ABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of crocetin on autophagy in rat hepatocytes exposed to lipopolysaccharide (LPS) and D-galactosamine (D-gal) and explore the mechanism.</p><p><b>METHODS</b>Cultured rat hepatocytes were exposed to LPS (1 mg/L) and Dgal (60 mg/L) to induce cell injury and treated with crocetin, 3MA, or crocetin+3MA. Twelve hours after the treatments, the cells were examined for levels of ALT, AST and LDH in the supernatant using ELISA. LC3 fluorescence in the cells following immunofluorescence staining was observed using fluorescence microscopy. Autophagosomes in the cells were observed by transmission electron microscopy, and the cellular expressions of LC3, p62 and SIRT1 were detected using Western blotting.</p><p><b>RESULTS</b>The levels of ALT, AST and LDH in the hepatocytes were elevated after LPS- and D-gal-induced injury, reached the highest levels after 3MA treatment, but were decreased significantly by crocetin treatment. LC3 fluorescence increased obviously in the injured hepatoctyes, and the increment was the most obvious in crocetin-treated cells; LC3 fluorescence was decreased significantly after 3MA treatment. Cell injury induced obvious increase in autophagy in the hepatocytes, and the number of autophagosomes increased significantly after crocetin treatment but was reduced significantly after 3MA treatment. The cell injury caused an obvious up-regulation of LC3 and SIRT1 expression and down-regulated p62 expression. LC3 and SIRT1 expression levels were the highest and the expression of p62 was the lowest in cells with crocetin treatment. 3MA treatment significantly reduced the expression of LC3 and SIRT1 and increased the expression of p62 in the injured cells.</p><p><b>CONCLUSIONS</b>Autophagy is increased in injured rat hepatocytes, and crocetin can promote autophagy in the injured cells to reduce further cell injury.</p>
ABSTRACT
Objective To study multiple-drug resistance expression of CNE1 and CNE2 cell lines induced by radiation and its reversal by cyclosporine A and interferon. Methods Drug-resistant CNE1 and CNE2 cell lines were induced by radiation, and expression of P-gp, MRP, TOPⅡ and GST-? on protein and mRNA level were analyzed by flow cytometry and reverse transcription-polymerase chain reaction methods before and after radiation. At the same time, effect of cyclosporine A and interferon on multiple-drug resistance expression induced by radiation was studied. Results The results showed that expression of P-gp, MRP and GST-? proteins on CNE1 and CNE2 cell lines were up-regulated by radiation, and cyclosporine A and interferon could reverse the up-regulation of P-gp and MRP proteins induced by radiation. Conclusion Radiation can induce multiple-drug resistance in CNE1 and CNE2 cell lines, and it can be reversed by cyclosporine A and interferon.
ABSTRACT
AIM To study effects of antioxidant NADH on damage of irradiated normal cell lines. METHODS L02 liver cells were cultured in RPMI 1640, exposed to X ray irradiation, and continued to culture in the presence or absence of NADH for 24 h. The cellular viability was determined by routine MTT method. Using fluorescence probe and confocal microscope, the level of cellular H 2O 2 was detected. Positive rate of bcl 2 and Bax protein expression in the L02 cells were analyzed by flow cytometry. RESULT NADH can not only antagonized growth inhibition of X ray irradiated L02 cells, decreased cellular H 2O 2 production, but also significantly increased positive rate of L02 cells expressed bcl 2 protein and decrease positive rate of L02 cells expressed Bax proteins ( P