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Mitochondrial quality control is critical for cardiac homeostasis as these organelles are responsible for generating most of the energy needed to sustain contraction. Dysfunctional mitochondria are normally degraded via intracellular degradation pathways that converge on the lysosome. Here, we identified an alternative mechanism to eliminate mitochondria when lysosomal function is compromised. We show that lysosomal inhibition leads to increased secretion of mitochondria in large extracellular vesicles (EVs). The EVs are produced in multivesicular bodies, and their release is independent of autophagy. Deletion of the small GTPase Rab7 in cells or adult mouse heart leads to increased secretion of EVs containing ubiquitinated cargos, including intact mitochondria. The secreted EVs are captured by macrophages without activating inflammation. Hearts from aged mice or Danon disease patients have increased levels of secreted EVs containing mitochondria indicating activation of vesicular release during cardiac pathophysiology. Overall, these findings establish that mitochondria are eliminated in large EVs through the endosomal pathway when lysosomal degradation is inhibited. Mitochondrial quality control is critical for cellular homeostasis and survival. Here, the authors identify that defective mitochondria can be eliminated via secretion in large extracellular vesicles when internal lysosomal degradation is compromised.

Deep vein thrombosis (DVT), caused by alterations in venous homeostasis, is the third most common cause of cardiovascular mortality, however, key molecular determinants in venous thrombosis have not been fully elucidated. Several lines of evidence indicate that DVT occurs at the intersection of dysregulated inflammation and coagulation. The enzyme ectonucleoside tri(di)phosphohydrolase (ENTPD1, also known as CD39) is a vascular ecto-apyrase on the surface of leukocytes and the endothelium that inhibits intravascular inflammation and thrombosis by hydrolysis of phosphodiester bonds from nucleotides released by activated cells. Here, we evaluated the contribution of CD39 to venous thrombosis in a restricted-flow model of murine inferior vena cava stenosis. CD39 deficiency conferred a greater than 2-fold increase in venous thrombogenesis, characterized by increased leukocyte engagement, neutrophil extracellular trap formation, fibrin, and local activation of tissue factor in the thrombotic milieu. This venous thrombogenesis was orchestrated by increased phosphorylation of the p65 subunit of NF-kB, activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, and IL-1ß release in CD39-deficient mice. Substantiating these findings, an IL-1ß-neutralizing antibody or the IL-1 receptor inhibitor anakinra attenuated the thrombosis risk in CD39-deficient mice. These data demonstrate that IL-1ß is a key accelerant of venous thrombo-inflammation, which can be suppressed by CD39. CD39 inhibits in vivo crosstalk between inflammation and coagulation pathways and is a critical vascular checkpoint in venous thrombosis.

Deep vein thrombosis (DVT), caused by alterations in venous homeostasis, is the third most common cause of cardiovascular mortality, however, key molecular determinants in venous thrombosis have not been fully elucidated. Several lines of evidence indicate that DVT occurs at the intersection of dysregulated inflammation and coagulation. The enzyme ectonucleoside tri(di)phosphohydrolase (ENTPD1, also known as CD39) is a vascular ecto-apyrase on the surface of leukocytes and the endothelium that inhibits intravascular inflammation and thrombosis by hydrolysis of phosphodiester bonds from nucleotides released by activated cells. Here, we evaluated the contribution of CD39 to venous thrombosis in a restricted-flow model of murine inferior vena cava stenosis. CD39 deficiency conferred a greater than 2-fold increase in venous thrombogenesis, characterized by increased leukocyte engagement, neutrophil extracellular trap formation, fibrin, and local activation of tissue factor in the thrombotic milieu. This venous thrombogenesis was orchestrated by increased phosphorylation of the p65 subunit of NF-[kappa]B, activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, and IL-1[beta] release in CD39-deficient mice. Substantiating these findings, an IL-1[beta]-neutralizing antibody or the IL-1 receptor inhibitor anakinra attenuated the thrombosis risk in CD39- deficient mice. These data demonstrate that IL-1[beta] is a key accelerant of venous thrombo-inflammation, which can be suppressed by CD39. CD39 inhibits in vivo crosstalk between inflammation and coagulation pathways and is a critical vascular checkpoint in venous thrombosis.

Deep vein thrombosis (DVT), caused by alterations in venous homeostasis is the third most common cause of cardiovascular mortality; however, key molecular determinants in venous thrombosis have not been fully elucidated. Several lines of evidence indicate that DVT occurs at the intersection of dysregulated inflammation and coagulation. The enzyme ectonucleoside tri(di)phosphohydrolase (ENTPD1, also known as CD39) is a vascular ecto-apyrase on the surface of leukocytes and the endothelium that inhibits intravascular inflammation and thrombosis by hydrolysis of phosphodiester bonds from nucleotides released by activated cells. Here, we evaluated the contribution of CD39 to venous thrombosis in a restricted-flow model of murine inferior vena cava stenosis. CD39-deficiency conferred a >2-fold increase in venous thrombogenesis, characterized by increased leukocyte engagement, neutrophil extracellular trap formation, fibrin, and local activation of tissue factor in the thrombotic milieu. This was orchestrated by increased phosphorylation of the p65 subunit of NFκB, activation of the NLRP3 inflammasome, and interleukin-1β (IL-1β) release in CD39-deficient mice. Substantiating these findings, an IL-1β-neutralizing antibody attenuated the thrombosis risk in CD39-deficient mice. These data demonstrate that IL-1β is a key accelerant of venous thrombo-inflammation, which can be suppressed by CD39. CD39 inhibits in vivo crosstalk between inflammation and coagulation pathways, and is a critical vascular checkpoint in venous thrombosis.

LB-30057 (CI-1028) is a novel, orally bioavailable, direct thrombin inhibitor with a Ki of 0.38 nM against human thrombin. The effects of LB-30057 on thrombus formation and hemostasis were evaluated in a veno-venous shunt model of thrombosis in rabbits, and compared with inogatran, another direct inhibitor of thrombin. Each compound was studied at 5 or 6 different doses with 5 or 6 rabbits in each group. After administration as a bolus i.v. injection followed by continuous infusion, both LB-30057 and inogatran dose-dependently inhibited thrombus formation, which was measured as an increase in time to occlusion (TTO) and a decrease in thrombus weight. Both compounds also improved vena caval blood flow and reduced the overall incidence of thrombotic occlusion. LB-30057 significantly prolonged TTO from 23 +/- 4 min (before dose) to 110 +/- 10 min at the highest dose (0.7 mg/kg + 47 microg/kg/min) (p < 0.001), and reduced thrombus weight from 57 +/- 2 mg to 15 +/- 5 mg (p < 0.001). Occlusive thrombus formed in only one of six rabbits that received the highest dose of LB-30057 (vs. 13/13 in the control group, p < 0.01). At the dose that produced the maximum antithrombotic effect (0.7 mg/kg + 47 microg/kg/min), LB-30057 increased aPTT and bleeding time approximately 2-and 2.5-fold above baseline, respectively. On a gravimetric basis, LB-30057 and inogatran displayed comparable in vivo antithrombotic efficacy. When compared to equally effective anti thrombotic doses of inogatran, LB-30057 caused less prolongation in aPTT, had no effect on PT, and tended to have less of effect on bleeding time. These results indicate that LB-30057 is an effective antithrombotic compound and it appears to have a better benefit/risk profile than inogatran in this experimental model.

Mitochondrial quality control is critical for cardiac homeostasis as these organelles are responsible for generating most of the energy needed to sustain contraction. Dysfunctional mitochondria are normally degraded via intracellular degradation pathways that converge on the lysosome. Here, we identified an alternative mechanism to eliminate mitochondria when lysosomal function is compromised. We show that lysosomal inhibition leads to increased secretion of mitochondria in large extracellular vesicles (EVs). The EVs are produced in multivesicular bodies, and their release is independent of autophagy. Deletion of the small GTPase Rab7 in cells or adult mouse heart leads to increased secretion of EVs containing ubiquitinated cargos, including intact mitochondria. The secreted EVs are captured by macrophages without activating inflammation. Hearts from aged mice or Danon disease patients have increased levels of secreted EVs containing mitochondria indicating activation of vesicular release during cardiac pathophysiology. Overall, these findings establish that mitochondria are eliminated in large EVs through the endosomal pathway when lysosomal degradation is inhibited.Competing Interest StatementThe authors have declared no competing interest.

The cellular and ionic mechanisms for the initiation and maintenance of life-threatening ventricular arrhythmias during myocardial ischemia are not fully understood. The possible role of ATP-sensitive K$\\sp+$ channels (K scATP) in the genesis of ventricular fibrillation (VF) are examined in both in vivo and in vitro experimental models. Additional studies evaluate the relationship between the K scATP channel and the A sc1 adenosine receptors. A post-infarcted conscious canine model was used to simulate the common clinical condition of sudden cardiac death (SCD) in which acute myocardial ischemia is superimposed on the vulnerable substrate of a previous myocardial infarction. Pinacidil, a selective K scATP channel opener, significantly increased the incidence of SCD (VF occurring during the first hour of acute ischemia). The inducibility of the animals to arrhythmias induced by programmed electrical stimulation (PES) was not altered by the opening of K scATP channels with pinacidil. Pinacidil-induced decreases in refractory periods is thought to be the electrophysiological basis for the profibrillatory effect of K scATP channel activation by facilitating re-entrant excitation. In rabbit isolated hearts, hypoxia reduced tissue ATP content and promoted the opening of K scATP channels, and contributed to the observed shortening of action potential duration (APD) and increased cellular K$\\sp+$ loss. The decreased ATP level accentuated the ability of pinacidil to mediate direct profibrillatory actions. Glibenclamide, a K scATP channel blocker, antagonized pinacidil/hypoxia-induced shortening of APD and ventricular fibrillation. A1 adenosine receptor stimulation was determined to facilitate ventricular fibrillation by decreasing APD and refractoriness in hypoxic/reoxygenated rabbit isolated hearts. These effects was not mediated by the activation of K scATP channels. In summary, pharmacological or pathological activation of K scATP channel appears to promote ventricular fibrillation in ischemic and hypoxic hearts. Despite sharing many features in common with A1 adenosine receptor stimulation, it is not felt that K scATP channel function is regulated by adenosine receptors. Cardiac K scATP channel may play a major role in life threatening arrhythmias in man and should be considered in the search for developing new and effective antifibrillatory drugs.

CI-1031 (ZK-807834) is a novel, synthetic factor Xa (FXa) inhibitor with a Ki of 0.11 nM against human FXa. In human plasma in vitro, CI-1031 doubled PT and aPTT at 0.23 and 0.49 µM, respectively. The in vivo antithrombotic effect of CI-1031 was evaluated in a veno-venous shunt model of thrombosis in anesthetized rabbits. After thrombus formation was verified in the first shunts, rabbits received either vehicle or CI-1031 intravenously (bolus injection of 60, 240, or 480 µg/kg followed by an infusion of 2, 8, or 16 µg/kg/min for 140 min, respectively). The second shunts were inserted after 20 min of infusion of CI-1031 or vehicle. CI-1031 dose-dependently prolonged time to occlusion (TTO) in the second shunts (35 ± 21, 62 ± 24, and 120 ± 0 min for the three dose groups, respectively, vs. 10 ± 1 min for vehicle). Thrombus mass (TM) was reduced in a dose-dependent manner by CI-1031 (42 ± 7, 27 ± 6, and 18 ± 4 mg vs. 50 ± 4 mg for vehicle). Maximal TM reduction was 70% with an IC 50 of 0.6 µg/ml. Among all the coagulation parameters tested, PT had the best correlation with plasma CI- 1031 concentration (r = 0.97). Ex vivo plasma anti-FXa activity was also well correlated with plasma concentration of CI-1031 and with PT (r = 0.96 and 0.98, respectively). These results indicate that CI-1031, which is currently undergoing clinical evaluation, is an effective antithrombotic compound with a favorable efficacy-to-bleeding ratio. In addition, CI-1031 concentration in plasma can be monitored using PT or anti-Xa assays, thereby providing reliable methods to ensure safe and accurate dose titration of CI-1031.

The prevalence of cardiomyopathy is higher in diabetic patients than those without diabetes. Diabetic cardiomyopathy (DCM) is defined as a clinical condition of abnormal myocardial structure and performance in diabetic patients without other cardiac risk factors, such as coronary artery disease, hypertension, and significant valvular disease. Multiple molecular events contribute to the development of DCM, which include the alterations in energy metabolism (fatty acid, glucose, ketone and branched chain amino acids) and the abnormalities of subcellular components in the heart, such as impaired insulin signaling, increased oxidative stress, calcium mishandling and inflammation. There are no specific drugs in treating DCM despite of decades of basic and clinical investigations. This is, in part, due to the lack of our understanding as to how heart failure initiates and develops, especially in diabetic patients without an underlying ischemic cause. Some of the traditional anti-diabetic or lipid-lowering agents aimed at shifting the balance of cardiac metabolism from utilizing fat to glucose have been shown inadequately targeting multiple aspects of the conditions. Peroxisome proliferator-activated receptor α (PPARα), a transcription factor, plays an important role in mediating DCM-related molecular events. Pharmacological targeting of PPARα activation has been demonstrated to be one of the important strategies for patients with diabetes, metabolic syndrome, and atherosclerotic cardiovascular diseases. The aim of this review is to provide a contemporary view of PPARα in association with the underlying pathophysiological changes in DCM. We discuss the PPARα-related drugs in clinical applications and facts related to the drugs that may be considered as risky (such as fenofibrate, bezafibrate, clofibrate) or safe (pemafibrate, metformin and glucagon-like peptide 1-receptor agonists) or having the potential (sodium–glucose co-transporter 2 inhibitor) in treating DCM.

Nuclear energy plays an important role in global energy supply, especially as a key low-carbon source of power. However, safe operation is very critical in nuclear power plants (NPPs). Given the significant impact of human-caused errors on three serious nuclear accidents in history, artificial intelligence (AI) has increasingly been used in assisting operators with regard to making various decisions. In particular, data-driven AI algorithms have been used to identify the presence of accidents and their root causes. However, there is a lack of an open NPP accident dataset for measuring the performance of various algorithms, which is very challenging. This paper presents a first-of-its-kind open dataset created using PCTRAN, a pre-developed and widely used simulator for NPPs. The dataset, namely nuclear power plant accident data (NPPAD), basically covers the common types of accidents in typical pressurised water reactor NPPs, and it contains time-series data on the status or actions of various subsystems, accident types, and severity information. Moreover, the dataset incorporates other simulation data (e.g., radionuclide data) for conducting research beyond accident diagnosis. Measurement(s) nuclear power plant accident data Technology Type(s) nuclear power plant similulation Factor Type(s) accident