혈관신생촉진인자 COMP-Ang1의 항파골세포, 항염증반응 및 골분화 활성 효과 및 기전에 관한 연구

다국어 초록 (Multilingual Abstract)

COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), has been considered as a therapeutic agent enhancing tissue regeneration with increased angiogenesis, as well as inducing the homing of stem cells. However, the nature of COMP-Ang1 in inhibiting inflammatory responses, stimulating osteoclastic or osteoblastic differentiation, and inducing migration of stem-like cells are not completely understood. The therapeutic efficacy of COMP-Ang1 to suppress inflammatory periodontium damage and the related mechanisms are not also entirely elucidated. This study initially investigated how COMP-Ang1 affects lipopolysaccharide (LPS)-induced osteoclastic differentiation of RAW 264.7 macrophages. The addition of COMP-Ang1 decreased significantly osteoclast differentiation and activation in the cells and this decrease was almost completely restored by combined treatment with 25 μM LY294002, a pharmacological phosphatidylinositol 3-kinase (PI3K) inhibitor. COMP-Ang1 also blocked the expression of inflammation-related molecules, such as cyclooxygenase 2 (COX-2), intercellular adhesion molecule 1 (ICAM-1), and interleukin-8 (IL-8) in LPS-stimulated human periodontal ligament fibroblasts (hPLFs). In addition, the COMP-Ang1 enhanced differentiation of hPLFs into osteoblasts along with increased alkaline phosphatase (ALP) activity and intracellular calcium accumulation. Additional experiments revealed that COMP-Ang1-mediated osteoblastogenesis was correlated with the increased expression of bone-specific markers including runt-related transcription factor 2, osterix, bone morphogenetic protein 2, bone sialoprotein, osteoclacin, osteopontin, type I collagen, and ALP, as well as activator protein-1 subfamily and Tie2. The addition of COMP-Ang1 induced in vitro migration of bone marrow-mesenchymal stem cells (BMMSCs) and this migration was significantly suppressed by Tie2 knockdown and by supplementation with CXCR4-specific peptide antagonist (AMD3100) or PI3K inhibitor (LY294002), but not with p-p38 mitogen-activated protein kinase inhibitor (SB203580). Otherwise, this study also explored whether a local delivery of COMP-Ang1 protects LPS/ligature-induced periodontal destruction in rats. As the results, μCT and histological analyses exhibited that COMP-Ang1 inhibits LPS-mediated degradation of periodontal tissues and suppresses osteoclast number and the expression of osteoclast-specific and inflammation-related molecules (cathepsin-K, matrix metalloproteinase 9, COX-2, IL-8, tumor necrosis factor-α, and ICAM-1) in the inflamed region of periodontitis rats. Collectively, the current findings confirm that COMP-Ang1 contains a therapeutic potential capable of preventing inflammatory periodontal damages, as well as stimulating bone healing process via its potentials able to inhibit osteoclastic activation and inflammatory response along with its stimulating capacity for osteogenic differentiation and migration of progenitor cells or stem-like cells.

목차 (Table of Contents)

• CONTENTS 1
• LIST OF FIGURE LEGENDS 2
• LIST OF TABLES 4
• LIST OF ABBREVIATIONS 5
• ABTRACT 7
• I. INTRODUCTION 10
• II. MATERIALS AND METHODS 27
• III. RESUTLS 33
• IV. DISCUSSION 46
• V. CONCLUSIONS 57
• VI. REFERENCES 58
• VII. ABSTRACT IN KOREAN 70