Diversity Supplement; Impact of aging on intracellular ceramide-mediated periodontal bone lesions

多样性补充；

• 批准号: 9984735
• 负责人: Alexandru Movila
• 金额: $ 9.63万
• 依托单位: NOVA SOUTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9984735
• 关键词: Affect; Age; Aging; Alveolar Bone Loss; Apoptosis; Attenuated; Biological Assay; Biomedical Research; Cathepsins B; Cell Aging; Cell fusion; Cell membrane; Cells; Ceramides; Cytoplasm; Development; Down-Regulation; Elderly; Escherichia coli; Event; Foundations; High Mobility Group Proteins; Hispanic-serving Institution; Hydrolase; In Vitro; Inflammatory; Lesion; Lipids; Mediating; Mediator of activation protein; Molecular; Nonmuscle Myosin Type IIA; Pathogenicity; Periodontal Diseases; Periodontitis; Periodontium; Population; Porphyromonas gingivalis; Proteolysis; Reporting; Research Project Grants; Role; Signal Transduction; Societies; TNFSF11 gene; Testing; Time; Universities; Up-Regulation; Vertebrates; Wild Type Mouse; age related; aged; aging population; base; bone; bone loss; galactosylgalactosylglucosylceramidase; graduate student; in vivo; interest; mouse model; non-muscle myosin; novel therapeutic intervention; osteoclastogenesis; promoter; response; senescence; undergraduate student

ABSTRACT A paradigm-shift in immunogerontology has been occurring by finding that TLR signal is attenuated in elders, suggesting that an alternative pro-inflammatory mechanism may be engaged in the age-associated periodontitis. Ceramides that compose the cell membrane of vertebrates are attracting interests as signaling mediators in a variety of cell events, including, apoptosis and cell senescence. We recently reported that intracellular ceramides promote osteoclastogenesis by acting on a non-muscle myosin IIA (Myh9), an intracellular down-regulatory factor for cell fusion event in osteoclastogenesis. On the othernhad, it was recently demonstrated that intracellular ceramides directly act on cathepsin B to activate its catalytic activity. It is known that cathepsin B promotes RANKL-mediated osteoclastogenesis via temporally controlled proteolysis of Myh9 for initiation of cell fusion. In response to aging, the amount of ceramides increases in the cytoplasm of cells in conjunction with the diminished level of acid ceramidases (aCDase), a lipid hydrolase that degrades ceramides. Our preliminary results indicate that high mobility group protein B1 (HMGB1), a key senescence-associated proinflammatory mediator, downregulated aCDase expression in Raw264.7 cells. Based on these lines of evidence, we hypothesize that in the context of age associated periodontitis, where the LPS-induced signaling appears to be diminished, HMGB1 increases intracellular ceramides to advance OC-mediated bone loss by acting on cathepsin B, a promoter of osteoclastogenesis. In this R15 project, the Specific Aim 1 will establish the role of HMGB1 in accumulation of intracellular ceramide of senescence OCPs via downregulation of aCDase activity. We will compare the role of HMGB1 and LPS isolated from either Porphyromonas gingivalis or Escherichia coli relative to the downregulation of aCDase activity and resulting accumulation of ceramides in cytoplasm of OCPs of young (two month-old) and aged (twenty four month-old) wild type mice, both in vitro osteoclastogenesis assays and in in vivo mouse model of periodontitis. In Specific Aim 2, we will investigate the impact of intracellular ceramides on cathepsin B-dependent upregulation of osteoclastogenesis. We will evaluate the effects of intracellular ceramides on upregulation of cathepsin B’s catalytic activity that induce cells fusion event in osteoclastogenesis via Myh9 proteolysis in vitro. The proposed research project will, for the first time, investigate the possible pathogenic role of intracellular ceramide in age-dependently elevated osteoclastogenesis and will provide a foundation for the development of novel therapeutic approach for periodontitis in aging population. The most importantly, the proposed R15-AREA project will provide a unique opportunity for undergraduate and graduate students to participate in the biomedical researches at one of the largest academic Hispanic-serving institutions of Nova Southeastern University.

抽象的 通过发现TLR信号在长老中衰减，已经发生了免疫结肠的范式迁移。 表明可能会参与与年龄相关的牙周炎。 组成脊椎动物细胞膜的神经酰胺吸引了兴趣作为信号介质 各种细胞事件，包括凋亡和细胞感应。我们最近报道了细胞内神经酰胺 通过作用于非肌肉肌球蛋白IIA（MYH9），促进破骨细胞生成，这是一种细胞内下调节性的 破骨细胞发生中细胞融合事件的因子。在其他哈德上，最近证明了 细胞内神经酰胺直接作用于组织蛋白酶B，以激活其催化活性。众所周知，组织蛋白酶B 通过暂时控制的MYH9促进RANKL介导的破骨细胞生成来启动细胞 融合。响应衰老，神经酰胺的量增加了细胞的细胞质与 酸神经酰胺酶（ACDase）的水平降低，这是一种降解神经酰胺的脂质水解酶。我们的初步 结果表明，高迁移率蛋白B1（HMGB1），一种与钥匙相关的促炎性 介体，在RAW264.7细胞中下调的ACDase表达。基于这些证据，我们 假设在与年龄相关的牙周炎的背景下，LPS诱导的信号似乎是 减少的HMGB1增加了细胞内神经酰胺，以通过在组织蛋白酶上作用于OC介导的骨质流失 B，破骨细胞生成的启动子。在这个R15项目中，具体目标1将确定HMGB1在 通过下调ACDase活性，累积了感应OCP的细胞内神经酰胺。我们将 比较从牙龈卟啉单胞菌或大肠杆菌相对的HMGB1和LPS的作用 下调ACDase活性并导致神经酰胺在OCP的细胞质中积累 （两个月大）和年龄（二十四个月大的）野生型小鼠，包括体外破骨细胞生成测定法和 体内牙周炎模型。在特定的目标2中，我们将研究细胞内神经酰胺的影响 在整蛋白蛋白酶B依赖性的破骨细胞生成上的上调。我们将评估细胞内的影响 神经酰胺在组织蛋白酶B的催化活性上的上调，该催化活性诱导细胞融合事件在破骨细胞发生中 通过MYH9蛋白水解体外。拟议的研究项目将首次研究可能 细胞内神经酰胺在年龄依赖性升高的破骨细胞生成中的致病作用，并将提供 开发新型牙周炎的新型牙周炎的基础。最多 重要的是，拟议的R15地区项目将为本科和研究生提供独特的机会 学生参加最大的西班牙裔学术服务机构之一的生物医学研究 诺瓦东南大学。