611 research outputs found
Action of Thyroid Hormones, T3 and T2, on Hepatic Fatty Acids: Differences in Metabolic Effects and Molecular Mechanisms
No full textThe thyroid hormones (THs) 3,3',5,5'-tetraiodo-l-thyronine (T4) and 3,5,3'-triiodo-l-thyronine (T3) influence many metabolic pathways. The major physiological function of THs is to sustain basal energy expenditure, by acting primarily on carbohydrate and lipid catabolism. Beyond the mobilization and degradation of lipids, at the hepatic level THs stimulate the de novo fatty acid synthesis (de novo lipogenesis, DNL), through both the modulation of gene expression and the rapid activation of cell signalling pathways. 3,5-Diiodo-l-thyronine (T2), previously considered only a T3 catabolite, has been shown to mimic some of T3 effects on lipid catabolism. However, T2 action is more rapid than that of T3, and seems to be independent of protein synthesis. An inhibitory effect on DNL has been documented for T2. Here, we give an overview of the mechanisms of THs action on liver fatty acid metabolism, focusing on the different effects exerted by T2 and T3 on the regulation of the DNL. The inhibitory action on DNL exerted by T2 makes this compound a potential and attractive drug for the treatment of some metabolic diseases and cancer
3,5,3'TRIIODO-L-THYRONINE INDUCES SREBP-1 EXPRESSION BY NON-GENOMIC ACTIONS IN HUMAN HEP G2 CELLS
No full textLiver is an important target for thyroid hormone actions. T(3) exerts its effects by two mechanisms: (i) Genomic actions consisting of T(3) link to nuclear receptors that bind responsive elements in the promoter of target genes, (ii) non-genomic actions including integrin αvb3 receptor-mediated MAPK/ERK and PI3K/Akt/mTOR-C1 activation. SREBP-1a, SREBP-1c, and SREBP-2 are transcription factors involved in the regulation of lipogenic genes. We show in Hep G2 cells that T(3) determined a dose- and time-dependent increase in the level of the precursor form of SREBP-1 without affecting SREBP-1 mRNA abundance. T(3) also induced phosphorylation of ERK1/2, Akt and of mTOR-C1 target S6K-P70, and the cytosol-to-membrane translocation of PKC-α. Modulation of SREBP-1 protein level by T(3) was dependent on MAPK/ERK, PI3K/Akt/mTOR-C1 pathway activation since the MEK inhibitor PD98059 or the PI3K inhibitor LY294002 abolished the stimulatory effect of T(3) . Conversely, the effect of T(3) on SREBP-1 level was enhanced by using rapamycin, mTOR-C1 inhibitor. These data suggest a negative control of mTOR-C1 target S6K-P70 on PI3K/Akt pathway. The effect of T(3) on SREBP-1 content increased also by using PKC inhibitors. These inhibitors increased the action of T(3) on Akt phosphorylation suggesting that conventional PKCs may work as negative regulators of the T(3) -dependent SREBP-1 increase. T(3) effects were partially abrogated by tetrac, an inhibitor of the T(3) -αvβ3 receptor interaction and partially evoked by T(3) analog T(3) -agarose. These findings support a model in which T(3) activates intracellular signaling pathways which may be involved in the increment of SREBP-1 level through an IRES-mediated translation mechanism
The Pottesman Collection in the British Museum. Early Dynastic and Sargonic administrative texts. With an Appendix on a Palmyrene Inscription
No full textEdizione, trascrizione, traduzione e commento di un frammento di iscrizione palmirena inedita presente nella collezione Pottesman del British Museum (Appendice Agostini).The British Museum houses a small collection of six cuneiform tablets and a Palmyrene dedicatory inscription purchased in 1987 from the private collection of Solomon Pottesman. The aim of the present contribution is to provide a catalog of this lot and an edition of the so far unpublished cuneiform texts. In the appendix, Alessio Agostini added the edition of the Palmyrene inscription, which would have otherwise gone beyond the capabilities of the present author
Recensione di Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
No full textReview of Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
Author: Alessio MagogaRecensione di Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
Autor: Alessio Magog
Lipid accumulation stimulates the cap-independent translation of SREBP-1a mRNA by promoting hnRNP A1 binding to its 5'-UTR in a cellular model of hepatic steatosis
No full textNon-alcoholic fatty liver disease (NAFLD) is a chronic disease characterized by accumulation of lipid droplets in hepatocytes. Enhanced release of non-esterified fatty acids from adipose tissue accounts for a remarkable fraction of accumulated lipids. However, the de novo lipogenesis (DNL) is also implicated in the etiology of the NAFLD. Sterol Regulatory Element-Binding Protein-1 (SREBP-1) is a transcription factor modulating the expression of several lipogenic enzymes. In the present study, in order to investigate the effect of lipid droplet accumulation on DNL, we used a cellular model of steatosis represented by HepG2 cells cultured in a medium supplemented with free oleic and palmitic fatty acids (FFAs). We report that FFA supplementation induces the expression of genes coding for enzymes involved in the DNL as well as for the transcription factor SREBP-1a. The SREBP-1a mRNA translation, dependent on an internal ribosome entry site (IRES), and the SREBP-1a proteolytic cleavage are activated by FFAs. Furthermore, FFA treatment enhances the expression and the nucleus-cytosolic shuttling of hnRNP A1, a trans-activating factor of SREBP-1a IRES. The binding of hnRNP A1 to the SREBP-1a IRES is also increased upon FFA supplementation. The relocation of hnRNP A1 and the consequent increase of SREBP-1a translation are dependent on the p38 MAPK signal pathway, which is activated by FFAs. By RNA interference approach, we demonstrate that hnRNP A1 is implicated in the FFA-induced expression of SREBP-1a and of its target genes as well as in the lipid accumulation in cells
Handheld-Impedance-Measurement System with seven-decade capability and potentiostatic function
No full textThis paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 kΩ to 100 GΩ. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligibl
Mechanical and Biological Properties of Magnesium- and Silicon-Substituted Hydroxyapatite Scaffolds
No full textMagnesium (Mg)- and silicon (Si)-substituted hydroxyapatite (HA) scaffolds were synthesized using the sponge replica method. The influence of Mg2+ and SiO44− ion substitution on the microstructural, mechanical and biological properties of HA scaffolds was evaluated. All synthesized scaffolds exhibited porosity >92%, with interconnected pores and pore sizes ranging between 200 and 800 μm. X-ray diffraction analysis showed that β-TCP was formed in the case of Mg substitution. X-ray fluorescence mapping showed a homogeneous distribution of Mg and Si ions in the respective scaffolds. Compared to the pure HA scaffold, a reduced grain size was observed in the Mg- and Si-substituted scaffolds, which greatly influenced the mechanical properties of the scaffolds. Mechanical tests revealed better performance in HA-Mg (0.44 ± 0.05 MPa), HA-Si (0.64 ± 0.02 MPa) and HA-MgSi (0.53 ± 0.01 MPa) samples compared to pure HA (0.2 ± 0.01 MPa). During biodegradability tests in Tris-HCl, slight weight loss and a substantial reduction in mechanical performances of the scaffolds were observed. Cell proliferation determined by the MTT assay using hBMSC showed that all scaffolds were biocompatible, and the HA-MgSi scaffold seemed the most effective for cell adhesion and proliferation. Furthermore, ALP activity and osteogenic marker expression analysis revealed the ability of HA-Si and HA-MgSi scaffolds to promote osteoblast differentiation
El Tlacuache Núm. 16 (2001). 16 Año 1 (2001) octubre. El Tlacuache
No full text- ¿Entre la Guerra Santa y la Cruzada? por Aníbal Quijano. - Nuestro patrimonio desconocido por Teresita Loera y Anaite Monterforte. - El Yahutli por Margarita Avilés y Macrina Fuentes. - Haciendas por Carlos Fernando Alessio Robles
El Tlacuache Núm. 19 (2001). 19 Año 1 (2001) noviembre. El Tlacuache
No full text- Patrimonio cultural y monumento histórico: Tlayacapan un monasterio Agustino por Carlos Alessio Robles. - Nuestro patrimonio desconocido por Teresita Loera y Anaite Monterforte. - El Yauhtli por Margarita Avilés y Macrina Fuentes. - ¿Entre la Guerra Santa y la Cruzada? por Aníbal Quijano
Il GEIE "italiano" tra impresa e società
No full textA quasi trent’anni dall’emanazione del Regolamento comunitario 2137/1985 che ne segna la data di nascita, e a venticinque dalla effettiva possibilità di costituzione, il gruppo europeo di interesse economico (GEIE) è ancora percepito, nella migliore delle ipotesi, come una specie di “oggetto misterioso” nel panorama giuridico italiano ed europeo. Lo scopo di questo studio, che ha beneficiato del sostegno economico della Commissione Europea e della Provincia autonoma di Trento nell’ambito del Settimo Programma Quadro, Azione Marie Curie COFUND, progetto “TRENTINO”, è di tentare una riconduzione ragionata del GEIE a categorie che siano di maggiore familiarità per il giurista italiano, indagandone le problematiche principali (su tutte l’assenza del beneficio della responsabilità limitata dei membri per le obbligazioni assunte dal gruppo) ed offrendo ipotesi di soluzione
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