Targeting of cell-free DNA by DNase I diminishes endothelial dysfunction and inflammation in a rat model of cardiopulmonary bypass

Abstract

The use of cardiopulmonary bypass (CPB) results in the activation of leukocytes, release of neutrophil extracellular traps (NETs) and severe inflammation. We hypothesize that targeting of circulating cell-free DNA (cfDNA) by DNases might represent a feasible therapeutic strategy to limit CPB-associated side effects. Male Wistar rats (n = 24) underwent CPB with deep hypothermic circulatory arrest (DHCA) and were divided into 3 groups: control (group 1), one i.v. bolus DNase I before CPB start (group 2) and a second DNase I dose before reperfusion (group 3). We found a positive correlation between plasma cfDNA/NETs levels and compromised endothelial vasorelaxation after CPB. DNase I administration significantly diminished plasma cfDNA/NETs levels. Further, a dose-dependent improvement in endothelial function accompanied by significant reduction of circulating intercellular adhesion molecule (ICAM)-1 was observed. Rats of group 3 had significantly reduced plasma IL-6 levels and downregulated expression of adhesion molecules resulting in impaired leukocyte extravasation and reduced MPO activity in lungs. Mechanistically, digestion of NETs by DNase I significantly diminished NETs-dependent upregulation of adhesion molecules in human endothelial cells. Altogether, systemic DNase I administration during CPB efficiently reduced cfDNA/NETs-mediated endothelial dysfunction and inflammation and might represent a promising therapeutic strategy for clinical practice.

Identification of Cell-Free DNA Methylation Patterns Unique to the Human Left Ventricle as a Potential Indicator of Acute Cellular Rejection

“…strenuous exercise, fever) 26, 27 and non-physiological stressors (e.g. surgery) 28, 29 it is perhaps not surprising that it was insufficient to detect organ-specific injury.…”

Identification of cell‐free DNA methylation patterns unique to the human left ventricle as a potential indicator of acute cellular rejection

“…The amount of apoptosis occurring outside of focal areas of lymphocyte infiltration was especially variable within individual ACR 1R samples. Given that total cfDNA in the plasma arises from all cells and tissues in the body and can be affected by multiple physiological (e.g., strenuous exercise and fever) 26,27 and non‐physiological stressors (e.g., surgery) 28,29 it is perhaps not surprising that it was insufficient to detect organ‐specific injury.…”

Micro‐RNA gene expressions during cardiopulmonary bypass

“…A tendency to hemolysis is observed during extracorporeal circulation 37 . At the same time, despite the use of heparin, coagulation mechanisms are activated, platelet dysfunctions occur, and many enzymes and cytotoxic products such as myeloperoxidase, hydroxyl radicals, and hydrogen peroxide are secreted from neutrophils, increasing capillary permeability during CPB 38,39 . Therewithal, coronary ischemia and reperfusion impair myocardial microcirculation.…”