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Hyperosmotic stress reduces melanin production by altering melanosome formation.

ABSTRACT: Many tissues of the human body encounter hyperosmotic stress. The effect of extracellular osmotic changes on melanin production has not yet been elucidated. In this study, we determined that hyperosmotic stress induced by organic osmolytes results in reduced melanin production in human melanoma MNT-1 cells. Under hyperosmotic stress, few pigmented mature melanosomes were detected, but there was an increase in swollen vacuoles. These vacuoles were stained with an anti-M6PR antibody that recognizes late endosomal components and with anti-TA99 and anti-HMB45 antibodies, implying that melanosome formation was affected by hyperosmotic stress. Electron microscopic analysis revealed that the M6PR-positive swollen vacuoles were multi-layered and contained melanized granules, and they produced melanin when L-DOPA was applied, indicating that these vacuoles were still capable of producing melanin, but the inner conditions were not compatible with melanin production. The vacuolation phenomenon induced by hyperosmotic conditions disappeared with treatment with the PI3K activator 740 Y-P, indicating that the PI3K pathway is affected by hyperosmotic conditions and is responsible for the proper formation and maturation of melanosomes. The microarray analysis showed alterations of the vesicle organization and transport under hyperosmotic stress. Our findings suggest that melanogenesis could be regulated by physiological conditions, such as osmotic pressure.

SUBMITTER: Bin BH

PROVIDER: S-EPMC4149489 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Hyperosmotic stress reduces melanin production by altering melanosome formation.

Bin Bum-Ho BH Bhin Jinhyuk J Yang Seung Ha SH Choi Dong-Hwa DH Park Kyuhee K Shin Dong Wook DW Lee Ai-Young AY Hwang Daehee D Cho Eun-Gyung EG Lee Tae Ryong TR

PloS one 20140829 8

Many tissues of the human body encounter hyperosmotic stress. The effect of extracellular osmotic changes on melanin production has not yet been elucidated. In this study, we determined that hyperosmotic stress induced by organic osmolytes results in reduced melanin production in human melanoma MNT-1 cells. Under hyperosmotic stress, few pigmented mature melanosomes were detected, but there was an increase in swollen vacuoles. These vacuoles were stained with an anti-M6PR antibody that recognize ...[more]

PMID: 25170965

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Dataset Information

Hyperosmotic stress reduces melanin production by altering melanosome formation.

Publications

Hyperosmotic stress reduces melanin production by altering melanosome formation.

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