107 research outputs found
Marasmius oreades agglutinin enhances resistance of Arabidopsis against plant-parasitic nematodes and a herbivorous insect
Background Plant-parasitic nematodes and herbivorous insects have a significant negative impact on global crop production. A successful approach to protect crops from these pests is the in planta expression of nematotoxic or entomotoxic proteins such as crystal proteins from Bacillus thuringiensis (Bt) or plant lectins. However, the efficacy of this approach is threatened by emergence of resistance in nematode and insect populations to these proteins. To solve this problem, novel nematotoxic and entomotoxic proteins are needed. During the last two decades, several cytoplasmic lectins from mushrooms with nematicidal and insecticidal activity have been characterized. In this study, we tested the potential of Marasmius oreades agglutinin (MOA) to furnish Arabidopsis plants with resistance towards three economically important crop pests: the two plant-parasitic nematodes Heterodera schachtii and Meloidogyne incognita and the herbivorous diamondback moth Plutella xylostella. Results The expression of MOA does not affect plant growth under axenic conditions which is an essential parameter in the engineering of genetically modified crops. The transgenic Arabidopsis lines showed nearly complete resistance to H. schachtii, in that the number of female and male nematodes per cm root was reduced by 86-91 % and 43-93 % compared to WT, respectively. M. incognita proved to be less susceptible to the MOA protein in that 18-25 % and 26-35 % less galls and nematode egg masses, respectively, were observed in the transgenic lines. Larvae of the herbivorous P. xylostella foraging on MOA-expression lines showed a lower relative mass gain (22-38 %) and survival rate (15-24 %) than those feeding on WT plants. Conclusions The results of our in planta experiments reveal a robust nematicidal and insecticidal activity of the fungal lectin MOA against important agricultural pests which may be exploited for crop protection
Adhesive glycostrategies from opportunistic filamentous fungi
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Effect of field exposure to 38-year-old residual petroleum hydrocarbons on growth, condition index, and filtration rate of the ribbed mussel, Geukensia demissa
Author Posting. © The Author(s), 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Environmental Pollution 154 (2008): 312-319, doi:10.1016/j.envpol.2007.10.008.In September 1969, the Florida barge spilled 700,000 L of No. 2 fuel oil into the
salt marsh sediments of Wild Harbor, MA. Today a substantial amount, approximately
100 kg, of moderately degraded petroleum remains within the sediment and along
eroding creek banks. The ribbed mussels, Geukensia demissa, which inhabit the salt marsh creek bank, are exposed to the spilled oil. Examination of short-term exposure was
done with transplantation of G. demissa from a control site, Great Sippewissett marsh,
into Wild Harbor. We examined the effects of long-term exposure with transplantation of
mussels from Wild Harbor into Great Sippewissett. Both the short- and long-term
exposure transplants exhibited slower growth rates, shorter mean shell lengths, lower
condition indices, and decreased filtration rates. Our results add new knowledge about
long-term consequences of spilled oil, a dimension that should be included when
assessing oil-impacted areas and developing management plans designed to restore,
rehabilitate, or replace impacted areas.This work is the result of research sponsored by NOAA National Sea Grant
College Program Office, Department of Commerce, under Grant No. NA16RG2273,
Woods Hole Oceanographic Institution Sea Grant Project No. R/P-73. Additional support was
provided by funding from the NSF-funded Research Experience for Undergraduates
program, award 0453292, an Office of Naval Research Young Investigator Award
(N00014-04-01-0029) to C. Reddy
AXL Expression on Homeostatic Resident Liver Macrophages Is Reduced in Cirrhosis Following GAS6 Production by Hepatic Stellate Cells.
BACKGROUND & AIMS: AXL and MERTK expression on circulating monocytes modulated immune responses in patients with cirrhosis (CD14+HLA-DR+AXL+) and acute-on-chronic liver failure (CD14+MERTK+). AXL expression involved enhanced efferocytosis, sustained phagocytosis, but reduced tumor necrosis factor-α/interleukin-6 production and T-cell activation, suggesting a homeostatic function. Axl was expressed on murine airway in tissues contacting the external environment, but not interstitial lung- and tissue-resident synovial lining macrophages. We assessed AXL expression on tissue macrophages in patients with cirrhosis. METHODS: Using multiplexed immunofluorescence we compared AXL expression in liver biopsies in cirrhosis (n = 22), chronic liver disease (n = 8), non-cirrhotic portal hypertension (n = 4), and healthy controls (n = 4). Phenotype and function of isolated primary human liver macrophages were characterized by flow cytometry (cirrhosis, n = 11; control, n = 14) ex vivo. Also, AXL expression was assessed on peritoneal (n = 29) and gut macrophages (n = 16) from cirrhotic patients. Regulation of AXL expression was analyzed in vitro and ex vivo using primary hepatic stellate cells (HSCs), LX-2 cells, and GAS6 in co-culture experiments. RESULTS: AXL was expressed on resident (CD68+) but not tissue-infiltrating (MAC387+) liver macrophages, hepatocytes, HSCs, or sinusoidal endothelial cells. Prevalence of hepatic CD68+AXL+ cells significantly decreased with cirrhosis progression: (healthy, 90.2%; Child-Pugh A, 76.1%; Child-Pugh B, 64.5%; and Child-Pugh C, 18.7%; all P < .05) and negatively correlated with Model for End-Stage Liver Disease and C-reactive protein (all P < .05). AXL-expressing hepatic macrophages were CD68highHLA-DRhighCD16highCD206high. AXL expression also decreased on gut and peritoneal macrophages from cirrhotic patients but increased in regional lymph nodes. GAS6, enriched in the cirrhotic liver, appeared to be secreted by HSCs and down-regulate AXL in vitro. CONCLUSIONS: Decreased AXL expression on resident liver macrophages in advanced cirrhosis, potentially in response to activated HSCs-secreted GAS6, suggests a role for AXL in the regulation of hepatic immune homeostasis
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1ÎČ, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1ÎČ innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
The yeast actin intron contains a cryptic promoter that can be switched on by preventing transcriptional interference.
We show that the single intron of the actin gene of the yeast Saccharomyces cerevisiae contains a cryptic promoter for transcription of the second exon. This promoter is inactive in the normal actin gene, but can be activated when the actin gene promoter is deleted. An identical activation was induced by placing efficient transcriptional terminators at position 61 of the 309 bp intron. In all cases transcripts with identical 5' ends close to the boundary of the intron and the second exon were produced. These results indicate that the cryptic promoter in the actin intron is occluded in the normal actin gene by transcriptional interference with the actin gene promoter. Transcription initiation near the intron/exon 2 boundary is enabled by protection from traversing polymerases, that initiated transcription at the upstream located actin gene promoter. A partial promoter protection using leaky terminators resulted in small amounts of transcripts initiated from the cryptic promoter. Although we do not know any function of the cryptic promoter in actin gene expression, it is tentative to speculate that the cryptic intron promoter might be a relict of a promoter that was functional earlier in evolution
Digestibility, nitrogen utilization and milk fatty acid profile of dairy cows fed hay from species rich mountainous grasslands with elevated herbal and phenolic contents
In the present study, the influence of mountain hay diets with elevated proportions of herbs and phenolic contents on nitrogen utilization and milk fatty acid profile of dairy cows was investigated. Two grass hay-based diets, either low or high in nitrogen (N) content (GNâ, GN+) and similar in fiber content and lignification, and two diets consisting of hays with high proportion of herbs (H) with either low or high phenolic (P) content (HPâ, HP+) were fed isoenergetically and without concentrate. All diets contained a Lolium perenne dominated basal hay and experimental hay in proportions of 0.45:0.55, except for diet GN+ (0.80:0.20) with excessive N. Feed intake, milk yield and total amount of feces and urine were recorded and sampled from 24 multiparous mid-lactation cows (eight Brown Swiss, 16 Holstein) producing on average 33 kg/ day of energy-corrected milk. The experiment was performed in three runs with two cows per diet. Data was analyzed by a general linear model considering diet and run as effects. Intake was highest in GN+ and HP+ and lower with GNâ and HPâ. No condensed tannins (CT) were detected in GNâ and GN+. Intake of phenolic compounds (g/day per cow) was high in HP+ (402) lower with HPâ (302) and lowest with GNâ and GN+ (ca. 190). The intake of CT was higher in HP+ (115 g/day) compared to HPâ (31 g/day). Yield of milk and energy-corrected milk as well as gross milk constituents were not affected by diet. Apparent total tract nutrient digestibility was higher for the grass-based diets (GNâ, GN+) than for the diets with high herbal proportion (HPâ, HP+). With GN+, absolute urinary N losses and those in proportion of total excreta N were higher than in the other diets and was lowest with HP+. Utilization of N was lower with GN+ and HP+ compared to HPâ. The milk fat of cows fed HP+ had higher proportions of polyunsaturated fatty acids compared to that of GNâ. The transfer rate of C18:3 n-3 from feed to milk was highest for the two herbal hay diets. The secretion of C18:1 t11 in relation to the amount of C18:2 n-6 + C18:3 n-3 ingested was highest for diet HPâ. In conclusion, mountain hay rich in herbs was found to be a dietary means to lower the N emission potential of the manure by lower urinary N excretion demonstrating that inclusion of herbs into grasslands may be beneficial
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