Fig 1.
Echocardiogram indicates structural and functional differences early in the disease progression.
Structural (A) and functional (B, C) parameters of the heart from WT (n = 8) and BACHD (n = 9) mice were measured from 3 to 15 mo of age. ^ P<0.05 within WT vs. 3 mo. # P<0.05 within BACHD vs. 3 mo. * P<0.05 for genotypic differences.
Table 1.
Echocardiographic parameters in BACHD and WT animals beginning at 3 mo of age.
Fig 2.
Histological analysis finds evidence of fibrosis and hypertrophy in the BACHD hearts.
Examples of Masson’s Trichrome stained heart sections from 15 mo old WT and BACHD mice (A). Quantification of fibrosis by measuring the integrated density of fibrotic tissue and divided by tissue area detected significantly increased areas of fibrosis in BACHD mice (B). Examples of hematoxylin and eosin (H&E) stained heart sections from 15 mo old WT and BACHD mice (C). Morphometry measurements comparing heart weight relative to body weight between 15 mo old WT and BACHD mice (D). * P<0.05 for genotypic differences.
Table 2.
Histological measurements of hearts of 15 mo WT and BACHD mice.
Fig 3.
The cardiovascular system of the BACHD mice responded adaptively to chronic treatment with an adrenoreceptor challenge (ISO, 0.96mg/kg per day for 30 days).
Examples of ECG waveforms from WT (n = 10) (A) and BACHD (n = 8) mice (B). The ST segment range is shown by the black line. ISO increased HR (C) and elevated the ST segment voltage (D) in both genotypes indicating that the drug was effective in stimulating the heart also in BACHD mice. No significant difference in the response to ISO between genotypes was detected. # P<0.05 vs. saline.
Table 3.
Echocardiographic parameters from BACHD and WT animals (6 mo) following chronic administration of isoproterenol (0.97 mg/day for 30 days).
Fig 4.
Histological analysis finds evidence of increased fibrosis in the BACHD hearts in response to the adrenoreceptor challenge.
Examples of Masson’s Trichrome (A) stained heart sections from WT and BACHD mice treated with saline or ISO. Quantification of fibrosis by measurement of the optical density of blue staining confirmed increased fibrosis in the ISO-treated BACHD animals (B). Comparison of heart dimensions from H & E sections (C) and morphological measurements of WT and BACHD (D) mice indicated that the heart weight/body weight ratio was higher in both groups following ISO treatment. However, there were no significant differences between the genotypes. * P < 0.05 between genotypes; # P<0.05 vs. saline within a genotype.
Table 4.
Histological measurements of WT and BACHD hearts following isoproterenol challenge.
Table 5.
Histological measurements in WT and BACHD mice (6 mo) following 12 wks of isoproterenol challenge.
Fig 5.
Network analysis of biologically relevant pathways altered in the heart of BACHD mice vs WT as measured by microarrays.
Most altered gene networks in the comparison between young (3 mo) WT and BACHD hearts (A) and in the comparison between aged (15 mo) WT and aged BACHD (B). Grey boxes indicate that gene expression is increased in BACHD mice, while white boxes indicate decreased expression.
Table 6.
List of top 10 genes up-regulated and down-regulated in BACHD ventricles compared to WT at the same age (n = 4 per group).
Fig 6.
Microarray results were confirmed by probing expression of 4 genes using quantitative real-time PCR from ventricles from mice at 3 mo of age.
Hspa1a (A) and Nppb (B) are both involved in stress and pathological responses and were increased in the BACHD mice. Expression of Kcnip2 (C), a voltage-gated potassium channel interacting protein responsive to changes in calcium, and Acot1 (D) an enzyme involved in fatty acid metabolism were decreased in BACHD ventricles. Data are reported as ratios of the target gene expression to Tbp, and are shown as the mean ± SEM, * P<0.05 for genotypic differences (n = 4 per group).
Fig 7.
Altered inflammatory markers in young BACHD mice.
Levels of chemokines and pro-inflammatory cytokines were measured in the serum of young (3 mo) BACHD and WT mice using a multiplex assay. Significant changes in RANTES (A) and IL-6 (B) levels were found in serum of young WT and BACHD mice. IL-1α (C) levels were not different. Data are shown as the mean ± SEM, * P<0.05 for genotypic differences (n = 8 per group).
Fig 8.
Apoptotic and stress markers are increased in the aged BACHD heart.
A significant increase in Cleaved Caspase 3 (A) and Hsp-70 (B) protein levels was found in whole tissue lysate of the heart of aged BACHD mice. Values derived from the densitometric analysis were corrected for the background, normalized to GAPDH and are shown as a percentage of the value for the WT mice. (C) Protein levels of GAPDH did not differ between WT and BACHD. Insert shows representative immunoblots. Data are shown as the mean ± SEM, * P<0.05 for genotypic differences (n = 4 per group).
Table 7.
List of cardiovascular disease related genes altered in BACHD ventricles compared to WT at the same age.
Table 8.
List of apoptosis related genes altered in BACHD ventricles compared to WT at the same age.