Journal: European Heart Journal

Article Title: Left bundle branch vs biventricular pacing: mechanistic insights from a canine model

doi: 10.1093/eurheartj/ehaf1093

Figure Lengend Snippet: Molecular targets in cardiac remodeling by BiVP and LBBP. Western blotting results of BNP, TGF-β, KCNIP2, SERCA2a, Cx43, ANKRD1 protein expression (A, C, E) in septum and LV lateral walls from NC, DHF, and BiVP and LBBP groups, and relative protein expression (B, D, F). Represented images and statistical data (G) of cardiac fibrosis detected using Masson's staining. † P < .05 between septal and lateral walls. Abbreviations as in

Article Snippet: The levels of several key proteins were examined using western blot, including ANKRD1 (Proteintech, 11427-1-AP), BNP (Abclonal, A23996), Cx43 (Proteintech, 26980-1-AP), GSNOR (Proteintech, 66193-1-Ig), GLUD1 (Proteintech, 14299-1-AP), KCNIP2 (Abclonal, A7100), SERCA2a (Abclonal, A0098), TGF-β (Proteintech, 81746-2-RR), and GAPDH (Proteintech, 10494-1-AP).

Techniques: Western Blot, Expressing, Staining

Journal: European Heart Journal

Article Title: Left bundle branch vs biventricular pacing: mechanistic insights from a canine model

doi: 10.1093/eurheartj/ehaf1093

Figure Lengend Snippet: Overview of the key findings. This study compares the treatment efficacy of LBBP and BiVP, and relating electrocardiographic, echocardiographic and cellular (reverse) remodeling in a canine DHF model. The results show that LBBP restores electrical synchrony (QRSd) to a similar extent as BiVP, while leads to larger LV-GLS improvement than BiVP. Both LBBP and BiVP reverse the protein level of KCNIP2, SERCA2a and Cx43. Moreover, LBBP reverses abnormalities in cytoskeleton-associated proteins, TGF-β signaling, and SERCA2a expression more than BiVP, as well as enhances myocardial energy metabolism via more efficient TCA cycling and ATP production. ANKRD1, ankyrin repeat domain 1; ATP, adenosine triphosphate; BiVP, biventricular pacing; BNP, B-type natriuretic peptide; Cx43, connexin 43; DHF dyssynchronous heart failure; ECG, electrocardiogram; echo, echocardiogram; GLUD1, glutamate dehydrogenase 1; GSNOR S-nitrosoglutathione reductase; KCNIP2, potassium voltage-gated channel interacting protein 2; LBBP, left bundle branch pacing; LV-GLS, left ventricular global longitudinal strain; NC, normal control; SERCA2a, sarcoplasmic/endoplasmic reticulum Ca 2+ ATPase 2a; TCA, tricarboxylic acid; TGF-β, Transforming growth factor-β.

Article Snippet: The levels of several key proteins were examined using western blot, including ANKRD1 (Proteintech, 11427-1-AP), BNP (Abclonal, A23996), Cx43 (Proteintech, 26980-1-AP), GSNOR (Proteintech, 66193-1-Ig), GLUD1 (Proteintech, 14299-1-AP), KCNIP2 (Abclonal, A7100), SERCA2a (Abclonal, A0098), TGF-β (Proteintech, 81746-2-RR), and GAPDH (Proteintech, 10494-1-AP).

Techniques: Expressing, Control

Journal: bioRxiv

Article Title: Intercellular Communication via Mitotic Nanotubes is Influenced by Connexin-43 Trafficking and Actin Remodeling

doi: 10.64898/2026.02.08.704470

Figure Lengend Snippet: (A) Confocal immunocytochemical image of fixed cells stained to visualize endogenous Cx43 (green) and nuclei (blue). (B) Confocal live-cell image of cells transfected to express mEmerald-Cx43 (green) and the plasma membrane marker mCherry-CAAX (magenta). (C and C’) Confocal live image of cells transfected to express Halo-Cx43 (green), shown with (C) or without (C’) DIC overlay. (D and E) Transmission electron micrographs of a gap junction plaque (D) and an annular gap junction (E) in which the typical pentalaminar membrane morphology can be distinguished. In A-E, solid arrows represent gap junction plaques; dashed arrows represent the invaginated region of the gap junction plaque; arrowheads represent annular gap junctions. (F) Cells in various cell cycle stages were fixed and stained to visualize actin (magenta), Cx43 (green), and nuclei (blue). (F’) Enlargements of mitotic nanotubes in outlined areas in F to show association with Cx43-positive structures (arrows). (G) Cellular distribution of Cx43-positive structures across cell cycle stages. The bar graph represents the mean total area of Cx43 structures per compartment per cell ± SEM. Across 3 experiments, 79 cells were analyzed, with n ≥ 8 per cell cycle stage. (J) Micrograph of a membrane extension that forms a bridge between two cells. The extension is closed at the distal end (J’) where it makes contact with another cell. Contact sites shown in A (boxes J’ and J’’) were magnified to show the typical gap junction plaque membrane. (J’) Contact site between the closed end of the membrane extension and the adjacent cell. (J’’) Contact site between an area along the length of the membrane extension and the tip of another membrane extension. Scale bars = 5µm (A, F, F’), 10µm (B, C, C’), 100nm (D, E), 2µm (J), 100nm (J’, J’’).

Article Snippet: Plasmids encoding the gap junction markers mEmerald-Cx43 (Addgene, Watertown, MA, plasmid #54055) and Halo-Cx43 were gifts from Michael Davidson and John O’Brien, respectively.

Techniques: Staining, Transfection, Clinical Proteomics, Membrane, Marker, Transmission Assay

Journal: bioRxiv

Article Title: Intercellular Communication via Mitotic Nanotubes is Influenced by Connexin-43 Trafficking and Actin Remodeling

doi: 10.64898/2026.02.08.704470

Figure Lengend Snippet: (A) Time-lapse of gap junction plaque turnover in dividing and non-dividing cells. Gap junction plaques were monitored between pairs of interphase cells that later underwent mitosis (Dividing Cells) and pairs of interphase cells that did not divide over ≥ 16 hours of imaging (Nondividing Cells). Large plaques were present at cell-cell contacts at t=0 in both cell pair types (arrows). However, plaque internalization occurred more frequently, resulting in more annular gap junctions in the cytoplasm (arrowheads) of dividing cells than in non-dividing cells. In the montage shown, new annular gap junctions were similarly distributed between the cytoplasm of both cells (Cells 1 and 2). However, among the dividing cells, annular gap junctions were predominantly released into the cell that initially underwent mitosis, compared with the cell that divided later (Cell 4). After 80 minutes, little to no gap junction plaques remained at the surface of the dividing cells, whereas plaques between non-dividing cells showed no apparent change in size. (B) Time-lapse of gap junction dynamics as cells enter, undergo, and exit mitosis. Cells initially in interphase (t = 0:00) were observed to change shape, from flat to round (t = 9:20) and then divide to form daughter cells (t = 10:55) that flattened as they entered interphase (t = 14:40). New gap junction plaques were observed between daughter cells (t=14:40; also enlarged and shown with green channel only). (C) Gap junction plaque internalization into interphase cells in B. The gap junction plaque area has been enlarged, and the mEmerald channel (Cx43) is shown only. The mEmerald channel (Cx43) is shown only at 5-minute intervals for the first 1:20. Solid arrows follow the release of one annular gap junction over time, while dashed arrows follow the release and fission of a second annular gap junction. (D) Mitotic cell nanotubes from an area in B (t = 9:10) that has been enlarged to show Cx43-positive structures (arrows) visible along the mitotic nanotube as well as at both ends of the nanotube. (E) Mitotic nanotube changes shown with three-dimensional rotation of the images in A (t = 8:45 - 9:10). Note the change in Cx43-positive structure distribution within nanotubes over time and that the mitotic nanotubes remained above the substrate. Cells shown were synchronized, transfected to express mEmerald-Cx43 (green) and mCherry-CAAX (magenta), and imaged at 5-minute intervals. Scale bars = 5µm (A, C, D); 10µm (B, E).

Article Snippet: Plasmids encoding the gap junction markers mEmerald-Cx43 (Addgene, Watertown, MA, plasmid #54055) and Halo-Cx43 were gifts from Michael Davidson and John O’Brien, respectively.

Techniques: Imaging, Transfection

Journal: bioRxiv

Article Title: Intercellular Communication via Mitotic Nanotubes is Influenced by Connexin-43 Trafficking and Actin Remodeling

doi: 10.64898/2026.02.08.704470

Figure Lengend Snippet: (A) Mitotic nanotubes in the area between a rounding mitotic cell and a neighboring cell. The solid arrow (0-34 min) represents a linear Cx43-positive structure within the mitotic nanotube. With time, the Cx43-positive structure elongates (0-26 min), fragments (30 min), and moves toward the dividing cell (34 min) before being lost from view (38 min). (B) Transfer of a Cx43-positive structure via mitotic nanotubes. A Cx43-positive structure (arrowhead), which resembles an annular gap junction, moved between two cells and changed shape within the mitotic nanotube before entering the cytoplasm. Some Cx43-positive material remained at one end of the mitotic nanotube (arrows). (C) Movement of a Cx43-positive structure along a mitotic nanotube. A mitotic-nanotube-associated Cx43 structure (arrows), initially at one end of the mitotic nanotube (0 min), moves along a straight path toward the other cell (1.5-10.5 min) and eventually enters the cytoplasm of the other cell (13.5 min). In this figure, cells were transfected to express mEmerald-Cx43 (green) and mCherry-CAAX (magenta) and confocal Z-stacks (step size = 0.25µm) were captured at 4-minute (A) or 1.5-minute intervals (B, C). Scale bars = 5µm (A, C); 2.5µm (B).

Article Snippet: Plasmids encoding the gap junction markers mEmerald-Cx43 (Addgene, Watertown, MA, plasmid #54055) and Halo-Cx43 were gifts from Michael Davidson and John O’Brien, respectively.

Techniques: Transfection