Endothelial damage inhibitor preserves the integrity of venous endothelial cells from patients undergoing coronary bypass surgery.

OBJECTIVES: Despite the success of coronary artery bypass graft (CABG) surgery using autologous saphenous vein grafts (SVGs), nearly 50% of patients experience vein graft disease within 10 years of surgery. One contributing factor to early vein graft disease is endothelial damage during short-term storage of SVGs in inappropriate solutions. Our aim was to evaluate the effects of a novel endothelial damage inhibitor (EDI) on SVGs from patients undergoing elective CABG surgery and on venous endothelial cells (VECs) derived from these SVGs. METHODS: SVGs from 11 patients participating in an ongoing clinical registry (NCT02922088) were included in this study, and incubated with both full electrolyte solution (FES) or EDI for 1 h and then examined histologically. In 8 of 11 patients, VECs were isolated from untreated grafts, incubated with both FES and EDI for 2 h under hypothermic stress conditions and then analysed for activation of an inflammatory phenotype, cell damage and cytotoxicity, as well as endothelial integrity and barrier function. RESULTS: The EDI was superior to FES in protecting the endothelium in SVGs (74 ± 8% versus 56 ± 8%, P < 0.001). Besides confirming that the EDI prevents apoptosis in SVG-derived VECs, we also showed that the EDI temporarily reduces adherens junctions in VECs while protecting focal adhesions compared to FES. CONCLUSIONS: The EDI protects the connectivity and function of the SVG endothelium. Our data suggest that the EDI can preserve focal adhesions in VECs during short-term storage after graft harvesting. This might explain the superiority of the EDI in maintaining most of the endothelium in venous CABG surgery conduits.

CX3CR1 knockout aggravates Coxsackievirus B3-induced myocarditis.

Studies on inflammatory disorders elucidated the pivotal role of the CX3CL1/CX3CR1 axis with respect to the pathophysiology and diseases progression. Coxsackievirus B3 (CVB3)-induced myocarditis is associated with severe cardiac inflammation, which may progress to heart failure. We therefore investigated the influence of CX3CR1 ablation in the model of acute myocarditis, which was induced by inoculation with 5x105 plaque forming units of CVB3 (Nancy strain) in either CX3CR1-/- or C57BL6/j (WT) mice. Seven days after infection, myocardial inflammation, remodeling, and titin expression and phosphorylation were examined by immunohistochemistry, real-time PCR and Pro-Q diamond stain. Cardiac function was assessed by tip catheter. Compared to WT CVB3 mice, CX3CR1-/- CVB3 mice exhibited enhanced left ventricular expression of inflammatory cytokines and chemokines, which was associated with an increase of immune cell infiltration/presence. This shift towards a pro-inflammatory immune response further resulted in increased cardiac fibrosis and cardiomyocyte apoptosis, which was reflected by an impaired cardiac function in CX3CR1-/- CVB3 compared to WT CVB3 mice. These findings demonstrate a cardioprotective role of CX3CR1 in CVB3-infected mice and indicate the relevance of the CX3CL1/CX3CR1 system in CVB3-induced myocarditis.

Left ventricular enlargement in coxsackievirus-B3 induced chronic myocarditis--ongoing inflammation and an imbalance of the matrix degrading system.

Enteroviruses, especially Coxsackie B3 virus (CVB-3), cause acute viral myocarditis, but the detailed mechanisms leading to chronic left ventricular dysfunction and dilatation remain elusive. Myocardial tissues of CVB-3 infected and sham infected male swr/J mice were analyzed after hemodynamic evaluation on days 4, 7, and 28 p.i. by RT-PCR, gelatin zymography, ELISA, immunohistochemistry, sirius red staining, and luxol fast blue staining. In the early phase after infection an abnormal diastolic function was the main hemodynamic finding. CVB-3 infection caused impairment of left ventricular function combined with ventricular dilatation 7 and 28days post-infection. These hemodynamic findings were associated with relevant upregulation of different cytokines (IL-1beta, IL-6, IL-10, INF-gamma, and TNF-alpha) in the acute phase with persistent over-expression of IL-6, IL-10, and INF-gamma in the chronic phase. This virus induced myocardial inflammation was linked to a significant induced MMP/TIMP system (MMP-2,-3,-8, TIMP-1, uPA, tPA-mRNA expression, and MMP-2-activity) in the acute and chronic phase leading to imbalance in the MMP/TIMP-ratio at day 28. This imbalance in the MMP/TIMP system was significantly correlated to the development of ventricular dilatation. Viral persistence induces chronic myocardial inflammation and an imbalance of the matrix degrading system, associated with the development of left ventricular dysfunction and dilatation in chronic murine myocarditis.