1,720,986 research outputs found
Vascular endothelial growth factor up-regulation in the mouse hippocampus and its role in the control of epileptiform activity
No full textThe vascular endothelial growth factor (VEGF) signalling pathway may represent an endogenous anti-convulsant in the rodent hippocampus although its exact contribution requires some clarification. In mouse hippocampal slices, the potassium channel blocker 4-aminopyridine (4-AP) in the absence of external Mg(2+)(0 Mg(2+)) produces both ictal and interictal activity followed by a prolonged period of repetitive interictal activity. In this model, we demonstrated that exogenous VEGF has clear effects on ictal and interictal activity as it reduces the duration of ictal-like events, but decreases the frequency and intensity of interictal discharges. VEGF affects epileptiform activity through its receptor VEGFR-2. We also demonstrated for the first time that the synaptic action of VEGF in the hippocampus is through VEGFR-2-mediated effects on NMDA and GABA(B) receptors and that VEGF does not affect the NMDA excytatory postsynaptic potential paired-pulse facilitation ratio. Exogenous VEGF does not affect the AMPA-mediated responses and the dendritic or the somatic GABA(A) inhibitory postsynaptic potentials. In addition, VEGF drastically reduces 0 Mg(2+)/4-AP-induced glutamate release through VEGFR-2 activation. In vitro epileptiform activity is sufficient to increase hippocampal expression of VEGF and VEGFR-2, and this up-regulation may serve a neuroprotective and/or anti-convulsant role. VEGFR-2 up-regulation has been localized to the CA1 region, which suggests that VEGF signalling may protect CA1 pyramidal cells from hyperexcitability. These results indicate that VEGF controls epileptic activity by influencing both glutamatergic and GABAergic transmission and further advance our understanding of the conditions required for endogenous VEGF up-regulation, and the mechanisms by which VEGF achieves an anti-convulsant effect
Proteomic, pigment composition and organization of thylakoid membranes in iron-deficient spinach leaves
No full textAnalysis of mitochondrial proteome of cybrid cell harbouring a disruptive mitochondrial DNA mutation in respiratory complex I.
No full textCybrid Cell Lines As a Model to Study the Effects of Mitochondrial DNA Mutations on the Mitochondrial Proteome.
No full textA distruptive mitochondrial DNA mutation in respiratory complex I: Two-dimensional electrophoresis analysis of mitochondrial proteome of cybrid cell lines.
No full textMultidimensional proteomic analysis of photosynthetic membrane proteins by liquid extraction-ultracentrifugation-liquid chromatography-mass spectrometry
No full textProteome and metabolome profiling of wild-type and YCA1-knock-out yeast cells during acetic acid-induced programmed cell death
Full text linkCaspase proteases are responsible for the regulated disassembly of the cell into apoptotic bodies during mammalian apoptosis. Structural homologues of the caspase family (called metacaspases) are involved in programmed cell death in single-cell eukaryotes, yet the molecular mechanisms that contribute to death are currently undefined. Recent evidence revealed that a programmed cell death process is induced by acetic acid (AA-PCD) in Saccharomyces cerevisiae both in the presence and absence of metacaspase encoding gene YCA1. Here, we report an unexpected role for the yeast metacaspase in protein quality and metabolite control. By using an "omics" approach, we focused our attention on proteins and metabolites differentially modulated en route to AA-PCD either in wild type or YCA1-lacking cells. Quantitative proteomic and metabolomic analyses of wild type and Δyca1 cells identified significant alterations in carbohydrate catabolism, lipid metabolism, proteolysis and stress-response, highlighting the main roles of metacaspase in AA-PCD. Finally, deletion of YCA1 led to AA-PCD pathway through the activation of ceramides, whereas in the presence of the gene yeast cells underwent an AA-PCD pathway characterized by the shift of the main glycolytic pathway to the pentose phosphate pathway and a proteolytic mechanism to cope with oxidative stress
Induction of apoptosis in Jeko-1 mantle cell lymphoma cell line by resveratrol: a proteomic analysis.
No full textTherapies for mantle cell lymphoma (MCL) are clinically unsatisfactory, and the search for effective
drugs in vitro might foster the evaluation of their activity in vivo. We have investigated the effects of
the polyphenolic compound resveratrol on the MCL cell line Jeko-1 using a combination of flow
cytometry, Western blotting and two-dimensional electrophoresis to identify the molecules involved
in the induction of apoptosis and cell growth regulation. We show that resveratrol induces apoptosis
in Jeko-1 cells and modulates several key molecules, including cyclin D1 (CCND1), p53 (TP53), p21
(CDKN1A), BCL2, BAX, BclXL (BCL2L1), caspase 9 (CASP9) and p27 (CDKN1B). By high-resolution 2DPAGE
and nano-reverse phase-high performance liquid chromatography coupled with tandem mass
spectrometry, we identified 32 differentially expressed proteins in response to resveratrol treatment
that belong to important cell death related networks (including c-myc, NF-κB and the mitochondrial
apoptotic pathway). These findings may improve the understanding of mechanisms mediating the proapoptotic
effects of resveratrol on MCL cells, and form the basis for its potential use as a therapeutic
agent
Differential proteome-metabolome profiling of YCA1-knock-out and wild type cells reveals novel metabolic pathways and cellular processes dependent on the yeast metacaspase
No full textThe yeast Saccharomyces cerevisiae expresses one member of the metacaspase Cys protease family, encoded by the YCA1 gene. Combination of proteomics and metabolomics data showed that YCA1 deletion down-regulated glycolysis, the TCA cycle and alcoholic fermentation as compared with WT cells. Δyca1 cells also showed a down-regulation of the pentose phosphate pathway and accumulation of pyruvate, correlated with higher levels of certain amino acids found in these cells. Accordingly, there is a decrease in protein biosynthesis, and up-regulation of specific stress response proteins like Ahp1p, which possibly provides these cells with a better protection against stress. Moreover, in agreement with the down-regulation of protein biosynthesis machinery in Δyca1 cells, we have found that regulation of transcription, co-translational protein folding and protein targeting to different subcellular locations were also down-regulated. Metabolomics analysis of the nucleotide content showed a significant reduction in Δyca1 cells in comparison with the WT, except for GTP content which remained unchanged. Thus, our combined proteome-metabolome approach added a new dimension to the non-apoptotic function of yeast metacaspase, which can specifically affect cell metabolism through as yet unknown mechanisms and possibly stress-response pathways, like HOG and cell wall integrity pathways. Certainly, YCA1 deletion may induce compensatory changes in stress response proteins offering a better protection against apoptosis to Δyca1 cells rather than a loss in pro-apoptotic YCA1-associated activity
Analysis of Mitochondrial Proteome of Cybrid Cells Harbouring a Truncative Mitochondrial DNA Mutation in Respiratory Complex I. Molecular BioSystems.
No full textTransmitochondrial cytoplasmic hybrids (cybrids) are well established model systems to reveal the effects of
mitochondrial DNA (mtDNA) mutations on cell metabolism excluding the interferences of a different nuclear
background. The m.3571insC mutation in the MTND1 gene of respiratory complex I (CI) is commonly
detected in oncocytic tumors, in which it causes a severe CI dysfunction leading to an energetic impairment
when present above 83% mutant load. To assess whether the energetic deficit may alter the mitochondrial
proteome, OS-78 and OS-93 cybrid cell lines bearing two different degrees of the m.3571insC mutation
(78% and 92.8%, respectively) and control cybrids bearing wild-type mtDNA (CC) were analyzed. Twodimensional
electrophoresis and mass spectrometry revealed significant alterations only in cybrids above
the threshold (OS-93). All differentially expressed proteins are decreased. In particular, the levels of the
pyruvate dehydrogenase E1 chain B subunit (E1b), of lipoamide dehydrogenase (E3), the enzyme
component of pyruvate and 2-oxoglutarate dehydrogenase complexes, and of lactate dehydrogenase B
(LDHB) were reduced. Moreover, a significant decrease of the pyruvate dehydrogenase complex activity
was found when OS-93 cybrid cells were grown in galactose medium, a metabolic condition that forces
cells to use respiration. These results demonstrate that the energetic impairment caused by the almost
homoplasmic m.3571insC mutation perturbs cellular metabolism leading to a decreased steady state
level of components of very important mitochondrial NAD-dependent dehydrogenases
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