Fig 1.
Identification of differentially expressed genes (DEGs) in the heart failure (HF) dataset GSE57345.
(A) Volcano plot of differential transcriptome analysis (P < 0.05, |log2FC| > 0.4). (B) Heatmap showing hierarchical clustering and expression patterns of DEGs in control and HF groups.
Fig 2.
Enrichment analysis of DEGs in HF.
(A) KEGG pathway enrichment analysis. (B) Functional enrichment network visualization. (C) ssGSEA results of metabolic KEGG pathways. (D) GO enrichment analysis showing representative biological processes.
Fig 3.
Expression profiles of HF-related metabolic pathways.
Heatmaps showing gene expression levels involved in (A) primary bile acid biosynthesis, (B) beta-alanine metabolism, (C) lipoic acid metabolism, (D) histidine metabolism, and (E) lysine degradation pathways.
Fig 4.
Hub genes identified using WGCNA.
(A) Clustering dendrogram of module eigengenes.(B) Merged dynamic tree cut showing distinct modules. (C) Module–trait correlation heatmap. (D) KEGG enrichment of the ME-CYAN module. (E) PPI network of ME-CYAN hub genes. (F) KEGG enrichment analysis of hub genes.
Fig 5.
Identification of candidate biomarkers for HF.
(A) Boxplots of hub gene expression in control and HF samples. * P < 0.05, ** P < 0.01, *** P < 0.001. (B) ROC curves assessing the diagnostic performance of hub genes. (C) Random forest ranking showing STAT1 as the top classifier.
Fig 6.
Immune cell infiltration analysis in HF and control groups.
(A) Distribution of immune cell types in the HF group. (B) Distribution of immune cell types in the control group. (C) Boxplots showing immune cell subsets with significant differences between groups. *P < 0.05, **P < 0.01, ***P < 0.001.
Fig 7.
Single-cell transcriptomic analysis reveals altered macrophage subset composition in failing hearts.
(A) UMAP of major cell populations. (B) Dotplot of canonical marker gene expression. (C) Proportion of cell types across clinical groups (Control, DCM, ICM_MI, ICM_NMI). (D–E) UMAP and clustering of myeloid cells identifying M0, M1, M2, and Cycling myeloid subsets. (F) Marker gene expression patterns of each macrophage subset. (G) Distribution of M0/M1/M2 subsets across groups.
Fig 8.
Single-cell transcriptomics highlight alterations in signaling pathways across cell types in failing myocardium.
(A–B) IFNA pathway scores and group comparisons. (C–D) IFNG pathway scores and group comparisons. (E–F) JAK and JAK–STAT pathway scores and group comparisons. (G–H) STAT1-related scores and group comparisons. *P < 0.05, **P < 0.01, ***P < 0.001.
Fig 9.
Single-cell transcriptomic scoring of signaling pathways in macrophage subsets.
(A–B) IFNA pathway scores in M0, M1, M2, and Cycling myeloid subsets. (C–D) IFNG pathway scores and group comparisons. (E–F) JAK and JAK–STAT pathway scores and group comparisons. (G–H) STAT1 module scores and group comparisons. *P < 0.05, **P < 0.01, ***P < 0.001.
Fig 10.
Histological and molecular evidence of the cardioprotective effects of dapagliflozin in HF rats.
(A) Representative H&E staining of myocardial sections from CK, HF, and HF + DAPA groups showing tissue architecture and inflammatory infiltration changes. (B) Myocardial STAT1 protein levels detected by Western blot. (C) Flow cytometric analysis of macrophage polarization (M1: CD86⁺, M2: CD163⁺). (D) Serum total bile acid (TBA) concentrations in different groups. Data are presented as mean ± SD. Statistical analysis was performed using unpaired two-tailed Student’s t-test; *P < 0.05, **P < 0.01, ***P < 0.001.
Fig 11.
Dapagliflozin reduces STAT1 expression and alleviates myocardial cell injury in vitro.
(A) Verification of STAT1 overexpression in H9C2 cells. (B) Effects of STAT1 overexpression on H9C2 cell viability (CCK‑8 assay). (C) Flow cytometric analysis of apoptosis in STAT1-overexpressing cells. (D) STAT1 protein expression after DAPA treatment in STAT1-overexpressing cells. (E) Rescue of cell viability by DAPA. (F) Reduction of apoptotic cell fractions following DAPA treatment. Data are shown as mean ± SD. Statistical comparisons were conducted using unpaired two-tailed Student’s t-test; *P < 0.05, **P < 0.01, ***P < 0.001.