1
|
Elzehery R, El-Hafez HA, Elsehely I, Barakat A, Foda EAE, Hendawy SR, Gameil MA, Nada HS, El-Sebaie A. Association of the E23K (rs5219) polymorphism in the potassium channel (KCNJ11) gene with diabetic neuropathy in type 2 diabetes. Gene 2024; 921:148525. [PMID: 38703869 DOI: 10.1016/j.gene.2024.148525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 04/14/2024] [Accepted: 05/01/2024] [Indexed: 05/06/2024]
Affiliation(s)
- Rasha Elzehery
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Hala Abd El-Hafez
- Internal Medicine Department, Endocrinology Unit, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Ibrahim Elsehely
- Internal Medicine Department, Endocrinology Unit, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Amira Barakat
- Internal Medicine Department, Endocrinology Unit, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Engy Ahmed Ebrahim Foda
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Shimaa Rabea Hendawy
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Mohammed Ali Gameil
- Internal Medicine Department, Endocrinology Unit, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Hyam Sameh Nada
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| | - Ahmed El-Sebaie
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Dakahlia, Egypt.
| |
Collapse
|
2
|
Preiss D, Logue J, Sammons E, Zayed M, Emberson J, Wade R, Wallendszus K, Stevens W, Cretney R, Harding S, Leese G, Currie G, Armitage J. Effect of Fenofibrate on Progression of Diabetic Retinopathy. NEJM EVIDENCE 2024:EVIDoa2400179. [PMID: 38905569 DOI: 10.1056/evidoa2400179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2024]
Abstract
BACKGROUND Findings from cardiovascular outcome trials suggest that fenofibrate therapy may reduce the progression of diabetic retinopathy. METHODS We recruited and followed adults with nonreferable diabetic retinopathy or maculopathy using the national Diabetic Eye Screening (DES) program in Scotland. We randomly assigned participants to receive 145-mg fenofibrate tablets or placebo (taken daily or, in those with impaired renal function, on alternate days). The primary outcome was a composite of developing referable diabetic retinopathy or maculopathy (based on Scotland's DES grading scheme) or treatment (intravitreal injection, retinal laser, vitrectomy) for retinopathy or maculopathy. RESULTS A total of 1151 participants were randomly assigned to treatment. During a median of 4.0 years, progression to referable diabetic retinopathy or maculopathy, or treatment thereof, occurred in 131 (22.7%) of 576 participants in the fenofibrate group and 168 (29.2%) of 575 in the placebo group (hazard ratio, 0.73; 95% confidence interval [CI], 0.58 to 0.91; P=0.006). In the fenofibrate group compared with the placebo group, the frequencies for any progression of retinopathy or maculopathy were 185 (32.1%) vs. 231 (40.2%); hazard ratio, 0.74; 95% CI, 0.61 to 0.90 and for the development of macular edema were 22 (3.8%) vs. 43 (7.5%); hazard ratio, 0.50; 95% CI, 0.30 to 0.84. Seventeen (3.0%) participants assigned fenofibrate and 28 (4.9%) assigned placebo were given treatment for retinopathy (hazard ratio, 0.58; 95% CI, 0.31 to 1.06). There was no effect on visual function, quality of life, or visual acuity. Trial-averaged estimated glomerular filtration rate was 7.9 (95% CI, 6.8 to 9.1) ml/min/1.73 m2 lower in participants in the fenofibrate group compared with the placebo group. Serious adverse events occurred in 208 (36.1%) participants allocated fenofibrate and 204 (35.5%) participants allocated placebo. CONCLUSIONS Fenofibrate reduced progression of diabetic retinopathy compared with placebo among participants with early retinal changes. (Funded by the National Institute for Health and Care Research; ClinicalTrials.gov number, NCT03439345; ISRCTN number, ISRCTN15073006.).
Collapse
Affiliation(s)
- David Preiss
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Jennifer Logue
- Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Emily Sammons
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Mohammed Zayed
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Jonathan Emberson
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Rachel Wade
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Karl Wallendszus
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Will Stevens
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Rosanna Cretney
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Simon Harding
- Department of Eye and Vision Science, University of Liverpool and St. Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
| | - Graham Leese
- Molecular and Clinical Medicine, University of Dundee, Dundee, United Kingdom
| | - Gemma Currie
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, United Kingdom
| | - Jane Armitage
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
3
|
Design, recruitment and baseline characteristics of the LENS trial. Diabet Med 2024:e15310. [PMID: 38385587 DOI: 10.1111/dme.15310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/31/2024] [Accepted: 02/03/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Findings from cardiovascular outcome trials suggest that treatment with fenofibrate may reduce the progression of diabetic retinopathy. However, no dedicated large-scale randomised trials have yet investigated this hypothesis. METHODS LENS is a streamlined randomised double-masked placebo-controlled trial, based in Scotland, assessing whether treatment with fenofibrate (145 mg tablet daily or, in the context of impaired renal function, on alternate days) in people with early retinopathy reduces progression to referable diabetic retinopathy (defined in NHS Scotland's Diabetic Eye Screening grading scheme as referable background or proliferative retinopathy, or referable maculopathy in either eye) or treatment with retinal laser, intravitreal injections or vitrectomy. Adults with diabetes mellitus and non-referable retinopathy (mild background retinopathy in both eyes or observable background retinopathy in one/both eyes at the most recent NHS retinal screening assessment; or observable maculopathy in one/both eyes in the previous 3 years) were eligible. Potential participants were identified from routinely collected healthcare data and followed up using regular contact from the research team and linkage to national electronic morbidity, mortality, biochemistry and retinal screening records. Study treatment was mailed to participants. RESULTS Between 18 September 2018 and 27 July 2021, 1151 participants were randomised. Their mean age was 61 (SD 12) years, 312 (27%) were female and 305 (26%) had type 1 diabetes. 96% had bilateral mild background retinopathy and 10% had observable maculopathy. CONCLUSIONS LENS will provide a robust evaluation of the efficacy of treating people at risk of progression of diabetic retinopathy with fenofibrate. Results are anticipated in mid-2024. TRIAL REGISTRATIONS NCT03439345; ISRCTN15073006; EuDRACT 2016-002656-24.
Collapse
|
4
|
Cai Y, Tu H, Wu C, Liu T, Chen S, Shen L, Xiao Q, Zhao S, Xu S, Lin W, Yan P, Dong J. Therapeutic potential of elema-1,3,7(11),8-tetraen-8,12-lactam from Curcuma wenyujin on diabetic retinopathy via anti-inflammatory and anti-angiogenic pathways. JOURNAL OF ETHNOPHARMACOLOGY 2024; 318:116843. [PMID: 37414197 DOI: 10.1016/j.jep.2023.116843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/08/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE In traditional Chinese medicine, the causes of diabetic retinopathy (DR) are blood stasis and heat. Curcuma wenyujin Y. H. Chen & C. Ling and its extracts have the effects of promoting blood circulation to remove blood stasis, clearing the heart, and cooling the blood, and have been used in the treatment of DR. Elema-1,3,7 (11),8-tetraen-8,12-lactam (Ele), an N-containing sesquiterpene isolated from this plant. However, the anti-inflammatory and anti-angiogenic effects of Ele and its therapeutic potential in DR are still unknown. AIM OF THE STUDY To evaluate the anti-inflammatory and anti-angiogenic effects of Ele and its therapeutic potential in DR. MATERIALS AND METHODS In vitro, anti-inflammatory and anti-angiogenic effects were assessed using TNF-α or VEGF-stimulated HUVECs. Protein expression was analyzed using Western blotting. ICAM-1 and TNF-α mRNA expressions were analyzed using real-time quantitative RT-PCR. The therapeutic potential in DR was assessed using both animal models of STZ-induced diabetes and oxygen-induced retinopathy. The retinal vascular permeability was measured using Evans blue, and the quantitation of retinal leukostasis using FITC-coupled Con A. The retinal neovascular tufts were analyzed using fluorescein angiography and counting pre-retinal vascular lumens. RESULTS Ele inhibited NF-κB pathway, and ICAM-1, TNF-α mRNA expression in TNF-α- stimulated HUVECs. It also inhibits the multistep process of angiogenesis by inhibiting the phosphorylation of VEGFR2 and its downstream signaling kinases Src, Erk1/2, Akt, and mTOR in VEGF-stimulated HUVECs. Intravitreal injection of Ele can significantly reduce retinal microvascular leakage, leukostasis, and expression of ICAM-1, TNF-α in diabetic rats and inhibits oxygen-induced retinal neovascularization and VEGFR2 phosphorylation in OIR mice. CONCLUSIONS Ele has anti-inflammatory and anti-angiogenic effects through inhibiting NF-κB and VEGFR2 signaling pathways, and it may be a potential drug candidate for DR.
Collapse
Affiliation(s)
- Yuan Cai
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Hongfeng Tu
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Cimei Wu
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Tong Liu
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Shuangshuang Chen
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Linlin Shen
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Qinwen Xiao
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Sumin Zhao
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Shaoying Xu
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Weiwei Lin
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Pengcheng Yan
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China
| | - Jianyong Dong
- Pharmacy School, Wenzhou Medical University, Wenzhou, Zhejiang Province, PR China.
| |
Collapse
|
5
|
Wang X, Liu X, Tzekov R, Yu C, Yang J, Feng Y, Wu Y, Xu Y, Li S, Li W. Fenofibrate Ameliorates Retinal Pigment Epithelium Injury Induced by Excessive Fat Through Upregulation of PI3K/AKT Signaling. Drug Des Devel Ther 2023; 17:3439-3452. [PMID: 38024539 PMCID: PMC10676092 DOI: 10.2147/dddt.s420178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 11/10/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose This study aimed to determine the effect and its mechanism of fenofibrate on retinal pigment epithelium (RPE) injury induced by excessive fat in vitro and in vivo. Methods ARPE-19 cells were co-incubated with palmitic acid (PA) and fenofibric acid (the active form of fenofibrate after metabolism in vivo) and mice fed with high-fat diet (HFD) were supplemented with fenofibrate. The following methods were used: Western blot and immunofluorescent staining to determine expressions of reactive oxygen species (ROS)-associated factors and proinflammatory cytokines; electroretinogram (ERG) c-wave to evaluate RPE function; TUNEL staining to detect the apoptotic cell in RPE tissue. Additionally, ARPE19 cells were treated with PI3K/AKT inhibitor or agonist to investigate the mechanism of fenofibric acid inhibiting PA-induced RPE damage. Results We found that the application of PA inhibited RPE cell viability in a dose-dependent manner, and increased the levels of NAPDH oxidase 4 (NOX4), 3-nitrotyrosin (3-NT), intracellular adhesion molecule-1(ICAM1), tumor necrosis factor alpha (TNFα) and vascular endothelial growth factor (VEGF) at 400μM. The application of fenofibric acid resulted in the inhibition of NOX4, 3-NT, TNFα, ICAM1 and VEGF expression in ARPE-19 cells treated with PA. Moreover, wortmannin, as a selective inhibitor of PI3K/AKT pathway, abolished the effects of fenofibrate on the oxidative stress and inflammation in ARPE-19 cells. In addition, 740Y-P, a selective agonist of PI3K/AKT pathway, enhanced the protective action of fenofibrate. Meanwhile, in vivo dosing of fenofibrate ameliorated the downregulated amplitudes of ERG c-wave in HFD-fed mice and suppressed the HFD-induced oxidative injury and inflammatory response in RPE tissues. Conclusion Our results suggested that fenofibrate ameliorated RPE cell damage induced by excessive fat in vitro and in vivo, in part, through activation of the PI3K/AKT signaling pathway.
Collapse
Affiliation(s)
- Xue Wang
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
- Suzhou Institute of Biomedical Engineering and Technology, University of Science and Technology of China, Suzhou, People’s Republic of China
- Department of Ophthalmology, Second Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
| | - Xiaomei Liu
- Suzhou Institute of Biomedical Engineering and Technology, University of Science and Technology of China, Suzhou, People’s Republic of China
| | - Radouil Tzekov
- Department of Ophthalmology, University of South Florida, Tampa, FL, USA
| | - Chaofeng Yu
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
| | - Jiasong Yang
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
- Shanghai Aier Eye Hospital, Shanghai, People’s Republic of China
| | - Yuliang Feng
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
| | - Yajun Wu
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
| | - Yali Xu
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
| | - Shiying Li
- Department of Ophthalmology, Xiang’an Hospital of Xiamen University, Xiamen University, Xiamen, People’s Republic of China
| | - Wensheng Li
- Aier School of Ophthalmology, Central South University, Changsha, People’s Republic of China
- Shanghai Aier Eye Hospital, Shanghai, People’s Republic of China
- Shanghai Aier Eye Insititute, Shanghai, People’s Republic of China
| |
Collapse
|
6
|
Tan H, Fu X, Chen Y, Wang Y, Chen D. Hyperlipidemia and lipid-lowering therapy in diabetic retinopathy (DR): A bibliometric study and visualization analysis in 1993-2023. Heliyon 2023; 9:e21109. [PMID: 37916126 PMCID: PMC10616351 DOI: 10.1016/j.heliyon.2023.e21109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 10/04/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Background Diabetic retinopathy (DR) is a common complication in diabetic patients. DR is also a neurodegenerative disease. Patients with hyperglycemia, hyperlipidemia, and hypertension are vulnerable to retinopathy development. While the roles of blood glucose and blood pressure in the development of retinopathy have been extensively studied, the relationship between body fat and DR pathogenesis and the impact of lipid-reducing drugs on DR has just emerged as a research hotspot in DR study. We aim to visualize the contributions and cooperation of reporters, organizations, and nations, in addition to the research hotspots and trends in DR-related lipid research from 1993 to 2023, by bibliometric analysis. Methods We extracted all publications about DR-related lipid research from 1993 to 2023 from the Web of Science Core Collection, and bibliometric features were studied using VOSviewer and the CiteSpace program. Results 1402 documents were retrieved. The number of studies has risen consistently for three decades, from an average of 16.8/year in the 1990s to 28.8/year in the 2000s, 64.5/year in 2010s, and reached 112/year in 2020-2022, confirming they are hot research topic in the field. These reports were from 93 nations/regions, with the USA, China, Japan, Australia, and England taking the leading positions. Diabetes Research and Clinical Practice was the journal that published the most studies, and Diabetes Care was the most quoted. We identified 6979 authors, with Wong TY having the most papers and being the most commonly co-cited. The most popular keyword, according to our research, is diabetic retinopathy. Oxidative stress, diabetic macular edema (DME), lipid peroxidation, and other topics have often been investigated. Conclusion DR-related lipid research is conducted mainly in North America, Asia, Oceania, and Europe. Much study has centered on the relationship between lipid-lowering therapy and DR pathogenesis. These studies strongly support using lipid-reducing medications (fenofibrate, statins, and omega-3 PUFAs), combined with hyperglycemia and hypertension therapy, to prevent and treat DR. However, the impact of fenofibrate or statin on retinopathy is not correlated with their action on blood lipid profiles. Thus, more randomized clinical trials with primary endpoints related to DR in T1D or T2D are merited. In addition, the lipid biomarker for DR (lipid aldehydes, ALEs, and cholesterol crystals), the action of lipid-reducing medicines on retinopathy, the mechanism of lipid-lowering medications preventing or curing DR, and ocular delivery of lipid-lowering drugs to diabetic patients are predicted as the research focus in the future in the DR-related lipid research field.
Collapse
Affiliation(s)
- Haishan Tan
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiangyu Fu
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yongjiang Chen
- The School of Optometry and Vision Science, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| | - Yujiao Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Danian Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
7
|
Hammer SS, Dorweiler TF, McFarland D, Adu-Agyeiwaah Y, Mast N, El-Darzi N, Fortmann SD, Nooti S, Agrawal DK, Pikuleva IA, Abela GS, Grant MB, Busik JV. Cholesterol crystal formation is a unifying pathogenic mechanism in the development of diabetic retinopathy. Diabetologia 2023; 66:1705-1718. [PMID: 37311879 PMCID: PMC10390399 DOI: 10.1007/s00125-023-05949-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 04/18/2023] [Indexed: 06/15/2023]
Abstract
AIMS/HYPOTHESIS Hyper-reflective crystalline deposits found in retinal lesions have been suggested to predict the progression of diabetic retinopathy, but the nature of these structures remains unknown. METHODS Scanning electron microscopy and immunohistochemistry were used to identify cholesterol crystals (CCs) in human donor, pig and mouse tissue. The effects of CCs were analysed in bovine retinal endothelial cells in vitro and in db/db mice in vivo using quantitative RT-PCR, bulk RNA sequencing, and cell death and permeability assays. Cholesterol homeostasis was determined using 2H2O and 2H7-cholesterol. RESULTS We identified hyper-reflective crystalline deposits in human diabetic retina as CCs. Similarly, CCs were found in the retina of a diabetic mouse model and a high-cholesterol diet-fed pig model. Cell culture studies demonstrated that treatment of retinal cells with CCs can recapitulate all major pathogenic mechanisms leading to diabetic retinopathy, including inflammation, cell death and breakdown of the blood-retinal barrier. Fibrates, statins and α-cyclodextrin effectively dissolved CCs present in in vitro models of diabetic retinopathy, and prevented CC-induced endothelial pathology. Treatment of a diabetic mouse model with α-cyclodextrin reduced cholesterol levels and CC formation in the retina, and prevented diabetic retinopathy. CONCLUSIONS/INTERPRETATION We established that cholesterol accumulation and CC formation are a unifying pathogenic mechanism in the development of diabetic retinopathy.
Collapse
Affiliation(s)
- Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Tim F Dorweiler
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Delaney McFarland
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Yvonne Adu-Agyeiwaah
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Seth D Fortmann
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sunil Nooti
- Department of Translational Research, Western University of Health Sciences, Pomona, CA, USA
| | - Devendra K Agrawal
- Department of Translational Research, Western University of Health Sciences, Pomona, CA, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - George S Abela
- Department of Medicine, Michigan State University, East Lansing, MI, USA
| | - Maria B Grant
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
8
|
Dong L, Cheng R, Ma X, Liang W, Hong Y, Li H, Zhou K, Du Y, Takahashi Y, Zhang X, Li XR, Ma JX. Regulation of Monocyte Activation by PPARα Through Interaction With the cGAS-STING Pathway. Diabetes 2023; 72:958-972. [PMID: 37058417 PMCID: PMC10281240 DOI: 10.2337/db22-0654] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 03/30/2023] [Indexed: 04/15/2023]
Abstract
Monocyte activation plays an important role in diabetic complications such as diabetic retinopathy (DR). However, the regulation of monocyte activation in diabetes remains elusive. Fenofibrate, an agonist of peroxisome proliferator-activated receptor-α (PPARα), has shown robust therapeutic effects on DR in patients with type 2 diabetes. Here we found that PPARα levels were significantly downregulated in monocytes from patients with diabetes and animal models, correlating with monocyte activation. Fenofibrate attenuated monocyte activation in diabetes, while PPARα knockout alone induced monocyte activation. Furthermore, monocyte-specific PPARα overexpression ameliorated, while monocyte-specific PPARα knockout aggravated monocyte activation in diabetes. PPARα knockout impaired mitochondrial function while also increasing glycolysis in monocytes. PPARα knockout increased cytosolic mitochondrial DNA release and activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in monocytes under diabetic conditions. STING knockout or STING inhibitor attenuated monocyte activation induced by diabetes or by PPARα knockout. These observations suggest that PPARα negatively regulates monocyte activation through metabolic reprogramming and interaction with the cGAS-STING pathway.
Collapse
Affiliation(s)
- Lijie Dong
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Rui Cheng
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Xiang Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Wentao Liang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Yaru Hong
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Tianjin, China
| | - Hui Li
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Tianjin, China
| | - Kelu Zhou
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Yanhong Du
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Yusuke Takahashi
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Xiaomin Zhang
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Tianjin, China
| | - Xiao-rong Li
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Tianjin, China
| | - Jian-xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC
| |
Collapse
|
9
|
Bloomgarden Z. A diabetes update. J Diabetes 2023; 15:542-544. [PMID: 37310420 PMCID: PMC10345974 DOI: 10.1111/1753-0407.13434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/05/2023] [Indexed: 06/14/2023] Open
Affiliation(s)
- Zachary Bloomgarden
- Department of MedicineDivision of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount SinaiNew YorkNYUSA
| |
Collapse
|
10
|
Simó R, Hernández C. Fenofibrate for Treating Diabetic Eye Disease. Diabetes 2023; 72:838-840. [PMID: 37339356 DOI: 10.2337/dbi22-0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/29/2023] [Indexed: 06/22/2023]
Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| |
Collapse
|
11
|
Lee J, Hu Z, Wang YA, Nath D, Liang W, Cui Y, Ma JX, Duerfeldt AS. Design, Synthesis, and Structure-Activity Relationships of Biaryl Anilines as Subtype-Selective PPAR-alpha Agonists. ACS Med Chem Lett 2023; 14:766-776. [PMID: 37312852 PMCID: PMC10258832 DOI: 10.1021/acsmedchemlett.3c00056] [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: 02/16/2023] [Accepted: 05/16/2023] [Indexed: 06/15/2023] Open
Abstract
The role of peroxisome proliferator-activated receptor alpha (PPARα) in retinal biology is clarifying, and evidence demonstrates that novel PPARα agonists hold promising therapeutic utility for diseases like diabetic retinopathy and age-related macular degeneration. Herein, we disclose the design and initial structure-activity relationships for a new biaryl aniline PPARα agonistic chemotype. Notably, this series exhibits subtype selectivity for PPARα over other isoforms, a phenomenon postulated to be due to the unique benzoic acid headgroup. This biphenyl aniline series is sensitive to B-ring functionalization but allows isosteric replacement, and provides an opportunity for C-ring extension. From this series, 3g, 6j, and 6d were identified as leads with <90 nM potency in a cell-based luciferase assay cell and exhibited efficacy in various disease-relevant cell contexts, thereby setting the stage for further characterization in more advanced in vitro and in vivo models.
Collapse
Affiliation(s)
- Julia
J. Lee
- Department
of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ziwei Hu
- Department
of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yuhong Anna Wang
- Department
of Physiology, University of Oklahoma Health
Sciences Center, Oklahoma
City, Oklahoma 73104, United States
| | - Dinesh Nath
- Department
of Chemistry and Biochemistry, University
of Oklahoma, Norman, Oklahoma 73019, United
States
| | - Wentao Liang
- Department
of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - Yi Cui
- Department
of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27101, United States
- Department
of Ophthalmology, Fujian Medical University
Union Hospital, Fujian 350001, China
| | - Jian-Xing Ma
- Department
of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - Adam S. Duerfeldt
- Department
of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
12
|
Zivkovic S, Maric G, Cvetinovic N, Lepojevic-Stefanovic D, Bozic Cvijan B. Anti-Inflammatory Effects of Lipid-Lowering Drugs and Supplements-A Narrative Review. Nutrients 2023; 15:nu15061517. [PMID: 36986246 PMCID: PMC10053759 DOI: 10.3390/nu15061517] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Since the establishment of the "lipid hypothesis", according to which, cholesterol level is directly correlated to the risk of CVD, many different lipid-lowering agents have been introduced in clinical practice. A majority of these drugs, in addition to their lipid-lowering properties, may also exhibit some anti-inflammatory and immunomodulatory activities. This hypothesis was based on the observation that a decrease in lipid levels occurs along with a decrease in inflammation. Insufficient reduction in the inflammation during treatment with lipid-lowering drugs could be one of the explanations for treatment failure and recurrent CVD events. Thus, the aim of this narrative review was to evaluate the anti-inflammatory properties of currently available lipid-lowering medications including statins, ezetimibe, bile acid sequestrants (BAS), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fibrates, omega-3 fatty acids, and niacin, as well as dietary supplements and novel drugs used in modern times.
Collapse
Affiliation(s)
- Stefan Zivkovic
- Department of Cardiovascular Disease, Zvezdara University Medical Center, 11000 Belgrade, Serbia
| | - Gorica Maric
- Faculty of Medicine, Institute of Epidemiology, University of Belgrade, Dr. Subotica 8, 11000 Belgrade, Serbia
| | - Natasa Cvetinovic
- Department of Cardiovascular Disease, University Medical Center "Dr Dragisa Misovic-Dedinje", 11000 Belgrade, Serbia
| | | | - Bojana Bozic Cvijan
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| |
Collapse
|
13
|
Grimes KR, Aloney A, Skondra D, Chhablani J. Effects of systemic drugs on the development and progression of age-related macular degeneration. Surv Ophthalmol 2023; 68:332-346. [PMID: 36731638 DOI: 10.1016/j.survophthal.2023.01.007] [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: 01/17/2022] [Revised: 01/18/2023] [Accepted: 01/22/2023] [Indexed: 02/01/2023]
Abstract
Age-related macular degeneration (AMD) is the leading cause of severe loss of central vision among people over 50. The pathophysiology of the disease is multifactorial and can be attributed to genetics, aging, inflammation, environmental factors, and lifestyle factors including smoking, diet, obesity, and alcohol consumption. While there is no treatment for dry AMD, the current standard treatment for wet AMD is an intraocular injection of anti-vascular endothelial growth factor-an effective, yet expensive, therapy that requires ongoing treatment. As the aging population continues to grow, and AMD diagnoses continue to rise, new treatments should be explored to reduce vision complications and decrease treatment burdens. Many systemic conditions have progressive pathological changes that may affect AMD, particularly those affecting systemic vasculature like diabetes and cardiovascular status. Consequently, systemic drugs used to treat coexistent systemic diseases may influence some of the pathogenic mechanisms of AMD and lead its progression or delay. In this review we explore the current literature to summarize the findings of the reported effects of antihypertensive, immunosuppressants, cholesterol lowering agents, nonsteroidal anti-inflammatory drugs, dopamine precursors, hypoglycemic agents, and anticoagulants on AMD.
Collapse
Affiliation(s)
- Kara R Grimes
- School of Medicine, New York Medical College, Valhalla, NY, USA
| | - Abhilasha Aloney
- Eye Care Institute, PBMA'S H.V. Desai Eye Hospital, Pune, Maharashtra, India
| | - Dimitra Skondra
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL, USA
| | - Jay Chhablani
- Department of Ophthalmology, The University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
14
|
Kim NH, Choi J, Kim YH, Lee H, Kim SG. Addition of fenofibrate to statins is associated with risk reduction of diabetic retinopathy progression in patients with type 2 diabetes and metabolic syndrome: A propensity-matched cohort study. DIABETES & METABOLISM 2023; 49:101428. [PMID: 36720383 DOI: 10.1016/j.diabet.2023.101428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 01/01/2023] [Accepted: 01/15/2023] [Indexed: 01/30/2023]
Abstract
AIM This study aimed to determine the association between fenofibrate added to statin therapy and diabetic retinopathy progression. METHODS In this propensity-matched study using the Korean National Health Insurance Service cohort (2002-2019), patients with type 2 diabetes and metabolic syndrome (≥ 30 years) receiving statin therapy were matched 1:2 by propensity score into the statin plus fenofibrate group (n = 22,395) and statin-only group (n = 43,191). The primary outcome was a composite of diabetic retinopathy progression including vitreous hemorrhage, vitrectomy, laser photocoagulation, intravitreous injection therapy and retinal detachment. RESULTS The median (quartiles) follow-up duration was 44.0 (27.6-70.6) months. For the primary outcome, the incidence rate per 1,000 person-years was 9.66 in the statin-only group and 8.68 in the statin-plus-fenofibrate group. The risk of the primary outcome was significantly lower (hazard ratio [HR]=0.88; 95% confidence interval [0.81;0.96] P = 0.005) in the statin-plus-fenofibrate group than in the statin-only group. Only patients with pre-existing retinopathy showed benefits from fenofibrate treatment (HR=0.83 [0.73;0.95] P = 0.006). In addition, the statin plus fenofibrate group exhibited significantly lower risks of vitreous hemorrhage (HR= 0.86 [0.75;0.995] P = 0.042), laser photocoagulation (HR=0.86 [0.77;0.96] P = 0.009) and intravitreous injection therapy (HR=0.73 [0.59;0.90] P = 0.003) than those in the statin-only group. There was no significant interaction between the different characteristics at baseline and the treatment effect. CONCLUSION The addition of fenofibrate to statins was associated with significantly lower risk of diabetic retinopathy progression than statin therapy alone in patients with type 2 diabetes and metabolic syndrome.
Collapse
Affiliation(s)
- Nam Hoon Kim
- Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Jimi Choi
- Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Young Ho Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Hwa Lee
- Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea
| | - Sin Gon Kim
- Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea.
| |
Collapse
|
15
|
Zhou T, Yan K, Zhang Y, Zhu L, Liao Y, Zheng X, Chen Y, Li X, Liu Z, Zhang Z. Fenofibrate suppresses corneal neovascularization by regulating lipid metabolism through PPARα signaling pathway. Front Pharmacol 2022; 13:1000254. [PMID: 36588740 PMCID: PMC9800935 DOI: 10.3389/fphar.2022.1000254] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Purpose: The purpose of this study was to explore the potential underlying mechanism of anti-vascular effects of peroxisome proliferator-activated receptor α (PPARα) agonist fenofibrate against corneal neovascularization (CNV) through the changes of lipid metabolism during CNV. Methods: A suture-induced CNV model was established and the clinical indications were evaluated from day 1 to day 7. Treatments of vehicle and fenofibrate were performed for 5 days after suture and the CNV areas were compared among the groups. The eyeballs were collected for histological analysis, malondialdehyde (MDA) measurement, terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining, western blot, quantitative real-time PCR (qRT-PCR) assays and immunohistochemical (IHC) staining to elucidate pathological changes and the underlying mechanism. Results: Lipi-Green staining and MDA measurement showed that lipid deposition and peroxidation were increased in the CNV cornea while the expression of long-chain acyl-coenzyme A synthetase 1 (ACSL1), carnitine palmitoyltransterase 1A(CPT1A) and medium-chain acyl-coenzyme A dehydrogenase (ACADM), which are key enzymes of fatty acid β-oxidation (FAO) and targeted genes of peroxisome proliferator-activated receptor alpha (PPARα) pathway, were decreased in CNV cornea. Fenofibrate suppressed lipid accumulation and peroxidation damage in the CNV cornea. Fenofibrate upregulated the expression levels of PPARα, ACSL1, CPT1A, and ACADM compared with vehicle group. IHC staining indicated that fenofibrate also decreased the expression of VEGFa, VEGFc, TNFα, IL1β and CD68. Conclusion: Disorder of lipid metabolism may be involved in the formation of suture-induced CNV and fenofibrate played anti-neovascularization and anti-inflammatory roles on cornea by regulating the key enzymes of lipid metabolism and ameliorating lipid peroxidation damage of cornea through PPARα signaling pathway.
Collapse
Affiliation(s)
- Tong Zhou
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Department of Pharmacy, Xiang’an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Ke Yan
- The First Affiliated Hospital, Department of Ophthalmology, Hengyang Medical School, University of South China, Hengyang, China
| | - Yuhan Zhang
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Linfangzi Zhu
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Yi Liao
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Xiaoxiang Zheng
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Yongxiong Chen
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China
| | - Xiaoxin Li
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China,Department of Ophthalmology and Clinical Centre of Optometry, Peking University People’s Hospital, Beijing, China,*Correspondence: Zhaoqiang Zhang, ; Zuguo Liu, ; Xiaoxin Li,
| | - Zuguo Liu
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China,The First Affiliated Hospital, Department of Ophthalmology, Hengyang Medical School, University of South China, Hengyang, China,*Correspondence: Zhaoqiang Zhang, ; Zuguo Liu, ; Xiaoxin Li,
| | - Zhaoqiang Zhang
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China,Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Fujian Provincial Key Laboratory of Corneal and Ocular Surface Diseases, Xiamen, China,*Correspondence: Zhaoqiang Zhang, ; Zuguo Liu, ; Xiaoxin Li,
| |
Collapse
|
16
|
Yuan T, Dong L, Pearsall EA, Zhou K, Cheng R, Ma JX. The Protective Role of Microglial PPARα in Diabetic Retinal Neurodegeneration and Neurovascular Dysfunction. Cells 2022; 11:cells11233869. [PMID: 36497130 PMCID: PMC9739170 DOI: 10.3390/cells11233869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/21/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
Microglial activation and subsequent pathological neuroinflammation contribute to diabetic retinopathy (DR). However, the underlying mechanisms of microgliosis, and means to effectively suppress pathological microgliosis, remain incompletely understood. Peroxisome proliferator-activated receptor alpha (PPARα) is a transcription factor that regulates lipid metabolism. The present study aimed to determine if PPARα affects pathological microgliosis in DR. In global Pparα mice, retinal microglia exhibited decreased structural complexity and enlarged cell bodies, suggesting microglial activation. Microglia-specific conditional Pparα-/- (PCKO) mice showed decreased retinal thickness as revealed by optical coherence tomography. Under streptozotocin (STZ)-induced diabetes, diabetic PCKO mice exhibited decreased electroretinography response, while diabetes-induced retinal dysfunction was alleviated in diabetic microglia-specific Pparα-transgenic (PCTG) mice. Additionally, diabetes-induced retinal pericyte loss was exacerbated in diabetic PCKO mice and alleviated in diabetic PCTG mice. In cultured microglial cells with the diabetic stressor 4-HNE, metabolic flux analysis demonstrated that Pparα ablation caused a metabolic shift from oxidative phosphorylation to glycolysis. Pparα deficiency also increased microglial STING and TNF-α expression. Taken together, these findings revealed a critical role for PPARα in pathological microgliosis, neurodegeneration, and vascular damage in DR, providing insight into the underlying molecular mechanisms of microgliosis in this context and suggesting microglial PPARα as a potential therapeutic target.
Collapse
Affiliation(s)
- Tian Yuan
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Lijie Dong
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Elizabeth A. Pearsall
- Vision Research Center, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Kelu Zhou
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Rui Cheng
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
- Correspondence: (R.C.); (J.-X.M.); Tel.: +1-336-716-3914 (R.C.); +1-336-716-4676 (J.-X.M.)
| | - Jian-Xing Ma
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
- Correspondence: (R.C.); (J.-X.M.); Tel.: +1-336-716-3914 (R.C.); +1-336-716-4676 (J.-X.M.)
| |
Collapse
|
17
|
Bryl A, Mrugacz M, Falkowski M, Zorena K. The Effect of Hyperlipidemia on the Course of Diabetic Retinopathy—Literature Review. J Clin Med 2022; 11:jcm11102761. [PMID: 35628887 PMCID: PMC9146710 DOI: 10.3390/jcm11102761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/29/2022] [Accepted: 05/11/2022] [Indexed: 12/16/2022] Open
Abstract
Diabetes mellitus is a very important social issue, and its retinal complications continue to be one of the major causes of blindness worldwide. The effect of glucose level on the development of retinal retinopathy has been the subject of numerous studies and is well understood. Hypertension and hyperlipidemia have been known to be important risk factors in the development of diabetes complications. However, the mechanisms of this effect have not been fully explained and raise a good deal of controversy. The latest research results suggest that some lipoproteins are closely correlated with the incidence of diabetic retinopathy and that by exerting an impact on their level the disease course can be modulated. Moreover, pharmacotherapy which reduces the level of lipids, particularly by means of statins and fibrate, has been shown to alleviate diabetic retinopathy. Therefore, we have decided to review the latest literature on diabetic retinopathy with respect to the impact of hyperlipidemia and possible preventive measures
Collapse
Affiliation(s)
- Anna Bryl
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland;
- Correspondence:
| | - Małgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland;
| | - Mariusz Falkowski
- PhD Studies, Medical University of Bialystok, 15-089 Bialystok, Poland;
| | - Katarzyna Zorena
- Department of Immunobiology and Environmental Microbiology, Medical University of Gdansk, 80-211 Gdansk, Poland;
| |
Collapse
|
18
|
Jenkins AJ, Grant MB, Busik JV. Lipids, hyperreflective crystalline deposits and diabetic retinopathy: potential systemic and retinal-specific effect of lipid-lowering therapies. Diabetologia 2022; 65:587-603. [PMID: 35149880 PMCID: PMC9377536 DOI: 10.1007/s00125-022-05655-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 12/14/2021] [Indexed: 12/19/2022]
Abstract
The metabolically active retina obtains essential lipids by endogenous biosynthesis and from the systemic circulation. Clinical studies provide limited and sometimes conflicting evidence as to the relationships between circulating lipid levels and the development and progression of diabetic retinopathy in people with diabetes. Cardiovascular-system-focused clinical trials that also evaluated some retinal outcomes demonstrate the potential protective power of lipid-lowering therapies in diabetic retinopathy and some trials with ocular primary endpoints are in progress. Although triacylglycerol-lowering therapies with fibrates afforded some protection against diabetic retinopathy, the effect was independent of changes in traditional blood lipid classes. While systemic LDL-cholesterol lowering with statins did not afford protection against diabetic retinopathy in most clinical trials, and none of the trials focused on retinopathy as the main outcome, data from very large database studies suggest the possible effectiveness of statins. Potential challenges in these studies are discussed, including lipid-independent effects of fibrates and statins, modified lipoproteins and retinal-specific effects of lipid-lowering drugs. Dysregulation of retinal-specific cholesterol metabolism leading to retinal cholesterol accumulation and potential formation of cholesterol crystals are also addressed.
Collapse
Affiliation(s)
- Alicia J Jenkins
- NHMRC Clinical Trials Centre, The University of Sydney, Sydney, NSW, Australia
| | - Maria B Grant
- Department of Ophthalmology and Vision Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
19
|
Hanaguri J, Nagai N, Yokota H, Kushiyama A, Watanabe M, Yamagami S, Nagaoka T. Fenofibrate Nano-Eyedrops Ameliorate Retinal Blood Flow Dysregulation and Neurovascular Coupling in Type 2 Diabetic Mice. Pharmaceutics 2022; 14:pharmaceutics14020384. [PMID: 35214116 PMCID: PMC8876509 DOI: 10.3390/pharmaceutics14020384] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/22/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023] Open
Abstract
We investigated the effect of fenofibrate nano-eyedrops (FenoNano) on impaired retinal blood flow regulation in type 2 diabetic mice. Six-week-old db/db mice were randomly divided into an untreated group (n = 6) and treated group, which received FenoNano (n = 6). The longitudinal changes in retinal neuronal function and blood flow responses to systemic hyperoxia and flicker stimulation were evaluated every 2 weeks in diabetic db/db mice treated with FenoNano (n = 6) or the vehicle (n = 6) from ages 8–14 weeks. The retinal blood flow was assessed using laser speckle flowgraphy. We also evaluated the expressions of vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP), and aquaporin 4 (AQP4) and the phosphorylation of peroxisome proliferator-activated receptor alpha (PPAR-α) by immunofluorescence. In db/db mice treated with FenoNano, both responses were restored from 8 to 14 weeks of age compared with the diabetic mice treated with the vehicle. At 14 weeks of age, the impaired regulation of retinal blood flow during systemic hyperoxia and flicker stimulation improved to about half of that in the db/db mice treated with FenoNano compared with the db/m control group (n = 5). FenoNano prevented the activation of VEGF and GFAP expression and increased the AQP4 expression and the phosphorylation of PPAR-α detected by immunofluorescence compared with the diabetic mice treated with the vehicle eyedrop. Our results suggested that the fenofibrate nano-eyedrops prevent retinal glial dysfunction via the phosphorylation of PPAR-α and improves the retinal blood flow dysregulation in type 2 diabetic mice.
Collapse
Affiliation(s)
- Junya Hanaguri
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Noriaki Nagai
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, Higashi-Osaka 577-8502, Osaka, Japan;
| | - Harumasa Yokota
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Akifumi Kushiyama
- Department of Pharmacotherapy, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan;
| | - Masahisa Watanabe
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Satoru Yamagami
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Taiji Nagaoka
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
- Correspondence: or ; Tel.: +81-3-3972-8111
| |
Collapse
|
20
|
Varghese R, Krishnamoorthy SG, Abdalla HEH, Baiju A, Borra SS. A systematic review of preclinical animal studies on fenofibrate’s potential role in type 1 diabetic micro-vascular complications. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-97902022e21332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
21
|
Lin Y, Wang Y, Li PF. PPARα: An emerging target of metabolic syndrome, neurodegenerative and cardiovascular diseases. Front Endocrinol (Lausanne) 2022; 13:1074911. [PMID: 36589809 PMCID: PMC9800994 DOI: 10.3389/fendo.2022.1074911] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that is involved in lipid metabolism of various tissues. Different metabolites of fatty acids and agonists like fibrates activate PPARα for its transactivative or repressive function. PPARα is known to affect diverse human diseases, and we focus on advanced studies of its transcriptional regulation in these diseases. In MAFLD, PPARα shows a protective function with its upregulation of lipid oxidation and mitochondrial biogenesis and transcriptional repression of inflammatory genes, which is similar in Alzheimer's disease and cardiovascular disease. Activation of PPARα also prevents the progress of diabetes complications; however, its role in diabetes and cancers remains uncertain. Some PPARα-specific agonists, such as Wy14643 and fenofibrate, have been applied in metabolic syndrome treatment, which might own potential in wider application. Future studies may further explore the functions and interventions of PPARα in cancer, diabetes, immunological diseases, and neurodegenerative disease.
Collapse
Affiliation(s)
- Yijun Lin
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Cardiovascular Disease, Xiamen, China
- *Correspondence: Yijun Lin, ; Yan Wang, ; Pei-feng Li,
| | - Yan Wang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Cardiovascular Disease, Xiamen, China
- *Correspondence: Yijun Lin, ; Yan Wang, ; Pei-feng Li,
| | - Pei-feng Li
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Cardiovascular Disease, Xiamen, China
- *Correspondence: Yijun Lin, ; Yan Wang, ; Pei-feng Li,
| |
Collapse
|
22
|
Neurovascular Impairment and Therapeutic Strategies in Diabetic Retinopathy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:ijerph19010439. [PMID: 35010703 PMCID: PMC8744686 DOI: 10.3390/ijerph19010439] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/25/2021] [Accepted: 12/30/2021] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy has recently been defined as a highly specific neurovascular complication of diabetes. The chronic progression of the impairment of the interdependence of neurovascular units (NVUs) is associated with the pathogenesis of diabetic retinopathy. The NVUs consist of neurons, glial cells, and vascular cells, and the interdependent relationships between these cells are disturbed under diabetic conditions. Clinicians should understand and update the current knowledge of the neurovascular impairments in diabetic retinopathy. Above all, neuronal cell death is an irreversible change, and it is directly related to vision loss in patients with diabetic retinopathy. Thus, neuroprotective and vasoprotective therapies for diabetic retinopathy must be established. Understanding the physiological and pathological interdependence of the NVUs is helpful in establishing neuroprotective and vasoprotective therapies for diabetic retinopathy. This review focuses on the pathogenesis of the neurovascular impairments and introduces possible neurovascular protective therapies for diabetic retinopathy.
Collapse
|
23
|
Therapeutic Effects of Fenofibrate Nano-Emulsion Eye Drops on Retinal Vascular Leakage and Neovascularization. BIOLOGY 2021; 10:biology10121328. [PMID: 34943243 PMCID: PMC8698460 DOI: 10.3390/biology10121328] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 12/07/2021] [Accepted: 12/10/2021] [Indexed: 01/08/2023]
Abstract
Macular edema caused by retinal vascular leakage and ocular neovascularization are the leading causes of severe vision loss in diabetic retinopathy (DR) and age-related macular degeneration (AMD) patients. Oral administration of fenofibrate, a PPARα agonist, has shown therapeutic effects on macular edema and retinal neovascularization in diabetic patients. To improve the drug delivery to the retina and its efficacy, we have developed a nano-emulsion-based fenofibrate eye drop formulation that delivered significantly higher amounts of the drug to the retina compared to the systemic administration, as measured by liquid chromatography-mass spectrometer (LC-MS). The fenofibrate eye drop decreased leukocytes adherent to retinal vasculature and attenuated overexpression of multiple inflammatory factors in the retina of very low-density lipoprotein receptor knockout (Vldlr-/-) mice, a model manifesting AMD phenotypes, and streptozotocin-induced diabetic rats. The fenofibrate eye drop also reduced retinal vascular leakage in these models. The laser-induced choroidal neovascularization was also alleviated by the fenofibrate eye drop. There were no detectable ocular toxicities associated with the fenofibrate eye drop treatment. These findings suggest that fenofibrate can be delivered efficiently to the retina through topical administration of the nano-emulsion eye drop, which has therapeutic potential for macular edema and neovascularization.
Collapse
|
24
|
Lee D, Tomita Y, Allen W, Tsubota K, Negishi K, Kurihara T. PPARα Modulation-Based Therapy in Central Nervous System Diseases. Life (Basel) 2021; 11:life11111168. [PMID: 34833044 PMCID: PMC8622664 DOI: 10.3390/life11111168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 12/11/2022] Open
Abstract
The burden of neurodegenerative diseases in the central nervous system (CNS) is increasing globally. There are various risk factors for the development and progression of CNS diseases, such as inflammatory responses and metabolic derangements. Thus, curing CNS diseases requires the modulation of damaging signaling pathways through a multitude of mechanisms. Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear hormone receptors (PPARα, PPARβ/δ, and PPARγ), and they work as master sensors and modulators of cellular metabolism. In this regard, PPARs have recently been suggested as promising therapeutic targets for suppressing the development of CNS diseases and their progressions. While the therapeutic role of PPARγ modulation in CNS diseases has been well reviewed, the role of PPARα modulation in these diseases has not been comprehensively summarized. The current review focuses on the therapeutic roles of PPARα modulation in CNS diseases, including those affecting the brain, spinal cord, and eye, with recent advances. Our review will enable more comprehensive therapeutic approaches to modulate PPARα for the prevention of and protection from various CNS diseases.
Collapse
Affiliation(s)
- Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan;
| | - Yohei Tomita
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
- Correspondence: (Y.T.); (T.K.); Tel.: +1-617-919-2533 (Y.T.); +81-3-5636-3204 (T.K.)
| | - William Allen
- Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | | | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan;
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Correspondence: (Y.T.); (T.K.); Tel.: +1-617-919-2533 (Y.T.); +81-3-5636-3204 (T.K.)
| |
Collapse
|
25
|
Tomita Y, Usui-Ouchi A, Nilsson AK, Yang J, Ko M, Hellström A, Fu Z. Metabolism in Retinopathy of Prematurity. Life (Basel) 2021; 11:life11111119. [PMID: 34832995 PMCID: PMC8620873 DOI: 10.3390/life11111119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
Retinopathy of prematurity is defined as retinal abnormalities that occur during development as a consequence of disturbed oxygen conditions and nutrient supply after preterm birth. Both neuronal maturation and retinal vascularization are impaired, leading to the compensatory but uncontrolled retinal neovessel growth. Current therapeutic interventions target the hypoxia-induced neovessels but negatively impact retinal neurons and normal vessels. Emerging evidence suggests that metabolic disturbance is a significant and underexplored risk factor in the disease pathogenesis. Hyperglycemia and dyslipidemia correlate with the retinal neurovascular dysfunction in infants born prematurely. Nutritional and hormonal supplementation relieve metabolic stress and improve retinal maturation. Here we focus on the mechanisms through which metabolism is involved in preterm-birth-related retinal disorder from clinical and experimental investigations. We will review and discuss potential therapeutic targets through the restoration of metabolic responses to prevent disease development and progression.
Collapse
Affiliation(s)
- Yohei Tomita
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Ayumi Usui-Ouchi
- Department of Ophthalmology, Juntendo University Urayasu Hospital, Chiba 279-0021, Japan;
| | - Anders K. Nilsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 413 19 Gothenburg, Sweden; (A.K.N.); (A.H.)
| | - Jay Yang
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Minji Ko
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
| | - Ann Hellström
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 413 19 Gothenburg, Sweden; (A.K.N.); (A.H.)
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.T.); (J.Y.); (M.K.)
- Correspondence:
| |
Collapse
|
26
|
Bonora BM, Albiero M, Morieri ML, Cappellari R, Amendolagine FI, Mazzucato M, Zambon A, Iori E, Avogaro A, Fadini GP. Fenofibrate increases circulating haematopoietic stem cells in people with diabetic retinopathy: a randomised, placebo-controlled trial. Diabetologia 2021; 64:2334-2344. [PMID: 34368894 DOI: 10.1007/s00125-021-05532-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/18/2021] [Indexed: 11/27/2022]
Abstract
AIM/HYPOTHESIS In two large RCTs, fenofibrate reduced the progression of diabetic retinopathy. We investigated whether fenofibrate increases circulating haematopoietic stem/progenitor cells (HSPCs), which have vascular properties and have been shown to protect from retinopathy. METHODS We conducted a 12 week parallel-group RCT comparing fenofibrate vs placebo. Patients with diabetic retinopathy and without other conditions that would affect HSPCs were enrolled at a tertiary diabetes outpatient clinic and randomised to receive fenofibrate or placebo based on a computer-generated sequence. Patients and study staff assessing the outcomes were blinded to group assignment. The primary endpoint was the change in the levels of circulating HSPCs, defined by expression of the stem cell markers CD34 and/or CD133. Secondary endpoints were the changes in endothelial progenitor cells, lipids, soluble mediators and gene expression. We used historical data on the association between HSPCs and retinopathy outcomes to estimate the effect of fenofibrate on retinopathy progression. RESULTS Forty-two participants with diabetic retinopathy were randomised and 41 completed treatment and were analysed (20 in the placebo group and 21 in the fenofibrate group). Mean age was 57.4 years, diabetes duration was 18.2 years and baseline HbA1c was 60 mmol/mol (7.6%). When compared with placebo, fenofibrate significantly increased levels of HSPCs expressing CD34 and/or CD133. CD34+ HSPCs non-significantly declined in the placebo group (mean ± SD -44.2 ± 31.6 cells/106) and significantly increased in the fenofibrate group (53.8 ± 31.1 cells/106). The placebo-subtracted increase in CD34+ HSPCs from baseline was 30% (99.3 ± 43.3 cells/106; p = 0.027) which, projected onto the relationship between HSPC levels and retinopathy outcomes, yielded an OR of retinopathy progression of 0.67 for fenofibrate vs placebo. Endothelial differentiation of CD34+ cells, estimated by the %KDR (kinase insert domain receptor) expression, was significantly reduced by fenofibrate. Fenofibrate decreased serum triacylglycerols, but the change in triacylglycerols was unrelated to the change in HSPCs. No effect was observed for endothelial progenitor cells, cytokines/chemokines (stromal-cell derived factor-1, vascular endothelial growth factor, monocyte chemoattractant protein-1) and gene expression in peripheral blood mononuclear cells. CONCLUSIONS/INTERPRETATION Fenofibrate increased HSPC levels in participants with diabetic retinopathy and this mechanism may explain why fenofibrate reduced retinopathy progression in previous studies. TRIAL REGISTRATION ClinicalTrials.gov NCT01927315.
Collapse
Affiliation(s)
- Benedetta Maria Bonora
- Department of Medicine, University of Padova, Padua, Italy
- Veneto Institute of Molecular Medicine, Padua, Italy
| | - Mattia Albiero
- Department of Medicine, University of Padova, Padua, Italy
- Veneto Institute of Molecular Medicine, Padua, Italy
| | | | | | | | | | - Alberto Zambon
- Department of Medicine, University of Padova, Padua, Italy
| | | | - Angelo Avogaro
- Department of Medicine, University of Padova, Padua, Italy
| | - Gian Paolo Fadini
- Department of Medicine, University of Padova, Padua, Italy.
- Veneto Institute of Molecular Medicine, Padua, Italy.
| |
Collapse
|
27
|
Pemafibrate Prevents Retinal Dysfunction in a Mouse Model of Unilateral Common Carotid Artery Occlusion. Int J Mol Sci 2021; 22:ijms22179408. [PMID: 34502311 PMCID: PMC8431531 DOI: 10.3390/ijms22179408] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular diseases lead to retinal ischemia, one of the leading causes of blindness. Retinal ischemia triggers pathological retinal glial responses and functional deficits. Therefore, maintaining retinal neuronal activities and modulating pathological gliosis may prevent loss of vision. Previously, pemafibrate, a selective peroxisome proliferator-activated receptor alpha modulator, was nominated as a promising drug in retinal ischemia. However, a protective role of pemafibrate remains untouched in cardiovascular diseases-mediated retinal ischemia. Therefore, we aimed to unravel systemic and retinal alterations by treating pemafibrate in a new murine model of retinal ischemia caused by cardiovascular diseases. Adult C57BL/6 mice were orally administered pemafibrate (0.5 mg/kg) for 4 days, followed by unilateral common carotid artery occlusion (UCCAO). After UCCAO, pemafibrate was continuously supplied to mice until the end of experiments. Retinal function (a-and b-waves and the oscillatory potentials) was measured using electroretinography on day 5 and 12 after UCCAO. Moreover, the retina, liver, and serum were subjected to qPCR, immunohistochemistry, or ELISA analysis. We found that pemafibrate enhanced liver function, elevated serum levels of fibroblast growth factor 21 (FGF21), one of the neuroprotective molecules in the eye, and protected against UCCAO-induced retinal dysfunction, observed with modulation of retinal gliosis and preservation of oscillatory potentials. Our current data suggest a promising pemafibrate therapy for the suppression of retinal dysfunction in cardiovascular diseases.
Collapse
|
28
|
Simó R, Simó-Servat O, Bogdanov P, Hernández C. Neurovascular Unit: A New Target for Treating Early Stages of Diabetic Retinopathy. Pharmaceutics 2021; 13:pharmaceutics13081320. [PMID: 34452281 PMCID: PMC8399715 DOI: 10.3390/pharmaceutics13081320] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
The concept of diabetic retinopathy as a microvascular disease has evolved and is now considered a more complex diabetic complication in which neurovascular unit impairment plays an essential role and, therefore, can be considered as a main therapeutic target in the early stages of the disease. However, neurodegeneration is not always the apparent primary event in the natural story of diabetic retinopathy, and a phenotyping characterization is recommendable to identify those patients in whom neuroprotective treatment might be of benefit. In recent years, a myriad of treatments based on neuroprotection have been tested in experimental models, but more interestingly, there are drugs with a dual activity (neuroprotective and vasculotropic). In this review, the recent evidence concerning the therapeutic approaches targeting neurovascular unit impairment will be presented, along with a critical review of the scientific gaps and problems which remain to be overcome before our knowledge can be transferred to clinical practice.
Collapse
Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
- Correspondence:
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| |
Collapse
|
29
|
Escandon P, Vasini B, Whelchel AE, Nicholas SE, Matlock HG, Ma JX, Karamichos D. The role of peroxisome proliferator-activated receptors in healthy and diseased eyes. Exp Eye Res 2021; 208:108617. [PMID: 34010603 PMCID: PMC8594540 DOI: 10.1016/j.exer.2021.108617] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/23/2022]
Abstract
Peroxisome Proliferator-Activated Receptors (PPARs) are a family of nuclear receptors that play essential roles in modulating cell differentiation, inflammation, and metabolism. Three subtypes of PPARs are known: PPAR-alpha (PPARα), PPAR-gamma (PPARγ), and PPAR-beta/delta (PPARβ/δ). PPARα activation reduces lipid levels and regulates energy homeostasis, activation of PPARγ results in regulation of adipogenesis, and PPARβ/δ activation increases fatty acid metabolism and lipolysis. PPARs are linked to various diseases, including but not limited to diabetes, non-alcoholic fatty liver disease, glaucoma and atherosclerosis. In the past decade, numerous studies have assessed the functional properties of PPARs in the eye and key PPAR mechanisms have been discovered, particularly regarding the retina and cornea. PPARγ and PPARα are well established in their functions in ocular homeostasis regarding neuroprotection, neovascularization, and inflammation, whereas PPARβ/δ isoform function remains understudied. Naturally, studies on PPAR agonists and antagonists, associated with ocular pathology, have also gained traction with the development of PPAR synthetic ligands. Studies on PPARs has significantly influenced novel therapeutics for diabetic eye disease, ocular neuropathy, dry eye, and age-related macular degeneration (AMD). In this review, therapeutic potentials and implications will be highlighted, as well as reported adverse effects. Further investigations are necessary before any of the PPARs ligands can be utilized, in the clinics, to treat eye diseases. Future research on the prominent role of PPARs will help unravel the complex mechanisms involved in order to prevent and treat ocular diseases.
Collapse
Affiliation(s)
- Paulina Escandon
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Brenda Vasini
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Amy E Whelchel
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA
| | - Sarah E Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - H Greg Matlock
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA; Harold Hamm Oklahoma Diabetes Center, 1000 N Lincoln Blvd, Oklahoma City, OK, USA
| | - Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
| |
Collapse
|
30
|
Joharapurkar A, Patel V, Kshirsagar S, Patel MS, Savsani H, Jain M. Effect of dual PPAR-α/γ agonist saroglitazar on diabetic retinopathy and oxygen-induced retinopathy. Eur J Pharmacol 2021; 899:174032. [PMID: 33753107 DOI: 10.1016/j.ejphar.2021.174032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/04/2021] [Accepted: 03/11/2021] [Indexed: 01/27/2023]
Abstract
Diabetic retinopathy is a serious complication of diabetes, marked by retinal vascular damage, inflammation, and angiogenesis. This study's objective was to assess the potential benefits of saroglitazar, a peroxisome proliferator-activated receptor-alpha/gamma (PPAR-α/γ) agonist in diabetic retinopathy. Diabetic retinopathy was induced by streptozotocin in Sprague Dawley rats. The effect of saroglitazar was also assessed in the oxygen-induced retinopathy model in newborn rats and VEGF-induced angiogenesis in the chick chorioallantoic membrane (CAM) assay. Treatment of saroglitazar (1 and 4 mg/kg, oral) for 12 weeks significantly ameliorated retinal vascular leakage and leukostasis in the diabetic rats. Saroglitazar decreased oxidative stress, VEGF receptor signalling, NF-κBp65, and ICAM-1 in the retina of diabetic rats. The beneficial effects of saroglitazar (1 and 4 mg/kg, oral) were also observed on the neovascularization in oxygen-induced retinopathy in newborn rats. Saroglitazar also reduced VEGF-induced angiogenesis in CAM assay. This study reveals that saroglitazar has the potential to prevent the progression of retinopathy in diabetic patients.
Collapse
Affiliation(s)
- Amit Joharapurkar
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India.
| | - Vishal Patel
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India
| | - Samadhan Kshirsagar
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India
| | - Maulik S Patel
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India
| | - Hardikkumar Savsani
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India
| | - Mukul Jain
- Department of Pharmacology and Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej Bavla NH 8A, Moraiya, Ahmedabad, 382210, India
| |
Collapse
|
31
|
Abstract
The uncontrolled growth of blood vessels is a major pathological factor in human eye diseases that can result in blindness. This effect is termed ocular neovascularization and is seen in diabetic retinopathy, age-related macular degeneration, glaucoma and retinopathy of prematurity. Current treatments for these diseases include laser photocoagulation, topical injection of corticosteroids, intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents and vitreoretinal surgery. Although strategies to inhibit VEGF have proved to be dramatically successful in some clinical studies, there remains the possibility of significant adverse effects regarding the blockade of crucial physiological roles of VEGF and the invasive nature of the treatments. Moreover, it is evident that other pro-angiogenic factors also play important roles in the development of these diseases, as seen in cases in which anti-VEGF therapies have failed. Therefore, new types of effective treatments are required. In this review, we discuss a promising strategy for the treatment of ocular neovascular diseases, i.e., the inhibition of hypoxia-inducible factor (HIF), a master regulator of angiogenesis. We also summarize promising recently investigated HIF inhibitors as treatments for ocular diseases. This review will facilitate more comprehensive approaches to understanding the protective aspects of HIF inhibition in the prevention of ocular diseases.
Collapse
|
32
|
Lee D, Tomita Y, Miwa Y, Jeong H, Mori K, Tsubota K, Kurihara T. Fenofibrate Protects against Retinal Dysfunction in a Murine Model of Common Carotid Artery Occlusion-Induced Ocular Ischemia. Pharmaceuticals (Basel) 2021; 14:ph14030223. [PMID: 33799938 PMCID: PMC7999063 DOI: 10.3390/ph14030223] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 01/01/2023] Open
Abstract
Ocular ischemia is a common cause of blindness and plays a detrimental role in various diseases such as diabetic retinopathy, occlusion of central retinal arteries, and ocular ischemic syndrome. Abnormalities of neuronal activities in the eye occur under ocular ischemic conditions. Therefore, protecting their activities may prevent vision loss. Previously, peroxisome proliferator-activated receptor alpha (PPARα) agonists were suggested as promising drugs in ocular ischemia. However, the potential therapeutic roles of PPARα agonists in ocular ischemia are still unknown. Thus, we attempted to unravel systemic and ocular changes by treatment of fenofibrate, a well-known PPARα agonist, in a new murine model of ocular ischemia. Adult mice were orally administered fenofibrate (60 mg/kg) for 4 days once a day, followed by induction of ocular ischemia by unilateral common carotid artery occlusion (UCCAO). After UCCAO, fenofibrate was continuously supplied to mice once every 2 days during the experiment period. Electroretinography was performed to measure retinal functional changes. Furthermore, samples from the retina, liver, and blood were subjected to qPCR, Western blot, or ELISA analysis. We found that fenofibrate boosted liver function, increased serum levels of fibroblast growth factor 21 (FGF21), one of the neuroprotective molecules in the central nervous system, and protected against UCCAO-induced retinal dysfunction. Our current data suggest a promising fenofibrate therapy in ischemic retinopathies.
Collapse
Affiliation(s)
- Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Yohei Tomita
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA
| | - Yukihiro Miwa
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Animal Eye Care, Tokyo Animal Eye Clinic, Tokyo 158-0093, Japan
| | - Heonuk Jeong
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kiwako Mori
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Tsubota Laboratory, Inc., Tokyo 160-0016, Japan
- Correspondence: (K.T.); (T.K.); Tel.: +81-3-5636-3269 (K.T.); +81-3-5636-3204 (T.K.)
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (D.L.); (Y.T.); (Y.M.); (H.J.); (K.M.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan
- Correspondence: (K.T.); (T.K.); Tel.: +81-3-5636-3269 (K.T.); +81-3-5636-3204 (T.K.)
| |
Collapse
|
33
|
Fu Z, Kern TS, Hellström A, Smith LEH. Fatty acid oxidation and photoreceptor metabolic needs. J Lipid Res 2021; 62:100035. [PMID: 32094231 PMCID: PMC7905050 DOI: 10.1194/jlr.tr120000618] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/14/2020] [Indexed: 01/31/2023] Open
Abstract
Photoreceptors have high energy demands and a high density of mitochondria that produce ATP through oxidative phosphorylation (OXPHOS) of fuel substrates. Although glucose is the major fuel for CNS brain neurons, in photoreceptors (also CNS), most glucose is not metabolized through OXPHOS but is instead metabolized into lactate by aerobic glycolysis. The major fuel sources for photoreceptor mitochondria remained unclear for almost six decades. Similar to other tissues (like heart and skeletal muscle) with high metabolic rates, photoreceptors were recently found to metabolize fatty acids (palmitate) through OXPHOS. Disruption of lipid entry into photoreceptors leads to extracellular lipid accumulation, suppressed glucose transporter expression, and a duel lipid/glucose fuel shortage. Modulation of lipid metabolism helps restore photoreceptor function. However, further elucidation of the types of lipids used as retinal energy sources, the metabolic interaction with other fuel pathways, as well as the cross-talk among retinal cells to provide energy to photoreceptors is not fully understood. In this review, we will focus on the current understanding of photoreceptor energy demand and sources, and potential future investigations of photoreceptor metabolism.
Collapse
Affiliation(s)
- Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Manton Center for Orphan Disease, Boston Children's Hospital, Boston, MA, USA.
| | - Timothy S Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Irvine, CA, USA
| | - Ann Hellström
- Section for Ophthalmology, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
34
|
Pathogenic role of human C-reactive protein in diabetic retinopathy. Clin Sci (Lond) 2021; 134:1613-1629. [PMID: 32602547 DOI: 10.1042/cs20200085] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 01/08/2023]
Abstract
PURPOSE Elevated blood levels of C-reactive protein (CRP) are associated with both type 1 and type 2 diabetes and diabetic complications, such as diabetic retinopathy (DR). However, its pathogenic role in DR remains unknown. The present study aims to investigate the potential role of CRP in DR pathogenesis and explore its underlying mechanism. MATERIALS AND METHODS Human CRP transgenic (hCRP-Tg) rats were employed for streptozotocin (STZ)-induced diabetic and oxygen-induced retinopathy (OIR) models. The retina function was monitored by electroretinography (ERG) and retinal thickness was measured by optical coherence tomography (OCT). TUNEL and cell death ELISA were performed to measure the apoptosis. Oxidative stress was detected by the measurement of reactive oxygen species (ROS) in cells and 3-Nitrotyrosine staining in tissue sections. RESULTS In non-diabetic condition, hCRP-Tg with elevated hCRP levels in the retinas demonstrated declined ERG responses and decreased retinal thickness. In STZ-induced diabetic condition, overexpression of hCRP deteriorated retinal neurodegeneration as shown by ERG and apoptosis assays. hCRP also exacerbated retinal leukostasis and acellular capillary formation induced by diabetes. In the OIR model, overexpression of hCRP exacerbated retinal neovascularization (NV). In retinal cell lines, hCRP treatment induced cell death and over-production of ROS. Furthermore, hCRP-induced overexpression of pro-inflammatory, pro-oxidative, and pro-angiogenic factors was associated with up-regulation of CD32 and the NF-κB signaling in the retinas. CONCLUSIONS Elevated hCRP levels play a pathogenic role in DR. Targeting the hCRP-CD32-NF-κB pathway may represent a novel therapeutic strategy for DR.
Collapse
|
35
|
Enright JM, Zhang S, Thebeau C, Siebert E, Jin A, Gadiraju V, Zhang X, Chen S, Semenkovich CF, Rajagopal R. Fenofibrate Reduces the Severity of Neuroretinopathy in a Type 2 Model of Diabetes without Inducing Peroxisome Proliferator-Activated Receptor Alpha-Dependent Retinal Gene Expression. J Clin Med 2020; 10:jcm10010126. [PMID: 33396512 PMCID: PMC7794763 DOI: 10.3390/jcm10010126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/27/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022] Open
Abstract
Fenofibrate slows the progression of clinical diabetic retinopathy (DR), but its mechanism of action in the retina remains unclear. Fenofibrate is a known agonist of peroxisome proliferator-activated receptor alpha (PPARα), a transcription factor critical for regulating metabolism, inflammation and oxidative stress. Using a DR mouse model, db/db, we tested the hypothesis that fenofibrate slows early DR progression by activating PPARα in the retina. Relative to healthy littermates, six-month-old db/db mice exhibited elevated serum triglycerides and cholesterol, retinal gliosis, and electroretinography (ERG) changes including reduced b-wave amplitudes and delayed oscillatory potentials. These pathologic changes in the retina were improved by oral fenofibrate. However, fenofibrate did not induce PPARα target gene expression in whole retina or isolated Müller glia. The capacity of the retina to respond to PPARα was further tested by delivering the PPARα agonist GW590735 to the intraperitoneal or intravitreous space in mice carrying the peroxisome proliferator response element (PPRE)-luciferase reporter. We observed strong induction of the reporter in the liver, but no induction in the retina. In summary, fenofibrate treatment of db/db mice prevents the development of early DR but is not associated with induction of PPARα in the retina.
Collapse
Affiliation(s)
- Jennifer M. Enright
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
| | - Sheng Zhang
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
| | - Christina Thebeau
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
| | - Emily Siebert
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX 75390, USA;
| | - Alexander Jin
- St. Louis University School of Medicine, St. Louis, MO 63104, USA;
| | - Veda Gadiraju
- University of Washington Medical School, Seattle, WA 98195, USA;
| | - Xiaodong Zhang
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
| | - Shiming Chen
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
| | - Clay F. Semenkovich
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis, St. Louis, MO 63110, USA;
| | - Rithwick Rajagopal
- John F. Hardesty Department of Ophthalmology, Washington University in St. Louis, St. Louis, MO 63110, USA; (J.M.E.); (S.Z.); (C.T.); (X.Z.); (S.C.)
- Correspondence:
| |
Collapse
|
36
|
Small-Molecule Modulation of PPARs for the Treatment of Prevalent Vascular Retinal Diseases. Int J Mol Sci 2020; 21:ijms21239251. [PMID: 33291567 PMCID: PMC7730325 DOI: 10.3390/ijms21239251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/29/2020] [Accepted: 12/02/2020] [Indexed: 02/08/2023] Open
Abstract
Vascular-related retinal diseases dramatically impact quality of life and create a substantial burden on the healthcare system. Age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity are leading causes of irreversible blindness. In recent years, the scientific community has made great progress in understanding the pathology of these diseases and recent discoveries have identified promising new treatment strategies. Specifically, compelling biochemical and clinical evidence is arising that small-molecule modulation of peroxisome proliferator-activated receptors (PPARs) represents a promising approach to simultaneously address many of the pathological drivers of these vascular-related retinal diseases. This has excited academic and pharmaceutical researchers towards developing new and potent PPAR ligands. This review highlights recent developments in PPAR ligand discovery and discusses the downstream effects of targeting PPARs as a therapeutic approach to treating retinal vascular diseases.
Collapse
|
37
|
Mazzeo A, Gai C, Trento M, Porta M, Beltramo E. Effects of thiamine and fenofibrate on high glucose and hypoxia-induced damage in cell models of the inner blood-retinal barrier. Acta Diabetol 2020; 57:1423-1433. [PMID: 32656709 DOI: 10.1007/s00592-020-01565-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/23/2020] [Indexed: 12/15/2022]
Abstract
AIMS Although diabetic retinopathy has long been considered a microvascular complication, retinal neurodegeneration and inflammation may precede its clinical manifestations. Despite all research efforts, the primary treatment options remain laser photocoagulation and anti-vascular endothelial growth factor (VEGF) intravitreal injections, both aggressive and targeting the late stages of the disease. Medical treatments addressing the early phases of diabetic retinopathy are therefore needed. We aimed at verifying if thiamine and fenofibrate protect the cells of the inner blood-retinal barrier from the metabolic stress induced by diabetic-like conditions. METHODS Human microvascular endothelial cells (HMECs), retinal pericytes (HRPs) and Müller cells (MIO-M1) were cultured in intermittent high glucose (intHG) and/or hypoxia, with addition of fenofibrate or thiamine. Modulation of adhesion molecules and angiogenic factors was addressed. RESULTS Integrins β1/αVβ3 and ICAM1 were upregulated in HMECs/HRPs cultured in diabetic-like conditions, as well as metalloproteases MMP2/9 in HRP, with a reduction in their inhibitor TIMP1; MMP2 increased also in HMEC, and TIMP1 decreased in MIO-M1. VEGF and HIF-1α were strongly increased in HMEC in intHG + hypoxia, and VEGF also in HRP. Ang-1/2 augmented in HMEC/MIO-M1, and MCP-1 in HRP/MIO-M1 in intHG + hypoxia. Thiamine was able to normalize all such abnormal modulations, while fenofibrate had effects in few cases only. CONCLUSIONS We suggest that endothelial cells and pericytes are more affected than Müller cells by diabetic-like conditions. Fenofibrate shows a controversial behavior, potentially positive on Müller cells and pericytes, but possibly detrimental to endothelium, while thiamine confirms once more to be an effective agent in reducing diabetes-induced retinal damage.
Collapse
Affiliation(s)
- Aurora Mazzeo
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Chiara Gai
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Marina Trento
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Massimo Porta
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
| | - Elena Beltramo
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy.
| |
Collapse
|
38
|
Liu W, Ha Y, Xia F, Zhu S, Li Y, Shi S, Mei FC, Merkley K, Vizzeri G, Motamedi M, Cheng X, Liu H, Zhang W. Neuronal Epac1 mediates retinal neurodegeneration in mouse models of ocular hypertension. J Exp Med 2020; 217:133574. [PMID: 31918438 PMCID: PMC7144517 DOI: 10.1084/jem.20190930] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/06/2019] [Accepted: 11/26/2019] [Indexed: 12/24/2022] Open
Abstract
Progressive loss of retinal ganglion cells (RGCs) leads to irreversible visual deficits in glaucoma. Here, we found that the level of cyclic AMP and the activity and expression of its mediator Epac1 were increased in retinas of two mouse models of ocular hypertension. Genetic depletion of Epac1 significantly attenuated ocular hypertension–induced detrimental effects in the retina, including vascular inflammation, neuronal apoptosis and necroptosis, thinning of ganglion cell complex layer, RGC loss, and retinal neuronal dysfunction. With bone marrow transplantation and various Epac1 conditional knockout mice, we further demonstrated that Epac1 in retinal neuronal cells (especially RGCs) was responsible for their death. Consistently, pharmacologic inhibition of Epac activity prevented RGC loss. Moreover, in vitro study on primary RGCs showed that Epac1 activation was sufficient to induce RGC death, which was mechanistically mediated by CaMKII activation. Taken together, these findings indicate that neuronal Epac1 plays a critical role in retinal neurodegeneration and suggest that Epac1 could be considered a target for neuroprotection in glaucoma.
Collapse
Affiliation(s)
- Wei Liu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX.,Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yonju Ha
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Fan Xia
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Shuang Zhu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Yi Li
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Shuizhen Shi
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center at Houston, Houston, TX
| | - Kevin Merkley
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Gianmarco Vizzeri
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Massoud Motamedi
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center at Houston, Houston, TX
| | - Hua Liu
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX
| | - Wenbo Zhang
- Department of Ophthalmology & Visual Sciences, University of Texas Medical Branch, Galveston, TX.,Departments of Neuroscience, Cell Biology & Anatomy, University of Texas Medical Branch, Galveston, TX
| |
Collapse
|
39
|
Fenofibrate prevents iron induced activation of canonical Wnt/β-catenin and oxidative stress signaling in the retina. NPJ Aging Mech Dis 2020; 6:12. [PMID: 33145027 PMCID: PMC7599211 DOI: 10.1038/s41514-020-00050-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/09/2020] [Indexed: 12/20/2022] Open
Abstract
Accumulating evidence strongly implicates iron in the pathogenesis of aging and disease. Iron levels have been found to increase with age in both the human and mouse retinas. We and others have shown that retinal diseases such as age-related macular degeneration and diabetic retinopathy are associated with disrupted iron homeostasis, resulting in retinal iron accumulation. In addition, hereditary disorders due to mutation in one of the iron regulatory genes lead to age dependent retinal iron overload and degeneration. However, our knowledge on whether iron toxicity contributes to the retinopathy is limited. Recently, we reported that iron accumulation is associated with the upregulation of retinal and renal renin-angiotensin system (RAS). Evidences indicate that multiple genes/components of the RAS are targets of Wnt/β-catenin signaling. Interestingly, aberrant activation of Wnt/β-catenin signaling is observed in several degenerative diseases. In the present study, we explored whether iron accumulation regulates canonical Wnt signaling in the retina. We found that in vitro and in vivo iron treatment resulted in the upregulation of Wnt/β-catenin signaling and its downstream target genes including renin-angiotensin system in the retina. We confirmed further that iron activates canonical Wnt signaling in the retina using TOPFlash T-cell factor/lymphoid enhancer factor promoter assay and Axin2-LacZ reporter mouse. The presence of an iron chelator or an antioxidant reversed the iron-mediated upregulation of Wnt/β-catenin signaling in retinal pigment epithelial (RPE) cells. In addition, treatment of RPE cells with peroxisome proliferator-activated receptor (PPAR) α-agonist fenofibrate prevented iron-induced activation of oxidative stress and Wnt/β-catenin signaling by chelating the iron. The role of fenofibrate, an FDA-approved drug for hyperlipidemia, as an iron chelator has potentially significant therapeutic impact on iron associated degenerative diseases.
Collapse
|
40
|
Fu D, Yu JY, Connell AR, Hookham MB, McLeese RH, Lyons TJ. Effects of Modified Low-Density Lipoproteins and Fenofibrate on an Outer Blood-Retina Barrier Model: Implications for Diabetic Retinopathy. J Ocul Pharmacol Ther 2020; 36:754-764. [PMID: 33107777 PMCID: PMC7757531 DOI: 10.1089/jop.2020.0068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose: There is a lack of treatment for early diabetic retinopathy (DR), including blood-retina barrier (BRB) breakdown. The robust clinical benefit of fenofibrate in DR provides an opportunity to explore disease mechanisms and therapeutic targets. We have previously found that modified lipoproteins contribute to DR and that fenofibrate protects the inner BRB. We now investigate (1) whether modified lipoproteins elicit outer BRB injury and (2) whether fenofibrate may alleviate such damage. Methods: Human retinal pigment epithelium ARPE-19 cells were cultured in semipermeable transwells to establish a monolayer barrier and then exposed to heavily oxidized, glycated low-density lipoprotein (HOG-LDL, 25–300 mg/L, up to 24 h) versus native (N)-LDL. Transepithelial electric resistance (TEER) and FITC-dextran permeability were measured. The effects of fenofibrate, its active metabolite fenofibric acid, and other peroxisome proliferator-activated receptor (PPARα) agonists (gemfibrozil, bezafibrate, and WY14643) were evaluated, with and without the PPARα antagonist GW6471 or the adenosine monophosphate-activated protein kinase (AMPK) inhibitor Compound C. Results: HOG-LDL induced concentration- and time-dependent barrier impairment, decreasing TEER and increasing dextran leakage, effects that were amplified by high glucose. Fenofibric acid, but not fenofibrate, gemfibrozil, bezafibrate, or WY14643, attenuated barrier impairment. This effect was reversed significantly by Compound C, but not by GW6471. Conclusions: Modified lipoproteins elicited outer BRB injury in an experimental model, which was reduced by fenofibric acid through a PPARα-independent, AMPK-mediated mechanism. These findings suggest a protective role of fenofibric acid on the outer BRB in diabetic retina.
Collapse
Affiliation(s)
- Dongxu Fu
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Jeremy Y Yu
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes and Metabolic Diseases, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Anna R Connell
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Michelle B Hookham
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Rebecca H McLeese
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes and Metabolic Diseases, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Timothy J Lyons
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes and Metabolic Diseases, Medical University of South Carolina, Charleston, South Carolina, USA.,Diabetes Free SC, BlueCross BlueShield of South Carolina, Columbia, South Carolina, USA
| |
Collapse
|
41
|
PPARα Agonist Oral Therapy in Diabetic Retinopathy. Biomedicines 2020; 8:biomedicines8100433. [PMID: 33086679 PMCID: PMC7589723 DOI: 10.3390/biomedicines8100433] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy (DR) is an eye condition that develops after chronically poorly-managed diabetes, and is presently the main cause for blindness on a global scale. Current treatments for DR such as laser photocoagulation, topical injection of corticosteroids, intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents and vitreoretinal surgery are only applicable at the late stages of DR and there are possibilities of significant adverse effects. Moreover, the forms of treatment available for DR are highly invasive to the eyes. Safer and more effective pharmacological treatments are required for DR treatment, in particular at an early stage. In this review, we cover recently investigated promising oral pharmacotherapies, the methods of which are safer, easier to use, patient-friendly and pain-free, in clinical studies. We especially focus on peroxisome proliferator-activator receptor alpha (PPARα) agonists in which experimental evidence suggests PPARα activation may be closely related to the attenuation of vascular damages, including lipid-induced toxicity, inflammation, an excess of free radical generation, endothelial dysfunction and angiogenesis. Furthermore, oral administration of selective peroxisome proliferator-activated receptor alpha modulator (SPPARMα) agonists may induce hepatic fibroblast growth factor 21 expression, indirectly resulting in retinal protection in animal studies. Our review will enable more comprehensive approaches for understanding protective roles of PPARα for the prevention of DR development.
Collapse
|
42
|
Abstract
Vision loss, among the most feared complications of diabetes, is primarily caused by diabetic retinopathy, a disease that manifests in well-recognized, characteristic microvascular lesions. The reasons for retinal susceptibility to damage in diabetes are unclear, especially considering that microvascular networks are found in all tissues. However, the unique metabolic demands of retinal neurons could account for their vulnerability in diabetes. Photoreceptors are the first neurons in the visual circuit and are also the most energy-demanding cells of the retina. Here, we review experimental and clinical evidence linking photoreceptors to the development of diabetic retinopathy. We then describe the influence of retinal illumination on photoreceptor metabolism, effects of light modulation on the severity of diabetic retinopathy, and recent clinical trials testing the treatment of diabetic retinopathy with interventions that impact photoreceptor metabolism. Finally, we introduce several possible mechanisms that could link photoreceptor responses to light and the development of retinal vascular disease in diabetes. Collectively, these concepts form the basis for a growing body of investigative efforts aimed at developing novel pharmacologic and nonpharmacologic tools that target photoreceptor physiology to treat a very common cause of blindness across the world.
Collapse
|
43
|
Hsu YJ, Lin CW, Cho SL, Yang WS, Yang CM, Yang CH. Protective Effect of Fenofibrate on Oxidative Stress-Induced Apoptosis in Retinal-Choroidal Vascular Endothelial Cells: Implication for Diabetic Retinopathy Treatment. Antioxidants (Basel) 2020; 9:antiox9080712. [PMID: 32764528 PMCID: PMC7464418 DOI: 10.3390/antiox9080712] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/28/2020] [Accepted: 08/04/2020] [Indexed: 12/24/2022] Open
Abstract
Diabetic retinopathy (DR) is an important microvascular complication of diabetes and one of the leading causes of blindness in developed countries. Two large clinical studies showed that fenofibrate, a peroxisome proliferator-activated receptor type α (PPAR-α) agonist, reduces DR progression. We evaluated the protective effects of fenofibrate on retinal/choroidal vascular endothelial cells under oxidative stress and investigated the underlying mechanisms using RF/6A cells as the model system and paraquat (PQ) to induce oxidative stress. Pretreatment with fenofibrate suppressed reactive oxygen species (ROS) production, decreased cellular apoptosis, diminished the changes in the mitochondrial membrane potential, increased the mRNA levels of peroxiredoxin (Prx), thioredoxins (Trxs), B-cell lymphoma 2 (Bcl-2), and Bcl-xl, and reduced the level of B-cell lymphoma 2-associated X protein (Bax) in PQ-stimulated RF/6A cells. Western blot analysis revealed that fenofibrate repressed apoptosis through cytosolic and mitochondrial apoptosis signal-regulated kinase-1 (Ask)-Trx-related signaling pathways, including c-Jun amino-terminal kinase (JNK) phosphorylation, cytochrome c release, caspase 3 activation, and poly (ADP-ribose) polymerase-1 (PARP-1) cleavage. These protective effects of fenofibrate on RF/6A cells may be attributable to its anti-oxidative ability. Our research suggests that fenofibrate could serve as an effective adjunct therapy for ocular oxidative stress-related disorders, such as DR.
Collapse
Affiliation(s)
- Ying-Jung Hsu
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 1, Jen Ai Road Section 1, Taipei 100, Taiwan; (Y.-J.H.); (C.-W.L.); (W.-S.Y.)
| | - Chao-Wen Lin
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 1, Jen Ai Road Section 1, Taipei 100, Taiwan; (Y.-J.H.); (C.-W.L.); (W.-S.Y.)
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Zhongshan South Road, Taipei 100, Taiwan;
| | - Sheng-Li Cho
- Department of Internal Medicine, National Taiwan University Hospital, No. 7, Zhongshan South Road, Taipei 100, Taiwan;
| | - Wei-Shiung Yang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 1, Jen Ai Road Section 1, Taipei 100, Taiwan; (Y.-J.H.); (C.-W.L.); (W.-S.Y.)
- Department of Internal Medicine, National Taiwan University Hospital, No. 7, Zhongshan South Road, Taipei 100, Taiwan;
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Zhongshan South Road, Taipei 100, Taiwan;
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Zhongshan South Road, Taipei 100, Taiwan;
- Correspondence: ; Tel.: +886-2-23123456 (ext. 63193)
| |
Collapse
|
44
|
Lin YC, Chen YC, Horng JT, Chen JM. Association of Fenofibrate and Diabetic Retinopathy in Type 2 Diabetic Patients: A Population-Based Retrospective Cohort Study in Taiwan. MEDICINA (KAUNAS, LITHUANIA) 2020; 56:medicina56080385. [PMID: 32751875 PMCID: PMC7466234 DOI: 10.3390/medicina56080385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/18/2020] [Accepted: 07/28/2020] [Indexed: 01/31/2023]
Abstract
Background and Objectives: Fenofibrate, a PPAR-α agonist, has been demonstrated to reduce the progression of diabetic retinopathy (DR) and the need for laser treatment in a FIELD (Fenofibrate Intervention and Event Lowering in Diabetes) study. However, in the subgroup of patients without pre-existing DR, there was no significant difference in the progression of DR between the fenofibrate group and the placebo group. In this study, we aim to investigate whether fenofibrate can decrease the risk of incident DR in a population-based cohort study of type 2 diabetic patients in Taiwan. Materials and Methods: A total of 32,253 type 2 diabetic patients without previous retinopathy were retrieved from 892,419 patients in 2001-2002. They were then divided into two groups based on whether they were exposed to fenofibrate or not. The patients were followed until a diagnosis of diabetic retinopathy was made or until the year 2008. Results: With a follow-up period of 6.8 ± 1.5 years and 5.4 ± 2.6 years for 2500 fenofibrate users and 29,753 non-users, respectively, the Cox proportional hazard regression analysis revealed that the hazard ratio (HR) of new onset retinopathy was 0.57 (95% CI 0.57-0.62, p < 0.001). After adjusting for hypertension; the Charlson comorbidity index (CCI); and medications such as angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB), anticoagulants, gemfibrozil, statins, and hypoglycemic agents, the adjusted HR was 0.75 (95% CI 0.68-0.82, p < 0.001). The need for laser treatment has an HR and adjusted HR of 0.59 (95% CI 0.49-0.71, p < 0.001) and 0.67 (95% CI 0.56-0.81, p < 0.001), respectively. Conclusion: Our study showed that the long-term and regular use of fenofibrate may decrease the risk of incident retinopathy and the need for laser treatment in type 2 diabetic patients. Since there are limitations associated with our study, further investigations are necessary to confirm such an association.
Collapse
Affiliation(s)
- Ying-Chieh Lin
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan; (Y.-C.L.); (Y.-C.C.); (J.-T.H.)
| | - Yu-Ching Chen
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan; (Y.-C.L.); (Y.-C.C.); (J.-T.H.)
| | - Jorng-Tzong Horng
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan; (Y.-C.L.); (Y.-C.C.); (J.-T.H.)
- Department of Computer Science and Information Engineering, National Central University, Chungli 32001, Taiwan
| | - Jui-Ming Chen
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan; (Y.-C.L.); (Y.-C.C.); (J.-T.H.)
- Department of Endocrinology and Metabolism, Tungs’ Taichung MetroHarbor Hospital, Taichung 43503, Taiwan
- Correspondence:
| |
Collapse
|
45
|
Menini S, Iacobini C, Vitale M, Pugliese G. The Inflammasome in Chronic Complications of Diabetes and Related Metabolic Disorders. Cells 2020; 9:cells9081812. [PMID: 32751658 PMCID: PMC7464565 DOI: 10.3390/cells9081812] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 12/14/2022] Open
Abstract
Diabetes mellitus (DM) ranks seventh as a cause of death worldwide. Chronic complications, including cardiovascular, renal, and eye disease, as well as DM-associated non-alcoholic fatty liver disease (NAFLD) account for most of the morbidity and premature mortality in DM. Despite continuous improvements in the management of late complications of DM, significant gaps remain. Therefore, searching for additional strategies to prevent these serious DM-related conditions is of the utmost importance. DM is characterized by a state of low-grade chronic inflammation, which is critical in the progression of complications. Recent clinical trials indicate that targeting the prototypic pro-inflammatory cytokine interleukin-1β (IL-1 β) improves the outcomes of cardiovascular disease, which is the first cause of death in DM patients. Together with IL-18, IL-1β is processed and secreted by the inflammasomes, a class of multiprotein complexes that coordinate inflammatory responses. Several DM-related metabolic factors, including reactive oxygen species, glyco/lipoxidation end products, and cholesterol crystals, have been involved in the pathogenesis of diabetic kidney disease, and diabetic retinopathy, and in the promoting effect of DM on the onset and progression of atherosclerosis and NAFLD. These metabolic factors are also well-established danger signals capable of regulating inflammasome activity. In addition to presenting the current state of knowledge, this review discusses how the mechanistic understanding of inflammasome regulation by metabolic danger signals may hopefully lead to novel therapeutic strategies targeting inflammation for a more effective treatment of diabetic complications.
Collapse
|
46
|
The Herbal Combination CPA4-1 Inhibits Changes in Retinal Capillaries and Reduction of Retinal Occludin in db/db Mice. Antioxidants (Basel) 2020; 9:antiox9070627. [PMID: 32708791 PMCID: PMC7402168 DOI: 10.3390/antiox9070627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 12/11/2022] Open
Abstract
Increased formation of advanced glycation end products (AGEs) plays an important role in the development of diabetic retinopathy (DR) via blood-retinal barrier (BRB) dysfunction, and reduction of AGEs has been suggested as a therapeutic target for DR. In this study, we examined whether CPA4-1, a herbal combination of Cinnamomi Ramulus and Paeoniae Radix, inhibits AGE formation. CPA4-1 and fenofibrate were tested to ameliorate changes in retinal capillaries and retinal occludin expression in db/db mice, a mouse model of obesity-induced type 2 diabetes. CPA4-1 (100 mg/kg) or fenofibrate (100 mg/kg) were orally administered once a day for 12 weeks. CPA4-1 (the half maximal inhibitory concentration, IC50 = 6.84 ± 0.08 μg/mL) showed approximately 11.44-fold higher inhibitory effect on AGE formation than that of aminoguanidine (AG, the inhibitor of AGEs, IC50 = 78.28 ± 4.24 μg/mL), as well as breaking effect on AGE-bovine serum albumin crosslinking with collagen (IC50 = 1.30 ± 0.37 μg/mL). CPA4-1 treatment ameliorated BRB leakage and tended to increase retinal occludin expression in db/db mice. CPA4-1 or fenofibrate treatment significantly reduced retinal acellular capillary formation in db/db mice. These findings suggested the potential of CPA4-1 as a therapeutic supplement for protection against retinal vascular permeability diseases.
Collapse
|
47
|
Shiono A, Sasaki H, Sekine R, Abe Y, Matsumura Y, Inagaki T, Tanaka T, Kodama T, Aburatani H, Sakai J, Takagi H. PPARα activation directly upregulates thrombomodulin in the diabetic retina. Sci Rep 2020; 10:10837. [PMID: 32616724 PMCID: PMC7331602 DOI: 10.1038/s41598-020-67579-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 06/08/2020] [Indexed: 12/19/2022] Open
Abstract
Two large clinical studies showed that fenofibrate, a commonly used peroxisome proliferator-activated receptor α (PPARα) agonist, has protective effects against diabetic retinopathy. However, the underlying mechanism has not been clarified. We performed genome-wide analyses of gene expression and PPARα binding sites in vascular endothelial cells treated with the selective PPARα modulator pemafibrate and identified 221 target genes of PPARα including THBD, which encodes thrombomodulin (TM). ChIP-qPCR and luciferase reporter analyses showed that PPARα directly regulated THBD expression via binding to the promoter. In the rat diabetic retina, treatment with pemafibrate inhibited the expression of inflammatory molecules such as VCAM-1 and MCP1, and these effects were attenuated by intravitreal injection of small interfering RNA targeted to THBD. Furthermore, pemafibrate treatment inhibited diabetes-induced vascular leukostasis and leakage through the upregulation of THBD. Our results indicate that PPARα activation inhibits inflammatory and vasopermeable responses in the diabetic retina through the upregulation of TM.
Collapse
Affiliation(s)
- Akira Shiono
- Department of Ophthalmology, St. Marianna University of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan
| | - Hiroki Sasaki
- Department of Ophthalmology, St. Marianna University of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan
| | - Reio Sekine
- Department of Ophthalmology, St. Marianna University of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan
| | - Yohei Abe
- Division of Metabolic Medicine, The University of Tokyo, RCAST, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Yoshihiro Matsumura
- Division of Metabolic Medicine, The University of Tokyo, RCAST, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Takeshi Inagaki
- Laboratory of Epigenetics and Metabolism, IMCR, Gunma University, 3-39-15 Showa-cho, Maebashi, Gunma, Japan
| | - Toshiya Tanaka
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Tatsuhiko Kodama
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Hiroyuki Aburatani
- Genome Science Division, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan
| | - Juro Sakai
- Division of Metabolic Medicine, The University of Tokyo, RCAST, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan.,Molecular Physiology and Metabolism Division, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba, Sendai, Miyagi, Japan
| | - Hitoshi Takagi
- Department of Ophthalmology, St. Marianna University of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan.
| |
Collapse
|
48
|
Yang Y, He X, Cheng R, Chen Q, Shan C, Chen L, Ma JX. Diabetes-induced upregulation of kallistatin levels exacerbates diabetic nephropathy via RAS activation. FASEB J 2020; 34:8428-8441. [PMID: 32352602 PMCID: PMC7302980 DOI: 10.1096/fj.201903149r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/28/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022]
Abstract
Kallistatin is an inhibitor of tissue kallikrein and also inhibits the Wnt pathway. Its role in diabetic nephropathy (DN) is uncertain. Here we reported that serum kallistatin levels were significantly increased in diabetic patients with DN compared to those in diabetic patients without DN and healthy controls, and positively correlated with urinary albumin excretion. In addition, renal kallistatin levels were significantly upregulated in mouse models of type 1 (Akita, OVE26) and type 2 diabetes (db/db). To unveil the effects of kallistatin on DN and its underlying mechanism, we crossed transgenic mice overexpressing kallistatin with OVE26 mice (KS‐tg/OVE). Kallistatin overexpression exacerbated albuminuria, renal fibrosis, inflammation, and oxidative stress in diabetes. Kallikrein activity was inhibited while the renin‐angiotensin system (RAS) upregulated in the kidney of KS‐tg/OVE mice compared to WT/OVE mice, suggesting a disturbed balance between the RAS and kallikrein‐kinin systems. As shown by immunostaining of endothelial makers, renal vascular densities were decreased accompanied by increased HIF‐1α and erythropoietin levels in the kidneys of KS‐tg/OVE mice. Taken together, high levels of kallistatin exacerbate DN at least partly by inducing RAS overactivation and hypoxia. The present study demonstrated a positive correlation between kallistatin levels and DN, suggesting a potential biomarker for prognosis of DN.
Collapse
Affiliation(s)
- Yanhui Yang
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Xuemin He
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Department of Endocrinology and Metabolism Diseases, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Rui Cheng
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Qian Chen
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Chunyan Shan
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
| | - Liming Chen
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, China
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| |
Collapse
|
49
|
Saad ZA, Khodeer DM, Zaitone SA, Ahmed AAM, Moustafa YM. Exenatide ameliorates experimental non-alcoholic fatty liver in rats via suppression of toll-like receptor 4/NFκB signaling: Comparison to metformin. Life Sci 2020; 253:117725. [PMID: 32348835 DOI: 10.1016/j.lfs.2020.117725] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 02/07/2023]
Abstract
AIMS Non-alcoholic fatty liver disease (NAFLD) is a common liver disease. This study aimed to evaluate the role of exenatide compared with metformin in halting the progression of fatty liver stimulated by a high-fat diet (HiFD) in rats. MAIN METHODS Thirty male Wistar rats were allocated into 6 groups, 5 rats per each group. Group I: maintained on normal diet (normal group) for fourteen weeks. The other five groups were kept on HiFD throughout the experiment, HiFD was administered beside pharmacological treatments/or vehicle. Group II: (NAFLD control group), group III: received metformin (60 mg/kg/day, P.O.), group IV-VI: received exenatide (10, 20, and 40 μg/kg/day, S.C.) respectively for 7 weeks. At the end of the therapeutic period, fasting blood glucose was determined, and body weight was registered. Rats were sacrificed, and blood samples were taken to measure serum insulin, lipids, and liver enzymes. The liver index and homeostasis model of insulin resistance (HOMA-IR) index were calculated. Further, livers were dissected for histopathological examination and Western blot analysis. KEY FINDINGS NAFLD control group showed hyperglycemia, hyperinsulinemia, increased liver enzymes, hypertriglyceridemia, elevated hepatic lipid peroxides, and inflammatory mediators (interlukin 6, nuclear factor-κB, tumor necrosis factor-α and Toll-like receptor4) in addition to hepatic fatty degeneration. In a dose-dependent manner, exenatide significantly improved most of the above mentioned markers in comparsion with NAFLD at P≤0.05. SIGNIFICANCE The current results suggest that exenatide is equivalent to metformin in controlling insulin resistance, body weight gain, improving liver function, suppressing inflammation, and attenuating NAFLD progression in male rats.
Collapse
Affiliation(s)
- Zeinab A Saad
- Medical Administration, Suez Canal University, Ismailia, Egypt
| | - Dina M Khodeer
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt.
| | - Sawsan A Zaitone
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia
| | - Amal A M Ahmed
- Department of Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt
| | - Yasser M Moustafa
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| |
Collapse
|
50
|
Wang Y, Lin W, Ju J. MicroRNA-409-5p promotes retinal neovascularization in diabetic retinopathy. Cell Cycle 2020; 19:1314-1325. [PMID: 32292119 DOI: 10.1080/15384101.2020.1749484] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Retinal neovascularization, which is characterized by the increased proliferation, migration, and tube formation of retinal microvascular endothelial cells (RMECs), contributes to the progression of diabetic retinopathy (DR). MiR-409-5p has been reported to be upregulated in peripheral blood of DR patients and in vascular endothelial growth factor (VEGF)-induced RMECs. However, the role of miR-409-5p in retinal neovascularization of DR remains unelucidated. METHOD The expression of miR-409-5p was measured in retinal tissues of streptozocin-induced and db/db diabetic mice, in high glucose-induced mouse RMECs (mRMECs), and in vitreous fluid of proliferative DR patients. Antagomir of miR-409-5p was intravitreally injected into diabetic mice. Proliferation, migration, and tube formation were detected using cell counting kit-8 assay, transwell assay, and microscope observation, respectively. Luciferase reporter assay was used to detect the direct interaction between miR-409-5p and peroxisome proliferator-activated receptor-α (PPARα). RESULT MiR-409-5p was upregulated in retinal tissues of diabetic mice, in high glucose-induced mRMECs, and in vitreous fluid of proliferative DR patients. The knockdown of miR-409-5p attenuated retinal neovascularization in vivo. The overexpression of miR-409-5p promotes the proliferation, migration, and tube formation, and increased VEGF expression and secretion, while the knockdown of miR-409-5p suppressed the VEGF-induced retinal neovascularization in vitro. PPARα is a downstream target of miR-409-5p, and PPARα overexpression negated the promotion of miR-409-5p overexpression on the proliferation, migration, and tube formation of mRMECs. CONCLUSION Our findings demonstrated that miR-409-5p acted as a neovasculogenic factor in DR, and anti-miR-409-5p therapy may provide a novel strategy in treating DR.
Collapse
Affiliation(s)
- Ying Wang
- Department of Endocrinology, Weihai Municipal Hospital , Weihai, Shandong, China
| | - Wenwen Lin
- Department of Endocrinology, Weihai Municipal Hospital , Weihai, Shandong, China
| | - Jianghua Ju
- Department of Endocrinology, Qilu Hospital of Shandong University (Qingdao) , Qingdao, Shandong, China
| |
Collapse
|