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Huang WT, Weng CF. Roles of hepatocyte nuclear factors (HNF) in the regulation of reproduction in teleosts. JOURNAL OF FISH BIOLOGY 2010; 76:225-239. [PMID: 20738706 DOI: 10.1111/j.1095-8649.2009.02480.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hepatocyte nuclear factor (HNF) families are composed of liver-enriched transcription factors and upstream regulators of many liver-specific genes. HNF are involved in liver-specific gene expression, metabolism, development, cell growth and many cellular functions in the body. HNF genes can be activated or influenced by several hormones and insulin-like growth factors (IGF), and different combinations of the four HNF factors form a network in controlling the expression of liver-specific or liver-enriched genes. The functions of these factors and their interactions within the gonads of bony fishes, however, are not well understood, and the related literature is scant. Recently, several members of the HNF families have been detected in teleost gonads together with their downstream genes (IGF-I and IGF-II), suggesting that these HNF could be upregulated in vitro by steroid hormones. Thus, the hormone-HNF-IGF-gonad interaction may be an alternative axis in the reproductive mechanism that acts in concert with the conventional hypothalamus-pituitary-gonad pathway. This may help the early development and maturation of the gonad or gamete, sexual maturity or reversion and spawning-regulating mechanisms among fishes to be understood.
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Affiliation(s)
- W-T Huang
- Department of Molecular Biotechnology, Da-Yeh University, Chang-Hua 515, Taiwan
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152
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Matthews SG, Phillips DIW. Minireview: transgenerational inheritance of the stress response: a new frontier in stress research. Endocrinology 2010; 151:7-13. [PMID: 19887563 DOI: 10.1210/en.2009-0916] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
It is well established in animal models that the prenatal environment can have a major impact on stress axis function throughout life. These changes can predispose to various metabolic, cardiovascular, and neurobiological pathophysiologies. Emerging evidence indicates that the same programming effects occur in humans. It is now becoming clear that the pathophysiological effects are not confined to the first-generation offspring and that there is transgenerational memory of fetal experience that can extend across multiple generations. The complex mechanisms by which transgenerational transmission of stress responsiveness occur are rapidly becoming a focus of investigation. Understanding these fundamental biological processes will allow for development of intervention strategies that prevent or reverse adverse programming of the stress response.
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Affiliation(s)
- Stephen G Matthews
- Department of Physiology, Faculty of Medicine, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario, Canada.
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153
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Mesquita AR, Wegerich Y, Patchev AV, Oliveira M, Leão P, Sousa N, Almeida OFX. Glucocorticoids and neuro- and behavioural development. Semin Fetal Neonatal Med 2009; 14:130-5. [PMID: 19084485 DOI: 10.1016/j.siny.2008.11.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Epidemiological evidence links exposure to stress hormones during fetal or early postnatal development with lifetime prevalence of cardiac, metabolic, auto-immune, neurological and psychiatric disorders. This has led to the concept of 'developmental programming through stress'. Importantly, these effects (specifically, hypertension, hyperglycaemia and neurodevelopmental and behavioural abnormalities) can be reproduced by exposure to high glucocorticoid levels, indicating a crucial role of glucocorticoids in their causation. However, there can be important differences in outcome, depending on the exact time of exposure, as well as duration and receptor selectivity of the glucocorticoid applied. The mechanisms underlying programming by stress are still unclear but it appears that these environmental perturbations exploit epigenetic modifications of DNA and/or histones to induce stable modifications of gene expression. Programming of neuro- and behavioural development by glucocorticoids and stress are important determinants of lifetime health and should be a consideration when choosing treatments in obstetric and neonatal medicine.
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Affiliation(s)
- Ana Raquel Mesquita
- Life & Health Sciences Research Institute (ICVS), University of Minho, 4710-057 Braga, Portugal
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154
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155
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Atanasova S, Wieland E, Schlumbohm C, Korecka M, Shaw L, von Ahsen N, Fuchs E, Oellerich M, Armstrong V. Prenatal dexamethasone exposure in the common marmoset monkey enhances gene expression of antioxidant enzymes in the aorta of adult offspring. Stress 2009; 12:215-24. [PMID: 19005875 DOI: 10.1080/10253890802305075] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Human epidemiological studies have indicated that low birth weight associated with an adverse intrauterine environment is related to a greater incidence of cardiovascular disorders in later life. In the foetus, endogenous glucocorticoids generally increase if there is intrauterine nutrient deficiency. The consequent glucocorticoid hyperexposure has been hypothesised to cause in utero programming of atherogenic genes. We investigated the effect of oral treatment with the synthetic glucocorticoid dexamethasone during early or late pregnancy in marmoset monkeys on oxidative and antioxidant status in the offspring. Urinary concentrations of F(2)-isoprostanes were quantified as markers for in vivo oxidative stress. Expression of the mRNAs for the antioxidant enzymes cytosolic glutathione peroxidase (GPx-1), phospholipid hydroperoxide glutathione peroxidase (GPx-4), cytosolic Cu,Zn-superoxide dismutase (SOD1), mitochondrial Mn-superoxide dismutase (SOD2), glutathione reductase (GSR), modifier subunit of glutamate-cysteine ligase (GCLM) and catalase were determined in the aorta. Three groups of pregnant marmosets (10 animals per group) were treated orally for one week with vehicle, or with dexamethasone (5 mg/kg daily) during two gestation windows: early dexamethasone group, pregnancy day 42-48, and late dexamethasone group, pregnancy day 90-96. In one male sibling of each litter (10 males per group), aortas were taken at 2 years of age. In the late dexamethasone group a higher aortic mRNA expression for GPx-1 (p < 0.023), MnSOD (p < 0.016), GCLM (p < 0.019) and GSR (p < 0.014) in comparison to the controls was observed. Aortic expression in the early dexamethasone group was statistically significantly higher only for GSR mRNA (p < 0.038). No significant changes in urinary F(2)-isoprostane concentrations between controls, early and late dexamethasone groups at 2 years of age were observed. Hence, prenatal exposure to dexamethasone in the third trimester leads to increased mRNA expression of several aortic antioxidant enzymes in the offspring. This expression pattern was not temporally related to oxidative stress, and it may reflect in utero re-programming of aortic antioxidant gene expression during prenatal glucocorticoid exposure.
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Affiliation(s)
- S Atanasova
- Department of Clinical Chemistry, Georg-August University, Goettingen, Germany
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156
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Abstract
The cloning of animals from adult cells has demonstrated that the developmental state of adult cells can be reprogrammed into that of embryonic cells by uncharacterized factors within the oocyte. More recently, transcription factors have been identified that can induce pluripotency in somatic cells without the use of oocytes, generating induced pluripotent stem (iPS) cells. iPS cells provide a unique platform to dissect the molecular mechanisms that underlie epigenetic reprogramming. Moreover, iPS cells can teach us about principles of normal development and disease, and might ultimately facilitate the treatment of patients by custom-tailored cell therapy.
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Affiliation(s)
- Konrad Hochedlinger
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Boston, MA 02114, USA.
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157
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Abstract
PURPOSE OF REVIEW There is a growing body of evidence linking adverse events or exposures during early life and adult-onset diseases. After important epidemiological studies from many parts of the world, research now focuses on mechanisms of organ dysfunction and on refining the understanding of the interaction between common elements of adverse perinatal conditions, such as nutrition, oxidants, and toxins exposures. This review will focus on advances in our comprehension of developmental programming of hypertension. RECENT FINDINGS Recent studies have unraveled important mechanisms of oligonephronia and impaired renal function, altered vascular function and structure as well as sympathetic regulation of the cardiovascular system. Furthermore, interactions between prenatal insults and postnatal conditions are the subject of intensive research. Prematurity vs. intrauterine growth restriction modulate differently programming of high blood pressure. Along with antenatal exposure to glucocorticoids and imbalanced nutrition, a critical role for perinatal oxidative stress is emerging. SUMMARY While the complexity of the interactions between antenatal and postnatal influences on adult blood pressure is increasingly recognized, the importance of postnatal life in (positively) modulating developmental programming offers the hope of a critical window of opportunity to reverse programming and prevent or reduce related adult-onset diseases.
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Affiliation(s)
- Anne Monique Nuyt
- Department of Pediatrics, Research Center, CHU Sainte-Justine, Université de Montréal, Canada.
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158
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Greathouse KL, Cook JD, Lin K, Davis BJ, Berry TD, Bredfeldt TG, Walker CL. Identification of uterine leiomyoma genes developmentally reprogrammed by neonatal exposure to diethylstilbestrol. Reprod Sci 2009; 15:765-78. [PMID: 19017814 DOI: 10.1177/1933719108322440] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Environmental exposures during development can alter susceptibility later in life to adult diseases including uterine leiomyoma, a phenomenon termed developmental reprogramming. The goal of this study was to identify genes developmentally reprogrammed by diethylstilbestrol (DES) and aberrantly expressed in leiomyomas. Transcriptional profiling identified 171 genes differentially expressed in leiomyomas relative to normal myometrium, of which 6/18 genes with putative estrogen responsive elements and confirmed to be estrogen-responsive in neonatal uteri were reprogrammed by neonatal DES exposure. Calbindin D9k and Dio2, normally induced by estrogen, exhibited elevated expression in DES-exposed animals during both phases of the estrus cycle. Gdf10, Car8, Gria2, and Mmp3, genes normally repressed by estrogen, exhibited elevated expression in DES-exposed animals during the proliferative phase, when estrogen is highest. These data demonstrate that neonatal DES exposure causes reprogramming of estrogen-responsive genes expressed in uterine leiomyomas, leading to over-expression of these genes in the myometrium of exposed animals prior to the onset of tumorigenesis.
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Affiliation(s)
- K L Greathouse
- Department of Carcinogenesis, MD Anderson Cancer Center, Science Park Research Division, Smithville, Texas, USA
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159
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Chiam K, Tilley WD, Butler LM, Bianco-Miotto T. The dynamic and static modification of the epigenome by hormones: a role in the developmental origin of hormone related cancers. Biochim Biophys Acta Rev Cancer 2009; 1795:104-9. [PMID: 19166905 DOI: 10.1016/j.bbcan.2008.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 12/14/2008] [Accepted: 12/21/2008] [Indexed: 12/19/2022]
Abstract
There are numerous diseases associated with abnormal hormonal regulation and these include cancers of the breast and prostate. There is substantial evidence that early hormonal perturbations (in utero or during early development) are associated with increased disease susceptibility later in life. These perturbations may arise from exposure to environmental agents or endocrine disruptors which mimic hormones and disrupt normal hormonal signaling. Epigenetic alterations have often been proposed as the underlying mechanism by which early hormonal perturbations may give rise to disease in adulthood. Currently, there is minimal evidence to support a direct link between early hormonal perturbations and epigenetic modifications; or between epigenetic alterations and subsequent onset of cancer. Given that epigenetic modifications may play an important role in hormone-dependent cancers, it is essential to better understand the relationship between the hormonal environment and epigenetic modifications in both normal and disease states. In this review, we highlight several important studies which support the hypothesis that: hormonal perturbations early in life may result in epigenetic changes that may modify hormone receptor function, thereby contributing to an increased risk of developing hormone-related cancers.
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Affiliation(s)
- Karen Chiam
- Dame Roma Mitchell Cancer Research Laboratories, Discipline of Medicine, The University of Adelaide, Hanson Institute, PO Box 14 Rundle Mall, Adelaide, South Australia, 5000, Australia
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160
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Dugast-Darzacq C, Grange T. MethylQuant: a real-time PCR-based method to quantify DNA methylation at single specific cytosines. Methods Mol Biol 2009; 507:281-303. [PMID: 18987822 DOI: 10.1007/978-1-59745-522-0_21] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
MethylQuant is a cost-effective and relatively simple technique which enables quantitative analysis of the methylation status of a single cytosine at specific positions in DNA that can be assimilated to the quantitative detection of a single nucleotide polymorphism (SNP). After bisulfite conversion of DNA and PCR amplification of the region of interest, the methylation status is quantified by methylation-specific real-time PCR with one of the primers harboring the methylation status-specific nucleotide at the most 3' end. In parallel, the amount of amplifiable DNA is quantified by a methylation-independent real-time PCR. In this protocol, we describe in detail the different stages of the MethylQuant procedure and discuss the parameters of DNA bisulfite conversion and quantitative PCR analysis with SYBR green that are crucial to achieve an accurate quantification of the methylation status of a particular cytosine. The practical aspects of DNA bisulfite conversion, primer design, and quantitative PCR analysis, discussed hereafter, should be of general interest even outside the context of the MethylQuant technique.
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161
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Rigourd V, Chauvet C, Chelbi ST, Rebourcet R, Mondon F, Letourneur F, Mignot TM, Barbaux S, Vaiman D. STOX1 overexpression in choriocarcinoma cells mimics transcriptional alterations observed in preeclamptic placentas. PLoS One 2008; 3:e3905. [PMID: 19079545 PMCID: PMC2592700 DOI: 10.1371/journal.pone.0003905] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 11/15/2008] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Mutations in STOX1 were proposed to be causal for predisposing to preeclampsia, a hypertensive disorder originating from placental defects, affecting up to 10% of human pregnancies. However, after the first study published in 2005 three other groups have dismissed the polymorphism described in the first paper as a causal mutation. METHODOLOGY AND PRINCIPAL FINDINGS In the present study, we have produced a choriocarcinoma cell line overexpressing STOX1. This overexpression results in transcriptional modification of 12.5% of the genes, some of them being direct targets as shown by chromatin immunoprecipitation. STOX1 overexpression correlates strongly and specifically with transcriptomic alterations in preeclamptic placentas (r = 0.30, p = 9.10(-7)). Numerous known key modulators of preeclampsia (such as Endoglin, Syncytin, human chorionic gonadotrophin -hCG-, and Glial Cell Missing Homolog -GCM1-) were modified in these transformed choriocarcinoma cells. CONCLUSIONS Our results contribute to reconcile contradictory data concerning the involvement of STOX1 in preeclampsia. In addition, they strongly suggest that anomalies in STOX1 expression are associated with the onset of preeclampsia, thus indicating that this gene should be the target of future studies. Our cellular model could constitute an invaluable resource for studying specific aspects of this human disease.
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Affiliation(s)
- Virginie Rigourd
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Caroline Chauvet
- Inserm UMR-S747, Université Paris Descartes, Centre Universitaire des Saints Pères 45, Paris, France
| | - Sonia T. Chelbi
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Régis Rebourcet
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Françoise Mondon
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Franck Letourneur
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
- Plate-forme Génomique, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
| | - Thérèse-Marie Mignot
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Sandrine Barbaux
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
| | - Daniel Vaiman
- Equipe 21, Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France
- Inserm, U567, Paris, France
- * E-mail:
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162
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Active DNA demethylation and DNA repair. Differentiation 2008; 77:1-11. [PMID: 19281759 DOI: 10.1016/j.diff.2008.09.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 06/19/2008] [Accepted: 07/07/2008] [Indexed: 12/17/2022]
Abstract
DNA methylation on cytosine is an epigenetic modification and is essential for gene regulation and genome stability in vertebrates. Traditionally DNA methylation was considered as the most stable of all heritable epigenetic marks. However, it has become clear that DNA methylation is reversible by enzymatic "active" DNA demethylation, with examples in plant cells, animal development and immune cells. It emerges that "pruning" of methylated cytosines by active DNA demethylation is an important determinant for the DNA methylation signature of a cell. Work in plants and animals shows that demethylation occurs by base excision and nucleotide excision repair. Far from merely protecting genomic integrity from environmental insult, DNA repair is therefore at the heart of an epigenetic activation process.
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163
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DeRuiter MC, Alkemade FE, Gittenberger-de Groot AC, Poelmann RE, Havekes LM, van Dijk KW. Maternal transmission of risk for atherosclerosis. Curr Opin Lipidol 2008; 19:333-7. [PMID: 18607178 DOI: 10.1097/mol.0b013e328304b670] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW In the last 20 years, an increasing amount of epidemiological and pathological evidence has become available illustrating the relationship between an adverse in-utero environment and increased risk of vascular disease in the offspring. It is now generally accepted that epigenetic phenomena, such as either DNA methylation or chromatin modifications or both mediate the long-term memory and thus developmental programming of cells and tissues. RECENT FINDINGS In utero, the placenta and fetus are exposed to the metabolic, antioxidant and pro-inflammatory and anti-inflammatory signals from the mother and will likely respond specifically. In the fetus, these responses may lead to permanent changes either in DNA methylation or chromatin modification or both and these changes may lead to increased atherosclerosis susceptibility in adulthood. However, the molecular mechanisms responsible for the translation of an adverse maternal environment into permanent epigenetic changes are poorly understood. SUMMARY In this review, we briefly summarize the possible signals crossing the placental barrier and discuss the molecular mechanisms of epigenetic programming in the developing fetus leading to increased athero-susceptibility of the vessel wall.
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Affiliation(s)
- Marco C DeRuiter
- Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands.
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164
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Gatford KL, Owens JA, Li S, Moss TJM, Newnham JP, Challis JRG, Sloboda DM. Repeated betamethasone treatment of pregnant sheep programs persistent reductions in circulating IGF-I and IGF-binding proteins in progeny. Am J Physiol Endocrinol Metab 2008; 295:E170-8. [PMID: 18492775 PMCID: PMC2493590 DOI: 10.1152/ajpendo.00047.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure to synthetic glucocorticoids in utero markedly improves survival after preterm birth, but repeated exposures impair fetal and postnatal growth and are associated with evidence of insulin resistance in later life. The insulin-like growth factor (IGF) axis is an important regulator of growth and metabolism before and after birth. We have therefore investigated the effects of repeated maternal betamethasone injections on plasma IGF-I, IGF-II, and IGF-binding proteins (IGFBP) in fetal and postnatal progeny in the sheep. Pregnant sheep carrying male fetuses were injected with saline or betamethasone at 104, 111, and 118 days of gestation (dG, term approximately 150 dG). Plasma samples were collected postmortem from fetuses before (75, 84, 101 dG) or after one (109 dG), two (116 dG), or three (121-122, 132-133, 145-147 dG) doses of saline or betamethasone and from progeny at 42 and 84 days of age. Fetal weight was reduced after two or more maternal betamethasone injections, and this effect persisted to term. Repeated betamethasone exposures reduced plasma IGF-I and total IGFBP in fetuses at 133 dG and progeny at 84 days, and reduced plasma IGFBP-3 at 84 days. Fetal plasma IGF-II tended to increase transiently at 109 dG following the first betamethasone injection. Fetal, placental, and/or postnatal weights correlated positively with concomitant plasma IGF-I, IGF-II, and total IGFBP. We conclude that repeated exposure to synthetic glucocorticoids in utero programs the IGF axis before and after birth, which may contribute to the adverse effects of betamethasone exposure on growth and metabolism.
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Affiliation(s)
- Kathryn L Gatford
- Research Centre for Early Origins of Adult Disease, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, University of Adelaide SA 5005, Australia.
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165
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Novikova SI, He F, Bai J, Cutrufello NJ, Lidow MS, Undieh AS. Maternal cocaine administration in mice alters DNA methylation and gene expression in hippocampal neurons of neonatal and prepubertal offspring. PLoS One 2008; 3:e1919. [PMID: 18382688 PMCID: PMC2271055 DOI: 10.1371/journal.pone.0001919] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Accepted: 02/11/2008] [Indexed: 02/03/2023] Open
Abstract
Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8–19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression analysis, were evaluated in hippocampal pyramidal neurons excised by laser capture microdissection. Following maternal cocaine exposure, global DNA methylation was significantly decreased at P3 and increased at P30. Among the 492 CGIs whose methylation was significantly altered by cocaine at P3, 34% were hypermethylated while 66% were hypomethylated. Several of these CGIs contained promoter regions for genes implicated in crucial cellular functions. Endogenous expression of selected genes linked to the abnormally methylated CGIs was correspondingly decreased or increased by as much as 4–19-fold. By P30, some of the cocaine-associated effects at P3 endured, reversed to opposite directions, or disappeared. Further, additional sets of abnormally methylated targets emerged at P30 that were not observed at P3. Taken together, these observations indicate that maternal cocaine exposure during the second and third trimesters of gestation could produce potentially profound structural and functional modifications in the epigenomic programs of neonatal and prepubertal mice.
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Affiliation(s)
- Svetlana I. Novikova
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
| | - Fang He
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Jie Bai
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Nicholas J. Cutrufello
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Michael S. Lidow
- Laboratory of Neurogenomics and Proteomics, Department of Biomedical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Ashiwel S. Undieh
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, Philadelphia, Pennsylvania, United States of America
- * To whom correspondence should be addressed. E-mail:
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166
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Kudaka W, Oda T, Jinno Y, Yoshimi N, Aoki Y. Cellular Localization of Placenta-Specific Human Endogenous Retrovirus (HERV) Transcripts and their Possible Implication in Pregnancy-Induced Hypertension. Placenta 2008; 29:282-9. [DOI: 10.1016/j.placenta.2007.11.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 10/15/2007] [Accepted: 11/13/2007] [Indexed: 10/22/2022]
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167
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Patra SK, Patra A, Rizzi F, Ghosh TC, Bettuzzi S. Demethylation of (Cytosine-5-C-methyl) DNA and regulation of transcription in the epigenetic pathways of cancer development. Cancer Metastasis Rev 2008; 27:315-34. [DOI: 10.1007/s10555-008-9118-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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168
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Sensitive detection of mRNA decay products by use of reverse-ligation-mediated PCR (RL-PCR). Methods Enzymol 2008; 448:445-66. [PMID: 19111189 DOI: 10.1016/s0076-6879(08)02622-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ligation-mediated PCR allows the detection and mapping of cleavage products of specific nucleic acid molecules out of complex nucleic acid mixtures. It can be applied to the detection of either degradation products of exogenously added nucleases in footprinting applications or natural decay products or reaction intermediates. We have developed various ligation-mediated PCR approaches to analyze mRNAs, all relying on RNA ligation, followed by reverse-transcription and PCR amplification. We have termed these approaches reverse-ligation-mediated PCR (RL-PCR). The ligation event involves either an RNA linker added to the 5'-end of cleaved RNA or RNA circularization, allowing, respectively, the mapping and quantification of the cleavage points or the simultaneous analysis of the presence or absence of the 5'-cap structure and the length of the poly(A) tail. These methods enabled us to develop a very efficient 5'-RACE procedure to map mRNA 5'-ends, to footprint in permeabilized cells the interaction of regulatory proteins with RNA, to detect the products of cellular ribozyme action and to analyze cellular decay pathways that involve deadenylation and/or decapping. I review herein the methodologic aspects and protocols of the various RL-PCR procedures we have developed.
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169
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Abstract
Although there is evidence to link schizophrenia (SCZ) and bipolar disorder (BD) to genetic and environmental factors, specific individual or groups of genes/factors causative of the disease have been elusive to the research community. An understanding of the molecular aberrations that cause these mental illnesses requires comprehensive approaches that examine both genetic and epigenetic factors. Because of the overwhelming evidence for the role of environmental factors in the disease presentation, our initial approach involved deciphering how epigenetic changes resulting from promoter DNA methylation affect gene expression in SCZ and BD. Apparently, the central reversible but covalent epigenetic modification to DNA is derived from methylation of the cytosine residues that is potentially heritable and can affect gene expression and downstream activities. Environmental factors can influence DNA methylation patterns and hence alter gene expression. Such changes can be especially problematic in individuals with genetic susceptibilities to specific diseases. Recent reports from our laboratory provided compelling evidence that both hyper- and hypo-DNA methylation changes of the regulatory regions play critical roles in defining the altered functionality of genes in major psychiatric disorders such as SCZ and BD. In this chapter, we outline the technical details of the methods that could help to expand this line of research to assist with compiling the differential methylation-mediated epigenetic alterations that are responsible for the pathogenesis of SCZ, BD, and other mental diseases. We use the genes of the extended dopaminergic (DAergic) system such as membrane-bound catechol-O-methyltransferase (MB-COMT), monoamine oxidase A (MAOA), dopamine transporter 1 (DAT1), tyrosine hydroxylase (TH), dopamine (DA) receptors1 and 2 (DRD1/2), and related genes (e.g., reelin [RELN] and brain-derived neurotrophic factor [BDNF]) to illustrate the associations between differential promoter DNA methylations and disease phenotype. It is our hope that comprehensive analyses of the DAergic system as the prototype could provide the impetus and molecular basis to uncover early markers for diagnosis, help in the understanding of differences in disease severity in individuals with similar or identical genetic makeup, and assist with the identification of novel targets for therapeutic applications.
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Ikegaki N, Gotoh T, Kung B, Riceberg JS, Kim DY, Zhao H, Rappaport EF, Hicks SL, Seeger RC, Tang XX. De novo identification of MIZ-1 (ZBTB17) encoding a MYC-interacting zinc-finger protein as a new favorable neuroblastoma gene. Clin Cancer Res 2007; 13:6001-9. [PMID: 17947461 DOI: 10.1158/1078-0432.ccr-07-0071] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Neuroblastoma is a childhood cancer that exhibits either a favorable or an unfavorable phenotype. Favorable neuroblastoma genes (EPHB6, EFNB2, EFNB3, NTRK1, and CD44) are genes whose high-level expression predicts favorable neuroblastoma disease outcome. Accordingly, the forced expression of these genes or their reactivation by gene silencing inhibitors in unfavorable neuroblastoma cells results in suppression of tumor growth and metastases. This study was undertaken to design an experimental strategy to identify additional favorable neuroblastoma genes. EXPERIMENTAL DESIGN Favorable neuroblastoma gene candidates were first identified by gene expression profiling analysis on IMR5 neuroblastoma cells treated with inhibitors of DNA methylation and histone deacetylase against the untreated control cells. Among the candidates, we focused on MIZ-1, which encodes a MYC-interacting zinc-finger protein, because it is known to enhance the expression of growth suppressive genes, such as CDKN1A. RESULTS High-level MIZ-1 expression was associated with favorable disease outcome of neuroblastoma (P = 0.0048). Forced MIZ-1 expression suppressed in vitro growth of neuroblastoma cell lines. High MIZ-1 expression was correlated with the small-size neuroblastoma xenografts treated with gene silencing inhibitors or a glucocorticoid. In addition, forced MIZ-1 expression enhanced the expression of CD44 and EFNB2 in neuroblastoma cell lines in vitro. Furthermore, MIZ-1 expression was positively correlated with the expression of favorable neuroblastoma genes (EFNB2, EFNB3, EPHB6, and NTRK1) in the human neuroblastoma xenograft therapeutic models. CONCLUSION MIZ-1 is a new favorable neuroblastoma gene, which may directly or indirectly regulate the expression of other favorable neuroblastoma genes.
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Affiliation(s)
- Naohiko Ikegaki
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, Illinois, USA
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171
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Sánchez IE, Dellarole M, Gaston K, de Prat Gay G. Comprehensive comparison of the interaction of the E2 master regulator with its cognate target DNA sites in 73 human papillomavirus types by sequence statistics. Nucleic Acids Res 2007; 36:756-69. [PMID: 18084026 PMCID: PMC2241901 DOI: 10.1093/nar/gkm1104] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mucosal human papillomaviruses (HPVs) are etiological agents of oral, anal and genital cancer. Properties of high- and low-risk HPV types cannot be reduced to discrete molecular traits. The E2 protein regulates viral replication and transcription through a finely tuned interaction with four sites at the upstream regulatory region of the genome. A computational study of the E2–DNA interaction in all 73 types within the alpha papillomavirus genus, including all known mucosal types, indicates that E2 proteins have similar DNA discrimination properties. Differences in E2–DNA interaction among HPV types lie mostly in the target DNA sequence, as opposed to the amino acid sequence of the conserved DNA-binding alpha helix of E2. Sequence logos of natural and in vitro selected sites show an asymmetric pattern of conservation arising from indirect readout, and reveal evolutionary pressure for a putative methylation site. Based on DNA sequences only, we could predict differences in binding energies with a standard deviation of 0.64 kcal/mol. These energies cluster into six discrete affinity hierarchies and uncovered a fifth E2-binding site in the genome of six HPV types. Finally, certain distances between sites, affinity hierarchies and their eventual changes upon methylation, are statistically associated with high-risk types.
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Affiliation(s)
- Ignacio E Sánchez
- Fundación Instituto Leloir and IIBBA-Conicet, Patricias Argentinas 435 (1405), Buenos Aires, Argentina
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172
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Latham T, Gilbert N, Ramsahoye B. DNA methylation in mouse embryonic stem cells and development. Cell Tissue Res 2007; 331:31-55. [PMID: 18060563 DOI: 10.1007/s00441-007-0537-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 10/17/2007] [Indexed: 01/01/2023]
Abstract
Mammalian development is associated with considerable changes in global DNA methylation levels at times of genomic reprogramming. Normal DNA methylation is essential for development but, despite considerable advances in our understanding of the DNA methyltransferases, the reason that development fails when DNA methylation is deficient remains unclear. Furthermore, although much is known about the enzymes that cause DNA methylation, comparatively little is known about the mechanisms or significance of active demethylation in early development. In this review, we discuss the roles of the various DNA methyltransferases and their likely functions in development.
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Affiliation(s)
- Tom Latham
- Cancer Research Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
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173
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Huang WT, Yu HC, Hsu CC, Liao CF, Gong HY, Lin CJF, Wu JL, Weng CF. Steroid hormones (17β-estradiol and hydrocortisone) upregulate hepatocyte nuclear factor (HNF)-3β and insulin-like growth factors I and II expression in the gonads of tilapia (Oreochromis mossambicus) in vitro. Theriogenology 2007; 68:988-1002. [PMID: 17804049 DOI: 10.1016/j.theriogenology.2007.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 07/04/2007] [Indexed: 11/28/2022]
Abstract
Hepatocyte nuclear factors (HNF-1alpha, -1beta and -3beta) and insulin-like growth factors (IGF-I and -II), which are involved in liver-specific gene expression, metabolism, development and cell growth, have been found in the gonads of tilapia (Oreochromis mossambicus). However, the functions of these factors and how they interact within the gonads of bony fish are not understood. In the present study, we provided experimental evidence that the expression of HNF-3beta in the gonads of tilapia, but not HNF-1alpha and -1beta, was affected in vitro by 17beta-estradiol and hydrocortisone. Immunohistochemical staining confirmed that tilapia HNF-3beta was mainly found in the nuclei of hepatocytes, the follicular granulosa cells of the ovaries, and the interstitial cells of the testes of adult tilapia. Further data were gathered at various steroid concentrations (0.1, 1, 10, 100, and 1000 nM) over various culture intervals (6, 12, 18, 24, 30, and 36 h) and subjected to semi-quantitative RT-PCR analysis. The expression of downstream genes (IGF-I and -II) followed the same temporal patterns as HNF-3beta, albeit at decreased levels for 30 and 36 h culture intervals. Both hormones upregulated HNF-3beta mRNA expression at concentrations of 0.1-10 nM, and reached optimal physiological concentrations for induction of IGFs at 1-10 nM. The identity of the PCR fragments was concurrently verified by sequencing and PCR-Southern hybridization. We inferred that HNF-3beta and IGFs may play a regulatory role in tilapia gonads during oocyte maturation and spermatogenesis.
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Affiliation(s)
- Wei-Tung Huang
- Department of Molecular Biotechnology, Da-Yeh University, 515, Chang-Hua, Taiwan
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174
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Drake AJ, Tang JI, Nyirenda MJ. Mechanisms underlying the role of glucocorticoids in the early life programming of adult disease. Clin Sci (Lond) 2007; 113:219-32. [PMID: 17663659 DOI: 10.1042/cs20070107] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Compelling epidemiological evidence suggests that exposure to an adverse intrauterine environment, manifested by low-birth weight, is associated with cardiometabolic and behavioural disorders in adulthood. These observations have led to the concept of ‘fetal programming’. The molecular mechanisms that underlie this relationship remain unclear, but are being extensively investigated using a number of experimental models. One major hypothesis for early life physiological programming implicates fetal overexposure to stress (glucocorticoid) hormones. Several animal studies have shown that prenatal glucocorticoid excess, either from endogenous overproduction with maternal stress or through exogenous administration to the mother or fetus, reduces birth weight and causes lifelong hypertension, hyperglycaemia and behavioural abnormality in the offspring. Intriguingly, these effects are transmitted across generations without further exposure to glucocorticoids, which suggests an epigenetic mechanism. These animal observations could have huge implications if extrapolated to humans, where glucocorticoids have extensive therapeutic use in obstetric and neonatal practice.
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Affiliation(s)
- Amanda J Drake
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, Scotland, UK
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175
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Seckl JR, Holmes MC. Mechanisms of Disease: glucocorticoids, their placental metabolism and fetal 'programming' of adult pathophysiology. ACTA ACUST UNITED AC 2007; 3:479-88. [PMID: 17515892 DOI: 10.1038/ncpendmet0515] [Citation(s) in RCA: 494] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 12/22/2006] [Indexed: 11/09/2022]
Abstract
Epidemiological evidence suggests that an adverse prenatal environment permanently 'programs' physiology and increases the risk of cardiovascular, metabolic, neuroendocrine and psychiatric disorders in adulthood. Prenatal stress or exposure to excess glucocorticoids might provide the link between fetal maturation and adult pathophysiology. In a variety of animal models, prenatal stress, glucocorticoid exposure and inhibition (or knockout of) 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2)--the fetoplacental barrier to maternal glucocorticoids--reduce birth weight and cause increases in adult blood pressure, glucose levels, hypothalamic-pituitary-adrenal (HPA) axis activity and anxiety-related behaviors. In humans, mutations in the gene that encodes 11beta- hydroxysteroid dehydrogenase type 2 are associated with low birth weight. Babies with low birth weight have higher plasma cortisol levels throughout life, which indicates HPA-axis programming. In human pregnancy, severe maternal stress affects the offspring's HPA axis and is associated with neuropsychiatric disorders; moreover, maternal glucocorticoid therapy alters offspring brain function. The molecular mechanisms that underlie prenatal programming might reflect permanent changes in the expression of specific transcription factors, including the glucocorticoid receptor; tissue specific effects reflect modification of one or more of the multiple alternative first exons or promoters of the glucocorticoid receptor gene. Intriguingly, some of these effects seem to be inherited by subsequent generations that are unexposed to exogenous glucocorticoids at any point in their lifespan from fertilization, which implies that these epigenetic effects persist.
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Affiliation(s)
- Jonathan R Seckl
- College of Medicine and Veterinary Medicine, University of Edinburgh, UK
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176
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Pascussi JM, Robert A, Moreau A, Ramos J, Bioulac-Sage P, Navarro F, Blanc P, Assenat E, Maurel P, Vilarem MJ. Differential regulation of constitutive androstane receptor expression by hepatocyte nuclear factor4alpha isoforms. Hepatology 2007; 45:1146-53. [PMID: 17464991 DOI: 10.1002/hep.21592] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Constitutive androstane receptor (CAR; NR1I3) controls the metabolism and elimination of endogenous and exogenous toxic compounds by up-regulating a battery of genes. In this work, we analyzed the expression of human CAR (hCAR) in normal liver during development and in hepatocellular carcinoma (HCC) and investigated the effect of hepatocyte nuclear factor 4alpha isoforms (HNF4alpha1 and HNF4alpha7) on the hCAR gene promoter. By performing functional analysis of hCAR 5'-deletions including mutants, chromatin immunoprecipitation in human hepatocytes, electromobility shift and cotransfection assays, we identified a functional and species-conserved HNF4alpha response element (DR1: ccAGGCCTtTGCCCTga) at nucleotide -144. Both HNF4alpha isoforms bind to this element with similar affinity. However, HNF4alpha1 strongly enhanced hCAR promoter activity whereas HNF4alpha7 was a poor activator and acted as a repressor of HNF4alpha1-mediated transactivation of the hCAR promoter. PGC1alpha stimulated both HNF4alpha1-mediated and HNF4alpha7-mediated hCAR transactivation to the same extent, whereas SRC1 exhibited a marked specificity for HNF4alpha1. Transduction of human hepatocytes by HNF4alpha7-expressing lentivirus confirmed this finding. In addition, we observed a positive correlation between CAR and HNF4alpha1 mRNA levels in human liver samples during development, and an inverse correlation between CAR and HNF4alpha7 mRNA levels in HCC. These observations suggest that HNF4alpha1 positively regulates hCAR expression in normal developing and adult livers, whereas HNF4alpha7 represses hCAR gene expression in HCC.
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177
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Abstract
It is widely accepted that an association exists between the intrauterine environment in which a fetus grows and develops and the subsequent development of type 2 diabetes. Any disturbance in maternal ability to provide nutrients and oxygen to the fetus can lead to fetal intrauterine growth restriction (IUGR). Here we will review IUGR in rodent models, in which maternal metabolism has been experimentally manipulated to investigate the molecular basis of the relationship between IUGR and development of type 2 diabetes in later life, and the identification of the molecular derangements in specific metabolically - sensitive organs/tissues.
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Affiliation(s)
- M S Martin-Gronert
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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178
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Abstract
Depending on the definitions used, up to 10% of all live-born neonates are small for gestational age (SGA). Although the vast majority of these children show catch-up growth by 2 yr of age, one in 10 does not. It is increasingly recognized that those who are born SGA are at risk of developing metabolic disease later in life. Reduced fetal growth has been shown to be associated with an increased risk of insulin resistance, obesity, cardiovascular disease, and type 2 diabetes mellitus. The majority of pathology is seen in adults who show spontaneous catch-up growth as children. There is evidence to suggest that some of the metabolic consequences of intrauterine growth retardation in children born SGA can be mitigated by ensuring early appropriate catch-up growth, while avoiding excessive weight gain. Implicitly, this argument questions current infant formula feeding practices. The risk is less clear for individuals who do not show catch-up growth and who are treated with GH for short stature. Recent data, however, suggest that long-term treatment with GH does not increase the risk of type 2 diabetes mellitus and the metabolic syndrome in young adults born SGA.
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Affiliation(s)
- Paul Saenger
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York 10467, USA.
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179
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Zhang F, Pomerantz JH, Sen G, Palermo AT, Blau HM. Active tissue-specific DNA demethylation conferred by somatic cell nuclei in stable heterokaryons. Proc Natl Acad Sci U S A 2007; 104:4395-400. [PMID: 17360535 PMCID: PMC1838613 DOI: 10.1073/pnas.0700181104] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA methylation is among the most stable epigenetic marks, ensuring tissue-specific gene expression in a heritable manner throughout development. Here we report that differentiated mesodermal somatic cells can confer tissue-specific changes in DNA methylation on epidermal progenitor cells after fusion in stable multinucleate heterokaryons. Myogenic factors alter regulatory regions of genes in keratinocyte cell nuclei, demethylating and activating a muscle-specific gene and methylating and silencing a keratinocyte-specific gene. Because these changes occur in the absence of DNA replication or cell division, they are mediated by an active mechanism. Thus, the capacity to transfer epigenetic changes to other nuclei is not limited to embryonic stem cells and oocytes but is also a property of highly specialized mammalian somatic cells. These results suggest the possibility of directing the reprogramming of readily available postnatal human progenitor cells toward specific tissue cell types.
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Affiliation(s)
- Fan Zhang
- *Baxter Laboratory in Genetic Pharmacology, Departments of Microbiology and Immunology, and
| | - Jason H. Pomerantz
- *Baxter Laboratory in Genetic Pharmacology, Departments of Microbiology and Immunology, and
- Division of Plastic and Reconstructive Surgery, Department of Surgery, University of California, San Francisco, CA 94143-0932
- To whom correspondence may be addressed. E-mail:
or
| | - George Sen
- *Baxter Laboratory in Genetic Pharmacology, Departments of Microbiology and Immunology, and
- Department of Dermatology, Stanford University School of Medicine, Stanford, CA 94305-3175; and
| | - Adam T. Palermo
- *Baxter Laboratory in Genetic Pharmacology, Departments of Microbiology and Immunology, and
| | - Helen M. Blau
- *Baxter Laboratory in Genetic Pharmacology, Departments of Microbiology and Immunology, and
- To whom correspondence may be addressed. E-mail:
or
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180
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Roach HI, Aigner T. DNA methylation in osteoarthritic chondrocytes: a new molecular target. Osteoarthritis Cartilage 2007; 15:128-37. [PMID: 16908204 DOI: 10.1016/j.joca.2006.07.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Accepted: 07/09/2006] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To review the current knowledge of the mechanism of DNA methylation, its association with transcriptional silencing, possible mechanisms of hyper- and hypomethylation and how epigenetic changes may relate to the pathogenesis of osteoarthritis (OA). METHODS Journal literature was searched using Pubmed. Since there are very few publications directly on epigenetic phenomena in OA, the search was extended to give an overview of epigenetic mechanisms as they relate to the molecular mechanisms of the disease. RESULTS While the epigenetics of cancer cells have been intensively investigated, little attention has so far been paid as to whether epigenetic changes contribute to the pathology of non-neoplastic diseases such as OA. This review explains the mechanisms of DNA methylation, its role in transcriptional regulation, and possible demethylation mechanisms that may be applicable to OA. Preliminary evidence suggests that changes in DNA methylation, together with cytokines, growth factors and changes in matrix composition, are likely to be important in determining the complex gene expression patterns that are observed in osteoarthritic chondrocytes. CONCLUSION Early evidence points to a role of epigenetics in the pathogenesis of OA. Since epigenetic changes, although heritable at the cellular level, are potentially reversible, epigenetics could be a new molecular target for therapeutic intervention, especially early in the disease.
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Affiliation(s)
- H I Roach
- Bone and Joint Research Group, Division of Developmental Origins of Health and Disease, University of Southampton, UK.
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181
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Mizoguchi Y, Kajiume T, Miyagawa SI, Okada S, Nishi Y, Kobayashi M. Steroid-dependent ACTH-produced thymic carcinoid: regulation of POMC gene expression by cortisol via methylation of its promoter region. HORMONE RESEARCH 2007; 67:257-62. [PMID: 17220632 DOI: 10.1159/000098548] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 11/20/2006] [Indexed: 11/19/2022]
Abstract
AIMS Metyrapone causes a decrease in the serum cortisol level without affecting ACTH production in ectopic tumors. We report a case who presented with Cushing's syndrome due to an ectopic ACTH-producing thymic carcinoid. In the present case, it was demonstrated that metyrapone administration resulted in a significant decrease in the plasma ACTH and serum cortisol levels. We hypothesized that the steroid hormone may promote proopiomelanocortin (POMC) gene expression in the carcinoid cells. METHODS An 11-year-old boy presented with Cushing's syndrome. Prior to the detection of a thymic tumor, metyrapone was administered to ameliorate the symptoms of Cushing's syndrome. Interestingly, plasma ACTH as well as serum cortisol levels immediately decreased after metyrapone administration. The levels of cortisol and ACTH were observed to be normal after complete surgical resection of the tumor. Biological characterization of the tumor cells was by in vitro analysis. RESULTS Thein vitro culture of the tumor cells showed an increased expression of POMC in the presence of cortisol. A CpG methylation assay showed that the demethylation of the POMC promoter was induced by a steroid hormone. CONCLUSION These findings suggest that the ectopic ACTH-producing tumor may partly be regulated by the elevated levels of cortisol.
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Affiliation(s)
- Yoko Mizoguchi
- Department of Pediatrics, Hiroshima University, Hiroshima, Japan
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182
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Glucocorticoids, developmental ‘programming’ and the risk of affective dysfunction. PROGRESS IN BRAIN RESEARCH 2007; 167:17-34. [DOI: 10.1016/s0079-6123(07)67002-2] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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183
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De Bosscher K, Vanden Berghe W, Haegeman G. Cross-talk between nuclear receptors and nuclear factor kappaB. Oncogene 2006; 25:6868-86. [PMID: 17072333 DOI: 10.1038/sj.onc.1209935] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A variety of studies have shown that some activated nuclear receptors (NRs), especially the glucorticoid receptor, the estrogen receptor and peroxisome proliferator-activated receptor, can inhibit the activity of the transcription factor nuclear factor kappaB (NF-kappaB), which plays a key role in the control of genes involved in inflammation, cell proliferation and apoptosis. This review describes the molecular mechanisms of cross-talk between NRs and NF-kappaB and the biological relevance of this cross-talk. The importance and mechanistic aspects of selective NR modulation are discussed. Also included are future research prospects, which will lead to a new era in the field of NR research with the aim of specifically inhibiting NF-kappaB-driven gene expression for anti-inflammatory, anti-tumor and immune-modulatory purposes.
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Affiliation(s)
- K De Bosscher
- Laboratory for Eukaryotic Gene Expression and Signal Transduction (LEGEST), Department of Molecular Biology, Ghent University, Gent, Belgium.
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184
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Vanden Berghe W, Ndlovu MN, Hoya-Arias R, Dijsselbloem N, Gerlo S, Haegeman G. Keeping up NF-κB appearances: Epigenetic control of immunity or inflammation-triggered epigenetics. Biochem Pharmacol 2006; 72:1114-31. [PMID: 16934762 DOI: 10.1016/j.bcp.2006.07.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 07/13/2006] [Accepted: 07/17/2006] [Indexed: 02/06/2023]
Abstract
Controlled expression of cytokine genes is an essential component of an immune response and is crucial for homeostasis. In order to generate an appropriate response to an infectious condition, the type of cytokine, as well as the cell type, dose range and the kinetics of its expression are of critical importance. The nuclear factor-kappaB (NF-kappaB) family of transcription factors has a crucial role in rapid responses to stress and pathogens (innate immunity), as well as in development and differentiation of immune cells (acquired immunity). Although quite a number of genes contain NF-kappaB-responsive elements in their regulatory regions, their expression pattern can significantly vary from both a kinetic and quantitative point of view, reflecting the impact of environmental and differentiative cues. At the transcription level, selectivity is conferred by the expression of specific NF-kappaB subunits and their respective posttranslational modifications, and by combinatorial interactions between NF-kappaB and other transcription factors and coactivators, that form specific enhanceosome complexes in association with particular promoters. These enhanceosome complexes represent another level of signaling integration, whereby the activities of multiple upstream pathways converge to impress a distinct pattern of gene expression upon the NF-kappaB-dependent transcriptional network. Today, several pieces of evidence suggest that the chromatin structure and epigenetic settings are the ultimate integration sites of both environmental and differentiative inputs, determining proper expression of each NF-kappaB-dependent gene. We will therefore discuss in this review the multilayered interplay of NF-kappaB signaling and epigenome dynamics, in achieving appropriate gene expression responses and transcriptional activity.
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Affiliation(s)
- Wim Vanden Berghe
- Laboratory for Eukaryotic Gene Expression and Signal Transduction (LEGEST), Department of Molecular Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
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185
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Chalaya TV, Akopov SB, Nikolaev LG, Sverdlov ED. Tissue specificity of methylation of cytosines in regulatory regions of four genes located in the locus FXYD5-COX7A1 of human chromosome 19: correlation with their expression level. BIOCHEMISTRY (MOSCOW) 2006; 71:294-9. [PMID: 16545066 DOI: 10.1134/s0006297906030096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this study, we compared degree of methylation of selected CpG sites in CCGG sequences located in promoter regions of four human genes with expression level of these genes in several human cell lines and tissues. These genes were subdivided into two groups according to the dependence of their expression on CpG methylation in the 5 -regions. The first group, characterized by clear correlation of methylation with the transcription level, includes housekeeping gene COX6B (the absence of methylation unambiguously correlates with expression) and urothelium-specific uroplakin gene (the methylation coincides with absence of expression). The second group includes genes that are expressed in many, but not all tissues and cells. For these genes (LEAP-1 and ATP4A), there was no correlation between methylation and expression. It is possible that methylation provides some basal level of gene repression, which is overcome by binding of tissue-specific transcription factors, whereas lack of methylation gives the opportunity for gene expression in various cells and tissues.
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Affiliation(s)
- T V Chalaya
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow
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186
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Bonifer C, Lefevre P, Tagoh H. The Regulation of Chromatin and DNA-Methylation Patterns in Blood Cell Development. Curr Top Microbiol Immunol 2006; 310:1-12. [PMID: 16909903 DOI: 10.1007/3-540-31181-5_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
All developmental processes in metazoans require the establishment of different genetic programs to generate functionally specialised cells. Differential gene expression is also the basis for the alterations in the developmental potential of differentiating cells. However, the molecular details concerning how this is achieved are still poorly understood. The haematopoietic system has for many years served as an excellent model system to studyhow developmental processes are regulated at the epigenetic level. In this article we will summarise recent results from others and from our own laboratory that have yielded profound insights into the general principles of how cell-fate decisions are regulated in the cell nucleus. We summarise (1) how the interplay of sequence-specific transcription factors and chromatin components is responsible for the cell type and cell stage-specific activation of specific genes and (2) how these findings impact on current concepts of epigenetic regulation of developmental processes.
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Affiliation(s)
- C Bonifer
- Division of Experimental Haematology, Institute for Molecular Medicine, Epidemiology and Cancer Research, University of Leeds, St James's University Hospital, UK.
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187
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Kress C, Thomassin H, Grange T. Active cytosine demethylation triggered by a nuclear receptor involves DNA strand breaks. Proc Natl Acad Sci U S A 2006; 103:11112-7. [PMID: 16840560 PMCID: PMC1544051 DOI: 10.1073/pnas.0601793103] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Indexed: 12/31/2022] Open
Abstract
Cytosine methylation at CpG dinucleotides contributes to the epigenetic maintenance of gene silencing. Dynamic reprogramming of DNA methylation patterns is believed to play a key role during development and differentiation in vertebrates. The mechanisms of DNA demethylation remain unclear and controversial. Here, we present a detailed characterization of the demethylation of an endogenous gene in cultured cells. This demethylation is triggered in a regulatory region by a transcriptional activator, the glucocorticoid receptor. We show that DNA demethylation is an active process, occurring independently of DNA replication, and in a distributive manner without concerted demethylation of cytosines on both strands. We demonstrate that the DNA backbone is cleaved 3' to the methyl cytidine during demethylation, and we suggest that a DNA repair pathway may therefore be involved in this demethylation.
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Affiliation(s)
- Clémence Kress
- Institut Jacques Monod du Centre National de la Recherche Scientifique, Universités Paris 6-7, Tour 43, 2, Place Jussieu, 75251 Paris Cedex 05, France
| | - Hélène Thomassin
- Institut Jacques Monod du Centre National de la Recherche Scientifique, Universités Paris 6-7, Tour 43, 2, Place Jussieu, 75251 Paris Cedex 05, France
| | - Thierry Grange
- Institut Jacques Monod du Centre National de la Recherche Scientifique, Universités Paris 6-7, Tour 43, 2, Place Jussieu, 75251 Paris Cedex 05, France
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188
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Vakhitova YV, Sadovnikov SV, Yamidanov RS, Seredenin SB. Cytosine demethylation in the tyrosine hydroxylase gene promoter in hypothalamus cells of rat brain under the action of 2-aminoadamantane compound Ladasten. RUSS J GENET+ 2006. [DOI: 10.1134/s1022795406070155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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189
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Sanders VM. Epigenetic regulation of Th1 and Th2 cell development. Brain Behav Immun 2006; 20:317-24. [PMID: 16226007 DOI: 10.1016/j.bbi.2005.08.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 08/23/2005] [Accepted: 08/26/2005] [Indexed: 11/18/2022] Open
Abstract
All cells of the body, regardless of the tissue type, contain the same genetic material, but express this genetic material differently. Epigenetics is one process by which differential gene expression within a cell is regulated. Epigenetic mechanisms involve postsynthetic modifications to DNA and/or DNA-associated histones that do not change the DNA sequence itself, but which remodel chromatin, are passed along at each cell division, and occur during and after early development. The CD4+ T cell best represents a cell in which epigenetic mechanisms are used to affect mature cell physiology. As a naïve CD4+ T cell develops into either a Th1 or Th2 cell that secretes predominantly IFN-gamma or IL-4, respectively, the expression of one cytokine gene and the permanent silencing of the other is orchestrated using epigenetic mechanisms. Because there appears to be an association between Th1/Th2 cell immunity, behavior, and/or disease, it is possible that an environmentally induced epigenetic change that occurs during Th1/Th2 cell development could explain how certain Th1/Th2-associated conditions develop. This article will review basic epigenetic mechanisms and what is known about how these mechanisms influence cytokine gene expression in a naïve CD4+ T cell as it develops into a Th1 or Th2 cell.
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Affiliation(s)
- Virginia M Sanders
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University Medical Center, Columbus, OH, USA.
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190
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Abstract
Epidemiological data have linked an adverse fetal environment with increased risks of cardiovascular, metabolic, neuroendocrine, and psychiatric disorders in adulthood. Prenatal stress and/or glucocorticoid excess might underlie this link. In animal models, prenatal stress, glucocorticoid exposure or inhibition/knockout of 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD-2), the feto-placental barrier to maternal glucocorticoids, reduces birth weight and causes permanent hypertension, hyperglycemia, increased hypothalamic-pituitary-adrenal (HPA) axis activity and behavior resembling of anxiety. In humans, 11 beta-HSD-2 gene mutations cause low birth weight and placental 11 beta-HSD-2 activity correlates directly with birth weight and inversely with infant blood pressure. Low birth weight babies have higher plasma cortisol levels throughout adult life, indicating HPA programming. In human pregnancy, severe maternal stress affects the offspring HPA axis and associates with neuropsychiatric disorders. Posttraumatic stress disorder (PTSD) appears to be a variable in the effects. Intriguingly, some of these effects appear to be 'inherited' into a further generation, itself unexposed to exogenous glucocorticoids at any point in the lifespan from fertilization, implying epigenetic marks persist into subsequent generation(s). Overall, the data suggest that prenatal exposure to excess glucocorticoids programs peripheral and CNS functions in adult life, predisposing to some pathologies, perhaps protecting from others, and these may be transmitted perhaps to one or two subsequent generations.
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Affiliation(s)
- Jonathan R Seckl
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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191
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Hoogenkamp M, Stallen JMP, Lamers WH, Gaemers IC. In vivo footprinting of the carbamoylphosphate synthetase I cAMP-response unit indicates important roles for FoxA and PKA in formation of the enhanceosome. Biochimie 2006; 88:1357-66. [PMID: 16824661 DOI: 10.1016/j.biochi.2006.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 06/05/2006] [Indexed: 10/24/2022]
Abstract
The expression of carbamoylphosphate synthetase-I (CPS), the first and rate-determining enzyme of the urea cycle, is regulated at the transcriptional level by glucocorticoids and glucagon, the latter acting via cyclic AMP (cAMP). The hormonal response is mediated by a distal enhancer located 6.3 kb upstream of the transcription-start site. Within this enhancer, a cAMP-response unit (CRU) is responsible for mediating cAMP-dependent transcriptional activity. The CPS CRU contains binding sites for cAMP-response element (CRE)-binding protein (CRE-BP), forkhead box A (FoxA), CCAAT/enhancer-binding protein (C/EBP), and an unidentified protein P1. To gain insight in the protein-DNA interactions that activate the CPS CRU in living cells, we have employed in vivo footprinting assays. Comparison of the fibroblast cell line Rat-1 and the hepatoma cell lines FTO-2B and WT-8 showed that FoxA binds the CPS CRU constitutively in CPS-expressing cells only. Comparison of FTO-2B and WT-8 hepatoma cells, which only differ in cAMP responsiveness, demonstrated that the binding of the other transcription factors is dependent on cAMP-dependent protein kinase (PKA) activity. Finally, we observed a footprint between the CRE and the P1-binding site in the in vivo footprint assay that was not detectable by in vitro footprint assays, implying a major change in CRU-associated chromatin conformation upon CRU activation. These findings indicate that activation of the CRU is initiated in a tissue-specific manner by the binding of FoxA. When cellular cAMP and glucocorticoid levels increase, CRE-BP becomes activated, allowing the binding of the remaining transcription factors and the transactivation of the CPS promoter.
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Affiliation(s)
- M Hoogenkamp
- AMC Liver Centre, Academic Medical Centre, University of Amsterdam, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
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192
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Stover PJ, Garza C. Nutrition and developmental biology--implications for public health. Nutr Rev 2006; 64:S60-71; discussion S72-91. [PMID: 16770956 DOI: 10.1111/j.1753-4887.2006.tb00248.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Recent advances in understanding genome-nutrient and nutrient-network interactions, and the modifying effects of genetic variation on their function, have strengthened interests in acute and long-lasting diet/ nutrition influences on health. Relationships between early and mid-gestational and perinatal conditions (including those related to maternal nutrition) and outcomes, and later-onset chronic diseases have received particular attention. Controlled animal experiments support views that responses with long-lasting effects to nutritional milieus are enabled by epigenetic and other metabolic adjustments during critical windows. Thus, underlying mechanisms are beginning to be understood. For example, chromatin remodeling during development can alter gene expression levels, fix or determine future set points critical to intra- and inter-organ communication networks, alter morphogenesis, initiate remodeling events, etc., all with lifelong consequences. These also may affect DNA mutation rates and thereby influence adult cancer and other risks. There is increasing evidence that nutrient-based strategies will be of value to the prevention or delay of onset of chronic diseases and that these strategies may require initiation during embryonic or fetal stages of development to achieve maximal benefit.
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Affiliation(s)
- Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA.
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193
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Fowden AL, Sibley C, Reik W, Constancia M. Imprinted genes, placental development and fetal growth. HORMONE RESEARCH 2006; 65 Suppl 3:50-8. [PMID: 16612114 DOI: 10.1159/000091506] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In mammals, imprinted genes have an important role in feto-placental development. They affect the growth, morphology and nutrient transfer capacity of the placenta and, thereby, control the nutrient supply for fetal growth. In particular, the reciprocally imprinted Igf2-H19 gene complex has a central role in these processes and matches the placental nutrient supply to the fetal nutrient demands for growth. Comparison of Igf2P0 and complete Igf2 null mice has shown that interplay between placental and fetal Igf2 regulates both placental growth and nutrient transporter abundance. In turn, epigenetic modification of imprinted genes via changes in DNA methylation may provide a mechanism linking environmental cues to placental phenotype, with consequences for development both before and after birth. Changes in expression of imprinted genes, therefore, have major implications for developmental programming and may explain the poor prognosis of the infant born small for gestational age and the wide spectrum of adult-onset diseases that originate in utero.
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Affiliation(s)
- A L Fowden
- Department of Physiology, Cambridge, UK.
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194
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Fowden AL, Giussani DA, Forhead AJ. Intrauterine programming of physiological systems: causes and consequences. Physiology (Bethesda) 2006; 21:29-37. [PMID: 16443820 DOI: 10.1152/physiol.00050.2005] [Citation(s) in RCA: 300] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The intrauterine conditions in which the mammalian fetus develops have an important role in regulating the function of its physiological systems later in life. Changes in the intrauterine availability of nutrients, oxygen, and hormones program tissue development and lead to abnormalities in adult cardiovascular and metabolic function in several species. The timing, duration, severity, and type of insult during development determines the specific physiological outcome. Intrauterine programming of physiological systems occurs at the gene, cell, tissue, organ, and system levels and causes permanent structural and functional changes, which can lead to overt disease, particularly with increasing age.
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Affiliation(s)
- Abigail L Fowden
- Department of Physiology, University of Cambridge, Cambridge, UK.
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195
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Shen HM, Nakamura A, Sugimoto J, Sakumoto N, Oda T, Jinno Y, Okazaki Y. Tissue specificity of methylation and expression of human genes coding for neuropeptides and their receptors, and of a human endogenous retrovirus K family. J Hum Genet 2006; 51:440-450. [PMID: 16544050 DOI: 10.1007/s10038-006-0382-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 01/23/2006] [Indexed: 02/03/2023]
Abstract
The purpose of the present study was to understand the tissue specificity of DNA methylation and the relationship between methylation and expression of genes with essential roles in neurodevelopment and brain function. We chose dopamine receptor genes (DRD1 and DRD2), NCAM, and COMT as examples of genes with CpG islands around the promoter region, and serotonin receptor genes (HTR2A and HTR3A), HCRT, and DRD3 as genes without CpG islands. Methylation states were investigated in fetal brain, fetal liver, placenta, and in adult peripheral leukocytes from three individuals by Southern blot and bisulfite-modified DNA sequencing. A repetitive sequence, human endogenous retrovirus (HERV)-K was also examined. All genes examined were almost completely unmethylated in brains. The genes with CpG islands were unmethylated regardless of their expression state. In contrast, genes without CpG islands showed various methylation patterns, which did not necessarily reflect the transcriptional activity of the genes. Most HERV-K loci were methylated, but some loci showed relatively low methylation in the placenta and liver. Interestingly, we found inter-individual differences in methylation levels in HTR2A and HCRT in the placenta and in some loci of HERV-K in the placenta and liver. The sample with the lowest methylation levels in the two unique genes showed higher methylation of HERV-K loci than the other samples. These results provide detailed information about the methylation states of the genes analyzed and evidence for inter-individual variations in methylation in both unique and repetitive sequences.
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Affiliation(s)
- Hong-Mei Shen
- Department of Molecular Biology, Ryukyu University School of Medicine, 207 Nishihara, Okinawa 903-0215, Japan
| | - Akifumi Nakamura
- Department of Molecular Biology, Ryukyu University School of Medicine, 207 Nishihara, Okinawa 903-0215, Japan
- Department of Neuropsychiatry, Ryukyu University School of Medicine, Okinawa, Japan
| | - Jun Sugimoto
- Department of Molecular Biology, Ryukyu University School of Medicine, 207 Nishihara, Okinawa 903-0215, Japan
| | - Noboru Sakumoto
- Department of Neuropsychiatry, Ryukyu University School of Medicine, Okinawa, Japan
| | - Takaya Oda
- Department of Molecular Biology, Ryukyu University School of Medicine, 207 Nishihara, Okinawa 903-0215, Japan
| | - Yoshihiro Jinno
- Department of Molecular Biology, Ryukyu University School of Medicine, 207 Nishihara, Okinawa 903-0215, Japan.
| | - Yuji Okazaki
- Department of Neuropsychiatry, Mie University School of Medicine, Mie, Japan
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196
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Abstract
Coordinated interactions between the embryo/fetus and its environment are critical for proper development. In addition to acting as metabolic substrates for cellular homeostasis, basic physiological factors, such as oxygen tension, have a profound influence on developmental outcomes. Since the mammalian embryo resides in a physiologically hypoxic environment during gestation, understanding its responses to oxygen deprivation on a cellular level is critical. In this review, we analyze interactions between the hypoxia-inducible factor family of transcriptional regulators and epigenetic mechanisms governing chromatin structure. The ability of hypoxia-inducible factors to interact physically with histone deacetylase (HDAC) enzymes and modulate nuclear HDAC activities places them in the pivotal position of integrating physiological and epigenetic effectors. Multiple embryonic and extra-embryonic stem cell populations in mice and humans rely on this interaction – an important determinant of stem cell fate. Dissection of the pathways involved will provide novel insights into the metabolic as well as molecular determinants of the stem cell niches that allow self-renewal of progenitors in an undifferentiated state.
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Affiliation(s)
- Kelly Okazaki
- University of California, Department of Cell and Tissue Biology, San Francisco, CA 94143, USA
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197
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Van Craenenbroeck K, De Bosscher K, Vanden Berghe W, Vanhoenacker P, Haegeman G. Role of glucocorticoids in dopamine-related neuropsychiatric disorders. Mol Cell Endocrinol 2005; 245:10-22. [PMID: 16310935 DOI: 10.1016/j.mce.2005.10.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Accepted: 10/14/2005] [Indexed: 01/12/2023]
Abstract
'Psychoneuroendocrinology' is now quickly emerging as a hot interdisciplinary research field that addresses the interplay between neuronal and endocrine signaling in psychiatric diseases. Both glucocorticoid hormones and dopamine have an important role in maintaining normal brain functions. In this review, molecular and mechanistic aspects of glucocorticoid effects on brain function and behavior will be discussed with specific reference to dopamine signaling.
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Affiliation(s)
- Kathleen Van Craenenbroeck
- Laboratory for Eukaryotic Gene Expression and Signal Transduction, LEGEST, Department of Molecular Biology, Ghent University-UGent, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
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198
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Chen ZX, Riggs AD. Maintenance and regulation of DNA methylation patterns in mammals. Biochem Cell Biol 2005; 83:438-48. [PMID: 16094447 DOI: 10.1139/o05-138] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Proper establishment and faithful maintenance of epigenetic information is crucial for the correct development of complex organisms. For mammals, it is now accepted that DNA methylation is an important mechanism for establishing stable heritable epigenetic marks. The distribution of methylation in the genome is not random, and patterns of methylated and unmethylated DNA are well regulated during normal development. The molecular mechanisms by which methylation patterns are established and maintained are complex and just beginning to be understood. In this review, we summarize recent progress in understanding the regulation of mammalian DNA methylation patterns, with an emphasis on the emerging roles of several protein and possible RNA factors. We also revisit the stochastic model of maintenance methylation and discuss its implications for epigenetic fidelity and gene regulation.
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Affiliation(s)
- Zhao-xia Chen
- Division of Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
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199
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Inayoshi Y, Kaneoka H, Machida Y, Terajima M, Dohda T, Miyake K, Iijima S. Repression of GR-Mediated Expression of the Tryptophan Oxygenase Gene by the SWI/SNF Complex during Liver Development. ACTA ACUST UNITED AC 2005; 138:457-65. [PMID: 16272140 DOI: 10.1093/jb/mvi147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The chromatin remodeling complex, SWI/SNF, is known to regulate the transcription of several genes by altering the chromatin structure in an ATP-dependent manner. SWI/SNF exclusively contains BRG1 or BRM as an ATPase subunit. In the present study, we studied the role of SWI/SNF containing BRM or BRG1 in the expression of the liver-specific tryptophan oxygenase (TO) and tyrosine aminotransferase genes. Chromatin remodeling factors significantly repressed the expression of these genes induced by glucocorticoid receptor and dexamethasone. Since the repression was not reversed by trichostatin A treatment, it seemed to be independent of the well-known histone deacetylase pathway. Knock-down of BRG1 by small interfering RNA reversed the repression in primary fetal hepatocytes. These results support a model in which SWI/SNF containing BRG1 represses late stage-specific TO gene expression at an early stage of liver development.
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Affiliation(s)
- Yujin Inayoshi
- Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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200
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Ehrlich M. The controversial denouement of vertebrate DNA methylation research. BIOCHEMISTRY (MOSCOW) 2005; 70:568-75. [PMID: 15948710 DOI: 10.1007/s10541-005-0150-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The study of the biological role of DNA methylation in vertebrates has involved considerable controversy. Research in this area has proceeded well despite the complexity of the subject and the difficulties in establishing biological roles, some of which are summarized in this review. Now there is justifiably much more interest in DNA methylation than previously, and many more laboratories are engaged in this research. The results of numerous studies indicate that some tissue-specific differences in vertebrate DNA methylation help maintain patterns of gene expression or are involved in fine-tuning or establishing expression patterns. Therefore, vertebrate DNA methylation cannot just be assigned a role in silencing transposable elements and foreign DNA sequences, as has been suggested. DNA methylation is clearly implicated in modulating X chromosome inactivation and in establishing genetic imprinting. Also, hypermethylation of CpG-rich promoters of tumor suppressor genes in cancer has a critical role in downregulating expression of these genes and thus participating in carcinogenesis. The complex nature of DNA methylation patterns extends to carcinogenesis because global DNA hypomethylation is found in the same cancers displaying hypermethylation elsewhere in the genome. A wide variety of cancers display both DNA hypomethylation and hypermethylation, and either of these types of changes can be significantly associated with tumor progression. These findings and the independence of cancer-linked DNA hypomethylation from cancer-linked hypermethylation strongly implicate DNA hypomethylation, as well as hypermethylation, in promoting carcinogenesis. Furthermore, various DNA demethylation methodologies have been shown to increase the formation of certain types of cancers in animals, and paradoxically, DNA hypermethylation can cause carcinogenesis in other model systems. Therefore, there is a need for caution in the current use of demethylating agents as anti-cancer drugs. Nonetheless, DNA demethylation therapy clearly may be very useful in cases where better alternatives do not exist.
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Affiliation(s)
- M Ehrlich
- Human Genetics Program SL31, Tulane Medical School, New Orleans, LA 70112, USA.
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