To construct and evaluate a mouse model of pressure overload-induced heart failure with dampness syndrome.

C57BL/6 mice were divided randomly into sham, thoracotomy and aortic restriction (TAC), and TAC-dampness (TAC-D) groups (n = 7 mice per group). Mice in the sham group underwent thoracotomy without aortic constriction, while mice in the TAC group underwent aortic arch constriction to induce pressure overload-induced heart failure. All mice were housed in a normal environment. In addition to TAC surgery, TAC-D mice were placed in a controlled temperature and humidity chamber for 8 h/d to induce dampness syndrome, with the remaining time spent in a normal environment. This protocol was maintained for 8 weeks. The macroscopic manifestations were assessed using the "Evaluation Scale for Dampness Syndrome Animal Models in Traditional Chinese Medicine". Modern medical techniques were employed to measure cardiac function, myocardial histopathology, immune homeostasis, serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), and lipid levels. Fecal 16S rDNA sequencing and serum non-targeted metabolomics were conducted to develop novel evaluation indicators for the heart failure with dampness syndrome mouse model.

Mice in the TAC-D group exhibited fatigue, lethargy, reduced responsiveness to external stimuli, and anal soiling. Mice in both heart failure groups demonstrated marked cardiac dysfunction, myocardial injury, immune homeostasis imbalance, elevated serum NT-proBNP levels, and reduced lipid levels, especially in the TAC-D group. Fecal 16S rDNA sequencing and serum non-targeted metabolomics revealed significant alterations in the gut microbiota and metabolites following dampness syndrome induction. Linear discriminant analysis effect size analysis (> 2) showed that the bacterial genera Enterorhabdus, Eubacterium, Corynebacterium, Christensenellaceae and Erysipelatoclostridium were significantly enriched in the TAC-D group. Metabolomics kyoto encyclopedia of genes and genomes(KEGG) enrichment analysis indicated that differential metabolites in the TAC-D group were primarily enriched in glycerophospholipid metabolism, arachidonic acid metabolism, and bile secretion pathways. Pearson's correlation analysis revealed significant negative correlations between the bacterial genera Eubacterium and Erysipelatoclostridium and metabolites involved in arachidonic acid metabolism, including 16R-hydroxy-5,8,11,14-eicosatetraenoic acid (HETE), 6-keto PGE1, PE-NMe2(16 ∶ 1(9Z)/20 ∶ 3(8Z, 11Z, 14Z)), Prostaglandin F2a, TXB2, Oxoglutaric acid, and 12 (R)-HETE.

The combination of aortic arch constriction and a controlled temperature and humidity environment successfully established a mouse model of pressure overload-induced heart failure with dampness syndrome. The "Evaluation Scale for Dampness Syndrome Animal Models in Traditional Chinese Medicine", cardiac function, serum NT-proBNP, myocardial histopathology, and immune homeostasis can serve as conventional evaluation indicators for this model. Additionally, the incorporation of disturbances in the gut bacterial genera Eubacterium and Erysipelatoclostridium and arachidonic acid metabolism further develops an innovative evaluation system for the heart failure with dampness syndrome mouse model.