Arf6 Inhibition as Novel Treatment for Multidrug Resistance Gram Negative Infections

Arf6 抑制作为多重耐药革兰氏阴性菌感染的新疗法

基本信息

批准号：
9488843
负责人：
ASHRAF S. IBRAHIM
金额：
$ 45.71万
依托单位：
LUNDQUIST INSTITUTE FOR BIOMEDICAL INNOVATION AT HARBOR-UCLA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9488843
关键词：
Acinetobacter baumannii Affect Anabolism Anti-Bacterial Agents Antibiotic Resistance Antibiotic Therapy Antibiotics Bacillus (bacterium)Bacteremia Bacteria Binding Biological Assay Blood Vessels CD14 gene Cell-Matrix Junction Cells Cessation of life Colistin Communicable Diseases Complex Data Development Dose Drug resistance Edema Effectiveness Endothelial Cells Endotoxemia Extravasation Foundations Frequencies GTP Binding Generations Genes Goals Gram-Negative Bacteria Guanosine Triphosphate Phosphohydrolases Healthcare Systems Host Defense Mechanism Immune response In Vitro Incidence Infection Infection prevention Inflammation Inflammatory Intercellular Junctions Interleukin-1 beta Interleukin-6 Klebsiella pneumonia bacterium Knockout Mice Laboratories Lead Lipid A Lipopolysaccharides Mediating Methods Modeling Monomeric GTP-Binding Proteins Morbidity - disease rate Multi-Drug Resistance Mus NF-kappa B Neutrophil Infiltration Nosocomial Infections Organ failure Pathogenesis Pathway interactions Patients Permeability Phagocytes Pharmacology Phase I Clinical Trials Pneumonia Process Pseudomonas aeruginosa Research Resistance Rodent Role Sepsis Septicemia Serum Shock Signal Transduction Small Interfering RNA TLR4 gene TNF gene Testing Tissues Toxic effect Toxicology Vascular Endothelium Vascular Permeabilities Virulence bacterial resistance cadherin 5 carbapenem resistance carbapenemase cytokine efficacy testing extensive drug resistance falls global health histopathological examination immune activation improved in vitro activity in vivo inhibitor/antagonist killings liquid chromatography mass spectrometry mortality mouse model multi-drug resistant pathogen multidrug-resistant Pseudomonas aeruginosa novel outcome forecast peptide analog preclinical development preclinical toxicity prevent public health relevance small molecule inhibitor tigecycline

项目摘要

DESCRIPTION (provided by applicant): Multi-drug resistant (MDR) organisms due to Gram negative bacilli (GNB) have become endemic in healthcare systems throughout the world. Of great concern is the recent, remarkable rise in the frequency of extremely drug resistant (XDR)-A. baumannii (AB) infections which increased >17 fold in the last decade. Further, infections with AB are surpassing those caused by Pseudomonas aeruginosa (PA), another MDR GNB, the incidence of which has remained stable across the US. Bloodstream infections caused by XDR AB have >60% mortality rates. Clearly new methods to prevent and treat AB and other MDR GNB are needed. Septicemia is a common manifestation of AB and other GNB infections which is caused by the endotoxic bacterial lipopolysaccharide (LPS) through binding to TLR4. LPS recognition by TLR4 triggers a potent and protective inflammatory cytokine immune response via the MyD88/NF-kB cascade. However, this immune response can often lead to a harmful and frenetic process associated with excess vascular leak that leads to tissue edema, organ failure, shock, and death. We found TLR4 deficient mice to be resistant to AB infection. Consistent with these findings, disruption of LPS synthesis in AB (with LpxC inhibitors affecting lipid A biosynthesis) renders the bacterium totally avirulent in mice despite the lack of in vitro activity of these inhibitors against the bacterium. Recent research by Dr. Dean Li (CSO of Navigen) demonstrated that the excess vascular leak seen in LPS-triggered septicemia is caused by the small GTPase Arf6 which falls in the MyD88/ARNO/Arf6 pathway and functions independently from the MyD88/NF-kB cascade. Arf6 induces vascular endothelium leak via intracellular internalization of VE-cadherin which leads to cell-to-cell junction disruption. We hypothesize that AB bacteremia (and other GNB infections) often fail antibiotic therapy because LPS induces excess vascular leak that results in edema and organ failure. Also, the pharmacological inhibition of Arf6 provides an opportunity to retain the beneficial inflammatory immune response, trigged by TLR4 recognizing LPS, without the added harmful vascular leak. Indeed our preliminary results showed promising activity of one of the Arf6 inhibitors in the mouse model of AB infection. We propose to build on these exciting data to delineate the role of MyD88/ARNO/Arf6 in the pathogenesis of AB infections via siRNA gene inhibition, peptide analogues and knockout mice. Further, we will determine the activity of 2nd generation improved Arf6 inhibitors in treating murine AB infections. Achieving these two goals (R21 aims) will identify 2 lead Arf6 inhibitors for detailed PK/PD and toxicology studies. Finally, we will determine the breadth of activity of these 2 inhibitors against other GNB infections including MDR PA and Klebsiella pneumonia carbapenemase (KPC) in mice (R33 aims). Conclusion of our studies will lay the foundation for further development of Arf6 inhibitors as viable new class of antibiotics versus GNB infections including GMP, GLP preclinical toxicity, and IND filing.

描述（由适用提供）：由于革兰氏阴性杆菌（GNB）引起的多药耐药（MDR）生物已成为全球医疗保健系统的内在。最令人关注的是，最近耐药性（XDR）-a的频率最近显着上升。在过去的十年中，鲍曼尼（AB）感染增加了> 17倍。此外，AB的感染超过了由铜绿假单胞菌（PA）引起的，这是另一个MDR GNB，其事件在整个美国一直保持稳定。由XDR AB引起的血液感染的死亡率> 60％。显然，需要新的预防和治疗AB和其他MDR GNB的方法。败血病是AB和其他GNB感染的常见表现，是由内毒性细菌脂多糖（LPS）通过与TLR4结合而引起的。 TLR4识别的LPS识别通过MyD88/NF-KB级联反应触发潜在的炎症细胞因子免疫反应。但是，这种免疫反应通常会导致与过量血管泄漏有关的有害和疯狂的过程，从而导致组织水肿，器官衰竭，休克和死亡。我们发现TLR4缺乏小鼠对AB感染具有抗性。与这些发现一致，AB中LPS合成的破坏（与脂质A生物合成的LPXC抑制剂有关）使细菌完全无毒的小鼠造成了这些抑制剂对细菌的体外活性。 Dean Li博士（Navigen的CSO）的最新研究表明，在LPS触发的败血症中看到的过量血管泄漏是由小的GTPase ARF6引起的，该ARF6属于MyD88/Arno/arf6途径，并且与MyD88/NF-KB级别的独立起作用。 ARF6通过VE-钙粘着蛋白的细胞内内在化诱导血管内皮泄漏，从而导致细胞对细胞连接破坏。我们假设AB细菌（和其他GNB感染）经常失败抗生素治疗，因为LPS会诱导过多的血管渗漏，从而导致水肿和器官衰竭。同样，ARF6的药理抑制作用提供了保留有益的炎症免疫响应的机会，这是由TLR4识别LPS触发的，而没有增加有害血管泄漏的情况。实际上，我们的初步结果显示了AB感染小鼠模型中ARF6抑制剂之一的活性。我们建议建立这些令人兴奋的数据，以描述MyD88/Arno/arf6在通过siRNA基因抑制，肽类似物和敲除小鼠通过AB感染的发病机理中的作用。此外，我们将确定第二代改善ARF6抑制剂在治疗鼠AB感染中的活性。实现这两个目标（R21 Aims）将确定2种详细的PK/PD和毒理学研究的铅ARF6抑制剂。最后，我们将确定这两种抑制剂对其他GNB感染的活动广度，包括小鼠MICE的MDR PA和Klebsiella Carbapenemase（KPC）（R33 AIMS）。我们的研究的结论将为ARF6抑制剂的进一步发展作为可行的新型抗生素与GNB感染（包括GMP，GMP，GLP临床前毒性和IND归档）的基础。