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The lymphatic system is a major gateway for tumor cell dissemination but the mechanisms of how tumor cells gain access to lymphatic vessels are not completely understood. Breast cancer cells undergoing epithelial-mesenchymal transition (EMT) gain invasive and migratory properties. Overexpression of the cytokine transforming growth factor ß1 (TGFß1), a potent inducer of EMT, is frequently detected in the tumor microenvironment and correlates with invasion and lymph metastasis. Recently, we reported that TGFß1 stimulated breast cancer cells with mesenchymal properties to migrate in a targeted fashion towards the lymphatic system via CCR7/CCL21-mediated chemotaxis, similar to dendritic cells during inflammation. Here, we aimed to identify additional chemotactic factors and corresponding receptors that could be involved in guiding breast cancer cells through the lymphatic system. Through a combination of RNA sequencing analysis, database screening and invasion assays we identified IL7/IL7R and IL15/IL15R as pairs of chemokines and receptors with potential roles in promoting chemotactic migration of breast cancer cells with mesenchymal properties towards the lymphatics. The results demonstrate the capacity of TGFß1 to orchestrate crosstalk between tumor cells and lymphatic endothelial cells and warrant further studies to explore the roles of IL7 and IL15 in promoting lymph metastasis of breast cancer.
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Neoplasias de la Mama , Factores Quimiotácticos , Transición Epitelial-Mesenquimal , Vasos Linfáticos , Humanos , Células Endoteliales , Interleucina-15 , Interleucina-7 , Metástasis Linfática , Microambiente TumoralRESUMEN
Cancer represents a significant cause of death and suffering in both the developed and developing countries. Key underlying issues in the mortality of cancer are delayed diagnosis and resistance to treatments. However, improvements in biomarkers represent one important step that can be taken for alleviating the suffering caused by malignancy. Precision-based medicine is promising for revolutionizing diagnostic and treatment strategies for cancer patients worldwide. Contemporary methods, including various omics and systems biology approaches, as well as advanced digital imaging and artificial intelligence, allow more accurate assessment of tumor characteristics at the patient level. As a result, treatment strategies can be specifically tailored and adapted for individual and/or groups of patients that carry certain tumor characteristics. This includes immunotherapy, which is based on characterization of the immunosuppressive tumor microenvironment (TME) and, more specifically, the presence and activity of immune cell subsets. Unfortunately, while it is increasingly clear that gender strongly affects immune regulation and response, there is a knowledge gap concerning differences in sex-specific immune responses and how these contribute to the immunosuppressive TME and the response to immunotherapy. In fact, sex dimorphism is poorly understood in cancer progression and is typically ignored in current clinical practice. In this review, we aim to survey the available literature and highlight the existing knowledge gap in order to encourage further studies that would contribute to understanding both gender-biased immunosuppression in the TME and the driver of tumor progression towards invasive and metastatic disease. The review highlights the need to include sex optimized/genderized medicine as a new concept in future medicine cancer diagnostics and treatments.
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Neoplasias , Microambiente Tumoral , Masculino , Femenino , Humanos , Caracteres Sexuales , Inteligencia Artificial , Inmunoterapia/métodos , Neoplasias/diagnóstico , Neoplasias/etiología , Neoplasias/terapia , Factores InmunológicosRESUMEN
Tumor cells undergoing epithelial-mesenchymal transition (EMT) lose cell surface adhesion molecules and gain invasive and metastatic properties. EMT is a plastic process and tumor cells may shift between different epithelial-mesenchymal states during metastasis. However, how this is regulated is not fully understood. Syndecan-1 (SDC1) is the major cell surface proteoglycan in epithelial cells and has been shown to regulate carcinoma progression and EMT. Recently, it was discovered that SDC1 translocates into the cell nucleus in certain tumor cells. Nuclear SDC1 inhibits cell proliferation, but whether nuclear SDC1 contributes to the regulation of EMT is not clear. Here, we report that loss of nuclear SDC1 is associated with cellular elongation and an E-cadherin-to-N-cadherin switch during TGF-ß1-induced EMT in human A549 lung adenocarcinoma cells. Further studies showed that nuclear translocation of SDC1 contributed to the repression of mesenchymal and invasive properties of human B6FS fibrosarcoma cells. The results demonstrate that nuclear translocation contributes to the capacity of SDC1 to regulate epithelial-mesenchymal plasticity in human tumor cells and opens up to mechanistic studies to elucidate the mechanisms involved.
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Transforming growth factor beta 1 (TGF-ß1) is associated with epithelial-mesenchymal transition (EMT), lymph metastasis, and poor prognosis in breast cancer. Paradoxically, TGF-ß1 is also a potent inhibitor of cell proliferation. TGF-ß1-induced EMT involves activation of several pathways including AKT, which also regulates glucose uptake. Recent data show that prolonged TGF-ß1 exposure leads to a more stable EMT phenotype in breast cancer cells. However, whether this is linked to changes in glucose metabolism is not clear. Here, we used a model of TGF-ß1-induced EMT in mammary epithelial cells to study the regulation of Glut1 and EMT markers during the induction compared to a prolonged phase of EMT by western blot, immunofluorescence and qPCR analysis. We also measured cell proliferation and uptake of the glucose analogue 2-NDBG. We found that EMT induction was associated with decreased Glut1 expression and glucose uptake. These effects were linked to reduced cell proliferation rather than EMT. Knockdown of Glut1 resulted in growth inhibition and less induction of vimentin during TGF-ß1-induced EMT. Intriguingly, Glut1 levels, glucose uptake and cell proliferation were restored during prolonged EMT. The results link Glut1 repression to the anti-proliferative response of TGF-ß1 and indicate that re-expression of Glut1 during chronic TGF-ß1 exposure allows breast cancer cells to develop stable EMT and proliferate, in parallel.
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Neoplasias de la Mama/patología , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Transportador de Glucosa de Tipo 1/metabolismo , Glucosa/metabolismo , Factor de Crecimiento Transformador beta1/farmacología , Transporte Biológico/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , HumanosRESUMEN
Cystic fibrosis (CF) is a monogenetic disease resulting from mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene encoding an anion channel. Recent evidence indicates that CFTR plays a role in other cellular processes, namely in development, cellular differentiation and wound healing. Accordingly, CFTR has been proposed to function as a tumour suppressor in a wide range of cancers. Along these lines, CF was recently suggested to be associated with epithelial-mesenchymal transition (EMT), a latent developmental process, which can be re-activated in fibrosis and cancer. However, it is unknown whether EMT is indeed active in CF and if EMT is triggered by dysfunctional CFTR itself or a consequence of secondary complications of CF. In this study, we investigated the occurrence of EMT in airways native tissue, primary cells and cell lines expressing mutant CFTR through the expression of epithelial and mesenchymal markers as well as EMT-associated transcription factors. Transepithelial electrical resistance, proliferation and regeneration rates, and cell resistance to TGF-ß1induced EMT were also measured. CF tissues/cells expressing mutant CFTR displayed several signs of active EMT, namely: destructured epithelial proteins, defective cell junctions, increased levels of mesenchymal markers and EMT-associated transcription factors, hyper-proliferation and impaired wound healing. Importantly, we found evidence that the mutant CFTR triggered EMT was mediated by EMT-associated transcription factor TWIST1. Further, our data show that CF cells are over-sensitive to EMT but the CF EMT phenotype can be reversed by CFTR modulator drugs. Altogether, these results identify for the first time that EMT is intrinsically triggered by the absence of functional CFTR through a TWIST1 dependent mechanism and indicate that CFTR plays a direct role in EMT protection. This mechanistic link is a plausible explanation for the high incidence of fibrosis and cancer in CF, as well as for the role of CFTR as tumour suppressor protein.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Proteínas Nucleares/metabolismo , Oncogenes/genética , Proteína 1 Relacionada con Twist/metabolismo , Células Cultivadas , Transición Epitelial-Mesenquimal , Células HEK293 , HumanosRESUMEN
Multiple viruses are implicated in atherosclerosis, but the mechanisms by which they infect cells and contribute to plaque formation in arterial walls are not well understood. Based on reports showing the presence of enterovirus in atherosclerotic plaques we hypothesized that the coxsackievirus and adenovirus receptor (CXADR/CAR), although absent in normal arteries, could be induced during plaque formation. Large-scale microarray and mass spectrometric analyses revealed significant up-regulation of CXADR messenger RNA and protein levels in plaque-invested carotid arteries compared with control arteries. Macrophages were identified as a previously unknown cellular source of CXADR in human plaques and plaques from Ldr-/-Apob100/100 mice. CXADR was specifically associated with M1-polarized macrophages and foam cells and was experimentally induced during macrophage differentiation. Furthermore, it was significantly correlated with receptors for other viruses linked to atherosclerosis. The results show that CXADR is induced in macrophages during plaque formation, suggesting a mechanism by which enterovirus infect cells in atherosclerotic plaques.
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Proteína de la Membrana Similar al Receptor de Coxsackie y Adenovirus/metabolismo , Macrófagos/metabolismo , Placa Aterosclerótica/metabolismo , Animales , Arterias Carótidas/virología , Modelos Animales de Enfermedad , Enterovirus/patogenicidad , Humanos , Macrófagos/virología , Ratones , Ratones Noqueados , Placa Aterosclerótica/virología , ARN Mensajero/metabolismoRESUMEN
Syndecan-1 (SDC1) is a cell surface heparan sulfate proteoglycan (HSPG), which regulates various signaling pathways controlling the proliferation and migration of malignant mesothelioma and other types of cancer. We have previously shown that SDC1 can translocate to the nucleus in mesothelioma cells through a tubulin-dependent transport mechanism. However, the role of nuclear SDC1 is largely unknown. Here, we performed co-immunoprecipitation (Co-IP) of SDC1 in a mesothelioma cell line to identify SDC1 interacting proteins. The precipitates contained a large number of proteins, indicating the recovery of protein networks. Proteomic analysis with a focus on nuclear proteins revealed an association with pathways related to cell proliferation and RNA synthesis, splicing and transport. In support of this, the top RNA splicing candidates were verified to interact with SDC1 by Co-IP and subsequent Western blot analysis. Further loss- and gain-of-function experiments showed that SDC1 influences RNA levels in mesothelioma cells. The results identify a proteomic map of SDC1 nuclear interactors in a mesothelioma cell line and suggest a previously unknown role for SDC1 in RNA biogenesis. The results should serve as a fundament for further studies to discover the role of nuclear SDC1 in normal and cancer cells of different origin.
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Núcleo Celular/metabolismo , Mesotelioma/metabolismo , Proteómica/métodos , Sindecano-1/metabolismo , Línea Celular , Núcleo Celular/genética , Proliferación Celular , Mutación con Ganancia de Función , Regulación Neoplásica de la Expresión Génica , Humanos , Mutación con Pérdida de Función , Mesotelioma/genética , Mapas de Interacción de Proteínas , Empalme del ARN , Sindecano-1/genéticaRESUMEN
Epithelial-mesenchymal transition (EMT) encompasses dynamic changes in cellular organization from epithelial to mesenchymal phenotypes, which leads to functional changes in cell migration and invasion. EMT occurs in a diverse range of physiological and pathological conditions and is driven by a conserved set of inducing signals, transcriptional regulators and downstream effectors. With over 5,700 publications indexed by Web of Science in 2019 alone, research on EMT is expanding rapidly. This growing interest warrants the need for a consensus among researchers when referring to and undertaking research on EMT. This Consensus Statement, mediated by 'the EMT International Association' (TEMTIA), is the outcome of a 2-year-long discussion among EMT researchers and aims to both clarify the nomenclature and provide definitions and guidelines for EMT research in future publications. We trust that these guidelines will help to reduce misunderstanding and misinterpretation of research data generated in various experimental models and to promote cross-disciplinary collaboration to identify and address key open questions in this research field. While recognizing the importance of maintaining diversity in experimental approaches and conceptual frameworks, we emphasize that lasting contributions of EMT research to increasing our understanding of developmental processes and combatting cancer and other diseases depend on the adoption of a unified terminology to describe EMT.
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Investigación Biomédica/normas , Transición Epitelial-Mesenquimal , Animales , Movimiento Celular , Plasticidad de la Célula , Consenso , Biología Evolutiva/normas , Humanos , Neoplasias/patología , Terminología como AsuntoRESUMEN
Tight junctions (TJ) act as hubs for intracellular signaling pathways controlling epithelial cell fate and function. Deregulation of TJ is a hallmark of epithelial-mesenchymal transition (EMT), which contributes to carcinoma progression and metastasis. However, the signaling mechanisms linking TJ to the induction of EMT are not understood. Here, we identify a TJ-based signalosome, which controls AKT signaling and EMT in breast cancer. The coxsackie and adenovirus receptor (CXADR), a TJ protein with an essential yet uncharacterized role in organogenesis and tissue homeostasis, was identified as a key component of the signalosome. CXADR regulated the stability and function of the phosphatases and AKT inhibitors PTEN and PHLPP2. Loss of CXADR led to hyperactivation of AKT and sensitized cells to TGFß1-induced EMT. Conversely, restoration of CXADR stabilized PHLPP2 and PTEN, inhibited AKT, and promoted epithelial differentiation. Loss of CXADR in luminal A breast cancer correlated with loss of PHLPP2 and PTEN and poor prognosis. These results show that CXADR promotes the formation of an AKT-inhibitory signalosome at TJ and regulates epithelial-mesenchymal plasticity in breast cancer cells. Moreover, loss of CXADR might be used as a prognostic marker in luminal breast cancer. SIGNIFICANCE: The tight junction protein CXADR controls epithelial-mesenchymal plasticity in breast cancer by stabilizing the AKT regulators PTEN and PHLPP2.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/1/47/F1.large.jpg.
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Neoplasias de la Mama/patología , Proteína de la Membrana Similar al Receptor de Coxsackie y Adenovirus/metabolismo , Transición Epitelial-Mesenquimal , Regulación Neoplásica de la Expresión Génica , Uniones Estrechas/patología , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Diferenciación Celular , Movimiento Celular , Proteína de la Membrana Similar al Receptor de Coxsackie y Adenovirus/genética , Proteína de la Membrana Similar al Receptor de Coxsackie y Adenovirus/fisiología , Femenino , Perfilación de la Expresión Génica , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Pronóstico , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Tasa de Supervivencia , Uniones Estrechas/genética , Uniones Estrechas/metabolismo , Células Tumorales CultivadasRESUMEN
It was already in the 18th century when the French surgeon LeDran first noted that breast cancer patients with spread of tumor cells to their axillary lymph nodes had a drastically worse prognosis than patients without spread (LeDran et al., ). Since then, metastatic spread of cancer cells to regional lymph nodes has been established as the most important prognostic factor in many types of cancer (Carter et al., ; Elston and Ellis, ). However, despite its clinical importance, lymph metastasis remains an underexplored area of tumor biology. Fundamental questions, such as when, how, and perhaps most importantly, why tumor cells disseminate through the lymphatic system, remain largely unanswered. Accordingly, no treatment strategies exist that specifically target lymph metastasis. The identification of epithelial-mesenchymal transition (EMT) as a mechanism, which allows cancer cells to dedifferentiate and acquire enhanced migratory and invasive properties, has been a game changer in cancer research. Conceptually, EMT provides an explanation for why epithelial cancers with poor differentiation status are generally more aggressive and prone to metastasize than more differentiated cancers. Inflammatory cytokines, such as TGF-ß, which are produced and secreted by tumor-infiltrating immune cells, are potent inducers of EMT. Thus, reactivation of EMT also links cancer-related inflammation to invasive and metastatic disease. Recently, we found that breast cancer cells undergoing TGF-ß-induced EMT acquire properties of immune cells allowing them to disseminate in a targeted fashion through the lymphatic system similar to activated dendritic cells during inflammation. Here, we review our current understanding of the mechanisms by which cancer cells spread through the lymphatic system and the links to inflammation and the immune system. We also emphasize how imaging techniques have the potential to further expand our knowledge of the mechanisms of lymph metastasis, and how lymph nodes serve as an interface between cancer and the immune system.
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Transición Epitelial-Mesenquimal/inmunología , Ganglios Linfáticos/inmunología , Proteínas de Neoplasias/inmunología , Neoplasias/inmunología , Factor de Crecimiento Transformador beta/inmunología , Animales , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Neoplasias/patologíaRESUMEN
Individuals with a bicuspid aortic valve (BAV) are at significantly higher risk of developing aortic complications than individuals with tricuspid aortic valves (TAV) and defective signaling during the embryonic development and/or life time exposure to abnormal hemodynamic have been proposed as underlying factors. However, an explanation for the molecular mechanisms of aortopathy in BAV has not yet been provided. We combined proteomics, RNA analyses, immunohistochemistry, and electron microscopy to identify molecular differences in samples of non-dilated ascending aortas from BAV (N = 62) and TAV (N = 54) patients. Proteomic analysis was also performed for dilated aortas (N = 6 BAV and N = 5 TAV) to gain further insight into the aortopathy of BAV. Our results collectively showed the molecular signature of an endothelial/epithelial-mesenchymal (EndMT/EMT) transition-like process, associated with instability of intimal cell junctions and activation of RHOA pathway in the intima and media layers of ascending aorta in BAV patients. We propose that an improper regulation of EndMT/EMT during the spatiotemporally related embryogenesis of semilunar valves and ascending aorta in BAV individuals may result in aortic immaturity and instability prior to dilation. Exasperation of EndMT/EMT state in post embryonic life and/or exposure to non-physiological hemodynamic could lead to the aneurysm of ascending aorta in BAV individuals.
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Aneurisma de la Aorta/etiología , Enfermedades de las Válvulas Cardíacas/metabolismo , Enfermedades de las Válvulas Cardíacas/patología , Túnica Íntima/patología , Válvula Aórtica/anomalías , Válvula Aórtica/metabolismo , Válvula Aórtica/patología , Enfermedad de la Válvula Aórtica Bicúspide , Endocitosis , Transición Epitelial-Mesenquimal , Enfermedades de las Válvulas Cardíacas/complicaciones , Humanos , Arterias Mamarias/metabolismo , Arterias Mamarias/patología , Células Madre Mesenquimatosas/patología , Proteoma , Receptores Notch/metabolismo , Proteína de Unión al GTP rhoA/metabolismoRESUMEN
Tumors are composed of multiple cell types besides the tumor cells themselves, including innate immune cells such as macrophages. Tumor-associated macrophages (TAMs) are a heterogeneous population of myeloid cells present in the tumor microenvironment (TME). Here, they contribute to immunosuppression, enabling the establishment and persistence of solid tumors as well as metastatic dissemination. We have found that the pattern recognition scavenger receptor MARCO defines a subtype of suppressive TAMs and is linked to clinical outcome. An anti-MARCO monoclonal antibody was developed, which induces anti-tumor activity in breast and colon carcinoma, as well as in melanoma models through reprogramming TAM populations to a pro-inflammatory phenotype and increasing tumor immunogenicity. This anti-tumor activity is dependent on the inhibitory Fc-receptor, FcγRIIB, and also enhances the efficacy of checkpoint therapy. These results demonstrate that immunotherapies using antibodies designed to modify myeloid cells of the TME represent a promising mode of cancer treatment.
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Anticuerpos Antineoplásicos/farmacología , Progresión de la Enfermedad , Macrófagos/metabolismo , Neoplasias/patología , Animales , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Polaridad Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Citocinas/farmacología , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Humanos , Terapia de Inmunosupresión , Inmunoterapia , Melanoma/inmunología , Melanoma/patología , Melanoma/terapia , Ratones , Metástasis de la Neoplasia , Neoplasias/inmunología , Neoplasias/terapia , Receptores de IgG/metabolismo , Receptores Inmunológicos/metabolismo , Células del Estroma/patología , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunologíaRESUMEN
Breast cancer progression toward metastatic disease is linked to re-activation of epithelial-mesenchymal transition (EMT), a latent developmental process. Breast cancer cells undergoing EMT lose epithelial characteristics and gain the capacity to invade the surrounding tissue and migrate away from the primary tumor. However, less is known about the possible role of EMT in providing cancer cells with properties that allow them to traffic to distant sites. Given the fact that pro-metastatic cancer cells share a unique capacity with immune cells to traffic in-and-out of blood and lymphatic vessels we hypothesized that tumor cells undergoing EMT may acquire properties of immune cells. To study this, we performed gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an EMT program after long-term treatment with TGF-ß1 for 2 weeks. As expected, EMT cells acquired traits of mesenchymal cell differentiation and migration. However, in addition, we found another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER-/PR-) characteristics. The results identify an EMT-induced monocyte/macrophage gene cluster, which may play a role in breast cancer cell dissemination and metastasis.
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Myofibroblast accumulation, subepithelial fibrosis, and vascular remodeling are complicating features of chronic asthma, but the mechanisms are not clear. Platelet-derived growth factors (PDGFs) regulate the fate and function of various mesenchymal cells and have been implicated as mediators of lung fibrosis. However, it is not known whether PDGF-BB signaling via PDGFRß, which is critical for the recruitment of pericytes to blood vessels, plays a role in airway remodeling in chronic asthma. In the present study, we used a selective PDGFRß inhibitor (CP-673451) to investigate the role of PDGFRß signaling in the development of airway remodeling and lung dysfunction in an established mouse model of house dust mite-induced chronic allergic asthma. Unexpectedly, we found that pharmacological inhibition of PDGFRß signaling in the context of chronic aeroallergen exposure led to exacerbated lung dysfunction and airway smooth muscle thickening. Further studies revealed that the inflammatory response to aeroallergen challenge in mice was associated with decreased PDGF-BB expression and the loss of pericytes from the airway microvasculature. In parallel, cells positive for pericyte markers accumulated in the subepithelial region of chronically inflamed airways. This process was exacerbated in animals treated with CP-673451. The results indicate that perturbed PDGF-BB/PDGFRß signaling and pericyte accumulation in the airway wall may contribute to airway remodeling in chronic allergic asthma.
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Remodelación de las Vías Aéreas (Respiratorias) , Asma/patología , Pericitos/fisiología , Resistencia de las Vías Respiratorias , Animales , Asma/fisiopatología , Becaplermina , Bencimidazoles/farmacología , Bronquios/inmunología , Bronquios/metabolismo , Bronquios/patología , Enfermedad Crónica , Modelos Animales de Enfermedad , Elasticidad , Femenino , Ratones Endogámicos C57BL , Músculo Liso/patología , Proteínas Proto-Oncogénicas c-sis/metabolismo , Quinolinas/farmacología , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismoRESUMEN
Vascular development of the central nervous system and blood-brain barrier (BBB) induction are closely linked processes. The role of factors that promote endothelial sprouting and vascular leak, such as vascular endothelial growth factor A, are well described, but the factors that suppress angiogenic sprouting and their impact on the BBB are poorly understood. Here, we show that integrin αVß8 activates angiosuppressive TGFß gradients in the brain, which inhibit endothelial cell sprouting. Loss of αVß8 in the brain or downstream TGFß1-TGFBR2-ALK5-Smad3 signaling in endothelial cells increases vascular sprouting, branching and proliferation, leading to vascular dysplasia and hemorrhage. Importantly, BBB function in Itgb8 mutants is intact during early stages of vascular dysgenesis before hemorrhage. By contrast, Pdgfb(ret/ret) mice, which exhibit severe BBB disruption and vascular leak due to pericyte deficiency, have comparatively normal vascular morphogenesis and do not exhibit brain hemorrhage. Our data therefore suggest that abnormal vascular sprouting and patterning, not BBB dysfunction, underlie developmental cerebral hemorrhage.
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Barrera Hematoencefálica/fisiología , Encéfalo/irrigación sanguínea , Hemorragia Cerebral/etiología , Neovascularización Patológica/complicaciones , Transducción de Señal/fisiología , Análisis de Varianza , Animales , Encéfalo/metabolismo , Recuento de Células , Células Endoteliales/fisiología , Inmunohistoquímica , Integrinas/metabolismo , Ratones , Microscopía Confocal , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
OBJECTIVES: Advanced ileocecal Crohn's disease (ICD) is characterized by strictures, inflammation in the enteric nervous system (myenteric plexitis), and a high frequency of NOD2 mutations. Recent findings implicate a role of NOD2 and another CD susceptibility gene, ATG16L1, in the host response against single-stranded RNA (ssRNA) viruses. However, the role of viruses in CD is unknown. We hypothesized that human enterovirus species B (HEV-B), which are ssRNA viruses with dual tropism both for the intestinal epithelium and the nervous system, could play a role in ICD. METHODS: We used immunohistochemistry and in situ hybridization to study the general presence of HEV-B and the presence of the two HEV-B subspecies, Coxsackie B virus (CBV) and Echovirus, in ileocecal resections from 9 children with advanced, stricturing ICD and 6 patients with volvulus, and in intestinal biopsies from 15 CD patients at the time of diagnosis. RESULTS: All patients with ICD had disease-associated polymorphisms in NOD2 or ATG16L1. Positive staining for HEV-B was detected both in the mucosa and in myenteric nerve ganglia in all ICD patients, but in none of the volvulus patients. Expression of the cellular receptor for CBV, CAR, was detected in nerve cell ganglia. CONCLUSIONS: The common presence of HEV-B in the mucosa and enteric nervous system of ICD patients in this small cohort is a novel finding that warrants further investigation to analyze whether HEV-B has a role in disease onset or progress. The presence of CAR in myenteric nerve cell ganglia provides a possible route of entry for CBV into the enteric nervous system.
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Therapy-induced resistance remains a significant hurdle to achieve long-lasting responses and cures in cancer patients. We investigated the long-term consequences of genetically impaired angiogenesis by engineering multiple tumor models deprived of endoglin, a co-receptor for TGF-ß in endothelial cells actively engaged in angiogenesis. Tumors from endoglin-deficient mice adapted to the weakened angiogenic response, and refractoriness to diminished endoglin signaling was accompanied by increased metastatic capability. Mechanistic studies in multiple mouse models of cancer revealed that deficiency for endoglin resulted in a tumor vasculature that displayed hallmarks of endothelial-to-mesenchymal transition, a process of previously unknown significance in cancer biology, but shown by us to be associated with a reduced capacity of the vasculature to avert tumor cell intra- and extravasation. Nevertheless, tumors deprived of endoglin exhibited a delayed onset of resistance to anti-VEGF (vascular endothelial growth factor) agents, illustrating the therapeutic utility of combinatorial targeting of multiple angiogenic pathways for the treatment of cancer.
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Endotelio Vascular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/fisiología , Tumores Neuroendocrinos/irrigación sanguínea , Neoplasias Pancreáticas/irrigación sanguínea , Animales , Células Cultivadas , Endoglina , Transición Epitelial-Mesenquimal , Femenino , Proteínas Activadoras de GTPasa/fisiología , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Neoplasias Hepáticas Experimentales/secundario , Ratones , Neovascularización Fisiológica , Neoplasias Pancreáticas/patología , Proteína 1 Relacionada con Twist/fisiología , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
Angiogenesis, the process by which new blood vessels arise from preexisting ones, is critical for embryonic development and is an integral part of many disease processes. Recent studies have provided detailed information on how angiogenic sprouts initiate, elongate, and branch, but less is known about how these processes cease. Here, we show that S1PR1, a receptor for the blood-borne bioactive lipid sphingosine-1-phosphate (S1P), is critical for inhibition of angiogenesis and acquisition of vascular stability. Loss of S1PR1 leads to increased endothelial cell sprouting and the formation of ectopic vessel branches. Conversely, S1PR1 signaling inhibits angiogenic sprouting and enhances cell-to-cell adhesion. This correlates with inhibition of vascular endothelial growth factor-A (VEGF-A)-induced signaling and stabilization of vascular endothelial (VE)-cadherin localization at endothelial junctions. Our data suggest that S1PR1 signaling acts as a vascular-intrinsic stabilization mechanism, protecting developing blood vessels against aberrant angiogenic responses.