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Abstract
Fear extinction is an adaptive process whereby defensive responses are attenuated following repeated experience of prior fear-related stimuli without harm. The formation of extinction memories involves interactions between various corticolimbic structures, resulting in reduced central amygdala (CEA) output. Recent studies show, however, the CEA is not merely an output relay of fear responses but contains multiple neuronal subpopulations that interact to calibrate levels of fear responding. Here, by integrating behavioural, in vivo electrophysiological, anatomical and optogenetic approaches in mice we demonstrate that fear extinction produces reversible, stimulus- and context-specific changes in neuronal responses to conditioned stimuli in functionally and genetically defined cell types in the lateral (CEl) and medial (CEm) CEA. Moreover, we show these alterations are absent when extinction is deficient and that selective silencing of protein kinase C delta-expressing (PKCδ) CEl neurons impairs fear extinction. Our findings identify CEA inhibitory microcircuits that act as critical elements within the brain networks mediating fear extinction.
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Epigenetic Mechanisms Within the Cingulate Cortex Regulate Innate Anxiety-Like Behavior. Int J Neuropsychopharmacol 2019; 22:317-328. [PMID: 30668714 PMCID: PMC6441131 DOI: 10.1093/ijnp/pyz004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Pathological anxiety originates from a complex interplay of genetic predisposition and environmental factors, acting via epigenetic mechanisms. Epigenetic processes that can counteract detrimental genetic risk towards innate high anxiety are not well characterized. METHODS We used female mouse lines of selectively bred high (HAB)- vs low (LAB)-innate anxiety-related behavior and performed select environmental and pharmacological manipulations to alter anxiety levels as well as brain-specific manipulations and immunohistochemistry to investigate neuronal mechanisms associated with alterations in anxiety-related behavior. RESULTS Inborn hyperanxiety of high anxiety-like phenotypes was effectively reduced by environmental enrichment exposure. c-Fos mapping revealed that hyperanxiety in high anxiety-like phenotypes was associated with blunted challenge-induced neuronal activation in the cingulate-cortex, which was normalized by environmental enrichment. Relating this finding with epigenetic modifications, we found that high anxiety-like phenotypes (compared with low-innate anxiety phenotypes) showed reduced acetylation in the hypoactivated cingulate-cortex neurons following a mild emotional challenge, which again was normalized by environmental enrichment. Paralleling the findings using environmental enrichment, systemic administration of histone-deacetylase-inhibitor MS-275 elicited an anxiolytic-like effect, which was correlated with increased acetylated-histone-3 levels within cingulate-cortex. Finally, as a proof-of-principle, local MS-275 injection into cingulate-cortex rescued enhanced innate anxiety and increased acetylated-histone-3 within the cingulate-cortex, suggesting this epigenetic mark as a biomarker for treatment success. CONCLUSIONS Taken together, the present findings provide the first causal evidence that the attenuation of high innate anxiety-like behavior via environmental/pharmacological manipulations is epigenetically mediated via acetylation changes within the cingulate-cortex. Finally, histone-3 specific histone-deacetylase-inhibitor could be of therapeutic importance in anxiety disorders.
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Satb2 determines miRNA expression and long-term memory in the adult central nervous system. eLife 2016; 5. [PMID: 27897969 PMCID: PMC5207769 DOI: 10.7554/elife.17361] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 11/28/2016] [Indexed: 01/09/2023] Open
Abstract
SATB2 is a risk locus for schizophrenia and encodes a DNA-binding protein that regulates higher-order chromatin configuration. In the adult brain Satb2 is almost exclusively expressed in pyramidal neurons of two brain regions important for memory formation, the cerebral cortex and the CA1-hippocampal field. Here we show that Satb2 is required for key hippocampal functions since deletion of Satb2 from the adult mouse forebrain prevents the stabilization of synaptic long-term potentiation and markedly impairs long-term fear and object discrimination memory. At the molecular level, we find that synaptic activity and BDNF up-regulate Satb2, which itself binds to the promoters of coding and non-coding genes. Satb2 controls the hippocampal levels of a large cohort of miRNAs, many of which are implicated in synaptic plasticity and memory formation. Together, our findings demonstrate that Satb2 is critically involved in long-term plasticity processes in the adult forebrain that underlie the consolidation and stabilization of context-linked memory. DOI:http://dx.doi.org/10.7554/eLife.17361.001
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Combined Neuropeptide S and D-Cycloserine Augmentation Prevents the Return of Fear in Extinction-Impaired Rodents: Advantage of Dual versus Single Drug Approaches. Int J Neuropsychopharmacol 2015; 19:pyv128. [PMID: 26625894 PMCID: PMC4926792 DOI: 10.1093/ijnp/pyv128] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/24/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Despite its success in treating specific anxiety disorders, the effect of exposure therapy is limited by problems with tolerability, treatment resistance, and fear relapse after initial response. The identification of novel drug targets facilitating fear extinction in clinically relevant animal models may guide improved treatment strategies for these disorders in terms of efficacy, acceleration of fear extinction, and return of fear. METHODS The extinction-facilitating potential of neuropeptide S, D-cycloserine, and a benzodiazepine was investigated in extinction-impaired high anxiety HAB rats and 129S1/SvImJ mice using a classical cued fear conditioning paradigm followed by extinction training and several extinction test sessions to study fear relapse. RESULTS Administration of D-cycloserine improved fear extinction in extinction-limited, but not in extinction-deficient, rodents compared with controls. Preextinction neuropeptide S caused attenuated fear responses in extinction-deficient 129S1/SvImJ mice at extinction training onset and further reduced freezing during this session. While the positive effects of either D-cycloserine or neuropeptide S were not persistent in 129S1/SvImJ mice after 10 days, the combination of preextinction neuropeptide S with postextinction D-cycloserine rendered the extinction memory persistent and context independent up to 5 weeks after extinction training. This dual pharmacological adjunct to extinction learning also protected against fear reinstatement in 129S1/SvImJ mice. CONCLUSIONS By using the potentially nonsedative anxiolytic neuropeptide S and the cognitive enhancer D-cycloserine to facilitate deficient fear extinction, we provide here the first evidence of a purported efficacy of a dual over a single drug approach. This approach may render exposure sessions less aversive and more efficacious for patients, leading to enhanced protection from fear relapse in the long term.
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Impaired Contextual Fear Extinction Learning is Associated with Aberrant Regulation of CHD-Type Chromatin Remodeling Factors. Front Behav Neurosci 2015; 9:313. [PMID: 26635563 PMCID: PMC4649039 DOI: 10.3389/fnbeh.2015.00313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/03/2015] [Indexed: 02/04/2023] Open
Abstract
Successful attenuation of fearful memories is a cognitive process requiring initiation of highly coordinated transcription programs. Chromatin-modulating mechanisms such as DNA methylation and histone modifications, including acetylation, are key regulators of these processes. However, knowledge concerning the role of ATP-dependent chromatin remodeling factors (ChRFs) being required for successful fear extinction is lacking. Underscoring the potential importance of these factors that alter histone-DNA contacts within nucleosomes are recent genome-wide association studies linking several ChRFs to various human cognitive and psychiatric disorders. To better understand the role of ChRFs in the brain, and since to date little is known about ChRF expression in the brain, we performed a comprehensive survey of expression levels of 24 ATP-dependent remodelers across different brain areas, and we identified several distinct high molecular weight complexes by chromatographic methods. We next aimed to gain novel insight into the potential regulation of ChRFs in different brain regions in association with normal and impaired fear extinction learning. To this end, we established the 129S1/SvImJ (S1) laboratory mouse strain as a model for compromised contextual fear extinction learning that can be rescued by dietary zinc restriction (ZnR). Using this model along with genetically related but fear extinction-competent 129S6/SvEv (S6) mice as controls, we found that impaired fear extinction in S1 was associated with enhanced ventral hippocampal expression of CHD1 and reduced expression of CHD5 that was normalized following successful rescue of impaired fear extinction. Moreover, a select reduction in CHD3 expression was observed in the ventral hippocampus (vHC) following successful rescue of fear extinction in S1 mice. Taken together, these data provide novel insight into the regulation of specific ChRFs following an impaired cognitive process and its rescue, and they suggest that imbalance of CHD-type remodeler levels, which consequently may lead to changes of transcriptional programs, may be an underlying mechanism involved in impaired fear extinction learning and its therapeutic rescue.
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Abstract
Persistent anxiety after a psychological trauma is a hallmark of many anxiety disorders. However, the neural circuits mediating the extinction of traumatic fear memories remain incompletely understood. We show that selective, in vivo stimulation of the ventromedial prefrontal cortex (vmPFC)-amygdala pathway facilitated extinction memory formation, but not retrieval. Conversely, silencing the vmPFC-amygdala pathway impaired extinction formation and reduced extinction-induced amygdala activity. Our data demonstrate a critical instructional role for the vmPFC-amygdala circuit in the formation of extinction memories. These findings advance our understanding of the neural basis of persistent fear, with implications for posttraumatic stress disorder and other anxiety disorders.
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Pharmacology of cognitive enhancers for exposure-based therapy of fear, anxiety and trauma-related disorders. Pharmacol Ther 2014; 149:150-90. [PMID: 25550231 PMCID: PMC4380664 DOI: 10.1016/j.pharmthera.2014.12.004] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 12/24/2014] [Indexed: 12/20/2022]
Abstract
Pathological fear and anxiety are highly debilitating and, despite considerable advances in psychotherapy and pharmacotherapy they remain insufficiently treated in many patients with PTSD, phobias, panic and other anxiety disorders. Increasing preclinical and clinical evidence indicates that pharmacological treatments including cognitive enhancers, when given as adjuncts to psychotherapeutic approaches [cognitive behavioral therapy including extinction-based exposure therapy] enhance treatment efficacy, while using anxiolytics such as benzodiazepines as adjuncts can undermine long-term treatment success. The purpose of this review is to outline the literature showing how pharmacological interventions targeting neurotransmitter systems including serotonin, dopamine, noradrenaline, histamine, glutamate, GABA, cannabinoids, neuropeptides (oxytocin, neuropeptides Y and S, opioids) and other targets (neurotrophins BDNF and FGF2, glucocorticoids, L-type-calcium channels, epigenetic modifications) as well as their downstream signaling pathways, can augment fear extinction and strengthen extinction memory persistently in preclinical models. Particularly promising approaches are discussed in regard to their effects on specific aspects of fear extinction namely, acquisition, consolidation and retrieval, including long-term protection from return of fear (relapse) phenomena like spontaneous recovery, reinstatement and renewal of fear. We also highlight the promising translational value of the preclinial research and the clinical potential of targeting certain neurochemical systems with, for example d-cycloserine, yohimbine, cortisol, and L-DOPA. The current body of research reveals important new insights into the neurobiology and neurochemistry of fear extinction and holds significant promise for pharmacologically-augmented psychotherapy as an improved approach to treat trauma and anxiety-related disorders in a more efficient and persistent way promoting enhanced symptom remission and recovery.
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Temporal factors in the extinction of fear in inbred mouse strains differing in extinction efficacy. BIOLOGY OF MOOD & ANXIETY DISORDERS 2013; 3:13. [PMID: 23830244 PMCID: PMC3726460 DOI: 10.1186/2045-5380-3-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 05/23/2013] [Indexed: 11/10/2022]
Abstract
BACKGROUND Various neuropsychiatric conditions, including posttraumatic stress disorder (PTSD), are characterized by deficient fear extinction, but individuals differ greatly in risk for these. While there is growing evidence that fear extinction is influenced by certain procedural variables, it is unclear how these influences might vary across individuals and subpopulations. To model individual differences in fear extinction, prior studies identified a strain of inbred mouse, 129S1/SvImJ (S1), which exhibits a profound deficit in fear extinction, as compared to other inbred strains, such as C57BL/6J (B6). METHODS Here, we assessed the effects of procedural variables on the impaired extinction phenotype of the S1 strain and, by comparison, the extinction-intact B6 strain. The variables studied were 1) the interval between conditioning and extinction, 2) the interval between cues during extinction training, 3) single-cue exposure before extinction training, and 4) extinction of a second-order conditioned cue. RESULTS Conducting extinction training soon after ('immediately') conditioning attenuated fear retrieval in S1 mice and impaired extinction in B6 mice. Spacing cue presentations with long inter-trial intervals during extinction training augmented fear in S1 and B6 mice. The effect of spacing was lost with one-trial fear conditioning in B6, but not S1 mice. A single exposure to a conditioned cue before extinction training did not alter extinction retrieval, either in B6 or S1 mice. Both the S1 and B6 strains exhibited robust second-order fear conditioning, in which a cue associated with footshock was sufficient to serve as a conditioned exciter to condition a fear association to a second cue. B6 mice extinguished the fear response to the second-order conditioned cue, but S1 mice failed to do so. CONCLUSIONS These data provide further evidence that fear extinction is strongly influenced by multiple procedural variables and is so in a highly strain-dependent manner. This suggests that the efficacy of extinction-based behavioral interventions, such as exposure therapy, for trauma-related anxiety disorders will be determined by the procedural parameters employed and the degree to which the patient can extinguish.
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Deep brain stimulation, histone deacetylase inhibitors and glutamatergic drugs rescue resistance to fear extinction in a genetic mouse model. Neuropharmacology 2013; 64:414-23. [PMID: 22722028 PMCID: PMC3474950 DOI: 10.1016/j.neuropharm.2012.06.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/31/2012] [Accepted: 06/06/2012] [Indexed: 12/16/2022]
Abstract
Anxiety disorders are characterized by persistent, excessive fear. Therapeutic interventions that reverse deficits in fear extinction represent a tractable approach to treating these disorders. We previously reported that 129S1/SvImJ (S1) mice show no extinction learning following normal fear conditioning. We now demonstrate that weak fear conditioning does permit fear reduction during massed extinction training in S1 mice, but reveals specific deficiency in extinction memory consolidation/retrieval. Rescue of this impaired extinction consolidation/retrieval was achieved with d-cycloserine (N-methly-d-aspartate partial agonist) or MS-275 (histone deacetylase (HDAC) inhibitor), applied after extinction training. We next examined the ability of different drugs and non-pharmacological manipulations to rescue the extreme fear extinction deficit in S1 following normal fear conditioning with the ultimate aim to produce low fear levels in extinction retrieval tests. Results showed that deep brain stimulation (DBS) by applying high frequency stimulation to the nucleus accumbens (ventral striatum) during extinction training, indeed significantly reduced fear during extinction retrieval compared to sham stimulation controls. Rescue of both impaired extinction acquisition and deficient extinction consolidation/retrieval was achieved with prior extinction training administration of valproic acid (a GABAergic enhancer and HDAC inhibitor) or AMN082 [metabotropic glutamate receptor 7 (mGlu7) agonist], while MS-275 or PEPA (AMPA receptor potentiator) failed to affect extinction acquisition in S1 mice. Collectively, these data identify potential beneficial effects of DBS and various drug treatments, including those with HDAC inhibiting or mGlu7 agonism properties, as adjuncts to overcome treatment resistance in exposure-based therapies. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Histone deacetylase inhibitors, glutamatergic drugs and deep brain stimulation rescue resistance to fear extinction in a genetic mouse model. BMC Pharmacol Toxicol 2012. [PMCID: PMC3506301 DOI: 10.1186/2050-6511-13-s1-a42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Identification of the Polyphenols in Barley and Beer by HPLC/MS and HPLC/Electrochemical Detection. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.1999.tb00011.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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129S1/SvImJ mice display impaired contextual fear extinction, enhanced fear incubation and deficit extinction consolidation phenotypes: rescue via pharmacological and non-pharmacological treatments. BMC Pharmacol 2011. [PMCID: PMC3194273 DOI: 10.1186/1471-2210-11-s2-a39] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Modulation of magnesium deficiency-induced anxiety and HPA axis dysregulation by therapeutic drug treatment. BMC Pharmacol 2011. [PMCID: PMC3194275 DOI: 10.1186/1471-2210-11-s2-a40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Magnesium deficiency induces anxiety and HPA axis dysregulation: modulation by therapeutic drug treatment. Neuropharmacology 2011; 62:304-12. [PMID: 21835188 PMCID: PMC3198864 DOI: 10.1016/j.neuropharm.2011.07.027] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/16/2011] [Accepted: 07/18/2011] [Indexed: 01/12/2023]
Abstract
Preclinical and some clinical studies suggest a relationship between perturbation in magnesium (Mg2+) homeostasis and pathological anxiety, although the underlying mechanisms remain largely unknown. Since there is evidence that Mg2+ modulates the hypothalamic-pituitary adrenal (HPA) axis, we tested whether enhanced anxiety-like behaviour can be reliably elicited by dietary Mg2+ deficiency and whether Mg2+ deficiency is associated with altered HPA axis function. Compared with controls, Mg2+ deficient mice did indeed display enhanced anxiety-related behaviour in a battery of established anxiety tests. The enhanced anxiety-related behaviour of Mg2+ deficient mice was sensitive to chronic desipramine treatment in the hyponeophagia test and to acute diazepam treatment in the open arm exposure test. Mg2+ deficiency caused an increase in the transcription of the corticotropin releasing hormone in the paraventricular hypothalamic nucleus (PVN), and elevated ACTH plasma levels, pointing to an enhanced set-point of the HPA axis. Chronic treatment with desipramine reversed the identified abnormalities of the stress axis. Functional mapping of neuronal activity using c-Fos revealed hyper-excitability in the PVN of anxious Mg2+ deficient mice and its normalisation through diazepam treatment. Overall, the present findings demonstrate the robustness and validity of the Mg2+ deficiency model as a mouse model of enhanced anxiety, showing sensitivity to treatment with anxiolytics and antidepressants. It is further suggested that dysregulations in the HPA axis may contribute to the hyper-emotionality in response to dietary induced hypomagnesaemia. This article is part of a Special Issue entitled ‘Anxiety and Depression’.
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Changes in brain protein expression are linked to magnesium restriction-induced depression-like behavior. Amino Acids 2011; 40:1231-48. [DOI: 10.1007/s00726-010-0758-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Accepted: 01/31/2011] [Indexed: 01/22/2023]
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Rescue of impaired fear extinction and normalization of cortico-amygdala circuit dysfunction in a genetic mouse model by dietary zinc restriction. J Neurosci 2010; 30:13586-96. [PMID: 20943900 PMCID: PMC3149823 DOI: 10.1523/jneurosci.0849-10.2010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 05/31/2010] [Accepted: 07/16/2010] [Indexed: 11/21/2022] Open
Abstract
Fear extinction is impaired in neuropsychiatric disorders, including posttraumatic stress disorder. Identifying drugs that facilitate fear extinction in animal models provides leads for novel pharmacological treatments for these disorders. Zinc (Zn) is expressed in neurons in a cortico-amygdala circuit mediating fear extinction, and modulates neurotransmitter systems regulating extinction. We previously found that the 129S1/SvImJ mouse strain (S1) exhibited a profound impairment in fear extinction, coupled with abnormalities in the activation of the extinction circuit. Here, we tested the role of Zn in fear extinction in S1 and C57BL/6N reference strain (B6) by feeding the mice a Zn-restricted diet (ZnR) and testing for fear extinction, as well as neuronal activation of the extinction circuit via quantification of the immediate-early genes c-Fos and Zif268. Results showed that (preconditioning or postconditioning) ZnR completely rescued deficient extinction learning and long-term extinction retrieval in S1 and expedited extinction learning in B6, without affecting fear acquisition or fear expression. The extinction-facilitating effects of ZnR were associated with the normalization of Zif268 and/or c-Fos expression in cortico-amygdala regions of S1. Specifically, ZnR increased activity in infralimbic cortex, lateral and basolateral amygdala nuclei, and lateral central amygdala nucleus, and decreased activity in prelimbic and insular cortices and medial central amygdala nucleus. ZnR also increased activation in the main intercalated nucleus and decreased activation of the medial paracapsular intercalated mass in S1. Our findings reveal a novel role for Zn in fear extinction and further support the utility of the S1 model for identifying extinction facilitating drugs.
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Serotonin(1A)-receptor-dependent signaling proteins in mouse hippocampus. Neuropharmacology 2009; 57:556-66. [PMID: 19607848 DOI: 10.1016/j.neuropharm.2009.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 06/30/2009] [Accepted: 07/07/2009] [Indexed: 11/18/2022]
Abstract
The serotonin(1A) receptor (5-HT(1A) R) knock-out mouse (KO) is a widely used animal model for anxiety and cognitive function and regulation of signaling cascades by this receptor has been reported. We aimed to determine individual representatives of signaling cascades in order to screen 5-HT(1A) R-dependent signaling proteins (SPs). Hippocampal proteins from wild type and 5-HT(1A) R KO mice were extracted, run on two-dimensional gel electrophoresis, proteins were identified by MALDI and nano-ESI-LC-MS/MS and SPs were quantified by specific software. Nucleoside diphosphate kinase A (NDK A, synonym: nm23), Dual specificity mitogen-activated protein kinase kinase 1 (MAPKK1, synonym: MEK), Serine/threonine-protein phosphatase PP1-gamma catalytic subunit (PP-1G), Septin-5, were reduced in the KO mice. Novel phosphorylation sites at T386 on MAPKK1 and at S225 and Y265 on Septin-5 were observed. MAPKK1 and PP-1G are known 5-HT(1A) R-dependent signaling compounds and are in agreement with receptor knock-out and septin-5 is involved in serotonin transport, although regulation by 5-HT(1A) R has not been reported. 5-HT(1A) R - dependent levels for NDK A have not been demonstrated so far and we herewith propose a role for NDK A in 5-HT(1A) R signaling. Reduced SP levels along with findings of two novel phosphorylation sites may be relevant for interpretation of previous and the design of future studies on this receptor system.
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MESH Headings
- Amino Acid Sequence
- Analysis of Variance
- Animals
- Blotting, Western
- Cytoskeletal Proteins/genetics
- Cytoskeletal Proteins/metabolism
- Databases, Genetic
- Electrophoresis, Gel, Two-Dimensional
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/metabolism
- Hippocampus/metabolism
- MAP Kinase Kinase 1/genetics
- MAP Kinase Kinase 1/metabolism
- Mice
- Mice, Knockout
- NM23 Nucleoside Diphosphate Kinases/metabolism
- Phosphorylation
- Protein Phosphatase 1/metabolism
- Receptor, Serotonin, 5-HT1A/genetics
- Receptor, Serotonin, 5-HT1A/metabolism
- Septins
- Signal Transduction
- Software
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Impaired Pavlovian fear extinction is a common phenotype across genetic lineages of the 129 inbred mouse strain. GENES BRAIN AND BEHAVIOR 2009; 8:744-52. [PMID: 19674120 DOI: 10.1111/j.1601-183x.2009.00519.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Fear extinction is impaired in psychiatric disorders such as post-traumatic stress disorder and schizophrenia, which have a major genetic component. However, the genetic factors underlying individual variability in fear extinction remain to be determined. By comparing a panel of inbred mouse strains, we recently identified a strain, 129S1/SvImJ (129S1), that exhibits a profound and selective deficit in Pavlovian fear extinction, and associated abnormalities in functional activation of a key prefrontal-amygdala circuit, as compared with C57BL/6J. The first aim of the present study was to assess fear extinction across multiple 129 substrains representing the strain's four different genetic lineages (parental, steel, teratoma and contaminated). Results showed that 129P1/ReJ, 129P3/J, 129T2/SvEmsJ and 129X1/SvJ exhibited poor fear extinction, relative to C57BL/6J, while 129S1 showed evidence of fear incubation. On the basis of these results, the second aim was to further characterize the nature and specificity of the extinction phenotype in 129S1, as an exemplar of the 129 substrains. Results showed that the extinction deficit in 129S1 was neither the result of a failure to habituate to a sensitized fear response nor an artifact of a fear response to (unconditioned) tone per se. A stronger conditioning protocol (i.e. five x higher intensity shocks) produced an increase in fear expression in 129S1, relative to C57BL/6J, due to rapid rise in freezing during tone presentation. Taken together, these data show that impaired fear extinction is a phenotypic feature common across 129 substrains, and provide preliminary evidence that impaired fear extinction in 129S1 may reflect a pro-fear incubation-like process.
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Conditional mouse mutants highlight mechanisms of corticotropin-releasing hormone effects on stress-coping behavior. Mol Psychiatry 2008; 13:1028-42. [PMID: 18475271 DOI: 10.1038/mp.2008.51] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hypersecretion of central corticotropin-releasing hormone (CRH) has been implicated in the pathophysiology of affective disorders. Both, basic and clinical studies suggested that disrupting CRH signaling through CRH type 1 receptors (CRH-R1) can ameliorate stress-related clinical conditions. To study the effects of CRH-R1 blockade upon CRH-elicited behavioral and neurochemical changes we created different mouse lines overexpressing CRH in distinct spatially restricted patterns. CRH overexpression in the entire central nervous system, but not when overexpressed in specific forebrain regions, resulted in stress-induced hypersecretion of stress hormones and increased active stress-coping behavior reflected by reduced immobility in the forced swim test and tail suspension test. These changes were related to acute effects of overexpressed CRH as they were normalized by CRH-R1 antagonist treatment and recapitulated the effect of stress-induced activation of the endogenous CRH system. Moreover, we identified enhanced noradrenergic activity as potential molecular mechanism underlying increased active stress-coping behavior observed in these animals. Thus, these transgenic mouse lines may serve as animal models for stress-elicited pathologies and treatments that target the central CRH system.
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Conditional CRH overexpressing mice: an animal model for stress-elicited pathologies and treatments that target the central CRH system. Mol Psychiatry 2008; 13:989. [PMID: 18936754 DOI: 10.1038/mp.2008.107] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Neurokinin 1 receptor antagonism promotes active stress coping via enhanced septal 5-HT transmission. Neuropsychopharmacology 2008; 33:1929-41. [PMID: 17957216 DOI: 10.1038/sj.npp.1301594] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antagonists of the substance P (SP) preferring neurokinin 1 receptor (NK1R) represent a promising novel class of drugs for the treatment of stress-related disorders such as depression and anxiety disorders; however, the involved neuronal pathways releasing SP in response to stressors are ill defined. By using in vivo microdialysis in combination with a highly sensitive and selective radioimmunoassay we found that exposure to forced swim stress increased SP release in the rat lateral septum (LS), a key area in processing emotions and stress responses. Acute administration of the selective NK1R antagonist L-822429 injected either systemically or locally into the LS reduced passive and facilitated active stress-coping strategies in the forced swim test. This effect seems to be mediated by enhanced intraseptal serotonergic transmission via serotonin (5-HT)1A receptors since NK1R blockade reversed the swim stress-induced decrease to an increase in extracellular 5-HT efflux, and furthermore the behavioral effects of L-822429 were blocked by intraseptal 5-HT1A receptor antagonism. A direct heterosynaptic regulation by NK1R on 5-HT release from serotonergic fibers was ruled out by immunocytochemistry at the light and electron microscopic level indicating involvement of GABAergic interneuron(s) in this interaction. Taken together, our data identify the LS as a critical brain area for the involvement of SP transmission in the modulation of stress responses and demonstrate that NK1R blockade can elicit a functionally significant facilitatory effect on 5-HT transmission, which does not necessarily involve the previously proposed interaction with neuronal firing at the cell body level of raphe neurons.
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Fetal Down syndrome brains exhibit aberrant levels of neurotransmitters critical for normal brain development. Pediatrics 2007; 120:e1465-71. [PMID: 17998315 DOI: 10.1542/peds.2006-3448] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND In the immature developing fetal brain, amino acids (such as gamma-aminobutyric acid, and taurine) and monoamines (serotonin, noradrenaline, and dopamine) act as developmental signals or regulators. In subjects with Down syndrome, dysfunctional brain development is evident from birth as reduction in brain weight, as well as volume reductions in specific brain regions, and an altered number of neurons, dendrites, and dendritic branching is observed. However, mechanisms that underlie the observed dysfunctional brain development in Down syndrome are not clear. OBJECTIVES Because diverse amino acids and monoamines are critical for normal brain development, we wanted to determine whether dysfunctional brain development observed in subjects with Down syndrome is associated with altered brain amino acid and/or monoamine levels. DESIGN/METHODS We quantified tissue concentrations of diverse amino acids, including gamma-aminobutyric acid and taurine, and the monoamines serotonin, noradrenaline, and dopamine in the frontal cortex of fetal Down syndrome tissue at a gestational age of approximately 20 weeks versus age-matched control aborted fetuses. RESULTS Fetal Down syndrome brains showed reductions in the levels of serotonin, gamma-aminobutyric acid, taurine, and dopamine in the frontal cortex. No alteration in the levels of arginine, aspartate, glutamine, glutamate, glycine, histidine, serine, or noradrenaline was observed. CONCLUSIONS Serotonin, gamma-aminobutyric acid, taurine, and dopamine are critical for the acquisition of brain morphologic features, neuronal and glia proliferation, and synapse formation. The detected reductions in the levels of these neurotransmitters may indicate potential mechanisms for the observed dysfunctional neuronal development in the Down syndrome fetal brain.
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Neurokinin 1 receptor antagonism promotes active stress coping via enhanced septal 5-HT transmission. BMC Pharmacol 2007; 7 Suppl 2:A1-77. [PMID: 18053119 PMCID: PMC3226098 DOI: 10.1186/1471-2210-7-s2-a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Uptake of postnatal services for mothers of newborn babies up to eight weeks of age. THE NEW ZEALAND MEDICAL JOURNAL 1999; 112:395-8. [PMID: 10606400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
AIM Significant changes have occurred in the way postnatal care is funded in New Zealand since July 1996. This study investigated three aspects of postnatal care: the uptake of the six-week check, the six-week immunisation and breast feeding rates. METHOD A prospective prevalence survey of 504 mothers of newborn babies recruited from birthing centres in urban Auckland over the period November 1997 to February 1998. A postal questionnaire was sent at ten weeks postnatal, covering issues concerning the six-week check, six-week immunisation and breast feeding. RESULTS Four hundred and four completed questionnaires were obtained (82%); 98% of respondents had obtained a six-week check and 90% a six-week immunisation for their infant. Infants who received their six-week check from a general practitioner were more likely to be immunised. Younger mothers (15-19 years) and older mothers (35 years plus) were less likely to have immunised children. Of reasons given for not immunising, 43% were concerns over immaturity of the baby and 27% because the child was not well. At birth, 88% of mothers were fully breast feeding and 62% at six-weeks postnatal. Of the reasons given for stopping feeding, 41% stated insufficient milk or poor weight gain and 15% stated failure to establish feeding. CONCLUSIONS Removing the six- week check from a general practitioner check and splitting it from the immunisation, has a deleterious effect on immunisation uptake. Mothers, particularly under 20 years, but also 35 years plus, are less likely to have immunised infants. A significant number of unimmunised babies arose from concerns that the baby may be too immature. The rate of breast feeding in New Zealand is continuing to drop. Actual rates fall well below mothers' desires to breast feed. Reasons given for stopping breast feeding point to a general need for greater postnatal support. The high rate of failure to establish feeding raises concerns over lack of early postnatal support. In July 1996 significant changes in payment of the maternity services benefit were introduced in New Zealand. In particular, postnatal services previously paid on a 'fee-for-service' basis were altered to a set capped amount for the 'postnatal module'. This led to concerns that care in the postnatal period had become more limited. In particular, there were anecdotal reports of the six-week check not being given, or being given by a range of providers who did not necessarily offer the opportunity for immunisation at the time of the check. Recent concerns have also been expressed about the apparent dropping immunisation rates in New Zealand, and the dropping breast feeding rates. The present study, developed in response to these concerns investigated three aspects of postnatal care: (a) The incidence of the uptake of the six-week check and whether mothers perceived any barriers to access. (b) The incidence of the uptake of the six-week immunisation and whether mothers perceived any barriers to access. (c) The rate of breast feeding and what barriers mothers perceived to continuing to breast feed.
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Regulation of T cell activation in vitro and in vivo by targeting the OX40-OX40 ligand interaction: amelioration of ongoing inflammatory bowel disease with an OX40-IgG fusion protein, but not with an OX40 ligand-IgG fusion protein. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1999; 162:486-93. [PMID: 9886424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
OX40 is a member of the TNFR superfamily, and is found predominantly on activated CD4-positive T cells. In vitro an OX40-IgG fusion protein inhibits mitogen- and Ag-driven proliferation and cytokine release by splenocytes and lymph node T cells. In contrast, an OX40 ligand-IgG fusion protein enhanced proliferative responses. In normal mice, OX40-positive cells are observed only in lymphoid tissues, including Peyer's patches of the gut. In mice with hapten-induced colitis or IL-2 knockout mice with spontaneous colitis, OX40-positive cells are found infiltrating the lamina propria. Administration of the OX40-IgG fusion protein to mice with ongoing colitis (but not the OX40 ligand-IgG) ameliorated disease in both mouse models of inflammatory bowel disease. This was evidenced by a reduction in tissue myeloperoxidase; reduced transcripts for TNF-alpha, IL-1, IL-12, and IFN-gamma; and a reduction in the T cell infiltrate. Targeting OX40 therefore shows considerable promise as a new strategy to inhibit ongoing T cell reactions in the gut.
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MESH Headings
- Animals
- CHO Cells
- Colitis/genetics
- Colitis/immunology
- Colitis/therapy
- Concanavalin A/pharmacology
- Cricetinae
- Cytokines/biosynthesis
- Epitopes, T-Lymphocyte/immunology
- Female
- Humans
- Immunoglobulin G/genetics
- Immunoglobulin G/physiology
- Inflammatory Bowel Diseases/genetics
- Inflammatory Bowel Diseases/immunology
- Inflammatory Bowel Diseases/therapy
- Injections, Intraperitoneal
- Interleukin-2/deficiency
- Interleukin-2/genetics
- Ligands
- Lymphocyte Activation/genetics
- Membrane Glycoproteins
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Knockout
- OX40 Ligand
- Receptors, OX40
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/therapeutic use
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Tumor Necrosis Factor Receptor Superfamily, Member 7/biosynthesis
- Tumor Necrosis Factor Receptor Superfamily, Member 7/genetics
- Tumor Necrosis Factor Receptor Superfamily, Member 7/physiology
- Tumor Necrosis Factors
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Regulation of T Cell Activation In Vitro and In Vivo by Targeting the OX40-OX40 Ligand Interaction: Amelioration of Ongoing Inflammatory Bowel Disease with an OX40-IgG Fusion Protein, But Not with an OX40 Ligand-IgG Fusion Protein. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.1.486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
OX40 is a member of the TNFR superfamily, and is found predominantly on activated CD4-positive T cells. In vitro an OX40-IgG fusion protein inhibits mitogen- and Ag-driven proliferation and cytokine release by splenocytes and lymph node T cells. In contrast, an OX40 ligand-IgG fusion protein enhanced proliferative responses. In normal mice, OX40-positive cells are observed only in lymphoid tissues, including Peyer’s patches of the gut. In mice with hapten-induced colitis or IL-2 knockout mice with spontaneous colitis, OX40-positive cells are found infiltrating the lamina propria. Administration of the OX40-IgG fusion protein to mice with ongoing colitis (but not the OX40 ligand-IgG) ameliorated disease in both mouse models of inflammatory bowel disease. This was evidenced by a reduction in tissue myeloperoxidase; reduced transcripts for TNF-α, IL-1, IL-12, and IFN-γ; and a reduction in the T cell infiltrate. Targeting OX40 therefore shows considerable promise as a new strategy to inhibit ongoing T cell reactions in the gut.
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The Encyclopadia of Molecular Biology by J. Kendrew and E. Lawrence Blackwell Science, 1994. P99.50 hbk (1165 pages) ISBN 0 632 02182 9. Trends Genet 1995. [DOI: 10.1016/s0168-9525(00)89111-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
CD44 is a polymorphic cell surface glycoprotein, currently proposed to be the principal cell surface receptor for hyaluronan. However, different isoforms of CD44, expressed in human lymphoid tumor cells, appear to have distinct effects on the ability of the cells to attach to hyaluronan-coated surfaces and on their capacity to form tumors in vivo. In the present study, we address the mechanisms that may regulate CD44 isoform-dependent adhesion to hyaluronan. We use a human Burkitt lymphoma, stably transfected with six different alternatively spliced human CD44 isoforms, to determine their potential hyaluronan binding and tumor growth promoting roles. We show that transfectants expressing CD44 splice variants that contain variable exons 6–10, 7–10 and 8–10 adhere to hyaluronan-coated surfaces weakly and that corresponding tumor formation in vivo is delayed with respect to CD44-negative parental cell-derived tumors. Abundant shedding of these three isoforms may play a significant role in determining the rate of tumor development. Transfectants expressing variable exon 3, on the other hand, fail to display CD44-mediated adhesion to hyaluronan, but form bone marrow tumors rapidly following intravenous injection. These observations suggest that different mechanisms regulate CD44-mediated adhesion and tumor growth, and provide evidence that expression of exon v3 may confer novel ligand-binding properties.
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Proteoglycan forms of the lymphocyte homing receptor CD44 are alternatively spliced variants containing the v3 exon. J Cell Biol 1995; 128:673-85. [PMID: 7532175 PMCID: PMC2199896 DOI: 10.1083/jcb.128.4.673] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The CD44 cell surface glycoprotein is expressed on a broad range of different tissues as multiple isoforms containing from one to ten alternatively spliced exons v1-v10 inserted within the extracellular domain. Differential glycosylation generates still further variability, yielding both N- and O-glycan-modified forms of CD44 in addition to proteoglycan-like variants containing chondroitin sulphate and heparan sulphate. These high molecular mass proteoglycan-like variants, previously identified in lymphocytes, melanomas, and keratinocytes have been implicated in cell-matrix adhesion, cell motility, and invasiveness. More recently, monocyte CD44 molecules presumed to carry glycosaminoglycan chains were shown to bind the chemokine MIP-1 beta (Tanaka, Y.,D. H. Adams, S. Hubscher, H. Hirano, U. Siebenlist, and S. Shaw. 1993. Nature (Lond). 361:79-82.) raising the intriguing possibility that proteoglycan-like CD44 variants might play a role in regulating inflammatory responses. Here we have investigated the molecular identity of these proteoglycan-like CD44 variants by generating a panel of recombinant CD44 isoforms using a novel cassette cloning strategy. We show that both chondroitin and heparan sulphate modifications are associated specifically with isoforms (CD44v3-10 and CD44v3,8-10) containing the v3 alternative exon which encodes a consensus motif SGXG for GAG addition. Other isoforms (CD44v10, CD44v8-10, CD44v7-10, and CD44v6-10) are shown to lack these GAG chains but to carry extensive O-glycan modifications, most likely within the mucin-like alternative exon inserts. We also demonstrate that the majority of endogenous GAG-modified CD44 isoforms present in epithelial cells constitute v3 isoforms thus establishing that in these cells the majority of proteoglycan-like CD44 variants are generated by alternative splicing. Finally we present evidence using transfected B lymphoma cells that the GAG-modified CD44 isoforms CD44v3-10 and CD44v3,8-10, unlike CD44H, bind only weakly to hyaluronan. Together with the demonstration in the accompanying paper (Bennett, K., D. G. Jackson, J.C. Simon, E. Tanczos, R. Peach, B. Modrell, I. Stamenkovic, G. Plowman, and A. Aruffo. 1995. J. Cell Biol. 128:687-698.), that CD44 molecules containing the v3 exon bind growth factors, these results highlight a new and potentially important role for CD44 alternative splicing in the control of cell-surface proteoglycan expression.
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Generation and characterization of a recombinant/chimeric B72.3 (human gamma 1). Cancer Res 1991; 51:181-9. [PMID: 1988082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We report here the generation and characterization of a recombinant/chimeric construct of murine gamma 1 monoclonal antibody (MAb) B72.3, containing the murine variable region and a human gamma 1 constant region [designated cB72.3(gamma i)]. cB72.3(gamma 1) was generated by first isolating functionally rearranged VH and VL genes of B72.3 from partial genomic libraries in phage vectors. Construction of mouse-human chimeric heavy and light chain genes was performed by inserting restriction fragments carrying VL and VH regions of B72.3 into unique sites of expression vectors which contains sequences encoding constant regions of human kappa and gamma 1, respectively. The expression constructs were subsequently electroporated into SP2/0 cells. The transfected SP2/0 murine cell line has been shown to synthesize cB72.3(gamma 1) at a level of 10-20 micrograms/ml. Reciprocal competition radioimmunoassays demonstrated that cB72.3(gamma 1), a previously described cB72.3(gamma 4), and native B72.3 (designated nB72.3) competed similarly. A rat anti-idiotype MAb made against nB72.3 was shown to bind equally well to cB72.3(gamma 1) and to the nB72.3. Immunochemical studies of the nB72.3, cB72.3(gamma 4), and cB72.3(gamma 1) revealed slight differences in size among the three MAb forms on sodium dodecyl sulfate gels and revealed a higher isoelectric point for the cB72.3(gamma 1). Antibody-dependent cell-mediated cytotoxicity experiments using human lymphokine-activated killer effector cells indicated better tumor cell killing by the cB72.3(gamma 1) than the nB72.3 or cB72.3(gamma 4). Dual label studies of coinjected cB72.3(gamma 1) and nB72.3 revealed that both MAbs could efficiently localize human tumor xenografts in athymic mice. Pharmacokinetic studies, analyzing the blood clearance of cB72.3(gamma 1), cB72.3(gamma 4), and nB72.3 in mice, showed that the nB72.3 beta phase of clearance was slower than that of other MAb forms. However, when the pharmacokinetic patterns of these three MAbs forms were analyzed in monkeys, the cB72.3(gamma 1) and the nB72.3 showed similar clearance curves, while the cB72.3(gamma 4) showed a much slower plasma clearance. In view of the binding properties of nB72.3 and its ability to localize a range of carcinomas in clinical trials, the studies reported here demonstrate that the cB72.3(gamma 1) may serve as a potentially useful diagnostic and/or therapeutic reagent.
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Characterization and biodistribution of recombinant and recombinant/chimeric constructs of monoclonal antibody B72.3. Cancer Res 1989; 49:1738-45. [PMID: 2924317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
B72.3 is a murine monoclonal antibody (IgG1) that recognizes a tumor-associated glycoprotein, termed TAG-72. B72.3 has been shown, using a variety of methodologies, to have a high degree of selective reactivity for colorectal, ovarian, lung, and breast carcinomas. Radiolabeled B72.3 has been administered both i.v. and i.p. in patients with colorectal and ovarian cancer as well as other carcinomas and has been shown to selectively bind to approximately 70-80% of metastatic lesions. Greater than 50% of the patients that have been treated with B72.3 have developed an immunological response to murine IgG after a single injection. In an attempt to minimize the immune response of these patients to the administered murine monoclonal antibody, we developed a recombinant form of the murine B72.3 as well as a recombinant/chimeric antibody, using the variable regions of the murine B72.3 and human heavy chain (gamma 4) and light chain (kappa) constant regions. We report here that both the recombinant B72.3 [rB72.3] and the recombinant/chimeric B72.3 [cB72.3(gamma 4)] IgGs maintain the tissue binding and idiotypic specificity of the native murine IgG. The native B72.3, rB72.3, and cB72.3(gamma 4) IgGs were radiolabeled and the biodistribution of these IgGs was studied in athymic mice bearing human colon carcinoma xenografts (LS-174T). Differences were observed between the cB72.3(gamma 4) and the native B72.3 in the percentage of injected dose/g that localized in the tumor. The somewhat lower absolute amounts of the cB72.3(gamma 4) in the tumor are mostly likely due to the observed more rapid clearance from the blood and body of the mouse as compared to the native B72.3 and rB72.3. All three forms [native B72.3, rB72.3, and cB72.3(gamma 4)] of the IgG, however, were able to localize the colon tumor with similar radiolocalization indices [percentage of injected dose/g in tumor divided by the percentage of injected dose/g in normal tissue].
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Abstract
B72.3 is a mouse hybridoma cell-line secreting an IgG1 antibody which recognises an epitope on a tumour-associated antigen, TAG-72. This high molecular weight mucin-like molecule is found on a variety of human neoplasms, including colon, breast and ovarian carcinomas. Chimaeric immunoglobulin genes with the B72.3 specificity have been constructed by joining the mouse variable regions from cDNA clones to human genomic constant regions using recombinant DNA techniques. The chimaeric heavy and light chain immunoglobulin genes were placed under the control of a strong viral promoter, and co-transfected into COS-1 cells. SDS-PAGE analysis of the 35S-labelled products demonstrated that the transiently expressed antibodies were correctly synthesised and assembled. The specific binding characteristics of the parent B72.3 antibody were retained by the chimaeric antibody in an antigen-based ELISA. This system gave sufficiently high transient expression of the chimaeric antibody molecules to allow rapid physical and immunological characterisation of the engineered gene products.
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Megakaryoblastic transformation of myelofibrosis with expression of the c-sis oncogene. SCANDINAVIAN JOURNAL OF HAEMATOLOGY 1986; 36:186-93. [PMID: 2422734 DOI: 10.1111/j.1600-0609.1986.tb00826.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We describe a case of primary myelofibrosis which terminated in an acute megakaryoblastic leukaemia with massive marrow fibrosis and osteosclerosis. The megakaryocyte lineage of the terminal phase was confirmed by ultrastructural and surface marker studies of the blast cells. The leukaemic phase was associated with the presence of large numbers of progressively more immature megakaryocyte progenitors in the peripheral blood. The expression of c-sis mRNA in these blast cells was significantly higher than in normal mononuclear cells. Activation of the c-sis protooncogene leading to increased production of platelet-derived growth factor could be related to the progressive fibrosis observed.
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Expression of epidermal growth factor receptors on human cervical, ovarian, and vulval carcinomas. Cancer Res 1986; 46:285-92. [PMID: 2998607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We describe the properties of two monoclonal antibodies produced to a synthetic peptide consisting of residues 985 to 996 from the cytoplasmic domain of the epidermal growth factor (EGF) receptor. We have examined a group of ten human tumors including cervical, ovarian, and vulval carcinomas for expression of EGF receptors by immunohistological staining using one of these antibodies and another monoclonal antibody to the extracellular domain of the molecule. The tumors were examined using a sensitive amplified enzyme system and a less sensitive indirect staining method. There was generally a good correlation in staining intensity with the two monoclonal antibody reagents. Both antibodies showed strong staining of squamous cell carcinomas and usually weak or heterogeneous patterns with the adenocarcinomas. Samples of each tumor were solubilized in detergent and analyzed for the presence of functional EGF receptors by immunoprecipitation and autophosphorylation. Three of the squamous cell tumors gave labeled bands, Mr 170,000, on sodium dodecyl sulfate:polyacrylamide gels. DNA was extracted from seven of the tumors and digested with two restriction endonucleases, and the fragments were analyzed on Southern blots using probes representing the extracellular and cytoplasmic domains of the molecule. The tumor DNA showed no apparent rearrangements or amplifications when compared to the EGF receptor gene in human placental DNA. These results suggest that there is a high level of EGF receptors on some squamous cell tumors.
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The structure and function of the epidermal growth factor receptor studied by using antisynthetic peptide antibodies. PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. SERIES B, BIOLOGICAL SCIENCES 1985; 226:127-34. [PMID: 2866520 DOI: 10.1098/rspb.1985.0087] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human epidermal growth factor receptor has been purified and partial amino acid sequence obtained. A synthetic oligonucleotide was used to select complementary DNA clones from placental and A431 clone banks. The nucleotide sequence of a 5.8 kilobase transcript was determined and used to predict the total amino acid sequence of the receptor. We have predicted a model for the receptor which has an external ligand binding domain of 621 amino acids, a transmembrane region of 23 amino acids, and a cytoplasmic domain of 542 amino acids having protein tyrosine kinase activity. The kinase autophosphorylation sites have been mapped onto the primary amino acid sequence. Analysis of protein sequence databases have shown that the erb-B oncogene of avian erythroblastosis virus has acquired part of the avian EGF receptor gene. The hypothesis has been proposed that transformation by this virus is the result of expression of a truncated EGF receptor which lacks the majority of the EGF binding domain and delivers a continuous proliferation signal to transformed cells. We describe here the production of polyclonal and monoclonal antibodies to selected synthetic peptides from the EGF receptor and v-erb B sequences. Antisera to sequences encompassing the three major sites of autophosphorylation and the putative ATP binding site all recognize the native EGF receptor molecule. We have used these reagents to test our model of EGF receptor structure and v-erb B function.
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Amplification and overexpression of the EGF receptor gene in primary human glioblastomas. JOURNAL OF CELL SCIENCE. SUPPLEMENT 1985; 3:161-72. [PMID: 3011820 DOI: 10.1242/jcs.1985.supplement_3.16] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The expression of epidermal growth factor (EGF) receptor in brain tumours of glial origin was studied at the protein, mRNA and genomic levels. Four out of 10 glioblastomas that overexpress EGF receptor also have gene amplification. The amplified genes appear to be rearranged, generating an aberrant mRNA in at least one of these tumours. Such receptor defects may be relevant to tumorigenesis of human glioblastomas.
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Amplification, enhanced expression and possible rearrangement of EGF receptor gene in primary human brain tumours of glial origin. Nature 1985; 313:144-7. [PMID: 2981413 DOI: 10.1038/313144a0] [Citation(s) in RCA: 1210] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Epidermal growth factor (EGF), through interaction with specific cell surface receptors, generates a pleiotropic response that, by a poorly defined mechanism, can induce proliferation of target cells. Subversion of the EGF mitogenic signal through expression of a truncated receptor may be involved in transformation by the avian erythroblastosis virus (AEV) oncogene v-erb-B, suggesting that similar EGF receptor defects may be found in human neoplasias. Overexpression of EGF receptors has been reported on the epidermoid carcinoma cell line A431, in various primary brain tumours and in squamous carcinomas. In A431 cells the receptor gene is amplified. Here we show that 4 of 10 primary brain tumours of glial origin which express levels of EGF receptors that are higher than normal also have amplified EGF receptor genes. Amplified receptor genes were not detected in the other brain tumours examined. Further analysis of EGF receptor defects may show that such altered expression and amplification is a particular feature of certain human tumours.
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Platelet-derived growth factor is structurally related to the putative transforming protein p28sis of simian sarcoma virus. Nature 1983; 304:35-9. [PMID: 6306471 DOI: 10.1038/304035a0] [Citation(s) in RCA: 1370] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A partial amino acid sequence of human platelet-derived growth factor, the major mitogen in serum for cells of mesenchymal origin, has been determined. A region of 104 contiguous amino acids shows virtual identity with the predicted sequence of p28sis, the putative transforming protein of simian sarcoma virus (SSV). This similarity suggests a mechanism for transformation by SSV and other agents, involving expression of growth factors.
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