The stakes are higher than the word platelet might suggest. As people age, their platelets become hyperreactive, aggregating more readily and contributing to the elevated risk of heart attacks and strokes in older adults. Megakaryocytes sit at the origin of that problem. These enormous cells, which can contain up to 64 copies of the genome, undergo a metabolically demanding maturation program before shedding platelets into the bloodstream. Aging impairs their proliferation, differentiation, and quality-control machinery through both intrinsic cellular defects and changes in the bone marrow environment. Yet the precise molecular drivers of megakaryocyte decline during natural aging have remained poorly defined, and no targeted nutritional intervention had been shown to reverse it.

The research team, led by investigators affiliated with the Sun Yat-sen University Health System, took an unusually rigorous approach for a nutrition study. Rather than relying on accelerated genetic aging models, they used naturally aged male C57BL/6J mice, dividing 84 animals into cohorts starting at 1, 9, 15, 19, 21, and 23 months of age. Each cohort received either a control diet or the same diet supplemented with CoQ10 at 550 milligrams per kilogram of chow for 12 weeks, a dose the authors calculate as roughly equivalent to 300 milligrams per day for a 60-kilogram adult. The mice were then analyzed at 4, 12, 18, 22, 24, and 26 months of age, spanning nearly the entire murine lifespan.

The systemic effects of the supplement were clear and age-dependent. CoQ10-treated mice showed reduced levels of reactive oxygen species and malondialdehyde, a marker of lipid peroxidation, along with increased total antioxidant capacity and higher activity of the antioxidant enzymes superoxide dismutase, catalase, and glutathione. Chronic inflammation, the smoldering fire that accompanies aging, also receded: plasma concentrations of the inflammatory cytokines IL-6, TNF-alpha, and IL-1beta were significantly lower in supplemented animals, with IL-1beta dropping as early as 12 months. Circulating klotho, a protein whose decline is closely associated with aging, was modestly preserved, reaching statistical significance at 24 months. Notably, blood levels of ubiquinol and ubiquinone, the two forms of CoQ10, rose most clearly in mice older than 22 months, suggesting the biological effects of supplementation become most pronounced in advanced age, when endogenous CoQ10 availability has waned.

Within the bone marrow, the changes were striking. Colony-forming assays revealed that megakaryocytes from CoQ10-fed mice proliferated more vigorously, forming larger and more numerous colonies at 12, 16, and 18 months. Flow cytometry showed increased proportions of cells expressing the maturation markers CD41 and CD61, and ploidy analysis revealed a shift toward highly polyploid 16N, 32N, and 64N megakaryocytes, the fully mature end-stage cells most capable of platelet production, whereas control animals accumulated predominantly 8N cells. Apoptosis among megakaryocytes, which rises with age, was significantly reduced in the supplemented groups at 22, 24, and 26 months.

The mechanistic thread connecting these improvements was autophagy, the conserved intracellular recycling process by which cells digest damaged proteins and organelles. Autophagic activity declines with age across many tissues, and in the megakaryocytes of naturally aged mice the researchers observed exactly that pattern: the ratio of lipidated LC3-II to LC3-I, a standard readout of autophagosome formation, fell progressively, while the cargo receptor p62 accumulated. Twelve weeks of CoQ10 reversed both markers at nearly every age examined. Because LC3 and p62 were measured under steady-state conditions in the animal experiments, the authors are careful to note that these data indicate altered autophagic activity but do not by themselves prove enhanced autophagic flux in vivo.

To find the molecular link, the team turned to unbiased quantitative proteomics using Astral DIA mass spectrometry on megakaryocytes isolated from 24-month-old mice. Among the proteins upregulated by CoQ10, one stood out: COPS3, a core subunit of the COP9 signalosome, an evolutionarily conserved complex that regulates protein stability by deneddylating Cullin-RING ubiquitin ligases. In fact, the proteomic data showed that COPS3 was the most highly represented protein within the biological process of protein deneddylation, and several other COP9 subunits rose in parallel. Western blotting across the age series confirmed that COPS3 expression declines gradually with age and that CoQ10 supplementation significantly restores it, particularly at 24 months. Because the COP9 signalosome governs ubiquitin signaling, which is intricately intertwined with autophagy regulation, COPS3 offered a plausible bridge between the supplement and the cellular cleaning crew.

Cell-culture experiments in senescent MEG-01 human megakaryocytic cells, driven into senescence with hydrogen peroxide, put the hypothesis to the test. CoQ10 treatment raised COPS3 levels and shifted the autophagy markers in the direction of enhanced flux, and these effects persisted even when autophagy was pharmacologically blocked with LY294002. Critically, when the researchers silenced COPS3 with siRNA, the CoQ10-induced increase in the LC3-II/LC3-I ratio, the reduction in p62, and the improvements in maturation-marker expression and polyploidization were all partially attenuated. A bafilomycin A1 turnover assay, which blocks lysosomal degradation and thereby reveals how much LC3-II is actually being delivered to lysosomes, provided direct evidence that CoQ10 enhances autophagic flux rather than merely causing autophagosomes to pile up. The incomplete rescue after COPS3 knockdown tells an honest story: COPS3 is a functional contributor to CoQ10’s effects, but not their sole mediator, and gain-of-function and rescue experiments remain to be done.

The downstream consequence for platelet biology is perhaps the most clinically tantalizing finding. Collagen-induced platelet aggregation, which rises with age and peaks before declining at the very oldest ages, was significantly suppressed in CoQ10-fed mice from 18 through 26 months. Activation markers CD62P and JON/A, an antibody that reports the active conformation of the integrin alphaIIb-beta3, were similarly reduced. Importantly, these benefits came without apparent costs: platelet counts, reticulated platelet percentages, and tail-bleeding times were unchanged, suggesting the supplement tames platelet hyperreactivity without crippling primary hemostasis. The authors caution, however, that tail-bleeding time is a crude measure of hemostasis and that these results should not be read as evidence that CoQ10 prevents thrombosis in older adults.

The study is candid about its limits. The mechanistic cell work used an induced senescence model rather than primary megakaryocytes, the in vitro CoQ10 concentration of 100 micromolar exceeds what oral supplementation typically achieves in blood, only a single dietary dose was tested, and only male mice were studied, leaving open whether females respond similarly. How CoQ10, a molecule best known for shuttling electrons inside mitochondria, signals to the nucleus to raise COPS3 expression remains unresolved, though prior work showing that CoQ10 modulates Nrf2 and NF-kappaB-dependent transcription offers plausible routes. Even with those caveats, the convergence of a lifespan-scale dietary intervention, proteomic discovery, genetic knockdown, and flux assays makes a compelling case that CoQ10 supports proteostatic resilience in aging megakaryocytes through a COPS3-autophagy axis. For a supplement often dismissed as scientifically soft, that is a remarkably concrete mechanism, and it points toward nutritional strategies for the platelet dysfunction of aging that now deserve proper clinical scrutiny.

Subject of Research: Effects of dietary coenzyme Q10 on age-related megakaryocyte dysfunction via COPS3-mediated autophagy activation

Article Title: Dietary CoQ10 Ameliorates Age‐Related Megakaryocyte Dysfunction via COPS3‐Mediated Activation of Autophagy

Article References: Xu, Y., Mao, Y.-H., Song, F., He, F., Wu, Y., Wang, C., Wang, M., Xie, S., Ni, H., & Yang, Y. (2026). Dietary CoQ10 Ameliorates Age‐Related Megakaryocyte Dysfunction via COPS3 ‐Mediated Activation of Autophagy. Aging Cell, 25(10), Article e70726. https://doi.org/10.1111/acel.70726

Image Credits: AI Generated

DOI: 10.1111/acel.70726

Keywords: coenzyme Q10, megakaryocytes, autophagy, COPS3, COP9 signalosome, aging, platelets, oxidative stress, inflammaging, bone marrow, proteomics, Aging Cell