ETHANOL MEDIATED OSTEOPOROSIS AND INTERLEUKIN 6

描述(改编自《调查者摘要》)：很好 证实长期接触酒精会导致骨质疏松症， 使人虚弱且代价高昂的疾病。然而，分子机制通过 目前尚不清楚乙醇对骨骼的影响是什么。有证据表明 乙醇既可能增加骨吸收，又可能抑制骨生成， 导致骨量减少。促炎症细胞因子白介素6 白介素6(IL-6)是破骨细胞在骨组织中活性的重要介质。 此外，研究人员还提供了乙醇诱导IL-6的证据 人骨髓基质细胞的表达及其IL-6启动子活性 并提高小鼠血清IL-6水平。因此，他们假设 乙醇诱导骨和骨组织中IL-6基因转录 破骨细胞介导骨吸收的微环境。 为了探索这一假设，调查人员将执行以下操作 具体目的：1.阐明乙醇对S的影响机制 人骨髓基质中IL-6启动子转录活性的研究 S乙醇对IL-6影响的程度和方法的测定 人骨髓基质细胞中mRNA的稳定性；3.证实IL-6 对乙醇所致小鼠体内骨丢失的机制有一定的贡献。 目标1将通过a)评估乙醇S对核的影响来实现 转录产物的产生，b)IL-6启动子的突变分析 乙醇反应顺式作用元件，以及c)测量 乙醇对人骨髓中转录因子活性的影响 基质细胞系和原代人基质细胞。目标2将是 通过评估a)乙醇诱导的调制mRNA半衰期， B)IL-6信使核糖核酸3-非翻译区的突变分析 以识别受乙醇影响的区域，以及c)识别 乙醇诱导的人3-UTR反式作用因子的变化 骨髓基质细胞系和原代人基质细胞。目标3将是 通过评估小鼠骨骼代谢的差异来完成 不表达IL-6(IL-6基因敲除)和对照小鼠(可以表达 IL-6)饲喂液体乙醇饲料3周或24周。骨骼新陈代谢将 通过包括骨矿物质变化在内的各种测量进行评估 通过总骨灰、骨髓破骨细胞产量来评估含量 通过骨髓培养、破骨细胞活性测定、凹陷吸收试验、活体骨 尿吡啶交联物的吸收和破骨细胞的活性 骨组织形态计量学。

DESCRIPTION (Adapted from the Investigator's Abstract): It is well established that chronic ethanol exposure can induce osteoporosis, a debilitating and costly disease. However, the molecular mechanisms through which ethanol achieves its influence on bone is unknown. There is evidence that ethanol may both increase bone resorption and inhibit bone production, resulting in osteopenia. The proinflammatory cytokine, interleukin-6 (IL-6), is an important mediator of osteoclast activity on bone. Furthermore, the investigators provide evidence that ethanol induces IL-6 expression and IL-6 promoter activity in a human bone marrow stromal cell line and increases serum IL-6 levels in mice. Accordingly, they hypothesize that ethanol induces IL-6 gene transcription in bone and the bone microenvironment culminating in osteoclast-mediated bone resorption. To explore this hypothesis, the investigators will perform the following specific aims: 1. Elucidate the mechanism of ethanol s influence on transcriptional activity of the IL-6 promoter in human bone marrow stromal cells; 2. Determine the degree and method of ethanol s influence on IL-6 mRNA stability in human bone marrow stromal cells; 3. Demonstrate that IL-6 contributes to the mechanism of ethanol-induced bone loss in vivo in mice. Aim 1 will be accomplished by a) evaluation of ethanol s effect on nuclear transcript production, b) mutational analysis of the IL-6 promoter for ethanol-responsive cis-acting elements, and c) measurement of ethanol-mediated changes in transcription factor activity in a human marrow stromal cell line and primary human stromal cells. Aim 2 will be accomplished by evaluation of a) ethanol induced modulation mRNA half-life, b) mutational analysis of the 3-untranslated region (UTR) of the IL-6 mRNA to identify regions effected by ethanol, and c) identification of ethanol-induced changes in trans-acting factors on the 3 -UTR in human marrow stromal cell line and primary human stromal cells. Aim 3 will be accomplished by evaluating for differences in bone metabolism in mice which cannot express IL-6 (IL-6 gene knockout) and control mice (which can express IL-6) fed a liquid ethanol diet for 3 or 24 weeks. Bone metabolism will be evaluated by a variety of measurements including alterations in bone mineral content as assessed by total skeletal ash, bone marrow osteoclast production by marrow culture, osteoclast activity by pit resorption assay, in vivo bone resorption by urinary pyridinoline crosslinks, and osteoclast activity by bone histomorphometry.