인간 배아줄기세포-특이적 인자의 리간드를 이용한 세포 줄기성 조절
The regulation of stemness using the ligands of human ES cell-specific factor
- 주제(키워드) Embryonic stem cell , Stemness , Cell proliferation , GPCR
- 발행기관 아주대학교
- 지도교수 이명애
- 발행년도 2017
- 학위수여년월 2017. 8
- 학위명 석사
- 학과 및 전공 일반대학원 의생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000025646
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Human embryonic stem cells (hESC) have been regarded as promising resources for therapeutic uses with self-renewal property. Recent studies have discovered various transcription factors underlying stemness of hESCs. However, no membrane receptors related to stemness are known so far. We identified a novel GPCR protein HECAT5 as a candidate molecule regulating stemness using digital differential display (DDD). When we overexpressed HECAT5 in hNSC and HEK293 cells, it dramatically increased cell proliferation as well as S phase population. While investigating signaling pathway underlying the effect of HECAT5 in cell proliferation, we found that treatment of Gq protein inhibitor, YM254890, did not affect cell proliferation induced by HECAT5. Furthermore, the level of ERK and AKT which are downstream molecules of β-arrestin pathway did not change in HECAT5-overexpressed cells. Next, we aimed to identify ligands which may modulate HECAT5 activity. We found nonanoic acid which showed approximately 70% binding affinity to HECAT5 via ODORactor website. We observed that nonanoic acid increased cell proliferation, while there was no difference in ERK and AKT level, which means it is not HECAT5-specific ligand. Generally, GPCR goes through conformational change upon their activation and Toggle switch and Ionic lock are involved in this mechanism. Based on the fact that HECAT5 has both Toggle switch and ionic lock with highly conserved and candidate odors analyzed from reference dataset, we established the homology model of HECAT5. This results in approximately 140 candidate chemicals after screening various commercial chemical libraries. In this respect, we anticipate that HECAT5 activity modulators may play a role in increasing the efficiency of iPSC generation or in blocking certain type of cancer cells.
more목차
Ⅰ. INTRODUCTION 1
Ⅱ. MATERIAL AND METHOD 3
A. Digital differential display 3
B. RNA preparation/ Reverse transcription PCR 3
C. Molecular modeling 3
D. Cell culture 4
E. Cell proliferation assay 4
F. Western blot analysis after nonanoic acid treatment 4
G. Chemical preparation 5
Ⅲ. RESULTS 6
A. Identification of hESC-specific stemness factor, HECAT5 6
B. Characteristics of HECAT5 8
C. GPCRs general signaling pathway 9
D. Gαq inhibitor did not affect the cell proliferation induced by HECAT5 10
E. HECAT5-mediated cell proliferation might not be caused by β-arrestin-dependent way 11
F. Conformational changes of GPCR family during activation 12
G. Toggle switch and Ionic lock are important motifs to trigger GPCR signaling 13
H. Structural dynamics in olfactory receptor 14
I. Discovery of HECAT5 ligand via ODORactor program 16
J. Treatment of nonanoic acid increased cell proliferation 17
K. Identification of candidate odors to modulate HECAT5 activity 18
Ⅳ. DISCUSSION 20
Ⅴ. CONCLUSION 22
REFERENCES 23
국문요약 26
