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1.
PLoS One ; 19(4): e0299846, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38669264

RESUMO

The decoupling of control and forwarding layers brings Software-Defined Networking (SDN) the network programmability and global control capability, but it also poses SDN security risks. The adversaries can use the forwarding and control decoupling character of SDN to forge legitimate traffic, launching saturation attacks targeted at SDN switches. These attacks can cause the overflow of switch flow tables, thus making the switch cannot forward benign network traffic. How to effectively detect saturation attack is a research hotspot. There are only a few graph-based saturation attack detection methods. Meanwhile, the current graph generation methods may take useless or misleading information to the attack detection, thus decreasing the attack detection accuracy. To solve the above problems, this paper proposes TITAN, a bidirecTional forwardIng graph-based saturaTion Attack detectioN method. TITAN defines flow forwarding rules and topology information, and designs flow statistical features. Based on these definitions, TITAN generates nodes of the bi-forwarding graph based on the flow statistics features and edges of the bi-forwarding graph based on the network traffic routing paths. In this way, each traffic flow in the network is transformed into a bi-directional forwarding graph. Then TITAN feeds the above bidirectional forwarding graph into a Graph Convolutional Network (GCN) to detect whether the flow is a saturation attack flow. The experimental results show that TITAN can effectively detect saturation attacks in SDNs with a detection accuracy of more than 97%.


Assuntos
Algoritmos , Segurança Computacional , Software , Redes de Comunicação de Computadores
2.
Anim Reprod Sci ; 251: 107224, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37003063

RESUMO

Optimized reproduction management enhances fertility of dairy cows, and thus improves their milk production efficiency. Comparing different synchronization protocols under variable ambient conditions would be conducive to protocol selection and production efficiency improvement. Here, 9538 primiparous Holstein lactating cows were enrolled to either Double-Ovsynch (DO) or Presynch-Ovsynch (PO) to determine the outcomes under different ambiences. We found that averaged THI of 21-days before the first service (THI-b) was the best indicators in a total of 12 environmental indexes to explain changes in conception rate. And the conception rate decreased linearly in DO treated cows when THI-b was over 73, whereas the threshold was 64 in cows subjected to PO. Compared with PO treated cows, DO increased conception rate by 6%, 13% and 19%, when THI-b was lower than 64, from 64 to 73, and over 73, respectively. Furthermore, employing treatment of PO would lead greater risk for cows staying open compared with DO when THI-b below 64 (hazard ratio, 1.3) and over 73 (hazard ratio, 1.4). Most importantly, calving intervals were 15 days shorter in DO treated cows compared PO when THI-b over 73, while no difference was detected when THI-b below 64. In conclusion, our results supported that, fertility of primiparous Holstein cows could be improved by employing DO, especially in hot weather (THI-b ≥ 73), and the benefits of DO protocol were abated under cool conditions (THI-b < 64). Considering the impacts of environmental heat load is necessary to determine reproductive protocols for commercial dairy farm.


Assuntos
Sincronização do Estro , Lactação , Feminino , Bovinos , Animais , Sincronização do Estro/métodos , Temperatura Alta , Inseminação Artificial/veterinária , Inseminação Artificial/métodos , Reprodução , Dinoprosta , Hormônio Liberador de Gonadotropina , Progesterona
3.
Front Pharmacol ; 14: 1136772, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36873997

RESUMO

Ramulus Mori (Sangzhi) alkaloids (SZ-A) derived from twigs of mulberry (Morus alba L., genus Morus in the Moraceae family) was approved by the National Medical Products Administration in 2020 for the treatment of type 2 diabetes mellitus. In addition to excellent hypoglycemic effect, increasing evidence has confirmed that SZ-A exerts multiple pharmacological effects, such as protecting pancreatic ß-cell function, stimulating adiponectin expression, and alleviating hepatic steatosis. Importantly, a specific distribution of SZ-A in target tissues following oral absorption into the blood is essential for the induction of multiple pharmacological effects. However, there is a lack of studies thoroughly exploring the pharmacokinetic profiles and tissue distribution of SZ-A following oral absorption into the blood, particularly dose-linear pharmacokinetics and target tissue distribution associated with glycolipid metabolic diseases. In the present study, we systematically investigated the pharmacokinetics and tissue distribution of SZ-A and its metabolites in human and rat liver microsomes, and rat plasma, as well as its effects on the activity of hepatic cytochrome P450 enzymes (CYP450s). The results revealed that SZ-A was rapidly absorbed into the blood, exhibited linear pharmacokinetic characteristics in the dose range of 25-200 mg/kg, and was broadly distributed in glycolipid metabolism-related tissues. The highest SZ-A concentrations were observed in the kidney, liver, and aortic vessels, followed by the brown and subcutaneous adipose tissues, and the heart, spleen, lung, muscle, pancreas, and brain. Except for the trace oxidation products produced by fagomine, other phase I or phase II metabolites were not detected. SZ-A had no inhibitory or activating effects on major CYP450s. Conclusively, SZ-A is rapidly and widely distributed in target tissues, with good metabolic stability and a low risk of triggering drug-drug interactions. This study provides a framework for deciphering the material basis of the multiple pharmacological functions of SZ-A, its rational clinical use, and the expansion of its indications.

4.
J Extracell Vesicles ; 11(9): e12264, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36068649

RESUMO

Pattern-recognition receptors (PRRs) have been shown to promote tumour metastasis via sensing tumour cell-derived small extracellular vesicles (EVs). Nucleotide-binding oligomerisation domain 1 (NOD1), a cytoplasmic PRR, plays a role in colorectal cancer (CRC) by detecting bacterial products. However, the precise mechanisms underlying the effects of NOD1, following identification of CRC cell-derived EVs (CRC-EVs), to potentiate CRC liver metastasis (CRC-LM), remain poorly understood. Here, we demonstrate that CRC-EVs activate NOD1 in macrophages to initiate secretion of inflammatory cytokines and chemokines. NOD1-activated macrophages also promote CRC cell migration, while in a murine model of liver metastasis (LM), NOD1-deficient mice exhibit reduced metastasis following CRC-EV treatment. Furthermore, cell division cycle 42 (CDC42), a small Rho guanosine-5'-triphosphate (GTP)ase, is delivered by CRC-EVs into macrophages where it activates NOD1. In addition, EVs from the plasma of patients with CRC-LM mediate NOD1 activation in human peripheral blood mononuclear cells. Moreover, high NOD1 expression in tumour tissues is associated with poor prognosis of CRC-LM. Our findings suggest that CRC-EVs activate NOD1 to promote tumour metastasis, thus, NOD1 may serve as a potential target in the diagnosis and treatment of CRC-LM.


Assuntos
Neoplasias Colorretais , Vesículas Extracelulares , Neoplasias Hepáticas , Animais , Vesículas Extracelulares/metabolismo , Humanos , Leucócitos Mononucleares/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos , Proteína Adaptadora de Sinalização NOD1/metabolismo , Transdução de Sinais
5.
Arch Microbiol ; 204(7): 427, 2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35751751

RESUMO

A novel aerobic, Gram-staining-negative, non-motile, short-rod-shaped strain, designated f23T, was obtained from Daihai Lake, Inner Mongolia, Republic of China. 16S rRNA gene sequences analysis showed that f23T belongs to the genus Orrella and is most closely related to Orrella marina H-Z20T with 98.35% sequence similarity. The strain was oxidase positive, catalase positive and had well growth at pH 6.5-8.5, at temperature 28-40 °C and at 0-4.5% (w/v) NaCl. Colonies incubated at 37 °C on marine 2216 agar for 3 days were white, smooth, transparent, circular and less than 1.0 mm in diameter. The total genome size of f23T was 2,803,849 bp with a G + C content of 52.79%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain f23T and O. marina H-Z20T were 69.62% and 20.5%, which both below the species delineation threshold. Chemotaxonomic analysis showed that C16:0, cyclo-C17:0, C18:0, Sum Feature 3 (C16:1ω7c and/or C16:1ω6c) and Sum Feature 8 (C18:1ω6c and C18:1ω7c) as the major fatty acids, ubiquinone-8 as the major isoprenoid quinone, phosphatidylethanolamine as the major cellular polar lipids. Based on the polyphasic analysis, f23T represents a novel species within the genus Orrella, for which the name Orrella daihaiensis sp. nov. is proposed. The type strain is f23T (= CGMCC 1.18761 T = KCTC 82425 T).


Assuntos
Alcaligenaceae , Lagos , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Lagos/microbiologia , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Animals (Basel) ; 12(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35268133

RESUMO

We aimed to research the neutrophil extracellular traps (NETs) and reactive oxygen species (ROS) formation capacity of polymorphonuclear cells (PMN) during different lactational stages of Holstein cows. We also aimed to validate a model which could mimic infection and inflammation in vitro by adding increasing concentrations of lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) to PMN suspensions isolated from nulliparous heifers and evaluate their capacity to produce NETs and ROS. In 3 replicates, we collected blood from nulliparous heifers (n = 3), cows at the end of gestation (n = 3), early postpartum (n = 3) and in mid-lactation (n = 3) in which PMN were isolated. The production of ROS in PMN were assessed using the 2',7'-Dichlorofluorescein diacetate method, while the SYTOX Orange and Quant-iT™ PicoGreen dsDNA ultra-sensitive nucleic fluorescent acid staining methods were applied in order to quantitatively analyze the formation of NETs. Statistical analyses were performed via linear regression models using the replicate as a random. ROS values of PMN harvested from peripartum cows were 1.3 times increased compared with those in nulliparous heifers (p < 0.01). Compared with nulliparous heifers, the production of NETs by PMN isolated from mid-lactation and postpartum cows was 2.1 and 2.5 times higher (p < 0.01), respectively. In 3 replicates, in vitro stimulation of PMN isolated from nulliparous heifers (n = 3) with LPS linearly increased the production of ROS and NETs (R2 = 0.96 and 0.86, respectively). Similarly, when PMN isolated from nulliparous heifers were stimulated with PMA, a linear increase in the production of ROS (R2 = 0.99) and NETs (R2 = 0.78) was observed. The basal NETs and ROS production is lower in nulliparous heifers. Thus, they are an excellent model to mimic inflammation and study fundamental aspects of the production of NETs and ROS in vitro.

8.
Front Vet Sci ; 7: 604729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33585595

RESUMO

Understanding the postpartum uterine involution pattern and embryonic development could facilitate bovine reproduction management, improve reproductive efficiency, and diagnosis of the reproductive disorder, which would contribute to the success of the dairy business. This study aimed to investigate postpartum uterine involution and embryonic developmental patterns or postconceptional marks of embryonic fetal development in Chinese Holstein dairy cows using B-mode ultrasonography. The results revealed a significant decline in the involution period with an increase of parity and age. The uterine involution period was shorter in multiparous cows when compared with cows with lower parities. Consistently, cows over 4 years old recovered faster than younger cows (2 or 3 years). Besides, the elder cows (over 4 years) had a relatively larger size of resumed cervix uteri and horns. Postpartum uterine involution pattern analysis revealed that the reproductive tract recovered very fast during the first 16 days postpartum for all the parity. Results of postconceptional marks of embryo development revealed a slow increase in diameter of the gravid uterine horn and crown-rump length (CRL) before day 60. In contrast, this increase was dramatic and rapid after the 60th day. We also established two models to estimate gestational age based on gravid uterine horn diameter or CRL. A formula was established to determine the gravid uterine horn size during postconceptional on day 30th-day 90th (r = 0.8714, P < 0.01). In addition, a significant positive correlation between CRL and gestational age (r = 0.98151, P < 0.01) was built. In conclusion, these results illustrated that parity and calving age had significant effects on uterine involution in Chinese Holstein cows. Crown-rump length and gravid uterine horn diameter are both efficient for evaluating the embryo growth. These current findings broaden the understanding of basic reproductive pattern in Chinese Holstein cows and could benefit bovine reproductive management primarily in postpartum and early pregnant cows to reduce the calving interval and avoid periparturient metabolic diseases.

9.
Sci Adv ; 5(7): eaaw6710, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31328168

RESUMO

Genome-wide association studies identified single-nucleotide polymorphism (SNP) rs55958994 as a significant variant associated with increased susceptibility to prostate cancer. However, the mechanisms by which this SNP mediates increased risk to cancer are still unknown. In this study, we show that this variant is located in an enhancer active in prostate cancer cells. Deletion of this enhancer from prostate tumor cells resulted in decreased tumor initiation, tumor growth, and invasive migration, as well as a loss of stem-like cells. Using a combination of capture chromosome conformation capture (Capture-C) and RNA sequencing, we identified genes on the same and different chromosomes as targets regulated by the enhancer. Furthermore, we show that expression of individual candidate target genes in an enhancer-deleted cell line rescued different aspects of tumorigenesis. Our data suggest that the rs55958994-associated enhancer affects prostate cancer progression by influencing expression of multiple genes via long-range chromatin interactions.


Assuntos
Cromatina/metabolismo , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Alelos , Sequência de Bases , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos , Humanos , Masculino , Fenótipo , Fatores de Risco , Deleção de Sequência/genética , Transcriptoma/genética
10.
Cell Stem Cell ; 13(1): 36-47, 2013 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-23747203

RESUMO

Epigenetic mechanisms underlying somatic reprogramming have been extensively studied, but little is known about the nuclear architecture of pluripotent stem cells (PSCs). Using circular chromosome conformation capture with high-throughput sequencing (4C-seq) and fluorescence in situ hybridization (FISH), we identified chromosomal regions that colocalize frequently with the Oct4 locus in PSCs. These PSC-specific long-range interactions are established prior to transcriptional activation of endogenous Oct4 during reprogramming to induced PSCs and are facilitated by Klf4-mediated recruitment of cohesin. Depletion of Klf4 leads to unloading of cohesin at the Oct4 enhancer and disrupts long-range interactions prior to loss of Oct4 transcription and subsequent PSC differentiation, suggesting a causative role for Klf4 in facilitating long-range interactions independent of its transcriptional activity. Taken together, our results delineate the basic nuclear organization at the Oct4 locus in PSCs and suggest a functional role for Klf4-mediated higher-order chromatin structure in maintaining and inducing pluripotency.


Assuntos
Reprogramação Celular/genética , Cromatina/genética , Cromossomos/genética , Células-Tronco Embrionárias/citologia , Fatores de Transcrição Kruppel-Like/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/citologia , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Imunoprecipitação da Cromatina , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/metabolismo , Elementos Facilitadores Genéticos , Epigênese Genética , Fibroblastos/citologia , Fibroblastos/metabolismo , Citometria de Fluxo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Hibridização in Situ Fluorescente , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Fator 3 de Transcrição de Octâmero/genética , Células-Tronco Pluripotentes/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Hepatology ; 57(1): 171-82, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22859216

RESUMO

UNLABELLED: Hepatocellular carcinoma (HCC) is a complication at the endstage of chronic inflammatory liver diseases with dismal prognosis. Targeting of Toll-like receptor (TLR) 2 attenuates tumor metastases; we hypothesized that blocking TLR2 might also play a crucial role in reducing hepatocarcinogenesis. Surprisingly, we found that the genetic deletion of TLR2 increased susceptibility to diethylnitrosamine (DEN), a genotoxic carcinogen that can induce HCC. Indeed, TLR2-deficient mice showed a significant increase in carcinogenesis and progression of HCC as indicated by increases in tumor nodule size, tumor volume, and animal death. The enhanced susceptibility to DEN-induced HCC was associated with a broad-spectrum reduction in the immune response to DEN-induced liver injury. We found that TLR2 deficiency caused a decrease in the infiltration of macrophages and an attenuation of apoptosis signal regulating kinase 1 (ASK1) / p38 mitogen-activated protein kinase (p38 MAPK) / nuclear factor kappa B (NF-κB) signaling, which led to a decrease in the expression of interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-1α/ß, IL-6, and Cxcl-2 as well as suppression of autophagy flux and increases in oxidative stress and p62 aggregation in liver tissue. The defects in immune networks resulted in suppressed p21- and p16/pRb-dependent senescence, which caused an increase in proliferation and a decrease in apoptotic and autophagy-associated cell death in mouse livers. Restoring cellular senescence and autophagy flux by treating TLR2-deficient mice with IFN-γ, a T helper 1 (Th1) cytokine and positive modulator of senescence and autophagy, could attenuate the carcinogenesis and progression of HCC associated with TLR2-deficient animals. CONCLUSION: The loss of immune networks supporting cellular senescence and autophagy flux is attributed to enhanced susceptibility to DEN-induced hepatocellular carcinogenesis and progression in TLR2-deficient mice. These findings may be used to prevent the development of liver cancer.


Assuntos
Carcinoma Hepatocelular/imunologia , Transformação Celular Neoplásica , Senescência Celular , Neoplasias Hepáticas/imunologia , Receptor 2 Toll-Like/metabolismo , Alquilantes , Animais , Autofagia , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Dietilnitrosamina , Progressão da Doença , Feminino , Interferon gama/metabolismo , Fígado/imunologia , Fígado/metabolismo , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição TFIIH , Fatores de Transcrição/metabolismo
12.
Vet Immunol Immunopathol ; 147(3-4): 195-201, 2012 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-22572235

RESUMO

Toll-like receptors (TLRs) are a class of pattern recognition receptors that play a pivotal role in the innate and adaptive immune systems. Studies have shown that TLR variants play roles in various human infectious diseases. The aim of the present study was to investigate whether the functional genetic variations at positions C632T, G1409A, A1475C, G1550A and G1596A in TLR1 and at A2700G and A3156G in TLR9 confer susceptibility or resistance to bovine tuberculosis (bTB). Genotyping of the TLR1 and TLR9 gene polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and single-strand conformation polymorphism (PCR-SSCP) in 586 Chinese Holstein cows (154 infected with bTB, 432 non-infected). The frequencies of the GH and HH genotypes at TLR1-G1596A differed significantly between bTB-infected and non-infected animals [p=0.001 for both GH and HH; GH odds ratio (OR)=2.43 95% confidence interval (CI) (1.47-4.03); and HH OR=1.49 95% CI (0.85-2.62)]. There was a trend toward an increased relative risk of tuberculosis (TB) incidence in the CD genotype at the TLR1-A1475C locus [p=0.056, OR=1.59 95% CI (0.98-2.58)]. The present study suggests that variants in the TLR1 gene are associated with susceptibility to bTB, whereas no significant association can be inferred from the polymorphisms in the TLR9 gene.


Assuntos
Polimorfismo de Nucleotídeo Único , Receptor 1 Toll-Like/genética , Receptor Toll-Like 9/genética , Tuberculose Bovina/genética , Tuberculose Bovina/imunologia , Animais , Sequência de Bases , Bovinos , China , Primers do DNA/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Fatores de Risco
13.
Am J Pathol ; 180(1): 275-92, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22062220

RESUMO

Pulmonary fibrosis is an inflammation-driven lung disease with a poor prognosis and no cure. Here we report that basal toll-like receptor 4 (TLR4) activity is critical for the resolution of acute and chronic inflammation and pulmonary fibrosis in mouse models of lung injury. We found that genetic or pharmacologic inhibition of TLR4 exacerbates bleomycin-induced pulmonary inflammation, fibrosis, dysfunction, and animal death through promoting formation of an immunosuppressive tissue microenvironment and attenuating autophagy-associated degradation of collagen and cell death in the fibrotic lung tissues. In contrast, pharmacologic activation of TLR4 resulted in a quick resolution of acute inflammation, reversed the established pulmonary fibrosis, improved lung function, and rescued mice from death. Similarly, blocking TLR4 impaired the resolution of silica-induced chronic inflammation and fibrosis. Importantly, altering autophagic activity could reverse the TLR4-regulated lung inflammation, fibrosis, dysfunction, and animal death. Rapamycin, an autophagy activator, reversed the effects of TLR4 antagonism. In contrast, inhibition of autophagy by 3-methyladenine reversed the proresolving and antifibrotic roles of TLR4 agonists and increased animal death. These results not only highlight a pivotal role for TLR4-mediated basal immunity, particularly autophagic activity, in the proresolution of inflammation and fibrosis after chemical-induced lung injury but also provide proof for the concept for activating TLR4 signaling, particularly TLR4-mediated autophagy, as a novel therapeutic strategy against chronic fibroproliferative diseases that are unresponsive to current therapy.


Assuntos
Lesão Pulmonar Aguda/fisiopatologia , Fibrose Pulmonar Idiopática/fisiopatologia , Lesão Pulmonar/fisiopatologia , Pneumonia/fisiopatologia , Receptor 4 Toll-Like/fisiologia , Lesão Pulmonar Aguda/patologia , Animais , Apoptose/fisiologia , Autofagia/fisiologia , Fibrose Pulmonar Idiopática/patologia , Lesão Pulmonar/patologia , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Pneumonia/patologia , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/deficiência
14.
PLoS One ; 6(9): e24705, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21931823

RESUMO

BACKGROUND: Immunotherapy is often recommended as an adjuvant treatment to reduce the chance of cancer recurrence or metastasis. Interestingly, timing is very important for a successful immunotherapy against metastasis, although the precise mechanism is still unknown. METHODS AND FINDINGS: Using a mouse model of melanoma metastasis induced by intravenous injection of B16-F10 cells, we investigated the mechanism responsible for the diverse efficacy of the prophylactic or therapeutic TLR4 and TLR9 agonist complex against metastasis. We found that the activation of TLR4 and TLR9 prevented, but did not reverse, metastasis because the potency of this combination was neither sufficient to overcome the tumor cell-educated immune tolerance nor to induce efficacious autophagy in tumor cells. The prophylactic application of the complex promoted antimetastatic immunity, leading to the autophagy-associated death of melanoma cells via IFNγ/STAT1 activation and attenuated tumor metastasis. IFNγ neutralization reversed the prophylactic benefit induced by the complex by suppressing STAT1 activation and attenuating autophagy in mice. However, the therapeutic application of the complex did not suppress metastasis because the complex could not reverse tumor cell-induced STAT3 activation and neither activate IFNγ/STAT1 signaling and autophagy. Suppressing STAT3 activation with the JAK/STAT antagonist AG490 restored the antimetastatic effect of the TLR4/9 agonist complex. Activation of autophagy after tumor inoculation by using rapamycin, with or without the TLR4/9 agonist complex, could suppress metastasis. CONCLUSION AND SIGNIFICANCE: Our studies suggest that activation of IFNγ/STAT1 signaling and induction of autophagy are critical for an efficacious anti-metastatic immunotherapy and that autophagy activators may overcome the timing barrier for immunotherapy against metastasis.


Assuntos
Imunoterapia/métodos , Interferon gama/metabolismo , Fator de Transcrição STAT1/metabolismo , Animais , Apoptose/fisiologia , Autofagia/fisiologia , Western Blotting , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Interferon gama/genética , Pulmão/metabolismo , Pulmão/patologia , Pulmão/ultraestrutura , Melanoma/complicações , Melanoma/terapia , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Metástase Neoplásica/prevenção & controle , Metástase Neoplásica/terapia , Fator de Transcrição STAT1/genética , Fatores de Tempo
15.
J Cell Sci ; 124(Pt 19): 3235-46, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21896644

RESUMO

Tribbles homolog 3 (TRB3, also known as TRIB3, NIPK and SKIP3), a human homolog of Drosophila Tribbles, has been found to interact with a variety of signaling molecules to regulate diverse cellular functions. Here, we report that TRB3 is a novel SMAD3-interacting protein. Expression of exogenous TRB3 enhanced the transcriptional activity of SMAD3, whereas knocking down endogenous TRB3 reduced the transcriptional activity of SMAD3. The kinase-like domain (KD) of TRB3 was responsible for the interaction with SMAD3 and the regulation of SMAD3-mediated transcriptional activity. In addition, TGF-ß1 stimulation or overexpression of SMAD3 enhanced the TRB3 promoter activity and expression, suggesting that there is a positive feedback loop between TRB3 and TGF-ß-SMAD3 signaling. Mechanistically, TRB3 was found to trigger the degradation of SMAD ubiquitin regulatory factor 2 (Smurf2), which resulted in a decrease in the degradation of SMAD2 and phosphorylated SMAD3. Moreover, TRB3-SMAD3 interaction promoted the nuclear localization of SMAD3 because of the interaction of TRB3 with the MH2 domain of SMAD3. These effects of TRB3 were responsible for potentiating the SMAD3-mediated activity. Furthermore, knockdown of endogenous TRB3 expression inhibited the migration and invasion of tumor cells in vitro, which were associated with an increase in the expression of E-cadherin and a decrease in the expression of Twist-1 and Snail, two master regulators of epithelial-to-mesenchymal transition, suggesting a crucial role for TRB3 in maintaining the mesenchymal status of tumor cells. These results demonstrate that TRB3 acts as a novel SMAD3-interacting protein to participate in the positive regulation of TGF-ß-SMAD-mediated cellular biological functions.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Movimento Celular , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Repressoras/metabolismo , Proteína Smad3/metabolismo , Actinas/metabolismo , Caderinas/metabolismo , Proteínas de Ciclo Celular/genética , Núcleo Celular/metabolismo , Transição Epitelial-Mesenquimal , Técnicas de Silenciamento de Genes , Genes Reporter , Células Hep G2 , Humanos , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Invasividade Neoplásica , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/genética , Transporte Proteico , Proteólise , Interferência de RNA , Proteínas Repressoras/genética , Ativação Transcricional , Ubiquitina-Proteína Ligases/metabolismo
16.
J Immunol ; 187(6): 3003-14, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21841134

RESUMO

Pulmonary fibrosis is the pathologic basis for a variety of incurable human chronic lung diseases. IL-17A, a glycoprotein secreted from IL-17-producing cells, has recently been shown to be a proinflammatory cytokine involved in chronic inflammation and autoimmune disease. In this study, we report that IL-17A increased the synthesis and secretion of collagen and promoted the epithelial-mesenchymal transition in alveolar epithelial cells in a TGF-ß1-dependent manner. Using in vivo fibrotic models, we found IL-17A expression to be elevated and IL-17A-associated signaling pathways to be activated in fibrotic lung tissues. Neutralization of IL-17A in vivo promoted the resolution of bleomycin-induced acute inflammation, attenuated pulmonary fibrosis, and increased survival. Additionally, IL-17A antagonism inhibited silica-induced chronic inflammation and pulmonary fibrosis. Targeting IL-17A resulted in a shift of the suppressive immune response in fibrotic lung tissue toward a Th1-type immune response, and it effectively induced autophagy, which promoted the autophagic degradation of collagen and autophagy-associated cell death. Moreover, IL-17A was found to attenuate the starvation-induced autophagy, and autophagy modulators regulated collagen degradation in the alveolar epithelial cells in a TGF-ß1-independent manner. Administration of 3-methylamphetamine, an autophagy inhibitor, reversed the therapeutic efficacy of IL-17A antagonism in pulmonary fibrosis. Our studies indicate that IL-17A participates in the development and progression of pulmonary fibrosis in both TGF-ß1-dependent and -independent manners and that the components of the IL-17A signaling pathway are potential therapeutic targets for the treatment of fibroproliferative lung diseases.


Assuntos
Interleucina-17/metabolismo , Pneumonia/metabolismo , Fibrose Pulmonar/metabolismo , Transdução de Sinais/imunologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Autofagia , Western Blotting , Líquido da Lavagem Broncoalveolar/química , Separação Celular , Colágeno/biossíntese , Transição Epitelial-Mesenquimal/imunologia , Citometria de Fluxo , Interleucina-17/antagonistas & inibidores , Interleucina-17/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Pneumonia/imunologia , Pneumonia/patologia , Fibrose Pulmonar/imunologia , Fibrose Pulmonar/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta1/imunologia
17.
Acta Pharmacol Sin ; 32(8): 1045-54, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21706041

RESUMO

AIM: To explore the pathogenic role of Th17 cells and interleukin-17A (IL-17A)-associated signaling pathways in spontaneous pulmonary emphysema induced by a Toll-like receptor 4 mutant (TLR4(mut)). METHODS: Lungs were obtained from wild-type (WT) or TLR4mut mice that were treated with or without recombinant mouse IL-17A (1 µg·kg(-1)·d(-1), ip) from the age of 3 weeks to 3 months. Pulmonary emphysema was determined using histology, immunochemistry, and biochemical analysis. T cell polarization was determined with flow cytometry, the levels of cytokines were measured using ELISA, and the levels of IL-17A-associated signaling molecules were detected using Western blot. RESULTS: Compared to WT mice, 3 month-old TLR4(mut) mice were characterized by significantly reduced infiltration of Th17 cells into lungs (2.49%±1.13 % νs 5.26%±1.39%), and significantly reduced expression levels of IL-17A (3.66±0.99 pg/µg νs 10.67±1.65 pg/µg), IL-23 (12.43±1.28 pg/µg νs 28.71±2.57 pg/µg) and IL-6 (51.82±5.45 pg/µg νs 92.73±10.91 pg/µg) in bronchoalveolar lavage fluid. In addition, p38 MAPK phosphorylation and AP-1 expression were decreased to 27%±9% and 51%±8%, respectively, of that in WT mice. Treatment of TLR4(mut) mice with IL-17A increased the infiltration of Th17 cells into lungs and expression levels of IL-17A, IL-6, and IL-23 in bronchoalveolar lavage fluid, attenuated MDA and apoptosis, and improved emphysema accompanied with increased phosphorylation of p38 MAPK and expression of AP-1. CONCLUSION: Th17 cells, in particular the cytokine IL-17A, play a crucial role in the pathogenesis of TLR4(mut)-induced spontaneous pulmonary emphysema. Both of them are potential targets for therapeutic strategies for pulmonary emphysema.


Assuntos
Interleucina-17/metabolismo , Enfisema Pulmonar/genética , Enfisema Pulmonar/metabolismo , Células Th17/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C3H , Mutação/genética
18.
Acta Pharmacol Sin ; 31(12): 1583-92, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21113175

RESUMO

AIM: to study whether activation of TLR9 by CpG-ODN would protect against and/or reverse renal fibrosis. METHODS: animals were treated with CpG-ODN before or after undergoing a unilateral ureteral obstruction (UUO) procedure. The interstitial fibrotic lesions of obstructed kidneys were evaluated using histology and immunohistostaining. The Th2-type cytokine profile and the expression and activity of sma and mad related protein (Smad)3, signal transducers and activators of transcription (Stat)3, extracellular regulated protein kinases (ERK), and p38 kinase were determined using RT-PCR or Western blot. RESULTS: the obstructed kidneys displayed a significant increase in interstitial fibrosis, an infiltration of macrophages in the interstitium, and an enhanced expression of Th2 cytokines. Prophylactic application of CpG-ODN (40 microg/kg every 3 days from 2 h before UUO until the 14th day after UUO) suppressed the expression of α-smooth muscle actin, collagen deposition, and hydroxyproline in the UUO kidneys of rats. Moreover, CpG-ODN not only decreased the infiltration of macrophages but also inhibited the expression of chemokines CCL2 and CCL5, the Th2 cytokine IL-13, and the profibrogenic cytokines transforming growth factor (TGF)-ß1 and plasminogen activator inhibitor (PAI)-1 in UUO kidneys of rats. Importantly, therapeutic administration of CpG-ODN (10 microg/mouse, ip, every 3 days from the 4th day to 21st day after UUO) reversed the established renal fibrosis, which was accompanied by significant reductions in the activity of ERK, Smad3, and Stat3 and an increase in the activity of p38 kinase. CONCLUSION: the activation of TLR9 by CpG-ODN attenuates UUO-induced renal fibrosis by reversing an immunosuppressive microenvironment in the fibrotic renal tissue, which might be a novel therapeutic strategy against fibrotic renal diseases.


Assuntos
Rim/patologia , Oligodesoxirribonucleotídeos/uso terapêutico , Receptor Toll-Like 9/agonistas , Obstrução Ureteral/patologia , Actinas/metabolismo , Animais , Colágeno/metabolismo , Fibrose , Interleucina-13/metabolismo , Rim/metabolismo , Túbulos Renais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta1/metabolismo , Obstrução Ureteral/metabolismo
19.
Eur J Pharmacol ; 644(1-3): 17-23, 2010 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-20599907

RESUMO

Glycogen synthase kinase-3beta (GSK3beta) is a major negative modulator of cardiac hypertrophy. Here we report that GSK3beta physically and functionally interacts with Smad3. The interaction between GSK3beta and Smad3 may participate in the negative regulation of transforming growth factor beta1 (TGF-beta1) and Angiotensin II-induced transcription and apoptosis. GSK3beta interacted directly with Smad3 to sequester it outside the nucleus and prevent its nuclear translocation. This resulted in the suppression of Smad3-mediated transcriptional activity and gene expression. GSK3beta counteracted the pro-apoptotic effect of Smad3 and attenuated Angiotensin II-induced apoptosis in cardiac myocytes. Furthermore, stimulation of these cells with TGF-beta1 and Angiotensin II led to the endogenous Smad3 disassociating from GSK3beta and inactivating GSK3beta by phosphorylation of its Ser9. These results uncovered a novel mechanism for the GSK3beta negative regulation of TGF-beta1/Smad3 and Angiotensin II/Smad3-mediated transcription and apoptosis by the identification of a crosstalk between GSK3beta and Smad3 signal pathway.


Assuntos
Angiotensina II/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Apoptose/fisiologia , Linhagem Celular , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta , Humanos , Miócitos Cardíacos/metabolismo , Fosforilação , Ratos , Transdução de Sinais , Transcrição Gênica
20.
Cardiovasc Res ; 88(1): 140-9, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20542874

RESUMO

AIMS: Innate and adaptive immune responses are associated with the development of hypertension-induced myocardial hypertrophy and fibrosis. As a result, we investigated whether heat shock protein (HSP) 70, which is a molecule of damage-associated molecular patterns, could induce inflammation in the myocardium and promote the development of hypertension-induced cardiac hypertrophy and fibrosis. METHODS AND RESULTS: We found that HSP70 serum levels, as well as the amount of HSP70 translocation to the cardiomyocyte membranes and the interstitial space, were elevated in the hypertensive mice caused by abdominal aortic constriction (AAC). Transcriptional inhibition of HSP70 expression by a specific heat shock transcript factor inhibitor, KNK437, reduced the serum level, and the re-distribution of HSP70. It promoted myocardial hypertrophy and cardiac dysfunctions although it protected animals from AAC-induced cardiac fibrosis. On the other hand, the functional antagonism of HSP70 by an anti-HSP70 antibody attenuated AAC-induced cardiac hypertrophy and fibrosis without adverse haemodynamic effects. The cardioprotective effect of the anti-HSP70 antibody was largely attributed to its ability to block AAC-activated immune response in the heart, as was indicated by suppressing the hypertension-enhanced conjugation of HSP70 with toll-like receptor 4, reducing heart-infiltrating macrophages, decreasing the expression of pro-inflammatory factor monocyte chemoattractant protein-1 and profibrotic factor transforming growth factor beta 1, and attenuating pro-hypertrophy signal MAPK P38 and ERK. CONCLUSION: These results indicate that intracellular and extracellular HSP70 have different roles in the regulation of cardiac remodelling and function in response to hypertension. Extracellular HSP70 is a potential therapeutic target against cardiac hypertrophy and fibrosis.


Assuntos
Pressão Sanguínea , Cardiomegalia/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Hipertensão/metabolismo , Miocárdio/metabolismo , Remodelação Ventricular , Angiotensina II/metabolismo , Animais , Anticorpos/administração & dosagem , Compostos Benzidrílicos/administração & dosagem , Cardiomegalia/imunologia , Cardiomegalia/fisiopatologia , Quimiocina CCL2/metabolismo , Modelos Animais de Doenças , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibrose , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/sangue , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/imunologia , Hipertensão/imunologia , Hipertensão/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Miocárdio/imunologia , Miocárdio/patologia , Transporte Proteico , Pirrolidinonas/administração & dosagem , Transdução de Sinais , Fatores de Tempo , Receptor 4 Toll-Like/metabolismo , Transcrição Gênica , Fator de Crescimento Transformador beta1/metabolismo , Remodelação Ventricular/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
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