Role and function of prohibitin in intestinal inflammation

描述(由申请人提供)： Prohibitin是一种高度保守的蛋白质，具有多效性，这取决于它表达的细胞和组织类型。关于禁止素在肠道中的表达和功能，人们知之甚少。在我的博士后研究期间，我证明了1)禁止素在天然的人结肠上皮细胞以及模型肠上皮细胞中都有表达，2)在静止的肠上皮细胞中，禁止素定位于线粒体，并且可以防止氧化应激，3)禁止素在氧化应激过程中下调，包括在活动性人类炎症性肠病(IBD)和实验性结肠炎期间，以及4)禁止素转基因小鼠免受DSS和鼠伤寒沙门氏菌诱导的结肠炎和氧化应激的影响。在评估禁止素调节炎症的机制时，我们的初步数据表明，禁止素是Nrf2的有效激活剂，Nrf2是一种主要的转录调节因子，激活一系列抗氧化基因。此外，我们最近的体外数据表明，禁止素可以抑制肿瘤坏死因子-1诱导的核因子-B的激活和屏障功能障碍。基于这些数据，这一建议的中心假设是，禁止素作为一种上皮防御功能，对抗氧化应激和炎症诱导的屏障功能障碍，而IBD中禁止素水平的降低有助于组织损伤和炎症。该提案的总体目标是确定禁止素在结肠炎中保护作用的潜在机制。我们基于我们的假设并得到初步数据支持的相互关联但独立可实现的目标是：i)确定禁止素调节Nrf2的作用和机制，ii)探讨禁止素抑制NF-2(B信号及其下游效应)的机制，以及iii)确定禁止素共同缓解结肠炎的体内机制，这些研究将阐明禁止素作为抗氧化剂激活剂和作为肠上皮细胞中抗炎分子的功能和作用机制。候选人将通过执行拟议的研究学习蛋白质生物化学和电生理学方面的培训，这将提高过渡到独立的IBD研究人员的潜力。 公共卫生相关性： 这项研究建议确定禁止素在预防氧化应激、核因子-B激活和屏障功能障碍方面的功能和机制，这些都是肠道炎症的标志。这些研究旨在为禁止素作为预防肠道炎症后果的潜在治疗靶点提供证据。

DESCRIPTION (provided by applicant): Prohibitin is a highly conserved protein that has pleiotropic functions depending on the cell and tissue type in which it is expressed. Little is known regarding the expression and function of prohibitin in the intestine. During my postdoctoral fellowship I demonstrated that 1) prohibitin is expressed by native human colonic epithelia as well as model intestinal epithelial cells, 2) in resting intestinal epithelial cells, prohibitin localizes to the mitochondria and protects against oxidative stress, 3) prohibitin is downregulated during oxidant stress, during active human inflammatory bowel disease (IBD) and experimental colitis, and 4) prohibitin transgenic mice are protected from DSS- and Salmonella typhimurium-induced colitis and oxidative stress. In assessing the mechanism by which prohibitin modulates inflammation, our preliminary data demonstrate that prohibitin is a potent activator of Nrf2, a master transcriptional regulator that activates a battery of anti-oxidant genes. In addition, our recent in vitro data demonstrate that prohibitin inhibits TNF(-induced NF-(B activation and barrier dysfunction. Based on these data, the central hypothesis of this proposal is that prohibitin functions as an epithelial defense against oxidative stress and inflammation-induced barrier dysfunction and decreased levels of prohibitin in IBD contribute to tissue injury and inflammation. The overall objective of the proposal is to determine the mechanism underlying the protective role of prohibitin in colitis. Our interrelated yet independently achievable aims based on our hypothesis and supported by preliminary data are i) to determine the role and mechanism by which prohibitin modulates Nrf2, ii) to address the mechanism of prohibitin in inhibiting NF-(B signaling and its downstream effects, and iii) to determine the in vivo mechanism by which prohibitin ameliorates colitis Together, these studies will elucidate the function and mechanism of action of prohibitin as an activator of anti-oxidants and as an anti-inflammatory molecule in intestinal epithelial cells. The training in protein biochemistry and electrophysiology the candidate will learn from executing the proposed studies will improve potential for transition to an independent IBD researcher. PUBLIC HEALTH RELEVANCE: This study proposes to define the function and mechanism of prohibitin in protecting against oxidative stress, NF-(B activation and barrier dysfunction, which are hallmarks of intestinal inflammation. These studies are designed to provide evidence for prohibitin as a potential therapeutic target to prevent the consequences of intestinal inflammation.