Gut microbiota dysbiosis exacerbates heart failure by the LPS-TLR4/NF-κB signalling axis: mechanistic insights and therapeutic potential of TLR4 inhibition

Figures

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  Fig. 1. The schedule of rat heart failure modeling (ISO 3 mg/kg/d) and TAK-242 (2 mg/kg/d) intervention in rat heart failure

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  Fig. 2. Cardiac function indices in ISO-induced heart failure rats. (A) LVEF was reduced in HF group; (B) LVFS was decreased in HF group; (C) LVESD was increased in HF group; (D) LVEDD was increased in HF group; (E) BNP was elevated in HF group; (F) Representative cardiac ultrasound images: a, control group; b, heart failure group; LVEF: left ventricular ejection fraction; LVFS: left ventricular fractional shortening; LVESD: left ventricular end-systolic diameter; LVEDD: left ventricular end-diastolic diameter; BNP: brain natriuretic peptide. n = 6 in each group, ****P < 0.0001

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  Fig. 3. Effects of TAK-242 on gut microbiota dysbiosis in heart failure rats. (A) Venn diagram of OTUs and average overlapping OTUs among groups; (B) PCoA analysis; (C) NMDS analysis; (D) Phylum-level microbial composition in the three groups; (E) Phylum-level community bar plot in each of the animals; (F) Family-level microbial composition in the three groups; (G) Family-level community bar plot in each animal; (H, I) LEfSe analysis revealing the main differential microbiota among the three groups. Blue represents the microbiota that is relatively enriched in the TAK-242 grou; (J) KEGG pathway differences between TAK-242 and heart failure group

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  Fig. 4. Cardiac function indices in TAK-242-treated rats. (A) LVEF and (B) LVFS were reduced in HF group, while TAK-242 treatment increased LVEF and LVFS. (C) LVESD and (D) LVEDD were increased in HF group, and reduced following TAK-242 treatment. (E) Serum BNP level was elevated in HF group, TAK-242 treatment decreased BNP level. N = 6 in each group, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

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  Fig. 5. TAK-242 decreased serum inflammatory cytokines and LPS concentrations, and alleviated myocardial remodelling in heart failure. (A) Serum inflammatory cytokines concentrations, including IL-1β, IL-17, IL-6 and TNF-α were reduced by TAK-242 treatment. (B) LPS level was increased in HF group, while TAK-242 decreased LPS level. (C) Myocardial HE and Masson staining. In HE and Masson staining, heart failure rats exhibited disordered myocardial alignment, tissue swelling and hypertrophy, and lymphocyte infiltration, which were ameliorated by TAK-242 treatment. Lymphocytic infiltrations were indicated by red arrows. Myocardial fibroses were indicated by black arrows. N = 6 in each group, *P < 0.05, ***P < 0.001

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  Fig. 6. TAK-242 Inhibits TLR4/NF-κB Signalling Pathway Expression (A) Representative band images from immunoblot analysis of cytoplasmic protein expression in each group. The expression levels of TLR4 (B), P-IκBα/IκBα (C), and P-p65/p65 (D) in the myocardial cytoplasm were increased in the HF group, while TAK-242 treatment ameliorated these elevations. (E) Representative band images of nuclear protein P-p65 expression in each group. The expression of P-p65 in the myocardial nucleus was elevated in the HF group, whereas the TAK-242 group significantly reduced the expression of nuclear P-p65 (F). Data are presented as mean ± SD (n = 6 per group). *P < 0.05, **P < 0.01, ***P < 0.001. *P < 0.05, **P < 0.01, ***P < 0.001