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Callan A, Jha S, Valdez L, Tsin A. Cellular and Molecular Mechanisms of Neuronal Degeneration in Early-Stage Diabetic Retinopathy. Curr Vasc Pharmacol 2024; 22:301-315. [PMID: 38693745 DOI: 10.2174/0115701611272737240426050930] [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: 07/18/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 05/03/2024]
Abstract
BACKGROUND Studies on the early retinal changes in Diabetic Retinopathy (DR) have demonstrated that neurodegeneration precedes vascular abnormalities like microaneurysms or intraretinal hemorrhages. Therefore, there is a growing field of study to analyze the cellular and molecular pathways involved to allow for the development of novel therapeutics to prevent the onset or delay the progression of DR. Molecular Mechanisms: Oxidative stress and mitochondrial dysfunction contribute to neurodegeneration through pathways involving polyol, hexosamine, advanced glycation end products, and protein kinase C. Potential interventions targeting these pathways include aldose reductase inhibitors and protein kinase C inhibitors. Neurotrophic factor imbalances, notably brain-derived neurotrophic factor and nerve growth factor, also play a role in early neurodegeneration, and supplementation of these neurotrophic factors show promise in mitigating neurodegeneration. Cellular Mechanisms: Major cellular mechanisms of neurodegeneration include caspase-mediated apoptosis, glial cell reactivity, and glutamate excitotoxicity. Therefore, inhibitors of these pathways are potential therapeutic avenues. Vascular Component: The nitric oxide pathway, critical for neurovascular coupling, is disrupted in DR due to increased reactive oxygen species. Vascular Endothelial Growth Factor (VEGF), a long-known angiogenic factor, has demonstrated both damaging and neuroprotective effects, prompting a careful consideration of long-term anti-VEGF therapy. CONCLUSION Current DR treatments primarily address vascular symptoms but fall short of preventing or halting the disease. Insights into the mechanisms of retinal neurodegeneration in the setting of diabetes mellitus not only enhance our understanding of DR but also pave the way for future therapeutic interventions aimed at preventing disease progression and preserving vision.
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Affiliation(s)
- Andrew Callan
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, USA
| | - Sonal Jha
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, USA
| | - Laura Valdez
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, USA
| | - Andrew Tsin
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, USA
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2
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Mirzahosseini G, Adam JM, Nasoohi S, El-Remessy AB, Ishrat T. Lost in Translation: Neurotrophins Biology and Function in the Neurovascular Unit. Neuroscientist 2023; 29:694-714. [PMID: 35769016 DOI: 10.1177/10738584221104982] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The neurovascular unit (NVU) refers to the functional building unit of the brain and the retina, where neurons, glia, and microvasculature orchestrate to meet the demand of the retina's and brain's function. Neurotrophins (NTs) are structural families of secreted proteins and are known for exerting neurotrophic effects on neuronal differentiation, survival, neurite outgrowth, synaptic formation, and plasticity. NTs include several molecules, such as nerve growth factor, brain-derived neurotrophic factor, NT-3, NT-4, and their precursors. Furthermore, NTs are involved in signaling pathways such as inflammation, apoptosis, and angiogenesis in a nonneuronal cell type. Interestingly, NTs and the precursors can bind and activate the p75 neurotrophin receptor (p75NTR) at low and high affinity. Mature NTs bind their cognate tropomyosin/tyrosine-regulated kinase receptors, crucial for maintenance and neuronal development in the brain and retina axis. Activation of p75NTR results in neuronal apoptosis and cell death, while tropomysin receptor kinase upregulation contributes to differentiation and cell growth. Recent findings indicate that modulation of NTs and their receptors contribute to neurovascular dysfunction in the NVU. Several chronic metabolic and acute ischemic diseases affect the NVU, including diabetic and ischemic retinopathy for the retina, as well as stroke, acute encephalitis, and traumatic brain injury for the brain. This work aims to review the current evidence through published literature studying the impact of NTs and their receptors, including the p75NTR receptor, on the injured and healthy brain-retina axis.
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Affiliation(s)
- Golnoush Mirzahosseini
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Justin Mark Adam
- Department of Medicine, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Sanaz Nasoohi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Tauheed Ishrat
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
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3
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Liu Y, Xu Z, Zheng H, Yang J, Wu M, Yang Q, Wang Y, Zong T, Yang X, Xie T, Cai J, Yao Y, Wang X. MiR-423-5p promotes Müller cell activation via targeting NGF signaling in diabetic retinopathy. Life Sci 2023; 334:122217. [PMID: 37925140 DOI: 10.1016/j.lfs.2023.122217] [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: 08/09/2022] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/06/2023]
Abstract
AIMS Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus and one of the major causes of visual impairment and blindness in industrialized countries. The early neuro-glial perturbations, especially retinal Müller cells (rMC) activation, intimately associated with the vascular alterations. MicroRNAs (miRNAs) have been reported to play critical roles in the progression of DR. Here, we aimed to further explore the role and underlying mechanism of miR-423-5p in Müller cell activation in streptozotocin (STZ)-induced diabetic mice and oxygen-induced retinopathy (OIR) model. MATERIALS AND METHODS Retinal histology, optical coherence tomography (OCT) and biochemical markers were assessed. KEY FINDINGS Our data revealed that the expression of miR-423-5p was significantly increased under high-glucose environment. We also demonstrated that miR-423-5p overexpression markedly accelerated retinal vascular leakage, leukocytosis, and rMC activation. This response was ameliorated in animals pre-treated with the inhibition of miR-423-5p. Specifically, miR-423-5p bound to the nerve growth factor (NGF) 3' UTR region to induce its silencing. NGF inhibition significantly promoted retinal microvascular dysfunction. SIGNIFICANCE These findings demonstrate that miR-423-5p is a critical miRNA that promotes microvascular dysfunction in DR.
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Affiliation(s)
- Yanqiu Liu
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Zifan Xu
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Haohan Zheng
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Jiahui Yang
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Meili Wu
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Qian Yang
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China; Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Yan Wang
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Tianyi Zong
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Xusheng Yang
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Tianhua Xie
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Jiping Cai
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China
| | - Yong Yao
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China.
| | - Xiaolu Wang
- Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China; Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, 299 Qingyang Road, Wuxi, Jiangsu 214023, People's Republic of China.
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Lacalle-Aurioles M, Iturria-Medina Y. Fornix degeneration in risk factors of Alzheimer's disease, possible trigger of cognitive decline. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2023; 4:100158. [PMID: 36703699 PMCID: PMC9871745 DOI: 10.1016/j.cccb.2023.100158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
Risk factors of late-onset Alzheimer's disease (AD) such as aging, type 2 diabetes, obesity, heart failure, and traumatic brain injury can facilitate the appearance of cognitive decline and dementia by triggering cerebrovascular pathology and neuroinflammation. White matter (WM) microstructure and function are especially vulnerable to these conditions. Microstructural WM changes, assessed with diffusion weighted magnetic resonance imaging, can already be detected at preclinical stages of AD, and in the presence of the aforementioned risk factors. Particularly, the limbic system and cortico-cortical association WM tracts, which myelinate late during brain development, degenerate at the earliest stages. The fornix, a C-shaped WM tract that originates from the hippocampus, is one of the limbic tracts that shows early microstructural changes. Fornix integrity is necessary for ensuring an intact executive function and memory performance. Thus, a better understanding of the mechanisms that cause fornix degeneration is critical in the development of therapeutic strategies aiming to prevent cognitive decline in populations at risk. In this literature review, i) we deepen the idea that partial loss of forniceal integrity is an early event in AD, ii) we describe the role that common risk factors of AD can play in the degeneration of the fornix, and iii) we discuss some potential cellular and physiological mechanisms of WM degeneration in the scenario of cerebrovascular disease and inflammation.
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Affiliation(s)
- María Lacalle-Aurioles
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montréal, QC H3A 2B4, Canada,Corresponding author at: Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada.
| | - Yasser Iturria-Medina
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montréal, QC H3A 2B4, Canada,Ludmer Centre for Neuroinformatics and Mental Health, McGill University, Montreal, Canada,McConnell Brain Imaging Centre, McGill University, Montreal, Canada
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5
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Li B, Ning B, Yang F, Guo C. Nerve Growth Factor Promotes Retinal Neurovascular Unit Repair: A Review. Curr Eye Res 2022; 47:1095-1105. [PMID: 35499266 DOI: 10.1080/02713683.2022.2055084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Purpose: The purpose of this paper is to investigate how the imbalance of neurogenic factor (NGF) and its precursor (pro-NGF) mediates structural and functional impairment of retinal neurovascular unit (RNVU) that plays a role in retinal degenerative diseases.Methods: A literature search of electronic databases was performed.Results: The pro-apoptotic effect of pro-NGF and the pro-growth effect of NGF are essential for the pathological and physiological activities of RNVU. Studies show that NGF-based treatment of retinal degenerative diseases, including glaucoma, age-related macular degeneration, retinitis pigmentosa, and diabetic retinopathy, has achieved remarkable efficacy.Conclusions: RNVU plays a complex and multifaceted role in retinal degenerative diseases. The exploration of the differential signaling expression of proNGF-NGF homeostasis under physiological and pathological conditions, and the corresponding pathological processes induced by its regulation, has prompted us to focus on earlier retinal neuroprotective therapeutic strategies to prevent retinal degenerative diseases.
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Affiliation(s)
- Baohua Li
- The First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, PR China
| | - Bobiao Ning
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, PR China
| | - Fan Yang
- The First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, PR China
| | - Chengwei Guo
- The First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, PR China
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6
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Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
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Barraza DE, Sari LM, Apichela SA, Ratto MH, Argañaraz ME. New Insights Into the Role of β-NGF/TrKA System in the Endometrium of Alpacas During Early Pregnancy. Front Vet Sci 2021; 7:583369. [PMID: 33553274 PMCID: PMC7862743 DOI: 10.3389/fvets.2020.583369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/07/2020] [Indexed: 11/18/2022] Open
Abstract
One striking reproductive feature in South American camelids is that more than 90% of gestations are established in the left uterine horn (LUH). This phenomenon could be related to a differential vascular irrigation of the LUH. An increase of vascularization in llama endometrium was observed after systemic administration of Beta Nerve Growth Factor (β-NGF), a neurotrophin present in the uterus and placenta of various mammals that is involved in pregnancy development. We hypothesized that the β-NGF signaling pathway is related to embryo implantation in the LUH in camelids. The aim of this study was to characterize the spatial expression of β-NGF and its high-affinity receptor, TrKA, between LUH and right uterine horn (RUH) of non-pregnant (NP) and early pregnant alpacas (15 and 30 days of gestation, 15 and 30P, respectively). In addition, β-NGF, TrKA, and Vascular Endothelium Growth Factor A (VEGFA) temporal gene expression patterns and counting of blood vessels were evaluated among groups. The β-NGF and TrKA were localized in the luminal, glandular, and vascular epithelium of the alpaca uterus and in the embryonic membranes of the 30-days-old conceptus. β-NGF and TrKA immunosignal were stronger in 15P females than that of NP and 30P. In addition, TrKA signal was higher in the LUH luminal epithelium of NP and 15P alpacas than that of NP-RUH and 15P-RUH. β-NGF mRNA relative abundance was higher in the 30P-RUH than that of NP-RUH; whereas TrKA mRNA abundance only differed between 15P-RUH and NP-LUH. VEGFA mRNA relative abundance was higher in NP females compared to the LUH of 15P and 30P alpacas, and lower to their right counterparts. The number of vessels per field was higher in 15P than that of 30P. A positive correlation was observed between the number of vessels per field and β-NGF immunosignal in 15P-LUH. In contrast, the area occupied by vessels was higher in 30P alpacas than of NP and 15P females. The changes of β-NGF/TrKA expression pattern in the peri-implantation endometria between LUH and RUH and their localization in the extraembryonic membranes support the implication of the neurotrophin during implantation and pregnancy development in South American Camelids.
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Affiliation(s)
- Daniela E Barraza
- Instituto Superior de Investigaciones Biológicas (INSIBIO), Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Tucumán (CONICET-UNT), and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina
| | - Luciana M Sari
- Instituto Superior de Investigaciones Biológicas (INSIBIO), Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Tucumán (CONICET-UNT), and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina
| | - Silvana A Apichela
- Instituto Superior de Investigaciones Biológicas (INSIBIO), Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Tucumán (CONICET-UNT), and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina.,Cátedra de Zootecnia General I, Facultad de Agronomía y Zootecnia, UNT, San Miguel de Tucumán, Argentina
| | - Marcelo H Ratto
- Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Martin E Argañaraz
- Instituto Superior de Investigaciones Biológicas (INSIBIO), Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Tucumán (CONICET-UNT), and Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina.,Cátedra de Biología Celular y Molecular, Facultad de Bioquímica, Química y Farmacia, UNT, San Miguel de Tucumán, Argentina
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Esposito G, Balzamino BO, Bruno L, Cacciamani A, Micera A. NGF in Inflammatory and Neurodegenerative Diseases of the Eye: New Findings Supporting Neuroprotection and Proper Tissue Remodeling in Vitreoretinal Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1331:265-273. [PMID: 34453305 DOI: 10.1007/978-3-030-74046-7_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nerve growth factor (NGF) plays a crucial role in retinal disorders, as suggested by in vitro/in vivo models. The major effect embraces the neuroprotective activity on retinal ganglion cells (RGCs) undergoing degeneration, as observed in experimental diabetic retinopathy, age-related and diabetic macular degeneration, and some vitreoretinal diseases. Focused experiments suggested that locally applied NGF (intravitreal delivery) not only allowed the counteraction of RGC degeneration but also provided data for a whole retina restoration. The currently available retinal microsurgery allows the collection of human aqueous and more interesting vitreous (vitreal reflux) humors. The recent biomolecular analysis highlights the possibility to identify disease-associated biomarkers and allow the monitoring of retinal impairments with sustain to the retinal imaging. Coupled to other soluble mediators, NGF has been quantified in aqueous (slightly expressed) from diabetic retinopathy-suffering patients (cataract surgery) and vitreal reflux (significantly impaired) of diabetic macular degeneration-suffering patients (intravitreal surgery). Although the reasons of these NGF impairments are not fully comprehended, some retinal cells (glial cells, bipolar neurons, and RGCs) have been recognized partially responsible for these local changes.Taken together, the recent progress in the ocular microsurgeries might be associated with sampling of small amount of ocular humors, allowing the collection of biochemical information about diseased retina and the monitoring of treatment. The chance to detect NGF and likewise other neuroprotective or pro-/anti-inflammatory factors in these fluids would open to the possibility to identify biomarkers of early diagnosis or monitoring of retinal disease evolution/therapy (precision medicine).
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Affiliation(s)
- Graziana Esposito
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences IRCCS - Fondazione Bietti, Rome, Italy
| | - Bijorn Omar Balzamino
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences IRCCS - Fondazione Bietti, Rome, Italy
| | - Luca Bruno
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences IRCCS - Fondazione Bietti, Rome, Italy
| | - Andrea Cacciamani
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences IRCCS - Fondazione Bietti, Rome, Italy
| | - Alessandra Micera
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences IRCCS - Fondazione Bietti, Rome, Italy. .,Head of Research Laboratories in Ophthalmology, IRCCS - Fondazione Bietti, Rome, Italy.
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9
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Rashid RR, Fazal A, Khan QU, Ul Qamar M, Ahmed F, Laique T. Comparison of Serum Brain-Derived Neurotrophic Factor Levels in Diabetic Patients With and Without Retinopathy. Cureus 2020; 12:e12028. [PMID: 33457130 PMCID: PMC7797422 DOI: 10.7759/cureus.12028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Introduction Diabetes mellitus (DM) is a disease of carbohydrate, protein, and fats metabolism that results in hyperglycemia. It may also result from defects in the secretion of insulin from beta cells or in its action on target cells or both. Objective To determine the levels of brain-derived neurotrophic factor (BDNF) and glycated hemoglobulin (HbA1c) with the progression of retinopathy. Methodology The study was done on 80 patients who were divided into four groups (A, B, C, D), with 20 individuals each, on the basis of their diabetic status and fundoscopic findings. Serum BDNF levels were measured by using an enzyme-linked immunosorbent assay kit (Glory Science Co., Taichung City, Taiwan). Results On analysis, a significant decline was seen in serum BDNF levels in diabetics as compared with non-diabetics (p < 0.001), but a significant reduction in levels with the progression of retinopathy was observed (p < 0.001). Statistical analysis All the data were processed using the Statistical Package for the Social Sciences (SPSS) v20.0 (IBM Corp., Armonk, NY). Conclusion There is a significant decline in serum BDNF levels in type 2 diabetics with retinopathy in comparison with the healthy control group.
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Affiliation(s)
- Romana R Rashid
- Physiology, Akhtar Saeed Medical and Dental College, Lahore, PAK
| | - Ayesha Fazal
- Physiology, Akhtar Saeed Medical and Dental College, Lahore, PAK
| | - Qudsia U Khan
- Physiology, Combined Military Hospital (CMH) Lahore Medical and Dental College, Lahore, PAK
| | - Misbah Ul Qamar
- Physiology, Akhtar Saeed Medical and Dental College, Lahore, PAK
| | | | - Talha Laique
- Pharmacology, Lahore Medical and Dental College, Lahore, PAK
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10
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Mossa AH, Galan A, Cammisotto PG, Velasquez Flores M, Shamout S, Barcelona P, Saragovi HU, Campeau L. Antagonism of proNGF or its receptor p75 NTR reverses remodelling and improves bladder function in a mouse model of diabetic voiding dysfunction. Diabetologia 2020; 63:1932-1946. [PMID: 32699962 DOI: 10.1007/s00125-020-05222-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/18/2020] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Although 80% of diabetic patients will suffer from voiding difficulties and urinary symptoms, defined as diabetic voiding dysfunction (DVD), therapeutic targets and treatment options are limited. We hypothesise that the blockade of the pro-nerve growth factor (NGF)/p75 neurotrophin receptor (p75NTR) axis by an anti-proNGF monoclonal antibody or by a small molecule p75NTR antagonist (THX-B) can restore bladder remodelling (represented by bladder weight) in an animal model of DVD. Secondary outcomes of the study include improvements in bladder compliance, contractility and morphology, as well as in voiding behaviour, proNGF/NGF balance and TNF-α expression. METHODS In a streptozotocin-induced mouse model of diabetes, diabetic mice received either a blocking anti-proNGF monoclonal antibody or a p75NTR antagonist small molecule as weekly systemic injections for 4 weeks. Animals were tested at baseline (at 2 weeks of diabetes induction), and after 2 and 4 weeks of treatment. Outcomes measured were voiding function with voiding spot assays and cystometry. Bladders were assessed by histological, contractility and protein expression assays. RESULTS Diabetic mice showed features of DVD as early as 2 weeks after diabetes diagnosis (baseline) presented by hypertrophy, reduced contractility and abnormal cystometric parameters. Following treatment initiation, a twofold increase (p < 0.05) in untreated diabetic mouse bladder weight and thickness compared with non-diabetic controls was observed, and this change was reversed by p75NTR antagonism (37% reduction in bladder weight compared with untreated diabetic mice [95% CI 14%, 60%]) after 4 weeks of treatment. However, blocking proNGF did not help to reverse bladder hypertrophy. While diabetic mice had significantly worse cystometric parameters and contractile responses than non-diabetic controls, proNGF antagonism normalised bladder compliance (0.007 [Q1-Q3; 0.006-0.009] vs 0.015 [Q1-Q3; 0.014-0.029] ml/cmH2O in untreated diabetic mice, representing 62% reduction [95% CI 8%, 110%], p < 0.05) and contractility to KCl, carbachol and electrical field stimulation (p < 0.05 compared with the diabetic group) after 2 weeks of treatment. These effects were not observed after 4 weeks of treatment with proNGF antagonist. p75NTR antagonism did not show important improvements in cystometric parameters after 2 weeks of treatment. Slightly improved bladder compliance (0.01 [Q1-Q3; 0.009-0.012] vs 0.013 [Q1-Q3; 0.011-0.016] ml/cmH2O for untreated diabetic mice) was seen in the p75NTR antagonist-treated group after 4 weeks of treatment with significantly stabilised contractile responses to KCl, carbachol and electric field stimulation (p < 0.05 for each) compared with diabetic mice. Bladder dysfunction observed in diabetic mice was associated with a significant increase in bladder proNGF/NGF ratio (3.1 [±1.2] vs 0.26 [±0.04] ng/pg in control group, p < 0.05 at week 2 of treatment) and TNF-α (p < 0.05). The proNGF/NGF ratio was partially reduced (about 60% reduction) with both treatments (1.03 [±0.6] ng/pg for proNGF antibody-treated group and 1.4 [±0.76] ng/pg for p75NTR blocker-treated group after 2 weeks of treatment), concomitant with a significant decrease in the bladder levels of TNF-α (p < 0.05), despite persistent hyperglycaemia. CONCLUSIONS/INTERPRETATION Our findings indicate that blockade of proNGF and the p75NTR receptor in diabetes can impede the development and progression of DVD. The reported improvements in morphological and functional features in our DVD model validates the proNGF/p75NTR axis as a potential therapeutic target in this pathology. Graphical abstract.
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Affiliation(s)
- Abubakr H Mossa
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - Alba Galan
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - Philippe G Cammisotto
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - Monica Velasquez Flores
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - Samer Shamout
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
- Division of Urology, Department, of Surgery, McGill University, Montreal, QC, Canada
| | - Pablo Barcelona
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
| | - H Uri Saragovi
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
- Center for Experimental Therapeutics, Jewish General Hospital, Montreal, QC, Canada
- Department of Ophthalmology and Vision Sciences, McGill University, Montreal, QC, Canada
| | - Lysanne Campeau
- Lady Davis Research Institute, McGill University, 3755 Chemin de la Cote-Ste-Catherine, Montreal, QC, H3T 1E2, Canada.
- Division of Urology, Department, of Surgery, McGill University, Montreal, QC, Canada.
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11
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Narayanan SP, Shosha E, D Palani C. Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy. Pharmacol Res 2019; 147:104299. [PMID: 31207342 PMCID: PMC7011157 DOI: 10.1016/j.phrs.2019.104299] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/23/2019] [Accepted: 06/05/2019] [Indexed: 12/20/2022]
Abstract
Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.
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Affiliation(s)
- S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; VA Medical Center, Augusta, GA, United States.
| | - Esraa Shosha
- Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; Clinical Pharmacy Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Chithra D Palani
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States
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12
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Bahr HI, Abdelghany AA, Galhom RA, Barakat BM, Arafa ESA, Fawzy MS. Duloxetine protects against experimental diabetic retinopathy in mice through retinal GFAP downregulation and modulation of neurotrophic factors. Exp Eye Res 2019; 186:107742. [PMID: 31344388 DOI: 10.1016/j.exer.2019.107742] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 12/23/2022]
Abstract
Diabetic retinopathy (DR) is recognized as one of the leading causes of blindness worldwide. Searching and validation for a novel therapeutic strategy to prevent its progress are promising. This work aimed to assess the retinal protective effects of duloxetine (DLX) in Alloxan-induced diabetic mice model. Animals were equally and randomly divided to four groups (eight mice per group); group 1: is the control group, 2: diabetic group, 3&4: diabetic and after 9 weeks received DLX for 4 weeks (15 mg/kg and 30 mg/kg), respectively. Quantitative real-time PCR (qPCR) analysis revealed nerve growth factor (NGF), inducible nitric oxide synthase (iNOS) and transforming growth factor beta (TGF-β) genes upregulation in the diabetic group compared to controls. Also, increased retinal malondialdehyde (MDA) and the decline of reduced glutathione (GSH) levels were observed. The morphometric analysis of diabetic retina revealed a significant reduction in total retinal thickness compared to control. Diabetic retinal immunostaining and Western blot analyses displayed glial fibrillary acidic protein (GFAP) and vascular endothelial cell growth factor (VEGF) proteins expression upregulation as well as glucose transporter-1 (GLUT-1) downregulation comparing to controls. However, DLX-treated groups showed downregulated NGF, iNOS, and TGF-β that was more obviously seen in the DLX-30 mg/kg group than DLX-15 mg/kg group. Furthermore, these groups showed amelioration of the oxidative markers; MDA and GSH, retaining the total retinal thickness nearly to control, GFAP and VEGF downregulation, and GLUT-1 upregulation compared to diabetic group. Taken together, it could be summarized that duloxetine can attenuate DR via the anti-inflammatory and the anti-oxidative properties as well as modulating the angiogenic and the neurotrophic factors expressions. This could hopefully pave the road to be included in the novel list of the therapeutic regimen for DR after validation in the clinic.
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Affiliation(s)
- Hoda I Bahr
- Department of Biochemistry, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Ahmed A Abdelghany
- Department of Ophthalmology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Rania A Galhom
- Department of Human Anatomy and Embryology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Bassant M Barakat
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt; Department of Clinical Pharmacy, College of Clinical Pharmacy, Al-Baha University, Al-Baha, Saudi Arabia.
| | - El-Shaimaa A Arafa
- Department of Clinical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman, 346, United Arab Emirates; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, 62514, Egypt.
| | - Manal S Fawzy
- Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia; Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
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13
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Rossino MG, Casini G. Nutraceuticals for the Treatment of Diabetic Retinopathy. Nutrients 2019; 11:nu11040771. [PMID: 30987058 PMCID: PMC6520779 DOI: 10.3390/nu11040771] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/19/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus and is characterized by degeneration of retinal neurons and neoangiogenesis, causing a severe threat to vision. Nowadays, the principal treatment options for DR are laser photocoagulation, vitreoretinal surgery, or intravitreal injection of drugs targeting vascular endothelial growth factor. However, these treatments only act at advanced stages of DR, have short term efficacy, and cause side effects. Treatment with nutraceuticals (foods providing medical or health benefits) at early stages of DR may represent a reasonable alternative to act upstream of the disease, preventing its progression. In particular, in vitro and in vivo studies have revealed that a variety of nutraceuticals have significant antioxidant and anti-inflammatory properties that may inhibit the early diabetes-driven molecular mechanisms that induce DR, reducing both the neural and vascular damage typical of DR. Although most studies are limited to animal models and there is the problem of low bioavailability for many nutraceuticals, the use of these compounds may represent a natural alternative method to standard DR treatments.
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Affiliation(s)
| | - Giovanni Casini
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, 56124 Pisa, Italy.
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14
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Subirada PV, Paz MC, Ridano ME, Lorenc VE, Vaglienti MV, Barcelona PF, Luna JD, Sánchez MC. A journey into the retina: Müller glia commanding survival and death. Eur J Neurosci 2018; 47:1429-1443. [PMID: 29790615 DOI: 10.1111/ejn.13965] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/19/2018] [Accepted: 05/03/2018] [Indexed: 12/12/2022]
Abstract
Müller glial cells (MGCs) are known to participate actively in retinal development and to contribute to homoeostasis through many intracellular mechanisms. As there are no homologous cells in other neuronal tissues, it is certain that retinal health depends on MGCs. These macroglial cells are located at the centre of the columnar subunit and have a great ability to interact with neurons, astrocytes, microglia and endothelial cells in order to modulate different events. Several investigations have focused their attention on the role of MGCs in diabetic retinopathy, a progressive pathology where several insults coexist. As expected, data suggest that MGCs display different responses according to the severity of the stimulus, and therefore trigger distinct events throughout the course of the disease. Here, we describe physiological functions of MGCs and their participation in inflammation, gliosis, synthesis and secretion of trophic and antioxidant factors in the diabetic retina. We invite the reader to consider the protective/deleterious role of MGCs in the early and late stages of the disease. In the light of the results, we open up the discussion around and ask the question: Is it possible that the modulation of a single cell type could improve or even re-establish retinal function after an injury?
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Affiliation(s)
- Paula V Subirada
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María C Paz
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Magali E Ridano
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Valeria E Lorenc
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Department of Ophthalmology, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - María V Vaglienti
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Pablo F Barcelona
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - José D Luna
- Centro Privado de Ojos Romagosa-Fundación VER, Córdoba, Argentina
| | - María C Sánchez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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15
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Drug Targets in Neurotrophin Signaling in the Central and Peripheral Nervous System. Mol Neurobiol 2018; 55:6939-6955. [PMID: 29372544 DOI: 10.1007/s12035-018-0885-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/08/2018] [Indexed: 12/12/2022]
Abstract
Neurotrophins are a family of proteins that play an important role in the regulation of the growth, survival, and differentiation of neurons in the central and peripheral nervous system. Neurotrophins were earlier characterized by their role in early development, growth, maintenance, and the plasticity of the nervous system during development, but recent findings also indicate their complex role during normal physiology in both neuronal and non-neuronal tissues. Therefore, it is important to recognize a deficiency in the expression of neurotrophins, a major factor driving the debilitating features of several neurologic and psychiatric diseases/disorders. On the other hand, overexpression of neurotrophins is well known to play a critical role in pathogenesis of chronic pain and afferent sensitization, underlying conditions such as lower urinary tract symptoms (LUTS)/disorders and osteoarthritis. The existence of a redundant receptor system of high-and low-affinity receptors accounts for the diverse, often antagonistic, effects of neurotrophins in neurons and non-neuronal tissues in a spatial and temporal manner. In addition, studies looking at bladder dysfunction because of conditions such as spinal cord injury and diabetes mellitus have found alterations in the levels of these neurotrophins in the bladder, as well as in sensory afferent neurons, which further opens a new avenue for therapeutic targets. In this review, we will discuss the characteristics and roles of key neurotrophins and their involvement in the central and periphery nervous system in both normal and diseased conditions.
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16
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Mohamed R, Shanab AY, El Remessy AB. Deletion of the Neurotrophin Receptor p75 NTR Prevents Diabetes-Induced Retinal Acellular Capillaries in Streptozotocin-Induced Mouse Diabetic Model. ACTA ACUST UNITED AC 2017; 4. [PMID: 29658956 DOI: 10.15406/jdmdc.2017.04.00129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Diabetic retinopathy is characterized by early stage of retinal neuro-inflammation that triggers development of acellular capillaries and a late stage of pathological neovascularization. Due to limited treatment options, there is a pressing need to develop new therapeutics. Our group discovered that diabetes-impaired processing of the nerve growth factor precursor (proNGF) resulting in its accumulation and its receptor p75NTR. Here, we examine the protective effects of modulating p75NTR in experimental model of diabetic retinopathy. Diabetes was induced using streptozotocin in both wild type (WT) and p75NTR knockout (p75KO) mice. Retinal inflammation and microvascular dysfunction were assessed. Western blot analysis was performed to assess expression of apoptotic and inflammatory markers and levels of the neurotrophin, p75NTR and ephrin-B2. Deletion of p75NTR did not alter body weight or diabetes status compared to WT mice. In WT-mice, diabetes triggered retinal inflammation, significant decrease in pericyte count and marked increase in development of occluded (acellular) capillary formation after 24-weeks. Deletion of p75NTR prevented acellular capillary, restored pericyte count, and inhibited the retinal Ephrin-B2, activation of the stress-kinase JNK and apoptotic marker cleaved caspase-3 in the diabetic retina. Deletion of p75NTR reduced retinal inflammation, and proNGF expression. These effects coincided with increased NGF level and TrkA activation in the diabetic retina. Targeting p75NTR using genetic approach protected the retina from the impact of long-term diabetes in mediating microvascular degeneration and maintains the balance of NGF/proNGF level. Together, these results provide rationale that targeting p75NTR may offer novel and effective therapeutic strategy to combat diabetic retinopathy.
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Affiliation(s)
- Riyaz Mohamed
- Charlie Norwood Veterans Affairs Medical Center, USA
| | | | - Azza B El Remessy
- Charlie Norwood Veterans Affairs Medical Center, USA.,Augusta Biomedical Research Foundation, USA
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17
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Inducible overexpression of endothelial proNGF as a mouse model to study microvascular dysfunction. Biochim Biophys Acta Mol Basis Dis 2017; 1864:746-757. [PMID: 29253516 DOI: 10.1016/j.bbadis.2017.12.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 12/07/2017] [Accepted: 12/13/2017] [Indexed: 12/14/2022]
Abstract
Impaired maturation of nerve growth factor precursor (proNGF) and its accumulation has been reported in several neurodegenerative diseases, myocardial infarction and diabetes. To elucidate the direct impact of proNGF accumulation identified the need to create a transgenic model that can express fully mutated cleavage-resistant proNGF. Using Cre-Lox technology, we developed an inducible endothelial-specific proNGF transgenic mouse (proNGFLoxp) that overexpresses GFP-conjugated cleavage-resistant proNGF123 when crossed with VE-cadherin-CreERT2 (Cre). Expression of proNGF, inflammatory mediators, NGF and VEGF was evaluated by PCR, Western blot and immunohistochemistry. EC-proNGF overexpression was confirmed using colocalization of anti-proNGF within retinal vasculature. EC-proNGF did not cause retinal neurotoxicity or marked glial activation at 4-weeks. Microvascular preparation from Cre-proNGF mice showed significant imbalance of proNGF/NGF ratio, enhanced expression of TNF-α and p75NTR, and tendency to impair TrkA phosphorylation compared to controls. EC-proNGF overexpression triggered mRNA expression of p75NTR and inflammatory mediators in both retina and renal cortex compared to controls. EC-proNGF expression induced vascular permeability including breakdown of BRB and albuminuria in the kidney without affecting VEGF level at 4-weeks. Histopathological changes were assessed after 8-weeks and the results showed that EC-proNGF triggered formation of occluded (acellular) capillaries, hall mark of retinal ischemia. EC-proNGF resulted in glomerular enlargement and kidney fibrosis, hall mark of renal dysfunction. We have successfully created an inducible mouse model that can dissect the contribution of autocrine direct action of cleavage-resistant proNGF on systemic microvascular abnormalities in both retina and kidney, major targets for microvascular complication.
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18
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Hu L, Qi S, Zhang K, Fu Q. Essential role of brain-derived neurotrophic factor (bdnf) in diabetic erectile dysfunction. Andrologia 2017; 50. [PMID: 29159909 DOI: 10.1111/and.12924] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2017] [Indexed: 01/09/2023] Open
Affiliation(s)
- L. Hu
- Department of Urology; Shandong Provincial Hospital Affiliated to Shandong University; Jinan China
- Department of Urology; Shandong Zaozhuang Municipal Hospital; Zaozhuang China
| | - S. Qi
- Department of Neurology; Shandong Zaozhuang Municipal Hospital; Zaozhuang China
| | - K. Zhang
- Department of Urology; Shandong Provincial Hospital Affiliated to Shandong University; Jinan China
| | - Q. Fu
- Department of Urology; Shandong Provincial Hospital Affiliated to Shandong University; Jinan China
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19
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Flavonoid Naringenin Attenuates Oxidative Stress, Apoptosis and Improves Neurotrophic Effects in the Diabetic Rat Retina. Nutrients 2017; 9:nu9101161. [PMID: 29064407 PMCID: PMC5691777 DOI: 10.3390/nu9101161] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the leading causes of decreased vision and blindness worldwide. Diabetes-induced oxidative stress is believed to be the key factor that initiates neuronal damage in the diabetic retina leading to DR. Experimental approaches to utilize dietary flavonoids, which possess both antidiabetic and antioxidant activities, might protect the retinal damage in diabetes. The aim of this study was to investigate the potential protective effects of naringenin in the retina of streptozotocin-induced diabetic rats. Diabetic rats were orally treated and untreated with naringenin (50 mg/kg/day) for five weeks and retinas were analyzed for markers of oxidative stress, apoptosis and neurotrophic factors. Systemic effects of naringenin treatments were also analyzed and compared with untreated groups. The results showed that elevated levels of thiobarbituric acid reactive substances (TBARs) and decreased level of glutathione (GSH) in diabetic rats were ameliorated with naringenin treatments. Moreover, decreased levels of neuroprotective factors (Brain derived neurotrophic factor (BDNF)), tropomyosin related kinase B (TrkB) and synaptophysin in diabetic retina were augmented with naringenin treatments. In addition, naringenin treatment ameliorated the levels of apoptosis regulatory proteins; B cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax) and caspase-3 in the diabetic retina. Thus, the study demonstrates the beneficial effects of naringenin that possesses anti-diabetic, antioxidant and antiapoptotic properties, which may limit neurodegeneration by providing neurotrophic support to prevent retinal damage in diabetic retinopathy.
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20
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Joseph M, Trinh HM, Cholkar K, Pal D, Mitra AK. Recent perspectives on the delivery of biologics to back of the eye. Expert Opin Drug Deliv 2017; 14:631-645. [PMID: 27573097 PMCID: PMC5570518 DOI: 10.1080/17425247.2016.1227783] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Biologics are generally macromolecules, large in size with poor stability in biological environments. Delivery of biologics to tissues at the back of the eye remains a challenge. To overcome these challenges and treat posterior ocular diseases, several novel approaches have been developed. Nanotechnology-based delivery systems, like drug encapsulation technology, macromolecule implants and gene delivery are under investigation. We provide an overview of emerging technologies for biologics delivery to back of the eye tissues. Moreover, new biologic drugs currently in clinical trials for ocular neovascular diseases have been discussed. Areas covered: Anatomy of the eye, posterior segment disease and diagnosis, barriers to biologic delivery, ocular pharmacokinetic, novel biologic delivery system Expert opinion: Anti-VEGF therapy represents a significant advance in developing biologics for the treatment of ocular neovascular diseases. Various strategies for biologic delivery to posterior ocular tissues are under development with some in early or late stages of clinical trials. Despite significant progress in the delivery of biologics, there is unmet need to develop sustained delivery of biologics with nearly zero-order release kinetics to the back of the eye tissues. In addition, elevated intraocular pressure associated with frequent intravitreal injections of macromolecules is another concern that needs to be addressed.
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Affiliation(s)
- Mary Joseph
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Hoang M. Trinh
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Kishore Cholkar
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
- RiconPharma LLC, 100 Ford Road, Suite 9, Denville, NJ, 07834 USA
| | - Dhananjay Pal
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Ashim K. Mitra
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
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21
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Elshaer SL, El-Remessy AB. Implication of the neurotrophin receptor p75 NTR in vascular diseases: beyond the eye. EXPERT REVIEW OF OPHTHALMOLOGY 2016; 12:149-158. [PMID: 28979360 DOI: 10.1080/17469899.2017.1269602] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION The p75 neurotrophin receptor (p75NTR) is a member of TNF-α receptor superfamily that bind all neurotrophins, mainly regulating their pro-apoptotic actions. Ischemia is a common pathology in different cardiovascular diseases affecting multiple organs, however the contribution of p75NTR remains not fully addressed. The aim of this work is to review the current evidence through published literature studying the impact of p75NTR receptor in ischemic vascular diseases. AREAS COVERED In the eye, several ischemic ocular diseases are associated with enhanced p75NTR expression. Ischemic retinopathy including diabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are characterized initially by ischemia followed by excessive neovascularization. Beyond the eye, cerebral ischemia, myocardial infarction and critical limb ischemia are ischemic cardiovascular diseases that are characterized by altered expression of neurotrophins and p75NTR expression. We surveyed both clinical and experimental studies that examined the impact of p75NTR receptor in ischemic diseases of eye, heart, brain and peripheral limbs. EXPERT COMMENTARY p75NTR receptor is a major player in multiple ischemic vascular diseases affecting the eye, brain, heart and peripheral limbs with significant increases in its expression accompanying neuro-vascular injury. This has been addressed in the current review along with the beneficial vascular outcomes of p75NTR inhibition.
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Affiliation(s)
- Sally L Elshaer
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA.,Research Service, Charlie Norwood VA Medical Center, Augusta, GA
| | - Azza B El-Remessy
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, USA.,Research Service, Charlie Norwood VA Medical Center, Augusta, GA.,Augusta Biomedical Research Corporation, Augusta, GA, USA
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22
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Yan PS, Tang S, Zhang HF, Guo YY, Zeng ZW, Wen Q. Nerve growth factor protects against palmitic acid-induced injury in retinal ganglion cells. Neural Regen Res 2016; 11:1851-1856. [PMID: 28123432 PMCID: PMC5204244 DOI: 10.4103/1673-5374.194758] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Accumulating evidence supports an important role for nerve growth factor (NGF) in diabetic retinopathy. We hypothesized that NGF has a protective effect on rat retinal ganglion RGC-5 cells injured by palmitic acid (PA), a metabolic factor implicated in the development of diabetes and its complications. Our results show that PA exposure caused apoptosis of RGC-5 cells, while NGF protected against PA insult in a concentration-dependent manner. Additionally, NGF significantly attenuated the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in RGC-5 cells. Pathway inhibitor tests showed that the protective effect of NGF was completely reversed by LY294002 (PI3K inhibitor), Akt VIII inhibitor, and PD98059 (ERK1/2 inhibitor). Western blot analysis revealed that NGF induced the phosphorylation of Akt/FoxO1 and ERK1/2 and reversed the PA-evoked reduction in the levels of these proteins. These results indicate that NGF protects RGC-5 cells against PA-induced injury through anti-oxidation and inhibition of apoptosis by modulation of the PI3K/Akt and ERK1/2 signaling pathways.
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Affiliation(s)
- Pan-Shi Yan
- Department of Ophthalmology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Shu Tang
- Department of Pharmacy, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Hai-Feng Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yuan-Yuan Guo
- Shenzhen Mental Health Center and Shenzhen Key Lab for Psychological Healthcare, Shenzhen, Guangdong Province, China
| | - Zhi-Wen Zeng
- Shenzhen Mental Health Center and Shenzhen Key Lab for Psychological Healthcare, Shenzhen, Guangdong Province, China
| | - Qiang Wen
- Department of Clinical Pharmacology, School of Basic Medicine, Zhengzhou University, Zhengzhou, Henan Province, China
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