PPARgamma and PPARgamma agonists in septic shock

描述（由申请方提供）：在美国，每年有超过750，000例患者发生重度脓毒症，是重症监护室发病率和死亡率的主要原因。细菌产物对促炎细胞的激活导致炎性介质的释放，从而诱导脓毒症的全身炎症反应。这些介质的产生在转录水平上由增强子元件核因子κ B（NF-κ B）和激活蛋白-1（AP-1）通过与特异性激酶的相互作用来调节。在初步的体外和体内研究中，我们已经获得了脓毒症的全身炎症反应可能是由核报告基因过氧化物酶体增殖物激活受体-γ（PPAR γ）反调节的证据。用特异性PPAR γ配体15脱氧-δ 12，14-PGJ 2（15 d-PGJ 2）或噻唑烷二酮曲格列酮预处理巨噬细胞抑制由细菌脂多糖（LPS）和热灭活金黄色葡萄球菌（HK S. aureus)具有良好的抗菌活性。与该发现一致，我们发现PPAR γ配体提高了盲肠结扎和穿刺诱导的脓毒性休克大鼠的存活率，减少了血流动力学改变，细胞因子产生和肺、结肠和肝脏中的中性粒细胞浸润。我们的中心假设是核受体PPAR γ是一个关键的抗炎途径，PPAR γ的激活对感染性休克有益。三个相互关联的具体目标将检验这一假设。(1)我们将在体内评估PPAR γ配体对多种微生物脓毒症期间心血管紊乱和器官衰竭的治疗效果。15 d-PGJ 2、噻唑烷二酮和非噻唑烷二酮PPAR γ配体对脓毒症后遗症的作用将在进行盲肠结扎和穿刺的大鼠中进行体内检测。(2)我们将确定PPAR γ配体在体内多微生物脓毒症中作用的分子机制。将检测PPAR γ配体对NF-κ B和AP-1及其调节激酶的核活化的作用。(3)我们将确定环戊烯前列腺素和PPAR γ在调节巨噬细胞/单核细胞体外LPS和HK S刺激的细胞信号传导和炎症介质产生中的作用。金黄色。该方法将使用PPAR γ的药理学拮抗剂和PPAR γ显性/阴性构建体和来自Cre-lox小鼠的PPAR γ缺陷型巨噬细胞的遗传操作。体内和体外方法的组合将提供PPAR γ活化在脓毒症中有益的假设的强有力的检验。

DESCRIPTION (provided by applicant): Severe sepsis occurs in over 750,000 patients each year in the United States and is the leading cause of morbidity and mortality in critical care units. Activation of pro-inflammatory cells by bacterial products leads to a release of inflammatory mediators that induces the systemic inflammatory response of sepsis. The production of these mediators is regulated at the transcriptional level by enhancer elements nuclear factor kappaB(NF-kappaB) and activator protein-1 (AP-1) through interactions with specific kinases. In preliminary in vitro and in vivo studies we have obtained evidence that the systemic inflammatory response of sepsis may be counter-regulated by the nuclear reporter peroxisome proliferator activated receptor-gamma (PPARgamma). Pretreatment of macrophages with the specific PPARgamma ligands 15deoxy-delta12,14-PGJ2 (15d-PGJ2) or the thiazolidinedione troglitazone inhibits pro-inflammatory mediators induced by bacterial lipopolysaccharide (LPS) and heat killed Staphylococcus aureus (HK S. aureus). Consistent with this finding, we have found that PPARgamma ligands improve survival, reduce hemodynamic alterations, cytokine production and neutrophil infiltration in lung, colon and liver in rats subjected to septic shock induced by cecal ligation and puncture. Our central hypothesis is that the nuclear receptor PPARgamma is a critical anti-inflammatory pathway and that PPARgamma activation is beneficial in septic shock. Three interrelated specific aims will test this hypothesis. (1) We will evaluate the therapeutic efficacy of PPARgamma ligands on cardiovascular derangement and organ failure during polymicrobial sepsis in vivo. The effects of 15d-PGJ2, thiazolidinediones and nonthiazolidinedione PPARgamma ligands on septic sequelae will be examined in vivo in rats subjected to cecal ligation and puncture. (2) We will identify the molecular mechanisms of the actions of PPARgamma ligands in polymicrobial sepsis in vivo. The effect of PPARgamma ligands on nuclear activation of NF-kappaB and AP-1 and their regulatory kinases will be examined. (3) We will determine the role of cyclopentencne prostaglandins and PPARgamma in regulating cell signaling and inflammatory mediator production in macrophages/monocytes challenged in vitro with LPS and HK S. aureus. This approach will employ pharmacologic antagonists of PPARgamma and genetic manipulations with PPARgamma dominant/negative constructs and PPARgamma deficient macrophages from Cre-lox mice. The combination of in vivo and in vitro approaches will provide a strong test of the hypothesis that activation of PPARgamma is beneficial in sepsis.