Reduced expression of nicotinic alpha subunits 3, 7, 9 and 10 in lesional and nonlesional atopic dermatitis skin but enhanced expression of alpha subunits 3 and 5 in mast cells.
BACKGROUND
The skin cholinergic signalling system is modulated in atopic dermatitis (AD).


OBJECTIVE
To investigate of the role of nicotinic acetylcholine receptors (nAChRs) in the pathogenesis of AD.


METHODS
We investigated the expression and localization of nAChR alpha subunits in AD by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry of biopsies from lesional and nonlesional areas of AD skin and of skin biopsies from healthy control persons.


RESULTS
Our data demonstrate the presence of mRNA and protein of the nAChR alpha subunits 3, 5, 7, 9 and 10 in keratinocytes and mast cells in healthy and AD skin. Expression of the alpha subunits 3, 7, 9 and 10 was generally reduced in the skin of patients with AD whereas mast cells in AD but not in healthy skin showed alpha3 and alpha5 subunit immunoreactivity. Differences in the subunit mRNA levels between lesional and nonlesional skin were obtained for the alpha subunits 3, 9 and 10 with higher levels of alpha3 but lower levels of alpha10 subunit mRNA in lesional areas. No differences in the expression of the alpha subunits was found between the groups of extrinsic, intrinsic or mixed AD types, between genders and between smokers and nonsmokers.


CONCLUSIONS
This supports the idea that the cholinergic system is dysregulated independently from inflammation in AD and that inflammation further modulates individual nAChR subunits.
Kindt
F
F
Institute for Anatomy and Cell Biology, and Department of Psychosomatic Medicine, Justus-Liebig-University Giessen, Germany.
Wiegand
S
S
Niemeier
V
V
Kupfer
J
J
Löser
C
C
Nilles
M
M
Kurzen
H
H
Kummer
W
W
Gieler
U
U
Haberberger
R V
RV
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D016022:Case-Control Studies; D003876:Dermatitis, Atopic / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000276:immunology / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D011978:Receptors, Nicotinic / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
D012333:RNA, Messenger; D011978:Receptors, Nicotinic