Mouse islet cell lysis mediated by interleukin-1-induced Fas

• Published in: Diabetologia Vol. 39; no. 11; p. 1306
• Main Authors: Yamada, K, Takane-Gyotoku, N, Yuan, X, Ichikawa, F, Inada, C, Nonaka, K
• Format: Journal Article
• Language: English
• Published: Germany 01.11.1996
• Subjects: Animals; Antibodies, Monoclonal - immunology; Apoptosis - drug effects; Apoptosis - immunology; Autoimmune Diseases - etiology; Autoimmune Diseases - immunology; Cells, Cultured; Chromates - analysis; Chromates - metabolism; Chromium Radioisotopes; Cycloheximide - pharmacology; Cytotoxicity, Immunologic - drug effects; Cytotoxicity, Immunologic - immunology; Diabetes Mellitus, Type 1 - etiology; Diabetes Mellitus, Type 1 - immunology; Dose-Response Relationship, Drug; Enzyme Inhibitors - pharmacology; fas Receptor - biosynthesis; fas Receptor - drug effects; fas Receptor - genetics; fas Receptor - immunology; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Gene Expression Regulation - immunology; Interleukin-1 - pharmacology; Islets of Langerhans - cytology; Islets of Langerhans - drug effects; Islets of Langerhans - immunology; Islets of Langerhans - metabolism; Male; Mice; Mice, Inbred BALB C; omega-N-Methylarginine - pharmacology; Polymerase Chain Reaction; Protein Synthesis Inhibitors - pharmacology; Rats; RNA, Messenger - analysis; RNA, Messenger - genetics; Sodium Compounds - analysis; Sodium Compounds - metabolism; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s001250050574

This study was conducted to investigate the possible involvement of Fas in beta-cell death in insulitis of Type 1 (insulin-dependent) diabetes mellitus. Although primary cultured Balb/c mouse islet cells did not express Fas mRNA, 4-12 hours of treatment with 10(2)-10(3) U/l of mouse interleukin-1 alpha (IL-1 alpha) induced the expression of Fas mRNA. Surface Fas expression was detected by immunofluorescence flow cytometry using a non-cytolytic anti-Fas monoclonal antibody after 6 or 12 h of incubation with 10(3) U/l of IL-1 alpha. Primary islet cells were resistant to an agonistic anti-Fas monoclonal antibody. However, 12 h pretreatment with IL-1 alpha sensitized islet cells to its cytolytic effect. Significant cell death was observed 24 h after the addition of anti-Fas, and progressively increased until 72 h, when specific 51Cr release was 72 +/- 6%. Agarose gel electrophoresis of DNA extracted from cells exposed to IL-1 alpha and agonistic anti-Fas showed internucleosomal DNA fragmentation, a hallmark of apoptotic cell death. Since the Fas antibody showed no cross-reactive activity of tumour necrosis factor (TNF), the cytotoxic effect was not mediated by TNF receptors. A protein synthesis inhibitor cycloheximide augmented Fas-mediated islet cell death. The Fas-mediated killing of islet cells was not L-arginine-dependent, or blocked by N(G)-monomethyl-L-arginine. beta-TC1 cells also expressed Fas mRNA when exposed to IL-1 alpha or IL-1 alpha plus interferon-gamma. These observations suggest that Fas-mediated apoptosis may be a mechanism of islet cell death in autoimmune insulitis.