Related Experiment Video
Updated: Dec 12, 2025
Author Spotlight: Innovative Techniques for ROS Detection and Implications for Platelet Research
Published on: March 29, 2024
Antiplatelet Effect of Carbon Monoxide Is Mediated by NAD+ and ATP Depletion
Patrycja Kaczara1, Barbara Sitek1, Kamil Przyborowski1
1Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland.
Objectives:
Carbon monoxide (CO) produced by haem oxygenases or released by CO-releasing molecules (CORM) affords antiplatelet effects, but the mechanism involved has not been defined. Here, we tested the hypothesis that CO-induced inhibition of human platelet aggregation is mediated by modulation of platelet bioenergetics. Approach and Results: To analyze the effects of CORM-A1 on human platelet aggregation and bioenergetics, a light transmission aggregometry, Seahorse XFe technique and liquid chromatography tandem-mass spectrometry-based metabolomics were used. CORM-A1-induced inhibition of platelet aggregation was accompanied by the inhibition of mitochondrial respiration and glycolysis. Interestingly, specific inhibitors of these processes applied individually, in contrast to combined treatment, did not inhibit platelet aggregation considerably. A CORM-A1-induced delay of tricarboxylic acid cycle was associated with oxidized nicotinamide adenine dinucleotide (NAD+) depletion, compatible with the inhibition of oxidative phosphorylation. CORM-A1 provoked an increase in concentrations of proximal (before GAPDH [glyceraldehyde 3-phosphate dehydrogenase]), but not distal glycolysis metabolites, suggesting that CO delayed glycolysis at the level of NAD+-dependent GAPDH; however, GAPDH activity was directly not inhibited. In the presence of exogenous pyruvate, CORM-A1-induced inhibition of platelet aggregation and glycolysis were lost, but were restored by the inhibition of lactate dehydrogenase, involved in cytosolic NAD+ regeneration, pointing out to the key role of NAD+ depletion in the inhibition of platelet bioenergetics by CORM-A1.
Conclusions:
The antiplatelet effect of CO is mediated by inhibition of mitochondrial respiration-attributed to the inhibition of cytochrome c oxidase, and inhibition of glycolysis-ascribed to cytosolic NAD+ depletion.
Insights
Carbon monoxide (CO) inhibits platelet aggregation by disrupting cellular energy production. This involves blocking mitochondrial respiration and glycolysis through NAD+ depletion, revealing a novel mechanism for CO
Area of Science:
- Biochemistry
- Cellular Physiology
- Pharmacology
Background:
- Carbon monoxide (CO) exhibits antiplatelet effects, but the underlying mechanism remains unclear.
- CO-releasing molecules (CORM) are sources of CO with potential therapeutic applications.
- Understanding CO's impact on platelet function is crucial for developing new antiplatelet strategies.
Purpose of the Study:
- To investigate the hypothesis that CO-induced inhibition of human platelet aggregation is mediated by modulation of platelet bioenergetics.
- To elucidate the specific pathways affected by CO in human platelets.
Main Methods:
- Light transmission aggregometry to measure platelet aggregation.
- Seahorse XFe technique to assess mitochondrial respiration and glycolysis.
- Liquid chromatography-tandem mass spectrometry-based metabolomics to analyze metabolic changes.
- Use of specific enzyme inhibitors and exogenous metabolites to probe pathways.
Main Results:
- CO-releasing molecule-A1 (CORM-A1) inhibited both platelet aggregation, mitochondrial respiration, and glycolysis.
- Inhibition of individual bioenergetic pathways did not significantly affect platelet aggregation, but combined inhibition mimicked CORM-A1 effects.
- CORM-A1 delayed the tricarboxylic acid cycle, leading to oxidized nicotinamide adenine dinucleotide (NAD+) depletion.
- CO-induced glycolysis inhibition occurred at the NAD+-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPDH) step, linked to cytosolic NAD+ regeneration.
- Restoration of platelet aggregation and glycolysis by pyruvate was reversed by lactate dehydrogenase inhibition, highlighting NAD+ depletion's role.
Conclusions:
- The antiplatelet effect of CO is mediated by inhibiting mitochondrial respiration via cytochrome c oxidase.
- CO also inhibits glycolysis by causing cytosolic NAD+ depletion.
- Platelet bioenergetics, particularly NAD+ levels, are key targets for CO's antiplatelet action.
Related Concept Videos
01:20Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
01:27Oxygen Transport in the Blood
01:22Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
01:28Nitric Oxide Signaling Pathway
01:30The Electron Transport Chain
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q...
01:46Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...