Cross talk between endothelial and red blood cell glycocalyces via near-field flow

Abstract

Vascular endothelial cells and circulating red blood cell (RBC) surfaces are both covered by a layer of bushy glycocalyx. The interplay between these glycocalyx layers is hardly measurable and insufficiently understood. This study aims to investigate and qualify the possible interactions between the glycocalyces of RBCs and endothelial cells using mathematical modeling and numerical simulation. Dissipative particle dynamics (DPD) simulations are conducted to investigate the response of the endothelial glycocalyx (EG) to varying ambient conditions. A two-compartment model including EG and flow and a threecompartment model comprising EG, RBC glycocalyx, and flow are established. The two-compartment analysis shows that a relatively fast flow is associated with a predominantly bending motion of the EG, whereas oscillatory motions are predominant in a relatively slow flow. Results show that circulating RBCs cause the contactless deformation of EG. Its deformation is dependent on the chain layout, chain length, bending stiffness, RBC-to-EG distance, and RBC velocities. Specifically, shorter EG chains or RBC-to-EG distance leads to greater relative deflections of EG. Deformation of EG is enhanced when the EG chains are rarefied or RBCs move faster. The bending stiffness maintains stretching conformation of EG. Moreover, a compact EG chain layout and shedding EG chains disturb the neighboring flow field, causing disordered flow velocity distributions. In contrast, the movement of EG chains on RBC surfaces exerts a marginal driving force on RBCs. The DPD method is used for the first time, to our knowledge, in the three-compartment system to explore the cross talk between EG and RBC glycocalyx. This study suggests that RBCs drive the EG deformation via the near-field flow, whereas marginal propulsion of RBCs by the EG is observed. These new, to our knowledge, findings provide a new angle to understand the roles of glycocalyx in mechanotransduction and microvascular permeability and their perturbations under idealized pathophysiologic conditions associated with EG degradation.

Understanding the Role of Endothelial Glycocalyx in Mechanotransduction via Computational Simulation: A Mini Review

“…As a simple extension, one may expect that the shedding or impairment of EG chains would change flow patterns, cause flow instability and further disturb mechanotransduction. The role of EG in regulating flow field was also demonstrated in a recent DPD study (Jiang et al, 2021).…”

“…Beyond the fluid-structure interactions between the blood flow and EG layer, mesoscopic methods have been applied to a wide spectrum of haemodynamic problems, like cell suspension and leukocyte adhesion over endothelium (Yan et al, 2019), the glycocalyx-endothelium-erythrocyte interaction in the microcirculation (Pontrelli et al, 2015;Jiang et al, 2021) and the formation of the cell-free layer (Deng et al, 2012).…”

Ways and Means of Cellular Reconditioning for Kidney Regeneration

“…This insight, probably pertaining to other syndecans as well, is at the core of pathobiology of endothelial glycocalyx degradation. In our modeling studies taking into account diverse patterns of HS degradation on endothelial cells under flow interacting with erythrocytes, Jiang et al [31] showed reduction of flow-induced motility of remnant chains, defective repelling force against flowing erythrocytes adhesion to the surface of endothelial glycocalyx, and reduction of rotational movements of red blood cells.…”

Biomechanical properties of endothelial glycocalyx: An imperfect pendulum

“…1 Oscillation of GAG chains at varying GAG geometries (modified from Ref. [9] with permission.) In contrast to the classical unhindered pendulum oscillations, in the case of glycocalyx motility is modified by the length and density of heparan sulfate chains, as well as the same parameters of the core protein, e.g., syndecans.…”