Abstract
Purpose :
Systemic and ocular inflammation has been associated with age-related macular degeneration (AMD). Further, it has been shown that β2-microglobulin is present in drusen, one of the hallmarks of AMD. We wanted to examine the expression and secretion of β2-microglobulin by ARPE-19 cells in response to inflammatory stimulation.
Methods :
ARPE-19 cells were cultured and left to stabilize after confluency, before being changed to serum-free medium. Cells were stimulated for 48 hr at 37°C, 5% CO2 with pro-inflammatory cytokines (IFN-γ and/or TNF-α) or purified T-cells isolated from healthy donors. ARPE-19 were stimulated apically or basolaterally either with cytokines or T-cells direct or indirect. Cells and supernatant were collected. RNA was purified and subjected to human whole-transcriptome microarray (Human Gene 2.0 ST Array GeneChips, Affymetrix). β2-microglobulin secretion by ARPE-19 cells was measured using ELISA.
Results :
Gene expression of β2-microglobulin was upregulated in ARPE19-19 cells stimulated with inflammatory cytokines. This upregulation was primarily seen through IFN-γ stimulation. β2-microglobulin secretion was increased after stimulation with inflammatory cytokines or T-cells, and a synergistic effect from IFN-γ and TNF-α was observed. When cells were stimulated basolaterally a polarized secretion of β2-microglobulin, was observed, primarily towards the apical side.
Conclusions :
Inflammatory stimulation resulted in an increased secretion of β2-microglobulin by ARPE-19. The secretion was polarized primarily towards the apical side. It remains to be determined if this secretion contributes to the formation of drusen and thereby development of AMD.
This is a 2020 ARVO Annual Meeting abstract.