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Influence of a GMO-containing diet on pancreatic acinar cells of adult mice: effects of a short-term diet reversion
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Effetti sul topo di un’alimentazione contenente soia GM
No full textIl lavoro descrive gli effetti di un’alimentazione contenente soia GM su vari organi di top
Immunolocalizzazione della proteina clock negli epatociti di ghiri eutermici e ibernanti
No full textInfluence of a GMO-containing diet on pancreatic acinar cells of adult mice: effects of a short-term diet reversion
No full textPrevious studies on mice fed on a genetically modified (GM) soybean showed that changes in zymogen synthesis and processing as well as in cell nuclear activity take place in pancreatic acinar cells. In this study, we aimed at elucidating whether these modifications can be reversed. To do this, mice fed on GM soybean from their weaning to the third month of age were administered a diet containing control soybean for one additional month. In parallel, to investigate the influence of GM soybean on adult individuals, 3 month-old mice fed from their weaning on control soybean were administered a GM-containing diet for one month. Morphometry, cytochemistry and immunocytochemistry were used to analyse pancreatic acinar cells at light and electron microscopy. Our results demonstrate that a one month-diet reversion in adult mice can influence some morpho-functional features of pancreatic acinar cells, restoring in GM-fed mice some characteristics typical of controls and inducing in control mice modifications similar to those observed in animals fed on GM soybean from weaning. This implies that the modifications related to GM soybean are potentially reversible, but also that some modifications are inducible in adult organisms in relatively short time. Although the mechanisms responsible for such modifications still remain unidentified, these results confirm the need of further investigations to go deeper the possible consequences of GM food consumption
Fine distribution of CLOCK protein in hepatocytes of hibernating dormice.
No full textCLOCK protein is a member of the bHLH-PAS family of transcription factors, it is expressed in several tissues including the liver and is essential for normal circadian rhythms. In this study we investigate the distribution of CLOCK protein in hepatocytes of euthermic and hibernating edible dormice Glis glis as well as in hepatocytes taken from the hibernating animals submitted in vitro to experimental conditions mimicking the arousal process. Our results demonstrate that CLOCK protein is expressed in all animals and is mostly located in the nucleus, in particular, on perichromatin fibrils and nucleoli. During deep hibernation CLOCK protein becomes more abundant but an intracellular redistribution occurs: the protein significantly decreases in all cellular compartments, but it accumulates in the amorphous bodies. These nuclear bodies, typical of the hibernating state, probably represent storage sites for CLOCK protein to be quickly used upon arousal. Accordingly, in hepatocytes submitted to in vitro conditions mimicking arousal CLOCK protein levels rapidly reach the euthermic values, while amorphous bodies disappear
Immunolocalizzazione della proteina CLOCK negli epatociti di topo in varie fasi del ciclo circadiano
No full textImmunocytochemical analysis of the circadian clock protein in mouse hepatocytes
No full textMany biochemical, physiological, and behavioral processes in organisms ranging from prokaryotes to humans exhibit circadian rhythms, defined as cyclic oscillations of about 24 hours. The mechanism of the cellular circadian clock relies on interlocking positive and negative transcriptional/translational feedback loops based on the regulated expression of several genes. Clock is one of these genes and its transcript, CLOCK protein, is a transcription factor belonging to the bHLH-PAS family. In mammals the clock gene is expressed in several tissues, including the liver. In the present study, we analyzed by means of quali-quantitative immunoelectron microscopy the fine intracellular distribution of the CLOCK protein in mouse hepatocytes during the daily cycle. We demonstrated that CLOCK protein is mostly located in the cell nucleus, where it accumulates on perichromatin fibrils, representing the in situ form of nascent pre-mRNA, while condensed chromatin and nucleoli contain lower amounts of protein. Moreover, we found that CLOCK protein shows circadian oscillations in these nuclear compartments, peaking in late afternoon. At this time the hepatic transcriptional rate reaches the maximal level, thus suggesting an important role of CLOCK protein in the regulation of liver gene expression. © 2003 Wiley-Liss, Inc
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