Mouse islet cell lysis mediated by interleukin-1-induced Fas.
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.
Yamada
K
K
Department of Medicine, Kurume University School of Medicine, Japan.
Takane-Gyotoku
N
N
Yuan
X
X
Ichikawa
F
F
Inada
C
C
Nonaka
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology; D002478:Cells, Cultured; D002840:Chromates / Q000032:analysis / Q000378:metabolism; D002860:Chromium Radioisotopes; D003513:Cycloheximide / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D007375:Interleukin-1 / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016133:Polymerase Chain Reaction; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017670:Sodium Compounds / Q000032:analysis / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019014:fas Receptor / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D002840:Chromates; D002860:Chromium Radioisotopes; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D017670:Sodium Compounds; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D019323:omega-N-Methylarginine; C028982:sodium chromate(VI); D003513:Cycloheximide