Abstract
Purpose: :
To evaluate the effect of seeding ARPE-19 cells on the hydrodynamic properties of donor human Bruch’s membrane.
Methods: :
Bruch’s-choroid samples (4-6 per donor eye) were isolated as 8mm discs from the peripheral regions of the fundus and mounted in Perspex tissue cassettes with a 4mm central aperture. Individual cassettes were then inserted into modified Ussing-type chambers and the Bruch’s surface exposed to a hydrostatic pressure head of 14-16mmHg. The hydraulic conductivity of each preparation was calculated from the rate of fluid transport. The cassettes were then transferred to a Petri dish with exposed Bruch’s surface facing upwards. A suspension of ARPE-19 cells was then placed on top of Bruch’s membrane and after an incubation period of 24 hours, all but one of the cassettes from a given donor were rinsed and the attached ARPE-19 cells gently brushed away followed by re-evaluation of the hydraulic conductivity of the preparations. A representative cassette from each donor was processed for light microscopy.
Results: :
Histological examination of the preparations from donors aged 21-91 years showed that the 24-hour incubation period was sufficient to allow attachment and proliferation of ARPE cells resulting in a confluent monolayer on top of Bruch’s membrane. Seeding of ARPE-19 cells onto donor Bruch’s was associated with a marked improvement (3.4-fold ± 1.4 S.D; p<0.05) in the hydraulic conductivity of the membrane (n=16; age range: 21-91 years).
Conclusions: :
Proliferating RPE cells have the potential to modulate the transport properties of Bruch’s membrane. After treatment, the normal age-related exponentially declining curves were displaced upwards towards improved transport. The potential for development of this technique to promote endogenous RPE migration into localised laser lesions may allow ‘cleansing’ of aged Bruch’s membrane. This has implications for therapeutic management in age-related macular degeneration (AMD).
Keywords: age-related macular degeneration • retinal pigment epithelium • retinal pigment epithelium