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Regional Expression (regional + expression)
Selected AbstractsRegional expression of MTG genes in the developing mouse central nervous systemDEVELOPMENTAL DYNAMICS, Issue 8 2009Amin Alishahi Abstract Myeloid translocation gene (MTG) proteins are transcriptional repressors that are highly conserved across species. We studied the expression of three members of this gene family, MTGR1, MTG8, and MTG16 in developing mouse central nervous system by in situ hybridization. All of these genes are detected as early as embryonic day 11.5. Because these genes are known to be induced by proneural genes during neurogenesis, we analyzed the expression of MTG genes in relation to two proneural genes, Neurog2 (also known as Ngn2 or Neurogenin 2) and Ascl1 (also known as Mash1). While MTGR1 are generally expressed in regions that also express Neurog2, MTG8 and MTG16 expression is associated more tightly with that of Ascl1 -expressing neural progenitor cells. These results suggest the possibility that expression of MTG genes is differentially controlled by specific proneural genes during neurogenesis. Developmental Dynamics 238:2095,2102, 2009. © 2009 Wiley-Liss, Inc. [source] Immunohistochemical study of the expression of cytokines and nitric oxide synthases in brains of patients with dementia with Lewy bodiesNEUROPATHOLOGY, Issue 1 2003Omi Katsuse Regional expression of cytokines (IL-1,, TNF-,), inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS) was immunohistochemically investigated in the brains of patients with dementia with Lewy bodies (DLB), compared with those of patients with Alzheimer's disease (AD) and non-demented elderly persons. It has been reported that inflammatory responses by cytokines and oxygen free radicals such as nitric oxide (NO) are associated with damaged neurons, degenerative neurites or amyloid deposits in AD brains. In the present study, overexpression of IL-1,, TNF-, and iNOS was demonstrated in the amygdala, hippocampus, entorhinal and insular cortices of DLB brains, which are pathologically the most vulnerable regions in DLB brains as well as AD brains. In addition, some Lewy body (LB)-bearing neurons were involved by the processes of IL-1,- and TNF-,-positive microglia, and most extracellular LB were associated with the processes of TNF-,- and iNOS-positive astroglia. Glial involvement was also found around neuritic plaques and extracellular neurofibrillary tangles. In contrast, the expression of nNOS was reduced in the amygdala of DLB brains showing severe Lewy pathology. These findings suggest that cytokines and NO are significantly implicated in neuronal damage and death including LB formation in DLB brains. [source] Mechanotransduction of bovine articular cartilage superficial zone protein by transforming growth factor , signalingARTHRITIS & RHEUMATISM, Issue 11 2007Corey P. Neu Objective Mechanical signals are key determinants in tissue morphogenesis, maintenance, and restoration strategies in regenerative medicine, although molecular mechanisms of mechanotransduction remain to be elucidated. This study was undertaken to investigate the mechanotransduction process of expression of superficial zone protein (SZP), a critical joint lubricant. Methods Regional expression of SZP was first quantified in cartilage obtained from the femoral condyles of immature bovines, using immunoblotting, and visualized by immunohistochemistry. Contact pressure mapping in whole joints was accomplished using pressure-sensitive film and a load application system for joint testing. Friction measurements on cartilage plugs were acquired under boundary lubrication conditions using a pin-on-disk tribometer modified for reciprocating sliding. Direct mechanical stimulation by shear loading of articular cartilage explants was performed with and without inhibition of transforming growth factor , (TGF,) signaling, and SZP content in media was quantified by enzyme-linked immunosorbent assay. Results An unexpected pattern of SZP localization in knee cartilage was initially identified, with anterior regions exhibiting high levels of SZP expression. Regional SZP patterns were regulated by mechanical signals and correlated with tribological behavior. Direct relationships were demonstrated between high levels of SZP expression, maximum contact pressures, and low friction coefficients. Levels of SZP expression and accumulation were increased by applying shear stress, depending on location within the knee, and were decreased to control levels with the use of a specific inhibitor of TGF, receptor type I kinase and subsequent phospho-Smad2/3 activity. Conclusion These findings indicate a new role for TGF, signaling in the mechanism of cellular mechanotransduction that is especially significant for joint lubrication. [source] Climate variability in Malawi, part 1: dry summers, statistical associations and predictabilityINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2002M. R. Jury Abstract Climate variability and predictability over tropical southern Africa is studied using a Malawi summer rainfall index. Thermodynamic and circulation patterns are examined and statistical associations are analysed. Links with El Niño,southern oscillation (ENSO) and quasi-biennial oscillation (QBO) phase are significant and consistent with those found for southern Africa. Correlations are mapped with respect to the Malawi rainfall index, and the regional expression of ENSO emerges quite clearly. Negative r values for sea-surface temperature (SST) in the west Indian Ocean contrast with positive r values in the east Atlantic and Agulhas region. The thermodynamic pattern ,anchors' a standing Rossby wave, comprised of northwest,southeast-oriented centres of action across the Mozambique Channel and southern Africa, and east of Madagascar to East Africa. A meandering of the sub-tropical jet stream is an expression of the standing Rossby wave, leading to vertical motions over southern Africa. The pattern develops at least one season in advance, and predictive indices are extracted in the July,September season for use in a multivariate model to predict the Malawi summer rainfall. The three-area SST index, formulated to capture the ENSO-modulated Rossby wave pattern, is the most influential predictor, followed by air pressure over the east Indian Ocean and the stratospheric zonal wind anomaly (QBO). Skilful results are found, with a 55% hindcast fit and two-thirds of tercile categories correctly forecast in independent tests. Copyright © 2002 Royal Meteorological Society. [source] Proteomic analysis of nuclear factors binding to an intronic enhancer in the myelin proteolipid protein geneJOURNAL OF NEUROCHEMISTRY, Issue 5 2008Anna Dobretsova Abstract The myelin proteolipid protein gene (Plp1) encodes the most abundant protein found in CNS myelin, accounting for nearly one-half of the total protein. Its expression in oligodendrocytes is developmentally regulated , peaking during the active myelination period of CNS development. Previously, we have identified a novel enhancer (designated ASE) in intron 1 DNA that appears to be important in mediating the surge of Plp1 gene activity during the active myelination period. Evidence suggests that the ASE participates in the formation of a specialized multi-protein/DNA complex called an enhanceosome. The current study describes an optimized, five-step, DNA affinity chromatography purification procedure to purify nuclear proteins from mouse brain that bind to the 85-bp ASE sequence, specifically. Electrophoretic mobility shift assay analysis demonstrated that specific DNA-binding activity was retained throughout the purification procedure, resulting in concomitant enrichment of nucleoprotein complexes. Identification of the purported regulatory factors was achieved through mass spectrometry analysis and included over 20 sequence-specific DNA-binding proteins. Supplementary western blot analyses to determine which of these sequence-specific factors are present in oligodendrocytes, and their developmental and regional expression in whole brain, suggest that Pur, and Pur, rank highest among the candidate factors as constituents of the multi-protein complex formed on the ASE. [source] Region-Specific Expression and Hormonal Regulation of the First Exon Variants of Rat Prolactin Receptor mRNA in Rat Brain and Anterior Pituitary GlandJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2007H. Nogami Recent studies have revealed the occurrence of five first exon variants of the rat prolactin receptor mRNA, suggesting that multiple promoters direct prolactin receptor transcription in response to different regulatory factors. In the present study, regional expression of these first exon variants, as well as two prolactin receptor subtypes generated by alternative splicing, was examined in the brains and anterior pituitary glands of female rats. Expression of the long-form was detected in the choroid plexus, hypothalamus, hippocampus, cerebral cortex and anterior pituitary gland, whereas the short form was detected only in the choroid plexus. E1-3 mRNA, a first exon variant, was detected in the choroid plexus, hypothalamus, and anterior pituitary gland, whereas E1-4 was detected only in the choroid plexus. Other variants were not detectable by the polymerase chain reaction protocol employed in this study. Ovariectomy increased the short form in the choroid plexus and the E1-3 expression in the choroid plexus and pituitary gland, but changes in the long-form and E1-4 expression were minimal. Replacement of oestrogens and prolactin suggest that oestrogens down-regulate E1-3 expression in the choroid plexus and pituitary gland, and that the negative effect of oestrogen is mediated by prolactin in the pituitary gland. The present results revealed the region-specific promoter usage in prolactin receptor mRNA transcription, as well as the involvement of oestrogens in the regulation of E1-3 mRNA expression in the brain and pituitary gland. [source] Docking and homology modeling explain inhibition of the human vesicular glutamate transportersPROTEIN SCIENCE, Issue 9 2007Jonas Almqvist Abstract As membrane transporter proteins, VGLUT1,3 mediate the uptake of glutamate into synaptic vesicles at presynaptic nerve terminals of excitatory neural cells. This function is crucial for exocytosis and the role of glutamate as the major excitatory neurotransmitter in the central nervous system. The three transporters, sharing 76% amino acid sequence identity in humans, are highly homologous but differ in regional expression in the brain. Although little is known regarding their three-dimensional structures, hydropathy analysis on these proteins predicts 12 transmembrane segments connected by loops, a topology similar to other members in the major facilitator superfamily, where VGLUT1,3 have been phylogenetically classified. In this work, we present a three-dimensional model for the human VGLUT1 protein based on its distant bacterial homolog in the same superfamily, the glycerol-3-phosphate transporter from Escherichia coli. This structural model, stable during molecular dynamics simulations in phospholipid bilayers solvated by water, reveals amino acid residues that face its pore and are likely to affect substrate translocation. Docking of VGLUT1 substrates to this pore localizes two different binding sites, to which inhibitors also bind with an overall trend in binding affinity that is in agreement with previously published experimental data. [source] | |||||||||||||