title: Expression of proteasomal immunosubunit beta1i is dysregulated in inflammatory infiltrates of minor salivary glands in Sjogren's syndrome.
abstract: OBJECTIVE
  Minor salivary gland specimens were analyzed to investigate dysregulation of the proteasome system in patients with Sjögren's syndrome (SS) and patients with sicca syndrome.
  
  
  METHODS
  Labial biopsy specimens from 17 patients with SS and 11 patients with non-autoimmunesicca syndrome were analyzed by immunohistochemistry for expression of the inducible proteasomal subunits ss1i, ss2i, and ss5i. The infiltrating subsets of lymphocytes were characterized using immunofluorescence stainings against the cell-surface markers CD20 and CD27. Two-dimensional electrophoresis and immunoblotting were used for detection of the proteasomal subunits ss1 and ss1i in peripheral blood monocyte cells. Gene expression of the constitutive subunits ss1, ss2, and ss5 and the corresponding inducible subunits ss1i, ss2i, and ss5i was further investigated at the mRNA level in small lip biopsies using real-time polymerase chain reaction.
  
  
  RESULTS
  The expression of ss1i in infiltrating and peripheral immune cells was altered in patients with SS compared to patients with non-autoimmune sicca syndrome and healthy controls. No significant differences were found in ss2i and ss5i expression between the same groups in small lip biopsies. Chisholm-Mason grade and ss1i expression were found to be inversely correlated (Spearman r = -0.461, p = 0.014). The phenotype and distribution of the lymphocytic infiltrate showed no differences between patients with primary and secondary SS regardless of ss1i expression.
  
  
  CONCLUSIONS
  The proteasomal ss1i subunit is dysregulated in peripheral white blood cells and in inflammatory infiltrates of minor salivary glands in patients with SS.
authors.affiliation: Department of Rheumatology and Clinical Immunology, Institute of Pathology, and Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Free University and Humboldt University of Berlin, Berlin, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Morawietz
authors.forename: Lorena
authors.initials: L
authors.lastname: Martinez-Gamboa
authors.forename: Sonja
authors.initials: S
authors.lastname: Scheffler
authors.forename: Gert
authors.initials: G
authors.lastname: Hausdorf
authors.forename: Anja
authors.initials: A
authors.lastname: Dankof
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kuckelkorn
authors.forename: Thomas
authors.initials: T
authors.lastname: Doerner
authors.forename: Karl
authors.initials: K
authors.lastname: Egerer
authors.forename: Gerd-R
authors.initials: GR
authors.lastname: Burmester
authors.forename: Denise L
authors.initials: DL
authors.lastname: Faustman
authors.forename: Eugen
authors.initials: E
authors.lastname: Feist
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001706:Biopsy; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008046:Lip / Q000166:cytology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D021122:Protein Subunits / Q000235:genetics / Q000276:immunology*; D012470:Salivary Glands, Minor / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D012859:Sjogren's Syndrome / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D055815:Young Adult
chemical_list: D021122:Protein Subunits; C071313:LMP-2 protein; D003546:Cysteine Endopeptidases