Activation of AMPK/ACC pathway and accumulation of acylcarnitines caused mitochondrial damage in stored platelets. (A) 50 µM bovine serum albumin–bound [U-¹³C₁₆]-palmitate and 300 µM carnitine were added to the fresh apheresis platelets, and the ¹³C-labeling ratio of succinate, fumarate, or malate in stored platelets was evaluated. n = 3. (B) The levels of phosphorylation of AMPKα, AMPKβ, and ACC (p-AMPKα, p-AMPKβ and p-ACC) in stored human platelets were detected by using western blot analysis. Actin was used as a loading control. (C) Plasma acylcarnitine levels of stored human platelet concentrates were detected. n = 3. (D) The aggregation, apoptosis, MMP, and mtROS levels were measured in platelets stored for 4 days with 10 µM palmitoylcarnitine or 200 µM palmitate combined with 300 µM l-carnitine. n = 3. (E) The aggregation, apoptosis, MMP, and mtROS levels were measured in platelets stored for 6 days with 4 µM AMPKi dorsomorphin 2HCl or 0.5 mM activator AICAR. n = 3. (F) The aggregation, apoptosis, MMP, and mtROS levels were measured in platelets stored for 6 days with 40 µM malonyl-CoA or 10 µM trimetazidine. n = 3. *P < .0332, **P < .0021, ***P < .0002, ****P < .0001. ns, not significant.