CYTOKINES AND STEROID ENZYME EXPRESSION IN BRAIN

细胞因子可以解释许多临床和组织病理学 在艾滋病患者大脑中的发现。 我们的长远目标是 阐明细胞因子作用的细胞和分子机制 在大脑里。 间接证据表明，一些尼古丁诱导的 神经系统症状可能是γ- 氨基丁酸（GABA）受体复合物。 激活GABAA 受体导致神经症状，类似于其中一些 艾滋病患者表现出的症状，例如，焦虑、嗜睡和运动 功能障碍 此外，细胞因子可以像GABA激动剂一样起作用，因为它们 诱导镇痛。 因为GABA是主要的抑制性神经递质， 因为GABA受体普遍分布在大脑中， 在大脑中，细胞因子对受体的异常激活可能会影响广泛的 一系列的大脑功能。 我们的工作假设是， 神经系统症状部分是由于GABA受体的激活 复杂，激活是通过增加 GABA受体配体3 α-羟基- 5 α-二氢孕酮（3 α DHP）。 我们的研究集中在3alphaDHP上， 因为它是GABAA受体的极其有效的配体和激活剂 因为它是在大脑中产生的。 我们最近实施了一项 分离的胎脑细胞表达的优良培养体系 包括3 α-羟基类固醇在内的几种类固醇代谢酶 氧化还原酶（3alpha-HSOR），催化 3 α-DHP。 S.A. 1：验证聚集体培养系统可以 作为研究3 α-HSOR表达调控的模型。 我们将确定在完整脑中表达的3alpha-HSOR是 在我们的培养物中表达的酶;使用分子生物学方法。 S.A. 2：检验白细胞介素（IL）-1诱导3 α DHP的假设 生产的聚集体。 我们将研究IL-1对 3 α-HSOR mRNA和蛋白质的稳态水平，以及酶 活动 我们将定义IL-1的时程和剂量依赖性， 作用和是否有一个关键的时间在培养过程中，IL-1 发挥其作用。 这些结果将作为基础， 广泛的，全面的建议，以阐明分子机制 脑中3 α-HSOR表达的潜在细胞因子调节。 因此，这些研究的结果将提供新的见解， 细胞因子作用的细胞和分子机制及其 在HIV感染者神经系统症状的产生中的作用。

Cytokines could account for many of the clinical and histopathological findings in the brains of AIDS patients. Our long-term objectives are to elucidate the cellular and molecular mechanisms underlying cytokine actions in the brain. Indirect evidence suggests that some of the cytokine-induced neurological symptoms may be the consequence of activation of the gamma- aminobutyric acid (GABA) receptor complex. Activation of the GABAA receptor results in neurological symptoms that are similar to some of these exhibited by AIDS patients, e.g., anxiety, drowsiness, and motor dysfunction. Moreover, cytokines can act like GABA agonists in that they induce analgesia. Because GABA is the major inhibitory neurotransmitter in the brain and because the GABA receptor is ubiquitously distributed in the brain, abnormal activation of the receptor by cytokines may affect a wide range of brain functions. Our working hypothesis is that cytokine-induced neurological symptoms are due, in part, to activation of the GABA receptor complex and that activation is brought about by increasing the extracellular concentrations of the GABA-receptor ligand 3alpha-hydroxy- 5alpha-dihydroprogesterone (3alphaDHP). We focus our studies on 3alphaDHP, since it is an extremely potent ligand and activator of the GABAA receptor and since it is produced within the brain. We have recently implemented an excellent culture system of dissociated fetal brain cells expressing several steroid metabolizing enzymes including 3alpha-hydroxysteroid oxidoreductase (3alpha-HSOR), the enzyme catalyzing the formation of 3alphaDHP. S.A. 1: to validate that the aggregate culture system can serve as a model to study the regulation of the expression of 3alpha-HSOR. We will establish that the 3alpha-HSOR expressed in intact brain is the enzyme expressed in our cultures; using molecular biology methodology. S.A. 2: to test the hypothesis that interleukin (IL) - 1 induces 3alphaDHP production by the aggregates. We will investigate the effect of IL-1 on steady state levels of 3alpha-HSOR mRNA and protein, and on enzyme activity. We will define the time course and dose dependency of IL-1 action and whether there is a critical time in culture during which IL-1 exerts its effect. These results will serve as the foundation for an extensive, full-scale proposal to elucidate the molecular mechanisms underlying cytokine regulation of 3alpha-HSOR expression in the brain. Hence, the results of these studies will provide new insight into the cellular and molecular mechanisms underlying cytokine actions and their role in the generation of neurological symptoms in HIV-infected people.