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Candidate Proteins (candidate + protein)
Selected AbstractsProteomic Analysis of Shear Stress-Mediated Protection from TNF-, in Endothelial CellsMICROCIRCULATION, Issue 4 2010Julie K. Freed Microcirculation (2010) 17, 259,270. doi: 10.1111/j.1549-8719.2010.00031.x Abstract Previous studies have shown that physiological levels of shear stress can protect endothelial cells (ECs) from apoptotic stimuli. Here, we differentiate between acute and chronic protection and demonstrate the use of proteomic technologies to uncover mechanisms associated with chronic protection of ECs. We hypothesized that changes in abundance of proteins associated with the TNF-, signaling cascade orchestrate shear stress-mediated protection from TNF-, when cells are preconditioned with shear prior to the exposure of apoptotic stimuli. Detection of cleaved caspase 3 through Western blot analysis confirmed chronic shear stress-mediated protection from TNF-,. In the presence of the nitric oxide synthase inhibitor, LNMA (N, -monomethyl- l -arginine), chronic protection remained. Treatment with a de novo protein synthesis inhibitor, cycloheximide, eliminated this protective effect. Isotopic-labeling experiments, coupled with LC,MS/MS (liquid chromatography,tandem mass spectrometry) of isolated components of the TNF-, pathway revealed that CARD9, a known activator of the NF-,B pathway, was increased (60%) in sheared cells versus nonsheared cells. This result was confirmed through Western blot analysis. Our data suggest that de novo formation of proteins is required for protection from TNF-, in ECs chronically exposed to shear stress, and that CARD9 is a candidate protein in this response. [source] Identification of metastasis candidate proteins among HCC cell lines by comparative proteome and biological function analysis of S100A4 in metastasis in vitroPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 22 2006Jie Feng Cui Abstract Widespread metastasis of hepatocellular carcinoma,(HCC) was a complex cascade of events, which is still beyond full appreciation. Screening key proteins, which play a critical role in metastasis, using high-throughput proteomics approach help discover valuable biomarkers and elucidate the mechanism of metastasis. This study was to find out some metastasis candidate proteins among HCC cell lines with various metastatic potential by comparative proteomics, and then further validate the biological function of these proteins in metastasis in,vitro. The protein profiles of metastatic HCC cell lines (MHCC97H and MHCC97L) displayed obvious differences compared with nonmetastatic ones (Hep3B). Twenty-six metastasis candidate proteins, which were identified by on-line LC-ESI-MS/MS, such as S100 calcium-binding protein,A4 (S100A4), annexin,1, etc., might have much application in diagnostic procedures and prognosis evaluation. S100A4, as a leading different metastasis candidate protein, which overexpressed only in the metastatic cells, was selected for further investigation. A series of assays related to invasion and metastasis in,vitro, including cell motility, invasion, and matrix metalloproteinases (MMPs) secretion, were performed in MHCC97H/antisense recombinant plasmid to S100A4 (pcDNA3.1(+) AS S100A4) and the mock controls. All the data in the present study suggested that S100A4 might contribute to HCC invasion and metastasis through two paths of matrix metalloproteinase (MMP9) secretion regulation and strengthened motility and invasion properties. [source] Identification of citrullinated vimentin peptides as T cell epitopes in HLA,DR4,positive patients with rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 1 2010Anouk L. Feitsma Objective Antibodies directed against citrullinated proteins (ACPAs) are highly specific for rheumatoid arthritis (RA). The production of ACPAs is most likely dependent on the presence of T cells, since ACPAs undergo isotype switching and are associated with the shared epitope (SE),containing HLA,DRB1 alleles. Vimentin is a likely candidate protein for T cell recognition, since >90% of patients positive for ACPAs that are reactive with (peptides derived from) citrullinated vimentin carry SE-containing HLA,DRB1 alleles. The aim of this study was to identify citrullinated vimentin peptides that are presented to HLA,DRB1*0401,restricted T cells. Methods HLA,DR4,transgenic mice were immunized with all possible citrulline-containing peptides derived from vimentin, and T cell reactivity was analyzed. Peptides recognized in a citrulline-specific manner by T cells were selected and analyzed for their ability to be processed from the entire vimentin protein. A first inventory of the selected epitopes recognized by T cells was performed using peripheral blood mononuclear cells (PBMCs) from ACPA+, HLA,DR4+ patients with RA. Results A citrulline-specific response was observed for 2 of the peptides analyzed in DR4-transgenic mice. These peptides were found to be naturally processed from the vimentin protein, since citrullinated vimentin was recognized by peptide-specific T cells. T cell reactivity against these peptides was also observed in cultures of PBMCs from RA patients. Conclusion This study identifies, for the first time, 2 naturally processed peptides from vimentin that are recognized by HLA,DRB1*0401,restricted T cells in a citrulline-specific manner. These peptides can be recognized by T cells in ACPA+, HLA,DR4+ patients with RA, as shown in a first inventory. [source] A novel T cell cytokine, secreted osteoclastogenic factor of activated T cells, induces osteoclast formation in a RANKL-independent mannerARTHRITIS & RHEUMATISM, Issue 11 2009Leonard Rifas Objective Chronic T cell activation is central to the etiology of rheumatoid arthritis (RA), an inflammatory autoimmune disease that leads to severe focal bone erosions and generalized systemic osteoporosis. Previous studies have shown novel cytokine-like activities in medium containing activated T cells, characterized by potent induction of the osteoblastic production of interleukin-6 (IL-6), an inflammatory cytokine and stimulator of osteoclastogenesis, as well as induction of an activity that directly stimulates osteoclast formation in a manner independent of the key osteoclastogenic cytokine RANKL. This study was undertaken to identify the factors secreted by T cells that are responsible for these activities. Methods Human T cells were activated using anti-human CD3 and anti-human CD28 antibodies for 72 hours in AIM V serum-free medium to obtain T cell,conditioned medium, followed by concentration and fractionation of the medium by fast-protein liquid chromatography. Biologically active fractions were resolved using sodium dodecyl sulfate,polyacrylamide gel electrophoresis. Major bands were analyzed by mass spectrometry, and a major candidate protein was identified. This novel cytokine was cloned, and its expression was analyzed using recombinant DNA technologies. Results A single novel cytokine that could induce both osteoblastic IL-6 production and functional osteoclast formation in the absence of osteoblasts or RANKL and that was insensitive to the effects of the RANKL inhibitor osteoprotegerin was identified in the activated T cell,conditioned medium; this cytokine was designated secreted osteoclastogenic factor of activated T cells (SOFAT). Further analysis of SOFAT revealed that it was derived from an unusual messenger RNA splice variant coded by the threonine synthase,like 2 gene homolog, which is a conserved gene remnant coding for threonine synthase, an enzyme that functions only in microorganisms and plants. Conclusion SOFAT may act to exacerbate inflammation and/or bone turnover under inflammatory conditions such as RA or periodontitis and in conditions of estrogen deficiency. [source] Proteomic profiling reveals a catalogue of new candidate proteins for human skin agingEXPERIMENTAL DERMATOLOGY, Issue 10 2010Martin Laimer Abstract:, Studies of skin aging are usually performed at the genomic level by investigating differentially regulated genes identified through subtractive hybridization or microarray analyses. In contrast, relatively few studies have investigated changes in protein expression of aged skin using proteomic profiling by two-dimensional (2-D) gel electrophoresis and mass spectrometry, although this approach at the protein level is suggested to reflect more accurately the aging phenotype. We undertook such a proteomic analysis of intrinsic human skin aging by quantifying proteins extracted and fluorescently labeled from sun-protected human foreskin samples pooled from ,young' and ,old' men. In addition, we analyzed these candidate gene products by 1-D and 2-D western blotting to obtain corroborative protein expression data, and by both real-time PCR (RT-PCR) and microarray analyses to confirm expression at the mRNA level. We discovered 30 putative proteins for skin aging, including previously unrecognized, post-translationally regulated candidates such as phosphatidyl-ethanolamine binding protein (PEBP) and carbonic anhydrase 1 (CA1). [source] Human neutrophil peptides 1,3 are useful biomarkers in patients with active ulcerative colitisINFLAMMATORY BOWEL DISEASES, Issue 6 2009Shuji Kanmura MD Abstract Background: A specific useful biomarker for diagnosing ulcerative colitis (UC) has not yet been described. This study employed proteomics to identify serum protein biomarkers for UC. Methods: Ninety-four blood samples were isolated from patients and controls (including 48 UC, 22 Crohn's disease [CD], 5 colorectal cancer, and 6 infectious colitis patients and 13 healthy subjects). Serum samples were analyzed using the SELDI-TOF/MS ProteinChip system. After applying the samples to ProteinChip arrays, we assessed differences in the proteomes using Ciphergen ProteinChip software and identified candidate proteins, which were then characterized in immunoassays. Results: Preliminary analysis using the ProteinChip system revealed significant peak-intensity differences for 27 serum proteins between 11 patients with UC and 7 healthy subjects. Among these proteins, 3 proteins (with mass/charge ratios of approximately 3400) were identified as human neutrophil peptides 1,3 (HNP 1,3). The presence of HNP 1,3 in the patient sera was confirmed using immunoassays. Enzyme-linked immunosorbent assays demonstrated that the mean plasma concentration of HNP 1,3 was significantly higher in patients with active UC (n = 28) than in patients whose UC was in remission (n = 20) or patients with CD (n = 22), infectious colitis, or healthy subjects, and tended to be higher than in patients with colon cancer. In addition, the plasma concentration of HNP 1,3 in patients that responded to corticosteroids-based therapy decreased after treatment, whereas it was not changed in nonresponders. Conclusions: HNP 1,3 is a novel biomarker that may be useful for diagnosing patients with active UC and predicting treatment outcomes. (Inflamm Bowel Dis 2008) [source] Calorie restriction alters mitochondrial protein acetylationAGING CELL, Issue 5 2009Bjoern Schwer Summary Calorie restriction (CR) increases lifespan in organisms ranging from budding yeast through mammals. Mitochondrial adaptation represents a key component of the response to CR. Molecular mechanisms underlying this adaptation are largely unknown. Here we show that lysine acetylation of mitochondrial proteins is altered during CR in a tissue-specific fashion. Via large-scale mass spectrometry screening, we identify 72 candidate proteins involved in a variety of metabolic pathways with altered acetylation during CR. Mitochondrial acetylation changes may play an important role in the pro-longevity CR response. [source] Histamine-induced Ca2+ entry in human astrocytoma U373 MG cells: Evidence for involvement of store-operated channelsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 15 2008Margarita Barajas Abstract Glial and glia-derived cells express a variety of receptors for neurotransmitters and hormones, the majority of which evoke both Ca2+ release from intracellular stores and Ca2+ entry across the plasma membrane. We investigated the links between histamine H1 receptor activation, Ca2+ release from intracellular stores and Ca2+ influx in human astrocytoma U373 MG cells. Histamine, through a H1 receptor-mediated effect, evoked an increase in cytoplasmic free calcium concentration ([Ca2+]i) that occurred in two phases: an initial, transient, increase owing to Ca2+ mobilization from intracellular pools, and a second, sustained increase dependent on both Ca2+ influx and continuous receptor occupancy. The characteristics of histamine-induced increases in [Ca2+]i were similar to the capacitative entry evoked by emptying of the Ca2+ stores with thapsigargine, and different from that observed when Ca2+ influx was activated with OAG (1-oleoyl-2-acetyl- sn -glycerol), a diacylglycerol (DAG) analog. OAG application or increased endogenous DAG, resulting from DAG kinase inhibition, reduced the histamine-induced response. Furthermore, activation of the DAG target, protein kinase C (PKC), by TPA (12-O-tetradecanoyl 4,-phorbol 13,-acetate) resulted in inhibition of the histamine-induced Ca2+ response, an action prevented by PKC inhibitors. By using reverse transcriptase,polymerase chain reaction analysis, mRNAs for transient receptor potential channels (TRPCs) 1, 4, and 6 as well as for STIM1 (stromal-interacting molecule) and Orai1 were found to be expressed in the U373 MG cells, and confocal microscopy using specific antibodies revealed the presence of the corresponding proteins. Therefore, TRPCs may be candidate proteins forming store-operated channels in the U373 MG cell line. Further, our results confirm the involvement of PKC in the regulation of H1 receptor-induced responses and point out to the existence of a feedback mechanism acting via PKC to limit the increase in [Ca2+]i. © 2008 Wiley-Liss, Inc. [source] Regulation of insulin action by an extract of Artemisia dracunculus L. in primary human skeletal muscle culture: A proteomics approach,PHYTOTHERAPY RESEARCH, Issue 9 2010Indu Kheterpal Abstract An ethanolic extract of Artemisia dracunculus L. (PMI 5011) has been observed to decrease glucose and insulin levels in animal models and enhance cellular signaling in cultured cells. To determine the mechanism of action of PMI-5011, we have measured changes in protein expression in human primary skeletal muscle culture (HSMC) from subjects with Type 2 diabetes. After obtaining skeletal muscle biopsies, HSMCs were initiated, grown to confluence, and exposed to 10,µg/mL PMI 5011 overnight. Two-dimensional difference in-gel electrophoresis was used to separate proteins, and liquid chromatography mass spectrometry was used to identify differentially regulated proteins. Additionally, real-time polymerase chain reaction (PCR) was used to confirm candidate proteins identified. These data demonstrate that a well characterized botanical extract of Artemisia dracunculus L. significantly modulates proteins involved in regulating inflammatory pathways, particularly the NF,B complex system. Copyright © 2010 John Wiley & Sons, Ltd. [source] Proteomics reveals lowering oxygen alters cytoskeletal and endoplasmatic stress proteins in human endothelial cellsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2009Louise Østergaard Abstract A proteomic approach was applied to explore the signalling pathways elicited by lowering O2 in endothelial cells. Endothelial cells isolated from native umbilical cords were subjected to 21, 5, or 1% O2 for 24,h. 2-D PAGE was performed and candidate proteins were identified using LC-MS/MS. Lowering of O2 from 21 to 5% induced upregulation of cofilin-1, cyclophilin A, tubulin and tubulin fragments, a fragment of glucose-regulated protein 78 (Grp78) and calmodulin. The upregulation of Grp78 suggested that ER stress proteins were altered and indeed Grp94 and caspase 12 expression were increased in cells exposed to 5% O2. The presence of ER stress is also supported by findings of blunted caffeine-evoked ER calcium release in cells exposed to 5 and 1% O2. Exposure to 1% O2 caused increases in cofilin-1, cyclophilin A, and caspase 12 as well as a decrease of ,-actin, but it did not alter the expression of calmodulin, tubulin, Grp78, and Grp94. Incubation with CoCl2, a stabilizer of the hypoxia-inducible factor, increased the expression of several of the proteins. The present investigations reveal that lowering O2, probably in part through hypoxia-inducible factor, alter the expression of a series of proteins mainly involved in cytoskeletal changes (e.g. cofilin-1, tubulin, and ,-actin) and in ER stress/apoptosis (e.g. Grp78/94, caspase 12, and cyclophilin A). [source] Proteomic analysis of cells in the early stages of herpes simplex virus type-1 infection reveals widespread changes in the host cell proteomePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 15 2009Robin Antrobus Abstract During infection by herpes simplex virus type-1 (HSV-1) the host cell undergoes widespread changes in gene expression and morphology in response to viral replication and release. However, relatively little is known about the specific proteome changes that occur during the early stages of HSV-1 replication prior to the global damaging effects of virion maturation and egress. To investigate pathways that may be activated or utilised during the early stages of HSV-1 replication, 2-DE and LC-MS/MS were used to identify cellular proteome changes at 6,h post infection. Comparative analysis of multiple gels representing whole cell extracts from mock- and HSV-1-infected HEp-2 cells revealed a total of 103 protein spot changes. Of these, 63 were up-regulated and 40 down-regulated in response to infection. Changes in selected candidate proteins were verified by Western blot analysis and their respective cellular localisations analysed by confocal microscopy. We have identified differential regulation and modification of proteins with key roles in diverse cellular pathways, including DNA replication, chromatin remodelling, mRNA stability and the ER stress response. This work represents the first global comparative analysis of HSV-1 infected cells and provides an important insight into host cell proteome changes during the early stages of HSV-1 infection. [source] Ratio-dependent significance thresholds in reciprocal 15N-labeling experiments as a robust tool in detection of candidate proteins responding to biological treatmentPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2009Sylwia Kierszniowska Abstract Metabolic labeling of plant tissues with 15N has become widely used in plant proteomics. Here, we describe a robust experimental design and data analysis workflow implementing two parallel biological replicate experiments with reciprocal labeling and series of 1:1 control mixtures. Thereby, we are able to unambiguously distinguish (i) inherent biological variation between cultures and (ii) specific responses to a biological treatment. The data analysis workflow is based on first determining the variation between cultures based on 15N/14N ratios in independent 1:1 mixtures before biological treatment is applied. In a second step, ratio-dependent SD is used to define p -values for significant deviation of protein ratios in the biological experiment from the distribution of protein ratios in the 1:1 mixture. This approach allows defining those proteins showing significant biological response superimposed on the biological variation before treatment. The proposed workflow was applied to a series of experiments, in which changes in composition of detergent resistant membrane domains was analyzed in response to sucrose resupply after carbon starvation. Especially in experiments involving cell culture treatment (starvation) prior to the actual biological stimulus of interest (resupply), a clear distinction between culture to culture variations and biological response is of utmost importance. [source] Lectin precipitation using phytohemagglutinin-L4 coupled to avidin,agarose for serological biomarker discovery in colorectal cancerPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 16 2008Yong-Sam Kim Abstract N -acetylglucosaminyltransferase V (GnT-V) has been reported to be upregulated in malignant cancer cells, and its targets have been sought after with regard to biomarker identification. The low capacity and high false positive rates of 2-DE gel-based lectin blots using phytohemagglutinin-L4 (L-PHA) prompted us to develop a novel protocol for identifying GnT-V targets, in which serum proteins were subjected to immunodepletion, alkylation, and lectin precipitation using L-PHA coupled to avidin,agarose bead complexes, and tryptic digestion. Proteins captured by L-PHA conjugates were analyzed by a nano-LC-FT-ICR/LTQ MS. Here, we report 26 candidate biomarkers for colorectal cancer (CRC) that show 100% specificity and sensitivities of greater than 50%. Not only can these candidate proteins be used as analytes for validation, but the novel protocol described herein can be applied to biomarker discovery in nonCRCs. [source] Identification of metastasis candidate proteins among HCC cell lines by comparative proteome and biological function analysis of S100A4 in metastasis in vitroPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 22 2006Jie Feng Cui Abstract Widespread metastasis of hepatocellular carcinoma,(HCC) was a complex cascade of events, which is still beyond full appreciation. Screening key proteins, which play a critical role in metastasis, using high-throughput proteomics approach help discover valuable biomarkers and elucidate the mechanism of metastasis. This study was to find out some metastasis candidate proteins among HCC cell lines with various metastatic potential by comparative proteomics, and then further validate the biological function of these proteins in metastasis in,vitro. The protein profiles of metastatic HCC cell lines (MHCC97H and MHCC97L) displayed obvious differences compared with nonmetastatic ones (Hep3B). Twenty-six metastasis candidate proteins, which were identified by on-line LC-ESI-MS/MS, such as S100 calcium-binding protein,A4 (S100A4), annexin,1, etc., might have much application in diagnostic procedures and prognosis evaluation. S100A4, as a leading different metastasis candidate protein, which overexpressed only in the metastatic cells, was selected for further investigation. A series of assays related to invasion and metastasis in,vitro, including cell motility, invasion, and matrix metalloproteinases (MMPs) secretion, were performed in MHCC97H/antisense recombinant plasmid to S100A4 (pcDNA3.1(+) AS S100A4) and the mock controls. All the data in the present study suggested that S100A4 might contribute to HCC invasion and metastasis through two paths of matrix metalloproteinase (MMP9) secretion regulation and strengthened motility and invasion properties. [source] Changes in the rat heart proteome induced by exercise training: Increased abundance of heat shock protein hsp20PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 10 2006Marvin O. Boluyt Dr. Abstract Chronic exercise training elicits adaptations in the heart that improve pump function and confer cardioprotection. To identify molecular mechanisms by which exercise training stimulates this favorable phenotype, a proteomic approach was employed to detect rat cardiac proteins that were differentially expressed or modified after exercise training. Exercise-trained rats underwent six weeks of progressive treadmill training five days/week, 0%,grade, using an interval training protocol. Sedentary control rats were age- and weight-matched to the exercise-trained rats. Hearts were harvested at various times (0,72,h) after the last bout of exercise and were used to generate 2-D electrophoretic proteome maps and immunoblots. Compared with hearts of sedentary rats, 26,protein spot intensities were significantly altered in hypertrophied hearts of exercise-trained rats (p,<0.05), and 12,spots appeared exclusively on gels from hearts of exercise-trained rats. Immunoblotting confirmed that chronic exercise training, but not a single bout of exercise, elicited a ,2.5-fold increase in the abundance of one of the candidate proteins in the heart, a ,20,kDa heat shock protein (hsp20) that persisted for at least 72,h of detraining. Thus, exercise training alters the cardiac proteome of the rat heart; the changes include a marked increase in the expression of hsp20. [source] High-resolution biomarker discovery: Moving from large-scale proteome profiling to quantitative validation of lead candidatesPROTEOMICS - CLINICAL APPLICATIONS, Issue 10-11 2008Johannes A. Hewel Abstract Diverse proteomic techniques based on protein MS have been introduced to systematically characterize protein perturbations associated with disease. Progress in clinical proteomics is essential for personalized medicine, wherein treatments will be tailored to individual needs based on patient stratification using noninvasive disease monitoring procedures to reveal the most appropriate therapeutic targets. However, breakthroughs await the successful development and application of a robust proteomic pipeline capable of identifying and rigorously assessing the relevance of multiple candidate proteins as informative diagnostic and prognostic indicators or suitable drug targets involved in a pathological process. While steady progress has been made toward more comprehensive proteome profiling, the emphasis must now shift from in depth screening of reference samples to stringent quantitative validation of selected lead candidates in a broader clinical context. Here, we present an overview of the emerging proteomic strategies for high-throughput protein detection focused primarily on targeted MS/MS as the basis for biomarker verification in large clinical cohorts. We discuss the conceptual promise and practical pitfalls of these methods in terms of achieving higher dynamic range, higher throughput, and more reliable quantification, highlighting research avenues that merit additional inquiry. [source] Immunocytochemical localization of synaptic proteins to photoreceptor synapses of Drosophila melanogasterTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 7 2010Yoshitaka Hamanaka Abstract The location of proteins that contribute to synaptic function has been widely studied in vertebrate synapses, far more than at model synapses of the genetically manipulable fruit fly, Drosophila melanogaster. Drosophila photoreceptor terminals have been extensively exploited to characterize the actions of synaptic genes, and their distinct and repetitive synaptic ultrastructure is anatomically well suited for such studies. Synaptic release sites include a bipartite T-bar ribbon, comprising a platform surmounting a pedestal. So far, little is known about the composition and precise location of proteins at either the T-bar ribbon or its associated synaptic organelles, knowledge of which is required to understand many details of synaptic function. We studied the localization of candidate proteins to pre- or postsynaptic organelles, by using immuno-electron microscopy with the pre-embedding method, after first validating immunolabeling by confocal microscopy. We used monoclonal antibodies against Bruchpilot, epidermal growth factor receptor pathway substrate clone 15 (EPS-15), and cysteine string protein (CSP), all raised against a fly head homogenate, as well as sea urchin kinesin (antibody SUK4) and Discs large (DLG). All these antibodies labeled distinct synaptic structures in photoreceptor terminals in the first optic neuropil, the lamina, as did rabbit anti-DPAK (Drosophila p21 activated kinase) and anti-Dynamin. Validating reports from light microscopy, immunoreactivity to Bruchpilot localized to the edge of the platform, and immunoreactivity to SUK4 localized to the pedestal of the T-bar ribbon. Anti-DLG recognized the photoreceptor head of capitate projections, invaginating organelles from surrounding glia. For synaptic vesicles, immunoreactivity to EPS-15 localized to sites of endocytosis, and anti-CSP labeled vesicles lying close to the T-bar ribbon. These results provide markers for synaptic sites, and a basis for further functional studies. J. Comp. Neurol. 518:1133,1155, 2010. © 2009 Wiley-Liss, Inc. [source] Mutants in DEFECTIVE GLYCOSYLATION, an Arabidopsis homolog of an oligosaccharyltransferase complex subunit, show protein underglycosylation and defects in cell differentiation and growthTHE PLANT JOURNAL, Issue 4 2005Olivier Lerouxel Summary A mutant called defective glycosylation1-1 (dgl1-1) was identified in Arabidopsis based on a growth defect of the dark-grown hypocotyl and an abnormal composition of the non-cellulosic cell wall polysaccharides. dgl1-1 is altered in a protein ortholog of human OST48 or yeast WBP1, an essential protein subunit of the oligosaccharyltransferase (OST) complex, which is responsible for the transfer in the ER of the N-linked glycan precursor onto Asn residues of candidate proteins. Consistent with the known function of the OST complex in eukaryotes, the dgl1-1 mutation led to a reduced N-linked glycosylation of the ER-resident protein disulfide isomerase. A second more severe mutant (dgl1-2) was embryo-lethal. Microscopic analysis of dgl1-1 revealed developmental defects including reduced cell elongation and the collapse and differentiation defects of cells in the central cylinder. These defects were accompanied by changes in the non-cellulosic polysaccharide composition, including the accumulation of ectopic callose. Interestingly, in contrast to other dwarf mutants that are altered in early steps of the N -glycan processing, dgl1-1 did not exhibit a cellulose deficiency. Together, these results confirm the role of DGL1 in N-linked glycosylation, cell growth and differentiation in plants. [source] Biomarkers for Cognitive Impairment in Parkinson DiseaseBRAIN PATHOLOGY, Issue 3 2010Min Shi Abstract Cognitive impairment, including dementia, is commonly seen in those afflicted with Parkinson disease (PD), particularly at advanced disease stages. Pathologically, PD with dementia (PD-D) is most often associated with the presence of cortical Lewy bodies, as is the closely related dementia with Lewy bodies (DLB). Both PD-D and DLB are also frequently complicated by the presence of neurofibrillary tangles and amyloid plaques, features most often attributed to Alzheimer disease. Biomarkers are urgently needed to differentiate among these disease processes and predict dementia in PD as well as monitor responses of patients to new therapies. A few clinical assessments, along with structural and functional neuroimaging, have been utilized in the last few years with some success in this area. Additionally, a number of other strategies have been employed to identify biochemical/molecular biomarkers associated with cognitive impairment and dementia in PD, e.g. targeted analysis of candidate proteins known to be important to PD pathogenesis and progression in cerebrospinal fluid or blood. Finally, interesting results are emerging from preliminary studies with unbiased and high throughput genomic, proteomic and metabolomic techniques. The current findings and perspectives of applying these strategies and techniques are reviewed in this article, together with potential areas of advancement. [source] | |||||||||||||