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Updated: Oct 30, 2025
Real-Time Analysis of Bioenergetics in Primary Human Retinal Pigment Epithelial Cells Using High-Resolution Respirometry
Published on: February 3, 2023
Antimycin A-induced mitochondrial dysfunction regulates inflammasome signaling in human retinal pigment epithelial
Eveliina Korhonen1, Maria Hytti2, Niina Piippo2
1Immuno-Ophthalmology, School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, FI-70211, Kuopio, Finland; Department of Clinical Chemistry, University of Helsinki and Helsinki University Hospital, P.O.Box 720, FI-00029, Helsinki, Finland.
Abstract:
Age-related macular degeneration (AMD) is a severe retinal eye disease where dysfunctional mitochondria and damaged mitochondrial DNA in retinal pigment epithelium (RPE) have been demonstrated to underlie the pathogenesis of this devastating disease. In the present study, we aimed to examine whether damaged mitochondria induce inflammasome activation in human RPE cells. Therefore, ARPE-19 cells were primed with IL-1α and exposed to the mitochondrial electron transport chain complex III inhibitor, antimycin A. We found that antimycin A-induced mitochondrial dysfunction caused caspase-1-dependent inflammasome activation and subsequent production of mature IL-1β and IL-18 in human RPE cells. AIM2 and NLRP3 appeared to be the responsible inflammasome receptors upon antimycin A-induced mitochondrial damage. We aimed at verifying our findings using hESC-RPE cells but antimycin A was absorbed by melanin. Therefore, results were repeated on D407 RPE cell cultures. Antimycin A-induced mitochondrial and NADPH oxidase-dependent ROS production occurred upstream of inflammasome activation, whereas K+ efflux was not required for inflammasome activation in antimycin A-treated human RPE cells. Collectively, our data emphasize that dysfunctional mitochondria regulate the assembly of inflammasome multiprotein complexes in the human RPE cells. The present study associates AIM2 with the pathogenesis of AMD.
Insights
Dysfunctional mitochondria in retinal cells trigger inflammasome activation, a key process in age-related macular degeneration (AMD) pathogenesis. This study links mitochondrial damage to inflammasome receptors AIM2 and NLRP3, offering new insights into AMD.
Area of Science:
- Ophthalmology
- Cell Biology
- Immunology
Background:
- Age-related macular degeneration (AMD) is a leading cause of vision loss.
- Mitochondrial dysfunction and damaged mitochondrial DNA in retinal pigment epithelium (RPE) cells are implicated in AMD pathogenesis.
- The role of mitochondrial damage in inflammasome activation within RPE cells remains to be fully elucidated.
Purpose of the Study:
- To investigate whether damaged mitochondria induce inflammasome activation in human RPE cells.
- To identify the specific inflammasome receptors involved in this process.
- To explore the upstream signaling events leading to inflammasome activation.
Main Methods:
- Human RPE cell lines (ARPE-19 and D407) were treated with antimycin A, a mitochondrial inhibitor.
- Cells were primed with IL-1α to prime the inflammasome.
- Caspase-1 activity, IL-1β and IL-18 maturation, and reactive oxygen species (ROS) production were measured.
Main Results:
- Antimycin A-induced mitochondrial dysfunction activated caspase-1-dependent inflammasomes in RPE cells.
- Mature IL-1β and IL-18 were produced, with AIM2 and NLRP3 identified as key inflammasome receptors.
- Mitochondrial damage and NADPH oxidase-dependent ROS production preceded inflammasome activation; K+ efflux was not required.
Conclusions:
- Dysfunctional mitochondria drive inflammasome assembly and activation in human RPE cells.
- The study implicates AIM2 in the pathogenesis of age-related macular degeneration (AMD).
- These findings highlight a novel mechanism linking mitochondrial health to RPE inflammatory responses relevant to AMD.
