The regional distribution of melanosomes in the epidermis affords a localized intensive photoprotection for basal keratinocyte stem cells.
J Dermatol Sci
; 103(3): 130-134, 2021 Sep.
Article
en En
| MEDLINE
| ID: mdl-34238637
Human skin is a highly efficient self-renewing barrier that is critical to withstanding environmental insults. Undifferentiated keratinocyte stem cells reside in the basal layer of the epidermis and in hair follicles that continuously give rise to progenies ensuring epidermal turnover and renewal. Ultraviolet (UV) radiation is a proven cause of skin keratinocyte cancers, which preferentially occur at sun-exposed areas of the skin. Fortunately, melanocytes produce melanin that is packaged in specific organelles (termed melanosomes) that are then delivered to nearby keratinocytes, endowing the recipient cells with photoprotection. It has long been thought that melanosome transfer takes place stochastically from melanocytes to keratinocytes via an as-yet-unrecognized manner. However, recent studies have indicated that melanosomes are distributed regionally in the basal layer of the skin, affording localized intensive photoprotection for progenitor keratinocytes and stem cells that reside in the microenvironment of the basal epidermis. In this review, we summarize current knowledge about molecular and cellular mechanisms that are responsible for the selective transfer and exclusive degradation of melanosomes in the epidermis, emphasizing implications for skin carcinogenesis.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Células Madre
/
Rayos Ultravioleta
/
Melanosomas
/
Epidermis
Límite:
Humans
Idioma:
En
Revista:
J Dermatol Sci
Asunto de la revista:
DERMATOLOGIA
Año:
2021
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Países Bajos