Natural glucocorticoid hydrocortisone was suggested as a potent substitution for dexamethasone in the treatment of bronchopulmonary dysplasia in neonates. The aim of this study was to investigate whether hydrocortisone is able to affect the expression of apoptotic genes and the intensity of naturally occurring cell death in the developing rat hippocampus. Hormone treatment decreased procaspase-3 and active caspase-3 levels as well as DNA fragmentation intensity in the hippocampal formation of one-week-old rats in 6 h after injection. These changes were accompanied by an upregulation of antiapoptotic protein Bcl-XL, while expression of proapoptotic protein Bax remained unchanged. The action of hydrocortisone was glucocorticoid receptor-independent, as the selective glucocorticoid receptor agonist dexamethasone did not affect either apoptotic protein levels or DNA fragmentation intensity in the hippocampal region. The data are the first evidences for in vivo antiapoptotic effects of hydrocortisone in the developing hippocampus., P. N. Menshanov, ... [et al.]., and Obsahuje seznam literatury
Monosodium glutamate (MSG), the sodium salt of glutamate, is commonly used as a flavor enhancer in modern nutrition. Recent studies have shown th e existence of glutamate receptors on lymphocytes, thymoc ytes and thymic stromal cells. In this study, we evaluated the in vitro effect of different MSG concentr ations on rat thymocyte apoptosis and expression of two apoptosis-related proteins, Bcl-2 and Bax. Rat thymocytes, obtained from male Wistar rats, were exposed to increasing concentrations of MSG (ranging from 1 mM to 100 mM) for 24 h. Apoptosis was detected using the Annexin V-FITC/PI apoptosis detection kit and cells were analyzed using a flow cytometer. Expression of Bcl-2 and Bax proteins were determined with flow cytometry using respective monoclonal antibodies. Exposure to MSG resulted in a dose-dependent decrease in cell survival (as determined by trypan blue exclusion method). Annexin V- FITC/PI also confirmed that MSG incr eased, in a dose-dependent manner, ap optotic cell death in rat thymocyte cultures. MSG treatment induced downregulation of Bcl-2 protein, while Bax protein levels were not significantly changed. Our data showed that MSG significantly modulates thymocyte apoptosis rate in cultures. The temporal profile of Bcl-2 and Bax expression after MSG treatment suggests that downregulation of Bcl-2 protein and the resulting change of Bcl-2/Bax protein ratio may be an important event in thymocyte apoptosis triggered by MSG., V. Pavlović, S. Cekić, G. Kocić, D. Sokolović, V. Živković., and Obsahuje bibliografii a bibliografické odkazy
The aim of our in vitro studies was to understand the role of leptin in controlling proliferation, apoptosis, and protein kinase A (PKA) in human ovarian cells. We analyzed the in vitro effects of leptin (0, 1, 10 or 100 ng/ml) on the accumulation of proliferation-related peptides (PCNA, cyclin B1), apoptosis-associated peptide (Bax) and the intracellular signaling molecule PKA in cultured human granulosa cells using immunocytochemistry and Western immunoblotting. It was observed that leptin stimulated in a dose-dependent manner the accumulation of PCNA (at doses 1-100 ng/ml), cyclin B1 (at doses 10 or 100 ng/ml), Bax (at doses 10 or 100 ng/ml) and PKA (at doses 1-100 ng/ml) in cultured human ovarian cells. These observations suggest the ability of leptin to control directly human ovarian cell functions: proliferation, apoptosis, and intracellular messenger PKA., A. V. Sirotkin, M. Mlynček, A. V. Makarevich, I. Florkovičová, L. Hetényi., and Obsahuje bibliografii a bibliografické odkazy