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Bryl A, Mrugacz M, Falkowski M, Zorena K. A Mediterranean Diet May Be Protective in the Development of Diabetic Retinopathy. Int J Mol Sci 2023; 24:11145. [PMID: 37446322 DOI: 10.3390/ijms241311145] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
The Mediterranean diet is recognized as one of the healthiest available dietary patterns. This perception results from its beneficial effects on the cardiovascular system and, also, on hypertension, diabetes, and cancer compared with other diets. Its impact on the course of diabetes is assessed in the available scientific literature; however, little information is available about its impact on diabetic retinopathy. The MD is characterized mainly by the consumption of fish, seafood, foods of plant origin, and fresh fruit and vegetables. It is also recommended to consume legumes, which are a source of folic acid, magnesium, iron, and dietary fiber. High consumption of nuts and unrefined grains is also recommended in the MD. Marine fish provide polyunsaturated acids from the omega-3 group. Olive oil plays a very important role, especially olive oil obtained from mechanical pressing. Additionally, olive oil contains vitamins E, K, and polyphenols. Polyphenols, which are present in a diverse range of vegetables, fruits, and seeds, have the ability to decrease oxidative stress, inflammation, and insulin resistance. Resveratrol is naturally found in grape skins and seeds, as well as in peanuts and berries, and is a constituent of red wine. Resveratrol can inhibit increased vascular leakage and loss of pericytes and regulate the level of VEGF protein in the retina, thus inhibiting the development of DR. Consumption of fruits, vegetables, fish, and olive oil may be correlated with a lower risk of diabetic retinopathy. This paper presents the definition of the Mediterranean diet and its influence on the course of diabetes and diabetic retinopathy.
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Affiliation(s)
- Anna Bryl
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Bialystok, Poland
| | - Małgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Bialystok, Poland
| | - Mariusz Falkowski
- PhD Studies, Medical University of Bialystok, 15-089 Bialystok, Poland
| | - Katarzyna Zorena
- Department of Immunobiology and Environmental Microbiology, Medical University of Gdansk, 80-211 Gdansk, Poland
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Chen Y, Schlotterer A, Kurowski L, Li L, Dannehl M, Hammes HP, Lin J. miRNA-124 Prevents Rat Diabetic Retinopathy by Inhibiting the Microglial Inflammatory Response. Int J Mol Sci 2023; 24:ijms24032291. [PMID: 36768614 PMCID: PMC9917205 DOI: 10.3390/ijms24032291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
Diabetic retinopathy (DR) is characterized by vasoregression and glial activation. miRNA-124 (miR-124) reduces retinal microglial activation and alleviates vasoregression in a neurodegenerative rat model. Our aim was to determine whether miR-124 affects vascular and neural damage in the early diabetic retina. Diabetes was induced in 8-week-old Wistar rats by streptozotocin (STZ) injection. At 16 and 20 weeks, the diabetic rats were intravitreally injected with miR-124 mimic, and retinae were analyzed at 24 weeks. Microvascular damage was identified by evaluating pericyte loss and acellular capillary (AC) formation. Müller glial activation was assessed by glial fibrillary acidic protein (GFAP) immunofluorescence staining. Microglial activation was determined by immunofluorescent staining of ionized calcium-binding adaptor molecule 1 (Iba1) in whole mount retinae. The neuroretinal function was assessed by electroretinography. The expression of inflammation-associated genes was evaluated by qRT-PCR. A wound healing assay was performed to quantitate the mobility of microglial cells. The results showed that miR-124 treatment alleviated diabetic vasoregression by reducing AC formation and pericyte loss. miR-124 blunted Müller glial- and microglial activation in diabetic retinae and ameliorated neuroretinal function. The retinal expression of inflammatory factors including Tnf-α, Il-1β, Cd74, Ccl2, Ccl3, Vcam1, Tgf-β1, Arg1, and Il-10 was reduced by miR-124 administration. The elevated mobility of microglia upon high glucose exposure was normalized by miR-124. The expression of the transcription factor PU.1 and lipid raft protein Flot1 was downregulated by miR-124. In rat DR, miR-124 prevents vasoregression and glial activation, improves neuroretinal function, and modulates microglial activation and inflammatory responses.
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Affiliation(s)
- Ying Chen
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Andrea Schlotterer
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Luke Kurowski
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Lin Li
- Department of Vascular Surgery, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Marcus Dannehl
- Department of Pediatrics, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Hans-Peter Hammes
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
| | - Jihong Lin
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany
- Correspondence: ; Tel.: +49-621-383-3774
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Wu Y, Zou H. Research Progress on Mitochondrial Dysfunction in Diabetic Retinopathy. Antioxidants (Basel) 2022; 11:2250. [PMID: 36421435 PMCID: PMC9686704 DOI: 10.3390/antiox11112250] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/07/2022] [Accepted: 11/12/2022] [Indexed: 09/07/2023] Open
Abstract
Diabetic Retinopathy (DR) is one of the most important microvascular complications of diabetes mellitus, which can lead to blindness in severe cases. Mitochondria are energy-producing organelles in eukaryotic cells, which participate in metabolism and signal transduction, and regulate cell growth, differentiation, aging, and death. Metabolic changes of retinal cells and epigenetic changes of mitochondria-related genes under high glucose can lead to mitochondrial dysfunction and induce mitochondrial pathway apoptosis. In addition, mitophagy and mitochondrial dynamics also change adaptively. These mechanisms may be related to the occurrence and progression of DR, and also provide valuable clues for the prevention and treatment of DR. This article reviews the mechanism of DR induced by mitochondrial dysfunction, and the prospects for related treatment.
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Affiliation(s)
- Yiwei Wu
- Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
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Chen Y, Lin J, Schlotterer A, Kurowski L, Hoffmann S, Hammad S, Dooley S, Buchholz M, Hu J, Fleming I, Hammes HP. MicroRNA-124 Alleviates Retinal Vasoregression via Regulating Microglial Polarization. Int J Mol Sci 2021; 22:ijms222011068. [PMID: 34681723 PMCID: PMC8538759 DOI: 10.3390/ijms222011068] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 12/15/2022] Open
Abstract
Microglial activation is implicated in retinal vasoregression of the neurodegenerative ciliopathy-associated disease rat model (i.e., the polycystic kidney disease (PKD) model). microRNA can regulate microglial activation and vascular function, but the effect of microRNA-124 (miR-124) on retinal vasoregression remains unclear. Transgenic PKD and wild-type Sprague Dawley (SD) rats received miR-124 at 8 and 10 weeks of age intravitreally. Retinal glia activation was assessed by immunofluorescent staining and in situ hybridization. Vasoregression and neuroretinal function were evaluated by quantitative retinal morphometry and electroretinography (ERG), respectively. Microglial polarization was determined by immunocytochemistry and qRT-PCR. Microglial motility was examined via transwell migration assays, wound healing assays, and single-cell tracking. Our data showed that miR-124 inhibited glial activation and improved vasoregession, as evidenced by the reduced pericyte loss and decreased acellular capillary formation. In addition, miR-124 improved neuroretinal function. miR-124 shifted microglial polarization in the PKD retina from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype by suppressing TNF-α, IL-1β, CCL2, CCL3, MHC-II, and IFN-γ and upregulating Arg1 and IL-10. miR-124 also decreased microglial motility in the migration assays. The transcriptional factor of C/EBP-α-PU.1 signaling, suppressed by miR-124 both in vivo (PKD retina) and in vitro (microglial cells), could serve as a key regulator in microglial activation and polarization. Our data illustrate that miR-124 regulates microglial activation and polarization. miR-124 inhibits pericyte loss and thereby alleviates vasoregression and ameliorates neurovascular function.
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Affiliation(s)
- Ying Chen
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (Y.C.); (J.L.); (A.S.); (L.K.)
| | - Jihong Lin
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (Y.C.); (J.L.); (A.S.); (L.K.)
| | - Andrea Schlotterer
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (Y.C.); (J.L.); (A.S.); (L.K.)
| | - Luke Kurowski
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (Y.C.); (J.L.); (A.S.); (L.K.)
| | - Sigrid Hoffmann
- Center of Medical Research, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany;
| | - Seddik Hammad
- Molecular Hepatology Section, Department of Medicine II, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (S.H.); (S.D.)
| | - Steven Dooley
- Molecular Hepatology Section, Department of Medicine II, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (S.H.); (S.D.)
| | - Malte Buchholz
- Department of Gastroenterology and Endocrinology, University Hospital, Philipps-University Marburg, Hans-Meerwein-Str. 3, D-35043 Marburg, Germany;
| | - Jiong Hu
- Institute for Vascular Signalling, Center for Molecular Medicine, Goethe University, D-60590 Frankfurt, Germany; (J.H.); (I.F.)
| | - Ingrid Fleming
- Institute for Vascular Signalling, Center for Molecular Medicine, Goethe University, D-60590 Frankfurt, Germany; (J.H.); (I.F.)
| | - Hans-Peter Hammes
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany; (Y.C.); (J.L.); (A.S.); (L.K.)
- Correspondence: ; Tel.: +49-621-383-2663
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Losso JN. Food Processing, Dysbiosis, Gastrointestinal Inflammatory Diseases, and Antiangiogenic Functional Foods or Beverages. Annu Rev Food Sci Technol 2021; 12:235-258. [PMID: 33467906 DOI: 10.1146/annurev-food-062520-090235] [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: 01/16/2023]
Abstract
Foods and beverages provide nutrients and alter the gut microbiota, resulting in eubiosis or dysbiosis. Chronic consumption of a diet that is high in saturated or trans fats, meat proteins, reducing sugars, and salt and low in fiber induces dysbiosis. Dysbiosis, loss of redox homeostasis, mast cells, hypoxia, angiogenesis, the kynurenine pathway, transglutaminase 2, and/or the Janus kinase pathway are implicated in the pathogenesis and development of inflammatory bowel disease, celiac disease, and gastrointestinal malignancy. This review discusses the effects of oxidative, carbonyl, or glycative stress-inducing dietary ingredients or food processing-derived compounds on gut microbiota and gastrointestinal epithelial and mast cells as well as on the development of associated angiogenic diseases, including key signaling pathways. The preventive or therapeutic potential and the biochemical pathways of antiangiogenic or proangiogenic foods or beverages are also described. The outcomes of the interactions between disease pathways and components of food are critical for the design of foods and beverages for healthy lives.
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Affiliation(s)
- Jack N Losso
- School of Nutrition and Food Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA;
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Ajith TA. Alpha-lipoic acid: A possible pharmacological agent for treating dry eye disease and retinopathy in diabetes. Clin Exp Pharmacol Physiol 2020; 47:1883-1890. [PMID: 32621549 DOI: 10.1111/1440-1681.13373] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/22/2020] [Accepted: 06/26/2020] [Indexed: 12/13/2022]
Abstract
Alpha-lipoic acid (ALA) is a naturally occurring dithiol micronutrient which acts as a cofactor for mitochondrial enzyme activity. Due to its potential antioxidant activity, it is considered as "universal antioxidant". Previous studies reported the pharmacological benefits of ALA such as glycaemic control, improved insulin sensitivity and alleviation of diabetic complications such as neuropathy and cardiovascular diseases. Dry eye disease and retinopathy are prevalent in diabetic patients. Experimental studies demonstrated the beneficial effects of ALA in dry eye and diabetic retinopathy. ALA can prevent the dry eye by down regulating the expression of matrix metalloproteinase-9 in the corneal epithelial cells and activating the antioxidant status of the ocular surface. Furthermore, its direct antioxidant effect can also prevent oxidative stress-induced corneal surface erosion and lachrymal gland damage. ALA prevents diabetic retinopathy through inhibition of O-linked β-N-acetylglucosamine transferase and nuclear factor-kappa B activity and alleviation of oxidative stress. It can activate the nuclear factor erythroid-2-related factor 2 and AMP-activated protein kinase in retinal ganglion cells. Clinical trials conducted in pre-retinopathic diabetic patients showed ALA with genistein and vitamins could protect the retinal cells and decline the inflammatory effect in diabetic patients. However, studies are scant to explore its beneficial effects in dry eye disease and diabetic retinopathy. Therefore, this review article discusses an update on the role of ALA in dry eye disease and diabetic retinopathy, two ocular diseases prevalent in diabetic patients.
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Suzumura A, Terao R, Kaneko H. Protective Effects and Molecular Signaling of n-3 Fatty Acids on Oxidative Stress and Inflammation in Retinal Diseases. Antioxidants (Basel) 2020; 9:E920. [PMID: 32993153 PMCID: PMC7600094 DOI: 10.3390/antiox9100920] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress and inflammation play crucial roles in the development and progression of retinal diseases. Retinal damage by various etiologies can result in retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD). n-3 fatty acids are essential fatty acids and are necessary for homeostasis. They are important retinal membrane components and are involved in energy storage. n-3 fatty acids also have antioxidant and anti-inflammatory properties, and their suppressive effects against ROP, DR, and AMD have been previously evaluated. α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites have been shown to alleviate retinal oxidative stress and inflammation involving various biological signaling pathways. In this review, we summarize the current understanding of the n-3 fatty acids effects on the mechanisms of these retinal diseases and how they exert their therapeutic effects, focusing on ALA, EPA, DHA, and their metabolites. This knowledge may provide new remedial strategies for n-3 fatty acids in the prevention and treatment of retinal diseases associated with oxidative stress and inflammation.
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Affiliation(s)
- Ayana Suzumura
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan;
| | - Ryo Terao
- Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
| | - Hiroki Kaneko
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan;
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Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials. Antioxidants (Basel) 2020; 9:antiox9060561. [PMID: 32604941 PMCID: PMC7346101 DOI: 10.3390/antiox9060561] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022] Open
Abstract
Current therapies for diabetic retinopathy (DR) incorporate blood glucose and blood pressure control, vitrectomy, photocoagulation, and intravitreal injections of anti-vascular endothelial growth factors or corticosteroids. Nonetheless, these techniques have not been demonstrated to completely stop the evolution of this disorder. The pathophysiology of DR is not fully known, but there is more and more evidence indicating that oxidative stress is an important mechanism in the progression of DR. In this sense, antioxidants have been suggested as a possible therapy to reduce the complications of DR. In this review we aim to assemble updated information in relation to in vitro experiments, animal studies and clinical trials dealing with the effect of the antioxidants on DR.
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Lin J, Hu J, Schlotterer A, Wang J, Kolibabka M, Awwad K, Dietrich N, Breitschopf K, Wohlfart P, Kannt A, Lorenz K, Feng Y, Popp R, Hoffmann S, Fleming I, Hammes HP. Protective effect of Soluble Epoxide Hydrolase Inhibition in Retinal Vasculopathy associated with Polycystic Kidney Disease. Am J Cancer Res 2020; 10:7857-7871. [PMID: 32685025 PMCID: PMC7359083 DOI: 10.7150/thno.43154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/20/2020] [Indexed: 12/14/2022] Open
Abstract
Rationale: Vasoregression secondary to glial activation develops in various retinal diseases, including retinal degeneration and diabetic retinopathy. Photoreceptor degeneration and subsequent retinal vasoregression, characterized by pericyte loss and acellular capillary formation in the absence diabetes, are also seen in transgenic rats expressing the polycystic kidney disease (PKD) gene. Activated Müller glia contributes to retinal vasodegeneration, at least in part via the expression of the soluble epoxide hydrolase (sEH). Given that an increase in sEH expression triggered vascular destabilization in diabetes, and that vasoregression is similar in diabetic mice and PKD rats, the aim of the present study was to determine whether sEH inhibition could prevent retinal vasoregression in the PKD rat. Methods: One-month old male homozygous transgenic PKD rats were randomly allocated to receive vehicle or a sEH inhibitor (sEH-I; Sar5399, 30 mg/kg) for four weeks. Wild-type Sprague-Dawley (SD) littermates received vehicle as controls. Retinal sEH expression and activity were measured by Western blotting and LC-MS, and vasoregression was quantified in retinal digestion preparations. Microglial activation and immune response cytokines were assessed by immunofluorescence and quantitative PCR, respectively. 19,20-dihydroxydocosapentaenoic acid (19,20-DHDP) mediated Notch signaling, microglial activation and migration were assessed in vivo and in vitro. Results: This study demonstrates that sEH expression and activity were increased in PKD retinae, which led to elevated production of 19,20-DHDP and the depression of Notch signaling. The latter changes elicited pericyte loss and the recruitment of CD11b+/CD74+ microglia to the perivascular region. Microglial activation increased the expression of immune-response cytokines, and reduced levels of Notch3 and delta-like ligand 4 (Dll4). Treatment with Sar5399 decreased 19,20-DHDP generation and increased Notch3 expression. Sar5399 also prevented vasoregression by reducing pericyte loss and suppressed microglial activation as well as the expression of immune-response cytokines. Mechanistically, the activation of Notch signaling by Dll4 maintained a quiescent microglial cell phenotype, i.e. reduced both the surface presentation of CD74 and microglial migration. In contrast, in retinal explants, 19,20-DHDP and Notch inhibition both promoted CD74 expression and reversed the Dll4-induced decrease in migration. Conclusions: Our data indicate that 19,20-DHDP-induced alterations in Notch-signaling result in microglia activation and pericyte loss and contribute to retinal vasoregression in polycystic kidney disease. Moreover, sEH inhibition can ameliorate vasoregression through reduced activity of inflammatory microglia. sEH inhibition is thus an attractive new therapeutic approach to prevent retinal vasoregression.
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Adjuvant Therapies in Diabetic Retinopathy as an Early Approach to Delay Its Progression: The Importance of Oxidative Stress and Inflammation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3096470. [PMID: 32256949 PMCID: PMC7086452 DOI: 10.1155/2020/3096470] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/16/2020] [Accepted: 02/08/2020] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus (DM) is a progressive disease induced by a sustained state of chronic hyperglycemia that can lead to several complications targeting highly metabolic cells. Diabetic retinopathy (DR) is a multifactorial microvascular complication of DM, with high prevalence, which can ultimately lead to visual impairment. The genesis of DR involves a complex variety of pathways such as oxidative stress, inflammation, apoptosis, neurodegeneration, angiogenesis, lipid peroxidation, and endoplasmic reticulum (ER) stress, each possessing potential therapeutic biomarkers. A specific treatment has yet to be developed for early stages of DR since no management is given other than glycemic control until the proliferative stage develops, offering a poor visual prognosis to the patient. In this narrative review article, we evaluate different dietary regimens, such as the Mediterranean diet, Dietary Pattern to Stop Hypertension (DASH) and their functional foods, and low-calorie diets (LCDs). Nutraceuticals have also been assessed in DR on account of their antioxidant, anti-inflammatory, and antiangiogenic properties, which may have an important impact on the physiopathology of DR. These nutraceuticals have shown to lower reactive oxygen species (ROS), important inflammatory factors, cytokines, and endothelial damage biomarkers either as monotherapies or combined therapies or concomitantly with established diabetes management or nonconventional adjuvant drugs like topical nonsteroidal anti-inflammatory drugs (NSAIDs).
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Augustine J, Troendle EP, Barabas P, McAleese CA, Friedel T, Stitt AW, Curtis TM. The Role of Lipoxidation in the Pathogenesis of Diabetic Retinopathy. Front Endocrinol (Lausanne) 2020; 11:621938. [PMID: 33679605 PMCID: PMC7935543 DOI: 10.3389/fendo.2020.621938] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/21/2020] [Indexed: 12/31/2022] Open
Abstract
Lipids can undergo modification as a result of interaction with reactive oxygen species (ROS). For example, lipid peroxidation results in the production of a wide variety of highly reactive aldehyde species which can drive a range of disease-relevant responses in cells and tissues. Such lipid aldehydes react with nucleophilic groups on macromolecules including phospholipids, nucleic acids, and proteins which, in turn, leads to the formation of reversible or irreversible adducts known as advanced lipoxidation end products (ALEs). In the setting of diabetes, lipid peroxidation and ALE formation has been implicated in the pathogenesis of macro- and microvascular complications. As the most common diabetic complication, retinopathy is one of the leading causes of vision loss and blindness worldwide. Herein, we discuss diabetic retinopathy (DR) as a disease entity and review the current knowledge and experimental data supporting a role for lipid peroxidation and ALE formation in the onset and development of this condition. Potential therapeutic approaches to prevent lipid peroxidation and lipoxidation reactions in the diabetic retina are also considered, including the use of antioxidants, lipid aldehyde scavenging agents and pharmacological and gene therapy approaches for boosting endogenous aldehyde detoxification systems. It is concluded that further research in this area could lead to new strategies to halt the progression of DR before irreversible retinal damage and sight-threatening complications occur.
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Affiliation(s)
- Josy Augustine
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Evan P. Troendle
- Department of Chemistry, King’s College London, London, United Kingdom
| | - Peter Barabas
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Corey A. McAleese
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Thomas Friedel
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Alan W. Stitt
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Tim M. Curtis
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
- *Correspondence: Tim M. Curtis,
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Spencer BG, Estevez JJ, Liu E, Craig JE, Finnie JW. Pericytes, inflammation, and diabetic retinopathy. Inflammopharmacology 2019; 28:697-709. [PMID: 31612299 DOI: 10.1007/s10787-019-00647-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy (DR) is a frequent complication of diabetes mellitus, and a common cause of vision impairment and blindness in these patients, yet many aspects of its pathogenesis remain unresolved. Furthermore, current treatments are not effective in all patients, are only indicated in advanced disease, and are associated with significant adverse effects. This review describes the microvascular features of DR, and how pericyte depletion and low-grade chronic inflammation contribute to the pathogenesis of this common ophthalmic disorder. Existing, novel and investigational pharmacological strategies aimed at modulating the inflammatory component of DR and ameliorating pericyte loss to potentially improve clinical outcomes for patients with diabetic retinopathy, are discussed.
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Affiliation(s)
- Benjamin G Spencer
- TMOU, Flinders Medical Centre, Southern Adelaide Local Health Network, SA Health, Flinders Drive, Bedford Park, SA, 5042, Australia.
| | - Jose J Estevez
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Ebony Liu
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Jamie E Craig
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - John W Finnie
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
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Cecilia OM, José Alberto CG, José NP, Ernesto Germán CM, Ana Karen LC, Luis Miguel RP, Ricardo Raúl RR, Adolfo Daniel RC. Oxidative Stress as the Main Target in Diabetic Retinopathy Pathophysiology. J Diabetes Res 2019; 2019:8562408. [PMID: 31511825 PMCID: PMC6710812 DOI: 10.1155/2019/8562408] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/17/2019] [Accepted: 07/15/2019] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus (DM) causing vision impairment even at young ages. There are numerous mechanisms involved in its development such as inflammation and cellular degeneration leading to endothelial and neural damage. These mechanisms are interlinked thus worsening the diabetic retinopathy outcome. In this review, we propose oxidative stress as the focus point of this complication onset.
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Affiliation(s)
- Olvera-Montaño Cecilia
- Institute of Clinical and Experimental Therapeutics, Department of Physiology, Health Sciences University Center, University of Guadalajara, Mexico
| | - Castellanos-González José Alberto
- Department of Ophthalmology, Specialties Hospital of the National Occidental Medical Center, Mexican Institute of Social Security, Mexico
| | - Navarro-Partida José
- Tecnológico de Monterrey Institute, School of Medicine and Health Sciences, Campus Guadalajara, Mexico
| | - Cardona-Muñoz Ernesto Germán
- Institute of Clinical and Experimental Therapeutics, Department of Physiology, Health Sciences University Center, University of Guadalajara, Mexico
| | - López-Contreras Ana Karen
- Institute of Clinical and Experimental Therapeutics, Department of Physiology, Health Sciences University Center, University of Guadalajara, Mexico
| | | | - Robles-Rivera Ricardo Raúl
- Institute of Clinical and Experimental Therapeutics, Department of Physiology, Health Sciences University Center, University of Guadalajara, Mexico
| | - Rodríguez-Carrizalez Adolfo Daniel
- Institute of Clinical and Experimental Therapeutics, Department of Physiology, Health Sciences University Center, University of Guadalajara, Mexico
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14
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Qiu X, Liu K, Xiao L, Jin S, Dong J, Teng X, Guo Q, Chen Y, Wu Y. Alpha-lipoic acid regulates the autophagy of vascular smooth muscle cells in diabetes by elevating hydrogen sulfide level. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3723-3738. [PMID: 30251691 DOI: 10.1016/j.bbadis.2018.09.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/18/2018] [Accepted: 09/03/2018] [Indexed: 12/13/2022]
Abstract
Dysfunctional vascular smooth muscle (VSM) plays a vital role in the process of atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Alpha-lipoic acid (ALA) can prevent the altered VSM induced by diabetes. However, the precise mechanism underlying the beneficial effect of ALA is not well understood. This study aimed to determine whether ALA ameliorates VSM function by elevating hydrogen sulfide (H2S) level in diabetes and whether this effect is associated with regulation of autophagy of VSM cells (VSMCs). We found decreased serum H2S levels in Chinese patients and rats with type 2 diabetes mellitus (T2DM). ALA treatment could increase H2S level, which reduced the autophagy-related index and activation of the 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, thereby protecting vascular function in rats with T2DM. Propargylglycine (PPG), a cystathionine-γ-lyase inhibitor, could weaken the ALA effect. In cultured VSMCs, high glucose level also reduced H2S level, upregulated the autophagy-related index and activated the AMPK/mTOR pathway, which were reversed by concomitant application of sodium hydrosulfide (NaHS, an H2S donor) or ALA. The protective effect of NaHS or ALA was attenuated by rapamycin (an autophagy activator), 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide (an AMPK activator) or PPG. In contrast, Compound C (an AMPK inhibitor) enhanced the effect of ALA or NaHS. ALA may have a protective effect on VSMCs in T2DM by elevating H2S level and downregulating autophagy via the AMPK/mTOR pathway. This study provides a new target for addressing diabetic macroangiopathy.
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Affiliation(s)
- Xuan Qiu
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Department of Endocrinology, Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, China
| | - Kuanzhi Liu
- Department of Endocrinology, Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, China
| | - Lin Xiao
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Sheng Jin
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Jinghui Dong
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Xu Teng
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Qi Guo
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China
| | - Yuhong Chen
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Intensive Care Unit, Forth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Yuming Wu
- Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, China; Hebei Collaborative Innovation Center for Cardio-Cerebrovascular Disease, Shijiazhuang, Hebei 050000, China; Key Laboratory of Vascular Medicine of Hebei Province, Shijiazhuang, Hebei 050000, China.
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15
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Current Advances in Pharmacotherapy and Technology for Diabetic Retinopathy: A Systematic Review. J Ophthalmol 2018; 2018:1694187. [PMID: 29576875 PMCID: PMC5822768 DOI: 10.1155/2018/1694187] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/12/2017] [Accepted: 11/07/2017] [Indexed: 01/01/2023] Open
Abstract
Diabetic retinopathy (DR) is classically defined by its vascular lesions and damage in the neurons of the retina. The cellular and clinical elements of DR have many features of chronic inflammation. Understanding the individual cell-specific inflammatory changes in the retina may lead to novel therapeutic approaches to prevent vision loss. The systematic use of available pharmacotherapy has been reported as a useful adjunct tool to laser photocoagulation, a gold standard therapy for DR. Direct injections or intravitreal anti-inflammatory and antiangiogenesis agents are widely used pharmacotherapy to effectively treat DR and diabetic macular edema (DME). However, their effectiveness is short term, and the delivery system is often associated with adverse effects, such as cataract and increased intraocular pressure. Further, systemic agents (particularly hypoglycemic, hypolipidemic, and antihypertensive agents) and plants-based drugs have also provided promising treatment in the progression of DR. Recently, advancements in pluripotent stem cells technology enable restoration of retinal functionalities after transplantation of these cells into animals with retinal degeneration. This review paper summarizes the developments in the current and potential pharmacotherapy and therapeutic technology of DR. Literature search was done on online databases, PubMed, Google Scholar, clinitrials.gov, and browsing through individual ophthalmology journals and leading pharmaceutical company websites.
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16
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Oxidative stress and reactive oxygen species: a review of their role in ocular disease. Clin Sci (Lond) 2017; 131:2865-2883. [DOI: 10.1042/cs20171246] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/26/2017] [Accepted: 11/06/2017] [Indexed: 12/13/2022]
Abstract
For many years, oxidative stress arising from the ubiquitous production of reactive oxygen species (ROS) has been implicated in the pathogenesis of various eye diseases. While emerging research has provided some evidence of the important physiological role of ROS in normal cell function, disease may arise where the concentration of ROS exceeds and overwhelms the body’s natural defence against them. Additionally, ROS may induce genomic aberrations which affect cellular homoeostasis and may result in disease. This literature review examines the current evidence for the role of oxidative stress in important ocular diseases with a view to identifying potential therapeutic targets for future study. The need is particularly pressing in developing treatments for conditions which remain notoriously difficult to treat, including glaucoma, diabetic retinopathy and age-related macular degeneration.
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17
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Barrett EJ, Liu Z, Khamaisi M, King GL, Klein R, Klein BEK, Hughes TM, Craft S, Freedman BI, Bowden DW, Vinik AI, Casellini CM. Diabetic Microvascular Disease: An Endocrine Society Scientific Statement. J Clin Endocrinol Metab 2017; 102:4343-4410. [PMID: 29126250 PMCID: PMC5718697 DOI: 10.1210/jc.2017-01922] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 01/18/2023]
Abstract
Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.
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Affiliation(s)
- Eugene J. Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Zhenqi Liu
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Mogher Khamaisi
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - George L. King
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Barbara E. K. Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Timothy M. Hughes
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Suzanne Craft
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Barry I. Freedman
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Donald W. Bowden
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Aaron I. Vinik
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
| | - Carolina M. Casellini
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
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18
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Neurodegeneration in diabetic retinopathy: Potential for novel therapies. Vision Res 2017; 139:82-92. [PMID: 28988945 DOI: 10.1016/j.visres.2017.06.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 11/20/2022]
Abstract
The complex pathology of diabetic retinopathy (DR) affects both vascular and neural tissue. The characteristics of neurodegeneration are well-described in animal models but have more recently been confirmed in the clinical setting, mostly by using non-invasive imaging approaches such as spectral domain optical coherence tomography (SD-OCT). The most frequent observations report loss of tissue in the nerve fiber layer and inner plexiform layer, confirming earlier findings from animal models. In several cases the reduction in inner retinal layers is reported in patients with little evidence of vascular lesions or macular edema, suggesting that degenerative loss of neural tissue in the inner retina can occur after relatively short durations of diabetes. Animal studies also suggest that neurodegeneration leading to retinal thinning is not limited to cell death and tissue loss but also includes changes in neuronal morphology, reduced synaptic protein expression and alterations in neurotransmission, including changes in expression of neurotransmitter receptors as well as neurotransmitter release, reuptake and metabolism. The concept of neurodegeneration as an early component of DR introduces the possibility to explore alternative therapies to prevent the onset of vision loss, including neuroprotective therapies and drugs targeting individual neurotransmitter systems, as well as more general neuroprotective approaches to preserve the integrity of the neural retina. In this review we consider some of the evidence for progressive retinal neurodegeneration in diabetes, and explore potential neuroprotective therapies.
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McCarty MF. Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications. Healthcare (Basel) 2017; 5:E15. [PMID: 28335416 PMCID: PMC5371921 DOI: 10.3390/healthcare5010015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/23/2017] [Accepted: 03/06/2017] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity, 7831 Rush Rose Dr., Apt. 316, Carlsbad, CA 92009, USA.
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20
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Nutrition for diabetic retinopathy: plummeting the inevitable threat of diabetic vision loss. Eur J Nutr 2017; 56:2013-2027. [PMID: 28258307 DOI: 10.1007/s00394-017-1406-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 02/10/2017] [Indexed: 12/14/2022]
Abstract
Diabetic retinopathy (DR) is among the leading causes of preventable blindness. Hyperglycemia, hypertension, hyperlipidemia and anemia majorly predispose its pathogenesis. The current treatment modalities of DR include laser photocoagulation therapy, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents and vitreo-retinal surgery which are costly, highly invasive, unproven for prolonged use and opted in advanced stages of DR. By then retina already encounters a vast damage. Nutrients by their natural physiological, biochemical and molecular action can preserve retinal structure and functions by interfering with the various pathological steps prompting DR incidence, thereby altering the risk of developing this ocular morbidity. Nutrients can also play a central role in DR patients resistant towards the conventional medical treatments. However due to the byzantine interplay existing between nutrients and DR, the worth of nutrition in curbing this vision-threatening ocular morbidity remains silent. This review highlights how nutrients can halt DR development. A nutritional therapy, if adopted in the initial stages, can provide superior-efficacy over the current treatment modalities and can be a complementary, inexpensive, readily available, anodyne option to the clinically unmet requirement for preventing DR. Assessment of nutritional status is presently considered relevant in various clinical conditions except DR. Body Mass Index (BMI) conferred inconclusive results in DR subjects. Subjective Global Assessment (SGA) of nutritional status has recently furnished relevant association with DR status. By integrating nutritional strategies, the risk of developing DR can be reduced substantially. This review summarizes the subsisting knowledge on nutrition, potentially beneficial for preventing DR and sustaining good vision among diabetic subjects.
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21
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Li C, Miao X, Li F, Wang S, Liu Q, Wang Y, Sun J. Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9702820. [PMID: 28265339 PMCID: PMC5317113 DOI: 10.1155/2017/9702820] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/27/2016] [Accepted: 12/27/2016] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes and is the leading cause of blindness in young adults. Oxidative stress has been implicated as a critical cause of DR. Metabolic abnormalities induced by high-glucose levels are involved in the development of DR and appear to be influenced by oxidative stress. The imbalance between reactive oxygen species (ROS) production and the antioxidant defense system activates several oxidative stress-related mechanisms that promote the pathogenesis of DR. The damage caused by oxidative stress persists for a considerable time, even after the blood glucose concentration has returned to a normal level. Animal experiments have proved that the use of antioxidants is a beneficial therapeutic strategy for the treatment of DR, but more data are required from clinical trials. The aims of this review are to highlight the improvements to our understanding of the oxidative stress-related mechanisms underlying the development of DR and provide a summary of the main antioxidant therapy strategies used to treat the disease.
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Affiliation(s)
- Cheng Li
- The First Hospital of Jilin University, Changchun 130021, China
| | - Xiao Miao
- The Second Hospital of Jilin University, Changchun 130041, China
| | - Fengsheng Li
- General Hospital of the PLA Rocket Force, Beijing 100088, China
| | - Shudong Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Quan Liu
- The First Hospital of Jilin University, Changchun 130021, China
| | - Yonggang Wang
- The First Hospital of Jilin University, Changchun 130021, China
| | - Jian Sun
- The First Hospital of Jilin University, Changchun 130021, China
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22
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Suppression of NADPH Oxidase Activity May Slow the Expansion of Osteolytic Bone Metastases. Healthcare (Basel) 2016; 4:healthcare4030060. [PMID: 27571113 PMCID: PMC5041061 DOI: 10.3390/healthcare4030060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 12/28/2022] Open
Abstract
Lysophosphatidic acid (LPA), generated in the microenvironment of cancer cells, can drive the proliferation, invasion, and migration of cancer cells by activating G protein-coupled LPA receptors. Moreover, in cancer cells that have metastasized to bone, LPA signaling can promote osteolysis by inducing cancer cell production of cytokines, such as IL-6 and IL-8, which can stimulate osteoblasts to secrete RANKL, a key promoter of osteoclastogenesis. Indeed, in cancers prone to metastasize to bone, LPA appears to be a major driver of the expansion of osteolytic bone metastases. Activation of NADPH oxidase has been shown to play a mediating role in the signaling pathways by which LPA, as well as RANKL, promote osteolysis. In addition, there is reason to suspect that Nox4 activation is a mediator of the feed-forward mechanism whereby release of TGF-beta from bone matrix by osteolysis promotes expression of PTHrP in cancer cells, and thereby induces further osteolysis. Hence, measures which can down-regulate NADPH oxidase activity may have potential for slowing the expansion of osteolytic bone metastases in cancer patients. Phycocyanin and high-dose statins may have utility in this regard, and could be contemplated as complements to bisphosphonates or denosumab for the prevention and control of osteolytic lesions. Ingestion of omega-3-rich flaxseed or fish oil may also have potential for controlling osteolysis in cancer patients.
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23
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Klein R, Myers CE, Lee KE, Paterson AD, Cruickshanks KJ, Tsai MY, Gangnon RE, Klein BEK. Oxidized Low-Density Lipoprotein and the Incidence of Proliferative Diabetic Retinopathy and Clinically Significant Macular Edema Determined From Fundus Photographs. JAMA Ophthalmol 2015; 133:1054-61. [PMID: 26181138 DOI: 10.1001/jamaophthalmol.2015.2239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
IMPORTANCE Studies have shown oxidized low-density lipoprotein to be associated with the incidence of proliferative retinopathy and other complications of type 1 diabetes mellitus. Because low-risk interventions are available to modify oxidized low-density lipoprotein, it is important to examine the relationships between this factor and the incidence of proliferative retinopathy and of macular edema, 2 important causes of visual impairment in people with type 1 diabetes. OBJECTIVE To determine the association of oxidized low-density lipoprotein with the worsening of diabetic retinopathy and the incidence of proliferative retinopathy and of macular edema. DESIGN, SETTING, AND PARTICIPANTS Of 996 participants with type 1 diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy, 730 were examined up to 4 times (1990-1992, 1994-1996, 2005-2007, and 2012-2014) over 24 years and had assays of oxidized low-density lipoprotein and fundus photographs gradable for diabetic retinopathy and macular edema. Analyses started July 2014 and ended February 2015. MAIN OUTCOMES AND MEASURES Worsening of diabetic retinopathy, incidence of proliferative diabetic retinopathy, and incidence of macular edema as assessed via grading of color stereo film fundus photographs. The levels of oxidized low-density lipoprotein collected from serum samples at the time of each examination were measured in 2013 and 2014 from frozen serum. RESULTS The cohort at baseline had a mean (SD) level of oxidized low-density lipoprotein of 30.0 (8.5) U/L. While adjusting for duration of diabetes, glycated hemoglobin A1c level, and other factors, we found that neither the level of oxidized low-density lipoprotein at the beginning of a period nor the change in it over a certain period was associated with the incidence of proliferative diabetic retinopathy (hazard ratio [HR], 1.11 [95% CI, 0.91-1.35], P = .30; odds ratio [OR], 1.77 [95% CI, 0.99-3.17], P = .06), the incidence of macular edema (HR, 1.04 [95% CI, 0.83-1.29], P = .74; OR, 1.08 [95% CI, 0.44-2.61], P = .87), or the worsening of diabetic retinopathy (HR, 0.94 [95% CI, 0.83-1.07], P = .34; OR, 1.32 [95% CI, 0.83-2.09], P = .24). CONCLUSIONS AND RELEVANCE Our findings do not provide evidence for a relationship between increasing levels of serum oxidized low-density lipoprotein and the incidence of macular edema or the worsening of diabetic retinopathy in persons with type 1 diabetes. The potential increase in the HR for incident proliferative retinopathy, with an increase in oxidized low-density lipoprotein level over the preceding period, warrants further investigation of this relationship.
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Affiliation(s)
- Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison
| | - Chelsea E Myers
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison
| | - Kristine E Lee
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison
| | - Andrew D Paterson
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Karen J Cruickshanks
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison3Department of Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison
| | - Michael Y Tsai
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis
| | - Ronald E Gangnon
- Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison
| | - Barbara E K Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison
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24
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Schmidl D, Garhöfer G, Schmetterer L. Nutritional supplements in age-related macular degeneration. Acta Ophthalmol 2015; 93:105-21. [PMID: 25586104 DOI: 10.1111/aos.12650] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 11/28/2014] [Indexed: 12/22/2022]
Abstract
Age-related macular degeneration (AMD) is the most frequent cause of blindness in the Western World. While with new therapies that are directed towards vascular endothelial growth factor (VEGF), a potentially efficient treatment option for the wet form of the disease has been introduced, a therapeutic regimen for dry AMD is still lacking. There is evidence from several studies that oral intake of supplements is beneficial in preventing progression of the disease. Several formulations of micronutrients are currently available. The present review focuses on the role of supplements in the treatment and prevention of AMD and sums up the current knowledge about the most frequently used micronutrients. In addition, regulatory issues are discussed, and future directions for the role of supplementation in AMD are highlighted.
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Affiliation(s)
- Doreen Schmidl
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
- Center for Medical Physics and Biomedical Engineering; Medical University of Vienna; Vienna Austria
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25
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Zhang J, Deng H, Liu L, Liu X, Zuo X, Xu Q, Wu Z, Peng X, Ji A. α-Lipoic acid protects against hypoxia/reoxygenation-induced injury in human umbilical vein endothelial cells through suppression of apoptosis and autophagy. Mol Med Rep 2015; 12:180-6. [PMID: 25684163 PMCID: PMC4438966 DOI: 10.3892/mmr.2015.3351] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 11/14/2014] [Indexed: 01/16/2023] Open
Abstract
α-lipoic acid (ALA) is known as a powerful antioxidant, which has been reported to have protective effects against various cardiovascular diseases. The present study aimed to determine whether ALA pre- or post-treatment induced protective effects against hypoxia/reoxygenation-induced injury via inhibition of apoptosis and autophagy in human umbilical vein endothelial cells (HUVECs). In order to simulate the conditions of hypoxia/reoxygenation, HUVECs were subjected to 4 h of oxygen-glucose deprivation (OGD) followed by 12 h of reoxygenation. For the pre-treatment, ALA was added to the buffer 12 h prior to OGD, whereas for the post-treatment, ALA was added at the initiation of reoxygenation. The results demonstrated that ALA pre- or post-treatment significantly reduced lactate dehydrogenase (LDH) release induced through hypoxia/reoxygenation in HUVECs in a dose-dependent manner; of note, 1 mM ALA pre- or post-treatment exhibited the most potent protective effects. In addition, ALA significantly reduced hypoxia/reoxygenation-induced loss of mitochondrial membrane potential, apoptosis and the expression of cleaved caspase-3 in HUVECs. In the presence of the specific autophagy inhibitor 3-methyladenine, hypoxia/reoxygenation-induced apoptosis was significantly reduced. Furthermore, the formation of autophagosomes, cytosolic microtubule-associated protein 1A/1B-light chain 3 ratio and beclin1 levels significantly increased following hypoxia/reoxygenation injury; however, all of these effects were ameliorated following pre- or post-treatment with ALA. The results of the present study suggested that ALA may provide beneficial protection against hypoxia/reoxygenation-induced injury via attenuation of apoptosis and autophagy in HUVECs.
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Affiliation(s)
- Jingjing Zhang
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Houliang Deng
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Li Liu
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Xiaoxia Liu
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Xialin Zuo
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510260, P.R. China
| | - Qian Xu
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Zhuomin Wu
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
| | - Xiaobin Peng
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Aimin Ji
- Center for Drug Research and Development, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, P.R. China
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Berkowitz BA, Grady EM, Khetarpal N, Patel A, Roberts R. Oxidative stress and light-evoked responses of the posterior segment in a mouse model of diabetic retinopathy. Invest Ophthalmol Vis Sci 2015; 56:606-15. [PMID: 25574049 PMCID: PMC4309313 DOI: 10.1167/iovs.14-15687] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/12/2014] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To test the hypothesis that in a mouse model of diabetic retinopathy, oxidative stress is linked with impaired light-evoked expansion of choroidal thickness and subretinal space (SRS). METHODS We examined nondiabetic mice (wild-type, wt) with and without administration of manganese, nondiabetic mice deficient in rod phototransduction (transducin alpha knockout; GNAT1(-/-)), and diabetic mice (untreated or treated with the antioxidant α-lipoic acid [LPA]). Magnetic resonance imaging (MRI) was used to measure light-evoked increases in choroidal thickness and the apparent diffusion coefficient (ADC) at 88% to 100% depth into the retina (i.e., the SRS layer). RESULTS Choroidal thickness values were similar (P > 0.05) between all untreated nondiabetic dark-adapted groups and increased significantly (P < 0.05) with light; this expansion was subnormal (P < 0.05) in both diabetic groups. Apparent diffusion coefficient values in the SRS layer robustly increased (P < 0.05) in a light duration-dependent manner, and this effect was independent of the presence of Mn(2+). The light-stimulated increase in ADC at the location of the SRS was absent in GNAT1(-/-) and diabetic mice (P > 0.05). In diabetic mice, the light-dependent increase in SRS ADC was significantly (P < 0.05) restored with LPA. CONCLUSIONS Apparent diffusion coefficient MRI is a sensitive method for evaluating choroid thickness and its light-evoked expansion together with phototransduction-dependent changes in the SRS layer in mice in vivo. Because ADC MRI exploits an endogenous contrast mechanism, its translational potential is promising; it can also be performed in concert with manganese-enhanced MRI (MEMRI). Our data support a link between diabetes-related oxidative stress and rod, but not choroidal, pathophysiology.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
- Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
| | - Edmund Michael Grady
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Nikita Khetarpal
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Akshar Patel
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
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Mangialardi G, Spinetti G, Reni C, Madeddu P. Reactive oxygen species adversely impacts bone marrow microenvironment in diabetes. Antioxid Redox Signal 2014; 21:1620-33. [PMID: 25089632 PMCID: PMC4175424 DOI: 10.1089/ars.2014.5944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Significance: Patients with diabetes mellitus suffer an excess of cardiovascular complications and recover worse from them as compared with their nondiabetic peers. It is well known that microangiopathy is the cause of renal damage, blindness, and heart attacks in patients with diabetes. This review highlights molecular deficits in stem cells and a supporting microenvironment, which can be traced back to oxidative stress and ultimately reduce stem cells therapeutic potential in diabetic patients. RECENT ADVANCES New research has shown that increased oxidative stress contributes to inducing microangiopathy in bone marrow (BM), the tissue contained inside the bones and the main source of stem cells. These precious cells not only replace old blood cells but also exert an important reparative function after acute injuries and heart attacks. CRITICAL ISSUES The starvation of BM as a consequence of microangiopathy can lead to a less efficient healing in diabetic patients with ischemic complications. Furthermore, stem cells from a patient's BM are the most used in regenerative medicine trials to mend hearts damaged by heart attacks. FUTURE DIRECTIONS A deeper understanding of redox signaling in BM stem cells will lead to new modalities for preserving local and systemic homeostasis and to more effective treatments of diabetic cardiovascular complications.
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Affiliation(s)
- Giuseppe Mangialardi
- 1 Regenerative Medicine Section, Bristol Heart Institute, School of Clinical Sciences, University of Bristol , Bristol, United Kingdom
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Park SY, Kim YA, Hong YH, Moon MK, Koo BK, Kim TW. Up-regulation of the receptor for advanced glycation end products in the skin biopsy specimens of patients with severe diabetic neuropathy. J Clin Neurol 2014; 10:334-41. [PMID: 25324883 PMCID: PMC4198715 DOI: 10.3988/jcn.2014.10.4.334] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 02/17/2014] [Accepted: 02/17/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE The receptor for advanced glycation end products (RAGE) may contribute to the development of diabetic neuropathy. To assess its relevance in humans, this study examined the expression of RAGE in the skin biopsy samples of patients with diabetes mellitus, and investigated its correlation with intraepidermal nerve-fiber density (IENFD) and clinical measures of neuropathy severity. METHODS Forty-four patients who either had type 2 diabetes or were prediabetes underwent clinical evaluation and a 3-mm skin punch biopsy. The clinical severity of their neuropathy was assessed using the Michigan Diabetic Neuropathy Score. IENFD was measured along with immunohistochemical staining for RAGE in 29 skin biopsy samples. The expression of RAGE was also quantified by real-time reverse-transcription PCR in the remaining 15 patients. RESULTS RAGE was localized mostly in the dermal and subcutaneous vascular endothelia. The staining was more intense in patients with a lower IENFD (p=0.004). The quantity of RAGE mRNA was significantly higher in patients with severe neuropathy than in those with no or mild neuropathy (p=0.003). The up-regulation of RAGE was related to dyslipidemia and diabetic nephropathy. There was a trend toward decreased sural nerve action-potential amplitude and slowed peroneal motor-nerve conduction with increasing RAGE expression. CONCLUSIONS The findings of this study demonstrate up-regulation of RAGE in skin biopsy samples from patients with diabetic neuropathy, supporting a pathogenic role of RAGE in the development of diabetic neuropathy.
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Affiliation(s)
- Su-Yeon Park
- Department of Neurology, Korea Cancer Center Hospital, Seoul, Korea
| | - Young-A Kim
- Department of Pathology, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Yoon-Ho Hong
- Department of Neurology, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Min-Kyong Moon
- Department of Endocrinology and Metabolism, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Bo-Kyeong Koo
- Department of Endocrinology and Metabolism, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Tae Wan Kim
- Department of Ophthalmology, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
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Zhao L, Wang C, Song D, Li Y, Song Y, Su G, Dunaief JL. Systemic administration of the antioxidant/iron chelator α-lipoic acid protects against light-induced photoreceptor degeneration in the mouse retina. Invest Ophthalmol Vis Sci 2014; 55:5979-88. [PMID: 25146987 DOI: 10.1167/iovs.14-15025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
PURPOSE Oxidative stress and inflammation have key roles in the light damage (LD) model of retinal degeneration as well as in age-related macular degeneration (AMD). We sought to determine if lipoic acid (LA), an antioxidant and iron chelator, protects the retina against LD. METHODS Balb/c mice were treated with LA or control saline via intraperitoneal injection, and then were placed in constant cool white light-emitting diode (LED) light (10,000 lux) for 4 hours. Retinas were evaluated at several time points after LD. Photoreceptor apoptosis was assessed using the TUNEL assay. Retinal function was analyzed via electroretinography (ERG). Retinal degeneration was assessed after LD by optical coherence tomography (OCT), TUNEL analysis, and histology. The mRNAs of several oxidative stress, inflammation, and iron-related genes were quantified by quantitative PCR (qPCR). RESULTS The LD resulted in substantial photoreceptor-specific cell death. Dosing with LA protected photoreceptors, decreasing the numbers of TUNEL-positive photoreceptors and increasing the number of surviving photoreceptors. The retinal mRNA levels of genes indicating oxidative stress, inflammation, and iron accumulation were lower following LD in mice treated with LA than in control mice. The ERG analysis demonstrated functional protection by LA. CONCLUSIONS Systemic LA is protective against light-induced retinal degeneration. Since this agent already has proven protective in other retinal degeneration models, and is safe and protective against diabetic neuropathy in patients, it is worthy of consideration for a human clinical trial against retinal degeneration or AMD.
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Affiliation(s)
- Liangliang Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Chenguang Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Delu Song
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Yafeng Li
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Ying Song
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Guanfang Su
- Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Joshua L Dunaief
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Gomes MB, Negrato CA. Alpha-lipoic acid as a pleiotropic compound with potential therapeutic use in diabetes and other chronic diseases. Diabetol Metab Syndr 2014; 6:80. [PMID: 25104975 PMCID: PMC4124142 DOI: 10.1186/1758-5996-6-80] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/11/2014] [Indexed: 02/07/2023] Open
Abstract
Alpha-lipoic acid is a naturally occurring substance, essential for the function of different enzymes that take part in mitochondria's oxidative metabolism. It is believed that alpha-lipoic acid or its reduced form, dihydrolipoic acid have many biochemical functions acting as biological antioxidants, as metal chelators, reducers of the oxidized forms of other antioxidant agents such as vitamin C and E, and modulator of the signaling transduction of several pathways. These above-mentioned actions have been shown in experimental studies emphasizing the use of alpha-lipoic acid as a potential therapeutic agent for many chronic diseases with great epidemiological as well economic and social impact such as brain diseases and cognitive dysfunctions like Alzheimer disease, obesity, nonalcoholic fatty liver disease, burning mouth syndrome, cardiovascular disease, hypertension, some types of cancer, glaucoma and osteoporosis. Many conflicting data have been found concerning the clinical use of alpha-lipoic acid in the treatment of diabetes and of diabetes-related chronic complications such as retinopathy, nephropathy, neuropathy, wound healing and diabetic cardiovascular autonomic neuropathy. The most frequent clinical condition in which alpha-lipoic acid has been studied was in the management of diabetic peripheral neuropathy in patients with type 1 as well type 2 diabetes. Considering that oxidative stress, a imbalance between pro and antioxidants with excessive production of reactive oxygen species, is a factor in the development of many diseases and that alpha-lipoic acid, a natural thiol antioxidant, has been shown to have beneficial effects on oxidative stress parameters in various tissues we wrote this article in order to make an up-to-date review of current thinking regarding alpha-lipoic acid and its use as an antioxidant drug therapy for a myriad of diseases that could have potential benefits from its use.
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Affiliation(s)
- Marilia Brito Gomes
- />Department of Internal Medicine, Diabetes Unit, State University Hospital of Rio de Janeiro, Avenida 28 de Setembro, 77, 3° andar CEP 20.551-030, Rio de Janeiro, Brazil
| | - Carlos Antonio Negrato
- />Department of Internal Medicine, Bauru’s Diabetics Association, 17012-433 Bauru, São Paulo, Brazil
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Effect of the administration of alpha-lipoic acid on contrast sensitivity in patients with type 1 and type 2 diabetes. Mediators Inflamm 2014; 2014:131538. [PMID: 24665163 PMCID: PMC3934387 DOI: 10.1155/2014/131538] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 11/28/2013] [Accepted: 12/24/2013] [Indexed: 01/15/2023] Open
Abstract
The aim of this study was to estimate the effects of oral supplementation of alpha-lipoic acid (ALA) on contrast sensitivity (CS) in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). The study included 12 patients with T1DM aged 43±12 years, 48 patients with T2DM aged 59±10 years, and 20 control subjects aged 33±8 years. Patients from each studied group, including the control group, were randomly assigned to receive 300 mg of ALA orally once daily for 3 months. CS was evaluated with the Functional Acuity Contrast Test (FACT, Stereo Optical). In the group of patients with T1DM receiving ALA for 3 months CS remained stable and improved in those with T2DM. Reduction of CS in both T1DM and T2DM patients without alpha-lipoic acid supplementation was observed. In the control group on alpha-lipoic acid supplementation, CS improvement was noticed at one spatial frequency. Changes in the CS were observed, despite stable visual acuity and eye fundus image in all studied subjects. Our study demonstrated that oral administration of alpha-lipoic acid had influence on CS in both T1DM and T2DM patients.
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32
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Microvascular complications and diabetic retinopathy: recent advances and future implications. Future Med Chem 2013; 5:301-14. [PMID: 23464520 DOI: 10.4155/fmc.12.206] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Retinal microvascular alterations have been observed during diabetic retinopathy (DR) due to the retinal susceptibility towards subtle pathological alterations. Therefore, retinal microvascular pathology is essential to understand the nature of retinal degenerations during DR. In this review, the role of retinal microvasculature complications during progression of DR, along with recent efforts to normalize such alterations for better therapeutic outcome, will be underlined. In addition, current therapeutics and future directions for advancement of standard treatment for DR patients will be discussed.
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Nebbioso M, Pranno F, Pescosolido N. Lipoic acid in animal models and clinical use in diabetic retinopathy. Expert Opin Pharmacother 2013; 14:1829-38. [DOI: 10.1517/14656566.2013.813483] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Abstract
Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are the leading causes of blindness in adults. The impact of these conditions on the quality of life is increasing in significance with a rise in life expectancy. The role of hyperglycemia, oxidative stress and inflammatory responses in the development and/or progression of DR and AMD, and several other sight threatening ocular diseases, is well established. In proliferative retinopathy, signals sent by the retina for nourishment, triggers the growth of fragile and abnormal blood vessels. Changes in ocular pressure may lead to rupture of these blood vessels causing severe vision problems. Recent in vitro and preclinical studies demonstrate that certain phytochemicals possessing potent antioxidant and anti-inflammatory activity and ocular blood flow enhancing properties may be very useful in the treatment of, or as a prophylactic measure for, DR and AMD. Apart from these properties they have also been investigated for their anti-bacterial, hormonal, enzyme stimulation, and anti-angiogenic activities. The attractive aspect of these potential therapeutic candidates is that they can act on multiple pathways identified in the etiology of DR, AMD, cataract and other ocular diseases. However, results from clinical trials have been somewhat ambiguous, raising questions about the concentrations of these bioflavonoids achieved in the neural retina following oral administration. Unfortunately, as of date, an efficient noninvasive means to deliver therapeutic agents/candidates to the back-of-the eye is still not available. This review examines some of these promising natural agents and discusses the challenges encountered in delivering them to the posterior segment ocular tissues through the oral route.
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35
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The effect of lipoic acid on wound healing in a full thickness uterine injury model in rats. J Mol Histol 2013; 44:339-45. [DOI: 10.1007/s10735-013-9485-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/19/2013] [Indexed: 10/27/2022]
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Mangialardi G, Katare R, Oikawa A, Meloni M, Reni C, Emanueli C, Madeddu P. Diabetes causes bone marrow endothelial barrier dysfunction by activation of the RhoA-Rho-associated kinase signaling pathway. Arterioscler Thromb Vasc Biol 2013; 33:555-64. [PMID: 23307872 DOI: 10.1161/atvbaha.112.300424] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Diabetes mellitus causes bone marrow (BM) microangiopathy. This study aimed to investigate the mechanisms responsible for BM endothelial dysfunction in diabetes mellitus. METHODS AND RESULTS The analysis of differentially expressed transcripts in BM endothelial cells (BMECs) from type-1 diabetic and nondiabetic mice showed an effect of diabetes mellitus on signaling pathways controlling cell death, migration, and cytoskeletal rearrangement. Type-1 diabetic-BMECs displayed high reactive oxygen species levels, increased expression and activity of RhoA and its associated protein kinases Rho-associated kinase 1/Rho-associated kinase 2, and reduced Akt phosphorylation/activity. Likewise, diabetes mellitus impaired Akt-related BMEC functions, such as migration, network formation, and angiocrine factor-releasing activity, and increased vascular permeability. Moreover, high glucose disrupted BMEC contacts through Src tyrosine kinase phosphorylation of vascular endothelial cadherin. These alterations were prevented by constitutively active Akt (myristoylated Akt), Rho-associated kinase inhibitor Y-27632, and Src inhibitors. Insulin replacement restored BMEC abundance, as assessed by flow cytometry analysis of the endothelial marker MECA32, and endothelial barrier function in BM of type-1 diabetic mice. CONCLUSIONS Redox-dependent activation of RhoA/Rho-associated kinase and Src/vascular endothelial cadherin signaling pathways, together with Akt inactivation, contribute to endothelial dysfunction in diabetic BM. Metabolic control is crucial for maintenance of endothelial cell homeostasis and endothelial barrier function in BM of diabetic mice.
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Affiliation(s)
- Giuseppe Mangialardi
- Experimental Cardiovascular Medicine, Regenerative Medicine Section Bristol Heart Institute, School of Clinical Sciences University of Bristol, Bristol, UK
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37
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Sun LQ, Chen YY, Wang X, Li XJ, Xue B, Qu L, Zhang TT, Mu YM, Lu JM. The protective effect of Alpha lipoic acid on Schwann cells exposed to constant or intermittent high glucose. Biochem Pharmacol 2012; 84:961-73. [DOI: 10.1016/j.bcp.2012.07.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/02/2012] [Accepted: 07/05/2012] [Indexed: 12/27/2022]
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Abstract
Understanding the role of oxidative injury will allow for therapy with agents that scavenge ROS (reactive oxygen species) and antioxidants in the management of several diseases related to free radical damage. The majority of free radicals are generated by mitochondria as a consequence of the mitochondrial cycle, whereas free radical accumulation is limited by the action of a variety of antioxidant processes that reside in every cell. In the present review, we provide an overview of the mitochondrial generation of ROS and discuss the role of ROS in the regulation of endothelial and adipocyte function. Moreover, we also discuss recent findings on the role of ROS in sepsis, cerebral ataxia and stroke. These results provide avenues for the therapeutic potential of antioxidants in a variety of diseases.
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Nebbioso M, Federici M, Rusciano D, Evangelista M, Pescosolido N. Oxidative stress in preretinopathic diabetes subjects and antioxidants. Diabetes Technol Ther 2012; 14:257-63. [PMID: 22044044 DOI: 10.1089/dia.2011.0172] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND This study assessed the effect of a systemic oral treatment with antioxidants (AOs) in preretinopathic diabetes (PRD) patients, through the evaluation of oxidative stress in plasma and changes in the full-field electroretinogram (ERG). METHODS Thirty-two PRD subjects with good metabolic control were recruited. Patients were randomized in two groups, one of which received oral AO treatment with α-lipoic acid at 400 mg/day in association with genistein and vitamins, whereas the other group received a placebo. Free radicals and the AO barrier were evaluated in plasma with the Free Radical Analytical System 4 instrument (H&D srl, Parma, Italy), and the same day the electrophysiological response was measured by ERG. These analyses were performed at enrollment and after 30 days of treatment. RESULTS Statistically significant increases of plasma AO levels and ERG oscillatory potential values were observed in the group treated with AO, but not in the control group. CONCLUSIONS Results of this preliminary study suggest that an oral treatment with AOs in PRD subjects may have a protective effect on retinal cells, as detected by ERG analysis, through the strengthening of the plasma AO barrier.
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Affiliation(s)
- Marcella Nebbioso
- Department of Sense Organs, Sapienza University of Rome, Rome, Italy.
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Mijnhout GS, Kollen BJ, Alkhalaf A, Kleefstra N, Bilo HJG. Alpha lipoic Acid for symptomatic peripheral neuropathy in patients with diabetes: a meta-analysis of randomized controlled trials. Int J Endocrinol 2012; 2012:456279. [PMID: 22331979 PMCID: PMC3272801 DOI: 10.1155/2012/456279] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 10/10/2011] [Indexed: 02/06/2023] Open
Abstract
Objective. We performed a systematic review of the literature to evaluate the effects of alpha lipoic acid for symptomatic peripheral neuropathy in patients with diabetes mellitus. Research design and methods. The databases MEDLINE and EMBASE were searched using the key words "lipoic acid", "thioctic acid", "diabet∗", and the MeSH-terms "thioctic acid" and "diabetes mellitus". Randomised controlled trials using the TSS score as the outcome measure were selected and assessed for their methodological quality. Study selection and quality assessment were performed independently by three observers. Results. Overall, the pooled standardized mean difference estimated from all trials revealed a reduction in TSS scores of -2.26 (CI: -3.12 to -1.41; P = 0.00001) in favour of alpha lipoic acid administration. Subgroup analyses of oral administration (-1.78 CI: -2.45 to -1.10; P = 0.00001) and intravenous administration (-2.81 CI: -4.16 to -1.46; P = 0.0001) confirmed the robustness of the overall result. Conclusions. When given intravenously at a dosage of 600 mg/day over a period of 3 weeks, alpha lipoic acid leads to a significant and clinically relevant reduction in neuropathic pain (grade of recommendation A). It is unclear if the significant improvements seen after 3-5 weeks of oral administration at a dosage of >600 mg/day are clinically relevant.
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Affiliation(s)
- Gerritje S. Mijnhout
- Department of Internal Medicine, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
| | - Boudewijn J. Kollen
- Department of General Practice, University Medical Centre Groningen, University of Groningen, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Alaa Alkhalaf
- Department of Internal Medicine, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
- Department of Internal Medicine, University Medical Centre Groningen, University of Groningen, P.O. Box 30001, 9700 RB Groningen, The Netherlands
- Diabetes Centre, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
| | - Nanno Kleefstra
- Department of Internal Medicine, University Medical Centre Groningen, University of Groningen, P.O. Box 30001, 9700 RB Groningen, The Netherlands
- Diabetes Centre, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
- Langerhans Medical Research Group, P.O. Box 21, 4254 ZG Sleeuwijk, The Netherlands
| | - Henk J. G. Bilo
- Department of Internal Medicine, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
- Department of Internal Medicine, University Medical Centre Groningen, University of Groningen, P.O. Box 30001, 9700 RB Groningen, The Netherlands
- Diabetes Centre, Isala Clinics, P.O. Box 10400, 8000 GK Zwolle, The Netherlands
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Kowluru RA, Zhong Q. Beyond AREDS: is there a place for antioxidant therapy in the prevention/treatment of eye disease? Invest Ophthalmol Vis Sci 2011; 52:8665-71. [PMID: 22065212 DOI: 10.1167/iovs.10-6768] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Age-related macular degeneration (AMD), the major cause of blindness in adults (65 years of age and older), and diabetic retinopathy, the major cause of blindness in working adults, are chronic, progressive diseases with multifaceted etiologies that are not fully understood. Progression and lack of treatment of both diseases may lead to the advanced stage with neovascularization. Although the detailed cellular mechanisms leading to the development of AMD and diabetic retinopathy remain elusive, oxidative damage to the retina and its pigment epithelium are considered to be involved. Clinical studies have shown that the progression of AMD can be slowed down by nutritional antioxidants, but trials with antioxidants for diabetic retinopathy (very limited in number) have been inconclusive. Long-term administration of the AREDS antioxidants, the same nutritional antioxidants that have been demonstrated to slow the progression of AMD, have yielded exciting results in preventing the pathogenesis of retinopathy in diabetic rodents. These results suggest the merit of testing the AREDS antioxidants in a clinical trial to prevent the development and/or progression of diabetic retinopathy, with the possibility of reducing the impact of this common vision-threatening disease.
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Affiliation(s)
- Renu A Kowluru
- Kresge Eye Institute, Wayne State University, Detroit, Michigan 48201, USA.
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Morgado C, Pereira-Terra P, Tavares I. α-Lipoic acid normalizes nociceptive neuronal activity at the spinal cord of diabetic rats. Diabetes Obes Metab 2011; 13:736-41. [PMID: 21435143 DOI: 10.1111/j.1463-1326.2011.01399.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM To evaluate the effects of antioxidant treatment of streptozotocin (STZ)-diabetic rats with α-lipoic acid (α-LA) in neuronal and microglial activation at the spinal cord, an important relay station of nociceptive transmission. Because of the role of the potassium chloride co-transporter 2 (KCC2) in neuronal activation at the spinal cord and the influence of microglia in KCC2 expression, we also evaluated the effects of α-LA in KCC2 expression at the spinal cord. METHODS Four weeks after STZ injection, the rats received daily intraperitoneal injections of α-LA (100 mg/kg), during 2 weeks. Mechanical nociception was evaluated before and after α-LA treatment. Spinal cords were immunoreacted against 8-OH-dG (marker of oxidative stress damage), Fos (marker of neuronal activation) and CD11b (marker of microglia). KCC2 expression was evaluated by immunohistochemistry and western blotting. RESULTS Treatment with α-LA decreased the 8-OH-dG and Fos expressions to controls' levels, but did not affect CD11b. Treatment with α-LA alleviated mechanical hyperalgesia and partially corrected KCC2 expression. CONCLUSIONS This study shows that neuronal hyperactivity at the spinal cord of STZ-diabetic rats can be corrected by α-LA, which may account for alleviation of mechanical hyperalgesia. These effects are probably partially mediated by KCC2, but are independent from microglia.
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Affiliation(s)
- C Morgado
- Institute of Histology and Embryology of Faculty of Medicine of Porto and IBMC, University of Porto, Porto, Portugal
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Haritoglou C, Gerss J, Hammes HP, Kampik A, Ulbig MW. Alpha-Lipoic Acid for the Prevention of Diabetic Macular Edema. Ophthalmologica 2011; 226:127-37. [DOI: 10.1159/000329470] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 05/04/2011] [Indexed: 02/01/2023]
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Tabassum H, Parvez S, Pasha ST, Banerjee BD, Raisuddin S. Protective effect of lipoic acid against methotrexate-induced oxidative stress in liver mitochondria. Food Chem Toxicol 2010; 48:1973-9. [DOI: 10.1016/j.fct.2010.04.047] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/30/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
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Wang Q, Pfister F, Dorn-Beineke A, vom Hagen F, Lin J, Feng Y, Hammes HP. Low-dose erythropoietin inhibits oxidative stress and early vascular changes in the experimental diabetic retina. Diabetologia 2010; 53:1227-38. [PMID: 20339831 DOI: 10.1007/s00125-010-1727-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 02/03/2010] [Indexed: 10/19/2022]
Abstract
AIMS/HYPOTHESIS Diabetic retinopathy is the result of increased oxidative and nitrosative stress induced by chronic hyperglycaemia, and affects the vasculature and the neuroglia. Erythropoietin is a neuroprotective and an endothelial survival factor. We assessed the effect of suberythropoietic epoetin delta doses on variables of oxidative stress in target tissues of diabetic complications and on pericyte loss in the diabetic retina. METHODS We administered epoetin delta to streptozotocin-induced diabetic Wistar rats at doses of 384 IU/kg body weight once weekly or 128 IU/kg body weight three times a week. The treatment lasted for 3 months. Oxidative stress and formation of AGEs were assessed by immunoblotting, expression of Ang-2 (also known as Angpt2) by RT-PCR, activation of protein kinase B (AKT) and heat shock protein (HSP)-27 levels by immunofluorescence, and incipient retinal vascular changes by quantitative morphometry of retinal digest preparations. RESULTS Diabetes increased variables of oxidative stress and nitrosative stress (N(epsilon)-carboxymethyl-lysine, nitrotyrosine and methylglyoxal-type AGEs) in retina, kidney and heart of diabetic rats. Epoetin delta reduced oxidative and nitrosative stress in all tissues, and AGEs in the retina. It also reduced increased retinal Ang-2 expression and pericyte loss, and ameliorated p-AKT and HSP-27 levels. CONCLUSIONS/INTERPRETATION Epoetin delta has antioxidative properties in organs affected by diabetes and may prevent incipient microvascular damage in the diabetic retina.
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Affiliation(s)
- Q Wang
- 5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
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Pazdro R, Burgess JR. The role of vitamin E and oxidative stress in diabetes complications. Mech Ageing Dev 2010; 131:276-86. [PMID: 20307566 DOI: 10.1016/j.mad.2010.03.005] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 03/04/2010] [Accepted: 03/10/2010] [Indexed: 02/07/2023]
Abstract
Diabetes is a disease characterized by poor glycemic control for which risk of the type 2 form increases with age. A rise in blood glucose concentration causes increased oxidative stress which contributes to the development and progression of diabetes-associated complications. Studies have shown that primary antioxidants or genetic manipulation of antioxidant defenses can at least partially ameliorate this oxidative stress and consequentially, reduce severity of diabetic complications in animal models. Data from humans is less clear and will be summarized in this review. We highlight results from studies performed to investigate the role of vitamin E in preventing diabetes-induced oxidative damage in cell culture, animal models, and human participants, and summarize evidence testing whether this nutrient has an effect on outcomes related to the diabetic complications of nephropathy, retinopathy, and neuropathy. The most compelling evidence for an effect of vitamin E in diabetes is on protection against lipid peroxidation, whereas effects on protein and DNA oxidation are less pronounced. More studies are required to make definitive conclusions about the effect of vitamin E treatment on diabetes complications in human subjects.
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Affiliation(s)
- Robert Pazdro
- Department of Foods and Nutrition, Purdue University, 700 West State Street, West Lafayette, IN 47907, USA
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Bashan N, Kovsan J, Kachko I, Ovadia H, Rudich A. Positive and negative regulation of insulin signaling by reactive oxygen and nitrogen species. Physiol Rev 2009; 89:27-71. [PMID: 19126754 DOI: 10.1152/physrev.00014.2008] [Citation(s) in RCA: 351] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Regulated production of reactive oxygen species (ROS)/reactive nitrogen species (RNS) adequately balanced by antioxidant systems is a prerequisite for the participation of these active substances in physiological processes, including insulin action. Yet, increasing evidence implicates ROS and RNS as negative regulators of insulin signaling, rendering them putative mediators in the development of insulin resistance, a common endocrine abnormality that accompanies obesity and is a risk factor of type 2 diabetes. This review deals with this dual, seemingly contradictory, function of ROS and RNS in regulating insulin action: the major processes for ROS and RNS generation and detoxification are presented, and a critical review of the evidence that they participate in the positive and negative regulation of insulin action is provided. The cellular and molecular mechanisms by which ROS and RNS are thought to participate in normal insulin action and in the induction of insulin resistance are then described. Finally, we explore the potential usefulness and the challenges in modulating the oxidant-antioxidant balance as a potentially promising, but currently disappointing, means of improving insulin action in insulin resistance-associated conditions, leading causes of human morbidity and mortality of our era.
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Affiliation(s)
- Nava Bashan
- Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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Szabo C. Role of nitrosative stress in the pathogenesis of diabetic vascular dysfunction. Br J Pharmacol 2009; 156:713-27. [PMID: 19210748 DOI: 10.1111/j.1476-5381.2008.00086.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Here we overview the role of reactive nitrogen species (nitrosative stress) and associated pathways in the pathogenesis of diabetic vascular complications. Increased extracellular glucose concentration, a principal feature of diabetes mellitus, induces a dysregulation of reactive oxygen and nitrogen generating pathways. These processes lead to a loss of the vascular endothelium to produce biologically active nitric oxide (NO), which impairs vascular relaxations. Mitochondria play a crucial role in this process: endothelial cells placed in increase extracellular glucose respond with a marked increase in mitochondrial superoxide formation. Superoxide, when combining with NO generated by the endothelial cells (produced by the endothelial isoform of NO synthase), leads to the formation of peroxynitrite, a cytotoxic oxidant. Reactive oxygen and nitrogen species trigger endothelial cell dysfunction through a multitude of mechanisms including substrate depletion and uncoupling of endothelial isoform of NO synthase. Another pathomechanism involves DNA strand breakage and activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP). PARP-mediated poly(ADP-ribosyl)ation and inhibition of glyceraldehyde-3-phosphate dehydrogenase importantly contributes to the development of diabetic vascular complications: it induces activation of multiple pathways of injury including activation of nuclear factor kappa B, activation of protein kinase C and generation of intracellular advanced glycation end products. Reactive species generation and PARP play key roles in the pathogenesis of 'glucose memory' and in the development of injury in endothelial cells exposed to alternating high/low glucose concentrations.
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Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555-0833, USA.
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Szabo C. Role of nitrosative stress in the pathogenesis of diabetic vascular dysfunction. Br J Pharmacol 2009. [PMID: 19210748 DOI: 10.111/j.1476-5381.2008.00086.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Here we overview the role of reactive nitrogen species (nitrosative stress) and associated pathways in the pathogenesis of diabetic vascular complications. Increased extracellular glucose concentration, a principal feature of diabetes mellitus, induces a dysregulation of reactive oxygen and nitrogen generating pathways. These processes lead to a loss of the vascular endothelium to produce biologically active nitric oxide (NO), which impairs vascular relaxations. Mitochondria play a crucial role in this process: endothelial cells placed in increase extracellular glucose respond with a marked increase in mitochondrial superoxide formation. Superoxide, when combining with NO generated by the endothelial cells (produced by the endothelial isoform of NO synthase), leads to the formation of peroxynitrite, a cytotoxic oxidant. Reactive oxygen and nitrogen species trigger endothelial cell dysfunction through a multitude of mechanisms including substrate depletion and uncoupling of endothelial isoform of NO synthase. Another pathomechanism involves DNA strand breakage and activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP). PARP-mediated poly(ADP-ribosyl)ation and inhibition of glyceraldehyde-3-phosphate dehydrogenase importantly contributes to the development of diabetic vascular complications: it induces activation of multiple pathways of injury including activation of nuclear factor kappa B, activation of protein kinase C and generation of intracellular advanced glycation end products. Reactive species generation and PARP play key roles in the pathogenesis of 'glucose memory' and in the development of injury in endothelial cells exposed to alternating high/low glucose concentrations.
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Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555-0833, USA.
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Tsai GY, Cui JZ, Syed H, Xia Z, Ozerdem U, McNeill JH, Matsubara JA. Effect of N-acetylcysteine on the early expression of inflammatory markers in the retina and plasma of diabetic rats. Clin Exp Ophthalmol 2009; 37:223-31. [PMID: 19723131 DOI: 10.1111/j.1442-9071.2009.02000.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE The aim of this study is to investigate markers of inflammation and oxidative stress in an early model of diabetic retinopathy, correlate retinal and plasma results and evaluate the influence of treatment by N-acetylcysteine (NAC), a free radical scavenger. METHODS Four groups were studied: control (C), streptozotocin (STZ)-induced diabetic rats (D), STZ rats following 8 weeks of NAC (DT), and control rats following 8 weeks of NAC (CT). Plasma levels of free 15-F2t-isoprostane (15-F-2t-IsoP), superoxide dismutase (SOD) and tumour necrosis factor-alpha (TNF-alpha) were obtained. Primary antibodies against macrophages (ED-1), microglia (Ox-42), pericytes (NG-2), endothelial and perivascular cells (IB-4), haem oxygenase 1 (HO-1) and vascular endothelial growth factor (VEGF) were used. RESULTS Expression of NG-2 was robust in C, CT, DT, and mild in D. The intensity of IB-4 was higher in D and DT compared with the C and CT. Ox-42 and ED-1 expression was higher in the D than in the DT, C or CT. Expression of VEGF and HO-1 was non-specific across the four groups. Plasma levels of 15-F-2t-IsoP and TNF-alpha were higher in the D as compared with the C, CT and DT. SOD levels were lower in the D when compared with the C, CT and D. CONCLUSIONS Macrophage/microglia activation, pericyte loss and endothelial/perivascular cell changes occur early in the pathogenesis of DR. These changes are associated with an increase in plasma markers of oxidative stress and inflammation and are minimized by treatment with NAC. The results suggest that therapies that reduce free radicals will help minimize the early events in diabetic retinopathy in the STZ model.
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Affiliation(s)
- Gina Y Tsai
- Ophthalmology and Visual Sciences, Faculty of Medicine, University of British Columbia, Columbia, Canada
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