Drusen in patient-derived hiPSC-RPE models of macular dystrophies
journal contribution
posted on 2023-05-19, 11:21authored byGalloway, CA, Dalvi, S, Hung, SSC, MacDonald, LA, Latchney, LR, Wong, RCB, Guymer, RH, David MackeyDavid Mackey, Williams, DS, Chung, MM, Gamm, DM, Pebay, A, Alexander HewittAlexander Hewitt, Singh, R
Age-related macular degeneration (AMD) and related macular dystrophies (MDs) are a major cause of vision loss. However, the mechanisms underlying their progression remain ill-defined. This is partly due to the lack of disease models recapitulating the human pathology. Furthermore, in vivo studies have yielded limited understanding of the role of specific cell types in the eye vs. systemic influences (e.g., serum) on the disease pathology. Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases. Consistent with clinical studies, sub-RPE basal deposits were present beneath both control (unaffected) and patient hiPSC-RPE cells. Importantly basal deposits in patient hiPSC-RPE cultures were more abundant and displayed a lipid- and protein-rich "drusen-like" composition. Furthermore, increased accumulation of COL4 was observed in ECM isolated from control vs. patient hiPSC-RPE cultures. Interestingly, RPE-specific up-regulation in the expression of several complement genes was also seen in patient hiPSC-RPE cultures of all three MDs (SFD, DHRD, and ADRD). Finally, although serum exposure was not necessary for drusen formation, COL4 accumulation in ECM, and complement pathway gene alteration, it impacted the composition of drusen-like deposits in patient hiPSC-RPE cultures. Together, the drusen model(s) of MDs described here provide fundamental insights into the unique biology of maculopathies affecting the RPE-ECM interface.
History
Publication title
Proceedings of the National Academy of Sciences
Volume
114
Issue
39
Pagination
E8214-E8223
ISSN
0027-8424
Department/School
Tasmanian School of Medicine
Publisher
Natl Acad Sciences
Place of publication
2101 Constitution Ave Nw, Washington, USA, Dc, 20418