GENETIC REGULATION OF THE HEPATIC ACUTE PHASE RESPONSE

哺乳动物的动态平衡强烈依赖于正确的 发育阶段、组织和激素特异性表达 血浆蛋白。受控制的血浆蛋白生产是 尤其是在全身损伤期间，当身体 对基本血浆蛋白的需求必须由一个 肝脏合成即刻增加。这个项目的总体目标是 该项目是对大部分未知的遗传元素进行表征 控制血浆蛋白基因的活性，特别是那些 由全身损伤引起的。为了识别这些元素， 对近交系和野生系小鼠进行了调查 寻找血浆蛋白基因表达的遗传变异。M.Caroli 揭示了两个特殊的特征：1)结构基因 α1-酸性糖蛋白(AGP)已扩增到4-6个拷贝， 每个编码具有不同程度的诱导性的不同形式 通过炎症，以及2)单一的，肝脏特异性的调节 α1-抗胰蛋白酶(AT)的基因已经改变，以至于 该基因在肝脏和肾脏中的表达水平相同。这些独特的 在卡罗利分枝杆菌中进化的遗传特性将被用来评估 决定a)急性时相诱导的那些基因元件 AGP基因和b)AT基因表达的组织特异性。 实验方法如下：1)结构 高、低可诱导的AGP和AT的基因将被分离。 2)转录活性和调控反应 不同的AGP基因将通过将基因导入到 人和大鼠肝癌细胞对这两种药物的反应 肝脏急性期反应的最有效的介体， 肝细胞刺激因子和糖皮质激素。要确定 AT基因表达的肝肾特异性， 卡罗利分枝杆菌AT基因的活性将被测量和比较 将家蝇AT基因转入肝脏和 肾组织培养细胞。在证明了正确的监管之后 在AGP和AT基因中，顺式调节元件将 相对于结构基因定位。3)范围 哪些功能AGP和AT基因序列支持正确 组织、激素和发育调节将在 转基因小鼠。4)最后，细胞因素相互作用 具体地说，具有顺应性的监管要素将是 已确认身份。这些对卡罗利分枝杆菌基因的研究结果将 为控制组织特异性的信号提供新的见解 以及血浆蛋白基因的炎症诱导性。

Homeostasis of mammals is strongly dependent on correct developmental stage-, tissue- and hormone-specific expression of plasma proteins. Regulated plasma protein production is especially important during systemic injury when the body's demand for essential plasma proteins must be met by an immediate increase in hepatic synthesis. The overall goal of this project is to characterize the largely unknown genetic elements governing the activity of plasma protein genes, in particular those induced by systemic injury. In order to identify such elements, inbred strains and wild derived species of mice had been surveyed for genetic variants in plasma protein gene expression. M. caroli revealed two exceptional features: 1) the structural gene for alpha 1-acid glycoprotein (AGP) has been amplifed to 4-6 copies, each encoding distinct forms with different degrees of inducibility by inflammation, and 2) the regulation of the single, liver specific gene for alpha1-antitrypsin (AT) has been altered such that the gene is equally expressed in liver and in kidney. These unique genetic properties, evolved in M. caroli, will be used to assess those gene elements determining a) the acute phase induction of AGP gene and b) the tissue-specificity of the AT gene expression. The experimental approaches will be as follows: 1) The structural genes for high and low inducible AGPs and for AT will be isolated. 2) The transcriptional activity and regulatory response of the different AGP genes will be tested by introducing the genes into human and rat hepatoma cells which are responsive to the two most potent mediators of hepatic acute phase response, the hepatocyte stimulating factor and glucocorticoids. To identify the liver and kidney specificity of AT gene expression, the activity of the M. caroli AT gene will be measured and compared to the M. domesticus AT gene by transfection into hepatic and renal tissue culture cells. After demonstrating correct regulation of the AGP and AT genes, the cis-acting regulatory elements will be localized relative to the structural genes. 3) The extent to which functional AGP and AT gene sequences support correct tissue, hormone and developmental regulation will be assessed in transgenic mice. 4) Lastly, the cellular factors interacting specifically with the cis-acting regulatory elements will be identified. The results from these studies on M. caroli genes will provide new insights into the signals controlling tissue specific and inflammation-inducibility of plasma protein genes.