Evidence that elevated glucose causes altered gene expression, apoptosis, and neural tube defects in a mouse model of diabetic pregnancy
Evidence that elevated glucose causes altered gene expression, apoptosis, and neural tube defects in a mouse model of diabetic pregnancy
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DOI：
10.2337/diabetes.48.12.2454
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发表时间：
1999-12-01
期刊：
影响因子：
7.7
通讯作者：
Loeken, MR
中科院分区：
文献类型：
--
作者：
Fine, EL;Horal, M;Loeken, MR
先天性畸形，包括神经管缺陷（NTDs），显着增加的后代的糖尿病母亲。我们以前报道过，在糖尿病妊娠小鼠模型的胚胎中，NTDs与Pax-3基因表达减少有关，Pax-3基因编码一种调节神经管发育的转录因子，Pax-3表达减少导致神经上皮细胞凋亡。在这项研究中，我使用了三种方法来测试葡萄糖是否单独导致糖尿病对胚胎发育的不利影响。首先，与在含有5 mmol/l葡萄糖的培养基中培养相比，在含有15 mmol/l葡萄糖的培养基中的胚胎组织的原代培养抑制Pax-3表达。Pax-3 mRNA定量RT-PCR检测显示，皮下注射葡萄糖诱导妊娠小鼠高血糖可显著抑制Pax-3表达（P < 0.05），并增加神经管凋亡（P < 0.05）。当血糖水平>250 mg/dl时，注射葡萄糖的孕妇NTD显著增加（P < 0.002），但在中度高血糖孕妇（150-250 mg/dl，P = 0.37）中NTD没有增加。第三，根皮苷给药妊娠糖尿病小鼠降低血糖水平和NTDs的发生率。与注射葡萄糖的妊娠一样，根皮苷治疗的糖尿病妊娠NTD发生率与高血糖的严重程度有关，因为NTD在重度高血糖（>250 mg/dl）的糖尿病妊娠中显著增加（P < 0.001），但在中度高血糖妊娠中（150-250 mg/dl，P = 0.35）则无此现象。这两个发现，即葡萄糖升高单独可引起糖尿病妊娠期间观察到的Pax-3表达的变化，以及NTD命运随着血糖水平的显著增加而上升，表明与糖尿病妊娠相关的先天性畸形是由胚胎中调节基因表达的破坏引起的，以响应葡萄糖升高。
Congenital malformations, including neural tube defects (NTDs), are significantly increased in the offspring of diabetic mothers. We previously reported that in the embryos of a mouse model of diabetic pregnancy NTDs are associated with reduced expression of the gene Pax-3, which encodes a transcription factor that regulates neural tube development, and that reduced expression of Pax-3 leads to neuroepithelial apoptosis. In this study, me used three approaches to test whether glucose alone could be responsible for these adverse effects of diabetes on embryonic development. First, primary culture of embryo tissue in medium containing 15 mmol/l glucose inhibited Pax-3 expression compared with culture in medium containing 5 mmol/l glucose. Second, inducing hyperglycemia in pregnant mice by subcutaneous glucose administration significantly inhibited Pax-3 expression (P < 0.05), as demonstrated by quantitative reverse transcription-polymerase chain reaction assay of Pax-3 mRNA, and also increased neural tube apoptosis (P < 0.05). NTDs were significantly increased in glucose-injected pregnancies when blood glucose let els were >250 mg/dl (P < 0.002) but not in moderately hyperglycemic pregnancies (150-250 mg/dl, P = 0.37). Third, phlorizin administration to pregnant diabetic mice reduced blood glucose levels and the rate of NTDs. As seen with glucose-injected pregnancies, the rate of NTDs in phlorizin-treated diabetic pregnancies was related to the severity of hyperglycemia, since NTDs were significantly increased in severely hyperglycemic (>250 mg/dl) diabetic pregnancies (P < 0.001) but not in moderately hyperglycemic pregnancies (150-250 mg/dl, P = 0.35). These two findings, that elevated glucose alone can cause the changes in Pax-3 expression observed during diabetic pregnancy and that the NTD fate rises with significant increases in blood glucose levels, suggest that congenital malformations associated with diabetic pregnancy are caused by disruption of regulatory gene expression in the embryo in response to elevated glucose.