Fractalkine-induced microglial vasoregulation occurs within the retina and is altered early in diabetic retinopathy
| العنوان: | Fractalkine-induced microglial vasoregulation occurs within the retina and is altered early in diabetic retinopathy |
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| المؤلفون: | Elena Ivanova, Connie H Wong, Bang V. Bui, Gene Venables, Samuel A Mills, Michael A Dixon, Flora Hui, Zheng He, Kirstan A. Vessey, Vickie Hy Wong, Josh Tonc, James C Young, Botir T. Sagdullaev, Andrew I Jobling, Ursula Greferath, Erica L. Fletcher, Joanna A. Phipps |
| المصدر: | Proceedings of the National Academy of Sciences of the United States of America |
| بيانات النشر: | Proceedings of the National Academy of Sciences, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | retina, microglia, Tetrazoles, Streptozocin, Renin-Angiotensin System, chemistry.chemical_compound, Mice, 03 medical and health sciences, 0302 clinical medicine, fractalkine, CX3CR1, Medicine, Animals, 030304 developmental biology, Neurons, Retina, 0303 health sciences, Diabetic Retinopathy, Multidisciplinary, Microglia, diabetes, business.industry, Chemokine CX3CL1, Gene Expression Profiling, Biphenyl Compounds, Retinal Vessels, Retinal, Diabetic retinopathy, Cell Biology, Biological Sciences, capillary regulation, medicine.disease, Streptozotocin, Cell biology, Rats, Candesartan, medicine.anatomical_structure, chemistry, Vasoconstriction, Benzimidazoles, medicine.symptom, business, Pericytes, 030217 neurology & neurosurgery, medicine.drug, Signal Transduction |
| الوصف: | Significance This work identifies a role for microglia, the innate immune cells of the CNS, in the local control of the retinal vasculature and identifies deficits early in diabetes. Microglia contact neurons and vasculature and express several vasoactive agents. Activation of microglial fractalkine-Cx3cr1 signaling leads to capillary constriction and blocking the renin-angiotensin system (RAS) with candesartan abolishes microglial-mediated vasoconstriction in the retina. In early diabetes, reduced retinal blood flow is coincident with capillary constriction, increased microglial–vessel association, loss of microglial–capillary regulation, and altered microglial expression of the RAS pathway. While candesartan restores retinal capillary diameter early in diabetes, targeting of microglial–vascular regulation is required to prevent coincident dilation of large retinal vessels and reduced retinal blood flow. Local blood flow control within the central nervous system (CNS) is critical to proper function and is dependent on coordination between neurons, glia, and blood vessels. Macroglia, such as astrocytes and Müller cells, contribute to this neurovascular unit within the brain and retina, respectively. This study explored the role of microglia, the innate immune cell of the CNS, in retinal vasoregulation, and highlights changes during early diabetes. Structurally, microglia were found to contact retinal capillaries and neuronal synapses. In the brain and retinal explants, the addition of fractalkine, the sole ligand for monocyte receptor Cx3cr1, resulted in capillary constriction at regions of microglial contact. This vascular regulation was dependent on microglial Cx3cr1 involvement, since genetic and pharmacological inhibition of Cx3cr1 abolished fractalkine-induced constriction. Analysis of the microglial transcriptome identified several vasoactive genes, including angiotensinogen, a constituent of the renin-angiotensin system (RAS). Subsequent functional analysis showed that RAS blockade via candesartan abolished microglial-induced capillary constriction. Microglial regulation was explored in a rat streptozotocin (STZ) model of diabetic retinopathy. Retinal blood flow was reduced after 4 wk due to reduced capillary diameter and this was coincident with increased microglial association. Functional assessment showed loss of microglial–capillary response in STZ-treated animals and transcriptome analysis showed evidence of RAS pathway dysregulation in microglia. While candesartan treatment reversed capillary constriction in STZ-treated animals, blood flow remained decreased likely due to dilation of larger vessels. This work shows microglia actively participate in the neurovascular unit, with aberrant microglial–vascular function possibly contributing to the early vascular compromise during diabetic retinopathy. |
| تدمد: | 1091-6490 0027-8424 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c184d211cc76f8f4bfa1337044ce4ff2 https://doi.org/10.1073/pnas.2112561118 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....c184d211cc76f8f4bfa1337044ce4ff2 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10916490 00278424 |
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