title: Interleukin 1 (IL-1) and IL-1-receptor antagonist (IL-1-RA) in middle ear cholesteatoma: an analysis of protein production and biological activity.
abstract: Cytokine networks are now presumed to play an essential role in the pathogenesis of middle ear cholesteatoma. Of the factors identified in cholesteatoma, interleukin-I (IL-1)-alpha appears to be especially important because of its stimulation of keratinocyte proliferation as well induction of bone resorption. To further characterize the possible role of IL-1 in the pathogenesis of cholesteatoma, we quantified the levels of IL-1 and IL-1-receptor antagonist (IL-1-RA) present using the bicinchonic acid protein assay and enzyme-linked immunosorbent assay (ELISA) on tissue extracts from 20 cholesteatoma specimens. The presence of biologically active IL-1 was also analyzed, using the cell line LBRM-33 and an ELISA for the detection of interleukin-2 (IL-2). Human skin obtained from the external ear canal was used as control. The amounts of IL-1-alpha in cholesteatoma (34.9 +/- 19.5) were higher than in human skin (6.7 +/- 2.8). The observed differences were statistically significant by Student's t-test (P < 0.01). Skin samples showed elevated concentrations of IL-1-RA (248.3 +/- 30.2) in comparison to that in the cholesteatoma (80.8 +/- 13.5). This was also statistically significant (P < 0.01). Whereas IL-1 activity was not detected in skin samples, all cholesteatoma specimens studied showed a stimulation effect on the production of IL-2 when incubated with the cell line LBRM-33. The results point to an over-expression of IL-1 concurrent with a decreased secretion of IL-1-RA in middle ear cholesteatoma. Furthermore IL-1-RA production is deficient relative to total IL-1 production, resulting in the presence of active IL-1.
authors: Department of Otolaryngology, Head-Neck Surgery, Ludwig Maximilians University, Klinikum Grosshadern, Munich, Germany.
authors: J
authors: J
authors: Bujía
authors: C
authors: C
authors: Kim
authors: P
authors: P
authors: Ostos
authors: H
authors: H
authors: Sudhoff
authors: E
authors: E
authors: Kastenbauer
authors: L
authors: L
authors: Hültner
mesh_terms: D001681:Biological Assay; D002460:Cell Line; D018424:Cholesteatoma, Middle Ear / Q000276:immunology* / Q000473:pathology; D046508:Culture Techniques; D004432:Ear, Middle / Q000276:immunology / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000502:physiology; D011804:Quinolines; D012795:Sialoglycoproteins / Q000502:physiology*
chemical_list: C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D007376:Interleukin-2; D011804:Quinolines; D012795:Sialoglycoproteins; C047117:bicinchoninic acid