A Protein Biologic for the Treatment of Sepsis

描述(由申请人提供)：败血症和相关的多器官功能障碍是死亡和发病的主要原因，在美国每年导致超过215,000人死亡。尽管对脓毒症的发病机制有了越来越多的了解，但治疗选择仍然主要局限于抗生素、糖皮质激素和支持性措施。广泛的共识是，线粒体功能障碍，即所谓的细胞病理性缺氧，在脓毒症的过程中发展，并成为该过程后期的特征。细胞病理性缺氧的特征是线粒体复合体I、ATP合成和氧耗受到可逆性抑制，从而导致免疫抑制和广泛的器官衰竭。实验操作，如增强线粒体生物发生的转录因子(如线粒体转录因子A，TFAM)的过表达，已被发现在脓毒症模型中有效，但缺乏适当强大的药理生物发生刺激物阻碍了临床应用。Gencia开发了一种重组形式的人TFAM(RhTFAM)，经过改造后可以穿越细胞屏障，并专门导入线粒体。注射后，rhTFAM进入所有组织的线粒体，作为转录因子，迅速(在数小时内)增加复合体I的活性、耗氧量、线粒体质量和最大ATP产量达150%，同时减少ROS的产生。用rhTFAM实现的线粒体生物发生刺激的幅度、速度和持久性比文献中描述的任何药物都要大。在行为上，接受重组人肿瘤坏死因子治疗的健康小鼠的跑步耐力(旋转潜伏期)增加了300%，即使在34个月大的小鼠身上，在长达10个月的剂量上也没有明显的副作用。初步的脂多糖脓毒症动物模型实验表明，重组人肿瘤坏死因子显著提高了小鼠的存活率。在这个第一阶段的SBIR项目中，我们将测试rhTFAM是否能够逆转在内毒素脓毒症模型中观察到的细胞病变缺氧。该项目的具体目标是：1)确定rhTFAM治疗是否改善了LPS攻击的HepG2和人原代肝细胞的炎症、线粒体功能和细胞死亡2)确定rhTFAM治疗是否改变了LPS攻击的C57/BL6小鼠的死亡率。证实rhTFAM在内毒素脓毒症模型中的有益作用将为在盲肠结扎和穿刺术(CLP)脓毒症模型中使用rhTFAM的第二阶段SBIR工作铺平道路。 公共卫生相关性： 根据这项建议实施的目标将显示重组人肿瘤坏死因子作为脓毒症治疗的可行性。败血症是对感染和其他严重应激源的一种全身性炎症反应，是ICU环境下的主要死亡原因，在美国每年导致215,000人死亡。尽管对脓毒症的发病机制有了越来越多的了解，但治疗选择仍然主要局限于抗生素、糖皮质激素和支持性措施。

DESCRIPTION (provided by applicant): Sepsis and related multiple organ dysfunction are a major cause of mortality and morbidity, responsible for over 215 000 deaths per year in the US. Despite growing understanding of the pathomechanism of sepsis, treatment options are still limited primarily to antibiotics, glucocorticoids, and supportive measures. There is wide consensus that mitochondrial dysfunction, so called cytopathic hypoxia, develops over the course of sepsis, and becomes the defining feature of the late stage of the process. Cytopathic hypoxia is characterized by a reversible suppression of mitochondrial complex I, ATP production and oxygen consumption which result in immunosuppression and widespread organ failure. Experimental manipulations, such as overexpression of transcription factors that enhance mitochondrial biogenesis (e.g. the mitochondrial transcription factor A, TFAM), have been found effective in models of sepsis but clinical applications are hampered by lack of suitably powerful pharmacological biogenesis stimulators. Gencia developed a recombinant form of human TFAM (rhTFAM), modified to allow it to traverse cellular barriers and to be specifically imported into mitochondria. After being injected rhTFAM enters mitochondria in all tissues examined so far and acts as a transcription factor, rapidly (within hours) increasing complex I activity, oxygen consumption, mitochondrial mass and maximum ATP output by up to 150%, while decreasing ROS production. The magnitude, speed and persistence of mitochondrial biogenesis stimulation achieved with rhTFAM are larger than with any pharmacological agents described in the literature. Behaviorally, healthy mice treated with rhTFAM increased running endurance (rotarod latency) by 300%, and there were no significant side-effects over up to 10 months of dosing even in mice aged 34 months. Preliminary LPS sepsis animal model experiments show significantly improved survival in mice treated with rhTFAM. In this Phase I SBIR project we will test whether rhTFAM is capable of reversing of the cytopathic hypoxia observed in an LPS model of sepsis. Specific aims of the project are: 1) Determine if rhTFAM treatment ameliorates inflammation, mitochondrial function, and cell death in HepG2 and human primary liver cells challenged with LPS 2) Determine whether rhTFAM treatment alters mortality in c57/bl6 mice challenged with LPS. Confirmation of a beneficial effect of rhTFAM in LPS models of sepsis would pave the way for Phase II SBIR work where rhTFAM would be used in the CLP (cecal ligation and puncture) model of sepsis. PUBLIC HEALTH RELEVANCE: The aims carried out under this proposal will show feasibility for rhTFAM as a treatment for Sepsis. Sepsis is a systemic inflammatory response to infection and other severe stressors, and is the leading cause of death in the ICU setting, responsible for 215,000 fatalities per year in the US. Despite growing understanding of the pathomechanism of sepsis, treatment options are still limited primarily to antibiotics, glucocorticoids, and supportive measures.