title: Alpha-melanocyte-stimulating hormone plays an important role in the onset of pollinosis in a pollen allergy mouse model.
abstract: BACKGROUND
  alpha-Melanocyte-stimulating hormone (alpha-MSH) is a neuropeptide that controls melanogenesis in pigmentary cells. In addition, its potent immunomodulatory activity has been recently described in cutaneous inflammatory disorders. However the mechanism of such pollen allergies remains to be elucidated. The purpose of this study was to investigate the role of alpha-MSH in a murine model of pollen allergy.
  
  
  METHODS
  Eight-week-old male BDF-1 mice were sensitized with Cry j I. After the last intranasal antigen, the number of sneezes was counted for 5 min. In addition, the serum levels of IgE and neuronal hormones were measured by ELISA. The expression of IgA, melanocortin receptor 1 (MC1R) and MC5R in the trachea were also observed by immunohistochemistry.
  
  
  RESULTS
  Both the concentration of alpha-MSH and adrenocorticotropin in plasma increase in pollen allergy model mice. Furthermore, MC5R increased in the trachea; however, MC1R did not increase in the trachea. In addition, the changes in sneezing and IgA expression in the pollen allergy model mice were suppressed by alpha-MSH antibody treatment, but they remained unchanged after MC1R antagonist (agouti) treatment.
  
  
  CONCLUSIONS
  These results indicate that sneezing due to pollen allergy is associated with an increased concentration of alpha-MSH and the expression of MC5R.
authors.affiliation: Department of Biochemistry and Molecular Pathology, Osaka City University Medical School, 1-4-3 Asahimachi, Abeno, Osaka, Japan. hiramoto@msic.med.osaka-cu.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hiramoto
authors.forename: Maki
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Kumi
authors.initials: K
authors.lastname: Orita
authors.forename: Mika
authors.initials: M
authors.lastname: Jikumaru
authors.forename: Eisuke F
authors.initials: EF
authors.lastname: Sato
authors.forename: Masayasu
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D004195:Disease Models, Animal; D006801:Humans; D008297:Male; D051379:Mice; D010940:Plant Proteins / Q000276:immunology*; D044102:Receptor, Melanocortin, Type 1 / Q000378:metabolism; D044101:Receptors, Melanocortin / Q000378:metabolism*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000503:physiopathology*; D012912:Sneezing; D014132:Trachea / Q000378:metabolism; D000521:alpha-MSH / Q000097:blood*
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C065290:Cry j I protein, Cryptomeria japonica; D010940:Plant Proteins; D044102:Receptor, Melanocortin, Type 1; D044101:Receptors, Melanocortin; C086971:melanocortin 5 receptor; D000521:alpha-MSH