DDESC: Dragon database for exploration of sodium channels in human

Background

Hepcidin/LEAP-1 is an iron regulatory hormone originally identified as an antimicrobial peptide. As part of a systematic analysis of the evolution of host defense peptides in primates, we have sequenced the orthologous gene from 14 species of non-human primates.

Results

The sequence of the mature peptide is highly conserved amongst all the analyzed species, being identical to the human one in great apes and gibbons, with a single residue conservative variation in Old-World monkeys and with few substitutions in New-World monkeys.

Conclusion

Our analysis indicates that hepcidin's role as a regulatory hormone, which involves interaction with a conserved receptor (ferroportin), may result in conservation over most of its sequence, with the exception of the stretch between residues 15 and 18, which in New-World monkeys (as well as in other mammals) shows a significant variation, possibly indicating that this structural region is involved in other functions.     

Elastase-Dependent Live Attenuated Swine Influenza A Viruses Are Immunogenic and Confer Protection against Swine Influenza A Virus Infection in Pigs

Influenza A viruses cause significant morbidity in swine, resulting in a substantial economic burden. Swine influenza virus (SIV) infection also poses important human public health concerns. Vaccination is the primary method for the prevention of influenza virus infection. Previously, we generated two elastase-dependent mutant SIVs derived from A/Sw/Saskatchewan/18789/02(H1N1): A/Sw/Sk-R345V (R345V) and A/Sw/Sk-R345A (R345A). These two viruses are highly attenuated in pigs, making them good candidates for a live-virus vaccine. In this study, the immunogenicity and the ability of these candidates to protect against SIV infection were evaluated in pigs. We report that intratracheally administrated R345V and R345A induced antigen-specific humoral and cell-mediated immunity characterized by increased production of immunoglobulin G (IgG) and IgA antibodies in the serum and in bronchoalveolar lavage fluid, high hemagglutination inhibition titers in serum, an enhanced level of lymphocyte proliferation, and higher numbers of gamma interferon-secreting cells at the site of infection. Based on the immunogenicity results, the R345V virus was further tested in a protection trial in which pigs were vaccinated twice with R345V and then challenged with homologous A/Sw/Saskatchewan/18789/02, H1N1 antigenic variant A/Sw/Indiana/1726/88 or heterologous subtypic H3N2 A/Sw/Texas/4199-2/9/98. Our data showed that two vaccinations with R345V provided pigs with complete protection from homologous H1N1 SIV infection and partial protection from heterologous subtypic H3N2 SIV infection. This protection was characterized by significantly reduced macroscopic and microscopic lung lesions, lower virus titers from the respiratory tract, and lower levels of proinflammatory cytokines. Thus, elastase-dependent SIV mutants can be used as live-virus vaccines against swine influenza in pigs.Swine influenza virus (SIV) is the causative pathogen of swine influenza, a highly contagious, acute respiratory viral disease of swine. The mortality of SIV-infected pigs is usually low, although morbidity may approach 100%. Swine influenza is characterized by sudden onset, coughing, respiratory distress, weight loss, fever, nasal discharge, and rapid recovery (38). SIV is a member of the influenza virus A genus in the Orthomyxoviridae family, and the virus has a genome consisting of eight segments of negative-sense single-stranded RNA (29). Epithelial cells in the swine respiratory tract have receptors for both avian and mammalian influenza viruses (13); thus, pigs could potentially serve as “mixing vessels” for the generation of new reassortant strains of influenza A virus that have pandemic capacity. There are a number of reports in which the direct transmission of influenza viruses from pigs to humans has been documented (6, 12, 52), and several of these cases have resulted in human fatalities (19, 35, 40, 53). Consequently, effective control of SIV would be beneficial to both humans and animals.Until 1998, classical H1N1 SIVs were the predominant isolates from pigs in the United States and Canada (5, 28). In 1997 to 1998, a dramatic change in the epidemiologic pattern of SIV began. Serological studies conducted by Olsen and colleagues in 1997 to 1998 detected a significant increase in H3-seropositive individuals, and H3N2 SIVs were isolated from pigs in both the United States and Canada (17, 54). Furthermore, reassortment between H3N2 viruses and classical H1N1 SIV resulted in the appearance of H1N2 reassortant viruses (14, 15). In addition to the isolation of H4N6 viruses, which are of duck origin, in pigs in Canada (16), wholly avian viruses of the H3N3 and H1N1 subtypes have also been isolated from Canadian pigs (18). In general, three major SIV subtypes exist, i.e., H1N1, H1N2, and H3N2, each of which has multiple genetic and antigenic variants circulating in North American swine populations (18, 28). The increased incidence of avian-like or human-like SIV reassortants raises concerns for public health and requires research devoted to the development of cross-protective SIV vaccines.Currently available swine influenza vaccines are based on inactivated whole virus of the H1N1 and H3N2 subtypes. Application of these vaccines reduces the severity of disease but does not provide consistent protection from infection (3, 22). In contrast to killed vaccines that are administered intramuscularly, intranasally administered live attenuated influenza vaccines (LAIV) induce an immune response at the site of natural infection. Therefore, an LAIV has the potential to induce broad humoral and cellular immune responses that could provide protection against antigenically different influenza viruses. LAIV based on attenuation of the virus by cold adaptation are available for humans (2) and horses (41). However, to date, no SIV LAIV are commercially available for use in swine in North America. Recent studies by Solorzano et al. showed that a mutant SIV with a truncated NS1 protein was highly attenuated in pigs (36). In addition, this SIV/NS1 LAIV was capable of stimulating a protective immune response against homologous SIVs and a partial protection against heterologous subtypic wild-type (WT) SIVs (31, 50). Stech and colleagues demonstrated that the conversion of a conserved cleavage site in the influenza virus hemagglutinin (HA) protein from a trypsin-sensitive site to an elastase-sensitive site results in in vivo attenuation of the influenza virus in mouse models (9, 37). Furthermore, these elastase-dependent LAIV were able to induce protective systemic and mucosal immune responses. Recently, we showed that two elastase-dependent SIVs derived from A/Sw/Saskatchewan/18789/02 (SIV/Sk02), R345V and R345A, are attenuated in their natural host, pigs (23). In the current study, we addressed the immunogenic and cross-protective abilities of these mutants.     

PPARγ Regulates Trophoblast Proliferation and Promotes Labyrinthine Trilineage Differentiation

Background

Abnormal trophoblast differentiation and function is the basis of many placenta-based pregnancy disorders, including pre-eclampsia and fetal growth restriction. PPARγ, a ligand-activated nuclear receptor, plays essential roles in placental development; null murine embryos die at midgestation due to abnormalities in all placental layers, in particular, small labyrinth and expanded giant cell layer. Previous studies have focused mostly on the role of PPARγ in trophoblast invasion. Based on the previously reported role of PPARγ in preadipocyte differentiation, we hypothesized that PPARγ also plays a pivotal role in trophoblast differentiation. To test this hypothesis, we report derivation of wild-type and PPARγ-null trophoblast stem (TS) cells.

Methodology/Principal Findings

PPARγ-null TS cells showed defects in both proliferation and differentiation, specifically into labyrinthine trophoblast. Detailed marker analysis and functional studies revealed reduced differentiation of all three labyrinthine lineages, and enhanced giant cell differentiation, particularly the invasive subtypes. In addition, rosiglitazone, a specific PPARγ agonist, reduced giant cell differentiation, while inducing Gcm1, a key regulator in labyrinth. Finally, reintroducing PPARγ into null TS cells, using an adenovirus, normalized invasion and partially reversed defective labyrinthine differentiation, as assessed both by morphology and marker analysis.

Conclusions/Significance

In addition to regulating trophoblast invasion, PPARγ plays a predominant role in differentiation of labyrinthine trophoblast lineages, which, along with fetal endothelium, form the vascular exchange interface with maternal blood. Elucidating cellular and molecular mechanisms mediating PPARγ action will help determine if modulating PPARγ activity, for which clinical pharmacologic agonists already exist, might modify the course of pregnancy disorders associated with placental dysfunction.     

Mutant Parkin impairs mitochondrial function and morphology in human fibroblasts

Background

Mutations in Parkin are the most common cause of autosomal recessive Parkinson disease (PD). The mitochondrially localized E3 ubiquitin-protein ligase Parkin has been reported to be involved in respiratory chain function and mitochondrial dynamics. More recent publications also described a link between Parkin and mitophagy.

Methodology/Principal Findings

In this study, we investigated the impact of Parkin mutations on mitochondrial function and morphology in a human cellular model. Fibroblasts were obtained from three members of an Italian PD family with two mutations in Parkin (homozygous c.1072delT, homozygous delEx7, compound-heterozygous c.1072delT/delEx7), as well as from two relatives without mutations. Furthermore, three unrelated compound-heterozygous patients (delEx3-4/duplEx7-12, delEx4/c.924C>T and delEx1/c.924C>T) and three unrelated age-matched controls were included. Fibroblasts were cultured under basal or paraquat-induced oxidative stress conditions. ATP synthesis rates and cellular levels were detected luminometrically. Activities of complexes I-IV and citrate synthase were measured spectrophotometrically in mitochondrial preparations or cell lysates. The mitochondrial membrane potential was measured with 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide. Oxidative stress levels were investigated with the OxyBlot technique. The mitochondrial network was investigated immunocytochemically and the degree of branching was determined with image processing methods. We observed a decrease in the production and overall concentration of ATP coinciding with increased mitochondrial mass in Parkin-mutant fibroblasts. After an oxidative insult, the membrane potential decreased in patient cells but not in controls. We further determined higher levels of oxidized proteins in the mutants both under basal and stress conditions. The degree of mitochondrial network branching was comparable in mutants and controls under basal conditions and decreased to a similar extent under paraquat-induced stress.

Conclusions

Our results indicate that Parkin mutations cause abnormal mitochondrial function and morphology in non-neuronal human cells.     

Phloemophagous and xylophagous insects, their parasitoids, predators and inquilines in the branches of the most important oak species in Serbia

Altogether 26 species of phloemophagous and xylophagous insects, 47 species of parasitoids, 14 species of predators and 7 species of inquilines were identified on the branches of Quercus cerris, Q. frainetto, Q. petraea and Q. robur, diameter 3–15 cm, at 24 sites in Serbia over the period 1992–1996. The greatest number of the identified species were taken from Q. petraea branches (66), followed by Q. cerris (49), Q. frainetto (48) and Q. robur (43). Among the identified phloemophagous and xylophagous insects, the most frequent and the most abundant species were Scolytus intricatus, Agrilus angustulus and Xylotrechus antilope. The most frequent and the most abundant parasitoid was Ecphylus silesiacus. In some samples, the species Entedon ergias, Cheiropachus quadrum and Dendrosoter protuberans were also among the more abundant parasitoids. The most significant predator was the species Tilloidea unifasciata, and the most significant inquilines were the species Poecilothrips albopictus and Asynapta pectoralis.     

Reduction of structural dimensionality through incorporation of auxiliary ligands in lanthanide tetracyanoplatinates

The synthesis of a series of lanthanide tetracyanoplatinates containing the auxiliary ligands 1,10′-phenanthroline (phen) or 2,2′-bipyridine (bpy) have been carried out by reaction of Ln³⁺ nitrate salts with phen or bpy and potassium tetracyanoplatinate in solvent systems containing dimethylsulfoxide and dimethylformamide. The use of these solvents has lead to the isolation of [{Ln(DMSO)₂(C₁₂H₈N₂)(H₂O)₃}₂Pt(CN)₄](Pt(CN)₄)₂·2C₁₂H₈N₂·4H₂O (Ln = Eu (Eu-1), Tb (Tb-1), Yb(Yb-1)), [Ln(DMF)₃(C₁₂H₈N₂)(H₂O)₂NO₃]Pt(CN)₄ (Ln = La (La-2), Eu (Eu-2), Tb (Tb-2)), and [Ln(DMF)₃(C₁₀H₈N₂)(H₂O)₂NO₃]Pt(CN)₄ (Ln = La (La-3), Sm (Sm-3), Eu (Eu-3), Tb (Tb-3)) in the form of single crystals. Single-crystal X-ray diffraction has been used to investigate their structural features. The use of DMSO versus DMF as the solvent results in markedly different structural features. Eu-1 contains [{Eu(DMSO)₂(C₁₂H₈N₂)(H₂O)₃}₂Pt(CN)₄]²⁺ complex cations where the two Eu³⁺ centers are linked by a trans-bridging Pt(CN)₄²⁻ anion to form a dimeric lanthanide complex cation. An additional uncoordinated Pt(CN)₄²⁻ anion balances charge. Eu-2 and Eu-3 consist of zero-dimensional salts with [Eu(DMF)₃(C₁₂H₈N₂)(H₂O)₂(NO₃)]²⁺ or [Eu(DMF)₃(C₁₀H₈N₂)(H₂O)₂(NO₃)]²⁺ complex cations, respectively, and only non-coordinated Pt(CN)₄²⁻ anions. Photoluminescence measurements illustrate that the Eu³⁺ and Tb³⁺ compounds for all three structure types display enhanced emission due to intramolecular energy transfer from the coordinated cyclic amines.     

Structural analysis and photoluminescence properties of low dimensional lanthanide tetracyanometallates

The synthesis of a number of lanthanide tetracyanometallate (TCM) compounds have been carried out by reaction of Ln³⁺ nitrate salts and potassium tetracyanometallates in solvent systems containing dimethylsulfoxide and water. These reactions result in the isolation of three distinct structure types: (1) monoclinic [Ln(DMSO)₄(H₂O)₃M(CN)₄](M(CN)₄)_0.5·2H₂O (Ln = Eu, Tb and M = Pd, Pt), (2) orthorhombic {La(DMSO)₃(H₂O)₂(NO₃)M(CN)₄}_∞·H₂O (M = Pd, Pt), and (3) orthorhombic {Ln(DMSO)₃(H₂O)(NO₃)M(CN)₄}_∞ (Ln = Tb and M = Pd, Pt; Ln = Er, Yb and M = Pt) in the form of single crystals. Single-crystal X-ray diffraction has been used to investigate their structural features. Structure type 1 is a zero dimensional ionic compound with a M/Ln ratio of 1.5:1. It contains coordinated as well as uncoordinated [M(CN)₄]²⁻ (M = Pd, Pt) anions and features relatively long platinophilic interactions. Structure types 2 and 3 differ quite drastically from structure type 1, but they are very similar to each other. Both of the latter are one-dimensional in nature due to chains containing linkage of Ln³⁺ coordination spheres with trans-bridging [M(CN)₄]²⁻ anions. These coordination polymers both have a M/Ln ratio of 1:1, a lack of platinophilic interactions, and incorporation of a bidentate NO₃⁻ for charge balance. Photoluminescence properties for select Eu³⁺ and Tb³⁺ compounds have been investigated. They show characteristic absorption and emission for the Ln³⁺ ions, but no significant influence of the tetracyanometallate anions.