CYTOKINES AND STEROID ENZYME EXPRESSION IN BRAIN

细胞因子可以解释许多临床和组织病理。 在艾滋病患者的大脑中的发现。我们的长期目标是 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，一些细胞因子诱导的 神经症状可能是伽玛激活的结果 氨基丁酸(GABA)受体复合体。激活GABAA 受体导致的神经症状类似于其中的一些 艾滋病患者表现出的焦虑、嗜睡和运动 功能障碍。此外，细胞因子可以像GABA激动剂一样发挥作用，因为它们 诱导止痛。因为GABA是体内主要的抑制性神经递质 由于GABA受体在大脑中广泛分布 大脑中，细胞因子对受体的异常激活可能会广泛影响 大脑功能的范围。我们的工作假设是细胞因子诱导 神经系统症状的部分原因是GABA受体的激活。 而这种激活是通过增加 GABA受体配体3α-羟基的胞外浓度- 5α-二氢孕酮(3α-DHP)。我们的研究重点是3alphaDHP， 因为它是一种非常有效的GABAA受体的配体和激活剂 因为它是在大脑中产生的。我们最近实施了一个 分离培养表达胎儿脑细胞的优化培养体系 几种类固醇代谢酶，包括3α-羟基类固醇 氧化还原酶(3α-HSOR)，催化形成 3AlphaDHP。S.A.1：验证聚合培养系统可以 作为研究3α-HSOR表达调控的模型。 我们将确定在完整的大脑中表达的3α-HSOR是 在我们的文化中表达的酶；使用分子生物学方法。 S.A2：检验白细胞介素1诱导3alphaDHP的假说 按集合体生产。我们将研究IL-1对血管内皮细胞生长的影响 3α-HSOR mRNA和蛋白的稳态水平及其对酶的影响 活动。我们将确定IL-1的时间进程和剂量依赖关系 在培养过程中是否存在IL-1的关键时间 发挥它的作用。这些结果将作为 广泛的、全面的建议来阐明分子机制 3α-HSOR在脑内表达的潜在细胞因子调控。 因此，这些研究的结果将为我们提供对 细胞因子作用的细胞和分子机制及其机制 在艾滋病毒感染者的神经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.