Fig. 3: Cytokine-induced glucose-regulated protein 78 (GRP78) membrane translocation is Golgi and secretory pathway dependent. | Cell Death & Disease

Fig. 3: Cytokine-induced glucose-regulated protein 78 (GRP78) membrane translocation is Golgi and secretory pathway dependent.

From: Cytokine-induced translocation of GRP78 to the plasma membrane triggers a pro-apoptotic feedback loop in pancreatic beta cells

Fig. 3

a Microscopic imaging of Golgi apparatus disruption with brefeldin A (BFA; 0.2 μg/ml, 16 h) and golgicide A (GCA; 10 μM, 16 h) in MIN6 cells, evaluated by immunostaining with the Golgi marker 130 (GM130; red) and Hoechst (Hoechst 33342; blue). One representative experiment out of three independent experiments is shown. Scale bars, 10 μm (without zoom) and 5 μm (with zoom). be Flow cytometry of MIN6 cells upon co-incubation of cytokines (Cyt) with BFA or GCA. Percentage of sGRP78-positive cells in the living (b) and early apoptotic (c) subpopulation. MFI for surface GRP78 in the living (d) and early apoptotic (e) subpopulation. Data are presented as mean ± SEM (n = 7) and statistically analyzed by a one-way analysis of variance followed by Sidak posthoc test for multiple group comparisons. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. f, g Transmission electron microscopic (TEM) images of Immunogold-labeled GRP78 in control (f) and cytokine-exposed (16 h) (g) MIN6 cells. Per condition, one representative image out of three independent experiments is shown. Black arrows point to the GRP78-bound gold particle (10 nm) localized in the secretory granules’ limiting membranes, whereas white arrows indicate GRP78-bound gold particles localized within the secretory vesicles. Images were captured at ×10,000 zoom. Scale bars are 250 nm in the upper panel and 100 nm in the lower panel