Studies on physiological functions of ovalbumin and occurrence of neural tube defects due to deprivation of ovalbumin in chick embryo.

鸡胚卵清蛋白生理功能及卵清蛋白缺失导致神经管缺陷发生的研究

• 批准号: 19580343
• 负责人: SUGIMOTO Yasushi
• 金额: $ 3.08万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2007
• 资助国家: 日本
• 起止时间: 2007 至 2009
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-19580343/
• 关键词: オボアルブミン; セルピン; 形態形成因子; 神経管閉鎖障害; 遺伝子発現; 神経管閉鎖阻害; NTD胚; 発生異常; 神経管欠損; 熱安定型オボアルブミン; 形態形成; 生理機能; オボアルブミン; セルピン; 形態形成因子; 神経管閉鎖障害; 遺伝子発現; 神経管閉鎖阻害; NTD胚; 発生異常; 神経管欠損; 熱安定型オボアルブミン; 形態形成; 生理機能

Ovalbumin has been classified as a homolog of serine protease inhibitor (serpin), although little is known of its function except that it may be a nutrient source. We have shown that, during embryonic development, native molecules of ovalbumin (N-ovalbumin) are incorporated into tissues without degradation while undergoing configurational changes into a heat-stable form called 'HS-ovalbumin.' Here, to investigate the indispensability of HS-ovalbumin, we utilized an in vitro culture method by which chick embryos isolated from eggs at Stage 7 (before the neural tube begins to close) could develop normally for up to 24h. When endogenous, remnant ovalbumin was blocked by adding anti-ovalbumin polyclonal IgG to the medium, the isolated embryos became irregular particularly in brain tissue, resulting in the so-called neural tube deficiency (NTD). The embryos with NTD showed reduced signals for apoptosis and cell proliferation. Moreover, IgG-treated embryos were rescued by adding a sufficient … More amount of HS-ovalbumin to the medium, attaining normal morphologies without NTD. HS-ovalbumin exhibited a higher rescue rate than N-ovalbumin and S-ovalbumin, the latter being another heat-stable counterpart that occurs artificially by heating N-ovalbumin in vitro. These results indicate that ovalbumin (particularly in the HS-form) is essential in embryonic organogenesis, including neural tube formation. present results show also that the ovalbumin-deprived embryos gave decreased in situ signals for TUNEL reagents and for PCNA/c-Myc proteins, which mirror changes in apoptosis and cell proliferation, respectively. Also the ovalbumin deprival affect the embryos on many gene expressions including differentiation-inducing factors related to morphogenesis. Expressions of FGF8 and slug have decreased markedly, whereas those of BMP4 and Pax3 have increased over 3-fold. However, whether each of these alterations is a cause or a result of morphogenetic aberrancy is unclear. Since ovalbumin belongs to the serpin superfamily, there is a possibility that it shows direct interactions with some crucial differentiation-inducing factors. Less

椭圆蛋白已被归类为丝氨酸蛋白抑制剂（SERPIN）的同源物，尽管对其功能知之甚少，除了它可能是营养源。我们已经表明，在胚胎发育过程中，将卵巢蛋白的天然分子（N-卵蛋白）纳入组织而不会降解的过程中，同时将构型变化纳入称为“ HS-overbumin”的热稳定形式。在这里，为了研究HS-OverBumin的不可或缺的性能，我们利用了一种体外培养方法，该方法通过该方法在第7阶段（神经管开始关闭之前）从卵中分离出来的雏鸡胚胎可以正常发育长达24小时。当内源性，残留的椭圆蛋白通过在培养基中添加抗卵蛋白多克隆IgG来阻断，隔离的胚胎变得不规则，特别是在脑组织中，导致所谓的神经管缺乏症（NTD）。带有NTD的胚胎显示凋亡和细胞增殖的信号降低。此外，通过在培养基中添加了足够量的HS-overbumin，对IgG处理的胚胎进行了反应，从而获得了没有NTD的正常形态。 HS-OverBumin的救援率比N-卵蛋白和S-卵蛋白表现出更高的救援率，后者是另一种热稳定的对应物，它通过体外加热N-卵蛋白通过人为而发生。这些结果表明，椭圆蛋白（部分在HS形式中）对于胚胎器官发生至关重要，包括中性管的形成。目前的结果还表明，卵蛋白剥夺的胚胎的原位信号下降了TUNEL试剂和PCNA/C-MYC蛋白，这些胚胎分别反映了细胞凋亡和细胞增殖的变化。同样，卵蛋白剥夺会影响许多基因表达的胚胎，包括与形态发生有关的分化诱导因子。 FGF8和SLUG的表达明显降低，而BMP4和PAX3的表达却增加了3倍以上。但是，这些改变中的每一个都是原因还是形态发生异常的结果尚不清楚。由于椭圆蛋白属于Serpin超家族，因此有可能与某些关键分化诱导因子显示直接相互作用。较少的