Inhibitory Effect of CCK-8 on Methamphetamine-Induced Apoptosis.

Objectives: To investigate the inhibitory effect of cholecystokinin octapeptide (CCK-8) binding to cholecystokinin 2 receptor (CCK2R) on methamphetamine (METH)-induced neuronal apoptosis, and to explore the signal transduction mechanism of β-arrestin 2 in CCK-8 inhibiting METH-induced neuronal apoptosis.
Methods: SH-SY5Y cell line was cultured, and HEK293-CCK1R and HEK293-CCK2R cell line were constructed by lentivirus transfection. Small interfering RNA (siRNA) was used to knockdown the expression of β-arrestin 2. Annexin Ⅴ-FITC/PI staining and flow cytometry were used to detect the apoptotic rate of cells, and Western blotting was used to detect the expression of apoptosis-related proteins.
Results: The apoptosis of SH-SY5Y cells was induced by 1 mmol/L and 2 mmol/L METH treatment, the number of nuclear fragmentation and pyknotic cells was significantly increased, and the expression of apoptosis-related proteins Bax and cleaved caspase-3 were increased. CCK-8 pre-treatment at the dose of 0.1 mmol/L and 1 mmol/L significantly reversed METH-induced apoptosis in SH-SY5Y cells, and inhibited cell nuclear fragmentation, pyknosis and the changes of apoptosis-related proteins induced by METH. In lentivirus transfected HEK293-CCK1R and HEK293-CCK2R cells, the results revealed that CCK-8 had no significant effect on METH-induced changes of apoptosis-related proteins in HEK293-CCK1R cells, but it could inhibit the expression level of apoptosis-related proteins in HEK293-CCK2R cells induced by METH. The inhibitory effect of CCK-8 on METH-induced apoptosis was blocked by the knockdown of β-arrestin 2 expression in SH-SY5Y cells.
Conclusions: CCK-8 can bind to CCK2R and exert an inhibitory effect on METH-induced apoptosis by activating the β-arrestin 2 signal.