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1.
PLoS One ; 18(2): e0281827, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36795774

RESUMO

Large gulls are generalist predators that play an important role in Arctic food webs. Describing the migratory patterns and phenology of these predators is essential to understanding how Arctic ecosystems function. However, from all six large Arctic gull taxa, including three long-distance migrants, to date seasonal movements have been studied only in three and with small sample sizes. To document the flyways and migratory behaviour of the Vega gull, a widespread but little-studied Siberian migrant, we monitored 28 individuals with GPS loggers over a mean period of 383 days. Birds used similar routes in spring and autumn, preferring coastal to inland or offshore routes, and travelled 4000-5500 km between their breeding (Siberia) and wintering grounds (mainly the Republic of Korea and Japan). Spring migration mainly occurred in May, and was twice as fast and more synchronized among individuals than autumn migration. Migration bouts mainly occurred during the day and twilight, but rates of travel were always higher during the few night flights. Flight altitudes were nearly always higher during migration bouts than during other bouts, and lower during twilight than during night or day. Altitudes above 2000m were recorded during migrations, when birds made non-stop inland flights over mountain ranges and vast stretches of the boreal forest. Individuals showed high inter-annual consistency in their movements in winter and summer, indicating strong site fidelity to their breeding and wintering sites. Within-individual variation was similar in spring and autumn, but between individual variation was higher in autumn than in spring. Compared to previous studies, our results suggest that the timing of spring migration in large Arctic gulls is likely constrained by snowmelt at breeding grounds, while the duration of migration windows could be related to the proportion of inland versus coastal habitats found along their flyways ('fly-and-forage' strategy). Ongoing environmental changes are hence likely in short term to alter the timing of their migration, and in long term possibly affect the duration if e.g. the resource availability along the route changes in the future.


Assuntos
Charadriiformes , Animais , Ecossistema , Migração Animal , Aves , Estações do Ano
2.
Melanoma Res ; 32(1): 1-10, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34939980

RESUMO

Macrophage inhibitory cytokine-1 (MIC-1) has been reported to be elevated in various human cancers including melanoma; however, the function of MIC-1 in cancer remains unclear. In this study, we attempt to clarify the role of MIC-1 in tumor pathogenesis by employing the orthotopic B16F1 melanoma mouse model in which serum MIC-1 levels are positively correlated with tumor size. By stably transfecting a MIC-1 expression construct into B16F1 melanoma cells, we increased the expression and secretion levels of MIC-1. This increase in MIC-1 expression significantly enhanced the growth of tumors derived from B16F1 cells in vivo, despite not affecting in vitro cell growth. The elevated MIC-1 expression in B16F1 cells also resulted in lymph node metastasis in B16F1 tumor-bearing mice, significantly increasing mortality. Interestingly, among small melanoma tumors of similar size, tumors derived from the MIC-1-transfected B16F1 cells exhibited enhanced blood vessel formation compared with those of mock transfectant cells. Also, more MIC-1 was found in well-vascularized tumor regions than in poorly vascularized tumor regions. Moreover, conditioned medium (CM) of the MIC-1-transfected melanoma cells enhanced the angiogenic properties of endothelial cells more than CM of mock transfectant cells. Notably, hypoxic culture conditions forced parental B16F1 cells to secrete more endothelial cell-stimulating factors, among which the function of MIC-1 was confirmed by blocking the effects with an anti-MIC-1 antibody. Taken together, these results suggest that the MIC-1 produced by melanoma cells in response to oxygen deprivation promotes tumor vascularization during melanoma development in vivo, leading to enhanced tumor growth and metastasis.


Assuntos
Fator 15 de Diferenciação de Crescimento/metabolismo , Melanoma/genética , Neoplasias Cutâneas/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Melanoma/patologia , Camundongos , Metástase Neoplásica , Neovascularização Patológica , Neoplasias Cutâneas/patologia , Transfecção
3.
J Endovasc Ther ; 28(4): 636-641, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33998350

RESUMO

PURPOSE: Common celiomesenteric trunk (CMT) is a rare anatomical variation that occurs in 0.5% to 3.4% of the general population. Its presence may complicate planning and implantation of fenestrated and branched stent-grafts because the wide diameter and short length of the CMT to its bifurcation does not allow sufficient sealing for placement of bridging stents. CASE REPORT: We report a patient with thoracoabdominal aortic aneurysm (TAAA) and CMT treated by fenestrated-branched endovascular aortic repair (FB-EVAR) using double kissing directional branches to incorporate the celiac axis and superior mesenteric artery. Pitfalls of stent design and implantation are outlined. CONCLUSION: Double kissing directional branches should be considered as an alternative to incorporate vessels with early bifurcation such as a CMT.


Assuntos
Aneurisma da Aorta Torácica , Implante de Prótese Vascular , Procedimentos Endovasculares , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/cirurgia , Prótese Vascular , Procedimentos Endovasculares/efeitos adversos , Humanos , Desenho de Prótese , Fatores de Risco , Stents , Fatores de Tempo , Resultado do Tratamento
4.
J Cell Physiol ; 236(5): 4008-4023, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33151561

RESUMO

Macrophage inhibitory cytokine-1 (MIC-1) is a cytokine with pleotropic actions and its expression is markedly increased by inflammation and cardiac injury and in cancers. In particular, MIC-1 production after cardiac ischemia injury is associated with enhanced cardiac angiogenesis as well as myocardial protection. However, it remains uncertain whether MIC-1 itself has proangiogenic activity. In this study, we tried to determine the precise role of MIC-1 in physiological and pathological angiogenesis. Human microvessel endothelial cells responded to MIC-1 with enhanced angiogenic behaviors. Employing various angiogenesis assays, MIC-1 was found to promote vessel formation and development with a potency similar to that of vascular endothelial growth factor (VEGF). MIC-1 transgenic (Tg) mice also displayed enhanced neovascularization in both developing embryos and neonatal mouse retinas, compared with wild-type mice. Furthermore, endothelial cells (ECs) isolated from MIC-1 Tg mouse lung exhibited higher angiogenic potential than ECs from wild-type lung. MIC-1-induced angiogenesis was also observed in the recovery or healing processes of injuries such as hindlimb ischemia and skin wounds in mice. However, unlike VEGF, MIC-1 induced neither endothelial inflammation nor increased vascular permeability. In ECs, the MIC-1 signal exerted proangiogenic actions via the MEK/extracellular signal-regulated kinase- and phosphatidylinositol 3-kinase/Akt-dependent pathways. Notably, these MIC-1 signaling events in ECs were abrogated by small interfering RNA-mediated knockdown of GFRAL, suggesting that GFRAL is an EC receptor for MIC-1. In summary, we here show a novel role of MIC-1 as a potent EC activator, which promotes both normal and injury-related angiogenesis.


Assuntos
Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Fator 15 de Diferenciação de Crescimento/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Neovascularização Fisiológica , Transdução de Sinais , Animais , Embrião de Mamíferos/metabolismo , Membro Posterior/irrigação sanguínea , Membro Posterior/patologia , Humanos , Inflamação/patologia , Isquemia/patologia , Sistema de Sinalização das MAP Quinases , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microvasos/citologia , Permeabilidade , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regeneração/fisiologia , Retina/metabolismo , Pele/patologia , Cicatrização
5.
Cancers (Basel) ; 12(10)2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050232

RESUMO

The epidermal growth factor receptor (EGFR), a member of ErbB receptor tyrosine kinase (RTK) family, is activated through growth factor-induced reorganization of the actin cytoskeleton and subsequent dimerization. We herein explored the molecular mechanism underlying the suppression of ligand-induced EGFR dimerization by CD99 agonists and its relevance to tumor growth in vivo. Epidermal growth factor (EGF) activated the formation of c-Src/focal adhesion kinase (FAK)-mediated intracellular complex and subsequently induced RhoA-and Rac1-mediated actin remodeling, resulting in EGFR dimerization and endocytosis. In contrast, CD99 agonist facilitated FAK dephosphorylation through the HRAS/ERK/PTPN12 signaling pathway, leading to inhibition of actin cytoskeletal reorganization via inactivation of the RhoA and Rac1 signaling pathways. Moreover, CD99 agonist significantly suppressed tumor growth in a BALB/c mouse model injected with MDA-MB-231 human breast cancer cells. Taken together, these results indicate that CD99-derived agonist ligand inhibits epidermal growth factor (EGF)-induced EGFR dimerization through impairment of cytoskeletal reorganization by PTPN12-dependent c-Src/FAK inactivation, thereby suppressing breast cancer growth.

6.
Vasc Endovascular Surg ; 54(1): 5-11, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31506033

RESUMO

INTRODUCTION: High flow rates may develop in arteriovenous fistula (AVF), resulting in clinical syndromes of steal, aneurysmal fistula, or high-output cardiac failure. Various techniques with varying success have been advocated to treat this difficult problem. We present a hemodynamically validated novel banding technique. METHODS: We designed a computational fluid dynamic (CFD) model of the native high-flow AVF and tested various juxta-anastomotic venous diameters to determine the effect on AVF blood flow and pressure. We translated this principle in our banding technique, wherein adjustable banding was performed in conjunction with ultrasound-guided brachial artery flow measurement to determine the optimal band diameter. Polyurethane patch was used to fashion the adjustable band. Patient demographics, AVF flow parameters pre- and postintervention, operative intervention, and ultrasound follow-up data were collected prospectively. RESULTS: Our CFD testing demonstrated that the band diameter needed to achieve optimal distal blood pressure and preserve AVF flow depending on blood pressure, end capillary pressure, venous pressure, and vascular diameters. Five patients subsequently underwent dynamic banding of symptomatic high-flow AVF. Mean brachial artery blood flow rates pre- and postbanding were 2964 mL/min (confidence interval [CI]: 1487-4440 mL/min) and 1099 mL/min (CI: 571.7-1627 mL/min), respectively (P = .01). All patients had symptomatic improvement, and at a mean follow-up of 1 year, this benefit was sustained with no AVF thrombosis or loss. CONCLUSION: Adjustable dynamic band using ultrasound-guided brachial artery flow shows promising results in producing accurate AVF blood flow reduction with sustained efficacy in the short term for patients with symptomatic high-flow AVF.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Artéria Braquial/fisiopatologia , Hemodinâmica , Complicações Pós-Operatórias/cirurgia , Diálise Renal , Adolescente , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Artéria Braquial/diagnóstico por imagem , Simulação por Computador , Humanos , Ligadura , Pessoa de Meia-Idade , Modelos Cardiovasculares , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/fisiopatologia , Estudos Prospectivos , Fluxo Sanguíneo Regional , Reoperação , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia de Intervenção
7.
Mol Pharmacol ; 96(6): 692-701, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31594790

RESUMO

The tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a vascular endothelial growth factor (VEGF) receptor-2 antagonist, has been used previously either alone or in combination with chemotherapeutic drugs for treating colorectal cancer in a mouse model. We analyzed the half-life of the peptide and found that because of degradation by aminopeptidases B and N, it had a short half-life of 1.2 hours in the serum. Therefore, to increase the stability and potency of the peptide, we designed the modified peptide, N-terminally acetylated RLYE (Ac-RLYE), which had a strongly stabilized half-life of 8.8 hours in serum compared with the original parent peptide. The IC50 value of Ac-RLYE for VEGF-A-induced endothelial cell migration decreased to approximately 37.1 pM from 89.1 pM for the parent peptide. Using a mouse xenograft tumor model, we demonstrated that Ac-RLYE was more potent than RLYE in inhibiting tumor angiogenesis and growth, improving vascular integrity and normalization through enhanced endothelial cell junctions and pericyte coverage of the tumor vasculature, and impeding the infiltration of macrophages into tumor and their polarization to the M2 phenotype. Furthermore, combined treatment of Ac-RLYE and irinotecan exhibited synergistic effects on M1-like macrophage activation and apoptosis and growth inhibition of tumor cells. These findings provide evidence that the N-terminal acetylation augments the therapeutic effect of RLYE in solid tumors via inhibition of tumor angiogenesis, improvement of tumor vessel integrity and normalization, and enhancement of the livery and efficacy of the coadministered chemotherapeutic drugs. SIGNIFICANCE STATEMENT: The results of this study demonstrate that the N-terminal acetylation of the tetrapeptide RLYE (Ac-RLYE), a novel vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor, significantly improves its serum stability, antiangiogenic activity, and vascular normalizing potency, resulting in enhanced therapeutic effect on solid tumors. Furthermore, the combined treatment of Ac-RLYE with the chemotherapeutic drug, irinotecan, synergistically enhanced its antitumor efficacy by improving the perfusion and delivery of the drug into the tumors and stimulating the conversion of the tumor-associated macrophages to an immunostimulatory M1-like antitumor phenotype.


Assuntos
Antineoplásicos/administração & dosagem , Neovascularização Patológica/sangue , Neovascularização Patológica/tratamento farmacológico , Oligopeptídeos/administração & dosagem , Peptídeo Hidrolases/sangue , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Células HCT116 , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Nus , Estabilidade Proteica/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
8.
Prostate ; 79(12): 1400-1411, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31212375

RESUMO

BACKGROUND: The epithelial-to-mesenchymal transition (EMT) is closely associated with cancer invasion and metastasis. Since the transforming growth factor ß (TGF-ß) and Wnt signals induce EMT in various epithelial cell types, we examined whether and how the CD82/KAI1 metastasis suppressor affects the TGF-ß and Wnt signal-dependent EMT in human prostate cancer cells. METHODS: The invasiveness of cancer cells was evaluated by examining their ability to pass through the basement membrane matrigel. The subcellular localizations of Smad4 and ß-catenin proteins were respectively examined by confocal microscopy following immunofluorescence antibody staining and immunoblotting analysis following subcellular fractionation. The transcriptional activities of the TGF-ß1 -responsive TRE and Wnt-responsive Tcf/Lef promoters were determined by a luciferase reporter assay following transfection of the recombinant reporter vector into the cell. RESULTS: TGF-ß1 and Wnt3a treatments of human prostate cancer cells without CD82 expression resulted in not only increased invasiveness but also EMT involving the development of motile structures, downregulation of E-cadherin, and upregulation of the mesenchymal proteins. However, in the cells with high levels of CD82, the TGF-ß1 and Wnt3a stimulations neither elevated invasiveness nor induced EMT. Furthermore, the TGF-ß1 signaling events occurring in the CD82-deficient cells, such as phosphorylation of Smad2, nuclear translocation of Smad4, and transactivation of the TRE promoter, did not take place in the high CD82-expressing cells. Further, high CD82 expression interfered with the Wnt signal-dependent alterations in the phosphorylation pattern of glycogen synthase kinase 3ß (GSK-3ß) in prostate cancer cells, which allowed GSK-3ß to continue phosphorylating ß-catenin, thereby attenuating the Wnt signaling effects on the nuclear translocation of ß-catenin and subsequent transactivation of the Tcf/Lef promoter. CONCLUSIONS: The results of the present study suggest that CD82/KAI1 functions in suppressing TGF-ß1 - and Wnt-induced EMT in prostate cancer cells by inhibiting the TGF-ß1 /Smad and Wnt/ß-catenin pathways. Therefore, loss or decrease of CD82 expression is likely to render prostate cancer cells prone to respond to the TGF-ß1 and Wnt signals with EMT, resulting in the development of a motile and invasive mesenchymal phenotype related to the initiation of the metastatic cascade.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Proteína Kangai-1/metabolismo , Próstata/patologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Próstata/metabolismo , Proteína Smad2/metabolismo , Via de Sinalização Wnt
9.
J Biol Chem ; 293(49): 18989-19000, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30279269

RESUMO

Inflammatory cytokines, including tumor necrosis factor-α (TNFα), were elevated in patients with cardiovascular diseases and are also considered as crucial factors in the pathogenesis of preeclampsia; however, the underlying pathogenic mechanism has not been clearly elucidated. This study provides novel evidence that TNFα leads to endothelial dysfunction associated with hypertension and vascular remodeling in preeclampsia through down-regulation of endothelial nitric-oxide synthase (eNOS) by NF-κB-dependent biogenesis of microRNA (miR)-31-5p, which targets eNOS mRNA. In this study, we found that miR-31-5p was up-regulated in sera from patients with preeclampsia and in human endothelial cells treated with TNFα. TNFα-mediated induction of miR-31-5p was blocked by an NF-κB inhibitor and NF-κB p65 knockdown but not by mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase inhibitors, indicating that NF-κB is essential for biogenesis of miR-31-5p. The treatment of human endothelial cells with TNFα or miR-31-5p mimics decreased endothelial nitric-oxide synthase (eNOS) mRNA stability without affecting eNOS promoter activity, resulting in inhibition of eNOS expression and NO/cGMP production through blocking of the functional activity of the eNOS mRNA 3'-UTR. Moreover, TNFα and miR-31-5p mimic evoked endothelial dysfunction associated with defects in angiogenesis, trophoblastic invasion, and vasorelaxation in an ex vivo cultured model of human placental arterial vessels, which are typical features of preeclampsia. These results suggest that NF-κB-responsive miR-31-5p elicits endothelial dysfunction, hypertension, and vascular remodeling via post-transcriptional down-regulation of eNOS and is a molecular risk factor in the pathogenesis and development of preeclampsia.


Assuntos
Células Endoteliais/fisiologia , MicroRNAs/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Pré-Eclâmpsia/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Artérias/efeitos dos fármacos , Regulação para Baixo , Células Endoteliais/efeitos dos fármacos , Feminino , Técnicas de Silenciamento de Genes , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/farmacologia , Subunidade p50 de NF-kappa B/genética , Subunidade p50 de NF-kappa B/metabolismo , Neovascularização Fisiológica , Placenta/irrigação sanguínea , Placenta/efeitos dos fármacos , Pré-Eclâmpsia/genética , Gravidez , Trofoblastos/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
10.
Cell Signal ; 52: 83-94, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30189244

RESUMO

Tetraspanin membrane proteins form physical complexes with signaling molecules and have been suggested to influence the signaling events of associated molecules. Of the tetraspanin proteins, CD82 has been shown to promote homotypic cell-cell adhesion, which partially accounts for its role in suppressing cancer invasion and metastasis. We found here that CD82-induced cell-cell adhesion is attributed to increased E-cadherin expression through CD82-mediated downregulation of the E-cadherin repressor Snail. The Snail repression by CD82 resulted from the reduced binding of the Sp1 transcription factor to the Snail gene promoter. Notably, high CD82 expression did not allow the fibronectin matrix to induce Sp1 phosphorylation, implicating CD82 inhibition of the fibronectin-integrin signaling-dependent Sp1 activation. Meanwhile, E-cadherin upregulated by CD82 pulled ß-catenin up to the membrane region, and consequently reduced the amount of cytoplasmic ß-catenin that was able to move into to the nucleus. The Wnt signal-induced nuclear translocation of ß-catenin was also inhibited by the CD82 function of upregulating E-cadherin. Overall, high CD82 expression was likely to suppress fibronectin adhesion-induced Sp1 activation signaling for Snail expression, resulting in continuous E-cadherin expression, which contributed not only to the maintenance of strong cell-cell adhesion but also to the blockage of nuclear ß-catenin signaling.


Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Adesão Celular , Proteína Kangai-1/fisiologia , Neoplasias da Próstata/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Fator de Transcrição Sp1/metabolismo , beta Catenina/metabolismo , Linhagem Celular Tumoral , Fibronectinas/metabolismo , Humanos , Integrinas/metabolismo , Masculino , Via de Sinalização Wnt
11.
Oncotarget ; 8(38): 63155-63176, 2017 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-28968979

RESUMO

The regulatory role of suppressor of cytokine signaling 1 (SOCS1) in inflammation has been reported. However, its role in allergic inflammation has not been previously reported. SOCS1 mediated in vitro and in vivo allergic inflammation. Histone deacetylase-3 (HDAC3), a mediator of allergic inflammation, interacted with SOCS1, and miR-384 inhibitor, a positive regulator of HDAC3, induced features of allergic inflammation in an SOCS1-dependent manner. miRNA array analysis showed that the expression of miR-122 was decreased by antigen-stimulation. TargetScan analysis predicted the binding of miR-122 to the 3'-UTR of SOCS1. miR-122 inhibitor induced in vitro and in vivo allergic features in SOCS1-dependent manner. SOCS1 was necessary for allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells. SOCS1 and miR-122 regulated cellular interactions involving cancer cells, mast cells and macrophages during allergic inflammation. SOCS1 mimetic peptide, D-T-H-F-R-T-F-R-S-H-S-D-Y-R-R-I, inhibited in vitro and in vivo allergic inflammation, allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells, and cellular interactions during allergic inflammation. Janus kinase 2 (JAK2) exhibited binding to SOCS1 mimetic peptide and mediated allergic inflammation. Transforming growth factor- Δ1 (TGF-Δ1) was decreased during allergic inflammation and showed an anti-allergic effect. SOCS1 and JAK2 regulated the production of anti-allergic TGF-Δ1. Taken together, our results show that miR-122-SOCS1 feedback loop can be employed as a target for the development of anti-allergic and anti-cancer drugs.

12.
Free Radic Biol Med ; 112: 567-577, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28888620

RESUMO

Ligation of the death receptors for TNF-α, FasL, and TRAIL triggers two common pathways, caspase-dependent intrinsic apoptosis and intracellular reactive oxygen species (ROS) generation. The apoptotic pathway is well characterized; however, a signaling linker between the death receptor and ROS production has not been clearly elucidated. Here, we found that death receptor-induced ROS generation was strongly inhibited by mitochondrial complex I and II inhibitors, but not by inhibitors of NADPH oxidase, lipoxygenase, cyclooxygenase or xanthine oxidase, indicating that ROS are mostly generated by the impairment of the mitochondrial respiratory chain. ROS generation was accompanied by caspase-8 activation, Bid cleavage, and cytochrome c release; it was blocked in FADD- and caspase-8-deficient cells, as well as by caspase-8 knockdown and inhibitor. Moreover, Bid knockdown abrogated TNF-α- or TRAIL-induced ROS generation, whereas overexpression of truncated Bid (tBid) or knockdown of cytochrome c spontaneously elevated ROS production. In addition, p53-overexpressing cells accumulated intracellular ROS via cytochrome c release mediated by the BH3-only protein Noxa induction. In a cell-free reconstitution system, caspase-8-mediated Bid cleavage and recombinant tBid induced mitochondrial cytochrome c release and ROS generation, which were blocked by Bcl-xL and antioxidant enzymes. These data suggest that anti-apoptotic Bcl-2 proteins play an important role in mitochondrial ROS generation by preventing cytochrome c release. These data provide evidence that the FADD/caspase-8/Bid/cytochrome c axis is a crucial linker between death receptors and mitochondria, where they play a role in ROS generation and apoptosis.


Assuntos
Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Caspase 8/genética , Citocromos c/genética , Mitocôndrias Hepáticas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspase 8/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Proteína de Domínio de Morte Associada a Fas/genética , Proteína de Domínio de Morte Associada a Fas/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Células Jurkat , Fígado/citologia , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
13.
Mol Cell Biol ; 37(14)2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28483911

RESUMO

The human CD99 protein is a 32-kDa glycosylated transmembrane protein that regulates various cellular responses, including cell adhesion and leukocyte extravasation. We previously reported that CD99 activation suppresses ß1 integrin activity through dephosphorylation of focal adhesion kinase (FAK) at Y397. We explored a molecular mechanism underlying the suppression of ß1 integrin activity by CD99 agonists and its relevance to tumor growth in vivo CD99-Fc fusion proteins or a series of CD99-derived peptides suppressed ß1 integrin activity by specifically interacting with three conserved motifs of the CD99 extracellular domain. CD99CRIII3, a representative CD99-derived 3-mer peptide, facilitated protein kinase A-SHP2 interaction and subsequent activation of the HRAS/RAF1/MEK/ERK signaling pathway. Subsequently, CD99CRIII3 induced FAK phosphorylation at S910, which led to the recruitment of PTPN12 and PIN1 to FAK, followed by FAK dephosphorylation at Y397. Taken together, these results indicate that CD99-derived agonist ligands inhibit fibronectin-mediated ß1 integrin activation through the SHP2/ERK/PTPN12/FAK signaling pathway.


Assuntos
Adesão Celular/fisiologia , Movimento Celular/fisiologia , Fibronectinas/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Cadeias beta de Integrinas/metabolismo , Transdução de Sinais , Antígeno 12E7/metabolismo , Linhagem Celular Tumoral , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Ligantes , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 12/metabolismo , Transdução de Sinais/fisiologia
14.
Curr Biol ; 27(10): R376-R377, 2017 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-28535385

RESUMO

While wild goose populations wintering in North America and Europe are mostly flourishing by exploiting farmland, those in China (which seem confined to natural wetlands) are generally declining. Telemetry devices were attached to 67 wintering wild geese of five different species at three important wetlands in the Yangtze River Floodplain (YRF), China to determine habitat use. 50 individuals of three declining species were almost entirely diurnally confined to natural wetlands; 17 individuals from two species showing stable trends used wetlands 83% and 90% of the time, otherwise resorting to farmland. These results confirm earlier studies linking declines among Chinese wintering geese to natural habitat loss and degradation affecting food supply. These results also contribute to explaining the poor conservation status of Chinese wintering geese compared to the same and other goose species wintering in adjacent Korea and Japan, western Europe and North America, which feed almost entirely on agricultural land, liberating them from winter population limitation.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Gansos/fisiologia , Animais , China , Gansos/classificação , Dinâmica Populacional , Estações do Ano
15.
Mol Cells ; 40(5): 363-370, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28535665

RESUMO

Extrahepatic cholangiocarcinoma (ECC), a malignant tumor of biliary origin, has a poor prognosis with limited treatment options. The KRAS oncogene is the most commonly mutated gene in ECC and one of the factors that predicts a poor prognosis and low survival rate. L1 cell adhesion molecule (L1CAM) is expressed in ECC cells and acts as an independent poor prognostic factor in predicting patient survival. In this study we investigate the functional significance of L1CAM in ECC cells with activating KRAS mutation. We selected an ECC cell line, EGI-1, with activating KRAS mutation, and then confirmed its expression of L1CAM by RT-PCR, western blot analysis, and flow cytometry. The suppression of L1CAM expression (using a specific lentivirus-delivered shRNA) significantly decreased the migratory and invasive properties of EGI-1 cells, without altering their proliferation or survival. Analyses of signaling effectors in L1CAM-depleted and control EGI-1 cells indicated that L1CAM suppression decreased the levels of both phosphorylated MKK4 and total MKK4, together with c-Jun N-terminal kinase (JNK) phosphorylation. Further, exposure to a JNK inhibitor (SP600125) decreased migration and invasion of EGI-1 cells. These results suggest that L1CAM promotes cellular migration and invasion via the induction of MKK4 expression, leading to JNK activation. Our study is the first to demonstrate a functional role for L1CAM in ECC carrying the activating KRAS mutation. Given that KRAS is the most commonly mutated oncogene in ECC, L1CAM may serve as an attractive therapeutic target for ECC cells with activating KRAS mutation.


Assuntos
Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/patologia , Sistema de Sinalização das MAP Quinases/genética , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Antracenos/farmacologia , Neoplasias dos Ductos Biliares/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Colangiocarcinoma/metabolismo , Ativação Enzimática , Técnicas de Silenciamento de Genes , Humanos , MAP Quinase Quinase 4/antagonistas & inibidores , MAP Quinase Quinase 4/metabolismo , Mutação , Molécula L1 de Adesão de Célula Nervosa/genética , Inibidores de Proteínas Quinases/farmacologia , RNA Interferente Pequeno/genética
16.
Oncotarget ; 8(8): 13632-13651, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28099142

RESUMO

We previously reported the role of cancer/testis antigen CAGE in the response to anti-cancer drugs. CAGE increased the expression of cyclinD1, and pGSK3ßSer9, an inactive GSK3ß, while decreasing the expression of phospho-cyclinD1Thr286. CAGE showed binding to GSK3ß and the domain of CAGE (amino acids 231-300) necessary for binding to GSK3ß and for the expression regulation of cyclinD1 was determined. 269GTGKT273 peptide, corresponding to the DEAD box helicase domain of CAGE, decreased the expression of cyclinD1 and pGSK3ßSer9 while increasing the expression of phospho-cyclinD1Thr286. GTGKT peptide showed the binding to CAGE and prevented CAGE from binding to GSK3ß. GTGKT peptide changed the localization of CAGE and inhibited the binding of CAGE to the promoter sequences of cyclin D1. GTGKT peptide enhanced the apoptotic effects of anti-cancer drugs and decreased the migration, invasion, angiogenic, tumorigenic and metastatic potential of anti-cancer drug-resistant cancer cells. We found that Lys272 of GTGKT peptide was necessary for conferring anti-cancer activity. Peptides corresponding to the DEAD box helicase domain of CAGE, such as AQTGTGKT, QTGTGKT and TGTGKT, also showed anti-cancer activity by preventing CAGE from binding to GSK3ß. GTGKT peptide showed ex vivo tumor homing potential. Thus, peptides corresponding to the DEAD box helicase domain of CAGE can be developed as anti-cancer drugs in cancer patients expressing CAGE.


Assuntos
Antineoplásicos/farmacologia , Ciclina D1/biossíntese , RNA Helicases DEAD-box/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Oligopeptídeos/farmacologia , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Ciclina D1/genética , RNA Helicases DEAD-box/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Regiões Promotoras Genéticas , Domínios Proteicos
17.
Oncotarget ; 8(7): 11763-11777, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28052029

RESUMO

The tetrapeptide Arg-Leu-Tyr-Glu (RLYE) is known to inhibit vascular endothelial growth factor-A (VEGF-A)-induced angiogenesis in vitro. Herein, we examined its underlying mechanism and antitumor activity associated with vascular remodeling. RLYE inhibited VEGF-A-induced angiogenesis in a mouse model and suppressed VEGF-A-induced angiogenic signal cascades in human endothelial cells. However, RLYE showed no inhibitory effect on VEGF-A-induced proliferation and migration of multiple myeloma cells expressing VEGF receptor (VEGFR)-1, but not VEGFR-2. In addition, RLYE showed no inhibitory effect on angiogenic activities induced by VEGF-B, basic fibroblast growth factor, epithermal growth factor, sphingosine-1-phosphate, and placental growth factor. RLYE bound specifically to VEGFR-2 at the VEGF-A binding site, thereby blocking VEGF-A-VEGFR-2 binding and VEGF-A-induced VEGFR-2 internalization. The RLYE peptide inhibited tumor growth and metastasis via suppression of tumor angiogenesis in tumor-bearing mice. Moreover, RLYE showed a synergistic effect of the cytotoxic agent irinotecan on tumor cell apoptosis and tumor progression via tumor vessel normalization due to stabilization of VE-cadherin-mediated adherens junction, improvement of pericyte coverage, and inhibition of vascular leakage in tumors. Our results suggest that RLYE can be used as an antiangiogenic and tumor blood vessel remodeling agent for inhibition of tumor growth and metastasis by antagonizing VEGFR-2, with the synergistic anti-cancer effect via enhancement of drug delivery and therapeutic efficacy.


Assuntos
Inibidores da Angiogênese/farmacologia , Neoplasias do Colo/tratamento farmacológico , Melanoma Experimental/tratamento farmacológico , Oligopeptídeos/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Permeabilidade Capilar/efeitos dos fármacos , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/metabolismo , Progressão da Doença , Células HCT116 , Humanos , Masculino , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Neovascularização Patológica/tratamento farmacológico , Ratos Sprague-Dawley , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
18.
Free Radic Biol Med ; 104: 185-198, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28087411

RESUMO

Preeclampsia is an inflammatory disease with endothelial cell dysfunction that occurs via decreased endothelial nitric oxide synthase/nitric oxide (eNOS/NO) activity. Aspirin reduces the incidence of hypertensive pregnancy complications. However, the underlying mechanism has not been clearly explained. Here, we found that tumor necrosis factor (TNF)-α, microRNA (miR)-155, and eNOS levels as well as endothelial redox phenotype were differentially regulated in preeclamptic patients, implying the involvement of TNF-α- and redox signal-mediated miR-155 biogenesis and eNOS downregulation in the pathogenesis of preeclampsia. Aspirin prevented the TNF-α-mediated increase in miR-155 biogenesis and decreases in eNOS expression and NO/cGMP production in cultured human umbilical vein endothelial cells (HUVECs). Similar effects of aspirin were also observed in HUVECs treated with H2O2. The preventive effects of aspirin was associated with the inhibition of nuclear factor-κB (NF-κB)-dependent MIR155HG (miR-155 host gene) expression. Aspirin recovered the TNF-α-mediated decrease in wild-type, but not mutant, eNOS 3'-untranslated region reporter activity, whose effect was blocked by miR-155 mimic. Moreover, aspirin prevented TNF-α-mediated endothelial cell dysfunction associated with impaired vasorelaxation, angiogenesis, and trophoblast invasion, and the preventive effects were blocked by miR-155 mimic or an eNOS inhibitor. Aspirin rescued TNF-α-mediated eNOS downregulation coupled with endothelial dysfunction by inhibiting NF-κB-dependent transcriptional miR-155 biogenesis. Thus, the redox-sensitive NF-κB/miR-155/eNOS axis may be crucial in the pathogenesis of vascular disorders including preeclampsia.


Assuntos
Aspirina/administração & dosagem , MicroRNAs/genética , Óxido Nítrico Sintase Tipo III/genética , Pré-Eclâmpsia/tratamento farmacológico , Fator de Necrose Tumoral alfa/genética , Adulto , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , NF-kappa B/genética , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , Transdução de Sinais , Transfecção , Fator de Necrose Tumoral alfa/metabolismo
19.
Front Vet Sci ; 4: 225, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312966

RESUMO

In the last few years, several reassortant subtypes of highly pathogenic avian influenza viruses (HPAI H5Nx) have emerged in East Asia. These new viruses, mostly of subtype H5N1, H5N2, H5N6, and H5N8 belonging to clade 2.3.4.4, have been found in several Asian countries and have caused outbreaks in poultry in China, South Korea, and Vietnam. HPAI H5Nx also have spread over considerable distances with the introduction of viruses belonging to the same 2.3.4.4 clade in the U.S. (2014-2015) and in Europe (2014-2015 and 2016-2017). In this paper, we examine the emergence and spread of these new viruses in Asia in relation to published datasets on HPAI H5Nx distribution, movement of migratory waterfowl, avian influenza risk models, and land-use change analyses. More specifically, we show that between 2000 and 2015, vast areas of northeast China have been newly planted with rice paddy fields (3.21 million ha in Heilongjiang, Jilin, and Liaoning) in areas connected to other parts of Asia through migratory pathways of wild waterfowl. We hypothesize that recent land use changes in northeast China have affected the spatial distribution of wild waterfowl, their stopover areas, and the wild-domestic interface, thereby altering transmission dynamics of avian influenza viruses across flyways. Detailed studies of the habitat use by wild migratory birds, of the extent of the wild-domestic interface, and of the circulation of avian influenza viruses in those new planted areas may help to shed more light on this hypothesis, and on the possible impact of those changes on the long-distance patterns of avian influenza transmission.

20.
Oncotarget ; 8(1): 1641-1654, 2017 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-27926483

RESUMO

The transmembrane protein CD82/KAI1 suppresses the metastatic potential of various cancer cell types. Moreover, decrease or loss of CD82 expression is closely associated with malignancy and poor prognosis in many human cancers including prostate cancer. Despite intense scrutiny, the mechanisms underlying the metastasis-suppressing role of CD82 are still not fully understood. Here, we found that a fibronectin matrix induced mesenchymal phenotypes in human prostate cancer cells with no or low CD82 expression levels. However, high CD82 expression rendered prostate cancer cells to have intensified epithelial characteristics upon fibronectin engagement, along with decreased cell motility and invasiveness. The CD82 function of inhibiting fibronectin-induced epithelial-to-mesenchymal transition (EMT) was dependent not only on CD82 interactions with fibronectin-binding α3ß1/α5ß1 integrins but also on the integrin-mediated intracellular signaling events. Notably, CD82 attenuated the FAK-Src and ILK pathways downstream of the fibronectin-receptor integrins. Immunofluorescence staining of human prostate cancer tissue specimens illustrated a negative association of CD82 with EMT-related gene expression as well as prostate malignancy. Altogether, these results suggest that CD82 suppresses EMT in prostate cancer cells adhered to the fibronectin matrix by repressing adhesion signaling through lateral interactions with the associated α3ß1 and α5ß1 integrins, leading to reduced cell migration and invasive capacities.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Fibronectinas/antagonistas & inibidores , Integrina alfa3beta1/metabolismo , Integrina alfa5beta1/metabolismo , Proteína Kangai-1/metabolismo , Neoplasias da Próstata/patologia , Transdução de Sinais/fisiologia , Caderinas/biossíntese , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Quinase 1 de Adesão Focal/antagonistas & inibidores , Humanos , Proteína Kangai-1/genética , Masculino , Metástase Neoplásica/patologia , Próstata/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Transdução de Sinais/genética , Fatores de Transcrição da Família Snail/biossíntese , Quinases da Família src/antagonistas & inibidores
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