Fig. 4: PKM2 enzymatic activity and glycolytic flux are impaired in senescent cells.
From: PKM2 aggregation drives metabolism reprograming during aging process
a, b Immunoblotting of p21, PKM2 (a) and measurement of PKM2 enzymatic activity via LDH-coupled kinetic assay (b) in HeLa cells treated with 2 μM etoposide (ETO) for three days. n = 3 (technical triplicates), Two-tailed unpaired. c, d Immunoblotting of p21, PKM2 (c) and measurement of PKM2 enzymatic activity via LDH-coupled kinetic assay (d) in HeLa cells treated with 10 μM ETO for 24 h and release for indicated days. n = 3 (technical triplicates), one-way ANOVA. e Measurement of PKM2 enzymatic activity with a commercial kit (K709-100) in HeLa cells treated with 2 μM ETO for three days. n = 3 (biological replicates), Two-tailed unpaired t-test. f–h Immunoblotting of p53, p21 and PKM2 (g) and measurement of PKM2 enzymatic activity via LDH-coupled kinetic assay (f) or using a commercial kit (K709-100) (h) in young, middle and senescent fibroblasts 2BS. n = 3 (f, technical triplicates). n = 3 (h, biological replicates), one-way ANOVA. i Quantification of lactate in the culture medium of HeLa cells treated with 10 μM ETO and released for three days. n = 3 (biological replicates), Two-tailed unpaired t-test. j Quantification of lactate in the culture medium of HeLa cells treated with 100 μM 5-Fluorouracil (5-FU) and released for indicated days. n = 3 (biological replicates), one-way ANOVA, P = 0.0023 (DMSO vs. 5-FU R2). k Quantification of lactate in the culture medium HeLa cells treated with 50 nM Camptothecin (CPT) and released for indicated days. n = 3 (biological replicates), one-way ANOVA, P = 0.0011 (DMSO vs. CPT R2), P = 0.0001 (DMSO vs. CPT R3). l Quantification of lactate in the culture medium of HEK 293T cells treated with 10 μM ETO and released for three days. n = 3 (biological replicates), Two-tailed unpaired t-test, P = 0.0008. m Quantification of lactate in culture medium of young, middle and old fibroblasts 2BS. n = 3 (biological replicates), one-way ANOVA, P = 0.0035 (Young vs. Middle), P = 0.0003 (Middle vs. Senescent). **P < 0.01, ***P < 0.001, ****P < 0.0001. Error bars represent SEM. Source data are provided as a Source Data file.
