ALBERT

Beschreibung: Reduction in chromosome mobility accompanies nuclear organization during early embryogenesis in Caenorhabditis elegans Scientific Reports, Published online: 16 June 2017; doi:10.1038/s41598-017-03483-5

Beschreibung: Sounding-rocket microgravity experiments on alumina dust Sounding-rocket microgravity experiments on alumina dust, Published online: 19 September 2018; doi:10.1038/s41467-018-06359-y Alumina is thought to be the main condensate to form in the gas outflow from oxygen-rich evolved stars. Here, the authors perform a condensation experiment with alumina in a low-gravity environment, and find spectroscopic evidence for a sharp feature at a wavelength of 13.55 μm.

Beschreibung: Mitochondrial E3 ubiquitin ligase MITOL/March5 translocates from depolarized mitochondria to peroxisomes following mitophagy stimulation. Ubiquitylation of MITOL at K268 by Parkin is required for p97/VCP‐dependent extraction from damaged mitochondria. Abstract Ubiquitylation of outer mitochondrial membrane (OMM) proteins is closely related to the onset of familial Parkinson's disease. Typically, a reduction in the mitochondrial membrane potential results in Parkin‐mediated ubiquitylation of OMM proteins, which are then targeted for proteasomal and mitophagic degradation. The role of ubiquitylation of OMM proteins with non‐degradative fates, however, remains poorly understood. In this study, we find that the mitochondrial E3 ubiquitin ligase MITOL/March5 translocates from depolarized mitochondria to peroxisomes following mitophagy stimulation. This unusual redistribution is mediated by peroxins (peroxisomal biogenesis factors) Pex3/16 and requires the E3 ligase activity of Parkin, which ubiquitylates K268 in the MITOL C‐terminus, essential for p97/VCP‐dependent mitochondrial extraction of MITOL. These findings imply that ubiquitylation directs peroxisomal translocation of MITOL upon mitophagy stimulation and reveal a novel role for ubiquitin as a sorting signal that allows certain specialized proteins to escape from damaged mitochondria.

Beschreibung: Studies on nasal T/natural killer (NK)–cell lymphoma have been hampered by its tendency to cause necrosis. Thus, the establishment of cell lines of this neoplasm would seem to be valuable. This study attempted to establish cell lines from primary lesions of this tumor, and successfully obtained 2 novel Epstein-Barr virus (EBV)–positive cell lines, SNK-6 and SNT-8, by means of high-dose recombinant interleukin 2. Flow cytometry showed that SNK-6 had an NK-cell phenotype, CD3−CD4−CD8−CD19−CD56+T-cell receptor (TCR) α/β− TCR γ/δ−, whereas SNT-8 was CD3+CD4−CD8−CD19−CD56+TCR α/β− TCR γ/δ+. These were consistent with immunophenotypes of their original tumors, and the cell lines had monoclonal EBV clones identical to ones in their original tumors. Thus, the cell lines developed from cells forming the primary lesions. Genotypic analysis showed that SNK-6 had unrearranged TCR and immunoglobulin heavy-chain genes, supporting the conclusion that SNK-6 was of NK-cell lineage. On the other hand, SNT-8 had rearranged TCR β-, γ-, and δ-chain genes, and together with its phenotype, SNT-8 proved to be a γδ T-cell line. This is the first report of the establishment of cell lines from primary lesions of nasal T/NK cell lymphomas, and the results demonstrated that there are at least 2 lineages, NK- and γδ T-cell, in this neoplasm. Moreover, it has been suggested that nasal T/NK cell lymphomas of these lineages may belong to the same clinicopathologic entity because both types of cases shared common clinical and histopathologic features.

Beschreibung: The molecular basis of ineffective hematopoiesis in myelodysplastic syndromes (MDS) has yet to be defined. Elevation of tumor necrosis factor (TNF)-α in bone marrow plasma has been considered to be a cause of apoptosis of hematopoietic progenitor cells, and this could result in ineffective hematopoiesis in MDS. However, the mechanism of TNF-α elevation has not been elucidated. We recently found aberrant regulation of c-fos mRNA stability in neutrophils isolated from MDS patients (Feng et al, PLoS ONE, 2013). Since the expression levels of RNA-binding proteins that regulated c-fos mRNA stability were not altered in the majority of the patients and no mutations were detected in c-fos mRNA, microRNAs were possibly involved in the insufficient stabilization of c-fos mRNA. In this study, we chose 20 microRNAs targeting c-fos according to four different databases and compared their expression levels in neutrophils between MDS patients and healthy volunteers. Among them, miR-34a and miR-155 were significantly increased in MDS (p

Beschreibung: Using the intra-bone marrow injection (IBMI) method, we have identified human cord blood (CB)-derived CD34-negative (CD34−) severe combined immunodeficiency (SCID)-repopulating cells (SRCs) with multi-lineage repopulating ability (Blood101:2924,2003). Functional studies revealed that these CD34− SRCs have different hematopoietic stem cell (HSC) characteristics from CD34+ SRCs. In order to further clarify the HSC characteristics of CD34− SRCs, here we investigate the proliferative potential and redistribution kinetics of human CB-derived CD34− SRCs, and compare them with those of CD34+CD38+/− SRCs using IBMI. First, we performed limiting dilution analyses and revealed that the incidence of CD34+CD38− SRCs in CB-derived Lin−CD34+CD38− cells was 1 out of 41 cells by IBMI. In contrast, the incidence of CD34− SRCs in Lin−CD34− cells was 1 out of 24,100, as we previously reported. Based on these data, we transplanted 200 to 5,000 Lin−CD34+CD38− cells (containing 5 to 120 SRCs), 15,000 to 50,000 Lin−CD34+CD38+ cells (containing 10 to 30 SRCs), or 60,000 to 70,000 Lin−CD34− cells (containing 3 SRCs) into primary recipient NOD/Shi-scid mice. After 5 weeks, all mice that received transplants of Lin−CD34+CD38+/− cells showed the human CD45+ cell repopulation in the other bones as well as the injected left tibiae. However, the human CD45+ cells were only detected in the injected left tibiae in mice that received transplants of Lin−CD34− cells 5 weeks after the transplantation. In the mice that received transplants of 200 Lin−CD34+CD38− cells (containing 5 SRCs), the CD45+CD34+ as well as CD45+CD34− cells were detected in both sites. In contrast, only CD45+CD34− cells were detected in the mice that received transplants of 70,000 Lin−CD34− cells (3 SRCs). These results suggested that CD34− SRCs might remain or slowly proliferate as CD34− cells at the site of injection for at least 5 weeks. Next, we serially investigated the human CD45+ cell repopulation in the injected site and the other bones, separately. Very interestingly, CD34+CD38+/− SRCs began to migrate 2 weeks after the transplantation. The human cell repopulation in these mice was observed in other bones by 3 weeks after transplantation. Moreover, these CD34+ SRCs actively proliferated at both sites and produced CD34+ progenies. In contrast, CD34− SRCs began to migrate 5 weeks after the transplantaion. Furthermore, these CD34− SRCs showed significantly higher proliferative potential 8 weeks after transplantation than CD34+ SRCs and produced more CD34+ progenies not only at the site of injection, but also in the other bones. These results indicated that CD34− SRC as well as CD34+CD38+/− SRCs could actively migrate from the injected site to the other bones. However, the time of initiation of migration was different between CD34+/− SRCs. All these findings indicate that CD34− SRCs show different proliferative potential and redistribution kinetics, and suggest that our identified CD34− SRCs are distinct class of primitive HSCs in comparison with CD34+CD38+/− SRCs. We are now in the progress of clarifying whether the CD34− SRCs migrate to other bones with the CD34− immunophenotype or after their conversion (differentiation) to the CD34+ cells.

Beschreibung: We have identified a specific dual Bcr-Abl/Lyn inhibitor, NS-187 (elsewhere described as CNS-9), which is 25–55 times more potent than imatinib against wild type Bcr-Abl in vitro. To evaluate the potential of NS-187 as a therapeutic agent, we assessed its in vivo activity. When Balb/c mice were given NS-187 orally at a dose of 30 mg/kg, the pharmacokinetic parameters were as follows: Tmax, 2 h; Cmax, 586 ng/ml; AUC0-∝, 2999 ng•h/ml; T1/2, 1.0 h; and bioavailability value (BA), 33%. The maximal tolerated dose (MTD) of NS-187 in Balb/c or Balb/c-nu/nu mice was 200 mg/kg/day (100 mg/kg, twice daily). To test the effect of NS-187 on in vivo tumor growth, Balb/c-nu/nu mice were injected subcutaneously with Bcr-Abl-positive KU812 cells on Day 0 and given NS-187 or imatinib orally twice a day from Day 7 to Day 17. At 20 mg/kg/day, imatinib inhibited tumor growth slightly, while at 200 mg/kg/day, it inhibited tumor growth almost completely. In contrast, at only 0.2 mg/kg/day NS-187 significantly inhibited tumor growth, while at 20 mg/kg/day it completely inhibited tumor growth without any adverse effects. The body weights of the treated tumor-bearing mice were not significantly different from those of untreated mice, even at a dosage of 200 mg/kg/day NS-187. Thus, NS-187 was at least 10-fold more potent than imatinib in vivo with complete inhibition of tumor growth as the end-point. We also tested the ability of NS-187 to suppress tumor growth in another murine tumor model, namely, Balb/c-nu/nu mice intravenously transplanted with BaF3 cells harboring wild type Bcr-Abl. The mice were treated orally with NS-187 or imatinib for 11 days starting on Day 1. All eight untreated mice and all eight mice treated with 400 mg/kg/day imatinib had died by Day 25 due to leukemic cell expansion, and NS-187 significantly prolonged the survival of the mice in a dose-dependent manner. We next examined the ability of NS-187 to block the in vivo growth of BaF3 cells harboring one of the Abl point-mutants M244V, G250E, Q252H, Y253F, T315I, M351T and H396P in Balb/c-nu/nu mice. These mice were treated with NS-187 or imatinib for 11 days starting on Day 1. NS-187 at 200 mg/kg/day significantly prolonged the survival of mice inoculated with BaF3 cells harboring any of these mutants except T315I compared with untreated or imatinib-treated mice (see Figure for an example). Thus, NS-187 was more potent than imatinib and could override the point-mutation-based imatinib-resistance mechanism in vivo. The efficacy and safety of NS-187 for Ph+ leukemias is expected to be verified by early-phase clinical trials. Figure Figure