Regenerative
Quercetin blocks a clot-worsening protein in mice with deep vein thrombosis
By Life and Health Today Staff, . Life and Health Today.
A study published in the European Heart Journal has identified a molecular chain of events that appears to make deep vein thrombosis worse, and found that quercetin, a naturally occurring plant compound, reduced clot size in mice by interrupting that chain.
Deep vein thrombosis, or DVT, is a blood clot that forms in a deep vein, usually in the leg. It can be dangerous if the clot breaks free and travels to the lungs. The researchers began by analysing blood plasma from DVT patients and healthy controls using a technique called liquid chromatography-mass spectrometry, which separates and identifies proteins in a sample. That analysis flagged a protein called syndecan-4, or SDC4, as being elevated in DVT patients.
What happened next was counterintuitive. When the researchers used mice engineered to lack syndecan-4 entirely, clot formation got worse, not better. The finding suggested that syndecan-4 normally plays a protective role, and that when it is shed from the surface of blood vessel cells, as happens in DVT, that protection is lost.
The mechanism the researchers identified runs through a second protein called Piezo1, a mechanosensitive ion channel, meaning a protein that responds to physical forces on the cell membrane. According to the European Heart Journal paper, syndecan-4 and Piezo1 interact directly, confirmed by a laboratory technique called co-immunoprecipitation. When syndecan-4 is shed, Piezo1 activity increases, which in turn activates a signalling pathway known as PI3K/Akt. That pathway appears to drive a process called endothelial-to-mesenchymal transition, or EndMT, in which the cells lining blood vessels change their character in ways that promote clot growth. Single-cell RNA sequencing, a technique that reads gene activity in individual cells, identified a specific subpopulation of endothelial cells as the main driver of this transition.
The researchers then tested quercetin, a flavonoid compound present in many fruits, vegetables and teas, as a potential Piezo1 inhibitor. In DVT mice, quercetin bound directly to Piezo1 and, at higher doses, reduced Piezo1 expression. It also reduced thrombus size in those mice. The paper reports that the dose-response relationship was confirmed in laboratory cell models.
What this does not show is whether any of this translates to people. The clot-reduction results were in mice, and the cell work was done in human umbilical vein endothelial cells in a dish, which behave differently from cells inside a living person's veins. The paper does not report a human trial. Quercetin is sold as a dietary supplement without regulatory approval for any medical use, and the doses and formulations used in laboratory and animal studies are not the same as what is in commercial products.
The open question is whether blocking Piezo1 in people with DVT would reduce clot burden without disrupting other functions that Piezo1 performs in the cardiovascular system. That would require carefully designed human trials that have not yet been done. Anyone weighing up quercetin supplements in the context of clotting risk should discuss it with a clinician who knows their full medical history, particularly given that DVT is a condition already managed with anticoagulant drugs that carry their own risks.