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Tsikandelova R, Galo E, Cerniauskas E, Hallam D, Georgiou M, Cerna-Chavez R, Atkinson R, Palmowski P, Burté F, Davies T, Steel DH, McKibbin M, Bond J, Haggarty J, Whitfield P, Korolchuk V, Armstrong L, Yang C, Dorgau B, Kurzawa-Akanbi M, Lako M. Retinal cells derived from patients with DRAM2-dependent CORD21 dystrophy exhibit key lysosomal enzyme deficiency and lysosomal content accumulation. Stem Cell Reports 2024; 19:1107-1121. [PMID: 38964324 DOI: 10.1016/j.stemcr.2024.06.002] [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: 04/04/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 07/06/2024] Open
Abstract
Biallelic mutations in DRAM2 lead to an autosomal recessive cone-rod dystrophy known as CORD21, which typically presents between the third and sixth decades of life. Although DRAM2 localizes to the lysosomes of photoreceptor and retinal pigment epithelium (RPE) cells, its specific role in retinal degeneration has not been fully elucidated. In this study, we generated and characterized retinal organoids (ROs) and RPE cells from induced pluripotent stem cells (iPSCs) derived from two CORD21 patients. Our investigation revealed that CORD21-ROs and RPE cells exhibit abnormalities in lipid metabolism, defects in autophagic flux, accumulation of aberrant lysosomal content, and reduced lysosomal enzyme activity. We identified potential interactions of DRAM2 with vesicular trafficking proteins, suggesting its involvement in this cellular process. These findings collectively suggest that DRAM2 plays a crucial role in maintaining the integrity of photoreceptors and RPE cells by regulating lysosomal function, autophagy, and potentially vesicular trafficking.
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Affiliation(s)
| | - Eldo Galo
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | - Dean Hallam
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Maria Georgiou
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | | | | | - Florence Burté
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Tracey Davies
- Electron Microscopy Research Services, Newcastle University, Newcastle, UK
| | - David H Steel
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Martin McKibbin
- Leeds Teaching Hospitals NHS Trust, Leeds UK and Leeds Institute for Medical Research, St. James's University Hospital, University of Leeds, Leeds, UK
| | - Jacquelyn Bond
- Leeds Teaching Hospitals NHS Trust, Leeds UK and Leeds Institute for Medical Research, St. James's University Hospital, University of Leeds, Leeds, UK
| | - Jennifer Haggarty
- Shared Research Facilities, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Phil Whitfield
- Glasgow Polyomics and Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | - Lyle Armstrong
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Chunbo Yang
- Biosciences Institute, Newcastle University, Newcastle, UK
| | - Birthe Dorgau
- Biosciences Institute, Newcastle University, Newcastle, UK
| | | | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle, UK.
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2
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He M, Hou G, Liu M, Peng Z, Guo H, Wang Y, Sui J, Liu H, Yin X, Zhang M, Chen Z, Rensen PCN, Lin L, Wang Y, Shi B. Lipidomic studies revealing serological markers associated with the occurrence of retinopathy in type 2 diabetes. J Transl Med 2024; 22:448. [PMID: 38741137 DOI: 10.1186/s12967-024-05274-9] [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: 08/21/2023] [Accepted: 05/04/2024] [Indexed: 05/16/2024] Open
Abstract
PURPOSE The duration of type 2 diabetes mellitus (T2DM) and blood glucose levels have a significant impact on the development of T2DM complications. However, currently known risk factors are not good predictors of the onset or progression of diabetic retinopathy (DR). Therefore, we aimed to investigate the differences in the serum lipid composition in patients with T2DM, without and with DR, and search for potential serological indicators associated with the development of DR. METHODS A total of 622 patients with T2DM hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Xi'an JiaoTong University were selected as the discovery set. One-to-one case-control matching was performed according to the traditional risk factors for DR (i.e., age, duration of diabetes, HbA1c level, and hypertension). All cases with comorbid chronic kidney disease were excluded to eliminate confounding factors. A total of 42 pairs were successfully matched. T2DM patients with DR (DR group) were the case group, and T2DM patients without DR (NDR group) served as control subjects. Ultra-performance liquid chromatography-mass spectrometry (LC-MS/MS) was used for untargeted lipidomics analysis on serum, and a partial least squares discriminant analysis (PLS-DA) model was established to screen differential lipid molecules based on variable importance in the projection (VIP) > 1. An additional 531 T2DM patients were selected as the validation set. Next, 1:1 propensity score matching (PSM) was performed for the traditional risk factors for DR, and a combined 95 pairings in the NDR and DR groups were successfully matched. The screened differential lipid molecules were validated by multiple reaction monitoring (MRM) quantification based on mass spectrometry. RESULTS The discovery set showed no differences in traditional risk factors associated with the development of DR (i.e., age, disease duration, HbA1c, blood pressure, and glomerular filtration rate). In the DR group compared with the NDR group, the levels of three ceramides (Cer) and seven sphingomyelins (SM) were significantly lower, and one phosphatidylcholine (PC), two lysophosphatidylcholines (LPC), and two SMs were significantly higher. Furthermore, evaluation of these 15 differential lipid molecules in the validation sample set showed that three Cer and SM(d18:1/24:1) molecules were substantially lower in the DR group. After excluding other confounding factors (e.g., sex, BMI, lipid-lowering drug therapy, and lipid levels), multifactorial logistic regression analysis revealed that a lower abundance of two ceramides, i.e., Cer(d18:0/22:0) and Cer(d18:0/24:0), was an independent risk factor for the occurrence of DR in T2DM patients. CONCLUSION Disturbances in lipid metabolism are closely associated with the occurrence of DR in patients with T2DM, especially in ceramides. Our study revealed for the first time that Cer(d18:0/22:0) and Cer(d18:0/24:0) might be potential serological markers for the diagnosis of DR occurrence in T2DM patients, providing new ideas for the early diagnosis of DR.
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Affiliation(s)
- Mingqian He
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Guixue Hou
- BGI-SHENZHEN, No. 21 Hongan 3rd Street, Yantian District, Shenzhen, Guangdong, 518083, P.R. China
| | - Mengmeng Liu
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Zhaoyi Peng
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Hui Guo
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Yue Wang
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Jing Sui
- Department of Endocrinology and International Medical Center, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Hui Liu
- Biobank, The First Affiliated Hospital of Xi'an JiaoTong University, Xi'an, Shaanxi, 710061, China
| | - Xiaoming Yin
- Chengdu HuiXin Life Technology, Chengdu, Sichuan, 610091, P.R. China
| | - Meng Zhang
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Ziyi Chen
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
| | - Patrick C N Rensen
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, P.O. Box 9600, Leiden, 2300 RA, The Netherlands
| | - Liang Lin
- BGI-SHENZHEN, No. 21 Hongan 3rd Street, Yantian District, Shenzhen, Guangdong, 518083, P.R. China.
- , Building NO.7, BGI Park, No. 21 Hongan 3rd Street, Yantian District, Shenzhen, Guangdong, 518083, P.R. China.
| | - Yanan Wang
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China.
- Med-X institute, Center for Immunological and Metabolic Diseases, the First Affiliated Hospital of Xi'an JiaoTong University, Xi'an JiaoTong university, Xi'an, Shaanxi, 710061, P.R. China.
| | - Bingyin Shi
- Department of Endocrinology, the First Affiliated Hospital of Xi'an JiaoTong University, No.277, West Yanta Road, Xi'an, Shaanxi, 710061, P.R. China.
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Sun WJ, An XD, Zhang YH, Zhao XF, Sun YT, Yang CQ, Kang XM, Jiang LL, Ji HY, Lian FM. The ideal treatment timing for diabetic retinopathy: the molecular pathological mechanisms underlying early-stage diabetic retinopathy are a matter of concern. Front Endocrinol (Lausanne) 2023; 14:1270145. [PMID: 38027131 PMCID: PMC10680169 DOI: 10.3389/fendo.2023.1270145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Diabetic retinopathy (DR) is a prevalent complication of diabetes, significantly impacting patients' quality of life due to vision loss. No pharmacological therapies are currently approved for DR, excepted the drugs to treat diabetic macular edema such as the anti-VEGF agents or steroids administered by intraocular route. Advancements in research have highlighted the crucial role of early intervention in DR for halting or delaying disease progression. This holds immense significance in enhancing patients' quality of life and alleviating the societal burden associated with medical care costs. The non-proliferative stage represents the early phase of DR. In comparison to the proliferative stage, pathological changes primarily manifest as microangiomas and hemorrhages, while at the cellular level, there is a loss of pericytes, neuronal cell death, and disruption of components and functionality within the retinal neuronal vascular unit encompassing pericytes and neurons. Both neurodegenerative and microvascular abnormalities manifest in the early stages of DR. Therefore, our focus lies on the non-proliferative stage of DR and we have initially summarized the mechanisms involved in its development, including pathways such as polyols, that revolve around the pathological changes occurring during this early stage. We also integrate cutting-edge mechanisms, including leukocyte adhesion, neutrophil extracellular traps, multiple RNA regulation, microorganisms, cell death (ferroptosis and pyroptosis), and other related mechanisms. The current status of drug therapy for early-stage DR is also discussed to provide insights for the development of pharmaceutical interventions targeting the early treatment of DR.
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Affiliation(s)
- Wen-Jie Sun
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Xue-Dong An
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Yue-Hong Zhang
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Xue-Fei Zhao
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Yu-Ting Sun
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Cun-Qing Yang
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiao-Min Kang
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Lin-Lin Jiang
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Beijing University of Chinese Medicine, Beijing, China
| | - Hang-Yu Ji
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Feng-Mei Lian
- Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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Hypoxia-induced transcriptional differences in African and Asian versus European diabetic cybrids. Sci Rep 2023; 13:3818. [PMID: 36882486 PMCID: PMC9992459 DOI: 10.1038/s41598-023-30518-x] [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: 07/22/2022] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
Diabetic retinopathy (DR) is the most common diabetic microvascular complication and cause of blindness in adults under the age of 65. Our results suggest that, when comparing transcriptomes of cultures grown in hypoxic conditions versus room-air, cybrids containing mitochondria from African and Asian diabetic subjects ([Afr + Asi]/DM) have some uniquely different transcriptome profiles compared to European/diabetic (Euro/DM) cybrids (e.g., fatty acid metabolism: EnrichR rank 10 in [Afr + Asi]/DM, rank 85 in Euro/DM; Endocytosis: rank 25 in [Afr + Asi]/DM, rank 5 in Euro/DM; Ubiquitin Mediated Proteolysis: rank 34 in [Afr + Asi]/DM, rank 7 in Euro/DM). As determined by both RNA-seq and qRT-PCR results, transcription of the gene encoding oleoyl-ACP hydrolase (OLAH) was significantly increased in [Afr + Asi]/DM cybrids compared to Euro/DM cybrids in hypoxic conditions. Additionally, our results show that in hypoxic conditions, Euro/DM cybrids and [Afr + Asi]/DM cybrids show similar decreases in ROS production. All cybrids showed decreased ZO1-minus protein levels, but their phagocytic functions were not significantly altered in hypoxic conditions. In conclusion, our findings suggest that the "molecular memory" imparted by [Afr + Asi]/DM mtDNA may act through one of the molecular pathways seen in transcriptome analysis, such as fatty acid metabolism, without significantly changing essential RPE functions.
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5
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Vasku G, Peltier C, He Z, Thuret G, Gain P, Gabrielle PH, Acar N, Berdeaux O. Comprehensive mass spectrometry lipidomics of human biofluids and ocular tissues. J Lipid Res 2023; 64:100343. [PMID: 36773847 PMCID: PMC10027555 DOI: 10.1016/j.jlr.2023.100343] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/25/2023] [Accepted: 01/28/2023] [Indexed: 02/12/2023] Open
Abstract
Evaluating lipid profiles in human tissues and biofluids is critical in identifying lipid metabolites in dysregulated metabolic pathways. Due to various chemical characteristics, single-run lipid analysis has not yet been documented. Such approach is essential for analyzing pathology-related lipid metabolites. Age-related macular degeneration, the leading cause of vision loss in western countries, is emblematic of this limitation. Several studies have identified alterations in individual lipids but the majority are based on targeted approaches. In this study, we analyzed and identified approximately 500 lipid species in human biofluids (plasma and erythrocytes) and ocular tissues (retina and retinal pigment epithelium) using the complementarity of hydrophilic interaction liquid chromatography (HILIC) and reversed-phase chromatography (RPC), coupled to high-resolution mass spectrometry. For that, lipids were extracted from human eye globes and blood from 10 subjects and lipidomic analysis was carried out through analysis in HILIC and RPC, alternately. Furthermore, we illustrate the advantages and disadvantages of both techniques for lipid characterization. RPC showed greater sensitivity in hydrophobicity-based lipid separation, detecting diglycerides, triglycerides, cholesterol, and cholesteryl esters, whereas no signal of these molecules was obtained in HILIC. However, due to coelution, RPC was less effective in separating polar lipids like phospholipids, which were separated effectively in HILIC in both ionization modes. The complementary nature of these analytical approaches was essential for the detection and identification of lipid classes/subclasses, which can then provide distinct insights into lipid metabolism, a determinant of the pathophysiology of several diseases involving lipids, notably age-related macular degeneration.
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Affiliation(s)
- Glenda Vasku
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne Franche-Comté, Dijon, France; ChemoSens Platform, Centre des Sciences du Goût et de l'Alimentation, Institut Agro, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France; INRAE, PROBE Research infrastructure, ChemoSens facility, Dijon, France
| | - Caroline Peltier
- ChemoSens Platform, Centre des Sciences du Goût et de l'Alimentation, Institut Agro, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France; INRAE, PROBE Research infrastructure, ChemoSens facility, Dijon, France
| | - Zhiguo He
- Department of Ophthalmology, Biology, Imaging, and Engineering of Corneal Grafts, Faculty of Medicine, Saint Etienne, France
| | - Gilles Thuret
- Department of Ophthalmology, Biology, Imaging, and Engineering of Corneal Grafts, Faculty of Medicine, Saint Etienne, France
| | - Philippe Gain
- Department of Ophthalmology, Biology, Imaging, and Engineering of Corneal Grafts, Faculty of Medicine, Saint Etienne, France
| | - Pierre-Henry Gabrielle
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne Franche-Comté, Dijon, France; Department of Ophthalmology, University Hospital, Dijon, France
| | - Niyazi Acar
- Eye and Nutrition Research Group, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne Franche-Comté, Dijon, France
| | - Olivier Berdeaux
- ChemoSens Platform, Centre des Sciences du Goût et de l'Alimentation, Institut Agro, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France; INRAE, PROBE Research infrastructure, ChemoSens facility, Dijon, France.
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Wu Y, Zou H. Research Progress on Mitochondrial Dysfunction in Diabetic Retinopathy. Antioxidants (Basel) 2022; 11:2250. [PMID: 36421435 PMCID: PMC9686704 DOI: 10.3390/antiox11112250] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/07/2022] [Accepted: 11/12/2022] [Indexed: 09/07/2023] Open
Abstract
Diabetic Retinopathy (DR) is one of the most important microvascular complications of diabetes mellitus, which can lead to blindness in severe cases. Mitochondria are energy-producing organelles in eukaryotic cells, which participate in metabolism and signal transduction, and regulate cell growth, differentiation, aging, and death. Metabolic changes of retinal cells and epigenetic changes of mitochondria-related genes under high glucose can lead to mitochondrial dysfunction and induce mitochondrial pathway apoptosis. In addition, mitophagy and mitochondrial dynamics also change adaptively. These mechanisms may be related to the occurrence and progression of DR, and also provide valuable clues for the prevention and treatment of DR. This article reviews the mechanism of DR induced by mitochondrial dysfunction, and the prospects for related treatment.
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Affiliation(s)
- Yiwei Wu
- Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
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7
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A Comprehensive Profiling of Cellular Sphingolipids in Mammalian Endothelial and Microglial Cells Cultured in Normal and High-Glucose Conditions. Cells 2022; 11:cells11193082. [PMID: 36231042 PMCID: PMC9563724 DOI: 10.3390/cells11193082] [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: 07/19/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
Sphingolipids (SPLs) play a diverse role in maintaining cellular homeostasis. Dysregulated SPL metabolism is associated with pathological changes in stressed and diseased cells. This study investigates differences in SPL metabolism between cultured human primary retinal endothelial (HREC) and murine microglial cells (BV2) in normal conditions (normal glucose, NG, 5 mM) and under high-glucose (HG, 25 mM)-induced stress by sphingolipidomics, immunohistochemistry, biochemical, and molecular assays. Measurable differences were observed in SPL profiles between HREC and BV2 cells. High-glucose treatment caused a >2.5-fold increase in the levels of Lactosyl-ceramide (LacCer) in HREC, but in BV2 cells, it induced Hexosyl-Ceramides (HexCer) by threefold and a significant increase in Sphingosine-1-phosphate (S1P) compared to NG. Altered SPL profiles coincided with changes in transcript levels of inflammatory and vascular permeability mediators in HREC and inflammatory mediators in BV2 cells. Differences in SPL profiles and differential responses to HG stress between endothelial and microglial cells suggest that SPL metabolism and signaling differ in mammalian cell types and, therefore, their pathological association with those cell types.
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Wu J, Hu J, Zhang F, Jin Q, Sun X. High glucose promotes IL-17A-induced gene expression through histone acetylation in retinal pigment epithelium cells. Int Immunopharmacol 2022; 110:108893. [DOI: 10.1016/j.intimp.2022.108893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/13/2022] [Accepted: 05/23/2022] [Indexed: 11/05/2022]
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9
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Hwang JS, Shin YJ. Role of Choline in Ocular Diseases. Int J Mol Sci 2021; 22:4733. [PMID: 33946979 PMCID: PMC8124599 DOI: 10.3390/ijms22094733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/25/2021] [Accepted: 04/28/2021] [Indexed: 12/29/2022] Open
Abstract
Choline is essential for maintaining the structure and function of cells in humans. Choline plays an important role in eye health and disease. It is a precursor of acetylcholine, a neurotransmitter of the parasympathetic nervous system, and it is involved in the production and secretion of tears by the lacrimal glands. It also contributes to the stability of the cells and tears on the ocular surface and is involved in retinal development and differentiation. Choline deficiency is associated with retinal hemorrhage, glaucoma, and dry eye syndrome. Choline supplementation may be effective for treating these diseases.
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Affiliation(s)
| | - Young-Joo Shin
- Department of Ophthalmology, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07442, Korea;
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10
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Frantz NL, Brakoniecki G, Chen D, Proshlyakov DA. Assessment of the Maximal Activity of Complex IV in the Inner Mitochondrial Membrane by Tandem Electrochemistry and Respirometry. Anal Chem 2021; 93:1360-1368. [PMID: 33319559 PMCID: PMC8772154 DOI: 10.1021/acs.analchem.0c02910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Assessment of activities of mitochondrial electron transport enzymes is important for understanding mechanisms of metabolic diseases, but structural organization of mitochondria and low sample availability pose distinctive challenges for in situ functional studies. We report the development of a tandem microfluidic respirometer that simultaneously tracks both the reduction of mediators on the electrode and the ensuing reduction of O2 by complex IV in the inner mitochondrial membrane. The response time of O2 consumption to multiple alternating potential steps is of approximately 10 s for a 150 μm-thick sample. Steady O2 depletion shows good quantitative correlation with the supplied electric charge, Pearson's r = 0.994. Reduction of mediators on biocompatible gold electrodes modified with carbon ink or fumed silica can compete with the oxidation of mediators by mitochondria, yielding an overall respiratory activity comparable to that upon chemical reduction by ascorbate. The dependence of O2 consumption on mediator and mitochondrial suspension concentrations shows that mass transport between the electrode and mitochondria does not limit biological activity of the latter. The mediated electrochemical approach is validated by the radiometric measurements of simulated changes in the intrinsic mitochondrial activity upon partial inhibition of complex IV by NaN3. This approach enables the development of O2-independent, biomimetic electrochemical assays narrowly targeting components of the electron transport chains in their native environments.
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Affiliation(s)
- Nathan L Frantz
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
| | - Gabrielle Brakoniecki
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
| | - Dawei Chen
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
| | - Denis A Proshlyakov
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States
- Department of Physiology, Michigan State University, 567 Wilson Rd, East Lansing, Michigan 48824-6405, United States
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11
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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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