¹³C Metabolic Flux Analysis in Resting and Thrombin Activated Platelets
Cara L. Sake, Ph.D. Candidate
Colorado School of Mines
Golden, Colorado, U.S.
On Sunday, July 18, 2021, Cara Sake of the Colorado School of Mines presented results from research aimed at generating the first metabolic flux map of resting and thrombin-activated platelets based on intracellular isotope profiling. Why? The global measurements of extracellular uptake and excretion to date have not measured the rate (i.e., flux) of metabolites through different pathways.
Isotope-assisted metabolic flux analysis (13C-MFA) was used to quantify intracellular metabolism in washed human platelets, as Sake commented. The observation made was that resting washed human platelets demonstrate active glycolysis and primarily metabolize glucose anaerobically, producing lactate. A small proportion (<10%) of the glycolytic flux is shunted through the pentose phosphate pathway. Energy requirements are balanced via oxidative ATP production in the citric acid cycle from non-glucose carbon sources. Platelets activated with 1 U/mL thrombin show increases in flux through all major pathways. Thrombin-activated platelets still maintain a glycolytic phenotype where >80% of glucose uptake contributes to lactate formation and excretion.
Sake was proud to champion and develop a 13C-MFA workflow for quantifying the intracellular metabolic flux in platelets, suggesting a new tool for researchers to have in their armamentarium for probing changes in platelet metabolism at the reaction level as a function of agonist and/or environmental conditions.