fig8

Figure 8. Impact of RAGE blocker FPS-ZM1, cuproptosis blocker TTM, Cu²⁺ ionophore ES and S100A13 inhibitor AMX on high glucose-evoked cardiomyocyte contractile anomalies in vitro. Adult C57BL/6 mouse cardiomyocytes were maintained in a DMEM medium supplemented with either HG (25.5 mM) or NG (5.5 mM) for 12 h with or without FPS-ZM1 (25 μM), TTM (20 μM), AMX (20 μM), or ES (40 nM) before determination of cardiomyocyte mechanics. (A) Resting cell length; (B) PS; (C) Maximal velocity of shortening (+dL/dt); (D) Maximal velocity of relengthening (-dL/dt); (E) TPS; (F) TR₉₀; (G) Scheme depicting proposed mechanism behind RAGE inhibition-induced benefits against diabetes-induced mitochondrial damage, cuproptosis, and mechanical defect. Diabetes upregulates AGEs, prompting RAGE-dependent RAGE-S100A13 interaction, which facilitates Cu²⁺ binding, favoring cuproptosis and mitochondrial damage, ultimately cardiac remodeling and contractile anomalies. Mean ± SEM, n = 16 cells from 3 mice (A-F) per group, normal distribution was judged via the Shapiro-Wilk test, results were assessed using two-way ANOVA and then Tukey’s post hoc test, ^*P < 0.05 between indicated groups. RAGE: Receptor for AGEs; ES: elesclomol; HG: high glucose; NG: normal glucose; PS: peak shortening; TPS: time-to-peak shortening; TR₉₀: time-to-90% relengthening; AGEs: advanced glycation end products; ANOVA: analysis of variance; TTM: tetrathiomolybdate; S100A13: S100 calcium-binding protein A13; AMX: amlexanox; DMEM: Dulbecco’s Modified Eagle Medium; SEM: standard error of the mean; FDX1: ferredoxin 1; DLAT: dihydrolipoamide S-acetyltransferase; CTR1: copper transporter 1; ATP7B: ATPase copper transporting beta.