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：
9089918
负责人：
ASHRAF S. IBRAHIM
金额：
$ 19.71万
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 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9089918
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 Data Development Dose Drug resistance Edema Effectiveness Endothelial Cells Endotoxemia Extravasation Foundations Frequencies GTP Binding Generations Genes Goals Gram-Negative Bacteria Guanosine Triphosphate Phosphohydrolases Health Healthcare Systems Hospitals Host Defense Mechanism Immune response In Vitro Incidence Infection Infection prevention 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 Organ failure Pathogenesis Pathway interactions Patients Permeability Phagocytes 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 Tissue Survival 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 pre-clinical preclinical toxicity prevent 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（由申请人提供）：由革兰氏阴性杆菌 (GNB) 引起的多重耐药 (MDR) 微生物已成为全世界医疗保健系统中的流行病，最近令人担忧的是极度耐药 (GNB) 的发生频率显着上升。 XDR)-A. 鲍曼不动杆菌 (AB) 感染在过去十年中增加了 17 倍以上。此外，AB 感染超过了另一种 MDR 铜绿假单胞菌 (PA) 引起的感染。 GNB 在美国各地的发病率保持稳定，其死亡率超过 60%，显然需要新的方法来预防和治疗 AB 和其他 MDR GNB 败血症是 AB 和其他疾病的常见表现。 GNB 感染是由内毒素细菌脂多糖 (LPS) 通过 TLR4 与 TLR4 识别结合引起的，通过 MyD88/NF-kB 触发有效的保护性炎症细胞因子免疫反应。然而，这种免疫反应常常会导致与过度血管渗漏相关的有害且疯狂的过程，从而导致组织水肿、器官衰竭、休克和死亡，这与这些一致。研究发现，AB 中 LPS 合成的破坏（LpxC 抑制剂影响脂质 A 生物合成）使该细菌在小鼠体内完全无毒，尽管这些抑制剂缺乏体外抗 A 型细菌的活性。 Dean Li 博士（Navigen 的 CSO）最近的研究表明，LPS 引发的败血症中出现的过度血管渗漏是由位于 MyD88/ARNO/Arf6 通路中的小 GTPase Arf6 引起的，并且独立于 MyD88/Arf6 发挥作用。 NF-kB 级联通过 VE-钙粘蛋白的细胞内内化诱导血管内皮渗漏，从而导致细胞间连接。我们承认 AB 菌血症（和其他 GNB 感染）通常会导致抗生素治疗失败，因为 LPS 会导致过度的血管渗漏，从而导致水肿和器官衰竭。此外，Arf6 的药理抑制提供了保留触发的有益炎症免疫反应的机会。事实上，我们的初步结果表明，其中一种 Arf6 抑制剂在 AB 感染小鼠模型中具有良好的活性，我们建议以这些令人兴奋的数据为基础来描述。通过 siRNA 基因抑制、肽类似物和敲除小鼠，MyD88/ARNO/Arf6 在 AB 感染发病机制中的作用此外，我们将确定第二代改进的 Arf6 抑制剂在治疗小鼠 AB 感染中的活性（R21 目标）。）将鉴定 2 种主要的 Arf6 抑制剂，用于详细的 PK/PD 和毒理学研究。最后，我们将确定这 2 种抑制剂针对其他 GNB 感染的活性广度，包括。小鼠中的 MDR PA 和肺炎克雷伯菌碳青霉烯酶 (KPC)（R33 目标）将为 Arf6 抑制剂的进一步开发奠定基础，作为对抗 GNB 感染的可行的新型抗生素，包括 GMP、GLP 临床前毒性和 IND 申请。