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Lester BM, Tronick E, Nestler E, Abel T, Kosofsky B, Kuzawa CW, Marsit CJ, Maze I, Meaney MJ, Monteggia LM, Reul JMHM, Skuse DH, Sweatt JD, Wood MA. Behavioral epigenetics. Ann N Y Acad Sci 2011; 1226:14-33. [PMID: 21615751 DOI: 10.1111/j.1749-6632.2011.06037.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Sponsored by the New York Academy of Sciences, the Warren Alpert Medical School of Brown University and the University of Massachusetts Boston, "Behavioral Epigenetics" was held on October 29-30, 2010 at the University of Massachusetts Boston Campus Center, Boston, Massachusetts. This meeting featured speakers and panel discussions exploring the emerging field of behavioral epigenetics, from basic biochemical and cellular mechanisms to the epigenetic modulation of normative development, developmental disorders, and psychopathology. This report provides an overview of the research presented by leading scientists and lively discussion about the future of investigation at the behavioral epigenetic level.
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McQuown SC, Wood MA. HDAC3 and the molecular brake pad hypothesis. Neurobiol Learn Mem 2011; 96:27-34. [PMID: 21521655 DOI: 10.1016/j.nlm.2011.04.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 03/25/2011] [Accepted: 04/08/2011] [Indexed: 12/26/2022]
Abstract
Successful transcription of specific genes required for long-term memory processes involves the orchestrated effort of not only transcription factors, but also very specific enzymatic protein complexes that modify chromatin structure. Chromatin modification has been identified as a pivotal molecular mechanism underlying certain forms of synaptic plasticity and memory. The best-studied form of chromatin modification in the learning and memory field is histone acetylation, which is regulated by histone acetyltransferases and histone deacetylases (HDACs). HDAC inhibitors have been shown to strongly enhance long-term memory processes, and recent work has aimed to identify contributions of individual HDACs. In this review, we focus on HDAC3 and discuss its recently defined role as a negative regulator of long-term memory formation. HDAC3 is part of a corepressor complex and has direct interactions with Class II HDACs that may be important for its molecular and behavioral consequences. And last, we propose the "molecular brake pad" hypothesis of HDAC function. The HDACs and associated corepressor complexes may function in neurons, in part, as "molecular brake pads." HDACs are localized to promoters of active genes and act as a persistent clamp that requires strong activity-dependent signaling to temporarily release these complexes (or brake pads) to activate gene expression required for long-term memory formation. Thus, HDAC inhibition removes the "molecular brake pads" constraining the processes necessary for long-term memory and results in strong, persistent memory formation.
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Reolon GK, Maurmann N, Werenicz A, Garcia VA, Schröder N, Wood MA, Roesler R. Posttraining systemic administration of the histone deacetylase inhibitor sodium butyrate ameliorates aging-related memory decline in rats. Behav Brain Res 2011; 221:329-32. [PMID: 21421011 DOI: 10.1016/j.bbr.2011.03.033] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/11/2011] [Accepted: 03/13/2011] [Indexed: 12/15/2022]
Abstract
Here we show that a systemic injection of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) ameliorated an aging-associated deficit in object recognition memory in rats when the injection was given immediately, but not 6h after training. NaB had no effect in younger rats with normal memory retention. The results indicate that HDACis can ameliorate aging-related memory impairments by influencing the early consolidation phase of memory formation.
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Haettig J, Stefanko DP, Multani ML, Figueroa DX, McQuown SC, Wood MA. HDAC inhibition modulates hippocampus-dependent long-term memory for object location in a CBP-dependent manner. Learn Mem 2011; 18:71-9. [PMID: 21224411 DOI: 10.1101/lm.1986911] [Citation(s) in RCA: 169] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Transcription of genes required for long-term memory not only involves transcription factors, but also enzymatic protein complexes that modify chromatin structure. Chromatin-modifying enzymes, such as the histone acetyltransferase (HAT) CREB (cyclic-AMP response element binding) binding protein (CBP), are pivotal for the transcriptional regulation required for long-term memory. Several studies have shown that CBP and histone acetylation are necessary for hippocampus-dependent long-term memory and hippocampal long-term potentiation (LTP). Importantly, every genetically modified Cbp mutant mouse exhibits long-term memory impairments in object recognition. However, the role of the hippocampus in object recognition is controversial. To better understand how chromatin-modifying enzymes modulate long-term memory for object recognition, we first examined the role of the hippocampus in retrieval of long-term memory for object recognition or object location. Muscimol inactivation of the dorsal hippocampus prior to retrieval had no effect on long-term memory for object recognition, but completely blocked long-term memory for object location. This was consistent with experiments showing that muscimol inactivation of the hippocampus had no effect on long-term memory for the object itself, supporting the idea that the hippocampus encodes spatial information about an object (such as location or context), whereas cortical areas (such as the perirhinal or insular cortex) encode information about the object itself. Using location-dependent object recognition tasks that engage the hippocampus, we demonstrate that CBP is essential for the modulation of long-term memory via HDAC inhibition. Together, these results indicate that HDAC inhibition modulates memory in the hippocampus via CBP and that different brain regions utilize different chromatin-modifying enzymes to regulate learning and memory.
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Roozendaal B, Hernandez A, Cabrera SM, Hagewoud R, Malvaez M, Stefanko DP, Haettig J, Wood MA. Membrane-associated glucocorticoid activity is necessary for modulation of long-term memory via chromatin modification. J Neurosci 2010; 30:5037-46. [PMID: 20371824 PMCID: PMC2861482 DOI: 10.1523/jneurosci.5717-09.2010] [Citation(s) in RCA: 193] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/13/2010] [Accepted: 02/25/2010] [Indexed: 01/31/2023] Open
Abstract
Glucocorticoid hormones enhance the consolidation of long-term memory of emotionally arousing training experiences. This memory enhancement requires activation of the cAMP-dependent kinase pathway and the subsequent phosphorylation of cAMP response-element binding (CREB) protein. Here, we demonstrate that glucocorticoids enhance the consolidation of hippocampus-dependent and hippocampus-independent aspects of object recognition memory via chromatin modification. More specifically, systemic corticosterone increases histone acetylation, a form of chromatin modification, in both the hippocampus and insular cortex following training on an object recognition task. This led us to examine whether increasing histone acetylation via histone deacetylase (HDAC) inhibition enhances memory in a manner similar to corticosterone. We found a double dissociation between posttraining HDAC inhibitor infusion into the insular cortex and hippocampus on the enhancement of object recognition and object location memory, respectively. In determining the molecular pathway upstream of glucocorticoids' effects on chromatin modification, we found that activation of membrane-associated glucocorticoid receptors (GRs) and the subsequent interaction between phospho-CREB and CREB-binding protein (CBP) appear to be necessary for glucocorticoids to enhance memory consolidation via chromatin modification. In contrast, mineralocorticoid receptors (MRs) do not appear to be involved. The findings also indicate that glucocorticoid activity has differential influences on hippocampus-dependent and hippocampus-independent components of memory for objects.
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Abstract
Substance use disorder is a chronic condition of compulsive drug seeking and use that is mediated by stable changes in central reward pathways. Repeated use of abused drugs causes persistent alterations in gene expression responsible for the long-term behavioral and structural changes. Recently, it has been suggested that epigenetic mechanisms are responsible in part for these drug-induced changes in gene expression. One of the alluring aspects of epigenetic regulation of gene expression is that epigenetic mechanisms may provide transient and potentially stable conditions that in turn may ultimately participate in the molecular mechanisms required for neuronal changes subserving long-lasting changes in behavior. This review describes epigenetic mechanisms of gene regulation and then discusses the emerging role of epigenetics in drug-induced plasticity and behavior. Understanding these mechanisms that establish and maintain drug-dependent plasticity changes may lead to deeper understanding of substance use disorders as well as novel approaches to treatment.
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Malvaez M, Sanchis-Segura C, Vo D, Lattal KM, Wood MA. Modulation of chromatin modification facilitates extinction of cocaine-induced conditioned place preference. Biol Psychiatry 2010; 67:36-43. [PMID: 19765687 PMCID: PMC2795056 DOI: 10.1016/j.biopsych.2009.07.032] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 07/03/2009] [Accepted: 07/26/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND Recent evidence suggests that epigenetic mechanisms have an important role in the development of addictive behavior. However, little is known about the role of epigenetic mechanisms in the extinction of drug-induced behavioral changes. In this study, we examined the ability of histone deacetylase (HDAC) inhibitors to facilitate extinction and attenuate reinstatement of cocaine-induced conditioned place preference (CPP). METHODS C57BL/6 mice were subject to cocaine-induced CPP using 20 mg/kg dose. To facilitate extinction, mice were administered an HDAC inhibitor following nonreinforced exposure to the conditioned context. To measure persistence, mice were subject to a reinstatement test using 10 mg/kg dose of cocaine. RESULTS We demonstrate that HDAC inhibition during extinction consolidation can facilitate extinction of cocaine-induced CPP. Animals treated with an HDAC inhibitor extinguished cocaine-induced CPP both more quickly and to a greater extent than did vehicle-treated animals. We also show that the extinction of cocaine seeking via HDAC inhibition modulates extinction learning such that reinstatement behavior is significantly attenuated. Acetylation of histone H3 in the nucleus accumbens following extinction was increased by HDAC inhibition. CONCLUSIONS This study provides the first evidence that modulation of chromatin modification can facilitate extinction and prevent reinstatement of drug-induced behavioral changes. These findings provide a potential novel approach to the development of treatments that facilitate extinction of drug-seeking behavior.
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Gassei K, Ehmcke J, Wood MA, Walker WH, Schlatt S. Immature rat seminiferous tubules reconstructed in vitro express markers of Sertoli cell maturation after xenografting into nude mouse hosts. Mol Hum Reprod 2009; 16:97-110. [PMID: 19770206 DOI: 10.1093/molehr/gap081] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sertoli cells undergo a maturation process during post-natal testicular development that leads to the adult-type Sertoli cell, which is required for spermatogenesis. Understanding Sertoli cell maturation is therefore necessary to gain insight into the underlying causes of impaired spermatogenesis and male infertility. The present study characterized the cellular and molecular differentiation of Sertoli cells in a xenograft model of mammalian testicular development. Immature rat Sertoli cells were cultured in a three-dimensional culture system to allow the formation of cord-like structures. The in vitro Sertoli cell cultures were then grafted into nude mice. Sertoli cell proliferation, morphological differentiation and mRNA expression of Sertoli cell maturation markers were evaluated in xenografts. Sertoli cell proliferation significantly decreased between 1 and 4 weeks (6.7 +/- 0.9 versus 1.2+/- 0.1%, P < 0.001), and was maintained at low levels thereafter. Sertoli cell cord-like structures significantly decreased between 1 and 4 weeks (59.6 versus 21%, P < 0.05), whereas Sertoli cell tubules were more frequently observed after 4 weeks (13.3 versus 73.1%, P < 0.05). Furthermore, expression of androgen binding protein, transferrin and follicle stimulating hormone receptor, markers for mature Sertoli cells, was detected after 1 week of grafting and increased significantly thereafter. We conclude from these results that rat Sertoli cells continue maturation after xenografting to the physiological environment of a host. This model of in vitro tubule formation will be helpful in future investigations addressing testicular maturation in the mammalian testis.
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Malvaez M, Barrett RM, Wood MA, Sanchis-Segura C. Epigenetic mechanisms underlying extinction of memory and drug-seeking behavior. Mamm Genome 2009; 20:612-23. [PMID: 19789849 PMCID: PMC3157916 DOI: 10.1007/s00335-009-9224-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Accepted: 08/25/2009] [Indexed: 12/28/2022]
Abstract
An increasing body of evidence shows that structural modifications of chromatin, the DNA-protein complex that packages genomic DNA, do not only participate in maintaining cellular memory (e.g., cell fate), but they may also underlie the strengthening and maintenance of synaptic connections required for long-term changes in behavior. Accordingly, epigenetics has become a central topic in several neurobiology fields such as memory, drug addiction, and several psychiatric and mental disorders. This interest is justified as dynamic chromatin modifications may provide not only transient but also stable (or even potentially permanent) epigenetic marks to facilitate, maintain, or block transcriptional processes, which in turn may participate in the molecular neural adaptations underlying behavioral changes. Through epigenetic mechanisms the genome may be indexed in response to environmental signals, resulting in specific neural modifications that largely determine the future behavior of an organism. In this review we discuss recent advances in our understanding of how epigenetic mechanisms contribute to the formation of long-term memory and drug-seeking behavior and potentially how to apply that knowledge to the extinction of memory and drug-seeking behavior.
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Wood MA, Panciera DL, Berry SH, Monroe WE, Refsal KR. Influence of isoflurane general anesthesia or anesthesia and surgery on thyroid function tests in dogs. J Vet Intern Med 2009; 23:7-15. [PMID: 19138380 DOI: 10.1111/j.1939-1676.2008.00216.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Anesthesia and surgery affect thyroid function tests in humans but have not been studied in dogs. HYPOTHESIS Anesthesia and anesthesia with surgery will affect thyroid function tests in dogs. ANIMALS Fifteen euthyroid dogs. METHODS Prospective, controlled, interventional study. Dogs were assigned to one of 3 groups: control, general anesthesia, and general anesthesia plus abdominal exploratory surgery. Dogs in the anesthesia and surgery groups were premedicated with acepromazine and morphine, induced with propofol, and maintained on isoflurane. Samples for measurement of serum thyroxine (T4), free T4 (fT4) by equilibrium dialysis, triiodothyronine (T3), reverse T3 (rT3), and thyroid-stimulating hormone concentrations were collected from each dog immediately before premedication, at multiple times during anesthesia, surgery, 4, 8, 12, 24, 36, and 48 hours after anesthesia, once daily for an additional 5 days, and once 14 days after anesthesia. Sampling was performed at identical times in the control group. RESULTS Serum T4 decreased significantly from baseline in the surgery and anesthesia groups compared with the control group at 0.33 (P= 0.043) and 1 hour (P= 0.018), and 2 (P= 0.031) and 4 hours (P= 0.037), respectively, then increased significantly in the surgery group compared with the control group at 24 hours (P= 0.005). Serum T3 decreased significantly from baseline in the anesthesia group compared with the control group at 1 hour (P= 0.034). Serum rT3 increased significantly from baseline in the surgery group compared with the control and anesthesia groups at 8 (P= 0.026) and 24 hours (P= 0.0001) and anesthesia group at 8, 12, 24, and 36 hours (P= 0.004, P= 0.016, P= 0.004, and P= 0.014, respectively). Serum fT4 increased significantly from baseline in the surgery group compared to the control at 24 hours (P= 0.006) and at day 7 (P= 0.037) and anesthesia group at 48 hours (P= 0.023). CONCLUSIONS AND CLINICAL IMPORTANCE Surgery and anesthesia have a significant effect on thyroid function tests in dogs.
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Pham J, Cabrera SM, Sanchis-Segura C, Wood MA. Automated scoring of fear-related behavior using EthoVision software. J Neurosci Methods 2008; 178:323-6. [PMID: 19150629 DOI: 10.1016/j.jneumeth.2008.12.021] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 12/16/2008] [Accepted: 12/18/2008] [Indexed: 10/21/2022]
Abstract
Fear conditioning is a frequently used paradigm for assessing learning and memory in rodents. Traditionally researchers have relied upon scoring of fear-related behavior by human observation, which can be difficult and subjective and thus vary among investigators. The goal of this study was to evaluate the ability of EthoVision tracking software (Noldus Information Technology Inc.) to reliably and accurately score fear-related behavior in mice. Specifically, we were interested in its ability to accurately track mice and score immobility as a fear-related behavior during contextual and cued fear conditioning. Contextual and cued fear conditioning were performed in modified PhenoTyper chambers (Noldus Information Technology Inc.) fitted with grid floors to deliver a scrambled foot shock. Our results demonstrate that we have identified parameters in EthoVision that can accurately track mice and be used for automated scoring of immobility that is nearly identical to scoring by human observation. Together, EthoVision software and the modified PhenoTyper chambers provide an excellent system for the reliable and accurate measurement of fear-related behavior in a high-throughput manner.
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Wood MA, Yang Y, Baas E, Meredith DO, Richards RG, Kuiper JH, El Haj AJ. Correlating cell morphology and osteoid mineralization relative to strain profile for bone tissue engineering applications. J R Soc Interface 2008; 5:899-907. [PMID: 18077245 PMCID: PMC2607462 DOI: 10.1098/rsif.2007.1265] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A number of bone tissue engineering strategies use porous three-dimensional scaffolds in combination with bioreactor regimes. The ability to understand cell behaviour relative to strain profile will allow for the effects of mechanical conditioning in bone tissue engineering to be realized and optimized. We have designed a model system to investigate the effects of strain profile on bone cell behaviour. This simplified model has been designed with a view to providing insight into the types of strain distribution occurring across a single pore of a scaffold subjected to perfusion-compression conditioning. Local strains were calculated at the surface of the pore model using finite-element analysis. Scanning electron microscopy was used in secondary electron mode to identify cell morphology within the pore relative to local strains, while backscattered electron detection in combination with X-ray microanalysis was used to identify calcium deposition. Morphology was altered according to the level of strain experienced by bone cells, where cells subjected to compressive strains (up to 0.61%) appeared extremely rounded while those experiencing zero and tensile strain (up to 0.81%) were well spread. Osteoid mineralization was similarly shown to be dose dependent with respect to substrate strain within the pore model, with the highest level of calcium deposition identified in the intermediate zones of tension/compression.
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Sedaghat H, Wood MA, Cain JW, Cheng CK, Baumgarten CM, Chan DM. Complex temporal patterns of spontaneous initiation and termination of reentry in a loop of cardiac tissue. J Theor Biol 2008; 254:14-26. [PMID: 18571676 DOI: 10.1016/j.jtbi.2008.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 03/27/2008] [Accepted: 05/02/2008] [Indexed: 11/17/2022]
Abstract
A two-component model is developed consisting of a discrete loop of cardiac cells that circulates action potentials as well as a pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of conduction velocity are given via experimentally measured functions. The dynamics of circulating pulses and the pacer's action are regulated by two threshold relations. Patterns of spontaneous initiations and terminations of reentry (SITR) generated by this system are studied through numerical simulations and analytical observations. These patterns can be regular or irregular; causes of irregularities are identified as the threshold bistability (T-bistability) of reentrant circulation and in some cases, also phase-resetting interactions with the pacer.
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Barrett RM, Wood MA. Beyond transcription factors: the role of chromatin modifying enzymes in regulating transcription required for memory. Learn Mem 2008; 15:460-7. [PMID: 18583646 DOI: 10.1101/lm.917508] [Citation(s) in RCA: 199] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
One of the alluring aspects of examining chromatin modifications in the role of modulating transcription required for long-term memory processes is that these modifications may provide transient and potentially stable epigenetic marks in the service of activating and/or maintaining transcriptional processes. These, in turn, may ultimately participate in the molecular mechanisms required for neuronal changes subserving long-lasting changes in behavior. As an epigenetic mechanism of transcriptional control, chromatin modification has been shown to participate in maintaining cellular memory (e.g., cell fate) and may underlie the strengthening and maintenance of synaptic connections required for long-term changes in behavior. Epigenetics has become central to several fields of neurobiology, where researchers have found that regulation of chromatin modification has a significant role in epilepsy, drug addiction, depression, neurodegenerative diseases, and memory. In this review, we will discuss the role of chromatin modifying enzymes in memory processes, as well as how recent studies in yeast genetics and cancer biology may impact the way we think about how chromatin modification and chromatin remodeling regulate neuronal function.
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Lattal KM, Barrett R, Wood MA. Systemic or intrahippocampal delivery of histone deacetylase inhibitors facilitates fear extinction. Behav Neurosci 2007; 121:1125-31. [PMID: 17907845 PMCID: PMC7247429 DOI: 10.1037/0735-7044.121.5.1125] [Citation(s) in RCA: 190] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Several recent studies have shown that chromatin, the DNA-protein complex that packages genomic DNA, has an important function in learning and memory. Dynamic chromatin modification via histone deacetylase (HDAC) inhibitors and histone acetyltransferases may enhance hippocampal synaptic plasticity and hippocampus-dependent memory. Little is known about the effects of HDAC inhibitors on extinction, a learning process through which the ability of a previously conditioned stimulus, such as a conditioning context, to evoke a conditioned response is diminished. The authors demonstrate that administration of the HDAC inhibitors sodium butyrate (NaB) systemically or trichostatin A (TSA) intrahippocampally prior to a brief (3-min) contextual extinction session causes context-evoked fear to decrease to levels observed with a long (24-min) extinction session. These results suggest that HDAC inhibitors may enhance learning during extinction and are consistent with other studies demonstrating a role for the hippocampus in contextual extinction. Molecular and behavioral mechanisms through which this enhanced extinction effect may occur are discussed.
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Or-Rashid MM, Kramer JKG, Wood MA, McBride BW. Supplemental algal meal alters the ruminal trans-18:1 fatty acid and conjugated linoleic acid composition in cattle. J Anim Sci 2007; 86:187-96. [PMID: 17940158 DOI: 10.2527/jas.2007-0085] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effects of dietary algal supplementation, a source of docosahexaenoic acid, on the fatty acid profile of rumen lipids in cattle were evaluated, with special emphasis on CLA and trans fatty acids produced by rumen microbes. A diet based on corn silage was fed with supplements containing the following: 1) no algal meal and fed at 2.1 kg of DM/d (control), 2) algal meal and fed at 1.1 kg of DM/d (low algal meal), 3) algal meal and fed at 2.1 kg of DM/d (medium algal meal), and 4) algal meal and fed at 4.2 kg of DM/d (high algal meal). A modified lipid extraction procedure was developed to analyze the lipid changes in rumen fluid. The percentage of stearic acid (18:0) in rumen fluid was decreased by algal meal supplementation (P < 0.001) compared with control and was linearly dependent on the level of algal meal supplementation (P = 0.005). Total trans-18:1 in rumen fluid of cattle fed the control diet was 19% of total fatty acids. Addition of algal meal increased (P < 0.001) total trans-18:1 up to 43%, mostly due to 18:1 trans-10 that increased (P = 0.002) to 29.5% of total rumen fatty acids. This increase in 18:1 trans-10 seems to suggest a change in the rumen microbial population. Vaccenic acid (18:1 trans-11) increased quadratically (P = 0.005) with increasing level of algal meal supplementation in the diets. The total CLA content was low in the control (<0.9%) and increased with dietary algal meal addition, although not significantly; the greatest level was 1.5% with the medium algal meal diet. The increase of rumenic acid (cis-9, trans-11 CLA) was quadratic (P = 0.05) with algal meal supplementation, whereas trans-10, cis-12 CLA increased linearly with increased level of algal meal from 0.08 to 0.13% (P = 0.03). The ratio of trans-11 (cis-9, trans-11 CLA + 18:1 trans-11) to trans-10 (trans-10, cis-12 CLA + 18:1 trans-10) decreased from 2.45 to 0.77, 0.87, and 0.21 for the control, low algal meal, medium algal meal, and high algal meal diets, respectively. The content of docosahexaenoic acid in rumen fluid increased (P = 0.002) from 0.3 to 1.4% of total fatty acids with increasing level of algal meal supplementation in the diets. Our results suggest that algal meal inhibits the reduction of trans-18:1 to 18:0, giving rise to the high trans-18:1 content. In conclusion, algal meal could be used to increase the concentration in rumen contents of trans-18:1 isomers that serve as precursors for CLA biosynthesis in the tissues of ruminants.
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Oliveira AM, Wood MA, McDonough CB, Abel T. Transgenic mice expressing an inhibitory truncated form of p300 exhibit long-term memory deficits. Learn Mem 2007; 14:564-72. [PMID: 17761541 PMCID: PMC1994075 DOI: 10.1101/lm.656907] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The formation of many forms of long-term memory requires several molecular mechanisms including regulation of gene expression. The mechanisms directing transcription require not only activation of individual transcription factors but also recruitment of transcriptional coactivators. CBP and p300 are transcriptional coactivators that interact with a large number of transcription factors and regulate transcription through multiple mechanisms, including an intrinsic histone acetyltransferase (HAT) activity. HAT activity mediates acetylation of lysine residues on the amino-terminal tails of histone proteins, thereby increasing DNA accessibility for transcription factors to activate gene expression. CBP has been shown to play an important role in long-term memory formation. We have investigated whether p300 is also required for certain forms of memory. p300 shares a high degree of homology with CBP and has been shown to interact with transcription factors known to be critical for long-term memory formation. Here we demonstrate that conditional transgenic mice expressing an inhibitory truncated form of p300 (p300Delta1), which lacks the carboxy-terminal HAT and activation domains, have impaired long-term recognition memory and contextual fear memory. Thus, our study demonstrates that p300 is required for certain forms of memory and that the HAT and carboxy-terminal domains play a critical role.
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Vecsey CG, Hawk JD, Lattal KM, Stein JM, Fabian SA, Attner MA, Cabrera SM, McDonough CB, Brindle PK, Abel T, Wood MA. Histone deacetylase inhibitors enhance memory and synaptic plasticity via CREB:CBP-dependent transcriptional activation. J Neurosci 2007; 27:6128-40. [PMID: 17553985 PMCID: PMC2925045 DOI: 10.1523/jneurosci.0296-07.2007] [Citation(s) in RCA: 609] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Histone deacetylase (HDAC) inhibitors increase histone acetylation and enhance both memory and synaptic plasticity. The current model for the action of HDAC inhibitors assumes that they alter gene expression globally and thus affect memory processes in a nonspecific manner. Here, we show that the enhancement of hippocampus-dependent memory and hippocampal synaptic plasticity by HDAC inhibitors is mediated by the transcription factor cAMP response element-binding protein (CREB) and the recruitment of the transcriptional coactivator and histone acetyltransferase CREB-binding protein (CBP) via the CREB-binding domain of CBP. Furthermore, we show that the HDAC inhibitor trichostatin A does not globally alter gene expression but instead increases the expression of specific genes during memory consolidation. Our results suggest that HDAC inhibitors enhance memory processes by the activation of key genes regulated by the CREB:CBP transcriptional complex.
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Wood MA. Colloidal lithography and current fabrication techniques producing in-plane nanotopography for biological applications. J R Soc Interface 2007; 4:1-17. [PMID: 17015295 PMCID: PMC2358954 DOI: 10.1098/rsif.2006.0149] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Substrate topography plays a vital role in cell and tissue structure and function in situ, where nanometric features, for example, the detail on single collagen fibrils, influence cell behaviour and resultant tissue formation. In vitro investigations demonstrate that nanotopography can be used to control cell reactions to a material surface, indicating its potential application in tissue engineering and implant fabrication. Developments in the catalyst, optical, medical and electronics industries have resulted in the production of nanopatterned surfaces using a variety of methods. The general protocols for nanomanufacturing require high resolution and low cost for fabricating devices. With respect to biological investigations, nanotopographies should occur across a large surface area (ensuring repeatability of experiments and patterning of implant surfaces), be reproducible (allowing for consistency in experiments), and preferably, accessible (limiting the requirement for specialist equipment). Colloidal lithography techniques fit these criteria, where nanoparticles can be utilized in combination with a functionalized substrate to produce in-plane nanotopographies. Subsequent lithographic processing of colloidal substrates utilizing, for example, reactive ion etching allows the production of modified colloidal-derived nanotopographies. In addition to two-dimensional in-plane nanofabrication, functionalized structures can be dip coated in colloidal sols, imparting nanotopographical cues to cells within a three-dimensional environment.
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Yu J, Wang P, Ming L, Wood MA, Zhang L. SMAC/Diablo mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events. Oncogene 2007; 26:4189-98. [PMID: 17237824 DOI: 10.1038/sj.onc.1210196] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
p53-upregulated modulator of apoptosis (PUMA) is a BH3-only Bcl-2 family protein and an essential mediator of DNA damage-induced apoptosis. PUMA is localized in the mitochondria and induces apoptosis through the mitochondrial pathway. However, the mechanisms of PUMA-induced apoptosis remain unclear. In this study, we found that second mitochondria-derived activator of caspase (SMAC)/Diablo, a mitochondrial apoptogenic protein, mediates the proapoptotic function of PUMA by regulating PUMA-induced mitochondrial events. SMAC is consistently released into the cytosol in colon cancer cells undergoing PUMA-induced apoptosis. In SMAC-deficient cells, execution of PUMA-induced apoptosis is abrogated, in company with decreases in caspase activation, cytosolic release of cytochrome c and collapse of mitochondrial membrane potential. Reconstituting SMAC expression restored these events in the SMAC-deficient cells. Furthermore, SMAC and agents that mimic the inhibitor of apoptosis proteins (IAPs) inhibition function of SMAC significantly sensitize cells to PUMA-induced apoptosis. These results demonstrate an important role of SMAC in executing DNA damage-induced and PUMA-mediated apoptosis and suggest that SMAC participates in a feedback amplification loop to promote cytochrome c release and other mitochondrial events in apoptosis.
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96
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Wood MA, Attner MA, Oliveira AM, Brindle PK, Abel T. A transcription factor-binding domain of the coactivator CBP is essential for long-term memory and the expression of specific target genes. Learn Mem 2006; 13:609-17. [PMID: 16980541 PMCID: PMC1783615 DOI: 10.1101/lm.213906] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with numerous transcription factors and contains multiple functional domains. Currently, it is not known which transcription factor-binding domain of CBP is essential for memory storage. Using mice that carry inactivating mutations in the CREB-binding (KIX) domain of the coactivator CBP (CBPKIX/KIX mice), we show that the KIX domain is required for long-term memory storage. These results are the first to identify an in vivo function for the KIX domain of CBP in the brain, and they suggest that KIX-interacting transcription factors recruit CBP histone acetyltransferase activity during long-term memory storage. One such KIX-interacting factor is the transcription factor CREB. Using quantitative real-time RT-PCR, we find that the expression of specific CREB target genes is reduced in the hippocampi of CBPKIX/KIX mice during memory consolidation. The recruitment of the transcriptional coactivator CBP via the KIX domain thus imparts target gene-dependent selectivity to CREB-driven transcriptional regulation, thereby activating genes required for the long-term storage of hippocampus-dependent memory.
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97
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Wood MA, Hawk JD, Abel T. Combinatorial chromatin modifications and memory storage: a code for memory? Learn Mem 2006; 13:241-4. [PMID: 16741277 PMCID: PMC2909467 DOI: 10.1101/lm.278206] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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98
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Wood MA, Hughes S, Yang Y, El Haj AJ. Characterizing the efficacy of calcium channel agonist-release strategies for bone tissue engineering applications. J Control Release 2006; 112:96-102. [PMID: 16527370 DOI: 10.1016/j.jconrel.2006.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 01/20/2006] [Accepted: 01/25/2006] [Indexed: 10/24/2022]
Abstract
We have previously reported on the use of Bay K8644-release strategies in combination with perfusion-compression bioreactor systems for up regulating bone formation in three-dimensional PLLA scaffolds. Here we report on the analysis of Bay activity following its release from our PLLA scaffolds over the culture period imposed in our tissue engineering protocol using UV spectroscopy in combination with whole cell patch clamping techniques. Bay was released continually from scaffolds within the physiological range required for agonist activity (1-10 microM). Patch clamping allowed for the effects of Bay released from scaffolds to be monitored directly with respect to osteoblast electrophysiology. A characteristic shift in the current-voltage (I-V) relationship of L-type VOCC currents was observed in rat osteoblast sarcoma (ROS) cells patched in a solution with Bay released from scaffolds following 14 and 28 days incubation, with statistically significant differences observed in peak currents compared to non-Bay controls. An increase in the magnitude of the peak inward currents was also noted. The electrophysiological response of osteoblasts in the presence of Bay released from scaffolds demonstrates that the released Bay is stable and maintains its bioactivity following culture of up to 28 days.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/chemistry
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Biocompatible Materials/chemistry
- Bioreactors
- Calcium Channel Agonists/chemistry
- Calcium Channel Agonists/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Cell Line, Tumor
- Delayed-Action Preparations
- Drug Stability
- Lactic Acid/chemistry
- Membrane Potentials
- Osteoblasts/drug effects
- Osteoblasts/metabolism
- Osteogenesis
- Polyesters
- Polymers/chemistry
- Porosity
- Rats
- Solubility
- Time Factors
- Tissue Engineering/instrumentation
- Tissue Engineering/methods
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99
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Keeley MB, Wood MA, Isiegas C, Stein J, Hellman K, Hannenhalli S, Abel T. Differential transcriptional response to nonassociative and associative components of classical fear conditioning in the amygdala and hippocampus. Learn Mem 2006; 13:135-42. [PMID: 16547164 PMCID: PMC1409829 DOI: 10.1101/lm.86906] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Classical fear conditioning requires the recognition of conditioned stimuli (CS) and the association of the CS with an aversive stimulus. We used Affymetrix oligonucleotide microarrays to characterize changes in gene expression compared to naive mice in both the amygdala and the hippocampus 30 min after classical fear conditioning and 30 min after exposure to the CS in the absence of an aversive stimulus. We found that in the hippocampus, levels of gene regulation induced by classical fear conditioning were not significantly greater than those induced by CS alone, whereas in the amygdala, classical fear conditioning did induce significantly greater levels of gene regulation compared to the CS. Computational studies suggest that transcriptional changes in the hippocampus and amygdala are mediated by large and overlapping but distinct combinations of molecular events. Our results demonstrate that an increase in gene regulation in the amygdala was partially correlated to associative learning and partially correlated to nonassociative components of the task, while gene regulation in the hippocampus was correlated to nonassociative components of classical fear conditioning, including configural learning.
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100
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Oliveira AMM, Abel T, Brindle PK, Wood MA. Differential role for CBP and p300 CREB-binding domain in motor skill learning. Behav Neurosci 2006; 120:724-9. [PMID: 16768624 DOI: 10.1037/0735-7044.120.3.724] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cyclic adenosine monophosphate response element binding protein (CREB) binding protein (CBP) and E1A binding protein (p300) are highly homologous transcriptional coactivators with histone acetyltransferase activity. Although CBP and p300 have unique functions in vivo during embryogenesis and hematopoiesis, their functions within the nervous system remain poorly understood. The authors demonstrate that these coactivators have differential roles in motor skill learning. Mice with a mutation in the CREB-binding (KIX) domain of CBP exhibited motor learning deficits. However, mice with the analogous mutation in the KIX domain of p300 showed normal motor learning. Further, CREB knock-out mice exhibited a motor learning deficit similar to that of CBP-KIX mutant mice. These results suggest that the CREB-CBP interaction is more limiting or critical than the CREB-p300 interaction for motor skill learning. Thus, CBP and p300 are genetically distinct at the behavioral level.
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