NCX1 represents an ionic Na+ sensing mechanism in macrophages
Fig 4
HS exposure results in NCX-mediated inward currents.
(A) Current/voltage relationships of MΦ ± LPS ± HS. Whole-cell VC experiments were performed before and after stimulation of BMDMs. Voltage steps were applied, and differential currents (IHS, ILPS, ILPS+HS) were plotted (mean ± 95% CI; n = 10–13). (B) As in (A), but with NiCl2 pretreatment (means ± 95% CI; n = 10). (C) Current/voltage relationships of BMDMs stimulated with LPS ± HS followed by NiCl2 treatment. Whole-cell VR experiments were performed, and Ni-sensitive (i.e., NCX-sensitive) currents (INCX) were determined (means ± 95% CI; n = 9). (D) ErevNCX (means ± SD; n = 9; Mann–Whitney test; *p < 0.05). (E) Resting Vm of BMDMs (means ± SD; n = 36). For numerical raw data, please see S1 Data. BMDM, bone marrow–derived MΦ; ErevNCX, NCX reversal potential; HS, high salt; I, current; LPS, lipopolysaccharide; MΦ, monocyte/macrophage-like cell; NCX, Na+/Ca2+ exchanger; VC, voltage clamp; Vm, membrane potential; VR, voltage ramp.