TABLE 3

Effects of cytoplasmic (cyto) or mitochondrial (mito 1 and 2) catalase overexpression in insulin-producing RINm5F cells on cell viability after exposure to IL-1β alone or a cytokine mixture

Cell clonesCell viability (%)
IL-1β0.5 × cytokine mixture1 × cytokine mixture
Control61.2 ± 2.5 (13)69.4 ± 2.7 (10)52.1 ± 3.6 (12)
Cyto66.9 ± 4.7 (11)*77.8 ± 4.7 (4)*64.3 ± 4.6 (8),*
Mito 167.8 ± 4.0 (9)87.1 ± 3.1 (8)67.4 ± 3.1 (10)
Mito 281.7 ± 3.2 (11)94.0 ± 3.8 (5)81.1 ± 1.5 (6)
  • Data are means ± SE (no. experiments). Insulin-producing RINm5F cell clones overexpressing catalase in the cyto, mito 1 and mito 2, and control cells were incubated for 72 h with IL-1β (600 units/ml) alone, a 1 × cytokine mixture (60 units/ml IL-1β, 185 units/ml TNF-α, and 14 units/ml IFN-γ) or half of this mixture (0.5 × cytokine mixture). Viability of the cells was determined by the MTT assay and expressed as the percentage of untreated cells.

  • *

    * P < 0.05 vs. mito 2 clone;

  • P < 0.05;

  • P < 0.01 vs. control cells.