Bcl-2 and Bcl-xL Suppress Glucose Signaling in Pancreatic β-Cells

(Downloading may take up to 30 seconds. If the slide opens in your browser, select File -> Save As to save it.)

Click on image to view larger version.

FIG. 5.
FIG. 5.

Loss of Bcl-2 enhances β-cell glucose responses. A: Quantitative PCR (qPCR) quantification of Bcl-2 and Bcl-xL mRNA levels in islets from Bcl-2+/− and Bcl-2−/− mice relative to Bcl-2+/+ littermates (n = 3 mice of each genotype). All data are mean ± SEM. B: Average cytosolic Ca2+ levels of dispersed islet cells from littermate Bcl-2+/+, Bcl-2+/−, and Bcl-2−/− mice. Shaded hanging bars represent SEM. C: Incremental area under the curve of Ca2+ responses (n = 98 Bcl-2+/+ cells, n = 144 Bcl-2+/− cells, and n = 147 Bcl-2−/− cells from three mice of each genotype; *P < 0.001 Bcl-2−/− vs. Bcl-2+/+, **P < 0.01 Bcl-2−/− vs. Bcl-2+/−, and #P < 0.05 Bcl-2+/− vs. Bcl+/+). D: Integrated cytosolic Ca2+ responses of Bcl-2−/− and Bcl-2+/+ β-cells depolarized with 30 mmol/L KCl (n = 87 Bcl-2+/+ cells and 130 Bcl-2−/− cells from three mice of each genotype). n.s., not significant. E and F: Integrated Ca2+ and NAD(P)H autofluorescence increases of intact islets, normalized to Bcl-2+/+ control (panel E: n = 16 Bcl-2+/+ islets; n = 20 Bcl-2+/− islets; n = 21 Bcl-2−/− islets; and panel F: n = 16 Bcl-2+/+ islets; n = 17 Bcl-2−/− islets; three mice of each genotype; *P < 0.05, **P < 0.01 vs. Bcl-2+/+). G: Insulin secretion profiles of perifused islets from 5–7-week-old Bcl-2+/+ and Bcl-2−/− mice. H: Quantified area under the curve of insulin secretion profiles in panel G (n = 5; *P < 0.05 vs. Bcl-2+/+). a.u., arbitrary units. (A high-quality color representation of this figure is available in the online issue.)

This Article

  1. Diabetes vol. 62 no. 1 170-182