Fig 1: LA promotes ISCU autophagy degradation, thereby inhibiting iron-sulfur cluster synthesis.a IF staining of chondrocytes treated with LA (red-ISCU, yellow-TOM20, green-lipid droplet), and b ISCU (duplicate well’s n = 10) as well as lipid droplet quantification (cell count, n = 30/ per group). Scale bar is 10 μm. c Western blot analysis of ISCU in chondrocytes treated with LA with concentration gradients (0–400 μM) and d its quantification (biological replicates, n = 3). e The mRNA level of ISCU in chondrocytes treated with LA with concentration gradients (0–400 μM; biological replicates, n = 3). f Western blot analysis of ISCU in chondrocytes treated with NC or LA treatment combined with CHX of varying durations and its quantitative curve (biological replicates, n = 3). g Western blot analysis of ISCU in chondrocytes treated with NC or LA treatment combined with CQ or MG132 and its quantification (biological replicates, n = 3). h IF staining of chondrocytes treated with LA (red-ISCU and green-LAMP2) and its colocalization analysis. i Iron-sulfur cluster assembly on ISCU in the presence of IscS, Fe(NH4)2(SO4)2 or LA. j Lipid ROS staining (scale bar is 100 μm) of chondrocytes treated with LA or combined with ISCU upregulation and k its quantification (duplicate well’s n = 5). l Fe²⁺ staining (scale bar is 100 μm) of chondrocytes treated with LA or combined with ISCU upregulation and m its quantification (duplicate well’s n = 5). n The MDA and o GSH levels of chondrocytes treated with LA or combined with ISCU upregulation (duplicate well’s n = 5). Data are presented as mean ± SD. Statistical significance was determined by two-sided Student’s t test (b, f), one-way ANOVA (d, e), and two-way ANOVA (g, k, m–o).