Identification of miR-145 as a key regulator of the pigmentary process.
The current treatments for hyperpigmentation are often associated with a lack of efficacy and adverse side effects. We hypothesized that microRNA (miRNA)-based treatments may offer an attractive alternative by specifically targeting key genes in melanogenesis. The aim of this study was to identify miRNAs interfering with the pigmentary process and to assess their functional role. miRNA profiling was performed on mouse melanocytes after three consecutive treatments involving forskolin and solar-simulated UV (ssUV) irradiation. Sixteen miRNAs were identified as differentially expressed in treated melan-a cells versus untreated cells. Remarkably, a 15-fold downregulation of miR-145 was detected. Overexpression or downregulation of miR-145 in melan-a cells revealed reduced or increased expression of Sox9, Mitf, Tyr, Trp1, Myo5a, Rab27a, and Fscn1, respectively. Moreover, a luciferase reporter assay demonstrated direct targeting of Myo5a by miR-145 in mouse and human melanocytes. Immunofluorescence tagging of melanosomes in miR-145-transfected human melanocytes displayed perinuclear accumulation of melanosomes with additional hypopigmentation of harvested cell pellets. In conclusion, this study has established an miRNA signature associated with forskolin and ssUV treatment. The significant down- or upregulation of major pigmentation genes, after modulating miR-145 expression, suggests a key role for miR-145 in regulating melanogenesis.
Department of Dermatology, Ghent University Hospital, Ghent, Belgium.
Peter
P
Dynoodt
Pieter
P
Mestdagh
Gert
G
Van Peer
Jo
J
Vandesompele
Karen
K
Goossens
Luc J
LJ
Peelman
Barbara
B
Geusens
Reinhart M
RM
Speeckaert
Jo L W
JL
Lambert
Mireille J L
MJ
Van Gele
D000818:Animals; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D058965:MART-1 Antigen / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D020460:Melanosomes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D051739:Microphthalmia-Associated Transcription Factor / Q000096:biosynthesis; D014442:Monophenol Monooxygenase / Q000096:biosynthesis; D018995:Myosin Heavy Chains / Q000096:biosynthesis; D024701:Myosin Type V / Q000096:biosynthesis; D010858:Pigmentation / Q000235:genetics / Q000502:physiology*; D055758:SOX9 Transcription Factor / Q000096:biosynthesis; D014162:Transfection; D014357:Trypsin / Q000096:biosynthesis; D014466:Ultraviolet Rays; D020691:rab GTP-Binding Proteins / Q000096:biosynthesis; D000075745:rab27 GTP-Binding Proteins
D058965:MART-1 Antigen; C543499:MIRN145a microRNA, mouse; D035683:MicroRNAs; D051739:Microphthalmia-Associated Transcription Factor; C497235:Mitf protein, mouse; C513082:Myo5a protein, mouse; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D000075745:rab27 GTP-Binding Proteins; D005576:Colforsin; D014442:Monophenol Monooxygenase; C549765:Prss1 protein, mouse; D014357:Trypsin; D024701:Myosin Type V; C512962:Rab27a protein, mouse; D018995:Myosin Heavy Chains; D020691:rab GTP-Binding Proteins