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Janapati YK, Junapudi S. Progress in experimental models to investigate the in vivo and in vitro antidiabetic activity of drugs. Animal Model Exp Med 2024. [PMID: 38837635 DOI: 10.1002/ame2.12442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 04/01/2024] [Indexed: 06/07/2024] Open
Abstract
Diabetes mellitus is one of the world's most prevalent and complex metabolic disorders, and it is a rapidly growing global public health issue. It is characterized by hyperglycemia, a condition involving a high blood glucose level brought on by deficiencies in insulin secretion, decreased activity of insulin, or both. Prolonged effects of diabetes include cardiovascular problems, retinopathy, neuropathy, nephropathy, and vascular alterations in both macro- and micro-blood vessels. In vivo and in vitro models have always been important for investigating and characterizing disease pathogenesis, identifying targets, and reviewing novel treatment options and medications. Fully understanding these models is crucial for the researchers so this review summarizes the different experimental in vivo and in vitro model options used to study diabetes and its consequences. The most popular in vivo studies involves the small animal models, such as rodent models, chemically induced diabetogens like streptozotocin and alloxan, and the possibility of deleting or overexpressing a specific gene by knockout and transgenic technologies on these animals. Other models include virally induced models, diet/nutrition induced diabetic animals, surgically induced models or pancreatectomy models, and non-obese models. Large animals or non-rodent models like porcine (pig), canine (dog), nonhuman primate, and Zebrafish models are also outlined. The in vitro models discussed are murine and human beta-cell lines and pancreatic islets, human stem cells, and organoid cultures. The other enzymatic in vitro tests to assess diabetes include assay of amylase inhibition and inhibition of α-glucosidase activity.
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Affiliation(s)
- Yasodha Krishna Janapati
- School of Pharmacy & Health Sciences, United States International University-AFRICA (USIU-A), Nairobi, Kenya
| | - Sunil Junapudi
- Department of Pharmaceutical Chemistry, Geethanjali College of Pharmacy, Keesara, India
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Dănilă AI, Ghenciu LA, Stoicescu ER, Bolintineanu SL, Iacob R, Săndesc MA, Faur AC. Aldose Reductase as a Key Target in the Prevention and Treatment of Diabetic Retinopathy: A Comprehensive Review. Biomedicines 2024; 12:747. [PMID: 38672103 PMCID: PMC11047946 DOI: 10.3390/biomedicines12040747] [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: 03/02/2024] [Revised: 03/24/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
The escalating global prevalence of diabetes mellitus (DM) over the past two decades has led to a persistent high incidence of diabetic retinopathy (DR), necessitating screening for early symptoms and proper treatment. Effective management of DR aims to decrease vision impairment by controlling modifiable risk factors including hypertension, obesity, and dyslipidemia. Moreover, systemic medications and plant-based therapy show promise in advancing DR treatment. One of the key mechanisms related to DR pathogenesis is the polyol pathway, through which aldose reductase (AR) catalyzes the conversion of glucose to sorbitol within various tissues, including the retina, lens, ciliary body and iris. Elevated glucose levels activate AR, leading to osmotic stress, advanced glycation end-product formation, and oxidative damage. This further implies chronic inflammation, vascular permeability, and angiogenesis. Our comprehensive narrative review describes the therapeutic potential of aldose reductase inhibitors in treating DR, where both synthetic and natural inhibitors have been studied in recent decades. Our synthesis aims to guide future research and clinical interventions in DR management.
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Affiliation(s)
- Alexandra-Ioana Dănilă
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
| | - Laura Andreea Ghenciu
- Department of Functional Sciences, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Emil Robert Stoicescu
- Doctoral School, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania
- Department of Radiology and Medical Imaging, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- Research Center for Pharmaco-Toxicological Evaluations, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Sorin Lucian Bolintineanu
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
| | - Roxana Iacob
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
- Doctoral School, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania
| | - Mihai-Alexandru Săndesc
- Department of Orthopedics and Traumatology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
| | - Alexandra Corina Faur
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
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Glass J, Robinson RL, Greenway G, Jones G, Sharma S. Diabetic Müller-Glial-Cell-Specific Il6ra Knockout Mice Exhibit Accelerated Retinal Functional Decline and Thinning of the Inner Nuclear Layer. Invest Ophthalmol Vis Sci 2023; 64:1. [PMID: 38038619 PMCID: PMC10697173 DOI: 10.1167/iovs.64.15.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
Purpose Interleukin-6 (IL-6) is implicated in the pathology of diabetic retinopathy (DR). IL-6 trans-signaling via soluble IL-6 receptor (IL-6R) is primarily responsible for its pro-inflammatory functions, whereas cis-signaling via membrane-bound IL-6R is anti-inflammatory. Using a Müller-glial-cell-specific Il6ra-/- mouse, we examined how loss of IL-6 cis-signaling in Müller glial cells (MGCs) affected retinal thinning and electroretinography (ERG) response over 9 months of diabetes. Methods Diabetes was induced in wildtype and knockout mice with streptozotocin (40 mg/kg, daily for 5 days). Spectral domain optical coherence tomography (SD-OCT), ERG, and fundoscopy/fluorescein angiography (FA) were assessed at 2, 6, and 9 months of diabetes. MGCs and bipolar neurons were examined in retinal tissue sections by immunofluorescence. Results Diabetic MGC Il6ra-/- mice had significantly thinner retinas than diabetic wildtype mice at 2 (-7.6 µm), 6 (-12.0 µm), and 9 months (-5.0 µm) of diabetes, as well as significant thinning of the inner nuclear layer (INL). Diabetic MGC Il6ra-/- mice also showed a reduction in scotopic B-wave amplitude and B-wave/A-wave ratio earlier than wildtype diabetic mice. In retinal sections, we found a decrease in bipolar neuronal marker PKCα only in diabetic MGC Il6ra-/- mice, which was significantly lower than both controls and diabetic wildtype mice. Glutamine synthetase, a Müller cell marker, was reduced in both wildtype and MGC Il6ra-/- diabetic mice compared to their respective controls. Conclusions IL-6 cis-signaling in MGCs contributes to maintenance of the INL in diabetes, and loss of the IL-6 receptor reduces MGC-mediated neuroprotection of bipolar neurons in the diabetic retina.
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Affiliation(s)
- Joshua Glass
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
| | - Rebekah L. Robinson
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
| | - Grace Greenway
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
| | - Garrett Jones
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
| | - Shruti Sharma
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Augusta University, Augusta, Georgia, United States
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Kern TS, Du Y, Tang J, Lee CA, Liu H, Dreffs A, Leinonen H, Antonetti DA, Palczewski K. Regulation of Adrenergic, Serotonin, and Dopamine Receptors to Inhibit Diabetic Retinopathy: Monotherapies versus Combination Therapies. Mol Pharmacol 2021; 100:470-479. [PMID: 34393108 PMCID: PMC9175131 DOI: 10.1124/molpharm.121.000278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/03/2021] [Indexed: 11/22/2022] Open
Abstract
We compared monotherapies and combinations of therapies that regulate G-protein-coupled receptors (GPCRs) with respect to their abilities to inhibit early stages of diabetic retinopathy (DR) in streptozotocin-diabetic mice. Metoprolol (MTP; 0.04-1.0 mg/kg b.wt./day), bromocriptine (BRM; 0.01-0.1 mg/kg b.wt./day), doxazosin (DOX; 0.01-1.0 mg/kg b.wt./day), or tamsulosin (TAM; 0.05-0.25 mg/kg b.wt./day) were injected individually daily for 2 months in dose-response studies to assess their effects on the diabetes-induced increases in retinal superoxide and leukocyte-mediated cytotoxicity against vascular endothelial cells, both of which abnormalities have been implicated in the development of DR. Each of the individual drugs inhibited the diabetes-induced increase in retinal superoxide at the higher concentrations tested, but the inhibition was lost at lower doses. To determine whether combination therapies had superior effects over individual drugs, we intentionally selected for each drug a low dose that had little or no effect on the diabetes-induced retinal superoxide for use separately or in combinations in 8-month studies of retinal function, vascular permeability, and capillary degeneration in diabetes. At the low doses used, combinations of the drugs generally were more effective than individual drugs, but the low-dose MTP alone totally inhibited diabetes-induced reduction in a vision task, BRM or DOX alone totally inhibited the vascular permeability defect, and DOX alone totally inhibited diabetes-induced degeneration of retinal capillaries. Although low-dose MTP, BRM, DOX, or TAM individually had beneficial effects on some endpoints, combination of the therapies better inhibited the spectrum of DR lesions evaluated. SIGNIFICANCE STATEMENT: The pathogenesis of early stages of diabetic retinopathy remains incompletely understood, but multiple different cell types are believed to be involved in the pathogenic process. We have compared the effects of monotherapies to those of combinations of drugs that regulate GPCR signaling pathways with respect to their relative abilities to inhibit the development of early diabetic retinopathy.
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Affiliation(s)
- Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Yunpeng Du
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Jie Tang
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Chieh Allen Lee
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Haitao Liu
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Alyssa Dreffs
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Henri Leinonen
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - David A Antonetti
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
| | - Krzysztof Palczewski
- Center for Translational Vision Research, Gavin Herbert Eye Institute (T.S.K., Y.D., H.L., K.P.), Department of Physiology and Biophysics (K.P.), and Department of Chemistry (K.P.), University of California-Irvine, Irvine, California; Veterans Administration Medical Center, Long Beach Healthcare System, Research Service, Long Beach, California (T.S.K.); Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio (J.T., C.A.L.); and Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan (A.D., D.A.A.)
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Yan LJ. NADH/NAD + Redox Imbalance and Diabetic Kidney Disease. Biomolecules 2021; 11:biom11050730. [PMID: 34068842 PMCID: PMC8153586 DOI: 10.3390/biom11050730] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 12/11/2022] Open
Abstract
Diabetic kidney disease (DKD) is a common and severe complication of diabetes mellitus. If left untreated, DKD can advance to end stage renal disease that requires either dialysis or kidney replacement. While numerous mechanisms underlie the pathogenesis of DKD, oxidative stress driven by NADH/NAD+ redox imbalance and mitochondrial dysfunction have been thought to be the major pathophysiological mechanism of DKD. In this review, the pathways that increase NADH generation and those that decrease NAD+ levels are overviewed. This is followed by discussion of the consequences of NADH/NAD+ redox imbalance including disruption of mitochondrial homeostasis and function. Approaches that can be applied to counteract DKD are then discussed, which include mitochondria-targeted antioxidants and mimetics of superoxide dismutase, caloric restriction, plant/herbal extracts or their isolated compounds. Finally, the review ends by pointing out that future studies are needed to dissect the role of each pathway involved in NADH-NAD+ metabolism so that novel strategies to restore NADH/NAD+ redox balance in the diabetic kidney could be designed to combat DKD.
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Affiliation(s)
- Liang-Jun Yan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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Gerardi G, Cavia-Saiz M, Muñiz P. From winery by-product to healthy product: bioavailability, redox signaling and oxidative stress modulation by wine pomace product. Crit Rev Food Sci Nutr 2021; 62:7427-7448. [PMID: 33951976 DOI: 10.1080/10408398.2021.1914542] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The wine pomace is the main winery by-products that suppose an economic and environmental problem and their use as a functional ingredient are being increasingly recognized as a good and inexpensive source of bioactive compounds. In this sense, it is known the potential health properties of wine pomace products in the prevention of disorders associated with oxidative stress and inflammation such as endothelial dysfunction, hypertension, hyperglycemia, diabetes, obesity. Those effects are due to the bioactive compounds of wine pomace and the mechanisms concern especially modulation of antioxidant/prooxidant activity, improvement of nitric oxide bioavailability, reduction of pro-inflammatory cytokines and modulation of antioxidant/inflammatory signal pathways. This review mainly summarizes the mechanisms of wine pomace products as modulators of oxidative status involved in cell pathologies as well as their potential therapeutic use for cardiovascular diseases. For this purpose, the review provides an overview of the findings related to the wine pomace bioactive compounds profile, their bioavailability and the action mechanisms for maintaining the redox cell balance involved in health benefits. The review suggests an important role for wine pomace product in cardiovascular diseases prevention and their regular food intake may attenuate the development and progression of comorbidities associated with cardiovascular diseases.
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Affiliation(s)
- Gisela Gerardi
- Department of Biotechnology and Food Science, Faculty of Sciences, University of Burgos, Burgos, Spain
| | - Mónica Cavia-Saiz
- Department of Biotechnology and Food Science, Faculty of Sciences, University of Burgos, Burgos, Spain
| | - Pilar Muñiz
- Department of Biotechnology and Food Science, Faculty of Sciences, University of Burgos, Burgos, Spain
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Pruss KM, Sonnenburg JL. C. difficile exploits a host metabolite produced during toxin-mediated disease. Nature 2021; 593:261-265. [PMID: 33911281 PMCID: PMC9067157 DOI: 10.1038/s41586-021-03502-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 03/26/2021] [Indexed: 02/02/2023]
Abstract
Several enteric pathogens can gain specific metabolic advantages over other members of the microbiota by inducing host pathology and inflammation. The pathogen Clostridium difficile is responsible for a toxin-mediated colitis that causes 450,000 infections and 15,000 deaths in the United States each year1; however, the molecular mechanisms by which C. difficile benefits from this pathology remain unclear. To understand how the metabolism of C. difficile adapts to the inflammatory conditions that its toxins induce, here we use RNA sequencing to define, in a mouse model, the metabolic states of wild-type C. difficile and of an isogenic mutant that lacks toxins. By combining bacterial and mouse genetics, we demonstrate that C. difficile uses sorbitol derived from both diet and host. Host-derived sorbitol is produced by the enzyme aldose reductase, which is expressed by diverse immune cells and is upregulated during inflammation-including during toxin-mediated disease induced by C. difficile. This work highlights a mechanism by which C. difficile can use a host-derived nutrient that is generated during toxin-induced disease by an enzyme that has not previously been associated with infection.
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Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease. Antioxidants (Basel) 2020; 9:antiox9100905. [PMID: 32977483 PMCID: PMC7598160 DOI: 10.3390/antiox9100905] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy (DR), a common chronic complication of diabetes mellitus and the leading cause of vision loss in the working-age population, is clinically defined as a microvascular disease that involves damage of the retinal capillaries with secondary visual impairment. While its clinical diagnosis is based on vascular pathology, DR is associated with early abnormalities in the electroretinogram, indicating alterations of the neural retina and impaired visual signaling. The pathogenesis of DR is complex and likely involves the simultaneous dysregulation of multiple metabolic and signaling pathways through the retinal neurovascular unit. There is evidence that microvascular disease in DR is caused in part by altered energetic metabolism in the neural retina and specifically from signals originating in the photoreceptors. In this review, we discuss the main pathogenic mechanisms that link alterations in neural retina bioenergetics with vascular regression in DR. We focus specifically on the recent developments related to alterations in mitochondrial metabolism including energetic substrate selection, mitochondrial function, oxidation-reduction (redox) imbalance, and oxidative stress, and critically discuss the mechanisms of these changes and their consequences on retinal function. We also acknowledge implications for emerging therapeutic approaches and future research directions to find novel mitochondria-targeted therapeutic strategies to correct bioenergetics in diabetes. We conclude that retinal bioenergetics is affected in the early stages of diabetes with consequences beyond changes in ATP content, and that maintaining mitochondrial integrity may alleviate retinal disease.
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Nahomi RB, Nam MH, Rankenberg J, Rakete S, Houck JA, Johnson GC, Stankowska DL, Pantcheva MB, MacLean PS, Nagaraj RH. Kynurenic Acid Protects Against Ischemia/Reperfusion-Induced Retinal Ganglion Cell Death in Mice. Int J Mol Sci 2020; 21:ijms21051795. [PMID: 32151061 PMCID: PMC7084183 DOI: 10.3390/ijms21051795] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/21/2020] [Accepted: 03/02/2020] [Indexed: 12/17/2022] Open
Abstract
Background: Glaucoma is an optic neuropathy and involves the progressive degeneration of retinal ganglion cells (RGCs), which leads to blindness in patients. We investigated the role of the neuroprotective kynurenic acid (KYNA) in RGC death against retinal ischemia/reperfusion (I/R) injury. Methods: We injected KYNA intravenously or intravitreally to mice. We generated a knockout mouse strain of kynurenine 3-monooxygenase (KMO), an enzyme in the kynurenine pathway that produces neurotoxic 3-hydroxykynurenine. To test the effect of mild hyperglycemia on RGC protection, we used streptozotocin (STZ) induced diabetic mice. Retinal I/R injury was induced by increasing intraocular pressure for 60 min followed by reperfusion and RGC numbers were counted in the retinal flat mounts. Results: Intravenous or intravitreal administration of KYNA protected RGCs against I/R injury. The I/R injury caused a greater loss of RGCs in wild type than in KMO knockout mice. KMO knockout mice had mildly higher levels of fasting blood glucose than wild type mice. Diabetic mice showed significantly lower loss of RGCs when compared with non-diabetic mice subjected to I/R injury. Conclusion: Together, our study suggests that the absence of KMO protects RGCs against I/R injury, through mechanisms that likely involve higher levels of KYNA and glucose.
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Affiliation(s)
- Rooban B. Nahomi
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
- Correspondence: (R.B.N.); (R.H.N.); Tel.: +1-303-724-8824 (R.H.N.)
| | - Mi-Hyun Nam
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Johanna Rankenberg
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Stefan Rakete
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Julie A. Houck
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Ginger C. Johnson
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Dorota L. Stankowska
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107, USA;
| | - Mina B. Pantcheva
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
| | - Paul S. MacLean
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado, Aurora, CO 80045, USA; (J.A.H.); (G.C.J.); (P.S.M.)
| | - Ram H. Nagaraj
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, University of Colorado, Aurora, CO 80045, USA; (M.-H.N.); (J.R.); (S.R.); (M.B.P.)
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO 80045, USA
- Correspondence: (R.B.N.); (R.H.N.); Tel.: +1-303-724-8824 (R.H.N.)
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Kern TS, Antonetti DA, Smith LEH. Pathophysiology of Diabetic Retinopathy: Contribution and Limitations of Laboratory Research. Ophthalmic Res 2019; 62:196-202. [PMID: 31362288 DOI: 10.1159/000500026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 12/11/2022]
Abstract
Preclinical models of diabetic retinopathy are indispensable in the drug discovery and development of new therapies. They are, however, imperfect facsimiles of diabetic retinopathy in humans. This chapter discusses the advantages, limitations, and physiological and pathological relevance of preclinical models of diabetic retinopathy. The judicious interpretation and extrapolation of data derived from these models to humans and a correspondingly greater emphasis placed on translational medical research in early-stage clinical trials are essential to more successfully inhibit the development and progression of diabetic retinopathy in the future.
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Affiliation(s)
- Timothy S Kern
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA, .,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA,
| | - David A Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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11
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Song J, Yang X, Yan LJ. Role of pseudohypoxia in the pathogenesis of type 2 diabetes. HYPOXIA 2019; 7:33-40. [PMID: 31240235 PMCID: PMC6560198 DOI: 10.2147/hp.s202775] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/23/2019] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes is caused by persistent high blood glucose, which is known as diabetic hyperglycemia. This hyperglycemic situation, when not controlled, can overproduce NADH and lower nicotinamide adenine dinucleotide (NAD), thereby creating NADH/NAD redox imbalance and leading to cellular pseudohypoxia. In this review, we discussed two major enzymatic systems that are activated by diabetic hyperglycemia and are involved in creation of this pseudohypoxic condition. One system is aldose reductase in the polyol pathway, and the other is poly (ADP ribose) polymerase. While aldose reductase drives overproduction of NADH, PARP could in contrast deplete NAD. Therefore, activation of the two pathways underlies the major mechanisms of NADH/NAD redox imbalance and diabetic pseudohypoxia. Consequently, reductive stress occurs, followed by oxidative stress and eventual cell death and tissue dysfunction. Additionally, fructose formed in the polyol pathway can also cause metabolic syndrome such as hypertension and nonalcoholic fatty liver disease. Moreover, pseudohypoxia can also lower sirtuin protein contents and induce protein acetylation which can impair protein function. Finally, we discussed the possibility of using nicotinamide riboside, an NAD precursor, as a promising therapeutic agent for restoring NADH/NAD redox balance and for preventing the occurrence of diabetic pseudohypoxia.
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Affiliation(s)
- Jing Song
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA.,School of Public Health, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Xiaojuan Yang
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA.,Department of Geriatrics, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, People's Republic of China
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
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12
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Chang KC, Shieh B, Petrash JM. Role of aldose reductase in diabetes-induced retinal microglia activation. Chem Biol Interact 2019; 302:46-52. [PMID: 30682331 DOI: 10.1016/j.cbi.2019.01.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/03/2019] [Accepted: 01/22/2019] [Indexed: 01/18/2023]
Abstract
Diabetes-induced hyperglycemia plays a key pathogenic role in degenerative retinal diseases. In diabetic hyperglycemia, aldose reductase (AR) is elevated and linked to the pathogenesis of diabetic retinopathy (DR) and cataract. Retinal microglia (RMG), the resident immune cells in the retina, are thought to contribute to the proinflammatory phenotype in the diabetic eye. However, we have a limited understanding of the potential role of AR expressed in RMG as a mediator of inflammation in the diabetic retina. Glycated proteins accumulate in diabetes, including Amadori-glycated albumin (AGA) which has been shown to induce a proinflammatory phenotype in various tissues. In this study, we investigated the ability of AGA to stimulate inflammatory changes to RMG and macrophages, and whether AR plays a role in this process. In macrophages, treatment with an AR inhibitor (Sorbinil) or genetic knockdown of AR lowered AGA-induced TNF-α secretion (56% and 40%, respectively) as well as cell migration. In a mouse RMG model, AR inhibition attenuated AGA-induced TNF-α secretion and cell migration (67% and 40%, respectively). To further mimic the diabetic milieu in retina, we cultured RMG under conditions of hypoxia and observed the induction of TNF-α and VEGF protein expression. Downregulation of AR in either a pharmacological or genetic manner prevented hypoxia-induced TNF-α and VEGF expression. In our animal study, increased numbers of RMG observed in streptozotocin (STZ)-induced diabetic retina was substantially lower when diabetes was induced in AR knockout mice. Thus, in vitro and in vivo studies demonstrated that AR is involved in diabetes-induced RMG activation, providing a rationale for targeting AR as a therapeutic strategy for DR.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Biehuoy Shieh
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - J Mark Petrash
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA; Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA.
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13
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Nahomi RB, Sampathkumar S, Myers AM, Elghazi L, Smith DG, Tang J, Lee CA, Kern TS, Nagaraj RH, Fort PE. The Absence of Indoleamine 2,3-Dioxygenase Inhibits Retinal Capillary Degeneration in Diabetic Mice. Invest Ophthalmol Vis Sci 2019; 59:2042-2053. [PMID: 29677366 PMCID: PMC5908388 DOI: 10.1167/iovs.17-22702] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Loss of retinal capillary endothelial cells and pericytes through apoptosis is an early event in diabetic retinopathy (DR). Inflammatory pathways play a role in early DR, yet the biochemical mechanisms are poorly understood. In this study, we investigated the role of indoleamine 2,3-dioxygenase (IDO), an inflammatory cytokine-inducible enzyme, on retinal endothelial apoptosis and capillary degeneration in the diabetic retina. Methods IDO was detected in human and mouse retinas by immunohistochemistry or Western blotting. Interferon-γ (IFN-γ) levels were measured by ELISA. IDO levels were measured in human retinal capillary endothelial cells (HREC) cultured in the presence of IFN-γ ± 25 mM D-glucose. Reactive oxygen species (ROS) were measured using CM-H2DCFDA dye and apoptosis was measured by cleaved caspase-3. The role of IDO in DR was determined in IDO knockout (IDO−/−) mice with streptozotocin-induced diabetes. Results The IDO and IFN-γ levels were higher in human diabetic retinas with retinopathy relative to nondiabetic retinas. Immunohistochemical data showed that IDO is present in capillary endothelial cells. IFN-γ upregulated the IDO and ROS levels in HREC. The blockade of either IDO or kynurenine monooxygenase led to inhibition of ROS in HREC. Apoptosis through this pathway was inhibited by an ROS scavenger, TEMPOL. Capillary degeneration was significantly reduced in diabetic IDO−/− mice compared to diabetic wild-type mice. Conclusions The results suggest that the kynurenine pathway plays an important role in the inflammatory damage in the diabetic retina and could be a new therapeutic target for the treatment of DR.
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Affiliation(s)
- Rooban B Nahomi
- Departments of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States.,Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, United States
| | - Sruthi Sampathkumar
- Departments of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Angela M Myers
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Lynda Elghazi
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Dawn G Smith
- Departments of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Jie Tang
- Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - C Allen Lee
- Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Timothy S Kern
- Departments of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States.,Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Ram H Nagaraj
- Departments of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States.,Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, United States
| | - Patrice E Fort
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
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14
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Abstract
In diabetes mellitus, the polyol pathway is highly active and consumes approximately 30% glucose in the body. This pathway contains 2 reactions catalyzed by aldose reductase (AR) and sorbitol dehydrogenase, respectively. AR reduces glucose to sorbitol at the expense of NADPH, while sorbitol dehydrogenase converts sorbitol to fructose at the expense of NAD+, leading to NADH production. Consumption of NADPH, accumulation of sorbitol, and generation of fructose and NADH have all been implicated in the pathogenesis of diabetes and its complications. In this review, the roles of this pathway in NADH/NAD+ redox imbalance stress and oxidative stress in diabetes are highlighted. A potential intervention using nicotinamide riboside to restore redox balance as an approach to fighting diabetes is also discussed.
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Affiliation(s)
- Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
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15
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Loss of CD40 attenuates experimental diabetes-induced retinal inflammation but does not protect mice from electroretinogram defects. Vis Neurosci 2018; 34:E009. [PMID: 28965505 DOI: 10.1017/s0952523817000074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chronic low grade inflammation is considered to contribute to the development of experimental diabetic retinopathy (DR). We recently demonstrated that lack of CD40 in mice ameliorates the upregulation of inflammatory molecules in the diabetic retina and prevented capillary degeneration, a hallmark of experimental diabetic retinopathy. Herein, we investigated the contribution of CD40 to diabetes-induced reductions in retinal function via the electroretinogram (ERG) to determine if inflammation plays a role in the development of ERG defects associated with diabetes. We demonstrate that diabetic CD40-/- mice are not protected from reduction to the ERG b-wave despite failing to upregulate inflammatory molecules in the retina. Our data therefore supports the hypothesis that retinal dysfunction found in diabetics occurs independent of the induction of inflammatory processes.
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16
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Niimi N, Yako H, Takaku S, Kato H, Matsumoto T, Nishito Y, Watabe K, Ogasawara S, Mizukami H, Yagihashi S, Chung SK, Sango K. A spontaneously immortalized Schwann cell line from aldose reductase-deficient mice as a useful tool for studying polyol pathway and aldehyde metabolism. J Neurochem 2018; 144:710-722. [DOI: 10.1111/jnc.14277] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/27/2017] [Accepted: 12/03/2017] [Indexed: 01/16/2023]
Affiliation(s)
- Naoko Niimi
- Diabetic Neuropathy Project; Department of Sensory and Motor Systems; Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Hideji Yako
- Diabetic Neuropathy Project; Department of Sensory and Motor Systems; Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Shizuka Takaku
- Diabetic Neuropathy Project; Department of Sensory and Motor Systems; Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Hiroshi Kato
- Sumitomo Dainippon Pharma Co., Ltd.; Osaka Japan
| | | | - Yasumasa Nishito
- Basic Technology Research Center; Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
| | - Kazuhiko Watabe
- Department of Medical Technology; Faculty of Health Sciences; Kyorin University; Tokyo Japan
| | - Saori Ogasawara
- Department of Pathology and Molecular Medicine; Hirosaki University Graduate School of Medicine; Hirosaki Japan
| | - Hiroki Mizukami
- Department of Pathology and Molecular Medicine; Hirosaki University Graduate School of Medicine; Hirosaki Japan
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine; Hirosaki University Graduate School of Medicine; Hirosaki Japan
| | - Sookja K. Chung
- School of Biomedical Sciences; Research Center of Heart, Brain, Hormone and Healthy Aging and State Key Laboratory of Pharmaceutical Biotechnology; The University of Hong Kong; Hong Kong SAR China
| | - Kazunori Sango
- Diabetic Neuropathy Project; Department of Sensory and Motor Systems; Tokyo Metropolitan Institute of Medical Science; Tokyo Japan
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17
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Chang KC, Petrash JM. Aldo-Keto Reductases: Multifunctional Proteins as Therapeutic Targets in Diabetes and Inflammatory Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1032:173-202. [PMID: 30362099 DOI: 10.1007/978-3-319-98788-0_13] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aldose reductase (AR) is an NADPH-dependent aldo-keto reductase that has been shown to be involved in the pathogenesis of several blinding diseases such as uveitis, diabetic retinopathy (DR) and cataract. However, possible mechanisms linking the action of AR to these diseases are not well understood. As DR and cataract are among the leading causes of blindness in the world, there is an urgent need to explore therapeutic strategies to prevent or delay their onset. Studies with AR inhibitors and gene-targeted mice have demonstrated that the action of AR is also linked to cancer onset and progression. In this review we examine possible mechanisms that relate AR to molecular signaling cascades and thus explain why AR inhibition is an effective strategy against colon cancer as well as diseases of the eye such as uveitis, cataract, and retinopathy.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, School of Medicine, University of Colorado, Aurora, CO, USA.,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - J Mark Petrash
- Department of Ophthalmology, School of Medicine, University of Colorado, Aurora, CO, USA. .,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA.
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18
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Wu J, Luo X, Thangthaeng N, Sumien N, Chen Z, Rutledge MA, Jing S, Forster MJ, Yan LJ. Pancreatic mitochondrial complex I exhibits aberrant hyperactivity in diabetes. Biochem Biophys Rep 2017; 11:119-129. [PMID: 28868496 PMCID: PMC5580358 DOI: 10.1016/j.bbrep.2017.07.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 07/13/2017] [Accepted: 07/18/2017] [Indexed: 12/28/2022] Open
Abstract
It is well established that NADH/NAD+ redox balance is heavily perturbed in diabetes, and the NADH/NAD+ redox imbalance is a major source of oxidative stress in diabetic tissues. In mitochondria, complex I is the only site for NADH oxidation and NAD+ regeneration and is also a major site for production of mitochondrial reactive oxygen species (ROS). Yet how complex I responds to the NADH/NAD+ redox imbalance and any potential consequences of such response in diabetic pancreas have not been investigated. We report here that pancreatic mitochondrial complex I showed aberrant hyperactivity in either type 1 or type 2 diabetes. Further studies focusing on streptozotocin (STZ)-induced diabetes indicate that complex I hyperactivity could be attenuated by metformin. Moreover, complex I hyperactivity was accompanied by increased activities of complexes II to IV, but not complex V, suggesting that overflow of NADH via complex I in diabetes could be diverted to ROS production. Indeed in diabetic pancreas, ROS production and oxidative stress increased and mitochondrial ATP production decreased, which can be attributed to impaired pancreatic mitochondrial membrane potential that is responsible for increased cell death. Additionally, cellular defense systems such as glucose 6-phosphate dehydrogenase, sirtuin 3, and NQO1 were found to be compromised in diabetic pancreas. Our findings point to the direction that complex I aberrant hyperactivity in pancreas could be a major source of oxidative stress and β cell failure in diabetes. Therefore, inhibiting pancreatic complex I hyperactivity and attenuating its ROS production by various means in diabetes might serve as a promising approach for anti-diabetic therapies.
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Affiliation(s)
- Jinzi Wu
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Xiaoting Luo
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
- Department of Biochemistry and Molecular Biology, Gannan Medical University, Ganzhou, Jiangxi Province 341000, China
| | - Nopporn Thangthaeng
- Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Nathalie Sumien
- Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Zhenglan Chen
- Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Margaret A. Rutledge
- Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Siqun Jing
- College of Life Sciences and Technology, Xinjiang University, Urumqi, Xinjiang 830046, China
| | - Michael J. Forster
- Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
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19
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Liu H, Tang J, Du Y, Saadane A, Tonade D, Samuels I, Veenstra A, Palczewski K, Kern TS. Photoreceptor Cells Influence Retinal Vascular Degeneration in Mouse Models of Retinal Degeneration and Diabetes. Invest Ophthalmol Vis Sci 2017; 57:4272-81. [PMID: 27548901 PMCID: PMC5015983 DOI: 10.1167/iovs.16-19415] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose Loss of photoreceptor cells is associated with retinal vascular degeneration in retinitis pigmentosa, whereas the presence of photoreceptor cells is implicated in vascular degeneration in diabetic retinopathy. To investigate how both the absence and presence of photoreceptors could damage the retinal vasculature, we compared two mouse models of photoreceptor degeneration (opsin−/− and RhoP23H/P23H ) and control C57Bl/5J mice, each with and without diabetes. Methods Retinal thickness, superoxide, expression of inflammatory proteins, ERG and optokinetic responses, leukocyte cytotoxicity, and capillary degeneration were evaluated at 1 to 10 months of age using published methods. Results Retinal photoreceptor cells degenerated completely in the opsin mutants by 2 to 4 months of age, and visual function subsided correspondingly. Retinal capillary degeneration was substantial while photoreceptors were still present, but slowed after the photoreceptors degenerated. Diabetes did not further exacerbate capillary degeneration in these models of photoreceptor degeneration, but did cause capillary degeneration in wild-type animals. Photoreceptor cells, however, did not degenerate in wild-type diabetic mice, presumably because the stress responses in these cells were less than in the opsin mutants. Retinal superoxide and leukocyte damage to retinal endothelium contributed to the degeneration of retinal capillaries in diabetes, and leukocyte-mediated damage was increased in both opsin mutants during photoreceptor cell degeneration. Conclusions Photoreceptor cells affect the integrity of the retinal microvasculature. Deterioration of retinal capillaries in opsin mutants was appreciable while photoreceptor cells were present and stressed, but was less after photoreceptors degenerated. This finding proves relevant to diabetes, where persistent stress in photoreceptors likewise contributes to capillary degeneration.
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Affiliation(s)
- Haitao Liu
- Department of Medicine Case Western Reserve University, Cleveland, Ohio, United States
| | - Jie Tang
- Department of Medicine Case Western Reserve University, Cleveland, Ohio, United States
| | - Yunpeng Du
- Department of Medicine Case Western Reserve University, Cleveland, Ohio, United States
| | - Aicha Saadane
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, Ohio, United States
| | - Deoye Tonade
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Ivy Samuels
- Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, United States
| | - Alex Veenstra
- Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, United States
| | - Krzysztof Palczewski
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Timothy S Kern
- Department of Medicine Case Western Reserve University, Cleveland, Ohio, United States 2Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, Ohio, United States 3Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, Ohio, United States 4Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, United States
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20
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Senthilkumari S, Sharmila R, Chidambaranathan G, Vanniarajan A. Epalrestat, an Aldose Reductase Inhibitor Prevents Glucose-Induced Toxicity in Human Retinal Pigment Epithelial Cells In Vitro. J Ocul Pharmacol Ther 2017; 33:34-41. [DOI: 10.1089/jop.2016.0103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
| | - Rajendran Sharmila
- Department of Ocular Pharmacology, Dr. G. Venkataswamy Eye Research Institute, Madurai, India
| | | | - Ayyasamy Vanniarajan
- Molecular Genetics, Aravind Medical Research Foundation (AMRF), Dr. G. Venkataswamy Eye Research Institute, Madurai, India
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21
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Sorrentino FS, Allkabes M, Salsini G, Bonifazzi C, Perri P. The importance of glial cells in the homeostasis of the retinal microenvironment and their pivotal role in the course of diabetic retinopathy. Life Sci 2016; 162:54-9. [PMID: 27497914 DOI: 10.1016/j.lfs.2016.08.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 07/24/2016] [Accepted: 08/02/2016] [Indexed: 01/18/2023]
Abstract
Diabetic retinopathy (DR) is a remarkable microvascular complication of diabetes and it has been considered the leading cause of legal blindness in working-age adults in the world. Several overlapping and interrelated molecular pathways are involved in the development of this disease. DR is staged into different levels of severity, from the nonproliferative to the advanced proliferative form. Over the years the progression of DR evolves through a series of changes involving distinct types of specialized cells: neural, vascular and glial. Prior to the clinically observable vascular complications, hyperglycemia and inflammation affect retinal glial cells which undergo a wide range of structural and functional alterations. In this review, we provide an overview of the status of macroglia and microglia in the course of DR, trying to briefly take into account the complex biochemical mechanisms that affect the intimate relationship among neuroretina, vessels and glial cells.
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Affiliation(s)
| | - Michael Allkabes
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
| | - Giulia Salsini
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
| | - Claudio Bonifazzi
- Department of Biomedical and Surgical Sciences, Section of Human Physiology, University of Ferrara, Ferrara, Italy
| | - Paolo Perri
- Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy
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22
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Chang KC, Li L, Sanborn TM, Shieh B, Lenhart P, Ammar D, LaBarbera DV, Petrash JM. Characterization of Emodin as a Therapeutic Agent for Diabetic Cataract. JOURNAL OF NATURAL PRODUCTS 2016; 79:1439-44. [PMID: 27140653 PMCID: PMC5578730 DOI: 10.1021/acs.jnatprod.6b00185] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Aldose reductase (AR) in the lens plays an important role in the pathogenesis of diabetic cataract (DC) by contributing to osmotic and oxidative stress associated with accelerated glucose metabolism through the polyol pathway. Therefore, inhibition of AR in the lens may hold the key to prevent DC formation. Emodin, a bioactive compound isolated from plants, has been implicated as a therapy for diabetes. However, its inhibitory activity against AR remains unclear. Our results showed that emodin has good selectively inhibitory activity against AR (IC50 = 2.69 ± 0.90 μM) but not other aldo-keto reductases and is stable at 37 °C for at least 7 days. Enzyme kinetic studies demonstrated an uncompetitive inhibition against AR with a corresponding inhibition constant of 2.113 ± 0.095 μM. In in vivo studies, oral administration of emodin reduced the incidence and severity of morphological markers of cataract in lenses of AR transgenic mice. Computational modeling of the AR-NADP(+)-emodin ternary complex indicated that the 3-hydroxy group of emodin plays an essential role by interacting with Ser302 through hydrogen bonding in the specificity pocket of AR. All the findings above provide encouraging evidence for emodin as a potential therapeutic agent to prevent cataract in diabetic patients.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Linfeng Li
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Theresa M. Sanborn
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Biehuoy Shieh
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Patricia Lenhart
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - David Ammar
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - Daniel V. LaBarbera
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
| | - J. Mark Petrash
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045, United States
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23
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Consumption of polyphenol-rich Morus alba leaves extract attenuates early diabetic retinopathy: the underlying mechanism. Eur J Nutr 2016; 56:1671-1684. [DOI: 10.1007/s00394-016-1214-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 03/31/2016] [Indexed: 01/22/2023]
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24
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Chang KC, Shieh B, Petrash JM. Aldose reductase mediates retinal microglia activation. Biochem Biophys Res Commun 2016; 473:565-71. [PMID: 27033597 DOI: 10.1016/j.bbrc.2016.03.122] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 03/26/2016] [Indexed: 01/10/2023]
Abstract
Retinal microglia (RMG) are one of the major immune cells in charge of surveillance of inflammatory responses in the eye. In the absence of an inflammatory stimulus, RMG reside predominately in the ganglion layer and inner or outer plexiform layers. However, under stress RMG become activated and migrate into the inner nuclear layer (INL) or outer nuclear layer (ONL). Activated RMG in cell culture secrete pro-inflammatory cytokines in a manner sensitive to downregulation by aldose reductase inhibitors. In this study, we utilized CX3CR1(GFP) mice carrying AR mutant alleles to evaluate the role of AR on RMG activation and migration in vivo. When tested on an AR(WT) background, IP injection of LPS induced RMG activation and migration into the INL and ONL. However, this phenomenon was largely prevented by AR inhibitors or in AR null mice, or was exacerbated in transgenic mice that over-express AR. LPS-induced increases in ocular levels of TNF-α and CX3CL-1 in WT mice were substantially lower in AR null mice or were reduced by AR inhibitor treatment. These studies demonstrate that AR expression in RMG may contribute to the proinflammatory phenotypes common to various eye diseases such as uveitis and diabetic retinopathy.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Biehuoy Shieh
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - J Mark Petrash
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
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Luo X, Wu J, Jing S, Yan LJ. Hyperglycemic Stress and Carbon Stress in Diabetic Glucotoxicity. Aging Dis 2016; 7:90-110. [PMID: 26816666 DOI: 10.14336/ad.2015.0702] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 07/02/2015] [Indexed: 12/16/2022] Open
Abstract
Diabetes and its complications are caused by chronic glucotoxicity driven by persistent hyperglycemia. In this article, we review the mechanisms of diabetic glucotoxicity by focusing mainly on hyperglycemic stress and carbon stress. Mechanisms of hyperglycemic stress include reductive stress or pseudohypoxic stress caused by redox imbalance between NADH and NAD(+) driven by activation of both the polyol pathway and poly ADP ribose polymerase; the hexosamine pathway; the advanced glycation end products pathway; the protein kinase C activation pathway; and the enediol formation pathway. Mechanisms of carbon stress include excess production of acetyl-CoA that can over-acetylate a proteome and excess production of fumarate that can over-succinate a proteome; both of which can increase glucotoxicity in diabetes. For hyperglycemia stress, we also discuss the possible role of mitochondrial complex I in diabetes as this complex, in charge of NAD(+) regeneration, can make more reactive oxygen species (ROS) in the presence of excess NADH. For carbon stress, we also discuss the role of sirtuins in diabetes as they are deacetylases that can reverse protein acetylation thereby attenuating diabetic glucotoxicity and improving glucose metabolism. It is our belief that targeting some of the stress pathways discussed in this article may provide new therapeutic strategies for treatment of diabetes and its complications.
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Affiliation(s)
- Xiaoting Luo
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; 2 Department of Biochemistry and Molecular Biology, Gannan Medical University, Ganzhou, Jiangxi province, China, 341000
| | - Jinzi Wu
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Siqun Jing
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; 3 College of Life Sciences and Technology, Xinjiang University, Urumqi, Xinjiang, China, 830046
| | - Liang-Jun Yan
- 1 Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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Wu J, Jin Z, Zheng H, Yan LJ. Sources and implications of NADH/NAD(+) redox imbalance in diabetes and its complications. Diabetes Metab Syndr Obes 2016; 9:145-53. [PMID: 27274295 PMCID: PMC4869616 DOI: 10.2147/dmso.s106087] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
NAD(+) is a fundamental molecule in metabolism and redox signaling. In diabetes and its complications, the balance between NADH and NAD(+) can be severely perturbed. On one hand, NADH is overproduced due to influx of hyperglycemia to the glycolytic and Krebs cycle pathways and activation of the polyol pathway. On the other hand, NAD(+) can be diminished or depleted by overactivation of poly ADP ribose polymerase that uses NAD(+) as its substrate. Moreover, sirtuins, another class of enzymes that also use NAD(+) as their substrate for catalyzing protein deacetylation reactions, can also affect cellular content of NAD(+). Impairment of NAD(+) regeneration enzymes such as lactate dehydrogenase in erythrocytes and complex I in mitochondria can also contribute to NADH accumulation and NAD(+) deficiency. The consequence of NADH/NAD(+) redox imbalance is initially reductive stress that eventually leads to oxidative stress and oxidative damage to macromolecules, including DNA, lipids, and proteins. Accordingly, redox imbalance-triggered oxidative damage has been thought to be a major factor contributing to the development of diabetes and its complications. Future studies on restoring NADH/NAD(+) redox balance could provide further insights into design of novel antidiabetic strategies.
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Affiliation(s)
- Jinzi Wu
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Zhen Jin
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Hong Zheng
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
- Department of Basic Theory of Traditional Chinese Medicine, College of Basic Medicine, Shandong University of Traditional Chinese Medicine, Jinan, People’s Republic of China
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
- Correspondence: Liang-Jun Yan, Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA, Tel +1 817 735 2386, Fax +1 817 735 2603, Email
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Le TKC, Hosaka T, Nguyen TT, Kassu A, Dang TO, Tran HB, Pham TP, Tran QB, Le THH, Pham XD. Bifidobacterium species lower serum glucose, increase expressions of insulin signaling proteins, and improve adipokine profile in diabetic mice. Biomed Res 2015; 36:63-70. [PMID: 25749152 DOI: 10.2220/biomedres.36.63] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This study, using C57BL/6J mice with streptozotocin (STZ)-induced diabetes, aimed to determine whether Bifidobacterium species (spp.) both induces the expressions of proteins in the insulin signaling pathway and enhances the expressions of certain adipocytokines. The protein expressions of IκB kinase alpha (IKKα), IκB kinase beta (IKKβ), nuclear factor-kappaB inhibitor alpha (IκBα), and the mitogen-activated protein kinase (MAPK) pathway were also investigated. Oral administration of Bifidobacterium spp. reduced blood glucose levels significantly and increased the protein expressions of insulin receptor beta, insulin receptor substrate 1, protein kinase B (Akt/PKB), IKKα, and IκBα. Extracellular-signal-regulated kinase 2 (ERK2) showed increased expression. Bifidobacterium spp. also induced the adiponectin expression and decreased both macrophage chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) expression. In addition, IKKβ, c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase expressions showed no significant changes in both groups. In conclusion, Bifidobacterium spp. may be the promising bacteria for treating diabetes.
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Affiliation(s)
- Thi Kim Chung Le
- Department of Food Microbiology, National Institute for Food Control
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Saliba A, Du Y, Liu H, Patel S, Roberts R, Berkowitz BA, Kern TS. Photobiomodulation Mitigates Diabetes-Induced Retinopathy by Direct and Indirect Mechanisms: Evidence from Intervention Studies in Pigmented Mice. PLoS One 2015; 10:e0139003. [PMID: 26426815 PMCID: PMC4591336 DOI: 10.1371/journal.pone.0139003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2022] Open
Abstract
Objective Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM) is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied. Methods Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm) daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo. Results PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers. Conclusions PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic retinopathy.
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Affiliation(s)
- Alexandra Saliba
- Case Western Reserve University, Cleveland, Ohio, United States of America
- Catholic University of Brasilia, Brasilia, Brazil
| | - Yunpeng Du
- Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Haitao Liu
- Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Shyam Patel
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
| | - Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
- Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States of America
| | - Timothy S. Kern
- Case Western Reserve University, Cleveland, Ohio, United States of America
- Cleveland Veteran’s Affairs Medical Center, Research Service 151, Cleveland, Ohio, United States of America
- * E-mail:
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Veenstra A, Liu H, Lee CA, Du Y, Tang J, Kern TS. Diabetic Retinopathy: Retina-Specific Methods for Maintenance of Diabetic Rodents and Evaluation of Vascular Histopathology and Molecular Abnormalities. ACTA ACUST UNITED AC 2015; 5:247-270. [PMID: 26331759 DOI: 10.1002/9780470942390.mo140190] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diabetic retinopathy is a major cause of visual impairment, which continues to increase in prevalence as more and more people develop diabetes. Despite the importance of vision, the retina is one of the smallest tissues in the body, and specialized techniques have been developed to study retinopathy. This article summarizes several methods used to (i) induce diabetes in mice, (ii) maintain the diabetic animals throughout the months required for development of typical vascular histopathology, (iii) evaluate vascular histopathology of diabetic retinopathy, and (iv) quantitate abnormalities implicated in the development of the retinopathy.
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Affiliation(s)
- Alexander Veenstra
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio.,These authors contributed equally to this work
| | - Haitao Liu
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,These authors contributed equally to this work
| | - Chieh Allen Lee
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Yunpeng Du
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Jie Tang
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
| | - Timothy S Kern
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
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Potential Bioactive Compounds from Seaweed for Diabetes Management. Mar Drugs 2015; 13:5447-91. [PMID: 26308010 PMCID: PMC4557030 DOI: 10.3390/md13085447] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 06/11/2015] [Accepted: 06/11/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetes mellitus is a group of metabolic disorders of the endocrine system characterised by hyperglycaemia. Type II diabetes mellitus (T2DM) constitutes the majority of diabetes cases around the world and are due to unhealthy diet, sedentary lifestyle, as well as rise of obesity in the population, which warrants the search for new preventive and treatment strategies. Improved comprehension of T2DM pathophysiology provided various new agents and approaches against T2DM including via nutritional and lifestyle interventions. Seaweeds are rich in dietary fibres, unsaturated fatty acids, and polyphenolic compounds. Many of these seaweed compositions have been reported to be beneficial to human health including in managing diabetes. In this review, we discussed the diversity of seaweed composition and bioactive compounds which are potentially useful in preventing or managing T2DM by targeting various pharmacologically relevant routes including inhibition of enzymes such as α-glucosidase, α-amylase, lipase, aldose reductase, protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl-peptidase-4 (DPP-4). Other mechanisms of action identified, such as anti-inflammatory, induction of hepatic antioxidant enzymes’ activities, stimulation of glucose transport and incretin hormones release, as well as β-cell cytoprotection, were also discussed by taking into consideration numerous in vitro, in vivo, and human studies involving seaweed and seaweed-derived agents.
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Coucha M, Elshaer SL, Eldahshan WS, Mysona BA, El-Remessy AB. Molecular mechanisms of diabetic retinopathy: potential therapeutic targets. Middle East Afr J Ophthalmol 2015; 22:135-44. [PMID: 25949069 PMCID: PMC4411608 DOI: 10.4103/0974-9233.154386] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Diabetic retinopathy (DR) is the leading cause of blindness in working-age adults in United States. Research indicates an association between oxidative stress and the development of diabetes complications. However, clinical trials with general antioxidants have failed to prove effective in diabetic patients. Mounting evidence from experimental studies that continue to elucidate the damaging effects of oxidative stress and inflammation in both vascular and neural retina suggest its critical role in the pathogenesis of DR. This review will outline the current management of DR as well as present potential experimental therapeutic interventions, focusing on molecules that link oxidative stress to inflammation to provide potential therapeutic targets for treatment or prevention of DR. Understanding the biochemical changes and the molecular events under diabetic conditions could provide new effective therapeutic tools to combat the disease.
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Affiliation(s)
- Maha Coucha
- Department of Clinical Pharmacy, Program in Clinical and Experimental Therapeutics, University of Georgia, Georgia, USA ; Culver Vision Discovery Institute, Georgia Regents University, Georgia, USA ; Research Service, Charlie Norwood VA Medical Center, Augusta 30912, Georgia, USA
| | - Sally L Elshaer
- Department of Clinical Pharmacy, Program in Clinical and Experimental Therapeutics, University of Georgia, Georgia, USA ; Culver Vision Discovery Institute, Georgia Regents University, Georgia, USA ; Research Service, Charlie Norwood VA Medical Center, Augusta 30912, Georgia, USA
| | - Wael S Eldahshan
- Department of Clinical Pharmacy, Program in Clinical and Experimental Therapeutics, University of Georgia, Georgia, USA ; Culver Vision Discovery Institute, Georgia Regents University, Georgia, USA ; Research Service, Charlie Norwood VA Medical Center, Augusta 30912, Georgia, USA
| | - Barbara A Mysona
- Department of Clinical Pharmacy, Program in Clinical and Experimental Therapeutics, University of Georgia, Georgia, USA ; Culver Vision Discovery Institute, Georgia Regents University, Georgia, USA ; Research Service, Charlie Norwood VA Medical Center, Augusta 30912, Georgia, USA
| | - Azza B El-Remessy
- Department of Clinical Pharmacy, Program in Clinical and Experimental Therapeutics, University of Georgia, Georgia, USA ; Culver Vision Discovery Institute, Georgia Regents University, Georgia, USA ; Research Service, Charlie Norwood VA Medical Center, Augusta 30912, Georgia, USA
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Vecino E, Rodriguez FD, Ruzafa N, Pereiro X, Sharma SC. Glia-neuron interactions in the mammalian retina. Prog Retin Eye Res 2015; 51:1-40. [PMID: 26113209 DOI: 10.1016/j.preteyeres.2015.06.003] [Citation(s) in RCA: 489] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/18/2015] [Accepted: 06/02/2015] [Indexed: 02/07/2023]
Abstract
The mammalian retina provides an excellent opportunity to study glia-neuron interactions and the interactions of glia with blood vessels. Three main types of glial cells are found in the mammalian retina that serve to maintain retinal homeostasis: astrocytes, Müller cells and resident microglia. Müller cells, astrocytes and microglia not only provide structural support but they are also involved in metabolism, the phagocytosis of neuronal debris, the release of certain transmitters and trophic factors and K(+) uptake. Astrocytes are mostly located in the nerve fibre layer and they accompany the blood vessels in the inner nuclear layer. Indeed, like Müller cells, astrocytic processes cover the blood vessels forming the retinal blood barrier and they fulfil a significant role in ion homeostasis. Among other activities, microglia can be stimulated to fulfil a macrophage function, as well as to interact with other glial cells and neurons by secreting growth factors. This review summarizes the main functional relationships between retinal glial cells and neurons, presenting a general picture of the retina recently modified based on experimental observations. The preferential involvement of the distinct glia cells in terms of the activity in the retina is discussed, for example, while Müller cells may serve as progenitors of retinal neurons, astrocytes and microglia are responsible for synaptic pruning. Since different types of glia participate together in certain activities in the retina, it is imperative to explore the order of redundancy and to explore the heterogeneity among these cells. Recent studies revealed the association of glia cell heterogeneity with specific functions. Finally, the neuroprotective effects of glia on photoreceptors and ganglion cells under normal and adverse conditions will also be explored.
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Affiliation(s)
- Elena Vecino
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - F David Rodriguez
- Department of Biochemistry and Molecular Biology, E-37007, University of Salamanca, Salamanca, Spain
| | - Noelia Ruzafa
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Xandra Pereiro
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Sansar C Sharma
- Department of Ophthalmology, Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA; IKERBASQUE, Basque Foundation for Science at Dept. Cell Biology and Histology, UPV/EHU, Spain
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Veluthakal R, Kumar B, Mohammad G, Kowluru A, Kowluru RA. Tiam1-Rac1 Axis Promotes Activation of p38 MAP Kinase in the Development of Diabetic Retinopathy: Evidence for a Requisite Role for Protein Palmitoylation. Cell Physiol Biochem 2015; 36:208-20. [PMID: 25967961 PMCID: PMC4435616 DOI: 10.1159/000374065] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2015] [Indexed: 01/14/2023] Open
Abstract
Background/Aims Evidence in multiple tissues, including retina, suggests generation of reactive oxygen species (ROS) and the ensuing oxidative stress as triggers for mitochondrial defects and cell apoptosis. We recently reported novel roles for Tiam1-Rac1-Nox2 axis in retinal mitochondrial dysfunction and cell death leading to the development of diabetic retinopathy. Herein, we tested the hypothesis that activation of p38 MAP kinase, a stress kinase, represents the downstream signaling event to Rac1-Nox2 activation in diabetes-induced metabolic stress leading to capillary cell apoptosis. Methods Activation of p38 MAP kinase was quantified by Western blotting in retinal endothelial cells incubated with high glucose (20 mM) for up to 96 hours, a duration where mitochondrial dysfunction and capillary cell apoptosis can be observed. NSC23766 and 2-bromopalmitate (2-BP) were used to assess the roles of Tiam1-Rac1 and palmitoylation pathways, respectively. Results Activation of p38 MAP kinase was observed as early as 3 hours after high glucose exposure, and continued until 96 hours. Consistent with this, p38 MAP kinase activation was significantly higher in the retina from diabetic mice compared to age-matched normal mice. NSC23766 markedly attenuated hyperglycemia-induced activation of p38 MAP kinase. Lastly, 2-BP inhibited glucose-induced Rac1, Nox2 and p38 MAP kinase activation in endothelial cells. Conclusions Tiam1-Rac1-mediated activation of Nox2 and p38 MAP kinase constitutes early signaling events leading to mitochondrial dysfunction and the development of diabetic retinopathy. Our findings also provide the first evidence to implicate novel roles for protein palmitoylation in this signaling cascade.
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Du Y, Cramer M, Lee CA, Tang J, Muthusamy A, Antonetti DA, Jin H, Palczewski K, Kern TS. Adrenergic and serotonin receptors affect retinal superoxide generation in diabetic mice: relationship to capillary degeneration and permeability. FASEB J 2015; 29:2194-204. [PMID: 25667222 DOI: 10.1096/fj.14-269431] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 12/22/2022]
Abstract
Reactive oxygen species play an important role in the pathogenesis of diabetic retinopathy. We studied the role of adrenergic and serotonin receptors in the generation of superoxide by retina and 661W retinal cells in high glucose and of the α1-adrenergic receptor (AR) on vascular lesions of the retinopathy in experimentally diabetic C57Bl/6J mice (and controls) after 2 and 8 months. Compared with 5 mM glucose, incubating cells or retinal explants in 30 mM glucose induced superoxide generation. This response was reduced or ablated by pharmacologic inhibition of the α1-AR (a Gq-coupled receptor) or Gs-coupled serotonin (5-HT2, 5-HT4, 5-HT6, and 5-HT7) receptors or by activation of the Gi-coupled α2-AR. In elevated glucose, the α1-AR produced superoxide via phospholipase C, inositol triphosphate-induced Ca(2+) release, and NADPH oxidase, and pharmacologic inhibition of these reactions prevented the superoxide increase. Generation of retinal superoxide, expression of proinflammatory proteins, and degeneration of retinal capillaries in diabetes all were significantly inhibited with daily doxazosin or apocynin (inhibitors of α1-AR and NADPH oxidase, respectively), but increased vascular permeability was not significantly affected. Adrenergic receptors, and perhaps other GPCRs, represent novel targets for inhibiting the development of important features of diabetic retinopathy.
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Affiliation(s)
- Yunpeng Du
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Megan Cramer
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Chieh Allen Lee
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Jie Tang
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Arivalagan Muthusamy
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - David A Antonetti
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Hui Jin
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Krzysztof Palczewski
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Timothy S Kern
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
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Snow A, Shieh B, Chang KC, Pal A, Lenhart P, Ammar D, Ruzycki P, Palla S, Reddy GB, Petrash JM. Aldose reductase expression as a risk factor for cataract. Chem Biol Interact 2014; 234:247-53. [PMID: 25541468 DOI: 10.1016/j.cbi.2014.12.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 12/09/2014] [Accepted: 12/14/2014] [Indexed: 12/11/2022]
Abstract
Aldose reductase (AR) is thought to play a role in the pathogenesis of diabetic eye diseases, including cataract and retinopathy. However, not all diabetics develop ocular complications. Paradoxically, some diabetics with poor metabolic control appear to be protected against retinopathy, while others with a history of excellent metabolic control develop severe complications. These observations indicate that one or more risk factors may influence the likelihood that an individual with diabetes will develop cataracts and/or retinopathy. We hypothesize that an elevated level of AR gene expression could confer higher risk for development of diabetic eye disease. To investigate this hypothesis, we examined the onset and severity of diabetes-induced cataract in transgenic mice, designated AR-TG, that were either heterozygous or homozygous for the human AR (AKR1B1) transgene construct. AR-TG mice homozygous for the transgene demonstrated a conditional cataract phenotype, whereby they developed lens vacuoles and cataract-associated structural changes only after induction of experimental diabetes; no such changes were observed in AR-TG heterozygotes or nontransgenic mice with or without experimental diabetes induction. We observed that nondiabetic AR-TG mice did not show lens structural changes even though they had lenticular sorbitol levels almost as high as the diabetic AR-TG lenses that showed early signs of cataract. Over-expression of AR led to increases in the ratio of activated to total levels of extracellular signal-regulated kinase (ERK1/2) and c-Jun N-terminal (JNK1/2), which are known to be involved in cell growth and apoptosis, respectively. After diabetes induction, AR-TG but not WT controls had decreased levels of phosphorylated as well as total ERK1/2 and JNK1/2 compared to their nondiabetic counterparts. These results indicate that high AR expression in the context of hyperglycemia and insulin deficiency may constitute a risk factor that could predispose the lens to disturbances in signaling through the ERK and JNK pathways and thereby alter the balance of cell growth and apoptosis that is critical to lens transparency and homeostasis.
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Affiliation(s)
- Anson Snow
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - Biehuoy Shieh
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - Kun-Che Chang
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - Arttatrana Pal
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - Patricia Lenhart
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - David Ammar
- Department of Ophthalmology, University of Colorado Denver, CO, USA
| | - Philip Ruzycki
- Department of Ophthalmology, Rocky Mountain Lions Eye Institute, University of Colorado Denver, Aurora, CO, USA
| | - Suryanarayana Palla
- Biochemistry Division, National Institute of Nutrition, Hyderabad 500 604, India
| | - G Bhanuprakesh Reddy
- Biochemistry Division, National Institute of Nutrition, Hyderabad 500 604, India
| | - J Mark Petrash
- Department of Ophthalmology, University of Colorado Denver, CO, USA.
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Chang KC, Snow A, LaBarbera DV, Petrash JM. Aldose reductase inhibition alleviates hyperglycemic effects on human retinal pigment epithelial cells. Chem Biol Interact 2014; 234:254-60. [PMID: 25451566 DOI: 10.1016/j.cbi.2014.10.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/02/2014] [Accepted: 10/08/2014] [Indexed: 12/11/2022]
Abstract
Chronic hyperglycemia is an important risk factor involved in the onset and progression of diabetic retinopathy (DR). Among other effectors, aldose reductase (AR) has been linked to the pathogenesis of this degenerative disease. The purpose of this study was to investigate whether the novel AR inhibitor, beta-glucogallin (BGG), can offer protection against various hyperglycemia-induced abnormalities in human adult retinal pigment epithelial (ARPE-19) cells. AR is an enzyme that contributes to cellular stress by production of reactive oxygen species (ROS) under high glucose conditions. A marked decrease in cell viability (from 100% to 78%) following long-term exposure (4 days) of RPE cells to high glucose (HG) was largely prevented by siRNA-mediated knockdown of AR gene expression (from 79% to 97%) or inhibition using sorbinil (from 66% to 86%). In HG, BGG decreased sorbitol accumulation (44%), ROS production (27%) as well as ER stress (22%). Additionally, we demonstrated that BGG prevented loss of mitochondrial membrane potential (MMP) under HG exposure. We also showed that AR inhibitor pretreatment reduced retinal microglia-induced apoptosis in APRE-19 cells. These results suggest that BGG may be useful as a therapeutic agent against retinal degeneration in the diabetic eye by preventing RPE cell death.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Anson Snow
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Daniel V LaBarbera
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - J Mark Petrash
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
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Lee CA, Li G, Patel MD, Petrash JM, Benetz BA, Veenstra A, Amengual J, von Lintig J, Burant CJ, Tang J, Kern TS. Diabetes-induced impairment in visual function in mice: contributions of p38 MAPK, rage, leukocytes, and aldose reductase. Invest Ophthalmol Vis Sci 2014; 55:2904-10. [PMID: 23920367 DOI: 10.1167/iovs.13-11659] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Visual function is impaired in diabetes, but molecular causes of this dysfunction are not clear. We assessed effects of diabetes on visual psychophysics in mice, and tested the effect of therapeutic approaches reported previously to inhibit vascular lesions of the retinopathy. METHODS We used the optokinetic test to assess contrast sensitivity and spatial frequency threshold in diabetic C57Bl/6J mice and age-matched nondiabetic controls between 2 and 10 months of diabetes. Contributions of p38 MAP kinase (MAPK), receptor for advanced glycation end products (RAGE), leukocytes, and aldose reductase (AR) to the defect in contrast sensitivity were investigated. Cataract, a potential contributor to reductions in vision, was scored. RESULTS Diabetes of 2 months' duration impaired contrast sensitivity and spatial frequency threshold in mice. The defect in contrast sensitivity persisted for at least 10 months, and cataract did not account for this impairment. Diabetic mice deficient in AR were protected significantly from development of the diabetes-induced defects in contrast sensitivity and spatial frequency threshold. In contrast, pharmacologic inhibition of p38 MAPK or RAGE, or deletion of inducible nitrous oxide synthase (iNOS) from bone marrow-derived cells did not protect the visual function in diabetes. CONCLUSIONS Diabetes reduces spatial frequency threshold and contrast sensitivity in mice, and the mechanism leading to development of these defects involves AR. The mechanism by which AR contributes to the diabetes-induced defect in visual function can be probed by identifying which molecular abnormalities are corrected by AR deletion, but not other therapies that do not correct the defect in visual function.
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Affiliation(s)
- Chieh Allen Lee
- Case Western Reserve University, Cleveland, Ohio, United States
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Chang KC, Ponder J, Labarbera DV, Petrash JM. Aldose reductase inhibition prevents endotoxin-induced inflammatory responses in retinal microglia. Invest Ophthalmol Vis Sci 2014; 55:2853-61. [PMID: 24677107 DOI: 10.1167/iovs.13-13487] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Retinal microglia become activated in diabetes and produce pro-inflammatory molecules associated with changes in retinal vasculature and increased apoptosis of retinal neurons and glial cells. We sought to determine if the action of aldose reductase (AR), an enzyme linked to the pathogenesis of diabetic retinopathy, contributes to activation of microglial cells. METHODS Involvement of AR in the activation process was studied using primary cultures of retinal microglia (RMG) isolated from wild-type and AR-null mice, or in mouse macrophage cultures treated with either AR inhibitors or small interfering RNA (siRNA) directed to AR. Inflammatory cytokines were measured by ELISA. Cell migration was measured using a transwell assay. Gelatin zymography was used to detect active matrix metalloproteinase (MMP)-9, while RMG-induced apoptosis of adult retinal pigment epithelium (ARPE-19) cells was studied in a cell coculture system. RESULTS Aldose reductase inhibition or genetic deficiency substantially reduced lipopolysacharide (LPS)-induced cytokine secretion from macrophages and RMG. Aldose reductase inhibition or deficiency also reduced the activation of MMP-9 and attenuated LPS-induced cell migration. Additionally, blockade of AR by sorbinil or through genetic means caused a reduction in the ability of activated RMG to induce apoptosis of ARPE-19 cells. CONCLUSIONS These results demonstrate that the action of AR contributes to the activation of RMG. Inhibition of AR may be a therapeutic strategy to reduce inflammation associated with activation of RMG in disease.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
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Chatzopoulou M, Pegklidou K, Papastavrou N, Demopoulos VJ. Development of aldose reductase inhibitors for the treatment of inflammatory disorders. Expert Opin Drug Discov 2013; 8:1365-80. [PMID: 24090200 DOI: 10.1517/17460441.2013.843524] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Accumulating evidence attributes a significant role to aldose reductase (ALR2) in the pathogenesis of several inflammatory pathologies. Aldose reductase inhibitors (ARIs) were found to attenuate reactive oxygen species (ROS) production both in vitro and in vivo. Thus, they disrupt signaling cascades that lead to the production of cytokines/chemokines, which induce and exacerbate inflammation. As a result, ARIs might hold a significant therapeutic potential as alternate anti-inflammatory drugs. AREAS COVERED The authors present a comprehensive review of the current data that support the central role of ALR2 in several inflammatory pathologies (i.e., diabetes, cancer, sepsis, asthma and ocular inflammation). Further, the authors describe the potential underlying molecular mechanisms and provide a commentary on the status of ARIs in this field. EXPERT OPINION It is important that future efforts focus on delineating all the steps of the molecular mechanism that implicates ALR2 in inflammatory pathologies. At the same time, utilizing the previous efforts in the field of ARIs, several candidates that have been proven safe in the clinic may be evaluated for their clinical significance as anti-inflammatory medication. Finally, structurally novel ARIs, designed to target specifically the proinflammatory subpocket of ALR2, should be pursued.
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Affiliation(s)
- Maria Chatzopoulou
- Aristotle University of Thessaloniki, School of Pharmacy, Department of Pharmaceutical Chemistry , 54124 Thessaloniki , Greece ;
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Abstract
Chronic hyperglycemia (HG)-associated reactive oxygen/nitrogen species (ROS/RNS) stress and low grade inflammation are considered to play critical roles in the development of diabetic retinopathy (DR). Excess glucose metabolic flux through the aldose reductase/polyol pathway, advanced glycation end product (AGE) formation, elevated hexosamine biosynthesis pathway (HBP), diacyl glycerol/PKC activation, and mitochondrial ROS generation are all implicated in DR. In addition, endoplasmic reticulum stress/unfolded protein response (er-UPR) and deregulation of mitochondrial quality control by autophagy/mitophagy are observed causing cellular bioenergetic deficiency and injury. Recently, a pro-oxidant and pro-apoptotic thioredoxin interacting protein (TXNIP) was shown to be highly upregulated in DR and by HG in retinal cells in culture. TXNIP binds to thioredoxin (Trx) inhibiting its oxidant scavenging and thiolreducing capacity. Hence, prolonged overexpression of TXNIP causes ROS/RNS stress, mitochondrial dysfunction, inflammation and premature cell death in DR. Initially, DR was considered as microvascular complications of endothelial dysfunction and pericyte loss characterized by capillary basement membrane thickening, pericyte ghost, blood retinal barrier leakage, acellular capillary and neovascularization. However, it is currently acknowledged that neuro-glia are also affected by HG in diabetes and that neuronal injury, glial activation, innate immunity/sterile inflammation, and ganglion apoptosis occur early in DR. In addition, retinal pigment epithelium (RPE) becomes dysfunctional in DR. Since TXNIP is induced by HG in most cells, its effects are not restricted to a particular cell type in DR. However, depending on the metabolic activity and anti-oxidant capacity, some cells may be affected earlier by TXNIP than others. Identification of TXNIP sensitive cells and elucidating the underlying mechanism(s) will be critical for preventing pre-mature cell death and progression of DR.
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Affiliation(s)
- Lalit P Singh
- Departments of Anatomy and Cell Biology and Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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