Removal of FKBP12.6 does not alter the conductance and activation of the cardiac ryanodine receptor or the susceptibility to stress-induced ventricular arrhythmias

The 12.6-kDa FK506-binding protein (FKBP12.6) is considered to be a key regulator of the cardiac ryanodine receptor (RyR2), but its precise role in RyR2 function is complex and controversial. In the present study we investigated the impact of FKBP12.6 removal on the properties of the RyR2 channel and the propensity for spontaneous Ca(2+) release and the occurrence of ventricular arrhythmias. Single channel recordings in lipid bilayers showed that FK506 treatment of recombinant RyR2 co-expressed with or without FKBP12.6 or native canine RyR2 did not induce long-lived subconductance states. [(3)H]Ryanodine binding studies revealed that coexpression with or without FKBP12.6 or treatment with or without FK506 did not alter the sensitivity of RyR2 to activation by Ca(2+) or caffeine. Furthermore, single cell Ca(2+) imaging analyses demonstrated that HEK293 cells co-expressing RyR2 and FKBP12.6 or expressing RyR2 alone displayed the same propensity for spontaneous Ca(2+) release or store overload-induced Ca(2+) release (SOICR). FK506 increased the amplitude and decreased the frequency of SOICR in HEK293 cells expressing RyR2 with or without FKBP12.6, indicating that the action of FK506 on SOICR is independent of FKBP12.6. As with recombinant RyR2, the conductance and ligand-gating properties of single RyR2 channels from FKBP12.6-null mice were indistinguishable from those of single wild type channels. Moreover, FKBP12.6-null mice did not exhibit enhanced susceptibility to stress-induced ventricular arrhythmias, in contrast to previous reports. Collectively, our results demonstrate that the loss of FKBP12.6 has no significant effect on the conduction and activation of RyR2 or the propensity for spontaneous Ca(2+) release and stress-induced ventricular arrhythmias.     

Potential resistance of tricin in rice against brown planthopper Nilaparvata lugens (Stål)

The aerial parts of resistant rice plant (IR36) was immersed in 85% ethanol at room temperature, and ethanol-soluble extracts were prepared. Different solvents including petroleum ether, ethyl acetate, absolute ethanol, and water were then used to separate the ethanol-soluble extracts and different solvent fractions were obtained. These fractions were tested for their effects on the mortality rate of the brown planthopper nymphae (BPH). The results indicated that EtOAc fractions had significant effects on the mortality of brown planthopper nymphae after the third day of treatment. EtOAc fractions of resistant rice plants (IR36) were separated using column chromatography over silica gel and 5,7,4′ -trihydroxy-3′,5′-dimethoxyflavone (tricin) was isolated. After the BPH were allowed to feed on diets containing tricin for 15 days, it was found that the weight of honeydew of the nymphae showed a decrease as tricin concentrations in the diets increased. The mortality rate of the nymphae increased with increasing tricin concentration. The corrected mortality rate was 58.21% for the 3rd instar nymphae and 31.75% for the 4th instar nymphae, respectively, at 500 μg/ml concentration. In addition, tricin (500 μg/ml) significantly inhibited oviposition behavior and feeding of the brown planthopper females in choice tests when spread on susceptible rice plant (TN1).     

PCR-DGGE detection of the bacterial community structure in the Inner Mongolia steppe with two different DNA extraction methods

Compared with conventional methods, molecular biological technique, such as PCR-DGGE (denaturing gradient gel electrophoresis), is informative in examining the structure of the soil bacterial community through the extraction of microbial DNA from soil and generation of bacterial community profiles by PCR amplification of 16S rRNA genes. Extraction efficiency of soil microbial DNA is the most important step in these methods. At present, the frozen-thawing method and bead-beating method are most widely used in genomic extraction. Nevertheless, comparison of these two methods has not been conducted in different soil types, especially in humus-rich soil. In this study, extraction efficiencies of the two methods were compared in humus-rich steppe soil in Inner Mongolia based on the PCR-DGGE analysis of bacterial community structure. The results indicated that the bead-beating method is better than the frozen-thawing method in genomic DNA extraction efficiency. In addition, 21 bands in the DGGE pattern with the bead-beating method were further selected, cloned and sequenced. Based on similarity matching, all the sequences formed five major clusters: Actinobacteria; α-, β-, γ-, Proteobacteria ; Bacteriodetes ; Gemmatimonadetes and Acidobacteria . Of the 21 clones obtained from DGGE patterns, YC4 showed 99.7% similarity to Pseudomonas sp. (DQ339153); YC5, YC18 and YC19 showed 99.9 % similarity to Gram-positive bacterium (AB008510), Virgisporangium ochraceum (AB006162) and Micromonospora chalcea (X92613), respectively.     

Deep subcutaneous adipose tissue: a distinct abdominal adipose depot

Objective: Abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) display significant metabolic differences, with VAT showing a functional association to metabolic/cardiovascular disorders. A third abdominal adipose layer, derived by the division of SAT and identified as deep subcutaneous adipose tissue (dSAT), may play a significant and independent metabolic role. The aim of this study was to evaluate depot‐specific differences in the expression of proteins key to adipocyte metabolism in a lean population to establish a potential physiologic role for dSAT. Research Methods and Procedures: Adipocytes and preadipocytes were isolated from whole biopsies taken from superficial SAT (sSAT), dSAT, and VAT samples obtained from 10 healthy normal weight patients (7 women and 3 men), with a mean age of 56.4 ± 4.04 years and a mean BMI of 23.1 ± 0.5 kg/m². Samples were evaluated for depot‐specific differences in insulin sensitivity using adiponectin, glucose transport protein 4 (GLUT4), and resistin mRNA and protein expression, glucocorticoid metabolism by 11β‐hydroxysteroid dehydrogenase type‐1 (11β‐HSD1) expression, and alterations in the adipokines leptin and tumor necrosis factor‐α (TNF‐α). Results: Although no regional differences in expression were observed for adiponectin or TNF‐α, dSAT whole biopsies and adipocytes, while intermediary to both sSAT and VAT, reflected more of the VAT expression profile of 11β‐HSD1, leptin, and resistin. Only in the case of the intracellular pool of GLUT4 proteins in whole biopsies was an independent pattern of expression observed for dSAT. In an evaluation of the homeostatic model, dSAT 11β‐HSD1 protein (r = 0.9573, p = 0.0002) and TNF‐α mRNA (r = 0.8210, p = 0.0236) correlated positively to the homeostatic model. Discussion: Overall, dSAT seems to be a distinct abdominal adipose depot supporting an independent metabolic function that may have a potential role in the development of obesity‐associated complications.     

High resolution population maps for low income nations: combining land cover and census in East Africa

Background

Between 2005 and 2050, the human population is forecast to grow by 2.7 billion, with the vast majority of this growth occurring in low income countries. This growth is likely to have significant social, economic and environmental impacts, and make the achievement of international development goals more difficult. The measurement, monitoring and potential mitigation of these impacts require high resolution, contemporary data on human population distributions. In low income countries, however, where the changes will be concentrated, the least information on the distribution of population exists. In this paper we investigate whether satellite imagery in combination with land cover information and census data can be used to create inexpensive, high resolution and easily-updatable settlement and population distribution maps over large areas.

Methodology/Principal Findings

We examine various approaches for the production of maps of the East African region (Kenya, Uganda, Burundi, Rwanda and Tanzania) and where fine resolution census data exists, test the accuracies of map production approaches and existing population distribution products. The results show that combining high resolution census, settlement and land cover information is important in producing accurate population distribution maps.

Conclusions

We find that this semi-automated population distribution mapping at unprecedented spatial resolution produces more accurate results than existing products and can be undertaken for as little as $0.01 per km². The resulting population maps are a product of the Malaria Atlas Project (MAP: http://www.map.ox.ac.uk) and are freely available.     

The golden beauty: brain response to classical and renaissance sculptures

Is there an objective, biological basis for the experience of beauty in art? Or is aesthetic experience entirely subjective? Using fMRI technique, we addressed this question by presenting viewers, naïve to art criticism, with images of masterpieces of Classical and Renaissance sculpture. Employing proportion as the independent variable, we produced two sets of stimuli: one composed of images of original sculptures; the other of a modified version of the same images. The stimuli were presented in three conditions: observation, aesthetic judgment, and proportion judgment. In the observation condition, the viewers were required to observe the images with the same mind-set as if they were in a museum. In the other two conditions they were required to give an aesthetic or proportion judgment on the same images. Two types of analyses were carried out: one which contrasted brain response to the canonical and the modified sculptures, and one which contrasted beautiful vs. ugly sculptures as judged by each volunteer. The most striking result was that the observation of original sculptures, relative to the modified ones, produced activation of the right insula as well as of some lateral and medial cortical areas (lateral occipital gyrus, precuneus and prefrontal areas). The activation of the insula was particularly strong during the observation condition. Most interestingly, when volunteers were required to give an overt aesthetic judgment, the images judged as beautiful selectively activated the right amygdala, relative to those judged as ugly. We conclude that, in observers naïve to art criticism, the sense of beauty is mediated by two non-mutually exclusive processes: one based on a joint activation of sets of cortical neurons, triggered by parameters intrinsic to the stimuli, and the insula (objective beauty); the other based on the activation of the amygdala, driven by one''s own emotional experiences (subjective beauty).     

Molecular Population Genetics of Rice Domestication

Domestication is a selection process that genetically modifies species to meet human needs. A most intriguing feature of domestication is the extreme phenotypic diversification among breeds. What could be the ultimate source of such genetic variations? Another notable outcome of artificial selection is the reduction in the fitness of domesticated species when they live in the wild without human assistance. The complete sequences of the two subspecies of rice cultivars provide an opportunity to address these questions. Between the two subspecies, we found much higher rates of non‐synonymous (N) than synonymous (S) substitutions and the N/S ratios are higher between cultivars than between wild species. Most interestingly, substitutions of highly dissimilar amino acids that are deleterious and uncommon between natural species are disproportionately common between the two subspecies of rice. We suggest strong selection in the absence of effective recombination may be the driving force, which we called the domestication‐associated Hill‐Robertson effect. These hitchhiking mutations may contribute to some fitness reduction in cultivars. Comparisons of the two genomes also reveal the existence of highly divergent regions in the genomes. Haplotypes in these regions often form highly polymorphic linkage blocks that are much older than speciation between wild species. Genes from such regions could contribute to the differences between indica and japonica and are likely to be involved in the diversifying selection under domestication. Their existence suggests that the amount of genetic variation within the single progenitor species Oryza rufipogon may be insufficient to account for the variation among rice cultivars, which may come from a more inclusive gene pool comprising most of the A‐genome wild species. Genes from the highly polymorphic regions also provide strong support for the independent domestication of the two subspecies. The genomic variation in rice has revealing implications for studying the genetic basis of indica‐japonica differentiation under rice domestication and subsequent improvement.     

Adenovirus-mediated expression of both antisense ornithine decarboxylase and S-adenosylmethionine decarboxylase inhibits lung cancer cell growth

Polyamine biosynthesis is controlled primarily by ornithine decarboxylase (ODC) and Sadenosylmethionine decarboxylase (AdoMetDC). Antisense sequences of ODC and AdoMetDC genes were cloned into an adenoviral vector (named Ad-ODC-AdoMetDCas). To evaluate the effects of recombinant adenovirus Ad-ODC-AdoMetDCas that can simultaneously express both antisense ODC and AdoMetDC, the human lung cancer cell line A-549 was infected with Ad-ODC-AdoMetDCas or the control vector. Viable cell counting, determination of polyamine concentrations, cell cycle analysis, and Matrigel invasion assays were carried out to assess the properties of tumor growth and invasiveness. Our study showed that adenovirus-mediated antisense ODC and AdoMetDC expression inhibits tumor cell growth through blocking the polyamine synthesis pathway. Tumor cells were arrested at the G_1 phase after gene transfer and the invasiveness was reduced. It suggested that the recombinant adenovirus Ad-ODC-AdoMetDCas might be a new anticancer reagent in the treatment of lung cancers.