RETRACTED ARTICLE: Therapeutic DNA Vaccination as a Repair Strategy Following Spinal Cord Injury

Myelin-derived proteins, such as tenascin-R (TN-R), myelin associate glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), and Nogo-A, inhibit the central nervous system regeneration. In this study, the DNA vaccine encoding for oligodendrocyte and myelin-related antigens was employed to attenuate the axonal growth inhibitory properties of myelin in the setting of spinal cord injury. Using a rat spinal cord dorsal hemisection model, the vaccine directed against the inhibitory epitopes of Nogo-A, MAG, OMgp, and TN-R was administered intramuscularly once a week following spinal cord injury, supplemented with local application of specific anti-sera against the four antigens. Anterograde labeling of dorsal column fibers showed active axonal regeneration through the lesion site at the eighth week following the treatment in experimental group but not in control groups. Light microscopic and ultrastructural analysis revealed that vaccination with these myelin-related antigens did not lead to demyelinating disease. OMgp and TN-R levels were down-regulated at the lesion site together with a parallel increase in growth-associated protein 43 levels in the treatment groups. This study reveals the effective approach of a DNA vaccine strategy by attaining the special antibody to direct neutralization of the myelin inhibitors during spinal cord injury.     

A novel Phytochrome B allele in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> exhibits partial mutant phenotype: a short deletion in N-terminal extension reduces Phytochrome B activity

During analysis of an Arabidopsis thaliana line possessing a Phytochrome A epiallele (phyA’), a partial Phytochrome B-deficient phenotype was observed, consisting of elongated hypocotyls in seedlings grown under constant white light or red light (660 nm). The observed hypocotyls were twice the length (8 mm) of wild-type (4 mm), but approximately half the length of a null phyB-9 mutant (14 mm). Several analyses were performed to characterize this apparent partial phyB mutant. Sequencing of the entire exonic region revealed three point mutations that altered codon usage, and one in-frame 12 base pair deletion. Each of the point mutations has been described in other lines that display wild-type phenotype, and therefore their effect is thought to be minimal, if any. The N-terminal deletion of amino acids 9 through 12 (GGGR) is a unique mutation found in this line. This deletion most likely contributes to the phyB mutant phenotype by lowering the binding affinity of the active form of Phytochrome B (Pfr) with Phytochrome Interacting Factor 3 (PIF3).     

Selection on flowering time in Mediterranean high-mountain plants under global warming

Under climate warming, plants will undergo novel selective pressures to adjust reproductive timing. Adjustment between reproductive phenology and environment is expected to be higher in arctic and alpine habitats because the growing season is considerably short. As early- and late-flowering species reproduce under very different environmental conditions, selective pressures on flowering phenology and potential effects of climate change are likely to differ between them. However, there is no agreement on the magnitude of the benefits and costs of early- vs. late-flowering species under a global warming scenario. In spite of its relevance, phenotypic selection on flowering phenology has rarely been explored in alpine plants and never in Mediterranean high mountain species, where selective pressures are very different due to the summer drought imposed over the short growth season. We hypothesized that late-flowering plants in Mediterranean mountains should present stronger selective pressures towards early onset of reproduction than early-flowering species, because less water is available in the soil as growing season progresses. We performed selection analyses on flowering onset and duration in two high mountain species of contrasting phenology. Since phenotypic selection can be highly context-dependent, we studied several populations of each species for 2 years, covering their local altitudinal ranges and their different microhabitats. Surrogates of biotic selective agents, like fruitset for pollinators and flower and fruit loss for flower and seed predators, were included in the analysis. Differences between the early- and the late-flowering species were less than expected. A consistent negative correlational selection of flowering onset and duration was found affecting plant fitness, i.e., plants that bloomed earlier flowered for longer periods improving plant fitness. Nevertheless, the late-flowering species may experience higher risks under climate warming because in extremely warm and dry years the earlier season does not bring about a longer flowering duration due to summer drought.     

DiffCoEx: a simple and sensitive method to find differentially coexpressed gene modules

Background  

Large microarray datasets have enabled gene regulation to be studied through coexpression analysis. While numerous methods have been developed for identifying differentially expressed genes between two conditions, the field of differential coexpression analysis is still relatively new. More specifically, there is so far no sensitive and untargeted method to identify gene modules (also known as gene sets or clusters) that are differentially coexpressed between two conditions. Here, sensitive and untargeted means that the method should be able to construct de novo modules by grouping genes based on shared, but subtle, differential correlation patterns.     

Sustained Release of Poorly Water-Soluble Drug from Hydrophilic Polymeric Film Sandwiched Between Hydrophobic Layers

This proof-of-concept study explores the feasibility of using a drug-loaded hydrophilic polymeric layer sandwiched between two hydrophobic layers for improving film drug load while achieving sustained release of poorly water-soluble drug. Such films having total thickness in range ~?146–250 μm were prepared by slurry-based casting using hydrophilic hydroxypropyl methylcellulose (HPMC) as matrix layer containing fenofibrate (FNB) as the model drug, encased between two very thin rate-limiting layers of 10 μm each of hydrophobic poly-?-caprolactone (PCL). Film precursor slurry consisted of HPMC with plasticizer and water along with micronized FNB powders, which were dry-coated with hydrophilic silica. Characterization techniques demonstrated the presence of homogeneously dispersed crystalline FNB in films. The films are very thin and hence two-dimensional; hence, average drug load per unit area in range ~?5 to ~?9 mg/cm² could be achieved by altering the thickness of the drug matrix layer. Drug amount and drug content uniformity were measured through assay of ten circular samples ~?0.712 cm² in area punched out using a circular-shaped punch tool. Drug release rate was investigated using USP IV flow-through cell and surface dissolution imaging system. Thinner films followed Fickian diffusion, and thicker films followed non-Fickian anomalous diffusion. Overall, the application of middle layer thickness could be used as a tool to manipulate drug load without the need for altering its formulation or precursor preparation by changing its thickness, hence achieving relatively high drug loading yet having sustained release of drug.     

Enhanced Biotransformation of 2-Phenylethanol with Ethanol Oxidation in a Solid–Liquid Two-Phase System by Active Dry Yeast

2-Phenylethanol (2-PE) can be produced from l-phenylalanine (l-Phe) with the oxidation degradation of ethanol by active dry yeast. In this study, the catalysis effect of ethanol on biotransforming l-Phe into 2-PE by yeast was evaluated and optimized. The results indicated that increasing ethanol concentration was beneficial for enhancing 2-PE concentration but lowered the 2-PE productivity. Initial ethanol concentration above 25 g/l could strongly inhibit the 2-PE production. To obtain 2-PE with desirable concentrations with an economical operation mode, three fed-batch biotransformation operation methods using ethanol or/and glucose were carried out in a solid–liquid two-phase system. When using ethanol alone with the initial concentration of 10 g/l, the total concentration and overall productivity of 2-PE were 7.6 g/l and 0.065 g l⁻¹ h⁻¹, respectively. Furthermore, an experiment with controlled glucose solely (higher than 2 g/l) was finished. In this case, phenylacetaldehyde (PA) was detected along with ethanol accumulation, suggesting that reaction of PA → 2-PE in Ehrlich pathway was inhibited. To further enhance 2-PE production by using glucose only, a novel operation strategy to simultaneously control rates of glucose glycolysis and ethanol oxidative degradation with the aid of ISPR techniques was developed. With this strategy, 2-PE concentration and yield based on glucose consumption reached a higher level of 14.8 g/l and 0.12 g-PE/g-glucose, respectively, and these are the highest values reported up to date with the fed-batch biotransformation operation mode.     

Conversion of aliphatic nitriles by the arylacetonitrilase from <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> EBC191

The conversion of aliphatic nitriles by the arylacetonitrilase from Pseudomonas fluorescens EBC191 (NitA) was analyzed. The nitrilase hydrolysed a wide range of aliphatic mono- and dinitriles and showed a preference for unsaturated aliphatic substrates containing 5–6 carbon atoms. In addition, increased reaction rates were also found for aliphatic nitriles carrying electron withdrawing substituents (e.g. chloro- or hydroxy-groups) close to the nitrile group. Aliphatic dinitriles were attacked only at one of the nitrile groups and with most of the tested dinitriles the monocarboxylates were detected as major products. In contrast, fumarodinitrile was converted to the monocarboxylate and the monocarboxamide in a ratio of about 65:35. Significantly different relative amounts of the two products were observed with two nitrilase variants with altered reaction specifities. NitA converted some aliphatic substrates with higher rates than 2-phenylpropionitrile, which is one of the standard substrates for arylacetonitrilases. This indicated that the traditional classification of nitrilases as “arylacetonitrilases”, “aromatic” or “aliphatic” nitrilases might require some corrections. This was also suggested by the construction of some variants of NitA which were modified in an amino acid residue which was previously suggested to be essential for the conversion of aliphatic substrates by a homologous nitrilase.     

Crocetin attenuates inflammation and amyloid-β accumulation in APPsw transgenic mice

Background

Crocetin, an agent derived from saffron, has multiple pharmacological properties, such as neuroprotective, anti-oxidant, and anti-inflammatory actions. These properties might benefit the treatment of Alzheimer’s disease (AD). In the present study, we tested whether crocetin attenuates inflammation and amyloid-β (Aβ) accumulation in APPsw transgenic mice, AD mouse models. Cell viability and the levels of Aβ40 and Aβ42 in HeLa cells stably transfected with Swedish mutant APP751 were evaluated. Mice with Swedish mutant APP751 transgene were used as transgenic mouse models of AD, and were orally administrated with crocetin. Aβ protein and inflammatory cytokines were measured with ELISA. NF-κB and P53 were measured with western blot assay. Learning and memory were analyzed with Morris water maze and novel object recognition tests.

Results

Crocetin significantly reduced Aβ40 and Aβ42 secretion in Hela cells without effecting cell viability. In AD transgenic mice, crocetin significantly reduced the pro-inflammatory cytokines and enhanced anti-inflammatory cytokine in plasma, suppressed NF-κB activation and P53 expression in the hippocampus, decreased Aβ in various brain areas, and improved learning and memory deficits.

Conclusion

Crocetin improves Aβ accumulation-induced learning and memory deficit in AD transgenic mice, probably due to its anti-inflammatory and anti-apoptotic functions.

     

Restricted dispersal in a long-distance migrant bird with patchy distribution,the great reed warbler

In patchily distributed species dispersal connects local populations into metapopulations. Reliable quantifications of dispersal are therefore crucial to understanding the population dynamics and genetic structure of such metapopulation systems. The great reed warbler (Acrocephalus arundinaceus) inhabits eutrophic lakes and has a patchy breeding distribution. In this study we investigated the dispersal pattern of the great reed warbler based on an extensive capture-recapture effort covering a large census area (22,500 km²). At two adjacent breeding sites (10 km apart) in southern Central Sweden, the "main study area", we ringed the majority of adult and nestling great reed warblers between 1992 and 1999. In 1998 and 1999, we opportunistically searched for territorial males at the majority of the Swedish breeding sites, and were able to examine about 56% of all males in the region. Analyses of recaptured males demonstrated that philopatry predominated. Sixty-nine percent of the recruiting nestlings returned to breed in the main study area (their natal area), and 92% of the resighted adults were found at the same breeding locality in both study years. Breeding dispersal was significantly more restricted than natal dispersal. Additional data on natal and breeding dispersal within the main study area in 1992-1999 suggested that females were as philopatric as males. The overall high level of philopatry, with only occasional longer dispersal distances documented, yielded a root-mean-square dispersal distance of 33 km per generation. High philopatry, short dispersal distances and similar dispersal patterns of male and female great reed warblers contrast the findings among birds in general, but conform to data of species having patchy breeding habitat and isolated populations. Restricted dispersal suggests limited gene flow even among several Swedish populations, which is in line with some previous findings of the population ecology of the great reed warbler: (1) structured mtDNA lineages among European populations; (2) small-scale population differences in song patterns; and (3) low genetic variation and occurrence of inbreeding depression in our main study population.     

Surface characteristics of grasslands in Inner Mongolia as detected by micrometeorological measurements

A roving tower concept was used to compare a semi-arid grassland site in Inner Mongolia (China), which was fenced in 1979 and ungrazed thereafter (UG79) with differently grazed semi-arid steppe ecosystems. The study was conducted during three consecutive years characterised by contrasting precipitation. The different grazing intensities included continuously and moderately grazed (CG), winter grazed (WG), and heavily grazed (HG). Here, we compare the energy fluxes and surface parameters that characterise the differently managed plots. The main focus is on sensible heat flux (H), available energy (AE), surface temperature (T ( s )), and surface albedo (alpha). Systematic errors were excluded by a side-to-side intercomparison of the instruments, and systematic climatic differences were minimised by the close distance between the fixed and the roving eddy covariance tower. Statistically, AE and T ( s ) were always significantly different between two simultaneously measured grazing intensities. Whereas AE was higher at UG79 in all years (mean difference of about 19Wm(-2)), T ( s ) was typically lower at UG79 (mean differences of 0.4 degrees C to about 2 degrees C). The exception was the end of the vegetation period in 2004 when T ( s ) was 0.6 degrees C higher at UG79 compared to CG. At UG79 alpha was typically significantly lower, and H was typically significantly higher. Consequently, latent heat fluxes (both as energy balance residual and directly measured) do not differ much between the different grazing intensities. It is concluded, that (1) the roving tower concept is able to detect differences due to grazing, (2) differences between the sites can be attributed to real surface differences, and (3) differences due to grazing intensities are small compared to interannual differences in surface fluxes.