Silvana Spagnuolo

Learn More
Extranuclear or nongenomic effects of thyroid hormones are mediated by receptors located at the plasma membrane or inside cells, and are independent of protein synthesis. Recently the alphaVbeta3 integrin was identified as a cell membrane receptor for thyroid hormones, and a wide variety of nongenomic effects have now been shown to be induced through(More)
The molecular mechanism by which thyroid hormones exert their effects on cell growth is still unknown. In this study, we used chick embryo hepatocytes at different stages of development as a model to investigate the effect of the two thyroid hormones, T3 and T4, and of their metabolite T2, on the control of cell proliferation. We observed that T2 provokes(More)
In rats, various growth factors and hormones, as well as partial hepatectomy (PH) are able to trigger the proliferative response of hepatocytes. Although recent evidence highlights the important role of thyroid hormones and thyroid status in regulating the growth of liver cells in vitro and in vivo models, the mechanism involved in the pro-proliferative(More)
Transglutaminase (TG) activity is increased in the mucosa of patients with coeliac disease. Among 18 patients with untreated coeliac disease we have found a significant decrease (p less than 0.001) in serum levels of TG activity (0.72 (0.23) mU/ml). There was no significant differences between 16 treated coeliacs (1.24 (0.28) mU/ml) and 30 normal controls(More)
Nongenomic effects of thyroid hormones on Na+-K+-ATPase activity were studied in chick embryo hepatocytes at two different developmental stages, 14 and 19 days of embryonal age, and the signal transduction pathways involved were characterized. Our data showed the following. 1) 3,5,3'-Triiodo-L-thyronine (T3) and 3,5-diiodo-L-thyronine (3,5-T2) rapidly(More)
Liver proliferation occurs in the presence of mitogenic stimuli such as partial hepatectomy or growth factors. In this work we investigate how partial hepatectomy and Epidermal Growth Factor (EGF) affect hepatocyte proliferation by modulating cell cycle regulators. EGF administered to non-operated rats increased PCNA (proliferating cell nuclear antigen)(More)
Acyl coenzyme A : cholesterol acyltransferase (ACAT), the enzyme catalyzing the hepatic cholesterol esterification, could be involved in the modified availability of cholesterol detectable in proliferating systems. While no significant variations are detectable in the regenerating liver, the modified ACAT activity during liver development and its(More)
The binding and uptake of cholesterol enriched lipoproteins by isolated hepatocytes was decreased at 16 hours after partial hepatectomy, with a tendency to return to control values as the regeneration proceeds. The number of lipoprotein binding sites of total cellular membranes remained similar to control at 16 and 24 hours. The plasma lipoprotein pattern,(More)
During pregnancy the synthesis of cholesterol and the activity of 3-hydroxy 3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase fell markedly before parturition; HMGCoA synthase activity was low during pregnancy and fell again immediately before delivery while acetoacetyl-CoA-thiolase was always low and constant.
The relationship between cell proliferation and inositol lipid turnover has been studied by comparing the steady state of inositol derivative metabolism in quiescent and regenerating rat hepatocytes isolated at 4 h (G1 phase of first cell cycle) and 24 h (onset of M phase) after partial hepatectomy. The effect of two hormones able to regulate hepatic(More)