Enhancement of Tissue Factor Expression in Monocyte-Derived Dendritic Cells by Pentraxin 3 and Its Modulation by C1 Esterase Inhibitor.

BACKGROUND: We have previously shown that human monocyte-derived dendritic cells (moDCs) may participate in immune system-mediated hypercoagulable state through enhanced tissue factor (TF) expression and that the complement system may be involved in this process. OBJECTIVES: The aim of this study was to explore the role of pentraxin 3 (PTX3) and the complement system in enhanced TF expression in moDCs. METHODS: moDCs were generated from isolated human monocytes. PTX3 levels in whole human blood supplemented with moDCs were determined after lipopolysaccharide (LPS) stimulation. PTX3 release by the generated moDCs upon LPS stimulation was also assessed. The effect of PTX3 on whole blood coagulation was investigated using thromboelastometric analysis. TF expression in stationary moDCs treated with LPS and/or PTX3 was determined by measuring TF activity. The effect of complement inhibitors on TF activity in moDCs treated with LPS and/or PTX3 under low-shear conditions was evaluated. RESULTS: PTX3 levels were higher in whole blood supplemented with moDCs than in the presence of monocytes and were further elevated by LPS stimulation. PTX3 release from generated moDCs was also increased by LPS stimulation. PTX3 reduced whole blood coagulation time in a dose-dependent manner. However, PTX3 did not increase TF expression in stationary moDCs. Under low-shear conditions, PTX3 increased TF expression in moDCs. C1 esterase inhibitor (C1-inh) suppressed this effect. CONCLUSIONS: PTX3 might have a thrombophilic activity and enhance TF expression in moDCs under low-shear conditions. Furthermore, suppression of moDC-associated hypercoagulability by C1-inh might be partly ascribed to its inhibitory effect on PTX3.

Sudden unexpected infantile death due to undiagnosed ventricular septal defect-associated heart failure with single coronary artery.

Ventricular septal defect (VSD) generally has a good prognosis unless complicated by heart failure (HF). We report a case of sudden infant death because of clinically undiagnosed VSD in a seemingly healthy 16-day-old boy. Although a cardiac murmur was auscultated at birth, detailed clinical examination was not performed. Medicolegal autopsy revealed a perimembranous large VSD with a single coronary artery. The infant was diagnosed to have had HF based on the increased weight of the heart and extremely high serum brain natriuretic peptide levels. Histological examination revealed the degeneration of cardiomyocytes. The large VSD was thought to be the major cause of HF, although single coronary artery-associated cardiomyopathy might have also partially contributed to it. The decline in the physiological neonatal pulmonary resistance, which occurs over the first 1 or 2 weeks following birth, led to the acute progression of HF, resulting in circulatory collapse and sudden death. Detailed clinical examination should be performed for neonates with cardiac murmur to prevent avoidable death.

Experimental hypercoagulable state induced by tissue factor expression in monocyte-derived dendritic cells and its modulation by C1 inhibitor.

The crosstalk between immune and coagulation systems plays pivotal roles in host defense, which may involve monocyte-derived dendritic cells (moDCs). Our objectives were to elucidate the role of moDCs in coagulation under inflammatory conditions and the involvement of the complement system. We assessed the effects of lipopolysaccharide (LPS)-stimulated moDCs on coagulation using whole blood thromboelastometry in the presence of complement inhibitors. The sum of clotting time and clot formation time (CT plus CFT) in whole blood thromboelastometry was significantly more reduced in the presence of moDCs than in the absence of monocytes or moDCs and in the presence of monocytes, indicating a more potent coagulability of moDCs. The mRNA expression of coagulation-related proteins in moDCs was analyzed by quantitative PCR, which showed an increase only in the mRNA levels of tissue factor (TF). TF protein expression was assessed by western blot analysis and an activity assay, revealing higher TF expression in moDCs than that in monocytes. The in vitro moDC-associated hypercoagulable state was suppressed by a TF-neutralizing antibody, whereas LPS enhanced the in vitro hypercoagulation further. C1 inhibitor suppressed the in vitro LPS-enhanced whole blood hypercoagulability in the presence of moDCs and the increased TF expression in moDCs. These results suggest a significant role of moDCs and the complement system through TF expression in a hypercoagulable state under inflammatory conditions and demonstrate the suppressive effects of C1 inhibitor on moDC-associated hypercoagulation.

Sudden Death Due to Bilateral Pulmonary Thromboembolism Following Laparoscopic Cholecystectomy.

Cases of sudden death due to pulmonary thromboembolism (PTE) following laparoscopic surgery are very rare. The risk factors for PTE include sex, operation duration, age, obesity, and underlying diseases. The development of thromboprophylaxis according to specific risk factors has contributed to the decrease in postoperative mortality. Here, we describe the case of a 50-year-old patient with sudden death due to PTE at 24 hours after laparoscopic cholecystectomy. The origin of the thrombi were bilateral deep vein thromboses in both the lower extremities. No severe risk factors for PTE were detected in the patient, and pneumatic compression devices were used during the surgery for thromboprophylaxis. We believe that the accumulation of minor risk factors may have contributed to the onset of PTE. Hence, a more cautious assessment of the risk factors for PTE prior to surgery is required in such cases.

[Two autopsy cases in which previous surgery facilitated the positive identification of decomposed bodies]. / Dve pitvy, ve kterých predchozí operace usnadnila ztotoznení posmrtne dekomponovaných tel.

The positive identification of decomposed corpses is often difficult. We describe two autopsy cases in which medical materials, which had been implanted during previous surgical treatments, facilitated positive identification. The discovery of decomposed corpses is increasingly common in Japan, due to the increasing number of lonely deaths. Implanted medical materials and devices may be a useful tool for personal identification in the near future.

[Effect of alcohol on vascular function].

Vascular function is regulated by a balance of vasoconstriction and vasorelaxation. Disorder in this balance due to alcohol consumption causes various clinical conditions. In this review, we discuss the effects of acute and chronic ethanol consumption on vascular responses, including vasoconstriction, endothelium-dependent vasorelaxation, and nerve-mediated vasorelaxation. Acute ethanol administration induces vasoconstriction in ethanol-naive animals in vitro. Furthermore, ethanol can both potentiate and suppress agonist-induced Ca(2+)-dependent vasoconstriction. Moreover, ethanol augments Ca(2+)-independent vasoconstriction by increasing Ca2+ sensitivity. Endothelium-dependent relaxation is mediated by the nitric oxide (NO) pathway and the endothelium-derived hyperpolarizing factor (EDHF) pathway. Acute ethanol treatment inhibits both NO- and EDHF-mediated relaxation. Furthermore, acute ethanol ingestion can also potentiate and suppress calcitonin gene-related peptide (CGRP)-induced nerve-mediated relaxation. These opposing effects may be due to differences in species or vascular beds. Thus, acute ethanol treatment decreases vasorelaxation, thereby shifting the contraction-relaxation balance towards contraction. Combined, these effects are one mechanism by which acute heavy alcohol consumption causes circulatory disturbances such as vasospasms or ischemic heart disease. In contrast, chronic low-dose ethanol has no effect on vasoconstriction, whereas chronic high-dose ethanol increases vasoconstriction. Additionally, chronic ethanol intake has diminished, unchanged, and even increased effects on nerve-mediated relaxation; therefore, conclusions on these effects are not possible at present. Interestingly, chronic low-dose ethanol administration enhanced endothelium-dependent relaxation; however, higher doses inhibited these responses. Therefore, regular or light-to-moderate alcohol intake increases vasorelaxation and may suppress elevated blood pressure, whereas chronic heavy alcohol consumption may raise blood pressure, causing various clinical conditions.

The Inhibitory Effect of Ethanol on Interleukin-1 ß-Induced Suppression of Contractile Response in the Rat Superior Mesenteric Artery.

Interleukin (IL)-1 ß is a cytokine that is upregulated by the pro-inflammatory bacterial endotoxin lipopolysaccharide. This study examined the effect of ethanol on IL-1 ß-mediated suppression of phenylephrine-induced contractility and inducible nitric oxide synthase (iNOS) expression in the rat superior mesenteric artery (SMA). IL-1 ß suppressed the phenylephrine-induced contractile response, and this effect was inhibited by ethanol. The IL-1 ß-mediated effects were also blocked by cycloheximide, an inhibitor of protein synthesis, as well as AMT and 1400W, which are iNOS inhibitors, and PTIO, an NO scavenger. However, indomethacin, a cyclooxygenase (COX) inhibitor that promotes NO-independent vasodilation, did not affect IL-1 ß-mediated suppression of the contractile response. Western blot analysis revealed that iNOS levels in SMA were upregulated by IL-1 ß and inhibited by ethanol (50 and 100 mM). These results indicate that the suppression of the SMA contractile response by IL-1 ß requires iNOS activity, but not COX-2. Furthermore, these data suggest that ethanol inhibits the effects of IL-1 ß on the contractile response via inhibition of iNOS, rather than COX-2.

An autopsy case of a young man with a single overdose of dextromethorphan.

Dextromethorphan (DXM) is an over-the-counter antitussive that is commonly used worldwide. Recently, DXM has become popular among young individuals because of its euphoric, hallucinogenic, and dissociative properties. Despite an increasing number of patients with DXM addiction, fatal cases of DXM poisoning are rare, and patients with fatalities often ingest DXM along with other drugs. Here, we report an autopsy case in which DXM was detected without multidrug ingestion. A man in his early twenties was found dead at home; no external injuries or obvious internal lesions were found during the autopsy. The toxicological analyses revealed extremely high concentrations of DXM, and no drugs other than DXM were detected. To the best of our knowledge, this is the first case report to describe a death caused by a single overdose of DXM in Japan. Public awareness regarding the risks associated with a massive ingestion of DXM should be increased.

Suppression of arterial thrombosis without affecting hemostatic parameters with a cell-penetrating PAR1 pepducin.

BACKGROUND: Thrombin-dependent platelet activation is heightened in the setting of percutaneous coronary intervention and may cause arterial thrombosis with consequent myocardial necrosis. Given the high incidence of adverse effects in patients with acute coronary syndromes, there remains an unmet need for the development of new therapeutics that target platelet activation without unduly affecting hemostasis. The thrombin receptor, PAR1, has recently emerged as a promising new target for therapeutic intervention in patients with acute coronary syndromes. METHODS AND RESULTS: We report the development of a first-in-class intracellular PAR1 inhibitor with optimized pharmacokinetic properties for use during percutaneous coronary intervention in patients with acute coronary syndromes. PZ-128 is a cell-penetrating pepducin inhibitor of PAR1 that targets the receptor-G-protein interface on the inside surface of platelets. The structure of PZ-128 closely resembles the predicted off-state of the corresponding juxtamembrane region of the third intracellular loop of PAR1. The onset of action of PZ-128 was rapid and suppressed PAR1 aggregation and arterial thrombosis in guinea pigs and baboons and strongly synergized with oral clopidogrel. There was full recovery of platelet function by 24 hours. Importantly, PZ-128 had no effect on bleeding or coagulation parameters in primates or in blood from patients undergoing percutaneous coronary intervention. CONCLUSIONS: Based on the efficacy data in nonhuman primates with no noted adverse effects on hemostasis, we anticipate that the rapid onset of platelet inhibition and reversible properties of PZ-128 are well suited to the acute interventional setting of percutaneous coronary intervention and may provide an alternative to long-acting small-molecule inhibitors of PAR1.

Involvement of monocyte-derived extracellular vesicle-associated tissue factor activity in convallatoxin-induced hypercoagulability.

OBJECTIVES: Convallatoxin (CNT) is a natural cardiac glycoside extracted from lily of the valley ( Convallaria majalis ). Although it is empirically known to cause blood coagulation disorders, the underlying mechanism remains unclear. CNT exerts cytotoxicity and increases tissue factor (TF) expression in endothelial cells. However, the direct action of CNT on blood coagulation remains unclear. Therefore, herein, we investigated the effects of CNT on whole blood coagulation system and TF expression in monocytes. METHODS: Blood samples were collected from healthy volunteers to measure plasma thrombin-antithrombin complex (TAT) concentration using ELISA and to perform rotational thromboelastometry (ROTEM) and whole-blood extracellular vesicle (EV)-associated TF (EV-TF) analysis. The effects of CNT were also investigated using the monocytic human cell line THP-1. Quantitative real-time PCR and western blotting were performed, and PD98059, a mitogen-activated protein kinase (MAPK) inhibitor, was used to elucidate the action mechanism of CNT-mediated TF production. RESULTS: CNT treatment increased EV-TF activity, shortened the whole blood clotting time in rotational thromboelastometry analysis, and increased TAT levels, which is an index of thrombin generation. Furthermore, CNT increased TF mRNA expression in THP-1 cells and EV-TF activity in the cell culture supernatant. Therefore, CNT may induce a hypercoagulable state with thrombin generation, in which elevated EV-TF activity derived from monocytes might be involved. These procoagulant effects of CNT were reversed by PD98059, suggesting that CNT-induced TF production in monocytes might be mediated by the MAPK pathway. CONCLUSIONS: The findings of the present study have further clarified the procoagulant properties of CNT.

Protease-activated receptor-2 modulates protease-activated receptor-1-driven neointimal hyperplasia.

OBJECTIVE: Emerging evidence suggests that protease-activated receptors-1 and -2 (PAR1 and PAR2) can signal together in response to proteases found in the rapidly changing microenvironment of damaged blood vessels. However, it is unknown whether PAR1 and PAR2 promote or mitigate the hyperplastic response to arterial injury. Using cell-penetrating PAR1 pepducins and mice deficient in PAR1 or PAR2, we set out to determine the respective contributions of the receptors to hyperplasia and phenotypic modulation of smooth muscle cells (SMCs) in response to arterial injury. METHODS AND RESULTS: SMCs were strongly activated by PAR1 stimulation, as evidenced by increased mitogenesis, mitochondrial activity, and calcium mobilization. The effects of chronic PAR1 stimulation following vascular injury were studied by performing carotid artery ligations in mice treated with the PAR1 agonist pepducin, P1pal-13. Histological analysis revealed that PAR1 stimulation caused striking hyperplasia, which was ablated in PAR1(-/-) and, surprisingly, PAR2(-/-) mice. P1pal-13 treatment yielded an expression pattern consistent with a dedifferentiated phenotype in carotid artery SMCs. Detection of PAR1-PAR2 complexes provided an explanation for the hyperplastic effects of the PAR1 agonist requiring the presence of both receptors. CONCLUSIONS: We conclude that PAR2 regulates the PAR1 hyperplastic response to arterial injury leading to stenosis.

The homeobox gene Hex regulates hepatocyte differentiation from embryonic stem cell-derived endoderm.

We investigated the role of the hematopoietically expressed homeobox (Hex) in the differentiation and development of hepatocytes within embryonic stem cell (ESC)-derived embryoid bodies (EBs). Analyses of hepatic endoderm derived from Hex(-/-) EBs revealed a dramatic reduction in the levels of albumin (Alb) and alpha-fetoprotein (Afp) expression. In contrast, stage-specific forced expression of Hex in EBs from wild-type ESCs led to the up-regulation of Alb and Afp expression and secretion of Alb and transferrin. These inductive effects were restricted to c-kit(+) endoderm-enriched EB-derived populations, suggesting that Hex functions at the level of hepatic specification of endoderm in this model. Microarray analysis revealed that Hex regulated the expression of a broad spectrum of hepatocyte-related genes, including fibrinogens, apolipoproteins, and cytochromes. When added to the endoderm-induced EBs, bone morphogenetic protein 4 acted synergistically with Hex in the induction of expression of Alb, Afp, carbamoyl phosphate synthetase, transcription factor 1, and CCAAT/enhancer binding protein alpha. These findings indicate that Hex plays a pivotal role during induction of liver development from endoderm in this in vitro model and suggest that this strategy may provide important insight into the generation of functional hepatocytes from ESCs.

Endothelium-Independent Relaxation of Vascular Smooth Muscle Induced by Persimmon-Derived Polyphenol Phytocomplex in Rats.

The vasorelaxant effect of polyphenols is well known, and the mortality rate due to coronary artery disease is low in people who consume polyphenol-containing foods. We aimed to elucidate the mechanism by which polyphenols derived from persimmon juice (PJ) and persimmon leaves (PLs) induce vasorelaxation and suppress vasocontraction in the superior mesenteric arteries isolated from male Sprague Dawley rats. Vasocontraction was induced with 1 µM phenylephrine, and polyphenol-induced vasorelaxation was expressed as a percentage of the previous tone induced by phenylephrine. PJ powder (100 mg/L) induced higher levels of vasorelaxation (mean ± standard error of the mean, 88.6% ± 4.4%) than PLs powder (1 g/L; 72.0% ± 10.8%). Nitric oxide pathway inhibitors (NG-nitro-L-arginine methyl ester + carboxy-PTIO) did not affect persimmon-derived polyphenol-induced vasorelaxation, whereas potassium chloride, tetraethylammonium, and potassium-channel inhibitors did. Vasorelaxation was endothelium independent with both extracts. Phenylephrine-induced vasocontraction was suppressed by pretreatment with PJ and PLs powder, even when inositol triphosphate-mediated Ca2+ release and extracellular Ca2+ influx were inhibited. These results suggest that persimmon-derived polyphenol phytocomplex cause vasorelaxation and inhibit vasocontraction through hyperpolarization of smooth muscle cells. Persimmon-derived polyphenols may be able to prevent cardiovascular diseases caused by abnormal contraction of blood vessels.

Convallatoxin, the primary cardiac glycoside in lily of the valley (Convallaria majalis), induces tissue factor expression in endothelial cells.

BACKGROUND: Convallotoxin (CNT), present in lily of the valley (Convallaria majalis), is a toxin that causes food poisoning among humans and companion animals. Although various symptoms of CNT poisoning have been well described, hypercoagulability owing to CNT is only empirically known among some veterinarians, and the underlying mechanism remains to be elucidated. CNT exerts cytotoxic effects on endothelial cells. OBJECTIVES: This study aimed to determine whether CNT induces the expression of tissue factor (TF), a potent initiator of the extrinsic coagulation cascade, in endothelial cells and leads to a hypercoagulable state. METHODS: Human umbilical vein endothelial cells (HUVECs) were used for in vitro experiments. HUVECs were treated with or without CNT (50 and 100 nM) for 4 h. Phosphate-buffered saline was used as a control. Cell viability was determined using the WST-8 assay. Quantitative real-time polymerase chain reaction was performed to determine TF mRNA expression. TF protein expression was observed using a laser scanning confocal microscope. RESULTS: The viability of HUVECs significantly reduced after CNT treatment compared with that of non-treated cells (p < 0.05). Moreover, a significant increase in TF mRNA and protein expression was observed after 4 h of CNT treatment. CNT elicited these effects in a dose-dependent manner. CONCLUSIONS: TF expression induced by CNT in endothelial cells can contribute to the development of a hypercoagulable state. The present study partially revealed the mechanisms underlying the CNT-induced hypercoagulable state. The findings can contribute to the development of a novel therapy for lily of the valley poisoning.

Cardiac sudden death in a young cannabis user.

We report a case of sudden death due to acute coronary syndrome (ACS) in a young cannabis user. A man in his late thirties died at home, and marijuana was found. The autopsy revealed severe occlusion by an atherosclerotic plaque in the left anterior descending artery. The histopathological examination revealed ischemic changes, likely caused by cannabis-induced sympathetic ß-adrenergic stimulation. Both cannabinoid receptors (CB1 and CB2) were expressed in the atherosclerotic lesions. The CB2 expression was higher than CB1 expression in the atherosclerotic plaque, corresponding to macrophage infiltration. Since cannabis is regarded as a casual drug due to its lower levels of dependency, some individuals have supported legalized marijuana use. However, this case report will provide cautions on the casual use of cannabis.

Generation of functional gut-like organ from mouse induced pluripotent stem cells.

Induced pluripotent stem (iPS) cells have the pluripotency to differentiate into broad spectrum derivatives of all three embryonic germ layers. However, the in vitro organ differentiation potential of iPS cells to organize a complex and functional "organ" has not yet been demonstrated. Here, we demonstrate that mouse iPS cells have the ability to organize a gut-like organ with motor function in vitro by a hanging drop culture system. This "induced gut (iGut)" exhibited spontaneous contraction and highly coordinated peristalsis accompanied by a transportation of contents. Ultrastructural analysis identified that the iGut had large lumens surrounded by three distinct layers (epithelium, connective tissue and musculature). Immunoreactivity for c-Kit, a marker of interstitial cells of Cajal (ICCs, enteric pacemaker cells), was observed in the wall of the lumen and formed a distinct and dense network. The neurofilament immunoreactivity was identified to form large ganglion-like structures and dense neuronal networks. The iGut was composed of all the enteric components of three germ layers: epithelial cells (endoderm), smooth muscle cells (mesoderm), ICCs (mesoderm), and enteric neurons (ectoderm). This is the first report to demonstrate the in vitro differentiation potential of iPS cells into particular types of functional "organs." This work not only contributes to understanding the mechanisms of incurable gut disease through disease-specific iPS cells, but also facilitates the clinical application of patient-specific iPS cells for novel therapeutic strategies such as patient-specific "organ" regenerative medicine in the future.

Effects of dopamine antagonists on methamphetamine-induced dopamine release in high and low alcohol preference rats.

The authors have previously shown that high alcohol preference rats (HAP) have a significantly higher sensitivity than low alcohol preference rats (LAP) for methamphetamine (MAP). In this study, changes in dopamine and serotonin release induced by MAP (1 mg/kg, intraperitoneally) after pre-treatment with D1 and D2 receptor antagonists were examined in the striatum of rats with different alcohol preferences to elucidate differences in receptor levels between the two rat strains. D1 receptor antagonist SCH23390 or D2 receptor antagonist haloperidol were administrated intracerebroventricularly 10 min before MAP stimulation. This study investigated the effect of methamphetamine-induced dopamine and serotonin release in striatum using microdialysis of freely moving rats coupled to ECD-HPLC. With haloperidol treatment both strains of rats showed a significantly greater maximum increase on MAP-induced dopamine release compared with respective control rats. However, after SCH23390 treatment only HAP rats showed a significantly greater increase in dopamine release compared with controls. SCH23390 blocks mainly D1 receptors only in the post-synaptic membrane, whereas haloperidol blocks D2 receptors in both the pre-synaptic and post-synaptic membranes. The MAP-induced increase in dopamine release following haloperidol pre-treatment was greater than SCH23390 pre-treatment in both strains. This result indicates that D2 receptors (autoreceptors) in the pre-synaptic membrane were blocked, leading to the elimination of the feedback function that regulates dopamine release. These data suggested that alcohol preference is associated with the action of MAP, and the dopaminergic mechanism, specifically the D1 system in the striatum, might have a different pathway dependent on alcohol preference.

Enhancement effect of ethanol on lipopolysaccharide-induced procoagulant status in human umbilical endothelial cells.

In spite of the inhibitory effects of ethanol (EtOH) on platelet function, soft blood clots are often observed in cadaveric blood in cases of sudden death after alcohol ingestion. In order to resolve this discrepancy, we have focused on the role of vascular endothelial cells. We tried to investigate the effects of EtOH and LPS on endothelial cells from various perspectives; thrombogenic factor (Von Willebrand factor, VWF), fibrinolytic factor (tissue plasminogen activator, tPA) and inflammatory factor (Interleukin-6, IL-6). Human umbilical vein endothelial cells (HUVECs) were incubated with various concentrations of EtOH (0-160 mM) with or without LPS. Treatment with EtOH and LPS increased VWF release from HUVECs without enhancement mRNA expression. Treatment with 40 mM of EtOH also increased IL-6 release from HUVECs without enhancement mRNA expression. Although EtOH inhibited LPS-induced IL-6 mRNA expression, 20 mM of EtOH still had an increasing effect on the release of IL-6. These doses of EtOH are consistent with a moderate drunkenness level in a normal person. On the other hand, mRNA expression and release reaction of tPA were not affected by EtOH and LPS addition. In conclusion, EtOH enhances procoagulant status via VWF release and IL-6 production cooperation with LPS and may contribute to soft blood clot formation in cadaveric blood.