Figure 4: Human ASCs Demonstrate Glycolytic Reserve

(A) Respirometry. Adherent human ASCs exhibit increase in glycolysis (ECAR) following inhibition of OxPhos by oligo. One-way ANOVA with Tukey’s post-hoc test was used to determine significance. (B) ATP. Metabolic program restriction to aerobic glycolysis (glucose), OxPhos (pyruvate), or anaerobic glycolysis (DMOG) reveals that OxPhos contributes to ∼23% of cellular ATP in adherent ASCs, in the presence of serum and glucose. Replacement of glucose by pyruvate abolished ATP generation by glycolysis, whereas DMOG abolished ATP generation by OxPhos. Total ATP levels in ASCs cultured in the presence of pyruvate or DMOG/hypoxia were compared individually to total ATP levels in untreated cells (control) using the Student t test. (C) Glycolytic reserve. Inhibition of mitochondrial ATP synthesis in human adipocyte stromal cells (hASCs) by oligo (for 24 h) does not lead to ΔΨm depolarization. Viability is preserved following OxPhos inhibition, confirming the presence of glycolytic reserve in hASCs. Calibration bar represents 50 μm (D) Comparison of energetics in adipocyte stromal cells (ASCs), mesenchymal stem cells (MSCs), CDCs, and neonatal rat ventricular myocytes. A comparison of basal respiration in 4 cell types, namely CDCs, ASCs, MSCs, and neonatal rat ventricular myocytes (NRVMs), revealed the highest OCR (OxPhos) and lowest ECAR (glycolysis) in NRVMs. Statistical significance was assessed using 1-way ANOVA followed by Tukey’s post hoc test. Results are presented as mean ± SD with n = 6; each experiment was repeated 3 times. *p < 0.05. Abbreviations as in Figure 1.