Producción CyT

Medicina - Blue LED light irradiation and A2E perturb mitochondrial morphology and function in retinal pigment epithelial cells. New insights into the pathogenesis of Age-Related Macular Degeneration

Congreso

Autoría:

ALAIMO, AGUSTINA ; Bujjamer JM ; Garcia Liñares Guadalupe ; Gorojod RM ; Porte Alcon S ; Baldessari A ; Grecco HE ; Kotler ML

Fecha:

2016

Editorial y Lugar de Edición:

Estudio Sigma SRL

ISSN:

1669-9106

Resumen *

Age-related macular degeneration (AMD) is a neurodegenerative disease of the elderly. AMD pathogenesis is characterized by retinal pigment epithelium (RPE) degeneration that progress with the light exposure-induced injury. RPE cells accumulate lipofuscin which contributes to their susceptibility to photo-oxidation. Blue light reaches deep into the eye causing cumulative retinal damage and increased AMD risk. Here, we studied the effect of blue light and A2E (major component of lipofuscin) on mitochondrial integrity in the RPE. Human ARPE-19 cells were exposed to blue light (LED λ=445nm; 1.7mW/cm2) for 1-30min and incubated for an additional 24h. The following parameters were studied: mitochondrial metabolic activity (MTT assay), generation of ROS (DCFDA probe) and superoxide (O2?-) (MitoSOX probe) (fluorometry and fluorescence microscopy), mitochondrial mass and shape-changes quantification (Tom-20 ICC/ Mito-Morphology ImageJ Macro). Blue light significantly reduced RPE viability (1min: 89±6%, 5min: 81±2%, 15min: 76±2% 30min: 52±5%) while increased intracellular ROS levels (1min: 34±6%, 5min: 37±2%, 15min: 45±13%, 30min: 53±4%). An early increment in O2?- levels occurred after 1min (74%, p<0.01). Light-exposed cells showed a gradual mitochondrial mass reduction (e.g. 30min: 69%, p<0.05) suggesting a decreased biogenesis. Also, mitochondrial elongation and interconnectivity significantly diminished (e.g. 30min: 38%, p<0.001 and 17%, p<0.05, respectively) and correlates with the appearance of small dots and donuts-like organelles instead of a tubular network. On the other hand, cells exposed to A2E (1-100µM) exhibited a dose-dependent decrease of cell viability (e.g. 10μM: 78±1%, p<0.01). Moreover, mitochondrial metabolic activity, O2?- generation and morphology indicated that A2E-laden cells were more susceptible to phototoxicity than A2E-free cells. Our findings provide insights supporting the relevance of design mitochondrial quality-based therapies for AMD. Información suministrada por el agente en SIGEVA

Palabras Clave

Mitochondrial Quality ControlA2EOxidative StressBlue LED light Retinal Pigment Epithelial CellsAge-related macular degeneration Mitochondria