1
|
Koukalova L, Chmelova M, Amlerova Z, Vargova L. Out of the core: the impact of focal ischemia in regions beyond the penumbra. Front Cell Neurosci 2024; 18:1336886. [PMID: 38504666 PMCID: PMC10948541 DOI: 10.3389/fncel.2024.1336886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 02/08/2024] [Indexed: 03/21/2024] Open
Abstract
The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.
Collapse
Affiliation(s)
- Ludmila Koukalova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Martina Chmelova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| | - Zuzana Amlerova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Lydia Vargova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
2
|
Smith C, Contreras-Garza J, Cunningham RL, Wong JM, Vann PH, Metzger D, Kasanga E, Oppong-Gyebi A, Sumien N, Schreihofer DA. Chronic Testosterone Deprivation Sensitizes the Middle-Aged Rat Brain to Damaging Effects of Testosterone Replacement. Neuroendocrinology 2020; 110:914-928. [PMID: 31671430 DOI: 10.1159/000504445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/30/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION An increasing number of middle-aged men are being screened for low testosterone levels and the number of prescriptions for various forms of testosterone replacement therapy (TRT) has increased dramatically over the last 10 years. However, the safety of TRT has come into question with some studies suggesting increased morbidity and mortality. OBJECTIVE Because the benefits of estrogen replacement in postmenopausal women and ovariectomized rodents are lost if there is an extended delay between estrogen loss and replacement, we hypothesized that TRT may also be sensitive to delayed replacement. METHODS We compared the effects of testosterone replacement after short-term (2 weeks) and long-term testosterone deprivation (LTTD; 10 weeks) in middle-aged male rats on cerebral ischemia, oxidative stress, and cognitive function. We hypothesized that LTTD would increase oxidative stress levels and abrogate the beneficial effects of TRT. RESULTS Hypogonadism itself and TRT after short-term castration did not affect stroke outcome compared to intact rats. However, after long-term hypogonadism in middle-aged male Fischer 344 rats, TRT exacerbated the detrimental behavioral effects of experimental focal cerebral ischemia, whereas this detrimental effect was prevented by administration of the free-radical scavenger tempol, suggesting that TRT exacerbates oxidative stress. In contrast, TRT improved cognitive performance in non-stroked rats regardless of the length of hypogonadism. In the Morris water maze, peripheral oxidative stress was highly associated with decreased cognitive ability. CONCLUSIONS Taken together, these data suggest that TRT after long-term hypogonadism can exacerbate functional recovery after focal cerebral ischemia, but in the absence of injury can enhance cognition. Both of these effects are modulated by oxidative stress levels.
Collapse
Affiliation(s)
- Charity Smith
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Jo Contreras-Garza
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Rebecca L Cunningham
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Jessica M Wong
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Philip H Vann
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Daniel Metzger
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Ella Kasanga
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Anthony Oppong-Gyebi
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Nathalie Sumien
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Derek A Schreihofer
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA,
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA,
| |
Collapse
|
3
|
Sohrabji F, Okoreeh A, Panta A. Sex hormones and stroke: Beyond estrogens. Horm Behav 2019; 111:87-95. [PMID: 30713101 PMCID: PMC6527470 DOI: 10.1016/j.yhbeh.2018.10.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/22/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022]
Abstract
Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.
Collapse
Affiliation(s)
- Farida Sohrabji
- Women's Health in Neuroscience Program, Neuroscience and Experimental Therapeutics, Texas A&M College of Medicine, Bryan, TX 77807, United States of America.
| | - Andre Okoreeh
- Women's Health in Neuroscience Program, Neuroscience and Experimental Therapeutics, Texas A&M College of Medicine, Bryan, TX 77807, United States of America
| | - Aditya Panta
- Women's Health in Neuroscience Program, Neuroscience and Experimental Therapeutics, Texas A&M College of Medicine, Bryan, TX 77807, United States of America
| |
Collapse
|
4
|
Wright JL, Chu HX, Kagan BJ, Ermine CM, Kauhausen JA, Parish CL, Sobey CG, Thompson LH. Local Injection of Endothelin-1 in the Early Neonatal Rat Brain Models Ischemic Damage Associated with Motor Impairment and Diffuse Loss in Brain Volume. Neuroscience 2018; 393:110-122. [PMID: 30300704 DOI: 10.1016/j.neuroscience.2018.09.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/23/2018] [Accepted: 09/28/2018] [Indexed: 11/16/2022]
Abstract
Cerebral palsy is an irreversible movement disorder resulting from cerebral damage sustained during prenatal or neonatal brain development. As survival outcomes for preterm injury improve, there is increasing need to model ischemic injury at earlier neonatal time-points to better understand the subsequent pathological consequences. Here we demonstrate a novel neonatal ischemic model using focal administration of the potent vasoconstrictor peptide, endothelin-1 (ET-1), in newborn rats. The functional and histopathological outcomes compare favourably to those reported following the widely used hypoxic ischemia (HI) model. These include a robust motor deficit sustained into adulthood and recapitulation of hallmark features of preterm human brain injury, including atrophy of subcortical white matter and periventricular fiber bundles. Compared to procedures involving carotid artery manipulation and periods of hypoxia, the ET-1 ischemia model represents a rapid and technically simplified model more amenable to larger cohorts and with the potential to direct the locus of ischemic damage to specific brain areas.
Collapse
Affiliation(s)
- Jordan L Wright
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia.
| | - Hannah X Chu
- Biomedicine Discovery Institute and Department of Pharmocology, Monash University, Melbourne, VIC, Australia
| | - Brett J Kagan
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Charlotte M Ermine
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Jessica A Kauhausen
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Clare L Parish
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Christopher G Sobey
- Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC, Australia
| | - Lachlan H Thompson
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia.
| |
Collapse
|
5
|
Meadows KL. Ischemic stroke and select adipose-derived and sex hormones: a review. Hormones (Athens) 2018; 17:167-182. [PMID: 29876798 DOI: 10.1007/s42000-018-0034-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/27/2018] [Indexed: 02/03/2023]
Abstract
Ischemic stroke is the fifth leading cause of death in the USA and is the leading cause of serious, long-term disability worldwide. The principle sex hormones (estrogen, progesterone, and testosterone), both endogenous and exogenous, have profound effects on various stroke outcomes and have become the focus of a number of studies evaluating risk factors and treatment options for ischemic stroke. In addition, the expression of other hormones that may influence stroke outcome, including select adipose-derived hormones (adiponectin, leptin, and ghrelin), can be regulated by sex hormones and are also the focus of several ischemic stroke studies. This review aims to summarize some of the preclinical and clinical studies investigating the principle sex hormones, as well as select adipose-derived hormones, as risk factors or potential treatments for ischemic stroke. In addition, the potential for relaxin, a lesser studied sex hormone, as a novel treatment option for ischemic stroke is explored.
Collapse
Affiliation(s)
- Kristy L Meadows
- Cummings School of Veterinary Medicine, Tufts University, 200 Westboro Rd., North Grafton, MA, 01536, USA.
| |
Collapse
|
6
|
Zhong YH, Dhawan J, Kovoor JA, Sullivan J, Zhang WX, Choi D, Biegon A. Aromatase and neuroinflammation in rat focal brain ischemia. J Steroid Biochem Mol Biol 2017; 174:225-233. [PMID: 28964927 DOI: 10.1016/j.jsbmb.2017.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 09/24/2017] [Accepted: 09/25/2017] [Indexed: 12/22/2022]
Abstract
Accumulating evidence suggests that expression of aromatase, the enzyme responsible for the conversion of androgens to estrogens, is transiently upregulated in rat stroke models. It was further suggested that increased aromatase expression is linked to neuroinflammation and that it is neuroprotective in females. Our goal was to investigate aromatase upregulation in male rats subjected to experimental stroke in relationship to neuroinflammation, infarct and response to treatment with different putative neuroprotective agents. Intact male rats were subjected to transient (90min) middle cerebral artery occlusion (MCAO) and administered selfotel (N-methyl-d-aspartic acid (NMDA) receptor competitive antagonist), TPEN (a zinc chelator), a combination of the two drugs or vehicle, injected immediately after reperfusion. Animals were killed 14days after MCAO and consecutive brain sections used to measure aromatase expression, cerebral infarct volume and neuroinflammation. Quantitative immunohistochemistry (IHC) demonstrated increased brain aromatase expression in the peri-infarct area relative to contralesional area, which was partially abrogated by neuroprotective agents. There was no correlation between aromatase expression in the peri-infarct zone and infarct volume, which was reduced by neuroprotective agents. Microglial activation, measured by quantitative autoradiography, was positively correlated with infarct and inversely correlated with aromatase expression in the peri-infarct zone. Our findings indicate that focal ischemia upregulates brain aromatase in the male rat brain at 14days post surgery, which is within the time frame documented in females. However, the lack of negative correlation between aromatase expression and infarct volume and lack of positive correlation between microgliosis and aromatase do not support a major role for aromatase as a mediator of neuroprotection or a causal relationship between microglial activation and increased aromatase expression in male focal ischemia.
Collapse
Affiliation(s)
- Yu H Zhong
- Department of Neurology, the First Affiliated Hospital of Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, Guangdong Province 510080, PR China; Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| | - Jasbeer Dhawan
- Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| | - Joel A Kovoor
- Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| | - John Sullivan
- Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| | - Wei X Zhang
- Department of Neurology, the First Affiliated Hospital of Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, Guangdong Province 510080, PR China.
| | - Dennis Choi
- Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| | - Anat Biegon
- Department of Neurology, Stony Brook University, 100 Nicolls Road, Stony Brook, NY 11794-2565, USA.
| |
Collapse
|
7
|
Wu Y, Hu L, Yang X, Wang X, Wan L, Hua X, Cheng J, Li Y. Intraluminal spindle-shaped-head suture induced occlusion of middle cerebral artery in the rats. Neurol Res 2017; 39:1028-1036. [PMID: 28936922 DOI: 10.1080/01616412.2017.1375661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE This study aimed to introduce a modified animal model of middle cerebral arterial occlusion (MCAO) through placement of intraluminal spindle-shaped head suture by comparing the traditional MCAO model. METHODS A total of 60 male Spraque-Dawley (SD) rats were divided into two groups and MCAO was induced using spindle-shaped head suture or round head suture. The mortality, infarct volume, neurological function, success rate of the surgery, and stability of modeling were examined to evaluate the effectiveness of this model. RESULTS Our results showed the success rate was 90.0% in spindle-shaped head group and 83.3% in round head group showing no significant difference; spindle-shaped head achieved a better establishment of MCAO model as shown in neurological examination. The infarct volume was 31.99 ± 5.44% in spindle-shaped head group and was significantly higher than in round head group (24.59 ± 7.17%; p < 0.05), and the coefficient of variation of infarct volume in spindle-shaped head group was lower than in round head group. CONCLUSION Our findings indicate that the modified suture induces a more reproducible and stable ischemic stroke following MCAO in SD rats.
Collapse
Affiliation(s)
- Ye Wu
- a Department of Neurosurgery , Tongde Hospital of Zhejiang Province , Hangzhou , China
| | - Lan Hu
- b Department of Neurology , The First People's Hospital of Wujiang , Suzhou , China
| | - Xiaosheng Yang
- c Department of Neurosurgery , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Xuhui Wang
- c Department of Neurosurgery , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Liang Wan
- c Department of Neurosurgery , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Xuming Hua
- c Department of Neurosurgery , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Juan Cheng
- d Department of Ultrasound , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Yi Li
- c Department of Neurosurgery , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China
| |
Collapse
|
8
|
Naderi S, Alimohammadi R, Hakimizadeh E, Roohbakhsh A, Shamsizadeh A, Allahtavakoli M. The effect of exercise preconditioning on stroke outcome in ovariectomized mice with permanent middle cerebral artery occlusion. Can J Physiol Pharmacol 2017; 96:287-294. [PMID: 28873322 DOI: 10.1139/cjpp-2017-0157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Exercise preconditioning has been shown to be effective in improving behavioral and neuropathological indices after cerebral ischemia. We evaluated the effect of exercise preconditioning, 17β-estradiol, and their combination on stroke outcome using an experimental model of stroke in ovariectomized (OVX) mice. OVX mice were randomly assigned to 4 groups as follows: control (stroke), exercise (exercise and stroke), estradiol (17β-estradiol and stroke), and exercise+estradiol (exercise and 17β-estradiol and stroke). Exercise preconditioning was performed on a treadmill 5 days/week, 40 min/day, at a speed of 18 m/min for 4 weeks. 17β-estradiol was gavaged (40 μg/kg per day) for 4 weeks. Stroke was induced by permanent middle cerebral artery occlusion (pMCAO), and neurological deficits were evaluated 1, 2, and 7 days after stroke. Then, the serum concentrations of matrix metalloproteinase-9 (MMP-9) and interleukin-10 (IL-10) and infarct volumes were assessed. Exercise preconditioning and 17β-estradiol induced a better outcome compared with the control ischemic mice, which was manifested by decrease in MMP-9, increase in IL-10, diminished infarct volume, and improved neurological deficits. Concomitant administration of 17β-estradiol and exercise also significantly improved these parameters. Exercise preconditioning or administration of 17β-estradiol alone or in combination before pMCAO induced significant neuroprotection in OVX mice.
Collapse
Affiliation(s)
- Soudabeh Naderi
- a Student Research Committee, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Raheleh Alimohammadi
- a Student Research Committee, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Elham Hakimizadeh
- d Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Ali Roohbakhsh
- b Pharmaceutical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,c Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Shamsizadeh
- d Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Mohammad Allahtavakoli
- d Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| |
Collapse
|
9
|
Potent neuroprotection after stroke afforded by a double-knot spider-venom peptide that inhibits acid-sensing ion channel 1a. Proc Natl Acad Sci U S A 2017; 114:3750-3755. [PMID: 28320941 DOI: 10.1073/pnas.1614728114] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stroke is the second-leading cause of death worldwide, yet there are no drugs available to protect the brain from stroke-induced neuronal injury. Acid-sensing ion channel 1a (ASIC1a) is the primary acid sensor in mammalian brain and a key mediator of acidosis-induced neuronal damage following cerebral ischemia. Genetic ablation and selective pharmacologic inhibition of ASIC1a reduces neuronal death following ischemic stroke in rodents. Here, we demonstrate that Hi1a, a disulfide-rich spider venom peptide, is highly neuroprotective in a focal model of ischemic stroke. Nuclear magnetic resonance structural studies reveal that Hi1a comprises two homologous inhibitor cystine knot domains separated by a short, structurally well-defined linker. In contrast with known ASIC1a inhibitors, Hi1a incompletely inhibits ASIC1a activation in a pH-independent and slowly reversible manner. Whole-cell, macropatch, and single-channel electrophysiological recordings indicate that Hi1a binds to and stabilizes the closed state of the channel, thereby impeding the transition into a conducting state. Intracerebroventricular administration to rats of a single small dose of Hi1a (2 ng/kg) up to 8 h after stroke induction by occlusion of the middle cerebral artery markedly reduced infarct size, and this correlated with improved neurological and motor function, as well as with preservation of neuronal architecture. Thus, Hi1a is a powerful pharmacological tool for probing the role of ASIC1a in acid-mediated neuronal injury and various neurological disorders, and a promising lead for the development of therapeutics to protect the brain from ischemic injury.
Collapse
|
10
|
An Evidence-Based Review of Related Metabolites and Metabolic Network Research on Cerebral Ischemia. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9162074. [PMID: 27274780 PMCID: PMC4871976 DOI: 10.1155/2016/9162074] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/27/2016] [Accepted: 04/14/2016] [Indexed: 11/17/2022]
Abstract
In recent years, metabolomics analyses have been widely applied to cerebral ischemia research. This paper introduces the latest proceedings of metabolomics research on cerebral ischemia. The main techniques, models, animals, and biomarkers of cerebral ischemia will be discussed. With analysis help from the MBRole website and the KEGG database, the altered metabolites in rat cerebral ischemia were used for metabolic pathway enrichment analyses. Our results identify the main metabolic pathways that are related to cerebral ischemia and further construct a metabolic network. These results will provide useful information for elucidating the pathogenesis of cerebral ischemia, as well as the discovery of cerebral ischemia biomarkers.
Collapse
|
11
|
Ström JO, Ingberg E. Impact of methodology on estrogens' effects on cerebral ischemia in rats: an updated meta-analysis. BMC Neurosci 2014; 15:22. [PMID: 24495535 PMCID: PMC3975994 DOI: 10.1186/1471-2202-15-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 01/29/2014] [Indexed: 12/15/2022] Open
Abstract
Background Although most animal stroke studies have demonstrated potent neuroprotective effects of estrogens, there are a number of articles reporting the opposite. In 2009, we made the case that this dichotomy was related to administered estrogen dose. Several other suggestions for the discordant results have also been propagated, including the age of the experimental animals and the length of hypoestrogenicity prior to estrogen administration. These two suggestions have gained much popularity, probably because of their kinship with the window of opportunity hypothesis, which is commonly used to explain the analogous dichotomy among human studies. We were therefore encouraged to perform an updated meta-analysis, and to improve it by including all relevant variables in a large multiple regression model, where the impact of confounders could be controlled for. Results The multiple regression model revealed an indisputable impact of estrogen administration mode on the effects of estrogens in ischemic stroke. Subcutaneous slow-release pellets differed from the injection and silastic capsule treatments in terms of impact of estrogens on ischemic stroke, showing that the first mentioned were more prone to render estrogens damaging. Neither the use of elderly animals nor the adoption of longer wash-out periods influenced estrogens’ effects on experimental ischemic stroke in rats. Conclusions We conclude that the discordant results regarding estrogens’ effects in rat models of ischemic stroke are a consequence of differences in estrogen administration modes. These results are not only of importance for the ongoing debate regarding menopausal hormone therapy, but also have an important bearing on experimental stroke methodology and the apparent translational roadblock for suggested stroke interventions.
Collapse
Affiliation(s)
- Jakob O Ström
- Vårdvetenskapligt Forskningscentrum/Centre for Health Sciences, Örebro University Hospital, County Council of Örebro, Örebro SE-703 62, Sweden.
| | | |
Collapse
|
12
|
The loss of estrogen efficacy against cerebral ischemia in aged postmenopausal female mice. Neurosci Lett 2014; 558:115-9. [DOI: 10.1016/j.neulet.2013.11.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 11/03/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022]
|
13
|
Inagaki T, Etgen AM. Neuroprotective action of acute estrogens: animal models of brain ischemia and clinical implications. Steroids 2013; 78:597-606. [PMID: 23385013 PMCID: PMC3733348 DOI: 10.1016/j.steroids.2012.12.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 12/20/2012] [Accepted: 12/28/2012] [Indexed: 10/27/2022]
Abstract
The ovarian hormone 17β-estradiol (E2) exerts profound neuroprotective actions against ischemia-induced brain damage in rodent models of global and focal ischemia. This review focuses on the neuroprotective efficacy of post-ischemic administration of E2 and non-feminizing estrogen analogs in the aging brain, with an emphasis on studies in animals subjected to a long-term loss of circulating E2. Clinical findings from the Women's Health Initiative study as well as data from animal studies that used long-term, physiological levels of E2 treatment are discussed in this context. We summarize major published findings that highlight the effective doses and timing of E2 treatment relative to onset of ischemia. We then discuss recent findings from our laboratory showing that under some conditions the aging hippocampus remains responsive to E2 and some neuroprotective non-feminizing estrogen analogs even after prolonged periods of hormone withdrawal. Possible membrane-initiated signaling mechanisms that may underlie the neuroprotective actions of acutely administered E2 are also discussed. Based on these findings, we suggest that post-ischemic treatment with high doses of E2 or certain non-feminizing estrogen analogs may have great therapeutic potential for treatment of brain damage and neurodegeneration associated with ischemia.
Collapse
Affiliation(s)
- Tomoko Inagaki
- Dominick P. Purpura Dept. of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
| | | |
Collapse
|
14
|
Hsiu H, Huang SM, Chen CT, Hsu CL, Hsu WC. Acupuncture stimulation causes bilaterally different microcirculatory effects in stroke patients. Microvasc Res 2011; 81:289-94. [DOI: 10.1016/j.mvr.2011.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/17/2011] [Accepted: 03/02/2011] [Indexed: 10/18/2022]
|
15
|
Mecca AP, O'Connor TE, Katovich MJ, Sumners C. Candesartan pretreatment is cerebroprotective in a rat model of endothelin-1-induced middle cerebral artery occlusion. Exp Physiol 2009; 94:937-46. [PMID: 19429641 DOI: 10.1113/expphysiol.2009.047936] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endogenous levels of angiotensin II (Ang II) are increased in the cortex and hypothalamus following stroke, and Ang II type 1 receptor blockers (ARBs) have been shown to attenuate the deleterious effects in animal stroke models using middle cerebral artery (MCA) intraluminal occlusion procedures. However, the endothelin-1 (ET-1)-induced middle cerebral artery occlusion (MCAO) model of cerebral ischaemia is thought to more closely mimic the temporal events of an embolic stroke. This method provides rapid occlusion of the MCA and a gradual reperfusion that lasts for 16-22 h. The aim of the present study was to evaluate whether systemic administration of an ARB prior to ET-1-induced MCAO would provide cerebroprotection during this model of ischaemic stroke. Injection of 3 microl of 80 microM ET-1 adjacent to the MCA resulted in complete occlusion of the vessel that resolved over a period of 30-40 min. Following ET-1-inducedMCAO, rats had significant neurological impairment, as well as an infarct that consisted of 30% of the ipsilateral grey matter. Systemic pretreatment with 0.2 mg kg(-1) day(-1) candesartan for 7 days attenuated both the infarct size and the neurological deficits caused by ET-1-induced MCAO without altering blood pressure. This study confirms the cerebroprotective properties of ARBs during ischaemic stroke and validates the ET-1-induced MCAO model for examination of the role of the brain renin-angiotensin system in ischaemic stroke.
Collapse
Affiliation(s)
- Adam P Mecca
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | | | | | | |
Collapse
|
16
|
De Butte-Smith M, Gulinello M, Zukin RS, Etgen AM. Chronic estradiol treatment increases CA1 cell survival but does not improve visual or spatial recognition memory after global ischemia in middle-aged female rats. Horm Behav 2009; 55:442-53. [PMID: 19124025 PMCID: PMC2656397 DOI: 10.1016/j.yhbeh.2008.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 10/24/2008] [Accepted: 11/30/2008] [Indexed: 01/31/2023]
Abstract
Transient global ischemia induces selective, delayed neuronal death in the hippocampal CA1 and cognitive deficits. Physiological levels of 17beta-estradiol ameliorate ischemia-induced neuronal death and cognitive impairments in young animals. In view of concerns regarding hormone therapy in postmenopausal women, we investigated whether chronic estradiol treatment initiated 14 days prior to ischemia attenuates ischemia-induced CA1 cell loss and impairments in visual and spatial memory, in ovariohysterectomized (OVX), middle-aged (9-11 months) female rats. To determine whether the duration of hormone withdrawal affects the efficacy of estradiol treatment, hormone treatment was initiated immediately (0 week), 1 week, or 8 weeks after OVX. Age-matched, OVX and gonadally intact females were studied at each OVX interval. Ischemia was induced 1 week after animals were pretested on a variety of behavioral tasks. Global ischemia produced significant neuronal loss in the CA1 and impaired performance on visual and spatial recognition. Chronic estradiol modestly but significantly increased the number of surviving CA1 neurons in animals at all OVX durations. However, in contrast with previous results in young females, estradiol did not preserve visual or spatial memory performance in middle-aged females. All animals displayed normal locomotion, spontaneous alternation and social preference, indicating the absence of global behavioral impairments. Therefore, the neuroprotective effects of estradiol are different in middle-aged than in young rats. These findings highlight the importance of using older animals in studies assessing potential treatments for focal and global ischemia.
Collapse
Affiliation(s)
- M De Butte-Smith
- Albert Einstein College of Medicine, Dominick P. Purpura Department of Neuroscience, Bronx, New York 10461, USA
| | | | | | | |
Collapse
|