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Deng S, Yi P, Xu M, Yi Q, Feng J. Dysfunctional gene splicing in glucose metabolism may contribute to Alzheimer's disease. Chin Med J (Engl) 2023; 136:666-675. [PMID: 35830275 PMCID: PMC10129079 DOI: 10.1097/cm9.0000000000002214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT The glucose metabolism is crucial for sustained brain activity as it provides energy and is a carbon source for multiple biomacromolecules; glucose metabolism decreases dramatically in Alzheimer's disease (AD) and may be a fundamental cause for its development. Recent studies reveal that the alternative splicing events of certain genes effectively regulate several processes in glucose metabolism including insulin receptor, insulin-degrading enzyme, pyruvate kinase M, receptor for advanced glycation endproducts, and others, thereby, influencing glucose uptake, glycolysis, and advanced glycation end-products-mediated signaling pathways. Indeed, the discovery of aberrant alternative splicing that changes the proteomic diversity and protein activity in glucose metabolism has been pivotal in our understanding of AD development. In this review, we summarize the alternative splicing events of the glucose metabolism-related genes in AD pathology and highlight the crucial regulatory roles of splicing factors in the alternative splicing process. We also discuss the emerging therapeutic approaches for targeting splicing factors for AD treatment.
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Affiliation(s)
- Shengfeng Deng
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Peng Yi
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Mingliang Xu
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Qian Yi
- Department of Physiology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Jianguo Feng
- Laboratory of Anesthesiology, Department of Anesthesiology, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, China
- Affiliated Xinhui Hospital, Southern Medical University (People's Hospital of Xinhui District), Jiangmen, Guangdong 529100, China
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Feng C, Ji P, Luo P, Xu J. Estrogen-Mediated MicroRNA-101-3p Expression Represses Hyaluronan Synthase 2 in Synovial Fibroblasts From Idiopathic Condylar Resorption Patients. J Oral Maxillofac Surg 2019; 77:1582-1593. [PMID: 30904552 DOI: 10.1016/j.joms.2019.02.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 12/19/2022]
Abstract
PURPOSE Idiopathic condylar resorption (ICR) is an aggressive form of osteoarthritis that is frequently observed in adolescent female patients. We hypothesized that an estrogen-mediated pathway may contribute to ICR development. MATERIALS AND METHODS An enzyme-linked immunosorbent assay was used to detect the levels of estradiol (E2) and hyaluronan in synovial fluid. Immunohistochemistry, real-time polymerase chain reaction, and Western blotting were used to detect the expression of microRNAs (miRNAs) and related genes after transfection of miRNA-101-3p mimics, inhibitor, or short interfering RNA into synovial fibroblasts. Dual-luciferase activity was determined to identify the direct effect of miRNA-101-3p on hyaluronan synthase 2 (HAS2). Linear regression analysis, the nonparametric Mann-Whitney U test, the Student t test, and 1-way analysis of variance were carried out to analyze the results of each group. RESULTS The relationship between hyaluronan and E2 was negatively correlated in synovial fluid (Pearson r = -0.3179, P = .0230). Among the screened miRNAs, miRNA-101-3p was the most overexpressed in ICR. E2 mostly upregulated the expression of miRNA-101-3p at a dose of 10 nmol/L 12 hours after transfection in synovial fibroblasts of patients with ICR. However, E2 induction of miRNA-101-3p expression was significantly repressed by estrogen receptor α interference (P = 0.0286). The dual-luciferase assay showed that miRNA-101-3p regulated the expression of HAS2 by directly targeting its 3' untranslated region. CONCLUSIONS We speculate that E2 regulates HAS2 expression by targeting miRNA-101-3p in synovial fibroblasts of patients with ICR. Thus, the E2-miRNA-101-3p-HAS2 pathway might play an important role in the pathogenesis of ICR.
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Affiliation(s)
- Chi Feng
- Resident, Department of Oral and Maxillofacial Surgery, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Ping Ji
- Professor, Department of Oral and Maxillofacial Surgery, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Ping Luo
- Resident, Department of Oral and Maxillofacial Surgery, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Jie Xu
- Resident, Department of Oral and Maxillofacial Surgery, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
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Yesufu A, Bandelow S, Hogervorst E. Meta-analyses of the effect of hormone treatment on cognitive function in postmenopausal women. ACTA ACUST UNITED AC 2012; 3:173-94. [PMID: 19803851 DOI: 10.2217/17455057.3.2.173] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As we age, most of us experience a certain degree of cognitive decline. In most cases, this decline is gradual. However, in some cases, cognitive impairment is so severe that it can be classified as dementia and this impacts greatly on activities of daily living. Alzheimer's disease, the most common form of dementia, has been linked to the reduction in estrogen levels that comes with aging. More specifically, many researchers have hypothesized that estrogen, and hence estrogen replacement via hormone therapy, could protect against cognitive decline in women. However, recent randomized, controlled trials did not reflect this. In fact, some reports showed that hormone therapy could have detrimental effects on cognitive function in older postmenopausal women. The most publicized of these has been the Women's Health Initiative Memory Study. Studies have thus yielded conflicting results and conclusions. The reasons for this may be due to a number of factors, such as the age of participants, the time of hormone therapy onset ('window of opportunity' theory), type of treatment, type of menopause (surgical or natural) and, possibly, genetic risk factors. We performed quantitative and qualitative meta-analyses and reviewed each of these factors in detail. The future may lie in combining these factors in order to fully understand the potential mechanisms behind estrogen and its effect on cognition.
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Affiliation(s)
- Amina Yesufu
- Department of Human Sciences, Loughborough University, LE11 3TU, UK.
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Using predictors of hormone therapy use to model the healthy user bias: how does healthy user status influence cognitive effects of hormone therapy? Menopause 2012; 19:524-33. [PMID: 22207317 DOI: 10.1097/gme.0b013e318238ff2c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE This study investigated the phenomenon known as the healthy user bias by equating hormone therapy (HT) use (past or current) with healthy user status. METHODS Data from the Survey of Midlife in the United States were used to identify the predictors of HT use. The unique Survey of Midlife in the United States data include psychological, demographic, health-related, and behavioral variables as well as history of HT use. Predictors of HT use were combined to derive propensity scores, describing the likelihood that a woman was an HT user, based on her psychological, demographic, physical, and behavioral profile (ie, likelihood of being a healthy user) as opposed to her actual use of HT. Finally, cognitive performance on an executive function test was examined in women stratified by propensity score. RESULTS Using a multiple logistic regression model, nine variables emerged as predictors of HT use. The nine variables were used to estimate the propensity or conditional probability of using HT for each subject; resultant propensity scores were ranked and divided into tertiles. Women in the highest tertile demonstrated shorter median response latencies on a test of executive function than did women who did not use HT. CONCLUSIONS From an array of psychological, medical, and behavioral variables, nine emerged as predictors of HT use. If validated, these features may serve as a means of estimating the phenomenon known as healthy user bias. Moreover, these data suggest that the degree to which a woman fits a model of a healthy user may influence cognitive response to HT.
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Erickson KI, Voss MW, Prakash RS, Chaddock L, Kramer AF. A cross-sectional study of hormone treatment and hippocampal volume in postmenopausal women: evidence for a limited window of opportunity. Neuropsychology 2010; 24:68-76. [PMID: 20063947 DOI: 10.1037/a0017292] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The influence of hormone treatment on brain and cognition in postmenopausal women has been a controversial topic. Contradictory patterns of results have prompted speculation that a critical period, or limited window of opportunity, exists for hormone treatment to protect against neurocognitive. In this cross-sectional study of 102 postmenopausal women, we examined whether hippocampal, amygdala, or caudate nucleus volumes and spatial memory performance were related to the interval between menopause and the initiation of hormone treatment. Consistent with a critical period hypothesis, we found that shorter intervals between menopause and the initiation of hormone treatment were associated with larger hippocampal volumes compared with longer intervals between menopause and treatment initiation. Initiation of hormone treatment at the time of menopause was also associated with larger hippocampal volumes when compared with peers who had never used hormone treatment. Furthermore, these effects were independent from potentially confounding factors such as age, years of education, the duration of hormone treatment, current or past use of hormone therapy, the type of therapy, and age at menopause. Larger hippocampal volumes in women who initiated hormone treatment at the time of menopause failed to translate to improved spatial memory performance. There was no relationship between timing of hormone initiation, spatial memory performance, and amygdala or caudate nucleus volume. Our results provide support for a limited window of opportunity for hormone treatment to influence hippocampal volume, yet the degree to which these effects translate to improved memory performance is uncertain.
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Affiliation(s)
- Kirk I Erickson
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
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Wharton W, Dowling M, Khosropour CM, Carlsson C, Asthana S, Gleason CE. Cognitive benefits of hormone therapy: cardiovascular factors and healthy-user bias. Maturitas 2009; 64:182-7. [PMID: 19879073 DOI: 10.1016/j.maturitas.2009.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 09/18/2009] [Accepted: 09/22/2009] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The Women's Health Initiative (WHI) study and its ancillary Memory Study (WHIMS) revealed increased rates of cardiovascular risk, cognitive decline and dementia with opposed conjugated equine estrogens (CEE). As a result, previously accepted observational data suggesting cardiovascular and cognitive benefits and reduced risk for dementia with hormone therapy (HT) were largely attributed to 'healthy-user' bias. The present observational, community-based, case-controlled study examined the 'healthy-user' bias theory by comparing cognitive task performance in two groups of postmenopausal women, who were either HT users or non-users. DESIGN Participants were 213 non-demented, postmenopausal women residing in the community and in assisted-living facilities who completed a self-report health questionnaire and underwent a 1-h cognitive test battery. To study the independent contribution of variables in the prediction of cognitive performance, we employed a series of hierarchical regression models adding terms in three stages. The first stage included only HT, the second stage added demographics, and the last stage added alcohol, depression and a cardiovascular risk factor (CVRF) composite derived from a confirmatory factor analysis. The CVRF composite consisted of: stroke, diabetes, hypertension, and hypercholesterolemia. RESULTS Although independent samples t-tests revealed no statistically significant differences in the CVRF composite and its individual components between the two groups, HT users tended to possess fewer CVRF than non-users. Conversely, HT users were younger and more educated than non-users. HT users outperformed non-users on 7/9 cognitive variables. The full regression model controlling for CVRF, demographic variables, and mood showed HT users outperformed non-users on measures of verbal memory and abstract reasoning. CONCLUSIONS While there is some evidence HT users possess fewer preexisting CVRF than non-users, the observed positive association between HT and cognition is not completely explained by this trend.
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Affiliation(s)
- Whitney Wharton
- School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA.
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Zhou J, Qu F, Nan R, Tang D. The effect of chinese medicinal herbs in relieving menopausal symptoms in ovariectomized chinese women. Explore (NY) 2008; 3:478-84. [PMID: 17905357 DOI: 10.1016/j.explore.2007.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of this study was to explore the effect of a defined formula of Chinese medicinal herbs, GengNianAn (GNA, also called menopausal symptom-relieving formula) formula in relieving menopausal symptoms in ovariectomized women. DESIGN A double-blind randomized placebo-controlled trial. METHOD Between May 2003 and June 2006, 69 ovariectomized Chinese women were recruited to complete 12 weeks of intervention with either a defined formula of GNA (n = 36) or placebo (n = 33) taken twice daily as a beverage. Clinical symptoms were assessed by the modified Kupperman scale. The levels of venous blood serum follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E(2)), and the maturation index (MI) of vaginal epithelial cells were respectively measured. RESULTS There existed significant differences between the two groups in the total Kupperman scoring, MI of vaginal exfoliative cells, and the levels of FSH, LH, and E(2) after treatment (P < .05). CONCLUSION Chinese herbs may be a useful alternative treatment for ovariectomized women suffering from menopausal symptoms, who are unable or do not want to receive hormone replacement therapy (HRT).
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Affiliation(s)
- Jue Zhou
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People's Republic of China
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Chen G, Li HM, Chen YR, Gu XS, Duan S. Decreased estradiol release from astrocytes contributes to the neurodegeneration in a mouse model of Niemann-Pick disease type C. Glia 2007; 55:1509-18. [PMID: 17705200 DOI: 10.1002/glia.20563] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Niemann-Pick disease type C (NPC) is a deadly neurodegenerative disease often caused by mutation in a gene called NPC1, which results in the accumulation of unesterified cholesterol and glycosphingolipids in the endosomal-lysosomal system. Most studies on the mechanisms of neurodegeneration in NPC have focused on neurons. However, the possibility also exists that NPC1 affects neuronal functions indirectly by acting on other cells that are intimately interacting with neurons. In this study, using a heterotypic neuron-glia coculture system, we found that wild-type neurons cultured on a layer of NPC1-/- astrocytes showed decreased neurite growth compared with those cultured on wild-type astrocytes. RT-PCR and immunohistochemical assessments showed significantly lower expression of neurosteroid enzymes and StAR (steroidogenic acute regulatory protein) in NPC1-/- astrocyte cultures than in wild-type cultures. Furthermore, a reduced level of estradiol was measured from both astrocyte culture medium and whole brains from NPC1-/- mice. Administration of 17beta-estradiol to neonatal NPC1-/- mice significantly delayed the onset of neurological symptoms, increased Purkinje cell survival, and extended the animals' life span. Our findings suggest that astrocyte dysfunction contributes to the neurodegeneration of NPC and estradiol treatment may be useful in ameliorating progression of the disease.
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Affiliation(s)
- Gang Chen
- Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Schupf N, Winsten S, Patel B, Pang D, Ferin M, Zigman WB, Silverman W, Mayeux R. Bioavailable estradiol and age at onset of Alzheimer's disease in postmenopausal women with Down syndrome. Neurosci Lett 2006; 406:298-302. [PMID: 16926067 DOI: 10.1016/j.neulet.2006.07.062] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/10/2006] [Accepted: 07/28/2006] [Indexed: 11/20/2022]
Abstract
Several lines of evidence suggest that loss of estrogen after menopause may play a role in the cognitive declines associated with Alzheimer's disease (AD). Women with Down syndrome (DS) experience early onset of both menopause and AD. This timing provides a model to examine the influence of endogenous estrogen deficiency on risk of AD. We hypothesized that low serum levels of bioavailable estradiol (E2) would be associated with increased risk of AD. One hundred and nineteen postmenopausal women with DS, 42-59 years of age, were ascertained through the New York State developmental disability service system and followed at 18-month intervals. Information from cognitive assessments, caregiver interviews, medical record review and neurological examination was used to establish the diagnosis of dementia. Women with DS who developed AD had lower levels of bioavailable E2, lower levels of total estradiol, higher levels of sex-hormone binding globulin, and lower levels of dehydroepiandrosterone sulfate at baseline than women who remained dementia free over the course of follow-up. Women who had low levels of bioavailable E2 at baseline were four times as likely to develop AD (HR=4.1, 95% CI: 1.2-13.9) and developed AD, on average, 3 years earlier, than those with high levels of bioavailable E2, after adjustment for age, level of mental retardation, ethnicity, body mass index, history of hypothyroidism or depression and the presence of the apolipoprotein varepsilon4 allele. Our findings support the hypothesis that reductions in estrogen following menopause can contribute to the cascade of pathological processes leading to AD.
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Affiliation(s)
- Nicole Schupf
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA.
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Brinton RD. Investigative models for determining hormone therapy-induced outcomes in brain: evidence in support of a healthy cell bias of estrogen action. Ann N Y Acad Sci 2006; 1052:57-74. [PMID: 16024751 DOI: 10.1196/annals.1347.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The profound disparities between the largely positive basic science findings of gonadal steroid action in brain and the adverse outcomes of recent hormone therapy clinical trials in women who are either aged postmenopausal or postmenopausal with Alzheimer's disease have led to an intense reassessment of gonadal hormone action and the model systems used in basic and clinical science. The power of model systems is their predictive validity for a target population--in this case, menopausal women considering the health benefits and risks of hormone therapy. Analysis of the model systems used across the basic to clinical research continuum separate into two broad classes: those that use prevention interventions in healthy organisms and those that use hormone interventions in organisms with compromised neurological function. Basic science analyses that led to elucidation of the neurotrophic and neuroprotective effects of estrogen and the underlying mechanisms of action typically used a prevention-based experimental paradigm. This paradigm relies on healthy neurons/brains/animals/humans as the starting foundation followed by exposure to estrogen/hormone followed by exposure to neurodegenerative insult. The prevention paradigm in basic science analyses parallels the analyses of Sherwin and colleagues (Psychoneuroendocrinology 13: 345-357, 1988), who investigated the cognitive impact of estrogen therapy in women with surgical- or pharmacological-induced menopause. Observational retrospective and prospective studies are also consistent with the healthy cell bias of estrogen action and a prevention paradigm of estrogen or hormone therapy intervention. For the most part, the epidemiological observational data indicate reduction in the risk of Alzheimer's disease in women who began estrogen or hormone therapy at the time of the menopause. In contrast, studies that fall within the second class, hormone intervention in organisms with compromised neurological function--that is, a treatment paradigm--exhibit a mixed profile. In a randomized double-blind clinical trial of estrogen therapy in a cohort of women aged 72 or more years and diagnosed with Alzheimer's disease, estrogen therapy resulted in a modest benefit in the short term (2 months) and adverse progression of disease in the long term (12 months). In the Women's Health Initiative Memory Study (WHIMS) cohort of women 65 or more years of age, with no indicators of neurological disease but with variable health status, estrogen and hormone therapy for 5 years increased the risk of developing Alzheimer's disease. These data would suggest that as the continuum of neurological health progresses from healthy to unhealthy, so too do the benefits of estrogen or hormone therapy. If neurons are healthy at the time of estrogen exposure, their response to estrogen is beneficial for both neurological function and survival. In contrast, if neurological health is compromised, estrogen exposure over time exacerbates neurological demise. Based on these and other data, a hypothesis of a healthy cell bias of gonadal hormone action is put forth. The healthy cell bias of estrogen action hypothesis provides a lens through which to assess the disparities in outcomes across the domains of scientific inquiry and to access future applications of estrogen and hormone therapeutic interventions.
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Affiliation(s)
- Roberta Diaz Brinton
- Department of Molecular Pharmacology and Toxicology, School of Pharmacy, University of Southern California, 1985 Zonal Ave., Los Angeles, CA 90089-9121, USA.
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Zhao L, Brinton RD. Select estrogens within the complex formulation of conjugated equine estrogens (Premarin) are protective against neurodegenerative insults: implications for a composition of estrogen therapy to promote neuronal function and prevent Alzheimer's disease. BMC Neurosci 2006; 7:24. [PMID: 16533397 PMCID: PMC1421415 DOI: 10.1186/1471-2202-7-24] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Accepted: 03/13/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Results of the Women's Health Initiative Memory Study (WHIMS) raised concerns regarding the timing and formulation of hormone interventions. Conjugated equine estrogens (CEE), used as the estrogen therapy in the WHIMS trial, is a complex formulation containing multiple estrogens, including several not secreted by human ovaries, as well as other biologically active steroids. Although the full spectrum of estrogenic components present in CEE has not yet been resolved, 10 estrogens have been identified. In the present study, we sought to determine which estrogenic components, at concentrations commensurate with their plasma levels achieved following a single oral dose of 0.625 mg CEE (the dose used in the WHIMS trial) in women, are neuroprotective and whether combinations of those neuroprotective estrogens provide added benefit. Further, we sought, through computer-aided modeling analyses, to investigate the potential correlation of the molecular mechanisms that conferred estrogen neuroprotection with estrogen interactions with the estrogen receptor (ER). RESULTS Cultured basal forebrain neurons were exposed to either beta-amyloid(25-35) or excitotoxic glutamate with or without pretreatment with estrogens followed by neuroprotection analyses. Three indicators of neuroprotection that rely on different aspects of neuronal damage and viability, LDH release, intracellular ATP level and MTT formazan formation, were used to assess neuroprotective efficacy. Results of these analyses indicate that the estrogens, 17alpha-estradiol, 17beta-estradiol, equilin, 17alpha-dihydroequilin, equilinen, 17alpha-dihydroequilenin, 17beta-dihydroequilenin, and Delta8,9-dehydroestrone were each significantly neuroprotective in reducing neuronal plasma membrane damage induced by glutamate excitotoxicity. Of these estrogens, 17beta-estradiol and Delta8,9-dehydroestrone were effective in protecting neurons against beta-amyloid25-35-induced intracellular ATP decline. Coadministration of two out of three neuroprotective estrogens, 17beta-estradiol, equilin and Delta8,9-dehydroestrone, exerted greater neuroprotective efficacy than individual estrogens. Computer-aided analyses to determine structure/function relationships between the estrogenic structures and their neuroprotective activity revealed that the predicted intermolecular interactions of estrogen analogues with ER correlate to their overall neuroprotective efficacy. CONCLUSION The present study provides the first documentation of the neuroprotective profile of individual estrogens contained within the complex formulation of CEE at concentrations commensurate with their plasma levels achieved after an oral administration of 0.625 mg CEE in women. Our analyses demonstrate that select estrogens within the complex formulation of CEE contribute to its neuroprotective efficacy. Moreover, our data predict that the magnitude of neuroprotection induced by individual estrogens at relatively low concentrations may be clinically undetectable and ineffective, whereas, a combination of select neuroprotective estrogens could provide an increased and clinically meaningful efficacy. More importantly, these data suggest a strategy for determining neurological efficacy and rational design and development of a composition of estrogen therapy to alleviate climacteric symptoms, promote neurological health, and prevent age-related neurodegeneration, such as AD, in postmenopausal women.
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Affiliation(s)
- Liqin Zhao
- Department of Molecular Pharmacology and Toxicology, Norris Foundation Laboratory for Neuroscience Research, University of Southern California, Pharmaceutical Sciences Center, Los Angeles, CA 90089, USA
| | - Roberta Diaz Brinton
- Department of Molecular Pharmacology and Toxicology, Norris Foundation Laboratory for Neuroscience Research, University of Southern California, Pharmaceutical Sciences Center, Los Angeles, CA 90089, USA
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Mahady GB. Black cohosh (Actaea/Cimicifuga racemosa): review of the clinical data for safety and efficacy in menopausal symptoms. ACTA ACUST UNITED AC 2005; 4:177-84. [PMID: 15898823 DOI: 10.2165/00024677-200504030-00006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Since the publication of the results of the Women's Health Initiative that described the risks of hormone replacement therapy, many women are actively seeking alternative treatments for menopausal symptoms. Black cohosh (Actaea racemosa, syn. Cimicifuga racemosa) is one such alternative that has been used in the US for over 100 years. To date only two cimicifuga extracts have been tested clinically, and the current recommended dosage is 40-80 mg/day. Review of the published clinical data suggests that cimicifuga may be useful for the treatment of menopausal symptoms, such as hot flashes, profuse sweating, insomnia, and anxiety. However, the methodology used in most of the trials is poor and further clinical assessment of cimicifuga is needed. In terms of safety, transient adverse events such as nausea, vomiting, headaches, dizziness, mastalgia, and weight gain have been observed in clinical trials. A few cases of hepatotoxicity have been reported, but a direct association with the ingestion of cimicifuga has not been demonstrated. The most recent data suggest that cimicifuga is not estrogenic.
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Affiliation(s)
- Gail B Mahady
- Department of Pharmacy Practice, UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences, College of Pharmacy, University of Illinois, Chicago, Illinois 60612, USA.
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Zhao L, O'Neill K, Diaz Brinton R. Selective estrogen receptor modulators (SERMs) for the brain: current status and remaining challenges for developing NeuroSERMs. ACTA ACUST UNITED AC 2005; 49:472-93. [PMID: 16269315 DOI: 10.1016/j.brainresrev.2005.01.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 12/21/2004] [Accepted: 01/19/2005] [Indexed: 11/15/2022]
Abstract
Multiple issues regarding the efficacy of estrogen action in the brain remain unresolved. These include the timing, formulation and duration of the therapy intervention. Moreover, issues of thrombotic and neoplastic risks must be factored into the design of estrogen alternatives developed to prevent age-associated neurodegenerative disorders, as well as other climacteric symptoms such as hot flush and sleep dysfunction. One strategy to address these issues is to develop molecules that selectively target and activate estrogen mechanisms of action in the brain while avoiding activation of estrogen receptors peripheral to the brain, particularly in reproductive organs. An overview of recent advances in our understanding of the molecular mechanisms of estrogen action is discussed in the context of designing an efficacious NeuroSERM that will activate cellular, biochemical and genomic events required for the promotion of memory function and neuronal survival. Pharmacological analyses of estrogen receptor subtypes and the case for a membrane-associated estrogen receptor splice variant in mediating these mechanisms are provided along with a summary of the activation profiles of existing clinically relevant estrogen alternatives or SERMs in neurons. Results of these endeavors have yielded insights into strategies for developing novel molecules with NeuroSERM potential in order to prevent brain related climacteric symptoms and neurodegenerative diseases.
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Affiliation(s)
- Liqin Zhao
- Department of Molecular Pharmacology and Toxicology and the Program in Neuroscience, School of Pharmacy, University of Southern California, Pharmaceutical Sciences Center, Los Angeles, CA 90089, USA
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Mickley KR, Dluzen DE. Dose-response effects of estrogen and tamoxifen upon methamphetamine-induced behavioral responses and neurotoxicity of the nigrostriatal dopaminergic system in female mice. Neuroendocrinology 2004; 79:305-16. [PMID: 15256808 DOI: 10.1159/000079710] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Accepted: 05/17/2004] [Indexed: 11/19/2022]
Abstract
In the present experiment we evaluated the dose-response effects of estrogen (estradiol benzoate; EB) and tamoxifen (TMX) in modulating the acute behavioral and chronic effects of methamphetamine (MA) upon the nigrostriatal dopaminergic (NSDA) system in ovariectomized (OVX) mice. EB over a range of doses from 1-40 microg resulted in a neuroprotective effect upon the NSDA system as defined by both a preservation of striatal dopamine (DA) concentrations and a decrease in DOPAC/DA ratios. Interestingly, the neuroprotective effect of the 1-microg EB dose occurred in the absence of any statistically significant effect upon the bioassay parameter of uterine weight. With the exception of an increase in stereotypy time as a response to the 40-microg dose, EB at any of the doses tested failed to alter any acute behavioral responses evoked by MA. In response to TMX, a statistically significant NSDA neuroprotectant response was obtained for DOPAC/DA ratios, but not DA concentrations, to doses ranging from 12.5 to 500 microg. No statistically significant effects upon uterine weights were obtained for any of the doses of TMX tested. Behaviorally, TMX at 500 microg had the effect of increasing the amount of time spent in the center of the cage. Taken together these results demonstrate: (1) EB and TMX at relatively low doses can exert a neuroprotective effect against MA; (2) these neuroprotective effects of EB and TMX can occur in the absence of an effect upon the bioassay parameter--uterine weights; (3) the parameter of DOPAC/DA ratio may indicate a more sensitive index of NSDA neuroprotection, and (4) modulatory effects of EB and TMX upon acute behavioral responses of the NSDA system to MA can be distinguished from their neuroprotective actions.
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Affiliation(s)
- Katherine R Mickley
- Department of Anatomy, Northeastern Ohio Universities College of Medicine, Rootstown, Ohio, USA
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Martin S, Jones M, Simpson E, van den Buuse M. Impaired spatial reference memory in aromatase-deficient (ArKO) mice. Neuroreport 2003; 14:1979-82. [PMID: 14561933 DOI: 10.1097/00001756-200310270-00020] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous studies indicate an important role for estrogen in memory and learning. Aromatase-knockout (ArKO) mice are unable to produce estrogen because they lack a functional Cyp 19 gene that encodes for aromatase, the enzyme that converts testosterone into estrogen. Using a Y-maze test for short-term spatial reference memory, we found that both male and female ArKO mice performed significantly worse than wildtype controls. Gonadectomy reduced Y-maze responses in male and female wildtype controls, but had no effect in ArKO mice. After gonadectomy, there was no significant difference between wildtype and ArKO mice. For the first time using ArKO mice, our findings confirm the importance of estrogen in memory in both males and females.
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Affiliation(s)
- Sally Martin
- Behavioural Neuroscience Laboratory, Mental Health Research Institute, 155 Oak Street, Parkville, Victoria 3052, Australia
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Sutherland MK, Brady H, Gayo-Fung LM, Leisten J, Lipps SG, McKie JA, O'Leary E, Patnaik N, Anderson DW, Bhagwat SS, Stein B. Effects of SP500263, a novel selective estrogen receptor modulator, on bone, uterus, and serum cholesterol in the ovariectomized rat. Calcif Tissue Int 2003; 72:710-6. [PMID: 14563000 DOI: 10.1007/s00223-002-1029-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We describe here the activity of a novel selective estrogen receptor modulator, SP500263. When given to adult ovariectomized (OVX) rats for 28 days at doses of 0.3, 1, or 3 mg/kg/day, we found that SP500263 partially protected against OVX-induced loss of bone mineral content in the distal ends of femurs and in the whole bone. SP500263 also antagonized the OVX-induced increase in body weight. However, unlike 17beta-estradiol, SP500263 at efficacious doses did not prevent the OVX-induced loss in uterine wet weight. A small but significant effect on uterine wet weight was noted with raloxifene dosed at 1 mg/kg. As expected, SP500263 but not raloxifene acted as an estrogen antagonist on the uterus in adult rats when administered for 7 days at 30 mg/kg/day. Finally, SP500263 had no statistically significant effects on total serum cholesterol and serum triglycerides in OVX rats treated for 28 days. Raloxifene had no significant effects on body weight, bone mineral content, and serum cholesterol or triglycerides in the OVX-rat model. In summary, SP500263 is a new orally active SERM that acts in rats as an estrogen agonist on bone without causing uterine stimulatory effects.
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Abstract
OBJECTIVE To determine use of botanical dietary supplements (BDS) in women between the ages of 40 and 60 years at the University of Illinois at Chicago (UIC) clinics, including information about commonly used BDS, the reason for use, information resources used, and the overall perception of safety and efficacy of BDS. DESIGN Five hundred female outpatients at UIC clinics were interviewed by healthcare practitioners using a botanical/drug history questionnaire. Respondents were 46.8% African American, 39.6% Caucasian, 11.7% Hispanic, and 1.5% Asian, with a mean age of 50.34 years. RESULTS BDS were used by 79% of respondents ( = 395), of which 36.5% used BDS daily. Of the positive respondents, 51.7% used one or two BDS, whereas 48.4% used three or more. Commonly used botanicals included soy (42%), green tea (34.68%), chamomile (20.76%), gingko (20.51%), ginseng (17.97%), Echinacea (15.44%), and St. John's wort (7.34%). Black cohosh, garlic, red clover, kava, valerian, evening primrose, and ephedra were used by less than 15% of respondents. Efficacy ratings were high for BDS, and 68% claimed to have no side effects. Only 3% of respondents obtained BDS information from healthcare professionals, and 70% of respondents were not informing their physician of BDS use. CONCLUSIONS A high percentage of women at UIC clinics were using multiple BDS. The respondents believed that these products were both safe and effective for the treatment of common ailments. Concomitant BDS use with prescription and over-the-counter medications was commonplace, often without a physician's knowledge. Consumer education about the possible benefits and risks associated with BDS use is urgently needed.
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Affiliation(s)
- Gail B Mahady
- University of Illinois at Chicago/National Institutes of Health Center for Botanical Dietary Supplements Research, Department of Pharmacy Practice, Center for Excellence in Women's Health, Chicago, Illinois, USA.
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Mahady GB, Fabricant D, Chadwick LR, Dietz B. Black cohosh: an alternative therapy for menopause? NUTRITION IN CLINICAL CARE : AN OFFICIAL PUBLICATION OF TUFTS UNIVERSITY 2002; 5:283-9. [PMID: 12557811 DOI: 10.1046/j.1523-5408.2002.05603.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Due to the long-term health risks now associated with hormone replacement therapy, many menopausal women are actively seeking alternative treatments. One such alternative is black cohosh (Actaea racemosa, syn. Cimicifuga racemosa), which has been used in the United States for the treatment of gynecologic complaints for more than 100 years. Review of the published clinical data suggests that black cohosh may be useful for the treatment of menopausal symptoms, such as hot flashes, profuse sweating, insomnia, and anxiety. Results from the most recently published trial, however, indicate that black cohosh is not effective for the treatment of menopausal symptoms in breast cancer survivors being treated with tamoxifen. Because the overall quality of the published clinical trials is low, two new randomized, double-blind, placebo-controlled clinical trials are currently underway in the United States. To date, only one standardized black cohosh extract has been tested clinically; the current recommended dose is 40-80 mg per day. At least 4-12 weeks of treatment may be required before any therapeutic benefits may be apparent. Adverse reactions such as nausea, vomiting, headaches, dizziness, mastalgia, and weight gain have been observed in clinical trials. No drug interactions are reported in the medical literature. The estrogenic effects of black cohosh are controversial, and the more recent data indicate that black cohosh extracts may have an anti-estrogenic activity. Owing to potential effects on sex hormones, however, black cohosh should not be administered to children or during pregnancy and lactation.
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Affiliation(s)
- Gail B Mahady
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences, University of Illinois, Chicago, Illinois, USA
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