NITRIC OXIDE AND INSULIN IN ISLET TRANSPLANTATION

胰岛移植中的一氧化氮和胰岛素

• 批准号: 6177536
• 负责人: CHARLES D MILLS
• 金额: $ 20.74万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-15 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6177536
• 关键词: RNase protection assay; autologous transplantation; blood glucose; cell type; diabetes mellitus; flow cytometry; gene targeting; genetically modified animals; homologous transplantation; hypoglycemia; insulin; laboratory mouse; laboratory rat; macrophage; nitric oxide; nitric oxide synthase; pancreatic islet transplantation; tissue /cell culture; transplant rejection; transplantation immunology

The goal of this investigation is to increase the success of clinical islet transplantation. Two interrelated hypotheses are put forth to achieve this goal. First, Nitric Oxide (NO) is postulated to be a prime mediator of islet dysfunction. Second, a previously unrecognized ability of insulin to decrease NO production is proposed to explain its islet-protective activity. Both of these hypotheses will be tested directly by focusing the experiments in this investigation on the use of inducible Nitric Oxide Synthase "knockout" mice (iNOS-/-). Specific Aim I will determine the role of macrophage NO in islet graft rejection. Based on preliminary and published results from this laboratory, NO is proposed to inhibit islets in 2 "waves": an early wave that occurs 1-2 days posttransplant of syngeneic or allogeneic islets is responsible for early islet dysfunction. A second wave NO-mediated islet dysfunction is proposed to occur during classical allograft rejection. The early wave will be investigated by comparing syngeneic islet function in diabetic iNOS-/- and iNOS-/+ mice; the second wave will be investigated using allogeneic islets in these hosts. Inhibitors of NO will then be used to determine how to best increase islet function. Preliminary and published evidence from this laboratory suggests that inhibiting NO in a clinically applicable way does increase the success of islet transplantation. Islets will be implanted in the intraperitoneal cavity in this investigation because intragraft NO production and allograft rejection responses can readily be followed at this site. Mice will be the primary species used because, like humans, they are "low" producers of NO; rats will be used in selected experiments because of their larger size. Specific Aim II will determine the mechanism by which insulin promotes islet function. A dominant paradigm has been that insulin allows transplanted beta-cells to "rest". However, preliminary evidence indicates that insulin administration to diabetic mice or rats decreases macrophage iNOS mRNA expression and NO production. Therefore, specific experiments will again compare iNOS- /- and iNOS-/+ mice to directly test the hypothesis that the islet- protective activity of insulin results from decreasing NO production. Finally, hyperglycemic clamps will be employed to maintain hyperglycemia in order to determine if the islet-protective activity of insulin depends on its ability to lower blood glucose. The results of this investigation should provide important new information that will increase the success of clinical islet transplantation as well as providing basic information on what role NO plays in rejection of cell transplants, and how NO production is regulated by insulin.

这项研究的目标是提高临床胰岛的成功率 移植。 提出两个相互关联的假设来实现 这个目标。 首先，假设一氧化氮 (NO) 是素数 胰岛功能障碍的介质。 第二，以前不认识的 胰岛素减少 NO 产生的能力被提出来解释其 胰岛保护活性。 这两个假设都将得到检验 直接通过将本研究中的实验集中于使用 诱导型一氧化氮合酶“敲除”小鼠（iNOS-/-）。 具体的 目的 I 将确定巨噬细胞 NO 在胰岛移植中的作用 拒绝。 根据初步和已发布的结果 实验室中，NO 被提议在 2 个“波”中抑制胰岛：早期波 同基因或同种异体胰岛移植后 1-2 天发生的情况是 负责早期胰岛功能障碍。 第二波NO介导 胰岛功能障碍被认为发生在经典同种异体移植过程中 拒绝。 早期浪潮将通过比较同基因进行研究 糖尿病 iNOS-/- 和 iNOS-/+ 小鼠的胰岛功能；第二波 将使用这些宿主中的同种异体胰岛进行研究。 抑制剂 然后，NO 将用于确定如何最好地增加胰岛功能。 该实验室的初步和已发表的证据表明 以临床适用的方式抑制 NO 确实会增加成功率 胰岛移植。 胰岛将被植入腹膜内 本研究中的空洞是因为移植物内 NO 的产生和 在该位点可以容易地追踪同种异体移植排斥反应。 小鼠 将是主要使用的物种，因为像人类一样，它们是“低等”的 NO 的生产者；大鼠将被用于选定的实验，因为 它们的尺寸较大。 具体目标 II 将通过以下方式确定机制： 哪种胰岛素可以促进胰岛功能。 一个占主导地位的范式是 胰岛素可以让移植的β细胞“休息”。 然而， 初步证据表明，糖尿病患者服用胰岛素 小鼠或大鼠降低巨噬细胞 iNOS mRNA 表达和 NO 生产。 因此，具体实验将再次比较iNOS- /- 和 iNOS-/+ 小鼠直接检验胰岛-的假设 胰岛素的保护活性是由于 NO 产生减少而产生的。 最后，将采用高血糖钳来维持 高血糖以确定胰岛保护活性是否 胰岛素取决于其降低血糖的能力。 结果 这项调查应该提供重要的新信息 提高临床胰岛移植的成功率并提供 NO 在细胞排斥中起什么作用的基本信息 移植，以及胰岛素如何调节 NO 的产生。

项目成果

Insulin down-regulates the inducible nitric oxide synthase pathway: nitric oxide as cause and effect of diabetes?

• DOI: 10.4049/jimmunol.159.11.5329
• 发表时间: 1997-12
• 期刊: Journal of immunology
• 影响因子: 4.4
• 作者: R. Stevens;D. Sutherland;J. Ansite;M. Saxena;T. Rossini;B. Levay-Young;B. Hering;C. Mills

Augmentation of an antitumor CTL response In vivo by inhibition of suppressor macrophage nitric oxide.

• DOI: 10.4049/jimmunol.163.11.5877
• 发表时间: 1999-12
• 期刊: Journal of immunology
• 影响因子: 4.4
• 作者: Marianne Medot-Pirenne;M. Heilman;Malinee Saxena;Patricia E. McDermott;Charles D. Mills