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Background: Lead (Pb) exposure has been associated with a host of pathological conditions in humans. In rodents Pb exposure has been shown to alter the hypothalamic–pituitary–adrenal (HPA) axis function. Objective: We investigated the effects of lead on responses of the HPA axis to a psychosocial laboratory stressor administered to Pb-exposed workers. Methods: Seventy male participants completed the Trier Social Stress Test (TSST). Serum cortisol (CORT) and plasma adrenocorticotropic hormone (ACTH) were assessed in response to and during recovery from the stressor. We measured Pb in blood, a biomarker of recent exposure, and in tibia bone by X-ray fluorescence (XRF), a biomarker of chronic exposure. Results: The TSST induced statistically significant increases in ACTH and CORT in the participants. At baseline, ACTH was not significantly higher (p = 0.052) in participants with higher blood Pb concentration, but CORT was significantly lower in these participants (p = 0.016). Adjusted linear regression models indicated a positive association between blood and bone Pb and the increase in ACTH in response to stress. However, Pb was not strongly associated with changes in CORT in response to stress. Pb was also associated with the ACTH:CORT ratio at baseline and throughout the course of the protocol, suggesting an adrenal hyporesponsiveness in participants with higher Pb concentrations. Conclusion: The altered HPA-axis stress response observed in participants exposed to higher levels of Pb further supports the idea that lead may contribute to a host of biological dysfunctions beyond the classical neurotoxic effects.

Epidemiologic associations between acutely increased cardiorespiratory morbidity and mortality and particulate air pollution are well established, but the effects of acute pollution exposure on human gene expression changes are not well understood.In order to identify potential mechanisms underlying epidemiologic associations between air pollution and morbidity, we explored changes in gene expression in humans following inhalation of fresh diesel exhaust (DE), a model for particulate air pollution.Fourteen ethnically homogeneous (white males), young, healthy subjects underwent 60-min inhalation exposures on 2 separate days with clean filtered air (CA) or freshly generated and diluted DE at a concentration of 300 μg/m(3) PM(2.5). Prior to and 24 h following each session, whole blood was sampled and fractionated for peripheral blood mononuclear cell (PBMC) isolation, RNA extraction, and generation of cDNA, followed by hybridization with Agilent Whole Human Genome (4X44K) arrays.Oxidative stress and the ubiquitin proteasome pathway, as well as the coagulation system, were among hypothesized pathways identified by analysis of differentially expressed genes. Nine genes from these pathways were validated using real-time polymerase chain reaction (PCR) to compare fold change in expression between DE exposed and CA days. Quantitative gene fold changes generated by real-time PCR were directionally consistent with the fold changes from the microarray analysis.Changes in gene expression connected with key oxidative stress, protein degradation, and coagulation pathways are likely to underlie observed physiologic and clinical outcomes and suggest specific avenues and sensitive time points for further physiologic exploration.

Ovarian granulosa cells play a central role in steroidogenesis, which is critical for female reproduction. Follicle-stimulating hormone (FSH) promotes cyclic adenosine monophosphate (cAMP)-mediated signaling to regulate granulosa cell steroidogenesis. We have shown previously that 2,2-bis-(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE) inhibits FSH- and dibutyryl cAMP-stimulated steroidogenesis and affects the messenger RNA levels of steroidogenic pathway enzymes in rat granulosa cells. However, HPTE showed a differential effect in FSH- and cAMP-stimulated cells in that HPTE more completely blocked FSH- when compared to cAMP-driven steroidogenesis. The objective of this study was to analyze the effects of HPTE on global gene expression profiles in untreated granulosa cells and those challenged with FSH or cAMP. Granulosa cells from immature rats were cultured with 0, 1, 5, or 10 microM HPTE in the presence or absence of either 3 ng FSH/ml or 1mM cAMP for 48 h. Total RNA was isolated for real-time quantitative PCR and microarray analysis using the GeneChip Rat Genome 230 2.0 and ArrayAssist Microarray Suite. An investigation of changes in gene expression across all HPTE treatments showed that HPTE altered more genes in FSH- (approximately 670 genes) than in cAMP-stimulated cells (approximately 366 genes). Analysis confirmed that HPTE more effectively inhibited FSH- than cAMP-induced steroid pathway gene expression and steroidogenesis. Furthermore, expression patterns of novel genes regulating signal transduction, transport, cell cycle, adhesion, differentiation, motility and growth, apoptosis, development, and metabolism were all altered by HPTE. This study further established that HPTE exerts differential effects within the granulosa cell steroidogenic pathway and revealed that these effects include broader changes in gene expression.

Cerebral angiopathy contributes to cognitive decline and dementia in Alzheimer's disease (AD) through cerebral blood flow (CBF) reductions and dysregulation. We report vascular smooth muscle cells (VSMC) in small pial and intracerebral arteries, which are critical for CBF regulation, express in AD high levels of serum response factor (SRF) and myocardin (MYOCD), two interacting transcription factors that orchestrate a VSMC-differentiated phenotype. Consistent with this finding, AD VSMC overexpressed several SRF-MYOCD-regulated contractile proteins and exhibited a hypercontractile phenotype. MYOCD overexpression in control human cerebral VSMC induced an AD-like hypercontractile phenotype and diminished both endothelial-dependent and -independent relaxation in the mouse aorta ex vivo . In contrast, silencing SRF normalized contractile protein content and reversed a hypercontractile phenotype in AD VSMC. MYOCD in vivo gene transfer to mouse pial arteries increased contractile protein content and diminished CBF responses produced by brain activation in wild-type mice and in two AD models, the Dutch/Iowa/Swedish triple mutant human amyloid β-peptide (Aβ)-precursor protein ( APP )- expressing mice and APPsw +/− mice. Silencing Srf had the opposite effect. Expression of SRF did not change in VSMC subjected to Alzheimer's neurotoxin, Aβ. Thus, SRF-MYOCD overexpression in small cerebral arteries appears to initiate independently of Aβ a pathogenic pathway mediating arterial hypercontractility and CBF dysregulation, which are associated with Alzheimer's dementia.

In neurons, a variety of extracellular stimuli are capable of inducing transcriptional events that underlie complex processes ranging from learning to disease. The mechanisms linking these long-lasting cellular modifications to behavior remain to be established. Here, we show by microarray analysis that hippocampal activation of glucagon-like peptide-1 receptor (GLP-1R), which is associated with improved learning and neuroprotection, results in suppression of the transcription factor DBP (albumin D-site-binding protein). Recombinant adeno-associated virus (rAAV) based gene expression of DBP in the hippocampus of adult rats caused upregulation of mRNAs encoding constituents of the molecular clock, and the DBP target gene, pyridoxal kinase. Behaviorally, DBP over expression inhibited spatial learning but not memory, and enhanced susceptibility to kainate-induced seizures. This phenotype was paralleled by the activation of MAP kinase in dendritic regions of hippocampal neurons in vivo. These data suggest that DBP may represent an important transcriptional link between GLP-1R activation and neuroplasticity in the hippocampus.

Neurovascular dysfunction substantially contributes to Alzheimer disease. Here, we show that transcriptional profiling of human brain endothelial cells (BECs) defines a subset of genes whose expression is age-independent but is considerably altered in Alzheimer disease, including the homeobox gene MEOX2 (also known as GAX), a regulator of vascular differentiation, whose expression is low in Alzheimer disease. By using viral-mediated MEOX2 gene silencing and transfer, we show that restoring expression of the protein it encodes, GAX, in BECs from individuals with Alzheimer disease stimulates angiogenesis, transcriptionally suppresses AFX1 forkhead transcription factor-mediated apoptosis and increases the levels of a major amyloid-beta peptide (Abeta) clearance receptor, the low-density lipoprotein receptor-related protein 1 (LRP), at the blood-brain barrier. In mice, deletion of Meox2 (also known as Gax) results in reductions in brain capillary density and resting cerebral blood flow, loss of the angiogenic response to hypoxia in the brain and an impaired Abeta efflux from brain caused by reduced LRP levels. The link of MEOX2 to neurovascular dysfunction in Alzheimer disease provides new mechanistic and therapeutic insights into this illness.

Background Autism is a severe neurodevelopmental disorder with genetic and environmental etiologies. Recent genetic linkage studies implicate Reelin glycoprotein in causation of autism. To further investigate these studies, brain levels of Reelin protein and mRNA and mRNAs for VLDLR, Dab-1, and GSK3 were investigated. Methods Postmortem superior frontal, parietal, and cerebellar cortices of age, gender, and postmortem interval-matched autistic and control subjects were subjected to SDS-PAGE and Western blotting of Reelin protein. Quantitative reverse transcriptase polymerase chain reaction analysis of Reelin, VLDL-R, Dab-1, and GSK3 mRNA species in superior frontal and cerebellar cortices of autistic and control subjects were also performed. Results Reelin 410, 330, and 180 kDa/β-actin values were reduced significantly in frontal and cerebellar, and nonsignificantly in parietal, areas of autistic brains versus control subjects, respectively. The mRNAs for Reln and Dab-1 were reduced significantly whereas the mRNA for Reln receptor VLDLR was elevated significantly in superior frontal and cerebellar areas of autistic brains versus control brains, respectively. Conclusions Reductions in Reelin protein and mRNA and Dab 1 mRNA and elevations in Reln receptor VLDLR mRNA demonstrate impairments in the Reelin signaling system in autism, accounting for some of the brain structural and cognitive deficits observed in the disorder.

The role of astrocytes in HIV-1 associated dementia (HAD) is not well understood. HIV-1 binds efficiently to astrocytes but infects only a small fraction of the cells in vitro and in vivo. To gain insight into the biology of HIV-1-expressing astrocytes, we productively infected human fetal astrocytes with pseudotyped HIV-1 and employed Affymetrix oligonucleotide microarrays to determine global changes in cellular gene expression at the peak of virus production. With a twofold change as a cutoff, HIV-1 increased transcription of 266 genes in astrocytes and suppressed expression of 468. The functions of highly expressed genes included interferon-mediated antiviral responses (OAS1, IFIT1), intercellular contacts (SH3, glia-derived nexin), cell homing/adhesion (matrix metalloproteinases), and cell–cell signaling (neuropilin 1 and 2). Surprisingly, genes involved in innate immune responses of astrocytes were largely unaffected. The single most significant effect of HIV-1, however, was down-modulation of at least 55 genes involved in control of cell cycle, DNA replication, and cell proliferation, which were overrepresented in these categories with probability scores of 10 −10 –10 −26 . Our data suggest that HIV-1 expression in astrocytes profoundly alters host cell biology, with potential consequences for the physiological function of astrocytes during HIV-1 infection in the brain.

DNA microarray analysis has been used to investigate relative changes in the level of gene expression in the CNS, including changes that are associated with disease, injury, psychiatric disorders, drug exposure or withdrawal, and memory formation. We have used oligonucleotide microarrays to identify hypothalamic genes that respond to nutritional manipulation. In addition to commonly used microarray analysis based on criteria such as fold-regulation, we have also found that simply carrying out multiple t tests then sorting by P value constitutes a highly reliable method to detect true regulation, as assessed by real-time polymerase chain reaction (PCR), even for relatively low abundance genes or relatively low magnitude of regulation. Such analyses directly suggested novel mechanisms that mediate effects of nutritional state on neuroendocrine function and are being used to identify regulated gene products that may elucidate the metabolic pathology of obese ob/ob, lean Vgf-/Vgf-, and other models with profound metabolic impairments.

Bacterial communication via quorum sensing (QS) has been reported to be important in the production of virulence factors, antibiotic sensitivity, and biofilm development. Two QS systems, known as the las and rhl systems, have been identified previously in the opportunistic pathogen Pseudomonas aeruginosa . High-density oligonucleotide microarrays for the P. aeruginosa PAO1 genome were used to investigate global gene expression patterns modulated by QS regulons. In the initial experiments we focused on identifying las and/or rhl QS-regulated genes using a QS signal generation-deficient mutant (PAO-JP2) that was cultured with and without added exogenous autoinducers [ N -(3-oxododecanoyl) homoserine lactone and N -butyryl homoserine lactone]. Conservatively, 616 genes showed statistically significant differential expression ( P ≤ 0.05) in response to the exogenous autoinducers and were classified as QS regulated. A total of 244 genes were identified as being QS regulated at the mid-logarithmic phase, and 450 genes were identified as being QS regulated at the early stationary phase. Most of the previously reported QS-promoted genes were confirmed, and a large number of additional QS-promoted genes were identified. Importantly, 222 genes were identified as being QS repressed. Environmental factors, such as medium composition and oxygen availability, eliminated detection of transcripts of many genes that were identified as being QS regulated.

Loss of synapses correlates with cognitive decline in Alzheimer's disease (AD). However, molecular mechanisms underlying the synaptic dysfunction and loss are not well understood. In this study, microarray analysis of brain tissues from five AD cases revealed a reduced expression of a group of related genes, all of which are involved in synaptic vesicle (SV) trafficking. By contrast, several synaptic genes with functions other than vesicle trafficking remained unchanged. Quantitative RT-PCR confirmed and expanded the microarray findings. Furthermore, immunoblotting showed that the protein level of at least one of these gene products, dynamin I, correlated with its reduced transcript. Immunhistochemical analysis exhibited an altered distribution of dynamin I immunolabeling in AD neurons. Microarray analysis of transgenic mice with mutated amyloid precursor protein showed that although the transcript levels for some of the SV trafficking-related genes are also decreased, the change in dynamin did not replicate the AD pattern. The results suggest a link among SV vesicle-trafficking pathways, synaptic malfunction, and AD pathogenesis.

Gene transfer vectors based on lentiviruses can transduce terminally differentiated cells in the brain; however, their ability to reverse established behavioral deficits in animal models of neurodegeneration has not previously been tested. When recombinant feline immunodeficiency virus (FIV)-based vectors expressing beta-glucuronidase were unilaterally injected into the striatum of adult beta-glucuronidase deficient [mucopolysaccharidosis type VII (MPS VII)] mice, an animal model of lysosomal storage disease, there was bihemispheric correction of the characteristic cellular pathology. Moreover, after the injection of FIV-based vectors expressing beta-glucuronidase into brains of beta-glucuronidase-deficient mice with established impairments in spatial learning and memory, there was dramatic recovery of behavioral function. Cognitive improvement resulting from expression of beta-glucuronidase was associated with alteration in expression of genes associated with neuronal plasticity. These data suggest that enzyme replacement to the MPS VII central nervous system goes beyond restoration of beta-glucuronidase activity in the lysosome, and imparts improvements in plasticity and spatial learning.

Vascular endothelial growth factor (VEGF) is a potent neovascular inducer. Gene therapeutic delivery of a plasmid DNA encoding VEGF has been shown to impart collateral vessel development in animal models of hindlimb ischemia. Constitutive, long-lived expression of VEGF through gene transfer, however, may result in hypervascularization and/or leaky blood vessels. To that end, the introduction of regulated VEGF gene transfer technology may provide a safer and more controlled therapy for ischemic tissues. We developed a glucocorticoid-regulated plasmid vector (pNGVL-hAP/GRE(5)-vegf-pA) for modulating VEGF gene expression. This plasmid possessed five tandem repeats of the glucocorticoid-responsive element and adenovirus major-late promoter driving the expression of the VEGF(165) cDNA. Intramuscular delivery of this plasmid to mice, and subsequent treatment with the synthetic glucocorticoid dexamethasone (DEX), led to greatly enhanced VEGF expression. Similar delivery to the gracillis muscle of New Zealand white rabbits that had undergone ligation of their femoral artery to induce ischemia exhibited increased VEGF expression and collateral vessel development only in the presence of DEX. Additionally, reintroduction of DEX at a time point during which initial VEGF transgene levels had subsided resulted in a vigorous reinduction of VEGF transgene expression. This new iteration of VEGF gene delivery provides for fine-tuned angiogenic factor-based therapy for tissues requiring neovascularization.

A microarray study of the effect of senescence in mice on gene expression in muscle has been published recently. The present analysis was done to evaluate the extent to which the age-related differences in gene expression in murine muscle are also evident in human muscle. RNA extracted from muscle of young (21–24 yr) and old men (66–77 yr) was studied both by serial analysis of gene expression (SAGE) and by oligonucleotide microarrays. SAGE tags were detected for 61 genes homologous to genes reported to be differentially expressed in young and old murine muscle. The microarray had probe sets for 70 homologous genes. For 17 genes, there was evidence for a similar age-related change in expression in muscles of mice and men. For 32 other genes, there was evidence that the effect of age on the level of expression is not the same in mice and men. There was no evidence that older human muscle has increased expression of the stress response genes that are increased in old murine muscle.

Spatial learning requires the integrity of the nerve growth factor (NGF)-responsive septohippocampal pathway. Loss of a single NGF allele at the mouse NGF locus (heterozygous null, ngf(+/-)) reduces septohippocampal NGF levels and NGF-regulated cholinergic neurotransmitter enzymes and results in spatial learning deficits in adult animals. A herpes simplex virus (HSV) amplicon vector was utilized to locally deliver NGF to the hippocampus of mice heterozygous and wild type (ngf(+/+)) at the NGF gene locus. NGF gene transfer produced transient increases in NGF protein levels and choline acetyltransferase activity in both ngf(+/-) and ngf(+/+) mice. However, spatial learning capability was improved only in ngf(+/-) mice. In aggregate, these findings suggest that amplicon-directed expression of NGF in subjects with baseline septohippocampal dysfunction can correct spatial learning deficits.

Molecular genetic manipulation of the mouse offers the possibility of elucidating the function of individual gene products in neural systems underlying learning and memory. Many extant learning paradigms for mice rely on negative reinforcement, involve simple problems that are relatively rapidly acquired and thus preclude time-course assessment, and may impose the need to undertake additional experiments to determine the extent to which noncognitive behaviors influence the measures of learning. To overcome such limitations, a multiple schedule of repeated acquisition and performance was behaviorally engineered to assess learning vs rote performance within-behavioral test session and within-subject utilizing an apparatus modified from the rat (the repeated acquisition and performance chamber; RAPC). The multiple schedule required mice to learn a new sequence of door openings leading to saccharin availability in the learning component during each session, while the sequence of door openings for the performance component remained constant across sessions. The learning and performance components alternated over the course of each test session, with different auditory stimuli signaling which component was currently in effect. To validate this paradigm, learning vs performance was evaluated in two inbred strains of mice: C57BL/6J and 129/SvJ. The hippocampal dependence of this measure was examined in lesioned C57BL/6J mice. Both strains exhibited longer latencies and higher errors in the learning compared to the performance component and evidenced declines in both measures across the trials of each session, consistent with an acquisition phenomenon. These same measures showed little or no evidence of change in the performance component. Whereas three trials per session were utilized with C57BL/65 mice in each component, behavior of 129/SvJ mice could only be sustained for two trials per component per session, demonstrating differences in testing capabilities between these two strains under these experimental conditions and thus precluding the ability to make systematic strain comparisons of learning capabilities. Hippocampal lesions in C57BL/6J mice resulted in substantially longer latencies and increased errors in the learning but not the performance component, demonstrating the importance of this region to spatial learning as measured in the RAPC. In aggregate, this positive reinforcement-based operant paradigm to evaluate murine spatial learning detects strain differences and hippocampal dependence and permits explicit differentiation of the impact of noncognitive contributions to learning measures on a within-subject, within-session basis.

HIV-1 infection of the brain results in chronic inflammation, contributing to the neuropathogenesis of HIV-1 associated neurologic disease. HIV-1-infected mononuclear phagocytes (MP) present in inflammatory infiltrates produce neurotoxins that mediate inflammation, dysfunction, and neuronal apoptosis. Neurologic disease is correlated with the relative number of MP in and around inflammatory infiltrates and not viral burden. It is unclear whether these cells also play a neuroprotective role. We show that the chemokine, fractalkine (FKN), is markedly up-regulated in neurons and neuropil in brain tissue from pediatric patients with HIV-1 encephalitis (HIVE) compared with those without HIVE, or that were HIV-1 seronegative. FKN receptors are expressed on both neurons and microglia in patients with HIVE. These receptors are localized to cytoplasmic structures which are characterized by a vesicular appearance in neurons which may be in cell-to-cell contact with MPs. FKN colocalizes with glutamate in these neurons. Similar findings are observed in brain tissue from an adult patient with HIVE. FKN is able to potently induce the migration of primary human monocytes across an endothelial cell/primary human fetal astrocyte trans-well bilayer, and is neuroprotective to cultured neurons when coadministered with either the HIV-1 neurotoxin platelet activating factor (PAF) or the regulatory HIV-1 gene product Tat. Thus focal inflammation in brain tissue with HIVE may up-regulate neuronal FKN levels, which in turn may be a neuroimmune modulator recruiting peripheral macrophages into the brain, and in a paracrine fashion protecting glutamatergic neurons.

Western blots using an antibody which recognizes the orphanin FQ/nociceptin (OFQ/N) receptor reveals a band at approximately 69 kD in several cell lines, including the Raji human B cell lymphoma cell line. RT-PCR confirms the presence of this receptor in the Raji cells. Binding studies revealed a high affinity [(125)I][Tyr(14)]OFQ/N site in the Raji cells. The affinity of [(125)I][Tyr(14)]OFQ/N in the Raji cells (K(D) 68.4 pM) was similar to that in the transfected receptor (K(D) 36.7 pM). Its selectivity profile also was quite similar. OFQ/N competed binding quite potently (K(i) 65 pM), as did [Tyr(14)]OFQ/N (K(i) 33 pM). Traditional opioids displayed no appreciable affinity for the binding at any concentration examined, with the exception of naloxone benzoylhydrazone, which had only a very modest affinity. The receptors in the Raji cells were functionally active. OFQ/N inhibited forskolin-stimulated cyclase by 72% with an IC(50) value of approximately 1 nM.

The herbicide paraquat, bearing structural similarity to the known dopaminergic neurotoxicant MPTP, has been suggested as a potential etiologic factor in Parkinson's disease. Consideration of paraquat as a candidate neurotoxicant requires demonstration that systemic delivery produces substantia nigra dopaminergic neuron loss and the attendant neurobehavioral syndrome reflecting depletion of dopamine terminals within the striatum. To address these issues paraquat was administered systemically into adult C57 bl/6 mice, ambulatory behavior monitored, substantia nigra dopamine neuron number and striatal dopamine terminal density quantified. The data indicate that paraquat like MPTP elicits a dose-dependent decrease in substantia nigra dopaminergic neurons assessed by a Fluoro-gold prelabeling method, a decline in striatal dopamine nerve terminal density assessed by measurement of tyrosine hydroxylase immunoreactivity; and neurobehavioral syndrome characterized by reduced ambulatory activity. Taken together, these data suggest that systemically absorbed paraquat crosses the blood-brain barrier to cause destruction of dopamine neurons in the substantia nigra, consequent reduction of dopaminergic innervation of the striatum and a neurobehavioral syndrome similar to the well characterized and bona fide dopaminergic toxin MPTP.

The study of herpes virus biology has produced two vector delivery strategies which exploit the highly evolved neuronal tropism and life cycle regulation exhibited by this class of viruses. Amplicon and recombinant herpes simplex virus systems show promise for use in gene transfer to the nervous system and although neither vector has been used in clinical trials to date, their application to gene delivery and perturbation of neuronal physiology have been well established. We will review the properties of the herpes amplicon system, and demonstrate its utility in neuroscience applications.

Naloxone benzoylhydrazone (NalBzoH) has proved a valuable tool in the investigation of opioid receptor subtypes. In the present study, we have examined a series of derivatives of NalBzoH in which substitutions have been made on the benzoyl ring. Overall, we see dramatic effects on the binding affinities of derivatives against the various opioid receptor subtypes. Although the range of affinities against the mu receptors is quite modest, ranges of the others vary almost 30-fold for kappa 3, 50-fold for kappa 1 and 100-fold for delta and kappa 2 binding. Few substituted derivatives display greater affinity than NalBzoH for any of the receptors, except for delta sites where several derivatives have affinities almost tenfold greater than NalBzoH. Along with the wide variations in affinity, the compounds also appear to exhibited widely divergent activities in traditional bioassays.

To help characterize kappa3 receptors and establish their relationship to traditional mu and delta receptors, we have generated a kappa3-selective monoclonal antibody. Monoclonal antibodies were raised against BE(2)-C cells, a human neuroblastoma cell line containing mu, kappa3, and delta opioid receptors. Of the 5,000 hybridoma cell lines screened, approximately 2,000 hybridomas tested positive against BE(2)-C membranes by ELISA, but only 98 of these were negative against a different neuroblastoma cell line lacking opioid receptors. Supernatants from one hybridoma, 8D8, inhibited up to 90% of 3H-NalBzoH (kappa3) binding without affecting 3H-DAMGO (mu) or 3H-naltrindole (delta) binding in BE(2)-C membranes. The selectivity of the antibody was further demonstrated by its blockade of the inhibition of cAMP accumulation in BE(2)-C cells by the kappa3 agonist NalBzoH but not the mu agonist morphine. Monoclonal antibody 8D8 (mAb8D8) also recognizes kappa3 receptors from mouse, rat, and calf brain. Administered intracerebroventricularly, mAb8D8 blocked kappa3 but not morphine (mu) analgesia in vivo. On Western blots, mAb8D8 recognized a protein with a molecular mass of approximately 70 kilodaltons in BE(2)-C. These studies demonstrate the selectivity of mAb8D8 for kappa3 receptors and provide additional support for the existence of this unique opioid receptor subtype.

Accumulating evidence suggests that urokinase plasminogen activator (uPA) is involved in vascular remodeling and lumen stenosis after angioplasty and stenting. We have shown previously that increased uPA expression greatly promotes neointima formation and inward arterial remodeling after balloon injury. To evaluate the role of inflammation in early mechanisms responsible for inward arterial remodeling induced by uPA and elucidate the mechanisms of remodeling, we characterized changes in the expression profiles of 8,799 genes in injured rat carotid arteries 1 and 4 days after recombinant uPA treatment compared to vehicle. We used a standard model of the balloon catheter injury of the rat carotid followed by periadventitial application to the injured vessel of either uPA dissolved in Pluronic gel, or plain gel. Vessels were harvested and analyzed by immunohistochemistry, morphometry, microarray gene expression profiling and quantitative RT-PCR. Periadventitial application of uPA significantly reduced lumen size and vessel area encompassed by the external elastic lamina at both 1 and 4 days after treatment. Inflammatory cells accumulated in the arterial adventitia at both 1 and 4 days after uPA treatment. On the 4th day, increases in the areas and arterial cell numbers of all arterial layers were found. Among 79 differentially expressed known genes 1 day after uPA application, 12 proinflammatory genes, including TNF-α and TACE, and 15 genes related to mitochondrial metabolism and oxidative stress regulation were identified. Four days after injury in uPA-treated arteries, 3 proinflammatory and 2 oxidation-related genes were differentially expressed. We conclude that uPA likely promotes inward arterial remodeling by regulating oxidative stress and inflammation after arterial injury.

Microarrays have revolutionized many areas of biology due to our technical ability to quantify tens of thousands of transcripts within a single experiment. However, there are still many areas that cannot benefit from this technology due to the amount of biological material needed for microarray analysis. In response to this demand, chemistries have been developed that boast the capability of generating targets from nanogram amounts of total RnA, reflecting minimal amounts of biological material, on the order of several hundred or thousand cells. Herein, we describe the evaluation of four chemistries for RnA amplification in terms of reproducibility, sensitivity, accuracy, and comparability to results from a single round of T7 amplification. No evidence for false-positive measurements of differential expression was observed. In contrast, clear differences between chemistries in sensitivity and accuracy were detected. PCR validation showed an interaction of probe sequence on the array and target labeling chemistry, resulting in a chemistry-dependent probe set sensitivity varying over an order of magnitude.

The aryl-hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates the toxicity of certain halogenated aromatic hydrocarbons including 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD). These compounds are potent developmental toxicants that can alter gene expression and disrupt processes of proliferation and differentiation. It has not yet been determined which tissues during development are most sensitive to these compounds, nor which genes are directly associated with the toxicities. We developed a transgenic (TG) mouse model to delineate the temporal and spatial context of transcriptionally active AhR by utilizing a dioxin responsive element-linked LacZ reporter system. The present study focuses on the pattern of TCDD-induced transgene expression localized to the footpad and digits of the paws between gestational days (GD) 13 and 18. Paw morphology was evaluated at several developmental stages following TCDD exposure. Gene expression profiles acquired by microarray technology were evaluated in the paws of fetuses exposed at GD 14.5. The results showed that TCDD exposure in utero induced LacZ expression in the developing paws. This expression appeared to be localized to the mesenchymal cell layer. Gross morphological changes were not observed in the paws prior to or after birth following TCDD exposure in utero. However, significant alterations in gene expression profiles in the developing paws were observed at 24 h following TCDD exposure in utero. These results indicate that the developing paw is a target tissue of TCDD in terms of altered gene expression, further validating the use of this AhR responsive reporter gene TG mouse model in studying AhR ligand-mediated responsiveness. However, the linkage of these changes to detectable biological outcomes in the paw remains unclear.

Over the past several years, microarray technology has evolved into a critical component of any discovery-based program. Since 1999, the Association of Biomolecular Resource Facilities (ABRF) Microarray Research Group (MARG) has conducted biennial surveys designed to generate a profile of microarray service laboratories and, more importantly, an overview of technology development and implementation. Survey questions addressed instrumentation, protocols, staffing, funding, and work flow in a microarray facility. Presented herein are the results of the MARG 2005 survey; where possible, trends in the field are discussed and compared to data collected from previous surveys.

Understanding how cells withstand a depletion of intracellular water is relevant to the study of longevity, aging, and quiescence because one consequence of air-drying is metabolic arrest. After removal of medium, HEK293 spheroids with intracellular water content of approximately 65% survived partial vacuum, with antistatic control, for weeks in the dark at 25 degrees C. In contrast, only a limited exposure of monolayers to air was lethal; the mitochondrion being a target of this stress. The pathways activated during the long-term arrest and recovery of spheroids depended on both NF-kappaB signaling and sustained JNK activation. A cyclical cascade, presumably originating from an intercellular stress signal, led to endogenous cytokine production (TNF-alpha, IL-1b, and IL-8) and propagation of the cellular stress signal through the co-activation of NF-kappaB and JNK. Increased levels of downstream pathway signaling members, specifically Gadd45beta, c-jun, and ATF3 were observed, as was activation of c-jun (phosphorylation). Activation of these pathways permit cells to survive long-term storage and recovery because chemical inhibition of both NF-kappaB nuclear translocation and JNK phosphorylation led to cell death. The capacity of an immortalized cell to enter, and then exit, a state of long-term quiescence, without genetic or chemical intervention, has implications for the study of cell transformation. In addition, the ability to monitor the relevant signaling pathways at endogenous levels, from effector to transcriptional regulator, emphasizes the utility of multicellular aggregate models in delineating stress response pathways.

APOBEC3G/CEM15 (hA3G) is a novel host factor that confers resistance to lentiviral infection under experimental conditions. Human immunodeficiency virus (HIV) type 1, however, produces viral infectivity factor (Vif) that targets hA3G for proteolysis, thereby escaping this defense system. To examine hA3G's contribution to the protection against HIV disease progression in humans, we quantified hA3G mRNA levels in peripheral blood mononuclear cells from 6 HIV-uninfected and 25 HIV-infected subjects; the latter group included 8 long-term nonprogressors (LTNPs) and 17 progressors. None of the HIV-infected subjects were receiving antiretroviral therapy. We found a striking inverse correlation between hA3G mRNA levels and HIV viral loads ( P ≤ 0.00009) and a highly significant positive correlation between hA3G mRNA levels and CD4 cell counts ( P ≤ 0.00012) in these patients. Furthermore, we discovered that the order of hA3G mRNA levels is LTNPs > HIV-uninfected subjects > progressors.

Schizophrenia and autism are neurodevelopmental disorders with genetic and environmental etiologies. Prenatal viral infection has been associated with both disorders. We investigated the effects of prenatal viral infection on gene regulation in offspring of Balb-c mice using microarray technology. The results showed significant upregulation of 21 genes and downregulation of 18 genes in the affected neonatal brain homogenates spanning gene families affecting cell structure and function, namely, cytosolic chaperone system, HSC70, Bicaudal D, aquaporin 4, carbonic anhydrase 3, glycine receptor, norepinephrine transporter, and myelin basic protein. We also verified the results using QPCR measurements of selected mRNA species. These results show for the first time that prenatal human influenza viral infection on day 9 of pregnancy leads to alterations in a subset of genes in brains of exposed offspring, potentially leading to permanent changes in brain structure and function.

Whereas Parkinson's disease is a neurodegenerative disorder that typically onsets after 60 years of age, the possibility that it could result from insults sustained during development has been proposed. Experimental evidence based on the combined paraquat + maneb model of the Parkinson's disease (PD) phenotype summarized here provides support for such an assertion. Postnatal exposures of mice to these pesticides led not only to a permanent and selective loss of dopaminergic neurons in the substantia nigra pars compacta but also enhanced the impact of these pesticides administered during adulthood relative to developmental only or adult only treatment. Exposure to maneb alone during gestation resulted in a dramatic response to paraquat in adulthood, including notable reductions in levels of dopamine and metabolites and a loss of nigral dopamine (DA) neurons, despite the fact that paraquat does not share structural similarity to or mechanisms of action with maneb. Collectively, these studies provide developmental environmental models of the PD phenotype. In addition, they demonstrate the fact that silent neurotoxicity produced by developmental insults can be unmasked by challenges later during life as well as the potential for cumulative neurotoxicity over the life span.

The mechanisms of neuronal differentiation in PC12 cells are still not completely understood. Here, we report that the tumor suppressor PTEN has a profound effect on differentiation by affecting several pathways involved in nerve growth factor (NGF) signaling. When overexpressed in PC12 cells, PTEN (phosphatase and tensin homologue deleted on chromosome ten) blocked neurite outgrowth induced by NGF. In addition, these cells failed to demonstrate the transient mitogenic response to NGF, as well as subsequent growth arrest. Consistent with these observations was a finding that PTEN significantly inhibits NGF-mediated activation of the members of mitogen-activated protein kinase kinase (MEK)/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways, crucial for these processes. While exploring possible mechanisms of PTEN effects on NGF signaling, we discovered a significant down-regulation of both high-affinity (TrkA) and low-affinity (p75) NGF receptors in PTEN-overexpressing clones. Subsequent microarray analysis of several independent clonal isolates revealed a myriad of neuronal genes to be affected by PTEN. All of these changes were validated by quantitative PCR. Of particular interest were the genes for the key enzymes of the dopamine synthesis pathway, receptors for different neurotransmitters, and neuron-specific cytoskeleton proteins, among others. Some, but not all effects could be reproduced by pharmacological inhibitors of PI3K and/or MAPK, suggesting that PTEN may influence some genes by mechanisms independent of these signaling pathways. Our findings may shed new light on the role of this tumor suppressor during normal brain development and suggest a previously uncharacterized mechanism of PTEN action in neuron-like cells.

Neurodegeneration and dementia caused by human immunodeficiency virus type 1 (HIV-1) infection of the brain are common complications of acquired immunodeficiency syndrome (AIDS). Introduction of highly active antiretroviral therapy (HAART) reduced the incidence of HIV-1-associated dementia, but so far had no effect on the high frequency of milder neurological disorders caused by HIV-1. This indicates that some neuropathogenic processes persist during limited HIV-1 replication in the central nervous system (CNS). The authors are evaluating the hypothesis that interaction of HIV-1 with astrocytes, which bind HIV-1 but support limited productive HIV-1 infection, may contribute to these processes by disrupting astrocyte functions that are important for neuronal activity or survival. Using laser-capture microdissection on brain tissue samples from HIV-1-infected individuals, we found that HIV-1 DNA can be detected in up to 1% of cortical and basal ganglia astrocytes, thus confirming HIV-1 infection in astrocytes from symptomatic patients. Using rapid subtraction hybridization, the authors cloned and identified 25 messenger RNAs in primary human fetal astrocytes either up-regulated or down-regulated by native HIV-1 infection or exposure to gp120 in vitro. Extending this approach to gene microarray analysis using Affymetrix U133A/B gene chips, the authors determined that HIV-1 alters globally and significantly the overall program of gene expression in astrocytes, including changes in transcripts coding for cytokines, G-coupled protein receptors, transcription factors, and others. Focusing on a specific astrocyte function relevant to neuropathogenesis, the authors showed that exposure of astrocytes to HIV-1 or gp120 in vitro impairs the ability of the cells to transport l-glutamate and the authors related this defect to transcriptional inhibition of the EAAT2 glutamate transporter gene. These findings define new pathways through which HIV-1 may contribute to neuropathogenesis under conditions of limited virus replication in the brain.

Gene expression profiling may provide leads for investigations of the molecular basis of functional declines associated with aging. In this study, high-density oligonucleotide arrays were used to probe the patterns of gene expression in skeletal muscle of seven young women (20-29 years old) and eight healthy older women (65-71 years old). The older subjects had reduced muscle mass, strength, and peak oxygen consumption relative to young women. There were approximately 1000 probe sets that suggested differential gene expression in younger and older muscle according to statistical criteria. The most highly overexpressed genes (>3-fold) in older muscle were p21 (cyclin-dependent kinase inhibitor 1A), which might reflect increased DNA damage, perinatal myosin heavy chain, which might reflect increased muscle fiber regeneration, and tomoregulin, which does not have a defined function in muscle. More than 40 genes encoding proteins that bind to pre-mRNAs or mRNAs were expressed at higher levels in older muscle. More than 100 genes involved in energy metabolism were expressed at lower levels in older muscle. In general, these results support previous observations on the differences in gene expression profiles between younger and older men.

Studies of gene expression related to aging of skeletal muscle have included few subjects or a limited number of genes. We conducted the present study to produce more comprehensive gene expression profiles. RNA was extracted from vastus lateralis biopsies obtained from healthy young (21-27 yr old, n = 8) and older men (67-75 yr old, n = 8) and was analyzed with high-density oligonucleotide arrays. Of the approximately 44,000 probe sets on the arrays, approximately 18,000 yielded adequate signals for statistical analysis. There were approximately 700 probe sets for which t-tests or rank sum tests indicated a difference (Por= 0.01) in mean expression between young and old and for which the estimated false discovery rate was10%. Most of these differences were less than 1.5-fold in magnitude. Genes that encode proteins involved in energy metabolism and mitochondrial protein synthesis were expressed at a lower level in older muscle. Genes encoding metallothioneins, high-mobility-group proteins, heterogeneous nuclear ribonucleoproteins and other RNA binding/processing proteins, and components of the ubiquitin-proteasome proteolytic pathway were expressed at higher levels in older muscle. Expression of numerous genes involved with stress responses, hormone/cytokine/growth factor signaling, control of the cell cycle and apoptosis, and transcriptional regulation appeared to be affected by aging. More transcripts were detected in older muscle, suggesting dedifferentiation, an increased number of splice variants, or increased cellular heterogeneity. We conclude that in human skeletal muscle the expression of many genes tends to increase or decrease between the third and seventh decades. The changes are modest when averaged over all of the cells in the tissue.

Juvenile neuronal ceroid lipofuscinosis (JNCL or Batten Disease) is the most common progressive neurodegenerative disorder of childhood. The disease is inherited in an autosomal recessive manner and is the result of mutations in the CLN3 gene. One brain region severely affected in Batten disease is the cerebellum. Using a mouse model for Batten disease which shares pathological similarities to the disease in humans we have used oligonucleotide arrays to profile approximately 19,000 mRNAs in the cerebellum. We have identified reproducible changes of twofold or more in the expression of 756 gene products in the cerebellum of 10-week-old Cln3-knockout mice as compared to wild-type controls. We have subsequently divided these genes with altered expression into 14 functional categories. We report a significant alteration in expression of genes associated with neurotransmission, neuronal cell structure and development, immune response and inflammation, and lipid metabolism. An apparent shift in metabolism toward gluconeogenesis is also evident in Cln3-knockout mice. Further experimentation will be necessary to understand the contribution of these changes in expression to a disease state. Detailed analysis of the functional consequences of altered expression of genes in the cerebellum of the Cln3-knockout mice may provide valuable clues in understanding the molecular basis of the pathological mechanisms underlying Batten disease.

Spatial learning requires the septohippocampal pathway. The interaction of learning experience with gene products to modulate the function of a pathway may underlie use-dependent plasticity. The regulated release of nerve growth factor (NGF) from hippocampal cultures and hippocampus, as well as its actions on cholinergic septal neurons, suggest it as a candidate protein to interact with a learning experience. A method was used to evaluate NGF gene-experience interaction on the septohippocampal neural circuitry in mice. The method permits brain region-specific expression of a new gene by using a two-component approach: a virus vector directing expression of cre recombinase; and transgenic mice carrying genomic recombination substrates rendered transcriptionally inactive by a “floxed” stop cassette. Cre recombinase vector delivery into transgenic mouse hippocampus resulted in recombination in 30% of infected cells and the expression of a new gene in those cells. To examine the interaction of the NGF gene and experience, adult mice carrying a NGF transgene with a floxed stop cassette (NGFXAT) received a cre recombinase vector to produce localized unilateral hippocampal NGF gene expression, so-called “activated” mice. Activated and control nonactivated NGFXAT mice were subjected to different experiences: repeated spatial learning, repeated rote performance, or standard vivarium housing. Latency, the time to complete the learning task, declined in the repeated spatial learning groups. The measurement of interaction between NGF gene expression and experience on the septohippocampal circuitry was assessed by counting retrogradely labeled basal forebrain cholinergic neurons projecting to the hippocampal site of NGF gene activation. Comparison of all NGF activated groups revealed a graded effect of experience on the septohippocampal pathway, with the largest change occurring in activated mice provided with repeated learning experience. These data demonstrate that plasticity of the adult spatial learning circuitry can be robustly modulated by experience-dependent interactions with a specific hippocampal gene product.

Recently developed helper virus-free methods of herpes simplex virus (HSV) amplicon vector packaging provide stocks that are virtually devoid of the cytotoxic component normally associated with traditional helper virus-based packaging methods. These approaches involve cotransfection of amplicon plasmid DNA with either a five-cosmid set or a bacterial artificial chromosome (BAC) that contains the HSV genome without its cognate pac signals. Helper virus-free amplicon packaging produces low-titer stocks (

THE influence of NGF on the neuroanatomic substrate(s) subserving learning and memory was probed by somatic mosaic analysis. NGF XAT mice underwent unilateral hippocampal delivery of virus vector expressing cre recombinase to produce focal NGF gain of function mosaics. Activated mice expressing increased NGF, but not control mice transduced with the lacZ gene showed reorganization of the septohippocampal projection assessed by retrograde labeling with Fluoro-gold (FG). Mice mosaic for NGF function demonstrated in ipsilateral medial septum and diagonal band significant increases in FG-labeled cell bodies (94%), ChAT-labeled cells (55%), double-positive cells (190%) and increased somal size of double-positive cells (56%) than did non-activated mice. These results indicate that reorganization of the cholinergic septal input to a specific hippocampal region is promoted by gain of NGF function.