Influencia de la suplementación del medio de cultivo con ácido linoleico en la supervivencia a la congelación de embriones bovinos

Studies report that the addition of linoleic acid to bovine embryo production media in vitro improves its resistance to conventional freezing. In this study the effect on survival of in vitro bovine embryos under freezing was evaluated by the addition of linoleic acid (LA) in the culture medium on days 3 or 5. A total of 1452 oocytes were recovered and assigned to 4 experimental groups and a control group. Six replicates were made to obtain approximately 100 freeze-thawed embryos per group. Group 1: 100 M on Day 3, group 2: 50 M on Day 3, group 3: 100 M on Day 5, group 4: 50 M on Day 5. The embryos were frozen and one week after they were thawed to evaluate the percentages of re-expansion (24 h) and hatching (72 h). The results were analyzed by ANOVA and when the differences were significant, the means between the groups were compared by Fischer's LSD Test (p <0.05). It was observed that the percentage of re-expansion was significantly improved with the addition of 50 μM LA on Day 5 (54.94 ± 28.8 vs. 19.19 ± 28.4, p = 0.001) and the percentage of hatching with the addition of 50 μM of LA at day 3 (37.9 ± 18.3 vs. 9.02 ± 12.0, p = 0.014), when them were compared with the control group. In conclusion, the addition of linoleic acid improves the survival to freezing of bovine embryos produced by in vitro techniquesEstudios reportan que la adición de ácido linoleico en los medios de producción de embriones bovinos in vitro, mejora su resistencia a la congelación convencional. En este estudio se evaluó el efecto en la supervivencia de embriones bovinos in vitro a la congelación, mediante la adición de ácido linoleico (LA) en el medio de cultivo los días 3 o 5. Un total de 1452 oocitos fueron recuperados y asignados a 4 grupos experimentales y un grupo control. Se realizaron seis réplicas, para obtener aproximadamente 100 embriones congelables por grupo. Grupo 1: 100 M en Día 3, grupo 2: 50 M en Día 3, grupo 3: 100 M en Día 5, grupo 4: 50 M en Día 5. Los embriones se congelaron y a la semana fueron descongelados para evaluar los porcentajes de re-expansión (24 h) y de eclosión (72 h). Los resultados fueron analizados mediante ANOVA y cuando las diferencias fueron significativas, se compararon las medias entre los grupos por el Test LSD de Fischer (p < 0.05). Se observó que el porcentaje de re-expansión mejoró significativamente con la adición de 50 M de LA en el Día 5 (54.94 ± 28.8 vs. 19.19 ± 28.4, p = 0.001) y el porcentaje de eclosión con la adición de 50 M de LA en el Día 3 (37.9 ± 18.3 vs. 9.02 ± 12.0, p = 0.014), cuando se comparó con el grupo control. En conclusión, la adición de ácido linoleico mejora la supervivencia a la congelación de los embriones bovinos producidos mediante técnicas in vitrFil: Bernal Ballesteros, Beatriz H.. Instituto de Reproducción Animal Córdoba; Argentina. Vitrogen Colombia S.A.S; ColombiaFil: Tribulo, Humberto Elias. Instituto de Reproducción Animal Córdoba; ArgentinaFil: Mutto, Adrián Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Bo, Gabriel Amilcar. Instituto de Reproducción Animal Córdoba; Argentina. Universidad Nacional de Villa María; Argentin

SLUG transcription factor : a pro-survival and prognostic factor in gastrointestinal stromal tumour

Background: The SLUG transcription factor has been linked with the KIT signalling pathway that is important for gastrointestinal stromal tumour (GIST) tumourigenesis. Its clinical significance in GIST is unknown. Methods: Influence of SLUG expression on cell proliferation and viability were investigated in GIST48 and GIST882 cell lines. The association between tumour SLUG expression in immunohistochemistry and recurrence-free survival (RFS) was studied in two clinical GIST series, one with 187 patients treated with surgery alone, and another one with 313 patients treated with surgery and adjuvant imatinib. Results: SLUG downregulation inhibited cell proliferation, induced cell death in both cell lines, and sensitised GIST882 cells to lower imatinib concentrations. SLUG was expressed in 125 (25.0%) of the 500 clinical GISTs evaluated, and expression was associated with several factors linked with unfavourable prognosis. SLUG expression was associated with unfavourable RFS both when patients were treated with surgery alone (HR = 3.40, 95% CI = 1.67-6.89, P = 0.001) and when treated with surgery plus adjuvant imatinib (HR = 1.83, 95% CI = 1.29-2.60, P = 0.001). Conclusions: GIST patients with high tumour SLUG expression have unfavourable RFS. SLUG may mediate pro-survival signalling in GISTs.Peer reviewe

SNW1 Is a Critical Regulator of Spatial BMP Activity, Neural Plate Border Formation, and Neural Crest Specification in Vertebrate Embryos

In frog and fish embryos, SNW1 is a protein required for the spatio-temporal activity of BMP signaling necessary for neural plate border formation and specification of neural crest tissue

An NF-κB and Slug Regulatory Loop Active in Early Vertebrate Mesoderm

BACKGROUND: In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis. METHODOLOGY & PRINCIPLE FINDINGS: Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IκB kinase-mediated activation of the bipartite transcription factor NF-κB. NF-κB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-κB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA. CONCLUSIONS/SIGNIFICANCE: These studies reveal a Slug/Snail–NF-κB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease

Current perspectives of the signaling pathways directing neural crest induction

The neural crest is a migratory population of embryonic cells with a tremendous potential to differentiate and contribute to nearly every organ system in the adult body. Over the past two decades, an incredible amount of research has given us a reasonable understanding of how these cells are generated. Neural crest induction involves the combinatorial input of multiple signaling pathways and transcription factors, and is thought to occur in two phases from gastrulation to neurulation. In the first phase, FGF and Wnt signaling induce NC progenitors at the border of the neural plate, activating the expression of members of the Msx, Pax, and Zic families, among others. In the second phase, BMP, Wnt, and Notch signaling maintain these progenitors and bring about the expression of definitive NC markers including Snail2, FoxD3, and Sox9/10. In recent years, additional signaling molecules and modulators of these pathways have been uncovered, creating an increasingly complex regulatory network. In this work, we provide a comprehensive review of the major signaling pathways that participate in neural crest induction, with a focus on recent developments and current perspectives. We provide a simplified model of early neural crest development and stress similarities and differences between four major model organisms: Xenopus, chick, zebrafish, and mouse