From the Guidelines
The endothelial glycocalyx is a critical component of vascular health, and its degradation is associated with coagulopathy in trauma patients. The endothelial glycocalyx is a gel-like layer that coats the inner surface of blood vessels, lining the endothelial cells that form the vessel walls, as described in the context of traumatic coagulopathy 1. It consists of proteoglycans, glycoproteins, and glycosaminoglycans that create a mesh-like structure extending into the vessel lumen. This structure serves several critical functions in vascular health, including:
- Regulating vascular permeability by controlling what substances can pass through vessel walls
- Helping maintain proper blood flow by creating a smooth surface that reduces friction
- Mediating interactions between blood cells and vessel walls
- Participating in inflammatory responses
- Acting as a mechanosensor, detecting changes in blood flow and pressure and triggering appropriate cellular responses 1. Damage to the glycocalyx is associated with various pathological conditions, and its integrity is essential for normal vascular function, with degradation contributing to endothelial dysfunction and subsequent cardiovascular disease, as well as coagulopathy in trauma patients 1.
From the Research
Definition and Composition of Endothelial Glycocalyx
- The endothelial glycocalyx is a complex carbohydrate-rich layer covering the luminal surface of endothelial cells (ECs) 2
- It is a network of membrane-bound proteoglycans and glycoproteins, covering the endothelium luminally, and includes both endothelium- and plasma-derived soluble molecules 3
- The glycocalyx is comprised of proteoglycans, glycoproteins, and glycolipids, and is negatively charged 4
Functions of Endothelial Glycocalyx
- The endothelial glycocalyx plays a crucial role in vascular physiology and pathology, including mechanotransduction, hemostasis, signaling, and blood cell-vessel wall interactions 3
- It has anti-inflammatory and anti-coagulant properties, and its preservation is important to avoid disease initiation and progression 2
- The glycocalyx is involved in controlling angiogenesis and regulating inflammatory responses 4
Damage and Degradation of Endothelial Glycocalyx
- Damage to the glycocalyx precedes vascular pathology, and can be caused by hypervolaemia, hyperglycaemia, and other factors 5
- Degradation of the endothelial glycocalyx is associated with increased morbidity and mortality, and is a central role in many critical illnesses 6
- Shedding of the glycocalyx can be prevented by maintaining a physiological concentration of plasma protein, particularly albumin 5
Therapeutic Interventions and Future Directions
- Possible therapeutic interventions aiming at preserving or restoring the endothelial glycocalyx are being considered, including interventions to protect or repair the glycocalyx 5, 2
- First trials that focus on the reorganization and/or restitution of the endothelial glycocalyx seem promising, but more research is needed to bring these interventions into medical practice 6