In vitro and in vivo expression of foreign genes by transmissible gastroenteritis coronavirus-derived minigenomes

A helper-dependent expression system based on transmissible gastroenteritis coronavirus (TGEV) has been developed using a minigenome of 3·9 kb (M39). Expression of the reporter gene {beta}-glucuronidase (GUS) (2–8 µg per 106 cells) and the porcine respiratory and reproductive syndrome virus (PRRSV) ORF5 (1–2 µg per 106 cells) has been shown using a TGEV-derived minigenome. GUS expression levels increased about eightfold with the m.o.i. and were maintained for more than eight passages in cell culture. Nevertheless, instability of the GUS and ORF5 subgenomic mRNAs was observed from passages five and four, respectively. About a quarter of the cells in culture expressing the helper virus also produced the reporter gene as determined by studying GUS mRNA production by in situ hybridization or immunodetection to visualize the protein synthesized. Expression of GUS was detected in the lungs, but not in the gut, of swine immunized with the virus vector. Around a quarter of lung cells showing replication of the helper virus were also positive for the reporter gene. Interestingly, strong humoral immune responses to both GUS and PRRSV ORF5 were induced in swine with this virus vector. The large cloning capacity and the tissue specificity of the TGEV-derived minigenomes suggest that these virus vectors are very promising for vaccine development

Human breast milk exosomes accelerate mouse wound healing

P543 The healing of cutaneous wounds is a very efficient process despite being very complex. Under certain pathological conditions healing may be impaired, prolonging the healing process and eventually leading to medical intervention and the chronicity of the wound. Exosomes are secreted extracellular vesicles present in biological fluids where they play a key role in intercellular communication at the tissue, organ and organismal levels. Given that human breast milk contains abundant maternal extracellular vesicles (MEVs) with pro-regenerative and immunomodulatory properties, the aim of the present study was to evaluate if topical application ofMEVs into open wounds would be beneficial for healing. Full-thickness excision wounds of 4-mm diameter were created in the dorsal skin of C57BL/6 mice and topical application of 20 micrograms of human MEV isolated at weeks 9, 11, 12 and 15 postpartum of breastfeeding were placed onto the open wounds. Control wounds were vehicle-treated. Macroscopic measurements up to 7 days postwounding revealed that the area of the wound treated with MEV significantly decreased compared with controls. Histological analyses at day 7 post-wounding showed no differences in the granulation tissue area between groups. ..

Validación de material educativo: estrategia sobre alimentación y actividad física en escuelas mexicanas = Validation of educational material: strategy on food and physical activity in elementary schools in Mexico

Resumen: Introducción. Ante la necesidad de desarrollar materiales educativos que trasmitan mensajes claros y adecuados en salud, se realizó la validación de diversos materiales que apoyan la campaña “Recreo Saludable” que promueve estilos de vida saludable. Objetivo. Validar seis materiales impresos y cinco audiovisuales diseñados para promover una alimentación saludable, el incremento de actividad física y el consumo de agua pura. Material y método. Se seleccionaron por muestreo ocho escuelas primarias. Se realizó un estudio mixto de enfoque cuantitativo centrado en encuestas, y cualitativo fundamentado en entrevistas estructuradas. El análisis cualitativo se hizo con base en el contenido del discurso de los criterios explorados. Para el análisis cuantitativo se estimaron frecuencias con intervalos de confianza de 95%. Resultados. Para los criterios explorados se obtuvieron los siguientes resultados, entendimiento 87%, aceptación 78%, atracción 74%, inducción a la acción 93%, identificación 35%, lo que indica una validación positiva en la mayoría de las categorías. Los datos cualitativos aportaron aproximaciones necesarias para mejorar el contenido y el diseño de los materiales. Conclusión. Los resultados muestran que el material validado fue aceptado por la población e hicieron aportaciones para mejorarlo y con esto poder garantizar, la efectividad y aplicabilidad de estos como recurso pedagógico en estrategias educativas. Palabras clave: estudios de validación, materiales educativos y de divulgación, educación alimentaria y nutricional, actividad motora, educación en salud Abstract: Introduction. Given the need to develop educational materials that convey clear and appropriate messages on health, we performed the validation of various resources promoting healthy lifestyles that support the campaign "Healthy Recess". Objective. To validate six printed materials and five audiovisual ones, designed to promote healthy eating, increased physical activity and consumption of pure water. Material and methods. Eight elementary schools were selected for sampling. A joint study was conducted focused on surveys with a quantitative approach, based on structured qualitative interviews. Qualitative analysis was based on the content of the discourse of the criteria explored. Frequencies with confidence the explored criteria: understanding 87%; accepting 78%; appeal 74%; induction to action 93%; affinity 35%; which indicates a positive validation in most categories. Qualitative data provided necessary approximations to improve the content and layout of the materials. Conclusion. The results show that the validated material was accepted by the population and they contributed to its improvement, thereby ensuring the effectiveness and applicability of these as a pedagogical resource in educational strategies.Keywords: validation studies, educational and outreach materials, food and nutrition education, motor activity, health educatio

Murine muscle engineered from dermal precursors: an in vitro model for skeletal muscle generation, degeneration and fatty infiltration.

Skeletal muscle can be engineered by converting dermal precursors into muscle progenitors and differentiated myocytes. However, the efficiency of muscle development remains relatively low and it is currently unclear if this is due to poor characterization of the myogenic precursors, the protocols used for cell differentiation, or a combination of both. In this study, we characterized myogenic precursors present in murine dermospheres, and evaluated mature myotubes grown in a novel three-dimensional culture system. After 57 days of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct on an extracellular matrix (ECM). In vitro engineered myofibers expressed canonical muscle markers and exhibited a skeletal (not cardiac) muscle ultrastructure, with numerous striations and the presence of aligned, enlarged mitochondria, intertwined with sarcoplasmic reticula (SR). Engineered myofibers exhibited Na+- and Ca2+-dependent inward currents upon acetylcholine (ACh) stimulation and tetrodotoxin-sensitive spontaneous action potentials. Moreover, ACh, nicotine, and caffeine elicited cytosolic Ca2+ transients; fiber contractions coupled to these Ca2+ transients suggest that Ca2+ entry is activating calcium-induced calcium release from the SR. Blockade by d-tubocurarine of ACh-elicited inward currents and Ca2+ transients suggests nicotinic receptor involvement. Interestingly, after 1 month, engineered muscle constructs showed progressive degradation of the myofibers concomitant with fatty infiltration, paralleling the natural course of muscular degeneration. We conclude that mature myofibers may be differentiated on the ECM from myogenic precursor cells present in murine dermospheres, in an in vitro system that mimics some characteristics found in aging and muscular degeneration

Epigenetic Regulation of Histone H3 Serine 10 Phosphorylation Status by HCF-1 Proteins in C. elegans and Mammalian Cells

BACKGROUND: The human herpes simplex virus (HSV) host cell factor HCF-1 is a transcriptional coregulator that associates with both histone methyl- and acetyltransferases, and a histone deacetylase and regulates cell proliferation and division. In HSV-infected cells, HCF-1 associates with the viral protein VP16 to promote formation of a multiprotein-DNA transcriptional activator complex. The ability of HCF proteins to stabilize this VP16-induced complex has been conserved in diverse animal species including Drosophila melanogaster and Caenorhabditis elegans suggesting that VP16 targets a conserved cellular function of HCF-1. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the role of HCF proteins in animal development, we have characterized the effects of loss of the HCF-1 homolog in C. elegans, called Ce HCF-1. Two large hcf-1 deletion mutants (pk924 and ok559) are viable but display reduced fertility. Loss of Ce HCF-1 protein at reduced temperatures (e.g., 12 degrees C), however, leads to a high incidence of embryonic lethality and early embryonic mitotic and cytokinetic defects reminiscent of mammalian cell-division defects upon loss of HCF-1 function. Even when viable, however, at normal temperature, mutant embryos display reduced levels of phospho-histone H3 serine 10 (H3S10P), a modification implicated in both transcriptional and mitotic regulation. Mammalian cells with defective HCF-1 also display defects in mitotic H3S10P status. CONCLUSIONS/SIGNIFICANCE: These results suggest that HCF-1 proteins possess conserved roles in the regulation of cell division and mitotic histone phosphorylation

HuR/ELAVL1 drives malignant peripheral nerve sheath tumor growth and metastasis

Cancer cells can develop a strong addiction to discrete molecular regulators, which control the aberrant gene expression programs that drive and maintain the cancer phenotype. Here, we report the identification of the RNA-binding protein HuR/ELAVL1 as a central oncogenic driver for malignant peripheral nerve sheath tumors (MPNSTs), which are highly aggressive sarcomas that originate from cells of the Schwann cell lineage. HuR was found to be highly elevated and bound to a multitude of cancer-associated transcripts in human MPNST samples. Accordingly, genetic and pharmacological inhibition of HuR had potent cytostatic and cytotoxic effects on tumor growth, and strongly suppressed metastatic capacity in vivo. Importantly, we linked the profound tumorigenic function of HuR to its ability to simultaneously regulate multiple essential oncogenic pathways in MPNST cells, including the Wnt/β-catenin, YAP/TAZ, RB/E2F, and BET pathways, which converge on key transcriptional networks. Given the exceptional dependency of MPNST cells on HuR for survival, proliferation, and dissemination, we propose that HuR represents a promising therapeutic target for MPNST treatment

Coronavirus Gene 7 Counteracts Host Defenses and Modulates Virus Virulence

Transmissible gastroenteritis virus (TGEV) genome contains three accessory genes: 3a, 3b and 7. Gene 7 is only present in members of coronavirus genus a1, and encodes a hydrophobic protein of 78 aa. To study gene 7 function, a recombinant TGEV virus lacking gene 7 was engineered (rTGEV-Δ7). Both the mutant and the parental (rTGEV-wt) viruses showed the same growth and viral RNA accumulation kinetics in tissue cultures. Nevertheless, cells infected with rTGEV-Δ7 virus showed an increased cytopathic effect caused by an enhanced apoptosis mediated by caspase activation. Macromolecular synthesis analysis showed that rTGEV-Δ7 virus infection led to host translational shut-off and increased cellular RNA degradation compared with rTGEV-wt infection. An increase of eukaryotic translation initiation factor 2 (eIF2α) phosphorylation and an enhanced nuclease, most likely RNase L, activity were observed in rTGEV-Δ7 virus infected cells. These results suggested that the removal of gene 7 promoted an intensified dsRNA-activated host antiviral response. In protein 7 a conserved sequence motif that potentially mediates binding to protein phosphatase 1 catalytic subunit (PP1c), a key regulator of the cell antiviral defenses, was identified. We postulated that TGEV protein 7 may counteract host antiviral response by its association with PP1c. In fact, pull-down assays demonstrated the interaction between TGEV protein 7, but not a protein 7 mutant lacking PP1c binding motif, with PP1. Moreover, the interaction between protein 7 and PP1 was required, during the infection, for eIF2α dephosphorylation and inhibition of cell RNA degradation. Inoculation of newborn piglets with rTGEV-Δ7 and rTGEV-wt viruses showed that rTGEV-Δ7 virus presented accelerated growth kinetics and pathology compared with the parental virus. Overall, the results indicated that gene 7 counteracted host cell defenses, and modified TGEV persistence increasing TGEV survival. Therefore, the acquisition of gene 7 by the TGEV genome most likely has provided a selective advantage to the virus