ESSENTIALITY OF INSULIN FOR THE ACCUMULATION OF RAT MILK PROTEIN MRNA'S

胰岛素对于大鼠乳蛋白 mRNA 积累的重要性

• 批准号: 4691827
• 负责人: P K QASBA
• 金额: --
• 依托单位: DIVISION OF CANCER BIOLOGY AND DIAGNOSIS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/4691827
• 关键词: cell differentiation; cortisol; gene expression; growth factor; hormone regulation /control mechanism; insulin; messenger RNA; milk; tissue /cell culture

The control of overt differentiation of mammary gland in vitro involves an interplay between polypeptide and steroid hormones. Insulin, hydrocortisone and prolactin are absolutely required for the expression of milk protein genes. Role of individual hormones is being studied. These studies have shown: 1) In the presence of glucocorticoid and prolactin insulin is absolutely required for the expression of milk protein genes. In the present study it was shown that the accumulation effect on the 25K rat casein mRNA does not reflect stabilization of the transcript by insulin. Rather, insulin is essential for its synthesis in the presence of glucocorticoid and prolactin. Thus, insulin can be considered as a developmental hormone in the mammary system. Neither fetal calf serum nor Multiplication stimulating activity (MSA) or epidermal growth factor (EGF) can substitute insulin effect on differentation, though these hormones can sustain mammary cell vability in culture. 2) There is absolute requirement of hydrocortisone for accumulation of these messages, specifically the accumulation of 42K casein mRNA in mammary tissue from adrenalectomized, virgin rat is almost 20x higher in the presence of exogenous hydrocortisone than in its absence. Accumulation of 25K casein mRNA is also totally dependent on the steroid.

体外乳腺明显分化的控制涉及 多肽和类固醇激素之间的相互作用。 胰岛素， 氢化可的松和催乳素是绝对需要的 牛奶蛋白基因。 正在研究各个激素的作用。 这些 研究表明：1）在存在糖皮质激素和催乳素的情况下 胰岛素是牛奶蛋白基因表达绝对必需的。 在本研究中，结果表明积累对25K 大鼠酪蛋白mRNA不能反映转录本的稳定 胰岛素。 相反，胰岛素对于它在存在的情况下是必不可少的 糖皮质激素和催乳素。 因此，胰岛素可以被视为 乳腺系统中的发育激素。 胎牛血清既不 繁殖刺激活性（MSA）或表皮生长因子（EGF） 尽管这些激素可以 在培养中维持乳腺细胞的可及性。 2）绝对有 需要氢化可的松积累这些消息， 特别是从乳腺组织中积累了42k酪蛋白mRNA从 在存在的情况下 外源氢化可的松比在其不存在的情况下。 25K酪蛋白的积累 mRNA也完全取决于类固醇。