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Mavridis T, Mavridi A, Karampela E, Galanos A, Gkiokas G, Iacovidou N, Xanthos T. Sovateltide (ILR-1620) Improves Motor Function and Reduces Hyperalgesia in a Rat Model of Spinal Cord Injury. Neurocrit Care 2024:10.1007/s12028-024-01950-2. [PMID: 38443708 DOI: 10.1007/s12028-024-01950-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/26/2024] [Indexed: 03/07/2024]
Abstract
BACKGROUND Spinal cord injury (SCI) presents a major global health challenge, with rising incidence rates and substantial disability. Although progress has been made in understanding SCI's pathophysiology and early management, there is still a lack of effective treatments to mitigate long-term consequences. This study investigates the potential of sovateltide, a selective endothelin B receptor agonist, in improving clinical outcomes in an acute SCI rat model. METHODS Thirty male Sprague-Dawley rats underwent sham surgery (group A) or SCI and treated with vehicle (group B) or sovateltide (group C). Clinical tests, including Basso, Beattie, and Bresnahan scoring, inclined plane, and allodynia testing with von Frey hair, were performed at various time points. Statistical analyses assessed treatment effects. RESULTS Sovateltide administration significantly improved motor function, reducing neurological deficits and enhancing locomotor recovery compared with vehicle-treated rats, starting from day 7 post injury. Additionally, the allodynic threshold improved, suggesting antinociceptive properties. Notably, the sovateltide group demonstrated sustained recovery, and even reached preinjury performance levels, whereas the vehicle group plateaued. CONCLUSIONS This study suggests that sovateltide may offer neuroprotective effects, enhancing neurogenesis and angiogenesis. Furthermore, it may possess anti-inflammatory and antinociceptive properties. Future clinical trials are needed to validate these findings, but sovateltide shows promise as a potential therapeutic strategy to improve functional outcomes in SCI. Sovateltide, an endothelin B receptor agonist, exhibits neuroprotective properties, enhancing motor recovery and ameliorating hyperalgesia in a rat SCI model. These findings could pave the way for innovative pharmacological interventions for SCI in clinical settings.
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Affiliation(s)
- Theodoros Mavridis
- First Department of Neurology, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
- Department of Neurology, Tallaght University Hospital (TUH)/The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH), Dublin, Ireland.
| | - Artemis Mavridi
- First Department of Pediatrics, Medical School, Aghia Sophia Children's Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | | | - Antonis Galanos
- Laboratory for Research of the Musculoskeletal System, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - George Gkiokas
- Second Department of Surgery, Aretaieion University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Nicoletta Iacovidou
- Department of Neonatology, Aretaieio Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Theodoros Xanthos
- School of Health and Caring Sciences, University of West Attica, Athens, Greece
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Cuenca JP, Kang HJ, Fahad MAA, Park M, Choi M, Lee HY, Lee BT. Physico-mechanical and biological evaluation of heparin/VEGF-loaded electrospun polycaprolactone/decellularized rat aorta extracellular matrix for small-diameter vascular grafts. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2022; 33:1664-1684. [PMID: 35446751 DOI: 10.1080/09205063.2022.2069398] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Although the continuous development of small-diameter vascular grafts (SDVGs) (D < 5 mm) continues, most vascular grafts are made from synthetic polymers, which lead to serious complications from arteriosclerosis, thrombosis, and vascular ischemia. Here, to address these shortcomings, we combine synthetic polymers with natural decellularized small-diameter vessels and loaded with growth factor. We fabricated vascular grafts by electrospinning polycaprolactone (PCL) to decellularized rat aorta matrix (ECM) followed by heparin and vascular endothelial growth factor (VEGF) loading. In- vitro studies showed that PCL/ECM/VEGF vascular grafts, showed excellent hemocompatibility and biocompatibility properties. The vascular grafts implanted into the rat aorta revealed that the PCL/ECM/VEGF grafts promotes endothelial cells and smooth-muscle cells infiltration with a rate of FLK-1, ICAM1, and a-SMA distribution higher than that of the PCL and PCL/ECM vascular grafts at 2 weeks and 4 weeks after implantation. The PCL/ECM/VEGF vascular graft should be considered for potential small-diameter vascular grafts in clinical fields.
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Affiliation(s)
- John Patrick Cuenca
- Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, South Korea
| | - Hoe-Jin Kang
- Institute of Tissue Regeneration, Soonchunhyang University, Cheonan, South Korea
| | - Md Abdullah Al Fahad
- Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, South Korea
| | - Myeongki Park
- Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, South Korea
| | - Minji Choi
- Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, South Korea
| | - Hyun-Yong Lee
- Department of Surgery, Soonchunhyang University Cheonan Hospital, Cheonan, Republic of Korea
| | - Byong-Taek Lee
- Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, South Korea
- Institute of Tissue Regeneration, Soonchunhyang University, Cheonan, South Korea
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Chen KC, Song ZM, Croaker GD. Brain size reductions associated with endothelin B receptor mutation, a cause of Hirschsprung's disease. BMC Neurosci 2021; 22:42. [PMID: 34147087 PMCID: PMC8214790 DOI: 10.1186/s12868-021-00646-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 06/08/2021] [Indexed: 01/03/2023] Open
Abstract
Background ETB has been reported to regulate neurogenesis and vasoregulation in foetal development. Its dysfunction was known to cause HSCR, an aganglionic colonic disorder with syndromic forms reported to associate with both small heads and developmental delay. We therefore asked, "is CNS maldevelopment a more general feature of ETB mutation?" To investigate, we reviewed the micro-CT scans of an ETB−/− model animal, sl/sl rat, and quantitatively evaluated the structural changes of its brain constituents. Methods Eleven neonatal rats generated from ETB+/− cross breeding were sacrificed. Micro-CT scans were completed following 1.5% iodine-staining protocols. All scans were reviewed for morphological changes. Selected organs were segmented semi-automatically post-NLM filtering: TBr, T-CC, T-CP, OB, Med, Cer, Pit, and S&I Col. Volumetric measurements were made using Drishti rendering software. Rat genotyping was completed following analysis. Statistical comparisons on organ volume, organ growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control groups based on autosomal recessive inheritance. One-way ANOVA was also performed to evaluate potential dose-dependent effect. Results sl/sl rat has 16.32% lower body weight with 3.53% lower growth rate than the control group. Gross intracranial morphology was preserved in sl/sl rats. However, significant volumetric reduction of 20.33% was detected in TBr; similar reductions were extended to the measurements of T-CC, T-CP, OB, Med, and Pit. Consistently, lower brain and selected constituent growth rates were detected in sl/sl rat, ranging from 6.21% to 11.51% reduction. Lower organ volume/bodyweight ratio was detected in sl/sl rats, reflecting disproportional neural changes with respect to body size. No consistent linear relationships exist between ETB copies and intracranial organ size or growth rates. Conclusion Although ETB−/− mutant has a normal CNS morphology, significant size reductions in brain and constituents were detected. These structural changes likely arise from a combination of factors secondary to dysfunctional ET-1/ET-3/ETB signalling, including global growth impairment from HSCR-induced malnutrition and dysregulations in the neurogenesis, angiogenesis, and cerebral vascular control. These changes have important clinical implications, such as autonomic dysfunction or intellectual delay. Although further human study is warranted, our study suggested comprehensive managements are required for HSCR patients, at least in ETB−/− subtype. Supplementary Information The online version contains supplementary material available at 10.1186/s12868-021-00646-z.
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Affiliation(s)
- Ko-Chin Chen
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.
| | - Zan-Min Song
- Medical School, Australian National University, Canberra, ACT, 2601, Australia
| | - Geoffrey D Croaker
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.,The Canberra Hospital, Yamba Drive, Garran, ACT, 2605, Australia
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Michinaga S, Inoue A, Sonoda K, Mizuguchi H, Koyama Y. Down-regulation of astrocytic sonic hedgehog by activation of endothelin ET B receptors: Involvement in traumatic brain injury-induced disruption of blood brain barrier in a mouse model. Neurochem Int 2021; 146:105042. [PMID: 33838160 DOI: 10.1016/j.neuint.2021.105042] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/21/2021] [Accepted: 04/02/2021] [Indexed: 12/18/2022]
Abstract
In the adult brain, sonic hedgehog acts on cerebral microvascular endothelial cells to stabilize the blood-brain barrier. The expression of sonic hedgehog by astrocytes is altered during brain injury, and this change has been shown to affect permeability of blood-brain barrier. However, much remains unknown about the regulation of astrocytic sonic hedgehog production. Our results showed that endothelin-1 reduced sonic hedgehog mRNA expression and extracellular protein release in mouse cerebral cultured astrocytes, but had no effect in bEnd.3, a mouse brain microvascular endothelial-derived cell line. The effect of endothelin-1 on astrocyte sonic hedgehog expression was suppressed by an ETB antagonist BQ788, but was unchanged by the ETA antagonist FR139317. In cultured astrocytes and bEnd.3, endothelin-1 did not affect the expression of the sonic hedgehog receptor-related molecules, patched-1 and smoothened. In an animal model of traumatic brain injury, fluid percussion injury on the mouse cerebrum increased the expression of sonic hedgehog, patched-1, and smoothened. Repeated administration of BQ788 enhanced sonic hedgehog expression at 5 days after fluid percussion injury. Histochemical examination revealed sonic hedgehog expression in glial fibrillary acidic protein-positive astrocytes in the cerebrum after fluid percussion injury. Administration of exogenous sonic hedgehog and BQ788 suppressed Evans blue extravasation, an indicator of blood vessel permeability, induced by fluid percussion injury. The effects of BQ788 on fluid percussion injury-induced Evans blue extravasation were reduced by the administration of jervine, a sonic hedgehog inhibitor. Altogether, these results suggest that endothelin-1 down-regulates astrocytic sonic hedgehog to promote disruption of the blood-brain barrier during traumatic brain injury.
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Affiliation(s)
- Shotaro Michinaga
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Ayana Inoue
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Kyomi Sonoda
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Hiroyuki Mizuguchi
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Yutaka Koyama
- Laboratory of Pharmacology, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kita, Higashinada, Kobe, 668-8558, Japan.
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Koyama Y, Tsuboi S, Mizogui F. Endothelin-1 decreases the expression of Ephrin-A and B subtypes in cultured rat astrocytes through ET B receptors. Neurosci Lett 2021; 741:135393. [PMID: 33279571 DOI: 10.1016/j.neulet.2020.135393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/08/2020] [Accepted: 09/14/2020] [Indexed: 11/24/2022]
Abstract
Ephrin family proteins are cell surface molecules that regulate several cellular functions through cell-cell interactions. During nervous tissue repair after injury, the expression of ephrin subtypes in astrocytes is altered, affecting the axonal elongation and migration of neuronal precursors. However, the mechanism regulating the expression of ephrin subtypes in astrocytes has not been investigated. Herein, we studied the effects of endothelin-1 (ET-1) on the expression of ephrin subtypes in cultured rat astrocytes. Our results showed that ET-1 (100 nM) treatment for 1-24 h reduced the expression of ephrin-A2, -A4, -B2, and -B3 mRNA and protein in astrocytes, whereas the expression of ephrin-A1, -A3, -A5, and -B1 mRNA were not affected. Sarafotoxin S6c, a selective ETB receptor agonist, decreased the expression of ephrin-A2, -A4, -B2, and -B3 in cultured astrocytes. The decrease in ephrin-A2, -A4, -B2, and -B3 expression by ET-1 treatment was reduced in the presence of BQ788, an ETB receptor antagonist, while FR139317, an ETA receptor antagonist, had no effects. These results suggest that ET-1 is a signaling molecule that downregulates ephrin-A2, -A4, -B2, and -B3 expression in astrocytes.
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Affiliation(s)
- Yutaka Koyama
- Laboratory of Pharmacology, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kita Higashinada, Kobe 668-8558 Japan.
| | - Sayaka Tsuboi
- Laboratory of Pharmacology, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kita Higashinada, Kobe 668-8558 Japan
| | - Fuka Mizogui
- Laboratory of Pharmacology, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kita Higashinada, Kobe 668-8558 Japan
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Gulati A, Agrawal N, Vibha D, Misra UK, Paul B, Jain D, Pandian J, Borgohain R. Safety and Efficacy of Sovateltide (IRL-1620) in a Multicenter Randomized Controlled Clinical Trial in Patients with Acute Cerebral Ischemic Stroke. CNS Drugs 2021; 35:85-104. [PMID: 33428177 PMCID: PMC7872992 DOI: 10.1007/s40263-020-00783-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/05/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Sovateltide (IRL-1620, PMZ-1620), an endothelin-B receptor agonist, has been previously shown to increase cerebral blood flow, have anti-apoptotic activity and produce neurovascular remodeling when administered intravenously following acute cerebral ischemic stroke in rats. Its safety and tolerability were confirmed in healthy human volunteers (CTRI/2016/11/007509). OBJECTIVE Our objective was to determine the safety, tolerability and efficacy of sovateltide as an addition to standard of care (SOC) in patients with acute cerebral ischemic stroke. METHODS A prospective, multicentric, randomized, double-blind, placebo-controlled study was conducted to compare the safety (primary objective) and efficacy (secondary objective) of sovateltide in patients with acute cerebral ischemic stroke. Adult males or females aged 18-70 years who had experienced a radiologically confirmed ischemic stroke within the last 24 h were included in the study. Patients with intracranial hemorrhage and those receiving endovascular therapy were excluded. Patients randomized to the sovateltide group received three doses of sovateltide (each dose 0.3 µg/kg) administered as an intravenous bolus over 1 min at an interval of 3 ± 1 h on day 1, day 3 and day 6 (total dose of 0.9 µg/kg/day). Patients randomized to the placebo group received an equal volume of saline. Every patient in both groups received SOC for stroke. Efficacy was evaluated using neurological outcomes based on National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI) scores from day 1 through day 90. Quality of life was measured using the EuroQoL-5 Dimensions (EQ-5D) and Stroke-Specific Quality of Life (SSQoL) at 60 and 90 days of follow-up. RESULTS A total of 40 patients with acute cerebral ischemic stroke were enrolled in this study, of whom 36 completed the 90-day follow-up. Patients received saline (n = 18; 11 male and 7 female) or sovateltide (n = 18; 15 male and 3 female) within 24 h of onset of stroke. The number of patients receiving investigational drug within 20 h of onset of stroke was 14/18 in the saline group and 10/18 in the sovateltide group. The baseline characteristics and SOC in both cohorts was similar. Sovateltide was well-tolerated, and all patients received complete treatment with no incidence of drug-related adverse events. Hemodynamic, biochemical or hematological parameters were not affected by sovateltide. Sovateltide treatment resulted in improved mRS and BI scores on day 6 compared with day 1 (p < 0.0001), an effect not seen in the saline group. Sovateltide increased the frequency of favorable outcomes at 3 months. An improvement of ≥ 2 points on the mRS was observed in 60 and 40% of patients in the sovateltide and saline groups, respectively (p = 0.0519; odds ratio [OR] 5.25). An improvement on the BI of ≥ 40 points was seen in 64 and 36% of the sovateltide and saline groups, respectively (p = 0.0112; OR 12.44). An improvement of ≥6 points on the NIHSS was seen in 56% of patients in the sovateltide group versus 43% in the saline group (p = 0.2714; OR 2.275). The number of patients with complete recovery (defined as an NIHSS score of 0 and a BI of 100) was significantly greater (p < 0.05) in the sovateltide group than in the saline group. An assessment of complete recovery using an mRS score of 0 did not show a statistically significant difference between the treatment groups. Sovateltide treatment resulted in improved quality of life as measured by the EQ-5D and SSQoL on day 90. CONCLUSION Sovateltide was safe and well-tolerated and resulted in improved neurological outcomes in patients with acute cerebral ischemic stroke 90 days post-treatment. TRIAL REGISTRATION The study is registered at CTRI/2017/11/010654 and NCT04046484.
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Affiliation(s)
- Anil Gulati
- Pharmazz, Inc., 50 West 75th Street, Suite 105, Willowbrook, IL, 60527, USA.
- Midwestern University, Downers Grove, IL, USA.
| | | | - Deepti Vibha
- All India Inst of Medical Sciences, New Delhi, India
| | - U K Misra
- Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Michinaga S, Inoue A, Yamamoto H, Ryu R, Inoue A, Mizuguchi H, Koyama Y. Endothelin receptor antagonists alleviate blood-brain barrier disruption and cerebral edema in a mouse model of traumatic brain injury: A comparison between bosentan and ambrisentan. Neuropharmacology 2020; 175:108182. [PMID: 32561219 DOI: 10.1016/j.neuropharm.2020.108182] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/29/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) is induced by the immediate physical disruption of brain tissue. TBI causes disruption of the blood-brain barrier (BBB) and brain edema. In the cerebrospinal fluid (CSF) of TBI patients, endothelin-1 (ET-1) is increased, suggesting that ET-1 aggravates TBI-induced brain damage. In this study, the effect of bosentan (ETA/ETB antagonist) and ambrisentan (ETA antagonist) on BBB dysfunction and brain edema were examined in a mouse model of TBI using lateral fluid percussion injury (FPI). FPI to the mouse cerebrum increased the expression levels of ET-1 and ETB receptors. Administration of bosentan (3 or 15 mg/kg/day) and ambrisentan (0.1 or 0.5 mg/kg/day) at 6 and 24 h after FPI ameliorated BBB disruption and cerebral brain edema. Delayed administration of bosentan from 2 days after FPI also reduced BBB disruption and brain edema, while ambrisentan had no significant effects. FPI-induced expression levels of ET-1 and ETB receptors were reduced by bosentan, but not by ambrisentan. In cultured mouse astrocytes and brain microvessel endothelial cells, ET-1 (100 nM) increased prepro--ET-1 mRNA, which was inhibited by bosentan, but not by ambrisentan. FPI-induced alterations of the expression levels of matrix metalloproteinase-9, vascular endothelial growth factor-A, and angiopoietin-1 in the mouse cerebrum were reduced by delayed administration of bosentan, while ambrisentan had no significant effects. These results suggest that ET antagonists are effective in improving BBB disruption and cerebral edema in TBI patients and that an ETA/ETB non-selective type of antagonists is more effective.
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Affiliation(s)
- Shotaro Michinaga
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Anna Inoue
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Hayato Yamamoto
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Ryotaro Ryu
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Ayana Inoue
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Hiroyuki Mizuguchi
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tondabayashi, Osaka, 584-8540, Japan
| | - Yutaka Koyama
- Laboratory of Pharmacology, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kita Higashinada, Kobe, 668-8558, Japan.
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Michinaga S, Kimura A, Hatanaka S, Minami S, Asano A, Ikushima Y, Matsui S, Toriyama Y, Fujii M, Koyama Y. Delayed Administration of BQ788, an ET B Antagonist, after Experimental Traumatic Brain Injury Promotes Recovery of Blood-Brain Barrier Function and a Reduction of Cerebral Edema in Mice. J Neurotrauma 2018; 35:1481-1494. [PMID: 29316834 DOI: 10.1089/neu.2017.5421] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is induced by immediate physical disruption of brain tissue, and causes death and disability. Studies on experimental TBI animal models show that disruption of the blood-brain barrier (BBB) underlies brain edema and neuroinflammation during the delayed phase of TBI. In neurological disorders, endothelin-1 (ET-1) is involved in BBB dysfunction and brain edema. In this study, the effect of ET antagonists on BBB dysfunction and brain edema were examined in a mouse focal TBI model using lateral fluid percussion injury (FPI). ET-1 and ETB receptors were increased at 2-7 days after FPI, which was accompanied by extravasation of Evans blue (EB) and brain edema. Repeated intracerebroventricular administration of BQ788 (15 nmol/day), an ETB antagonist, from 2 days after FPI promoted recovery of EB extravasation and brain edema, while FR 139317, an ETA antagonist, had no effect. Delayed intravenous administration of BQ788 also promoted recovery from FPI-induced EB extravasation and brain edema. While FPI caused decreases in claudin-5, occludin, and zonula occludens-1 proteins, BQ788 reversed FPI-induced reductions of them. Immunohistochemical observation of the cerebrum after FPI showed that ETB receptors are predominantly expressed in glial fibrillary acidic protein (GFAP)-positive astrocytes. BQ788 reduced FPI-induced increases in GFAP-positive astrocytes. GFAP-positive astrocytes produced vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP9). FPI-induced increases in VEGF-A and MMP-9 production were reversed by BQ788. These results suggest that ETB receptor antagonism during the delayed phase of focal TBI promotes recovery of BBB function and reduction of brain edema.
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Affiliation(s)
- Shotaro Michinaga
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Akimasa Kimura
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Shunichi Hatanaka
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Shizuho Minami
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Arisa Asano
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Yuki Ikushima
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Shingo Matsui
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Yoshiya Toriyama
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Manami Fujii
- 1 Laboratory of Pharmacology, Osaka Ohtani University , Osaka, Japan
| | - Yutaka Koyama
- 2 Department of Pharmacology, Kobe Pharmaceutical University , Kobe, Japan
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Koyama Y, Ukita A, Abe K, Iwamae K, Tokuyama S, Tanaka K, Kotake Y. Dexamethasone Downregulates Endothelin Receptors and Reduces Endothelin-Induced Production of Matrix Metalloproteinases in Cultured Rat Astrocytes. Mol Pharmacol 2017; 92:57-66. [PMID: 28461586 DOI: 10.1124/mol.116.107300] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 04/25/2017] [Indexed: 12/31/2022] Open
Abstract
In brain disorders, astrocytes change phenotype to reactive astrocytes and are involved in the induction of neuroinflammation and brain edema. The administration of glucocorticoids (GCs), such as dexamethasone (Dex), reduces astrocytic activation, but the mechanisms underlying this inhibitory action are not well understood. Endothelins (ETs) promote astrocytic activation. Therefore, the effects of Dex on ET receptor expressions were examined in cultured rat astrocytes. Treatment with 300 nM Dex for 6-48 hours reduced the mRNA expression of astrocytic ETA and ETB receptors to 30-40% of nontreated cells. Levels of ETA and ETB receptor proteins became about 50% of nontreated cells after Dex treatment. Astrocytic ETA and ETB receptor mRNAs were decreased by 300 nM hydrocortisone. The effects of Dex and hydrocortisone on astrocytic ET receptors were abolished in the presence of mifepristone, a GC receptor antagonist. Although Dex did not decrease the basal levels of matrix metalloproteinase (MMP) 3 and MMP9 mRNAs, pretreatment with Dex reduced ET-induced increases in MMP mRNAs. The effects of ET-1 on the release of MMP3 and MMP9 proteins were attenuated by pretreatment with Dex. ET-1 stimulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in cultured astrocytes. Pretreatment with Dex reduced the ET-induced increases in ERK1/2 phosphorylation. In contrast, pretreatment with Dex did not affect MMP production or ERK1/2 phosphorylation induced by phorbol myristate acetate, a protein kinase C activator. These results indicate that Dex downregulates astrocytic ET receptors and reduces ET-induced MMP production.
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Affiliation(s)
- Yutaka Koyama
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Ayano Ukita
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Kana Abe
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Kuniaki Iwamae
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Shogo Tokuyama
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Keisuke Tanaka
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
| | - Yuki Kotake
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan (Y.Koy., A.U., K.A., K.I., K.T., Y.Kot.); and Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, Minatojima, Kobe, Japan (S.T.)
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Michinaga S, Seno N, Fuka M, Yamamoto Y, Minami S, Kimura A, Hatanaka S, Nagase M, Matsuyama E, Yamanaka D, Koyama Y. Improvement of cold injury-induced mouse brain edema by endothelin ETBantagonists is accompanied by decreases in matrixmetalloproteinase 9 and vascular endothelial growth factor-A. Eur J Neurosci 2015; 42:2356-70. [DOI: 10.1111/ejn.13020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 01/08/2023]
Affiliation(s)
- Shotaro Michinaga
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Naoki Seno
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Mayu Fuka
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Yui Yamamoto
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Shizuho Minami
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Akimasa Kimura
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Shunichi Hatanaka
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Marina Nagase
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Emi Matsuyama
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Daisuke Yamanaka
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
| | - Yutaka Koyama
- Laboratory of Pharmacology; Faculty of Pharmacy; Osaka Ohtani University; 3-11-1 Nishikiori-Kita, Tonda-bayashi Osaka 584-8540 Japan
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11
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Pathogenesis of brain edema and investigation into anti-edema drugs. Int J Mol Sci 2015; 16:9949-75. [PMID: 25941935 PMCID: PMC4463627 DOI: 10.3390/ijms16059949] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/15/2015] [Accepted: 04/27/2015] [Indexed: 12/18/2022] Open
Abstract
Brain edema is a potentially fatal pathological state that occurs after brain injuries such as stroke and head trauma. In the edematous brain, excess accumulation of extracellular fluid results in elevation of intracranial pressure, leading to impaired nerve function. Despite the seriousness of brain edema, only symptomatic treatments to remove edema fluid are currently available. Thus, the development of novel anti-edema drugs is required. The pathogenesis of brain edema is classified as vasogenic or cytotoxic edema. Vasogenic edema is defined as extracellular accumulation of fluid resulting from disruption of the blood-brain barrier (BBB) and extravasations of serum proteins, while cytotoxic edema is characterized by cell swelling caused by intracellular accumulation of fluid. Various experimental animal models are often used to investigate mechanisms underlying brain edema. Many soluble factors and functional molecules have been confirmed to induce BBB disruption or cell swelling and drugs targeted to these factors are expected to have anti-edema effects. In this review, we discuss the mechanisms and involvement of factors that induce brain edema formation, and the possibility of anti-edema drugs targeting them.
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12
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Koyama Y, Michinaga S. [Roles of astroglia in the regulations of brain vascular permeability]. Nihon Yakurigaku Zasshi 2014; 144:115-119. [PMID: 25213611 DOI: 10.1254/fpj.144.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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13
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Koyama Y, Hayashi M, Nagae R, Tokuyama S, Konishi T. Endothelin-1 increases the expression of VEGF-R1/Flt-1 receptors in rat cultured astrocytes through ETB receptors. J Neurochem 2014; 130:759-69. [PMID: 24862165 DOI: 10.1111/jnc.12770] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/04/2023]
Abstract
Expressions of vascular endothelial growth factor (VEGF) receptors in astrocytes are increased in damaged brains. To clarify the regulatory mechanisms of VEGF receptors, the effects of endothelin-1 (ET-1) were examined in rat cultured astrocytes. Expressions of VEGF-R1 and -R2 receptor mRNA were at similar levels, whereas the mRNA expressions of VEGF-R3 and Tie-2, a receptor for angiopoietins, were lower. Placenta growth factor, a selective agonist of the VEGF-R1 receptor, induced phosphorylation of focal adhesion kinase (FAK) and extracellular signal regulated kinase 1/2 (ERK1/2). Phosphorylations of FAK and ERK 1/2 were also stimulated by VEGF-E, a selective VEGF-R2 agonist. Increased phosphorylations of FAK and ERK1/2 by VEGF165 were reduced by selective antagonists for VEGF-R1 and -R2. Treatment with ET-1 increased VEGF-R1 mRNA and protein levels. The effects of ET-1 on VEGF-R1 mRNA were mimicked by Ala(1,3,11,15) -ET-1, a selective agonist for ETB receptors, and inhibited by BQ788, an ETB antagonist. ET-1 did not affect the mRNA levels of VEGF-R2, -R3, and Tie-2. Pre-treatment with ET-1 potentiated the effects of placenta growth factor on phosphorylations of FAK and ERK1/2. These findings suggest that ET-1 induces up-regulation of VEGF-R1 receptors in astrocytes, and potentiates VEGF signals in damaged nerve tissues. To clarify the regulatory mechanisms of vascular endothelial growth factor (VEGF) receptors, the effects of endothelin-1 (ET-1) were examined in rat cultured astrocytes. Effects of selective VEGF-R1 and R2 agonist showed that these receptors were linked to focal adhesion kinase (FAK) and extracellular signal regulated kinase 1/2 (ERK1/2). Treatment with ET-1 increased expression of VEGF-R1, which was mediated by ETB receptors. Pre-treatment with ET-1 potentiated the VEGF-R1-mediated activations of FAK and ERK1/2. These findings suggest that ET-1 induces up-regulation of VEGF-R1 receptors in astrocytes.
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Affiliation(s)
- Yutaka Koyama
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Osaka, Japan
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14
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Michinaga S, Nagase M, Matsuyama E, Yamanaka D, Seno N, Fuka M, Yamamoto Y, Koyama Y. Amelioration of cold injury-induced cortical brain edema formation by selective endothelin ETB receptor antagonists in mice. PLoS One 2014; 9:e102009. [PMID: 25000290 PMCID: PMC4084986 DOI: 10.1371/journal.pone.0102009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/13/2014] [Indexed: 12/13/2022] Open
Abstract
Brain edema is a potentially fatal pathological condition that often occurs in stroke and head trauma. Following brain insults, endothelins (ETs) are increased and promote several pathophysiological responses. This study examined the effects of ETB antagonists on brain edema formation and disruption of the blood-brain barrier in a mouse cold injury model (Five- to six-week-old male ddY mice). Cold injury increased the water content of the injured cerebrum, and promoted extravasation of both Evans blue and endogenous albumin. In the injury area, expression of prepro-ET-1 mRNA and ET-1 peptide increased. Intracerebroventricular (ICV) administration of BQ788 (ETB antagonist), IRL-2500 (ETB antagonist), or FR139317 (ETA antagonist) prior to cold injury significantly attenuated the increase in brain water content. Bolus administration of BQ788, IRL-2500, or FR139317 also inhibited the cold injury-induced extravasation of Evans blue and albumin. Repeated administration of BQ788 and IRL-2500 beginning at 24 h after cold injury attenuated both the increase in brain water content and extravasation of markers. In contrast, FR139317 had no effect on edema formation when administrated after cold injury. Cold injury stimulated induction of glial fibrillary acidic protein-positive reactive astrocytes in the injured cerebrum. Induction of reactive astrocytes after cold injury was attenuated by ICV administration of BQ788 or IRL-2500. These results suggest that ETB receptor antagonists may be an effective approach to ameliorate brain edema formation following brain insults.
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Affiliation(s)
- Shotaro Michinaga
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Marina Nagase
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Emi Matsuyama
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Daisuke Yamanaka
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Naoki Seno
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Mayu Fuka
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Yui Yamamoto
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
| | - Yutaka Koyama
- Laboratory of Pharmacology, Faculty of Pharmacy, Osaka Ohtani University, Tonda-bayashi, Osaka, Japan
- * E-mail:
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15
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Leonard MG, Gulati A. Endothelin B receptor agonist, IRL-1620, enhances angiogenesis and neurogenesis following cerebral ischemia in rats. Brain Res 2013; 1528:28-41. [DOI: 10.1016/j.brainres.2013.07.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 06/21/2013] [Accepted: 07/03/2013] [Indexed: 11/24/2022]
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16
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Koyama Y, Maebara Y, Hayashi M, Nagae R, Tokuyama S, Michinaga S. Endothelins reciprocally regulate VEGF-A and angiopoietin-1 production in cultured rat astrocytes: implications on astrocytic proliferation. Glia 2012; 60:1954-63. [PMID: 22927341 DOI: 10.1002/glia.22411] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 07/11/2012] [Accepted: 07/31/2012] [Indexed: 11/07/2022]
Abstract
Vascular endothelial growth factors (VEGFs) and angiopoietins (ANGs) are involved in pathophysiological responses in damaged nerve tissues. Astrocytes produce VEGFs and ANGs upon brain ischemia and traumatic injury. To clarify the extracellular signals regulating VEGF and ANG production, effects of endothelins (ETs), a family of endothelium-derived peptides, were examined in cultured rat astrocytes. ET-1 (100 nM) and Ala(1,3,11,15)-ET-1 (100 nM), an ET(B) receptor agonist, increased VEGF-A mRNA levels in cultured astrocytes, while ANG-1 mRNA was decreased by ETs. ET-1 did not affect astrocytic VEGF-B, placental growth factor (PLGF), and ANG-2 mRNA levels. The effects of ET-1 on VEGF-A and ANG-1 mRNAs were inhibited by BQ788, an ET(B) antagonist. Release of VEGF-A proteins from cultured astrocytes was increased by ET-1. In contrast, ET-1 reduced release of astrocytic ANG-1. Exogenous ET-1 (100 nM) and VEGF(165) (100 ng/mL), an isopeptide of VEGF-A, stimulated bromodeoxyuridine (BrdU) incorporation into cultured astrocytes. Treatment with ET-1 and VEGF(165) increased the numbers of cyclin D1-positive astrocytes. Exogenous ANG-1 (250 ng/mL) did not stimulate the BrdU incorporation. Increases in BrdU incorporation by ET-1 and VEGF(165) were not affected by ANG-1. In 60-70% confluent cultures, SU4312 (10 μM), a VEGF receptor tyrosine kinase inhibitor, partially reduced the effects of ET-1 on BrdU incorporation and cyclin D1 expression. ET-induced BrdU incorporation and cyclin D1 expression were reduced by a neutralizing antibody against VEGF-A. Our findings suggest that ET-1 is a factor regulating astrocytic VEGF-A and ANG-1, and that increased VEGF-A production potentiates ET-induced astrocytic proliferation by an autocrine mechanism.
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Affiliation(s)
- Yutaka Koyama
- Faculty of Pharmacy, Laboratory of Pharmacology, Osaka Ohtani University, 3-11-1 Nishikiori-Kita, Tonda-bayashi, Osaka, Japan.
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17
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Leonard MG, Briyal S, Gulati A. Endothelin B receptor agonist, IRL-1620, provides long-term neuroprotection in cerebral ischemia in rats. Brain Res 2012; 1464:14-23. [PMID: 22580085 DOI: 10.1016/j.brainres.2012.05.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/10/2012] [Accepted: 05/03/2012] [Indexed: 12/21/2022]
Abstract
We have earlier shown that stimulation of endothelin B receptors by IRL-1620 provides significant neuroprotection at 24h following cerebral ischemia. However, the effect of IRL-1620 is not known in the subacute phase of cerebral ischemia, where development of cerebral edema further contributes towards brain damage. This study was designed to determine the effect of IRL-1620 on neurological functions, infarct volume, oxidative stress, and endothelin receptors following permanent middle cerebral artery occlusion for 7 days. Rats received three intravenous injections of either vehicle or IRL-1620 [Suc-[Glu9,Ala11,15]-Endothelin-1(8-12)] at 2, 4, and 6h post occlusion. Treatment with IRL-1620 reduced infarct volume (54.06 ± 14.12 mm(3) vs. 177.06 ± 13.21 mm(3)), prevented cerebral edema and significantly improved all neurological and motor function parameters when compared to the vehicle-treated group. Vehicle-treated middle cerebral artery occluded rats demonstrated high levels of malondialdehyde and low levels of reduced glutathione and superoxide dismutase; these effects were reversed in IRL-1620 treated rats. No change in expression of endothelin A receptor was observed 7 days after induction of cerebral ischemia in vehicle or IRL-1620 treated rats. Rats receiving IRL-1620 demonstrated an upregulation of endothelin B receptor only in the infarcted hemisphere 7 days following occlusion. All effects of IRL-1620 were blocked by endothelin B receptor antagonist, BQ788. Results of the present study demonstrate that IRL-1620, administered on day 1, provides significant neuroprotection till 7 days after the induction of cerebral ischemia in rats. Selective endothelin B receptor activation may prove to be a novel therapeutic target in the treatment of cerebral ischemia.
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Affiliation(s)
- Mary G Leonard
- Midwestern University Chicago College of Pharmacy, Downers Grove, IL 60515, USA
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18
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Wuestefeld R, Chen J, Meller K, Brand-Saberi B, Theiss C. Impact of vegf on astrocytes: analysis of gap junctional intercellular communication, proliferation, and motility. Glia 2012; 60:936-47. [PMID: 22431192 DOI: 10.1002/glia.22325] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 02/16/2012] [Indexed: 12/12/2022]
Abstract
The purpose of the present study was to investigate the effects of vascular endothelial growth factor (VEGF) on gap junctional intercellular communication (GJIC), cell proliferation, and cell dynamics in primary astrocytes. VEGF is known as a dimeric polypeptide that potentially binds to two receptors, VEGFR-1 and VEGFR-2, however many effects are mediated by VEGFR-2, for example, actin polymerization, forced cell migration, angiogenesis, and cell proliferation. Recently it has been shown that in case of hypoxia, ischemia or injury VEGF is upregulated to stimulate angiogenesis and cell proliferation. Besides this, VEGF reveals a potent therapeutical target for averting tumor vascularization, emerging in bevacizumab, the first humanized anti-VEGF-A antibody for treating recurrent Glioblastoma multiforme. To expand our knowledge about VEGF effects in glial cells, we cultivated rat astrocytes in medium containing VEGF for 1 and 2 days. To investigate the effects of VEGF on GJIC, we microinjected neurobiotin into a single cell and monitored dye-spreading into adjacent cells. These experiments showed that VEGF significantly enhances astrocytic GJIC compared with controls. Cell proliferation measured by BrdU-labeling also revealed a significant increase of astrocytic mitose rates subsequent to 1 day of VEGF exposure, whereas longer VEGF treatment for 2 days did not have additive effects. To study cell-dynamics of astrocytes subsequent to VEGF treatment, we additionally transfected astrocytes with LifeAct-RFP. Live-cell imaging and quantitative analysis of these cells with aid of confocal laser scanning microscopy revealed higher process movement of VEGF-treated astrocytes. In conclusion, VEGF strongly affects cell proliferation, GJIC, and motility in astrocytes.
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Affiliation(s)
- Ricarda Wuestefeld
- Institute of Anatomy and Molecular Embryology, Ruhr-University Bochum, Bochum, Germany
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Koyama Y, Michinaga S. Regulations of Astrocytic Functions by Endothelins: Roles in the Pathophysiological Responses of Damaged Brains. J Pharmacol Sci 2012; 118:401-7. [DOI: 10.1254/jphs.11r13cp] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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