Fig 2: Schematic of mechanisms of AGEs–CuCl2-induced cuproptosis via ATF3/SPI1/SLC31A1 pathway in diabetic cardiomyopathy. Excessive AGEs and copper in diabetes upregulated copper importer SLC31A1 through ATF3/SPI1, thereby mediating copper accumulation in cardiomyocytes, disturbing copper homeostasis and promoting cuproptosis. This promoted the decline of Fe–S cluster protein (FDX1, LIAS, NDUFS8 and ACO2) and decreased lipoylation of DLAT- and DLST-aggravated mitochondrial dysfunction in cardiomyocytes and resulted in myocardial dysfunction.

Fig 3: Consensus clustering of hub genes associated with cuproptosis in ulcerative colitis patients. (A) Differences in immune cell infiltration among CuClusterA, CuClusterB, and CuClusterC. (B) Correlation of three cuproptosis-related genes with mucosal immune cells. (C–E) Correlation between high and low expression of DLAT (C), DLD (D), PDHA1 (E), and mucosal immune cells. (F, G) Differences in inflammatory factors among CuClusterA, CuClusterB, and CuClusterC. CuClusterA, cuproptosis-ClusterA; CuClusterB, cuproptosis-ClusterB; CuClusterC, cuproptosis-ClusterC. The asterisk represents the statistical p-values (*p < 0.05; **p < 0.01; ***p < 0.001).

Fig 4: Experimental verification in the UC mouse model. (A) Hematoxylin and eosin-stained sections depicting mouse colonic mucosa in the control and DSS groups. (B) DAI scores increased after acute administration of DSS. (C) Histological inflammation scores increased after DSS treatment. (D–F) The expression levels of DLAT, DLD, and PDHA1 were detected by using real-time quantitative polymerase chain reaction. (G, H)The expression levels of DLAT, DLD, and PDHA1 were detected by Western blot analysis in the UC mouse model. (*p < 0.05; **p < 0.01; ***p < 0.001;****p < 0.0001)

Fig 5: AGEs/ATF3/SPI1/SLC31A1 signaling decreased mitochondrial iron–sulfur cluster protein expression and mitochondrial function. (A,B) mRNA levels of mitochondrial iron–sulfur cluster (Fe–S) gene and Fe/S assembly and export in AC16 cells treated with AGEs, AGEs-Cu or ES–Cu for 24 h. (C) Western blot analysis of lipoylation and oligomerization of DLAT and DLST, LIAS, DLAT, DLST and HSP70 of AC16 cells treated with AGEs or AGEs–Cu. (D) Western blot analysis of iron–sulfur cluster protein in AC16 cells treated with AGEs or AGEs–Cu. (E) Western blot analysis of iron–sulfur cluster protein in AC16 cells overexpressed SPI1 and/or ATF3. (F) Western blot analysis of mitochondrial oxidative phosphorylation complex of AC16 cells treated with AGEs or AGEs–Cu. (G–I) Intracellular ATP content, mitochondrial oxidative respiratory chain complex I and III activity of AC16 cells treated with AGEs or AGEs–Cu. * p < 0.05, ** p < 0.01, *** p < 0.001.