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Ishiyama H, Tanaka T, Saito S, Koyama T, Kitamura A, Inoue M, Fukushima N, Morita Y, Koga M, Toyoda K, Kuriyama N, Urushitani M, Ihara M. Plasma mid-regional pro-adrenomedullin: A biomarker of the ischemic penumbra in hyperacute stroke. Brain Pathol 2022; 33:e13110. [PMID: 35916272 PMCID: PMC10041162 DOI: 10.1111/bpa.13110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/15/2022] [Indexed: 12/01/2022] Open
Abstract
Reperfusion therapy has improved the outcomes of ischemic stroke but also emphasized the importance of ischemic penumbra. However, blood biomarkers are currently unavailable for this region. Adrenomedullin (ADM) is a neuroprotective peptide, secreted in a compensatory response to brain ischemia. We thus investigated whether an increase in mid-regional pro-ADM (MR-proADM), a stable peptide fragment of the ADM precursor, could act as a biomarker by predicting the ischemic penumbra in hyperacute ischemic stroke (HAIS). We prospectively enrolled consecutive HAIS patients (n = 119; median age, 77 years; male, 59.7%) admitted to our institutes from July 2017 to March 2019 and evaluated plasma MR-proADM levels within 4.5 h of onset. MR-proADM levels in HAIS were compared to healthy controls (n = 1298; median age, 58 years; male, 33.2%) in the Japan Multi-Institutional Collaborative Cohort Study from 2013 to 2017. Furthermore, we evaluated whether MR-proADM levels were associated with the penumbra estimated by clinical-diffusion mismatch (CDM) (National Institute of Health Stroke Scale [NIHSS] ≥8, diffusion ischemic core volume ≤25 ml), or magnetic resonance angiography-diffusion-weighted imaging mismatch (MDM) (NIHSS ≥5, a proximal vessel occlusion with core volume ≤25 ml, or a proximal vessel stenosis/distal vessel occlusion with core volume ≤15 ml). In a case-control study, multivariate logistic analysis showed a significant association between HAIS and MR-proADM ≥0.54 nmol/L (adjusted odds ratio, 7.92 [95% CI, 4.17-15.02], p < 0.001). Though MR-proADM levels in HAIS did not correlate with the ischemic core volume (rs = 0.09, p = 0.348), they were higher in HAIS with CDM (n = 34; 0.81 vs. 0.61 nmol/L, p < 0.001) or MDM (n = 26; 0.83 vs. 0.62 nmol/L, p = 0.002). These differences remained significant after adjusting baseline factors (adjusted odds ratio, 4.06 [95% CI, 1.31-12.55], p = 0.015 and 4.65 [1.35-16.11], p = 0.015, respectively). Plasma MR-proADM is elevated in HAIS, especially in those with a substantial penumbra, suggesting potential as a blood biomarker in this region.
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Affiliation(s)
- Hiroyuki Ishiyama
- Department of NeurologyNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Tomotaka Tanaka
- Department of NeurologyNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Satoshi Saito
- Department of NeurologyNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Teruhide Koyama
- Department of Epidemiology for Community Health and MedicineKyoto Prefectural University of MedicineKyotoJapan
| | - Akihiro Kitamura
- Department of NeurologyShiga University of Medical ScienceOtsuJapan
| | - Manabu Inoue
- Department of Cerebrovascular MedicineNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Naoya Fukushima
- Department of NeurologyNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Yoshiaki Morita
- Department of RadiologyNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Masatoshi Koga
- Department of Cerebrovascular MedicineNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Kazunori Toyoda
- Department of Cerebrovascular MedicineNational Cerebral and Cardiovascular CenterSuitaJapan
| | - Nagato Kuriyama
- Department of Epidemiology for Community Health and MedicineKyoto Prefectural University of MedicineKyotoJapan
- Shizuoka Graduate University of Public HealthShizuokaJapan
| | | | - Masafumi Ihara
- Department of NeurologyNational Cerebral and Cardiovascular CenterSuitaJapan
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Yoshimoto T, Saito S, Omae K, Hattori Y, Fukuma K, Kitamura K, Kakuta R, Kita T, Maruyama H, Yamamoto H, Ihara M. Study Protocol for a Randomized, Double-Blind, Placebo-Controlled, Phase-II Trial: AdrenoMedullin for Ischemic Stroke Study. J Stroke Cerebrovasc Dis 2021; 30:105761. [PMID: 33813084 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105761] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/14/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Adrenomedullin (AM), a vasoactive peptide, has strong anti-inflammatory and angiogenic properties, which have been reported to ameliorate the consequences of ischemic stroke in several animal models. After a phase I study in healthy volunteers, two phase II trials of AM for inflammatory bowel diseases have been recently completed. The current AdrenoMedullin For Ischemic Stroke (AMFIS) study aims to assess the safety and efficacy of AM in patients with acute ischemic stroke. MATERIALS AND METHODS The AMFIS study is an investigator-initiated, randomized, double-blind, phase-II trial. AM or placebo will be administered to patients with non-cardioembolic ischemic stroke within 24 h after stroke onset. In the first cohort of the AMFIS study, patients will be randomly allocated to the investigation treatment A (30 μg/kg of AM in total for 7 days, n = 20) or placebo group (n = 10). In the second cohort, patients will be assigned to the investigation treatment B (56 μg/kg of AM in total for 7 days, n = 20) or placebo group (n = 10). RESULTS Serious adverse events related to the protocol treatment will be evaluated as the primary outcome. All adverse events will be analyzed as the secondary outcome. Regarding efficacy endpoints, the change in National Institutes of Health Stroke Scale and modified Rankin Scale scores will be compared between investigation treatment and placebo groups. CONCLUSIONS AM is expected to be a safe and effective treatment for ischemic stroke.
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Affiliation(s)
- Takeshi Yoshimoto
- Department of Neurology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565, Japan; Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan.
| | - Satoshi Saito
- Department of Neurology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565, Japan; Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Japan.
| | - Katsuhiro Omae
- Department of Data Science, National Cerebral and Cardiovascular Center, Suita, Japan.
| | - Yorito Hattori
- Department of Neurology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565, Japan.
| | - Kazuki Fukuma
- Department of Neurology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565, Japan.
| | - Kazuo Kitamura
- Division of Circulatory and Body Fluid Regulation, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
| | - Ryosuke Kakuta
- Department of Data Science, National Cerebral and Cardiovascular Center, Suita, Japan.
| | - Toshihiro Kita
- Division of Circulatory and Body Fluid Regulation, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan.
| | - Haruko Yamamoto
- Department of Data Science, National Cerebral and Cardiovascular Center, Suita, Japan.
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shimmachi, Suita, Osaka 564-8565, Japan.
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Ihara M, Washida K, Yoshimoto T, Saito S. Adrenomedullin: A vasoactive agent for sporadic and hereditary vascular cognitive impairment. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2021; 2:100007. [PMID: 36324729 PMCID: PMC9616331 DOI: 10.1016/j.cccb.2021.100007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/14/2021] [Accepted: 02/26/2021] [Indexed: 04/16/2023]
Abstract
Adrenomedullin (AM) is an endogenous peptide mainly secreted from endothelial cells, which has multiple physiological actions such as anti-inflammation, vasodilation, vascular permeability regulation and angiogenesis. Blood AM levels are upregulated in a variety of pathological states including sepsis, severe COVID-19, acute ischemic stroke and vascular cognitive impairment with white matter changes, likely serving as a compensatory biological defense response against infection and ischemia. AM is currently being tested in clinical trials for ulcerative colitis, Crohn's disease, severe COVID-19 for its anti-inflammatory properties and in ischemic stroke for its additional angiogenic action. AM has been proposed as a therapeutic option for vascular cognitive impairment as its arteriogenic and angiogenic properties are thought to contribute to a slowing of cognitive decline in mice after chronic cerebral hypoperfusion. As AM promotes differentiation of oligodendrocyte precursor cells into mature oligodendrocytes under hypoxic conditions, AM could also be used in the treatment of CADASIL, where reduced oxygen delivery is thought to lead to the death of hypoxia-prone oligodendrocytes. AM therefore holds potential as an innovative therapeutic drug, which may regenerate blood vessels, while controlling inflammation in cerebrovascular diseases.
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Inaba T, Miyamoto N, Hira K, Ueno Y, Yamashiro K, Watanabe M, Shimada Y, Hattori N, Urabe T. Protective Role of Levetiracetam Against Cognitive Impairment And Brain White Matter Damage in Mouse prolonged Cerebral Hypoperfusion. Neuroscience 2019; 414:255-264. [PMID: 31302262 DOI: 10.1016/j.neuroscience.2019.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 10/26/2022]
Abstract
White matter lesions due to cerebral hypoperfusion may be an important pathophysiology in vascular dementia and stroke, although the inherent mechanisms remain to be fully elucidated. The present study, using a mouse model of chronic cerebral hypoperfusion, examined the white matter protective effects of levetiracetam, an anticonvulsant, via the signaling cascade from the activation of cAMP-responsive element binding protein (CREB) phosphorylation. Mice underwent bilateral common carotid artery stenosis (BCAS), and were separated into the levetiracetam group (injected once only after BCAS [LEV1] or injected on three consecutive days [LEV3]), the vehicle group, or the anti-epileptic drugs with different action mechanisms phenytoin group (PHT3; injected on three consecutive days with the same condition as in LEV3). Cerebral blood flow analysis, Y-maze spontaneous alternation test, novel object recognition test, immunohistochemical and Western blot analyses, and protein kinase A assay were performed after BCAS. In the LEV3 group, SV2A expression was markedly increased, which preserved learning and memory after BCAS. Moreover, as the protein kinase A level was significantly increased, pCREB expression was also increased. The activation of microglia and astrocytes was markedly suppressed, although the number of oligodendrocyte precursor cells (OPCs) and GST-pi-positive-oligodendrocytes was markedly higher in the cerebral white matter. Moreover, oxidative stress was significantly reduced. We found that 3-day treatment with levetiracetam maintained SV2A protein expression via interaction with astrocytes, which influenced the OPC lineage through activation of CREB to protect white matter from ischemia.
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Affiliation(s)
- Toshiki Inaba
- Department of Neurology, Juntendo University Urayasu Hospital, Chiba, Japan; Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Nobukazu Miyamoto
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
| | - Kenichiro Hira
- Department of Neurology, Juntendo University Urayasu Hospital, Chiba, Japan
| | - Yuji Ueno
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Kazuo Yamashiro
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Masao Watanabe
- Department of Neurology, Juntendo University Urayasu Hospital, Chiba, Japan
| | - Yoshiaki Shimada
- Department of Neurology, Juntendo University Urayasu Hospital, Chiba, Japan; Department of Neurological Science, Yokohama Tsurugamine Hospital, Yokohama, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Takao Urabe
- Department of Neurology, Juntendo University Urayasu Hospital, Chiba, Japan
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Ferrero H, Larrayoz IM, Gil-Bea FJ, Martínez A, Ramírez MJ. Adrenomedullin, a Novel Target for Neurodegenerative Diseases. Mol Neurobiol 2018; 55:8799-8814. [PMID: 29600350 DOI: 10.1007/s12035-018-1031-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/22/2018] [Indexed: 01/18/2023]
Abstract
Neurodegenerative diseases represent a heterogeneous group of disorders whose common characteristic is the progressive degeneration of neuronal structure and function. Although much knowledge has been accumulated on the pathophysiology of neurodegenerative diseases over the years, more efforts are needed to understand the processes that underlie these diseases and hence to propose new treatments. Adrenomedullin (AM) is a multifunctional peptide involved in vasodilation, hormone secretion, antimicrobial defense, cellular growth, and angiogenesis. In neurons, AM and related peptides are associated with some structural and functional cytoskeletal proteins that interfere with microtubule dynamics. Furthermore, AM may intervene in neuronal dysfunction through other mechanisms such as immune and inflammatory response, apoptosis, or calcium dyshomeostasis. Alterations in AM expression have been described in neurodegenerative processes such as Alzheimer's disease or vascular dementia. This review addresses the current state of knowledge on AM and its possible implication in neurodegenerative diseases.
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Affiliation(s)
- Hilda Ferrero
- Department of Pharmacology and Toxicology, and IdiSNA, Navarra Institute for Health Research, University of Navarra, Pamplona, Spain
| | - Ignacio M Larrayoz
- Biomarkers and Molecular Signaling, Center for Biomedical Research of La Rioja (CIBIR), Logroño, Spain
| | - Francisco J Gil-Bea
- Department of Pharmacology and Toxicology, and IdiSNA, Navarra Institute for Health Research, University of Navarra, Pamplona, Spain
- Neuroscience Area, Biodonostia Health Research Institute, CIBERNED, San Sebastian, Spain
| | - Alfredo Martínez
- Oncology Area, Center for Biomedical Research of La Rioja (CIBIR), Logroño, Spain
| | - María J Ramírez
- Department of Pharmacology and Toxicology, and IdiSNA, Navarra Institute for Health Research, University of Navarra, Pamplona, Spain.
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6
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Neuropeptides and Microglial Activation in Inflammation, Pain, and Neurodegenerative Diseases. Mediators Inflamm 2017; 2017:5048616. [PMID: 28154473 PMCID: PMC5244030 DOI: 10.1155/2017/5048616] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/26/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022] Open
Abstract
Microglial cells are responsible for immune surveillance within the CNS. They respond to noxious stimuli by releasing inflammatory mediators and mounting an effective inflammatory response. This is followed by release of anti-inflammatory mediators and resolution of the inflammatory response. Alterations to this delicate process may lead to tissue damage, neuroinflammation, and neurodegeneration. Chronic pain, such as inflammatory or neuropathic pain, is accompanied by neuroimmune activation, and the role of glial cells in the initiation and maintenance of chronic pain has been the subject of increasing research over the last two decades. Neuropeptides are small amino acidic molecules with the ability to regulate neuronal activity and thereby affect various functions such as thermoregulation, reproductive behavior, food and water intake, and circadian rhythms. Neuropeptides can also affect inflammatory responses and pain sensitivity by modulating the activity of glial cells. The last decade has witnessed growing interest in the study of microglial activation and its modulation by neuropeptides in the hope of developing new therapeutics for treating neurodegenerative diseases and chronic pain. This review summarizes the current literature on the way in which several neuropeptides modulate microglial activity and response to tissue damage and how this modulation may affect pain sensitivity.
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Kim HN, Gil CH, Kim YR, Shin HK, Choi BT. Anti-photoaging properties of the phosphodiesterase 3 inhibitor cilostazol in ultraviolet B-irradiated hairless mice. Sci Rep 2016; 6:31169. [PMID: 27484958 PMCID: PMC4971469 DOI: 10.1038/srep31169] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/13/2016] [Indexed: 12/27/2022] Open
Abstract
We investigated whether cilostazol, an activator of cyclic adenosine monophosphate (cAMP)-dependent intracellular signaling, could inhibit ultraviolet B (UVB) irradiation-induced photoaging in HR-1 hairless mice. Cilostazol decreased wrinkle formation and skin thickness in UVB-irradiated mice, as well as increased staining of collagen fibers and inhibition of reactive oxygen species (ROS) formation in the skin. Moreover, the proteolytic activities of gelatinase matrix metalloproteinase (MMP)-9 and collagenase MMP-3 were significantly decreased in UVB-irradiated mice treated with cilostazol. Western blotting showed that UVB-induced activation of p38 mitogen-activated protein kinases (MAPK) and nuclear factor (NF)-κB was significantly inhibited by cilostazol, whereas the activation of Akt was significantly enhanced by cilostazol. Confirmation of localized protein expression in the skin revealed marked p38 MAPK and NF-κB activation that was mainly detected in the dermis. Marked Akt activation was mainly detected in the epidermis. Our results suggest that cilostazol may have anti-photoaging effects on UVB-induced wrinkle formation by maintaining the extracellular matrix density in the dermis, which occurs via regulation of ROS and related p38 MAPK and NF-κB signaling, and subsequent down-regulation of MMPs. Therefore, cilostazol may protect against photoaging-induced wrinkle formation.
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Affiliation(s)
- Ha Neui Kim
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea.,Korean Medical Science Research Center for Healthy-Aging, Pusan National University, Yangsan 50612, Korea
| | - Chan Hee Gil
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea
| | - Yu Ri Kim
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea.,Korean Medical Science Research Center for Healthy-Aging, Pusan National University, Yangsan 50612, Korea
| | - Hwa Kyoung Shin
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea.,Korean Medical Science Research Center for Healthy-Aging, Pusan National University, Yangsan 50612, Korea.,Division of Meridian and Structural Medicine, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea
| | - Byung Tae Choi
- Department of Korean Medical Science, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea.,Korean Medical Science Research Center for Healthy-Aging, Pusan National University, Yangsan 50612, Korea.,Division of Meridian and Structural Medicine, School of Korean Medicine, Pusan National University, Yangsan 50612, Korea
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8
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Kato J, Kitamura K. Bench-to-bedside pharmacology of adrenomedullin. Eur J Pharmacol 2015; 764:140-148. [PMID: 26144371 DOI: 10.1016/j.ejphar.2015.06.061] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/24/2015] [Accepted: 06/30/2015] [Indexed: 01/01/2023]
Abstract
The bioactive peptide adrenomedullin (AM) exerts pleiotropic actions in various organs and tissues. In the heart, AM has an inhibitory effect on ventricular remodeling, suppressing cardiomyocyte hypertrophy and the proliferation of cardiac fibroblasts. This pharmacological property was shown not only in rat models of acute myocardial infarction, but also clinically in patients with this cardiac disease. An originally characterized feature of AM was a potent vasodilatory effect, but this peptide was found to be important for vascular integrity and angiogenesis. AM-induced angiogenesis is involved in tumor growth, while AM inhibits apoptosis of some types of tumor cell. A unique pharmacological property is anti-inflammatory activity, which has been characterized in sepsis and inflammatory bowel diseases; thus, there is an ongoing clinical trial to test the efficacy of AM for patients with intractable ulcerative colitis. These activities are assumed to be mediated via the specific receptor formed by calcitonin receptor-like receptor and receptor activity-modifying protein 2 or 3, while some questions remain to be answered about the molecular mechanisms of this signal transduction system. Taking these findings together, AM is a bioactive peptide with pleiotropic effects, with potential as a therapeutic tool for a wide range of human diseases from myocardial infarction to malignant tumors or inflammatory bowel diseases.
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Affiliation(s)
- Johji Kato
- Frontier Science Research Center, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan.
| | - Kazuo Kitamura
- Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan
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Maki T, Takahashi Y, Miyamoto N, Liang AC, Ihara M, Lo EH, Arai K. Adrenomedullin promotes differentiation of oligodendrocyte precursor cells into myelin-basic-protein expressing oligodendrocytes under pathological conditions in vitro. Stem Cell Res 2015; 15:68-74. [PMID: 26002630 DOI: 10.1016/j.scr.2015.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 04/25/2015] [Accepted: 05/03/2015] [Indexed: 12/28/2022] Open
Abstract
Oligodendrocytes, which are the main cell type in cerebral white matter, are generated from their precursor cells (oligodendrocyte precursor cells: OPCs). However, the differentiation from OPCs to oligodendrocytes is disturbed under stressed conditions. Therefore, drugs that can improve oligodendrocyte regeneration may be effective for white matter-related diseases. Here we show that a vasoactive peptide adrenomedullin (AM) promotes the in vitro differentiation of OPCs under pathological conditions. Primary OPCs were prepared from neonatal rat brains, and differentiated into myelin-basic-protein expressing oligodendrocytes over time. This in vitro OPC differentiation was inhibited by prolonged chemical hypoxic stress induced by non-lethal CoCl(2) treatment. However, AM promoted the OPC differentiation under the hypoxic stress conditions, and the AM receptor antagonist AM(22-52) canceled the AM-induced OPC differentiation. In addition, AM treatment increased the phosphorylation level of Akt in OPC cultures, and correspondingly, the PI3K/Akt inhibitor LY294002 blocked the AM-induced OPC differentiation. Taken together, AM treatment rescued OPC maturation under pathological conditions via an AM-receptor-PI3K/Akt pathway. Oligodendrocytes play critical roles in white matter by forming myelin sheath. Therefore, AM signaling may be a promising therapeutic target to boost oligodendrocyte regeneration in CNS disorders.
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Affiliation(s)
- Takakuni Maki
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA
| | - Yoko Takahashi
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA; Department of Developmental Neuroscience, United Centers for Advanced Research and Translational Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Nobukazu Miyamoto
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA
| | - Anna C Liang
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA
| | - Masafumi Ihara
- Department of Stroke and Cerebrovascular Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Eng H Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, MA General Hospital, Harvard Medical School, USA.
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Igarashi K, Sakurai T, Kamiyoshi A, Ichikawa-Shindo Y, Kawate H, Yamauchi A, Toriyama Y, Tanaka M, Liu T, Xian X, Imai A, Zhai L, Owa S, Koyama T, Uetake R, Ihara M, Shindo T. Pathophysiological roles of adrenomedullin-RAMP2 system in acute and chronic cerebral ischemia. Peptides 2014; 62:21-31. [PMID: 25252154 DOI: 10.1016/j.peptides.2014.08.013] [Citation(s) in RCA: 13] [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: 06/26/2014] [Revised: 08/25/2014] [Accepted: 08/25/2014] [Indexed: 11/20/2022]
Abstract
The accessory protein RAMP2 is a component of the CLR/RAMP2 dimeric adrenomedullin (AM) receptor and is the primary determinant of the vascular functionality of AM. RAMP2 is highly expressed in the brain; however, its function there remains unclear. We therefore used heterozygous RAMP2 knockout (RAMP2+/-) mice, in which RAMP2 expression was reduced by half, to examine the actions of the endogenous AM-RAMP2 system in cerebral ischemia. To induce acute or chronic ischemia, mice were subjected to middle cerebral artery occlusion (MCAO) or bilateral common carotid artery stenosis (BCAS), respectively. In RAMP2+/- mice subjected to MCAO, recovery of cerebral blood flow (CBF) was slower than in WT mice. AM gene expression was upregulated after infarction in both genotypes, but the increase was greater in RAMP2+/- mice. Pathological analysis revealed severe nerve cell death and demyelination, and a higher level of oxidative stress in RAMP2+/- mice. In RAMP2+/- mice subjected to BCAS, recovery of cerebral perfusion was slower and less complete than in WT mice. In an 8-arm radial maze test, RAMP2+/- mice required more time to solve the maze and showed poorer reference memory. They also showed greater reductions in nerve cells and less compensatory capillary growth than WT mice. These results indicate the AM-RAMP2 system works to protect nerve cells from both acute and chronic cerebral ischemia by maintaining CBF, suppressing oxidative stress, and in the case of chronic ischemia, enhancing capillary growth.
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Affiliation(s)
- Kyoko Igarashi
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Takayuki Sakurai
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Akiko Kamiyoshi
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Yuka Ichikawa-Shindo
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Hisaka Kawate
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Akihiro Yamauchi
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Yuichi Toriyama
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Megumu Tanaka
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Tian Liu
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Xian Xian
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Akira Imai
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Liuyu Zhai
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Shinji Owa
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Teruhide Koyama
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Ryuichi Uetake
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan
| | - Masafumi Ihara
- Department of Regenerative Medicine, Research Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Takayuki Shindo
- Department of Cardiovascular Research, Shinshu University Graduate School of Medicine, Matsumoto, Japan.
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Chen TJ, Fu QY, Wu WQ. Plasma levels of adrenomedullin in patients with traumatic brain injury: potential contribution to prognosis. Peptides 2014; 56:146-50. [PMID: 24747282 DOI: 10.1016/j.peptides.2014.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 04/04/2014] [Accepted: 04/04/2014] [Indexed: 01/05/2023]
Abstract
High plasma levels of adrenomedullin have been associated with stroke severity and clinical outcomes. This study aimed to analyze plasma levels of adrenomedullin in traumatic brain injury and their association with prognosis. One hundred and forty-eight acute severe traumatic brain injury and 148 sex- and age-matched healthy controls were recruited in this study. Plasma adrenomedullin concentration was measured by enzyme-linked immunosorbent assay. Unfavorable outcome was defined as Glasgow Outcome Scale score of 1-3. Compared to controls, the patients had significantly higher plasma concentrations of adrenomedullin, which were also highly associated negatively with Glasgow Coma Scale score. Plasma adrenomedullin level was proved to be an independent predictor for 6-month mortality and unfavorable outcome of patients in a multivariate analysis. A receiver operating characteristic curve was configured to show that a baseline plasma adrenomedullin level predicted 6-month mortality and unfavorable outcome of patients with high area under curve. The predictive performance of the plasma adrenomedullin concentration was also similar to that of Glasgow Coma Scale score for the prediction of 6-month mortality and unfavorable outcome of patients. In a combined logistic-regression model, adrenomedullin improved the area under curve of Glasgow Coma Scale score for the prediction of 6-month mortality and unfavorable outcome of patients, but the differences did not appear to be statistically significant. Thus, high plasma levels of adrenomedullin are associated with head trauma severity, and may independently predict long-term clinical outcomes of traumatic brain injury.
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Affiliation(s)
- Tie-Jiang Chen
- Department of Emergency Surgery, Yiwu Central Hospital, 699 Jiangdong Road, Yiwu 322000, Zhejiang Province, China.
| | - Qing-Yang Fu
- Department of Emergency Surgery, Yiwu Central Hospital, 699 Jiangdong Road, Yiwu 322000, Zhejiang Province, China
| | - Wu-Quan Wu
- Department of Emergency Surgery, Yiwu Central Hospital, 699 Jiangdong Road, Yiwu 322000, Zhejiang Province, China
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Wang CL, Lin HY, Xu JW, Jiang FF, Yang M, Wang JH, Huang XQ. Blood levels of adrenomedullin on admission predict outcomes after acute intracerebral hemorrhage. Peptides 2014; 54:27-32. [PMID: 24457114 DOI: 10.1016/j.peptides.2014.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 11/29/2022]
Abstract
Increased plasma adrenomedullin level has been associated with critical illness. This study aimed to investigate the correlations of plasma adrenomedullin concentration with 3-month clinical outcomes and early neurological deterioration of patients with acute intracerebral hemorrhage. One hundred fourteen patients and 112 healthy controls were recruited. Relationships of plasma adrenomedullin concentrations with early neurological deterioration, 3-month mortality and unfavorable outcome (modified Rankin Scale score >2) were evaluated. Plasma adrenomedullin concentrations were increased in patients than in healthy individuals and were highly associated with National Institutes of Health Stroke Scale scores. A multivariate analysis selected plasma adrenomedullin concentration as an independent predictor for 3-month clinical outcomes and early neurological deterioration. A receiver operating characteristic curve analysis showed plasma adrenomedullin concentration predicted 3-month clinical outcomes and early neurological deterioration with high area under curves. The predictive value of adrenomedullin was similar to that of National Institutes of Health Stroke Scale score. In a combined logistic-regression model, adrenomedullin did not improve the predictive value of National Institutes of Health Stroke Scale score. Thus, elevated plasma adrenomedullin concentration is highly associated with 3-month clinical outcomes and early neurological deterioration of patients with acute intracerebral hemorrhage.
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Affiliation(s)
- Chuan-Liu Wang
- Department of Neurology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
| | - Hai-Yan Lin
- Department of Neurology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China.
| | - Jian-Wei Xu
- Department of Urology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
| | - Fei-Fei Jiang
- Department of Neurology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
| | - Ming Yang
- Department of Neurology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
| | - Jin-Hua Wang
- Department of Neurology, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
| | - Xiu-Qing Huang
- Department of Rehabilitation, Quzhou People's Hospital, 2 Zhongloudi Road, Kecheng District, Quzhou 324000, China
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Adrenomedullin-RAMP2 system suppresses ER stress-induced tubule cell death and is involved in kidney protection. PLoS One 2014; 9:e87667. [PMID: 24505304 PMCID: PMC3914859 DOI: 10.1371/journal.pone.0087667] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 12/29/2013] [Indexed: 11/19/2022] Open
Abstract
Various bioactive peptides have been implicated in the homeostasis of organs and tissues. Adrenomedullin (AM) is a peptide with various bioactivities. AM-receptor, calcitonin-receptor-like receptor (CLR) associates with one of the subtypes of the accessory proteins, RAMPs. Among the RAMP subisoforms, only RAMP2 knockout mice (−/−) reproduce the phenotype of embryonic lethality of AM−/−, illustrating the importance of the AM-RAMP2-signaling system. Although AM and RAMP2 are abundantly expressed in kidney, their function there remains largely unknown. We used genetically modified mice to assess the pathophysiological functions of the AM-RAMP2 system. RAMP2+/− mice and their wild-type littermates were used in a streptozotocin (STZ)-induced renal injury model. The effect of STZ on glomeruli did not differ between the 2 types of mice. On the other hand, damage to the proximal urinary tubules was greater in RAMP2+/−. Tubular injury in RAMP2+/− was resistant to correction of blood glucose by insulin administration. We examined the effect of STZ on human renal proximal tubule epithelial cells (RPTECs), which express glucose transporter 2 (GLUT2), the glucose transporter that specifically takes up STZ. STZ activated the endoplasmic reticulum (ER) stress sensor protein kinase RNA-like endoplasmic reticulum kinase (PERK). AM suppressed PERK activation, its downstream signaling, and CCAAT/enhancer-binding homologous protein (CHOP)-induced cell death. We confirmed that the tubular damage was caused by ER stress-induced cell death using tunicamycin (TUN), which directly evokes ER stress. In RAMP2+/− kidneys, TUN caused severe injury with enhanced ER stress. In wild-type mice, TUN-induced tubular damage was reversed by AM administration. On the other hand, in RAMP2+/−, the rescue effect of exogenous AM was lost. These results indicate that the AM-RAMP2 system suppresses ER stress-induced tubule cell death, thereby exerting a protective effect on kidney. The AM-RAMP2 system thus has the potential to serve as a therapeutic target in kidney disease.
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Akpinar A, Yaman GB, Demirdas A, Onal S. Possible role of adrenomedullin and nitric oxide in major depression. Prog Neuropsychopharmacol Biol Psychiatry 2013; 46:120-5. [PMID: 23867466 DOI: 10.1016/j.pnpbp.2013.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/02/2013] [Accepted: 07/03/2013] [Indexed: 01/01/2023]
Abstract
Adrenomedullin (ADM) and nitric oxide (NO) have been implicated in the pathogenesis of certain psychiatric disorders such as schizophrenia and bipolar disorder. ADM induces vasorelaxation by activating adenylate cyclase and stimulating the release of NO. These two molecules are known to influence cerebral activity. In this study, we aimed to examine the serum levels of ADM and NO in patients with major depression (MD). We enrolled 50 patients with MD and 50 healthy control subjects. The diagnosis of MD was established on the basis of a structured clinical interview using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The severity of depressive symptoms was evaluated using Hamilton's 17-item Depression Rating Scale. The mean serum levels of ADM and NO in patients with MD were significantly higher than those in healthy subjects (p=0.001, for both). The severity of psychomotor retardation in patients with MD was significantly correlated with the ADM (r=0.37, p=0.007) and NO levels (r=0.29, p=0.038). The patients with obvious psychomotor retardation had significantly higher levels of ADM and NO than did the patients with no psychomotor retardation (p=0.025, p=0.030). A significantly positive correlation was found between ADM and NO levels in patients with MD (r=0.79, p=0.001). Serum levels of ADM and NO levels were not correlated with the severity or duration of depression or depressive symptoms (except psychomotor retardation). In conclusion, our study indicates that serum levels of ADM and NO are elevated in patients with MD and that increased serum levels of ADM and NO may be associated with psychomotor retardation. The ADM-NO system may serve as a new target in the treatment of patients with MD and psychomotor retardation.
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Affiliation(s)
- Abdullah Akpinar
- Department of Psychiatry, Suleyman Demirel University School of Medicine, Isparta, Turkey.
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15
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Liu J, Yan J, Greer JM, Read SJ, Henderson RD, Rose SE, Coulthard A, McCombe PA. Correlation of Adrenomedullin gene expression in peripheral blood leukocytes with severity of ischemic stroke. Int J Neurosci 2013; 124:271-80. [DOI: 10.3109/00207454.2013.837462] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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16
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Mitome-Mishima Y, Miyamoto N, Tanaka R, Oishi H, Arai H, Hattori N, Urabe T. Differences in phosphodiesterase 3A and 3B expression after ischemic insult. Neurosci Res 2013; 75:340-8. [DOI: 10.1016/j.neures.2013.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/31/2013] [Accepted: 02/04/2013] [Indexed: 11/30/2022]
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Hara S, Kobayashi M, Kuriiwa F, Mukai T, Mizukami H. Dual contradictory roles of cAMP signaling pathways in hydroxyl radical production in the rat striatum. Free Radic Biol Med 2012; 52:1086-92. [PMID: 22269608 DOI: 10.1016/j.freeradbiomed.2012.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/19/2011] [Accepted: 01/03/2012] [Indexed: 10/14/2022]
Abstract
Studies have suggested that cAMP signaling pathways may be associated with the production of reactive oxygen species. In this study, we examined how modifications in cAMP signaling affected the production of hydroxyl radicals in rat striatum using microdialysis to measure extracellular 2,3-dihydroxybenzoic acid (2,3-DHBA), which is a hydroxyl radical adduct of salicylate. Up to 50 nmol of the cell-permeative cAMP mimetic 8-bromo-cAMP (8-Br-cAMP) increased 2,3-DHBA in a dose-dependent manner (there was no additional increase in 2,3-DHBA at 100 nmol). Another cAMP mimetic, dibutyryl cAMP (db-cAMP), caused a nonsignificant increase in 2,3-DHBA at 50 nmol and a significant decrease at 100 nmol. Up to 20 nmol of forskolin, which is a direct activator of adenylyl cyclase, increased 2,3-DHBA, similar to the effect of 8-Br-cAMP; however, forskolin resulted in a much greater increase in 2,3-DHBA. A potent inhibitor of protein kinase A (PKA), H89 (500 μM), potentiated the 8-Br-cAMP- and forskolin-induced increases in 2,3-DHBA and antagonized the inhibitory effect of 100 nmol of db-cAMP. Interestingly, the administration of 100 nmol of 8-bromo-cGMP alone or in combination with H89 had no significant effect on 2,3-DHBA levels. Doses of 100 nmol of a preferential PKA activator (6-phenyl-cAMP) or a preferential PKA inhibitor (8-bromoadenosine-3',5'-cyclic monophosphorothionate, Rp-isomer; Rp-8-Br-cAMPS), which also inhibits the cAMP-mediated activation of Epac (the exchange protein directly activated by cAMP), suppressed or enhanced, respectively, the formation of 2,3-DHBA. Up to 100 nmol of 8-(4-chlorophenylthio)-2'-O-methyladenosine-cAMP, which is a selective activator of Epac, dose-dependently stimulated the formation of 2,3-DHBA. These findings suggest that cAMP signaling plays contradictory roles (stimulation and inhibition) in the production of hydroxyl radicals in rat striatum by differential actions of Epac and PKA. These roles might contribute to the production of hydroxyl radicals concomitant with cAMP in carbon monoxide poisoning, because the formation of 2,3-DHBA was potentiated by the PKA inhibitor H89 and suppressed by Rp-8-Br-cAMPS, which inhibits PKA and Epac.
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Affiliation(s)
- Shuichi Hara
- Department of Forensic Medicine, Tokyo Medical University, Tokyo 160-8402, Japan.
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Ihara M, Tomimoto H. Lessons from a mouse model characterizing features of vascular cognitive impairment with white matter changes. J Aging Res 2011; 2011:978761. [PMID: 22132331 PMCID: PMC3216359 DOI: 10.4061/2011/978761] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 07/26/2011] [Indexed: 01/13/2023] Open
Abstract
With the demographic shift in age in advanced countries inexorably set to progress in the 21st century, dementia will become one of the most important health problems worldwide. Vascular cognitive impairment is the second most common type of dementia after Alzheimer's disease and is frequently responsible for the cognitive decline of the elderly. It is characterized by cerebrovascular white matter changes; thus, in order to investigate the underlying mechanisms involved in white matter changes, a mouse model of chronic cerebral hypoperfusion has been developed, which involves the narrowing of the bilateral common carotid arteries with newly designed microcoils. The purpose of this paper is to provide a comprehensive summary of the achievements made with the model that shows good reproducibility of the white matter changes characterized by blood-brain barrier disruption, glial activation, oxidative stress, and oligodendrocyte loss following chronic cerebral hypoperfusion. Detailed characterization of this model may help to decipher the substrates associated with impaired memory and move toward a more integrated therapy of vascular cognitive impairment.
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Affiliation(s)
- Masafumi Ihara
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo, Kyoto 606-8507, Japan
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Pérez-Castells J, Martín-Santamaría S, Nieto L, Ramos A, Martínez A, Pascual-Teresa BD, Jiménez-Barbero J. Structure of micelle-bound adrenomedullin: A first step toward the analysis of its interactions with receptors and small molecules. Biopolymers 2011; 97:45-53. [DOI: 10.1002/bip.21700] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 07/10/2011] [Accepted: 07/11/2011] [Indexed: 11/11/2022]
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Teramoto S, Miyamoto N, Yatomi K, Tanaka Y, Oishi H, Arai H, Hattori N, Urabe T. Exendin-4, a glucagon-like peptide-1 receptor agonist, provides neuroprotection in mice transient focal cerebral ischemia. J Cereb Blood Flow Metab 2011; 31:1696-705. [PMID: 21487412 PMCID: PMC3170947 DOI: 10.1038/jcbfm.2011.51] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone known to stimulate glucose-dependent insulin secretion. The GLP-1 receptor agonist, exendin-4, has similar properties to GLP-1 and is currently in clinical use for type 2 diabetes mellitus. As GLP-1 and exendin-4 confer cardioprotection after myocardial infarction, this study was designed to assess the neuroprotective effects of exendin-4 against cerebral ischemia-reperfusion injury. Mice received a transvenous injection of exendin-4, after a 60-minute focal cerebral ischemia. Exendin-4-treated vehicle and sham groups were evaluated for infarct volume, neurologic deficit score, various physiologic parameters, and immunohistochemical analyses at several time points after ischemia. Exendin-4 treatment significantly reduced infarct volume and improved functional deficit. It also significantly suppressed oxidative stress, inflammatory response, and cell death after reperfusion. Furthermore, intracellular cyclic AMP (cAMP) levels were slightly higher in the exendin-4 group than in the vehicle group. No serial changes were noted in insulin and glucose levels in both groups. This study suggested that exendin-4 provides neuroprotection against ischemic injury and that this action is probably mediated through increased intracellular cAMP levels. Exendin-4 is potentially useful in the treatment of acute ischemic stroke.
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Affiliation(s)
- Shinichiro Teramoto
- Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
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Oyama N, Yagita Y, Kawamura M, Sugiyama Y, Terasaki Y, Omura-Matsuoka E, Sasaki T, Kitagawa K. Cilostazol, not aspirin, reduces ischemic brain injury via endothelial protection in spontaneously hypertensive rats. Stroke 2011; 42:2571-7. [PMID: 21799161 DOI: 10.1161/strokeaha.110.609834] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE It is well-established that hypertension leads to endothelial dysfunction in the cerebral artery. Recently, cilostazol has been used for the secondary prevention of ischemic stroke. Among antiplatelet drugs, phosphodiesterase inhibitors including cilostazol have been shown to have protective effects on endothelial cells. The aim of the present study is to investigate the effects of cilostazol and aspirin on endothelial nitric oxide synthase (eNOS) phosphorylation in the cerebral cortex, endothelial function, and infarct size after brain ischemia in spontaneously hypertensive rats (SHR). METHODS Five-week-old male SHR received a 5-week regimen of chow containing 0.1% aspirin, 0.1% cilostazol, 0.3% cilostazol, or the vehicle control. The levels of total and Ser(1177)-phosphorylated eNOS protein in the cerebral cortex were evaluated by Western blot. To assess the contribution of eNOS in maintaining cerebral blood flow, we monitored cerebral blood flow by laser-Doppler flowmetry after L-N(5)-(1-iminoethyl)ornithine infusion. Additionally, we evaluated residual microperfusion using fluorescence-labeled serum protein and infarct size after transient focal brain ischemia. RESULTS In SHR, the blood pressure and heart rate were similar among the groups. Cilostazol-treated SHR had a significantly higher ratio of phospho-eNOS/total eNOS protein than vehicle-treated and aspirin-treated SHR. Treating with cilostazol, but not aspirin, significantly improved cerebral blood flow response to L-N(5)-(1-iminoethyl)ornithine. Cilostazol also increased residual perfusion of the microcirculation and reduced brain damage after ischemia compared to vehicle control and aspirin. CONCLUSIONS These findings indicate that cilostazol, but not aspirin, can attenuate ischemic brain injury by maintaining endothelial function in the cerebral cortex of SHR.
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Affiliation(s)
- Naoki Oyama
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Maki T, Ihara M, Fujita Y, Nambu T, Miyashita K, Yamada M, Washida K, Nishio K, Ito H, Harada H, Yokoi H, Arai H, Itoh H, Nakao K, Takahashi R, Tomimoto H. Angiogenic and vasoprotective effects of adrenomedullin on prevention of cognitive decline after chronic cerebral hypoperfusion in mice. Stroke 2011; 42:1122-8. [PMID: 21393586 DOI: 10.1161/strokeaha.110.603399] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE Although subcortical vascular dementia, the major subtype of vascular dementia, is caused by a disruption in white matter integrity after cerebrovascular insufficiency, no therapy has been discovered that will restore cerebral perfusion or functional cerebral vessels. Because adrenomedullin (AM) has been shown to be angiogenic and vasoprotective, the purpose of the study was to investigate whether AM may be used as a putative treatment for subcortical vascular dementia. METHODS A model of subcortical vascular dementia was reproduced in mice by placing microcoils bilaterally on the common carotid arteries. Using mice overexpressing circulating AM, we assessed the effect of AM on cerebral perfusion, cerebral angioarchitecture, oxidative stress, white matter change, cognitive function, and brain levels of cAMP, vascular endothelial growth factor, and basic fibroblast growth factor. RESULTS After bilateral common carotid artery stenosis, mice overexpressing circulating AM showed significantly faster cerebral perfusion recovery due to substantial growth of the capillaries, the circle of Willis, and the leptomeningeal anastomoses and reduced oxidative damage in vascular endothelial cells compared with wild-type mice. Vascular changes were preceded by upregulation of cAMP, vascular endothelial growth factor, and basic fibroblast growth factor. White matter damage and working memory deficits induced by bilateral common carotid artery stenosis were subsequently restored in mice overexpressing circulating AM. CONCLUSIONS These data indicate that AM promotes arteriogenesis and angiogenesis, inhibits oxidative stress, preserves white matter integrity, and prevents cognitive decline after chronic cerebral hypoperfusion. Thus, AM may serve as a strategy to tackle subcortical vascular dementia.
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Affiliation(s)
- Takakuni Maki
- Department of Neurology, Graduate School of Medicine, Kyoto University, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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Pre-treatment of adrenomedullin suppresses cerebral edema caused by transient focal cerebral ischemia in rats detected by magnetic resonance imaging. Brain Res Bull 2011; 84:69-74. [DOI: 10.1016/j.brainresbull.2010.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Revised: 11/01/2010] [Accepted: 11/03/2010] [Indexed: 11/19/2022]
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Hurtado O, Serrano J, Sobrado M, Fernández AP, Lizasoain I, Martínez-Murillo R, Moro MA, Martínez A. Lack of adrenomedullin, but not complement factor H, results in larger infarct size and more extensive brain damage in a focal ischemia model. Neuroscience 2010; 171:885-92. [PMID: 20854881 DOI: 10.1016/j.neuroscience.2010.09.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 09/08/2010] [Accepted: 09/14/2010] [Indexed: 11/25/2022]
Abstract
Adrenomedullin (AM) and its binding protein, complement factor H (FH), are expressed throughout the brain. In this study we used a brain-specific conditional knockout for AM and a complete knockout for FH to investigate the effect of these molecules on the pathophysiology of stroke. Following 48 h of middle cerebral artery permanent occlusion, there was a statistically significant infarct size increase in animals lacking AM when compared to their wild type littermates. In contrast, lack of FH did not affect infarct volume. To investigate some of the mechanisms by which lack of AM may augment brain damage, markers of nitrosative stress, apoptosis, and autophagy were studied at the mRNA and protein levels. There was a significant increase of inducible nitric oxide synthase (iNOS), matrix metalloproteinase-9 (MMP9), fractin, and Beclin-1 in the peri-infarct area of AM-deficient mice when compared to their wild type counterparts and to contralateral and sham-operated controls. These data suggest that AM exerts a neuroprotective action in the brain and that this protection may be mediated by regulation of iNOS, matrix metalloproteases, and inflammatory mediators. In the future, substances that increase AM actions in the central nervous system may be used as potential neuroprotective agents in stroke.
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Affiliation(s)
- O Hurtado
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
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