title: Decreased expression of semaphorin-3A, a neurite-collapsing factor, is associated with itch in psoriatic skin.
abstract: Pruritus is a common symptom of psoriasis, which affects quality of life. This symptom accompanies the hyper-innervation of sensory C-fibres in psoriatic lesions. Two extracellular molecules, nerve growth factor (NGF) and semaphorin-3A, regulate C-fibre extension. In this study, the expression levels of these 2 molecules in biopsy specimens from psoriatic and healthy skin were quantified by immunohistochemistry and quantitative reverse-transcription PCR. Semaphorin-3A expression was lower in the psoriatic samples compared with the healthy samples, whereas NGF was higher. C-fibre innervation in the epidermis was also increased in psoriatic skin. Semaphorin-3A mRNA expression was negatively correlated with itch intensity and severity of psoriasis. We propose that decreased semaphorin-3A and increased NGF expression levels may trigger the outgrowth of C-fibres, leading to pruritus.
authors.affiliation: Department of Environmental Immuno-Dermatology, Yokohama City University Graduate School of Medicine, Japan.
authors.forename: Kenzen
authors.initials: K
authors.lastname: Kou
authors.forename: Fumio
authors.initials: F
authors.lastname: Nakamura
authors.forename: Michiko
authors.initials: M
authors.lastname: Aihara
authors.forename: Huichin
authors.initials: H
authors.lastname: Chen
authors.forename: Katsuya
authors.initials: K
authors.lastname: Seto
authors.forename: Junko
authors.initials: J
authors.lastname: Komori-Yamaguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kambara
authors.forename: Yoji
authors.initials: Y
authors.lastname: Nagashima
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Goshima
authors.forename: Zenro
authors.initials: Z
authors.lastname: Ikezawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D036421:Nerve Fibers, Unmyelinated / Q000737:chemistry; D020932:Nerve Growth Factor / Q000032:analysis; D039942:Neuropilin-1 / Q000032:analysis; D011537:Pruritus / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011565:Psoriasis / Q000150:complications* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D040121:Semaphorin-3A / Q000032:analysis* / Q000235:genetics; D012720:Severity of Illness Index; D012867:Skin / Q000737:chemistry* / Q000294:innervation / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers; C502240:NGF protein, human; D012333:RNA, Messenger; C108639:SEMA3A protein, human; D040121:Semaphorin-3A; D039942:Neuropilin-1; D020932:Nerve Growth Factor