Objective: To explore the correlation between the elevated expression of cytokines under the induction of Poly(I:C) (polycytidylic acid) in maternal hosts and the abnormal behaviors of adult offsprings and understand the intervening effects of nuclear factor NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC).
Methods: Poly(I:C) or saline was administered to model the maternal infection during early pregnancy in rats. And the expression of cytokines was blocked with PDTC. The maternal levels of tumor necrosis factor alpha and interleukin-10 were determined by ELISA (enzyme-linked immunosorbent assay). The adult offsprings on different treatments were then compared with regards to prepulse inhibition (PPI), passive avoidance and active avoidance.
Results: After the administration of Poly(I:C), there was an elevated levels of serum cytokines as shown by the markedly increased serum levels of IL-10 and TNF-α. The serum levels of IL-10 and TNF-α in the model group were significantly higher than those in the control group [(18.26 ± 1.52) pg/ml, (119.64 ± 16.42) pg/ml vs. (0.16 ± 0.13) pg/ml and (11.21 ± 1.81) pg/ml]. The elevation was partly blocked by PDTC. The serum levels of IL-10 and TNF-α in the intervention group [(12.64 ± 2.04) pg/ml and (30.34 ± 2.19) pg/ml respectively] were lower than those in the model group, but still higher than those in the control group. The psychotic-like phenotypes including defects in PPI, passive avoidance and active avoidance were observed in Poly(I:C)-treated offsprings. Such an effect was blunted by the PDTC intervention. The PPI results demonstrated that the PP₂ and PP₈ difference between rats in 3 groups were statistically significant, with a lower PPI value in the model group than in the intervention group, in the intervention group than in the control group and much lower in the model group than in the control group. PP4 was lower in the model group than that in the intervention group, and also lower in the model group than in the control group. There was no significant difference between the control group and the intervention group. The passive avoidance results indicated that T1 was higher in the model group than in the control and intervention groups and there was no statistical difference between the control and intervention groups. T2 was lower in the model group than in the control and intervention groups and there was no statistical difference between the control and intervention groups. And the active avoidance test results showed that total conditioned reflex times of the control group was higher than those of the intervention and model groups. No statistical difference was found between the intervention and model groups. Total reflex rate of the control group was higher than that of the intervention and model groups. No statistical difference was found between the intervention and model groups.
Conclusion: PDTC can interfere with neural developmental disorder of adult offsprings through blunting the cytokine-mediated maternal immune response.