Abstract
Purpose: :
The spontaneously arising Human Retinal Pigment Epithelium (RPE) cell line ARPE-19 is in a de-differentiated state in culture when compared to the RPE in-vivo. It is known that Vascular Endothelial Growth Factor (VEGF) is secreted by RPE cell lines in-vitro. VEGF among other factors has been implicated in many eye diseases such as choroidal neovascularisation in Age Related Macular Degeneration, diabetic retinopathy and retinopathy of prematurity. We assessed the effect of different growth media on differentiation characteristics of the Human RPE cell line ARPE-19 including Apical-Basal VEGF-A secretion, ZO-1, actin distribution, Na,K-ATPase, Keratin-8 expression, and pigmentation.
Methods: :
Passages 22-24 of ARPE-19 were seeded onto uncoated tissue culture filters and grown for upto 3 months in DMEM/F12 or DMEM based growth media containing either high or low (euglycemic) glucose. Cell culture profile and Elisa’s for VEGF-A were assessed in triplicate.
Results: :
DMEM based media promoted favourable differentiation characteristics when compared to DMEM/F12. VEGF-A secretion was measured from 7-day conditioned media samples. VEGF-A secretion was higher in the DMEM based media when compared to DMEM/F12. VEGF-A secretion was greater apically than basally in high glucose conditions. Favourable morphology, pigmentation, actin distribution, and Na,K-ATPase expression was observed in DMEM based media. Improved polarity of the cells was confirmed with electron microscopy.
Conclusions: :
DMEM based media promote favourable differentiation characteristics in ARPE-19 as confirmed by confocal microscopy and electron microscopy, while increasing VEGF-A secretion compared to DMEM/F12. The constituents responsible for such differences between the two media are a matter of current investigation.
Keywords: retinal pigment epithelium • differentiation • age-related macular degeneration