Regulation and roles of the expression of milk fat globule-characteristic gangliosides in murine mammary gland.

小鼠乳腺乳脂肪球特征神经节苷脂表达的调控和作用。

基本信息

批准号：
08680646
负责人：
IWAMORI Masao
金额：
$ 1.6万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

I performed the experiments using primary cultuted cells and SV-40A255-immortalized cells of murine mammary gland to clarify the mechanism and roles of the expression of milk fat globule-characteristic carbohydrate chains during the periods of pregnancy and lactation. The primary cultured cells were maintained in the basal medium containing cortisol and epidermal growth factor, and were found to be initiated the secretion of milk by addition of prolactin in the basal medium. Synthesis of GD1alpha ganglioside was simultaneously obserbed as an event associated with the secretion of milk under stimulation with prolactin, and was found to be trigered by activations of GM1balpha2-6 sialyltransferase and ceramide lactoside beta1-4N-acetylgalactosaminyltransferase. Also, cholesterol sulfotransferase was highly activated in the cells with secretion of milk, but it was found to be induced by stimulation with epidermal growth factor alone, indicating that the induction of cholesterol sulfotransf … More erase is associated with the growth of mammary epithelial cells. In the case of immortalized cells, the induction of cholesterol sulfotrasferase was observed under stimulation of epidermal growth factor, but production of milk fat grobule, as well as synthesis of GD1alpha, was not observed under the same condition as that for primary cultured cells. The enzuymes thus regulated during the process of milk secretion were found to be controled at the translational level. Then, I invertigated the possible roles of cholesterol sulfate and GD1alpha ganglioside. From the observation that cholesterol sulfate was distributed in the epithelial cells of gastrointestinal tract under the duodenum, where was exposed to the pancreatic digestive enzymes, it was expected to protect the cells from the action of digestive enzymes. As was expected, cholesterol sulfate was found to possess the inhibitory activity toward several proteases, DNase and glycosidases, and one of the major function of cholesterol sulfate in the epithelial cells of mammary gland was found to protect the cells from tissue injury with several enzymes screted during the production of milk. On the other hand, GD1alpha gangloside as the major negatively charged lipids in the fat globule membrane was clarified to be the receptor molecules for toxins from Cl.botulinum type A and type E,and Cl.tetani, indicating that it fuction to protect neonates from the bacterial infections. Less

我使用原代培养的细胞和鼠乳腺的SV-40A255剥离细胞进行了实验，以阐明在妊娠和哺乳期间，牛奶脂肪脂肪球 - 特征碳水化合物链的表达的机制和作用。原代培养细胞保持在含有皮质醇和表皮生长因子的碱性培养基中，并发现通过在碱性培养基中添加催乳素来开始分泌牛奶。仅将GD1Alpha神经节苷脂的合成视为与催乳素刺激下的牛奶分泌有关的事件，并被发现是由GM1BALPHA2-6 2-6硫化酶的激活触发的，而神经酰胺乳糖酸酯β1-4N-NN-NN-NN-乙酰乙酰乳糖乳酰胺乳酸乳酰胺氨基氨基氨基氨基氨基氨基氨基氨基氨基糖基酶。同样，胆固醇亚硫代转移酶在分泌牛奶的细胞中被高度激活，但发现仅通过表皮生长因子刺激诱导它，表明胆固醇磺胺硫素的诱导……更多的擦除与乳腺上皮细胞的生长有关。在永生细胞的情况下，在表皮生长因子刺激下观察到胆固醇磺胺倍倍酶的诱导，但是在与原代培养细胞的情况下，在相同的条件下观察到牛奶脂肪grobule以及GD1Alpha的合成的产生并未观察到GD1Alpha的合成。因此，发现在牛奶分泌过程中受调节的烯酶在翻译水平上受到控制。然后，我倒置硫酸胆固醇和GD1Alpha神经节的可能作用。从观察到硫酸胆固醇分布在十二指肠下胃肠道的上皮细胞中，该细胞暴露于胰腺消化酶，预计将保护细胞免受消化酶的作用。正如预期的那样，发现硫酸胆固醇具有对几种蛋白酶，DNase和糖苷酶的抑制活性，并且发现在乳腺的上皮细胞中，硫酸胆固醇的主要功能之一可保护细胞在牛奶生产过程中用几种酶染色的细胞免受组织损伤的保护。另一方面，GD1Alpha神经苷作为脂肪球膜中的主要带负电荷的脂质被阐明为A型A型和E型cl.botulinum type a和cl.tetani的受体分子，表明IT曲目可保护新生素免受细菌感染的侵害。较少的