The suppressed autophagy induced by carbon disulfide could be rescued by N-carbamoyl glutamate during the window of embryo implantation in mice.

OBJECTIVES

To explore the effects of carbon disulfide (CS) and N-carbamoyl glutamate (NCG) on autophagy during the window of embryo implantation in mice and whether dietary NCG supplementation can promote embryo implantation in case of CS exposure.

METHODS

Pregnant mice that received single intraperitoneal injection of CS on Gestational day (GD)4 were fed basal diet with or without NCG supplementation from GD1 to endpoints. The control mice were injected solvents. There were four endpoints (GD5, GD6, GD7 and GD9 endpoints) in each group. The uterus was collected on endpoints to detect autophagy-related markers by using the methods of transmission electron microscopy (TEM), immunohistochemistry (IHC), quantitative real-time polymerase chain reaction (qRT-PCR) and ELISA.

RESULTS

The P62 brown punctate staining increased in CS exposure group and reduced after dietary NCG supplementation, which was opposite with LC3B, Beclin1 and ATG5 on GD5 endpoint. Simultaneously, P62 protein expression raised 43.33% on GD5 endpoint (p < 0.01) when exposed to CS and descended to the control level after NCG supplementation. The rate of decline of LC3B and Beclin1 proteins were 27.04% (p < 0.01) and 23.27% (p < 0.05) on GD5 endpoint, 20.20% (p < 0.05) and 11.30% on GD7 endpoint in CS exposure group, respectively, then NCG supplementation caused the LC3B and Beclin1 protein expression to rise in different degrees. Comparatively, the mRNA expression of all autophagy-related gene changed more apparently on three endpoints than the protein expression. The images of TEM showed that nearly no autophagosome could be seen in CS exposure group, while dietary NCG supplementation increased the number of autophagosome obviously on GD5 endpoint. The number of implanted embryos which declined due to CS exposure returned to normal in NCG supplementation group.

CONCLUSIONS

Dietary NCG supplementation could rescue the suppressed autophagy induced by CS in the window of implantation and increase the number of implanted embryos.