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Machado GDB, Schnitzler AL, Fleischer AW, Beamish SB, Frick KM. G protein-coupled estrogen receptor (GPER) in the dorsal hippocampus regulates memory consolidation in gonadectomized male mice, likely via different signaling mechanisms than in female mice. Horm Behav 2024; 161:105516. [PMID: 38428223 PMCID: PMC11065565 DOI: 10.1016/j.yhbeh.2024.105516] [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: 09/15/2023] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024]
Abstract
Studies in ovariectomized (OVX) female rodents suggest that G protein-coupled estrogen receptor (GPER) is a key regulator of memory, yet little is known about its importance to memory in males or the cellular mechanisms underlying its mnemonic effects in either sex. In OVX mice, bilateral infusion of the GPER agonist G-1 into the dorsal hippocampus (DH) enhances object recognition and spatial memory consolidation in a manner dependent on rapid activation of c-Jun N-terminal kinase (JNK) signaling, cofilin phosphorylation, and actin polymerization in the DH. However, the effects of GPER on memory consolidation and DH cell signaling in males are unknown. Thus, the present study first assessed effects of DH infusion of G-1 or the GPER antagonist G-15 on object recognition and spatial memory consolidation in gonadectomized (GDX) male mice. As in OVX mice, immediate post-training bilateral DH infusion of G-1 enhanced, whereas G-15 impaired, memory consolidation in the object recognition and object placement tasks. However, G-1 did not increase levels of phosphorylated JNK (p46, p54) or cofilin in the DH 5, 15, or 30 min after infusion, nor did it affect phosphorylation of ERK (p42, p44), PI3K, or Akt. Levels of phospho-cAMP-responsive element binding protein (CREB) were elevated in the DH 30 min following G-1 infusion, indicating that GPER in males activates a yet unknown signaling mechanism that triggers CREB-mediated gene transcription. Our findings show for the first time that GPER in the DH regulates memory consolidation in males and suggests sex differences in underlying signaling mechanisms.
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Affiliation(s)
- Gustavo D B Machado
- University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI 53211, United States of America
| | - Alexis L Schnitzler
- University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI 53211, United States of America
| | - Aaron W Fleischer
- University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI 53211, United States of America
| | - Sarah B Beamish
- University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI 53211, United States of America
| | - Karyn M Frick
- University of Wisconsin-Milwaukee, Department of Psychology, Milwaukee, WI 53211, United States of America.
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2
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Weese-Myers ME, Ross AE. Subsecond Codetection of Dopamine and Estradiol at a Modified Sharkfin Waveform. Anal Chem 2024; 96:76-84. [PMID: 38103188 DOI: 10.1021/acs.analchem.3c02967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
17β-Estradiol (E2) is a ubiquitously expressed hormone that is active in a wide range of neuroprotective and regenerative roles throughout the brain. In particular, it is a well-known dopamine (DA) regulator and is responsible for modulating the expression of dopaminergic receptors and transporters. Recent studies point to E2 release occurring on a rapid time scale and having impacts on DA activity within seconds to minutes. As such, tools capable of monitoring the release of both E2 and DA in real time are essential for developing an accurate understanding of their interactive roles in neurotransmission and regulation. Currently, no analytical techniques capable of codetection of both analytes with high sensitivity, spatiotemporal resolution, extended monitoring, and minimal tissue damage exist. We describe a modified waveform using fast-scan cyclic voltammetry that is capable of low nanomolar detection of both DA and E2 on a subsecond time scale. Both analytes have limits of detection at or below 30 nM and high sensitivity: 11.31 ± 0.55 nA/μM for DA and 9.47 ± 0.36 nA/μM for E2. The waveform is validated in a tissue matrix, confirming its viability for measurement in a biologically relevant setting. This is the first method capable of codetection of fluctuations in DA and E2 with the temporal, spatial, and sensitivity requirements necessary for studying real-time neurochemical signaling.
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Affiliation(s)
- Moriah E Weese-Myers
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, Ohio 45221-0172, United States
| | - Ashley E Ross
- Department of Chemistry, University of Cincinnati, 312 College Dr. 404 Crosley Tower, Cincinnati, Ohio 45221-0172, United States
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3
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Boyd HM, Frick KM, Kwapis JL. Connecting the Dots: Potential Interactions Between Sex Hormones and the Circadian System During Memory Consolidation. J Biol Rhythms 2023; 38:537-555. [PMID: 37464775 PMCID: PMC10615791 DOI: 10.1177/07487304231184761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Both the circadian clock and sex hormone signaling can strongly influence brain function, yet little is known about how these 2 powerful modulatory systems might interact during complex neural processes like memory consolidation. Individually, the molecular components and action of each of these systems have been fairly well-characterized, but there is a fundamental lack of information about how these systems cooperate. In the circadian system, clock genes function as timekeeping molecules that convey time-of-day information on a well-stereotyped cycle that is governed by the suprachiasmatic nucleus. Keeping time is particularly important to synchronize various physiological processes across the brain and body, including those that regulate memory consolidation. Similarly, sex hormones are powerful modulators of memory, with androgens, estrogens, and progestins, all influencing memory consolidation within memory-relevant brain regions like the hippocampus. Despite clear evidence that each system can influence memory individually, exactly how the circadian and hormonal systems might interact to impact memory consolidation remains unclear. Research investigating either sex hormone action or circadian gene function within memory-relevant brain regions has unveiled several notable places in which the two systems could interact to control memory. Here, we bring attention to known interactions between the circadian clock and sex hormone signaling. We then review sex hormone-mediated control of memory consolidation, highlighting potential nodes through which the circadian system might interact during memory formation. We suggest that the bidirectional relationship between these two systems is essential for proper control of memory formation based on an animal's hormonal and circadian state.
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Affiliation(s)
- Hannah M. Boyd
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania
| | - Karyn M. Frick
- Department of Psychology, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin
| | - Janine L. Kwapis
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania
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4
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Rune GM, Joue G, Sommer T. Effects of 24-hour oral estradiol-valerate administration on hormone levels in men and pre-menopausal women. Psychoneuroendocrinology 2023; 156:106320. [PMID: 37307791 DOI: 10.1016/j.psyneuen.2023.106320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/14/2023]
Abstract
In order to translate the findings from the vast animal literature on the effect of 17β-estradiol (E2) on brain and behavior to humans, a placebo-controlled pharmacological enhancement of E2 levels for at least 24 h is necessary. However, an exogenous increase in E2 for such a prolonged period might affect the endogenous secretion of other (neuroactive) hormones. Such effects would be of relevance for the interpretation of the effects of this pharmacological regimen on cognition and its neural correlates as well as be of basic scientific interest. We therefore administered a double dose of 12 mg of estradiol-valerate (E2V) to men and of 8 mg to naturally cycling women in their low-hormone phase, and assessed the concentration of two steroids critical to hormone regulation: follicle stimulating hormone (FSH) and luteinizing hormone (LH). We also assessed any changes in concentration of the neuroactive hormones progesterone (P4), testosterone (TST), dihydrotestosterone (DHT) and immune-like growth factor 1 (IGF-1). This regimen resulted in similar E2 levels in both sexes (saliva and serum). FSH and LH levels in both sexes were down-regulated to the same degree. P4 concentration decreased in both sexes only in serum but not saliva. TST and DHT levels dropped only in men whereas sex-hormone binding globulin was not affected. Finally, the concentration of IGF-1 decreased in both sexes. Based on previous studies on the effects of these neuroactive hormones, only the degree of downregulation of TST and DHT levels in men might have an impact on brain and behavior, which should be considered when interpreting the effects of the presented E2V regimes.
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Affiliation(s)
- Gabriele M Rune
- Institute of Cell Biology and Neurobiology, Charité Anatomy, Charitéplatz 1, 10117 Berlin, Germany
| | - Gina Joue
- Institute of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20248 Hamburg, Germany
| | - Tobias Sommer
- Institute of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20248 Hamburg, Germany.
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5
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Androgens and NGF Mediate the Neurite-Outgrowth through Inactivation of RhoA. Cells 2023; 12:cells12030373. [PMID: 36766714 PMCID: PMC9913450 DOI: 10.3390/cells12030373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Steroid hormones and growth factors control neuritogenesis through their cognate receptors under physiological and pathological conditions. We have already shown that nerve growth factor and androgens induce neurite outgrowth of PC12 cells through a reciprocal crosstalk between the NGF receptor, TrkA and the androgen receptor. Here, we report that androgens or NGF induce neuritogenesis in PC12 cells through inactivation of RhoA. Ectopic expression of the dominant negative RhoA N19 promotes, indeed, the neurite-elongation of unchallenged and androgen- or NGF-challenged PC12 cells and the increase in the expression levels of βIII tubulin, a specific neuronal marker. Pharmacological inhibition of the Ser/Thr kinase ROCK, an RhoA effector, induces neuritogenesis in unchallenged PC12 cells, and potentiates the effect of androgens and NGF, confirming the role of RhoA/ROCK axis in the neuritogenesis induced by androgen and NGF, through the phosphorylation of Akt. These findings suggest that therapies based on new selective androgen receptor modulators and/or RhoA/ROCK inhibitors might exert beneficial effects in the treatment of neuro-disorders, neurological diseases and ageing-related processes.
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6
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Hernández-Vivanco A, Cano-Adamuz N, Sánchez-Aguilera A, González-Alonso A, Rodríguez-Fernández A, Azcoitia Í, de la Prida LM, Méndez P. Sex-specific regulation of inhibition and network activity by local aromatase in the mouse hippocampus. Nat Commun 2022; 13:3913. [PMID: 35798748 PMCID: PMC9262915 DOI: 10.1038/s41467-022-31635-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 06/27/2022] [Indexed: 11/15/2022] Open
Abstract
Cognitive function relies on a balanced interplay between excitatory and inhibitory neurons (INs), but the impact of estradiol on IN function is not fully understood. Here, we characterize the regulation of hippocampal INs by aromatase, the enzyme responsible for estradiol synthesis, using a combination of molecular, genetic, functional and behavioral tools. The results show that CA1 parvalbumin-expressing INs (PV-INs) contribute to brain estradiol synthesis. Brain aromatase regulates synaptic inhibition through a mechanism that involves modification of perineuronal nets enwrapping PV-INs. In the female brain, aromatase modulates PV-INs activity, the dynamics of network oscillations and hippocampal-dependent memory. Aromatase regulation of PV-INs and inhibitory synapses is determined by the gonads and independent of sex chromosomes. These results suggest PV-INs are mediators of estrogenic regulation of behaviorally-relevant activity. Using a combination of molecular, genetic, functional and behavioural tools, this study describes the impact of brain synthesized estrogen in inhibitory neuronal function, network oscillations and hippocampal dependent memory.
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Affiliation(s)
| | | | - Alberto Sánchez-Aguilera
- Instituto Cajal (CSIC), Av Dr. Arce 37, 28002, Madrid, Spain.,Department of Physiology, Faculty of Medicine, Universidad Complutense de Madrid IdISSC, Avda Complutense s/n, 28040, Madrid, Spain
| | | | | | - Íñigo Azcoitia
- Department of Cell Biology, Universidad Complutense de Madrid, C José Antonio Nováis 12, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Pablo Méndez
- Instituto Cajal (CSIC), Av Dr. Arce 37, 28002, Madrid, Spain.
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7
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Brann DW, Lu Y, Wang J, Sareddy GR, Pratap UP, Zhang Q, Tekmal RR, Vadlamudi RK. Neuron-Derived Estrogen-A Key Neuromodulator in Synaptic Function and Memory. Int J Mol Sci 2021; 22:ijms222413242. [PMID: 34948039 PMCID: PMC8706511 DOI: 10.3390/ijms222413242] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/29/2021] [Accepted: 12/04/2021] [Indexed: 01/31/2023] Open
Abstract
In addition to being a steroid hormone, 17β-estradiol (E2) is also a neurosteroid produced in neurons in various regions of the brain of many species, including humans. Neuron-derived E2 (NDE2) is synthesized from androgen precursors via the action of the biosynthetic enzyme aromatase, which is located at synapses and in presynaptic terminals in neurons in both the male and female brain. In this review, we discuss evidence supporting a key role for NDE2 as a neuromodulator that regulates synaptic plasticity and memory. Evidence supporting an important neuromodulatory role of NDE2 in the brain has come from studies using aromatase inhibitors, aromatase overexpression in neurons, global aromatase knockout mice, and the recent development of conditional forebrain neuron-specific knockout mice. Collectively, these studies demonstrate a key role of NDE2 in the regulation of synapse and spine density, efficacy of excitatory synaptic transmission and long-term potentiation, and regulation of hippocampal-dependent recognition memory, spatial reference memory, and contextual fear memory. NDE2 is suggested to achieve these effects through estrogen receptor-mediated regulation of rapid kinase signaling and CREB-BDNF signaling pathways, which regulate actin remodeling, as well as transcription, translation, and transport of synaptic proteins critical for synaptic plasticity and function.
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Affiliation(s)
- Darrell W. Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
- Correspondence:
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
| | - Jing Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA;
| | - Gangadhara R. Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health, San Antonio, TX 78229, USA; (G.R.S.); (U.P.P.); (R.R.T.); (R.K.V.)
| | - Uday P. Pratap
- Department of Obstetrics and Gynecology, University of Texas Health, San Antonio, TX 78229, USA; (G.R.S.); (U.P.P.); (R.R.T.); (R.K.V.)
| | - Quanguang Zhang
- Department of Neurology, Louisiana State University Health, Shreveport, LA 71103, USA;
| | - Rajeshwar R. Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health, San Antonio, TX 78229, USA; (G.R.S.); (U.P.P.); (R.R.T.); (R.K.V.)
| | - Ratna K. Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health, San Antonio, TX 78229, USA; (G.R.S.); (U.P.P.); (R.R.T.); (R.K.V.)
- Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX 78229, USA
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8
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Azcoitia I, Mendez P, Garcia-Segura LM. Aromatase in the Human Brain. ANDROGENS: CLINICAL RESEARCH AND THERAPEUTICS 2021; 2:189-202. [PMID: 35024691 PMCID: PMC8744447 DOI: 10.1089/andro.2021.0007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 06/20/2021] [Indexed: 11/30/2022]
Abstract
The aromatase cytochrome P450 (P450arom) enzyme, or estrogen synthase, which is coded by the CYP19A1 gene, is widely expressed in a subpopulation of excitatory and inhibitory neurons, astrocytes, and other cell types in the human brain. Experimental studies in laboratory animals indicate a prominent role of brain aromatization of androgens to estrogens in regulating different brain functions. However, the consequences of aromatase expression in the human brain remain poorly understood. Here, we summarize the current knowledge about aromatase expression in the human brain, abundant in the thalamus, amygdala, hypothalamus, cortex, and hippocampus and discuss its role in the regulation of sensory integration, body homeostasis, social behavior, cognition, language, and integrative functions. Since brain aromatase is affected by neurodegenerative conditions and may participate in sex-specific manifestations of autism spectrum disorders, major depressive disorder, multiple sclerosis, stroke, and Alzheimer's disease, we discuss future avenues for research and potential clinical and therapeutic implications of the expression of aromatase in the human brain.
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Affiliation(s)
- Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense de Madrid and Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Pablo Mendez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Luis M. Garcia-Segura
- Department of Cell Biology, Faculty of Biology, Universidad Complutense de Madrid and Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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9
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Brann DW, Lu Y, Wang J, Zhang Q, Thakkar R, Sareddy GR, Pratap UP, Tekmal RR, Vadlamudi RK. Brain-derived estrogen and neural function. Neurosci Biobehav Rev 2021; 132:793-817. [PMID: 34823913 PMCID: PMC8816863 DOI: 10.1016/j.neubiorev.2021.11.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023]
Abstract
Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E2) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E2 (BDE2). Much of what we know regarding the functional roles of BDE2 has come from studies using specific inhibitors of the E2 synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E2 (NDE2) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E2 (ADE2) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.
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Affiliation(s)
- Darrell W Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Jing Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Roshni Thakkar
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Gangadhara R Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Uday P Pratap
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Rajeshwar R Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Ratna K Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA; Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX, 78229, USA.
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10
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Ibrahim MMH, Bheemanapally K, Sylvester PW, Briski KP. Norepinephrine Regulation of Adrenergic Receptor Expression, 5' AMP-Activated Protein Kinase Activity, and Glycogen Metabolism and Mass in Male Versus Female Hypothalamic Primary Astrocyte Cultures. ASN Neuro 2021; 12:1759091420974134. [PMID: 33176438 PMCID: PMC7672765 DOI: 10.1177/1759091420974134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Norepinephrine (NE) control of hypothalamic gluco-regulation involves astrocyte-derived energy fuel supply. In male rats, exogenous NE regulates astrocyte glycogen metabolic enzyme expression in vivo through 5’-AMP-activated protein kinase (AMPK)-dependent mechanisms. Current research utilized a rat hypothalamic astrocyte primary culture model to investigate the premise that NE imposes sex-specific direct control of AMPK activity and glycogen mass and metabolism in these glia. In male rats, NE down-regulation of pAMPK correlates with decreased CaMMKB and increased PP1 expression, whereas noradrenergic augmentation of female astrocyte pAMPK may not involve these upstream regulators. NE concentration is a critical determinant of control of hypothalamic astrocyte glycogen enzyme expression, but efficacy varies between sexes. Data show sex variations in glycogen synthase expression and glycogen phosphorylase-brain and –muscle type dose-responsiveness to NE. Narrow dose-dependent NE augmentation of astrocyte glycogen content during energy homeostasis infers that NE maintains, over a broad exposure range, constancy of glycogen content despite possible changes in turnover. In male rats, beta1- and beta2-adrenergic receptor (AR) profiles displayed bi-directional responses to increasing NE doses; female astrocytes exhibited diminished beta1-AR content at low dose exposure, but enhanced beta2-AR expression at high NE dosages. Thus, graded variations in noradrenergic stimulation may modulate astrocyte receptivity to NE in vivo. Sex dimorphic NE regulation of hypothalamic astrocyte AMPK activation and glycogen metabolism may be mediated, in part, by one or more ARs characterized here by divergent sensitivity to this transmitter.
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Affiliation(s)
- Mostafa M H Ibrahim
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, United States
| | - Khaggeswar Bheemanapally
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, United States
| | - Paul W Sylvester
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, United States
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, United States
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11
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Molehin D, Filleur S, Pruitt K. Regulation of aromatase expression: Potential therapeutic insight into breast cancer treatment. Mol Cell Endocrinol 2021; 531:111321. [PMID: 33992735 DOI: 10.1016/j.mce.2021.111321] [Citation(s) in RCA: 6] [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: 11/17/2020] [Revised: 04/14/2021] [Accepted: 05/09/2021] [Indexed: 12/13/2022]
Abstract
Estrogen signaling has been implicated in hormone-dependent breast cancer which constitutes >75% of breast cancer diagnosis and other malignancies. Aromatase, the key enzyme involved in the synthesis of estrogen, is often dysregulated in breast cancers. This has led to the administration of aromatase-inhibitors (AIs), commonly used for hormone-dependent breast cancers. Unfortunately, the increasing development of acquired resistance to the current AIs and modulators of estrogen receptors, following initial disease steadiness, has posed a serious clinical challenge in breast cancer treatment. In this review we highlight historical and recent advances on the transcriptional and post-translational regulation of aromatase in both physiological and pathological contexts. We also discuss the different drug combinations targeting various tumor promoting cell signaling pathways currently being developed and tested both in laboratory settings and in the clinic.
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Affiliation(s)
- Deborah Molehin
- Department of Immunology & Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Stephanie Filleur
- Texas Tech University Health Sciences Center, School of Medicine, Lubbock, TX, USA
| | - Kevin Pruitt
- Department of Immunology & Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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12
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Sex neurosteroids: Hormones made by the brain for the brain. Neurosci Lett 2021; 753:135849. [PMID: 33775739 DOI: 10.1016/j.neulet.2021.135849] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 11/21/2022]
Abstract
In general, hippocampal neurons are capable of synthesizing sex steroids de novo from cholesterol, since the brain is equipped with all the enzymes required for the synthesis of estradiol and testosterone, the end products of sex steroidogenesis. Regarding estradiol, its synthesis in hippocampal neurons is homeostatically controlled by Ca2+ transients and is regulated by GnRH. Locally synthesized estradiol and testosterone maintain synaptic transmission and synaptic connectivity. Remarkably, the neurosteroid estradiol is effective in females, but not in males, and vice versa dihydrotestosterone (DHT) is effective in males, but not in females. Experimentally induced inhibition of estradiol synthesis in females and DHT synthesis in males resp. results in synapse loss, impaired LTP, and downregulation of synaptic proteins. GnRH-induced increase in estradiol synthesis appears to provide a link between the hypothalamus and the hippocampus, which may underlie estrous cyclicity of spine density in the female hippocampus. Hippocampal neurons are sex-dependently differentiated with respect to the responsiveness of hippocampal neurons to sex neurosteroids.
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13
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Meng L, Liu J, Wang C, Ouyang Z, Kuang J, Pang Q, Fan R. Sex-specific oxidative damage effects induced by BPA and its analogs on primary hippocampal neurons attenuated by EGCG. CHEMOSPHERE 2021; 264:128450. [PMID: 33007573 DOI: 10.1016/j.chemosphere.2020.128450] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/31/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
BPA analogs, including bisphenol S (BPS) and bisphenol B (BPB), have been used to replace BPA since it was banned to be added. To investigate whether BPA and its analogs cause oxidative damage effects on primary hippocampal neurons of rats, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), mitochondrial membrane potential (MMP), apoptosis and cell viability assays were conducted after hippocampal neurons exposure to different concentrations of BPA, BPS, and BPB (1, 10, 100 nM and 1, 10, 100 μM). Moreover, the effects of EGCG (5 and 6 μM for male and female, respectively) added on neurons exposed to BPA were assessed. Results showed that 24 h exposure to these bisphenols (BPs) could increase the levels of ROS and contents of MDA, but reduce the activity of SOD significantly. A decline of cell viabilities accompanied with the increasing of apoptosis rates was observed after 7 d exposure to BPs and the reduction of MMP was also observed after 7 d exposure to BPA. Interestingly, BPS has the lower toxicity to hippocampal neurons compared with BPA and BPB. Non-monotonic dose-effect relationships between the concentrations of BPs and the cytotoxic effects were observed, and the effects of BPs on male hippocampal neurons are greater than those of female ones in general. While EGCG can protect neurons free of oxidative damages. In conclusion, the results suggest that BPs may induce sex-specific neurotoxic effects involving oxidative stress, which can be attenuated by EGCG, and males are more sensitive to BPs than females.
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Affiliation(s)
- Lingxue Meng
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jian Liu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Congcong Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Zedong Ouyang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jiahua Kuang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Qihua Pang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
| | - Ruifang Fan
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China; Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, South China Normal University, Guangzhou, 510006, China.
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14
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Briski KP, Ibrahim MMH, Mahmood ASMH, Alshamrani AA. Norepinephrine Regulation of Ventromedial Hypothalamic Nucleus Astrocyte Glycogen Metabolism. Int J Mol Sci 2021; 22:ijms22020759. [PMID: 33451134 PMCID: PMC7828624 DOI: 10.3390/ijms22020759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 12/15/2022] Open
Abstract
The catecholamine norepinephrine (NE) links hindbrain metabolic-sensory neurons with key glucostatic control structures in the brain, including the ventromedial hypothalamic nucleus (VMN). In the brain, the glycogen reserve is maintained within the astrocyte cell compartment as an alternative energy source to blood-derived glucose. VMN astrocytes are direct targets for metabolic stimulus-driven noradrenergic signaling due to their adrenergic receptor expression (AR). The current review discusses recent affirmative evidence that neuro-metabolic stability in the VMN may be shaped by NE influence on astrocyte glycogen metabolism and glycogen-derived substrate fuel supply. Noradrenergic modulation of estrogen receptor (ER) control of VMN glycogen phosphorylase (GP) isoform expression supports the interaction of catecholamine and estradiol signals in shaping the physiological stimulus-specific control of astrocyte glycogen mobilization. Sex-dimorphic NE control of glycogen synthase and GP brain versus muscle type proteins may be due, in part, to the dissimilar noradrenergic governance of astrocyte AR and ER variant profiles in males versus females. Forthcoming advances in the understanding of the molecular mechanistic framework for catecholamine stimulus integration with other regulatory inputs to VMN astrocytes will undoubtedly reveal useful new molecular targets in each sex for glycogen mediated defense of neuronal metabolic equilibrium during neuro-glucopenia.
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15
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Uddin MM, Ibrahim MMH, Briski KP. Sex-dimorphic neuroestradiol regulation of ventromedial hypothalamic nucleus glucoregulatory transmitter and glycogen metabolism enzyme protein expression in the rat. BMC Neurosci 2020; 21:51. [PMID: 33238883 PMCID: PMC7687823 DOI: 10.1186/s12868-020-00598-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022] Open
Abstract
Background Ventromedial hypothalamic nucleus (VMN) gluco-regulatory transmission is subject to sex-specific control by estradiol. The VMN is characterized by high levels of aromatase expression. Methods The aromatase inhibitor letrozole (LZ) was used with high-resolution microdissection/Western blot techniques to address the hypothesis that neuroestradiol exerts sex-dimorphic control of VMN neuronal nitric oxide synthase (nNOS) and glutamate decarboxylase65/67 (GAD) protein expression. Glycogen metabolism impacts VMN nNOS and GAD profiles; here, LZ treatment effects on VMN glycogen synthase (GS) and phosphorylase brain- (GPbb; glucoprivic-sensitive) and muscle (GPmm; norepinephrine-sensitive) variant proteins were examined. Results VMN aromatase protein content was similar between sexes. Intracerebroventricular LZ infusion of testes-intact male and ovariectomized, estradiol-replaced female rats blocked insulin-induced hypoglycemic (IIH) up-regulation of this profile. LZ exerted sex-contingent effects on basal VMN nNOS and GAD expression, but blocked IIH-induced NO stimulation and GAD suppression in each sex. Sex-contingent LZ effects on basal and hypoglycemic patterns of GPbb and GPmm expression occurred at distinctive levels of the VMN. LZ correspondingly down- or up-regulated baseline pyruvate recycling pathway marker protein expression in males (glutaminase) and females (malic enzyme-1), and altered INS effects on those proteins. Conclusions Results infer that neuroestradiol is required in each sex for optimal VMN metabolic transmitter signaling of hypoglycemic energy deficiency. Sex differences in VMN GP variant protein levels and sensitivity to aromatase may correlate with sex-dimorphic glycogen mobilization during this metabolic stress. Neuroestradiol may also exert sex-specific effects on glucogenic amino acid energy yield by actions on distinctive enzyme targets in each sex.
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Affiliation(s)
- Md Main Uddin
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Mostafa M H Ibrahim
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Karen P Briski
- Willis-Knighton Endowed Professor of Pharmacy and Director, School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA.
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16
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Tozzi A, Bellingacci L, Pettorossi VE. Rapid Estrogenic and Androgenic Neurosteroids Effects in the Induction of Long-Term Synaptic Changes: Implication for Early Memory Formation. Front Neurosci 2020; 14:572511. [PMID: 33192257 PMCID: PMC7653679 DOI: 10.3389/fnins.2020.572511] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/21/2020] [Indexed: 11/17/2022] Open
Abstract
Mounting experimental evidence demonstrate that sex neuroactive steroids (neurosteroids) are essential for memory formation. Neurosteroids have a profound impact on the function and structure of neural circuits and their local synthesis is necessary for the induction of both long-term potentiation (LTP) and long-term depression (LTD) of synaptic transmission and for neural spine formation in different areas of the central nervous system (CNS). Several studies demonstrated that in the hippocampus, 17β-estradiol (E2) is necessary for inducing LTP, while 5α-dihydrotestosterone (DHT) is necessary for inducing LTD. This contribution has been proven by administering sex neurosteroids in rodent models and by using blocking agents of their synthesis or of their specific receptors. The general opposite role of sex neurosteroids in synaptic plasticity appears to be dependent on their different local availability in response to low or high frequency of synaptic stimulation, allowing the induction of bidirectional synaptic plasticity. The relevant contribution of these neurosteroids to synaptic plasticity has also been described in other brain regions involved in memory processes such as motor learning, as in the case of the vestibular nuclei, the cerebellum, and the basal ganglia, or as the emotional circuit of the amygdala. The rapid effects of sex neurosteroids on neural synaptic plasticity need the maintenance of a tonic or phasic local steroid synthesis determined by neural activity but might also be influenced by circulating hormones, age, and gender. To disclose the exact mechanisms how sex neurosteroids participate in finely tuning long-term synaptic changes and spine remodeling, further investigation is required.
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Affiliation(s)
- Alessandro Tozzi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Laura Bellingacci
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
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17
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Taxier LR, Gross KS, Frick KM. Oestradiol as a neuromodulator of learning and memory. Nat Rev Neurosci 2020; 21:535-550. [PMID: 32879508 DOI: 10.1038/s41583-020-0362-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2020] [Indexed: 12/24/2022]
Abstract
Although hormones such as glucocorticoids have been broadly accepted in recent decades as general neuromodulators of memory processes, sex steroid hormones such as the potent oestrogen 17β-oestradiol have been less well recognized by the scientific community in this capacity. The predominance of females in studies of oestradiol and memory and the general (but erroneous) perception that oestrogens are 'female' hormones have probably prevented oestradiol from being more widely considered as a key memory modulator in both sexes. Indeed, although considerable evidence supports a crucial role for oestradiol in regulating learning and memory in females, a growing body of literature indicates a similar role in males. This Review discusses the mechanisms of oestradiol signalling and provides an overview of the effects of oestradiol on spatial, object recognition, social and fear memories. Although the primary focus is on data collected in females, effects of oestradiol on memory in males will be discussed, as will sex differences in the molecular mechanisms that regulate oestrogenic modulation of memory, which may have important implications for the development of future cognitive therapeutics.
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Affiliation(s)
- Lisa R Taxier
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Kellie S Gross
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Karyn M Frick
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
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18
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Brandt N, Löffler T, Fester L, Rune GM. Sex-specific features of spine densities in the hippocampus. Sci Rep 2020; 10:11405. [PMID: 32647191 PMCID: PMC7347548 DOI: 10.1038/s41598-020-68371-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 06/18/2020] [Indexed: 01/27/2023] Open
Abstract
Previously, we found that in dissociated hippocampal cultures the proportion of large spines (head diameter ≥ 0.6 μm) was larger in cultures from female than from male animals. In order to rule out that this result is an in vitro phenomenon, we analyzed the density of large spines in fixed hippocampal vibratome sections of Thy1-GFP mice, in which GFP is expressed only in subpopulations of neurons. We compared spine numbers of the four estrus cycle stages in females with those of male mice. Remarkably, total spine numbers did not vary during the estrus cycle, while estrus cyclicity was evident regarding the number of large spines and was highest during diestrus, when estradiol levels start to rise. The average total spine number in females was identical with the spine number in male animals. The density of large spines, however, was significantly lower in male than in female animals in each stage of the estrus cycle. Interestingly, the number of spine apparatuses, a typical feature of large spines, did not differ between the sexes. Accordingly, NMDA-R1 and NMDA-R2A/B expression were lower in the hippocampus and in postsynaptic density fractions of adult male animals than in those of female animals. This difference could already be observed at birth for NMDA-R1, but not for NMDA-R2A/B expression. In dissociated embryonic hippocampal cultures, no difference was seen after 21 days in culture, while the difference was evident in postnatal cultures. Our data indicate that hippocampal neurons are differentiated in a sex-dependent manner, this differentiation being likely to develop during the perinatal period.
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Affiliation(s)
- Nicola Brandt
- Institute of Neuroanatomy, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.,Department of Human Medicine, Division of Anatomy, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129, Oldenburg, Germany
| | - Tobias Löffler
- Institute of Neuroanatomy, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Lars Fester
- Institute of Neuroanatomy, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.,Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Krankenhausstr. 9, 91054, Erlangen, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
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19
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Clements L, Harvey J. Activation of oestrogen receptor α induces a novel form of LTP at hippocampal temporoammonic-CA1 synapses. Br J Pharmacol 2020; 177:642-655. [PMID: 31637699 DOI: 10.1111/bph.14880] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/30/2019] [Accepted: 09/07/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE 17β estradiol (E2) rapidly regulates excitatory synaptic transmission at the classical Schaffer collateral (SC) input to hippocampal CA1 neurons. However, the impact of E2 on excitatory synaptic transmission at the distinct temporoammonic (TA) input to CA1 neurons and the oestrogen receptors involved is less clear. EXPERIMENTAL APPROACH Extracellular recordings were used to monitor excitatory synaptic transmission in hippocampal slices from juvenile male (P11-24) Sprague Dawley rats. Immunocytochemistry combined with confocal microscopy was used to monitor the surface expression of the AMPA receptor (AMPAR) subunit, GluA1 in hippocampal neurons cultured from neonatal (P0-3) rats. KEY RESULTS Here, we show that E2 induces a novel form of LTP at TA-CA1 synapses, an effect mirrored by the ERα agonist, PPT, and blocked by an ERα antagonist. ERα-induced LTP is NMDA receptor (NMDAR)-dependent and involves a postsynaptic expression mechanism that requires PI 3-kinase signalling and synaptic insertion of GluA2-lacking AMPARs. ERα-induced LTP has overlapping expression mechanisms with classical Hebbian LTP, as HFS-induced LTP occluded PPT-induced LTP and vice versa. In addition, activity-dependent LTP was blocked by the ERα antagonist, suggesting that ERα activation is involved in NMDA-LTP at TA-CA1 synapses. CONCLUSION AND IMPLICATIONS ERα induces a novel form of LTP at juvenile male hippocampal TA-CA1 synapses. As TA-CA1 synapses are implicated in episodic memory processes and are an early target for neurodegeneration, these findings have important implications for the role of oestrogens in CNS health and neurodegenerative disease.
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Affiliation(s)
- Leigh Clements
- Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Jenni Harvey
- Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
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20
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Tozzi A, Durante V, Manca P, Di Mauro M, Blasi J, Grassi S, Calabresi P, Kawato S, Pettorossi VE. Bidirectional Synaptic Plasticity Is Driven by Sex Neurosteroids Targeting Estrogen and Androgen Receptors in Hippocampal CA1 Pyramidal Neurons. Front Cell Neurosci 2019; 13:534. [PMID: 31866827 PMCID: PMC6904272 DOI: 10.3389/fncel.2019.00534] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/18/2019] [Indexed: 11/23/2022] Open
Abstract
Neuroactive estrogenic and androgenic steroids influence synaptic transmission, finely modulating synaptic plasticity in several brain regions including the hippocampus. While estrogens facilitate long-term potentiation (LTP), androgens are involved in the induction of long-term depression (LTD) and depotentiation (DP) of synaptic transmission. To examine sex neurosteroid-dependent LTP and LTD in single cells, patch-clamp recordings from hippocampal CA1 pyramidal neurons of male rats and selective antagonists for estrogen receptors (ERs) and androgen (AR) receptors were used. LTP induced by high-frequency stimulation (HFS) depended on activation of ERs since it was prevented by the ER antagonist ICI 182,780 in most of the neurons. Application of the selective antagonists for ERα (MPP) or ERβ (PHTPP) caused a reduction of the LTP amplitude, while these antagonists in combination, prevented LTP completely. LTP was never affected by blocking AR with the specific antagonist flutamide. Conversely, LTD and DP, elicited by low-frequency stimulation (LFS), were impeded by flutamide, but not by ICI 182,780, in most neurons. In few cells, LTD was even reverted to LTP by flutamide. Moreover, the combined application of both ER and AR antagonists completely prevented both LTP and LTD/DP in the same neuron. The current study demonstrates that the activation of ERs is necessary for inducing LTP in hippocampal pyramidal neurons, whereas the activation of ARs is required for LTD and DP. Moreover, both estrogen- and androgen-dependent LTP and LTD can be expressed in the same pyramidal neurons, suggesting that the activation of sex neurosteroids signaling pathways is responsible for bidirectional synaptic plasticity.
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Affiliation(s)
- Alessandro Tozzi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Valentina Durante
- Department of Medicine, Section of Neurological Clinic, "Santa Maria della Misericordia" Hospital, University of Perugia, Perugia, Italy
| | - Paolo Manca
- Department de Patologia i Terapèutica Experimental, Facultat de Medicina, Campus de Bellvitge, Universitat de Barcelona, Barcelona, Spain
| | - Michela Di Mauro
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Juan Blasi
- Department de Patologia i Terapèutica Experimental, Facultat de Medicina, Campus de Bellvitge, Universitat de Barcelona, Barcelona, Spain
| | - Silvarosa Grassi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
| | - Paolo Calabresi
- Department of Medicine, Section of Neurological Clinic, "Santa Maria della Misericordia" Hospital, University of Perugia, Perugia, Italy
| | - Suguru Kawato
- Department of Cognitive Neuroscience, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan.,Department of Biophysics and Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Vito Enrico Pettorossi
- Department of Experimental Medicine, Section of Physiology and Biochemistry, University of Perugia, Perugia, Italy
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21
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Possible Existence of the Hypothalamic-Pituitary-Hippocampal (HPH) Axis: A Reciprocal Relationship Between Hippocampal Specific Neuroestradiol Synthesis and Neuroblastosis in Ageing Brains with Special Reference to Menopause and Neurocognitive Disorders. Neurochem Res 2019; 44:1781-1795. [PMID: 31254250 DOI: 10.1007/s11064-019-02833-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/13/2019] [Accepted: 06/19/2019] [Indexed: 12/18/2022]
Abstract
The hippocampus-derived neuroestradiol plays a major role in neuroplasticity, independent of circulating estradiol that originates from gonads. The response of hypothalamus-pituitary regions towards the synthesis of neuroestradiol in the hippocampus is an emerging scientific concept in cognitive neuroscience. Hippocampal plasticity has been proposed to be regulated via neuroblasts, a major cellular determinant of functional neurogenesis in the adult brain. Defects in differentiation, integration and survival of neuroblasts in the hippocampus appear to be an underlying cause of neurocognitive disorders. Gonadotropin receptors and steroidogenic enzymes have been found to be expressed in neuroblasts in the hippocampus of the brain. However, the reciprocal relationship between hippocampal-specific neuroestradiol synthesis along neuroblastosis and response of pituitary based feedback regulation towards regulation of estradiol level in the hippocampus have not completely been ascertained. Therefore, this conceptual article revisits (1) the cellular basis of neuroestradiol synthesis (2) a potential relationship between neuroestradiol synthesis and neuroblastosis in the hippocampus (3) the possible involvement of aberrant neuroestradiol production with mitochondrial dysfunctions and dyslipidemia in menopause and adult-onset neurodegenerative disorders and (4) provides a hypothesis for the possible existence of the hypothalamic-pituitary-hippocampal (HPH) axis in the adult brain. Eventually, understanding the regulation of hippocampal neurogenesis by abnormal levels of neuroestradiol concentration in association with the feedback regulation of HPH axis might provide additional cues to establish a neuroregenerative therapeutic management for mood swings, depression and cognitive decline in menopause and neurocognitive disorders.
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22
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Pollard KJ, Daniel JM. Nuclear estrogen receptor activation by insulin-like growth factor-1 in Neuro-2A neuroblastoma cells requires endogenous estrogen synthesis and is mediated by mutually repressive MAPK and PI3K cascades. Mol Cell Endocrinol 2019; 490:68-79. [PMID: 30986444 PMCID: PMC6520186 DOI: 10.1016/j.mce.2019.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 02/01/2023]
Abstract
Non-canonical mechanisms of estrogen receptor activation may continue to support women's cognitive health long after cessation of ovarian function. These mechanisms of estrogen receptor activation may include ligand-dependent actions via locally synthesized neuroestrogens and ligand-independent actions via growth factor-dependent activation of intracellular kinase cascades. We tested the hypothesis that ligand-dependent and ligand-independent mechanisms interact to activate nuclear estrogen receptors in the Neuro-2A neuroblastoma cell line in the absence of exogenous estrogens. Transcriptional output of estrogen receptors was measured following treatment with insulin-like growth factor-1 (IGF-1) in the presence of specific inhibitors for mitogen-activated protein kinase (MAPK), phosphoinositde-3 kinase (PI3K), and neuroestrogen synthesis. Results indicate that IGF-1-dependent activation of nuclear estrogen receptors is mediated by MAPK, is opposed PI3K, and requires concomitant endogenous neuroestrogen synthesis. We conclude that both cellular signaling context and endogenous ligand availability are important modulators of ligand-independent nuclear estrogen receptor activation.
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Affiliation(s)
- Kevin J Pollard
- Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA; Neuroscience Program, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA.
| | - Jill M Daniel
- Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA; Neuroscience Program, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA; Department of Psychology, Tulane University, 2007 Percival Stern Hall, New Orleans, LA, 70118, USA
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23
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Detection of estradiol in rat brain tissues: Contribution of local versus systemic production. Psychoneuroendocrinology 2019; 102:84-94. [PMID: 30529907 DOI: 10.1016/j.psyneuen.2018.11.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 11/22/2018] [Accepted: 11/25/2018] [Indexed: 11/24/2022]
Abstract
Estrogens play important roles in regulating brain development, brain function, and behavior. Many studies have evaluated these effects using ovariectomized (OVX) rats or mice with different doses of estrogen replacement, assuming that estradiol levels in all regions of the brain are the same as levels achieved in the serum. It is well known, however, that the brain contains all the enzymes necessary to produce estrogens, and that estrogen levels in the brain are determined by both systemic and local production and are region-specific. The present study conducted a detailed analysis of the relationship between systemic levels of 17-β-estradiol (E2) achieved by estrogen replacement and levels achieved in specific regions of the brain. Levels of E2 were measured in both brain and serum in OVX rats treated with different doses of estradiol benzoate (EB) using a novel and recently validated UPLC-MS/MS method. Results confirmed significantly higher levels of E2 in the brain than in serum in brain regions known to contain aromatase (ARO) activity, both in OVX controls and in rats treated with physiological doses of EB. Additional studies compared the level of E2 and testosterone (T) in the brain and serum between testosterone propionate (TP) treated OVX and male. This demonstrated higher levels of E2 in certain brain regions of males than in TP treated OVX females even though T levels in the brain and serum were similar between the two groups. Studies also demonstrated that the differences between serum and brain levels of E2 can be eliminated by letrozole (ARO inhibitor) treatment, which indicates that the differences are due to local ARO activity. Collectively the results provide a detailed analysis of brain region-specific E2 concentrations in OVX, E2-, and T-treated rats and demonstrate the degree to which these concentrations are ARO-dependent.
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Adverse Effects of Aromatase Inhibition on the Brain and Behavior in a Nonhuman Primate. J Neurosci 2018; 39:918-928. [PMID: 30587540 PMCID: PMC6382974 DOI: 10.1523/jneurosci.0353-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 11/12/2018] [Accepted: 11/17/2018] [Indexed: 01/12/2023] Open
Abstract
Breast cancer patients using aromatase inhibitors (AIs) as an adjuvant therapy often report side effects, including hot flashes, mood changes, and cognitive impairment. Despite long-term use in humans, little is known about the effects of continuous AI administration on the brain and cognition. We used a primate model of human cognitive aging, the common marmoset, to examine the effects of a 4-week daily administration of the AI letrozole (20 μg, p.o.) on cognition, anxiety, thermoregulation, brain estrogen content, and hippocampal pyramidal cell physiology. Letrozole treatment was administered to both male and female marmosets and reduced peripheral levels of estradiol (E2), but unexpectedly increased E2 levels in the hippocampus. Spatial working memory and intrinsic excitability of hippocampal neurons were negatively affected by the treatment possibly due to increased hippocampal E2. While no changes in hypothalamic E2 were observed, thermoregulation was disrupted by letrozole in females only, indicating some impact on hypothalamic activity. These findings suggest adverse effects of AIs on the primate brain and call for new therapies that effectively prevent breast cancer recurrence while minimizing side effects that further compromise quality of life.SIGNIFICANCE STATEMENT Aromatase inhibitors (AIs) are used as an adjuvant therapy for estrogen-receptor-positive breast cancer and are associated with side effects, including hot flashes, depression/anxiety, and memory deficits severe enough for many women to discontinue this life-saving treatment. AIs are also used by men, yet sex differences in the reported side effects have not been systematically studied. We show that AI-treated male and female marmosets exhibit behavioral changes consistent with these CNS symptoms, as well as elevated hippocampal estradiol and compromised hippocampal physiology. These findings illustrate the need for (1) a greater understanding of the precise mechanisms by which AIs impact brain function and (2) the development of new treatment approaches for breast cancer patients that minimize adverse effects on the brain.
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Distal Dendritic Enrichment of HCN1 Channels in Hippocampal CA1 Is Promoted by Estrogen, but Does Not Require Reelin. eNeuro 2018; 5:eN-NWR-0258-18. [PMID: 30406178 PMCID: PMC6220572 DOI: 10.1523/eneuro.0258-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/20/2018] [Accepted: 08/26/2018] [Indexed: 12/28/2022] Open
Abstract
HCN1 compartmentalization in CA1 pyramidal cells, essential for hippocampal information processing, is believed to be controlled by the extracellular matrix protein Reelin. Expression of Reelin, in turn, is stimulated by 17β-estradiol (E2). In this study, we therefore tested whether E2 regulates the compartmentalization of HCN1 in CA1 via Reelin. In organotypic entorhino-hippocampal cultures, we found that E2 promotes HCN1 distal dendritic enrichment via the G protein–coupled estrogen receptor GPER1, but apparently independent of Reelin, because GST-RAP, known to reduce Reelin signaling, did not prevent E2-induced HCN1 enrichment in distal CA1. We therefore re-examined the role of Reelin for the regulation of HCN1 compartmentalization and could not detect effects of reduced Reelin signaling on HCN1 distribution in CA1, either in the (developmental) slice culture model or in tamoxifen-inducible conditional reelin knockout mice during adulthood. We conclude that for HCN1 channel compartmentalization in CA1 pyramidal cells, Reelin is not as essential as previously proposed, and E2 effects on HCN1 distribution in CA1 are mediated by mechanisms that do not involve Reelin. Because HCN1 localization was not altered at different phases of the estrous cycle, gonadally derived estradiol is unlikely to regulate HCN1 channel compartmentalization, while the pattern of immunoreactivity of aromatase, the final enzyme of estradiol synthesis, argues for a role of local hippocampal E2 synthesis.
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Paletta P, Sheppard PAS, Matta R, Ervin KSJ, Choleris E. Rapid effects of estrogens on short-term memory: Possible mechanisms. Horm Behav 2018; 104:88-99. [PMID: 29847771 DOI: 10.1016/j.yhbeh.2018.05.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 01/11/2023]
Abstract
Contribution to Special Issue on Fast effects of steroids. Estrogens affect learning and memory through rapid and delayed mechanisms. Here we review studies on rapid effects on short-term memory. Estradiol rapidly improves social and object recognition memory, spatial memory, and social learning when administered systemically. The dorsal hippocampus mediates estrogen rapid facilitation of object, social and spatial short-term memory. The medial amygdala mediates rapid facilitation of social recognition. The three estrogen receptors, α (ERα), β (ERβ) and the G-protein coupled estrogen receptor (GPER) appear to play different roles depending on the task and brain region. Both ERα and GPER agonists rapidly facilitate short-term social and object recognition and spatial memory when administered systemically or into the dorsal hippocampus and facilitate social recognition in the medial amygdala. Conversely, only GPER can facilitate social learning after systemic treatment and an ERβ agonist only rapidly improved short-term spatial memory when given systemically or into the hippocampus, but also facilitates social recognition in the medial amygdala. Investigations into the mechanisms behind estrogens' rapid effects on short term memory showed an involvement of the extracellular signal-regulated kinase (ERK) and the phosphoinositide 3-kinase (PI3K) kinase pathways. Recent evidence also showed that estrogens interact with the neuropeptide oxytocin in rapidly facilitating social recognition. Estrogens can increase the production and/or release of oxytocin and other neurotransmitters, such as dopamine and acetylcholine. Therefore, it is possible that estrogens' rapid effects on short-term memory may occur through the regulation of various neurotransmitters, although more research is need on these interactions as well as the mechanisms of estrogens' actions on short-term memory.
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Affiliation(s)
- Pietro Paletta
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Paul A S Sheppard
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Richard Matta
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Kelsy S J Ervin
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Elena Choleris
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, ON N1G 2W1, Canada.
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Hojo Y, Kawato S. Neurosteroids in Adult Hippocampus of Male and Female Rodents: Biosynthesis and Actions of Sex Steroids. Front Endocrinol (Lausanne) 2018; 9:183. [PMID: 29740398 PMCID: PMC5925962 DOI: 10.3389/fendo.2018.00183] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/04/2018] [Indexed: 12/13/2022] Open
Abstract
The brain is not only the target of steroid hormones but also is able to locally synthesize steroids de novo. Evidence of the local production of steroids in the brain has been accumulating in various vertebrates, including teleost fish, amphibia, birds, rodents, non-human primates, and humans. In this review, we mainly focus on the local production of sex steroids in the hippocampal neurons of adult rodents (rats and mice), a center for learning and memory. From the data of the hippocampus of adult male rats, hippocampal principal neurons [pyramidal cells in CA1-CA3 and granule cells in dentate gyrus (DG)] have a complete system for biosynthesis of sex steroids. Liquid chromatography with tandem-mass-spectrometry (LC-MS/MS) enabled us to accurately determine the levels of hippocampal sex steroids including 17β-estradiol (17β-E2), testosterone (T), and dihydrotestosterone (DHT), which are much higher than those in blood. Next, we review the steroid synthesis in the hippocampus of female rats, since previous knowledge had been biased toward the data from males. Recently, we clarified that the levels of hippocampal steroids fluctuate in adult female rats across the estrous cycle. Accurate determination of hippocampal steroids at each stage of the estrous cycle is of importance for providing the account for the fluctuation of female hippocampal functions, including spine density, long-term potentiation (LTP) and long-term depression (LTD), and learning and memory. These functional fluctuations in female had been attributed to the level of circulation-derived steroids. LC-MS/MS analysis revealed that the dendritic spine density in CA1 of adult female hippocampus correlates with the levels of hippocampal progesterone and 17β-E2. Finally, we introduce the direct evidence of the role of hippocampus-synthesized steroids in hippocampal function including neurogenesis, LTP, and memory consolidation. Mild exercise (2 week of treadmill running) elevated synthesis of DHT in the hippocampus, but not in the testis, of male rats, resulting in enhancement of neurogenesis in DG. Concerning synaptic plasticity, hippocampus-synthesized E2 is required for LTP induction, whereas hippocampus-synthesized DHT is required for LTD induction. Furthermore, hippocampus-synthesized E2 is involved in memory consolidation tested by object recognition and object placement tasks, both of which are hippocampus-dependent.
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Affiliation(s)
- Yasushi Hojo
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Moroyama, Saitama, Japan
- *Correspondence: Yasushi Hojo,
| | - Suguru Kawato
- Department of Biophysics and Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
- Department of Cognitive Neuroscience, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan
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Rosenfeld CS, Shay DA, Vieira-Potter VJ. Cognitive Effects of Aromatase and Possible Role in Memory Disorders. Front Endocrinol (Lausanne) 2018; 9:610. [PMID: 30386297 PMCID: PMC6199361 DOI: 10.3389/fendo.2018.00610] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/26/2018] [Indexed: 12/14/2022] Open
Abstract
Diverse cognitive functions in many vertebrate species are influenced by local conversion of androgens to 17β-estradiol (E2) by aromatase. This enzyme is highly expressed in various brain regions across species, with some inter-species variation in terms of regional brain expression. Since women with breast cancer and men and women with other disorders are often treated with aromatase inhibitors (AI), these populations might be especially vulnerable to cognitive deficits due to low neuroE2 synthesis, i.e., synthesis of E2 directly within the brain. Animal models have been useful in deciphering aromatase effects on cognitive functions. Consequences of AI administration at various life cycle stages have been assessed on auditory, song processing, and spatial memory in birds and various aspects of cognition in rodent models. Additionally, cognitive deficits have been described in aromatase knockout (ArKO) mice that systemically lack this gene throughout their lifespan. This review will consider evidence to date that AI treatment in male and female rodent models, birds, and humans results in cognitive impairments. How brain aromatase regulates cognitive function throughout the lifespan, and gaps in current knowledge will be considered, along with future directions to better define how aromatase might guide learning and memory from early development through the geriatric period. Better understanding the importance of E2 synthesis on neurobehavioral responses at various ages will likely aid in the discovery of therapeutic strategies to prevent potential cognitive deficits, including Alzheimer's Disease, in individuals treated with AI or those possessing CYP19 gene polymorphisms, as well as cognitive effects of normal aging that may be related to changes in brain aromatase activity.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO, United States
- Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, MO, United States
- Biomedical Sciences, University of Missouri, Columbia, MO, United States
- *Correspondence: Cheryl S. Rosenfeld
| | - Dusti A. Shay
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
| | - Victoria J. Vieira-Potter
- Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
- Victoria J. Vieira-Potter
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Robin G, López JR, Espinal GM, Hulsizer S, Hagerman PJ, Pessah IN. Calcium dysregulation and Cdk5-ATM pathway involved in a mouse model of fragile X-associated tremor/ataxia syndrome. Hum Mol Genet 2017; 26:2649-2666. [PMID: 28444183 PMCID: PMC5886271 DOI: 10.1093/hmg/ddx148] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/06/2017] [Accepted: 04/12/2017] [Indexed: 12/30/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurological disorder that affects premutation carriers with 55-200 CGG-expansion repeats (preCGG) in FMR1, presenting with early alterations in neuronal network formation and function that precede neurodegeneration. Whether intranuclear inclusions containing DNA damage response (DDR) proteins are causally linked to abnormal synaptic function, neuronal growth and survival are unknown. In a mouse that harbors a premutation CGG expansion (preCGG), cortical and hippocampal FMRP expression is moderately reduced from birth through adulthood, with greater FMRP reductions in the soma than in the neurite, despite several-fold elevation of Fmr1 mRNA levels. Resting cytoplasmic calcium concentration ([Ca2+]i) in cultured preCGG hippocampal neurons is chronically elevated, 3-fold compared to Wt; elevated ROS and abnormal glutamatergic responses are detected at 14 DIV. Elevated µ-calpain activity and a higher p25/p35 ratio in the cortex of preCGG young adult mice indicate abnormal Cdk5 regulation. In support, the Cdk5 substrate, ATM, is upregulated by 1.5- to 2-fold at P0 and 6 months in preCGG brain, as is p-Ser1981-ATM. Bax:Bcl-2 is 30% higher in preCGG brain, indicating a greater vulnerability to apoptotic activation. Elevated [Ca2+]i, ROS, and DDR signals are normalized with dantrolene. Chronic [Ca2+]i dysregulation amplifies Cdk5-ATM signaling, possibly linking impaired glutamatergic signaling and DDR to neurodegeneration in preCGG brain.
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Affiliation(s)
- Gaëlle Robin
- Department Molecular Biosciences, School of Veterinary Medicine, Davis, CA, USA
| | - José R. López
- Department Molecular Biosciences, School of Veterinary Medicine, Davis, CA, USA
| | - Glenda M. Espinal
- Department of Biochemistry and Molecular Medicine, UC Davis, Davis, CA 95616, USA
| | - Susan Hulsizer
- Department Molecular Biosciences, School of Veterinary Medicine, Davis, CA, USA
| | - Paul J. Hagerman
- Department of Biochemistry and Molecular Medicine, UC Davis, Davis, CA 95616, USA
- Medical Investigations of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA 95817, USA
| | - Isaac N. Pessah
- Department Molecular Biosciences, School of Veterinary Medicine, Davis, CA, USA
- Medical Investigations of Neurodevelopmental Disorders (MIND) Institute, Sacramento, CA 95817, USA
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Di Mauro M, Tozzi A, Calabresi P, Pettorossi VE, Grassi S. Different synaptic stimulation patterns influence the local androgenic and estrogenic neurosteroid availability triggering hippocampal synaptic plasticity in the male rat. Eur J Neurosci 2017; 45:499-509. [DOI: 10.1111/ejn.13455] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Michela Di Mauro
- Dipartimento di Medicina Sperimentale Sezione di Fisiologia e Biochimica Università di Perugia Via Gambuli 06156 Perugia Italy
| | - Alessandro Tozzi
- Dipartimento di Medicina Sperimentale Sezione di Fisiologia e Biochimica Università di Perugia Via Gambuli 06156 Perugia Italy
- Fondazione Santa Lucia – I.R.C.C.S. Rome Italy
| | - Paolo Calabresi
- Fondazione Santa Lucia – I.R.C.C.S. Rome Italy
- Dipartimento di Medicina Clinica Neurologica Università di Perugia Perugia Italy
| | - Vito Enrico Pettorossi
- Dipartimento di Medicina Sperimentale Sezione di Fisiologia e Biochimica Università di Perugia Via Gambuli 06156 Perugia Italy
| | - Silvarosa Grassi
- Dipartimento di Medicina Sperimentale Sezione di Fisiologia e Biochimica Università di Perugia Via Gambuli 06156 Perugia Italy
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Sex-Dependent Regulation of Aromatase-Mediated Synaptic Plasticity in the Basolateral Amygdala. J Neurosci 2016; 37:1532-1545. [PMID: 28028198 DOI: 10.1523/jneurosci.1532-16.2016] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 11/11/2016] [Accepted: 12/11/2016] [Indexed: 02/01/2023] Open
Abstract
The basolateral amygdala (BLA) integrates sensory input from cortical and subcortical regions, a function that requires marked synaptic plasticity. Here we provide evidence that cytochrome P450 aromatase (AROM), the enzyme converting testosterone to 17β-estradiol (E2), contributes to the regulation of this plasticity in a sex-specific manner. We show that AROM is expressed in the BLA, particularly in the basolateral nucleus (BL), in male and female rodents. Systemic administration of the AROM inhibitor letrozole reduced spine synapse density in the BL of adult female mice but not in the BL of male mice. Similarly, in organotypic corticoamygdalar slice cultures from immature rats, treatment with letrozole significantly reduced spine synapses in the BL only in cultures derived from females. In addition, letrozole sex-specifically altered synaptic properties in the BL: in acute slices from juvenile (prepubertal) female rats, wash-in of letrozole virtually abolished long-term potentiation (LTP), whereas it did not prevent the generation of LTP in the slices from males. Together, these data indicate that neuron-derived E2 modulates synaptic plasticity in rodent BLA sex-dependently. As protein expression levels of AROM, estrogen and androgen receptors did not differ between males and females and were not sex-specifically altered by letrozole, the findings suggest sex-specific mechanisms of E2 signaling.SIGNIFICANCE STATEMENT The basolateral amygdala (BLA) is a key structure of the fear circuit. This research reveals a sexually dimorphic regulation of synaptic plasticity in the BLA involving neuronal aromatase, which produces the neurosteroid 17β-estradiol (E2). As male and female neurons in rodent BLA responded differently to aromatase inhibition both in vivo and in vitro, our findings suggest that E2 signaling in BLA neurons is regulated sex-dependently, presumably via mechanisms that have been established during sexual determination. These findings could be relevant for the understanding of sex differences in mood disorders and of the side effects of cytochrome P450 aromatase inhibitors, which are frequently used for breast cancer therapy.
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32
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Fester L, Zhou L, Ossig C, Labitzke J, Bläute C, Bader M, Vollmer G, Jarry H, Rune GM. Synaptopodin is regulated by aromatase activity. J Neurochem 2016; 140:126-139. [PMID: 27861893 DOI: 10.1111/jnc.13889] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 10/17/2016] [Accepted: 10/28/2016] [Indexed: 01/25/2023]
Abstract
Locally synthesized estradiol plays an important role in synaptic plasticity in the hippocampus. We have previously shown that in hippocampal neurons, activity of the enzyme aromatase, which converts testosterone into estradiol, is reduced via Ca2+ -dependent phosphorylation. Synaptopodin is a highly estrogen responsive protein, and it has been shown that it is an important regulator of synaptic plasticity, mediated by its close association with internal calcium stores. In this study, we show that the expression of synaptopodin is stronger in the hippocampus of female animals than in that of male animals. Phosphorylation of aromatase, using letrozole, however, down-regulates synaptopodin immunohistochemistry in the hippocampus of both male and females. Similarly, in aromatase knock-out mice synaptopodin expression in the hippocampus is reduced sex independently. Using primary-dissociated hippocampal neurons, we found that evoked release of Ca2+ from internal stores down-regulates aromatase activity, which is paralleled by reduced expression of synaptopodin. Opposite effects were achieved after inhibition of the release. Calcium-dependent regulation of synaptopodin expression was abolished when the control of aromatase activity by the Ca2+ transients was disrupted. Our data suggest that the regulation of aromatase activity by Ca2+ transients in neurons contributes to synaptic plasticity in the hippocampus of male and female animals as an on-site regulatory mechanism.
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Affiliation(s)
- Lars Fester
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Lepu Zhou
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Christiana Ossig
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Jan Labitzke
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Corinna Bläute
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Manuela Bader
- Department of Biology, Technische Universität Dresden, Dresden, Germany
| | - Günter Vollmer
- Department of Biology, Technische Universität Dresden, Dresden, Germany
| | - Hubertus Jarry
- Department of Experimental Endocrinology, University of Goettingen, Goettingen, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
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Yang L, Zhou B, Zha J, Wang Z. Mechanistic study of chlordecone-induced endocrine disruption: Based on an adverse outcome pathway network. CHEMOSPHERE 2016; 161:372-381. [PMID: 27448318 DOI: 10.1016/j.chemosphere.2016.07.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/03/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
The adverse outcome pathway (AOP) framework could be helpful for chemical risk assessment and mechanistic research. The aim of the present study was to unravel the mechanism of chlordecone-induced endocrine disruption by illustrating the main molecular initiating event (MIE)/perturbations responsible for the observed effects. In silico simulations were performed to predict the MIE(s), and the results pointed to agonistic interaction with estrogen receptors (ERα, ERβ), androgen receptor (AR), cytochrome P450 (CYP19A) by chlordecone. In vivo endocrine disruptions were evaluated in rare minnow (Gobiocypris rarus) exposed to 0.01, 0.1, 1 and 10 μg L(-1) chlordecone from 2 h post-fertilization until sexually mature. In the females, increases of vitellogenin (vtg) mRNA levels in liver and gonad, plasma estradiol (E2), testosterone (T) and E2/T, and renalsomatic index confirmed the role of agonism of ER and CYP19A as MIEs, but the decreased gonadosomatic index, degenerated ovaries as well as the feed-forward response pointed to other potential but important MIEs and corresponding AOPs. In the males, increased E2/T ratio, increased testis vtg mRNA levels and occurrence of intersex confirmed the roles of agonism of ERα and CYP19A as main MIEs in chlordecone-induced endocrine disruptions. Our results also fetches out the limit of AOPs in predicting the adverse outcomes and explaining the mechanism of chemicals at present, thus reflected a critical need for expanding AOPs and AOP network before using it in chemical risk assessment.
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Affiliation(s)
- Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Jinmiao Zha
- State Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Zijian Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China
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