Regulation of surfactant proteins by LPS and proinflammatory cytokines in fetal and newborn lung

Intra-amniotic lipopolysaccharide (LPS) and cytokines may decrease respiratory distress syndrome (RDS) and increase chronic lung disease in the newborn. The aim was to identify the primary inflammatory mediators regulating the expression of surfactant proteins (SP) in explants from immature (22-day-old fetus) and mature (30-day term fetus and 2-day-old newborn) rabbits. In immature lung, interleukin (IL)-1alpha and IL-1beta upregulated the expression of SP-A and SP-B. These effects of IL-1 were diminished, and SP-C mRNA was suppressed additively in the presence of tumor necrosis factor (TNF)-alpha and either LPS or interferon (IFN)-gamma. LPS, TNF-alpha, or IFN-gamma had no effect alone. In explants from the term fetus and the newborn, LPS, IL-1alpha, and TNF-alpha additively suppressed the SPs. LPS acutely induced IL-1alpha in alveolar macrophages in mature lung but not in the immature lung. IFN-gamma that generally has low expression in intrauterine infection decreased the age dependence of the other agonists' effects on SPs. The present study serves to explain the variation of the pulmonary outcome after an inflammatory insult. We propose that IL-1 from extrapulmonary sources induces the SPs in premature lung and is responsible for the decreased risk of RDS in intra-amniotic infection.     

Isolation,patch size and matrix effects on bird assemblages in forest reserves

Habitat fragmentation is one of the most studied topics in ecology but our knowledge is still limited particularly concerning matrix effects on species distribution in a human-dominated landscape. We tested the ability of random sampling hypothesis, colonization–extinction dynamics and matrix-related concepts to explain the variation in species richness, total bird density and community composition in old-forest bird assemblages in two contrasting landscapes. We collected data on breeding bird abundances from 66 old-growth forest reserves in NE Finland and six larger areas in adjacent Russian Karelia using the line transect method. In Finland, protected old-forest patches are embedded in a matrix dominated by young regeneration stands. In Russia, study areas were situated in continuous, old forest dominated landscapes. Bird assemblages in old-forest patches embedded in human-modified matrix in Finland were not random samples from Russian bird assemblages. In the Finnish assemblages, species richness was lower and total bird density higher. Species richness declined with increasing distance (isolation) to Russia. Bird assemblages in large forest reserves in Finland close to Russia were structurally more similar to assemblages in the continuous reference landscape than those in small and more distant reserves. The results support the idea that several mechanisms related to colonisation–extinction dynamics and to matrix resource availability influence species distribution in fragmented landscapes but in species-specific ways. We conclude that even though small and isolated protected areas may foster high relative bird species density their ecological integrity is compromised, and therefore, improving matrix quality around reserves may lead to considerable conservation benefits.     

Algorithmic single‐locus species delimitation: effects of sampling effort,variation and nonmonophyly in four methods and 1870 species of beetles

The vast number of undescribed species and the fast rate of biodiversity loss call for new approaches to speed up alpha taxonomy. A plethora of methods for delimiting species or operational taxonomic units (OTUs) based on sequence data have been published in recent years. We test the ability of four delimitation methods (BIN, ABGD, GMYC, PTP) to reproduce established species boundaries on a carefully curated DNA barcode data set of 1870 North European beetle species. We also explore how sampling effort, intraspecific variation, nearest neighbour divergence and nonmonophyly affect the OTU delimitations. All methods produced approximately 90% identity between species and OTUs. The effects of variation and sampling differed between methods. ABGD was sensitive to singleton sequences, while GMYC showed tendencies for oversplitting. The best fit between species and OTUs was achieved using simple rules to find consensus between discordant OTU delimitations. Using several approaches simultaneously allows the methods to compensate for each other's weaknesses. Barcode‐based OTU‐picking is an efficient way to delimit putative species from large data sets where the use of more sophisticated methods based on multilocus or genomic data is not feasible.     

Multi‐generational long‐distance migration of insects: studying the painted lady butterfly in the Western Palaearctic

Long‐range, seasonal migration is a widespread phenomenon among insects, allowing them to track and exploit abundant but ephemeral resources over vast geographical areas. However, the basic patterns of how species shift across multiple locations and seasons are unknown in most cases, even though migrant species comprise an important component of the temperate‐zone biota. The painted lady butterfly Vanessa cardui is such an example; a cosmopolitan continuously‐brooded species which migrates each year between Africa and Europe, sometimes in enormous numbers. The migration of 2009 was one of the most impressive recorded, and thousands of observations were collected through citizen science programmes and systematic entomological surveys, such as high altitude insect‐monitoring radar and ground‐based butterfly monitoring schemes. Here we use V. cardui as a model species to better understand insect migration in the Western Palaearctic, and we capitalise on the complementary data sources available for this iconic butterfly. The migratory cycle in this species involves six generations, encompassing a latitudinal shift of thousands of kilometres (up to 60 degrees of latitude). The cycle comprises an annual poleward advance of the populations in spring followed by an equatorward return movement in autumn, with returning individuals potentially flying thousands of kilometres. We show that many long‐distance migrants take advantage of favourable winds, moving downwind at high elevation (from some tens of metres from the ground to altitudes over 1000 m), pointing at strong similarities in the flight strategies used by V. cardui and other migrant Lepidoptera. Our results reveal the highly successful strategy that has evolved in these insects, and provide a useful framework for a better understanding of long‐distance seasonal migration in the temperate regions worldwide.     

Maternal coding variants in complement receptor 1 and spontaneous idiopathic preterm birth

Preterm birth (PTB) is a major global public health concern. However, little is known about the pathophysiology of spontaneous idiopathic PTB. We tested the hypothesis that rare variants in families would target specific genes and pathways that contribute to PTB risk in the general population. Whole-exome sequencing was performed on 10 PTB mothers from densely affected families including two mother–daughter pairs. We identified novel variants shared between the two mother–daughter pairs when compared to a 1000 Genomes Project background exome file and investigated these genes for pathway aggregation using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Genes in enriched pathways were then surveyed in the other six PTB exomes and tested for association in a larger number of nuclear families. The KEGG complement and coagulation cascade was one of the most enriched pathways in our two mother–daughter pairs. When the six genes found in this pathway (CFH, CR1, F13B, F5, CR2, and C4BPA) were examined for novel missense variants, half of all the exomes harbored at least one. Association analysis of variants in these six gene regions in nuclear families from Finland (237 cases and 328 controls) found statistically significant associations after multiple test corrections in three CR1 SNPs; the strongest in an exonic missense SNP, rs6691117, p value = 6.91e?5, OR = 1.71. Our results demonstrate the importance of the complement and coagulation cascades in the pathophysiology of PTB, and suggest potential screening and intervention approaches to prevent prematurity that target this pathway.     

Diverse mechanisms of metaeffector activity in an intracellular bacterial pathogen,Legionella pneumophila

Pathogens deliver complex arsenals of translocated effector proteins to host cells during infection, but the extent to which these proteins are regulated once inside the eukaryotic cell remains poorly defined. Among all bacterial pathogens, Legionella pneumophila maintains the largest known set of translocated substrates, delivering over 300 proteins to the host cell via its Type IVB, Icm/Dot translocation system. Backed by a few notable examples of effector–effector regulation in L. pneumophila, we sought to define the extent of this phenomenon through a systematic analysis of effector–effector functional interaction. We used Saccharomyces cerevisiae, an established proxy for the eukaryotic host, to query > 108,000 pairwise genetic interactions between two compatible expression libraries of ~330 L. pneumophila‐translocated substrates. While capturing all known examples of effector–effector suppression, we identify fourteen novel translocated substrates that suppress the activity of other bacterial effectors and one pair with synergistic activities. In at least nine instances, this regulation is direct—a hallmark of an emerging class of proteins called metaeffectors, or “effectors of effectors”. Through detailed structural and functional analysis, we show that metaeffector activity derives from a diverse range of mechanisms, shapes evolution, and can be used to reveal important aspects of each cognate effector's function. Metaeffectors, along with other, indirect, forms of effector–effector modulation, may be a common feature of many intracellular pathogens—with unrealized potential to inform our understanding of how pathogens regulate their interactions with the host cell.     

Proteomic changes in articular cartilage of human endemic osteoarthritis in China

Kashin-Beck disease (KBD) is a chronic endemic osteochondropathy with unclear pathogenesis. It is a degenerative disease similar to osteoarthritis, but with different manifestations of cartilage damage. The aim of this investigation was to show the protein changes in KBD cartilage and to identify the candidate proteins in order to understand the pathogenesis of the disease. Proteins were extracted from the media of primary cell cultures of KBD and normal chondrocytes, and separated by two-dimensional fluorescence difference gel electrophoresis (2-D DIGE). MALDI-TOF/TOF analysis revealed statistically significant differences in 27 proteins from KBD chondrocyte cultures, which consisted of 17 up-regulated and ten down-regulated proteins. The results were further validated by Western blot analysis. The proteins identified are mainly involved in cellular redox homeostasis and stress response (MnSOD, Hsp27, Peroxiredoxin-1, and Cofilin-1), glycolysis (PGK-1, PGM-1, α-enolase), and cell motility and cytoskeletal organization (Actin, Calponin-2, and Keratin). These KBD-associated proteins indicate that cytoskeletal remodeling, glycometabolism, and oxidative stress are abnormal in KBD articular cartilage.     

Hydrolytic Reactions of 3′-Deoxy-3′-thioinosylyl-(3′→ >5′)-uridine; An RNA Dinucleotide Containing a 3′-S-Phosphorothiolate Linkage

Abstract

The course of hydrolysis of 3′-deoxy-3′-thioinosylyl-(3′ → 5′)-uridine (IspU) has been followed by HPLC over a wide pH-range. Two reactions of the internucleosidic thiophosphate linkage compete: (i) cleavage yielding thioinosine monophosphates and uridine, and (ii) isomerization to the 2′,5′-isomer of IspU. Under very acidic conditions, even acid-catalyzed depurination of the inosine moiety is observed. The stability of the thiophosphate linkage and the mechanisms of its rupture are discussed.     

The role of Delta(9)-desaturase in the production of cis-9, trans-11 CLA

Biomedical studies with animal models have demonstrated that cis-9, trans-11 conjugated linoleic acid (CLA), the predominant isomer found in milk fat from dairy cows, has anticarcinogenic effects. We recently demonstrated endogenous synthesis of cis-9, trans-11 CLA from ruminally derived trans-11 C18:1 by Delta(9)-desaturase in lactating dairy cows. The present study further examined endogenous synthesis of cis-9, trans-11 CLA and quantified its importance by increasing substrate supply using partially hydrogenated vegetable oil (PHVO) as a source of trans-11 C18:1 and blocking endogenous synthesis using sterculic oil (SO) as a source of cyclopropene fatty acids which specifically inhibit Delta(9)-desaturase. Four cows were abomasally infused with 1) control, 2) PHVO, 3) SO, and 4) PHVO+SO in a 4 x 4 Latin square design. With infusion of PHVO, cis-9, trans-11 CLA was increased by 17% in milk fat. Consistent with inhibition of desaturase, SO treatments increased milk fat ratios for the fatty acid pairs effected by Delta(9)-desaturase, C14:0/cis-9 C14:1, C16:0/cis-9 C16:1, and C18:0/cis-9 C18:1. The role of endogenous synthesis of CLA was evident from the 60-65% reduction in cis-9, trans-11 CLA which occurred in milk fat with SO treatments. cis-9 C14:1 originates from desaturation of C14:0 by Delta(9)-desaturase and can be used to estimate the extent of SO inhibition of Delta(9)-desaturase. When this correction factor was applied, endogenous synthesis was estimated to account for 78% of the total cis-9, trans-11 CLA in milk fat. Thus, endogenous synthesis was the major source of cis-9, trans-11 CLA in milk fat of lactating cows.