인체 멜라닌 세포에서 Wnt 조절인자인 sFRP2와 WIF-1의 색소형성에 대한 역할
Wnt Modulators, Secreted Frizzled Related Protein (sFRP) 2 and Wnt Inhibitory Factor (WIF)-1, Stimulate Melanogenesis in Normal Human Melanocytes
- 주제(키워드) sFRP2 , WIF-1 , Hyperpigmentary disorder , Melasma , Melanocytes , Skin pigmentation
- 발행기관 아주대학교
- 지도교수 강희영, 박태준
- 발행년도 2016
- 학위수여년월 2016. 8
- 학위명 박사
- 학과 및 전공 일반대학원 의생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000022841
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Wnt signaling plays a role in the differentiation as well as the development of melanocytes. Previous studies showed that hyperpigmentary skins of melasma express high levels of frizzled-related protein 2 (sFRP2) and Wnt inhibitory factor-1 (WIF-1) compared to perilesional normal skins. In this study, I investigated the functional roles of sFRP2 and WIF-1 on skin pigmentation. The present study demonstrated that sFRP2 and WIF-1 were expressed in both melanocytes of normal human skin and in cultured melanocytes, suggesting that these molecules may have physiologic functions in melanocytes as an auto- or paracrine modulator of Wnt signaling. In addition, I found that secreted frizzled-related protein 2 (sFRP2) was overexpressed in the hyperpigmentary skins of not only melasma but also solar lentigo and the acutely UV-irradiated skin in vivo. Therefore, I hypothesized that sFRP2 and WIF-1 could have stimulatory roles for skin pigmentation. As results, sFRP2 and WIF-1 stimulated melanogenesis in normal human melanocytes through the increased expression of MITF and tyrosinase via β-catenin signaling. Moreover, the epidermal pigmentation of human skin was also increased in the presence of recombinant human sFRP2 and WIF-1. These findings suggest that UV irradiation may stimulate sFRP2 and WIF-1 secretion in the skin, which functions as melanogenic stimulator. This may play an important role in the development of UV-induced hyperpigmentary disorders.
more목차
I. INTRODUCTION 1
II. MATERIALS AND METHODS 5
A. Cell culture 5
B. Biopsy collection 5
C. Ex vivo skin organ culture and pigmentation assay in cultured skin 6
D. Melanin content and tyrosinase activity assay 7
E. Lentivirus production 7
F. RNA interference 8
G. Real-time PCR and RT-PCR 8
H. Western blot analysis 10
I. Immunohistochemistry and confocal microscopic examination 11
J. Promoter analysis 12
K. Statistical analysis 12
III. RESULTS 13
A. Secreted Frizzled-related Protein 2 (sFRP2) Functions as a Melanogenic Stimulator 13
1. sFRP2 expression is increased in UV-induced hyperpigmented skins 13
2. sFRP2 expression in skin cells 17
3. sFRP2 increases pigmentation in human melanocytes 19
4. Fibroblast-derived sFRP2 induces pigmentation in melanocytes 22
5. sFRP2 did not affect the cell proliferation in normal human melanocytes and fibroblasts 25
6. sFRP2 stimulates β-catenin signaling in normal human melanocytes 27
7. Increased expression of sFRP2 induces β-catenin translocation into nucleus 30
8. sFRP2 did not activate β-catenin signaling in normal human fibroblasts 33
B. Stimulatory effect of Wnt inhibitory factor (WIF)-1on melanogenesis 35
1. WIF-1 expression in normal human skin and melanocytes 33
2. Effect of WIF-1 upregulation on melanogenesis in melanocytes 38
3. Effect of WIF-1 downregulation on melanogenesis in melanocytes 44
4. Fibroblast-derived WIF-1 induces pigmentation in melanocytes 47
5. WIF-1 act as an antagonist of Wnt/β-catenin signaling in normal human fibroblasts 50
IV. DISCUSSION 52
V. CONCLUSION 57
Ⅵ. REFERENCES 58
국문요약 65
