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Zhang J, Zhou H, Cai Y, Yoshida S, Li Y, Zhou Y. Melatonin: Unveiling the functions and implications in ocular health. Pharmacol Res 2024; 205:107253. [PMID: 38862072 DOI: 10.1016/j.phrs.2024.107253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/13/2024]
Abstract
Melatonin, a versatile hormone produced by the pineal gland, has garnered considerable scientific interest due to its diverse functions. In the eye, melatonin regulates a variety of key processes like inhibiting angiogenesis by reducing vascular endothelial growth factor levels and protecting the blood-retinal barrier (BRB) integrity by enhancing tight junction proteins and pericyte coverage. Melatonin also maintains cell health by modulating autophagy via the Sirt1/mTOR pathways, reduces inflammation, promotes antioxidant enzyme activity, and regulates intraocular pressure fluctuations. Additionally, melatonin protects retinal ganglion cells by modulating aging and inflammatory pathways. Understanding melatonin's multifaceted functions in ocular health could expand the knowledge of ocular pathogenesis, and shed new light on therapeutic approaches in ocular diseases. In this review, we summarize the current evidence of ocular functions and therapeutic potential of melatonin and describe its roles in angiogenesis, BRB integrity maintenance, and modulation of various eye diseases, which leads to a conclusion that melatonin holds promising treatment potential for a wide range of ocular health conditions.
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Affiliation(s)
- Ji Zhang
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011, China
| | - Haixiang Zhou
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011, China
| | - Yuting Cai
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011, China
| | - Shigeo Yoshida
- Department of Ophthalmology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Yun Li
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011, China.
| | - Yedi Zhou
- Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan 410011, China.
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2
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Ma C, Li H, Lu S, Li X. The Role and Therapeutic Potential of Melatonin in Degenerative Fundus Diseases: Diabetes Retinopathy and Age-Related Macular Degeneration. Drug Des Devel Ther 2024; 18:2329-2346. [PMID: 38911030 PMCID: PMC11193467 DOI: 10.2147/dddt.s471525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 06/13/2024] [Indexed: 06/25/2024] Open
Abstract
Degenerative fundus disease encompasses a spectrum of ocular diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), which are major contributors to visual impairment and blindness worldwide. The development and implementation of effective strategies for managing and preventing the onset and progression of these diseases are crucial for preserving patients' visual acuity. Melatonin, a neurohormone primarily produced by the pineal gland, exhibits properties such as circadian rhythm modulation, antioxidant activity, anti-inflammatory effects, and neuroprotection within the ocular environment. Furthermore, melatonin has been shown to suppress neovascularization and reduce vascular leakage, both of which are critical in the pathogenesis of degenerative fundus lesions. Consequently, melatonin emerges as a promising therapeutic candidate for degenerative ocular diseases. This review provides a comprehensive overview of melatonin synthesis, its localization within ocular tissues, and its mechanisms of action, particularly in regulating melatonin production, thereby underscoring its potential as a therapeutic agent for degenerative fundus diseases.
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Affiliation(s)
- Chao Ma
- Department of Ophthalmology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People’s Republic of China
| | - Haoyu Li
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China
- Hunan Clinical Research Centre of Ophthalmic Disease, Changsha, Hunan, People’s Republic of China
| | - Shuwen Lu
- Department of Ophthalmology, the First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, Henan, People’s Republic of China
| | - Xian Li
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Simonson M, Li Y, Zhu B, McAnany JJ, Chirakalwasan N, Sutabutr Vajaranant T, Hanlon EC, Pannain S, Anothaisintawee T, Reutrakul S. Multidimensional sleep health and diabetic retinopathy: Systematic review and meta-analysis. Sleep Med Rev 2024; 74:101891. [PMID: 38118339 PMCID: PMC10963161 DOI: 10.1016/j.smrv.2023.101891] [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: 09/07/2023] [Revised: 11/24/2023] [Accepted: 12/04/2023] [Indexed: 12/22/2023]
Abstract
Diabetic retinopathy (DR) is one of the most prevalent microvascular diabetic complications. Poor sleep health and obstructive sleep apnea (OSA) are risk factors for diabetes and poor glycemic control. Recent studies have suggested associations between poor sleep health/OSA and DR. Furthermore, there have been suggestions of melatonin dysregulation in the context of DR. We conducted a systematic review and meta-analysis exploring the associations between multidimensional sleep health (duration, satisfaction, efficiency, timing/regularity and alertness), OSA and melatonin with DR. Forty-two studies were included. Long, but not short sleep, was significantly associated with DR, OR 1.41 (95%CI 1.21, 1.64). Poor sleep satisfaction was also significantly associated with DR, OR 2.04 (1.41, 2.94). Sleep efficiency and alertness were not associated with DR, while the evidence on timing/regularity was scant. Having OSA was significantly associated with having DR, OR 1.34 (1.07, 1.69). Further, those with DR had significantly lower melatonin/melatonin metabolite levels than those without DR, standardized mean difference -0.94 (-1.44, -0.44). We explored whether treating OSA with continuous positive airway pressure (CPAP) led to improvement in DR (five studies). The results were mixed among studies, but potential benefits were observed in some. This review highlights the association between poor multidimensional sleep health and DR.
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Affiliation(s)
- Matthew Simonson
- College of Medicine, University of Illinois Chicago, Chicago, IL, USA
| | - Yanliang Li
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL, USA
| | - Bingqian Zhu
- School of Nursing, Shanghai Jiao Tong University, Shanghai, China
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL, USA
| | - Naricha Chirakalwasan
- Excellence Center for Sleep Disorders, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Thailand; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | | | - Erin C Hanlon
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, USA
| | - Silvana Pannain
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, USA
| | - Thunyarat Anothaisintawee
- Department of Clinical Epidemiology and Biostatistics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
| | - Sirimon Reutrakul
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois Chicago, Chicago, IL, USA; Department of Biobehavioral Nursing Science, College of Nursing, University of Illinois, Chicago, USA.
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4
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Li J, Chen K, Li X, Zhang X, Zhang L, Yang Q, Xia Y, Xie C, Wang X, Tong J, Shen Y. Mechanistic insights into the alterations and regulation of the AKT signaling pathway in diabetic retinopathy. Cell Death Discov 2023; 9:418. [PMID: 37978169 PMCID: PMC10656479 DOI: 10.1038/s41420-023-01717-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 11/05/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023] Open
Abstract
In the early stages of diabetic retinopathy (DR), diabetes-related hyperglycemia directly inhibits the AKT signaling pathway by increasing oxidative stress or inhibiting growth factor expression, which leads to retinal cell apoptosis, nerve proliferation and fundus microvascular disease. However, due to compensatory vascular hyperplasia in the late stage of DR, the vascular endothelial growth factor (VEGF)/phosphatidylinositol 3 kinase (PI3K)/AKT cascade is activated, resulting in opposite levels of AKT regulation compared with the early stage. Studies have shown that many factors, including insulin, insulin-like growth factor-1 (IGF-1), VEGF and others, can regulate the AKT pathway. Disruption of the insulin pathway decreases AKT activation. IGF-1 downregulation decreases the activation of AKT in DR, which abrogates the neuroprotective effect, upregulates VEGF expression and thus induces neovascularization. Although inhibiting VEGF is the main treatment for neovascularization in DR, excessive inhibition may lead to apoptosis in inner retinal neurons. AKT pathway substrates, including mammalian target of rapamycin (mTOR), forkhead box O (FOXO), glycogen synthase kinase-3 (GSK-3)/nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa-B (NF-κB), are a research focus. mTOR inhibitors can delay or prevent retinal microangiopathy, whereas low mTOR activity can decrease retinal protein synthesis. Inactivated AKT fails to inhibit FOXO and thus causes apoptosis. The GSK-3/Nrf2 cascade regulates oxidation and inflammation in DR. NF-κB is activated in diabetic retinas and is involved in inflammation and apoptosis. Many pathways or vital activities, such as the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and mitogen-activated protein kinase (MAPK) signaling pathways, interact with the AKT pathway to influence DR development. Numerous regulatory methods can simultaneously impact the AKT pathway and other pathways, and it is essential to consider both the connections and interactions between these pathways. In this review, we summarize changes in the AKT signaling pathway in DR and targeted drugs based on these potential sites.
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Affiliation(s)
- Jiayuan Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Kuangqi Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiang Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xuhong Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Liyue Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Qianjie Yang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Yutong Xia
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Chen Xie
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiawei Wang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianping Tong
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
| | - Ye Shen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
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Liu WJ, Chen JY, Niu SR, Zheng YS, Lin S, Hong Y. Recent advances in the study of circadian rhythm disorders that induce diabetic retinopathy. Biomed Pharmacother 2023; 166:115368. [PMID: 37647688 DOI: 10.1016/j.biopha.2023.115368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 08/18/2023] [Accepted: 08/22/2023] [Indexed: 09/01/2023] Open
Abstract
Diabetic retinopathy (DR) is a severe microvascular complication of diabetes mellitus and a major cause of blindness in young adults. Multiple potential factors influence DR; however, the exact mechanisms are poorly understood. Advanced treatments for DR, including laser therapy, vitrectomy, and intraocular drug injections, slow the disease's progression but fail to cure or reverse visual impairment. Therefore, additional effective methods to prevent and treat DR are required. The biological clock plays a crucial role in maintaining balance in the circadian rhythm of the body. Poor lifestyle habits, such as irregular routines and high-fat diets, may disrupt central and limbic circadian rhythms. Disrupted circadian rhythms can result in altered glucose metabolism and obesity. Misaligned central and peripheral clocks lead to a disorder of the rhythm of glucose metabolism, and chronically high sugar levels lead to the development of DR. We observed a disturbance in clock function in patients with diabetes, and a misaligned clock could accelerate the development of DR. In the current study, we examine the relationship between circadian rhythm disorders, diabetes, and DR. We conclude that: 1) abnormal function of the central clock and peripheral clock leads to abnormal glucose metabolism, further causing DR and 2) diabetes causes abnormal circadian rhythms, further exacerbating DR. Thus, our study presents new insights into the prevention and treatment of DR.
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Affiliation(s)
- Wen-Jing Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China
| | - Jie-Yu Chen
- Department of Ophthalmology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China
| | - Si-Ru Niu
- Department of Ophthalmology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China
| | - Yi-Sha Zheng
- Department of Ophthalmology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China
| | - Shu Lin
- Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Group of Neuroendocrinology, Garvan Institute of Medical Research, 384 Victoria St, Sydney, Australia.
| | - Yu Hong
- Department of Ophthalmology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China; Centre of Neurological and Metabolic Research, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province 362000, China.
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Romeo A, Bonaccorso A, Carbone C, Lupo G, Daniela Anfuso C, Giurdanella G, Caggia C, Randazzo C, Russo N, Romano GL, Bucolo C, Rizzo M, Tosi G, Thomas Duskey J, Ruozi B, Pignatello R, Musumeci T. Melatonin loaded hybrid nanomedicine: DoE approach, optimization and in vitro study on diabetic retinopathy model. Int J Pharm 2022; 627:122195. [PMID: 36115466 DOI: 10.1016/j.ijpharm.2022.122195] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 09/03/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022]
Abstract
Melatonin (MEL) is a pleiotropic neurohormone of increasing interest as a neuroprotective agent in ocular diseases. Improving the mucoadhesiveness is a proposed strategy to increase the bioavailability of topical formulations. Herein, the design and optimization of MEL-loaded lipid-polymer hybrid nanoparticles (mel-LPHNs) using Design of Experiment (DoE) was performed. LPHNs consisted of PLGA-PEG polymer nanoparticles coated with a cationic lipid-shell. The optimized nanomedicine showed suitable size for ophthalmic administration (189.4 nm; PDI 0.260) with a positive surface charge (+39.8 mV), high encapsulation efficiency (79.8 %), suitable pH and osmolarity values, good mucoadhesive properties and a controlled release profile. Differential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy confirmed the encapsulation of melatonin in the systems and the interaction between lipids and polymer matrix. Biological evaluation in an in vitro model of diabetic retinopathy demonstrated enhanced neuroprotective and antioxidant activities of mel-LPHNs, compared to melatonin aqueous solution at the same concentration (0.1 and 1 μM). A modified Draize test was performed to assess the ocular tolerability of the formulation showing no signs of irritation. To the best our knowledge, this study reported for the first time the development of mel-LPHNs, a novel and safe hybrid platform suitable for the topical management of retinal diseases.
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Affiliation(s)
- Alessia Romeo
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy.
| | - Angela Bonaccorso
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy; Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Claudia Carbone
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy; Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Gabriella Lupo
- Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Carmelina Daniela Anfuso
- Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Giovanni Giurdanella
- Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Cinzia Caggia
- NANO-i, Research Centre for Ocular Nanotechnology, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; Department of Agriculture, Food and Environment (Di3A), University of Catania, Via S. Sofia 100, 95123 Catania, Italy.
| | - Cinzia Randazzo
- NANO-i, Research Centre for Ocular Nanotechnology, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; Department of Agriculture, Food and Environment (Di3A), University of Catania, Via S. Sofia 100, 95123 Catania, Italy.
| | - Nunziatina Russo
- Department of Agriculture, Food and Environment (Di3A), University of Catania, Via S. Sofia 100, 95123 Catania, Italy.
| | - Giovanni Luca Romano
- Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Claudio Bucolo
- Department of Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 97, 95123 Catania, Italy.
| | - Milena Rizzo
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy.
| | - Giovanni Tosi
- Department of Life Sciences, Nanotech Lab, Te.Far.T.I., University of Modena & Reggio Emilia, Via Campi 103, Modena 41125, Italy.
| | - Jason Thomas Duskey
- Department of Life Sciences, Nanotech Lab, Te.Far.T.I., University of Modena & Reggio Emilia, Via Campi 103, Modena 41125, Italy.
| | - Barbara Ruozi
- Department of Life Sciences, Nanotech Lab, Te.Far.T.I., University of Modena & Reggio Emilia, Via Campi 103, Modena 41125, Italy.
| | - Rosario Pignatello
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy; NANO-i, Research Centre for Ocular Nanotechnology, University of Catania, Viale A. Doria 6, 95125 Catania, Italy.
| | - Teresa Musumeci
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria, 6 - 95125 Catania, Italy; NANO-i, Research Centre for Ocular Nanotechnology, University of Catania, Viale A. Doria 6, 95125 Catania, Italy.
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Chevillard PM, Batailler M, Piégu B, Estienne A, Blache MC, Dubois JP, Pillon D, Vaudin P, Dupont J, Just N, Migaud M. Seasonal vascular plasticity in the mediobasal hypothalamus of the adult ewe. Histochem Cell Biol 2022; 157:581-593. [PMID: 35118552 DOI: 10.1007/s00418-022-02079-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Sheep, like most seasonal mammals, exhibit a cyclic adaptive reproductive physiology that allows ewes to give birth to their progeny during the spring when environmental conditions are favorable to their survival. This process relies on the detection of day length (or photoperiod) and is associated with profound changes in cellular plasticity and gene expression in the hypothalamic-pituitary-gonadal axis, mechanisms that are suggested to participate in the seasonal adaptation of neuroendocrine circuits. Recently, pituitary vascular growth has been proposed as a seasonally regulated process in which the vascular endothelial growth factor A (VEGFA), a well-known angiogenic cytokine, is suspected to play a crucial role. However, whether this mechanism is restricted to the pituitary gland or also occurs in the mediobasal hypothalamus (MBH), a crucial contributor to the control of the reproductive function, remains unexplored. Using newly developed image analysis tools, we showed that the arcuate nucleus (ARH) of the MBH exhibits an enhanced vascular density during the long photoperiod or non-breeding season, associated with higher expression of VEGFA. In the median eminence (ME), a structure connecting the MBH to the pituitary gland, higher VEGFA, kinase insert domain receptor (KDR/VEGFR2) and plasmalemma vesicle-associated protein (PLVAP) gene expressions were detected during the long photoperiod. We also found that VEGFA and its receptor, VEGFR2, are expressed by neurons and tanycytes in both the ARH and ME. Altogether, these data show variations in the MBH vasculature according to seasons potentially through a VEGFA-dependent pathway, paving the way for future studies aiming to decipher the role of these changes in the hypothalamic control of seasonal reproduction.
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Affiliation(s)
- Pierre-Marie Chevillard
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Martine Batailler
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Benoît Piégu
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Anthony Estienne
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Marie-Claire Blache
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Jean-Philippe Dubois
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Delphine Pillon
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Pascal Vaudin
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Joëlle Dupont
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Nathalie Just
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Martine Migaud
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France.
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8
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Oliveira-Abreu K, Cipolla-Neto J, Leal-Cardoso JH. Effects of Melatonin on Diabetic Neuropathy and Retinopathy. Int J Mol Sci 2021; 23:100. [PMID: 35008523 PMCID: PMC8744787 DOI: 10.3390/ijms23010100] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 12/18/2022] Open
Abstract
Diabetes mellitus (DM) leads to complications, the majority of which are nephropathy, retinopathy, and neuropathy. Redox imbalance and inflammation are important components of the pathophysiology of these complications. Many studies have been conducted to find a specific treatment for these neural complications, and some of them have investigated the therapeutic potential of melatonin (MEL), an anti-inflammatory agent and powerful antioxidant. In the present article, we review studies published over the past 21 years on the therapeutic efficacy of MEL in the treatment of DM-induced neural complications. Reports suggest that there is a real prospect of using MEL as an adjuvant treatment for hypoglycemic agents. However, analysis shows that there is a wide range of approaches regarding the doses used, duration of treatment, and treatment times in relation to the temporal course of DM. This wide range hinders an objective analysis of advances and prospective vision of the paths to be followed for the unequivocal establishment of parameters to be used in an eventual therapeutic validation of MEL in neural complications of DM.
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Affiliation(s)
- Klausen Oliveira-Abreu
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil;
| | - José Cipolla-Neto
- Laboratório de Neurobiologia, Instituto de Ciências Biomédicas 1, Universidade de São Paulo, Sao Paulo 05508-000, SP, Brazil;
| | - Jose Henrique Leal-Cardoso
- Laboratório de Eletrofisiologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza 60714-903, CE, Brazil;
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9
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Tu Y, Song E, Wang Z, Ji N, Zhu L, Wang K, Sun H, Zhang Y, Zhu Q, Liu X, Zhu M. Melatonin attenuates oxidative stress and inflammation of Müller cells in diabetic retinopathy via activating the Sirt1 pathway. Biomed Pharmacother 2021; 137:111274. [PMID: 33517190 DOI: 10.1016/j.biopha.2021.111274] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/06/2020] [Accepted: 12/26/2020] [Indexed: 01/09/2023] Open
Abstract
Oxidative stress and inflammation are important pathogenic factors of diabetic retinopathy (DR). DR remains the most common ocular complication caused by diabetes mellitus (DM) and is the leading cause of visual impairment in working-aged people worldwide. Melatonin has attracted extensive attention due to its potent antioxidant and anti-inflammatory effects. In the present study, melatonin inhibited oxidative stress and inflammation by enhancing the expression and activity of silent information regulator factor 2-related enzyme 1 (Sirt1) both in in vitro and in vivo models of DR, and the Sirt1 inhibitor EX-527 counteracted melatonin-mediated antioxidant and anti-inflammatory effects on Müller cells. Moreover, melatonin enhanced Sirt1 activity through the maternally expressed gene 3 (MEG3)/miR-204 axis, leading to the deacetylation of the Sirt1 target genes forkhead box o1 (Foxo1) and nuclear factor kappa B (NF-κB) subunit p65, eventually contribute to the alleviation of oxidative stress and inflammation. The study revealed that melatonin promotes the Sirt1 pathway, thereby protecting the retina from DM-induced damage.
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Affiliation(s)
- Yuanyuan Tu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - E Song
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Zhenzhen Wang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Na Ji
- Department of Ophthalmology, The Affiliated Eye Hospital of Suzhou Vocational Health College, Suzhou, Jiangsu, China
| | - Linling Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Kun Wang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Haotian Sun
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Yuting Zhang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Qiujian Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China
| | - Xiaojuan Liu
- Department of Pathogen Biology, Medical College, Nantong University, Nantong, China.
| | - Manhui Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, China.
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10
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A Topical Formulation of Melatoninergic Compounds Exerts Strong Hypotensive and Neuroprotective Effects in a Rat Model of Hypertensive Glaucoma. Int J Mol Sci 2020; 21:ijms21239267. [PMID: 33291737 PMCID: PMC7730513 DOI: 10.3390/ijms21239267] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/23/2020] [Accepted: 12/02/2020] [Indexed: 02/08/2023] Open
Abstract
Melatonin is of great importance for regulating several eye processes, including pressure homeostasis. Melatonin in combination with agomelatine has been recently reported to reduce intraocular pressure (IOP) with higher efficacy than each compound alone. Here, we used the methylcellulose (MCE) rat model of hypertensive glaucoma, an optic neuropathy characterized by the apoptotic death of retinal ganglion cells (RGCs), to evaluate the hypotensive and neuroprotective efficacy of an eye drop nanomicellar formulation containing melatonin/agomelatine. Eye tissue distribution of melatonin/agomelatine in healthy rats was evaluated by HPLC/MS/MS. In the MCE model, we assessed by tonometry the hypotensive efficacy of melatonin/agomelatine. Neuroprotection was revealed by electroretinography; by levels of inflammatory and apoptotic markers; and by RGC density. The effects of melatonin/agomelatine were compared with those of timolol (a beta blocker with prevalent hypotensive activity) or brimonidine (an alpha 2 adrenergic agonist with potential neuroprotective efficacy), two drugs commonly used to treat glaucoma. Both melatonin and agomelatine penetrate the posterior segment of the eye. In the MCE model, IOP elevation was drastically reduced by melatonin/agomelatine with higher efficacy than that of timolol or brimonidine. Concomitantly, gliosis-related inflammation and the Bax-associated apoptosis were partially prevented, thus leading to RGC survival and recovered retinal dysfunction. We suggest that topical melatoninergic compounds might be beneficial for ocular health.
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11
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Bhatwadekar AD, Rameswara V. Circadian rhythms in diabetic retinopathy: an overview of pathogenesis and investigational drugs. Expert Opin Investig Drugs 2020; 29:1431-1442. [PMID: 33107770 DOI: 10.1080/13543784.2020.1842872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Circadian rhythm is a natural endogenous process occurring roughly every 24 hours. Circadian rhythm dysfunction is involved in diabetic retinopathy (DR) pathogenesis. Interestingly, there are investigational drugs that exhibit potential in the treatment of DR by targeting circadian rhythm dysfunction. AREAS COVERED We performed a literature search in June 2020 using PubMed's Medical Subject Heading (MeSH) terms 'circadian clock,' 'circadian rhythms,' and 'diabetic retinopathy.' This article offers an overview of the physiology of the biological clock and clock regulatory genes and presents an examination of the retinal clock. It discusses the pathogenic mechanisms of DR and emphasizes how circadian rhythm dysfunction at structural, physiological, metabolic and cellular levels, plays a critical role in the development of DR. The latter part of the paper sheds light on those investigational drugs (such as melatonin, tasimelteon and metformin) which exhibit potential in the treatment of DR by the targeting of circadian rhythm dysfunction. EXPERT OPINION An enhanced understanding of circadian rhythm and its role in DR could offer therapeutic potential by targeting of circadian rhythm dysfunction.
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Affiliation(s)
- Ashay D Bhatwadekar
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute , Indianapolis, IN, USA
| | - Varun Rameswara
- Indiana University School of Medicine. Indiana University , Indianapolis, IN, USA
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12
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Morris DR, Bounds SE, Liu H, Ding WQ, Chen Y, Liu Y, Cai J. Exosomal MiRNA Transfer between Retinal Microglia and RPE. Int J Mol Sci 2020; 21:ijms21103541. [PMID: 32429541 PMCID: PMC7279010 DOI: 10.3390/ijms21103541] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/10/2020] [Accepted: 05/14/2020] [Indexed: 12/16/2022] Open
Abstract
The retinal pigment epithelium (RPE), the outermost layer of the retina, provides essential support to both the neural retina and choroid. Additionally, the RPE is highly active in modulating functions of immune cells such as microglia, which migrate to the subretinal compartment during aging and age-related degeneration. Recently, studies have highlighted the important roles of microRNA (miRNA) in the coordination of general tissue maintenance as well as in chronic inflammatory conditions. In this study, we analyzed the miRNA profiles in extracellular vesicles (EVs) released by the RPE, and identified and validated miRNA species whose expression levels showed age-dependent changes in the EVs. Using co-culture of RPE and retinal microglia, we further demonstrated that miR-21 was transferred between the two types of cells, and the increased miR-21 in microglia influenced the expression of genes downstream of the p53 pathway. These findings suggest that exosome-mediated miRNA transfer is a signaling mechanism that contributes to the regulation of microglia function in the aging retina.
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Affiliation(s)
- Dorothea R. Morris
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; (D.R.M.); (Y.C.)
| | - Sarah E. Bounds
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.E.B.); (H.L.)
| | - Huanhuan Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.E.B.); (H.L.)
| | - Wei-Qun Ding
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - Yan Chen
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; (D.R.M.); (Y.C.)
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yin Liu
- Department of Neurobiology and Anatomy, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Correspondence: (Y.L.); (J.C.); Tel.: +1-713-500-5632 (Y.L.); +1-405-271-2226 (J.C.)
| | - Jiyang Cai
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; (D.R.M.); (Y.C.)
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.E.B.); (H.L.)
- Correspondence: (Y.L.); (J.C.); Tel.: +1-713-500-5632 (Y.L.); +1-405-271-2226 (J.C.)
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13
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Mirza-Aghazadeh-Attari M, Reiter RJ, Rikhtegar R, Jalili J, Hajalioghli P, Mihanfar A, Majidinia M, Yousefi B. Melatonin: An atypical hormone with major functions in the regulation of angiogenesis. IUBMB Life 2020; 72:1560-1584. [PMID: 32329956 DOI: 10.1002/iub.2287] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 03/10/2020] [Accepted: 03/26/2020] [Indexed: 02/06/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a pleotropic molecule with a wide distribution, has received considerable attention in recent years, mostly because of its various major effects on tissues or cells since it has both receptor-dependent and receptor-independent actions over a wide range of concentrations. These biological and physiological functions of melatonin include regulation of circadian rhythms by modulating the expression of core oscillator genes, scavenging the reactive oxygen species and reactive nitrogen species, modulating the immune system and inflammatory response, and exerting cytoprotective and antiapoptotic effects. Given the multiple critical roles of melatonin, dysregulation of its production or any disruption in signaling through its receptors may have contributed in the development of a wide range of disorders including type 2 diabetes, aging, immune-mediated diseases, hypertension, and cancer. Herein, we focus on the modulatory effects of melatonin on angiogenesis and its implications as a therapeutic strategy in cancer and related diseases.
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Affiliation(s)
- Mohammad Mirza-Aghazadeh-Attari
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.,Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Reza Rikhtegar
- Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Javad Jalili
- Radiology Department, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Parisa Hajalioghli
- Radiology Department, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ainaz Mihanfar
- Solid Tumor Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Maryam Majidinia
- Solid Tumor Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Bahman Yousefi
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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14
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Tu Y, Zhu M, Wang Z, Wang K, Chen L, Liu W, Shi Q, Zhao Q, Sun Y, Wang X, Song E, Liu X. Melatonin inhibits Müller cell activation and pro-inflammatory cytokine production via upregulating the MEG3/miR-204/Sirt1 axis in experimental diabetic retinopathy. J Cell Physiol 2020; 235:8724-8735. [PMID: 32324260 DOI: 10.1002/jcp.29716] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 03/17/2020] [Accepted: 04/02/2020] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy (DR) is the most common ocular complication caused by diabetes mellitus and is the main cause of visual impairment in working-age people. Reactive gliosis and pro-inflammatory cytokine production by Müller cells contribute to the progression of DR. Melatonin is a strong anti-inflammatory hormone, mediating the cytoprotective effect of a variety of retinal cells against hyperglycemia. In this study, melatonin inhibited the gliosis activation and inflammatory cytokine production of Müller cells in both in vitro and in vivo models of DR. The melatonin membrane blocker, Luzindole, invalidated the melatonin-mediated protective effect on Müller cells. Furthermore, melatonin inhibited Müller cell activation and pro-inflammatory cytokine production by upregulating the long noncoding RNA maternally expressed gene 3/miR-204/sirtuin 1 axis. In conclusion, our study suggested that melatonin treatment could be a novel therapeutic strategy for DR.
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Affiliation(s)
- Yuanyuan Tu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Manhui Zhu
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China.,Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu, China
| | - Zhenzhen Wang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Kun Wang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Lili Chen
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Wangrui Liu
- Department of Neurosurgery, Affiliated Hospital of Youjiang Medical College for Nationalities, Guangxi, China
| | - Qin Shi
- Jinqiao Clinic, Shanghai Pudong New Area Public Benefit Hospital, Shanghai, China
| | - Qingliang Zhao
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yake Sun
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xiaoyu Wang
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - E Song
- Department of Ophthalmology, Lixiang Eye Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xiaojuan Liu
- Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu, China
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15
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Pourhanifeh MH, Hosseinzadeh A, Dehdashtian E, Hemati K, Mehrzadi S. Melatonin: new insights on its therapeutic properties in diabetic complications. Diabetol Metab Syndr 2020; 12:30. [PMID: 32280378 PMCID: PMC7140344 DOI: 10.1186/s13098-020-00537-z] [Citation(s) in RCA: 47] [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] [Received: 01/03/2020] [Accepted: 03/27/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetes and diabetic complications are considered as leading causes of both morbidity and mortality in the world. Unfortunately, routine medical treatments used for affected patients possess undesirable side effects, including kidney and liver damages as well as gastrointestinal adverse reactions. Therefore, exploring the novel therapeutic strategies for diabetic patients is a crucial issue. It has been recently shown that melatonin, as main product of the pineal gland, despite its various pharmacological features including anticancer, anti-aging, antioxidant and anti-inflammatory effects, exerts anti-diabetic properties through regulating various cellular mechanisms. The aim of the present review is to describe potential roles of melatonin in the treatment of diabetes and its complications.
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Affiliation(s)
| | - Azam Hosseinzadeh
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ehsan Dehdashtian
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Karim Hemati
- Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran
| | - Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
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16
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Ma Q, Reiter RJ, Chen Y. Role of melatonin in controlling angiogenesis under physiological and pathological conditions. Angiogenesis 2019; 23:91-104. [PMID: 31650428 DOI: 10.1007/s10456-019-09689-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/09/2019] [Indexed: 02/07/2023]
Abstract
Angiogenesis depends on proangiogenic and anti-angiogenic molecules that regulate endothelial cell proliferation and migration. Well-regulated angiogenesis plays a pivotal role in many physiological conditions such as reproduction and embryonic development, while abnormal angiogenesis is also the basis of a variety of pathological processes including tumor metastasis and atherosclerotic plaque formation. Melatonin has a variety of biological effects, including inhibition of tumor metastasis, stabilizing atherosclerotic plaques, and the regulation of seasonal reproductive rhythms, etc. During certain pathophysiological processes, melatonin exerts different functions depending on its ability to regulate angiogenesis. This review reveals that melatonin has different effects on neovascularization under different physiological and pathological conditions. In tumors, in age-related ocular diseases, and in a hypoxic environment, melatonin inhibits neovascularization in tissues, while in gastric ulcers, skin lesions, and some physiologic processes, it promotes angiogenesis. We also speculate that melatonin may inhibit the neovascularization in atherosclerotic plaques, thus preventing the initiation and development of atherosclerosis. Most studies suggest that these effects are related to the role of melatonin in regulating of vascular endothelial growth factor and its receptors, but the specific regulatory mechanisms remain disparate, which may lead to the differential effects of melatonin on angiogenesis under different conditions. In this review, we thus summarize some seemingly contradictory mechanisms by which melatonin controls angiogenesis under different pathological and physiological conditions, and urge that the regulatory mechanisms be further studied.
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Affiliation(s)
- Qiang Ma
- Department of Cardiology, Chinese PLA General Hospital, Beijing, 100853, China.,Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, Texas, 78229, USA
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, Texas, 78229, USA.
| | - Yundai Chen
- Department of Cardiology, Chinese PLA General Hospital, Beijing, 100853, China.
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17
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Doğanlar ZB, Güçlü H, Öztopuz Ö, Türkön H, Dogan A, Uzun M, Doğanlar O. The Role of Melatonin in Oxidative Stress, DNA Damage, Apoptosis and Angiogenesis in Fetal Eye under Preeclampsia and Melatonin Deficiency Stress. Curr Eye Res 2019; 44:1157-1169. [PMID: 31090463 DOI: 10.1080/02713683.2019.1619778] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Aim: The aim of this study was to investigate the possible mechanisms of ocular damage induced by pinealectomy (PNX) and preeclampsia (PE), and to determine the cellular and molecular effects of melatonin treatment on oxidative stress, DNA damage, molecular chaperone responses, induction of apoptosis and angiogenesis in the fetal eye of both PNX and PNX+PE animals. Material and Methods: We analysed therapeutic potential of melatonin on fetal eye damage in PNX and PNX+PE animals using Malondialdehyde (MDA), Random Amplified Polymorphic DNA (RAPD), qRT-PCR and Western blot assays. Results: Our study presents three preliminary findings: (a) in fetal eye tissues, PNX and PNX+PE significantly induce oxidative damage to both DNA and protein contents, leading to a dramatic increase in caspase-dependent apoptotic signalling in both mitochondrial and death receptor pathways; (b) the same conditions trigger hypoxia biomarkers in addition to significant overexpression of HIF1-α, HIF1-β, MMP9 and VEGF genes in the fetal eye; (c) finally, melatonin regulates not only the expression of genes encoding antioxidant enzymes and increase in DNA damage as well as lipid peroxidation but also limits programmed cell death processes in the fetal eye of PNX and PNX+PE animals . Furthermore, melatonin can relatively modulate genes in the HIF1 family, TNF-α and VEGF, thus acting as a direct anti-angiogenic molecule. In conclusion, both PNX and PNX+PE induce ocular damage at both cellular and molecular levels in fetal eye tissue of rats. Conclusion: Our results clearly indicate the potential of melatonin as a preventative therapeutic intervention for fetal ocular damage triggered by both PNX and PNX+PE.
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Affiliation(s)
- Zeynep Banu Doğanlar
- Department of Medical Biology, Faculty of Medicine, Trakya University , Edirne , Turkey
| | - Hande Güçlü
- Department of Ophthalmology, Faculty of Medicine, Trakya University , Edirne , Turkey
| | - Özlem Öztopuz
- Department of Biophysics, Faculty of Medicine, Çanakkale Onsekiz Mart University , Çanakkale , Turkey
| | - Hakan Türkön
- Department of Biochemistry, Faculty of Medicine, Çanakkale Onsekiz Mart University , Çanakkale , Turkey
| | - Ayten Dogan
- Department of Medical Biology, Faculty of Medicine, Trakya University , Edirne , Turkey
| | - Metehan Uzun
- Department of Physiology, Faculty of Medicine, Çanakkale Onsekiz Mart University , Çanakkale , Turkey
| | - Oguzhan Doğanlar
- Department of Medical Biology, Faculty of Medicine, Trakya University , Edirne , Turkey
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18
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Nabavi SM, Nabavi SF, Sureda A, Xiao J, Dehpour AR, Shirooie S, Silva AS, Baldi A, Khan H, Daglia M. Anti-inflammatory effects of Melatonin: A mechanistic review. Crit Rev Food Sci Nutr 2019; 59:S4-S16. [DOI: 10.1080/10408398.2018.1487927] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Seyed Fazel Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Antoni Sureda
- Grup de Nutrici_o Comunit_aria i Estr_es Oxidatiu and CIBEROBN (Physiopathology of Obesity and Nutrition), Universitat de les Illes Balears, Palma de E-07122 Mallorca, Spain
| | - Janbo Xiao
- Institute of Chinese Medical Sciences, State Key Laboratory of Quality Control in Chinese Medicine, University of Macau, Macau SAR, China
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Samira Shirooie
- School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ana Sanches Silva
- National Institute for Agricultural and Veterinary Research (INIAV), I.P., Vairão, Vila do Conde, Portugal; Center for Study in Animal Science (CECA), ICETA, University of Oporto, Oporto, Portugal
| | - Alessandra Baldi
- Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section, University of Pavia, Pavia, Italy
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, Pakistan
| | - Maria Daglia
- Department of Drug Sciences, Medicinal Chemistry and Pharmaceutical Technology Section, University of Pavia, Pavia, Italy
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19
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Xu Z, Chu Z, Li W, Sun T, Sun X. Grape seed extracts attenuate retinal Müller cell gliosis in streptozotocin-diabetic rats. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.09.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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20
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Dehdashtian E, Mehrzadi S, Yousefi B, Hosseinzadeh A, Reiter RJ, Safa M, Ghaznavi H, Naseripour M. Diabetic retinopathy pathogenesis and the ameliorating effects of melatonin; involvement of autophagy, inflammation and oxidative stress. Life Sci 2018; 193:20-33. [DOI: 10.1016/j.lfs.2017.12.001] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 11/19/2017] [Accepted: 12/01/2017] [Indexed: 12/12/2022]
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21
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KLF9 and JNK3 Interact to Suppress Axon Regeneration in the Adult CNS. J Neurosci 2017; 37:9632-9644. [PMID: 28871032 DOI: 10.1523/jneurosci.0643-16.2017] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/22/2017] [Accepted: 08/23/2017] [Indexed: 01/22/2023] Open
Abstract
Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9's axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor sites, Ser106 and Ser110, effectively abolished KLF9's neurite growth suppression in vitro and promoted axon regeneration in vivo These findings demonstrate a novel, physiologic role for the interaction of KLF9 and JNK3 in regenerative failure in the optic nerve and suggest new therapeutic strategies to promote axon regeneration in the adult CNS.SIGNIFICANCE STATEMENT Injured CNS nerves fail to regenerate spontaneously. Promoting intrinsic axon growth capacity has been a major challenge in the field. Here, we demonstrate that knocking down Krüppel-like transcription factor 9 (KLF9) via shRNA promotes long-distance axon regeneration after optic nerve injury and uncover a novel and important KLF9-JNK3 interaction that contributes to axon growth suppression in vitro and regenerative failure in vivo These studies suggest potential therapeutic approaches to promote axon regeneration in injury and other degenerative diseases in the adult CNS.
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22
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Crooke A, Huete-Toral F, Colligris B, Pintor J. The role and therapeutic potential of melatonin in age-related ocular diseases. J Pineal Res 2017; 63. [PMID: 28658514 DOI: 10.1111/jpi.12430] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 12/20/2022]
Abstract
The eye is continuously exposed to solar UV radiation and pollutants, making it prone to oxidative attacks. In fact, oxidative damage is a major cause of age-related ocular diseases including cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy. As the nature of lens cells, trabecular meshwork cells, retinal ganglion cells, retinal pigment epithelial cells, and photoreceptors is postmitotic, autophagy plays a critical role in their cellular homeostasis. In age-related ocular diseases, this process is impaired, and thus, oxidative damage becomes irreversible. Other conditions such as low-grade chronic inflammation and angiogenesis also contribute to the development of retinal diseases (glaucoma, age-related macular degeneration and diabetic retinopathy). As melatonin is known to have remarkable qualities such as antioxidant/antinitridergic, mitochondrial protector, autophagy modulator, anti-inflammatory, and anti-angiogenic, it can represent a powerful tool to counteract all these diseases. The present review analyzes the role and therapeutic potential of melatonin in age-related ocular diseases, focusing on nitro-oxidative stress, autophagy, inflammation, and angiogenesis mechanisms.
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Affiliation(s)
- Almudena Crooke
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Fernando Huete-Toral
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Basilio Colligris
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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23
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Zhao Z, Yang M, Azar SR, Soong L, Weaver SC, Sun J, Chen Y, Rossi SL, Cai J. Viral Retinopathy in Experimental Models of Zika Infection. Invest Ophthalmol Vis Sci 2017; 58:4355–4365. [PMID: 28810265 PMCID: PMC5558627 DOI: 10.1167/iovs.17-22016] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Purpose Emerging evidence has shown that both congenital and adult Zika virus (ZIKV) infection can cause eye diseases. The goals of the current study were to explore mechanisms and pathophysiology of ZIKV-induced eye defects. Methods Wild-type or A129 interferon type I receptor–deficient mice were infected by either FSS13025 or Mex1-7 strain of ZIKV. Retinal histopathology was measured at different time points after infection. The presence of viral RNA and protein in the retina was determined by in situ hybridization and immunofluorescence staining, respectively. Growth curves of ZIKV in permissive retinal cells were assessed in cultured retinal pigment epithelial (RPE) and Müller glial cells. Results ZIKV-infected mice developed a spectrum of ocular pathologies that affected multiple layers of the retina. A primary target of ZIKV in the eye was Müller glial cells, which displayed decreased neurotrophic function and increased expression of proinflammatory cytokines after infection. ZIKV also infected RPE; and both the RPE and Müller cells expressed viral entry receptors TYRO3 and AXL. Retinitis, focal retinal degeneration, and ganglion cell loss were observed after the clearance of viral particles. Conclusions Our data suggest that ZIKV can infect infant eyes with immature blood–retinal barrier and cause structural damages to the retina. The ocular findings in microcephalic infants may not be solely caused by ZIKV-induced impairment of neurodevelopment.
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Affiliation(s)
- Zhenyang Zhao
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Matthew Yang
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Sasha R Azar
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Lynn Soong
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Scott C Weaver
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiaren Sun
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Yan Chen
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Shannan L Rossi
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiyang Cai
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
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Melatonin Decreases Glucose Metabolism in Prostate Cancer Cells: A 13C Stable Isotope-Resolved Metabolomic Study. Int J Mol Sci 2017; 18:ijms18081620. [PMID: 28933733 PMCID: PMC5578012 DOI: 10.3390/ijms18081620] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 07/18/2017] [Accepted: 07/20/2017] [Indexed: 12/18/2022] Open
Abstract
The pineal neuroindole melatonin exerts an exceptional variety of systemic functions. Some of them are exerted through its specific membrane receptors type 1 and type 2 (MT1 and MT2) while others are mediated by receptor-independent mechanisms. A potential transport of melatonin through facilitative glucose transporters (GLUT/SLC2A) was proposed in prostate cancer cells. The prostate cells have a particular metabolism that changes during tumor progression. During the first steps of carcinogenesis, oxidative phosphorylation is reactivated while the switch to the “Warburg effect” only occurs in advanced tumors and in the metastatic stage. Here, we investigated whether melatonin might change prostate cancer cell metabolism. To do so, 13C stable isotope-resolved metabolomics in androgen sensitive LNCaP and insensitive PC-3 prostate cancer cells were employed. In addition to metabolite 13C-labeling, ATP/AMP levels, and lactate dehydrogenase or pentose phosphate pathway activity were measured. Melatonin reduces lactate labeling in androgen-sensitive cells and it also lowers 13C-labeling of tricarboxylic acid cycle metabolites and ATP production. In addition, melatonin reduces lactate 13C-labeling in androgen insensitive prostate cancer cells. Results demonstrated that melatonin limits glycolysis as well as the tricarboxylic acid cycle and pentose phosphate pathway in prostate cancer cells, suggesting that the reduction of glucose uptake is a major target of the indole in this tumor type.
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Inhibition of Reactive Gliosis in the Retina of Rats with Streptozotocin-Induced Diabetes under the Action of Hydrated C60 Fullerene. NEUROPHYSIOLOGY+ 2016. [DOI: 10.1007/s11062-016-9579-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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LeBlanc ME, Wang W, Chen X, Ji Y, Shakya A, Shen C, Zhang C, Gonzalez V, Brewer M, Ma JX, Wen R, Zhang F, Li W. The regulatory role of hepatoma-derived growth factor as an angiogenic factor in the eye. Mol Vis 2016; 22:374-86. [PMID: 27122967 PMCID: PMC4842004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 04/21/2016] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Hepatoma-derived growth factor (HDGF) is a mitogen that promotes endothelial proliferation and neuronal survival. Using a unique technology of ligandomics, we recently identified HDGF as a retinal endothelial binding protein. The purpose of this study is to examine the role of HDGF in regulating ocular vasculature and the expression of HDGF in the retina. METHODS HDGF expression in the retinal was analyzed with western blot and immunohistochemistry. Angiogenic activity was investigated in human retinal microvascular endothelial cells (HRMVECs) with in vitro endothelial proliferation, migration, and permeability assays. In vivo angiogenic activity was quantified with a corneal pocket assay. The Evans blue assay and western blot using anti-mouse albumin were performed to detect the capacity of HDGF to induce retinal vascular leakage. RESULTS Immunohistochemistry revealed that HDGF is expressed in the retina with a distinct pattern. HDGF was detected in retinal ganglion cells and the inner nuclear layer but not in the inner plexiform layer, suggesting that HDGF is expressed in the nucleus, but not in the cytoplasm, of retinal neurons. In contrast to family member HDGF-related protein 3 (HRP-3) that has no expression in photoreceptors, HDGF is also present in the outer nuclear layer and the inner and outer segments of photoreceptors. This suggests that HDGF is expressed in the nucleus as well as the cytoplasm of photoreceptors. In vitro functional assays showed that HDGF induced the proliferation, migration, and permeability of HRMVECs. Corneal pocket assay indicated that HDGF directly stimulated angiogenesis in vivo. Intravitreal injection of HDGF significantly induced retinal vascular leakage. CONCLUSIONS These results suggest that HDGF is an angiogenic factor that regulates retinal vasculature in physiologic and pathological conditions. Identification of HDGF by ligandomics and its independent characterization in this study also support the validity of this new technology for systematic identification of cellular ligands, including angiogenic factors.
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Affiliation(s)
- Michelle E. LeBlanc
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Weiwen Wang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Xiuping Chen
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL,Department of Ophthalmology, Zhongshan Hospital of Fudan University, Shanghai, China
| | - Yanli Ji
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL,Department of Ophthalmology, 2nd People’s Hospital of Zhengzhou, Zhengzhou, Henan, China
| | - Akhalesh Shakya
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Chen Shen
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Chenming Zhang
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL,Department of Ophthalmology, Jinan 2nd People’s Hospital, Jinan, China
| | - Vivianne Gonzalez
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Megan Brewer
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Jian-xing Ma
- Department of Physiology, the University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Rong Wen
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL
| | - Fangliang Zhang
- Department of Molecular and Cellular Pharmacology, Sylvester Comprehensive Cancer Center, University of Miami, School of Medicine
| | - Wei Li
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL,Vascular Biology Institute, University of Miami School of Medicine, Miami, FL
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27
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Protective Effects of Melatonin on Retinal Inflammation and Oxidative Stress in Experimental Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3528274. [PMID: 27143993 PMCID: PMC4837288 DOI: 10.1155/2016/3528274] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 12/11/2022]
Abstract
Oxidative stress and inflammation are important pathogenic factors contributing to the etiology of diabetic retinopathy (DR). Melatonin is an endogenous hormone that exhibits a variety of biological effects including antioxidant and anti-inflammatory functions. The goals of this study were to determine whether melatonin could ameliorate retinal injury and to explore the potential mechanisms. Diabetes was induced by a single intraperitoneal (i.p.) injection of STZ (60 mg/kg) in Sprague-Dawley rats. Melatonin (10 mg kg(-1) daily, i.p.) was administered from the induction of diabetes and continued for up to 12 weeks, after which the animals were sacrificed and retinal samples were collected. The retina of diabetic rats showed depletion of glutathione and downregulation of glutamate cysteine ligase (GCL). Melatonin significantly upregulated GCL by retaining Nrf2 in the nucleus and stimulating Akt phosphorylation. The production of proinflammatory cytokines and proteins, including interleukin 1β, TNF-α, and inducible nitric oxide synthase (iNOS), was inhibited by melatonin through the NF-κB pathway. At 12 weeks, melatonin prevented the significant decrease in the ERG a- and b-wave amplitudes under the diabetic condition. Our results suggest potent protective functions of melatonin in diabetic retinopathy. In addition to being a direct antioxidant, melatonin can exert receptor-mediated signaling effects to attenuate inflammation and oxidative stress of the retina.
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28
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Xue Y, Shen SQ, Corbo JC, Kefalov VJ. Circadian and light-driven regulation of rod dark adaptation. Sci Rep 2015; 5:17616. [PMID: 26626567 PMCID: PMC4667277 DOI: 10.1038/srep17616] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/02/2015] [Indexed: 01/10/2023] Open
Abstract
Continuous visual perception and the dark adaptation of vertebrate photoreceptors after bright light exposure require recycling of their visual chromophore through a series of reactions in the retinal pigmented epithelium (RPE visual cycle). Light-driven chromophore consumption by photoreceptors is greater in daytime vs. nighttime, suggesting that correspondingly higher activity of the visual cycle may be required. However, as rod photoreceptors are saturated in bright light, the continuous turnover of their chromophore by the visual cycle throughout the day would not contribute to vision. Whether the recycling of chromophore that drives rod dark adaptation is regulated by the circadian clock and light exposure is unknown. Here, we demonstrate that mouse rod dark adaptation is slower during the day or after light pre-exposure. This surprising daytime suppression of the RPE visual cycle was accompanied by light-driven reduction in expression of Rpe65, a key enzyme of the RPE visual cycle. Notably, only rods in melatonin-proficient mice were affected by this daily visual cycle modulation. Our results demonstrate that the circadian clock and light exposure regulate the recycling of chromophore in the RPE visual cycle. This daily melatonin-driven modulation of rod dark adaptation could potentially protect the retina from light-induced damage during the day.
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Affiliation(s)
- Yunlu Xue
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Ophthalmology &Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Graduate Program in Division of Biological &Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Susan Q Shen
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Pathology &Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Graduate Program in Division of Biological &Biomedical Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Joseph C Corbo
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Pathology &Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Vladimir J Kefalov
- Washington University School of Medicine, St. Louis, Missouri 63110, USA.,Department of Ophthalmology &Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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29
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Liu S, Guo Y, Yuan Q, Pan Y, Wang L, Liu Q, Wang F, Wang J, Hao A. Melatonin prevents neural tube defects in the offspring of diabetic pregnancy. J Pineal Res 2015; 59:508-17. [PMID: 26475080 DOI: 10.1111/jpi.12282] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/02/2015] [Indexed: 01/11/2023]
Abstract
Melatonin, an endogenous neurohormone secreted by the pineal gland, has a variety of physiological functions and neuroprotective effects. However, its protective role on the neural tube defects (NTDs) was not very clear. The aim of this study was to investigate the effects of melatonin on the incidence of NTDs (including anencephaly, encephalocele, and spina bifida) of offspring from diabetic pregnant mice as well as its underlying mechanisms. Pregnant mice were given 10 mg/kg melatonin by daily i.p. injection from embryonic day (E) 0.5 until being killed on E11.5. Here, we showed that melatonin decreased the NTDs (especially exencephaly) rate of embryos exposed to maternal diabetes. Melatonin stimulated proliferation of neural stem cells (NSCs) under hyperglycemic condition through the extracellular regulated protein kinases (ERK) pathway. Furthermore, as a direct free radical scavenger, melatonin decreased apoptosis of NSCs exposed to hyperglycemia. In the light of these findings, it suggests that melatonin supplementation may play an important role in the prevention of neural malformations in diabetic pregnancy.
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Affiliation(s)
- Shangming Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Yuji Guo
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Qiuhuan Yuan
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Yan Pan
- Institute of Biomedical Engineering, Shandong University School of Medicine, Jinan, Shandong, China
| | - Liyan Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Qian Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Fuwu Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jingjing Wang
- Institute of Pathology and Pathophysiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, Jinan, Shandong, China
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30
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Wang Y, Cameron EG, Li J, Stiles TL, Kritzer MD, Lodhavia R, Hertz J, Nguyen T, Kapiloff MS, Goldberg JL. Muscle A-Kinase Anchoring Protein-α is an Injury-Specific Signaling Scaffold Required for Neurotrophic- and Cyclic Adenosine Monophosphate-Mediated Survival. EBioMedicine 2015; 2:1880-7. [PMID: 26844267 PMCID: PMC4703706 DOI: 10.1016/j.ebiom.2015.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 10/17/2015] [Accepted: 10/22/2015] [Indexed: 12/11/2022] Open
Abstract
Neurotrophic factor and cAMP-dependent signaling promote the survival and neurite outgrowth of retinal ganglion cells (RGCs) after injury. However, the mechanisms conferring neuroprotection and neuroregeneration downstream to these signals are unclear. We now reveal that the scaffold protein muscle A-kinase anchoring protein-α (mAKAPα) is required for the survival and axon growth of cultured primary RGCs. Although genetic deletion of mAKAPα early in prenatal RGC development did not affect RGC survival into adulthood, nor promoted the death of RGCs in the uninjured adult retina, loss of mAKAPα in the adult increased RGC death after optic nerve crush. Importantly, mAKAPα was required for the neuroprotective effects of brain-derived neurotrophic factor and cyclic adenosine-monophosphate (cAMP) after injury. These results identify mAKAPα as a scaffold for signaling in the stressed neuron that is required for RGC neuroprotection after optic nerve injury. mAKAPα is a stress-specific mediator of RGC survival. mAKAP deletion does not affect RGC survival in development or in the uninjured adult retina. mAKAP is downregulated after optic nerve injury, and its further deletion exacerbates RGC death. mAKAP deletion suppresses the neuroprotective effects of cAMP and BDNF after injury.
After injury or in degenerative diseases, neurons of the central nervous system (CNS) fail to regenerate and often die partly due to a lack of pro-survival, trophic signaling. Better understanding of such signaling is important for the development of therapies that enhance survival and regeneration of neurons after injury. Here we identify a critical regulator of such signaling, mAKAPα, a scaffold protein that coordinates pro-survival signaling to enhance survival and regeneration in CNS neurons after injury. The neuroprotective role of mAKAPα will likely lead to further future insights into the detailed nature of survival signaling in adult neurons.
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Affiliation(s)
- Yan Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States; Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Evan G Cameron
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States; Byers Eye Institute, Stanford University, Palo Alto, CA 94303, United States
| | - Jinliang Li
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Travis L Stiles
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Michael D Kritzer
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Rahul Lodhavia
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Jonathan Hertz
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States
| | - Tu Nguyen
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Michael S Kapiloff
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Jeffrey L Goldberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States; Department of Ophthalmology, University of California, San Diego, CA 92093, United States; Byers Eye Institute, Stanford University, Palo Alto, CA 94303, United States
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31
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Ranieri D, Avitabile D, Shiota M, Yokomizo A, Naito S, Bizzarri M, Torrisi MR. Nuclear redox imbalance affects circadian oscillation in HaCaT keratinocytes. Int J Biochem Cell Biol 2015; 65:113-24. [PMID: 26028291 DOI: 10.1016/j.biocel.2015.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/30/2015] [Accepted: 05/15/2015] [Indexed: 12/29/2022]
Abstract
Circadian clock is regulated by a transcriptional/translational feedback loop (TTFL) lasting ∼24 h. Circadian oscillation of peroxiredoxins (PRDX1-6) redox status has been shown in mature erythrocytes. We have recently reported that nuclear levels of PRDX2 are circadian regulated in the HaCaT keratinocytes. In this study, we addressed whether PRDX2 translocation could influence the TTFL. A reporter HaCaT cell line stably expressing the luciferase gene under control of Bmal1 promoter was lentivirally transduced either with an empty vector (EV), a vector carrying a myc-tagged wild type PRDX2 (PRDX2-Myc) or the same gene with a nuclear localization sequence (PRDX2-MycNuc). PRDX2 overexpressing cells were protected from H2O2-induced oxidative stress. The amplitude of the Bmal1 promoter activity was significantly dampened in PRDX2-MycNuc versus EV cells when synchronized either by dexamethasone treatment or temperature cycles. Clock synchronization was not affected in PRDX2 silenced cells. N-acetyl cysteine or melatonin treatments, significantly dampened the Bmal1 promoter activity suggesting that sustained scavenging of ROS impairs clock synchronization. Noteworthy, H2O2 treatment rescued proper oscillation of the clock in synchronized PRDX2-MycNuc HaCaT cells. Since the histone deacetylase Sirtuin 1 (Sirt1) modulates clock gene expression amplitude, the effect of Sirt1 activator resveratrol or Sirt1 inhibitor nicotinamide were also investigated. Interestingly, NAM enhanced the molecular clock synchronization in PRDX2-MycNuc cells. Our findings demonstrate that PRDX2 regulates the TTFL oscillation by finely tuning the cellular redox status of the nucleus likely influencing the deacetilase activity of SIRT1 enzyme.
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Affiliation(s)
- Danilo Ranieri
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Medicina Clinica e Molecolare, Sapienza Università di Roma, Rome, Italy
| | - Daniele Avitabile
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Medicina Clinica e Molecolare, Sapienza Università di Roma, Rome, Italy; Laboratorio di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino IRCCS, Milan, Italy.
| | - Masaki Shiota
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Akira Yokomizo
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Seiji Naito
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Mariano Bizzarri
- Dipartimento di Medicina Sperimentale, Sapienza Università di Roma, Italy
| | - Maria Rosaria Torrisi
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Medicina Clinica e Molecolare, Sapienza Università di Roma, Rome, Italy; Azienda Ospedaliera S. Andrea, Rome, Italy
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32
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Molecular aspects of melatonin (MLT)-mediated therapeutic effects. Life Sci 2015; 135:147-57. [DOI: 10.1016/j.lfs.2015.06.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 06/15/2015] [Accepted: 06/23/2015] [Indexed: 01/08/2023]
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Hevia D, González-Menéndez P, Quiros-González I, Miar A, Rodríguez-García A, Tan DX, Reiter RJ, Mayo JC, Sainz RM. Melatonin uptake through glucose transporters: a new target for melatonin inhibition of cancer. J Pineal Res 2015; 58:234-50. [PMID: 25612238 DOI: 10.1111/jpi.12210] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/15/2015] [Indexed: 12/17/2022]
Abstract
Melatonin is present in a multitude of taxa and it has a broad range of biological functions, from synchronizing circadian rhythms to detoxifying free radicals. Some functions of melatonin are mediated by its membrane receptors but others are receptor-independent. For the latter, melatonin must enter into the cell. Melatonin is a derivative of the amino acid tryptophan and reportedly easily crosses biological membranes due to its amphipathic nature. However, the mechanism by which melatonin enters into cells remains unknown. Changes in redox state, endocytosis pathways, multidrug resistance, glycoproteins or a variety of strategies have no effect on melatonin uptake. Herein, it is demonstrated that members of the SLC2/GLUT family glucose transporters have a central role in melatonin uptake. When studied by docking simulation, it is found that melatonin interacts at the same location in GLUT1 where glucose does. Furthermore, glucose concentration and the presence of competitive ligands of GLUT1 affect the concentration of melatonin into cells. As a regulatory mechanism, melatonin reduces the uptake of glucose and modifies the expression of GLUT1 transporter in prostate cancer cells. More importantly, glucose supplementation promotes prostate cancer progression in TRAMP mice, while melatonin attenuated glucose-induced tumor progression and prolonged the lifespan of tumor-bearing mice. This is the first time that a facilitated transport of melatonin is suggested. In fact, the important role of glucose transporters and glucose metabolism in cell fate might explain some of the diverse functions described for melatonin.
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Affiliation(s)
- David Hevia
- Departamento de Morfología y Biología Celular, Instituto Universitario Oncológico del Principado de Asturias (IUOPA), Universidad de Oviedo, Oviedo, Spain
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Primary retinal cultures as a tool for modeling diabetic retinopathy: an overview. BIOMED RESEARCH INTERNATIONAL 2015; 2015:364924. [PMID: 25688355 PMCID: PMC4320900 DOI: 10.1155/2015/364924] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/04/2014] [Accepted: 12/23/2014] [Indexed: 12/21/2022]
Abstract
Experimental models of diabetic retinopathy (DR) have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight.
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36
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Donovan K, Alekseev O, Qi X, Cho W, Azizkhan-Clifford J. O-GlcNAc modification of transcription factor Sp1 mediates hyperglycemia-induced VEGF-A upregulation in retinal cells. Invest Ophthalmol Vis Sci 2014; 55:7862-73. [PMID: 25352121 DOI: 10.1167/iovs.14-14048] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
PURPOSE Proangiogenic protein VEGF-A contributes significantly to retinal lesions and neovascularization in diabetic retinopathy (DR). In preclinical DR, hyperglycemia can upregulate VEGF-A in retinal cells. The VEGF-A promoter is responsive to the transcription factor specificity protein 1 (Sp1). The O-GlcNAc modification is driven by glucose concentration and has a profound effect on Sp1 activity. This study investigated the effects of hyperglycemia on Sp1-mediated expression of VEGF-A in the retinal endothelium and pigment epithelium. METHODS Hyperglycemia-exposed ARPE-19 (human retinal pigment epithelial cells) and TR-iBRB (rat retinal microendothelial cells) were assayed for levels of VEGF-A by qRT-PCR, Western blot, and ELISA. Small molecule inhibitors of O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) were used to manipulate O-GlcNAc levels. Vascular endothelial growth factor-A protein and transcript were measured in cells depleted of OGT or Sp1 by shRNA. The proximal VEGF-A promoter was analyzed for glucose sensitivity by luciferase assay. Chromatin immunoprecipitation (ChIP) was used to assess Sp1 occupancy on the VEGF-A promoter. RESULTS Hyperglycemia increased VEGF-A promoter activity and upregulated VEGF-A transcript and protein. Elevation of O-GlcNAc by OGA inhibitors was sufficient to increase VEGF-A. O-GlcNAc transferase inhibition abrogated glucose-driven VEGF-A. Cellular depletion of OGT or Sp1 by shRNA significantly abrogated glucose-induced changes in VEGF-A. ChIP analysis showed that hyperglycemia significantly increased binding of Sp1 to the VEGF-A promoter. CONCLUSIONS Hyperglycemia-driven VEGF-A production is mediated by elevated O-GlcNAc modification of the Sp1 transcription factor. This mechanism may be significant in the pathogenesis of preclinical DR through VEGF-A upregulation.
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Affiliation(s)
- Kelly Donovan
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
| | - Oleg Alekseev
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
| | - Xin Qi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - William Cho
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
| | - Jane Azizkhan-Clifford
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
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37
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The beneficial effect of melatonin in brain endothelial cells against oxygen-glucose deprivation followed by reperfusion-induced injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:639531. [PMID: 25126203 PMCID: PMC4122057 DOI: 10.1155/2014/639531] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 06/07/2014] [Accepted: 06/20/2014] [Indexed: 12/31/2022]
Abstract
Melatonin has a cellular protective effect in cerebrovascular and neurodegenerative diseases. Protection of brain endothelial cells against hypoxia and oxidative stress is important for treatment of central nervous system (CNS) diseases, since brain endothelial cells constitute the blood brain barrier (BBB). In the present study, we investigated the protective effect of melatonin against oxygen-glucose deprivation, followed by reperfusion- (OGD/R-) induced injury, in bEnd.3 cells. The effect of melatonin was examined by western blot analysis, cell viability assays, measurement of intracellular reactive oxygen species (ROS), and immunocytochemistry (ICC). Our results showed that treatment with melatonin prevents cell death and degradation of tight junction protein in the setting of OGD/R-induced injury. In response to OGD/R injury of bEnd.3 cells, melatonin activates Akt, which promotes cell survival, and attenuates phosphorylation of JNK, which triggers apoptosis. Thus, melatonin protects bEnd.3 cells against OGD/R-induced injury.
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38
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Xie M, Hu A, Luo Y, Sun W, Hu X, Tang S. Interleukin-4 and melatonin ameliorate high glucose and interleukin-1β stimulated inflammatory reaction in human retinal endothelial cells and retinal pigment epithelial cells. Mol Vis 2014; 20:921-8. [PMID: 24991184 PMCID: PMC4077596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 07/26/2014] [Indexed: 11/05/2022] Open
Abstract
PURPOSE We aimed to evaluate the effects of two immune regulatory factors, interleukin-4 (IL-4) and melatonin, on several inflammatory mediators that are involved in inflammation and angiogenesis in diabetic retinopathy (DR), in high glucose or interleukin-1β (IL-1β) induced primary human retinal endothelial cells (RECs) and human retinal pigment epithelial (RPE) cells. METHODS Human RECs and RPE cells were cultured in 30 mM D-glucose or 10 ng/ml IL-1β, with or without the presence of 40 ng/ml IL-4 or 100 μM melatonin. The mRNA and protein levels of vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), matrix metalloproteinases 2 (MMP2), and matrix metalloproteinases 9 (MMP9) were measured using real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS High glucose and IL-1β induced the expression of VEGF, ICAM-1, MMP2, and MMP9 in human RECs and RPE cells. IL-4 and melatonin downregulated the expression of VEGF, ICAM-1, MMP2, and MMP9 induced by high glucose and IL-1β. CONCLUSIONS Our results demonstrated that IL-4 and melatonin inhibited inflammation and angiogenesis triggered by high glucose and IL-1β, which suggests that these immune regulatory factors may be of potential therapeutic value in DR.
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Affiliation(s)
- Manyun Xie
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Andina Hu
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yan Luo
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Wei Sun
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xinqian Hu
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha, China,Aier Eye Hospital Group, Changsha, China,Aier Research Institute of Ophthalmology, Changsha, China
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39
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Ozdemir G, Ergün Y, Bakariş S, Kılınç M, Durdu H, Ganiyusufoğlu E. Melatonin prevents retinal oxidative stress and vascular changes in diabetic rats. Eye (Lond) 2014; 28:1020-7. [PMID: 24924441 DOI: 10.1038/eye.2014.127] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 04/24/2014] [Indexed: 02/06/2023] Open
Abstract
PURPOSE To evaluate the role of melatonin, an antioxidant agent, in diabetic oxidative stress and vascular damage. METHODS Diabetes was induced in 21 male Wistar rats by intraperitoneal (IP) administration of streptozotocin and then the rats were equally and randomly allocated to diabetic, melatonin, and vehicle groups. Seven healthy normal rats with similar features comprised the control group as the fourth group. All animals were followed for 12 weeks. The melatonin group received IP melatonin daily and the vehicle group received 2.5% ethanol IP at the last month. At the end of 12 weeks, the rats were killed and retinas were harvested. The retinas were investigated for the existence of hypoxia-inducible factor 1-α (HIF-1α), vascular endothelial growth factor A (VEGF-A), and pigment epithelium-derived factor (PEDF) by ELISA. Retinal oxidative stress is quantitated by measuring nitrotyrosine and malondialdehyde levels. Retinal immunohistochemistry with antibody against CD31 antigen was carried out on retinal cross-sections. For statistics, ANOVA test was used for multiple comparisons. RESULTS Hyperglycemia increased retinal oxidation as measured through levels of nitrotyrosine and malondialdehyde. Diabetic retinas are also associated with abnormal vascular changes such as dilatation and deformation. HIF-1α, VEGF-A, and PEDF were all increased because of diabetic injury. Melatonin showed a potential beneficial effect on retinopathy in diabetic rats. It decreased retinal nitrotyrosine and malondialdehyde levels, showing an antioxidative support. The vasculomodulator cytokines are decreased accordingly by melatonin therapy. Melatonin normalized retinal vascular changes as well. CONCLUSION Melatonin may show some advantage on diabetic vascular changes through decreasing oxidative stress and vessel-related cytokines.
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Affiliation(s)
- G Ozdemir
- Department of Ophthalmology, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
| | - Y Ergün
- Department of Pharmacology, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
| | - S Bakariş
- Department of Pathology, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
| | - M Kılınç
- Department of Biochemistry, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
| | - H Durdu
- Department of Pathology, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
| | - E Ganiyusufoğlu
- Department of Biochemistry, Faculty of Medicine, Kahramanmaraş Sütçüimam University, Kahramanmaraş, Turkey
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40
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Park JH, Shim HM, Na AY, Bae KC, Bae JH, Im SS, Cho HC, Song DK. Melatonin prevents pancreatic β-cell loss due to glucotoxicity: the relationship between oxidative stress and endoplasmic reticulum stress. J Pineal Res 2014; 56:143-53. [PMID: 24168371 DOI: 10.1111/jpi.12106] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/25/2013] [Indexed: 12/31/2022]
Abstract
Prolonged hyperglycemia results in pancreatic β-cell dysfunction and apoptosis, referred to as glucotoxicity. Although both oxidative and endoplasmic reticulum (ER) stresses have been implicated as major causative mechanisms of β-cell glucotoxicity, the reciprocal importance between the two remains to be elucidated. The aim of this study was to evaluate the differential effect of oxidative stress and ER stress on β-cell glucotoxicity, by employing melatonin which has free radical-scavenging and antioxidant properties. As expected, in β-cells exposed to prolonged high glucose levels, cell viability and glucose-stimulated insulin secretion (GSIS) were significantly impaired. Melatonin treatment markedly attenuated cellular apoptosis by scavenging reactive oxygen species via its plasmalemmal receptor-independent increase in antioxidant enzyme activity. However, treatments with antioxidants alone were insufficient to recover the impaired GSIS. Interestingly, 4-phenylbutyric acid (4-PBA), a chemical chaperone that attenuate ER stress by stabilizing protein structure, alleviated the impaired GSIS, but not apoptosis, suggesting that glucotoxicity induces oxidative and ER stress independently. We found that cotreatment of glucotoxic β-cells with melatonin and 4-PBA dramatically improved both their survival and insulin secretion. Taken together, these results suggest that ER stress may be the more critical mechanism for prolonged high-glucose-induced GSIS impairment, whereas oxidative stress appears to be more critical for the impaired β-cell viability. Therefore, combinatorial therapy of melatonin with an ER stress modifier may help recover pancreatic β-cells under glucotoxic conditions in type 2 diabetes.
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Affiliation(s)
- Jae-Hyung Park
- Department of Physiology, Keimyung University School of Medicine, Daegu, Korea
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Hardeland R. Melatonin and the theories of aging: a critical appraisal of melatonin's role in antiaging mechanisms. J Pineal Res 2013; 55:325-56. [PMID: 24112071 DOI: 10.1111/jpi.12090] [Citation(s) in RCA: 192] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 02/06/2023]
Abstract
The classic theories of aging such as the free radical theory, including its mitochondria-related versions, have largely focused on a few specific processes of senescence. Meanwhile, numerous interconnections have become apparent between age-dependent changes previously thought to proceed more or less independently. Increased damage by free radicals is not only linked to impairments of mitochondrial function, but also to inflammaging as it occurs during immune remodeling and by release of proinflammatory cytokines from mitotically arrested, DNA-damaged cells that exhibit the senescence-associated secretory phenotype (SASP). Among other effects, SASP can cause mutations in stem cells that reduce the capacity for tissue regeneration or, in worst case, lead to cancer stem cells. Oxidative stress has also been shown to promote telomere attrition. Moreover, damage by free radicals is connected to impaired circadian rhythmicity. Another nexus exists between cellular oscillators and metabolic sensing, in particular to the aging-suppressor SIRT1, which acts as an accessory clock protein. Melatonin, being a highly pleiotropic regulator molecule, interacts directly or indirectly with all the processes mentioned. These influences are critically reviewed, with emphasis on data from aged organisms and senescence-accelerated animals. The sometimes-controversial findings obtained either in a nongerontological context or in comparisons of tumor with nontumor cells are discussed in light of evidence obtained in senescent organisms. Although, in mammals, lifetime extension by melatonin has been rarely documented in a fully conclusive way, a support of healthy aging has been observed in rodents and is highly likely in humans.
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Affiliation(s)
- Rüdiger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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Bai J, Dong L, Song Z, Ge H, Cai X, Wang G, Liu P. The role of melatonin as an antioxidant in human lens epithelial cells. Free Radic Res 2013; 47:635-42. [DOI: 10.3109/10715762.2013.808743] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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