Guo Jin, Chen Zhongzhong, Yue Huixuan, Li Shen, Sun Guohui, Zhang Feng, Zhong Rugang, Lyu Jianjun, Yang Yanwei, Wang Xiuwei, Bao Yihua, Zou Jizhen, Guan Zhen, Zhang Ting, Wang Jianhua
Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China.
Mol Neurobiol. 2025 Apr 28. doi: 10.1007/s12035-025-04972-9.
Previous studies have demonstrated that peri-conceptional inositol supplementation could effectively ameliorate the recurrence of neural tube defects (NTDs); though, the mechanism remains unclear. In the current investigation, we detected the myo-inositol (MI) levels in maternal plasma and embryonic tissues in a Chinese population with high prevalence of NTDs and found maternal MI deficiency increased NTD susceptibility in this area. Pregnant mice were randomly divided into 2 groups. The control group was treated with 0.9% saline, while the experimental group was treated with IMPase inhibitor by intraperitoneal injection on E7.5 to generate the maternal MI-deficient mouse model, followed by comprehensive phenotypic and molecular analysis at E13.5. Corresponding in vitro experiments treated neural stem cells (NSCs) for 16 h with IMPase inhibitor, MI supplementation, or specific PI3K and mTOR inhibitors to systematically investigate the downstream signaling pathways. We observed aberrant activation PI3K/Akt/mTOR signaling and reduced autophagy in a maternal MI deficiency mouse model after ruling out the genetic perturbations. Further in vitro kinase assay showed that MI negatively regulated PI3K activity, in a dose-dependent manner, which possibly due to the hydrogen bond interactions between amino acid residues in the ATP-binding site of PI3K and inositol. MI deficiency NSCs also presented PI3K/AKT/mTOR pathway activation concurrent with reduced autophagy level; MI supplementation or inhibition of the PI3K/Akt/mTOR pathway could rescue MI deficiency-induced autophagy impairment. Finally, we validated decreased autophagy levels as well as hyperactivation of the PI3K/Akt/mTOR pathway by MI deficient human NTD embryonic neural tissues. Our results suggested that maternal MI deficiency might increase susceptibility to NTDs. Low levels of MI might impair autophagy in the developing neural tube involving upregulation of PI3K/Akt/mTOR pathway.
先前的研究表明，受孕前补充肌醇可有效改善神经管缺陷（NTDs）的复发；然而，其机制仍不清楚。在当前的研究中，我们检测了中国NTDs高发人群母体血浆和胚胎组织中的肌醇（MI）水平，发现母体MI缺乏增加了该地区NTDs的易感性。将怀孕小鼠随机分为2组。对照组用0.9%生理盐水处理，而实验组在E7.5通过腹腔注射IMPase抑制剂处理以建立母体MI缺乏小鼠模型，随后在E13.5进行全面的表型和分子分析。相应的体外实验用IMPase抑制剂、补充MI或特异性PI3K和mTOR抑制剂处理神经干细胞（NSCs）16小时，以系统研究下游信号通路。在排除遗传干扰后，我们在母体MI缺乏小鼠模型中观察到PI3K/Akt/mTOR信号异常激活和自噬减少。进一步的体外激酶分析表明，MI以剂量依赖性方式负调节PI3K活性，这可能是由于PI3K的ATP结合位点中的氨基酸残基与肌醇之间的氢键相互作用。MI缺乏的NSCs也表现出PI3K/AKT/mTOR途径激活，同时自噬水平降低；补充MI或抑制PI3K/Akt/mTOR途径可挽救MI缺乏诱导的自噬损伤。最后，我们通过MI缺乏的人类NTD胚胎神经组织验证了自噬水平降低以及PI3K/Akt/mTOR途径的过度激活。我们的结果表明，母体MI缺乏可能会增加NTDs的易感性。低水平的MI可能会损害发育中的神经管中的自噬，包括PI3K/Akt/mTOR途径的上调。
