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Wu X, Zhu H, Liu J, Ouyang S, Lyu Z, Jin Y, Chen X, Meng Q. Jagged1-Notch1 Signaling Pathway Induces M1 Microglia to Disrupt the Barrier Function of Retinal Microvascular Endothelial Cells. Curr Eye Res 2024:1-9. [PMID: 38783634 DOI: 10.1080/02713683.2024.2357601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 05/14/2024] [Indexed: 05/25/2024]
Abstract
PURPOSE Microglia-related inflammation is closely linked to the pathogenesis of retinal diseases. The primary objective of this research was to investigate the impact and mechanism of M1 phenotype microglia on the barrier function of retina microvascular endothelial cells. METHODS Quantitative polymerase chain reactions and western blot techniques were utilized to analysis the mRNA and protein expressions of M1 and M2 markers of human microglial clone 3 cell line (HMC3), as well as the levels of Notch ligands and receptors under the intervention of lipopolysaccharide (LPS) or interleukin (IL)-4. ELISA was utilized to detect the pro-inflammatory and anti-inflammatory cytokines from HMC3 cells. The cellular tight junction and apoptosis of human retinal microvascular endothelial cells (HRMECs) were assessed by western blot and fluorescein isothiocyanate-dextran permeability assay. The inhibitors of Notch1 and RNA interference (RNAi) targeting Jagged1 were used to assess their contribution to the barrier function of vascular endothelial cells. RESULTS Inducible nitric oxide synthase (iNOS) and IL-1β were considerably elevated in LPS-treated HMC3, while CD206 and Arg-1 markedly elevated under IL-4 stimulation. The conditioned medium derived from LPS-treated HMC3 cells promoted permeability, diminished the expression of zonula occludens-1 and Occludin, and elevated the expression of Cleaved caspase-3 in HRMECs. RNAi targeting Jagged1 or Notch1 inhibitor could block M1 HMC3 polarization and maintain barrier function of HRMECs. CONCLUSION Our findings suggest that Jagged1-Notch1 signaling pathway induces M1 microglial cells to disrupt the barrier function of HRMECs, which may lead to retinal diseases.
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Affiliation(s)
- Xiyu Wu
- School of Medicine, South China University of Technology, Guangzhou, China
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Haoxian Zhu
- School of Medicine, South China University of Technology, Guangzhou, China
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Junbin Liu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Shuyi Ouyang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Zheng Lyu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Yeanqi Jin
- School of Medicine, South China University of Technology, Guangzhou, China
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Xinyu Chen
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Qianli Meng
- School of Medicine, South China University of Technology, Guangzhou, China
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
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Rorex C, Cardona SM, Church KA, Rodriguez D, Vanegas D, Saldivar R, Faz B, Cardona AE. Astrogliosis in the GFAP-Cre ERT2:Rosa26 iDTR Mouse Model Does Not Exacerbate Retinal Microglia Activation or Müller Cell Gliosis under Hypoxic Conditions. Biomolecules 2024; 14:567. [PMID: 38785974 PMCID: PMC11117533 DOI: 10.3390/biom14050567] [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: 03/29/2024] [Revised: 04/26/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
Diabetic retinopathy (DR) affects over 140 million people globally. The mechanisms that lead to blindness are still enigmatic but there is evidence that sustained inflammation and hypoxia contribute to vascular damage. Despite efforts to understand the role of inflammation and microglia in DR's pathology, the contribution of astrocytes to hypoxic responses is less clear. To investigate the role of astrocytes in hypoxia-induced retinopathy, we utilized a 7-day systemic hypoxia model using the GFAP-CreERT2:Rosa26iDTR transgenic mouse line. This allows for the induction of inflammatory reactive astrogliosis following tamoxifen and diphtheria toxin administration. We hypothesize that DTx-induced astrogliosis is neuroprotective during hypoxia-induced retinopathy. Glial, neuronal, and vascular responses were quantified using immunostaining, with antibodies against GFAP, vimentin, IBA-1, NeuN, fibrinogen, and CD31. Cytokine responses were measured in both the brain and serum. We report that while both DTx and hypoxia induced a phenotype of reduced microglia morphological activation, DTx, but not hypoxia, induced an increase in the Müller glia marker vimentin. We did not observe that the combination of DTx and hypoxic treatments exacerbated the signs of reactive glial cells, nor did we observe a significant change in the expression immunomodulatory mediators IL-1β, IL2, IL-4, IL-5, IL-6, IL-10, IL-18, CCL17, TGF-β1, GM-CSF, TNF-α, and IFN-γ. Overall, our results suggest that, in this hypoxia model, reactive astrogliosis does not alter the inflammatory responses or cause vascular damage in the retina.
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Affiliation(s)
- Colin Rorex
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
| | - Sandra M. Cardona
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
| | - Kaira A. Church
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
| | - Derek Rodriguez
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
- Integrative Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Difernando Vanegas
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
| | - Reina Saldivar
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
| | - Brianna Faz
- Integrative Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Astrid E. Cardona
- Molecular Microbiology and Immunology, College of Sciences, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (C.R.)
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX 78249, USA
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3
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Wang M, Caryotakis SE, Smith GG, Nguyen AV, Pleasure DE, Soulika AM. CSF1R antagonism results in increased supraspinal infiltration in EAE. J Neuroinflammation 2024; 21:103. [PMID: 38643194 PMCID: PMC11031888 DOI: 10.1186/s12974-024-03063-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 03/11/2024] [Indexed: 04/22/2024] Open
Abstract
BACKGROUND Colony stimulating factor 1 receptor (CSF1R) signaling is crucial for the maintenance and function of various myeloid subsets. CSF1R antagonism was previously shown to mitigate clinical severity in experimental autoimmune encephalomyelitis (EAE). The associated mechanisms are still not well delineated. METHODS To assess the effect of CSF1R signaling, we employed the CSF1R antagonist PLX5622 formulated in chow (PLX5622 diet, PD) and its control chow (control diet, CD). We examined the effect of PD in steady state and EAE by analyzing cells isolated from peripheral immune organs and from the CNS via flow cytometry. We determined CNS infiltration sites and assessed the extent of demyelination using immunohistochemistry of cerebella and spinal cords. Transcripts of genes associated with neuroinflammation were also analyzed in these tissues. RESULTS In addition to microglial depletion, PD treatment reduced dendritic cells and macrophages in peripheral immune organs, both during steady state and during EAE. Furthermore, CSF1R antagonism modulated numbers and relative frequencies of T effector cells both in the periphery and in the CNS during the early stages of the disease. Classical neurological symptoms were milder in PD compared to CD mice. Interestingly, a subset of PD mice developed atypical EAE symptoms. Unlike previous studies, we observed that the CNS of PD mice was infiltrated by increased numbers of peripheral immune cells compared to that of CD mice. Immunohistochemical analysis showed that CNS infiltrates in PD mice were mainly localized in the cerebellum while in CD mice infiltrates were primarily localized in the spinal cords during the onset of neurological deficits. Accordingly, during the same timepoint, cerebella of PD but not of CD mice had extensive demyelinating lesions, while spinal cords of CD but not of PD mice were heavily demyelinated. CONCLUSIONS Our findings suggest that CSF1R activity modulates the cellular composition of immune cells both in the periphery and within the CNS, and affects lesion localization during the early EAE stages.
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Affiliation(s)
- Marilyn Wang
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Sofia E Caryotakis
- Shriners Hospitals for Children, Northern California, Sacramento, CA, USA
- University of California, San Francisco, San Francisco, CA, USA
| | - Glendalyn G Smith
- Shriners Hospitals for Children, Northern California, Sacramento, CA, USA
| | - Alan V Nguyen
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Sutro Biosciences, South San Francisco, CA, USA
| | - David E Pleasure
- Shriners Hospitals for Children, Northern California, Sacramento, CA, USA
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Athena M Soulika
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, CA, USA.
- Shriners Hospitals for Children, Northern California, Sacramento, CA, USA.
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4
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Hu A, Schmidt MHH, Heinig N. Microglia in retinal angiogenesis and diabetic retinopathy. Angiogenesis 2024:10.1007/s10456-024-09911-1. [PMID: 38564108 DOI: 10.1007/s10456-024-09911-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/18/2024] [Indexed: 04/04/2024]
Abstract
Diabetic retinopathy has a high probability of causing visual impairment or blindness throughout the disease progression and is characterized by the growth of new blood vessels in the retina at an advanced, proliferative stage. Microglia are a resident immune population in the central nervous system, known to play a crucial role in regulating retinal angiogenesis in both physiological and pathological conditions, including diabetic retinopathy. Physiologically, they are located close to blood vessels and are essential for forming new blood vessels (neovascularization). In diabetic retinopathy, microglia become widely activated, showing a distinct polarization phenotype that leads to their accumulation around neovascular tufts. These activated microglia induce pathogenic angiogenesis through the secretion of various angiogenic factors and by regulating the status of endothelial cells. Interestingly, some subtypes of microglia simultaneously promote the regression of neovascularization tufts and normal angiogenesis in neovascularization lesions. Modulating the state of microglial activation to ameliorate neovascularization thus appears as a promising potential therapeutic approach for managing diabetic retinopathy.
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Affiliation(s)
- Aiyan Hu
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany.
| | - Nora Heinig
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany.
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5
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Diemler CA, MacLean M, Heuer SE, Hewes AA, Marola OJ, Libby RT, Howell GR. Microglia Depletion leads to Increased Susceptibility to Ocular Hypertension-Dependent Glaucoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.05.583529. [PMID: 38496398 PMCID: PMC10942367 DOI: 10.1101/2024.03.05.583529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
In recent years, microglia have been highlighted for playing integral roles in neurodegenerative diseases, like glaucoma. To better understand the role of microglia during chronic ocular hypertension, we depleted microglia from aged (9-12 months old) DBA/2J (D2) mice, which exhibit age-related increases in intraocular pressure, using a dietary CSF1R antagonist, PLX5622. Retinal ganglion cell (RGC) somas were counted, and optic nerve cross-sections stained and assessed for glaucomatous damage. Sustained administration of dietary PLX5622 significantly reduced the numbers of retinal microglia. Dietary PLX5622 did not lead to changes in intraocular pressure in D2 or normotensive DBA/2J-Gpnmb+ (D2-Gpnmb+) control mice. While PLX5622-treated D2-Gpnmb+ did not develop optic nerve damage, PLX5622-treated D2 mice showed a significant increase in moderate-to-severe optic nerve damage compared to D2 mice fed a control diet. In conclusion, global reduction of microglia exacerbated glaucomatous neurodegeneration in D2 mice suggesting microglia play an overall beneficial role in protecting from ocular hypertension associated RGC loss.
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Affiliation(s)
- Cory A. Diemler
- The Jackson Laboratory, Bar Harbor, ME
- Graduate School of Biological Sciences and Engineering, University of Maine, Orono, ME
| | | | - Sarah E. Heuer
- The Jackson Laboratory, Bar Harbor, ME
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA
| | | | | | - Richard T. Libby
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY
| | - Gareth R. Howell
- The Jackson Laboratory, Bar Harbor, ME
- Graduate School of Biological Sciences and Engineering, University of Maine, Orono, ME
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY
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6
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Shahror RA, Morris CA, Mohammed AA, Wild M, Zaman B, Mitchell CD, Phillips PH, Rusch NJ, Shosha E, Fouda AY. Role of myeloid cells in ischemic retinopathies: recent advances and unanswered questions. J Neuroinflammation 2024; 21:65. [PMID: 38454477 PMCID: PMC10918977 DOI: 10.1186/s12974-024-03058-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/28/2024] [Indexed: 03/09/2024] Open
Abstract
Myeloid cells including microglia and macrophages play crucial roles in retinal homeostasis by clearing cellular debris and regulating inflammation. These cells are activated in several blinding ischemic retinal diseases including diabetic retinopathy, where they may exert both beneficial and detrimental effects on neurovascular function and angiogenesis. Myeloid cells impact the progression of retinal pathologies and recent studies suggest that targeting myeloid cells is a promising therapeutic strategy to mitigate diabetic retinopathy and other ischemic retinal diseases. This review summarizes the recent advances in our understanding of the role of microglia and macrophages in retinal diseases and focuses on the effects of myeloid cells on neurovascular injury and angiogenesis in ischemic retinopathies. We highlight gaps in knowledge and advocate for a more detailed understanding of the role of myeloid cells in retinal ischemic injury to fully unlock the potential of targeting myeloid cells as a therapeutic strategy for retinal ischemia.
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Affiliation(s)
- Rami A Shahror
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Carol A Morris
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Aya A Mohammed
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Melissa Wild
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Bushra Zaman
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Christian D Mitchell
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Paul H Phillips
- Department of Ophthalmology, Harvey & Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Nancy J Rusch
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
| | - Esraa Shosha
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA
- Clinical Pharmacy Department, Cairo University, Cairo, Egypt
| | - Abdelrahman Y Fouda
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences (UAMS), 4301 West Markham Street, Slot 611, BIOMED-1, B306, Little Rock, AR, 72205, USA.
- Clinical Pharmacy Department, Cairo University, Cairo, Egypt.
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7
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Rodriguez D, Church KA, Pietramale AN, Cardona SM, Vanegas D, Rorex C, Leary MC, Muzzio IA, Nash KR, Cardona AE. Fractalkine isoforms differentially regulate microglia-mediated inflammation and enhance visual function in the diabetic retina. J Neuroinflammation 2024; 21:42. [PMID: 38311721 PMCID: PMC10840196 DOI: 10.1186/s12974-023-02983-8] [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: 10/24/2023] [Accepted: 12/01/2023] [Indexed: 02/06/2024] Open
Abstract
Diabetic retinopathy (DR) affects about 200 million people worldwide, causing leakage of blood components into retinal tissues, leading to activation of microglia, the resident phagocytes of the retina, promoting neuronal and vascular damage. The microglial receptor, CX3CR1, binds to fractalkine (FKN), an anti-inflammatory chemokine that is expressed on neuronal membranes (mFKN), and undergoes constitutive cleavage to release a soluble domain (sFKN). Deficiencies in CX3CR1 or FKN showed increased microglial activation, inflammation, vascular damage, and neuronal loss in experimental mouse models. To understand the mechanism that regulates microglia function, recombinant adeno-associated viral vectors (rAAV) expressing mFKN or sFKN were delivered to intact retinas prior to diabetes. High-resolution confocal imaging and mRNA-seq were used to analyze microglia morphology and markers of expression, neuronal and vascular health, and inflammatory mediators. We confirmed that prophylactic intra-vitreal administration of rAAV expressing sFKN (rAAV-sFKN), but not mFKN (rAAV-mFKN), in FKNKO retinas provided vasculo- and neuro-protection, reduced microgliosis, mitigated inflammation, improved overall optic nerve health by regulating microglia-mediated inflammation, and prevented fibrin(ogen) leakage at 4 weeks and 10 weeks of diabetes induction. Moreover, administration of sFKN improved visual acuity. Our results elucidated a novel intervention via sFKN gene therapy that provides an alternative pathway to implement translational and therapeutic approaches, preventing diabetes-associated blindness.
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Affiliation(s)
- Derek Rodriguez
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Kaira A Church
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Alicia N Pietramale
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Sandra M Cardona
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Difernando Vanegas
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Colin Rorex
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Micah C Leary
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Isabel A Muzzio
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - Kevin R Nash
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, 33620, USA
| | - Astrid E Cardona
- Department of Molecular Microbiology and Immunology, UTSA Circle, The University of Texas at San Antonio, San Antonio, TX, 78249, USA.
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8
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Rodriguez D, Church KA, Smith CT, Vanegas D, Cardona SM, Muzzio IA, Nash KR, Cardona AE. Therapeutic Delivery of Soluble Fractalkine Ameliorates Vascular Dysfunction in the Diabetic Retina. Int J Mol Sci 2024; 25:1727. [PMID: 38339005 PMCID: PMC10855319 DOI: 10.3390/ijms25031727] [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: 12/14/2023] [Revised: 01/20/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Diabetic retinopathy (DR)-associated vision loss is a devastating disease affecting the working-age population. Retinal pathology is due to leakage of serum components into retinal tissues, activation of resident phagocytes (microglia), and vascular and neuronal damage. While short-term interventions are available, they do not revert visual function or halt disease progression. The impact of microglial inflammatory responses on the neurovascular unit remains unknown. In this study, we characterized microglia-vascular interactions in an experimental model of DR. Early diabetes presents activated retinal microglia, vascular permeability, and vascular abnormalities coupled with vascular tortuosity and diminished astrocyte and endothelial cell-associated tight-junction (TJ) and gap-junction (GJ) proteins. Microglia exclusively bind to the neuronal-derived chemokine fractalkine (FKN) via the CX3CR1 receptor to ameliorate microglial activation. Using neuron-specific recombinant adeno-associated viruses (rAAVs), we therapeutically overexpressed soluble (sFKN) or membrane-bound (mFKN) FKN using intra-vitreal delivery at the onset of diabetes. This study highlights the neuroprotective role of rAAV-sFKN, reducing microglial activation, vascular tortuosity, fibrin(ogen) deposition, and astrogliosis and supporting the maintenance of the GJ connexin-43 (Cx43) and TJ zonula occludens-1 (ZO-1) molecules. The results also show that microglia-vascular interactions influence the vascular width upon administration of rAAV-sFKN and rAAV-mFKN. Administration of rAAV-sFKN improved visual function without affecting peripheral immune responses. These findings suggest that overexpression of rAAV-sFKN can mitigate vascular abnormalities by promoting glia-neural signaling. sFKN gene therapy is a promising translational approach to reverse vision loss driven by vascular dysfunction.
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Affiliation(s)
- Derek Rodriguez
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
| | - Kaira A. Church
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
| | - Chelsea T. Smith
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
| | - Difernando Vanegas
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
| | - Sandra M. Cardona
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
| | - Isabel A. Muzzio
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA;
| | - Kevin R. Nash
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL 33612, USA;
| | - Astrid E. Cardona
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX 78249, USA; (D.R.); (K.A.C.); (C.T.S.); (D.V.); (S.M.C.)
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9
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Laudenberg N, Kinuthia UM, Langmann T. Microglia depletion/repopulation does not affect light-induced retinal degeneration in mice. Front Immunol 2024; 14:1345382. [PMID: 38288111 PMCID: PMC10822957 DOI: 10.3389/fimmu.2023.1345382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 12/28/2023] [Indexed: 01/31/2024] Open
Abstract
Reactive microglia are a hallmark of age-related retinal degenerative diseases including age-related macular degeneration (AMD). These cells are capable of secreting neurotoxic substances that may aggravate inflammation that leads to loss of photoreceptors and impaired vision. Despite their role in driving detrimental inflammation, microglia also play supporting roles in the retina as they are a crucial cellular component of the regulatory innate immune system. In this study, we used the colony stimulating factor 1 receptor (CSF1R)-antagonist PLX3397 to investigate the effects of microglia depletion and repopulation in a mouse model of acute retinal degeneration that mimics some aspects of dry AMD. Our main goal was to investigate whether microglia depletion and repopulation affects the outcome of light-induced retinal degeneration. We found that microglia depletion effectively decreased the expression of several key pro-inflammatory factors but was unable to influence the extent of retinal degeneration as determined by optical coherence tomography (OCT) and histology. Interestingly, we found prominent cell debris accumulation in the outer retina under conditions of microglia depletion, presumably due to the lack of efficient phagocytosis that could not be compensated by the retinal pigment epithelium. Moreover, our in vivo experiments showed that renewal of retinal microglia by repopulation did also not prevent rapid microglia activation or preserve photoreceptor death under conditions of light damage. We conclude that microglia ablation strongly reduces the expression of pro-inflammatory factors but cannot prevent photoreceptor loss in the light-damage paradigm of retinal degeneration.
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Affiliation(s)
- Nils Laudenberg
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Urbanus Muthai Kinuthia
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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10
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Keeley PW, Trod S, Gamboa BN, Coffey PJ, Reese BE. Nfia Is Critical for AII Amacrine Cell Production: Selective Bipolar Cell Dependencies and Diminished ERG. J Neurosci 2023; 43:8367-8384. [PMID: 37775301 PMCID: PMC10711738 DOI: 10.1523/jneurosci.1099-23.2023] [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: 06/13/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 10/01/2023] Open
Abstract
The nuclear factor one (NFI) transcription factor genes Nfia, Nfib, and Nfix are all enriched in late-stage retinal progenitor cells, and their loss has been shown to retain these progenitors at the expense of later-generated retinal cell types. Whether they play any role in the specification of those later-generated fates is unknown, but the expression of one of these, Nfia, in a specific amacrine cell type may intimate such a role. Here, Nfia conditional knockout (Nfia-CKO) mice (both sexes) were assessed, finding a massive and largely selective absence of AII amacrine cells. There was, however, a partial reduction in type 2 cone bipolar cells (CBCs), being richly interconnected to AII cells. Counts of dying cells showed a significant increase in Nfia-CKO retinas at postnatal day (P)7, after AII cell numbers were already reduced but in advance of the loss of type 2 CBCs detected by P10. Those results suggest a role for Nfia in the specification of the AII amacrine cell fate and a dependency of the type 2 CBCs on them. Delaying the conditional loss of Nfia to the first postnatal week did not alter AII cell number nor differentiation, further suggesting that its role in AII cells is solely associated with their production. The physiological consequences of their loss were assessed using the ERG, finding the oscillatory potentials to be profoundly diminished. A slight reduction in the b-wave was also detected, attributed to an altered distribution of the terminals of rod bipolar cells, implicating a role of the AII amacrine cells in constraining their stratification.SIGNIFICANCE STATEMENT The transcription factor NFIA is shown to play a critical role in the specification of a single type of retinal amacrine cell, the AII cell. Using an Nfia-conditional knockout mouse to eliminate this population of retinal neurons, we demonstrate two selective bipolar cell dependencies on the AII cells; the terminals of rod bipolar cells become mis-stratified in the inner plexiform layer, and one type of cone bipolar cell undergoes enhanced cell death. The physiological consequence of this loss of the AII cells was also assessed, finding the cells to be a major contributor to the oscillatory potentials in the electroretinogram.
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Affiliation(s)
- Patrick W Keeley
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060
| | - Stephanie Trod
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060
| | - Bruno N Gamboa
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060
| | - Pete J Coffey
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106-5060
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106-5060
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11
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Hong S, Weerasinghe-Mudiyanselage PDE, Kang S, Moon C, Shin T. Retinal transcriptome profiling identifies novel candidate genes associated with visual impairment in a mouse model of multiple sclerosis. Anim Cells Syst (Seoul) 2023; 27:219-233. [PMID: 37808551 PMCID: PMC10552570 DOI: 10.1080/19768354.2023.2264354] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
Visual impairment is occasionally observed in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Although uveitis and optic neuritis have been reported in MS and EAE, the precise mechanisms underlying the pathogenesis of these visual impairments remain poorly understood. This study aims to identify differentially expressed genes (DEGs) in the retinas of mice with EAE to identify genes that may be implicated in EAE-induced visual impairment. Fourteen adult mice were injected with myelin oligodendrocyte glycoprotein35-55 to induce the EAE model. Transcriptomes of retinas with EAE were analyzed by RNA-sequencing. Gene expression analysis revealed 347 DEGs in the retinas of mice with EAE: 345 were upregulated, and 2 were downregulated (adjusted p-value < 0.05 and absolute log2 fold change > 1). Gene ontology (GO) analysis showed that the upregulated genes in the retinas of mice with EAE were primarily related to immune responses, responses to external biotic stimuli, defense responses, and leukocyte-mediated immunity in the GO biological process. The expression of six upregulated hub genes (c1qb, ctss, itgam, itgb2, syk, and tyrobp) from the STRING analysis and the two significantly downregulated DEGs (hapln1 and ndst4) were validated by reverse transcription-quantitative polymerase chain reaction. In addition, gene set enrichment analysis showed that the negatively enriched gene sets in EAE-affected retinas were associated with the neuronal system and phototransduction cascade. This study provides novel molecular evidence for visual impairments in EAE and indicates directions for further research to elucidate the mechanisms of these visual impairments in MS.
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Affiliation(s)
- Sungmoo Hong
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju, Republic of Korea
| | - Poornima D. E. Weerasinghe-Mudiyanselage
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
| | - Sohi Kang
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju, Republic of Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju, Republic of Korea
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12
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Church KA, Rodriguez D, Mendiola AS, Vanegas D, Gutierrez IL, Tamayo I, Amadu A, Velazquez P, Cardona SM, Gyoneva S, Cotleur AC, Ransohoff RM, Kaur T, Cardona AE. Pharmacological depletion of microglia alleviates neuronal and vascular damage in the diabetic CX3CR1-WT retina but not in CX3CR1-KO or hCX3CR1 I249/M280-expressing retina. Front Immunol 2023; 14:1130735. [PMID: 37033925 PMCID: PMC10077890 DOI: 10.3389/fimmu.2023.1130735] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Diabetic retinopathy, a microvascular disease characterized by irreparable vascular damage, neurodegeneration and neuroinflammation, is a leading complication of diabetes mellitus. There is no cure for DR, and medical interventions marginally slow the progression of disease. Microglia-mediated inflammation in the diabetic retina is regulated via CX3CR1-FKN signaling, where FKN serves as a calming signal for microglial activation in several neuroinflammatory models. Polymorphic variants of CX3CR1, hCX3CR1I249/M280 , found in 25% of the human population, result in a receptor with lower binding affinity for FKN. Furthermore, disrupted CX3CR1-FKN signaling in CX3CR1-KO and FKN-KO mice leads to exacerbated microglial activation, robust neuronal cell loss and substantial vascular damage in the diabetic retina. Thus, studies to characterize the effects of hCX3CR1I249/M280 -expression in microglia-mediated inflammation in the diseased retina are relevant to identify mechanisms by which microglia contribute to disease progression. Our results show that hCX3CR1I249/M280 mice are significantly more susceptible to microgliosis and production of Cxcl10 and TNFα under acute inflammatory conditions. Inflammation is exacerbated under diabetic conditions and coincides with robust neuronal loss in comparison to CX3CR1-WT mice. Therefore, to further investigate the role of hCX3CR1I249/M280 -expression in microglial responses, we pharmacologically depleted microglia using PLX-5622, a CSF-1R antagonist. PLX-5622 treatment led to a robust (~70%) reduction in Iba1+ microglia in all non-diabetic and diabetic mice. CSF-1R antagonism in diabetic CX3CR1-WT prevented TUJ1+ axonal loss, angiogenesis and fibrinogen deposition. In contrast, PLX-5622 microglia depletion in CX3CR1-KO and hCX3CR1I249/M280 mice did not alleviate TUJ1+ axonal loss or angiogenesis. Interestingly, PLX-5622 treatment reduced fibrinogen deposition in CX3CR1-KO mice but not in hCX3CR1I249/M280 mice, suggesting that hCX3CR1I249/M280 expressing microglia influences vascular pathology differently compared to CX3CR1-KO microglia. Currently CX3CR1-KO mice are the most commonly used strain to investigate CX3CR1-FKN signaling effects on microglia-mediated inflammation and the results in this study indicate that hCX3CR1I249/M280 receptor variants may serve as a complementary model to study dysregulated CX3CR1-FKN signaling. In summary, the protective effects of microglia depletion is CX3CR1-dependent as microglia depletion in CX3CR1-KO and hCX3CR1I249/M280 mice did not alleviate retinal degeneration nor microglial morphological activation as observed in CX3CR1-WT mice.
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Affiliation(s)
- Kaira A. Church
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Derek Rodriguez
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Andrew S. Mendiola
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Difernando Vanegas
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Irene L. Gutierrez
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- Department of Pharmacology and Toxicology, Universidad Complutense de Madrid, Centro de Investigacion Biomedica en Red Salud Mental (CIBERSAM), Madrid, Spain
| | - Ian Tamayo
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Abdul Amadu
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Priscila Velazquez
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Sandra M. Cardona
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Stefka Gyoneva
- Human Genetics, Cerevel Therapeutics, Cambridge, MA, United States
- Acute Neurology, Biogen, Cambridge, MA, United States
| | | | - Richard M. Ransohoff
- Acute Neurology, Biogen, Cambridge, MA, United States
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, United States
- Neuroinflammation Research Center, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, United States
| | - Tejbeer Kaur
- Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Astrid E. Cardona
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
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