Cheol Hwan Myung1, Kyuri Kim2, Jong Il Park1, Ji Eun Lee1, Jeong Ah Lee1, Sung Chan Hong1, Kyung-Min Lim3, Jae Sung Hwang4. 1. Department of Genetic Engineering & Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Gyeonggi-do, Republic of Korea. 2. College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea. 3. College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea. Electronic address: kmlim@ewha.ac.kr. 4. Department of Genetic Engineering & Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Gyeonggi-do, Republic of Korea. Electronic address: jshwang@khu.ac.kr.
Abstract
BACKGROUND: Rab27a, Mlph, and MyoVa form a tripartite complex and relate to melanosome distribution. Melanophilin (Mlph) acts as a linker protein between Rab27a and MyoVa. The biological activity and function of 16-kauren on the expression of Mlph has not yet been studied. OBJECTIVE: We examined the effect of 16-kauren on melanosome transport and skin pigmentation. METHODS: Murine Melan-a melanocytes and SP-1 keratinocytes were used for in vitro analysis. Western blot analysis, quantitative real-time polymerase chain reaction, luciferase assay and immunohistochemical staining in 3D pigmented human skin model were performed. RESULTS: We found that 16-kauren inhibits melanosome transport in Melan-a melanocytes without affecting melanin synthesis. Treatment with 16-kauren reduced melanophilin (Mlph), a key protein in melanosome transport, in Melan-a melanocytes, at both the protein and mRNA levels while it did not affect the expression of Rab27a and MyoVa, the other two key proteins for melanosome transport. Notably, the expression of melanogenic proteins, including tyrosinase, trp1, trp2, and MITF, was not affected by 16-kauren. However, 16-kauren attenuated melanosome distribution in co-culture of Melan-a melanocytes and SP-1 keratinocytes as well as in Melan-a monolayer culture. In further confirmation of the depigmenting effects of 16-kauren on Melanoderm™, a 3D pigmented human skin model, treatment with 16-kauren for 12 days increased the brightness of the tissue as determined by lightness value and reduced the distribution of melanosomes as shown in histological examination. CONCLUSION: These results demonstrated that 16-kauren is a selective modulator of a melangenic target, Mlph expression, and can be employed as a new depigmenting strategy.
BACKGROUND:Rab27a, Mlph, and MyoVa form a tripartite complex and relate to melanosome distribution. Melanophilin (Mlph) acts as a linker protein between Rab27a and MyoVa. The biological activity and function of 16-kauren on the expression of Mlph has not yet been studied. OBJECTIVE: We examined the effect of 16-kauren on melanosome transport and skin pigmentation. METHODS:Murine Melan-a melanocytes and SP-1 keratinocytes were used for in vitro analysis. Western blot analysis, quantitative real-time polymerase chain reaction, luciferase assay and immunohistochemical staining in 3D pigmented human skin model were performed. RESULTS: We found that 16-kauren inhibits melanosome transport in Melan-a melanocytes without affecting melanin synthesis. Treatment with 16-kauren reduced melanophilin (Mlph), a key protein in melanosome transport, in Melan-a melanocytes, at both the protein and mRNA levels while it did not affect the expression of Rab27a and MyoVa, the other two key proteins for melanosome transport. Notably, the expression of melanogenic proteins, including tyrosinase, trp1, trp2, and MITF, was not affected by 16-kauren. However, 16-kauren attenuated melanosome distribution in co-culture of Melan-a melanocytes and SP-1 keratinocytes as well as in Melan-a monolayer culture. In further confirmation of the depigmenting effects of 16-kauren on Melanoderm™, a 3D pigmented human skin model, treatment with 16-kauren for 12 days increased the brightness of the tissue as determined by lightness value and reduced the distribution of melanosomes as shown in histological examination. CONCLUSION: These results demonstrated that 16-kauren is a selective modulator of a melangenic target, Mlph expression, and can be employed as a new depigmenting strategy.