Title Page
Contents
ABSTRACT 10
I. INTRODUCTION 12
II. MATERIALS AND METHODS 17
2.1. Mouse model and primary cell isolation 17
2.2. Cell culture and transfection 18
2.3. OB differentiation 18
2.4. OC differentiation 19
2.5. Quantitative reverse transcription PCR (RT-qPCR) 19
2.6. Luciferase reporter assay 21
2.7. Micro-computed tomography (μCT) analysis and three-point bending test 21
2.8. Statistical analysis 21
III. RESULTS 22
3.1. E3 ligase-X KO mice showed enhanced trabecular bone thickness 22
3.2. E3 ligase-X KO mice showed enhanced trabecular bone strength 23
3.3. OB-related genes are upregulated in whole bone from E3 ligase-X KO mice 23
3.4. OC-related genes are downregulated in bone marrow from E3 ligase-X KO mice 24
3.5. E3 ligase-X KO mice showed altered RANKL/OPG ratio in whole bone and bone marrow 25
3.6. E3 ligase-X-null human BM-MSC showed increased OB differentiation 25
3.7. E3 ligase-X KO mouse BMMs showed decreased OC differentiation 26
3.8. Increased OB differentiation in E3 ligase-X KO mice is not rely on OB-OC coupling 26
3.9. E3 ligase-X KO mice showed increased bone regeneration against OVX-induced osteoporosis 27
3.10. β-catenin-dependent TCF/LEF promoter activity increased in E3 ligase-X-null cells 28
3.11. WNT/β-catenin signaling is not a major cause in OC differentiation in E3 ligase-X KO mice 29
IV. DISCUSSION 30
REFERENCES 50
ABSTRACT IN KOREAN 54
Figure 1. Enhanced trabecular bone thickness in E3 ligase-X KO mice 33
Figure 2. Improved femur bone strength in E3 ligase-X KO mice 34
Figure 3. Increased expression of OB-related gene in E3 ligase-X... 36
Figure 4. Decreased expression of OC-related gene in E3 ligase-X... 37
Figure 5. Altered RANKL/OPG ratio in E3 ligase-X KO mice 38
Figure 6. Increased OB differentiation in E3 ligase X-null human... 40
Figure 7. Decreased OC differentiation in E3 ligase-X KO mouse BMM 42
Figure 8. Increased OB differentiation in E3 ligase-X KO mice is... 44
Figure 9. Increased bone regeneration against OVX-induced... 46
Figure 10. E3 ligase-X deletion increased β-catenin dependent... 47
Figure 11. WNT/β-catenin signaling is not a major cause in OC... 48
Figure 12. Graphical summary of upregulated bone formation by... 49