Seroepidemiologic Survey of Crimean-Congo Hemorrhagic Fever Virus in Logging Communities, Myanmar.

Crimean-Congo hemorrhagic fever virus (CCHFV) is endemic in Asia, infecting many animal hosts, but CCHFV has not been reported in Myanmar. We conducted a seroepidemiologic survey of logging communities in Myanmar and found CCHFV exposure was common (9.8%) and exposure to wild animal blood and body fluids was associated with seropositivity.

Elevated nuclear sphingoid base-1-phosphates and decreased histone deacetylase activity after fumonisin B1 treatment in mouse embryonic fibroblasts.

Fumonisin B1 (FB1) is a mycotoxin produced by a common fungal contaminant of corn. Administration of FB1 to pregnant LM/Bc mice induces exencephaly in embryos, and ingestion of FB1-contaminated food during early pregnancy is associated with increased risk for neural tube defects (NTDs) in humans. FB1 inhibits ceramide synthase enzymes in sphingolipid biosynthesis, causing sphinganine (Sa) and bioactive sphinganine-1-phosphate (Sa1P) accumulation in blood, cells, and tissues. Sphingosine kinases (Sphk) phosphorylate Sa to form Sa1P. Upon activation, Sphk1 associates primarily with the plasma membrane, while Sphk2 is found predominantly in the nucleus. In cells over-expressing Sphk2, accumulation of Sa1P in the nuclear compartment inhibits histone deacetylase (HDAC) activity, causing increased acetylation of histone lysine residues. In this study, FB1 treatment in LM/Bc mouse embryonic fibroblasts (MEFs) resulted in significant accumulation of Sa1P in nuclear extracts relative to cytoplasmic extracts. Elevated nuclear Sa1P corresponded to decreased histone deacetylase (HDAC) activity and increased histone acetylation at H2BK12, H3K9, H3K18, and H3K23. Treatment of LM/Bc MEFs with a selective Sphk1 inhibitor, PF-543, or with ABC294640, a selective Sphk2 inhibitor, significantly reduced nuclear Sa1P accumulation after FB1, although Sa1P levels remained significantly increased relative to basal levels. Concurrent treatment with both PF-543 and ABC294640 prevented nuclear accumulation of Sa1P in response to FB1. Other HDAC inhibitors are known to cause NTDs, so these results suggest that FB1-induced disruption of sphingolipid metabolism leading to nuclear Sa1P accumulation, HDAC inhibition, and histone hyperacetylation is a potential mechanism for FB1-induced NTDs.

Increased sphingoid base-1-phosphates and failure of neural tube closure after exposure to fumonisin or FTY720.

BACKGROUND: Fumonisin B(1) (FB(1)) is a mycotoxin produced by a common fungal contaminant of corn. Ingestion of FB(1)-contaminated food is associated with increased risk for neural tube defects (NTDs). FB(1) induces NTDs in inbred LM/Bc mice. FB(1) inhibits ceramide synthase in de novo sphingolipid biosynthesis, resulting in accumulation of sphinganine and sphinganine-1-phosphate (Sa1P). Sa1P functions as a ligand for a family of G protein-coupled S1P receptors. METHODS: Pregnant SWV and LM/Bc mice were treated with FB(1) (20 mg/kg/day intraperitoneally on embryonic day (ED) 7.5-8.5) or the known S1P receptor agonist FTY720 (10 mg/kg/day oral gavage on ED 6.5-8.5). LC/MS was used to detect sphingoid base-1-phosphates in maternal blood spots, plasma, and embryonic tissue. Strain-specific SWV and LM/Bc mouse embryonic fibroblasts (MEFs) and serum free mouse embryo (SFME) neural progenitor cells were treated with FB(1) (40 µM for 24 hr) and LC/MS was used to detect sphingoid base-1-phosphates. RESULTS: FTY720 induced NTDs in both the SWV and the LM/Bc strains of mice. Sphinganine-1-P (Sa1P) and FTY720-P were elevated in the blood spots and plasma of mice treated with FB(1) or FTY720, respectively. FTY720-P was elevated in ED 9.5 exencephalic embryos. Sa1P was elevated in SFME and MEF cells treated with FB(1), and Sa1P was higher in MEFs generated from the FB(1)-NTD-susceptible LM/Bc strain. CONCLUSIONS: Elevated sphingoid base-1-P after FB(1) or FTY720 suggest a potential role for these bioactive lipid ligands and activation of S1P receptor signaling pathways in the failure of neural tube closure after FB(1) or FTY720. Sa1P may represent a biomarker for FB(1)-NTD risk assessment.

Predicting the potential for zoonotic transmission and host associations for novel viruses.

Host-virus associations have co-evolved under ecological and evolutionary selection pressures that shape cross-species transmission and spillover to humans. Observed virus-host associations provide relevant context for newly discovered wildlife viruses to assess knowledge gaps in host-range and estimate pathways for potential human infection. Using models to predict virus-host networks, we predicted the likelihood of humans as hosts for 513 newly discovered viruses detected by large-scale wildlife surveillance at high-risk animal-human interfaces in Africa, Asia, and Latin America. Predictions indicated that novel coronaviruses are likely to infect a greater number of host species than viruses from other families. Our models further characterize novel viruses through prioritization scores and directly inform surveillance targets to identify host ranges for newly discovered viruses.

Reproductive Techniques for Ovarian Monitoring and Control in Amphibians.

Ovarian control and monitoring in amphibians require a multi-faceted approach. There are several applications that can successfully induce reproductive behaviors and the acquisition of gametes and embryos for physiological or molecular research. Amphibians contribute to one-quarter to one-third of vertebrate research, and of interest in this context is their contribution to the scientific community's knowledge of reproductive processes and embryological development. However, most of this knowledge is derived from a small number of species. In recent times, the decimation of amphibians across the globe has required increasing intervention by conservationists. The captive recovery and assurance colonies that continue to emerge in response to the extinction risk make existing research and clinical applications invaluable to the survival and reproduction of amphibians held under human care. The success of any captive population is founded on its health and reproduction and the ability to develop viable offspring that carry forward the most diverse genetic representation of their species. For researchers and veterinarians, the ability to monitor and control ovarian development and health is, therefore, imperative. The focus of this article is to highlight the different assisted reproductive techniques that can be used to monitor and, where appropriate or necessary, control ovarian function in amphibians. Ideally, any reproductive and health issues should be reduced through proper captive husbandry, but, as with any animal, issues of health and reproductive pathologies are inevitable. Non-invasive techniques include behavioral assessments, visual inspection and palpation and morphometric measurements for the calculation of body condition indices and ultrasound. Invasive techniques include hormonal injections, blood sampling, and surgery. Ovarian control can be exercised in a number of ways depending on the application required and species of interest.

Elevated Nuclear and Cytoplasmic FTY720-Phosphate in Mouse Embryonic Fibroblasts Suggests the Potential for Multiple Mechanisms in FTY720-Induced Neural Tube Defects.

FTY720 (fingolimod) is a U.S. Food and Drug Administration-approved drug to treat relapsing remitting multiple sclerosis. FTY720 treatment in pregnant inbred LM/Bc mice results in approximately 60% of embryos having a neural tube defect (NTD). Sphingosine kinases (Sphk1, Sphk2) phosphorylate FTY720 in vivo to form the bioactive metabolite FTY720-1-phosphate (FTY720-P). Cytoplasmic FTY720-P is an agonist for 4 of the 5 sphingosine-1-phosphate (S1P) receptors (S1P1, 3-5) and can also act as a functional antagonist of S1P1, whereas FTY720-P generated in the nucleus inhibits histone deacetylases (HDACs), leading to increased histone acetylation. This study demonstrates that treatment of LM/Bc mouse embryonic fibroblasts (MEFs) with FTY720 results in a significant accumulation of FTY720-P in both the cytoplasmic and nuclear compartments. Elevated nuclear FTY720-P is associated with decreased HDAC activity and increased histone acetylation at H3K18 and H3K23 in LM/Bc MEFs. Treatment of LM/Bc MEFs with FTY720 and a selective Sphk2 inhibitor, ABC294640, significantly reduces the amount of FTY720-P that accumulates in the nucleus. The data provide insight into the relative amounts of FTY720-P generated in the nuclear versus cytoplasmic subcellular compartments after FTY720 treatment and the specific Sphk isoforms involved. The results of this study suggest that FTY720-induced NTDs may involve multiple mechanisms, including: (1) sustained and/or altered S1P receptor activation and signaling by FTY720-P produced in the cytoplasm and (2) HDAC inhibition and histone hyperacetylation by FTY720-P generated in the nucleus that could lead to epigenetic changes in gene regulation.

Lysophosphatidic Acid Stimulates Urokinase Receptor (uPAR/CD87) in Ovarian Epithelial Cancer Cells.

BACKGROUND/AIM: Lysophosphatidic acid (LPA) is a bioactive lipid positively linked with ovarian cancer progression. The multi-functional urokinase receptor (uPAR), a cell-surface glycoprotein, binds and facilitates activation of uPA and laterally regulates integrin and tyrosine kinase receptor activities in promotion of cell migration and invasion. We hypothesized that LPA stimulates uPAR expression and activity in ovarian epithelial cancer cells. MATERIALS AND METHODS: Ovarian epithelial cancer cell lines OVCA 429 and OVCA 433 were stimulated with LPA and examined for uPAR mRNA expression and protein localization. uPA binding to OVCA plasma membranes was measured through enzymatic analysis of affinity-isolated cell-surface proteins. RESULTS: LPA drove cell-surface uPAR aggregation and mRNA expression concomitant with increased cell-surface binding of uPA. Both control and LPA-stimulated uPAR expression and uPA cell-surface association involved phosphatidylinositol 3-kinase, but not p38 or p42 mitogen-activated protein kinase, signaling. CONCLUSION: These data provide mechanistic insight into ovarian epithelial cancer cell progression by demonstrating that LPA drives uPAR expression and uPA binding.

A blood spot method for detecting fumonisin-induced changes in putative sphingolipid biomarkers in LM/Bc mice and humans.

Fumonisins (FB) are mycotoxins found in maize. They are hypothesised risk factors for neural tube defects (NTDs) in humans living where maize is a dietary staple. In LM/Bc mice, FB1-treatment of pregnant dams induces NTDs and results in increased levels of sphingoid base 1-phosphates in blood and tissues. The increased level of sphingoid base 1-phosphates in blood is a putative biomarker for FB1 inhibition of ceramide synthase in humans. Collection of blood spots on paper from finger sticks is a relatively non-invasive way to obtain blood for biomarker analysis. The objective of this study was to develop and validate in an animal model, and ultimately in humans, a method to estimate the volume of blood collected as blood spots on absorbent paper so as to allow quantification of the molar concentration of sphingoid base 1-phosphates in blood. To accomplish this objective, blood was collected from unexposed male LM/Bc and FB1-exposed pregnant LM/Bc mice and humans and applied to two types of absorbent paper. The sphingoid base 1-phosphates, absorbance at 270 nm (A270), and total protein content (Bradford) were determined in the acetonitrile:water 5% formic acid extracts from the dried blood spots. The results show that in both mouse and human the A270, total protein, and blood volume were closely correlated and the volume of blood spotted was accurately estimated using only the A270 of the extracts. In mouse blood spots, as in tissues and embryos, the FB1-induced changes in sphingolipids were correlated with urinary FB1. The half-life of FB1 in the urine was short (<24 h) and the elevation in sphingoid base 1-phosphates in blood was also short, although more persistent than the urinary FB1.

Production of male- and female-sterile plants through reproductive tissue ablation.

Male and female sterilities have many useful applications in horticultural crops, including reducing the invasive potential of new ornamentals, elimination of pollen allergens and redirecting resources from seeds to vegetative growth. In this study, we tested a male- and female-sterility (MS; FS) gene construct in Nicotiana tabacum to evaluate its effectiveness and effect on phenotype. Three T1 Nicotiana tabacum lines expressing the MS (p108:barnase) and FS (sp41:barnase) genes (MS/FS lines) and a control Nicotiana tabacum line (WT GUS) were measured for plant height, leaf length and width, corolla length, number of nodes on the main stem and stem diameter. No significant differences were found in these growth measurements between MS/FS lines and WT GUS. No pollen was observed on any of the lines carrying the MS and FS genes, indicating that the male sterility was complete. Seed set was greatly reduced or completely eliminated in plants with the MS and FS genes, after heavy pollinations of mature flowers with WT GUS pollen. However, pollinations of immature flowers resulted in very low seed set. This may be due to the nature of the promoter controlling expression of the FS gene as it had the highest expression levels at anthesis. The combination of male- and female-sterility genes was effective in eliminating seed set in all the lines examined and has direct application for reducing invasiveness of ornamental plants.