Inositol Deficiency Increases Neural Tube Defect Susceptibility by PI3K/AKT Signaling Pathway (P11-009-19)

Abstract

ObjectivesTo explore the possible mechanisms of inositol deficiency in neural tube defects (NTDs). MethodsThe gas chromatography–mass spectrometry (GC-MS) analysis was used to detect the plasma inositol levels of NTD pregnancies and non-NTD controls from a high-prevalence area of Shanxi Province in northern China. A maternal MI deficient mouse model was established by using intraperitoneal injection of Li2CO3, which act as an inhibitor of inositol 1-phosphatase (IMPase) and a key enzyme for the synthesis and recycling of inositol in vivo. Using the phospho-protein array to find the possible differential phosphorylated proteins between the NTD and control group in MI deficiency human and mouse respectively. We performed pathway analysis on the differential phosphorylated proteins using KEGG databases of human NTDs with MI deficiency. ResultsWe found that maternal MI deficiency was associated with an increased risk of NTDs (Pearson correlation coefficient r = –0.19, P < 0.05). The MI levels of the pregnant mouse decreased significantly after Li2CO3 injection and reach to the lowest level at 8h after the injection (23.72mg/L vs 44.15 mg/L P < 0.05). Repeat trials showed that the average incidence of NTDs was 26.7%. The NTD phenotypes included encephalocele (85.8%), anencephaly (5.7%) and spina bifida (8.5%). The result of phospho-protein array displayed that PI3K-Akt signaling pathway (hsa04151) was the most enriching pathway. We then validated the proteins involved in the PI3K-Akt signaling pathway using a mouse phospho-protein array. A total of 21 proteins were found to be differentially phosphorylated (Fold change > 1.5), and 14 of them were differentially phosphorylated in both the human and mouse, including YWHAZ, AKT1, AKT2, BCL2, CCND1, NOS3, PTK2, IRS1, MTOR (mTOR), TP53, RPS6KB1 (p70S6K), PDPK1, PPP2CA and PTEN. Further pathway analysis on the 14 common differentially phosphorylated protein found that PI3K/Akt/mTOR/p70S6K pathway was the most disturbed signaling pathway induced by MI deficiency. ConclusionsOur study indicated that PI3K-Akt signaling pathway might be one of the important regulatory mechanisms of inositol deficiency-induced NTDs. Funding SourcesThis study was supported by The National Key Basic Research Program (2018YFC1002500), National Nature Science Foundation of China (81571443 to JW, 81801451 to JG).