비알콜성 지방간염에서 NLRP3 인플라마좀과 pyroptosis 에 대한 S IRT 1 의 역할 = SIRT1 Inhibits NLRP3 Inflammasome Activation and Pyroptosis in Nonalcoholic Steatohepatitis

다국어 초록 (Multilingual Abstract)

Saturated fatty acid (SFA) exposure causes nonalcoholic steatohepatitis (NASH). Inflammation is the leading cause of pathologies of nonalcoholic fatty liver disease, containing NASH. However, it is uncertain how SFA induces inflammation. Increasing evidence has demonstrated that caspase-1 activation and pyroptosis contribute to the development of NASH. In addition, we found that SIRT1 activity was associated with palmitic acid-induced elevation of NLRP3 inflammasome, attenuating caspase-1 expression, and reducing LDH release, and apoptosis. Interestingly, ROSA26-Cre; SIRT1fl/fl (exon 4) conditional knockout contributed to liver damage due to NLRP3 inflammasome, caspase-1 expression, LDH release, and pyroptotic cell death. The human liver cancer cell line HepG2 cells were exposed to palmitic acid (PA). Cells also induced NLRP3 inflammasome or GSDMD/pyroptosis during PA treatment for 24 hours. Thus, ROSA26-Cre; SIRT1fl/fl (exon 4) conditional knockout mouse displayed hyperactivated NLRP3 inflammasome, which resulted in hyperactivation of inflammasomes and increased mortality in NASH models. These findings define a unique regulatory mechanism of NLRP3 inflammasome activation from GSDMD/pyroptosis.

목차 (Table of Contents)

• ABSTRACT 1
• CONTENTS 2
• LIST OF FIGURES 4
• ABBREVIATIONS 5
• 1. Introduction 6
• 2. Materials and methods 8
• 2.1. Reagents 8
• 2.2. Animal 8
• 2.3. Cell culture and treatment 8
• 2.4. Viral production and plasmids 9
• 2.5. Immunoblot 9
• 2.6. Quantitative Real-Time PCR 9
• 2.7. LDH assay 10
• 2.8. Statistical analysis 11
• 3. Results 12
• 3.1. SIRT1 is associated with pyroptosis during NASH in mouse liver tissue. 12
• 3.2. In PA-treated HepG2 cells, SIRT1 is associated with pyroptosis activity. 14
• 3.3. SIRT1 knockdown in HepG2 cells increases PA-induced pyroptosis. 15
• 3.4. NLRP3 inflammasome activity is increased during NASH in mouse liver tissue. 17
• 3.5. SIRT1 knockdown in HepG2 cells elevated NLRP3 inflammasome activity. 18
• 3.6. Pyroptotic cell death in SIRT1 knockdown HepG2 cells is NLRP3 inflammasome dependent. 20
• 3.7. SIRT1 knockout of mouse liver tissue during NASH exacerbates pyroptosis. 21
• 3.8. SIRT1 knockout of mouse liver tissue during NASH increases NLRP3 inflammasome activity. 24
• 3.9. SIRT1 knockout of mouse liver tissue during NASH aggravates fibrosis and inflammation. 25
• 4. Discussion 27
• 5. Conclusion 29
• 6. References 30