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201.
202.
Hanna Mannell Ariane Hammitzsch Ramona Mettler Ulrich Pohl Florian Krtz 《Cellular signalling》2010,22(1):88-96
Angiogenesis initiation is crucially dependent on endothelial proliferation and can be stimulated by the fibroblast growth factor 2 (FGF-2). The DNA dependent protein kinase (DNA-PK), long known for its importance in repairing DNA double strand breaks, belongs to the phosphatidylinositol-3 kinase (PI3-K) super family and has recently been identified as one of the enzymes phosphorylating and activating Akt. Due to its similarity with PI3-K, we hypothesized that DNA-PK may have similar effects on endothelial angiogenic processes and signalling. We used primary endothelial cells (HUVEC and PAEC) and human microvascular endothelial cells (HMEC) to study the role of DNA-PK in endothelial proliferation and signalling. DNA-PKcs suppression with the compound NU7026 or with siRNA induced basal endothelial cell proliferation as well as enhanced FGF-2 dependent proliferation. This was associated with an increase in phosphorylated Akt. Tube formation was not affected by DNA-PKcs clearly showing that the role of DNA-PK in endothelial processes differs from that of PI3-K. Our findings indicate DNA-PK as an important enzyme maintaining the quiescent endothelial phenotype by actively inhibiting Akt thus restraining endothelial cell proliferation preventing excessive growth. 相似文献
203.
204.
Kremer MC Christiansen F Leiss F Paehler M Knapek S Andlauer TF Förstner F Kloppenburg P Sigrist SJ Tavosanis G 《Current biology : CB》2010,20(21):1938-1944
How does the sensory environment shape circuit organization in higher brain centers? Here we have addressed the dependence on activity of a defined circuit within the mushroom body of adult Drosophila. This is a brain region receiving olfactory information and involved in long-term associative memory formation. The main mushroom body input region, named the calyx, undergoes volumetric changes correlated with alterations of experience. However, the underlying modifications at the cellular level remained unclear. Within the calyx, the clawed dendritic endings of mushroom body Kenyon cells form microglomeruli, distinct synaptic complexes with the presynaptic boutons of olfactory projection neurons. We developed tools for high-resolution imaging of pre- and postsynaptic compartments of defined calycal microglomeruli. Here we show that preventing firing of action potentials or synaptic transmission in a small, identified fraction of projection neurons causes alterations in the size, number, and active zone density of the microglomeruli formed by these neurons. These data provide clear evidence for activity-dependent organization of a circuit within the adult brain of the fly. 相似文献
205.
Schiestl FP 《Current biology : CB》2010,20(23):R1020-R1022
Why do plants mimic female insects to attract males for pollination? A new study gives insights into the advantages of sexual mimicry and documents this pollination system for the first time outside the orchid family, in a South African daisy. 相似文献
206.
Florian Maderspacher 《Current biology : CB》2010,20(12):R513-R515
207.
Coassin S Schweiger M Kloss-Brandstätter A Lamina C Haun M Erhart G Paulweber B Rahman Y Olpin S Wolinski H Cornaciu I Zechner R Zimmermann R Kronenberg F 《PLoS genetics》2010,6(12):e1001239
Recent studies demonstrated a strong influence of rare genetic variants on several lipid-related traits. However, their impact on free fatty acid (FFA) plasma concentrations, as well as the role of rare variants in a general population, has not yet been thoroughly addressed. The adipose triglyceride lipase (ATGL) is encoded by the PNPLA2 gene and catalyzes the rate-limiting step of lipolysis. It represents a prominent candidate gene affecting FFA concentrations. We therefore screened the full genomic region of ATGL for mutations in 1,473 randomly selected individuals from the SAPHIR (Salzburg Atherosclerosis Prevention program in subjects at High Individual Risk) Study using a combined Ecotilling and sequencing approach and functionally investigated all detected protein variants by in-vitro studies. We observed 55 novel mostly rare genetic variants in this general population sample. Biochemical evaluation of all non-synonymous variants demonstrated the presence of several mutated but mostly still functional ATGL alleles with largely varying residual lipolytic activity. About one-quarter (3 out of 13) of the investigated variants presented a marked decrease or total loss of catalytic function. Genetic association studies using both continuous and dichotomous approaches showed a shift towards lower plasma FFA concentrations for rare variant carriers and an accumulation of variants in the lower 10%-quantile of the FFA distribution. However, the generally rather small effects suggest either only a secondary role of rare ATGL variants on the FFA levels in the SAPHIR population or a recessive action of ATGL variants. In contrast to these rather small effects, we describe here also the first patient with "neutral lipid storage disease with myopathy" (NLSDM) with a point mutation in the catalytic dyad, but otherwise intact protein. 相似文献
208.
Martin Hucík Marek Bučko Peter Gemeiner Vladimír Štefuca Alica Vikartovská Marko D. Mihovilovič Florian Rudroff Naseem Iqbal Dušan ChorvátJr. Igor Lacík 《Biotechnology letters》2010,32(5):675-680
Recombinant Escherichia coli cells, over-expressing cyclopentanone monooxygenase activity, were immobilized in polyelectrolyte complex capsules, made
of sodium alginate, cellulose sulfate, poly(methylene-co-guanidine), CaCl2 and NaCl. More than 90% of the cell viability was preserved during the encapsulation process. Moreover, the initial enzyme
activity was fully maintained within encapsulated cells while it halved in free cells. Both encapsulated and free cells reached
the end point of the Baeyer–Villiger biooxidation of 8-oxabicyclo[3.2.1]oct-6-en-3-one to 4,9-dioxabicyclo[4.2.1]non-7-en-3-one
at the same time (48 h). Similarly, the enantiomeric excess above 94% was identical for encapsulated and free cells. 相似文献
209.
Silke Appenzeller Anja Schirmacher Hartmut Halfter Manuela Pendziwiat Peter De Jonghe Florian Stögbauer Margret Hund E. Bernd Ringelstein 《American journal of human genetics》2010,86(1):83-87
Autosomal-dominant striatal degeneration (ADSD) is an autosomal-dominant movement disorder affecting the striatal part of the basal ganglia. ADSD is characterized by bradykinesia, dysarthria, and muscle rigidity. These symptoms resemble idiopathic Parkinson disease, but tremor is not present. Using genetic linkage analysis, we have mapped the causative genetic defect to a 3.25 megabase candidate region on chromosome 5q13.3-q14.1. A maximum LOD score of 4.1 (Θ = 0) was obtained at marker D5S1962. Here we show that ADSD is caused by a complex frameshift mutation (c.94G>C+c.95delT) in the phosphodiesterase 8B (PDE8B) gene, which results in a loss of enzymatic phosphodiesterase activity. We found that PDE8B is highly expressed in the brain, especially in the putamen, which is affected by ADSD. PDE8B degrades cyclic AMP, a second messenger implied in dopamine signaling. Dopamine is one of the main neurotransmitters involved in movement control and is deficient in Parkinson disease. We believe that the functional analysis of PDE8B will help to further elucidate the pathomechanism of ADSD as well as contribute to a better understanding of movement disorders. 相似文献
210.
Dietrich Trümbach Cornelia Graf Benno Pütz Claudia Kühne Marcus Panhuysen Peter Weber Florian Holsboer Wolfgang Wurst Gerhard Welzl Jan M Deussing 《BMC systems biology》2010,4(1):159