TNF/ANG II INTERACTIONS IN THE MTALH

描述：(改编自申请)本提案将调查 肿瘤坏死因子-a的产生机制 血管紧张素II(Ang II)的调节作用及对肿瘤坏死因子-Ang的影响 II大鼠髓质厚升支中离子输运的相互作用 亨勒氏环(MTALH)。证明肿瘤坏死因子是由 血管紧张素Ⅱ刺激后的mTALH可作为 确定该多肽的某些作用是否由 肿瘤坏死因子。MTALH在Ang II刺激下产生肿瘤坏死因子的机制 将使用细胞、分子和免疫化学方法来表征 (免疫荧光和免疫印迹)。这些实验将 揭示转录和转录后的贡献 血管紧张素Ⅱ诱导产生肿瘤坏死因子的机制，并将提供一个框架 围绕哪些策略可以设计出改变这些互动的策略。这个 肾素-血管紧张素系统与血管紧张素转换酶代谢产物的密切联系 花生四烯酸，以及这些激素系统可能的相互作用 肿瘤坏死因子提示涉及这三个因素的重要调控机制 不同类别的介质、细胞因子(TNF)、二十烷类化合物和 血管紧张素可能与肾脏的离子转运机制有关。 肿瘤坏死因子在血管紧张素转换酶II介导的前列腺素E_2合成增加中的作用 用抗肿瘤坏死因子抗血清中和肿瘤坏死因子生物活性测定， 和重组的肿瘤坏死因子受体融合蛋白。三个互补 技术(数字成像显微镜、膜片钳分析和86RB 传输)将用于评估血管紧张素转换酶对离子传输的影响。 MTALH。肿瘤坏死因子和前列腺素对此的调节能力 影响也将被确定。 基于这些考虑，本提案旨在测试 假设：1)血管紧张素Ⅱ是肿瘤坏死因子产生的内源性调节因子。 2)肿瘤坏死因子介导血管紧张素Ⅱ诱导的mTALH产生前列腺素 可能与诱导环氧合酶(COX-2)有关的调节作用； 3)血管紧张素Ⅱ释放的肿瘤坏死因子介导/调节血管紧张素转换酶的作用。 多肽对mTALH离子转运机制的研究。

DESCRIPTION: (Adapted from the application) This proposal will investigate the mechanisms by which production of tumor necrosis factor-a (TNF) is regulated by angiotensin II (Ang II), and determine the effects of TNF-Ang II interactions on ion transport in the medullary thick ascending limb of Henle's loop (mTALH). The demonstration that TNF is rapidly produced by the mTALH after stimulation with Ang II serves as a starting point for determining whether some effects of this peptide are mediated/modulated by TNF. The mechanisms by which the MTALH produces TNF in response to Ang II will be characterized using cellular, molecular, and immunochemical (immunofluorescence and Western blot) protocols. These experiments will reveal the contribution of transcriptional and post-transcriptional mechanisms to TNF production induced by Ang II, and will provide a framework around which strategies for altering these interactions can be devised. The close association of the renin-angiotensin system with metabolites of arachidonic acid, and the putative interactions of these hormonal systems with TNF suggest that important regulatory mechanisms involving these three distinct classes of mediators, cytokines (TNF), eicosanoids, and angiotensins, may have relevance to ion transport mechanisms in the kidney. The contribution of TNF to Ang II-mediated increases in PGE2 production will be determined by neutralization of TNF bioactivity with anti-TNF antisera, and a recombinant TNF receptor fusion protein. Three complementary techniques (digital imaging microscopy, patch-clamp analysis and 86 Rb transport) will be used to assess the effects of AngII on ion transport in the mTALH. The ability of TNF and prostanoids to mediate/modulate these effects also will be determined. Based on these considerations, this proposal is designed to test the hypotheses: 1) Ang II is an endogenous regulator of TNF production in the mTALH; 2)TNF mediates Ang II-induced prostanoid production in the mTALH, a regulatory action that may be linked to induction of cyclooxygenase (COX-2); and 3)TNF, released in response to Ang II, mediates/modulates the effects of the peptide on mTALH ion transport mechanisms.