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Batagov A, Dalan R, Wu A, Lai W, Tan CS, Eisenhaber F. Generalized metabolic flux analysis framework provides mechanism-based predictions of ophthalmic complications in type 2 diabetes patients. Health Inf Sci Syst 2023; 11:18. [PMID: 37008895 PMCID: PMC10060506 DOI: 10.1007/s13755-023-00218-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 02/19/2023] [Indexed: 03/31/2023] Open
Abstract
Chronic metabolic diseases arise from changes in metabolic fluxes through biomolecular pathways and gene networks accumulated over the lifetime of an individual. While clinical and biochemical profiles present just real-time snapshots of the patients' health, efficient computation models of the pathological disturbance of biomolecular processes are required to achieve individualized mechanistic insights into disease progression. Here, we describe the Generalized metabolic flux analysis (GMFA) for addressing this gap. Suitably grouping individual metabolites/fluxes into pools simplifies the analysis of the resulting more coarse-grain network. We also map non-metabolic clinical modalities onto the network with additional edges. Instead of using the time coordinate, the system status (metabolite concentrations and fluxes) is quantified as function of a generalized extent variable (a coordinate in the space of generalized metabolites) that represents the system's coordinate along its evolution path and evaluates the degree of change between any two states on that path. We applied GMFA to analyze Type 2 Diabetes Mellitus (T2DM) patients from two cohorts: EVAS (289 patients from Singapore) and NHANES (517) from the USA. Personalized systems biology models (digital twins) were constructed. We deduced disease dynamics from the individually parameterized metabolic network and predicted the evolution path of the metabolic health state. For each patient, we obtained an individual description of disease dynamics and predict an evolution path of the metabolic health state. Our predictive models achieve an ROC-AUC in the range 0.79-0.95 (sensitivity 80-92%, specificity 62-94%) in identifying phenotypes at the baseline and predicting future development of diabetic retinopathy and cataract progression among T2DM patients within 3 years from the baseline. The GMFA method is a step towards realizing the ultimate goal to develop practical predictive computational models for diagnostics based on systems biology. This tool has potential use in chronic disease management in medical practice. Supplementary Information The online version contains supplementary material available at 10.1007/s13755-023-00218-x.
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Affiliation(s)
- Arsen Batagov
- Mesh Bio Pte. Ltd., 10 Anson Rd, #22-02, 079903 Singapore, Singapore
| | - Rinkoo Dalan
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Andrew Wu
- Mesh Bio Pte. Ltd., 10 Anson Rd, #22-02, 079903 Singapore, Singapore
| | - Wenbin Lai
- Mesh Bio Pte. Ltd., 10 Anson Rd, #22-02, 079903 Singapore, Singapore
| | - Colin S. Tan
- Fundus Image Reading Center, National Healthcare Group Eye Institute, Singapore, Singapore
- Tan Tock Seng Hospital, National Healthcare Group Eye Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | - Frank Eisenhaber
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- School of Biological Science (SBS), Nanyang Technological University, Singapore, Singapore
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Hammad SM, Lopes-Virella MF. Circulating Sphingolipids in Insulin Resistance, Diabetes and Associated Complications. Int J Mol Sci 2023; 24:14015. [PMID: 37762318 PMCID: PMC10531201 DOI: 10.3390/ijms241814015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Sphingolipids play an important role in the development of diabetes, both type 1 and type 2 diabetes, as well as in the development of both micro- and macro-vascular complications. Several reviews have been published concerning the role of sphingolipids in diabetes but most of the emphasis has been on the possible mechanisms by which sphingolipids, mainly ceramides, contribute to the development of diabetes. Research on circulating levels of the different classes of sphingolipids in serum and in lipoproteins and their importance as biomarkers to predict not only the development of diabetes but also of its complications has only recently emerged and it is still in its infancy. This review summarizes the previously published literature concerning sphingolipid-mediated mechanisms involved in the development of diabetes and its complications, focusing on how circulating plasma sphingolipid levels and the relative content carried by the different lipoproteins may impact their role as possible biomarkers both in the development of diabetes and mainly in the development of diabetic complications. Further studies in this field may open new therapeutic avenues to prevent or arrest/reduce both the development of diabetes and progression of its complications.
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Affiliation(s)
- Samar M. Hammad
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Maria F. Lopes-Virella
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
- Ralph H. Johnson VA Medical Center, Charleston, SC 29425, USA
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Aldosari DI, Malik A, Alhomida AS, Ola MS. Implications of Diabetes-Induced Altered Metabolites on Retinal Neurodegeneration. Front Neurosci 2022; 16:938029. [PMID: 35911994 PMCID: PMC9328693 DOI: 10.3389/fnins.2022.938029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the major complications of diabetic eye diseases, causing vision loss and blindness worldwide. The concept of diabetic retinopathy has evolved from microvascular disease into more complex neurovascular disorders. Early in the disease progression of diabetes, the neuronal and glial cells are compromised before any microvascular abnormalities clinically detected by the ophthalmoscopic examination. This implies understanding the pathophysiological mechanisms at the early stage of disease progression especially due to diabetes-induced metabolic alterations to damage the neural retina so that early intervention and treatments options can be identified to prevent and inhibit the progression of DR. Hyperglycemia has been widely considered the major contributor to the progression of the retinal damage, even though tight control of glucose does not seem to have a bigger effect on the incidence or progression of retinal damage that leads to DR. Emerging evidence suggests that besides diabetes-induced hyperglycemia, dyslipidemia and amino acid defects might be a major contributor to the progression of early neurovascular retinal damage. In this review, we have discussed recent advances in the alterations of key metabolites of carbohydrate, lipid, and amino acids and their implications for neurovascular damage in DR.
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Mondal LK, Pramanik S, Chowdhury S, Bose C, Bera D, Saha A, Bhattacharjee K. Do different lipid components accelerate the pathogenesis and severity of Diabetic Retinopathy? Int J Retina Vitreous 2022; 8:39. [PMID: 35690853 PMCID: PMC9188217 DOI: 10.1186/s40942-022-00390-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To assess the association of lipid and lipid-derived toxic molecules in pathogenesis and severity of diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM). METHODS The present cross-sectional study included 14 healthy individuals (HC) without T2DM, 22 T2DM subjects without DR (DNR), 24 T2DM subjects with mild non-proliferative DR (MNPDR), and 24 T2DM subjects with high-risk proliferative DR (HRPDR). All subjects underwent plasma and vitreous analysis for estimation of total lipid (TL), free fatty acid (FFA), lipid peroxides (LPOs) like malondialdehyde (MDA), 4-Hydroxy-noneal (HNE), the advanced lipoxidation end product (ALE) like Hexanoyl-lysine (HLY) and vascular endothelial growth factor (VEGF) following standard spectrophotometric and enzyme-linked immunosorbent assay (ELISA) methods respectively. RESULTS The concentration of TL, FFA, markers of lipid peroxidation and lipoxidation as well as VEGF in plasma and vitreous were found to be significantly elevated stepwise inT2DM subjects (HRPDR > MNPDR > DNR) compared to healthy controls (HC).Further, plasma conventional lipid components like total cholesterol (TCH), low density lipoprotein cholesterol (LDL-C) and triglycerides (TG), FFA and TL showed their significant positive correlations with vitreous level of different LPOs, ALE and VEGF in the DR group. CONCLUSION Total lipid and lipid-derived detrimental biomolecules ultimately result in increased secretion of VEGF and thus not only add as associated mediators in the pathogenesis of DR, these also accelerate the severity of microangiopathy in T2DM.
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Affiliation(s)
- Lakshmi Kanta Mondal
- Department of Ophthalmology, Regional Institute of Ophthalmology, Medical College Campus, Kolkata, 700 073, West Bengal, India.
| | - Subhasish Pramanik
- Department of Endocrinology & Metabolism, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, 700020, West Bengal, India
| | - Subhankar Chowdhury
- Department of Endocrinology & Metabolism, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, 700020, West Bengal, India
| | - Chiranjit Bose
- Department of Endocrinology & Metabolism, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, 700020, West Bengal, India
| | - Debgopal Bera
- Department of Endocrinology & Metabolism, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, 700020, West Bengal, India
| | - Ayindrila Saha
- Department of Rheumatology, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, 700020, West Bengal, India
| | - Koena Bhattacharjee
- Department of Ophthalmology, Regional Institute of Ophthalmology, Medical College Campus, Kolkata, 700 073, West Bengal, India
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Indumathi A, Senthilkumar GP, Jayashree K, Ramesh Babu K. Assessment of circulating fibrotic proteins (periostin and tenascin -C) In Type 2 diabetes mellitus patients with and without retinopathy. Endocrine 2022; 76:570-577. [PMID: 35274283 DOI: 10.1007/s12020-022-03027-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/16/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE Diabetic retinopathy is a leading cause of vision impairment. Surging diabetic population and poor visual care raises the need for better diagnostic tools. Hence, it is worthwhile to look for biomarkers associated with the disease pathogenesis. Periostin and tenascin-C are matricellular proteins mediating fibrillogenesis in retinopathy. Their serum levels and association with the presence and severity of retinopathy in diabetics is of importance to be explored. METHODS The study involved two groups of type 2 diabetes patients, 38 controls without retinopathy and 38 cases with retinopathy. We obtained serum sample and performed biochemical autoanalysis for routine parameters. Special parameters periostin, tenascin-C, and C-peptide were estimated by ELISA. RESULTS Periostin and tenascin-C were significantly elevated in the retinopathy group. Periostin progressively increased among subgroups. C-peptide decreased significantly in retinopathy group and had a negative correlation with duration of DM, duration of retinopathy, HbA1c and tenascin-C. We observed a positive correlation for periostin and tenascin-C with duration of diabetes. The AUC for C-peptide was the highest (0.750) amongst our parameters. HOMA 2 (%B) index was significantly lower in retinopathy group. CONCLUSIONS Serum Levels of PO and TnC increased in retinopathy. As the disease advances, periostin level increases, indicating continuing fibrosis and fibrovascular membrane formation. Periostin and tenascin-C increase with duration of retinopathy whereas levels of C-peptide decrease. C-peptide has a better differentiating potential for DR from DM. Reduced insulin production as indicated by declined HOMA 2-%BETA in retinopathy favors hyperglycemia and chronic inflammatory state for the disease progression.
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Affiliation(s)
- A Indumathi
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
| | | | - Kuppuswamy Jayashree
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
| | - K Ramesh Babu
- Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
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Behl T, Kumar K, Singh S, Sehgal A, Sachdeva M, Bhatia S, Al-Harrasi A, Buhas C, Teodora Judea-Pusta C, Negrut N, Alexandru Munteanu M, Brisc C, Bungau S. Unveiling the role of polyphenols in diabetic retinopathy. J Funct Foods 2021. [DOI: https://doi.org/10.1016/j.jff.2021.104608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Iyer SS, Lagrew MK, Tillit SM, Roohipourmoallai R, Korntner S. The Vitreous Ecosystem in Diabetic Retinopathy: Insight into the Patho-Mechanisms of Disease. Int J Mol Sci 2021; 22:ijms22137142. [PMID: 34281192 PMCID: PMC8269048 DOI: 10.3390/ijms22137142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 12/22/2022] Open
Abstract
Diabetic retinopathy is one of the leading causes of blindness in the world with the incidence of disease ever-increasing worldwide. The vitreous humor represents an extensive and complex interactive arena for cytokines in the diabetic eye. In recent decades, there has been significant progress in understanding this environment and its implications in disease pathophysiology. In this review, we investigate the vitreous ecosystem in diabetic retinopathy at the molecular level. Areas of concentration include: the current level of knowledge of growth factors, cytokine and chemokine mediators, and lipid-derived metabolites in the vitreous. We discuss the molecular patho-mechanisms of diabetic retinopathy based upon current vitreous research.
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Kumari N, Karmakar A, Ahamad Khan MM, Ganesan SK. The potential role of m6A RNA methylation in diabetic retinopathy. Exp Eye Res 2021; 208:108616. [PMID: 33979630 DOI: 10.1016/j.exer.2021.108616] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 03/19/2021] [Accepted: 05/05/2021] [Indexed: 01/10/2023]
Abstract
Diabetic retinopathy (DR), a major microvascular complication of diabetes, affects most diabetic individuals and has become the leading cause of vision loss. Metabolic memory associated with diabetes retains the risk of disease occurrence even after the termination of glycemic insult. Further, various limitations associated with its current diagnostic and treatment strategies like unavailability of early diagnostic and treatment methods, variation in treatment response from patient to patient, and cost-effectiveness have driven the need to find alternative solutions. Post-transcriptional epigenetic modification of RNA mainly, N6-methyladenosine (m6A), is an emerging concept in the scientific community. It has an indispensable effect in various physiological and pathological conditions. m6A mediates its effect through the various reader, writer, and eraser proteins. Recent studies have shown the impact of m6A RNA modification on various disease conditions, including diabetes, but its role in diabetic retinopathy is still unclear. However, change in m6A levels has been observed in various prime aggravators of DR pathogenesis, such as inflammation, oxidative stress, and angiogenesis. Further, various non-coding RNAs like microRNA, lncRNA, and circRNA are also associated with DR, and m6A has been shown to affect all these non-coding RNAs. This review is concerned with the possible mechanisms through which alteration in m6A modification of RNA can participate in the DR progression and pathogenesis and its expected role in metabolic memory phenomena.
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Affiliation(s)
- Nidhi Kumari
- Department of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India; CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Aditi Karmakar
- Department of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India; CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Md Maqsood Ahamad Khan
- Centre of Bioinformatics, Institute of Interdisciplinary Studies, University of Allahabad, Prayagraj, India
| | - Senthil Kumar Ganesan
- Department of Structural Biology & Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India; CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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10
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Simon MV, Basu SK, Qaladize B, Grambergs R, Rotstein NP, Mandal N. Sphingolipids as critical players in retinal physiology and pathology. J Lipid Res 2021; 62:100037. [PMID: 32948663 PMCID: PMC7933806 DOI: 10.1194/jlr.tr120000972] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/04/2020] [Indexed: 12/24/2022] Open
Abstract
Sphingolipids have emerged as bioactive lipids involved in the regulation of many physiological and pathological processes. In the retina, they have been established to participate in numerous processes, such as neuronal survival and death, proliferation and migration of neuronal and vascular cells, inflammation, and neovascularization. Dysregulation of sphingolipids is therefore crucial in the onset and progression of retinal diseases. This review examines the involvement of sphingolipids in retinal physiology and diseases. Ceramide (Cer) has emerged as a common mediator of inflammation and death of neuronal and retinal pigment epithelium cells in animal models of retinopathies such as glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa. Sphingosine-1-phosphate (S1P) has opposite roles, preventing photoreceptor and ganglion cell degeneration but also promoting inflammation, fibrosis, and neovascularization in AMD, glaucoma, and pro-fibrotic disorders. Alterations in Cer, S1P, and ceramide 1-phosphate may also contribute to uveitis. Notably, use of inhibitors that either prevent Cer increase or modulate S1P signaling, such as Myriocin, desipramine, and Fingolimod (FTY720), preserves neuronal viability and retinal function. These findings underscore the relevance of alterations in the sphingolipid metabolic network in the etiology of multiple retinopathies and highlight the potential of modulating their metabolism for the design of novel therapeutic approaches.
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Affiliation(s)
- M Victoria Simon
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
| | - Sandip K Basu
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bano Qaladize
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Richard Grambergs
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nora P Rotstein
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina.
| | - Nawajes Mandal
- Departments of Ophthalmology and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
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Mandal N, Grambergs R, Mondal K, Basu SK, Tahia F, Dagogo-Jack S. Role of ceramides in the pathogenesis of diabetes mellitus and its complications. J Diabetes Complications 2021; 35:107734. [PMID: 33268241 PMCID: PMC8663915 DOI: 10.1016/j.jdiacomp.2020.107734] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
Diabetes mellitus (DM) is a systemic metabolic disease that affects 463 million adults worldwide and is a leading cause of cardiovascular disease, blindness, nephropathy, peripheral neuropathy, and lower-limb amputation. Lipids have long been recognized as contributors to the pathogenesis and pathophysiology of DM and its complications, but recent discoveries have highlighted ceramides, a class of bioactive sphingolipids with cell signaling and second messenger capabilities, as particularly important contributors to insulin resistance and the underlying mechanisms of DM complications. Besides their association with insulin resistance and pathophysiology of type 2 diabetes, evidence is emerging that certain species of ceramides are mediators of cellular mechanisms involved in the initiation and progression of microvascular and macrovascular complications of DM. Advances in our understanding of these associations provide unique opportunities for exploring ceramide species as potential novel therapeutic targets and biomarkers. This review discusses the links between ceramides and the pathogenesis of DM and diabetic complications and identifies opportunities for novel discoveries and applications.
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Affiliation(s)
- Nawajes Mandal
- The University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN 38163, USA.; The University of Tennessee Health Science Center, Department of Anatomy and Neurobiology, Memphis, TN 38163, USA..
| | - Richard Grambergs
- The University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN 38163, USA
| | - Koushik Mondal
- The University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN 38163, USA
| | - Sandip K Basu
- The University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN 38163, USA
| | - Faiza Tahia
- The University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN 38163, USA.; The University of Tennessee Health Science Center, Department of Pharmaceutical Sciences, College of Pharmacy, Memphis, TN 38163, USA
| | - Sam Dagogo-Jack
- The University of Tennessee Health Science Center, Division of Endocrinology, Memphis, TN 38163, USA.; The University of Tennessee Health Science Center, Clinical Research Center, Memphis, TN 38163, USA..
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Busik JV. Lipid metabolism dysregulation in diabetic retinopathy. J Lipid Res 2021; 62:100017. [PMID: 33581416 PMCID: PMC7892987 DOI: 10.1194/jlr.tr120000981] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/15/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022] Open
Abstract
Lipid metabolic abnormalities have emerged as potential risk factors for the development and progression of diabetic complications, including diabetic retinopathy (DR). This review article provides an overview of the results of clinical trials evaluating the potential benefits of lipid-lowering drugs, such as fibrates, omega-3 fatty acids, and statins, for the prevention and treatment of DR. Although several clinical trials demonstrated that treatment with fibrates leads to improvement of DR, there is a dissociation between the protective effects of fibrates in the retina, and the intended blood lipid classes, including plasma triglycerides, total cholesterol, or HDL:LDL cholesterol ratio. Guided by these findings, plasma lipid and lipoprotein-independent mechanisms are addressed based on clinical, cell culture, and animal model studies. Potential retinal-specific effects of fatty acid oxidation products, cholesterol, and ceramide, as well as lipid-independent effects of PPAR alpha activation, are summarized based on the current literature. Overall, this review highlights promising potential of lipid-based treatment strategies further enhanced by the new knowledge of intraretinal lipids and lipoproteins in DR.
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Affiliation(s)
- Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
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Asare-Bediako B, Noothi SK, Li Calzi S, Athmanathan B, Vieira CP, Adu-Agyeiwaah Y, Dupont M, Jones BA, Wang XX, Chakraborty D, Levi M, Nagareddy PR, Grant MB. Characterizing the Retinal Phenotype in the High-Fat Diet and Western Diet Mouse Models of Prediabetes. Cells 2020; 9:cells9020464. [PMID: 32085589 PMCID: PMC7072836 DOI: 10.3390/cells9020464] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 02/08/2023] Open
Abstract
We sought to delineate the retinal features associated with the high-fat diet (HFD) mouse, a widely used model of obesity. C57BL/6 mice were fed either a high-fat (60% fat; HFD) or low-fat (10% fat; LFD) diet for up to 12 months. The effect of HFD on body weight and insulin resistance were measured. The retina was assessed by electroretinogram (ERG), fundus photography, permeability studies, and trypsin digests for enumeration of acellular capillaries. The HFD cohort experienced hypercholesterolemia when compared to the LFD cohort, but not hyperglycemia. HFD mice developed a higher body weight (60.33 g vs. 30.17g, p < 0.0001) as well as a reduced insulin sensitivity index (9.418 vs. 62.01, p = 0.0002) compared to LFD controls. At 6 months, retinal functional testing demonstrated a reduction in a-wave and b-wave amplitudes. At 12 months, mice on HFD showed evidence of increased retinal nerve infarcts and vascular leakage, reduced vascular density, but no increase in number of acellular capillaries compared to LFD mice. In conclusion, the HFD mouse is a useful model for examining the effect of prediabetes and hypercholesterolemia on the retina. The HFD-induced changes appear to occur slower than those observed in type 2 diabetes (T2D) models but are consistent with other retinopathy models, showing neural damage prior to vascular changes.
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Affiliation(s)
- Bright Asare-Bediako
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Sunil K. Noothi
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Sergio Li Calzi
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Baskaran Athmanathan
- Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.A.); (P.R.N.)
| | - Cristiano P. Vieira
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Yvonne Adu-Agyeiwaah
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Mariana Dupont
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Bryce A. Jones
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC 20057, USA;
| | - Xiaoxin X. Wang
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA; (X.X.W.); (M.L.)
| | - Dibyendu Chakraborty
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Moshe Levi
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA; (X.X.W.); (M.L.)
| | - Prabhakara R. Nagareddy
- Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.A.); (P.R.N.)
| | - Maria B. Grant
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
- Correspondence:
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Augustine J, Troendle EP, Barabas P, McAleese CA, Friedel T, Stitt AW, Curtis TM. The Role of Lipoxidation in the Pathogenesis of Diabetic Retinopathy. Front Endocrinol (Lausanne) 2020; 11:621938. [PMID: 33679605 PMCID: PMC7935543 DOI: 10.3389/fendo.2020.621938] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/21/2020] [Indexed: 12/31/2022] Open
Abstract
Lipids can undergo modification as a result of interaction with reactive oxygen species (ROS). For example, lipid peroxidation results in the production of a wide variety of highly reactive aldehyde species which can drive a range of disease-relevant responses in cells and tissues. Such lipid aldehydes react with nucleophilic groups on macromolecules including phospholipids, nucleic acids, and proteins which, in turn, leads to the formation of reversible or irreversible adducts known as advanced lipoxidation end products (ALEs). In the setting of diabetes, lipid peroxidation and ALE formation has been implicated in the pathogenesis of macro- and microvascular complications. As the most common diabetic complication, retinopathy is one of the leading causes of vision loss and blindness worldwide. Herein, we discuss diabetic retinopathy (DR) as a disease entity and review the current knowledge and experimental data supporting a role for lipid peroxidation and ALE formation in the onset and development of this condition. Potential therapeutic approaches to prevent lipid peroxidation and lipoxidation reactions in the diabetic retina are also considered, including the use of antioxidants, lipid aldehyde scavenging agents and pharmacological and gene therapy approaches for boosting endogenous aldehyde detoxification systems. It is concluded that further research in this area could lead to new strategies to halt the progression of DR before irreversible retinal damage and sight-threatening complications occur.
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Affiliation(s)
- Josy Augustine
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Evan P. Troendle
- Department of Chemistry, King’s College London, London, United Kingdom
| | - Peter Barabas
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Corey A. McAleese
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Thomas Friedel
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Alan W. Stitt
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
| | - Tim M. Curtis
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen’s University of Belfast, Belfast, United Kingdom
- *Correspondence: Tim M. Curtis,
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15
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Keurhorst D, Liashkovich I, Frontzek F, Nitzlaff S, Hofschröer V, Dreier R, Stock C. MMP3 activity rather than cortical stiffness determines NHE1-dependent invasiveness of melanoma cells. Cancer Cell Int 2019; 19:285. [PMID: 31728131 PMCID: PMC6842528 DOI: 10.1186/s12935-019-1015-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/01/2019] [Indexed: 12/31/2022] Open
Abstract
Background Both cell adhesion and matrix metalloproteinase (MMP) activity depend on pH at the cell surface. By regulating extracellular juxtamembrane pH, the Na+/H+ exchanger NHE1 plays a significant part in human melanoma (MV3) cell migration and invasion. Because NHE1, besides its pH-regulatory transport function, also serves as a structural element tying the cortical actin cytoskeleton to the plasma membrane, we investigated whether NHE1 affects cortical stiffness of MV3 cells, and how this makes an impact on their invasiveness. Methods NHE1 overexpressing MV3 cells were compared to the corresponding mock-transfected control cells. NHE1 expression was verified by Western blotting, cariporide (HOE642) was used to inhibit NHE1 activity, cell stiffness was determined by atomic force microscopy, and F-actin was visualized by phalloidin-staining. Migration on, and invasion of, native and glutaraldehyde-fixed collagen I substrates were analyzed using time-lapse video microscopy and Boyden-chamber assays, respectively. MMP secretion and activity were detected by Western blot and zymography, respectively. MMP activity was inhibited with NNGH. Results The cortical, but not the bulk stiffness, was significantly higher in NHE1 overexpressing cells. This increase in cortical stiffness was accompanied by a reorganization of the cortical cytoskeleton, i.e. a condensation of F-actin underneath and along the plasma membrane. However, it was not affected by NHE1 inhibition. Nevertheless, actin dynamics is required for cell invasion as demonstrated with the application of cytochalasin D. NHE1 overexpression was associated with an elevated MMP3 secretion and an increase in the invasion of a native matrix. This increase in invasiveness could be antagonized by the MMP inhibitor NNGH. Transmigration through a glutaraldehyde-fixed, indigestible substrate was not affected by NHE1 overexpression. Conclusion NHE1, as a structural element and independently of its transport activity, contributes to the organization of the cortical F-actin meshwork and thus impacts cortical stiffness. Since NHE1 overexpression stimulates MMP3 secretion but does not change transmigration through a fixed substrate, MV3 cell invasion of a native substrate depends on MMP activity rather than on a modifiable cortical stiffness.
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Affiliation(s)
- Dennis Keurhorst
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Ivan Liashkovich
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Fabian Frontzek
- 2Department of Oncology and Hematology, University Hospital of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Svenja Nitzlaff
- 3Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Verena Hofschröer
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Rita Dreier
- 4Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Waldeyer-Str. 15, 48149 Münster, Germany
| | - Christian Stock
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany.,5Department of Gastroenterology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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16
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Ji H, Yi Q, Chen L, Wong L, Liu Y, Xu G, Zhao J, Huang T, Li B, Yang Y, Li W, Han L, Duan S. Circulating miR-3197 and miR-2116-5p as novel biomarkers for diabetic retinopathy. Clin Chim Acta 2019; 501:147-153. [PMID: 31678272 DOI: 10.1016/j.cca.2019.10.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/21/2019] [Accepted: 10/24/2019] [Indexed: 12/13/2022]
Abstract
Diabetic retinopathy (DR) is the leading cause of vision loss among older adults. The goal of this case-control study was to identify circulating miRNAs for the diagnosis of DR. The miRNeasy Serum/Plasma Kit was used to extract serum miRNAs. The μParaflo™ MicroRNA microarray was used to detect the expression levels of the miRNAs. The miRWalk algorithm was applied to predict the target genes of the miRNAs, which were further confirmed by the dual luciferase reporter gene system in HEK293T cells. A microarray was performed between 5 DR cases and 5 age-, sex-, body mass index-, and duration of diabetes-matched type 2 diabetic (T2DM) controls. The quantitative reverse transcription polymerase chain reaction technique was used to validate the differentially expressed circulating miRNAs in 45 DR cases and 45 well-matched controls. Receiver operating characteristic (ROC) curve analysis was used to evaluate the performance of the circulating miRNAs as diagnostic biomarkers for DR. Our microarray analysis screened out miR-2116-5p and miR-3197 as significantly up-regulated in DR cases compared with the controls. Furthermore, two miRNAs were validated in the 45 DR cases and 45 controls. The ROC analysis suggested that both miR-3197 and miR-2116-5p distinguished DR cases from controls. An additional dual-luciferase reporter gene assay confirmed that notch homolog 2 (NOTCH2) was the target gene of miR-2116-5p. Both miR-3197 and miR-2116-5p were identified as promising diagnostic biomarkers for DR. Future research is still needed to explore the molecular mechanisms of miR-3197 and miR-2116-5p in the pathogenesis of DR.
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Affiliation(s)
- Huihui Ji
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China; Departmant of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Quanyong Yi
- Ningbo Eye Hospital, Minan Road 855, Ningbo, Zhejiang, China
| | - Lishuang Chen
- Ningbo Eye Hospital, Minan Road 855, Ningbo, Zhejiang, China
| | - Liping Wong
- Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yanfen Liu
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Guodong Xu
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Jun Zhao
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Tianyi Huang
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Bin Li
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Yong Yang
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Wenxia Li
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Liyuan Han
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China.
| | - Shiwei Duan
- Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China.
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Priya E, Jayashree K, Senthilkumar GP, Yasir M, Babu K R, Devi TD. Role of Fetuin-A and vascular endothelial growth factor In type 2 diabetes mellitus patients without and with retinopathy. Diabetes Metab Syndr 2019; 13:2699-2703. [PMID: 31405696 DOI: 10.1016/j.dsx.2019.07.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/10/2019] [Indexed: 01/29/2023]
Affiliation(s)
- Ezhumalai Priya
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
| | - Kuppuswami Jayashree
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
| | | | - Md Yasir
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
| | - Ramesh Babu K
- Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
| | - Thiyagarajan Durga Devi
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India
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18
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Simón MV, Prado Spalm FH, Vera MS, Rotstein NP. Sphingolipids as Emerging Mediators in Retina Degeneration. Front Cell Neurosci 2019; 13:246. [PMID: 31244608 PMCID: PMC6581011 DOI: 10.3389/fncel.2019.00246] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/17/2019] [Indexed: 12/12/2022] Open
Abstract
The sphingolipids ceramide (Cer), sphingosine-1-phosphate (S1P), sphingosine (Sph), and ceramide-1-phosphate (C1P) are key signaling molecules that regulate major cellular functions. Their roles in the retina have gained increasing attention during the last decade since they emerge as mediators of proliferation, survival, migration, neovascularization, inflammation and death in retina cells. As exacerbation of these processes is central to retina degenerative diseases, they appear as crucial players in their progression. This review analyzes the functions of these sphingolipids in retina cell types and their possible pathological roles. Cer appears as a key arbitrator in diverse retinal pathologies; it promotes inflammation in endothelial and retina pigment epithelium (RPE) cells and its increase is a common feature in photoreceptor death in vitro and in animal models of retina degeneration; noteworthy, inhibiting Cer synthesis preserves photoreceptor viability and functionality. In turn, S1P acts as a double edge sword in the retina. It is essential for retina development, promoting the survival of photoreceptors and ganglion cells and regulating proliferation and differentiation of photoreceptor progenitors. However, S1P has also deleterious effects, stimulating migration of Müller glial cells, angiogenesis and fibrosis, contributing to the inflammatory scenario of proliferative retinopathies and age related macular degeneration (AMD). C1P, as S1P, promotes photoreceptor survival and differentiation. Collectively, the expanding role for these sphingolipids in the regulation of critical processes in retina cell types and in their dysregulation in retina degenerations makes them attractive targets for treating these diseases.
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Affiliation(s)
- M Victoria Simón
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
| | - Facundo H Prado Spalm
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
| | - Marcela S Vera
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
| | - Nora P Rotstein
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento De Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Argentine National Research Council (CONICET), Bahía Blanca, Argentina
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19
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Inhibition of acid sphingomyelinase activity ameliorates endothelial dysfunction in db/db mice. Biosci Rep 2019; 39:BSR20182144. [PMID: 30910852 PMCID: PMC6481240 DOI: 10.1042/bsr20182144] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/19/2019] [Accepted: 03/15/2019] [Indexed: 12/25/2022] Open
Abstract
Acid sphingomyelinase (aSMase) plays an important role in endothelial dysfunction. Here, we show that elevated aSMase activity and ceramide content were reduced by desipramine treatment in diabetic animals. The inhibitor of aSMase, desipramine, improved vascular dysfunction in db/db mice. High glucose (HG)-induced up-regulation of aSMase activity and ceramide levels were restored by treatment with aSMase siRNA or desipramine in endothelial cells. In addition, aSMase siRNA or desipramine treatment increased the release of nitric oxide (NO) and the phosphorylation of endothelial NO synthase (eNOS) in diabetic mouse aortas and aortic endothelial cells with HG. These results indicate that inhibition of aSMase/ceramide pathway improves endothelium-dependent vascular relaxation (EDR) largely through regulating the eNOS/NO pathway in diabetic animals.
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20
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Inflammatory Ocular Diseases and Sphingolipid Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1159:139-152. [DOI: 10.1007/978-3-030-21162-2_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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21
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Hou L, Zheng Y, Wang Y, Hu Y, Shi J, Liu Q, Zhang H, Zhang Z. Self-Regulated Carboxyphenylboronic Acid-Modified Mesoporous Silica Nanoparticles with "Touch Switch" Releasing Property for Insulin Delivery. ACS APPLIED MATERIALS & INTERFACES 2018; 10:21927-21938. [PMID: 29932320 DOI: 10.1021/acsami.8b06998] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Glucose-responsive insulin delivery systems, which can maintain a stable level of blood glucose, have been proposed as a promising method to treat diabetes. Such systems can reduce potential toxicity and enhance patient compliance compared to traditional therapies. Accordingly, we designed a mesoporous silica nanoparticle (MSN)-based glucose-sensitive and self-regulated drug release system to achieve the goal of long circulation and "touch switch" in vivo. In this system, carboxyphenylboronic acid (CPBA) was first modified on the surface of MSN using amidation reaction. Insulin (INS) was then loaded in the channels of MSN (CPBA-MSN/INS) through physical adsorption, and sodium alginate (SA) was introduced onto the surface of the CPBA-MSN/INS nanoparticles as the gatekeeper via amidation reaction (SA/CPBA-MSN/INS). We found the drug loading capacity of INS was 261 mg/g. In the normal range of blood glucose, INS was scarcely released due to the reversible covalent interaction between 1,2-diols of SA and CPBA. Within the high concentration of glucose, the boronate esters could be dissociated, which results in the mesoporous channels opening and the release of INS. In vivo experiments on diabetic mice showed SA/CPBA-MSN/INS sustained a normal blood glucose level for up to 12 h with a single dose. Moreover, the lipid metabolism disorder and organ damage of diabetic mice were alleviated after treatment with SA/CPBA-MSN/INS. Therefore, SA/CPBA-MSN/INS characterized by an "on-off" regulated drug release property and high biosafety shows promise for applications in diabetes treatment.
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Affiliation(s)
- Lin Hou
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation , Zhengzhou 450001 , Henan Province , China
- Key Laboratory of Targeting and Diagnosis for Critical Diseases , Zhengzhou 450001 , Henan Province , China
| | - Yazhen Zheng
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
| | - Yongchao Wang
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
| | - Yurong Hu
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation , Zhengzhou 450001 , Henan Province , China
- Key Laboratory of Targeting and Diagnosis for Critical Diseases , Zhengzhou 450001 , Henan Province , China
| | - Jinjin Shi
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation , Zhengzhou 450001 , Henan Province , China
- Key Laboratory of Targeting and Diagnosis for Critical Diseases , Zhengzhou 450001 , Henan Province , China
| | - Qi Liu
- Division of Pharmacoengineering and Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Huijuan Zhang
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation , Zhengzhou 450001 , Henan Province , China
- Key Laboratory of Targeting and Diagnosis for Critical Diseases , Zhengzhou 450001 , Henan Province , China
| | - Zhenzhong Zhang
- School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou 450001 , China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation , Zhengzhou 450001 , Henan Province , China
- Key Laboratory of Targeting and Diagnosis for Critical Diseases , Zhengzhou 450001 , Henan Province , China
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22
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Kady NM, Liu X, Lydic TA, Syed MH, Navitskaya S, Wang Q, Hammer SS, O'Reilly S, Huang C, Seregin SS, Amalfitano A, Chiodo VA, Boye SL, Hauswirth WW, Antonetti DA, Busik JV. ELOVL4-Mediated Production of Very Long-Chain Ceramides Stabilizes Tight Junctions and Prevents Diabetes-Induced Retinal Vascular Permeability. Diabetes 2018; 67:769-781. [PMID: 29362226 PMCID: PMC5860862 DOI: 10.2337/db17-1034] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/08/2018] [Indexed: 12/25/2022]
Abstract
Tight junctions (TJs) involve close apposition of transmembrane proteins between cells. Although TJ proteins have been studied in detail, the role of lipids is largely unknown. We addressed the role of very long-chain (VLC ≥26) ceramides in TJs using diabetes-induced loss of the blood-retinal barrier as a model. VLC fatty acids that incorporate into VLC ceramides are produced by elongase elongation of very long-chain fatty acids protein 4 (ELOVL4). ELOVL4 is significantly reduced in the diabetic retina. Overexpression of ELOVL4 significantly decreased basal permeability, inhibited vascular endothelial growth factor (VEGF)- and interleukin-1β-induced permeability, and prevented VEGF-induced decrease in occludin expression and border staining of TJ proteins ZO-1 and claudin-5. Intravitreal delivery of AAV2-hELOVL4 reduced diabetes-induced increase in vascular permeability. Ultrastructure and lipidomic analysis revealed that ω-linked acyl-VLC ceramides colocalize with TJ complexes. Overall, normalization of retinal ELOVL4 expression could prevent blood-retinal barrier dysregulation in diabetic retinopathy through an increase in VLC ceramides and stabilization of TJs.
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Affiliation(s)
- Nermin M Kady
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Xuwen Liu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Todd A Lydic
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Meesum H Syed
- Department of Physiology, Michigan State University, East Lansing, MI
| | | | - Qi Wang
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sandra O'Reilly
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Chao Huang
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sergey S Seregin
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI
| | - Andrea Amalfitano
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI
| | - Vince A Chiodo
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - Sanford L Boye
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - William W Hauswirth
- Ophthalmology and Molecular Genetics and Retina Gene Therapy Group, University of Florida, Gainesville, FL
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI
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23
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Zhao Y, Geng X, Li Q, Jiang G, Gu Y, Lv X. Recognition of a Virtual Scene via Simulated Prosthetic Vision. Front Bioeng Biotechnol 2017; 5:58. [PMID: 29067286 PMCID: PMC5641342 DOI: 10.3389/fbioe.2017.00058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 09/20/2017] [Indexed: 11/24/2022] Open
Abstract
In order to effectively aid the blind with optimal low-resolution vision and visual recovery training, pathfinding and recognition tests were performed using a simulated visual prosthetic scene. Simple and complex virtual scenes were built using 3DMAX and Unity, and pixelated to three different resolutions (32 × 32, 64 × 64, and 128 × 128) for real-time pixel processing. Twenty subjects were recruited to complete the pathfinding and object recognition tasks within the scene. The recognition accuracy and time required were recorded and analyzed after the trials. In the simple simulated prosthetic vision (SPV) scene, when the resolution was increased from 32 × 32 to 48 × 48, the object recognition time decreased from 92.19 ± 6.97 to 43.05 ± 6.08 s, and the recognition accuracy increased from 51.22 ± 8.53 to 85.52 ± 4.93%. Furthermore, the number of collisions decreased from 10.00 ± 2.31 to 3.00 ± 0.68. When the resolution was increased from 48 × 48 to 64 × 64, the object recognition time further decreased from 43.05 ± 6.08 to 19.46 ± 3.71 s, the recognition accuracy increased from 85.52 ± 4.93 to 96.89 ± 2.06%, and the number of collisions decreased from 3.00 ± 0.68 to 1.00 ± 0.29. In complex scenes, the time required to recognize the room type decreased from 115.00 ± 23.02 to 68.25 ± 17.23 s, and object recognition accuracy increased from 65.69 ± 9.61 to 80.42 ± 7.70% when the resolution increased from 48 × 48 to 64 × 64. When the resolution increased from 64 × 64 to 128 × 128, the time required to recognize the room type decreased from 68.25 ± 17.23 to 44.88 ± 9.94 s, and object recognition accuracy increased from 80.42 ± 7.71 to 85.69 ± 7.39%. Therefore, one can conclude that there are correlations between pathfinding and recognition. When the resolution increased, the time required for recognition decreased, the recognition accuracy increased, and the number of collisions decreased. Although the subjects could partially complete the recognition task at a resolution of 32 × 32, the recognition time was too long and recognition accuracy was not good enough to identify simple scenes. Complex scenes required a resolution of at least 48 × 48 for complete recognition. In addition, increasing the resolution shortened the time required to identify the type of room, and improved the recognition accuracy.
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Affiliation(s)
- Ying Zhao
- School of Information Engineering, University of Science and Technology, Baotou, China
| | - Xiulin Geng
- School of Information Engineering, University of Science and Technology, Baotou, China
| | - Qi Li
- School of Information Engineering, University of Science and Technology, Baotou, China
| | - Guangqi Jiang
- School of Information Engineering, University of Science and Technology, Baotou, China
| | - Yu Gu
- School of Information Engineering, University of Science and Technology, Baotou, China
- School of Computer Engineering and Science, Shanghai University, Shanghai, China
| | - Xiaoqi Lv
- School of Information Engineering, University of Science and Technology, Baotou, China
- School of Computer Engineering and Science, Shanghai University, Shanghai, China
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24
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Hammer SS, Busik JV. The role of dyslipidemia in diabetic retinopathy. Vision Res 2017; 139:228-236. [PMID: 28545981 DOI: 10.1016/j.visres.2017.04.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/06/2017] [Accepted: 04/13/2017] [Indexed: 02/08/2023]
Abstract
Diabetic retinopathy (DR) affects over 93million people worldwide and is the number one cause of blindness among working age adults. These indicators coupled with the projected rise of patients diagnosed with diabetes, makes DR a serious and prevalent vision threating disease. Data from recent clinical trials demonstrate that in addition to the well accepted role of hyperglycemia, dyslipidemia is an important, but often overlooked factor in the development of DR. The central aim of this review article is to showcase the critical role of dyslipidemia in DR progression as well as highlight novel therapeutic solutions that take advantage of the vital roles lipid metabolism plays in DR progression.
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Affiliation(s)
- Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, United States.
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Kowluru RA, Mishra M, Kowluru A, Kumar B. Hyperlipidemia and the development of diabetic retinopathy: Comparison between type 1 and type 2 animal models. Metabolism 2016; 65:1570-81. [PMID: 27621192 PMCID: PMC5023070 DOI: 10.1016/j.metabol.2016.07.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/21/2016] [Accepted: 07/23/2016] [Indexed: 01/26/2023]
Abstract
AIM In the pathogenesis of diabetic retinopathy, reactive oxygen species (ROS) are elevated in the retina and the mitochondria are damaged, resulting in accelerated apoptosis. Dyslipidemia is also considered as one of the major factors in its development, and our aim is to investigate the compounding effect of hyperlipidemia in retinopathy. METHODS Retinal ROS, mitochondrial damage and vascular pathology were investigated in Zucker diabetic fatty rats (ZDF, type 2 diabetes model), during the age that spans from hyperlipidemia/pre-hyperglycemia (6weeks), to severe hyperglycemia/moderate hyperlipidemia (~12weeks), and ultimately to severe hyperglycemia/hyperlipidemia (20-40weeks). For comparison, retina from streptozotocin-induced Wistar rats (type 1 diabetic for 10-40weeks) was analyzed. RESULTS Compared to age-matched lean rats, despite increased retinal cytosolic ROS in 6-week-old ZDF rats, mitochondrial dysfunction and DNA damage were not detected, and in 12-week-old ZDF rats, retinal mitochondria were dysfunctional, but mtDNA damage and vascular pathology (cell apoptosis and degenerative capillaries) were not detectable. Retina from 20-week-old ZDF rats (hyperglycemic for 14weeks or less) had significant mitochondrial dysfunction, mtDNA damage and vascular pathology, and similar abnormalities were observed in 40-week-old ZDF rats. Although retinal mitochondrial dysfunction was observed in Wistar rats diabetic for 20weeks, mtDNA damage and vascular pathology were not detectable till the duration of diabetes was further extended. CONCLUSIONS Hyperlipidemia, in a hyperglycemic milieu, potentiates mitochondrial damage and augments the development of retinopathy. Control of dyslipidemia in pre-diabetic patients may prevent/delay the development and the progression of this devastating disease.
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Affiliation(s)
- Renu A Kowluru
- Ophthalmology, Wayne State University, Detroit, MI, United States.
| | - Manish Mishra
- Ophthalmology, Wayne State University, Detroit, MI, United States
| | - Anjaneyulu Kowluru
- Pharmaceutical Sciences, Wayne State University, Detroit, MI, United States; John D. Dingell VA Medical Center, Detroit, MI, United States
| | - Binit Kumar
- Ophthalmology, Wayne State University, Detroit, MI, United States
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Dual Anti-Inflammatory and Anti-Angiogenic Action of miR-15a in Diabetic Retinopathy. EBioMedicine 2016; 11:138-150. [PMID: 27531575 PMCID: PMC5049929 DOI: 10.1016/j.ebiom.2016.08.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/26/2016] [Accepted: 08/06/2016] [Indexed: 11/22/2022] Open
Abstract
Activation of pro-inflammatory and pro-angiogenic pathways in the retina and the bone marrow contributes to pathogenesis of diabetic retinopathy. We identified miR-15a as key regulator of both pro-inflammatory and pro-angiogenic pathways through direct binding and inhibition of the central enzyme in the sphingolipid metabolism, ASM, and the pro-angiogenic growth factor, VEGF-A. miR-15a was downregulated in diabetic retina and bone marrow cells. Over-expression of miR-15a downregulated, and inhibition of miR-15a upregulated ASM and VEGF-A expression in retinal cells. In addition to retinal effects, migration and retinal vascular repair function was impaired in miR-15a inhibitor-treated circulating angiogenic cells (CAC). Diabetic mice overexpressing miR-15a under Tie-2 promoter had normalized retinal permeability compared to wild type littermates. Importantly, miR-15a overexpression led to modulation toward nondiabetic levels, rather than complete inhibition of ASM and VEGF-A providing therapeutic effect without detrimental consequences of ASM and VEGF-A deficiencies.
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Chakravarthy H, Navitskaya S, O'Reilly S, Gallimore J, Mize H, Beli E, Wang Q, Kady N, Huang C, Blanchard GJ, Grant MB, Busik JV. Role of Acid Sphingomyelinase in Shifting the Balance Between Proinflammatory and Reparative Bone Marrow Cells in Diabetic Retinopathy. Stem Cells 2016; 34:972-83. [PMID: 26676316 DOI: 10.1002/stem.2259] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 10/31/2015] [Accepted: 11/12/2015] [Indexed: 12/20/2022]
Abstract
The metabolic insults associated with diabetes lead to low-grade chronic inflammation, retinal endothelial cell damage, and inadequate vascular repair. This is partly due to the increased activation of bone marrow (BM)-derived proinflammatory monocytes infiltrating the retina, and the compromised function of BM-derived reparative circulating angiogenic cells (CACs), which home to sites of endothelial injury and foster vascular repair. We now propose that a metabolic link leading to activated monocytes and dysfunctional CACs in diabetes involves upregulation of a central enzyme of sphingolipid signaling, acid sphingomyelinase (ASM). Selective inhibition of ASM in the BM prevented diabetes-induced activation of BM-derived microglia-like cells and normalized proinflammatory cytokine levels in the retina. ASM upregulation in diabetic CACs caused accumulation of ceramide on their cell membrane, thereby reducing membrane fluidity and impairing CAC migration. Replacing sphingomyelin with ceramide in synthetic membrane vesicles caused a similar decrease in membrane fluidity. Inhibition of ASM in diabetic CACs improved membrane fluidity and homing of these cells to damaged retinal vessels. Collectively, these findings indicate that selective modulation of sphingolipid metabolism in BM-derived cell populations in diabetes normalizes the reparative/proinflammatory cell balance and can be explored as a novel therapeutic strategy for treating diabetic retinopathy.
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Affiliation(s)
| | - Svetlana Navitskaya
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Sandra O'Reilly
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Jacob Gallimore
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Hannah Mize
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Eleni Beli
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Qi Wang
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Nermin Kady
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Chao Huang
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Gary J Blanchard
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Maria B Grant
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
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Abstract
The relationship between lipids and the development and/or severity of diabetic retinopathy (DR) is complex. Large epidemiologic studies suggest an inconsistent and overall modest association between serum triglycerides or major cholesterol species and the severity of DR; however, certain specific lipoprotein species may have stronger associations with DR severity, suggesting a pathophysiological role for lipoproteins analogous to that seen in atherosclerosis. In this lipoprotein-mediated DR pathogenesis model, damage to the blood-retinal barrier allows extravasation of lipoprotein species, which are modified in the intraretinal environment, creating substantial local damage. Additionally, hypolipidemic therapy with statins and fibrates--particularly the latter--have been shown to modulate DR in large-scale studies. Since serum lipid profile changes do not necessarily correlate with DR modulation, the efficacy of these agents may be due to their tissue-specific changes in lipoproteins and/or their anti-inflammatory, antioxidative, antiangiogenic, and antiapoptotic functions.
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Affiliation(s)
- Bobeck S Modjtahedi
- a Retina Service, Department of Ophthalmology , Massachusetts Eye and Ear Infirmary , Boston , Massachusetts , USA
| | - Namrata Bose
- b Department of Endocrinology , Keck School of Medicine, University of Southern California , Los Angeles , California , USA
| | - Thanos D Papakostas
- a Retina Service, Department of Ophthalmology , Massachusetts Eye and Ear Infirmary , Boston , Massachusetts , USA
| | - Lawrence Morse
- c Department of Ophthalmology and Vision Science , School of Medicine, University of California , Davis , Davis , California , USA , and
| | - Demetrios G Vavvas
- a Retina Service, Department of Ophthalmology , Massachusetts Eye and Ear Infirmary , Boston , Massachusetts , USA
| | - Amar U Kishan
- d Harvard Medical School , Boston , Massachusetts , USA
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Nuclear receptor RORα regulates pathologic retinal angiogenesis by modulating SOCS3-dependent inflammation. Proc Natl Acad Sci U S A 2015; 112:10401-6. [PMID: 26243880 DOI: 10.1073/pnas.1504387112] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Pathologic ocular angiogenesis is a leading cause of blindness, influenced by both dysregulated lipid metabolism and inflammation. Retinoic-acid-receptor-related orphan receptor alpha (RORα) is a lipid-sensing nuclear receptor with diverse biologic function including regulation of lipid metabolism and inflammation; however, its role in pathologic retinal angiogenesis remains poorly understood. Using a mouse model of oxygen-induced proliferative retinopathy, we showed that RORα expression was significantly increased and genetic deficiency of RORα substantially suppressed pathologic retinal neovascularization. Loss of RORα led to decreased levels of proinflammatory cytokines and increased levels of antiinflammatory cytokines in retinopathy. RORα directly suppressed the gene transcription of suppressors of cytokine signaling 3 (SOCS3), a critical negative regulator of inflammation. Inhibition of SOCS3 abolished the antiinflammatory and vasoprotective effects of RORα deficiency in vitro and in vivo. Moreover, treatment with a RORα inverse agonist SR1001 effectively protected against pathologic neovascularization in both oxygen-induced retinopathy and another angiogenic model of very-low-density lipoprotein receptor (Vldlr)-deficient (Vldlr (-/-) ) mice with spontaneous subretinal neovascularization, whereas a RORα agonist worsened oxygen-induced retinopathy. Our data demonstrate that RORα is a novel regulator of pathologic retinal neovascularization, and RORα inhibition may represent a new way to treat ocular neovascularization.
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Yan F, Tian L, Xiao Z, Li S, Fu M, Tian H. Comparison of the efficacy of fenofibrate and acipimox on plasma lipoprotein subclasses distribution in the Chinese population with Type 2 diabetes mellitus and hypertriglyceridemia. CLINICAL LIPIDOLOGY 2014. [DOI: 10.2217/clp.14.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Fangfang Yan
- Department of Endocrinology & Metabolism, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, People’s Republic of China
| | - Li Tian
- Department of Endocrinology & Metabolism, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, People’s Republic of China
| | - Zhu Xiao
- Chengdu First People’s Hospital, Chengdu 610041, Sichuan, People’s Republic of China
| | - Sheyu Li
- Department of Endocrinology & Metabolism, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, People’s Republic of China
| | - Mingde Fu
- Department of Endocrinology & Metabolism, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, People’s Republic of China
| | - Haoming Tian
- Department of Endocrinology & Metabolism, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, People’s Republic of China
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Gilbertson TA, Khan NA. Cell signaling mechanisms of oro-gustatory detection of dietary fat: advances and challenges. Prog Lipid Res 2013; 53:82-92. [PMID: 24269201 DOI: 10.1016/j.plipres.2013.11.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/08/2013] [Indexed: 01/19/2023]
Abstract
CD36 and two G-protein coupled receptors (GPCR), i.e., GPR120 and GPR40, have been implicated in the gustatory perception of dietary fats in rodents. These glycoproteins are coupled to increases in free intracellular Ca²⁺ concentrations, [Ca²⁺](i), during their activation by dietary long-chain fatty acids (LCFA). The transient receptor potential type M5 (TRPM5) channel, activated by [Ca²⁺](i), participates in downstream signaling in taste bud cells (TBC). The mice, knocked-out for expression of CD36, GPR120, GPR40 or TRPM5 have a reduced spontaneous preference for fat. The delayed rectifying K⁺ (DRK) channels believed to lie downstream of these receptors are also important players in fat taste transduction. The trigeminal neurons by triggering increases in [Ca²⁺](i) may influence the taste signal to afferent nerve fibers. Why are there so many taste receptor candidates for one taste modality? We discuss the recent advances on the role of CD36, GPR120, GPR40, TRPM5 and DRK channels, in signal transduction in TBC. We shed light on their cross-talk and delineate their roles in obesity as a better understanding of the molecular mechanisms behind their regulation could eventually lead to new strategies to fight against this condition.
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Affiliation(s)
- Timothy A Gilbertson
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA
| | - Naim A Khan
- INSERM U866, Université de Bourgogne/AgroSup, Dijon 2100, France.
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Abstract
Chronic hyperglycemia (HG)-associated reactive oxygen/nitrogen species (ROS/RNS) stress and low grade inflammation are considered to play critical roles in the development of diabetic retinopathy (DR). Excess glucose metabolic flux through the aldose reductase/polyol pathway, advanced glycation end product (AGE) formation, elevated hexosamine biosynthesis pathway (HBP), diacyl glycerol/PKC activation, and mitochondrial ROS generation are all implicated in DR. In addition, endoplasmic reticulum stress/unfolded protein response (er-UPR) and deregulation of mitochondrial quality control by autophagy/mitophagy are observed causing cellular bioenergetic deficiency and injury. Recently, a pro-oxidant and pro-apoptotic thioredoxin interacting protein (TXNIP) was shown to be highly upregulated in DR and by HG in retinal cells in culture. TXNIP binds to thioredoxin (Trx) inhibiting its oxidant scavenging and thiolreducing capacity. Hence, prolonged overexpression of TXNIP causes ROS/RNS stress, mitochondrial dysfunction, inflammation and premature cell death in DR. Initially, DR was considered as microvascular complications of endothelial dysfunction and pericyte loss characterized by capillary basement membrane thickening, pericyte ghost, blood retinal barrier leakage, acellular capillary and neovascularization. However, it is currently acknowledged that neuro-glia are also affected by HG in diabetes and that neuronal injury, glial activation, innate immunity/sterile inflammation, and ganglion apoptosis occur early in DR. In addition, retinal pigment epithelium (RPE) becomes dysfunctional in DR. Since TXNIP is induced by HG in most cells, its effects are not restricted to a particular cell type in DR. However, depending on the metabolic activity and anti-oxidant capacity, some cells may be affected earlier by TXNIP than others. Identification of TXNIP sensitive cells and elucidating the underlying mechanism(s) will be critical for preventing pre-mature cell death and progression of DR.
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Affiliation(s)
- Lalit P Singh
- Departments of Anatomy and Cell Biology and Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Abstract
Clinical epidemiological studies have revealed relatively weak, yet statistically significant, associations between dyslipidemia/dyslipoproteinemia and diabetic retinopathy (DR). Recent large interventional studies, however, demonstrated an unexpectedly robust efficacy of fenofibrate on the development of DR, possibly independent of plasma lipids. To unify the apparent discrepancies, we hypothesize that plasma lipoproteins play an indirect but important role in DR, contingent on the integrity of the blood-retina-barrier (BRB). In retinas with an intact BRB, plasma lipoproteins may be largely irrelevant; however, important effects become operative after the BRB is impaired in diabetes, leading to lipoprotein extravasation and subsequent modification, hence toxicity to the neighbouring retinal cells. In this hypothesis, BRB leakage is the key, plasma lipoprotein concentrations mainly modulate its consequences, and fenofibrate has intra-retinal actions. This review summarizes our current knowledge of the direct effects and mechanisms of modified lipoproteins on retinal cells and their potential contribution to the pathogenesis of DR.
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Affiliation(s)
- Jeremy Y Yu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK
| | - Timothy J Lyons
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK ; Harold Hamm Diabetes Center and Section of Endocrinology and Diabetes, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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