- Joan Josep Cerdà Pino, Antonio Cerrato Casado, Carles Bona Casas and Joan Masso
- The Conversation*
As surprising as it may seem, all of us, including the coldest and harshest, have within us an everlasting romantic who tirelessly caresses and protects us day and night even the smallest and most intimate of our corners, a stranger to most but not without. We could live: the endothelial glycocalyx.
Behind these two words is an organ whose existence was confirmed in mammals shortly before man reached the Moon.
This organ, in an adult human, weighs as much as his brain: approximately 1.4 kilograms. If it were fully deployed, would cover three basketball courts.
What sets it apart from other organs is that it is not found in any specific place in the body. Conversely, is everywhere, in direct contact with blood.
It is similar to a soft layer of velvet that internally covers all arteries and veins in the body, from the largest to the smallest microcapillaries (blood vessels).
The thickness of this velvet coat that we all carry within ranges from one thousandth to one ten thousandth of a millimeter (between 0.1 and 1.0 micrometers).
But don’t be fooled by its size. Although it may seem trifling to be considered a vital organ, the endothelial glycocalyx fulfills a number of critically important missions.
First, acts as a selective barrier letting only certain molecules pass from the blood to the rest of the body and protects us against the loss of fluids (edema).
It also serves as a lubricating layer to transport red blood cells. In the case of microcapillaries, it is especially important, since their opening may be smaller than the size of the red blood cell itself.
In addition, it prevents the erosion of the walls of the veins and arteries and greatly prevents other particles flowing through the blood from sticking together, causing clots and blockages. On the other hand, by capturing certain molecules, it controls the appearance of thrombosis, inflammation and oxidative stress.
Another essential function of the glycocalyx is to send information to the outside of the cells that are part of the walls of the blood vessels (endothelium), so that they modify their shape, size and other properties. It achieves this through the forces exerted by the blood on it.
Thus, blood transport is optimal at all times and under all circumstances. Furthermore, glycocalyx is also involved in regulating the growth and migration of these endothelial cells throughout the body.
Diseases linked to its absence
The vital role of the glycocalyx is revealed when this coating disappears in part or totally. When this happens, the arto haveiosclerosis (accumulation of fats, cholesterol and other substances within the arteries and on their walls) starts quickly and the atheroma plaques quickly block the passage of blood.
Its loss has also been linked to stroke, hypertension, pre-eclampsia, and more serious bacterial infections.
Some bacteria produce toxins that deteriorate the glycocalyx as a strategy to be able to roam freely in each and every corner of the human body.
Investigations carried out in 2019 have found that, in the case of contracting the malariaIf the glycocalyx deteriorates, the patient’s chances of survival drop dramatically.
On the other hand, glycocalyx plays a very important role in growth and tumor cell migration (metastasis), according to recent studies.
Likewise, very solid indications point out that many of the complications that appear over time with diabetes They come from the fact that the disease significantly deteriorates the glycocapillary glycocapillary.
Some examples of this are eye injuries that can lead to blindness, kidney injuries, nerve injuries and small vessels that can lead to diabetic foot and gangrene.
Unknown and vital in equal measure
Thus, glycocalyx has become a therapeutic target to be taken into account in research aimed at curing or alleviating the complications of certain diseases that plague humanity.
But, despite the interest generated, the big problem is that, 55 years after the discovery of glycocalyx in mammals, still a great unknown in many respects.
The initial contempt for its importance, its fragility, its small size and the fact that it is very difficult to observe it in action in live studies are factors that have contributed to the existence of very important knowledge gaps about its operation today.
Nor do we know the mechanisms associated with their disease and how it causes disruptions in the rest of the body.
These shortcomings make the medical advances that occur more the result of slow learning by trial and error than research stimulated by a fundamental understanding of this complex organ.
Undoubtedly, a better understanding of how the glycocalyx complex works would help to substantially accelerate medical advances.
Observation of the glycocalyx by computer simulation
At the University of the Balearic Islands (UIB), in our Advanced Computational Physics research group we have proposed to improve the knowledge we have about glycocalyx and associated diseases.
Given the difficulty of studying and drawing conclusions from live studies, we have decided to address the problem through numerical simulations.
These would allow modeling in great detail how the glycocalyx behaves when it is subjected to the passage of a fluid similar to blood.
To achieve this detailed computer simulation model of the glycocalyx, the first thing to do is to devise and build new algorithms.
The objective is to be able to simulate these large and complicated systems in a reasonable time., with all the necessary detail to obtain reliable and quantitative results.
This has been the first task carried out in our project GLYCOSINWe have obtained the necessary computational tools, which will soon also be available to other interested groups, and with their help we are investigating in detail two basic but poorly understood phenomena.
The first is how glycocalyx modifies the properties of the fluids and red blood cells that circulate inside the microcapillaries.
The second, the role of the glycocalyx in the initiation of the formation of obstructive deposits in the microcapillaries.
These are just a few steps towards a full understanding of the glycocalyx, but they will undoubtedly bring us all firmly closer to the ultimate goal.
* This article was originally published on The Conversation. You can read the original version here.
Joan Josep Cerdà Pino is a professor in the Physics Department of the UIB, Balearic University; Antonio Cerrato Married is assistant professor, and Doctor in Physics of the Balearic University; Carles Bona Casas is a contracted professor and Doctor of Fluid Mechanics, Balearic University; Joan Masso is professor of Theoretical Physics and Director of the ACP group (Advanced Computational Physics), Balearic University.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.