Long-term viability and differentiation of bovine oviductal monolayers: bidimensional versus three-dimensional culture

Different in vitro models have been developed to study the interaction of gametes and embryos with the maternal tract. In cattle, the interaction of the oviduct with gametes and embryos have been classically studied using oviductal explants or monolayers (OMs). Explants are well differentiated but have to be used within 24 h after collection, whereas OMs can be used for a longer time after cell confluence but dedifferentiate during culture, losing cell polarity and ciliation. Herein, OMs were cultured either in M199 plus 10% fetal calf serum or in a semidefined culture medium (Gray's medium), in an immersed condition on collagen-coated coated microporous polyester or polycarbonate inserts under air-liquid interface conditions. The influence of culture conditions on long-term viability and differentiation of OMs was evaluated through scanning electron microscopy, localization of centrin and tubulin at the confocal laser scanning microscope, and assessment of maintenance of viability of sperm bound to OMs. Findings demonstrated that OMs cultured in an immersed condition with Gray's medium retain a better morphology, do not exhibit signs of crisis at least until 3 wks postconfluence, and maintain the viability of bound sperm significantly better than parallel OMs cultured in M199 plus 10% fetal calf serum. OM culture with Gray's medium in air-liquid interface conditions on porous inserts promotes cell polarity, ciliation, and maintenance of bound sperm viability at least until 3 wks postconfluence. In conclusion, oviduct culture in Gray's medium in an immersed or air-liquid condition allows long-term culture and, in the latter case, also ciliation of bovine OMs, and may represent in vitro systems that mimick more closely the biological processes modulated by the oviduct in vivo.

A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves)

The birds in the family Parulidae-commonly termed the New World warblers or wood-warblers-are a classic model radiation for studies of ecological and behavioral differentiation. Although the monophyly of a 'core' wood-warbler clade is well established, no phylogenetic hypothesis for this group has included a full sampling of wood-warbler species diversity. We used parsimony, maximum likelihood, and Bayesian methods to reconstruct relationships among all genera and nearly all wood-warbler species, based on a matrix of mitochondrial DNA (5840 nucleotides) and nuclear DNA (6 loci, 4602 nucleotides) characters. The resulting phylogenetic hypotheses provide a highly congruent picture of wood-warbler relationships, and indicate that the traditional generic classification of these birds recognizes many non-monophyletic groups. We recommend a revised taxonomy in which each of 14 genera (Seiurus, Helmitheros, Mniotilta, Limnothlypis, Protonotaria, Parkesia, Vermivora, Oreothlypis, Geothlypis, Setophaga, Myioborus, Cardellina, Basileuterus, Myiothlypis) corresponds to a well-supported clade; these nomenclatural changes also involve subsuming a number of well-known, traditional wood-warbler genera (Catharopeza, Dendroica, Ergaticus, Euthlypis, Leucopeza, Oporornis, Parula, Phaeothlypis, Wilsonia). We provide a summary phylogenetic hypothesis that will be broadly applicable to investigations of the historical biogeography, processes of diversification, and evolution of trait variation in this well studied avian group.

Delimiting species without nuclear monophyly in Madagascar's mouse lemurs

Background

Speciation begins when populations become genetically separated through a substantial reduction in gene flow, and it is at this point that a genetically cohesive set of populations attain the sole property of species: the independent evolution of a population-level lineage. The comprehensive delimitation of species within biodiversity hotspots, regardless of their level of divergence, is important for understanding the factors that drive the diversification of biota and for identifying them as targets for conservation. However, delimiting recently diverged species is challenging due to insufficient time for the differential evolution of characters—including morphological differences, reproductive isolation, and gene tree monophyly—that are typically used as evidence for separately evolving lineages.

Methodology

In this study, we assembled multiple lines of evidence from the analysis of mtDNA and nDNA sequence data for the delimitation of a high diversity of cryptically diverged population-level mouse lemur lineages across the island of Madagascar. Our study uses a multi-faceted approach that applies phylogenetic, population genetic, and genealogical analysis for recognizing lineage diversity and presents the most thoroughly sampled species delimitation of mouse lemur ever performed.

Conclusions

The resolution of a large number of geographically defined clades in the mtDNA gene tree provides strong initial evidence for recognizing a high diversity of population-level lineages in mouse lemurs. We find additional support for lineage recognition in the striking concordance between mtDNA clades and patterns of nuclear population structure. Lineages identified using these two sources of evidence also exhibit patterns of population divergence according to genealogical exclusivity estimates. Mouse lemur lineage diversity is reflected in both a geographically fine-scaled pattern of population divergence within established and geographically widespread taxa, as well as newly resolved patterns of micro-endemism revealed through expanded field sampling into previously poorly and well-sampled regions.

Human urotensin II induces tissue factor and cellular adhesion molecules expression in human coronary endothelial cells: an emerging role for urotensin II in cardiovascular disease

BACKGROUND

Human urotensin II is an 11-aminoacid peptide with a controversial role in the human cardiovascular system. Indeed, urotensin effects on vascular reactivity and in heart failure are well documented, while its potential role in the pathophysiology of athero-thrombosis is still unknown. This study investigates the effects of urotensin on tissue factor (TF) and VCAM-1/ICAM-1 expression in human coronary endothelial cells (HCAECs).

METHODS AND RESULTS

Urotensin induced TF-mRNA transcription as demonstrated by real time PCR and expression of TF that was functionally active as demonstrated by procoagulant activity assay. In addition, urotensin induced expression of VCAM-1 and ICAM-1 as demonstrated by FACS analysis. VCAM-1 and ICAM-1 were functionally active because they increased leukocyte adhesivity to HCAECs. Urotensin-induced expression of TF and of VCAM-1/ICAM-1 was mediated through the Rho A-activation of the transcription factor, NF-kappaB, as demonstrated by EMSA. Indeed, lovastatin, an HMG-CoA reductase inhibitor, by modulating the Rho activation, and NF-kappaB inhibitors, suppressed the urotensin effects on TF and CAMs.

CONCLUSIONS

Data of the present study, although in vitro, describe the close relationship existing between urotensin II and athero-thrombosis, providing for the first time support for the view that this peptide might have not only vasoactive functions but it might be an effector molecule able to induce a pro-atherothrombotic phenotype in cells of the coronary circulation. Although future studies are required to clarify whether these mechanisms are also important in the clinical setting, this report supports an emerging new role for urotensin II in the pathogenesis and progression of cardiovascular disease.

Development and application of a phylogenomic toolkit: resolving the evolutionary history of Madagascar's lemurs

Lemurs and the other strepsirrhine primates are of great interest to the primate genomics community due to their phylogenetic placement as the sister lineage to all other primates. Previous attempts to resolve the phylogeny of lemurs employed limited mitochondrial or small nuclear data sets, with many relationships poorly supported or entirely unresolved. We used genomic resources to develop 11 novel markers from nine chromosomes, representing approximately 9 kb of nuclear sequence data. In combination with previously published nuclear and mitochondrial loci, this yields a data set of more than 16 kb and adds approximately 275 kb of DNA sequence to current databases. Our phylogenetic analyses confirm hypotheses of lemuriform monophyly and provide robust resolution of the phylogenetic relationships among the five lemuriform families. We verify that the genus Daubentonia is the sister lineage to all other lemurs. The Cheirogaleidae and Lepilemuridae are sister taxa and together form the sister lineage to the Indriidae; this clade is the sister lineage to the Lemuridae. Divergence time estimates indicate that lemurs are an ancient group, with their initial diversification occurring around the Cretaceous-Tertiary boundary. Given the power of this data set to resolve branches in a notoriously problematic area of primate phylogeny, we anticipate that our phylogenomic toolkit will be of value to other studies of primate phylogeny and diversification. Moreover, the methods applied will be broadly applicable to other taxonomic groups where phylogenetic relationships have been notoriously difficult to resolve.

HMG-CoA Reductase Inhibitors Reduce Nicotine-Induced Expression of Cellular Adhesion Molecules in Cultured Human Coronary Endothelial Cells

BACKGROUND

Smoking predisposes to the development of atherosclerosis and of its complications. The mechanisms responsible for these effects are not completely understood. We have investigated whether nicotine might promote a proatherosclerotic state in human coronary endothelial cells (HCAECs), studying the role of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in preventing these phenomena.

METHODS AND RESULTS

Real-time PCR showed that nicotine induced a dose-dependent increase in mRNA levels for vascular cellular adhesion molecule-1 (VCAM-1)/intercellular adhesion molecule-1 (ICAM-1). Fluorescent-activated cell sorting analysis showed that nicotine induced expression of functionally active VCAM-1/ICAM-1, since they increased leukocyte adherence to HCAECs. Oxygen free radicals, Rho A and nuclear factor kappaB (NF-kappaB) play a pivotal role in modulating these effects. Indeed, nicotine caused oxygen free radical production as well as activation of Rho A and NF-kappaB pathways, evaluated by malondialdehyde levels, pulldown assay and by electrophoretic mobility shift assay, respectively. Superoxide dimutase, Rho A (Y-27639) and NF-kappaB inhibitors (pyrrolidine dithiocarbamate ammonium, Bay 11-7082) suppressed nicotine effects on CAM expression. HMG-CoA reductase inhibitors prevented these nicotine-mediated effects by inhibiting free radical generation and by modulating activation of Rho A and NF-kappaB pathways.

CONCLUSIONS

Nicotine promotes CAM expression on HCAECs, shifting them toward a proatherosclerotic state. These effects might explain, at least in part, the deleterious cardiovascular consequences of cigarette smoking. HMG-CoA reductase inhibitors play an important role in preventing these phenomena.

Expression and functions of the vascular endothelial growth factors and their receptors in human basophils

Angiogenesis is a multistep complex phenomenon critical for several inflammatory and neoplastic disorders. Basophils, normally confined to peripheral blood, can infiltrate the sites of chronic inflammation. In an attempt to obtain insights into the mechanism(s) underlying human basophil chemotaxis and its role in inflammation, we have characterized the expression and function of vascular endothelial growth factors (VEGFs) and their receptors in these cells. Basophils express mRNA for three isoforms of VEGF-A (121, 165, and 189) and two isoforms of VEGF-B (167 and 186). Peripheral blood and basophils in nasal polyps contain VEGF-A localized in secretory granules. The concentration of VEGF-A in basophils was 144.4 +/- 10.8 pg/10(6) cells. Immunologic activation of basophils induced the release of VEGF-A. VEGF-A (10-500 ng/ml) induced basophil chemotaxis. Supernatants of activated basophils induced an angiogenic response in the chick embryo chorioallantoic membrane that was inhibited by an anti-VEGF-A Ab. The tyrosine kinase VEGFR-2 (VEGFR-2/KDR) mRNA was expressed in basophils. These cells also expressed mRNA for the soluble form of VEGFR-1 and neuropilin (NRP)1 and NRP2. Flow cytometric analysis indicated that basophils express epitopes recognized by mAbs against the extracellular domains of VEGFR-2, NRP1, and NRP2. Our data suggest that basophils could play a role in angiogenesis and inflammation through the expression of several forms of VEGF and their receptors.

Neopterin induces pro-atherothrombotic phenotype in human coronary endothelial cells

BACKGROUND

Inflammation plays a pivotal role in atherothrombosis. Recent data indicate that serum levels of neopterin, a marker of inflammation and immune modulator secreted by monocytes/macrophages, are elevated in patients with acute coronary syndromes and seem to be a prognostic marker for major cardiovascular events. The aim of the present study was to determine whether neopterin might affect the thrombotic and atherosclerotic characteristics of human coronary artery endothelial cells (HCAECs).

METHODS AND RESULTS

In HCAECs, neopterin induced TF-mRNA transcription as demonstrated by real time polymerase chain reaction and expression of functionally active tissue factor (TF) as demonstrated by procoagulant activity assay, and of cellular adhesion molecules (CAMs) as demonstrated by FACS analysis, in a dose-dependent fashion. These neopterin effects were prevented by lovastatin, a HMG-CoA reductase inhibitor. Neopterin-induced TF and CAMs expression was mediated by oxygen free radicals through the activation of the transcription factor, nuclear factor-kappa B (NF-kappaB), as demonstrated by electrophoretic mobility shift assay and by suppression of CAMs and TF expression by superoxide dismutase and by NF-kappaB inhibitor, pyrrolidine-dithio-carbamate ammonium.

CONCLUSIONS

These data indicate that neopterin exerts direct effects on HCAECs by promoting CAMs and TF expression and support the hypothesis that neopterin, besides representing a marker of inflammation, might be an effector molecule able to induce a pro-atherothrombotic phenotype in cells of the coronary circulation.

Urokinase induces basophil chemotaxis through a urokinase receptor epitope that is an endogenous ligand for formyl peptide receptor-like 1 and -like 2

Basophils circulate in the blood and are able to migrate into tissues at sites of inflammation. Urokinase plasminogen activator (uPA) binds a specific high affinity surface receptor (uPAR). The uPA-uPAR system is crucial for cell adhesion and migration, and tissue repair. We have investigated the presence and function of the uPA-uPAR system in human basophils. The expression of uPAR was found at both mRNA and protein levels. The receptor was expressed on the cell surface of basophils, in the intact and cleaved forms. Basophils did not express uPA at either the protein or mRNA level. uPA (10(-12)-10(-9) M) and its uPAR-binding N-terminal fragment (ATF) were potent chemoattractants for basophils, but did not induce histamine or cytokine release. Inactivation of uPA enzymatic activity by di-isopropyl fluorophosphate did not affect its chemotactic activity. A polyclonal Ab against uPAR inhibited uPA-dependent basophil chemotaxis. The uPAR-derived peptide 84-95 (uPAR84-95) induced basophil chemotaxis. Basophils expressed mRNA for the formyl peptide receptors formyl peptide receptor (FPR), FPR-like 1 (FPRL1), and FPRL2. The FPR antagonist cyclosporin H prevented chemotaxis induced by FMLP, but not that induced by uPA and uPAR84-95. Incubation of basophils with low and high concentrations of FMLP, which desensitize FPR and FPRL1, respectively, but not FPRL2, slightly reduced the chemotactic response to uPA and uPAR84-95. In contrast, desensitization with WKYMVm, which also binds FPRL2, markedly inhibited the response to both molecules. Thus, uPA is a potent chemoattractant for basophils that seems to act through exposure of the chemotactic uPAR epitope uPAR84-95, which is an endogenous ligand for FPRL2 and FPRL1.

Basophils Infiltrate Human Gastric Mucosa at Sites of Helicobacter pylori Infection, and Exhibit Chemotaxis in Response to H. pylori-derived Peptide Hp(2–20)

Basophils, which are normally confined to the circulation, can migrate to sites of allergic inflammation. Using the specific mAb, BB1, we detected basophil infiltration of the gastric mucosa of Helicobacter pylori-infected patients affected by moderate and severe gastritis. Basophils were not found in H. pylori-free individuals or in subjects with mild gastritis. The H. pylori-derived peptide, Hp(2-20), was a potent basophil chemoattractant in vitro, whereas the control peptide, Hp1, was ineffective. Basophils from peripheral blood of healthy volunteers expressed mRNA for the formyl peptide receptors, N-formyl-peptide receptor (FPR), FPR-like (FPRL)1, and FPRL2. Preincubation of basophils with FMLP or Hp(2-20) caused complete desensitization to a subsequent challenge with homologous stimulus. Incubation of basophils with a low concentration of FMLP, which binds with high affinity to FPR, but not to FPRL1 or FPRL2, did not affect the chemotactic response to Hp(2-20). In contrast, a high concentration of FMLP, which binds to FPRL1 and FPRL2, reduced the chemotactic response to Hp(2-20). The FPR antagonist, cyclosporin H, prevented chemotaxis induced by FMLP, but not by Hp(2-20). Hp(2-20) could be responsible, at least in part, for basophil infiltration of the gastric mucosa of H. pylori-infected patients presumably through the interaction with FPRL1 and FPRL2.

HIV-1 envelope gp41 peptides promote migration of human Fc epsilon RI+ cells and inhibit IL-13 synthesis through interaction with formyl peptide receptors

We evaluated the effects of synthetic peptides (2017, 2019, 2020, 2021, 2023, 2027, 2029, 2030, 2031, and 2035) encompassing the structure of HIV-1(MN) envelope gp41 on both chemotaxis of human basophils and the release of preformed mediators (histamine) and of cytokines (IL-13). Peptides 2019 and 2021 were potent basophil chemoattractants, whereas the other peptides examined were ineffective. Preincubation of basophils with FMLP or gp41 2019 resulted in complete desensitization to a subsequent challenge with homologous stimulus. Incubation of basophils with low concentration (5 x 10(-7) M) of FMLP, which binds with high affinity to N-formyl peptide receptor (FPR), but not to FPR-like 1, did not affect the chemotactic response to a heterologous stimulus (gp41 2019). In contrast, a high concentration (10(-4) M) of FMLP, which binds also to FPR-like 1, significantly reduced the chemotactic response to gp41 2019. The FPR antagonist cyclosporin H inhibited chemotaxis induced by FMLP, but not by gp41 2019. None of these peptides singly induced the release of histamine or cytokines (IL-4 and IL-13) from basophils. However, low concentrations of peptides 2019 and 2021 (10(-8)-10(-6) M) inhibited histamine release from basophils challenged with FMLP but not the secretion caused by anti-IgE and gp120. Preincubation of basophils with peptides 2019 and 2021 inhibited the expression of both IL-13 mRNA, and the FMLP-induced release of IL-13 from basophils. These data highlight the complexity of the interactions between viral and bacterial peptides with FPR subtypes on human basophils.