Low rates of transmission of SRV-2 and STLV-I to juveniles in a population of Macaca fascicularis facilitate establishment of specific retrovirus-free colonies

Background  Prevalence of simian retrovirus-2 (SRV-2) and simian T lymphotropic virus type I (STLV-I), was unknown in 337 captive cynomolgus macaques.
Methods and Results  Molecular assays identified 29% of animals as SRV-2 mono-infected, 4% of animals as STLV-I mono-infected and 9% of animals as dual-infected. Of 108 juvenile animals, 83% were SRV-2-negative and no juvenile animal was STLV-I-positive. A subsequent study of juvenile macaques over a period of 2.5 years detected no STLV-I and 10 SRV-2 infections, six of which occurred between testing and day of colony formation. The study also highlighted that an anti-SRV-2 serological response does not presuppose infection. Tissue reservoirs of latent SRV-2 were not identified in suspected SRV-2 infections.
Conclusions  Low transmissibility of the viruses present in the parental cohort and improved knowledge of the host response to SRV-2 has facilitated the creation of specific-retrovirus-free colonies of cynomolgus macaques.     

Metadoxine, an ion-pair of pyridoxine and l-2-pyrrolidone-5-carboxylate, blocks adipocyte differentiation in association with inhibition of the PKA-CREB pathway

Adipogenesis is orchestrated by the expression of master adipogenic regulators. In particular, phosphorylation of cAMP response element binding protein (CREB) by protein kinase A promotes CREB nuclear translocation, thereby inducing expression of the adipogenic regulators and resulting in adipogenic maturation. Although metadoxine, an ion-pair of pyridoxine and l-2-pyrrolidone-5-carboxylate, has been shown to inhibit lipid accumulation in the liver, its effect on adipocyte differentiation has never been explored. This study investigated the effects of metadoxine on the differentiation of 3T3-L1 preadipocytes and the molecular mechanism. Metadoxine treatment did not inhibit mitotic clonal expansion, but inhibited late-stage cell differentiation, suggesting that metadoxine may block the differentiation step of preadipocytes. Metadoxine inhibited CREB phosphorylation and binding to the cAMP response element, thereby repressing CCAAT/enhancer-binding protein β during hormone-induced adipogenesis. Overall, metadoxine inhibits adipogenic differentiation in association with the inhibition of CREB/cAMP response element-dependent CCAAT/enhancer-binding protein β induction in the protein kinase A-CREB pathway.     

Isolation of quinupristin/dalfopristin-resistant <Emphasis Type="Italic">Streptococcus agalactiae</Emphasis> from asymptomatic Korean women

Seven Streptococcus agalactiae isolates were obtained from the vagina of 80 asymptomatic women. Three of these isolates showed multi-drug resistant (MDR) phenotypes: two isolates were resistant to clarithromycin, clindamycin, erythromycin, and tetracycline; and one isolate was resistant to clarithromycin, clindamycin, erythromycin, tetracycline, and quinupristin/dalfopristin. There was no clonal relationship among the MDR isolates. This is the first report of quinupristin/dalfopristin-resistant S. agalactiae.     

Role of genetic background in the introgressive hybridization of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>) with Westslope cutthroat trout (<Emphasis Type="Italic">O. clarkii lewisi</Emphasis>)

Conservation and management of endemic species may increasingly involve efforts to prevent hybridization with other species. Native westslope cutthroat trout (Oncorhynchus clarkii lewisi) management in western North America is based largely on admixture estimates with introduced rainbow trout (O. mykiss), with the highest conservation priority given to cutthroat populations that do not exhibit admixture. This study examined the hypothesis that such ancestry quotients are dependent upon the genetic background of reference rainbow trout populations. We used 10 microsatellite loci to estimate admixture within westslope cutthroat trout collected from 39 sites from Alberta, Canada, using three genetically distinct (pairwise F_ST = 0.100–0.281) rainbow trout genetic backgrounds: a wild (introduced) population from Alberta, two wild (native) populations from British Columbia, and a present-day hatchery broodstock line. Ancestry quotients were significantly impacted by genetic background, whereby the extent of admixture was highest with locally introduced (wild, naturalized) rainbow trout lines and lowest with the hatchery lines. Our results suggest that future studies ought to explore the possibility that local adaptation or drift in introduced rainbow trout populations may contribute to decreased reproductive isolation with geographically proximal cutthroat trout populations.     

Evaluation of apoptosis markers in different cell lines infected with equine arteritis virus

Equine arteritis virus (EAV) induces apoptosis in infected cells. Cell death caused by EAV has been studied mainly using three cell lines, BHK-21, RK-13 and Vero cells. The mechanism of apoptosis varies among cell lines and results cannot be correlated owing to differences in EAV strains used. We evaluated different markers for apoptosis in BHK-21, RK-13 and Vero cell lines using the Bucyrus EAV reference strain. Acridine orange/ethidium bromide staining revealed morphological changes in infected cells, while flow cytometry indicated the extent of apoptosis. We also observed DNA fragmentation, but the DNA ladder was detected at different times post-infection depending on the cell line, i.e., 48, 72 and 96 h post-infection in RK-13, Vero and BHK-21 cells, respectively. Measurement of viral titers obtained with each cell line indicated that apoptosis causes interference with viral replication and therefore decreased viral titers. As an unequivocal marker of apoptosis, we measured the expression of caspase-3 and caspases-8 and -9 as extrinsic and intrinsic markers of apoptosis pathways, respectively. Caspase-8 in BHK-21 cells was the only protease that was not detected at any of the times assayed. We found that Bucyrus EAV strain exhibited a distinctive apoptosis pathway depending on the cell line.     

BAR the door: cancer suppression by amphiphysin-like genes

The evolutionarily conserved amphiphysin-like genes Bin1 and Bin3 function in membrane and actin dynamics, cell polarity, and stress signaling. Recent genetic studies in mice discriminate non-essential roles in endocytic processes commonly ascribed to amphiphysins from essential roles in cancer suppression. Bin1 acts in default pathways of apoptosis and senescence that are triggered by the Myc and Raf oncogenes in primary cells, and Bin1 gene products display a 'moonlighting function' in the nucleus where a variety of other 'endocytic' proteins are also found. Together, genetic investigations in yeast, flies, and mice suggest that amphiphysin-like adapter proteins may suppress cancer by helping integrate cell polarity signals generated by actin and vesicle dynamics with central regulators of cell cycle arrest, apoptosis, and immune surveillance.     

Conformational analysis of genotoxic benzo[a]pyrene-7,8-dione-duplex DNA adducts using a molecular dynamics method (II)

The conformations of the benzo[a]pyrene-7,8-quinone (BPQ) modified oligonucleotide were investigated using molecular dynamic simulation. In the initial structures, the central guanine base was modified with BPQ resulting in the formation of four structurally distinguishable 10-(N2-deoxyguanosyl)-9,10-dihydro-9-hydroxy benzo[a]pyrene-7,8-dione adducts (BPQ-G3,4). Each of the oligonucleotide adduct consisted of two conformers, namely syn and anti conformations, depending on the rotation around the glycosidic bond between BPQ and the guanine base. The results revealed that the BPQ moiety was located in the major groove for all four syn conformers. The relative energies of these conformers were high, and the backbone largely deviated from the B-form. On the other hand, BPQ was located in the minor groove with relatively low energies, and backbone was retained in all of the anti conformer cases. The most conceivable BPQ-modified double stranded oligonucleotide structure was proposed from the energy calculation and the structural analysis.