Search

The primary cilium emanates from the cell surface of growth-arrested cells and plays a central role in vertebrate development and tissue homeostasis. The mechanisms that control ciliogenesis have been extensively explored. However, the intersection between GPCR signaling and the ubiquitin pathway in the control of cilium stability is unknown. Here, we observe that cAMP elevation promotes cilia resorption. At centriolar satellites, we identify a multimeric complex nucleated by PCM1 that includes two kinases, NEK10 and PKA, and the E3 ubiquitin ligase CHIP. We show that NEK10 is essential for ciliogenesis in mammals and for the development of medaka fish. PKA phosphorylation primes NEK10 for CHIP-mediated ubiquitination and proteolysis resulting in cilia resorption. Dearangement of this control mechanism occurs in proliferative and genetic disorders. These findings unveil a pericentriolar kinase signalosome that efficiently links the cAMP cascade with the ubiquitin-proteasome system, controlling essential aspects of ciliogenesis.

Mitochondria are the powerhouses of energy production and the sites where metabolic pathway and survival signals integrate and focus, promoting adaptive responses to hormone stimulation and nutrient availability. Increasing evidence suggests that mitochondrial bioenergetics, metabolism and signaling are linked to tumorigenesis. AKAP1 scaffolding protein integrates cAMP and src signaling on mitochondria, regulating organelle biogenesis, oxidative metabolism and cell survival. Here, we provide evidence that AKAP1 is a transcriptional target of Myc and supports the growth of cancer cells. We identify Sestrin2, a leucine sensor and inhibitor of the mammalian target of rapamycin (mTOR), as a novel component of the complex assembled by AKAP1 on mitochondria. Downregulation of AKAP1 impaired mTOR pathway and inhibited glioblastoma growth. Both effects were reversed by concomitant depletion of AKAP1 and sestrin2. High levels of AKAP1 were found in a wide variety of high-grade cancer tissues. In lung cancer, AKAP1 expression correlates with high levels of Myc, mTOR phosphorylation and reduced patient survival. Collectively, these data disclose a previously unrecognized role of AKAP1 in mTOR pathway regulation and cancer growth. AKAP1/mTOR signal integration on mitochondria may provide a new target for cancer therapy.

Cyanobacteria colonize different environments and blooms can occur both in contaminated and noncontaminated water bodies (freshwater, brackish and marine areas). In some cases, some bacterial species can produce toxins and this phenomenon can have a negative impact on ecosystem and human health. Inside 150 genera of cyanobacteria known, more than 40 species are able to produce toxins. The latter are natural compounds which differ from both chemical and toxicological point of view; they are responsible for both acute and chronic poisoning in animals and humans. Among the main classes of cyanotoxins, microcystins are frequently found in the environment. These toxins are mainly accumulated in liver, but also in intestine and kidneys and can be very dangerous for animal and human health [1]. Fast and sensitive methods to identify unequivocally species belonging to Microcystis and Planktothrix genera are necessary to discriminate these genera respect to the other non-toxic cyanobacteria. For this purpose, we designed, developed and validated some oligonucleotide probes for FISH (Fluorescence In Situ Hybridization) analysis in order to detect them in freshwater. The FISH probes were designed using the ARB software with the Silva database in the framework of the MicroCoKit project. We have focused on identification of Microcystis aeruginosa and Planktothrix agardii species because they are among the most common toxic cyanobacteria in freshwater. We tested different fixative methods to minimise the natural autofluorescence from chlorophyll-a and some accessories pigments (e.g. phycobilins and carotenoids) in order to visualize Microcystis aeruginosa and Planktothrix agardii under a laser confocal microscope. Firstly, the FISH probes designed (GNPlankS02, PkAgD03, MicAerD03) have been tested on pure cultures of M. aeruginosa and P. agardii species. Then the probes were successfully applied to several water samples collected from the River Tiber and Lake Albano (Italy).

cAMP signals are received and transmitted by multiple isoforms of cAMP-dependent protein kinases, typically determined by their specific regulatory subunits. In the brain the major regulatory isoform RIIbeta and the RII-anchor protein, AKAP150 (rat) or 75 (bovine), are differentially expressed. Cortical neurons express RIIbeta and AKAP75; conversely, granule cerebellar cells express predominantly RIalpha and RIIalpha. Cortical neurons accumulate PKA catalytic subunit and phosphorylated cAMP responsive element binding protein very efficiently into nuclei upon cAMP induction, whereas granule cerebellar cells fail to do so. Down-regulation of RIIbeta synthesis by antisense oligonucleotides inhibited cAMP-induced nuclear signaling in cortical neurons. Expression in cerebellar granule cells of RIIbeta and AKAP75 genes by microinjection of specific expression vectors, markedly stimulated cAMP-induced transcription of the lacZ gene driven by a cAMP-responsive element promoter. These data indicate that the composition of PKA in cortical and granule cells underlies the differential ability of these cells to transmit cAMP signals to the nucleus.

Microbial communities are the base of the food web pyramid, representing about 50% of the total biomass on Earth. They are responsible for the geochemical cycles and bio-removal of organic compounds and xenobiotics playing a key-role in the ecosystem function. Their capability to adapt quickly not only to the changes but also to take the advantages, makes them the drivers of the aquatic and terrestrial ecosystem and the human health. In Europe, the good quality of surface waters is established under the Water Framework Directive (WFD) based either on the chemical monitoring, or on the ecological status and pathogen detection in drinking and bathing waters. However, no indicator is foreseen which would provide a link between ecological and chemical pollutants and other anthropogenic pressures; currently water quality monitoring are either focused on ecological parameters or only chemical pollutants. The MicroCokit Project, a Marie Curie Industry-Academia Partnerships and Pathways (FP7-PEOPLE-2012-IAPP), a close collaboration of Academic groups with European Commission Joint Research Centre and leading private Enterprises, has been conceived to i) investigate and identify complex stressor indicators based on microbial communities; ii) foster the transfer of knowledge among the partners with the final goal to bring to market faster, more sensitive and robust tools as bioindicators of water quality. The tools will be developed according different kinds of bioindicators, targeting microbial community, pathogen and specific microorganisms. For this purpose the river Tiber has been chosen as a pilot case study and sampling sites were selected based on different anthropogenic pressures which they are exposed to. For each site water sample will be analyzed for both microbiological (Microarray, Metagenomic and FISH analysis) and chemical analysis (organic and inorganic compounds, including emerging pollutants). Following the validation, these data could be then integrated in a modeling system to predict, prevent and mitigate the impact of anthropogenic pressure on water management.

Nerve growth factor (NGF) induces terminal differentiation in PC12, a pheochromocytoma-derived cell line. NGF binds a specific receptor on the membrane and triggers the ERK1/2 cascade, which stimulates the transcription of neural genes. We report that NGF significantly affects mitochondrial metabolism by reducing mitochondrial-produced reactive oxygen species and stabilizing the electrochemical gradient. This is accomplished by stimulation of mitochondrial manganese superoxide dismutase (MnSOD) both transcriptionally and post-transcriptionally via Ki-Ras and ERK1/2. Activation of MnSOD is essential for completion of neuronal differentiation because 1) expression of MnSOD induces the transcription of a neuronal specific promoter and neurite outgrowth, 2) silencing of endogenous MnSOD by small interfering RNA significantly reduces transcription induced by NGF, and 3) a Ki-Ras mutant in the polylysine stretch at the COOH terminus, unable to stimulate MnSOD, fails to induce complete differentiation. Overexpression of MnSOD restores differentiation in cells expressing this mutant. ERK1/2 is also downstream of MnSOD, as a SOD mimetic drug stimulates ERK1/2 with the same kinetics of NGF and silencing of MnSOD reduces NGF-induced late ERK1/2. Long term activation of ERK1/2 by NGF requires SOD activation, low levels of hydrogen peroxide, and the integrity of the microtubular cytoskeleton. Confocal immunofluorescence shows that NGF stimulates the formation of a complex containing membrane-bound Ki-Ras, microtubules, and mitochondria. We propose that active NGF receptor induces association of mitochondria with plasma membrane. Local activation of ERK1/2 by Ki-Ras stimulates mitochondrial SOD, which reduces reactive oxygen species and produces H(2)O(2). Low and spatially restricted levels of H(2)O(2) induce and maintain long term ERK1/2 activity and ultimately differentiation of PC12 cells.

El objetivo de este Proyecto es el de formar Agentes Multiplicadores con criterio bromatológico que fomenten normas de control sanitario, aseguren la calidad e inocuidad de los alimentos que llegan al consumidor y apoyen la transformación, a través de Capacitación y Asistencia técnica, teniendo como punto de partida la Educación para la Salud y la Educación Ecológica., Mesa: Alimentos y Vacunas., Facultad de Ciencias Veterinarias

La rabia es una enfermedad infecciosa, zoonótica, caracterizada por alteraciones del sistema nervioso, producida por el virus de la rabia, perteneciente al Género Lyssavirus de la Familia Rhabdoviridae. Es habitualmente transmitida por la mordedura de un animal rabioso que elimina el virus por la saliva. La rabia urbana es la que ocurre en las ciudades, siendo el perro el transmisor y afectado más importante, seguido por el gato y el hombre. El presente trabajo presenta un enfoque global sobre la rabia urbana, enfermedad de los animales y el hombre, en el territorio de la provincia de Buenos Aires, Argentina, hasta el año 2001. Esta provincia presentó el mayor foco de rabia urbana que registró el país desde su aparición en 1806 a consecuencia de las actividades de la 1º invasión inglesa, hasta su erradicación en el año 1984. Durante 1976, el territorio provincial registró 4.759 casos de rabia animal y trece decesos humanos. Se efectúa un encuadre de las situaciones geográficas y políticas de las épocas en que se produjeron acontecimientos importantes y del estado de los conocimientos científicos sobre la enfermedad en esos momentos, que condicionaron y caracterizaron la presentación, manejo y control de esta enfermedad en la provincia., Rabies is an infectious and zoonotic disease characterized by alterations of the nervous system, produced by the rabies virus, which belongs to the genus Lyssavirus of the Rhabdoviridae family. The disease is habitually transmitted by the bite of an infected animal, which eliminates the virus in its saliva. Urban rabies is the one that occurs in the cities, being the dog the most important affected and transmitter of the disease, followed by cat and man. The present work shows a global focus on rabies, animal and man affecting disease, in the territory of the province of Buenos Aires, Argentina. This province presented the biggest focus of urban rabies ever registered in the Argentinian Republic from the moment of the first appearance of the disease, consigned in 1806 and due to the activities of the 1 English Invasion, to the moment of the eradication of the disease in 1984. The subsequent panorama, until 2001 is also following presented. During 1976, the province´s territory registered 4759 cases of animal rabies and 13 human deaths. An alignment of the geographical and political situations of the periods during which important events happened is made. Besides, the state of the scientific knowledge about the disease during these periods, which conditioned and characterized the presentation, handling and control of this disease in the province of Buenos Aires, Argentina, is also analyzed., Facultad de Ciencias Veterinarias

We have studied the expression of cell polarity in hybrids between two rat thyroid epithelial cells: FRT and FRTL-5. FRT cells are polarized but do not express tissue-specific properties, FRTL-5 are unpolarized and express many thyroid-specific genes. A and express many thyroid-specific genes. A pool of 170 hybrid clones and five independent clones were characterized. The chromosome complement was that expected from 1:1 fusion of the parental cells. No chromosome loss was observed for several generations. All hybrids were polarized as judged from: (1) morphology, (2) transepithelial resistance, (3) preferential secretion of several proteins either through the apical (e.g. thyroglobulin) or through the basolateral pole, and (4) basolateral trapping of iodide. On the other hand, the expression of thyroid-specific markers: thyroglobulin synthesis and secretion, trapping of iodide, thyrotropin-dependent growth and expression of specific membrane antigens, were greatly reduced or inhibited in the pool and in the isolated clones. We also found that reduction of thyroglobulin synthesis was correlated with the loss of activity of the trans-acting factor TgTF1. We conclude that cell polarity, a property of FRT cells, is dominant in the hybrids whereas thyroid differentiation is recessive.

B16-BL6 mouse melanoma cells cultured on fibronectin coated dishes were detached by treatment with echistatin, an RGD-containing disintegrin. Echistatin was active at micromolar concentrations and was not cytotoxic. Its effect was dose-dependent and reversible. Sequential morphological changes leading to rounding up of the cells were deterred by phase-contrast microscopy and by immuno fluorescence analysis. A dramatic reduction in the number and size of focal adhesions and loss of cytoplasmic actin filaments were observed well before cell detachment occurred. Echistatin treatment down-regulated the phosphorylation of pp125(FAK) in fibronectin-adherent cells in a dose-and time-dependent fashion. The reduction of pp125(FAK) phosphorylation preceded cell detachment and occurred even in the presence of orthovanadate, an inhibitor of protein tyrosine phosphatases. These results suggest that echistatin detaches cells from the fibronectin substratum by inducing a decrease of pp125(FAK) phosphorylation and that echistatin acts by inhibiting protein tyrosine kinase activity rather than activating protein tyrosine phosphatases.