Introduction: Age-related macular degeneration (AMD) is a prevalent, chronic and progressive retinal degenerative disease characterized by an inflammatory response mediated by activated microglia accumulating in the retina. In this study, we demonstrate the therapeutically effects and the underlying mechanisms of microglial repopulation in the laser-induced choroidal neovascularization (CNV) model of exudative AMD.

Methods: The CSF1R inhibitor PLX3397 was used to establish a treatment paradigm for microglial repopulation in the retina. Neovascular leakage and neovascular area were examined by fundus fluorescein angiography (FFA) and immunostaining of whole-mount RPE-choroid-sclera complexes in CNV mice receiving PLX3397. Altered cellular senescence was measured by beta-galactosidase (SA-β-gal) activity and p16INK4a expression. The effect and mechanisms of repopulated microglia on leukocyte infiltration and the inflammatory response in CNV lesions were analyzed.

Results: We showed that ten days of the CSF1R inhibitor PLX3397 treatment followed by 11 days of drug withdrawal was sufficient to stimulate rapid repopulation of the retina with new microglia. Microglial repopulation attenuated pathological choroid neovascularization and dampened cellular senescence in CNV lesions. Repopulating microglia exhibited lower levels of activation markers, enhanced phagocytic function and produced fewer cytokines involved in the immune response, thereby ameliorating leukocyte infiltration and attenuating the inflammatory response in CNV lesions.

Discussion: The microglial repopulation described herein are therefore a promising strategy for restricting inflammation and choroidal neovascularization, which are important players in the pathophysiology of AMD.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070532PMC
http://dx.doi.org/10.3389/fimmu.2024.1366841DOI Listing

Publication Analysis

Top Keywords

microglial repopulation
20
choroidal neovascularization
12
inflammatory response
12
inflammation choroidal
8
csf1r inhibitor
8
inhibitor plx3397
8
repopulation retina
8
cellular senescence
8
leukocyte infiltration
8
response cnv
8

Similar Publications

Article Synopsis
  • CSF1R inhibitors can deplete and rejuvenate microglia in the brain, potentially improving conditions like Alzheimer's disease (AD).
  • The study used 5xFAD mice to investigate how microglial depletion and repopulation affect amyloid plaque progression and found temporary improvements in plaque burden.
  • Although the improvements weren't lasting, renewing microglia late in disease progression may enhance their responsiveness to noradrenergic signaling, suggesting a possible therapeutic approach for AD.
View Article and Find Full Text PDF

A growing body of evidence highlights the importance of microglia, the resident immune cells of the CNS, and their pro-inflammatory activation in the onset of many neurological diseases. Microglial proliferation, differentiation, and survival are highly dependent on the CSF-1 signaling pathway, which can be pharmacologically modulated by inhibiting its receptor, CSF-1R. Pharmacological inhibition of CSF-1R leads to an almost complete microglial depletion whereas treatment arrest allows for subsequent repopulation.

View Article and Find Full Text PDF

Neuro-immunobiology and treatment assessment in a mouse model of anti-NMDAR encephalitis.

Brain

December 2024

Neuroimmunology Program, Fundació Clínic per la Recerca Biomèdica - Institut d'Investigacions Biomèdiques August Pi i Sunyer (FCRB-IDIBAPS), Barcelona 08036, Spain.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a disorder mediated by autoantibodies against the GluN1 subunit of NMDAR. It occurs with severe neuropsychiatric symptoms that often improve with immunotherapy. Clinical studies and animal models based on patients' antibody transfer or NMDAR immunization suggest that the autoantibodies play a major pathogenic role.

View Article and Find Full Text PDF

Background: Reactive astrogliosis and microgliosis are coordinated responses to CNS insults and are pathological hallmarks of traumatic brain injury (TBI). In these conditions, persistent reactive gliosis can impede tissue repopulation and limit neurogenesis. Thus, modulating this phenomenon has been increasingly recognized as potential therapeutic approach.

View Article and Find Full Text PDF
Article Synopsis
  • - Microglia play a key role in regulating cerebral blood flow (CBF), particularly during activities like whisker stimulation or ATP injection, affecting both baseline levels and increases in blood flow.
  • - Depleting microglia reduces activity-dependent blood flow responses, but the body still responds normally to other stimuli like adenosine, indicating a specific function for microglia in this process.
  • - The regulation of CBF by microglia involves the ATP-sensing receptor P2ry12 and the enzyme CD39, which converts extracellular ATP into adenosine, crucial for neurovascular coupling and maintaining healthy blood flow responses.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!