title: The epidermal stem cell factor is over-expressed in lentigo senilis: implication for the mechanism of hyperpigmentation.
abstract: We previously reported that accentuated expression of the endothelin-1 (ET-1)/endothelin B receptor (ET(B)R) cascade is involved in the mechanism of hyperpigmentation in lentigo senilis (LS) lesions. The paracrine mechanism underlying ultraviolet B (UVB)-induced hyperpigmentation in the skin may involve the stimulation of the ET-1/ET(B)R cascade as well as the stem cell factor (SCF)/SCF receptor cascade. Therefore, we used RT-PCR and immunohistochemistry to determine whether accentuated expression of the SCF/SCF receptor cascade is also associated with the mechanism of hyperpigmentation in epidermal LS lesions. RT-PCR analysis demonstrated the increased expression of mRNA transcripts for SCF (n=7), but not for SCF receptor (n=6) or growth-related oncogene alpha (GROalpha) (n=4) in LS lesions. Immunohistochemistry revealed markedly stronger staining for SCF but not for GROalpha or basic fibroblast growth factor (bFGF) in the lesional epidermis compared with the perilesional epidermis. This increased staining for SCF was corroborated by western blotting analysis for SCF expression in the lesional epidermis. These findings suggest that in addition to the stimulated expression of the ET-1/ET(B)R cascade, the accentuated expression of SCF in lesional skin plays an important role in the mechanism involved in the epidermal hyperpigmentation of LS.
authors.affiliation: Department of Dermatology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Hideko
authors.initials: H
authors.lastname: Hattori
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawashima
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ichikawa
authors.forename: Genji
authors.initials: G
authors.lastname: Imokawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D054360:Chemokine CXCL1; D018925:Chemokines / Q000235:genetics / Q000378:metabolism; D002630:Chemotactic Factors / Q000235:genetics / Q000378:metabolism; D004817:Epidermis / Q000503:physiopathology*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D007911:Lentigo / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012880:Skin Pigmentation / Q000502:physiology*; D019089:Stem Cell Factor / Q000235:genetics* / Q000378:metabolism
chemical_list: C475896:CXCL1 protein, Bos taurus; D054360:Chemokine CXCL1; D018925:Chemokines; D002630:Chemotactic Factors; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit