Effects of hyperbaric oxygen on the activation of β-catenin in hypoxic ischemic neonate rats / 中华物理医学与康复杂志

ABSTRACT

Objective To explore the relationship between the proliferation of neural stem cells (NSCs)and the expression of β-catenin protein in neonate rats with hypoxic ischemic brain damage (HIBD) after hyperbaric oxygen (HBO) therapy. Methods One hundred and eighty Sprague-Dawley rats aged 7 days were randomly divided into a normal control group (CON) , a HIBD model group and a HBO treatment group. The HIBD model was induced using Rice's method. Beginning 3h after the HIBD, HBO was administered to the HBO treatment group at 2 atmospheres for 60 min, once daily for 7 days. The HIBD model group was not given any treatment. The expression of nestin/β-catenin protein in the subventricular zone of the ischemic brain was double-stained for immunofluorescence and analyzed by confocal scanning microscopy dynamically at 3 hours, 21 hours, and then on the 3rd, 5th, 7th and 14th day of HBO therapy. The expression of whole cell β-catenin and nuclear β-catenin protein in the left brain were also examined by Western blotting at these 6 time points. Linear correlation was used to analyze the correlation between β-catenin and nestin protein. Results The expression of β-catenin protein in NSCs increased initially at the 21st hour after HBO therapy in the model group and the HBO group as compared with the normal control group.β-catenin protein in the model group reached a higher level, though there was no significant difference between model group and the HBO group. At the 5th day of HBO therapy β-catenin protein in the HBO group had reached a significantly higher level than in the model group. At the 14th day the average expression of β-catenin in the HBO group began to decrease. The expression of nestin protein began to increase 21 hours after HBO therapy began, and it peaked at the 7th day of HBO therapy and then decreased. In the HBO group the increase in nestin protein was linearly correlated with that of β-catenin protein. The whole cell β-catenin protein and β-catenin nucleic protein readings increased initially by the 21st hour of HBO therapy and by the 5th day were significantly higher than the levels in the model group. Conclusion HBO treatment is capable of stimulating the proliferation of NSCs in HIBD neonate rats.The proliferation of NSCs is correlated with the activation of β-catenin protein.