Lung damage in mice after inhalation of nanofilm spray products: The role of perfluorination and free hydroxyl groups. Nørgaard AW, Larsen ST, Hammer M, Poulsen SS, Jensen KA, Nielsen GD, Wolkoff P Toxicol Sci
2010
Show Abstract
Exposures to two commercial nanofilm spray products (NFPs), a floor sealant (NFP 1) and a coating product for tiles (NFP 2), were investigated for airway irritation, airway inflammation and lung damage in a mouse inhalation model. The particle-exposure was characterized by particle number, particle size-distribution and gravimetric analysis. BALB/cJ mice were exposed for 60 min to the aerosolized products at 3.3-60 mg/m(3) (10(5) - 10(6) fine particles/cm(3)) measured in the breathing zone of the mice. Lung inflammation and lung damage were assessed by study of bronchoalveolar lavage fluid (BALF) cytology, protein in BALF and histology. Mass spectral analysis showed that NFP 1 and NFP 2 contained hydrolysates and condensates of a perfluorosilane and alkylsilane, respectively. NFP 1 induced a concentration-dependent decrease of the tidal volume lasting for at least one day. Exposure concentrations above 16.1 mg/m(3) (2.5x10(6) fine particles/cm(3)) gave rise to significant increases of protein level in BALF, reduced body weight, and histological examination showed atelectasis, emphysema and hemorrhages. A narrow interval between the no-effect level (16.1 mg/m(3)) and lethal concentrations (18.4 mg/m(3)) was observed. The alkylsilane based product (NFP 2) had no effect at the concentrations studied. Experiments with different types of perfluorinated silanes and siloxanes showed that the toxic effects did not arise solely from the perfluorination. The number of free hydroxyl groups in the silanes/siloxanes was also critical for the toxicity. | 20348230
 |
Gene expression profiling-based identification of molecular subtypes in stage IV melanomas with different clinical outcome. Jönsson G, Busch C, Knappskog S, Geisler J, Miletic H, Ringnér M, Lillehaug JR, Borg A, Lønning PE Clin Cancer Res
16
3356-67. Epub 2010 May 11.
2010
Show Abstract
PURPOSE: The incidence of malignant melanoma is increasing worldwide in fair-skinned populations. Melanomas respond poorly to systemic therapy, and metastatic melanomas inevitably become fatal. Although spontaneous regression, likely due to immune defense activation, rarely occurs, we lack a biological rationale and predictive markers in selecting patients for immune therapy. EXPERIMENTAL DESIGN: We performed unsupervised hierarchical clustering of global gene expression data from stage IV melanomas in 57 patients. For further characterization, we used immunohistochemistry of selected markers, genome-wide DNA copy number analysis, genetic and epigenetic analysis of the CDKN2A locus, and NRAS/BRAF mutation screening. RESULTS: The analysis revealed four distinct subtypes with gene signatures characterized by expression of immune response, pigmentation differentiation, proliferation, or stromal composition genes. Although all subtypes harbored NRAS and BRAF mutations, there was a significant difference between subtypes (P < 0.01), with no BRAF/NRAS wild-type samples in the proliferative subtype. Additionally, the proliferative subtype was characterized by a high frequency of CDKN2A homozygous deletions (P < 0.01). We observed a different prognosis between the subtypes (P = 0.01), with a particularly poor survival for patients harboring tumors of the proliferative subtype compared with the others (P = 0.003). Importantly, the clinical relevance of the subtypes was validated in an independent cohort of 44 stage III and IV melanomas. Moreover, low expression of an a priori defined gene set associated with immune response signaling was significantly associated with poor outcome (P = 0.001). CONCLUSIONS: Our data reveal a biologically based taxonomy of malignant melanomas with prognostic effect and support an influence of the antitumoral immune response on outcome. | 20460471
 |
Paraoxonase-3, a Putative Circulating Antioxidant, Is Systemically Up-Regulated in Late Gestation in the Fetal Rat, Sheep, and Human. Belteki G, Kempster SL, Forhead AJ, Giussani DA, Fowden AL, Curley A, Charnock-Jones DS, Smith GC J Clin Endocrinol Metab
2010
Show Abstract
Context: Surfactant is a successful therapeutic based on supplementing preterm infants with a substance that would normally have been up-regulated in late gestation. Although prematurity is associated with oxidative stress, no effective antioxidant therapy has yet been identified. Objective: Our objective was to identify endogenous antioxidants involved in fetal preparation for birth. Design: We performed transcript profiling of fetal rat lung and intestine at 16 d gestational age (dGA) and 20 dGA with out-of-sample validation. Gene expression was then measured in fetal sheep tissues, comparing 1) advancing GA, 2) exogenous maternal dexamethasone (compared with saline, at 130 dGA), and 3) fetal adrenalectomy at 115-118 d on levels at term. Protein levels were compared in human umbilical cord serum using Western blot. Results: Four transcripts were up-regulated more than 20-fold on the array in both rat lung and intestine. One of these, paraoxonase-3 (Pon3), had been identified as a putative circulating antioxidant. Up-regulation of Pon3 mRNA in rat lung, intestine, and liver was confirmed in siblings (all P < 0.001). Pon3 mRNA levels in fetal sheep lung and intestine increased 5.1- and 5.3-fold, respectively (both P < 0.001) between 100 and 145 dGA and were strongly correlated with plasma cortisol (both P < 0.001). Fetal sheep pulmonary Pon3 transcript level was increased 55% (P = 0.01) by dexamethasone and reduced 74% (P < 0.001) by adrenalectomy. Term human infants had more than 6-fold higher umbilical cord serum levels of Pon3 than preterm (24-28 wk GA) infants (P < 0.001). Conclusions: Pon3, a putative circulating antioxidant, was systemically up-regulated in late-gestation rat, sheep, and human fetuses and is a candidate therapeutic in preterm human infants. | 20463093
 |
Impairment of PGC-1alpha expression, Neuropathology and Hepatic Steatosis in a transgenic mouse model of Huntington's disease following chronic energy deprivation. Chaturvedi RK, Calingasan NY, Yang L, Hennessey T, Johri A, Beal MF Hum Mol Genet
2010
Show Abstract
We investigated the ability of AMP-activated protein kinase (AMPK) to activate PPARgamma coactivator-1alpha (PGC-1alpha) in the brain, liver and brown adipose tissue (BAT) of the NLS-N171-82Q transgenic mouse model of Huntington's Disease (HD). In the striatum of the HD mice, the baseline levels of PGC-1alpha, NRF1, NRF2, Tfam, COX-II, PPARdelta, CREB and ERRalpha mRNA, and mitochondrial DNA (mtDNA), were significantly reduced. Administration of the creatine analog beta guanidinopropionic acid (GPA), reduced ATP and PCr levels, and increased AMPK mRNA in both the cerebral cortex and striatum. Treatment with GPA significantly increased expression of PGC-1alpha, NRF1, Tfam, and downstream genes in the striatum and cerebral cortex of wildtype (WT) mice, but there was no effect on these genes in the HD mice. The striatum of the untreated HD mice showed microvacuolation in the neuropil, as well as gliosis and huntingtin aggregates, which were exacerbated by treatment with GPA. GPA treatment produced a significant increase in mtDNA in the cerebral cortex and striatum of WT mice, but not in HD mice. The HD mice treated with GPA had impaired activation of liver PGC-1alpha, and developed hepatic steatosis with accumulation of lipids, degeneration of hepatocytes, and impaired activation of gluconeogenesis. The BAT in the HD mice showed vacuolation due to accumulation of neutral lipids, and age-dependent impairment of UCP-1 activation and temperature regulation. Impaired activation of PGC-1alpha, therefore plays an important role in the behavioral phenotype, metabolic disturbances, and pathology of HD, which suggests the possibility that agents which enhance PGC-1alpha function, will exert therapeutic benefits in HD patients. | 20529956
 |
Natronorubrum sediminis sp. nov., an archaeon isolated from a saline lake. Gutiérrez MC, Castillo AM, Corral P, Minegishi H, Ventosa A Int J Syst Evol Microbiol
60
1802-6. Epub 2009 Sep 18.
2010
Show Abstract
Two novel haloalkaliphilic archaea, strains CG-6(T) and CG-4, were isolated from sediment of the hypersaline Lake Chagannor in Inner Mongolia, China. Cells of the two strains were pleomorphic, non-motile and strictly aerobic. They required at least 2.5 M NaCl for growth, with optimum growth at 3.4 M NaCl. They grew at pH 8.0-11.0, with optimum growth at pH 9.0. Hypotonic treatment with less than 1.5 M NaCl caused cell lysis. The two strains had similar polar lipid compositions, possessing C(20)C(20) and C(20)C(25) derivatives of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. No glycolipids were detected. Comparison of 16S rRNA gene sequences and morphological features placed them in the genus Natronorubrum. 16S rRNA gene sequence similarities to strains of recognized species of the genus Natronorubrum were 96.2-93.8 %. Detailed phenotypic characterization and DNA-DNA hybridization studies revealed that the two strains belong to a novel species in the genus Natronorubrum, for which the name Natronorubrum sediminis sp. nov. is proposed; the type strain is CG-6(T) (=CECT 7487(T) =CGMCC 1.8981(T) =JCM 15982(T)). | 19767366
 |
Quantitative profiling of the full APOBEC3 mRNA repertoire in lymphocytes and tissues: implications for HIV-1 restriction. Refsland EW, Stenglein MD, Shindo K, Albin JS, Brown WL, Harris RS Nucleic Acids Res
2010
Show Abstract
The human APOBEC3 proteins are DNA cytidine deaminases that impede the replication of many different transposons and viruses. The genes that encode APOBEC3A, APOBEC3B, APOBEC3C, APOBEC3D, APOBEC3F, APOBEC3G and APOBEC3H were generated through relatively recent recombination events. The resulting high degree of inter-relatedness has complicated the development of specific quantitative PCR assays for these genes despite considerable interest in understanding their expression profiles. Here, we describe a set of quantitative PCR assays that specifically measures the mRNA levels of each APOBEC3 gene. The specificity and sensitivity of each assay was validated using a full matrix of APOBEC3 cDNA templates. The assays were used to quantify the APOBEC3 repertoire in multiple human T-cell lines, bulk leukocytes and leukocyte subsets, and 20 different human tissues. The data demonstrate that multiple APOBEC3 genes are expressed constitutively in most types of cells and tissues, and that distinct APOBEC3 genes are induced upon T-cell activation and interferon treatment. These data help define the APOBEC3 repertoire relevant to HIV-1 restriction in T cells, and they suggest a general model in which multiple APOBEC3 proteins function together to provide a constitutive barrier to foreign genetic elements, which can be fortified by transcriptional induction. | 20308164
 |
Dendritic cell nuclear protein-1, a novel depression-related protein, upregulates corticotropin-releasing hormone expression. Zhou T, Wang S, Ren H, Qi XR, Luchetti S, Kamphuis W, Zhou JN, Wang G, Swaab DF Brain
2010
Show Abstract
The recently discovered dendritic cell nuclear protein-1 is the product of a novel candidate gene for major depression. The A allele encodes full-length dendritic cell nuclear protein-1, while the T allele encodes a premature termination of translation at codon number 117 on chromosome 5. In the present study we investigate whether the two forms of dendritic cell nuclear protein-1 might act on corticotropin-releasing hormone, which plays a crucial role in the stress response and in the pathogenesis of depression. The messenger RNA expression of dendritic cell nuclear protein-1 appeared to be increased in the laser micro-dissected paraventricular nucleus of patients with depression compared with control subjects. Dendritic cell nuclear protein-1 was also found to be co-localized with corticotropin-releasing hormone in paraventricular nucleus neurons. Moreover, full-length dendritic cell nucleus protein-1 bound to and transactivated the promoter of corticotropin-releasing hormone in human embryonic kidney 293 cells. We propose that full-length dendritic cell nucleus protein-1 may play a role in the pathogenesis of depressive disorders by enhancing corticotropin-releasing hormone expression in the hypothalamic paraventricular nucleus. | 20693543
 |
Sucrose nonfermenting AMPK-related kinase (SNARK) mediates contraction-stimulated glucose transport in mouse skeletal muscle. Koh HJ, Toyoda T, Fujii N, Jung MM, Rathod A, Middelbeek RJ, Lessard SJ, Treebak JT, Tsuchihara K, Esumi H, Richter EA, Wojtaszewski JF, Hirshman MF, Goodyear LJ Proc Natl Acad Sci U S A
2010
Show Abstract
The signaling mechanisms that mediate the important effects of contraction to increase glucose transport in skeletal muscle are not well understood, but are known to occur through an insulin-independent mechanism. Muscle-specific knockout of LKB1, an upstream kinase for AMPK and AMPK-related protein kinases, significantly inhibited contraction-stimulated glucose transport. This finding, in conjunction with previous studies of ablated AMPKalpha2 activity showing no effect on contraction-stimulated glucose transport, suggests that one or more AMPK-related protein kinases are important for this process. Muscle contraction increased sucrose nonfermenting AMPK-related kinase (SNARK) activity, an effect blunted in the muscle-specific LKB1 knockout mice. Expression of a mutant SNARK in mouse tibialis anterior muscle impaired contraction-stimulated, but not insulin-stimulated, glucose transport. Whole-body SNARK heterozygotic knockout mice also had impaired contraction-stimulated glucose transport in skeletal muscle, and knockdown of SNARK in C2C12 muscle cells impaired sorbitol-stimulated glucose transport. SNARK is activated by muscle contraction and is a unique mediator of contraction-stimulated glucose transport in skeletal muscle. | 20713714
 |
Tbr1 regulates regional and laminar identity of postmitotic neurons in developing neocortex. Bedogni F, Hodge RD, Elsen GE, Nelson BR, Daza RA, Beyer RP, Bammler TK, Rubenstein JL, Hevner RF Proc Natl Acad Sci U S A
107
13129-34. Epub 2010 Jul 6.
2010
Show Abstract
Areas and layers of the cerebral cortex are specified by genetic programs that are initiated in progenitor cells and then, implemented in postmitotic neurons. Here, we report that Tbr1, a transcription factor expressed in postmitotic projection neurons, exerts positive and negative control over both regional (areal) and laminar identity. Tbr1 null mice exhibited profound defects of frontal cortex and layer 6 differentiation, as indicated by down-regulation of gene-expression markers such as Bcl6 and Cdh9. Conversely, genes that implement caudal cortex and layer 5 identity, such as Bhlhb5 and Fezf2, were up-regulated in Tbr1 mutants. Tbr1 implements frontal identity in part by direct promoter binding and activation of Auts2, a frontal cortex gene implicated in autism. Tbr1 regulates laminar identity in part by downstream activation or maintenance of Sox5, an important transcription factor controlling neuronal migration and corticofugal axon projections. Similar to Sox5 mutants, Tbr1 mutants exhibit ectopic axon projections to the hypothalamus and cerebral peduncle. Together, our findings show that Tbr1 coordinately regulates regional and laminar identity of postmitotic cortical neurons. Full Text Article | 20615956
 |
Interneurons of the cerebellar cortex toggle Purkinje cells between up and down states. Oldfield CS, Marty A, Stell BM Proc Natl Acad Sci U S A
107
13153-8. Epub 2010 Jul 6.
2010
Show Abstract
We demonstrate that single interneurons can toggle the output neurons of the cerebellar cortex (the Purkinje cells) between their two states. The firing of Purkinje cells has previously been shown to alternate between an "up" state in which the cell fires spontaneous action potentials and a silent "down" state. We show here that small hyperpolarizing currents in Purkinje cells can bidirectionally toggle Purkinje cells between down and up states and that blockade of the hyperpolarization-activated cation channels (H channels) with the specific antagonist ZD7288 (10 microM) blocks the transitions from down to up states. Likewise, hyperpolarizing inhibitory postsnyaptic potentials (IPSPs) produced by small bursts of action potentials (10 action potentials at 50 Hz) in molecular-layer interneurons induce these bidirectional transitions in Purkinje cells. Furthermore, single interneurons in paired interneuron --> Purkinje cell recordings, produce bidirectional switches between the two states of Purkinje cells. The ability of molecular-layer interneurons to toggle Purkinje cells occurs when Purkinje cells are recorded under whole-cell patch-clamp conditions as well as when action potentials are recorded in an extracellular loose cell-attached configuration. The mode switch demonstrated here indicates that a single presynaptic interneuron can have opposite effects on the output of a given Purkinje cell, which introduces a unique type of synaptic interaction that may play an important role in cerebellar signaling. Full Text Article | 20615960
 |