Protective role and mechanism of orexin A in cell viability of Alzheimer’s disease cell model PC12

Abstract

Objective To study the role and mechanism of orexin A in cell viability of Alzheimer’s disease (AD) cell model PC12. Methods PC12 cells were treated with 0, 10, 20, 30, 40 and 50 μmol/L Aβ25-35 for 24 h, and then, cell viability was measured by MTT to confirm which concentration was the suitable one to establish the AD cell models. (1) AD cell models were treated with 0, 0.01, 0.1, 1 and 2 μmol/L orexin A for 24 h, and then, 30 μmol/L Aβ25-35 was added for 24 h; MTT assay was used to determine the cell viability to conform the suitable concentration of orexin A. (2) Inverted phase contrast microscope was employed to observe the morphology changes of PC12 cells from the control group, 30 μmol/L Aβ25-35 treatment group, and 0.01 μmol/L orexin A+30 μmol/L Aβ25-35 treatment group. (3) The PC12 cells were given pretreatment of orexin A receptor inhibitor SB408124 for 2 h, and cell viability was detected. Results (1) Aβ25-35 at concentration 30 μmol/L was the suitable one to establish the AD cell models; after being pretreated with different concentrations of orexin A, the cell viability showed significant differences (F=27.120, P=0.000), and 0.01 μmol/L orexin A was the suitable concentration. (2) Some of the cells from the 30 μmol/L Aβ25-35 treatment group had breaking-off of protuberance and damaged soma; cells from 0.01 μmol/L orexin A+30 μmol/L Aβ25-35 treatment group had breaking-off of protuberance, and the degree of damaged soma was eased as compared with that in the 30 μmol/L Aβ25-35 treatment group. (3) If the cell viability of the control group was 100%, cell viability of orexin A receptor inhibitor group was 109.10%±0.36%, which was significantly decreased as compared with that in the 0.01 μmol/L orexin A pretreated group (117.24%±2.72%, P<0.05). Conclusion Orexin A can improve the cell viability via combination of its specific receptor; orexin A and its specific receptor may be new targets for prevention and cure of AD. Key words: Orexin A; Alzheimer's disease; Cell viability