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Tang Q, Buonfiglio F, Böhm EW, Zhang L, Pfeiffer N, Korb CA, Gericke A. Diabetic Retinopathy: New Treatment Approaches Targeting Redox and Immune Mechanisms. Antioxidants (Basel) 2024; 13:594. [PMID: 38790699 PMCID: PMC11117924 DOI: 10.3390/antiox13050594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Diabetic retinopathy (DR) represents a severe complication of diabetes mellitus, characterized by irreversible visual impairment resulting from microvascular abnormalities. Since the global prevalence of diabetes continues to escalate, DR has emerged as a prominent area of research interest. The development and progression of DR encompass a complex interplay of pathological and physiological mechanisms, such as high glucose-induced oxidative stress, immune responses, vascular endothelial dysfunction, as well as damage to retinal neurons. Recent years have unveiled the involvement of genomic and epigenetic factors in the formation of DR mechanisms. At present, extensive research explores the potential of biomarkers such as cytokines, molecular and cell therapies, antioxidant interventions, and gene therapy for DR treatment. Notably, certain drugs, such as anti-VEGF agents, antioxidants, inhibitors of inflammatory responses, and protein kinase C (PKC)-β inhibitors, have demonstrated promising outcomes in clinical trials. Within this context, this review article aims to introduce the recent molecular research on DR and highlight the current progress in the field, with a particular focus on the emerging and experimental treatment strategies targeting the immune and redox signaling pathways.
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Affiliation(s)
- Qi Tang
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (F.B.); (E.W.B.); (L.Z.); (N.P.); (C.A.K.)
| | | | | | | | | | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (F.B.); (E.W.B.); (L.Z.); (N.P.); (C.A.K.)
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Zhang C, Gu L, Xie H, Liu Y, Huang P, Zhang J, Luo D, Zhang J. Glucose transport, transporters and metabolism in diabetic retinopathy. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166995. [PMID: 38142757 DOI: 10.1016/j.bbadis.2023.166995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/02/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Diabetic retinopathy (DR) is the most common reason for blindness in working-age individuals globally. Prolonged high blood glucose is a main causative factor for DR development, and glucose transport is prerequisite for the disturbances in DR caused by hyperglycemia. Glucose transport is mediated by its transporters, including the facilitated transporters (glucose transporter, GLUTs), the "active" glucose transporters (sodium-dependent glucose transporters, SGLTs), and the SLC50 family of uniporters (sugars will eventually be exported transporters, SWEETs). Glucose transport across the blood-retinal barrier (BRB) is crucial for nourishing the neuronal retina in the context of retinal physiology. This physiological process primarily relies on GLUTs and SGLTs, which mediate the glucose transportation across both the cell membrane of retinal capillary endothelial cells and the retinal pigment epithelium (RPE). Under diabetic conditions, increased accumulation of extracellular glucose enhances the retinal cellular glucose uptake and metabolism via both glycolysis and glycolytic side branches, which activates several biochemical pathways, including the protein kinase C (PKC), advanced glycation end-products (AGEs), polyol pathway and hexosamine biosynthetic pathway (HBP). These activated biochemical pathways further increase the production of reactive oxygen species (ROS), leading to oxidative stress and activation of Poly (ADP-ribose) polymerase (PARP). The activated PARP further affects all the cellular components in the retina, and finally resulting in microangiopathy, neurodegeneration and low-to-moderate grade inflammation in DR. This review aims to discuss the changes of glucose transport, glucose transporters, as well as its metabolism in DR, which influences the retinal neurovascular unit (NVU) and implies the possible therapeutic strategies for treating DR.
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Affiliation(s)
- Chaoyang Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Limin Gu
- Department of Ophthalmology, Shanghai Aier Eye Hospital, Shanghai, China.
| | - Hai Xie
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Yan Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Peirong Huang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Jingting Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Dawei Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases; Shanghai Clinical Research Center for Eye Diseases; Shanghai Key Clinical Specialty; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai Eye Research Institute, Shanghai, China.
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Priyadarshini A, Madan R, Das S. Genetics and epigenetics of diabetes and its complications in India. Hum Genet 2024; 143:1-17. [PMID: 37999799 DOI: 10.1007/s00439-023-02616-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/17/2023] [Indexed: 11/25/2023]
Abstract
Diabetes mellitus (DM) has become a significant health concern with an increasing rate of morbidity and mortality worldwide. India ranks second in the number of diabetes cases in the world. The increasing burden of DM can be explained by genetic predisposition of Indians to type 2 diabetes mellitus (T2DM) coupled with rapid urbanization and socio-economic development in the last 3 decades leading to drastic changes in lifestyle. Environment and lifestyle changes contribute to T2DM development by altering epigenetic processes such as DNA methylation, histone post-translational modifications, and long non-coding RNAs, all of which regulate chromatin structure and gene expression. Although the genetic predisposition of Indians to T2DM is well established, how environmental and genetic factors interact and lead to T2DM is not well understood. In this review, we discuss the prevalence of diabetes and its complications across different states in India and how various risk factors contribute to its pathogenesis. The review also highlights the role of genetic predisposition among the Indian population and epigenetic factors involved in the etiology of diabetes. Lastly, we review current treatments and emphasize the knowledge gap with respect to genetic and epigenetic factors in the Indian context. Further understanding of the genetic and epigenetic determinants will help in risk prediction and prevention as well as therapeutic interventions, which will improve the clinical management of diabetes and associated macro- and micro-vascular complications.
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Affiliation(s)
- Ankita Priyadarshini
- Diabetic Vascular Complications Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, 140306, India
| | - Riya Madan
- Diabetic Vascular Complications Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, 140306, India
| | - Sadhan Das
- Diabetic Vascular Complications Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, 140306, India.
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Sadikan MZ, Abdul Nasir NA. Diabetic retinopathy: emerging concepts of current and potential therapy. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:3395-3406. [PMID: 37401966 DOI: 10.1007/s00210-023-02599-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 06/22/2023] [Indexed: 07/05/2023]
Abstract
Diabetic retinopathy (DR) is one of the leading causes of permanent central blindness worldwide. Despite the complexity and inadequate understanding of DR pathogenesis, many of the underlying pathways are currently partially understood and may offer potential targets for future treatments. Anti-VEGF medications are currently the main medication for this problem. This article provides an overview of the established pharmacological treatments and those that are being developed to cure DR. We firstly reviewed the widely utilized approaches including pan-retinal photocoagulation therapy, anti-VEGF therapy, corticosteroid therapy, and surgical management of DR. Next, we discussed the mechanisms of action and prospective benefits of novel candidate medications. Current management are far from being a perfect treatment for DR, despite mild-term favorable efficiency and safety profiles. Pharmacological research should work toward developing longer-lasting treatments or new drug delivery systems, as well as on identifying new molecular targets in the pathogenetical mechanism for DR. In order to find a treatment that is specifically designed for each patient, it is also necessary to properly characterize patients, taking into account elements like hereditary factors and intraretinal neovascularization stages for effective utilization of drugs. The current and potential approaches for diabetic retinopathy. Image was constructed using Biorender.com.
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Affiliation(s)
- Muhammad Zulfiqah Sadikan
- Department of Pharmacology, Faculty of Medicine, Manipal University College Malaysia (MUCM), Bukit Baru, 75150, Malacca, Malaysia
| | - Nurul Alimah Abdul Nasir
- Department of Medical Education, Faculty of Medicine, Universiti Teknologi MARA, 47000, Sungai Buloh, Selangor, Malaysia.
- Centre for Neuroscience Research (NeuRon), Faculty of Medicine, Universiti Teknologi MARA, 47000, Sungai Buloh, Selangor, Malaysia.
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Ng TK, Chu KO, Wang CC, Pang CP. Green Tea Catechins as Therapeutic Antioxidants for Glaucoma Treatment. Antioxidants (Basel) 2023; 12:1320. [PMID: 37507860 PMCID: PMC10376590 DOI: 10.3390/antiox12071320] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/02/2023] [Accepted: 06/09/2023] [Indexed: 07/30/2023] Open
Abstract
Glaucoma is the leading cause of irreversible blindness and visual impairment, affecting more than 80 million individuals worldwide. Oxidative stress and inflammation-induced neurodegenerative insults to retinal ganglion cells are the main pathogenesis of glaucoma. Retinal ganglion cells, the retinal neurons transmitting the visual signals to the visual cortex in the brain, have very limited regeneration or recovery capacity after damages. Apart from intraocular pressure-lowering treatments, there is still no clinically effective treatment to rescue the degeneration of retinal ganglion cells in glaucoma. Dietary antioxidants are easily accessible and can be applied as supplements assisting in the clinical treatments. Catechins, a chemical family of flavonoids, are the phenolic compounds found in many plants, especially in green tea. The anti-oxidative and anti-inflammatory properties of green tea catechins in vitro and in vivo have been well proven. They could be a potential treatment ameliorating retinal ganglion cell degeneration in glaucoma. In this review, the chemistry, pharmacokinetics, and therapeutic properties of green tea catechins were summarized. Research updates on the biological effects of green tea catechins in cellular and animal experimental glaucoma models were reviewed. In addition, clinical potentials of green tea catechins for glaucoma treatment were also highlighted.
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Affiliation(s)
- Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou 515041, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Kai On Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong
| | - Chi Pui Pang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou 515041, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
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Ansari-Mohseni N, Ghorani-Azam A, Mohajeri SA. Therapeutic effects of herbal medicines in different types of retinopathies: A systematic review. AVICENNA JOURNAL OF PHYTOMEDICINE 2023; 13:118-142. [PMID: 37333471 PMCID: PMC10274316 DOI: 10.22038/ajp.2022.62423.2977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 04/13/2022] [Indexed: 06/20/2023]
Abstract
Objective Retinopathy is an ocular manifestation of systemic diseases such as diabetes and vascular diseases. Herbal drugs have been considered as an effective therapeutic option with minimal side effects for the treatment of retinopathy by reducing the symptoms and improving visual acuity. The purpose of this systematic review was to collect studies on the effectiveness of medicinal plants in the treatment or prevention of retinopathy. Materials and Methods A systematic literature search was performed in PubMed, Scopus, Google Scholar, and other databases in April 2021 using "herbal products" and "Retinopathy" with all their equivalent and similar terms. For this purpose, human clinical trials with the English language were included and articles with subject irrelevancy were excluded from further evaluation. Results Overall, 30 articles with 2324 patients were studied for possible effects of herbal therapy on retinopathy. From 30 included articles, different herbal products had been evaluated. Out of 30 selected articles, 11 articles were for the treatment of age-related macular degeneration (AMD), 14 articles covered patients with diabetic retinopathy, and the other five studies were for other retinal disorders. The outcomes in majority of the studies include changes in visual acuity (VA), fundus performance, best-corrected visual acuity (BCVA), central macular thickness (CMT), focal electroretinogram (fERG), supplements and adjuvant medications appeared to be more beneficial in patients with AMD and diabetic maculopathy. Conclusion Herbal therapy can be considered as a potential candidate in the adjuvant and complementary therapies of retinopathy. However, further studies are required to verify such efficiency.
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Affiliation(s)
- Negin Ansari-Mohseni
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
- Equal first author
| | - Adel Ghorani-Azam
- Department of Forensic Medicine and Toxicology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
- Equal first author
| | - Seyed Ahmad Mohajeri
- Pharmacetical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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Jin Y, Arroo R. The protective effects of flavonoids and carotenoids against diabetic complications-A review of in vivo evidence. Front Nutr 2023; 10:1020950. [PMID: 37032781 PMCID: PMC10080163 DOI: 10.3389/fnut.2023.1020950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 02/24/2023] [Indexed: 04/11/2023] Open
Abstract
Diabetes mellitus is a chronic metabolic disorder caused either by inadequate insulin secretion, impaired insulin function, or both. Uncontrolled diabetes is characterized by hyperglycemia which over time leads to fatal damage to both macro-and microvascular systems, causing complications such as cardiovascular diseases, retinopathy and nephropathy. Diabetes management is conventionally delivered through modifications of diet and lifestyle and pharmacological treatment, using antidiabetic drugs, and ultimately insulin injections. However, the side effects and financial cost of medications often reduce patient compliance to treatment, negatively affecting their health outcomes. Natural phytochemicals from edible plants such as fruits and vegetables (F&V) and medicinal herbs have drawn a growing interest as potential therapeutic agents for treating diabetes and preventing the onset and progression of diabetic complications. Flavonoids, the most abundant polyphenols in the human diet, have shown antidiabetic effects in numerous in vitro and preclinical studies. The underlying mechanisms have been linked to their antioxidant, anti-inflammatory and immunomodulatory activities. Carotenoids, another major group of dietary phytochemicals, have also shown antidiabetic potential in recent in vitro and in vivo experimental models, possibly through a mechanism of action similar to that of flavonoids. However, scientific evidence on the efficacy of these phytochemicals in treating diabetes or preventing the onset and progression of its complications in clinical settings is scarce, which delays the translation of animal study evidence to human applications and also limits the knowledge on their modes of actions in diabetes management. This review is aimed to highlight the potential roles of flavonoids and carotenoids in preventing or ameliorating diabetes-related complications based on in vivo study evidence, i.e., an array of preclinical animal studies and human intervention trials. The current general consensus of the underlying mechanisms of action exerted by both groups of phytochemicals is that their anti-inflammatory action is key. However, other potential mechanisms of action are considered. In total, 50 in vivo studies were selected for a review after a comprehensive database search via PubMed and ScienceDirect from January 2002 to August 2022. The key words used for analysis are type-2 diabetes (T2DM), diabetic complications, flavonoids, carotenoids, antioxidant, anti-inflammatory, mechanisms of prevention and amelioration, animal studies and human interventions.
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Affiliation(s)
- Yannan Jin
- Leicester School of Allied Health Sciences, Faculty of Health & Life Sciences, De Montfort University, Leicester, United Kingdom
- *Correspondence: Yannan Jin,
| | - Randolph Arroo
- Leicester School of Pharmacy, Faculty of Health & Life Sciences, De Montfort University, Leicester, United Kingdom
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Kang Q, Dai H, Jiang S, Yu L. Advanced glycation end products in diabetic retinopathy and phytochemical therapy. Front Nutr 2022; 9:1037186. [PMID: 36466410 PMCID: PMC9716030 DOI: 10.3389/fnut.2022.1037186] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 10/31/2022] [Indexed: 10/12/2023] Open
Abstract
Advanced glycation end products (AGEs) are generated by the nonenzymatic glycation of proteins or lipids. Diabetic retinopathy (DR) is one common complication in patients with diabetes. The accumulation of AGEs in retinal cells is strongly associated with the development of DR. AGEs can induce the breakdown of redox balance and then cause oxidative stress in retinal cells, exerting cytopathic effects in the progression of DR. The interaction between AGEs and the receptor for AGE (RAGE) is involved in multiple cellular pathological alterations in the retina. This review is to elucidate the pathogenetic roles of AGEs in the progression of DR, including metabolic abnormalities, lipid peroxidation, structural and functional alterations, and neurodegeneration. In addition, disorders associated with AGEs can be used as potential therapeutic targets to explore effective and safe treatments for DR. In this review, we have also introduced antioxidant phytochemicals as potential therapeutic strategies for the treatment of DR.
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Affiliation(s)
- Qingzheng Kang
- Department of Hematology and Oncology, International Cancer Center, Shenzhen Key Laboratory, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
| | - Haiyu Dai
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Suwei Jiang
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Li Yu
- Department of Hematology and Oncology, International Cancer Center, Shenzhen Key Laboratory, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
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Milluzzo A, Barchitta M, Maugeri A, Magnano San Lio R, Favara G, Mazzone MG, Sciacca L, Agodi A. Do Nutrients and Nutraceuticals Play a Role in Diabetic Retinopathy? A Systematic Review. Nutrients 2022; 14:4430. [PMID: 36297113 PMCID: PMC9612209 DOI: 10.3390/nu14204430] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/13/2022] [Accepted: 10/18/2022] [Indexed: 11/07/2022] Open
Abstract
Diabetic retinopathy (DR) is a multifactorial neuro-microvascular disease, whose prevalence ranges from 25% to 60% of subjects affected by diabetes mellitus, representing the main cause of legal blindness in adults of industrialized countries. The treatment of advanced stage of DR is based on invasive and expensive therapies, while few strategies are available for the early stage or prevention. The mechanisms underlying DR involve a complex interplay between the detrimental effects of hyperglycemia, dyslipidemia, hypoxia, and oxidative stress, providing several pathways potentially targeted by nutrients and nutraceuticals. In this study, we conducted a systematic review of observational and interventional studies, evaluating the effect of nutrients and/or nutraceuticals on the risk of DR and their potential use for the treatment of patients with DR. The analysis of the 41 included studies (27 observational and 14 interventional studies) suggests a promising preventive role of some nutrients, in particular for vitamins B (i.e., B1 and B12), D, and E. However, further investigations are necessary to clarify the potential clinical application of nutraceuticals in the prevention and treatment of DR.
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Affiliation(s)
- Agostino Milluzzo
- Department of Clinical and Experimental Medicine, Endocrinology Section, University of Catania, 95122 Catania, Italy
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
| | - Martina Barchitta
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
| | - Andrea Maugeri
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
| | - Roberta Magnano San Lio
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
| | - Giuliana Favara
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
| | - Maria Grazia Mazzone
- Research, Preclinical Development and Patents, SIFI S.p.A., Lavinaio-Aci S. Antonio, 95025 Catania, Italy
| | - Laura Sciacca
- Department of Clinical and Experimental Medicine, Endocrinology Section, University of Catania, 95122 Catania, Italy
| | - Antonella Agodi
- Department of Medical and Surgical Sciences and Advanced Technologies “GF Ingrassia”, University of Catania, Via S. Sofia 87, 95123 Catania, Italy
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Combined drug triads for synergic neuroprotection in retinal degeneration. Biomed Pharmacother 2022; 149:112911. [DOI: 10.1016/j.biopha.2022.112911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 11/23/2022] Open
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Canovai A, Amato R, Melecchi A, Dal Monte M, Rusciano D, Bagnoli P, Cammalleri M. Preventive Efficacy of an Antioxidant Compound on Blood Retinal Barrier Breakdown and Visual Dysfunction in Streptozotocin-Induced Diabetic Rats. Front Pharmacol 2022; 12:811818. [PMID: 35046830 PMCID: PMC8762314 DOI: 10.3389/fphar.2021.811818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/06/2021] [Indexed: 12/13/2022] Open
Abstract
In diabetic retinopathy (DR), high blood glucose drives chronic oxidative stress and inflammation that trigger alterations of the neurovascular balance finally resulting in vascular abnormalities and retinal cell death, which converge towards altered electroretinogram (ERG). In the last years, a growing body of preclinical evidence has suggested that nutrients with anti-inflammatory/antioxidant properties can be able to hamper DR progression since its very early stages. In the present study, we used a streptozotocin-induced rat model of DR, which mimics most aspects of the early stages of human DR, to test the preventive efficacy of a novel compound containing cyanidin-3-glucoside (C3G), verbascoside and zinc as nutrients with antioxidant and anti-inflammatory properties. Western blot, immunofluorescence and electroretinographic analyses demonstrated a dose-dependent inhibition of oxidative stress- and inflammation-related mechanisms, with a significant counterpart in preventing molecular mechanisms leading to DR-associated vasculopathy and its related retinal damage. Preventive efficacy of the compound on dysfunctional a- and b-waves was also demonstrated by electroretinography. The present demonstration that natural compounds, possibly as a consequence of vascular rescue following ameliorated oxidative stress and inflammation, may prevent the apoptotic cascade leading to ERG dysfunction, adds further relevance to the potential application of antioxidants as a preventive therapy to counteract DR progression.
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Affiliation(s)
| | - Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | | | - Paola Bagnoli
- Department of Biology, University of Pisa, Pisa, Italy
| | - Maurizio Cammalleri
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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Piñas García P, Hernández Martínez FJ, Aznárez López N, Castillón Torre L, Tena Sempere ME. Supplementation with a Highly Concentrated Docosahexaenoic Acid (DHA) in Non-Proliferative Diabetic Retinopathy: A 2-Year Randomized Double-Blind Placebo-Controlled Study. Antioxidants (Basel) 2022; 11:antiox11010116. [PMID: 35052620 PMCID: PMC8772895 DOI: 10.3390/antiox11010116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/28/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
We assessed the effect of a 2-year supplementation with a highly concentrated docosahexaenoic acid (DHA) product with antioxidant activity on non-proliferative diabetic retinopathy (NPDR) in a randomized double-blind placebo-controlled study. A total of 170 patients with diabetes were randomly assigned to the DHA group (n = 83) or the placebo group (n = 87). NPDR was diagnosed using non-contact slit lamp biomicroscopy examination, and classified into mild, moderate, and severe stages. Patients in the DHA group received a high rich DHA triglyceride (1050 mg/day) nutritional supplement, and those in the placebo group received olive oil capsules. The percentages of mild NPDR increased from 61.7% at baseline to 75.7% at the end of the study in the DHA group, and from 61.9% to 73.1% in the placebo group. Moderate NPDR stages decreased from 35.1% at baseline to 18.7% at the end of the study in the DHA group, and from 36.8% to 26.0% in the placebo group. In the DHA group, there were five eyes with severe NPDR at baseline, which increased to one more at the end of the study. In the placebo group, of two eyes with severe NPDR at baseline, one eye remained at the end of the study. Changes in visual acuity were not found. There were improvements in the serum levels of HbA1c in both groups, but significant differences between the DHA and the placebo groups were not found. In this study, the use of a DHA triglyceride nutraceutical supplement for 2 years did not appear to influence the slowing of the progression of NPDR.
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Tang C, Liu Y, Liu S, Yang C, Chen L, Tang F, Wang F, Zhan L, Deng H, Zhou W, Lin Y, Yuan X. Curcumin and Its Analogs as Potential Epigenetic Modulators: Prevention of Diabetes and Its Complications. Pharmacology 2021; 107:1-13. [PMID: 34915505 DOI: 10.1159/000520311] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND The pathobiology of diabetes and associated complications has been widely researched in various countries, but effective prevention and treatment methods are still insufficient. Diabetes is a metabolic disorder of carbohydrates, fats, and proteins caused by an absence of insulin or insulin resistance, which mediates an increase of oxidative stress, release of inflammatory factors, and macro- or micro-circulation dysfunctions, ultimately developing into diverse complications. SUMMARY In the last decade through pathogenesis research, epigenetics has been found to affect metabolic diseases. Particularly, DNA methylation, histone acetylation, and miRNAs promote or inhibit diabetes and complications by regulating the expression of related factors. Curcumin has a wide range of beneficial pharmacological activities, including anti-inflammatory, anti-oxidation, anticancer, anti-diabetes, anti-rheumatism, and increased immunity. Key Messages: In this review, we discuss the effects of curcumin and analogs on diabetes and associated complications through epigenetics, and we summarize the preclinical and clinical researches for curcumin and its analogs in terms of management of diabetes and associated complications, which may provide an insight into the development of targeted therapy of endocrine diseases.
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Affiliation(s)
- Chunyin Tang
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Yantao Liu
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Shilin Liu
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Chunsong Yang
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Li Chen
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Fengru Tang
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Fang Wang
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Lin Zhan
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Hong Deng
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Wei Zhou
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Yunzhu Lin
- Department of Pharmacy, Evidence-based Pharmacy Center, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, China
| | - Xiaohuan Yuan
- Heilongjiang Key Laboratory of Anti-Fibrosis Biotherapy, Mudanjiang Medical University, Mudanjiang, China
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Richer S, Novil S, Gullett T, Dervishi A, Nassiri S, Duong C, Davis R, Davey PG. Night Vision and Carotenoids (NVC): A Randomized Placebo Controlled Clinical Trial on Effects of Carotenoid Supplementation on Night Vision in Older Adults. Nutrients 2021; 13:3191. [PMID: 34579067 PMCID: PMC8471486 DOI: 10.3390/nu13093191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 12/22/2022] Open
Abstract
Twilight and low luminance levels are visually challenging environments for the elderly, especially when driving at night. Carotenoid rich diets are known to increase macular pigment optical density (MPOD), which in turn leads to an improvement in visual function. It is not known whether augmenting MPOD can lead to a decrease in vision related night driving difficulties. Additionally, it is unknown if carotenoid supplementation provides additional measurable benefits to one's useful field of view (UFOV) along with a decreased composite crash risk score. The aim of the study was to evaluate changes in night vision function and UFOV in individuals that took carotenoid vitamin supplements for a six-month period compared to a placebo group. METHODS A prospective, randomized, double-blind, six-month trial of a 14 mg zeaxanthin/7 mg lutein-based supplement was carried out. Participants were randomized into active or placebo group (approx 2:1). RESULTS n = 33 participants (26 males/7 females) participated with 93% capsule intake compliance in the supplemented group (n = 24) and placebo group (n = 9). MPOD (mean/standard error SE) in the active group increased in the Right eye from 0.35 density units (du)/0.04 SE to 0.41 du/0.05 SE; p < 0.001 and in the Left eye from 0.35 du/0.05 SE to 0.37 du, p > 0.05). The supplemented group showed significant improvements in contrast sensitivity with glare in both eyes with improvements in LogMAR scores of 0.147 and 0.149, respectively (p = 0.02 and 0.01, respectively), monocularly tested glare recovery time improved 2.76 and 2.54 s, respectively, (p = 0.008 and p = 0.02), and we also noted a decreased preferred luminance required to complete visual tasks (p = 0.02 and 0.03). Improvements in UFOV scores of divided attention (p < 0.001) and improved composite crash risk score (p = 0.004) were seen in the supplemented group. The placebo group remained unchanged. CONCLUSIONS The NVC demonstrates that augmenting MPOD in individuals with difficulty in night vision showed measurable benefits in numerous visual functions that are important for night vision driving in this small sample RCT. Additionally, we observed an improvement in UFOV divided attention test scores and decreased composite risk scores.
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Affiliation(s)
- Stuart Richer
- Captain James A Lovell Fed Health Care Facility, North Chicago, IL 60064, USA;
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; (T.G.); (A.D.); (S.N.); (C.D.)
| | - Steven Novil
- Captain James A Lovell Fed Health Care Facility, North Chicago, IL 60064, USA;
| | - Taylor Gullett
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; (T.G.); (A.D.); (S.N.); (C.D.)
| | - Avni Dervishi
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; (T.G.); (A.D.); (S.N.); (C.D.)
| | - Sherwin Nassiri
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; (T.G.); (A.D.); (S.N.); (C.D.)
| | - Co Duong
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; (T.G.); (A.D.); (S.N.); (C.D.)
| | - Robert Davis
- Davis Eye Care Associates, Oak Lawn, IL 60453, USA;
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15
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Kumar A, Harsha C, Parama D, Girisa S, Daimary UD, Mao X, Kunnumakkara AB. Current clinical developments in curcumin-based therapeutics for cancer and chronic diseases. Phytother Res 2021; 35:6768-6801. [PMID: 34498308 DOI: 10.1002/ptr.7264] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 06/16/2021] [Accepted: 08/14/2021] [Indexed: 12/19/2022]
Abstract
The last decade has seen an unprecedented rise in the prevalence of chronic diseases worldwide. Different mono-targeted approaches have been devised to treat these multigenic diseases, still most of them suffer from limited success due to the off-target debilitating side effects and their inability to target multiple pathways. Hence a safe, efficacious, and multi-targeted approach is the need for the hour to circumvent these challenging chronic diseases. Curcumin, a natural compound extracted from the rhizomes of Curcuma longa, has been under intense scrutiny for its wide medicinal and biological properties. Curcumin is known to manifest antibacterial, antiinflammatory, antioxidant, antifungal, antineoplastic, antifungal, and proapoptotic effects. A plethora of literature has already established the immense promise of curcuminoids in the treatment and clinical management of various chronic diseases like cancer, cardiovascular, metabolic, neurological, inflammatory, and infectious diseases. To date, more than 230 clinical trials have opened investigations to understand the pharmacological aspects of curcumin in human systems. Still, further randomized clinical studies in different ethnic populations warrant its transition to a marketed drug. This review summarizes the results from different clinical trials of curcumin-based therapeutics in the prevention and treatment of various chronic diseases.
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Affiliation(s)
- Aviral Kumar
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
| | - Choudhary Harsha
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
| | - Dey Parama
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
| | - Sosmitha Girisa
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
| | - Uzini Devi Daimary
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
| | - Xinliang Mao
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ajaikumar B Kunnumakkara
- Cancer Biology Laboratory and DBT-AIST International Center for Translational and Environmental Research (DAICENTER), Department of Biosciences and Bioengineering, Indian Institute of Technology (IIT) Guwahati, Guwahati, India
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Dammak A, Huete-Toral F, Carpena-Torres C, Martin-Gil A, Pastrana C, Carracedo G. From Oxidative Stress to Inflammation in the Posterior Ocular Diseases: Diagnosis and Treatment. Pharmaceutics 2021; 13:1376. [PMID: 34575451 PMCID: PMC8467715 DOI: 10.3390/pharmaceutics13091376] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 12/17/2022] Open
Abstract
Most irreversible blindness observed with glaucoma and retina-related ocular diseases, including age-related macular degeneration and diabetic retinopathy, have their origin in the posterior segment of the eye, making their physiopathology both complex and interconnected. In addition to the age factor, these diseases share the same mechanism disorder based essentially on oxidative stress. In this context, the imbalance between the production of reactive oxygen species (ROS) mainly by mitochondria and their elimination by protective mechanisms leads to chronic inflammation. Oxidative stress and inflammation share a close pathophysiological process, appearing simultaneously and suggesting a relationship between both mechanisms. The biochemical end point of these two biological alarming systems is the release of different biomarkers that can be used in the diagnosis. Furthermore, oxidative stress, initiating in the vulnerable tissue of the posterior segment, is closely related to mitochondrial dysfunction, apoptosis, autophagy dysfunction, and inflammation, which are involved in each disease progression. In this review, we have analyzed (1) the oxidative stress and inflammatory processes in the back of the eye, (2) the importance of biomarkers, detected in systemic or ocular fluids, for the diagnosis of eye diseases based on recent studies, and (3) the treatment of posterior ocular diseases, based on long-term clinical studies.
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Affiliation(s)
- Azza Dammak
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
| | - Fernando Huete-Toral
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
| | - Carlos Carpena-Torres
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
| | - Alba Martin-Gil
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
| | - Cristina Pastrana
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
| | - Gonzalo Carracedo
- Ocupharm Group Research, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain; (A.D.); (F.H.-T.); (C.C.-T.); (A.M.-G.); (C.P.)
- Department of Optometry and Vsiion, Faculty of Optic and Optometry, University Complutense of Madrid, C/Arcos del Jalon 118, 28037 Madrid, Spain
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Lem DW, Davey PG, Gierhart DL, Rosen RB. A Systematic Review of Carotenoids in the Management of Age-Related Macular Degeneration. Antioxidants (Basel) 2021; 10:1255. [PMID: 34439503 PMCID: PMC8389280 DOI: 10.3390/antiox10081255] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 01/14/2023] Open
Abstract
Age-related macular degeneration (AMD) remains a leading cause of modifiable vision loss in older adults. Chronic oxidative injury and compromised antioxidant defenses represent essential drivers in the development of retinal neurodegeneration. Overwhelming free radical species formation results in mitochondrial dysfunction, as well as cellular and metabolic imbalance, which becomes exacerbated with increasing age. Thus, the depletion of systemic antioxidant capacity further proliferates oxidative stress in AMD-affected eyes, resulting in loss of photoreceptors, neuroinflammation, and ultimately atrophy within the retinal tissue. The aim of this systematic review is to examine the neuroprotective potential of the xanthophyll carotenoids lutein, zeaxanthin, and meso-zeaxanthin on retinal neurodegeneration for the purpose of adjunctive nutraceutical strategy in the management of AMD. A comprehensive literature review was performed to retrieve 55 eligible publications, using four database searches from PubMed, Embase, Cochrane Library, and the Web of Science. Epidemiology studies indicated an enhanced risk reduction against late AMD with greater dietary consumption of carotenoids, meanwhile greater concentrations in macular pigment demonstrated significant improvements in visual function among AMD patients. Collectively, evidence strongly suggests that carotenoid vitamin therapies offer remarkable synergic protection in the neurosensory retina, with the potential to serve as adjunctive nutraceutical therapy in the management of established AMD, albeit these benefits may vary among different stages of disease.
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Affiliation(s)
- Drake W. Lem
- College of Optometry, Western University of Health Sciences, Pomona, CA 91766, USA;
| | | | | | - Richard B. Rosen
- Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
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18
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Macular Pigment Reflectometry: Developing Clinical Protocols, Comparison with Heterochromatic Flicker Photometry and Individual Carotenoid Levels. Nutrients 2021; 13:nu13082553. [PMID: 34444721 PMCID: PMC8399813 DOI: 10.3390/nu13082553] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 12/26/2022] Open
Abstract
The study was designed to: (1) Analyze and create protocols of obtaining measurements using the Macular Pigment Reflectometry (MPR). (2) To assess the agreement of MPOD measurements obtained using the heterochromatic flicker photometry (MPS II) and MPR. (3) To obtain the lutein and zeaxanthin optical density obtained using the MPR in the central one-degree of the macula. The measurements were performed using the MPR and heterochromatic flicker photometry. The MPR measurements were performed twice without pupillary dilation and twice following pupillary dilation. The MPR measurements were performed for a 40-s period and the spectrometer signal was parsed at different time points: 10–20, 10–30, 10–40, 20–30, 20–40, and 30–40 s. The MPR analyzes the high-resolution spectrometer signal and calculates MPOD, lutein optical density and zeaxanthin optical density automatically. The MPR-MPOD data was compared with MPPS II-MPOD results. The MPR-MPOD values are highly correlated and in good agreement with the MPS II-MPOD. Of the various parsing of the data, the data 10–30 interval was the best at obtaining the MPOD, lutein, and zeaxanthin values (8–12% coefficient of repeatability). The lutein to zeaxanthin ratio in the central one-degree of the macula was 1:2.40. Dilation was not needed to obtain the MPOD values but provided better repeatability of lutein and zeaxanthin optical density. MPR generates MPOD measurements that is in good agreement with MPS II. The device can produce lutein and zeaxanthin optical density which is not available from other clinical devices.
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Lem DW, Gierhart DL, Davey PG. A Systematic Review of Carotenoids in the Management of Diabetic Retinopathy. Nutrients 2021; 13:2441. [PMID: 34371951 PMCID: PMC8308772 DOI: 10.3390/nu13072441] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 12/21/2022] Open
Abstract
Diabetic retinopathy, which was primarily regarded as a microvascular disease, is the leading cause of irreversible blindness worldwide. With obesity at epidemic proportions, diabetes-related ocular problems are exponentially increasing in the developed world. Oxidative stress due to hyperglycemic states and its associated inflammation is one of the pathological mechanisms which leads to depletion of endogenous antioxidants in retina in a diabetic patient. This contributes to a cascade of events that finally leads to retinal neurodegeneration and irreversible vision loss. The xanthophylls lutein and zeaxanthin are known to promote retinal health, improve visual function in retinal diseases such as age-related macular degeneration that has oxidative damage central in its etiopathogenesis. Thus, it can be hypothesized that dietary supplements with xanthophylls that are potent antioxidants may regenerate the compromised antioxidant capacity as a consequence of the diabetic state, therefore ultimately promoting retinal health and visual improvement. We performed a comprehensive literature review of the National Library of Medicine and Web of Science databases, resulting in 341 publications meeting search criteria, of which, 18 were found eligible for inclusion in this review. Lutein and zeaxanthin demonstrated significant protection against capillary cell degeneration and hyperglycemia-induced changes in retinal vasculature. Observational studies indicate that depletion of xanthophyll carotenoids in the macula may represent a novel feature of DR, specifically in patients with type 2 or poorly managed type 1 diabetes. Meanwhile, early interventional trials with dietary carotenoid supplementation show promise in improving their levels in serum and macular pigments concomitant with benefits in visual performance. These findings provide a strong molecular basis and a line of evidence that suggests carotenoid vitamin therapy may offer enhanced neuroprotective effects with therapeutic potential to function as an adjunct nutraceutical strategy for management of diabetic retinopathy.
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Affiliation(s)
- Drake W. Lem
- College of Optometry, Western University of Health Sciences, 309 E Second St, Pomona, CA 91766, USA;
| | | | - Pinakin Gunvant Davey
- College of Optometry, Western University of Health Sciences, 309 E Second St, Pomona, CA 91766, USA;
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20
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Lem DW, Gierhart DL, Davey PG. Carotenoids in the Management of Glaucoma: A Systematic Review of the Evidence. Nutrients 2021; 13:nu13061949. [PMID: 34204051 PMCID: PMC8228567 DOI: 10.3390/nu13061949] [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: 05/10/2021] [Revised: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 12/23/2022] Open
Abstract
Primary open-angle glaucoma (POAG) remains a leading cause of irreversible blindness globally. Recent evidence further substantiates sustained oxidative stress, and compromised antioxidant defenses are key drivers in the onset of glaucomatous neurodegeneration. Overwhelming oxidative injury is likely attributed to compounding mitochondrial dysfunction that worsens with age-related processes, causing aberrant formation of free radical species. Thus, a compromised systemic antioxidant capacity exacerbates further oxidative insult in glaucoma, leading to apoptosis, neuroinflammation, and subsequent tissue injury. The purpose of this systematic review is to investigate the neuroprotective benefits of the macular carotenoids lutein, zeaxanthin, and meso-zeaxanthin on glaucomatous neurodegeneration for the purpose of adjunctive nutraceutical treatment in glaucoma. A comprehensive literature search was conducted in three databases (PubMed, Cochrane Library, and Web of Science) and 20 records were identified for screening. Lutein demonstrated enhanced neuroprotection on retinal ganglion cell survival and preserved synaptic activity. In clinical studies, a protective trend was seen with greater dietary consumption of carotenoids and risk of glaucoma, while greater carotenoid levels in macular pigment were largely associated with improved visual performance in glaucomatous eyes. The data suggest that carotenoid vitamin therapy exerts synergic neuroprotective benefits and has the capacity to serve adjunctive therapy in the management of glaucoma.
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Affiliation(s)
- Drake W. Lem
- College of Optometry, Western University of Health Sciences, 309 E Second St, Pomona, CA 91766, USA;
| | | | - Pinakin Gunvant Davey
- College of Optometry, Western University of Health Sciences, 309 E Second St, Pomona, CA 91766, USA;
- Correspondence: ; Tel.: +1-909-469-8473
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21
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Searching for the Antioxidant, Anti-Inflammatory, and Neuroprotective Potential of Natural Food and Nutritional Supplements for Ocular Health in the Mediterranean Population. Foods 2021; 10:foods10061231. [PMID: 34071459 PMCID: PMC8229954 DOI: 10.3390/foods10061231] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/14/2022] Open
Abstract
Adherence to a healthy diet offers a valuable intervention to compete against the increasing cases of ocular diseases worldwide, such as dry eye disorders, myopia progression, cataracts, glaucoma, diabetic retinopathy, or age macular degeneration. Certain amounts of micronutrients must be daily provided for proper functioning of the visual system, such as vitamins, carotenoids, trace metals and omega-3 fatty acids. Among natural foods, the following have to be considered for boosting eye/vision health: fish, meat, eggs, nuts, legumes, citrus fruits, nuts, leafy green vegetables, orange-colored fruits/vegetables, olives-olive oil, and dairy products. Nutritional supplements have received much attention as potential tools for managing chronic-degenerative ocular diseases. A systematic search of PubMed, Web of Science, hand-searched publications and historical archives were performed by the professionals involved in this study, to include peer-reviewed articles in which natural food, nutrient content, and its potential relationship with ocular health. Five ophthalmologists and two researchers collected the characteristics, quality and suitability of the above studies. Finally, 177 publications from 1983 to 2021 were enclosed, mainly related to natural food, Mediterranean diet (MedDiet) and nutraceutic supplementation. For the first time, original studies with broccoli and tigernut (chufa de Valencia) regarding the ocular surface dysfunction, macular degeneration, diabetic retinopathy and glaucoma were enclosed. These can add value to the diet, counteract nutritional defects, and help in the early stages, as well as in the course of ophthalmic pathologies. The main purpose of this review, enclosed in the Special Issue "Health Benefits and Nutritional Quality of Fruits, Nuts and Vegetables," is to identify directions for further research on the role of diet and nutrition in the eyes and vision, and the potential antioxidant, anti-inflammatory and neuroprotective effects of natural food (broccoli, saffron, tigernuts and walnuts), the Mediterranean Diet, and nutraceutic supplements that may supply a promising and highly affordable scenario for patients at risk of vision loss. This review work was designed and carried out by a multidisciplinary group involved in ophthalmology and ophthalmic research and especially in nutritional ophthalmology.
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22
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Role of Oral Antioxidant Supplementation in the Current Management of Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22084020. [PMID: 33924714 PMCID: PMC8069935 DOI: 10.3390/ijms22084020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 12/13/2022] Open
Abstract
Oxidative stress has been postulated as an underlying pathophysiologic mechanism of diabetic retinopathy (DR), the main cause of avoidable blindness in working-aged people. This review addressed the current daily clinical practice of DR and the role of antioxidants in this practice. A systematic review of the studies on antioxidant supplementation in DR patients was presented. Fifteen studies accomplished the inclusion criteria. The analysis of these studies concluded that antioxidant supplementation has a IIB level of recommendation in adult Type 1 and Type 2 diabetes mellitus subjects without retinopathy or mild-to-moderate nonproliferative DR without diabetic macular oedema as a complementary therapy together with standard medical care.
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Matuszewski W, Baranowska-Jurkun A, Stefanowicz-Rutkowska MM, Gontarz-Nowak K, Gątarska E, Bandurska-Stankiewicz E. The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review. J Clin Med 2021; 10:705. [PMID: 33670143 PMCID: PMC7916896 DOI: 10.3390/jcm10040705] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes. AIM The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR. MATERIAL AND METHODS An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR. RESULTS A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period. CONCLUSIONS It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.
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Affiliation(s)
- Wojciech Matuszewski
- Department of Internal Medicine, Endocrinology, Diabetology and Internal Medicine Clinic, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland; (A.B.-J.); (M.M.S.-R.); (K.G.-N.); (E.B.-S.)
| | - Angelika Baranowska-Jurkun
- Department of Internal Medicine, Endocrinology, Diabetology and Internal Medicine Clinic, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland; (A.B.-J.); (M.M.S.-R.); (K.G.-N.); (E.B.-S.)
| | - Magdalena Maria Stefanowicz-Rutkowska
- Department of Internal Medicine, Endocrinology, Diabetology and Internal Medicine Clinic, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland; (A.B.-J.); (M.M.S.-R.); (K.G.-N.); (E.B.-S.)
| | - Katarzyna Gontarz-Nowak
- Department of Internal Medicine, Endocrinology, Diabetology and Internal Medicine Clinic, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland; (A.B.-J.); (M.M.S.-R.); (K.G.-N.); (E.B.-S.)
| | - Ewa Gątarska
- Nephrology, Transplantology and Internal Medicine Clinic, Pomeranian Medicine University in Szczecin, 70-204 Szczecin, Poland;
| | - Elżbieta Bandurska-Stankiewicz
- Department of Internal Medicine, Endocrinology, Diabetology and Internal Medicine Clinic, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn, Poland; (A.B.-J.); (M.M.S.-R.); (K.G.-N.); (E.B.-S.)
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Carrizzo A, Izzo C, Forte M, Sommella E, Di Pietro P, Venturini E, Ciccarelli M, Galasso G, Rubattu S, Campiglia P, Sciarretta S, Frati G, Vecchione C. A Novel Promising Frontier for Human Health: The Beneficial Effects of Nutraceuticals in Cardiovascular Diseases. Int J Mol Sci 2020; 21:ijms21228706. [PMID: 33218062 PMCID: PMC7698807 DOI: 10.3390/ijms21228706] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, myocardial infarction, and diabetes are a significant public health problem worldwide. Although several novel pharmacological treatments to reduce the progression of CVDs have been discovered during the last 20 years, the better way to contain the onset of CVDs remains prevention. In this regard, nutraceuticals seem to own a great potential in maintaining human health, exerting important protective cardiovascular effects. In the last years, there has been increased focus on identifying natural compounds with cardiovascular health-promoting effects and also to characterize the molecular mechanisms involved. Although many review articles have focused on the individual natural compound impact on cardiovascular diseases, the aim of this manuscript was to examine the role of the most studied nutraceuticals, such as resveratrol, cocoa, quercetin, curcumin, brassica, berberine and Spirulina platensis, on different CVDs.
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Affiliation(s)
- Albino Carrizzo
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Carmine Izzo
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Maurizio Forte
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
| | - Eduardo Sommella
- Department of Pharmacy, University of Salerno, 84084 Fisciano, Italy;
| | - Paola Di Pietro
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Eleonora Venturini
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
| | - Michele Ciccarelli
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Gennaro Galasso
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Speranza Rubattu
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Ospedale S.Andrea, Via di Grottarossa 1035, 00189 Rome, Italy
| | - Petro Campiglia
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
| | - Sebastiano Sciarretta
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica 74, 04100 Latina, Italy
| | - Giacomo Frati
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica 74, 04100 Latina, Italy
| | - Carmine Vecchione
- Department of Angio-Cardio-Neurology, IRCCS Neuromed, 86077 Pozzilli, Italy; (A.C.); (M.F.); (E.V.); (S.R.); (S.S.); (G.F.)
- Department of Medicine and Surgery, University of Salerno, 84081 Baronissi, Italy; (C.I.); (P.D.P.); (M.C.); (G.G.); (P.C.)
- Correspondence:
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Kang Q, Yang C. Oxidative stress and diabetic retinopathy: Molecular mechanisms, pathogenetic role and therapeutic implications. Redox Biol 2020; 37:101799. [PMID: 33248932 PMCID: PMC7767789 DOI: 10.1016/j.redox.2020.101799] [Citation(s) in RCA: 352] [Impact Index Per Article: 88.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/29/2020] [Accepted: 11/10/2020] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress, a cytopathic outcome of excessive generation of ROS and the repression of antioxidant defense system for ROS elimination, is involved in the pathogenesis of multiple diseases, including diabetes and its complications. Retinopathy, a microvascular complication of diabetes, is the primary cause of acquired blindness in diabetic patients. Oxidative stress has been verified as one critical contributor to the pathogenesis of diabetic retinopathy. Oxidative stress can both contribute to and result from the metabolic abnormalities induced by hyperglycemia, mainly including the increased flux of the polyol pathway and hexosamine pathway, the hyper-activation of protein kinase C (PKC) isoforms, and the accumulation of advanced glycation end products (AGEs). Moreover, the repression of the antioxidant defense system by hyperglycemia-mediated epigenetic modification also leads to the imbalance between the scavenging and production of ROS. Excessive accumulation of ROS induces mitochondrial damage, cellular apoptosis, inflammation, lipid peroxidation, and structural and functional alterations in retina. Therefore, it is important to understand and elucidate the oxidative stress-related mechanisms underlying the progress of diabetic retinopathy. In addition, the abnormalities correlated with oxidative stress provide multiple potential therapeutic targets to develop safe and effective treatments for diabetic retinopathy. Here, we also summarized the main antioxidant therapeutic strategies to control this disease. Oxidative stress can both contribute to and result from hyperglycemia-induced metabolic abnormalities in retina. Genes important in regulation of ROS are epigenetically modified, increasing ROS accumulation in retina. Oxidative stress is closely associated with the pathological changes in the progress of diabetic retinopathy. Antioxidants ameliorate retinopathy through targeting multiple steps of oxidative stress.
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Affiliation(s)
- Qingzheng Kang
- Institute for Advanced Study, Shenzhen University, Nanshan District, Shenzhen, 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Chunxue Yang
- Department of Pathology, The University of Hong Kong, Hong Kong SAR, 999077, China.
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ValdezGuerrero AS, Quintana-Pérez JC, Arellano-Mendoza MG, Castañeda-Ibarra FJ, Tamay-Cach F, Alemán-González-Duhart D. Diabetic Retinopathy: Important Biochemical Alterations and the Main Treatment Strategies. Can J Diabetes 2020; 45:504-511. [PMID: 33341391 DOI: 10.1016/j.jcjd.2020.10.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/08/2020] [Accepted: 10/17/2020] [Indexed: 02/07/2023]
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by impaired glucose homeostasis, insulin resistance and hyperglycemia. Among its serious multisystemic complications is diabetic retinopathy (DR), which develops slowly and often insidiously. This disorder-the most common cause of vision loss in working-age adults-is characterized by functional and morphological changes in the retina. It results from the exacerbation of ischemic and inflammatory conditions prompted by alterations in the blood vessels, such as the development of leukostasis, thickening of the basement membrane, retinal neovascularization and fibrovascular tissue formation at the vitreoretinal interface. The pathogenic alterations are usually triggered at the biochemical level, involving a greater activity in 4 pathways: the polyol pathway, the hexosamine pathway, the formation of advanced glycation end-products and the activation of protein kinase C isoforms. When acting together, these pathways give rise to increased levels of reactive oxygen species and decreased levels of endogenous antioxidant agents, thus generating oxidative stress. All current therapies are aimed at the later stages of DR, and their application implies side effects. One possible strategy for preventing the complications of DM is to counteract the elevated superoxide production stemming from a high level of blood glucose. Accordingly, some treatments are under study for their capacity to reduce vascular leakage and avoid retinal ischemia, retinal neovascularization and macular edema. The present review summarizes the biochemical aspects of DR and the main approaches for treating it.
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Affiliation(s)
- Amaranta Sarai ValdezGuerrero
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Julio César Quintana-Pérez
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Mónica Griselda Arellano-Mendoza
- Research Laboratory in Chronic Degenerative Diseases, Section of Postgraduate Studies and Research, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Francisco Javier Castañeda-Ibarra
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico
| | - Feliciano Tamay-Cach
- Laboratory for Research in Applied Biochemistry, Section of Postgraduate Studies and Research, Department of Basic Disciplinary Training, Higher School of Medicine, National Polytechnic Institute, Mexico City, Mexico.
| | - Diana Alemán-González-Duhart
- Department of Basic Interdisciplinary Training, Interdisciplinary Center for Health Sciences-Santo Tomás Unit, National Polytechnic Institute, Mexico City, Mexico.
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Investigation of Surrogate Biomarkers Associated with Macular Pigment Status in a Group of Older Irish Adults. Optom Vis Sci 2020; 97:879-888. [PMID: 33055512 DOI: 10.1097/opx.0000000000001587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Macular pigment (MP) confers potent antioxidant and anti-inflammatory effects at the macula; however, its optical density in the eye is not routinely measured in clinical practice. PURPOSE This study explored a range of surrogate biomarkers including anthropometric, clinical, and plasma measures that may be associated with lower MP optical density (MPOD). METHODS Two thousand five hundred ninety-four subjects completed a full MP assessment as part of wave 1 of The Irish Longitudinal Study of Aging. Macular pigment optical density was measured using customized heterochromatic flicker photometry. Clinical (blood pressure), plasma (lipoproteins, inflammatory markers), and anthropometric (waist, hip, height, weight) biomarkers were measured for each participant. RESULTS Mean (standard deviation) MPOD for the study group was 0.223 (0.161), with a range of 0 to 1.08. One-way ANOVA revealed that MPOD was significantly lower among participants with low plasma high-density lipoprotein (HDL; P = .04), raised plasma triglyceride-to-HDL ratio (P = .003), and raised total cholesterol-to-HDL ratio (P = .03). Subjects with an elevated waist circumference (WC) had a significantly lower MPOD (mean, 0.216 [0.159]) compared with those with an ideal WC (mean, 0.229 [0.162]; P = .03). Significant correlates of MPOD on mixed linear model analysis included education, smoking status, and WC. CONCLUSIONS Higher abdominal fat is associated with lower MPOD in this representative sample of older Irish adults. Although altered lipoprotein profiles (low HDL, raised triglyceride-to-HDL ratio, raised total cholesterol-to-HDL ratio) may affect the transport, uptake, and stabilization of carotenoids in the retina, these plasma biomarkers were not predictive of low MPOD after adjustment for abdominal circumference. Although WC emerged as a viable anthropometric predictor of lower MPOD, its effect size seems to be small.
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Robertson NU, Schoonees A, Brand A, Visser J. Pine bark (Pinus spp.) extract for treating chronic disorders. Cochrane Database Syst Rev 2020; 9:CD008294. [PMID: 32990945 PMCID: PMC8094515 DOI: 10.1002/14651858.cd008294.pub5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Pine bark (Pinus spp.) extract is rich in bioflavonoids, predominantly proanthocyanidins, which are antioxidants. Commercially-available extract supplements are marketed for preventing or treating various chronic conditions associated with oxidative stress. This is an update of a previously published review. OBJECTIVES To assess the efficacy and safety of pine bark extract supplements for treating chronic disorders. SEARCH METHODS We searched three databases and three trial registries; latest search: 30 September 2019. We contacted the manufacturers of pine bark extracts to identify additional studies and hand-searched bibliographies of included studies. SELECTION CRITERIA Randomised controlled trials (RCTs) evaluating pine bark extract supplements in adults or children with any chronic disorder. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial eligibility, extracted data and assessed risk of bias. Where possible, we pooled data in meta-analyses. We used GRADE to evaluate the certainty of evidence. Primary outcomes were participant- and investigator-reported clinical outcomes directly related to each disorder and all-cause mortality. We also assessed adverse events and biomarkers of oxidative stress. MAIN RESULTS This review included 27 RCTs (22 parallel and five cross-over designs; 1641 participants) evaluating pine bark extract supplements across 10 chronic disorders: asthma (two studies; 86 participants); attention deficit hyperactivity disorder (ADHD) (one study; 61 participants), cardiovascular disease (CVD) and risk factors (seven studies; 338 participants), chronic venous insufficiency (CVI) (two studies; 60 participants), diabetes mellitus (DM) (six studies; 339 participants), erectile dysfunction (three studies; 277 participants), female sexual dysfunction (one study; 83 participants), osteoarthritis (three studies; 293 participants), osteopenia (one study; 44 participants) and traumatic brain injury (one study; 60 participants). Two studies exclusively recruited children; the remainder recruited adults. Trials lasted between four weeks and six months. Placebo was the control in 24 studies. Overall risk of bias was low for four, high for one and unclear for 22 studies. In adults with asthma, we do not know whether pine bark extract increases change in forced expiratory volume in one second (FEV1) % predicted/forced vital capacity (FVC) (mean difference (MD) 7.70, 95% confidence interval (CI) 3.19 to 12.21; one study; 44 participants; very low-certainty evidence), increases change in FEV1 % predicted (MD 7.00, 95% CI 0.10 to 13.90; one study; 44 participants; very low-certainty evidence), improves asthma symptoms (risk ratio (RR) 1.85, 95% CI 1.32 to 2.58; one study; 60 participants; very low-certainty evidence) or increases the number of people able to stop using albuterol inhalers (RR 6.00, 95% CI 1.97 to 18.25; one study; 60 participants; very low-certainty evidence). In children with ADHD, we do not know whether pine bark extract decreases inattention and hyperactivity assessed by parent- and teacher-rating scales (narrative synthesis; one study; 57 participants; very low-certainty evidence) or increases the change in visual-motoric coordination and concentration (MD 3.37, 95% CI 2.41 to 4.33; one study; 57 participants; very low-certainty evidence). In participants with CVD, we do not know whether pine bark extract decreases diastolic blood pressure (MD -3.00 mm Hg, 95% CI -4.51 to -1.49; one study; 61 participants; very low-certainty evidence); increases HDL cholesterol (MD 0.05 mmol/L, 95% CI -0.01 to 0.11; one study; 61 participants; very low-certainty evidence) or decreases LDL cholesterol (MD -0.03 mmol/L, 95% CI -0.05 to 0.00; one study; 61 participants; very low-certainty evidence). In participants with CVI, we do not know whether pine bark extract decreases pain scores (MD -0.59, 95% CI -1.02 to -0.16; one study; 40 participants; very low-certainty evidence), increases the disappearance of pain (RR 25.0, 95% CI 1.58 to 395.48; one study; 40 participants; very low-certainty evidence) or increases physician-judged treatment efficacy (RR 4.75, 95% CI 1.97 to 11.48; 1 study; 40 participants; very low-certainty evidence). In type 2 DM, we do not know whether pine bark extract leads to a greater reduction in fasting blood glucose (MD 1.0 mmol/L, 95% CI 0.91 to 1.09; one study; 48 participants;very low-certainty evidence) or decreases HbA1c (MD -0.90 %, 95% CI -1.78 to -0.02; 1 study; 48 participants; very low-certainty evidence). In a mixed group of participants with type 1 and type 2 DM we do not know whether pine bark extract decreases HbA1c (MD -0.20 %, 95% CI -1.83 to 1.43; one study; 67 participants; very low-certainty evidence). In men with erectile dysfunction, we do not know whether pine bark extract supplements increase International Index of Erectile Function-5 scores (not pooled; two studies; 147 participants; very low-certainty evidence). In women with sexual dysfunction, we do not know whether pine bark extract increases satisfaction as measured by the Female Sexual Function Index (MD 5.10, 95% CI 3.49 to 6.71; one study; 75 participants; very low-certainty evidence) or leads to a greater reduction of pain scores (MD 4.30, 95% CI 2.69 to 5.91; one study; 75 participants; very low-certainty evidence). In adults with osteoarthritis of the knee, we do not know whether pine bark extract decreases composite Western Ontario and McMaster Universities Osteoarthritis Index scores (MD -730.00, 95% CI -1011.95 to -448.05; one study; 37 participants; very low-certainty evidence) or the use of non-steroidal anti-inflammatory medication (MD -18.30, 95% CI -25.14 to -11.46; one study; 35 participants; very low-certainty evidence). We do not know whether pine bark extract increases bone alkaline phosphatase in post-menopausal women with osteopenia (MD 1.16 ug/L, 95% CI -2.37 to 4.69; one study; 40 participants; very low-certainty evidence). In individuals with traumatic brain injury, we do not know whether pine bark extract decreases cognitive failure scores (MD -2.24, 95% CI -11.17 to 6.69; one study; 56 participants; very low-certainty evidence) or post-concussion symptoms (MD -0.76, 95% CI -5.39 to 3.87; one study; 56 participants; very low-certainty evidence). For most comparisons, studies did not report outcomes of hospital admissions or serious adverse events. AUTHORS' CONCLUSIONS Small sample sizes, limited numbers of RCTs per condition, variation in outcome measures, and poor reporting of the included RCTs mean no definitive conclusions regarding the efficacy or safety of pine bark extract supplements are possible.
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Affiliation(s)
- Nina U Robertson
- Division of Human Nutrition, Stellenbosch University, Cape Town, South Africa
| | - Anel Schoonees
- Centre for Evidence-based Health Care, Division of Epidemiology and Biostatistics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Amanda Brand
- Centre for Evidence-based Health Care, Division of Epidemiology and Biostatistics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Janicke Visser
- Division of Human Nutrition, Stellenbosch University, Cape Town, South Africa
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Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease. Antioxidants (Basel) 2020; 9:antiox9100905. [PMID: 32977483 PMCID: PMC7598160 DOI: 10.3390/antiox9100905] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy (DR), a common chronic complication of diabetes mellitus and the leading cause of vision loss in the working-age population, is clinically defined as a microvascular disease that involves damage of the retinal capillaries with secondary visual impairment. While its clinical diagnosis is based on vascular pathology, DR is associated with early abnormalities in the electroretinogram, indicating alterations of the neural retina and impaired visual signaling. The pathogenesis of DR is complex and likely involves the simultaneous dysregulation of multiple metabolic and signaling pathways through the retinal neurovascular unit. There is evidence that microvascular disease in DR is caused in part by altered energetic metabolism in the neural retina and specifically from signals originating in the photoreceptors. In this review, we discuss the main pathogenic mechanisms that link alterations in neural retina bioenergetics with vascular regression in DR. We focus specifically on the recent developments related to alterations in mitochondrial metabolism including energetic substrate selection, mitochondrial function, oxidation-reduction (redox) imbalance, and oxidative stress, and critically discuss the mechanisms of these changes and their consequences on retinal function. We also acknowledge implications for emerging therapeutic approaches and future research directions to find novel mitochondria-targeted therapeutic strategies to correct bioenergetics in diabetes. We conclude that retinal bioenergetics is affected in the early stages of diabetes with consequences beyond changes in ATP content, and that maintaining mitochondrial integrity may alleviate retinal disease.
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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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Mansour SE, Browning DJ, Wong K, Flynn HW, Bhavsar AR. The Evolving Treatment of Diabetic Retinopathy. Clin Ophthalmol 2020; 14:653-678. [PMID: 32184554 PMCID: PMC7061411 DOI: 10.2147/opth.s236637] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
Purpose To review the current therapeutic options for the management of diabetic retinopathy (DR) and diabetic macular edema (DME) and examine the evidence for integration of laser and pharmacotherapy. Methods A review of the PubMed database was performed using the search terms diabetic retinopathy, diabetic macular edema, neovascularization, laser photocoagulation, intravitreal injection, vascular endothelial growth factor (VEGF), vitrectomy, pars plana vitreous surgery, antiangiogenic therapy. With additional cross-referencing, this yielded 835 publications of which 301 were selected based on content and relevance. Results Many recent studies have evaluated the pharmacological, laser and surgical therapeutic strategies for the treatment and prevention of DR and DME. Several newer diagnostic systems such as optical coherence tomography (OCT), microperimetry, and multifocal electroretinography (mfERG) are also assisting in further refinements in the staging and classification of DR and DME. Pharmacological therapies for both DR and DME include both systemic and ocular agents. Systemic agents that promote intensive glycemic control, control of dyslipidemia and antagonists of the renin-angiotensin system demonstrate beneficial effects for both DR and DME. Ocular therapies include anti-VEGF agents, corticosteroids and nonsteroidal anti-inflammatory drugs. Laser therapy, both as panretinal and focal or grid applications continue to be employed in management of DR and DME. Refinements in laser devices have yielded more tissue-sparing (subthreshold) modes in which many of the benefits of conventional continuous wave (CW) lasers can be obtained without the adverse side effects. Recent attempts to lessen the burden of anti-VEGF injections by integrating laser therapy have met with mixed results. Increasingly, vitreoretinal surgical techniques are employed for less advanced stages of DR and DME. The development and use of smaller gauge instrumentation and advanced anesthesia agents have been associated with a trend toward earlier surgical intervention for diabetic retinopathy. Several novel drug delivery strategies are currently being examined with the goal of decreasing the therapeutic burden of monthly intravitreal injections. These fall into one of the five categories: non-biodegradable polymeric drug delivery systems, biodegradable polymeric drug delivery systems, nanoparticle-based drug delivery systems, ocular injection devices and with sustained release refillable devices. At present, there remains no one single strategy for the management of the particular stages of DR and DME as there are many options that have not been rigorously tested through large, randomized, controlled clinical trials. Conclusion Pharmacotherapy, both ocular and systemic, will be the primary mode of intervention in the management of DR and DME in many cases when cost and treatment burden are less constrained. Conventional laser therapy has become a secondary intervention in these instances, but remains a first-line option when cost and treatment burden are more constrained. Results with subthreshold laser appear promising but will require more rigorous study to establish its role as adjunctive therapy. Evidence to support an optimal integration of the various treatment options is lacking. Central to the widespread adoption of any therapeutic regimen for DR and DME is substantiation of safety, efficacy, and cost-effectiveness by a body of sound clinical trials.
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Affiliation(s)
- Sam E Mansour
- George Washington University, Washington, DC, USA.,Virginia Retina Center, Warrenton, VA, 20186, USA
| | - David J Browning
- Charlotte Eye Ear Nose & Throat Associates, Charlotte, NC 28210, USA
| | - Keye Wong
- Retina Associates of Sarasota, Sarasota, FL 34233, USA
| | - Harry W Flynn
- Bascom Palmer Eye Institute, University of Miami Health System, Miami, FL, USA
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Porcine models for studying complications and organ crosstalk in diabetes mellitus. Cell Tissue Res 2020; 380:341-378. [PMID: 31932949 DOI: 10.1007/s00441-019-03158-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/28/2019] [Indexed: 02/06/2023]
Abstract
The worldwide prevalence of diabetes mellitus and obesity is rapidly increasing not only in adults but also in children and adolescents. Diabetes is associated with macrovascular complications increasing the risk for cardiovascular disease and stroke, as well as microvascular complications leading to diabetic nephropathy, retinopathy and neuropathy. Animal models are essential for studying disease mechanisms and for developing and testing diagnostic procedures and therapeutic strategies. Rodent models are most widely used but have limitations in translational research. Porcine models have the potential to bridge the gap between basic studies and clinical trials in human patients. This article provides an overview of concepts for the development of porcine models for diabetes and obesity research, with a focus on genetically engineered models. Diabetes-associated ocular, cardiovascular and renal alterations observed in diabetic pig models are summarized and their similarities with complications in diabetic patients are discussed. Systematic multi-organ biobanking of porcine models of diabetes and obesity and molecular profiling of representative tissue samples on different levels, e.g., on the transcriptome, proteome, or metabolome level, is proposed as a strategy for discovering tissue-specific pathomechanisms and their molecular key drivers using systems biology tools. This is exemplified by a recent study providing multi-omics insights into functional changes of the liver in a transgenic pig model for insulin-deficient diabetes mellitus. Collectively, these approaches will provide a better understanding of organ crosstalk in diabetes mellitus and eventually reveal new molecular targets for the prevention, early diagnosis and treatment of diabetes mellitus and its associated complications.
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A review of the putative causal mechanisms associated with lower macular pigment in diabetes mellitus. Nutr Res Rev 2019; 32:247-264. [PMID: 31409441 DOI: 10.1017/s095442241900012x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Macular pigment (MP) confers potent antioxidant and anti-inflammatory effects at the macula, and may therefore protect retinal tissue from the oxidative stress and inflammation associated with ocular disease and ageing. There is a body of evidence implicating oxidative damage and inflammation as underlying pathological processes in diabetic retinopathy. MP has therefore become a focus of research in diabetes, with recent evidence suggesting that individuals with diabetes, particularly type 2 diabetes, have lower MP relative to healthy controls. The present review explores the currently available evidence to illuminate the metabolic perturbations that may possibly be involved in MP's depletion. Metabolic co-morbidities commonly associated with type 2 diabetes, such as overweight/obesity, dyslipidaemia, hyperglycaemia and insulin resistance, may have related and independent relationships with MP. Increased adiposity and dyslipidaemia may adversely affect MP by compromising the availability, transport and assimilation of these dietary carotenoids in the retina. Furthermore, carotenoid intake may be compromised by the dietary deficiencies characteristic of type 2 diabetes, thereby further compromising redox homeostasis. Candidate causal mechanisms to explain the lower MP levels reported in diabetes include increased oxidative stress, inflammation, hyperglycaemia, insulin resistance, overweight/obesity and dyslipidaemia; factors that may negatively affect redox status, and the availability, transport and stabilisation of carotenoids in the retina. Further study in diabetic populations is warranted to fully elucidate these relationships.
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Scanlon G, McCartney D, Butler JS, Loskutova E, Loughman J. Identification of Surrogate Biomarkers for the Prediction of Patients at Risk of Low Macular Pigment in Type 2 Diabetes. Curr Eye Res 2019; 44:1369-1380. [PMID: 31225969 DOI: 10.1080/02713683.2019.1635166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Purpose: This cross-sectional study compared macular pigment (MP) levels among persons with Type 2 diabetes relative to healthy controls. Additionally, a range of behavioral, anthropometric, clinical and serum measures were explored as possible predictors of low MP optical density (MPOD) in diabetes.Methods: Two health status groups; Group 1: Type 2 diabetes (n = 188), and Group 2: Healthy controls (n = 2,594) completed a full MP assessment using customized heterochromatic flicker photometry, as part of The Irish Longitudinal Study on Aging (TILDA). Clinical [blood pressure; cataract status; MPOD] and anthropometric [waist (cm); weight (kg); hip (cm)] measurements were taken, and a blood sample drawn for analysis of serum biomarkers [lipoproteins; inflammatory markers (C reactive protein and vitamin-D)].Results: One-way ANOVA revealed lower MPOD in subjects with Type 2 diabetes relative to controls (p = .047). Amongst participants with diabetes, those with low serum vitamin D (≤50 nmol/L) had significantly lower mean MPOD compared to those with sufficient serum vitamin D levels >50 nmol/L (0.173(0.148) vs. 0.226(0.145); p = .006). Concomitantly, MP was significantly lower in diabetes participants with raised serum triglyceride (TG) to high density lipoprotein (HDL) ratio (TG/HDL); values >1.74 mmol/L (0.172 (0.140) vs 0.215 (0.152); p = .039). Body mass index, waist-to-height ratio and waist circumference, were all significantly negatively correlated with MPOD (Pearson's correlation, p < .05 for all). Significant correlates of MPOD in the multivariate regression model included smoking, cataract, and vitamin D, which collectively contributed 18.5% of the overall variability in MPOD status amongst participants with Type 2 diabetes.Conclusions: This study provides additional evidence that low MP may indeed be a feature of Type 2 diabetes, and further identifies smoking, cataract and vitamin D status as plausible predictors of low MPOD amongst persons with Type 2 diabetes.
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Affiliation(s)
- Grainne Scanlon
- Centre for Eye Research Ireland, School of Physics, Clinical & Optometric Sciences, Environmental Sustainability and Health Institute, Technological University Dublin, Dublin, Ireland
| | - Daniel McCartney
- School of Biological and Health Sciences, Technological University Dublin, City Campus, Dublin, Ireland
| | - John S Butler
- Centre for Eye Research Ireland, School of Physics, Clinical & Optometric Sciences, Environmental Sustainability and Health Institute, Technological University Dublin, Dublin, Ireland.,School of Mathematical Sciences, Technological University Dublin, City Campus, Dublin, Ireland
| | - Ekaterina Loskutova
- Centre for Eye Research Ireland, School of Physics, Clinical & Optometric Sciences, Environmental Sustainability and Health Institute, Technological University Dublin, Dublin, Ireland
| | - James Loughman
- Centre for Eye Research Ireland, School of Physics, Clinical & Optometric Sciences, Environmental Sustainability and Health Institute, Technological University Dublin, Dublin, Ireland
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Whitehead M, Wickremasinghe S, Osborne A, Van Wijngaarden P, Martin KR. Diabetic retinopathy: a complex pathophysiology requiring novel therapeutic strategies. Expert Opin Biol Ther 2018; 18:1257-1270. [PMID: 30408422 PMCID: PMC6299358 DOI: 10.1080/14712598.2018.1545836] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/05/2018] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Diabetic retinopathy (DR) is the leading cause of vision loss in the working age population of the developed world. DR encompasses a complex pathology, and one that is reflected in the variety of currently available treatments, which include laser photocoagulation, glucocorticoids, vitrectomy and agents which neutralize vascular endothelial growth factor (VEGF). Whilst these options demonstrate modest clinical benefits, none is yet to fully attenuate clinical progression or reverse damage to the retina. This has led to an interest in developing novel therapies for the condition, such as mediators of angiopoietin signaling axes, immunosuppressants, nonsteroidal anti-inflammatory drugs (NSAIDs), oxidative stress inhibitors and vitriol viscosity inhibitors. Further, preclinical research suggests that gene therapy treatment for DR could provide significant benefits over existing treatments options. AREAS COVERED Here we review the pathophysiology of DR and provide an overview of currently available treatments. We then outline recent advances made towards improved patient outcomes and highlight the potential of the gene therapy paradigm to revolutionize DR management. EXPERT OPINION Whilst significant progress has been made towards our understanding of DR, further research is required to enable the development of a detailed spatiotemporal model of the disease. In addition, we hope that improvements in our knowledge of the condition facilitate therapeutic innovations that continue to address unmet medical need and improve patient outcomes, with a focus on the development of targeted medicines.
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Affiliation(s)
- Michael Whitehead
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Sanjeewa Wickremasinghe
- Centre for Eye Research Australia, University of Melbourne and Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Andrew Osborne
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Peter Van Wijngaarden
- Centre for Eye Research Australia, University of Melbourne and Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Keith R. Martin
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Eye Department, Addenbrooke’s Hospital, Cambridge, UK
- Cambridge NIHR Biomedical Research Centre, Cambridge, UK
- Wellcome Trust – MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
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Rodríguez González-Herrero ME, Ruiz M, López Román FJ, Marín Sánchez JM, Domingo JC. Supplementation with a highly concentrated docosahexaenoic acid plus xanthophyll carotenoid multivitamin in nonproliferative diabetic retinopathy: prospective controlled study of macular function by fundus microperimetry. Clin Ophthalmol 2018; 12:1011-1020. [PMID: 29881256 PMCID: PMC5983010 DOI: 10.2147/opth.s157635] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Objective There is little evidence of real-life outcomes of dietary supplementation with high-dose docosahexaenoic acid (DHA) and carotenoids in patients with diabetic retinopathy (DR). We assessed the effect of supplementation with DHA triglyceride (1,050 mg/d) + xanthophyll carotenoid multivitamin on macular function in nonproliferative DR. Methods Asymptomatic patients with nonproliferative DR were included in a prospective controlled study and assigned (1:1) to the DHA supplementation group or the control group. Macular sensitivity and macular integrity area were the main outcome measures. Functional vision measures (macular function [MAIA™ CenterVue], best-corrected visual acuity), structural retinal measures (central subfield macular thickness), and biochemical parameters (plasma total antioxidant capacity, DHA content of the erythrocyte membrane, and plasma IL-6) were evaluated at baseline and after 45 and 90 days of DHA supplementation. Results The study included 24 patients (48 eyes) (12 patients, 24 eyes in each group). Baseline clinical characteristics of patients in both groups were similar. Macular sensitivity increased from a mean (SD) of 25.9 (2.4) dB at baseline to 27.3 (2.3) dB at 90 days (P=0.030) in the DHA group only (between-group differences P<0.19). The macular integrity index decreased from 71.2 (33.2) at baseline to 63.5 (36.4) at 45 days and to 51.6 (35.9) at 90 days (P=0.002) in the DHA group only (between-group differences P<0.05). Best-corrected visual acuity and central subfield macular thickness did not vary significantly in any of the comparisons and in none of the groups. DHA content of erythrocyte membrane and total antioxidant capacity levels increased significantly only in the DHA group. Plasma IL-6 levels decreased significantly only in the DHA group. Conclusion In an early stage of DR, supplementation with high-dose DHA plus xanthophyll carotenoid multivitamin during 90 days was associated with a progressive and significant improvement of macular function measured by microperimetry. Biochemical changes supported the effect of DHA.
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Affiliation(s)
| | - Marcos Ruiz
- Service of Ophthalmology, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Francisco Javier López Román
- Department of Exercise Physiology, Faculty of Health Sciences, San Antonio Catholic University of Murcia (UCAM), Murcia, Spain
| | | | - Joan Carles Domingo
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain
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Kowluru RA, Mishra M. Therapeutic targets for altering mitochondrial dysfunction associated with diabetic retinopathy. Expert Opin Ther Targets 2018; 22:233-245. [PMID: 29436254 PMCID: PMC6088375 DOI: 10.1080/14728222.2018.1439921] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Retinopathy remains as one of the most feared blinding complications of diabetes, and with the prevalence of this life-long disease escalating at an alarming rate, the incidence of retinopathy is also climbing. Although the cutting edge research has identified many molecular mechanisms associated with its development, the exact mechanism how diabetes damages the retina remains obscure, limiting therapeutic options for this devastating disease. Areas covered: This review focuses on the central role of mitochondrial dysfunction/damage in the pathogenesis of diabetic retinopathy, and how damaged mitochondria initiates a self-perpetuating vicious cycles of free radicals. We have also reviewed how mitochondria could serve as a therapeutic target, and the challenges associated with the complex double mitochondrial membranes and a well-defined blood-retinal barrier for optimal pharmacologic/molecular approach to improve mitochondrial function. Expert opinion: Mitochondrial dysfunction provides many therapeutic targets for ameliorating the development of diabetic retinopathy including their biogenesis, DNA damage and epigenetic modifications. New technology to enhance pharmaceuticals uptake inside the mitochondria, nanotechnology to deliver drugs to the retina, and maintenance of mitochondrial homeostasis via lifestyle changes and novel therapeutics to prevent epigenetic modifications, could serve as some of the welcoming avenues for a diabetic patient to target this sight-threatening disease.
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Affiliation(s)
- Renu A Kowluru
- a Department of Ophthalmology, Kresge Eye Institute , Wayne State University , Detroit , MI , USA
| | - Manish Mishra
- a Department of Ophthalmology, Kresge Eye Institute , Wayne State University , Detroit , MI , USA
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Moschos MM, Dettoraki M, Tsatsos M, Kitsos G, Kalogeropoulos C. Effect of carotenoids dietary supplementation on macular function in diabetic patients. EYE AND VISION 2017; 4:23. [PMID: 29046877 PMCID: PMC5641400 DOI: 10.1186/s40662-017-0088-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/29/2017] [Indexed: 01/25/2023]
Abstract
Background Diabetic retinopathy is a major cause of visual impairment and blindness among working-age people worldwide. The aim of our study was to investigate the effects of a carotenoid supplementation on retinal thickness and macular function of patients with diabetes using optical coherence tomography (OCT) and multifocal electroretinography (mfERG). Methods A retrospective study of one hundred and twenty eyes of sixty patients age between 40 and 60 years with non-insulin dependent type 2 diabetes mellitus without diabetic retinopathy who underwent OCT and mfERG and took vitamin supplements for a period of two years. Patients received a carotenoid supplement containing lutein (10 mg), zeaxanthin (2 mg) and meso-zeaxanthin (10 mg) once a day for two years. The thickness of the fovea was evaluated using OCT and the macular function was tested by mfERG. Results OCT showed an increase in the central foveal thickness and mfERG revealed increased retinal response density within the central 13° surrounding the fovea (rings 1 to 3) at two years after the onset of carotenoids supplement intake. Conclusion The use of carotenoid supplements may be of benefit for improving visual function of type 2 diabetes patients. However, further study is needed to assess the treatment’s long-term efficacy.
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Affiliation(s)
- Marilita M Moschos
- First Department of Ophthalmology, Medical School, National and Kapodistrian University of Athens, 6 Ikarias street, Ekali, 14578 Athens, Greece
| | - Maria Dettoraki
- First Department of Ophthalmology, Medical School, National and Kapodistrian University of Athens, 6 Ikarias street, Ekali, 14578 Athens, Greece
| | - Michael Tsatsos
- Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - George Kitsos
- Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece
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Kleinwort KJH, Amann B, Hauck SM, Hirmer S, Blutke A, Renner S, Uhl PB, Lutterberg K, Sekundo W, Wolf E, Deeg CA. Retinopathy with central oedema in an INS C94Y transgenic pig model of long-term diabetes. Diabetologia 2017; 60:1541-1549. [PMID: 28480495 DOI: 10.1007/s00125-017-4290-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/29/2017] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Diabetic retinopathy is a severe complication of diabetes mellitus that often leads to blindness. Because the pathophysiology of diabetic retinopathy is not fully understood and novel therapeutic interventions require testing, there is a need for reliable animal models that mimic all the complications of diabetic retinopathy. Pig eyes share important anatomical and physiological similarities with human eyes. Previous studies have demonstrated that INS C94Y transgenic pigs develop a stable diabetic phenotype and ocular alterations such as cataracts. The aim of this study was to conduct an in-depth analysis of pathological changes in retinas from INS C94Y pigs exposed to hyperglycaemia for more than 2 years, representing a chronic diabetic condition. METHODS Eyes from six INS C94Ypigs and six age-matched control littermates were analysed via histology and immunohistochemistry. For histological analyses of retinal (layer) thickness, sections were stained with H&E or Mallory's trichrome. For comparison of protein expression patterns and vessel courses, sections were stained with different antibodies in immunohistochemistry. Observed lesions were compared with reported pathologies in human diabetic retinopathy. RESULTS INS C94Ypigs developed several signs of diabetic retinopathy similar to those seen in humans, such as intraretinal microvascular abnormalities, symptoms of proliferative diabetic retinopathy and central retinal oedema in a region that is cone rich, like the human macula. CONCLUSIONS/INTERPRETATION The INS C94Ypig is an interesting model for studying the pathophysiology of diabetic retinopathy and for testing novel therapeutic strategies.
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Affiliation(s)
- Kristina J H Kleinwort
- Institute of Animal Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Barbara Amann
- Institute of Animal Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Centre for Environmental Health GmbH, Munich, Germany
- German Centre for Diabetes Research (DZD), Neuherberg, Germany
| | - Sieglinde Hirmer
- Institute of Animal Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Andreas Blutke
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, LMU Munich, Munich, Germany
| | - Simone Renner
- German Centre for Diabetes Research (DZD), Neuherberg, Germany
- Molecular Animal Breeding and Biotechnology, Gene Centre, LMU Munich, Munich, Germany
| | - Patrizia B Uhl
- Institute of Animal Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Karina Lutterberg
- Institute of Animal Physiology, Department of Veterinary Sciences, LMU Munich, Munich, Germany
| | - Walter Sekundo
- Department of Ophthalmology, Philipps University of Marburg, Marburg, Germany
| | - Eckhard Wolf
- German Centre for Diabetes Research (DZD), Neuherberg, Germany
- Molecular Animal Breeding and Biotechnology, Gene Centre, LMU Munich, Munich, Germany
| | - Cornelia A Deeg
- Experimental Ophthalmology, Philipps University of Marburg, Baldingerstrasse, D-35033, Marburg, Germany.
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Abstract
Current evidence suggests lutein and its isomers play important roles in ocular development in utero and throughout the life span, in vision performance in young and later adulthood, and in lowering risk for the development of common age-related eye diseases in older age. These xanthophyll (oxygen-containing) carotenoids are found in a wide variety of vegetables and fruits, and they are present in especially high concentrations in leafy green vegetables. Additionally, egg yolks and human milk appear to be bioavailable sources. The prevalence of lutein, zeaxanthin, and meso-zeaxanthin in supplements is increasing. Setting optimal and safe ranges of intake requires additional research, particularly in pregnant and lactating women. Accumulating evidence about variable interindividual response to dietary intake of these carotenoids, based on genetic or metabolic influences, suggests that there may be subgroups that benefit from higher levels of intake and/or alternate strategies to improve lutein and zeaxanthin status.
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Affiliation(s)
- Julie Mares
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin 53726-2336;
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Wang H, Daggy BP. The Role of Fish Oil in Inflammatory Eye Diseases. Biomed Hub 2017; 2:1-12. [PMID: 31988905 PMCID: PMC6945974 DOI: 10.1159/000455818] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/03/2017] [Indexed: 12/14/2022] Open
Abstract
Consumption of fish oil is associated with reduced morbidity and mortality of cardiovascular diseases and also reduces the severity of many other inflammatory diseases and autoimmune disorders. The beneficial effects are attributed to the anti-inflammatory effects of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish oils. The mechanism of the anti-inflammatory effects was long thought to be by modulating the production of proinflammatory mediators, including prostaglandins, thromboxanes, and leukotrienes. Recent advances in research into the novel lipid mediators (resolvins, protectins, and maresins) derived from EPA and DHA and their role in the resolution of inflammation have shed new light on the pleiotropic nature of these fatty acids. In this review, we focus on the effects of EPA and DHA from fish oil in the treatment of two common inflammatory eye diseases - dry eye disease and age-related macular degeneration. Evidence from recent studies lends support to a role of fish oil in the treatment of these two eye diseases.
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Affiliation(s)
- Hong Wang
- Research and Development, Shaklee Corporation, Pleasanton, CA, USA
| | - Bruce P Daggy
- Research and Development, Shaklee Corporation, Pleasanton, CA, USA
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Sommese L, Zullo A, Mancini FP, Fabbricini R, Soricelli A, Napoli C. Clinical relevance of epigenetics in the onset and management of type 2 diabetes mellitus. Epigenetics 2017; 12:401-415. [PMID: 28059593 DOI: 10.1080/15592294.2016.1278097] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Epigenetics is involved in the altered expression of gene networks that underlie insulin resistance and insufficiency. Major genes controlling β-cell differentiation and function, such as PAX4, PDX1, and GLP1 receptor, are epigenetically controlled. Epigenetics can cause insulin resistance through immunomediated pro-inflammatory actions related to several factors, such as NF-kB, osteopontin, and Toll-like receptors. Hereafter, we provide a critical and comprehensive summary on this topic with a particular emphasis on translational and clinical aspects. We discuss the effect of epigenetics on β-cell regeneration for cell replacement therapy, the emerging bioinformatics approaches for analyzing the epigenetic contribution to type 2 diabetes mellitus (T2DM), the epigenetic core of the transgenerational inheritance hypothesis in T2DM, and the epigenetic clinical trials on T2DM. Therefore, prevention or reversion of the epigenetic changes occurring during T2DM development may reduce the individual and societal burden of the disease.
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Affiliation(s)
- Linda Sommese
- a U.O.C. Clinical Immunology, Immunohematology, Transfusion Medicine and Transplant Immunology, Regional Reference Laboratory of Transplant Immunology , Department of Internal and Specialty Medicine , Azienda Ospedaliera Universitaria (AOU), Università degli Studi della Campania "Luigi Vanvitelli ," Italy.,b Department of Experimental Medicine , Second University of Naples , Italy
| | - Alberto Zullo
- c Department of Sciences and Technologies , University of Sannio , Benevento , Italy.,d CEINGE-Advanced Biotechnologies , Naples , Italy
| | | | - Rossella Fabbricini
- a U.O.C. Clinical Immunology, Immunohematology, Transfusion Medicine and Transplant Immunology, Regional Reference Laboratory of Transplant Immunology , Department of Internal and Specialty Medicine , Azienda Ospedaliera Universitaria (AOU), Università degli Studi della Campania "Luigi Vanvitelli ," Italy
| | - Andrea Soricelli
- e IRCCS Research Institute SDN , Naples , Italy.,f Department of Studies of Institutions and Territorial Systems , University of Naples Parthenope , Naples , Italy
| | - Claudio Napoli
- a U.O.C. Clinical Immunology, Immunohematology, Transfusion Medicine and Transplant Immunology, Regional Reference Laboratory of Transplant Immunology , Department of Internal and Specialty Medicine , Azienda Ospedaliera Universitaria (AOU), Università degli Studi della Campania "Luigi Vanvitelli ," Italy.,e IRCCS Research Institute SDN , Naples , Italy.,g Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences , Second University of Naples , Italy
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Safi S, Rahimi A, Raeesi A, Safi H, Aghazadeh Amiri M, Malek M, Yaseri M, Haeri M, Middleton FA, Solessio E, Ahmadieh H. Contrast sensitivity to spatial gratings in moderate and dim light conditions in patients with diabetes in the absence of diabetic retinopathy. BMJ Open Diabetes Res Care 2017; 5:e000408. [PMID: 28878937 PMCID: PMC5574432 DOI: 10.1136/bmjdrc-2017-000408] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/29/2017] [Accepted: 05/15/2017] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVE To evaluate the ability of contrast sensitivity (CS) to discriminate loss of visual function in diabetic subjects with no clinical signs of retinopathy relative to that of normal subjects. RESEARCH DESIGN AND METHODS In this prospective cross-sectional study, we measured CS in 46 diabetic subjects with a mean age of 48±6 years, a best-corrected visual acuity of 20/20 and no signs of diabetic retinopathy. The CS in these subjects was compared with CS measurements in 46 normal control subjects at four spatial frequencies (3, 6, 12, 18 cycles per degree) under moderate (500 lux) and dim (less than 2 lux) background light conditions. RESULTS CS was approximately 0.16 log units lower in patients with diabetes relative to controls both in moderate and in dim background light conditions. Logistic regression classification and receiver operating characteristic curve analysis indicated that CS analysis using two light conditions was more accurate (0.78) overall compared with CS analysis using only a single illumination condition (accuracy values were 0.67 and 0.70 in moderate and dim light conditions, respectively). CONCLUSIONS Our results showed that patients with diabetes without clinical signs of retinopathy exhibit a uniform loss in CS at all spatial frequencies tested. Measuring the loss in CS at two spatial frequencies (3 and 6 cycles per degree) and two light conditions (moderate and dim) is sufficiently robust to classify diabetic subjects with no retinopathy versus control subjects.
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Affiliation(s)
- Sare Safi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Anoushiravan Rahimi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Afsaneh Raeesi
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Safi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Aghazadeh Amiri
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mojtaba Malek
- Endocrine Research Center, Firouzgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Yaseri
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Haeri
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Frank A Middleton
- Department of Neuroscience & Physiology, Institute for Human Performance, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Eduardo Solessio
- Department of Ophthalmology, Center for Vision Research, Upstate Medical University, Syracuse, New York, USA
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Bolinger MT, Antonetti DA. Moving Past Anti-VEGF: Novel Therapies for Treating Diabetic Retinopathy. Int J Mol Sci 2016; 17:E1498. [PMID: 27618014 PMCID: PMC5037775 DOI: 10.3390/ijms17091498] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/22/2016] [Accepted: 08/30/2016] [Indexed: 12/25/2022] Open
Abstract
Diabetic retinopathy is the leading cause of blindness in working age adults, and is projected to be a significant future health concern due to the rising incidence of diabetes. The recent advent of anti-vascular endothelial growth factor (VEGF) antibodies has revolutionized the treatment of diabetic retinopathy but a significant subset of patients fail to respond to treatment. Accumulating evidence indicates that inflammatory cytokines and chemokines other than VEGF may contribute to the disease process. The current review examines the presence of non-VEGF cytokines in the eyes of patients with diabetic retinopathy and highlights mechanistic pathways in relevant animal models. Finally, novel drug targets including components of the kinin-kallikrein system and emerging treatments such as anti-HPTP (human protein tyrosine phosphatase) β antibodies are discussed. Recognition of non-VEGF contributions to disease pathogenesis may lead to novel therapeutics to enhance existing treatments for patients who do not respond to anti-VEGF therapies.
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Affiliation(s)
- Mark T Bolinger
- Departments of Ophthalmology and Visual Sciences, Kellogg Eye Center, and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
| | - David A Antonetti
- Departments of Ophthalmology and Visual Sciences, Kellogg Eye Center, and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
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Oxidative stress and epigenetic modifications in the pathogenesis of diabetic retinopathy. Prog Retin Eye Res 2015; 48:40-61. [PMID: 25975734 DOI: 10.1016/j.preteyeres.2015.05.001] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/29/2015] [Accepted: 05/01/2015] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy remains the major cause of blindness among working age adults. Although a number of metabolic abnormalities have been associated with its development, due to complex nature of this multi-factorial disease, a link between any specific abnormality and diabetic retinopathy remains largely speculative. Diabetes increases oxidative stress in the retina and its capillary cells, and overwhelming evidence suggests a bidirectional relationship between oxidative stress and other major metabolic abnormalities implicated in the development of diabetic retinopathy. Due to increased production of cytosolic reactive oxygen species, mitochondrial membranes are damaged and their membrane potentials are impaired, and complex III of the electron transport system is compromised. Suboptimal enzymatic and nonenzymatic antioxidant defense system further aids in the accumulation of free radicals. As the duration of the disease progresses, mitochondrial DNA (mtDNA) is damaged and the DNA repair system is compromised, and due to impaired transcription of mtDNA-encoded proteins, the integrity of the electron transport system is encumbered. Due to decreased mtDNA biogenesis and impaired transcription, superoxide accumulation is further increased, and the vicious cycle of free radicals continues to self-propagate. Diabetic milieu also alters enzymes responsible for DNA and histone modifications, and various genes important for mitochondrial homeostasis, including mitochondrial biosynthesis, damage and antioxidant defense, undergo epigenetic modifications. Although antioxidant administration in animal models has yielded encouraging results in preventing diabetic retinopathy, controlled longitudinal human studies remain to be conducted. Furthermore, the role of epigenetic in mitochondrial homeostasis suggests that regulation of such modifications also has potential to inhibit/retard the development of diabetic retinopathy.
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