Oxidative Stress and Inflammatory Modulation of Ca2+ Handling in Metabolic HFpEF-Related Left Atrial Cardiomyopathy

Figures

• 

  Figure 1. (A) Representative example of transthoracic echocardiographic assessment (B-mode) in parasternal long axis view of WT (left) and HFpEF (right) during diastole, yellow circles indicate left atria. (B) Corresponding left ventricular ejection fraction and (C) left ventricular mass (weighed). (D) E/e’ as a measure of diastolic dysfunction (derived from mitral valve flow and tissue Doppler). (E) Left atrial area. Statistical analysis: Student’s t-test. p-values: *1 0.0008, *2 0.016, *3 <0.0001. n-numbers indicate animals.

• 

  Figure 2. (A) Representative example of mitochondrial structure (dye: Mitotracker) in left atrial cardiomyocytes (upper), after thresholding (center) and after contour analysis (lower). (B) Corresponding data of structural perimeter to area ratio as an indicator mitochondrial fission. (C) Representative example of ROS measurements (left; dye: H2DCF) and averaged trace (all cells per group). (D) Corresponding data of ROS production. Statistical analysis: Student’s t-test. p-values: *1 <0.0001, *2 <0.0001. n-numbers indicate cells (from four animals per group).

• 

  Figure 3. (A) Representative example of three consecutive CaT of left atrial cardiomyocytes after 1 h incubation in Tyrode solution (CT; upper), with additional TNF-α (center) or IL-10 (lower; 10 μM, respectively) in WT (left) and HFpEF (right) at 1 Hz electric stimulation (black arrows indicate stimulation triggers). (B) Corresponding CaT amplitude and (C) tau of decay of WT. (D) Corresponding CaT amplitude and (E) tau of decay of HFpEF. Statistical analysis: One-way ANOVA, post-hoc Bonferroni. p-values: *1 <0.0001, *2 <0.0001, *3 0.0175, *4 0.0009. n-numbers indicate cells (from four animals per group).

• 

  Figure 4. (A) CaT time-to-peak (TTP) of left atrial cardiomyocytes in WT and (B) HFpEF after 1 h incubation in Tyrode solution (CT), with additional TNF α or IL-10 (10 μM, respectively). (C) Example visualization of early Ca2+ release (ER) site analysis. (D) Corresponding data of fractional ER sites (E; > 3 ER events in 10 consecutive cycles). (E) Respective probability of ER of ER sites. (F) Standard deviation (SD) of ER sites as a measure of synchrony. Statistical analysis: One-way ANOVA, post-hoc Bonferroni (A,B) or student’s t-test (D–F). p-values: *1 0.015, *2 0.012, *3 0.039. n-numbers indicate cells (from four animals per group).

• 

  Figure 5. (A) Western Blot of TNF-α receptor type 1 (TNF-α R1; upper) and TNF-α receptor type 2 (TNF-α R2; lower) in left atrial myocardial tissue. (B) Corresponding data of TNF-α R1 and (C) TNF-α R2. (D) Western Blot of IL-10 receptor type 1 (IL-10 R1; upper) and IL-10 receptor type 2 (IL-10 R2; lower). (E) Corresponding data of IL-10 R1 and (F) IL-10 R2. Statistical analysis: Student’s t-test. p-values: *1 0.027, *2 0.0005, *3 <0.0001. n-numbers indicate animals.

• 

  Figure 6. Proposed effect of dysfunctional TNFα/IL-10 signaling in cardiomyocytes during metabolic HFpEF-related left atrial cardiomyopathy. Intrinsic inflammation mediates impairment of cellular Ca2+ homeostasis and facilitates enhanced production of reactive oxygen species (ROS).