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Moldovan M, Păpurică AM, Muntean M, Bungărdean RM, Gheban D, Moldovan B, Katona G, David L, Filip GA. Effects of Gold Nanoparticles Phytoreduced with Rutin in an Early Rat Model of Diabetic Retinopathy and Cataracts. Metabolites 2023; 13:955. [PMID: 37623898 PMCID: PMC10456405 DOI: 10.3390/metabo13080955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/12/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023] Open
Abstract
Diabetic retinopathy (DR) and cataracts (CA) have an early onset in diabetes mellitus (DM) due to the redox imbalance and inflammation triggered by hyperglycaemia. Plant-based therapies are characterised by low tissue bioavailability. The study aimed to investigate the effect of gold nanoparticles phytoreduced with Rutin (AuNPsR), as a possible solution. Insulin, Rutin, and AuNPsR were administered to an early, six-week rat model of DR and CA. Oxidative stress (MDA, CAT, SOD) was assessed in serum and eye homogenates, and inflammatory cytokines (IL-1 beta, IL-6, TNF alpha) were quantified in ocular tissues. Eye fundus of retinal arterioles, transmission electron microscopy (TEM) of lenses, and histopathology of retinas were also performed. DM was linked to constricted retinal arterioles, reduced endogen antioxidants, and eye inflammation. Histologically, retinal wall thickness decreased. TEM showed increased lens opacity and fibre disorganisation. Rutin improved retinal arteriolar diameter, while reducing oxidative stress and inflammation. Retinas were moderately oedematous. Lens structure was preserved on TEM. Insulin restored retinal arteriolar diameter, while increasing MDA, and amplifying TEM lens opacity. The best outcomes were obtained for AuNPsR, as it improved fundus appearance of retinal arterioles, decreased MDA and increased antioxidant capacity. Retinal edema and disorganisation in lens fibres were still present.
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Affiliation(s)
- Mădălina Moldovan
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Clinicilor Street, No. 1, 400006 Cluj-Napoca, Romania; (A.-M.P.); (G.A.F.)
| | - Ana-Maria Păpurică
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Clinicilor Street, No. 1, 400006 Cluj-Napoca, Romania; (A.-M.P.); (G.A.F.)
| | - Mara Muntean
- Department of Cell and Molecular Biology, Iuliu Hatieganu University of Medicine and Pharmacy, Pasteur Street, No. 6, 400349 Cluj-Napoca, Romania;
| | - Raluca Maria Bungărdean
- Department of Pathology, Iuliu Hatieganu University of Medicine and Pharmacy, Clinicilor Street, No. 3-5, 400340 Cluj-Napoca, Romania; (R.M.B.); (D.G.)
| | - Dan Gheban
- Department of Pathology, Iuliu Hatieganu University of Medicine and Pharmacy, Clinicilor Street, No. 3-5, 400340 Cluj-Napoca, Romania; (R.M.B.); (D.G.)
- Department of Pathology, Emergency Clinical Hospital for Children, Motilor Street, No. 41T-42T, 400370 Cluj-Napoca, Romania
| | - Bianca Moldovan
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos Street, No. 11, 400028 Cluj-Napoca, Romania; (B.M.); (G.K.); (L.D.)
| | - Gabriel Katona
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos Street, No. 11, 400028 Cluj-Napoca, Romania; (B.M.); (G.K.); (L.D.)
| | - Luminița David
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos Street, No. 11, 400028 Cluj-Napoca, Romania; (B.M.); (G.K.); (L.D.)
| | - Gabriela Adriana Filip
- Department of Physiology, Iuliu Hatieganu University of Medicine and Pharmacy, Clinicilor Street, No. 1, 400006 Cluj-Napoca, Romania; (A.-M.P.); (G.A.F.)
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Zhang X, Huang S, Zhuang Z, Han X, Xie M, Yu S, Hua M, Liang Z, Meng C, Yin L, Zhuang X, Chen S. Lipin2 ameliorates diabetic encephalopathy via suppressing JNK/ERK-mediated NLRP3 inflammasome overactivation. Int Immunopharmacol 2023; 118:109930. [PMID: 37001383 DOI: 10.1016/j.intimp.2023.109930] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 03/31/2023]
Abstract
OBJECTIVES Diabetic encephalopathy (DE) is a common complication of diabetes in the central nervous system, which can cause cognitive dysfunction in patients. However, its pathophysiological mechanism has not been elucidated, and thus effective prevention and treatment methods are still lacking.Previous studies reported that neuroinflammation involved in the central neuropathy, while lipin2 plays an important role in inflammatory response.Therefore, we aimed to investigate the effects of lipin2 on regulating inflammatory response in the pathogenesis of DE. METHODS BV2 cells were treated with high glucose and infected with lipin2 overexpression or knockdown virus to observe the cell viability. Then, we constructed a mouse model of DE, and constructed a lipin2 knockdown or overexpression model by injecting lentivirus into the brain with stereotaxis. The expression of lipin2 in inflammatory bodies and related inflammatory factor signaling pathway-related proteins were examined by western blot and quantitative real-time PCR. Morris water maze was used to evaluate the spatial learning and memory of mice. RESULTS High glucose decreased the expression of lipin2 in BV2 cells, while overexpression of lipin2 in BV2 cells significantly suppressed the inflammatory response and apoptosis induced by high glucose. Meanwhile, the expression of lipin2 was down-regulated in the hippocampus in a DE mice model. Up-regulation of lipin2 in the hippocampus of DE mice inhibited JNK/ERK signaling pathway, reduced NLRP3 inflammasome-mediated inflammatory response, down-regulated IL-1/TNF-α expression, and improved synaptic plasticity and cognitive dysfunction in mice. Conversely, knockdown of lipin2 increased NLRP3 inflammasome overactivation, caused neuronal abnormalities and cognitive impairment in mice. CONCLUSIONS Lipin2 may play a neuroprotective role in DE by inhibiting JNK/ERK-mediated NLRP3 inflammasome overactivation and subsequent inflammatory responses. It may be a potential therapeutic target for DE therapy.
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Yang Y, Jiang G, Huang R, Liu Y, Chang X, Fu S. Targeting the NLRP3 inflammasome in diabetic retinopathy: From Pathogenesis to Therapeutic Strategies. Biochem Pharmacol 2023; 212:115569. [PMID: 37100255 DOI: 10.1016/j.bcp.2023.115569] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/16/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023]
Abstract
Diabetic retinopathy (DR) is a common diabetic microvascular complication and the main cause of vision loss in working-aged people. The NLRP3 inflammasome is a cytosolic multimeric complex that plays a significant role in innate immunity. After sensing injury, the NLRP3 inflammasome induces inflammatory mediator secretion and triggers a form of inflammatory cell death known as pyroptosis. Studies over the past five years have shown increased expression of NLRP3 and related inflammatory mediators in vitreous samples from DR patients at different clinical stages. Many NLRP3-targeted inhibitors have shown great antiangiogenic and anti-inflammatory effects in diabetes mellitus models, suggesting that the NLRP3 inflammasome is involved in the progression of DR. This review covers the molecular mechanisms of NLRP3 inflammasome activation. Furthermore, we discuss the implications of the NLRP3 inflammasome in DR, including the induction of pyroptosis and inflammation and the promotion of microangiopathy and retinal neurodegeneration. We also summarize the research progress on targeting the NLRP3 inflammasome in DR therapeutics with the expectation of providing new insights into DR progression and treatment.
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Affiliation(s)
- Yuxuan Yang
- The First Clinical Medical College, Lanzhou University, Lanzhou, The People's Republic of China, 730000
| | - Gengchen Jiang
- The First Clinical Medical College, Lanzhou University, Lanzhou, The People's Republic of China, 730000
| | - Runchun Huang
- The First Clinical Medical College, Lanzhou University, Lanzhou, The People's Republic of China, 730000
| | - Yi Liu
- The First Clinical Medical College, Lanzhou University, Lanzhou, The People's Republic of China, 730000
| | - Xingyu Chang
- The First Clinical Medical College, Lanzhou University, Lanzhou, The People's Republic of China, 730000
| | - Songbo Fu
- Department of Endocrinology, First Hospital of Lanzhou University, Lanzhou, Gansu, The People's Republic of China, 730000; Gansu Province Clinical Research Center for Endocrine Disease, Gansu, The People's Republic of China, 730000.
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Kim S, Yoneda E, Tomita K, Kayano M, Watanabe H, Sasaki M, Shimizu T, Muranishi Y. LPS Administration during Fertilization Affects Epigenetic Inheritance during Embryonic Development. Animals (Basel) 2023; 13:ani13071135. [PMID: 37048391 PMCID: PMC10093599 DOI: 10.3390/ani13071135] [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: 12/13/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Intrauterine inflammation can cause infertility by disrupting reproductive function. The pathogenesis underlying this process may primarily involve endotoxins from lipopolysaccharides (LPS), which are produced by Gram-negative bacteria. However, the long-term effects of endotoxins in mammalian pregnancy following LPS exposure during fertilization have not been clarified. In this study, we performed experiments to analyze the influence of LPS on early embryonic development and fetal development in mice. Mice uteruses were examined for the expression of genes related to the inflammatory response. The expression of Il-1β and Il-6 increased following the administration of 200 and 1000 µg/kg LPS. Exposure to LPS using in vitro fertilization (IVF) significantly decreased the embryonic developmental rate. A concentration of 100 µg/kg LPS significantly increased the placental weight and fetal crown -rump length (CRL), whereas a concentration of 200 µg/kg LPS significantly decreased the placenta weight and fetal weight in vivo. These findings indicate that maternal LPS during fertilization affects fetal development until the late stage of pregnancy. Thus, maternal endotoxins may affect epigenetic inheritance during embryonic development from the early to late stages of pregnancy.
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Affiliation(s)
- Sangwoo Kim
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Erina Yoneda
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Kisaki Tomita
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Mitsunori Kayano
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Hiroyuki Watanabe
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Motoki Sasaki
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Takashi Shimizu
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
| | - Yuki Muranishi
- Graduate School of Animal and Veterinary Sciences and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
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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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Proinflammatory Cytokines Trigger the Onset of Retinal Abnormalities and Metabolic Dysregulation in a Hyperglycemic Mouse Model. J Ophthalmol 2023; 2023:7893104. [PMID: 36895267 PMCID: PMC9991478 DOI: 10.1155/2023/7893104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 03/06/2023] Open
Abstract
Purpose Recent evidence has shown that retinal inflammation is a key player in diabetic retinopathy (DR) pathogenesis. To further understand and validate the metabolic biomarkers of DR, we investigated the effect of intravitreal proinflammatory cytokines on the retinal structure, function, and metabolism in an in vivo hyperglycemic mouse model. Methods C57Bl/6 mice were rendered hyperglycemic within one week of administration of a single high-dose intraperitoneal injection of streptozotocin, while control mice received vehicle injection. After confirming hyperglycemia, the mice received an intravitreal injection of either proinflammatory cytokines (TNF-α and IL-1β) or vehicle. Similarly, control mice received an intravitreal injection of either proinflammatory cytokines or vehicle. The retinal structure was evaluated using fundus imaging and optical coherence tomography, and retinal function was assessed using a focal electroretinogram (ERG), two days after cytokine injection. Retinas were collected for biochemical analysis to determine key metabolite levels and enzymatic activities. Results Hyperglycemic mice intraocularly injected with cytokines developed visible retinal vascular damage and intravitreal and intraretinal hyper-reflective spots two days after the cytokines injection. These mice also developed a significant functional deficit with reduced a-wave and b-wave amplitudes of the ERG at high light intensities compared to control mice. Furthermore, metabolic disruption was evident in these mice, with significantly higher retinal glucose, lactate, ATP, and glutamine levels and a significant reduction in glutamate levels compared with control mice. Minimal or no metabolic changes were observed in hyperglycemic mice without intraocular cytokines or in control mice with intraocular cytokines at 2 days post hyperglycemia. Conclusions Proinflammatory cytokines accelerated the development of vascular damage in the eyes of hyperglycemic mice. Significant changes were observed in retinal structure, function, and metabolic homeostasis. These findings support the idea that with the onset of inflammation in DR, there is a deficit in metabolism. Therefore, early intervention to prevent inflammation-induced retinal changes in diabetic patients may improve the disease outcome.
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Gao S, Zhang Y, Zhang M. Targeting Novel Regulated Cell Death: Pyroptosis, Necroptosis, and Ferroptosis in Diabetic Retinopathy. Front Cell Dev Biol 2022; 10:932886. [PMID: 35813208 PMCID: PMC9260392 DOI: 10.3389/fcell.2022.932886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/06/2022] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the primary causes of visual impairment in the working-age population. Retinal cell death is recognized as a prominent feature in the pathological changes of DR. Several types of cell death occurrence have been confirmed in DR, which might be the underlying mechanisms of retinal cell loss. Regulated cell death (RCD) originates from too intense or prolonged perturbations of the intracellular or extracellular microenvironment for adaptative responses to cope with stress and restore cellular homeostasis. Pyroptosis, necroptosis, and ferroptosis represent the novel discovered RCD forms, which contribute to retinal cell death in the pathogenesis of DR. This evidence provides new therapeutic targets for DR. In this review, we summarize the mechanisms of three types of RCD and analyse recent advances on the association between novel RCD and DR, aiming to provide new insights into the underlying pathogenic mechanisms and propose a potential new strategy for DR therapy.
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Affiliation(s)
- Sheng Gao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yun Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Meixia Zhang,
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Characterization of an Immortalized Human Microglial Cell Line as a Tool for the Study of Diabetic Retinopathy. Int J Mol Sci 2022; 23:ijms23105745. [PMID: 35628555 PMCID: PMC9145666 DOI: 10.3390/ijms23105745] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/12/2022] [Accepted: 05/19/2022] [Indexed: 12/04/2022] Open
Abstract
The complexity of the retinal structure reflects on the difficulty to describe its composite cell interactions. Microglia is responsible for the immune reaction to inflammatory stimuli during diabetic retinopathy (DR), but most studies still use rodent cells. We characterized a commercially available immortalized human microglial line and tested its susceptibility to inflammation, to study the interactions between the neuro-vascular retinal portions in species-specific models. After checking the expression of microglial markers, we tried lipopolysaccharide (LPS) stimulation and several pro-inflammatory cocktails to select the best combination able to induce a significant M1 (inflammatory) response. We measured M1 induction through the expression of pro- and anti-inflammatory molecules and performed morphologic and functional assays. Marker expression confirmed the human microglial derivation of these cells. Differently from rodents, LPS did not induce a M1 profile. The best pro-inflammatory stimulus was an interleukin-1β + tumor necrosis factor-α + interferon-γ cocktail, which induced morphology changes and increased proliferation, apoptosis, migration, reactive oxygen species, and the expression of inflammatory cytokines and miRNAs. In conclusion, this microglial line proved potentially useful to investigate the cascade of events leading to DR. In perspective, co-culture models involving microvascular cells will help in the understanding of multifaceted interactions of the neurovascular unit.
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Bushra S, Al-Sadeq DW, Bari R, Sahara A, Fadel A, Rizk N. Adiponectin Ameliorates Hyperglycemia-Induced Retinal Endothelial Dysfunction, Highlighting Pathways, Regulators, and Networks. J Inflamm Res 2022; 15:3135-3166. [PMID: 35662872 PMCID: PMC9156523 DOI: 10.2147/jir.s358594] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/04/2022] [Indexed: 12/25/2022] Open
Abstract
Background The pathophysiology of diabetic retinopathy (DR) is multifaced. A low level of circulating adiponectin (APN) in type 2 diabetes is associated with microvasculature complications, and its role in the evolution of DR is complex. Aim This study is designed to explore the potential impact of APN in the pathogenesis of DR, linking the changes in cellular and biological processes with the pathways, networks, and regulators involved in its actions. Methods Human microvascular retinal endothelial cells (HMRECs) were exposed to 30mM glucose (HG) and treated with globular adiponectin (30μg/mL) for 24 hours. The cells were evaluated for reactive oxidative stress (ROS) and apoptosis. RT-PCR profile arrays were utilized to evaluate the profile of genes involved in endothelial functions, angiogenesis, extracellular matrix, and adhesion molecules for hyperglycemic HMRECs treated with adiponectin. In addition, the barrier function, leukocyte migration, and angiogenesis were evaluated. The differential expressed genes (DEGs) were outlined, and bioinformatic analysis was applied. Results Adiponectin suppresses ROS production and apoptosis in HMRECs under HG conditions. Adiponectin improved migration and barrier functions in hyperglycemic cells. The bioinformatic analysis highlighted that the signaling pathways of integrin, HMGB1, and p38 AMPK, are mainly involved in the actions of APN on HMRECs. APN significantly affects molecular functions, including the adhesion of cells, chemotaxis, migration of WBCs, and angiogenesis. STAT3, NFKB, IKBKB, and mir-8 are the top upstream regulators, which affect the expressions of the genes of the data set, while TNF and TGFB1 are the top regulators. Conclusion Adiponectin significantly counteracts hyperglycemia at various cellular and molecular levels, reducing its impact on the pathophysiological progression towards DR in vitro using HMRECs. Adiponectin ameliorates inflammatory response, oxidative stress, and endothelial barrier dysfunction using a causal network of NFBk complex, TNF, and HMGB1 and integrin pathways.
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Affiliation(s)
- Sumbul Bushra
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
| | - Duaa W Al-Sadeq
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
| | - Redwana Bari
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
| | - Afifah Sahara
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
| | - Amina Fadel
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
| | - Nasser Rizk
- Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar
- Biomedical Research Center (BRC), Qatar University, Doha, Qatar
- Correspondence: Nasser Rizk, Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, P.O. Box 2713, Doha, Qatar, Tel +974-4403-4786, Email
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Chen T, Zhu W, Wang C, Dong X, Yu F, Su Y, Huang J, Huo L, Wan P. ALKBH5-Mediated m 6A Modification of A20 Regulates Microglia Polarization in Diabetic Retinopathy. Front Immunol 2022; 13:813979. [PMID: 35300330 PMCID: PMC8920977 DOI: 10.3389/fimmu.2022.813979] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/09/2022] [Indexed: 12/17/2022] Open
Abstract
Background To investigate the role of microglia polarization in the pathogenesis of diabetic retinopathy, and study the mechanism of ALKBH5-mediated m6A modification of A20 of retinal microglia polarization. Methods Diabetics rats were constructed and the M1/M2 polarization of retinal microglia was determined using immunofluorescence, flow cytometry, and quantitative real-time PCR (qRT-PCR). Glucose at different concentrations was added to treat the microglia, and the polarization rate was detected. RNA sequencing was performed to identify the differentially expressed gene in glucose treated microglia, and A20 expression was confirmed by qRT-PCR and western blotting. Lentiviruses encoding shRNA for A20 or overexpressing A20 were constructed to clarify the role of A20 in microglia polarization in vitro and vivo. N6-methyladenosine (m6A) modification level and degradation rate of A20 were determined and m6A related proteins were detected. Results Diabetics rats showed a higher M1 polarization rate but lower M2 polarization rate of retinal microglia. With the increase of glucose concentration, microglia tend to polarize into M1 inflammatory type rather than M2 anti-inflammatory type. Shown by RNA sequencing, glucose treated microglia showed a differentially expressed gene profile, which was enriched in kinds of inflammatory categories and pathways. A20 expression was lower in microglia with glucose treatment, which was demonstrated to negatively regulate the M1 polarization. Moreover, intraocular injection of A20-overexpression lentiviruses (OE-A20) rectified the enhanced M1 retinal microglia polarization of diabetes rats. The higher m6A modification level and faster degradation rate of A20 was observed in glucose treated microglia, which was mediated by m6A demethylase ALKBH5. Conclusion Lower expression A20 resulted in the enhanced M1 polarization of retinal microglia in diabetic retinopathy, which was caused by ALKBH5 mediated m6A modification. This study may provide new perspectives on not only the pathogenesis but also the diagnosis and treatment for diabetic retinopathy.
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Affiliation(s)
- Tingting Chen
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Wenhui Zhu
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Congyao Wang
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xia Dong
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Fenfen Yu
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yihua Su
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jingwen Huang
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lijun Huo
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Pengxia Wan
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Huang YC, Hsu SM, Shie FS, Shiao YJ, Chao LJ, Chen HW, Yao HH, Chien MA, Lin CC, Tsay HJ. Reduced mitochondria membrane potential and lysosomal acidification are associated with decreased oligomeric Aβ degradation induced by hyperglycemia: A study of mixed glia cultures. PLoS One 2022; 17:e0260966. [PMID: 35073330 PMCID: PMC8786178 DOI: 10.1371/journal.pone.0260966] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 11/20/2021] [Indexed: 01/21/2023] Open
Abstract
Diabetes is a risk factor for Alzheimer’s disease (AD), a chronic neurodegenerative disease. We and others have shown prediabetes, including hyperglycemia and obesity induced by high fat and high sucrose diets, is associated with exacerbated amyloid beta (Aβ) accumulation and cognitive impairment in AD transgenic mice. However, whether hyperglycemia reduce glial clearance of oligomeric amyloid-β (oAβ), the most neurotoxic Aβ aggregate, remains unclear. Mixed glial cultures simulating the coexistence of astrocytes and microglia in the neural microenvironment were established to investigate glial clearance of oAβ under normoglycemia and chronic hyperglycemia. Ramified microglia and low IL-1β release were observed in mixed glia cultures. In contrast, amoeboid-like microglia and higher IL-1β release were observed in primary microglia cultures. APPswe/PS1dE9 transgenic mice are a commonly used AD mouse model. Microglia close to senile plaques in APPswe/PS1dE9 transgenic mice exposed to normoglycemia or chronic hyperglycemia exhibited an amoeboid-like morphology; other microglia were ramified. Therefore, mixed glia cultures reproduce the in vivo ramified microglial morphology. To investigate the impact of sustained high-glucose conditions on glial oAβ clearance, mixed glia were cultured in media containing 5.5 mM glucose (normal glucose, NG) or 25 mM glucose (high glucose, HG) for 16 days. Compared to NG, HG reduced the steady-state level of oAβ puncta internalized by microglia and astrocytes and decreased oAβ degradation kinetics. Furthermore, the lysosomal acidification and lysosomal hydrolysis activity of microglia and astrocytes were lower in HG with and without oAβ treatment than NG. Moreover, HG reduced mitochondrial membrane potential and ATP levels in mixed glia, which can lead to reduced lysosomal function. Overall, continuous high glucose reduces microglial and astrocytic ATP production and lysosome activity which may lead to decreased glial oAβ degradation. Our study reveals diabetes-induced hyperglycemia hinders glial oAβ clearance and contributes to oAβ accumulation in AD pathogenesis.
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Affiliation(s)
- Yung-Cheng Huang
- Department of Physical Medicine and Rehabilitation, Cheng-Hsin General Hospital, Taipei, Taiwan, Republic of China
- National Taipei University of Nursing and Health Sciences, Taipei City, Taiwan, R.O.C
| | - Shu-Meng Hsu
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Feng-Shiun Shie
- Center for Neuropsychiatric Research National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan, R.O.C
| | - Young-Ji Shiao
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
- Ph.D. Program in Clinical Drug Development of Chinese Herbal Medicine, Taipei Medical University, Taipei, Taiwan, R.O.C
- Institute of Biopharmaceutical Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Li-Jung Chao
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Hui-Wen Chen
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Heng-Hsiang Yao
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Meng An Chien
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
| | - Chung-Chih Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Biophotonics Interdisciplinary Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- * E-mail: (CCL); (HJT)
| | - Huey-Jen Tsay
- Institute of Neuroscience, School of Life Science, National Yang Ming Chiao Tung University, Taipei, Taiwan, R.O.C
- Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- * E-mail: (CCL); (HJT)
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12
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Du A, Xie Y, Ouyang H, Lu B, Jia W, Xu H, Ji L. Si-Miao-Yong-An Decoction for Diabetic Retinopathy: A Combined Network Pharmacological and In Vivo Approach. Front Pharmacol 2021; 12:763163. [PMID: 34899317 PMCID: PMC8661904 DOI: 10.3389/fphar.2021.763163] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/25/2021] [Indexed: 12/21/2022] Open
Abstract
Si-Miao-Yong-An decoction (SMYAD), a traditional Chinese medicine formula, is mainly used to clear away heat and detoxify and to promote blood circulation and relieve pain. Diabetic retinopathy (DR) is the most common type of microvascular complication caused by diabetes. This study is designed to examine the protective effect of SMYAD against DR and further to reveal the engaged mechanism via integrating network pharmacology and in vivo experimental evidence. Streptozotocin (STZ) was intraperitoneally injected into mice to induce diabetes. The dysfunction of the blood retina barrier (BRB) was observed by conducting Evan's blue leakage assay, detecting tight junction (TJ) protein expression and counting the number of acellular capillaries in retinas. Our results showed that SMYAD alleviated BRB breakdown in vivo. Network pharmacology results demonstrated that regulating inflammation, immune responses, and angiogenesis might be associated with the efficacy of SMYAD in alleviating DR, in which the tumor necrosis factor (TNF) and hypoxia inducible factor 1 (HIF1) signal pathways were involved. Next, immunofluorescence staining results showed that SMYAD decreased microglia activation in retinas and reduced the enhanced adhesion of leukocytes into retinal vessels. SMYAD reduced the elevated serum TNFα content and retinal TNFα expression. SMYAD abrogated the activation of nuclear factor κB (NFκB) and HIF1α and consequently decreased the enhanced expression of some pro-inflammatory molecules and vascular endothelial growth factor (VEGF) in retinas. These results indicate that SMYAD attenuated DR development through suppressing retinal inflammation and angiogenesis via abrogating NFκB-TNFα and HIF1α-VEGF signal pathways.
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Affiliation(s)
- Ao Du
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yumin Xie
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hao Ouyang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Bin Lu
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Wangya Jia
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hong Xu
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lili Ji
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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13
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Meng C, Gu C, He S, Su T, Lhamo T, Draga D, Qiu Q. Pyroptosis in the Retinal Neurovascular Unit: New Insights Into Diabetic Retinopathy. Front Immunol 2021; 12:763092. [PMID: 34737754 PMCID: PMC8560732 DOI: 10.3389/fimmu.2021.763092] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 09/28/2021] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is prevalent among people with long-term diabetes mellitus (DM) and remains the leading cause of visual impairment in working-aged people. DR is related to chronic low-level inflammatory reactions. Pyroptosis is an emerging type of inflammatory cell death mediated by gasdermin D (GSDMD), NOD-like receptors and inflammatory caspases that promote interleukin-1β (IL-1β) and IL-18 release. In addition, the retinal neurovascular unit (NVU) is the functional basis of the retina. Recent studies have shown that pyroptosis may participate in the destruction of retinal NVU cells in simulated hyperglycemic DR environments. In this review, we will clarify the importance of pyroptosis in the retinal NVU during the development of DR.
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Affiliation(s)
- Chunren Meng
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Chufeng Gu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Shuai He
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Tong Su
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Thashi Lhamo
- Department of Ophthalmology, Shigatse People’s Hospital, Shigatse, China
| | - Deji Draga
- Department of Ophthalmology, Shigatse People’s Hospital, Shigatse, China
| | - Qinghua Qiu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
- Department of Ophthalmology, Shigatse People’s Hospital, Shigatse, China
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14
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TREM2 Regulates High Glucose-Induced Microglial Inflammation via the NLRP3 Signaling Pathway. Brain Sci 2021; 11:brainsci11070896. [PMID: 34356130 PMCID: PMC8306970 DOI: 10.3390/brainsci11070896] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/26/2021] [Accepted: 07/03/2021] [Indexed: 01/04/2023] Open
Abstract
Background: TREM2 expressed on microglia plays an important role in modulating inflammation in neurodegenerative diseases. It remains unknown whether TREM2 modulates hyperglycemia-induced microglial inflammation. Methods: We investigated the molecular function of TREM2 in high glucose-induced microglial inflammation using western blotting, qPCR, ELISA, pulldown, and co-IP methods. Results: Our data showed that in high glucose-induced BV2 cells, TREM2 was increased, and the proinflammatory cytokine IL-1β was increased. TREM2 knockout (KO) attenuated the proinflammatory cytokine IL-1β; conversely, TREM2 overexpression (OE) exacerbated IL-1β expression. Furthermore, we found that high glucose promoted the interaction of TREM2 with NLRP3. TREM2 KO abolished the interaction of TREM2 with NLRP3, while TREM2 OE enhanced the interaction. Moreover, TREM2 KO reduced high glucose-induced NLRP3 inflammasome activation, and TREM2 OE augmented high glucose-induced NLRP3 inflammasome activation, indicating that high glucose enhances the expression of TREM2, which activates the NLRP3 inflammasome. To further clarify whether the NLRP3 signaling pathway mediates the TREM2-regulated inflammatory response, we blocked the NLRP3 inflammasome by knocking out NLRP3 and treating cells with a caspase1 inhibitor, which decreased the levels of the IL-1β proinflammatory cytokine but did not affect the high glucose-induced expression of TREM2. Conclusions: TREM2 modulates high glucose-induced microglial inflammation via the NLRP3 signaling pathway.
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15
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Hammond BP, Manek R, Kerr BJ, Macauley MS, Plemel JR. Regulation of microglia population dynamics throughout development, health, and disease. Glia 2021; 69:2771-2797. [PMID: 34115410 DOI: 10.1002/glia.24047] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/20/2021] [Accepted: 05/28/2021] [Indexed: 12/11/2022]
Abstract
The dynamic expansions and contractions of the microglia population in the central nervous system (CNS) to achieve homeostasis are likely vital for their function. Microglia respond to injury or disease but also help guide neurodevelopment, modulate neural circuitry throughout life, and direct regeneration. Throughout these processes, microglia density changes, as does the volume of area that each microglia surveys. Given that microglia are responsible for sensing subtle alterations to their environment, a change in their density could affect their capacity to mobilize rapidly. In this review, we attempt to synthesize the current literature on the ligands and conditions that promote microglial proliferation across development, adulthood, and neurodegenerative conditions. Microglia display an impressive proliferative capacity during development and in neurodegenerative diseases that is almost completely absent at homeostasis. However, the appropriate function of microglia in each state is critically dependent on density fluctuations that are primarily induced by proliferation. Proliferation is a natural microglial response to insult and often serves neuroprotective functions. In contrast, inappropriate microglial proliferation, whether too much or too little, often precipitates undesirable consequences for nervous system health. Thus, fluctuations in the microglia population are tightly regulated to ensure these immune cells can execute their diverse functions.
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Affiliation(s)
- Brady P Hammond
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Rupali Manek
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada.,Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Jason R Plemel
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada.,Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Alberta, Canada
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16
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García-Bermúdez MY, Freude KK, Mouhammad ZA, van Wijngaarden P, Martin KK, Kolko M. Glial Cells in Glaucoma: Friends, Foes, and Potential Therapeutic Targets. Front Neurol 2021; 12:624983. [PMID: 33796062 PMCID: PMC8007906 DOI: 10.3389/fneur.2021.624983] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/26/2021] [Indexed: 12/15/2022] Open
Abstract
Glaucoma is the second leading cause of blindness worldwide, affecting ~80 million people by 2020 (1, 2). The condition is characterized by a progressive loss of retinal ganglion cells (RGCs) and their axons accompanied by visual field loss. The underlying pathophysiology of glaucoma remains elusive. Glaucoma is recognized as a multifactorial disease, and lowering intraocular pressure (IOP) is the only treatment that has been shown to slow the progression of the condition. However, a significant number of glaucoma patients continue to go blind despite intraocular pressure-lowering treatment (2). Thus, the need for alternative treatment strategies is indisputable. Accumulating evidence suggests that glial cells play a significant role in supporting RGC function and that glial dysfunction may contribute to optic nerve disease. Here, we review recent advances in understanding the role of glial cells in the pathophysiology of glaucoma. A particular focus is on the dynamic and essential interactions between glial cells and RGCs and potential therapeutic approaches to glaucoma by targeting glial cells.
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Affiliation(s)
| | - Kristine K Freude
- Department for Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Zaynab A Mouhammad
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Peter van Wijngaarden
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Keith K Martin
- Center for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Miriam Kolko
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet-Glostrup, Glostrup, Denmark
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17
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Shi FJ, Xie H, Zhang CY, Qin HF, Zeng XW, Lou H, Zhang L, Xu GT, Zhang JF, Xu GX. Is Iba-1 protein expression a sensitive marker for microglia activation in experimental diabetic retinopathy? Int J Ophthalmol 2021; 14:200-208. [PMID: 33614447 DOI: 10.18240/ijo.2021.02.04] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 10/10/2020] [Indexed: 12/22/2022] Open
Abstract
AIM To investigate the changes of Iba-1 and other potential markers for microglia activation in experimental diabetic retinopathy (DR). METHODS Male Sprague-Dawley rats were rendered diabetes via intraperitoneal injection of streptozotocin. The retinas were harvested at 1 to 24wk after diabetes onset. Hypoxia-treated mouse microglial cell line (BV2 cells) was employed as the in vitro model to mimic diabetic condition. The expressions of Iba-1, CD11b, ICAM-1 as well as the inflammatory factors were examined with real-time polymerase chain reaction, Western blot and immunofluorescence both in vivo and in vitro. RESULTS Compared with age-matched normal control, the number of microglia (Iba-1 positive immunostaining) in diabetic rat retinas was increased from 1 to 24wk of diabetes, which was most obvious at 12wk of diabetes. Iba-1 protein expression detected by Western blot was increased slightly in diabetic rat retinas compared with that in age-matched normal control; however, there was statistically significant between two groups only at 2wk after diabetes onset. The mRNA expression of Iba-1 was decreased significantly at 2 and 4wk of diabetic rat retinas, and remained unchanged at 8 and 12wk of diabetes. In BV2 cells, there was no significant change for the Iba-1 protein expression between normoxia and hypoxia groups; however, its mRNA level was decreased significantly under hypoxia. To further characterize microglial activation, F4/80, CD11b and inflammatory factors were detected both in vivo and in vitro. Compared with normal control, the expressions of F4/80 and CD11b as well as the inflammatory factors, such as ICAM-1, iNOS, COX2, IL-1β and IL-6, were increased significantly both in vivo and in vitro. CONCLUSION Iba-1 protein expression might not be a sensitive marker to evaluate the activation of microglia in experimental DR. However, Iba-1 immunostaining, in combination with other markers like CD11b and ICAM-1, could be well reflect the activation of microglia. Thus, it is of great importance to explore other potential marker to evaluate the activation of microglia.
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Affiliation(s)
- Fan-Jun Shi
- Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China.,Department of Ophthalmology, Changzhou Laser Hospital, Changzhou 213000, Jiangsu Province, China
| | - Hai Xie
- Tongji Eye Institute, Department of Regenerative Medicine, and Department of Pharmacology, Tongji University School of Medicine, Shanghai 200092, China
| | - Chao-Yang Zhang
- Tongji Eye Institute, Department of Regenerative Medicine, and Department of Pharmacology, Tongji University School of Medicine, Shanghai 200092, China.,Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai 200080, China.,National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai 200080, China
| | - Hai-Feng Qin
- Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China
| | - Xin-Wei Zeng
- Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China
| | - Hui Lou
- Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China
| | - Lei Zhang
- Department of Ophthalmology, Changzhou Laser Hospital, Changzhou 213000, Jiangsu Province, China
| | - Guo-Tong Xu
- Tongji Eye Institute, Department of Regenerative Medicine, and Department of Pharmacology, Tongji University School of Medicine, Shanghai 200092, China
| | - Jing-Fa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai 200080, China.,National Clinical Research Center for Eye Diseases; Shanghai Key Laboratory of Ocular Fundus Diseases; Shanghai Engineering Center for Visual Science and Photomedicine; Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai 200080, China
| | - Guo-Xu Xu
- Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China
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18
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Ta Na HS, An M, Zhang T, Deni W, Hou L, Jin K. Dexmedetomidine inhibits microglial activation through SNHG14/HMGB1 pathway in spinal cord ischemia-reperfusion injury mice. Int J Neurosci 2020; 132:77-88. [PMID: 33045891 DOI: 10.1080/00207454.2020.1835901] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Microglial activation is an essential pathological mechanism of spinal cord ischemia-reperfusion injury (SCIRI). Previous studies showed dexmedetomidine (DEX) could alleviate SCIRI while the mechanism was not clear. This study aims to investigate the role of DEX in microglial activation and clarify the underlying mechanism. METHODS The motion function of mice was quantified using the Basso Mouse Scale for Locomotion. The expression of long non-coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) was determined by qRT-PCR. The expression of high-mobility group box 1 (HMGB1) was measured by western blot. The activation of microglia was evaluated by the expression of ED-1 and the levels of TNF-α and IL-6. The interplay between SNHG14 and HMGB1 was confirmed with RNA pull-down and RIP assay. The stability of HMGB1 was measured by ubiquitination assay and cycloheximide-chase assay. RESULTS DEX inhibited microglial activation and down-regulated SNHG14 expression in SCIRI mice and oxygen and glucose deprivation/reoxygenation (OGD/R)-treated primary microglia. Functionally, SNHG14 overexpression reversed the inhibitory effect of DEX on OGD/R-induced microglial activation. Further investigation confirmed that SNHG14 bound to HMGB1, positively regulated HMGB1 expression by enhancing its stability. In addition, the silence of HMGB1 eliminated the pro-activation impact of SNHG14 overexpression on DEX-treated microglia under the OGD/R condition. Finally, in vivo experiments showed SNHG14 overexpression abrogated the therapeutic effect of DEX on SCIRI mice by up-regulating HMGB1. CONCLUSION DEX accelerated HMGB1 degradation via down-regulating SNHG14, thus inhibiting microglial activation in SCIRI mice.
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Affiliation(s)
- Ha Sen Ta Na
- Department of Anesthesiology, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia, PR China
| | - Min An
- Department of Anesthesiology, Second Affiliated Hospital of Inner Mongolia Medical College, Hohhot, Inner Mongolia, PR China
| | - Tianwen Zhang
- Department of Anesthesiology, Inner Mongolia Autonomous Region International Mongolian Hospital, Hohhot, Inner Mongolia, PR China
| | - Wuyuner Deni
- Department of Anesthesiology, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia, PR China
| | - Lichao Hou
- Department of Anesthesiology, Xiang'an Hospital of Xiamen University, Fujian, PR China
| | - Kai Jin
- Department of Anesthesiology, Xiang'an Hospital of Xiamen University, Fujian, PR China.,Department of Thyroid Neoplasms Surgery, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia, PR China
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19
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Kinuthia UM, Wolf A, Langmann T. Microglia and Inflammatory Responses in Diabetic Retinopathy. Front Immunol 2020; 11:564077. [PMID: 33240260 PMCID: PMC7681237 DOI: 10.3389/fimmu.2020.564077] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy is a vision-threatening disease affecting neurons and microvasculature of the retina. The development of this disease is associated with the action of inflammatory factors that are connected to the activation of microglial cells, the resident tissue macrophages of the CNS. In the quiescent state, microglial cells help maintain tissue homeostasis in the retina through phagocytosis and control of low-grade inflammation. However, prolonged tissue stress due to hyperglycemia primes microglia to become overly reactive with the concomitant production of pro-inflammatory cytokines and chemokines causing chronic inflammation. In this review, we provide evidence of microglial cell activation and pro-inflammatory molecules associated with the development and progression of diabetic retinopathy. We further highlight innovative animal models that can mimic the disease in humans and discuss strategies in modulating microglial-mediated inflammation as potential therapeutic approaches in managing the disease.
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Affiliation(s)
- Urbanus Muthai Kinuthia
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Anne Wolf
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Center for Molecular Medicine, University of Cologne, Cologne, Germany
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20
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Oxidative stress in the retina and retinal pigment epithelium (RPE): Role of aging, and DJ-1. Redox Biol 2020; 37:101623. [PMID: 32826201 PMCID: PMC7767746 DOI: 10.1016/j.redox.2020.101623] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/15/2022] Open
Abstract
High levels of oxidative radicals generated by daily light exposure and high metabolic rate suggest that the antioxidant machinery of the retina and retinal pigment epithelium (RPE) is crucial for their survival. DJ-1 is a redox-sensitive protein that has been shown to have neuroprotective function in the brain in Parkinson's disease and other neurodegenerative diseases. Here, we analyzed the role of DJ-1 in the retina during oxidative stress and aging. We induced low-level oxidative stress in young (3-month-old) and old (15-month-old) C57BL/6J (WT) and DJ-1 knockout (KO) mice and evaluated effects in the RPE and retina. Absence of DJ-1 resulted in increased retinal dysfunction in response to low levels of oxidative stress. Our findings suggest that loss of DJ-1 affects the RPE antioxidant machinery, rendering it unable to combat and neutralize low-level oxidative stress, irrespective of age. Moreover, they draw a parallel to the retinal degeneration observed in AMD, where the occurrence of genetic variants may leave the retina and RPE unable to fight sustained, low-levels of oxidative stress. Antioxidants are upregulated in young DJ-1 KO RPE but downregulated in the retina. DJ-1 KO retinas are degenerated under low-level oxidative stress, regardless of age. Retinas of both young C57BL and DJ-1 KO were able to regulate antioxidant genes upon low-level oxidative stress. Retinas of both aged C57BL and DJ-1 KO were unable to regulate antioxidant genes upon low-level oxidative stress. RPE of aged C57BLl mice upregulated some antioxidant genes.
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21
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Liu G, Chen X, Wang Q, Yuan L. NEK7: a potential therapy target for NLRP3-related diseases. Biosci Trends 2020; 14:74-82. [PMID: 32295992 DOI: 10.5582/bst.2020.01029] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
NLRP3 inflammasome plays an essential role in innate immunity, yet the activation mechanism of NLRP3 inflammasome is not clear. In human or animal models, inappropriate NLRP3 inflammasome activation is implicated in many NLRP3-related diseases, such as tumors, inflammatory diseases and autoimmune diseases. Until now, a great number of inhibitors have been used to disturb the related signaling pathways, such as IL-1β blockade, IL-18 blockade and caspase-1 inhibitors. Unfortunately, most of these inhibitors just disturb the signaling pathways after the activation of NLRP3 inflammasome. Inhibitors that directly regulate NLRP3 to abolish the inflammation response may be more effective. NEK7 is a multifunctional kinase affecting centrosome duplication, mitochondrial regulation, intracellular protein transport, DNA repair and mitotic spindle assembly. Researchers have made significant observations on the regulation of gene transcription or protein expression of the NLRP3 inflammasome signaling pathway by NEK7. Those signaling pathways include ROS signaling, potassium efflux, lysosomal destabilization, and NF-κB signaling. Furthermore, NEK7 has been proved to be involved in many NLRP3-related diseases in humans or in animal models. Inhibitors focused on NEK7 may regulate NLRP3 to abolish the inflammation response and NEK7 may be a potential therapeutic target for NLRP3-related diseases.
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Affiliation(s)
- Ganglei Liu
- Department of Geriatrics Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xueliang Chen
- Department of Geriatrics Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Qianqian Wang
- Department of Oncology, The Affiliated Zhuzhou Hospital of Xiangya Medical College, Central South University, Zhuzhou, Hunan, China
| | - Lianwen Yuan
- Department of Geriatrics Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
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22
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Santiago AR, Madeira MH, Boia R, Aires ID, Rodrigues-Neves AC, Santos PF, Ambrósio AF. Keep an eye on adenosine: Its role in retinal inflammation. Pharmacol Ther 2020; 210:107513. [PMID: 32109489 DOI: 10.1016/j.pharmthera.2020.107513] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adenosine is an endogenous purine nucleoside ubiquitously distributed throughout the body that interacts with G protein-coupled receptors, classified in four subtypes: A1R, A2AR, A2BR and A3R. Among the plethora of functions of adenosine, it has been increasingly recognized as a key mediator of the immune response. Neuroinflammation is a feature of chronic neurodegenerative diseases and contributes to the pathophysiology of several retinal degenerative diseases. Animal models of retinal diseases are helping to elucidate the regulatory roles of adenosine receptors in the development and progression of those diseases. Mounting evidence demonstrates that the adenosinergic system is altered in the retina during pathological conditions, compromising retinal physiology. This review focuses on the roles played by adenosine and the elements of the adenosinergic system (receptors, enzymes, transporters) in the neuroinflammatory processes occurring in the retina. An improved understanding of the molecular and cellular mechanisms of the signalling pathways mediated by adenosine underlying the onset and progression of retinal diseases will pave the way towards the identification of new therapeutic approaches.
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Affiliation(s)
- Ana Raquel Santiago
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
| | - Maria H Madeira
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal
| | - Raquel Boia
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Inês Dinis Aires
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Catarina Rodrigues-Neves
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Paulo Fernando Santos
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - António Francisco Ambrósio
- Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal; Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548 Coimbra, Portugal.
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23
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Aouiss A, Anka Idrissi D, Kabine M, Zaid Y. Update of inflammatory proliferative retinopathy: Ischemia, hypoxia and angiogenesis. Curr Res Transl Med 2019; 67:62-71. [PMID: 30685380 DOI: 10.1016/j.retram.2019.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 12/19/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023]
Abstract
Diabetic retinopathy (DR) and retinopathy of prematurity (ROP) present two examples of proliferative retinopathy, characterized by the same stages of progression; ischemia of the retinal vessels, leads to hypoxia and to correct the problem there is the setting up of uncontrolled angiogenesis, which subsequently causes blindness or even detachment of the retina. The difference is the following; that DR initiated by the metabolic complications that are due to hyperglycemia, and ROP is induced by overexposure of the neonatal retina to oxygen. In this review, we will demonstrate the physiopathological mechanism of the two forms of proliferative retinopathy DR and ROP, in particular the role of the CD40/CD40L axis and IL-1 on vascular complications and onset of inflammation of the retina, the implications of their effects on the onset of pathogenic angiogenesis, thus understanding the link between platelets and retinal ischemia. In addition, what are the therapeutic targets that could slow its progression?
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Affiliation(s)
- A Aouiss
- Laboratory of Health and Environment, Department of Biology, Faculty of Sciences Ain Chock, University of Hassan II, Casablanca, Morocco.
| | - D Anka Idrissi
- Laboratory of Health and Environment, Department of Biology, Faculty of Sciences Ain Chock, University of Hassan II, Casablanca, Morocco
| | - M Kabine
- Laboratory of Health and Environment, Department of Biology, Faculty of Sciences Ain Chock, University of Hassan II, Casablanca, Morocco
| | - Y Zaid
- Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, Montreal, H1T1C8, Quebec, Canada
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24
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Valent DJ, Wong WT, Chew EY, Cukras CA. Oral Dextromethorphan for the Treatment of Diabetic Macular Edema: Results From a Phase I/II Clinical Study. Transl Vis Sci Technol 2018; 7:24. [PMID: 30584490 PMCID: PMC6300336 DOI: 10.1167/tvst.7.6.24] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/18/2018] [Indexed: 12/14/2022] Open
Abstract
Purpose The activation of microglia, the primary innate immune cell resident in the retina, produces inflammatory mediators, which underlie changes in diabetic retinopathy including increased vascular permeability. This study evaluates the safety and efficacy of dextromethorphan, a drug capable of inhibiting microglial activation, in the treatment of diabetic macular edema (DME). Methods A single-center, prospective, open-label phase I/II clinical trial enrolled five participants with macular involving DME who received oral dextromethorphan 60 mg twice daily for 6 months as monotherapy. Main outcome variables included central retinal subfield thickness (CST), best-corrected visual acuity (BCVA), macula sensitivity, and late leakage on fluorescein angiogram (FA). Results The study drug was well tolerated. At the primary end point of 6 months, mean CST decreased by −6.3% ± 6.8% and BCVA increased by +0.6 ± 5.11 (mean ± SEM) letters. Late leakage on FA was scored as improved in four of five study eyes. These findings were not correlated with changes in hemoglobin A1c (HbA1c), creatinine, or blood pressure. Conclusions In this proof-of-concept study, dextromethorphan administration as the primary treatment for DME was associated with decreased vascular leakage, suggesting possible therapeutic effects. Additional studies investigating the modulation of microglial activation is warranted. Translational Relevance These findings highlight microglial modulation as a potentially useful therapeutic strategy in the treatment of diabetic macular edema.
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Affiliation(s)
- David J Valent
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emily Y Chew
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Catherine A Cukras
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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25
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Santiago AR, Boia R, Aires ID, Ambrósio AF, Fernandes R. Sweet Stress: Coping With Vascular Dysfunction in Diabetic Retinopathy. Front Physiol 2018; 9:820. [PMID: 30057551 PMCID: PMC6053590 DOI: 10.3389/fphys.2018.00820] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
Oxidative stress plays key roles in the pathogenesis of retinal diseases, such as diabetic retinopathy. Reactive oxygen species (ROS) are increased in the retina in diabetes and the antioxidant defense system is also compromised. Increased ROS stimulate the release of pro-inflammatory cytokines, promoting a chronic low-grade inflammation involving various signaling pathways. An excessive production of ROS can lead to retinal endothelial cell injury, increased microvascular permeability, and recruitment of inflammatory cells at the site of inflammation. Recent studies have started unraveling the complex crosstalk between retinal endothelial cells and neuroglial cells or leukocytes, via both cell-to-cell contact and secretion of cytokines. This crosstalk is essential for the maintenance of the integrity of retinal vascular structure. Under diabetic conditions, an aberrant interaction between endothelial cells and other resident cells of the retina or invading inflammatory cells takes place in the retina. Impairment in the secretion and flow of molecular signals between different cells can compromise the retinal vascular architecture and trigger angiogenesis. In this review, the synergistic contributions of redox-inflammatory processes for endothelial dysfunction in diabetic retinopathy will be examined, with particular attention paid to endothelial cell communication with other retinal cells.
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Affiliation(s)
- Ana R Santiago
- Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI, University of Coimbra, Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - Inês D Aires
- Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - António F Ambrósio
- Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI, University of Coimbra, Coimbra, Portugal
| | - Rosa Fernandes
- Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.IBILI, University of Coimbra, Coimbra, Portugal
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26
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Alves MRP, Boia R, Campos EJ, Martins J, Nunes S, Madeira MH, Santiago AR, Pereira FC, Reis F, Ambrósio AF, Baptista FI. Subtle thinning of retinal layers without overt vascular and inflammatory alterations in a rat model of prediabetes. Mol Vis 2018; 24:353-366. [PMID: 29853770 PMCID: PMC5957544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/16/2018] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Diabetic retinopathy is a neurovascular disease characterized by increased permeability of the blood-retinal barrier, changes in the neural components of the retina, and low-grade chronic inflammation. Diabetic retinopathy is a major complication of diabetes; however, the impact of a prediabetic state on the retina remains to be elucidated. The aim of this study was to assess possible early retinal changes in prediabetic rats, by evaluating changes in the integrity of the blood-retinal barrier, the retinal structure, neural markers, and inflammatory mediators. METHODS Several parameters were analyzed in the retinas of Wistar rats that drank high sucrose (HSu; 35% sucrose solution during 9 weeks, the prediabetic animal model) and were compared with those of age-matched controls. The permeability of the blood-retinal barrier was assessed with the Evans blue assay, and the content of the tight junction proteins and neural markers with western blotting. Optical coherence tomography was used to evaluate retinal thickness. Cell loss at the ganglion cell layer was assessed with terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay and by evaluating the immunoreactivity of the Brn3a transcription factor. To assess retinal neuroinflammation, the mRNA expression and protein levels of inducible nitric oxide synthase isoform (iNOS), interleukin-1 beta (IL-1β), and tumor necrosis factor (TNF) were evaluated. Iba1 and MHC-II immunoreactivity and translocator protein (TSPO) mRNA levels were assessed to study the microglial number and activation state. RESULTS The thickness of the inner retinal layers of the HSu-treated animals decreased. Nevertheless, no apoptotic cells were observed, and no changes in retinal neural markers were detected in the retinas of the HSu-treated animals. No changes were detected in the permeability of the blood-retinal barrier, as well as the tight junction protein content between the HSu-treated rats and the controls. In addition, the inflammatory parameters remained unchanged in the retina despite the tendency for an increase in the number of retinal microglial cells. CONCLUSIONS In a prediabetic rat model, the retinal structure is affected by the thinning of the inner layers, without overt vascular and inflammatory alterations. The results suggest neuronal dysfunction (thinning of the inner retina) that may precede or anticipate the vascular and inflammatory changes. Subtle structural changes might be viewed as early disturbances in an evolving disease, suggesting that preventive strategies (such as the modification of diet habits) could be applied at this stage, before the progression toward irreversible dysfunction and damage to the retina.
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Affiliation(s)
- Mariana R. P. Alves
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Raquel Boia
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Elisa J. Campos
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - João Martins
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Sara Nunes
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Maria H. Madeira
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Ana Raquel Santiago
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal,Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal
| | - Frederico C. Pereira
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - Flávio Reis
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
| | - António F. Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal,Association for Innovation and Biomedical Research on Light (AIBILI), Coimbra, Portugal
| | - Filipa I. Baptista
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal,CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal
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27
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Nadal-Nicolás FM, Jiménez-López M, Salinas-Navarro M, Sobrado-Calvo P, Vidal-Sanz M, Agudo-Barriuso M. Microglial dynamics after axotomy-induced retinal ganglion cell death. J Neuroinflammation 2017; 14:218. [PMID: 29121969 PMCID: PMC5679427 DOI: 10.1186/s12974-017-0982-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/16/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Microglial cells (MCs) are the sentries of the central nervous system. In health, they are known as surveying MCs because they examine the tissue to maintain the homeostasis. In disease, they activate and, among other functions, become phagocytic to clean the cellular debris. In this work, we have studied the behavior of rat retinal MCs in two models of unilateral complete intraorbital optic nerve axotomy which elicit a different time course of retinal ganglion cell (RGC) loss. METHODS Albino Sprague-Dawley rats were divided into these groups: (a) intact (no surgery), (b) fluorogold (FG) tracing from the superior colliculi, and (c) FG tracing + crush or transection of the left optic nerve. The retinas were dissected from 2 days to 2 months after the lesions (n = 4-12 group/lesion and time point) and then were subjected to Brn3a and Iba1 double immunodetection. In each intact retina, the total number of Brn3a+RGCs and Iba+MCs was quantified. In each traced retina (b and c groups), FG-traced RGCs and phagocytic microglial cells (PMCs, FG+Iba+) were also quantified. Topographical distribution was assessed by neighbor maps. RESULTS In intact retinas, surveying MCs are homogenously distributed in the ganglion cell layer and the inner plexiform layer. Independently of the axotomy model, RGC death occurs in two phases, one quick and one protracted, and there is a lineal and topographical correlation between the appearance of PMCs and the loss of traced RGCs. Furthermore, the clearance of FG+RGCs by PMCs occurs 3 days after the actual loss of Brn3a expression that marks RGC death. In addition, almost 50% of MCs from the inner plexiform layer migrate to the ganglion cell layer during the quick phase of RGC loss, returning to the inner plexiform layer during the slow degeneration phase. Finally, in contrast to what happens in mice, in rats, there is no microglial phagocytosis in the contralateral uninjured retina. CONCLUSIONS Axotomy-induced RGC death occurs earlier than RGC clearance and there is an inverse correlation between RGC loss and PMC appearance, both numerically and topographically, suggesting that phagocytosis occurs as a direct response to RGC death rather than to axonal damage.
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Affiliation(s)
- Francisco M Nadal-Nicolás
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain.
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain.
- Present address: Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Manuel Jiménez-López
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Manuel Salinas-Navarro
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Paloma Sobrado-Calvo
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Manuel Vidal-Sanz
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Marta Agudo-Barriuso
- Grupo de Oftalmología Experimental, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, Edificio LAIB Planta 5ª, Carretera Buenavista s/n, 30120, El Palmar, Murcia, Spain.
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Murcia, Spain.
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