MIF is among the proinflammatory cytokines increased by LPS in the human trophoblast line

Infection is increasingly considered to contribute to pathological conditions in pregnancy. The placenta acts as a protective immunological fetomaternal barrier which recognizes microbes by pattern recognition receptors on the trophoblast. Lipopolysaccharide (LPS) is a cell wall constituent of Gram-negative bacteria that elicits a strong immune response. In this study, LPS from E. coli was used to treat the HTR-8/SVneo trophoblast cell line and examine its influence on cytokines IL-6, IL-8 and MIF using real-time PCR, metalloproteinases (MMP)-2 and -9 by gelatin zymography, and Western analysis of integrin subunits ?1 and ?1, all known to contribute to migration of human trophoblasts in vitro. The results described herein for the first time, show that MIF mRNA and secreted MIF protein were significantly elevated (2.5-3- and 2-fold, respectively) in LPS-treated cells. MMP-2 and MMP-9 levels were increased, as well as cell migration, as judged by a wound-healing test, however, no changes in the studied integrin subunits, cell viability or cell numbers were observed. The data obtained furthers our understanding of LPS actions on the trophoblast in vitro, additionally implicate MIF, and suggest that infection in vivo could indeed alter the functional characteristics of the trophoblast.

Wood traits in parental and hybrid species of Sorbus

The genus Sorbus is an example of taxonomic complexity arising from the combined effects of hybridization, polyploidy, and apomixis. In this study, a comparison of the diagnostic microscopic characteristics of wood, together with the quantitative traits of vascular anatomy, fiber morphology, and cell wall constituents in parental ( Sorbus aria , Sorbus aucuparia , Sorbus chamaemespilus ) and hybrid ( Sorbus haljamovae , Sorbus montisalpae , Sorbus zuzanae ) taxa, was undertaken to discriminate each one of the examined taxa from the other and also to examine relatedness among parental and hybrid taxa. Chemical profiles of the degree of polymerization of cellulose were found to be the discriminating chemotaxonomic marker for all taxa. Sorbus haljamovae was determined to be the only taxon distinctively identified microscopically and distinguishable from the other examined taxa. The use of cell wall constituent traits provided a better segregation of hybrid taxa from their putative parental species than did the application of vascular anatomy variables. Sorbus zuzanae and Sorbus haljamovae formed isolated clusters that were distinctively segregated from all the other examined taxa. The results of this study indicate that the majority of wood traits in Sorbus hybrids do not exhibit an intermediate position between the parental taxa.

Origin of the Biomechanical Properties of Wood Related to the Fine Structure of the Multi-layered Cell Wall

In this study, a basic model is introduced to describe the biomechanical properties of the wood from the viewpoint of the composite structure of its cell wall. First, the mechanical interaction between the cellulose microfibril (CMF) as a bundle framework and the lignin-hemicellulose as a matrix (MT) skeleton in the secondary wall is formulated based on “the two phase approximation.” Thereafter, the origins of (1) tree growth stress, (2) shrinkage or swelling anisotropy of the wood, and (3) moisture dependency of the Young’s modulus of wood along the grain were simulated using the newly introduced model. Through the model formulation; (1) the behavior of the cellulose microfibril (CMF) and the matrix substance (MT) during cell wall maturation was estimated; (2) the moisture reactivity of each cell wall constituent was investigated; and (3) a realistic model of the fine composite structure of the matured cell wall was proposed. Thus, it is expected that the fine structure and internal property of each cell wall constituent can be estimated through the analyses of the macroscopic behaviors of wood based on the two phase approximation.

Pir1p Mediates Translocation of the Yeast Apn1p Endonuclease into the Mitochondria To Maintain Genomic Stability

ABSTRACT The mitochondrial genome is continuously subject to attack by reactive oxygen species generated through aerobic metabolism. This leads to the formation of a variety of highly genotoxic DNA lesions, including abasic sites. Yeast Apn1p is localized to the nucleus, where it functions to cleave abasic sites, and apn1 Δ mutants are hypersensitive to agents such as methyl methanesulfonate (MMS) that induce abasic sites. Here we demonstrate for the first time that yeast Apn1p is also localized to the mitochondria. We found that Pir1p, initially isolated as a cell wall constituent of unknown function, interacts with the C-terminal end of Apn1p, which bears a bipartite nuclear localization signal. Further analysis revealed that Pir1p is required to cause Apn1p mitochondrial localization, presumably by competing with the nuclear transport machinery. pir1Δ mutants displayed a striking (∼3-fold) increase of Apn1p in the nucleus, which coincided with drastically reduced levels in the mitochondria. To explore the functional consequences of the Apn1p-Pir1p interaction, we measured the rate of mitochondrial mutations in the wild type and pir1Δ and apn1Δ mutants.pir1Δ and apn1Δ mutants exposed to MMS exhibited 3.6- and 5.8-fold increases, respectively, in the rate of mitochondrial mutations, underscoring the importance of Apn1p in repair of the mitochondrial genome. We conclude that Pir1p interacts with Apn1p, at the level of either the cytoplasm or nucleus, and facilitates Apn1p transport into the mitochondria to repair damaged DNA.

Endotoxin binding to platelets in blood from patients with a sepsis syndrome

Endotoxin, the lipopolysaccharide cell wall constituent of Gram-negative bacteria, produces symptoms of the Gram-negative sepsis syndrome. By measuring endotoxin in blood from septic patients it may be possible to select a subpopulation of patients in which mortality can be prevented by treatment with anti-endotoxin antibodies. We evaluated the performance of an endotoxin-free blood-collection tube. Within-run and between-run CVs of our endotoxin assay were 4-18% and 8-20%, respectively. In endotoxin-positive samples (LPS > or = 6 ng/L), the concentration of endotoxin in platelet-rich plasma was significantly higher (P < 0.001) than in platelet-poor plasma. Apparent binding of endotoxin to platelets ranged from 0% to 92%. The correlation between the apparent percentage binding of LPS to platelets and the platelet count in platelet-rich plasma is linear and positive, but LPS is not bound solely to platelets. We conclude that endotoxin must be measured in platelet-rich plasma.

Cellulase-gold labelling of cellulose in forages

Current fiber analyses provide information on the chemical and structural composition of the fiber as a whole. However, these techniques do not offer insight into the compositional and structural differences between specific fiber tissues which may affect digestibility. The purpose of this study was to: (1) ultrastructurally localize one cell wall constituent, cellulose, in four forages; and (2) apply this technique as a tool for the evaluation of biodegradation in forages.Insoluble fibers were prepared using a modified AOAC Total Dietary Fiber Technique. Two millimeter sections cut from leaflets of alfalfa (Medicago sativa L.) and 1-76 1espedeza [Sericea cuneata (Dumont)] and leaves of coastal bermudagrass (Cynodon dactylon L. Pers.) and orchardgrass (Dactylis glomerata L.) were incubated stepwise with: (1) α-amylase, pH 6.0 for ½ h at 100°C; (2) protease, pH 7.5 for ½ h at 60°C; (3) amyloglucosidase, pH 4.5 for ½ h at 60°C, and (4) 1% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0 for 24 h at 37°C.

Biodegradability of mature grass cell walls in relation to chemical composition and rumen microbial activity

SummaryCell walls from mature stems of three tropical grass species (Digitaria decumbens(pangola),Setaria anceps(cv. Kazangula) and sugar cane), and temperate barley straw, were analysed for lignin, carbohydrate, and the maj or acyl groups ferulate, ρ-coumarate and acetate. Samples were incubated in nylon bags in the rumen of sheep in a 4 x 4 latin-square design, and rates of disappearance of cellulose, hemicellulose, xylose, arabinose, ferulate, ρ-coumarate and acetate were determined during 60 h incubation. Interspecies differences in cell-wall chemistry appeared largely in the variable degree of acylation with p-coumaric acid (1·0–3·3%) and acetate (0·5–3·6%), and the high glucose concentration in the hemicellulose from pangola (17%) andSetaria(9%). Barley had much lower concentrations of these components than the tropical species. After 24 h incubation, losses of cellulose and acyl groups were greatest from pangola, whereas hemicellulose and its major components xylose and arabinose were degraded to the greatest degree from barley straw.Setariacell-wall components were generally more resistant to degradation than the other species. No relationship was found between the concentration of any cell-wall constituent and degradability measurements. Nor were changes in microbial population, indicated by measuring the accumulation of cystine on the fibres, related to the rate or degree of degradation of any of the measured cell-wall constituents. Lignin was fractionated with alkali into insoluble and soluble fractions. The latter (25–50% of original lignin) gave high interspecies correlations with the degradability of total hemicellulose and its component monosaccharides. It was concluded that variability in the biodegradability of the cell walls was more likely due toin situstructural features, such as cross-linking between polymers, than to the concentration of any particular cell-wall constituent.

Utilization of low-quality roughage by Bos taurus and Bos indicus cattle

1. Six Hereford and six Brahman steers were fed ad lib. Pangola grass (Digztaria decumbens) and Spear grass (Heteropogon contortus) hay alone and supplemented with rumen-degradable nitrogen and sulphur and minerals. The rumen digestion of the two feeds was determined by reference to the disappearance of substrate from nylon bags suspended in the rumen and withdrawn after intervals ranging from 8 to 120 h.2. The digestion of the unsupplemented Pangola grass diet occurred more rapidly in Brahmans than in Herefords and was associated with higher rumen ammonia concentrations in Brahmans (40 v. 16 mg/l). The rumen NH3, concentrations were increased to over 100 mg/l by supplementation. The digestion rate increased in both breeds after supplementation and the breed difference disappeared. Increases in digestion rate were not achieved above NH3, concentrations of 60–80 mg/l.3. Spear grass, especially the cell-wall-constituent fraction, was more resistant to digestion than Pangola grass. Digestion of the unsupplemented Spear grass diet proceeded more rapidly in Brahmans than in Herefords. The digestion rate in Brahmans were similar irrespective of whether the diet was supplemented or not. Supplementation increased digestion rate in Herefords.