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Abstract
Estrogen has pleiotropic effects on the cardiovascular system. The mechanisms by which estrogen confers these pleiotropic effects are undergoing active investigation. Until a decade ago, all estrogen signaling was thought to occur by estrogen binding to nuclear estrogen receptors (estrogen receptor-α and estrogen receptor-β), which bind to DNA and function as ligand-activated transcription factors. Estrogen binding to the receptor alters gene expression, thereby altering cell function. Estrogen also binds to nuclear estrogen receptors that are tethered to the plasma membrane, resulting in acute activation of signaling kinases such as PI3K. An orphan G-protein-coupled receptor, G-protein-coupled receptor 30, can also bind estrogen and activate acute signaling pathways. Thus, estrogen can alter cell function by binding to different estrogen receptors. This article reviews the different estrogen receptors and their signaling mechanisms, discusses mechanisms that regulate estrogen receptor levels and locations, and considers the cardiovascular effects of estrogen signaling.
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Affiliation(s)
- Elizabeth Murphy
- Cardiac Physiology Section, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Van Bergen NJ, Chakrabarti R, O’Neill EC, Crowston JG, Trounce IA. Mitochondrial disorders and the eye. Eye Brain 2011; 3:29-47. [PMID: 28539774 PMCID: PMC5436186 DOI: 10.2147/eb.s16192] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The clinical significance of disturbed mitochondrial function in the eye has emerged since mitochondrial DNA (mtDNA) mutation was described in Leber's hereditary optic neuropathy. The spectrum of mitochondrial dysfunction has become apparent through increased understanding of the contribution of nuclear and somatic mtDNA mutations to mitochondrial dynamics and function. Common ophthalmic manifestations of mitochondrial dysfunction include optic atrophy, pigmentary retinopathy, and ophthalmoplegia. The majority of patients with ocular manifestations of mitochondrial disease also have variable central and peripheral nervous system involvement. Mitochondrial dysfunction has recently been associated with age-related retinal disease including macular degeneration and glaucoma. Therefore, therapeutic targets directed at promoting mitochondrial biogenesis and function offer a potential to both preserve retinal function and attenuate neurodegenerative processes.
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Affiliation(s)
- Nicole J Van Bergen
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Rahul Chakrabarti
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Evelyn C O’Neill
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Ian A Trounce
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, Australia
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53
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Arechederra RL, Waheed A, Sly WS, Minteer SD. Electrically wired mitochondrial electrodes for measuring mitochondrial function for drug screening. Analyst 2011; 136:3747-52. [DOI: 10.1039/c1an15370f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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54
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Jian B, Yang S, Chen D, Zou L, Chatham JC, Chaudry I, Raju R. Aging influences cardiac mitochondrial gene expression and cardiovascular function following hemorrhage injury. Mol Med 2010; 17:542-9. [PMID: 21193900 DOI: 10.2119/molmed.2010.00195] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 12/21/2010] [Indexed: 01/07/2023] Open
Abstract
Cardiac dysfunction and mortality associated with trauma and sepsis increase with age. Mitochondria play a critical role in the energy demand of cardiac muscles, and thereby on the function of the heart. Specific molecular pathways responsible for mitochondrial functional alterations after injury in relation to aging are largely unknown. To further investigate this, 6- and 22-month-old rats were subjected to trauma-hemorrhage (T-H) or sham operation and euthanized following resuscitation. Left ventricular tissue was profiled using our custom rodent mitochondrial gene chip (RoMitochip). Our experiments demonstrated a declined left ventricular performance and decreased alteration in mitochondrial gene expression with age following T-H and we have identified c-Myc, a pleotropic transcription factor, to be the most upregulated gene in 6- and 22-month-old rats after T-H. Following T-H, while 142 probe sets were altered significantly (39 up and 103 down) in 6-month-old rats, only 66 were altered (30 up and 36 down) in 22-month-old rats; 36 probe sets (11 up and 25 down) showed the same trend in both groups. The expression of c-Myc and cardiac death promoting gene Bnip3 were increased, and Pgc1-α and Ppar-α a decreased following T-H. Eleven tRNA transcripts on mtDNA were upregulated following T-H in the aged animals, compared with the sham group. Our observations suggest a c-myc-regulated mitochondrial dysfunction following T-H injury and marked decrease in age-dependent changes in the transcriptional profile of mitochondrial genes following T-H, possibly indicating cellular senescence. To our knowledge, this is the first report on mitochondrial gene expression profile following T-H in relation to aging.
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Affiliation(s)
- Bixi Jian
- Center for Surgical Research, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
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55
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Abstract
The hypoxic conditions induced by reduced blood flow decreases oxygen availability in target tissues. Cellular hypoxia leads to mitochondrial dysfunction, decreased energy production, and increased production of reactive oxygen species. To determine the alteration in expression of mitochondrial genes after hypoxia in cardiomyocytes, we developed a rodent mitochondrial gene chip (RoMitoChip). The chip had 1088 probe sets including 46 probe sets representing 37 mouse mitochondrial DNA transcripts and the remaining probe sets representing mouse nuclear genes contributing to the mitochondrial structure and function. Mouse cardiomyocytes isolated from neonatal C57BL/6 mice that were subjected to hypoxia (1% oxygen) for different time intervals demonstrated a dichotomy in the expression profile of tRNA and mRNA transcripts. We report a total of 483 signature genes that were altered by hypoxia in the cardiac myocytes and related to mitochondrial structure and function. This includes 23 transcripts on mitochondrial DNA. Pathway analysis demonstrated predominant changes in the expression of genes involved in oxidative phosphorylation, glucose and fatty acid metabolism, and apoptosis. The most upregulated genes after 24 h of hypoxia included hypoxia-inducible factor 1, alpha subunit, inducible genes Bnip3, Pdk1, and Aldoc. Whereas Bnip3 is important in the cardiomyocyte death pathway, Pdk1 enzyme is critical in conserving mitochondrial function by diverting metabolic intermediates to glycolysis. This study identifies the participation of two important pathways, cell death and glycolytic, and two key proteins, Bnip3 and Pdk1, playing critical roles in these pathways in cardiomyocytes after severe hypoxia.
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Single Photon Emission Computed Tomography Demonstrated Efficacy of 17β-Estradiol Therapy in Male Rats After Trauma-Hemorrhage and Extended Hypotension. ACTA ACUST UNITED AC 2010; 69:1266-73. [DOI: 10.1097/ta.0b013e3181dbb0b2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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57
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Alvarez-Delgado C, Mendoza-Rodríguez CA, Picazo O, Cerbón M. Different expression of alpha and beta mitochondrial estrogen receptors in the aging rat brain: interaction with respiratory complex V. Exp Gerontol 2010; 45:580-5. [PMID: 20096765 DOI: 10.1016/j.exger.2010.01.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 01/11/2010] [Accepted: 01/14/2010] [Indexed: 01/11/2023]
Abstract
Recent evidence suggests that hormonal effects on mitochondria could be mediated by mitochondrial estrogen receptors (mtERs). These receptors are new candidates for the beneficial estrogenic effects on mitochondria in different physiological conditions. The aim of this investigation was to study mtER expression during brain aging. We analyzed mtERalpha and mtERbeta expression in cortical, hippocampal and hypothalamic mitochondria of young adult (3months) and aged (18 months) female Wistar rats by Western blot. In addition, we explored the interaction of mtERbeta with respiratory complex V by using coimmunoprecipitation assays. The results show that mtERalpha and mtERbeta are present in young and aged brain mitochondria. We also demonstrate that mtERs are expressed as variants and have a brain region specific distribution. The predominant mtER variants detected were of 61 and 55KDa for mtERalpha and of 63 and 52KDa for mtERbeta. However, we did not observe differences in the mtERalpha or beta content between the two age groups studied. Additionally, we show that mtERbeta interacts with complex V. The overall results demonstrate that there is a differential expression of mtERalpha and mtERbeta variants in different brain areas, indicating that they may participate in different functions in the brain during aging.
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Affiliation(s)
- Carolina Alvarez-Delgado
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México, México D.F., Mexico
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58
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DonCarlos LL, Azcoitia I, Garcia-Segura LM. Neuroprotective actions of selective estrogen receptor modulators. Psychoneuroendocrinology 2009; 34 Suppl 1:S113-22. [PMID: 19447561 PMCID: PMC2794899 DOI: 10.1016/j.psyneuen.2009.04.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 04/20/2009] [Accepted: 04/20/2009] [Indexed: 12/13/2022]
Abstract
Decreasing levels of sex hormones with aging may have a negative impact on brain function, since this decrease is associated with the progression of neurodegenerative disorders, increased depressive symptoms and other psychological disturbances. Extensive evidence from animal studies indicates that sex steroids, in particular estradiol, are neuroprotective. However, the potential benefits of estradiol therapy for the brain are counterbalanced by negative, life-threatening risks in the periphery. A potential therapeutic alternative to promote neuroprotection is the use of selective estrogen receptor modulators (SERMs), which may be designed to act with tissue selectivity as estrogen receptor agonists in the brain and not in other organs. Currently available SERMs act not only with tissue selectivity, but also with cellular selectivity within the brain and differentially modulate the activation of microglia, astroglia and neurons. Finally, SERMs may promote the interaction of estrogen receptors with the neuroprotective signaling of growth factors, such as the phosphatidylinositol 3-kinase/glycogen synthase kinase 3 pathway.
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Affiliation(s)
- Lydia L. DonCarlos
- Department of Cell Biology, Neurobiology and Anatomy, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, Illinois 60153, USA. Tel: +1-7082164975; Fax: +1-7082163913; e-mail:
| | - Iñigo Azcoitia
- Departamento de Biología Celular, Facultad de Biología, Universidad Complutense, E-28040 Madrid, Spain. Tel: +34-913944861, Fax: +34-913944981 e-mail:
| | - Luis M. Garcia-Segura
- Instituto Cajal, CSIC, E-28002 Madrid, Spain. Tel:+34-915854729; Fax: +34-915854754; e-mail:
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59
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Simpkins JW, Yi KD, Yang SH, Dykens JA. Mitochondrial mechanisms of estrogen neuroprotection. Biochim Biophys Acta Gen Subj 2009; 1800:1113-20. [PMID: 19931595 DOI: 10.1016/j.bbagen.2009.11.013] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 01/11/2023]
Abstract
Mitochondria have become a primary focus in our search not only for the mechanism(s) of neuronal death but also for neuroprotective drugs and therapies that can delay or prevent Alzheimer's disease and other chronic neurodegenerative conditions. This is because mitochrondria play a central role in regulating viability and death of neurons, and mitochondrial dysfunction has been shown to contribute to neuronal death seen in neurodegenerative diseases. In this article, we review the evidence for the role of mitochondria in cell death and neurodegeneration and provide evidence that estrogens have multiple effects on mitochondria that enhance or preserve mitochondrial function during pathologic circumstances such as excitotoxicity, oxidative stress, and others. As such, estrogens and novel non-hormonal analogs have come to figure prominently in our efforts to protect neurons against both acute brain injury and chronic neurodegeneration.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology & Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, TX, USA.
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60
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Vornehm ND, Wang M, Abarbanell A, Herrmann J, Weil B, Tan J, Wang Y, Kelly M, Meldrum DR. Acute postischemic treatment with estrogen receptor-alpha agonist or estrogen receptor-beta agonist improves myocardial recovery. Surgery 2009; 146:145-54. [PMID: 19628068 DOI: 10.1016/j.surg.2009.04.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 04/17/2009] [Indexed: 11/24/2022]
Abstract
BACKGROUND After ischemia/reperfusion (I/R) injury, female hearts demonstrate improved functional recovery compared with male, which suggests a protective role for estrogen. Acute postischemic treatment with 17-beta-estradiol (E2) attenuates myocardial dysfunction. However, it is unknown by which estrogen receptor (ER) E2 mediates this acute cardioprotection during I/R. Therefore, we hypothesize that postischemic infusion of the selective ER-alpha agonist (4,4',4''-[4-propyl-(1H)-pyrazole-1,3,5-triyl]tris-phenol [PPT]) or the selective ER-beta agonist (2,3-bis(4-hydroxyphenyl)-propionitrile [DPN]) will improve myocardial function after I/R injury. METHODS Isolated, perfused hearts (Langendorff) from adult male rats were subjected to 25 minutes of ischemia followed by 40 minutes of reperfusion. Hearts (n = 4-6 per group) were randomly infused with either perfusate, PPT or DPN at 1, 10, or 100 nmol/L throughout reperfusion. After I/R, heart tissue was analyzed for tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, vascular endothelial growth factor (VEGF), and lactate dehydrogenase (LDH). RESULTS Postischemic treatment with 10 nmol/L of PPT significantly improved myocardial function. Additionally, 10 or 100 nmol/L of DPN significantly increased myocardial functional recovery after I/R injury, with maximum benefit at the 10 nmol/L dose. A trend toward lower levels of LDH was noted in DPN- and PPT-treated groups after I/R injury. Neither PPT nor DPN affected myocardial production of TNF-alpha or IL-1beta. However, higher levels of myocardial VEGF were noted in the PPT-treated group compared with controls. CONCLUSION Both ER-alpha and ER-beta are involved in mediating E2-induced rapid cardioprotection after I/R injury. Advancing our understanding of both ER subtypes may be useful for the development of novel strategies that may benefit both males and females in response to myocardial ischemia.
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Affiliation(s)
- Nicholas D Vornehm
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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61
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Chen J, Russo J. Mitochondrial oestrogen receptors and their potential implications in oestrogen carcinogenesis in human breast cancer. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13590840801972074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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62
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Role of protein phosphatases and mitochondria in the neuroprotective effects of estrogens. Front Neuroendocrinol 2009; 30:93-105. [PMID: 19410596 PMCID: PMC2835549 DOI: 10.1016/j.yfrne.2009.04.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/20/2009] [Accepted: 04/21/2009] [Indexed: 12/15/2022]
Abstract
In the present treatise, we provide evidence that the neuroprotective and mito-protective effects of estrogens are inexorably linked and involve the ability of estrogens to maintain mitochondrial function during neurotoxic stress. This is achieved by the induction of nuclear and mitochondrial gene expression, the maintenance of protein phosphatases levels in a manner that likely involves modulation of the phosphorylation state of signaling kinases and mitochondrial pro- and anti-apoptotic proteins, and the potent redox/antioxidant activity of estrogens. These estrogen actions are mediated through a combination of estrogens receptor (ER)-mediated effects on nuclear and mitochondrial transcription of protein vital to mitochondrial function, ER-mediated, non-genomic signaling and non-ER-mediated effects of estrogens on signaling and oxidative stress. Collectively, these multifaceted, coordinated action of estrogens leads to their potency in protecting neurons from a wide variety of acute insults as well as chronic neurodegenerative processes.
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63
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Chen JQ, Cammarata PR, Baines CP, Yager JD. Regulation of mitochondrial respiratory chain biogenesis by estrogens/estrogen receptors and physiological, pathological and pharmacological implications. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1540-70. [PMID: 19559056 DOI: 10.1016/j.bbamcr.2009.06.001] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 12/21/2022]
Abstract
There has been increasing evidence pointing to the mitochondrial respiratory chain (MRC) as a novel and important target for the actions of 17beta-estradiol (E(2)) and estrogen receptors (ER) in a number of cell types and tissues that have high demands for mitochondrial energy metabolism. This novel E(2)-mediated mitochondrial pathway involves the cooperation of both nuclear and mitochondrial ERalpha and ERbeta and their co-activators on the coordinate regulation of both nuclear DNA- and mitochondrial DNA-encoded genes for MRC proteins. In this paper, we have: 1) comprehensively reviewed studies that reveal a novel role of estrogens and ERs in the regulation of MRC biogenesis; 2) discussed their physiological, pathological and pharmacological implications in the control of cell proliferation and apoptosis in relation to estrogen-mediated carcinogenesis, anti-cancer drug resistance in human breast cancer cells, neuroprotection for Alzheimer's disease and Parkinson's disease in brain, cardiovascular protection in human heart and their beneficial effects in lens physiology related to cataract in the eye; and 3) pointed out new research directions to address the key questions in this important and newly emerging area. We also suggest a novel conceptual approach that will contribute to innovative regimens for the prevention or treatment of a wide variety of medical complications based on E(2)/ER-mediated MRC biogenesis pathway.
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Affiliation(s)
- Jin-Qiang Chen
- Breast Cancer Research Laboratory, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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64
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Zhang S, Ding JH, Zhou F, Wang ZY, Zhou XQ, Hu G. Iptakalim ameliorates MPP+-induced astrocyte mitochondrial dysfunction by increasing mitochondrial complex activity besides opening mitoK(ATP) channels. J Neurosci Res 2009; 87:1230-9. [PMID: 19006086 DOI: 10.1002/jnr.21931] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In addition to the established role of the mitochondrion in energy metabolism, regulation of cell death has been regarded as a major function of this organelle. Our previous studies have demonstrated that iptakalim (IPT), a novel ATP-sensitive potassium channel (K(ATP) channel) opener, protects against 1-methyl-4-phenyl-pyridinium ion (MPP+)-induced astrocyte apoptosis via mitochondria and mitogen-activated protein kinase signal pathways. The present study aimed to investigate whether IPT can protect astrocyte mitochondria against MPP+-induced mitochondrial dysfunction. We showed that treatment with IPT could ameliorate the inhibitory effect of MPP+ on mitochondrial respiration and ATP production by using mitochondrial complex I-supported substrates. IPT could also inhibit the increased production of mitochondrial reactive oxygen species (ROS) and the release of cytochrome c from mitochondria induced by MPP+. However, mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel blocker 5-hydroxydecanoate (5-HD) could partly abolish all of the above effects of IPT. Because mitochondrial complex dysfunction impairs mitochondrial respiration and ATP production, a further experiment was undertaken to study the effects of IPT on the activity of mitochondrial complex (COX) I and COX IV. It was found that IPT inhibited the decrease in mitochondrial COX I and COX IV activity induced by MPP+, but 5-HD failed to abolish these effects. Taken together, these findings suggest that IPT may protect astrocyte mitochondrial function by regulating complex activity in addition to opening mitoK(ATP) channels.
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Affiliation(s)
- Shu Zhang
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, Peoples Republic of China
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65
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Ma Y, Cheng WT, Wu S, Wong TM. Oestrogen confers cardioprotection by suppressing Ca2+/calmodulin-dependent protein kinase II. Br J Pharmacol 2009; 157:705-15. [PMID: 19422373 DOI: 10.1111/j.1476-5381.2009.00212.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Oestrogen confers cardioprotection by down-regulating the beta(1)-adrenoceptor and suppressing the expression and activity of protein kinase A. We hypothesized that oestrogen may also protect the heart by suppressing Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), another signalling messenger activated by the beta(1)-adrenoceptor, that enhances apoptosis. EXPERIMENTAL APPROACH We first determined the expression of CaMKII in the heart from sham and ovariectomized rats with and without oestrogen replacement. We then determined the effects of CaMKII inhibition (KN93, 2.5 micromolxL(-1)) in the presence or absence of 10(-7) molxL(-1) isoprenaline, a non-selective beta-adrenoceptor agonist. We also determined the percentage apoptosis in myocytes from rats in each group with or without beta-adrenoceptor stimulation. KEY RESULTS Both CaMKIIdelta and phosphorylated CaMKII were up-regulated in the hearts from ovariectomized rats, and they were restored to normal by oestrogen replacement. The infarct size and lactate dehydrogenase release were significantly greater after ovariectomy. Similarly, cardiac contractility, the amplitude of the electrically induced intracellular Ca(2+) transient and the number of apoptotic cells were also greater in ovariectomized rats upon ischaemia/reperfusion in the presence or absence of isoprenaline. Most importantly, the responses to ischaemic insult in ovariectomized rats were reversed not only by oestrogen replacement, but by blockade of CaMKII with KN93. CONCLUSIONS AND IMPLICATIONS Oestrogen confers cardioprotection at least partly by suppressing CaMKIIdelta. This effect of oestrogen on CaMKII is independent of the beta-adrenoceptor and occurs in addition to down-regulation of the receptor.
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Affiliation(s)
- Y Ma
- Department of Physiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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66
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Systematic analysis of the salutary effect of estrogen on cardiac performance after trauma-hemorrhage. Shock 2009; 30:585-9. [PMID: 18391854 DOI: 10.1097/shk.0b013e31816f1a45] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although 17beta-estradiol (estrogen) and estrogen receptor (ER) agonist administration after trauma-hemorrhage improves cardiac function, it remains unknown what the optimal estrogen or ER agonist dosage is to elicit this beneficial effect. To study this, the dose-dependent effects of estrogen, propylpyrazole triol (ER-alpha agonist), and diarylpropionitrile (DPN; ER-beta agonist) on heart performance (+dP/dt) were determined in sham rats and in experimental animals at the time of maximal bleedout (MBO) or at 2 h after trauma-hemorrhage. The results showed that estrogen and DPN induced dose-dependent increases in the maximal rate of left ventricular pressure increase (+dP/dt) in all groups, whereas propylpyrazole triol was ineffective at all doses. The maximal dose and the 50% effective dose of DPN were approximately 100-fold lower than those of estrogen. The half-life of estrogen in plasma was approximately 25 min in sham and MBO groups. A positive correlation between the estrogen-induced increase in +dP/dt and survival in MBO rats were observed. These results collectively suggest that the salutary effects of estrogen on cardiac performance are dose-dependent and mediated via ER-beta.
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Abstract
Sex is increasingly recognized as a major factor in the outcome of patients who have trauma and sepsis. Moreover, sex steroids influence chemokine/adhesion molecule expression and neutrophil accumulation. Heat shock proteins, heat shock factor 1, and peroxisome proliferator-activated receptor [gamma] coactivator 1 are regulated by the estrogen receptors and consequently contribute to organ protection after trauma-hemorrhage. Additionally, sex steroids regulate inflammatory cytokines, leading to increased morbidity and mortality. This article deals with trauma-hemorrhage and examines the following: 1) the evidence for sex differences; 2) the mechanisms by which sex hormones affect organ protection; 3) the tissue-specific effect of sex hormone receptors; and 4) the effect of genomic and nongenomic (i.e. membrane-initiated steroid signaling) pathways of sex hormones after trauma. The available information indicates that sex steroids modulate cardiovascular responses after trauma. Thus, alteration or modulation of the prevailing hormone milieu at the time of injury seems to be a novel therapeutic option for improving outcome after injury
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68
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Hsieh YC, Athar M, Chaudry IH. When apoptosis meets autophagy: deciding cell fate after trauma and sepsis. Trends Mol Med 2009; 15:129-38. [PMID: 19231289 DOI: 10.1016/j.molmed.2009.01.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/09/2009] [Accepted: 01/09/2009] [Indexed: 02/08/2023]
Abstract
Apoptotic cell death is considered to be an underlying mechanism in immunosuppression and multiple organ dysfunction after trauma-hemorrhage and sepsis. Although studied intensively over the last decade, the role of other cell death mechanisms under similar pathophysiological conditions has remained elusive. Recently, autophagy has emerged as an important mediator of programmed cell death pathways. Here, we review recent advances in our understanding of apoptosis and autophagy and the crosstalk between these processes. We explore the coexistence of these two processes and the effects of autophagy on apoptosis after trauma-hemorrhage and sepsis. The inter-relationship between autophagy and apoptosis might unveil novel therapeutic approaches for the detection and treatment of trauma-hemorrhage and sepsis.
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Affiliation(s)
- Ya-Ching Hsieh
- Department of Medical Research, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan, ROC
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69
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Abstract
Estrogens have cell-specific effects on a variety of physiological endpoints including regulation of mitochondrial biogenesis and activity. Estrogens regulate gene transcription by the classical genomic mechanism of binding to estrogen receptors alpha and beta (ERalpha and ERbeta) as well as the more recently described nongenomic pathways involving plasma membrane-associated ERs that activate intracellular protein kinase-mediated phosphorylation signaling cascades. Here I will review the rapid and longer-term effects of estrogen on mitochondrial function. The identification of ERalpha and ERbeta within mitochondria of various cells and tissues is discussed with a model of estrogen regulation of the transcription of nuclear respiratory factor-1 (NRF-1, NRF1). NRF-1 subsequently promotes transcription of mitochondrial transcription factor Tfam (mtDNA maintenance factor, also called mtTFA) and then Tfam targets mtDNA-encoded genes. The nuclear effects of estrogens on gene expression directly controlling mitochondrial biogenesis, oxygen consumption, mtDNA transcription, and apoptosis are reviewed. Overall, we are just beginning to evaluate the many direct and indirect effects of estrogens on mitochondrial activities.
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Affiliation(s)
- Carolyn M Klinge
- Department of Biochemistry & Molecular Biology, Center for Genetics and Molecular Medicine, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA.
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70
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Psarra AMG, Sekeris CE. Glucocorticoid receptors and other nuclear transcription factors in mitochondria and possible functions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:431-6. [PMID: 19100710 DOI: 10.1016/j.bbabio.2008.11.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 11/17/2008] [Accepted: 11/24/2008] [Indexed: 11/16/2022]
Abstract
The central role of mitochondria in basic physiological processes has rendered this organelle a receiver and integrator of multiple regulatory signals. Steroid and thyroid hormones are major modulators of mitochondrial functions and the question arises as to how these molecules act at the molecular level. The detection in mitochondria of steroid and thyroid hormone receptors suggested their direct action on mitochondrial functions within the context of the organelle. The interaction of the receptors with regulatory elements of the mitochondrial genome and the activation of gene transcription underlies the hormonal stimulation of energy yield. Glucocorticoid activation of hepatocyte RNA synthesis is one of the experimental models exploited in this respect. Furthermore, the interaction of the receptors with apoptotic/antiapoptotic factors is possibly associated with the survival-death effects of the hormones. In addition to the steroid/thyroid hormone receptors, several other receptors belonging to the superfamily of nuclear receptors, as well as transcription factors with well defined nuclear actions, have been found in mitochondria. How these molecules act and interact and how they can affect the broad spectrum of mitochondrial functions is an emerging exciting field.
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Affiliation(s)
- Anna-Maria G Psarra
- Biomedical Research Foundation, Academy of Athens, Center for Basic Research, 4 Soranou Efesiou, 11527, Athens, Greece
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Jian B, Hsieh CH, Chen J, Choudhry M, Bland K, Chaudry I, Raju R. Activation of endoplasmic reticulum stress response following trauma-hemorrhage. Biochim Biophys Acta Mol Basis Dis 2008; 1782:621-6. [PMID: 18801427 DOI: 10.1016/j.bbadis.2008.08.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 08/15/2008] [Accepted: 08/19/2008] [Indexed: 11/18/2022]
Abstract
Hemorrhagic trauma leads to organ dysfunction, sepsis and death. There is abnormal production of proinflammatory cytokines by Kupffer cells, tissue hypoxia and liver injury following trauma-hemorrhage. The physiological conditions consequent to trauma-hemorrhage are consistent with factors necessary to initiate endoplasmic reticulum (ER) stress and unfolded protein response. However, the contribution of ER stress to apoptosis and liver injury after trauma-hemorrhage is not known. In the present study ER stress was investigated in mice that underwent trauma-hemorrhage or sham operation. Expressions of endoplasmic reticulum stress proteins Bip, ATF6, PERK, IRE1alpha, and PDI were significantly elevated in the liver after trauma-hemorrhage compared to the controls. The ER stress associated proapoptotic transcription factor CHOP protein expression was also significantly elevated in trauma-hemorrhage group. Consistent with this, enhanced DNA fragmentation was observed, confirming apoptosis, in the liver following trauma-hemorrhage. These results demonstrate the initiation of ER stress and its role in apoptosis and liver injury, subsequent to hemorrhagic trauma.
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Affiliation(s)
- Bixi Jian
- Center for Surgical Research, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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73
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Simpkins JW, Yang SH, Sarkar SN, Pearce V. Estrogen actions on mitochondria--physiological and pathological implications. Mol Cell Endocrinol 2008; 290:51-9. [PMID: 18571833 PMCID: PMC2737506 DOI: 10.1016/j.mce.2008.04.013] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 04/08/2008] [Accepted: 04/10/2008] [Indexed: 02/07/2023]
Abstract
Estrogens are potent neuroprotective hormones and mitochondria are the site of cellular life-death decisions. As such, it is not surprising that we and others have shown that estrogens have remarkable effects on mitochondrial function. Herein we provide evidence for a primary effect of estrogens on mitochondrial function, achieved in part by the import of estrogen receptor beta (ERbeta) into the mitochondria where it mediates a number of estrogen actions on this vital organelle. ERbeta is imported into the mitochondria, through tethering to cytosolic chaperone protein and/or through direct interaction with mitochondrial import proteins. In the mitochondria, ERbeta can affect transcription of critical mitochondrial genes through the interaction with estrogen response elements (ERE) or through protein-protein interactions with mitochondrially imported transcription factors. The potent effects of estrogens on mitochondrial function, particularly during mitochondrial stress, argues for a role of estrogens in the treatment of mitochondrial defects in chronic neurodegenerative diseases like Alzheimer's disease (AD) and Parkinson's disease (PD) and more acute conditions of mitochondrial compromise, like cerebral ischemia and traumatic brain injury.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology & Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA.
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74
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Estrogen Ameliorates Trauma-hemorrhage–induced Lung Injury via Endothelial Nitric Oxide Synthase-dependent Activation of Protein Kinase G. Ann Surg 2008; 248:294-302. [DOI: 10.1097/sla.0b013e318180a3db] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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75
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Araújo GW, Beyer C, Arnold S. Oestrogen influences on mitochondrial gene expression and respiratory chain activity in cortical and mesencephalic astrocytes. J Neuroendocrinol 2008; 20:930-41. [PMID: 18445124 DOI: 10.1111/j.1365-2826.2008.01747.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The regulation of mitochondrial energy metabolism plays an essential role in the central nervous system (CNS). Abnormalities of the mitochondrial respiratory chain often accompany neurodegenerative diseases. This makes mitochondria a perfect target for strategies of cellular protection against toxic compounds and pathological conditions. Steroid hormones, such as oestrogen, are well-known to fulfil a protective role in the brain during ischaemic and degenerative processes. Because astrocytes function as the major energy supplier in the CNS, we have analysed oestrogen effects on the mitochondrial respiratory chain of this cell type. In our studies, we applied semi- and quantitative polymerase chain reaction analysis of gene expression and polarographic measurements of the respiratory chain activity of mitochondria. We observed that structural and functional properties were regulated dependent on the oestrogen exposure time and the brain region, but independent of the nuclear oestrogen receptors. We could demonstrate that long-term oestrogen exposure increases the subunit gene expression of respiratory chain complexes and the mitochondrial DNA content, thereby indicating an up-regulation of the amount of mitochondria per cell together with an increase of mitochondrial energy production. This could represent an important indirect mechanism by which long-term oestrogen exposure protects neurones from cell death under neurotoxic conditions. On the other hand, we observed short-term effects of oestrogen on the activity of mitochondrial, proton-pumping respiratory chain complexes. In astrocytes from the cortex, respiratory chain activity was decreased, whereas it was increased in astrocytes from the mesencephalon. An increased production of reactive oxygen species would be the consequence of an increased respiratory chain activity in mesencephalic astrocytes. This could explain the different efficiencies of oestrogen-mediated short-term protection in distinct brain regions, but also indicates the limitations for a therapeutic short-term application of oestrogen.
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Affiliation(s)
- G W Araújo
- Institute for Neuroanatomy, Faculty of Medicine, RWTH, Aachen, Germany
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76
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Chen JQ, Brown TR, Yager JD. Mechanisms of hormone carcinogenesis: evolution of views, role of mitochondria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008. [PMID: 18637481 DOI: 10.1007/978-0-387-78818-0_1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
CumuIative and excessive exposure to estrogens is associated with increased breast cancer risk. The traditional mechanism explaining this association is that estrogens affect the rate of cell division and apoptosis and thus manifest their effect on the risk of breast cancer by affecting the growth of breast epithelial tissues. Highly proliferative cells are susceptible to genetic errors during DNA replication. The action of estrogen metabolites offers a complementary genotoxic pathway mediated by the generation of reactive estrogen quinone metabolites that can form adducts with DNA and generate reactive oxygen species through redox cycling. In this chapter, we discussed a novel mitochondrial pathway mediated by estrogens and their cognate estrogen receptors (ERs) and its potential implications in estrogen-dependent carcinogenesis. Several lines of evidence are presented to show: (1) mitochondrial localization of ERs in human breast cancer cells and other cell types; (2) a functional role for the mitochondrial ERs in regulation of the mitochondrial respiratory chain (MRC) proteins and (3) potential implications of the mitochondrial ER-mediated pathway in stimulation of cell proliferation, inhibition of apoptosis and oxidative damage to mitochondrial DNA. The possible involvement of estrogens and ERs in deregulation of mitochondrial bioenergetics, an important hallmark of cancer cells, is also described. An evolutionary view is presented to suggest that persistent stimulation by estrogens through ER signaling pathways of MRC proteins and energy metabolic pathways leads to the alterations in mitochondrial bioenergetics and contributes to the development of estrogen-related cancers.
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Affiliation(s)
- Jin-Qiang Chen
- Division of Pulmonary and Critical Care, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908-0546, USA.
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77
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Yin Y, Huang WW, Lin C, Chen H, MacKenzie A, Ma L. Estrogen suppresses uterine epithelial apoptosis by inducing birc1 expression. Mol Endocrinol 2008; 22:113-25. [PMID: 17901126 PMCID: PMC2171041 DOI: 10.1210/me.2007-0295] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 09/18/2007] [Indexed: 12/30/2022] Open
Abstract
The decision whether or not a cell undergoes apoptosis is determined by the opposing forces of pro- and antiapoptotic effectors. Here we demonstrate genetically that estrogen can tip this balance toward cell survival in uterine epithelial cells by inducing the expression of baculoviral inhibitors of apoptosis repeat-containing 1 (Birc1), a family of antiapoptotic proteins. In neonatal mice, both 17beta-estradiol and the potent synthetic estrogen diethylstilbestrol strongly suppress uterine epithelial apoptosis while markedly elevating Birc1 transcript level in an estrogen receptor-alpha-dependent manner. The induction of Birc1 before any effect on apoptosis suppression and failure of diethylstilbestrol to completely inhibit apoptosis in Birc1a-deficient uterine epithelium indicate a functional role for Birc1a in estrogen-mediated apoptosis suppression. In ovariectomized adult mice, expression of Birc1 is also induced by ovarian hormones, suggesting a role for these proteins in normal uterine physiology. We propose that by binding to active caspases, Birc1 proteins can eliminate them through proteasome degradation. These results for the first time establish Birc1 proteins as functional targets of estrogen in suppressing apoptosis in the uterus.
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Affiliation(s)
- Yan Yin
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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78
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Psarra AMG, Sekeris CE. Nuclear receptors and other nuclear transcription factors in mitochondria: regulatory molecules in a new environment. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1783:1-11. [PMID: 18062929 DOI: 10.1016/j.bbamcr.2007.10.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 10/27/2007] [Accepted: 10/29/2007] [Indexed: 12/25/2022]
Abstract
The mitochondrion is the major energy generating organelle of the cell and the site of other basic processes, including apoptosis. The mitochondrial functions are performed in concert with other cell compartments and are regulated by various extracellular and intracellular signals. Several nuclear receptors and other nuclear transcription factors, such as NF-kappa B, AP-1, CREB and p53, involved in growth, metabolic and developmental processes, have been detected in mitochondria. This finding raises the question as to the role of these regulatory molecules in their "new" environment. Experimental evidence supports the action of the mitochondrially localized transcription factors on mitochondrial transcription, energy yield and apoptosis, extending the known nuclear role of these molecules outside the nucleus. A principle of coordination of nuclear and mitochondrial gene transcription has been ascertained as regards the regulatory action of steroid and thyroid hormones on energy yield. Accordingly, the same nuclear receptors, localized in the two compartments-nuclei and mitochondria-regulate transcription of genes serving a common function by way of interaction with common binding sites in the two genomes. This principle is now expanding to encompass other nuclearly and mitochondrially localized transcription factors.
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Affiliation(s)
- Anna-Maria G Psarra
- Biomedical Research Foundation, Academy of Athens, Center for Basic Research, 4 Soranou Efesiou, 11527, Athens, Greece
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79
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Choudhry MA, Chaudry IH. 17beta-Estradiol: a novel hormone for improving immune and cardiovascular responses following trauma-hemorrhage. J Leukoc Biol 2007; 83:518-22. [PMID: 17938275 DOI: 10.1189/jlb.0607369] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
17beta-Estradiol (i.e., estrogen or E2) is a female sex steroid, which plays an essential role in female reproductive physiology. However, several lines of evidence indicate that in addition to its role in reproductive physiology, E2 is critical for maintaining many other organ functions in stress conditions. These include immune, cardiovascular, and neuronal functions, as well as regulation of skin, bone, and lipid metabolism. Studies have examined the role of E2 as an adjunct in post-trauma responses, and this article will review whether E2 as an adjunct to fluid resuscitation following trauma-hemorrhage plays any role in improving/restoring immune and cardiovascular functions.
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Affiliation(s)
- Mashkoor A Choudhry
- Center for Surgical Research and Department of Surgery, The University of Alabama at Birmingham, 1670 University Blvd., Birmingham, AL 35294-0019, USA
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80
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Lahm T, Crisostomo PR, Markel TA, Wang M, Lillemoe KD, Meldrum DR. The critical role of vascular endothelial growth factor in pulmonary vascular remodeling after lung injury. Shock 2007; 28:4-14. [PMID: 17510598 DOI: 10.1097/shk.0b013e31804d1998] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The pulmonary vascular endothelial cell plays a crucial role in the regulation of the pulmonary vascular tone and in the maintenance of the barrier function and integrity of the alveolar-capillary membrane. It also plays a major role in coagulation, fibrinolysis, and angiogenesis and participates in inflammatory reactions. Vascular endothelial growth factor (VEGF) is a central growth and survival factor for the endothelial cell. Particularly high levels of VEGF are expressed in the lungs, reflecting the critical role of VEGF for lung development and structural integrity of the adult lung. Vascular endothelial growth factor exerts a variety of physiological and pathophysiological actions in the lung. Recent evidence suggests its involvement in the pathogenesis of lung diseases such as bronchopulmonary dysplasia, acute lung injury, emphysema, and pulmonary hypertension. To summarize the critical effects of VEGF on the pulmonary endothelial cell in the pathogenesis of these diseases, the purposes of this review are to (1) discuss the biological activities and intracellular signaling pathways of VEGF in the lung; (2) summarize the regulatory mechanisms involved in VEGF expression; (3)address the effects of VEGF on endothelial cells in hyperoxia-induced and other forms of lung injury; (4) highlight the endothelial effects of VEGF in the pathogenesis of emphysema; and (5) explore the role of VEGF in the pathogenesis of pulmonary arterial hypertension.
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Affiliation(s)
- Tim Lahm
- Departments of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
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81
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Hsieh YC, Frink M, Choudhry MA, Bland KI, Chaudry IH. Metabolic modulators following trauma sepsis: Sex hormones. Crit Care Med 2007; 35:S621-9. [PMID: 17713419 DOI: 10.1097/01.ccm.0000278603.18687.4f] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The development of metabolic perturbations following severe trauma/sepsis leading to decreased energy production, hyperglycemia, and lipolysis is often rapid. Gender is increasingly recognized as a major factor in the outcome of patients suffering from trauma/sepsis. Moreover, sex hormones influence energy, glucose, and lipid metabolism. Metabolic modulators, such as peroxisome proliferator-activated receptor-gamma coactivator-1 and peroxisome proliferator-activated receptor-alpha, which are required for mitochondrial energy production and fatty acid oxidation, are regulated by the estrogen receptor-beta and consequently contribute to cardioprotection following trauma hemorrhage. Additionally, sex steroids regulate inflammatory cytokines that cause hypermetabolism/catabolism via acute phase response, leading to increased morbidity and mortality. MEASUREMENTS This article examines the following: (1) the evidence for gender differences; (2) energy, glucose, and lipid metabolism and the acute phase protein response; (3) the mechanisms by which gender/sex hormones affect the metabolic modulators; and (4) the tissue-specific effect of sex hormone receptors and the effect of genomic and nongenomic pathways of sex hormones following trauma. RESULTS AND CONCLUSIONS The available information indicates that sex steroids not only modulate the immune/cardiovascular responses but also influence various metabolic processes following trauma. Thus, alteration or modulation of the prevailing hormone milieu at the time of injury appears to be a novel therapeutic adjunct for improving outcome after injury.
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Affiliation(s)
- Ya-Ching Hsieh
- Center for Surgical Research and Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA
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82
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Paquette A, Wang D, Gauthier MS, Prud'homme D, Jankowski M, Gutkowska J, Lavoie JM. Specific adaptations of estrogen receptor alpha and beta transcripts in liver and heart after endurance training in rats. Mol Cell Biochem 2007; 306:179-87. [PMID: 17668153 DOI: 10.1007/s11010-007-9568-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 07/12/2007] [Indexed: 11/30/2022]
Abstract
Estrogens exert their biological roles mainly through estrogen receptors (ER) that function as ligand-activated transcription factors. ER content in a cell is regulated by many factors and is decisive for estrogen action. The purpose of the present study was to investigate the influence of an 8-wk endurance training program on ER expression in the liver, right atrium (RA), and left ventricle (LV) of intact and ovariectomized (Ovx) rats. We measured ERalpha and ERbeta mRNA content by reverse transcription-polymerase chain reaction (RT-PCR). We found an important increase in ERalpha mRNA levels in the liver (300%; P < 0.01) and in ERbeta mRNA levels in the RA (200%; P < 0.05), and a marked decrease in ERalpha (80%; P < 0.01) and ERbeta (40%; P < 0.05) transcripts content in the LV of intact rats after endurance training. On the other hand, ERalpha mRNA levels were depressed by 50% (P < 0.01) in the liver, and increased by 60% (P < 0.01) in LV of Ovx rats after exercise training. These results first indicate that endurance training is associated with modifications of ER transcripts levels in the liver, LV, and RA of female rats. More specifically, these effects are tissue and isoform-specific and the direction of the response (increase or decrease) is different in intact and Ovx rats. It is suggested that some of the adaptations to endurance training in liver and heart may be mediated by an ER-dependent mechanism.
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Affiliation(s)
- Amélie Paquette
- Département de kinésiologie, Université de Montréal, C.P. 6128, Succ. centre-ville, Montreal, QC, Canada H3C 3J7
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83
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Terrell AM, Crisostomo PR, Markel TA, Wang M, Abarbanell AM, Herrmann JL, Meldrum DR. Postischemic infusion of 17-beta-estradiol protects myocardial function and viability. J Surg Res 2007; 146:218-24. [PMID: 17644110 PMCID: PMC2390775 DOI: 10.1016/j.jss.2007.05.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/16/2007] [Accepted: 05/21/2007] [Indexed: 12/31/2022]
Abstract
BACKGROUND Females demonstrate improved cardiac recovery after ischemia/reperfusion injury compared with males. Attenuation of myocardial dysfunction with preischemic estradiol suggests that estrogen may be an important mediator of this cardioprotection. However, it remains unclear whether post-injury estradiol may have clinical potential in the treatment of acute myocardial infarction. We hypothesize that postischemic administration of 17beta-estradiol will decrease myocardial ischemia/reperfusion injury and improve left ventricular cardiac function. MATERIALS AND METHODS Adult male Sprague Dawley rat hearts (n = 20) (Harlan, Indianapolis, IN) were isolated, perfused with Krebs-Henseleit solution via Langendorff model, and subjected to 15 min of equilibration, 25 min of warm ischemia, and 40 min reperfusion. Experimental hearts received postischemic 17beta-estradiol infusion, 1 nm (n = 4), 10 nm (n = 4), 25 nm (n = 4), or 50 nm (n = 4), throughout reperfusion. Control hearts (n = 4) were infused with perfusate vehicle. RESULTS Postischemic recovery of left ventricular developed pressure was significantly greater with 1 nm (51.6% +/- 7.4%) and 10 nm estradiol (47.7% +/- 8.6%) than with vehicle (37.8% +/- 9.7%) at end reperfusion. There was also greater recovery of the end diastolic pressure with 1 nm (47.8 +/- 4.0 mmHg) and 10 nm estradiol (54.0 +/- 4.0) compared with vehicle (75.3 +/- 7.5). Further, 1 nm and 10 nm estrogen preserved coronary flow after ischemia and decreased coronary effluent lactated dehydrogenase compared with controls. Estrogen at 25 nm and 50 nm did not provide additional benefit in terms of functional recovery. Estrogen at all concentrations increased extracellular signal-regulated protein kinase phosphorylation. CONCLUSIONS Postischemic infusion of 17beta-estradiol protects myocardial function and viability. The attractive potential for the clinical application of postischemic estrogen therapy warrants further study to elucidate the mechanistic pathways and differences between males and females.
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Affiliation(s)
- Andrew M. Terrell
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Paul R. Crisostomo
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Troy A. Markel
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Meijing Wang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Aaron M. Abarbanell
- Department of Pulmonary and Critical Care, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jeremy L. Herrmann
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Daniel R. Meldrum
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Immunobiology, Indiana University School of Medicine, Indianapolis, Indiana
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84
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Spolarics Z. The X-files of inflammation: cellular mosaicism of X-linked polymorphic genes and the female advantage in the host response to injury and infection. Shock 2007; 27:597-604. [PMID: 17505297 DOI: 10.1097/shk.0b013e31802e40bd] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Females as compared with males display better general health status, longevity, and improved clinical course after injury and infection. It is generally believed that the female advantage is associated with the effects of sex hormones. This review argues that the sex benefit of females during the host response is associated with polymorphism of X-linked genes and cellular mosaicism for X-linked parental alleles. Cells from females carry both parental X chromosomes (maternal, Xm; or paternal, Xp), whereas males carry only one (Xm). Because of dosage compensation and random X inactivation, half of the cells from females express either Xm or Xp. Therefore, females are cellular mosaics for their X-linked polymorphic genes. This cellular mosaicism in females represents a more adaptive and balanced cellular machinery that is advantageous during the innate immune response. Several genes encoding key metabolic and regulatory proteins reside on the X chromosome, including members of the apoptotic cascade, hormone homeostasis, glucose metabolic enzymes, superoxide-producing machinery, and the toll-like receptor/nuclear factor kappaB/c-Jun N-terminal kinase signaling pathway. Polymorphic forms of these X-linked proteins are likely to manifest in phenotypic differences in the mosaic cell populations in females and may contribute to sex-related differences in the host response to injury and infection. The unique inheritance pattern of X-linked polymorphisms and their potential confounding effects in clinical trials are also discussed; furthermore, we present potential biomarkers for studying mosaic cell populations of innate immunity.
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Affiliation(s)
- Zoltán Spolarics
- Department of Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103, USA.
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85
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Chen JQ, Russo PA, Cooke C, Russo IH, Russo J. ERbeta shifts from mitochondria to nucleus during estrogen-induced neoplastic transformation of human breast epithelial cells and is involved in estrogen-induced synthesis of mitochondrial respiratory chain proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:1732-46. [PMID: 17604135 DOI: 10.1016/j.bbamcr.2007.05.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 04/28/2007] [Accepted: 05/10/2007] [Indexed: 02/06/2023]
Abstract
Both estrogen receptors (ER) alpha (ERalpha) and beta (ERbeta) are localized in the nucleus, plasma membrane, and mitochondria, where they mediate the different physiological effects of estrogens. It has been observed that the relative subcellular localization of ERs is altered in several cancer cells. We have demonstrated that MCF-10F cells, the immortal and non-tumorigenic human breast epithelial cells (HBEC) that are ERalpha-negative and ERbeta-positive, are transformed in vitro by 17beta-estradiol (E(2)), generating highly invasive cells that are tumorigenic in severe combined immunodeficient mice. E(2)-transformed MCF-10F (trMCF) cells exhibit progressive loss of ductulogenesis, invasive (bsMCF) and tumorigenic (caMCF) phenotypes. Immunolocalization of ERbeta by confocal fluorescent microscopy and electron microscopy revealed that ERbeta is predominantly localized in mitochondria of MCF-10F and trMCF cells. Silencing ERbeta expression with ERbeta-specific small interference RNA (siRNA-ERbeta) markedly diminishes both nuclear and mitochondrial ERbeta in MCF-10F cells. The ERbeta shifts from its predominant localization in the mitochondria of MCF-10F and trMCF cells to the nucleus of bsMCF cells, becoming predominantly nuclear in caMCF cells. Furthermore, we demonstrated that the mitochondrial ERbeta in MCF-10F cells is involved in E(2)-induced expression of mitochondrial DNA (mtDNA)-encoded respiratory chain (MRC) proteins. This is the first report of an association of changes in the subcellular localization of ERbeta with various stages of E(2)-induced transformation of HBEC and a functional role of mitochondrial ERbeta in mediating E(2)-induced MRC protein synthesis. Our findings provide a new insight into one of the potential roles of ERbeta in human breast cancer.
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Affiliation(s)
- Jin-Qiang Chen
- Breast Cancer Research Laboratory, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111-2497, USA.
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86
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Abstract
A number of epidemiological and animal studies have suggested a cardioprotective role for estrogen. This review will focus on the cardioprotective role of estrogen in ischemia-reperfusion injury. Estrogen binding to receptors can lead to altered gene expression and estrogen has been shown to induce expression of a number of genes that have been suggested to be important in cardioprotection. Estrogen is reported to increase expression of the plasma membrane glucose transporter GLUT4 and to increase carbohydrate metabolism. Estrogen has also been reported to increase mitochondrial biogenesis and to alter mitochondrial generation of reactive oxygen species. Estrogen results in upregulation of cardiac eNOS and nNOS, which have been shown previously to be important mediators of cardioprotection. Nitric oxide has been shown to result in S-nitrosylation and inhibition of the L-type calcium channel, thereby reducing calcium loading during ischemia. Nitric oxide has also been reported to inhibit complex I and inhibition of complex I has been reported to reduce activation of the mitochondrial permeability transition pore. Nitric oxide has been shown to result in activation of the mitochondrial K(ATP) channel, which has been shown to be involved in cardioprotection. Estrogen can also activate rapid non-genomic pathways that activate cardioprotective-signaling pathways such as the phosphatidylinositol-3-kinase (PI-3 kinase) pathway which has also been shown to initiate protection. Taken together, estrogen by genomic and non-genomic pathways can result in the initiation of a number of signaling pathways that enhance cardioprotection.
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Affiliation(s)
- Elizabeth Murphy
- Head Cardiac Physiology Section, Vascular Medicine Branch, National Heart, Lung, and Blood Institute/NIH, 10 Center Drive, Bethesda, MD 20892, USA.
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87
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Hsieh YC, Yu HP, Frink M, Suzuki T, Choudhry MA, Schwacha MG, Chaudry IH. G protein-coupled receptor 30-dependent protein kinase A pathway is critical in nongenomic effects of estrogen in attenuating liver injury after trauma-hemorrhage. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:1210-8. [PMID: 17392161 PMCID: PMC1829455 DOI: 10.2353/ajpath.2007.060883] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Although nongenomic effects of 17beta-estradiol (E2) are mediated via the estrogen receptor alpha (ER-alpha), the existence of another novel ER, G protein-coupled receptor 30 (GPR30), has been suggested as a candidate for triggering a broad range of E2-mediated signaling. GPR30 also acts independently of the ER to promote activation of the protein kinase A (PKA) pathway, which protects cells from apoptosis through Bcl-2. In this study, we examined whether the salutary effects of E2 in attenuating hepatic injury after trauma-hemorrhage are mediated via GPR30- or ER-alpha-regulated activation of PKA-dependent signaling. At 2 hours after trauma-hemorrhage, administration of E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) or E2 induced the up-regulation of ER-alpha and GPR30 and attenuated hepatic injury. This was accompanied by increases in PKA activity and Bcl-2 expression. Inhibition of PKA in E2-BSA-treated trauma-hemorrhage rats by PKA inhibitor H89 prevented the E2-BSA attenuation of hepatic injury. Isolated hepatocytes were transfected with small interfering RNA to suppress GPR30 or ER. We found that suppression of GPR30 but not ER-alpha prevented E2-BSA- or E2-induced PKA activation and Bcl-2 expression. These results suggest that the nongenomic salutary effect of E2 in reducing hepatic injury after trauma-hemorrhage is mediated through the PKA-dependent pathway via GPR30 but not ER-alpha.
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MESH Headings
- Animals
- Blotting, Western
- Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Estradiol/administration & dosage
- Estradiol/pharmacology
- Estradiol/therapeutic use
- Estrogen Receptor alpha/genetics
- Estrogen Receptor alpha/metabolism
- Estrogens, Conjugated (USP)/administration & dosage
- Estrogens, Conjugated (USP)/pharmacology
- Estrogens, Conjugated (USP)/therapeutic use
- Glutathione Transferase/blood
- Hemorrhage/blood
- Hemorrhage/etiology
- Hemorrhage/prevention & control
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Isoenzymes/blood
- Isoquinolines/administration & dosage
- Isoquinolines/pharmacology
- Liver/drug effects
- Liver/injuries
- Liver/metabolism
- Male
- Models, Biological
- Protein Kinase Inhibitors/pharmacology
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA, Small Interfering/genetics
- Rats
- Rats, Sprague-Dawley
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Serum Albumin, Bovine/administration & dosage
- Serum Albumin, Bovine/pharmacology
- Serum Albumin, Bovine/therapeutic use
- Signal Transduction/drug effects
- Sulfonamides/administration & dosage
- Sulfonamides/pharmacology
- Transfection
- Wounds and Injuries/complications
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Affiliation(s)
- Ya-Ching Hsieh
- Center for Surgical Research, University of Alabama at Birmingham, 1670 University Blvd., Volker Hall, Room G094, Birmingham, AL 35294-0019, USA
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88
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DonCarlos LL, Azcoitia I, Garcia-Segura LM. In search of neuroprotective therapies based on the mechanisms of estrogens. Expert Rev Endocrinol Metab 2007; 2:387-397. [PMID: 30743812 DOI: 10.1586/17446651.2.3.387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Although estradiol is a neuroprotective factor, estrogen therapy in older women increases the risk of adverse cognitive outcomes and poses additional peripheral risks, requiring careful use of estrogenic compounds as treatments for neurodegenerative conditions or neural injury. Potential alternatives to estrogen therapy to promote neuroprotection might include treatment with molecules that are able to interact with estrogen receptors, with alternative mechanisms of action, or with molecules that induce local estradiol synthesis in the brain, or a combination of all. However, before considering the broad clinical applications, more basic research is required to clarify the mechanisms of action and potential risks of some of these estrogen-based treatments.
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Affiliation(s)
- Lydia L DonCarlos
- a Professor, Loyola University Chicago, Department of Cell Biology, Neurobiology and Anatomy, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA.
| | - Iñigo Azcoitia
- b Associate Professor, Universidad Complutense, Departamento de Biología Celular, Facultad de Biología, E-28040 Madrid, Spain.
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89
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Yager JD, Chen JQ. Mitochondrial estrogen receptors--new insights into specific functions. Trends Endocrinol Metab 2007; 18:89-91. [PMID: 17324583 DOI: 10.1016/j.tem.2007.02.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 01/17/2007] [Accepted: 02/14/2007] [Indexed: 11/18/2022]
Abstract
Estrogen receptor (ER) alpha and ERbeta are present in mitochondria but little is known about their contribution to the overall constellation of cellular responses to 17beta-estradiol, which inhibits the early stages of apoptosis through membrane and mitochondrial, but not nuclear, ER signaling pathways. Whereas membrane ER signaling leading to inhibition of apoptosis involves the activation of protein kinase pathways, mitochondrial ER-mediated inhibition involves the direct and/or indirect activation of manganese superoxide dismutase by the mitochondrial ER.
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Affiliation(s)
- James D Yager
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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