1. Invasion of Human Retinal Pigment Epithelial Cells by Porphyromonas gingivalis leading to Vacuolar/Cytosolic localization and Autophagy dysfunction In-Vitro.
- Author
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Arjunan P, Swaminathan R, Yuan J, Al-Shabrawey M, Espinosa-Heidmann DG, Nussbaum J, Martin PM, and Cutler CW
- Subjects
- Cell Line, Humans, Autophagosomes metabolism, Autophagosomes microbiology, Autophagosomes ultrastructure, Autophagy, Bacteroidaceae Infections metabolism, Bacteroidaceae Infections microbiology, Bacteroidaceae Infections pathology, Cytosol metabolism, Cytosol microbiology, Cytosol ultrastructure, Porphyromonas gingivalis metabolism, Porphyromonas gingivalis ultrastructure, Retinal Pigment Epithelium metabolism, Retinal Pigment Epithelium microbiology, Retinal Pigment Epithelium ultrastructure, Vacuoles microbiology, Vacuoles pathology, Vacuoles ultrastructure
- Abstract
Recent epidemiological studies link Periodontal disease(PD) to age-related macular degeneration (AMD). We documented earlier that Porphyromonas gingivalis(Pg), keystone oral-pathobiont, causative of PD, efficiently invades human gingival epithelial and blood-dendritic cells. Here, we investigated the ability of dysbiotic Pg-strains to invade human-retinal pigment epithelial cells(ARPE-19), their survival, intracellular localization, and the pathological effects, as dysfunction of RPEs leads to AMD. We show that live, but not heat-killed Pg-strains adhere to and invade ARPEs. This involves early adhesion to ARPE cell membrane, internalization and localization of Pg within single-membrane vacuoles or cytosol, with some nuclear localization apparent. No degradation of Pg or localization inside double-membrane autophagosomes was evident, with dividing Pg suggesting a metabolically active state during invasion. We found significant downregulation of autophagy-related genes particularly, autophagosome complex. Antibiotic protection-based recovery assay further confirmed distinct processes of adhesion, invasion and amplification of Pg within ARPE cells. This is the first study to demonstrate invasion of human-RPEs, begin to characterize intracellular localization and survival of Pg within these cells. Collectively, invasion of RPE by Pg and its prolonged survival by autophagy evasion within these cells suggest a strong rationale for studying the link between oral infection and AMD pathogenesis in individuals with periodontitis.
- Published
- 2020
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