Inducible and constitutive beta-defensins are differentially expressed in Crohn's disease and ulcerative colitis.
Antimicrobial peptides such as defensins provide nonspecific mucosal defense against a multitude of microorganisms. Recently, it has been shown that luminal bacteria may invade the mucosa in inflammatory bowel diseases, suggesting a defect in innate mucosal immunity. The aim of this study was to investigate the expression of human beta-defensins (HBD) in controls, Crohn's disease (CD), ulcerative colitis (UC), and unspecific inflammation. Up to 4 biopsies were taken from 103 patients (33 controls, 24 with Crohn's disease, 36 with ulcerative colitis, 10 with unspecific colitis). Mucosal mRNA was measured using real-time fluorescence temperature cycler reverse-transcription polymerase chain reaction with primers for HBD-1, HBD-2, HBD-3, tumor necrosis factor alpha, and interleukin 8. Mucosal HBD-1 expression was marginally decreased in both CD and UC. HBD-2 was increased exclusively in UC but not in CD. The expression of the novel defensin HBD-3 was strongly correlated with HBD-2 and also raised predominantly in UC. The expression of both inducible beta-defensins was enhanced in the state of inflammation. Expression of HBD-2 showed a weak correlation with interleukin 8 only in inflamed CD biopsies but not with tumor necrosis factor alpha. The missing induction of both inducible beta-defensins in CD as compared with UC may cause a defect in barrier function that predisposes to bacterial invasion.
Wehkamp
Jan
J
Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany.
Harder
Juergen
J
Weichenthal
Michael
M
Mueller
Oliver
O
Herrlinger
Klaus R
KR
Fellermann
Klaus
K
Schroeder
Jens M
JM
Stange
Eduard F
EF
D000293:Adolescent; D000328:Adult; D000368:Aged; D001419:Bacteria / Q000472:pathogenicity; D001706:Biopsy; D002648:Child; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000382:microbiology / Q000503:physiopathology*; D003424:Crohn Disease / Q000276:immunology* / Q000382:microbiology / Q000503:physiopathology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023083:beta-Defensins / Q000096:biosynthesis*
D012333:RNA, Messenger; D023083:beta-Defensins