Deletion of the T1D risk gene Ormdl3 in β-cells does not impact disease progression

Figures

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  Fig. 1. Deletion of Ormdl3 in β-cells of NOD mice does not alter diabetes progression. (A) Schematic representation of Ormdl3 deletion through tamoxifen administration to lactating dam. (B) Fold change gene expression of Ormdl isoforms in islets from 6-week-old control (Ormdl3fl/fl (n = 2) and Cre-only (n = 1)) and Ormdl3β−/− mice (n = 3). Unpaired, two-tailed Welch's t-test, p = 0.1267 (Ormdl1), 0.1713 (Ormdl2), and 0.0003 (Ormdl3). (C) Body weight and (D) 6-h fasting blood glucose levels of Cre-only (n = 16) and Ormdl3fl/fl (n = 17), and Ormdl3β−/− (n = 20) mice. Brown line marks 250 mg/dL. (E) Diabetes progression of Cre-only (n = 16) and Ormdl3fl/fl (n = 17), and Ormdl3β−/− (n = 20) mice up to 50 weeks of age. Kaplan-Meier estimate, p = 0.4479 (Ormdl3β−/− vs. Ormdl3fl/fl), 0.6207 (Ormdl3β−/− vs. Cre-only), and 0.8542 (Ormdl3fl/fl vs. Cre-only). (F) Serum insulin, (G) proinsulin levels, and (H) proinsulin: insulin ratio in 12-week-old control (Cre-only (n = 5)) and Ormdl3β−/− (n = 6) mice. Each data point represents a mouse. Unpaired, two-tailed Welch's t-test, p = 0.1222 (insulin), 0.5567 (proinsulin), and 0.6750 (proinsulin: insulin ratio). w, weeks; ns, not significant. All data…

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  Fig. 2. Ormdl3β−/− mice do not exhibit altered islet morphology, β-cell proliferation or death. (A) Representative images of pancreatic sections from 12-week-old control and Ormdl3β−/− mice co-stained with anti-insulin (green) and anti-glucagon (red) antibodies. (B) Representative images of pancreatic sections from 12-week-old control and Ormdl3β−/− mice co-stained with anti-insulin (green) and anti-somatostatin (red) antibodies. (C) Quantification of endocrine islet cell area as a percentage of total islet area in 12-week-old control (Ormdl3fl/fl (n = 3) and Cre-only(n = 5)) and Ormdl3β−/− mice (n = 7). Each data point represents a mouse. Unpaired, two-tailed Welch's t-test, p = 0.2813 (α-cell), 0.3266 (β-cell), and 0.6836 (δ-cell). (D) Representative images of pancreatic sections from 12-week-old control and Ormdl3β−/− mice co-stained with anti-insulin (green) and anti-Ki67 (red) antibodies. (E) Quantification of Ki67+ β-cells in pancreatic sections from control (Ormdl3fl/fl (n = 3) and Cre-only(n = 5)) and Ormdl3β−/− mice (n = 7). Each data point represents a mouse. Unpaired, two-tailed Welch's t-test, p = 0.4904. (F) Representative images of pancreatic sections from 12-week-old…

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  Fig. 3. Ormdl3β−/− mice do not exhibit altered insulitis or relative representation of immune cells. (A) Representative images of H&E-stained pancreatic sections from 12-week-old control and Ormdl3β−/− mice. (B) Quantifications of immune infiltrates in the islets of 12-week-old control (Ormdl3fl/fl (n = 3) and Cre-only(n = 5)) and Ormdl3β−/− mice (n = 7). Each data point represents a mouse. Unpaired, two-tailed Welch's t-test, p = 0.2966 (intact), 0.8607 (peri-insulitis), 0.2454 (non-aggresive insulitis), and 0.5184 (aggresive insulitis). (C) Representative images of pancreatic sections from 12-week-old control and Ormdl3β−/− mice co-stained with anti-insulin (green) and anti-CD3, anti-CD4, anti-CD8, and anti-B220 (red) antibodies. Immunophenotyping of (D) pancreas, (E) spleen, and (F) PLN of 20-week-old control (Ormdl3fl/fl (n = 3) and Cre-only (n = 2)) and Ormdl3β−/− (n = 5) mice. Each data point represents a mouse. Unpaired, two-tailed Welch's t-test. Scale bars: 20 μm ns, not significant; DAPI, 4′,6-diamidino-2-phenylindole; PLN, pancreatic lymph node. All data are represented as means ± SEM.