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Jiang F, Lei C, Chen Y, Zhou N, Zhang M. The complement system and diabetic retinopathy. Surv Ophthalmol 2024; 69:575-584. [PMID: 38401574 DOI: 10.1016/j.survophthal.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
Diabetic retinopathy (DR) is one of the common microvascular complications of diabetes mellitus and is the main cause of visual impairment in diabetic patients. The pathogenesis of DR is still unclear. The complement system, as an important component of the innate immune system in addition to defending against the invasion of foreign microorganisms, is involved in the occurrence and development of DR through 3 widely recognized complement activation pathways, the complement regulatory system, and many other pathways. Molecules such as C3a, C5a, and membrane attacking complex, as important molecules of the complement system, are involved in the pathologenesus of DR, either through direct damaging effects or by activating cells (microglia, macroglia, etc.) in the retinal microenvironment to contribute to the pathological damage of DR indirectly. We review the integral association of the complement system and DR to further understand the pathogenesis of DR and possibly provide a new strategy for itstreatment.
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Affiliation(s)
- Feipeng Jiang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Chunyan Lei
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Yingying Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Nenghua Zhou
- Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China.
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2
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Jiang SQ, Ye SN, Huang YH, Ou YW, Chen KY, Chen JS, Tang SB. Gut microbiota induced abnormal amino acids and their correlation with diabetic retinopathy. Int J Ophthalmol 2024; 17:883-895. [PMID: 38766339 PMCID: PMC11074191 DOI: 10.18240/ijo.2024.05.13] [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: 06/05/2023] [Accepted: 02/20/2024] [Indexed: 05/22/2024] Open
Abstract
AIM To explore the correlation of gut microbiota and the metabolites with the progression of diabetic retinopathy (DR) and provide a novel strategy to elucidate the pathological mechanism of DR. METHODS The fecal samples from 32 type 2 diabetes patients with proliferative retinopathy (PDR), 23 with non-proliferative retinopathy (NPDR), 27 without retinopathy (DM), and 29 from the sex-, age- and BMI- matched healthy controls (29 HC) were analyzed by 16S rDNA gene sequencing. Sixty fecal samples from PDR, DM, and HC groups were assayed by untargeted metabolomics. Fecal metabolites were measured using liquid chromatography-mass spectrometry (LC-MS) analysis. Associations between gut microbiota and fecal metabolites were analyzed. RESULTS A cluster of 2 microbiome and 12 metabolites accompanied with the severity of DR, and the close correlation of the disease progression with PDR-related microbiome and metabolites were found. To be specific, the structure of gut microbiota differed in four groups. Diversity and richness of gut microbiota were significantly lower in PDR and NPDR groups, than those in DM and HC groups. A cluster of microbiome enriched in PDR group, including Pseudomonas, Ruminococcaceae-UCG-002, Ruminococcaceae-UCG-005, Christensenellaceae-R-7, was observed. Functional analysis showed that the glucose and nicotinate degradations were significantly higher in PDR group than those in HC group. Arginine, serine, ornithine, and arachidonic acid were significantly enriched in PDR group, while proline was enriched in HC group. Functional analysis illustrated that arginine biosynthesis, lysine degradation, histidine catabolism, central carbon catabolism in cancer, D-arginine and D-ornithine catabolism were elevated in PDR group. Correlation analysis revealed that Ruminococcaceae-UCG-002 and Christensenellaceae-R-7 were positively associated with L-arginine, ornithine levels in fecal samples. CONCLUSION This study elaborates the different microbiota structure in the gut from four groups. The relative abundance of Ruminococcaceae-UCG-002 and Parabacteroides are associated with the severity of DR. Amino acid and fatty acid catabolism is especially disordered in PDR group. This may help provide a novel diagnostic parameter for DR, especially PDR.
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Affiliation(s)
- Sheng-Qun Jiang
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
- The First Affiliated Hospital of Bengbu Medical University, Bengbu 233000, Anhui Province, China
| | - Su-Na Ye
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
| | - Yin-Hua Huang
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
| | - Yi-Wen Ou
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
| | - Ke-Yang Chen
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
- School of Public Health, Anhui Medical University, Hefei 230000, Anhui Province, China
| | - Jian-Su Chen
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
| | - Shi-Bo Tang
- Aier Eye Hospital, Jinan University, Guangzhou 510000, Guangdong Province, China
- Aier Eye Institute and Changsha Aier Hospital, Changsha 410000, Hunan Province, China
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Shahror RA, Morris CA, Mohammed AA, Wild M, Zaman B, Mitchell CD, Phillips PH, Rusch NJ, Shosha E, Fouda AY. Role of myeloid cells in ischemic retinopathies: recent advances and unanswered questions. J Neuroinflammation 2024; 21:65. [PMID: 38454477 PMCID: PMC10918977 DOI: 10.1186/s12974-024-03058-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/28/2024] [Indexed: 03/09/2024] Open
Abstract
Myeloid cells including microglia and macrophages play crucial roles in retinal homeostasis by clearing cellular debris and regulating inflammation. These cells are activated in several blinding ischemic retinal diseases including diabetic retinopathy, where they may exert both beneficial and detrimental effects on neurovascular function and angiogenesis. Myeloid cells impact the progression of retinal pathologies and recent studies suggest that targeting myeloid cells is a promising therapeutic strategy to mitigate diabetic retinopathy and other ischemic retinal diseases. This review summarizes the recent advances in our understanding of the role of microglia and macrophages in retinal diseases and focuses on the effects of myeloid cells on neurovascular injury and angiogenesis in ischemic retinopathies. We highlight gaps in knowledge and advocate for a more detailed understanding of the role of myeloid cells in retinal ischemic injury to fully unlock the potential of targeting myeloid cells as a therapeutic strategy for retinal ischemia.
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Affiliation(s)
- Rami A Shahror
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Carol A Morris
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Aya A Mohammed
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Melissa Wild
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Bushra Zaman
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Christian D Mitchell
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Paul H Phillips
- Department of Ophthalmology, Harvey & Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Nancy J Rusch
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Esraa Shosha
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
- Clinical Pharmacy Department, Cairo University, Cairo, Egypt
| | - Abdelrahman Y Fouda
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA.
- Clinical Pharmacy Department, Cairo University, Cairo, Egypt.
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Wang X, Li X, Zong Y, Yu J, Chen Y, Zhao M, Wu D, Liao Y, Jiang C, Zhu H. Identification and Validation of Genes Related to RNA Methylation Modification in Diabetic Retinopathy. Curr Eye Res 2023; 48:1034-1049. [PMID: 37529844 DOI: 10.1080/02713683.2023.2238144] [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: 05/11/2023] [Accepted: 07/13/2023] [Indexed: 08/03/2023]
Abstract
PURPOSE To identify and validate the differentially expressed genes related to RNA methylation modification in diabetic retinopathy. METHODS The data sets GSE12610 and GSE111465 related to diabetic retinopathy in the Gene Expression Omnibus were selected. The R software package was used to identify differentially expressed genes related to RNA methylation modification in diabetic retinopathy. Protein-protein interaction network was constructed to explore the interactions between proteins and predict proteins. Then, Gene Ontology annotation analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were used to analyze the potential enrichment pathways and clarify the biological functions of these genes. In addition, the correlation between them and immune cells was visualized, and receiver operating characteristic curves were drawn to evaluate the diagnostic performance of each one of them for diabetic retinopathy. To verify the differentially expressed genes, the mRNA expression of rat retinal vascular endothelial cells cultured in low and high glucose medium separately were detected by RT-qPCR. RESULTS The expression of Lrpprc, Nsun4, Nsun6 and Trdmt1 were significantly up-regulated in diabetic retinopathy samples, while the expression of Cbll1, Hnrnpc, Mettl3 and Wtap were significantly down-regulated. Differentially expressed genes were mainly enriched in the RNA-methylation-medication pathways and biological function. The results of immune infiltration analysis proved that eosinophils aggregated more in diabetic group, while T cells follicular helper aggregated more in normal samples. These genes of Cbll1 (AUC = 0.986), Hnrnpc (AUC = 0.819), Lrpprc (AUC = 0.806), Mettl3 (AUC = 0.917), Nsun4 (AUC = 0.819), Nsun6 (AUC = 0.819), Trdmt1 (AUC = 0.972) and Wtap (AUC = 0.972) were respectively used as the diagnostic basis of diabetic retinopathy. According to the RT-qPCR results, the expression of Mettl3 was significantly down-regulated (p < 0.0005) in cells cultured in high glucose, while Trdmt1 (p < 0.05), Nsun4 (p < 0.05) and Nsun6 (p < 0.05) were significantly up-regulated. CONCLUSION Differentially expressed genes such as Mettl3, Nsun4, Nsun6, and Trdmt1 should be conducted to explore, and the role of RNA methylation in the process of diabetic retinopathy would be revealed in-depth.
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Affiliation(s)
- Xue Wang
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Xiaomei Li
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Yuan Zong
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China
| | - Jian Yu
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China
| | - Yan Chen
- Department of Ophthalmology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Minghui Zhao
- Department of Ophthalmology, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Danping Wu
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Yujie Liao
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Chunhui Jiang
- Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China
| | - Haohao Zhu
- Department of Ophthalmology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
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Vargas-Soria M, García-Alloza M, Corraliza-Gómez M. Effects of diabetes on microglial physiology: a systematic review of in vitro, preclinical and clinical studies. J Neuroinflammation 2023; 20:57. [PMID: 36869375 PMCID: PMC9983227 DOI: 10.1186/s12974-023-02740-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/16/2023] [Indexed: 03/05/2023] Open
Abstract
Diabetes mellitus is a heterogeneous chronic metabolic disorder characterized by the presence of hyperglycemia, commonly preceded by a prediabetic state. The excess of blood glucose can damage multiple organs, including the brain. In fact, cognitive decline and dementia are increasingly being recognized as important comorbidities of diabetes. Despite the largely consistent link between diabetes and dementia, the underlying causes of neurodegeneration in diabetic patients remain to be elucidated. A common factor for almost all neurological disorders is neuroinflammation, a complex inflammatory process in the central nervous system for the most part orchestrated by microglial cells, the main representatives of the immune system in the brain. In this context, our research question aimed to understand how diabetes affects brain and/or retinal microglia physiology. We conducted a systematic search in PubMed and Web of Science to identify research items addressing the effects of diabetes on microglial phenotypic modulation, including critical neuroinflammatory mediators and their pathways. The literature search yielded 1327 records, including 18 patents. Based on the title and abstracts, 830 papers were screened from which 250 primary research papers met the eligibility criteria (original research articles with patients or with a strict diabetes model without comorbidities, that included direct data about microglia in the brain or retina), and 17 additional research papers were included through forward and backward citations, resulting in a total of 267 primary research articles included in the scoping systematic review. We reviewed all primary publications investigating the effects of diabetes and/or its main pathophysiological traits on microglia, including in vitro studies, preclinical models of diabetes and clinical studies on diabetic patients. Although a strict classification of microglia remains elusive given their capacity to adapt to the environment and their morphological, ultrastructural and molecular dynamism, diabetes modulates microglial phenotypic states, triggering specific responses that include upregulation of activity markers (such as Iba1, CD11b, CD68, MHC-II and F4/80), morphological shift to amoeboid shape, secretion of a wide variety of cytokines and chemokines, metabolic reprogramming and generalized increase of oxidative stress. Pathways commonly activated by diabetes-related conditions include NF-κB, NLRP3 inflammasome, fractalkine/CX3CR1, MAPKs, AGEs/RAGE and Akt/mTOR. Altogether, the detailed portrait of complex interactions between diabetes and microglia physiology presented here can be regarded as an important starting point for future research focused on the microglia-metabolism interface.
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Affiliation(s)
- María Vargas-Soria
- Division of Physiology, School of Medicine, Universidad de Cadiz, Cadiz, Spain.,Instituto de Investigacion e Innovacion en Ciencias Biomedicas de la Provincia de Cadiz (INIBICA), Cadiz, Spain
| | - Mónica García-Alloza
- Division of Physiology, School of Medicine, Universidad de Cadiz, Cadiz, Spain.,Instituto de Investigacion e Innovacion en Ciencias Biomedicas de la Provincia de Cadiz (INIBICA), Cadiz, Spain
| | - Miriam Corraliza-Gómez
- Division of Physiology, School of Medicine, Universidad de Cadiz, Cadiz, Spain. .,Instituto de Investigacion e Innovacion en Ciencias Biomedicas de la Provincia de Cadiz (INIBICA), Cadiz, Spain.
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Ren Y, Li Z, Li W, Fan X, Han F, Huang Y, Yu Y, Qian L, Xiong Y. Arginase: Biological and Therapeutic Implications in Diabetes Mellitus and Its Complications. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:2419412. [PMID: 36338341 PMCID: PMC9629921 DOI: 10.1155/2022/2419412] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/18/2022] [Indexed: 09/21/2023]
Abstract
Arginase is a ubiquitous enzyme in the urea cycle (UC) that hydrolyzes L-arginine to urea and L-ornithine. Two mammalian arginase isoforms, arginase1 (ARG1) and arginase2 (ARG2), play a vital role in the regulation of β-cell functions, insulin resistance (IR), and vascular complications via modulating L-arginine metabolism, nitric oxide (NO) production, and inflammatory responses as well as oxidative stress. Basic and clinical studies reveal that abnormal alterations of arginase expression and activity are strongly associated with the onset and development of diabetes mellitus (DM) and its complications. As a result, targeting arginase may be a novel and promising approach for DM treatment. An increasing number of arginase inhibitors, including chemical and natural inhibitors, have been developed and shown to protect against the development of DM and its complications. In this review, we discuss the fundamental features of arginase. Next, the regulatory roles and underlying mechanisms of arginase in the pathogenesis and progression of DM and its complications are explored. Furthermore, we review the development and discuss the challenges of arginase inhibitors in treating DM and its related pathologies.
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Affiliation(s)
- Yuanyuan Ren
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, Shaanxi, China
| | - Zhuozhuo Li
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, Shaanxi, China
| | - Wenqing Li
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
| | - Xiaobin Fan
- Department of Obstetrics and Gynecology, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Xi'an, Shaanxi, China
| | - Feifei Han
- Department of Endocrinology, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Xi'an, Shaanxi, China
| | - Yaoyao Huang
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
| | - Yi Yu
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, Shaanxi, China
| | - Lu Qian
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
- Department of Obstetrics and Gynecology, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Xi'an, Shaanxi, China
| | - Yuyan Xiong
- Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No.3 Hospital, The Affiliated Hospital of Northwest University, Faculty of Life Sciences and Medicine, Northwest University, Xi'an, Shaanxi, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, Shaanxi, China
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Abdelrahman AA, Bunch KL, Sandow PV, Cheng PNM, Caldwell RB, Caldwell RW. Systemic Administration of Pegylated Arginase-1 Attenuates the Progression of Diabetic Retinopathy. Cells 2022; 11:cells11182890. [PMID: 36139465 PMCID: PMC9497170 DOI: 10.3390/cells11182890] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 12/02/2022] Open
Abstract
Diabetic retinopathy (DR) is a serious complication of diabetes that results from sustained hyperglycemia, hyperlipidemia, and oxidative stress. Under these conditions, inducible nitric oxide synthase (iNOS) expression is upregulated in the macrophages (MΦ) and microglia, resulting in increased production of reactive oxygen species (ROS) and inflammatory cytokines, which contribute to disease progression. Arginase 1 (Arg1) is a ureohydrolase that competes with iNOS for their common substrate, L-arginine. We hypothesized that the administration of a stable form of Arg1 would deplete L-arginine’s availability for iNOS, thus decreasing inflammation and oxidative stress in the retina. Using an obese Type 2 diabetic (T2DM) db/db mouse, this study characterized DR in this model and determined if systemic treatment with pegylated Arg1 (PEG-Arg1) altered the progression of DR. PEG-Arg1 treatment of db/db mice thrice weekly for two weeks improved visual function compared with untreated db/db controls. Retinal expression of inflammatory factors (iNOS, IL-1β, TNF-α, IL-6) was significantly increased in the untreated db/db mice compared with the lean littermate controls. The increased retinal inflammatory and oxidative stress markers in db/db mice were suppressed with PEG-Arg1 treatment. Additionally, PEG-Arg1 treatment restored the blood–retinal barrier (BRB) function, as evidenced by the decreased tissue albumin extravasation and an improved endothelial ZO-1 tight junction integrity compared with untreated db/db mice.
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Affiliation(s)
- Ammar A. Abdelrahman
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Katharine L. Bunch
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Porsche V. Sandow
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Paul N-M Cheng
- Bio-Cancer Treatment International, Bioinformatics Building, Hong Kong Science Park, Tai Po, Hong Kong SAR 511513, China
| | - Ruth B. Caldwell
- Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Department of Cell Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - R. William Caldwell
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Correspondence: ; Tel.: +1-706-721-2345
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Chauhan MZ, Rather PA, Samarah SM, Elhusseiny AM, Sallam AB. Current and Novel Therapeutic Approaches for Treatment of Diabetic Macular Edema. Cells 2022; 11:cells11121950. [PMID: 35741079 PMCID: PMC9221813 DOI: 10.3390/cells11121950] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 12/13/2022] Open
Abstract
Diabetic macular edema (DME) is a major ocular complication of diabetes mellitus (DM), leading to significant visual impairment. DME’s pathogenesis is multifactorial. Focal edema tends to occur when primary metabolic abnormalities lead to a persistent hyperglycemic state, causing the development of microaneurysms, often with extravascular lipoprotein in a circinate pattern around the focal leakage. On the other hand, diffusion edema is due to a generalized breakdown of the inner blood–retinal barrier, leading to profuse early leakage from the entire capillary bed of the posterior pole with the subsequent extravasation of fluid into the extracellular space. The pathogenesis of DME occurs through the interaction of multiple molecular mediators, including the overexpression of several growth factors, including vascular endothelial growth factor (VEGF), insulin-like growth factor-1, angiopoietin-1, and -2, stromal-derived factor-1, fibroblast growth factor-2, and tumor necrosis factor. Synergistically, these growth factors mediate angiogenesis, protease production, endothelial cell proliferation, and migration. Treatment for DME generally involves primary management of DM, laser photocoagulation, and pharmacotherapeutics targeting mediators, namely, the anti-VEGF pathway. The emergence of anti-VEGF therapies has resulted in significant clinical improvements compared to laser therapy alone. However, multiple factors influencing the visual outcome after anti-VEGF treatment and the presence of anti-VEGF non-responders have necessitated the development of new pharmacotherapies. In this review, we explore the pathophysiology of DME and current management strategies. In addition, we provide a comprehensive analysis of emerging therapeutic approaches to the treatment of DME.
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Affiliation(s)
- Muhammad Z. Chauhan
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.Z.C.); (P.A.R.); (S.M.S.); (A.M.E.)
- Miami Integrative Metabolomics Research Center, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA
| | - Peyton A. Rather
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.Z.C.); (P.A.R.); (S.M.S.); (A.M.E.)
| | - Sajida M. Samarah
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.Z.C.); (P.A.R.); (S.M.S.); (A.M.E.)
| | - Abdelrahman M. Elhusseiny
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.Z.C.); (P.A.R.); (S.M.S.); (A.M.E.)
| | - Ahmed B. Sallam
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.Z.C.); (P.A.R.); (S.M.S.); (A.M.E.)
- Correspondence: ; Tel.: +501-686-5822; Fax: +501-686-7037
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9
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Bunch KL, Abdelrahman AA, Caldwell RB, Caldwell RW. Novel Therapeutics for Diabetic Retinopathy and Diabetic Macular Edema: A Pathophysiologic Perspective. Front Physiol 2022; 13:831616. [PMID: 35250632 PMCID: PMC8894892 DOI: 10.3389/fphys.2022.831616] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/17/2022] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy (DR) and diabetic macular edema (DME) are retinal complications of diabetes that can lead to loss of vision and impaired quality of life. The current gold standard therapies for treatment of DR and DME focus on advanced disease, are invasive, expensive, and can trigger adverse side-effects, necessitating the development of more effective, affordable, and accessible therapies that can target early stage disease. The pathogenesis and pathophysiology of DR is complex and multifactorial, involving the interplay between the effects of hyperglycemia, hyperlipidemia, hypoxia, and production of reactive oxygen species (ROS) in the promotion of neurovascular dysfunction and immune cell polarization to a proinflammatory state. The pathophysiology of DR provides several therapeutic targets that have the potential to attenuate disease progression. Current novel DR and DME therapies under investigation include erythropoietin-derived peptides, inducers of antioxidant gene expression, activators of nitric oxide/cyclic GMP signaling pathways, and manipulation of arginase activity. This review aims to aid understanding of DR and DME pathophysiology and explore novel therapies that capitalize on our knowledge of these diabetic retinal complications.
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Affiliation(s)
- Katharine L. Bunch
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Ammar A. Abdelrahman
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Ruth B. Caldwell
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - R. William Caldwell
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, United States
- *Correspondence: R. William Caldwell,
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Kambis TN, Tofilau HMN, Gawargi FI, Chandra S, Mishra PK. Regulating Polyamine Metabolism by miRNAs in Diabetic Cardiomyopathy. Curr Diab Rep 2021; 21:52. [PMID: 34902085 PMCID: PMC8668854 DOI: 10.1007/s11892-021-01429-w] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/22/2021] [Indexed: 11/08/2022]
Abstract
PURPOSE OF REVIEW Insulin is at the heart of diabetes mellitus (DM). DM alters cardiac metabolism causing cardiomyopathy, ultimately leading to heart failure. Polyamines, organic compounds synthesized by cardiomyocytes, have an insulin-like activity and effect on glucose metabolism, making them metabolites of interest in the DM heart. This review sheds light on the disrupted microRNA network in the DM heart in relation to developing novel therapeutics targeting polyamine biosynthesis to prevent/mitigate diabetic cardiomyopathy. RECENT FINDINGS Polyamines prevent DM-induced upregulation of glucose and ketone body levels similar to insulin. Polyamines also enhance mitochondrial respiration and thereby regulate all major metabolic pathways. Non-coding microRNAs regulate a majority of the biological pathways in our body by modulating gene expression via mRNA degradation or translational repression. However, the role of miRNA in polyamine biosynthesis in the DM heart remains unclear. This review discusses the regulation of polyamine synthesis and metabolism, and its impact on cardiac metabolism and circulating levels of glucose, insulin, and ketone bodies. We provide insights on potential roles of polyamines in diabetic cardiomyopathy and putative miRNAs that could regulate polyamine biosynthesis in the DM heart. Future studies will unravel the regulatory roles these miRNAs play in polyamine biosynthesis and will open new doors in the prevention/treatment of adverse cardiac remodeling in diabetic cardiomyopathy.
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Affiliation(s)
- Tyler N Kambis
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | | | - Flobater I Gawargi
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Surabhi Chandra
- Department of Biology, University of Nebraska-Kearney, Kearney, NE, 68845, USA
| | - Paras K Mishra
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Clarkson-Townsend DA, Bales KL, Marsit CJ, Pardue MT. Light Environment Influences Developmental Programming of the Metabolic and Visual Systems in Mice. Invest Ophthalmol Vis Sci 2021; 62:22. [PMID: 33861321 PMCID: PMC8083116 DOI: 10.1167/iovs.62.4.22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/27/2021] [Indexed: 02/06/2023] Open
Abstract
Purpose Light is a salient cue that can influence neurodevelopment and the immune system. Light exposure out of sync with the endogenous clock causes circadian disruption and chronic disease. Environmental light exposure may contribute to developmental programming of metabolic and neurological systems but has been largely overlooked in Developmental Origins of Health and Disease (DOHaD) research. Here, we investigated whether developmental light exposure altered programming of visual and metabolic systems. Methods Pregnant mice and pups were exposed to control light (12:12 light:dark) or weekly light cycle inversions (circadian disruption [CD]) until weaning, after which male and female offspring were housed in control light and longitudinally measured to evaluate differences in growth (weight), glucose tolerance, visual function (optomotor response), and retinal function (electroretinogram), with and without high fat diet (HFD) challenge. Retinal microglia and macrophages were quantified by positive Iba1 and CD11b immunofluorescence. Results CD exposure caused impaired visual function and increased retinal immune cell expression in adult offspring. When challenged with HFD, CD offspring also exhibited altered retinal function and sex-specific impairments in glucose tolerance. Conclusions Overall, these findings suggest that the light environment contributes to developmental programming of the metabolic and visual systems, potentially promoting a pro-inflammatory milieu in the retina and increasing the risk of visual disease later in life.
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Affiliation(s)
- Danielle A. Clarkson-Townsend
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, Georgia, United States
| | - Katie L. Bales
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, Georgia, United States
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Carmen J. Marsit
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States
| | - Machelle T. Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, Georgia, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
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Clarkson-Townsend DA, Douglass AJ, Singh A, Allen RS, Uwaifo IN, Pardue MT. Impacts of high fat diet on ocular outcomes in rodent models of visual disease. Exp Eye Res 2021; 204:108440. [PMID: 33444582 PMCID: PMC7946735 DOI: 10.1016/j.exer.2021.108440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
High fat diets (HFD) have been utilized in rodent models of visual disease for over 50 years to model the effects of lipids, metabolic dysfunction, and diet-induced obesity on vision and ocular health. HFD treatment can recapitulate the pathologies of some of the leading causes of blindness, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rodent models of visual disease. However, there are many important factors to consider when using and interpreting these models. To synthesize our current understanding of the importance of lipid signaling, metabolism, and inflammation in HFD-driven visual disease processes, we systematically review the use of HFD in mouse and rat models of visual disease. The resulting literature is grouped into three clusters: models that solely focus on HFD treatment, models of diabetes that utilize both HFD and streptozotocin (STZ), and models of AMD that utilize both HFD and genetic models and/or other exposures. Our findings show that HFD profoundly affects vision, retinal function, many different ocular tissues, and multiple cell types through a variety of mechanisms. We delineate how HFD affects the cornea, lens, uvea, vitreous humor, retina, retinal pigmented epithelium (RPE), and Bruch's membrane (BM). Furthermore, we highlight how HFD impairs several retinal cell types, including glia (microglia), retinal ganglion cells, bipolar cells, photoreceptors, and vascular support cells (endothelial cells and pericytes). However, there are a number of gaps, limitations, and biases in the current literature. We highlight these gaps and discuss experimental design to help guide future studies. Very little is known about how HFD impacts the lens, ciliary bodies, and specific neuronal populations, such as rods, cones, bipolar cells, amacrine cells, and retinal ganglion cells. Additionally, sex bias is an important limitation in the current literature, with few HFD studies utilizing female rodents. Future studies should use ingredient-matched control diets (IMCD), include both sexes in experiments to evaluate sex-specific outcomes, conduct longitudinal metabolic and visual measurements, and capture acute outcomes. In conclusion, HFD is a systemic exposure with profound systemic effects, and rodent models are invaluable in understanding the impacts on visual and ocular disease.
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Affiliation(s)
- Danielle A Clarkson-Townsend
- Gangarosa Department of Environmental Health, Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Amber J Douglass
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Anayesha Singh
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Emory Center for Ethics, Emory University, Atlanta, GA, USA
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Ivie N Uwaifo
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Neuroscience, Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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The innate immune system in diabetic retinopathy. Prog Retin Eye Res 2021; 84:100940. [PMID: 33429059 DOI: 10.1016/j.preteyeres.2021.100940] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.
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Is the Arginase Pathway a Novel Therapeutic Avenue for Diabetic Retinopathy? J Clin Med 2020; 9:jcm9020425. [PMID: 32033258 PMCID: PMC7073619 DOI: 10.3390/jcm9020425] [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: 01/21/2020] [Accepted: 01/31/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy (DR) is the leading cause of blindness in working age Americans. Clinicians diagnose DR based on its characteristic vascular pathology, which is evident upon clinical exam. However, extensive research has shown that diabetes causes significant neurovascular dysfunction prior to the development of clinically apparent vascular damage. While laser photocoagulation and/or anti-vascular endothelial growth factor (VEGF) therapies are often effective for limiting the late-stage vascular pathology, we still do not have an effective treatment to limit the neurovascular dysfunction or promote repair during the early stages of DR. This review addresses the role of arginase as a mediator of retinal neurovascular injury and therapeutic target for early stage DR. Arginase is the ureohydrolase enzyme that catalyzes the production of L-ornithine and urea from L-arginine. Arginase upregulation has been associated with inflammation, oxidative stress, and peripheral vascular dysfunction in models of both types of diabetes. The arginase enzyme has been identified as a therapeutic target in cardiovascular disease and central nervous system disease including stroke and ischemic retinopathies. Here, we discuss and review the literature on arginase-induced retinal neurovascular dysfunction in models of DR. We also speculate on the therapeutic potential of arginase in DR and its related underlying mechanisms.
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