1
|
Boff JM, Shrestha AP, Madireddy S, Viswaprakash N, Della Santina L, Vaithianathan T. The Interplay between Neurotransmitters and Calcium Dynamics in Retinal Synapses during Development, Health, and Disease. Int J Mol Sci 2024; 25:2226. [PMID: 38396913 PMCID: PMC10889697 DOI: 10.3390/ijms25042226] [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: 01/11/2024] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
The intricate functionality of the vertebrate retina relies on the interplay between neurotransmitter activity and calcium (Ca2+) dynamics, offering important insights into developmental processes, physiological functioning, and disease progression. Neurotransmitters orchestrate cellular processes to shape the behavior of the retina under diverse circumstances. Despite research to elucidate the roles of individual neurotransmitters in the visual system, there remains a gap in our understanding of the holistic integration of their interplay with Ca2+ dynamics in the broader context of neuronal development, health, and disease. To address this gap, the present review explores the mechanisms used by the neurotransmitters glutamate, gamma-aminobutyric acid (GABA), glycine, dopamine, and acetylcholine (ACh) and their interplay with Ca2+ dynamics. This conceptual outline is intended to inform and guide future research, underpinning novel therapeutic avenues for retinal-associated disorders.
Collapse
Affiliation(s)
- Johane M Boff
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Abhishek P Shrestha
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Saivikram Madireddy
- College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Nilmini Viswaprakash
- Department of Medical Education, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | | - Thirumalini Vaithianathan
- Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Aldosari DI, Malik A, Alhomida AS, Ola MS. Implications of Diabetes-Induced Altered Metabolites on Retinal Neurodegeneration. Front Neurosci 2022; 16:938029. [PMID: 35911994 PMCID: PMC9328693 DOI: 10.3389/fnins.2022.938029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the major complications of diabetic eye diseases, causing vision loss and blindness worldwide. The concept of diabetic retinopathy has evolved from microvascular disease into more complex neurovascular disorders. Early in the disease progression of diabetes, the neuronal and glial cells are compromised before any microvascular abnormalities clinically detected by the ophthalmoscopic examination. This implies understanding the pathophysiological mechanisms at the early stage of disease progression especially due to diabetes-induced metabolic alterations to damage the neural retina so that early intervention and treatments options can be identified to prevent and inhibit the progression of DR. Hyperglycemia has been widely considered the major contributor to the progression of the retinal damage, even though tight control of glucose does not seem to have a bigger effect on the incidence or progression of retinal damage that leads to DR. Emerging evidence suggests that besides diabetes-induced hyperglycemia, dyslipidemia and amino acid defects might be a major contributor to the progression of early neurovascular retinal damage. In this review, we have discussed recent advances in the alterations of key metabolites of carbohydrate, lipid, and amino acids and their implications for neurovascular damage in DR.
Collapse
|
4
|
Boccuni I, Fairless R. Retinal Glutamate Neurotransmission: From Physiology to Pathophysiological Mechanisms of Retinal Ganglion Cell Degeneration. Life (Basel) 2022; 12:638. [PMID: 35629305 PMCID: PMC9147752 DOI: 10.3390/life12050638] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate neurotransmission and metabolism are finely modulated by the retinal network, where the efficient processing of visual information is shaped by the differential distribution and composition of glutamate receptors and transporters. However, disturbances in glutamate homeostasis can result in glutamate excitotoxicity, a major initiating factor of common neurodegenerative diseases. Within the retina, glutamate excitotoxicity can impair visual transmission by initiating degeneration of neuronal populations, including retinal ganglion cells (RGCs). The vulnerability of RGCs is observed not just as a result of retinal diseases but has also been ascribed to other common neurodegenerative and peripheral diseases. In this review, we describe the vulnerability of RGCs to glutamate excitotoxicity and the contribution of different glutamate receptors and transporters to this. In particular, we focus on the N-methyl-d-aspartate (NMDA) receptor as the major effector of glutamate-induced mechanisms of neurodegeneration, including impairment of calcium homeostasis, changes in gene expression and signalling, and mitochondrial dysfunction, as well as the role of endoplasmic reticular stress. Due to recent developments in the search for modulators of NMDA receptor signalling, novel neuroprotective strategies may be on the horizon.
Collapse
Affiliation(s)
- Isabella Boccuni
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| |
Collapse
|
5
|
Rossino MG, Dal Monte M, Casini G. Relationships Between Neurodegeneration and Vascular Damage in Diabetic Retinopathy. Front Neurosci 2019; 13:1172. [PMID: 31787868 PMCID: PMC6856056 DOI: 10.3389/fnins.2019.01172] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes and constitutes a major cause of vision impairment and blindness in the world. DR has long been described exclusively as a microvascular disease of the eye. However, in recent years, a growing interest has been focused on the contribution of neuroretinal degeneration to the pathogenesis of the disease, and there are observations suggesting that neuronal death in the early phases of DR may favor the development of microvascular abnormalities, followed by the full manifestation of the disease. However, the mediators that are involved in the crosslink between neurodegeneration and vascular changes have not yet been identified. According to our hypothesis, vascular endothelial growth factor (VEGF) could probably be the most important connecting link between the death of retinal neurons and the occurrence of microvascular lesions. Indeed, VEGF is known to play important neuroprotective actions; therefore, in the early phases of DR, it may be released in response to neuronal suffering, and it would act as a double-edged weapon inducing both neuroprotective and vasoactive effects. If this hypothesis is correct, then any retinal stress causing neuronal damage should be accompanied by VEGF upregulation and by vascular changes. Similarly, any compound with neuroprotective properties should also induce VEGF downregulation and amelioration of the vascular lesions. In this review, we searched for a correlation between neurodegeneration and vasculopathy in animal models of retinal diseases, examining the effects of different neuroprotective substances, ranging from nutraceuticals to antioxidants to neuropeptides and others and showing that reducing neuronal suffering also prevents overexpression of VEGF and vascular complications. Taken together, the reviewed evidence highlights the crucial role played by mediators such as VEGF in the relationship between retinal neuronal damage and vascular alterations and suggests that the use of neuroprotective substances could be an efficient strategy to prevent the onset or to retard the development of DR.
Collapse
Affiliation(s)
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| |
Collapse
|
6
|
Shen J, Wang R, He Z, Huang H, He X, Zhou J, Yan Y, Shen S, Shao X, Shen X, Weng C, Lin W, Chen J. NMDA receptors participate in the progression of diabetic kidney disease by decreasing Cdc42-GTP activation in podocytes. J Pathol 2016; 240:149-60. [PMID: 27338016 DOI: 10.1002/path.4764] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 05/24/2016] [Accepted: 06/15/2016] [Indexed: 01/31/2023]
Abstract
Podocytes play important roles in the progression of diabetic kidney disease (DKD) and these roles are closely associated with cytoskeletal actin dynamics. N-Methyl-d-aspartate receptors (NMDARs), which consist of two functional NR1 subunits and two regulatory NR2 subunits, are widely expressed in the brain but are also found in podocytes. Here, we found increased NR1 expression in two diabetic mouse models and in podocytes incubated in high glucose (HG). In diabetic mice, knockdown of NR1 using lentivirus carrying NR1-shRNA ameliorated the pathological features associated with DKD, and reversed the decreased expression of synaptopodin and Wilms' tumour-1. In podocytes incubated with HG, NR1 was secreted from the endoplasmic reticulum and this was blocked by bisindolylmaleimide I. NR1 knockdown decreased the cell shape remodelling, cell collapse, bovine serum albumin permeability, and migration induced by HG. After HG incubation, levels of cell division control protein 42 (Cdc42) and its active form increased, and a significantly higher Cdc42-GTP level, increased Cdc42 translocation onto the leading edges, and lower migration ability were found in podocytes with NR1 knockdown. Increases in the number and length of filopodia were found in podocytes with NR1 knockdown but these were abolished by Cdc42-GTP blockade with ML141. In conclusion, the activation of NMDARs plays an important role in DKD by reducing Cdc42-GTP activation. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Jia Shen
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China. .,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China. .,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.
| | - Rending Wang
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Zhechi He
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Hongfeng Huang
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Xuelin He
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Jingyi Zhou
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Yinggang Yan
- Institute of Neuroscience, Zhejiang University School of Medicine, Hangzhou, China
| | - Shuijuan Shen
- Nephrology Department, Shaoxing People's Hospital of Zhejiang Province, Shaoxing, China
| | - Xue Shao
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Xiujin Shen
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Chunhua Weng
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China
| | - Weiqiang Lin
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China.,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianghua Chen
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China. .,Key Laboratory of Multiple Organ Transplantation, Ministry of Health, Hangzhou, China. .,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.
| |
Collapse
|
7
|
Hernández C, Dal Monte M, Simó R, Casini G. Neuroprotection as a Therapeutic Target for Diabetic Retinopathy. J Diabetes Res 2016; 2016:9508541. [PMID: 27123463 PMCID: PMC4830713 DOI: 10.1155/2016/9508541] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/29/2016] [Accepted: 03/16/2016] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy (DR) is a multifactorial progressive disease of the retina and a leading cause of vision loss. DR has long been regarded as a vascular disorder, although neuronal death and visual impairment appear before vascular lesions, suggesting an important role played by neurodegeneration in DR and the appropriateness of neuroprotective strategies. Upregulation of vascular endothelial growth factor (VEGF), the main target of current therapies, is likely to be one of the first responses to retinal hyperglycemic stress and VEGF may represent an important survival factor in early phases of DR. Of central importance for clinical trials is the detection of retinal neurodegeneration in the clinical setting, and spectral domain optical coherence tomography seems the most indicated technique. Many substances have been tested in animal studies for their neuroprotective properties and for possible use in humans. Perhaps, the most intriguing perspective is the use of endogenous neuroprotective substances or nutraceuticals. Together, the data point to the central role of neurodegeneration in the pathogenesis of DR and indicate neuroprotection as an effective strategy for treating this disease. However, clinical trials to determine not only the effectiveness and safety but also the compliance of a noninvasive route of drug administration are needed.
Collapse
Affiliation(s)
- Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
- *Cristina Hernández: and
| | - Massimo Dal Monte
- 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, Via del Borghetto 80, 56124 Pisa, Italy
| | - Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - 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, Via del Borghetto 80, 56124 Pisa, Italy
- *Giovanni Casini:
| |
Collapse
|
8
|
Fan N, Zhang M, Xu K, Ke X, Ding Y, Wang D, Liu Y, Ning Y, Deng X, He H. Serum level of vascular endothelial growth factor decreased in chronic ketamine abusers. Drug Alcohol Depend 2015; 152:57-61. [PMID: 26003336 PMCID: PMC4888963 DOI: 10.1016/j.drugalcdep.2015.04.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/17/2015] [Accepted: 04/22/2015] [Indexed: 12/27/2022]
Abstract
AIMS To evaluate the serum level of vascular endothelial growth factor (VEGF) in a group of chronic ketamine abusers in comparison to healthy controls. METHODS Eighty-one ketamine abusers who were hospitalized for the treatment of ketamine dependence and 39 healthy controls were recruited. Serum VEGF level was measured by enzyme linked immunosorbent assay (ELISA). Psychopathological symptoms were assessed using Positive and Negative Syndrome Scale (PANSS), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). RESULTS Serum level of VEGF was significantly lower in chronic ketamine abusers compared to healthy controls (64.6±42.1 vs. 92.4±59.4pg/ml, F=7.243, p=0.008). CONCLUSIONS Serum level of VEGF decreased in chronic ketamine abusers compared to healthy controls.
Collapse
Affiliation(s)
- Ni Fan
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Minling Zhang
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Ke Xu
- Department of Psychiatry, Yale University School of Medicine, 300 George Street, New Haven, CT 06510, USA
| | - Xiaoyin Ke
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China,Shenzhen Mental Health Center, 1080 Cuizhu Rd., Luohu District, Shenzhen, Guangdong 518020, China
| | - Yi Ding
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Daping Wang
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Yuping Liu
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Yuping Ning
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China
| | - Xuefeng Deng
- Guangzhou Baiyun Voluntary Drug Rehabilitation Hospital, 586 North of Baiyun Road, Baiyun District, Guangzhou, Guangdong 510440, China
| | - Hongbo He
- Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, 36 Mingxin Road, Liwan District, Guangzhou, Guangdong Province 510370, China.
| |
Collapse
|
9
|
|
10
|
Dos Santos-Rodrigues A, Pereira MR, Brito R, de Oliveira NA, Paes-de-Carvalho R. Adenosine transporters and receptors: key elements for retinal function and neuroprotection. VITAMINS AND HORMONES 2015; 98:487-523. [PMID: 25817878 DOI: 10.1016/bs.vh.2014.12.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Adenosine is an important neuroactive substance in the central nervous system, including in the retina where subclasses of adenosine receptors and transporters are expressed since early stages of development. Here, we review some evidence showing that adenosine plays important functions in the mature as well as in the developing tissue. Adenosine transporters are divided into equilibrative and concentrative, and the major transporter subtype present in the retina is the ENT1. This transporter is responsible for a bidirectional transport of adenosine and the uptake or release of this nucleoside appears to be regulated by different signaling pathways that are also controlled by activation of adenosine receptors. Adenosine receptors are also key players in retina physiology regulating a variety of functions in the mature and developing tissue. Regulation of excitatory neurotransmitter release and neuroprotection are the main functions played be adenosine in the mature tissue, while regulation of cell survival and neurogenesis are some of the functions played by adenosine in developing retina. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosine-related drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases.
Collapse
Affiliation(s)
| | - Mariana R Pereira
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Rafael Brito
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Nádia A de Oliveira
- Program of Neurosciences, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | | |
Collapse
|
11
|
The db/db mouse: a useful model for the study of diabetic retinal neurodegeneration. PLoS One 2014; 9:e97302. [PMID: 24837086 PMCID: PMC4023966 DOI: 10.1371/journal.pone.0097302] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 04/17/2014] [Indexed: 01/20/2023] Open
Abstract
Background To characterize the sequential events that are taking place in retinal neurodegeneration in a murine model of spontaneous type 2 diabetes (db/db mouse). Methods C57BLKsJ-db/db mice were used as spontaneous type 2 diabetic animal model, and C57BLKsJ-db/+ mice served as the control group. To assess the chronological sequence of the abnormalities the analysis was performed at different ages (8, 16 and 24 weeks). The retinas were evaluated in terms of morphological and functional abnormalities [electroretinography (ERG)]. Histological markers of neurodegeneration (glial activation and apoptosis) were evaluated by immunohistochemistry. In addition glutamate levels and glutamate/aspartate transporter (GLAST) expression were assessed. Furthermore, to define gene expression changes associated with early diabetic retinopathy a transcriptome analyses was performed at 8 week. Furthermore, an additional interventional study to lower blood glucose levels was performed. Results Glial activation was higher in diabetic than in non diabetic mice in all the stages (p<0.01). In addition, a progressive loss of ganglion cells and a significant reduction of neuroretinal thickness were also observed in diabetic mice. All these histological hallmarks of neurodegeneration were less pronounced at week 8 than at week 16 and 24. Significant ERG abnormalities were present in diabetic mice at weeks 16 and 24 but not at week 8. Moreover, we observed a progressive accumulation of glutamate in diabetic mice associated with an early downregulation of GLAST. Morphological and ERG abnormalities were abrogated by lowering blood glucose levels. Finally, a dysregulation of several genes related to neurotransmission and oxidative stress such as UCP2 were found at week 8. Conclusions Our results suggest that db/db mouse reproduce the features of the neurodegenerative process that occurs in the human diabetic eye. Therefore, it seems an appropriate model for investigating the underlying mechanisms of diabetes-induced retinal neurodegeneration and for testing neuroprotective drugs.
Collapse
|
12
|
Moran E, Ding L, Wang Z, Cheng R, Chen Q, Moore R, Takahashi Y, Ma JX. Protective and antioxidant effects of PPARα in the ischemic retina. Invest Ophthalmol Vis Sci 2014; 55:4568-76. [PMID: 24825105 DOI: 10.1167/iovs.13-13127] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Previous studies have demonstrated that peroxisome proliferator-activated receptor-alpha (PPARα) agonists have therapeutic effects in diabetic retinopathy, although the mechanism of action remains incompletely understood. The purpose of this study was to evaluate PPARα's protective effects in the ischemic retina, and to delineate its molecular mechanism of action. METHODS For the oxygen-induced retinopathy (OIR) model, wild-type (WT), and PPARα knockout (PPARα(-/-)) mice were exposed to 75% O₂ from postnatal day 7 (P7) to P12 and treated with the PPARα agonist fenofibric acid (Feno-FA) from P12 to P16. At P17, the effects of Feno-FA on retinal glial fibrillary acidic protein (GFAP) expression, apoptotic DNA cleavage, and TUNEL labeling were analyzed. Cultured retinal cells were exposed to CoCl₂ to induce hypoxia, and TUNEL staining and 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein dye were used to measure apoptosis and reactive oxygen species (ROS) generation. Western blotting was used to measure GFAP levels and cell signaling. RESULTS Feno-FA decreased retinal apoptosis and oxidative stress in WT but not PPARα(-/-) OIR mice. Peroxisome proliferator-activated receptor-alpha knockout OIR mice showed increased retinal cell death and glial activation in comparison to WT OIR mice. Feno-FA treatment and PPARα overexpression protected cultured retinal cells from hypoxic cell death and decreased ROS levels. Nuclear hypoxia-inducible factor-α (HIF-1α) and nicotine adenine dinucleotide phosphate oxidase-4 (Nox 4) were increased in OIR retinas and downregulated by Feno-FA in WT but not in PPARα(-/-) mice. CONCLUSIONS Peroxisome proliferator-activated receptor-alpha has a potent antiapoptotic effect in the ischemic retina. This protective effect may be mediated in part through downregulation of HIF-1α/Nox 4 and consequently alleviation of oxidative stress.
Collapse
Affiliation(s)
- Elizabeth Moran
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Lexi Ding
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhongxiao Wang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Rui Cheng
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Qian Chen
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Robert Moore
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Yusuke Takahashi
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Jian-xing Ma
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| |
Collapse
|
13
|
Ishikawa M. Abnormalities in glutamate metabolism and excitotoxicity in the retinal diseases. SCIENTIFICA 2013; 2013:528940. [PMID: 24386591 PMCID: PMC3872404 DOI: 10.1155/2013/528940] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/17/2013] [Indexed: 05/14/2023]
Abstract
In the physiological condition, glutamate acts as an excitatory neurotransmitter in the retina. However, excessive glutamate can be toxic to retinal neurons by overstimulation of the glutamate receptors. Glutamate excess is primarily attributed to perturbation in the homeostasis of the glutamate metabolism. Major pathway of glutamate metabolism consists of glutamate uptake by glutamate transporters followed by enzymatic conversion of glutamate to nontoxic glutamine by glutamine synthetase. Glutamate metabolism requires energy supply, and the energy loss inhibits the functions of both glutamate transporters and glutamine synthetase. In this review, we describe the present knowledge concerning the retinal glutamate metabolism under the physiological and pathological conditions.
Collapse
Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita Graduate University Faculty of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
- *Makoto Ishikawa:
| |
Collapse
|
14
|
Lin HJ, Huang YC, Lin JM, Wu JY, Chen LA, Tsai FJ. Association of genes on chromosome 6, GRIK2 , TMEM217 and TMEM63B (linked to MRPL14 ) with diabetic retinopathy. Ophthalmologica 2012; 229:54-60. [PMID: 23037145 DOI: 10.1159/000342616] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/09/2012] [Indexed: 01/07/2023]
Abstract
PURPOSE Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus (DM). The susceptibility genes responsible for increasing the risk for DR in type 2 diabetes (T2D) were sought in this study. METHODS A case-control study was carried out, comprising 749 unrelated T2D individuals with (n = 174) and without (n = 575) DR. Genotypic distributions of single nucleotide polymorphisms (SNPs) were determined for subjects with and without DR. RESULTS Eight chromosome 6 SNPs, having the most significant differences, were delineated: rs10499298, rs10499299, rs17827966, rs1224329, rs1150790, rs713050, rs2518344 and rs487083; all were associated with genes TMEM217, MRPL14 and GRIK2. After adjusting for the duration of DM and levels of hemoglobin A(1c), the TT genotype of rs713050, and the AG + AA genotypes of rs2518344 and rs10499298, differed significantly between those with and without DR. Haplotype analysis revealed haplotype C-A-C, residing in rs10499299, rs10499298 and rs17827966, to have significant linkage disequilibrium. CONCLUSIONS We identified new loci on chromosome 6 associated to DR; all loci showed high levels of linkage disequilibrium.
Collapse
Affiliation(s)
- Hui-Ju Lin
- Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan, ROC
| | | | | | | | | | | |
Collapse
|
15
|
Abstract
Diabetic retinopathy (DR) has been considered to be a microcirculatory disease of the retina. However, there is emerging evidence to suggest that retinal neurodegeneration is an early event in the pathogenesis of DR, which may antedate, and also participates in, the microcirculatory abnormalities that occur in DR. Therefore, the study of the underlying mechanisms that lead to neurodegeneration will be essential for identifying new therapeutic targets in the early stages of DR. Elevated levels of glutamate, oxidative stress, the overexpression of the renin-angiotensin system and the upregulation of RAGE play an essential role in the retinal neurodegeneration induced by diabetes. Finally, the balance between the neurotoxic and neuroprotective factors is crucial in determining the survival of retinal neurons. In this review we will focus on neurotrophic factors already synthesized by the retina in physiological conditions as a new therapy strategy for neuroprotection.
Collapse
Affiliation(s)
- Cristina Hernández
- CIBERDEM and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Spain
| | | |
Collapse
|