Impact of Titanium-mediated Oxidative Stress on LPS/TLR4 Signaling

钛介导的氧化应激对 LPS/TLR4 信号传导的影响

• 批准号: 10827025
• 负责人: Danyal Siddiqui
• 金额: $ 6.99万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10827025
• 关键词: Affect; Automobile Driving; Bacteria; Binding; Biocompatible Materials; Bioinformatics; Biological Assay; Career Mobility; Cell physiology; Cells; Chronic; Complex; Cues; Data; Density Gradient Centrifugation; Dental Implants; Disease; Disease Progression; Endotoxins; Exposure to; Feedback; Fellowship; Flow Cytometry; Fluorescence Microscopy; Future; Gene Expression; Generations; Genes; Genetic Transcription; Gram-Negative Bacteria; Health; Homeostasis; Human; Image; Immune; Immune response; Immunohistochemistry; Immunologic Surveillance; Immunology; Implant; In Vitro; Inflammation; Inflammatory; Invaded; Knockout Mice; Knowledge; Laser Scanning Confocal Microscopy; Ligature; Link; Lipopolysaccharides; Macrophage; Maintenance; Mediating; Mediator; Metabolism; Microbe; Modeling; Molecular; Morphology; Mouth Diseases; Mucous Membrane; Mus; Myelogenous; Oral; Oral cavity; Oral mucous membrane structure; Oxidative Stress; Oxidative Stress Induction; Oxygen; Pathogen detection; Pathology; Pattern; Pattern recognition receptor; Periodontal Diseases; Periodontitis; Persons; Positioning Attribute; Production; Reaction; Reactive Oxygen Species; Receptor Signaling; Regulation; Research; Research Personnel; Role; Scanning Electron Microscopy; Signal Transduction; Signaling Protein; Site; Superoxides; Surface; TLR4 gene; Time; Tissue-Specific Gene Expression; Tissues; Titanium; Toll-like receptors; Transcriptional Regulation; Translations; Western Blotting; X ray spectroscopy; antagonist; bone; career; clinically relevant; cytokine; dysbiosis; effective therapy; implantation; in vivo; in vivo Model; microbial; microbiome research; monocyte; oral bacteria; oral microbiome; overexpression; particle; peri-implantitis; post-doctoral training; receptor; recruit; soft tissue; therapeutic target; transcriptome; transcriptome sequencing; translational study; treatment strategy

PROJECT SUMMARY Peri-implantitis, an inflammatory disease resulting in destruction of peri-implant soft tissue and bone, remains a major obstacle to dental implant survival due to a lack of effective treatment strategies for this disease. Until recently, oral bacteria were considered a primary factor triggering peri-implantitis as observed for periodontal diseases. However, peri-implant disease research has shifted focus to understanding oral immune mechanisms which sense external cues in the oral cavity and maintain homeostasis with the oral microbiome. One well- established mechanism of oral immune surveillance is Toll-like receptor (TLR) sensing of lipopolysaccharide (LPS), an endotoxin and component of gram-negative bacteria, ubiquitous in the oral cavity. The regulation of the LPS/TLR4 axis, known as endotoxin tolerance, is an important mechanism in maintaining oral homeostasis. TLR4 activation triggers signaling cascades involved with multiple cellular functions including immune cell recruitment, reaction oxygen species (ROS) generation to neutralize invading microbes, and proinflammatory cytokine secretion. The LPS/TLR4 axis is tightly controlled by multiple negative regulators at several stages of TLR4 signaling cascades which mitigate uncontrolled inflammation resulting in host tissue destruction. During peri-implant inflammatory disease progression, excess ROS levels, i.e., oxidative stress, occurs, which disrupts cellular processes including regulation of LPS/TLR4 signaling. Suppression of TLR4 negative regulators is hypothesized to drive TLR4 overexpression in peri-implantitis, thereby increasing sensitivity to LPS. Titanium (Ti) particle dissolution from a dental implant surface can accumulate in adjacent peri-implant tissue, and increasing concentrations of Ti particles are associated with peri-implantitis. However, the role of Ti particles in mediating peri-implant disease remains to be elucidated. In this proposed study, the impact of implant-derived Ti particles (iTiPs) on excess ROS production and subsequent dysregulation of the LPS/TLR4 axis is explored. In Aim 1, transcriptome analysis of human peri-implantitis-affected tissue containing Ti particles is performed via RNA sequencing, while focused gene translation study for TLR4 signaling, ROS production, their regulators, and proinflammation cytokines is assessed via immunohistochemistry. In Aim 2, ex vivo Ti particles in human peri- implant tissue are characterized to generate morphologically similar iTiPs, which are then assessed for induction of ROS production in monocyte-derived immune cells in vitro. In Aim 3, the ability of iTiPs-induced ROS to dysregulate LPS/TLR4 signaling, ROS generation, and proinflammatory status is evaluated via gene expression studies and imaging flow cytometry in vitro and a murine oral mucosal model in vivo. This fellowship will help the applicant pursue a career as an independent investigator in the field of biomaterials, immunology, and oral microbiome studies with a focus on LPS/TLR4 signaling to identify potential therapeutic targets for peri-implant inflammatory disease treatment. Successful completion of this project will fill a crucial knowledge gap by elucidating the role of iTiPs and its interaction with oxidative stress and TLR4 signaling in driving peri-implantitis.

项目摘要 种植体炎，一种炎症性疾病，导致植入物周围的软组织和骨骼破坏，仍然是 由于缺乏该疾病的有效治疗策略，牙科植入物生存的主要障碍。直到 最近，口腔细菌被认为是触发植入周期炎的主要因素，如牙周 疾病。但是，种植体疾病研究已转移到理解口服免疫机制上 在口腔中感觉到外部线索，并通过口腔微生物组维持体内平衡。一个 口服免疫监视的既定机制是脂多糖的Toll样受体（TLR）感应 （LPS），一种革兰氏阴性细菌的内毒素和成分，在口腔中无处不在。调节 LPS/TLR4轴被称为内毒素耐受性，是维持口服稳态的重要机制。 TLR4激活触发了与多个细胞功能有关的信号级联，包括免疫细胞 募集，反应氧（ROS）产生以中和入侵微生物和促炎性 细胞因子分泌。 LPS/TLR4轴在多个阶段的多个负调节器紧密控制 TLR4信号级联反应减轻不受控制的炎症，导致宿主组织破坏。期间 植入物周围炎症性疾病进展，过量ROS水平，即氧化应激，发生破坏 细胞过程，包括调节LPS/TLR4信号传导。 TLR4负调节剂的抑制是 假设可以驱动植入植入术的TLR4过表达，从而提高对LPS的敏感性。钛 （Ti）从牙科植入物表面溶解的颗粒可以在相邻的植入物组织中积聚，并且 Ti颗粒浓度的增加与植入周围炎有关。但是，Ti颗粒在 介导种植体疾病仍有待阐明。在这项拟议的研究中，植入物衍生的影响 探索了过量ROS产生的Ti颗粒（ITIP）和LPS/TLR4轴随后的失调。 在AIM 1中，通过通过人类周围炎感染的组织含有Ti颗粒的转录组分析。 RNA测序，同时针对TLR4信号传导，ROS产生，调节剂和 促炎细胞因子通过免疫组织化学评估。在AIM 2中，人周围的体内ti颗粒 植入组织的特征是生成形态上相似的ITIP，然后评估其诱导 单核细胞衍生的免疫细胞中ROS产生的体外。在AIM 3中，ITIP引起的ROS的能力 通过基因表达评估失调LPS/TLR4信号传导，ROS产生和促炎状态 研究和成像流式细胞仪体外和体内鼠口服粘膜模型。该奖学金将有助于 申请人从事生物材料，免疫学和口腔领域的独立研究者职业 微生物组研究的重点是LPS/TLR4信号传导，以鉴定植入物周围的潜在治疗靶标 炎症性疾病治疗。成功完成该项目将填补重要的知识差距 阐明ITIP的作用及其与氧化应激和TLR4信号传导的相互作用在驱动植入植入术中。