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Mogi M, Liu S, Watanabe R, Imai M, Yano A, Ikegawa Y, Kato H. Perspectives on frailty as a total life-course disease with consideration of the fetal environment. Geriatr Gerontol Int 2023; 23:263-269. [PMID: 36855031 DOI: 10.1111/ggi.14565] [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: 08/26/2022] [Revised: 01/08/2023] [Accepted: 02/06/2023] [Indexed: 03/02/2023]
Abstract
Frailty attracts research as it represents a significant target for intervention to extend the healthy life span. An unanswered question in this field is the time point during the life-course at which an individual becomes predisposed to frailty. Here, we propose that frailty has a fetal origin and should be regarded as part of the spectrum of the developmental origins of health and disease. The developmental origins of health and disease theory originated from findings linking the fetal environment to lifestyle-related disorders such as hypertension and diabetes. Coincidentally, a recent trend in frailty research also centers on vascular dysfunction and metabolic alterations as the causality of lifestyle-related disorders such as sarcopenia and dementia. Here, we explore the relationship between fetal programming, frailty-related disorders (sarcopenia and dementia), and other age-related diseases mainly based on reports on intrauterine growth restriction. We propose a "total" life-course approach to combat frailty. With this viewpoint, not only physicians and gerontologists but also obstetricians and pediatricians should team up to overcome age-related diseases in the elderly. Geriatr Gerontol Int 2023; ••: ••-••.
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Affiliation(s)
- Masaki Mogi
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan
| | - Shuang Liu
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan
| | - Ryusuke Watanabe
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan.,Department of Pediatrics, Graduate School of Medicine, Ehime University, Tohon, Japan
| | - Matome Imai
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan.,Department of Obstetrics and Gynecology, Ehime University, Graduate School of Medicine, Tohon, Japan
| | - Akiko Yano
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan.,Department of Obstetrics and Gynecology, Ehime University, Graduate School of Medicine, Tohon, Japan
| | - Yasuhito Ikegawa
- Department of Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Japan.,Department of Ophthalmology, Ehime University, Graduate School of Medicine, Tohon, Japan
| | - Hidemasa Kato
- Department of Developmental Biology and Functional Genomics, Ehime University, Graduate School of Medicine, Tohon, Japan
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2
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Jones I, Hägglund AC, Carlsson L. Reduced mTORC1-signaling in retinal ganglion cells leads to vascular retinopathy. Dev Dyn 2021; 251:321-335. [PMID: 34148274 DOI: 10.1002/dvdy.389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The coordinated wiring of neurons, glia and endothelial cells into neurovascular units is critical for central nervous system development. This is best exemplified in the mammalian retina where interneurons, astrocytes and retinal ganglion cells sculpt their vascular environment to meet the metabolic demands of visual function. Identifying the molecular networks that underlie neurovascular unit formation is an important step towards a deeper understanding of nervous system development and function. RESULTS Here, we report that cell-to-cell mTORC1-signaling is essential for neurovascular unit formation during mouse retinal development. Using a conditional knockout approach we demonstrate that reduced mTORC1 activity in asymmetrically positioned retinal ganglion cells induces a delay in postnatal vascular network formation in addition to the production of rudimentary and tortuous vessel networks in adult animals. The severity of this vascular phenotype is directly correlated to the degree of mTORC1 down regulation within the neighboring retinal ganglion cell population. CONCLUSIONS This study establishes a cell nonautonomous role for mTORC1-signaling during retinal development. These findings contribute to our current understanding of neurovascular unit formation and demonstrate how ganglion cells actively sculpt their local environment to ensure that the retina is perfused with an appropriate supply of oxygen and nutrients.
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Affiliation(s)
- Iwan Jones
- Umeå Center for Molecular Medicine (UCMM), Umeå University, Umeå, Sweden
| | | | - Leif Carlsson
- Umeå Center for Molecular Medicine (UCMM), Umeå University, Umeå, Sweden
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3
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Morita A, Yoshizumi M, Arima S, Mori A, Sakamoto K, Nagamitsu T, Nakahara T. Pharmacological depletion of retinal neurons prevents vertical angiogenic sprouting without affecting the superficial vascular plexus. Dev Dyn 2021; 250:497-512. [PMID: 33085163 DOI: 10.1002/dvdy.263] [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: 04/09/2020] [Revised: 09/29/2020] [Accepted: 10/12/2020] [Indexed: 02/27/2024] Open
Abstract
BACKGROUND In mice, a tri-layered (superficial, intermediate, and deep) vascular structure is formed in the retina during the third postnatal week. Short-term treatment of newborn mice with vascular endothelial growth factor (VEGF) receptor inhibitors delays the formation of superficial vascular plexus and this allows us to investigate the developmental process of superficial and deep vascular plexuses at the same time. Using this model, we examined the effect of pharmacological depletion of retinal neurons on the formation of superficial and deep vascular plexuses. RESULTS Neuronal cell loss induced by an intravitreal injection of N-methyl-d-aspartic acid on postnatal day (P) 8 delayed vascular development in the deep layer but not in the superficial layer in mice treated with KRN633, a VEGF receptor inhibitor, on P0 and P1. In KRN633-treated mice, neuronal cell loss decreased the number of vertical sprouts originating from the superficial plexus without affecting the number of angiogenic sprouts growing in front. Neuronal cell loss did not impair networks of fibronectin and astrocytes in the superficial layer. CONCLUSIONS Our results suggest that inner retinal neurons play a crucial role in forming the deep vascular plexus by directing the sprouts from the superficial blood vessels to the deep layer.
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Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Mika Yoshizumi
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Shiho Arima
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Tohru Nagamitsu
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, Tokyo, Japan
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4
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Kondo R, Nakano A, Asano D, Morita A, Arima S, Mori A, Sakamoto K, Nagamitsu T, Nakahara T. Abnormal Vascular Phenotypes Associated with the Timing of Interruption of Retinal Vascular Development in Rats. Biol Pharm Bull 2021; 43:859-863. [PMID: 32378561 DOI: 10.1248/bpb.b19-01065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pathological angiogenesis is a leading cause of blindness in several retinal diseases. The key driving factor inducing pathological angiogenesis is the pronounced hypoxia leading to a marked, increased production of vascular endothelial growth factor (VEGF). The aim of this study was to determine whether the abnormal vascular growth occurs in a manner dependent on the degree of the vascular defects. Vascular defects of two different degrees were created in the retina by subcutaneously treating neonatal rats with the VEGF receptor (VEGFR) tyrosine kinase inhibitor KRN633 on postnatal day (P) 4 and P5 (P4/5) or P7 and P8 (P7/8). The structure of the retinal vasculature changes was examined immunohistochemically. Prevention of vascular growth and regression of some preformed capillaries were observed on the next day, after completion of each treatment (i.e., P6 and P9). The vascular regrowth occurred as a result of eliminating the inhibitory effect on the VEGFR signaling pathway. KRN633 (P4/5)-treated rats exhibited a retinal vasculature with aggressive intravitreal neovascularization on P21. On the other hand, the appearance of tortuous arteries is a representative vascular pathological feature in retinas of KRN633 (P7/8)-treated groups. These results suggest that an interruption of the retinal vascular development at different time points induces different vascular pathological features in the retina. Pharmacological agents targeting the VEGF signaling pathway are useful for creating an abnormal retinal vasculature with various pathological features in order to evaluate the efficacy of anti-angiogenic compounds.
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Affiliation(s)
- Ryo Kondo
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Ayuki Nakano
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Daiki Asano
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Shiho Arima
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Tohru Nagamitsu
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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5
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Morita A, Goko T, Matsumura M, Asaso D, Arima S, Mori A, Sakamoto K, Nagamitsu T, Nakahara T. The process of revascularization in the neonatal mouse retina following short-term blockade of vascular endothelial growth factor receptors. Cell Tissue Res 2020; 382:529-549. [PMID: 32897421 DOI: 10.1007/s00441-020-03276-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 08/07/2020] [Indexed: 01/24/2023]
Abstract
Misdirected vascular growth frequently occurs in the neovascular diseases in the retina. However, the mechanisms are still not fully understood. In the present study, we created capillary-free zones in the central and peripheral retinas in neonatal mice by pharmacological blockade of vascular endothelial growth factor (VEGF) signaling. Using this model, we investigated the process and mechanisms of revascularization in the central and peripheral avascular areas. After the completion of a 2-day treatment with the VEGF receptor tyrosine kinase inhibitor KRN633 on postnatal day (P) 4 and P5, revascularization started on P8 in the central avascular area where capillaries had been dropped out. The expression levels of VEGF were higher in the peripheral than in the central avascular area. However, the expansion of the vasculature in the peripheral avascular retina remained suppressed until revascularization had been completed in the central avascular area. Additionally, we found disorganized endothelial cell division, misdirected blood vessels with irregular diameters, and abnormal fibronectin networks at the border of the vascular front and the avascular retina. In the central avascular area, a slight amount of fibronectin as non-vascular component re-formed to provide a scaffold for revascularization. Mechanistic analysis revealed that higher levels of VEGF attenuated the migratory response of endothelial cells without decreasing the proliferative activity. These results suggest that the presence of concentration range of VEGF, which enhances both migration and proliferation of the endothelial cells, and the structurally normal fibronectin network contribute to determine the proper direction of angiogenesis.
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Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Tomomi Goko
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Mami Matsumura
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Daiki Asaso
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Shiho Arima
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
- Laboratory of Medical Pharmacology, Department of Clinical & Pharmaceutical Sciences, Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
- Laboratory of Medical Pharmacology, Department of Clinical & Pharmaceutical Sciences, Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Tohru Nagamitsu
- Department of Organic Synthesis, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
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6
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Nakahara T, Morita A, Yagasaki R, Mori A, Sakamoto K. Mammalian Target of Rapamycin (mTOR) as a Potential Therapeutic Target in Pathological Ocular Angiogenesis. Biol Pharm Bull 2018; 40:2045-2049. [PMID: 29199229 DOI: 10.1248/bpb.b17-00475] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pathological ocular angiogenesis is a causative factor of retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. Vascular endothelial growth factor (VEGF) plays an important role in pathological angiogenesis, and anti-VEGF agents have been used to treat the ocular diseases that are driven by pathological angiogenesis. However, adverse effects associated with the blockade of VEGF signaling, including impairments of normal retinal vascular growth and retinal function, were suggested. Therefore, the development of a safe, effective strategy to prevent pathological ocular angiogenesis is needed. Recent studies have demonstrated that inhibitors of the mammalian target of rapamycin (mTOR) target proliferating endothelial cells within the retinal vasculature. Here, we review the potential of targeting the mTOR pathway to treat pathological ocular angiogenesis.
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Affiliation(s)
- Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Rina Yagasaki
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
| | - Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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7
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Morita A, Sawada S, Mori A, Arima S, Sakamoto K, Nagamitsu T, Nakahara T. Establishment of an abnormal vascular patterning model in the mouse retina. J Pharmacol Sci 2018; 136:177-188. [DOI: 10.1016/j.jphs.2018.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/21/2017] [Accepted: 10/25/2017] [Indexed: 01/19/2023] Open
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8
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Nakano A, Asano D, Kondo R, Mori A, Arima S, Ushikubo H, Sakamoto K, Nagamitsu T, Ishii K, Nakahara T. Retinal neuronal cell loss prevents abnormal retinal vascular growth in a rat model of retinopathy of prematurity. Exp Eye Res 2018; 168:115-127. [DOI: 10.1016/j.exer.2017.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 12/06/2017] [Accepted: 12/21/2017] [Indexed: 11/29/2022]
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9
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Morita A, Mori A, Arima S, Sakamoto K, Nagamitsu T, Ishii K, Nakahara T. Transient phenotypic changes in endothelial cells and pericytes in neonatal mouse retina following short-term blockade of vascular endothelial growth factor receptors. Dev Dyn 2018; 247:699-711. [DOI: 10.1002/dvdy.24614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/23/2017] [Accepted: 12/04/2017] [Indexed: 12/27/2022] Open
Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Asami Mori
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Shiho Arima
- Department of Organic Synthesis; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Tohru Nagamitsu
- Department of Organic Synthesis; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Kunio Ishii
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Tokyo Japan
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10
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A delay in vascularization induces abnormal astrocyte proliferation and migration in the mouse retina. Dev Dyn 2017; 246:186-200. [DOI: 10.1002/dvdy.24484] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/09/2016] [Accepted: 12/16/2016] [Indexed: 12/23/2022] Open
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11
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Morita A, Ushikubo H, Mori A, Sakamoto K, Nakahara T. Exposure to high-concentration oxygen in the neonatal period induces abnormal retinal vascular patterning in mice. ACTA ACUST UNITED AC 2016; 107:216-224. [DOI: 10.1002/bdrb.21187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 09/19/2016] [Accepted: 10/06/2016] [Indexed: 01/27/2023]
Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Minato-ku Tokyo Japan
| | - Hiroko Ushikubo
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Minato-ku Tokyo Japan
| | - Asami Mori
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Minato-ku Tokyo Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Minato-ku Tokyo Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology; Kitasato University School of Pharmaceutical Sciences; Minato-ku Tokyo Japan
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12
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Retinal region-dependent susceptibility of capillaries to high-concentration oxygen exposure and vascular endothelial growth factor receptor inhibition in neonatal mice. J Pharmacol Sci 2015; 129:107-18. [PMID: 26403253 DOI: 10.1016/j.jphs.2015.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 01/08/2023] Open
Abstract
Retinal blood flow insufficiency due to capillary loss induces hypoxia in the retina, leading to an abnormal angiogenesis, relating to ischemic retinopathy. To better understand the mechanism and process of retinal capillary regression, we examined the process of hyperoxia- and vascular endothelial growth factor receptor (VEGFR) inhibitor-induced retinal capillary regression in neonatal mice. We also investigated the effects of Ca(2+) channel blockers, amlodipine and nicardipine, on hyperoxia-induced capillary regression. The regression of capillaries adjacent to arteries began immediately after the mice were exposed to 80% oxygen on postnatal day 7. An apparent avascular zone was established within 24 h after the initiation of oxygen exposure, whereas capillaries in the retinal vascular front were not affected. Axitinib, an inhibitor of VEGFR tyrosine kinase, induced capillary regression throughout the retinal vasculature. High-concentration oxygen exposure affected the capillaries on the arterial side of the retinal circulation more preferentially than axitinib. The Ca(2+) channel blockers significantly delayed hyperoxia-induced capillary regression and changes in the capillaries on the arterial side. These results suggest that the decreased blood flow due to arterial constriction contributes to hyperoxia-induced capillary regression. Compounds that improve the retinal blood flow may prevent ischemia by preventing capillary loss.
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13
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Morita A, Nakahara T, Ushikubo H, Mori A, Sakamoto K, Ishii K. Treatment of newborn mice with inhibitors of vascular endothelial growth factor receptor tyrosine kinase induces abnormal retinal vascular patterning. Biol Pharm Bull 2015; 37:1986-9. [PMID: 25451848 DOI: 10.1248/bpb.b14-00540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously reported that treatment of newborn mice with KRN633, a vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor, delayed retinal vascularization leading to abnormal retinal vascular growth and patterns. To determine whether similar abnormalities are observed in newborn mice treated with other VEGF receptor tyrosine kinase inhibitors, we administered axitinib to mice on the day of birth and on the following day. When compared with control pups, a significant delay in retinal vascularization was observed in pups treated with axitinib (5 mg/kg). Axitinib-treated pups had a very dense capillary network on postnatal day (P) 6 and fewer central arteries and veins on P8 and P12. Central veins, but not arteries, were significantly enlarged on P8. These abnormalities were similar to those observed in KRN633-treated pups and probably represent a common phenotype induced by short-term treatment with VEGF receptor inhibitors in newborn mice. Therefore, mice treated postnatally with VEGFR inhibitors could serve as an animal model for studying the mechanisms of retinal vascular formation and patterning.
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Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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14
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Yagasaki R, Nakahara T, Ushikubo H, Mori A, Sakamoto K, Ishii K. Anti-angiogenic effects of mammalian target of rapamycin inhibitors in a mouse model of oxygen-induced retinopathy. Biol Pharm Bull 2015; 37:1838-42. [PMID: 25366488 DOI: 10.1248/bpb.b14-00487] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ocular pathologic angiogenesis is a causative factor for retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration. In the present study, we examined the effects of rapamycin and everolimus, inhibitors of mammalian target of rapamycin (mTOR), on retinal pathologic angiogenesis in mice with oxygen-induced retinopathy (OIR), an animal model of proliferative ischemic retinopathy. Mice were exposed to 80% oxygen from postnatal day (P) 7 to P10, and were then brought into room air and subcutaneously injected with rapamycin and everolimus. The neovascular tufts, the size of the central avascular zone, and the immunoreactivity for phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTOR activity, were evaluated in flat-mounted retinas. Retinal neovascular tufts and vascular growth in the avascular zone were observed in P15 mice with OIR. In addition, intense immunoreactivity for pS6 was detected in the neovascular tufts and in endothelial cells located at the vascular-avascular border. Both rapamycin and everolimus reduced the extent of retinal neovascular tufts and pS6 immunoreactivity, but they also increased the size of the avascular zone. Thus, activation of the mTOR pathway in endothelial cells contributes to retinal pathologic angiogenesis, and mTOR inhibitors that target proliferating endothelial cells are promising candidates as anti-angiogenic agents for the treatment of vasoproliferative retinal diseases.
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Affiliation(s)
- Rina Yagasaki
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences
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15
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Yagasaki R, Nakahara T, Mori A, Sakamoto K, Ishii K. Effects of mTOR inhibition on normal retinal vascular development in the mouse. Exp Eye Res 2014; 129:127-34. [PMID: 25446323 DOI: 10.1016/j.exer.2014.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/29/2014] [Accepted: 11/07/2014] [Indexed: 12/24/2022]
Abstract
We aimed to determine the role of age-related changes in the mammalian target of rapamycin (mTOR) activity in endothelial cell growth during retinal vascular development in mice. Mice were administered the mTOR inhibitor rapamycin as follows: (i) for 6 days from postnatal day 0 (P0) to P5, (ii) for 2 days on P6 and P7, and (iii) for 2 days on P12 and P13. For comparison, we examined the effects of KRN633, an inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinase, on retinal vascular development. The retinal vasculature and phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTOR activity, were evaluated using immunohistochemistry. Vascularization was delayed and capillary density was reduced in mice administered rapamycin from P0 to P5 compared to the vehicle-treated mice. Rapamycin administration on P6 and P7 decreased the vascular density but did not significantly delay the radial vascular growth. Rapamycin administration on P12 and P13 did not significantly affect the retinal superficial blood vessels. Immunoreactivity for pS6 was detected in both endothelial cells in the vascular front and non-vascular cells in the retinal parenchyma, and rapamycin markedly diminished the pS6 immunoreactivity. KRN633 administration on P0 and P1 completely inhibited retinal vascularization. The effects of KRN633 on retinal blood vessels decreased in magnitude in an age-dependent manner. These results suggest that the mTOR pathway in endothelial cells activated by VEGF contributes to physiologic vascular development, and that the mTOR pathway in endothelial cells is modulated in a postnatal age-dependent manner.
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Affiliation(s)
- Rina Yagasaki
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
| | - Asami Mori
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kunio Ishii
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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16
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Morita A, Nakahara T, Abe N, Kurauchi Y, Mori A, Sakamoto K, Nagamitsu T, Ishii K. Treatment of Mid-Pregnant Mice with KRN633, an Inhibitor of Vascular Endothelial Growth Factor Receptor Tyrosine Kinase, Induces Abnormal Retinal Vascular Patterning in Their Newborn Pups. ACTA ACUST UNITED AC 2014; 101:293-9. [DOI: 10.1002/bdrb.21112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/14/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Akane Morita
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Naomichi Abe
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Yuki Kurauchi
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Asami Mori
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Kenji Sakamoto
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
| | - Tohru Nagamitsu
- Department of Organic Synthesis; Kitasato University School of Pharmaceutical Sciences; Shirokane, Minato-ku Tokyo Japan
| | - Kunio Ishii
- Department of Molecular Pharmacology; Shirokane, Minato-ku Tokyo Japan
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