2026-09-21T03:04:20Zhttps://repository.ajou.ac.kr/oai/request

oai:repository.ajou.ac.kr:201003/130342024-10-11T02:21:26Zcom_201003_14372com_201003_14368col_201003_14374

Wnt Modulators, Secreted Frizzled Related Protein (sFRP) 2 and Wnt Inhibitory Factor (WIF)-1, Stimulate Melanogenesis in Normal Human Melanocytes 인체 멜라닌 세포에서 Wnt 조절인자인 sFRP2와 WIF-1의 색소형성에 대한 역할 김, 미선 강, 희영 박, 태준 대학원 의생명과학과 110943 김, 미선 sFRP2 WIF-1 Hyperpigmentary disorder Melasma Melanocytes Skin pigmentation 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. 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 Doctor 2016-11-28 2016-11-28 2016 2016 Thesis Theses http://repository.ajou.ac.kr/handle/201003/13034 http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000022841 000000022841 en