Determination of physiological cardiac myosin-binging protein levels (cMyc) in healthy populations

Background

Cardiac myosin–binding protein C (cMyC) is a cardiac-restricted protein that has more abundant, rapid release and clearance kinetics than cardiac troponin. The current ESC guideline suggests the cMyC may provide value as an alternative to cardiac troponin. The 99th percentile value is universally endorsed as the reference cut off to aid in the diagnosis of acute myocardial infarction (AMI), however, none of the report of healthy population of cMyC.

Purpose

The aim of this study was to evaluate the distribution of cMyC values in healthy subjects.

Methods

We used two cohorts in this retrospective study. 1) Healthy subjects; a total of 500 subjects (250 men and 250 women) who had annual health examinations in 2012 in the area of Kamigoto, a suburb of Nagasaki city in Southern Japan were enrolled. All participants showed none of abnormal findings including cell blood counts, chemical analysis, liver function tests, general urine tests, occult blood tests of stool, barium swallow, mammography for women, abdominal ultrasound sonography, and electrocardiogram. All blood samples were obtained in a fasting state in the morning. 2) Chest pain subjects; we collected samples from 250 subjects including 50 with non-ST elevation myocardial infarction visited admitted to a university hospital for measurement of high-sensitivity troponin T and coronary artery assessment by coronary angiography. We measured cMyC level in both cohorts by HISCL™-800 system (Sysmex corporation, Japan). The assay has a limit of detection of 0.5 ng/L and a lower limit of quantification of 1.3 ng/L.

Result

In healthy subjects, median age (IQR) was 44 (20, 82) in men and 50 (23, 91) in women. The 99th percentile of cMyC was 27.3 ng/L, which was around one-third lower than that in previous report (87 ng/L). In chest pain subjects, the concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 66 ng/L versus 10 ng/L, P<0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.85 (95% CI 0.79–0.91) and hs-cTnT (AUC, 0.81 (95% CI 0.76–0.88)).

Conclusion

We defined the normal range of cMyC in healthy Japanese subjects. The level of cMyC at presentation provides discriminatory power comparable to hs-cTnT in the diagnosis of AMI. To determine the physiological value of a biomarker may be necessary to evaluate enough information about their health status.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research

One-year outcome of the rule-out group according to the 0-h /1-hour algorithm with suspected myocardial infarction in Asian countries

 

Background/Introduction; A rapid rule-out or rule-in protocol based on the 0-h/1-hour algorithm using high-sensitivity cardiac troponin T (hs-cTnT) is recommended by the European Society of Cardiology (ESC). Around 40–50% were stratified into “rule-out” group, and their 30-days prognosis was excellent. However, the one-year prognosis is uncertain. We aimed to better characterize these patients.

Methods

This study was a prospective, multi-center, observational study of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS) admitted to 5 hospitals in Japan and Taiwan from 2014 November to 2018 December, respectively.

All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, standard blood test, chest radiography. Exclusion criteria were ST elevated myocardial infarction, chronic kidney disease (serum creatinine more than 3 mg/dL) and congestive heart failure, arrhythmia, or infection disease. The patients were divided into three groups according to the algorithm; “rule-out”, “observe” and “rule-in”. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, coronary computed tomography, stress electrocardiography and follow-up data. The presence of acute myocardial infarction (AMI) was defined according to the Fourth Universal Definition of Myocardial Infarction. After hospital discharge patients were follow after one-year b telephone or in written form. Major adverse cardiovascular events (including death myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention (PCI)) were recorded by establishing contact with the patient and the family physicians. The primary prognosis end point was all-cause mortality.

Results

Of the 1,187 patients were analyzed after exclusion. The prevalence rate of AMI was 16.1%. According to the algorithm, 42% (n=493) of patients were assigned to “rule-out” group and had no AMI nor death. The most common final adjudicated diagnoses were atypical chest pain (80%), gallstone attack (3%) and vasospastic angina pectoris (2%). All patients with unstable angina (4.7%) underwent PCI.

Conclusion(s)

Our findings suggest that the “rule-out” group patients according to ESC 0-h/1-hour algorithm provides very high safety and efficacy for the triage toward AMI.

Funding Acknowledgement

Type of funding source: None

Effects of continuous exposure to low concentration of ClO2 gas on the growth, viability, and maintenance of undifferentiated MSCs in long-term cultures

Introduction

Hygienic management is more important in the manufacturing of cell products than in the production of chemical agents, because cell material and final product cannot be decontaminated. On the other hand, especially in the selection of hygienic agent, the adverse effects on the cells must be considered as well as the decontamination effect. ClO₂ is a potent disinfectant, which is now expected as a safe and effective hygienic agent in the field of cell production. In this study, we investigated the effects of low dose ClO₂ gas in the atmosphere of CO₂ incubator on the characteristics of MSCs cultured in it.

Methods

First, we installed a ClO₂ generator to a CO₂ incubator for cell culture in which a constant level of ClO₂ can be maintained. After culturing human cord derived MSCs in the CO₂ incubator, the characteristics of cells were analyzed.

Results

Continuous exposure to 0.05 ppmv of ClO₂ gas did not affect cell proliferation until at least 8th passage. In the FACS analysis, antigens usually expressed on MSCs, CD105, CD90, CD44, CD73 and CD29, were positively observed, but differentiation markers, CD11b and CD34, were little expressed on the MSCs exposed to 0.05 ppmv or 0.1 ppmv of ClO₂ gas just as on the control cells. Also in the investigation for cell death, 0.05 ppmv and 0.1 ppmv of ClO₂ gas little affected the viability, apoptosis or necrosis of MSCs. Furthermore, we assessed senescence using SA-β-gal staining. Although the frequency of stained cells cultured in 0.1 ppmv of ClO₂ gas was significantly increased than that of not exposed cells, the stained cells in 0.05 ppmv were rare and their frequency was almost the same as that in control.

Conclusions

All these results indicate that, although excessive concentration of ClO₂ gas induces senescence but neither apoptosis nor cell differentiation, exposure to 0.05 ppmv of ClO₂ gas little affected the characteristics of MSCs. In this study we demonstrate that continuous exposure to appropriate dose of ClO₂ gas can be safely used as decontamination agent in cell processing facilities.

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Continuous exposure to low concentration of ClO₂ gas little affected to of MSCs.

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Higher concentration of ClO₂ gas induced senescence to MSCs.

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The most suitable concentration for the continuous of ClO₂ gas exposure during the culture of MSCs was identified.

P2677A combination of HEART score and a 0-hour/1-hour algorithm for early and safe triage tool for patients in observe zone

Background

The European Society Cardiology guidelines recommend that a 0-hour/1-hour (0–1hr) algorithm using high sensitivity cardiac troponin T (hs-cTnT) improves the early triage of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS). However, diagnostic uncertainty remains in the 25–30% of patients assigned to “observe” group.

Purpose

To establish a step wise risk score system using HEART score and 0-hour/1-hour algorithm to identify the low risk group from observation group.

Methods

This study was a prospective, multi-center, observational study of patients with suspected NSTE-ACS admitted to five hospitals in Japan and Taiwan from 2014 to 2018, respectively. We applied the algorithm and calculated HEART score simultaneously. Patients were divided into three groups according to the algorithm: hs-cTnT below 12 ng/L and delta 1 hour below 3 ng/L were the “rule out” group; hs-cTnT at least 52 ng/L or delta 1 hour at least 5 ng/L were in the “rule in” group; the remaining patients were classified as the “observe” group. All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, continuous ECG monitoring, pulse oximetry, standard blood test, chest radiography, cardiac and abdominal ultrasonography. Patients presenting with congestive heart failure, terminal kidney disease on hemodialysis state, arrhythmia, or infection disease (which causes to increase troponin level) were excluded. Thirty-day MACE was defined as acute myocardial infarction, unstable angina (UA), or death.

Results

Of the 1,332 patients enrolled, 933 patients were analyzed after exclusion. NSTE-ACS was the final diagnosis for 122 (13.1%) patients and none of death. The HEART score less than 4 points in observation groups identified as very low risk with a negative predictive value (NPV) of 98.1% (95% confidential interval (CI); 90.1%-100%) and sensitivity of 98.0% (95% CI; 89.6%-100%). There were only one patient (0.5%) with AMI. In case of the HEART score less than 5 points, it could also identify as very low risk with a NPV of 96.7% (95% CI; 90.8%-99.3%%) and sensitivity of 94.1% (95% CI; 83.8%-98.8%). There were only three patients (1.2%) with AMI.

Conclusion

A combination of HEART score and the 0-hour/1-hour algorithm strategy rapidly identified the patient in observation group of 30-day MACE including UA where nor further cardiac testing would be needed.

Acknowledgement/Funding

JSPS KAKENHI Grant Number JP18K09554

P2676Prospective validation of the 2015 ESC 0-hour/1-hour algorithm using high-sensitivity cardiac troponin T in Asian countries

Background/Introduction

Implementation of the 2015 ESC 0-hour/1-hour algorithm using high-sensitivity troponin (hs-cTn) T in Asian countries presents a challenge for clinical practice.

Purpose

We aimed to prospectively validate the 0-hour/1-hour algorithm in Asian countries.

Methods

We conducted a prospective, multi-center, international cohort already utilizing 0-hour/1-hour algorithm using hs-cTnT for evaluation of patients with suspected of non-ST elevation acute coronary syndrome (NSTE-ACS). All patients underwent a clinical assessment the included medical history, physical examination, 12-lead ECG, continuous ECG monitoring, pulse oximetry, standard blood test, chest radiography, cardiac and abdominal ultrasonography. Patients presenting with congestive heart failure, terminal kidney disease on hemodialysis state, arrhythmia, or infection disease (which cause to increase troponin level) were excluded. Patients were divided into three groups according to the algorithm: hs-cTnT below 12 ng/L and delta 1 hour below 3 ng/L were the “rule out” group; hs-cTnT at least 52 ng/L or delta 1 hour at least 5 ng/L were in the “rule in” group; the remaining patients were classified as the “observational” group. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, coronary computed tomography, stress electrocardiography and follow-up data. The presence of acute myocardial infarction (AMI) was defined according to the Fourth Universal Definition of Myocardial Infarction.

Results

Of the 1,332 patients enrolled in 2014 to 2018, 933 patients were analyzed after exclusion. AMI was the final diagnosis for 122 (13.1%) patients. The algorithm ruled out AMI in 401 patients with a negative predictive value and sensitivity of 100% (95% confidential interval [CI], 98.6%-100%) and 100% (95% CI, 94.0%-100%), respectively, in the rule-out group. None of the patients were diagnosed with AMI. Among the 211 patients classified into the rule-in group, 90 were diagnosed as having AMI. The positive predictive value and specificity were 43.1% (95% CI, 36.2%-50.2%) and 78.3% (95% CI, 74.5%-81.7%), respectively. The median length of hospital stay was 159 min (142–180) in rule out group.

Conclusion(s)

Our findings suggest that the 0-hour/1-hour algorithm using hs-cTnT provides very high safety and efficacy for the triage toward rapid rule-out to rule-in of AMI.

Acknowledgement/Funding

JSPS KAKENHI Grant Number JP18K09554

Prostacyclin Analogue-Loaded Nanoparticles Attenuate Myocardial Ischemia/Reperfusion Injury in Rats

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Intravenously injected ONO-1301–containing nanoparticles selectively accumulated in the ischemic border area of the myocardium.

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Prominent up-regulation occurred of proangiogenic cytokines such as vascular endothelial growth factor and angiopoietin-1 in the ischemic myocardium, which may have contributed to the preservation of the native vascular and capillary networks, thus preserving regional myocardial blood flow.

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Down-regulation of the proinflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α in the ischemic myocardium might have led to the attenuation of myocyte swelling and the suppression of the endothelial bleb formation, also contributing to the preservation of myocardial blood flow or the reduced infarct size.

Intravenously injected ONO-1301–containing nanoparticles (ONO-1301NPs), unlike an ONO-1301 solution, selectively accumulated in the ischemia/reperfusion (I/R)-injured myocardium of rats and contributed to the prolonged retention of ONO-1301 in the targeted myocardial tissue. In the ischemic area, proangiogenic cytokines were up-regulated and inflammatory cytokines were down-regulated upon ONO-1301NP administration. Consequently, ONO-1301NP–injected rats exhibited a smaller infarct size, better-preserved capillary networks, and a better-preserved myocardial blood flow at 24 h after I/R injury, compared with those in vehicle-injected or ONO-1301 solution–injected rats. ONO-1301NPs attenuate the myocardial I/R injury via proangiogenic and anti-inflammatory effects of the drug.

Cordyceps militaris improves the survival of Dahl salt-sensitive hypertensive rats possibly via influences of mitochondria and autophagy functions

The genus Cordyceps and its specific ingredient, cordycepin, have attracted much attention for multiple health benefits and expectations for lifespan extension. We analyzed whether Cordyceps militaris (CM), which contains large amounts of cordycepin, can extend the survival of Dahl salt-sensitive rats, whose survival was reduced to ∼3 months via a high-salt diet. The survival of these life-shortened rats was extended significantly when supplemented with CM, possibly due to a minimization of the effects of stroke. Next, we analyzed the effect of CM on hypertension-sensitive organs, the central nervous systems (CNS), heart, kidney and liver of these rats. We attempted to ascertain how the organs were improved by CM, and we paid particular attention to mitochondria and autophagy functions. The following results were from CM-treated rats in comparison with control rats. Microscopically, CNS neurons, cardiomyocytes, glomerular podocytes, renal epithelial cells, and hepatocytes all were improved. However, immunoblot and immunohistochemical analysis showed that the expressions of mitochondria-related proteins, ATP synthase β subunit, SIRT3 and SOD2, and autophagy-related proteins, LC3-II/LC3-I ratio and cathepsin D all were reduced significantly in the CNS neurons, but increased significantly in the cells of the other three organs, although p62 was decreased in its expression in all the organs tested. Activity of Akt and mTOR was enhanced but that of AMPK was reduced in the CNS, while such kinase activity was completely the opposite in the other organs. Together, the influence of CM may differ between mitochondria and autophagy functioned between the two organ groups, as mitochondria and autophagy seemed to be repressed and promoted, respectively, in the CNS, while both mitochondria and autophagy were activated in the others. This could possibly be related to the steady or improved cellular activity in both the organs, which might result in the life extension of these rats.

Human Pluripotent Stem Cell-Derived Cardiac Tissue-like Constructs for Repairing the Infarcted Myocardium

High-purity cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are promising for drug development and myocardial regeneration. However, most hiPSC-derived CMs morphologically and functionally resemble immature rather than adult CMs, which could hamper their application. Here, we obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on low-thickness aligned nanofibers made of biodegradable poly(D,L-lactic-co-glycolic acid) polymer. We show that multilayered and elongated CMs could be organized at high density along aligned nanofibers in a simple one-step seeding process, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We also demonstrated the potential of CTLCs for modeling engraftments in vitro and treating myocardial infarction in vivo. Thus, we established a handy framework for cardiac tissue engineering, which holds high potential for pharmaceutical and clinical applications.

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hiPSC-CMs are seeded on aligned nanofibers to obtain 3D cardiac tissue-like constructs

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Drug assessment using CTLCs can be more robust than conventional cultures

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CTLCs can be used to model in vitro cardiac tissue engraftment

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CTLCs improve the function of rat hearts with myocardial infarction

Addition of mesenchymal stem cells enhances the therapeutic effects of skeletal myoblast cell-sheet transplantation in a rat ischemic cardiomyopathy model

INTRODUCTION

Functional skeletal myoblasts (SMBs) are transplanted into the heart effectively and safely as cell sheets, which induce functional recovery in myocardial infarction (MI) patients without lethal arrhythmia. However, their therapeutic effect is limited by ischemia. Mesenchymal stem cells (MSCs) have prosurvival/proliferation and antiapoptotic effects on co-cultured cells in vitro. We hypothesized that adding MSCs to the SMB cell sheets might enhance SMB survival post-transplantation and improve their therapeutic effects.

METHODS AND RESULTS

Cell sheets of primary SMBs of male Lewis rats (r-SMBs), primary MSCs of human female fat tissues (h-MSCs), and their co-cultures were generated using temperature-responsive dishes. The levels of candidate paracrine factors, rat hepatocyte growth factor and vascular endothelial growth factor, in vitro were significantly greater in the h-MSC/r-SMB co-cultures than in those containing r-SMBs only, by real-time PCR and enzyme-linked immunosorbent assay (ELISA). MI was generated by left-coronary artery occlusion in female athymic nude rats. Two weeks later, co-cultured r-SMB or h-MSC cell sheets were implanted or no treatment was performed (n=10 each). Eight weeks later, systolic and diastolic function parameters were improved in all three treatment groups compared to no treatment, with the greatest improvement in the co-cultured cell sheet transplantation group. Consistent results were found for capillary density, collagen accumulation, myocyte hypertrophy, Akt-signaling, STAT3 signaling, and survival of transplanted cells of rat origin, and were related to poly (ADP-ribose) polymerase-dependent signal transduction.

CONCLUSIONS

Adding MSCs to SMB cell sheets enhanced the sheets' angiogenesis-related paracrine mechanics and, consequently, functional recovery in a rat MI model, suggesting a possible strategy for clinical applications.

NOTCH1 expression predicts patient prognosis in esophageal squamous cell cancer

PURPOSE

The prognosis of patients with esophageal cancer remains poor, and the classification of tumor node metastasis has proven insufficient to predict patient prognosis. Therefore, novel predictive markers of esophageal cancer prognosis are needed. Notch receptors and their ligands have been reported to be upregulated in cervical, lung, colon, renal, and pancreatic cancers, but NOTCH1 expression has not been studied in esophageal cancer.

METHODS

Expression of NOTCH1 was quantified by real-time reverse transcription-polymerase chain reaction in 55 primary esophageal squamous cell carcinomas (ESCCs) and their paired normal esophageal mucosa. We then examined the correlations between NOTCH1 expression, clinicopathological factors, and prognosis in patients with ESCC.

RESULTS

The probability of overall survival was significantly lower for patients with high NOTCH1 expression (p = 0.0028; log-rank test). Overexpression of NOTCH1 was identified as a significant and independent prognostic factor (p = 0.0061) in patients who had undergone surgical treatment for ESCCs. The hazard ratio for predicting early death was 4.298 (95% confidence interval 1.515-12.195) for high versus low NOTCH1 expression.

CONCLUSIONS

Our data indicate that NOTCH1 may be a candidate molecular prognostic marker and a molecular target for the development of an effective therapeutic intervention for patients with ESCC.

A slow-releasing form of prostacyclin agonist (ONO1301SR) enhances endogenous secretion of multiple cardiotherapeutic cytokines and improves cardiac function in a rapid-pacing-induced model of canine heart failure

OBJECTIVES

Cardiac functional deterioration in dilated cardiomyopathy (DCM) is known to be reversed by intramyocardial up-regulation of multiple cardioprotective factors, whereas a prostacyclin analog, ONO1301, has been shown to paracrinally activate interstitial cells to release a variety of protective factors. We here hypothesized that intramyocardial delivery of a slow-releasing form of ONO1301 (ONO1301SR) might activate regional myocardium to up-regulate cardiotherapeutic factors, leading to regional and global functional recovery in DCM.

METHODS AND RESULTS

ONO1301 elevated messenger RNA and protein level of hepatocyte growth factor, vascular endothelial growth factor, and stromal-derived factor-1 of normal human dermal fibroblasts in a dose-dependent manner in vitro. Intramyocardial delivery of ONO1301SR, which is ONO1301 mixed with polylactic and glycolic acid polymer (PLGA), but not that of PLGA only, yielded significant global functional recovery in a canine rapid pacing-induced DCM model, assessed by echocardiography and cardiac catheterization (n = 5 each). Importantly, speckle-tracking echocardiography unveiled significant regional functional recovery in the ONO1301-delivered territory, consistent to significantly increased vascular density, reduced interstitial collagen accumulation, attenuated myocyte hypertrophy, and reversed mitochondrial structure in the corresponding area.

CONCLUSIONS

Intramyocardial delivery of ONO1301SR, which is a PLGA-coated slow-releasing form of ONO1301, up-regulated multiple cardiotherapeutic factors in the injected territory, leading to region-specific reverse left ventricular remodeling and consequently a global functional recovery in a rapid-pacing-induced canine DCM model, warranting a further preclinical study to optimize this novel drug-delivery system to treat DCM.

Resveratrol affects undifferentiated and differentiated PC12 cells differently, particularly with respect to possible differences in mitochondrial and autophagic functions

Since resveratrol is considered to exert a unique dual effect, protective for normal cells but toxic to tumor cells, its action on undifferentiated (original) and differentiated PC12 cells was analyzed, because undifferentiated cells are tumorigenic and differentiated ones are neuronal in nature. Compared to resveratrol-untreated cells in both undifferentiated and differentiated cell groups, cells treated with different doses of resveratrol, at dosages of 1, 10 and 100 μM, showed the following alterations. Dying/dead cells were significantly increased in a dose-dependent manner in undifferentiated cells, but they were unchanged at doses of up to 10 μM resveratrol in differentiated cells. In living cells, neurites were short in undifferentiated cells, but drastically elongated with an increased number in differentiated cells. The expression of SIRT1 was drastically reduced in undifferentiated cells, but stable in differentiated cells. SIRT3 was significantly enhanced in a dose-dependent manner at resveratrol doses of up to 10 μM in both cells, with reduction and more enhanced at a dosage of 100 μM in undifferentiated and differentiated cells, respectively. Mitochondrial number and ATP synthase β subunit expression was unaltered at doses of up to 10 μM and were significantly reduced at doses of 100 μM in undifferentiated cells, but they were significantly increased in a dose-dependent manner, with a slight reduction in the ATP synthase at doses of 100 μM, in differentiated cells. In a dose-dependent manner, the number of autophagosomes and the LC3-II/LC3-I ratio were significantly less in undifferentiated cells and greater in differentiated cells. Also, in a dose-dependent manner, the expression of phosphorylated AMP-activated kinase (AMPK) was significantly less in undifferentiated cells and greater in differentiated cells. Resveratrol-induced AMPK suppression and activation, possibly through the modulation of SIRT protein activity, may thus be related to the inhibition and promotion of mitochondrial and autophagic functions, leading to cell death and survival in undifferentiated and differentiated cells, respectively.

Very-high-dose alpha-tocopherol supplementation increases blood pressure and causes possible adverse central nervous system effects in stroke-prone spontaneously hypertensive rats

Tocopherols and tocotrienols constitute the vitamin E family. Although alpha-tocotrienol is the most neuroprotective form of vitamin E proved to be effective against stroke, alpha-tocopherol is the most abundant in nature and is used most often for disease prevention/treatment. A recent metaanalysis of human studies suggested that alpha-tocopherol supplementation increases all-cause mortality. Therefore, we investigated the effects of alpha-tocopherol ( approximately 44 mg/kg body weight; equivalent to 2,600 mg/human/day) on the central nervous system (CNS) of stroke-prone spontaneously hypertensive rats (SHRSP). SHRSP treated with high dose alpha-tocopherol had significantly higher blood pressure than untreated controls fed a basal diet that contained approximately 4 mg tocopherols/kg body weight, but neither group experienced a change in degree of lipid peroxidation in serum or CNS tissue. Biochemical/immunohistochemical analyses demonstrated that expressions of phosphorylated neurofilament H protein, glial fibrillary acidic protein and cathepsin D in the CNS tissue were significantly enhanced in alpha-tocopherol-supplemented rats, whereas expressions of SOD2 and Bcl-xL were diminished in response to alpha-tocopherol supplementation. Similarly, the frequency of cathepsin D-positive cells, corresponding mostly to microglial cells, was significantly increased in alpha-tocopherol-supplemented rats. Alpha-tocopherol supplementation also increased the number of lysosomes and lipofuscin granules in perikarya of both hippocampal pyramidal and Purkinje cells. Furthermore, alpha-tocopherol supplementation increased the frequency of glial filaments and lipofuscin granules in astrocytes and lysosomes in microglial cells that were frequently occupied with phagocytosed inclusion structures. The present results are the first to suggest that a very high dose of alpha-tocopherol supplementation increases blood pressure in SHRSP rats and influences the CNS tissue in a manner that seems adverse.

Hepatic gap junctions in the hepatocarcinogen-resistant DRH rat

Although the gap junction or connexin (Cx) is considered to be a tumor-suppressor, it is also required for tumor promotion. Therefore, we examined hepatic gap junctions in hepatocarcinogen-resistant (DRH) rats. Specifically, we investigated gap junction structure and Cx32 expression during normal conditions and in response to a hepatocarcinogen, 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB). On a basal diet without 3'-MeDAB, hepatic gap junctions and Cx32 protein expression were greater in DRH rats than in control Donryu rats, as evidenced by morphometry, immunohistochemistry and immunoblotting. On a diet containing 3'-MeDAB, gap junctions and expressed Cx32 were increased significantly in Donryu rats, but not in DRH rats. In this condition, Donryu rats lost weight but DRH rats increased relative liver weight. After 3'-MeDAB treatment, cathepsin D expression in hepatocytes was significantly increased only in Donryu rats, indicating that DRH rats were less susceptible to 3'-MeDAB. The abundance of mitogen-activated protein kinase, some constituent of which might be associated with the degree of Cx protein phosphorylation, was reduced to a greater extent in Donryu than in DRH rats after 3'-MeDAB treatment. The resistance of DRH rats to carcinogenesis may be due partially to their stabilized gap junctions, which could coordinate metabolic coupling to evade 3'-MeDAB toxicity.

Morphological and biochemical signs of age-related neurodegenerative changes in klotho mutant mice

Klotho mutant mice, defective in the klotho gene, develop multiple age-related disorders with very short lifespans. Introduction of the exogenous klotho gene into these mutant mice leads to an improvement in their phenotypes, while overexpression of this gene in wild-type mice significantly extends their lifespan. These observations suggest that the klotho gene/protein has an anti-aging function. Since there have been only a few reports with some disagreement about results on the CNS of the mutant mice, we tried to clarify whether the CNS neurons generate aging-like features, even in premature stages, using biochemical and morphological approaches. Results obtained from the mutant mice, when compared with wild-type mice, were as follows. Neurofilaments (NFs) were increased significantly in axons, with the subunit proteins showing a significant enhancement in phosphorylation or expression of NF-H or NF-L, respectively. Microtubules in Purkinje cell dendrites were closer to each other, and in the CNS tissue tubulin was unaltered, but microtubule-associated protein (MAP) 2 was significantly reduced in expression. Neuronal cellular organelles were morphologically disordered. Lysosomes, cathepsin D and light chain 3 of MAP1A/B (LC3) were augmented with the appearance of putative autophagy-related structures. Antiapoptotic Bcl-xL and proapoptotic Bax were reduced and enhanced, respectively, and mitogen-activated protein kinase was reduced. Synapse-related proteins and structures were decreased. Neuronal degeneration was evident in hippocampal pyramidal cells, and possibly in Purkinje cells. Astrocytic glial filaments and glial fibrillary acidic protein were increased in density and expression, respectively. Together, the CNS neuronal alterations in klotho mutant mice were quite similar to those found in aged animals, including even premature death, so this mouse should be a more appropriate animal model for CNS aging than those previously reported.

Aggregate formation and phosphorylation of neurofilament-L Pro22 Charcot-Marie-Tooth disease mutants

Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral nerve disorder. The causative gene for axonal type CMT2E has been identified as neurofilament light (NF-L) chain. Using cultured cells and in vitro assays, we analyzed the filament formation ability of Pro22 CMT mutant proteins of NF-L, P22S and P22T. NF-L Pro22 mutant proteins formed large aggregates in SW13- cells and cortical neurons and assembled into short twisty threads thinner than 10 nm filaments in vitro. Those threads associated with each other at their ends and entangled into large aggregates, also abnormalities, were detected at steps in oligomer formation. Pro22 mutations abolished Thr21 phosphorylation by cyclin-dependent kinase 5 and external signal regulated kinase, which suppressed filament assembly, but phosphorylation by protein kinase A (PKA) inhibited aggregate formation in vitro and alleviated aggregates in cortical neurons. These results indicate that the Pro22 CMT mutation induces abnormal filament aggregates by disrupting proper oligomer formation and the aggregates are mitigated by phosphorylation with PKA, which makes it a viable target for the development for therapeutics.

Synthesis and biological activity of 4',8-dihydroxyisoflavon-7-yl D-hexopyranosides

Four 4',8-dihydroxyisoflavon-7-yl hexopyranoside derivatives having an aglycon part of A-76202 were synthesized, and their biological activities were evaluated toward rat liver alpha-glucosidase. However, the activities were disappointing.

Synthesis of hydantocidin and C-2-thioxo-hydantocidin

Hydantocidin, a naturally occurring strong herbicide, was synthesized in an overall yield of 35.2%, with the accompanying 1'-epi-hydantocidin in overall 9.6% yield from 2,3-O-isopropylidene-D-ribono-1,4-lactone. C-2-thioxo-hydantocidin and its spiro-epimer were also synthesized in an overall yield of 14.4% and 8.5%, respectively.

Synthesis of lipid A type pyran carboxylic acids with ether chains and their biological activities

Synthesis of lipid A type pyran carboxylic acids having ether chains at both the C-3' and C-4 positions and their bioactivities toward human U937 cells are described.

Synthesis of GLA-60 type pyran carboxylic acids with an alkyl chain instead of an ester chain as LPS-antagonists

Synthesis of GLA-60 type pyran carboxylic acid analogues with an alkyl chain instead of an ester chain and their LPS-antagonist activity toward human U937 cells are described.

Synthesis and biological activities of lipid A-type pyrancarboxylic acid derivatives

The synthesis of lipid A-type pyrancarboxylic acid derivatives, which have a carboxylic acid group in the anomeric position of the reducing part of the disaccharide instead of the phosphate group in lipid A, is described. One of the compounds thus synthesized, which has an acyl substitution pattern similar to that of Escherichia coli lipid A, showed lipopolysaccharide (LPS)-agonistic activity. The other, which contains four lipid chains in the molecule, exhibited strong LPS-antagonistic activity toward human monoblastic U937 cells.

Overexpression of rck/p54, a DEAD box protein, in human colorectal tumours

The RCK gene is a target of the t(11;14)(q23;q32) chromosomal translocation observed in human B-cell lymphoma, and the overexpression of its protein (rck/p54) by the translocation was shown to cause malignant transformation. The rck/p54 protein belongs to the DEAD box protein/RNA helicase family, which has a variety of functions such as translation initiation, pre-mRNA splicing and ribosome assembly. The expression of rck p54 in colorectal adenocarcinoma cells was examined by immunohistochemistry and Western blot analysis. The rck/p54 protein was found to be overexpressed in tumour tissues resected from 13 (50%) out of 26 cases of colorectal adenocarcinomas and two out of two (100%) cases of colonic severe dysplastic adenomas. In view of activities of rck/p54 determined in other tissue types, we suggest that rck/p54 may contribute to the cell proliferation and carcinogenesis at the translational level in the development of colorectal tumours.

Heat stress activates fission yeast Spc1/StyI MAPK by a MEKK-independent mechanism

Fission yeast Spc1/StyI MAPK is activated by many environmental insults including high osmolarity, oxidative stress, and heat shock. Spc1/StyI is activated by Wis1, a MAPK kinase (MEK), which is itself activated by Wik1/Wak1/Wis4, a MEK kinase (MEKK). Spc1/StyI is inactivated by the tyrosine phosphatases Pyp1 and Pyp2. Inhibition of Pyp1 was recently reported to play a crucial role in the oxidative stress and heat shock responses. These conclusions were based on three findings: 1) osmotic, oxidative, and heat stresses activate Spc1/StyI in wis4 cells; 2) oxidative stress and heat shock activate Spc1/StyI in cells that express Wis1AA, in which MEKK consensus phosphorylation sites were replaced with alanine; and 3) Spc1/StyI is maximally activated in Deltapyp1 cells. Contrary to these findings, we report: 1) Spc1/StyI activation by osmotic stress is greatly reduced in wis4 cells; 2) wis1-AA and Deltawis1 cells have identical phenotypes; and 3) all forms of stress activate Spc1/StyI in Deltapyp1 cells. We also report that heat shock, but not osmotic or oxidative stress, activate Spc1 in wis1-DD cells, which express Wis1 protein that has the MEKK consensus phosphorylation sites replaced with aspartic acid. Thus osmotic and oxidative stress activate Spc1/StyI by a MEKK-dependent process, whereas heat shock activates Spc1/StyI by a novel mechanism that does not require MEKK activation or Pyp1 inhibition.

Activin A: a commitment factor in erythroid differentiation

Erythropoietin is known to be an essential hemopoietic growth factor for maturation of erythroid progenitor cells. Like other hemopoietic growth factors, erythropoietin acts as a survival factor that supports maturation of the erythroid progenitor through the suppression of apoptosis. It is unclear whether erythropoietin can also induce differentiation, or if another external regulator is needed to initiate this process. The present study using murine cell lines revealed that maturation of the erythroid lineage requires costimulation by activin A and erythropoietin. Erythropoietin alone dose not induce differentiation and cells stimulated by activin A alone undergo apoptotic death. Costimulation with erythropoietin and activin A, however, rescues the cells from apoptotic death and permits differentiation. Two-step cultivation showed that cells pretreated with activin A no longer need activin A and differentiate in the presence of erythropoietin alone. The action of activin A commits the cell to death or to differentiation, and the presence of erythropoietin enables differentiation through suppression of apoptosis.

Mcs4 mitotic catastrophe suppressor regulates the fission yeast cell cycle through the Wik1-Wis1-Spc1 kinase cascade

Spc1 in Schizosaccharomyces pombe is a member of the stress-activated protein kinase family, an evolutionary conserved subfamily of mitogen-activated protein kinases (MAPKs). Spc1 is activated by a MAPK kinase homologue, Wis1, and negatively regulated by Pyp1 and Pyp2 tyrosine phosphatases. Mutations in the spc1+ and wis1+ genes cause a G2 cell cycle delay that is exacerbated during stress. Herein, we describe two upstream regulators of the Wis1-Spc1 cascade. wik1+ (Wis1 kinase) was identified from its homology to budding yeast SSK2, which encodes a MAPKK kinase that regulates the HOG1 osmosensing pathway. Delta wik1 cells are impaired in stress-induced activation of Spc1 and show a G2 cell cycle delay and osmosensitive growth. Moreover, overproduction of a constitutively active form of Wik1 induces hyperactivation of Spc1 in wis1(+)-dependent manner, suggesting that Wik1 regulates Spc1 through activation of Wis1. A mutation of mcs4+ (mitotic catastrophe suppressor) was originally isolated as a suppressor of the mitotic catastrophe phenotype of a cdc2-3w wee1-50 double mutant. We have found that mcs4- cells are defective at activation of Spc1 in response to various forms of stress. Epistasis analysis has placed Mcs4-upstream of Wik1 in the Spc1 activation cascade. These results indicate that Mcs4 is part of a sensor system for multiple environmental signals that modulates the timing of entry into mitosis by regulating the Wik1-Wis1-Spc1 kinase cascade. Inactivation of the sensor system delays the onset of mitosis and rescues lethal premature mitosis in cdc2-3w wee1-50 cells.

Nitric oxide donor SNAP induces apoptosis in smooth muscle cells through cGMP-independent mechanism

Recent evidence suggests that nitric oxide (NO) may function as a second messenger in the intracellular signal transduction pathways. We explored the possibility that NO was involved in the signal for triggering apoptosis in smooth muscle cells (SMCs). Chemical NO donors induced SMCs apoptosis in a concentration- and time-dependent manner. The membrane-permeable cGMP analogue, dibutyryl-cGMP, did not induce SMCs apoptosis, and the highly selective inhibitor of cGMP-dependent protein kinase, KT5823, was unable to inhibit the induction of NO-induced SMCs apoptosis. Inhibitor of ADP-ribosyltransferase slightly attenuated the induction of SMCs apoptosis by S-nitroso-N-acetyl penicillamine (SNAP). The inhibitor of Na+-H+ antiporter, amiloride, completely inhibited the induction of SMCs apoptosis by SNAP. These results demonstrate for the first time that NO can induce apoptosis in SMCs, suggesting that NO acts as a mediator in the development of atherosclerosis lesion via alterations in the number of SMCs. In addition, the results suggest that NO exert these effects through a pathway that does not involve guanylate cyclase and cGMP-dependent protein kinase.

Syntheses of 1-O-carboxyalkyl GLA-60 analogues

As part of our ongoing study to survey potent LPS antagonists, the following six compounds were synthesized in an efficient manner: 3-carboxypropyl and carboxymethyl 2-deoxy-2-(2,2-difluorotetradecanamido)-4-O-phosphono-3-O-[(R)-3- (tetradecanoyloxy)tetradecanoyl]-alpha- and beta-D-glucopyranosides (11 and 23; 32 and 36), as well as the non-fluorinated equivalents, carboxymethyl 2-deoxy-4-O-phosphono-2-tetradecanamido-3-O-[(R)-3-(tetradecano yloxy)- tetradecanoyl]-alpha-D-glucopyranoside (44) and carboxymethyl 2-deoxy-2-[(R)-3-(hydroxy)tetradecanamido]-4-O-phosphono-3-O-[(R)- 3- (tetradecanoyloxy)tetradecanoyl]-alpha-D-glucopyranoside (48). Of these compounds, 32 was most pronounced in terms of LPS-antagonistic activity.

Anti-activin A antibody (IgY) specifically neutralizes various activin A activities

Activin A (beta A beta A), originally isolated from ovarian follicular fluids as a follicule-stimulating hormone (FSH) secretion stimulator, has also been identified as an erythroid differentiation factor (EDF), a neuron survival factor and a mesoderm-inducing factor. Thus, activin A is a multifunctional factor, and further studies on its physiological function are important. However, it is very difficult to produce a specific antibody to neutralize the activity of activin A because of its highly conserved amino acid sequence across mammalian species. In this study, we succeeded in generating an antibody against activin A, which can neutralize several activities of activin A, such as the stimulation of FSH secretion from pituitary cells and the induction of the differentiation of erythrocytes in vitro. This antibody did not affect the activity of activin B (beta B beta B), which induces the differentiation of erythrocytes in vitro, and the activity of inhibin A (alpha beta A), which inhibits FSH secretion from pituitary in vitro, but slightly neutralized that of activin AB (beta A beta B). Western blotting analysis showed that this antibody recognized both dimeric and monomeric forms of the beta A subunit of activin and inhibin. These results suggest that this antibody recognizes the beta A subunit of activin and specifically neutralizes the activity of a dimer of the beta A subunit, activin A. Furthermore, by the addition of this antibody to the culture medium, the development of murine embryos was suppressed, suggesting that endogenous activin A plays an important role in murine development. These results indicate the usefulness of this antibody for studies of endogenous activin actions.

Syntheses of 1-O-[5-(carboxy)pentanoyl]-2-deoxy-2-(2,2- difluorotetradecanamido)-3-O-[(R)-3-(tetradecanoyloxy)tetradecanoyl]-4- O- phosphono-alpha-D-glucopyranose and its analogues

1-O-[5-(Carboxy)pentanoyl]-2-deoxy-2-(2,2-difluorotetradecanamido) -3-O- [(R)-3-(tetradecanoyl-oxy)tetradecanoyl]-4-O-phosphono-alpha-D-glucop yranos e (13) and its analogues (16 and 19) were synthesized. Compound 13 showed strong LPS-agonistic activity.

Synthesis of 5-epi-trehazolin (trehalostatin)

Synthesis of 5-epi-trehazolin (trehalostatin) (2) was accomplished via the crucial intermediate, epoxide (6 alpha), from D-glucose. The stereochemistry of epoxide (6 alpha) and its isomer (6 beta) which were obtained from Sharpless epoxidation, was determined by comparison between the NMR relaxation times of relevant protons.

Synthesis of trehazolin beta-anomer

Synthesis of trehazolin beta-anomer (3) from a D-glucose derived azido alcohol (4), was accomplished. 2-Chloro-1-methylpyridinium iodide was used in place of 2-chloro-3-ethylbenzoxazolium tetrafluoroborate as a means of preventing concomitant anomerization. Evaluation of compound (3) reveals that the stereochemistry of the anomeric position is significant for generation of inhibitory activities towards trehalases.

Synthesis of 2-deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]- 3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and its (2S,3R)-isomer

2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[( 3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and its (2S,3R)-isomer were respectively synthesized from allyl 2-[(2R,3S)-3-(benzyloxycarbonyloxy)-2-fluorotetradecanamido] -2-deoxy-4,6-O-isopropylidene-beta-D-glucopyranoside and its corresponding (2S,3R)-isomer. Both target compounds did not activate macrophage, but the (2S,3R)-analogue strongly inhibited the binding of LPS to macrophage.

Distribution of connectin (titin) and transverse tubules at myotendinous junctions

The ends of muscle fibers form many longitudinal projections which are further divided into numerous processes and attach to the collagen fibrils of tendons to form myotendinous junctions (MTJs). Immunocytochemical and electron microscopic observations on pectoralis muscles of the chicken revealed the presence of an elastic filamentous protein, connectin (titin), within the terminal sarcomere on the side adjacent to the terminal Z bands, and the absence of connectin and myosin and the presence of actin at the apical sarcoplasmic region of MTJ processes between the terminal Z band and the MTJ sarcolemma. Intermediate voltage electron microscopy showed that T tubules in the terminal sarcomere were absent at the level of the A-I junction on the MTJ side in the rat vastus intermedius, and at the level of the terminal Z band or under the MTJ subsarcolemmal densities in the chicken pectoralis.