158
J. Cosmet. Sci., 74.3, 158–172 (May/June 2023)
Hydrolyzed Conchiolin Protein Inhibits Dendrite Formation
of Melanocytes Via Wnt/β-catenin Signaling Pathway
KAI ZANG, ZIHENG XU, RUNXUAN WANG, XIYUN YE AND YONGYAN DANG
Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences,
East China Normal University, Shanghai, China (K.Z., Z.X., X.Y., Y.D.)
Accepted for publication July 12, 2023.
Synopsis
Soluble pearl extracts present the potential in inhibiting melanin synthesis in B16 melanoma cells. However,
the role of hydrolyzed conchiolin protein (HCP), the main protein ingredient in soluble pearl extracts, in
skin lightening remains unclear. In this study, we observed that HCP effectively inhibited endothelin-1
(ET-1) induced melanocyte dendrite formation in both PIG1 and MelanA cells, demonstrating its excellent
antagonistic properties against ET-1 in.melanosome transfer. HCP also exhibits the capability to reduce
ET-1-induced melanin secretion in MelanA cells. HCP also significantly suppressed the upregulation of
microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), Rab27a, and Rac1 gene expression.
Additionally, HCP treatments led to a notable reduction in the protein expression levels of p-GSK-3β,
β-catenin, as well as the nuclear translocation of β-catenin. Importantly, HCP exhibited low toxicity towards
MelanA and PIG1 cells. Our results indicate that HCP can effectively suppress melanin transfer in melanocytes
by antagonizing ET-1 and that HCP treatments can downregulate melanin synthesis or transfer-related gene
expression by inhibiting Wnt/β-catenin signaling pathway. HCP may emerge as a safe candidate for treating
skin pigmentation disorder in the future.
INTRODUCTION
Skin color mainly depends on the distribution of pigments in the epidermal layer.1 The
variations in skin color among individuals can be attributed to differences in the number,
size, composition, and distribution of melanosomes.2 Melanosome, a lysosome-like structure
in melanocytes, is responsible for the production of melanin.3 Mature melanosomes
undergo cytoskeletal transport towards the periphery of melanocytes to facilitate the
transfer of melanin content to the surrounding keratinocytes.4,5 A protein complex
consisting of Rab27A, Mlph/Slac2-a and myosin Va is thought to mediate actin-dependent
melanosome transportation in melanocytes.6 Dysfunction of Rab27A is known to cause
a hypopigmentation phenotype in human type 2 Griscelli syndrome patients, indicating
that Rab27A is essential in maintaining normal and well-organized pigmentation.7
Additionally, the activation of Rac1 is essential for the formation of melanocytic dendrites,
facilitating membrane ruffling, and lamellipodia formation.8 While several compounds
*Address all correspondence to Xiyun Ye, xyye@bio.ecnu.edu.cn and Yongyan Dang, yydang@bio.ecnu.cn
J. Cosmet. Sci., 74.3, 158–172 (May/June 2023)
Hydrolyzed Conchiolin Protein Inhibits Dendrite Formation
of Melanocytes Via Wnt/β-catenin Signaling Pathway
KAI ZANG, ZIHENG XU, RUNXUAN WANG, XIYUN YE AND YONGYAN DANG
Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences,
East China Normal University, Shanghai, China (K.Z., Z.X., X.Y., Y.D.)
Accepted for publication July 12, 2023.
Synopsis
Soluble pearl extracts present the potential in inhibiting melanin synthesis in B16 melanoma cells. However,
the role of hydrolyzed conchiolin protein (HCP), the main protein ingredient in soluble pearl extracts, in
skin lightening remains unclear. In this study, we observed that HCP effectively inhibited endothelin-1
(ET-1) induced melanocyte dendrite formation in both PIG1 and MelanA cells, demonstrating its excellent
antagonistic properties against ET-1 in.melanosome transfer. HCP also exhibits the capability to reduce
ET-1-induced melanin secretion in MelanA cells. HCP also significantly suppressed the upregulation of
microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), Rab27a, and Rac1 gene expression.
Additionally, HCP treatments led to a notable reduction in the protein expression levels of p-GSK-3β,
β-catenin, as well as the nuclear translocation of β-catenin. Importantly, HCP exhibited low toxicity towards
MelanA and PIG1 cells. Our results indicate that HCP can effectively suppress melanin transfer in melanocytes
by antagonizing ET-1 and that HCP treatments can downregulate melanin synthesis or transfer-related gene
expression by inhibiting Wnt/β-catenin signaling pathway. HCP may emerge as a safe candidate for treating
skin pigmentation disorder in the future.
INTRODUCTION
Skin color mainly depends on the distribution of pigments in the epidermal layer.1 The
variations in skin color among individuals can be attributed to differences in the number,
size, composition, and distribution of melanosomes.2 Melanosome, a lysosome-like structure
in melanocytes, is responsible for the production of melanin.3 Mature melanosomes
undergo cytoskeletal transport towards the periphery of melanocytes to facilitate the
transfer of melanin content to the surrounding keratinocytes.4,5 A protein complex
consisting of Rab27A, Mlph/Slac2-a and myosin Va is thought to mediate actin-dependent
melanosome transportation in melanocytes.6 Dysfunction of Rab27A is known to cause
a hypopigmentation phenotype in human type 2 Griscelli syndrome patients, indicating
that Rab27A is essential in maintaining normal and well-organized pigmentation.7
Additionally, the activation of Rac1 is essential for the formation of melanocytic dendrites,
facilitating membrane ruffling, and lamellipodia formation.8 While several compounds
*Address all correspondence to Xiyun Ye, xyye@bio.ecnu.edu.cn and Yongyan Dang, yydang@bio.ecnu.cn
Purchased for the exclusive use of nofirst nolast (unknown) From: SCC Media Library & Resource Center (library.scconline.org)
