Changes of Metabolic Phenotype of Cardiac Progenitor Cells During Differentiation: Neutral Effect of Stimulation of AMP-Activated Protein Kinase

Abstract

Cardiac progenitor cells (CPCs) in the adult mammalian heart, as well as exogenous CPCs injected at the border zone of infarcted tissue, display very low differentiation rate into cardiac myocytes and marginal repair capacity in the injured heart. Emerging evidence supports an obligatory metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS) during stem cells differentiation, suggesting that pharmacological modulation of metabolism may improve CPC differentiation and, potentially, healing properties. In this study, we investigated the metabolic transition underlying CPC differentiation toward cardiac myocytes. In addition, we tested whether activators of adenosine monophosphate-activated protein kinase (AMPK), known to promote mitochondrial biogenesis in other cell types would also improve CPC differentiation. Stem cell antigen 1 (Sca1 +) CPCs were isolated from adult mouse hearts and their phenotype compared with more mature neonatal rat cardiac myocytes (NRCMs). Under normoxia, glucose consumption and lactate release were significantly higher in CPCs than in NRCMs. Both parameters were increased in hypoxia together with increased abundance of Glut1 (glucose transporter), of the monocarboxylic transporter Mct4 (lactate efflux mediator) and of Pfkfb3 (key regulator of glycolytic rate). CPC proliferation was critically dependent on glucose and glutamine availability in the media. Oxygen consumption analysis indicates that, compared with NRCMs, CPCs exhibited lower basal and maximal respirations with lower Tomm20 protein expression and mitochondrial DNA content. This CPC metabolic phenotype profoundly changed upon in vitro differentiation, with a decrease of glucose consumption and lactate release together with increased abundance of Tnnt2, Pgc-1a, Tomm20, and mitochondrial DNA content. Proliferative CPCs express both alpha1 and-2 catalytic subunits of AMPK that is activated by A769662. However, A769662 or resveratrol (an activator of Pgc-1a and AMPK) did not promote either mitochondrial biogenesis or CPC maturation during their differentiation. We conclude that although CPC differentiation is accompanied with an increase of mitochondrial oxidative metabolism, this is not potentiated by activation of AMPK in these cells.

PFKFB3-mediated glycometabolism reprogramming modulates endothelial differentiation and angiogenic capacity of placenta-derived mesenchymal stem cells

“…PFKFB3, also termed placental PFK-2 [41,42], has the highest kinase activity than bisphosphatase activity (700-fold), thus most favoring the catalytic activity to glycolysis [74]. Reportedly, PFKFB3 is involved in the differentiation of macrophages, myofibroblasts, and cardiac progenitor cells [75][76][77]. In this study, PFKFB2, PFKFB3, and PFKFB4 are all significantly induced, indicating that the upregulated PFKFB3 represented the augmented glycolytic flux in the endothelial differentiation of PMSCs.…”

Metabolic shift and the effect of mitochondrial respiration on the osteogenic differentiation of dental pulp stem cells

“…The metabolic shift is essential in regulating cellular function, particularly stem cell self-renewal, pluripotency, and plasticity ( Andre et al, 2019 ). Mitochondrial biogenesis and metabolic shifts toward OXPHOS are deemed early events in multiple stem cell differentiation processes ( Khacho & Slack, 2018 ; Wanet et al, 2015 ).…”

AMPKβ1 and AMPKβ2 define an isoform-specific gene signature in human pluripotent stem cells, differentially mediating cardiac lineage specification

“…Furthermore, a timedependent regulation of AMPK activity that might take place during embryonic development is probably not equally adapted in a cell culture model. Along this line, it was shown recently that pharmacological activation of AMPK in cardiac progenitor cells under differentiation is neither sufficient to alter gene expression of differentiation and CM markers, nor to promote PPARGC1A transcription and mitochondrial biogenesis (70). A recent publication suggest increase in AMPK activation during cardiac differentiation of hiPSCs, reaching highest levels of phosphorylation at day 9 and 11 followed by a drop of protein activation at day 14 (71).…”