The Protective Effect of Olanzapine on the Hippocampal Neuron of Depression Model Rats via Inhibiting NLRP3 Inflammasome Activation

  Objective  To determine the impact olanzapine (OLA) on the hippocampal neuron of model rats with depression.

  Methods  Rats were divided into five groups: control, chronic unpredicted stress (CUS), OAL (0.5, 1, 2 mg/kg), si-Atg5, and OAL (2 mg/kg)+si-Atg5. Open field and sucrose preference tests were performed to evaluate rat behaviors. Cell apoptosis was detected with Tunnel. The concentrations of interleukin (IL)-1β and IL-18 were determined by ELISA. The expressions of cleaved Caspase-3, cleaved Caspase-9, LC3, Beclin1, P62, NLRP3 and cleaved Caspase-1 were measured by Western blot.

  Results  OAL (0.5, 1, 2 mg/kg) increased the total moving distance, sucrose consumption and preference rate of CUS rats, and decreased serum IL-18, cell apoptosis and the expressions of cleaved Caspase-9, cleaved Caspase-1 and NLRP3 in the CA3 region of hippocampus. Although OAL (1, 2 mg/kg) decreased the expression of cleaved Caspase-3 and serum IL-1β, OAL (0.5 mg/kg) showed no detectable effects. Si-Atg5 decreased the total moving distance, sucrose consumption and preference rate of CUS rats, enhanced the expressions of cleaved Caspase-3, cleaved Caspase-9, cleaved Caspase-1 and NLRP3, and weakened the effect of OAL (2 mg/kg). OAL (0.5, 1, 2 mg/kg) also increased the LC3Ⅱ/LC3Ⅰ ratio and the expression of Beclin1 in the CA3 region of hippocampus. OAL (1, 2 mg/kg) reduced the expression of p62, but not when it was reduced to 0.5 mg/kg. Si-Atg5 reduced the LC3Ⅱ/LC3Ⅰ ratio and the expression of Beclin1, and weakened the function of OAL (2 mg/kg).

  Conclusion  OAL can protect the hippocampal neuron of CUS rats via inhibiting NLRP3 inflammasome activation.