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1.
J Neurosci ; 37(46): 11271-11284, 2017 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-29038237

RESUMEN

Engagement of integrins by the extracellular matrix initiates signaling cascades that drive a variety of cellular functions, including neuronal migration and axonal pathfinding in the brain. Multiple lines of evidence link the ITGB3 gene encoding the integrin ß3 subunit with the serotonin (5-HT) system, likely via its modulation of the 5-HT transporter (SERT). The ITGB3 coding polymorphism Leu33Pro (rs5918, PlA2) produces hyperactive αvß3 receptors that influence whole-blood 5-HT levels and may influence the risk for autism spectrum disorder (ASD). Using a phenome-wide scan of psychiatric diagnoses, we found significant, male-specific associations between the Pro33 allele and attention-deficit hyperactivity disorder and ASDs. Here, we used knock-in (KI) mice expressing an Itgb3 variant that phenocopies the human Pro33 variant to elucidate the consequences of constitutively enhanced αvß3 signaling to the 5-HT system in the brain. KI mice displayed deficits in multiple behaviors, including anxiety, repetitive, and social behaviors. Anatomical studies revealed a significant decrease in 5-HT synapses in the midbrain, accompanied by decreases in SERT activity and reduced localization of SERTs to integrin adhesion complexes in synapses of KI mice. Inhibition of focal adhesion kinase (FAK) rescued SERT function in synapses of KI mice, demonstrating that constitutive active FAK signaling downstream of the Pro32Pro33 integrin αvß3 suppresses SERT activity. Our studies identify a complex regulation of 5-HT homeostasis and behaviors by integrin αvß3, revealing an important role for integrins in modulating risk for neuropsychiatric disorders.SIGNIFICANCE STATEMENT The integrin ß3 Leu33Pro coding polymorphism has been associated with autism spectrum disorders (ASDs) within a subgroup of patients with elevated blood 5-HT levels, linking integrin ß3, 5-HT, and ASD risk. We capitalized on these interactions to demonstrate that the Pro33 coding variation in the murine integrin ß3 recapitulates the sex-dependent neurochemical and behavioral attributes of ASD. Using state-of-the-art techniques, we show that presynaptic 5-HT function is altered in these mice, and that the localization of 5-HT transporters to specific compartments within the synapse, disrupted by the integrin ß3 Pro33 mutation, is critical for appropriate reuptake of 5-HT. Our studies provide fundamental insight into the genetic network regulating 5-HT neurotransmission in the CNS that is also associated with ASD risk.


Asunto(s)
Encéfalo/fisiología , Mutación con Ganancia de Función/genética , Variación Genética/genética , Integrina beta3/genética , Prolina/genética , Serotonina/genética , Animales , Femenino , Técnicas de Sustitución del Gen/métodos , Humanos , Integrina beta3/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Prolina/metabolismo , Unión Proteica/fisiología , Serotonina/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo
2.
J Cell Sci ; 129(1): 80-94, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26585313

RESUMEN

In vertebrate epithelia, p120-catenin (hereafter referred to as p120; also known as CTNND1) mediates E-cadherin stability and suppression of RhoA. Genetic ablation of p120 in various epithelial tissues typically causes striking alterations in tissue function and morphology. Although these effects could very well involve p120's activity towards Rho, ascertaining the impact of this relationship has been complicated by the fact that p120 is also required for cell-cell adhesion. Here, we have molecularly uncoupled p120's cadherin-stabilizing and RhoA-suppressing activites. Unexpectedly, removing p120's Rho-suppressing activity dramatically disrupted the integrity of the apical surface, irrespective of E-cadherin stability. The physical defect was tracked to excessive actomyosin contractility along the vertical axis of lateral membranes. Thus, we suggest that p120's distinct activities towards E-cadherin and Rho are molecularly and functionally coupled and this, in turn, enables the maintenance of cell shape in the larger context of an epithelial monolayer. Importantly, local suppression of contractility by cadherin-bound p120 appears to go beyond regulating cell shape, as loss of this activity also leads to major defects in epithelial lumenogenesis.


Asunto(s)
Cateninas/metabolismo , Membrana Celular/metabolismo , Polaridad Celular , Células Epiteliales/citología , Secuencia de Aminoácidos , Animales , Cadherinas/metabolismo , Cateninas/química , Forma de la Célula , Perros , Células Epiteliales/metabolismo , Células de Riñón Canino Madin Darby , Datos de Secuencia Molecular , Miosina Tipo IIA no Muscular/metabolismo , Fenotipo , Unión Proteica , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Catenina delta
3.
Dev Biol ; 383(1): 39-51, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-24021482

RESUMEN

Zebrafish gastrulation cell movements occur in the context of dynamic changes in extracellular matrix (ECM) organization and require the concerted action of planar cell polarity (PCP) proteins that regulate cell elongation and mediolateral alignment. Data obtained using Xenopus laevis gastrulae have shown that integrin-fibronectin interactions underlie the formation of polarized cell protrusions necessary for PCP and have implicated PCP proteins themselves as regulators of ECM. By contrast, the relationship between establishment of PCP and ECM assembly/remodeling during zebrafish gastrulation is unclear. We previously showed that zebrafish embryos carrying a null mutation in the four-pass transmembrane PCP protein vang-like 2 (vangl2) exhibit increased matrix metalloproteinase activity and decreased immunolabeling of fibronectin. These data implicated for the first time a core PCP protein in the regulation of pericellular proteolysis of ECM substrates and raised the question of whether other zebrafish PCP proteins also impact ECM organization. In Drosophila melanogaster, the cytoplasmic PCP protein Prickle binds Van Gogh and regulates its function. Here we report that similar to vangl2, loss of zebrafish prickle1a decreases fibronectin protein levels in gastrula embryos. We further show that Prickle1a physically binds Vangl2 and regulates both the subcellular distribution and total protein level of Vangl2. These data suggest that the ability of Prickle1a to impact fibronectin organization is at least partly due to effects on Vangl2. In contrast to loss of either Vangl2 or Prickle1a function, we find that glypican4 (a Wnt co-receptor) and frizzled7 mutant gastrula embryos with disrupted non-canonical Wnt signaling exhibit the opposite phenotype, namely increased fibronectin assembly. Our data show that glypican4 mutants do not have decreased proteolysis of ECM substrates, but instead have increased cell surface cadherin protein expression and increased intercellular adhesion. These data indicate that Wnt/Glypican4/Frizzled signaling regulates ECM assembly through effects on cadherin-mediated cell cohesion. Together, our results demonstrate that zebrafish Vangl2/Prickle1a and non-canonical Wnt/Frizzled signaling have opposing effects on ECM organization underlying PCP and gastrulation cell movements.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Polaridad Celular/fisiología , Matriz Extracelular/fisiología , Gastrulación/fisiología , Proteínas con Dominio LIM/metabolismo , Proteínas de la Membrana/metabolismo , Vía de Señalización Wnt/fisiología , Proteínas de Pez Cebra/metabolismo , Pez Cebra/embriología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Western Blotting , Técnicas de Silenciamiento del Gen , Glipicanos/metabolismo , Inmunoprecipitación , Proteínas con Dominio LIM/genética , Proteínas de la Membrana/genética , Microscopía Confocal , Microscopía Electrónica de Transmisión , Receptores de Superficie Celular/metabolismo , Proteínas de Pez Cebra/genética
4.
J Relig Health ; 53(3): 675-89, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23180008

RESUMEN

Excessive alcohol consumption increases the years of life lost to premature death and disability worldwide. Religion is a mitigating factor in alcohol consumption. A survey in the Dominican Republic showed increasing church attendance by middle and high school students (N = 3,478) was associated with a delay in age at first alcoholic drink, fewer students who had consumed alcohol in the past month (current drinkers), lower alcohol consumption levels, fewer episodes of inebriation, and less heavy episodic alcohol consumption (all P < 0.0001). The results suggested that it may be useful to conceive of church-attending youth as a subset of the adolescent social network when planning primary alcohol prevention programs for young people.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Consumo de Bebidas Alcohólicas/psicología , Países en Desarrollo , Religión y Psicología , Identificación Social , Estudiantes/psicología , Adolescente , Consumo de Bebidas Alcohólicas/prevención & control , Alcoholismo/epidemiología , Alcoholismo/prevención & control , Alcoholismo/psicología , Consumo Excesivo de Bebidas Alcohólicas/epidemiología , Consumo Excesivo de Bebidas Alcohólicas/prevención & control , Consumo Excesivo de Bebidas Alcohólicas/psicología , Niño , Estudios Transversales , República Dominicana , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Apoyo Social
5.
Breast Cancer Res ; 14(2): R52, 2012 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-22429491

RESUMEN

INTRODUCTION: In this pre-clinical in vitro study conducted in estrogen receptor positive (ER+) breast cancer cells, we have characterized the effects of insulin-like growth factor I (IGF-1) on the cytostatic and cytotoxic action of antiestrogen treatment when used as a single agent or in combination with the antiprogestin mifepristone (MIF). Our goal was to identify new molecular targets to improve the efficacy of hormonal therapy in breast cancer patients that have a poor response to hormonal therapy, in part, due to high circulating levels of unbound insulinIGF-1. METHODS: IGF-1-mediated effects on cytostasis and apoptotic cell death were determined with cell counts conducted in the presence and absence of trypan blue; enzyme-linked immunosorbent assays to determine the intracellular levels of cleaved cytokeratin 18, a marker of epithelial cancer cell apoptosis; and immunoblot analysis to determine the levels of cleaved poly-ADP ribose polymerase (PARP) and lamin A that result from caspase-dependent apoptosis. Cytotoxicity was further characterized by determination of the levels of reactive oxygen species (ROS) and the percent of mitochondrial membrane depolarization in cell populations treated with the different hormones in the presence and absence of IGF-1. Small molecule inhibitors of the dual-specificity protein kinase MEK1, MEK1 siRNA, Bim siRNA, and vectors overexpressing MEK1 wild type and mutant, dominant negative cDNA were used to identify key IGF-1 downstream prosurvival effectors. RESULTS: IGF-1, at physiologically relevant levels, blocked the cytotoxic action(s) of the antiestrogens 4-hydroxytamoxifen (4-OHT) and tamoxifen (TAM) when used as single agents or in combination with the antiprogestin MIF. The antiapoptotic action of IGF-1 was mediated primarily through the action of MEK1. MEK1 expression reduced the levels of ROS and mitochondrial membrane depolarization induced by the hormonal treatments via a mechanism that involved the phosphorylation and proteasomal turnover of the proapoptotic BH3-only Bcl-2 family member Bim. Importantly, small-molecule inhibitors of MEK1 circumvented the prosurvival action of IGF-1 by restoring Bim to levels that more effectively mediated apoptosis in ER+ breast cancer cells. CONCLUSION: his study provides strong support for the use of MEK1 inhibitors in combination with hormonal therapy to effectively affect cytostasis and activate a Bim-dependent apoptotic pathway in ER+ breast cancer cells. We discuss that MEK1 blockade may be a particularly effective treatment for women with high circulating levels of IGF-1, which have been correlated to a poor prognosis.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Moduladores de los Receptores de Estrógeno/farmacología , Factor I del Crecimiento Similar a la Insulina/metabolismo , MAP Quinasa Quinasa 1/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteína 11 Similar a Bcl2 , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Inhibidores Enzimáticos/farmacología , Antagonistas de Estrógenos/farmacología , Femenino , Antagonistas de Hormonas/farmacología , Humanos , Factor I del Crecimiento Similar a la Insulina/farmacología , MAP Quinasa Quinasa 1/antagonistas & inhibidores , MAP Quinasa Quinasa 1/genética , Mifepristona/farmacología , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Receptores de Estrógenos/metabolismo , Tamoxifeno/análogos & derivados , Tamoxifeno/farmacología
7.
Front Neurosci ; 13: 70, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30787865

RESUMEN

Human studies first identified genetic and expression interactions between integrin ß3 and serotonin (5-HT) transporter (SERT) genes. This association has been further strengthened by our discovery that integrin ß3-containing receptors (αvß3) physically interact with, and thereby define, a subpopulation of SERTs that may represent the main target of selective serotonin reuptake inhibitors (SSRIs). In this study, we examine how integrin αvß3 function influences the behavioral response to the highly SSRI citalopram in the tail suspension test. Mice bearing a conditional deletion of the integrin ß3 gene in neurons, or those expressing a constitutively active αvß3 receptor, have decreased sensitivity to citalopram, when compared to wild-type littermates. To identify potential signaling pathways downstream of integrin αvß3 that could be altered in these mouse lines, and consequently influence citalopram response in vivo, we performed antibody array analyses of midbrain synaptosomes isolated from mice bearing genetically altered integrin ß3. We then pharmacologically targeted focal adhesion (FAK) and extracellular-signal-regulated (ERK) kinases and determined that FAK and ERK activity are critical for the actions of citalopram. Taken together, our studies have revealed a complex relationship between integrin αvß3 function, SERT-dependent 5-HT uptake, and the effective dose of citalopram in the TST, thus implicating a role for integrin signaling pathways in the behavioral response to SSRIs.

8.
Sci Signal ; 12(569)2019 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-30783011

RESUMEN

G protein-coupled receptors (GPCRs) that couple to Gi/o proteins modulate neurotransmission presynaptically by inhibiting exocytosis. Release of Gßγ subunits from activated G proteins decreases the activity of voltage-gated Ca2+ channels (VGCCs), decreasing excitability. A less understood Gßγ-mediated mechanism downstream of Ca2+ entry is the binding of Gßγ to SNARE complexes, which facilitate the fusion of vesicles with the cell plasma membrane in exocytosis. Here, we generated mice expressing a form of the SNARE protein SNAP25 with premature truncation of the C terminus and that were therefore partially deficient in this interaction. SNAP25Δ3 homozygote mice exhibited normal presynaptic inhibition by GABAB receptors, which inhibit VGCCs, but defective presynaptic inhibition by receptors that work directly on the SNARE complex, such as 5-hydroxytryptamine (serotonin) 5-HT1b receptors and adrenergic α2a receptors. Simultaneously stimulating receptors that act through both mechanisms showed synergistic inhibitory effects. SNAP25Δ3 homozygote mice had various behavioral phenotypes, including increased stress-induced hyperthermia, defective spatial learning, impaired gait, and supraspinal nociception. These data suggest that the inhibition of exocytosis by Gi/o-coupled GPCRs through the Gßγ-SNARE interaction is a crucial component of numerous physiological and behavioral processes.


Asunto(s)
Subunidades beta de la Proteína de Unión al GTP/metabolismo , Subunidades gamma de la Proteína de Unión al GTP/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteína 25 Asociada a Sinaptosomas/metabolismo , Animales , Calcio , Exocitosis/fisiología , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Ratones Noqueados , Inhibición Neural/fisiología , Fenotipo , Unión Proteica , Transmisión Sináptica/fisiología , Proteína 25 Asociada a Sinaptosomas/genética
10.
J Clin Invest ; 127(12): 4462-4476, 2017 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-29130932

RESUMEN

p120-Catenin (p120) functions as a tumor suppressor in intestinal cancer, but the mechanism is unclear. Here, using conditional p120 knockout in Apc-sensitized mouse models of intestinal cancer, we have identified p120 as an "obligatory" haploinsufficient tumor suppressor. Whereas monoallelic loss of p120 was associated with a significant increase in tumor multiplicity, loss of both alleles was never observed in tumors from these mice. Moreover, forced ablation of the second allele did not further enhance tumorigenesis, but instead induced synthetic lethality in combination with Apc loss of heterozygosity. In tumor-derived organoid cultures, elimination of both p120 alleles resulted in caspase-3-dependent apoptosis that was blocked by inhibition of Rho kinase (ROCK). With ROCK inhibition, however, p120-ablated organoids exhibited a branching phenotype and a substantial increase in cell proliferation. Access to data from Sleeping Beauty mutagenesis screens afforded an opportunity to directly assess the tumorigenic impact of p120 haploinsufficiency relative to other candidate drivers. Remarkably, p120 ranked third among the 919 drivers identified. Cofactors α-catenin and epithelial cadherin (E-cadherin) were also among the highest scoring candidates, indicating a mechanism at the level of the intact complex that may play an important role at very early stages of of intestinal tumorigenesis while simultaneously restricting outright loss via synthetic lethality.


Asunto(s)
Proteína de la Poliposis Adenomatosa del Colon , Cateninas , Haploinsuficiencia , Neoplasias Intestinales , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Animales , Cateninas/genética , Cateninas/metabolismo , Neoplasias Intestinales/genética , Neoplasias Intestinales/metabolismo , Neoplasias Intestinales/patología , Ratones , Ratones Noqueados , Quinasas Asociadas a rho/genética , Quinasas Asociadas a rho/metabolismo , Catenina delta
11.
Int J Radiat Oncol Biol Phys ; 55(4): 1051-65, 2003 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-12605985

RESUMEN

PURPOSE: To determine if clinically relevant doses of ionizing radiation are capable of inducing extrachromosomal DNA loss in transformed human cell lines. MATERIALS AND METHODS: The multidrug-resistant (MDR) human epidermoid KB-C1 cell line and the human neuroendocrine colon carcinoma line COLO320, which contain extrachromosomally amplified MDR1 drug resistance genes and MYCC oncogenes, were irradiated with 2 Gy fractions up to a total dose of 28 Gy. To track the fate of extrachromosomally amplified genes, cells surviving radiation therapy and unirradiated control cells were analyzed by fluorescent in situ hybridization of chromosomes using MDR1 and MYCC-specific cosmid DNA probes. In addition, total DNA and protein isolated from irradiated and control cells was subjected to Southern and Western blotting procedures, respectively, to determine amplified gene copy number and protein expression levels. Dose-response assays to follow loss of function of the MDR1 gene from KB-C1 cells were also performed. RESULTS: A significant reduction in extrachromosomal DNA, amplified gene copy number, and expression was detected in surviving cells after relatively low doses of radiation. Entrapment of extrachromosomal DNA into micronuclei was a consistent feature of irradiated cells. CONCLUSIONS: Clinically relevant doses of radiation can deplete extrachromosomal DNA in viable human malignant cells and alter their phenotype. Depletion of extrachromosomally amplified genes from tumor cells occurs via entrapment in radiation-induced micronuclei.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/análisis , Resistencia a Antineoplásicos/efectos de la radiación , Amplificación de Genes , Eliminación de Gen , Genes MDR/efectos de la radiación , Genes myc/efectos de la radiación , Proteínas Proto-Oncogénicas c-myc/análisis , Línea Celular Transformada/efectos de los fármacos , Línea Celular Transformada/efectos de la radiación , Fraccionamiento de la Dosis de Radiación , Relación Dosis-Respuesta en la Radiación , Resistencia a Antineoplásicos/genética , Citometría de Flujo , Genes MDR/efectos de los fármacos , Genes myc/efectos de los fármacos , Humanos , Pruebas de Micronúcleos , Tolerancia a Radiación/efectos de los fármacos , Tolerancia a Radiación/genética , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/efectos de la radiación , Ensayo de Tumor de Célula Madre
12.
PLoS One ; 9(6): e101007, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24971939

RESUMEN

BACKGROUND: People share medicines and problems can result from this behavior. Successful interventions to change sharing behavior will require understanding people's motives and purposes for sharing medicines. Better information about how medicines fit into the gifting and reciprocity system could be useful in designing interventions to modify medicine sharing behavior. However, it is uncertain how people situate medicines among other items that might be shared. This investigation is a descriptive study of how people sort medicines and other shareable items. METHODS AND FINDINGS: This study in the Dominican Republic examined how a convenience sample (31 people) sorted medicines and rated their shareability in relation to other common household items. We used non-metric multidimensional scaling to produce association maps in which the distances between items offer a visual representation of the collective opinion of the participants regarding the relationships among the items. In addition, from a pile sort constrained by four categories of whether sharing or loaning the item was acceptable (on a scale from not shareable to very shareable), we assessed the degree to which the participants rated the medicines as shareable compared to other items. Participants consistently grouped medicines together in all pile sort activities; yet, medicines were mixed with other items when rated by their candidacy to be shared. Compared to the other items, participants had more variability of opinion as to whether medicines should be shared. CONCLUSIONS: People think of medicines as a distinct group, suggesting that interventions might be designed to apply to medicines as a group. People's differing opinions as to whether it was appropriate to share medicines imply a degree of uncertainty or ambiguity that health promotion interventions might exploit to alter attitudes and behaviors. These findings have implications for the design of health promotion interventions to impact medicine sharing behavior.


Asunto(s)
Conducta Ceremonial , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/psicología , Donaciones , Artículos Domésticos , Adulto , República Dominicana , Femenino , Humanos , Masculino
13.
Mol Biol Cell ; 25(17): 2592-603, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-25009281

RESUMEN

p120-catenin (p120) modulates adherens junction (AJ) dynamics by controlling the stability of classical cadherins. Among all p120 isoforms, p120-3A and p120-1A are the most prevalent. Both stabilize cadherins, but p120-3A is preferred in epithelia, whereas p120-1A takes precedence in neurons, fibroblasts, and macrophages. During epithelial-to-mesenchymal transition, E- to N-cadherin switching coincides with p120-3A to -1A alternative splicing. These isoforms differ by a 101-amino acid "head domain" comprising the p120-1A N-terminus. Although its exact role is unknown, the head domain likely mediates developmental and cancer-associated events linked to p120-1A expression (e.g., motility, invasion, metastasis). Here we identified delta-interacting protein A (DIPA) as the first head domain-specific binding partner and candidate mediator of isoform 1A activity. DIPA colocalizes with AJs in a p120-1A- but not 3A-dependent manner. Moreover, all DIPA family members (Ccdc85a, Ccdc85b/DIPA, and Ccdc85c) interact reciprocally with p120 family members (p120, δ-catenin, p0071, and ARVCF), suggesting significant functional overlap. During zebrafish neural tube development, both knockdown and overexpression of DIPA phenocopy N-cadherin mutations, an effect bearing functional ties to a reported mouse hydrocephalus phenotype associated with Ccdc85c. These studies identify a novel, highly conserved interaction between two protein families that may participate either individually or collectively in N-cadherin-mediated development.


Asunto(s)
Cateninas/fisiología , Hidrocefalia/metabolismo , Uniones Adherentes/metabolismo , Secuencia de Aminoácidos , Animales , Cadherinas/metabolismo , Cateninas/química , Cateninas/genética , Cateninas/metabolismo , Línea Celular Tumoral , Secuencia Conservada , Perros , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Células de Riñón Canino Madin Darby , Datos de Secuencia Molecular , Defectos del Tubo Neural/genética , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína , Alineación de Secuencia , Pez Cebra/genética , Pez Cebra/metabolismo , Catenina delta
14.
Mol Biol Cell ; 23(1): 99-110, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22031287

RESUMEN

The dynamic functional linkage of cadherins with the underlying actin cytoskeleton is tightly regulated to achieve proper cell-cell adhesion. p120-catenin (p120) regulates both cadherin stability and actin dynamics, but the relationship between these two functions remains unclear. Using a novel proteomic approach called reversible cross-link immunoprecipitation, or ReCLIP, we previously identified a physical interaction between p120 and Rho-associated protein kinase 1 (ROCK1), a major effector of RhoA. In this paper, we show that a discrete fraction of cellular ROCK1 coimmunoprecipitates with p120 and precisely colocalizes to adherens junctions (AJs). Manipulation of AJs using a calcium-switch assay and cadherin-blocking antibodies indicates direct recruitment of ROCK1 to newly forming junctions. Importantly, we find that p120 links ROCK1 to the cadherin complex, as ROCK1 coimmunoprecipitates with wild-type but not p120-uncoupled E-cadherin. Moreover, depletion of ROCK1 using short-hairpin RNA results in dramatic mislocalization of the cadherin complex and junctional actin. These data are consistent with a model in which p120 dynamically regulates Rho-GTPase activity at the cadherin complex through transient interaction with several of its up- and downstream effectors, including ROCK1.


Asunto(s)
Cadherinas/metabolismo , Cateninas/metabolismo , Quinasas Asociadas a rho/metabolismo , Actinas/metabolismo , Línea Celular , Técnicas de Silenciamiento del Gen , Factores de Intercambio de Guanina Nucleótido/metabolismo , Humanos , Uniones Intercelulares/metabolismo , Microscopía Fluorescente , Complejos Multiproteicos/metabolismo , Unión Proteica , Mapeo de Interacción de Proteínas , Transporte de Proteínas , Interferencia de ARN , Proteínas Represoras/metabolismo , Quinasas Asociadas a rho/genética , Catenina delta
15.
PLoS One ; 7(4): e34320, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22485163

RESUMEN

Tight junctions (TJs) and adherens junctions (AJs) are key determinants of the structure and permeability of epithelial barriers. Although exocytic delivery to the cell surface is crucial for junctional assembly, little is known about the mechanisms controlling TJ and AJ exocytosis. This study was aimed at investigating whether a key mediator of exocytosis, soluble N-ethylmaleimide sensitive factor (NSF) attachment protein alpha (αSNAP), regulates epithelial junctions. αSNAP was enriched at apical junctions in SK-CO15 and T84 colonic epithelial cells and in normal human intestinal mucosa. siRNA-mediated knockdown of αSNAP inhibited AJ/TJ assembly and establishment of the paracellular barrier in SK-CO15 cells, which was accompanied by a significant down-regulation of p120-catenin and E-cadherin expression. A selective depletion of p120 catenin effectively disrupted AJ and TJ structure and compromised the epithelial barrier. However, overexpression of p120 catenin did not rescue the defects of junctional structure and permeability caused by αSNAP knockdown thereby suggesting the involvement of additional mechanisms. Such mechanisms did not depend on NSF functions or induction of cell death, but were associated with disruption of the Golgi complex and down-regulation of a Golgi-associated guanidine nucleotide exchange factor, GBF1. These findings suggest novel roles for αSNAP in promoting the formation of epithelial AJs and TJs by controlling Golgi-dependent expression and trafficking of junctional proteins.


Asunto(s)
Uniones Adherentes/metabolismo , Células Epiteliales/citología , Uniones Intercelulares/metabolismo , Proteínas Solubles de Unión al Factor Sensible a la N-Etilmaleimida/fisiología , Uniones Estrechas/metabolismo , Animales , Apoptosis , Cateninas/genética , Cateninas/metabolismo , Bovinos , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/metabolismo , Colon/citología , Regulación hacia Abajo , Retículo Endoplásmico/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/fisiología , Aparato de Golgi/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Factores de Intercambio de Guanina Nucleótido/fisiología , Humanos , Permeabilidad , Transporte de Proteínas , Proteínas Solubles de Unión al Factor Sensible a la N-Etilmaleimida/genética , Proteínas Solubles de Unión al Factor Sensible a la N-Etilmaleimida/metabolismo , beta Catenina/metabolismo , Catenina delta
17.
J Cell Biol ; 184(3): 437-50, 2009 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-19188496

RESUMEN

p120-catenin regulates epithelial cadherin stability and has been suggested to function as a tumor suppressor. In this study, we used anchorage-independent growth (AIG), a classical in vitro tumorigenicity assay, to examine the role of p120 in a different context, namely oncogene-mediated tumorigenesis. Surprisingly, p120 ablation by short hairpin RNA completely blocked AIG induced by both Rac1 and Src. This role for p120 was traced to its activity in suppression of the RhoA-ROCK pathway, which appears to be essential for AIG. Remarkably, the AIG block associated with p120 ablation was completely reversed by inhibition of the downstream RhoA effector ROCK. Harvey-Ras (H-Ras)-induced AIG was also dependent on suppression of the ROCK cascade but was p120 independent because its action on the pathway occurred downstream of p120. The data suggest that p120 modulates oncogenic signaling pathways important for AIG. Although H-Ras bypasses p120, a unifying theme for all three oncogenes is the requirement to suppress ROCK, which may act as a gatekeeper for the transition to anchorage independence.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Fenómenos Fisiológicos Celulares , Fosfoproteínas/metabolismo , Transducción de Señal/fisiología , Proteína de Unión al GTP rac1/metabolismo , Familia-src Quinasas/metabolismo , Factores Despolimerizantes de la Actina/genética , Factores Despolimerizantes de la Actina/metabolismo , Actinas/metabolismo , Uniones Adherentes/metabolismo , Animales , Cadherinas/genética , Cadherinas/metabolismo , Cateninas , Moléculas de Adhesión Celular/genética , Línea Celular , Perros , Activación Enzimática , Genes ras , Humanos , Quinasas Lim/genética , Quinasas Lim/metabolismo , Fosfoproteínas/genética , Interferencia de ARN , Proteína de Unión al GTP rac1/genética , Proteínas ras/genética , Proteínas ras/metabolismo , Quinasas Asociadas a rho/genética , Quinasas Asociadas a rho/metabolismo , Familia-src Quinasas/genética , Catenina delta
18.
Cell ; 127(5): 1027-39, 2006 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-17129786

RESUMEN

Integration of receptor tyrosine kinase, integrin, and cadherin activities is crucial for normal cell growth, motility, and adhesion. Here, we describe roles for p120-catenin (p120) and p190RhoGAP that coordinate crosstalk between these systems and regulate cadherin function. Surprisingly, PDGFR-induced actin remodeling in NIH3T3 cells is blocked in the absence of p120, and the cells are partially transformed via constitutive activation of Rho. We have traced the mechanism to unexpected codependent roles for p120 and p190RhoGAP in regulating Rac-dependent antagonism of Rho. Receptor-induced Rac activity causes translocation of p190RhoGAP to adherens junctions (AJs), where it couples to the cadherin complex via interaction with p120. AJ formation is dependent on this p120-p190RhoGAP interaction and fails altogether if either of these proteins are compromised. We propose that Rac activation links diverse signaling systems to AJ assembly by controlling transient p190RhoGAP interactions with p120 and localized inhibition of Rho.


Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Fosfoproteínas/metabolismo , Proteínas Represoras/metabolismo , Proteínas de Unión al GTP rac/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Actinas/metabolismo , Uniones Adherentes/metabolismo , Animales , Cateninas , Adhesión Celular , Moléculas de Adhesión Celular/deficiencia , Línea Celular Transformada , Proliferación Celular , Extensiones de la Superficie Celular/metabolismo , Medio de Cultivo Libre de Suero , Fibroblastos/citología , Fibronectinas/metabolismo , Integrinas/metabolismo , Ratones , Modelos Biológicos , Células 3T3 NIH , Fosfoproteínas/deficiencia , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismo , Fibras de Estrés/metabolismo , Proteínas de Unión al GTP rac/antagonistas & inhibidores , Proteínas de Unión al GTP rho/antagonistas & inhibidores , Catenina delta
19.
Rev Panam Salud Publica ; 15(3): 185-93, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15096291

RESUMEN

OBJECTIVE: To assess the impact of health promotion programs and microcredit programs on three communities in the Dominican Republic. One community had only the health promotion program, one community had only the microcredit program, and one community had both a health promotion program and a microcredit program. This pilot project examined the hypothesis that the largest changes in 11 health indicators that were studied would be in the community with both a health promotion program and a microcredit program, that there would be intermediate changes in the community with only a health promotion program, and that the smallest changes would be in the community with only a microcredit program. METHODS: The health promotion programs used community volunteers to address two major concerns: (1) the prevalent causes of mortality among children under 5 years of age and (2) women's health (specifically breast and cervical cancer screening). The microcredit program made small loans to individuals to start or expand small businesses. Outcome measures were based on comparisons for 11 health indicators from baseline community surveys (27 households surveyed in each of the three communities, done in December 2000 and January 2001) and from follow-up surveys (also 27 households surveyed in each of the three communities, in June and July 2002, after the health promotion program had been operating for about 13 months). Households were randomly chosen during both the baseline and follow-up surveys, without regard to their involvement in the microcredit or health promotion programs. RESULTS: The health indicators improved in all three communities. However, the degree of change was different among the communities (P < 0.001). The community with parallel microcredit and health promotion programs had the largest changes for 10 of the 11 health indicators. CONCLUSIONS: Multisector development is known to be important on a macroeconomic scale. The results of this pilot project support the view that multisector development is also important on a microeconomic level, given that the parallel microcredit and health promotion programs resulted in greater change in the measured health indicators than either program alone. As far as we authors know, this is the first published study to quantify changes in health indicators related to parallel health promotion and microcredit programs as compared to control communities with only a health promotion program or a microcredit program.


Asunto(s)
Promoción de la Salud , Indicadores de Salud , Renta , República Dominicana , Humanos , Proyectos Piloto , Evaluación de Programas y Proyectos de Salud
20.
Rev. panam. salud pública ; 15(3): 185-193, Mar. 2004. tab
Artículo en Inglés | LILACS | ID: lil-363964

RESUMEN

OBJETIVO: Evaluar el impacto de programas de promoción de la salud y de microcréditos en tres comunidades de la República Dominicana. Una comunidad tenía solo un programa de promoción de la salud, otra contaba solo con un programa de microcréditos y una tercera comunidad contaba con ambos programas. Este proyecto piloto evaluó varias hipótesis: que los mayores cambios en los 11 indicadores de salud estudiados se verificarían en la comunidad que contaba tanto con un programa de promoción de la salud como con un programa de microcréditos; que habría cambios intermedios en la comunidad que solo tenía el programa de promoción de la salud, y que los menores cambios tendrían lugar en la comunidad que contaba solo con el programa de microcréditos. MÉTODOS: Los programas de promoción de la salud pusieron a voluntarios de la comunidad a hablar con la población acerca de dos grandes problemas: 1) las causas de mortalidad entre niños menores de 5 años de edad y 2) la salud de las mujeres (específicamente, el tamizaje del cáncer de mama y cervicouterino). El programa de microcréditos facilitaba préstamos personales pequeños para establecer o ampliar pequeñas empresas. Se compararon los valores de 11 indicadores de salud registrados durante las encuestas iniciales (27 viviendas encuestadas en cada una de las tres comunidades) realizadas entre diciembre de 2000 y enero de 2001 y las encuestas de seguimiento (27 viviendas encuestadas en cada una de las tres comunidades) realizadas entre junio julio de 2002, después de que el programa de promoción de la salud había estado en marcha por alrededor de 13 meses. Tanto en las encuestas iniciales como en las de seguimiento, las viviendas se seleccionaron de forma aleatoria, independientemente de su relación con los programas de microcréditos o de promoción de la salud. RESULTADOS: Los indicadores de salud mejoraron en las tres comunidades, pero la magnitud de los cambios fue diferente en cada una (P < 0,001). La ...


Objective. To assess the impact of health promotion programs and microcredit programs on three communities in the Dominican Republic. One community had only the health promotion program, one community had only the microcredit program, and one community had both a health promotion program and a microcredit program. This pilot project examined the hypothesis that the largest changes in 11 health indicators that were studied would be in the community with both a health promotion program and a microcredit program, that there would be intermediate changes in the community with only a health promotion program, and that the smallest changes would be in the community with only a microcredit program. Methods. The health promotion programs used community volunteers to address two major concerns: (1) the prevalent causes of mortality among children under 5 years of age and (2) women's health (specifically breast and cervical cancer screening). The microcredit program made small loans to individuals to start or expand small businesses. Outcome measures were based on comparisons for 11 health indicators from baseline community surveys (27 households surveyed in each of the three communities, done in December 2000 and January 2001) and from follow-up surveys (also 27 households surveyed in each of the three communities, in June and July 2002, after the health promotion program had been operating for about 13 months). Households were randomly chosen during both the baseline and follow-up surveys, without regard to their involvement in the microcredit or health promotion programs. Results. The health indicators improved in all three communities. However, the degree of change was different among the communities (P < 0.001). The community with parallel microcredit and health promotion programs had the largest changes for 10 of the 11 health indicators. Conclusions. Multisector development is known to be important on a macroeconomic scale. The results of this pilot project support the view that multisector development is also important on a microeconomic level, given that the parallel microcredit and health promotion programs resulted in greater change in the measured health indicators than either program alone. As far as we authors know, this is the first published study to quantify changes in health indicators related to parallel health promotion and microcredit programs as compared to control communities with only a health promotion program or a microcredit program


Asunto(s)
Humanos , Promoción de la Salud , Indicadores de Salud , Renta , República Dominicana , Proyectos Piloto , Evaluación de Programas y Proyectos de Salud
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