TAZ 활성제로 알려진, TM-25659가 고지방 식이로 유도된 인슐린 저항성 마우스에 미치는 효과
Protective effect of TM-25659, known as TAZ activator, on high-fat diet-induced insulin resistance in C57BL/6J mice
- 주제(키워드) TAZ , TM-25659 , insulin resistance , FGF21 , AMPK
- 발행기관 아주대학교
- 지도교수 이관우
- 발행년도 2016
- 학위수여년월 2016. 2
- 학위명 박사
- 학과 및 전공 일반대학원 의생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000021474
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
2-butyl-5-methyl-6-(pyridine-3-yl)-3-[2'-(1H-tetrazole-5-yl)-biphenyl-4-ylmethyl]-3H-imidazo[4,5-b]pyridine] (TM-25659), known as the TAZ activator, inhibits adipocyte differentiation by interacting with peroxisome proliferator-activated receptor gamma (PPAR-γ). TM-25659 was previously shown to decrease weight gain in a high fat (HF) diet induced obesity (DIO) mouse model. However, the fundamental mechanisms underlying the effects of TM-25659 remain unknown. Therefore, we investigated the molecular mechanisms underlying the contribution of TM-25659 on palmitate (PA)-induced insulin resistance in both C2 myotubes and HepG2 cells. TM-25659 improved the PA-induced insulin resistance in C2 myotubes. TM-25659 induced expression of FGF21 mRNA and protein and secretion of FGF21 in C2 myotubes via activation of GCN2 pathways (GCN2-phosphor-eIF2α-ATF4 and FGF21). This effect of TM-25659 was diminished by FGF21 siRNA. Furthermore, TM-25659 improved the PA-induced insulin resistance in HepG2 cells. TM-25659 induced activation of AMPK in HepG2 cells. This beneficial effect of TM-25659 was diminished by AMPK inhibitor, compound C. Additionally, we studied the effects of TM-25659 on HF-diet induced insulin resistance in C57BL/6J mice. C57BL/6J mice were fed a HF-diet for 6 weeks. The HF group was randomly divided into two groups for the next 8 weeks: HF and HF+TM-25659. The HF+TM-25659-treated mice showed improvements in their obesity, fasting blood glucose and insulin levels, serum lipid levels, glucose homeostasis, insulin sensitivity, insulin resistance, and inflammation, but food intake was not affected. TM-25659 increased expressions of both FGF21 mRNA and protein on HF-diet induced insulin resistance in C57BL/6J mice muscle. Also, TM-25659 induced activation of AMPK protein on HF-diet induced insulin resistance in C57BL/6J mice liver. These data indicate TM-25659 may be beneficial for treating insulin resistance by inducing FGF21 and AMPK activation in models of PA-induced insulin resistance and HF-diet induced insulin resistance.
more목차
PART 1. TM-25659-induced activation of FGF21 level decreases insulin resistance and inflammation in skeletal muscle via GCN2 pathways 1
Ⅰ. INTRODUCTION 2
Ⅱ. MATERIALS AND METHODS 8
A. MATERIALS 9
B. METHODS 10
1. Preparation of PA 10
2. Cell culture 10
3. Immunoblot analysis 11
4. RNA isolation and quantitative real-time polymerase chain reaction (PCR) 12
5. siRNAs 13
6. Uptake of 2-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino-2-deoxyglucose (2-NBDG) 14
7. Animal experiments 14
8. FGF21 secretion 15
9. IL-1β assay 15
10. Statistical analysis 15
Ⅲ. RESULTS 16
A. TM-25659 restored PA-induced insulin resistance and inflammation in skeletal muscle cells 17
B. TM-25659 increased FGF21 levels by GCN2 pathways in skeletal muscle cells 22
C. Effects of TM-25659 reduced insulin resistance and inflammation in skeletal muscle cells treated with or without FGF21 siRNA 27
D. TM-25659 prevented HF-diet induced obesity 31
E. TM-25659 restored the insulin signaling pathways in DIO mice skeletal muscle 33
F. TM-25659 lowered the muscle pro-inflammatory cytokine levels in DIO mice 35
G. TM-25659 regulates expression of both FGF21 mRNA and protein in DIO mice skeletal muscles 37
Ⅳ. DISCUSSION 38
Ⅴ. CONCLUSION 42
PART 2. Protective effects of TM-25659 on high-fat diet-induced insulin resistance in liver via AMPK pathways 44
Ⅰ. INTRODUCTION 45
Ⅱ. MATERIALS AND METHODS 52
A. MATERIALS 53
B. METHODS 54
1. Preparation of PA 54
2. Cell culture 54
3. Immunoblot analysis 54
4. RNA isolation and quantitative real-time polymerase chain reaction (PCR) 55
5. Animal experiments 56
6. Insulin tolerance tests 57
7. Glucose tolerance tests 57
8. Statistical analysis 57
Ⅲ. RESULTS 58
A. TM-25659 restored PA-induced reduction of insulin signaling pathway and induction of in flammation in HepG2 cells 59
B. TM-25659 increased AMPK and ACC phosphorylation in HepG2 cells 62
C. TM-25659 reduced PA-induced reduction of insulin signaling pathway in HepG2 cells 65
D. TM-25659 reduced PA-induced reduction of inflammation in HepG2 cells 67
E. TM-25659 improved glucose homeostasis and insulin sensitivity in DIO mice 69
F. TM-25659 restored the insulin signaling pathways in DIO mice liver 71
G. TM-25659 lowered the serum and liver pro-inflammatory cytokine levels in DIO mice 73
H. TM-25659 activated AMPK pathways in DIO mice liver 77
I. TM-25659 repressed serum lipid levels in HF-diet fed mice 79
J. TM-25659 prevented HF-diet induced hepatic steatosis 81
K. TM-25659 reduced expression of lipogenic genes but increased expression of fatty acid oxidation genes in HF diet-fed mice 83
Ⅳ. DISCUSSION 85
Ⅴ. CONCLUSION 88
REFERENCES 90
국문요약 108
