幹細胞におけるデルマタン硫酸の機能

Mouse embryonic stem cells (mESCs) have self-renewal and pluripotency. Various signals and growth factors maintain undifferentiated state and regulate differentiation of mESCs. Glycosylation is a one of the post-translational modifications. Glycans have various structures and are conjugated to proteins and lipids. Many proteins on the cell surface and secreted proteins are glycosylated and contribute to important biological phenomena. The signal regulation is one of them, in which signal ligands and receptors bind to specific glycan structures. Previously, we and other groups reported that heparan sulphate, one of glycosaminoglycans, contributes to maintenance of undifferentiated state and regulation of mESCs differentiation. It has been shown that chondroitin sulfate is needed for pluripotency and differentiation of mESCs, while keratan sulfate is a known marker of human ESCs / iPSCs. However, the function of dermatan sulphate (DS) in mESCs has not been fully elucidated. Here, we performed (1) induction of neuronal differentiation in mESCs and human neural stem cells adding purified DS and (2) knockdown or overexpression of the dermatan-4-O-sulfotransferase-1 (D4ST1) in mESCs. We revealed that (1) DS promotes neuronal differentiation in both mouse and human stem cells and (2) D4ST1 contributes to the undifferentiated state of mESCs.創価大

The Effect of Grazing on Fecal Shedding of Pathogenic Escherichia coli in Beef Cattle

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Hepatic Interleukin-7 Expression Regulates T Cell Responses

SummarySystemic cytokine activity in response to Toll-like receptor (TLR) signaling induces the expression of various proteins in the liver after infections. Here we show that Interleukin-7 (IL-7), the production of which was thought to occur at a constant rate in vivo, was a hepatically expressed protein that directly controled T cell responses. Depletion of IL-7 expression in the liver abrogated several TLR-mediated T cell events, including enhanced CD4+ T cell and CD8+ T cell survival, augmented CD8+ T cell cytotoxic activity, and the development of experimental autoimmune encephalitis, a Th17 cell-mediated autoimmune disease. Thus, T cell responses are regulated by hepatocyte-derived IL-7, which is expressed in response to TLR signaling in vivo. We suggested that TLR-induced IL-7 expression in the liver, which is an acute-phase response, may be a good diagnostic and therapeutic target for efficient vaccine developments and for conditions characterized by TLR-mediated T cell dysregulation, including autoimmune diseases

Induction of DNA Methylation by Artificial piRNA Production in Male Germ Cells

SummaryGlobal DNA demethylation and subsequent de novo DNA methylation take place in mammalian male embryonic germ cells [1–3]. P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs), which are germline-specific small RNAs, have been postulated to be critically important for de novo DNA methylation of retrotransposon genes, and many proteins, including PIWI family proteins, play pivotal roles in this process [4–6]. In the embryonic mouse testis, two mouse PIWI proteins, mouse PIWI-like (MILI) and mouse PIWI2 (MIWI2), are involved in the biogenesis of piRNAs through the so-called ping-pong amplification cycle [7–10], and long single-stranded RNAs transcribed from the gene regions of piRNA clusters have been proposed to be the initial material [11–16]. However, it remains unclear whether transcription from the piRNA clusters is required for the biogenesis of piRNAs. To answer this question, we developed a novel artificial piRNA production system by simple expression of sense and antisense EGFP mRNAs in embryonic male germ cells in the piRNA biogenesis phase. EGFP expression was silenced by piRNA-dependent DNA methylation, indicating that concomitant expression of sense and antisense RNA transcripts is necessary and sufficient for piRNA production and subsequent piRNA-dependent gene silencing. In addition, we demonstrated that this artificial piRNA induction paradigm could be applied to an endogenous gene essential for spermatogenesis, DNMT3L [3, 17, 18]. This study not only provides novel insights into the molecular mechanisms of piRNA production, but also presents an innovative strategy for inducing epigenetic modification in germ cells

Effectiveness of prehospital Magill forceps use for out-of-hospital cardiac arrest due to foreign body airway obstruction in Osaka City

Background: Although foreign body airway obstruction (FBAO) accounts for many preventable unintentional accidents, little is known about the epidemiology of FBAO patients and the effect of forceps use on those patients. This study aimed to assess characteristics of FBAO patients transported to hospitals by emergency medical service (EMS) personnel, and to verify the relationship between prehospital Magill forceps use and outcomes among out-of-hospital cardiac arrests (OHCA) patients with FBAO. Methods: We retrospectively reviewed ambulance records of all patients who suffered FBAO, and were treated by EMS in Osaka City from 2000 through 2007, and assessed the characteristics of those patients. We also performed a multivariate logistic-regression analysis to assess factors associated with neurologically favorable survival among bystander-witnessed OHCA patients with FBAO in larynx or pharynx. Results: A total of 2,354 patients suffered from FBAO during the study period. There was a bimodal distribution by age among infants and old adults. Among them, 466 (19.8%) had an OHCA when EMS arrived at the scene, and 344 were witnessed by bystanders. In the multivariate analysis, Magill forceps use for OHCA with FBAO in larynx or pharynx was an independent predictor of neurologically favorable survival (16.4% [24/146] in the Magill forceps use group versus 4.3% [4/94] in the non-use group; adjusted odds ratio, 3.96 [95% confidence interval, 1.21-13.00], p = 0.023).Conclusions: From this large registry in Osaka, we revealed that prehospital Magill forceps use was associated with the improved outcome of bystander-witnessed OHCA patients with FBAO

Site-specific O-GlcNAcylation of Psme3 maintains mouse stem cell pluripotency by impairing P-body homeostasis

Mouse embryonic stem cell (ESC) pluripotency is tightly regulated by a complex network composed of extrinsic and intrinsic factors that allow proper organismal development. O-linked β-N-acetylglucosamine (O-GlcNAc) is the sole glycosylation mark found on cytoplasmic and nuclear proteins and plays a pivotal role in regulating fundamental cellular processes; however, its function in ESC pluripotency is still largely unexplored. Here, we identify O-GlcNAcylation of proteasome activator subunit 3 (Psme3) protein as a node of the ESC pluripotency network. Mechanistically, O-GlcNAc modification of serine 111 (S111) of Psme3 promotes degradation of Ddx6, which is essential for processing body (P-body) assembly, resulting in the maintenance of ESC pluripotent state. Conversely, loss of Psme3 S111 O-GlcNAcylation stabilizes Ddx6 and increases P-body levels, culminating in spontaneous exit of ESC from the pluripotent state. Our findings establish O-GlcNAcylation at S111 of Psme3 as a switch that regulates ESC pluripotency via control of P-body homeostasis