• Main Authors: Inês Ferreira dos Santos Videira, Daniel Filipe Lima Moura, Sofia Magina
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Dermatologia 2013-02-01
• Series: Anais Brasileiros de Dermatologia
• Subjects: Melanócitos; Pigmentação da pele; Queratinócitos; Radiação solar; Transtornos da pigmentação; Keratinocytes; Melanocytes; Pigmentation disorders; Skin pigmentation; Solar radiation
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0365-05962013000100076

Skin pigmentation is an important human phenotypic trait whose regulation, in spite of recent advances, has not yet been fully understood. The pigment melanin is produced in melanosomes by melanocytes in a complex process called melanogenesis. The melanocyte interacts with endocrine, immune, inflammatory and central nervous systems, and its activity is also regulated by extrinsic factors such as ultraviolet radiation and drugs. We have carried out a review of the current understanding of intrinsic and extrinsic factors regulating skin pigmentation, the melanogenesis stages and related gene defects. We focused on melanocyte-keratinocyte interaction, activation of melanocortin type 1 receptor (MC1-R) by peptides (melanocyte-stimulating hormone and adrenocorticotropic hormone) resulting from proopiomelanocortin (POMC) cleavage, and mechanisms of ultraviolet-induced skin pigmentation. The identification and comprehension of the melanogenesis mechanism facilitate the understanding of the pathogenesis of pigmentation disorders and the development of potential therapeutic options.<br>A pigmenta&#231;&#227;o da pele &#233; um importante tra&#231;o fenot&#237;pico do ser humano mas apesar dos recentes avan&#231;os a sua regula&#231;&#227;o n&#227;o est&#225; ainda totalmente esclarecida. O pigmento melanina &#233; produzido nos melanossomas pelos melan&#243;citos, num processo complexo designado por melanog&#233;nese. O melan&#243;cito interatua com os sistemas end&#243;crino, imunit&#225;rio, inflamat&#243;rio e nervoso central e a sua atividade &#233; tamb&#233;m regulada por fatores extr&#237;nsecos como a radia&#231;&#227;o ultravioleta e f&#225;rmacos. Fizemos uma revis&#227;o do conhecimento atual sobre os fatores intr&#237;nsecos e extr&#237;nsecos reguladores da pigmenta&#231;&#227;o cut&#226;nea, etapas da melanog&#233;nese e defeitos gen&#233;ticos relacionados. Fizemos enfoque na intera&#231;&#227;o melan&#243;cito-keratin&#243;cito, na ativa&#231;&#227;o do receptor da melanocortina tipo 1 (MC1-R) pelos p&#233;ptidos (hormona estimuladora do melan&#243;cito e hormona adrenocorticotr&#243;fica) resultantes da clivagem da proopiomelanocortina (POMC) e mecanismos da pigmenta&#231;&#227;o induzida pela radia&#231;&#227;o ultravioleta. A identifica&#231;&#227;o e compreens&#227;o dos mecanismos reguladores da pigmenta&#231;&#227;o cut&#226;nea facilitam o conhecimento dos mecanismos patog&#233;nicos dos dist&#250;rbios da pigmenta&#231;&#227;o e o desenvolvimento de potenciais op&#231;&#245;es terap&#234;uticas.