Oral microbiome link to neurodegeneration in glaucoma
Konstantin Astafurov1, Eman Elhawy2, Lizhen Ren1
1Department of Cell Biology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America.
Plos One
|September 3, 2014
Summary
Chronic oral inflammation and bacteria may contribute to glaucoma. Increased oral bacteria were found in glaucoma patients, and animal models showed this exacerbates optic nerve damage via TLR4 signaling.
Area of Science:
- Ophthalmology
- Neuroscience
- Microbiology
Background:
- Glaucoma is a progressive optic nerve disease leading to blindness.
- Chronic subclinical peripheral inflammation is hypothesized to contribute to glaucoma neurodegeneration.
Purpose of the Study:
- To investigate the role of the oral microbiome in glaucoma pathophysiology.
- To explore the underlying mechanisms of chronic inflammation-induced neurodegeneration in glaucoma.
Main Methods:
- Analyzed bacterial counts in mouthwash from glaucoma patients and controls.
- Administered lipopolysaccharide (LPS) in animal glaucoma models to assess neurodegeneration.
- Examined gene expression of toll-like receptor 4 (TLR4) signaling and complement pathways.
- Assessed microglial activation and the effect of TLR4 blockade.
Main Results:
- Glaucoma patients exhibited higher oral bacterial counts than controls.
- LPS administration enhanced axonal degeneration and neuronal loss in glaucoma models.
- Observed microglial activation and upregulation of TLR4 signaling and complement in the optic nerve and retina.
- TLR4 blockade partially reduced the enhanced damage.
Conclusions:
- The oral microbiome appears to contribute to glaucoma pathophysiology.
- Increased oral bacteria may lead to neurodegeneration via microglial activation through TLR4 and complement pathways.
- Commensal bacteria could play a role in glaucoma and other neurodegenerative disorders.
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