Acquired resistance of leukemic cells to AraC is associated with the upregulation of aldehyde dehydrogenase 1 family member A2.

The elucidation of drug resistance mechanisms is important in the development of clinical therapies for the treatment of leukemia. To study the drug resistance mechanisms, protein expression profiles of 1-β-D-arabinofuranosylcytosine (AraC)-sensitive K562 (K562S) cells and AraC-resistant K562 (K562AC) cells were compared using two-dimensional fluorescence difference gel electrophoresis. In a comparison of protein expression profiles, 2073 protein spots were found to be altered, and 15 proteins of them were remarkably altered. These proteins were identified by mass spectrometry. The most differently expressed proteins were aldehyde dehydrogenase 1 family member A2 (ALDH1A2) and vimentin. Both proteins were verified using reverse transcriptase polymerase chain reaction and Western blot analysis. ALDH1A2 protein was found to be effective in AraC resistance. ALDH1A2 knock-down induced sensitivity to AraC treatment in K562AC cells, and ALDH1A2 overexpressed K562S cells acquired the AraC resistance. Furthermore, the findings also suggest that ALDH1A2 expression is increased after the appearance of AraC resistance in clinical cases. These results will be helpful in understanding the mechanism of AraC resistance

CNVs in Three Psychiatric Disorders

BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25–0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD

Activation-induced cytidine deaminase によるTetファミリータンパク質の細胞内局在制御

京都大学0048新制・課程博士博士(人間健康科学)甲第17471号人健博第4号新制||人健||1(附属図書館)30237京都大学大学院医学研究科人間健康科学系専攻(主査)教授 足立 壯一, 教授 細田 公則, 教授 青井 貴之学位規則第4条第1項該当Doctor of Human Health SciencesKyoto UniversityDA

Three lines of induced pluripotent stem cells derived from a 15q11.2-q13.1 duplication syndrome patient

Duplications at the 15q11.2-q13.1 region are associated with psychiatric disorders such as developmental delay and autism spectrum disorder. However, the specific influence of these duplications on human neuronal cells remains unclear. Here we generated induced pluripotent stem cells (iPSCs) derived from a patient with 15q11.2-q13.1 duplication syndrome. The generated iPSCs carried 15q11.2-q13.1 duplication and showed typical iPSC morphology and pluripotency marker expression, and the capacity to differentiate into three germ layers. These iPSC lines will contribute to further understanding the pathology of 15q11.2-q13.1 duplication syndrome and help develop drugs to treat psychiatric disorders

Induced pluripotent stem cells derived from a schizophrenia patient with ASTN2 deletion

Astrotactin-2, encoded by ASTN2, is implicated in neuronal migration. Although genetic studies of schizophrenia (SCZ) patients have suggested that exonic deletions of ASTN2 are associated with neurodevelopmental and psychiatric disorders, their biological significance remains unclear. Herein, we generated human induced pluripotent stem cells (iPSCs) from a SCZ patient with an exonic deletion of ASTN2. The generated iPSCs carried ASTN2 deletion and showed typical iPSC morphology, pluripotency marker expression, normal chromosomal aneuploidy, and the capacity to differentiate into three germ layers. This iPSC line may be suitable for evaluating Astrotactin-2 function relevant for SCZ onset in the human brain

Remarkable Role of Indoleamine 2,3-Dioxygenase and Tryptophan Metabolites in Infectious Diseases: Potential Role in Macrophage-Mediated Inflammatory Diseases

Indoleamine 2,3-dioxygenase 1 (IDO1), the L-tryptophan-degrading enzyme, plays a key role in the immunomodulatory effects on several types of immune cells. Originally known for its regulatory function during pregnancy and chronic inflammation in tumorigenesis, the activity of IDO1 seems to modify the inflammatory state of infectious diseases. The pathophysiologic activity of L-tryptophan metabolites, kynurenines, is well recognized. Therefore, an understanding of the regulation of IDO1 and the subsequent biochemical reactions is essential for the design of therapeutic strategies in certain immune diseases. In this paper, current knowledge about the role of IDO1 and its metabolites during various infectious diseases is presented. Particularly, the regulation of type I interferons (IFNs) production via IDO1 in virus infection is discussed. This paper offers insights into new therapeutic strategies in the modulation of viral infection and several immune-related disorders

Behavior of leucine-rich repeat-containing G-protein coupled receptor 5-expressing cells in the reprogramming process

It remains unclear what cells are proper for the generation of induced pluripotent stem cells (iPSCs). Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) is well known as a tissue stem cell and progenitor marker, both of which are reported to be sensitive to reprogramming. In the present study, we examined the reprogramming behavior of Lgr5-expressing cells (Lgr5 + cells). First, we compared reprogramming behavior using mouse Lgr5 + and Lgr5 negative (Lgr5 −) hair follicles (HFs). The number of alkaline phosphatase staining-positive cells was lesser in a well of Lgr5 + HFs than in Lgr5 − HFs; however, the ratio of Nanog + SSEA1 + cells in the cell mixture derived from Lgr5 + HFs was much higher than that from Lgr5 − HFs. Lgr5 + cells could be induced from mouse embryonic fibroblasts (MEFs) after transduction with Yamanaka factors. As shown in HFs, the progeny of Lgr5 + cells arising from MEFs highly converted into Nanog + cells and did not form Nanog − colonies. The progeny represented the status of the late reprogramming phase to a higher degree than the nonprogeny. We also confirmed this using human Lg5 + cells. Our findings suggest that the use of Lgr5 + cells will minimize sorting efforts for obtaining superior iPSCs

Activation-Induced Cytidine Deaminase Alters the Subcellular Localization of Tet Family Proteins

<div><p>Activation-induced cytidine deminase (Aid), a unique enzyme that deaminates cytosine in DNA, shuttles between the nucleus and the cytoplasm. A recent study proposed a novel function of Aid in active DNA demethylation via deamination of 5-hydroxymethylcytosine, which is converted from 5-methylcytosine by the Ten-eleven translocation (Tet) family of enzymes. In this study, we examined the effect of simultaneous expression of Aid and Tet family proteins on the subcellular localization of each protein. We found that overexpressed Aid is mainly localized in the cytoplasm, whereas Tet1 and Tet2 are localized in the nucleus, and Tet3 is localized in both the cytoplasm and the nucleus. However, nuclear Tet proteins were gradually translocated to the cytoplasm when co-expressed with Aid. We also show that Aid-mediated translocation of Tet proteins is associated with Aid shuttling. Here we propose a possible role for Aid as a regulator of the subcellular localization of Tet family proteins.</p> </div

Tet1 translocation requires its catalytic domain.

<p>(A) A schematic representation of the Tet1 structure and its mutants used in this study. (aa = amino acid). (B) Confocal images of DLD-1 cells transiently expressing N-terminally Xpress-tagged Tet1 mutants with or without C-terminally Myc-tagged Aid. All Tet1 constructs (FL, CD and ΔCD) were localized in the nucleus when solely expressed in DLD-1 cells. When co-expressed with Aid, Tet1FL and Tet1CD were translocated to the cytoplasm, whereas Tet1ΔCD remained in the nucleus. (C) Each bar represents the proportion of cells with the different localizations of Tet1. The number (n) of cells indicated above each bar was scored according to their subcellular localization. N (black); nuclear localization, N+C (gray); both nuclear and cytoplasmic localization, C (white); cytoplasmic localization in multiple microscope fields. The scale bars in images are 10 µm. *p<0.01.</p