TNF/ANG II INTERACTIONS IN THE MTALH

描述：（改编自应用程序）本提案将调查 肿瘤坏死因子-a（TNF）的产生机制是 调节血管紧张素II（Ang II），并确定TNF-Ang II对延髓粗升支离子转运的相互作用 亨利氏环（mTALH）。 证明TNF是快速产生的 用Ang II刺激后的mTALH用作以下的起始点： 确定该肽的一些作用是否由以下物质介导/调节： 的tnf MTALH对Ang II产生TNF的机制 将使用细胞、分子和免疫化学 （免疫荧光和Western印迹）方案。 这些实验将 揭示了转录和转录后 血管紧张素II诱导的TNF产生的机制，并将提供一个框架 可以围绕它设计出改变这些相互作用的策略。 的 肾素-血管紧张素系统与 花生四烯酸，以及这些激素系统的假定相互作用 与TNF的关系表明，涉及这三个方面的重要调节机制 不同类别的介质，细胞因子（TNF），类花生酸， 血管紧张素可能与肾脏中的离子转运机制有关。 TNF对Ang II介导的PGE 2产生增加的作用将 通过用抗TNF抗血清中和TNF生物活性来测定， 和重组TNF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86 Rb 运输）将用于评估AngII对离子运输的影响， mTALH。 TNF和前列腺素类介导/调节这些的能力 效果也将确定。 基于这些考虑，本提案旨在测试 假设：1）Ang II是TNF产生的内源性调节剂， mTALH; 2）TNF介导Ang II诱导的mTALH中前列腺素样物质的产生， 可能与诱导环氧合酶（考克斯-2）有关的调节作用; 和3）响应于Ang II而释放的TNF介导/调节 肽对mTALH离子转运机制的影响。

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.