Neural tube defects: role of lithium carbonate exposure in embryonic neural development in a murine model

Background Lithium carbonate (Li2CO3) is widely used in the treatment of clinical-affective psychosis. Exposure to Li2CO3 during pregnancy increases the risk of neural tube defects (NTDs) in offspring, which are severe birth defects of the central nervous system. The mechanism of Li2CO3-induced NTDs remains unclear. Methods C57BL/6 mice were injected with different doses of Li2CO3 intraperitoneally on gestational day 7.5 (GD7.5), and embryos collected at GD11.5 and GD13.5. The mechanisms of Li2CO3 exposure-induced NTDs were determined utilizing immunohistochemistry, western blotting, EdU imaging, enzymatic method, gas chromatography-mass spectrometry (GC-MS), ELISA and HE staining. Results The NTDs incidence was 33.7% following Li2CO3 exposure. Neuroepithelial cell proliferation and phosphohistone H3 level were significantly increased in NTDs embryos, compared with control group (P < 0.01), while the expressing levels of p53 and caspase-3 were significantly decreased. IMPase and GSK-3 beta activity was inhibited in Li2CO3-treated maternal and embryonic neural tissues (P < 0.01 and P < 0.05, respectively), along with decreased levels of inositol and metabolites, compared with control groups (P < 0.01). Conclusions Lithium-induced NTDs model in C57BL/6 mice was established. Enhanced cell proliferation and decreased apoptosis following lithium exposure were closely associated with the impairment of inositol biosynthesis, which may contribute to lithium-induced NTDs. Impact Impairment of inositol biosynthesis has an important role in lithium exposure-induced NTDs in mice model. Lithium-induced NTDs model on C57BL/6 mice was established. Based on this NTDs model, lithium-induced impairment of inositol biosynthesis resulted in the imbalance between cell proliferation and apoptosis, which may contribute to lithium-induced NTDs. Providing evidence to further understand the molecular mechanisms of lithium-induced NTDs and enhancing its primary prevention.