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Callan A, Jha S, Valdez L, Baldado L, Tsin A. TGF-β Signaling Pathways in the Development of Diabetic Retinopathy. Int J Mol Sci 2024; 25:3052. [PMID: 38474297 PMCID: PMC10932130 DOI: 10.3390/ijms25053052] [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: 01/23/2024] [Revised: 02/28/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Diabetic retinopathy (DR), a prevalent complication of diabetes mellitus affecting a significant portion of the global population, has long been viewed primarily as a microvascular disorder. However, emerging evidence suggests that it should be redefined as a neurovascular disease with multifaceted pathogenesis rooted in oxidative stress and advanced glycation end products. The transforming growth factor-β (TGF-β) signaling family has emerged as a major contributor to DR pathogenesis due to its pivotal role in retinal vascular homeostasis, endothelial cell barrier function, and pericyte differentiation. However, the precise roles of TGF-β signaling in DR remain incompletely understood, with conflicting reports on its impact in different stages of the disease. Additionally, the BMP subfamily within the TGF-β superfamily introduces further complexity, with BMPs exhibiting both pro- and anti-angiogenic properties. Furthermore, TGF-β signaling extends beyond the vascular realm, encompassing immune regulation, neuronal survival, and maintenance. The intricate interactions between TGF-β and reactive oxygen species (ROS), non-coding RNAs, and inflammatory mediators have been implicated in the pathogenesis of DR. This review delves into the complex web of signaling pathways orchestrated by the TGF-β superfamily and their involvement in DR. A comprehensive understanding of these pathways may hold the key to developing targeted therapies to halt or mitigate the progression of DR and its devastating consequences.
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Affiliation(s)
| | | | | | | | - Andrew Tsin
- School of Medicine, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA; (A.C.); (S.J.); (L.V.); (L.B.)
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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: 29] [Impact Index Per Article: 5.8] [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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McDowell RE, Barabas P, Augustine J, Chevallier O, McCarron P, Chen M, McGeown JG, Curtis TM. Müller glial dysfunction during diabetic retinopathy in rats is reduced by the acrolein-scavenging drug, 2-hydrazino-4,6-dimethylpyrimidine. Diabetologia 2018; 61:2654-2667. [PMID: 30112688 PMCID: PMC6223850 DOI: 10.1007/s00125-018-4707-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/09/2018] [Indexed: 01/15/2023]
Abstract
AIMS/HYPOTHESIS Recent studies suggest that abnormal function in Müller glial cells plays an important role in the pathogenesis of diabetic retinopathy. This is associated with the selective accumulation of the acrolein-derived advanced lipoxidation end-product, Nε-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine), on Müller cell proteins. The aim of the current study was to identify more efficacious acrolein-scavenging drugs and determine the effects of the most potent on Müller cell FDP-lysine accumulation and neuroretinal dysfunction during diabetes. METHODS An ELISA-based in vitro assay was optimised to compare the acrolein-scavenging abilities of a range of drugs. This identified 2-hydrazino-4,6-dimethylpyrimidine (2-HDP) as a new and potent acrolein scavenger. The ability of this agent to modify the development of diabetic retinopathy was tested in vivo. Male Sprague Dawley rats were divided into three groups: (1) non-diabetic; (2) streptozotocin-induced diabetic; and (3) diabetic treated with 2-HDP in their drinking water for the duration of diabetes. Liquid chromatography high-resolution mass spectrometry was used to detect 2-HDP reaction products in the retina. Immunohistochemistry, real-time quantitative (q)RT-PCR and electroretinography were used to assess retinal changes 3 months after diabetes induction. RESULTS 2-HDP was the most potent of six acrolein-scavenging agents tested in vitro (p < 0.05). In vivo, administration of 2-HDP reduced Müller cell accumulation of FDP-lysine at 3 months in rats rendered diabetic with streptozotocin (p < 0.001). A 2-HDP adduct was identified in the retinas of diabetic animals treated with this compound. 2-HDP supplementation was associated with reduced Müller cell gliosis (p < 0.05), reduced expression of the oxidative stress marker haem oxygenase-1 (p < 0.001) and partial normalisation of inwardly rectifying K+ channel 4.1 (Kir4.1) expression (p < 0.001 for staining in perivascular regions and the innermost region of the ganglion cell layer). Diabetes-induced retinal expression of inflammatory markers, inflammatory signalling compounds and activation of retinal microglial cells were all reduced in 2-HDP-treated animals. Retinal neurophysiological defects in diabetic animals, as indicated by changes in the electroretinogram 7 weeks after induction of diabetes, were also reduced by 2-HDP (p < 0.05-0.01 for b-wave amplitudes at flash intensities from -10 to +10 dB; p < 0.01 for time to peak of summed oscillatory potentials at +10 dB). CONCLUSIONS/INTERPRETATION These findings support the hypothesis that Müller cell accumulation of FDP-lysine plays an important role in the development of diabetic retinopathy. Our results also suggest that 2-HDP may have therapeutic potential for delaying or treating this sight-threatening complication.
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Affiliation(s)
- Rosemary E McDowell
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Peter Barabas
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Josy Augustine
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Olivier Chevallier
- Advanced Mass Spectrometry Core Technology Unit, Faculty of Medicine, Health and Life Sciences, Queen's University Belfast, Belfast, UK
| | - Philip McCarron
- Advanced Mass Spectrometry Core Technology Unit, Faculty of Medicine, Health and Life Sciences, Queen's University Belfast, Belfast, UK
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - J Graham McGeown
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Tim M Curtis
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK.
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Betts-Obregon BS, Salinas M, Oladunni D, Negrete GR, Tsin AT. Chemical Modification of Ginsenoside on Cell Viability and Cytokine Secretion. Curr Aging Sci 2016; 10:68-75. [PMID: 27659265 DOI: 10.2174/1874609809666160920125803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 08/04/2016] [Accepted: 08/12/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Rb1 is a ginsenoside steroid glycoside found exclusively in the plant Panax ginseng. In an earlier report, we showed that Rb1 increased cell proliferation and reduced VEGF (vascular endothelial growth factor) secretion by human retinal pigment epithelial (ARPE19) cells. OBJECTIVE In the present study, we hypothesized that chemical modification of Rb1 changes the level of VEGF secretion by ARPE19 cells. METHOD Three derivatives of Rb1 were chemically synthesized by hydrogenation (Rb1-H2), acetylation (Rb1-Acyl), and epoxidation (Rb1-Epoxy). Structural modifications were confirmed by 1H Nuclear Magnetic Resonance (NMR) spectra and Mass Spectrometry (MS). To test the biological activity, chemically modified compounds were added to cell culture media and incubated for 72 hours at a concentration of 250 nM at 37°C. Conditioned media were collected and cells were harvested/ counted after treatment. Viable cell numbers were determined by the trypan blue dye exclusion method and VEGF levels by Enzyme-Linked Immunosorbent Assays (ELISA). RESULTS Consistent with the prior report, results of the present study show Rb1 increased cell proliferation and decreased VEGF secretion. Similar to Rb1's effect on cell proliferation, treatment with Rb1-H2, Rb1-Acyl and Rb1-Epoxy resulted in an increase in cell numbers. In contrast to Rb1- induced decrease in VEGF secretion, treatment with Rb1-H2, Rb-Acyl and Rb1-Epoxy resulted in increased VEGF levels. CONCLUSION Chemical modifications of the ginsenoside Rb1 significantly affect the biological activity of VEGF secretion by ARPE19 cells. Additional SAR (Structure Activity Relationship) experiments will be conducted to study the detailed mechanisms by which how specific modifications of Rb1 functional groups alter biological activities.
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Affiliation(s)
| | | | | | | | - Andrew T Tsin
- Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
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Koyama R, Mizuta R. Acrolein scavengers, cysteamine and N-benzylhydroxylamine, reduces the mouse liver damage after acetaminophen overdose. J Vet Med Sci 2016; 78:1903-1905. [PMID: 27594275 PMCID: PMC5240773 DOI: 10.1292/jvms.16-0325] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our previous study suggested that the highly toxic α,β-unsaturated aldehyde acrolein, a byproduct of oxidative stress, plays a major role in acetaminophen-induced liver injury. In this study, to determine the involvement of acrolein in the liver injury and to identify novel therapeutic options for the liver damage, we examined two putative acrolein scavengers, a thiol compound cysteamine and a hydroxylamine N-benzylhydroxylamine, in cell culture and in mice. Our results showed that cysteamine and N-benzylhydroxylamine effectively prevented the cell toxicity of acrolein in vitro and acetaminophen-induced liver injury in vivo, which suggested that acrolein is involved in the liver damage, and these two drugs can be potential therapeutic options for this condition.
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Affiliation(s)
- Ryo Koyama
- Research Institute for Biomedical Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
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Friedrich U, Datta S, Schubert T, Plössl K, Schneider M, Grassmann F, Fuchshofer R, Tiefenbach KJ, Längst G, Weber BHF. Synonymous variants in HTRA1 implicated in AMD susceptibility impair its capacity to regulate TGF-β signaling. Hum Mol Genet 2015; 24:6361-73. [PMID: 26310622 DOI: 10.1093/hmg/ddv346] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/19/2015] [Indexed: 12/16/2023] Open
Abstract
High-temperature requirement A1 (HTRA1) is a secreted serine protease reported to play a role in the development of several cancers and neurodegenerative diseases. Still, the mechanism underlying the disease processes largely remains undetermined. In age-related macular degeneration (AMD), a common cause of vision impairment and blindness in industrialized societies, two synonymous polymorphisms (rs1049331:C>T, and rs2293870:G>T) in exon 1 of the HTRA1 gene were associated with a high risk to develop disease. Here, we show that the two polymorphisms result in a protein with altered thermophoretic properties upon heat-induced unfolding, trypsin accessibility and secretion behavior, suggesting unique structural features of the AMD-risk-associated HTRA1 protein. Applying MicroScale Thermophoresis and protease digestion analysis, we demonstrate direct binding and proteolysis of transforming growth factor β1 (TGF-β1) by normal HTRA1 but not the AMD-risk-associated isoform. As a consequence, both HTRA1 isoforms strongly differed in their ability to control TGF-β mediated signaling, as revealed by reporter assays targeting the TGF-β1-induced serpin peptidase inhibitor (SERPINE1, alias PAI-1) promoter. In addition, structurally altered HTRA1 led to an impaired autocrine TGF-β signaling in microglia, as measured by a strong down-regulation of downstream effectors of the TGF-β cascade such as phosphorylated SMAD2 and PAI-1 expression. Taken together, our findings demonstrate the effects of two synonymous HTRA1 variants on protein structure and protein interaction with TGF-β1. As a consequence, this leads to an impairment of TGF-β signaling and microglial regulation. Functional implications of the altered properties on AMD pathogenesis remain to be clarified.
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Affiliation(s)
- Ulrike Friedrich
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Shyamtanu Datta
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Thomas Schubert
- Department of Biochemistry, University of Regensburg, 2bind GmbH, Josef Engert Straße 13, 93053 Regensburg, Germany
| | - Karolina Plössl
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | | | - Felix Grassmann
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | | | - Klaus-Jürgen Tiefenbach
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany and
| | - Gernot Längst
- Department of Biochemistry, University of Regensburg
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany,
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Sharma K, Sharma NK, Singh R, Anand A. Exploring the role of VEGF in Indian Age related macular degeneration. Ann Neurosci 2015; 22:232-7. [PMID: 26526736 PMCID: PMC4627204 DOI: 10.5214/ans.0972.7531.220408] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/11/2015] [Accepted: 03/17/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Age related macular degeneration (AMD) is major devastating neurodegenerative disorder characterized by progressive irreversible vision loss in the elderly persons. In spite of several genetic and environmental factors, the role of VEGF and CFH predispose the pathological phenomenon in the AMD patients. PURPOSE The aim of the study was to estimate the VEGF levels in the serum of AMD patients and its correlation with co-morbidity of the participants. METHODS The study recruited the 98 AMD patients and 59 controls with proper consent of the participants as per the exclusion-inclusion criteria. The co-morbidity and socio-economic details were obtained by introducing the standard questionnaire amongst the participants. Serum levels of vascular endothelial growth factor (VEGF) was estimated by ELISA and compared with the control population of the study. The levels of VEGF in the serum of AMD patients and controls were compared with Mann-Whitney U-test. Kruskal Wallis one-way analysis of variance (ANOVA) was employed to analyze more than two variables in the study. RESULTS Elevated level of VEGF was found in AMD patients as compared to controls. Surprisingly, we did not find significant changes among wet AMD subtypes i.e. minimal, predominant and classic wet AMD. However, we have demonstrated the intravitreal anti-VEGF treatment (avastin) in AMD patients could reduce the systemic VEGF levels although it was not significant. Moreover, the heart ailment in the AMD patients could also influence the VEGF levels. CONCLUSION Our study is consistent with previous studies describing the imperative significance of VEGF in AMD pathology. However, our study did not reveal the role of VEGF in wet AMD progression but it is well established causative agent for the same. The increased levels of VEGF in heart ailment among AMD patients are significant.
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Affiliation(s)
- Kaushal Sharma
- Neuroscience Research Lab, Department of Neurology, Post Graduate institute of Medical Education and Research, Chandigarh, India
- Centre for Systems biology and Bioinformatics, Panjab University, Chandigarh, India
- *Both contributed equally to the manuscript
| | - Neel K Sharma
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, Bethesda, USA
- *Both contributed equally to the manuscript
| | - Ramandeep Singh
- Department of Ophthalmology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Akshay Anand
- Neuroscience Research Lab, Department of Neurology, Post Graduate institute of Medical Education and Research, Chandigarh, India
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Moghe A, Ghare S, Lamoreau B, Mohammad M, Barve S, McClain C, Joshi-Barve S. Molecular mechanisms of acrolein toxicity: relevance to human disease. Toxicol Sci 2015; 143:242-55. [PMID: 25628402 DOI: 10.1093/toxsci/kfu233] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acrolein, a highly reactive unsaturated aldehyde, is a ubiquitous environmental pollutant and its potential as a serious environmental health threat is beginning to be recognized. Humans are exposed to acrolein per oral (food and water), respiratory (cigarette smoke, automobile exhaust, and biocide use) and dermal routes, in addition to endogenous generation (metabolism and lipid peroxidation). Acrolein has been suggested to play a role in several disease states including spinal cord injury, multiple sclerosis, Alzheimer's disease, cardiovascular disease, diabetes mellitus, and neuro-, hepato-, and nephro-toxicity. On the cellular level, acrolein exposure has diverse toxic effects, including DNA and protein adduction, oxidative stress, mitochondrial disruption, membrane damage, endoplasmic reticulum stress, and immune dysfunction. This review addresses our current understanding of each pathogenic mechanism of acrolein toxicity, with emphasis on the known and anticipated contribution to clinical disease, and potential therapies.
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Affiliation(s)
- Akshata Moghe
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Smita Ghare
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Bryan Lamoreau
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Mohammad Mohammad
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Shirish Barve
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202 *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Craig McClain
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202 *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202 *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
| | - Swati Joshi-Barve
- *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202 *Department of Pharmacology and Toxicology, Department of Medicine and Robley Rex VAMC, Louisville, Kentucky 40202
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Grigsby J, Betts B, Vidro-Kotchan E, Culbert R, Tsin A. A possible role of acrolein in diabetic retinopathy: involvement of a VEGF/TGFβ signaling pathway of the retinal pigment epithelium in hyperglycemia. Curr Eye Res 2012; 37:1045-53. [PMID: 22906079 DOI: 10.3109/02713683.2012.713152] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE Acrolein has been implicated in retinal pigment epithelium (RPE) cell death, and has been associated with diabetic retinopathy. Our purpose was to investigate the potential effect of high glucose in influencing acrolein-mediated RPE cytokine production and cell death. We investigated the influence of the acrolein effect on ARPE-19 cells in high glucose conditions and quantified the release of transforming growth factor β (TGFβ1 and 2) and vascular endothelial growth factor (VEGF). We assessed the ability of N-benzylhydroxylamine(NBHA) as well as TGFβ pathway inhibitors SIS3 and SB431542 to prevent this effect of acrolein on ARPE-19 cells. MATERIALS AND METHODS Confluent ARPE-19 cells were treated with acrolein and/or NBHA in both 5.5 and 18.8 mM glucose conditions. Cells were also pretreated with SIS3, a specific inhibitor of the SMAD3 pathway, and SB431542, a specific inhibitor of TGFβ signaling pathway, before treating them with acrolein. Viable cells were counted and ELISAs were performed to measure the cytokines TGFβ1 and 2, and VEGF released into the conditioned media. RESULTS In ARPE-19 cells exposed to acrolein and hyperglycemia there was reduced cell viability and an increase in the cell media of VEGF, TGFβ1, and TGFβ2, which was reversed by NBHA. Acrolein/hyperglycemia-induced cell viability reduction and cytokine overproduction was also reduced by TGFβ pathway blockade. CONCLUSIONS We conclude that the effect of acrolein on the reduction of viability and VEGF increase by ARPE-19 cells in hyperglycemic media is conducted through the TGFβ signaling pathway. Our results suggest that benefits of sequestering acrolein by NBHA and the blockage of the TGFβ pathway by SB431542 and SIS3 offer suggestions as to potential useful pharmacological drug candidates for the prevention of diabetes-induced complications in the eye.
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Affiliation(s)
- Jeffery Grigsby
- University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
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