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At least 1,207 records · Page 67Linked to original sources
PubMed2004

Expression pattern of the JAB1/CSN5 gene during murine embryogenesis: colocalization with NEDD8.

The COP9 signalosome (CSN) is a conserved multiprotein complex, with an important developmental role in several organisms, ranging from plants to mammalians. The influence of the CSN on several signaling and developmental processes has been ascribed to its ability to regulate degradation of a number of signaling proteins by the ubiquitin-proteasome system. The CSN controls the function of the SCF ubiquitin-ligase complex through an enzymatic activity that removes the small ubiquitin-like molecule NEDD8 from the cullin component of the SCF and that requires subunit 5 of the CSN (JAB1/CSN5). Mutants of the CSN display early embryonic lethality, a feature that has hindered further characterization of the role of the CSN at later stages of mammalian development. Here we report the analysis of JAB1/CSN5 expression pattern in the mouse embryo. At early stages of development, JAB1/CSN5 transcripts were present with low expression levels in all tissues. Preferential expression in selected tissues was detected starting at E11.5, with higher levels in dorsal root ganglia; at later stages, prominent expression of JAB1/CSN5 transcripts was observed in cranial nerve, spinal and sympathetic ganglia, as well as in selected epithelia, such as the oral and the olfactory epithelium. In the adult brain, additional areas of JAB1/CSN5 expression were the hippocampus and the Purkinjie layer of the cerebellum. We also analyzed the temporal and spatial expression pattern of NEDD8, and found that it substantially overlapped JAB1/CSN5 expression at all stages analyzed, supporting the model of a functional interaction between the two proteins during developmental processes.

Animals↗
PubMed2004

Fos protein expression in mouse hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei upon osmotic stimulus: colocalization with vasopressin, oxytocin, and tyrosine hydroxylase.

The quantity and topography of activated vasopressin (AVP), oxytocin (OXY), and tyrosine hydroxylase (TH) neurons were studied immunohistochemically in the anterior, middle, and posterior portions of the PVN and SON in mice 60 min after a single injection of hypertonic saline (HS, 400 microl 1.5M, i.p.). Fos-neuropeptide double-stainings revealed: (1) Fos expression in each portion of the PVN and SON; (2) maximal number of Fos-AVP (79 cells) and Fos-OXY (50 cells) double-labelings in the middle portion of the PVN; (3) low number of Fos-TH perikarya in the PVN and their lack in the SON; (4) similar incidence (around 50%) of Fos-AVP and Fos-OXY perikarya in the SON; and (5) presence of activated AVP, OXY, and TH neurons in the periventricular, subependymal, and sub-PVN zones of the PVN. Topographic analysis revealed that the majority of AVP neurons expressing Fos occupied the dorsolateral and central part of the middle portion of the PVN. In the same PVN portion, Fos-OXY neurons occurred in similar frequency, however, they were primarily distributed along the lateral and medial margins of the PVN. In the SON, Fos-OXY cells occupied mainly its dorsal, while Fos-AVP cells predominated in its ventral part. The data clearly indicate that HS is not a selective stimulus neither for PVN nor SON itself and provide evidence that both PVN and SON AVP and OXY cells play important role in the mediation of signals induced by HS. In addition, the limited number of AVP, OXY, and TH neurons activated by HS may account for their differential functional specializations selective for stress/osmotic circuits activated by HS.

Animals↗
PubMed2004

Upregulation and colocalization of p75 and Nav1.8 in Purkinje neurons in experimental autoimmune encephalomyelitis.

Recent studies have indicated that, in addition to demyelination and axonal degeneration, a third factor, dysregulated ion channel expression, contributes to the pathophysiology of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS). Consistent with this suggestion, upregulated expression of sodium channel Na(v)1.8 is observed in Purkinje neurons in EAE and MS, and biophysical studies indicate that aberrant expression of Na(v)1.8 produces abnormal Purkinje cell firing which may contribute to the development of cerebellar ataxia. However, the molecular mechanisms that contribute to the upregulation of Na(v)1.8 in Purkinje cells in EAE and MS have not yet been determined. Previous studies have shown that neurotrophic factors can modulate sodium channel expression and that elevated levels of NGF are present in EAE and MS. Using immunocytochemical methods, we examined the relationship between the upregulation of Na(v)1.8 and the expression of the NGF receptors p75 and TrkA in EAE. Here we demonstrate that upregulation of Na(v)1.8 is associated with expression of p75 and low levels of TrkA in the majority of Purkinje cells in EAE. These findings, together with previous studies demonstrating a modulatory role of NGF on sodium channel expression, suggest that NGF acting via p75 contributes to the upregulation of Na(v)1.8 in Purkinje cells in EAE.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Overall distribution of GLYT2 mRNA-containing versus GAD67 mRNA-containing neurons and colocalization of both mRNAs in midbrain, pons, and cerebellum in rats.

We aimed to clarify the overall distribution of glycinergic neurons in the midbrain, pons, and cerebellum in rats, using in situ hybridization for mRNA encoding glycine transporter 2 (GLYT2), which reliably detects glycinergic cell bodies. We combined this method with in situ hybridization for mRNA encoding glutamic acid decarboxylase isoform 67 (GAD67), and have presented for the first time global and detailed views of the distribution of glycinergic neurons in relation to GABAergic neurons. In addition to this single-detection study, we performed double-detection of GLYT2 mRNA and GAD67 mRNA to determine the distribution of neurons co-expressing these mRNAs. We have shown that many areas of the brainstem and cerebellum, not only areas where previous immunohistochemical studies have specified, involve double-labeled neurons with GLYT2 and GAD67 mRNAs. In particular, when lightly labeled GLYT2 mRNA-positive neurons were distributed within the area of GAD67 mRNA-positive neurons, almost all such GLYT2 mRNA-positive neurons were GAD67 mRNA-positive. Areas or neuron groups expressing exclusively GLYT2 mRNA or GAD67 mRNA were rather limited, such as the superior colliculus, nucleus of the trapezoid body, and Purkinje cells. The present study suggests that the corelease of glycine and GABA from single neurons is more widespread than has been reported.

Amino Acid Transport Systems, Neutral↗
PubMed2006

Sensory system-predominant distribution of leukotriene A4 hydrolase and its colocalization with calretinin in the mouse nervous system.

Leukotriene B4 is a potent lipid mediator, which has been identified as a potent proinflammatory and immunomodulatory compound. Although there has been robust evidence indicating that leukotriene B4 is synthesized in the normal brain, detailed distribution and its functions in the nervous system have been unclear. To obtain insight into the possible neural function of leukotriene B4, we examined the immunohistochemical distribution of leukotriene A4 hydrolase, an enzyme catalyzing the final and committed step in leukotriene B4 biosynthesis, in the mouse nervous system. Immunoreactivity for leukotriene A4 hydrolase showed widespread distribution with preference to the sensory-associated structures; i.e. neurons in the olfactory epithelium and vomeronasal organ, olfactory glomeruli, possibly amacrine cells, neurons in the ganglion cell layer and three bands in the inner plexiform layer of the retina, axons in the optic nerve and tract up to the superior colliculus, inner and outer hair cells and the spiral ganglion cells in the cochlea, vestibulocochlear nerve bundle, spinal trigeminal tract, and lamina II of the spinal cord. Double immunofluorescence staining demonstrated that most of the leukotriene A4-hydrolase-immunopositive neurons coexpressed calretinin, a calcium-binding protein in neurons. The ubiquitous distribution of leukotriene A4 hydrolase was in sharp contrast with the distribution of leukotriene C4 synthase [Shimada A, Satoh M, Chiba Y, Saitoh Y, Kawamura N, Keino H, Hosokawa M, Shimizu T (2005) Highly selective localization of leukotriene C4 synthase in hypothalamic and extrahypothalamic vasopressin systems of mouse brain. Neuroscience 131:683-689] which was confined to the hypothalamic and extrahypothalamic vasopressinergic neurons. These results suggest that leukotriene B4 may exert some neuromodulatory function mainly in the sensory nervous system, in concert with calretinin.

Animals↗
PubMed2006

Caspase-3 cleaved spectrin colocalizes with neurofilament-immunoreactive neurons in Alzheimer's disease.

Corticocortical disconnection in Alzheimer's disease occurs by the progressive impairment and eventual loss of a small subset of pyramidal neurons in layers III and V of association areas of the neocortex. These neurons exhibit large somatic size, extensive dendritic arborization and high levels of nonphosphorylated neurofilaments of medium and high molecular weight that can be identified using a monoclonal SMI-32 antibody. It is thought that the accumulation of amyloid Abeta and neurofibrillary tangles may provoke metabolic disturbances that result in the loss of these SMI-32 immunoreactive neurons. The recent detection of increased levels of caspase-3 cleaved fodrin in frontal, temporal and parietal association areas in Alzheimer's disease brains suggests that programmed cell death may contribute to the destruction of SMI-32 positive neurons. In the present study, we utilized an antibody that selectively recognizes the 120 kDa breakdown product of alphaIIspectrin (fodrin) generated by caspase-3 to determine whether this protease is activated in vulnerable pyramidal neurons located in layers III and V of Alzheimer's disease brains. Neurons immunoreactive for caspase-3 cleaved alphaIIspectrin were located predominantly in layers III and V of the inferior frontal and superior temporal cortices of patients with Alzheimer's disease but not age-matched controls. Pyramidal neurons immunoreactive for caspase-3 cleaved alphaIIspectrin invariably displayed SMI-32 immunoreactivity suggesting that caspase-3 activation is a pathological event that may be responsible for the loss of a subset of pyramidal neurons that comprise corticocortical projections.

Aged↗
PubMed2002

Immunohistochemical colocalization of Yellow and male-specific Fruitless in Drosophila melanogaster neuroblasts.

The Drosophila melanogaster fruitless gene encodes multiple male-specific transcription factors that are hypothesized to regulate a hierarchy of genes responsible for the development of male courtship behavior. Here we show that there are dramatically increased levels of the protein product of the male courtship behavior gene yellow associated with male-specific Fruitless protein in a subset of neuroblasts in third-instar larval male brains. We hypothesize that yellow is downstream of fruitless in a male courtship behavior developmental genetic pathway.

Animals↗
PubMed2002

Calpain II colocalizes with detergent-insoluble rafts on human and Jurkat T-cells.

Calpain, a calcium-dependent cysteine protease, is known to associate with the T-cell plasma membrane and subsequently cleave a number of cytoskeletal-associated proteins. In this study, we report the novel observation that calpain II, but not calpain I, associates with membrane lipid rafts on human peripheral blood T-cells and Jurkat cells. Raft-associated calpain activity is enhanced with exogenous calcium and inhibited with calpeptin, a specific inhibitor of calpain activity. In addition, we demonstrate that calpain cleaves the cytoskeletal-associated protein, talin, during the first 30-min after cell stimulation. We propose that lipid raft associated-calpain II could function in early TCR signaling to facilitate immune synapse formation through cytoskeletal remodeling mechanisms. Hence, we demonstrate that the positioning of calpain II within T-cell lipid rafts strategically places it in close proximity to known calpain substrates that are cleaved during Ag-specific T-cell signaling and immune synapse formation.

Calpain↗
PubMed1999

Determining the activation time course of synaptic AMPA receptors from openings of colocalized NMDA receptors.

Excitatory postsynaptic currents (EPSCs) in most mammalian central neurons have a fast alpha-amino-3-hydroxy-5-methyl-4-isoazole-proprionic acid (AMPA) receptor-mediated component, lasting a few milliseconds, and a slow N-methyl-D-aspartic acid (NMDA)-receptor-mediated component, lasting hundreds of milliseconds. The time course of the AMPA phase is crucial in the integrative function of neurons, but measuring it accurately is often confounded by cable filtering between the recording electrode and the synapse. We describe a method for recovering the AMPA phase of individual EPSCs by determining the impulse response of the cable filter from single NMDA channel transitions in the slow tails of the same EPSC, then deconvolving the measured AMPA current. Using simulations, we show that filtering of an AMPA conductance transient in a voltage-clamped dendrite behaves in an almost perfectly linear fashion. Expressions are derived for the time course of single channel transitions and the AMPA phase filtered through a voltage-clamped cable or a single exponential filter, using a kinetic model for AMPA receptor activation. Fitting these expressions to experimental records directly estimates the underlying kinetics of the AMPA phase. Example measurements of spontaneous EPSCs in cultured nonpyramidal rat cortical neurons yielded rising time constants of 0.2-0.8 ms, and decay time constants of 1.3-2 ms at 23-25 degrees C.

Animals↗
PubMed2000

Neurotoxic APP C-terminal and beta-amyloid domains colocalize in the nuclei of substantia nigra pars reticulata neurons undergoing delayed degeneration.

Increased amyloid precursor protein (APP) expression and intracellular accumulation of its toxic fragments have been associated with acute neuronal death processes. However, the role of APP fragments in delayed neurodegeneration remains poorly understood. We have characterized the appearance of APP domains in rat substantia nigra pars reticulata (SNpR) neurons targeted for delayed degeneration following neurotoxic striatal lesion. From 4 to 8 days postlesion (dpl) SNpR neurons ipsilateral to the lesion showed marked cytosolic accumulation of full length APP. Moreover, the nuclei of affected neurons also showed intense immunoreactivity (IR) for APP C-terminal and beta-amyloid domains but not for an N-terminal sequence. These data suggested the presence of APP C-terminal fragment. The absence of nuclear IR for a beta1-40 specific antibody supports this conclusion. Ultrastructural analysis of nigral sections from 6 dpl rats using a beta-amyloid domain antibody showed pronounced accumulation of immunogold-silver reaction product in the nuclei of affected SNpR neurons that was absent in control, contralateral SNpR neurons. These findings suggest that intranuclear APP C-terminal fragment may play a role in genomic events contributing to delayed neuron degeneration in the SNpR.

Amyloid beta-Peptides↗
PubMed1998

NMDA receptor subunit NR1-immunoreactivity in the rat pons and brainstem and colocalization with Fos induced by nasal stimulation.

In the present study, we examined the distribution of neurons in the parabrachial nucleus (PB), the Kölliker-Fuse nucleus (KF), the spinal trigeminal nucleus caudalis (Sp5C), the nucleus of the solitary tract (NTS) and the ventrolateral medulla (VLM), which are activated by evoking the nasotrigeminal reflex and which exhibit immunoreactivity for the N-methyl-D-aspartate (NMDA) receptor subunit NR1. By stimulating the nasal mucosa with saline, we induced the expression of the immediate early gene c-fos and combined the immunocytochemical detection of the Fos protein with the detection of the NR1 subunit. Cell counts revealed that nasal stimulation, compared to anesthesia controls, resulted in highly significant increases (p < or = 0.001) of Fos-immunoreactive (-ir) neurons in the midlevel KF, the external lateral PB, and the Sp5C. In the central lateral PB, the rostral ventrolateral medulla including the Bötzinger/pre-Bötzinger complex, and in the ventrolateral and commissural NTS the increases were only moderately significant (p < or = 0.05). With respect to the numbers of NR1-/Fos-ir double-labeled neurons, significant increases were only observed in a subset of these pontomedullary nuclei. Increases were highly significant in the Sp5C (p < or = 0.001) and the midlevel KF (p < or = 0.01) and moderately significant (p < or = 0.05) in the external lateral PB, Bötzinger/pre-Bötzinger complex, and ventrolateral NTS. The present study revealed that nasotrigeminally activated neurons in mandatory and potential relay sites of the nasotrigeminal reflex circuit express the NR1 subunit. This finding strongly suggests that NMDA-type glutamate receptors are involved in the mediation of the nasotrigeminally evoked cardiovascular and respiratory responses.

Animals↗
PubMed2000

Colocalization of leukotriene C synthase and microsomal glutathione S-transferase elucidated by indirect immunofluorescence analysis.

We have previously shown that the two membrane bound enzymes leukotriene C synthase and microsomal glutathione S-transferase interact in vitro and in vivo. Rat basophilic leukemia cells and murine mastocytoma cells, two well-known sources of leukotriene C synthase, both expressed microsomal glutathione S-transferase as determined by Western blot analyses. Several human tissues were found to contain both leukotriene C synthase and microsomal glutathione S-transferase mRNA. These data suggest that the interaction may be physiologically important. To study this further, expression vectors encoding the two enzymes were cotransfected into mammalian cells and the subcellular localization of the enzymes was determined by indirect immunofluorescence using confocal laser scanning microscopy. The results showed that leukotriene C synthase and microsomal glutathione S-transferase were both localized on the nuclear envelope and adjacent parts of the endoplasmic reticulum. Image overlay demonstrated virtually identical localization. We also observed that coexpression substantially reduced the catalytic activity of each enzyme suggesting that a mechanism involving protein-protein interaction may contribute to the regulation of LTC4 production.

Animals↗
PubMed1999

Cloning and expression pattern of EPAS1 in the chicken embryo. Colocalization with tyrosine hydroxylase.

EPAS1 is a hypoxia-inducible transcription factor, highly expressed in vasculature and recently shown to be necessary for catecholamine production during embryogenesis. We report here the cloning and detailed expression pattern of this factor in the chicken embryo. We show that chicken EPAS1 presents an overall identity of 76% with the human sequence and that it is strongly expressed in the blood vessel wall, mostly in endothelial cells, but also in vascular smooth muscle cells. Moreover, we report non-vascular expression sites: liver, kidney, and, quite interestingly, cells of the sympathetic nervous system where EPAS1 is coexpressed with one of its putative target genes, the tyrosine hydroxylase. EPAS1 could therefore represent the link between the vascular system and the sympathetic nervous system, both sensitive to hypoxia.

Amino Acid Sequence↗
PubMed2003

Epinephrine and dopamine colocalization with norepinephrine in various peripheral tissues: guanethidine effects.

Chemical sympathectomy with guanethidine (Gnt) selectively destroys the postganglionic noradrenergic neurons, whereas dopaminergic fibers and nonneural catecholamine-secreting cells are spared. As a result, the relative proportions of norepinephrine (NE), epinephrine (E), and dopamine (DA) in tissues can be differentially affected. This study was done to show the possible differences in the relative amount of catecholamines in some organs and tissues that might indicate the nature of the secretory cells from which they originate. The contents of NE, E, and DA were assessed in rats neonatally treated with Gnt. Gnt-treated rats showed significantly lower levels of NE (P < 0.01) in all tissues except the adrenal gland and paraganglia. Epinephrine was present in all tissues with mean levels below 25 ng/g, with the exception of the adrenal gland (700 microg/gland) and paraganglia (100 ng/g). Only the heart showed lower values in Gnt-treated rats. Mean DA levels were also very high in paraganglia (530 ng/g). In the Gnt-treated rats, DA levels fell practically to zero except in the duodenum, mesentery, and adrenal, whereas there were high levels in the paraganglia, which were significantly different from controls. The results suggest that the three catecholamines are contained mainly in noradrenergic sympathetic fibers of muscle, white adipose tissue, heart, liver, pancreas, and spleen. The duodenum and mesentery may have dopaminergic fibers or E- and DA-containing nonneural cells. Hepatic-vagus paraganglia contain all the catecholamines in relatively high amounts in nonneural cells, and Gnt treatment raises DA levels without affecting the other amines.

Adipose Tissue, Brown↗
PubMed2002

Cell type specific expression of secretory TFF peptides: colocalization with mucins and synthesis in the brain.

The "TFF domain" is an ancient cysteine-rich shuffled module forming the basic unit for the family of secretory TFF peptides (formerly P-domain peptides and trefoil factors). It is also an integral component of mosaic proteins associated with mucous surfaces. Three mammalian TFF peptides are known (i.e., TFF1-TFF3); however, in Xenopus laevis the pattern is more complex (xP1, xP4.1, xP4.2, and xP2). TFF peptides are typical secretory products of a variety of mucin-producing epithelial cells (e.g., the conjunctiva, the salivary glands, the gastrointestinal tract, the respiratory tract, and the uterus). Each TFF peptide shows an unique expression pattern and different mucin-producing cells are characterized by their specific TFF peptide/secretory mucin combinations. TFF peptides have a pivotal role in maintaining the surface integrity of mucous epithelia in vivo. They are typical constituents of mucus gels, they modulate rapid mucosal repair ("restitution") by their motogenic and their cell scattering activity, they have antiapoptotic effects, and they probably modulate inflammatory processes. Pathological expression of TFF peptides occurs as a result of chronic inflammatory diseases or certain tumors. TFF peptides are also found in the central nervous system, at least in mammals. In particular, TFF3 is synthesized from oxytocinergic neurons of the hypothalamus and is released from the posterior pituitary into the bloodstream.

Animals↗