British scientists go to the heart of blood vessels

British scientists are developing tiny devices that capture images of signals as they travel the innermost layer of the body's blood vessels - helping to revolutionise the understanding of vascular disease.
Researchers at the University of Strathclyde have received 1.4 million pound (USD 1.47 million) from Wellcome and the British Heart Foundation to develop imaging technology capable of visualising the endothelium - a thin layer of cells which covers the inside of body's entire cardiovascular system.
Professor John McCarron of the Strathclyde Institute of Pharmacy and Biomedical Sciences is leading the research with Dr Calum Wilson, Professor John Girkin and Dr Chris Saunter from Durham University.

"The endothelium is a sophisticated, interconnected signalling network that is similar to a modern communication system. The endothelium continuously monitors blood pressure, blood flow rates and the composition of blood and then sends signals to control virtually all blood vessel functions, such as contraction of the artery, growth of new vessels and blood clotting," McCarron said.
Malfunction of the endothelium underlies almost all vascular diseases including hypertension and atherosclerosis and the vascular changes that occur in diabetes.
"The endothelium is an exceptionally complex sensory system. Although the endothelium is just one cell thick, there are 10 trillion endothelial cells, 100 times more than there are neurons in the brain, in a continuous layer throughout the cardiovascular system. There are 2000 cells per square millimetre.

"It was thought that these cells all operated in the same way. We are now seeing each one has unique properties and senses its environment in a way that is slightly different from its neighbour. Each cell senses only a tiny piece of information but that information is a little different from its neighbours," McCarron said.

The cells pass their pieces of information around so collectively there is a lot of information. The cells use this combined information to make decisions and solve problems as a collective. The behaviour provides a collective intelligence that is far beyond the capabilities of each cell and is like the intelligent behaviour, swarm intelligence, seen in colonies of ants or flocking birds, McCarron said.

Problems in one part of the endothelium are sorted out without needing or affecting other regions. The number of cells in the endothelium is part of its strength and the collective behaviour means the system is a flexible, wide- ranging and fault-tolerant sensing and communication system.
"As it is the innermost lining of blood vessels, the endothelium has been exceptionally difficult to access and study. Our new miniature optical techniques allow us to see the endothelium at work from inside blood vessels and how it senses pressure and chemicals and the communication highways that relay information around the blood vessel.

"These techniques are already providing new understandings of how the endothelium network works normally and malfunctions in disease," McCarron added.