The adhesion function of the sodium channel beta subunit (β1) contributes to cardiac action potential propagation
- Rengasayee Veeraraghavan
- Gregory S Hoeker
- Anita Alvarez-Laviada
- Daniel Hoagland
- Xiaoping Wan
- D Ryan King
- Jose Sanchez-Alonso
- Chunling Chen
- Jane Jourdan
- Lori L Isom
- Isabelle Deschenes
- Julia Gorelik
- Steven Poelzing
- Robert G Gourdie
- Virginia Polytechnic University, United States
- Imperial College London, United Kingdom
- Case Western Reserve University, United States
- Virginia Tech, United States
- University of Michigan Medical School, United States
- Case Western Reserve University, Unites States
- College of Science, United States
Figures
Figure 1 with 3 supplements
ID Localization of NaV1.5 and β1.
(A) Representative confocal images of GP left ventricular (LV) sections co-labeled for NaV1.5 (green; top) / β1 (green; bottom) along with N-cad (red). (B) Schematic diagrams, and representative …
Figure 1—figure supplement 1
Validation of NaV1.5 and β1 antibodies.
Representative confocal images of GP LV sections labeled using the novel rabbit (A) anti-NaV1.5 and (B) β1 antibodies in the absence (left) and presence (right) of a peptide corresponding to the …
Figure 1—figure supplement 2
Validation of NaV1.5, β1 antibody specificity.
A dot blot experiment showing NaV1.5 and β1 antibody binding to specifically peptides corresponding to the epitopes against which they were raised. Both antibodies displayed selective affinity for …
Figure 1—figure supplement 3
ID localization of β1 via confocal immunofluorescence.
(A) A confocal image of a transmural section of GP LV labeled for β1 (green), Cx43 (red), and nuclei (blue).
Higher magnification images of en face IDs labeled for (B) β1 (green) along with Cx43 (red), and (C) β1 (green) along with N-cad (red) are also presented.
Figure 2
STORM-RLA quantification of NaV1.5 and β1 localization.
(A) A graph summarizing STORM-RLA analysis of relative localization between clusters of co-labeled proteins. The solid bars indicate clusters with any overlap, the shaded bars represent adjacent …
Figure 3 with 2 supplements
βadp1 – a novel inhibitor of β1-mediated adhesion.
(A) Representative traces (top) and summary plot (bottom) of intercellular junctional resistance measured by ECIS in 1610 β1OX, and 1610 Parental cells (five experimental replicates with two …
Figure 3—figure supplement 1
R85D mutation abrogates βadp1 effects on β1-mediated adhesion.
Effects of βadp1 and βadp1-R85D on the formation of intercellular interactions between sub-confluent 1610 β1OX cells forming into monolayers. The change in resistance over 24 hr from plating in the …
Figure 3—figure supplement 2
βadp1 effects on cell viability.
Normalized viability of rat myocardial (H9C2) cells and 1610 β1OX cells following 24 hr of treatment with βadp1.
Figure 4 with 1 supplement
Modulating β1-mediated adhesion.
(A) A representative confocal image from a GP LV perfused with biotinylated βadp1 (βadp1-b) shows Cx43 (green) and βadp1-b (red) immunosignals. (B) Representative TEM images of GJ and perinexi from …
Figure 4—figure supplement 1
Perinexal ultrastructure in β1-null mice.
(A) Representative TEM images of GJ and perinexi (shaded in red), and (B) summary plots of intermembrane distance at perinexal and non-perinexal sites from WT, and β1-null littermate mice (*, p<0.05 …
Figure 5
βadp1 effects on INa, APs.
(A) Representative INa traces from myocytes during vehicle control, or treatment with βadp1 or βadp1-scr. Current-voltage relationships during treatment with (B) 50, or (C) 100 µM peptides. (D) …
Figure 6 with 2 supplements
βadp1 effects on INa.
(A) Representative confocal image of NRVMs labeled for Cx43 (red) and β1 (green). (B) Paired brightfield and fluorescence images along with an overlay demonstrate Cx43-EGFP fluorescence at …
Figure 6—figure supplement 1
β1 expression in NRVMs.
(A) Confocal images of Cx43 (green) along with β1 (red; left) or N-Cad (red; right) and nuclei (blue) in untransduced and Cx43-EGFP-expressing NRVMs. (B) Confocal images of Cx43 (green), β1 (red), …
Figure 6—figure supplement 2
βadp1 effects on INa at cell-to-cell contacts.
(A) Representative SICM images of the surface of untransduced and Cx43-EGFP expressing NRVMs showing cell-to-cell contact sites under control conditions and following 60 min of treatment with βadp1 …
Figure 7 with 2 supplements
βadp1 effects on cardiac electrophysiology.
(A) Representative traces of volume-conducted ECGs from GP ventricles during control (black) and βadp1 (10 µM; orange) perfusion. The solid gray vertical line marks the start of the QRS in both …
Figure 7—figure supplement 1
VT Incidence.
Spontaneous VT incidence in GP ventricles under control conditions and in the presence of βadp1 (doses indicated on graph) or βadp1-scr (10 µM) [n = 3 hearts/dose/ treatment; *p<0.05 vs. control].
Figure 7—figure supplement 2
βadp1 effects on conduction in iPSC-CMs.
Confocal images of Cx43 (red) co-labeled with (A) NaV1.5 (green) and (B) β1 (green) in monolayers of iPSC-CMs. Insets show higher magnification views of regions highlighted by the dashed white …
Figure 8
Schematic diagram of the cardiac ephapse.
Top. A schematic diagram illustrating the organization of NaV1.5, β1, Cx43 and N-cad to different ID nanodomains. Note that plicate (fascia adherens/area composita) and interplicate (GJ, perinexus) …
Additional files
-
Transparent reporting form
- https://doi.org/10.7554/eLife.37610.020
