Journal: iScience

Article Title: Tet2 modulates ER stress responses related to β-cell death and autoimmunity in diabetes

doi: 10.1016/j.isci.2026.114818

Figure Lengend Snippet: Inhibiting TET activity protects human islets from ER stress, cell death and inflammatory responses Gene expression in human islets (n = three to four experiments, each with 4,000–8,000 islet equivalency (IEQ) from each nondiabetic donor after 48 h incubation with brefeldin A (BFA) (A) or thapsigargin (TG) (B) in the presence or absence of TET inhibitor Bobcat339 (Bobcat). The expression of all 12 tested genes, associated with ER stress and cell death were significantly greater in BFA vs. DMSO (∗∗∗∗ p < 0.0001), but significantly reduced in the presence of BFA+Bobcat (ANOVA with Dunnett’s multiple comparison test, ∗∗∗∗ p < 0.0001, ∗ p < 0.05). The expression of 11 of the 12 tested genes were significantly greater in TG vs. DMSO (∗∗∗∗ p < 0.0001), but significantly reduced in the presence of TG + Bobcat (ANOVA with Dunnett’s multiple comparison test,∗∗∗∗ p < 0.0001, ∗∗ p < 0.01). (C) Percent apoptotic and dead cells measured by flow cytometry in human islets cultured for 24 h with BFA with or without Bobcat339 (ANOVA with Tukey’s multiple comparison test,∗∗∗∗ p < 0.0001, ∗∗ p < 0.01). (D) The release of INS DNA with methylation marks indicating β cell origin 30 in human islets cultured for 24 h with BFA with or without Bobcat339 (∗∗∗∗ p < 0.0001 ANOVA with Sidak’s multiple comparison test). (E) Percentage of dead or Indoleamine 2,3-dioxygenase (IDO+) islet cells measured by flow cytometry after 48 h culture with TNFa, IL-1β, IFNy, and IFNa. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001 vs. cytokines+DMSO, ANOVA with Tukey’s multiple comparison test data (mean ± 95% CI). The data shown are the individual experiments and represent the mean ± 95 percent confidence intervals.

Article Snippet: DNA was purified from culture supernatants using the Quick-cfDNA Serum & Plasma Kit (Zymo Research) and then bisulfite treated using the EZ DNA Methylation Kit (Zymo Research).

Techniques: Activity Assay, Gene Expression, Incubation, Expressing, Comparison, Flow Cytometry, Cell Culture, DNA Methylation Assay