Crystal structure of Pyrococcus furiosus PF2050, a member of the DUF2666 protein family

Pyrococcus furiosus PF2050 is an uncharacterized putative protein that contains two DUF2666 domains. Functional and structural studies of PF2050 have not previously been performed. In this study, we determined the crystal structure of PF2050. The structure of PF2050 showed that the two DUF2666 domains interact tightly, forming a globular structure. Each DUF2666 domain comprises an antiparallel β-sheet and an α-helical bundle. One side of the PF2050 structure has a positively charged basic cleft, which may have a DNA-binding function. Furthermore, we confirmed that PF2050 interacts with circular and linear dsDNA.     

Complement C3a-induced IL-17 plays a critical role in an IgE-mediated late-phase asthmatic response and airway hyperresponsiveness via neutrophilic inflammation in mice

Allergen-specific IgE plays an essential role in the pathogenesis of allergic asthma. Although there has been increasing evidence suggesting the involvement of IL-17 in the disease, the relationship between IL-17 and IgE-mediated asthmatic responses has not yet been defined. In this study, we attempted to elucidate the contribution of IL-17 to an IgE-mediated late-phase asthmatic response and airway hyperresponsiveness (AHR). BALB/c mice passively sensitized with an OVA-specific IgE mAb were challenged with OVA intratracheally four times. The fourth challenge caused a late-phase increase in airway resistance associated with elevated levels of IL-17(+)CD4(+) cells in the lungs. Multiple treatments with a C3a receptor antagonist or anti-C3a mAb during the challenges inhibited the increase in IL-17(+)CD4(+) cells. Meanwhile, a single treatment with the antagonist or the mAb at the fourth challenge suppressed the late-phase increase in airway resistance, AHR, and infiltration by neutrophils in bronchoalveolar lavage fluid. Because IL-17 production in the lungs was significantly repressed by both treatments, the effect of an anti-IL-17 mAb was examined. The late-phase increase in airway resistance, AHR, and infiltration by neutrophils in bronchoalveolar lavage fluid was inhibited. Furthermore, an anti-Gr-1 mAb had a similar effect. Collectively, we found that IgE mediated the increase of IL-17(+)CD4(+) cells in the lungs caused by repeated Ag challenges via C3a. The mechanisms leading to the IgE-mediated late-phase asthmatic response and AHR are closely associated with neutrophilic inflammation through the production of IL-17 induced by C3a.     

Role of the blood–cerebrospinal fluid barrier transporter as a cerebral clearance system for prostaglandin E2 produced in the brain

An increasing level of prostaglandin (PG) E₂ is involved in the progression of neuroinflammation induced by ischemia and bacterial infection. Although an imbalance in the rates of production and clearance of PGE₂ under these pathological conditions appears to affect the concentration of PGE₂ in the cerebrospinal fluid (CSF), the regulatory system remains incompletely understood. The purpose of this study was to investigate the cellular system of PGE₂ production via microsomal PGE synthetase‐1 (mPGES‐1), the inducible PGE₂‐generating enzyme, and PGE₂ elimination from the CSF via the blood–CSF barrier (BCSFB). Immunohistochemical analysis revealed that mPGES‐1 was expressed in the soma and perivascular sheets of astrocytes, pia mater, and brain blood vessel endothelial cells, suggesting that these cells are local production sites of PGE₂ in the CSF. The in vivo PGE₂ elimination clearance from the CSF was eightfold greater than that of d ‐mannitol, which is considered to reflect CSF bulk flow. This process was inhibited by the simultaneous injection of unlabeled PGE₂ and β‐lactam antibiotics, such as benzylpenicillin, cefazolin, and ceftriaxone, which are substrates and/or inhibitors of organic anion transporter 3 (OAT3). The characteristics of PGE₂ uptake by the isolated choroid plexus were at least partially consistent with those of OAT3. OAT3 was able to mediate PGE₂ transport with a Michaelis–Menten constant of 4.24 μM. These findings indicate that a system regulating the PGE₂ level in the CSF involves OAT3‐mediated PGE₂ uptake by choroid plexus epithelial cells, acting as a cerebral clearance pathway via the BCSFB of locally produced PGE₂.     

Metagenomic characterization of airborne viral DNA diversity in the near-surface atmosphere

Airborne viruses are expected to be ubiquitous in the atmosphere but they still remain poorly understood. This study investigated the temporal and spatial dynamics of airborne viruses and their genotypic characteristics in air samples collected from three distinct land use types (a residential district [RD], a forest [FR], and an industrial complex [IC]) and from rainwater samples freshly precipitated at the RD site (RD-rain). Viral abundance exhibited a seasonal fluctuation in the range between 1.7 × 10(6) and 4.0 × 10(7) viruses m(-3), which increased from autumn to winter and decreased toward spring, but no significant spatial differences were observed. Temporal variations in viral abundance were inversely correlated with seasonal changes in temperature and absolute humidity. Metagenomic analysis of air viromes amplified by rolling-circle phi29 polymerase-based random hexamer priming indicated the dominance of plant-associated single-stranded DNA (ssDNA) geminivirus-related viruses, followed by animal-infecting circovirus-related sequences, with low numbers of nanoviruses and microphages-related genomes. Particularly, the majority of the geminivirus-related viruses were closely related to ssDNA mycoviruses that infect plant-pathogenic fungi. Phylogenetic analysis based on the replication initiator protein sequence indicated that the airborne ssDNA viruses were distantly related to known ssDNA viruses, suggesting that a high diversity of viruses were newly discovered. This research is the first to report the seasonality of airborne viruses and their genetic diversity, which enhances our understanding of viral ecology in temperate regions.     

Apigenin induces apoptosis via extrinsic pathway,inducing p53 and inhibiting STAT3 and NFκB signaling in HER2-overexpressing breast cancer cells

Phytoestrogens are known to prevent tumor induction. But their molecular mechanisms of action are still unknown. This study aimed to examine the effect of apigenin on proliferation and apoptosis in HER2-expressing breast cancer cells. In our experiments, apigenin inhibited the proliferation of MCF-7 vec and MCF-7 HER2 cells. This growth inhibition was accompanied with an increase of sub G(0)/G(1) apoptotic fractions. Overexpression of HER2 did not confer resistance to apigenin in MCF-7 cells. Apigenin-induced extrinsic apoptosis pathway up-regulating the levels of cleaved caspase-8, and inducing the cleavage of poly (ADP-ribose) polymerase, whereas apigenin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease mitochondrial membrane potential maintaining red fluorescence and did not affect the levels of B-cell lymphoma 2 (BCL2) and Bcl-2-associated X protein. Moreover, apigenin reduced the tyrosine phosphorylation of HER2 (phospho-HER2 level) in MCF-7 HER2 cells, and up-regulated the levels of p53, phospho-p53 and p21 in MCF-7 vec and MCF-7 HER2 cells. This suggests that apigenin induces apoptosis through p53-dependent pathway. Apigenin also reduced the expression of phospho-JAK1 and phospho-STAT3 and decreased STAT3-dependent luciferase reporter gene activity in MCF-7 vec and MCF-7 HER2 cells. Apigenin decreased the phosphorylation level of IκBα in the cytosol, and abrogated the nuclear translocation of p65 within the nucleus suggesting that it blocks the activation of NFκB signaling pathway in MCF-7 vec and MCF-7 HER2 cells. Our study indicates that apigenin could be a potential useful compound to prevent or treat HER2-overexpressing breast cancer.     

ATM mediates interdependent activation of p53 and ERK through formation of a ternary complex with p-p53 and p-ERK in response to DNA damage

DNA damage in eukaryotic cells induces signaling pathways mediated by the ATM, p53 and ERK proteins, but the interactions between these pathways are not completely known. To address this issue, we performed a time course analysis in human embryonic fibroblast cells treated with DNA-damaging agents. DNA damage induced the phosphorylation of p53 at Ser 15 (p-p53) and the phosphorylation of ERK (p-ERK). Inhibition of p53 by a dominant negative mutant or in p53(-/-) fibroblast cells abolished ERK phosphorylation. ERK inhibitor prevented p53 phosphorylation, indicating that phosphorylations of p53 and p-ERK are interdependent each other. A time course analysis showed that ATM interacted with p-p53 and p-ERK in early time (0.5 h) and interaction between ATM-bound p-p53 and p-ERK or ATM-bound p-ERK and p-p53 occurred in late time (3 h) of DNA damage. These results indicate that ATM mediates interdependent activation of p53 and ERK through formation of a ternary complex between p-p53 and p-ERK in response to DNA damage to cause growth arrest.     

Genetic variants of the <Emphasis Type="Italic">FABP4</Emphasis> gene are associated with marbling scores and meat quality grades in Hanwoo (Korean cattle)

This study was aimed to search new genetic variants in the bovine FABP4 gene as molecular markers for meat quality and carcass traits. PCR–RFLP analysis revealed that three SNPs located at nucleotide positions g.2834C>G, g.3533T>A, and g.3691G>A were identified based on a GenBank accession number (NC_007312.4). Sequence analysis revealed that SNPs were located in intron 1 (g.2834C>G) and 2 (g.3533T>A), and an exon 3 (g.3691G>A), showing allele frequencies as 0.592, 0.579, and 0.789, respectively. Genetic variabilities of heterozygosity (He) and polymorphic information contents (PIC) were estimated for g.2834C>G (0.608 and 0.531), g.3533T>A (0.615 and 0.539), and g.3691G>A (0.498 and 0.401) loci, respectively. A SNP located in the exon 3 of FABP4 was characterized and associated with desirable increases of MS (marbling scores) and MG (meat quality grades) in Hanwoo. The statistical analysis revealed that additive effects by GG genotypes in g.3691G>A SNP were significantly greater than AA genotypes in MS and MG traits. These findings suggest that the FABP4g.3691G>A SNP will be a useful candidate locus to maximize economic benefits for cattle populations.     

Three-dimensional geometry of the human carotid artery

Accurate characterization of carotid artery geometry is vital to our understanding of the pathogenesis of atherosclerosis. Three-dimensional computer reconstructions based on medical imaging are now ubiquitous; however, mean carotid artery geometry has not yet been comprehensively characterized. The goal of this work was to build and study such geometry based on data from 16 male patients with severe carotid artery disease. Results of computerized tomography angiography were used to analyze the cross-sectional images implementing a semiautomated segmentation algorithm. Extracted data were used to reconstruct the mean three-dimensional geometry and to determine average values and variability of bifurcation and planarity angles, diameters and cross-sectional areas. Contrary to simplified carotid geometry typically depicted and used, our mean artery was tortuous exhibiting nonplanarity and complex curvature and torsion variations. The bifurcation angle was 36 deg?±?11 deg if measured using arterial centerlines and 15 deg?±?14 deg if measured between the walls of the carotid bifurcation branches. The average planarity angle was 11 deg?±?10 deg. Both bifurcation and planarity angles were substantially smaller than values reported in most studies. Cross sections were elliptical, with an average ratio of semimajor to semiminor axes of 1.2. The cross-sectional area increased twofold in the bulb compared to the proximal common, but then decreased 1.5-fold for the combined area of distal internal and external carotid artery. Inter-patient variability was substantial, especially in the bulb region; however, some common geometrical features were observed in most patients. Obtained quantitative data on the mean carotid artery geometry and its variability among patients with severe carotid artery disease can be used by biomedical engineers and biomechanics vascular modelers in their studies of carotid pathophysiology, and by endovascular device and materials manufacturers interested in the mean geometrical features of the artery to target the broad patient population.