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Cen K, Huang Y, Xie Y, Liu Y. The guardian of intracranial vessels: Why the pericyte? Biomed Pharmacother 2024; 176:116870. [PMID: 38850658 DOI: 10.1016/j.biopha.2024.116870] [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: 03/02/2024] [Revised: 05/27/2024] [Accepted: 06/03/2024] [Indexed: 06/10/2024] Open
Abstract
Intracranial atherosclerotic stenosis (ICAS) is a pathological condition characterized by progressive narrowing or complete blockage of intracranial blood vessels caused by plaque formation. This condition leads to reduced blood flow to the brain, resulting in cerebral ischemia and hypoxia. Ischemic stroke (IS) resulting from ICAS poses a significant global public health challenge, especially among East Asian populations. However, the underlying causes of the notable variations in prevalence among diverse populations, as well as the most effective strategies for preventing and treating the rupture and blockage of intracranial plaques, remain incompletely comprehended. Rupture of plaques, bleeding, and thrombosis serve as precipitating factors in the pathogenesis of luminal obstruction in intracranial arteries. Pericytes play a crucial role in the structure and function of blood vessels and face significant challenges in regulating the Vasa Vasorum (VV)and preventing intraplaque hemorrhage (IPH). This review aims to explore innovative therapeutic strategies that target the pathophysiological mechanisms of vulnerable plaques by modulating pericyte biological function. It also discusses the potential applications of pericytes in central nervous system (CNS) diseases and their prospects as a therapeutic intervention in the field of biological tissue engineering regeneration.
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Affiliation(s)
- Kuan Cen
- Department of Neurology, Zhongnan Hospital Affiliated to Wuhan University, Wuhan 430000, China
| | - YinFei Huang
- Department of Neurology, Zhongnan Hospital Affiliated to Wuhan University, Wuhan 430000, China
| | - Yu Xie
- Department of Neurology, Zhongnan Hospital Affiliated to Wuhan University, Wuhan 430000, China
| | - YuMin Liu
- Department of Neurology, Zhongnan Hospital Affiliated to Wuhan University, Wuhan 430000, China.
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Zhang Q, Yan X, Han H, Wang Y, Sun J. Pericyte in retinal vascular diseases: A multifunctional regulator and potential therapeutic target. FASEB J 2024; 38:e23679. [PMID: 38780117 DOI: 10.1096/fj.202302624r] [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: 12/19/2023] [Revised: 04/17/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024]
Abstract
Retinal vascular diseases (RVDs), in particular diabetic retinopathy, retinal vein occlusion, and retinopathy of prematurity, are leading contributors to blindness. The pathogenesis of RVD involves vessel dilatation, leakage, and occlusion; however, the specific underlying mechanisms remain unclear. Recent findings have indicated that pericytes (PCs), as critical members of the vascular mural cells, significantly contribute to the progression of RVDs, including detachment from microvessels, alteration of contractile and secretory properties, and excessive production of the extracellular matrix. Moreover, PCs are believed to have mesenchymal stem properties and, therefore, might contribute to regenerative therapy. Here, we review novel ideas concerning PC characteristics and functions in RVDs and discuss potential therapeutic strategies based on PCs, including the targeting of pathological signals and cell-based regenerative treatments.
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Affiliation(s)
- Quan Zhang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Xianchun Yan
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Hua Han
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Yusheng Wang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Jiaxing Sun
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
- Department of Neurobiology, Air Force Medical University, Xi'an, China
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Choudhary M, Tayyari F, Handa JT, Malek G. Characterization and identification of measurable endpoints in a mouse model featuring age-related retinal pathologies: a platform to test therapies. J Transl Med 2022; 102:1132-1142. [PMID: 36775353 PMCID: PMC10041606 DOI: 10.1038/s41374-022-00795-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/13/2022] [Accepted: 04/18/2022] [Indexed: 11/09/2022] Open
Abstract
Apolipoprotein B100 (apoB100) is the structural protein of cholesterol carriers including low-density lipoproteins. It is a constituent of sub-retinal pigment epithelial (sub-RPE) deposits and pro-atherogenic plaques, hallmarks of early dry age-related macular degeneration (AMD), an ocular neurodegenerative blinding disease, and cardiovascular disease, respectively. Herein, we characterized the retinal pathology of transgenic mice expressing mouse apoB100 in order to catalog their functional and morphological ocular phenotypes as a function of age and establish measurable endpoints for their use as a mouse model to test potential therapies. ApoB100 mice were found to exhibit an age-related decline in retinal function, as measured by electroretinogram (ERG) recordings of their scotopic a-wave, scotopic b-wave; and c-wave amplitudes. ApoB100 mice also displayed a buildup of the cholesterol carrier, apolipoprotein E (apoE) within and below the supporting extracellular matrix, Bruch's membrane (BrM), along with BrM thickening, and accumulation of thin diffuse electron-dense sub-RPE deposits, the severity of which increased with age. Moreover, the combination of apoB100 and advanced age were found to be associated with RPE morphological changes and the presence of sub-retinal immune cells as visualized in RPE-choroid flatmounts. Finally, aged apoB100 mice showed higher levels of circulating and ocular pro-inflammatory cytokines, supporting a link between age and increased local and systemic inflammation. Collectively, the data support the use of aged apoB100 mice as a platform to evaluate potential therapies for retinal degeneration, specifically drugs intended to target removal of lipids from Bruch's membrane and/or alleviate ocular inflammation.
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Affiliation(s)
- Mayur Choudhary
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Faryan Tayyari
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Goldis Malek
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
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Profiling Microglia in a Mouse Model of Machado–Joseph Disease. Biomedicines 2022; 10:biomedicines10020237. [PMID: 35203447 PMCID: PMC8869404 DOI: 10.3390/biomedicines10020237] [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: 12/31/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/01/2023] Open
Abstract
Microglia have been increasingly implicated in neurodegenerative diseases (NDs), and specific disease associated microglia (DAM) profiles have been defined for several of these NDs. Yet, the microglial profile in Machado–Joseph disease (MJD) remains unexplored. Here, we characterized the profile of microglia in the CMVMJD135 mouse model of MJD. This characterization was performed using primary microglial cultures and microglial cells obtained from disease-relevant brain regions of neonatal and adult CMVMJD135 mice, respectively. Machine learning models were implemented to identify potential clusters of microglia based on their morphological features, and an RNA-sequencing analysis was performed to identify molecular perturbations and potential therapeutic targets. Our findings reveal morphological alterations that point to an increased activation state of microglia in CMVMJD135 mice and a disease-specific transcriptional profile of MJD microglia, encompassing a total of 101 differentially expressed genes, with enrichment in molecular pathways related to oxidative stress, immune response, cell proliferation, cell death, and lipid metabolism. Overall, these results allowed us to define the cellular and molecular profile of MJD-associated microglia and to identify genes and pathways that might represent potential therapeutic targets for this disorder.
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Kurmann L, Okoniewski M, Dubey RK. Transcryptomic Analysis of Human Brain -Microvascular Endothelial Cell Driven Changes in -Vascular Pericytes. Cells 2021; 10:cells10071784. [PMID: 34359953 PMCID: PMC8304094 DOI: 10.3390/cells10071784] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 12/12/2022] Open
Abstract
Many pathological conditions of the brain are associated with structural abnormalities within the neurovascular system and linked to pericyte (PC) loss and/or dysfunction. Since crosstalk between endothelial cells (ECs) and PCs greatly impacts the function of the blood–brain barrier (BBB), effects of PCs on endothelial integrity and function have been investigated extensively. However, the impact of ECs on the function and activity of PCs remains largely unknown. Hence, using co-cultures of human brain vascular PCs with human cerebral microvascular ECs on opposite sides of porous Transwell inserts which facilitates direct EC–PC contact and improves EC barrier function, we analyzed EC-driven transcriptomic changes in PCs using microarrays and changes in cytokines/chemokines using proteome arrays. Gene expression analysis (GEA) in PCs co-cultured with ECs versus PCs cultured alone showed significant upregulation of 1′334 genes and downregulation of 964 genes. GEA in co-cultured PCs revealed increased expression of five prominent PC markers as well as soluble factors, such as transforming growth factor beta, fibroblast growth factor, angiopoietin 1, brain-derived neurotrophic factor, all of which are involved in EC–PC crosstalk and BBB induction. Pathway enrichment analysis of modulated genes showed a strong impact on many inflammatory and extracellular matrix (ECM) pathways including interferon and interleukin signaling, TGF-β and interleukin-1 regulation of ECM, as well as on the mRNA processing pathway. Interestingly, while co-culture induced the mRNA expression of many chemokines and cytokines, including several CCL- and CXC-motif ligands and interleukins, we observed a decreased expression of the same inflammatory mediators on the protein level. Importantly, in PCs, ECs significantly induced interferon associated proteins (IFIT1, IFI44L, IF127, IFIT3, IFI6, IFI44) with anti-viral actions; downregulated prostaglandin E receptor 2 (prevent COX-2 mediated BBB damage); upregulated fibulin-3 and connective tissue growth factor essential for BBB integrity; and multiple ECMs (collagens and integrins) that inhibit cell migration. Our findings suggest that via direct contact, ECs prime PCs to induce molecules to promote BBB integrity and cell survival during infection and inflammatory insult. Taken together, we provide first evidence that interaction with ECs though porous membranes induces major changes in the transcriptomic and proteomic profile of PCs. ECs influence genes involved in diverse aspects of PC function including PC maturation, cell survival, anti-viral defense, blood flow regulation, immuno-modulation and ECM deposition.
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Affiliation(s)
- Lisa Kurmann
- Department of Reproductive Endocrinology, University Hospital Zurich, 8952 Schlieren, Switzerland;
| | | | - Raghvendra K. Dubey
- Department of Reproductive Endocrinology, University Hospital Zurich, 8952 Schlieren, Switzerland;
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15219, USA
- Correspondence:
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Chen JWE, Lumibao J, Leary S, Sarkaria JN, Steelman AJ, Gaskins HR, Harley BAC. Crosstalk between microglia and patient-derived glioblastoma cells inhibit invasion in a three-dimensional gelatin hydrogel model. J Neuroinflammation 2020; 17:346. [PMID: 33208156 PMCID: PMC7677841 DOI: 10.1186/s12974-020-02026-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Glioblastoma is the most common and deadly form of primary brain cancer, accounting for more than 13,000 new diagnoses annually in the USA alone. Microglia are the innate immune cells within the central nervous system, acting as a front-line defense against injuries and inflammation via a process that involves transformation from a quiescent to an activated phenotype. Crosstalk between GBM cells and microglia represents an important axis to consider in the development of tissue engineering platforms to examine pathophysiological processes underlying GBM progression and therapy. METHODS This work used a brain-mimetic hydrogel system to study patient-derived glioblastoma specimens and their interactions with microglia. Here, glioblastoma cells were either cultured alone in 3D hydrogels or in co-culture with microglia in a manner that allowed secretome-based signaling but prevented direct GBM-microglia contact. Patterns of GBM cell invasion were quantified using a three-dimensional spheroid assay. Secretome and transcriptome (via RNAseq) were used to profile the consequences of GBM-microglia interactions. RESULTS Microglia displayed an activated phenotype as a result of GBM crosstalk. Three-dimensional migration patterns of patient-derived glioblastoma cells showed invasion was significantly decreased in response to microglia paracrine signaling. Potential molecular mechanisms underlying with this phenotype were identified from bioinformatic analysis of secretome and RNAseq data. CONCLUSION The data demonstrate a tissue engineered hydrogel platform can be used to investigate crosstalk between immune cells of the tumor microenvironment related to GBM progression. Such multi-dimensional models may provide valuable insight to inform therapeutic innovations to improve GBM treatment.
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Affiliation(s)
- Jee-Wei Emily Chen
- Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jan Lumibao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Current Address: Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Sarah Leary
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jann N Sarkaria
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Andrew J Steelman
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, 110 Roger Adams Laboratory, 600 S. Mathews Ave, Urbana, IL, 61801, USA
| | - H Rex Gaskins
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, 110 Roger Adams Laboratory, 600 S. Mathews Ave, Urbana, IL, 61801, USA
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, 110 Roger Adams Laboratory, 600 S. Mathews Ave, Urbana, IL, 61801, USA
| | - Brendan A C Harley
- Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, 110 Roger Adams Laboratory, 600 S. Mathews Ave, Urbana, IL, 61801, USA.
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Rao P, Suvas PK, Jerome AD, Steinle JJ, Suvas S. Role of Insulin-Like Growth Factor Binding Protein-3 in the Pathogenesis of Herpes Stromal Keratitis. Invest Ophthalmol Vis Sci 2020; 61:46. [PMID: 32106295 PMCID: PMC7329945 DOI: 10.1167/iovs.61.2.46] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose The goal of this study was to determine the role of insulin-like growth factor-binding protein-3 (IGFBP-3) in the pathogenesis of herpes stromal keratitis (HSK). Methods In an unbiased approach, a membrane-based protein array was carried out to determine the level of expression of pro- and anti-angiogenic molecules in uninfected and HSV-1 infected corneas. Quantitative RT-PCR and ELISA assays were performed to measure the amounts of IGFBP-3 at mRNA and protein levels. Confocal microscopy documented the localization of IGFBP-3 in uninfected and infected corneal tissue. Flow cytometry assay showed the frequency of immune cell types in infected corneas from C57BL/6J (B6) and IGFBP-3 knockout (IGFBP-3-/-) mice. Slit-lamp microscopy was used to quantitate the development of opacity and neovascularization in infected corneas from both groups of mice. Results Quantitation of protein array dot blot showed an increased level of IGFBP-3 protein in HSV-1 infected than uninfected corneas and was confirmed with ELISA and quantitative RT-PCR assays. Cytosolic and nuclear localization of IGFBP-3 were detected in the cells of corneal epithelium, whereas scattered IGFBP-3 staining was evident in the stroma of HSK developing corneas. Increased opacity and hemangiogenesis were noted in the corneas of IGFBP-3-/- than B6 mice during the clinical period of HSK. Furthermore, an increased number of leukocytes comprising of neutrophils and CD4 T cells were found in HSK developing corneas of IGFBP-3-/- than B6 mice. Conclusions Our data showed that lack of IGFBP-3 exacerbates HSK, suggesting the protective effect of IGFBP-3 protein in regulating the severity of HSK.
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Characterization of Mesenchymal Stem Cells Derived from Patients with Cerebellar Ataxia: Downregulation of the Anti-Inflammatory Secretome Profile. Cells 2020; 9:cells9010212. [PMID: 31952198 PMCID: PMC7016790 DOI: 10.3390/cells9010212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023] Open
Abstract
Mesenchymal stem cell (MSC) therapy is a promising alternative approach for the treatment of neurodegenerative diseases, according to its neuroprotective and immunomodulatory potential. Despite numerous clinical trials involving autologous MSCs, their outcomes have often been unsuccessful. Several reports have indicated that MSCs from patients have low capacities in terms of the secretion of neurotrophic or anti-inflammatory factors, which might be associated with cell senescence or disease severity. Therefore, a new strategy to improve their capacities is required for optimal efficacy of autologous MSC therapy. In this study, we compared the secretory potential of MSCs among cerebellar ataxia patients (CA-MSCs) and healthy individuals (H-MSCs). Our results, including secretome analysis findings, revealed that CA-MSCs have lower capacities in terms of proliferation, oxidative stress response, motility, and immunomodulatory functions when compared with H-MSCs. The functional differences were validated in a scratch wound healing assay and neuron-glia co-cultures. In addition, the neuroprotective and immunoregulatory protein follistatin-like 1 (FSTL1) was identified as one of the downregulated proteins in the CA-MSC secretome, with suppressive effects on proinflammatory microglial activation. Our study findings suggest that targeting aspects of the downregulated anti-inflammatory secretome, such as FSTL1, might improve the efficacy of autologous MSC therapy for CA.
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Liu L, Jiang Y, Steinle JJ. Glycyrrhizin protects IGFBP-3 knockout mice from retinal damage. Cytokine 2019; 125:154856. [PMID: 31526985 DOI: 10.1016/j.cyto.2019.154856] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 11/28/2022]
Abstract
We previously reported that insulin-like growth factor binding protein 3 (IGFBP-3) knockout (KO) mice have neuronal and vascular damage to the retina. We also reported that glycyrrhizin, a high mobility growth factor binding protein 1 (HMGB1) inhibitor, is protective to the diabetic retina. In this study, we investigated whether glycyrrhizin could reduce neuronal and vascular damage in the IGFBP-3 KO mouse retina. We used measurements of retinal thickness, cell number in the ganglion cell layer, degenerate capillaries, reactive oxygen species (ROS) and protein levels of HMGB1, tumor necrosis factor alpha (TNFα), interleukin-1-beta (IL-1β) and sirtuin 1 (SIRT1) to determine whether glycyrrhizin could protect the retina. Data show that glycyrrhizin in the drinking water was effective in reducing neuronal damage at 2 months and vascular damage at 6 months. Glycyrrhizin reduced ROS levels at 6 months, and reduced levels of HMGB1, TNFα, and IL-1β at both 2 and 6 months. Taken together, the data suggest that glycyrrhizin is protective to the retina of IGFBP-3 KO mice through anti-inflammatory mechanisms.
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Affiliation(s)
- Li Liu
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Youde Jiang
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Jena J Steinle
- Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Tsang JKW, Liu J, Lo ACY. Vascular and Neuronal Protection in the Developing Retina: Potential Therapeutic Targets for Retinopathy of Prematurity. Int J Mol Sci 2019; 20:E4321. [PMID: 31484463 PMCID: PMC6747312 DOI: 10.3390/ijms20174321] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/21/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022] Open
Abstract
Retinopathy of prematurity (ROP) is a common retinal disease in preterm babies. To prolong the lives of preterm babies, high oxygen is provided to mimic the oxygen level in the intrauterine environment for postnatal organ development. However, hyperoxia-hypoxia induced pathological events occur when babies return to room air, leading to ROP with neuronal degeneration and vascular abnormality that affects retinal functions. With advances in neonatal intensive care, it is no longer uncommon for increased survival of very-low-birth-weight preterm infants, which, therefore, increased the incidence of ROP. ROP is now a major cause of preventable childhood blindness worldwide. Current proven treatment for ROP is limited to invasive retinal ablation, inherently destructive to the retina. The lack of pharmacological treatment for ROP creates a great need for effective and safe therapies in these developing infants. Therefore, it is essential to identify potential therapeutic agents that may have positive ROP outcomes, especially in preserving retinal functions. This review gives an overview of various agents in their efficacy in reducing retinal damages in cell culture tests, animal experiments and clinical studies. New perspectives along the neuroprotective pathways in the developing retina are also reviewed.
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Affiliation(s)
- Jessica K W Tsang
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Jin Liu
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Amy C Y Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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Liu L, Jiang Y, Steinle JJ. Epac1 and Glycyrrhizin Both Inhibit HMGB1 Levels to Reduce Diabetes-Induced Neuronal and Vascular Damage in the Mouse Retina. J Clin Med 2019; 8:jcm8060772. [PMID: 31159195 PMCID: PMC6616522 DOI: 10.3390/jcm8060772] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/23/2019] [Accepted: 05/27/2019] [Indexed: 12/25/2022] Open
Abstract
The role of high mobility group box 1 (HMGB1) in acute diabetic retinal damage has been demonstrated. We recently reported that glycyrrhizin, a HMGB1 inhibitor, protected the diabetic retina against neuronal, vascular, and permeability changes. In this study, we wanted to investigate the role of exchange protein for cAMP 1 (Epac1) on HMGB1 and the actions of glycyrrhizin. Using endothelial cell specific knockout mice for Epac1, we made some mice diabetic using streptozotocin, and treated some with glycyrrhizin for up to 6 months. We measured permeability, neuronal, and vascular changes in the Epac1 floxed and knockout mice. We also investigated whether Epac1 and glycyrrhizin work synergistically to reduce the retinal inflammatory mediators, tumor necrosis factor alpha (TNFα) and interleukin-1-beta (IL1β), as well as sirtuin 1 (SIRT1) levels. Epac1 and glycyrrhizin reduced inflammatory mediators with synergistic actions. Glycyrrhizin also increased SIRT1 levels in the Epac1 mice. Overall, these studies demonstrate that glycyrrhizin and Epac1 can work together to protect the retina. Finally, glycyrrhizin may regulate HMGB1 through increased SIRT1 actions.
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Affiliation(s)
- Li Liu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Youde Jiang
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Jena J Steinle
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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Trost A, Bruckner D, Rivera FJ, Reitsamer HA. Pericytes in the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1122:1-26. [DOI: 10.1007/978-3-030-11093-2_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Jiang Y, Liu L, Steinle JJ. Epac1 deacetylates HMGB1 through increased IGFBP-3 and SIRT1 levels in the retinal vasculature. Mol Vis 2018; 24:727-732. [PMID: 30581279 PMCID: PMC6279194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/14/2018] [Indexed: 10/31/2022] Open
Abstract
Purpose Inflammation is a key component of retinal disease. We previously reported that exchange protein for cAMP 1 (Epac1) reduced inflammatory mediators, including total levels of high mobility group box 1 (HMGB1) in retinal endothelial cells (RECs) and the mouse retina. The goal of this study was to determine intermediate pathways that allow Epac1 to reduce HMGB1, which could lead to novel targets for therapeutics. Methods We used endothelial cell-specific conditional knockout mice for Epac1 and RECs to investigate whether Epac1 requires activation of insulin like growth factor binding protein 3 (IGFBP-3) and sirtuin 1 (SIRT1) to reduce acetylated HMGB1 levels with immunoprecipitation, western blot, and enzyme-linked immunosorbent assay (ELISA). Results Data showed that high glucose reduced IGFBP-3 and SIRT1 levels, and increased acetylation of HMGB1 in RECs. An Epac1 agonist reduced acetylated HMGB1 levels in high glucose. The Epac1 agonist could not reduce HMGB1 or SIRT1 levels when IGFBP-3 siRNA was used. The agonist also could not reduce HMGB1 when SIRT1 siRNA was used. The mouse retina showed that loss of Epac1 increases acetylated HMGB1 levels and reduces IGFBP-3 and SIRT1 levels. Conclusions Taken together, the data suggest that Epac1 activates IGFBP-3 to increase SIRT1, leading to a significant reduction in acetylated HMGB1. These findings provide novel therapeutic targets for reducing key inflammatory cascades in the retina.
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Zhang HB, Wang XD, Xu K, Li XG. The progress of prophylactic treatment in retinopathy of prematurity. Int J Ophthalmol 2018; 11:858-873. [PMID: 29862189 DOI: 10.18240/ijo.2018.05.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 09/28/2017] [Indexed: 12/19/2022] Open
Abstract
Retinopathy of prematurity (ROP) is a retinal vascular disorder frequently found in premature infants. Different therapeutic strategies have been developed to treat ROP. However, there are still many children with ROP suffering by severe limitations in vision or even blindness. Recently, ROP has been suggested to be caused by abnormal development of the retinal vasculature, but not simply resulted by retinal neovascularization which takes about 4 to 6wk after birth in premature infants. Thus, instead of focusing on how to reduce retinal neovascularization, understanding the pathological changes and mechanisms that occur prior to retinal neovascularization is meaningful, which may lead to identify novel target(s) for the development of novel strategy to promote the healthy growth of retinal blood vessels rather than passively waiting for the appearance of retinal neovascularization and removing it by force. In this review, we discussed recent studies about, 1) the pathogenesis prior to retinal neovascularization in oxygen-induced retinopathy (OIR; a ROP in animal model) and in premature infants with ROP; 2) the preclinical and clinical research on preventive treatment of early OIR and ROP. We will not only highlight the importance of the mechanisms and signalling pathways in regulating early stage of ROP but also will provide guidance for actively exploring novel mechanisms and discovering novel treatments for early phase OIR and ROP prior to retinal neovascularization in the future.
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Affiliation(s)
- Hong-Bing Zhang
- Eye Institute of Shaanxi Province; Xi'an First Hospital, Xi'an 710002, Shaanxi Province, China
| | - Xiao-Dong Wang
- Eye Institute of Shaanxi Province; Xi'an First Hospital, Xi'an 710002, Shaanxi Province, China
| | - Kun Xu
- Eye Institute of Shaanxi Province; Xi'an First Hospital, Xi'an 710002, Shaanxi Province, China
| | - Xiao-Gang Li
- Department of Internal Medicine; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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15
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Smyth LCD, Rustenhoven J, Park TIH, Schweder P, Jansson D, Heppner PA, O'Carroll SJ, Mee EW, Faull RLM, Curtis M, Dragunow M. Unique and shared inflammatory profiles of human brain endothelia and pericytes. J Neuroinflammation 2018; 15:138. [PMID: 29751771 PMCID: PMC5948925 DOI: 10.1186/s12974-018-1167-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/18/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Pericytes and endothelial cells are critical cellular components of the blood-brain barrier (BBB) and play an important role in neuroinflammation. To date, the majority of inflammation-related studies in endothelia and pericytes have been carried out using immortalised cell lines or non-human-derived cells. Whether these are representative of primary human cells is unclear and systematic comparisons of the inflammatory responses of primary human brain-derived pericytes and endothelia has yet to be performed. METHODS To study the effects of neuroinflammation at the BBB, primary brain endothelial cells and pericytes were isolated from human biopsy tissue. Culture purity was examined using qPCR and immunocytochemistry. Electrical cell-substrate impedance sensing (ECIS) was used to determine the barrier properties of endothelial and pericyte cultures. Using immunocytochemistry, cytometric bead array, and ECIS, we compared the responses of endothelia and pericytes to a panel of inflammatory stimuli (IL-1β, TNFα, LPS, IFN-γ, TGF-β1, IL-6, and IL-4). Secretome analysis was performed to identify unique secretions of endothelia and pericytes in response to IL-1β. RESULTS Endothelial cells were pure, moderately proliferative, retained the expression of BBB-related junctional proteins and transporters, and generated robust TEER. Both endothelia and pericytes have the same pattern of transcription factor activation in response to inflammatory stimuli but respond differently at the secretion level. Secretome analysis confirmed that endothelia and pericytes have overlapping but distinct secretome profiles in response to IL-1β. We identified several cell-type specific responses, including G-CSF and GM-CSF (endothelial-specific), and IGFBP2 and IGFBP3 (pericyte-specific). Finally, we demonstrated that direct addition of IL-1β, TNFα, LPS, and IL-4 contributed to the loss of endothelial barrier integrity in vitro. CONCLUSIONS Here, we identify important cell-type differences in the inflammatory response of brain pericytes and endothelia and provide, for the first time, a comprehensive profile of the secretions of primary human brain endothelia and pericytes which has implications for understanding how inflammation affects the cerebrovasculature.
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Affiliation(s)
- Leon C D Smyth
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Justin Rustenhoven
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Thomas I-H Park
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Patrick Schweder
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Deidre Jansson
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Peter A Heppner
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Simon J O'Carroll
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Edward W Mee
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Auckland City Hospital, Auckland, 1023, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Maurice Curtis
- Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.,Department of Anatomy and Medical Imaging, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Mike Dragunow
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand. .,Centre for Brain Research, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
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16
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Choi SH, Chung M, Park SW, Jeon NL, Kim JH, Yu YS. Relationship between Pericytes and Endothelial Cells in Retinal Neovascularization: A Histological and Immunofluorescent Study of Retinal Angiogenesis. KOREAN JOURNAL OF OPHTHALMOLOGY 2018; 32:70-76. [PMID: 29376221 PMCID: PMC5801093 DOI: 10.3341/kjo.2016.0115] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 07/03/2017] [Indexed: 12/26/2022] Open
Abstract
Purpose To evaluate the relationship between pericytes and endothelial cells in retinal neovascularization through histological and immunofluorescent studies. Methods C57BL/6J mice were exposed to hyperoxia from postnatal day (P) 7 to P12 and were returned to room air at P12 to induce a model of oxygen-induced retinopathy (OIR). The cross sections of enucleated eyes were processed with hematoxylin and eosin. Immunofluorescent staining of pericytes, endothelial cells, and N-cadherin was performed. Microfluidic devices were fabricated out of polydimethylsiloxane using soft lithography and replica molding. Human retinal microvascular endothelial cells, human brain microvascular endothelial cells, human umbilical vein endothelial cells and human placenta pericyte were mixed and co-cultured. Results Unlike the three-layered vascular plexus found in retinal angiogenesis of a normal mouse, angiogenesis in the OIR model is identified by the neovascular tuft extending into the vitreous. Neovascular tufts and the three-layered vascular plexus were both covered with pericytes in the OIR model. In this pathologic vascularization, N-cadherin, known to be crucial intercellular adhesion molecule, was also present. Further evaluation using the microfluidic in vitro model, successfully developed a microvascular network of endothelial cells covered with pericytes, mimicking normal retinal angiogenesis within 6 days. Conclusions Pericytes covering endothelial cells were observed not only in vasculature of normal retina but also pathologic neovascularization of OIR mouse at P17. Factors involved in the endothelial cell-pericyte interaction can be evaluated as an attractive novel treatment target. These future studies can be performed using microfluidic systems, which can shorten the study time and provide three-dimensional structural evaluation.
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Affiliation(s)
- Se Hyun Choi
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Minhwan Chung
- Mechanical Engineering, Seoul National University, Seoul, Korea
| | - Sung Wook Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea.,FARB (Fight against Angiogenesis-Related Blindness) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Noo Li Jeon
- Mechanical Engineering, Seoul National University, Seoul, Korea
| | - Jeong Hun Kim
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea.,FARB (Fight against Angiogenesis-Related Blindness) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Young Suk Yu
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.,FARB (Fight against Angiogenesis-Related Blindness) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
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17
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Patel C, Xu Z, Shosha E, Xing J, Lucas R, Caldwell RW, Caldwell RB, Narayanan SP. Treatment with polyamine oxidase inhibitor reduces microglial activation and limits vascular injury in ischemic retinopathy. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1862:1628-39. [PMID: 27239699 PMCID: PMC5091072 DOI: 10.1016/j.bbadis.2016.05.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/26/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022]
Abstract
Retinal vascular injury is a major cause of vision impairment in ischemic retinopathies. Insults such as hyperoxia, oxidative stress and inflammation contribute to this pathology. Previously, we showed that hyperoxia-induced retinal neurodegeneration is associated with increased polyamine oxidation. Here, we are studying the involvement of polyamine oxidases in hyperoxia-induced injury and death of retinal vascular endothelial cells. New-born C57BL6/J mice were exposed to hyperoxia (70% O2) from postnatal day (P) 7 to 12 and were treated with the polyamine oxidase inhibitor MDL 72527 or vehicle starting at P6. Mice were sacrificed after different durations of hyperoxia and their retinas were analyzed to determine the effects on vascular injury, microglial cell activation, and inflammatory cytokine profiling. The results of this analysis showed that MDL 72527 treatment significantly reduced hyperoxia-induced retinal vascular injury and enhanced vascular sprouting as compared with the vehicle controls. These protective effects were correlated with significant decreases in microglial activation as well as levels of inflammatory cytokines and chemokines. In order to model the effects of polyamine oxidation in causing microglial activation in vitro, studies were performed using rat brain microvascular endothelial cells treated with conditioned-medium from rat retinal microglia stimulated with hydrogen peroxide. Conditioned-medium from activated microglial cultures induced cell stress signals and cell death in microvascular endothelial cells. These studies demonstrate the involvement of polyamine oxidases in hyperoxia-induced retinal vascular injury and retinal inflammation in ischemic retinopathy, through mechanisms involving cross-talk between endothelial cells and resident retinal microglia.
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Affiliation(s)
- C Patel
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Occupational Therapy, College of Allied Health Sciences, Augusta University, Augusta, GA 30912, USA.
| | - Z Xu
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA.
| | - E Shosha
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Charlie Norwood VA Medical Center, Augusta, GA, USA.
| | - J Xing
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA.
| | - R Lucas
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Pharmacology & Toxicology, Augusta University, Augusta, GA 30912, USA.
| | - R W Caldwell
- Department of Pharmacology & Toxicology, Augusta University, Augusta, GA 30912, USA.
| | - R B Caldwell
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA 30912, USA; Charlie Norwood VA Medical Center, Augusta, GA, USA.
| | - S P Narayanan
- Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA; Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Occupational Therapy, College of Allied Health Sciences, Augusta University, Augusta, GA 30912, USA.
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18
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Liu L, Jiang Y, Steinle JJ. Compound 49b Restores Retinal Thickness and Reduces Degenerate Capillaries in the Rat Retina following Ischemia/Reperfusion. PLoS One 2016; 11:e0159532. [PMID: 27439004 PMCID: PMC4954700 DOI: 10.1371/journal.pone.0159532] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/05/2016] [Indexed: 11/19/2022] Open
Abstract
We have recently reported that Compound 49b, a novel β-adrenergic receptor agonist, can significantly reduce VEGF levels in retinal endothelial cells (REC) grown in diabetic-like conditions. In this study, we investigated whether Compound 49b could protect the retina under hypoxic conditions using the ischemia-reperfusion (I/R)-induced model in rats, as well REC cultured in hypoxic conditions. Some rats received 1mM topical Compound 49b for the 2 (5 rats each group) or 10 (4 rats in each group) days post-I/R. Analyses for retinal thickness and cell loss in the ganglion cell layer was done at 2 days post-I/R, while numbers of degenerate capillaries and pericyte ghosts were measured at 10 days post-I/R. Additionally, REC were cultured in normal oxygen or hypoxia (5% O2) only or treated with 50 nM Compound 49b for 12 hours. Twelve hours after Compound 49b exposure, cells were collected and analyzed for protein levels of insulin-like growth factor binding protein 3 (IGFBP-3), vascular endothelial cell growth factor (VEGF) and its receptor (KDR), angiopoietin 1 and its receptor Tie2 for Western blotting. Data indicate that exposure to I/R significantly decreased retinal thickness, with increasing numbers of degenerate capillaries and pericyte ghosts. Compound 49b treatment inhibited these retinal changes. In REC cultured in hypoxia, levels of IGFBP-3 were reduced, which were significantly increased by Compound 49b. Hypoxia significantly increased protein levels of VEGF, KDR, Angiopoiein 1, and Tie2, which were reduced following Compound 49b treatment. These data strongly suggested that Compound 49b protected the retina against I/R-induced injury. This provides additional support for a role of β-adrenergic receptor actions in the retina.
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Affiliation(s)
- Li Liu
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, 48201, United States of America
| | - Youde Jiang
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, 48201, United States of America
| | - Jena J. Steinle
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, 48201, United States of America
- Department of Ophthalmology, Wayne State University, Detroit, MI, 48201, United States of America
- * E-mail:
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19
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Trinh TLP, Li Calzi S, Shaw LC, Yoder MC, Grant MB. Promoting vascular repair in the retina: can stem/progenitor cells help? Eye Brain 2016; 8:113-122. [PMID: 28539806 PMCID: PMC5398749 DOI: 10.2147/eb.s94451] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Since its first epidemic in the 1940s, retinopathy of prematurity (ROP) has been a challenging illness in neonatology. Higher than physiological oxygen levels impede the development of the immature retinal neuropil and vasculature. Current treatment regimens include cryotherapy, laser photocoagulation, and anti-VEGF agents. Unfortunately, none of these approaches can rescue the normal retinal vasculature, and each has significant safety concerns. The limitations of these approaches have led to new efforts to understand the pathological characteristics in each phase of ROP and to find a safer and more effective therapeutic approach. In the era of stem cell biology and with the need for new treatments for ROP, this review discusses the possible future use of unique populations of proangiogenic cells for therapeutic revascularization of the preterm retina.
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Affiliation(s)
| | | | | | - Mervin C Yoder
- Department of Pediatrics.,Herman B. Wells Center for Pediatric Research.,Department of Biochemistry and Molecular Biology, Indiana University - Purdue University Indianapolis, Indianapolis, IN, USA
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20
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Zhang Q, Jiang Y, Steinle JJ. IGFBP-3 reduces eNOS and PKCzeta phosphorylation, leading to lowered VEGF levels. Mol Vis 2015; 21:604-11. [PMID: 26015772 PMCID: PMC4443585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/20/2015] [Indexed: 10/25/2022] Open
Abstract
PURPOSE In models of diabetic retinopathy, insulin-like growth factor binding protein-3 (IGFBP-3) is protective to the retina, especially retinal microvascular endothelial cells (RECs), but the underlying mechanisms are unclear. For this study, we hypothesized that IGFBP-3 may reduce vascular endothelial growth factor (VEGF) levels through reduced endothelial nitric oxide synthase (eNOS) activity, which may be protective against macular edema. METHODS To test this hypothesis, we grew primary human retinal endothelial cells in normal glucose (5 mM) or high glucose (25 mM) for three days, treated with IGFBP-3 NB plasmid (a plasmid of IGFBP-3 that cannot bind IGF-1), followed by western blotting for eNOS, protein kinase C zeta (PKCzeta), and VEGF. Additionally, we treated some cells with recombinant eNOS or PKCzeta, after IGFBP-3 NB plasmid transfection to validate that these pathways regulate VEGF levels. Immunoprecipitation experiments were done with the eNOS antibody, followed by western blotting for PKCzeta, to determine if eNOS and PKCzeta interact directly. RESULTS Our results suggest that 1) IGFBP-3 inhibits the endothelial nitric oxide synthase (eNOS) and protein kinase C zeta (PKCzeta) pathway, which in turn inhibits VEGF production, and 2) that eNOS plays a role in activating PKCzeta to increase VEGF levels in diabetic retinopathy. CONCLUSIONS In conclusion, IGFBP-3 may be a novel treatment for macular edema through the inhibition of eNOS and PKCzeta activation, leading to reduced VEGF levels.
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Affiliation(s)
- Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
| | - Youde Jiang
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Jena J. Steinle
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN,Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI,Department of Ophthalmology, Wayne State University, Detroit, MI
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21
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Hu P, Thinschmidt JS, Caballero S, Adamson S, Cole L, Chan-Ling T, Grant MB. Loss of survival factors and activation of inflammatory cascades in brain sympathetic centers in type 1 diabetic mice. Am J Physiol Endocrinol Metab 2015; 308:E688-98. [PMID: 25714673 PMCID: PMC4398829 DOI: 10.1152/ajpendo.00504.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/13/2015] [Indexed: 02/02/2023]
Abstract
Neuroinflammation and neurodegeneration have been observed in the brain in type 1 diabetes (T1D). However, little is known about the mediators of these effects. In T1D mice with 12- and 35-wk duration of diabetes we examined two mechanisms of neurodegeneration, loss of the neuroprotective factors insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) and changes in indoleamine 2,3-dioxygenase (IDO) expression in the brain, and compared the response to age-matched controls. Furthermore, levels of matrix metalloproteinase-2 (MMP-2), nucleoside triphosphate diphosphohydrolase-1 (CD39), and ionized calcium-binding adaptor molecule 1 (Iba-1) were utilized to assess inflammatory changes in astrocytes, microglia, and blood vessels. In the diabetic hypothalamus (HYPO), we observed 20% reduction in neuronal soma diameter (P<0.05) and reduced neuronal expression of IGFBP-3 (-32%, P<0.05) and IGF-I (-15%, P<0.05) compared with controls at 35 wk. In diabetic HYPO, MMP-2 expression was increased in astrocytes (46%, P<0.01), and IDO⁺ cell density rose by (62%, P<0.05). CD39 expression dropped by 30% (P<0.05) in microglia and blood vessels. With 10 wk of systemic treatment using minocycline, an anti-inflammatory agent that crosses the blood-brain barrier, MMP-2, IDO, and CD39 levels normalized (P<0.05). Our results suggest that increased IDO and early loss of CD39⁺ protective cells lead to activation of inflammation in sympathetic centers of the CNS. As a downstream effect, the loss of the neuronal survival factors IGFBP-3 and IGF-I and the neurotoxic products of the kynurenine pathway contribute to the loss of neuronal density observed in the HYPO in T1D.
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Affiliation(s)
- Ping Hu
- Department of Anatomy, School of Medical Sciences, Bosch Institute, The University of Sydney, Camperdown, New South Wales, Australia
| | - Jeffrey S Thinschmidt
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Sergio Caballero
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Samuel Adamson
- Department of Anatomy, School of Medical Sciences, Bosch Institute, The University of Sydney, Camperdown, New South Wales, Australia
| | - Louise Cole
- Advanced Microscopy Facility, Bosch Institute, School of Medical Sciences, The University of Sydney, Camperdown, New South Wales, Australia; and
| | - Tailoi Chan-Ling
- Department of Anatomy, School of Medical Sciences, Bosch Institute, The University of Sydney, Camperdown, New South Wales, Australia
| | - Maria B Grant
- Department of Ophthalmology, The Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana
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22
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23
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Thakran S, Zhang Q, Morales-Tirado V, Steinle JJ. Pioglitazone restores IGFBP-3 levels through DNA PK in retinal endothelial cells cultured in hyperglycemic conditions. Invest Ophthalmol Vis Sci 2014; 56:177-84. [PMID: 25525174 DOI: 10.1167/iovs.14-15550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Previously, we reported that pioglitazone prevented insulin resistance and cell death in type 2 diabetic retina by reducing TNFα and suppressor of cytokine signaling 3 (SOCS3) levels. Numerous reports suggest prominent vasoprotective effects of insulin growth factor binding protein-3 (IGFBP-3) in diabetic retinopathy. We hypothesized that pioglitazone protects against retinal cell apoptosis by regulating IGFBP-3 levels, in addition to reducing TNFα. The current study explored potential IGFBP-3 regulatory pathways by pioglitazone in retinal endothelial cells cultured in high glucose. METHODS Primary human retinal endothelial cells (REC) were grown in normal (5 mM) and high glucose (25 mM) and treated with pioglitazone for 24 hours. Cell lysates were processed for Western blotting and ELISA analysis to evaluate IGFBP-3, TNFα, and cleaved caspase 3 protein levels. RESULTS Our results show that treatment with pioglitazone restored the high glucose-induced decrease in IGFBP-3 levels. This regulation was independent of TNFα actions, as reducing TNFα levels with siRNA did not prevent pioglitazone from increasing IGFBP-3 levels. Pioglitazone required protein kinase A (PKA) and DNA-dependent protein kinase (DNA PK) activity to regulate IGFBP-3, as specific inhibitors for each protein prevented pioglitazone-mediated normalization of IGFBP-3 in high glucose. Insulin growth factor binding protein-3 activity was increased and apoptosis decreased by pioglitazone, which was eliminated when serine site 156 of IGFBP-3 was mutated suggesting a key role of this phosphorylation site in pioglitazone actions. CONCLUSIONS Our findings suggest that pioglitazone mediates regulation of IGFBP-3 via activation of PKA/DNA PK pathway in hyperglycemic retinal endothelial cells.
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Affiliation(s)
- Shalini Thakran
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Vanessa Morales-Tirado
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Jena J Steinle
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
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24
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Ortiz G, Salica JP, Chuluyan EH, Gallo JE. Diabetic retinopathy: could the alpha-1 antitrypsin be a therapeutic option? Biol Res 2014; 47:58. [PMID: 25723058 PMCID: PMC4335423 DOI: 10.1186/0717-6287-47-58] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/13/2014] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy is one of the most important causes of blindness. The underlying mechanisms of this disease include inflammatory changes and remodeling processes of the extracellular-matrix (ECM) leading to pericyte and vascular endothelial cell damage that affects the retinal circulation. In turn, this causes hypoxia leading to release of vascular endothelial growth factor (VEGF) to induce the angiogenesis process. Alpha-1 antitrypsin (AAT) is the most important circulating inhibitor of serine proteases (SERPIN). Its targets include elastase, plasmin, thrombin, trypsin, chymotrypsin, proteinase 3 (PR-3) and plasminogen activator (PAI). AAT modulates the effect of protease-activated receptors (PARs) during inflammatory responses. Plasma levels of AAT can increase 4-fold during acute inflammation then is so-called acute phase protein (APPs). Individuals with low serum levels of AAT could develop disease in lung, liver and pancreas. AAT is involved in extracellular matrix remodeling and inflammation, particularly migration and chemotaxis of neutrophils. It can also suppress nitric oxide (NO) by nitric oxide sintase (NOS) inhibition. AAT binds their targets in an irreversible way resulting in product degradation. The aim of this review is to focus on the points of contact between multiple factors involved in diabetic retinopathy and AAT resembling pleiotropic effects that might be beneficial.
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Affiliation(s)
- Gustavo Ortiz
- Nanomedicine and Vision Group, Facultad de Ciencias Biomédicas, Universidad Austral, Buenos Aires Pilar, Argentina. .,Ciudad Autónoma de Buenos Aires, CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina.
| | - Juan P Salica
- Nanomedicine and Vision Group, Facultad de Ciencias Biomédicas, Universidad Austral, Buenos Aires Pilar, Argentina.
| | - Eduardo H Chuluyan
- Departamento de Farmacología,Ciudad Autónoma de Buenos Aires, Universidad de Buenos Aires, Buenos Aires, Argentina. .,Ciudad Autónoma de Buenos Aires, CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina.
| | - Juan E Gallo
- Nanomedicine and Vision Group, Facultad de Ciencias Biomédicas, Universidad Austral, Buenos Aires Pilar, Argentina. .,Ciudad Autónoma de Buenos Aires, CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina.
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Zhang Q, Steinle JJ. IGFBP-3 inhibits TNF-α production and TNFR-2 signaling to protect against retinal endothelial cell apoptosis. Microvasc Res 2014; 95:76-81. [PMID: 25086184 DOI: 10.1016/j.mvr.2014.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/16/2014] [Accepted: 07/22/2014] [Indexed: 01/09/2023]
Abstract
In models of diabetic retinopathy, insulin-like growth factor binding protein-3 (IGFBP-3) protects against tumor necrosis factors-alpha (TNF-α)-mediated apoptosis of retinal microvascular endothelial cells (REC), but the underlying mechanisms are unclear. Our current findings suggest that at least two discrete but complimentary pathways contribute to the protective effects of IGFBP-3; 1) IGFBP-3 directly activates the c-Jun kinase/tissue inhibitor of metalloproteinase-3/TNF-α converting enzyme (c-Jun/TIMP-3/TACE), pathway, which in turn inhibits TNF-α production; 2) IGFBP-3 acts through the IGFBP-3 receptor, low-density lipoprotein receptor-related protein 1 (LRP1), to inhibit signaling of TNF-α receptor 2 (TNFR2). Combined, these two IGFBP-3 pathways substantially reduce REC apoptosis and offer potential targets for the treatment of diabetic retinopathy.
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Affiliation(s)
- Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jena J Steinle
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA.
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Increase of zinc finger protein 179 in response to CCAAT/enhancer binding protein delta conferring an antiapoptotic effect in astrocytes of Alzheimer's disease. Mol Neurobiol 2014; 51:370-82. [PMID: 24788683 PMCID: PMC4309906 DOI: 10.1007/s12035-014-8714-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 04/10/2014] [Indexed: 01/27/2023]
Abstract
Reactive astrogliosis is a cellular manifestation of neuroinflammation and occurs in response to all forms and severities of the central nervous system (CNS)'s injury and disease. Both astroglial proliferation and antiapoptotic processes are aspects of astrogliosis. However, the underlying mechanism of this response remains poorly understood. In addition, little is known about why activated astrocytes are more resistant to stress and inflammation. CCAAT/enhancer binding protein delta (CEBPD) is a transcription factor found in activated astrocytes that surround β-amyloid plaques. In this study, we found that astrocytes activation was attenuated in the cortex and hippocampus of APPswe/PS1 E9 (AppTg)/Cebpd (-/-)mice. Furthermore, an increase in apoptotic astrocytes was observed in AppTg/Cebpd (-/-)mice, suggesting that CEBPD plays a functional role in enhancing the antiapoptotic ability of astrocytes. We found that Zinc Finger Protein 179 (ZNF179) was a CEBPD-regulated gene that played an antiapoptotic, but not proliferative, role in astrocytes. The transcriptions of the proapoptotic genes, insulin-like growth factor binding protein 3 (IGFBP3) and BCL2-interacting killer (BIK), were suppressed by ZNF179 via its interaction with the promyelocytic leukemia zinc finger (PLZF) protein in astrocytes. This study provides the first evidence that ZNF179, PLZF, IGFBP3, and BIK contributed to the novel CEBPD-induced antiapoptotic feature of astrocytes.
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Gene expression of IGF1, IGF1R, and IGFBP3 in epiretinal membranes of patients with proliferative diabetic retinopathy: preliminary study. Mediators Inflamm 2013; 2013:986217. [PMID: 24379526 PMCID: PMC3863537 DOI: 10.1155/2013/986217] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/04/2013] [Indexed: 11/17/2022] Open
Abstract
The molecular mechanism formation of secondary epiretinal membranes (ERMs) after proliferative diabetic retinopathy (PDR) or primary idiopathic ERMs is still poorly understood. Therefore, the present study focused on the assessment of IGF1, IGF1R, and IGFBP3 mRNA levels in ERMs and PBMCs from patients with PDR. The examined group comprised 6 patients with secondary ERMs after PDR and the control group consisted of 11 patients with idiopathic ERMs. Quantification of IGF1, IGF1R, and IGFBP3 mRNAs was performed by real-time QRT-PCR technique. In ERMs, IGF1 and IGF1R mRNA levels were significantly higher in patients with diabetes compared to control subjects. In PBMCs, there were no statistically significant differences of IGF1, IGF1R, and IGFBP3 expression between diabetic and nondiabetic patients. In conclusion, our study indicated IGF1 and IGF1R differential expression in ERMs, but not in PBMCs, of diabetic and nondiabetic patients, suggesting that these factors can be involved in the pathogenesis or progression of proliferative vitreoretinal disorders. This trial is registered with NCT00841334.
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Regulation of retinal endothelial cell apoptosis through activation of the IGFBP-3 receptor. Apoptosis 2013; 18:361-8. [PMID: 23291901 DOI: 10.1007/s10495-012-0793-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The goal of this study was to investigate whether insulin-like growth factor binding protein-3 receptor (IGFBP-3 receptor) is required for IGFBP-3 to inhibit retinal endothelial cell (REC) apoptosis. REC were grown in normal glucose (5 mM) or high glucose medium (25 mM) for 3 days. Once cells reached confluence, they were transfected with an endothelial- specific IGFBP-3 plasmid DNA (non-IGF binding; IGFBP-3 NB) at 1 μg/ml for 24 h. Cell proteins were extracted and analyzed for IGFBP-3 receptor expression by Western blotting or use in coimmunoprecipitation or co-localization experiments for detection of IGFBP-3 and IGFBP-3 receptor binding. REC were also transfected with or without IGFBP-3 receptor siRNA before IGFBP-3NB plasmid DNA transfection. Cell lysates were processed for a cell death ELISA, a cleaved caspase 3 ELISA, and Western blotting to measure key pro- and anti-apoptotic markers: Bcl-xL, Bax, Cytochrome C and Akt. The IGFBP-3 receptor is present on REC. Overexpression of IGFBP-3 in REC significantly increased protein levels of IGFBP-3 receptor (p < 0.05). Significant increases in cell death were found in cells transfected with IGFBP-3 receptor siRNA versus not treated samples (p < 0.05). Data suggest that IGFBP-3 inhibits retinal endothelial cell death through activation of an IGFBP-3 receptor in a hyperglycemic environment. This is the first demonstration of the involvement of IGFBP-3 receptor in inhibition of REC cell death. Future studies will investigate the mechanism by which IGFBP-3 receptor may inhibit retinal endothelial cell death.
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Zhang Q, Jiang Y, Miller MJ, Peng B, Liu L, Soderland C, Tang J, Kern TS, Pintar J, Steinle JJ. IGFBP-3 and TNF-α regulate retinal endothelial cell apoptosis. Invest Ophthalmol Vis Sci 2013; 54:5376-84. [PMID: 23868984 DOI: 10.1167/iovs.13-12497] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We hypothesized that loss of insulin-like growth factor binding protein 3 (IGFBP-3) signaling would produce neuronal changes in the retina similar to early diabetes. METHODS To understand better the role of IGFBP-3 in the retina, IGFBP-3 knockout (KO) mice were evaluated for neuronal, vascular, and functional changes compared to wild-type littermates. We also cultured retinal endothelial cells (REC) in normoglycemia or hyperglycemia to determine the interaction between IGFBP-3 and TNF-α, as data indicate that both proteins are regulated by β-adrenergic receptors and respond antagonistically. We also treated some cells with Compound 49b, a novel β-adrenergic receptor agonist we have reported previously to regulate IGFBP-3 and TNF-α. RESULTS Electroretinogram analyses showed decreased B-wave and oscillatory potential amplitudes in the IGFBP-3 KO mice, corresponding to increased apoptosis. Retinal thickness and cell numbers in the ganglion cell layer were reduced in the IGFBP-3 KO mice. As expected, loss of IGFBP-3 was associated with increased TNF-α levels. When TNF-α and IGFBP-3 were applied to REC, they worked antagonistically, with IGFBP-3 inhibiting apoptosis and TNF-α promoting apoptosis. Due to their antagonistic nature, results suggest that apoptosis of REC may depend upon which protein (IGFBP-3 versus TNF-α) is active. CONCLUSIONS Taken together, loss of IGFBP-3 signaling results in a phenotype similar to neuronal changes observed in diabetic retinopathy in the early phases, including increased TNF-α levels.
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Affiliation(s)
- Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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30
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Lau JC, Kroes RA, Moskal JR, Linsenmeier RA. Diabetes changes expression of genes related to glutamate neurotransmission and transport in the Long-Evans rat retina. Mol Vis 2013; 19:1538-53. [PMID: 23878504 PMCID: PMC3716414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 07/16/2013] [Indexed: 12/02/2022] Open
Abstract
PURPOSE This study investigated changes in the transcript levels of genes related to glutamate neurotransmission and transport as diabetes progresses in the Long-Evans rat retina. Transcript levels of vascular endothelial growth factor (VEGF), erythropoietin, and insulin-like growth factor binding protein 3 (IGFBP3) were also measured due to their protective effects on the retinal vasculature and neurons. METHODS Diabetes was induced in Long-Evans rats with a single intraperitoneal (IP) injection of streptozotocin (STZ; 65 mg/kg) in sodium citrate buffer. Rats with blood glucose >300 mg/dl were deemed diabetic. Age-matched controls received a single IP injection of sodium citrate buffer only. The retinas were dissected at 4 and 12 weeks after induction of diabetes, and mRNA and protein were extracted from the left and right retinas of each rat, respectively. Gene expression was analyzed using quantitative real-time reverse-transcription PCR. Enzyme-linked immunosorbent assay was used to quantify the concentration of VEGF protein in each retina. Statistical significance was determined using 2×2 analysis of variance followed by post-hoc analysis using Fisher's protected least squares difference. RESULTS Transcript levels of two ionotropic glutamate receptor subunits and one glutamate transporter increased after 4 weeks of diabetes. In contrast, 12 weeks of diabetes decreased the transcript levels of several genes, including two glutamate transporters, four out of five N-methyl-D-aspartate (NMDA) receptor subunits, and all five kainate receptor subunits. Diabetes had a greater effect on gene expression of NMDA and kainate receptor subunits than on the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits, for which only GRIA4 significantly decreased after 12 weeks. VEGF protein levels were significantly increased in 4-week diabetic rats compared to age-matched control rats whereas the increase was not significant after 12 weeks. Transcript levels of VEGF and VEGF receptors were unchanged with diabetes. Erythropoietin and IGFBP3 mRNA levels significantly increased at both time points, and IGFBP2 mRNA levels increased after 12 weeks. CONCLUSIONS Diabetes caused significant changes in the transcriptional expression of genes related to ionotropic glutamate neurotransmission, especially after 12 weeks. Most genes with decreased transcript levels after 12 weeks were expressed by retinal ganglion cells, which include glutamate transporters and ionotropic glutamate receptors. Two genes expressed by retinal ganglion cells but unrelated to glutamate neurotransmission, γ-synuclein (SNCG) and adenosine A1 receptor (ADORA1), also had decreased mRNA expression after 12 weeks. These findings may indicate ganglion cells were lost as diabetes progressed in the retina. Decreased expression of the glutamate transporter SLC1A3 would lead to decreased removal of glutamate from the extracellular space, suggesting that diabetes impairs this function of Müller cells. These findings suggest that ganglion cells were lost due to glutamate excitotoxicity. The changes at 12 weeks occurred without significant changes in retinal VEGF protein or mRNA, although higher VEGF protein levels at 4 weeks may be an early protective response. Increased transcript levels of erythropoietin and IGFBP3 may also be a protective response.
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Affiliation(s)
- Jennifer C.M. Lau
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL,Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - Roger A. Kroes
- Falk Center for Molecular Therapeutics, Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - Joseph R. Moskal
- Falk Center for Molecular Therapeutics, Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - Robert A. Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston, IL,Department of Neurobiology, Northwestern University, Evanston, IL,Department of Ophthalmology, Northwestern University, Chicago, IL
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Nguyen DV, Calzi SL, Shaw LC, Kielczewski JL, Korah HE, Grant MB. An ocular view of the IGF-IGFBP system. Growth Horm IGF Res 2013; 23:45-52. [PMID: 23578754 PMCID: PMC3833084 DOI: 10.1016/j.ghir.2013.03.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 02/28/2013] [Accepted: 03/13/2013] [Indexed: 01/16/2023]
Abstract
IGFs and their binding proteins have been shown to exhibit both protective and deleterious effects in ocular disease. Recent studies have characterized the expression patterns of different IGFBPs in retinal layers and within the vitreous. IGFBP-3 has roles in vascular protection stimulating proliferation, migration, and differentiation of vascular progenitor cells to sites of injury. IGFBP-3 increases pericyte ensheathment and shows anti-inflammatory effects by reducing microglia activation in diabetes. IGFBP-5 has recently been linked to mediating fibrosis in proliferative vitreoretinopathy but also reduces neovascularization. Thus, the regulatory balance between IGF and IGFBPs can have profound impact on target tissues. This review discusses recent findings of IGF and IGFBP expression in the eye with relevance to different retinopathies.
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Hård AL, Smith LE, Hellström A. Nutrition, insulin-like growth factor-1 and retinopathy of prematurity. Semin Fetal Neonatal Med 2013; 18:136-142. [PMID: 23428885 PMCID: PMC3809333 DOI: 10.1016/j.siny.2013.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Retinopathy of prematurity is a potentially blinding disease starting with impaired retinal vessel growth in the neonatal period. Weeks to months later, peripheral retinal hypoxia induces pathologic neovascularization that may lead to retinal detachment and blindness. Current treatment strategies target late stage disease and it would be advantageous if retinopathy of prematurity could be prevented. Poor general growth after very preterm birth is a universal problem associated with increased risk of retinopathy. Loss of the maternal-fetal interaction results not only in loss of nutrients but also of other factors provided in utero. The importance of nutrition and factors such as insulin-like growth factor-1 and ω-3 long chain fatty acids for proper retinal vascularization has been defined in animal studies. Increasing evidence of the applicability of these findings to human infants is accumulating. This review focuses on factors essential for neonatal growth and possible strategies to improve growth and prevent retinopathy.
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Affiliation(s)
- Anna-Lena Hård
- Section of Pediatric Ophthalmology, The Queen Silvia Children’s Hospital, The Sahlgrenska Academy at University of Gothenburg, S-416 85 Göteborg, Sweden
| | - Lois E. Smith
- Department of Ophthalmology, Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Ann Hellström
- Section of Pediatric Ophthalmology, The Queen Silvia Children's Hospital, The Sahlgrenska Academy at University of Gothenburg, S-416 85 Göteborg, Sweden.
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Pericytes derived from adipose-derived stem cells protect against retinal vasculopathy. PLoS One 2013; 8:e65691. [PMID: 23741506 PMCID: PMC3669216 DOI: 10.1371/journal.pone.0065691] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 04/26/2013] [Indexed: 12/21/2022] Open
Abstract
Background Retinal vasculopathies, including diabetic retinopathy (DR), threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With pericyte death or loss, endothelial dysfunction ensues, resulting in hypoxic insult, pathologic angiogenesis, and ultimately blindness. Adipose-derived stem cells (ASCs) differentiate into pericytes, suggesting they may be useful as a protective and regenerative cellular therapy for retinal vascular disease. In this study, we examine the ability of ASCs to differentiate into pericytes that can stabilize retinal vessels in multiple pre-clinical models of retinal vasculopathy. Methodology/Principal Findings We found that ASCs express pericyte-specific markers in vitro. When injected intravitreally into the murine eye subjected to oxygen-induced retinopathy (OIR), ASCs were capable of migrating to and integrating with the retinal vasculature. Integrated ASCs maintained marker expression and pericyte-like morphology in vivo for at least 2 months. ASCs injected after OIR vessel destabilization and ablation enhanced vessel regrowth (16% reduction in avascular area). ASCs injected intravitreally before OIR vessel destabilization prevented retinal capillary dropout (53% reduction). Treatment of ASCs with transforming growth factor beta (TGF-β1) enhanced hASC pericyte function, in a manner similar to native retinal pericytes, with increased marker expression of smooth muscle actin, cellular contractility, endothelial stabilization, and microvascular protection in OIR. Finally, injected ASCs prevented capillary loss in the diabetic retinopathic Akimba mouse (79% reduction 2 months after injection). Conclusions/Significance ASC-derived pericytes can integrate with retinal vasculature, adopting both pericyte morphology and marker expression, and provide functional vascular protection in multiple murine models of retinal vasculopathy. The pericyte phenotype demonstrated by ASCs is enhanced with TGF-β1 treatment, as seen with native retinal pericytes. ASCs may represent an innovative cellular therapy for protection against and repair of DR and other retinal vascular diseases.
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34
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Treadmill exercise ameliorates apoptotic cell death in the retinas of diabetic rats. Mol Med Rep 2013; 7:1745-50. [DOI: 10.3892/mmr.2013.1439] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 04/15/2013] [Indexed: 11/05/2022] Open
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35
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Zhang Q, Jiang Y, Toutounchian JJ, Soderland C, Yates CR, Steinle JJ. Insulin-like growth factor binding protein-3 inhibits monocyte adhesion to retinal endothelial cells in high glucose conditions. Mol Vis 2013; 19:796-803. [PMID: 23592916 PMCID: PMC3626378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 04/03/2013] [Indexed: 12/03/2022] Open
Abstract
PURPOSE Insulin-like growth factor binding protein-3 (IGFBP-3) is cytoprotective in the retina. The goal of this study was to investigate whether IGFBP-3 inhibits monocyte-endothelial cell adhesion associated with hyperglycemia. METHODS Human retinal vascular endothelial cells (RECs) were grown in normal (5 mM), medium (15 mM), or high glucose medium (25 mM) for 72 h. After 48 h, cells were transfected with endothelial-cell-specific, non-IGF binding IGFBP-3 plasmid DNA (IGFBP-3NB) at 1 μg/ml for 24 h. Cells were serum starved for 16 h and treated with tumor necrosis factor-alpha (TNF-α; 10 ng/ml) for 4 h. Cell proteins were extracted and analyzed for intercellular adhesion molecule-1 (ICAM-1) expression with enzyme-linked immunosorbent assay. Additional RECs were plated onto attachment factor-coated slides, grown to 90% confluence in high glucose medium, and transfected with IGFBP-3 NB plasmid DNA or ICAM-1 small interfering RNA before treatment with or without TNF-α (10 ng/ml) for 4 h. Slides were then mounted in a parallel-plate flow chamber and subjected to a continuous flow of U937 human monocytes (10(5)/ml) in culture medium at shear stresses of 2 dynes/cm(2), with continual exposure to TNF-α. RESULTS In high ambient glucose, overexpression of IGFBP-3 in RECs significantly decreased ICAM-1 expression when compared to the TNF-α-treated samples, whereas TNF-α increased monocyte-endothelial cell adhesion. IGFBP-3 significantly decreased monocyte adhesion to RECs in the high glucose condition. RECs transfected with ICAM-1 siRNA also had a decreased number of monocytes attached compared with the scrambled siRNA control. CONCLUSIONS Data suggest that IGFBP-3 reduces monocyte-endothelial cell adhesion through decreased ICAM-1 levels in a hyperglycemic environment. This is the first demonstration of the role of IGFBP-3 in inhibiting monocyte-endothelial cell adhesion.
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Affiliation(s)
- Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
| | - Youde Jiang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
| | - Jordan J. Toutounchian
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN
| | | | - C. Ryan Yates
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN
| | - Jena J. Steinle
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN,Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN
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Mohanraj L, Kim HS, Li W, Cai Q, Kim KE, Shin HJ, Lee YJ, Lee WJ, Kim JH, Oh Y. IGFBP-3 inhibits cytokine-induced insulin resistance and early manifestations of atherosclerosis. PLoS One 2013; 8:e55084. [PMID: 23383064 PMCID: PMC3557269 DOI: 10.1371/journal.pone.0055084] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/17/2012] [Indexed: 12/26/2022] Open
Abstract
Metabolic syndrome is associated with visceral obesity, insulin resistance and an increased risk of cardiovascular diseases. Visceral fat tissue primarily consists of adipocytes that secrete cytokines leading to a state of systemic inflammation in obese conditions. One of the IGF-independent functions of IGFBP-3 is its role as an anti-inflammatory molecule. Our study in obese adolescents show a decrease in total IGFBP-3 levels and increase in proteolyzed IGFBP-3 in circulation when compared to their normal counterparts and establishes a positive correlation between IGFBP-3 proteolysis and adiposity parameters as well as insulin resistance. In human adipocytes, we show that IGFBP-3 inhibits TNF-α-induced NF-κB activity in an IGF-independent manner, thereby restoring the deregulated insulin signaling and negating TNF-α-induced inhibition of glucose uptake. IGFBP-3 further inhibits TNF-α, CRP and high glucose-induced NF-κB activity in human aortic endothelial cells (HAECs) and subsequently suppresses monocyte adhesion to HAEC through the IGFBP-3 receptor. In conclusion, these findings suggest that reduced levels of IGFBP-3 in circulation and reduced expression of IGFBP-3 in macrophages in obesity may result in suppression of its anti-inflammatory functions and therefore IGFBP-3 may present itself as a therapeutic for obesity-induced insulin resistance and for events occurring in the early stages of atherosclerosis.
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Affiliation(s)
- Lathika Mohanraj
- Department of Pathology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ho-Seong Kim
- Department of Pediatrics, Institute of Endocrinology, Yonsei University College of Medicine, Seoul, Korea
| | - Wei Li
- Biocure Pharma LLC, Richmond, Virginia, United States of America
| | - Qing Cai
- Department of Pathology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ki Eun Kim
- Department of Pediatrics, CHA University College of Medicine, Seoul, Korea
| | - Hye-Jung Shin
- Department of Pediatrics, National Medical Center, Seoul, Korea
| | - Yong-Jae Lee
- Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Woo Jung Lee
- Department of Pediatrics, Institute of Endocrinology, Yonsei University College of Medicine, Seoul, Korea
| | - Jung Hyun Kim
- Department of Pediatrics, Institute of Endocrinology, Yonsei University College of Medicine, Seoul, Korea
| | - Youngman Oh
- Department of Pathology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Biocure Pharma LLC, Richmond, Virginia, United States of America
- * E-mail:
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Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3. PLoS One 2012; 7:e39398. [PMID: 22792172 PMCID: PMC3391198 DOI: 10.1371/journal.pone.0039398] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 05/22/2012] [Indexed: 11/19/2022] Open
Abstract
Previously, we showed that insulin growth factor (IGF)-1 binding protein-3 (IGFBP-3), independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR). The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB) integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1) and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP). IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO) release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab). Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB) stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs). NO release was neither associated with an increase in intracellular calcium nor decreased by Ca2+/calmodulin-dependent protein kinase II (CamKII) blockade; however, dephosphorylation of eNOS-Thr495 was observed. Phosphatidylinositol 3-kinase (PI3K) activity and Akt-Ser473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate vasorelaxation via activation of SRB1. This response is IGF-1- and calcium-independent, but requires PI3K/Akt activation, suggesting that IGFBP-3 has novel protective effects on retinal and systemic vasculature and may be a therapeutic candidate for ocular complications such as diabetic retinopathy.
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Zhang Q, Guy K, Pagadala J, Jiang Y, Walker RJ, Liu L, Soderland C, Kern TS, Ferry R, He H, Yates CR, Miller DD, Steinle JJ. Compound 49b prevents diabetes-induced apoptosis through increased IGFBP-3 levels. Invest Ophthalmol Vis Sci 2012; 53:3004-13. [PMID: 22467575 DOI: 10.1167/iovs.11-8779] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
PURPOSE To determine whether Compound 49b, a novel PKA-activating drug, can prevent diabetic-like changes in the rat retina through increased insulin-like growth factor binding protein-3 (IGFBP-3) levels. METHODS For the cell culture studies, we used both human retinal endothelial cells (REC) and retinal Müller cells in either 5 mM (normal) or 25 mM (high) glucose. Cells were treated with 50 nM Compound 49b alone of following treatment with protein kinase A (PKA) siRNA or IGFBP-3 siRNA. Western blotting and ELISA analyses were done to verify PKA and IGFBP-3 knockdown, as well as to measure apoptotic markers. For animal studies, we used streptozotocin-treated rats after 2 and 8 months of diabetes. Some rats were treated topically with 1 mM Compound 49b. Analyses were done for retinal thickness, cell numbers in the ganglion cell layer, pericyte ghosts, and numbers of degenerate capillaries, as well as electroretinogram and heart morphology. RESULTS Compound 49b requires active PKA and IGFBP-3 to prevent apoptosis of REC. Compound 49b significantly reduced the numbers of degenerate capillaries and pericyte ghosts, while preventing the decreased retinal thickness and loss of cells in the ganglion cell layer. Compound 49b maintained a normal electroretinogram, with no changes in blood pressure, intraocular pressure, or heart morphological changes. CONCLUSIONS Topical Compound 49b is able to prevent diabetic-like changes in the rat retina, without producing systemic changes. Compound 49b is able to prevent REC apoptosis through increasing IGFBP-3 levels, which are reduced in response to hyperglycemia.
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Affiliation(s)
- Qiuhua Zhang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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Xu Z, Gong J, Maiti D, Vong L, Wu L, Schwarz JJ, Duh EJ. MEF2C ablation in endothelial cells reduces retinal vessel loss and suppresses pathologic retinal neovascularization in oxygen-induced retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:2548-60. [PMID: 22521302 DOI: 10.1016/j.ajpath.2012.02.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 01/11/2012] [Accepted: 02/02/2012] [Indexed: 12/13/2022]
Abstract
Ischemic retinopathies, including retinopathy of prematurity and diabetic retinopathy, are major causes of blindness. Both have two phases, vessel loss and consequent hypoxia-driven pathologic retinal neovascularization, yet relatively little is known about the transcription factors regulating these processes. Myocyte enhancer factor 2 (MEF2) C, a member of the MEF2 family of transcription factors that plays an important role in multiple developmental programs, including the cardiovascular system, seems to have a significant functional role in the vasculature. We, therefore, generated endothelial cell (EC)-specific MEF2C-deficient mice and explored the role of MEF2C in retinal vascularization during normal development and in a mouse model of oxygen-induced retinopathy. Ablation of MEF2C did not cause appreciable defects in normal retinal vascular development. However, MEF2C ablation in ECs suppressed vessel loss in oxygen-induced retinopathy and strongly promoted vascular regrowth, consequently reducing retinal avascularity. This finding was associated with suppression of pathologic retinal angiogenesis and blood-retinal barrier dysfunction. MEF2C knockdown in cultured retinal ECs using small-interfering RNAs rescued ECs from death and stimulated tube formation under stress conditions, confirming the endothelial-autonomous and antiangiogenic roles of MEF2C. HO-1 was induced by MEF2C knockdown in vitro and may play a role in the proangiogenic effect of MEF2C knockdown on retinal EC tube formation. Thus, MEF2C may play an antiangiogenic role in retinal ECs under stress conditions, and modulation of MEF2C may prevent pathologic retinal neovascularization.
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Affiliation(s)
- Zhenhua Xu
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Nguyen DV, Shaw LC, Grant MB. Inflammation in the pathogenesis of microvascular complications in diabetes. Front Endocrinol (Lausanne) 2012; 3:170. [PMID: 23267348 PMCID: PMC3527746 DOI: 10.3389/fendo.2012.00170] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/05/2012] [Indexed: 12/15/2022] Open
Abstract
Diabetes and hyperglycemia create a proinflammatory microenvironment that progresses to microvascular complications such as nephropathy, retinopathy, and neuropathy. Diet-induced insulin resistance is a potential initiator of this change in type 2 diabetes which can increase adipokines and generate a chronic low-grade inflammatory state. Advanced glycation end-products and its receptor, glycation end-products AGE receptor axis, reactive oxygen species, and hypoxia can also interact to worsen complications. Numerous efforts have gained way to understanding the mechanisms of these modulators and attenuation of the inflammatory response, however, effective treatments have still not emerged. The complexity of inflammatory signaling may suggest a need for multi-targeted therapy. This review presents recent findings aimed at new treatment strategies.
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Affiliation(s)
| | | | - Maria B. Grant
- *Correspondence: Maria B. Grant, Department of Pharmacology and Therapeutics, University of Florida, College of Medicine, P.O. Box 100267, Gainesville, FL 32610-0267, USA. e-mail:
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Kielczewski JL, Li Calzi S, Shaw LC, Cai J, Qi X, Ruan Q, Wu L, Liu L, Hu P, Chan-Ling T, Mames RN, Firth S, Baxter RC, Turowski P, Busik JV, Boulton ME, Grant MB. Free insulin-like growth factor binding protein-3 (IGFBP-3) reduces retinal vascular permeability in association with a reduction of acid sphingomyelinase (ASMase). Invest Ophthalmol Vis Sci 2011; 52:8278-86. [PMID: 21931131 DOI: 10.1167/iovs.11-8167] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE To examine the effect of free insulin-like growth factor (IGF) binding protein-3 (IGFBP-3), independent of the effect of insulin-like growth factors, in modulating retinal vascular permeability. METHODS We assessed the ability of a form of IGFBP-3 that does not bind IGF-1 (IGFBP-3NB), to regulate the blood retinal barrier (BRB) using two distinct experimental mouse models, laser-induced retinal vessel injury and vascular endothelial growth factor (VEGF)-induced retinal vascular permeability. Additionally, in vitro studies were conducted. In the animal models, BRB permeability was quantified by intravenous injection of fluorescein labeled serum albumin followed by digital confocal image analysis of retinal flat-mounts. Claudin-5 and vascular endothelial-cadherin (VE-cadherin) localization at interendothelial junctions was studied by immunofluorescence. In vitro changes in transendothelial electrical resistance (TEER) and flux of fluorescent dextran in bovine retinal endothelial monolayers (BREC) were measured after IGFBP-3NB treatment. Acid (ASMase) and neutral (NSMase) sphingomyelinase mRNA levels and activity were measured in mouse retinas. RESULTS Four days postinjury, laser-injured mouse retinas injected with IGFBP-3NB plasmid demonstrated reduced vascular permeability compared with retinas of laser-injured mouse retinas injected with control plasmid. IGFBP-3NB administration resulted in a significant decrease in laser injury-associated increases in ASMase and NSMase mRNA and activity when compared with laser alone treated mice. In vivo, intravitreal injection of IGFBP-3NB reduced vascular leakage associated with intravitreal VEGF injection. IGFBP-3NB partially restored VEGF-induced in vivo permeability and dissociation of claudin-5 and VE-cadherin at junctional complexes. When IGFBP-3NB was applied basally to bovine retinal endothelial cells (BREC) in vitro, TEER increased and macromolecular flux decreased. CONCLUSIONS Intravitreal administration of IGFBP-3NB preserves junctional integrity in the presence of VEGF or laser injury by reducing BRB permeability in part by modulating sphingomyelinase levels.
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Affiliation(s)
- Jennifer L Kielczewski
- Departments of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida 32610-0267, USA
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