5A apolipoprotein mimetic peptide promotes cholesterol efflux and reduces atherosclerosis in mice. Amar MJ, D'Souza W, Turner S, Demosky S, Sviridov D, Stonik J, Luchoomun J, Voogt J, Hellerstein M, Sviridov D, Remaley AT J Pharmacol Exp Ther
334
634-41. Epub 2010 May 19.
2010
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Intravenous administration of apolipoprotein (apo) A-I complexed with phospholipid has been shown to rapidly reduce plaque size in both animal models and humans. Short synthetic amphipathic peptides can mimic the antiatherogenic properties of apoA-I and have been proposed as alternative therapeutic agents. In this study, we investigated the atheroprotective effect of the 5A peptide, a bihelical amphipathic peptide that specifically effluxes cholesterol from cells by ATP-binding cassette transporter 1 (ABCA1). 5A stimulated a 3.5-fold increase in ABCA1-mediated efflux from cells and an additional 2.5-fold increase after complexing it with phospholipid (1:7 mol/mol). 5A-palmitoyl oleoyl phosphatidyl choline (POPC), but not free 5A, was also found to promote cholesterol efflux by ABCG1. When incubated with human serum, 5A-POPC bound primarily to high-density lipoprotein (HDL) but also to low-density lipoprotein (LDL) and promoted the transfer of cholesterol from LDL to HDL. Twenty-four hours after intravenous injection of 5A-POPC (30 mg/kg) into apoE-knockout (KO) mice, both the cholesterol (181%) and phospholipid (219%) content of HDL significantly increased. By an in vivo cholesterol isotope dilution study and monitoring of the flux of cholesterol from radiolabeled macrophages to stool, 5A-POPC treatment was observed to increase reverse cholesterol transport. In three separate studies, 5A when complexed with various phospholipids reduced aortic plaque surface area by 29 to 53% (n = 8 per group; p < 0.02) in apoE-KO mice. No signs of toxicity from the treatment were observed during these studies. In summary, 5A promotes cholesterol efflux both in vitro and in vivo and reduces atherosclerosis in apoE-KO mice, indicating that it may be a useful alternative to apoA-I for HDL therapy. Full Text Article | 20484557
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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Mitochondrial GLUT10 facilitates dehydroascorbic acid import and protects cells against oxidative stress: mechanistic insight into arterial tortuosity syndrome. Lee YC, Huang HY, Chang CJ, Cheng CH, Chen YT Hum Mol Genet
2010
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Mutations in glucose transporter 10 (GLUT10) alter angiogenesis and cause arterial tortuosity syndrome (ATS); however, the mechanisms by which these mutations cause disease remain unclear. It has been reported that in most cells, mitochondria are the major source of reactive oxygen species (ROS). Moreover, mitochondria are known to incorporate as well as recycle vitamin C, which plays a critical role in redox homeostasis, although the molecular mechanism(s) underlying mitochondrial vitamin C uptake are poorly understood. We report here that GLUT10 localizes predominantly to the mitochondria of smooth muscle cells and insulin-stimulated adipocytes, where GLUT10 is highly expressed. We further demonstrate that GLUT10 facilitates transport of l-dehydroascorbic acid (DHA), the oxidized form of vitamin C, into mitochondria, and also increases cellular uptake of DHA, which in turn protects cells against oxidative stress. This protection is compromised when GLUT10 expression in mitochondria is inhibited. In addition, we found that aortic smooth muscle cells from GLUT10-mutant mice have higher ROS levels than those from wild-type mice. Our results identify the physiological role of GLUT10 as the mitochondrial DHA transporter, and demonstrate that GLUT10 protects cells from oxidative injury. Furthermore, our findings provide a mechanism to explain the ascorbate in mitochondria and show how loss-of-function GLUT10 mutations may lead to arterial abnormalities in ATS. These results also reinforce the importance of vitamin C and ROS in degenerative diseases. | 20639396
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T-cell phenotype in protocol renal biopsy from transplant recipients treated with Belatacept-mediated co-stimulatory blockade. Grimbert P, Audard V, Diet C, Matignon M, Plonquet A, Mansour H, Desvaux D, Durrbach A, Cohen JL, Lang P Nephrol Dial Transplant
2010
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BACKGROUND: Belatacept is thought to disrupt the interaction between CD80/86 and CD28, thus preventing T-cell activation by blocking the co-stimulatory second signal. However, the consequences on the T-cell profile in human renal transplant cases have not been determined. | 20667993
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Exposure to bioaerosols during the growth season in an organic greenhouse tomato production using Supresivit(R) (Trichoderma harzianum) and Mycostop(R) (Streptomyces griseoviridis). Hansen VM, Winding A, Madsen AM Appl Environ Microbiol
2010
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In working environments, especially in confined spaces like greenhouses, elevated concentrations of airborne microorganisms may become a problem for workers' health. Additionally, the use of microbial pest control agents may increase exposure to microorganisms. The aim of this study was to investigate tomato growers' exposure to naturally occurring bioaerosol components (dust, bacteria, fungi, actinomycetes, (1-->3)-beta-D-glucans and endotoxin) and microbial pest control agents applied by drip irrigation. Airborne dust was collected with filter samplers and analyzed for microorganisms by plate counts and total counts in microscope. Analysis of (1-->3)-beta-D-glucan and endotoxin content were performed by kinetic, chromatic Limulus Amoebocyte Lysate tests. The fungal strain (Trichoderma harzianum) from the biocontrol product Supresivit(R) was identified by PCR analysis. Measurements were performed on the day of drip irrigation and one week, one month and three months after the irrigation. T. harzianum from Supresivit(R) could only be detected on the day of treatment. Streptomyces griseoviridis, an applied microbial pest control agent, was not detected in the air during this investigation. We found that bioaerosol exposure increases during the growth season and that exposure to fungi, bacteria, and endotoxin can reach levels during the harvest period, that may cause respiratory symptoms in growers. The collected data indicates that MPCAs applied by drip irrigation do not become airborne later in the season. | 20622135
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