RESUMO
Platelets play a crucial role in the physiology of primary hemostasis and pathological processes such as arterial thrombosis; thus, developing a therapeutic target that prevents platelet activation can reduce arterial thrombosis. Pterostilbene (PTE) has remarkable pharmacological activities, including anticancer and neuroprotection. Few studies have reported the effects of pterostilbene on platelet activation. Thus, we examined the inhibitory mechanisms of pterostilbene in human platelets and its role in vascular thrombosis prevention in mice. At low concentrations (2-8 µM), pterostilbene strongly inhibited collagen-induced platelet aggregation. Furthermore, pterostilbene markedly diminished Lyn, Fyn, and Syk phosphorylation and hydroxyl radical formation stimulated by collagen. Moreover, PTE directly hindered integrin αIIbß3 activation through interfering with PAC-1 binding stimulated by collagen. In addition, pterostilbene affected integrin αIIbß3-mediated outside-in signaling, such as integrin ß3, Src, and FAK phosphorylation, and reduced the number of adherent platelets and the single platelet spreading area on immobilized fibrinogen as well as thrombin-stimulated fibrin clot retraction. Furthermore, pterostilbene substantially prolonged the occlusion time of thrombotic platelet plug formation in mice. This study demonstrated that pterostilbene exhibits a strong activity against platelet activation through the inhibition of integrin αIIbß3-mediated inside-out and outside-in signaling, suggesting that pterostilbene can serve as a therapeutic agent for thromboembolic disorders.
Assuntos
Plaquetas/metabolismo , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/efeitos dos fármacos , Estilbenos/metabolismo , Animais , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Retração do Coágulo/efeitos dos fármacos , Colágeno , Fibrinogênio/metabolismo , Hemostasia/efeitos dos fármacos , Humanos , Integrina alfa2/efeitos dos fármacos , Integrina alfa2/metabolismo , Integrina beta3/efeitos dos fármacos , Integrina beta3/metabolismo , Integrinas/efeitos dos fármacos , Integrinas/metabolismo , Camundongos , Selectina-P/metabolismo , Fosforilação , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estilbenos/farmacologia , Trombose/metabolismoRESUMO
T7 peptide is considered as an antiangiogenic polypeptide. The presents study aimed to further detect the antiangiogenic mechanisms of T7 peptide and determine whether combining T7 peptide and meloxicam (COX-2/PGE2 specific inhibitor) could offer a better therapy to combat hepatocellular carcinoma (HCC). T7 peptide suppressed the proliferation, migration, tube formation, and promoted the apoptosis of endothelial cells under both normoxic and hypoxic conditions via integrin α3ß1 and αvß3 pathways. Cell proliferation, migration, apoptosis, or tube formation ability were detected, and the expression of integrin-associated regulatory proteins was detected. The anti-tumor activity of T7 peptide, meloxicam, and their combination were evaluated in HCC tumor models established in mice. T7 peptide suppressed the proliferation, migration, tube formation, and promoted the apoptosis of endothelial cells under both normoxic and hypoxic conditions via integrin α3ß1 and αvß3 pathways. Meloxicam enhanced the activity of T7 peptide under hypoxic condition. T7 peptide partly inhibited COX-2 expression via integrin α3ß1 not αvß3-dependent pathways under hypoxic condition. T7 peptide regulated apoptosis associated protein through MAPK-dependent and -independent pathways under hypoxic condition. The MAPK pathway was activated by the COX-2/PGE2 axis under hypoxic condition. The combination of T7 and meloxicam showed a stronger anti-tumor effect against HCC tumors in mice. The data highlight that meloxicam enhanced the antiangiogenic activity of T7 peptide in vitro and in vivo.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Colágeno Tipo IV/farmacologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona/antagonistas & inibidores , Neoplasias Hepáticas/tratamento farmacológico , Meloxicam/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Ciclo-Oxigenase 2/metabolismo , Combinação de Medicamentos , Células Endoteliais/efeitos dos fármacos , Humanos , Hipóxia/patologia , Integrinas/efeitos dos fármacos , Camundongos , Neovascularização Patológica/tratamento farmacológico , RNA Interferente Pequeno/metabolismo , Distribuição Aleatória , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Opioids play a pivotal role in pain transmission but are also able to modulate immune cell functions. In the last decades a connection between opioids and integrins-adhesion molecules involved, among many other processes, in leukocyte recruitment at inflamed site-has been established. To study immune cell integrin-mediated adhesion, cell adhesion assay is a simple, reproducible, and valuable tool capable of unraveling concentration-dependent effects of a test candidate on integrin-mediated cell adhesion.
Assuntos
Moléculas de Adesão Celular/metabolismo , Adesão Celular/efeitos dos fármacos , Imuno-Histoquímica/métodos , Analgésicos Opioides/metabolismo , Analgésicos Opioides/farmacologia , Animais , Adesão Celular/fisiologia , Moléculas de Adesão Celular/efeitos dos fármacos , Humanos , Fatores Imunológicos/farmacologia , Inflamação/metabolismo , Integrinas/efeitos dos fármacos , Integrinas/metabolismo , Células Jurkat , Leucócitos/metabolismo , Células U937RESUMO
Active targeting strategies are currently being extensively investigated in order to enhance the selectivity of photodynamic therapy. The aim of the present research was to evaluate whether the external decoration of nanopolymeric carriers with targeting peptides could add more value to a photosensitizer formulation and increase antitumor therapeutic efficacy and selectivity. To this end, we assessed PLGA-PLA-PEG nanoparticles (NPs) covalently attached to a hydrophilic photosensitizer 5-[4-azidophenyl]-10,15,20-tri-(N-methyl-4-pyridinium)porphyrinato zinc (II) trichloride (ZnTriMPyP) and also to c(RGDfK) peptides, in order to target αv ß3 integrin-expressing cells. In vitro phototoxicity investigations showed that the ZnTriMPyP-PLGA-PLA-PEG-c(RGDfK) nanosystem is effective at submicromolar concentrations, is devoid of dark toxicity, successfully targets αv ß3 integrin-expressing cells and is 10-fold more potent than related nanosystems where the PS is occluded instead of covalently bound.
Assuntos
Portadores de Fármacos , Nanopartículas , Neoplasias/tratamento farmacológico , Oligopeptídeos/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Polímeros/química , Linhagem Celular Tumoral , Humanos , Integrinas/efeitos dos fármacos , Cinética , Fármacos Fotossensibilizantes/uso terapêutico , Oxigênio Singlete/química , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
OBJECTIVES: This article reports a study of cell mechanics in patient-derived (primary) B-cell acute lymphocytic leukemia (ALL) cells treated with antibodies against integrins. Leukemia cell adhesion to stromal cells mediates chemotherapeutic drug resistance, also known as cell adhesion-mediated chemotherapeutic drug resistance. We have previously shown that antibodies against integrin α4 and α6 adhesion molecules can de-adhere ALL cells from stromal cells or counter-receptors. Because drug-resistant cells are more deformable, as evaluated by single-beam acoustic tweezers, we hypothesized that changes in cell mechanics might contribute to the de-adhesive effect of integrin-targeting antibodies. METHODS: In this study, the deformability of primary pre-B ALL cells was evaluated by single-beam acoustic tweezers after treatments with the de-adhering antibody Tysabri or P5G10 against integrin α4 and α6 adhesion molecules. RESULTS: We demonstrated that primary ALL cells treated with P5G10 expressed decreased deformability compared with immunoglobulin G1 -treated control cells (P < .05). Tysabri did not show an effect on deformability (P > .05). CONCLUSIONS: These results suggest that decreased deformability is associated with an integrin α6 blockade. Further assessments of the functional roles of deformability and integrin blockades in B-ALL cell drug resistance and deformability, respectively, are necessary.
Assuntos
Adesão Celular/efeitos dos fármacos , Fatores Imunológicos/uso terapêutico , Integrinas/efeitos dos fármacos , Natalizumab/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico por imagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Acústica , Células Cultivadas , Humanos , Imunoglobulina G/administração & dosagem , Ultrassonografia/métodosRESUMO
Despite the great progress in the development of targeted therapies for different types of cancer utilizing monoclonal antibodies (e.g., cetuximab for colorectal cancer and head and neck cancer therapy), kinase inhibitors (e.g., sorafenib for kidney cancer and gastrointestinal stromal tumours therapy), and immunomodulatory treatments (e.g., nivolumab and pembrolizumab for melanoma therapy and lung cancer therapy), there is still a need to search for new, more effective treatments. Integrins are responsible for intercellular adhesion and interaction with the cellular matrix. The function of integrins is related to the transduction of intracellular signals associated with adhesion, migration, cell proliferation, differentiation, and apoptosis. Molecules targeting integrins that lead to cancer cell death have been developed. The most advanced molecules studied in clinical trials are abituzumab, intetumumab and cilengitide. There are different groups of anti-integrin drugs: monoclonal antibodies (e.g., abituzumab) and other such as cilengitide, E7820 and MK-0429. These drugs have been evaluated in various cancer types. However, they have shown modest efficacy, and none of them have yet been approved for cancer treatment. Studies have shown that patient selection using biomarkers might improve the efficacy of anti-integrin cancer treatment. Many preclinical models have demonstrated promising results using integrin visualization for cancer detection and treatment efficacy monitoring; however, these strategies require further evaluation in humans.
Assuntos
Antineoplásicos/farmacologia , Integrinas/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Antineoplásicos/uso terapêutico , Ensaios Clínicos como Assunto , HumanosRESUMO
SUMMARY: An alternative superovulator to replace clomiphene citrate is needed as clomiphene citrate is associated with low pregnancy rates. Anastrozole is an effective superovulator, but it has not been well researched. In order to determine the effectiveness of anastrozole as a superovulator and to compare it with clomiphene citrate in similar situations, this study ascertained the effects of these drugs on the expression of the focal adhesion proteins, vinculin and integrin β5, which are uterine receptivity markers, in the uterine epithelial cells of day 1 and day 6 pregnant Wistar rats. The results show that vinculin and integrin β5 are co-localized at the base of the uterine epithelium at day 1 of pregnancy whereas at day 6, they disassemble from the basal focal adhesions and co-localize and significantly increase their expression apically (p≤0.0001). Moreover, there is a significant difference in the protein expression levels of vinculin and integrin b5 in uterine luminal epithelial cells between untreated (control) and chlomiphene citrate treated rats (p≤0.0001), anastrozole and chlomiphene citrate treated rats at day 6 (p≤0.0001) suggesting the interpretation that anastrozole seems to enhance their expression in order to perhaps assist in the implantation process of the blastocyst. The immunofluorescence experiments agree with the vinculin and integrin β5 gene expression findings in which at day 6 of pregnancy, vinculin and integrin β5 gene expression are significantly upregulated in uterine luminal epithelial cells in the anastrozole treated group relative to the calibrator sample (p≤0.0001). These findings suggest that anastrozole is implantation friendly.
RESUMEN: Es necesario un superovulador alternativo para reemplazar el citrato de clomifeno, debido a que está asociado con bajas tasas de preñez. El anastrozol es un superovulador eficaz, sin embargo es poca su investigación. Con el fin de determinar la efectividad del anastrozol como superovulador y compararlo con citrato de clomifeno en situaciones similares, se determinaron los efectos de estos fármacos sobre la expresión de las proteínas de adhesión focal, vinculina e integrina β5, en marcadores de receptividad uterina en días 1 y 6, en las células epiteliales uterinas de ratas Wistar preñadas. Los resultados muestran que la vinculina y la integrina β5 se co-localizan en la base del epitelio uterino al día 1 de la gravidez mientras que al día 6 se desmontan de las adherencias focales basales, co-localizan y aumentan significativamente su expresión apicalmente (p≤0.0001). Además, existe una diferencia significativa en los niveles de expresión de proteína de vinculina e integrina β5 en células epiteliales luminales uterinas entre ratas no tratadas (control) y tratadas con citrato declomifeno (p≤0.0001), ratas tratadas con anastrozol y citrato declomifeno al día 6 (p≤0,0001) sugiriendo la interpretación de que el anastrozol parece mejorar su expresión con el fin de ayudar en el proceso de implantación del blastocisto. Los experimentos de inmunofluorescencia coinciden con los resultados de la expresión de los genes vinculina e integrina β5 en los cuales al día 6 de la preñez, la vinculina y la integrina β5 están significativamente reguladas en células epiteliales luminales uterinas en el grupo tratado con anastrozol con respecto a la muestra del calibrador (p<0,0001). Estos hallazgos sugieren que el anastrozol es favorable para la implantación.
Assuntos
Animais , Feminino , Gravidez , Ratos , Integrinas/efeitos dos fármacos , Nitrilas/farmacologia , Triazóis/farmacologia , Útero/efeitos dos fármacos , Vinculina/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Adesões Focais/efeitos dos fármacos , Integrinas/genética , Integrinas/fisiologia , Microscopia Confocal , Microscopia de Fluorescência , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Vinculina/genética , Vinculina/fisiologiaRESUMO
In an endeavor to search for affordable and safer therapeutics against debilitating visceral leishmaniasis, we examined antileishmanial potential of ammonium trichloro [1,2-ethanediolato-O,O']-tellurate (AS101); a tellurium based non toxic immunomodulator. AS101 showed significant in vitro efficacy against both Leishmania donovani promastigotes and amastigotes at sub-micromolar concentrations. AS101 could also completely eliminate organ parasite load from L. donovani infected Balb/c mice along with significant efficacy against infected hamsters (Ë93% inhibition). Analyzing mechanistic details revealed that the double edged AS101 could directly induce apoptosis in promastigotes along with indirectly activating host by reversing T-cell anergy to protective Th1 mode, increased ROS generation and anti-leishmanial IgG production. AS101 could inhibit IL-10/STAT3 pathway in L. donovani infected macrophages via blocking α4ß7 integrin dependent PI3K/Akt signaling and activate host MAPKs and NF-κB for Th1 response. In silico docking and biochemical assays revealed AS101's affinity to form thiol bond with cysteine residues of trypanothione reductase in Leishmania promastigotes leading to its inactivation and inducing ROS-mediated apoptosis of the parasite via increased Ca2+ level, loss of ATP and mitochondrial membrane potential along with metacaspase activation. Our findings provide the first evidence for the mechanism of action of AS101 with excellent safety profile and suggest its promising therapeutic potential against experimental visceral leishmaniasis.
Assuntos
Etilenos/uso terapêutico , Integrinas/antagonistas & inibidores , Leishmania donovani/enzimologia , Leishmaniose Visceral/tratamento farmacológico , NADH NADPH Oxirredutases/efeitos dos fármacos , Animais , Células Cultivadas , Cricetinae , Modelos Animais de Doenças , Etilenos/farmacologia , Feminino , Interações Hospedeiro-Parasita/efeitos dos fármacos , Integrinas/efeitos dos fármacos , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/metabolismo , Leishmaniose Visceral/metabolismo , Leishmaniose Visceral/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NADH NADPH Oxirredutases/metabolismo , Oxirredução/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/efeitos dos fármacos , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
D-mannose, a C-2 epimer of glucose, exists naturally in many plants and fruits, and is found in human blood at concentrations less than one-fiftieth of that of glucose. However, although the roles of glucose in T cell metabolism, diabetes and obesity are well characterized, the function of D-mannose in T cell immune responses remains unknown. Here we show that supraphysiological levels of D-mannose safely achievable by drinking-water supplementation suppressed immunopathology in mouse models of autoimmune diabetes and airway inflammation, and increased the proportion of Foxp3+ regulatory T cells (Treg cells) in mice. In vitro, D-mannose stimulated Treg cell differentiation in human and mouse cells by promoting TGF-ß activation, which in turn was mediated by upregulation of integrin αvß8 and reactive oxygen species generated by increased fatty acid oxidation. This previously unrecognized immunoregulatory function of D-mannose may have clinical applications for immunopathology.
Assuntos
Colite/imunologia , Diabetes Mellitus Tipo 1/imunologia , Pneumopatias/imunologia , Pulmão/efeitos dos fármacos , Manose/farmacologia , Pâncreas/efeitos dos fármacos , Hipersensibilidade Respiratória/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Fator de Crescimento Transformador beta/efeitos dos fármacos , Transferência Adotiva , Animais , Colo/efeitos dos fármacos , Suplementos Nutricionais , Modelos Animais de Doenças , Ácidos Graxos/metabolismo , Citometria de Fluxo , Fatores de Transcrição Forkhead/metabolismo , Humanos , Técnicas In Vitro , Inflamação , Integrinas/efeitos dos fármacos , Integrinas/imunologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Pulmão/imunologia , Pneumopatias/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Ovalbumina/efeitos adversos , Oxirredução/efeitos dos fármacos , Pâncreas/imunologia , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Hipersensibilidade Respiratória/induzido quimicamente , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/efeitos dos fármacos , Baço/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/imunologia , Regulação para CimaRESUMO
Cadmium (Cd) is a carcinogenic heavy metal which is implicated in breast cancer development. While the mechanisms of Cd-induced breast cancer initiation and promotion have been studied, the molecular processes involved in breast cancer progression remain to be investigated. The purpose of the present study was to evaluate the influence of Cd on metastasis-associated phenotypes, such as cell adhesion, migration, and invasion in triple-negative breast cancer cells. Treatment of MDA-MB-231 cells with 1µM Cd increased cell spreading and cell migration. This was associated with the activation of integrin ß1, FAK, Src, and Rac1. Treatment with Cd also inhibited GSK3ß activity and induced T-cell factor/lymphoid enhancer factor (TCF/LEF) transcription, indicating the involvement of ß-catenin signaling. Furthermore, treatment with 3µM Cd for 4weeks increased the expression of ß-catenin and enhanced TCF/LEF-mediated transcription. Furthermore, enhanced expressions of integrins α5 and ß1, paxillin, and vimentin indicated that prolonged Cd treatment reorganized the cytoskeleton, which aided malignancy, as evidenced by enhanced matrix metalloprotease 2/9 (MMP2/9) secretion and cell invasion. Prolonged Cd treatment also caused an increase in cell growth. Together, these results indicate that Cd alters key signaling processes involved in the regulation of cytoskeleton to enhance cancer cell migration, invasion, adhesion, and proliferation.
Assuntos
Cádmio/toxicidade , Integrinas/efeitos dos fármacos , Metástase Neoplásica/patologia , Transdução de Sinais/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , beta Catenina/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Fenótipo , Cicatrização/efeitos dos fármacosRESUMO
The gut microbiome plays a central role in inflammatory bowel diseases (IBDs) pathogenesis and propagation. To determine whether the gut microbiome may predict responses to IBD therapy, we conducted a prospective study with Crohn's disease (CD) or ulcerative colitis (UC) patients initiating anti-integrin therapy (vedolizumab). Disease activity and stool metagenomes at baseline, and weeks 14, 30, and 54 after therapy initiation were assessed. Community α-diversity was significantly higher, and Roseburia inulinivorans and a Burkholderiales species were more abundant at baseline among CD patients achieving week 14 remission. Several significant associations were identified with microbial function; 13 pathways including branched chain amino acid synthesis were significantly enriched in baseline samples from CD patients achieving remission. A neural network algorithm, vedoNet, incorporating microbiome and clinical data, provided highest classifying power for clinical remission. We hypothesize that the trajectory of early microbiome changes may be a marker of response to IBD treatment.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Terapia Biológica , Microbioma Gastrointestinal/fisiologia , Doenças Inflamatórias Intestinais/terapia , Butiratos/metabolismo , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Fezes/química , Fezes/microbiologia , Humanos , Integrinas/efeitos dos fármacos , Metagenoma , Estudos Prospectivos , Resultado do TratamentoRESUMO
Therapeutic compounds interfering with T cell trafficking are a new column of inflammatory bowel disease (IBD) treatment. Currently, the anti-α4ß7 integrin antibody vedolizumab is successfully used in the clinic and further drugs are likely to follow. Despite these clinical advances, the precise mechanistic background of their action is only gradually elucidated and still a matter of intensive research. Only recently, advances made with the help of new in vivo models and human studies have contributed to shape our concept of T cell trafficking in IBD by deciphering some important and so far unanswered questions. At the same time, basic and clinical data have generated new issues to be addressed on the way toward a clear perception of trafficking mechanisms and toward elucidation of the action of compounds interfering with this process. In this review, we will give a comprehensive outline of all components of T cell trafficking in regard to IBD before discussing the current knowledge concerning targeted interference with integrins in this complex network. Moreover, we will summarize remaining ambiguity and give an outlook on potential future targets.
Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Fármacos Gastrointestinais/farmacologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Integrinas/imunologia , Linfócitos T/imunologia , Animais , Humanos , Doenças Inflamatórias Intestinais/imunologia , Integrinas/efeitos dos fármacos , Intestinos/imunologiaRESUMO
Steroid refractory acute graft-versus-host-disease of the gut is a serious complication associated with high mortality after allogeneic stem cell transplantation. Treatment options are limited and not predictably effective. We describe the treatment of steroid-refractory acute graft-versus-host-disease with vedolizumab, an antibody directed against integrin α4ß7, in 6 patients. All patients responded, and 4 of 6 patients are alive with a median follow-up of 10 months.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Integrinas/efeitos dos fármacos , Enteropatias/tratamento farmacológico , Adulto , Feminino , Fármacos Gastrointestinais/uso terapêutico , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Salvação/métodos , Esteroides/uso terapêutico , Transplante Homólogo , Resultado do TratamentoRESUMO
BACKGROUND AND PURPOSE: Recombinant osteopontin (rOPN) has been reported to be neuroprotective in stroke animal models. The purpose of this study is to investigate a potential role and mechanism of nasal administration of rOPN on preserving the vascular smooth muscle phenotype in early brain injury after subarachnoid hemorrhage (SAH). METHODS: One hundred and ninety-two male adult Sprague-Dawley rats were used. The SAH model was induced by endovascular perforation. Integrin-linked kinase small interfering RNA was intracerebroventricularly injected 48 hours before SAH. The integrin receptor antagonist fibronectin-derived peptide Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP), focal adhesion kinase inhibitor Fib-14, and Rac-1 inhibitor NSC23766 were administered 1 hour before SAH induction. rOPN was administered via the intracerebroventricular and nasal route after SAH. SAH grade, neurological scores, brain water content, brain swelling, hematoxylin and eosin staining, India ink angiography, Western blots, and immunofluorescence were used to study the mechanisms of rOPN on the vascular smooth muscle phenotypic transformation. RESULTS: The marker proteins of vascular smooth muscle phenotypic transformation α-smooth muscle actin decreased and embryonic smooth muscle myosin heavy chain (SMemb) increased significantly at 24 and 72 hours in the cerebral arteries after SAH. rOPN prevented the changes of α-smooth muscle actin and SMemb and significantly alleviated neurobehavioral dysfunction, increased the cross-sectional area and the lumen diameter of the cerebral arteries, reduced the brain water content and brain swelling, and improved the wall thickness of cerebral arteries. These effects of rOPN were abolished by GRGDSP, integrin-linked kinase small interfering RNA, and NSC23766. Intranasal application of rOPN at 3 hours after SAH also reduced neurological deficits. CONCLUSIONS: rOPN prevented the vascular smooth muscle phenotypic transformation and improved the neurological outcome, which was possibly mediated by the integrin receptor/integrin-linked kinase/Rac-1 pathway.
Assuntos
Artérias Cerebrais/efeitos dos fármacos , Integrinas/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Osteopontina/farmacologia , Proteínas Serina-Treonina Quinases/efeitos dos fármacos , Hemorragia Subaracnóidea/tratamento farmacológico , Proteínas rac1 de Ligação ao GTP/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Masculino , Fármacos Neuroprotetores/administração & dosagem , Osteopontina/administração & dosagem , Fenótipo , Ratos , Ratos Sprague-Dawley , Proteínas RecombinantesRESUMO
Cell migration is a stepwise process that coordinates multiple molecular machineries. Using in vitro angiogenesis screens with short interfering RNA and chemical inhibitors, we define here a MAP4K4-moesin-talin-ß1-integrin molecular pathway that promotes efficient plasma membrane retraction during endothelial cell migration. Loss of MAP4K4 decreased membrane dynamics, slowed endothelial cell migration, and impaired angiogenesis in vitro and in vivo. In migrating endothelial cells, MAP4K4 phosphorylates moesin in retracting membranes at sites of focal adhesion disassembly. Epistasis analyses indicated that moesin functions downstream of MAP4K4 to inactivate integrin by competing with talin for binding to ß1-integrin intracellular domain. Consequently, loss of moesin (encoded by the MSN gene) or MAP4K4 reduced adhesion disassembly rate in endothelial cells. Additionally, α5ß1-integrin blockade reversed the membrane retraction defects associated with loss of Map4k4 in vitro and in vivo. Our study uncovers a novel aspect of endothelial cell migration. Finally, loss of MAP4K4 function suppressed pathological angiogenesis in disease models, identifying MAP4K4 as a potential therapeutic target.
Assuntos
Movimento Celular , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Integrinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Motivos de Aminoácidos , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Forma Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Epistasia Genética , Adesões Focais/metabolismo , Humanos , Integrina alfa1/efeitos dos fármacos , Integrina alfa1/metabolismo , Integrina beta1/química , Integrina beta1/efeitos dos fármacos , Integrina beta1/metabolismo , Integrinas/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Camundongos , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Neovascularização Patológica , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Talina/química , Talina/metabolismoRESUMO
BACKGROUND: Integrin αvß6 promotes migration, invasion, and survival of cancer cells; however, the relevance and role of αvß6 has yet to be elucidated in breast cancer. METHODS: Protein expression of integrin subunit beta6 (ß6) was measured in breast cancers by immunohistochemistry (n > 2000) and ITGB6 mRNA expression measured in the Molecular Taxonomy of Breast Cancer International Consortium dataset. Overall survival was assessed using Kaplan Meier curves, and bioinformatics statistical analyses were performed (Cox proportional hazards model, Wald test, and Chi-square test of association). Using antibody (264RAD) blockade and siRNA knockdown of ß6 in breast cell lines, the role of αvß6 in Human Epidermal Growth Factor Receptor 2 (HER2) biology (expression, proliferation, invasion, growth in vivo) was assessed by flow cytometry, MTT, Transwell invasion, proximity ligation assay, and xenografts (n ≥ 3), respectively. A student's t-test was used for two variables; three-plus variables used one-way analysis of variance with Bonferroni's Multiple Comparison Test. Xenograft growth was analyzed using linear mixed model analysis, followed by Wald testing and survival, analyzed using the Log-Rank test. All statistical tests were two sided. RESULTS: High expression of either the mRNA or protein for the integrin subunit ß6 was associated with very poor survival (HR = 1.60, 95% CI = 1.19 to 2.15, P = .002) and increased metastases to distant sites. Co-expression of ß6 and HER2 was associated with worse prognosis (HR = 1.97, 95% CI = 1.16 to 3.35, P = .01). Monotherapy with 264RAD or trastuzumab slowed growth of MCF-7/HER2-18 and BT-474 xenografts similarly (P < .001), but combining 264RAD with trastuzumab effectively stopped tumor growth, even in trastuzumab-resistant MCF-7/HER2-18 xenografts. CONCLUSIONS: Targeting αvß6 with 264RAD alone or in combination with trastuzumab may provide a novel therapy for treating high-risk and trastuzumab-resistant breast cancer patients.
Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Antígenos de Neoplasias/efeitos dos fármacos , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Integrinas/efeitos dos fármacos , Integrinas/metabolismo , Terapia de Alvo Molecular , Receptor ErbB-2/metabolismo , Animais , Antígenos de Neoplasias/genética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Integrinas/genética , Estimativa de Kaplan-Meier , Camundongos , Camundongos SCID , Terapia de Alvo Molecular/métodos , Receptor ErbB-2/genética , Trastuzumab , Resultado do Tratamento , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The treatment of invasive candidiasis associated with growing numbers of immunocompromised patients remains a major challenge complicated by increasing drug resistance. A novel class of branched histidine-lysine (bHK) peptides has promising antifungal activity, and exhibits a mechanism similar to natural histatins, and thus may avoid drug resistance. The present studies evaluate ligand targeting of bHK peptides to fungal surface integrins by determining whether a cyclic RGD (cRGD) peptide with a large PEG linker could enhance bHK peptide antifungal activity. Whereas conjugates containing only the PEG linker reduced bHK peptide activity, conjugates with the cRGD-PEG ligand resulted in marked enhancement of activity against Candida albicans. This study provides the first demonstration of benefit from ligand targeting of antifungal agents to fungal surface receptors.
Assuntos
Antifúngicos/farmacologia , Sistemas de Liberação de Medicamentos , Histidina/análise , Integrinas/efeitos dos fármacos , Peptídeos/farmacologia , Candida albicans/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peptídeos/química , Polietilenoglicóis/químicaRESUMO
In systemic sclerosis (SSc), a common and aetiologically mysterious form of scleroderma (defined as pathological fibrosis of the skin), previously healthy adults acquire fibrosis of the skin and viscera in association with autoantibodies. Familial recurrence is extremely rare and causal genes have not been identified. Although the onset of fibrosis in SSc typically correlates with the production of autoantibodies, whether they contribute to disease pathogenesis or simply serve as a marker of disease remains controversial and the mechanism for their induction is largely unknown. The study of SSc is hindered by a lack of animal models that recapitulate the aetiology of this complex disease. To gain a foothold in the pathogenesis of pathological skin fibrosis, we studied stiff skin syndrome (SSS), a rare but tractable Mendelian disorder leading to childhood onset of diffuse skin fibrosis with autosomal dominant inheritance and complete penetrance. We showed previously that SSS is caused by heterozygous missense mutations in the gene (FBN1) encoding fibrillin-1, the main constituent of extracellular microfibrils. SSS mutations all localize to the only domain in fibrillin-1 that harbours an Arg-Gly-Asp (RGD) motif needed to mediate cell-matrix interactions by binding to cell-surface integrins. Here we show that mouse lines harbouring analogous amino acid substitutions in fibrillin-1 recapitulate aggressive skin fibrosis that is prevented by integrin-modulating therapies and reversed by antagonism of the pro-fibrotic cytokine transforming growth factor ß (TGF-ß). Mutant mice show skin infiltration of pro-inflammatory immune cells including plasmacytoid dendritic cells, T helper cells and plasma cells, and also autoantibody production; these findings are normalized by integrin-modulating therapies or TGF-ß antagonism. These results show that alterations in cell-matrix interactions are sufficient to initiate and sustain inflammatory and pro-fibrotic programmes and highlight new therapeutic strategies.