Journal: Pflugers Archiv
Article Title: SECS, drugs, and Rac1&Rho: regulation of EnNaC in vascular endothelial cells
doi: 10.1007/s00424-025-03093-5
Figure Lengend Snippet: Rapid EnNaC membrane insertion and altered nanomechanics after aldosterone stimulation. A Time-series of 10 nM aldosterone application on EA.hy926 cells and quantification of EnNaC membrane abundance via Q-dot-based fluorescence staining. Already after 2 min of 10 nM aldosterone stimulation, a significant increase of the number of EnNaC within the membrane could be observed, reaching the highest channel density after 6 min ( N = 3, n = 60; **** p < 0.0001 vs. control (0 min), Kruskal–Wallis test). B EnNaC density was analysed in a concentration series with 7 min stimulation in EA.hy926 cells, already showing an increase of EnNaC membrane abundance after stimulation with 0.1 nM aldosterone ( N = 3, n = 60; **** p < 0.0001 vs. control (0 nM), Kruskal–Wallis test). C Short-term application (7 min) of 1 nM aldosterone was combined with the MR-antagonist spironolactone (100 nM), and EnNaC membrane abundance was analysed using EA.hy926 cells. Aldosterone increased the number of EnNaC within the membrane, whereas spironolactone did not additionally affect the EnNaC number ( N = 3, n = 60; **** p < 0.0001 vs. control). D Functional EnNaC inhibition acutely changed cortical stiffness of EA.hy926 cells (stimulation < 2 min) after treatment with amiloride as well as benzamil measured by AFM-based nanoindentation ( N = 3, n = 59–71; ** p < 0.01, **** p < 0.0001 vs. control, Kruskal–Wallis test). E Stabilization of filamentous F-actin by Jasplakinolide abolished the Amiloride-induced softening of the actin cortex (EA.hy926, N = 5, n = 25–129, * p < 0.05, ** p < 0.01, **** p < 0.0001 vs. control, ANOVA). F F-actin stabilization by Jasplakinolide (JAS) directly affected the number of EnNaC channels in the membrane (HUVECs, N = 4, n = 80, *** p < 0,001, Mann–Whitney test). G Alterations of F- to G-actin ratio in response to EnNaC inhibition were analysed in a western blot-based approach in EA.hy926. Amiloride and benzamil both led to a reduction of F-actin to G-actin proportion ( N = 3, ns. vs. control). H Actin polymerization was analysed by phalloidin-TRITC fluorescence intensity analysis. Amiloride, benzamil, and the positive control, cytochalasin D (CytD), led to a significant reduction of phalloidin fluorescence (EA.hy926, N = 3, n = 60; * p < 0.05, **** p < 0.0001 vs. control, Kruskal–Wallis test)
Article Snippet: In vitro cell culture stimulation: After reaching confluence, cells were treated with the following substances, depending on the experiments: 0.1–10 nM aldosterone, 100 nM spironolactone, 1 μM amiloride, 0.1 μM benzamil, 50 nM cytochalasin D (CytD), 10 μM CK548 (all from Sigma Aldrich, St. Louis, MO, USA), 10 μM LY294002, 0.5 μM jasplakinolide (Thermo Fisher Scientific), 10 μM chelerythrin chloride, 5 μg/mL brefeldin A (both Biomol, Hamburg, Germany), 50 μM NSC23766 (Tocris, Bristol, UK), 1 μg/mL CT04 (Cytoskeleton, Denver, CO, USA), and 30 μM Pitstop-2 (Abcam, Cambridge, UK).
Techniques: Membrane, Fluorescence, Staining, Control, Concentration Assay, Functional Assay, Inhibition, MANN-WHITNEY, Western Blot, Positive Control