Sex Differences in Skeletal Muscle Pathology in Patients With Heart Failure and Reduced Ejection Fraction

Figures

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  Figure 1.. Influence of sex on skeletal muscle transcriptome and myofiber atrophy. A, Schematic of RNA-sequencing protocol for analysis between male (n=6) vs female (n=5) patients with heart failure and reduced ejection fraction (HFrEF) with principle component (PC) analysis plot showing HFrEF with man and woman are clustered into 2 distinct groups. B, DESeq2 analysis revealed 5629 differentially expressed genes (DEGs) were found when men were compared with women (green dots show the most significant DEGs [log2-fold change >1.5 or <−1.5] and yellow dots show smaller DEGs [log2-fold change >−1.5 or <1.5]) or <1.5])with significance threshold set at adjusted P<0.05 (Padj) corrected using Benjamini and Hochberg method. The Gene Ontology analysis of biological process with the top-10 terms by significance (adjusted P<0.05) for the upregulated (C) and downregulated (D) DEGs, as plotted by the gene count of the identified term. E, Representative images of pectoralis major skeletal muscle sections for males (M) including controls (CON; n=12) or HFrEF (n=10) and females (F) including CON (n=10) and HFrEF (n=8) with sections stained for fiber types (type I, red; type IIa, green; and type IIx,…

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  Figure 2.. Influence of sex on skeletal muscle phenotype and capillarity. Muscle phenotype assessing fiber type proportion (A) and fiber areal density (B) including males (M) control (CON; n=12) or heart failure with reduced ejection fraction (HFrEF; n=10) and females (F; CON; n=5) or HFrEF (n=6). Representative stained muscle capillarity sections (white circles; C) with quantification of total, type I–, and type II–specific capillary-to-fiber (D) and capillary density (E). F, mRNA expression of molecular regulators of fiber phenotype in males (CON: n=9; HFrEF: n=10) and females (CON: n=8; HFrEF: n=10). G, Representative immunoblots in males (CON: n=7; HFrEF: n=7) and females (CON: n=7; HFrEF: n=7) with GAPDH (glyceraldehyde 3-phosphate dehydrogenase) used as loading control, with samples denoted by 1: male CON; 2: HFrEF with man; 3: female CON; and 4: HFrEF with woman. Quantified protein expression for total PGC1α (peroxisome proliferator-activated receptor-gamma coactivator 1 alpha; H), phosphorylated to total AMPK (AMP-activated protein kinase; I), phosphorylated to total MEF2D (myocyte enhancer factor 2D; J), and total calcineurin (K). Data are presented as min-max box plots with median…

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  Figure 3.. Influence of sex of circulating inflammatory factors in serum. Analysis of systemic proinflammatory cytokines (A), cytokines (B), and chemokines (C) in serum collected from men (M) and women (F), either control (CON) or heart failure with reduced ejection fraction (HFrEF; n=5 per group). Data are presented as minimum-maximum box plots with median and quartile ranges denoted by the box, the mean denoted by the + symbol, and individual points plotted. *P<0.05 denotes interaction between sex and HFrEF, †P<0.05 denotes effect of sex, ‡P<0.05 denotes effect of HFrEF, and #P<0.05 denotes within-sex difference (unpaired t test). HF indicates heart failure; IFN, interferon; IL, interleukin; IP-10, interferon-γ-inducible protein 10; MCP, monocyte chemoattractant protein; MDC, C-C motif chemokine 22; MIP, macrophage inflammatory protein; TARC, CCL17/CC motif chemokine ligand 17; TNF, tumor necrosis factor; and VEGF, vascular endothelial growth factor.