Mechanism of ITAM Signal Regulation in Osteoclasts

破骨细胞ITAM信号调控机制

• 批准号: 7906881
• 负责人: Mary Beth Humphrey
• 金额: $ 25.46万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-10 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7906881
• 关键词: Actins; Acute; Affect; Alveolar Bone Loss; Antibodies; Bacteria; Biological Assay; Bone Resorption; Bone remodeling; Cells; Chimeric Proteins; Chronic; DNA polymerase epsilon stimulatory factor 1; Data; Deposition; Development; Disease; Dose; Equilibrium; Exhibits; Goals; Human; ITAM; IgE Receptors; Immune; In Vitro; Inflammation; Inflammatory; Integrins; Lead; Life; Ligands; Lipids; Mediating; Mission; Mus; Myelogenous; Myeloid Cells; Osteoblasts; Osteoclasts; Osteopenia; Osteoporosis; Pathway interactions; Periodontal Diseases; Periodontitis; Phosphoric Monoester Hydrolases; Phosphotransferases; Porphyromonas gingivalis; Protein Tyrosine Kinase; Protein Tyrosine Phosphatase; Proteins; Regulation; Regulatory Pathway; Role; Signal Pathway; Signal Transduction; TNFSF11 gene; TYROBP gene; Therapeutic Intervention; adapter protein; base; bone; human disease; in vivo; inositol-1,4,5-trisphosphate 5-phosphatase; insight; macrophage; migration; myo-inositol-1 (or 4)-monophosphatase; novel; novel therapeutic intervention; osteoclastogenesis; receptor; response; src Homology Region 2 Domain; triggering receptor expressed on myeloid cells 2 protein, human

DESCRIPTION (provided by applicant): Bone integrity is maintained via the careful balance of bone deposition by osteoblasts and bone resorption by osteoclasts (OC). Bone remodeling occurs throughout life and imbalances in formation and resorption lead to human diseases including osteoporosis and periodontitis, a mission of the agency. We are studying the negative regulation of ITAM-adapter signals in osteoclasts. Specifically we are investigating the possibility that phosphatases may regulate ITAM-adapter, DAP12, signaling. We have found a novel association of activated DAP12 with SH2-containing inositol-5'-phosphatase 1 (SHIP1). Our central hypothesis is that SHIP1 regulates DAP12 signaling during OC development and function in vitro and in vivo. Specific Aim 1: Determine the mechanism by which SHIP1 inhibits DAP12 signaling. These studies aim to determine the functional domains of SHIP1 that are required for inhibition of DAP12 signaling, the role of proximal kinases, and the specific downstream signaling pathways negatively regulated by SHIP1. We will determine the role of SHIP1 in negatively regulating DAP12 downstream of MCSF, RANKL, and integrin stimulation. We will investigate the specific role of DAP12-associated receptors in mediating SHIP1- DAP12 association. Specific Aim 2: Determine how SHIP1 inhibition of DAP12 signaling affects the OC functions of resorption, actin ring formation and survival in vitro. We will determine the cellular localization of SHIP1 and DAP12 during DAP12 stimulation. Specific Aim 3: Determine the affect of SHIP1 on DAP12 signaling in vivo. We will determine whether SHIP1 regulates DAP12 signaling in vivo after direct activation of DAP12 with anti-TREM2 antibodies or blockade of DAP12 with TREM2-fusion protein. Specific Aim 4: Determine the role of SHIP1 and TREM2/DAP12 in response to Porphyromonas gingivalis (P. gingivalis) induced alveolar bone loss. Additionally we will investigate the roles of DAP12 and SHIP1 in inflammatory trabecular and alveolar bone loss induced by chronic low dose LPS treatment or acute stimulation with P. gingivalis LPS in vivo. These studies will not only elucidate how SHIP1 regulates DAP12 signaling in OC but will potentially give insights into how DAP12 can function as both an activating and inhibitory signal in macrophages and OC. This understanding might lead to novel therapeutic interventions in periodontal disease and osteoporosis. Project Narrative: The aim of proposed studies is to define a key regulatory pathway needed to inhibit activity of osteoclasts, cells that dissolve bone. This understanding might lead to novel therapeutic interventions in chronic periodontal disease and osteoporosis, diseases associated with excessive osteoclast activity.

描述（由申请人提供）：通过整骨细胞和骨骼吸收骨骼的骨骼沉积来维持骨完整性（OC）。骨骼重塑发生在整个生命中，形成和吸收导致人类疾病，包括骨质疏松症和牙周炎，这是该机构的任务。我们正在研究破骨细胞中ITAM-apapter信号的负调节。具体而言，我们正在研究磷酸酶可以调节ITAM-AUPAPTER DAP12，信号传导的可能性。我们发现了活化的DAP12与含SH2的Inositol-5'-磷酸酶1（Ship1）的新型关联。我们的中心假设是Ship1在体外和体内OC发育和功能过程中调节DAP12信号传导。特定目标1：确定Ship1抑制DAP12信号传导的机制。这些研究旨在确定抑制DAP12信号传导，近端激酶的作用以及由Ship1负调节的特定的下游信号通路所需的Ship1功能域。我们将确定Ship1在对MCSF，RANKL和整联蛋白刺激下游的DAP12负调节中的作用。我们将研究与DAP12相关受体在介导船舶1- DAP12关联中的特定作用。具体目标2：确定Ship1抑制DAP12信号传导如何影响吸收，肌动蛋白环形成和体外生存的OC功能。我们将在DAP12刺激过程中确定Ship1和Dap12的细胞定位。具体目标3：确定Ship1对体内DAP12信号传导的影响。我们将确定使用抗Treem2抗体直接激活DAP12后，Ship1在体内调节DAP12信号传导，或用TREM2-融合蛋白的DAP12进行阻断。具体目标4：确定Ship1和Trem2/Dap12对卟啉牙（牙龈疟原虫）诱导肺泡骨损失的作用。此外，我们将研究DAP12和Ship1在慢性低剂量LPS​​治疗或用体内用牙龈疟原虫LPS急性刺激引起的炎症小梁和肺泡骨质流失中的作用。这些研究不仅将阐明Ship1如何调节OC中的DAP12信号传导，而且有可能深入了解DAP12如何在巨噬细胞和OC中充当激活和抑制信号。这种理解可能会导致牙周疾病和骨质疏松症的新治疗干预措施。项目叙述：拟议研究的目的是定义抑制破骨细胞活性的关键调节途径，即溶解骨骼的细胞。这种理解可能会导致慢性牙周疾病和骨质疏松症，与过度骨细胞活性相关的疾病。