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22. Cholesterol induces fetal rat enterocyte death in culture

Author

Gazzola J., Silva É.P.P., Kanunfre C.C., Verlengia R., Vecchia M.G., and Curi R.

Subjects
Fetal enterocytes, Cholesterol, Intestine, IEC-6 cells, HMG-CoA, PPARgamma, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

The effect of cholesterol on fetal rat enterocytes and IEC-6 cells (line originated from normal rat small intestine) was examined. Both cells were cultured in the presence of 20 to 80 µM cholesterol for up to 72 h. Apoptosis was determined by flow cytometric analysis and fluorescence microscopy. The expression of HMG-CoA reductase and peroxisome proliferator-activated receptor gamma (PPARgamma) was measured by RT-PCR. The addition of 20 µM cholesterol reduced enterocyte proliferation as early as 6 h of culture. Reduction of enterocyte proliferation by 28 and 41% was observed after 24 h of culture in the presence and absence of 10% fetal calf serum, respectively, with the effect lasting up to 72 h. Treatment of IEC-6 cells with cholesterol for 24 h raised the proportion of cells with fragmented DNA by 9.7% at 40 µM and by 20.8% at 80 µM. When the culture period was extended to 48 h, the effect of cholesterol was still more pronounced, with the percent of cells with fragmented DNA reaching 53.5% for 40 µM and 84.3% for 80 µM. Chromatin condensation of IEC-6 cells was observed after treatment with cholesterol even at 20 µM. Cholesterol did not affect HMG-CoA reductase expression. A dose-dependent increase in PPARgamma expression in fetal rat enterocytes was observed. The expression of PPAR-gamma was raised by 7- and 40-fold, in the presence and absence of fetal calf serum, respectively, with cholesterol at 80 mM. The apoptotic effect of cholesterol on enterocytes was possibly due to an increase in PPARgamma expression.

Published
2004

24. Glutamine and glutamate as vital metabolites

Author

Newsholme P., Lima M.M.R., Procopio J., Pithon-Curi T.C., Doi S.Q., Bazotte R.B., and Curi R.

Subjects
Glutamine, Glutamate, Glucose, Metabolism, Cell function, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

Glucose is widely accepted as the primary nutrient for the maintenance and promotion of cell function. This metabolite leads to production of ATP, NADPH and precursors for the synthesis of macromolecules such as nucleic acids and phospholipids. We propose that, in addition to glucose, the 5-carbon amino acids glutamine and glutamate should be considered to be equally important for maintenance and promotion of cell function. The functions of glutamine/glutamate are many, i.e., they are substrates for protein synthesis, anabolic precursors for muscle growth, they regulate acid-base balance in the kidney, they are substrates for ureagenesis in the liver and for hepatic and renal gluconeogenesis, they act as an oxidative fuel for the intestine and cells of the immune system, provide inter-organ nitrogen transport, and act as precursors of neurotransmitter synthesis, of nucleotide and nucleic acid synthesis and of glutathione production. Many of these functions are interrelated with glucose metabolism. The specialized aspects of glutamine/glutamate metabolism of different glutamine-utilizing cells are discussed in the context of glucose requirements and cell function.

Published
2003

26. Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

Author

Azevedo R.B., Lacava Z.G.M., Miyasaka C.K., Chaves S.B., and Curi R.

Subjects
antioxidant enzymes, macrophages, sex hormones, estrogen, progesterone, castration, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%). Removal of the gonads in both males and females (comparison between castrated groups) increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48%) CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

Published
2001

39. Contributor contact details

Author

Calder, Philip C., primary, Yaqoob, Parveen, additional, Noakes, Paul S., additional, Michaelis, Louise J., additional, Brandtzaeg, Per, additional, Kilic, A., additional, Kesper, D.A., additional, Pfefferle, P.I., additional, Renz, H., additional, Margioris, A.N., additional, Dermitzaki, E., additional, Venihaki, M., additional, Tsatsanis, C., additional, Gruber, K., additional, Rink, Lothar, additional, Hoffmann, P.R., additional, Huang, Z., additional, Kuvibidila, Solo R., additional, Baliga, Surendra B., additional, Chandra, Lawrance C., additional, French, Christine L., additional, Ross, A. Catharine, additional, Restori, Katherine H., additional, Harvey, Nicholas C., additional, Cantorna, Margherita T., additional, Trejo, Fernando, additional, Sanz, Yolanda, additional, Guarner, Francisco, additional, Moughan, Paul J., additional, Rutherfurd-Markwick, Kay, additional, Rueda, Ricardo, additional, Watzl, Bernhard, additional, Ioannone, Francesca, additional, Miglio, Cristiana, additional, Raguzzini, Anna, additional, Serafini, Mauro, additional, Morabito, Giuseppa, additional, Savelkoul, H.F.J., additional, Chanput, Wasaporn, additional, Wichers, Harry J., additional, Vinolo, M.A.R., additional, Rodrigues, H.G., additional, Nachbar, R.T., additional, Curi, R., additional, Calder, Philip C., additional, Roth, Erich, additional, Wu, Guoyao, additional, Grimble, George K., additional, Miles, Elizabeth A., additional, Moore, Sophie E., additional, Müller, Ludmila, additional, Pawelec, Graham, additional, Derhovanessian, Evelyna, additional, Gleeson, Michael, additional, and Solomons, Noel, additional

Published
2013
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