Effect of dexamethasone on the expression of Dynein heavy chain and Dynactin in the cytoplasm of fetal rat cerebral cortical neurons cultured in vitro

OBJECTIVE To study the effect of dexamethasone (DEX) on the expression of Dynein heavy chain (DHC) and Dynactin in the cytoplasm of fetal rat cerebral cortical neurons cultured in vitro. METHODS Primary cerebral cortical neurons of fetal rats were cultured in vitro and were used to establish a cellular model of DEX intervention. According to the final concentration of DEX, the neurons were divided into three groups:control (without DEX), 0.1 μmol/L DEX, and 1.0 μmol/L DEX. On days 1, 3, and 7 after intervention, the quantitative PCR was used to observe the effect of DEX on the mRNA expression of DHC and Dynactin. The Western blot was used to observe the effect of DEX on the protein expression of DHC and Dynactin. RESULTS There was no significant difference in the mRNA expression levels of DHC and Dynactin among the three groups at all time points (P > 0.05). On day 7 after DEX intervention, the protein expression of DHC in the 1.0 μmol/L DEX group gradually increased and reached the peak over time, which was significantly higher than that in the control and 0.1 μmol/L DEX groups (P < 0.05). The control and 0.1 μmol/L DEX groups had a significant increase in the protein expression of Dynactin from day 1 to days 3 and 7 after DEX intervention (P < 0.05). The control group had a significant increase in the protein expression of Dynactin from day 3 to day 7 after intervention (P < 0.05), while the 0.1 μmol/L DEX group had a significant reduction in the protein expression of Dynactin from day 3 to day 7 after intervention (P < 0.05). On days 3 and 7 after DEX intervention, the 0.1 μmol/L DEX and 1.0 μmol/L DEX groups had a significantly lower protein expression level of Dynactin in the cerebral cortical neurons than the control group (P < 0.05). On day 7 after DEX intervention, the 1.0 μmol/L DEX group had a significantly lower protein expression level of Dynactin than the 0.1 μmol/L DEX group (P < 0.05). CONCLUSIONS DEX affects the protein expression of DHC and Dynactin in the fetal rat cerebral cortical neurons cultured in vitro, possibly in a concentration- and time-dependent manner.