Suppressor of cytokine signalling-3 inhibits Tumor necrosis factor-alpha induced apoptosis and signalling in beta cells.
Tumor necrosis factor-alpha (TNFalpha) is a pro-inflammatory cytokine involved in the pathogenesis of several diseases including type 1 diabetes mellitus (T1DM). TNFalpha in combination with interleukin-1-beta (IL-1beta) and/or interferon-gamma (IFNgamma) induces specific destruction of the pancreatic insulin-producing beta cells. Suppressor of cytokine signalling-3 (SOCS-3) proteins regulate signalling induced by a number of cytokines including growth hormone, IFNgamma and IL-1beta which signals via very distinctive pathways. The objective of this study was to investigate the effect of SOCS-3 on TNFalpha-induced signalling in beta cells. We found that apoptosis induced by TNFalpha alone or in combination with IL-1beta was suppressed by expression of SOCS-3 in the beta cell line INSr3#2. SOCS-3 inhibited TNFalpha-induced phosphorylation of the mitogen activated protein kinases ERK1/2, p38 and JNK in INSr3#2 cells and in primary rat islets. Furthermore, SOCS-3 repressed TNFalpha-induced degradation of IkappaB, NFkappaB DNA binding and transcription of the NFkappaB-dependent MnSOD promoter. Finally, expression of Socs-3 mRNA was induced by TNFalpha in rat islets in a transient manner with maximum expression after 1-2h. The ability of SOCS-3 to regulate signalling induced by the three major pro-inflammatory cytokines involved in the pathogenesis of T1DM makes SOCS-3 an interesting therapeutic candidate for protection of the beta cell mass.
Bruun
Christine
C
Hagedorn Research Institute, Niels Steensens Vej 6, NSK2.02, DK-2820 Gentofte, Denmark.
Heding
Peter E
PE
Rønn
Sif G
SG
Frobøse
Helle
H
Rhodes
Christopher J
CJ
Mandrup-Poulsen
Thomas
T
Billestrup
Nils
N
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D004247:DNA / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000201:enzymology*; D053583:Interleukin-1beta / Q000494:pharmacology; D051379:Mice; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000235:genetics; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D020672:I-kappa B Proteins; D053583:Interleukin-1beta; D016328:NF-kappa B; C106644:SOCS3 protein, human; C491410:Socs3 protein, rat; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D014409:Tumor Necrosis Factor-alpha; D004247:DNA; D013482:Superoxide Dismutase; D020928:Mitogen-Activated Protein Kinases