CSF Proteomics Identifies Specific and Shared Pathways for Multiple Sclerosis Clinical Subtypes

Multiple sclerosis (MS) is an immune-mediated, neuro-inflammatory, demyelinating and neurodegenerative disease of the central nervous system (CNS) with a heterogeneous clinical presentation and course. There is a remarkable phenotypic heterogeneity in MS, and the molecular mechanisms underlying it remain unknown. We aimed to investigate further the etiopathogenesis related molecular pathways in subclinical types of MS using proteomic and bioinformatics approaches in cerebrospinal fluids of patients with clinically isolated syndrome, relapsing remitting MS and progressive MS (n=179). Comparison of disease groups with controls revealed a total of 151 proteins that are differentially expressed in clinically different MS subtypes. KEGG analysis using PANOGA tool revealed the disease related pathways including aldosterone-regulated sodium reabsorption (p=8.02x10^-5) which is important in the immune cell migration, renin-angiotensin (p=6.88x10^-5) system that induces Th17 dependent immunity, notch signaling (p=1.83x10^-10) pathway indicating the activated remyelination and vitamin digestion and absorption pathways (p=1.73x10^-5). An emerging theme from our studies is that whilst all MS clinical forms share common biological pathways, there are also clinical subtypes specific and pathophysiology related pathways which may have further therapeutic implications.     

The viability of a plant “on the edge”: Glaucium flavum (Papaveraceae) in Norway

The prospects for persistence of Glaucium flavum in Norway were evaluated by integrating data concerning spatio‐temporal distribution, plant growth and development, reproduction, dispersal, seed bank and genetic variability. The distribution of Glaucium flavum in the Oslo Fjord region is much more restricted now than before. Out of the formerly recorded 35 populations, only eight populations were present in 1998, all in the outer parts of the fjord. The species is a short‐lived iteroparous perennial in Norway. This growth habit gives high reproductive output from fertile individuals. G. flavum is self‐compatible and can easily reproduce even in small populations. The ability to disperse long distances on water is limited. The observed seed bank will therefore enhance survival. No variation in isoenzymes was observed neither within nor among the G. flavum populations in the Oslo Fjord region. The species should be considered Endangered in Norway, according to the criteria given by IUCN.     

The RGD Domain of Human Osteopontin Promotes Tumor Growth and Metastasis through Activation of Survival Pathways

Background

Human osteopontin (OPN), a known tumor associated protein, exists in different isoforms, whose function is unclear. It also possesses a RGD domain, which has been implicated in diverse function. Here, we use genetic approaches to systematically investigate the function of the RGD domain in different OPN isoforms on tumor progression and metastasis for 2 different solid tumor models.

Methodology/Principal Findings

Using isoform-specific qRT-PCR, we found that OPN-A and B were the main isoforms overexpressed in evaluated human tumors, which included 4 soft tissue sarcomas, 24 lung and 30 head and neck carcinomas. Overexpression of either OPN-A or B in two different cell types promoted local tumor growth and lung metastasis in SCID mouse xenografts. However, expression of either isoform with the RGD domain either mutated or deleted decreased tumor growth and metastasis, and resulted in increased apoptosis by TUNEL staining. In vitro, whereas mutation of the RGD domain did not affect cell-cell adhesion, soft agar growth or cell migration, it increased apoptosis under hypoxia and serum starvation. This effect could be mitigated when the RGD mutant cells were treated with condition media containing WT OPN. Mechanistically, the RGD region of OPN inhibited apoptosis by inducing NF-κB activation and FAK phosphorylation. Inhibition of NF-κB (by siRNA to the p65 subunit) or FAK activation (by a inhibitor) significantly increased apoptosis under hypoxia in WT OPN cells, but not in RGD mutant cells.

Conclusion/Significance

Unlike prior reports, our data suggest that the RGD domain of both OPN-A and B promote tumor growth and metastasis mainly by protecting cells against apoptosis under stressed conditions and not via migration or invasion. Future inhibitors directed against OPN should target multiple isoforms and should inhibit cell survival mechanisms that involve the RGD domain, FAK phosphorylation and NF-κB activation.     

Candida utilis and Chlorella vulgaris Counteract Intestinal Inflammation in Atlantic Salmon (Salmo salar L.)

Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM) in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE). In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation. The dietary treatments consisted of a negative control based on fish meal (FM), a positive control based on 20% SBM, and four experimental diets combining 20% SBM with either one of the three yeasts Candida utilis (CU), Kluyveromyces marxianus (KM), Saccharomyces cerevisiae (SC) or the microalgae Chlorella vulgaris (CV). Histopathological examination of the distal intestine showed that all fish fed the SC or SBM diets developed characteristic signs of SBMIE, while those fed the FM, CV or CU diets showed a healthy intestine. Fish fed the KM diet showed intermediate signs of SBMIE. Corroborating results were obtained when measuring the relative length of PCNA positive cells in the crypts of the distal intestine. Gene set enrichment analysis revealed decreased expression of amino acid, fat and drug metabolism pathways as well as increased expression of the pathways for NOD-like receptor signalling and chemokine signalling in both the SC and SBM groups while CV and CU were similar to FM and KM was intermediate. Gene expression of antimicrobial peptides was reduced in the groups showing SBMIE. The characterisation of microbial communities using PCR-DGGE showed a relative increased abundance of Firmicutes bacteria in fish fed the SC or SBM diets. Overall, our results show that both CU and CV were highly effective to counteract SBMIE, while KM had less effect and SC had no functional effects.     

Pulsed IR Heating Studies of Single-Molecule DNA Duplex Dissociation Kinetics and Thermodynamics

Single-molecule fluorescence spectroscopy is a powerful technique that makes it possible to observe the conformational dynamics associated with biomolecular processes. The addition of precise temperature control to these experiments can yield valuable thermodynamic information about equilibrium and kinetic rate constants. To accomplish this, we have developed a microscopy technique based on infrared laser overtone/combination band absorption to heat small (≈10⁻¹¹ liter) volumes of water. Detailed experimental characterization of this technique reveals three major advantages over conventional stage heating methods: 1), a larger range of steady-state temperatures (20–100°C); 2), substantially superior spatial (≤20 μm) control; and 3), substantially superior temporal (≈1 ms) control. The flexibility and breadth of this spatial and temporally resolved laser-heating approach is demonstrated in single-molecule fluorescence assays designed to probe the dissociation of a 21 bp DNA duplex. These studies are used to support a kinetic model based on nucleic acid end fraying that describes dissociation for both short (<10 bp) and long (>10 bp) DNA duplexes. These measurements have been extended to explore temperature-dependent kinetics for the 21 bp construct, which permit determination of single-molecule activation enthalpies and entropies for DNA duplex dissociation.     

Influence of medium and cold pretreatment on androgenetic response in Lolium perenne L.

Summary Genotypes of Lolium perenne L. with different androgenetic responses were used to test effects of induction medium composition. The media tested were potato II (pII), 190-2, and modified Linsmaier and Skoog media, LS-1, LS-2, and LS-3. The effect of different gelling agents, activated charcoal in a double layer design, and casein hydrolysate were also studied. From 36,696 anthers, 25,906 embryo-like structures, 1,959 albino and 173 green plants were generated. Significant differences were found between media, genotypes and medium-genotype interactions studied. All three media commonly used, pII, 190-2, and LS-3, were equivalent in production of green plants. Cold pretreatment of the anthers (4°C) significantly increased the number of embryo-like structures, the number and proportion of albino plants produced, but not the production of green plants.Abbreviations ELS embryo-like structures - ALB albino plants - ANT anthers - GRP green plants - DH doubled haploid plants - AC activated charcoal - CH casein hydrolysate - 2,4-D 2,4-dichlorophenoxyacetic acid - LS Linsmaier and Skoog (1965) basal medium - MS Murashige and Skoog (1962) - PL plants - pII potato II induction medium - DL double layer     

Human Naa50p (Nat5/San) Displays Both Protein Nα- and N?-Acetyltransferase Activity

Protein acetylation is a widespread modification that is mediated by site-selective acetyltransferases. KATs (lysine N^ϵ-acetyltransferases), modify the side chain of specific lysines on histones and other proteins, a central process in regulating gene expression. N^α-terminal acetylation occurs on the ribosome where the α amino group of nascent polypeptides is acetylated by NATs (N-terminal acetyltransferase). In yeast, three different NAT complexes were identified NatA, NatB, and NatC. NatA is composed of two main subunits, the catalytic subunit Naa10p (Ard1p) and Naa15p (Nat1p). Naa50p (Nat5) is physically associated with NatA. In man, hNaa50p was shown to have acetyltransferase activity and to be important for chromosome segregation. In this study, we used purified recombinant hNaa50p and multiple oligopeptide substrates to identify and characterize an N^α-acetyltransferase activity of hNaa50p. As the preferred substrate this activity acetylates oligopeptides with N termini Met-Leu-Xxx-Pro. Furthermore, hNaa50p autoacetylates lysines 34, 37, and 140 in vitro, modulating hNaa50p substrate specificity. In addition, histone 4 was detected as a hNaa50p KAT substrate in vitro. Our findings thus provide the first experimental evidence of an enzyme having both KAT and NAT activities.     

Notes on feeding ecology of macrourid fishes from the mid-Atlantic Ridge, North Atlantic

At least 16 macrourid fishes (Gadiformes, Macrouridae) inhabit the mid-Atlantic Ridge of the North Atlantic. To investigate the roles of macrourids in the food-web and compare feeding patterns of the most frequent co-occurring species, diet information on five of the species were described and compared. Pelagic and benthopelagic copepods were the most numerous prey but did not contribute much on a weight basis. Cephalopods were by far the most important prey of the small grenadiers, while shrimps and fish became increasingly significant with increasing size. Previous studies from other areas have also found pelagic prey to be important, but in contrast to this study, cephalopods were more important on the mid-Atlantic Ridge than in continental margin locations.     

Resource sharing among cod, haddock, saithe and pollack on a herring spawning ground

Cod Gadus morhua , haddock Melanogrammus aeglefinus , pollack Pollachius pollachius and saithe Pollachius virens were abundant fishes on herring Clupea harengus spawning grounds o. southwestern Norway. Their diets were species specific and ontogenetic changes were similar to patterns observed in other areas, indicating both inter- and intraspecific resource sharing. However, strong interspecific diet overlap occurred when cod and pollack preyed upon sandeel Ammodytes marinus , and when all the gadoids fed on herring eggs during the herring spawning season in the spring. These prey items were very abundant and the extensive diet overlap may not reflect strong competitive interaction.     

Microbial communities related to biodegradation of dispersed Macondo oil at low seawater temperature with Norwegian coastal seawater

The Deepwater Horizon (DWH) accident in 2010 created a deepwater plume of small oil droplets from a deepwater well in the Mississippi Canyon lease block 252 (‘Macondo oil’). A novel laboratory system was used in the current study to investigate biodegradation of Macondo oil dispersions (10 μm or 30 μm median droplet sizes) at low oil concentrations (2 mg l⁻¹) in coastal Norwegian seawater at a temperature of 4–5°C. Whole metagenome analyses showed that oil biodegradation was associated with the successive increased abundances of Gammaproteobacteria, while Alphaproteobacteria (Pelagibacter) became dominant at the end of the experiment. Colwellia and Oceanospirillales were related to n-alkane biodegradation, while particularly Cycloclasticus and Marinobacter were associated with degradation of aromatic hydrocarbons (HCs). The larger oil droplet dispersions resulted in delayed sequential changes of Oceanospirillales and Cycloclasticus, related with slower degradation of alkanes and aromatic HCs. The bacterial successions associated with oil biodegradation showed both similarities and differences when compared with the results from DWH field samples and laboratory studies performed with deepwater from the Gulf of Mexico.