#thrombus

Picking at Scabs

Seeing blood after injury can be alarming. But bleeding is the start of a healing process that’s more than meets the eye. This blood clot, or thrombus, fills the hole left by a puncture wound. It protects against infection and grows crusty over time – maybe into a scab that looks ripe for the picking. But here scientists are looking at what’s going on underneath. A kind of 3D scanning electron microscopy reveals the thrombus builds on a foundation of blood platelets outside of a wound (highlighted in green) which climb into the vessel (blue) as tiny 'pillars'. Eventually they form a vaulted structure a bit like a gazebo, which supports a 'roof' of looser platelets (yellow) inside the vessel. These intricate structures may help to coordinate vital chemical signals during healing. While researchers investigate the effects of drugs and lifestyle on this bloody architecture – let’s leave those scabs alone!

Written by John Ankers

Video from work by Sung Rhee and Irina D. Pokrovskaya, and colleagues

Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Communications Biology, September 2021

Viruses and Clots

With a viral infection comes an increased risk of a heart attack, caused by a clot blocking blood flow to the heart. But why isn’t clear. Key to formation of blood clots are the circulating platelets and so researchers looked to see how they behave during a viral infection. Here, electron microscopy reveals flu virus particles (dark spheres) being engulfed by a platelet, watched over time until the virus is completely internalised (bottom right). Engulfing the virus makes the platelets release a chemical called C3 which causes immune cells called neutrophils to release their DNA. This act is thought to be beneficial as it prevents viruses commandeering that genetic code for their own replication. However, there’s a downside: these broken, sticky neutrophils aggregate with the platelets. It’s these clumps that may be contributing to the higher chance of a heart attack.

Written by Lindsey Goff

Image adapted from work by Milka Koupenova and colleagues

University of Massachusetts Medical School, Department of Medicine, Division of Cardiovascular Medicine, Worcester, MA, USA

Image originally published under a Creative Commons Licence (BY 4.0)

Published in Nature Communications, April 2019

Thrombose erkennen: Sechs Warnzeichen, die vom Bein ausgehen | www.ceboz.com

Sulforaphane from Broccoli: A Stroke-Preventing Superstar | www.ceboz.com

血中で血小板が血栓を作る様子を捉えた映像です。 血小板は緑色蛍光タンパク質（GFP）で標識されており、血栓が緑色の塊として見えています。