Characteristics of Myeloid Differentiation and Maturation Pathway Derived from Human Hematopoietic Stem Cells Exposed to Different Linear Energy Transfer Radiation Types

Exposure of hematopoietic stem/progenitor cells (HSPCs) to ionizing radiation causes a marked suppression of mature functional blood cell production in a linear energy transfer (LET)- and/or dose-dependent manner. However, little information about LET effects on the proliferation and differentiation of HSPCs has been reported. With the aim of characterizing the effects of different types of LET radiations on human myeloid hematopoiesis, in vitro hematopoiesis in Human CD34⁺ cells exposed to carbon-ion beams or X-rays was compared. Highly purified CD34⁺ cells exposed to each form of radiation were plated onto semi-solid culture for a myeloid progenitor assay. The surviving fractions of total myeloid progenitors, colony-forming cells (CFC), exposed to carbon-ion beams were significantly lower than of those exposed to X-rays, indicating that CFCs are more sensitive to carbon-ion beams (D ₀ = 0.65) than to X-rays (D ₀ = 1.07). Similar sensitivities were observed in granulocyte-macrophage and erythroid progenitors, respectively. However, the sensitivities of mixed-type progenitors to both radiation types were similar.In liquid culture for 14 days, no significant difference in total numbers of mononuclear cells was observed between non-irradiated control culture and cells exposed to 0.5 Gy X-rays, whereas 0.5 Gy carbon-ion beams suppressed cell proliferation to 4.9% of the control, a level similar to that for cells exposed to 1.5 Gy X-rays. Cell surface antigens associated with terminal maturation, such as CD13, CD14, and CD15, on harvest from the culture of X-ray-exposed cells were almost the same as those from the non-irradiated control culture. X-rays increased the CD235a⁺ erythroid-related fraction, whereas carbon-ion beams increased the CD34⁺CD38⁻ primitive cell fraction and the CD13⁺CD14^+/−CD15⁻ fraction. These results suggest that carbon-ion beams inflict severe damage on the clonal growth of myeloid HSPCs, although the intensity of cell surface antigen expression by mature myeloid cells derived from HSPCs exposed to each type of radiation was similar to that by controls.     

The protective role of localized nitric oxide production during inflammation may be mediated by the heme oxygenase-1/carbon monoxide pathway

Nitric oxide (NO) is an important part of the host defense mechanism; however, it displays both pro- and anti-inflammatory properties depending on its location and concentration. Importantly, excessive or inappropriate NO production can cause tissue damage. Systemic and local administration of NO synthase (NOS) inhibitors ameliorates and may exacerbate the inflammatory response, respectively. Here, we used a carrageenan-induced pleurisy model of acute inflammation in rats to confirm the location-dependent effects of NO and investigate the underlying mechanisms. As expected, localized suppression of NO production exacerbated inflammation, as evidenced by increased pleural exudate volumes and leukocyte counts and enhanced activity of enzymes related to oxidative stress. In contrast, local NO supplementation reduced leukocyte infiltration, vascular permeability, and the activity of oxidative stress-related enzymes. Interestingly, inhibition of heme oxygenase-1 (HO-1) reversed the anti-inflammatory effects of localized NO production, while the addition of hemin (HO-1 substrate) or carbon monoxide (CO; HO-1 metabolite) decreased leukocyte migration and exudation. Together, these findings confirm a protective role for NO at the inflammatory site, which appears to be mediated via NOS induction of the HO-1/CO pathway. Thus, NO supplementation may be a potential new treatment for oxidative stress-associated inflammatory diseases.     

The Brain’s Response to the Human Voice Depends on the Incidence of Autistic Traits in the General Population

Optimal brain sensitivity to the fundamental frequency (F0) contour changes in the human voice is important for understanding a speaker’s intonation, and consequently, the speaker’s attitude. However, whether sensitivity in the brain’s response to a human voice F0 contour change varies with an interaction between an individual’s traits (i.e., autistic traits) and a human voice element (i.e., presence or absence of communicative action such as calling) has not been investigated. In the present study, we investigated the neural processes involved in the perception of F0 contour changes in the Japanese monosyllables “ne” and “nu.” “Ne” is an interjection that means “hi” or “hey” in English; pronunciation of “ne” with a high falling F0 contour is used when the speaker wants to attract a listener’s attention (i.e., social intonation). Meanwhile, the Japanese concrete noun “nu” has no communicative meaning. We applied an adaptive spatial filtering method to the neuromagnetic time course recorded by whole-head magnetoencephalography (MEG) and estimated the spatiotemporal frequency dynamics of event-related cerebral oscillatory changes in beta band during the oddball paradigm. During the perception of the F0 contour change when “ne” was presented, there was event-related de-synchronization (ERD) in the right temporal lobe. In contrast, during the perception of the F0 contour change when “nu” was presented, ERD occurred in the left temporal lobe and in the bilateral occipital lobes. ERD that occurred during the social stimulus “ne” in the right hemisphere was significantly correlated with a greater number of autistic traits measured according to the Autism Spectrum Quotient (AQ), suggesting that the differences in human voice processing are associated with higher autistic traits, even in non-clinical subjects.     

Abnormal angiogenesis in Foxo1 (Fkhr)-deficient mice

Members of the Foxo family, Foxo1 (Fkhr), Foxo3 (Fkhrl1), and Foxo4 (Afx), are mammalian homologs of daf-16, which influences life span and energy metabolism in Caenorhabditis elegans. Mammalian FOXO proteins also play important roles in cell cycle arrest, apoptosis, stress resistance, and energy metabolism. In this study, we generated Foxo1-deficient mice to investigate the physiological role of FOXO1. The Foxo1-deficient mice died around embryonic day 11 because of defects in the branchial arches and remarkably impaired vascular development of embryos and yolk sacs. In vitro differentiation of embryonic stem cells demonstrated that endothelial cells derived from wild-type and Foxo1-deficient embryonic stem cells were able to produce comparable numbers of colonies supported by a layer of OP9 stromal cells. Although the morphology of the endothelial cell colonies was identical in both genotypes in the absence of exogenous vascular endothelial growth factor (VEGF), Foxo1-deficient endothelial cells showed a markedly different morphological response compared with wild-type endothelial cells in the presence of exogenous VEGF. These results suggest that Foxo1 is essential to the ability of endothelial cells to respond properly to a high dose of VEGF, thereby playing a critical role in normal vascular development.     

Inhibition of Quorum Sensing in Serratia marcescens AS-1 by Synthetic Analogs of N-Acylhomoserine Lactone

Quorum sensing is a regulatory system for controlling gene expression in response to increasing cell density. N-Acylhomoserine lactone (AHL) is produced by gram-negative bacteria, which use it as a quorum-sensing signal molecule. Serratia marcescens is a gram-negative opportunistic pathogen which is responsible for an increasing number of serious nosocomial infections. S. marcescens AS-1 produces N-hexanoyl homoserine lactone (C₆-HSL) and N-(3-oxohexanoyl) homoserine lactone and regulates prodigiosin production, swarming motility, and biofilm formation by AHL-mediated quorum sensing. We synthesized a series of N-acyl cyclopentylamides with acyl chain lengths ranging from 4 to 12 and estimated their inhibitory effects on prodigiosin production in AS-1. One of these molecules, N-nonanoyl-cyclopentylamide (C₉-CPA), had a strong inhibitory effect on prodigiosin production. C₉-CPA also inhibited the swarming motility and biofilm formation of AS-1. A competition assay revealed that C₉-CPA was able to inhibit quorum sensing at four times the concentration of exogenous C₆-HSL and was more effective than the previously reported halogenated furanone. Our results demonstrated that C₉-CPA was an effective quorum-sensing inhibitor for S. marcescens AS-1.     

Establishment and characterization of a noradrenergic adrenal chromaffin cell line, tsAM5NE, immortalized with the temperature-sensitive SV40 T-antigen

We established a clonal adrenal medullary cell line, named tsAM5NE, from transgenic mice harbouring the temperature-sensitive Simian virus 40 large T-antigen gene, under the control of the tyrosine hydroxylase promoter. tsAM5NE cells conditionally grew at a permissive temperature of 33°C and exhibited the noradrenergic chromaffin cell phenotype. To understand the characteristics of tsAM5NE cells, we first examined the responsiveness of the cells to ligands of the GDNF (glial cell line-derived neurotrophic factor) family. tsAM5NE cells proliferated at the permissive temperature of 33°C in response to either GDNF or neurturin, but not artemin or persephin. At the non-permissive temperature of 39°C, GDNF or neurturin caused tsAM5NE cells to differentiate into neuron-like cells; however, the differentiated cells died in a time-dependent manner. Interestingly, LIF (leukaemia inhibitory factor) did not affect the GDNF-mediated cell proliferation at 33°C, but promoted the survival and differentiation of GDNF-treated cells at 39°C. In the presence of GDNF plus LIF, the morphological change induced by the temperature shift was associated with up-regulated expression of neuronal markers, indicating that the cells had indeed undergone neuronal differentiation. Thus, we demonstrated that tsAM5NE cells had the capacity to terminally differentiate into neuron-like cells in response to GDNF plus LIF when the oncogene was inactivated by the temperature shift. Thus, this cell line provides a useful model system for studying the mechanisms regulating neuronal differentiation.     

W14/15 esterase gene haplotype can be a genetic landmark of cultivars and species of the genus <Emphasis Type="Italic">Gentiana</Emphasis> L

We have identified multiple alleles for a single gene termed W14/15. This gene encodes closely related but not identical proteins W14 and W15 that accumulate in overwinter buds of Gentiana triflora (Takahashi et al. in Breed Sci 56:39–46, 2006; Hikage et al. in Mol Genet Genomics 278:95–104, 2007). In this study, structural analysis of the W14/15 gene was carried out for 21 different gentian lines/cultivars consisting of 5 different species, to survey species- or line/cultivar-specific haplotypes. Within the samples examined, multiple variant forms were found. Those were categorized into seven major types (type I–VII) and ten subtypes based on the presence of three short insertion/deletion sites, three RFLP sites, and several SNP sites. Each line/cultivar had a distinct set of W14/15 gene variants for an allelic pair. Phylogenetic analysis showed that the W14/15 alleles cluster into groups that are characteristic of gentian species, i.e., G. triflora, G. scabra, G. pneumonanthe, G. septemfida and an unknown species other than the former four. In addition, within the same gentian species, different sets of haplotypes were found. Thus, the W14/15 alleles provide useful landmarks to resolve phylogenies of the genus or section Gentiana, as well as to analyze pedigree and breeding history of the cultivars derived from those Gentiana sp.     

Linkage Replication for Chromosomal Region 13q32 in Schizophrenia: Evidence from a Brazilian Pilot Study on Early Onset Schizophrenia Families

We report analyses of a Brazilian study of early onset schizophrenia (BEOS) families. We genotyped 22 members of 4 families on a linkage SNP array and report here non-parametric linkage analyses using MERLIN® software. We found suggestive evidence for linkage on two chromosomal regions, 13q32 and 11p15.4. A LOD score of 2.71 was observed at 13q32 with a one LOD interval extending from 60.63–92.35 cM. From simulations, this LOD score gave a genome-wide empirical corrected p = 0.33, after accounting for all markers tested. Similarly 11p15.4 showed the same maximum LOD of 2.71 and a narrower one LOD interval of 4–14 cM. Of these, 13q32 has been reported to be linked to schizophrenia by multiple different studies. Thus, our study provides additional supporting evidence for an aetiological role of variants at 13q32 in schizophrenia.     

Alternation of extracellular matrix remodeling and apoptosis by activation of the aryl hydrocarbon receptor pathway in human periodontal ligament cells

It is well known that the aryl hydrocarbon receptor (AhR) is involved in the toxicity of halogenated aromatic hydrocarbons (HAH) and polycyclic aromatic hydrocarbons (PAH). Recent experiments have shown the induction of impaired tooth and hard‐tissue formation by AhR pathway activation, however, the effect on periodontal ligament (PDL) tissue remains unclear. Here, we investigated the effects of benzo(a)pyrene (BaP), a member of PAH, on the extracellular matrix (ECM) remodeling‐related molecules, collagen type I (COL‐I), matrix metalloproteinase‐1 (MMP‐1), alpha‐smooth muscle actin (α‐SMA) expression, and apoptosis in two different human periodontal ligament cells (HPDLCs). The transduction of AhR from the cytoplasm to the nucleus and the increase of AhR‐responsive genes; that is, cytochrome P450 1A1 (CYP1A1), cytochrome P450 1B1 (CYP1B1), and aryl‐hydrocarbon receptor repressor (AhRR), expression was induced by BaP exposure in both HPDLCs. BaP treatment significantly enhanced MMP‐1 mRNA expression and MMP‐1 protein production, while markedly suppressing COL‐I and a‐SMA mRNA expression in both HPDLCs. Furthermore, these BaP‐treated HPDLCs fell into apoptotic cell death as evidenced by induction in annexin V and caspase‐3/7 staining and reduction of total cell number and Bcl‐2 mRNA expression. Thus, BaP exposure altered the expression of ECM‐related molecules and induced apoptosis in HPDLCs through activation of the AhR pathway. Overactivity of the AhR pathway may induce an inappropriate turnover of PDL tissue via disordered ECM remodeling and apoptosis in PDL cells. J. Cell. Biochem. 113: 3093–3103, 2012. © 2012 Wiley Periodicals, Inc.     

Karyological characterization of meiosis, post-meiotic mitosis and nuclear migration in the ectomycorrhizal fungus Rhizopogon roseolus (= R. rubescens)

Karyological characteristics during basidiosporogenesis of Rhizopogon roseolus, a member of the hypogeous Agaricomycetes, were studied by light and transmission electron microscopy. More than 1000 tissue fragments of young basidiomata were stained with HCl-Giemsa and observed by a light microscopy to evaluate nuclear behavior. Basidium morphology in the hymenium was observed by transmission electron microscopy. Meiosis and post-meiotic mitosis took place in the center of the basidium. Sterigmata appeared when the first meiotic division occurred, and the center of the basidium became constricted when the second meiotic division occurred. Asynchronous nuclear migration from the basidium into the basidiospores occurred after post-meiotic mitosis, producing eight uninucleate basidiospores. The nucleus migrated patchily into basidiospores. The pattern of post-meiotic mitosis of R. roseolus, in which post-meiotic mitosis took place in the center of the basidium, is reported for the first time.