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Sahoo DK, Chainy GBN. Hormone-linked redox status and its modulation by antioxidants. VITAMINS AND HORMONES 2023; 121:197-246. [PMID: 36707135 DOI: 10.1016/bs.vh.2022.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Hormones have been considered as key factors involved in the maintenance of the redox status of the body. We are making considerable progress in understanding interactions between the endocrine system, redox status, and oxidative stress with the dynamics of life, which encompasses fertilization, development, growth, aging, and various pathophysiological states. One of the reasons for changes in redox states of vertebrates leading to oxidative stress scenario is the disruption of the endocrine system. Comprehending the dynamics of hormonal status to redox state and oxidative stress in living systems is challenging. It is more difficult to come to a unifying conclusion when some hormones exhibit oxidant properties while others have antioxidant features. There is a very limited approach to correlate alteration in titers of hormones with redox status and oxidative stress with growth, development, aging, and pathophysiological stress. The situation is further complicated when considering various tissues and sexes in vertebrates. This chapter discusses the beneficial impacts of hormones with antioxidative properties, such as melatonin, glucagon, insulin, estrogens, and progesterone, which protect cells from oxidative damage and reduce pathophysiological effects. Additionally, we discuss the protective effects of antioxidants like vitamins A, E, and C, curcumin, tempol, N-acetyl cysteine, α-lipoic acid, date palm pollen extract, resveratrol, and flavonoids on oxidative stress triggered by hormones such as aldosterone, glucocorticoids, thyroid hormones, and catecholamines. Inflammation, pathophysiology, and the aging process can all be controlled by understanding how antioxidants and hormones operate together to maintain cellular redox status. Identifying the hormonal changes and the action of antioxidants may help in developing new therapeutic strategies for hormonal imbalance-related disorders.
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Affiliation(s)
- Dipak Kumar Sahoo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa States University, Ames, IA, United States.
| | - Gagan B N Chainy
- Department of Biotechnology, Utkal University, Bhubaneswar, Odisha, India
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2
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The interaction of steroids with phospholipid bilayers and membranes. Biophys Rev 2021; 14:163-179. [DOI: 10.1007/s12551-021-00918-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/18/2021] [Indexed: 12/13/2022] Open
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Chu S, Maples MM, Bryant SJ. Cell encapsulation spatially alters crosslink density of poly(ethylene glycol) hydrogels formed from free-radical polymerizations. Acta Biomater 2020; 109:37-50. [PMID: 32268243 PMCID: PMC7649065 DOI: 10.1016/j.actbio.2020.03.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 03/10/2020] [Accepted: 03/24/2020] [Indexed: 11/26/2022]
Abstract
Photopolymerizable poly(ethylene glycol) (PEG) hydrogels are a promising platform for chondrocyte encapsulation and cartilage tissue engineering. This study demonstrates that during the process of encapsulation, chondrocytes alter the formation of PEG hydrogels leading to a reduction in the bulk and local hydrogel crosslink density. Freshly isolated chondrocytes were shown to interact with hydrogel precursors, in part through thiol-mediated events between dithiol crosslinkers and cell surface free thiols, depleting crosslinker concentration and causing a reduction in the bulk hydrogel crosslink density. This effect was more pronounced with increasing cell density at the time of encapsulation. Encapsulation of chondrocytes in fluorescently labeled hydrogels exhibited a gradient in hydrogel density around the cell, which was abrogated by treatment of the cells with the antioxidant estradiol prior to encapsulation. This gradient led to spatial variations in the degradation behavior of a hydrolytically degradable PEG hydrogel, creating regions devoid of hydrogel surrounding cells. Collectively, findings from this study indicate that the antioxidant defense mechanisms in chondrocytes alter the resultant properties of PEG hydrogels formed by free-radical polymerizations. These interactions will have a significant impact on tissue engineering, affecting the local microenvironment around cells and how tissue grows within the hydrogels. STATEMENT OF SIGNIFICANCE: Cell encapsulations in synthetic hydrogels formed by free-radical polymerizations offer numerous benefits for tissue engineering. Herein, we studied cartilage cells and identified that during encapsulation, cells interfered with hydrogel formation through two distinct mechanisms. Thiol-mediated events between monomers led to monomer depletion and a lower crosslinked hydrogel. Cells' antioxidant defense mechanisms interfered with free-radicals and inhibited hydrogel formation near the cell. These cell-mediated effects led to softer hydrogels and created unique hydrogel degradations patterns causing rapid degradation around the cells. The latter has benefits for tissue engineering, where these regions provide space for tissue growth. Overall, this study demonstrates that cells play a key role in how the hydrogel structure forms when cells are present.
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Affiliation(s)
- Stanley Chu
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, United States
| | - Mollie M Maples
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, United States
| | - Stephanie J Bryant
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, United States; Materials Science and Engineering Program, University of Colorado, Boulder, CO, United States; Biofrontiers Institute, University of Colorado, Boulder, CO, United States.
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4
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Biophysical methods: Complementary tools to study the influence of human steroid hormones on the liposome membrane properties. Biochimie 2018; 153:13-25. [DOI: 10.1016/j.biochi.2018.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/07/2018] [Indexed: 11/21/2022]
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Engler-Chiurazzi EB, Brown CM, Povroznik JM, Simpkins JW. Estrogens as neuroprotectants: Estrogenic actions in the context of cognitive aging and brain injury. Prog Neurobiol 2017; 157:188-211. [PMID: 26891883 PMCID: PMC4985492 DOI: 10.1016/j.pneurobio.2015.12.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/06/2015] [Accepted: 12/10/2015] [Indexed: 12/30/2022]
Abstract
There is ample empirical evidence to support the notion that the biological impacts of estrogen extend beyond the gonads to other bodily systems, including the brain and behavior. Converging preclinical findings have indicated a neuroprotective role for estrogen in a variety of experimental models of cognitive function and brain insult. However, the surprising null or even detrimental findings of several large clinical trials evaluating the ability of estrogen-containing hormone treatments to protect against age-related brain changes and insults, including cognitive aging and brain injury, led to hesitation by both clinicians and patients in the use of exogenous estrogenic treatments for nervous system outcomes. That estrogen-containing therapies are used by tens of millions of women for a variety of health-related applications across the lifespan has made identifying conditions under which benefits with estrogen treatment will be realized an important public health issue. Here we provide a summary of the biological actions of estrogen and estrogen-containing formulations in the context of aging, cognition, stroke, and traumatic brain injury. We have devoted special attention to highlighting the notion that estrogen appears to be a conditional neuroprotectant whose efficacy is modulated by several interacting factors. By developing criteria standards for desired beneficial peripheral and neuroprotective outcomes among unique patient populations, we can optimize estrogen treatments for attenuating the consequences of, and perhaps even preventing, cognitive aging and brain injury.
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Affiliation(s)
- E B Engler-Chiurazzi
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, United States.
| | - C M Brown
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Neurobiology and Anatomy, West Virginia University, Morgantown, WV 26506, United States.
| | - J M Povroznik
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Pediatrics, West Virginia University, Morgantown, WV 26506, United States.
| | - J W Simpkins
- Center for Basic and Translational Stroke Research, West Virginia University, Morgantown, WV 26506, United States; Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, United States.
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6
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Effect of Progesterone, Its Hydroxylated and Methylated Derivatives, and Dydrogesterone on Lipid Bilayer Membranes. J Membr Biol 2015; 248:811-24. [DOI: 10.1007/s00232-015-9803-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/12/2015] [Indexed: 10/23/2022]
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Hutchens MP, Kosaka Y, Zhang W, Fujiyoshi T, Murphy S, Alkayed N, Anderson S. Estrogen-mediated renoprotection following cardiac arrest and cardiopulmonary resuscitation is robust to GPR30 gene deletion. PLoS One 2014; 9:e99910. [PMID: 24923556 PMCID: PMC4055725 DOI: 10.1371/journal.pone.0099910] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 05/19/2014] [Indexed: 11/23/2022] Open
Abstract
Introduction Acute kidney injury is a serious,sexually dimorphic perioperative complication, primarily attributed to hypoperfusion. We previously found that estradiol is renoprotective after cardiac arrest and cardiopulmonary resuscitation in ovariectomized female mice. Additionally, we found that neither estrogen receptor alpha nor beta mediated this effect. We hypothesized that the G protein estrogen receptor (GPR30) mediates the renoprotective effect of estrogen. Methods Ovariectomized female and gonadally intact male wild-type and GPR30 gene-deleted mice were treated with either vehicle or 17β-estradiol for 7 days, then subjected to cardiac arrest and cardiopulmonary resuscitation. Twenty four hours later, serum creatinine and urea nitrogen were measured, and histologic renal injury was evaluated by unbiased stereology. Results In both males and females, GPR30 gene deletion was associated with reduced serum creatinine regardless of treatment. Estrogen treatment of GPR30 gene-deleted males and females was associated with increased preprocedural weight. In ovariectomized female mice, estrogen treatment did not alter resuscitation, but was renoprotective regardless of GPR30 gene deletion. In males, estrogen reduced the time-to-resuscitate and epinephrine required. In wild-type male mice, serum creatinine was reduced, but neither serum urea nitrogen nor histologic outcomes were affected by estrogen treatment. In GPR30 gene-deleted males, estrogen did not alter renal outcomes. Similarly, renal injury was not affected by G1 therapy of ovariectomized female wild-type mice. Conclusion Treatment with 17β-estradiol is renoprotective after whole-body ischemia-reperfusion in ovariectomized female mice irrespective of GPR30 gene deletion. Treatment with the GPR30 agonist G1 did not alter renal outcome in females. We conclude GPR30 does not mediate the renoprotective effect of estrogen in ovariectomized female mice. In males, estrogen therapy was not renoprotective. Estrogen treatment of GPR30 gene-deleted mice was associated with increased preprocedural weight in both sexes. Of significance to further investigation, GPR30 gene deletion was associated with reduced serum creatinine, regardless of treatment.
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Affiliation(s)
- Michael P. Hutchens
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Yasuharu Kosaka
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Wenri Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Tetsuhiro Fujiyoshi
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Stephanie Murphy
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Nabil Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Sharon Anderson
- Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, Oregon, United States of America
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Khodabandehloo F, Hosseini M, Rajaei Z, Soukhtanloo M, Farrokhi E, Rezaeipour M. Brain tissue oxidative damage as a possible mechanism for the deleterious effect of a chronic high dose of estradiol on learning and memory in ovariectomized rats. ARQUIVOS DE NEURO-PSIQUIATRIA 2013; 71:313-9. [DOI: 10.1590/0004-282x20130027] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 12/12/2012] [Indexed: 11/21/2022]
Abstract
In addition to antioxidative effects, estrogens also exert pro-oxidative actions. The effect of chronic administration of a high dose of estradiol valerate on Morris water maze tasks and brain tissues oxidative damage was investigated. The Sham-Est and OVX-Est groups were treated with estradiol valerate (4 mg/kg) for 12 weeks. Escape latency and traveled path in the Sham-Est and OVX-Est groups were significantly higher than in the Sham and OVX groups (p≪0.01 and p≪0.001). In the probe trial, the animals of the Sham-Est and OVX-Est groups spent lower time in Q1 compared to Sham and OVX groups (p≪0.05 and p≪0.001). In Sham-Est and OVX-Est groups, the brain tissue total thiol concentration was significantly lower, and malondialdehyde (MDA) concentrations were higher than in the Sham and OVX groups (p≪0.05 and p≪0.001). It is concluded that administration of high exogenous levels of estradiol impairs performance and enhances oxidative stress.
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Affiliation(s)
| | | | - Ziba Rajaei
- Isfahan University of Medical Sciences, Iran
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9
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Wilson ME. Stroke: understanding the differences between males and females. Pflugers Arch 2013; 465:595-600. [PMID: 23503729 DOI: 10.1007/s00424-013-1260-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/01/2013] [Accepted: 03/01/2013] [Indexed: 01/09/2023]
Abstract
Stroke is a significant cause of death and long-term disability in the USA. The incidence, mortality, and outcomes of stroke are significantly different between men and women. As with many diseases that affect men and women differently, an understanding on the reasons underlying those differences is critical to effective diagnosis and treatment. This review will examine the sex differences in stroke in both humans and animal models of stroke and review what is known about potential mechanisms underlying these differences. It is clear that there is a complex interaction between hormonal, genetic, and unknown factors at play in generating the sex differences in stroke.
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Affiliation(s)
- Melinda E Wilson
- Department of Physiology, University of Kentucky, MS508 800 Rose St., Lexington, KY 40536, USA.
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10
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Richardson TE, Simpkins JW. R- and S-equol have equivalent cytoprotective effects in Friedreich's ataxia. BMC Pharmacol Toxicol 2012; 13:12. [PMID: 23088310 PMCID: PMC3506265 DOI: 10.1186/2050-6511-13-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 09/25/2012] [Indexed: 12/01/2022] Open
Abstract
Background Estradiol (E2) is a very potent cytoprotectant against a wide variety of cellular insults in numerous different cell models, including a Friedreich’s ataxia (FRDA) model. Previously, we demonstrated that estrogen-like compounds are able to prevent cell death in an FRDA model independent of any known estrogen receptor (ER) by reducing reactive oxygen species (ROS) and the detrimental downstream effects of ROS buildup including oxidative damage to proteins and lipids and impaired mitochondrial function. Results We have previously demonstrated by western blot that our cell model lacks ERα and expresses only very low levels of ERβ. Using L-buthionine (S,R)-sulfoximine (BSO) to induce oxidative stress in human FRDA fibroblasts, we determine the potency and efficacy of the soy-derived ERβ agonist S-equol and its ERα-preferring enantiomer, R-equol in vitro on cell viability and ROS accumulation. Here we demonstrate that these equol biphenolic compounds, while significantly less potent and efficacious than E2, provide statistically similar attenuation of ROS and cytoprotection against a BSO-induced oxidative insult. Conclusions These preliminary data demonstrate that estrogen and soy-derived equols could have a beneficial effect in delaying the onset and decreasing the severity of symptoms in FRDA patients by an antioxidant mechanism. In addition, these data confirm that the protection seen previously with E2 was indeed unrelated to ER binding.
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Affiliation(s)
- Timothy E Richardson
- Institute for Aging and Alzheimer's Disease Research, Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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11
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Simpkins JW, Perez E, Wang X, Yang S, Wen Y, Singh M. The potential for estrogens in preventing Alzheimer's disease and vascular dementia. Ther Adv Neurol Disord 2011; 2:31-49. [PMID: 19890493 DOI: 10.1177/1756285608100427] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Estrogens are the best-studied class of drugs for potential use in the prevention of Alzheimer's disease (AD). These steroids have been shown to be potent neuroprotectants both in vitro and in vivo, and to exert effects that are consistent with their potential use in prevention of AD. These include the prevention of the processing of amyloid precursor protein (APP) into beta-amyloid (Aß), the reduction in tau hyperphosphorylation, and the elimination of catastrophic attempts at neuronal mitosis. Further, epidemiological data support the efficacy of early postmenopausal use of estrogens for the delay or prevention of AD. Collectively, this evidence supports the further development of estrogen-like compounds for prevention of AD. Several approaches to enhance brain specificity of estrogen action are now underway in an attempt to reduce the side effects of chronic estrogen therapy in AD.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, Center FOR HER (Focused On Resources for her Health, Education and Research), University of North Texas Health Science Center, Fort Worth, TX, USA
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12
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The assessment of non-feminizing estrogens for use in neuroprotection. Brain Res 2010; 1379:61-70. [PMID: 21111714 DOI: 10.1016/j.brainres.2010.11.058] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 11/03/2010] [Accepted: 11/18/2010] [Indexed: 11/22/2022]
Abstract
Menopause is associated with a precipitous decline in circulating estrogens and a resulting loss of the neuroprotective actions of this steroid hormone. In view of the results of the Women's Health Initiative and the preceding knowledge that orally administered estrogens has a variety of adverse side effects, likely through actions on peripheral estrogen receptor alpha (ERα), we initiated a program of research to synthesis and assess a group of non-feminizing estrogens that lack ability to interact with ERs but retain much of the neuroprotective action of feminizing estrogens. This program of research is aimed at the identification of compounds which do not stimulate ERs but are potentially neuroprotective in vitro and in animal models of neuronal cell death. We discovered that the most effective non-feminizing estrogens were those with large bulky groups in the 2 and/or 4 carbon of the phenolic A ring of the steroid. These compounds were 8- to 114-fold more potent than 17 β-estradiol (βE2), but lacked ER binding capacity in vitro and feminizing effects in vivo. The success of this program of research suggests that strategies to optimize non-feminizing estrogens for use in postmenopausal women can be successful.
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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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Brown AC, Wrenn SP, Suresh N, Meyers WC, Abedin MZ. Gender Differences in Cholesterol Nucleation in Native Bile: Estrogen Is a Potential Contributory Factor. J Membr Biol 2009; 232:35-45. [DOI: 10.1007/s00232-009-9214-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
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Pabón A, Deharo E, Zuluaga L, Maya JD, Saez J, Blair S. Plasmodium falciparum: Effect of Solanum nudum steroids on thiol contents and β-hematin formation in parasitized erythrocytes. Exp Parasitol 2009; 122:273-9. [DOI: 10.1016/j.exppara.2009.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 04/22/2009] [Accepted: 04/29/2009] [Indexed: 11/25/2022]
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Terrell J, Yadava P, Castro C, Hughes J. Liposome fluidity alters interactions between the ganglioside GM1 and cholera toxin B subunit. J Liposome Res 2008; 18:21-9. [PMID: 18348069 DOI: 10.1080/08982100801893929] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cholera toxin is a complex protein with a biologically active protein (A subunit) and a cell targeting portion (B subunit). The B subunit is responsible for specific cell binding and entry of the A subunit. One way to limit potential toxicity of the toxin after exposure is to introduce cellular decoys to bind the toxin before it can enter cells. In this study the ganglioside GM1, a natural ligand for cholera toxin, was incorporated into liposomes and the interaction between fluorescent B subunit and the liposome determined. Liposome membrane fluidity was determined to play a major role in the binding between liposomes and the cholera toxin B subunit. Liposomes with lower fluidity demonstrated greater binding with the B subunit. The findings from this study could have important implications on formulation strategies for liposome decoys of toxins.
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Affiliation(s)
- James Terrell
- Department of Pharmaceutics, University of Florida, Gainesville, FL 32611, USA
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Prokai-Tatrai K, Perjesi P, Rivera-Portalatin NM, Simpkins JW, Prokai L. Mechanistic investigations on the antioxidant action of a neuroprotective estrogen derivative. Steroids 2008; 73:280-8. [PMID: 18068745 PMCID: PMC2317824 DOI: 10.1016/j.steroids.2007.10.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Revised: 08/11/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
Abstract
Antioxidant action is an important component of the complex neuroprotective effect of estrogens. Combining theoretical prediction and subsequent experimental confirmation by chemical and in vitro paradigms, this study focused on the mechanistic aspects of hydroxyl radical scavenging by 17beta-butoxy-1,3,5(10)-estratrien-3-ol, a synthetic derivative of 17beta-estradiol with increased potency to inhibit lipid peroxidation and reduced affinity to estrogen-receptors compared to the endogenous hormone. In the process that acts as a "chemical shield," the phenolic A-ring turns into 10beta-hydroxy-17beta-butoxy-1,3,5(10)-estratrien-3-one, a non-aromatic para-quinol, upon capturing hydroxyl radicals, which results in the complete loss of estrogen-receptor affinity and antioxidant activity. However, the parent compound is apparently recovered in brain tissue from this para-quinol via enzyme-catalyzed NAD(P)H-dependent reductive aromatization without causing oxidative stress. Taken together, our report argues for a previously unrecognized antioxidant cycle for estrogen-derived compounds.
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Affiliation(s)
- Katalin Prokai-Tatrai
- Department of Pharmacology and Neuroscience, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Pal Perjesi
- Institute of Pharmaceutical Chemistry, University of Pecs, Pecs, Hungary
| | - Nilka M. Rivera-Portalatin
- Department of Molecular Biology and Immunology, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - James W. Simpkins
- Department of Pharmacology and Neuroscience, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Laszlo Prokai
- Department of Molecular Biology and Immunology, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
- Corresponding author. Tel.: +1-817-735-2206; Fax: +1-817-735-2118; E-mail address: (L. Prokai)
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Tsutsumi M, Denda M. Paradoxical effects of beta-estradiol on epidermal permeability barrier homeostasis. Br J Dermatol 2007; 157:776-9. [PMID: 17711527 DOI: 10.1111/j.1365-2133.2007.08115.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Previous studies have demonstrated that sex hormones modulate epidermal permeability barrier homeostasis, and when the balance of these hormones is altered at menopause or during the menstrual cycle, skin sensitivity or barrier function is changed. OBJECTIVES To observe the direct effects of sex hormones on epidermal homeostasis. METHODS We examined the effects of topical application of sex hormones on permeability barrier recovery after tape stripping in the hairless mouse. To avoid the influence of systemic hormonal alteration, we employed male animals. RESULTS Application of androgen (testosterone or androsterone) delayed the barrier recovery, and the delay was overcome by co-application of beta-estradiol. Progesterone also delayed the barrier recovery, but in this case the delay was enhanced by beta-estradiol. CONCLUSIONS These results suggest that changes in sex hormone balance might be associated with the skin dysfunction that often occurs during menopause, and at certain points during the menstrual cycle.
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Affiliation(s)
- M Tsutsumi
- Shiseido Research Center, 2-12-1 Fukuura, Kanazawa-ku, Yokohama 236-8643, Japan
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Simpkins JW, Dykens JA. Mitochondrial mechanisms of estrogen neuroprotection. ACTA ACUST UNITED AC 2007; 57:421-30. [PMID: 17512984 DOI: 10.1016/j.brainresrev.2007.04.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 04/20/2007] [Accepted: 04/21/2007] [Indexed: 11/19/2022]
Abstract
Oxidative stress, bioenergetic failure and mitochondrial dysfunction are all implicated in the etiology of neurodegenerative diseases such as Alzheimer's disease (AD). The mitochondrial involvement in neurodegenerative diseases reflects the regulatory role mitochondrial failure plays in both necrotic cell death and apoptosis. The potent feminizing hormone, 17 beta-estradiol (E2), is neuroprotective in a host of cell and animal models of stroke and neurodegenerative diseases. The discovery that 17alpha-estradiol, an isomer of E2, is equally as neuroprotective as E2 yet is >200-fold less active as a hormone, has permitted development of novel, more potent analogs where neuroprotection is independent of hormonal potency. Studies of structure-activity relationships and mitochondrial function have led to a mechanistic model in which these steroidal phenols intercalate into cell membranes where they block lipid peroxidation reactions, and are in turn recycled. Indeed, the parental estrogens and novel analogs stabilize mitochondria under Ca(2+) loading otherwise sufficient to collapse membrane potential. The neuroprotective and mitoprotective potencies for a series of estrogen analogs are significantly correlated, suggesting that these compounds prevent cell death in large measure by maintaining functionally intact mitochondria. This therapeutic strategy is germane not only to sudden mitochondrial failure in acute circumstances, such as during a stroke or myocardial infarction, but also to gradual mitochondrial dysfunction associated with chronic degenerative disorders such as AD.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, 3500 Camp Bowie Boul., Fort Worth, TX 76102, USA.
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Meier S, Andersen TC, Lind-Larsen K, Svardal A, Holmsen H. Effects of alkylphenols on glycerophospholipids and cholesterol in liver and brain from female Atlantic cod (Gadus morhua). Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:420-30. [PMID: 17344102 DOI: 10.1016/j.cbpc.2007.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 01/25/2007] [Accepted: 01/26/2007] [Indexed: 10/23/2022]
Abstract
Offshore oil production releases large amounts of lipophilic compounds in produced water into the ocean. In 2004, 143 million m(3) produced water, containing approximately 13 tons of long-chain (>C(4)) alkylphenols (AP), was discharged from installations in the Norwegian sector of the North Sea. Long-chain APs are known to cause endocrine disruption in a number of species. However, relatively little is known about their long-term effects in the marine environment. In the present study, Atlantic cod (Gadus morhua) were exposed (0.02 to 80 mg AP/kg) to a mixture (1:1:1:1) of APs (4-tert-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol and 4-n-heptylphenol) or 17 beta-estradiol (5 mg E2/kg) for 5 weeks and the effect on the fatty acid profile and cholesterol content in the membrane lipids from the liver and the brain was studied. We also determined the interaction between different para-substituted APs and glycerophospholipids (native phospholipids extracted from cod liver and brain) and model phosphatidylcholine (PC 16:0/22:6 n-3) in monolayers with the Langmuir-Blodget technique. The study demonstrated that APs and E2 alter the fatty acid profile in the polar lipids (PL) from the liver to contain more saturated fatty acids (SFA) and less n-3 polyunsaturated fatty acids (n-3 PUFA) compared with control. In the brain of the exposed groups a similar effect was demonstrated, although with higher saturation of the fatty acids found in the neutral lipids (mainly cholesterol ester), but not in the polar lipids. The AP and E2 exposure also gave a decline in the cholesterol levels in the brain. The in vitro studies showed that APs increased the mean molecular areas of the PLs in the monolayers at concentrations down to 5 microM, most likely due to intercalation of the APs between PL molecules. The increase in molecular area increased with the length of the alkyl side chain.
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Affiliation(s)
- Sonnich Meier
- Institute of Marine Research, Postbox 1870 Nordnes, 5817 Bergen, Norway.
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21
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Prokai L, Simpkins JW. Structure-nongenomic neuroprotection relationship of estrogens and estrogen-derived compounds. Pharmacol Ther 2007; 114:1-12. [PMID: 17336390 PMCID: PMC1905848 DOI: 10.1016/j.pharmthera.2007.01.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Accepted: 01/24/2007] [Indexed: 11/25/2022]
Abstract
Nongenomic estrogen signaling pathways involve extranuclear estrogen receptors or function independently from estrogen receptors. These pathways participate in neuroprotection elicited by the hormone. Additional nongenomic neuroprotective effects are attributable to antioxidant and antiinflammatory actions of estrogens. Numerous chemical modifications to afford neuroprotective compounds from estrogens while eliminating estrogenicity and maintaining or enhancing nongenomic neuroprotection have been described. This review highlights recent structure-activity studies that revealed the importance of antioxidant effects for neuroprotective estrogen analogues and derivatives.
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Affiliation(s)
- Laszlo Prokai
- Department of Molecular Biology & Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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22
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Abstract
Although the effect of estrogen replacement therapy on the incidence of the neurodegenerative disease such as Alzheimer's disease is controversial, experimental studies indicate that estrogen replacement to young adult animals is neuroprotective and that perimenopausal estrogen replacement is associated with a decreased incidence of Alzheimer's disease. Estrogen affects a wide variety of cellular processes that can protect neuronal health. This article considers the disruption of the blood-brain barrier in Alzheimer's disease and forwards the hypothesis that estrogen may preserve neural health by maintaining the integrity of the blood-brain barrier.
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Affiliation(s)
- Farida Sohrabji
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center College of Medicine, College Station, TX 77843, USA.
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Dykens JA, Moos WH, Howell N. Development of 17alpha-estradiol as a neuroprotective therapeutic agent: rationale and results from a phase I clinical study. Ann N Y Acad Sci 2006; 1052:116-35. [PMID: 16024755 DOI: 10.1196/annals.1347.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
17alpha-estradiol (17alpha-E2) differs from its isomer, the potent feminizing hormone 17beta-estradiol (17beta-E2), only in the stereochemistry at one carbon, but this is sufficient to render it at least 200-fold less active as a transactivating hormone. Despite its meager hormonal activity, 17alpha-E2 is as potent as 17beta-E2 in protecting a wide variety of cell types, including primary neurons, from a diverse array of lethal and etiologically relevant stressors, including amyloid toxicity, serum withdrawal, oxidative stress, excitotoxicity, and mitochondrial inhibition, among others. Moreover, both estradiol isomers have shown efficacy in animal models of stroke, Alzheimer's disease (AD), and Parkinson's disease (PD). Data from many labs have yielded a mechanistic model in which 17alpha-E2 intercalates into cell membranes, where it terminates lipid peroxidation chain reactions, thereby preserving membrane integrity, and where it in turn is redox cycled by glutathione or by NADPH through enzymatic coupling. Maintaining membrane integrity is critical to mitochondrial function, where loss of impermeability of the inner membrane initiates both necrotic and apoptotic pathways. Thus, by serving as a mitoprotectant, 17alpha-E2 forestalls cell death and could correspondingly provide therapeutic benefit in a host of degenerative diseases, including AD, PD, Friedreich's ataxia, and amyotrophic lateral sclerosis, while at the same time circumventing the common adverse effects elicited by more hormonally active analogues. Positive safety and pharmacokinetic data from a successful phase I clinical study with oral 17alpha-E2 (sodium sulfate conjugate) are presented here, and several options for its future clinical assessment are discussed.
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Affiliation(s)
- James A Dykens
- MIGENIX Corporation, 12780 High Bluff Dr., San Diego, CA 92130, USA.
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Singh M, Dykens JA, Simpkins JW. Novel mechanisms for estrogen-induced neuroprotection. Exp Biol Med (Maywood) 2006; 231:514-21. [PMID: 16636299 DOI: 10.1177/153537020623100505] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Estrogens are gonadal steroid hormones that are present in the circulation of both males and females and that can no longer be considered within the strict confines of reproductive function. In fact, the bone, the cardiovascular system, and extrahypothalamic regions of the brain are now well-established targets of estrogens. Among the numerous aspects of brain function regulated by estrogens are their effects on mood, cognitive function, and neuronal viability. Here, we review the supporting evidence for estrogens as neuroprotective agents and summarize the various mechanisms that may be involved in this effect, focusing particularly on the mitochondria as an important target. On the basis of this evidence, we discuss the clinical applicability of estrogens in treating various age-related disorders, including Alzheimer disease and stroke, and identify the caveats that must be considered.
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Affiliation(s)
- Meharvan Singh
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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Perez E, Cai ZY, Covey DF, Simpkins JW. Neuroprotective effects of estratriene analogs: structure-activity relationships and molecular optimization. Drug Dev Res 2006. [DOI: 10.1002/ddr.20047] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sribnick EA, Ray SK, Banik NL. Estrogen prevents glutamate-induced apoptosis in C6 glioma cells by a receptor-mediated mechanism. Neuroscience 2005; 137:197-209. [PMID: 16289585 DOI: 10.1016/j.neuroscience.2005.08.074] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2005] [Revised: 06/05/2005] [Accepted: 08/15/2005] [Indexed: 12/28/2022]
Abstract
Estrogen-mediated neuroprotection is well established; however, no single mechanism of action for this effect has yet been established. As glial cells are integral for both the intact and injured nervous system, we hypothesized that estrogen-mediated neuroprotection may partly be attributed to attenuation of glial cell apoptosis, allowing them to protect neurons following injury. To assess the protective effects of estrogen on glia, C6 rat glioma cells were treated for 24 h with 500 microM glutamate. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and apoptosis was confirmed by cell morphology and DNA fragmentation. Pretreatment with 10 nM 17beta-estradiol (estrogen) increased cell viability and attenuated apoptosis. Treatment with the stereoisomer 17alpha-estradiol, or estrogen plus estrogen receptor antagonist ICI 182,780, was significantly less effective, indicating that cytoprotection was receptor-mediated. Estrogen treatment upregulated expression of estrogen receptor alpha. Cell impermeable bovine serum albumin-conjugated estrogen was also protective, indicating activation of estrogen receptors on the cell membrane. Intracellular free [Ca2+] was increased after glutamate treatment. This increase was attenuated in cells pretreated with estrogen. Glutamate increased the activity of pro-apoptotic proteases, such as calpain and caspase-3, and these protease activities were significantly attenuated by estrogen. The mechanism by which estrogen decreased intracellular Ca2+ was examined by assaying cell viability after using inhibitors that either blocked extracellular Ca2+ influx or prevented the release of intracellular Ca2+ stores. While several inhibitors increased cell viability in glutamate-treated cells, none were as protective as estrogen, and estrogen co-treatment significantly increased cell viability. These findings indicate that estrogen-mediated cytoprotection may be related to effects on Ca2+ entry but that these effects are not limited to any one of these Ca2+ entry points alone.
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Affiliation(s)
- E A Sribnick
- Department of Neurology, Medical University of South Carolina, 96 Johnathan Lucas Street, Charleston, SC 29425, USA
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Korkmaz F, Severcan F. Effect of progesterone on DPPC membrane: Evidence for lateral phase separation and inverse action in lipid dynamics. Arch Biochem Biophys 2005; 440:141-7. [PMID: 16054109 DOI: 10.1016/j.abb.2005.06.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 06/03/2005] [Accepted: 06/06/2005] [Indexed: 11/21/2022]
Abstract
Interactions of progesterone with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes were investigated as a function of temperature and progesterone concentration by using three non-invasive techniques namely Fourier transform infrared spectroscopy, turbidity at 440 nm, and differential scanning calorimetry. The results reveal that progesterone changes the physical properties of DPPC bilayers by decreasing the main phase-transition temperature, abolishing the pre-transition, broadening the phase-transition profile, disordering the system both in gel and liquid crystalline phase, increasing the dynamics at low concentrations whereas stabilizing the membrane at high concentrations, and inducing phase separation. Progesterone does not change the hydration of the CO groups, while it strengthens the hydrogen bonding between the PO2- groups of lipids and the water molecules around.
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Affiliation(s)
- Filiz Korkmaz
- Materials Science Engineering, Atilim University, Ankara 06836, Turkey
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Schlattjan JH, Biggemann F, Greven J. Gender differences in renal tubular taurocholate transport. Naunyn Schmiedebergs Arch Pharmacol 2005; 371:449-56. [PMID: 16041594 DOI: 10.1007/s00210-005-1081-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 06/30/2005] [Indexed: 11/26/2022]
Abstract
The bile acids filtered through the glomeruli nearly completely escape urinary excretion due to an efficient tubular reabsorption process. Reabsorption is mediated by the sodium-dependent bile acid transporter ASBT, which is localized in the brush border membranes of proximal tubular cells. The purpose of the present study was to assess whether tubular taurocholate transport is regulated by sex hormones. Clearance studies and studies on proximal tubular cells freshly isolated from rat kidneys were performed. The studies with the isolated proximal tubular cells revealed a cell to bath 3H-taurocholate accumulation ratio of 5.63+/-0.28 in male and of 3.67+/-0.43 in female rats (p<0.01). This difference in cellular taurocholate uptake was corroborated by the clearance studies, which showed a 3H-taurocholate clearance of 133.9+/-28.1 in male rats and of 262.0+/-45.4 microl/min x 100 g b.w. in female rats (p<0.05). Testosterone treatment of female rats did not significantly alter the cell to bath 3H-taurocholate accumulation ratio. However, the cellular taurocholate accumulation significantly decreased, by 61.6+/-10.1%, following ethinylestradiol treatment of male rats. Ovariectomy, chemical castration of female rats with buserelin or treatment of female rats with the estrogen receptor antagonist ICI 182780 did not affect taurocholate uptake, but treatment of ovariectomized rats with ethinylestradiol decreased the taurocholate accumulation ratio by 53.7+/-15.8%. By determination of serum bile acids the possibility was excluded that this change was an indirect effect of cholestasis induced by ethinylestradiol. This study demonstrates gender differences in the renal handling of taurocholate in rats that may be related to an inhibitory effect of estrogens on taurocholate transport in proximal tubular cells. Since the ASBT protein content of the proximal tubular cells was found not to be different between male and female rats, a nongenomic mechanism may underly this estrogen effect.
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Dykens JA, Carroll AK, Wiley S, Covey DF, Cai ZY, Zhao L, Wen R. Photoreceptor preservation in the S334ter model of retinitis pigmentosa by a novel estradiol analog. Biochem Pharmacol 2005; 68:1971-84. [PMID: 15476668 DOI: 10.1016/j.bcp.2004.06.042] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Accepted: 06/15/2004] [Indexed: 11/29/2022]
Abstract
The cytoprotective activity of MITO-4565, a novel, non-hormonal, estradiol derivative, was evaluated in the S334ter transgenic model of retinitis pigmentosa (RP). Progressive blindness in RP is due to apoptotic death of the photoreceptors, a process mimicked by the animal models [Portera-Cailliau C, Sung C-H, Nathans J, Adler R. Apoptotic photoreceptor cell death in mouse models of retinitis pigmentosa. Proc Natl Acad Sci USA 1994;91:974-8]. On postnatal day 9, 10 transgenic S334ter rats received a single intraocular injection of MITO-4565 in the left eye, and vehicle in the right eye. By postnatal day 20, the thickness of the outer nuclear layer (ONL) in the superior retina of the untreated eyes was 5.76 +/- 1.12 microm (N = 10), versus 10.72 +/- 1.52 microm (N = 10) for eyes treated with MITO-4565 (P < 0.0001, ANOVA F = 1671). Comparable cytoprotection was also observed for the inferior retina. Cytoprotection by MITO-4565 was also observed in primary cultures of rat retinal ganglion cells against NMDA excitotoxicity. Data from studies of hexose monophosphate shunt flux, mitochondrial stability, and in vitro lipid peroxidation, are in accord with previous reports [Green PS, Gridley KE, Simpkins JW. Nuclear estrogen receptor independent neuroprotection by estratrienes: a novel interaction with glutathione. Neuroscience 1997;84:7-10]; a likely mechanism of action entails moderation of membrane lipid peroxidation in a redox couple with glutathione. Such preservation of membrane integrity is particularly crucial to mitochondria, where collapse of membrane potential precipitates cell death, and where GSH is maintained at mM concentrations. Indeed, exposure to MITO-4565, but not a methoxy substituted negative control, allowed mitochondria to retain membrane potential (DeltaPsi(m)) under conditions of Ca(2+) overload that would normally induce complete mitochondrial failure. Mitochondrial interventions offer a novel therapeutic approach for RP, and other degenerative diseases of the retina.
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Affiliation(s)
- James A Dykens
- MitoKor Inc., 11494 Sorrento Valley Road, San Diego, CA 92121, USA.
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Claassen H, Schünke M, Kurz B. Estradiol protects cultured articular chondrocytes from oxygen-radical-induced damage. Cell Tissue Res 2005; 319:439-45. [PMID: 15668798 DOI: 10.1007/s00441-004-1029-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Accepted: 10/20/2004] [Indexed: 10/25/2022]
Abstract
Osteoarthritis (OA) is aggravated in menopausal women possibly because of changed serum estrogen levels. Estradiol has been postulated to affect oxidative stress induced by reactive oxygen species (ROS) in articular chondrocytes. We generated ROS in cultured bovine articular chondrocytes by incubating them with combined Fe2SO4, vitamin C, and hydrogen peroxide. The release of thiobarbituric-acid-reactive substances (TBARS, lipid peroxidation) and lactate dehydrogenase (LDH, membrane damage) was measured photometrically. Various estradiol doses and vitamin E, serving as control with an established anti-oxidative capacity, were applied either upon each exchange of medium and during radical production (strategy 1) or only during radical production (strategy 2). In chondrocytes incubated according to strategy 1, the production of TBARS and LDH release were significantly suppressed by 10(-10)-10(-4) M estradiol or by vitamin E. Under strategy 2, the production of TBARS was significantly suppressed at estradiol concentrations higher than 10(-6) M, whereas LDH release was inhibited at concentrations of 10(-6)-10(-4) M. Vitamin E showed no significant effects. As repeated application of estradiol and vitamin E produced the best results, estradiol, like vitamin E, was speculated to accumulate in the plasma membrane and to decrease membrane fluidity resulting in protection against lipid peroxidation (non-genomic effect). Thus, in contrast to the neuroprotective effect of 17beta-estradiol in supraphysiological doses reported recently, the anti-oxidative potential of estradiol appears to protect articular chondrocytes from ROS-induced damage when the hormone is given repeatedly in a physiological range. Decreased estradiol levels may therefore contribute to menopausal OA in the long term.
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Affiliation(s)
- Horst Claassen
- Institut für Anatomie und Zellbiologie der Martin-Luther-Universität Halle-Wittenberg, Grosse Steinstrasse 52, 06097, Halle, Germany.
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