Department of Hepatobiliary and Pancreatic Surgery and Liver Transplant Center, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China; Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi, China; Institute of Liver Diseases and Organ Transplantation, Shanxi Medical University, Taiyuan, Shanxi, China; Department of Neurosurgery, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China.
Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi, China.
Neurochem Int. 2024 Nov;180:105861. doi: 10.1016/j.neuint.2024.105861. Epub 2024 Sep 20.
S-adenosylmethionine (SAM) plays a critical role in the development of neural tube defects (NTDs). Studies have shown that the paired box 3 (Pax3) gene is involved in neural tube closure. However, the exact mechanism between Pax3 and NTDs induced by SAM deficiency remains unclear. Here, The NTD mouse model was induced using cycloleucine (CL), an inhibitor of SAM biosynthesis, to determine the effect of Pax3 on NTDs. The effect of CL on NTD occurrence was assessed by 5-ethynyl-2'-deoxyuridine (EdU) staining, immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), and Western blot in NTD embryonic brain tissues and immortalized hippocampal neuron cells (HT-22). A high incidence of NTDs was observed when CL was administered at a dose of 200 mg/kg body weight. The levels of SAM and Pax3 were significantly reduced in NTD embryonic brain tissues and HT-22 cells after CL exposure. Decreased proliferation and excessive apoptosis were observed in neuroepithelial cells of NTD embryos and HT-22 cells under SAM deficiency, but these effects were reversed by overexpression of Pax3. These results suggest that decreased expression of Pax3 impairs the dynamic balance between cellular proliferation and apoptosis, contributing to NTDs induced by SAM deficiency, which would provide new insights for clarifying the underlying mechanism of NTDs.
S-腺苷甲硫氨酸（SAM）在神经管缺陷（NTDs）的发展中起着关键作用。研究表明，配对盒基因 3（Pax3）参与神经管闭合。然而，SAM 缺乏引起的 Pax3 与 NTDs 之间的确切机制尚不清楚。在这里，使用 SAM 生物合成抑制剂环亮氨酸（CL）诱导 NTD 小鼠模型，以确定 Pax3 对 NTDs 的影响。通过 5-乙炔基-2'-脱氧尿苷（EdU）染色、免疫组织化学、末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）、实时定量逆转录聚合酶链反应（qRT-PCR）和 Western blot 评估 CL 对 NTD 发生的影响在 NTD 胚胎脑组织和永生化海马神经元细胞（HT-22）中。当 CL 以 200mg/kg 体重的剂量给药时，观察到 NTD 的发生率很高。CL 暴露后，NTD 胚胎脑组织和 HT-22 细胞中的 SAM 和 Pax3 水平明显降低。在 SAM 缺乏的神经上皮细胞中观察到 NTD 胚胎和 HT-22 细胞的增殖减少和过度凋亡，但过表达 Pax3 可逆转这些影响。这些结果表明，Pax3 的表达减少破坏了细胞增殖和凋亡之间的动态平衡，导致 SAM 缺乏引起的 NTDs，这将为阐明 NTDs 的潜在机制提供新的见解。
