Yasunori Matsumoto

Long-term endothelin a receptor blockade inhibits electrical remodeling in cardiomyopathic hamsters.

Background—The endothelin (ET) system is activated in failing hearts. Congestive heart failure frequently is associated with ventricular arrhythmias, which may result from electrical remodeling such as changes of ionic current density and heterogeneous action potential prolongation. We examined the effects of long-term ETA receptor blockade on the electrophysiological properties of ventricular cells, the surface ECG, and the survival in BIO 14.6 cardiomyopathic hamsters. Methods and Results—Membrane currents and action potentials were recorded from left ventricular cells isolated from normal F1&bgr; hamsters and cardiomyopathic BIO 14.6 hamsters untreated and chronically treated with TA-0201, an ETA receptor antagonist. In ventricular cells of untreated BIO 14.6 hamsters, the action potential duration was prolonged and the densities of the L-type Ca2+ current (ICa,L), the transient outward current (Ito), the delayed rectifier K+ current (IK), and the inward rectifier K+ current (IK1) were decreased compared with those of F1&bgr; hamsters. Long-term treatment with the ETA receptor antagonist significantly attenuated action potential duration prolongation and reduction of Ito, IK, and ICa,L in BIO 14.6 ventricular cells. Long-term ETA receptor blockade prevented the QT prolongation and ventricular arrhythmias and improved the survival rate in the cardiomyopathic hamsters. Conclusions—Long-term treatment with an ETA antagonist inhibits electrical remodeling such as downregulation of K+ and Ca2+ currents, action potential prolongation, and the increased QT interval and thereby suppresses ventricular arrhythmias in cardiomyopathic hearts. ETA receptor blockade may provide a new strategy for the prevention of ventricular arrhythmias associated with heart failure.

Myocardial Fibrosis in Fabry Disease Demonstrated by Multislice Computed Tomography Comparison With Biopsy Findings

A54-year-old man presented with dyspnea on effort. Echocardiogram revealed reduced apical wall motion of the left ventricle (LV) with extreme hypertrophy of the interventricular septum (IVS). Conventional coronary angiogram showed normal coronary arteries. Endomyocardialbiopsy specimens obtained from the IVS revealed extensive vacuolization of cardiac myocytes and mild fibrosis on light microscopy, and typical lysosomal inclusions with a concentric lamellar configuration were seen with electron microscopy (Figure 1). With these findings and low plasma -galactosidase activity, he was diagnosed as having Fabry disease. To evaluate the characteristics of the LV, ECG-gated enhanced multislice computed tomography (CT) (Light Speed Ultra, General Electric) was performed with a 1.25-mm slice thickness, helical pitch 3.25. After intravenous injection of 100 mL of iodinated contrast material (350 mgI/mL), CT scanning was performed with retrospective ECG-gated reconstruction at 30 seconds and 8 minutes after injection. In the axial source images, extreme hypertrophy of the IVS and the posterior wall of the LV compared with the apical and lateral walls of the LV could be observed (Figure 2). The apical and lateral portions of the LV revealed lower CT intensity than the IVS in the early phase (arrows), and in the late phase they were abnormally enhanced compared with the IVS, suggesting fibrotic changes in the apical and lateral myocardium. Therefore, we concluded that despite the IVS biopsy results, more fibrotic changes occurred in the apical and lateral portions of the LV rather than in the IVS.A 54-year-old man presented with dyspnea on effort. Echocardiogram revealed reduced apical wall motion of the left ventricle (LV) with extreme hypertrophy of the interventricular septum (IVS). Conventional coronary angiogram showed normal coronary arteries. Endomyocardial-biopsy specimens obtained from the IVS revealed extensive vacuolization of cardiac myocytes and mild fibrosis on light microscopy, and typical lysosomal inclusions with a concentric lamellar configuration were seen with electron micros-copy (Figure 1). With these findings and low plasma α-galactosidase activity, he was diagnosed as having Fabry disease. To evaluate the characteristics of the LV, ECG-gated …

Quantification of plasma exosome is a potential prognostic marker for esophageal squamous cell carcinoma

Exosomes play important roles in cancer progression. Although its contents (e.g., proteins and microRNAs) have been focused on in cancer research, particularly as potential diagnostic markers, the exosome behavior and methods for exosome quantification remain unclear. In the present study, we analyzed the tumor-derived exosome behavior and assessed the quantification of exosomes in patient plasma as a biomarker for esophageal squamous cell carcinoma (ESCC). A CD63-GFP expressing human ESCC cell line (TE2-CD63-GFP) was made by transfection, and mouse subcutaneous tumor models were established. Fluorescence imaging was performed on tumors and plasma exosomes harvested from mice. GFP-positive small vesicles were confirmed in the plasma obtained from TE2-CD63-GFP tumor-bearing mice. Patient plasma was collected in Chiba University Hospital (n=86). Exosomes were extracted from 100 µl of the plasma and quantified by acetylcholinesterase (AChE) activity. The relationship between exosome quantification and the patient clinical characteristics was assessed. The quantification of exosomes isolated from the patient plasma revealed that esophageal cancer patients (n=66) expressed higher exosome levels than non-malignant patients (n=20) (P=0.0002). Although there was no correlation between the tumor progression and the exosome levels, exosome number was the independent prognostic marker and low levels of exosome predicted a poor prognosis (P=0.03). In conclusion, exosome levels may be useful as an independent prognostic factor for ESCC patients.

Images in cardiovascular medicine. Myocardial fibrosis in fabry disease demonstrated by multislice computed tomography: comparison with biopsy findings.

A54-year-old man presented with dyspnea on effort. Echocardiogram revealed reduced apical wall motion of the left ventricle (LV) with extreme hypertrophy of the interventricular septum (IVS). Conventional coronary angiogram showed normal coronary arteries. Endomyocardialbiopsy specimens obtained from the IVS revealed extensive vacuolization of cardiac myocytes and mild fibrosis on light microscopy, and typical lysosomal inclusions with a concentric lamellar configuration were seen with electron microscopy (Figure 1). With these findings and low plasma -galactosidase activity, he was diagnosed as having Fabry disease. To evaluate the characteristics of the LV, ECG-gated enhanced multislice computed tomography (CT) (Light Speed Ultra, General Electric) was performed with a 1.25-mm slice thickness, helical pitch 3.25. After intravenous injection of 100 mL of iodinated contrast material (350 mgI/mL), CT scanning was performed with retrospective ECG-gated reconstruction at 30 seconds and 8 minutes after injection. In the axial source images, extreme hypertrophy of the IVS and the posterior wall of the LV compared with the apical and lateral walls of the LV could be observed (Figure 2). The apical and lateral portions of the LV revealed lower CT intensity than the IVS in the early phase (arrows), and in the late phase they were abnormally enhanced compared with the IVS, suggesting fibrotic changes in the apical and lateral myocardium. Therefore, we concluded that despite the IVS biopsy results, more fibrotic changes occurred in the apical and lateral portions of the LV rather than in the IVS.A 54-year-old man presented with dyspnea on effort. Echocardiogram revealed reduced apical wall motion of the left ventricle (LV) with extreme hypertrophy of the interventricular septum (IVS). Conventional coronary angiogram showed normal coronary arteries. Endomyocardial-biopsy specimens obtained from the IVS revealed extensive vacuolization of cardiac myocytes and mild fibrosis on light microscopy, and typical lysosomal inclusions with a concentric lamellar configuration were seen with electron micros-copy (Figure 1). With these findings and low plasma α-galactosidase activity, he was diagnosed as having Fabry disease. To evaluate the characteristics of the LV, ECG-gated …

Histamine H1-receptor-mediated modulation of the delayed rectifier K+ current in guinea-pig atrial cells: opposite effects on IKs and IKr.

Histamine receptor‐mediated modulation of the rapid and slow components of the delayed rectifier K+ current (IK) was investigated in enzymatically‐dissociated atrial cells of guinea‐pigs using the whole cell configuration of the patch clamp technique. Histamine at a concentration of 10u2003μM enhanced IK recorded during strong depolarization to potentials ranging from +20 to +40u2003mV and inhibited IK recorded during mild depolarization to potentials ranging from −20 to −10u2003mV. The increase of IK was more prominent with longer depolarizing pulses, whereas the inhibition of IK was more marked with shorter depolarizing pulses, suggesting that histamine enhances IKs (the slow component of IK) and inhibits IKr (the rapid component of IK). The histamine‐induced enhancement of IKs and inhibition of IKr were abolished by 3u2003μM chlorpheniramine but not by 10u2003μM cimetidine, suggesting that these opposite effects of histamine on IKr and IKs are mediated by H1‐receptors. In the presence of 5u2003μM E‐4031, an IKr blocker, histamine hardly affected IK during mild depolarization although it enhanced IK during strong depolarization in a concentration‐dependent manner. Histamine increased IKs with EC50 value of 0.7u2003μM. In the presence of 300u2003μM indapamide, an IKs blocker, histamine hardly affected IKs but inhibited IKr in a concentration‐dependent manner. Histamine decreased IKr with IC50 value of 0.3u2003μM. Pretreatment with 100u2003nM calphostin C or 30u2003nM staurosporine, protein kinase C inhibitors, abolished the histamine‐induced enhancement of IKs, but failed to affect the histamine‐induced inhibition of IKr. We conclude that in guinea‐pig atrial cells H1‐receptor stimulation enhances IKs and inhibits IKr through different intracellular mechanisms.

Histone Demethylase LSD1 Inhibitors Prevent Cell Growth by Regulating Gene Expression in Esophageal Squamous Cell Carcinoma Cells.

BackgroundThe expression of genes can be influenced by the balance of histone acetylation and/or histone demethylation, with an imbalance of these processes possibly observed in many cancers. The histone demethylase LSD1 inhibitor activity is associated with selective transcriptional regulation and alterations in the gene expression. However, the exact mechanisms underlying the antitumor effects of LSD1 inhibitors are not fully understood.MethodsThe antitumor effects of NCL1, an LSD1 inhibitor, in esophageal squamous cell cancer (ESCC) cell lines were evaluated. A comprehensive analysis of the changes in the gene expression in ESCC cell lines induced by NCL1 was carried out using a microarray analysis. A loss-of-function assay using a siRNA analysis was performed to examine the oncogenic function of the gene.ResultsNCL1 strongly inhibited the cell growth of T.Tn and TE2 ESCC cells and induced apoptosis. According to the microarray analysis, 81 genes in the T.Tn cells and 149 genes in the TE2 cells were up- or down-regulated 2-fold or more by NCL1 exposure. Among these genes, 27 were contained in both cell lines and exhibited similar expression patterns. PHLDB2, one of the genes down-regulated by NCL1, was overexpressed in the ESCC tumor tissues. Moreover, a high expression level of PHLDB2 was found to be significantly correlated with poor prognosis.ConclusionsThe present observations of the comprehensive analysis of the gene expression levels provide insight into the mechanisms underlying the antitumor effects of LSD1 inhibitors in ESCC patients.

Complications of pulmonary vein isolation by catheter ablation evaluated by ECG-gated multislice computed tomography

As pulmonary vein (PV) isolation by catheter ablation for paroxysmal atrial fibrillation may cause PV luminal stenosis, digital subtraction angiography or magnetic resonance imaging have been used to evaluate the lumen of the PV. Electrocardiogram-gated multislice computed tomography can evaluate the lumen of the PV from any plane desired after acquisition with excellent spatial resolution. It can also evaluate hyperplasia of soft tissue around the lumen of the PV, which cannot be evaluated by digital subtraction angiography, and may thus serve as an indicator of complications or even the effectiveness of this treatment.

The concentration of programmed cell death-ligand 1 in the peripheral blood is a useful biomarker for esophageal squamous cell carcinoma

BackgroundWe determined the serum concentrations of Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) in patients with esophageal squamous cell carcinoma (ESCC).MethodsBlood samples were collected from 85 patients with histologically proved ESCC. Serum levels of PD-1, PD-L1, and PD-L2 were measured using enzyme linked immunosorbent assays. Correlations between serum PD-1, PD-L1, and PD-L2 concentration and tumor depth, number of lymph node metastases, organ metastasis status, or disease stage were assessed and five-year survival rates according to clinicopathological characteristics were calculated.ResultsThe concentration of PD-1 was not differed according to tumor progression. On the other hand, the average concentration of PD-L1 in patients with T3/T4 disease was 15.6 (12.2–18.3) pg/mL (25–75%), and this was significantly higher than that in patients with Tis/T1/T2 disease (pxa0=xa00.020). Similarly, PD-L1 levels were significantly higher in patients with positive lymph nodes than in cases with negative lymph node involvement (pxa0=xa00.006) and were higher in patients with organ metastasis (pxa0=xa00.123) and in more advanced stage (pxa0=xa00.006). Similar tendency was observed regarding PD-L2 concentrations. PD-L2 concentration was higher in T3, T4 cases (pxa0=xa00.008), in LN positive cases (pxa0=xa00.032), and in more advanced stage (pxa0=xa00.024).ConclusionOur data showed that a concentration of PD-L1 in peripheral blood was high in advanced cancer and high concentration of PD-L1 predicted disease progression and also poor survival in patients with ESCC.

Antitumor effects of metformin are a result of inhibiting nuclear factor kappa B nuclear translocation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer that has proven difficult to treat despite multidisciplinary therapy, and a new treatment strategy is demanded. Metformin is used for type 2 diabetes mellitus and its antitumor effects have been reported recently. Metformin exerts antitumor effects in various respects, such as inhibiting inflammation, tumor growth and epithelial‐mesenchymal transition (EMT). However, few reports have described the efficacy of metformin on ESCC, and their findings have been controversial. We analyzed the antitumor effects of metformin and clarified its effects on anti‐inflammation, growth suppression and EMT inhibition. Activation of nuclear factor kappa B (NF‐κB), the major transcription factor induced by inflammation, was investigated by immunostaining. We found that localization of NF‐κB in the nucleus was reduced after metformin treatment. This suggests that metformin inhibited the activation of NF‐κB. Metformin inhibited tumor growth and induced apoptosis in ESCC cell lines. Associated with EMT, we examined cell motility by a wound healing assay and the epithelial marker E‐cadherin expression of various ESCC cell lines by western blotting. Metformin inhibited cell motility and induced E‐cadherin expression. In conclusion, metformin showed multiple antitumor effects such as growth suppression, invasion inhibition, and control of EMT by inhibiting NF‐κB localization on ESCC. Further exploration of the marker of treatment efficacy and combination therapy could result in the possibility for novel treatment to use metformin on ESCC.

Low-dose hyperthermia enhances the antitumor effects of chemotherapy in squamous cell carcinoma

Esophageal squamous cell carcinoma is a highly aggressive neoplasm and the sixth leading cause of global cancer-related death; the 5-year survival rate for esophageal cancer is only about 20%-25% for all stages. Therefore, improving the therapeutic effect is important. This study assessed whether low-dose hyperthermia (LDH) enhances the antitumor effects of chemotherapy. The antitumor effect of chemotherapy with/without LDH in the squamous cell carcinoma cell line SCCVII was evaluated. A comprehensive analysis was performed with real-time polymerase chain reaction (PCR) to study the hyperthermia-induced changes in the gene expression of SCCVII cell lines. In addition, the cytotoxic and apoptotic changes in the cells treated with LDH combined with/without 5-fluorouracil (5-FU) were measured. LDH combined with 5-FU (10 nM) strongly inhibited the cell growth of SCCVII, with flow cytometry showing an increased population of apoptotic cells. PCR showed that LDH promoted a 25.22-fold increase of p53 mRNA and 18.08-fold increase of Bax mRNA in vitro. MDR1 expression was decreased to 28.7% after LDH. This treatment can result in much higher efficacy of antitumor drugs. After LDH, the expressions of TS decreased to 12.06%, OPRT increased by 4.17-fold, and DPD did not change (1.03-fold). This transformations will induce susceptibility to 5-FU. LDH may be a useful enhancer of chemotherapy drugs for squamous cell carcinoma.