Epithelial-to-mesenchymal transition (EMT) is essential for embryonic morphogenesis and wound healing and critical for tumour cell invasion and dissemination. The AP-1 transcription factor Fra-1 has been implicated in tumorigenesis and in tumour-associated EMT in human breast cancer. We observed a significant inverse correlation between Fra-1 mRNA expression and distant-metastasis-free survival in a large cohort of breast cancer patients derived from multiple array data sets. This unique correlation among Fos genes prompted us to assess the evolutionary conservation between Fra-1 functions in EMT of human and mouse cells. Ectopic expression of Fra-1 in fully polarized, non-tumourigenic, mouse mammary epithelial EpH4 cells induced a mesenchymal phenotype, characterized by a loss of epithelial and gain of mesenchymal markers. Proliferation, motility and invasiveness were also increased in the resulting EpFra1 cells, and the cells were tumourigenic and efficiently colonized the lung upon transplantation. Molecular analyses revealed increased expression of Tgfβ1 and the EMT-inducing transcription factors Zeb1, Zeb2 and Slug. Mechanistically, Fra-1 binds to the tgfb1 and zeb2 promoters and to an evolutionarily conserved region in the first intron of zeb1. Furthermore, increased activity of a zeb2 promoter reporter was detected in EpFra1 cells and shown to depend on AP-1-binding sites. Inhibiting TGFβ signalling in EpFra1 cells moderately increased the expression of epithelial markers, whereas silencing of zeb1 or zeb2 restored the epithelial phenotype and decreased migration in vitro and tumorigenesis in vivo. Thus Fra-1 induces changes in the expression of genes encoding EMT-related transcription factors leading to the acquisition of mesenchymal, invasive and tumorigenic capacities by epithelial cells. This study defines a novel function of Fra-1/AP-1 in modulating tgfb1, zeb1 and zeb2 expression through direct binding to genomic regulatory regions, which establishes a basis for future in vivo genetic manipulations and preclinical studies using mouse models. Epithelial-to-mesenchymal transition (EMT) is a complex biological programme that occurs in physiological processes during embryonic development and wound healing as well as in pathological conditions, such as organ fibrosis and carcinogenesis. During EMT, cells lose epithelial features and acquire mesenchymal characteristics. The acquisition of a mesenchymal state by malignant cancer cells is associated with decreased cell-cell adhesion, and increased migratory and invasive properties, which are crucial for metastasis. [1][2][3][4][5] The adherens junction (AJ) protein E-cadherin, encoded by cdh1, is a central determinant of the epithelial state and its downregulation is the hallmark of EMT. A number of molecular pathways converging on E-cadherin have been implicated in EMT. Transcription factors (TF) of the Snail, Zeb and Twist families, initially identified as regulators of epithelialmesenchymal plasticity during morphogenesis were shown to orchestrate EMT by...

Copper is a key element affecting blood vessel growth and muscle development. However, the ions released from Cu salts are toxic. Given their specific physicochemical properties, nanoparticles of Cu (NanoCu) may have different bioactivity and affect the development of blood vessel and muscles in a different manner than Cu salts. The objective of the study was to evaluate the influence of NanoCu on embryo development and angiogenesis at the systemic and molecular level, in experiments using a chick embryo model. Fertilized chicken eggs were divided into a control group, and groups injected with a placebo, CuSO4 or NanoCu. Embryo development at the whole body level and molecular indices using an embryo chorioallantoic membrane model were measured during embryogenesis. The present study indicated for the first time that NanoCu have pro-angiogenic properties at the systemic level, to a greater degree than CuSO4 salt. The properties of NanoCu were confirmed at the molecular level, demonstrating significant effects on mRNA concentration and on mRNA gene expression of all pro-angiogenic and pro-proliferative genes measured herein.

The in ovo application of Cu colloids may ensure an efficient penetration of Cu into the embryonic tissue with long lasting effects on postnatal growth. The method may provide a successful alternative to using Cu as a feed additive. © 2015 Society of Chemical Industry.

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An effect of modification of storage conditions of the eggs of broiler breeder flocks at the age of 49-, 52- and 70-, 73-wks of life on an early embryonic development, hatching time and synchronization, hatchability rates, chicks quality and broiler growth was investigated. The eggs were divided into 4 experimental groups: COI = eggs storage 5 d, at turning every 12 h; NSP = eggs storage 12 d, at turning every 12 h; SPIDES = were treated with 4 h pre-incubation at 30°C and 50-55% air humidity, delivered at 5 and 10 d over of 12 d of storage, and turning every 12 h; NCOI = eggs storage 12 d, no turning and no pre-incubation. Eggs from older hens were characterized by poorer hatchability and poorer chicks quality. The use of 2 × 4 h pre-incubation in 12 d of eggs storage could have an effect on the initial acceleration of embryonic development in eggs of young hens, contributing to the alignment of embryos development in eggs from young and older hens to 72 h of incubation. Pre-incubation had no effect on the length of incubation period, hatching window, but it increased the hatchability of the set and apparently fertilized eggs and decreased the number of eggs not hatched, and also improved chicks quality. Eggs turning by 90° every 12 h during the storage positively affected the embryonic development, shortening the incubation time and the quality of chicks, but had no effect on hatchability rates and body weight in 42 d of life. Based on the obtained results, it can be concluded that the applied modifications can be effective in counteracting the negative effects of storage of hatching eggs from both young and older birds.

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This study was aimed at determining the effect of housing systems on the growth, feed conversion ratio (FCR), meatiness and size of muscle fibres of Pekin (P44) and Muscovy (MR71) ducks. Each genetic group included 360 birds (180 males and 180 females). The ducks were divided into four experimental groups according to their sex and housing system: intensive system (IS) and outdoor system (OS). A significant effect of housing system on the final body weight and FCR value was noted only in P44 birds of both sexes, with OS birds having higher body weights than the IS birds. As a result, the OS MR71 drakes were characterized by a significantly higher slaughter yield, weight and content of breast muscles in the carcass. The OS MR71 ducks showed a lower slaughter yield and a higher content of leg muscles in the carcass compared to IS MR71 ducks. In contrast, the housing system had no significant effect on the meatiness of P44 ducks. A greater diameter of muscle fibres in both sexes of P44 ducks and in both sexes of MR71 ducks was observed in the OS compared to IS flocks. A greater cross section of muscle fibres was also noted in the ducks from the OS system, however with significant differences confirmed only in pectoralis superficialis and biceps femoris in MR71 drakes as well as in the biceps femoris of P44 drakes. These data show differences between duck genotypes and indicate the efficiency and potential of outdoor poultry systems. ______________________________________________________________________________________