Journal: iScience

Article Title: Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

doi: 10.1016/j.isci.2024.110888

Figure Lengend Snippet: Transplantation of gut microbiota from aged mice increases susceptibility to arrhythmia (A) Sample ECG traces of four different types of arrhythmic events: ventricular premature beats (VPB), ventricular tachycardia (VT), atrial fibrillation (AF), and atrioventricular block (AVB). (B) Summary the inducibility of VPB, VT, AF, and AVB in young and aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, VT, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. (C) Differences in heart rates, PR intervals, QRS intervals, R amplitude, P duration and P amplitude among young-young FMT, young-aged FMT, aged-aged FMT and aged-young FMT mice ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (D) Representative western blot and quantification of Cx43, Cx40, Nav1.5, Cav1.2, Serca-2A, Kv4.2, IL-6, IL-10, IL-1β, TNF-α, TGF-β, α-SMA, GAPDH in ventricular and atrial tissue of young-young FMT, young-aged FMT, aged-aged FMT and aged-young FMT mice ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (E) Representative micrographs of Cx43 signal in ventricular and Cx40 in stained atrial sections visualized ( n = 6/per group). Cx43 indicates Connexin 43; Cx40, Connexin 40; ISO, isoproterenol; IL-6, Interleukin-6; TNF-α, tumor necrosis factor-α; TGF-β, transforming growth factor β.

Article Snippet: Surface electrocardiogram (ECG) was monitored by P3 plus (Data Sciences International), 1.5% isoflurane-oxygen mixture was anesthetized, and subcutaneous platinum electrode was placed on lead II.

Techniques: Transplantation Assay, Blocking Assay, Western Blot, Staining

Journal: iScience

Article Title: Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

doi: 10.1016/j.isci.2024.110888

Figure Lengend Snippet: Vitexin improved aged related arrhythmia through OLA1-Nrf2 signaling pathway (A) Experimental design for testing the anti-aging effect of vitexin on aged mice induced by 150 mg kg D-gal. (B) Sample ECG traces of three different types of arrhythmic events: ventricular premature beats (VPB), atrial fibrillation (AF), and atrioventricular block (AVB). (C) Summary of inducibility of VPB, AF, and AVB in vehicle, and vitexin treated aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. And differences in heart rates, P-R intervals, QRS intervals, and R amplitude among different group ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (D) The examples of HE, Sirius red staining in the ventricle and atria from different group of mice ( n = 6/per group). Scale bar, 100 μm. Viteixn attenuated fibrosis in aged mice measured by Sirius red staining. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (E and I) Cardiac, serum, colon MDA, SOD and GSH-px levels were quantified using commercial assay kits. ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (F) Representative western blot and quantification of Cx43, Nav1.5, Cav1.2, Serca-2A, Kv4.2, α-SMA, OLA1, Nrf2, GAPDH in ventricle and atria in the four groups ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (G) Experimental design for testing the anti-aging effect of Nrf2 activator and inhibitor on aged mice induced by 150 mg kg D-gal. Summary of inducibility of VPB, AF, and AVB in vitexin, DMF, ML385 treated aged mice. Numbers in parentheses indicate the number of mice that were induced into VPB, AF, AVB following ISO treated ( n = 6/per group). Data analyzed by Fischer’s exact test. (H) The examples of HE, Sirius red staining in the ventricle from different group of mice ( n = 6/per group). Scale bar, 100 μm. Viteixn and DMF attenuated fibrosis in aged mice measured by Sirius red staining. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. Serum levels were quantified using commercial assay kits. ( n = 6/per group). Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. (J) Representative western blot and quantification of Cx43, Nav1.5, Cav1.2, Serca-2A, Kv4.2, α-SMA, OLA1, Nrf2, and GAPDH in ventricle in the four groups ( n = 6/per group). GAPDH was used for internal normalization. Data are presented as the mean ± SD. Data analyzed by one-way ANOVA with Tukey’s post-hoc test. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001.

Article Snippet: Surface electrocardiogram (ECG) was monitored by P3 plus (Data Sciences International), 1.5% isoflurane-oxygen mixture was anesthetized, and subcutaneous platinum electrode was placed on lead II.

Techniques: Blocking Assay, Staining, Western Blot