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1.
Pediatr Qual Saf ; 6(4): e432, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34345748

RESUMO

INTRODUCTION: Health systems spend $1.5 billion annually reporting data on quality, but efficacy and utility for benchmarking are limited due, in part, to limitations of data sources. Our objective was to implement and evaluate measures of pediatric quality for three conditions using electronic health record (EHR)-derived data. METHODS: PCORnet networks standardized EHR-derived data to a common data model. In 13 health systems from 2 networks for 2015, we implemented the National Quality Forum measures: % children with sickle cell anemia who received a transcranial Doppler; % children on antipsychotics who had metabolic screening; and % pediatric acute otitis media with amoxicillin prescribed. Manual chart review assessed measure accuracy. RESULTS: Only 39% (N = 2,923) of 7,278 children on antipsychotics received metabolic screening (range: 20%-54%). If the measure indicated screening was performed, the chart agreed 88% of the time [95% confidence interval (CI): 81%-94%]; if it indicated screening was not done, the chart agreed 86% (95% CI: 78%-93%). Only 69% (N = 793) of 1,144 children received transcranial Doppler screening (range across sites: 49%-88%). If the measure indicated screening was performed, the chart agreed 98% of the time (95% CI: 94%-100%); if it indicated screening was not performed, the chart agreed 89% (95% CI: 82%-95%). For acute otitis media, chart review identified many qualifying cases missed by the National Quality Forum measure, which excluded a common diagnostic code. CONCLUSIONS: Measures of healthcare quality developed using EHR-derived data were valid and identified wide variation among network sites. This data can facilitate the identification and spread of best practices.

2.
Am J Med Qual ; 35(2): 177-185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31115254

RESUMO

Measures of health care quality are produced from a variety of data sources, but often, physicians do not believe these measures reflect the quality of provided care. The aim was to assess the value to health system leaders (HSLs) and parents of benchmarking on health care quality measures using data mined from the electronic health record (EHR). Using in-context interviews with HSLs and parents, the authors investigated what new decisions and actions benchmarking using data mined from the EHR may enable and how benchmarking information should be presented to be most informative. Results demonstrate that although parents may have little experience using data on health care quality for decision making, they affirmed its potential value. HSLs expressed the need for high-confidence, validated metrics. They also perceived barriers to achieving meaningful metrics but recognized that mining data directly from the EHR could overcome those barriers. Parents and HSLs need high-confidence health care quality data to support decision making.


Assuntos
Registros Eletrônicos de Saúde , Administradores de Instituições de Saúde , Pais , Pediatria , Indicadores de Qualidade em Assistência à Saúde , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pesquisa Qualitativa , Qualidade da Assistência à Saúde
3.
Matern Child Health J ; 20(4): 843-53, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26694043

RESUMO

OBJECTIVE: Adverse childhood experiences (ACEs) are associated with myriad health conditions and risk behaviors in both adolescents and adults. In this study we examine the association between ACEs and specific physical, mental, and developmental conditions, as well as their comorbidity, in a nationally representative sample of children 0-17 years. METHODS: Data from the 2011-2012 National Survey for Child Health (NSCH) were used. A total of 95,677 random-digit-dial interviews with parents of children 0-17 years were conducted across all 50 states and the District of Columbia. Outcomes included singular condition domains (physical, mental, and developmental) as well as combinations of condition domains (e.g., physical plus mental, mental plus developmental, etc.). RESULTS: Twenty-three percent of parents reported that their child experienced 1 ACE; 9.2 % experienced 2 ACEs, and 10.3 % experienced three or more. Across all three condition domains and combinations of domains, children who experienced at least one ACE were more likely than children who experienced 0 ACEs to have at least one condition. Additionally, greater ACEs was associated with increased likelihood of at least one condition in each domain and in multiple domains. CONCLUSIONS: for practice These findings support the extension of existing family environment screening tools in pediatric practices as well as the establishment of a system for monitoring ACEs in families with multiple or complex conditions.


Assuntos
Maus-Tratos Infantis/estatística & dados numéricos , Filho de Pais com Deficiência/estatística & dados numéricos , Deficiências do Desenvolvimento/epidemiologia , Crianças com Deficiência/psicologia , Acontecimentos que Mudam a Vida , Saúde Mental/estatística & dados numéricos , Adolescente , Criança , Maus-Tratos Infantis/psicologia , Filho de Pais com Deficiência/psicologia , Pré-Escolar , Comorbidade , District of Columbia/epidemiologia , Divórcio/estatística & dados numéricos , Violência Doméstica/estatística & dados numéricos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Vigilância da População , Fatores de Risco
4.
J Health Care Poor Underserved ; 26(3): 686-700, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26320905

RESUMO

OBJECTIVE: A recent policy statement from the American Academy of Pediatrics outlines the central role of pediatricians in screening for and addressing precipitants of toxic stress (e.g., adverse experiences). Despite these recommendations, it is unknown whether pediatricians are in fact screening for these precipitants. METHODS: A sample of 210 pediatricians serving low-income children completed a survey regarding their responses to adverse childhood experiences (ACEs). Participants were asked to estimate the prevalence of ACEs in their practice, their current practices, and recommendations for screening. RESULTS: For nearly all ACEs, pediatricians' estimates of the prevalence in their practice were lower than state-reported prevalence. For many ACEs, the number of pediatricians who support the need for recommended screening was far higher than the number who reported actually screening. CONCLUSIONS: Our findings suggest clinicians serving primarily low-income families recommend screening but may underestimate the prevalence of ACEs in their practice and may not be equipped to screen or address these matters consistently.


Assuntos
Atitude do Pessoal de Saúde , Programas de Rastreamento/estatística & dados numéricos , Pediatras/psicologia , Médicos de Atenção Primária/psicologia , Vigilância da População , Pobreza , Estresse Psicológico/epidemiologia , Adolescente , Criança , Feminino , Florida/epidemiologia , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Masculino , Pediatras/estatística & dados numéricos , Médicos de Atenção Primária/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Prevalência
5.
Community Dent Oral Epidemiol ; 43(3): 193-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25413439

RESUMO

OBJECTIVE: This study seeks to explore the how specific toxic stressors, specifically adverse childhood experiences (ACEs), and their frequencies may be associated with tooth condition and the presence of caries. METHODS: Data from the 2011-12 National Survey for Child Health (NSCH), a nationally representative survey of child health, were used in this study. Pediatric dental health was measured using parent report of two characteristics: condition of teeth and having a toothache, decayed teeth, and/or unfilled cavities in the past 12 months. ACEs were measured by asking about a child's exposure to the divorce of a parent, parental incarceration, domestic violence, neighborhood violence, drug and alcohol abuse, mental illness, and financial hardship. Analyses were adjusted by sociodemographic characteristics, healthcare access and utilization, and comorbid chronic conditions. RESULTS: The presence of even one ACE in a child's life increased the likelihood of having poor dental health. Additionally, having multiple ACEs had a cumulative negative effect on the condition of their teeth and the presence of dental caries (Odds Ratios 1.61-2.55). Adjusted models show that racial and socioeconomic factors still play a significant role in dental health. CONCLUSIONS: In addition to the known disparities in dental caries, this study demonstrates that there is significant association between childhood psychosocial issues and dental health. Preventive dental care should be considered incorporating the screening of multiple biological stressors, including ACEs, in routine dental visits as a means of identifying and reducing dental health inequities.


Assuntos
Cárie Dentária/epidemiologia , Acontecimentos que Mudam a Vida , Doenças Dentárias/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Inquéritos Epidemiológicos , Humanos , Lactente , Masculino , Análise Multivariada , Estresse Psicológico/complicações , Estresse Psicológico/epidemiologia , Odontalgia/epidemiologia , Estados Unidos/epidemiologia
6.
Exp Cell Res ; 319(8): 1124-35, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23454549

RESUMO

In polarized, migrating cells, stress fibers are a highly dynamic network of contractile acto-myosin structures composed of bundles of actin filaments held together by actin cross-linking proteins such as α-actinins. As such, α-actinins influence actin cytoskeleton organization and dynamics and focal adhesion maturation. In response to environmental signals, α-actinins are tyrosine phosphorylated and this affects their binding to actin stress fibers; however, the cellular role of α-actinin tyrosine phosphorylation remains largely unknown. We found that non-muscle α-actinin1/4 are critical for the establishment of dorsal stress fibers and maintenance of transverse arc stress fibers. Analysis of cells genetically depleted of α-actinin1 and 4 reveals two distinct modes for focal adhesion maturation. An α-actinin1 or 4 dependent mode that uses dorsal stress fiber precursors as a template for establishing focal adhesions and their maturation, and an α-actinin-independent manner that uses transverse arc precursors to establish focal adhesions at both ends. Focal adhesions formed in the absence of α-actinins are delayed in their maturation, exhibit altered morphology, have decreased amounts of Zyxin and VASP, and reduced adhesiveness to extracellular matrix. Further rescue experiments demonstrate that the tyrosine phosphorylation of α-actinin1 at Y12 and α-actinin4 at Y265 is critical for dorsal stress fiber establishment, transverse arc maintenance and focal adhesion maturation.


Assuntos
Actinina/metabolismo , Adesões Focais/fisiologia , Proteínas Tirosina Quinases/metabolismo , Fibras de Estresse/metabolismo , Fibras de Estresse/fisiologia , Actinina/genética , Actinina/fisiologia , Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Quinase 1 de Adesão Focal/metabolismo , Adesões Focais/química , Adesões Focais/genética , Adesões Focais/metabolismo , Células HEK293 , Humanos , Proteínas dos Microfilamentos/metabolismo , Paxilina/metabolismo , Fosfoproteínas/metabolismo , Fosforilação/genética , Fosforilação/fisiologia , Proteínas Tirosina Quinases/fisiologia , Tirosina/genética , Tirosina/metabolismo , Zixina/metabolismo
7.
J Cell Biol ; 198(4): 657-76, 2012 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-22908313

RESUMO

Mena is an Ena/VASP family actin regulator with roles in cell migration, chemotaxis, cell-cell adhesion, tumor cell invasion, and metastasis. Although enriched in focal adhesions, Mena has no established function within these structures. We find that Mena forms an adhesion-regulated complex with α5ß1 integrin, a fibronectin receptor involved in cell adhesion, motility, fibronectin fibrillogenesis, signaling, and growth factor receptor trafficking. Mena bound directly to the carboxy-terminal portion of the α5 cytoplasmic tail via a 91-residue region containing 13 five-residue "LERER" repeats. In fibroblasts, the Mena-α5 complex was required for "outside-in" α5ß1 functions, including normal phosphorylation of FAK and paxillin and formation of fibrillar adhesions. It also supported fibrillogenesis and cell spreading and controlled cell migration speed. Thus, fibroblasts require Mena for multiple α5ß1-dependent processes involving bidirectional interactions between the extracellular matrix and cytoplasmic focal adhesion proteins.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Adesões Focais/fisiologia , Integrina alfa5/metabolismo , Integrina alfa5beta1/metabolismo , Transdução de Sinais/fisiologia , Animais , Proteínas do Citoesqueleto/genética , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/enzimologia , Fibroblastos/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Humanos , Camundongos , Camundongos Mutantes , Proteínas dos Microfilamentos , Células NIH 3T3 , Gravidez , Transporte Proteico/fisiologia , Ratos
8.
Proc Natl Acad Sci U S A ; 109(34): 13515-20, 2012 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-22869695

RESUMO

Entry of tumor cells into the blood stream is a critical step in cancer metastasis. Although significant progress has been made in visualizing tumor cell motility in vivo, the underlying mechanism of cancer cell intravasation remains largely unknown. We developed a microfluidic-based assay to recreate the tumor-vascular interface in three-dimensions, allowing for high resolution, real-time imaging, and precise quantification of endothelial barrier function. Studies are aimed at testing the hypothesis that carcinoma cell intravasation is regulated by biochemical factors from the interacting cells and cellular interactions with macrophages. We developed a method to measure spatially resolved endothelial permeability and show that signaling with macrophages via secretion of tumor necrosis factor alpha results in endothelial barrier impairment. Under these conditions intravasation rates were increased as validated with live imaging. To further investigate tumor-endothelial (TC-EC) signaling, we used highly invasive fibrosarcoma cells and quantified tumor cell migration dynamics and TC-EC interactions under control and perturbed (with tumor necrosis factor alpha) barrier conditions. We found that endothelial barrier impairment was associated with a higher number and faster dynamics of TC-EC interactions, in agreement with our carcinoma intravasation results. Taken together our results provide evidence that the endothelium poses a barrier to tumor cell intravasation that can be regulated by factors present in the tumor microenvironment.


Assuntos
Movimento Celular , Células Endoteliais/citologia , Microfluídica/métodos , Neoplasias/patologia , Comunicação Celular/fisiologia , Linhagem Celular Tumoral , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato , Imageamento Tridimensional , Macrófagos/citologia , Metástase Neoplásica , Neoplasias/irrigação sanguínea , Permeabilidade , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
9.
J Cell Biol ; 197(6): 721-9, 2012 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-22665521

RESUMO

Growth factor-induced migration is a critical step in the dissemination and metastasis of solid tumors. Although differences in properties characterizing cell migration on two-dimensional (2D) substrata versus within three-dimensional (3D) matrices have been noted for particular growth factor stimuli, the 2D approach remains in more common use as an efficient surrogate, especially for high-throughput experiments. We therefore were motivated to investigate which migration properties measured in various 2D assays might be reflective of 3D migratory behavioral responses. We used human triple-negative breast cancer lines stimulated by a panel of receptor tyrosine kinase ligands relevant to mammary carcinoma progression. Whereas 2D migration properties did not correlate well with 3D behavior across multiple growth factors, we found that increased membrane protrusion elicited by growth factor stimulation did relate robustly to enhanced 3D migration properties of the MDA-MB-231 and MDA-MB-157 lines. Interestingly, we observed this to be a more reliable relationship than cognate receptor expression or activation levels across these and two additional mammary tumor lines.


Assuntos
Neoplasias da Mama/patologia , Movimento Celular , Colágeno/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias/metabolismo , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Ligantes , Neoplasias/patologia , Receptores Proteína Tirosina Quinases/metabolismo
10.
Front Plant Sci ; 3: 69, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22639659

RESUMO

myo-Inositol is a precursor for cell wall components, is used as a backbone of myo-inositol trisphosphate (Ins(1,4,5)P(3)) and phosphatidylinositol phosphate signaling molecules, and is debated about whether it is also a precursor in an alternate ascorbic acid synthesis pathway. Plants control inositol homeostasis by regulation of key enzymes involved in myo-inositol synthesis and catabolism. Recent transcriptional profiling data indicate up-regulation of the myo-inositol oxygenase (MIOX) genes under conditions in which energy or nutrients are limited. To test whether the MIOX genes are required for responses to low energy, we first examined MIOX2 and MIOX4 gene expression regulation by energy/nutrient conditions. We found that both MIOX2 and MIOX4 expression are suppressed by exogenous glucose addition in the shoot, but not in the root. Both genes were abundantly expressed during low energy/nutrient conditions. Loss-of-function mutants in MIOX genes contain alterations in myo-inositol levels and growth changes in the root. Miox2 mutants can be complemented with a MIOX2:green fluorescent protein fusion. Further we show here that MIOX2 is a cytoplasmic protein, while MIOX4 is present mostly in the cytoplasm, but also occasionally in the nucleus. Together, these data suggest that MIOX catabolism in the shoot may influence root growth responses during low energy/nutrient conditions.

11.
Curr Opin Cell Biol ; 24(2): 284-91, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22284347

RESUMO

Chemotaxis of tumor cells in response to a gradient of extracellular ligand is an important step in cancer metastasis. The heterogeneity of chemotactic responses in cancer has not been widely addressed by experimental or mathematical modeling techniques. However, recent advancements in chemoattractant presentation, fluorescent-based signaling probes, and phenotypic analysis paradigms provide rich sources for building data-driven relational models that describe tumor cell chemotaxis in response to a wide variety of stimuli. Here we present gradient sensing, and the resulting chemotactic behavior, in a 'cue-signal-response' framework and suggest methods for utilizing recently reported experimental methods in data-driven modeling ventures.


Assuntos
Quimiotaxia , Modelos Biológicos , Neoplasias/patologia , Transdução de Sinais , Comunicação Celular , Fatores Quimiotáticos/metabolismo , Humanos , Ligantes
12.
Mol Cell Proteomics ; 10(11): M111.008433, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21832255

RESUMO

Epithelial-mesenchymal transition (EMT), whether in developmental morphogenesis or malignant transformation, prominently involves modified cell motility behavior. Although major advances have transpired in understanding the molecular pathways regulating the process of EMT induction per se by certain environmental stimuli, an important outstanding question is how the activities of signaling pathways governing motility yield the diverse movement behaviors characteristic of pre-induction versus postinduction states across a broad landscape of growth factor contexts. For the particular case of EMT induction in human mammary cells by ectopic expression of the transcription factor Twist, we found the migration responses to a panel of growth factors (EGF, HRG, IGF, HGF) dramatically disparate between confluent pre-Twist epithelial cells and sparsely distributed post-Twist mesenchymal cells-but that a computational model quantitatively integrating multiple key signaling node activities could nonetheless account for this full range of behavior. Moreover, motility in both conditions was successfully predicted a priori for an additional growth factor (PDGF) treatment. Although this signaling network state model could comprehend motility behavior globally, modulation of the network interactions underlying the altered pathway activities was identified by ascertaining differences in quantitative topological influences among the nodes between the two conditions.


Assuntos
Mama/citologia , Movimento Celular , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Proteínas Nucleares/metabolismo , Transdução de Sinais , Proteína 1 Relacionada a Twist/metabolismo , Linhagem Celular , Simulação por Computador , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Transição Epitelial-Mesenquimal , Receptores ErbB/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Análise dos Mínimos Quadrados , Modelos Biológicos , Análise Multivariada , Fenótipo , Fosforilação , Mapas de Interação de Proteínas
13.
J Cell Sci ; 124(Pt 13): 2120-31, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21670198

RESUMO

We have shown previously that distinct Mena isoforms are expressed in invasive and migratory tumor cells in vivo and that the invasion isoform (Mena(INV)) potentiates carcinoma cell metastasis in murine models of breast cancer. However, the specific step of metastatic progression affected by this isoform and the effects on metastasis of the Mena11a isoform, expressed in primary tumor cells, are largely unknown. Here, we provide evidence that elevated Mena(INV) increases coordinated streaming motility, and enhances transendothelial migration and intravasation of tumor cells. We demonstrate that promotion of these early stages of metastasis by Mena(INV) is dependent on a macrophage-tumor cell paracrine loop. Our studies also show that increased Mena11a expression correlates with decreased expression of colony-stimulating factor 1 and a dramatically decreased ability to participate in paracrine-mediated invasion and intravasation. Our results illustrate the importance of paracrine-mediated cell streaming and intravasation on tumor cell dissemination, and demonstrate that the relative abundance of Mena(INV) and Mena11a helps to regulate these key stages of metastatic progression in breast cancer cells.


Assuntos
Neoplasias da Mama/metabolismo , Movimento Celular , Proteínas do Citoesqueleto/metabolismo , Migração Transendotelial e Transepitelial , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Fator Estimulador de Colônias de Macrófagos/biossíntese , Macrófagos/metabolismo , Camundongos , Camundongos SCID , Proteínas dos Microfilamentos , Invasividade Neoplásica , Metástase Neoplásica , Isoformas de Proteínas/metabolismo , Ratos
14.
Ann Biomed Eng ; 38(8): 2775-90, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20358290

RESUMO

The ability to predict endothelial cell migration rates may aid in the design of biomaterials that endothelialize following implantation. However, the complexity of the signaling response to migration-promoting stimuli such as sphingosine 1-phosphate (S1P) makes such predictions quite challenging. A number of signaling pathways impact S1P-mediated cell migration, including the Akt and Src pathways, which both affect activation of the small GTPase Rac. Rac activation promotes the formation of lamellipodia, and thus should be intimately linked to cell migration rates. In immortalized endothelial cells, expression of proteins that inhibit Akt, Src, and Rac (PTEN, CSK, and beta2-chimaerin, respectively) was decreased using RNA interference, resulting in increases in the basal level of activation of Akt, Src, and Rac. Cells were scrape-wounded and stimulated with 1 microM S1P. The timecourse of Akt, Src, and Rac activation was followed over 2 h in the perturbed cells, while migration into the scrape wound was measured over 6 h. Rac activation at 120 min post-stimulation was highly correlated with the mean migration rate of cells, but only in cells stimulated with S1P. Using partial least squares regression, the migration rate of cells into the scrape wound was found to be highly correlated with the magnitude of the early Akt peak (e.g., 5-15 min post-stimulation). These results demonstrated that biochemical measurements might be useful in predicting rates of endothelial cell migration.


Assuntos
Movimento Celular/fisiologia , Lisofosfolipídeos/metabolismo , Esfingosina/análogos & derivados , Aorta/citologia , Técnicas de Cultura de Células , Células Cultivadas , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Cinética , Proteínas de Neoplasias , Óxido Nítrico Sintase Tipo III , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pseudópodes/metabolismo , Transdução de Sinais/fisiologia , Esfingosina/metabolismo , Fatores de Tempo
15.
Plant Cell ; 22(3): 888-903, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20215587

RESUMO

l-myo-inositol 1-phosphate synthase (MIPS; EC 5.5.1.4) catalyzes the rate-limiting step in the synthesis of myo-inositol, a critical compound in the cell. Plants contain multiple MIPS genes, which encode highly similar enzymes. We characterized the expression patterns of the three MIPS genes in Arabidopsis thaliana and found that MIPS1 is expressed in most cell types and developmental stages, while MIPS2 and MIPS3 are mainly restricted to vascular or related tissues. MIPS1, but not MIPS2 or MIPS3, is required for seed development, for physiological responses to salt and abscisic acid, and to suppress cell death. Specifically, a loss in MIPS1 resulted in smaller plants with curly leaves and spontaneous production of lesions. The mips1 mutants have lower myo-inositol, ascorbic acid, and phosphatidylinositol levels, while basal levels of inositol (1,4,5)P(3) are not altered in mips1 mutants. Furthermore, mips1 mutants exhibited elevated levels of ceramides, sphingolipid precursors associated with cell death, and were complemented by a MIPS1-green fluorescent protein (GFP) fusion construct. MIPS1-, MIPS2-, and MIPS3-GFP each localized to the cytoplasm. Thus, MIPS1 has a significant impact on myo-inositol levels that is critical for maintaining levels of ascorbic acid, phosphatidylinositol, and ceramides that regulate growth, development, and cell death.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Morte Celular , Inositol/biossíntese , Mio-Inositol-1-Fosfato Sintase/genética , Arabidopsis/enzimologia , Proteínas de Arabidopsis/genética , Ácido Ascórbico/metabolismo , Ceramidas/metabolismo , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Mutagênese Insercional , Mutação , Mio-Inositol-1-Fosfato Sintase/metabolismo , Fosfatidilinositóis/metabolismo
16.
Cancer Res ; 69(20): 8191-9, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19789336

RESUMO

More than 40% of colon cancers have a mutation in K-RAS or N-RAS, GTPases that operate as central hubs for multiple key signaling pathways within the cell. Utilizing an isogenic panel of colon carcinoma cells with K-RAS or N-RAS variations, we observed differences in tumor necrosis factor-alpha (TNFalpha)-induced apoptosis. When the dynamics of phosphorylated ERK response to TNFalpha were examined, K-RAS mutant cells showed lower activation whereas N-RAS mutant cells exhibited prolonged duration. These divergent trends were partially explained by differential induction of two ERK-modulatory circuits: negative feedback mediated by dual-specificity phosphatase 5 and positive feedback by autocrine transforming growth factor-alpha. Moreover, in the various RAS mutant colon carcinoma lines, the transforming growth factor-alpha autocrine loop differentially elicited a further downstream chemokine (CXCL1/CXCL8) autocrine loop, with the two loops having opposite effects on apoptosis. Although the apoptotic responses of the RAS mutant panel to TNFalpha treatment showed significant dependence on the respective phosphorylated ERK dynamics, successful prediction across the various cell lines required contextual information concerning additional pathways including IKK and p38. A quantitative computational model based on weighted linear combinations of these pathway activities successfully predicted not only the spectrum of cell death responses but also the corresponding chemokine production responses. Our findings indicate that diverse RAS mutations yield differential cell behavioral responses to inflammatory cytokine exposure by means of (a) differential effects on ERK activity via multiple feedback circuit mechanisms, and (b) differential effects on other key signaling pathways contextually modulating ERK-related dependence.


Assuntos
Apoptose/genética , Neoplasias do Colo/patologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Retroalimentação Fisiológica , Genes ras/genética , Mutação/genética , Proteínas Proto-Oncogênicas/genética , Fator de Necrose Tumoral alfa/farmacologia , Proteínas ras/genética , Apoptose/efeitos dos fármacos , Comunicação Autócrina , Western Blotting , Quimiocinas , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Biologia Computacional , Fosfatases de Especificidade Dupla/genética , Fosfatases de Especificidade Dupla/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imunofluorescência , Humanos , Proteínas Proto-Oncogênicas p21(ras) , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Células Tumorais Cultivadas
17.
J Biomed Mater Res A ; 88(1): 205-12, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18286622

RESUMO

Sphingosine 1-phosphate (S1P) promotes endothelial cell migration in vitro and may potentially impact the endothelialization of implanted biomaterials. However, the effects of S1P on endothelial cells (EC) in flowing blood could be negligible due to preactivation of signaling cascades. We previously developed biomaterials that release S1P and wished to determine through in vitro experiments the extent to which EC respond to S1P added to human platelet poor plasma. We found that addition of 200 nM S1P to platelet poor plasma significantly increased cell migration in two migration models. A lower concentration of S1P added to plasma (100 nM) did not increase endothelial cell migration rates, while the cell migration response was saturated above 200 nM S1P. Expression of the main S1P receptor in EC, S1P(1), was elevated in plasma compared to low serum medium, but addition of VEGF or fluid flow elicited a further increase in S1P(1) mRNA, consistent with the synergistic effects observed between S1P, VEGF, and fluid flow. Thus, sustained delivery of S1P from biomaterials might only enhance endothelial cell migration if the concentration of S1P at the surface of the material stimulated adjacent EC to the same extent as approximately 200 nM S1P added to plasma.


Assuntos
Circulação Sanguínea , Movimento Celular/efeitos dos fármacos , Células Endoteliais/fisiologia , Lisofosfolipídeos/farmacologia , Esfingosina/análogos & derivados , Materiais Biocompatíveis/uso terapêutico , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Modelos Biológicos , Receptores de Lisoesfingolipídeo/biossíntese , Esfingosina/farmacologia , Regulação para Cima/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/farmacologia
18.
J Immunol ; 181(4): 2544-55, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18684945

RESUMO

Tissue homing of activated T cells is typically mediated through their specific integrin and chemokine receptor repertoire. Activation of human primary CD4(+) T cells in the presence of CD46 cross-linking induces the development of a distinct immunomodulatory T cell population characterized by high IL-10/granzyme B production. How these regulatory T cells (Tregs) migrate/home to specific tissue sites is not understood. In this study, we determined the adhesion protein and chemokine receptor expression pattern on human CD3/CD46-activated peripheral blood CD4(+) T cells. CD3/CD46-activated, but not CD3/CD28-activated, T cells up-regulate the integrin alpha(4)beta(7). The interaction of alpha(4)beta(7) with its ligand mucosal addressin cell adhesion molecule 1 (MAdCAM-1) mediates homing or retention of T cells to the intestine. CD3/CD46-activated Tregs adhere to/roll on MAdCAM-1-expressing HeLa cells, similar to T cells isolated from the human lamina propria (LP). This interaction is inhibited by silencing MAdCAM-1 expression in HeLa cells or by the addition of blocking Abs to beta(7). CD46 activation of T cells also induced the expression of the surface-bound cytokine LIGHT and the chemokine receptor CCR9, both marker constitutively expressed by gut LP-resident T cells. In addition, we found that approximately 10% of the CD4(+) T lymphocytes isolated from the LP of patients undergoing bariatric surgery contain T cells that spontaneously secrete a cytokine pattern consistent with that from CD46-activated T cells. These data suggest that CD46-induced Tregs might play a role in intestinal immune homeostasis where they could dampen unwanted effector T cell responses through local IL-10/granzyme B production.


Assuntos
Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Ativação Linfocitária/imunologia , Proteína Cofatora de Membrana/fisiologia , Receptores de Quimiocinas/biossíntese , Receptores de Retorno de Linfócitos/biossíntese , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Moléculas de Adesão Celular , Células Cultivadas , Quimiotaxia de Leucócito/imunologia , Granzimas/biossíntese , Granzimas/fisiologia , Células HeLa , Humanos , Imunoglobulinas/biossíntese , Imunoglobulinas/fisiologia , Integrinas/biossíntese , Integrinas/fisiologia , Interleucina-10/biossíntese , Interleucina-10/metabolismo , Mucosa Intestinal/citologia , Mucoproteínas/biossíntese , Mucoproteínas/fisiologia , Receptores de Quimiocinas/genética , Receptores de Retorno de Linfócitos/fisiologia , Regulação para Cima/imunologia
19.
Biophys J ; 94(1): 273-85, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17827231

RESUMO

Sphingosine 1-phosphate (S1P) is a potent chemokinetic agent for endothelial cells that is released by activated platelets. We previously developed Arg-Gly-Asp (RGD)-containing polyethylene glycol biomaterials for the controlled delivery of S1P to promote endothelialization. Here, we studied the effects of cell adhesion strength on S1P-stimulated endothelial cell migration in the presence of arterial levels of fluid shear stress, since an upward shift in optimal cell adhesion strengths may be beneficial for promoting long-term cell adhesion to materials. Two RGD peptides with different integrin-binding specificities were added to the polyethylene glycol hydrogels. A linear RGD bound primarily to beta(3) integrins, whereas a cyclic RGD bound through both beta(1) and beta(3) integrins. We observed increased focal adhesion formation and better long-term adhesion in flow with endothelial cells on linear RGD peptide, versus cyclic RGD, even though initial adhesion strengths were higher for cells on cyclic RGD. Addition of 100 nM S1P increased cell speed and random motility coefficients on both RGD peptides, with the largest increases found on cyclic RGD. For both peptides, much of the increase in cell migration speed was found for smaller cells (<1522 microm(2) projected area), although the large increases on cyclic RGD were also due to medium-sized cells (2288-3519 microm(2)). Overall, a compromise between high cell migration rates and long-term adhesion will be important in the design of materials that endothelialize after implantation.


Assuntos
Técnicas de Cultura de Células/métodos , Células Endoteliais/citologia , Células Endoteliais/fisiologia , Lisofosfolipídeos/farmacologia , Oligopeptídeos/farmacologia , Polietilenoglicóis/química , Esfingosina/análogos & derivados , Adsorção , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Células Endoteliais/efeitos dos fármacos , Humanos , Lisofosfolipídeos/química , Oligopeptídeos/química , Esfingosina/química , Esfingosina/farmacologia
20.
Biomacromolecules ; 7(4): 1335-43, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16602758

RESUMO

While protein growth factors promote therapeutic angiogenesis, delivery of lipid factors such as sphingosine 1-phosphate (S1P) may provide better stabilization of newly formed vessels. We developed a biomaterial for the controlled delivery of S1P, a bioactive lipid released from activated platelets. Multiarm poly(ethylene glycol)-vinyl sulfone was cross-linked with albumin, a lipid-transporting protein, to form hydrogels. The rate of S1P release from the materials followed Fickian kinetics and was dependent upon the presence of lipid carriers in the release solution. Delivery of S1P from RGD-modified hydrogels increased the cell migration speed of endothelial cells growing on the materials. The materials also induced angiogenesis in the chorioallantoic membrane assay. Our data demonstrate that the storage and release of lipid factors provides a new route for the induction of angiogenesis by artificial materials.


Assuntos
Hidrogéis/química , Lisofosfolipídeos/química , Polietilenoglicóis/química , Esfingosina/análogos & derivados , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Sistemas de Liberação de Medicamentos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Géis/química , Humanos , Hidrogéis/síntese química , Hidrogéis/farmacologia , Estrutura Molecular , Polietilenoglicóis/síntese química , Polietilenoglicóis/farmacologia , Esfingosina/química , Fatores de Tempo
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