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Histamine H 4 receptor in oral lichen planus
Author(s) -
Salem A,
AlSamadi A,
Stegajev V,
Stark H,
HäyrinenImmonen R,
Ainola M,
Hietanen J,
Konttinen YT
Publication year - 2015
Publication title -
oral diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.953
H-Index - 87
eISSN - 1601-0825
pISSN - 1354-523X
DOI - 10.1111/odi.12290
Subject(s) - oral lichen planus , degranulation , histamine , cytokine , proinflammatory cytokine , tryptase , immunostaining , mast cell , microbiology and biotechnology , pathology , biology , receptor , immunology , inflammation , chemistry , endocrinology , medicine , immunohistochemistry
Objectives Oral lichen planus ( OLP ) is an autoimmune disease characterized by a band‐like T‐cell infiltrate below the apoptotic epithelial cells and degenerated basement membrane. We tested the hypothesis that the high‐affinity histamine H 4 receptors (H 4 Rs) are downregulated in OLP by high histamine concentrations and proinflammatory T‐cell cytokines. Materials and Methods Immunohistochemistry and immunofluorescence staining, image analysis and quantitative real‐time polymerase chain reaction of tissue samples and cytokine‐stimulated cultured SCC ‐25 and primary human oral keratinocytes. Results H 4 R immunoreactivity was weak in OLP and characterized by mast cell ( MC ) hyperplasia and degranulation. In contrast to controls, H 4 R immunostaining and MC counts were negatively correlated in OLP ( P = 0.003). H 4 R agonist at nanomolar levels led to a rapid internalization of H 4 Rs, whereas high histamine concentration and interferon‐ γ decreased HRH 4 ‐gene transcripts. Conclusion Healthy oral epithelial cells are equipped with H 4 R, which displays a uniform staining pattern in a MC ‐independent fashion. In contrast, in OLP , increased numbers of activated MC s associate with increasing loss of epithelial H 4 R. Cell culture experiments suggest a rapid H 4 R stimulation‐dependent receptor internalization and a slow cytokine‐driven decrease in H 4 R synthesis. H 4 R may be involved in the maintenance of healthy oral mucosa. In OLP , this maintenance might be impaired by MC degranulation and inflammatory cytokines.