Pancreatic beta cell damage caused by pro-inflammatory cytokines interleukin-1β (IL-1β), interferon-γ (IFNγ) and tumor necrosis
factor-α (TNFα) is a key event in the pathogenesis of type 1 diabetes. The suppressor of cytokine signaling-1 (SOCS-1) blocks
IFNγ-induced signaling and prevents diabetes in the non-obese diabetic mouse. Here, we investigated if SOCS-1 overexpression
in primary beta cells provides protection from cytokine-induced islet cell dysfunction and death. We demonstrate that SOCS-1
does not prevent increase in NO production and decrease in glucose-stimulated insulin secretion in the presence of IL-1β,
IFNγ, TNFα. However, it decreases the activation of caspase-3, -8 and -9, and thereby, promotes a robust protection from cytokine-induced
beta cell death. Our data suggest that SOCS-1 overexpression may not be sufficient in preventing all the biological activities
of IFNγ in beta cells. In summary, we show that interference with IFNγ signal transduction pathways by SOCS-1 inhibits cytokine-stimulated
pancreatic beta cell death.
Keywords Apoptosis - Islets of Langerhans - Pancreatic beta-cell - Cytokine - Caspase - Interferon-gamma