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Linscott ML, Chung WCJ. Epigenomic control of gonadotrophin-releasing hormone neurone development and hypogonadotrophic hypogonadism. J Neuroendocrinol 2020; 32:e12860. [PMID: 32452569 DOI: 10.1111/jne.12860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 04/24/2020] [Accepted: 05/01/2020] [Indexed: 11/30/2022]
Abstract
Mammalian reproductive success depends on gonadotrophin-releasing hormone (GnRH) neurones to stimulate gonadotrophin secretion from the anterior pituitary and activate gonadal steroidogenesis and gametogenesis. Genetic screening studies in patients diagnosed with Kallmann syndrome (KS), a congenital form of hypogonadotrophic hypogonadism (CHH), identified several causal mutations, including those in the fibroblast growth factor (FGF) system. This signalling pathway regulates neuroendocrine progenitor cell proliferation, fate specification and cell survival. Indeed, the GnRH neurone system was absent or abrogated in transgenic mice with reduced (ie, hypomorphic) Fgf8 and/or Fgf receptor (Fgfr) 1 expression, respectively. Moreover, we found that GnRH neurones were absent in the embryonic olfactory placode of Fgf8 hypomorphic mice, the putative birthplace of GnRH neurones. These observations, together with those made in human KS/CHH patients, indicate that the FGF8/FGFR1 signalling system is a requirement for the ontogenesis of the GnRH neuronal system and function. In this review, we discuss how epigenetic factors control the expression of genes such as Fgf8 that are known to be critical for GnRH neurone ontogenesis, fate specification, and the pathogenesis of KS/CHH.
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Affiliation(s)
- Megan L Linscott
- Department of Biological Sciences, Kent State University, Kent, OH, USA
- Brain Health Research Institute, Kent State University, Kent, OH, USA
| | - Wilson C J Chung
- Department of Biological Sciences, Kent State University, Kent, OH, USA
- Brain Health Research Institute, Kent State University, Kent, OH, USA
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
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Bayerl DS, Klampfl SM, Bosch OJ. More than reproduction: Central gonadotropin-releasing hormone antagonism decreases maternal aggression in lactating rats. J Neuroendocrinol 2019; 31:e12709. [PMID: 30882966 DOI: 10.1111/jne.12709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/29/2019] [Accepted: 03/13/2019] [Indexed: 12/20/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) is a major regulator and activator of the hypothalamic-pituitary-gonadal axis. Many studies have demonstrated the importance of GnRH in reproduction and sexual behaviour. However, to date, only a single study shows an involvement of GnRH in maternal behaviour where a 30% reduction of GnRH neurones abolishes a mother's motivation to retrieve pups. On this basis, we aimed to investigate the effects of acute central GnRH receptor blockade in lactating rats on maternal care under non-stress and stress conditions, maternal motivation in the pup retrieval test, maternal anxiety on the elevated plus maze, and maternal aggression in the maternal defence test. We found that acute central infusion of a GnRH antagonist ([d-Phe2,6 ,Pro3 ]-luteinising hormone-releasing hormone; 0.5 ng 5 μL-1 ) impaired a mother's attack behaviour against a female intruder rat during the maternal defence test compared to vehicle controls. However, in contrast to the previous study on reduced GnRH neurones, acute central GnRH antagonism did not affect pup retrieval, nor any other parameter of maternal behaviour or maternal anxiety. Taken together, GnRH receptor activation is mandatory for protection of the offspring. These findings shed new light on GnRH as a neuropeptide acting not exclusively on the reproductive axis but, additionally, on maternal behaviour including pup retrieval and maternal aggression.
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Affiliation(s)
- Doris S Bayerl
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Stefanie M Klampfl
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Oliver J Bosch
- Department of Behavioural and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
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Creeth HDJ, McNamara GI, Isles AR, John RM. Imprinted genes influencing the quality of maternal care. Front Neuroendocrinol 2019; 53:100732. [PMID: 30553874 DOI: 10.1016/j.yfrne.2018.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/15/2018] [Accepted: 12/12/2018] [Indexed: 12/20/2022]
Abstract
In mammals successful rearing imposes a cost on later reproductive fitness specifically on the mother creating the potential for parental conflict. Loss of function of three imprinted genes in the dam results in deficits in maternal care suggesting that, like maternal nutrients, maternal care is a resource over which the parental genomes are in conflict. The induction of maternal care is a complex, highly regulated process and it is unsurprising that many gene disruptions and environmental adversities result in maternal care deficits. However, recent compelling evidence for a more purposeful imprinting phenomenon comes from observing alterations in the mother's behaviour when expression of the imprinted genes Phlda2 and Peg3 has been manipulated solely in the offspring. This explicit demonstration that imprinted genes expressed in the offspring influence maternal behaviour lends significant weight to the hypothesis that maternal care is a resource that has been manipulated by the paternal genome.
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Affiliation(s)
- H D J Creeth
- Biomedicine Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - G I McNamara
- Biomedicine Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - A R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff CF24 4HQ, UK
| | - R M John
- Biomedicine Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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Maternal care boosted by paternal imprinting in mammals. PLoS Biol 2018; 16:e2006599. [PMID: 30063711 PMCID: PMC6067684 DOI: 10.1371/journal.pbio.2006599] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/26/2018] [Indexed: 12/16/2022] Open
Abstract
In mammals, mothers are the primary caregiver, programmed, in part, by hormones produced during pregnancy. High-quality maternal care is essential for the survival and lifelong health of offspring. We previously showed that the paternally silenced imprinted gene pleckstrin homology-like domain family A member 2 (Phlda2) functions to negatively regulate a single lineage in the mouse placenta called the spongiotrophoblast, a major source of hormones in pregnancy. Consequently, the offspring's Phlda2 gene dosage may influence the quality of care provided by the mother. Here, we show that wild-type (WT) female mice exposed to offspring with three different doses of the maternally expressed Phlda2 gene-two active alleles, one active allele (the extant state), and loss of function-show changes in the maternal hypothalamus and hippocampus during pregnancy, regions important for maternal-care behaviour. After birth, WT dams exposed in utero to offspring with the highest Phlda2 dose exhibit decreased nursing and grooming of pups and increased focus on nest building. Conversely, 'paternalised' dams, exposed to the lowest Phlda2 dose, showed increased nurturing of their pups, increased self-directed behaviour, and a decreased focus on nest building, behaviour that was robustly maintained in the absence of genetically modified pups. This work raises the intriguing possibility that imprinting of Phlda2 contributed to increased maternal care during the evolution of mammals.
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Assessing Sociability, Social Memory, and Pup Retrieval in Mice. ACTA ACUST UNITED AC 2018; 7:287-305. [DOI: 10.1002/cpmo.36] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Vargas KG, Milic J, Zaciragic A, Wen KX, Jaspers L, Nano J, Dhana K, Bramer WM, Kraja B, van Beeck E, Ikram MA, Muka T, Franco OH. The functions of estrogen receptor beta in the female brain: A systematic review. Maturitas 2016; 93:41-57. [PMID: 27338976 DOI: 10.1016/j.maturitas.2016.05.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 05/31/2016] [Indexed: 01/22/2023]
Abstract
Females have unique and additional risk factors for neurological disorders. Among classical estrogen receptors, estrogen receptor beta (ERβ) has been suggested as a therapeutic target. However, little is known about the role of ERβ in the female brain. Six electronic databases were searched for articles evaluating the role of ERβ in the female brain and the influence of age and menopause on ERβ function. After screening 3186 titles and abstracts, 49 articles were included in the review, all of which were animal studies. Of these, 19 focused on cellular signaling, 7 on neuroendocrine pathways, 8 on neurological disorders, 4 on neuroprotection and 19 on psychological and psychiatric outcomes (6 studies evaluated two or more outcomes). Our findings showed that ERβ phosphorylated and activated intracellular second messenger proteins and regulated protein expression of genes involved in neurological functions. It also promoted neurogenesis, modulated the neuroendocrine regulation of stress response, conferred neuroprotection against ischemia and inflammation, and reduced anxiety- and depression-like behaviors. Targeting ERβ may constitute a novel treatment for menopausal symptoms, including anxiety, depression, and neurological diseases. However, to establish potential therapeutic and preventive strategies targeting ERβ, future studies should be conducted in humans to further our understanding of the importance of ERβ in women's mental and cognitive health.
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Affiliation(s)
- Kris G Vargas
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Jelena Milic
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Asija Zaciragic
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Ke-Xin Wen
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Loes Jaspers
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Jana Nano
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Klodian Dhana
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Bledar Kraja
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands; Department of Biomedical Sciences, Faculty of Medicine, University of Medicine, Tirana, Albania; University Clinic of Gastrohepatology, University Hospital Center Mother Teresa, Tirana, Albania
| | - Ed van Beeck
- Department of Public Health, Erasmus University Medical Center, The Netherlands
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands; Department of Neurology, Erasmus University Medical Center, The Netherlands; Department of Radiology, Erasmus University Medical Center, The Netherlands
| | - Taulant Muka
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands.
| | - Oscar H Franco
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
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Neonatal Exposure to Sevoflurane in Mice Causes Deficits in Maternal Behavior Later in Adulthood. Anesthesiology 2014; 120:403-15. [DOI: 10.1097/aln.0000435846.28299.e7] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Background:
In animal models, exposure to general anesthetics induces widespread increases in neuronal apoptosis in the developing brain. Subsequently, abnormalities in brain functioning are found in adulthood, long after the anesthetic exposure. These abnormalities include not only reduced learning abilities but also impaired social behaviors, suggesting pervasive deficits in brain functioning. But the underlying features of these deficits are still largely unknown.
Methods:
Six-day-old C57BL/6 female mice were exposed to 3% sevoflurane for 6 h with or without hydrogen (1.3%) as part of the carrier gas mixture. At 7–9 weeks of age, they were mated with healthy males. The first day after parturition, the maternal behaviors of dams were evaluated. The survival rate of newborn pups was recorded for 6 days after birth.
Results:
Female mice that received neonatal exposure to sevoflurane could mate normally and deliver healthy pups similar to controls. But these dams often left the pups scattered in the cage and nurtured them very little, so that about half of the pups died within a couple of days. Yet, these dams did not show any deficits in olfactory or exploratory behaviors. Notably, pups born to sevoflurane-treated dams were successfully fostered when nursed by control dams. Mice coadministered of hydrogen gas with sevoflurane did not exhibit the deficits of maternal behaviors.
Conclusion:
In an animal model, sevoflurane exposure in the developing brain caused serious impairment of maternal behaviors when fostering their pups, suggesting pervasive impairment of brain functions including innate behavior essential to species survival.
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