비만마우스의 지방염증에 대한 시간제한식이의 중단 효과

다국어 초록 (Multilingual Abstract)

Obesity is a growing problem in modern society. As the obesity epidemic grows, dietary interventions such as time-restricted feeding (TRF) have been widely studied. TRF is a form of eating pattern that doesn't restrict calorie intake, but instead restricts the timing of meals. It has been shown to be effective in treating obesity, diabetes, liver disease, and more. However, there is a lack of research on whether the effects of TRF persist after discontinuation. In this study, we analyzed changes in body weight, dietary intake, fasting blood glucose and insulin, insulin resistance, liver and adipose tissue weight, and inflammatory gene expressions in adipose tissue after discontinuation of TRF in obese mice. To test this, six-week-old C57BL/6J mice were randomized into low-fat diet and high-fat diet ad libitum groups for a total of 6 weeks to induce obesity. The high- fat diet ad libitum group was then divided into three groups: the HFD- AL group, which maintained the high-fat diet ad libitum; the HFD- TRF group, which initiated daily 10 h-TRF regimen; and the HFD- TRF/AL group, which initiated TRF and stopped after 4 weeks of TRF. Results showed that the weight gain suppression, decreased energy efficiency, and improved fasting insulin, adiposity, and hepatomegaly seen during TRF with a high-fat diet were partially maintained at 2 weeks of discontinuation, but mostly disappeared after 3 weeks. Taken together, the results suggest that TRF is the most effective when applied consistently, and that some of the benefits could persist after discontinuation. Furthermore, discontinuation does not further increase metabolic risk compared to the obese control group. However, this study was conducted in male mice only, and mice on a low-fat diet could be different, which needs to be confirmed in a future study. * A thesis for the degree of Master in February 2024.

목차 (Table of Contents)

• Ⅰ. 서 론 1
• Ⅱ. 이론적 배경 4
• 1. 비만과 염증 4
• 2. 시간제한식이의 대사적 효과 7
• 3. 시간제한식이의 면역학적 효과 15
• Ⅲ. 연구재료 및 방법 17
• 1. 실험동물 및 식이 17
• 2. 실험설계 19
• 3. 체중 및 식이 섭취량 측정 22
• 4. 혈당 및 인슐린 농도 측정 23
• 5. 지방 조직학적 분석 및 세포 크기 분석 24
• 6. 지방 조직 유전자 발현 분석 26
• (1) RNA 추출 27
• (2) cDNA 합성 28
• (3) 실시간 역전사 중합효소 연쇄반응(Real Time-PCR) 28
• 7. 통계분석 31
• Ⅳ. 결과 및 고찰 32
• 1. 체중 32
• 2. 체중 변화량 35
• 3. 식이 및 에너지 섭취량과 에너지 효율비 37
• 4. 공복 혈당 및 인슐린 농도 변화 39
• 5. 지방 조직 무게 43
• 6. 간 조직 무게 47
• 7. 부고환 지방세포 면적 49
• 8. 지방조직 내 면역세포 관련 유전자 발현 52
• 9. 지방조직 내 전염증성 사이토카인 및 케모카인 유전자 발현 55
• 10. 지방조직 내 PPAR 유전자 발현 57
• Ⅴ. 요약 및 결론 60
• Ⅵ. 참고문헌 64