Protective Effect Of Liver Phosphatidylcholine And Caveolin-1

Phospholipid is an essential component of cell membrane. Phospholipid uptake can improve membrane fluidity and enzyme activity. Caveolin-1 is a mainly functional protein in Caveolae, and plays an important role in signal transduction. The added phospholipids promote the formation and transition of Caveolin-1vesicles. It is essential for Caveolae formation and the synthesis of new membranes. Our previous study showed that, phosphatidylcholine (PC) is rich in allyl ether which plays an important role in antioxidant activity protection. Moreover, phospholipid can promote the expression of Caveolin-1. But the mechanism is not entirely clear.Caveolin-1 down-regulated cell line was obtained by siRNA interference with Chang liver cells, and alcohol-injury model was established in order to investigate the role of Caveolin-1 in cell repair. We detected the electrical conductivity and the composition of membrane phospholipid in Chang liver cell and Caveolin-1 down-regulated cells which were alcohol-induced. Western blot analysis was used to detect the expression of Caveolin-1 or oxidative stress-related proteins in Chang liver cells which were pre-protected by PC, further investigated the role of Caveolin-1 in cell repair and the protective mechanism of PC.Results:1. Chang liver cells incubated with alcohol induced oxidative stress, leading to the level of superoxide dismutase (SOD) reduced (P<0.05) and the expression of TLR4, TNF-α, NF-κB, p-P38 increased. However, pre-protected by liver Phosphatidylcholine increases the SOD activity (P<0.05) in Chang liver cells and reduce TLR4, TNF-α, NF-κB, P-p38 expression.2. Caveolin-1 down-regulated cell line was obtained by siRNA interference with Chang liver cells. The release of ALT increased in Caveolin-1 down-regulated cells which were incubated with different alcohol concentrations. And the changes of cell electrical conductivity (P<0.05) and membrane phospholipid composition were significant in Caveolin-1 down-regulated cells.3. Added PC could increase the level of Caveolin-1 and PKCα.Conclusion: Liver-derived phospholipids significantly protected the membrane lipid peroxidation caused by alcohol-injury, and the mechanism was closely correlated with the expression of Caveolin-1. Caveolin-1 gene silencing induced the sensitivity increased which incubated with alcohol. The protective effect of liver phospholipid is regulated by phospholipid-PKCαsignaling which involved the role of Cavolin-1.