ATLANTA, Aug. 15 (UPI) -- Researchers at Georgia Institute of Technology have developed a new method for measuring force on a molecular scale. The tool allows scientists to measure the forces felt by a single blood molecule during bleeding, and thus, better understand how, when and why platelets trigger blood clotting.
Blood's ability to clot when necessary -- and only when necessary -- is essential to human health. Too much clotting blocks arteries and can trigger heart attacks and stroke. Too little clotting risks excessive blood loss.
The latest research is helping scientists understand how blood platelets sense their surroundings and respond to biomechanical forces. Platelets rely on a special molecule called glycoprotein Ibα, or GPIbα, to receive and recognize mechanical signals. The platelets translate signals into messaging by releasing calcium ions that alter platelets' physical properties like adhesion.
The new tool allowed researchers test how GPIbα responds to various forces, revealing correlations between input signals and output messages.
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Researchers found GPIbα molecules sense forces along two pathways, one domain senses magnitude while the other senses the duration of the applied force. The two pathways affect the type and amount of calcium ions released by the platelet.
When the scientists studied the dual pathways on a plasma protein associated with the bleeding disease known as von Willibrand disease, they found the mutation disrupts the synergy between the two domains.
Von Willibrand disease describes blood platelets' inability to efficiently clot and is associated with symptoms like frequent nosebleeds, bleeding gums and easy bruising.
"For years, researchers had thought that the problem was solely the defect in platelet adhesion," researcher Cheng Zhu said in a news release. "But our research reveals another defect: the mechano-sensing machinery doesn't work well in the presence of this mutation. The platelet just doesn't get the signal that would activate it."
The two newly analyzed GPIbα signalling pathways, or domains, are present in a many other types of proteins. Thus, researchers believe their findings -- detailed in the journal eLife -- are relevant for a variety of biological processes.
