Ethanol Increases NADPH Oxidase-derived Oxidative Stress and Induces Apoptosis in Human Liver Adenocarcinoma Cells (SK-HEP-1)

Alcohol-induced liver injury is linked to oxidative stress and increased production of reactive oxygen species (ROS). Oxidative stress is an early event in the process of apoptosis. However, it is not completely understood how ethanol-induced oxidative stress induces apoptosis. In contrast, nicotinamide adenine dinucleotide phosphate oxidase (NOX) is known to generate ROS in hepatocytes. The purpose of the present study was to determine whether or not ethanol-induced ROS generation stimulates the death receptor or mitochondrial pathways of apoptosis in alcohol dehydrogenase containing human liver adenocarcinoma (SK-HEP-1) cells. Treatment with ethanol increased the generation of ROS and expression of NOX4 mRNA, and also induced mitochondrial dysfunction in SK-HEP-1 cells. Moreover, ethanol induced the activation of caspase-8 and -3 in hepatocytes. These activities were suppressed by pretreatment with N-acetyl-cysteine, an antioxidant, or apocynin, an inhibitor of NOX activity. These results suggested that ethanol induces an increase in NOX-derived ROS generation upstream of caspase-8 activation and in the mitochondria in SK-HEP-1 cells. In conclusion, this study demonstrated that ethanol increases the generation of ROS and subsequently induces apoptosis using a mechanism involving mitochondrial dysfunction and caspase activation in SK-HEP-1 cells

Ethanol-induced Stress Leads to Apoptosls Via Endoplasmic Reticulum Stress in SK-Hepl Cells

Alcoholic liver disease causes oxidative stress and induces apoptosis during alcohol metabolism. Ethanol causes endoplasmic reticulum (ER) stress in hepatocytes, stimulating the unfolded protein response (UPR) pathway and/or Ca2+-dependent calpain and caspase-4 activities. However, it is poorly understood whether ethanol-induced oxidative stress directly leads to apoptosis promoted by ER stress-associated pathways. This study investigated this question in human liver adenocarcinoma (SK-Hep1) cells, which were treated with 200 mM ethanol for 5 hours in the presence or absence of the antioxidant N-acetyl-cysteine (NAC). We found that treatment with ethanol significantly increased ROS production and cellular apoptosis in the SK-Hep1 cells, and that this response was significantly suppressed by pretreatment with NAC. Furthermore, pretreatment with NAC significantly reduced the observed increases in the mRNA expressions of Bip, Chop, and sXbp-1, and the activity of caspase-3 in ethanol-induced apoptotic cells. However, pretreatment with NAC did not attenuate the transient rise in cytosolic Ca2+ nor the activities of caspase-4 and calpain induced by ethanol. Together, these results revealed that ethanol-induced stress promotes apoptosis not only through mitochondria-mediated pathways, but also via ER stress. The findings further suggested that ethanol-induced oxidative stress and non-oxidative stress both stimulate the pathway regulating ER stress-mediated apoptosis

Synthesis of Cysteine-Rich Peptides by Native Chemical Ligation without Use of Exogenous Thiols

Native chemical ligation (NCL) performed without resorting to the use of thiol additives was demonstrated to be an efficient and effective procedure for synthesizing Cys-rich peptides. This method using tris­(2-carboxyethyl)­phosphine (TCEP) as a reducing agent facilitates the ligation reaction even at the Thr-Cys or Ile-Cys site and enables one-pot synthesis of Cys-rich peptides throughout NCL and oxidative folding

<i>N</i>‑Sulfanylethyl­aminooxy­butyramide (SEAoxy): A Crypto-Thioester Compatible with Fmoc Solid-Phase Peptide Synthesis

An <i>N</i>-sulfanylethyl­amino­oxy­butyramide (SEAoxy) has been developed as a novel thioester equivalent for native chemical ligation. SEAoxy peptide was straightforwardly synthesized by conventional Fmoc solid-phase peptide synthesis without a problem. Moreover, SEAoxy peptide could be directly applied to native chemical ligation owing to the intramolecular <i>N</i>-to-<i>S</i> acyl shift that releases the peptide-thioester <i>in situ</i>. This methodology was successfully applied to the synthesis of two bioactive peptides

Increasing secular trends in height and obesity in children with type 1 diabetes: JSGIT cohort.

BackgroundRecently, anthropometric indices in children with type 1 diabetes mellitus (T1DM) have begun to change.ObjectiveTo examine secular trends in patients' anthropometric indices.SubjectsJapanese children with T1DM from the 1995, 2000, 2008 and 2013 cohorts of The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes.MethodsWe analysed serum haemoglobin A1c (HbA1c) levels, the incidence of severe hypoglycaemic events, the types and doses of insulin, height standard deviation scores (SDS), body mass index (BMI) percentiles compared with healthy Japanese children and obesity prevalence over time. We also stratified the patients according to glycaemic control levels of ResultsData for 513-978 patients from each of the cohorts were analysed. The incidence of severe hypoglycaemic events decreased over time (from 21 to 4.8/100 patient-years), while the proportion of insulin analogue doses increased (14.6% to 98.6%). In addition, patient height SDS (-0.22 to +0.17), BMI percentile (52.1 to 58.7) and obesity prevalence (2.1% to 5.1%) increased. Height SDS increased in all of the glycaemic control subgroups, while BMI percentile and obesity prevalence increased in the suboptimal and high-risk groups.ConclusionsSince 1995, the average height of children with T1DM has increased in parallel with increasing insulin doses. Clinicians should be aware of increased BMI in these patients and the associated risk of developing cardiovascular disease in the future

Classroom Discourse Analysis : Characteristic Linguistic Behavior of the Teachers

本研究は小学校の家庭科と算数，理科の授業，中学校の数学の授業をディスコース分析し，授業における教師の言語活動の特徴を解明した．教師は，教科内容，発達段階に応じて教師が自在に発話を用いて教室のディスコースを作り出していた．分析した６つの授業に共通することは，教師が「質問」や「活動の指示」を用いて，生徒に活動をさせ，生徒が参加する授業をつくっていたことである．分析結果から２つの生徒参加型授業における教師の言語活動の特徴が見出された．一つは，文脈にのせて知識を伝える生徒参加型の授業であり，もう一つは，「Ｉ・Ｒ・Ｅ」を用いた生徒参加型授業である．Based on field observation and discourse analysis this paper addresses the characteristic linguistic behavior of school teachers in classes in home economics, mathematics, science in elementary school and in one mathematics class in middle school. Our study shows that school teachers demonstrate flexibility in their approaches to class room activities, freely changing teaching strategies depending on study agenda and students’ learning level. They make use of questions, attempt to initiate discussion, suggest activities, and allow students to create their own activities. In these ways they attempt to lead students to actively participate in the class. Analyzing the linguistic behavior of teachers of classes in which students actively participate, we found two distinctive characteristics: 1. Embedding the knowledge to be conveyed in teacher-student discourse, ２. Structuring class discussion according to the I.R.E. model