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Kumar P, Brooks HL. Sex-specific epigenetic programming in renal fibrosis and inflammation. Am J Physiol Renal Physiol 2023; 325:F578-F594. [PMID: 37560775 DOI: 10.1152/ajprenal.00091.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/18/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023] Open
Abstract
The growing prevalence of hypertension, heart disease, diabetes, and obesity along with an aging population is leading to a higher incidence of renal diseases in society. Chronic kidney disease (CKD) is characterized mainly by persistent inflammation, fibrosis, and gradual loss of renal function leading to renal failure. Sex is a known contributor to the differences in incidence and progression of CKD. Epigenetic programming is an essential regulator of renal physiology and is critically involved in the pathophysiology of renal injury and fibrosis. Epigenetic signaling integrates intrinsic and extrinsic signals onto the genome, and various environmental and hormonal stimuli, including sex hormones, which regulate gene expression and downstream cellular responses. The most extensively studied epigenetic alterations that play a critical role in renal damage include histone modifications and DNA methylation. Notably, these epigenetic alterations are reversible, making them candidates for potential therapeutic targets for the treatment of renal diseases. Here, we will summarize the current knowledge on sex differences in epigenetic modulation of renal fibrosis and inflammation and highlight some possible epigenetic therapeutic strategies for CKD treatment.
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Affiliation(s)
- Prerna Kumar
- Department of Physiology, School of Medicine, Tulane University, New Orleans, Louisiana, United States
| | - Heddwen L Brooks
- Department of Physiology, School of Medicine, Tulane University, New Orleans, Louisiana, United States
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2
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Smedlund KB, Hill JW. The role of non-neuronal cells in hypogonadotropic hypogonadism. Mol Cell Endocrinol 2020; 518:110996. [PMID: 32860862 DOI: 10.1016/j.mce.2020.110996] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/01/2020] [Accepted: 08/16/2020] [Indexed: 12/18/2022]
Abstract
The hypothalamic-pituitary-gonadal axis is controlled by gonadotropin-releasing hormone (GnRH) released by the hypothalamus. Disruption of this system leads to impaired reproductive maturation and function, a condition known as hypogonadotropic hypogonadism (HH). Most studies to date have focused on genetic causes of HH that impact neuronal development and function. However, variants may also impact the functioning of non-neuronal cells known as glia. Glial cells make up 50% of brain cells of humans, primates, and rodents. They include radial glial cells, microglia, astrocytes, tanycytes, oligodendrocytes, and oligodendrocyte precursor cells. Many of these cells influence the hypothalamic neuroendocrine system controlling fertility. Indeed, glia regulate GnRH neuronal activity and secretion, acting both at their cell bodies and their nerve endings. Recent work has also made clear that these interactions are an essential aspect of how the HPG axis integrates endocrine, metabolic, and environmental signals to control fertility. Recognition of the clinical importance of interactions between glia and the GnRH network may pave the way for the development of new treatment strategies for dysfunctions of puberty and adult fertility.
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Affiliation(s)
- Kathryn B Smedlund
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, 43614, USA; Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, 43614, USA
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, 43614, USA; Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH, 43614, USA.
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3
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Van Lieshout RJ, Savoy CD, Ferro MA, Krzeczkowski JE, Colman I. Macrosomia and psychiatric risk in adolescence. Eur Child Adolesc Psychiatry 2020; 29:1537-1545. [PMID: 31894421 DOI: 10.1007/s00787-019-01466-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 12/22/2019] [Indexed: 01/22/2023]
Abstract
The prenatal environment can exert important effects on mental health. While much research has linked low birth weight to psychopathology, the intrauterine environment associated with high birth weight (macrosomia; > 4000 g) is also sub-optimal and may increase risk. Given the increasing prevalence of macrosomic births, understanding the mental health outcomes of infants born macrosomic can help refine theories of etiology, predict disorder, and target preventive interventions. Using data from the 2014 Ontario Child Health Study (OCHS), we examined the risk for psychiatric disorders in adolescents born macrosomic. Youth (N = 2151) aged 12-17 years completed the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID). Rates of common mental disorders assessed by the MINI-KID were compared between those born at normal birth weight (NBW; 2500-4000 g, n = 1817) and adolescents born macrosomic (> 4000 g, n = 334). These associations were then adjusted for participant age, sex, socioeconomic status (SES) of the family, parental mental health, and gestational diabetes mellitus. After adjustment for covariates, adolescents born macrosomic had higher odds of conduct disorder (CD; OR = 3.19, 95% CI: 1.37-7.43), oppositional defiant disorder (ODD; OR = 1.79, 95% CI: 1.11-2.91), and ADHD (OR = 1.77, 95% CI: 1.21-2.80). Moderation analyses revealed that males born macrosomic were more likely to have psychiatric problems than their female peers. Socioeconomic disadvantage also amplified the risk posed by macrosomia for ODD, ADHD, major depressive disorder, and generalized anxiety disorder. In this study, macrosomia was associated with an increased risk of clinically significant externalizing problems in adolescence, most notably among boys and those facing socioeconomic disadvantage.
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Affiliation(s)
- Ryan J Van Lieshout
- Department of Psychiatry and Behavioural Neurosciences, St. Joseph's Healthcare Hamilton, McMaster University, West 5th Campus, 100 West 5th Street, Hamilton, ON, L8N 3K7, Canada.
| | - Calan D Savoy
- Department of Psychiatry and Behavioural Neurosciences, St. Joseph's Healthcare Hamilton, McMaster University, West 5th Campus, 100 West 5th Street, Hamilton, ON, L8N 3K7, Canada
| | - Mark A Ferro
- School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West, TJB 2311, Waterloo, ON, N2L 3G1, Canada
| | - John E Krzeczkowski
- Department of Psychiatry and Behavioural Neurosciences, St. Joseph's Healthcare Hamilton, McMaster University, West 5th Campus, 100 West 5th Street, Hamilton, ON, L8N 3K7, Canada
| | - Ian Colman
- School of Epidemiology & Public Health, University of Ottawa, 600 Peter Morand Cr, Room 308C, Ottawa, ON, K1G 5Z3, Canada
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4
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Fernández R, Ramírez K, Gómez-Gil E, Cortés-Cortés J, Mora M, Aranda G, Zayas ED, Esteva I, Almaraz MC, Guillamon A, Pásaro E. Gender-Affirming Hormone Therapy Modifies the CpG Methylation Pattern of the ESR1 Gene Promoter After Six Months of Treatment in Transmen. J Sex Med 2020; 17:1795-1806. [PMID: 32636163 DOI: 10.1016/j.jsxm.2020.05.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/25/2020] [Accepted: 05/27/2020] [Indexed: 01/15/2023]
Abstract
BACKGROUND Brain sexual differentiation is a process that results from the effects of sex steroids on the developing brain. Evidence shows that epigenetics plays a main role in the formation of enduring brain sex differences and that the estrogen receptor α (ESR1) is one of the implicated genes. AIM To analyze whether the methylation of region III (RIII) of the ESR1 promoter is involved in the biological basis of gender dysphoria. METHODS We carried out a prospective study of the CpG methylation profile of RIII (-1,188 to -790 bp) of the ESR1 promoter using bisulfite genomic sequencing in a cisgender population (10 men and 10 women) and in a transgender population (10 trans men and 10 trans women), before and after 6 months of gender-affirming hormone treatment. Cisgender and transgender populations were matched by geographical origin, age, and sex. DNAs were treated with bisulfite, amplified, cloned, and sequenced. At least 10 clones per individual from independent polymerase chain reactions were sequenced. The analysis of 671 bisulfite sequences was carried out with the QUMA (QUantification tool for Methylation Analysis) program. OUTCOMES The main outcome of this study was RIII analysis using bisulfite genomic sequencing. RESULTS We found sex differences in RIII methylation profiles in cisgender and transgender populations. Cismen showed a higher methylation degree than ciswomen at CpG sites 297, 306, 509, and at the total fragment (P ≤ .003, P ≤ .026, P ≤ .001, P ≤ .006). Transmen showed a lower methylation level than trans women at sites 306, 372, and at the total fragment (P ≤ .0001, P ≤ .018, P ≤ .0107). Before the hormone treatment, transmen showed the lowest methylation level with respect to cisgender and transgender populations, whereas transwomen reached an intermediate methylation level between both the cisgender groups. After the hormone treatment, transmen showed a statistically significant methylation increase, whereas transwomen showed a non-significant methylation decrease. After the hormone treatment, the RIII methylation differences between transmen and transwomen disappeared, and both transgender groups reached an intermediate methylation level between both the cisgender groups. CLINICAL IMPLICATIONS Clinical implications in the hormonal treatment of trans people. STRENGTHS & LIMITATIONS Increasing the number of regions analyzed in the ESR1 promoter and increasing the number of tissues analyzed would provide a better understanding of the variation in the methylation pattern. CONCLUSIONS Our data showed sex differences in RIII methylation patterns in cisgender and transgender populations before the hormone treatment. Furthermore, before the hormone treatment, transwomen and transmen showed a characteristic methylation profile, different from both the cisgender groups. But the hormonal treatment modified RIII methylation in trans populations, which are now more similar to their gender. Therefore, our results suggest that the methylation of RIII could be involved in gender dysphoria. Fernández R, Ramírez K, Gómez-Gil E, et al. Gender-Affirming Hormone Therapy Modifies the CpG Methylation Pattern of the ESR1 Gene Promoter After Six Months of Treatment in Transmen. J Sex Med 2020;17:1795-1806.
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Affiliation(s)
- Rosa Fernández
- Departamento de Psicología, Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña (UDC), Campus de Elviña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), CHUAC, SERGAS, A Coruña, Spain.
| | - Karla Ramírez
- Departamento de Psicología, Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña (UDC), Campus de Elviña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), CHUAC, SERGAS, A Coruña, Spain
| | - Esther Gómez-Gil
- Unidad de Identidad de Género, Instituto de Neurociencias, Hospital Clínic, I.D.I.B.A.P.S., Barcelona, Spain
| | - Joselyn Cortés-Cortés
- Departamento de Psicología, Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña (UDC), Campus de Elviña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), CHUAC, SERGAS, A Coruña, Spain
| | - Mireia Mora
- Departmento de Endocrinología y Nutrición, Hospital Clínic, Barcelona, Spain
| | - Gloria Aranda
- Departmento de Endocrinología y Nutrición, Hospital Clínic, Barcelona, Spain
| | - Enrique Delgado Zayas
- Departamento de Psicología, Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña (UDC), Campus de Elviña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), CHUAC, SERGAS, A Coruña, Spain
| | - Isabel Esteva
- Servicio de Endocrinología y Nutrición, Unidad de Identidad de Género del Hospital Regional Universitario de Málaga, Málaga, Spain
| | - Mari Cruz Almaraz
- Servicio de Endocrinología y Nutrición, Unidad de Identidad de Género del Hospital Regional Universitario de Málaga, Málaga, Spain
| | - Antonio Guillamon
- Departamento de Psicobiología, Universidad Nacional de Educación a Distancia, Madrid, Spain
| | - Eduardo Pásaro
- Departamento de Psicología, Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña (UDC), Campus de Elviña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), CHUAC, SERGAS, A Coruña, Spain
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5
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VanRyzin JW, Marquardt AE, McCarthy MM. Developmental origins of sex differences in the neural circuitry of play. INTERNATIONAL JOURNAL OF PLAY 2020; 9:58-75. [PMID: 33717644 PMCID: PMC7954123 DOI: 10.1080/21594937.2020.1723370] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/24/2020] [Indexed: 06/12/2023]
Abstract
Social play consists of reciprocal physical interactions between conspecifics with many features conserved across species, including the propensity for males to engage in play more frequently and with higher physical intensity. Animal models, such as the laboratory rat, reveal that the underlying neural circuitry of play is subject to sexual differentiation during a critical period early in life. In this review, we discuss the developmental processes that produce distinct neural nodes which modulate both shared and sex-specific aspects of play with a focus on the medial amygdala, lateral septum, and prefrontal cortex. While the cellular mechanisms determining sex differences in play are beginning to be uncovered, the ultimate advantages of play continue to be debated.
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Affiliation(s)
- Jonathan W. VanRyzin
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Ashley E Marquardt
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Margaret M McCarthy
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, United States
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6
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Gegenhuber B, Tollkuhn J. Signatures of sex: Sex differences in gene expression in the vertebrate brain. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2020; 9:e348. [PMID: 31106965 PMCID: PMC6864223 DOI: 10.1002/wdev.348] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/10/2019] [Accepted: 04/22/2019] [Indexed: 12/13/2022]
Abstract
Women and men differ in disease prevalence, symptoms, and progression rates for many psychiatric and neurological disorders. As more preclinical studies include both sexes in experimental design, an increasing number of sex differences in physiology and behavior have been reported. In the brain, sex-typical behaviors are thought to result from sex-specific patterns of neural activity in response to the same sensory stimulus or context. These differential firing patterns likely arise as a consequence of underlying anatomic or molecular sex differences. Accordingly, gene expression in the brains of females and males has been extensively investigated, with the goal of identifying biological pathways that specify or modulate sex differences in brain function. However, there is surprisingly little consensus on sex-biased genes across studies and only a handful of robust candidates have been pursued in the follow-up experiments. Furthermore, it is not known how or when sex-biased gene expression originates, as few studies have been performed in the developing brain. Here we integrate molecular genetic and neural circuit perspectives to provide a conceptual framework of how sex differences in gene expression can arise in the brain. We detail mechanisms of gene regulation by steroid hormones, highlight landmark studies in rodents and humans, identify emerging themes, and offer recommendations for future research. This article is categorized under: Nervous System Development > Vertebrates: General Principles Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms Gene Expression and Transcriptional Hierarchies > Sex Determination.
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Affiliation(s)
- Bruno Gegenhuber
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
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7
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Hilliard AT, Xie D, Ma Z, Snyder MP, Fernald RD. Genome-wide effects of social status on DNA methylation in the brain of a cichlid fish, Astatotilapia burtoni. BMC Genomics 2019; 20:699. [PMID: 31506062 PMCID: PMC6737626 DOI: 10.1186/s12864-019-6047-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/19/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Successful social behavior requires real-time integration of information about the environment, internal physiology, and past experience. The molecular substrates of this integration are poorly understood, but likely modulate neural plasticity and gene regulation. In the cichlid fish species Astatotilapia burtoni, male social status can shift rapidly depending on the environment, causing fast behavioral modifications and a cascade of changes in gene transcription, the brain, and the reproductive system. These changes can be permanent but are also reversible, implying the involvement of a robust but flexible mechanism that regulates plasticity based on internal and external conditions. One candidate mechanism is DNA methylation, which has been linked to social behavior in many species, including A. burtoni. But, the extent of its effects after A. burtoni social change were previously unknown. RESULTS We performed the first genome-wide search for DNA methylation patterns associated with social status in the brains of male A. burtoni, identifying hundreds of Differentially Methylated genomic Regions (DMRs) in dominant versus non-dominant fish. Most DMRs were inside genes supporting neural development, synapse function, and other processes relevant to neural plasticity, and DMRs could affect gene expression in multiple ways. DMR genes were more likely to be transcription factors, have a duplicate elsewhere in the genome, have an anti-sense lncRNA, and have more splice variants than other genes. Dozens of genes had multiple DMRs that were often seemingly positioned to regulate specific splice variants. CONCLUSIONS Our results revealed genome-wide effects of A. burtoni social status on DNA methylation in the brain and strongly suggest a role for methylation in modulating plasticity across multiple biological levels. They also suggest many novel hypotheses to address in mechanistic follow-up studies, and will be a rich resource for identifying the relationships between behavioral, neural, and transcriptional plasticity in the context of social status.
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Affiliation(s)
| | - Dan Xie
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Zhihai Ma
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Michael P. Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 USA
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8
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Gegenhuber B, Tollkuhn J. Sex Differences in the Epigenome: A Cause or Consequence of Sexual Differentiation of the Brain? Genes (Basel) 2019; 10:genes10060432. [PMID: 31181654 PMCID: PMC6627918 DOI: 10.3390/genes10060432] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 12/19/2022] Open
Abstract
Females and males display differences in neural activity patterns, behavioral responses, and incidence of psychiatric and neurological diseases. Sex differences in the brain appear throughout the animal kingdom and are largely a consequence of the physiological requirements necessary for the distinct roles of the two sexes in reproduction. As with the rest of the body, gonadal steroid hormones act to specify and regulate many of these differences. It is thought that transient hormonal signaling during brain development gives rise to persistent sex differences in gene expression via an epigenetic mechanism, leading to divergent neurodevelopmental trajectories that may underlie sex differences in disease susceptibility. However, few genes with a persistent sex difference in expression have been identified, and only a handful of studies have employed genome-wide approaches to assess sex differences in epigenomic modifications. To date, there are no confirmed examples of gene regulatory elements that direct sex differences in gene expression in the brain. Here, we review foundational studies in this field, describe transcriptional mechanisms that could act downstream of hormone receptors in the brain, and suggest future approaches for identification and validation of sex-typical gene programs. We propose that sexual differentiation of the brain involves self-perpetuating transcriptional states that canalize sex-specific development.
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Affiliation(s)
- Bruno Gegenhuber
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
| | - Jessica Tollkuhn
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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9
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McCarthy MM, Herold K, Stockman SL. Fast, furious and enduring: Sensitive versus critical periods in sexual differentiation of the brain. Physiol Behav 2018; 187:13-19. [PMID: 29101011 PMCID: PMC5844806 DOI: 10.1016/j.physbeh.2017.10.030] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/28/2017] [Accepted: 10/29/2017] [Indexed: 11/19/2022]
Abstract
Understanding critical periods in brain development and how they impact adult functioning is a primary goal of neuroscience. The sexual differentiation of the brain is a unique critical period in that it is initiated by endogenous production of a critical signaling molecule in only one sex, testosterone in fetal males. Females, by contrast, do not produce testosterone but are highly responsive to it and remain sensitive to its masculinizing effects well past the close of the critical period in males. Compared to other well characterized critical periods, such as those for the visual system or barrel cortex, the masculinization of the brain is telescoped into a few short days and initiated prenatally. The slightly longer and postnatal sensitive period in females provides a valuable tool for understanding this challenging but fundamental developmental process.
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Affiliation(s)
- Margaret M McCarthy
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore ST, Baltimore, MD 21201, United States.
| | - Kevin Herold
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore ST, Baltimore, MD 21201, United States
| | - Sara L Stockman
- Department of Pharmacology and Program in Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore ST, Baltimore, MD 21201, United States
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10
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Boschen KE, Keller SM, Roth TL, Klintsova AY. Epigenetic mechanisms in alcohol- and adversity-induced developmental origins of neurobehavioral functioning. Neurotoxicol Teratol 2018; 66:63-79. [PMID: 29305195 DOI: 10.1016/j.ntt.2017.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/11/2017] [Accepted: 12/26/2017] [Indexed: 12/13/2022]
Abstract
The long-term effects of developmental alcohol and stress exposure are well documented in both humans and non-human animal models. Damage to the brain and attendant life-long impairments in cognition and increased risk for psychiatric disorders are debilitating consequences of developmental exposure to alcohol and/or psychological stress. Here we discuss evidence for a role of epigenetic mechanisms in mediating these consequences. While we highlight some of the common ways in which stress or alcohol impact the epigenome, we point out that little is understood of the epigenome's response to experiencing both stress and alcohol exposure, though stress is a contributing factor as to why women drink during pregnancy. Advancing our understanding of this relationship is of critical concern not just for the health and well-being of individuals directly exposed to these teratogens, but for generations to come.
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Affiliation(s)
- K E Boschen
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, NC 27599, United States
| | - S M Keller
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - T L Roth
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States.
| | - A Y Klintsova
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States.
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11
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Ratnu VS, Emami MR, Bredy TW. Genetic and epigenetic factors underlying sex differences in the regulation of gene expression in the brain. J Neurosci Res 2017; 95:301-310. [PMID: 27870402 DOI: 10.1002/jnr.23886] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/13/2016] [Accepted: 07/25/2016] [Indexed: 12/14/2022]
Abstract
There are inherent biological differences between males and females that contribute to sex differences in brain function and to many sex-specific illnesses and disorders. Traditionally, it has been thought that such differences are due largely to hormonal regulation; however, there are also genetic and epigenetic effects caused by the inheritance and unequal dosage of genes located on the X and Y chromosomes. Here we discuss the evidence in favor of a genetic and epigenetic basis for sexually dimorphic behavior, as a consequence of underlying differences in the regulation of genes that drive brain function. A better understanding of sex-specific molecular processes in the brain will provide further insight for the development of novel therapeutic approaches for the treatment of neuropsychiatric disorders characterized by sex differences. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Vikram S Ratnu
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Michael R Emami
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Timothy W Bredy
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.,Department of Neurobiology and Behavior, University of California, Irvine, California
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12
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Regitz-Zagrosek V, Kararigas G. Mechanistic Pathways of Sex Differences in Cardiovascular Disease. Physiol Rev 2017; 97:1-37. [PMID: 27807199 DOI: 10.1152/physrev.00021.2015] [Citation(s) in RCA: 417] [Impact Index Per Article: 59.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Major differences between men and women exist in epidemiology, manifestation, pathophysiology, treatment, and outcome of cardiovascular diseases (CVD), such as coronary artery disease, pressure overload, hypertension, cardiomyopathy, and heart failure. Corresponding sex differences have been studied in a number of animal models, and mechanistic investigations have been undertaken to analyze the observed sex differences. We summarize the biological mechanisms of sex differences in CVD focusing on three main areas, i.e., genetic mechanisms, epigenetic mechanisms, as well as sex hormones and their receptors. We discuss relevant subtypes of sex hormone receptors, as well as genomic and nongenomic, activational and organizational effects of sex hormones. We describe the interaction of sex hormones with intracellular signaling relevant for cardiovascular cells and the cardiovascular system. Sex, sex hormones, and their receptors may affect a number of cellular processes by their synergistic action on multiple targets. We discuss in detail sex differences in organelle function and in biological processes. We conclude that there is a need for a more detailed understanding of sex differences and their underlying mechanisms, which holds the potential to design new drugs that target sex-specific cardiovascular mechanisms and affect phenotypes. The comparison of both sexes may lead to the identification of protective or maladaptive mechanisms in one sex that could serve as a novel therapeutic target in one sex or in both.
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Affiliation(s)
- Vera Regitz-Zagrosek
- Institute of Gender in Medicine & Center for Cardiovascular Research, Charite University Hospital, and DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Georgios Kararigas
- Institute of Gender in Medicine & Center for Cardiovascular Research, Charite University Hospital, and DZHK (German Centre for Cardiovascular Research), Berlin, Germany
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13
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Kigar SL, Chang L, Hayne MR, Karls NT, Auger AP. Sex differences in Gadd45b expression and methylation in the developing rodent amygdala. Brain Res 2016; 1642:461-466. [PMID: 27086974 PMCID: PMC6701186 DOI: 10.1016/j.brainres.2016.04.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/12/2016] [Accepted: 04/14/2016] [Indexed: 01/25/2023]
Abstract
Precise spatiotemporal epigenetic regulation of the genome facilitates species-typical development; sexual differentiation of the brain by gonadal hormones and sex chromosomes causes extensive epigenetic reprogramming of many cells in the body, including the brain, and may indirectly predispose males and females to different psychiatric conditions. We and others have demonstrated sex differences in DNA methylation, as well as in the enzymes that form, or 'write', this epigenetic modification. However, while a growing body of evidence suggests that DNA methylation undergoes rapid turnover and is dynamically regulated in vivo, to our knowledge no studies have been done investigating whether sex differences exist in the epigenetic 'erasers' during postnatal development. Here we report sex differences in the expression of growth arrest and DNA damage inducible factor β (Gadd45b), but not family members α (a) or γ (g), in the neonatal and juvenile rodent amygdala.
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Affiliation(s)
- Stacey L Kigar
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States.
| | - Liza Chang
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States.
| | - Margaret R Hayne
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States
| | - Nicolette T Karls
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States
| | - Anthony P Auger
- Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States; Neuroscience Training Program, University of Wisconsin-Madison, 1202 W Johnson St., Madison, WI 53706, United States.
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14
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Keller SM, Roth TL. Environmental influences on the female epigenome and behavior. ENVIRONMENTAL EPIGENETICS 2016; 2:dvw007. [PMID: 27746953 PMCID: PMC5065103 DOI: 10.1093/eep/dvw007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
Environmental factors have long-lasting effects on brain development and behavior. One way experiences are propagated is via epigenetic modifications to the genome. Environmentally-driven epigenetic modifications show incredible brain region- and sex-specificity, and many brain regions affected are ones involved in maternal behavior. In rodent models, females are typically the primary caregiver and thus, any environmental factors that modulate the epigenotype of the mother could have consequences for her current and future offspring. Here we review evidence of the susceptibility of the female epigenome to environmental factors, with a focus on brain regions involved in maternal behavior. Accordingly, implications for interventions that target the mother's epigenome and parenting behavior are discussed.
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Affiliation(s)
- Samantha M. Keller
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, USA
| | - Tania L. Roth
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, USA
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15
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McCarthy MM, Nugent BM. At the frontier of epigenetics of brain sex differences. Front Behav Neurosci 2015; 9:221. [PMID: 26347630 PMCID: PMC4543874 DOI: 10.3389/fnbeh.2015.00221] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 08/07/2015] [Indexed: 11/28/2022] Open
Abstract
The notion that epigenetics may play an important role in the establishment and maintenance of sex differences in the brain has garnered great enthusiasm but the reality in terms of actual advances has been slow. Two general approaches include the comparison of a particular epigenetic mark in males vs. females and the inhibition of key epigenetic enzymes or co-factors to determine if this eliminates a particular sex difference in brain or behavior. The majority of emphasis has been on candidate genes such as steroid receptors. Only recently have more generalized survey type approaches been achieved and these promise to open new vistas and accelerate discovery of important roles for DNA methylation, histone modification, genomic imprinting and microRNAs (miRs). Technical challenges abound and, while not unique to this field, will require novel thinking and new approaches by behavioral neuroendocrinologists.
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Affiliation(s)
- Margaret M McCarthy
- Department of Pharmacology, University of Maryland School of Medicine Baltimore, MD, USA
| | - Bridget M Nugent
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania Philadelphia, PA, USA
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16
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Shen EY, Ahern TH, Cheung I, Straubhaar J, Dincer A, Houston I, de Vries GJ, Akbarian S, Forger NG. Epigenetics and sex differences in the brain: A genome-wide comparison of histone-3 lysine-4 trimethylation (H3K4me3) in male and female mice. Exp Neurol 2014; 268:21-9. [PMID: 25131640 DOI: 10.1016/j.expneurol.2014.08.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 07/30/2014] [Accepted: 08/05/2014] [Indexed: 12/11/2022]
Abstract
Many neurological and psychiatric disorders exhibit gender disparities, and sex differences in the brain likely explain some of these effects. Recent work in rodents points to a role for epigenetics in the development or maintenance of neural sex differences, although genome-wide studies have so far been lacking. Here we review the existing literature on epigenetics and brain sexual differentiation and present preliminary analyses on the genome-wide distribution of histone-3 lysine-4 trimethylation in a sexually dimorphic brain region in male and female mice. H3K4me3 is a histone mark primarily organized as 'peaks' surrounding the transcription start site of active genes. We microdissected the bed nucleus of the stria terminalis and preoptic area (BNST/POA) in adult male and female mice and used ChIP-Seq to compare the distribution of H3K4me3 throughout the genome. We found 248 genes and loci with a significant sex difference in H3K4me3. Of these, the majority (71%) had larger H3K4me3 peaks in females. Comparisons with existing databases indicate that genes and loci with increased H3K4me3 in females are associated with synaptic function and with expression atlases from related brain areas. Based on RT-PCR, only a minority of genes with a sex difference in H3K4me3 has detectable sex differences in expression at baseline conditions. Together with previous findings, our data suggest that there may be sex biases in the use of epigenetic marks. Such biases could underlie sex differences in vulnerabilities to drugs or diseases that disrupt specific epigenetic processes.
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Affiliation(s)
- Erica Y Shen
- Department of Psychiatry, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Todd H Ahern
- Center for Behavioral Neuroscience, Department of Psychology, Quinnipiac University, Hamden, CT 06518, USA
| | - Iris Cheung
- Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Juerg Straubhaar
- Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Aslihan Dincer
- Department of Psychiatry, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomics Science, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Isaac Houston
- Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Geert J de Vries
- Neuroscience Institute, Georgia State University, Atlanta, GA 30302, USA
| | - Schahram Akbarian
- Department of Psychiatry, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nancy G Forger
- Neuroscience Institute, Georgia State University, Atlanta, GA 30302, USA.
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17
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Uddin M, Sipahi L, Li J, Koenen KC. Sex differences in DNA methylation may contribute to risk of PTSD and depression: a review of existing evidence. Depress Anxiety 2013; 30:1151-60. [PMID: 23959810 PMCID: PMC4530966 DOI: 10.1002/da.22167] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 06/07/2013] [Accepted: 07/13/2013] [Indexed: 01/11/2023] Open
Abstract
There are well-established sex differences in the prevalence of certain mental disorders. Work in animal models has provided us with an emerging understanding of the role that epigenetic factors play in establishing sex differences in the brain during development. Similarly, work in animal models, and a more limited but growing literature based on human studies, has demonstrated that DNA methylation (DNAm) changes occur in response to environmental stress, with some of these occurring in a sex-specific manner. In this review, we explore whether DNAm plays a role in contributing to the observed sex differences in prevalence of mental disorders in which stress contributes significantly to their etiologies, specifically posttraumatic stress disorder (PTSD) and depression. We propose that investigating sex differences in DNAm among genes known to influence brain development may help to shed light on the sexually dimorphic risk for, or resilience to, developing PTSD and depression.
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Affiliation(s)
- Monica Uddin
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI
| | - Levent Sipahi
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI
| | - Jia Li
- Department of Public Health Sciences, Henry Ford Hospital, Detroit, MI
| | - Karestan C. Koenen
- Department of Epidemiology, Mailman School of Public Health, Columbia University
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18
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Kigar SL, Auger AP. Epigenetic mechanisms may underlie the aetiology of sex differences in mental health risk and resilience. J Neuroendocrinol 2013; 25:1141-50. [PMID: 23841484 PMCID: PMC4428578 DOI: 10.1111/jne.12074] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 06/26/2013] [Accepted: 07/07/2013] [Indexed: 01/16/2023]
Abstract
In this review, we propose that experiential and hormonal influences on biological sex during development may produce differences in the epigenome, and that these differences play an important role in gating risk or resilience to a number of neurological and psychiatric disorders. One intriguing hypothesis is that the framework belying sex differences in the brain creates differences in methylation and demethylation patterns, and these in turn confer risk and resilience to mental health disorders. Here, we discuss these concepts with regard to social behaviour in rodent models and briefly discuss their possible relevance to human disease.
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Affiliation(s)
- S L Kigar
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI, USA
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19
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McCarthy MM, Nugent BM. Epigenetic contributions to hormonally-mediated sexual differentiation of the brain. J Neuroendocrinol 2013; 25:1133-40. [PMID: 23919286 PMCID: PMC5330673 DOI: 10.1111/jne.12072] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/18/2013] [Accepted: 06/29/2013] [Indexed: 12/28/2022]
Abstract
It has been long established that hormones exert enduring influences on the developing brain that direct the reproductive response in adulthood, although the cellular mechanisms by which organisational effects are maintained have not been determined satisfactorily. Recent interest in epigenetic modifications to the nervous system has highlighted the potential for hormone-induced changes to the genome that could endure for the lifespan but not be transmitted to the next generation. Preliminary evidence suggests that this is indeed possible because sex differences in the histone code and in the methylation of CpGs in the promoters of specific genes have been identified and, at times, functionally correlated with behaviour. The present review provides an overview of epigenetic processes and discusses the current state-of-the-art, and also identifies future directions.
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Affiliation(s)
- M M McCarthy
- Department of Pharmacology, School of Medicine, University of Maryland, Baltimore, MD, USA
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20
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Wilson ME. Stroke: understanding the differences between males and females. Pflugers Arch 2013; 465:595-600. [PMID: 23503729 DOI: 10.1007/s00424-013-1260-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/01/2013] [Accepted: 03/01/2013] [Indexed: 01/09/2023]
Abstract
Stroke is a significant cause of death and long-term disability in the USA. The incidence, mortality, and outcomes of stroke are significantly different between men and women. As with many diseases that affect men and women differently, an understanding on the reasons underlying those differences is critical to effective diagnosis and treatment. This review will examine the sex differences in stroke in both humans and animal models of stroke and review what is known about potential mechanisms underlying these differences. It is clear that there is a complex interaction between hormonal, genetic, and unknown factors at play in generating the sex differences in stroke.
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Affiliation(s)
- Melinda E Wilson
- Department of Physiology, University of Kentucky, MS508 800 Rose St., Lexington, KY 40536, USA.
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21
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Lenz KM, Nugent BM, McCarthy MM. Sexual differentiation of the rodent brain: dogma and beyond. Front Neurosci 2012; 6:26. [PMID: 22363256 PMCID: PMC3282918 DOI: 10.3389/fnins.2012.00026] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 02/04/2012] [Indexed: 11/20/2022] Open
Abstract
Steroid hormones of gonadal origin act on the neonatal brain to produce sex differences that underlie adult reproductive physiology and behavior. Neuronal sex differences occur on a variety of levels, including differences in regional volume and/or cell number, morphology, physiology, molecular signaling, and gene expression. In the rodent, many of these sex differences are determined by steroid hormones, particularly estradiol, and are established by diverse downstream effects. One brain region that is potently organized by estradiol is the preoptic area (POA), a region critically involved in many behaviors that show sex differences, including copulatory and maternal behaviors. This review focuses on the POA as a case study exemplifying the depth and breadth of our knowledge as well as the gaps in understanding the mechanisms through which gonadal hormones produce lasting neural and behavioral sex differences. In the POA, multiple cell types, including neurons, astrocytes, and microglia are masculinized by estradiol. Multiple downstream molecular mediators are involved, including prostaglandins, various glutamate receptors, protein kinase A, and several immune signaling molecules. Moreover, emerging evidence indicates epigenetic mechanisms maintain sex differences in the POA that are organized perinatally and thereby produce permanent behavioral changes. We also review emerging strategies to better elucidate the mechanisms through which genetics and epigenetics contribute to brain and behavioral sex differences.
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Affiliation(s)
- Kathryn M Lenz
- Program in Neuroscience and Department of Physiology, University of Maryland School of Medicine Baltimore, MD, USA
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22
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Szatmari P, Liu XQ, Goldberg J, Zwaigenbaum L, Paterson AD, Woodbury-Smith M, Georgiades S, Duku E, Thompson A. Sex differences in repetitive stereotyped behaviors in autism: implications for genetic liability. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:5-12. [PMID: 22095612 DOI: 10.1002/ajmg.b.31238] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 08/18/2011] [Indexed: 11/09/2022]
Abstract
The implications of the well known sex differences in the prevalence of autism spectrum disorder (ASD) are not well understood. The aim of this paper was to investigate whether these differences might be associated with differences in genetic liability. Individuals with ASD (970 families, 2,028 individuals) were recruited as part of the Autism Genome Project (AGP). The families were differentiated into families containing a female (either female-female or male-female) and those with only males. If the sex with the lower prevalence is associated with a greater genetic liability necessary to cross sex-specific thresholds, the males from female containing families should be more severely affected than males from male only families. Affected subjects from the different types of families with ASD were sampled and compared on the social reciprocity and repetitive behavior scores from the Autism Diagnostic Interview-Revised (ADI-R). In general, females had lower repetitive behavior scores than males. More importantly, males from female containing families had higher repetitive behavior scores than males from male-male families. No such differences were apparent on the social reciprocity scores. These results support the hypothesis of a multiple threshold model of genetic liability of ASD with females having a higher liability for affectation status, at least on the repetitive behavior dimension of the disorder. These data also support the dissociation of the different phenotypic dimensions of ASD in terms of its genetic architecture. The implications of these results for linkage and association studies are discussed.
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Affiliation(s)
- Peter Szatmari
- Offord Centre for Child Studies, Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
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23
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Champagne FA. Interplay between social experiences and the genome: epigenetic consequences for behavior. ADVANCES IN GENETICS 2012; 77:33-57. [PMID: 22902125 DOI: 10.1016/b978-0-12-387687-4.00002-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Social experiences can have a persistent effect on biological processes leading to phenotypic diversity. Variation in gene regulation has emerged as a mechanism through which the interplay between DNA and environments leads to the biological encoding of these experiences. Epigenetic modifications-molecular pathways through which transcription is altered without altering the underlying DNA sequence-play a critical role in the normal process of development and are being increasingly explored as a mechanism linking environmental experiences to long-term biobehavioral outcomes. In this review, evidence implicating epigenetic factors, such as DNA methylation and histone modifications, in the link between social experiences occurring during the postnatal period and in adulthood and altered neuroendocrine and behavioral outcomes will be highlighted. In addition, the role of epigenetic mechanisms in shaping variation in social behavior and the implications of epigenetics for our understanding of the transmission of traits across generations will be discussed.
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24
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Edelmann MN, Auger AP. Epigenetic impact of simulated maternal grooming on estrogen receptor alpha within the developing amygdala. Brain Behav Immun 2011; 25:1299-304. [PMID: 21352906 PMCID: PMC3399737 DOI: 10.1016/j.bbi.2011.02.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 01/06/2023] Open
Abstract
Variations in maternal care alter the developmental programming of some genes by creating lasting differences in DNA methylation patterns, such as the estrogen receptor alpha (ERα) promoter region. Interestingly, mother rats preferentially lick and groom their male offspring more than females; therefore, we questioned whether the somatosensory stimuli associated with maternal grooming influences potential sex differences in DNA methylation patterns within the developing amygdala, an area important for socioemotional processing. We report a sex difference in the DNA methylation pattern of specific CpG sites of the ERα promoter region within the developing amygdala. Specifically, males have higher levels of ERα promoter methylation contrasted to females. Increasing the levels of maternal stimuli in females masculinized ERα promoter methylation patterns to male-like levels. As expected, higher levels of ERα promoter methylation were associated with lower ERα mRNA levels. These data provide further evidence that the early neonatal environment, particularly maternal care, contributes to sex differences and early programming of the neonatal brain via an epigenetic mechanism.
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Affiliation(s)
| | - Anthony P. Auger
- Corresponding author. Address: Department of Psychology, 1202 W Johnson Street, Madison, WI 53706, USA. (A.P. Auger)
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25
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Stolzenberg D, Grant PA, Bekiranov S. Epigenetic methodologies for behavioral scientists. Horm Behav 2011; 59:407-16. [PMID: 20955712 PMCID: PMC3093106 DOI: 10.1016/j.yhbeh.2010.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 10/05/2010] [Accepted: 10/05/2010] [Indexed: 01/12/2023]
Abstract
Hormones are essential regulators of many behaviors. Steroids bind either to nuclear or membrane receptors while peptides primarily act via membrane receptors. After a ligand binds, the conformational change in the receptor initiates changes in cell signaling cascades (membrane receptors) or direct alternations in DNA transcription (steroid receptors). Changes in gene transcription that result are responsible for protein production and ultimately behavioral modifications. A significant part of how hormones affect DNA transcription is via epigenetic modifications of DNA and/or the chromatin in which it is entwined. These alterations lead to transcriptional changes that ultimately define the phenotype and function of a given cell. Importantly we now know that environmental stimuli influence epigenetic marks, which in the context of neuroendocrinology can lead to behavioral changes. Importantly tracking epigenetic states and profiling the epigenome within cells require the use of epigenetic methodologies and subsequent data analysis. Here we describe the techniques of particular importance in the mapping of DNA methylation, histone modifications and occupancy of chromatin bound effector proteins that regulate gene expression. For researchers wanting to move into these levels of analysis we discuss the application of modern sequencing technologies applied in assays such as chromatin immunoprecipitation and the bioinformatics analysis involved in the rich datasets generated.
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Affiliation(s)
| | | | - Stefan Bekiranov
- Corresponding author: Dr. Stefan Berkiranov, PO Box 800733, University of Virginia School of Medicine, Charlottesville VA 22908,
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26
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Epigenetic control of vasopressin expression is maintained by steroid hormones in the adult male rat brain. Proc Natl Acad Sci U S A 2011; 108:4242-7. [PMID: 21368111 DOI: 10.1073/pnas.1100314108] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Although some DNA methylation patterns are altered by steroid hormone exposure in the developing brain, less is known about how changes in steroid hormone levels influence DNA methylation patterns in the adult brain. Steroid hormones act in the adult brain to regulate gene expression. Specifically, the expression of the socially relevant peptide vasopressin (AVP) within the bed nucleus of the stria terminalis (BST) of adult brain is dependent upon testosterone exposure. Castration dramatically reduces and testosterone replacement restores AVP expression within the BST. As decreases in mRNA expression are associated with increases in DNA promoter methylation, we explored the hypothesis that AVP expression in the adult brain is maintained through sustained epigenetic modifications of the AVP gene promoter. We find that castration of adult male rats resulted in decreased AVP mRNA expression and increased methylation of specific CpG sites within the AVP promoter in the BST. Similarly, castration significantly increased estrogen receptor α (ERα) mRNA expression and decreased ERα promoter methylation within the BST. These changes were prevented by testosterone replacement. This suggests that the DNA promoter methylation status of some steroid responsive genes in the adult brain is actively maintained by the presence of circulating steroid hormones. The maintenance of methylated or demethylated states of some genes in the adult brain by the presence of steroid hormones may play a role in the homeostatic regulation of behaviorally relevant systems.
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27
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Johnson NL, Carini L, Schenk ME, Stewart M, Byrnes EM. Adolescent opiate exposure in the female rat induces subtle alterations in maternal care and transgenerational effects on play behavior. Front Psychiatry 2011; 2:29. [PMID: 21713113 PMCID: PMC3112319 DOI: 10.3389/fpsyt.2011.00029] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 05/08/2011] [Indexed: 01/25/2023] Open
Abstract
The non-medical use of prescription opiates, such as Vicodin(®) and MSContin(®), has increased dramatically over the past decade. Of particular concern is the rising popularity of these drugs in adolescent female populations. Use during this critical developmental period could have significant long-term consequences for both the female user as well as potential effects on her future offspring. To address this issue, we have begun modeling adolescent opiate exposure in female rats and have observed significant transgenerational effects despite the fact that all drugs are withdrawn several weeks prior to pregnancy. The purpose of the current set of studies was to determine whether adolescent morphine exposure modifies postpartum care. In addition, we also examined juvenile play behavior in both male and female offspring. The choice of the social play paradigm was based on previous findings demonstrating effects of both postpartum care and opioid activity on play behavior. The findings revealed subtle modifications in the maternal behavior of adolescent morphine-exposed females, primarily related to the amount of time females' spend nursing and in non-nursing contact with their young. In addition, male offspring of adolescent morphine-exposed mothers (MOR-F1) demonstrate decreased rough and tumble play behaviors, with no significant differences in general social behaviors (i.e., social grooming and social exploration). Moreover, there was a tendency toward increased rough and tumble play in MOR-F1 females, demonstrating the sex-specific nature of these effects. Given the importance of the postpartum environment on neurodevelopment, it is possible that modifications in maternal-offspring interactions, related to a history of adolescent opiate exposure, plays a role in the observed transgenerational effects. Overall, these studies indicate that the long-term consequences of adolescent opiate exposure can impact both the female and her future offspring.
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Affiliation(s)
- Nicole L Johnson
- Department of Biomedical Science, Cummings School of Veterinary Medicine, Tufts University North Grafton, MA, USA
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28
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Bordner KA, George ED, Carlyle BC, Duque A, Kitchen RR, Lam TT, Colangelo CM, Stone KL, Abbott TB, Mane SM, Nairn AC, Simen AA. Functional genomic and proteomic analysis reveals disruption of myelin-related genes and translation in a mouse model of early life neglect. Front Psychiatry 2011; 2:18. [PMID: 21629843 PMCID: PMC3098717 DOI: 10.3389/fpsyt.2011.00018] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/11/2011] [Indexed: 12/13/2022] Open
Abstract
Early life neglect is an important public health problem which can lead to lasting psychological dysfunction. Good animal models are necessary to understand the mechanisms responsible for the behavioral and anatomical pathology that results. We recently described a novel model of early life neglect, maternal separation with early weaning (MSEW), that produces behavioral changes in the mouse that persist into adulthood. To begin to understand the mechanism by which MSEW leads to these changes we applied cDNA microarray, next-generation RNA-sequencing (RNA-seq), label-free proteomics, multiple reaction monitoring (MRM) proteomics, and methylation analysis to tissue samples obtained from medial prefrontal cortex to determine the molecular changes induced by MSEW that persist into adulthood. The results show that MSEW leads to dysregulation of markers of mature oligodendrocytes and genes involved in protein translation and other categories, an apparent downward biasing of translation, and methylation changes in the promoter regions of selected dysregulated genes. These findings are likely to prove useful in understanding the mechanism by which early life neglect affects brain structure, cognition, and behavior.
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Affiliation(s)
- Kelly A Bordner
- Department of Psychiatry, Yale University School of Medicine New Haven, CT, USA
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