Tuning the Thromboinflammatory Response to Venous Flow Interruption by the Ectonucleotidase CD39.

Objective- Leukocyte flux contributes to thrombus formation in deep veins under pathological conditions, but mechanisms that inhibit venous thrombosis are incompletely understood. Ectonucleotide di(tri)phosphohydrolase 1 ( ENTPD1 or Cd39), an ectoenzyme that catabolizes extracellular adenine nucleotides, is embedded on the surface of endothelial cells and leukocytes. We hypothesized that under venous stasis conditions, CD39 regulates inflammation at the vein:blood interface in a murine model of deep vein thrombosis. Approach and Results- CD39-null mice developed significantly larger venous thrombi under venous stasis, with more leukocyte recruitment compared with wild-type mice. Gene expression profiling of wild-type and Cd39-null mice revealed 76 differentially expressed inflammatory genes that were significantly upregulated in Cd39-deleted mice after venous thrombosis, and validation experiments confirmed high expression of several key inflammatory mediators. P-selectin, known to have proximal involvement in venous inflammatory and thrombotic events, was upregulated in Cd39-null mice. Inferior vena caval ligation resulted in thrombosis and a corresponding increase in both P-selectin and VWF (von Willebrand Factor) levels which were strikingly higher in mice lacking the Cd39 gene. These mice also manifest an increase in circulating platelet-leukocyte heteroaggregates suggesting heterotypic crosstalk between coagulation and inflammatory systems, which is amplified in the absence of CD39. Conclusions- These data suggest that CD39 mitigates the venous thromboinflammatory response to flow interruption.

cAMP/CREB-mediated transcriptional regulation of ectonucleoside triphosphate diphosphohydrolase 1 (CD39) expression.

CD39 is a transmembrane enzyme that inhibits platelet reactivity and inflammation by phosphohydrolyzing ATP and ADP to AMP. Cyclic AMP (cAMP), an essential second messenger, is particularly important in regulating genes controlling vascular homeostasis. These experiments test the hypothesis that cAMP might positively regulate the expression of CD39 and thereby modulate important vascular homeostatic properties. Cd39 mRNA was induced by 13.8- fold in RAW cells treated with a membrane-permeant cAMP analogue (8-bromo-cyclic AMP; 8-Br-cAMP), stimulation of adenylate cyclase, or prostanoids known to drive cAMP response. Fluorescence-activated cell sorting, immunofluorescence, and TLC assays demonstrated that both CD39 protein expression and enzymatic activity were increased in cells treated with 8-Br-cAMP but not in cells transfected with short hairpin RNA against CD39. This analogue drove a significant increase in transcriptional activity at the Cd39 promoter although not when the promoter's cAMP-response element sites were mutated. Pretreatment with cAMP-dependent protein kinase (PKA), phosphoinositide 3-kinase (PI3K), or ERK inhibitors nearly obliterated the cAMP-driven increase in Cd39 mRNA, protein expression, and promoter activity. 8-Br-cAMP greatly increased the phosphorylation of CREB1 (Ser(133)) and ATF2 (Thr(71)) in a PKA-, PI3K-, and ERK-dependent fashion. Chromatin immunoprecipitation assays demonstrated that binding of phosphorylated CREB1 and ATF2 to cAMP-response element-like sites was significantly increased with 8-Br-cAMP treatment and that binding was reduced with PKA, PI3K, and ERK inhibition, whereas transfection of Creb1 and Atf2 overexpression constructs enhanced cAMP-driven Cd39 mRNA expression. Transfection of RAW cells with mutated Creb1 (S133A) reduced cAMP-driven Cd39 mRNA expression. Furthermore, the cAMP-mediated induction of Cd39 mRNA, protein, and phosphohydrolytic activity was replicated in primary peritoneal macrophages. These data identify cAMP as a crucial regulator of macrophage CD39 expression and demonstrate that cAMP acts through the PKA/CREB, PKA/PI3K/ATF2, and PKA/ERK/ATF2 pathways to control a key vascular homeostatic mediator.

Efficacy of left atrial plication for atrial functional mitral regurgitation.

OBJECTIVE: Atrial functional mitral regurgitation (AFMR) is caused by atrial fibrillation and left atrial enlargement. Our study aimed to evaluate the efficacy of left atrial plication (LAP) for AFMR. METHODS: Of 1164 mitral valve surgery patients at our hospital from January 2000 to May 2019, 22 patients underwent surgery for AFMR. Our retrospective analysis divided the patients with AFMR into two groups according to whether LAP was performed (LAP + group, n = 9; LAP - group, n = 13). Mitral valve angle (MV angle) (horizontal inclination of mitral valve) was measured by pre- and post-operative computed tomography scan. Individuals with type II mitral regurgitation, left ventricular ejection fraction of < 55%, males with left ventricular endo-diastolic dimension of > 60 mm and females with > 55 mm, aortic valve disease, mitral valve calcification, hypertrophic obstructive cardiomyopathy, and both "redo" and emergency cases were excluded. RESULT: Mitral valve replacement was performed in 6 patients and mitral ring annuloplasty in 16 cases. No recurrence of mitral regurgitation or structural valve deterioration occurred during the follow-up period. There were no hospital deaths; 3 deaths occurred during the follow-up period. Compared to the LAP - group, the LAP + group demonstrated a significantly greater decrease of MV angle (16.6 ± 8.1° vs. 1.2 ± 6.9°, p < 0.01) and left atrial dimension (18.4 ± 7.0 mm vs. 6.9 ± 14.6 mm, p = 0.02). CONCLUSIONS: Surgical results of AFMR were satisfactory. LAP may be appropriate for correcting the angle of a mitral valve tilted horizontally. More cases need to be considered in the future.

Recurrent Pulmonary Embolism Caused by Superficial Femoral Vein Aneurysm.

Venous aneurysms (VA), particularly superficial femoral VAs (SFVAs), are rare vascular lesions. A 65-year-old woman with a history of pulmonary embolism (PE), treated with tissue plasminogen activator and oral anticoagulation, was admitted to hospital for dyspnea. Enhanced computed tomography showed recurrent PE and right SFVA with a mural thrombus. The SFVA was not identified during the first PE. The PE was not massive and was treated with direct oral anticoagulants. The thrombus in the SFVA caused the PE, and surgical repair was performed to prevent further embolic events. Under general anesthesia, the SFVA was excised, and direct anastomosis was performed. PE recurrence, venous aneurysmal changes, and thrombosis were not noted at the 1-year follow-up.

Ectonucleotidase CD39-driven control of postinfarction myocardial repair and rupture.

Mechanical complications of myocardial infarction (MI) are often fatal. Little is known about endogenous factors that predispose to myocardial rupture after MI. Ectonucleoside triphosphate diphosphohydrolase (CD39) could be a critical mediator of propensity to myocardial rupture after MI due to its role in modulating inflammation and thrombosis. Using a model of permanent coronary artery ligation, rupture was virtually abrogated in cd39-/- mice versus cd39+/+ controls, with elevated fibrin and collagen deposition and marked neutrophil and macrophage influx. Macrophages were found to display increased surface expression of CD301 and CD206, marking a reparative phenotype, driven by increased extracellular ATP and IL-4 in the infarcted myocardium of cd39-/- mice. A myeloid-specific CD39-knockout mouse also demonstrated protection from rupture, with an attenuated rupture phenotype, suggesting that complete ablation of CD39 provides the greatest degree of protection in this model. Absence of CD39, either globally or in a myeloid lineage-restricted fashion, skews the phenotype toward alternatively activated (reparative) macrophage infiltration following MI. These studies reveal a previously unrecognized and unexpected role of endogenous CD39 to skew macrophage phenotype and promote a propensity to myocardial rupture after MI.

Strategies for the treatment of aorto-oesophageal fistula.

OBJECTIVES: Presenting a surgical strategy for aorto-oesophageal fistula (AEF). METHODS: From October 1999 to August 2013, 16 patients with AEF were treated at Kobe University Hospital. The mean age was 65.5 ± 10.2 years, and the male/female ratio was 13/3. Eight patients had non-dissecting thoracic aneurysm, 3 had chronic aortic dissection, 5 had oesophageal cancer and 1 had fish bone penetration. Five patients were in shock. Four patients had previous thoracic endovascular aortic repair (TEVAR) in the descending aorta and 1 had hemi-arch replacement. As treatment for AEF, 8 patients underwent TEVAR, 2 had a bridge TEVAR to open surgery, 2 had extra-anatomical bypass (EAB) and 5 had in situ reconstruction of the descending aorta. The oesophagus was resected in 8 patients, and an omental flap was installed in 7 patients. For the 4 most recent cases, simultaneous resection of the aorta and oesophagus, in situ reconstruction of the descending aorta using rifampicin-soaked Dacron graft and omental flap installation were performed. RESULTS: Hospital mortality was noted in 4 patients (25.0%; persistent sepsis n = 3 and pneumonia n = 1). However, since 2007, only 1 of 5 patients died (pneumonia). All patients with oesophageal cancer died during follow-up. Two patients underwent oesophageal reconstruction using a pedicled colon graft and one is on the waiting list for oesophageal reconstruction. CONCLUSIONS: Bridging TEVAR is a useful adjunct in treating AEF patients with shock. One-stage surgery consisting of resection of the aneurysm and oesophagus, in situ reconstruction of the descending aorta and omental flap installation provided a better outcome in the AEF surgical strategy compared with conservative treatment.

Common hepatic artery as an inflow site for off-pump coronary artery bypass grafting.

We used the common hepatic artery (CHA) as an inflow site for a saphenous vein graft bypass to the right coronary system during off-pump coronary artery bypass grafting. The CHA is a suitable inflow vessel to provide sufficient blood flow and a short-distance bypass in case both the ascending aorta and the gastroepiploic artery are considered inadequate.