Modulation of Acetylation in the Treatment of Lethal Injuries

 描述(申请人提供)：在平民和军事创伤中，出血和脑损伤是主要的死亡原因。目前的治疗方法大多是支持性的，并没有解决休克和损伤引起的特定细胞功能障碍。乙酰化正在迅速成为一种关键的表观遗传机制，它调节许多基因的表达(通过调节核组蛋白)，以及多种非核蛋白的功能。在NIH拨款R01GM84127的资助下，我们已经证明，使用非选择性组蛋白脱乙酰酶(HDAC)抑制剂(PAN-HDACi)治疗可以迅速激活关键机制，从而提高致命出血、败血症和复合侮辱动物模型的存活率。这些结果使我们能够启动由联邦政府资助的泛HDACi丙戊酸(ClinicalTrials.gov标识符NCT01951560)的I期临床试验。尽管令人兴奋，但由于需要非常大的剂量，非选择性HDACi的治疗并不是最佳的，这产生了巨大的毒性潜力。已知的18种HDAC异构体具有非常独特的作用、组织分布和生理功能，新的抑制剂具有更高的异构体选择性，因此更具疾病特异性。我们最近已经证明，在脓毒症模型中，使用异构体特异性HDACi(iso-HDACi)的治疗比PAN-HDACi更有效，初步数据表明，这可能也适用于其他致命的侮辱。然而，这一领域需要进一步的研究，因为适当的药物选择(S)是至关重要的，而抑制错误的HDAC可能是有害的。这项拟议的研究是我们之前工作的合理扩展，并将体内实验与细胞和分子分析相结合，以确定致命侮辱的新治疗方法，并为潜在机制提供重要的见解。长期目标：开发新的策略，将细胞损伤降至最低，并提高致命侮辱后的存活率。具体目标1：在啮齿动物模型中，测试在无并发症的致命性失血(无多发创伤)后给予等密度脂蛋白的有效性。具体目标2：确定在复苏方案中加入iso-HDACi是否会改善临床现实模型的结果，在这些模型中，失血性休克合并多器官损伤和多菌污染。具体目标3：确定在两个不同物种中，在不同的侮辱之后，iso-HDACi对多器官保护作用的主要机制。方法：我们的计划是进行一系列动物实验，以实现这三个具体目标。首先，我们将使用一个无并发症失血的啮齿动物模型来比较iso-HDACi和PAN-HDACi，并了解不同的iso-HDACi和其他细胞保护策略之间的相互作用。在这个模型中效果良好的策略将在出血、多发创伤和[多菌素污染(结肠损伤)]的临床现实猪模型中进一步得到验证。这些实验的组织将被用来在基因、蛋白质、新陈代谢和重要的细胞功能水平上阐明潜在的机制。

 DESCRIPTION (provided by applicant): Hemorrhage and brain injuries are the leading causes of death in civilian and military trauma. Current therapies are mostly supportive, and do not address the specific cellular dysfunction caused by shock and injuries. Acetylation is rapidly emerging as a key epigenetic mechanism that regulates the expression of numerous genes (by modulating nuclear histones), as well as the functions of multiple non-nuclear proteins. Funded by the NIH grant R01GM84127, we have demonstrated that treatment with non-selective histone deacetylase (HDAC) inhibitors (pan-HDACI) can rapidly activate key mechanisms that lead to improved survival in animal models of lethal hemorrhage, sepsis, and combined insults. These results have allowed us to start a federally funded phase-I clinical trial of a pan-HDACI, valproic acid (ClinicalTrials.gov identifier NCT01951560). Although exciting, treatment with non-selective HDACI is not optimal due to need for very large doses, which creates a significant potential for toxicities. The 18 known isoforms of HDAC have very distinctive roles, tissue distribution, and physiological functions, and newer inhibitors are more isoform selective, and thus more disease specific. We have recently shown that treatment with isoform specific HDACI (iso-HDACI) is more effective than pan-HDACI in septic models, and preliminary data suggest that this may also be true for other lethal insults. However, this area needs additional investigation because appropriate selection of the drug(s) is critically important, and inhibition f the wrong HDAC can be detrimental. The proposed research is a logical extension of our previous work, and combines in-vivo experiments with cellular and molecular assays to identify novel treatments for lethal insults, and to provide important insights into the underlying mechanisms. Long-term goal: Develop novel strategies to minimize cellular damage and improve survival after lethal insults. Specific aim 1: Test the effectiveness of iso-HDACIs when given after uncomplicated lethal blood loss (without poly-trauma) in a rodent model. Specific aim 2: Determine whether addition of iso-HDACI to resuscitation regimens would improve outcomes in clinically realistic models, where hemorrhagic shock is complicated by multiple organ injuries and polymicrobial contamination. Specific aim 3: Determine the dominant mechanisms that are responsible for the multi-organ protective effects of the iso-HDACI following diverse insults, in two different species. Approach: Our plan is to perform a series of animal experiments to address the 3 specific aims. First, a rodent model of uncomplicated blood loss will be used to compare the iso-HDACI to pan-HDACI, and to understand the interplay between various iso-HDACIs and other cytoprotective strategies. The strategies that work well in this model will then be further validated in a clinically realistic swine model of hemorrhage, poly-trauma, and [polymicrobial contamination (colon injury)]. Tissues from these experiments will be used to elucidate the underlying mechanisms at the level of genes, proteins, metabolism, and important cellular functions.