Aldehyde Dehydrogenase 2 Ameliorates Chronic Alcohol Consumption-Induced Atrial Fibrillation through Detoxification of 4-HNE

Figures

• 

  Figure 1. Genotyping and efficacy of Aldehyde dehydrogenase 2*2 knock-in (ALDH2*2 KI) mice. (A) Founder (lane marked by the box) mice containing the KI allele were confirmed by sub-cloning and direct sequencing analysis. [A], G-to-A substitution (B) Decreased ALDH2 enzymatic activities in the livers of the ALDH2*2 KI mice. (C) Decreased ALDH2 protein expression in the heart tissues of the ALDH2*2 KI mice. WT, wild-type; Mt, mutant; RE, restriction enzyme; * p < 0.05, ** p < 0.01, *** p < 0.001.

• 

  Figure 2. Chronic ethanol intoxication of wild-type (WT) and ALDH2*2 KI mice. (A) Representative Western blot and (B) quantification relative to GAPDH of 4-hydroxy-trans-2-nonenal (4-HNE) production in mice hearts with the indicated genotypes before chronic ethanol intoxication. (C) Body weight (BW) and (D) ratio of heart weight (HW) and BW of WT and ALDH2*2 KI mice treated with a liquid diet containing 5% ethanol with and without Alda-1 (20 mg/kg per day) for 10 days, then a single dose of ethanol (5 g/kg BW, 20% ethanol) at day 11. (E) Representative Western blot and (F) quantification relative to GAPDH of 4-HNE production in mice hearts with the indicated genotypes after chronic ethanol intoxication. Each value represents the mean ± SE of at least three independent experiments. KI, heterozygous and homozygous ALDH2*2 KI mice; EtOH, ethanol; * p < 0.05, ** p < 0.01, *** p < 0.001.

• 

  Figure 3. (A) Effect of transesophageal burst pacing on the occurrence of atrial fibrillation (AF) in wild-type and ALDH2*2 KI mice with chronic ethanol intoxication with and without Alda-1 treatment. (B) Effect of Alda-1 treatment on the production of 4-HNE in wild-type and ALDH2*2 KI mice with chronic ethanol intoxication. (A) The inducibility of AF was quantified by the ratio of pacing-induced AF episode in ten pacing bursts in each mouse (n, the number of mice in each experimental group). (B) Representative Western blot and quantification relative to GAPDH of 4-HNE production in mice hearts. Each value represents the mean ± SE of at least three independent experiments. WT, wild-type; KI, heterozygous and homozygous ALDH2*2 KI mice; EtOH, ethanol; * p < 0.05, ** p < 0.01.

• 

  Figure 4. Atrial structural remodeling in wild-type and ALDH2*2 KI mice with chronic ethanol intoxication with and without Alda-1 treatment. (A) Representative confocal images showing the expression of transforming growth factor beta 1 (TGF-β1) and collagen I in the atria of mice. (B) Relative intensities of TGF-β1 and collagen I production were quantified. At least 10 random fields were chosen with scanning and averaging. Data are expressed as mean ± SE. n, the number of fields observed in each quantitative measurement; WT, wild-type; KI, heterozygous and homozygous ALDH2*2 KI mice; EtOH, ethanol, ** p < 0.01, *** p < 0.001.

• 

  Figure 5. Associations between the ALDH2*2 polymorphism (rs671) and oxidative stress and atrial structural remodeling in human AF tissues. (A) Western blot and quantification relative to GAPDH of 4-HNE and ALDH2 expression in the homogenates of atria from AF patients with the indicated rs671 genotypes. Each value represents the mean ± SE of at least three independent experiments. Representative confocal images show 4-HNE (B), reactive oxygen species (ROS) (B), myosin heavy chain (MHC) (C) and collagen I (D) production in the atria of eight AF patients (3 wild-type (WT), 5 rs671 with 3 ALDH2*1*2 and 2 ALDH2*2*2). Relative fluorescence density was quantified (right). At least 10 random fields were chosen with scanning and averaging. N, the number of fields observed in each quantitative measurement; data are expressed as mean ± SE. * p < 0.05, ** p < 0.01, *** p < 0.001.