Fig. 4: Pharmacological inhibition of ELOVL1 mitigates 1-deoxysphingolipids induced mitochondrial and cellular toxicity.

a Schematic enzymatic reaction catalyzed by ELOVL1 and its inhibition by the small-molecule inhibitor Compound 22 (ELOVL1i; (22); CAS 2761063-99-2). b Quantification of 1-deoxyDHCer (m18:0/xx:y⁺³) species in HeLa cells supplemented with d₃-1-deoxySa and ELOVL1 inhibitor (22) or vehicle control (n = 4, biological replicates). c Cytotoxicity of 1-deoxySa in HeLa cells treated with ELOVL1i (0.25 µM) or vehicle. Data were normalized to vehicle-treated controls and shown as mean±SD (n = 4, separately cultured and treated HeLa cell populations). IC₅₀ values were derived from nonlinear regression analysis with 95% confidence intervals. d Maximal respiration and glycolytic capacity of HeLa cells treated with vehicle, 1-deoxySa (0.5 µM), or 1-deoxySa+ELOVL1i (0.25 µM), measured using a Seahorse XF analyzer. e Oxygen consumption rate (OCR) and f Extracellular acidification rate (ECAR) over time in vehicle- or ELOVL1i (22)-treated HeLa cells following exposure to 1-deoxySa (0.5 µM) measured using a Seahorse XF analyzer. All Seahorse data were normalized to crystal violet staining (CV) performed after the assay to correct for cell number and viability. This normalization was essential, as 1-deoxySa-induced cytotoxicity significantly affects viable cell count and could confound metabolic measurements. Data are shown as mean±SD (n = 4, individual biological replicates). Significance was determined using two-tailed unpaired Student’s t-test with multiple testing correction (two-stage step-up method of Benjamini, Krieger, and Yekutieli). Reported p.adjusted values: p < 0.05 (*), p < 0.01 (**), p < 0.001(***). Exact p-values and statistical source data are provided in Source Data 1. Illustrations were created in BioRender. Hornemann, T. (2025) https://BioRender.com/ifocfkk.