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.

项目概要 种植体周围炎是一种导致种植体周围软组织和骨骼破坏的炎症性疾病，仍然是一种常见的疾病 由于缺乏针对这种疾病的有效治疗策略，牙种植体存活的主要障碍。直到 最近，根据牙周病的观察，口腔细菌被认为是引发种植体周围炎的主要因素 疾病。然而，种植体周围疾病研究的重点已转向了解口腔免疫机制 它感知口腔中的外部信号并维持口腔微生物群的稳态。一井—— 口腔免疫监视的既定机制是脂多糖的 Toll 样受体 (TLR) 感应 (LPS)，一种内毒素，是革兰氏阴性菌的成分，在口腔中普遍存在。的监管 LPS/TLR4 轴，称为内毒素耐受，是维持口腔稳态的重要机制。 TLR4 激活触发信号级联，涉及多种细胞功能，包括免疫细胞 招募、产生反应氧（ROS）以中和入侵微生物以及促炎 细胞因子的分泌。 LPS/TLR4 轴在多个阶段受到多个负调节器的严格控制。 TLR4 信号级联可减轻不受控制的炎症，从而导致宿主组织破坏。期间 种植体周围炎症性疾病进展时，会出现过量的 ROS 水平，即氧化应激，从而破坏 细胞过程，包括 LPS/TLR4 信号传导的调节。 TLR4 负调节因子的抑制是 假设驱动 TLR4 在种植体周围炎中过度表达，从而增加对 LPS 的敏感性。钛 (Ti) 牙种植体表面的颗粒溶解会积聚在邻近的种植体周围组织中，并且 钛颗粒浓度的增加与种植体周围炎有关。然而，Ti 颗粒的作用 介导种植体周围疾病仍有待阐明。在这项拟议的研究中，植入物衍生的影响 探讨了钛颗粒 (iTiPs) 对过量 ROS 产生和随后 LPS/TLR4 轴失调的影响。 在目标 1 中，对含有钛颗粒的人类种植体周围炎影响的组织进行转录组分析 RNA 测序，同时重点研究 TLR4 信号传导、ROS 产生、其调节因子和 通过免疫组织化学评估促炎症细胞因子。在目标 2 中，人体周围的离体 Ti 颗粒 植入组织的特点是产生形态相似的 iTiP，然后对其进行诱导评估 体外单核细胞衍生的免疫细胞中ROS产生的影响。在目标 3 中，iTiPs 诱导的 ROS 能够 LPS/TLR4 信号传导失调、ROS 生成和促炎症状态通过基因表达进行评估 体外研究和成像流式细胞术以及体内小鼠口腔粘膜模型。该奖学金将帮助 申请人在生物材料、免疫学和口腔领域从事独立研究者的职业 重点关注 LPS/TLR4 信号传导的微生物组研究，以确定种植体周围的潜在治疗靶点 炎症性疾病治疗。该项目的成功完成将填补一个重要的知识空白 阐明 iTiP 的作用及其与氧化应激和 TLR4 信号传导在种植体周围炎中的相互作用。