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Kumar RG, DiSanto D, Awan N, Vaughan LE, Levochkina MS, Weppner JL, Wright DW, Berga SL, Conley YP, Brooks MM, Wagner AK. Temporal Acute Serum Estradiol and Tumor Necrosis Factor-α Associations and Risk of Death after Severe Traumatic Brain Injury. J Neurotrauma 2020; 37:2198-2210. [PMID: 32375598 DOI: 10.1089/neu.2019.6577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Severe traumatic brain injury (TBI) activates a robust systemic response that involves inflammatory and other factors, including estradiol (E2), associated with increased deaths. Tumor necrosis factor-alpha (TNFα) is a significant mediator of systemic shock, and it is an extra-gonadal transcription factor for E2 production. The study objectives were to test the hypotheses: (1) a positive feedback relationship exists between acute serum TNFα and E2; and (2) acute concentrations of E2 and TNFα are prognostic indicators of death after severe TBI. This prospective cohort study included N = 157 adults with severe TBI. Serum samples were collected for the first five days post-injury. The TNFα and E2 levels were averaged into two time epochs: first 72 h (T1) and second 72 h post-injury (T2). A cross-lag panel analysis conducted between T1 and T2 TNFα and E2 levels showed significant cross-lag effects: T1 TNFα and T1 E2 were related to T2 E2 and T2 TNFα, respectively. Cox proportional hazards multi variable regression models determined that increases in T1 E2 (hazard ratio [HR] = 1.79, 95% confidence interval [CI]: 1.15, 2.81), but not T2 E2 (HR = 0.91, 95% CI: 0.56, 1.47), were associated with increased risk of death. Increased T2 TNFα (HR = 2.47, 95% CI: 1.35, 4.53), and T1 TNFα (HR = 1.47, 95% CI: 0.99, 2.19), to a lesser degree, were associated with increased risk of death. Relationships of death with T2 TNFα and T1 E2 were mediated partially by cardiovascular, hepatic, and renal dysfunction. Both E2 and TNFα are systemic, reciprocally related biomarkers that may be indicative of systemic compromise and increased risk of death after severe TBI.
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Affiliation(s)
- Raj G Kumar
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Dominic DiSanto
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nabil Awan
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Leah E Vaughan
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Marina S Levochkina
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Justin L Weppner
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - David W Wright
- Department of Emergency Medicine, Emory University, Atlanta, Georgia
| | - Sarah L Berga
- Department of Reproductive Endocrinology, University of Utah, Salt Lake City, Utah
| | - Yvette P Conley
- School of Nursing, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Maria M Brooks
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Amy K Wagner
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania
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Wagner AK, Kumar RG. TBI Rehabilomics Research: Conceptualizing a humoral triad for designing effective rehabilitation interventions. Neuropharmacology 2018; 145:133-144. [PMID: 30222984 DOI: 10.1016/j.neuropharm.2018.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/14/2018] [Accepted: 09/10/2018] [Indexed: 12/11/2022]
Abstract
Most areas of medicine use biomarkers in some capacity to aid in understanding how personal biology informs clinical care. This article draws upon the Rehabilomics research model as a translational framework for programs of precision rehabilitation and intervention research focused on linking personal biology to treatment response using biopsychosocial constructs that broadly represent function and that can be applied to many clinical populations with disability. The summary applies the Rehabilomics research framework to the population with traumatic brain injury (TBI) and emphasizes a broad vision for biomarker inclusion, beyond typical brain-derived biomarkers, to capture and/or reflect important neurological and non-neurological pathology associated with TBI as a chronic condition. Humoral signaling molecules are explored as important signaling and regulatory drivers of these chronic conditions and their impact on function. Importantly, secondary injury cascades involved in the humoral triad are influenced by the systemic response to TBI and the development of non-neurological organ dysfunction (NNOD). Biomarkers have been successfully leveraged in other medical fields to inform pre-randomization patient selection for clinical trials, however, this practice largely has not been utilized in TBI research. As such, the applicability of the Rehabilomics research model to contemporary clinical trials and comparative effectiveness research designs for neurological and rehabilitation populations is emphasized. Potential points of intervention to modify inflammation, hormonal, or neurotrophic support through rehabilitation interventions are discussed. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".
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Affiliation(s)
- A K Wagner
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, USA; Safar Center for Resuscitation Research, University of Pittsburgh, USA; Department of Neuroscience, University of Pittsburgh, USA; Center for Neuroscience, University of Pittsburgh, USA.
| | - R G Kumar
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, USA; Safar Center for Resuscitation Research, University of Pittsburgh, USA; Department of Epidemiology, University of Pittsburgh, USA
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Ranganathan P, Kumar RG, Oh BM, Rakholia MV, Berga SL, Wagner AK. Estradiol to Androstenedione Ratios Moderate the Relationship between Neurological Injury Severity and Mortality Risk after Severe Traumatic Brain Injury. J Neurotrauma 2018; 36:538-547. [PMID: 30014751 DOI: 10.1089/neu.2018.5677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Early declines in gonadotropin production, despite elevated serum estradiol, among some individuals with severe traumatic brain injury (TBI) suggests amplified systemic aromatization occurs post-injury. Our previous work identifies estradiol (E2) as a potent mortality marker. Androstenedione (A), a metabolic precursor to E2, estrone (E1), and testosterone (T), is a steroid hormone substrate for aromatization that has not been explored previously as a biomarker in TBI. Here, we evaluated serum A, E1, T, and E2 values for 82 subjects with severe TBI. Daily hormone values were calculated, and E2:A and E1:T ratios were generated and then averaged for days 0-3 post-injury. After data inspection, mean E2:A values were categorized as above (high aromatization) and below (low aromatization) the 50th percentile for 30-day mortality assessment using Kaplan-Meier survival analysis and a multivariable Cox proportional hazard model adjusting for age, and Glasgow Coma Scale (GCS) to predict 30-day mortality status. Daily serum T, E1, and E2 were graphed by E2:A category. Serum E1 and E2 significantly differed over time (p < 0.05); the high aromatization group had elevated levels and a significantly lower probability of survival within the first 30 days (p = 0.0274). Multivariable Cox regression showed a significant E2:A*GCS interaction (p = 0.0129), wherein GCS predicted mortality only among those in the low aromatization group. E2:A may be a useful mortality biomarker representing enhanced aromatization after TBI. E2:A ratios may represent non-neurological organ dysfunction after TBI and may be useful in defining injury subgroups in which GCS has variable capacity to serve as an accurate early prognostic marker.
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Affiliation(s)
- Prerna Ranganathan
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh , Pittsburgh, Pennslvania
| | - Raj G Kumar
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh , Pittsburgh, Pennslvania
| | - Byung-Mo Oh
- 2 Department of Rehabilitation Medicine, Seoul National University Hospital , Seoul, Korea
| | - Milap V Rakholia
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh , Pittsburgh, Pennslvania
| | - Sarah L Berga
- 3 Department of Obstetrics and Gynecology, University of Utah Medical Center , Salt Lake City, Utah
| | - Amy K Wagner
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh , Pittsburgh, Pennslvania.,4 Department of Neuroscience, University of Pittsburgh , Pittsburgh, Pennsylvania.,5 Center for Neuroscience, University of Pittsburgh , Pittsburgh, Pennsylvania.,6 Clinical and Translational Science Institute, University of Pittsburgh , Pittsburgh, Pennsylvania
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Rakholia MV, Kumar RG, Oh BM, Ranganathan PR, Berga SL, Kochanek PM, Wagner AK. Systemic Estrone Production and Injury-Induced Sex Hormone Steroidogenesis after Severe Traumatic Brain Injury: A Prognostic Indicator of Traumatic Brain Injury-Related Mortality. J Neurotrauma 2018; 36:1156-1167. [PMID: 29947289 DOI: 10.1089/neu.2018.5782] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Extensive pre-clinical studies suggest that sex steroids are neuroprotective in experimental traumatic brain injury (TBI). However, clinical trials involving sex hormone administration have not shown beneficial results, and our observational cohort studies show systemic estradiol (E2) production to be associated with adverse outcomes. Systemic E2 is produced via aromatization of testosterone (T) or reduction of estrone (E1). E1, also produced via aromatization of androstenedione (Andro) and is a marker of T-independent E2 production. We hypothesized that E1 would be (1) associated with TBI-related mortality, (2) the primary intermediate for E2 production, and (3) associated with adipose tissue-specific aromatase transcription. We assessed 100 subjects with severe TBI and 8 healthy controls. Serum levels were measured on days 0-3 post-TBI for key steroidogenic precursors (progesterone), aromatase pathway intermediates (E1, E2, T, Andro), and the adipose tissue-specific aromatase transcription factors cortisol, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). E1 was elevated after TBI versus controls. High E1 was associated with higher progesterone, cortisol, and IL-6 (p < 0.05). Multivariable logistic regression demonstrated that those in the highest E1 tertile had increased odds for mortality (adjusted OR = 5.656, 95% CI = 1.102-29.045, p = 0.038). Structural equation models show that early serum E2 production is largely T independent, occurring predominantly through E1 metabolism. Acute serum E1 functions as a mortality marker for TBI through aromatase-dependent E1 production and T-independent E2 production. Further work should evaluate risk factors for high E2 production and how systemic E2 and its key intermediate E1 contribute to the extracerebral consequences of severe TBI.
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Affiliation(s)
- Milap V Rakholia
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh Pennsylvania
| | - Raj G Kumar
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh Pennsylvania
| | - Byung-Mo Oh
- 2 Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Prerna R Ranganathan
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh Pennsylvania
| | - Sarah L Berga
- 3 Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Patrick M Kochanek
- 4 Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh Pennsylvania.,5 Department of Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh Pennsylvania
| | - Amy K Wagner
- 1 Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh Pennsylvania.,5 Department of Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh Pennsylvania.,6 Department of Neuroscience, University of Pittsburgh, Pittsburgh Pennsylvania.,7 Department of Center for Neuroscience, University of Pittsburgh, Pittsburgh Pennsylvania
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Li J, Li WQ, Yao Y. Vasorelaxation Effect of Estrone Derivate EA204 in Rabbit Aorta. SCIENTIFICA 2016; 2016:7405797. [PMID: 27190689 PMCID: PMC4848441 DOI: 10.1155/2016/7405797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/13/2016] [Accepted: 03/27/2016] [Indexed: 06/05/2023]
Abstract
Estrogen and its derivatives exert vascular protective effects, but the underlying mechanisms remain to be studied fully. Objective. To investigate the vasorelaxation effect and related mechanisms of an estrone derivate EA204[3-(2-piperidin-1-yl)-ethoxy-estra-1, 3, 5 (10)-trien-17-one] on isolated arterial preparation from rabbit thoracic aorta. Methods. Aortic rings from rabbit thoracic aorta were prepared and held in small organ bath filled with Krebs solution; tension change was recorded by a multichannel physiological signal collection and handling system. Results. EA204 (10(-5) to 10(-3) M) induced a concentration-dependent relaxation of aortic rings with endothelium and without endothelium. In denuded arterial preparations, EA204 had a potent relaxing effect on isolated arterial preparations contracted with phenylephrine, norepinephrine, and high-K(+) solution or BaCl2. Mechanism study indicates that EA204 relaxes aortic rings by inhibiting Ca(2+) channels (both receptor-operating Ca(2+) channels and the voltage-dependent Ca(2+) channels were involved) to decrease extracellular Ca(2+) influx and intracellular Ca(2+) release. EA204 is different from verapamil, which is a noncompetitive inhibitor of Ca(2+) channels. In addition, K(+) channels opening may contribute to this vasorelaxation effect. Conclusion. EA204 had a potent endothelium-independent relaxing effect on isolated arterial preparation by inhibiting Ca(2+) channels and opening K(+) channels. The results suggest that EA204 is a potential compound for treatment of cardiovascular diseases in postmenopausal women.
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Affiliation(s)
- Juan Li
- School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China; Ningxia Engineering and Technology Research Center for Modernization of Hui Medicine, Yinchuan 750004, China
| | - Wei-Qi Li
- National Resource Center of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; China National Center for Biotechnology Development, Beijing 100039, China
| | - Yao Yao
- School of Basic Medical Science, Ningxia Medical University, Yinchuan 750004, China; Research Center of Medical Science and Technology, Ningxia Medical University, Yinchuan 750004, China
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6
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Tang Y, Jacobi A, Vater C, Zou L, Zou X, Stiehler M. Icariin promotes angiogenic differentiation and prevents oxidative stress-induced autophagy in endothelial progenitor cells. Stem Cells 2015; 33:1863-77. [PMID: 25787271 DOI: 10.1002/stem.2005] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 01/18/2015] [Accepted: 02/13/2015] [Indexed: 12/19/2022]
Abstract
Reduced tissue levels of endothelial progenitor cells (EPCs) and functional impairment of endothelium are frequently observed in patients with diabetes and cardiovascular disease. The vascular endothelium is specifically sensitive to oxidative stress, and this is one of the mechanisms that causes widespread endothelial dysfunction in most cardiovascular diseases and disorders. Hence attention has increasingly been paid to enhance mobilization and differentiation of EPCs for therapeutic purposes. The aim of this study was to investigate whether Icariin, a natural bioactive component known from traditional Chinese Medicine, can induce angiogenic differentiation and inhibit oxidative stress-induced cell dysfunction in bone marrow-derived EPCs (BM-EPCs), and, if so, through what mechanisms. We observed that treatment of BM-EPCs with Icariin significantly promoted cell migration and capillary tube formation, substantially abrogated hydrogen peroxide (H2 O2 )-induced apoptotic and autophagic programmed cell death that was linked to the reduced intracellular reactive oxygen species levels and restored mitochondrial membrane potential. Icariin downregulated endothelial nitric oxide synthase 3, as well as nicotinamide-adenine dinucleotide phosphate-oxidase expression upon H2 O2 induction. These antiapoptotic and antiautophagic effects of Icariin are possibly mediated by restoring the loss of mammalian target of rapamycin /p70S6K/4EBP1 phosphorylation as well as attenuation of ATF2 and ERK1/2 protein levels after H2 O2 treatment. In summary, favorable modulation of the angiogenesis and redox states in BM-EPCs make Icariin a promising proangiogenic agent both enhancing vasculogenesis and protecting against endothelial dysfunction.
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Affiliation(s)
- Yubo Tang
- Department of Orthopaedics and Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Centre for Orthopaedics and Trauma Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, Dresden, Germany.,Department of Pharmacy, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Angela Jacobi
- Department of Orthopaedics and Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Centre for Orthopaedics and Trauma Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, Dresden, Germany
| | - Corina Vater
- Department of Orthopaedics and Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Centre for Orthopaedics and Trauma Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, Dresden, Germany
| | - Lijin Zou
- Department of Burn surgery and Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xuenong Zou
- Department of Spinal Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Maik Stiehler
- Department of Orthopaedics and Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Centre for Orthopaedics and Trauma Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, Dresden, Germany
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7
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Tang Y, Vater C, Jacobi A, Liebers C, Zou X, Stiehler M. Salidroside exerts angiogenic and cytoprotective effects on human bone marrow-derived endothelial progenitor cells via Akt/mTOR/p70S6K and MAPK signalling pathways. Br J Pharmacol 2014; 171:2440-56. [PMID: 24471788 DOI: 10.1111/bph.12611] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 01/12/2014] [Accepted: 01/23/2014] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE With the increase of age, increased susceptibility to apoptosis and senescence may contribute to proliferative and functional impairment of endothelial progenitor cells (EPCs). The aim of this study was to investigate whether salidroside (SAL) can induce angiogenic differentiation and inhibit oxidative stress-induced apoptosis in bone marrow-derived EPCs (BM-EPCs), and if so, through what mechanism. EXPERIMENTAL APPROACH BM-EPCs were isolated and treated with different concentrations of SAL for up to 4 days. Cell proliferation, migration and tube formation ability were detected by DNA content quantification, transwell assay and Matrigel-based angiogenesis assay. Gene and protein expression were assessed by qRT-PCR and Western blot respectively. KEY RESULTS Treatment with SAL promoted cellular proliferation and angiogenic differentiation of BM-EPCs, and increased VEGF and NO secretion, which in turn mediated the enhanced angiogenic differentiation of BM-EPCs. Furthermore, SAL significantly attenuated hydrogen peroxide (H₂O₂)-induced cell apoptosis, reduced the intracellular level of reactive oxygen species and restored the mitochondrial membrane potential of BM-EPCs. Moreover, SAL stimulated the phosphorylation of Akt, mammalian target of rapamycin and p70 S6 kinase, as well as ERK1/2, which is associated with cell migration and capillary tube formation. Additionally, SAL reversed the phosphorylation of JNK and p38 MAPK induced by H₂O₂ and suppressed the changes in the Bax/Bcl-xL ratio observed after stimulation with H₂O₂. CONCLUSIONS AND IMPLICATIONS These findings identify novel mechanisms that regulate EPC function and suggest that SAL has therapeutic potential as a new agent to enhance vasculogenesis as well as protect against oxidative endothelial injury.
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Affiliation(s)
- Yubo Tang
- Centre for Translational Bone, Joint and Soft Tissue Research, Medical Faculty and University Centre for Orthopaedics and Trauma Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, Dresden, Germany; Department of Pharmacy, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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do Nascimento GRA, Barros YVR, Wells AK, Khalil RA. Research into Specific Modulators of Vascular Sex Hormone Receptors in the Management of Postmenopausal Cardiovascular Disease. Curr Hypertens Rev 2009; 5:283-306. [PMID: 20694192 DOI: 10.2174/157340209789587717] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cardiovascular disease (CVD) is more common in men and postmenopausal women than premenopausal women, suggesting vascular benefits of female sex hormones. Studies on the vasculature have identified estrogen receptors ERα, ERβ and a novel estrogen binding membrane protein GPR30, that mediate genomic and/or non-genomic effects. Estrogen promotes endothelium-dependent relaxation by inducing the production/activity of nitric oxide, prostacyclin, and hyperpolarizing factor, and inhibits the mechanisms of vascular smooth muscle contraction including [Ca(2+)](i), protein kinase C, Rho kinase and mitogen-activated protein kinase. Additional effects of estrogen on the cytoskeleton, matrix metalloproteinases and inflammatory factors contribute to vascular remodeling. However, the experimental evidence did not translate into vascular benefits of menopausal hormone therapy (MHT), and the HERS, HERS-II and WHI clinical trials demonstrated adverse cardiovascular events. The discrepancy has been partly related to delayed MHT and potential changes in the vascular ER amount, integrity, affinity, and downstream signaling pathways due to the subjects' age and preexisting CVD. The adverse vascular effects of MHT also highlighted the need of specific modulators of vascular sex hormone receptors. The effectiveness of MHT can be improved by delineating the differences in phramcokinetics and pharmacodynamics of natural, synthetic, and conjugated equine estrogens. Estriol, "hormone bioidenticals" and phytoestrogens are potential estradiol substitutes. The benefits of low dose MHT, and transdermal or vaginal estrogens over oral preparations are being evaluated. Specific ER modulators (SERMs) and ER agonists are being developed to maximize the effects on vascular ERs. Also, the effects of estrogen are being examined in the context of the whole body hormonal environment and the levels of progesterone and androgens. Thus, the experimental vascular benefits of estrogen can be translated to the outcome of MHT in postmenopausal CVD, as more specific modulators of sex hormone receptors become available and are used at the right dose, route of administration and timing, depending on the subject's age and preexisting cardiovascular condition.
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Smith J, Lindsay M, Rahimian R, Anderson L. The influence of estrogen and progesterone on parasympathetic vasodilatation in the rat submandibular gland. Auton Neurosci 2009; 146:87-94. [PMID: 19162561 DOI: 10.1016/j.autneu.2008.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 12/15/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
Abstract
Previous studies suggest that NO- and PGI(2)-independent pathways play a greater role in parasympathetic vasodilatation in the submandibular glands (SMG) of female than of male rats. Thus, the purpose of this study was to determine whether estrogen and progesterone influence the relative contributions of NO and PGI(2) to parasympathetic vasodilatation in the SMG. Vascular responses to chorda-lingual nerve stimulation were examined in sham-operated (SHAM) and ovariectomized (OVX) female rats and in OVX rats treated with either 17beta-estradiol alone or a combination of 17beta-estradiol and progesterone. Compared with SHAM animals, increases in vascular conductance in OVX rats were reduced at 1, 2 and 5 Hz (p<0.05). Blood flow responses in OVX+17beta-estradiol and OVX+17beta-estradiol+progesterone rats were indistinguishable from those observed in SHAM animals. Indomethacin had no effect on vasodilatation in SHAM and OVX+17beta-estradiol rats, but increased vascular responses in OVX animals (p<0.02). The addition of L-NAME resulted in a significant reduction in vasodilatation at all frequencies. In OVX rats treated with both estrogen and progesterone, indomethacin caused a reduction in vasodilatation and L-NAME further diminished the remaining responses. Under all conditions, vasodilatation was due largely, if not exclusively, to direct parasympathetic rather than antidromic sensory nerve activation. Finally, both neuronally-derived and endothelium-derived NO appeared to be responsible for the NO-dependent vasodilatation, but endothelium-derived NO became increasingly important as the frequency of stimulation increased. We conclude that estrogen and progesterone influence parasympathetic vasodilatation through combined effects on NO-, PGI(2)- and non-NO/PGI(2)-mediated pathways.
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Affiliation(s)
- Joshua Smith
- Dental Program, University of the Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA 94115, USA
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Parker BA, Smithmyer SL, Proctor DN. Hormone therapy is associated with preserved smooth muscle structure and dilation in the arterial vasculature of the leg in older women. Maturitas 2008; 59:46-54. [PMID: 18068915 DOI: 10.1016/j.maturitas.2007.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 10/23/2007] [Accepted: 10/26/2007] [Indexed: 12/31/2022]
Abstract
Long-term hormone therapy (HT) is associated with reduced intima-medial thickness (IMT), an established risk factor for atherosclerotic disease, in the femoral artery of healthy older women relative to age-matched non-hormone users. However, the influence of continuous, long-term HT on the relation between age, IMT, and smooth muscle dilation has not been investigated in the popliteal artery, an artery prone to stiffening and calcification. In the present study, popliteal artery IMT and smooth muscle dilation (the increase in diameter to sublingual nitroglycerin, NTG) were assessed with Doppler ultrasound in young (Y: n=16; age 23+/-1 [mean+/-S.E.M.]), older non-HT (O non-HT: n=14; age 69+/-1), and older HT (O HT: n=8; age 67+/-1) healthy women. The approximately 0.5 mm increase in resting diameter observed in older non-HT women relative to young women was absent in older HT women, as was the age-related increase in IMT (Y: 0.52+/-0.02 mm; O non-HT: 0.63+/-0.02 mm; O HT: 0.56+/-0.02 mm; p<0.05 for age and hormone comparisons). NTG dilation (percent change above rest) was similarly attenuated in older non-HT women (Y: 8.6+/-1%; O non-HT: 3.0+/-0.7%; O HT: 7.4+/-1.7%; p<0.05 for age and hormone comparisons), and NTG dilation was inversely related to IMT (p<0.01). Collectively, these results suggest that long-term, continuous HT may alleviate the detrimental effects of aging on both structural changes and smooth muscle dilation of the popliteal artery in healthy women.
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Affiliation(s)
- Beth A Parker
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
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Bishop GD, Brown MD. Cutaneous postural vasoconstriction is modified by exogenous but not endogenous female hormones in young women. Clin Auton Res 2007; 17:85-92. [PMID: 17264978 DOI: 10.1007/s10286-006-0393-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 01/02/2007] [Indexed: 11/26/2022]
Abstract
Previously reported attenuation of skin postural vasoconstriction in women during the luteal menstrual cycle phase may be due to a progesterone-mediated decrease in myogenic or veno-arteriolar (VAR) mechanisms. Skin perfusion was measured in the shin and foot dorsum by Laser Doppler Fluxometry during leg dependency that increased vascular transmural pressure below (myogenic constriction only) and above (myogenic and VAR) the 25 mmHg threshold for activation of the VAR, and during venous distension to activate the VAR alone (cuff inflation to 50 mmHg). In six young women with normal menstrual cycles, vasoconstrictor responses to all interventions did not differ between days 7-13 (follicular) and 18-23 (luteal) of the normal menstrual cycle when progesterone levels were low and at their peak respectively. In eight women taking combined oral contraceptives (OC) and tested during pill consumption days, reductions in foot skin perfusion were smaller (P = 0.05) than in the luteal phase of the normal cycle for leg dependency below (-36.9 +/- 5.2% OC vs. -52.5 +/- 7.8% luteal, mean +/- S.E.M.) and above (-43.7 +/- 3.4% OC vs. -55.1 +/- 4.8% luteal) the VAR threshold, and for venous distension (-53.1 +/- 2.6% OC vs. 66.4 +/- 5.5% luteal). In women with normal menstrual cycles, impaired postural vasoconstriction may be confined to those who experience pre-menstrual symptoms rather than a direct effect of endogenous hormones. Reduced vasoconstriction in the dependent foot during OC use is consistent with the known vasodilator action of exogenous hormones and its long-term effects.
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Affiliation(s)
- Gemma D Bishop
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK.
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