The Effects Of Uric Acid On PC12Cells Against The Toxicity Induced By Rotenone

PART Ⅰ Protective effects of uric acid against rotenone-inducedcell injury in PC12cellsObjective: To investigate the effect of uric acid (UA) in injury induced by rotenone inPC12cells.Methods: The PC12cells were divided into4groups: the control, rotenone, UA andUA+rotenone. All cells were treated for24hours in vitro. Subsequently, the content ofLactate dehydrogenas (LDH) in culture medium was detected by colorimetric method, andcells apoptosis rate was detected with Hoechst33342and Annexin V-PI staining.Results:The release of LDH in the group treated with0.1-5μmol/L rotenone for24hwere significantly increased compared with the control group (267.33±44.79U/Lvs189.75±37.50U/L,303.04±34.01U/L vs189.75±37.50U/L,380.25±28.38U/Lvs189.75±37.50U/L,436.52±29.32U/L vs189.75±37.50U/L,500.19±32.36U/L vs189.75±37.50U/L,563.35±42.33U/L vs189.75±37.50U/L, P<0.05). However, therewas no difference on the levels of LDH, apoptosis cells between UA group and the controlgroup (P>0.05). While the release of LDH were decreased (367.02±15.71U/L vs464.43±20.26U/L,329.56±15.79U/L vs464.43±20.26U/L,299.65±26.37U/L vs464.43±20.26U/L,284.70±21.18U/L vs464.43±20.26U/L, P<0.05) in50-400μmol/L UA+1μmol/L rotenone group compared with1μmol/L rotenone group. The apoptosic cellswere decreased in200μmol/L UA+1μmol/L rotenone group compared with1μmol/Lrotenone group (P<0.05).Conclusions: Uric acid can prevent PC12cells from injury induced by rotenone. PARTⅡ The protective role of uric acid in the rotenone-mediated PC12cellsObjective: To investigate the effective of uric acid on the decrease of SOD, GSH,mitochondrial membrane potential and the release of cytochrome c induced by rotenone inPC12cells.Methods: The PC12cells were divided into4groups: the control (the DMSO group),rotenone (1μmol/L), UA (200μmol/L) and UA (200μmol/L)+rotenone (1μmol/L). Allcells were treated for24hours in vitro. The content of superoxide dismutase (SOD),glutathione (GSH), mitochondrial membrane potential and the release of cytochrome c inPC12cells were detected by colorimetric method, flow cytometer and Western blotanalysis.Results: The activity of SOD and GSH in PC12cells treated with1μmol/L rotenonefor24h were significantly decreased compared with the control group (10.40±0.76U/L vs20.62±0.37U/L，P<0.05;1.86±0.71μmol/g pro vs7.67±1.38μmol/g pro, P<0.05), thelevel of mitochondrial membrane potential was also decreased (0.66±0.03%vs1±0.06%，P<0.05). The release of cytochrome c from mitochondria into the cytosol wasincreased (0.74±0.14vs0.11±0.11, P<0.05). There was no difference on the levels ofSOD, GSH, mitochondrial membrane potential and the release of cytochrome c between200μmol/L UA group and the control group．While the activity of SOD and GSH wereincreased (17.40±0.28U/L vs10.40±0.76U/L, P<0.05;5.95±0.38μmol/g pro vs1.86±0.71μmol/g pro, P<0.05), also the level of mitochondrial membrane potential wasincreased (0.80±0.09%vs0.66±0.03%, P<0.05), and the release of cytochrome c frommitochondria into the cytosol was decreased (0.49±0.12vs0.74±0.14, P<0.05) in200μmol/L UA+1μmol/L rotenonegroup compared with1μmol/L rotenone group.Conclusion: These results suggest that uric acid prevented PC12cells from injuryinduced by rotenone, which may associated with the increased activity of SOD, GSHmitochondrial membrane potential and the decreased release of cytochrome c.