Vasohibin induces prolyl hydroxylase-mediated degradation of hypoxia-inducible factor-1α in human umbilical vein endothelial cells

Vasohibin is thought to be an important negative feedback regulator of angiogenesis that is selectively induced in endothelial cells by VEGF. Here, we assessed the role of vasohibin on HIF-1α expression under oxidative stress induced by hydrogen peroxide (H₂O₂) in HUVEC. VEGF induced significant cell growth that was associated with an increase in vasohibin expression. Following H₂O₂-pretreatment, VEGF further increased cell growth but this was contrastingly associated with a decrease in vasohibin expression when compared with VEGF alone. Interestingly, vasohibin inhibited cell proliferation through degradation of HIF-1α expression during H₂O₂-pretreatment. Furthermore, vasohibin elevated the expression of prolyl hydroxylase (PHD). These results suggest that vasohibin plays crucial roles as a negative feedback regulator of angiogenesis through HIF-1α degradation via PHD.     

Alien genes introgression and development of alien monosomic addition lines from a threatened species, Allium roylei Stearn, to Allium cepa L.

To produce alien monosomic addition lines (AMALs) of Allium cepa (genomes CC, 2n = 2x = 16) carrying extrachromosomes from Allium roylei (RR, 2n = 2x = 16), reciprocal backcrossing of allotriploids (2n = 24, CCR) with diploids (2n = 16, CC) and selfing of a single allotriploid were carried out. The chromosome numbers in the BC₂F₁ and BC₁F₂ progenies ranged from 16 to 32. Forty-eight plants were recorded to possess 2n = 17 among a total of 169 plants in observation. Through the analyses of isozymes, expressed sequence tag (EST) markers, and karyotypes, all eight possible types of A. cepa–A. roylei monosomic addition lines (CC+1R–CC+8R) could be identified. Seven types of representative AMALs (without CC+2R) were used for the GISH analysis of somatic chromosomes. Except for CC+6R, all AMALs showed an entire (unrecombined) extrachromosome from A. roylei in the integral diploid background of A. cepa. A single recombination between A. cepa and A. roylei was observed on the extrachromosome in the remaining type. All alloplasmic AMALs possessing A. roylei cytoplasm showed high or complete pollen sterility. Only the autoplasmic CC+4R with A. cepa cytoplasm possessed relatively high pollen fertility. The bulbs of CC+4R displayed the distinct ovoid shape that discriminates them from spherical or oval ones in other AMALs. Downy mildew screening in the field showed higher resistance in A. roylei, a hypo-allotriploid (CCR-nR, 2n = 23), and an allotriploid (CCR, 2n = 24). Meanwhile, no complete resistance was found in some AMALs examined. This was the first trial toward the establishment of a complete set of A. cepa–A. roylei monosomic additions.     

Dependence of alpha-helical and beta-sheet amino acid propensities on the overall protein fold type

ABSTRACT: BACKGROUND: A large number of studies have been carried out to obtain amino acid propensities for alpha- helices and beta-sheets. The obtained propensities for alpha-helices are consistent with each other, and the pair-wise correlation coefficient is frequently high. On the other hand, the beta-sheet propensities obtained by several studies differed significantly, indicating that the context significantly affects beta-sheet propensity. RESULTS: We calculated amino acid propensities for alpha-helices and beta-sheets for 39 and 24 protein folds, respectively, and addressed whether they correlate with the fold. The propensities were also calculated for exposed and buried sites, respectively. Results showed that alpha-helix propensities do not differ significantly by fold, but beta-sheet propensities are diverse and depend on the fold. The propensities calculated for exposed sites and buried sites are similar for alpha-helix, but such is not the case for the beta-sheet propensities. We also found some fold dependence on amino acid frequency in beta-strands. Folds with a high Ser, Thr and Asn content at exposed sites in beta-strands tend to have a low Leu, Ile, Glu, Lys and Arg content (correlation coefficient = 0.90) and to have flat beta-sheets. At buried sites in beta-strands, the content of Tyr, Trp, Gln and Ser correlates negatively with the content of Val, Ile and Leu (correlation coefficient = 0.93). "All-beta" proteins tend to have a higher content of Tyr, Trp, Gln and Ser, whereas alpha/beta proteins tend to have a higher content of Val, Ile and Leu. CONCLUSIONS: The alpha-helix propensities are similar for all folds and for exposed and buried residues. However, beta-sheet propensities calculated for exposed residues differ from those for buried residues, indicating that the exposed-residue fraction is one of the major factors governing amino acid composition in beta-strands. Furthermore, the correlations we detected suggest that amino acid composition is related to folding properties such as the twist of a beta-strand or association between two beta sheets.     

Diffuse large B-cell lymphoma presenting with neurolymphomatosis and intravascular lymphoma: a unique autopsy case with diverse neurological symptoms

Background

The diagnosis of uterine smooth muscle tumors depends on a combination of microscopic features. However, a small number of these tumors still pose difficult diagnostic challenges.

Aim

To investigate progesterone receptor (PR) and p53 expression in leiomyomas (LMs), atypical leiomyomas (ALMs), smooth muscle tumors of uncertain malignant potential (STUMP), and leiomyosarcomas (LMSs) and to evaluate the potential utility of the selected immunohistochemical markers in differentiating these tumors.

Materials and methods

Immunohistochemical expression of PR and p53 was investigated in 41 uterine smooth muscle tumors comprising: 15 LMS, 4 STUMP, 6 ALM and 16 LM. Quantitative evaluation of PR and p53 expression was graded on a scale from 0 to 3+.

Results

Leiomyosarcomas showed reduced PR expression. All LMs as well as ALMs and STUMP were stained intensely for PR. Conversely, LMS was strongly stained with p53, while the three non-sarcomatous groups (STUMP, ALM, LM) were either entirely negative or weakly stained for p53. Regarding both PR and p53 expression, the difference between the LMS group and the three non-sarcomatous groups was highly significant (p < 0.001). Combined high PR - low p53 expression was seen in all the 26 examined cases of the non-sarcomatous group including the STUMP cases and none of the LMS cases. Therefore, it represents a "benign" profile with 100% specificity in diagnosis of a non-sarcomatous tumor.

Conclusion

Immunohistochemistry for PR and p53 is valuable as an adjunct tool to morphological assessment of problematic uterine smooth muscle tumors.     

BNIP3 and NIX mediate Mieap-induced accumulation of lysosomal proteins within mitochondria

Mieap, a p53-inducible protein, controls mitochondrial quality by repairing unhealthy mitochondria. During repair, Mieap induces the accumulation of intramitochondrial lysosomal proteins (designated MALM for Mieap-induced accumulation of lysosome-like organelles within mitochondria) by interacting with NIX, leading to the elimination of oxidized mitochondrial proteins. Here, we report that an additional mitochondrial outer membrane protein, BNIP3, is also involved in MALM. BNIP3 interacts with Mieap in a reactive oxygen species (ROS)-dependent manner via the BH3 domain of BNIP3 and the coiled-coil domains of Mieap. The knockdown of endogenous BNIP3 expression severely inhibited MALM. Although the overexpression of either BNIP3 or NIX did not cause a remarkable change in the mitochondrial membrane potential (MMP), the co-expression of all three exogenous proteins, Mieap, BNIP3 and NIX, caused a dramatic reduction in MMP, implying that the physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may regulate the opening of a pore in the mitochondrial double membrane. This effect was not related to cell death. These results suggest that two mitochondrial outer membrane proteins, BNIP3 and NIX, mediate MALM in order to maintain mitochondrial integrity. The physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may play a critical role in the translocation of lysosomal proteins from the cytoplasm to the mitochondrial matrix.     

Gliding motility of Babesia bovis merozoites visualized by time-lapse video microscopy

Background

Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed “gliding motility”. However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs), and gliding motility has so far not been observed in the parasite.

Methodology/Principal Findings

Gliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion.

Conclusions/Significance

This is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding.     

A conformational restriction approach to the development of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease

Alzheimer's disease (AD) has been treated with acetylcholinesterase (AChE) inhibitors such as donepezil. However, the clinical usefulness of AChE inhibitors is limited mainly due to their adverse peripheral effects. Depression seen in AD patients has been treated with serotonin transporter (SERT) inhibitors. We considered that combining SERT and AChE inhibition could improve the clinical usefulness of AChE inhibitors. In a previous paper, we found a potential dual inhibitor, 1, of AChE (IC50=101 nM) and SERT (IC50=42 nM), but its AChE inhibition activity was less than donepezil (IC50=10 nM). Here, we report the conformationally restricted (R)-18a considerably enhanced inhibitory activity against AChE (IC50=14 nM) and SERT (IC50=6 nM).     

On-Probe Sample Pretreatment for Direct Analysis of Lipids in Gram-Positive Bacterial Cells by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

On-probe sample pretreatment using trifluoroacetic acid as an additional reagent enabled the direct detection of phospholipids in whole bacteria by means of matrix-assisted laser desorption ionization mass spectrometry for not only gram-negative organisms but also gram-positive ones with a thicker peptidoglycan layer.     

Active Transport and Accumulation of Iodide by Newly Isolated Marine Bacteria

Iodide (I⁻)-accumulating bacteria were isolated from marine sediment by an autoradiographic method with radioactive ¹²⁵I⁻. When they were grown in a liquid medium containing 0.1 μM iodide, 79 to 89% of the iodide was removed from the medium, and a corresponding amount of iodide was detected in the cells. Phylogenetic analysis based on 16S rRNA gene sequences indicated that iodide-accumulating bacteria were closely related to Flexibacter aggregans NBRC15975 and Arenibacter troitsensis, members of the family Flavobacteriaceae. When one of the strains, strain C-21, was cultured with 0.1 μM iodide, the maximum iodide content and the maximum concentration factor for iodide were 220 ± 3.6 (mean ± standard deviation) pmol of iodide per mg of dry cells and 5.5 × 10³, respectively. In the presence of much higher concentrations of iodide (1 μM to 1 mM), increased iodide content but decreased concentration factor for iodide were observed. An iodide transport assay was carried out to monitor the uptake and accumulation of iodide in washed cell suspensions of iodide-accumulating bacteria. The uptake of iodide was observed only in the presence of glucose and showed substrate saturation kinetics, with an apparent affinity constant for transport and a maximum velocity of 0.073 μM and 0.55 pmol min⁻¹ mg of dry cells⁻¹, respectively. The other dominant species of iodine in terrestrial and marine environments, iodate (IO₃⁻), was not transported.