Cellular target genes of Epstein-Barr virus nuclear antigen 2

Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA-2) is a key determinant in the EBV-driven B-cell growth transformation process. By activating an array of viral and cellular target genes, EBNA-2 initiates a cascade of events which ultimately cause cell cycle entry and the proliferation of the infected B cell. In order to identify cellular target genes that respond to EBNA-2 in the absence of other viral factors, we have performed a comprehensive search for EBNA-2 target genes in two EBV-negative B-cell lines. This screen identified 311 EBNA-2-induced and 239 EBNA-2-repressed genes that were significantly regulated in either one or both cell lines. The activation of most of these genes had not previously been attributed to EBNA-2 function and will be relevant for the identification of EBNA-2-specific contributions to EBV-associated malignancies. The diverse spectrum of EBNA-2 target genes described in this study reflects the broad spectrum of EBNA-2 functions involved in virus-host interactions, including cell signaling molecules, adapters, genes involved in cell cycle regulation, and chemokines.     

Leadership in Moving Human Groups

How is movement of individuals coordinated as a group? This is a fundamental question of social behaviour, encompassing phenomena such as bird flocking, fish schooling, and the innumerable activities in human groups that require people to synchronise their actions. We have developed an experimental paradigm, the HoneyComb computer-based multi-client game, to empirically investigate human movement coordination and leadership. Using economic games as a model, we set monetary incentives to motivate players on a virtual playfield to reach goals via players'' movements. We asked whether (I) humans coordinate their movements when information is limited to an individual group member''s observation of adjacent group member motion, (II) whether an informed group minority can lead an uninformed group majority to the minority''s goal, and if so, (III) how this minority exerts its influence. We showed that in a human group – on the basis of movement alone – a minority can successfully lead a majority. Minorities lead successfully when (a) their members choose similar initial steps towards their goal field and (b) they are among the first in the whole group to make a move. Using our approach, we empirically demonstrate that the rules of swarming behaviour apply to humans. Even complex human behaviour, such as leadership and directed group movement, follow simple rules that are based on visual perception of local movement.     

N-(3-Cyano-4,5,6,7-tetrahydro-1-benzothien-2-yl)amides as potent, selective, inhibitors of JNK2 and JNK3

The identification and exploration of a novel, potent and selective series of N-(3-cyano-4,5,6,7-tetrahydro-1-benzothien-2-yl)amide inhibitors of JNK2 and JNK3 kinases is described. Compounds 5a and 11a were identified as potent inhibitors of JNK3 (pIC50 6.7 and 6.6, respectively), with essentially equal potency against JNK2 (pIC50 6.5). Selectivity within the mitogen-activated protein kinase (MAPK) family, against JNK1, p38alpha and ERK2, was observed for the series. X-ray crystallography of 5e and 8a in JNK3 revealed a unique binding mode, with the 3-cyano substituent forming an H-bond acceptor interaction with the hinge region of the ATP-binding site.     

Systematic detection of polygenic cis-regulatory evolution

The idea that most morphological adaptations can be attributed to changes in the cis-regulation of gene expression levels has been gaining increasing acceptance, despite the fact that only a handful of such cases have so far been demonstrated. Moreover, because each of these cases involves only one gene, we lack any understanding of how natural selection may act on cis-regulation across entire pathways or networks. Here we apply a genome-wide test for selection on cis-regulation to two subspecies of the mouse Mus musculus. We find evidence for lineage-specific selection at over 100 genes involved in diverse processes such as growth, locomotion, and memory. These gene sets implicate candidate genes that are supported by both quantitative trait loci and a validated causality-testing framework, and they predict a number of phenotypic differences, which we confirm in all four cases tested. Our results suggest that gene expression adaptation is widespread and that these adaptations can be highly polygenic, involving cis-regulatory changes at numerous functionally related genes. These coordinated adaptations may contribute to divergence in a wide range of morphological, physiological, and behavioral phenotypes.     

Importance of monocytes/macrophages and fibroblasts for healing of micronecroses in porcine myocardium

In porcine heart, embolization of small coronary arteries with microspheres in 25 m in diameter induces collateral capillary vessel growth by angiogenesis in and around focal necrosis. By histological analysis the inflammatory infiltrates in this porcine tissue were characterized by numerous monocytes/macrophages and fibroblasts as well as neutrophils and numerous capillaries, some in mitosis. The aim of the present study, therefore, was to clarify the role of monocytes/macrophages and fibroblasts in angiogenesis and in repair in ischemic porcine myocardium. Using a human acidic fibroblast growth factor (aFGF) cDNA probe forin situ hybridisation labeling for aFGF mRNA was seen in monocytes and macrophages only, beginning at day 1, with a maximum at 3 and 7 days, and minimal labeling at 4 weeks. We have also shown, with a specific antibody and fluorescence microscopy, that tumur necrosis factor alpha (TNF) follows the same time sequence and that it is produced by monocytes/macrophages. The number of capillaries in infiltrates at 3 and 7 days as revealed by the lectin Dolichus Biflorus Agglutinin was high and declined at 4 weeks.In situ hybridisation using a rat cDNA probe for fibronectin showed the increased production of fibronectin mRNA in fibroblasts. To describe the expression of fibronectin and the collagens I, III, VI immunohistochemistry was used. A comparison showed that fibroblasts produced fibronectin mRNA starting at day 3, but the protein was only maximally expressed at day 7 and 4 weeks. Collagen I, III, VI expression was highest at 1–4 weeks. Conclusion: monocytes and macrophages produce the growth factors aFGF and TNF which seem to be important for angiogenesis in the ischemic myocardium. Fibroblasts, while they produce fibronectin and collagen, exert their major function in repair and scar formation, but may take also part in angiogenesis.     

Beiträge zur Zytologie der Bromeliaceae

Zusammenfassung Die gefundenen Chromosomenzahlen bestätigen im großen und ganzen das vonMez aufgestellte System.DiePitcairnioideae stellen eine einheitliche Gruppe mit der Grundzahl 5 (25) dar.Bei denBromelioideae lassen sich dagegen drei Gruppen unterscheiden: der VerwandtschaftskreisAechmea-Ananas mit der Grundzahl 5 (25) vermittelt den Anschluß an diePitcairnioideae die Mehrzahl derBromelioideae weist die Grundzahl 9 auf; die GattungBromelia mit der Grundzahl 4 leitet zu denTillandsioideae über.DieTillandsioideae scheinen nach den bisherigen, Befunden eine einheitliche Gruppe mit der Grundzahl 4 zu sein.In bezug auf die Entwicklung der männlichen und weiblichen Haploidgeneration stellen dieBromeliaceae eine einheitliche Familie dar. Die Zytokinese der Pollenmutterzellen erfolgt sukzedan, die reifen Pollenkörner sind zweikernig. Es werden normale achtkernige, Embryosäcke gebildet.Durch Kernmessungen wurde festgestellt, daß die Kerngröße nicht in dem Maße übereinstimmt, wieKlieneberger es angibt. Das Wachstum der Kerne erfolgt durch rhythmische Verdoppelung.Mit 20 Textabbildungen.     

Senescence and human chromosome changes

Summary A girl with slight psychomotor retardation, microphthalmia, and colobomata of the left eye, a hypotrophy of the right arm and a surnumerary digit on the right hand is described. The routine chromsome analysis and a G-banding analysis revealed an elongated long arm of chromosome 10. An extra light and dark band was present proximally. Both parents had normal chromosomes. While the visual comparison of the abnormal with the normal chromosome 10, did not enable the extra bands of the normal bands q21 and q22 to be distinguished. However, measurements of length, surface area, and relative reflection of the different light and dark bands of the long arm on tracings or directly on the normal and abnormal chromosomes, enabled us to precisely locate the extra bands and to determine that the abnormal chromosome was a result of an insertional translocation. The value of such measurements is discussed.     

Profilin-1 is expressed in human atherosclerotic plaques and induces atherogenic effects on vascular smooth muscle cells

Background

Profilin-1 is an ubiquitous actin binding protein. Under pathological conditions such as diabetes, profilin-1 levels are increased in the vascular endothelium. We recently demonstrated that profilin-1 overexpression triggers indicators of endothelial dysfunction downstream of LDL signaling, and that attenuated expression of profilin-1 confers protection from atherosclerosis in vivo.

Methodology

Here we monitored profilin-1 expression in human atherosclerotic plaques by immunofluorescent staining. The effects of recombinant profilin-1 on atherogenic signaling pathways and cellular responses such as DNA synthesis (BrdU-incorporation) and chemotaxis (modified Boyden-chamber) were evaluated in cultured rat aortic and human coronary vascular smooth muscle cells (VSMCs). Furthermore, the correlation between profilin-1 serum levels and the degree of atherosclerosis was assessed in humans.

Principal Findings

In coronary arteries from patients with coronary heart disease, we found markedly enhanced profilin expression in atherosclerotic plaques compared to the normal vessel wall. Stimulation of rat aortic and human coronary VSMCs with recombinant profilin-1 (10⁻⁶ M) in vitro led to activation of intracellular signaling cascades such as phosphorylation of Erk1/2, p70^S6 kinase and PI3K/Akt within 10 minutes. Furthermore, profilin-1 concentration-dependently induced DNA-synthesis and migration of both rat and human VSMCs, respectively. Inhibition of PI3K (Wortmannin, {type:entrez-nucleotide,attrs:{text:LY294002,term_id:1257998346,term_text:LY294002}}LY294002) or Src-family kinases (SU6656, PP2), but not PLCγ ({type:entrez-nucleotide,attrs:{text:U73122,term_id:4098075,term_text:U73122}}U73122), completely abolished profilin-induced cell cycle progression, whereas PI3K inhibition partially reduced the chemotactic response. Finally, we found that profilin-1 serum levels were significantly elevated in patients with severe atherosclerosis in humans (p<0.001 vs. no atherosclerosis or control group).

Conclusions

Profilin-1 expression is significantly enhanced in human atherosclerotic plaques compared to the normal vessel wall, and the serum levels of profilin-1 correlate with the degree of atherosclerosis in humans. The atherogenic effects exerted by profilin-1 on VSMCs suggest an auto-/paracrine role within the plaque. These data indicate that profilin-1 might critically contribute to atherogenesis and may represent a novel therapeutic target.