ABSTRACT
Objective:To explore the effects of early-life maternal deprivation on depressive-like behavior and neurogenesis in the granular layer of hippocampus in adolescent rats (6-7 weeks old).Methods:Neonatal rats were randomly divided into maternal deprivation group and control group, with 3 litters in each group.Rats in the maternal deprivation group were given maternal deprivation from 1 to 14 days after birth and rats in the control group were caged with the mother rats and raised normally.The body weight of rats at 5-6 weeks old was recorded and the increased body weight was calculated.When the rats were 6 weeks old, the sucrose preference test was carried out.Then the rats were killed and immunofluorescence histochemistry was applied to compare the expression of Ki67 and Nestin positive cells in the dentate gyrus of hippocampus.SPSS 22.0 software was used for statistical analysis.The data of the two groups were tested to conform to the normal distribution, and then t-test was carried out. Results:There was significant difference in body weight growth between the two groups at the age of 5-6 weeks.Compared with the control group, rats in the maternal deprivation group had lower body weight growth ((20.57±2.19) g, (30.57±1.25) g, t=3.96, P<0.01)) and lower sucrose preference rate((58.38±53.14)%, (73.88±3.67)%, t=3.21, P<0.01). The results of immunofluorescence showed that the number of Ki67 positive cells in the granular layer of hippocampus in the maternal deprivation group was less than that in the control group ((5.13±0.31), (7.60±0.38), t=5.09, P<0.01), and the number of Nestin immunofluorescence positive cells was more than that in the control group ((16.65±0.79), (7.64±0.70), t=8.51, P<0.01). The Nestin immunofluorescence positive cells in the maternal deprivation group had more protrusions and branches, and the morphology was similar to astrocytes, while the immunofluorescence positive cells in the control group had fewer protrusions, and the cell body was oval. Conclusions:Early-life maternal deprivation leads to depressive-like behavior in adolescent rats, which may be associated with the decrease of neurogenesis and activation of astrocytes in the dentate gyrus of the hippocampus.
ABSTRACT
Objective To evaluate regulatory effects of glutamate receptor antagonists on the proliferation and migration of WM451LU malignant melanoma cells, and to explore their related mechanisms. Methods WM451LU cells at exponential growth phase were classified into 3 groups to be treated with the glutamate receptor antagonist MK?801 at 100μmol/L(MK?801 group), the glutamate receptor antagonist CPCCOEt at 10μmol/L(CPCCOEt group), or culture medium(control group). After 24?hour treatment, methyl thiazolyl tetrazolium(MTT)assay was performed to determine cell proliferation rates, scratch assay to evaluate the migration activity of cells, and Western?blot analysis to measure expression levels of proliferating cell nuclear antigen (PCNA), protein kinase Cα(PKCα) both on cell membrane and in cytoplasm, and phosphorylated mitogen?activated protein kinase(p?MAPK). Results After 24?hour treatment, cell proliferation rates were significantly decreased in the MK?801 group and CPCCOEt group compared with the control group(63%± 3.1%and 60%± 2.4%vs. 100%± 1.1%, both P<0.05). The scratch assay showed that cell?free zones in the control group gradually narrowed over time, and the scratch wound tended to close. However, the cell?free zones in the MK?801 group and CPCCOEt group narrowed more slowly compared with the control group, and were still wide after 24?hour culture with no obvious closure of the scratch. The MK?801 group and CPCCOEt group both showed significantly decreased expressions of PCNA(77.0% ± 5.4% and 72.0% ± 4.2% respectively), PKCα on the cell membrane(0.12 ± 0.02 and 0.14 ± 0.02 respectively), and p?MAPK(0.48 ± 0.03 and 0.36 ± 0.04 respectively) compared with the control group(PCNA:100.0%± 1.3%;PKCα:0.38 ± 0.01;p?MAPK:1.00 ± 0.02;all P<0.05).Conclusion In vitro suppression of glutamate receptors can inhibit the proliferation and migration of WM451LU cells, likely through the mediation of the PKCα?MAPK signaling pathway.