Department of Cell Biology and Physiology, Brigham Young University, Provo, UT, USA.
Department of Nutrition, Dietetics and Food Science, College of Life Sciences, Brigham Young University, Provo, UT, USA.
Free Radic Res. 2021 Dec;55(11-12):1130-1144. doi: 10.1080/10715762.2021.2017913. Epub 2022 Jan 19.
Valproic acid (VPA) is an antiepileptic, bipolar, and migraine medication, which is associated with embryonic dysmorphology, more specifically neural tube defects (NTDs), if taken while pregnant. One mechanism by which VPA may cause NTDs is through oxidative stress that cause disruption of cell signaling. However, mechanisms of VPA-induced oxidative stress are not fully understood. Since VPA is a deacetylase inhibitor, we propose that VPA promotes mitochondrial superoxide dismutase-2 (SOD2) acetylation, decreasing SOD2 activity and increasing oxidant levels. Using the pluripotent embryonal carcinoma cell line, P19, VPA effects were evaluated in undifferentiated and neurodifferentiated cells. VPA treatments increased oxidant levels, oxidized the glutathione (GSH)/glutathione disulfide (GSSG) redox couple, and decreased total SOD and SOD2 activity in undifferentiated P19 cells but not in differentiated P19 cells. VPA caused a specific increase in mitochondrial oxidants in undifferentiated P19 cells, VPA did not alter respirometry measurements. Immunoblot analyses demonstrated that VPA increased acetylation of SOD2 at lysine (AcK68 SOD2) in undifferentiated P19 cells but not in differentiated P19 cells. Pretreatments with the Nrf2 inducer, dithiol-3-thione (D3T), in undifferentiated P19 cells prevented increased oxidant levels, GSH/GSSG redox oxidation and restored total SOD and SOD2 activity, correlating with a decrease in AcK68 SOD2 levels. In embryos, VPA decreased total SOD and SOD2 activity and increased levels of AcK68 SOD2, and D3T pretreatments prevented VPA effects, increasing total SOD and SOD2 activity and lowering levels of AcK68 SOD2. These data demonstrate a potential, contributing oxidizing mechanism by which VPA incites teratogenesis in developing systems. Moreover, these data also suggest that Nrf2 interventions may serve as a means to protect developmental signaling and inhibit VPA-induced malformations.
丙戊酸（VPA）是一种抗癫痫药、双相药和偏头痛药，如果在怀孕期间服用，它与胚胎畸形有关，特别是神经管缺陷（NTD）。VPA 引起 NTD 的一种机制是通过氧化应激破坏细胞信号。然而，VPA 诱导氧化应激的机制尚不完全清楚。由于 VPA 是一种去乙酰化酶抑制剂，我们提出 VPA 促进线粒体超氧化物歧化酶-2（SOD2）乙酰化，降低 SOD2 活性并增加氧化剂水平。使用多能胚胎癌细胞系 P19，评估了 VPA 在未分化和神经分化细胞中的作用。VPA 处理增加了氧化应激水平，氧化了谷胱甘肽（GSH）/谷胱甘肽二硫化物（GSSG）氧化还原对，并降低了未分化 P19 细胞中的总 SOD 和 SOD2 活性，但未降低分化 P19 细胞中的总 SOD 和 SOD2 活性。VPA 导致未分化的 P19 细胞中线粒体氧化剂的特异性增加，但未改变呼吸测定测量值。免疫印迹分析表明，VPA 增加了未分化的 P19 细胞中 SOD2 赖氨酸（AcK68 SOD2）的乙酰化，但未增加分化的 P19 细胞中的乙酰化。在未分化的 P19 细胞中用 Nrf2 诱导剂二硫醇-3-硫酮（D3T）预处理可防止氧化应激水平升高、GSH/GSSG 氧化还原和恢复总 SOD 和 SOD2 活性，与 AcK68 SOD2 水平降低相关。在胚胎中，VPA 降低了总 SOD 和 SOD2 活性并增加了 AcK68 SOD2 的水平，而 D3T 预处理可防止 VPA 的作用，增加了总 SOD 和 SOD2 活性并降低了 AcK68 SOD2 的水平。这些数据表明 VPA 引发发育系统中畸形的潜在促氧化机制。此外，这些数据还表明 Nrf2 干预可能是保护发育信号和抑制 VPA 诱导的畸形的一种手段。
