RESUMEN
BACKGROUND: Parent support for child physical activity is a consistent predictor of increased childhood activity. Little is known about factors that prevent or facilitate support. The purpose of this research was to identify barriers to parent support for child physical activity in Appalachian parents. METHODS: A cross-sectional study assessed parents whose children participated in Coronary Artery Risk Detection in Appalachian Communities (CARDIAC) screenings in a rural Appalachian state. Barriers to parental support for physical activity, demographics, geographic location, and parental support for activity were measured. RESULTS: A total of 475 parents completed surveys. The majority were mothers (86.7%), parents of kindergarteners (49.5%), white (89.3%), and living in a nonrural area (70.5%). Community-level factors were most frequently cited as barriers, particularly those related to the built environment. Rural and low-income parents reported significantly higher barriers. Community, interpersonal, and intrapersonal barriers were negatively correlated with parent support for child physical activity. Parents of girls reported a higher percentage of barriers related to safety. CONCLUSIONS: Reported barriers in this sample differed from those reported elsewhere (Davison, 2009). Specific groups such as low-income and rural parents should be targeted in intervention efforts. Future research should explore gender differences in reported barriers to determine the influence of cultural stereotypes.
Asunto(s)
Ejercicio Físico , Responsabilidad Parental , Apoyo Social , Adulto , Región de los Apalaches , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Renta , Masculino , Relaciones Padres-Hijo , Población Rural/estadística & datos numéricos , Factores Socioeconómicos , Encuestas y CuestionariosRESUMEN
The gelsolin related actin binding protein, Flii, is able to regulate wound healing; mice with decreased Flii expression show improved wound healing whereas mice with elevated Flii expression exhibit impaired wound healing. In both mice and humans Flii expression increases with age and amelioration of FLII activity represents a possible therapeutic strategy for improved wound healing in humans. Despite analysis of Flii function in a variety of organisms we know little of the molecular mechanisms underlying Flii action. Two new murine alleles of Flii have been produced to drive constitutive or tissue-specific expression of Flii. Each strain is able to rescue the embryonic lethality associated with a Flii null allele and to impair wound healing. These strains provide valuable resources for ongoing investigation of Flii function in a variety of biological processes.
Asunto(s)
Proteínas del Citoesqueleto/genética , Perfilación de la Expresión Génica , Piel/metabolismo , Cicatrización de Heridas/genética , Animales , Western Blotting , Encéfalo/metabolismo , Proteínas Portadoras , Proteínas del Citoesqueleto/metabolismo , Femenino , Genotipo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Transgénicos , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Músculos/metabolismo , Miocardio/metabolismo , Proteínas/genética , Proteínas/metabolismo , ARN no Traducido , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Piel/fisiopatología , Especificidad de la Especie , Bazo/metabolismo , Factores de Tiempo , Transactivadores , Cicatrización de Heridas/fisiologíaRESUMEN
Impaired wound healing in the elderly presents a major clinical challenge. Understanding the cellular mechanisms behind age-related impaired healing is vital for developing new wound therapies. Here we show that the actin-remodelling protein, Flightless I (FliI) is a contributing factor to the poor healing observed in elderly skin and that gender plays a major role in this process. Using young and aged, wild-type and FliI overexpressing mice we found that aging significantly elevated FliI expression in the epidermis and wound matrix. Aging exacerbated the negative effect of FliI on wound repair and wounds in aged FliI transgenic mice were larger with delayed reepithelialisation. When the effect of gender was further analysed, despite increased FliI expression in young and aged male and female mice, female FliI transgenic mice had the most severe wound healing phenotype suggesting that male mice were refractory to FliI gene expression. Of potential importance, males, but not females, up-regulated transforming growth factor-beta1 and this was most pronounced in aged male FliI overexpressing wounds. As FliI also functions as a co-activator of the estrogen nuclear receptor, increasing concentrations of beta-estradiol were added to skin fibroblasts and keratinocytes and significantly enhanced FliI expression and translocation of FliI from the cytoplasm to the nucleus was observed. FliI further inhibited estrogen-mediated collagen I secretion suggesting a mechanism via which FliI may directly affect provisional matrix synthesis. In summary, FliI is a contributing factor to impaired healing and strategies aimed at decreasing FliI levels in elderly skin may improve wound repair.
Asunto(s)
Envejecimiento/fisiología , Proteínas del Citoesqueleto/fisiología , Factor de Crecimiento Transformador beta1/fisiología , Cicatrización de Heridas/fisiología , Animales , Proteínas Portadoras , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas del Citoesqueleto/biosíntesis , Estradiol/farmacología , Femenino , Fibroblastos/metabolismo , Humanos , Masculino , Ratones , Ratones Transgénicos , Proteínas de Microfilamentos , Transporte de Proteínas , Factores Sexuales , Transactivadores , Regulación hacia ArribaRESUMEN
Homologues of the Drosophila melanogaster tweety (tty) gene are present in mammals and Caenorhabditis elegans. The encoded proteins have five predicted membrane-spanning regions and recent findings suggest that some family members may be chloride channels. Phylogenetic analysis of the tty family including novel members from slime mould Entamoeba and plants has revealed the occurrence of independent gene duplication events in different lineages. expressed sequence tag data indicate that expression of the mammalian Ttyh1 gene is restricted mainly to neural tissue and is up-regulated in astrocytoma, glioma and several other cancers. In this study, mammalian expression vectors were used to investigate the subcellular localization and the effect of over-expression of Ttyh1 in human epithelial kidney cells. The results confirm that Ttyh1 is a membrane protein and show that it is deposited on the substratum along the migration paths of motile cells above the alpha5beta1-integrin complex. The ectopic expression of Ttyh1 also induced long filopodia, which were branched and dynamic in both stationary and migratory cells. The filopodia contained F-actin and occurred at the ends of microtubules which were polarized towards the membrane. Upon contact with nearby cells some filopodia stabilized and filled with F-actin, whereas Ttyh1 was highly concentrated at the cell-cell interface. Ttyh1 N- and C-terminal antipeptide antibodies detected Ttyh1 along the axons of neurones in primary rat hippocampal cell cultures, and in situ in whole rat brain slices around the hippocampus and occasionally between cells. These data suggest a role for Ttyh1 in process formation, cell adhesion and possibly as a transmembrane receptor.
Asunto(s)
Encéfalo/crecimiento & desarrollo , Membrana Celular/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Actinas/metabolismo , Animales , Animales Recién Nacidos , Encéfalo/citología , Encéfalo/metabolismo , Adhesión Celular/fisiología , Línea Celular , Movimiento Celular/fisiología , Polaridad Celular/fisiología , Evolución Molecular , Regulación del Desarrollo de la Expresión Génica/genética , Humanos , Integrina alfa5/metabolismo , Proteínas de la Membrana/genética , Ratones , Proteínas del Tejido Nervioso/genética , Neuronas/citología , Técnicas de Cultivo de Órganos , Seudópodos/genética , Seudópodos/metabolismo , Ratas , Ratas Endogámicas BB , Ratas Long-Evans , Receptores de Superficie Celular/metabolismoRESUMEN
The gelsolin gene family encodes a number of higher eukaryotic actin-binding proteins that are thought to function in the cytoplasm by severing, capping, nucleating or bundling actin filaments. Recent evidence, however, suggests that several members of the gelsolin family may have adopted unexpected nuclear functions including a role in regulating transcription. In particular, flightless I, supervillin and gelsolin itself have roles as coactivators for nuclear receptors, despite the fact that their divergence appears to predate the evolutionary appearance of nuclear receptors. Flightless I has been shown to bind both actin and the actin-related BAF53a protein, which are subunits of SWI/SNF-like chromatin remodelling complexes. The primary sequences of some actin-related proteins such as BAF53a exhibit conservation of residues that, in actin itself, are known to interact with gelsolin-related proteins. In summary, there is a growing body of evidence supporting a biological role in the nucleus for actin, Arps and actin-binding proteins and, in particular, the gelsolin family of actin-binding proteins.
Asunto(s)
Gelsolina , Regulación de la Expresión Génica , Proteínas de Microfilamentos , Transcripción Genética , Animales , Ensamble y Desensamble de Cromatina , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Evolución Molecular , Gelsolina/clasificación , Gelsolina/genética , Gelsolina/metabolismo , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas de Microfilamentos/clasificación , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Familia de Multigenes , Filogenia , Proteína Proto-Oncogénica c-fli-1 , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Transactivadores/genética , Transactivadores/metabolismoRESUMEN
Hormone-activated nuclear receptors (NR) activate transcription by recruiting multiple coactivator complexes to the promoters of target genes. One important coactivator complex includes a p160 coactivator (e.g., GRIP1, SRC-1, or ACTR) that binds directly to activated NR, the histone acetyltransferase p300 or CBP, and the arginine-specific histone methyltransferase CARM1. We previously demonstrated that the coactivator function of CARM1 depends both on the methyltransferase activity and on additional unknown proteins that bind to CARM1. In this study a yeast two-hybrid screen for proteins that bind CARM1 identified the protein Flightless I (Fli-I), which has essential roles in Drosophila and mouse development. Fli-I bound to CARM1, GRIP1, and NRs and cooperated synergistically with CARM1 and GRIP1 to enhance NR function. Fli-I bound poorly to and did not cooperate with PRMT1, a CARM1-related protein arginine methyltransferase that also functions as an NR coactivator. The synergy between GRIP1, CARM1, and Fli-I required the methyltransferase activity of CARM1. The C-terminal AD1 (binding site for p300/CBP) and AD2 (binding site for CARM1) activation domains of GRIP1 contributed to the synergy but were less stringently required than the N-terminal region of GRIP1, which is the binding site for Fli-I. Endogenous Fli-I was recruited to the estrogen-regulated pS2 gene promoter of MCF-7 cells in response to the hormone, and reduction of endogenous Fli-I levels by small interfering RNA reduced hormone-stimulated gene expression by the endogenous estrogen receptor. A fragment of Fli-I that is related to the actin binding protein gelsolin enhanced estrogen receptor activity, and mutations that reduced actin binding also reduced the coactivator function of this Fli-I fragment. These data suggest that Fli-I may facilitate interaction of the p160 coactivator complex with other coactivators or coactivator complexes containing actin or actin-like proteins.
Asunto(s)
Actinas/metabolismo , Proteínas de Drosophila , Gelsolina , Proteínas Nucleares/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , Estradiol/metabolismo , Genes Reporteros , Humanos , Sustancias Macromoleculares , Proteínas de la Membrana , Ratones , Proteínas de Microfilamentos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/genética , Regiones Promotoras Genéticas , Unión Proteica , Estructura Terciaria de Proteína , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , ARN Interferente Pequeño/metabolismo , Receptores AMPA/genética , Receptores AMPA/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Transactivadores , Transcripción Genética , Técnicas del Sistema de Dos HíbridosRESUMEN
The Drosophila melanogaster flightless I gene is required for normal cellularization of the syncytial blastoderm. Highly conserved homologues of flightless I are present in Caenorhabditis elegans, mouse, and human. We have disrupted the mouse homologue Fliih by homologous recombination in embryonic stem cells. Heterozygous Fliih mutant mice develop normally, although the level of Fliih protein is reduced. Cultured homozygous Fliih mutant blastocysts hatch, attach, and form an outgrowing trophoblast cell layer, but egg cylinder formation fails and the embryos degenerate. Similarly, Fliih mutant embryos initiate implantation in vivo but then rapidly degenerate. We have constructed a transgenic mouse carrying the complete human FLII gene and shown that the FLII transgene is capable of rescuing the embryonic lethality of the homozygous targeted Fliih mutation. These results confirm the specific inactivation of the Fliih gene and establish that the human FLII gene and its gene product are functional in the mouse. The Fliih mouse mutant phenotype is much more severe than in the case of the related gelsolin family members gelsolin, villin, and CapG, where the homozygous mutant mice are viable and fertile but display alterations in cytoskeletal actin regulation.