasses using a widely targeted metabolome. The results show that shading had a greater effect on the compositions of amino acids, flavonoids, and theaflavins in tea leaves. The combined transcriptomics and enzyme activity analysis results indicate that the upregulated expression of asparagine, aspartate, and tryptophan synthesis genes and proteolytic enzymes promoted the accumulation of amino acids. The downregulated enzyme genes resulted in the reduction of nongalloylated catechins and flavonoid glycosides. Simultaneously, the accumulation of TFs in shaded tea was due to the enhanced enzymatic activities of polyphenol oxidase and peroxidase during processing. Theaflavin-3-3'-di-O-gallate was also significantly positively correlated with the antioxidant and hypoglycemic activities of shaded tea. The results contribute to a better understanding of how preharvest treatments influence summer tea quality.
Assuntos
Camellia sinensis , Catequina , Camellia sinensis/química , Chá/química , Catequina/metabolismo , Flavonoides/metabolismo , Transcriptoma , Aminoácidos/metabolismo , Folhas de Planta/químicaRESUMO
Programmed death ligand 1 (PD-L1) has been recently shown to be a major obstacle to antiviral immunity by binding to its receptor programmed death 1 (PD-1) on specific IFN-γ producing T cells in chronic hepatitis B. Currently, IFN-α is widely used to treat hepatitis B virus (HBV) infection, but its antiviral effect vary greatly and the mechanism is not totally clear. We found that IFN-α/γ induced a marked increase of PD-L1 expression in hepatocytes. Signal and activators of transcription (Stat1) was then identified as a major transcription factor involved in IFN-α/γ-mediated PD-L1 elevation both in vitro and in mice. Blockage of the PD-L1/PD-1 interaction by a specific mAb greatly enhanced HBV-specific T cell activity by the gp96 adjuvanted therapeutic vaccine, and promoted HBV clearance in HBV transgenic mice. Our results demonstrate the IFN-α/γ-Stat1-PD-L1 axis plays an important role in mediating T cell hyporesponsiveness and inactivating liver-infiltrating T cells in the hepatic microenvironment. These data raise further potential interest in enhancing the anti-HBV efficacy of IFN-α and therapeutic vaccines.
Assuntos
Antígeno B7-H1/metabolismo , Vírus da Hepatite B/imunologia , Interferon-alfa/farmacologia , Interferon gama/farmacologia , Fator de Transcrição STAT1/metabolismo , Linfócitos T/imunologia , Regulação para Cima/efeitos dos fármacos , Animais , Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1/química , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Sítios de Ligação , Linhagem Celular , Hepatite B/tratamento farmacológico , Hepatite B/veterinária , Antígenos de Superfície da Hepatite B/sangue , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Receptor de Morte Celular Programada 1/metabolismo , Regiões Promotoras Genéticas , Fator de Transcrição STAT1/química , Linfócitos T/metabolismoRESUMO
This study was performed to determine whether dexamethasone (DEX) had an effect on calcium-activated potassium channels (K(Ca) channels) and Occludin protein in blood-brain tumor barrier (BTB). Using a rat brain glioma model, we found that the expression of K(Ca) channels protein and Occludin protein was significantly increased in brain tumor tissue after DEX treatment for 3 days. Compared with non-DEX-treated animals, Evans Blue levels were greatly attenuated in DEX-treated animals. These effects were significantly reversed by the glucocorticoid receptor antagonist RU38486. In addition, DEX treatment enhanced the density of I(KCa) in the rat brain microvascular endothelial cells (RBMECs) in vitro BTB. All of these results strongly suggest that DEX could be involved in the regulation of both transcellular and paracellular pathway.
Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Edema Encefálico/tratamento farmacológico , Neoplasias Encefálicas/complicações , Artérias Cerebrais/efeitos dos fármacos , Dexametasona/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Barreira Hematoencefálica/fisiologia , Edema Encefálico/etiologia , Edema Encefálico/fisiopatologia , Artérias Cerebrais/metabolismo , Artérias Cerebrais/fisiopatologia , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Azul Evans , Feminino , Indicadores e Reagentes , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/efeitos dos fármacos , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/metabolismo , Proteínas de Membrana/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Mifepristona/farmacologia , Ocludina , Ratos , Ratos Wistar , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismoRESUMO
Bradykinin has been shown to increase the permeability of blood-tumor barrier (BTB) selectively. This study was performed to determine whether tumor necrosis factor-alpha (TNF-alpha) was involved in the regulation of this biological process. We found that the levels of TNF-alpha mRNA and heat shock factor-1 (HSF1) protein in C6 cells were markedly up-regulated by bradykinin via real-time RT-PCR and Western blot methods. And the most obvious increase of HSF1 protein and TNF-alpha mRNA in C6 cells were observed at 5 min and 10 min of bradykinin perfusion, respectively. In addition, the radioactivity of TNF-alpha in C6 cells' culture fluid also mostly increased at 15 min of bradykinin perfusion. And the Evans blue content of brain tumor tissues in rats and the concentration of TNF-alpha reached the maximum at 15 min of bradykinin perfusion. Our results suggested that the bradykinin-mediated BTB permeability increase is due to accelerated release of TNF-alpha, which could cause the increase of BTB permeability by promoting to the release HSF1 from neurospongioma cells.
Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Bradicinina/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Fator de Necrose Tumoral alfa/metabolismo , Animais , Barreira Hematoencefálica/fisiologia , Bradicinina/farmacologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/genética , Linhagem Celular Tumoral , Chaperonina 10/genética , Chaperonina 10/metabolismo , Modelos Animais de Doenças , Masculino , Proteínas da Gravidez/genética , Proteínas da Gravidez/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Fatores Supressores Imunológicos/genética , Fatores Supressores Imunológicos/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/genética , Regulação para Cima/efeitos dos fármacosRESUMO
Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF), and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM). The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.
Assuntos
Ecologia , Meio Ambiente , Densidade Demográfica , Animais , Conservação dos Recursos Naturais , Retroalimentação Fisiológica , Modelos Teóricos , Dinâmica PopulacionalRESUMO
TLR4 in intestinal epithelial cells has been shown both inflammatory and homeostatic roles following binding of its cognate ligand lipopolysaccharide (LPS). TWEAK-Fn14 axis plays an important role in pathologies caused by excessive or abnormal inflammatory responses. This study aimed to evaluate potential cross-talk between TLR4 and TWEAK/Fn14 system in porcine small intestinal epithelial cells. Our in vivo results showed that, compared with the age-matched normal control piglets, increased expression of Fn14 in epithelium and decreased TWEAK expression in lamina propria were detected in the small intestinal of piglets stimulated with LPS. Consistent with this finding, treatment with LPS increased the expression of Fn14 and TLR4 while decreased TWEAK expression in porcine small intestinal epithelial cell lines SIEC02. Interestingly, modulating Fn14 activation using agonistic anti-Fn14 decreased TLR4-mediated TNF-α production by SIEC02. In addition, pretreatment of LPS-stimulated SIEC02 with recombinant TWEAK protein suppresses the expression of Fn14 and TNF-α and inhibits the negative impact of LPS on the tight junctional protein occludin expression. In conclusion, this study demonstrates that the TWEAK-independent Fn14 activation augments TLR4-mediated inflammatory responses in the intestine of piglets. Furthermore, the TWEAK-dependent suppression of Fn14 signaling may play a role in intestinal homeostasis.
Assuntos
Células Epiteliais/imunologia , Infecções por Escherichia coli/veterinária , Escherichia coli/imunologia , Intestinos/imunologia , Lipopolissacarídeos/imunologia , Doenças dos Suínos/imunologia , Receptor de TWEAK/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Apoptose , Citocina TWEAK/imunologia , Células Epiteliais/microbiologia , Escherichia coli/genética , Escherichia coli/fisiologia , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Feminino , Intestinos/microbiologia , Masculino , Transdução de Sinais , Suínos , Doenças dos Suínos/genética , Doenças dos Suínos/microbiologia , Receptor de TWEAK/genética , Receptor 4 Toll-Like/genéticaRESUMO
Metal-organic frameworks (MOFs) are studied for the design of advanced nanocomposite membranes, primarily due to their ultrahigh surface area, regular and highly tunable pore structures, and favorable polymer affinity. However, the development of engineered MOF-based membranes for water treatment lags behind. Here, thin-film nanocomposite (TFN) membranes containing poly(sodium 4-styrenesulfonate) (PSS) modified ZIF-8 (mZIF) in a polyamide (PA) layer were constructed via a facile interfacial polymerization (IP) method. The modified hydrophilic mZIF nanoparticles were evenly dispersed into an aqueous solution comprising piperazine (PIP) monomers, followed by polymerizing with trimesoyl chloride (TMC) to form a composite PA film. FT-IR spectroscopy and XPS analyses confirm the presence of mZIF nanoparticles on the top layer of the membranes. SEM and AFM images evince a retiform morphology of the TFN-mZIF membrane surface, which is intimately linked to the hydrophilicity and adsorption capacity of mZIF nanoparticles. Furthermore, the effect of different ZIF-8 loadings on the overall membrane performance was studied. Introducing the hydrophilizing mZIF nanoparticles not only furnishes the PA layer with a better surface hydrophilicity and more negative charge but also more than doubles the original water permeability, while maintaining a high retention of Na2SO4. The ultrahigh retentions of reactive dyes (e.g., reactive black 5 and reactive blue 2, >99.0%) for mZIF-functionalized PA membranes ensure their superior nanofiltration performance. This facile, cost-effective strategy will provide a useful guideline to integrate with other modified hydrophilic MOFs to design nanofiltration for water treatment.
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The aim of the present study was to investigate the expression of caveolin-1 in rat brain glioma tissue, and to determine whether interleukin-1ß (IL-1ß) has a role in this process. Using glioma cells, a tumor-burdened rat model was established, and the expression of caveolin-1 protein in the tumor sites was significantly increased following intracarotid infusion of IL-1ß (3.7 ng/kg/min), as indicated by western blot analysis. The maximum value of the caveolin-1 expression was observed in tumor-burdened rats after 60 min of IL-1ß perfusion, and which was significantly enhanced by vascular endothelial growth factor (VEGF). In addition, VEGF also significantly increased IL-1ß-induced blood tumor barrier (BTB) permeability. The results suggest that the IL-1ß-induced BTB permeability increase may be associated with the expression of caveolin-1 protein, and VEGF may be involved in this process.
RESUMO
The present study was performed to determine whether aspirin, a cyclooxygenase (COX) inhibitor, has an effect on the expression of connexin 43 (Cx43) in C6 glioma cells. Using an in vitro glioma invasion model, the expression of Cx43 protein in C6 cells was significantly increased following aspirin treatment at a dose of 8 mmol/l for 30, 60 and 120 min via western blot analysis. The peak value of the Cx43 expression was observed in C6 cells after 120 min of aspirin treatment, which was significantly reduced by prostaglandin E2 (PGE2). In addition, aspirin also significantly increased the gap junction intercellular communication (GJIC) activity and reduced glioma invasion, which was induced by PGE2. This led to the conclusion that the aspirin-induced glioma invasion decrease may be associated with the increased expression of Cx43 protein and formation of GJIC.
RESUMO
Organized arrays of halloysite clay nanotubes have great potential in molecular separation, absorption, and biomedical applications. A highly oriented layer of halloysite on polyacrylonitrile porous membrane was prepared via a facile evaporation-induced method. Scanning electronic microscopy, surface attenuated total reflection Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy mapping indicated formation of the nanoarchitecture-controlled membrane. The well-ordered nanotube coating allowed for the excellent dye rejection (97.7% for reactive black 5) with high salt permeation (86.5% for aqueous NaCl), and thus these membranes were suitable for dye purification or concentration. These well-aligned nanotubes' composite membranes also showed very good fouling resistance against dye accumulation and bovine serum albumin adsorption as compared to the pristine polyacrylonitrile or membrane coated with disordered halloysite layer.