Abstract:

Objective To investigate the damage of hippocampal neuron cell line HT22 at different time points after oxygen and glucose deprivation/reoxygenation. Methods Logarithmic growth phase of HT22 cells was randomly divided into six groups, normal control group,OGD/R 0 hour, OGD/R 12 hours, OGD/R 24 hours, OGD/R 48 hours,OGD/R 72 hours groups. All groups were treated with reoxygenation after deprived of oxygen and glucose for 6 hours except normal group.The cell morphology was observed by invertded microscope. Cell counting kit-8(CCK-8) method was used to test the cell survival rate. Lactate dehydrogenase (LDH) method was used to detect cell damage. Bax and Bcl-2 immunofluorescence were used to detect apoptosis. Results HT22 cells in normal group were bipolar or multipolar. Obvious synapses and multiple synapses were woven into a network. Cell membrane was smooth and complete and the refractivity of cell was strong. But the axons decreased, cell was shrinkage and cytoplasmic aggregation in HT22 in OGD/R groups, and the cell viability was significantly reduced（P<0.05）, the lowest point appeared in OGD/R 12 hours to OGD/R 24 hours; OGD/R 12 hours and OGD/R 24 hours LDH increased significantly (P<0.05), OGD/R 0 hour, 48 hours, and 72 hours increased. The ratios of Bax/Bcl-2 in OGD/R groups were significantly increased (P<0.05) except for OGD/R 0 hour and OGD/R 72 hours, and peaked at OGD/R 24 hours. Conclusion Injury of cells afer OGD/R is a complex and dynamic process. Cell injury is aggravating as the reoxygenation time increased and reached a peak in OGD/R 24 hours, from then on, cell damage gradually decreased.

Key words: Oxygen and glucose deprivation/reoxygenation, Cell injury, Dynamic observation, Immunofluorescence, HT22 cell